five-year review - hill air force base - 09/26/2003

FINAL

CERCLA Five-Year Review Report

Second Five-Year Review Report

for

Hill Air Force Base, Utah

September 2003

PREPARED FOR:

United States Department of Defense Hill Air Force Base Environmental Management Directorate

PREPARED BY:

URS Corporation 756 East Winchester Street, Suite 400

Salt Lake City, Utah 84107

Approved by: Date: W. Robert James Director of Environmental Management OO-ALC/EM

September 2003 ii CERCLA Five-Year Review Final Hill Air Force Base, Utah

TABLE OF CONTENTS Forward ......................................................................................................................................... ix EXECUTIVE SUMMARY ...................................................................................................... ES-1 I INTRODUCTION ............................................................................................................I-1

Purpose of Review ............................................................................................................I-1 Background and Setting....................................................................................................I-2

II DESCRIPTION OF PROCESS ...................................................................................... II-1 Review Approach............................................................................................................ II-1 Community Notification and Involvement ..................................................................... II-1 Database Design.............................................................................................................. II-2 Document Review........................................................................................................... II-2 Interviews and Inspections.............................................................................................. II-3 Technical Assessment..................................................................................................... II-6 Protectiveness Selection.................................................................................................. II-7 Report Preparation .......................................................................................................... II-8

III CONCLUSION & RECOMMENDATIONS................................................................ III-1

Basewide Findings ......................................................................................................... III-1 Changes in Chemical-Specific Clean-up Levels................................................ III-1 Site Management ............................................................................................... III-2 Basewide Issues ............................................................................................................. III-4 Basewide Recommendations ......................................................................................... III-5 OU Specific Issues and Recommendations ................................................................... III-5

IV PROTECTIVENESS STATEMENTS ..........................................................................IV-1 V TIMING FOR NEXT REVIEW FOR HILL AFB ......................................................... V-1 VI REFERENCES FOR SECTIONS I THROUGH V.......................................................VI-1 VII FIVE-YEAR REVIEW OF OPERABLE UNITS ....................................................... VII-1

Operable Unit 1......................................................................................................... OU 1-1 Five-Year Review of Sites in OU 1 (LF001, WP002, LF003, FT009, OT014,

FT081, WP080)........................................................................................... OU 1-21 Operable Unit 2......................................................................................................... OU 2-1 Five-Year Review of Sites in OU 2 (WP007, SS021) ................................ OU 2-21

September 2003 iii CERCLA Five-Year Review Final Hill Air Force Base, Utah

Operable Unit 3......................................................................................................... OU 3-1 Five-Year Review of Sites in OU 3 (ST004, WP005, WP006, ST018, SD046) ........................................................................................................ OU 3-17 Operable Unit 4......................................................................................................... OU 4-1 Five-Year Review of Sites in OU 4 (LF011, LF012, OT020, OT041, OT042)........................................................................................................ OU 4-19 Operable Unit 5......................................................................................................... OU 5-1 Five-Year Review of Sites in OU 5 (SD016, SS017, SS091) .................... OU 5-15 Operable Unit 6......................................................................................................... OU 6-1 Five-Year Review of Sites in OU 6 (ST022, OT026, SD40B)................... OU 6-19 Operable Unit 7......................................................................................................... OU 7-1 Five-Year Review of Sites in OU 7 (SS027, ST031, SS032, SS028, OT029)........................................................................................................ OU 7-17 Operable Unit 8......................................................................................................... OU 8-1 Operable Unit 9......................................................................................................... OU 9-1 Five-Year Review of Sites in OU 9 (SD023, SD034, SS092, OT106, SD040, SS089, SS090, SS108)................................................................... OU 9-25 Operable Unit 10..................................................................................................... OU 10-1 Operable Unit 11..................................................................................................... OU 11-1 Operable Unit 12..................................................................................................... OU 12-1

Appendix A Comments on Preliminary and Draft Versions of Five-Year Review Report Appendix B Community Input for the Hill AFB 2003 Five-Year Review Appendix C Documents Reviewed and Personal Communications for the Hill AFB 2003 Five-

Year Review Appendix D Inspection Checklist and Sample Site Interview Questionnaire Appendix E Changes in Chemical-Specific Clean-up Levels

September 2003 iv CERCLA Five-Year Review Final Hill Air Force Base, Utah

List of Tables Table ES-1 Summary of Protectiveness Determinations for Hill AFB ................................................. ES-1 Table 1 Operable Units at Hill AFB ....................................................................................................I-4 Table 2 Chronology of CERCLA-related events for Hill AFB ...........................................................I-5 Table 3 Typical documents reviewed and contents ........................................................................... II-2 Table 4 Additional documents reviewed as needed and contents...................................................... II-3 Table 5 Interviews conducted for the FYR........................................................................................ II-5 Table 6 Inspections conducted for the FYR....................................................................................... II-6 Table 7 Comparison of Cleanup Levels and Standards .................................................................... III-2 Table 8 Major basewide issues identified during 2003 CERCLA Five-Year Review...................... III-5 Table 9 Major issues and recommendations identified during 2003 CERCLA Five-Year Review . III-6 Table 10 Summary of Protectiveness Determinations for Hill AFB .................................................. IV-1 Table 11 Site Five-Year Review Status for Hill AFB......................................................................... IV-2 Table OU 1-1 OU 1 Site Identification ........................................................................................ OU 1-1 Table OU 1-2 OU 1 Site Chronology......................................................................................... OU 1-13 Table OU 1-3 Technical Assessment Summary for OU 1 ........................................................... OU 1-3 Table OU 2-1 OU 2 Site Identification ........................................................................................ OU 2-1 Table OU 2-2 OU 2 Site Chronology......................................................................................... OU 2-13 Table OU 2-3 Technical Assessment Summary for OU 2 ........................................................... OU 2-4 Table OU 3-1 OU 3 Site Identification ........................................................................................ OU 3-1 Table OU 3-2 OU 3 Site Chronology......................................................................................... OU 3-11 Table OU 3-3 Technical Assessment Summary for OU 3 ........................................................... OU 3-3 Table OU 4-1 OU 4 Site Identification ........................................................................................ OU 4-1 Table OU 4-2 OU 4 Site Chronology......................................................................................... OU 4-11 Table OU 4-3 Technical Assessment Summary for OU 4 ........................................................... OU 4-4 Table OU 5-1 OU 5 Site Identification ........................................................................................ OU 5-1 Table OU 5-2 OU 5 Site Chronology........................................................................................... OU 5-9 Table OU 5-3 Technical Assessment Summary for OU 5 ........................................................... OU 5-3 Table OU 6-1 OU 6 Site Identification ........................................................................................ OU 6-1 Table OU 6-2 OU 6 Site Chronology........................................................................................... OU 6-9 Table OU 6-3 Technical Assessment Summary for OU 6 ........................................................... OU 6-3 Table OU 7-1 OU 7 Site Identification ........................................................................................ OU 7-1 Table OU 7-2 OU 7 Site Chronology........................................................................................... OU 7-9 Table OU 7-3 Technical Assessment Summary for OU 7 ........................................................... OU 7-2 Table OU 8-1 OU 8 Site Identification ........................................................................................ OU 8-1 Table OU 8-2 OU 8 Site Chronology......................................................................................... OU 8-11 Table OU 9-1 OU 9 Site Identification ........................................................................................ OU 9-1 Table OU 9-2 OU 9 Site Chronology......................................................................................... OU 9-13 Table OU 9-3 Technical Assessment Summary for OU 9 ........................................................... OU 9-2 Table OU 9-4 OU 9 Site OT106 Deferred Sites .......................................................................... OU 9-4 Table OU 10-1 OU 10 Site Identification .................................................................................... OU 10-1 Table OU 10-2 OU 10 Site Chronology....................................................................................... OU 10-7 Table OU 11-1 OU 11 Site Identification .................................................................................... OU 11-1 Table OU 11-2 OU 11 Site Chronology....................................................................................... OU 11-7 Table OU 12-1 OU 12 Site Identification .................................................................................... OU 12-1 Table OU 12-2 OU 12 Site Chronology....................................................................................... OU 12-7

September 2003 v CERCLA Five-Year Review Final Hill Air Force Base, Utah

List of Figures Figure 1 Site Overview Map .................................................................................................................I-3 Figure OU 1-1 Site Features for Operable Unit 1, Showing TCE Plume ..................................... OU 1-9 Figure OU 1-2 Site Features for Operable Unit 1, Showing DCE Plume .................................. OU 1-11 Figure OU 2-1 Site Features for Operable Unit 2........................................................................ OU 2-11 Figure OU 3-1 Site Features for Operable Unit 3.......................................................................... OU 3-9 Figure OU 4-1 Site Features for Operable Unit 4.......................................................................... OU 4-9 Figure OU 5-1 Site Features for Operable Unit 5.......................................................................... OU 5-7 Figure OU 6-1 Site Features for Operable Unit 6.......................................................................... OU 6-7 Figure OU 7-1 Site Features for Operable Unit 7.......................................................................... OU 7-7 Figure OU 8-1 Site Features for Operable Unit 8, Showing TCE Plume...................................... OU 8-7 Figure OU 8-2 Site Features for Operable Unit 8, Showing DCA Plume..................................... OU 8-9 Figure OU 9-1 Site Features for Operable Unit 9........................................................................ OU 9-11 Figure OU 10-1 Site Features for Operable Unit 10...................................................................... OU 10-5 Figure OU 11-1 Site Features for Operable Unit 11...................................................................... OU 11-5 Figure OU 12-1 Site Features for Operable Unit 12...................................................................... OU 12-5

September 2003 vi CERCLA Five-Year Review Final Hill Air Force Base, Utah

List of Acronyms 1E-6 1x10-6 or 0.000001 ADR Analytical Data Report AFB Air Force Base amsl above mean sea level ARAR Applicable, Relevant, and Appropriate Requirement AS Air Sparging ASTP Air Stripper Treatment Plant bgs below ground surface BNAE Base-Neutral-Acid Extractable BSHW Bureau of Solid and Hazardous Waste BRA Baseline Risk Assessment BTEX Benzene, Toluene, Ethylbenzene, Xylenes CAMU Corrective Action Management Unit CDP Chemical Disposal Pit CERCLA Comprehensive Environmental Response, Compensation, and Liabilities Act COC Contaminant of Concern COPC Contaminant of Potential Concern CPT Cone Penetration Testing CSF Cancer Slope Factor CWSID Central Weber Sewer Improvement District CY Calendar Year DCA Dichloroethane DCE Dichloroethene DCE11 1,1-Dichloroethene DCE12C 1,2-cis-Dichloroethene DCE12T 1,2-trans-Dichloroethene DERP Defense Environment Restoration Program DNAPL Dense Non-Aqueous Phase Liquid DRMO Defense Reutilization and Marketing Office EE/CA Engineering Evaluation / Cost Analysis EMR Environmental Management and Restoration EPA Environmental Protection Agency ERPIMS Environmental Restoration Program Information Management System FFA Federal Facilities Agreement FS Feasibility Study FT Fire Training FTA Fire Training Area FYR Five-Year Review GAC Granular Activated Carbon GIS Geographic Information Services GES Groundwater Extraction System gpm gallons per minute GW Groundwater HDUS Horizontal Drain Upgrade System IRA Interim Remedial Action IRP Installation Restoration Program ITP Innovative Technology Program IWTP Industrial Wastewater Treatment Plant L Liter LF Landfill LNAPL Light Non-Aqueous Phase Petroleum Liquid LTM Long-Term Monitoring LTO Long-Term Operation LUST Leaking Underground Storage Tank

September 2003 vii CERCLA Five-Year Review Final Hill Air Force Base, Utah

MAMS Missile Assembly, Maintenance, and Storage MAP Management Action Plan MCL Maximum Contaminant Level MDL Minimum Detection Limit MEK Methyl Ethyl Ketone MNA Monitored Natural Attenuation MTBE Methyl Tert-Butyl Ether MW Montgomery Watson MW Monitoring Well MWH Montgomery Watson Harza NA Not Applicable NCP National Contingency Plan NDCSD North Davis County Sewer District NFRAP No Further Response Action Planned NIT North Interceptor Trench NPDES National Pollutant Discharge Elimination System NPL National Priority List O&M Operations and Maintenance OO-ALC Ogden Air Logistics Center OU Operable Unit OWS Oil/Water Separator PA Preliminary Assessment PAH Polyaromatic Hydrocarbon PCB Polychlorinated Biphenyl PCE Perchloroethene PESD Proposed Explanation of Significant Differences PITT Partitioning Interwell Tracer Test PM Project Manager POTW Publicly Owned Treatment Works ppb parts per billion ppbv parts per billion by volume PSVP Performance Standard Verification Plan PSVR Performance Standard Verification Report PTS Pump-and-Treat System RA Remedial Action RAO Remedial Action Objective RBC Risk-Based Concentration RBSL Risk-Based Screening Level RDS Remote Data System RAB Restoration Advisory Board RfD(i) Reference Dose for Inhalation RfD(o) Reference Dose for Oral ingestion RI Remedial Investigation ROD Record of Decision RVMF Refueling Vehicle Maintenance Facility RCRA Resource Conservation and Recovery Act SI Site Inspection SEAR Surfactant-Enhanced Aquifer Remediation SOP Standard Operating Procedure SRS Source Recovery System SVE Soil Vapor Extraction SVOC Semi-Volatile Organic Compound SW Surface Water TARS Tooele Army Rail Shop TCA Trichloroethane TCE Trichloroethene

September 2003 viii CERCLA Five-Year Review Final Hill Air Force Base, Utah

TDS Total Dissolved Solids TPH-DRO Total Petroleum Hydrocarbons – Diesel Range Organics TS Treatability Study TSCA Toxic Substances Control Act UCS Upgradient Control System UDEQ Utah Department of Environmental Quality UDERR Utah Division of Environmental Response and Remediation µg Microgram (10-6 gram) USGS United States Geological Service UST Underground Storage Tank VOC Volatile Organic Compounds WOST Waste Oil Storage Tanks WPOP Waste Phenol Oil Pit WWTP Wastewater Treatment Plant

September 2003 ix CERCLA Five-Year Review Final Hill Air Force Base, Utah

Forward to the FINAL Five-Year Review Report This FINAL Five-Year Review Report was prepared following the process described in Section II. URS conducted an independent technical review of the remedial actions at Hill AFB for the purpose of determining the degree of protectiveness provided by the existing remedies. URS prepared this report based primarily on research and review of documents provided by Hill AFB and incorporation of comments provided through an independent review by Hill EMR staff regarding historical findings and issues that are not fully described in published documents.

The Report contains protectiveness statements, issues, and recommendations. Hill AFB reviewed the May DRAFT Five-Year Review Report and prepared an independent response regarding the recommendations and protectiveness statements prepared by URS for each operable unit. That response was considered during preparation of the June DRAFT. All comments from Hill AFB EMR on preliminary versions of sections of the FYR, as well as the URS actions based on EMR response to the May DRAFT, are provided in Appendix A. In addition, the May DRAFT was provided by Hill EMR to the Restoration Advisory Board (RAB).

The Utah Department of Environmental Quality (UDEQ) and the US Environmental Protection

Agency (USEPA) also provided comments on the May DRAFT during preparation of the August DRAFT. The RAB, UDEQ, and USEPA comments, EMR direction, and URS response are included in a comment resolution matrices in Appendix A. The June DRAFT was available for a 30-day public comment period. No public comments were received on the FYR Report by Hill EMR. The June and August DRAFTs were improved in presentation and content because of the contributions from EMR, the RAB, UDEQ, and USEPA. One comment was provided by UDEQ on the August DRAFT regarding an omission in Table A.3. The omission was corrected for this FINAL version of the report. This Five-Year Review Report reflects the results of an independent review.

Five-Year Review Summary Form

SITE IDENTIFICATION

Site name (from WasteLAN): Hill Air Force Base

EPA ID (from WasteLAN): UT0571724350

EPA Region: VIII State: UT City/County: Hill AFB / Davis

SITE STATUS

NPL status: Final Deleted Other (specify)

Remediation status (choose all that apply): Under Construction Operating Complete

Multiple OUs?* YES NO

Construction completion date: N/A

Has site been put into reuse? YES NO

REVIEW STATUS

Lead agency: Dept. of Defense (Air Force)

Author name: Jeff Watkins Author title: EM Operations Program Manager Author affiliation: HAFB / EMR

Review period:** through 09/30/2002 Date(s) of site inspection: January and February, 2003

Type of review: Post-SARA Pre-SARA NPL-Removal Only Non-NPL Remedial Action Site NPL State/Tribe-lead Regional Discretion Review number: 1 (first) 2 (second) 3 (third) Other (specify)

Triggering action: Actual RA Onsite Construction at OU# Actual RA Start at OU# Construction Completion Previous Five-Year Review Report Other (specify)

Triggering action date (from WasteLAN): 09/30/1998

Due date (five years after triggering action date): 09/30/2003

Next 5 year review date: 09/30/2008 * [“OU” refers to operable unit.] ** [Review period should correspond to the actual start and end dates of the Five-Year Review in WasteLAN.]

September 2003 ES-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

EXECUTIVE SUMMARY

In July 1987, the U.S. Environmental Protection Agency placed Hill AFB on the National Priorities List under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). The U.S. Department of Defense is preparing this Five-Year Review Report pursuant to CERCLA and in accordance with the National Contingency Plan, which require a review of remedial actions no less often than every five years at all sites that do not allow unlimited use and unrestricted exposure.

The primary purpose of this Five-Year Review is to determine whether the remedies selected at Hill Air Force Base are protective of human health and the environment. The review was intended to: 1) evaluate whether the remedy is operating as designed; 2) evaluate whether the original action levels are achieving protection; 3) determine if additional protection at each site is still needed; and 4) evaluate if protectiveness has been achieved and if the site can be excluded from the next Five-Year Review.

A total of 42 Installation Restoration Program (IRP) sites in twelve Operable Units (OUs) at Hill

AFB were evaluated as a part of this review. The evaluation of these sites consisted of a document review, interview, and inspection process focused on addressing three questions in the Five-Year Review Technical Assessment. The three questions are:

A. Is the remedy functioning as intended by the decision document? B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives

(RAOs) used at the time of the remedy still valid? C. Has any other information been uncovered that could call into question the protectiveness of the

remedy? The protectiveness categories include: protective, protectiveness cannot be determined, protective

in the short term, will be protective once remedy complete, not protective, and not applicable. A not applicable determination was given to sites that already had No Further Remedial Action Planned (NFRAP) status and had no remedial actions as well as sites where remedial investigations and feasibility studies were still being completed and a remedy has not been installed. The summary of the protectiveness determinations is included in Table ES-1. Because some OUs at Hill AFB do not have remedies selected and constructed, a basewide protectiveness statement is not included in this review. Basewide, OU-specific, and site-specific issues and recommendations are included in this report. One OU, OU 12, is not protective. However, with current groundwater use restrictions and air treatment units in some homes, there is not apparent danger of exposure.

Table ES-1. Summary of Protectiveness Determinations for Hill AFB

Protectiveness Determination Number of IRP Sites

Number of OUs Operable Units

Protective 8 2 3 and 7 Protectiveness cannot be determined 6 4 1, 2, 6, and 8 Protective in the short term 2 2 4 and 5 Will be protective once remedy complete 1 1 9 Not protective 1 1 12 Not applicable 24 2 10 and 11

A draft of this Five-Year Review Report was available for a 30-day public comment period. No

public comments were received.

September 2003 I-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

I INTRODUCTION

Purpose of Review The primary purpose of a Five-Year Review (FYR) is to determine whether the remedies selected

at Hill Air Force Base (AFB) are protective of human health and the environment. The methods, findings, and conclusions of reviews are documented in five-year review reports. In addition, five-year review reports identify deficiencies in remedies and plans to meet remedial action objectives (RAOs) found during the review, if any, and describe recommendations or corrective action that may be taken to address them.

The U.S. Department of Defense is preparing this Five-Year Review pursuant to the

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) §121 and in accordance with the National Contingency Plan (NCP). CERCLA §121 states:

If the President selects a remedial action that results in any hazardous substances, pollutants, or contaminants remaining at the site, the President shall review such remedial action no less often than each five years after the initiation of such remedial action to assure that human health and the environment are being protected by the remedial action being implemented. In addition, if upon such review it is the judgment of the President that action is appropriate at such site in accordance with section [104] or [106], the President shall take or require such action. The President shall report to the Congress a list of facilities for which such review is required, the results of all such reviews, and any actions taken as a result of such reviews.

This requirement is further interpreted in the NCP; 40 CFR §300.430(f)(4)(ii) states: If a remedial action is selected that results in hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead agency shall review such action no less often than every five years after initiation of the selected remedial action.

CERCLA and the NCP require a review of remedial actions (RAs) no less often than every five

years at all sites that do not allow unlimited use and unrestricted exposure. The review is intended to: 1) evaluate whether the remedy is operating as designed; 2) evaluate whether the original action levels are achieving protection; 3) determine if additional protection at each site is still needed; and 4) evaluate if protectiveness has been achieved and if the site can be excluded from the next Five-Year Review. Evaluation of the remedy and the determination of protectiveness is based on and supported by data and observations.

Hill Air Force Base Environmental Management Directorate contracted URS Corporation to

conduct a Five-Year Review of Hill AFB (NPL site ID: UT0571724350). This review was conducted from November 2002 through April 2003 and this report documents the results of the review. This is the second Five-Year Review for Hill Air Force Base. The triggering action for this statutory review is the signature date of the previous Five-Year Review Report dated September 1998. The Five-Year Review is required because hazardous substances, pollutants, or contaminants remain on the Base above levels that allow for unlimited use and unrestricted exposure.

This 2003 Five-Year Review goes beyond the statutory requirements in that it addresses all

Installation Restoration Program (IRP) sites on the Base that had or may have CERCLA-associated


actions at any time, not just those sites where hazardous substances, pollutants, or contaminants remain. Protectiveness assessments are presented for each IRP site and for each Operable Unit (OU).

Background and Setting Hill AFB is located in northern Utah, about 30 miles north of Salt Lake City and about five miles

south of Ogden, Utah, just west of the Wasatch Front mountain range. The land use in the area around the Base includes urban, suburban, agricultural (both irrigated and dryland farming), and vacant ground. The land west of Hill AFB is entirely urban, whereas the north and southeast sides are mostly rural. Hill AFB is surrounded by the incorporated towns of South Weber, Washington Terrace, Riverdale, Roy, Sunset, Clearfield, and Layton (see Figure 1).

The Base is included in the Weber Delta Sub-district of the East Shore hydrologic region. The

Sunset, 250 to 400 feet below the ground surface, and Delta, 500 to 700 feet below ground surface (bgs), are the principal aquifers of the East Shore area. Shallow groundwater (GW) also occurs in flood plain deposits and regionally in the valley lowlands within a few feet of the ground surface. Many seeps and springs exist at various locations within the communities surrounding the Base.

Hill AFB is part of the Air Force Materiel Command located in northern Utah. The Ogden Air

Logistics Center (OO-ALC) is based out of Hill and is responsible for many operational and support missions such as engineering and logistics management for various aircraft as well as for intercontinental ballistic missiles. Since the origination of “Hill Field” in 1940, Hill AFB has been the site of maintenance and repair activities for a number of key aircraft during World War II, Korea, Vietnam, and Desert Storm.

The maintenance and repair activities at Hill AFB generate waste including chlorinated and non-

chlorinated solvents and degreasers, fuels and other hydrocarbons, acids, bases, and metals. These chemicals and their associated waste products were historically disposed of at the Industrial Wastewater Treatment Plant (IWTP), in chemical disposal pits (CDPs) and landfills (LFs) on the Base, or at other Air Force facilities. Disposal in the chemical pits and landfills was discontinued in 1980. All wastes are currently treated at the IWTP, recycled on Base, or sent to off-Base treatment or disposal facilities.

In July 1987, the U.S. Environmental Protection Agency (EPA) placed Hill AFB on the National

Priorities List (NPL) under CERCLA. In April 1991, Hill AFB entered a Federal Facility Agreement (FFA) with the Utah Department of Environmental Quality (UDEQ) and the EPA Region VIII in Denver to establish a procedural framework and schedule for implementing the appropriate response actions in accordance with existing regulations. At that time, the FFA defined seven geographic areas known as Operable Units. There are twelve Operable Units today. Many of them extend off base into the surrounding communities. Each OU encompasses one or more hazardous waste sites and facilitates administration of the CERCLA process. Table 1 briefly describes each of the OUs at Hill AFB.


Table 1. Operable Units at Hill AFB

OU Description Number of IRP Sites Reviewed

1 Areas between former Landfill No. 3 and Landfill No. 4 (inclusive) and associated groundwater plume

7

2 Chemical Pit 3 and associated groundwater plume 2 3 Area between Berman Pond and Building 514 (inclusive) 5 4 Areas southeast of North Gate, including Landfill No.1 and associated

groundwater plume 5

5 1600 Area and two associated groundwater plumes extending west off-Base 3 6 1900 and 2000 Areas west of North Gate and associated groundwater

plume 3

7 200 Area (soil only) 5 8 Layton TCE plume 1 9 Buildings in all areas of Base that have not been assigned to an OU; many

are deferred sites or under RI 8

10 1200 Area and associated groundwater plume 1 11 Former Building 454 (Service Station) 1 12 Groundwater plume west of MAMS-2 Area, extending off-Base into Roy 1

Total Number of IRP Sites 42

Table 2 lists major events at Hill AFB since it opened in 1920. In addition to important basewide events, the record of decision (ROD) documents for OUs 1 through 7 also are included. OUs 8 through 12 are still under investigation, with some interim actions, and do not have RODs. Hill AFB has more than 80 years of operational history and approximately 20 years over which remedial actions have been implemented.

Table 2. Chronology of CERCLA-related events for Hill AFB

Month Year Event Comments Reference

1981 Phase I (records search) of the Air Force Installation Restoration Program starts at Hill AFB.

Part of nationwide IRP initiated by the Department of Defense in 1978.

Federal Facilities Agreement Under CERCLA Section 120

01 1982 Results of Phase I of IRP published.

Identified thirteen areas at Hill AFB where hazardous materials may have been used, stored, treated, or disposed. These areas are later grouped into Operable Units 1 – 7.


09 1982 Phase II (preliminary assessments/site inspections) of IRP begins.

Designed to identify and quantify contaminants and to evaluate extent, direction, and rate of contaminant migration.


07 1984 Cease and Desist Order issued by UDWQ.

Order issued for leachate discharge below Landfill 4 (now part of OU 1).

Record of Decision Operable Unit 1 IRP Sites LF01, WP02, LF03, FT09, FT81, and WP80

08 1984 Construction begins on groundwater treatment facility at OU 1.

This facility is the first remedial action conducted at Hill AFB.

Comprehensive Remedial Investigative Report for Operable Unit 1 (IRP Site LF01, LF03, WP02, FT09, OT14, FT81, and WP80) Volume 1

09 1984 Results of Phase II of IRP published. Identified VOC and heavy metal contaminants at Hill AFB.


10 1984 EPA proposes Hill AFB for the National Priority List. Federal Facilities Agreement Under CERCLA

Section 120

1985 Additional remedies installed at OU 1. Remedies include low-permeability caps over source areas and subsurface barrier.


07 1987 Hill AFB placed on NPL by EPA. Federal Register Vol. 52, No. 140

04 1991 Hill enters into FFA with UDEQ and EPA.

Established a procedural framework and schedule for developing, implementing, and monitoring response actions at Hill AFB in accordance with existing regulations. Seven operable units were defined under the FFA.


08 1991 Record of Decision for Interim Action at OU 2.

Pump-and-treat system for removal and destruction of free-phase DNAPLs from groundwater is selected as the remedy for interim action.

Record of Decision for Interim Action at Operable Unit 2, Final

09 1992 Record of Decision for Interim Action at Operable Unit 3 Site ST04.

Selected an asphalt cap as the interim remedial action at Site ST004.

Record of Decision for Interim Action at Operable Unit 3 Site ST04

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Table 2. Chronology of CERCLA-related events for Hill AFB (Cont.)

Month Year Event Comments Reference 1993 OU 8 created. Contaminated groundwater, previously considered

part of OU 3 and OU 7, redesignated as OU 8. Remedial Investigation Report for Operable Unit 8

06 1994 Record of Decision for OU 4.

The selected remedy addresses contaminated groundwater, surface water, and landfill contents at OU 4, and air inside off-Base residences in plume area.

Record of Decision and Responsiveness Summary for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42)

01 1995 Formation of Restoration Advisory Board

Created to advise Hill AFB on community and interest group concerns regarding environmental investigation and cleanup.

Minutes, First RAB Meeting, January 12, 1995

09 1995 Record of Decision for OU 3. The selected remedy called for SVE at Site ST018, a cap at Site WP005, and cap maintenance at ST004.

Record of Decision for OU 3

09 1995 Record of Decision for OU 7.

Mandated groundwater monitoring upgradient, beneath, and downgradient of the area where contaminant concentrations in soils are above health-based risk levels.

Record of Decision for Operable Unit 7

09 1996 Record of Decision for OU 2. The selected remedy addresses contaminated groundwater, soil, and surface water at OU 2.

Record of Decision and Responsiveness Summary for Operable Unit 2

05 1997 Interim Record of Decision for OU 8. An Interim Remedial Action (hydraulic containment system at base boundary) was required.

Record of Decision for an Interim Remedial Action at Operable Unit 8

10 1997 Record of Decision for OU 6. Contaminated groundwater required active treatment by extraction and air stripping.

Record of Decision Operable Unit 6 Sites ST022, OT026, SD40B

09 1998 First Five-Year Review of CERCLA Sites at Hill AFB

Focused on Operable Units, not on individual IRP sites. Hill AFB Five-Year Review, September 1998

10 1998 Record of Decision for OU 1. ROD established RAOs and remedial action goals for existing and planned actions at OU 1.


09 2000 OU 10 created Redesignation of groundwater contamination plumes identified during OU 9 investigations. SS109, the 1200 Area, redesignated as OU 10.

OU10 Remedial Investigation/Feasibility Study Operable Unit 10 Analytical Data Report, May 1 2001 - January 31 2002

09 2000 OU 11 created Zone 7 - Golf Course Area (Site SS090) and Former Building 454 (Site OT097), formerly part of OU 9, were redefined as OU 11.

Final Analytical Data Report (ADR) For Operable Unit 9 Investigation Areas 1 May Through 10 October 2000

10 2001 OU 12 created The northern GW contamination plume within OU 5 is designated OU 12.

Final Operable Units 5 and 12 Historic Site and Source Area Review, March 2002

03 2002 Site Management Plan for OU 9 Deferred Sites

Provides mechanism to track and inventory deferred sites.

Operable Unit 9 Calendar Year 2001 Deferred Sites Inventory Report, Hill Air Force Base, Utah. Draft

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September 2003 II-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

II DESCRIPTION OF PROCESS

Review Approach The Five-Year Review was conducted, in general, per the EPA guidance (EPA 2001). For each

site, there was a thorough document review, inspections, and interviews as necessary to determine the protectiveness of remedies. For sites with no remedial actions to-date (e.g., undergoing Remedial Investigation [RI]) this review served as a baseline to establish that the planned approach will be able to achieve protection. For sites that have a “No Further Response Action Planned” (NFRAP) classification, this review served as a check to insure there were no issues with the site and is, in most cases, the final review required.

The document review, interviews, and inspections were focused to gather the information

necessary to address the three questions in the Five-Year Review Technical Assessment (EPA 2001) and not to generate new data or significantly re-evaluate existing data sets to assess previous conclusions. Any issues that were identified in the review which suggested that additional information may be necessary to evaluate previous work are highlighted in the “Issues” portions of this report. Specifically, the evaluation team systematically reviewed documents and captured the findings for each site in a Site Summary. Each Site Summary and all of the back-up material used to generate conclusions about each site and each OU are stored in a Microsoft (MS) Access® database.

The review “unit” for this Five-Year Review was the IRP site and the review was conducted, where possible, on a site-by-site basis. However, historical management at Hill AFB has been structured around Operable Units and much of the information is reported by OU. Therefore, for many of the Hill AFB IRP sites, this review was necessarily conducted by evaluating OU-wide documentation.

Members of the Restoration Advisory Board (RAB), a group of local people representing the

surrounding communities and interest groups, were notified of the initiation of the Five-Year Review on September 26, 2002. The review team was led by Jeff Watkins of Hill AFB, EM Operations Program Manager (PM), and included the Community Involvement Coordinator for Hill AFB, Charles Freeman, and the Evaluation Team staff from URS Corporation, lead by Barbara L. Hall. URS conducted the review in close coordination with Project Managers from Hill AFB, who provided clarification throughout the process on items not specifically addressed in documentation. Hill AFB EMR comments on the preliminary and DRAFT versions of the report are included as Appendix A.

Community Notification and Involvement Community involvement is an important part of the success of Hill AFB environmental cleanup

efforts. Professional staff, both within Hill AFB and under contract, assists in the daily management of community involvement issues. The 2003 Five-Year Review is special in the sense that it is a critical self-examination of the success of the cleanup program, and public participation in the examination is particularly important. To emphasize this importance, the community involvement contractor was tasked to manage Five-Year Review community involvement independent of the contractor hired to evaluate technical cleanup efforts.

Early in the project, Hill AFB published a notice in the Ogden Standard Examiner (local daily

newspaper) and the Hilltop Times (Hill AFB weekly newspaper). This notice described the objectives of the Five-Year Review and established the public role in the process. Hill AFB has conducted interviews with both public and private members of the community (between March 10 and April 22, 2003),


specifically tailored to obtain public input about cleanup activities. Relevant comments are addressed in Appendix B.

The Restoration Advisory Board has been closely involved in the Five-Year Review process. A

FYR Working Group within the RAB was formed to consult with Hill AFB regarding the Five-Year Review process and report format. A DRAFT of the Report was provided to the RAB and their comments are included in Appendix A. The Working Group reports to the RAB in a special effort to ensure effective public participation.

A news media release announced the availability of the DRAFT Five-Year Review report and a

request for public comment. No public comments were received. The final Five-Year Review Report will be placed in the Administration Record and will be available to the public. Community involvement will continue beyond the Five-Year Review as a necessary and vital part of the cleanup program.

Database Design The data collection process included specific techniques to enter data derived from document

reviews, inspections, and interviews into a searchable, relational database using MS Access®. Tables were built and relationships established so that all information can be downloaded and distinguished by OU number and/or site identification, as well as other key fields. This allows all review information for each OU to be queried and summarized where necessary. Moreover, detailed tables were generated from the database tables for scrutinizing review material and final reporting.

Document Review The document review was conducted by first examining documentation directly resulting from

the CERCLA cleanup process for a site or OU. These baseline documents typically include those listed in Table 3, which also indicates the types of information that are available in each document. Table 3. Typical documents reviewed and contents Document Title Contents Pertinent to the FYR

Record of Decision

Background, nature and extent of contamination, cleanup alternatives, cleanup objectives, contaminants, remedial decision, ARARs

Remedial Action Report Construction activities

Action Memorandum Background, nature and extent of contamination, cleanup alternatives, cleanup objectives, contaminants, remedial decision

Annual Report / O&M Reports / O&M Manual System objectives, system performance, design parameters, trends

Long-term monitoring data Monitoring data, trends, interpretation of monitoring data

Performance Standard Verification Plan (PSVP) Sampling plan, performance metrics, closure pathways

Memo on Explanation of Significant Differences Changes from original remedy Management Action Plan 2001 (MAP) Remedial status, background Drinking Water Standards Current state and federal standards EPA Region III Risk-Based Concentration (RBC) Tables Current risk factors


For many sites, review of this first set of documentation was not adequate to conduct the Technical Assessment and evaluate protectiveness. When this was the case, additional documentation was reviewed. Table 4 lists those types of additional documentation and the information that was gathered from them. Table 4. Additional documents reviewed as needed and contents Document Title Contents Pertinent to the FYR Risk Assessment Exposure assumptions, risk calculations Remedial Investigation Background, nature, and extent of contamination Feasibility Study (FS) Cleanup alternatives, cleanup objectives Proposed Plan Remedy Engineering Evaluation/Cost Analysis (EE/CA) Background, nature and extend of contamination,

cleanup alternatives, cleanup objectives, contaminants, remedial decision

Construction report Construction activities Remedial Design Remedy, design parameters, cleanup objectives

A list of all documents that were reviewed for this Five-Year Review is included in Appendix C. A Preliminary Site Summary was developed first for each site to highlight data gaps that needed

to be addressed either with a more in-depth document review or through site inspections and personnel interviews. Once inspections and interviews were complete, the Site Summary was updated. Following the completion of the review for all sites in an OU, the results were synthesized into a summary for the Operable Unit. Finally, lists of issues and recommendations from all OUs were considered to develop the conclusions presented in Section III.

Interviews and Inspections As follow-on to the document review, a series of interviews and inspections were conducted in

January, February, and March of 2003 to understand aspects of site status that were not clear from the document review. Also, questions and/or issues stemming from data evaluations completed at some sites were resolved during this interview process. Depending on the type of information required, the interviews included site operations and maintenance (O&M) managers and staff and Environmental Management and Restoration (EMR) project managers. The EMR project managers interviewed included:

• Current managers of the site, • Construction oversight managers of the site remedy installation, • Manager of post-ROD OUs, and • Managers with historical knowledge.

The EMR project manager interviewed for each OU was based on the type of information

required to complete a thorough review. A Site Interview Questionnaire was developed after the documentation review was completed and prior to each interview. The questionnaire was based on recommendations for interviews in the EPA guidance (EPA 2001, Appendix C) but was expanded for each interview to address specific data gaps and unresolved issues that had been identified for the site. Appendix D includes an example of a questionnaire used for the interview of EMR project managers for OU 7.

All interviews were conducted by reviewers who were not involved with any aspect of remedial activities at the OU. If the person completing the site review was not conducting the interviews, a


meeting was held between the interviewer and the site reviewer to examine the site issues prior to the interview. Interviewers conducted one-on-one interviews either in person or on the phone. The completed Site Interview Questionnaires are part of the FYR Database. Thirty-seven interviews were conducted as a part of the Five-Year Review. The persons interviewed, their role, and the date and time of the interviews are listed in Table 5.

The interviews with EMR project managers for OU 3, OU 4, and OU 7 were conducted

differently. Initially, both Jeff Watkins, the post-ROD project manager, and Oscar Torres, the current project manager, were interviewed simultaneously regarding the current activities and status at these OUs. Later, Steve Hicken, the historical project manager, was also interviewed to resolve questions regarding the history of the sites.

Twenty-four inspections were conducted as a part of the Five-Year Review during the months of

January and February of 2003. Inspectors were selected for each OU based on their knowledge of the OU and impartiality with respect to current operation. Prior to the inspection, the inspector prepared a checklist based on recommendations in the EPA guidance (EPA 2001, Appendix D). An example of a checklist used during the inspection of all sites is included in Appendix D. This checklist is comprehensive and lengthy. Only the applicable portions of each checklist were filled out during the inspection. The completed Site Inspection Checklists are included in the FYR Database.

Only one site with NFRAP status, SS092, was inspected, on 3 February 2003. Following this

inspection, because no additional information was obtained during this inspection and no visible risks exist at the NFRAP sites, no more sites with NFRAP status were inspected for this review. All sites with a remedy in place or those sites in the pre-ROD phase were inspected and are listed in Table 6. Multiple inspections were completed at sites with several remedies (e.g., OU 6), as shown in the table.

The extensive site inspection that was conducted as part of this review indicates that the IRP sites,

associated infrastructure, and treatment systems and facilities are generally clean and in good repair. Inspections identified no significant health and safety issues for employees and equipment is well maintained. The presence of on-site documentation and proper institutional controls were verified during the inspection process and any specific issues are captured in the appropriate Site summaries.

The Hill AFB Community Involvement Coordinator interviewed community action groups and

site neighbors and results of those interviews are presented in Appendix B.


Table 5. Interviews conducted for the FYR

Operable Unit Persons to Interview Role Date and Time of

Interview Ray Spencer (EMR) Current & Construction PM 2/6/03 9:00 AM Curt Himle (URS) O&M Contractor (Tech) 2/17/03 1:15 PM

Bruce McCormack (URS) O&M Contractor (Tech) 2/6/03 10:00 AM OU 1

Stacey Arens (URS) O&M Contractor (Eng.) 2/6/03 10:30 AM Stacey Arens (URS) O&M Contractor (Eng.) 2/6/03 3:00 PM Curt Himle (URS) O&M Contractor (Tech) 2/5/03 1:00 PM OU 2

Ray Spencer (EMR) O&M and Construction PM 2/6/03 1:00 PM Steve Knutson (URS) O&M Contractor (Tech) 2/21/03 9:30 AM

Holly Renn (URS) O&M Contractor (PM) 2/24/03 2:00 PM Jeffrey Watkins (EMR) Post-ROD PM 3/4/03 9:30 AM

OU 3*

Oscar Torres (EMR) Current PM 3/4/03 9:30 AM Steve Knutson (URS) O&M Contractor (Tech) 2/21/03 9:50 AM

Sage Evans (URS) O&M Contractor (Eng.) 2/20/03 2:00 PM Holly Renn (URS) O&M Contractor (PM) 2/24/03 2:42 PM

Jeffrey Watkins (EMR) Post-ROD PM 3/4/03 10:00 AM OU 4*

Oscar Torres (EMR) Current PM 3/4/03 10:00 AM Oscar Torres (EMR) Current PM 2/6/03 9:00 AM Curt Himle (URS) O&M Contractor (Tech) 2/12/03 1:00 PM Tyler Esplin (URS) O&M Contractor (Eng.) 2/6/03 10:00 AM

Mark Loucks (EMR) Historical PM 2/6/03 10:30 AM

OU 5 (Phase I & Phase II)

Steve Knutson (URS) O&M Contractor (Tech) 2/12/03 12:00 PM Oscar Torres (EMR) Current PM 1/28/03 10:00 AM Curt Himle (URS) O&M Contractor (Tech) 1/24/03 10:20 AM Sage Evans (URS) O&M Contractor (Geologist) 1/27/03 2:00 PM

OU 6 (Craigdale,

Cooley's, and On-Base) Tyler Esplin (URS) O&M Contractor (Eng.) 1/27/03 10:20 AM

Steve Knutson (URS) O&M Contractor (Tech) 2/21/03 10:00 AM Holly Renn (URS) O&M Contractor (PM) 2/24/03 3:20 PM

Jeffrey Watkins (EMR) Post-ROD PM 3/4/03 10:40 AM OU 7*

Oscar Torres (EMR) Current PM 3/4/03 10:40 AM Steve Knutson (URS) O&M Contractor (Tech) 1/28/03 9:52 AM

Holly Renn (URS) O&M Contractor (PM) 1/28/03 10:31 AM OU 8 Rob Petrie (EMR) Current PM 1/28/03 12:20 PM

OU 9 Shannon Smith (EMR) Current PM 2/4/03 9:30 AM OU 10 Shannon Smith (EMR) Current PM 1/28/03 9:22 AM OU 11 Sheri Rolfsness (EMR) Current PM 1/16/03 10:00 AM

Mark Loucks (EMR) Historical PM 2/11/03 1:00 PM OU 12 Dave Mills (EMR) Current PM 2/11/03 9:00 AM

* Steve Hicken of EMR also was interviewed for OU 3, OU 4, and OU 7 for a historical perspective on several questions in a short afternoon session on 3/4/03 with Jeffrey Watkins and Oscar Torres.


Table 6. Inspections conducted for the FYR Operable

Unit Description Site ID Date and Time of Site Inspection

OU 1

Landfill No. 4 Chemical Pits 1 and 2 Landfill No. 3 Fire Training Area 1 Waste Phenol Oil Pit

LF001, WP002, LF003, FT081, WP080

2/17/03 2:15 PM

OU 2 Chemical Pit 3 WP007 2/5/03 1:00 PM Sodium Hydroxide Spill ST004 2/5/03 10:46 AM OU 3 Berman Pond WP005 2/5/03 10:28 AM Landfill No. 1 LF011 2/5/03 11:33 AM OU 4 Horizontal Drain Upgrade System LF011 2/5/03 1:09 PM US Army Tooele Rail Shop - Phase I SS017 2/11/03 1:00 PM OU 5 US Army Tooele Rail Shop - Phase II SS017 2/11/03 1:30 PM Sump Leach Field ST022 2/3/03 1:10 PM Asphalt Pad - on-Base Pump and Treat (PTS) System OT026 2/3/03 12:26 PM

Asphalt Pad - Cooley's Pond OT026 2/3/03 2:54 PM OU 6

Asphalt Pad - Craigdale OT026 2/3/03 2:13 PM OU 7 Building 225 Cr Spill SS027 2/5/03 10:59 AM OU 8 Layton TCE Plume OT033 2/5/03 9:57 AM

800/900 Warehouse Area SS108 2/3/03 10:54 AM Pond 3 SD023 2/3/03 10:35 AM Pond 7 SD040 2/3/03 10:23 AM 1100 Area SS089 2/3/03 9:59 AM Building 786* SS092 2/3/03 9:48 AM Zone 7 Golf Course Area SS090 2/3/03 9:31 AM

OU 9

Pond 1 SD034 2/3/03 9:15 AM OU 10 1200 Area SS109 2/3/03 10:08 AM OU 11 Gas Station (454) OT097 1/24/03 11:00 AM OU 12 Aspen Ave. Disposal Area SS107 2/11/03 3:00 PM

* Building 786, SS092, was the only site with NFRAP status that was inspected. Technical Assessment A technical assessment was conducted for each site based on the information collected during

document review, interviews, and inspections. Each technical assessment addressed the following three questions (EPA 2001):

A. Is the remedy functioning as intended by the decision documents? B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives

(RAOs) used at the time of the remedy still valid? C. Has any other information been uncovered that could call into question the protectiveness of

the remedy?

Question A was answered primarily by comparing long-term monitoring (LTM) and operation and maintenance reports with RAOs. The intention of the review with respect to Question A was to determine whether in-place remedies are performing as anticipated. Data produced in LTM reports were used to determine if remedies were in compliance with specifications (e.g., groundwater contaminant concentrations, groundwater elevations, fencing around hazardous waste sites, etc.) provided primarily, but not exclusively, in the USEPA Record of Decision and augmented by the Hill AFB Performance


Standard Verification Plan (PSVP). The PSVPs are important in a protectiveness review because they are the document in which the translation of clean-up standards from the RODs into metrics for evaluating performance is presented. For future Five-Year Reviews, Hill AFB can address Question A in even greater detail when Performance Standard Verification Reports (PSVRs) are available for each OU. The PSVR will assess performance using statistical analysis, modeling, and other tools to quantify and update the progress in achieving RAOs. For this Five-Year Review, no additional statistical evaluations of monitoring data were performed beyond those available in published reports.

The O&M reports were reviewed to determine if the technology was functioning appropriately to

meet cleanup levels. Optimization of the operations was not a focus of the Five-Year Review. Question B was addressed by comparing applicable, relevant, and appropriate requirements

(ARARs) in place at the time of the signing of the RODs with updated requirements in place in September 2002. The primary comparison was for chemical-specific ARARs for which cleanup levels at the time of remedy selection were compared with cleanup standards in place as of September 2002. Cases where standards have changed were identified; however, no human health risk assessment was conducted to evaluate the impact on cleanup levels due to recent changes in recommended toxicity or exposure levels. The intention of the review with respect to Question B was to determine whether exposure assumptions, toxicity data, and cleanup levels used at the time of the ROD or an Action Memorandum was signed were still valid as of September 2002. It is possible that remedies could be compliant with RAOs established at the time of a ROD but no longer afford the same level of “protectiveness” based on more recent EPA toxicity evaluations of specific contaminants of concern. A risk assessment would need to be conducted using recently developed toxicity data and updated USEPA risk assessment procedures to determine if remedies activated in accordance with RODs where cleanup levels may need to be modified are still protective.

The review for Question B also included action- and location-specific ARARs for which there

had been rule changes since RODs were signed. Since corrective action managements units (CAMUs) were established at OUs 1 and 2, the rule for CAMUs in place at the time of the RODs for these OUs was compared to the final rule, amended in January 2002. It is possible that remedies could be in compliance with these ARARs at the time of the signing of the RODs but not comply with the updated regulations.

Question C was answered primarily by review of longer-term monitoring reports or other

treatability studies published since remedial actions were initiated. Results of interviews and inspections also played an important role in addressing Question C. The intention of the review with respect to Question C was to determine if there are issues beyond system operation and clean-up standards that could impact the success of a remedy.

This Technical Assessment resulted in a set of yes/no answers that formed the basis for

evaluating protectiveness for each IRP Site. In addition, the process of addressing each question resulted in a list of issues associated with each site. A set of recommendations was generated to address issues associated with the Technical Assessment.

Protectiveness Selection Based on the results of the Technical Assessment, the protectiveness of each site was evaluated

and categorized as one of the following: l Protective l Will be protective once the remedy is completed


l Protective in the short-term; however, in order for the remedy to be protective in the long-term, follow-up actions need to be taken

l Not protective, unless the following actions are taken in order to ensure protectiveness l Protectiveness cannot be determined until further information is obtained l Not Applicable

The “Not Applicable” categorization was used for those sites which were included in this review

either for completeness (e.g., sites with previous NFRAP designation and no remedial actions) or for which no remedial actions have been constructed at this time (e.g., sites currently under RI). Following the data evaluation and protectiveness selection, protectiveness statements were written for each OU in accordance with the EPA Guidance explaining the primary reason(s) for the categorization.

Report Preparation Hill AFB is a complex facility and therefore this review was conducted for individual IRP sites

rather than for the Base as a whole. This CERCLA Five-Year Review Report was developed by first looking at review results at each individual IRP site (Site Summaries), then considering the collective protectiveness at the OU level (OU Summaries, Section VII). Protectiveness statements were developed for each of the 42 sites reviewed and for each of the 12 OUs at Hill AFB.

As a result of the tiered review process (sites followed by OUs), much of the information in the

Site Summaries duplicates that presented for the Operable Unit. The reader is encouraged to focus on the OU Summaries for understanding protectiveness and use the Site Summaries as a source of additional detail, particularly background and issues and recommendations specific to each IRP site.

September 2003 III-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

III CONCLUSION & RECOMMENDATIONS This 2003 CERCLA Five-Year Review for Hill AFB was completed following the process

described in Section II during the period of October 2002 through April 2003. The document review included work conducted at Hill AFB that was published prior to 30 September 2002 and interviews and inspections that were conducted during January, February, and March of 2003. The Hill Administrative Record served as the source of much of the required documentation. In the event that information necessary to complete the review of a site was not available through the Administrative Record, Hill EMR project files were accessed for historical records. A list of all documents reviewed is included in Appendix C. Information gathered during the review is in the FYR Access® database along with the reference for each item. The conclusions of the review are the result of a reproducible, defensible process where data were evaluated to assess whether remedial actions conducted at IRP sites at Hill AFB are protective of human health and the environment.

Basewide Findings The EMR department is managing the CERCLA-related remediation efforts at Hill AFB. This

review highlighted several items that were apparent across the Base, not specific to a particular site, Operable Unit, or remedial action, which are important to EMR’s ability to monitor and maintain protectiveness. These basewide findings are described here while details of the OU- and site-specific reviews are contained in Section VII.

Changes in Chemical-Specific Clean-up Levels As part of the Technical Assessment, the cleanup level for each chemical of concern (COC) listed

in the ROD and decision documents was examined. The standard-based cleanup levels for groundwater were compared to the current Utah drinking water standards (UT 2002). To assess the current relevancy of risk-based cleanup levels developed for OUs in the past, the toxicity factors used in the risk assessments were compared to the toxicity factors listed in the EPA Region III RBC Tables (EPA Region III 2002). Details of the study are included in Appendix E, and changes in standards or toxicity factors that could affect the cleanup levels for OUs at Hill AFB are summarized in Table 7. OUs 9 through 12 were not included in this analysis because there are no decision documents for these OUs and consequently no (by definition) contaminants of concern. It should be noted that the arsenic cleanup levels are currently still valid. However, the new arsenic standard of 10 µg/L has been promulgated and will take effect January 2006.

Also, Hill AFB EMR, EPA and Utah Department of Environmental Quality established a new

action level for TCE in indoor air at 0.43 parts per billion by volume (ppbv) in December 2002 (MWH 2002). This new action level may affect any OU with a groundwater contaminant plume that has extended off-Base under residential areas. Currently, Hill AFB EMR is developing the Basewide Air Sampling and Analysis Plan (MWH 2002) for indoor air sampling in homes where migration of volatile organics into indoor air was considered in the risk assessment.

Based on the result of this portion of the technical assessment, the risk analyses for OU 1 through OU 8 should be re-evaluated due to new standards and more stringent toxicity factors. The chemicals of potential concern (COPCs) that were dismissed after the original risk assessments were not reassessed during this review. The standards and toxicity factors for the COPCs at OU 1 through OU 8 should be examined to determine if risk calculations should be updated and if new actions levels are warranted.


Table 7. Comparison of Cleanup Levels and Standards

OU COC listed in Decision Documents with changes to MCLs or risk factors 1 2 3 4 5 6 7 8

1,1-Dichloroethene (1,1-DCE) - Arsenic (effective 1/26/2006) + + + + Barium - Beta-BHC + Boron + Chromium (total or VI) + - Fluoride - Methylene chloride + + Naphthalene + Polychlorinated Biphenyl (PCB) - 1,1,2,2-Tetrachloroethane 0 Tetrachloroethene (Perchloroethene or PCE) + Trichloroethene (TCE) + + 0 Potential Risk to Indoor Air Quality √ √ √ √ √ √ Answer to Tox/Standard portion of Question B* N N N N Y Y N Y Cleanup levels stated in decision documents were compared to 2002 Maximum Contaminant Levels (MCLs) and toxicity factors: (-) 2002 MCLs or risk factors are less stringent, (+) 2002 MCLs or risk factors are more stringent, (0) risk assessment required to understand impact, (shaded) not a COC, (√) risk should be evaluated, (Y/N) yes/no. *Conclusion assumes exposure assumptions have not changed.

Site Management Site management at Hill AFB focuses on providing protectiveness to human health and the

environment. For each OU, a site management plan, whether conceptual or as a published document, provides a framework for making decisions about an OU and generally contains guidelines for daily site management, tools for optimizing long-term monitoring and long-term operations (LTO), and a closure strategy that has regulatory and community approval. Site management objectives are to provide protectiveness by evaluating performance data, reducing LTM/LTO program costs, and reducing the time to closure. An important component of reducing LTO costs and time to closure is to implement the most efficient technology for an OU. Each OU at Hill AFB is managed by a Project Manager who is cognizant of issues associated with that OU and has authority to develop a formal site management plan and select contractors to implement phases of that plan.

Daily Site Management Daily activities required to maintain protectiveness include primarily O&M tasks and long-term

monitoring tasks. In general for the OUs at Hill AFB, separate contracts are in place for O&M tasks and for the long-term monitoring tasks. Based on document reviews, interviews, and inspections, the individual contractors appear to be aware of most of the protectiveness issues associated with the tasks they conduct. For example, O&M contractors are aware of issues associated with permit requirements and efficiency for a particular treatment system and LTM contractors have constructed and are using monitoring systems that allow sub-surface conditions to be tracked in accordance with the Basewide Monitoring Program. However, this Five-Year Review suggests that greater integration of these data sets could support efforts to ensure protectiveness by increasing treatment efficiency and reducing treatment times. Further, there is information that is collected by both LTM and LTO contractors that is not


analyzed and reviewed except as part of annual O&M reporting or the PSVP/PSVR process, which is conducted every five years. A less rigorous but more frequent review of LTO and LTM data could lead to regular changes in operations that modify treatment, ensure protectiveness, and reduce time to site closure.

In addition, this Five-Year Review for several of the OUs suggests that a review should be

conducted by each Hill OU Project Manager to confirm responsibility for meeting PSVP data collection requirements. In cases where different contractors are performing O&M and LTM tasks, the assignment for monitoring and reporting data required in the PSVP must be explicit to ensure monitoring and reporting are comprehensive. A careful check should be conducted by the EMR Project Manager to ensure that each PSVP-based requirement is being fulfilled through one of the contracts.

Optimizing Long-Term Monitoring The goal of a LTM program as part of site management is to collect the minimum data necessary

to ensure protectiveness, demonstrate remedial progress, and achieve site closure. Minimizing data collection reduces costs. To support this goal, Hill AFB has implemented a basewide monitoring program. The Hill AFB monitoring program is designed and managed to locate contamination, evaluate risk of exposure, and determine and monitor treatment controls to protect human health and the environment. The program consists of monitoring for the presence of contamination in the air, soil, vegetation, and water in seeps, springs, surface water and groundwater at hundreds of sampling locations on and around Hill AFB, often extending into the surrounding communities. Groundwater elevation and slope stability data are also collected. Samples are analyzed for presence of contaminants, changes in elevation or flow patterns, and impact on slope stability in order to track risk of exposure and assess the impact of treatment. All data are maintained in the Hill AFB Environmental Restoration Program Information Management System (ERPIMS) for statistical analysis and used for daily management decisions and long-range planning. Hill AFB partners closely with the public in all aspects of the monitoring program, and the monitoring program is reviewed periodically to ensure it is adequate for evaluating protectiveness while remaining cost-effective.

The monitoring program has two independent but related functions. The first function entails

sampling performed during remedial investigations to locate and characterize areas that may be contaminated. Data are collected during the investigations to define the extent of the plume, understand risk of exposure, and develop site conceptual models. Operable Units 9, 10, 11, and 12 are currently under investigation without any active treatment, and OUs 5 and 8 have active interim treatment systems while investigations continue toward preparation of a ROD. Once a ROD has been developed, monitoring will be managed under the second monitoring function.

The second monitoring function is designed and managed to track contamination, to measure the effect of treatment, and to measure compliance with applicable environmental laws at post-ROD OUs 1, 2, 3, 4, 6, and 7 where the selected remedies are in place. Monitoring is managed as defined in the PSVPs and sampling is generally conducted semi-annually by contractors with EMR oversight. The PSVP defines performance metrics based on clean-up standards in the ROD and specifies locations for monitoring progress toward achieving RAOs, typically, but not exclusively, groundwater monitoring locations. The PSVP specifically defines what parameters to monitor, the location of the monitoring points, and the frequency of monitoring. Sampling results are reviewed every 5 years and necessary adjustments to management and the subsequent PSVRs will be made in the PSVP. The first Hill AFB PSVP was prepared for OU 1 in April 2001, and for the other post-ROD OUs the following year. PSVPs for OUs 5 and 8 have been developed and others will be developed for the remaining OUs as investigations continue. The first PSVRs are scheduled for completion 2006.


The PSVP for each OU should include the parameters and metrics necessary to monitor

performance and protectiveness of the remedial action or treatment remedy design. Based on this Five-Year Review, PSVPs may not address either or both of these functions adequately. Specifically, the PSVPs should carefully address the nature of contamination and degradation byproducts, locations that are monitored, and the frequency of that monitoring and data review. The PSVP/PSVR process should be capable of ensuring that the locations required to understand both the remedy performance and the remedy protectiveness are sampled.

Optimizing Long-Term Operations The primary operational strategies of LTO to ensure protectiveness as part of site management

are active remediation in the source area and plume containment. Focus remains on maximizing the effectiveness of the strategy while minimizing the costs for treatment and monitoring. Consequently, a responsive site management plan allows for future considerations for alternative technology insertion. To this end, Hill AFB has developed a basewide Innovative Technology Program (ITP) that serves as an EMR-wide tool to identify opportunities to achieve cleanup goals in a more cost effective manner. The program was established in the mid-1990s as a way to integrate and coordinate innovative technology demonstrations. Opportunities may include innovative modification of traditional technologies or application of new technologies. An innovative application may be cost-effective if it accelerates progress toward remediation goals or enables an existing application to function more efficiently.

EMR management reviews innovative technologies with three objectives in mind. Projects should be focused on 1) reducing clean-up times, 2) reducing life-cycle costs, or 3) meeting some other compelling requirement in the EMR program. Following review and acceptance of an application at an OU, the ITP Manager works directly with the OU Project Manager to coordinate the activities and communicate findings to other OU managers. By reducing costs associated with studies and remediation, this program helps with the redistribution of Defense Environment Restoration Program (DERP) funds across the Base to ensure that protectiveness is achieved as quickly and as cost-effectively as possible.

Funding for technology demonstration comes both from the Hill AFB budget and from external

funding sources. Examples of external funding sources for previous technology demonstrations have included: Advanced Applied Technology Demonstration Facility (AATDF), Remediation Technology Development Forum (RTDF), the Strategic Environmental Research and Development Program (SERDP), the Environmental Security Technology Certification Program (ESTCP) and the Environmental Protection Agency (EPA, Ada Laboratory). In addition to external funds, Hill EMR supports the demonstrations and research with funds from DERP, administered by the Air Force Materiel Command.

Basewide Issues This Five-Year Review, following the process described in Section II, culminating in a Technical

Assessment of the protectiveness for each IRP site and for each OU, has identified issues that need to be addressed in order to gain or ensure continuing protectiveness for Hill AFB. Three issues exist at several OUs, though not necessarily at every OU reviewed, and are therefore presented generally in Table 8.


Table 8. Major basewide issues identified during 2003 CERCLA Five-Year Review

Potentially Affects Protectiveness? (Y/N) Issue

Currently Future Evidence of ponding and damage on landfill caps N Y Unlocked gates and inadequate signage Y Y Insufficient evaluation of performance data conducted to date for most OUs

N Y

Basewide Recommendations The following recommendations are based on the general, basewide issues identified above.

Each was developed based on the findings in this Five-Year Review and either has an impact on protectiveness or on the ability to determine protectiveness. All should be implemented prior to the next Five-Year Review in 2008.

• Determine the potential for exposure to TCE vapors for residents near OUs with groundwater

contamination that extends off-base. • Re-evaluate the risk analyses for OU 1 through OU 8 in view of new standards and more

stringent toxicity factors. • Conduct periodic, integrated review of O&M and LTM data to support remedy performance

and protectiveness tracking. • Conduct a check of O&M and LTM contracts to ensure that all PSVP-based items are being

completed under one or the other. • Review each PSVP and update if necessary to ensure the PSVP includes the parameters

necessary to monitor the performance and the protectiveness of the selected remedy. • Assess the impact of ponding and damage on landfill caps and correct activities and repair

accordingly. • Ensure that all gates are locked and adequate, descriptive signage is present where required.

OU Specific Issues and Recommendations This Five-Year Review also has identified issues that need to be addressed in order to gain or

ensure continuing protectiveness for the individual OUs at Hill AFB. The specific issues identified for each OU are listed in the respective OU Summary in Section VII. Table 9 highlights some of the more complex issues as well as recommendations to address each issue. Each OU Summary (Section VII) contains a comprehensive list of issues that was used to develop recommendations and assess protectiveness for each OU. The list of issues and recommendation in each Site Summary can be used to specifically address protectiveness at an individual IRP site. The list of recommendations in each Site Summary can be used to develop a list of action items that should be addressed as soon as possible and prior to the next Five-Year Review in 2008.


Table 9. Major issues and recommendations identified during 2003 CERCLA Five-Year Review Potentially Affects

Protectiveness? (Y/N) OU IRP Site Issue Recommendation Currently Future

1

LF001, WP002, LF003, FT081, WP080

Measurable hydrocarbon concentrations and LNAPL are present downgradient and to the west of the exterior trench. Therefore, monitored natural attenuation in that portion of the non-source area may not be adequate to remediate the contaminated groundwater.

Re-evaluate the non-source area monitored natural attenuation remedial action to determine if still applicable in all non-source areas. Y Y

A thorough review of the remedial actions now implemented is not scheduled until 2006, 13 years after the SRS began operation in 1993 and 10 years after the containment wall and the North Interceptor Trench were completed in 1996.

Complete a PSVR to comprehensively evaluate the system of remedies at OU 2, particularly the containment wall, the North Interceptor Trench, and the SRS. N Y

2 WP007 The leading edge of the plume is near the boundary of NE ¼, Sect. 29, T5N R1W, which is not subject to water rights restrictions. Should the plume advance, it could impinge on this quarter section.

Monitor plume extent, particularly with respect to NE ¼, Sect. 29, T5N R1W, and apply water use restrictions as appropriate. N Y

3 WP005

The groundwater levels in the extraction sumps at Berman Pond have been above the PSVP-mandated GW elevation action level for the past four years. Pumps were removed after the cap was installed in 1997. Pumps have not been re-installed in the sumps because EMR believes that groundwater from OU 3 is captured in the OU 8 extraction system.

Revise the PSVP to reflect the change of remedial actions at the site. Y Y

Increasing contaminants trends in distal portions of the plume suggest migration while a recent report concludes the plume is “relatively static”.

Thoroughly evaluate existing data and determine if additional data and/or modeling is required to develop a plume management plan that meets the RAOs. N Y

The effectiveness of the landfill cap in limiting infiltration and reducing the contaminant leaching is questionable.

Complete an investigation into the increase of TCE concentrations in U4-047 and closely monitor future analytical results from this location for trends. Y Y LF011

Protectiveness of some seeps is based on low flow and not on access control. Conduct a risk-based assessment for seep U4-308 and install institutional controls if risk-based action levels are exceeded. N Y

4

OT041, LF012

An additional source of contamination is suspected near these two sites. Both sites have NFRAP status.

Continue to monitor wells in the plume area and if sustained increasing trends are observed, which result in an expansion of plume boundaries, an evaluation should be completed to determine if additional source characterization is warranted.

N Y

Operational issues have reduced the effectiveness of the aeration curtain, which is allowing concentrations of TCE greater than 5 µg/L to pass through.

Evaluate the life expectancy of the aeration curtain system and, if appropriate, replace the blowers with air compressors. Clean the sparge lines and develop a preventive maintenance process to prevent unplanned system shutdowns.

N N 5 SS017

The Phase II groundwater extraction system does not appear to be affecting the plume and is predicted to only remove another 1% of contaminant mass over the next 30 years. Plan the deactivation of Phase II groundwater extraction system. N N

Active treatment in the northern arm of the east contaminant plume needs to be evaluated, as required by the ROD, because the TCE concentrations have remained above 5 µg/L after 5 years [after 2002].

Evaluate the need for active treatment in the northern arm of the off-Base contamination plume. N Y

The air stripper discharge pump is running at its maximum capacity and cannot handle additional flow, while flows from the well field should be increased to reach action levels.

Evaluate treatment system to determine why target groundwater levels at the extraction wells, which are an indicator of plume capture, have not been achieved. Y Y 6 OT026

Fouling at the extraction wells has reduced the volume of groundwater that can be extracted. Develop a long-term maintenance strategy to closely monitor the fouling problem at the extraction wells and to ensure that adequate treatment is implemented. N N

7 SS027 Hexavalent chromium concentrations in groundwater beneath Bldg. 225 have exceeded MCLs since 1996, and the downgradient concentrations are increasing, suggesting contaminant migration.

Identify the source of the elevated concentrations of hexavalent chromium in the groundwater underlying the SS027 site. Y Y

8 OT033 A potential exposure pathway with no institutional controls exists at U3-610. Review analytical sampling results for U3-633 to quantify exposure risks at this location. Y Y

September 2003 IV-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

IV PROTECTIVENESS STATEMENTS

Protectiveness statements have been developed for each IRP site reviewed in this 2003 Five-Year Review as well as for each Operable Unit. The basis for these statements is provided in the OU Summaries included as Section VII of this report. Table 10 provides a summary of the protectiveness determinations for Hill AFB. Table 11 provides the protectiveness determination for the sites and OUs. A not applicable determination was given to sites that already had a No Further Remedial Action Planned (NFRAP) status as well as sites where remedial investigations and feasibility studies were still being completed and a remedy was not installed. Because some OUs at Hill AFB do not have remedies selected and constructed, a basewide protectiveness statement is not included in this review.

Table 10. Summary of Protectiveness Determinations for Hill AFB

Protectiveness Determination Number of IRP Sites

Number of OUs Operable Units

Protective 8 2 3 and 7 Protectiveness cannot be determined 6 4 1, 2, 6, and 8 Protective in the short term 2 2 4 and 5 Will be protective once remedy complete 1 1 9 Not protective 1 1 12 Not applicable 24 2 10 and 11

One OU, OU 12, is not protective because there are high levels of TCE in shallow groundwater,

and although there are groundwater use restrictions in place, there are areas within the plume and beneath residences where groundwater is very shallow and indoor air quality is a concern. Currently, with groundwater use restrictions and air treatment units in homes with identified indoor air concerns, there is no apparent danger of exposure.

Table 11. Site Five-Year Review Status for Hill AFB OU Site ID Site Name Protectiveness Management Stage * Next FYR Review

1 OU 1 OPERABLE UNIT 1 Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

1 LF001 LANDFILL NO 4 Protective LTO/LTM 2008

1 WP002 CHEMICAL PITS 1 AND 2 Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

1 LF003 LANDFILL NO 3 Protective LTO/LTM 2008 1 FT009 FIRE TRAINING AREA 1 Not applicable NFRAP None required 1 OT014 GOLF COURSE Not applicable NFRAP None required

1 FT081 FIRE TRAINING AREA 2 Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

1 WP080 WASTE PHENOL OIL PIT Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

2 OU 2 OPERABLE UNIT 2 Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

2 WP007 CHEMICAL PIT 3 Protectiveness cannot be determined until further information is obtained LTO/LTM 2008

2 SS021 PERIMETER ROAD Not applicable NFRAP None required 3 OU 3 OPERABLE UNIT 3 Protective LTO/LTM 2008 3 ST004 SODIUM HYDROXIDE SPILL Protective LTO/LTM 2008 3 WP005 BERMAN POND Protective LTO/LTM 2008 3 WP006 IWTP SLUDGE DRYING BEDS Not applicable NFRAP None required 3 ST018 BLDG 514 Protective NFRAP None required 3 SD046 POND 2 Not applicable NFRAP None required 4 OU 4 OPERABLE UNIT 4 Protective in the short term LTO/LTM 2008 4 LF011 LANDFILL NO 1 Protective in the short term LTO/LTM 2008 4 LF012 LANDFILL NO 2 Not applicable NFRAP 2008 4 OT020 SPOIL PIT Not applicable NFRAP None required 4 OT041 NORTH GATE DUMP OP UNIT 4 Not applicable NFRAP 2008 4 OT042 MUNITIONS DUMP OP UNIT 4 Not applicable NFRAP None required 5 OU 5 OPERABLE UNIT 5 Protective in the short term RI/EARLY ACTION 2008 5 SD016 BAMBERGER POND Not applicable NFRAP None required 5 SS017 US ARMY TOOELE RAIL SHOP Protective in the short term RI/EARLY ACTION 2008 5 SS091 BLDG 1607 - EVAP. POND Not applicable RI 2008

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Table 11. Site Five-Year Review Status for Hill AFB (Cont.)

OU Site ID Site Name Protectiveness Management Stage * Next FYR Review

6 OU 6 OPERABLE UNIT 6 Protectiveness cannot be determined until further information is obtained. LTO/LTM 2008

6 ST022 SUMP LEACH FIELD Protective LTO/LTM 2008

6 OT026 ASPHALT PAD Protectiveness cannot be determined until further information is obtained. LTO/LTM 2008

6 SD40B BLDG. 1946 EVAPORATION POND Not applicable NFRAP None required

7 OU 7 OPERABLE UNIT 7 Protective LTM 2008 7 SS027 BLDG 225 CR SPILL Protective LTM 2008 7 ST031 B220 UNDERGROUND TANKS Not applicable NFRAP None required 7 SS032 BLDG 225 PCB Not applicable NFRAP None required 7 SS028 SILL PROPERTY, LAYTON Not applicable NFRAP None required 7 OT029 B-204 BE Not applicable NFRAP None required

8 OU 8 OPERABLE UNIT 8 Protectiveness cannot be determined until further information is obtained IRA/PP 2008

8 OT033 LAYTON TCE PLUME Protectiveness cannot be determined until further information is obtained IRA/PP 2008

9 OU 9 OPERABLE UNIT 9 Will be protective once remedy is completed RI 2008 9 SD023 POND 3 Not applicable RI 2008 9 SD034 POND 1 Will be protective once remedy is completed RA-C 2008 9 SS092 BLDG 786 Protective NFRAP None required 9 OT106 DEFERRED AREAS Not applicable LTM 2008 9 SD040 POND 7 Not applicable RI 2008 9 SS089 1100 AREA Not applicable RI 2008 9 SS090 ZONE 7 GOLF COURSE Not applicable RI 2008 9 SS108 800/900 WAREHOUSE AREA Not applicable RI 2008

10 OU 10 OPERABLE UNIT 10 Not applicable RI 2008 10 SS109 1200 AREA Not applicable RI 2008 11 OU 11 OPERABLE UNIT 11 Not applicable RI 2008 11 OT097 GAS STATION (454) Not applicable RI 2008 12 OU 12 OPERABLE UNIT 12 Not protective RI/TS-C 2008 12 SS107 ASPEN AVE. DISPOSAL AREA Not protective RI/TS-C 2008

* Management Stages: IRA = Interim Remedial Action, under Interim ROD NFRAP = No Further Remedial Action Planned RA-C = Remedial Action under Construction, under ROD LTM = Long Term Monitoring PP = Proposed Plan RI = under Remedial Investigation LTO = Long Term Operation RA = Remedial Action in place, under ROD TS-C = Treatability Study under Construction

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September 2003 V-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

V TIMING FOR NEXT REVIEW FOR HILL AFB

The next Five-Year Review for Hill Air Force Base is required by September 2008, five years from the date of this review. Table 10 illustrates that this 2003 Five-Year Review was the final review required for many of the IRP sites included. The 2008 Review will need to encompass all 12 OUs, but only 27 IRP sites from this reviewed set of 42.

September 2003 VI-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

VI REFERENCES FOR SECTIONS I THROUGH V (EPA 2001) Comprehensive Five-Year Review Guidance, EPA 540-R-01-007, OSWER No. 9355.7-03B-P, Environmental Protection Agency, June 2001. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. (MWH 2002) Draft Final Basewide Air Sampling and Analysis Plan Indoor Residential Air Sampling, Montgomery Watson Harza, Oct 2002. (UT 2002) Utah Rule R309-200, Monitoring and Water Quality: Drinking Water Standards, State of Utah, July 2002.

September 2003 VII-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

VII FIVE-YEAR REVIEW OF OPERABLE UNITS

The FYR summary for each Operable Unit is included in this section. The information for each OU is contained after the tab with the corresponding number. At a minimum, each numbered tab includes the OU summary, a site figure, and an OU chronology. If the OU has more than one site, site chronologies and site summaries are also included.

September 2003 OU 1-1 CERCLA Five-Year Review Final Hill Air Force Base, Utah

Operable Unit 1

I Introduction

OU 1 is located near the eastern Base property boundary and includes two IRP sites with NFRAP status (FT009 and OT014) (see Table OU 1-1) and 5 open IRP sites with active remediation in place to address contaminated groundwater and soil (HAFB EMR 1998a). Past investigations have focused on the five open sites as a group and subsequently RAOs were written and remedial actions were selected for the region impacted by all sites collectively.

Table OU 1-1. OU 1 Site Identification

Site ID Site Name LF001 LANDFILL NO. 4 WP002 CHEMICAL PITS 1 AND 2 LF003 LANDFILL NO. 3 FT009 FIRE TRAINING AREA 1 OT014 GOLF COURSE FT081 FIRE TRAINING AREA 2 WP080 WASTE PHENOL OIL PIT

II Site Chronology

See Table OU 1-2 for a history of events in this OU. The table is organized to describe events that impacted the OU as a whole, followed by events impacting specific IRP sites within the OU.

III Background OU 1 is located near the eastern Base property boundary, and includes the former waste disposal areas: Landfills No. 3 and No. 4, Fire Training Areas (FTAs) 1 and 2, Chemical Disposal Pits 1 and 2, the Water Phenol/Oil Pit (WPOP), and the Waste Oil Storage Tank (WOST) site. The source area includes Landfills No. 3 and No. 4, CDPs 1 and 2, FTAs 1 and 2, the WPOP, the WOST (see Figures OU 1-1 and OU 1-2), and the light, non-aqueous phase liquid (LNAPL) emanating from the CDPs. The non-source area includes an on-Base groundwater plume west of the CDPs and the off-Base groundwater plume in the Weber River Valley. These groundwater plumes are depicted in Figures OU 1-1 and OU 1-2. Although these two figures illustrate TCE and cis-1,2-DCE, other COCs may be present within the boundaries of these plumes. Historically, hazardous materials and wastes were dumped and/or burned at all of the source areas. These included scrap metal, construction debris, domestic refuse, industrial refuse, sludge drying bed and flocculation wastes from the Industrial Wastewater Treatment Plant, sulfuric acid, chromic acid, phenol, methyl ethyl ketone (MEK), waste oil, fuel, spent solvents including Stoddard solvent and paint thinner, paint sludges, paint booth scrubber sludge, plastics, and spent sandblast media (MW 1995). The shallow groundwater under and downgradient of the five open sites was contaminated as a result of the historical disposal activities. Because of the proximity of the five sites, investigations have focused on them as a group; RAOs were written, and remedial actions were selected for the region impacted by all sites collectively. All of the sites, except Fire Training


Area 2 (FT081), were capped during construction activities at Landfills No. 3 and No. 4 and groundwater contamination at the site is being addressed through five remedial actions which are: 1) extraction trenches that collect contaminated shallow groundwater (dewater) and LNAPLs (source area), 2) landfill caps (source areas), 3) remediation of contaminated surface water and soil at downgradient springs (non-source area), 4) monitored natural attenuation for contaminated groundwater off-Base (non-source area), and 5) institutional controls.

IV Remedial Actions

Remedial actions have been implemented at OU 1 to address both on-Base and off-Base contamination. The remedial actions are discussed in detail in the Site Summaries (see Section XIII) for OU 1. In summary, the remedial actions are:

1. Source Area - Groundwater Extraction Trenches Installation of five groundwater extractions trenches located in the OU 1 source area to

dewater the Provo Formation by extracting groundwater and LNAPLs. The extracted contaminated groundwater is passed through an oil water separator (OWS) before being conveyed to the IWTP for treatment. Treated water from the IWTP is discharged to the North Davis Sewer Improvement District for further treatment and final discharge.

2. Source Area - Landfill Cap The remedial action at Landfill No. 4 consisted of the low permeability soil cover constructed

in 1985 and the repair of the areas of differential settlement in 2001. The remedial action at Landfill No. 3 included construction of a new portion of low-permeability cap over the CDP area and the repair of portions of the cap (installed in 1985) disturbed by the installation of the groundwater extraction trenches. The purpose of the repair of the landfill caps was to minimize the infiltration of surface water into the landfill contents and the leaching of contamination into the groundwater. The landfill caps cover all of the sites at OU 1 except for Fire Training Area 2 and the Waste Phenol Oil Pit.

3. Non-Source Area - Spring Remediation System The selected remedial action for the springs (U1-303, U1-304, U1-305, U1-307, and U1-318)

is to treat the groundwater from the springs with contamination levels above MCLs. Due to reducing conditions in the groundwater at OU 1, elevated arsenic concentrations in the groundwater have been measured. To mitigate arsenic from mobilizing from the sediments to the groundwater, sediments from spring areas with arsenic contamination above 11 mg/kg will be identified and excavated after the springs have ceased to flow. The removal of the arsenic contaminated soils at the springs is anticipated two to three years after the springs cease to flow.

4. Non-Source Area - Monitored Natural Attenuation The selected remedial action for the non-source area groundwater plumes is monitored

natural attenuation (MNA). This remedial action requires long-term monitoring of the groundwater plumes to determine if naturally occurring attenuation processes are meeting the remedial action objectives as stated in the ROD.

5. Common to Both Source Area and Non-Source Area - Institutional Engineering Controls Institutional and engineering controls include restriction of access to landfill cap areas using

fencing and warning signs, enforcement of the Hill AFB Commander’s office continuing order that limits development within OU 1 (HAFB 1998), distribution of the Hill Restricted


Use Access Map to the appropriate Hill AFB personnel to identify OU 1 as an area restricted to development, and restricting domestic usage of the shallow groundwater in the OU 1 area with drilling restrictions per the Utah Division of Water Rights.

The remedial actions at OU 1 were developed to achieve the RAOs set forth in the ROD. The individual site summaries include a description of each RAO for OU 1.

V Progress Since Last Five-Year Review

OU 1 interim remedies were reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs, which is not planned until after two to three years operation of the groundwater extraction system (GES).

VI Five-Year Review Process

Site review was conducted per the process described in this report for the overall 2003 FYR.

VII Technical Assessment

Results of the technical assessment for each site in OU 1 and for the operable unit are listed in Table OU 1-3. Details of the technical assessment for each site in OU 1 are provided in the respective site summary (see Section XIII). Table OU 1-3. Technical Assessment Summary for OU 1

Technical Assessment* Site ID Remedy

Question A Question B Question C Protectiveness

Next Five-Year

Review

FT081, WP002, WP080

Groundwater Extraction Trenches, Spring Remediation,

Landfill Cap, Monitored Natural

Attenuation, Institutional Controls

Yes No Yes

Protectiveness cannot be

determined until further

information is obtained

2008

LF001, LF003

Landfill Cap, Institutional Controls Yes No Yes Protective 2008

FT009 NA NA NA NA NA NA

OT014 NA NA NA NA NA NA

OU 1

Groundwater Extraction Trenches, Spring Remediation,

Landfill Cap, Monitored Natural

Attenuation, Institutional Controls

Yes No Yes

Protectiveness cannot be

determined until further

information is obtained

2008

*Question A: Is the remedy functioning as intended by the decision documents? Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? Question C: Has any other information come to light that could call into question the protectiveness of the remedy? NA = Not Applicable


Question A. Is the remedy functioning as intended by the decision documents?

Yes. The primary goal of the OU 1 remedies is to dewater the source area and prevent groundwater contamination of uncontaminated areas (non source areas). Since June 2001, the groundwater extraction system has extracted 28,216,379 gallons of groundwater and 6,301 gallons of LNAPL (as of 31 December 2002) (URS 2002a and 2002b). Water elevations in the sumps at OU 1 have not been maintained in several sumps below the trench pipe entry elevation (U1-217, U1-218, U1-219, and U1-224). However, additional groundwater extraction pumps were installed in U1-217 and U1-219 to increase extraction capacity. The flows at springs U1-303 and U1-304 have decreased to a yearly average of less than 0.1 gpm, and springs U1-305 and U1-318 have ceased to flow. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid?

No. A new, lower arsenic standard of 10 ug/L (ppb) will be effective 01/26/2006. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/day, and the RfD(i) is now available at 9.0x10-4 mg/kg/day (EPA Region III 2002). EMR, EPA and UDEQ have established a new action level for TCE in indoor air at 0.43 ppbv.

A corrective action management unit (CAMU) was designated for consolidation of soils that were specified for excavation during remedial actions defined in the OU 1 ROD in September 1998 (HAFB EMR 1998a). The CAMU at OU 1 was designated in compliance with the 1993 CAMU rule applicable at the time of the signing of the ROD. Since the signing of the ROD, the 1993 CAMU rule has been revised (2002). Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C: Has any other information come to light that could call into question the protectiveness of the remedy?

Yes. The conclusions of the OU 1 Source Area Zone Delineation Progress Report (Intera 2002) indicate that hydrocarbon concentrations are measurable downgradient and to the west of the exterior trench (Trench D). This could be an indication that contaminated groundwater from the source area is not being captured by either the interior or exterior trenches or that there is an additional source of contamination off-site (see Figures OU 1-1 and OU 1-2 for location).

VIII Issues

Based on the information reviewed, issues that may affect protectiveness of the selected remedies at OU 1 are listed below:

1. Eighteen months of operational data are not sufficient to determine if the remedies at OU 1

are containing contaminated groundwater. As discussed in the PSVP (CH2M 2001b), five years of data with at least two sampling rounds per year should provide adequate samples across the site and over time to determine if plume mean concentrations are decreasing.


2. If measurable hydrocarbon concentrations and LNAPL are present downgradient and to the

west of the exterior trench (Trench D), it is questionable whether monitored natural attenuation in that portion of the non-source area is adequate to remediate the contaminated groundwater to achieve RAOs.

3. Ponding on the landfill caps was identified during the site inspection portion of this review. 4. A preliminary check between the PSVP sampling requirements and data in ERPIMS showed

that the analytical results from 14 out of 44 sampling locations were not available for review. This may be due to both the lag time between sampling activities and the uploading of the results into ERPIMS and the possibility that the sampling locations were/are dry. However, if the locations are dry, the results (i.e., "well is dry") should be included in ERPIMS.

5. Some of the indoor air sampling results, collected during the RI, exceed the new action level

for TCE in indoor air (0.43 ppbv).

6. The ROD established a CAMU according to the rule in place in 1993. Changes to the materials in, or usage of, the CAMU may not comply with rule changes.

IX Recommendations and Follow-up Actions for OU 1

The recommendations and follow-up actions for OU 1 are:

1. Re-evaluate the non-source area monitored natural attenuation remedial action to determine if it is still applicable in all non-source areas (specifically in the area of measurable hydrocarbon concentrations outside Trench D).

2. Modify ERPIMS to indicate springs and seeps that are dry during a sampling event. 3. Review the long term monitoring sampling and analysis plan to ensure that locations where

the hydrocarbon concentrations were located during the Source Zone Area Delineation project (Intera 2001) are sampled.

4. Proceed with the delineation and excavation of the arsenic contaminated soils at the springs. 5. Determine if the trenches are containing/capturing the contamination in the source area by

evaluating the gradient around the trenches. Additional monitoring points may be necessary to confirm that the prescribed water levels in the sumps are adequate to maintain containment.

6. Re-evaluate the risk analysis for OU 1 to determine if revised contaminant action levels are

warranted based on new standards and toxicity factors, as explained in the Technical Assessment above.

7. Re-evaluate the RI data on indoor air and determine if the new action level for TCE (0.43

ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.


8. Address drainage and ponding issues on Landfills No. 3 and No. 4 as soon as they are identified to ensure the landfill cap integrity.

9. Ensure that all gates and fences are locked in accordance with the ROD-specified institutional

controls. 10. Determine if the plume mean concentrations are decreasing, using the described locations and

monitoring frequency outlined in the PSVP and the results of the PSVR, scheduled for 2006. 11. Ensure that the method detection limits (MDLs) are low enough to detect a contaminant of

concern (i.e., MDL equal to or less than the MCL or PRG). 12. Collect samples from all locations described in the PSVP and ensure that the results are

entered in ERPIMS. 13. Continue to perform landfill cap inspections.

14. Ensure that regulatory approval is granted before the CAMU is used for any future remedial

actions. X Protectiveness

A protectiveness determination of the remedies associated with OU 1 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 1. Therefore, a re-evaluation of potential risk at OU 1 must be conducted before the protectiveness of the current remedies can be determined. Additional items that need to be addressed are described in the previous issues and recommendations and include: the appropriateness of the monitored natural attenuation remedial action in the area of measurable hydrocarbon concentrations outside Trench D, and determining if the trenches are containing/capturing the contamination in the source area. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 1 during the next Five-Year Review (2008).

XI Next Review

The next FYR for OU 1 is required by 2008. No future review is required for the Fire Training Area 1 (FT009) or the Golf Course (OT014) sites because no further remedial actions are planned at these sites.

XII References for Operable Unit 1 Summary

(CH2M 1998) Feasibility Study Report for Operable Unit 1 (IRP Sites LF01, LF03, WP02, FT09, OT14, FT81, and WP80), CH2M Hill, January 1998. (CH2M 2000) Remedial Design Report and Work Plan Operable Unit 1, CH2M Hill, February 2000.


(CH2M 2001a) Operable Unit 1 Fire Training Area 2 No Further Response Action Planned (NFRAP) Decision Document, IRP Site FT081, State of Utah, Department of Environmental Quality, Leaking Underground Storage Tank Site EIIK, Hill Air Force Base, Utah, August 2001, CH2M Hill, August 2001. (CH2M 2001b) Performance Standard Verification Plan Operable Unit 1, CH2M Hill, April 2001. (CH2M 2002) Final Operable Unit 1 Phase I Remedial Action Groundwater Extraction System Operation and Maintenance Plan, CH2M Hill, August 2002. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1998a) Record of Decision Operable Unit 1 IRP Sites LF01, WP02, LF03, FT09, FT81, and WP80, Hill AFB EMR, September 1998. (HAFB EMR 1998b) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (Heyse, C. 1991) Final Decision Document for Site OT14 - Golf Course, Hill Air Force Base, Utah, Hill AFB EMR, May 1991. (Intera 2002) OU 1 Source Zone Delineation Progress Report, Intera, 26 September 2002. (MW 1995) Comprehensive Remedial Investigative Report for Operable Unit 1 (IRP Site LF01, LF03, WP02, FT09, OT14, FT81, and WP80) Volume 1, Montgomery Watson, December 1995. (Radian Int'l 1998) Final Feasibility Study Report for Operable Unit 1 (IRP Sites LF01, LF03, WP02, FT09, OT14, FT81, and WP80), Hill Air Force Base, Utah, Radian International, January 1998. (SAIC 1989) Final Decision Document for Fire Training Area 1, U.S. Air Force Installation Restoration Program, Hill Air Force Base, Utah, July 1989, Science Applications International Corporation, July 1989. (URS 2002a) 2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT, URS, 11 February 2002. (URS 2002b) Monthly OU 1 Operations Summary Reports (Jan - Dec), URS, January 2002.


[This page intentionally left blank.]

MONTH YEAR EVENT COMMENTS REFERENCE

-2: Site Chronology - Hill AFB 2003 Five Year ReviewTable OU 1

OU 1 OPERABLE UNIT 107 1984 Cease and Desist Order issued by

UDWQ (07/23/1984)Cease and Desist Order issued for leachate discharge below Landfill 4 observed at U1-303 and U1-304.


08 1984 Began construction of an on-site groundwater extraction and treatment facility.

Extraction wells U1-201 and U1-202 were completed near CDPs and U1-205 was completed north of LF4


1985 Installation of low-permeability caps over the source areas

Designed to reduce infiltration of precipitation. Record of Decision Operable Unit 1 IRP Sites LF01, WP02, LF03, FT09, FT81, and WP80

1985 Installation of subsurface physical barrier located upgradient of the source areas (Landfills 3 and 4)

Soil/bentonite slurry cut-off wall designed to reduce groundwater recharge to the source areas


12 1985 Treatment system operable U1-206, U1-207, and U1-208 were installed east of LF4 and U1-209 was installed west of LF4. A 1,500 foot extraction trench with two sumps (U1-203 and U1-204) was completed south of FTA2 and a facility was constructed to treat extracted groundwater which included an aeration tank and a skid-mounted dual tank groundwater processor. Effluent discharged via underground pipeline to an airfield sprinkler system. Pumping systems U1-303 and U1-304 were installed at springs northeast of LF4.


13September 2003 Final

OU 1 - CERCLA Five-Year Review Hill Air Force Base, Utah



1986 Air Strippers Added Treat all pumped groundwater from extraction wells. Comprehensive Remedial Investigative Report for Operable Unit 1 (IRP Site LF01, LF03, WP02, FT09, OT14, FT81, and WP80) Volume 1

01 1988 Treatment system disassembled 3-mile waste water line installed to transport effluent to the IWTP.


1989 Pumping system at Pond 10 installed

The pumping system was installed to pump excess water out of the pond and send it to Pond 9. This was designed to keep a constant elevation head in the pond by removing water above a set elevation.

Final Remedial Action Report Pond 10 Pumping Facility Construction at OU 1

1990 Groundwater and surface water monitoring implemented

Established baseline data for site groundwater and surface water. Record of Decision Operable Unit 1 IRP Sites LF01, WP02, LF03, FT09, FT81, and WP80

04 1991 Entered Federal Facilities Agreement with UDEQ

Establish a framework and schedule for developing, implementing, and monitoring appropriate response actions at the site in accordance with existing regulations


09 1993 Pump transfer building constructed (BLDG 753)

Transfer effluent from OU 1 and OU 2 to a 250,000 gallon holding tank at the IWTP






01 1995 Pumping station installed at U1-307 on hillside north of the OU 1 Source Areas

On-site holding pond was removed and filled. Comprehensive Remedial Investigative Report for Operable Unit 1 (IRP Site LF01, LF03, WP02, FT09, OT14, FT81, and WP80) Volume 1

12 1995 Comprehensive Remedial Investigation Report for Operable Unit 1 (MW 1995) published

Determined nature and extent of contamination. Free-phase LNAPL and LNAPL in residual saturation in the sand and gravel aquifer material act as the primary continuing sources of contaminants in the groundwater at OU 1. The risk to human health was low at the time of the RI, but could increase due to shallow water being used for domestic purposes or if housing is built over areas with free or residual phase LNAPL.


01 1998 Feasibility Study (FS) for Operable Unit 1 (CH2M Hill 1998) published

Determined RAOs for soil, groundwater, surface water, LNAPL, and landfill caps and contents. Preliminary remediation goals were outlined for each RAO with technology evaluations and alternatives included as well.

Treatability Study technologies were found not to be viable remediation options.

Final Feasibility Study Report for Operable Unit 1 (IRP Sites LF01, LF03, WP02, FT09, OT14, FT81, and WP80), Hill Air Force Base, Utah

10 1998 Record of Decision Operable Unit 1 (HAFB EM 1998) published

ROD established RAOs and remedial action goals for the OU1 site.


1999 Remedial Design Trench extraction system expansion 2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT





2000 Modification of the pumping system at Pond 10

The pumping system at Pond 10 was modified to drain the pond completely.

Final Remedial Action Report Pond 10 Pumping Facility Construction at OU 1

05 2000 Construction of trench extraction system expansion started

Extension of source area containment 2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT

06 2001 Construction of trench extraction system expansion completed

Four trenches installed with associated drains/sumps to capture contaminated groundwater from the Source Areas. Piezometers installed for monitoring. Water and LNAPL extraction pumps installed in sumps. Oil water separator constructed to remove LNAPL prior to pumping to IWTP. Landfill cap repair on LF4 and cap addition over CDPs.

2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT

06 2001 Operation of goundwater extraction system began

URS as O&M contractor and CH2M Hill as the long term monitoring contractor.

2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT

WP002 CHEMICAL PITS 1 AND 21995 Ethanol Flushing Treatabilty Study To assess innovative technology effectiveness for the OU 1

site remediation.Innovative Subsurface Remediation: Field Testing of Physical, Chemical, and Characterization Technologies. American Chemical Society Symposium Series 725





1996 Air Sparging/Soil Vapor Extraction Treatabilty Study

Contaminant removal rates by volatilization due to air sparging were higher than what could be achieved with a conventional pump and treat system. The addition of oxygen to the soils and groundwater appeared to enhance contaminant removal. The elevated carbon dioxide levels suggest that aerobic biodegradation was significant.

Innovative Subsurface Remediation: Field Testing of Physical, Chemical, and Characterization Technologies. American Chemical Society Symposium Series 725

1996 Treatability Study Steam Injection Treatability Study Hill AFB Environmental Restoration Management Action Plan - 2001

1996 Treatability Study Surfactant Middle Phase Microemulsion Treatability Study Hill AFB Environmental Restoration Management Action Plan - 2001

1996 Surfactant Solubilization Treatability Study

The mobilization mechanism was more effective than the solubilization mechanism in terms of contaminant removal for approximately the same amount of contaminant mass.

The results show that that there is significant potential for surfactant systems to expedite pump and treat remediation of residual oil and encourage the continued development and implementation of these systems.


1996 Complexing Sugar Flush Treatability Study

The technology was successful in enhancing remediation of the contaminated site. As an enhanced solubilization technology, it is not as aggressive as mobilization-based flushing technologies, but more efficient than water flushing.






1996 Treatability Study In-Well Aeration/Vertical Co-solvent Solubilization Treatability Study

Hill AFB Environmental Restoration Management Action Plan - 2001

1996 Single Phase Microemulsion Treatabilty Study

Both flushing methods (single phase microemulsion study and co-solvent mobilization study) removed approximately 90% of the mass based on soil cores and constituent removal in extraction wells and approximately 80% based on partitioning tracers.


1996 Co-solvent Mobilization Treatabilty Study

Both flushing methods (single phase microemulsion study and co-solvent mobilization study) removed approximately 90% of the mass based on soil cores and constituent removal in extraction wells and approximately 80% based on partitioning tracers.






FT009 FIRE TRAINING AREA 107 1989 No Further Remedial Action

PlannedDue to the lack of evidence of fire-training related contamination at FTA-1, coupled with the relative "sealing off" of surface water infiltration, it has been concluded that no further IRP action is necessary at FTA-1.

During the sampling in the referenced decision document, there was no evidence of soil contamination at FTA-1. It is possible that any contaminated materials were removed during interim construction activities at LF3 and LF4. It was also covered by the LF clay cap and asphalt during construction activities.

Groundwater contamination was found at MW-49 but is attributed to CDP1 and CDP2.

Final Decision Document for Fire Training Area 1, U.S. Air Force Installation Restoration Program, Hill Air Force Base, Utah, July 1989

OT014 GOLF COURSE05 1991 No Further Remedial Action

PlannedThere is no record of the golf course use as a disposal site. It was only investigated to determine the influence of irrigation on groundwater flow at the known disposal sites at OU 1 and OU 3. Effects of recharge from all sources will be addressed in the RI/FS reports for each operable unit.

Final Decision Document for Site OT14 - Golf Course, Hill Air Force Base, Utah

FT081 FIRE TRAINING AREA 204 1994 Bioventing Treatibilty Study Bioventing study reduced TPH-DRO concentrations to below

the Tier 1 Screening level of 5,000 mg/kg. The study lasted approximately one year.

Operable Unit 1 Fire Training Area 2 No Further Response Action Planned (NFRAP) Decision Document, IRP Site FT081, Leaking Underground Storage Tank Site EIIK, Hill Air Force Base, Utah





2001 No Further Remedial Action Planned

FT081 was recommended and accepted for NFRAP Operable Unit 1 Fire Training Area 2 No Further Response Action Planned (NFRAP) Decision Document, IRP Site FT081, Leaking Underground Storage Tank Site EIIK, Hill Air Force Base, Utah




XIII Five-Year Review of Sites in OU 1 Operable unit review results are summaries of findings for all of the sites in each operable unit. The following site summaries present a detailed review of each IRP site. Therefore, much of the information presented in the Site Summaries is a duplicate of what was presented in the OU Summary. The reader is encouraged to use the Site Summary to obtain details on specific contaminants of concern and the technical assessment for each site.

Site Summary - Hill AFB 2003 Five Year Review

OU 1 LF001 LANDFILL NO 4

II. Site Chronology See Table OU 1-2 for a history of events at this site. The table is organized to first describe events which impacted the whole OU, followed by events impacting only specific IRP sites within the OU.

III. Background Landfill 4 was a sanitary refuse landfill from 1967-1973 when it received solid wastes including scrap metal, construction debris, domestic refuse, industrial refuse, and small amounts of sludge from the IWTP drying beds, sulfuric acid, chromic acid, phenol, and methyl ethyl ketone. Landfill 4 is located southeast of Landfill 3 (LF003) and is bounded by Perimeter Road on the east and Range Road on the south (see Figures OU 1-1 and OU 1-2). Landfill 4 covers approximately 21 acres and is approximately 25 feet thick.

Contaminants of Concern

I. Introduction Landfill 4 (LF001) was a sanitary refuse landfill from 1967-1973. The landfill was capped with a low permeability soil cover in 1985 which was repaired in 2001 to prevent ponding and excess infiltration.

Media Contaminant(s) Cleanup Level Required

GW 1,1,1-TRICHLOROETHANE 200 ug/L

SOIL 1,1,1-TRICHLOROETHANE 10 mg/kg

SW 1,1,1-TRICHLOROETHANE 200 ug/L

GW 1,1-DICHLOROETHANE 790 ug/L

SOIL 1,1-DICHLOROETHANE 13 mg/kg

SW 1,1-DICHLOROETHANE 790 ug/L

GW 1,1-DICHLOROETHENE 7 ug/L

SOIL 1,1-DICHLOROETHENE 0.03 mg/kg

SW 1,1-DICHLOROETHENE 7 ug/L

GW 1,2,4-TRICHLOROBENZENE 70 ug/L

SOIL 1,2,4-TRICHLOROBENZENE 17 mg/kg

SW 1,2,4-TRICHLOROBENZENE 70 ug/L

GW 1,2-DICHLOROBENZENE 600 ug/L

SOIL 1,2-DICHLOROBENZENE 60 mg/kg

SW 1,2-DICHLOROBENZENE 600 ug/L

SOIL 1,2-DICHLOROETHANE 0.10 mg/kg

1 of 6September 2003 Final

CERCLA Five-Year Review Hill Air Force Base, Utah




SOIL 1,4-DICHLOROBENZENE 5.8 mg/kg


SOIL 2,3,7,8-TETRACHLORODIBENZOFURAN 0.004 mg/kg

GW 2,4-DIMETHYLPHENOL 600 ug/L

SOIL 2,4-DIMETHYLPHENOL 8 mg/kg

SW 2,4-DIMETHYLPHENOL 600 ug/L

GW 4-METHYLPHENOL (p-CRESOL) 750 ug/L

SOIL 4-METHYLPHENOL (p-CRESOL) 3.7 mg/kg

SW 4-METHYLPHENOL (p-CRESOL) 750 ug/L

GW ARSENIC 50 ug/L

SW ARSENIC 50 ug/L

GW BARIUM 1000 ug/L

SW BARIUM 1000 ug/L

GW BENZENE 5 ug/L

SOIL BENZENE 0.12 mg/kg

SW BENZENE 5 ug/L

SOIL BENZO(a)PYRENE 21 mg/kg

GW CHLOROBENZENE 100 ug/L

SOIL CHLOROBENZENE 2.4 mg/kg

SW CHLOROBENZENE 100 ug/L

GW cis-1,2-DICHLOROETHENE 70 ug/L

SOIL cis-1,2-DICHLOROETHENE 1.1 mg/kg

SW cis-1,2-DICHLOROETHENE 70 ug/L

SOIL ETHYLBENZENE 11 mg/kg

GW FLUORIDE 2400 ug/L





Remedial Action Objectives

SW FLUORIDE 2400 ug/L

GW NAPHTHALENE 1200 ug/L

SOIL NAPHTHALENE 22.5 mg/kg

SW NAPHTHALENE 1200 ug/L

SOIL PCB-1260 (AROCHLOR 1260) 10.1 mg/kg

SOIL PENTACHLOROPHENOL 0.26 mg/kg

GW TETRACHLOROETHENE(PCE) 5 ug/L

SOIL TETRACHLOROETHENE(PCE) 0.52 mg/kg

SW TETRACHLOROETHENE(PCE) 5 ug/L

GW TOLUENE 1000 ug/L

SOIL TOLUENE 43 mg/kg

SW TOLUENE 1000 ug/L

GW TRICHLOROETHENE (TCE) 5 ug/L

SOIL TRICHLOROETHENE (TCE) 0.17 mg/kg

SW TRICHLOROETHENE (TCE) 5 ug/L

GW VINYL CHLORIDE 2 ug/L

SOIL VINYL CHLORIDE 0.03 mg/kg

SW VINYL CHLORIDE 2 ug/L

GW XYLENES, TOTAL 10000 ug/L

SOIL XYLENES, TOTAL 1000 mg/kg

SW XYLENES, TOTAL 10000 ug/L

* The remedial action objectives for groundwater are to prevent human exposure through contact, ingestion, or inhalation to contaminated groundwater and restore groundwater to beneficial use. Institutional and engineering controls will prevent use of the water and contain contaminants in the Source Area. Contaminated groundwater from the Source Area will be treated as part of the dewatering process. Monitored natural attenuation is expected to meet these goals in the Non-Source Area.





IV. Remedial Actions

Source Area - Landfill CapThe remedial action at Landfill 4 consists of the low permeability soil cover constructed in 1985 and the repair of the areas of differential settlement in 2001. The purpose of the repair of the landfill cap was to minimize the infiltration of surface water into the landfill contents and the leaching of contamination into the groundwater. The remedial action also includes maintenance and monitoring of a gas vent system to prevent landfill gas concentrations from reaching dangerous levels.

Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitutional and engineering controls include restriction of access to landfill cap areas for unauthorized personnel using fencing and warning signs, enforcement of the Hill AFB Commander’s office continuing order that limits development within OU 1 (HAFB 1998), distribution of the Hill Restricted Use Access Map to the appropriate Hill AFB personnel to identify OU 1 as restricted to development, and restricting domestic usage of the shallow groundwater in the OU 1 area with drilling restriction per the Utah Division of Water Rights.

V. Progress Since Last Review

LF001 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review Report as a whole. Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.

VI. FYR Process Site review conducted per the process described in this report for the overall 2003 Five-Year Review.

Question A (Answer)

Yes

VII. Technical Assessment

* The remedial action objectives for the landfill contents and landfill gas are to: prevent human exposure to the contents and the gas; minimize infiltration, thus reducing additional groundwater contamination; and prevent landfill gas concentrations form reaching dangerous (i.e., explosive) levels.* The remedial action objective for surface water is to prevent human exposure through contact, ingestion, or inhalation to contaminated seep or spring water by the collection and treatment of the contaminated water.* The remedial action objectives for soils are to prevent human exposure through contact, ingestion, or inhalation to contaminated soil that presents an unacceptable risk and to prevent migration of contaminants that cause an unacceptable risk in groundwater.* The remedial action objectives for the LNAPL plume is [sic] to remove the LNAPL that can be practicably removed and to prevent contaminant migration from the Source Areas to groundwater at levels that impair water quality and/or represent a potential threat to human health and the environment.* The remedial action objectives for the Source Area are to prevent contaminants in excess of MCLs from migrating away from the Source Area so that the Non-Source Area can be effectively remediated and to restore Source Area groundwater to MCLs.





Question A (Comment)

Source Area - Landfill CapThe landfill cap remedial action has been successful in minimizing infiltration. Inspections by the on-site operators are ongoing and the cap is repaired as necessary. The cap at Landfill 4 will also be inspected via the Base wide landfill cap inspection process starting in calendar year (CY) 2003.

Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitution controls at Landfill 4 have been effective in preventing trespassing and unauthorized construction.

Question B (Answer)

No

Question B (Comment)

The arsenic cleanup level is currently valid. However, it should be noted that the revised arsenic standard of 10 ug/L (ppb) will be effective in 01/26/2006. Currently, analytical results for arsenic range from 1 ppb to 600 ppb. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene reference dose for oral ingestion [RfD(o)] decreased from 0.04 to 0.02 mg/kg/day, and the reference dose for inhalation [RfD(i)] is now available at 0.00090 mg/kg/day (EPA Region III 2002).

The RAOs associated with Landfill 4 are still valid.

The corrective action management unit rule was revised in 2002. The revised CAMU rule applies to the CAMU at OU 1 that includes Landfill No. 4 (see Figure 5-12 of the ROD [HAFB EMR 1998a]). The CAMU was designated for OU 1 based on the 1993 CAMU rule applicable at the time of the signing of the ROD in September 1998. Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C (Answer)

Yes

Question C (Comment)

Ponding on several areas at the landfills were identified during inspections as part of this review. This may compromise the integrity of the cap and allow excess infiltration.

VIII. Issues *Ponding on the landfill caps was noticeable during the inspection conducted as part of this review.

IX. Recommendations *Address drainage and ponding issues on Landfill 4 as soon as they are identified to ensure the landfill cap integrity.*Ensure that all gates and fences are locked in accordance with the ROD specified institutional controls.*Continue to perform landfill cap inspections.





XI. Next Required FYR

2008

X. Protectiveness Protective

Protectiveness Statement

The remedies associated with Landfill 4 (LF001) are protective of human health and the environment.




OU 1 WP002 CHEMICAL PITS 1 AND 2


III. Background CDP 1 covers approximately 2,600 square feet, with contamination extending from just below ground surface down to the water table. CDP 2 covers approximately 2,800 square feet extending from just below ground surface to the water table at about 25 feet bgs. Wastes disposed of at the CDPs included waste oil, fuel, IWTP flocculation wastes, and spent solvents including Stoddard solvent and paint thinner. The CDPs were covered with fill materials and portions were capped with a low permeability soil cover in the mid-1980s. The WP002 site also included the four above ground 20,000-25,000 gallons storage tanks known as the Waste Oil Storage Tanks (see Figures OU 1-1 and OU 1-2) that contained fuels, oils, and hydraulic fluids and were removed in 1981. Remedial actions regarding groundwater contamination resulting from the activities that historically took place at WP002 are currently being addressed through the OU 1-wide remedies.

Two additional IRP sites are addressed by the overall OU 1 remedies: the Waste Phenol Oil Pit (WP080) and the Fire Training Area 2 (FT081). All five IRP sites at OU 1 that have ongoing CERCLA actions were areas where industrial wastes, fuels, and other hazardous substances were dumped and/or burned. Subsequently, the shallow groundwater in the area and downgradient of the five sites was contaminated. Because of the proximity of the five sites, investigations, RAOs, and remedial actions have focused on them as a group. All of the sites except Fire Training Area 2 (FT081) and the Waste Phenol Oil Pit (WP080) were capped during construction activities at Landfill 3 and 4 and the groundwater contamination for the site and off-Base is being addressed through five remedial actions: extraction trenches that collect shallow groundwater and LNAPLs (source area), landfill cap (source area), remediation of contaminated surface water and soil at downgradient springs, monitored natural attenuation for contaminated groundwater off-Base, and institutional controls.


I. Introduction WP002 includes Chemical Disposal Pits (CDPs) 1 and 2 which were operated as industrial liquid waste disposal sites from 1952-1973. Groundwater contamination emanating from the CDPs is currently being addressed through the OU 1 remedial actions which include groundwater extraction trenches, spring remediation, monitored natural attenuation, and institutional controls. There are no remaining soils issues at CDPs 1 and 2 since the sites have been capped by Landfill 3.
































GW ARSENIC 50 ug/L

SW ARSENIC 50 ug/L

GW BARIUM 1000 ug/L

SW BARIUM 1000 ug/L





GW BENZENE 5 ug/L


SW BENZENE 5 ug/L





























Source Area - Groundwater Extraction TrenchesThe remedial action for groundwater in the source area includes five trenches to collect groundwater and LNAPL. The location and function of the four trenches that were installed in May 2001 and of the pre-existing trench that was installed in 1984 are described in the PSVP (CH2M 2001b). The extracted contaminated groundwater is passed through an oil water separator before being treated at the IWTP and is discharged to the North Davis Sewer Improvement District. The groundwater is treated in accordance with the existing pretreatment permits for these facilities (CH2M 2000).









* The remedial action objectives for the Source Area are to prevent contaminants in excess of MCLs from migrating away from the Source Area so that the Non-Source Area can be effectively remediated and to restore Source Area groundwater to MCLs.* The remedial action objectives for soils are to prevent human exposure through contact, ingestion, or inhalation to contaminated soil that presents an unacceptable risk and to prevent migration of contaminants that cause an unacceptable risk in groundwater.* The remedial action objectives for the LNAPL plume is [sic] to remove the LNAPL that can be practicably removed and to prevent contaminant migration from the Source Areas to groundwater at levels that impair water quality and/or represent a potential threat to human health and the environment.* Because arsenic is found above background values (11 mg/kg) at off-Base Springs U1-301, U1-303, U1-304, U1-305, and U1-318, HAFB is including the sediment at these springs in the areas for remediation. The remedial action objective for these sediments is to prevent human exposure through contact, ingestion, or inhalation to sediment that exceeds 11 mg/kg of arsenic.* The remedial action objective for surface water is to prevent human exposure through contact, ingestion, or inhalation to contaminated seep or spring water by the collection and treatment of the contaminated water.* The remedial action objectives for groundwater are to prevent human exposure through contact, ingestion, or inhalation to contaminated groundwater and restore groundwater to beneficial use. Institutional and engineering controls will prevent use of the water and contain contaminants in the Source Area. Contaminated groundwater from the Source Area will be treated as part of the dewatering process. Monitored natural attenuation is expected to meet these goals in the Non-Source Area.





Source Area - Landfill CapThe remedial action at Landfill 3 and 4 consists of minimizing the infiltration of surface water into the landfill contents and the leaching of contamination into the groundwater. The remedial action also includes maintenance and monitoring of a gas vent system to prevent landfill gas concentrations from reaching dangerous levels.

Non-Source Area - Spring Remediation SystemThe selected remedial action for the springs (U1-303, U1-304, U1-305, U1-307, and U1-318) is to treat the groundwater from springs with contamination levels above MCLs. Due to reducing conditions in the groundwater at OU 1, elevated arsenic concentrations in the groundwater have been measured. To mitigate arsenic from mobilizing from the sediment to the groundwater, sediments from spring areas with arsenic contamination above 11 mg/kg will be identified and excavated two to three years after the springs have ceased to flow.

Non-Source Area - Monitored Natural AttenuationThe selected remedial action for the non source area groundwater plumes is monitored natural attenuation. This remedial action requires long-term monitoring of the groundwater plumes to determine if naturally occurring attenuation processes are meeting the remedial action objectives as stated in the ROD.

Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitutional and engineering controls include restriction of access to landfill cap areas using fencing and warning signs, enforcement of the Hill AFB Commander’s office continuing order that limits development within OU 1 (HAFB 1998), distribution of the Hill Restricted Use Access Map to the appropriate Hill AFB personnel to identify OU 1 as an area restricted to development, and restricting domestic usage of the shallow groundwater in the OU 1 area with drilling restriction per the Utah Division of Water Rights.


WP002 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review Report as a whole. Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.


Question A (Answer)

Yes


The primary goal of the OU 1 remedies is to dewater the source area and prevent groundwater contamination of uncontaminated areas (non source areas). Since June 2001, the groundwater extraction system has extracted 28,216,379 gallons of groundwater and 6,301 gallons of LNAPL (as of 31 December 2002) (URS 2002a and 2002b).






*Source Area - Groundwater Extraction TrenchesWater elevations in the sumps at OU 1 must be maintained at levels below the trench pipe entry level to ensure that groundwater and LNAPL are captured by the trenches (CH2M 2002). As of December 2001, water levels have not been maintained in several sumps below the trench pipe entry elevation (U1-217, U1-218, U1-219, and U1-224). However, additional groundwater extraction pumps were installed in U1-217and U1-219 to increase extraction capacity. The groundwater gradient around the trenches was not evaluated as part of this review. Evaluation of the gradient would help determine if the trenches are containing the contaminated groundwater and LNAPL from migrating off-site.

*Non-Source Area - Spring Remediation SystemThe flows at springs U1-303 and U1-304 have decreased to a yearly average flow of less than 0.1 gpm, and springs U1-305 and U1-318 have ceased to flow. These springs have met the action levels that determine when the arsenic contaminated soils should be located and disposed. The groundwater extraction system is performing as designed by eliminating flow at these locations.

*Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitution controls at OU 1 have been effective in preventing trespassing and unauthorized construction.

Question B (Answer)

No


The arsenic cleanup level is currently valid. However it should be noted that a new, lower arsenic standard of 10 ug/L (ppb) will be effective 01/26/2006. Currently, analytical results for arsenic range from 1 ppb to 600 ppb. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/day, and the RfD(i) is now available at 0.00090 mg/kg/day (EPA Region III 2002).

When the remedial investigation was originally conducted, air sampling was performed in a number of homes above the plume. TCE was detected in several residences, but at levels that were not considered to be a risk at that time. Due to recent emphasis on vapor intrusion, EMR has worked with the EPA and UDEQ to establish an action level for TCE in indoor air at 0.43 ppbv. Because several of the indoor air sampling results from the original RI were above the new action level, there are potential air quality issues that have not been addressed.

The RAOs associated with Chemical Disposal Pits 1 and 2 are still valid.

The corrective action management unit rule was revised in 2002. The revised CAMU rule applies to the CAMU at OU 1 that includes Chemical Pits 1 and 2 (see Figure 5-12 of the ROD [HAFB EMR 1998a]). The CAMU was designated for OU 1 based on the 1993 CAMU





rule applicable at the time of the signing of the ROD in September 1998. Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C (Answer)

Yes


*Source Area - Groundwater Extraction TrenchesAlthough the system has extracted large amounts of contaminated groundwater and LNAPLs, it is not clear at this time that the system is preventing the migration of groundwater from the source area to the non-source area. The conclusions of the OU 1 Source Area Zone Delineation Progress Report (Intera 2002) indicate that hydrocarbon concentrations are measurable downgradient and to the west of the exterior trench (Trench D) (see Figure OU 1-1 for location). This could be an indication that contaminated groundwater from the source area is not being captured by either the interior or exterior trenches or that there is an additional source of contamination.

During site inspections performed as part of this review, maintenance of some systems at the site was noted to be lacking. Specifically, replacement of the carbon unit on Oil/Water Separator off-gas, LNAPL disposal, and Oil/Water Separator cleanings should be performed on a regular basis.

A preliminary trend analysis of four monitoring locations indicate the following (the locations of the monitoring locations can be found in the OU 1 PSVP [CH2M 2001b]): *The Method Detection Limits for all four of the contaminants reviewed (TCE, DCE11, DCE12T, and DCE12C) were too high to detect some of the analytes at several of the locations at their current concentrations.*DCE12C (PRG = 70 ppb) concentrations at U1-067 decreased from approximately 8,600 ppb to 5,510 ppb over a five year period. *DCE12T (MCL = 100 ppb) concentrations at U1-162 have decreased from approximately 70 ppb to 5 ppb over a five year period. *The DCE12C concentrations at U1-667 decreased from approximately 4,300 ppb to 3,300 ppb over the past five years (still above the PRG of 70 ppb). The TCE (MCL = 5ppb) concentrations have decreased from 700 ppb to 240 ppb over a five year period. However, the DCE11 (PRG = 7 ppb) concentrations have increased from approximately 9 to 14 ppb. *At U1-079 all of the analytes reviewed increased over a five year period. TCE increased from approximately 5 to 25 ppb, DCE12T increased from approximately 1 to 6 ppb, and DCE 12C increased from approximately 60 to 350 ppb.

From this preliminary review, it is not possible to conclude that there is a significant downward or upward trend in concentrations of contaminants of concern at OU 1. Further, the impact of the trenches (which have operated for only 1.5 years) is not evident because of this short duration of remedial actions at OU 1.

*Source Area - Landfill Cap





Ponding on several areas at the landfills have been identified during CY 2002. This may compromise the integrity of the cap and allow excess infiltration.

*Non-Source Area - Spring Remediation SystemIn the OU 1 Feasibility Study Report (CH2M 1998) and Comprehensive Remedial Investigation Report (MW 1995), several exposure pathways are listed for current and future use. Of these pathways, springs and seeps are the most problematic for current and future use of groundwater and surface water on Base and off Base.

Analytical results for benzene, cis-1,2 DCE, trans-1,2 DCE, PCE, TCE, vinyl chloride, and chromium at the 19 springs/seeps at OU 1 were reviewed over time. Of the 19 locations, intermittent analytical results from nine locations (U1-303, U1-304, U1-305, U1-306, U1-312, U1-313, U1-314, U1-317, and U1-318) were available in ERPIMS. These nine locations have been dry for the past several rounds of sampling. Springs U1-311 and U1-319 are not currently monitored. The only spring that currently exhibits groundwater contamination above PRGs is U1-307 (exceeds the PRG for cis-1,2 DCE). However, the water from this spring is collected via the groundwater extraction system at OU 1 and is discharged to the IWTP for treatment.

There are no analytical results for chromium in ERPIMS after 1995. A future potential exposure pathway has been identified as chromium in springs used for watering livestock (MW 1995 and CH2M 1998); therefore, chromium needs to be added to the sampling and analysis plan (SAP) at OU 1 again. All of the results in ERPIMS for total chromium were non detect except for U1-301 (15ug/g on 4/16/1990), U1-302 (18 ug/g on 4/16/1990), and U1-305 (15 ug/g on 4/17/1990). The MCL for total chromium is 100 ug/L.

VIII. Issues *Eighteen months of operational data are not sufficient to determine if the remedies at OU 1 are containing contaminated groundwater. As discussed in the PSVP (CH2M 2001b), five years of data with at least two sampling rounds per year should provide adequate samples across the site and over time to determine if plume mean concentrations are decreasing. However, if there are measurable hydrocarbon concentrations in samples collected downgradient and to the west of the exterior trench (Trench D), monitored natural attenuation in that portion of the non-source area may not be adequate to remediate the contaminated groundwater.

*A preliminary check between the PSVP sampling requirements and data in ERPIMS showed that the analytical results from several locations were not available. This may be due to the lag time between sampling activities and the uploading of the results into ERPIMS, the possibility that the sampling locations were/are dry, or that the locations were not sampled.

*Some of the indoor air sampling results, collected during the RI, exceed the new action level for TCE in indoor air (0.43 ppbv).

IX. Recommendations *Re-evaluate the non-source area monitored natural attenuation remedial action to determine if it is still applicable in all non-source areas (specifically in the area of






2008

measurable hydrocarbon concentrations outside Trench D).*Modify ERPIMS to indicate springs and seeps that are dry during a sampling event.*Review the long term monitoring sampling and analysis plan to ensure that locations where the hydrocarbon concentrations were located during the Source Zone Area Delineation project (Intera 2001) are monitored.*Proceed with the delineation and excavation of the arsenic contaminated soils at the springs.*Determine if the trenches are containing/capturing the contamination in the source area by evaluating the gradient around the trenches. Additional monitoring points may be necessary to confirm that the prescribed water levels in the sumps are adequate to maintain containment.*Reevaluate the RI data on indoor air and determine if the new action level for TCE (0.43 ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.*Reevaluate the risk analysis for OU 1 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors, as explained in the Technical Assessment above. *Ensure that all gates and fences are locked in accordance with the ROD-specified institutional controls.*Implement maintenance activities in a timely manner.*Determine if the plume mean concentrations are decreasing, using the described locations and monitoring frequency outlined in the PSVP and the results of the PSVR, scheduled for 2006.*Ensure that the method detection limits (MDL) are low enough to detect a contaminant of concern (i.e., MDL equal to or less than the MCL or PRG).*Add chromium to the sampling and analysis plan for springs at OU 1.*Collect samples from all locations described in the PSVP.

X. Protectiveness Protectiveness cannot be determined until further information is obtained


A protectiveness determination of the remedies associated with WP002 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 1. Therefore, a re-evaluation of potential risk at OU 1 must be conducted before the protectiveness of the current remedies can be determined.

Additional items that need to be addressed are described in the previous issues and recommendations and include: the appropriateness of the monitored natural attenuation remedial action in the area of measurable hydrocarbon concentrations outside Trench D, and determining if the trenches are containing/capturing the contamination in the source area. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 1 during the next Five-Year Review (2008).






III. Background Landfill 3 covers approximately 14 acres and is up to 25 feet thick (see Figures OU 1-1 and OU 1-2). During operations at Landfill 3, garbage trucks were backed up and liquid and solid refuse was dumped and burned on a daily basis. The IWTP disposed sludge into Landfill 3 containing heavy metals from 1956-1967. Other materials known to have been disposed of in Landfill 3 are sanitary and industrial refuse, construction debris, IWTP sludge drying bed and flocculation wastes, paint sludges, paint booth scrubber sludge, plastics, spent sandblast media, spent solvents, residues from spent solvent cleaning operations, and residues and filters from plating and cleaning operations.


I. Introduction Landfill 3 (LF003) was an industrial dump and burn pit and liquid and solid waste disposal site that was in operation from 1940-1967. Landfill 3 was capped in two stages with a low permeability soil cover in 1985 and again in 1986 to reduce surface water infiltration.
































GW ARSENIC 50 ug/L

SW ARSENIC 50 ug/L

GW BARIUM 1000 ug/L

SW BARIUM 1000 ug/L

GW BENZENE 5 ug/L


SW BENZENE 5 ug/L




































* The remedial action objectives for groundwater are to prevent human exposure through contact, ingestion, or inhalation to contaminated groundwater and restore groundwater to beneficial use. Institutional and engineering controls will prevent use of the water and contain contaminants in the Source Area. Contaminated groundwater from the Source Area will be treated as part of the dewatering process. Monitored natural attenuation is expected to meet these goals in the Non-Source Area.






Source Area - Landfill CapThe remedial action at Landfill 3 included construction of a new portion of low-permeability cap over the CDP area and the repair of portions of the cap (installed in 1985) disturbed by the installation of the groundwater extraction trenches. The purpose of the repair of the landfill cap was to minimize the infiltration of surface water into the landfill contents and the possible leaching of contamination into the groundwater. The remedial action also includes maintenance and monitoring of a gas vent system to prevent landfill gas concentrations from reaching dangerous levels.

Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitutional and engineering controls include restriction of access to landfill cap areas for unauthorized personnel using fencing and warning signs, enforcement of the Hill AFB Commander’s office continuing order that limits development within OU 1 (HAFB 1998), distribution of the Hill Restricted Use Access Map to the appropriate Hill AFB personnel to identify OU 1 as restricted to development, and restricting domestic usage of the shallow groundwater in the OU 1 area with drilling restrictions per the Utah Division of Water Rights.


LF003 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review Report as a whole. Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.



* The remedial action objective for surface water is to prevent human exposure through contact, ingestion, or inhalation to contaminated seep or spring water by the collection and treatment of the contaminated water.* The remedial action objectives for soils are to prevent human exposure through contact, ingestion, or inhalation to contaminated soil that presents an unacceptable risk and to prevent migration of contaminants that cause an unacceptable risk in groundwater.* The remedial action objectives for the LNAPL plume is [sic] to remove the LNAPL that can be practicably removed and to prevent contaminant migration from the Source Areas to groundwater at levels that impair water quality and/or represent a potential threat to human health and the environment.* The remedial action objectives for the landfill contents and landfill gas are to: prevent human exposure to the contents and the gas; minimize infiltration, thus reducing additional groundwater contamination; and prevent landfill gas concentrations form reaching dangerous (i.e., explosive) levels.* The remedial action objectives for the Source Area are to prevent contaminants in excess of MCLs from migrating away from the Source Area so that the Non-Source Area can be effectively remediated and to restore Source Area groundwater to MCLs.





Question A (Answer)

Yes


Source Area - Landfill CapThe landfill cap remedial action has been successful in minimizing infiltration. Inspections by the on-site operators are ongoing and repaired as necessary. The cap at Landfill 3 will also be inspected via the Base wide landfill cap inspection process starting in calendar year (CY) 2003.

Common to Both Source Area and Non-Source Area - Institutional Engineering ControlsInstitution controls at Landfill 3 have been effective in preventing trespassing and unauthorized construction.

Question B (Answer)

No

Question B (Comment) The arsenic cleanup level is currently valid. However it should be noted that the revised

arsenic standard of 10 ug/L (ppb) will be effective in 01/26/2006. Currently, analytical results for arsenic range from 1 ppb to 600 ppb. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/day, and the RfD(i) is now available at 0.00090 mg/kg/day (EPA Region III 2002).

The RAOs associated with Landfill 3 are still valid.

The corrective action management unit rule was revised in 2002. The revised CAMU rule applies to the CAMU at OU 1 that includes Landfill No. 3 (see Figure 5-12 of the ROD [HAFB EMR 1998a]). The CAMU was designated for OU 1 based on the 1993 CAMU rule applicable at the time of the signing of the ROD in September 1998. Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C (Answer)

Yes


Ponding on several areas at the landfills were identified during inspections as part of this review. This may compromise the integrity of the cap and allow excess infiltration.

VIII. Issues *Ponding on the landfill caps was noticeable during the inspection conducted as part of this review.

IX. Recommendations *Address drainage and ponding issues on Landfill 3 as soon as they are identified to ensure the landfill cap integrity.






2008

*Ensure that all gates and fences are locked in accordance with the ROD specified institutional controls.*Continue to perform landfill cap inspections.



The remedies associated with Landfill 3 (LF003) are protective of human health and the environment.




OU 1 FT009 FIRE TRAINING AREA 1


III. Background Fire Training Area 1 (FTA-1) covers approximately one-third of an acre and is located within the Operable Unit 1 area in Landfill 3 (see Figure OU 1-1). This site was identified for IRP investigation during the Phase II Stage 2 Presurvey meeting in March 1985 where Base records and soil boring and monitoring well analytical results were reviewed. Due to the lack of evidence of shallow soil contamination at the site, and that if there had been any contamination it was removed during interim construction activities at Landfills 3 and 4 and capped, FTA-1 was recommended for NFRAP status and accepted in 1989 (SAIC 1989) due to the fact that surface water infiltration was mitigated by the Landfill 3 cap.


Not applicable.


FT009 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review report as a whole. Since the review in 1998, the ROD has been written and the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.


Question A (Answer)

Not Applicable



I. Introduction Fire Training Area 1 (FT009) was used by Hill AFB to extinguish simulated aircraft fires from 1958-1973. Large quantities of oil and combustible waste chemicals were poured into a dirt pit surrounded by an earthen dike and then ignited. However, Fire Training Area 1 was recommended for NFRAP status and accepted in July of 1989 when soil borings showed no evidence of shallow soil contamination and Base records indicated that Fire Training Area 1 was also covered by the Landfill 3 clay and asphalt cap during construction activities. This site is included in the 2003 Five-Year Review Report for completeness to document the site's history.



NA NA - Risk Assessment indicates no risk to human health and the environment.

NA

* Not applicable. No COCs or RAOs for this site.






None - Current FYR is Final


Not applicable.

Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues Not applicable.

IX. Recommendations Not applicable.

X. Protectiveness Not Applicable


FT009 was recommended for NFRAP status and accepted in 1989 because there was no evidence of shallow soil contamination and the area was covered by the Landfill 3 low permeability soil cap.




OU 1 OT014 GOLF COURSE


III. Background The Golf Course (OT014) was recommended for NFRAP status and accepted in 1991 because there was no history of hazardous wastes ever having been disposed at the site. The effect of recharge by irrigation and the impact to groundwater under Landfills 3 and 4 were evaluated and it was estimated that approximately 12.5 inches per year of percolation could occur and flow to OU 1; however, with the construction of the slurry wall between the golf course and OU 1 in 1985, percolation was thought to have been mitigated (Heyes, C. 1991). This site is not included in the ROD for OU 1 (HAFB EMR 1998a); therefore, there are no RAOs associated with this site.


Not applicable.


OT014 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review report as a whole. Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.


Question A (Answer)

Not Applicable


Not applicable.



I. Introduction OT014 was developed in 1960 as the Base golf course located south of Landfill 4 and along the eastern boundary of Hill AFB (see Figure OU 1-1). OT014 was recommended for NFRAP status and accepted in 1991 because there was no history of hazardous wastes ever being disposed at the site (Heyse, C. 1991). This site is included in the 2003 Five-Year Review Report for completeness to document the site's history.



NA NA - No history of contamination at this site. NA





OU 1 OT014 GOLF COURSE



Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.





OT014 was recommended for NFRAP status and accepted in 1991 because there was no history of hazardous wastes ever having been disposed of at the site.






III. Background Fire Training Area 2 is located along Perimeter Road in the northern portion of Operable Unit 1 and covers approximately 2.5 acres (see Figures OU 1-1 and OU1-2). Mixed and on-specification jet fuel were stored in and dispensed from a 5,000 gallon UST which was removed in October of 1993 in accordance with UDEQ Division of Environmental Response and Remediation (DERR) (CH2M 2001a). After the UST was removed, soil contamination was found near the former UST. A Bioventing Treatability Study, from April 1994 to July 1995, reduced TPH-DRO concentrations ranging from 1,500 mg/kg to 22,000 mg/kg to below the Tier 1 Screening level of 5,000 mg/kg. No further remedial action regarding soils was recommended and accepted in 2001 (CH2M 2001a) following the study. Currently, a fire training tower is still in use at the site, where wood is used as fuel. FTA-2 is currently covered by an asphalt cap, there are no utilities or property boundaries within 30 feet of the former fuel area, and the closest occupied building is more than 2,000 feet from the site. Remedial actions regarding groundwater contamination resulting from the activities that historically took place at FT081 and other OU 1 sites are currently being addressed through the OU 1-wide remedies.

Two additional IRP sites are addressed by the overall OU 1 remedies: the Waste Phenol Oil Pit (WP080) and the Chemical Disposal Pits (WP002). All five IRP sites at OU 1 that have ongoing CERCLA actions were areas where industrial wastes, fuels, and other hazardous substances were dumped and/or burned. Subsequently, the shallow groundwater in the area and downgradient of the five sites was contaminated. Because of the proximity of the five sites, investigations, RAOs, and remedial actions have focused on them as a group. All of the sites except Fire Training Area 2 (FT081) and the Waste Phenol Oil Pit (WP080) were capped during construction activities at Landfill 3 and 4 and the groundwater contamination for the site and off-Base is being addressed through five remedial actions: extraction trenches that collect shallow groundwater and LNAPLs (source area), landfill cap (source area), remediation of contaminated surface water and soil at downgradient springs, monitored natural attenuation for contaminated groundwater off-Base, and institutional controls.

I. Introduction Fire Training Area 2 (FTA-2) was used by Hill AFB to extinguish simulated aircraft fires from 1973-1995 where jet fuel, propane, and explosives were used as fuel. Soil contamination of TPH-DRO (Total Petroleum Hydrocarbons - Diesel Range Organics) was remediated with a Bioventing Treatability Study conducted from April 1994 to July 1995, when it was recommended for no further remedial action status regarding soil contamination at the FTA-2 site. This recommendation was accepted in 2001 (CH2M 2001a). Groundwater contamination from the Fire Training Area 2 site is currently being addressed through the OU 1-wide remedial actions which include groundwater extraction trenches, spring remediation, monitored natural attenuation, and institutional controls.























GW ARSENIC 50 ug/L

SW ARSENIC 50 ug/L

GW BARIUM 1000 ug/L

SW BARIUM 1000 ug/L

GW BENZENE 5 ug/L

SW BENZENE 5 ug/L
























* The remedial action objectives for the LNAPL plume is [sic] to remove the LNAPL that can be practicably removed and to prevent contaminant migration from the Source Areas to groundwater at levels that impair water quality and/or represent a potential threat to human health and the environment.* Because arsenic is found above background values (11 mg/kg) at off-Base Springs U1-301, U1-303, U1-304, U1-305, and U1-318, HAFB is including the sediment at these springs in the areas for remediation. The remedial action objective for these sediments is to prevent human exposure through contact, ingestion, or inhalation to sediment that exceeds 11 mg/kg of arsenic.* The remedial action objectives for the Source Area are to prevent contaminants in excess of MCLs from migrating away from the Source Area so that the Non-Source Area can be effectively remediated and to restore Source Area groundwater to MCLs.* The remedial action objectives for groundwater are to prevent human exposure through contact, ingestion, or inhalation to contaminated groundwater and restore groundwater to beneficial use. Institutional and engineering controls will prevent use of the water and contain contaminants in the Source Area. Contaminated groundwater from the Source Area will be treated as part of the dewatering process. Monitored natural attenuation is expected to meet these goals in the Non-Source Area.







Non-Source Area - Spring Remediation SystemThe selected remedial action for the springs (U1-303, U1-304, U1-305, U1-307, and U1-318) is to treat the groundwater from springs with contamination levels above MCLs. Due to reducing conditions in the groundwater at OU 1, elevated arsenic concentrations in the groundwater have been measured. To mitigate arsenic from mobilizing from the sediment to the groundwater, sediments from spring areas with arsenic contamination above 11 mg/kg will be identified and excavated two to three years after the springs have ceased to flow.




FT081 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review Report as a whole. Since the review in 1998, the ROD has been written and all of the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.


* The remedial action objective for surface water is to prevent human exposure through contact, ingestion, or inhalation to contaminated seep or spring water by the collection and treatment of the contaminated water.* The remedial action objectives for soils are to prevent human exposure through contact, ingestion, or inhalation to contaminated soil that presents an unacceptable risk and to prevent migration of contaminants that cause an unacceptable risk in groundwater.





Question A (Answer)

Yes



*Source Area - Groundwater Extraction TrenchesWater elevations in the sumps at OU 1 must be maintained at levels below the trench pipe entry level to ensure that groundwater and LNAPL are captured by the trenches (CH2M 2002). As of December 2001, water levels have not been maintained in several sumps below the trench pipe entry elevation (U1-217, U1-218, U1-219, and U1-224). However, additional groundwater extraction pumps were installed in U1-217 and U1-219 to increase extraction capacity. The groundwater gradient around the trenches was not evaluated as part of this review. Evaluation of the gradient would help determine if the trenches are containing the contaminated groundwater and LNAPL from migrating off-site.

*Non-Source Area - Spring Remediation SystemThe flows at springs U1-303 and U1-304 have decreased to a yearly average flow of less than 0.1 gpm, and springs U1-305 and U1-318 have ceased to flow. These springs have met the action levels that determine when the arsenic contaminated soils should be located and disposed. The groundwater extraction system is performing as designed by eliminating flow at these locations.


Question B (Answer)

No

Question B (Comment) The arsenic cleanup level is currently valid. However it should be noted that a new, lower

arsenic standard of 10 ug/L (ppb) will be effective 01/26/2006. Currently, analytical results for arsenic range from 1 ppb to 600 ppb. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/day, and the RfD(i) is now available at 0.00090 mg/kg/day (EPA Region III 2002).

When the remedial investigation was originally conducted, air sampling was performed in a number of homes above the plume. TCE was detected in several residences, but at levels that were not considered to be a risk at that time. Due to recent emphasis on vapor intrusion, EMR has worked with the EPA and UDEQ to establish an action level for TCE in indoor air at 0.43 ppbv. Because several of the indoor air sampling results from the original






RI were above the new action level, there are potential air quality issues that have not been addressed.

The RAOs associated with Fire Training Area 2 are still valid.

The corrective action management unit rule was revised in 2002. The revised CAMU rule applies to the CAMU at OU 1 that includes Fire Training Area 2 (see Figure 5-12 of the ROD [HAFB EMR 1998a]). The CAMU was designated for OU 1 based on the 1993 CAMU rule applicable at the time of the signing of the ROD in September 1998. Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C (Answer)

Yes


*Source Area - Groundwater Extraction TrenchesAlthough the system has extracted large amounts of contaminated groundwater and LNAPLs, it is not clear at this time that the system is preventing the migration of groundwater from the source area to the non-source area. The conclusions of the OU 1 Source Area Zone Delineation Progress Report (Intera 2002) indicate that hydrocarbon concentrations are measurable downgradient and to the west of the exterior trench (Trench D) (see Figure OU 1-1 for location). This could be an indication that contaminated groundwater from the source area is not being captured by either the interior or exterior trenches or that there is an additional source of contamination.


A preliminary trend analysis of four monitoring locations indicate the following (the locations of the monitoring locations can be found in the OU 1 PSVP [CH2M 2001]): *The Method Detection Limits for all four of the contaminants reviewed (TCE, DCE11, DCE12T, and DCE12C) were too high to detect some of the analytes at several of the locations at their current concentrations.*DCE12C (PRG = 70 ppb) concentrations at U1-067 decreased from approximately 8,600 ppb to 5,510 ppb over a five year period. *DCE12T (MCL = 100 ppb) concentrations at U1-162 have decreased from approximately 70 ppb to 5 ppb over a five year period. *The DCE12C concentrations at U1-667 decreased from approximately 4,300 ppb to 3,300 ppb over the past five years (still above the PRG of 70 ppb). The TCE (MCL = 5ppb) concentrations have decreased from 700 ppb to 240 ppb over a five year period. However, the DCE11 (PRG = 7 ppb) concentrations have increased from approximately 9 to 14 ppb. *At U1-079 all of the analytes reviewed increased over a five year period. TCE increased from approximately 5 to 25 ppb, DCE12T increased from approximately 1 to 6 ppb, and DCE





12C increased from approximately 60 to 350 ppb.


*Source Area - Landfill CapPonding on several areas at the landfills have been identified during CY 2002. This may compromise the integrity of the cap and allow excess infiltration.

*Non-Source Area - Spring Remediation SystemIn the OU 1 Feasibility Study Report (CH2M 1998) and Comprehensive Remedial Investigation Report (MW 1995), several exposure pathways are listed for current and future use. Of these pathways, springs and seeps are the most problematic for current and future use of groundwater and surface water on Base and off Base.

Analytical results for benzene, cis-1,2 DCE, trans-1,2 DCE, PCE, TCE, vinyl chloride, and chromium at the 19 springs/seeps at OU 1 were reviewed over time. Of the 19 locations, intermittent analytical results from nine locations (U1-303, U1-304, U1-305, U1-306, U1-312, U1-313, U1-314, U1-317, and U1-318) were available in ERPIMS. These nine locations have been dry for the past several rounds of sampling. Springs U1-311 and U1-319 are not currently monitored. The only spring that currently exhibits groundwater contamination above PRGs is U1-307 (exceeds the PRG for cis-1,2 DCE). However, the water from this spring is collected via the groundwater extraction system at OU 1 and is discharged to the IWTP for treatment.



*A preliminary check between the PSVP sampling requirements and data in ERPIMS showed that the analytical results from several locations were not available. This may be due to the lag time between sampling activities and the uploading of the results into ERPIMS, the possibility that the sampling locations were/are dry, or that the locations were





not sampled.


IX. Recommendations *Re-evaluate the non-source area monitored natural attenuation remedial action to determine if it is still applicable in all non-source areas (specifically in the area of measurable hydrocarbon concentrations outside Trench D).*Modify ERPIMS to include a field for springs and seeps that exhibit dry conditions during a sampling event.*Review the long term monitoring sampling and analysis plan to ensure that locations where the hydrocarbon concentrations were located during the Source Zone Area Delineation project (Intera 2001) are monitored.*Proceed with the delineation and excavation of the arsenic contaminated soils at the springs.*Determine if the trenches are containing/capturing the contamination in the source area by evaluating the gradient around the trenches. Additional monitoring points may be necessary to confirm that the prescribed water levels in the sumps are adequate to maintain containment.*Re-evaluate the risk analysis for OU 1 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors, as explained in the Technical Assessment above. *Re-evaluate the Remedial Investigation data on indoor air and determine if the new action level for TCE (0.43 ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.*Ensure that all gates and fences are locked in accordance with the ROD specified institutional controls.*Implement maintenance activities in a timely manner.*Determine if the plume mean concentrations are decreasing, using the described locations and monitoring frequency outlined in the Performance Standard Verification Plan and the results of the Performance Standard Verification Report, scheduled for 2006.*Ensure that the method detection limits (MDL) are low enough to detect a contaminant of concern (i.e., MDL equal to or less than the MCL or PRG).*Add chromium to the sampling and analysis plan for spring at OU 1.*Collect samples from all locations described in the PSVP.



A protectiveness determination of the remedies associated with FT081 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 1. Therefore, a re-evaluation of potential risk at OU 1 must be conducted before the protectiveness of the current remedies can be determined.

Additional items that need to be addressed are described in the previous issues and recommendations and include: the appropriateness of the monitored natural attenuation






2008

remedial action in the area of measurable hydrocarbon concentrations outside Trench D, and determining if the trenches are containing/capturing the contamination in the source area. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 1 during the next Five-Year Review (2008).




OU 1 WP080 WASTE OIL PHENOL PIT


III. Background The WPOP was constructed in 1954 for the burning of waste oil and phenols generated during industrial processes (see Figure OU 1-1 for location). During its first use, the brick burn pit broke apart due to high combustion temperatures, but the pit was used on a weekly basis until 1965. When the pit was excavated in 1965, the visibly stained soils were disposed of in Landfill 3. Remedial actions regarding groundwater contamination resulting from the activities that historically took place at WP080 are currently being addressed through the OU 1-wide remedies.

Two additional IRP sites are addressed by the overall OU 1 remedies: the Chemical Disposal Pits (WP002) and the Fire Training Area 2 (FT081). All five IRP sites at OU 1 that have ongoing CERCLA actions were areas where industrial wastes, fuels, and other hazardous substances were dumped and/or burned. Subsequently, the shallow groundwater in the area and downgradient of the five sites was contaminated. Because of the proximity of the five sites, investigations, RAOs, and remedial actions have focused on them as a group. All of the sites except Fire Training Area 2 (FT081) and the Waste Phenol Oil Pit (WP080) were capped during construction activities at Landfill 3 and 4 and the groundwater contamination for the site and off-Base is being addressed through five remedial actions: extraction trenches that collect shallow groundwater and LNAPLs (source area), landfill cap (source area), remediation of contaminated surface water and soil at downgradient springs, monitored natural attenuation for contaminated groundwater off-Base, and institutional controls.


I. Introduction WP080, the Waste Phenol Oil Pit (WPOP), was a brick-lined pit used to dispose and burn waste oil and phenol from 1954 to 1965. The WPOP was located in the northeast area of OU 1 where surface water retention Pond 10 is now located. Groundwater contamination emanating from the WPOP is currently being addressed through the OU 1 remedial actions which include groundwater extraction trenches and institutional controls.
































GW ARSENIC 50 ug/L

SW ARSENIC 50 ug/L

GW BARIUM 1000 ug/L

SW BARIUM 1000 ug/L

GW BENZENE 5 ug/L


SW BENZENE 5 ug/L







Non-Source Area - Spring Remediation SystemThe selected remedial action for the springs (U1-303, U1-304, U1-305, U1-307, and U1-318) is to treat the groundwater from springs with contamination levels above MCLs. Due to reducing conditions in the groundwater at OU 1, elevated arsenic concentrations in the groundwater have been measured. To mitigate arsenic from mobilizing from the sediment to






* The remedial action objectives for soils are to prevent human exposure through contact, ingestion, or inhalation to contaminated soil that presents an unacceptable risk and to prevent migration of contaminants that cause an unacceptable risk in groundwater.* The remedial action objectives for the LNAPL plume is [sic] to remove the LNAPL that can be practicably removed and to prevent contaminant migration from the Source Areas to groundwater at levels that impair water quality and/or represent a potential threat to human health and the environment.* The remedial action objective for surface water is to prevent human exposure through contact, ingestion, or inhalation to contaminated seep or spring water by the collection and treatment of the contaminated water.* Because arsenic is found above background values (11 mg/kg) at off-Base Springs U1-301, U1-303, U1-304, U1-305, and U1-318, HAFB is including the sediment at these springs in the areas for remediation. The remedial action objective for these sediments is to prevent human exposure through contact, ingestion, or inhalation to sediment that exceeds 11 mg/kg of arsenic.* The remedial action objectives for groundwater are to prevent human exposure through contact, ingestion, or inhalation to contaminated groundwater and restore groundwater to beneficial use. Institutional and engineering controls will prevent use of the water and contain contaminants in the Source Area. Contaminated groundwater from the Source Area will be treated as part of the dewatering process. Monitored natural attenuation is expected to meet these goals in the Non-Source Area.* The remedial action objectives for the Source Area are to prevent contaminants in excess of MCLs from migrating away from the Source Area so that the Non-Source Area can be effectively remediated and to restore Source Area groundwater to MCLs.





the groundwater, sediments from spring areas with arsenic contamination above 11 mg/kg will be identified and excavated two to three years after the springs have ceased to flow.




WP080 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b). However, interim remedies that had been installed for OU 1 were reviewed in the 1998 Five-Year Review Report as a whole. Since the review in 1998, the ROD has been written and the remedial actions outlined in the ROD have been implemented except for removal of arsenic contaminated soils from the springs.


Question A (Answer)

Yes



*Source Area - Groundwater Extraction TrenchesWater elevations in the sumps at OU 1 must be maintained at levels below the trench pipe entry level to ensure that groundwater and LNAPL are captured by the trenches (CH2M 2002). As of December 2001, water levels have not been maintained in several sumps below the trench pipe entry elevation (U1-217, U1-218, U1-219, and U1-224). However, additional groundwater extraction pumps were installed in U1-217 and U1-219 to increase its extraction capacity. The groundwater gradient around the trenches was not evaluated as part of this review. Evaluation of the gradient would help determine if the trenches are containing the contaminated groundwater and LNAPL from migrating off-site.

*Non-Source Area - Spring Remediation System






The flows at springs U1-303 and U1-304 have decreased to a yearly average flow of less than 0.1 gpm, and springs U1-305 and U1-318 have ceased to flow. These springs have met the action levels that determine when the arsenic contaminated soils should be located and disposed. The groundwater extraction system is performing as designed by eliminating flow at these locations.


Question B (Answer)

No

Question B (Comment) The arsenic cleanup level is currently valid. However it should be noted that a new, lower

arsenic standard of 10 ug/L (ppb) will be effective 01/26/2006. Currently, analytical results for arsenic range from 1 ppb to 600 ppb. The barium cleanup level of 1000 ug/L is lower than the MCL of 2000 ug/L (overprotective). The fluoride cleanup level of 2400 ug/L is lower than the MCL of 4000 ug/L (overprotective). The naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/day, and the RfD(i) is now available at 0.00090 mg/kg/day (EPA Region III 2002).

When the remedial investigation was originally conducted, air sampling was performed in a number of homes above the plume. TCE was detected in several residences, but at levels that were not considered to be a risk at that time. Due to recent emphasis on vapor intrusion, EMR has worked with the EPA and UDEQ to establish an action level for TCE in indoor air at 0.43 ppbv. Because several of the indoor air sampling results from the original RI were above the new action level, there are potential air quality issues that have not been addressed.

The RAOs associated with the Waste Phenol Oil Pit are still valid.

The corrective action management unit rule was revised in 2002. The revised CAMU rule applies to the CAMU at OU 1 that includes the Waste Oil Phenol Pit (see Figure 5-12 of the ROD [HAFB EMR 1998a]). The CAMU was designated for OU 1 based on the 1993 CAMU rule applicable at the time of the signing of the ROD in September 1998. Because no changes to the scope of the CAMU have been made at OU 1, the action of creating a CAMU for the purposes specified in the OU 1 ROD is in compliance with the revised CAMU rule.

Question C (Answer)

Yes


*Source Area - Groundwater Extraction TrenchesAlthough the system has extracted large amounts of contaminated groundwater and LNAPLs, it is not clear at this time that the system is preventing the migration of





groundwater from the source area to the non-source area. The conclusions of the OU 1 Source Area Zone Delineation Progress Report (Intera 2002) indicate that hydrocarbon concentrations are measurable downgradient and to the west of the exterior trench (Trench D) (see Figure OU 1-1 for location). This could be an indication that contaminated groundwater from the source area is not being captured by either the interior or exterior trenches or that there is an additional source of contamination.


A preliminary trend analysis of four monitoring locations indicate the following (the locations of the monitoring locations can be found in the OU 1 PSVP [CH2M 2001]): *The Method Detection Limits for all four of the contaminants reviewed (TCE, DCE11, DCE12T, and DCE12C) were too high to detect some of the analytes at several of the locations at their current concentrations.*DCE12C (PRG = 70 ppb) concentrations at U1-067 decreased from approximately 8,600 ppb to 5,510 ppb over a five year period. *DCE12T (MCL = 100 ppb) concentrations at U1-162 have decreased from approximately 70 ppb to 5 ppb over a five year period. *The DCE12C concentrations at U1-667 decreased from approximately 4,300 ppb to 3,300 ppb over the past five years (still above the PRG of 70 ppb). The TCE (MCL = 5ppb) concentrations have decreased from 700 ppb to 240 ppb over a five year period. However, the DCE11 (PRG = 7 ppb) concentrations have increased from approximately 9 to 14 ppb. *At U1-079 all of the analytes reviewed increased over a five year period. TCE increased from approximately 5 to 25 ppb, DCE12T increased from approximately 1 to 6 ppb, and DCE 12C increased from approximately 60 to 350 ppb.


*Source Area - Landfill CapPonding on several areas at the landfills have been identified during CY 2002. This may compromise the integrity of the cap and allow excess infiltration.

*Non-Source Area - Spring Remediation SystemIn the OU 1 Feasibility Study Report (CH2M 1998) and Comprehensive Remedial Investigation Report (MW 1995), several exposure pathways are listed for current and future use. Of these pathways, springs and seeps posses the most problematic for current and future use of groundwater and surface water on Base and off Base.

Analytical results for benzene, cis-1,2 DCE, trans-1,2 DCE, PCE, TCE, vinyl chloride, and chromium at the 19 springs/seeps at OU 1 were reviewed over time. Of the 19 locations, intermittent analytical results from nine locations (U1-303, U1-304, U1-305, U1-306, U1-312,





U1-313, U1-314, U1-317, and U1-318) were available in ERPIMS. These nine locations have been dry for the past several rounds of sampling. Springs U1-311 and U1-319 are not currently monitored. The only spring that currently exhibits groundwater contamination above PRGs is U1-307 (exceeds the PRG for cis-1,2 DCE). However, the water from this spring is collected via the groundwater extraction system at OU 1 and is discharged to the IWTP for treatment.



*A preliminary check between the PSVP sampling requirements and data in ERPIMS showed that the analytical results from several locations were not available. This may be due to the lag time between sampling activities and the uploading of the results into ERPIMS, the possibility that the sampling locations were/are dry, or that the locations were not sampled.


IX. Recommendations *Re-evaluate the non-source area monitored natural attenuation remedial action to determine if it is still applicable in all non-source areas (specifically in the area of measurable hydrocarbon concentrations outside Trench D).*Modify ERPIMS to include a field for springs and seeps that exhibit dry conditions during a sampling event.*Review the long term monitoring sampling and analysis plan to ensure that locations where the hydrocarbon concentrations were located during the Source Zone Area Delineation project (Intera 2001) are monitored.*Proceed with the delineation and excavation of the arsenic contaminated soils at the springs. *Determine if the trenches are containing/capturing the contamination in the source area by evaluating the gradient around the trenches. Additional monitoring points may be necessary to confirm that the prescribed water levels in the sumps are adequate to maintain containment.






2008

*Re-evaluate the risk analysis for OU 1 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors, as explained in the Technical Assessment above. *Re-evaluate the Remedial Investigation data on indoor air and determine if the new action level for TCE (0.43 ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.*Ensure that all gates and fences are locked in accordance with the ROD specified institutional controls.*Implement maintenance activities in a timely manner.*Determine if the plume mean concentrations are decreasing, using the described locations and monitoring frequency outlined in the Performance Standard Verification Plan and the results of the Performance Standard Verification Report, scheduled for 2006.*Ensure that the method detection limits (MDL) are low enough to detect a contaminant of concern (i.e., MDL equal to or less than the MCL or PRG).*Add chromium to the sampling and analysis plan for springs at OU 1.*Collect samples from all locations described in the PSVP.



A protectiveness determination of the remedies associated with WP080 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 1. Therefore, a re-evaluation of potential risk at OU 1 must be conducted before the protectiveness of the current remedies can be determined.

Additional items that need to be addressed are described in the previous issues and recommendations and include: the appropriateness of the monitored natural attenuation remedial action in the area of measurable hydrocarbon concentrations outside Trench D, and determining if the trenches are containing/capturing the contamination in the source area. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 1 during the next Five-Year Review (2008).




Operable Unit 2

I Introduction

Operable Unit 2 consists of two IRP sites, as shown below in Table OU 2-1. Site SS021 requires no further action (HAFB EMR 1991a; CH2M 1996) and has been included in the Five-Year Review for completeness and to document the site background. IRP site WP007, also known as Chemical Disposal Pit 3, consists of two unlined trenches which were used for the disposal of unknown quantities of trichloroethene bottoms from solvent recovery units, sludge from vapor degreasers, and plating tank bottoms. The waste solvents migrated downward through the vadose zone into the shallow aquifer and accumulated as a mobile, dense non-aqueous phase liquid (DNAPL), pooled in topographic lows of a clay aquitard underlying sandier surface soils. Contaminated soils and the pooled DNAPL are the source of shallow groundwater contamination extending approximately 1500 feet downgradient, and beyond the Hill AFB boundary. Since the Record of Decision for Operable Unit 2 (CH2M 1996), OU 2 has become synonymous with WP007, although OU 2 includes both SS021 and WP007. Table OU 2-1. OU 2 Site Identification

Site ID Site Name WP007 CHEMICAL PIT 3 SS021 PERIMETER ROAD

II Site Chronology


III Background

SS021 (Perimeter Road) was reportedly the site of previously unidentified dumping of waste solvents prior to 1979, in addition to dumping known to have occurred at a number of sites now associated with other Operable Units. The Record of Decision for Operable Unit 2 (CH2M 1996) states that SS021 has been found to be free of contamination except in those areas being addressed as part of existing Operable Units, and that no further action at that site is needed. IRP site WP007, Chemical Disposal Pit 3, is located approximately 100 feet west of Perimeter Road, near the northeast boundary of Hill AFB, as shown on Figure OU 2-1. Past disposal of chlorinated solvents at WP007 has contributed to on- and off-Base contamination of the natural environment (Radian 1992a). A steep, terraced, northeast-facing escarpment leading from the Base to the Weber River Valley below separates the on-Base portion of OU 2 from the off-Base portion. There is about 300 feet of relief between Hill AFB and the valley. WP007 consists of two unlined trenches several feet wide and approximately 50 to 100 feet long (Radian 1992a). The exact size and depth of the trenches are unknown. The facilities of the Source Recovery System (SRS) and other structures supporting the removal, treatment, and investigation of DNAPL in the subsurface are constructed over and obscure the trenches. From 1967 to 1975 the trenches were used for the disposal of unknown quantities of trichloroethene bottoms from solvent recovery units and sludge from vapor degreasers (CH2M 1996). An


unknown volume of plating tank bottoms was disposed at this site in the early 1940s (CH2M 1996). The estimated volume of waste solvents disposed in the trenches exceeds 10,000 gallons, and may exceed 100,000 gallons (HAFB EMR 1991c; CH2M 1996). The waste solvents migrated downward through the vadose zone into the shallow aquifer and accumulated as a mobile phase DNAPL, pooled in topographic lows of the Alpine Formation, a clay aquitard underlying the sandier soils of the Provo Formation (HAFB EMR 1991b; Radian 1992a). The DNAPL is approximately 70% TCE (URS 1999). Contaminated soils near the trenches and the pooled DNAPL are the source of shallow, dissolved phase groundwater contamination extending approximately 1500 feet downgradient, and beyond the Hill AFB boundary (HAFB EMR 1991b; Radian 1992a; CH2M 1996; URS 2002a). Downgradient seeps and springs have also exhibited contamination. Concentrations of TCE in groundwater exceeding 10,000 µg/L occur both on- and off-Base. Groundwater contamination appears limited to the shallow, unconfined aquifer of the Provo Formation, above the Alpine Formation aquitard. The Record of Decision for Operable Unit 2, issued in 1996, specifies both source and non-source remedies to address contamination due to WP007 (CH2M 1996). The source area corresponds approximately to the on-Base regions of contamination, the non-source areas to the off-Base regions. One of the remedies specified by the ROD is a low permeability containment wall encircling the source area to reduce the potential for further contamination of groundwater. After the wall was built, however, an additional accumulation of free-phase DNAPL was identified outside of the wall (URS 1999). This accumulation is informally known as either the "Griffith Pool" or the "G-Pool."

IV Remedial Actions

The remedial actions at OU 2 are described in detail in Section IV of the WP007 (Chemical Pit 3) Site Summary. Source Area - Containment Wall The containment wall is a vertical, low permeability, soil/bentonite slurry wall encircling the OU 2 source area, isolating the source area from the shallow aquifer (CH2M 1997). The containment wall acts as a barrier to contaminant migration and, in conjunction with extraction of groundwater from the source area, is intended to produce an inward hydraulic gradient along the western portion of the wall. The upgradient control system (UCS) is a gravel trench upgradient from the containment wall designed to eliminate groundwater mounding, which could lead to slope instability and failure (CH2M 1997). Associated sumps, pumps and piping convey intercepted groundwater to either the Source Recovery System process plant or the Air Stripper Treatment Plant (ASTP) for treatment and disposal. Source Area – Source Recovery System The SRS consists of a free-product and contaminated groundwater recovery well field and a process treatment facility. In conjunction with the containment wall, the SRS extraction well field provides hydraulic control in the source area by lowering the elevation of shallow groundwater within the wall (CH2M 1997). The SRS process plant also receives contaminated groundwater from the G-Pool.


DNAPL from other wells within the containment wall is removed using a portable DNAPL pump assembly. Since its initial operation in 1993 through 2001, approximately 43,500 gallons of DNAPL have been recovered from the source area and shipped off-Base (URS 2002b). Current piping configurations allow the treated groundwater to be discharged either to the ASTP or to the Hill Air Force Base Industrial Wastewater Treatment Plant for further treatment. Source Area – Treatability Studies Several pilot-scale treatability studies involving innovative technologies have been conducted in the source area. Approximately 6,000 gallons of DNAPL have been removed from the source area as the combined result of treatability studies and subsequent full-scale innovative treatments. Source Area – Soil Vapor Extraction (SVE) The source area SVE system specified in the ROD to remove VOCs from subsurface soils has not been implemented, and no timetable is specified in the ROD for implementation. The schedule will be established pending the completion of treatability studies. In 2002, a pilot-scale soil vapor extraction study was recommended to Hill AFB and is currently under review. Source Area – Surface Cap A surface cap over the source area, designed to prevent infiltration of surface water and further degradation of groundwater, has not been built. The ROD indicates the cap is to be delayed until source area treatment by either conventional or innovative technologies is completed and their effectiveness evaluated. Source and Non-Source Area – Air Stripper Treatment Plant (ASTP) The ASTP is designed to treat extracted groundwater containing relatively low concentrations of VOCs from both the source and non-source areas (CH2M 1997). It can treat flows from the UCS, the SRS (after initial treatment in the steam stripper), and the North Interceptor Trench (NIT, discussed below). In addition, it can treat groundwater extracted from OU 1. Treated water flows by gravity to a sanitary sewer connection leading to the Central Weber Sewer Improvement District (CWSID) treatment facility. During 2001, VOC concentrations in ASTP effluent were consistently below detection limits (URS 2001). Non-Source Area – Interceptor Trenches The NIT is a gravel trench drain located near the leading edge of the off-Base plume, designed to intercept contaminated groundwater to prevent further downgradient migration (CH2M 1997). A sump located at the lowest pipe entry elevation of the NIT receives groundwater intercepted by the trench, and also receives water intercepted by similar trenches at springs U2-304 and U2-326. The groundwater collected from the NIT sump is sent to the ASTP for treatment. The NIT has been upgraded to pump untreated NIT flows directly to CWSID. Institutional Controls A Continuing Order (AFI 32-7020) has been issued to restrict disturbance of contaminated soil and groundwater and to restrict installation of water wells on-Base at OU 2 (HAFB 1998). The Utah Division of Water Rights has also restricted water well drilling and the use of shallow groundwater at off-Base areas near OU 2. On-Base remediation facilities are not fenced, but are locked when unoccupied. Off-Base remediation facilities are fenced and/or posted with signs.


Environmental Monitoring The ROD requires a program of long-term monitoring for contaminants and treatment system performance. A Performance Standard Verification Plan (CH2M 2001) was completed in 2001, describing the data needed to assess whether the remedial actions specified in the ROD are operating properly and successfully, and establishing a program to collect the data. The PSVP specifies annual reporting of operations and maintenance activities for the treatment systems, the annual cost of O&M, and an annual groundwater sampling report. The annual groundwater sampling report is a summary of the groundwater sampling conducted during the previous year, and includes data reporting and charting; it does not, however, include data interpretation. Thorough interpretation and evaluation of the data is deferred until 2006, when a Performance Standard Verification Report is scheduled. All environmental monitoring data, derived from either the O&M or groundwater sampling reporting, are submitted to ERPIMS.


The 1998 Five-Year Review contained no specific recommendations regarding the remedies at OU 2. The estimate of initial free-phase DNAPL accumulation in the G-Pool, outside of the containment wall, has been refined from 5,000-10,000 gallons (1998) to 2,800 gallons (currently). Approximately 2,500 gallons have been recovered from the G-Pool. Many incremental improvements have been achieved in the operation of the remedies.

VI Five-Year Review Process Site review was conducted per the process described in this report for the overall 2003 FYR. VII Technical Assessment

Results of the technical assessment of the remedies at OU 2 are presented in Table OU 2-3. Additional details are provided in Section VII of the WP007 Site Summary. Table OU 2-3. Technical Assessment Summary for OU 2

Technical Assessment* Site ID Remedy Question A Question B Question C

Protectiveness Next Five-

Year Review

WP007 Source removal, containment, and

institutional controls No No Yes

Cannot be determined until

further information is obtained

2008

SS021 Not required, NFRAP site NA NA NA NA Not

required

OU 2 Source removal, containment, and

institutional controls No No Yes

Cannot be determined until

further information is obtained

2008

* Question A: Is the remedy functioning as intended by the decision documents? Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the

time of the remedy still valid? Question C: Has any other information come to light that could call into question the protectiveness of the remedy? NA = Not applicable


Question A. Is the remedy functioning as intended by the decision documents? No. Some portions of the remedy appear to be functioning as intended, while others do not. The SRS process plant, treatability studies and innovative treatments, ASTP, and institutional controls are functioning as intended. However, the SRS extraction wells, the containment wall, and the NIT may not be functioning as intended. Groundwater elevations are not consistently below action levels stated in the PSVP for the SRS well field. An inward gradient is not being maintained along the western segment of the containment wall. And a preliminary evaluation of groundwater elevation and TCE concentration data in the vicinity of the NIT suggest that there is no intercept mechanism across the entire width of the off-Base plume and during the spring months the NIT fails to intercept all of the contaminated water. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? No. The risk factors used to develop the cleanup levels for Beta-BHC, methylene chloride, tetrachloroethene, and trichloroethene at OU 2 are now 10-times to 10,000-times more stringent (EPA Region III 2002; URS 2002c). A corrective action management unit (CAMU) was designated for consolidation of soil generated from construction activities during remedial actions defined in the OU 2 ROD (CH2M 1996). The soil was specified for use as grading material to provide proper slope for a surface cover. The CAMU at OU 2 was designated in compliance with the 1993 CAMU rule applicable at the time of the signing of the ROD. Since the signing of the ROD, the 1993 CAMU rule has been revised (2002). Because no changes to the scope of the CAMU have been made at OU 2, the action of creating a CAMU for purposes specified in the OU 2 ROD is in compliance with the revised CAMU rule. The baseline risk assessment (BRA) (Radian 1992b) considered the inhalation of indoor air as a potentially significant current and future pathway for both onsite and offsite residential exposure. Since then, EMR, EPA, and Utah DEQ have jointly established a new action level for TCE concentration in indoor air of 0.43 ppbv. In addition, new homes have been built and new subdivisions developed in formerly agricultural areas downgradient of the source (Himle, C. 2003). The new indoor action level for TCE, combined with the increasing residential use downgradient of the source, raises the potential for indoor air quality issues, by way of soil gas migration, that may not have been previously addressed.

Question C. Has any other information come to light that could call into question the protectiveness of the remedy? Yes. In 1997, after construction of the containment wall, an accumulation of mobile-phase DNAPL was discovered outside of the containment wall during a treatability study. This accumulation, the “G-Pool,” was adjacent to the northeast corner of the containment wall and contained an estimated 2,800 gallons of DNAPL. Approximately 2,500 gallons of DNAPL have been recovered from the G-Pool, and small volumes of free-phase DNAPL continue to be recovered. Groundwater extraction wells maintain the water level below a specified elevation in the G-Pool, reducing the potential of the G-Pool as a continuing source of contamination. Aside from reducing the hydraulic gradient across the G-Pool, the containment wall does not control contaminant flux out of the G-Pool. In addition, a recent review of time-series data (URS 2003) of TCE concentration in U2-675 raises the possibility of increasing contaminant concentrations in groundwater downgradient of the NIT.


VIII Issues

1. A joint evaluation of the SRS and the containment wall is ongoing. Protectiveness provided by these remedies cannot be determined until the data have been thoroughly evaluated and interpreted.

2. The proper function of the SRS extraction well remedy cannot be determined because the

action level stated in the PSVP does not correspond to the water level elevation that can be achieved within the containment wall with maximum pumping of these wells. No rationale for this action level is given in the PSVP.

3. A preliminary evaluation of groundwater elevation and TCE concentration data from wells in

the vicinity of the NIT suggest the possibility that during the spring months the NIT fails to intercept contaminated groundwater. Also, based on the latest interpretation of the off-Base plume (see Figure OU 2-1), the NIT does not intercept the entire width of the plume.

4. The data collected by the LTM contractor are not readily available to the O&M contractor,

though they may have a bearing on the operation of the remedies. 5. Since the baseline risk assessment (Radian 1992b), EMR, EPA, and Utah DEQ have jointly

established a new action level for TCE concentration in indoor air of 0.43 ppbv. In addition, new homes have been built and new subdivisions developed in formerly agricultural areas downgradient of the source.

6. The leading edge of the plume is very near the southern boundary of NE ¼, Sect. 29, T5N

R1W, which is not subject to water rights restrictions imposed by Hill AFB in conjunction with the Utah Department of Natural Resources (HAFB 1998). Should the plume advance, it could impinge on this quarter section.

7. A thorough review of several portions of the remedial systems addressing contamination at

OU 2 may be justified sooner than the PSVR scheduled in 2006 because they have been in operation since 1993.

8. The ROD established a CAMU according to the rule in place in 1993. Changes to the

materials in, or usage of, the CAMU may not comply with rule changes. IX Recommendations and Follow-up Actions for OU 2

1. Jointly evaluate the effectiveness of the SRS and the containment wall. 2. Identify the appropriate action level for well field operations and document new level and

rationale in the PSVP. 3. Water level and analytical data in the vicinity of the NIT, the performance of the NIT, and the

location of the NIT with respect to the dissolved-phase plume should be thoroughly evaluated.

4. Expedite submittal of LTM data to ERPIMS for timely review of remedy effectiveness.


5. Continue use of the portable DNAPL pump assembly to remove free-phase DNAPL from

wells. Consider purchase of a second system, which would enable simultaneous recovery of DNAPL from two separate wells.

6. Investigate the relationship between new residential development and the plume. 7. Re-evaluate the risk analysis for OU 2 to determine if revised contaminant action levels are

warranted based on new standards and toxicity factors as explained in the Technical Assessment above.

8. Consider the need to restrict water rights in the northeast quarter of Sect. 29, T5N R1W. 9. Evaluate whether a thorough review of the remedies at OU 2 can be performed before 2006.

10. Ensure that regulatory approval is granted before the CAMU is used for any future remedial

actions. X Protectiveness Statement for OU 2

A protectiveness determination of the remedies associated with OU 2 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 2. Therefore, a re-evaluation of potential risk at OU 2 must be conducted before the protectiveness of the current remedies can be determined. The remedies specified by the ROD and now in-place constitute an appropriate response to contamination resulting from WP007 if operating as designed. A comprehensive evaluation of relevant data generated since remediation began is needed, however, in order to make a strong protectiveness statement by comparing operating data against design objectives. An assessment of the joint performance of the containment wall and the SRS, in operation together since 1996 is needed to make a clear statement about the prevention of continuing downgradient groundwater stemming from the source area. This assessment, along with a completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 2 during the next Five-Year Review (2008).

XI Next Review

The next FYR for OU 2 is required by 2008. No future review is required for Site SS021 (Perimeter Road) because no further remedial action is planned at this site.


(CH2M 1996) Final Record of Decision and Responsiveness Summary for Operable Unit 2, CH2M Hill, September 1996. (CH2M 1997) Remedial Design Report and Work Plan Schedule A and B Construction Operable Unit 2, CH2M Hill, December 1997.


(CH2M 2000) Draft Remedial Action Report Operable Unit 2 North Interceptor Trench, Spring U2-326 Interceptor Trench, Containment Wall, and Air Stripper Treatment Plant, CH2M Hill, March 2000. (CH2M 2001) Performance Standard Verification Plan Operable Unit 2, CH2M Hill, November 2001. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1991a) Decision Document for Perimeter Road, Site SS21, Hill AFB EMR, June 1991. (HAFB EMR 1991b) Focused Feasibility Study for Operable Unit 2, Hill AFB EMR, February 1991. (HAFB EMR 1991c) Record of Decision for Interim Action at Operable Unit 2, Final, HAFB EMR, August 1991. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (Himle, C. 2003) Himle, C., O&M Contractor, URS, Personal Communication, 03 March 2003. (MW 2000) Final Remedial Action Project Report For Operable Unit 2 Spring U2-304 Seep Intercept System, Montgomery Watson, July 2000. (Radian 1992a) Remedial Investigation Report for Operable Unit 2 Sites WP07, SS21 Volume 1 Report and Appendices A & B, Radian, July 1992. (Radian 1992b) Baseline Risk Assessment for Operable Unit 2 Sites WP07, SS21 Volume 1 Report, Radian, March 1992. (Radian 1994) Operable Unit 2 Source Removal System and Industrial Waste Treatment Plan Modifications Construction Report, Radian, January 1994. (Rice 1997) AATDF Surfactant/Foam Process for Aquifer Remediation, Rice University, November 1997. (URS 1999) Final Dense Nonaqueous Phase Liquid (DNAPL) Source Delineation Report Operable Unit 2, URS Corporation, September 1999. (URS 2001) Final 2000 Cost and Performance Report, Operable Unit 2, Hill Air Force Base, Utah, URS, 15 February 2001.


(URS 2002c) Memorandum, Comparison of Standards and Cleanup Levels at Hill AFB, URS, 16 December 2002. (URS 2002b) Final Operable Unit 2 Panel 1 and 5 Surfactant Enhanced Aquifer Remediation (SEAR) Report, URS Corporation, February 2002. (URS 2002a) 2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT, URS, 11 February 2002. (URS 2002c) 2001 Cost and Performance Report Operable Unit 2, URS, March 2002. (URS 2003) Draft 2002 Cost and Performance Report, Operable Unit 2, Hill Air Force Base, Utah, URS Corporation, March 2003.


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OU 2 OPERABLE UNIT 21981 Investigations begin at OU 2 Focused Feasibility Study for Operable Unit 2

07 1987 OU 2 placed on the National Priorities List

Focused Feasibility Study for Operable Unit 2

1998 First Five-Year Review of remedial actions at OU 2

Hill AFB Five-Year Review, September 1998

WP007 CHEMICAL PIT 31967 Disposal of wastes begins in

Chemical Disposal Pit 3Wastes consist of solvents and sludges from HAFB degreasing operations. Disposal continued to 1975. Volume of disposed wastes unknown, estimated between 100,000 and 1,000,000 gals.


1983 Volatile organic compounds first identified at OU 2

How contaminants were identified, and in what media, is not described in the reference document (ROD).






1986 High levels of VOCs confirmed in shallow groundwater near Base boundary

Contaminants found in springs downgradient from the disposal trenches. Maximum TCE concentration detected in groundwater off-Base is 11,000 ug/L.


1986 Response measures to protect off-base users of shallow groundwater

Five properties provided alternate sources of water. Two of the five provided municipal drinking water; the remaining three provided with alternate sources of irrigation water. Note that the year(s) in which this occurred is uncertain. It is not specified in the reference document.


05 1986 Community participation begins Record of Decision for Interim Action at Operable Unit 2, Final

08 1991 Record of Decision for interim action

Pump-and-treat system for removal and destruction of free-phase DNAPLs from groundwater is selected as the remedy for interim action. Operating life is expected to be approximately two years following a one year construction period.


03 1992 Baseline Risk Assessment issued Estimated carcinogenic risk values for the off-site future residential scenarios, due to the presence of TCE in groundwater, exceeded the CERCLA risk range site remediation goal.

Baseline Risk Assessment for Operable Unit 2 Sites WP07, SS21 Volume 1 Report





12 1993 Initial extended (6 months) operation of the source recovery system (SRS)

Construction of the SRS was completed in August 1993, implementing the 1991 ROD for interim action. The initial period of sustained operation began in December 1993 and continued through the first part of June 1994. Pumped 22,904 gallons of free-phase DNAPL from the aquifer during initial extended operation and the system startup test (October - November 1993); additional 456 gallons of DNAPL generated by steam stripping/recondensation.

System Evaluation Report SRS Commissioning, Startup, and Initial Operation Interim Remedial Action, 2

1996 Pilot-scale treatability studies Three partitioning interwell tracer tests and two surfactant enhanced aquifer remediation tests were conducted in a portion of the DNAPL pool in the vicinity of the disposal trenches near Panels 3 and 4. PITTs were determined to be effective and were later used to characterize the entire source area. Full-scale SEARs were also judged to be feasible in portions of the source area, and were conducted in 2000, 2001, and 2002, each in different portions of the source.

2001 Cost and Performance Report Operable Unit 2

09 1996 Record of Decision The selected remedy addresses contaminated groundwater, contaminated soil, and contaminated surface water at OU 2. Two components are addressed: the source area and non-source area. Source area remedy: encircling vertical barrier; shallow groundwater extraction, treatment, and discharge; soil vapor extraction; continued operation of the SRS; a surface cap; treatability studies. Non-source area remedy: shallow groundwater extraction, treatment, discharge; continued collection, treatment and discharge of water from springs and seeps. Remedy for both areas includes environmental monitoring and institutional controls.

Final Record of Decision and Responsiveness Summary for Operable Unit 2





12 1996 Source containment system constructed

Containment wall and upgradient control trench constructed. UCS O&M and Performance Verification Plan Operable Unit 2

1997 The Air Stripper Treatment Plant is constructed

The ASTP treats contaminated groundwater through an air stripper treatment process.


1997 Additional PITTS performed to characterize the DNAPL source

Additional PITTs performed in late 1997 and 1998 to characterize the entire subsurface channel containing DNAPL. PITTs conducted in panels 1 through 5.


1997 DNAPL pool discovered outside of the containment wall

During the characterization of the entire subsurface channel, a DNAPL pool was discovered outside of the northeast corner of the containment wall. This DNAPL pool is denoted the G-pool.


1997 Additional treatability studies conducted

A surfactant flood involving a foam surfactant to enhance subsurface sweep recovered little DNAPL.

Approximately 2,000 gals DNAPL recovered as a result of steam injection and the installation of the steam injection wellfield.


1997 Off-base extraction system constructed

The North Intercept Trench is constructed. The NIT is a groundwater collection trench designed to cut off the leading edge of the off-Base plume. The water is pumped uphill to the ASTP.






03 1997 Surfactant/foam flood demonstration project in source area

AATDF Surfactant/Foam Process for Aquifer Remediation

1998 Additional off-Base trench completed near the NIT to drain a seasonal spring

Off-Base trench U2-236 completed to drain a seasonal spring located near the NIT. Water from the trench is pumped to the NIT sump, where it is conveyed for treatment at either the IWTP or the ASTP.


1998 Four large-scale PITTs conducted in source area

Final Dense Nonaqueous Phase Liquid (DNAPL) Source Delineation Report Operable Unit 2

1999 Spring 304 Intercept System constructed

Final Remedial Action Project Report For Operable Unit 2 Spring U2-304 Seep Intercept System

1999 New extraction well field installed in the G-Pool

17 wells drilled and developed in the G-pool. The well field was connected to the existing SRS piping to convey DNAPL and groundwater extracted from the G-Pool to the SRS for phase separation and treatment. Approximately 2,200 gals of additional DNAPL removed since the start-up of the well field.


1999 PITT conducted in the G-Pool After the mobile DNAPL was extracted from the G-Pool well field, the remaining DNAPL was characterized using a PITT. An additional 350 gals of DNAPL were recovered during the PITT.






1999 Gravel interceptor trench for spring U2-304

A gravel interceptor trench for spring U2-304 was constructed. The purpose of the trench is to collect contaminated groundwater and prevent it from advancing in the off-Base plume.


2000 First full-scale SEAR completed The first full-scale SEAR at OU 2 was completed in Panel 2, recovering 430 +/- 59 gallons of DNAPL.


2000 A cometabolic bioventing test was conducted in the source area

The Remediation Technology Development Forum (RTDF) funded a cometabolic bioventing test in the source area of OU 2. A vadose zone PITT was completed using the RTDF well field and acclimation of the subsurface microbes was initiated.


01 2000 Air strippers placed on-line The air strippers were placed on-line in January 2000 after a successful demonstration of a datalink required by South Weber City to monitor the volume of water treated by the ASTP and sent to the Central Weber Sewer Improvement District (CWSID). Over 5 million gallons of contaminated water from the UCS and NIT were treated and sent to the CWSID.


2001 SRS modified to enable breakdown of surfactant in the SEAR effluent

Modifications to the SRS were required to break down surfactant in the SEAR effluent, including a hydrolysis unit that treated the wastewater to mitigate foam generation downstream of the SRS at the IWTP and the North Davis Publicly Owned Treatment Works (POTW). During the Panel 1 SEAR, approximately 31,000 pounds of sodium hydroxide were used to treat over 350,000 gals of surfactant-laden wastewater.






2001 SEAR conducted in Panel 1 Approximately 1,100 gals of DNAPL were recovered as a result of the application of a SEAR in Panel 1. Foam injection was used to improve subsurface sweep. A post-SEAR PITT suggests that additional DNAPL remains in the southern portion of the panel.


2002 Panel 1 SEAR conducted from September 21 to Novemenber 1

Final Operable Unit 2 Panel 1 and 5 Surfactant Enhanced Aquifer Remediation (SEAR) Report

SS021 PERIMETER ROAD06 1991 Decision to no longer track

Perimeter Road (SS021) as an IRP site

Decision based on the results of a 1988 soil gas study documented in: Radian, 1990. Site Evaluation Report for Perimeter Road and the Spoils Area. August 1990.

Decision Document for Perimeter Road, Site SS21

09 1996 Record of Decision Perimeter Road (IRP Site SS021) is found to be free of contamination except in those areas being addressed as part of existing OUs. No further action is needed for Perimeter Road as part of OU 2.

Final Record of Decision and Responsiveness Summary for Operable Unit 2




XIII Five-Year Review of Sites in OU 2

Operable unit review results are summaries of findings for all of the sites in each operable unit. The following site summaries present a detailed review of each IRP site. Therefore, much of the information presented in the Site Summaries is a duplicate of what was presented in the OU Summary. The reader is encouraged to use the Site Summary to obtain details on specific contaminants of concern and the technical assessment for each site.


OU 2 WP007 CHEMICAL PIT 3


III. Background IRP site WP007, Chemical Disposal Pit 3, is located approximately 100 feet west of Perimeter Road, near the northeast boundary of Hill AFB, as shown on Figure OU 2-1. Past disposal of chlorinated solvents at WP007 has contributed to on- and off-Base contamination of the natural environment (Radian 1992a). A steep, terraced, northeast-facing escarpment, 310 feet high and leading from the Base to the Weber River Valley below, separates the on-Base portion of OU 2 from the off-Base portion.

The exact size and depth of the trenches is not known. The facilities of the Source Recovery System and other structures supporting the removal, treatment, and investigation of DNAPL in the subsurface are constructed over and obscure the trenches. In addition to solvent disposal, an unknown volume of plating tank bottoms was disposed at this site in the early 1940s (CH2M 1996). The estimated volume of waste solvents disposed in the trenches exceeds 10,000 gallons, and may exceed 100,000 gallons (HAFB EMR 1991c; CH2M 1996) and is approximately 70% TCE (URS 1999).

Contaminated soils near the trenches and the pooled DNAPL are the source of shallow, dissolved phase groundwater contamination extending approximately 1500 feet downgradient, and beyond the Hill AFB boundary (HAFB EMR 1991b; Radian 1992a; CH2M 1996; URS 2002a). Downgradient seeps and springs have also exhibited contamination. Concentrations of TCE in groundwater exceeding 10,000 ug/L occur both on- and off-Base. Groundwater contamination appears limited to the shallow, unconfined aquifer of the Provo Formation, above the Alpine Formation aquitard.

The Record of Decision for Operable Unit 2, issued in 1996, specifies both source and non-source remedies to address contamination due to WP007 (CH2M 1996). The source area corresponds approximately to the on-Base regions of contamination, the non-source areas to the off-Base regions. One of the remedies specified by the ROD is a low permeability containment wall encircling the source area to reduce the potential for further contamination of groundwater. After the wall was built, however, an additional accumulation of free-phase DNAPL was identified outside of the wall (URS 1999). This accumulation is informally known as either the "Griffith Pool" or the "G-Pool."

I. Introduction IRP site WP007, also known as Chemical Disposal Pit 3, consists of two unlined trenches, several feet wide and approximately 50 to 100 feet long (Radian 1992a), which were used from 1967 to 1975 for the disposal of unknown quantities of trichloroethene waste from solvent recovery units, sludge from vapor degreasers, and possibly plating tank bottoms (CH2M 1996). The waste solvents migrated downward through the vadose zone into the shallow aquifer and accumulated as a mobile phase DNAPL, pooled in topographic lows of a clay aquitard underlying sandier surface soils of the Provo Formation (HAFB EMR 1991b; Radian 1992a). Contaminated soils and the pooled DNAPL are the source of shallow groundwater contamination extending approximately 1500 feet downgradient, and beyond the Hill AFB boundary.






Source Area - Containment WallThe containment wall is a vertical, low permeability, soil/bentonite slurry wall encircling the






GW BETA BHC (BETA HEXACHLOROCYCLOHEXANE) 0.01 ug/L

SW BETA BHC (BETA HEXACHLOROCYCLOHEXANE) 0.01 ug/L



SW GAMMA BHC (LINDANE) 0.2 ug/L

GW METHYLENE CHLORIDE 6 ug/L

SW METHYLENE CHLORIDE 6 ug/L









* Eliminate the sources of groundwater contamination either through source control or removal in accordance with the Utah Corrective Action Cleanup Standards Policy - UST and CERCLA Sites.* Meet chemical-specific ARARs. Restoration goals are drinking water MCLs. Meeting MCLs will satisfy restoration goals of the State Groundwater Quality Protection Rule.* Prevent further degradation of groundwater quality in accordance with the Utah Corrective Action Cleanup Standards Policy - UST and CERCLA Sites.* Remove as much of the DNAPL as practicable.

* The goal of the remedial action is to restore the shallow groundwater to its beneficial use.





OU 2 source area, isolating the source area from the shallow aquifer (CH2M 1997). The wall is approximately 1500 feet long, varies in depth from 67 to 92 feet bgs, and is completed a minimum of 35 feet into the lower permeability soils underlying the shallow aquifer. The containment wall provides two protective functions: 1) a low permeability physical barrier to lateral contaminant migration, and 2) a hydraulic barrier whereby the extraction of water from the source area within the wall produces an inward hydraulic gradient along the southern, western and northern segments of the wall. Maintenance of an inward gradient on the eastern segment of the wall is not feasible due to the steep slope on the east. Eastward migration of contaminated groundwater is mitigated, however, by keeping the groundwater elevation below 4665 feet above mean sea level (amsl) on both sides of the eastern wall segment (CH2M 2001). Twenty-one piezometers spaced around the perimeter of the wall (eight inside and 13 outside of the wall) constitute a network of eight piezometer nests used to monitor the gradient across the wall.

The upgradient control system is an element of the containment wall system designed to eliminate groundwater mounding on the upgradient side of the containment wall, which could lead to slope instability and failure (CH2M 1997). The UCS is a gravel trench excavated to depths ranging from 21.5 to 34 feet, approximately 700 feet long, and aligned parallel to and 15 to 25 feet upgradient from the containment wall. Associated sumps, pumps and piping convey intercepted groundwater to either the Source Recovery System process plant or the Air Stripper Treatment Plant for treatment and disposal.

Source Area – Source Recovery SystemThe SRS consists of a free-product and contaminated groundwater recovery well field and a process treatment facility. The primary functions of the SRS are to remove DNAPL from the source area groundwater and recover it by phase separation; separate dissolved contaminants from the aqueous phase using steam stripping; and meet effluent discharge objectives (Radian 1994; URS 2002a). In addition, the SRS treats groundwater and fluids extracted during enhanced DNAPL removal technology applications, which have been conducted episodically at the site since 1996. In conjunction with the containment wall, the SRS extraction well field provides hydraulic control of the source area by lowering the elevation of shallow groundwater within the wall (CH2M 1997).

The original SRS well field within the containment wall consisted of four wells extracting both contaminated groundwater and free-phase DNAPL (Radian 1994). Usually three wells (U2-001, U2-031, and U2-033R) now operate, removing only contaminated groundwater from within the wall; DNAPL is no longer recovered from the wells (URS 2002a). Extracted groundwater is conveyed to the Source Recovery System process plant for treatment and disposal. All conveyance piping between the wellfield and the treatment plant is double walled. Total flow from the wells range from approximately one to ten gpm, and varies depending on season and during other remediation activities (such as surfactant flooding) within the containment wall (URS 2002a). Pumping rates of wells within the containment wall have apparently decreased with time, possibly in response to the combined effect of the containment wall and the UCS (URS 2002a).

DNAPL is still encountered in other wells within the containment wall, however, and is removed using a portable DNAPL pump assembly; wells requiring DNAPL removal are





identified by monthly soundings (Himle, C. 2003). Approximately 20 gallons per month can be recovered using the portable assembly, but the system can only operate during warm weather.

Contaminated groundwater and other fluids (from enhanced recovery activities) extracted from the source area are piped to one of three phase separators. DNAPL is separated from groundwater by gravity and transferred to a solvent storage tank, where it is accumulated for disposal off-Base at a RCRA permitted facility. Since its initial operation in 1993 through 2001, approximately 43,500 gallons of DNAPL have been recovered from the source area and shipped off-Base (URS 2002b).

Contaminated water separated from the DNAPL is treated using a steam stripper. Highly concentrated solvent vapor is condensed and recycled to the phase separators, and treated water is transferred to an effluent holding tank. Current piping configurations allow the treated effluent to be discharged either to the air stripper treatment plant or to the Hill Air Force Base Industrial Wastewater Treatment Plant for further treatment.

The SRS process plant also receives contaminated groundwater from the G-Pool. Four extraction wells typically operate in the G-Pool, at a combined flow rate of from less than one to approximately 10 gpm (URS 2002a). A fixed set of wells is not pumped; instead, the pumped wells are varied according to observed VOC concentrations in groundwater and to maintain hydraulic control of the contaminated groundwater to prevent downgradient migration.

Source Area – Treatability StudiesSeveral pilot-scale treatability studies involving innovative technologies have been conducted in the source area. These include partitioning inter-well tracer tests (PITTs) to estimate the volume of immobile residual DNAPL remaining in the source area aquifer (URS 1999); surfactant enhanced aquifer remediations (SEARs) to remove immobile DNAPL (URS 2003); a SEAR involving a surfactant foam, intended to improve the subsurface sweep of surfactant (Rice University, et al. 1997); steam injection to mobilize residual DNAPL (URS 2002b); and a cometabolic bioventing application designed to remove VOC contamination in vadose zone soils by enhancing the growth of naturally occurring, VOC-consuming bacteria. The success of the pilot-scale PITT and SEAR studies led to PITT characterization of the entire source area and the application of three full-scale SEAR applications in the northern portion of the source area (URS 2003). Approximately 6,000 gallons of DNAPL have been removed from the source area as the combined result of treatability studies and subsequent full-scale innovative treatments.

Source Area – Soil Vapor ExtractionThe source area SVE system specified in the ROD to remove VOCs from subsurface soils has not been implemented, and no timetable is specified in the ROD for implementation. The schedule will be established pending the completion of treatability studies. In 2002 a pilot-scale soil vapor extraction study was recommended to Hill AFB and is under review.

Source Area – Surface CapA surface cap over the source area, designed to prevent infiltration of surface water and





further degradation of groundwater, has not been built. The ROD indicates the cap is to be delayed until source area treatment by innovative technologies is completed and their effectiveness evaluated.

Source and Non-Source Area – Air Stripper Treatment PlantThe ASTP is designed to treat extracted groundwater containing relatively low concentrations of VOCs from both the source and non-source areas (CH2M 1997). It can treat flows from the UCS, the SRS (after initial treatment in the steam stripper), and the North Interceptor Trench (discussed below). In addition, it can receive extracted groundwater from OU 1.

Prior to treatment by the ASTP, influent enters a 4,000-gallon storage feed tank. When the tank reaches a pre-determined level, a feed pump delivers contaminated water to one of two air strippers, each rated at 150 gallons per minute (gpm). Treated water flows by gravity to a sanitary sewer connection leading to the Central Weber Sewer Improvement District treatment facility. During 2001, VOC concentrations in ASTP effluent were consistently below detection limits (URS 2001). The CWSID requires total VOC concentrations discharged to the sanitary sewer to be below 2.13 ppm (URS 2001).

Non-Source Area – North Interceptor TrenchThe NIT is a gravel trench drain located near the leading edge of the off-Base plume, designed to intercept contaminated groundwater to prevent further downgradient migration (CH2M 1997). It extends roughly halfway across the plume, and is approximately 500 feet long, 50 feet deep, with perforated horizontal pipes at depths of approximately 22 and 35 feet bgs. A sump located at the lowest pipe entry elevation of the NIT receives groundwater intercepted by the trench, and also receives water intercepted by similar trenches at springs U2-304 and U2-326. Double-walled high-density polyethylene (HDPE) piping conveys untreated groundwater from the NIT sump to the ASTP for treatment. The NIT has been upgraded to pump untreated NIT flows directly to CWSID.

Non-Source Area – Spring U2-326 Interceptor TrenchThe U2-326 interceptor trench is located northwest of the NIT, and consists of a gravel trench approximately 163 feet long with perforated horizontal pipes at depths of approximately 12 and 20 feet bgs (CH2M 2000). Like the NIT, the trench is designed to intercept contaminated groundwater near the leading edge of the off-Base plume to prevent further downgradient migration. Groundwater intercepted by the trench is conveyed to the NIT sump, where it is subsequently conveyed to the ASTP for treatment.

Non-Source Area – Spring U2-304 Interceptor SystemThis passive system is located off-Base in the central portion of the dissolved contaminant plume (MW 2000). The system collects seasonal seepage from Spring U2-304 and conveys it by gravity to the NIT sump, where it is subsequently conveyed to the ASTP for treatment. The objective of the system is to prevent potential exposure to indigenous plants and animals, livestock, and humans.

Institutional ControlsA Continuing Order (HAFB 1998) has been issued to restrict disturbance of contaminated





soil and groundwater and to restrict installation of water wells on-Base at OU 2. The Utah Department of Natural Resources, Division of Water Rights also has restricted water well drilling and the use of shallow groundwater at off-Base areas near OU 2.

On-Base remediation facilities are not fenced, but are locked when unoccupied. Warning signs are posted at multiple locations in the source area. Off-Base remediation facilities are fenced and/or posted with signs. Only one of the facilities, U2-326, has a locked gate; fences surrounding the NIT and the U2-304 interceptor system cannot be locked due to lease restrictions. The building at the NIT is locked. All off-Base manholes are locked (Himle, C. 2003).

Environmental MonitoringThe ROD requires a program of long-term monitoring for contaminants and treatment system performance. A Performance Standard Verification Plan (CH2M 2001) was completed in 2001, describing the data needed to assess whether the remedial actions specified in the ROD are operating properly and successfully, and establishing a program to collect the data. The PSVP specifies annual reporting of operations and maintenance activities for the treatment systems, the annual cost of O&M, and an annual groundwater sampling report. The annual groundwater sampling report is a summary of the groundwater sampling conducted during the previous year, and includes data reporting and charting; it does not, however, include data interpretation. Thorough interpretation and evaluation of the data is deferred until 2006, when a Performance Standard Verification Report is scheduled. All environmental monitoring data, derived from either the O&M or groundwater sampling reporting, are submitted to ERPIMS.


The estimate of initial free-phase DNAPL accumulation in the G-Pool, outside of the containment wall, has been refined from 5,000-10,000 gallons (1998) to 2,800 gallons (currently). Approximately 2,500 gallons have been recovered from the G-Pool.

Many incremental improvements have been and continue to be achieved in the operation of the remedies.


Question A (Answer)

No


Some portions of the remedy appear to be functioning as intended, but others do not, as described below.

Containment wall: no.Groundwater elevation data through April 2001 suggest that an inward gradient is not maintained along a portion of the western segment of the wall which includes the piezometer nest consisting of U2-645, U2-646, and U2-647, and the nest consisting of U2-






648, U2-649, and U2-650. A slight outward gradient occurs in this area, indicating the potential for outward contaminant migration. The (visually assessed) trend of these piezometer data, however, suggests that groundwater elevations inside the wall continue to decline in response to extraction, at least in the zone(s) in which the piezometers are screened; if the trend continues, an inward gradient may eventually be achieved. Future measurements are needed to make this determination. Separate, though related, issues are 1) whether the nested piezometers are screened in hydraulically comparable intervals; and 2) whether exterior piezometers are affected by the UCS. As a group, the nest piezometers inside the wall show a steady decline in groundwater elevation relative to the exterior piezometers, suggesting dewatering inside of the wall. The data also indicate that the groundwater elevation outside of the eastern segment of the wall is kept below 4665 feet amsl, as desired.

Source recovery system, process plant: yes.Operating data suggest that the SRS process plant effectively separates DNAPL from contaminated groundwater and other fluids extracted from the source, and also effectively treats contaminated water generated by the separation process. Approximately 1,259 gallons of DNAPL were extracted from the source area and recovered by the SRS in 2001; the cumulative total recovered is approximately 43,500 gallons. Steam stripping during 2001 reduced the TCE concentration of contaminated groundwater from an average of 549 ppm to an average 3 ppm, consistently meeting the IWTP influent limit of 16 ppm and maintaining a removal efficiency above 98%. The total VOC influent limit to the IWTP of 25 ppm was not exceeded during 2001.

Source recovery system, extraction wells: no.Although contaminated groundwater is extracted from the shallow aquifer within the containment wall, groundwater elevations in the extraction wells increased over a period of 5 to 6 months during 2001, and exceeded the action level of 4660 feet amsl for most of the year even though the extraction wells were operated until water yield ceased. Therefore, the proper function of the SRS extraction well remedy cannot be determined until the PSVP action level is reviewed.

Treatability studies and innovative treatments: yes.SRS operating data indicate that approximately 6,000 gallons (cumulative) of DNAPL have been recovered from the source area as the result of activities associated with treatability studies and subsequent innovative treatments.

Air Stripper Treatment Plant: yes.During 2001, the ASTP treated approximately 10.5 million gallons of water from the NIT and UCS with removal efficiencies above 99.9% and consistently met the CWSID influent limit of 2.13 ppm total VOCs. The total mass of TCE removed in 2001 from the ASTP was 10.3 lbs.

North Interceptor Trench: no.A recent and preliminary evaluation (URS 2003) of historical groundwater elevation data form U2-079, U2-080, U2-675, and U2-676 suggest that during the spring portions of the NIT may fail to intercept groundwater flow. In addition, a review of recent TCE concentration data suggests the possibility of increasing TCE concentrations in





groundwater samples from U2-675, downgradient of the NIT. Together, these indicate the potential failure of portions of the NIT to intercept contaminated groundwater, at least during certain times of the year. In addition, the latest interpretation of the off-Base groundwater plume (see Figure OU2-1) suggests the NIT does not intercept the entire width of the plume.

Spring U2-326 Interceptor Trench: yes.Historical TCE concentration data from U2-326 indicate that the U2-326 interceptor trench successfully intercepts shallow contaminated groundwater. However, the trench sump is typically dry except during the spring.

Spring U2-304 Interceptor System: yes.Historical TCE concentration data from U2-304 indicate that the U2-304 interceptor trench successfully intercepts shallow contaminated groundwater. However, the spring has been dry in recent years.

Institutional Controls: yes.The institutional controls as implemented appear to be effective. However, The leading edge of the plume is very near the southern boundary of NE ¼, Sect. 29, T5N R1W, which is not subject to water rights restrictions imposed by Hill AFB in conjunction with the Utah Department of Natural Resources. Should the plume advance, it could impinge on this quarter section.

Environmental Monitoring: To be determined.The long-term environmental monitoring data are not due to be evaluated until 2006.

Question B (Answer)

No

Question B (Comment) Cleanup levels, listed in the OU 2 ROD (1996), of 1,1,1-trichloroethane, cis-1,2-

dichlorethene, lindane, tetrachloroethene, toluene, and trichloroethene for groundwater and surface water are based on the drinking water standard, are still valid (Utah Rule R309-103, MCLs, July 2002). The cleanup levels of Beta-BHC and methylene chloride for groundwater and surface water, and of tetrachloroethene and trichloroethene for soil are based on risk to human health. The risk factors, specifically the cancer slope factors, used to develop the cleanup levels for OU 2 are now 10-times to 10,000-times more stringent (EPA Region III 2002; URS 2002c).

The corrective action management unit (CAMU) rule was revised in 2002. The revised CAMU rule applies to the CAMU which includes Chemical Pit 3 within the boundary of the CAMU defined for OU 2. The CAMU is defined in the OU 2 ROD (CH2M 1996) as "the Source Area and area immediately adjacent needed for construction". Soils from construction were specified in the ROD for use as a grading layer to establish proper slope for the surface cap within the CAMU. The CAMU was designated for OU 2 based on the 1993 CAMU rule applicable at the time of the signing of the ROD. Because no changes to the scope of the CAMU have been made at OU 2, the action of creating a CAMU for





purposes specified in the OU 2 ROD is in compliance with the revised CAMU rule.

The baseline risk assessment (Radian, 1992b) considered the inhalation of indoor air in conjunction with showering as a potentially significant current and future pathway for both onsite and offsite residential exposure. However, no indoor air sampling was performed during the remedial investigation (Radian, 1992a), perhaps because the off-site land use at the time was predominantly agricultural. Since then, EMR, EPA, and Utah DEQ have jointly established a new action level for TCE concentration in indoor air of 0.43 ppbv. In addition, new homes have been built and new subdivisions developed in formerly agricultural areas downgradient of the source (Himle, C. 2003). A map showing the relationship between the new subdivisions and the off-Base plume had not been developed at the time of this review. The new indoor action level for TCE, combined with the increasing residential use downgradient of the source, raises the potential for indoor air quality issues that have not been addressed. This possibility should be investigated by updating maps showing the relationship between new residential development and the groundwater contamination plume.

Question C (Answer)

Yes


In 1997, after construction of the containment wall, an accumulation of mobile-phase DNAPL was discovered outside of the containment wall during a treatability study. This accumulation, the “G-Pool,” was adjacent to the northeast corner of the containment wall and contained an estimated 2,800 gallons of DNAPL. (Note: The 1998 FYR indicated an estimated 5,000 to 10,000 gallons in the G-Pool, made without the benefit of subsequent characterization and treatability studies.) Approximately 2,500 gallons of DNAPL have been recovered from the G-Pool, and small volumes of free-phase DNAPL continue to be recovered. To prevent the G-Pool from acting as a continuing source of dissolved-phase contamination, groundwater is maintained by extraction at an elevation less than 4460, the elevation of a saddle east of the pool in the topography of the Alpine Formation. Although hydraulic control is effective, the G-Pool is a source of contamination outside of the containment wall, so the wall does not control contaminant flux out of the G-Pool.

A large body of data exists for WP007. A check of these data indicates that they sometimes appear to support multiple, and conflicting, interpretations (e.g., dewatering interior to the containment wall). In other cases a remedy may be seasonally ineffective (e.g., at least one portion of the NIT does not appear to intercept groundwater during the spring months). There has not been a comprehensive study of the remedies, however, since remedial action began in 1993 with the startup of the SRS. Given the high level of investment, such a review is warranted. The mechanical systems (the SRS, ASTP, and associated liquid conveyance systems) appear to be functioning as designed.

A recent review of time-series data (URS 2003) of TCE concentration in U2-675 raises the possibility of increasing contaminant concentrations in groundwater downgradient of the NIT. The review is preliminary, but reinforces the need for an interim evaluation, before the PSVR in 2006, of the remedies addressing contamination stemming from WP007.





VIII. Issues 1. A joint evaluation of the SRS and the containment wall is ongoing. Protectiveness provided by these remedies cannot be determined until the data have been thoroughly evaluated and interpreted.

2. The proper function of the SRS extraction well remedy cannot be determined because the action level stated in the PSVP does not correspond to the water level elevation that can be achieved within the containment wall with maximum pumping of these wells. No rationale for this action level is given in the PSVP.

3. A preliminary evaluation of groundwater elevation and TCE concentration data from wells in the vicinity of the NIT suggest the possibility that during the spring months the NIT fails to intercept contaminated groundwater. Also, based on the latest interpretation of the off-Base plume (see Figure OU2-1), the NIT does not intercept the entire width of the plume.

4. The data collected by the LTM contractor are not readily available to the O&M contractor, though they may have a bearing on the operation of the remedies.

5. Since the baseline risk assessment (Radian 1992b), EMR, EPA, and Utah DEQ have jointly established a new action level for TCE concentration in indoor air of 0.43 ppbv. In addition, new homes have been built and new subdivisions developed in formerly agricultural areas downgradient of the source.

6. The leading edge of the plume is very near the southern boundary of NE ¼, Sect. 29, T5N R1W, which is not subject to water rights restrictions imposed by Hill AFB in conjunction with the Utah Department of Natural Resources (HAFB 1998). Should the plume advance, it could impinge on this quarter section.

7. A thorough review of several portions of the remedial systems addressing contamination at OU 2 may be justified sooner than the PSVR scheduled in 2006 because they have been in operation since 1993.

IX. Recommendations 1. Jointly evaluate the effectiveness of the SRS and the containment wall.

2. Identify the appropriate action level for well field operations and document new level and rationale in the PSVP.

3. Water level and analytical data in the vicinity of the NIT, the performance of the NIT, and the location of the NIT with respect to the dissolved-phase plume should be thoroughly evaluated.

4. Expedite submittal of LTM data to ERPIMS for timely review of remedy effectiveness.

5. Continue use of the portable DNAPL pump assembly to remove free-phase DNAPL from wells. Consider purchase of a second system, which would enable simultaneous recovery of DNAPL from two separate wells.






2008

6. Investigate the relationship between new residential development and the plume.

7. Re-evaluate the risk analysis for OU 2 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors as explained in the Technical Assessment above.

8. Consider the need to restrict water rights in the northeast quarter of Sect. 29, T5N R1W.

9. Evaluate whether a thorough review of the remedies at OU 2 can be performed before 2006.



A protectiveness determination of the remedies associated with WP007 cannot be made until further information is available. Within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at the site. Therefore, a re-evaluation of potential risk at WP007 must be conducted before the protectiveness of the current remedies can be determined.

The remedies specified by the ROD and now in-place constitute an appropriate response to contamination resulting from WP007 if operating as designed. A comprehensive evaluation of relevant data generated since remediation began is needed, however, in order to make a strong protectiveness statement by comparing operating data against design objectives. An assessment of the joint performance of the containment wall and the SRS, in operation together since 1996 is needed to make a clear statement about the prevention of continuing downgradient groundwater stemming from the source area. This assessment, along with a completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at WP007 during the next Five-Year Review (2008).




OU 2 SS021 PERIMETER ROAD


III. Background SS021 (Perimeter Road) was reportedly the site of previously unidentified dumping of waste solvents prior to 1979, in addition to dumping known to have occurred at a number of sites now associated with other Operable Units. A soil gas investigation conducted in 1998 along the entire length of SS021 concluded that dumping of solvents occurred only at sites now associated with other Operable Units; employees who conducted the dumping operations prior to 1979 confirmed this conclusion.

A Final Decision Document (HAFB EMR 1991a) states that no further response is required at SS021. The Record of Decision for Operable Unit 2 (CH2M 1996) states that SS021 has been found to be free of contamination except in those areas being addressed as part of existing Operable Units, and that no further action is needed.


None. No further action is needed at this site.


The Record of Decision for Operable Unit 2 determined that no further action is needed at this site. SS021 was not reviewed in the 1998 Five-Year Review.


Question A (Answer)

Not Applicable


No further action is needed at this site.



I. Introduction SS021, also known as Perimeter Road, is located along the northeastern boundary of Hill AFB. No remedial action is required at this site; it is included in the 2003 Five-Year Review for completeness.




* None




OU 2 SS021 PERIMETER ROAD



Question B (Answer)

Not Applicable



Question C (Answer)

Not Applicable



VIII. Issues None. No further action is needed at this site.

IX. Recommendations None.



The Perimeter Road site (SS021) was recommended for NFRAP status in 1991 because the site has been found to be free of contamination except in those areas being addressed as part of existing Operable Units.




Operable Unit 3

I Introduction

OU 3 is a soils-only OU that consists of five IRP sites, including the Sodium Hydroxide Tank Site, Berman Pond, the IWTP Sludge Drying Beds, Building 514 [Refueling Vehicle Maintenance Facility (RVMF)], and Pond 2 (see Table OU 3-1). The IWTP Sludge Drying Beds, Building 514, and Pond 2 are closed sites with no further remedial action planned. The remedial actions at the Sodium Hydroxide Spill Site and Berman Pond are inspected and maintained annually. Groundwater contamination below OU 3 is addressed as part of OU 8.


Site ID Site Name ST004 SODIUM HYDROXIDE TANK SITE WP005 BERMAN POND WP006 IWTP SLUDGE DRYING BEDS ST018 BUILDING 514 SD046 POND 2

II Site Chronology


III Background

OU 3 is located near the South Gate Entrance at Hill AFB and includes two open IRP sites (Sodium Hydroxide Tank Site and Berman Pond), and three closed IRP sites (IWTP Sludge Drying Beds, Building 514, and Pond 2). The location of each IRP site is illustrated in Figure OU 3-1. The list of contaminants of concern for Berman Pond are included in the Site Summary (Section XIII) for Site WP005. The remedial actions for the two open sites are cap installation, cap maintenance, and institutional controls. Contaminated soils from these two sites have been capped with an asphalt cover to minimize infiltration. Performance indicators for these two sites include increased contaminant concentrations observed in monitoring wells (MWs) upgradient and/or downgradient of these sites, which may indicate that groundwater is in contact with the contaminated soils and migrating off-site. The other three IRP sites were either closed following remedial action success (ST018) or after the RI indicated that no contamination was evident (SD046 and WP006). Two additional sites were originally investigated as part of OU 3 [Pond 1 (SD034) and Pond 3 (SD023)]. These sites were closed under OU 3, but have been reopened and are undergoing further investigation as part of OU 9.

IV Remedial Actions No remedial actions were implemented at the IWTP Sludge Drying Beds or Pond 2. Remedial actions that have been implemented at OU 3 to address soil contamination are listed below:


ST018 – Building 514 1. In-Situ Vapor Extraction An SVE system was installed to reduce the concentrations of 1,1-DCE in the soil to 0.8

mg/kg. The SVE system consisted of a concrete pad foundation and security fence, a 15-foot deep SVE well inside Building 514, two trenches (one from the new SVE well and another from an existing well outside Building 514) leading to the SVE system pad (MW 1996). The remedy was successful and closure was therefore approved on May 2001.

2. Institutional Controls Institutional controls consisted of fence installation with warning signs to restrict access to

the treatment facility and implementation of the continuing order to restrict access (HAFB 1998).

ST004 – Sodium Hydroxide Tank Site 1. Cap Installation and Maintenance

In 1992, a cap was constructed at the ground surface after the tanks were removed and the area backfilled in 1992 (HAFB EMR 1992a). An area of approximately 29,000 square feet was capped to cover the apparent lateral extent of the NaOH plume in the soil beneath the tanks. The tank removal project was administered by UDERR via its Underground Storage Tank (UST) rules. An annual cap inspection program is ongoing at the permanent remedy.

2. Institutional Controls

The institutional controls specified in the ROD include a continuing order from the Installation Commander and covenants to the deed (HAFB 1998), which will be in effect as long as the property is owned by the Air Force. The continuing order restricts installation of any new underground utilities or other construction activities in the area of the cap and requires that the integrity of the cap is maintained.

WP005 – Berman Pond 1. Cap Installation and Maintenance Prior to the cap installation, the water in the former pond was extracted to the extent possible.

The selected capping system is designed to meet the regulatory permeability requirement of 1x10-7 cm/sec. The cap reduces the potential for exposure to the contaminated soils and minimizes seepage through the soils to groundwater thereby protecting groundwater quality. Perched water elevations measured in four sumps located within the asphalt cap are measured to ensure that they do not exceed the prescribed elevation action levels (CH2M 2001). If the perched groundwater levels exceed the prescribed elevation action level, pumps should be installed in the extraction sumps.

2. Institutional Controls Institutional controls include a provision for long-term maintenance of the cap and

development of standard operating procedures (SOPs) to ensure effectiveness, posting of signs warning of subsurface contaminated soil in the area, and a continuing order from the Installation Commander (HAFB 1998). The continuing order restricts access to contaminated soils as long as Hill AFB owns the property.



The sites included in the 1998 Five-Year Review (HAFB EMR 1998) were ST004, WP005, and ST018. All of the recommendations that were included in the 1998 Five-Year Review have been addressed except for institutional controls, such as signage and painted delineations, at Berman Pond and the Sodium Hydroxide Tank Site.


Site review was conducted per the process described in this report for the overall 2003 FYR. VII Technical Assessment

Results of the technical assessment for each site in OU 3 and for the Operable Unit as a whole are listed in Table OU 3-3. Details of the technical assessment for each site in OU 3 are provided in their respective site summaries (see Section XIII).

Table OU 3-3. Technical Assessment Summary for OU 3



Next Five-Year

Review

ST004 Cap Maintenance and Institutional Controls Yes Yes Yes Protective 2008

WP005 Cap Maintenance and Institutional Controls Yes No No Protective 2008

WP006 NA NA NA NA NA NA

ST018 In-Situ Vapor Extraction and

Institutional Controls Yes Yes No Protective NA

SD046 NA NA NA NA NA NA

OU 3 Cap Maintenance and Institutional Controls Yes No Yes Protective 2008

* Question A: Is the remedy functioning as intended by the decision documents? Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs)

used at the time of the remedy still valid? Question C: Has any other information come to light that could call into question the protectiveness of the

remedy? NA = Not Applicable

Question A. Is the remedy functioning as intended by the decision documents? ST004 – Sodium Hydroxide Tank Site Yes. Performance indices (CH2M 2001) include significant increases in groundwater pH or in concentrations of TDS, sodium, arsenic, or selenium downgradient of the original tank location. No significant increases are evident for any of these parameters over the eight-year period since August 1996.


WP005 – Berman Pond Yes. During a cap inspection in August of 2002, the cap was found to be performing as designed. Permeability tests ranged from 38 to 78 mL/min. Groundwater levels at the extraction sumps at Berman Pond show that the elevations are approximately 10 feet above the action level prescribed in the PSVP (CH2M 2001) and have been since 1998. Pumps have not been installed in the groundwater extraction sumps, as prescribed in the ROD (HAFB EMR 1995). According to the interviews conducted as part of this review, Hill EMR believes that the OU 8 interim remedial action (extraction wells) is capturing the elevated perched contaminated groundwater from OU 3 (Watkins, J. 2002). ST018 – Building 514 Yes. The SVE remedial action decreased the soil contamination of 1,1-DCE to below detectable concentrations (0.005 mg/kg) in all of the samples collected from the confirmation soil borings. The goal of the remedy was to decrease the concentrations of 1,1-DCE to less than 0.8 mg/kg. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid?

ST004 – Sodium Hydroxide Tank Site Yes. The arsenic cleanup level is currently valid. However, it should be noted that the revised arsenic standard of 10 ug/L (ppb) will be effective in 01/26/2006. WP005 – Berman Pond No. The inhalation cancer slope factor (CSF) for methylene chloride has increased from 1.65x10-6 to 1.65x10-3 (mg/kg/d)-1 (1,000 times more stringent) at OU 2 and OU 3 (EPA Region III 2002). There was no MCL available for 1,1,2,2-tetrachloroethane for the risk analysis in the ROD, so a toxicity factor was not listed for comparison. However, there was a change for this compound in the EPA Region 3 RBC Table in Oct 1998. ST018 – Building 514 Yes. The 1,1-DCE MCL of 0.8 mg/kg is still valid.

Question C: Has any other information come to light that could call into question the protectiveness of the remedy?

ST004 – Sodium Hydroxide Tank Site

Yes. It was noted in the annual inspection report (URS 2002a) that several roll-off bins had been stored to the south of Building 577 for some time. Subsequently, an inspection of the asphalt on August 12, 2001 revealed a number of depressions in the asphalt, which were recommended for repair. WP005 – Berman Pond No. No additional information has come to light that could call into question the protectiveness of the remedy. ST018 – Building 514 No. No additional information has come to light that could call into question the protectiveness of the remedy.


VIII Issues

Based on the information reviewed, issues that may affect protectiveness of the selected remedies at OU 3 are: ST004 – Sodium Hydroxide Tank Site 1. Storage of heavy equipment (roll-off bins) on the asphalt cap at ST004 may jeopardize the

integrity of the cap (URS 2002). Warning signs have been made but have not been installed to date.

WP005 – Berman Pond 2. Pumps were initially installed five years ago to pump the perched water level down as far as

possible and then removed when the asphalt cap was installed. However, the groundwater levels in the extraction sumps at Berman Pond have been above the elevation actions level set in the PSVP (CH2M 2001) for the past four years. The ROD (HAFB EMR 1995) states that when the perched groundwater elevations exceed the action level, pumps should be installed and a pumping strategy, sampling and analysis plan, and continued groundwater level monitoring should be implemented. These activities have not been conducted to date because EMR staff believe the OU 8 interim remedial action (extraction wells) is capturing any contaminated groundwater originating from Berman Pond.

3. Warning signs and painted delineations of the asphalt cap (as recommended by the 1998

Five-Year Review) have not been installed to date. 4. Recommendations made by the site inspector on September 2002 (Vicelja, J. 2002) have not

been addressed to date. These recommendations included slurry sealing the asphalt cap in the fall of 2002 and changing the landscape-watering scheme to reduce ponding on the cap surface.


The recommendations and follow-up actions for OU 3 are: 1. If future work compromises the integrity of the remedies at OU 3, the risk analysis for the

active sites should be re-evaluated to determine if revised contaminant action levels are warranted based on new standards and toxicity factors as explained in the Technical Assessment above.

ST004 – Sodium Hydroxide Tank Site 2. Continue inspection and monitoring program for the cap. 3. Patch any damaged areas of the cap in the areas where the roll-off bins were located. 4. Continue with the current groundwater-monitoring plan. 5. Add painted delineations to the perimeter of the asphalt cap. 6. Post warning signs prohibiting storage of equipment and excavation without permission. 7. Develop procedures for excavation and equipment storage to minimize defects in the asphalt

cap.


WP005 – Berman Pond 8. The PSVP should be revised to document the change of remedial actions at the site (the

groundwater contamination from Berman Pond is captured by the OU 8 interim remedial action and therefore the pumping action level is not required).

9. Change the watering scheme for the landscaping around the asphalt cap at Berman Pond according to the recommendations made following the September 2002 cap inspection (Vicelja, J. 2002).

10. Slurry seal the asphalt cap in the summer of 2003 to prevent excess infiltration according to recommendations made following the September 2002 cap inspection (Vicelja 2002).

11. Post warning signs prohibiting storage of equipment and excavation without permission. 12. Add painted delineations to the perimeter of the asphalt cap.

X Protectiveness Statement for OU 3 The remedies associated with OU 3 are protective of human health and the environment. However, within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 3. Therefore, if future work at OU 3 compromises the integrity of the remedies, a re-evaluation of potential risk must be conducted to determine if revised contaminant action levels are warranted based on new standards and toxicity factors. Additional items that need to be addressed are described in the previous issues and recommendations and include revision of the PSVP to document the change of remedial action at the site. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 3 during the next Five-Year Review (2008).

XI Next Review The next FYR for OU 3 is required by 2008. No future review is required for the IWTP Sludge Drying Beds, Building 514, or Pond 2 sites because no further remedial actions are required at these sites.


(CH2M 2001) Performance Standard Verification Plan Operable Unit 3, CH2M Hill, November 2001. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1992b) U.S. Air Force Installation Restoration Program Remedial Investigation / Feasibility Study Hill AFB, Utah, Decision Paper Site SD046 - Storm Pond 2 No Further Response Action Planned., Hill AFB EMR, 30 June 1992. (HAFB EMR 1992a) Record of Decision for Interim Action at Operable Unit 3 Site ST04, Hill AFB EMR, September 1992.


(HAFB EMR 1995) Record of Decision for Operable Unit 3, Hill AFB EMR, September 1995. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (MW 1996) 100 Percent Technical Specifications - SVE System Remedial Design Operable Unit 3, Montgomery Watson, September 1996. (MW 1999a) Remedial Action Project Close-Out Report for Operable Unit 3, Montgomery Watson, April 1999. (MW 1999b) Annual Report for Operable Unit 3 Sodium Hydroxide Tank Site and Berman Pond, December 1999, Montgomery Watson, December 1999. (URS 2001) Statement of Concurrence With No Further Response Action Planned (NFRAP), Building 514 Refueling Vehicle Maintenance Facility (RVMF), Installation Restoration Program (IRP) Site ST018, URS Greiner, Inc., May 2001. (URS 2002) 2001 Operation and Maintenance Reports OU 3 Sodium Hydroxide Tank Site Cap and Berman Pond Cap, OU 4 Landfill 1 Cap and Soil Vapor Extraction Drain System, and OU 7 Building 225 Floor Slab, Hill Air Force Base, Utah, URS, March 2002. (Vicelja, J. 2003) Consulting Engineer, P.E., Joseph Vicelja Consulting Engineering, Personal Communication, 07 February 2003. (Watkins, J. 2002) EM Operations Program Manager, Hill AFB EMR, Personal Communication, 24 October 2002.



OU 3 OPERABLE UNIT 31993 Contaminated groundwater

designated as OU 8Due to multiple sources of groundwater contamination, the contaminated groundwater underlying the South Area was designated as OU 8.

Performance Standard Verification Plan Operable Unit 3

1995 Remedial Investigation The Remedial Investigation was submitted to EMR in 1995. The Baseline Risk Assessment was included in this submission.

Remedial Investigation Report for Operable Unit 3 (IRP Sites ST04, WP05, WP06, ST18, SD23, OT33, SD34, and SD46), Draft Final

1995 Feasibility Study The Final Feasibility Study was submitted to EMR in 1995. Results concluded that no remedial action was required for the IWTP Sludge Drying Beds.

Feasibility Study for Operable Unit 3 (IRP Sites ST04, WP05, WP06, ST18, SD23, SD34)

09 1995 Record of Decision The selected remedy called for SVE at Site ST018, a cap at Berman Pond (WP005), and cap maintenance at Site ST004. The ROD also closed the IWTP Sludge Drying Beds.


01 1997 Transfer of Pond 1 from OU 3 to OU 9

Pond 1 had previously been included in OU 3. The ROD for OU 3 (in 1995) concluded that cleanup actions at Pond 1 were not necessary. The investigation of Pond 1 was reopened under OU 9 as a result of contamination detected in the storm water system at Berman Pond.

Engineering Evaluation/Cost Analysis for the OU9 Pond 1 Removal Action, Final Report





09 1999 Transfer of Pond 3 from OU 3 to OU 9

Pond 3 had previously been included in OU 3. The ROD for OU 3 (in 1995) concluded that cleanup actions at Pond 3 were not necessary. The investigation of Pond 3 was reopened under OU 9 following discovery of contamination at the inlet of Pond 1.

Final Data Summary Report and Preliminary Conceptual Model for Operable Unit 9 Investigation Areas

ST004 SODIUM HYDROXIDE TANK SITE1950 Construction The construction of two storage tanks for sodium hydroxide

(NaOH).Record of Decision for Interim Action at Operable Unit 3 Site ST04

1980 NaOH Spill Approximately 150,000 gallons of NaOH leaked from tanks in one year period.


04 1984 NaOH Spill An additional 134,000 gallons leaked from April to June in 1984. The concentration of NaOH was 25 percent by weight.


09 1992 NaOH tanks removed Both 12,000 gallons tanks were removed in accordance with UDEQ.






08 1993 Remedial Action An asphalt surface covering was installed over the area. Record of Decision for Interim Action at Operable Unit 3 Site ST04

1999 Additonal cap construction The interim remedial cap was covered with a permanent remedial asphalt layer.


WP005 BERMAN POND1940 Operation From 1940 to 1956, Berman Pond (WP005) was operated as

an unlined evaporation pond that received storm water runoff and industrial wastewater, which may have included spent solvents, heavy metals, and hydrocarbons.


1956 Operation Prior to 1956, Berman Pond was connected to Pond 1 (see Figure OU 3-1), which received overflow from Berman Pond during high intensity storms. After construction of the lWTP in 1956, Berman Pond was connected to a sanitary sewer line and was used only as a storm water retention pond.


1958 Operation In 1958, pond overflow was re-routed to the storm drainage system, and between 1958 and 1970, the pond was filled with construction rubble and soils, and regraded.






1984 A soil cap was installed over a portion of the pond

The cap was not effective in reducing infiltration Hill AFB Environmental Restoration Management Action Plan - 2001

1986 Remedial Action A cap, consisting of silt and clay, was installed over a portion of the pond.


1994 Treatabilty Study Dewatering treatability study completed. The pond was dewatered for the installation of the cap.


1997 Remedial Action An asphalt cap was installed over the entire pond to reduce infiltration.


WP006 IWTP SLUDGE DRYING BEDS1956 Waste disposal started Beginning in 1956, sludge from the clarifier was pumped to

two sludge drying bed areas south of the treatment facility. The sludge material was composed of paint stripping, chrome plating, and degreasing wastes and was stored in the sludge beds to dry.






1985 Remedial Investigation RI at the IWTP initiated. Based on the findings, the IWTP Sludge Drying Beds did not pose any current or future health risks or present a threat to groundwater

Remedial Design Report and Work Plan for Operable Unit 3

1987 Sludge dewatering facilty started In June 1987, a sludge dewatering facility was put into operation to dewater IWTP sludge with a filter press and dryers. The sludge drying beds are still used for temporary storage before running the sludge through the dryers.


1995 NFRAP Accepted for NFRAP status in the ROD Record of Decision for Operable Unit 3

ST018 BUILDING 5141985 Operation Through 1985, drained fuels were collected in a floor drain at

the RVMF, passed through an oil/water separator, and either disposed of or recycled. Collected water was stored in a small underground storage tank (UST) and subsequently pumped to the IWTP for treatment.


10 1997 SVE System Installed at RVMF An SVE system was installed at Bldg. 514 and began operation on October 10, 1997. The system was operated for approximately one year.

Remedial Action Project Close-Out Report for Operable Unit 3





05 2001 NFRAP The site was recommended for NFRAP status and was accepted due to the success of the SVE.

Statement of Concurrence With No Further Response Action Planned (NFRAP), Building 514 Refueling Vehicle Maintenance Facility (RVMF), Installation Restoration Program (IRP) Site ST018

SD046 POND 21974 Operation Pond 2 was an ephemeral stormwater pond that received

occasional excess surface runoff from Hill AFB until 1974. At that time, the storm drain was rerouted to Pond 3.

U.S. Air Force Installation Restoration Program Remedial Investigation/Feasibilty Study Hill AFB, Utah, Decision Paper Site SD046 - Storm Pond 2 No Further Response Action Planned.

1991 Sold to private entity The site was closed with a decision document in 1992 and sold off-Base to a private entity in 1991

U.S. Air Force Installation Restoration Program Remedial Investigation/Feasibilty Study Hill AFB, Utah, Decision Paper Site SD046 - Storm Pond 2 No Further Response Action Planned.




OU 3 ST004 SODIUM HYDROXIDE TANK SITE


III. Background ST004 is located in the southeast quadrant of Hill AFB in an industrial area used to service and maintain aircraft. ST004 is north of the 419th Fighter Wing hanger (see to Figure OU 3-1). ST004 is the former location of two 12,000-gallon USTs that were used to store 25% by weight solution of NaOH. During the period that the tanks were used, several hundred thousand gallons of solution were lost due to leakage. Both tanks were removed in 1992 in accordance with UDEQ requirements. An asphalt cap was installed in 1993 as an interim action and covers approximately 29,000 square feet (see Figure OU 3-1). Elevated levels of soil pH (resulting from the release of sodium hydroxide solution) were present in subsurface soil; soil pH ranged from 6.2 to 12.9 pH units. Several metals also were detected above background levels, including cadmium and total chromium. Based on the findings and conclusions of the OU 3 RI/FS and the risk assessments, only soils with high pH required remedial action. The area of soil impacted by the sodium hydroxide solution is approximately 70 feet deep and 170 feet wide. The zone of highest pH appears to be located between 25 and 40 feet bgs.


Cap Installation and MaintenanceIn 1992, a cap was constructed at the ground surface after the tanks were removed and the area backfilled in 1992 (HAFB EMR 1992a). An area of approximately 29,000 square feet (170 feet by 170 feet) was capped to cover the apparent lateral extent of the NaOH plume in the soil beneath the tanks. The tank removal project was administered by UDERR via its Underground Storage Tank (UST) rules. All related UST activities were conducted pursuant to a permit issued by UDERR. An annual cap inspection program is ongoing at the now permanent remedy.


I. Introduction ST004 is the former location of two 12,000-gallon USTs that were used to store sodium hydroxide solution. Several large spills occurred at the site which contaminated the soils with high pH solution. As part of interim remedial actions, an asphalt cap was constructed in 1993 to prevent exposure to high pH soils. Several groundwater monitoring wells are sampled for arsenic, TDS, selenium, sodium, and pH. The upgradient and downgradient concentrations of selenium, sodium, TDS, pH, and arsenic have remained steady over the past eight years.



NA NA NA

* Reduce contaminant transport from within source areas and reduce chemical transport from soil to ground water by minimizing surface water infiltration.* Prevent human exposure to contaminated soil through ingestion, inhalation, and dermal contact, so that the individual excess cancer risk is below 1E -4 with a target of 1E-6, and the threshold non-cancer hazard index is less than 1.0.





Institutional ControlsThe institutional controls specified in the ROD include a continuing order from the Installation Commander and covenants to the deed, which will be in effect as long as the property is owned by the Air Force (HAFB 1998). The continuing order restricts installation of any new underground utilities or other construction activities in the area of the cap, provides for the use of proper protective equipment in the event that access through the cap is required, and requires that the integrity of the cap is maintained (i.e., repair cracks that may develop) so that fluids cannot infiltrate to the subsurface.


Recommendations for this site in the 1998 Five-Year Review (HAFB EMR 1998) included paving the entire site with asphalt (permanent remedial action, completed in 1999) and continuing the yearly cap inspection. A database and geographic information service (GIS) system was being developed, at the time of the review, to track the long term operation and maintenance of this remedial action. Currently this information is being captured by ERPIMS.


Question A (Answer)

Yes


Performance indices (CH2M 2001) include a significant rise in groundwater pH or an increase in concentrations of TDS or sodium, increased concentrations of arsenic or selenium, downgradient of the original tank location [U3-029R and U9-002, please refer to the Annual Report for Operable Unit 3 Sodium Hydroxide Tank Site and Berman Pond (MW 1999b) for the location of the two monitoring locations]. No significant increases are evident for any of these parameters over the eight year period since August 1996.

Question B (Answer)

Yes


The arsenic cleanup level is currently valid. However, it should be noted that the revised arsenic standard of 10 ug/L (ppb) will be effective in 01/26/2006.

The RAOs for the remedial actions at ST004 are still valid.

Question C (Answer)

Yes


It was noted in the annual inspection report (URS 2002a) that several roll-off bins had been stored to the south of Building 577 for some time. These bins were recently removed. Subsequently, an inspection of the asphalt on August 12, 2001 revealed a number of







2008

depressions in the asphalt which were recommended for repair. However, this repair had not been performed at the time of the site inspection for this review. Damage to the cap could jeopardize its integrity and allow infiltration.

VIII. Issues *Storage of heavy equipment on the asphalt cap may jeopardize the integrity of the cap. *Warning signs and painted delineations of the cap have not been installed to deter storage of this kind of equipment.

IX. Recommendations *Continue inspection and monitoring program for the cap.*Patch any damaged areas of the cap in the areas where the roll-off bins were located.*Continue with the current groundwater-monitoring plan*Add painted delineations to the perimeter of the asphalt cap.*Post warning signs prohibiting storage of equipment and excavation without permission.*Develop procedures for excavation and equipment storage to minimize defects in the asphalt cap.



The remedial actions at ST004 are protective of human heath and the environment based on steady upgradient and downgradient concentrations of selenium, sodium, TDS, pH, and arsenic over the past eight years. The asphalt cap is performing as designed but defects in the cap should be repaired as soon as they are discovered to ensure continuing protectiveness.




OU 3 WP005 BERMAN POND


III. Background From 1940 to 1956, Berman Pond (WP005) was operated as an unlined evaporation pond that received storm water runoff and industrial wastewater, which may have included spent solvents, heavy metals, and hydrocarbons. Prior to 1956, Berman Pond was connected to Pond 1 (see Figure OU 3-1), which received overflow from Berman Pond during high intensity storms. After construction of the IWTP in 1956, Berman Pond was connected to a sanitary sewer line and was used only as a storm water retention pond. In 1958, pond overflow was re-routed to the storm drainage system, and between 1958 and 1970, the pond was filled with construction rubble and soils, and regraded. Information obtained from aerial photographs indicates that the maximum dimensions of Berman Pond were approximately 800 feet long and 420 feet wide, and encompassed an area of approximately six acres. Berman Pond is located east of the South Gate of Hill AFB in an industrial area used for the servicing and maintaining aircraft. The area is flat, well-drained, and covered by industrial facilities, parking lots, and roadways. A cap, consisting of silt and clay, was installed over a portion of the pond in 1986. Construction of an asphalt cap was completed in July of 1998. Annual inspection and maintenance of the cap continues.


I. Introduction Berman Pond (WP005) was operated as an unlined evaporation pond that received storm water runoff and industrial wastewater. As part of interim remedial actions at Berman Pond, a cap consisting of silt and clay was installed over a portion of the pond in 1986. Construction of the asphalt cap was completed in July of 1998. Annual inspection and maintenance of the cap is ongoing as well as groundwater monitoring to determine if the perched water levels are below the action level set forth in the PSVP (CH2M 2001).



SOIL 1,1,2,2-TETRACHLOROETHANE 0.0001 mg/kg

SOIL 1,1,2-TRICHLOROETHANE 0.04 mg/kg




SOIL ARSENIC 4.1 mg/kg


SOIL BENZO(a)PYRENE 0.07 mg/kg

SOIL bis(2-ETHYLHEXYL) PHTHALATE 6 mg/kg






Cap Installation and MaintenancePrior to the cap installation, the water in the former pond was extracted to the extent possible. The selected capping system consists of a gravel subbase overlain by a two-inch layer of hydraulic asphalt and a two- to three-inch structural wearing course asphalt layer. The cap reduces the potential for exposure to the contaminated soils and minimizes seepage through the soils to groundwater thereby protecting groundwater quality. Perched water elevations measured in four groundwater extraction sumps located within the asphalt cap are measured to ensure that they do not exceed the prescribed elevation action levels (CH2M 2001). According to the ROD (HAFB EMR 1995), if the perched water levels exceed the prescribed elevation action level, pumps should be installed in the extraction sumps.

Institutional ControlsInstitutional controls include a provision for long-term maintenance of the cap and development of standard operating procedures to ensure it remains effective, posting of signs warning of subsurface contaminated soil in the area, and a continuing order from the Installation Commander (HAFB 1998). The continuing order restricts access to, or disturbance of, contaminated soils as long as Hill AFB owns the property.


Recommendations from the 1998 Five-Year Review (HAFB EMR 1998) included the installation of warning signs; verification that the asphalt cap is properly maintained; monitoring of the four settlement monitoring markers annually to detect any significant settlement that might affect cap integrity; and evaluation of the effectiveness of the asphalt cap and perched-water extraction system by monitoring both the water levels within the perched-water zone of Berman Pond and the COC concentrations in one existing upgradient monitoring well and two downgradient wells. All of the recommendations have been instituted except for institutional controls.


SOIL CADMIUM 16 mg/kg


SOIL HEPTACHLOR EPOXIDE 0.004 mg/kg

SOIL METHYLENE CHLORIDE 0.02 mg/kg


SOIL trans-1,2-DICHLOROETHENE 0.7 mg/kg



* Reduce contaminant transport from within source areas and reduce chemical transport from soil to groundwater by minimizing surface water infiltration.* Prevent human exposure to contaminated soil through ingestion, inhalation, and dermal contact, so that the individual cancer risk is below 1E–4, with a target of 1E-6, and the threshold non-cancer index is less than 1.0.






Question A (Answer)

Yes


During a cap inspection in August of 2002, the cap was found to be performing as designed. Permeability tests ranged from 38 to 78 mL/min which, according to the inspector, were very low. However, the inspector did suggest that the asphalt cap would need to be slurry sealed and that the landscape watering scheme should be changed to minimize ponding and infiltration. This repair had not been conducted at the time of the site inspection for this Five-Year Review.

Groundwater levels at the extraction sumps at Berman Pond show that the elevations are approximately 10 feet above the action level prescribed in the PSVP (CH2M 2001) and have been since 1998 [please refer to the Annual Report for Operable Unit 3 Sodium Hydroxide Tank Site and Berman Pond (MW 1999b) for the location of the four sump locations]. Pumps have not been installed in the groundwater extraction sumps, as prescribed in the ROD (HAFB EMR 1995). According to the interviews conducted as part of this review, Hill EMR believes that the OU 8 interim remedial action (extraction wells) is capturing the elevated perched contaminated groundwater from OU 3 (Watkins, J. 2002).

Question B (Answer)

No


The inhalation cancer slope factor (CSF) for methylene chloride has increased from 1.65E-6 to 0.00165 (1000x more stringent) (EPA Region III 2002).

The ingestion CSF for PCB-1254 decreased from 7.7 to 2.0 per (mg/kg/d) (less stringent), and the inhalation CSF for PCB-1254 is now available at 2.01 per (mg/kg/d) (EPA Region III 2002).

There was no MCL available for 1,1,2,2-tetrachloroethane for the risk analysis in the ROD, so a toxicity factor was not listed for comparison. However, there was a change for this compound in the EPA Region 3 RBC Table in Oct 1998. Risk may need to be reevaluated.

The RAOs are still valid for the selected remedy.

Question C (Answer)

No


Not applicable.






VIII. Issues *The groundwater levels in the extraction sumps at Berman Pond have been above the elevation actions level set in the PSVP (CH2M 2001) for the past four years. When the perched groundwater elevations exceed the action level, pumps should be installed and a pumping strategy, sampling and analysis plan, and continued groundwater level monitoring should be implemented. These activities have not been implemented to date. The interviews conducted as part of this review revealed that pumps have not been installed as per the PSVP because Hill EMR believe that the OU 8 groundwater plume is hydraulically connected to the groundwater at OU 3 and that the OU 8 remedial action (extraction wells) is capturing and treating the groundwater from Berman Pond.

*Warning signs and painted delineations of the asphalt cap have not been installed to date.

*Recommendations made by the site inspector on September 2002 (Vicelja, J. 2002) have not been addressed. These recommendations included slurry sealing the asphalt cap in the fall of 2002 and changing the landscape-watering scheme to reduce ponding on the cap surface.

IX. Recommendations *The PSVP should be revised to document the change of remedial actions at the site (the groundwater contamination from Berman Pond is captured by the OU 8 interim remedial action and therefore the pumping action level is not required).*Change the watering scheme for the landscaping around the asphalt cap at Berman Pond according to the recommendations made following the September 2002 cap inspection (Vicelja, J. 2002). *Slurry seal the asphalt cap in the summer of 2003 to prevent excess infiltration through the course layer of asphalt concrete to the hydraulic asphalt layer (which should not exceed a maximum permeability of 1E-7 cm/sec).*Post warning signs prohibiting storage of equipment and excavation without permission.*Add painted delineations to the perimeter of the asphalt cap.



Based on the findings of this review, the remedies associated with WP005 are protective of human health and the environment. However, within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 3. Therefore, if future work at OU 3 compromises the integrity of the remedies, a re-evaluation of potential risk must be conducted to determine if revised contaminant action levels are warranted based on new standards and toxicity factors.

Additional items that need to be addressed are described in the issues and recommendations sections and include revision of the PSVP to document the change of remedial action at the site. A completed PSVR, due in 2006, will be useful for determining the protectiveness of the remedial actions at OU 3 during the next Five-Year Review (2008).






2008




OU 3 WP006 IWTP SLUDGE DRYING BEDS


III. Background WP006 is located in the southeast quadrant of Hill AFB in an industrial area used for the servicing and maintaining aircraft, just north of the 419th fighter wing hangar (see Figure OU 3-1). Sludge from the IWTP consisted of paint stripping, chrome plating, and degreasing wastes. The drying bed areas were used until 1982 to store semi-solid sludges. The area underlain by the west beds currently is used for a parking area and a warehouse building. The east beds were backfilled to accommodate a 220,000-gallon aboveground wastewater storage tank.


Not applicable. There are no RAOs for this site.


WP006 was not included in the 1998 Five-Year Review.


Question A (Answer)

Not Applicable


There are no remedies associated with this site.



I. Introduction The IWTP began operating in 1956, and sludge from the clarifier was pumped to two sludge drying bed areas south of the facility. A remedial investigation at the IWTP Sludge Drying Beds (WP006) was initiated in 1985 to evaluate the potential for soil and groundwater contamination from past activities. However, the RI/FS and the risk assessments found contaminants in the subsurface soil below the former sludge drying beds were not a current or future health risk or a threat to groundwater. Consequently, cleanup actions were not necessary at the IWTP Sludge Drying Beds. This site was closed in the ROD (HAFB EMR 1995).




NA





OU 3 WP006 IWTP SLUDGE DRYING BEDS



Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.





WP006 was closed in the ROD in 1995 because contaminants in the subsurface soil below the former sludge drying beds did not pose current or future health risks or present a threat to groundwater.




OU 3 ST018 BUILDING 514


III. Background Through 1985, drained fuels were collected in a floor drain at the RVMF, passed through an oil/water separator, and either disposed of or recycled. Collected water was stored in a small underground storage tank (UST) and subsequently pumped to the IWTP for treatment. Building 514 is no longer used as a collection facility for fuel, and, since September 1988, it has been the Base’s Hazardous Waste Control Facility. Building 514 is located in the industrial portion of Hill AFB within the controlled area, which is fenced and access limited (see Figure OU 3-1).

Soil contamination (1,1-DCE) resulting from the activities that took place at the RVMF was remediated using in-situ soil vapor extraction. The SVE system was started on 10 October 1997 and operated for approximately one year when contaminant concentrations of 1,1-DCE in the extracted soil vapor had declined to levels that indicated that the system could be shut down. As confirmation, two soil borings (U3-932 and U3-933) located on the east and west sides of the extraction well, were sampled for VOCs. The results indicated that there were no detectable contaminant concentrations for 1,1-DCE. The RVMF site was recommended and accepted for NFRAP status in May 2001 (URS 2001).


In-Situ Vapor ExtractionAn in-situ soil vapor extraction (SVE) system was installed to reduce the concentrations of 1,1-DCE in the soil to 0.8 mg/kg. The SVE system consisted of a concrete pad foundation and security fence, a 15-foot deep SVE well inside Building 514, two trenches (one from the new SVE well and another from an existing well outside Building 514) leading to the SVE system pad (MW 1996). The remedy was successful and closure was therefore approved on May 2001.


I. Introduction From the late 1950s until 1985, the Refueling Vehicle Maintenance Facility (ST018) was used for draining excess fuel from refueling vehicles prior to their maintenance in Building 514 (see Figure OU 3-1). Soil contamination from activities at the RVMF was remediated by in-situ soil vapor extraction. ST018 initially included both Bldg. 511 and Bldg. 514, but the OU 3 Remedial Investigation found that concentrations of contaminants in soil borings near Bldg. 511 were within acceptable limits (HAFB EMR 1995). ST018 was granted No Further Remedial Action Planned status in 2001 (URS 2001).




* Prevent human exposure to the contaminated soils through ingestion, inhalation and dermal contact, so that the individual excess cancer risk is below 1E-4 with a target of 1E-6, and the threshold non-cancer index is less than 1.0.





Institutional ControlsInstitutional controls consisted of installing fencing with warning signs to restrict access to the treatment facility and implementing the continuing order to restrict access (HAFB 1998).


The SVE system at ST018 was in operation during the 1998 Five-Year Review. The review (HAFB EMR 1998) concluded that confirmation sampling was expected by the end of December of 1998. Sampling results would then be interpreted and closure would be determined based upon a review of the data with EPA and UDEQ. During the 1998 Review, pressure readings indicated that the radius of influence had exceeded the calculated design radius for the system. EPA Region VIII, UDEQ, and Hill AFB EMR representatives conducted a final inspection of the SVE system on 20 July 1998 and no significant concerns were identified. The system was later deactivated. A Continuing Order was also issued by the Base Commander in April of 1998 restricting access to, or disturbance of, the RVMF remedial equipment (AFI 32-7020). The 1998 review made no recommendations for the system at ST018.


Question A (Answer)

Yes


The SVE remedial action decreased the soil contamination of 1,1-DCE to below detectable concentrations (0.005 mg/kg) in all of the samples collected from the confirmation soil borings. The goal of the remedy was to decrease the concentrations of 1,1-DCE to less than 0.8 mg/kg.

Question B (Answer)

Yes


The 1,1-DCE MCL (0.8 mg/kg) for soil is still valid.

The RAOs for the remedy at ST018 is still valid.

Question C (Answer)

No


Not applicable.

VIII. Issues None.











The remedy associated with ST018 is protective of human health and the environment because the SVE system decreased soil contamination levels of 1,1-DCE to below the MCL. The site was recommended and accepted for NFRAP status in May 2001 (URS 2001).




OU 3 SD046 POND 2


III. Background Pond 2 was an ephemeral stormwater pond that received occasional excess surface runoff from Hill AFB until 1974. At that time, the storm drain was rerouted to Pond 3. Pond 2 has been a grass covered surface depression since then. In 1989, two soil samples were taken to analyze VOC concentrations at the site. Contaminants were not detected above quantitation limits for soils and no compounds were detected in the groundwater above federal drinking water standards. A PCB Clearance Certificate and a Finding of No Significant Contamination was submitted by Mr. Joseph H. Battaglia, the Base Commander, before the site was sold to Mr. Lyle Warner on 13 August 1991 (HAFB EMR 1992a). Pond 2 is located on the south side of Utah Highway 193 and is adjacent to the main property of Hill AFB (see Figure 1).


Not Applicable.


This site was not included in the 1998 Five-Year Review.


Question A (Answer)

Not Applicable


Not Applicable.

Question B (Answer)

Not Applicable



I. Introduction SD046 (Pond 2) was recommended for No Further Response Action Planned and accepted on 30 June 1992. The site was sold to Mr. Lyle Warner on 13 August 1991 (HAFB EMR 1992b).








OU 3 SD046 POND 2




Not Applicable.

Question C (Answer)

Not Applicable


Not Applicable.





SD046 was accepted for No Further Response Action Planned on 30 June 1992 because no significant contamination or health risk was found during investigations.




Operable Unit 4

I Introduction OU 4 is located on the northern boundary of Hill AFB and includes five IRP sites (see Table OU 4-1) that have active remediation in place to address contaminated groundwater and soil. The location of each IRP site is shown in Figure OU 4-1. OU 4 contains a TCE contaminated groundwater plume that extends off Base in the direction of South Weber Drive. Two locations in the distal portion of the plumes do show increasing contaminant levels, but the overall plume dimensions have been relatively static through time. Landfill No. 1 (LF011) was considered the sole source of contamination in the groundwater at OU 4 in the RI (USGS 1993) and the ROD (HAFB EMR 1994) established four media of concern and chose remedies for each of the media. The Spoils Area (OT020) was accepted as a non-hazardous site with no further remedial action planned in 1992 (Hirschi, S. 1992). Landfill No. 2 (LF012), the North Gate Dump (OT041), and the Munitions Dump (OT042) were found not to have released hazardous substances to the environment and were given NFRAP status in 1994 (HAFB EMR 1994). An area of high concentration (TCE in the groundwater above 1,000 µg/L) was discovered in the vicinity well U4-080 in 1996, suggesting the potential for an additional source near the Landfill No. 2 and the North Gate Dump areas. Table OU 4-1. OU 4 Site Identification

Site ID Site Name LF011 Landfill No. 1 LF012 Landfill No. 2 OT020 Spoil Pit OT041 North Gate Dump OT042 Munitions Dump

II Site Chronology


III Background Past operations at all five sites in OU 4 include: l Waste dumping and burning in the late 1940s at Landfills 1 & 2 until burning at Hill AFB

was terminated in 1967. Though there are no records of any industrial or hazardous waste disposal at these sites, it has been reported that Landfill No. 1 received wastes from the Ogden Arsenal that included waste oils and solvents from the refueling vehicle maintenance facility (ST018 in OU 3).

l Several drums of waste solvent were reportedly dumped from trucks in the North Gate Dump Area (OT041), but no drums have been found in that area.

l The Spoils Area (OT020) received construction debris (concrete, wood, and soil) from Base activities between 1972 and 1989.

l The Munitions Dump (OT042) was operated by the Ogden Arsenal as an aboveground storage area for munitions during World War II.


Groundwater, contaminated with metals and VOCs (primarily TCE), underlies approximately 69 acres (30-50 ft bgs) at OU 4 and extends northward and off-Base, down the steep slope, into the cities of Riverdale and South Weber. Sources other than Landfill No. 1 may be contributing to the plume (Landfill No. 2 [LF012] and North Gate Dump [OT041]); however, additional investigations are required to determine the actual source of contamination. Beyond the Base boundary, seeps and springs have been observed flowing out of the hillside. The Davis-Weber Canal, a privately owned irrigation canal, is used each year from April to October, and is located the middle of the slope. Results of analyses of canal water during the RI indicated that the canal has not been a source of contamination, nor is it contaminated with COCs at OU 4. Located beyond the slope are residential areas and small farms. The TCE contamination has not extended into any area underlying residential areas. Groundwater in the shallow contaminated aquifer is not currently used as a source of drinking water.

IV Remedial Actions Remedial actions have only been implemented at Landfill No. 1 (LF011) to address both on-Base and off-Base contamination. Remedial actions and remedies have not been applied to the other four IRP sites at OU 4. The remedial action objectives (RAOs) for OU 4 were detailed separately for landfill contents, groundwater and surface water, and indoor air in the ROD (HAFB EMR 1994) and include: Landfill Contents Remedy The landfill contents remedy included regrading and revegetation of the landfill cap to reduce infiltration and control runoff, and the installation of a soil vapor extraction system to remove vapor from the landfill contents. The SVE system has not been installed to date because analysis of soil gases show that gas concentrations are too low to justify installation. A "Proposed Explanation of Significant Differences for Operable Unit 4 Landfill Contents Remedy" (EPA Region VIII 1995), was completed to address the elimination of SVE as a portion of the landfill remedy. Piping placed beneath the cap as part of the planned SVE system is currently used to collect landfill leachate. The leachate is periodically collected, sampled and disposed of at the IWTP. There are institutional controls (HAFB 1998) associated with this remedy to restrict access and potential exposure pathways which include fencing, groundwater use restrictions, easements, leases, and signs.

Groundwater Remedy The groundwater remedy includes the installation of a passive groundwater extraction system. The Horizontal Drain Upgrade System (HDUS) includes an air stripper to pre-treat the extracted groundwater prior to discharge to the Central Weber Sewer Improvement District (CWSID), if necessary. There are institutional controls (HAFB 1998) associated with this remedy to restrict access and potential exposure pathways which include fencing, groundwater use restrictions, easements, leases, and signs. Surface Water Remedy The surface water remedy consists of local collection of contaminated surface water at each spring/seep site, treatment using carbon adsorption, and discharge to the subsurface using


infiltration trenches. The collection systems have not been installed to date due to low flows at the spring/seep sites. However, they are monitored on a regular basis per the PSVP (CH2M 2001). There are institutional controls associated with this remedy to restrict access and potential exposure pathways which include fencing, groundwater use restrictions, easements, leases, and signs. Air Remedy The air remedy consists of semi-annual monitoring of the off-Base residences overlying contaminated groundwater that is in excess of MCLs. To date, there has not been any indoor air sampling conducted in off-Base residences because there are none located over the plume.


In the 1998 Five-Year Review (HAFB EMR 1998), it was anticipated that a ROD amendment might be needed to resolve the usefulness of the SVE system at the Landfill No. 1, the low flow rates of the seeps and springs, and the overall practicality of reaching MCLs. Specific progress made since the 1998 FYR includes: l The HDUS air stripper water effluent permit was changed in August 2000, allowing for a

total concentration of 2,130 µg/L total VOCs from the previous limit of 100 µg/L total VOCs. The air stripper was subsequently taken off line on January 2001 due to consistent untreated effluent concentrations well below the new discharge limit (URS 2002).

l A review of the site conceptual model for OU 4 was completed to determine whether a quantitative geosystem model of the site was warranted for future site management purposes (JS/I 2002).

l A slope stability study was conducted to determine the long-term impact of additional extraction trenches (URS 2001).

l The low flow rates of the seeps and springs and the overall practicality of reaching MCLs has not yet been addressed with a ROD amendment. An amendment of the ROD for the seeps and springs is not needed to address the flow rate since the ROD addresses both a low-flow and a higher-flow treatment option.

l The issue of reaching MCLs is a basewide issue that may be addressed at a later date. VI Five-Year Review Process

Site review was conducted per the process described for the overall 2003 FYR. VII Technical Assessment

Results of the technical assessment for each site in OU 4 and for the operable unit as a whole are listed in Table OU 4-3. Details of the technical assessment for each site in OU 4 are provided in their respective site summaries (see Section XIII).



Technical Assessment * Site ID Remedy Question A Question B Question C


Year Review

LF011 Landfill Cap, HDUS, seep/spring control,

air monitoring No No Yes Protective in the

short-term 2008

LF012 NA NA NA NA NA 2008


OT041 NA NA NA NA NA 2008


OU 4

Landfill Cap, groundwater

extraction, surface water and

groundwater use restrictions, site

access restrictions

No No Yes Protective in the short-term 2008



remedy? NA = Not applicable


No.

Groundwater Remedy The groundwater remedy was intended to provide hydraulic containment, which would prevent further migration of contaminated water off-Base (HAFB EMR 1994). The HDUS is not functioning as intended and does not effectively contain the plume. Furthermore, spring U4-308 and well U4-069 in the distal portion of the plumes do show increasing contaminant trends. Even with the limited impact the HDUS system has on the plume, the overall plume dimensions are relatively stable through time and the composite plume does not seem to be growing significantly (JS/I 2002). Landfill Contents Remedy The Landfill No. 1 cap is intended to limit infiltration and reduce the leaching of contaminants from the landfill contents into the underlying groundwater (HAFB EMR 1994). Proper function of the landfill cap cannot be determined without an additional in-depth data evaluation. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? No. The Reference Dose for Inhalation (RfD(i)) for boron is now available at 5.7x10-3 mg/kg/day (EPA Region III 2002), which may affect the cleanup level for boron (2,700 ug/L) stated in the ROD. The EPA and UDEQ have established an action level for TCE in indoor air at 0.43 ppbv.


Question C: Has any other information come to light that could call into question the protectiveness of the remedy? Yes. Groundwater Remedy Due to the increasing contaminant trends in spring U4-308 and well U4-069 in the distal portion of the plumes and the evidence that suggests the HDUS system is not effectively containing the plume, it appears that the RAOs pertaining to the prevention of further degradation of the groundwater quality are not being achieved. However, it should also be noted that the composite plume does not seem to be growing significantly and the overall plume dimensions are relatively static through time (JS/I 2002). The possibility of additional soil contamination was discovered in March 2002. Contaminated water from the HDUS system was discharging into the surrounding soil through a hole in the effluent line and was repaired in April 2002. The air stripper was taken off-line in January 2001 due to an increase in the allowable VOC content in the effluent stream leading to the CWSID. Therefore, untreated groundwater may have been leaking into the surrounding soils for a maximum duration of 16 months. The surrounding soil was not sampled during repair. This issue was discussed during the FYR interview session with EMR and this location was promptly sampled on 13 March 2003. Analytical results of soil samples showed trace levels of TCE were found, and the results were compared with Risk-Based Screening Levels (RBSL) to determine if soils present a risk to human health or the environment. It was determined that contamination detected in the soil samples was below Risk-Based Screening Levels (CH2M 2003). Landfill Contents Remedy After reviewing the data available for the PSVP-specified monitoring locations, an increasing TCE trend in one of the two monitoring points indicates that additional data evaluation and investigation are required before long-term protectiveness can be determined.

VIII Issues

Based on the information reviewed, issues that may affect protectiveness of the selected remedies at OU 4 are listed below:

OU 4 - Treatment and Containment l The long-term monitoring data have not been analyzed in detail to provide specific

recommendations on proper plume management and future HDUS operations. l Although the OU 4 plume is not currently impacting receptors, the remedial actions that are

presently in place do not effectively contain the plume. Furthermore, evidence of increasing contaminant trends exists in the distal portions of the plumes. Therefore, the current actions are not in compliance with the RAOs set forth in the ROD, namely to prevent further degradation of groundwater quality in accordance with the Utah Corrective Action Cleanup Policy. This issue is somewhat offset by the information detailed in the Jacobs Sverdrup report, which suggests that the overall plume dimensions, are “relatively static” (JS/I 2002).

l Regulatory changes to the COC levels may affect the protectiveness of a remedy. l Additional source areas may have been identified near Landfill No. 2 (LF012) and the North

Gate Dump Areas (OT041), two sites with NFRAP status.


l The existing well network may not be sufficient to monitor conditions within and at the distal edges of the plume.

Landfill No. 1 - Treatment and Containment l The effectiveness of the landfill cap in limiting infiltration and reducing the contaminant

leaching is uncertain based on analytical results from the downgradient landfill monitoring location, U4-047.

l No action levels (flow level) exist in either the ROD or the PSVP that would require implementation of a surface water collection and treatment system.

l An ESD or a ROD amendment has not been generated to address the bypass of the air stripper treatment system, as specified in the ROD.

Landfill No. 1 - Operations and Maintenance l Upon inspection of the HDUS, several drain lines were exposed. The lines should have at

least 24" of cover to prevent freezing and pipe breakage. Erosion is a significant problem in the area, possibly due to poor compaction during construction.

l No signage is evident in the off-Base area to prevent unauthorized excavation. l The HDUS flows are declining, but the cause is unknown. l Analytical data from water collected from the landfill leachate collection sumps and HDUS

drain set flows were not readily available to evaluate the remedy performance. l Currently, the remedies for the seeps are protective. However, protection in most cases is due

to low flow from the seeps and not due to institutional controls. One seep, U4-308, does flow on private property with TCE concentrations above MCLs, but does not have institutional controls. The property owner has been informed but the owner does not want a fence installed.



OU 4 - Treatment and Containment l Thoroughly evaluate existing data and determine if additional data and/or modeling are

required to develop a plume management plan that meets the RAOs. l Evaluate clean-up levels for COCs and amend the ROD, if required, to address current

ARAR levels. l Continue to monitor wells in the plume area and if sustained increasing trends are observed

which result in an expansion of plume boundaries, an evaluation should be completed to determine if additional source area characterization is warranted.

l Review the PSVP in light of remedy protectiveness and achievement of RAOs and the data required to ascertain these. Update the PSVP, if necessary and evaluate the need to perform the PSVR in a more timely fashion than the current FFA schedule suggests.

l Evaluate the existing well network to determine if it is adequate to monitor conditions within and at the distal edges of the plume and add additional monitoring locations as necessary.

Landfill No. 1 - Treatment and Containment l Complete an investigation into the increase of TCE concentrations in U4-047 and closely

monitor future analytical results from this location. l Establish flow levels for implementation of a surface water collection and treatment system at

the seeps.


l Complete and ESD or a ROD amendment to address the bypass of the air stripper treatment system.

Landfill No. 1 - Operations and Maintenance l Protect drain lines from damage with proper soil cover. l Install additional signage to prevent unauthorized off-Base excavation. l Evaluate the causes of reduced flows in the HDUS drain sets (upper, middle, and lower

horizontal drain sets) (see Figure OU 4-1) using video logs and flow data. Access points at each drain line may be necessary to allow a video log and to obtain the flow data of each line.

l Data from the sumps in Landfill No. 1 and the drain set flows of the HDUS system should be included in the ERPIMS database to allow for trends to be examined. All data that are required in the PSVP should be included in the database. If no data are available during the sampling round or if a point has been discontinued, it should be noted in the database for clarification.

l Complete a risk-based analysis for seep U4-308 and if risk-based levels are exceeded, institutional controls should be enforced.

X Protectiveness Statement for OU 4

The remedies at OU 4 protect human health and the environment in the short-term. There is no immediate risk to human health and the environment at this site. This, however, is not due to the implementation of the groundwater remedy at the site, but is due to institutional controls and the lack of receptors. Increasing concentrations observed in some monitoring wells indicate the potential for plume migration. If plume migration does occur, completion of an exposure pathway is possible, causing potential risk to human health and the environment. Also, within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 4. Therefore, a re-evaluation of potential risk at OU 4 must be conducted before the long-term protectiveness of the current remedies can be determined.

XI Next Review

The next FYR for OU 4 is required by 2008. No future review is required for the Spoils Area (OT020) or the Munitions Dump (OT042) sites because no further remedial actions are planned at these sites. Due to the unknown source of the elevated contamination levels near Landfill No. 2 (LF012) and the North Gate Dump Areas (OT041), these IRP sites require an additional review in 2008 to ensure NFRAP status is still applicable.


(CH2M 2001) Operable Unit 4 Performance Standard Verification Plan, CH2M Hill, November 2001. (CH2M 2003) Contract F42650-98-D-0067, Delivery Order 0020, Cost Reimbursable Project Number 1. – Draft Operable Unit 4 Sewer Connection Soil Sampling Letter Report, CH2M Hill, April 2, 2003. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002.


(EPA Region VIII 1995) Proposed Explanation of Significant Differences for Operable Unit 4 Landfill Contents Remedy, USEPA Region VIII, March 1995. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1994) Record of Decision and Responsiveness Summary for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42), Hill AFB EMR, June 1994. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (Hirschi, S. 1992) Decision Document for Site OT20- Spoils Area, Hill AFB EMR, June 1992. (JS/I 2002) Site Conceptual Model Review OU 4, Jacobs Sverdrup/Intera Inc., December 2002. (MW 1993) Proposed Plan for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42), Montgomery Watson, September 1993. (MW 1997) Annual Report for Operable Unit 4 - 1997, Montgomery Watson, November 1997. (URS 2001) Geotechnical Report Hill Air Force Base OU-4 Proposed Extraction Trenches Long-Term Impact Review, URS, March 12, 2001. (URS 2002) Treatment System Operation Report for OU 4, 2002, URS, March 2002. (USGS 1990) Technical Memorandum Second Draft Vol 1 Report Site Characteristics Summary Report, First Phase of Remedial Investigation, Operable Unit 4, Landfills 1 and 2, U.S. Geological Survey, January 1990. (USGS 1993) Addendum to Remedial Investigation Report for Operable Unit 4, Volume 12 Appendices A, B, C, D, E, and F (Vol 2 of 8), U.S. Geological Survey, April 1993.



OU 4 OPERABLE UNIT 41981 Phase I Records Search Provided a history of landfill operations and indicated that

organic chemicals had not been disposed in Landfills 1 and 2.Technical Memorandum Second Draft Vol 1 Report Site Characteristics Summary Report, First Phase of Remedial Investigation, Operable Unit 4, Landfills 1 and 2

1987 Remedial Investigation 13 volatile organic and 2 inorganic contaminants were detected in water from monitoring wells and seeps in the area of OU 4. Comparison of the concentrations of observed contaminants to appropriate standards indicated that TCE exceeded the primary MCL in water from 20 monitoring wells and 3 seeps; benzene exceeded the MCL in 1 well; and 1,2-DCA, nitrate, and sulfate did not exceed the MCL in water from any of the wells or seeps. TCE identified as CoC.

Vol. 1 Report Remedial Investigation Report for Operable Unit 4, First Draft

04 1993 Addendum to the RI and Risk Assessment

Findings of the initial RI were confirmed and revised, the extent and quantity of the ground-water contamination were defined, and the primary source of contamination was identified as Landfill 1.

Remedial Design Work Plan for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42)

10 1993 Proposed Plan (public comments) Public meeting on Tuesday, October 19, 1993 Proposed Plan for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42)

06 1994 Record of Decision ROD completed. No removal actions, remedial actions, notices of violation, or other enforcement actions taken prior to the ROD.






08 1996 Conceptual Model A second small source was located down-slope of Landfill 2. Annual Report for Operable Unit 4 - 1997

LF011 LANDFILL NO 11946 Unofficial Dumping Photos in the RI show activity in 1946 at Landfill 1. Site Conceptual Model Review OU 4

1955 Facility use between 1955 and 1967 Landfill 1 officially operated as a hillside dump with a daily burning operation from 1955 until 1967, when burning at Hill AFB was terminated and the dump was closed.


1982 Installation Restoration Program Landfill 1 identified as potential hazardous site in Phase I of the IRP.


11 1985 Remedial Investigation Groundwater monitoring was conducted from November 1985 to November 1987 during the Phase II Installation Restoration Program (IRP). High concentrations of trichloroethene (TCE), 4,185 µg/L, were detected in the well downgradient of Landfill 1. The detection of TCE indicated that further investigation was necessary.

Technical Memorandum Second Draft Vol 1 Report Site Characteristics Summary Report, First Phase of Remedial Investigation, Operable Unit 4, Landfills 1 and 2





1991 Semi-annual ground water sampling initiated

Site Conceptual Model Review OU 4

1993 Quarterly ground water sampling began for VOCs

Selected wells Site Conceptual Model Review OU 4

1993 2001 Annual Report The horizontal drain system was initially installed on a temporary basis as part of a treatability study to ascertain if the drains could collect groundwater for treatment successfully. Wastes generated at the time were disposed through the Base Hazardous Waste Storage Facility.

Treatment System Operation Report for OU 4, 2002

04 1993 Addendum Remedial Investigation Landfill 1 determined to be the "most probable" source of TCE. Addendum to Remedial Investigation Report for Operable Unit 4, Volume 12 Appendices A, B, C, D, E, and F (Vol 2 of 8)

03 1995 Proposed Explanation of Significant Differences (PESD)

The significant differences between the landfill contents remedy described in the ROD and as proposed in this PESD were: 1) SVE treatment of the landfill contents was not to be constructed. This included all SVE equipment, structures, and associated facilities. 2) Perched water within the landfill contents would be removed, conveyed to the on-Base Industrial Wastewater Treatment Plant (IWTP) and treated.

Proposed Explanation of Significant Differences for Operable Unit 4 Landfill Contents Remedy





09 1995 Construction Completed Landfill 1 Cap construction began in Sept. 1995 and completed in June 1996

Remedial Action Report for the Landfill 1 Cap Site (IRP Site LF11)

09 1996 Construction Completed Construction of the Horizontal Drain Upgrades began on September 13, 1996, and was completed on June 5, 1997.

Remedial Action Report Phase II Remedial Action Horizontal Drain Upgrades Operable Unit 4

1997 Remediation Study Remediation by Natural Attenuation showed biodegradation unlikely. This was re-emphasized in the Site Conceptual Model Review in December 2002.


1997 Air Stripper Online Air stripper reduced total VOC content in extracted groundwater to below 100 ug/L, in accordance with the discharge permit.

Annual Report for Operable Unit 4 - 1997

1998 Remedial Design Design basis presented for the use of groundwater extraction trench systems for removal of contaminants in the plume to help the HDUS with the Groundwater Remedy.

Remedial Design Report and Work Plan Phase III Groundwater Extraction Trench System Operable Unit 4

2001 Geotechnical Evaluation Report evaluation of the impact of the Groundwater Extraction Trench System would have on the surrounding geology, short-term and long-term, and the effectiveness of the system as a remedial action. It was recommended to re-evaluate the design.






01 2001 Air stripper taken offline Use of the system bypass was approved in January 2001 as a result of an increase in the allowable discharge concentration for the CWSID discharge permit. The bypass connects the influent line directly to the effluent line, therefore bypassing the equalization tank and air stripper. The air stripper was taken offline, and recovered groundwater was redirected through the bypass on January 23, 2001.

Treatment System Operation Report for OU 4, 2002

03 2001 Slope Stability Study Completed A slope stability study was conducted to determine the long-term impact of additional extraction trenches.

Geotechnical Report OU 4 Proposed Extraction Trenches Long-Term Impact Review

03 2002 Possible Contamination Discovery of blockage and break in the drain line from the treatment building to the sewer line. Possibility of additional contamination where the untreated water leaked into the surrounding soil.

Interview with Holly Renn, PM for O&M Contractor

LF012 LANDFILL NO 21945 Evidence of use Photos show use of Landfill 2 in the mid to late 1940's Site Conceptual Model Review OU 4

1946 Unofficial Dumping Photos in the RI show activity in 1946 at Landfill 2. Site Conceptual Model Review OU 4





1963 Operations at Landfill 2 between 1963 and 1965

Landfill 2 officially operated between 1963 and 1965, when burning at Hill AFB was terminated and the dump was closed. "General waste" was dumped down the side of the hill and periodically burned.


1982 Remedial Investigation Landfill 2 identified as potential hazardous site in Phase I of the IRP.


11 1985 Remedial Investigation Groundwater monitoring was conducted from November 1985 to November 1987 during the Phase II Installation Restoration Program. In a well downgradient from Landfill 2, the concentration of TCE was 6.08 µg/L. The detection of TCE indicated that further investigation was necessary.

Technical Memorandum Second Draft Vol 1 Report Site Characteristics Summary Report, First Phase of Remedial Investigation, Operable Unit 4, Landfills 1 and 2

06 1994 NFRAP Accepted Based on information revealed in the Remedial Investigation, Landfill 2 is noted as not being a source of contamination. The ROD is considered the NFRAP document.


OT020 SPOIL PIT1972 Operations at Spoils Pit between

1972 and 1989The Spoils Area was an active disposal site from 1972 until 1989. It received construction debris such as concrete, wood, and soils from the Base.

Decision Document for Site OT20- Spoils Area





11 1988 Soil Gas Survey A soil gas survey that included six sampling points at OT20 was conducted. The soil gas was tested for trichloroethane, trichloroethene, tetrachloroethene, methane, benzene, toluene, xylene, and total hydrocarbons. The soil gas survey conducted at OT20 indicated TCA, TCE and PCE at part per trillion levels. Methane was detected at part per million levels.


01 1989 Initial Findings Reported Initial findings of the soil gas survey were presented in the Informal Technical Information Report For Soil Gas Survey Conducted Along Perimeter Road and Spoils Area, Hill AFB, Utah. Results of the report were discussed at a 19 January 1989 meeting with representatives of USAF OEHL and Hill AFB.


04 1989 Well Installation The U.S. Geological Survey installed a groundwater monitoring well immediately downgradient of OT20 (U4-027).


07 1989 Groundwater Sampling Groundwater samples were collected and analyzed for volatiles, semi-volatiles, common anions, pH, alkalinity, and selected trace elements. Analysis of groundwater samples taken from the well (U4-207) reported no compound detected at or above Federal drinking water standards.


08 1990 Final Report Final Report Site Evaluation Report for Perimeter Road and the Spoils Area.






06 1992 NFRAP Accepted “Conclusion: No further response action is required at site OT20 -Spoils Area. OT20 will no longer be tracked as an IRP site.”


OT041 NORTH GATE DUMP OP UNIT 41955 Operations at North Gate Dump North Gate Dump Areas used for solvent disposal. Specific

dates are unknown.Site Conceptual Model Review OU 4

06 1994 NFRAP Accepted Based on information revealed in the Remedial Investigation, North Gate Dump Area is noted as not being a source of contamination. The ROD is considered the NFRAP document.


OT042 MUNITIONS DUMP OP UNIT 41940 Operations at Munitions Dump Munitions Dump was active from 1940 through 1946 and used

to store surplus weapons above-ground.Site Conceptual Model Review OU 4

06 1994 NFRAP Accepted Based on information revealed in the Remedial Investigation, Munitions Dump is noted as not being a source of contamination. The ROD is considered the NFRAP document.







III. Background Landfill No. 1 is located along the top of a steep, terraced escarpment of the Weber Delta overlooking the Weber River Valley. TCE contamination underlies approximately 69 acres (30-50 ft bgs) and extends north down the steep slope, off-Base, into the cities of Riverdale and South Weber. The ROD suggests that Landfill No. 1 is the sole source of this contamination. Other sources, such as Landfill No. 2 (LF012) and the North Gate Dump Areas (OT041), may be contributing to the plume (MW 1997, JS/I 2003), but further investigations will need to be performed to make that determination.

Beyond the base boundary, the hill continues downward and seeps have been observed flowing out of the hillside. The slope is vegetated with shrubs and grasses. The Davis-Weber Canal, a privately owned irrigation canal used each year from April to October, is in the middle of the slope, and is approximately 600 feet north and approximately 100 feet below Landfill No. 1. Results of analyses of canal water during the RI indicated that the canal has not been a source of contamination, nor have chemicals from OU 4 contaminated it.

Beyond the slope, there are houses and small farms. The TCE contamination has not extended into any area that includes the homes or farms. Groundwater in the contaminated area is not currently used as a source of drinking water.

Landfill No. 1 was approximately 25 feet deep during operations and covers an area of five acres. The landfill was operated as a dump site with a daily burning operation from 1955 until 1967, when burning at Hill AFB was terminated. All landfill operations were also terminated and the landfill was closed at that time. Though there are no records of any organic chemical disposal, it has been reported that Landfill No. 1 received wastes from the Ogden Arsenal that included waste oils and solvents from the vehicle maintenance facility (USGS 1990).


I. Introduction The Landfill No. 1 area, IRP site LF011, is located on the northern boundary of Hill AFB (see Figure OU 4-1). A groundwater plume originating from the landfill extends off Base in the direction of South Weber Drive and is currently migrating in a northwesterly direction, approximately parallel to South Weber Drive. The main contaminant of concern is TCE with a maximum concentration of approximately 12,000 ug/L for CY 2002. The ROD established four media of concern with remedial actions associated with these media. The four media types are: groundwater, surface water, landfill contents, and air (MW 1993).




GW ARSENIC 50 ug/L






GW BARIUM 2,000 ug/L

GW BENZENE 5 ug/L

GW BORON 2,700 ug/L

GW CHLOROFORM 100 ug/L

SW CHLOROFORM 100 ug/L



GW METHYL ETHYL KETONE (2-BUTANONE) 830 ug/L

GW NICKEL 100 ug/L

GW SELENIUM 50 ug/L


GW TOLUENE 1,000 ug/L

GW trans-1,2-DICHLOROETHENE 100 ug/L

SW trans-1,2-DICHLOROETHENE 100 ug/L

AIR TRICHLOROETHENE (TCE) 5 ug/m3



GW XYLENES, TOTAL 10,000 ug/L

* Groundwater and Surface Water - Meet chemical-specific ARARs, which are drinking water MCLs.* Landfill Contents - Limit cancer risk to less than 1E-4 with a target of 1E-6 due to accidental ingestion, dermal contact, or inhalation of vapors.* Air (Indoor) - Prevent inhalation of noncarcinogens at levels exceeding a hazard index of 1 within off-Base residences.* Air (Indoor) - Prevent inhalation of carcinogens in excess of 1E-6 cancer risk within off-Base residences.* Air (Indoor) - Prevent the migration of contaminated soil gas into residences.

* Groundwater and Surface Water - Maintain contaminant concentrations low enough to avoid chronic health effects (as indicated by a hazard index of less than 1).* Groundwater and Surface Water - Limit cancer risk to less than 1E-4 with a target of 1E-6 due to accidental ingestion, dermal contact, or inhalation of vapors.






GroundwaterThe groundwater remedy, the Horizontal Drain Upgrade System, includes the installation of a groundwater extraction system that includes an air stripper to pre-treat the extracted groundwater prior to discharge.

Three sets of horizontal drains were installed in 1993 on a temporary basis to determine if horizontal drains could successfully collect water for treatment. Each set contained three individual drains that passively convey water to a common point. One of the drains in the lowest set was abandoned when it was damaged during construction of the lines.

Extracted groundwater was conveyed by a dual-walled piping system to an air stripper treatment building and on to the Central Weber Sewer Improvement District for treatment via the City of Riverdale sanitary sewer line. When the discharge permit was changed in August, 2000, allowing for a total concentration of 2,130 ug/L total VOCs from the previous limit of 100 ug/L total VOCs, the air stripper was taken offline (Jan 2001) at the request of Hill AFB EMR. The average discharge concentration from the drain sets was 433 ug/L for calendar year (CY) 2002. The system effluent now is directly discharged to the local Publicly Owned Treatment Works (POTW) with an average flow rate of approximately 3 gallons per minute (gpm).

Surface WaterThe surface water remedy consists of local collection of contaminated surface water at each spring/seep site, treatment using carbon adsorption, and discharge to the subsurface using infiltration trenches. There are institutional controls associated with this remedy to restrict access and potential exposure pathways. The collection systems have not been installed due to low flows at the spring/seep sites but they are monitored on a regular basis per the PSVP (CH2M 2001).

Landfill ContentsThe landfill contents remedy included regrading and revegetation of the landfill cap to reduce infiltration and control runoff and the installation of a soil vapor extraction system to remove vapor from the landfill contents. However, the SVE system was never installed because pilot testing (MW 1994) concluded that the TCE levels were below the levels removable by SVE. It was then determined that removal of the contaminated groundwater would be more effective in reducing the contaminant mass and in reducing the potential for contaminant migration. A "Proposed Explanation of Significant Differences for Operable Unit 4 Landfill Contents Remedy", dated March 1995, was completed to address the elimination of SVE as a portion of the landfill remedy.

Indoor Air

* Groundwater and Surface Water - Prevent further degradation of ground-water quality in accordance with the Utah Corrective Action Cleanup Policy (R315.101).* Landfill Contents - Eliminate the source(s) of ground-water contamination either through removal or source control in accordance with Utah Corrective Action Cleanup Policy.* Landfill Contents - Maintain contaminant concentrations low enough to avoid chronic health effects (as indicated by a hazard index of less than 1).





The indoor air remedy consists of semi-annual monitoring of the off-Base residences overlying the contaminated groundwater plume. At the present, there are no residences within the plume boundary, and therefore no monitoring is being conducted. If the plume migrates under any residences, monitoring would begin. If VOCs are detected in the air, the affected residences will have a ventilation system installed along the foundation of the home and monitoring of the ventilation system will continue semi-annually to ensure effectiveness. If concentrations of VOCs attributable to OU 4 exceed the indoor air regulatory limit an emission control device will be used.

Institutional Controls

Institutional controls for groundwater include:* Well use advisory, water rights, and well drilling restrictions, and* Easements and leases as necessary for monitoring and installation of equipment.

Institutional controls for surface water includes:*Water use advisories, and water rights restrictions for contaminated surface water,*Obtaining easements and/or leases on properties where monitoring is required, and*Fencing seeps which provide sufficient flow for consumption by humans and livestock.

Institutional controls for landfill contents include:* A continuing order from the Base Commander (HAFB 1998) concerning landfill restrictions,* Recording a notice to restrict exposure to and maintain integrity of remedial action at Landfill No. 1, and * Fencing and warning signs.


In the 1998 Five-Year Review (HAFB EMR 1998), it was anticipated that a ROD amendment might be needed to resolve the usefulness of the SVE system at Landfill No. 1, the low flow rates of the seeps and springs, and the overall practicality of reaching MCLs. * The HDUS air stripper water effluent permit was changed in August 2000, allowing for a total concentration of 2,130 mg/L total VOCs from the previous limit of 100 ug/L total VOCs. The air stripper was subsequently taken off line on January 2001 due to consistent untreated effluent concentrations well below the new discharge limit.* A review of the site conceptual model for OU 4 was completed to determine whether a more quantitative geosystem model of the site was warranted for future site management purposes (JS/I 2002). * A slope stability study was conducted to determine the long-term impact of additional extraction trenches (URS 2001). * The low flow rates of the seeps and springs and the overall practicality of reaching MCLs has not yet been addressed with a ROD amendment. An amendment of the ROD for the seeps and springs is not needed to address the flow rate since the ROD addresses both a low-flow and a higher-flow treatment option. * The issue of reaching MCLs is a basewide issue that may be addressed at a later date.






Question A (Answer)

No


Groundwater RemedyThe groundwater remedy was intended to provide hydraulic containment, which would prevent further migration of contaminated water (HAFB EMR 1994). The HDUS is not functioning as intended and does not effectively contain the plume. Furthermore, spring U4-308 and well U4-069 in the distal portion of the plumes do show increasing trends. Even with the limited impact the HDUS system has on the plume, the overall plume dimensions are relatively stable through time and the composite plume does not seem to be growing significantly (JS/I 2002).

Surface Water RemedyThe ROD recognized a lack of treatable flow from the seeps. Installation of a seep water treatment system will be reevaluated when sufficient flows are present.

Landfill Contents RemedyThe Landfill No. 1 cap is intended to limit infiltration and reduce the leaching of contaminants from the landfill contents into the underlying groundwater (HAFB EMR 1994). Proper function of the landfill cap cannot be determined without additional data evaluation. A cursory review of the representative groundwater locations per the OU 4 PSVP (CH2M 2001), wells U4-046 and U4-047, illustrate different trends. Since the landfill cap was installed in 1994, the concentration of TCE in U4-047 has decreased from approximately 2,500 ug/L to 200 ug/L over a 9-year period. This time frame was also reviewed for the U4-046 monitoring location. TCE concentrations were relatively stable through 1998 at 6,000 ug/L with a one year decrease to 2,200 ug/L TCE and a subsequent increase to 12,000 ug/L TCE in the last four years.

Annual landfill inspections are being conducted and deficiencies are corrected in a timely manner. The amount of water collected through french drains under the landfill has been minimal.

Air (Indoor) RemedyNo residences are located within the boundary of the plume. Therefore, there is no need for indoor air monitoring at this time.

Question B (Answer)

No

Question B (Comment) TCE is the main contaminant of concern, but changes in other cleanup levels may need to

be reevaluated.Cleanup Level Changes include:* Arsenic cleanup level of 50 ug/L is currently valid. However arsenic standard of 10 ug/L will be effective on 1/26/2006.






* The Reference Dose for Inhalation (RfD(i)) for boron is now available at 0.0057 mg/kg/day (EPA Region III 2002), which may affect the cleanup level for boron (2,700 ug/L) stated in the ROD. * The EPA and UDEQ have established an action level for TCE in indoor air at 0.43 ppbv. The new action level does not affect the remedy at this time.

Because land use has not changed, the exposure assumptions used in the risk assessment for OU 4 remain valid.

The remedial action objectives listed in the OU 4 ROD for this site are still valid.

Question C (Answer)

Yes


Groundwater RemedyDue to the increasing contaminant trends in spring U4-308 and well U4-069 in the distal portion of the plumes and the evidence that suggests the HDUS system is not effectively containing the plume, it appears that the RAOs pertaining to the prevention of further degradation of the groundwater quality are not being achieved. However, it should also be noted that the composite plume does not seem to be growing significantly and the overall plume dimensions are relatively static through time (JS/I 2002). The possibility of additional soil contamination was discovered in March 2002. Contaminated water from the HDUS system was discharging into the surrounding soil through a hole in the effluent line. The line was repaired in April 2002. The air stripper was taken off-line in January 2001 due to an increase in the allowable VOC content in the effluent stream leading to Central Weber Sewer Improvement District. Therefore, untreated groundwater may have been leaking into the surrounding soils for a maximum duration of 16 months. The surrounding soil was not sampled during repair. This issue was discussed during the FYR interview session with EMR and this location was promptly sampled on 13 March 2003. Analytical results of soil samples showed trace levels of TCE were found, and the results were compared with Risk-Based Screening Levels (RBSL) to determine if soils present a risk to human health or the environment. It was determined that contamination detected in the soil samples was below Risk-Based Screening Levels (CH2M 2003).

Surface Water RemedyNo additional information has surfaced that calls into question the protectiveness of the selected remedy. The samples taken from the flowing seeps are above the MCL for TCE, but institutional controls prevent pathway completion to receptors. The flow from the seeps is too low for the ROD-recommended treatment.

Landfill Contents RemedyAdditional information has become available that calls into question the protectiveness of the remedy. The data available for two PSVP-specified monitoring locations (U4-046 and U4-047) suggest an increasing TCE trend in one of the two monitoring points. Therefore,





additional data evaluation and investigation are required before protectiveness can be determined. Monitoring data from the sumps is not available in the ERPIMS database for evaluation.

Air (Indoor) RemedyNo homes are located within the plume boundary. Therefore, there are no issues related to indoor air.

VIII. Issues Treatment and Containment* Although the OU 4 plume is not currently impacting receptors, the remedial actions that are presently in place do not effectively contain the plume. Furthermore, evidence of increasing contaminant trends exists in the distal portions of the plumes. Therefore, the current actions are not in compliance with the RAOs set forth in the ROD, namely to prevent further degradation of groundwater quality in accordance with the Utah Corrective Action Cleanup Policy. This issue is somewhat offset by the information detailed in the Jacobs Sverdrup report, which suggests that the overall plume dimensions, are “relatively static” (JS/I 2002).* The long-term monitoring data have not been analyzed in detail to provide specific recommendations on proper plume management and future HDUS operations.* The effectiveness of the landfill cap in limiting infiltration and reducing the contaminant leaching, based on analytical results from the downgradient monitoring location (U4-047), is uncertain.* No action levels (flow level) exist in either the ROD or the PSVP that would require implementation of a surface water collection and treatment system.* Regulatory changes to the COC levels may affect the effectiveness of a remedy.* The existing well network may not be sufficient to monitor conditions within and at the distal edges of the plume.* An ESD or a ROD amendment has not been generated to address the bypass of the air stripper treatment system, as specified in the ROD.

Operations and Maintenance* Upon inspection of the HDUS, several drain lines were found exposed. The lines should have at least 24" of soil cover to prevent freezing and pipe breakage. Erosion is a significant problem in the area, possibly due to poor compaction during construction.* No signage is evident in the off-Base area to prevent unauthorized excavation.* The HDUS flows are declining, but the cause is unknown.* Operating data were not readily available to evaluate the remedy performance.* Currently, the remedies for the seeps are protective. However, protection in most cases is due to low flow from the seeps and not due to institutional controls. One seep, U4-308, does flow on private property with TCE concentrations above MCLs, but does not have institutional controls. The property owner has been informed but the owner does not want a fence installed.

IX. Recommendations Treatment and Containment* Complete an in-depth review of the existing data as they pertain to the effectiveness of the landfill cap. If the existing data do not provide an adequate assessment of the





landfill cap effectiveness, make recommendations for additional data collection and incorporate these recommendations into the OU 4 PSVP.* Review existing data, apply the current conceptual groundwater model (JS/I 2002), and make operational suggestions associated with the HDUS system.* Establish flow levels for implementation of a surface water collection and treatment system at the seeps.* Evaluate clean-up levels for COCs and amend the ROD, if required, to reflect current risk levels.* Evaluate the existing well network to determine if it is adequate to monitor conditions within and at the distal edges of the plume. Add additional monitoring points as necessary.* Complete an investigation into the increase of TCE concentrations in U4-047 and closely monitor future analytical results from this location for trends.* Address the above issues and recommendations, particularly the discovery of new potential source areas, in a PSVR prior to the scheduled timeframe of 2006 (FFA schedule). * Complete an ESD or a ROD amendment to address bypass of the air stripper treatment system.

Operations and Maintenance* Protect drain lines from damage with proper soil cover.* Install additional signage to prevent unauthorized off-Base excavation.* Evaluate the causes of lower flows in the HDUS drain sets using video logs and flow data. Access points at each drain line may be necessary to allow a video log and to obtain the flow data of each line. * Data from the sumps in Landfill No. 1 and the drain set flows of the HDUS system should be included in the ERPIMS database to allow for trends to be examined. All data that are required in the PSVP should be included in the database. If no data are available during a sampling round, or if a point has been discontinued, it should be noted in the database for clarification.* In the case of a change of circumstances (flow rates, land use, land ownership, land access, etc.), surface water controls will need to be reevaluated and implemented.* Complete a risk-based analysis for seep U4-308 and if risk-based levels are exceeded, institutional controls should be enforced.

X. Protectiveness Protective in the short-term


The remedies at LF011 currently protect human health and the environment. There is no immediate risk to human health and the environment at this site. This, however, is not due to the implementation of the groundwater remedy at the site, but is due to institutional controls and the lack of receptors. Increasing concentrations observed in some monitoring wells indicate the potential for plume migration. If plume migration does occur, completion of an exposure pathway is possible, causing potential risk to human health and the environment. Also, within the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at this site. Therefore, a re-evaluation of potential risk at LF011 must be conducted before the long-term protectiveness of the current remedies can be determined.






2008






III. Background Landfill No. 2 is located along the top of a steep, terraced, escarpment of the Weber Delta looking on to the Weber River Valley. Beyond the Base boundary, the hill continues downward and seeps have been observed flowing out of the hillside. The Davis-Weber Canal, a privately-owned irrigation canal used each year from April to October, is in the middle of the slope. Results of analyses of canal water during the RI indicated that the canal has not been a source of contamination, nor have chemicals from OU 4 contaminated it. Beyond the slope, there are houses and small farms.

Landfill No. 2 was operated between 1963 and 1965, when it was officially closed. "General waste" was dumped down the side of the hill and periodically burned. No records have been found indicating that industrial or hazardous wastes were disposed of at this site.

Evaluations of data collected during 1992 confirmed that Landfill 2 was not a source area of TCE or other contaminants. Landfill No. 2 has NFRAP status (HAFB EMR 1994) and no further investigations are required. It was suggested in the ROD that Landfill No. 1 is the sole source of the TCE contamination area. However, elevated and slowly escalating levels of contamination, limited to a small area, have been discovered near the Landfill No. 2 area since the ROD was written.


Not applicable.


I. Introduction Landfill No. 2, IRP site LF012, is located in the northeastern part of Hill AFB at the northern boundary (see Figure OU 4-1). Early sampling results indicated that the site does not pose a threat to human health and the environment. The ROD states that Landfill No. 2 is "not a source of contamination" (HAFB EMR 1994), referring to evaluations in the Addendum RI (USGS 1993). Therefore, no further investigation nor remedial action was required (HAFB EMR 1994).

In 1996, an area of elevated TCE concentration was discovered at well U4-080 (3,770 ug/L in 2002), indicating a possible source down-slope of Landfill No. 2, near the northwest end of one of the North Gate Dump areas. The source of this high TCE contamination has not been determined.




NA







2008


LF012 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b).


Question A (Answer)

Not Applicable


Not applicable.

Question B (Answer)

Not Applicable

Question B (Comment) Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues * An additional source of contamination is suspected near the Landfill 2 and North Gate Dump Areas.

IX. Recommendations * Continue to monitor wells in the OU 4 plume area. If a sustained increase in contaminant trends and an expansion of plume boundaries are observed, an evaluation should be completed to determine if additional source area characterization is warranted.



Investigations indicate that LF012 does not pose a threat to human health and the environment and no further action was approved in the 1994 ROD (HAFB EMR 1994). However, concerns about potential sources of contamination need to be investigated and therefore this IRP site needs to be reviewed again in 2008.





OU 4 OT020 SPOIL PIT


III. Background The Spoils Area is located along the top of a steep, terraced, escarpment of the Weber Delta looking on to the Weber River Valley. Beyond the Base boundary, the hill continues downward and seeps have been observed flowing out of the hillside. The Davis-Weber Canal, a privately-owned irrigation canal, used each year from April to October, is in the middle of the slope. Beyond the slope, there are houses and small farms.

The Spoils Area was operated as a disposal site from 1972 until 1989. It received construction debris (concrete, wood, and soil) from base activities. A soil gas survey at OT020 was conducted in November 1988 and found trace amounts of contaminants. In 1989, a well was installed immediately downgradient of the site (U4-027). Analysis of groundwater samples from this monitoring well reported no compound detected above groundwater standards. NFRAP status for the Spoils Area was accepted in 1992 before the completion of the ROD.


Not applicable.


OT042 was not specifically reviewed in the 1998 Five-Year Review Report (HAFB EMR 1998b).




I. Introduction Site OT020, also known as the Spoils Area or Spoils Pit, is located near the northern boundary of Hill AFB, at the east corner of the intersection of Browning Avenue and Foulois Drive (see Figure OU 4-1). Sampling results indicated that the site did not pose a threat to human health and the environment, and no further action was required at Site OT020 (Hirschi, S. 1992). Therefore, the Spoils area was not included in the ROD for OU 4 and no remedial action was required. This site is included in the 2003 Five-Year Review for completeness to document the site background.








OU 4 OT020 SPOIL PIT



Question A (Answer)

Not Applicable


Not applicable.

Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues None.




Investigations indicate that OT020 does not pose a threat to human health and the environment and no further action was approved in 1992 (Hirschi, S. 1992).




OU 4 OT041 NORTH GATE DUMP OP UNIT 4


III. Background The North Gate Dump area is located along the top of a steep, terraced escarpment of the Weber Delta overlooking the Weber River Valley. Beyond the Base boundary, the hill continues downward and seeps have been observed flowing out of the hillside. The Davis-Weber Canal, a privately-owned irrigation canal, used each year from April to October, is in the middle of the slope. Results of analyses of canal water during the RI indicated that the canal has not been a source of contamination, nor have chemicals from OU 4 contaminated it. Beyond the slope, there are houses and small farms.

Extensive analytical testing was completed in 1992 at the North Gate Dump. Concentration gradients of TCE in the unsaturated zone in these areas suggest that the TCE was derived from contaminated groundwater that migrated from Landfill 1. At that time, the North Gate Dump was not considered a source of TCE or other contaminants. NFRAP status for the North Gate Dump was accepted in 1994 (HAFB EMR 1994) and no further investigations are required.


I. Introduction The North Gate Dump is located in two areas. The first area is located along Foulois Drive, and the second is near a segment of Perimeter Road along the northern Base fence perimeter (see Figure OU 4-1). Early sampling results indicated that the site did not pose a threat to human health and the environment. The ROD states that the North Gate Dump Area is "not a source of contamination" (HAFB EMR 1994), referring to evaluations in the Addendum RI (USGS 1993). Therefore, no further investigation nor remedial action was required.

In 1996, an area of elevated TCE concentration was discovered at well U4-080 (3,770 ug/L in 2002), indicating a possible source near the northwest end of one of the North Gate Dump Areas, down-slope of Landfill 2. The source of this high TCE contamination has not been determined.

It was suggested in the ROD that Landfill 1 is the sole source of the TCE contamination in the OU 4 contamination plume. However, elevated and slowly escalating levels of contamination, above the 1,000 ug/L level, have been discovered near the North Gate Dump areas since the ROD was written. The increase in TCE concentrations measured in monitoring well U4-062, after Landfill 1 was capped, suggests that an additional source may be present in the North Gate Dump Areas just above the Davis-Weber Canal (see Figure OU 4-1). There is no documentation of dumping in that area but it has been suggested that drums containing solvents and other material were disposed during unauthorized dumping episodes at various sites along Perimeter Road (JS/I 2002).



NA






Not applicable.




Question A (Answer)

Not Applicable


Not applicable.

Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues * An additional source of contamination is suspected near the North Gate Dump Areas (OT041) and Landfill 2 (LF012). * There is the possibility of an additional source near the HDUS system.

IX. Recommendations * Conduct an investigation to determine the source(s) of additional contamination near the North Gate Dump areas.



Investigations indicate that OT041does not pose a threat to human health and the environment and no further action was approved in the 1994 ROD (HAFB EMR 1994). However, concerns about potential sources of contamination need to be investigated and therefore this IRP site needs to be reviewed again in 2008.









2008




OU 4 OT042 MUNITIONS DUMP OP UNIT 4

II. Site Chronology Please see Table OU 4-2 for a history of events at this site. The table is organized to first describe events which impacted the whole OU, followed by events impacting only specific IRP sites within the OU.

III. Background The Munitions Dump is located along the top of a steep, terraced escarpment of the Weber Delta overlooking the Weber River Valley. Beyond the Base boundary, the hill continues downward and seeps have been observed flowing out of the hillside. The Davis-Weber Canal, a privately-owned irrigation canal used each year from April to October, is in the middle of the slope. Beyond the slope, there are houses and small farms.

The Munitions Dump was operated by the Ogden Arsenal as an above-ground storage area for munitions during World War II. Spent shell casings were observed in the area during the site classification activities at OU 4. Evaluation of data collected during 1992 confirmed that the Munitions Dump is not a source area of TCE or other contaminants. NFRAP status for the Munitions Dump was accepted in 1994 (HAFB EMR 1994) and no further investigations are required.


Not applicable.




Question A (Answer)

Not Applicable



I. Introduction The Munitions Dump was located near the North Gate boundary at Hill AFB (see Figure OU 4-1). The ROD states that the Munitions Dump is "not a source of contamination" (HAFB EMR 1994). Therefore, no remedial action nor further investigation was required. This site is included in the 2003 Five-Year Review for completeness and to document the site background.




NA





OU 4 OT042 MUNITIONS DUMP OP UNIT 4




Not applicable. There are no remedies associated with this site.

Question B (Answer)

Not Applicable


Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues None.




Investigations indicate that OT042 does not pose a threat to human health and the environment and no further action was approved in the 1994 ROD (HAFB EMR 1994).




Operable Unit 5

I Introduction

OU 5 is located along the northwestern boundary of Hill AFB. It includes three IRP sites (see Table OU 5-1) that encompass contaminated soil and groundwater on- and off-Base. There is currently no ROD in place for OU 5. Bamberger Pond (site SD016) has been designated as a site with no further remedial action planned (HAFB EMR 2000) and has been included here only for completeness and to document site background information. The other two IRP sites that are active are the subject of this FYR and include; the US Army Tooele Rail Shop (TARS) site containing what is commonly referred to as the TARS plume and the Building 1607-Evaporation Pond site (site SS091), containing what is commonly referred to as the Zone 16 plume (site SS017). The TARS plume consists of contaminated soil on-Base, and contaminated groundwater originating on-Base and continuing west off-base beneath the cities of Sunset and Clinton. This site has two operating, early action remedial systems, an air sparge system and a groundwater extraction system. A third early action is under construction that is designed to limit the migration of contaminated groundwater into the city of Clinton. The Zone 16 plume also originates on-Base and in part commingles with the TARS plume and continues off-Base in a separate plume to the north beneath the cities of Sunset and Clinton. The locations of the active IRP sites are shown in Figure OU 5-1. Table OU 5-1. OU 5 Site Identification

Site ID Site Name SD016 BAMBERGER POND SS017 US ARMY TOOELE RAIL SHOP SS091 BLDG 1607 - EVAP. POND

II Site Chronology


III Background

OU 5 initially included only the TARS plume and Bamberger Pond. A remedial investigation was completed in 1995. The feasibility study was in its draft version in 1999 when further investigations, performed for the OU 9 North Area Site Investigation, discovered additional groundwater in the OU 5 area that had been contaminated with TCE and other VOCs. This newly discovered contamination was referred to as the Zone 16 plume (SS091) (MWH 2002a). Its discovery prompted reopening of the OU 5 RI in 1999. Bamberger Pond is an unlined storm-water runoff holding system located on the west side of Hill AFB just south of the West Gate and was included in the original IRP program because of nearby historical industrial activities. Elevated concentrations of arsenic and manganese in groundwater beneath Bamberger Pond were identified. However, through extensive investigation and research, it was determined that contaminant concentrations are a result of naturally occurring processes (URS 2000).


The TARS area includes a rail shop, a former Base housing area, and the footprint of a former wastewater treatment system. Groundwater contamination associated with the rail shop (constructed to service and repair railroad engines for the military) is present in the shallow aquifer and extends off-Base beneath commercial and residential areas. The groundwater is not used for drinking water, however, there are three known non-culinary users of the groundwater who have been provided with city water by Hill AFB.

The Zone 16 Complex area (which includes Building 1607) is located east of the TARS area and is currently used for missile testing, research and maintenance; historically it was the former West Fuze Plant which manufactured bombs and other munitions. Degreasing solvents likely were associated with the activities at these facilities. Shallow groundwater contamination associated with solvent use has migrated off-Base beneath commercial and residential areas.

IV Remedial Actions

Early remedial actions have been implemented at OU 5 to address off-Base groundwater contamination. The RI for OU 5 is not yet complete, however, numerous contaminants have been identified in the groundwater above their associated MCLs and are presented in the individual site summaries (see Section XIII). The early action remedial systems were primarily designed for the removal of groundwater contaminated with TCE. The following remedial action objectives for OU 5 are taken from the 1996 Action Memorandum for OU 5 (Radian Int’l 1996), and apply to all OU 5 early remedial actions performed under the OU 5 Engineering Evaluation/Cost Analysis: • To reduce or eliminate releases and potential releases of contaminated groundwater flow

through seeps and springs. • To prevent further groundwater degradation from uncontrolled movement of the existing

plume. • To reduce the spread of contamination to currently unaffected residents. • To prevent and minimize the effect of contaminant releases on the welfare of residents living

in Sunset and Clinton. • To support and complement the overall remediation strategy considered in the feasibility

study for OU 5. Two early action remedial systems have been constructed to mitigate off-Base plume migration at site SS017. These were implemented in two phases, phase I constructed an aeration curtain and phase II a groundwater extraction system (see Figure OU 5-1). A third early action remedial system (a groundwater extraction trench) for site SS017 is in the final stages of construction and is planned to begin operation in the spring of 2003. No remedial actions are in place at site SS091.

V Progress Since Last Five-Year Review Four areas of progress have been made at OU 5 since the last FYR (HAFB EMR 1998) and they

include:

1. A NFRAP was completed for Bamberger Pond (SD016).


2. The soil vapor extraction system at the phase I aeration curtain was taken off-line in September 2000, with concurrence from regulators (Torres, O. 2003).

3. A Remote Data System (RDS) to monitor the treatment systems was completed and installed in 2002 at the Phase I and Phase II systems.

4. The OU 5 RI was reopened and will be completed by June 2003. VI Five-Year Review Process

Site review was conducted per the process described in this report for the overall 2003 FYR. VII Technical Assessment

Results of the technical assessment for each site in OU 5 and for the operable unit as a whole are listed in Table OU 5-3. Details of the technical assessment for each site in OU 5 are provided in the respective site summary (see Section XIII).




Year Review

SD016 Not required, NFRAP site NA NA NA NA Not

required

SS017

Phase I: aeration curtain &

groundwater use restrictions

Yes Yes Yes Protective in the short-term 2008

SS017

Phase II: groundwater

extraction system & groundwater use

restrictions

No, not capturing

the 100 ppb contour plume

Yes Yes Protective in the short-term 2008

SS017

Phase III: groundwater

extraction trench (not operational at this

time) & groundwater use restrictions

NA NA NA Protective in the short-term 2008

SS091

No remedial actions are in-place at this

time & groundwater use restrictions

NA NA NA NA 2008

OU 5

Aeration curtain, groundwater extraction &

groundwater use restrictions

No Yes Yes Protective in the short-term 2008






It should be noted that the remedies for OU 5 refer to early actions and not final remedies. The NA designation in Table OU 5-3 indicates either that no remedy is required (SD016) or that the remedy is not yet operational (SS017, Phase III), or has not yet been selected (SS091).

Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives (RAOs) used at the time of the remedy still valid?

The exposure assumptions, toxicity data, and cleanup levels are undergoing evaluation as part of the current RI activities being conducted for OU 5. The RAOs (presented here in Section IV) for early action remedies associated with OU 5 are general and do not define clean-up standards. Therefore, these RAOs are still valid. Furthermore, the Utah and Federal drinking water standard for TCE of 5 µg/L, which was used as a design parameter for the aeration curtain, is still valid.

Question C. Has any other information come to light that could call into question the protectiveness of the remedy?

See Sections VIII and IX for details. VIII Issues

Based on the information reviewed and interviews and inspections conducted, issues that may affect protectiveness of the selected remedies at OU 5 are listed below:

1. The blowers in the site SS017 Phase I aeration curtain fail approximately every 2 years and

the sparge pipes have clogged intermittently since construction. Currently, the aeration curtain is allowing concentrations of TCE greater than 5 µg/L to pass through.

2. The site SS017 Phase I blower building overheats in the summer, causing the system to periodically shut down (Knutson, S., 2003).

3. The site SS017 Phase II groundwater extraction system does not appear to meet its RAO of containing the 100 parts per billion (ppb) contour. In addition, analysis of future mass removal predicts that the Phase II system will remove less than another 1% of the OU 5 dissolved contaminant mass over the next 30 years (MWH 2002a).

4. The 5 to 100 µg/L portion of the TARS plume has passed the location of the site SS017 Phase III groundwater extraction trench and therefore will not be treated by any systems currently designed. However, EMR has indicated that preliminary RI modeling (to be completed the summer of 2003) suggests that this portion of the plume will only persist for approximately 15-20 years after start-up of the Phase III trench.

5. There has been no published evaluation of indoor air quality in residences above the plumes. However, according to EMR, the Draft RI, to be completed the summer of 2003, includes indoor air sampling that indicates indoor air is not a problem.




1. Evaluate the life expectancy of the site SS017 Phase I (aeration curtain) system and if appropriate replace the blowers with an air compressor.

2. Clean the site SS017 Phase I (aeration curtain) sparge lines and develop a preventive maintenance process to prevent unplanned system shutdowns in the future.

3. Increase ventilation in the site SS017 Phase I (aeration curtain) blower building.

4. Shut down the site SS017 Phase II (groundwater extraction) system.

5. Continue all institutional controls, primarily, groundwater-use restrictions on the shallow aquifer beneath sites SS017 and SS091 (HAFB 1998).


Activities at OU 5 are protective of human health in the short-term, due to restrictions on the use of contaminated groundwater beneath the current plumes. The RAOs for OU 5 are not intended to protect overall human health and the environment but are directed toward slowing migration of contamination until a permanent remedy can be installed. The site SS017 Phase I (aeration curtain) early action remedy has a very high cleanup efficiency (averaging greater than 92%) and is reducing contaminant levels as intended and, therefore, is meeting the RAOs at this time. However, it is not currently remediating the groundwater that passes through it to below MCLs (as designed). The site SS017 Phase II (groundwater extraction) system does not appear to meet RAOs. Currently, concentrations in the groundwater downgradient of the trench (see Figure OU5-1) are between 5 and 100 µg/L. According to modeling conducted for Hill AFB (MWH 2002d), contamination at these concentrations will remain in the groundwater for between 20 and 30 years. There is no remedy in place for the contaminant plume associated with SS091. An OU 5 RI is in the final stages of completion to be followed by a feasibility study, ROD, and presumably remedial designs to permanently address protectiveness of human health and the environment at OU 5.

XI Next Review

The next review for OU 5 is required by 2008. No future review is required for Bamberger Pond (SD016) because no further remedial action is planned at this site.


(HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 2000) Bamberger Pond NFRAP Action Memorandum, Hill AFB EMR, June 2000. (Knutson, S. 2003) Knutson, S., O&M Contractor, URS, Personal Communication, 12 February 2003.


(MWH 2001) Performance Standard Verification Plan For Phase III EE/CA, Operable Unit 5, Montgomery Watson Harza, October 2001. (MWH 2002a) Final Conceptual Model for Operable Units 5 and 12, Montgomery Watson Harza, September 2002. (MWH 2002b) Engineering Evaluation and Cost Assessment (EE/CA) Addendum For Operable Unit 5, Montgomery Watson Harza, January 2002. (MWH 2002c) Final Operable Units 5 and 12 Historic Site and Source Area Review, March 2002, Montgomery Watson Harza, March 2002. (MWH 2002d) Final Contaminant Transport Model Report for Operable Units 5, Montgomery Watson Harza, February 2002. (Radian 1995a) Baseline Risk Assessment Operable Unit 5 Sites SS17, SD16 Executive Summary, Radian, February 1995. (Radian Int'l 1996) Action Memorandum Operable Unit 5, Hill AFB, Radian International, March 1996. (Torres, O. 2003) Torres, O., Project Manager, Hill AFB EMR, Personal Communication, 06 February 2003. (URS 2000) Final Fate and Analysis of Arsenic and Manganese in the Vicinity of Bamberger Pond, URS Radian International, June 2000.



OU 5 OPERABLE UNIT 51986 Field work began as part of the

Installation Restoration ProgramField work was conducted at the Tooele Army Rail Shop and Bamberger Pond.

Remedial Investigation Report Operable Unit 5 Sites SS17, SD16 Volume 1 - Text

1987 Trace quantities of trichloroethene and 1,1,1-trichloroethane were found in two residential wells and a spring located off-Base

The wells and spring were located in the cities of Sunset and Clinton approximately 1 mile west of the Base. Monitoring wells were installed and soil and groundwater samples were collected at these sites from 1989 through 1991. This would become Site SS017.


01 1988 Installation Restoration Program, Phase II Confirmation/Qualification Stage 2 completed

Identified the Tooele Army Rail Shop area and Bamberger Pond as potential sources of contamination.

Action Memorandum Operable Unit 5, Hill AFB

1992 RI work began OU 5 Remedial Investigation activities commenced for Sites SS017 and SD016.

Draft Conceptual Model for Operable Unit 5, May 2001

08 1994 Final Environmental Assessment, Operable Unit 5, Sites SS017, SD016

Discusses the environmental impacts of the OU 5 aeration curtain treatability study, the feasibility study pumping test, and the Engineering Evaluation Cost Analysis removal actions. No environmental impacts were expected from these activities.






12 1994 Final Engineering Evaluation and Cost Analysis for Operable Unit 5 completed

This document outlined five early actions to be implemented in phases at OU 5. The fourth (pertaining to an area now part of Zone 16) and fifth (having to do with Bamberger Pond) phases were not implemented.

Engineering Evaluation/Cost Analysis Operable Unit 5

02 1995 Final Baseline Risk Assessment. Operable Unit 5, Sites SS017, SD016

This Risk Assessment will be superseded or have an addendum in 2003 which will address the additional areas (Zone 16 plume) discovered and addressed under the reopened Remedial Investigation.

Baseline Risk Assessment Operable Unit 5 Sites SS17, SD16 Executive Summary

05 1995 Final Remedial InvestigationI Report for OU5, Sites SS017 and SD016 completed

Although this Remedial Investigation is titled 'Final' it was reopened in 1999 due to the discovery of further contamination (Zone 16 plume).


03 1996 Final Action Memorandum Operable Unit 5 completed

This document provides support and justification for implementing the early removal actions described in the Engineering Evaluation Cost Analysis.


05 1996 Draft Final Feasibility Study, Operable Unit 5 completed

This feasibility study will be superseded by the Remedial Investigation and Feasibility Study, which was reopened in 1999 and is still ongoing.

Draft Final Feasibility Study, Operable Unit 5





01 1999 Remedial Investigation Reopened Investigations performed throughout OU 9 between 1996 and 1998 identified the existence of a volatile organic compound groundwater plume substantially larger than that addressed in the 1995 RI. This plume became IRP site SS091, also known as the Zone 16 plume. The final remedial investigation is not complete as of Jan. 2003, but a draft document is anticipated in mid-summer 2003.


10 2001 Final Conceptual Model for Operable Unit 5 completed

This document presents a conceptual model for the fate and transport of contaminants in groundwater at OUs 5 and 12.

Final Conceptual Model for Operable Unit 5, Oct. 2001

10 2001 A northern groundwater contamination plume within OU 5 was discovered and split from OU 5 to make OU 12

This plume was discovered during additional environmental investigations in 2000.


01 2002 Final Engineering Evaluation and Cost Assessment Addendum for Operable Unit 5 completed

Addresses changes in Phase III of the original Engineering Evaluation Cost Analysis and deleted Phases IV and V from actions to be completed..

Engineering Evaluation and Cost Assessment (EE/CA) Addendum For Operable Unit 5

SD016 BAMBERGER POND06 2000 Bamberger Pond No Further

Response Action Planned Action Memorandum completed

Provides a document that the State agreed with, stating that the Bamberger Pond site requires no further remedial action.

Bamberger Pond NFRAP Action Memorandum





06 2000 Final Fate and Analysis of Arsenic and Manganese in the Vicinity of Bamberger Pond completed.

This document analyzes arsenic and manganese in the vicinity of Site SD016 and provides evidence that elevated concentrations of both are a result of naturally occurring processes.

Final Fate and Analysis of Arsenic and Manganese in the Vicinity of Bamberger Pond

SS017 US ARMY TOOELE RAIL SHOP1991 Soil-gas survey performed at the

Tooele Army Rail ShopAs a result, two underground fuel storage tanks at Building 1705 at the Tooele Army Rail Shop were removed and limited petroleum hydrocarbon contamination in soil was removed.


05 1997 Installation of Sparge Curtain complete and operation begins

The sparge curtain is Phase I of five phases recommended in the original Engineering Evaluation Cost Analysis as early actions.


09 1997 Installation of Groundwater Extraction System

The Groundwater Extraction System is Phase II of five phases recommended in the original Engineering Evaluation Cost Analysis as early actions. Operation began in November 1997.


1999 Sparge lines and gravel pack for the Phase I Aeration Curtain were cleaned

System was experiencing operational problems with the sparge blowers due to excessive backpressure from the sparge lines due to sediment in the trench.






10 2001 Performance Standard Verification Plan for Phase III EE/CA, Operable Unit 5 completed.

Defines the tools and procedures necessary to demonstrate progress towards or attainment of performance objectives established for the Phase III early action, consisting of a groundwater extraction trench, which was installed October 2002 through April 2003.

Performance Standard Verification Plan For Phase III EE/CA, Operable Unit 5

SS091 BLDG 1607-EVAP. POND1998 Zone 16 Plume discovered Investigations performed throughout OU 9 between 1996 and

1999 identified a volatile organic compound groundwater plume in OU 5 larger than that originally identified in the 1995 remedial investigation. This became known as the 'Zone 16' plume and was labeled site SS091.

Final Conceptual Model for Operable Units 5 and 12




OU 5 SD016 BAMBERGER POND


III. Background Bamberger Pond is a stormwater runoff holding system consisting of two separate, unlined basins 50 to 100 feet wide and 600 to 800 feet long that connect with a culvert drain. It was built in 1941 and is located on the west side of Hill AFB just south of the west gate and west of 6th Street (see Figure OU 5-1). It is still being used to contain stormwater runoff.

Elevated concentrations of arsenic and manganese in groundwater beneath Bamberger Pond were originally thought to be a result of Base activities. However, through extensive investigation and research, it was determined that concentrations were a result of naturally occurring processes associated with the geochemical stability of the aquifer (URS 2000). Therefore, the EPA and the UDEQ concur that there be No Further Response Action Planned for Bamberger Pond (Site SS016).


Not Applicable. No remedial action required at this site due to NFRAP status.


This site was mentioned in the 1998 Five-Year Review (HAFB EMR 1998); however, no specific recommendations were made. Since the 1998 FYR, Bamberger Pond (SD016) was removed from further IRP investigations and accepted by the regulatory agencies as a closed CERCLA site requiring no further action.


Question A (Answer)

Not Applicable



I. Introduction Site SD016 is included in OU 5 and is comprised of Bamberger Pond. This site currently has a No Further Response Action Planned status (HAFB EMR 2000). Therefore, no remedial action is required at the site. This site is included in the 2003 Five-Year Review for completeness to document the site background.



GW NA NA

* Not Applicable. No further remedial action planned.




OU 5 SD016 BAMBERGER POND




There are no remedies associated with this site because it has been determined that no further action is necessary. The Site has NFRAP status.

Question B (Answer)

Not Applicable

Question B (Comment) There are no remedies associated with this site because it has been determined that no

further action is necessary. The site has NFRAP status.

Question C (Answer)

Not Applicable


There are no remedies associated with this site because it has been determined that no further action is necessary. The site has NFRAP status.

VIII. Issues None.




Bamberger Pond (SD016) was recommended for NFRAP status and accepted in 2000 because there is no evidence of hazardous substances or petroleum products being released, stored for one year or more, or disposed of in or around Bamberger Pond (URS 2000).




OU 5 SS017 US ARMY TOOELE RAIL SHOP


III. Background The US Army Tooele Rail Shop (also known as the Tooele Army Rail Shop) area is located along the northwestern edge of the Base (see Figure OU 5-1) and includes a rail shop, a former Base housing area, and the footprint of a former wastewater treatment system. The area to the east of the rail shop is generally undeveloped within about half a mile. The Base boundary, rail lines, Davis-Weber Canal, Interstate Highway 15, and Main Street in Sunset City are located to the west of the rail shop (see Figure OU 5-1).

Groundwater contamination associated with the Tooele Army Rail Shop (constructed in 1942 and upgraded in 1944 to service and repair railroad engines for the military) is present in the shallow aquifer. The TARS groundwater plume commingles with the Zone 16 (Site SS091) plume on-Base and then separates and extends approximately one mile beyond the boundary of Hill AFB under the communities of Sunset and Clinton. An open area immediately west of the rail shop was formerly used for cleaning large train parts. Trichloroethene reportedly was used for this purpose during the period of 1959-1964. Building 1712 was constructed over this area in the late 1980s. Prior to 1979, runoff from a steam cleaning system at the rail shop flowed into a drainage grate which fed an in-ground oil-water separator. Hill AFB drawings indicate the storm drain lines extended directly north from the oil-water separator and the rail shop, parallel to the rail lines, and terminated at a gravel drain/sump approximately 1,000 feet north of building 1701, adjacent to building 1723A. These drain lines likely played a key role in the off-base migration of contaminants. In 1979, the cleaning system was redesigned to collect runoff into a new oil-water separator that discharges water to the Base Industrial Wastewater Treatment Plant.

An Engineering Evaluation and Cost Analysis was completed for OU 5 (including this site) in 1994 and outlined five phases of early actions to address contaminated groundwater. Phase I (aeration curtain) and Phase II (groundwater extraction system) have been in operation since 1997. Phase III (groundwater extraction trench) was redefined in a 2002 EE/CA Addendum and is currently under construction. Phases IV and V were deleted in the 2002 EE/CA Addendum. See Figure OU 5-1 for the locations of these systems. An RI and draft FS were completed in 1995. However, further groundwater contamination was discovered in 1999 (now known as the Zone 16 Plume, SS091) causing the OU 5 RI to be re-opened. The re-opened RI will be complete by June 2003. No ROD exists for this site, but there is a 1996 Action Memorandum and 2002 Action Memorandum Addendum authorizing construction of three phases of early actions.

I. Introduction Site SS017, located on the western boundary of Hill AFB, contains a contaminated groundwater plume referred to as the TARS plume. The re-opened Remedial Investigation for OU 5 is scheduled to be complete by mid-summer 2003. Two Early Actions, consisting of an aeration curtain (Phase I) and a groundwater extraction system (Phase II) currently exist on site and a third, a groundwater extraction trench (Phase III), is in the final stages of construction. Restrictions on future use of the shallow contaminated groundwater from this site are in place and former users of this water have been placed on city water.





Groundwater-use restrictions are in place that preclude the use of groundwater from the shallow aquifer beneath OU 5.


No ROD exists for this site. However, there are three early removal actions:

Phase I Aeration Curtain:The Aeration Curtain consists of an air sparge (AS) system and a soil vapor extraction system which consist of two sparge blowers, two SVE blowers, an inlet separator, a heat exchanger, sparge and SVE piping, and a blower building. These systems are connected to a trench approximately 400 feet long, 30 feet deep, and 3 feet wide that runs north to south on the east side of Main St. in Sunset, UT. The aeration curtain was installed to intercept contaminated groundwater traveling west from Hill AFB and treat it in situ by blowing air from the pipes at the bottom of the trench through the contaminated groundwater, stripping TCE in the process. It has been in operation since May 1997.

Phase II Groundwater Extraction System:The GES consists of five extraction wells, five piezometers, and piping to pump groundwater to a sanitary sewer manhole for treatment by the North Davis County Sewer District (NDCSD). The system is located at 2125 N. 55 W. (approximately one block west of Main Street) in the City of Sunset, UT. The system was installed to provide capture of the >100 ppb TCE portion of the contaminated groundwater plume downgradient of the




GW 1,1,1-TRICHLOROETHANE No number specified, see RAOs

GW 1,1-DICHLOROETHENE No number specified, see RAOs

GW cis-1,2-DICHLOROETHENE No number specified, see RAOs

GW PERCHLORATE No number specified, see RAOs

GW TETRACHLOROETHENE(PCE) No number specified, see RAOs

GW TRICHLOROETHENE (TCE) No number specified, see RAOs

GW VINYL CHLORIDE No number specified, see RAOs

* To support and complement the overall remediation strategy considered in the feasibility study for OU 5.* To prevent further groundwater degradation from uncontrolled movement of the existing plume.* To reduce the spread of contamination to currently unaffected residents.

* To prevent and minimize the effect of contaminant releases on the welfare of residents living in Sunset and Clinton.* To reduce or eliminate releases and potential releases of contaminated groundwater flow through seeps and springs.





aeration curtain. It has been in operation since November 1997.

Phase III Groundwater Containment System:Construction of this system is in its final stage and will be operational in April 2003. The system is located at 550 W and 2250 N in the City of Clinton, UT and is comprised of a groundwater extraction trench and a downgradient slurry wall.


During the last Five-Year Review in 1998 (HAFB EMR 1998), no specific recommendations were made for site SS017. However, it was mentioned that a study was being conducted to evaluate conversion of the aeration curtain to a groundwater extraction system. This conversion has not been made due to economic reasons and the aeration curtain is still performing to meet RAOs. Since the last FYR, the soil vapor extraction system has been turned off (in September 2000), with concurrence from regulators (Torres, O. 2003), because TCE concentrations were not detected in the collected vapor. A Remote Data System to monitor the treatment systems was completed in 2002. The location proposed for the Phase III Groundwater Extraction Trench at the time of the last FYR has been changed from the City of Sunset to the City of Clinton (see Figure OU 5-1 for current location). The OU 5 RI has been reopened and is estimated to have a draft complete by mid-summer 2003.


Question A (Answer)

No


Phase I (aeration curtain): The system still appears to be meeting the RAOs (by controlling the movement of the plume and reducing the spread of contamination) and is operating at an average efficiency of greater than 92%. However, the system is not currently functioning as designed (concentrations of TCE greater than 5 ug/L are passing through the curtain) due to blower failures and sparge pipe clogging, which reduce efficiency and, if not rectified, may cause the system to no longer function as intended. Historically, when the aforementioned problems were not occurring, the system functioned at or above its design specifications.

Phase II (groundwater extraction system): This system is not capturing the plume as originally designed and is not functioning as intended.

Question B (Answer)

Yes

Question B (Comment) The RAOs (presented here in Section III) for these early action remedies are intended to

mitigate the plume until long-term remedial actions are implemented and do not define clean-up standards. The RAOs are still valid. The Utah and Federal drinking water standard for TCE of 5 ug/L, which was used as a design parameter for the aeration curtain, is also still






valid. The MCLs used to determine contaminants of concern are also still valid.

Question C (Answer)

Yes


Phase I (aeration curtain): According to interviews conducted for this review with Oscar Torres, Mark Loucks, Curt Himle, Steve Knutson, and Tyler Esplin, there are several equipment problems (sparge blowers fail approximately every two years and continually leak oil, and the sparge lines clog intermittently). At the time of inspection, only one blower was operable. These problems will affect the system's efficiency and potentially could jeopardize the ability of the system to meet RAOs. The last two quarters of 2002 showed that all of the wells downgradient of the aeration curtain had TCE levels above the MCL of 5 ug/L. Prior to this, since the system started operation, downgradient concentrations were below 5 ug/L.

Phase II (groundwater extraction system): According to interviews and contaminant contour maps, this system is no longer preventing migration of the contaminant plume or removing significant mass. The system will be recommended for shutdown in the upcoming FS because it is not achieving its goal and the predicted TCE mass removal over the next 30 years will only increase by one percent from the mass currently removed.

VIII. Issues *Currently, the aeration curtain is allowing concentrations of TCE greater than 5 ug/L to pass through.*The Phase II groundwater extraction system does not appear to be affecting the plume and is predicted to only remove another one percent of contaminant mass over the next 30 years.*The 5 to 100 ug/L portion of the plume has passed the location of the Phase III groundwater extraction trench and therefore will not be treated by any systems currently designed. However, EMR has indicated that preliminary RI modeling (to be completed the summer of 2003) suggests that this portion of the plume will only persist for approximately 15-20 years after start-up of the Phase III trench.*According to documents included in this review (those published up to September 2002), there has been no evaluation of indoor air quality in residences along the plume. However, according to EMR, an indoor air evaluation is being conducted as a part of the re-opened RI.OPERATIONAL PERFORMANCE ISSUES:*Phase I aeration curtain equipment: the blowers fail every two years; the sparge pipes have clogged intermittently since construction; and the blower building overheats in the summer, causing the system to periodically shut down (Knutson, S. 2003).*Efficiency of the Phase I aeration curtain is calculated using concentrations from a set of wells that are not all directly up and downgradient of one another or the aeration curtain. It is not immediately apparent how this combination would effect the efficiency calculation, however, it appears that the calculation does not give a true representation of the aeration curtain efficiency.






2008

IX. Recommendations Phase I (aeration curtain): *Evaluate the life expectancy of the system and consider replacing the blowers with an air compressor if appropriate*Clean the sparge lines and develop a preventive maintenance process to prevent unplanned system shutdowns*Increase ventilation in the blower building*Use only up and downgradient well pairs in the efficiency calculation

Phase II (groundwater extraction system): * Shut down system

Generally:*Continue with groundwater use restrictions on the shallow aquifer

X. Protectiveness Protective in the short-term


Due to the restrictions on the use of contaminated groundwater beneath the current plume, the early actions associated with SS017 are protective in the short-term. Although the Phase I early action remedy appears to be meeting the RAOs at this time, it is not currently remediating the groundwater to below MCLs (as it was designed to do). Additionally, the current RAOs for this site are not intended to protect overall human health and the environment, but only to minimize the migration of contamination. The Phase II groundwater extraction system does not appear to meet the RAOs. The Phase III system is currently under construction and should help to minimize further migration of the portion of the plume greater than 100 ug/L into the city of Clinton. However, it appears that the 5 to 100 ug/L portion of the plume has already passed the Phase III location. According to modeling conducted for Hill AFB (MWH 2002d), contamination at these concentrations will remain in the groundwater for between 20 and 30 years.




OU 5 SS091 BLDG 1607-EVAP. POND


III. Background This site is referred to as the Zone 16 plume (also known as the Bldg. 1607-Evaporation Pond) with its suspected source area (Zone 16 Complex) being east of the Tooele Army Rail Shop (TARS) area (See Figure OU 5-1). This site was not identified during the original Remedial Investigation for OU 5 (Radian 1995). It was discovered during site inspection investigations performed for the OU 9 North Area and was delineated in March of 1999 (MWH 2002a). Its discovery prompted the reopening of the OU 5 RI in 1999.

The Zone 16 source investigation area is a series of buildings (buildings 1600-1609 within 1600 complex) currently used for munitions storage, and historically known as the West Fuze Plant in the 1940s. The contaminant plume commingles with the TARS plume on-Base and then continues off-Base, beneath the cities of Sunset and Clinton, in a discrete plume to the north of the TARS plume (See Figure OU 5-1 for details).

The Zone 16 area, located within the former West Fuze Plant, includes the Building 1607 Complex, which refers to the entire fenced area around this group of buildings including the former flash pond, and is believed to be a primary source area for groundwater contamination. Building 1607 was originally the Small Arms Repair Warehouse which became the Loading and Assembly Line Building. Degreasing solvents were likely associated with the activities conducted at these facilities.

Although the RI is not complete, and formal contaminants of concern or specific clean-up levels not yet identified, investigations have been completed that indicate the following contaminants exist in the groundwater above their associated maximum contaminant levels (MCLs): carbon tetrachloride, cis-1,2-dichloroethene, perchlorate, tetrachloroethene (PCE), and trichloroethene (MWH 2002b; MWH 2002c). It is likely that the formal COCs will include some or all of the aforementioned contaminants. EMR has indicated, in personal communications (Knutson, S. 2003; Torres, O. 2003), that ongoing data collection and modeling suggest the plume is stable.

The Remedial Action Objectives for this site are general OU 5 RAOs that could apply to this site if any early actions were taken prior to a Record of Decision.


I. Introduction Site SS091 (Building 1607-Evaporation Pond) is a part of OU 5, is comprised of contaminated groundwater, and is referred to as the Zone 16 plume. This plume was discovered in 1999 during investigations conducted for OU 9 and instigated the reopening of the OU 5 Remedial Investigation in 1999. The reopened RI for OU 5 will be complete in June 2003 (Loucks, M. 2003). No remedial actions, early actions, or interim actions currently exist on site.


GW NA - Remedial Investigation and Risk Assessment have not been completed; therefore, no CoCs are defined to date.

NA






No remedial actions are in place at this time. Site is still in the Remedial Investigation stage.


This site had not been established as an IRP site at the time of the last (1998) Five-Year Review.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable



Question C (Answer)

Not Applicable



VIII. Issues None.

IX. Recommendations *Continue with groundwater-use restrictions on the shallow aquifer.




* To prevent and minimize the effect of contaminant releases on the welfare of residents living in Sunset and Clinton.* To reduce or eliminate releases and potential releases of contaminated groundwater flow through seeps and springs.* To prevent further groundwater degradation from uncontrolled movement of the existing plume.* To reduce the spread of contamination to currently unaffected residents.

* To support and complement the overall remediation strategy considered in the feasibility study for OU 5.






2008


As there are no remedies in place at this time, a statement concerning protectiveness for SS091 is not applicable at this time. There are, however, restrictions on the use of contaminated groundwater present in the shallow aquifer beneath the current plume. Monitoring data should continue to be reviewed to ensure model accuracy. A remedial investigation is in the final stages of completion to be followed by a feasibility study, ROD, and presumably a remedial design to address human health and the environment.




Operable Unit 6

I Introduction

OU 6 is located in the northern portion of Hill AFB. It includes 3 IRP sites (see Table OU 6-1) and has active remediation systems in place to address contaminated groundwater and soil. The location of each IRP site is shown in Figure OU 6-1. These sites were investigated and are managed under OU 6 because of their proximity to each other. The Asphalt Pad site (OT026) consists of the larger east TCE contaminated groundwater plume and the source area with 1,1-DCE contaminated subsurface soil. Contaminated groundwater surfaces as springs in some off-Base areas. The on-Base groundwater is extracted and treated with air stripping, then discharged to a re-infiltration drain field. The off-Base groundwater is extracted and discharged untreated to the storm sewer because influent concentrations are below the discharge limit. The treatment system at Cooley’s Pond has achieved the cleanup objectives and has been shutdown. The pond is under a monitoring program. The Sump Leach Field site (ST022) consists of the smaller west TCE contaminated groundwater plume. This site is being monitored for natural attenuation. The Building 1946 Evaporation Pond (SD40B) received wash water from a propellant testing laboratory. It has been designated as a site with no further remedial action planned (Radian, 1997) and has been included here for completeness and to document site background information. Table OU 6-1. OU 6 Site Identification.

Site ID Site Name ST022 SUMP LEACH FIELD OT026 ASPHALT PAD SD40B BUILDING 1946 EVAPORATION POND

II Site Chronology

Please see Table OU 6-2 for a history of events in this OU. The table is organized to describe events that impacted the OU as a whole, followed by events impacting specific IRP sites within the OU.

III Background

OU 6 includes buildings and adjacent land in the 1900 and 2000 Areas of Hill AFB, as well as portions of the Craigdale and Farr subdivisions of the City of Riverdale, Utah. Important features within the OU are the Roy Gate Pond, the Davis-Weber Canal, the Class IV landfill, the active Electrical Substation No. 2, and the privately owned off-Base pond (also known as Cooley’s Pond). The on-Base buildings within OU 6 are occupied and operated mainly by the Silo-Based ICBM Program Office. The 2000 Area, along with buildings in the 2100 and 2200 Areas, comprises a security area known as the MAMS-2 (Missile Assembly Maintenance and Storage) area. Off-Base areas are primarily residential subdivisions. Groundwater in the shallow aquifer is currently not used as a source of drinking water, but off-Base water has historically been used for irrigation of lawns and gardens and as water for pets and livestock. In instances where contaminated groundwater was used for these purposes, alternative clean sources have been supplied to residents.


Although buildings in areas now designated as OU 6 have been in use for various purposes since the 1940s, it is believed that the use of operations-related solvent and fuel began in the 1960s when several buildings were modified to support the Bomarc missile testing and maintenance activities. Historically, hazardous wastes generated by the industrial operations were disposed of at the Base Industrial Wastewater Treatment Plant, in chemical disposal pits, in waste disposal ponds, or in landfills. The sources of the OU 6 groundwater contamination have never been documented, as this area did not have historical disposal pits, ponds or waste landfills. The best estimate at this time is that the contamination was introduced to the soils from infrequent, small volume disposals in floor drains, from leaking USTs or merely from wastes being dumped in the sandy areas between buildings. The relatively small mass of contamination in the groundwater and soils is consistent with these scenarios.

IV Remedial Actions

Remedial actions have been implemented at OU 6 to address both on-Base and off-Base contamination. The contaminants of concern at OU 6 include TCE in groundwater and surface water, and 1,1-DCE in on-Base subsurface soil. The remedial action objectives are: • Restore the groundwater aquifer and seeps and springs, and the Cooley’s Pond water to TCE

concentrations of 5 µg/L or less (i.e., the drinking water standard), which results in a risk that is protective of human health.

• Prevent human exposures to 1,1-DCE in subsurface soil that lead to a total excess cancer risk

for 1,1-DCE greater than 1E-6. This corresponds to a concentration of 26 µg/kg or lower. Three treatment systems, including extraction wells and air strippers, have been constructed to stop plume migration and to treat groundwater and surface water contaminated with TCE at the east plume (OT026). Locations of the extraction wells and treatment systems are shown in Figure OU 6-1. For the west plume (ST022), no active treatment was selected, but natural attenuation of the TCE contamination plume is being monitored. No remedial action was required at SD40B because investigation indicated that the site does not pose significant risk to human health and the environment. A continuing order (HAFB 1998) restricts water rights restrictions in both on- and off-Base areas at OU 6. Access restrictions to protect workers from exposure to contaminated soil have been implemented for the on-Base source area of the east plume (OT026).


Since the 1998 FYR (HAFB EMR 1998), additional monitoring wells were installed in 1998 (U6-044, U6-045, U6-046, U6-047) to monitor the west plume. The on-Base pump and treat system was constructed in 1999 and extraction well pumps were upgraded in 2000. Groundwater TCE concentrations continue to decrease due to active remediation and natural attenuation. From 1998 to 2002, the average influent TCE concentrations at the off-Base Craigdale system have declined from 45 to 20 µg/L. From 1999 to 2002, the average influent TCE concentrations at the on-Base system have decline from 80 to 59 µg/L. The Cooley's Pond treatment system was shutdown in 2002 because TCE concentrations in the pond and the influent from the garage spring have dropped below 5 µg/L and the volume of groundwater flows has decreased significantly due to operation of the on-Base system and relining of the Davis Weber Canal. Subsequent sampling has shown that TCE concentrations continue to remain below 5 µg/L. The air stripper at the off-Base Craigdale system has been bypassed because the influent concentration of TCE is below the


discharge limit now that the storm sewer has been lined. Also, the Remote Data System to monitor the treatment systems was completed in 2002.




Results of the technical assessment for each site in OU 6 and for the Operable Unit as a whole are listed in Table OU 6-3 (Technical Assessment of OU 6). Details of the technical assessment for each site in OU 6 are provided in the respective site summary (see Section XIII).




Year Review

OT026 Extraction and air stripping No No No Cannot be

determined 2008

SD40B Not required, NFRAP site NA NA NA NA Not

required

ST022 Natural attenuation Yes Yes No Protective 2008

OU 6 Extraction and air

stripping, and natural attenuation

No No No Cannot be determined 2008

* Question A: Is the remedy functioning as intended by the decision documents? Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective

(RAOs) used at the time of the remedy still valid? Question C: Has any other information come to light that could call into question the protectiveness of the


Question A. Is the remedy functioning as intended by the decision documents? OT026 – Asphalt Pad No. Equipment limitations at the site OT026 On-Base Pump and Treat System (target groundwater levels not reached at extraction wells) and off-Base Craigdale Pump and Treat System (failure of an extraction well) have caused the systems to no longer function as intended. However, it does not appear that this affects protectiveness in the short-term. The extraction well U6-213 was brought back on line on April 28, 2003.

ST022 – Sump Leach Field Yes. Long-term monitoring data indicate TCE concentrations are decreasing due to natural attenuation. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid?


OT026 – Asphalt Pad No. When the remedial investigation was originally conducted, air sampling was performed in homes above the plume that detected levels of TCE that were not considered to be a risk based on the indoor air action level at that time. However, since then, EMR, EPA, and Utah DEQ have jointly established a new action level for TCE concentration in indoor air of 0.43 ppbv. Several of the indoor air results from the original RI were above this new action level, creating the potential for air quality issues that have not been addressed.

ST022 – Sump Leach Field Yes. All exposure assumptions, toxicity data, cleanup levels, and RAOs are still valid.

Question C. Has any other information come to light that could call into question the protectiveness of the remedy? No for both OT026 and ST022.

VIII Issues

Based on the information reviewed, issues that may affect protectiveness of the selected remedies at OU 6 are listed below: 1. The effectiveness of the on-Base and off-Base treatment systems in capturing the plume

cannot be determined at this time because long-term monitoring data were not rigorously evaluated for this FYR. The rates of natural attenuation at the west plume and at the northern arm of the off-Base east plume have not been evaluated, and the remedial timeframe for the groundwater plumes cannot be updated. However, preliminary evaluation of monitoring data indicates that TCE concentration at the west plume appears to be decreasing by natural attenuation. Based on qualitative evaluation of monitoring data between 1998 and 2002 at sentry wells located downgradient of the east plume (U6-025 and U6-026), the east plume appears stable and not expanding.

2. Data for downgradient sentry well U6-030 was not collected between 2000 and 2002 due to

technical problems. Plume stability can be more effectively monitored if samples are collected routinely at this location.

3. Analytical data collected in the northern arm of the east plume (U6-024) indicate that the

TCE concentrations remain above 5 µg/L and do not appear to be decreasing by natural attenuation. Active treatment in this portion of the contaminant plume is to be evaluated, per the ROD, if the TCE concentrations have remained above 5 µg/L after 5 years [after 2002].

4. The groundwater level at extraction wells U6-225 and U6-227 of the on-Base pump and treat

system has never reached the recommended design depth for plume capture (Esplin, T. 2003). Flow rates from the pumps in these wells could be increased to draw down the water level, but the air stripper discharge pump is running at 40 gpm and cannot handle the additional flow. On-Base plume capture is questionable. However, there is no immediate threat to human health due to the lack of an exposure route on-Base.


5. Biofouling at the extraction wells has reduced the volume of groundwater that can be extracted.

6. A new action level for TCE in indoor air, at 0.43 ppbv, has been established which may

introduce air quality issues that have not been previously considered. IX Recommendations and Follow-up Actions for OU 6

The recommendations and follow-up actions for OU 6 are: 1. Continue the long-term monitoring program as described in the Performance Standard

Verification Plan. The monitoring at Cooley’s Pond could be reduced if data indicate that surface water quality is not being affected by the contaminated groundwater (i.e., TCE concentrations remain at or below 5 µg/L and do not show an increasing trend). Also, repair well U6-030 and continue sampling to monitor plume stability.

2. Evaluate long-term monitoring data to determine if the remedy is preventing plume

migration, determine the remedial progress, and update the estimated remedial timeframe. The Performance Standard Verification Report should be conducted as scheduled in 2006.

3. Evaluate the need for active treatment in the northern arm of the off-Base contamination

plume, as required by the ROD. 4. Continue operation and maintenance of the extraction and discharge components of the

Craigdale PTS. Discontinue anti-scaling addition in the off-line air stripper. 5. Continue operation and maintenance of the on-Base pump and treat system. Evaluate

treatment system to determine why target groundwater levels at the extraction wells, an indication of plume capture, have not been achieved. System upgrades may be required or plume capture indicators may need to be updated in the O&M Manual.

6. Develop a long-term maintenance strategy to closely monitor the biofouling problem at the

extraction wells and to ensure that adequate treatment is implemented. 7. Continue all institutional controls. In addition, perform routine checks of locks, fences, and

signs at wells and treatment facilities to prevent accidental exposure to contaminated water. 8. Re-evaluate indoor air data, and if necessary, obtain additional air samples, to determine if

the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas. If additional indoor air samples are needed, they should be collected during winter months when vapor intrusion will reach its maximum.


The protectiveness at OU 6 cannot be determined until further information can be obtained. Current data indicated that TCE concentrations in the west plume appear to be decreasing by natural attenuation. The Cooley’s Pond treatment system has achieved its remedial active objective and has been shutdown. The off-Base and on-Base systems removed TCE from extracted groundwater with high efficiency and have continuously met the discharge limits.


Based on preliminary evaluation of monitoring data collected between 1998 and 2002, TCE concentration in the east plume is decreasing and the plume appears stable. In addition, the required institutional controls to prevent human exposure to contaminated groundwater and subsurface soil have been implemented. However, since impact of the OU 6 groundwater plume to indoor air quality at off-Base residences is unknown at this time, protectiveness cannot be determined. Indoor air quality should be evaluated to determine if it has been adversely affected by the OU 6 groundwater plume. Remedial action should be implemented as necessary. Also, long-term monitoring data need to be evaluated in detail to ensure that the remedy is preventing plume migration to off-Base areas; therefore, a completed PSVR, scheduled in 2006, will be useful for determining the protectiveness of the remedial actions at OU 6 during the next Five-Year Review (2008).

XI Next Review

The next FYR for OU 6 is required by 2008. No future review is required for the Building 1946 Evaporation Pond (SD40B) because no further remedial action is planned at this site.


(ERM 1993) Preliminary Assessment/Site Investigation, Building 1946 Evaporation Pond, ERM-Rocky Mountain, Inc., January 1993. (Esplin, T. 2003) Esplin, T., Site Engineer for OU 6, URS Corp., Personal Communication, 27 January 2003. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (Radian 1997) Record of Decision Operable Unit 6 Sites ST022, OT026, SD40B, Radian, August 1997.



OU 6 OPERABLE UNIT 61988 Investigation of the off-Base

shallow groundwater and surface water east-northeast of Hill AFB boundary

1988 - 1993, performed by Hill AFB EMR. 23 locations sampled periodically for VOCs. TCE was the main contaminant detected.

Remedial Investigation Report Operable Unit 6 Sites ST22, OT26 Volume 1 Text

1989 Preliminary Assessment Preliminary Assessment was performed in 1989 and 1990. Hill AFB Environmental Restoration Management Action Plan - 2001

1989 Soil gas investigation along Perimeter Road

Performed by Radian and included an approximately one-mile stretch along Hill AFB's northern boundary through what is now known as OU 6. Results indicated elevated VOC concentrations east and northeast of the Waste Asphalt Pile, but show no “significant concentration” (two orders of magnitude above background concentration).


1990 Site evaluation study to determine whether on-Base areas are the source of contaminants (primarily TCE) detected in the off-Base area

1990 - 1992, performed by Radian. Detected on-Base TCE concentrations were approximately an order of magnitude lower than off-Base concentrations. No definitive TCE source area identified at the site. Investigators theorized source may consist of several areas of small-scale surface spills.


04 1991 Hill AFB entered into a Federal Facilities Agreement with UDEQ and EPA

Agreement entered on 4/1/1991. Record of Decision Operable Unit 6 Sites ST022, OT026, SD40B





1992 Site Inspection Hill AFB Environmental Restoration Management Action Plan - 2001

10 1993 Remedial Investigation Two groundwater contaminant plumes identified at the site: one entirely on Base and one extending to the Craigdale subdivision in the off-Base area. The approximate source areas were defined. Risk assessment determined possible future exposures associated with domestic use of groundwater containing TCE and 1,1-DCE might pose an unacceptable cancer risk.

Action Memorandum Operable Unit 6

07 1995 Remedial Investigation -Conducted 1993-1995-Determined the nature and extent of contamination. Identified two groundwater plumes, west plume entirely on-Base, east plume extends off Base. TCE and methylene chloride are the only organic contaminants present in concentrations greater than their MCLs for drinking water. The maximum concentration of methylene chloride was 7 ug/L, and results above the MCL were not reproducible.

Remedial Investigation Report Operable Unit 6 Sites ST22, OT26 Volume 2 Appendices

09 1996 Long Term Operation and Long Term Monitoring

Off-Base LTO/LTM began in 1996On-Base LTM/LTM began in 1999


09 1996 Feasibility Study Hill AFB Environmental Restoration Management Action Plan - 2001





11 1996 Proposed Plan Hill AFB Environmental Restoration Management Action Plan - 2001

12 1996 Action Memorandum - Removal action selected

Phase I&II: pump & treat systems in the Craigdale subdivision; Phase III: relining Davis-Weber Canal requires more study; Phase IV: on-Base plume should be contained, type of treatment will be selected after treatability study to evaluate in-situ air sparging/SVE and in-situ UVB technologies; Phase V: delay pump and treat system for northern portion of the off-Base plume until effectiveness of Phase II to IV can be evaluated, monitor TCE concentration in the interim.

Action Memorandum Operable Unit 6

09 1998 PCB removed near Electrical substation No. 2 (Building 2501)

July to September 1998. Removal action addressed under the Toxic Substances Control Act. Contaminated soil was excavated and site was backfilled with clean soil. Electrical substation still active.

Interim PCB Contaminated Soil Removal Report for Electrical Substation No. 2

11 2001 Performance Standard Verification Plan completed

Documents the long-term monitoring plan for OU 6. Performance Standard Verification Plan Operable Unit 6

09 2006 PSVR scheduled due date Bob Elliott, Personal Communication 1/2/2003, Federal Facilities Due Dates as of Jan 2003





ST022 SUMP LEACH FIELD1950 late 1950s - mid 1985:

Contamination introduced at drainfield

Building 1915 was used to test Bomarc missile ramjet packages, which are the missiles' fuel delivery system. The drain field received flow from floor drains in Building 1915, and the former locations of a fuel tank and a waste fuel tank which were located between 65 and 95 feet north of the building.


1988 Site Evaluation of Building 1915 Area and Roy Gate Pond

TPH found in soils at the former site of an underground fuel storage tank. No contamination observed in solids around location of former subsurface drain field. Following sediment and surface water sampling, no further action recommended at Roy Gate Pond. Report: Chen-Northern, Inc. 1989. Building 1915 Site Evaluation Report, Hill Air Force Base, Ogden, Utah.


10 1997 Record of Decision ROD signed 10/1/1997. Contamination allowed to naturally attenuate.


OT026 ASPHALT PAD1988 U.S. Air Force conducted water

sampling in Craigdale subdivision area

Found chlorinated solvents, primarily TCE, in shallow groundwater and surface water.






1993 Interim Remedial Action 1993-1996. Provided an alternate source of clean irrigation water to two homes affected by shallow groundwater contamination. Collected and treated contaminated water from springs and field drains, and discharged treated water to a storm drain. Extracted and treated contaminated groundwater in the off-Base area as part of a removal action described in the Action Memorandum


1993 Interim Remedial Action 1993-Present. Interim actions include alternate irrigation water sources, seep/spring water and groundwater recovery and treatment, alternative groundwater treatment technology evaluation. These actions have been incorporated as part of the final actions.


10 1994 Engineering Evaluation/Cost Analysis

Proposed to implement remedial action at OU 6 in 5 phases. Action Memorandum Operable Unit 6

10 1994 Engineering Evaluation/Cost Analysis

The OU 6 EE/CA (Oct 1994) initiated Phase 2 of the removal action to construct the pump and treat system for the off-base portion of the plume


09 1996 Startup of Craigdale Off-Base PTS Construction of Craigdale PTS was completed under the Action Memorandum (Dec 1996). This was Phase 1 and 2 of the remedial action.






09 1996 Startup of Craigdale Off-Base PTS Technology used is air stripping. Construction period Aug/1995 – July/1996


10 1997 Record of Decision ROD signed 10/1/1997. Site requires active treatment. Hill AFB Environmental Restoration Management Action Plan - 2001

12 1997 Modification to Cooley's Pond treatment system

The Cooley's Pond Treatment System was originally completed as a removal action under the basewide seeps and springs EE/CA. (Final Basewide Engineering Evaluation/Cost Analysis for Contaminated Seeps and Springs, Hill AFB (Montgomery Watson, 1994).This treatment system has been modified over time to improve efficiency. Initially, a carbon adsorption system, housed in a separate shed, was used to treat water from the Garage Spring U6-303 and treated water was discharged to the pond. An air stripper, housed in a separate locked building, was used to treat the pond water and the treated water was discharged to the pond drain pipe. Resident complained about the noise. In 1998, a quieter air stripper was installed and the building was heavily insulated. To further reduce noise, system operation was changed from 24 hours to 16 hours per day.


12 1997 Startup of Cooley’s Pond PTS using a new air stripper

Technology used is groundwater extraction and air stripping. Performance Standard Verification Plan Operable Unit 6





03 1998 Remedial Design Design of the On-Base pump and treat system. Hill AFB Environmental Restoration Management Action Plan - 2001

06 1999 Remedial Action Construction of the On-Base pump and treat system with 6 extraction wells and one air stripper.

FYR Site List

07 1999 Davis-Weber Canal failed Canal failed downstream (west, northwest) from where the OU 6 east plume crosses to the Cooley and Craigdale systems. The systems were not impacted by the failure.

Mark Loucks, Personal Communication 3/18/03, Davis-Weber Canal Information

07 1999 Startup of on-Base PTS Technology used is groundwater extraction and air stripping. (Phase IV of remedy)


06 2000 The Davis-Weber Canal was relined This corresponds to Phase III of the removal action. The canal company constructed an enclosed concrete culvert from a point east of the OU 6 plume to a point west of the plume.

Oscar Torres, Personal communication 1/30/2003, Davis-Weber Canal Information

11 2000 Cooley's residence burned House burned on 11/18/2000 and was not rebuilt. Garage remains and still in use as of 2003. Water collected in the foundation drain was piped to Cooley’s seep, which was piped to the Craigdale system. The foundation drain was destroyed when the house burned.

Interview with Oscar Torres





08 2002 Air stripper at Cooly’s Pond was taken off-line, but monthly groundwater sampling continues

Garage sump and air stripper influent TCE concentrations remained below the MCL of 5.0 ug/L in August, November, and December 2002.Basis for shutdown: In 2002, Air stripper influent TCE levels were not detectable in May, June, and August, while in February, March, and July TCE levels were 0.7 ug/L or lower. April had the highest concentration of 1.50 ug/L of TCE.

Operable Unit 6 Cooley's Pond Treatment System Monthly Operation Summary, January - August 2002

11 2002 Craigdale air stripper bypassed System now extracts groundwater and discharges to the storm drain. After the storm drain was completely lined in fall 2001, the discharge limit was governed by the Surface Water Quality Protection rule (R317-2-14, Table 2.14.6) instead of the Groundwater Quality Protection rule (R317-6-4). The TCE discharge limit for the Craigdale treatment system was changed from 1/4 MCL (1.25 ug/L) to 81 ug/L. Acceptance by regulatory agencies was given on 9/26/2002.

Interview with Oscar Torres

SD40B BUILDING 1946 EVAPORATION POND1962 1962-1992 Evaporation pond held

waste water from the propellant testing laboratory


1993 Preliminary assessment/site investigation of Building 1946 evaporation pond

Performed by ERM-Rocky Mountain, Inc. Concluded that past discharges to the evaporation pond have deposited some explosives in the surface soils and sediments within the dimensions of the pond and low levels of TCA in the shallow groundwater.






10 1997 Record of Decision ROD signed 10/1/1997. NFRAP for SD40B. Hill AFB Environmental Restoration Management Action Plan - 2001




OU 6 ST022 SUMP LEACH FIELD


III. Background The drain field received flow from floor drains in Building 1915, and the former locations of a fuel tank and a waste fuel tank, which were located between 65 and 95 feet north of the building. From the late 1950s to 1985, Building 1915 was used to test Bomarc missile ramjet packages, which are the missiles' fuel delivery system.

The west groundwater contamination plume (Site ST022-Sump Leach Field) is located entirely on-Base near the 1900 Area and contains low concentration of TCE and occurs generally 100 ft or more below the ground surface. The direction of groundwater flow is northeast. Groundwater in the shallow aquifer is currently not used as a source of drinking water.


The selected remedy for the OU 6 west plume is natural attenuation.


Long-term monitoring has continued in the west plume since the last Five-Year Review (HAFB EMR 1998). Additional wells installed since 1998 to monitor the remedial progress of the OU 6 west plume include U6-044, U6-045, U6-046, U6-047. Installation was completed in September 1998.


Question A (Answer)

Yes


Long-term monitoring data for a sampling location within the OU 6 west plume (U6-018) indicate that the TCE concentrations are decreasing. From 1996 to 2002, TCE concentrations at U6-018 have decreased from 30 ug/L to 10 ug/L. For the same period, TCE concentrations for locations surrounding the West Plume (U6-045, U6-046, U6-009, U6-



I. Introduction Site ST022 is the west groundwater contamination plume at OU 6. The plume is being monitored for natural attenuation.




* Restore the groundwater aquifer … to TCE concentrations of 5 ug/L or less (i.e., the drinking water standard), which results in a risk that is protective of human health.




OU 6 ST022 SUMP LEACH FIELD


2008

047, U6-044) have remained below 5ug/L, mostly below the detection limit of 0.4 ug/L. This information provides an indication that the west plume has not expanded downgradient. Detailed data analysis will be included in the upcoming PSVR and results will be available before the next Five-Year Review (2008).

Question B (Answer)

Yes


The current Utah and federal drinking water standard for TCE is 5 ug/L, the same as when the risk assessment was performed at OU 6. Land use at this site has not changed. The remedial action objective listed in the OU 6 ROD for this site is still valid.

Question C (Answer)

No


No information has surfaced that calls into question the protectiveness of the selected remedy.

VIII. Issues Because the long-term monitoring data have not been analyzed in detail, the rate of natural attenuation cannot be determined and the remedial timeframe cannot be updated at this time.

IX. Recommendations *Continue long-term monitoring program at OU 6.

*Conduct the Performance Standard Verification Report as scheduled in 2006. This PSVR should provide detailed analyses of long-term monitoring data to determine the remedial progress and update the estimated remedial timeframe.



The selected remedy associated with site ST022 is protective of human health and the environment. The TCE concentration in the west plume appears to be decreasing by natural attenuation.




OU 6 OT026 ASPHALT PAD


III. Background Site OT026 is located near the former waste asphalt pile, currently the Class IV landfill, near the 2000 Area. Surface features at the site include a Class IV landfill, the Davis-Weber Canal, the active Electrical Substation No. 2 (Building 2501), and the off-Base man-made pond (also known as Cooley's Pond). Groundwater in the shallow aquifer is currently not used as a source of drinking water, but off-Base it has been historically used for irrigation of lawns and gardens and as water for pets and livestock. In instances where contaminated groundwater was used for these purposes, alternative clean sources have been supplied to residents.

The TCE contamination in the groundwater begins at the 2000 Area of Hill AFB and extends off-Base into the Craigdale and Farr subdivisions of the City of Riverdale, Utah (see Figure OU 6-1). Contaminated groundwater also surfaces as springs in some off-Base areas. On-Base, the direction of groundwater flow is to the north; off-Base, the direction of groundwater flow is to the northeast. Subsurface soil contaminated with 1,1-DCE is located entirely on-Base in the high security MAMS-2 (Missile Assembly Maintenance and Storage) area. The subsurface soil contamination was found near the location of two former USTs, near test well U6-006. Underground storage tanks (USTs) and associated piping that contained solvents may have leaked and contaminated the soil and groundwater. The specific cause of the release of solvents to the environment at OU 6 is not known.

Interim remedial activities included providing off-Base residences with an alternate source of clean irrigation water, extracting and treating contaminated groundwater (Craigdale pump and treat system) to stop plume migration, and collecting and treating contaminated surface water from springs (Cooley's Pond treatment system). The OU 6 Record of Decision was published in 1997, which lead to the construction of the On-Base pump and treat system to stop contamination migration off-Base.

Surface water seen near Cooley’s Pond system is thought to originate both from the natural groundwater flows and the leaking of the Davis-Weber Canal. Flow at the Cooley’s Pond system has significantly reduced due to the startup of the On-Base system in 1999 and the relining of the Davis-Weber Canal in 2000.


I. Introduction Site OT026 is the east groundwater contamination plume at OU 6, which extends off-Base into the city of Riverdale. Contamination consists of TCE in groundwater and surface water and 1,1-DCE in subsurface soil at the source area. Groundwater and surface water are extracted or collected and treated by air stripping in three treatment facilities.


SOIL 1,1-DICHLOROETHENE 26 ug/kg







Off-Base surface water remediation - Collection and treatment in an air stripper, 1994 - 2002The Cooley’s Pond Treatment System reduces TCE concentrations in Cooley's Pond by cycling pond water through an air stripper. Water from the Garage Spring U6-303 is pumped to the pond for treatment. The air stripper has been shut down since August 2002 because the remedial action objective was achieved (i.e., the TCE concentrations in the pond water and Spring U6-303 water have remained below 5 ug/L since July 2001).

Off-Base groundwater remediation - Extraction and treatment in an air stripper, 1996 - 2002; Extraction and discharge to storm sewer, 2002 -presentThe Craigdale Pump and Treat System is located downgradient of Cooley's Pond System and consists of six extraction wells located along 1150 West and 1200 West and is intended to stop plume migration. In addition, groundwater from a seep, known as the Cooley Seep, is collected and routed to the treatment system using the 1200 West groundwater conveyance lines. Extracted groundwater can be treated by a low-profile air stripper and then discharged to the Riverdale City storm drain and ultimately to the Weber River. Air stripping was discontinued (air stripper bypassed) in November 2002, when the TCE discharge limit changed from 1.25 ug/L to 81 ug/L after lining of the storm sewer was completed. Natural attenuation was chosen as the remedy for the northern arm of the off-Base contamination plume.

On-Base groundwater remediation – Extraction and treatment with an air stripper, 1999 - presentThe On-Base Pump and Treat System consists of six extraction wells, located along the northern boundary of Hill AFB and along the northern edge of the MAMS-2 area, and was designed to stop migration of the contamination to off-Base areas. Extracted groundwater is treated by a low-profile air stripper and discharged to a re-infiltration drain field. As a back-up discharge provision, the treatment system includes discharge piping connected to the North Davis County Sewer District Publicly Owned Treatment Works (NDCSW POTW).

Institutional ControlsA Continuing Order (HAFB 1998) has been issued to restrict disturbance of contaminated soil and groundwater and to restrict installation of water wells on-Base at OU 6. The Utah Division of Water Rights has also restricted water well drilling and the use of shallow groundwater at off-Base areas near OU 6. The treatment building at Craigdale is locked, warning signs are posted on the building, and extraction wells are locked. The treatment building at Cooley's Pond is locked and is located on the Cooley / Winn property. The On-Base treatment building is locked and the fence around the building and well field is also locked.



* Restore the groundwater aquifer and seeps and springs, and the Cooley’s Pond water to TCE concentrations of 5 ug/L or less (i.e., the drinking water standard), which results in a risk that is protective of human health.* Prevent human exposures to 1,1-DCE in subsurface soil that lead to a total excess cancer risk for 1,1-DCE greater than 10^-6. This corresponds to a concentration of 26 ug/kg or lower.






The construction of the On-Base PTS was completed in 1999 and the treatment system has been operating since. In 2000, all six extraction well pumps were upgraded from 1/2 hp to 1 hp to increase the volume of groundwater that can be extracted.

The remedial action objective for Cooley's Pond treatment system has been achieved. the TCE concentration in pond water and in the influent from the garage spring has dropped below the drinking water standard (5 ug/L) and has remained below 5 ug/L since July 2001. The Cooley's Pond treatment system has been shut down since August 9, 2002, and long-term monitoring consisting of monthly sampling at the pond continues. Subsequent sampling at the pond after system shutdown has shown that concentrations continue to remain below the 5 ug/L level.

Installation of the Remote Data System at all three treatment facilities was completed in 2002. The RDS enables the remote monitoring of the treatment systems and reduced site visits and O&M cost.

Groundwater TCE concentrations continues to decrease due to active remediation and natural attenuation. From 1998 to 2002, the average influent TCE concentrations at the off-Base Craigdale system have declined from 45 to 20 ug/L. From 1999 to 2002, the average influent TCE concentrations at the on-Base system have declined from 80 to 59 ug/L.


Question A (Answer)

No


Cooley’s Pond Treatment System - YesThe Cooley’s Pond influent (U6-303) and pond water (U6-401) TCE concentrations have dropped below the MCL of 5 ug/L and have remained below 5 ug/L since July 2001. According to the analytical data, the remedial action object has been achieved for this treatment system. From 1990 to 2002, TCE concentrations in the Pond have decreased from 15 ug/L to 1.7 ug/L.

Off-Base Craigdale Pump and Treat System - NoIn the last five years, the system has operated continuously with minor down time due to scheduled maintenance, and power failures. The system has continuously met the previous storm sewer discharge limit of 1/4 of the MCL (1.25 ug/L). From 1996 to 2002, TCE concentrations in the influent decreased from 66 ug/L to 20 ug/L. Extraction well U6-213, located at the leading edge of the contamination plume, had been off-line since February 2002 due to electrical problems. Operation of this well was restored on April 28, 2003. Failure of this well may have allowed the plume to migrate further off-Base. However, the plume does not appear to be expanding based on qualitative evaluation of data from sentry wells (U6-025 and U6-026) located downgradient of the east plume.






On-Base Pump and Treat System - NoSince startup, the On-Base PTS has been operating continuously with occasional down time due to scheduled maintenance, power failures, and equipment failure. Laboratory analysis of system effluent shows TCE concentration remained below the detectable limit of 0.4 ug/L from July 1999 (startup) to July 2002. The system removal efficiency has remained above 99% and the plant has continuously met the discharge limit of 1.25 ug/L. From 1999 to 2002, TCE concentrations in the influent have decreased from 80 ug/L to 59 ug/L. The recommended groundwater level to capture the plume at two of extraction wells (U6-225 or U6-227) have not been achieved. However, there is no immediate threat to human health due to the lack of an exposure route on-Base. Since the plume appears stable, the contaminants that migrate off-Base will be removed by the Off-Base Craigdale system.

Institutional Controls - YesA Continuing Order to restrict disturbance of contaminated water and soil on-Base at OU 6 has been issued and the Utah Division of Water Rights continuously enforces the restrictions on well drilling and use of shallow groundwater on-Base and off-Base at OU 6. Exposure to contaminated groundwater at treatment facilities is prevented by warning signs, fences, and locks on wells and treatment buildings. The Base continues to maintain high security at the MAMS-2 area, which prevents human exposure to contaminated subsurface soil at the source area.

Question B (Answer)

No


The current Utah and federal drinking water standard for TCE is 5 ug/L, the same as when the risk assessment was performed at OU 6. According to EPA Region III Risk-Based Concentration Tables (October 2002), 1,1-DCE has been reclassified from cancerous to non-cancerous. Therefore, the soil cleanup level for 1,1-DCE is overprotective.

When the remedial investigation was originally conducted, air sampling was performed in a number of homes above the plume. TCE was detected in several residences, but at levels that were not considered to be a risk at that time. Due to recent emphasis on vapor intrusion, EMR has worked with the EPA and Utah State to establish an action level for TCE in indoor air at 0.43 ppbv. Because several of the air results from the original RI were above the new action level, there potentially are air quality issues that have not been addressed.

Question C (Answer)

No


The Craigdale PTS discharges to the Riverdale City storm sewer, and the storm sewer has recently been lined. The discharge limit that was governed by the groundwater protection rule, which allowed discharge of TCE up to 1/4 the MCL (1.25 ug/L), is now governed by





the surface water protection rule, which allows discharge of TCE up to 81 ug/L. As of November 2002, active treatment in the air stripper at the Craigdale PTS has ceased; groundwater is extracted and then discharged to the storm sewer. The change will not affect the protectiveness of the remedy. Since the air stripper has been shutdown, TCE concentrations of all compliance sampling in the storm sewer have been below detection limits.

VIII. Issues Plume Containment and Natural Attenuation Rates* The long-term monitoring data have not been analyzed in detail, and the effectiveness of the treatment systems for containing the contaminant plume and the rate of natural attenuation have not been evaluated. The remedial timeframe cannot be updated at this time. However, preliminary evaluation of monitoring data collected between 1998 and 2002 from sentry wells located just downgradient of the plume (U6-025 and U6-026) indicates the plume appears stable and has not migrated downgradient.

* Data for downgradient sentry well U6-030 was not collected between 2000 and 2002 due to technical problems. Plume stability can be more effectively monitored if samples are collected routinely at this location.

* The northern arm of the off-Base contamination plume has been allowed to naturally attenuate. However, analytical data collected in the northern arm (U6-024) indicate that the TCE concentrations range from 7 ug/L to 32 ug/L and do not appear to be decreasing. Per the ROD, active treatment in this portion of the contaminant plume needs to the evaluated, as required by the ROD, because the TCE concentrations have remained above 5 ug/L after 5 years [after 2002].

Operations and Maintenance* Scaling in the air stripper at the Craigdale PTS was minimized with continual addition of an anti-scale chemical polymer. However, since the air stripper was bypassed in November 2002, anti-scale treatment has continued and thus may be contributing to unnecessary O&M costs.

* Extraction well U6-213 of the Craigdale PTS, located at the leading edge of the contamination plume, had been off-line since February 2002 due to electrical problems. This could have allowed contaminated groundwater to migrate downgradient. However, the well was brought back online on April 28, 2003.

* The on-Base PTS O&M Manual (URS 2002) provides recommended water levels at each of the extraction wells to capture the plume. The groundwater level has never been lowered to the recommended depth in extraction wells U6-225 or U6-227.

* Biofouling at the On-Base and Off-Base extraction wells is a significant problem that impedes the extraction of groundwater for treatment. The extraction wells have been rehabilitated in summer of 2002; wells were acid washed, screens were cleared, wells redeveloped, and pumps cleaned. This initial treatment at the wells has increased the volume of extractable water. Quarterly chlorine treatment and annual rehabilitation of the wells is scheduled.





Institutional Controls* Monitoring wells in the residential areas were not properly locked. Breach of security can lead to possible exposure to contaminated groundwater.

Health Risk*Some of the indoor air sampling results, collected during the RI, exceed the new action level for TCE in indoor air (0.43 ppbv).

IX. Recommendations Plume Containment and Natural Attenuation Rates* Evaluate long-monitoring data to determine if the remedy is preventing plume migration, to determine the remedial progress, and to update the estimated remedial timeframe. The Performance Standard Verification Report should be conducted as schedule in 2006.* Evaluate the need for active treatment in the northern arm of the off-Base contamination plume.* Fix well U6-030 and continue sampling to monitor plume stability. * Continue the long-term monitoring program. The monitoring frequency at Cooley’s Pond should be reduced if concentrations continue below 5 ug/L.

Operations and Maintenance* Continue operation and maintenance of the extraction and discharge components of the Craigdale PTS.* Discontinue anti-scaling treatment in the off-line air stripper at the Craigdale PTS.* Evaluate the On-Base PTS to determine why target groundwater levels at the extraction wells, which are an indication of plume capture, have not been achieved. System upgrades may be required or plume capture indicators may need to be updated in the O&M Manual.* Develop a long-term maintenance strategy to closely monitor the fouling problem at the extraction wells and ensure that adequate treatment strategies are implemented.

Institutional Controls* Continue all institutional controls. In addition, perform routine checks of locks, fences, and signs at wells and treatment facilities to prevent accidental exposure to contaminated water.

Health Risk* Reevaluate RI data on indoor air and determine if the new action level for TCE in indoor air would warrant additional mitigation measures in off-Base residential areas. If additional air samples are needed, they should be collected during winter months when vapor intrusion will reach its maximum.



The protectiveness of remedies at OT026 cannot be determined until additional information can be gathered. The Cooley’s Pond treatment system has achieved its remedial active






2008

objective and has been shutdown. The off-Base and on-Base systems removed TCE from extracted groundwater with high efficiency and have continuously met the discharge limits. Based on preliminary evaluation of monitoring data collected between 1998 and 2002, TCE concentration in the east plume is decreasing and the plume appears stable. Also, the required institutional controls to prevent human exposure to contaminated groundwater and subsurface soil have been implemented.

To ensure protectiveness, long-term monitoring data need to be evaluated in detail to ensure that the remedy is preventing plume migration to off-Base areas and include: a completed PSVR, scheduled in 2006, which will be useful for determining the protectiveness of the remedial actions during the next Five-Year Review (2008); an evaluation of monitoring data for the rate of natural attenuation in the northern arm of the OU 6 off-Base east plume to determine if the remedial timeframe is reasonable; evaluation of the treatment system at the on-Base PTS to determine if system upgrades are required to achieve target groundwater levels or if plume capture indicators need to be updated; and an evaluation of the RI data on indoor air and collection of additional indoor air samples as necessary to determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas.




OU 6 SD40B BUILDING 1946 EVAPORATION POND


III. Background The Building 1946 evaporative pond was investigated as part of OU 6. From 1962 until 1992, the evaporation pond located near Building 1946 was used to hold wastewater from the propellant testing laboratory housed Building 1946. The pond is dry except during periods of significant rainfall. The pond is 25 ft in diameter with a maximum depth of 4 ft. The Building 1946 Evaporation Pond PA/SI (ERM-Rocky Mountain 1993) determined that past discharges to the evaporation pond deposited some explosives in the surface soils and sediments within the dimensions of the pond and low levels of TCA in the shallow groundwater. The pond was found to pose insignificant risk to human health and the environment. Per the OU 6 ROD (Radian 1997), no further action is needed for this site.


Not applicable.


Site was not reviewed for 1998 Five-Year Review Report. No action has occurred since 1998.


Question A (Answer)

Not Applicable


Not applicable.

Question B (Answer)

Not Applicable



I. Introduction Site SD40B is the Building 1946 evaporative pond located in the northern portion of Base near the Base museum. No remedial action was required at this site. This site is included in the 2003 Five-Year Review for completeness to document the site background.




NA





OU 6 SD40B BUILDING 1946 EVAPORATION POND




Not applicable.

Question C (Answer)

Not Applicable


Not applicable.

VIII. Issues None.




SD40B was recommended for NFRAP status and accepted in 1997 because investigations indicate that this site poses no risk to human health and the environment.




Operable Unit 7

I Introduction

OU 7 is a soils-only operable unit with five IRP sites (see Figure OU 7-1 for locations). Site identification numbers and site names are indicated in Table OU 7-1. The only connection among the sites other than geographical location on the Base is the connection between the Building 225 Chromium Spill site (site SS027) and the Sill property in Layton (site SS028). Fill excavated from a utility trench in Building 225 was placed at two locations on the Sill property. This fill material was later found to be contaminated with chromium. A removal action then ensued to remove the contaminated fill for proper disposal in a Resource Conservation and Recovery Act (RCRA) approved landfill. The chromium spill site (site SS027) is a result of activities in the former Metal Plating Shop Area. The contamination associated with this site underlies a portion of Building 225. Two contaminants of concern exist at this site, hexavalent chromium and cadmium. Site SS027 is the only site containing contamination above both background levels and health risk standards. The other four sites have been closed through either separate decision documents (sites SS028 and OT029) or through the Record of Decision (ROD) (sites ST031 and SS032) and will not be discussed further in this OU Summary. The existing floor slab overlying the former Metal Plating Shop Area in Building 225 protects human health of the area personnel by preventing exposure to contaminated soil. The ROD specifies enacting institutional controls, conducting an inspection and maintenance program, and conducting soil moisture measurements and groundwater quality monitoring for this area.


Site ID Site Name SS027 BUILDING 225 CHROMIUM SPILL ST031 BUILDING 220 UNDERGROUND TANKS SS032 BUILDING 225 PCB SS028 SILL PROPERTY, LAYTON OT029 BUILDING 204 BERYLLIUM UNDERGROUND WASTE TANK

II Site Chronology

Please see Table OU 7-2 for a history of events in this OU. The table is organized first to describe events that impacted the OU as a whole. Events impacting only specific IRP sites within the OU are listed separately.

III Background

The former Metal Plating Shop was located along the east side of Building 225 and was in operation from the 1940s through 1972. Contents of the plating solution tanks containing acids, bases, metal salts, and other chemicals frequently were discharged into a floor drain system that was connected to the industrial waste pipeline. Over time, the plating solutions corroded the drains and piping and the discharged liquids leaked into the subsurface soil. The closed sites included in OU 7 have various and generally unrelated histories. Refer to individual site summaries, shown in Section XIII, for background information.


IV Remedial Actions

The selected remedy at site SS027 consists of applying institutional controls, conducting an inspection and maintenance program for the floor slab in the area of the former Metal Plating Shop, and conducting performance monitoring. Institutional controls consist of a continuing order from the Base commander to restrict water use (HAFB 1998), restrictions on worker access, deed restrictions, and warning signs (HAFB EMR 1995). The inspection and maintenance program consists of an annual inspection of the floor slabs and delineates three areas of attainment intended to ensure that cracks or fractures, that could provide a means of transporting fluids to the sub-floor soil or expose workers to contaminated soil, are repaired. The areas of attainment were delineated based on contaminant concentrations detected during the remedial investigation (RI). The performance monitoring includes semi-annual monitoring of soil moisture content to detect leaks beneath the slab at six monitoring locations and groundwater quality at three wells (one upgradient, one within the source area, and one downgradient) (MW 1998).

V Progress Since Last Five-Year Review No actions were identified for this OU in the 1998 FYR (HAFB EMR 1998a). Since 1998,

institutional controls, the inspection and maintenance program, and the performance monitoring have continued per the schedule set forth in the Final Remedial Design/Remedial Action Work Plan for Operable Unit 7 (MW 1996).


Results of the technical assessment for each site in OU 7 and for the operable unit as a whole are listed in Table OU 7-3. Details of the technical assessment for each site in OU 7 are provided in the respective site summary (see Section XIII).




Next Five-Year

Review SS027 Floor Slab No No Yes Protective 2008 ST031 NA NA NA NA NA NA SS032 NA NA NA NA NA NA

SS028 NA NA NA NA NA NA OT029 NA NA NA NA NA NA

OU 7 Floor Slab No No Yes Protective 2008 * Question A: Is the remedy functioning as intended by the decision documents? Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs)




Question A. Is the remedy functioning as intended by the decision documents? No. The intended function for the remedy in place at site SS027 is summarized by the RAOs for this site (located in the site summary in Section XIII). Two of the three RAOs are not being achieved. First, reduction of contaminant transport within the source areas by minimizing surface water infiltration may not be realized. Annual site inspections identified defects in the floor slab, which had been noted during previous annual inspections that have not been repaired. These defects could provide a conduit for infiltration of water through the floor slab. Second, reduction in contaminant transport to rates that will not impact groundwater quality above MCLs is not being achieved. The hexavalent chromium concentrations within the source area are above the groundwater MCL for total chromium (no MCL exists for hexavalent chromium in groundwater) and have been since 1996 (pre-ROD hexavalent chromium concentrations were below MCLs). Additionally, the concentrations downgradient of the source areas consistently demonstrate chromium concentrations higher than concentrations upgradient, suggesting that transport of contaminants from the site is occurring. One of the areas of attainment does not contain any soil moisture probes. Soil moisture compliance in this area cannot be evaluated. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? No. The reference dose for hexavalent chromium has changed from 0.005 to 0.00003 in soil (100 times more stringent) per EPA Region III RBC table (EPA Region III 2002). The RAOs do not need to be modified in light of this change because the RAOs state "MCLs" and do not specify the level. Question C. Has any other information come to light that could call into question the protectiveness of the remedy? Yes. The warning signs within the areas of attainment do not warn area personnel of the contaminated soils underlying the floor slab or of a threat to human health if exposed to the soil. The absence of such a warning may cause unsuspected and unreported exposures. Groundwater concentrations exceeding MCLs for chromium were reported in the 1999 Annual Report (MW 1999) and no action has been taken to determine the root cause of this issue. Also, defects in the floor slab, likely affecting infiltration, were reported in the 2001 Annual Report (URS 2002). The O&M contractor indicated, during the site inspection, that the floor is being washed on a regular basis. This suggests that infiltration has increased due to the unrepaired defects in the floor slab.

VIII Issues

All issues recommended in this section pertain to the Building 225 Chromium Spill site (site SS027) only. Additional details regarding these recommendations are available from the SS027 Site Summary found in Section XIII. Institutional Controls 1. Warning signs within Building 225 (site SS027) are not in compliance with the intent of the

ROD. Per the ROD, the selected remedy at OU 7 includes: "Posting warning signs regarding the presence of contaminated soils that could represent a threat to human health." The signs currently posted say, "Caution: Do Not Disturb Floor, Contact EMR, Phone 7-8790". The


current signs do not inform area personnel of the contaminated soils in the areas of attainment underlying the floor slab or of a threat to human health.

Inspection and Maintenance Program 2. Defects in the floor slab, that affect infiltration rates, recommended for repair in the 2001

annual report (URS 2002) have not been repaired at the time of this review. 3. The tape delineating the areas of attainment is in disrepair (torn, peeling, etc.). Performance Monitoring 4. Hexavalent chromium concentrations above total chromium MCLs have been measured in

the groundwater underlying the floor slab since 1996. 5. Downgradient concentrations of hexavalent chromium are above the upgradient

concentrations suggesting a release of contaminants to the aquifer at Building 225. 6. Soil moisture monitoring objectives and process are not clear. Action levels for a soil

moisture increase are not clearly identified nor is an action plan in place if an action level is reached. Data comparison is completed at one interval (7-8 feet bgs) only and no rationale for reviewing only that depth is given. Historically, logging has not been performed during the same months of the year.

7. No soil moisture data are available in ERPIMS to facilitate a thorough performance review for the floor slab remedial action.

General 8. PSVP recommendations have not been incorporated fully into the LTM and O&M contracts

to ensure monitoring and reporting is comprehensive. 9. Hexavalent chromium reference dose level has been reduced since the ROD was written,

indicating that hexavalent chromium is a more toxic metal than what was evaluated in the ROD.


All recommendations presented in this section pertain to the Building 225 Chromium Spill site (site SS027) only. Additional details regarding these recommendations are available from the SS027 Site Summary found in Section XIII. Institutional Controls 1. When signs are replaced or additional signs are added, change the warning sign verbiage to

provide a warning of the presence of contaminated soils that could pose a hazard if exposed. For example: “Caution: Do not disturb floor or soil under floor. Disturbance could cause exposure to contaminated soils. Contact EMR, 7-7890.”

Inspection and Maintenance Program 2. Remedy defects in floor slab as soon as they are identified to ensure minimal infiltration.

Floor slab cracks are scheduled for repair during 2003. 3. Replace tape, which outlines the areas of attainment, with another method of delineation.

[The marking tape is scheduled for replacement during 2003.] Performance Monitoring 4. Investigate the source of elevated hexavalent chromium concentrations in the groundwater

underlying the SS027 site. Investigate potential remedial options if necessary.


5. Establish an appropriate action level for an increase in soil moisture content based on soil moisture results.

6. Determine what actions should be taken if an increase in soil moisture content occurs at a particular depth.

7. Annual reporting is inadequate to determine if neutron logging data are being compared to the previous logging event and the baseline log developed during initial installation of soil moisture probe locations. The annual report should be modified to capture current, historical, and baseline data for all intervals to ensure proper evaluation of these data.

8. Schedule soil moisture data collection in the same months of each year to ensure comparable results.

9. Incorporate historical data from annual reports and current neutron logging data at all intervals into ERPIMS to ensure data availability for future comparisons.

General 10. Review the PSVP and ensure either the LTM or O&M contractor is addressing all aspects of

monitoring and reporting. 11. Re-evaluate risk analysis due to change in hexavalent chromium reference dose levels.


The remedy at OU 7 is protective of human health because there is no pathway for exposure. However, there is adverse impact to the environment based on concentrations that exceed MCLs in the groundwater directly below the Building 225 Chromium Spill site (Site SS027) and evidence of downgradient contamination. The actions outlined in the recommendations need to be addressed to ensure continued protectiveness, particularly identification of the source and fate of increasing hexavalent chromium concentrations in groundwater. Based on the results of these investigations, potential remedial options should be identified.

XI Next Review The next FYR for OU 7 is required by 2008. No future review is required for Building 220

Underground Tanks (site ST031), Building 225 PCB (site SS032), Sill Property, Layton (site SS028), or the Building 204 Beryllium Underground Waste Tank (site OT029).


(CH2M 1997) Draft Final South Area of Operable Unit 9 Site Inspection - Final Comprehensive Data Evaluation, CH2M Hill, October 1997. (EPA 1990) Guidance for Remedial Actions for Superfund Sites with PCB Contamination, Environmental Protection Agency, August 1990. (EPA Region III 2002) Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB CE 1957) Building 205 Record Drawing, Installation of Lines and Tanks for Industrial Waste, Buildings 225 and 205, Sheet 1, Hill Air Force Base Civil Engineering, December 1957.


(HAFB EMR 1989) PCB Spill Sampling and Cleanup in Building 225, Hill Air Force Base, Utah, Hill AFB EMR, November 1989. (HAFB EMR 1991) Final Decision Document for Site SS28, Sill Property, Hill AFB EMR, June 1991. (HAFB EMR 1995) Record of Decision for Operable Unit 7, Hill AFB EMR, September 1995. (HAFB EMR 1998a) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (HAFB EMR 1998b) Final Decision Document for IRP Site OT 029 Category III NFRAP Building 204 Beryllium Underground Waste Tank, Hill AFB EMR, March 1998. (JMM 1991) Site Characterization Report for a Portion of Building 225 and Site Investigation of Fill Soils at Base Supply Well 6, James M. Montgomery, Consulting Engineers, December 1991. (MW 1995) Remedial Investigation/Feasibility Study Report for Operable Unit 7 (IRP Sites SS27, ST31, & SS32) Volume I (Text), Montgomery Watson, February 1995. (MW 1996) Remedial Design/Remedial Action Work Plan for Operable Unit 7, Montgomery Watson, August 1996. (MW 1998) Annual Report for Operable Unit 7, Montgomery Watson, December 1998. (MW 1999) Annual Report for Operable Unit 7 Building 225 Floor Slab, Montgomery Watson, November 1999. (URS 2002) 2001 Operation and Maintenance Report Building 225 Floor Slab Operable Unit 7 Hill Air Force Base, Utah, URS, March 2002.



OU 7 OPERABLE UNIT 71992 Remedial Investigation/Feasibility

StudyThe RI/FS activities for OU 7 began in the latter part of 1992 and continued until early 1995 (MW 1995).


02 1995 RI/FS Completed A Remedial Investigation/Feasibility Study of OU 7 began in the latter part of 1992 and continued to 1995. The Remedial Investigation confirmed the presence of contaminants inside of Building 220, at Base Supply Well 6, in Building 225, at the PCB spill area, and in the former Metal Plating Shop area. In addition, four other possible source areas were investigated inside of Building 225, including the Mop Cleaning Room, a former TCE Degreaser Pit, the former Wash Rack, and the Hydraulic Room.


09 1995 ROD Completed The ROD established RAOs and remedial actions for the active OU 7 site (SS027). Two sites (Sites ST031 and SS032) were closed and do not require any remedial actions.


SS027 BLDG 225 CR SPILL1940 Plating Shop in Operation A Metal Plating Shop was formerly located along the east side

of Building 225. The plating shop operated from the 1940s until it was removed from Building 225 in 1972.






1968 Plating Area Expanded The operation expanded and occupied additional space in Building 225. Approximately 150 tanks were used for various plating operations. The expansion included the addition of two new chromium plating areas, for a total of three chromium plating lines.

Site Characterization Report for a Portion of Building 225 and Site Investigation of Fill Soils at Base Supply Well 6

1989 Preliminary Assessment Soil contamination was first identified beneath the former Metal Plating Shop area when a utility trench was installed in 1989.


1990 Site Characterization During February and March 1990, a site characterization study for the portion of Building 225 that housed the Metal Plating Shop was performed. The objective of this study was to evaluate the nature and extent of metals contamination present beneath the floor in Building 225; assess if the fill placed at Base Supply Well 6 was hazardous; and assess the need for further investigation of the soils beneath Building 225.

Remedial Investigation/ Feasibility Study Report for Operable Unit 7 (IRP Sites SS27, ST31, & SS32) Volume II (Appendices A-L)

ST031 B220 UNDERGROUND TANKS1957 Building 220 Constructed This building was constructed in 1957 and was used as aircraft

painting and paint stripping facility. Painting and paint stripping activities have used many types of paints, paint strippers, solvents, acids, and other chemicals. Three underground concrete separator tanks were located on the northwest side of the building. These tanks were used to separate paint chips and sludge from the wastewater solutions generated during paint stripping operations. Wastewater from the tanks was discharged to the industrial wastewater pipeline and the IWTP.






1984 Phase I design and cost estimate Radian Corporation collected samples of wastewater generated from Building 220, conducted treatability studies, and prepared a report recommending a wastewater treatment system design.


1984 Environmental Investigation An initial environmental investigation at Building 220 characterized the industrial wastewater generated by the paint stripping and painting activities. Wastewater was generally characterized by elevated levels of oil and grease, total suspended solids, chemical oxygen demand, and acidity. The majority of the organics in the wastewater are VOCs. Paint and degreasing solvents, along with BNAEs including phthalates and polynuclear aromatic hydrocarbons were also present in the wastewater.


1985 UST Investigation at Bldg 220 Radian investigated three underground storage tanks at Building 220 suspected of releasing contaminants to the underlying soils and groundwater. Field work was conducted during October and November 1985.


1985 Soil Removal Before the building addition was constructed, some of the contaminated soils was removed and taken to an off-Base hazardous waste disposal facility (no date given in literature, therefore date is approximate).






1986 Building 220 renovated Building 220 was renovated in 1986 and expanded over an area that contained the three underground separator tanks. As part of this renovation, the three underground separator tanks and a 20,000-gallon fuel storage tank located in the vicinity were excavated and removed. Because previous investigations indicated that environmental contamination was present in the soils beneath the USTs, Hill AFB personnel collected several soil samples in May 1987 following tank removal.


06 1987 Additional sampling Additional groundwater samples were collected during June 1987. 51 soil samples and 13 groundwater and potable water samples were collected. Various inorganic and organic contaminants were detected in both the soil and groundwater in the vicinity of Building 220. However, due to problems with quality control samples some of the data were suspect.


1992 Remedial Investigation/Feasibility Study

The RI/FS activities for OU 7 began in the latter part of 1992 and continued until early 1995 (Montgomery Watson, 1995). To identify potential contamination sources, both sampling around and inside of Building 220 was completed during the RI. Organic compounds detected included several BNAEs, VOCs, furans, and PCBs. In addition, numerous metals were detected above background although, with the exception of arsenic and beryllium, none of these organic compounds or the metals above background were present in concentrations that exceeded those listed in the RBC table.

Remedial Investigation/Feasibility Study Report for Operable Unit 7 (IRP Sites SS27, ST31, & SS32) Volume I (Text)

09 1995 ROD Completed Based on the findings of the OU 7 RI and Risk Assessment, Building 220 does not require remedial actions because either the risks posed by the contaminants at this site were not significant or the concentrations for the contaminants were within background levels.






SS032 BLDG 225 PCB1960 Preliminary Assessment This area was the site of a former transformer storage area

that was removed in the 1960s.Record of Decision for Operable Unit 7

1989 PCB Contaminated Soils Found in Excavation by Building 225

During the summer of 1989, a utility trench excavation in Building 225 revealed the presence of PCB-contaminated soils. Personnel from Hill AFB conducted a preliminary soil sampling program, prepared a brief cleanup and closure plan, removed PCB-contaminated soil, and conducted a post-removal sampling program to allow the utility trench construction project to be completed.


1989 Site Inspection Polychlorinated biphenyls were found in soil beneath Building 225 approximately 100 feet west of the former Metal Plating Shop. During excavation of a utility trench in 1989, unusual odors and discolored soil were reported. A subsequent investigation revealed that the soil contained PCBs.


1989 Preliminary Assessment Circa 1989, 95 tons of contaminated soil were removed and disposed of at a facility permitted by the Toxic Substances Control Act. Following the soil removal, confirmation soil samples taken from the walls of the excavation revealed that only insignificant concentrations (less than 0.23 mg/kg) of residual PCBs remained in localized areas.






09 1995 ROD Completed Based on the findings of the OU 7 RI and Risk Assessment, SS032 does not require remedial actions because either the risks posed by the contaminants at this site were not significant or the concentrations for the contaminants were within background levels.


SS028 SILL PROPERTY, LAYTON1989 Chromium-contaminated soil

placed at the Sill FarmIn early 1989, chromium-contaminated soil and rubble from Hill AFB (Building 225 excavation) was inadvertently placed as fill at two locations on the Sill Farm in Layton, Utah.

Final Decision Document for Site SS28, Sill Property

03 1989 Soil Removal Action The initial removal action for the chromium-contaminated soil at the Sill Property was completed between 18 March 1989 and 25 March 1989. Approximately 327 tons of material were removed from the south site and 163 tons from the north site.


09 1990 Additional Soil Removal As requested by the Utah Bureau of Solid and Hazardous Waste, a subsequent sampling and removal operation was conducted. Two dump truck loads of soil from a localized portion of the north removal site were excavated and trucked offsite on 12 September 1990.


02 1991 Final Summary Report of Chromium Cleanup at Two Sites in Layton, Utah

This document summarized the study methodology and presents findings and conclusions regarding the cleanup of the Sill Farm.

Final Summary Report for Chromium Cleanup at Two Sites in Layton, Utah





06 1991 NFRAP No further action planned document completed for the Sill Property.


OT029 B-204 BE1957 Tank Installation A 1,000-gallon hypochlorite above-ground storage tank and a

5,000-gallon industrial waste underground storage tank were installed at the site during 1957 or 1958.

Final Decision Document for IRP Site OT 029 Category III NFRAP Building 204 Beryllium Underground Waste Tank

1987 Tank Removal During 1987, an AST and an UST were removed from the Building 205 area. Both tanks were located in close proximity to the east side of existing Building 205 and the northern side of former Building 204. Reportedly, the AST was used to store hypochlorite. The UST was used to store industrial wastes, including beryllium-related wastes, associated with previous operations conducted at existing Building 205.


03 1998 NFRAP No further action was selected as the final remedy for the Building 204 Beryllium Underground Waste Tank.





OU 7 SS027 BLDG 225 CR SPILL


III. Background The former Metal Plating Shop was located along the east side of Building 225. Contents of the plating solution tanks containing acids, bases, metal salts, and other chemicals were frequently discharged into a floor drain system that was connected to the industrial waste pipeline. Over time, the plating solutions corroded the drains and piping and discharged liquids leaked into the subsurface soil.

A Site Characterization (SC) Study (JMM 1991) preceded the RI in the former Metal Plating Shop area. During the SC, 20 soil borings were drilled to 15 feet bgs and 90 soil samples were collected. All soil samples from the SC Study were analyzed for total chromium, hexavalent chromium, cadmium, lead, silver, and soil pH. Because the SC left a data gap regarding the depth of the contamination, the OU 7 RI included drilling and sampling three deep soil borings and one monitoring well boring. The deep soil borings were designed to evaluate the nature and vertical extent of soil contamination beneath the plating shop area, and were drilled to depths of 50 feet bgs or greater. Additionally, the monitoring well boring was drilled and sampled to approximately 10 feet below the water table (a total depth of 127 feet bgs) (MW 1995).

Based on the OU 7 RI data and data from the SC study, contaminants present beneath the former Metal Plating Shop are limited to low levels of several VOC and high levels of several metals. While VOCs were detected at less than 0.1 mg/kg, hexavalent chromium and cadmium were detected in concentrations up to 1600 and 220 mg/kg, respectively. Concentrations of total chromium were also detected above background but the concentrations were not high enough to exceed the health risk-based concentrations.

I. Introduction Three areas associated with Building 225 have been investigated (MW 1995) as a part of the SS027 site. The first area was the former Metal Plating Shop Area, which had cadmium and hexavalent chromium contamination above background levels and health based-risk concentrations. The second area, called Miscellaneous Areas, was located within Building 225 and included the former Wash Rack, the former Degreaser Pit, the Hydraulic Room, the Mop Cleaning Room, and the Industrial Wastewater pipeline connection. None of these miscellaneous areas had concentrations of contaminants detected above risk-based levels and are therefore not included in the remainder of this summary. The third area was Base Supply Well 6, where approximately 25 tons of potentially contaminated soil from the Building 225 excavation was placed. This site investigation revealed that the fill placed at Supply Well 6 was from an uncontaminated portion of the utility trench and that no further action was necessary. This area is also therefore not included in the remainder of this summary. The former Metal Plating Shop area is the only remaining active site with elevated levels of contamination in excess of health risk standards. The ROD for OU 7 (HAFB EMR 1995) selects the following remedies for this site: groundwater monitoring in areas upgradient, beneath, and downgradient of the area, soil moisture content monitoring, maintaining and preserving the building and floor slab that overlay the contaminated soils, and institutional controls.





Concentrations of arsenic and beryllium exceeded health based-risk concentrations, but these concentrations were within the range considered representative of background. Metals concentrations observed in soils outside of the former Metal Plating Ship area are significantly lower than the risk-based concentrations (MW 1995).

The contaminants of concern for this site based on the SC and the RI are cadmium and hexavalent chromium. Preliminary remediation goals are identified in the ROD for OU 7 (HAFB EMR 1995).


The selected remedy at Site SS027 consists of applying institutional controls, conducting an inspection and maintenance program for the floor slab in the area of the former Metal Plating Shop, and conducting soil moisture measurements and groundwater quality monitoring. Institutional controls consist of a continuing order from the Base Commander (HAFB 1998) to restrict worker access, deed restrictions, and warning signs (HAFB EMR 1995). The inspection and maintenance program consists of an annual inspection of the floor slab delineated by three areas of attainment intended to ensure that cracks or fractures that could provide a means of transporting fluids to the sub-floor soil or expose workers to contaminated soil are repaired. The areas of attainment were delineated based on contaminant concentrations detected in the RI phase. The performance monitoring includes semi-annual monitoring of soil moisture content at six monitoring locations and groundwater quality at three wells (one upgradient, one within the source area, and one downgradient) (MW 1998).


No actions were identified for this site in the 1998 FYR (HAFB EMR 1998). Institutional controls, the inspection and maintenance program, and performance monitoring have continued per the schedule set forth in the Final Remedial Design/Remedial Action Work Plan for Operable Unit 7 dated August 1996.





SOIL CADMIUM 7.57 mg/kg

SOIL CHROMIUM, HEXAVALENT 1.16 mg/kg

* Reduce contaminant concentrations to meet risk levels and/or reduce contaminant transport to rates that will not impact groundwater quality above Maximum Contaminant Levels.* Reduce contaminant transport within source areas and reduce chemical transport from soil to groundwater by minimizing surface water infiltration.* Prevent human exposure to contaminated soil through ingestion, inhalation, and dermal contact, such that the additional risk to an individual for cancer is below 1 x 10-6 and the non-cancer threshold is less than 1.0.





Question A (Answer)

No


The intended function for the remedy in place at Site SS027 is summarized by the RAOs for this site. Two of the three RAOs are not being achieved. First, reduction of contaminant transport within the source areas by minimizing surface water infiltration may not be realized. Annual site inspections identified defects in the floor slab which had been noted during previous annual inspections that have not been repaired. These defects could provide a conduit for infiltration of water through the floor slab. Second, reduction in contaminant transport to rates that will not impact groundwater quality above MCLs is not being achieved. The hexavalent chromium concentrations within the source area are above the groundwater MCL for total chromium (no MCL exists for hexavalent chromium in groundwater) and have been since 1996 (pre-ROD hexavalent chromium concentrations were below MCLs). Additionally, the concentrations downgradient of the source areas consistently demonstrate chromium concentrations higher than concentrations upgradient, suggesting that transport of contaminants from the site is occurring.

One of the areas of attainment does not contain any soil moisture probes. Soil moisture compliance in this area cannot be evaluated.

Question B (Answer)

No

Question B (Comment) The reference dose for hexavalent chromium has changed from 0.005 to 3E-5 in soil (100

times more stringent) per EPA Region III RBC table (10/2002). The RAOs do not need to be modified in light of this change because the RAOs state "MCLs" and do not specify the level.

Question C (Answer)

Yes


The warning signs within the areas of attainment do not warn area personnel of the contaminated soils underlying the floor slab or of a threat to human health if exposed to the soil. The absence of such a warning may cause unsuspected and unreported exposures.

Groundwater concentrations exceeding MCLs for chromium were reported in the 1999 Annual Report (MW 1999) and no action has been taken to determine the root cause of this issue. Also, defects likely affecting infiltration were reported in the 2001 Annual Report (URS 2002). Through conversations with site personnel, the O&M contractor indicated during the site inspection that the floor is being washed on a regular basis. Infiltration has increased due to the unrepaired defects in the floor slab.

VIII. Issues Institutional Controls






* Warning signs within Building 225, SS027, are not in compliance with ROD intent. Per the ROD, the selected remedy at OU 7 includes: "Posting warning signs regarding the presence of contaminated soils that could represent a threat to human health." The signs currently posted say, "Caution: Do Not Disturb Floor, Contact EMR, Phone 7-8790". The current signs do not inform area personnel of the contaminated soils in the areas of attainment underlying the floor slab or of a threat to human health.

Inspection and Maintenance Program* Defects that affect infiltration rates recommended for repair in the 2001 annual report (URS 2002) have not been repaired at the time of this review.* The tape delineating the areas of attainment is in disrepair (torn, peeling, etc.).

Performance Monitoring* Hexavalent chromium concentrations above total chromium MCLs have been measured in the groundwater underlying the floor slab since 1996.* Downgradient concentrations of hexavalent chromium are above the upgradient concentrations suggesting a release of contaminants to the aquifer at Building 225.* Soil moisture monitoring objectives and process are not clear (i.e., Action levels for a soil moisture increase are not clearly identified nor is an action plan in place if an action level is reached. Data comparison is completed at one interval (7-8 feet bgs) only and no rationale for reviewing only that depth is given. Historically logging has not been performed during the same months of the year.).* No soil moisture data are available in ERPIMS to facilitate a thorough performance review for the floor slab remedial action.

General* PSVP recommendations have not been incorporated fully into the LTM and O&M contracts to ensure monitoring and reporting is comprehensive.* Hexavalent chromium reference dose level has been reduced since the ROD was written, indicating that hexavalent chromium is a more toxic metal than what was evaluated in the ROD.

IX. Recommendations Institutional Controls* When signs are replaced or additional signs are added, change the warning sign verbiage to provide warning of presence of contaminated soils that could pose a hazard if exposed. For example: "Caution: Do not disturb the floor or soil under the floor. Disturbance could cause exposure to contaminated soils. Contact EMR, 7-7890."

Inspection and Maintenance Program * Correct defects in floor slab as soon as they are identified to ensure minimal infiltration. Floor slab cracks are scheduled for repair during 2003.* Replace tape, which outlines the areas of attainment, with another method of delineation. [The marking tape is scheduled for replacement during 2003.] Performance Monitoring* Investigate the source of hexavalent chromium concentrations in the groundwater underlying the SS027 site.






2008

* Establish an appropriate action level for an increase in soil moisture content based on soil moisture results. * Determine what actions should be taken if an increase in soil moisture content occurs at a particular depth.* Annual reporting is inadequate to determine if neutron logging data are being compared to the previous logging event and the baseline log developed during initial installation of soil moisture probe locations. The annual report should be modified to capture current, historical, and baseline data for all intervals to ensure proper evaluation of these data.* Schedule soil moisture data collection in the same months of each year to ensure comparable results.* Incorporate historical data from annual reports and current neutron logging data at all intervals into ERPIMS to ensure data availability for future comparisons.

General* Review the PSVP and ensure all aspects of monitoring and reporting are being addressed by either the LTM or O&M contractor.* Re-evaluate risk analysis due to change in hexavalent chromium reference dose levels.



The remedy associated with SS027 is protective of human health because there is no pathway for exposure. However, there is an adverse impact on the environment based on hexavalent chromium concentrations that exceed MCLs in the groundwater directly below the Building 225 Chromium Spill site and evidence of downgradient contamination. The actions outlined in the recommendations need to be addressed to ensure continued protectiveness, particularly identification of the source and fate of increasing hexavalent chromium concentrations in groundwater. Based on the results of these investigations, potential remedial options should be identified.




OU 7 ST031 B220 UNDERGROUND TANKS

II. Site Chronology See Table OU 7-2 for a history of events at this site. The table is organized first to describe events, which impacted the whole OU, followed by events impacting only specific IRP sites within the OU.

III. Background During the RI for Building 220 site, sources of contamination both internal and external of the building were investigated. The results of this investigation are detailed below.

INTERNAL BUILDING 220 INVESTIGATIONSoil samples from beneath the floor drains in the southern part of Building 220 had VOC concentrations less than 1 mg/kg with few exceptions. Additionally, gasoline and unknown hydrocarbons were detected in concentrations from 69 mg/kg to 140 mg/kg. Soil samples from beneath the former oil/water separator tank locations in the northern portion of the building had detectable organic compounds and metals above background. Organic compounds detected include several Base-Neutral-Acid Extractables (BNAEs) (in concentrations between 0.5 and 2.1 mg/kg), VOCs (in concentrations between 0.0017 and 0.044 mg/kg), Furans (in concentrations between 11 and 18 ug/kg), and PCBs (at concentration of 1.4 mg/kg). In addition, numerous metals were detected above background levels although, with the exception of arsenic and beryllium, none of these organic compounds or the metals above background levels were present in concentrations that exceed those listed in the risk-based concentration table (MW 1995).

EXTERNAL BUILDING 220 INVESTIGATIONSoil gas sampling and soil sampling around the perimeter of Building 220 and the IWTP detected low concentrations of VOCs over a broad area. VOCs most commonly detected include 1,1-DCA, 1,1,1-TCA, TCE, MEK, and toluene. The highest concentrations of VOCs were west of Building 220 where the Building 220 Industrial Wastewater Pipeline (IWP) exits and connects with the IWTP. Soil sampling in this and other areas around the perimeter of Building 220 indicated 1,1,1-TCA and TCE concentrations below the respective risk-based standards. Metals concentrations detected were within the ranges seen elsewhere at OU 7. Based on these sampling results, it appears that the IWP between Building 220 and the main IWTP has released low levels of VOCs and possibly some metals to the soils that underlie it, but no significant source areas were identified (MW 1995).

ARSENIC AND BERYLLIUM CONTAMINATIONArsenic and beryllium were excluded as chemicals of concern based on the following information:*Arsenic and beryllium were identified as being slightly elevated compared to background concentrations in OU 7 source areas. However, when additional information from elsewhere at Hill AFB is considered (as discussed below), arsenic and beryllium are, in fact,

I. Introduction Building 220 is located east of Building 225 and adjacent to the main runway. Building 220 was constructed in 1957 and has been used as an aircraft painting and paint stripping facility. Based on the findings of the OU 7 Remedial Investigation and Risk Assessment, Building 220 does not require remedial actions or additional removal actions because the risks posed by the contaminants at the site are below significant levels. Therefore, no further remedial actions are planned at this site.





representative of background concentrations and should not be considered contaminants. Therefore, the risks greater than 1E-6 reported in the Baseline Risk Assessment (MW 1995) are due to background conditions and not attributable to activities at OU 7.* These metals were not used as part of any known industrial process at OU 7.* The upper control limits for these metals occur at concentrations within background ranges identified at Operable Units 1, 2, and 4.* The highest beryllium concentrations detected occur in Building 220 at depths below 48 feet bgs. Beryllium was reported at lower concentrations or was not-detected at depths above 48 feet bgs, further suggesting that the beryllium represents background concentrations and was not released from industrial processes occurring at the surface. * The distribution of arsenic and beryllium in the soils beneath the potential source areas is not consistent with those of other environmental contaminants known to have been released at OU 7 (MW 1995).

Based on the findings of the OU 7 Remedial Investigation and Risk Assessment, Building 220 does not require remedial actions or additional removal actions because the risks posed by the contaminants at the site are below significant levels.


In the mid-1980s, some of the contaminated soil was removed and taken to an off-Base hazardous waste disposal facility before the building addition was constructed. No mention was made in the literature regarding why or how much soil was removed. Soil sampling results indicated that only low concentrations of organic chemicals (VOCs, fuel hydrocarbons, semivolatile organic compounds (SVOCs), PCBs, and chlorinated dibenzofurans) and metals are present in the vicinity of the former separator tanks, pipeline locations, and around the perimeter of Building 220.


The ROD, published in 1995, established that contaminants at this site are below significant levels. Therefore, this site was not a part of the 1998 Five-Year Review and no actions have been completed at the site since the ROD date of 1995.


Question A (Answer)

Not Applicable





NA NA - Site under NFRAP status, elevated concentrations of contaminants determined to be naturally occuring.

NA

* Not applicable. No CoCs remain at this site that are above risk-based and background levels, therefore no RAOs have been developed.








Not applicable. There is no remedy at this site.

Question B (Answer)

Not Applicable


No additional remedial or removal actions are required.

Question C (Answer)

Not Applicable


No remedies are in place at this site.

VIII. Issues None.

IX. Recommendations No further action is required at this site.



ST031 was recommended for NFRAP status and accepted in 1995 because the risks posed by the contaminants at the site are below significant levels (MW 1995).




OU 7 SS032 BLDG 225 PCB

II. Site Chronology See Table OU 7-2 for a history of events at this site. The table is organized first to describe events, which impacted the whole OU, followed by events impacting only specific IRP sites within the OU.

III. Background During the summer of 1989, a utility trench excavation in Building 225 revealed the presence of PCB-contaminated soils. Hill AFB EMR personnel collected 13 soil samples along the length of the planned Building 225 utility trench excavation and submitted them for PCB analysis (see Figure OU 7-1.) Because one of the soil samples contained nearly 0.5% PCBs, a soil cleanup and removal action had to be conducted before the construction project proceeded. The cleanup consisted of collecting soil samples to delineate the extent of PCB contamination, excavating and disposing of the PCB-contaminated soils, installing concrete forms to isolate the outside trench walls, backfilling the open area between the forms and the trench walls with clean imported fill, and capping the backfilled areas with new concrete. On 30 October 1989, this removal action commenced and an area measuring 25 ft x 10 ft x 6 ft deep was excavated, and 97.5 tons of PCB-contaminated soils were removed from this utility trench. All of the excavated soil was taken to a Toxic Substances Control Act (TSCA)-permitted landfill cell in western Utah (MW 1995).

After the removal action, additional soil samples were collected from the bottom and walls of the excavation adjacent to the contaminated soils and from several other locations along the trench excavation. The results of these analyses indicate that concentrations of PCBs remaining in areas adjacent to the cleanup excavation were low, with the exception of a sample collected from the west wall of the trench, which contained 12,000 ppb PCBs. Hill AFB proposed leaving potentially PCB-contaminated soils located outside the excavation areas in place because they would be capped and would present no future health threats (MW 1995).

The PCB spill area in Building 225 was included in the OU 7 RI to assess the effectiveness of the PCB spill cleanup completed by Hill AFB in 1989 (HAFB EMR 1989) and evaluate the extent of any residual PCB contamination. RI activities at the PCB spill area consisted of drilling and sampling 12 shallow soil borings closely spaced around the cleanup area. Soil sampling in the PCB spill area identified little residual PCB contamination. PCBs were detected in only two shallow samples from borings immediately adjacent to the PCB cleanup

I. Introduction During excavation of a utility trench in 1989, unusual odors and discolored soil were reported. A subsequent investigation revealed polychlorinated biphenyls (PCBs) in soil beneath Building 225, approximately 100 feet west of the former Metal Plating Shop within Building 225 (see Figure OU 7-1).This area was the site of a former transformer storage area that was removed in the 1960s. As part of a cleanup effort, 95 tons of contaminated soil were removed and disposed of at a facility permitted through the Toxic Substances Control Act Permit Program. Following the soil removal, additional soil samples revealed that only insignificant concentrations (less than 0.23 mg/kg) of residual PCBs remained in localized areas. Based on the findings of the OU 7 Remedial Investigation and Risk Assessment (MW 1995), the PCB Spill Area does not require remedial actions because risks posed by the contaminants at this site are below significant levels (cancer risk less than 1E-6 and health hazard less than 1 for contaminants of concern).





excavation. With these two exceptions, none of the other borings contained detectable concentrations of PCBs. Based on these results, it appears that only isolated areas immediately adjacent to the PCB cleanup excavation still contained residual PCB contamination. However, because the concentration of PCBs in one sample (0.23 ppm) exceeded the risk-based concentration, health risks associated with PCB contamination are addressed in the Baseline Risk Assessment (MW 1995).

PCB [namely PCB 1254] has been excluded as a contaminant of concern and is not carried through the FS for the following reasons:

*PCB 1254 was detected in only one of 38 samples at a concentration of 0.23 ppm. According to Guidance on Remedial Actions for Superfund Sites With PCB Contamination (EPA 1990), the recommended soil action level is 1 ppm for residential land use and 10 to 25 ppm for industrial land use. The maximum PCB concentration in the PCB Spill Area is less than one-fourth of the recommended residential action level (MW 1995).

*The baseline risk assessment calculated cancer risk of 3E-6 is only slightly above the cancer threshold value (1E-6). Because of the conservative nature of many of the assumptions used to calculate the exposure doses for ingestion and dermal contact, the actual cancer risk at the site is most likely less than the threshold value (MW 1995).

*In order to calculate environmental data statistics, non-detect results were replaced with a value equal to one-half the sample quantitation limit. This produces an additionally conservative exposure dosage as values of one-half the detection limit are likely to be high. This is especially the case when the majority of the sample set contains non-detect values. In the case of the Building 225 PCB Spill Area, 95 percent of the samples had non-detect values (MW 1995).

Results of the BRA and current operations performed at OU 7 source areas indicate that under the existing conditions, there is negligible potential for exposing receptors to contaminated soil or contaminated groundwater. This is because there are insignificant health risks (cancer risk less than 1E-6 and health hazard less than 1 for contaminants of concern) associated with the contaminated soil in and around the PCB Spill Area (MW 1995).

Based on the findings of the OU 7 Remedial Investigation and Risk Assessment, the PCB Spill Area does not require remedial actions because risks posed by the contaminant at these sites are below significant levels (HAFB EMR 1995).




SOIL NA - Removal action resulted in CoCs being removed from site.

NA

* Not applicable. No further remedial or removal action planned.








Just over 97 tons of PCB-contaminated soil were removed from the site and disposed of in a TSCA-approved facility in 1989. Additional remedial actions are not required because the risks posed by the remaining contaminants are below significant levels (cancer risk less than 1E-6 and health hazard less than 1 for contaminants of concern).


The ROD, completed in September 1995, stated that site SS032 did not require remedial actions. Therefore, no activity has been carried out at the site since the last review in 1998.


Question A (Answer)

Not Applicable


No remedy is in place at this site. The site is closed.

Question B (Answer)

Not Applicable

Question B (Comment) No additional remedial or removal actions are required.

Question C (Answer)

Not Applicable


No additional remedial actions are in place at this site.

VIII. Issues None.

IX. Recommendations No further action is required at this site.



SS032 was recommended for NFRAP status and accepted in 1995 because risks posed by the contaminant at these sites are below significant levels (cancer risk less than 1E-6 and health hazard less than 1 for contaminants of concern) (HAFB EMR 1995).





OU 7 SS028 SILL PROPERTY, LAYTON

II. Site Chronology In early 1989, chromium-contaminated soil and rubble from Hill AFB (Building 225 excavation) was inadvertently placed as fill material at two locations on the Sill Property in Layton, Utah (see Figure OU 7-1).

An initial removal action for the chromium-contaminated soil at the Sill Property was completed between 18 March 1989 and 25 March 1989. Approximately 327 tons of material were removed from the south site and 163 tons from the north site and taken to a RCRA-approved facility (HAFB EMR 1991).

As requested by the Bureau of Solid and Hazardous Waste (BSHW), a subsequent sampling and removal operation was conducted. Two dump truck loads of soil from a localized portion of the north site were excavated and trucked off-site to a RCRA-approved facility on 12 September 1990 (HAFB EMR 1991).

This site was granted no further action planned (NFRAP) status in June 1991.

III. Background This site is farm land, where inert materials (soil, concrete, rubble) were accepted to fill in ephemeral stream gullies running through the property. Fill material was accepted from various sources. In early 1989, chromium-contaminated soil and rubble from Hill AFB was inadvertently placed as fill at two locations on this farm in Layton, Utah (HAFB EMR 1991).

Contaminated soil and concrete rubble fill were placed at two locations on the Sill Property. Samples of contaminated fill materials were collected and analyzed from both the soils remaining at the source area in Bldg 225, and from those transported to the Sill's Farm. The sampling results indicated that chromium was the principal contaminant present in both the source area and removal site soils. The extent of the chromium contamination was limited. Cleanup activity at both sites consisted of removing all fill material exhibiting yellow staining or suspected of originating from the Bldg 225 utility trench excavation. As requested by the Bureau of Solid and Hazardous Waste, a subsequent confirmation sampling round was conducted resulting in an additional removal action. Two dump truck loads of soil from a localized portion of the north site were excavated and trucked offsite on 12 Sept 1990. All contaminated soils were disposed of in a RCRA landfill (HAFB EMR 1991).

Following the excavation of contaminated soils, a comparison of EP Toxicity extract to toxicity thresholds for chromium indicate that the soils at both removal sites were not considered hazardous with respect to chromium. A statistical comparison was the primary method used to evaluate the cleanup of the two chromium removal sites. This method was

I. Introduction Chromium-contaminated fill, excavated from Building 225, was placed at two locations on the Sill Property located approximately 1 mile south of Hill AFB in Layton, Utah. Two removal actions were completed in accordance with RCRA and testing concluded that the remaining soil poses no additional threats to human health and the environment. A decision document, completed in 1991, concluded that no further removal or remedial action is required at this site since all detectable traces of chromium in contaminated soil have been removed from the site (HAFB EMR 1991). This site is included in the 2003 Five-Year Review for completeness to document the site's history.





selected to differentiate the Bldg 225 material from other fill at the site. The statistical analysis found no significant difference between the sample populations from the removal areas and those from the fill from other sources, and it was concluded that Bldg 225 materials had been removed from the two areas included in the statistical analysis. All the evidence collected at both cleanup sites indicated that the objectives of the cleanup operation had been achieved (HAFB EMR 1991).

Concerns for human health and the environment have been addressed with regard to migration to groundwater, ingestion of chromium-contaminated soil, and inhalation of chromium-contaminated soil particles. The scenarios are based on small areas or cells which continued to test positive for chromium levels after removal action had taken place and represent worst case conditions for health effects associated with the contamination. All data support the conclusion that chromium contamination from Hill AFB Building 225 fill dirt deposited at the Sill Property has been effectively cleaned and poses no health threats from any type of contact with the remaining soil (HAFB EMR 1991).


No additional removal actions or remedial actions are required.


This site had a decision document in 1991 stating that no further remedial action is planned. Therefore, this site was not covered in the 1998 Five-Year Review.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable


Not applicable. No additional removal actions or remedial actions are required.





SOIL NA - Removal action resulted in CoCs being removed from site.

NA

* Not applicable. No CoCs remain at this site, therefore no RAOs have been developed.







Question C (Answer)

Not Applicable



VIII. Issues None.




SS028 was recommended for NFRAP status and accepted in 1991 because all detectable traces of chromium in contaminated soil have been removed from the site (HAFB EMR 1991).




OU 7 OT029 B-204 BE


III. Background Two tanks, one UST and one AST, were installed in 1957 and were located adjacent to the eastern side of existing Building 205. The UST was used to store beryllium wastes associated with landing gear repair operations formerly located in Building 205. Periodically, the wastes were removed from the UST and transported to Landfill 5 at the Utah Test and Training Range for disposal. The AST stored hypochlorite which was also used in the repair of aircraft landing gear. The location of the tanks was obtained from the Building 205 Record Drawing, Installation of Lines and Tanks for Industrial Waste, Building 225 and 205 (HAFB CE 1957).

Both tanks were removed from the site in 1987, after landing gear repair operations were transferred to Buildings 505, 507, and 510. Samples of soils under the UST may have been taken during removal of the tanks; however, there is only limited documentation regarding the UST removal activities. The UST closure documentation did not include analytical data. Due to the limited amount of documentation available, the site was investigated as part of the South Area of Operable Unit 9 (OU 9) Site Inspection. The results of the OU 9 Site Inspection investigation are also presented in the Final Comprehensive Data Evaluation for the South Area of Operable Unit 9 (CH2M 1997).

Hill Air Force Base recommended no further action at IRP Site OT029 in March 1998. HAFB initiated and implemented detailed response actions including: tank removal, soil and groundwater investigative activities, and risk assessment review. The investigative activities involved soil and groundwater sampling, laboratory testing, risk analysis, and reporting. The results of the investigative activities revealed that residual contaminant constituent concentrations in soil and groundwater are below risk-based action levels. The risk-based action levels are protective of human health and the environment. Therefore, IRP Site OT029 poses no unacceptable risks to human health or the environment (HAFB EMR 1998b).

I. Introduction Site OT029, also known as the Building 204 Beryllium Underground Waste Tank, is located immediately east of existing Building 205 and south of existing Buildings 204 and 206 (see Figure OU 7-1). A 1,000-gallon hypochlorite above ground storage tank (AST) and a 5,000-gallon industrial waste underground storage tank (UST) were decommissioned and removed in 1987. Collectively, the former locations of the two tanks are designated as Site OT029. The results of investigative activities revealed that residual contaminant constituent concentrations in soil and groundwater are below risk-based action levels. Therefore, site OT029 poses no unacceptable risks to human health or the environment. A NFRAP document was generated and no further response actions were required at site closure in March of 1998 (HAFB EMR 1998b). This site is included in the 2003 Five-Year Review for completeness to document the site background.




OU 7 OT029 B-204 BE


No remedial actions are required.


OT029 was not reviewed for 1998 Five-Year Review Report. A decision document for NFRAP was completed in March of 1998.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable


Not applicable. No remedial actions are required.

Question C (Answer)

Not Applicable



VIII. Issues None.




OT029 was recommended for NFRAP status and accepted in 1998 because the site does not pose any unacceptable risks to human health or the environment (HAFB EMR 1998b).






NA

* Not applicable. No RAOs for this site.




OU 7 OT029 B-204 BE






Operable Unit 8

I Introduction

OU 8 is a groundwater-only Operable Unit and contains one site, OT033, the Layton TCE plume (see Table OU 8-1). Chlorinated compounds, primarily TCE comprise the on-Base plume, while both TCE and 1,2-DCA have migrated off Base to the south and southwest. 1,2-DCA is minimally retarded relative to groundwater flow velocities, and has migrated up to 10,000 feet from the source areas off Base. The potential source areas that have impacted groundwater at OU 8 either previously or currently include: the Sodium Hydroxide Tank Site (ST004 in OU 3), the IWTP Sludge Drying Beds (WP006 in OU 3), the former Berman Pond (WP005 in OU 3) and Refueling Vehicle Maintenance Facility (RVMF) (ST018 in OU 3); Building 204 (OT029), Building 220 (ST031 in OU 7) and Building 225 (SS027 & SS032 in OU 7); Pond 1 (SD034 in OU 9); Layton Area; UST sites 260 (ST074) and 280 (ST035); and potentially Buildings 43 and 454 (OT097 in OU 11) (MW 2001). This Operable Unit is currently in the Proposed Plan phase and therefore does not have a final ROD in place. Table OU 8-1. OU 8 Site Identification

Site ID Site Name OT033 LAYTON TCE PLUME

II Site Chronology


III Background

The VOCs most frequently detected above their respective MCLs in OU 8 groundwater include, TCE, 1,2-DCA, 1,1-DCE, 1,1,1-TCA, chlorobenzene, and PCE. In addition, gasoline and diesel range organic compounds and related compounds (benzene, toluene, ethylbenzene, and naphthalene) have been detected in concentrations exceeding their respective MCLs near on-Base UST sites. Inorganic contaminants in groundwater detected above their respective MCLs include hexavalent chromium, nickel, and lead in the vicinity of Building 225 (OU 7) and Hill AFB IWTP (MW 2001). Several remedial actions, corrective measures, and institutional controls have been implemented within the OU 8 area for both groundwater and source areas overlying OU 8. Remedial actions include hydraulic containment of contaminated OU 8 groundwater at the southern Base boundary as a part of an interim remedial action (IRA), implementation of the OU 3 and OU 7 RODs, implementation of interim remedial measures at the Sodium Hydroxide Tank Site (ST004), and implementation of corrective actions at UST sites ST035 (Building 280) and ST074 (Building 260) (MW 2001). Water rights restrictions are in place for all affected areas (HAFB 1998). The areal extent of TCE and 1,2-DCA plumes are shown in Figures OU 8-1 and OU 8-2, respectively. Although these two figures illustrate TCE and 1,2-DCA, other COCs may be present within the boundaries of these plumes. The off-Base TCE plume splits into separate eastern and western legs. Off-Base TCE concentrations are highest in the area extending south


from the OU 8 IRA hydraulic containment system, and the distal portions of both east and west legs. Chemical partitioning calculations estimate the total mass of TCE within the OU 8 plume is approximately 10,500 pounds, with approximately 2,900 pounds in the aqueous phase (i.e., dissolved). The estimated volume of groundwater contaminated with TCE at OU 8 is approximately 4 billion gallons (MW 2001). The 1,2-DCA plume has migrated approximately 3,000 feet past the furthest extent of the off-Base TCE plume. The estimated total mass of 1,2-DCA within the OU 8 plume is approximately 2,800 pounds with approximately 2,100 pounds in the aqueous phase (dissolved). The estimated volume of groundwater contaminated with 1,2-DCA at OU 8 is approximately 2.8 billion gallons (MW 2001). There is chemical and geochemical evidence to suggest that biodegradation of TCE and 1,2-DCA is occurring off Base; however, while TCE concentrations on-Base have attenuated over time there is no evidence to indicate that biodegradation is contributing to this process beneath the industrial area. There is evidence to suggest that dechlorination of 1,1,1-TCA may be occurring on Base. Lead, nickel, and cadmium are readily sorbed to soils or precipitated as carbonates, such that natural attenuation processes may be sufficient to mitigate their transport. Reduction of hexavalent chromium to immobile trivalent forms occurs in subsurface environments and may be sufficient to mitigate its transport (MW 2001). The Remedial Investigation (RI) and the Feasibility Study (FS) for OU 8 were completed in December 2001 and March 2003, respectively. The FS contains both on-Base and off-Base remedial alternatives, however the FS does not outline the preferred remedial alternative for either on- or off-Base sections of the plume. The preferred remedial alternative will be outlined in the Proposed Plan scheduled for general release 18 June 2003. The on-Base alternatives include no further action, limited action, MNA, and two pump and treat options. The off-Base alternatives include no action, limited action, MNA, and three pump and treat options.

IV Remedial Actions

The OU 8 IRA addresses contaminated groundwater along the southern boundary of Hill AFB. The interim remedy selected for OU 8 is designed to prevent further groundwater transport of contamination to off-Base areas, thereby controlling the volume and areal extent of contamination and reducing future potential off-Base risk and cleanup costs. The interim remedy selected for OU 8 was designed to contain the migration of contaminants at the southern boundary of Hill AFB by removing groundwater using a series of vertical extraction wells. Since the objective of the IRA is containment, cleanup levels were not established. The OU 8 IRA hydraulic containment system has been operational since 18 May 1998. Eight extraction wells pump groundwater on a semi-continuous basis discharging to the sanitary sewer for treatment at North Davis County Sewer District (NDCSD). Because the system transects Hillfield Drive adjacent to the south gate of Hill AFB, the conveyance and instrumentation are operated independently as separate East and West systems (see insert on Figure OU 8-1). The East system consists of three extraction wells, and the West system consists of five extraction wells.



No recommendations were made in the 1998 FYR for OU 8. Since 1998 however, the IRA hydraulic containment system continued operation without major changes as the CERCLA process continues. Other progress includes finalization of the RI and the FS for OU 8, which were completed in December 2001 and March 2003, respectively. The Proposed Plan and ROD are scheduled for completion in June and November 2003, respectively.


Question A. Is the remedy functioning as intended by the decision documents? Yes. The principal goal of the IRA is to prevent further groundwater transport of contaminant to off-Base areas, not to restore the contaminated aquifer to drinking water standards (HAFB EMR 1997). Based on potentiometric surface maps, the extraction wells are capturing groundwater in the OU 8 plume at the Base boundary. A final remedy has not been selected and a final ROD has not been implemented at the time of this review. This question should be addressed again following implementation of the final remedy. Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? No. The Utah and Federal Standard for Drinking Water for arsenic at the time the Interim ROD was written was 50 µg/L. This value is currently valid; however, the arsenic standard of 10 µg/L will be effective on 1/26/2006. This decrease should be taken into consideration when writing the final ROD. The Utah and Federal Standard for Drinking Water for hexavalent and total chromium was 50 ug/L at the time the Interim ROD was written. Since an MCL for hexavalent chromium in groundwater is not published, the MCL for total chromium in groundwater is used for both hexavalent and total chromium. The MCL for total chromium in groundwater is 100 µg/L. The value of 100 µg/L for hexavalent and total chromium should be used when the final ROD is written. Question C. Has any other information come to light that could call into question the protectiveness of the remedy? The hydraulic containment system's intent was not protectiveness. Therefore, this question is not applicable.

VIII Issues

1. Table 3-1 of the Interim ROD identifies 10 different contaminants (HAFB EMR 1997). The

RI (MWH 2001) has 5 contaminants detected above their respective MCLs that are not


identified in the Interim ROD. These contaminants are toluene, ethylbenzene, naphthalene, nickel, and lead. Also, arsenic is not mentioned in the RI as a contaminant, but it is listed in the Interim ROD.

2. U8-201, U8-207, and U8-208 (the East system) have had very low TCE concentrations (i.e.,

less than 17 µg/L) since April 1999 and U8-201 has not been above 5 µg/L, the MDL, since April 1999. It may be possible to turn off wells within the East system while still meeting the IRA objective of containing groundwater with contaminant concentrations above MCLs.

3. Calculations in Appendix L of the 2002 O&M Plan (URS 2002), illustrate that U8-203 can be

shut down for a maximum of 38 days while still maintaining (or regaining) capture of the migrating contaminants during the well's shutdown period. This duration was then translated into the maximum allowable system shutdown period. This system shutdown duration may not be appropriate since U8-203 yields substantially more volume than other wells and it is screened in a higher hydraulically conductive zone than other wells in the system.

Further, due to well fouling issues and pump mechanical problems, individual wells within

the IRA system have been inoperable for consecutive months (based on a review of 2 years of monthly and annual reports). No guidance is given in the O&M Plan for the maximum downtime for individual wells within the IRA prior to loss of hydraulic containment (URS 2002).

4. During the interviews with personnel from the O&M contractor, several operational issues

were identified. a. It was reported that some of the pumps in the wells are oversized. Pump sizing in the

current O&M plan is based on projections of modeled flows and from pump tests performed prior to construction. With the exception of U8-203, all projections over estimated actual ground water production rates. Since the flows are less than projected, current pump sizing specified in current version of O&M Plan is in excess of requirements.

b. Spare pumps are operational, but require cleaning and maintenance prior to re-installation.

c. The design and location of the pressure transmitter enclosures allows excessive moisture into the enclosure and inflates operational costs.

5. Air sampling has been performed in a number of homes above the plume. Due to recent

emphasis on vapor intrusion, EMR has worked with the EPA and Utah State to establish an action level for TCE in indoor air at 0.43 ppbv, which may be different than the TCE action level at the time of the OU 8 indoor air testing.

6. A potential exposure pathway, where groundwater comes to the surface in a field drain that

has no institutional controls, was identified in the interview with Rob Petrie of EMR (28 January 2003). The sample identification number for this stream is, U3-633. [A review of the analytical data from this location shows four samples taken between 1993 and 1996. All four samples contained TCE concentrations above the MCL of 5 µg/L. The results ranged from 11-19 µg/L of TCE.] The concentrations at this sampling event were 5 and 6 µg/L for 1,1-DCE and TCE, respectively. Due to the lack of an adequate number of data points, it cannot be determined at this time if this location poses an unacceptable threat to human health.



1. Clarify appropriate COCs in the final ROD. 2. Investigate the following options:

a. Reduce the cost of the sampling program by reducing the frequency of sampling for the East system wells if the change does not significantly impact the accuracy of the mass removal calculation,

b. Reduce the MDL with the laboratory to a reporting limit less than 5 µg/L for better quantification of contaminant concentration to support taking wells off-line,

c. In an effort to reduce system operating costs, take some or all of the East System wells off-line (U8-201, U8-207, U8-208) based on statistically-proven concentrations below MCLs and modeling to ensure that capture of the 5 µg/L contour is not compromised, and

d. Change the discharge point of the East System from the sanitary sewer to the storm drain due to the low concentrations being captured by this section of the system.

3. Calculate maximum shutdown durations for each well within the IRA system to ensure future

capture of the entire plume transect. Compare the maximum well shutdown durations for each well to determine the maximum system shutdown duration.

4. Address operational issues:

a. During the next revision of the O&M Plan, the pump specifications based on predicted flows should be replaced by pump specifications based on actual flows.

b. Clean and maintain spare pumps. c. Complete a cost-benefit analysis for replacement or re-engineering of the current pressure

transmitter enclosures. 5. Re-evaluate previous indoor air data, and if necessary obtain additional air samples to

determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas. If additional indoor air samples are needed, they should be collected during winter months when vapor intrusion will reach its maximum.

6. Review analytical sampling results for U3-633 to quantify exposure risks at this location.

Continue sampling at this location to develop a statistically relevant representation of the exposure risks.


The protectiveness of the remedies at OU 8 cannot be determined or evaluated until a final remedy is selected, implemented, and performance data are reviewed. The FS for this site was finalized in March 2003. A Proposed Plan and a ROD are expected within calendar year 2003.

XI Next Review The next FYR for OU 8 is required by 2008.



(HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1997) Record of Decision for an Interim Remedial Action at Operable Unit 8, Hill AFB EMR, May 1997. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (MWH 2001) Remedial Investigation Report for Operable Unit 8, Montgomery Watson Harza, December 2001. (MWH 2003) Feasibility Study Report for OU 8, Montgomery Watson Harza, March 2003. (URS 2002) Treatment System Operation Report Interim Remedial Action Hydraulic Containment System Operable Unit 8, Hill AFB, Utah, URS, June 2002.



OT033 LAYTON TCE PLUME1993 OU 8 Created OU 8 was created in 1993, and consisted of contaminated

groundwater previously considered part of OU 3 and OU 7.Remedial Investigation Report for Operable Unit 8

05 1997 Interim Record of Decision An interim ROD for an Interim Remedial Action at OU 8 was finalized in May 1997.

Remedial Investigation Report for Operable Unit 8

10 1997 Hydraulic containment system constructed

The hydraulic containment system was constructed from the 20 October 1997 and completed 1 May 1998.

Construction Completion Report for Operable Unit 8 Interim Remedial Action Hydraulic Containment System

1998 Final Inspection of the Interim Remedial Action

Final inspection of the OU 8 IRA Hydraulic Containment System was conducted on 4 May 1998. A final facility inspection by the EPA and UDEQ was conducted on 20 July 1998. O&M system startup was on 18 May 1998.

Final Interim Remedial Action Report for Operable Unit 8

05 1998 The West System was operational Remedial Investigation Report for Operable Unit 8





04 1999 The East System was placed on-line after modifications

The East System was shut down on May 21, 1998 after only four days of operation due to flooding of the electrical pullbox that resulted in electrical component damage. After several design changes were implemented, the East System was restarted in April 1999.

Remedial Investigation Report for Operable Unit 8

12 2001 Remedial Investigation Remedial Investigation finalized. Remedial Investigation Report for Operable Unit 8

03 2003 Feasibility Study Feasibility Study finalized. Feasibility Study Report for OU 8




Operable Unit 9

I Introduction

The eight sites included in OU 9 are listed in Table OU 9-1. The location of each site is shown in Figure OU 9-1. Facilities with deferred action, included in site OT106, are located throughout the Base, and therefore, are not shown on the site map. These facilities are listed in Table OU 9-4. Though these sites are currently investigated and managed under OU 9, they are mostly unrelated to each other in location and in history. There is currently no ROD in place for OU 9. The majority of the OU 9 sites, including Pond 3 (SD023), Pond 7 (SD040), the 1100 Area (SS089), the Zone 7 Golf Course (SS090), and the 800/900 Warehouse Area (SS108), are under remedial investigation for soil and groundwater contamination. The Deferred Areas (OT106) currently include more than 160 facilities with deferred action. Building 786 (SS092) has been designated as a site with no further response action planned. A soil cover, to be constructed May 2003, will be used to contain soil contamination at Pond 1 (SD034). All OU 9 sites have been included for completeness and to document the site background information. The summary of the FYR for each site is shown in Section XIII (OU 9 Site Summaries). Table OU 9-1. OU 9 Site Identification

Site ID Site Name SD023 POND 3 SD034 POND 1 SS092 BLDG 786 OT106 DEFERRED AREAS SD040 POND 7 AREA SS089 1100 AREA SS090 ZONE 7 GOLF COURSE SS108 800/900 WAREHOUSE AREA

II Site Chronology


III Background

Sites included in OU 9 have various and unrelated histories. Refer to individual site summaries, shown in Section XIII, for background information.

IV Remedial Actions

Pond 1 is the only site with a selected remedy. The list of contaminants of concern is presented in the Site Summary (Section XIII) for Pond 1. The soil cover, selected under the EE/CA to contain sediment contamination, is planned for construction in May 2003. See Pond 1 Site Summary (Section XIII) for details of the remedial action. No remedy is required at Building 786, a NFRAP


site. The remaining sites are under remedial investigation and the need for remedial action has not been determined.


Since the 1998 FYR (HAFB EMR 1998a), additional investigation has been conducted at all sites included in OU 9 and site characterization continues under the OU 9 RI/FS effort at most of the sites. A remedy was selected for Pond 1 in 2002 to address contamination in pond sediment. A NFRAP document was also developed for Building 786 in 2002.


A review for all sites, except the Deferred Areas (OT106), was conducted per the process described for the overall 2003 FYR. Because site characterization has been deferred for OT106 facilities and protectiveness cannot be evaluated, this site was not reviewed. A list of the deferred facilities, shown in Table OU 9-4, has been included in this report for completeness.


Results of the technical assessment for each site in OU 9 are listed in Table OU 9-3. A technical assessment for the OU as a whole is not provided because the sites are unrelated. Details of the technical assessment for each site in OU 9 are provided in the respective site summary (see Section XIII).




Next Five-Year

Review SD023 Not determined NA NA NA NA 2008

SD034 Soil cover Yes Yes No Protective once

remedy is completed

2008

SS092 Not required, NFRAP site NA NA No Protective Not required

OT106 Not determined NA NA NA NA 2008

SD040 Not determined NA NA NA NA 2008

SS089 Not determined NA NA NA NA 2008



OU9 Soil cover NA NA NA Protective once

remedy is completed

2008





VIII Issues

Based on the information reviewed, no issues have been identified that may affect protectiveness of the selected remedy (soil cover at Pond 1) at OU 9. The majority of the sites are still under remedial investigation. However, institutional controls are in place and there is no immediate threat to human health.

IX Recommendations and Follow-up Actions for OU 9 The recommendations and follow-up actions for OU 9 are:

1. Construct soil cover at Pond 1 as scheduled in May 2003. 2. Complete remedial investigation and present results in RI report as scheduled in 2004. 3. Continue institutional controls at sites under RI to limit human exposure to potential

contamination. 4. Continue annual inventory of deferred facilities to determine when site characterization can

be conducted. X Protectiveness Statement for OU 9

The remedy for site SD034 at OU 9 will be protective of human health and the environment once it is completed. Institutional controls have been implemented at all deferred sites under remedial investigation to limit human exposure to potential contamination until the need for remedial action can be determined.

XI Next Review

The next FYR for OU 9 is required by 2008. No future review is required for Building 786 (SS092) because no further remedial action is planned for this site.


(CH2M 2002a) Engineering Evaluation/Cost Analysis for the OU9 Pond 1 Removal Action, Final Report, CH2M Hill, April 2002. (CH2M 2002b) Building 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report, CH2M Hill, September 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1995) Record of Decision for Operable Unit 3, Hill AFB, September 1995. (HAFB EMR 1998a) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998.


(HAFB EMR 1998b) Decision Document for IRP Site SD40A Category III NFRAP Pond 6, Hill AFB EMR, March 1998. (MW 2000) Final Data Summary Report and Preliminary Conceptual Model for Operable Unit 9 Investigation Areas, Montgomery Watson, October 2000.

Table OU 9-4. OU 9 Site OT106 Deferred Sites Source: Hill Air Force Base Calendar Year 2001 Deferred Site Inventory Report

Building Number Facility Use Site Status

1 / 1A Maintenance Hangar and Annex Defer action

5 Office and Shop Area Defer action

25 Three Aircraft Maintenance Hangars Defer action

30 Metal Shop Defer action

37 General Aircraft Maintenance Hangar Defer action

39 Aircraft Maintenance Shops / Supply Storage Defer action



43 Fuel Systems Maintenance Hangar Defer action



48 Corrosion Control Facility Defer action

49 Fueling Station Defer action

55 Storage Defer action

100 Lab / Office Space Defer action

202 Flight-Line Vehicle Maintenance Facility Defer action

205 Former Landing Gear Repair Shop - Currently Electrical Circuit Plating Shop / Component Repair Facility

Defer action

206 Indoor C-130 Wash Rack Defer action

214 Precision Maintenance and Evaluation Laboratory Defer action

220 Main Painting Hangar Defer action

Table OU 9-4. OU 9 Site OT106 Deferred Sites (Cont.)



225 Main Maintenance Hangar Defer action

227/228 Defueling Hangars Defer action

233 Final Flight Test Hangar Defer action

236 Fuel System Maintenance Facility Defer action

238 F-16 and C-130 component repair Defer action

256 Chemical Distribution Area Defer action

257 Plastics Repair - Fabrication Facility / Compressed Gas Cylinder Testing Shop Defer action

260 Steam Heating Plant Defer action

265 Shop Facility Defer action

270 C-130 Paint Hangar Defer action

279 Aircraft Engine Storage Area Defer action

287/15090 Aircraft Fuel Purge and Outside Maintenance Area Defer action

295 Office Space / Aircraft Hangar Defer action

505 Plating and Grinding Shop Defer action

507 Landing Gear Repair Facility Defer action

509 Weapons System Repair Facility / Fuel Tank Calibration Lab Defer action

510 Machine Shop Defer action

511 IWCS connection Defer action

515 Small Vehicle Maintenance Shop Defer action

575 Industrial Wastewater Treatment Plant Defer action

576 F-16 Fuel System Repair / Repair of External Fuel Tanks Defer action

589 Aircraft Engine Inspection / Maintenance Shop Defer action

590 Repair / Maintenance Hangar Defer action

592 Locker Room / Flight-Line Vehicle Maintenance Facility Defer action

597 Clean Labs / Aircraft Component Repair Shops Defer action

732 Small Arms Facility Defer action




741 Small Arms Marksmanship Training Unit Building Defer action

752 Weapon Depot Shop Defer action

776 Storage Shed Defer action

786 Pesticide and Herbicide Storage Site Investigation completed in 2002. Results pending.

787 Test Equipment Storage Site Investigation completed in 2002. Results pending.

800 Current Use - Warehouse and Office Space Building planned for demolition in 2009

847 Missile Transportation Vehicle Maintenance Defer action

893/896/897 DRMO Storage Sheds Defer action

911 Fuel Truck Repair / Above Ground Fuel Tank Storage Defer action

916 Paint Service Magazine Site Investigation to be completed in 2003

918 Waste Oil Storage / Liquid Oxygen and Nitrogen Storage and Distribution

Site Investigation to be completed in 2003

924 IWCS Lift Station 1 Defer action

935 Maintenance / Inspection Building Defer action

940 Missile Disassembly / Assembly Building Defer action

960 Maintenance Defer action

965 Missile Assembly Shop Defer action




983 Rocket Check Assembly Storage Defer action

1011 Black Powder Rest House Site Investigation completed in 2002. Results pending.

1012 Precious Element Service Magazine Site Investigation completed in 2002. Results pending.

1021 Paint and Oil Service Building Site Investigation completed in 2002. Results pending.

1023 Paint and Oil Service Building Site Investigation completed in 2002. Results pending.

1112 Fuel Oil Tank Site Investigation to be completed in 2003

1116 Incinerator Site Investigation to be completed in 2003




1117 Ordnance Depot Septic Tank Site Investigation completed in 2002. Results pending.

1132 Locomotive Shelter Defer action

1133 Vehicle Maintenance Shop Defer action

1135 Utilities Shop Building Defer action

1140 Former Janitor’s Office Site Investigation completed in 2002. Results pending.

1141 Garage/Storage Defer action

1202 Software Control Center Defer action

1203 Engineering Test Facility Defer action


1248 Material Process Depot Defer action


1258 Administrative Building Defer action

1264 Integrated Support Facility Defer action

1267 Photographic Laboratory Defer action

1289 Administrative Building Defer action

1312 Base Maintenance Shop Site Investigation completed in 2002. Results pending.

1377 Munitions Processing Facility Defer action

1422 Material Process Depot Defer action

1424 Missile Assembly Shop Building planned for demolition in 2008

1503 Asbestos Abatement Building and Transformer Pad Site Investigation completed in 2002. Results pending.

1504 Boiler House Site Investigation completed in 2002. Results pending.

1521 Explosive Storage Site Investigation completed in 2002. Results pending.

1522 Boiler House Site Investigation completed in 2002. Results pending.

1524 Acid Storage Shed Site Investigation to be completed in 2003

1528 Hazardous Storage Shed Site Investigation completed in 2002. Results pending.

1534 TNT Box Opening Building Site Investigation completed in 2002. Results pending.




1538 Air Force Plant 77 storage shed Site Investigation completed in 2002. Results pending.

1539 Wash House Site Investigation completed in 2002. Results pending.




1548 Boiler / Heating Plant Site Investigation completed in 2002. Results pending.

1566 Tactical Missile G/W Shop Defer action

1590 Heating Facility Building Defer action

1600 Test Facility Site Investigation to be completed in 2003

1606 Munitions Storage Site Investigation completed in 2002. Results pending.

1643 Flammable Material Storage Building Site Investigation to be completed in 2003

1644 Fuse Test Building Site Investigation completed in 2002. Results pending.

1649 Missile Test Facility Defer action

1653 Tetryl Screening and Blending Site Investigation completed in 2002. Results pending.

1654 Tetryl Screening and Blending Site Investigation completed in 2002. Results pending.

1655 Tetryl Service Magazine Site Investigation completed in 2002. Results pending.

1833 PBPS Surveillance Facility Defer action

1907 Vehicle Storage Wash Building Site Investigation completed in 2002. Results pending.

1913 Pneudraulic Shop Building planned for demolition in 2006

1917 ICBM Dir / Propellant Analysis Building planned for demolition in 2006

1919 Museum BLDG / MMIT Simulator Repair Defer action

1931 Missile Service Shop Defer action

1934 Storage Building Site Investigation completed in 2002. Results pending.

1936 Wash Rack Defer action

1937 Hazardous Storage Depot Site Investigation completed in 2002. Results pending.

1939 Missile Service Shop Site Investigation completed in 2002. Results pending.




1948 Quality Control Lab Building planned for demolition in 2007

1950 Propellant Packaging Facility Building planned for demolition in 2007

1952 Propellant Packaging Facility Building planned for demolition in 2007

2001 Hazard Storage Depot Site Investigation completed in 2002. Results pending.

2002 Nitric Acid Storage Site Investigation completed in 2002. Results pending.

2007 Instrument Overhaul Site Investigation completed in 2002. Results pending.

2008 Compass Repair Site Investigation completed in 2002. Results pending.

2015 Primer Rest House Site Investigation completed in 2002. Results pending.

2016 Transformer Pad Site Investigation to be completed in 2003

2112 Munitions Storage Site Investigation to be completed in 2003

2114 Missile Service Shop Site Investigation to be completed in 2003

2122 Storage Magazine / Paint Services Site Investigation completed in 2002. Results pending.

2133 Tetryl Pellet Rest House Site Investigation completed in 2002. Results pending.

2137 Primer Magazine Site Investigation completed in 2002. Results pending.




2149 Missile Service Shop Site Investigation to be completed in 2003

2201 Storage Building Building planned for demolition in 2004

2202 Missile Service Storage Building Site Investigation completed in 2002. Results pending.

2214 Conventional Munitions Shop Defer action

2310 Magazine Storage and Pellet Rest House Site Investigation completed in 2002. Results pending.

2314 Magazine Storage and Black Powder Screen and Blend Site Investigation completed in 2002. Results pending.

2317 Magazine Storage and Black Powder Storage Site Investigation completed in 2002. Results pending.






2335 Magazine Storage and Black Powder Screen and Blend Site Investigation completed in 2002. Results pending.

2338 Magazine Storage and Black Powder Storage Site Investigation completed in 2002. Results pending.

2401 Guided Missile Production Facility Defer action

2402 Guided Missile Production Facility Site Investigation to be completed in 2003





2410 Utility Vault Site Investigation completed in 2002. Results pending.

11420 Underground Transformer Vault Defer action

11647 Missile Test Facility Defer action

OB/OD Range Open Burn / Open Detonation Defer action

SW outfall in Zone 1500 Storm Sewer Outlet (Zone 1500) Site Investigation to be completed in

2003



SD023 POND 31989 RI/FS process for Pond 3 was

initiatedEvaluate the presence/absence of contaminants in pond surface water and sediment.


04 1992 Remedial Investigation OU 3, Phase I. Site characterization at Pond 3

Investigation to evaluate the nature and extent of surface water and sediment contamination. Surface water and pond sediments sampled.


03 1995 Remedial Investigation OU 3, Phase II. Site characterization at Pond 3



09 1995 Record of Decision for OU 3, include Pond 3

Based on OU 3 RI/FS and Risk assessments, contaminants in Pond 3 surface water and sediment do not pose current or future health risk or present a threat to groundwater. Therefore, cleanup actions area not necessary at Pond 3.


09 1999 Detailed topographic survey of Pond 3

EMR voluntarily initiated additional investigation at Pond 3 when contamination was detected on Pond 1 inlet. The survey included a fly over on Sep 8, 1999 by Olympus Aerial Survey of Salt Lake City and depth measurement of Pond 3. Investigation reopened under OU 9.






10 2000 Remedial Investigation - soil samples collected at Pond 3

Investigation included hand augured soil borings at 10 locations. Each were driven to a depth ranging from 3 to 4 ft. Soil samples were collected beneath the surface of the water and were sampled for VOCs, SVOCs and trace metals. Investigation was to provide information on the horizontal and vertical extent of potentially contaminated sediment. Findings will be summarized in a future conceptual site model report. (Completion of the RI is planned for 2004.)


SD034 POND 11940 1940 -1944 Pond 1 received

discharge from Berman Pond during times of overflow from high intensity storms

Berman Pond operated as an unlined evaporation pond from 1940 to 1956 and received storm-water runoff and industrial wastewater, which includes spent solvents, metals, and hydrocarbons.


1956 Pond 1 was disconnected from Berman Pond

Berman Pond was connected to a sewer line leading to the IWTP in 1956.


09 1988 RI/FS process for Pond 1 was initiated

Investigation to evaluate the presence/absence of contaminants in pond surface water and sediment.


04 1992 Remedial Investigation OU 3, Phase I. Site characterization at Pond 1







03 1995 Remedial Investigation OU 3, Phase II. Site characterization at Pond 1



09 1995 Record of Decision for OU 3, including Pond 1

Based on OU 3 RI/FS and Risk assessments, contaminants in Pond 1 surface water and sediment do not pose current or future health risk or present a threat to groundwater. Therefore, cleanup actions are not necessary at Pond 1.


01 1997 Samples collected in northeast corner of Pond 1 near the inlet

Samples collected near Pond 1 inlet to investigate potential contamination of pond sediments as a result of contamination detected in the storm water system at Berman Pond. RBSLs were exceeded for arsenic, beryllium, PCBs, chlorobenzene, and dichlorobenzene. Investigation performed under OU 9.


08 1999 Detailed topographic survey Crew measured approx. 925 locations for vertical and horizontal control. Objective of the survey was to provide enough data to create an accurate contour map of the pond area.


09 1999 Phase I Pond 1 investigation Investigation included direct-push borings and hand auger borings . 50 soil samples were collected and analyzed for VOCs, SVOCs, PCBs, pesticides, and TVPH, TEPH, hexavalent chromium, and trace metals. Industrial RBSLs were not exceeded. Residential RBSLs were exceeded for trace metals, PCB, and SVOCs.






08 2000 Sediment samples collected at Pond 1

Investigation included direct-push soil borings at 29 locations. Each were driven to a depth ranging from 4 to 12 ft. 40 soil samples were collected from various depths throughout the pond footprint and analyzed for VOCs, SVOCs, PCBs, petroleum hydrocarbons (PHC), and trace metals. Sediment samples were found to exceed both residential and industrial RBSLs for PHC, cadmium, and mercury


2001 Soil sample collected in the drainage channel and in the pond

7 hand auger borings were excavated to a depth of 6 to 10 ft bgs. The borings were located in the drainage channel between the flight line storm drain outlet east of Pond 1 and the pond basin. The samples were analyzed for VOCs, SVOCs, metals, and TPH. Residential RBSLs were not exceeded.


04 2002 Engineering Evaluation / Cost Analysis

4 areas of contaminated pond sediments found. EE/CA recommends excavation of pond sediments that exceed residential RBSLs in two areas, combine these sediments with the other two areas, and place an 8-ft soil cover on top. Also included pond expansion. After construction and implementation of the recommended institutional controls, the soil cover is expected to be protective of human health and the environment. The 8 ft soil cover will limit the exposure pathway for any future residential and industrial tenant on the facility. The soil cover also reduces the potential mobility of the contaminants. However, the toxicity and volume of the contaminants remain unchanged. (Construction is scheduled for May 2003)






SS092 BUILDING 7861984 1984 - 1997 Building was used as a

pesticide/herbicide storage buildingBuilding 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report

06 1996 Site Inspection Samples were collected during the OU 9 North Area Site Inspection. Pesticides were detected above residential RBSLs in one soil sample.

Building 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report

1997 Building was demolished Building 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report

04 2000 Remedial Investigation Two soil borings were drilled to 16 ft bgs. Groundwater was not encountered. Pesticides and herbicides were not detected at or above residential RBSLs.


06 2000 Remedial Investigation Surface soil samples were collected at 8 locations from 0-6 inches. Pesticides were not detected at or above residential RBSLs.






09 2002 EPA concured with NFRAP September 4, 2002 Building 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report

09 2002 NFRAP Decision Document developed


OT106 DEFERRED AREAS04 1994 Preliminary Assessment - South

AreaFinal South Area Of Operable Unit 9 Site Inspection, Final Comprehensive Data Evaluation, Volume 1

06 1995 Preliminary Assessment - North Area

North Area Preliminary Assessment Report, June 1995, Final

07 2000 Site Inspection - North Area Facilities were categorized based on level of contamination found, threat to human health, accessibility for sampling (deferred action), environmental management programs.






02 2001 Site Inspection - South Area Facilities were categorized based on level of contamination found, threat to human health, accessibility for sampling (deferred action), environmental management programs.


2002 Site Investigation - Phase I Phase I conducted in summer 2002 at 50 facilities. Results pending. Once results are published for a site, the site will be removed from OT106 deferred list.


03 2002 Site Management Plan for OU 9 Deferred Sites

Provides mechanism to track and inventory deferred sites. Operable Unit 9 Calendar Year 2001 Deferred Sites Inventory Report, Hill Air Force Base, Utah. Draft

SD040 POND 7 AREA1976 Construction of Pond 7 Designed to store runoff from the southwest side of Hill AFB. Decision Document for IRP Site SD40A Category III

NFRAP Pond 6

09 1993 Preliminary Assessment / Site Inspection at Pond 7

Surface soil, pond sediments, groundwater, and surface water were investigated. Detected organics levels were below the residential RBSLs. Metals were observed at only slightly higher concentrations than established background concentrations.

Final South Area Of Operable Unit 9 Site Inspection, Final Comprehensive Data Evaluation, Volume 1





03 1998 NFRAP developed for Pond 7 (aka Pond 6)

Pond 7 was incorrectly identified as Pond 6 in the Decision Document.

Decision Document for IRP Site SD40A Category III NFRAP Pond 6

1999 Groundwater contamination was detected downgradient of Pond 7 Area during the basewide CPT investigation

Part of basewide CPT investigation. TCE detected from 22 - 55 ft bgs and maximum TCE conc. detected was 150 ug/L. Other VOCs detected were all below their respective MCLs.


07 2000 Site Inspection - North Area Potential groundwater contamination originated from Pond 7 area. Additional investigation was recommended.

Final South Area Of Operable Unit 9 Site Inspection, Final Comprehensive Data Evaluation, Volume 1

10 2000 Remedial Investigation - physical and analytical data collection at the Pond 7 Area

Investigation includes CPT investigation, groundwater sampling, installation of 5 CPT piezometers and 4 monitoring wells, and groundwater elevation measurements. Findings will be summarized in a future Conceptual Site Model (CSM) report.


01 2002 Remedial Investigation - physical and analytical data collection at the Pond 7 Area

Groundwater mapping, CPT investigation, groundwater sampling, and groundwater elevation measurements. Data will be evaluated in the RI report (planned for 2004).






SS089 1100 AREA03 1998 Site Inspection - OU 9 North

Area - includes the West Gate areaField data was collected between Dec 1995 and Mar 1998 for various OU 9 investigation sites.


04 2000 Remedial Investigation - included the West Gate area

Field data was collected between April 1998 and April 2000 for various OU 9 investigation sites.


10 2000 Remedial Investigation -physical and analytical data collection at the 1100 Area

Investigation included CPT and direct-push groundwater sampling, installation of 11 new monitoring wells (U9-11-008 through U9-11-018) ranging from 32-42 ft bgs, and in-situ permeability tests (slug tests) at the new wells. Findings will be summarized in a future Conceptual Site Model (CSM) report.


10 2000 Preliminary conceptual site models were developed for the West Gate area

Based on data collected during the North Area Site Inspection (1995 to 1998) and between 1998 and 2000, during the ongoing RI/FS investigation of OU 9. Sources of the groundwater contamination plume are unknown since the soil investigations have not been conclusive.


01 2002 Remedial Investigation - physical and analytical data collection at the 1100 Area

Investigation performed at on and off-Base locations and included groundwater mapping, CPT investigation, groundwater sampling, and groundwater elevation measurements. Data will be evaluated in the RI report (planned for 2004).






SS090 ZONE 7 GOLF COURSE03 1998 Site Inspection - OU 9 North Area Field data was collected between Dec 1995 and Mar 1998 for

various OU 9 investigation sites.Final Data Summary Report and Preliminary Conceptual Model for Operable Unit 9 Investigation Areas

04 2000 Remedial Investigation - included the Golf Course Area

Field data was collected between Apr 1998 and April 2000 for various OU 9 investigation sites.


10 2000 Remedial Investigation -physical and analytical data collection at the Golf Course

Investigation was performed as part of the ongoing RI/FS investigation at OU 9. Investigation included CPT and direct-push groundwater sampling to define the nature and extent of groundwater contamination. Groundwater samples were analyzed for VOCs. Five new monitoring wells (U9-07-007 through U9-011) were installed in the Golf Course area with depths ranging from 40 to 51.5 ft. Groundwater was sampled at one of the new wells and 6 previously established wells. Groundwater sampled from the monitoring wells was analyzed for VOCs, cations, sulfide, anions, alkalinity, total dissolved solids (TDS), total organic carbon (TOC), and field parameters. Soil from the screened intervals was also sampled. Groundwater elevation measurements were taken in 11 monitoring wells and 12 piezometer locations throughout the study area. Findings will be summarized in a future Conceptual Site Model (CSM) report.






10 2000 Preliminary conceptual site models were developed for the Golf Course

Based on data collected during the North Area Site Inspection (1995 to 1998) and between 1998 and 2000, during the ongoing RI/FS investigation of OU 9. Building 710, the maintenance shop, is the likely source of the groundwater contamination.


2001 Remedial Investigation - source of contamination identified

Building 710 (golf course maintenance shop) was identified as the primary source of contamination in the area. TCE and PCE were detected above their respective MCLs in groundwater with CPT and monitoring well samples.

OU11 Remedial Investigation/Feasibility Study, Operable Unit 11 Analytical Data Report, May 1 2001 - January 31 2002

01 2002 Remedial Investigation - physical and analytical data collection at the Golf Course Area to further delineate the plume boundaries

Phase I investigation to further delineate the extent of the horizontal and vertical plume boundaries. Investigation included groundwater mapping, CPT investigation, groundwater sampling, and groundwater elevation measurements. Data will be evaluated in the RI report.

OU11 Remedial Investigation/Feasibility Study, Operable Unit 11 Analytical Data Report, May 1 2001 - January 31 2002

10 2002 Management of the Zone 7 Golf Course was transferred from OU 11 to OU 9

The OU 9 RI report is planned for 2004. FYR Site List

SS108 800/900 WAREHOUSE AREA 12 1993 Basewide Underground Storage

Tank (UST) Program (Building 914)

Free product detected at 30 ft bgs near Building 914 and is being investigated as part of the basewide UST Program. Draft Final Subsurface Investigation Report for UST Sites 780 (ST77), 859 (ST84; EGTD), 914 (ST71; EHVC), and 1243 (ST57), December 1993.

Proposed 1st Round Cone Penetration Testing Locations for the 800 / 900 Area, Operable Unit 11





2001 Management of the 800/900 Warehouse Area was transferred from OU 8 to OU 11

In fall of 2001 OU11 Remedial Investigation/Feasibility Study, Operable Unit 11 Analytical Data Report, May 1 2001 - January 31 2002

02 2001 Site Inspection - South Area SI performed near the 800/900 Warehouse Area Proposed 1st Round Cone Penetration Testing Locations for the 800 / 900 Area, Operable Unit 11

12 2001 Remedial Investigation - OU 8 During the RI, chlorinated solvents were detected above their respective MCLs in the groundwater at 150-165 ft bgs at monitoring well U8-091. RI concluded that the contamination at U8-091 was not hydraulically connected with the OU8 plume.


01 2002 Basewide CPT Investigation TCE detected above its MCL at 74 ft bgs (U9-BW-639) and at 91 ft bgs (U9-BW-644). Free product detected near Building 914 is being investigated as part of the basewide UST Program.


10 2002 Management of the 800/900 Warehouse Area was transferred from OU 11 to OU 9

Additional investigation planned under OU 9. The OU 9 RI report is planned for 2004.

FYR Site List




OU 9 SD023 POND 3


III. Background Pond 3 is located in the southern portion of the Base, and has been used as a storm water retention pond since 1957. Pond 3 is also designed as a wildlife habitat area. Surface water runoff from the southern end of the Base, including a portion of the industrial area and aviation ramp areas, is collected by a storm sewer system which discharges to Pond 3. Surface water runoff collected in Pond 1 also drains into Pond 3. Water in Pond 3 drains to the south and eventually discharges to Kay's Creek located southeast of the Base. Pond 3 was investigated during the OU 3 Remedial Investigation in 1992, but no significant contamination was detected and the site was designated as a NFRAP site under the OU 3 ROD (HAFB EMR 1995). However, as a result of the detection of contamination around the inlet to Pond 1, additional investigation of Pond 3 inlet was initiated voluntarily by EMR in 1999. Further soil investigation is being performed at Pond 3 as part of the ongoing OU 9 RI/FS effort. The estimated completion date for the OU 9 RI is April 2004 and the estimated completion date for the OU 9 ROD is June 2005.

The National Pollutant Discharge Elimination System (NPDES) permit currently does not require discharge sampling at Pond 3. The groundwater under Pond 3 was investigated as part of OU 3 and no evidence of groundwater contamination was found, so monitoring is not warranted.


The need for remedial action has not been determined. The site is under remedial investigation.


Pond 3 was designated as a NFRAP site at the time of the 1998 Five-Year Review (HAFB EMR 1998a). Since then, the site has been reopened for further investigation and is part of the ongoing OU 9 RI/FS effort. In 1999, a detailed topographical survey was performed, which included aerial survey and pond depth measurements. Pond sediment was sampled in 2000 to characterize the horizontal and vertical extent of potential soil contamination.


I. Introduction Pond 3 is a storm water retention pond under remedial investigation for soil contamination. This site is a former NFRAP site under the OU 3 ROD, but has been reopened for additional investigation under OU 9. The need for remedial action has not been determined. This site is included in the 2003 Five-Year Review for completeness to document the site background and the status of the remedial investigation.



NA NA - Remedial Investigation and Risk Assessment have not been completed; therefore, no CoCs are defined to date.

NA





OU 9 SD023 POND 3

Evaluation of the data has not been published, but findings will be summarized in the OU 9 RI report scheduled in 2004.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable

Question B (Comment) The need for remedial action has not been determined. The site is under remedial

investigation.

Question C (Answer)

Not Applicable



VIII. Issues Extent of soil contamination has not been defined.

IX. Recommendations * Continue remedial investigation to identify the extent of the soil contamination at Pond 3. * Continue institutional controls to limit human exposure to potential contamination.



SD023 is under remedial investigation and the need for remedial action has not been determined. However, institutional controls have been implemented to prevent human exposure to potential contamination. The site is included in the Continuing Order AFI 32-7020 (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater. In addition, the Utah Division of Water Rights also restricts water well drilling and use of shallow groundwater in this area. A sign has been posted to restrict swimming in the pond.





OU 9 SD023 POND 3


2008




OU 9 SD034 POND 1


III. Background Pond 1 is located along the southern boundary of Hill AFB, east of the South Gate and southeast of Berman Pond. From 1940 to 1956, Pond 1 received overflow from Berman Pond, which operated as an evaporation pond and received storm water runoff and industrial wastewater containing spent solvents, metals, and hydrocarbons from shop operations and spills in the industrial area. The storm drain system operated as the industrial sewer until the construction of the IWTP in 1956 when the drain system was routed directly to Pond 1. During storm events, storm water from the industrial area and the flight line flows into Pond 1. After the storm event, the water is released via an underground storm drain to Pond 3. The water from Pond 3 is released to the city of Layton storm drain system, which discharges into Kays Creek, and eventually flows into the Great Salt Lake. The NPDES permit currently does not require discharge sampling at Pond 1.

A series of investigations at Pond 1 were carried out from the early 1990s to 2001. Pond 1 surface water and sediments were sampled in the early 1990s as part of the OU 3 remedial investigation. Results of the OU 3 RI indicated that contamination was not above risk -based levels, and the Final Record of Decision for Operable Unit 3 did not require any remedial activities at Pond 1(HAFB EMR 1995). Discovery of a large volume of contaminated sediments from the industrial complex storm drain system resulted in additional investigation at Pond 1 between 1997 and 2001. Four areas of soil contamination, with levels above residential risk-based screening levels, were identified. The contamination found in the Pond 1 sediments may have been deposited during the 1940s through the early 1960s when the storm drain system was used as the industrial sewer. The principal contaminants in sediments at Pond 1 are fuel-related hydrocarbons, metals, PAHs, and PCBs. The majority of the highly contaminated locations are concentrated near the northwest inlet of the pond, where the influent enters Pond 1.


I. Introduction Pond 1 is used as a storm water overflow storage pond, and the water in Pond 1 is drained to Pond 3 as soon as possible after a storm. Soil contamination includes fuel-related hydrocarbons, metals, polyaromatic hydrocarbons (PAHs), and PCBs. The selected remedy, a soil cover of the contaminated sediment, is scheduled for construction in May 2003.


SOIL 1,4-DICHLOROBENZENE 10483.22 ppm

SOIL ARSENIC 9.76 ppm

SOIL BENZO(a)ANTHRACENE 877.16 ppm

SOIL BENZO(a)PYRENE 87.72 ppm

SOIL BENZO(g,h,i)PERYLENE 877.17 ppm




OU 9 SD034 POND 1


Pond sediment - Soil cover

The selected remedy is described in the EE/CA for Pond 1 (CH2M 2002a). Four areas of Pond 1 have been identified to contain sediment with contaminant levels exceeding residential risk-based screening levels. Contaminated sediment at the two eastern areas will be excavated and distributed over the contaminated sediment located at the two western areas. An 8-ft soil cover will be constructed at the western portion of the pond, over all the contaminated pond sediment that will be stockpiled there. Construction of the soil cover would decrease the pond capacity. To maintain pond capacity, the south area of the pond will be excavated to expand the pond. The excavated soil from the pond expansion will be used as the fill material for the soil cover and as backfill for the excavated contaminated sediment. To limit storm water saturation of the soil cover, the pond will be graded to drain to a new outlet located at the southwest corner of the pond. Construction of the remedial action is scheduled to begin May 2003.

Institutional controls will be required to ensure the future integrity of the soil cover. Groundwater under Pond 1 is monitored as part of OU 8. The site is included in the Continuing Order (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater. In addition, the Utah Division of Water Rights also restricts water well drilling and use of shallow groundwater in


SOIL BENZO(k)FLUORANTHENE 8770.21 ppm

SOIL BENZOFLUORANTHENE ISOMER 877.09 ppm

SOIL BERYLLIUM 0.67 ppm

SOIL bis(2-ETHYLHEXYL) PHTHALATE 45644.57 ppm

SOIL CADMIUM 3.58 ppm

SOIL CHROMIUM, HEXAVALENT 504.61 ppm

SOIL DIBENZ (a,b) ANTHRACENE 87.72 ppm

SOIL INDENO(1,2,3-c,d)PYRENE 877.17 ppm

SOIL LEAD 400 ppm

SOIL MERCURY 0.65 ppm

SOIL PCB-1248 (AROCHLOR 1248) 5436.63 ppm

SOIL PHC as DIESEL FUEL 344.86 ppm

* Minimize the threat of human and environmental exposure to contaminated pond sediments.




OU 9 SD034 POND 1

this area.


Pond 1 was not reviewed for 1998 Five-Year Review (HAFB EMR 1998a) because this site was designated as a NFRAP site at that time. Since the 1998 Five-Year Review, additional investigations have been performed at Pond 1 and a remedy has been selected. Soil sampling of pond sediments and surrounding areas was conducted in 1997, 1999, 2000, and 2001. A detailed topographical survey of Pond 1 was conducted in 1999. The EE/CA for Pond 1 was developed in 2002 to document the selected remedy.


Question A (Answer)

Yes


After construction and implementation of the recommended institutional controls, the soil cover is expected to be protective of human health and the environment. The 8-ft soil cover will limit the exposure pathway for any future residential and industrial tenant on the facility. Since the contaminants will not be removed, the toxicity and volume of the contaminants will remain the same, but the soil cover will reduce the potential mobility of the contaminants.

Question B (Answer)

Yes


Risk assessment analysis was performed in 2002 as part of the EE/CA for Pond 1 (CH2M 2002a). Exposure assumptions, toxicity data, cleanup levels, and remedial action objectives are still valid.

Question C (Answer)

No


No information has surfaced that call into question the protectiveness of the remedy.

VIII. Issues No issues have been identified during the review.

IX. Recommendations * Construct soil cover as scheduled in May 2003.* Implement institutional controls to ensure the future integrity of the soil cover.

X. Protectiveness Will be protective once remedy is completed





OU 9 SD034 POND 1


2008


The remedy associated with SD034 will be protective of human health and the environment once the soil cover is constructed and institutional controls are implemented.




OU 9 SS092 BUILDING 786


III. Background Building 786 was located along the eastern boundary of the Base near the north end of the runway. From 1984 to 1997, the building was used for pesticide / herbicide storage. In 1997, the building was demolished. The site is expected to remain available for industrial use in the foreseeable future. The proximity to the runway prohibits the potential for residential use as Base housing. Soil in the vicinity of Building 786 was investigated during three sampling events between 1996 and 2000. Pesticides were not detected at or above residential risk-based screening levels except for one sample collected in 1996. No further remedial action is required at this site (CH2M 2002b).


The data available to date indicate that the Building 786 site does not pose a threat to human health or the environment. No further response action was recommended and approved by EPA Region VIII for the Building 786 site (CH2M 2002b).


Since the 1998 Five-Year Review (HAFB EMR 1998), two additional soil sampling events were conducted in 2000. Pesticides and herbicides were not detected at or above residential risk-based screening levels (RBSLs) during those investigations.


Question A (Answer)

Not Applicable


No remedy was required.



I. Introduction Building 786 was a pesticide / herbicide storage area and has been demolished. Sampling results indicate the site does not pose a threat to human health or the environment. Therefore, no remedial action is required (CH2M 2002b). This site is included in the 2003 Five-Year Review for completeness to document the site background.




NA





OU 9 SS092 BUILDING 786



Question B (Answer)

Not Applicable



Question C (Answer)

No



VIII. Issues No issues have been identified during the review.

IX. Recommendations * No further action is required at this site. It will not require future Five-Year Reviews.



SS092 was recommended for NFRAP status and accepted in 2002 because investigations indicate that this site does not pose a threat to human health and the environment (CH2M 2002b).




OU 9 OT106 DEFERRED AREAS


III. Background The deferred sites include facilities and areas that pose low risk to human health based on existing land use and lack of an exposure route. Complete site characterization of these sites has been deferred because preliminary sampling results indicate contaminant concentrations were below the risk-based screening levels for the current land use or sampling cannot be performed without disturbing facility operations. Investigations at these sites are deferred until access can be gained for sampling or until land use changes from industrial to residential. The deferred sites are inventoried annually until they can be further characterized. Once a site characterization is completed, the site will be either be removed from the inventory list, if the concentrations of the detected contaminants are below the risk-based screening levels, or further investigated under a new site ID. The description and status of the deferred facilities are provided in a separate listing (see Table OU 9-4).


The need for remedial action has not been determined. Site characterization has been deferred.


This site was not reviewed for the 1998 Five-Year Review (HAFB EMR 1998a). In 2002, site investigation was initiated at 50 facilities and results will be published in 2003.

VI. FYR Process Since action has been deferred for facilities included in this site, a list of deferred facilities has been included in the 2003 Five-Year Review in a separate table (see Table OU 9-4) for completeness.



I. Introduction This site currently includes more than 160 facilities, located throughout Hill AFB, with deferred action. Deferred facilities are inventoried annually to determine when site characterization can be conducted. Once site characterization has been initiated, the facility will be removed from site OT106, and future management of the facility will depend on the result of the investigation. This site is included in the 2003 Five-Year Review for completeness to document the site background and the site management plan.




NA





OU 9 OT106 DEFERRED AREAS


2008

Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable



Question C (Answer)

Not Applicable



VIII. Issues No issues were identified during the review. Site characterization has been deferred.

IX. Recommendations *Continue annual inventory of deferred facilities and update deferred facilities list when warranted.*Conduct site characterization when possible, then remove investigated facilities from deferred list as appropriate.



No action has occurred at facilities included in this site.




OU 9 SD040 POND 7 AREA


III. Background The Pond 7 investigation area is located on the western edge of the Base, south of the West Gate and the Defense Reutilization and Marketing Office (DRMO) area. The DRMO is a military salvage yard, which has been used for storage of unneeded government property and scrap metal. Hazardous materials and hazardous waste may have been stored in this area. Pond 7 was constructed in 1976 and receives surface runoff from the DRMO area and other on-Base areas surrounding the pond. Subsurface soil, sediment, surface water, and groundwater near Pond 7 were investigated as part of the Pond 7 PA/SI. Risk analysis indicated that Pond 7 did not pose significant risks to human health or the environment. A NFRAP was developed for Pond 7 in 1998 (HAFB EMR 1998b). Pond 7 was mistakenly identified as Pond 6 in this NFRAP decision document.

During the basewide CPT investigation, TCE concentration above MCL was detected downgradient of the Pond 7 Area. The site was reopened for further investigation. Current data indicate that groundwater contamination, composed primarily of TCE, extends off-Base into the city of Clearfield. There may be several sources of contamination, but they have not been defined. TCE contamination has been found about 1/4 mile north of the pond and may be associated with past storage and use of solvents in the vicinity of the DRMO storage yard. Pond 7 may have received contaminated surface water runoff, and contaminants may have leached through the pond sediment into the shallow groundwater.

Investigation at the Pond 7 Area is part of the ongoing RI/FS investigation at OU 9. The estimated completion date for the OU 9 RI is April 2004 and the estimated completion date for the OU 9 ROD is June 2005.




I. Introduction The Pond 7 Area is under remedial investigation for soil and groundwater contamination. The need for remedial action has not been determined. This site is included in the 2003 Five-Year Review for completeness to document the site background and the status of the remedial investigation.




NA







This site was not included in the last Five-Year Review (HAFB EMR 1998a).A NFRAP was developed for Pond 7 in 1998 (HAFB EMR 1998b). The site was reopened for investigation when elevated TCE contamination was detected in the groundwater downgradient of the site during the basewide cone penetration testing (CPT) investigation in 2000 (MW 2000). Additional investigations to evaluate the extent of groundwater contamination and to identify the source areas are part of the ongoing RI/FS effort at OU 9. Four monitoring wells and five piezometers were installed, and groundwater was sampled in 2000. Groundwater mapping, CPT investigation, groundwater sampling, and groundwater elevation measurements were conducted in 2002. Evaluation of the data has not been published, but findings will be included in the OU 9 RI report scheduled for 2004.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable



Question C (Answer)

Not Applicable



VIII. Issues * Sources and extent of groundwater contamination have not been defined.* Gate near 6th Avenue, located on the southwest side of Pond 7, was not locked.

IX. Recommendations * Continue remedial investigation to identify the sources and extent of the groundwater contamination.* Continue institutional controls to limit human exposure to potential contamination. Secure all gates around Pond 7 to restrict access to potential contamination in the pond.








2008


SD040 is under remedial investigation and the need for remedial action has not been determined. However, institutional controls have been implemented to prevent human exposure to potential contamination. The site is included in the Continuing Order AFI 32-7020 (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater. A fence has also been installed around the pond to restrict access.




OU 9 SS089 1100 AREA


III. Background The 1100 Area is approximately 128 acres located in the western portion of the Base. Zone 11 includes the Base administration area, fire station (Building 1151), and several vehicle maintenance shops (Building 1133, 1135, 1140, and 1141). The groundwater contamination, composed primarily of TCE, extends off-Base into the city of Sunset. Contamination of the shallow groundwater is the result of improper handling of solvents and possibly of other petroleum products in this area. VOCs were detected in the shallow groundwater, but only TCE exceeded its MCL. No contaminants have been detected in the deep aquifer, possibly due to the thick silt and clay sedimentary units that could impede vertical migration of contaminants. There has been limited source area investigation and possible contaminants in soil include VOCs. Potential sources include the machine shops, vehicle maintenance garages, and utility shops.

Investigation at the 1100 Area is part of the ongoing RI/FS investigation at OU 9. The estimated completion date for the OU 9 RI is April 2004 and the estimated completion date for the OU 9 ROD is June 2005.




A preliminary conceptual site model of the 1100 Area was developed in 2000 based on data collected between Dec 1995 and April 2000. As part of the ongoing OU 9 remedial investigation, 11 monitoring wells were installed (U9-11-008 through U9-11-018) and groundwater sampling was performed in 2000. All wells are monitored semiannually. Additional investigation was conducted at on- and off-Base locations in 2002. Results of the investigations will be evaluated in the OU 9 RI report scheduled in 2004.



I. Introduction The 1100 Area is under remedial investigation for contaminated groundwater both on-Base and off-Base. The need for remedial action has not been determined. This site is included in the 2003 Five-Year Review for completeness to document the site background and the status of the remedial investigation.




NA





OU 9 SS089 1100 AREA


2008

Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable


investigation.

Question C (Answer)

Not Applicable



VIII. Issues Sources of groundwater contamination have not been defined.

IX. Recommendations * Continue remedial investigation to further define the sources and extent of the groundwater contamination.* Continue institutional controls to limit human exposure to potential contamination.



SS089 is under remedial investigation and the need for remedial action has not been determined. However, institutional controls have been implemented to prevent human exposure to potential contamination. The site is included in the Continuing Order AFI 32-7020 (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater. In addition, the Utah Division of Water Rights also restricts water well drilling and use of shallow groundwater in this area.





OU 9 SS090 ZONE 7 GOLF COURSE


III. Background The Golf Course Area is located on the southeastern edge of the Base. Contamination at the Golf Course Area is believed to be the result of improper handling of solvents and other products used in the Golf Course maintenance shop, Building 710. During wash down of the maintenance-building floor, overflow water from a former catch basin located south of the maintenance flowed across the land surface and collected in a drainage ditch along the Base boundary fence line.

Several VOCs have been detected, but the levels were below the risk-based screening levels. (MW 2000). Contaminants have migrated to the shallow groundwater. TCE and PCE have been detected above their respective MCLs in the groundwater. Local mounding of the groundwater table, caused by the irrigation of the Golf Course and the adjacent alfalfa field, may have carried contaminants upgradient of the suspected source area. It is believed that contamination in the shallow aquifer is not migrating to the deep drinking water aquifer because a 100-ft thick clay layer separates them. The TCE groundwater plume is approximately 200 ft wide and 900 ft long and is located at depth ranging from 26 to 50 ft bgs.

Investigation at the Golf Course Area is part of the ongoing RI/FS investigation at OU9. The estimated completion date for the OU 9 RI is April 2004 and the estimated completion date for the OU 9 ROD is June 2005.




Investigation focused on the southeast portion of the course was conducted between 1998 and 2000 and a preliminary conceptual model for the site was developed in 2000. Additional investigation, focused on the south and southwestern portion of the plume, was conducted between 2001 and 2002 in order to further delineate the horizontal and vertical plume boundaries. Five new monitoring wells (U9-07-007 through U9-07-011) were installed in


I. Introduction The Golf Course Area is under remedial investigation for groundwater contamination. The need for remedial action has not been determined. This site is included in the 2003 Five-Year Review for completeness to document the site background and the status of the remedial investigation.




NA





OU 9 SS090 ZONE 7 GOLF COURSE


2008

2000. All wells are monitored semiannually. This site has been included with the OU 9 RI, which is scheduled for completion in 2004.


Question A (Answer)

Not Applicable



Question B (Answer)

Not Applicable


investigation.

Question C (Answer)

Not Applicable



VIII. Issues Sources and extent of groundwater contamination have not been defined.

IX. Recommendations * Continue remedial investigation to identify the sources and extent of the groundwater contamination. * Continue institutional controls to limit human exposure to potential contamination.



SS090 is under remedial investigation and the need for remedial action has not been determined. However, institutional controls have been implemented to prevent human exposure to potential contamination. The site is included in the Continuing Order AFI 32-7020 (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater.





OU 9 SS108 800/900 WAREHOUSE AREA


III. Background Previous investigations at the 800/900 Warehouse Area indicate that the groundwater is contaminated mainly with chlorinated solvent and fuel-type compounds. Known sources of contamination include Site 914 UST and the industrial buildings located east and southeast of this site, and no other sources have been conclusively identified. The OU 8 RI concluded that the contamination at this site is not hydraulically connected to the OU 8 groundwater contamination plume. Investigation at the 800/900 Warehouse Area is part of the ongoing RI/FS investigation at OU9. The estimated completion date for the OU 9 RI is April 2004 and the estimated completion date for the OU 9 ROD is June 2005.




The 800 / 900 Warehouse Area was not reviewed for the 1998 Five-Year Review Report. Previous investigations at this site include the South Area Site Inspection for OU 9 in 2001, Remedial Investigation for OU 8 in 2000, basewide Underground Storage Tank Program at Building 914 in 1993, and basewide CPT Investigation in 2002. This site has been included with the OU 9 RI, which is scheduled for completion in 2004.


Question A (Answer)

Not Applicable





I. Introduction The 800/900 Warehouse Area is under remedial investigation for groundwater contamination. The need for remedial action has not been determined. This site is included in the 2003 Five-Year Review for completeness to document the site background and the status of the remedial investigation.




NA





OU 9 SS108 800/900 WAREHOUSE AREA


2008

Question B (Answer)

Not Applicable



Question C (Answer)

Not Applicable



VIII. Issues Sources and extent of groundwater contamination have not been defined.

IX. Recommendations * Continue remedial investigation to identify the sources and extent of the groundwater contamination. * Continue institutional controls to limit human exposure to potential contamination.



SS108 is under remedial investigation and the need for remedial action has not been determined. However, institutional controls have been implemented to prevent human exposure to potential contamination. The site is included in the Continuing Order AFI 32-7020 (HAFB 1998) and shown on the Restricted Use Access Map (updated 2/13/2003) to restrict the disturbance of soil and groundwater. In addition, the Utah Division of Water Rights also restricts water well drilling and use of shallow groundwater in this area.




Operable Unit 10

I Introduction

SS109, the 1200 Area, is the only site within OU 10 (see Table OU 10-1). The 1200 Area is located on the western edge of the Base near the West Gate (see Figure OU 10-1) and is heavily developed with streets and office space. Even though the space is primarily an administrative area, there are several maintenance facilities and a heating plant. One or more of these facilities are possible sources of contamination. The 1200 Area plume appears to extend off-Base toward the cities of Sunset and Clearfield, but the plume boundaries have not been fully delineated. An ongoing remedial investigation is scheduled for completion in December 2004, and because remedial action is anticipated, site SS109 has been included in this FYR. Remedial action objectives and remedies will be established upon completion of the OU 10 ROD scheduled for completion in December 2005. Table OU 10-1. OU 10 Site Identification

Site ID Site Name SS109 1200 AREA

II Site Chronology


III Background

The 1200 Area occupies approximately 146 acres along the western boundary of Hill AFB immediately north of the West Gate. The groundwater contamination, composed primarily of TCE, extends off-Base into the cities of Sunset and Clearfield. Contamination of the shallow groundwater is the result of improper handling of solvents and possibly of petroleum products in this area. Previous investigations (CH2M 2002) have shown the groundwater in the 1200 Area is present in two aquifers. The upper groundwater aquifer is located at 30 ft bgs and the lower aquifer is located at about 90-100 ft bgs. VOCs were detected in the groundwater; and TCE and PCE exceeded the MCL. TCE has been detected in the upper groundwater aquifer at concentrations as high as 45 µg/L, but was found at four times that concentration (180 µg/L) in the deeper groundwater aquifer. PCE has been discovered at 38 ft bgs at a concentration of 200 µg/L, but was not found at levels above the MCLs in the deeper groundwater aquifer (MW 2000). Potential sources of the contamination include the machine shops, vehicle maintenance garages, and utility shops. The highest concentration of TCE was recorded west of Building 1285, the optical shop, but a source for the contamination has not been determined. Development in the 1200 Area began in the early 1940s with the construction of combat equipment and inert-material warehouses for the Ogden Arsenal. In addition to the warehouses, two maintenance shops (Buildings 1243 and 1253), an optical shop (Building 1285), and a boiler house, now known as the heating plant (Building 1286), were built. Limited information is


available regarding specific materials that were stored in the combat and inert-material warehouses. Two 25,000 gallon underground storage tanks (UST) were installed in 1994 on the east side of Building 1286. The USTs store diesel fuel as a backup fuel supply for the plant and have a leak detection system. An isolated pocket of contamination has also been found just west of the base boundary, to the northwest of the primary area of contamination (see Figure OU 10-1). Previous investigations have not determined if this area is connected to the 1200 Area of contamination. The RI, once completed, may determine the source of this contamination. The 1200 Area was originally part of OU 9 until its redesignation to OU 10 in September 2000 in an effort to optimize investigation procedures and clearly define Operable Units with similar completion time frames. Area 1100 and the Defense Reutilization Marketing Office/Pond 7 Area were originally part of OU 10, but were placed back into OU 9 in late 2002 as the remedial investigation of the 1200 Area became more extensive. Land use in the 1200 Area today is largely administrative, with several vehicle maintenance facilities and the heating plant. The land use in the cities of Sunset and Clearfield, where potential contamination has been tentatively delineated, is residential.

IV Remedial Actions Remedial action has not been selected, however groundwater use restrictions are in place that

encompass the extent of the currently delineated plume (HAFB 1998). The site in OU 10 is under remedial investigation.


Not Applicable. This site had no remedial actions in operation at the time of the last Five-Year Review. Remedial action objectives will be established in the ROD, which is planned for completion in December 2005.


Question A. Is the remedy functioning as intended by the decision documents? No remedy has been selected. OU 10 is under remedial investigation.

Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid?

No changes in exposure assumptions, toxicity data, cleanup levels, or remedial action objectives have been identified. OU 10 is under remedial investigation.



No remedy has been selected. The site in OU 10 is under remedial investigation. VIII Issues

1. Sources and extent of groundwater contamination have not been fully delineated. 2. Indoor air sampling has not been conducted in off-Base residential areas potentially impacted

by the OU 10 plume. IX Recommendations and Follow-up Actions for OU 10

1. Continue remedial investigation to identify the sources and extent of the groundwater contamination.

2. Evaluate the selected remedy for protectiveness of human health and the environment in the next FYR scheduled in 2008.

3. Conduct air sampling in off-Base residences to determine if the new action level for TCE (0.43 ppbv) in indoor air warrants mitigation measures in off-Base residential areas. These samples should be collected during winter months when vapor intrusion will reach its maximum.


Not applicable. SS109, the 1200 Area, is still under remedial investigation and no remedy has been selected.

XI Next Review SS109, the 1200 Area, will be reviewed during the next FYR in 2008. XII References for Operable Unit 10 Summary

(CH2M 2002) OU10 Remedial Investigation/Feasibility Study Operable Unit 10 Analytical Data Report, May 1 2001 - January 31 2002, CH2M Hill, July 2002. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (MW 2000) Final Data Summary Report and Preliminary Conceptual Model for Operable Unit 9 Investigation Areas, Montgomery Watson, October 2000.



SS109 1200 AREA BUILDINGS1995 Site Inspection SI approach was designed to focus on the 311 facilities most

likely to have released contaminants to the environment. The objective was to evaluate whether environmental contamination was present at each facility of potential concern, and to categorize each facility according to its threat to human health and the environment.

North Area Preliminary Assessment Report, June 1995, Final

12 1995 Site Inspection Field data was collected between Dec 1995 and Mar 1998 for various OU 9 investigation sites.


09 2000 Site Inspection Redesignation of groundwater contamination plumes identified during OU 9 investigations. SS109, the 1200 Area, redesignated as OU 10.


05 2001 Remedial Investigation Sampling being conducted in potentially contaminated area in the cities of Sunset and Clearfield.

OU 10 RI/FS, Operable Unit 10 Analytical Data Report, May 1, 2001 - January 31, 2002

02 2004 Scheduled Remedial Investigation Final RI to be completed. NA





03 2005 Scheduled Feasibility Study Final FS to be completed. NA

12 2005 Scheduled Record of Decision Final ROD to be completed. NA




Operable Unit 11

I Introduction

OU 11 consists of one site, OT097 or former Building 454, which was the location of the Base Exchange Service Station and the Auto Care and Auto Parts Store at Hill AFB (Table OU 11-1). There is currently no ROD in place for OU 11. Due to the previous activities at the site, namely gasoline pumping and car maintenance, three plumes, consisting of benzene, toluene, ethylbenzene, and xylenes (BTEX); TCE; and methyl tert-butyl ether (MTBE) are suspected and are being delineated in the remedial investigation (RI) at the site. Two UST sites are located in the vicinity of Building 454 and are not discussed in detail because UST sites are not a part of this CERCLA review process. The RI for site OT097 should be complete in late 2004. Because this site is being actively investigated, it has been included in this FYR. Table OU 11-1. OU 11 Site Identification

Site ID Site Name OT097 Building 454

II Site Chronology


III Background

Building 454, shown in Figure OU 11-1, was located at the corner of 6th Street and E Avenue on Hill AFB, approximately 150 feet southeast of the current Auto Pride gasoline station (Building 420) (MW 2001). The Building 454 facility included four maintenance bays inside the building. Each maintenance bay contained a mud and grease trap that collected waste liquids and delivered the waste to an oil/water separator. Between 1957 and 1980, two fuel tanks (a 6,000-gallon “ethyl [sic]” tank and an 8,000-gallon regular tank) and a 500-gallon waste oil tank were located on the north side of the facility. The site was upgraded in 1963 and renovated in 1980 (MW 2000). The age of the tanks would suggest that other fuel types such as regular gasoline and diesel could have been stored at the site in the past (DM 1994). In August 1995, the original USTs and associated piping were removed. Building 454 and the north pump island were demolished in the summer of 1999, and the new Base "Auto Pride" gasoline station (Building 420) was constructed (MW 2000). The former underground storage tanks passed tightness tests performed in 1991, 1992, 1993, and 1994 suggesting that the tanks were structurally intact. Thus, the probable cause of contamination is believed to be spills and overfills (DM 1994, Smith, S. 2003). The range of contaminants is suggestive of impact from former diesel and gasoline tanks, the oil-water separator, and solvents that may have been released during former Building 454 maintenance activities. In addition, the presence of MTBE may suggest a more recent source for at least some of the gasoline-related contamination (MW 2000).


A possible release was detected on August 23 and 24, 1993, during environmental soil sampling near the operating tanks. Hydrocarbon odors were noted and organic vapors were recorded with a PID while collecting subsurface soil samples near the base of the tanks. Laboratory results from analysis of soil samples indicated petroleum hydrocarbons were present in soils. The release was reported to the Utah Division of Environmental Quality, Division of Environmental Response and Remediation (UDEQ, DERR) verbally on October 1, 1993 by Dames and Moore, and written communication was submitted October 7, 1993 by EMR (DM 1994). During the demolition of Building 454, a tractor-trailer loaded with regular gasoline pulled into the site parking lot and brushed a tree, pulling off a valve cover that resulted in a release of unleaded fuel. In a spill report filed shortly thereafter, it was estimated that 5 gallons were released into the storm drain. The remaining surface fuel was picked up and overpacked (HAFB EMR 2000). Previous investigations (DM 1994; CH2M 2001a; CH2M 2001b) identified soil and groundwater contamination at the site. Trace concentrations of solvents were detected in addition to hydrocarbons in groundwater, while only hydrocarbons were detected in soil. In light of this, the decision was made to divide the site in an effort to address these separate issues. After meeting with both leaking underground storage tank (LUST) and CERCLA regulatory personnel, the decision was made that free-product and soil (vadose zone) contamination would be addressed under the LUST section of UDEQ, DERR while the groundwater contamination would be addressed under CERCLA (CH2M 2002). Land use in the immediate vicinity of former Building 454 is industrial. No residential areas share a common property boundary with the site. Surrounding land use in the area around Hill AFB is varied and includes uses as diverse as agriculture and heavy industry (CH2M 2001b). There are no culinary or municipal water rights within the vicinity of the plume. Water rights restrictions are in place for potentially affected groundwater associated with the site (Hill 1998).

IV Remedial Actions No remedial actions are established at this time. V Progress Since Last Five-Year Review

The last Five-Year Review of Building 454 was in September 1998 under OU 9 (HAFB EMR 1998), which yielded no suggestions or recommendations. At the time of the 1998 review, investigation was underway to determine if additional contaminants (other than petroleum) were present. Numerous investigational activities have either commenced or been completed. TCE was identified as a contaminant at the site as well as MTBE and BTEX. Therefore, the source of the TCE, MTBE, and BTEX and their dissolved-phase plumes are being delineated through the use of CPT and Hydropunch technologies as well as monitoring well installation. Due to the elevated level of contamination, relative to other OU 9 sites, the OT097 site (or Building 454) has been redesignated as OU 11. A draft RI report is expected late in 2004 with an FS to follow.





Question A. Is the remedy functioning as intended by the decision documents? Not applicable. There is no remedy at this site.

Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? Not applicable. There is no remedy at this site. A draft RI report is scheduled for submission in late 2004.


Not applicable. No remedy is in place at this time. VIII Issues

Definition of the volume and extent of the BTEX, TCE, and MTBE dissolved-phase plumes is not yet completed at the OU11 site.


1. Perform a comprehensive groundwater characterization for contaminants of concern in the groundwater. Compile characterization information in the RI report and generate FS.

2. Select and implement a remedy, if required, in accordance with CERCLA criteria.


Not applicable. Protectiveness cannot be determined or evaluated until the remedial investigation is complete and a remedy, if required, is selected and implemented. Additional investigational work is underway to define the extent of the BTEX, TCE, and MTBE dissolved phase plumes. A Draft RI report will be submitted late in 2004 with an FS to follow.

XI Next Review The next FYR for OU 11 is required by 2008. XII References for Operable Unit 11

(CH2M 2001a) Final South Area Of Operable Unit 9 Site Inspection, Final Comprehensive Data Evaluation, Volume 1, CH2M Hill, February 2001. (CH2M 2001b) Subsurface Investigation Report for Underground Storage Tank Site 454, CH2M Hill, February 2001.


(CH2M 2002) OU11 Remedial Investigation/Feasibility Study, Operable Unit 11 Analytical Data Report, May 1 2001 - January 31 2002, CH2M Hill, November 2002. (DM 1994) Final Draft Abatement and Initial Site Characterization Report Building 454, Site EIHG, Dames and Moore, October 1994. (HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. (HAFB EMR 1998) CERCLA 1998 Five-Year Review Hill Air Force Base, Utah, Hill AFB EMR, September 1998. (HAFB EMR 2000) Comprehensive Event Report, Hill AFB, November 2000. (MW 2000) Building 454 Investigation Tech Memo Operable Unit 9 Final, Montgomery Watson, November 2000. (MW 2001) Final Analytical Data Report (ADR) For Operable Unit 9 Investigation Areas 1 May Through 10 October 2000, Montgomery Watson, February 2001. (Smith, S. 2003) Smith, S., Project Engineer, Hill AFB, EMR, Personal Communication, 19 February 2003.



OU 11 OPERABLE UNIT 1109 2000 Zone 7 - Golf Course Area (Site

SS090) and Former Building 454 (IRP site OT097) were redefined as OU 11 instead of OU 9

The re-designation was a result of efforts to optimize investigation procedures and more clearly define operable units with similar completion time frames.


2002 OU 11 Realignment At one point, the golf course, 800&900 warehouse buildings, and Building 454 were all a part of OU 11. After further delineation of the contamination, the golf course and the 800&900 warehouse buildings were placed back into OU 9 because they had low levels of TCE contamination and will likely have similar remedies. The contaminants, contaminant levels, and potential remedies for Building 454 are different and more complex than the other two sites, so it remained in OU 11. A letter was sent to the regulators on 30 September 2002 proposing this realignment between OUs 11 and 9. Verbal concurrence was received from the regulators in a subsequent meeting.

Personal Communication with Sheri Rolfsness, OU 11 Project Engineer (EMR), on 12/31/02

OT097 GAS STATION (454)1957 Use of Building 454 area between

1957 and 1999Building 454 was located in the South Area of Hill AFB, UT and served as the Base Exchange Service Station, Auto Care, and Auto Parts facility between 1957 and 1999.

Final Draft Abatement and Initial Site Characterization Report Building 454, Site EIHG





1963 Building 454 upgraded in 1963 The station was upgraded around 1963 to add two maintenance bays on the west end of the building and to construct an additional pump island on the east end of the building.

Building 454 Investigation Tech Memo Operable Unit 9 Final

1980 Site renovated The site was renovated in 1980 by relocating all three pump islands to the north of the building. At this time, the station had three fuel storage tanks just north of the east end of the building. The tanks consisted of an 8,000-gallon "regular" gasoline UST, a 6,000-gallon "premium" gasoline UST, an 8,000-gallon "no-lead" gasoline UST, and a 500-gallon waste oil UST.


1993 Preliminary Subsurface Investigation

In 1993, Hill AFB initiated a preliminary subsurface investigation at several of the UST locations to evaluate the potential for petroleum contamination in soils as a result of leaks, spills, and overfills (Dames and Moore, 1994).


08 1993 Possible Release A possible release was detected on August 23 and 24, 1993, during environmental soil sampling near the operating tanks. Hydrocarbon odors were noted and organic vapors were recorded with a PID while collecting subsurface soil samples near the base of the tanks. Laboratory results from analysis of soil samples indicated petroleum hydrocarbons were present in soils. The release was reported to the DERR verbally on October 1, 1993 by Lori Robison of Dames and Moore. A written communication was submitted October 7, 1993 by Kevin Bourne of EMR.






1995 Another potential 25,000 gallon UST was identified in the South Area Preliminary Assessment Report

However, no evidence of this site was found during the South Area OU 9 Site Inspection site visit, no further action was recommended.

Work Plan for South Area of Operable Unit 9 Site Inspection Volume 1: Report and Appendices A-D

08 1995 Original USTs and associated piping removed

In August 1995, the original USTs and associated piping were removed and (1) 12,000-gallon and (2) 10,000-gallon fuel tanks were installed, replacing the previous tanks.


12 1995 Horizontal SVE The USTs were removed in 1995 and five soil vapor probes and one horizontal soil vapor extraction wells were installed in the tank basin under the UST program (DM, 1996). The horizontal SVE well was installed to a depth of 10.5 feet bgs and was located 43 feet north from (perpendicular to) the north side of the building. The SVE system was in operation from December 1995 until February 1998. The LUST site (EIHG) was closed with no further action required.

Draft Subsurface Investigation Report and Corrective Action Plan for Building 454, LUST Site EIHG

1999 Demolition Building 454 and the north pump island were demolished in 1999, and the new Base "Auto Pride" gasoline station (Building 420) was constructed with new pump islands south of the new building.


02 1999 Gasoline Spill During demolition of Building 454 in February 1999, a tractor-trailer loaded with regular gasoline pulled into the site parking lot and brushed a tree, pulling off a valve cover that resulted in a release of unleaded fuel. In a spill report filed shortly thereafter, it was estimated that 5 gallons were released into the storm drain. Remaining surface fuel was picked up and overpacked.

Comprehensive Event Report





08 2000 Another UST added to the Auto Pride gas station

In August, 2000, a fourth 10,000-gallon tank was installed due to fuel demand at the station.





Operable Unit 12

I Introduction

OU 12 consists of one site, SS107, which encompasses what is believed to be one of the source areas for the associated TCE contaminated groundwater plume (Table OU 12-1). This plume was discovered in 2000 during remedial investigation activities for OU 5 and is being delineated in the RI for OU 12. A draft of the RI should be complete in the summer of 2003. There is no ROD in place for OU 12. Currently there is a Hydraulic Containment Treatability Study System in the final stages of construction on Base at the Base boundary. Therefore, OU 12 and site SS107 have been included in this FYR. Table OU 12-1. OU 12 Site Identification

Site ID Site Name SS107 ASPEN AVE. DISPOSAL AREA

II Site Chronology


III Background

Operable Unit 12 is located in the northwest region of Hill AFB and is comprised of contaminated groundwater beneath the area northwest of the former Wastewater Treatment Plant and west of the MAMS-2 area, and off-Base areas beneath the city of Roy (see Figure OU 12-1). The OU 12 plume begins on-Base in the area northwest of the former WWTP and continues north and northwest beneath the Davis-Weber Canal, Interstate Highway 15, Union Pacific Railroad, 2700 West, and apparently terminates west of the Denver and Rio Grande Railroad. The depth to groundwater at OU 12 varies from approximately 3 feet bgs in the vicinity of 2700 West off-Base in Roy to approximately 110 feet bgs on-Base in the vicinity west of the MAMS-II area and north of the former WWTP. The exact on-Base origin of the OU 12 contaminant plume is not known at this time. When the plume was first discovered, it was thought that the possible source was the former WWTP (MWH 2002). However, a soil-gas survey, Cone Penetration Testing (CPT), and direct push groundwater sampling indicate that the source is located north of the former WWTP (MWH 2002). This northern area is characterized by debris, half-buried drums, abandoned foundations, and several trench-like features. Additionally, ash beds with vitrified material (suggesting possible rocket testing or propellant burning) were identified north and west of the former WWTP. Finally, increasing and/or highly variable TCE concentrations in the OU 12 source area, and particularly in MW U9-16-011, indicate a continuing source. Currently, a Hydraulic Containment Treatability Study System is being constructed on-Base to prevent highly contaminated groundwater from crossing the Base boundary.


IV Remedial Actions

No remedial actions are currently in place at OU 12. A Base Boundary Hydraulic Containment Treatability Study System is in the final stages of construction as of March 2003. This is a pump and dispose system. Its goal is to contain contaminated groundwater within the area defined by the 100 µg/L TCE contour at the Base boundary. Remedial measures to protect human health will be addressed after completion of the RI/FS and ROD and are scheduled to be in place by 2007 (Loucks, M. 2003). Groundwater use restrictions are in place that encompass the containment plume (HAFB 1998).

V Progress Since Last Five-Year Review This site had not been established as an IRP site at the time of the last Five-Year Review. VI Five-Year Review Process Site review was conducted per the process described in this report for the overall 2003 FYR. VII Technical Assessment

Question A. Is the remedy functioning as intended by the decision documents? To be determined. The system is currently under construction.

Question B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objective (RAOs) used at the time of the remedy still valid? Not applicable. The system under construction is a Treatability Study and the RI/FS and ROD for this site are not complete, so there are no formal RAOs for the site. The goal of this system is not to achieve reduction of TCE concentrations down to the MCL, but to contain contaminated groundwater within the area defined by the 100 µg/L TCE contour at the Base Boundary.

Question C. Has any other information come to light that could call into question the protectiveness of the remedy? Not applicable. There is no remedy functioning at this site. There is a treatability study currently under construction.

VIII Issues

Based on the information reviewed and interviews and inspections conducted, issues that may affect protectiveness at OU 12 are listed below:

1. It appears that the source of contamination in OU 12 has not yet been fully delineated. 2. The depth to groundwater is very shallow in some areas of the contaminant plume and

samples from the basements of 8 houses off-Base have demonstrated indoor air contamination from the TCE present in the shallow aquifer beneath them. This contamination has been addressed in seven of the houses by installing air exchange units in the basements, but there is apparently one that has not yet allowed access to mitigate the


situation. There is potential for indoor air quality to become a problem in other homes above very shallow portions of the plume.

3. There is one location off-Base (see Figure OU 12-1) where it is suspected that groundwater

surfaces within the confines of the OU 12 plume. This is a depressed area that encompasses residential properties (these properties have an underdrain system). The area is dry some times of the year and wet other times of the year. However, CPT in this area has shown that groundwater is located virtually at the ground surface (Mills, D. 2003). According to Dave Mills, this water has been sampled in the past and no contamination was detected.



1. Delineate and remove the source area.

2. Continue with installation of the Base Boundary Hydraulic Containment Treatability Study System, as it should allow for continuing work to remove and investigate the source area without concern of contaminant migration off-Base.

3. Consider the possibility of an early action to address the area of the plume off-Base where basements are being affected.

4. Determine areas of potential risk for indoor air contamination and develop a sampling plan to catch and address any contamination early. Any indoor air samples should be collected during winter months when vapor intrusion will reach its maximum.

5. Institute a sampling plan for the location off-Base where groundwater surfaces to identify any contamination, if it exists, as early as possible.

X Protectiveness Statement for OU 12 The remedy at OU 12 is not protective. The current remedy is not intended to be protective of

human health but is a treatability study meant to prevent highly contaminated groundwater from migrating off-Base. Remedial measures for the contaminated groundwater will be addressed after completion of the RI/FS and ROD and are scheduled to be in place by 2007. Although there are groundwater use restrictions in place that encompass the contaminant plume, there are areas within the plume and beneath residences, where groundwater is very shallow and indoor air quality is a concern. Hill AFB has installed vapor removal systems in several residences where TCE concentrations have been found to exceed human-health based screening values and will continue to address such cases as they are identified.

XI Next Review The next FYR for OU 12 is required by 2008. XII References for Operable Unit 12 Summary

(HAFB 1998) OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998.


(Loucks, M. 2003) Loucks, M., Historical PM, Hill AFB EMR, Personal Communication, 11 February 2003. (Mills, D. 2003) Mills, D., Project Manager, EMR, Personal Communication, 05 March 2003. (MWH 2002) OU 12 Base Boundary Hydraulic Containment System Work Plan, Montgomery Watson Harza, June 2002.



OU 12 OPERABLE UNIT 1201 1999 OU 5 RI Investigation Reopened.

Investigation includes OU 12.Investigations performed throughout OU 9 between 1996 and 1998 identified the existence of a VOC GW plume (now known as the Zone 16 plume) in OU 5 substantially larger than that addressed in the 1995 OU 5 RI. This reopened investigation has lead to a separate OU 12 RI that is scheduled to be complete in draft form by mid-summer 2003.


10 2001 The northern GW contamination plume within OU 5 is designated OU 12.

This plume was discovered in 2000 during additional environmental investigations for the re-opened OU 5 RI.


09 2002 Final Conceptual Model for Operable Units 5 and 12 completed

This document provides a conceptual model for the fate and transport of contaminants in groundwater at Operable Units 5 and 12. It interprets and presents the results of investigation tasks performed at OUs 5 & 12 by MWH and other contractors as part of the revised RI (not yet complete) including: Monitoring well installation, groundwater and surface water sampling, CPT and direct-push groundwater sampling, field drain sampling, aquifer testing, in-situ permeability testing, soil sampling, water-level monitoring, residential air and water sampling, historic site review, low-flow sampling study, active soil-gas survey, etc.

Final Conceptual Model for Operable Units 5 and 12





SS107 ASPEN AVE. DISPOSAL AREA06 2002 Final Operable Units 5 and 12

Active Soil-Gas Survey Source Area Investigation Report completed

Soil-gas investigation conducted to define source areas in OU 5 and 12. This investigation indicated that the source area for OU 12 was north of the former WWTP.

Final Operable Units 5 and 12 Active Soil-Gas Survey Source Area Investigation Report

06 2002 OU 12 Base Boundary Hydraulic Containment System Work Plan delivered

This is the work plan for a treatability study on-Base at the Base boundary.

OU 12 Base Boundary Hydraulic Containment System Work Plan



Appendix A

Comments on Preliminary and Draft Versions of Five-Year Review Report

A.1 Hill AFB EMR Response to May DRAFT of Five-Year Review Report

A.2 Restoration Advisory Board Comments on May DRAFT of Five-Year Review Report

A.3 UDEQ Comments on May DRAFT of Five-Year Review Report A.4 USEPA Comments on May DRAFT of Five-Year Review Report

Appendix A.1

Hill AFB EMR Response to May DRAFT of Five-Year Review Report

5YR response OU 1 URS 1 of 3

Hill Air Force Base Response to Five Year Review for Operable Unit 1

Five Year Review Item Hill AFB Response URS Action

Recommendation 1, Section IX - “Re-evaluate the non-source area monitored natural attenuation remedial action to determine if it is still applicable in all non-source areas (specifically in the area of measurable hydrocarbon concentrations outside Trench D).”

Concur No action.

Recommendation 2, Section IX – “Modify ERPIMS to indicate springs and seeps that are dry during a sampling event.”

Concur No action.

Recommendation 3, Section IX – “Review the long term monitoring sampling and analysis plan to ensure that locations where the hydrocarbon concentrations were located during the Source Zone Area Delineation project (Intera 2001) are sampled.”

Concur No action.

Recommendation 4, Section IX – “Proceed with the delineation and excavation of the arsenic contaminated soils at the springs.”

Hill AFB is currently working to evaluate the efficacy of the extraction trenches and continues to monitor spring flows in the area. Arsenic contamination will be remediated when Hill is convinced that the extraction trenches are effectively preventing flow at the springs, especially during wetter years.

No action.

Hill Air Force Base Response to

Five Year Review for Operable Unit 1 (continued)


Five Year Review Item Hill AFB Response URS Action Recommendation 5, Section IX – “Determine if the trenches are containing/capturing the contamination in the source area by evaluating the gradient around the trenches. Additional monitoring points may be necessary to confirm that the prescribed water levels in the sumps are adequate to maintain containment”

Concur. Work related to this recommendation is planned for this year.

No action.

Recommendation 6, Section IX – “Re-evaluate the risk analysis for OU 1 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors, as explained in the Technical Assessment above.”

Concur No action.

Recommendation 7, Section IX – “Re-evaluate the RI data on indoor air and determine if the new action level for TCE (0.43 ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.”

Concur. Hill AFB has plans in place to sample indoor air in residential areas associated with OU1 next fall/winter.

No action.

Recommendation 8, Section IX – “Address drainage and ponding issues on Landfills 3 and 4 as soon as they are identified to ensure the landfill cap integrity.”

Concur No action.

Recommendation 9, Section IX – “Ensure that all gates and fences are locked in accordance with the ROD-specified institutional controls.”

Concur No action.


Five Year Review for Operable Unit 1 (continued)


Five Year Review Item Hill AFB Response URS Action Recommendation 10, Section IX – “Determine if the plume mean concentrations are decreasing, using the described locations and monitoring frequency outlined in the PSVP and the results of the PSVR, scheduled for 2006.”

Concur No action.

Recommendation 11, Section IX – “Ensure that the method detection limits (MDL) are low enough to detect a contaminant of concern (i.e., MDL equal to or less than the MCL or PRG).”

Concur No action.

Recommendation 12, Section IX – “Collect samples from all locations described in the PSVP and ensure that the results are entered in ERPIMS.

Concur No action.

Recommendation 13, Section IX – “Continue to perform landfill cap inspections.”

Concur No action.

Protectiveness Statement: Hill AFB concurs with the protectiveness statement.

No action.




Recommendation 1, Section IX - “Jointly evaluate the effectiveness of the SRS and the containment wall.”


No action.

Recommendation 2, Section IX – “Identify the appropriate action level for well field operations and document new level and rationale in the PSVP.”

Concur No action.

Recommendation 3, Section IX – “Water level and analytical data in the vicinity of the NIT, the performance of the NIT, and the location of the NIT with respect to the dissolved-phase plume should be thoroughly evaluated.”


No action.

Recommendation 4, Section IX – “Expedite submittal of LTM data to ERPIMS for timely review of remedy effectiveness.”

Concur No action.

Recommendation 5, Section IX – “Continue use of the portable DNAPL pump assembly to remove free-phase DNAPL from wells. Consider purchase of a second system, which would enable simultaneous recovery of DNAPL from wells within the containment wall and from wells in the G-Pool.”

Concur No action.


Five Year Review for Operable Unit 2 (Continued)


Five Year Review Item Hill AFB Response URS Action Recommendation 6, Section IX – “Investigate the relationship between new residential development and the plume.”

Concur No action.

Recommendation 7, Section IX – “Re-evaluate the risk analysis for OU 2 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors, as explained in the Technical Assessment above.”

Concur No action.

Recommendation 8, Section IX – “Consider the need to restrict water rights in the northeast quarter of Sect. 29, T5N R1W.”

Concur No action.

Recommendation 9, Section IX – “Evaluate whether a thorough review of the remedies at OU 2 can be performed before 2006.”

Concur No action.


No action.




Section IX, Recommendation 1 – “Re-evaluate the risk analysis for the active sites at OU 3 to determine if revised contaminant action levels are warranted based on new standards and toxicity factors as explained in the Technical Assessment above.”

Concur. Since the remedy is in place, effectively preventing a completed exposure pathway, changes in toxicity factors will not alter the remedies protectiveness. If however in the future work compromised the integrity of the cap, then a re-evaluation of the risk analysis would be warranted.

Text revised as follows: “Re-evaluate If future work compromises the integrity of the remedies at OU 3, the risk analysis for the active sites at OU 3 should be re-evaluated to determine if revised contaminant action levels are warranted based on new standards and toxicity factors as explained in the Technical Assessment above.”

ST004 – Sodium Hydroxide Tank Site Section IX, Recommendation 2 – “Continue inspection and monitoring program for the cap.”

Concur No action.

Section IX, Recommendation 3 – “Patch any damaged areas of the cap in the areas where the roll-off bins were located.”

Concur No action.

Section IX, Recommendation 4 – “Continue with the current groundwater-monitoring plan.”

Concur No action.

Section IX, Recommendation 5 – “Add painted delineations to the perimeter of the asphalt cap.”

Concur No action.

Section IX, Recommendation 6 – “Post warning signs prohibiting storage of equipment and excavation without permission.”

Concur No action.

Section IX, Recommendation 7 – “Develop procedures for excavation and equipment storage to minimize defects in the asphalt cap.”

Concur No action.




Five Year Review Item Hill AFB Response URS Action WP005 – Berman Pond

Section IX, Recommendation 8 – “The PSVP should be revised to document the change of remedial actions at the site (the groundwater contamination from Berman Pond is captured by the OU 8 interim remedial action and therefore the pumping action level is not required).”

Concur No action.

Section IX, Recommendation 9 – “Change the watering scheme for the landscaping around the asphalt cap at Berman Pond according to the recommendations made following the September 2002 cap inspection (Vicelja, J. 2002).”

Concur No action.

Section IX, Recommendation 10 – “Slurry seal the asphalt cap in the summer of 2003 to prevent excess infiltration according to recommendations made following the September 2002 cap inspection (Vicelja 2002).”

Concur No action.

Section IX, Recommendation 11 – “Post warning signs prohibiting storage of equipment and excavation without permission.”

Concur No action.

Section IX, Recommendation 12 – “Add painted delineations to the perimeter of the asphalt cap.”

Concur No action.




Five Year Review Item Hill AFB Response URS Action SD046 – Pond 2 Section IX, Recommendation 13 – “Determine what restrictions, if any, were applied to the deed.”

Do not concur. Investigations were completed at this site, before the sale to ensure it was not a source of ground water contamination. These investigations showed there was no significant contamination present and consequently there was no need to consider restricting activities by a restriction to the deed.

Agreed. This recommendation has been deleted.

Protectiveness Statement: Hill AFB does not concur with the protectiveness statement. The current remedy is protective because there is no completed exposure pathway. Changes in risk factors do not alter the protectiveness of the remedy. If however, future work compromised the integrity of the cap, then a re-evaluation of the risk analysis would be warranted.

Text revised as follows: “A protectiveness determination of Tthe remedies associated with OU 3 cannot be made until further information is available are protective of human health and environment. However, wWithin the time between the remedy selection and this Five-Year Review, USEPA has published changes to toxicity factors that affect chemical-specific clean-up levels at OU 3. Therefore, if future work at OU 3 compromises the integrity of the remedies, a re-evaluation of potential risk at OU 3 must be conducted to determine if revised contaminant action levels are warranted based on new standards and toxicity factors. before the protectiveness of the current remedies can be determined.

Additional items that need to be addressed are described in the previous issues and recommendations and include revision of the PSVP to document the change of remedial action at the site. A completed PSVR, due in




Five Year Review Item Hill AFB Response URS Action 2006, will be useful for determining the protectiveness of the remedial actions at OU 3 during the next Five-Year Review (2008).”




Thoroughly evaluate existing data and determine if additional data and/or modeling are required to develop a plume management plan that meets the RAOs.

Concur No action.

Evaluate clean-up levels for COCs and amend the ROD, if required, to address current ARAR levels.

Concur No action.

Complete an investigation to identify all source areas near the Landfill 2 (LF012) and the North Gate Dump areas (OT014) as well as sources near the HDUS contributing to the OU 4 contaminant mass.

Do not concur: Hill will continue to monitor wells in the plume area. Additional wells may be installed to fill data gaps. A study is currently being initiated to evaluate the OU 4 monitoring system and recommend additional wells if needed. If sustained increasing trends are observed, which result in an expansion of plume boundaries, an evaluation will be made to determine if additional source area characterization is warranted.

Concur. Recommendation revised as follows: “Continue to monitor wells in the plume area and if sustained increasing trends are observed, which result in an expansion of plume boundaries, an evaluation should be completed to determine if additional source area characterization is warranted.”

Address the above issues and recommendations in a PSVR prior to the scheduled timeframe of 2006 (FFA schedule).

Concur: See previous comment. No action.

Complete an in-depth review of the existing data as they pertain to the effectiveness of the landfill cap. If the existing data do not provide an adequate assessment of the landfill cap effectiveness, make recommendations for additional data.

Do not concur: During construction of the cap quality control measures were taken to ensure the target permeability (1x10-7 cm/s) specifications were met. The current cap maintenance program identifies damage done to the surface that might affect the caps performance. If damage is identified, repairs are made to ensure the cap continues to inhibit infiltration of surface water.

This recommendation stemmed from the analytical results from the downgradient landfill monitoring locations (U4-046 and U4-047). U4-047 has shown an increase in TCE concentration from 2,000 ppb in 1999 to 12,000 ppb in 2002. Recommendation revised as follows: “Complete an investigation into the increase of TCE concentrations in U4-047 and closely monitor future analytical results from this location.”




Five Year Review Item Hill AFB Response URS Action Establish flow levels for implementation of a surface water collection and treatment system at the seeps.

Concur No action.

Conduct a site investigation of the buried drain line area to determine the extent of contamination.

Concur: This was accomplished after the drain line was repaired. Trace levels (low ppb) of TCE were detected in the soil that should not pose a threat to the environment.

Concur. Recommendation removed.

Protect drain lines from damage with proper soil cover.

Concur: The exposed 2’ sections are elbows where cleanouts are planned. Eroded areas will be backfilled with soil.

No action.

Install additional signage to prevent unauthorized off-Base excavation.

Concur No action.

Evaluate the causes of reduced flows in the HDUS drain sets (upper, middle, and lower horizontal drain sets) (see Figure OU 4-1) using video logs and flow data. Access points at each drain line may be necessary to allow a video log and to obtain the flow data of each line.

Concur: Flows were evaluated and plans are in place to clean the upper, middle, and lower drain sets.

No action.

Data from the sumps in Landfill 1 and the drain set flows of the HDUS system should be included in the ERPIMS database to allow for trends to be examined. All data that are required in the PSVP should be included in the database. If no data are available during the sampling round or if a point has been discontinued, it should be noted in the database for clarification.

Concur No action.




Five Year Review Item Hill AFB Response URS Action In the case of a change of circumstances (flow rates, land use, land ownership, land access, etc.), surface water controls will need to be reevaluated and implemented.

Concur No action.

Hill AFB is currently evaluating the existing well network to determine if it is adequate to monitor conditions within and at the distal edges of the plume. Initial indications are that the current network needs to be expanded, particularly at the distal end of the western lobe.

Recommendation added: “Evaluate existing well network to determine if it is adequate to monitor conditions within and at the distal edges of the plume and add additional monitoring locations as necessary.”

Protectiveness Statement: Hill AFB concurs that the remedies at OU 4 are currently protective of human health and the environment. No one is currently being exposed to contaminants in the groundwater at the site. However, there are issues that need to be addressed. Hills evaluation of the western lobe suggests this is an area where there is potential for plume expansion. Additional monitoring will be done to assess whether or not the plume is stable, and hence may or may not represent a potential future risk to residents that live down gradient.

No action.



Five Year Review Item Hill AFB Response URS Action Section VIII, Issue 5 – “There has been no published evaluation of indoor air quality in residences above the plumes. However, according to EMR, the Draft RI, to be completed the summer of 2003, includes indoor air sampling that indicates indoor air is not a problem.”

Recent sampling events have not detected indoor air problems. However, due to improved sampling methods and understanding of indoor air issues, Hill AFB will continue to monitor indoor air in the OU5 area.

No action.

Section IX, Recommendation 1 – “Evaluate the life expectancy of the site SS017 Phase I (aeration curtain) system and if appropriate replace the blowers with an air compressor.”

Concur. Hill AFB has already performed an engineering cost evaluation and determined that replacing the existing air sparge blowers with air compressor is not cost effective. Oil- less air compressors are expensive and the system will need two (2) air compressors.

No action.

Section IX, Recommendation 2 – “Clean the site SS017 Phase I (aeration curtain) sparge lines and develop a preventive maintenance process to prevent unplanned system shutdowns in the future.”

Concur. Procedures for sparge line cleaning are included in the O&M manual. Hill AFB will follow up with the O&M contractor to ensure that appropriate maintenance activities are being completed.

No action.

Section IX, Recommendation 3 – “Increase ventilation in the site SS017 Phase I (aeration curtain) blower building.”

Concur. Hill AFB is currently evaluating alternatives to increase ventilation in the blower building.

No action.

Section IX, Recommendation 4 – “Shut down the site SS017 Phase II (groundwater extraction) system.”

Concur No action.




Five Year Review Item Hill AFB Response URS Action Section IX, Recommendation 5 – “Continue all institutional controls, primarily, groundwater-use restrictions on the shallow aquifer beneath sites SS017 and SS091 (HAFB 1998).”

Concur No action.

Protectiveness Statement: Hill AFB concurs in general with the protectiveness statement. However, the statement that “It appears that the 5 to 100 µg/L portion of the SS017 plume has passed the Phase III (groundwater extraction trench) location and, therefore, will continue to migrate further into the city of Clinton”, is contrary to the results of analyses performed by Hill AFB. Hill’s analysis suggests that dissolved TCE plume in Clinton may grow by another 500 feet, but that concentrations will decrease rapidly and will be below the MCL in less than twenty years.

After review of the document that prompted this response (Final Contaminant Transport Model Report for Operable Unit 5, Feb, 2002, MWH), the text was revised as follows: “Currently, conditions in the groundwater downgradient of the trench (Figure OU 5-1) are between 5 and 100 µg/L. According to modeling conducted for Hill AFB (MWH 2002d), contamination at these concentrations will remain in the groundwater for between 20 and 30 years.”




Continue the long-term monitoring program as described in the Performance Standard Verification Plan. The monitoring at Cooley’s Pond could be reduced if data indicates that surface water quality is not being affected by the contaminated groundwater (i.e., TCE concentrations remain at or below 5 µg/L and do not show an increasing trend). Also, fix well U6-030 and continue sampling to monitor plume stability.

Concur: Monitoring at the Cooley pond has been reduced from monthly to quarterly. If the current trend (<5 ppb) continues, the quarterly monitoring frequency will be adjusted accordingly. U6 –30 has recently been replaced. The new well will be included in future long-term monitoring rounds.

No action.

Evaluate long-term monitoring data to determine if the remedy is preventing plume migration, to determine the remedial progress, and to update the estimated remedial timeframe. The Performance Standard Verification Report should be conducted as scheduled in 2006.

Concur No action.

Evaluate the need for active treatment in the northern arm of the off-Base contamination plume, as required by the ROD.

Concur No action.

Continue operation and maintenance of the extraction and discharge components of the Craigdale PTS. Discontinue anti-scaling treatment in the off-line air stripper and bring extraction well U6-213 on-line as soon as possible (scheduled for Spring 2003).

Concur: Plans are in place to discontinue anti-scaling. Extraction Well U6-213 was brought back on line on 28 April 2003.

Well U6-213 was repaired after initial FYR document review. Recommendation was revised to reflect new information. Text was changed as follow: “Continue operation and maintenance of the extraction and discharge components of the Craigdale PTS. Discontinue anti-scaling treatment in the off-line air stripper. stripper and bring extraction well U6-213 on-line as soon as possible (scheduled for Spring 2003).”




Five Year Review Item Hill AFB Response URS Action Continue operation and maintenance of the on-Base pump and treat system. Evaluate the pumping strategy and, if necessary, upgrade the air stripper discharge pump so that the extraction system can be operated as designed (per the O&M Manual).

Concur with continuation of the on-Base pump and treat system. Do not concur with the recommendation to upgrade the air stripper discharge pump. Its capacity is 90 gpm. 40 gpm is the current actual discharge rate.

Text was revised as follows: “Evaluate the pumping strategy and, if necessary, upgrade the air stripper discharge pump so that the extraction system can be operated as designed (per the O&M Manual). Evaluate treatment system to determine why target groundwater levels at the extraction wells, an indication of plume capture, have not been achieved. System upgrades may be required or plume capture indicators may need to be updated in the O&M Manual.”

Develop a long-term maintenance strategy to closely monitor the bio-fouling problem at the extraction wells and to ensure that adequate treatment is implemented.

Concur: Extraction wells are chlorinated quarterly to prevent bio-fouling.

No action.

Continue all institutional controls. In addition, perform routine checks of locks, fences, and signs at wells and treatment facilities to prevent accidental exposure to contaminated water.

Concur No action.

Reevaluate indoor air data to determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas.

Concur. A plan is currently being prepared to sample air in homes above the OU 6 plume during the upcoming winter season (03-04).

Revised recommendation to include additional air sampling: “Reevaluate indoor air data, and if necessary obtain additional air samples, to determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas.”




Five Year Review Item Hill AFB Response URS Action Protectiveness Statement: Hill AFB concurs

that the remedies implemented at OU 6 are currently protective of human health and the environment in the short term. TCE concentrations generally are decreasing across the plume. However, in light of new direction and emphasis on the air exposure pathway, Hill will implement additional in-door air sampling during the upcoming winter season of 2003-04. If vapors are detected at levels above the new action limit, and are found to be originating from shallow groundwater contamination coming from Hill AFB, then steps will be taken to remove vapors from residences.

Evaluating indoor air quality was one of the recommendations but it was not mentioned in the Protective Statement. The Protectiveness Statement was revised to include the following: “Also, indoor air quality should be evaluated to determine if it has been adversely affected by the OU 6 groundwater plume. Remedial action should be implemented as necessary.”




Institutional Controls Section IX, Recommendation 1 – “Change the warning sign verbiage to provide a warning of the presence of contaminated soils that could pose a hazard if exposed.”

Do not concur. Current signage “Caution: Do Not Disturb Floor, Contact EMR, Phone 7-7890” is the language that was determined to be most appropriate by Bldg 225 managers, SGB management, EMR, and regulators.

Recommendation revised as follows: “When signs are replaced or additional signs are added, change wording to provide a warning of the presence of contaminated soils that could pose a hazard if exposed. For example: “Caution: Do not disturb floor or soil under floor. Disturbance could cause exposure to contaminated soils. Contact EMR, 7-7890”.”

Inspection and Maintenance Program Section IX, Recommendation 2 – “Remedy defects in floor slab as soon as they are identified to ensure minimal infiltration. Floor slab cracks are scheduled for repair during 2003.”

Concur No action.

Section IX, Recommendation 3 – “Replace tape, which outlines the areas of attainment, with paint or another method of delineation. The marking tape is scheduled to be replaced during 2003.”

Do not Concur. Painting the delineation lines has been tried previously and has performed more poorly than the current tape however, Hill AFB is not opposed to another method if it proves to be more successful.

Recommendation revised as follows: “Replace tape, which outlines the areas of attainment, with paint or another method of delineation. [The marking tape is scheduled for replacement during 2003.]”

Performance Monitoring Section IX, Recommendation 4 – “Review historical soil moisture data in an effort to ascertain the cause of the migration of hexavalent chromium above MCLs in the groundwater underlying the areas of attainment and the elevated concentrations of hexavalent chromium downgradient of the source area.”

Do not concur. Hexavalent chromium has been in the water table prior to the Remedial Investigation and was carried there as part of the initial release when the plating shop was active and discharging fluids to the corroded waste lines. When the plating area closed the fluids that acted as a carrier in the leaking pipes was eliminated and contamination could no longer reach the groundwater. Since the

Recommendation revised as follows: “Investigate source of elevated hexavalent chromium concentrations in the groundwater underlying the SS027 site. Investigate potential remedial options if necessary.”




Five Year Review Item Hill AFB Response URS Action Section IX, Recommendation 5 – “Once the source and fate of the migrating hexavalent chromium is identified, review potential remedial options.”

monitoring wells were installed and sampling began, the trends indicate decreasing hexavalent chrome concentrations that support the site conceptual model. In addition, an evaluation of soil moisture data performed by Hill AFB conclusively shows that soil moisture has not changed since the baseline soil moisture readings were collected. Please be aware that increases in soil moisture have to exceed the field capacity (fp) of a soil prior to transport occurring. Soil moistures at OU7 do not exceed 16% and that is in clay soils which are naturally going to be higher in soil moisture. Overall that data from this sites shows that the floor slab remedy is performing as expected and is effective.

Concur. Recommendation removed.

Section IX, Recommendation 6 – “Determine if a soil moisture probe is required in the middle chromium plating area of attainment.”

Do not concur. The only sources of water near the areas of attainment at OU7 were located to the north and south as stated above in comment 2. Because of the locations of potential water supplies it was determined by EMR and Regulatory agencies that neutron probes were only needed on the north and south attainment areas.

Information not previously available. Recommendation removed.

Section IX, Recommendation 7 – “Establish an appropriate action level for an increase in soil moisture content based on soil moisture results.”

Concur No action.

Section IX, Recommendation 8 – “Determine Concur No action.




Five Year Review Item Hill AFB Response URS Action what actions should be taken if an increase in soil moisture content occurs at a particular depth.” Section IX, Recommendation 9 – “Evaluate soil moisture logs along the length of the monitoring point, not just 7-8 feet bgs.”

Do not concur. The interval from 7 to 8 feet bgs was chosen as an evaluation point because it corresponds to the top of the clay layer that is found at all the areas of attainment and will be the first location where excess soil moisture will accumulate. However, hill AFB is also in accord with evaluating the data from all depths.

After discussions with EMR, recommendation revised as follows: “Annual reporting is inadequate to determine if neutron logging data are being compared to the previous logging event and the baseline log developed during initial installation of soil moisture probe locations. The annual report should be modified to capture current, historical, and baseline data for all intervals to ensure proper evaluation of these data.”

Section IX, Recommendation 10 – “Schedule soil moisture data collection in the same months of each year to ensure comparable results.”

Concur No action.

Section IX, Recommendation 11 – “Incorporate historical data from annual reports and current neutron logging data at all intervals into ERPIMS to ensure data availability for future comparisons.”

Concur No action.

General Section IX, Recommendation 12 – “Review the PSVP and ensure either the LTM or O&M contractor is addressing all aspects of monitoring and reporting.”

Concur. No action

Section IX, Recommendation 13 – “Re- Concur. Reference dose levels have changed, No action.




Five Year Review Item Hill AFB Response URS Action evaluate risk analysis due to change in hexavalent chromium reference dose levels.”

however the exposure pathway has not. A reinforced concrete floor prevents the exposure pathway being completed. If construction activities, requiring the concrete floor to be removed, were to occur at some point in the future then a revised risk analysis should be conducted to provide protectiveness to workers.

Protectiveness Statement: Hill AFB does not concur with the protectiveness statement. Hill AFB believes the remedy is protective. Soil moisture data indicate the continued transport of metals is unlikely beneath the slab because there is no more vertical migration of fluid to the water table. Monitoring data indicate that metals concentrations are decreasing suggesting that the source area is no longer impacting the shallow ground water.

Although the remedy is not protective of the environment, the elevated hexavalent chromium levels do not pose an unacceptable risk to human health or the environment. Based on the FYR guidance document, a “not protective” statement cannot be concluded without unacceptable risk. Since there are no receptors nor are there likely to be any receptors in the near future, the determination has been changed to protective. The Protectiveness Statement was revised as follows: “The remedy at OU 7 is protective of human health because there is no pathway for exposure. However, there is adverse impact to the environment based on concentrations that exceed MCLs in the groundwater directly below the Building 225 Chromium Spill site (Site SS027) and evidence of downgradient contamination. The actions outlined in the recommendations need to be addressed to ensure continued protectiveness, particularly identification of the source and fate of increasing hexavalent chromium concentrations in groundwater. Based on the




Five Year Review Item Hill AFB Response URS Action results of these investigations, potential remedial options should be identified.”




Section IX, Recommendation 1 – “Clarify appropriate COCs in the final ROD.”

Concur

No action.

Section IX, Recommendation 2 – “Investigate the following options: a. Reduce the frequency of sampling for the East system wells due to their historical contaminant concentration stability and low contaminant levels to ensure a cost effective sampling plan, b. Reduce the MDL with the laboratory to a reporting limit less than 5 µg/L for better quantification of contaminant concentration to support taking wells off-line, c. Take some or all of the East System wells off-line (U8-201, U8-207, U8-208) based statistically-proven concentrations below MCLs and modeling to ensure capture of the 5 µg/L contour is not compromised, and d. Change the discharge point of the East System from the sanitary sewer to the storm drain due to the low concentrations being captured by this section of the system.”

a. Do not concur. Quarterly sampling is conducted at eight extraction wells so that the mass of VOC removal can be calculated for annual Treatment System Operating Report b. Concur c. Do not Concur. Hill AFB recommends that U8-201 be shut down and the regulatory community be notified d. Concur

Recommendation revised as follows: “Investigate the following options: a. Reduce the cost of the sampling program by reducing the frequency of sampling for the East system wells if the change does not significantly impact the accuracy of the mass removal calculation.” b. No action. c. The Hill AFB response is in agreement with the DRAFT recommendation. Recommendation revised as follows: “In an effort to reduce system operating costs, take some or all of the East System wells off-line (U8-201, U8-207, U8-208) based on statistically-proven concentrations below MCLs and modeling to ensure that capture of the 5 µg/L contour is not compromised, and” d. No action.

Section IX, Recommendation 3 – “Calculate maximum shutdown durations for each well within the IRA system to ensure future capture of the entire plume transect. Compare the maximum well shutdown durations for each well to determine the maximum system shutdown duration.”

Concur No action.



5YR response OU 8 URS2 2 of 2

Five Year Review Item Hill AFB Response URS Action Section IX, Recommendation 4 – “Address operational issues: a. Replacement pump purchases should be based on actual flows and not modeled projections, as the currently installed pumps fail. b. Clean and maintain spare pumps. c. Complete a cost-benefit analysis for replacement or re-engineering of the current pressure transmitter enclosures.”

a. Do not concur. Current practice is to purchase new pumps of a size commensurate with actual flows. During the next revision of the O&M plan, the pump specifications based on predicted flows will be replaced by the pump specifications for actual flows. There is no electromechanical evidence in broken pumps to suggest that a pump sizing has caused the failure. b. Concur c. Concur

a. Recommendation revised as follows: “a. During the next revision of the O&M Plan, the pump specifications based on predicted flows should be replaced by pump specifications based on actual flows.” b. No action. c. No action.

Section IX, Recommendation 5 – “Review previous indoor air results to ensure future residents' health based on the new criteria of 0.43 ppbv of TCE.”

Concur. Plans are being made to implement additional air sampling during winter 03-04 to assess this issue

Recommendation revised as follows: “Re-evaluate indoor air data, and if necessary obtain additional air samples, to determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas.”

Section IX, Recommendation 6 – “Perform additional sampling at U3-610 to develop a representation of the current exposure risks at this location.”

Do not concur. The surface sampling point in question is U3-633 not U3-610. U3-610 is covered by a metal grating and physical contact with the water is not possible. U3-633 is a field drain on private property. It was last sampled in April 2003 and analytical results are pending.

[The April 2003 sampling event results were published after the review period for this FYR (through Sep 2002).] Recommendation revised as follows: “Review analytical sampling results for U3-633 to quantify exposure risks at this location. Continue sampling at this location to develop a statistically relevant representation of the exposure risks.”


No action.



Five Year Review Item Hill AFB Response URS Action IX Recommendations and Follow-up Actions for OU 9

No comments. The recommendations and follow-up actions are acceptable and accurate.

No action.



Five Year Review Item Hill AFB Response URS Action IX Recommendations and Follow-up Actions for OU 10

It is recommended that a follow-up action to conduct indoor air sampling be added to the list.

Recommendation added as follows: “Conduct air sampling in off-Base residences to determine if the new action level for TCE (0.43 ppbv) in indoor air warrants mitigation measures in off-Base residential areas.”



Five Year Review for Operable Unit 11

Five Year Review Item Hill AFB Response URS Action Section IX, Recommendation 1 – “Perform a comprehensive groundwater characterization for contaminants of concern in the groundwater. Compile characterization information in the RI report and generate FS.”

Concur. No action.

Section IX, Recommendation 2 – “Select and implement a remedy, if required, in accordance with CERCLA criteria.”

Concur No action.


No action.



Five Year Review for Operable Unit 12

Five Year Review Item Hill AFB Response URS Action General Item – Reference to “Roy Plume” The City of Roy has asked that the OU12

plume NOT be referred to as the “Roy Plume”. All references to the “Roy Plume” should be replaced with “OU12 plume” in the document.

All references to the “Roy Plume” were replaced with “OU 12 plume”.

Section IX, Recommendation 1 – “Delineate and remove the source area.”

Concur. Investigation work is continuing to delineate the OU12 source zone.

No Action.

Section IX, Recommendation 2 – “Continue with installation of the Base Boundary Hydraulic Containment Treatability Study System, as it should allow for continuing work to remove and investigate the source area without concern of contaminant migration off-Base.”

Concur. This system has been installed and became operational in April 2003.

No Action.

Section IX, Recommendation 3 – “Consider the possibility of an early action to address the area of the plume off-Base where basements are being affected.”

Concur. Hill AFB is currently developing a plan to install a system in the western portion of the OU12 plume.

No Action.

Section IX, Recommendation 4 – “Determine areas of potential risk for indoor air contamination and develop a sampling plan to catch and address any contamination early.”

Concur. Because not every home over the plume shows indoor air contamination, Hill AFB is working to identify factors that control the movement of TCE-contaminated vapors into homes. Identification of these factors should increase our ability to determine areas of potential risk.

No Action.




Five Year Review Item Hill AFB Response URS Action Section IX, Recommendation 5 – “Institute a sampling plan for the location off-Base where groundwater surfaces to identify any contamination, if it exists, as early as possible.”

Concur. Sampling of the surface water discharge and land drain discharge at OU12 is already being performed and has previously been performed.

No Action.

Protectiveness Statement: Hill AFB concurs with the protectiveness statement for OU12. However, the statement that “Remedial measures to protect human health will be addressed after completion of the RI/FS and ROD and are scheduled to be in place by 2007” is somewhat misleading. Hill AFB has installed vapor removal systems in several residences where TCE concentrations have been found to exceed human-health based screening values. Hill AFB will continue to immediately address any instances where exposure pathways are complete and concentrations are above human-health based risk standards. Hill AFB has installed vapor removal systems in several residences where TCE concentrations have been found to exceed human-health based screening values and will continue to address such cases as they are identified.

Protectiveness Statement revised as follows: “Remedial measures to protect human health for the contaminated groundwater will be addressed after completion of the RI/FS and ROD and are scheduled to be in place by 2007. Although……concern. Hill AFB has installed vapor removal systems in several residences where TCE concentrations have been found to exceed human-health based screening levels and will continue to address such cases as they are identified.”

Appendix A.2

Restoration Advisory Board Comments on May DRAFT of Five-Year Review Report

Table A.2

URS Response to comments by Al Herring (RAB) and EMR to 5/2 DRAFT

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action General Comments

1 This is a valuable document which I feel is well worth the effort and expense involved. I learned much by reading the draft, and I would guess that EMR personnel also gained some new insights.

JWW: Noted. No action.

2 The figures are especially valuable. I consider them so important, in fact, that I recommend that consideration be given using the site figures as the first page for each OU section. The careful thought given to their content is appreciated.

JWW: OK to place OU figures at the beginning of the main OU text or leave them in their current position.

No action.

3 The FYR is very repetitive. Using OU2 as an example, recommendations are repeated three times (once in the OU text, once in the Base response, and again in the IRP WP007 section.) I would estimate that at least 50% of the IRP WP007 section is a word-for-word repeat of text in the OU2 discussion. The reader, especially if uninitiated, is probably left wondering, “Why are they driving me crazy with this repetition?” In this regard I have several suggestions:

No EMR response provided. No action.

3a First, it is unclear to me if the Base response for each OU is intended for inclusion in the final document, or if they were provided just to help (or bias) the reviewers at this stage. (I personally found them to be helpful and thought that the repetition even gave a useful emphasis.) However, if Base comments are intended for inclusion in the final document, it would be a simple thing to insert them in brackets following each recommendation in the text of each Section IX. For example, (from OU2): “1. Jointly evaluate the effectiveness of the SRS and the containment wall. [Concur. Work related to this recommendation is planned for this year.]” On the other hand, if the decision is to include Base comments and keep the present format, it would be nice to at least dignify them with page numbers. (I note that Base comments were sometimes counted in the pagination sequences and sometimes not. Consistency is needed.) Of course, if they are not intended for inclusion, this is all moot.

JWW: Noted. All comments and resolution on the 2/ May DRAFT included in Appendix A. Hill EMR comments are A.1, RAB comments are A.2, and Hill EMR Comments on Preliminary versions are A.3.

Table A.2

URS Response to comments by Al Herring (RAB) and EMR to 5/2 DRAFT (Continued)

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action 3b My preference would be to append all IRP sections. (I

realize that the OU discussions were built from the IRP sections and that the IRP sections do contain some potentially valuable details. However, I think few people are going to read them.) Appending them would give separation and reduce the impression of endless repetition. However, if the decision is to stick with the present format, it would be nice to at least warn the reader in the Introduction that large sections in the OU discussions will be repeated verbatim in the IRP sections. Perhaps a paragraph on “How to Read This Document” would be appropriate. And if the decision is made to leave the IRP sections in the body of the report, start them just below the Section XIII headings instead of having them “attached.” (This would save about 12 pages.)

JWW: Recall we were going to append the site chronologies and site summaries. If URS chooses to remain with this structure, I recommend that URS adopt the AH suggestion alerting readers early in the report of the report structure to avoid reading redundant text.

Concur. Text modified to present the structure of the report to the reader in both Section VII and in Section XIII of each OU Summary.

4 I note that the Base, EPA, and the State agreed on a new and lower action level for TCE in indoor air which may affective protectiveness determinations in many of the IRPs. This got me thinking about 1,2-DCA, which is even more easily transported and has (I gather) about the same toxicity. Does the 1,2-DCA action level for indoor air need to be re-evaluated?

JWW: Recommend that you contact Steve Hicken for further guidance on indoor air issues.

No action. Action levels for VOCs are being evaluated by UDEQ, EPA, and Hill AFB. This issue should be addressed in the 2008 FYR.

Specific Comments List of Acronyms Some acronyms used in the text are not included. Those I

noted as missing were IRA, PAH, and SW. JWW: Noted. Concur. List updated.

Executive Summary a) To say the review “was intended to: 1) confirm that the

remedy is operating as designed” strikes me as inappropriate. Someone could even construe the statement to indicate bias on the part of the reviewer. It is also inconsistent with the more appropriate statement given shortly afterward: “Is the remedy functioning as intended by the decision document?” The second paragraph strikes me as just a clumsy rewording of the “three questions” listed in the third paragraph. This part of the Executive Summary should be rewritten to improve clarity and eliminate repetition.

JWW: Concurs with AH suggestions in (a) and (b).

Concur. Text modified to replace “confirm” with “evaluate whether”..

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action b) The table lists two determinations as “Not protective” and

ends there without further comment. If I were an executive reading this Executive Summary, I would sure want to know more about the “Not protective” sites and the implications of the findings. (For example, is there an eminent danger to public health? Am I at risk of going to jail?) To not provide a brief discussion of the “Not protective” findings means that the executive has to go digging for the answer to his or her perhaps most important question.

JWW: Concurs with AH suggestions in (a) and (b).

Concur. Text modified.

Introduction a) It again bothers me that the review is intended (third

paragraph) to “confirm that the remedy is operating as designed.” Surely the intent is to “evaluate whether the remedy is operating as designed.”

No EMR response provided. Concur. Text modified.

b) It strikes me that there should be early mention of which OU’s have ROD’s and which do not, and how this affects the FYR review. This could be done in the Introduction or possibly in the Description of Process, but listing them first in III-3 is too late and too hidden.

JWW: In (b) AH is referring to text in the 3rd paragraph, page III-3.

Concur. Introduction text modified.

c) In Table 2, it would be nice to flatter the Restoration Advisory Board by listing its formation in 1995.

No EMR response provided. Concur. Table modified.

Description of Process

Fourth paragraph on II-1, I would like to see the first sentence read, “Members of the Restoration Advisory Board (RAB), a group of local people representing the surrounding communities and interest groups, . . .” (Several of us do not represent communities.)

JWW: Concur. Concur. Text modified.

Conclusions and Recommendations a) This section begins with a paragraph titled, “Five-Year

Review Process.” This is not a conclusion or recommendation. The prior section was the “Description of Process” and if this first paragraph contains anything significant which is not already covered in that section, it should be added there rather than left to clutter up Conclusions and Recommendations.

No EMR response provided. This is the introduction for the section and includes the conclusion that the process was successful. The heading was removed.

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action b) In general, this section strikes me as long on discussing

processes and short on any meaningful discussion or conclusions about protectiveness. Again, if I am the person who got concerned about two IRP’s being “not protective” while reading the Executive Summary, I would hope to find some more detail concerning those determinations and whether there is any imminent hazard to human health. I suggest that URS rewrite this section with a critical eye given to the recommendations and conclusions that need special emphasis.

JWW: (b) Concurs. Section III provides a list of the issues and recommendations that are emphasized from all those mentioned in the OU and Site Summaries. Section IV discusses Protectiveness. Text in Section IV was modified to discuss the OU that is not protective.

References (Tab VI)

References for what? These four little references hardly seem worthy of a major section and two pages of basically blank paper. Why not just list them somewhere within the Description of Process section?

JWW: Suggest combining references with those cited in Appendix C. See Response #19 below.

Separate reference lists are for specific sections of the FYR Report. App. C. includes all documents reviewed for the 2003 FYR, not just those called-out in the text. Reference list titles were modified to clarify.

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action OU 1 In the Background section, I see no mention of a possible

source for arsenic contamination. However, on page OU 1-2, the statement is made that “Sediments from spring areas with arsenic contamination above 11 mg/kg will be identified and excavated after the springs have ceased to flow.” Furthermore, for WP005 (Berman Pond in OU3) the cleanup level required for arsenic in soil is listed at 4.1 mg/kg. Three questions: (1) Are the elevated arsenic levels found in OU 1 spring sediments possibly natural? (2) Why the difference in cleanup targets? (3) Why is arsenic soil contamination not mentioned in lists of Contaminants of Concern for any of the OU 1 IRP’s?

JWW: Noted. It is likely that Arsenic is natural in the soil. The release of various organic compounds is thought to have mobilized it. KG: 1) concur with Jeff’s response; 2) both of the cleanup targets are based on determination of the “background” concentration of arsenic in the soil. Background is determined by collection and analysis of samples from outside the area of known contamination. The background level for OU3 was determined to be the upper 95% confidence limit from 14 samples collected from OU3 and OU7. The background level for OU1 was based on the results of 26 samples collected and analyzed from OU1, OU2, and OU4. The background level was determined to be the maximum measured arsenic concentration (2 samples had 11 mg/kg); 3)?

1) The concentrations in the soil at OU 3 are within background concentrations; 2) Concur with K. Gorder’s comments; 3) Arsenic is not an indicator chemical for carcinogenic/noncarcinogenic effects for soil since the concentrations at the time of the RI were within background levels (1.2-22 mg/kg, maximum of 10 mg/kg). However, arsenic was detected in the groundwater and surface water at a maximum of 1,160 ug/L. This is because conditions in the groundwater at OU 1 are reducing. Chemically reducing conditions (low dissolved oxygen, low redox potential) in OU 1 ground water influences concentrations of some constituents, particularly iron, arsenic, and organic compounds such as TCE, PCE, and vinyl chloride. Text Modified.

OU 2 On page OU 2-5, the statement is made that “The baseline risk assessment considered the inhalation of indoor air in conjunction with showering as a potentially significant current and future pathway for both onsite and offsite residential exposure.” This implies that potable water in this area is contaminated with TCE, a possibility that is surely deserving of comment.

JWW: Noted. Suggest clarification or further comment. The 1992 BRA may have considered showering with water obtained from local, shallow contaminated groundwater sources.


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Comment I.D. Al Herring Comment EMR Review/Direction URS Action OU 2 KG: Upon further review of the 1992

BRA, I disagree with the FYR section in question. The BRA did not consider inhalation during showering as a completed exposure pathway for the current scenario (was considered a potential future). Page 3-2 indicates that existing shallow potable water wells are (were?) located downgradient of the OU2 plume. However, the exposure assessment on page 3-25 has inhalation during shower crossed out with the explanation that “Currently, all residences use municipal water supply”. The BRA did (crudely by today’s standards) attempt to quantify the risk from ambient air and recognized the potential for indoor air contamination. Suggest adding this clarification to the response to comments and changing the text to read “…considered the inhalation of ambient and indoor air as a potentially significant current and future pathway for both onsite and offsite residential exposure.” May want to add statement that calculated risk did not indicate that immediate action was required (?)

OU 3 a) In Background, it would be nice to give some indication of

what the contaminants of concern are for Berman Pond. The fourth sentence would be smoother if it began, “Performance indicators for these two sites include. . . .”

JWW: (a) Noted. Concur. Text modified.

b) In answering the three questions (pages OU 3-4 and 5) the writer departs from the format followed for all other OU’s in the FYR by not giving a simple “Yes” or “No” answer before expanding on the reason.

JWW: (b) Noted. Suggest URS maintain consistency in format.


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Comment I.D. Al Herring Comment EMR Review/Direction URS Action c) On page OU 3-4, the first sentence for ST004 would be

more straight forward if it began, “Performance indices include significant increases in groundwater pH or in concentrations of TDS, sodium, arsenic, or selenium downgradient. . . . “

JWW: (c) Noted. Concur. Text modified.

d) More importantly, the writer notes (page OU 3-4) that “Groundwater levels at the extraction sumps at Berman Pond show that the elevations are approximately 10 feet above the action level prescribed in the PSVP and have been since 1998. Pumps have not been installed in the groundwater extraction sumps, as prescribed in the ROD.” However, in Table OU 3-3, the answer to the question “Is the remedy function as intended by the decision documents?” is given as “Yes”! Surely the answer must be “No.” (EMR staff may believe the perched contaminated groundwater is being captured by the OU 8 interim wells, but the fact seems to remain that the groundwater levels at Berman Pond are 10 feet above the action level.)

JWW: (d) Noted, URS reasoning seems adequate.

No action.

e) In the Issues section (page OU 3-5) the statement is made for Berman Pond that “When the perched groundwater elevations exceed the action level, pumps should be installed and a pumping strategy, sampling and analysis plan, and continued groundwater lever monitoring should be implemented.” Then the writer seems to contradict him or herself in the Recommendations section (page OU 3-6) by saying “The PSVP should be revised to document the change of remedial actions at the site. . . .” Which is it to be? (I would favor addressing the problem as prescribed in the ROD, rather than changing the paperwork.)

JWW: (e) Noted, perhaps insert text, “The ROD states that when the perched GW elevations….”


f) It is not obvious to me why Contaminants of Concern for ST004 are given as “NA,” whereas there is a long list for WP005.

JWW: (f) Noted. No action. There is no chemical contaminant of concern at ST004. The condition requiring action is pH.

g) On page 1 of 5 for WP005, I think “1WTP” should be “IWTP.”

JWW: (g) Concur. Concur. Text modified.

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action h) On page 3 of 5 for WP005, Question B, the ingestion and

inhalation CSF’s for PCB-1254 look scrambled. More importantly, why are they even being discussed since PCB is not listed as a Contaminant of Concern for this IRP?

JWW: (h) Noted, AH is referring to the Site Summary for WP005.

Concur. Text modified to clarify unit. PCB-1254 is listed as a COC for WP005.

OU 4 In the second paragraph (page OU 4-1), it sounds funny to say that an area of high TCE concentration “was recently discovered in the vicinity [of] well U4-080 in 1996.”

JWW: Noted. Concur. Text modified.

OU 6 The classification of “Protective in the short-term” for OT026 (page 6 of 7) strikes me as inconsistent and far too optimistic considering the Technical Assessment observation on page OU 6-4 that “Several of the indoor air results from the original RI were above this new [TCE] action level, creating the potential for air quality issues that have not been addressed,” and the Recommendation made on page OU 6-5 to “Re-evaluate indoor air data to determine if the new action level for TCE (0.43 ppbv) in indoor air would warrant additional mitigation measures in off-Base residential areas.” The OU 6 protectiveness classification of “Protective in the short-term” also strikes me as inconsistent with the classification made for WP002 in OU 1 (on page 9 of 9 for WP002) which was, “Protectiveness cannot be determined until further information is obtained.” As noted under Issues (page 8 of 9), “some of the indoor air sampling results, collected during the RI, exceed the new action level for TCE in indoor air (0.43 ppbv),” and a recommenddation was made to “Reevaluate the RI data on indoor air and determine if the new action level for TCE (0.43 ppbv) in indoor air warrants additional mitigation measures in off-Base residential areas.” Thus, we have two separate IRP’s which had TCE levels in indoor air samples above the new action level, but the protectiveness classifications and statements are quite different. I feel strongly that the protectiveness classify-cation for OT026 should also be “Protectiveness cannot be determined until further information is obtained.”

JWW: Concur. Concur. Text modified.

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action OU 7

a) On page OU 7-3, the statement is made that “The reference dose for hexavalent chromium has changed from 5E-3 to 3E-5 in soil (100 times more stringent). . ,” and this statement is repeated on page 3 of 3 in Appendix E. However, I interpret this to mean that the standard has changed from 1/(5)(5)(5) to 1/(3)(3)(3)(3)(3), or 1/125 to 1/243. This is approximately two times as stringent, not 100 times.

JWW: (a) Noted. 5E-3 is engineering notation for 5 X 10-3 or 0.005. Text modified so that numbers greater than 10-4 are written out and smaller numbers are written in engineering notation. Engineering notation is explained in the List of Acronymns.

b) I agree with Base EMR personnel that the designation of “Not protective” for SS027 seems too harsh. I note on page 5 of 5 that the Protectiveness Statement says “There are no current human health risks at this site because the areas of contamination are beneath the concrete floor slab prevent the completion of an exposure pathway. However, due to the apparent migration of contamination of above MCLs from the source area to surrounding soil and groundwater, this remedy is not protective of the environment.” Speaking as the Sierra Club representative on the RAB and as a person who is highly concerned about protecting the environment, I have no idea of what if any threat hexavalent chromium in the area of SS027 poses to the environment, nor does the author offer any explanation. I would also contrast the concerns expressed for migrating chromium at SS027 with the statement made on page OU 8-2: “Reduction of hexavalent chromium to immobile trivalent forms occurs in subsurface environments and may be sufficient to mitigate its transport.”

JWW: (b) Noted. Concur. Text modified.

c) For the Base response to Recommendation 9, hill needs to be capitalized.

JWW: (c) Noted. No action.

OU 8 a) In the Introduction, it needs to be stated that OU 8 does not

yet have a ROD. The Introduction for OU 5 handled this situation nicely and could be used as a model.

JWW: (a) Noted. Concur. Text modified.

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Comment I.D. Al Herring Comment EMR Review/Direction URS Action b) Layton may not be as sensitive as Roy, but I think there

could be a better name for this plume. In addition, I think it is somewhat misleading to call it a “TCE plume” since 1,2-DCA may ultimately turn out to be the bigger issue. How about calling it something like the “South TCE/DCA Plume”?

JWW: (b) Noted. No action.

c) On page OU 8, the term “abiotic” degradation is used. My dictionary and I are not familiar with “abiotic” and it would be helpful if there were a brief explanation.

JWW: (c) suggest “abiotic” be defined to mean any transformation not mediated by biotic agents.


d) The argument on well pumps being oversized seems a bit specious. If the pump capacities were based on needed flows (from the model) but actual flows are less, it seems to me that the recommendation should be to get flows up to design (through actions such as cleaning screens, “fracing” wells, or acid cleaning) rather than replacing with smaller pumps.

JWW: (d) suggest clarification. Text modified to suggest that pump specifications be based on actual flows instead of predicted flows.

OU 9 a) Introduction needs to state that OU 9 has no ROD. JWW: Noted. Concur. Text modified.

b) Background needs to give some background on SD034. For example, what are the primary contaminants of concern? (Right now these are buried on page OU 9-15.)

JWW: Noted. Concur. Text modified to direct reader to the CoCs in the Site Summary.

OU 10 Clarify in Introduction that there is no ROD for this unit. JWW: Noted. No action.

OU 11 a) Clarify in Introduction that there is no ROD for this unit. JWW: Noted.

SR: I reviewed Al's comments on OU11 and concur with them.


b) In line four of the Introduction, it should be “benzene, toluene, ethylbenzene, and xylenes (BTEX)”


c) In second paragraph of Background, use of “ethyl [sic]” is awkward. Why not call it the “Ethyl” tank? Otherwise the reader is left wondering why the writer wanted to sic it.


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Comment I.D. Al Herring Comment EMR Review/Direction URS Action OU 12 Clarify in Introduction that there is no ROD for this unit. JWW: Noted. Concur. Text modified.

Appendix A Interesting, but I see no reason to include it in the final draft.

JWW: Concur All comments and resolution on the 2/ May DRAFT included in Appendix A. Hill EMR comments are A.1, RAB comments are A.2, and Hill EMR Comments on Preliminary versions are A.3.

Appendix C Aren’t the “Documents Reviewed for Hill AFB 2003 Five-Year Review” just a re-listing of the documents given in Section VII for each of the OU’s? If so, I would say delete this section. (Why be repetitive?) Similarly, the list of Personal Communications could be easily moved to the Description of Process Section (if it is needed at all), thus eliminating the whole appendix.

JWW: Concur, see Response #6 above. Perhaps general references could be included in Reference tab (VI) and OU-specific references can be included in the main OU summaries. Concur with AH for Personal Communications.

Separate reference lists are for specific sections of the FYR Report. App. C. includes all documents reviewed for the 2003 FYR as well as all personal communications, not just those called-out in the text. Reference list titles were modified to clarify.

Appendix A.3

UDEQ Comments on May DRAFT of Five-Year Review Report

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Comment I.D. Regulator Comment EMR Review/Direction URS Action General Comments

1 The draft report evaluates changes in the chemical-specific ARARs that have occurred since the last 5-year review, but does not attempt to assess the impact of revisions to the action- and location-specific ARARs. The Comprehensive Five-Year Review Guidance (Section 4.2.1) indicates that revisions to all types of ARARs should be evaluated.) A number of rule changes have occurred in the last several years. Some of these are mentioned below:

Attended conference call. Comment #1 was the subject of a conference call including UDEQ, USEPA, Hill EMR, and URS on Monday, 30 June 2003 at 1:00 p.m. During the call, UDEQ indicated that the 4th item (1-d, re: CAMUs) was the only 1 of the 4 that should be specifically addressed in the FYR Report as there are CAMUs (under ARARs) at OUs 1 and 2. The other items were resolved in the discussion as described for each in this matrix. The text was modified to clarify that the appropriate action- and location-specific ARARs were reviewed for this 2003 FYR.

1-a The Drinking Water rules (UAC R309) have been revised and renumbered recently. Changes to the chemical-specific standards in these rules have already been addressed in the draft report.

No EMR response or direction. No action. Per 30 June 2003 call: Drinking Water rules were addressed in chemical-specific standards.

1-b The Air Quality standards (UACR307) were revised. The revised rule provides de minimis emissions standards (UAC R307-413-8) for air strippers and soil venting projects. Where de minimis emissions are exceeded, compliance with UAC R307-410 (emission impact analysis) and UAC R307-401-6 (conditions for issuing approval orders) is required, including implementation of best available control technology (BACT). The change in the rule may not impact Hill AFB significantly, however, because Hill AFB RODs have generally required implementation of BACT whenever emissions were anticipated.

No EMR response or direction. No action. Air Quality standards were addressed in RODs, which have required implementation of BACT (best available control technology) for emissions from air strippers at Hill AFB.

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1-c The fugitive emissions and fugitive dust requirements for Davis County (UAC R317-309) were revised, including the opacity limits. For sites where construction is complete, the changes in the rule are not likely to affect the protectiveness of the remedy, unless additional dust-generating activities occur.

No EMR response or direction. No action. Changes to fugitive dust emissions regulations are not likely to affect protectiveness because construction is complete for all remedial actions that underwent the 2003 FYR process.

1-d The corrective action management unit (CAMU) requirements under 40 CFR 264 Subpart S and UAC R315-8-21 were also revised. The waste management requirements of the new rule are somewhat more stringent than those in the old rule. The new rule (40 CFR 264.550) allows CAMUs that existed at the time the rule was promulgated, and those where applications were substantially complete, to be considered grandfathered CAMUs. Grandfathered CAMUs are subject to the requirements of 40 CFR 264.551, and the waste, activities and design must remain within the general scope of the CAMU as approved. Where CAMUs have been designated within operable units at Hill AFB, compliance with the substantive requirements for grandfathered units should be verified.

No EMR response or direction. Compliance with the requirements for grandfathered CAMUs was verified and documented. In accordance with the EPA 2002 final CAMU rule, for a CAMU to be grandfathered, no changes can be made to the scope of the original approval of the CAMUs for OU 1 and OU 2. Based on this 2003 FYR, no changes to the scope of the CAMUs for OU 1 and OU 2 have been made. As such, the action of creating a CAMU in accordance with the original 1993 rule still complies with the more current, 2002 final rule. The text was modified to explain the CAMUs designated for OU 1 and OU 2 still comply with action-specific ARARs.

2 First Five Year Review was conducted in September 1998 and the second one is being conducted in 2003. This should be reflected in site chronology for each operable unit. Please see specific comments below.

Edit. No action. The chronology for the Base (Table 2) was modified to include the first Five-Year Review. Because this event occurred at a Basewide level, it was not repeated in the chronologies for each OU.

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3 It appears that some of the recommendations for each IRP site are not being incorporated into the operable units recommendations. Please ensure that the site specific recommendations are incorporated into the recommendations for operable units.

Edit. Text modified. The hierarchal structure of the report, which condenses the Basewide summary from the OU summaries, and the OU summaries from the IRP site summaries, incorporates only the most important recommendations at each level. Additional explanation of this structure was added to page II-8 and the beginning of each OU summary to assist the reader.

4 It is our expectation that after the five-year review is finalized that Hill Air Force will develop a work plan for implementing the recommendations of this review.

EMR agrees. No action required in FYR Report.

5 Five-Year Review Summary Form: The review period needs to be provided.

Edit. No action. The FYR Summary form, located prior to the Executive Summary, specifies that the review period extends through September 2002. The start date was not specified because this FYR includes some information concerning IRP site and OUs prior to 1998 that were not included in the first FYR in 1998.

6 Page ES-1, second paragraph, second sentence: The second sentence may be re-written as follows: The review was intended to: 1) confirm if the remedy is operating as designed. The same comment also applies to page 1-1, fifth paragraph, second sentence. Please make this correction throughout the document.

Edit. Concur. Previously implemented.

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7 The last paragraph indicates that sites with NFRAP status as well as sites where a remedy has not been installed were given a “not applicable” determination in the summary of protectiveness. Some clarification on this issue is needed. The term “No Further Remedial Action planned” could imply to some readers that a remedial action has been conducted that might be subject to a five-year review.

Edit. Concur. Text revised to clarify.

8 Page 1-6, Table 2: First five-year review was conducted in 1998 and the second one is being conducted in 2003. This should be noted in the Table 2.

Edit. Refer to Comment #2.

9 Page II-2, Table 3, Document Review: For the Record of Decision and Action Memorandum entries, the Table should list ARARs as contents applicable to the five-year review.

Edit. Concur. Table revised.

10 Page II-3, Table 4: The third line has a typographical error and should be corrected as follows: Background, nature and extent of contamination.


11 Page II-3, Table 4: The line below Table 4 should also be re-written as follows. A list of all documents that were reviewed for this Five-Year Review is included in Appendix C.


12 Page III-2, Table 7: The footnotes for “+” and “_” need to be clarified. According to the footnote the “_” sign means that 2002 MCLs are less stringent and the “+” sign means that MCLs are more stringent. This is not correct since a number of signs in the Table have been used for contaminants that do not have MCLs (boron, methylene chloride and naphthalene) and contaminants where the MCL has not changed (trichloroethene and perchloroethene).

Edit. Concur. The footnotes were modified to read as “2002 MCL or risk factors are less stringent”, etc. Changes to the MCLs of the contaminants in question (if available) did not occur, but the associated risk factors changed.

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13 Page III-2, Site Management, First Paragraph: The second sentence refers to a site management plan that could be conceptual or a published document. Is there a published document that could be referenced here?

Edit. Text modified. The sentence is intended to introduce the concept of a site management plan. Text revised to clarify.

14 Page III-4, Optimizing Long term Operations, Second Paragraph: The text indicates that following a review and acceptance of an application for an innovative technology project, the ITP manager works directly with the OU project manager to coordinate the activities and communicate findings to other OU managers. Please note that EPA and UDEQ need to be involved in decisions regarding innovative technology projects as well.


15 Page III-4, Optimizing Long term Operations, Second Paragraph: If the implementation of an innovative technology significantly changes an existing remedy, an explanation of significant difference or ROD amendment must be done.


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16 Page III-5, Basewide Recommendations: The second bullet states: “re-evaluate the risk analysis for OU1 through OU8.” Please note that while operable units 8 and 5 have undergone interim actions, the risk assessments for these operable units were updated in 2002 and 2003 respectively as part of the remedial investigation process. It is not clear whether the author of Five-Year Review meant that these latest risk assessments also needed to be updated? The risk assessment for OU5 is still in a Draft stage. Should it be reviewed and revised before it becomes final?

No EMR response or direction. No action. For OU 5, the Draft Remedial Investigation Report, containing the risk assessment, was published in March 2003, therefore it was not reviewed for this FYR (review period only through September 2002). However, the risk assessment should have been developed based on the most current standards. The assumptions used should be reviewed in the 2008 FYR. For OU 8, the risk assessment was also conducted as part of the RI, published in Dec 2001. This FYR was based on the Interim ROD published in 1997. No new remediation goals have been developed since the 1997 Interim ROD. The assumptions in the 2001 risk assessment should be reviewed before remediation goals are developed for the final OU 8 ROD.

17 Hill Air Force Base Response to Five-year Review for Operable Unit1: Please number this Table next to page OU1-11 and all its pages. Recommendation # 7 [for OU 1] deals with the future indoor air sampling in the residential areas because of the new action level fro TCE (0.43 ppbv) that has been established. While it may be a good idea, please note that the off-site plume at OU 1 primarily consists of a cis-1,2 DCE plume where the action level has not changed.

Edit. Hill AFB has plans in place to sample indoor air in residential areas associated with OU 1 fall/winter 2003. Samples will be analyzed for all plume volatile species including cis-1,2 DCE.

The Hill AFB EMR Response to the May DRAFT is included in Appendix A. The comment resolutions were incorporated into the text of the June DRAFT of the FYR Report.

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18 Operable Unit1: Some of the recommendations from IRP sites e.g., adding chromium to the sampling and analysis plan for springs at OU1 are not being captured in the recommendations for the entire OU. Please make sure that recommendations for operable unit include all the recommendations from IRP sites.

Edit. Do not concur. Refer to Comment #3.

19 Table OU1-2:Site Chronology – Hill Air Force Base 2003 Five Year Review: First Five Year Review was conducted in 1998 and the second one is being conducted in 2003. This should be reflected in the Table OU1-2.


20 Hill Air Force Base Response to Five Year Review for Operable Unit 2: Please number this Table next to page OU2-9 and its pages.


21 Table OU2-2:Site Chronology – Hill Air Force Base 2003 Five Year Review: First Five Year Review was conducted in 1998 and the second one is being conducted in 2003. This should be reflected in the Table OU2-2.


22 Page OU3-1, Introduction: It may be stated in the introduction that ground water contamination from OU3 sources is being addressed in OU8.

Edit. Concur. Text revised to clarify.

23 Page 3-1, Table 3-1: Some sites e.g., Building 511 (RVMF) were initially part of OU3 but later excluded from further consideration (in the Record of Decision). This site is not part of this Five Year Review. However, golf course and perimeter road, with similar history, are included in the Five Year Review for OU1 and OU2, respectively. This discrepancy should be resolved.

No EMR response or direction. The introduction of the ST018 site summary was modified to explain that IRP site ST018 included both Buildings 511 and 514 (RVMF), but that contamination at Bldg 511 was within acceptable limits.

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24 Page 3-1, Table 3-1: The ROD states that Ponds 1 and 3 are part of OU3. However, Table 3-1 lists Pond 2 as part of OU3. Please clarify.

No EMR response or direction. The background section of the OU 3 summary explains the transfer of Ponds 1 and 3 from OU 3 to OU 9 after the OU 3 ROD. The dates of these site transfers have been added to the OU 3 chronology (Table OU3-2). Pond 2 is in OU 3.

25 Page 3-2, ST004 – Sodium Hydroxide Tank Site: Please explain what is meant by “temporary cap”. Is the cap temporary or is it permanent?

The OU3 NaOH Tank site is a permanent asphalt cap.

Concur. The text in the OU Summary and the Site Summary was modified to clarify that the cap is not temporary.

26 Hill Air Force Base Response to Five Year Review for Operable Unit 3: Please number this Table and its pages.

No EMR response or direction. Do not concur. Refer to Comment #17.

27 Page 3-11, Table 3-2: The dates of First and Second Five Year Reviews should be included in this Table.


28 Page 4-3, Section V, Progress Since Last Five Year Review: The first bullet mentions the proposed explanation of significant difference (1995). This ESD was drafted prior to the Five year Review. Please make this correction.

Edit. Concur. The reference to the ESD was removed from this section and added to the “Landfill Contents Remedy” paragraph of the Remedial Actions section.

29 Page 4-3, Section V, Progress Since Last Five Year Review: An ESD or ROD amendment for OU4 is still needed to document the changes in the remedy outlined in the ROD. For example the SVE is not being used and the ground water is being discharged directly into sanitary sewer bypassing the treatment plant (air stripper).

No EMR response or direction. Text modified. An ESD was generated in March 1995 to explain the differences in the landfill contents remedy (i.e., no implementation of SVE). An ESD or ROD amendment however has not been generated for air stripper bypass of the extracted groundwater. An additional recommendation will be made to address this unresolved issue.

30 Hill Air Force Base Response to Five Year Review for Operable Unit 4: Please number this Table and its pages.


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31 Page 4-11, Table 4-2: The dates of First and Second Five Year Reviews should be included in this Table.


32 Hill Air Force Base Response to Five Year Review for Operable Unit 5: Please number this Table and its pages


33 Page OU5-9, Table OU5-2: The dates of First and Second Five Year Reviews should be included in this Table.


34 Hill Air Force Base Response to Five Year Review for Operable Unit 6: Please number this Table and its pages. This comment also applies to OUs 7-12.


35 Page OU6-9, Table OU6-2: The dates of First and Second Five Year Reviews should be included in this Table and for OUs 7-12.


Appendix A.4

USEPA Comments on May DRAFT of Five-Year Review Report

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1 EPA agrees with the comments submitted by UDEQ and, to avoid redundancy, will not restate such comments.

Not applicable. No action required in FYR Report.

2 It appears as though institutional controls may need a more thorough evaluation with respect to each operable unit. Please ensure that the institutional controls at each operable unit have been implemented and are protective of human health and the environment.

No EMR response or direction. No action. The institutional controls were reviewed for implementation and protectiveness. If any issues were identified, these issues were raised in the OU summaries. Please see site summaries for information requested.

3 Attached are EPA review comments on the indoor air pathway for this five-year review. Please review and adequately address all of these comments.

Not applicable. Not applicable.

EPA HD-Introductory

Text A thorough review of the vapor intrusion pathway needs to be performed, including a review of (1) the vapor intrusion model input parameters and (2) the adequacy of indoor air data already collected. Depending on the results of these reviews, a (3) reassessment of the COPCs for vapor intrusion may be needed. Also, an assessment of (4) the nature and extent of TCE degradation products in offsite groundwater plumes needs to be made. Each of these issues is discussed in more detail in the following paragraphs.

Not applicable. Not applicable.

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Comment I.D. Regulator Comment EMR Review/Direction URS Action HD-1 The model input parameters need to be reviewed

because EPA has revised the recommended input parameters to the Johnson and Ettinger Model. The new values are somewhat more conservative than the previous values. As I understand from speaking with Gerry Henningson, the Johnson and Ettinger model was used at the site to determine whether or not vapor intrusion was likely to present a problem at the OUs with VOCs in groundwater. Only if the model indicated a potential problem was indoor air sampled. In my experience, most previous applications of the Johnson and Ettinger model were performed with inappropriate soil parameters, which have a marked affect on the predicted risk. I recommend that the model be rerun for a selected set of OUs and VOCs to determine whether the risk assessment calculations were performed with reasonably conservative exposure point concentrations. If you wish, I can perform this initial test with input from Wendy O’Brien for the toxicological factors. As an example, consider groundwater contaminated with cis-1,2-DCE. Assuming a concentration of 1000 ug/L, the old version of the model predicts an indoor air hazard quotient of 0.06, whereas the updated version predicts a hazard quotient of 0.5. The old value is below Superfund screening criteria, whereas the updated value is above.

Hill AFB is planning on conducting additional indoor air sampling at all OUs where migration of volatile organics into indoor air was considered in the risk assessment. This sampling will be performed at as many as 600 residential locations around the Base during the next couple of winter seasons. In the Basewide Air Sampling and Analysis Plan (BASAP) (previously submitted to EPA and currently being updated), Mitigation Action Levels (MALs) are described, above which indoor air mitigation systems will be installed. These MALs are based on risk-based criteria and background. As this air sampling will be the basis for decision-making, it is not necessary to update the indoor air modeling that has been performed at some of the OUs in the past.

The text was modified to mention current development of the BASAP for indoor air sampling in homes where migration of volatile organics into indoor air was considered in the risk assessment.

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Comment I.D. Regulator Comment EMR Review/Direction URS Action HD-2 In the cases where indoor air was sampled, the adequacy

of those data needs to be evaluated. Previous studies have shown that indoor air concentrations are strongly dependent on the season in which the indoor space was sampled. For example, at Lowry Air Force Base, indoor air sampled in the summer months typically yielded values at or below detection limits, whereas samples taken during the winter months yielded values one to two orders of magnitude greater. If at HAFB the indoor air samples were taken during the winter months, then the conclusion that vapor intrusion is not a significant exposure pathway is probably correct. If the samples were taken in the summer months, then the risks may be underestimated and I recommend re-sampling during the winter months. If additional sampling is deemed necessary, I recommend that subslab sampling be conducted at the same time as indoor air sampling. Subslab sampling gives a direct indication of which VOCs and at what level VOCs are reaching the foundation of buildings.

Hill AFB recognizes the impacts of seasons and weather on indoor air sampling results. Recent sampling events completed by Hill AFB sampling were completed during the winter months and this is one of the reasons that Hill AFB has planned to resample at all OUs where migration of volatile organics into indoor air was considered in the risk assessment. Hill AFB plans on conducting all future initial indoor air sampling during the winter months. Subslab sampling procedures and rationale for use are also incorporated into the BASAP, and will be employed where the source of indoor concentrations is in question and affects decision-making.

Text modified for all OUs where additional indoor air sampling was recommended to include the caveat that the sampling should be completed in the winter months.

HD-3 If reviews of the modeling or indoor air sampling suggest either effort needs to be updated for the COPCs evaluated, a reassessment of the COPCs should also be performed. The initial assessment may have used inappropriate input parameters or inadequate data to determine the COPCs.

In planning future indoor air sampling, Hill AFB will review previous groundwater, soil, and indoor air data to determine the appropriate analyte list for indoor air sampling at each Operable Unit. The BASAP provides the rationale on how COPCs will be chosen during the indoor air program.

No action required in FYR Report.

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Comment I.D. Regulator Comment EMR Review/Direction URS Action HD-4 Regarding nature and extent of groundwater plumes: The

five-year review suggests that at several OUs TCE concentrations are not decreasing as projected (For example, OU4 and OU5, as described in Table 9). In these plumes, and possibly all offsite plumes, the nature and extent of TCE degradation products should be evaluated to determine if their distribution and/or concentrations are increasing. As many of TCE’s degradation products are equally or more volatile than TCE itself, there may be an expanding area of concern with respect to vapor intrusion.

No EMR response or direction. Concur. Evaluation of degradation products should be a component of the PSVP development and PSVR process. The importance of this process, with respect to protectiveness, is described in the Site Management discussion in Section III. The text for the recommendation re: review of the PSVPs was modified to emphasize the importance of assuring all appropriate parameters be included in the PSVP.

4 Perchlorate sampling was not conducted at most of the operable units which are being reviewed in this five-year review. Please reassess the need for future perchlorate sampling at each operable unit and provide an explanation as to why future perchlorate sampling is not warranted.

Currently perchlorate is not regulated, however Hill AFB is in the process of conducting a voluntary investigation into perchlorate contamination in the groundwater at several locations. Previous investigations at OUs 5 and 12 have included perchlorate sampling. In addition to these OUs, perchlorate samples have been collected from selected locations within OUs 1,2,4,and 6 as part of the summer 2003 sampling rounds. Following a review of the perchlorate data collected, additional samples may be collected at these OUs, as well as others, during the fall 2003 sampling rounds. After our initial investigation is complete, a determination as to whether or not continued perchlorate sampling is necessary will be made.

No action required in FYR Report.

5 Please ensure that the word “five-year” is correctly spelled throughout the document.

No EMR response or direction. Text reviewed and spelling corrected.

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Comment I.D. Regulator Comment EMR Review/Direction URS Action Specific Comments

HD-1 Section III, Conclusions and Recommendations, Basinwide [sic] Findings, Changes in Chemical-Specific Clean-Up Levels, Page III-1: This section recognizes the new action level for TCE in indoor air, but fails to address the changes in toxicity values for other chemicals. The site toxicologist should be consulted to evaluate all possible changes, including those for compounds not originally considered to be COPCs.

See response to General Comments, HD-3. No action required in FYR Report.

HD-2 Section III, Conclusions and Recommendations, Basinwide [sic] Recommendations, Page III-5: The first bullet recommends evaluation of the potential for exposure to TCE vapors in a number of OUs. Based on the information provided in Figure 1, it appears that OUs 7, 9, 10, and 12 (in addition to OUs 1, 2, 4, 5, 6 and 8) should also be included in the re-evaluation. The vapor intrusion pathway for all VOCs at all OUs with groundwater plumes should be re-evaluated for the reasons given above under general comments.

See response to General Comments, HD-1. No action. OU 7 is a soils-only OU. The groundwater under contaminated soil is a part of OU 8. All vapor intrusion pathways associated with OU 7 would be assessed as a part of OU 8. OU 9, OU 10, and OU 12 are all in the RI phase of investigation. The potential for TCE vapor exposure for these OUs should be evaluated in the RI.

1 Table ES-1, Page ES-1: Please include another column to this chart. It would be very helpful if the actual operable unit designation was also listed by the various protectiveness determinations.

No EMR response or direction. Table modified.

2 Page III-5, Basewide recommendations: The 5th bullet uses the term “metrics”. Please explain what this term means or change the spelling if this is a typo.

No EMR response or direction. Word changed from “metrics” to “parameter”.

3 Page II-2, Table 3: The word “extent” is misspelled. Please correct.

No EMR response or direction. Spelling corrected.

4 Page II-3, Table 4: See above comment.

No EMR response or direction. Spelling corrected.

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Comment I.D. Regulator Comment EMR Review/Direction URS Action 5a Hill AFB Response to Five-Year Review for Operable

Unit 4: Please number these pages throughout the document.

No EMR response or direction. No action. The Hill AFB EMR Response to the May DRAFT is now included in Appendix A.

5b Hill AFB Response to Five-Year Review for Operable Unit 4: EPA does not agree with Hill AFB’s nonconcurrence on the last recommendation on the first page. This recommendation should have completed as part of this five-year review and therefore should, at a minimum, be evaluated in the future.

No EMR response or direction. Based on EMRs comment on the May DRAFT, the recommendation was reworded in the July DRAFT as follows: “Complete an investigation into the increase of TCE concentrations in U4-047 and closely monitor future analytical results from the location.” No additional action required due to EPA comment.

Appendix B

Community Input for the Hill AFB 2003 Five-Year Review

Note: No public comments were received by Hill EMR during the 30-day public comment period

Community Interviews A number of interviews were conducted with community members as part of the Five-Year Review process. Interviewees were asked questions regarding the cleanup program at Hill AFB. The process Hill AFB public involvement staff members conducted interviews with community members for the Five-Year Review. These interviews varied in length from 20 minutes to two hours. Questions were based on, but not limited to, those found in the Environmental Protection Agency’s Five-Year Review guidance. No recording or transcript of the interviews was made. The attached summaries are based upon handwritten notes taken during the interview. Upon request, interviewees were permitted to review and edit the summaries to ensure their comments were adequately recorded. Attached is the list of proposed interviewees. Some were either unwilling to be interviewed or were unavailable for interview during the interview timeframe. Summaries of the interviews conducted follow. Results summary In general, most of those interviewed were pleased with the progress of Hill’s cleanup program. They indicated satisfaction with the Air Force’s investigation and clean-up of the various sites and that the time taken to implement remedies at sites was appropriate. Most agreed with the remedies that were selected, and in general, say the communities are not adversely affected by investigation and cleanup operations. There was one notable exception. Mr. Brent Poll, a resident of South Weber representing the South Weber Landfill Coalition, was extremely critical of the base’s handling of the investigation and cleanup of contamination from Operable Unit 1. He said he believes the Air Force is purposely understating the risk posed by the contamination and the remedial response is not only insufficient, but irresponsible. He said he is concerned that South Weber city leaders are making poor decisions based on bad information received from the Air Force. He also expressed concern about using natural attenuation as a remedy for contamination at OU1. He said the monitoring network and frequency of monitoring is inadequate to determine whether or not natural attenuation is occurring. Major issues

• Property values. Some interviewees expressed concern that their property has been devalued as a result of cleanup operations and the contamination. Others, however, say they have not seen a reduction in property values.

• Property usage. Some interviewees criticized the Air Force and local city governments for not doing more to inform people that a particular piece of property might be near contamination. Some want to completely stop development in areas of contamination.

• Communication. Most interviewees said they thought the Air Force was doing a good job of keeping people informed. They said newsletters, city council visits,

InfoFairs and other outreach efforts were effective and appropriate. One of the interviewees said the Air Force was not doing enough and said the information presented was self-serving, misleading and inaccurate.

• Appropriateness of remedies. Mr. Poll, in particular, was critical of the remedy at OU1. He said natural attenuation was neither effective nor appropriate. Dr. John Carter, Mr. Poll’s technical advisor, said he believed the Air Force and the EPA selected the remedy at OU1 prior to any public input. He said he believes the Air Force and the EPA manipulated data to support the application of the pre-selected remedy. Other interviewees, however, said they believed the remedies that have been put in place around the base are appropriate and show a responsible use of taxpayer dollars. Roy residents were happy with the Air Force’s response to finding chemical vapors in basements. They were pleased the Air Force took immediate action to remove the vapors from their homes.

Based on the community interviews, the overall evaluation of the cleanup effort was positive. This result echoes what has been observed in other contexts, including InfoFairs, city council meetings and a comprehensive community survey conducted in 2000. While no one is happy about contamination in the community, most are pleased with the Air Force’s efforts to acknowledge its existence, quickly assess its risks and respond in an appropriate and timely manner.

Interviewee List

Name Affiliation Comment Brent Poll South Weber Landfill Coalition Interviewed Dr. John Carter South Weber Landfill Coalition Interviewed Scott Paxman Weber Basin Water District Interviewed Lynn Moulding Riverdale RAB representative Interviewed Gregory Fisher Clinton RAB representative Declined Jerry Everett Layton RAB representative Contacted-No response Chris Davis Roy City Manager Interviewed Jim Harris Weber State University Interviewed Merlin Mitchell Former Clinton RAB representative Contacted-No response Ron Chandler South Weber City Manager Contacted-No response Jeff Burton Roy resident Interviewed Faye Field Roy resident Interviewed Scott Ware Roy resident Unavailable Leigh Glaves Roy resident Unavailable Martin Sunset resident Unavailable Al Herring Sierra Club Interviewed

FIVE-YEAR REVIEW COMMUNITY INTERVIEW Mr. Brent Poll, South Weber Landfill Coalition (SWLC) Dr. John Carter, Technical Advisor to SWLC Interview by: Dave Harris Also present: Dave Allison, Utah Department of Environmental Quality Date: March 10, 2003 Time: 1 p.m. Location: Poll home

1. What is your overall impression of the cleanup effort?

Mr. Poll says Hill’s cleanup effort is flawed because it bases cleanup decisions on incomplete or incorrect data. He disagrees with using natural attenuation as a cleanup alternative in a populated area. He claims reports and studies have been falsified to support a pre-determined conclusion. He says Hill’s cleanup efforts are either inept or fraudulent. He said evidence exists that proves the Record of Decision (ROD) at Operable Unit 1 (OU1) is wrong. Dr. Carter said there is not an adequate monitoring network to justify the conclusions made in the ROD at OU1. He said the conclusions are not based on hard data, but on theory. He says the data are uncertain. He said he believes the Utah Department of Environmental Quality and the Environmental Protection Agency are “in bed” with the Air Force and conclusions were reached long before the documents and decisions were finalized.

2. What effects have site operations had on the surrounding community?

Mr. Poll said that developers and banks do not want to touch sites with pollution. He said Hill AFB reports say it is safe, but you can not say it is safe. People want to be far away from the pollution.

3. Are you aware of any community concerns regarding the cleanup or its operation and administration?

Mr. Poll said the South Weber City Council is torn. He said they want to tell people they are safe, but they really do not know if people are safe or not. They face pressures from many sides – developers, citizens, bankers, etc. People want to hear they are safe. He said land-use restrictions are the answer until we have more answers as to how safe it really is. He said land-use restrictions are the only way to be protective.

He said the cleanup standards are bogus because it is impossible to say what is safe. The people rely on the standards, but they are worthless.

4. Are you aware of any events, incidents, or activities at the cleanup sites, such as

vandalism, trespassing or emergency responses from local authorities?

Mr. Poll said a lot of people want to walk along the canal. He says the base should say something about the risk, but they do not. A lot of people walk up on the hillside near the contaminated springs. The fences are not adequate to keep people out.

5. Do you feel well informed about the cleanup’s activities and progress?

Mr. Poll said he is well informed.

6. Do you have any comments, suggestions or recommendations regarding the

cleanup’s management or operation?

Mr. Poll said he has pictures that show the Air Force’s premise is wrong. He believes the Air Force believed it was so powerful it could get away with it. He said the Air Force has perpetrated fraud on the people. Mr. Carter said the frequency of monitoring in South Weber is inadequate to monitor natural attenuation. He said the Air Force needs a more real-time way to track contamination migration. He said more indoor air sampling data points are required in South Weber. Mr. Carter said the Air Force should put more monitoring wells on the northeast side of the landfills. He said it would provide valuable data and would not be very expensive.

Five Year Review Community Interview Scott Paxman, Weber Basin Water Conservancy District Interviewed by: David Harris Date: March 10, 2003 Time: 3:00 p.m. Location: Weber Basin Water Conservancy District Offices

1. What are the main issues Weber Basin Water Conservancy District (Weber Basin) sees regarding the cleanup systems in place?

Paxman said Weber Basin is primarily concerned with protecting drinking water supplies – its numerous wells drawing water from deep-water aquifers and the Weber River.

2. What wells are of concern?

Paxman said there is a well near Hill’s South Gate (Laytona Well) and a couple of wells in Clearfield near the Operable Unit 10 (OU10) plume. He said neither well has shown evidence of contamination, but these are wells they like to keep an eye on.

3. Are Hill’s systems protecting the water supply adequately?

Paxman said in his opinion, Hill was doing an excellent job at putting in treatment systems that are effective. He said Hill AFB’s staff is always up-front about what they are doing and does a good job at keeping the Restoration Advisory Board up-to-date.

4. What does Weber Basin see that Hill could do to better protect the water supplies?

Mr. Paxman did not know of anything more Hill could do to protect water supplies. He mentioned the incident with South Weber Supply Well #2 (which occurred in the late 1990s) and that the Air Force put in a number of wells and showed clearly where the contamination was, and more importantly, where it was not. He said it was excellent information to provide to concerned customers who would call.

5. Does Weber Basin foresee the contamination from Hill AFB threatening water

supplies in the future?

Mr. Paxman said he did not see a foreseeable threat to the drinking water supply from Hill AFB contamination. He did say Weber Basin is planning to build a new treatment

plant on the northwest side of the base. This plant would treat both groundwater and surface water (from the Davis-Weber Canal) for use as drinking water. He said if volatile organic chemicals were present in canal water, Weber Basin would need to know so they could ensure the water was receiving proper treatment.

6. Has anyone from the pubic expressed concern to Weber Basin concerning the safety of the water supply and Hill AFB contamination?

Aside from the calls surrounding the South Weber Well #2 incident, Mr. Paxman said he gets few, if any, phone calls from the public.

Five Year Review Community Interview Lynn Moulding, Riverdale City/Community RAB Representative Interviewed by: David Harris Date: March 24, 2003 Time: 1:00 p.m. Location: Riverdale City Offices


Mr. Moulding said the cleanup effort has been good. He credited that to the close contact and cooperation between the city, the residents and the Air Force. It was helpful that the time to investigate and put a cleanup system in place was relatively short, he said.


Mr. Moulding said the cleanup system has had very little impact on the community. Initially there were concerns about how long it would take to get the cleanup system in place. He said after the cleanup system was put in place, there were few, if any, complaints.


Mr. Moulding said there have been very few complaints registered by the community. Most complaints received in context of the contamination have been directed more at the city than the Air Force, he said.

4. Are you aware of any events, incidents, or activities at the cleanup sites, such as vandalism, trespassing or emergency responses from local authorities?

Mr. Moulding said there has been no vandalism or any other problems in Riverdale.


Mr. Moulding said, for the most part, the Air Force has kept him informed. He said someone did approach him a few months ago regarding discharging into the city sewer lines, but no one ever followed up on that request.


cleanup’s management or operation.

Mr. Moulding had no comments or suggestions.

Five Year Review Community Interview Chris Davis, Roy City Manager Interviewed by: David Harris Date: April 22, 2003 Time: 8:30 a.m. Location: Roy City Offices


Mr. Davis said that he sees a very concerted effort. He said it is very positive to see an open process coming from the federal government. He said he believes the word is getting out to people and the Air Force is being proactive.


He said he has heard no complaints from the community about anything that is going on. He said some people expressed concern when they first learned of the contamination, but he credits the Air Force’s proactive response to the lack of general fear and anger in the community.


He said he and the city appreciate the Air Force’s handling of the process. He said the frequent meetings are helpful. He said the mayor is particularly interested in what is going on, since he is near the contamination, as are two planning commission members. He said he has not heard anything but positive comments from them.


He said no vandalism or problems have been reported.


He said he feels well informed about the cleanup. He thinks the level of information is good and that the city council is hearing what they need to hear to make informed

decisions. He offered the use of the city’s newsletter for any updates that need to go out to the residents.

6. Do you have any comments, suggestions or recommendations regarding the cleanup’s management or operation.

He offered no suggestions, other than for the Air Force to keep doing what it has been doing.

7. Other issues:

One issue raised regarded the city’s efforts to inform residents of the contamination in Roy, especially in notifying developers of contamination. Mr. Davis said there is no need for a formal process to inform developers of the contamination because there is little if any developable property in the plume or in the projected path of the plume. Any undeveloped property in the path of the plume has already started the development phase and the developers are aware of the contamination.

FIVE-YEAR REVIEW COMMUNITY INTERVIEW Jim Harris, Weber State University Interview by: Barbara Fisher and Carly Brown Date: March 28, 2003 Time: 1 p.m. Location: Weber State University

1. What are the main issues Weber State University sees regarding the cleanup systems in place?

Mr. Harris said WSU is concerned about future development on the Davis campus. The university’s long-range plan calls for adding 11 or 12 more buildings on the campus, one every few years depending on enrollment demands/funding. This campus could eventually be larger than the main campus in Ogden if enrollment predictions hold up. The first building on the campus is currently under construction and will have 31 classrooms and 3 auditoriums that will hold 100 people each. Approximately 3,500 to 4,000 students can attend classes in the four colleges that will work out of the first building on the campus. The facility will be open 6:30 a.m.-10 p.m., and classes will start in August.

2. What effects have Hill AFB’s operations had on Weber State University?

Mr. Harris said there were no significant effects on Weber State University’s plans/designs at the new campus. He said in some places where Hill AFB monitoring wells are located, piping had to be extended to avoid or go around the monitoring wells, but no fixes were required in the design. Mr. Harris said he was comfortable with the Hill AFB environmental staff’s level of participation in WSU’s planning for the new campus and said the base staff worked closely with Mike Perez early on in the process. He said Robert Petrie of the Hill AFB environmental staff was really helpful during the process.

3. Are you aware of any community concerns regarding the new Weber State University campus and the Hill AFB groundwater contamination?

Mr. Harris said he had received calls from a couple of residents, one of whom had questions about what TCE is. He said he felt comfortable answering the questions because he was familiar with TCE. Mr. Harris is also a member of the Hill AFB RAB. Mr. Harris said he has spoken with neighbors about the new campus, especially those to the south, and they were concerned about dust and noise during construction. There are

approximately 150 houses in the neighborhood. Mr. Harris said the university held a public meeting with these residents last fall (2002) and there were questions raised about the groundwater contamination (How deep is the contamination? How far does the contamination go?) Mr. Harris said he also received a call from an individual who claims the rights to the groundwater that flows through the decades-old field drains located on the WSU property. The individual was concerned about interruption of the groundwater flow to her property where the water surfaces. The individual was aware that the water was for irrigation purposes only and it had been tested and was not contaminated.

4. Are you aware of any events, incidents or activities at the site such as vandalism,

trespassing, or emergency responses from local authorities? If so, please give details?

Mr. Harris said he was a little concerned about possible vandalism on the campus property. He said he saw people out racing around in a car on the property. He said the university has installed gates, but anyone racing like that on the property could hit the monitoring wells too.

5. Do you feel well informed about Hill AFB’s environmental activities and progress?

Mr. Harris said he does feel well informed about Hill AFB’s environmental activities and progress.

6. Do you have any comments, suggestions or recommendations regarding the OU-8 site’s management or operation?

Mr. Harris said the OU-8 project appears pretty well in hand. He did ask why the Operations and Maintenance (O&M) costs are so high for the project. He said he deals with O&M all the time. He said the cost of a technician to monitor 18 wells was high.

7. Did the groundwater contamination on the site of the new campus cause you to make modifications to plans, have construction delays, budget concerns, etc.?

Mr. Harris said the groundwater contamination did slow the university down a little bit in its construction project. There were dewatering issues because groundwater was encountered. Also because of concern about the contamination in the groundwater, the groundwater was tested. Mr. Harris also said 12-15 feet below the natural grade on the property a solvent odor could be smelled. Because of this, the water and air in this location was sampled. Nothing was found of concern in either instance.

8. Do you foresee any impact to the Weber State facility in Layton with the Air Force’s proposed direction for clean up?

Mr. Harris said he thinks this is a pretty good plan and it was good to hear about it. He said he would like more information about Pond 2 and whether the pond collected any contaminated run-off and has this run-off been eliminated. Mr. Harris said he thinks everybody is going about (the clean-up) as logically as they can.

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FIVE-YEAR REVIEW COMMUNITY INTERVIEW Mr. And Mrs. Jeff Burton, Roy residents Ms. Faye Field, Roy resident Interview by: Barbara Fisher and Carly Brown Date: April 16, 2003 Time: 6:30 p.m. Location: Roy City Public Works Department

1. Do you feel the Air Force has been responsible enough in getting out the word on the contamination and its health risks and taking appropriate action? Why or why not?

Ms. Field said she feels the Air Force has been responsible. She said that once the Hill AFB environmental staff realized there was a problem, they worked to fix it and she has a good relationship with the people doing the sampling and other work in her home.

Mr. Burton said the Hill AFB response has been good. He said he only asked twice to have his air tested. He said he is very happy with the technical people and they have been very responsive. He said he was a “little disappointed” about the notification process to residents. He said he was concerned that only those in the “hot spot” area were being contacted and that residents living north of him are unaware they live over a plume of contaminated groundwater. He also said he is unhappy that the Roy City Council decided not to require new housing developments in the plume area to have passive remediation systems. He said that while the council did decide to put a notification on the city’s plat map, most homebuyers would likely not notice this. He said passive remediation systems could be installed in all new homes at no cost to the builder or homebuyers because the Air Force would pay for the work

How does getting this word out today compare vs. a year ago? Mr. Burton said word of mouth is how most people are getting their information now. He said he has not seen any new information lately. He said people in the area know more about the contamination than they did a year ago and that is probably due to the media.

2. Do you feel well informed about Hill AFB’s environmental activities and progress?

Ms. Field said she feels well informed. She has lived in her home 76 years and said she understands that the vapors in her home are due to the contamination and the level of the water table where she lives. Mr. Burton said Hill is doing a splendid job. He said he calls Hill project managers and gets answers to questions he has. He also said letters he has received and InfoFairs he has attended have been very informative and have helped others in the area understand what is going on.

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3. Are you aware of any community concerns regarding the contamination?

Mr. Burton said he worries when the Environmental Protection Agency (EPA) states that the levels of Trichloroethene (TCE) in homes in the area are not a health risk. He said he knows the levels of TCE in the vapors and water in Roy are not high enough to be considered a health risk to a healthy individual, but wants to know if the EPA has looked at the effects on the elderly, children and those who are hypersensitive to the contaminants. He also questions the statement that TCE is not a known carcinogen in humans and he said the statement “there is no significant health risk” is misleading.

4. Do you feel the vapor mitigation system is a sufficient remedy for the problem?

Ms. Field said she has been healthy all her life. She said her home is different from other homes in Roy in that it has a basement and a crawl space, and because of this, two remediation systems have been installed in her home. She said the systems seem to work as they should.

Mr. Burton said he is happy with the continuing process. He said he was unhappy when the Air Force just wanted to seal or caulk the cracks in his basement because the caulk has a shelf life. He said he is happier with the standard remediation system now in his home. He recommends that someone with a scientific background be part of the decision making process on where to place the remediation system in a home. He said someone other than the contractor in charge of installing the system should come in and make the recommendation on where to put the system and to not just put it where the homeowner would like it.

Have you heard any feedback from others in the community?

Ms. Field said that some in her community had expressed some curiosity about the system. A prospective buyer called Mr. Burton to ask questions about the remediation system in his home. The buyer was interested in the home next to Mr. Burton. The buyer did try to move forward with the purchase of the home but was not able to for unknown reasons.

5. Why did you decide to put the system in your home and are you satisfied with the work?

Ms. Field said she decided to put the systems in her home due to Hill AFB’s recommendation. She is satisfied with Hill’s recommendations because they are doing something about the problem and they told her it would help the problem.

Mr. Burton said he researched the options for remediation of the vapors and believes dilution of the air in his basement is the best solution. He said he likes the vapor mitigation system because it has been used to treat Radon. He suggested that standards be

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established for the remediation system, including setting specifications on the slope angle of the system’s pipes to prevent condensation buildup.

6. Do you foresee any problems with the system in the future?

Mr. Burton said he thought the system and remediation was an acceptable approach. He said that if he did have a problem there was a number he could call. In his past experiences, someone is there by the next day. He said also has Hill AFB project managers’ phone numbers.

Has the presence of the system caused you to make any lifestyle changes?

Mr. Burton said the system makes him feel better and said he thinks it is actually safer. He said he feels that his home value has gone up with the system in place because without the system it would be more dangerous.

7. Are you comfortable with the quarterly air sampling regiment?

Ms. Field said that she was fine with the quarterly sampling.

Mr. Burton said he is comfortable with the quarterly sampling, but that the ideal sampling time to show the highest TCE concentrations would be when the ground is frozen and homes are all sealed up. He said he would like to see a published schedule for the quarterly sampling so he would not dilute the air in his basement before sampling occurs. He said he would also like the flexibility of calling and requesting sampling in his home. He said he is also concerned about the tri-level nature of his home and would like another air sampling canister placed on his second level, near the garage to ensure the remediation system is working effectively in all areas of his home.

8. Do you have any comments, suggestions, etc?

Ms. Field said that she just wants Hill AFB to continue to clean up the contamination. She said that now that Hill has found a system that works to keep up the good work.

Mr. Burton said the evolution from caulking basements to installing the remediation system has made him realize that Hill is trying to do what is best and gives him great confidence in the work being done. He said he would like to be notified of future city council presentations by Hill AFB so he can attend.

Five-Year Review Community Interview Al Herring, Sierra Club RAB Representative Interviewed by: David Harris Date: April 2, 2003 Time: 1 p.m. Location: Herring home


Mr. Herring said he believed the cleanup effort was effective and appropriate. He said as a taxpayer, he feels good about it. He said, from his perspective, he believes the base is taking appropriate actions to clean up the sites. He said the cleanup proposed for Operable Unit 8 (OU8) seems appropriate.


Where he lives, which is outside the contaminated area, there is no direct impact on his community. However, he says the base seems to have accommodated the people’s concerns. He said the base has done a good job of communicating with people doing construction and drilling wells.


He said he is surprised and disappointed that the Sierra Club has not taken more of an interest in the cleanup. However, he acknowledged that the issues surrounding the cleanup are not “Sierra Club-type” issues. He has not heard any negative comments from the public.


No.


He said he is comfortable with the information he is receiving. As a member of the RAB, he said he feels like he gets good information. He said he feels privileged to be a part of

the RAB. He appreciates the Air Force’s quick and open response to his concerns and questions.


cleanup’s management or operation.

Mr. Herring did not have any specific suggestions.

Appendix C

Documents Reviewed and Personal Communications for the Hill AFB 2003 Five-Year Review

Documents Reviewed for Hill AFB 2003 Five-Year Review

Page 1 of 9

100 Percent Technical Specifications - SVE System Remedial Design Operable Unit 3, Montgomery Watson, September 1996. 2001 Cost & Performance Report, Operable Unit 1, Hill AFB, UT, URS, 11 February 2002. 2001 Cost and Performance Report Operable Unit 2, URS, March 2002. 2001 Operation and Maintenance Report Building 225 Floor Slab Operable Unit 7 Hill Air Force Base, Utah, URS, March 2002. 2001 Operation and Maintenance Reports OU 3 Sodium Hydroxide Tank Site Cap and Berman Pond Cap, OU 4 Landfill 1 Cap and Soil Vapor Extraction Drain System, and OU 7 Building 225 Floor Slab, Hill Air Force Base, Utah, URS, March 2002. AATDF Surfactant/Foam Process for Aquifer Remediation, Rice University, November 1997. Action Memorandum Operable Unit 5, Hill AFB, Radian International, March 1996. Action Memorandum Operable Unit 6, Radian, December 1996. Addendum to Remedial Investigation Report for Operable Unit 4, Volume 12 Appendices A, B, C, D, E, and F (Vol 2 of 8), U.S. Geological Survey, April 1993. Annual Report for Landfill 1 Cap Operable Unit 4, Montgomery Watson, November 1999. Annual Report for Operable Unit 3 Sodium Hydroxide Tank Site and Berman Pond, Montgomery Watson, December 1999. Annual Report for Operable Unit 4 - 1997, Montgomery Watson, November 1997. Annual Report for Operable Unit 7, Montgomery Watson, December 1998. Annual Report for Operable Unit 7 Building 225 Floor Slab, Montgomery Watson, November 1999. Bamberger Pond NFRAP Action Memorandum, Hill AFB EMR, June 2000. Baseline Risk Assessment for Operable Unit 2 Sites WP07, SS21 Volume 1 Report, Radian, March 1992. Baseline Risk Assessment Operable Unit 5 Sites SS17, SD16 Executive Summary, Radian, February 1995. Building 205 Record Drawing, Installation of Lines and Tanks for Industrial Waste, Buildings 225 and 205, Sheet 1., Hill Air Force Base Civil Engineering, December 1957. Building 454 Investigation Tech Memo Operable Unit 9 Final, Montgomery Watson, November 2000. Building 786 No Further Response Action Planned Decision Document, IRP Site SS092, Final Report, CH2M Hill, September 2002.


Page 2 of 9

Comprehensive Event Report, Hill AFB EMR, November 2000. Comprehensive Remedial Investigative Report for Operable Unit 1 (IRP Site LF01, LF03, WP02, FT09, OT14, FT81, and WP80) Volume 1, Montgomery Watson, December 1995. Construction Completion Report for Operable Unit 8 Interim Remedial Action Hydraulic Containment System, Montgomery Watson, January 1999. Contract F42650-98-D-0067, Delivery Order 0020, Cost Reimbursable Project Number 1. - Draft Operable Unit 4 Sewer Connection Soil Sampling Letter Report, CH2M Hill, 2 April 2003. Decision Document for IRP Site SD40A Category III NFRAP Pond 6, Hill AFB EMR, March 1998. Decision Document for Perimeter Road, Site SS21, Hill AFB EMR, June 1991. Decision Document for Site OT20- Spoils Area, Hill AFB EMR, June 1992. Draft 2002 Cost and Performance Report, Operable Unit 2, Hill Air Force Base, Utah, URS Corporation, March 2003. Draft Basewide Air Sampling and Analysis Plan Indoor Residential Air Sampling, Montgomery Watson Harza, October 2002. Draft Conceptual Model for Operable Unit 5, May 2001, Montgomery Watson, May 2001. Draft Final Feasibility Study, Operable Unit 5, Radian International, May 1996. Draft Final South Area of Operable Unit 9 Site Inspection - Final Comprehensive Data Evaluation, CH2M Hill, October 1997. Draft Remedial Action Report Operable Unit 2 North Interceptor Trench, Spring U2-326 Interceptor Trench, Containment Wall, and Air Stripper Treatment Plant, CH2M Hill, March 2000. Draft Subsurface Investigation Report and Corrective Action Plan for Building 454, LUST Site EIHG, Dames and Moore, January 1996. Draft Treatment System Operation Report, OU 5 Phase I Aeration Curtain, January - December 2002, URS, 24 December 2002. Engineering Evaluation and Cost Assessment (EE/CA) Addendum For Operable Unit 5, Montgomery Watson Harza, January 2002. Engineering Evaluation/Cost Analysis for the OU9 Pond 1 Removal Action, Final Report, CH2M Hill, April 2002. Engineering Evaluation/Cost Analysis Operable Unit 5, Radian, December 1994. Feasibility Study for Operable Unit 3 (IRP Sites ST04, WP05, WP06, ST18, SD23, SD34), Montgomery Watson, March 1995.


Page 3 of 9

Feasibility Study Report for OU 8, Montgomery Watson Harza, March 2003. Federal Facilities Agreement Under CERCLA Section 120, EPA Region VIII, April 1991. Federal Register Vol. 52, No. 140, Environmental Protection Agency, 22 July 1997. Final 2000 Cost and Performance Report, Operable Unit 2, Hill Air Force Base, Utah, URS, 15 February 2001. Final Analytical Data Report (ADR) For Operable Unit 9 Investigation Areas 1 May Through 10 October 2000, Montgomery Watson, February 2001. Final Conceptual Model for Operable Unit 5, Oct. 2001, Montgomery Watson Harza, October 2001. Final Conceptual Model for Operable Units 5 and 12, Montgomery Watson Harza, September 2002. Final Contaminant Transport Model Report for Operable Unit 5, Montgomery Watson Harza, February 2002. Final Data Summary Report and Preliminary Conceptual Model for Operable Unit 9 Investigation Areas, Montgomery Watson, October 2000. Final Decision Document for Fire Training Area 1, U.S. Air Force Installation Restoration Program, Hill Air Force Base, Utah, July 1989, Science Applications International Corporation, July 1989. Final Decision Document for IRP Site OT 029 Category III NFRAP Building 204 Beryllium Underground Waste Tank, Hill AFB EMR, March 1998. Final Decision Document for Site OT14 - Golf Course, Hill Air Force Base, Utah, Hill AFB EMR, May 1991. Final Decision Document for Site SS28, Sill Property, Hill AFB EMR, June 1991. Final Dense Nonaqueous Phase Liquid (DNAPL) Source Delineation Report Operable Unit 2, URS Corporation, September 1999. Final Draft Abatement and Initial Site Characterization Report Building 454, Site EIHG, Dames and Moore, October 1994. Final Fate and Analysis of Arsenic and Manganese in the Vicinity of Bamberger Pond, URS, June 2000. Final Feasibility Study Report for Operable Unit 1 (IRP Sites LF01, LF03, WP02, FT09, OT14, FT81, and WP80), Hill Air Force Base, Utah, Radian International, January 1998. Final Interim Remedial Action Hydraulic Containment System Operations and Maintenance Plan Operable Unit 8, Hill AFB Volume I of III, Montgomery Watson Harza, April 2002. Final Interim Remedial Action Report for Operable Unit 8, Montgomery Watson, September 1998.


Page 4 of 9

Final Operable Unit 1 Phase I Remedial Action Groundwater Extraction System Operation and Maintenance Plan, CH2M Hill, August 2002. Final Operable Unit 2 Panel 1 and 5 Surfactant Enhanced Aquifer Remediation (SEAR) Report, URS Corporation, February 2002. Final Operable Units 5 and 12 Active Soil-Gas Survey Source Area Investigation Report, Montgomery Watson Harza, June 2002. Final Operable Units 5 and 12 Historic Site and Source Area Review, March 2002, Montgomery Watson Harza, March 2002. Final Operation and Maintenance Manual, Aeration Curtain, OU 5, Radian International, October 1998. Final Record of Decision and Responsiveness Summary for Operable Unit 2, CH2M Hill, September 1996. Final Remedial Action Project Report For Operable Unit 2 Spring U2-304 Seep Intercept System, Montgomery Watson, July 2000. Final Remedial Action Report Pond 10 Pumping Facility Construction at OU 1, Radian, August 2000. Final Remedial Investigation/Feasibility Study Work Plan for Operable Units 5 and 9 Investigation Area, Montgomery Watson, May 2002. Final South Area Of Operable Unit 9 Site Inspection, Final Comprehensive Data Evaluation, Volume 1, CH2M Hill, February 2001. Final Summary Report for Chromium Cleanup at Two Sites in Layton, Utah, James M. Montgomery Consulting Engineers Inc., 1 February 1991. Focused Feasibility Study for Operable Unit 2, Hill AFB EMR, February 1991. Geotechnical Report OU 4 Proposed Extraction Trenches Long-Term Impact Review, URS, January 2001. Guidance for Remedial Actions for Superfund Sites with PCB Contamination, Environmental Protection Agency, August 1990. Hill AFB Environmental Restoration Management Action Plan - 2001, Montgomery Watson Harza, September 2002. Hill AFB Five-Year Review, September 1998, Hill AFB EMR, September 1998. http://www.epa.gov/OGWDW/mcl.html, Environmental Protection Agency, February 2001. Innovative Subsurface Remediation: Field Testing of Physical, Chemical, and Characterization Technologies. American Chemical Society Symposium Series 725, American Chemical Society, January 1999.


Page 5 of 9

Intent to Shut Down and Bypass Treatment Equipment at Operable Unit 6 Off-Base Systems, Hill AFB EMR, 7 January 2002. Interim PCB Contaminated Soil Removal Report for Electrical Substation No. 2, Radian, June 1999. Interim Remedial Action Field Work Data Summary and Remedial Design Technical Memorandum Operable Unit 8, Montgomery Watson, March 1996. Memorandum, Comparison of Standards and Cleanup Levels at Hill AFB, URS, 16 December 2002. Minutes, First RAB Meeting, January 12, 1998, Hill AFB EMR, January 1995. Monthly OU 1 Operations Summary Reports (Jan - Dec), URS, January 2002. National Primary Drinking Water Standards, Environmental Protection Agency, December 1999. North Area Preliminary Assessment Report, June 1995, Final, Montgomery Watson, June 1995. OO-ALC-HAFB Supplement I, AFI 32-7020, 29 April 1998, Hill AFB, 29 April 1998. Operable Unit 1 Fire Training Area 2 No Further Response Action Planned (NFRAP) Decision Document, IRP Site FT081, State of Utah, Department of Environmental Quality, Leaking Underground Storage Tank Site EIIK, Hill Air Force Base, Utah, August 2001, CH2M Hill, August 2001. Operable Unit 2 Source Removal System and Industrial Waste Treatment Plan Modifications Construction Report, Radian, January 1994. Operable Unit 4 Performance Standard Verification Plan, CH2M Hill, November 2001. Operable Unit 6 Cooley's Pond Treatment System Monthly Operation Summary, January - August 2002, URS, 31 August 2002. Operable Unit 6 Off-Base (Craigdale) Pump-and-Treat System Monthly Operation Summary, January - August 2002, URS, 31 August 2002. Operable Unit 9 Calendar Year 2001 Deferred Sites Inventory Report, Hill Air Force Base, Utah. Draft, CH2M Hill, August 2002. Operation and Maintenance Manual On-Base Pump and Treat System, Operable Unit 6, Final Revision 1, URS, July 2002. OU 1 Source Zone Delineation Progress Report, Intera, 26 September 2002. OU 10 RI/FS, Operable Unit 10 Analytical Data Report, May 1, 2001 - January 31, 2002, CH2M Hill, July 2002.


Page 6 of 9

OU 12 Base Boundary Hydraulic Containment System Work Plan, Montgomery Watson Harza, June 2002. OU10 Remedial Investigation/Feasibility Study Operable Unit 10 Analytical Data Report, May 1 2001 - January 31 2002, CH2M Hill, July 2002. OU11 Remedial Investigation/Feasibility Study, Operable Unit 11 Analytical Data Report, May 1 2001 - January 31 2002, CH2M Hill, November 2002. OU6 LTM-O&M Data.xls, URS, 17 December 2002. PCB Spill Sampling and Cleanup in Building 225, Hill Air Force Base, Utah, Hill AFB EMR, November 1989. Performance Standard Verification Plan For Phase III EE/CA, Operable Unit 5, Montgomery Watson Harza, October 2001. Performance Standard Verification Plan Operable Unit 1, CH2M Hill, April 2001. Performance Standard Verification Plan Operable Unit 2, CH2M Hill, November 2001. Performance Standard Verification Plan Operable Unit 3, CH2M Hill, November 2001. Performance Standard Verification Plan Operable Unit 6, URS, November 2001. Preliminary Assessment/Site Investigation, Building 1946 Evaporation Pond, ERM-Rocky Mountain, Inc., January 1993. Proposed 1st Round Cone Penetration Testing Locations for the 800 / 900 Area, Operable Unit 11, CH2M Hill, 12 February 2002. Proposed Explanation of Significant Differences for Operable Unit 4 Landfill Contents Remedy, USEPA Region VIII, March 1995. Proposed Plan for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42), Montgomery Watson, September 1993. Record of Decision and Responsiveness Summary for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42), Hill AFB EMR, June 1994. Record of Decision for an Interim Remedial Action at Operable Unit 8, Hill AFB, May 1997. Record of Decision for Interim Action at Operable Unit 2, HAFB EMR, December 1990. Record of Decision for Interim Action at Operable Unit 2, Final, HAFB EMR, August 1991. Record of Decision for Interim Action at Operable Unit 3 Site ST04, Hill AFB EMR, September 1992. Record of Decision for Operable Unit 3, Hill AFB EMR, September 1995.


Page 7 of 9

Record of Decision for Operable Unit 7, Hill AFB EMR, September 1995. Record of Decision Operable Unit 1 IRP Sites LF01, WP02, LF03, FT09, FT81, and WP80, Hill AFB EMR, September 1998. Record of Decision Operable Unit 6 Sites ST022, OT026, SD40B, Radian, August 1997. Remedial Action Project Close-Out Report for Operable Unit 3, Montgomery Watson, April 1999. Remedial Action Project Close-Out Report for Operable Unit 7, Montgomery Watson, August 1998. Remedial Action Report for the Landfill 1 Cap Site (IRP Site LF11), Hill AFB EMR, August 1997. Remedial Action Report Phase II Remedial Action Horizontal Drain Upgrades Operable Unit 4, CH2M Hill, January 1998. Remedial Design / Remedial Action Work Plan and Design Analysis Report, Operable Unit 6, Final, Radian, March 1998. Remedial Design Report and Work Plan for Operable Unit 3, Montgomery Watson, February 1997. Remedial Design Report and Work Plan Operable Unit 1, CH2M Hill, February 2000. Remedial Design Report and Work Plan Phase III Groundwater Extraction Trench System Operable Unit 4, CH2M Hill, January 1999. Remedial Design Report and Work Plan Schedule A and B Construction Operable Unit 2, CH2M Hill, December 1997. Remedial Design Work Plan for Operable Unit 4 (IRP Sites LF11, LF12, OT20, OT41, OT42), Hill AFB EMR, February 1995. Remedial Design/Remedial Action Work Plan for Operable Unit 7, Montgomery Watson, August 1996. Remedial Investigation Report for Operable Unit 2 Sites WP07, SS21 Volume 1 Report and Appendices A & B, Radian, July 1992. Remedial Investigation Report for Operable Unit 3 (IRP Sites ST04, WP05, WP06, ST18, SD23, OT33, SD34, and SD46), Draft Final, James M. Montgomery Consulting Engineers, April 1992. Remedial Investigation Report for Operable Unit 4 Volume 2 Baseline Risk Assessment, James M. Montgomery Consulting Engineers, November 1991. Remedial Investigation Report for Operable Unit 8, Montgomery Watson Harza, December 2001. Remedial Investigation Report Operable Unit 5 Sites SS17, SD16 Volume 1 - Text, Radian, May 1995. Remedial Investigation Report Operable Unit 6 Sites ST22, OT26 Volume 1 Text, Radian, July 1995.


Page 8 of 9

Remedial Investigation Report Operable Unit 6 Sites ST22, OT26 Volume 2 Appendices, Radian, July 1995. Remedial Investigation/ Feasibility Study Report for Operable Unit 7 (IRP Sites SS27, ST31, & SS32) Volume II (Appendices A-L), Montgomery Watson, February 1995. Remedial Investigation/Feasibility Study Report for Operable Unit 7 (IRP Sites SS27, ST31, & SS32) Volume I (Text), Montgomery Watson, February 1995. Report Repository Operation and Performance Reports Interim Remedial Action Hydraulic Containment System Operable Unit 8, April 2000-March 2001, Hill AFB, Utah, Hill AFB, January 2001. Revised Final - Site Inspection Report of Operable Unit 9 North Area, Montgomery Watson, July 2000. Risk-Based Concentration Table, EPA Region III, October 9, 2002, EPA Region III, 9 October 2002. Site Characterization Report for a Portion of Building 225 and Site Investigation of Fill Soils at Base Supply Well 6, James M. Montgomery, Consulting Engineers, December 1991. Site Conceptual Model Review OU 4, Jacobs Sverdrup/Intera Inc., December 2002. Statement of Concurrence With No Further Response Action Planned (NFRAP), Building 514 Refueling Vehicle Maintenance Facility (RVMF), Installation Restoration Program (IRP) Site ST018, URS Greiner, Inc., May 2001. Subsurface Investigation Report for Underground Storage Tank Site 454, CH2M Hill, February 2001. Synopsis of Regulatory Review for OU6 Craigdale Discharge, Hill AFB EMR, 8 October 2002. System Evaluation Report SRS Commissioning, Startup, and Initial Operation Interim Remedial Action, 2, Radian, February 1995. Technical Memorandum Baseline Risk Assessment for Operable Unit 4, James M. Montgomery Consulting Engineers, April 1990. Technical Memorandum Second Draft Vol 1 Report Site Characteristics Summary Report, First Phase of Remedial Investigation, Operable Unit 4, Landfills 1 and 2, U.S. Geological Survey, January 1990. Treatment System Operation Report Interim Remedial Action Hydraulic Containment System Operable Unit 8, Hill AFB, Utah, URS, June 2002. Treatment System Operation Report Operable Unit 6 Cooley's Pond Pump-and-Treat System, Hill Air Force Base, Utah, January - December 2002, URS, February 2003. Treatment System Operation Report Operable Unit 6 Craigdale Pump-and-Treat System, Hill Air Force Base, Utah, January - December 2002, URS, February 2003. Treatment System Operation Report Operable Unit 6 On-Base Pump-and-Treat System, Hill Air Force Base, Utah, January - December 2002, URS, January 2003.


Page 9 of 9

Treatment System Operation Report, Craigdale Pump-and-Treat System, Operable Unit 6, URS, March 2002. Treatment System Operation Report, On-Base Pump and Treat System, Operable Unit 6, URS, 18 February 2002. U.S. Air Force Installation Restoration Program Remedial Investigation/Feasibility Study Hill AFB, Utah, Decision Paper Site SD046 - Storm Pond 2 No Further Response Action Planned, Hill AFB EMR, 30 June 1992. UCS O&M and Performance Verification Plan Operable Unit 2, Radian International, July 1997. Utah Rule R309-200, Monitoring and Water Quality: Drinking Water Standards, State of Utah, July 2002. Vol. 1 Report Remedial Investigation Report for Operable Unit 4, U.S. Geological Survey, June 1992. Vol. 1 Report Remedial Investigation Report for Operable Unit 4, First Draft, U.S. Geological Survey, September 1991. Work Plan for South Area of Operable Unit 9 Site Inspection Volume 1: Report and Appendices A-D, CH2M Hill, December 1995.

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Personal Communication Between URS Evaluation Team and the following for Hill AFB 2003 Five-Year Review

Elliott, B., EMR Chief Administrator, Hill AFB EMR, 02 January 2003.

Esplin, T., Engineer for OU 5 O&M Contractor, URS, 06 February 2003.

Esplin, T., Site Engineer for OU 6, URS, 27 January 2003.

Evans, S., Site Engineer for OU 6, URS, 08 January 2003.

Holt, M., ERPIMS Database Manager, Hill AFB EMR, 31 December 2002.

Knutson, S., OU 5 O&M Contractor, URS, 12 February 2003.

Loucks, M., Historical PM for OU 12, Hill AFB EMR, 11 February 2003.

Loucks, M., Project Manager for OU 6, Hill AFB EMR, 18 March 2003.

Mills, D., Project Manager for OU 12, EMR, 05 March 2003.

Renn, H., OU 4 O&M Project Manager, URS, 24 February 2003.

Rolfsness, S., OU 11 Project Manager, Hill AFB EMR, 31 December 2002.

Rolfsness, S., OU 11 Project Manager, Hill AFB EMR, 02 January 2003.

Smith, S., OU 9 Project Manager, Hill AFB EMR, 13 February 2003.

Torres, O., O&M Project Manager for OU 6, Hill AFB EMR, 28 January 2003.



Torres, O., O&M Project Manager for OU 5, Hill AFB EMR, 06 February 2003.

Vicelja, J., Consulting Engineer, P.E., Joseph Vicelja Consulting Engineering, 07 February 2003.

Watkins, J., EM Operations Program Manager, Hill AFB EMR, 24 October 2002.

Watkins, J., EM Operations Program Manager, Hill AFB EMR, 13 March 2003.

Appendix D

Inspection Checklist and Sample Site Interview Questionnaire

5/2/03

OU 7 EMR Date: Time:

PERFORMANCE, OPERATION AND MAINTENANCE PROBLEMS (EMR)

1. What do the monitoring data show?

2. How successfully is the remedy performing (progress toward RAOs, PRGs, etc.)?

3. Are there any trends that show contaminant levels are decreasing?

4. What is the operational uptime and removal efficiency goal for the system?

5. What has the actual operational uptime and removal efficiency goal been for the past 1 year, 2 years, etc.? What data is this based on?

6. Is there a continuous on-site O&M presence? If so, please describe staff and activities. If there is not a continuous on-site presence, describe staff and frequency of site inspections and activities.

7. Have there been any significant changes in the O&M requirements, maintenance schedules, or sampling routines since start-up or in the last five years? If so, do they affect the protectiveness or effectiveness of the remedy? Please describe changes and impacts.

8. Have there been unexpected O&M difficulties or costs at the site since start-up or in the last five years? If so, please give details.

9. Have there been any typical/recurring performance problems with the system?

10. Have there been opportunities to optimize O&M or sampling efforts? Please describe changes and resultant or desired cost savings or improved efficiency.

11. Is the sampling plan adequate to determine effective treatment, capture, etc.? What information is your determination based on?

12. Has there been unexpected contamination found outside the capture zone or any indication of an unknown source?

13. What is the overall goal of this remediation project?

14. Is the remedy functioning as expected (i.e. is the capture zone containing the plume)?

15. Do you have any comments, suggestions, or recommendations regarding the project?

16. What is your overall impression of the project (general sentiment)?

17. In the 2001 Report, URS suggested that nine defects be sealed and one warning sign be replaced. Was this completed and if not, why? Increased frequency of neutron logging to ensure infiltration rates are okay?

18. In the 2001 Report – How are the areas of attainment delineated?

19. No soil moisture data points for one area of attainment…Is this okay? What was the basis for the soil moisture data points?

20. Is there a pass/fail criterion for increased moisture data in the probe locations? If yes, do you know what is the basis / rationale for this criteria?

5/2/03

21. Moisture logs for April 2001 were at 23% and January 1997 data was 10% for 27-29 feet bgs. Is this acceptable? Increased contaminant mobilization? Are all levels/depths reported and reviewed for moisture increases?

22. At what intervals in the monitoring point locations are the soil moisture measured/logged (i.e., every 2 feet)?

23. Why is the soil moisture only reported for 7-8 feet bgs? (highest conc. Generally occurred in the uppermost layer found at approx. 10 feet bgs).

24. The major components of selected remedy per the ROD at OU 7 include:

♦ Posting warning signs regarding presence of contaminated soils that could represent a threat to human health.

The current signs read “Caution: Do not disturb floor. Contact EMR, Phone 7-8790”

Do you think this sign verbiage fulfills the intent of the ROD? Why?

25. Per the PSVP, graphics will be prepared of the concentration at each monitoring well (T-228-001, U7-008, and U7-012) and reported in the annual report. Is this being done?

26. The PSVP states that the Site conceptual model for OU 7 is being reviewed on an annual basis. Is this being done?

27. Review graphs with EMR re: RAO #3.

Appendix E

Changes in Chemical-Specific Clean-up Levels

Comparison of Standards and Cleanup Goals - Hill AFB, FYR 2003 (Evaluated December 2002)

Contaminants GW, SW

Cleanup LevelSoil

Cleanup LevelGW

Protection LevelComments

Based on:MCL and Risk

Based on:GW Protection

Used as Basis for Soil Cleanup Level

ug/L (ppb) ug/L mg/kg ug/L1,1,1-Trichloroethane (1,1,1-TCA) 200 200 10 2001,1,2-Trichloroethane (1,1,2-TCA) 5

1,1-Dichloroethane (1,1-DCA) NA 790 13 630

1,1-DCA toxicity factors on Region 3 RBC Table have not changed since 4/1998 (after ROD).

1,1-Dichloroethene (1,1-DCE) 7 7 0.03 7

1,2,4-Trichlorobenzene (1,2,4-TCB) 70 70 17 701,2-Dichlorobenzene 600 600 60 6001,2-Dichloroethane (1,2-DCA) 5 0.1 5cis 1,2-Dichloroethene (cis 1,2-DCE) 70 70 1.1 70

trans 1,2-Dichloroethene (trans 1,2-DCE) 100

1,4-Dichlorobenzene 75 75 5.8 752,3,7,8-Tetrachlorodibenzo-p-Dioxin (2,3,7,8-TCDD)

0.00003 0.004 0.00003

2,4-Dimethylphenol NA 600 8 300

2,4-Dimethylphenol toxicity factors on Region 3 RBC Table have not changed since 4/1998 (after ROD).

4-Methylphenol (p-cresol) NA 750 3.7 750

p-cresol toxicity factors on Region 3 RBC Table have not changed since 4/1998 (after ROD).

Arsenic 50 (b) 50

Arsenic cleanup level currently valid. However arsenic standard of 10 ug/L (ppb) will be effective in 1/26/2006.

Barium 2000 1000Barium cleanup level is lower than MCL.

Benzene 5 5 0.12 5Benzo(a)pyrene 0.2 21 0.2

Beta-BHC NA

Bis(2-ethylhexyl)phthalate 6

Boron NA

Cadmium 5

Chlorobenzene 100 100 2.4 100Chloroform 100 (d)

Chromium (total) 100 (a)

Chromium (VI) NA (a)

Ethylbenzene 700 11 700

Fluoride 4000 2400Fluoride cleanup level is lower than MCL.

Gamma-BHC (lindane) 0.2Heptachlor epoxide 0.2

Methylene Chloride NA

Methyl Ethyl Ketone NA

Naphthalene NA 1200 22.5 60

Naphthalene RfD(o) decreased from 0.04 to 0.02 mg/kg/d (more stringent), RfD(i) now available: 9.0E-4 mg/kg/d. EPA Region 3 RBC Table 10/2002.

Nickel NA

PCB 0.5 10.1 0.5

Pentachlorophenol 1 0.26 1Selenium 50

1,1,2,2-Tetrachloroethane NA

Tetrachloroethylene(Perchloroethylene, PCE)

5 5 0.52 5

Toluene 1000 1000 43 1000

Trichloroethene (TCE) 5 5 0.17 5

Vinyl Chloride 2 0.03 2xylenes (total) 10,000 1000 10000

References for Cleanup Levels and Risk Factors

OU1

OU1 ROD 1998, Tables 7-1, 7-2. OU1 RI 1995, Appendix A Tables 4-2, 5-3.EPA Region 3 RBC Table 10/2002.

MCLs

Federal40 CFR part 141 (10/10/02)

UtahR309-103 (7/1/02)

CSF - Cancer slope factor, CSF(i) for inhalation, CSF(o) for oralDW - Drinking waterEE/CA - Engineering Evaluation / Cost AnalysisFYR - Five Year ReviewGW - GroundwaterHEAST - Health Effects Assessment Summary TablesIRIS - Integrated Risk Information SystemMCL - Maximum Contaminant LevelNCEA - National Center of Environmental AssessmentRAO - Remedial Action ObjectiveRBC - Risk-based ConcentrationRfD - Reference Dose, RfD(i) for inhalation, RfD(o) for oralRI/FS - Remedial Investigation / Feasibility StudyROD - Record of DecisionSTSC - Superfund Technical Support CenterSW - Surface water

(a) UT drinking water standard only indicates chromium(b) Arsenic standard of 10 ug/L (ppb) will be effective in 1/26/2006.(c) EPA Region 3 and 9 RBCs are based on risk factors in HEAST, IRIS, NCEA, or other EPA sources.(d) MCL for chloroform is for trihalomethanes.(e) OU3 CoCs are based on their potential to leach to groundwater and results in groundwater contaminant concentrations in excess of MCLs, except for PCB-1254 which was based on health risk.

Italicized values are risk based.

Change in MCL or toxicity factor More stringent Less stringent Other

Comparison of Standards and Cleanup Levels 0303141 of 3


Contaminants

1,1,1-Trichloroethane (1,1,1-TCA)1,1,2-Trichloroethane (1,1,2-TCA)

1,1-Dichloroethane (1,1-DCA)

1,1-Dichloroethene (1,1-DCE)

1,2,4-Trichlorobenzene (1,2,4-TCB)1,2-Dichlorobenzene1,2-Dichloroethane (1,2-DCA)cis 1,2-Dichloroethene (cis 1,2-DCE)

trans 1,2-Dichloroethene (trans 1,2-DCE)

1,4-Dichlorobenzene2,3,7,8-Tetrachlorodibenzo-p-Dioxin (2,3,7,8-TCDD)

2,4-Dimethylphenol

4-Methylphenol (p-cresol)

Arsenic

Barium

BenzeneBenzo(a)pyrene

Beta-BHC

Bis(2-ethylhexyl)phthalate

Boron

Cadmium

ChlorobenzeneChloroform

Chromium (total)

Chromium (VI)

Ethylbenzene

Fluoride

Gamma-BHC (lindane)Heptachlor epoxide

Methylene Chloride

Methyl Ethyl Ketone

Naphthalene

Nickel

PCB

PentachlorophenolSelenium

1,1,2,2-Tetrachloroethane


Toluene

Trichloroethene (TCE)

Vinyl Chloridexylenes (total)


GW, SWCleanup Level

SoilCleanup Level

CommentsSoil

Cleanup Level(Berman Pond)

SoilCleanup Level

(RVMF)

GWProtection Level

(Utah MCL, December

1994)

CommentsGW, SW

Cleanup LevelAir

Cleanup LevelComments


Based on:Risk

Based on:GW Protection (e)

Based on:GW Protection

Used as Basis for Soil Cleanup

Level


Based on:Risk

ug/L mg/kg mg/kg mg/kg ug/L ug/L ug/m^3200 4 200

0.04 5

0.08 71,1-DCE MCL that soil cleanup level is based on is still valid.

7

20 6000.03 5 5

70 0.7 70 70

100

2.8 75

4.1 50


50


2,000

0.05 5 50.07 0.2

0.01

Beta-BHC CSF(i) increased from 1.86E-3 to 1.80E+0, 1000x more stringent (EPA Region 3 RBC Table 10/2002).

6 6

2,700Boron RfD(i) now available (EPA Region 3 RBC table 10/2002).

16 5

0.95 100100

0.20.04 0.2

6

Methylene chloride CSF(i) increased from 1.65E-6 to 1.65E-3 (1000x more stringent). EPA Region 3 RBC Table 10/2002.

0.02

Methylene chloride CSF(i) increased from 1.65E-6 to 1.65E-3 (1000x more stringent). EPA Region 3 RBC Table 10/2002.

830

MEK RfD(o) and RfD(i) remain the same (EPA Region 3 RBC Table 10/2002).

100

Nickel RfD(o) remain the same, RfD(i) still not available. (EPA Region 3 RBC Table 10/2002)

0.06

PCB CSF(o) decreased from 7.7 to 2.0 1/mg/kg/d (less stringent), CSF(i) now available: 2.0 1/mg/kg/d. EPA Region 3 RBC Table 10/2002.

50

0.001

No MCL for 1,1,2,2-Tetrachloroethane is available, ROD did not list CSF for comparison. However, there was a change for this compound in the EPA Region 3 RBC Table in Oct 1998.

5 12.31

PCE CSF(i) listed in ROD was 2.03E-072 /mg/kg/d (5.8E-073 1/mg/m^3, possible typo), RBC Table listed 1.0E-2 (more stringent). OU2 ROD, EPA Region 3 RBC Table 10/2002.

5

1000 1,000

5 58.21

TCE inhalation and oral CSFs are more stringent. CSF(i) increased from 1.7E-6 to 4.0E-1 1/mg/kg/d; CSF(o) increased from 1.1E-2 to 4.0E-1 1/mg/kg/d. EPA Region 3 RBC Table 10/2002.

0.07 5 5 5TCE CSF(i) increased from 1.7E-2 to 4.0E-1 1/mg/kg/d (23x more stringent)

0.02 210,000

OU4OU2 OU3

OU3 ROD 1995, Tables 3-5, 4-4, 4-5.Utah MCLs: UT R309-101 to R309-104 1/1/95.EPA Region 3 RBC Table 10/2002.

OU2 ROD 1996, Tables 4-4, 7-1.EPA Region 3 RBC Table 10/2002.

OU4 ROD 1994, Tables 3-4, 3-5, 5-1.EPA Region 3 RBC Table 10/2002.



Contaminants

1,1,1-Trichloroethane (1,1,1-TCA)1,1,2-Trichloroethane (1,1,2-TCA)

1,1-Dichloroethane (1,1-DCA)

1,1-Dichloroethene (1,1-DCE)

1,2,4-Trichlorobenzene (1,2,4-TCB)1,2-Dichlorobenzene1,2-Dichloroethane (1,2-DCA)cis 1,2-Dichloroethene (cis 1,2-DCE)

trans 1,2-Dichloroethene (trans 1,2-DCE)

1,4-Dichlorobenzene2,3,7,8-Tetrachlorodibenzo-p-Dioxin (2,3,7,8-TCDD)

2,4-Dimethylphenol

4-Methylphenol (p-cresol)

Arsenic

Barium

BenzeneBenzo(a)pyrene

Beta-BHC

Bis(2-ethylhexyl)phthalate

Boron

Cadmium

ChlorobenzeneChloroform

Chromium (total)

Chromium (VI)

Ethylbenzene

Fluoride

Gamma-BHC (lindane)Heptachlor epoxide

Methylene Chloride

Methyl Ethyl Ketone

Naphthalene

Nickel

PCB

PentachlorophenolSelenium

1,1,2,2-Tetrachloroethane


Toluene

Trichloroethene (TCE)

Vinyl Chloridexylenes (total)


GW, SWCleanup Level

CommentsGW, SW

Cleanup LevelSoil


SoilCleanup Level

CommentsGW


Based on:MCL

Based on:Risk

Based on:Risk

Based on:MCL

ug/L mg/kg mg/kg ug/L200

0.026

1,1-DCE has been reclassified as non-cancerous (EPA Region 3 RBC table 10/2002).

7

5

50


5

7.57

Cadmium toxicity factors remain the same (EPA Region 3 RBC Table 10/2002).

100

50Chromium cleanup level is lower than MCL.

1.16

Chromium(VI) RfD(i) decreased from 5E-3 to 3E-5 (100x more stringent) at OU7 (EPA Region 3 RBC Table 10/2002).

50Chromium (VI) cleanup level is lower than MCL.

5

x

RAO required aerial decrease of TCE plume. No numerical remedial goal was set, only discharge compliance was specified.

5 5

OU5 EE/CA 1994

OU8OU5 OU6 OU7

OU6 ROD 1997, pgs 4-10, 7-1. Tables 4-2.EPA Region 3 RBC Table 10/2002.

OU7 ROD 1995, Table 5-1.OU7 RI/FS 1995, Tables 6-8 to 6-19, 6-30.EPA Region 3 RBC Table 10/2002.

OU8 ROD 1997 (Interim), Table 3-1.


EPA Region III RBC Table 10/9/2002 1

Sources: I = IRIS H = HEAST A = HEAST Alternate W = Withdrawn from IRIS or HEAST Basis: C = Carcinogenic effects N = Noncarcinogenic effects ! = RBC at HI of 0.1 < RBC-c

E = EPA-NCEA provisional value O = other Risk-based concentrations Region III SSLsTap Ambient Soil Soil, for groundwater migration

RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgACETALDEHYDE 75070 2.57E-003 I 7.7E-003 I y 1.6E+000 C 8.1E-001 C 3.8E-004 7.7E-003 CACETOCHLOR 34256821 2E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NACETONE 67641 1.00E-001 I y 6.1E+002 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 1.2E-001 2.5E+000 NACETONITRILE 75058 1.7E-002 I y 1.2E+002 N 6.2E+001 N 2.9E-002 5.8E-001 NACETOPHENONE 98862 1.00E-001 I 5.70E-006 W y 4.2E-002 N 2.1E-002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 1.1E-005 2.2E-004 NACROLEIN 107028 2.00E-002 H 5.70E-006 I y 4.2E-002 N 2.1E-002 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 1.0E-005 2.0E-004 NACRYLAMIDE 79061 2.00E-004 I 4.50E+000 I 4.50E+000 I 1.5E-002 C 1.4E-003 C 7.0E-004 C 1.3E+000 C 1.4E-001 C 3.7E-006 7.4E-005 CACRYLONITRILE 107131 1.00E-003 H 5.40E-001 I 5.70E-004 I 2.40E-001 I y 3.7E-002 C 2.6E-002 C 5.8E-003 C 1.1E+001 C 1.2E+000 C 7.4E-006 1.5E-004 CALACHLOR 15972608 1.00E-002 I 8.00E-002 H 8.4E-001 C 7.8E-002 C 3.9E-002 C 7.2E+001 C 8.0E+000 C 3.5E-004 7.0E-003 CALAR 1596845 1.50E-001 I 5.5E+003 N 5.5E+002 N 2.0E+002 N 3.1E+005 N 1.2E+004 NALDICARB 116063 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 N 1.0E-002 2.1E-001 NALDICARB SULFONE 1646884 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 N 7.5E-003 1.5E-001 NALDRIN 309002 3.00E-005 I 1.70E+001 I 1.70E+001 I 3.9E-003 C 3.7E-004 C 1.9E-004 C 3.4E-001 C 3.8E-002 C 3.8E-004 7.7E-003 CALUMINUM 7429905 1.00E+000 E 1.00E-003 E 3.7E+004 N 3.7E+000 N 1.4E+003 N 2.0E+006 N 7.8E+004 NAMINODINITROTOLUENES 6.00E-005 E 2.2E+000 N 2.2E-001 N 8.1E-002 N 1.2E+002 N 4.7E+000 N4-AMINOPYRIDINE 504245 2.00E-005 H 7.3E-001 N 7.3E-002 N 2.7E-002 N 4.1E+001 N 1.6E+000 NAMMONIA 7664417 2.86E-002 I y 2.1E+002 N 1.0E+002 N ANILINE 62533 7.00E-003 E 5.70E-003 I 2.90E-004 I 1.2E+001 C 1.1E+000 N 5.5E-001 C 1.0E+003 C 1.1E+002 C ! 6.8E-003 1.4E-001 CANTIMONY 7440360 4.00E-004 I 1.5E+001 N 1.5E+000 N 5.4E-001 N 8.2E+002 N 3.1E+001 N 6.6E-001 1.3E+001 NANTIMONY PENTOXIDE 1314609 5.00E-004 H 1.8E+001 N 1.8E+000 N 6.8E-001 N 1.0E+003 N 3.9E+001 NANTIMONY TETROXIDE 1332816 4.00E-004 H 1.5E+001 N 1.5E+000 N 5.4E-001 N 8.2E+002 N 3.1E+001 NANTIMONY TRIOXIDE 1309644 4.00E-004 H 5.70E-005 I 1.5E+001 N 2.1E-001 N 5.4E-001 N 8.2E+002 N 3.1E+001 NARSENIC 7440382 3.00E-004 I 1.50E+000 I 1.51E+001 I 4.5E-002 C 4.1E-004 C 2.1E-003 C 3.8E+000 C 4.3E-001 C 1.3E-003 2.6E-002 CARSINE 7784421 1.40E-005 I y 1.0E-001 N 5.1E-002 N ASSURE 76578148 9.00E-003 I 3.3E+002 N 3.3E+001 N 1.2E+001 N 1.8E+004 N 7.0E+002 NATRAZINE 1912249 3.50E-002 I 2.20E-001 H 3.0E-001 C 2.8E-002 C 1.4E-002 C 2.6E+001 C 2.9E+000 C 4.4E-004 8.8E-003 CAZOBENZENE 103333 1.10E-001 I 1.10E-001 I 6.1E-001 C 5.7E-002 C 2.9E-002 C 5.2E+001 C 5.8E+000 C 1.8E-003 3.5E-002 CBARIUM 7440393 7.00E-002 I 1.40E-004 A 2.6E+003 N 5.1E-001 N 9.5E+001 N 1.4E+005 N 5.5E+003 N 1.1E+002 2.1E+003 NBAYGON 114261 4.00E-003 I 1.5E+002 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 NBAYTHROID 68359375 2.50E-002 I 9.1E+002 N 9.1E+001 N 3.4E+001 N 5.1E+004 N 2.0E+003 NBENTAZON 25057890 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 NBENZALDEHYDE 100527 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NBENZENE 71432 3.00E-003 E 5.5E-002 I 1.70E-003 E 2.90E-002 I y 3.2E-001 C 2.2E-001 C 5.7E-002 C 1.0E+002 C 1.2E+001 C 9.0E-005 1.8E-003 CBENZENETHIOL 108985 1.00E-005 H y 6.1E-002 N 3.7E-002 N 1.4E-002 N 2.0E+001 N 7.8E-001 NBENZIDINE 92875 3.00E-003 I 2.30E+002 I 2.30E+002 I 2.9E-004 C 2.7E-005 C 1.4E-005 C 2.5E-002 C 2.8E-003 CBENZOIC ACID 65850 4.00E+000 I 1.5E+005 N 1.5E+004 N 5.4E+003 N 8.2E+006 N 3.1E+005 NBENZYL ALCOHOL 100516 3.00E-001 H 1.1E+004 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 4.4E+000 8.8E+001 NBENZYL CHLORIDE 100447 0.17 I y 6.2E-002 C 3.7E-002 C 1.9E-002 C 3.4E+001 C 3.8E+000 C 1.9E-005 3.7E-004 CBERYLLIUM 7440417 2.00E-003 I 5.7E-006 I 8.40E+000 I 7.3E+001 N 7.5E-004 C 2.7E+000 N 4.1E+003 N 1.6E+002 N 5.8E+001 1.2E+003 NBIPHENYL 92524 5.00E-002 I y 3.0E+002 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N 4.8E+000 9.6E+001 NBIS(2-CHLOROETHYL)ETHER 111444 1.10E+000 I 1.10E+000 I y 9.6E-003 C 5.7E-003 C 2.9E-003 C 5.2E+000 C 5.8E-001 C 2.2E-006 4.4E-005 CBIS(2-CHLOROISOPROPYL)ETHER 108601 4.00E-002 I 7.00E-002 H 3.50E-002 H y 2.6E-001 C 1.8E-001 C 4.5E-002 C 8.2E+001 C 9.1E+000 C 8.4E-005 1.7E-003 CBIS(CHLOROMETHYL)ETHER 542881 2.20E+002 I 2.20E+002 I y 4.8E-005 C 2.8E-005 C 1.4E-005 C 2.6E-002 C 2.9E-003 C 9.7E-009 1.9E-007 CBIS(2-ETHYLHEXYL)PHTHALATE 117817 2.00E-002 I 1.40E-002 I 1.40E-002 E 4.8E+000 C 4.5E-001 C 2.3E-001 C 4.1E+002 C 4.6E+001 C 1.4E+002 2.9E+003 CBORON 7440428 9.00E-002 I 5.70E-003 H 3.3E+003 N 2.1E+001 N 1.2E+002 N 1.8E+005 N 7.0E+003 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgBROMODICHLOROMETHANE 75274 2.00E-002 I 6.20E-002 I y 1.7E-001 C 1.0E-001 C 5.1E-002 C 9.2E+001 C 1.0E+001 C 5.4E-005 1.1E-003 CBROMOETHENE 593602 8.6E-004 I 1.10E-001 H y 1.1E-001 C 5.7E-002 C 5.4E-005 1.1E-003 CBROMOFORM 75252 2.00E-002 I 7.90E-003 I 3.90E-003 I 8.5E+000 C 1.6E+000 C 4.0E-001 C 7.2E+002 C 8.1E+001 C 3.3E-003 6.7E-002 CBROMOMETHANE 74839 1.40E-003 I 1.40E-003 I y 8.5E+000 N 5.1E+000 N 1.9E+000 N 2.9E+003 N 1.1E+002 N 2.1E-003 4.1E-002 NBROMOPHOS 2104963 5.00E-003 H 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N1,3-BUTADIENE 106990 1.80E+000 H y 7.0E-003 C 3.5E-003 C 3.9E-006 7.8E-005 C1-BUTANOL 71363 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 7.8E-001 1.6E+001 NBUTYLBENZYLPHTHALATE 85687 2.00E-001 I 7.3E+003 N 7.3E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 N 8.4E+002 1.7E+004 NBUTYLATE 2008415 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NN-BUTYLBENZENE 104518 4.00E-002 E y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NSEC-BUTYLBENZENE 135988 4.00E-002 E y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NTERT-BUTYLBENZENE 98066 4.00E-002 E y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NCADMIUM-WATER 7440439 5.00E-004 I 5.7E-005 E 6.30E+000 I 1.8E+001 N 9.9E-004 C 6.8E-001 N 1.0E+003 N 3.9E+001 N 1.4E+000 2.7E+001 NCADMIUM-FOOD 7440439 1.00E-003 I 5.7E-005 E 6.30E+000 I 3.7E+001 N 9.9E-004 C 1.4E+000 N 2.0E+003 N 7.8E+001 N 2.7E+000 5.5E+001 NCAPROLACTAM 105602 5.00E-001 I 1.8E+004 N 1.8E+003 N 6.8E+002 N 1.0E+006 N 3.9E+004 NCARBARYL 63252 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 1.5E+000 3.0E+001 NCARBON DISULFIDE 75150 1.00E-001 I 2.00E-001 I y 1.0E+003 N 7.3E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 9.5E-001 1.9E+001 NCARBON TETRACHLORIDE 56235 7.00E-004 I 1.30E-001 I 5.71E-004 E 5.30E-002 I y 1.6E-001 C 1.2E-001 C 2.4E-002 C 4.4E+001 C 4.9E+000 C 1.1E-004 2.1E-003 CCARBOSULFAN 55285148 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NCHLORAL HYDRATE 302170 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NCHLORANIL 118752 4.00E-001 H 1.7E-001 C 1.6E-002 C 7.9E-003 C 1.4E+001 C 1.6E+000 CCHLORDANE 57749 5.00E-004 I 3.5E-001 I 2.00E-004 I 3.5E-001 I 1.9E-001 C 1.8E-002 C 9.0E-003 C 1.6E+001 C 1.8E+000 C 4.6E-002 9.2E-001 CCHLORINE 7782505 1.00E-001 I 5.7E-005 E y 4.2E-001 N 2.1E-001 N 1.4E+002 N 2.0E+005 N 7.8E+003 NCHLORINE DIOXIDE 10049044 3.00E-002 I 5.70E-005 I y 4.2E-001 N 2.1E-001 N 4.1E+001 N 6.1E+004 N 2.3E+003 NCHLOROACETIC ACID 79118 2.00E-003 H 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N4-CHLOROANILINE 106478 4.00E-003 I 1.5E+002 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 N 4.8E-002 9.7E-001 NCHLOROBENZENE 108907 2.00E-002 I 1.7E-002 E y 1.1E+002 N 6.2E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 4.0E-002 8.0E-001 NCHLOROBENZILATE 510156 2.00E-002 I 2.70E-001 H 2.70E-001 H 2.5E-001 C 2.3E-002 C 1.2E-002 C 2.1E+001 C 2.4E+000 C 1.3E-003 2.7E-002 CP-CHLOROBENZOIC ACID 74113 2.00E-001 H 7.3E+003 N 7.3E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 N2-CHLORO-1,3-BUTADIENE 126998 2.00E-002 A 2.00E-003 H y 1.4E+001 N 7.3E+000 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 6.0E-003 1.2E-001 N1-CHLOROBUTANE 109693 4.00E-001 H y 2.4E+003 N 1.5E+003 N 5.4E+002 N 8.2E+005 N 3.1E+004 N 1.0E+000 2.0E+001 N1-CHLORO-1,1-DIFLUOROETHANE 75683 1.40E+001 I y 1.0E+005 N 5.1E+004 N 7.0E+001 1.4E+003 NCHLORODIFLUOROMETHANE 75456 1.40E+001 I y 1.0E+005 N 5.1E+004 N 7.0E+001 1.4E+003 NCHLOROETHANE 75003 4.00E-001 E 2.90E-003 E 2.90E+000 I y 3.6E+000 C 2.2E+000 C 1.1E+000 C 2.0E+003 C 2.2E+002 C 9.6E-004 1.9E-002 CCHLOROFORM 67663 1.00E-002 I 8.6E-005 E 8.10E-002 I y 1.5E-001 C ! 7.7E-002 C ! 1.4E+001 N 2.0E+004 N 7.8E+002 N 4.5E-005 9.1E-004 CCHLOROMETHANE 74873 1.30E-002 H 2.6E-002 I 3.5E-003 E y 2.1E+000 C 1.8E+000 C 2.4E-001 C 4.4E+002 C 4.9E+001 C 5.2E-004 1.0E-002 C4-CHLORO-2-METHYLANILINE 95692 5.80E-001 H 1.2E-001 C 1.1E-002 C 5.4E-003 C 9.9E+000 C 1.1E+000 CBETA-CHLORONAPHTHALENE 91587 8.00E-002 I y 4.9E+002 N 2.9E+002 N 1.1E+002 N 1.6E+005 N 6.3E+003 N 1.6E+000 3.2E+001 NO-CHLORONITROBENZENE 88733 2.50E-002 H y 4.2E-001 C 2.5E-001 C 1.3E-001 C 2.3E+002 C 2.6E+001 CP-CHLORONITROBENZENE 100005 1.80E-002 H y 5.9E-001 C 3.5E-001 C 1.8E-001 C 3.2E+002 C 3.5E+001 C2-CHLOROPHENOL 95578 5.00E-003 I y 3.0E+001 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N2-CHLOROPROPANE 75296 2.90E-002 H y 2.1E+002 N 1.1E+002 N 6.6E-002 1.3E+000 NO-CHLOROTOLUENE 95498 2.00E-002 I y 1.2E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 6.5E-002 1.3E+000 NCHLORPYRIFOS 2921882 3.00E-003 I 1.1E+002 N 1.1E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 N 3.2E+000 6.3E+001 NCHLORPYRIFOS-METHYL 5598130 1.00E-002 H 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgCHROMIUM III 16065831 1.50E+000 I 5.5E+004 N 5.5E+003 N 2.0E+003 N 3.1E+006 N 1.2E+005 N 9.9E+007 2.0E+009 NCHROMIUM VI 18540299 3.00E-003 I 3.00E-005 I 4.10E+001 H 1.1E+002 N 1.5E-004 C 4.1E+000 N 6.1E+003 N 2.3E+002 N 2.1E+000 4.2E+001 NCOBALT 7440484 2.00E-002 E 5.7E-006 E 7.3E+002 N 2.1E-002 N 2.7E+001 N 4.1E+004 N 1.6E+003 NCOKE OVEN EMISSIONS (COAL TAR) 8007452 2.2 I 2.8E-003 C COPPER 7440508 4.00E-002 H 1.5E+003 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 N 5.3E+002 1.1E+004 NCROTONALDEHYDE 123739 1.90E+000 H y 5.6E-003 C 3.3E-003 C 1.7E-003 C 3.0E+000 C 3.4E-001 C 1.5E-005 3.1E-004 CCUMENE 98828 1.00E-001 I 1.10E-001 I y 6.6E+002 N 4.0E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 3.2E+000 6.4E+001 NCYANIDE (FREE) 57125 2.00E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 7.4E+000 1.5E+002 NCALCIUM CYANIDE 592018 4E-002 I 1.5E+003 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NCOPPER CYANIDE 544923 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NCYANAZINE 21725462 2.00E-003 H 8.40E-001 H 8.0E-002 C 7.5E-003 C 3.8E-003 C 6.8E+000 C 7.6E-001 C 2.6E-005 5.3E-004 CCYANOGEN 460195 4.00E-002 I y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NCYANOGEN BROMIDE 506683 9.00E-002 I 3.3E+003 N 3.3E+002 N 1.2E+002 N 1.8E+005 N 7.0E+003 NCYANOGEN CHLORIDE 506774 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NHYDROGEN CYANIDE 74908 2.00E-002 I 8.60E-004 I y 6.2E+000 N 3.1E+000 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 1.1E-001 2.2E+000 NPOTASSIUM CYANIDE 151508 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NPOTASSIUM SILVER CYANIDE 506616 2.00E-001 I 7.3E+003 N 7.3E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 NSILVER CYANIDE 506649 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 3.1E+001 6.2E+002 NSODIUM CYANIDE 143339 4.00E-002 I 1.5E+003 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NTHIOCYANATE 5.00E-002 E 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NZINC CYANIDE 557211 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N 1.1E+002 2.3E+003 NCYCLOHEXANONE 108941 5.00E+000 I 1.8E+005 N 1.8E+004 N 6.8E+003 N 1.0E+007 N 3.9E+005 N 6.1E+001 1.2E+003 NCYHALOTHRIN/KARATE 68085858 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NCYPERMETHRIN 52315078 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NDACTHAL 1861321 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NDALAPON 75990 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N 3.5E-001 7.1E+000 NDDD 72548 2.40E-001 I 2.8E-001 C 2.6E-002 C 1.3E-002 C 2.4E+001 C 2.7E+000 C 5.6E-001 1.1E+001 CDDE 72559 3.40E-001 I 2.0E-001 C 1.8E-002 C 9.3E-003 C 1.7E+001 C 1.9E+000 C 1.8E+000 3.5E+001 CDDT 50293 5.00E-004 I 3.40E-001 I 3.40E-001 I 2.0E-001 C 1.8E-002 C 9.3E-003 C 1.7E+001 C 1.9E+000 C 5.8E-002 1.2E+000 CDIAZINON 333415 9.00E-004 H 3.3E+001 N 3.3E+000 N 1.2E+000 N 1.8E+003 N 7.0E+001 N 2.1E-002 4.3E-001 NDIBENZOFURAN 132649 4.00E-003 E y 2.4E+001 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 N 3.8E-001 7.7E+000 N1,4-DIBROMOBENZENE 106376 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NDIBROMOCHLOROMETHANE 124481 2.00E-002 I 8.40E-002 I y 1.3E-001 C 7.5E-002 C 3.8E-002 C 6.8E+001 C 7.6E+000 C 4.1E-005 8.3E-004 C1,2-DIBROMO-3-CHLOROPROPANE 96128 1.40E+000 H 5.70E-005 I 2.40E-003 H y 4.7E-002 C ! 2.1E-001 N 2.3E-003 C 4.1E+000 C 4.6E-001 C 4.4E-005 8.7E-004 C1,2-DIBROMOETHANE 106934 8.50E+001 I 5.70E-005 H 7.60E-001 I y 7.5E-004 C 8.2E-003 C 3.7E-005 C 6.7E-002 C 7.5E-003 C 4.3E-007 8.5E-006 CDIBUTYLPHTHALATE 84742 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 2.5E+002 5.0E+003 NDICAMBA 1918009 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N 2.2E-001 4.5E+000 N1,2-DICHLOROBENZENE 95501 9.00E-002 I 4.00E-002 H y 2.7E+002 N 1.5E+002 N 1.2E+002 N 1.8E+005 N 7.0E+003 N 2.3E-001 4.6E+000 N1,3-DICHLOROBENZENE 541731 3.00E-002 E y 1.8E+002 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N 1.5E-001 2.9E+000 N1,4-DICHLOROBENZENE 106467 3.00E-002 E 2.40E-002 H 2.29E-001 I 2.2E-002 E y 4.7E-001 C 2.8E-001 C 1.3E-001 C 2.4E+002 C 2.7E+001 C 3.6E-004 7.1E-003 C3,3'-DICHLOROBENZIDINE 91941 4.50E-001 I 1.5E-001 C 1.4E-002 C 7.0E-003 C 1.3E+001 C 1.4E+000 C 2.5E-004 4.9E-003 C1,4-DICHLORO-2-BUTENE 764410 9.30E+000 H y 1.3E-003 C 6.7E-004 C 4.0E-007 8.0E-006 CDICHLORODIFLUOROMETHANE 75718 2.00E-001 I 5.00E-002 A y 3.5E+002 N 1.8E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 N 5.5E-001 1.1E+001 N1,1-DICHLOROETHANE 75343 1.00E-001 H 1.40E-001 A y 8.0E+002 N 5.1E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 2.3E-001 4.5E+000 N1,2-DICHLOROETHANE 107062 3.00E-002 E 9.10E-002 I 1.40E-003 E 9.10E-002 I y 1.2E-001 C 6.9E-002 C 3.5E-002 C 6.3E+001 C 7.0E+000 C 5.2E-005 1.0E-003 C




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kg**1,1-DICHLOROETHENE 75354 5.00E-002 I 6.00E-002 I y 3.5E+002 N 2.2E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N 1.5E-001 2.9E+000 NCIS-1,2-DICHLOROETHENE 156592 1.00E-002 H y 6.1E+001 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N 1.7E-002 3.5E-001 NTRANS-1,2-DICHLOROETHENE 156605 2.00E-002 I y 1.2E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 4.1E-002 8.2E-001 NTOTAL 1,2-DICHLOROETHENE 540590 9.00E-003 H y 5.5E+001 N 3.3E+001 N 1.2E+001 N 1.8E+004 N 7.0E+002 N 1.9E-002 3.7E-001 N2,4-DICHLOROPHENOL 120832 3.00E-003 I 1.1E+002 N 1.1E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 N 6.0E-002 1.2E+000 N2,4-D 94757 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N 4.5E-001 9.0E+000 N4-(2,4-DICHLOROPHENOXY)BUTYRIC ACID 94826 8E-003 I 2.9E+002 N 2.9E+001 N 1.1E+001 N 1.6E+004 N 6.3E+002 N1,2-DICHLOROPROPANE 78875 6.80E-002 H 1.14E-003 I y 1.6E-001 C 9.2E-002 C 4.6E-002 C 8.4E+001 C 9.4E+000 C 1.0E-004 2.1E-003 C2,3-DICHLOROPROPANOL 616239 3.00E-003 I 1.1E+002 N 1.1E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 N1,3-DICHLOROPROPENE 542756 3.00E-002 I 1.00E-001 I 5.71E-003 I 1.00E-002 I y 4.4E-001 C 6.3E-001 C 3.2E-002 C 5.7E+001 C 6.4E+000 C 1.6E-004 3.1E-003 CDICHLORVOS 62737 5E-004 I 0.29 I 1.43E-004 I 2.3E-001 C 2.2E-002 C 1.1E-002 C 2.0E+001 C 2.2E+000 C 5.5E-005 1.1E-003 CDICOFOL 115322 4.4E-001 W 1.5E-001 C 1.4E-002 C 7.2E-003 C 1.3E+001 C 1.5E+000 C 9.3E-004 1.9E-002 CDICYCLOPENTADIENE 77736 3E-002 H 6.00E-005 A y 4.4E-001 N 2.2E-001 N 4.1E+001 N 6.1E+004 N 2.3E+003 NDIELDRIN 60571 5.00E-005 I 1.60E+001 I 1.60E+001 I 4.2E-003 C 3.9E-004 C 2.0E-004 C 3.6E-001 C 4.0E-002 C 1.1E-004 2.2E-003 CDIESEL EMISSIONS 1.40E-003 I 5.1E+000 N DIETHYLPHTHALATE 84662 8.00E-001 I 2.9E+004 N 2.9E+003 N 1.1E+003 N 1.6E+006 N 6.3E+004 N 2.3E+001 4.5E+002 NDIETHYLENE GLYCOL, MONOBUTYL ETHER 112345 5.70E-003 H 2.1E+001 N DIETHYLENE GLYCOL, MONOETHYL ETHER 111900 2.00E+000 H 7.3E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 NDI(2-ETHYLHEXYL)ADIPATE 103231 6.00E-001 I 1.20E-003 I 5.6E+001 C 5.2E+000 C 2.6E+000 C 4.8E+003 C 5.3E+002 CDIETHYLSTILBESTROL 56531 4.70E+003 H 1.4E-005 C 1.3E-006 C 6.7E-007 C 1.2E-003 C 1.4E-004 CDIFENZOQUAT (AVENGE) 43222486 8.00E-002 I 2.9E+003 N 2.9E+002 N 1.1E+002 N 1.6E+005 N 6.3E+003 N1,1-DIFLUOROETHANE 75376 1.10E+001 I y 8.0E+004 N 4.0E+004 N DIISOPROPYL METHYLPHOSPHONATE (DIMP) 1445756 8.00E-002 I 2.9E+003 N 2.9E+002 N 1.1E+002 N 1.6E+005 N 6.3E+003 N3,3'-DIMETHOXYBENZIDINE 119904 1.40E-002 H 4.8E+000 C 4.5E-001 C 2.3E-001 C 4.1E+002 C 4.6E+001 CDIMETHYLAMINE 124403 5.70E-006 W y 4.2E-002 N 2.1E-002 N 8.5E-006 1.7E-004 N2,4-DIMETHYLANILINE HYDROCHLORIDE 21436964 5.80E-001 H 1.2E-001 C 1.1E-002 C 5.4E-003 C 9.9E+000 C 1.1E+000 C2,4-DIMETHYLANILINE 95681 7.50E-001 H 8.9E-002 C 8.3E-003 C 4.2E-003 C 7.6E+000 C 8.5E-001 CN,N-DIMETHYLANILINE 121697 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N3,3'-DIMETHYLBENZIDINE 119937 9.20E+000 H 7.3E-003 C 6.8E-004 C 3.4E-004 C 6.2E-001 C 6.9E-002 C1,1-DIMETHYLHYDRAZINE 57147 2.60E+000 W 3.50E+000 W 2.6E-002 C 1.8E-003 C 1.2E-003 C 2.2E+000 C 2.5E-001 C1,2-DIMETHYLHYDRAZINE 540738 3.70E+001 W 3.70E+001 W 1.8E-003 C 1.7E-004 C 8.5E-005 C 1.5E-001 C 1.7E-002 C2,4-DIMETHYLPHENOL 105679 2.00E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 3.4E-001 6.7E+000 N2,6-DIMETHYLPHENOL 576261 6.00E-004 I 2.2E+001 N 2.2E+000 N 8.1E-001 N 1.2E+003 N 4.7E+001 N3,4-DIMETHYLPHENOL 95658 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 NDIMETHYLPHTHALATE 131113 1.00E+001 W 3.7E+005 N 3.7E+004 N 1.4E+004 N 2.0E+007 N 7.8E+005 N1,2-DINITROBENZENE 528290 4.00E-004 H 1.5E+001 N 1.5E+000 N 5.4E-001 N 8.2E+002 N 3.1E+001 N1,3-DINITROBENZENE 99650 1.00E-004 I 3.7E+000 N 3.7E-001 N 1.4E-001 N 2.0E+002 N 7.8E+000 N 1.8E-003 3.7E-002 N1,4-DINITROBENZENE 100254 4.00E-004 H 1.5E+001 N 1.5E+000 N 5.4E-001 N 8.2E+002 N 3.1E+001 N4,6-DINITRO-O-CYCLOHEXYL PHENOL 131895 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N**4,6-DINITRO-2-METHYLPHENOL 534521 1.00E-004 E 3.7E+000 N 3.7E-001 N 1.4E-001 N 2.0E+002 N 7.8E+000 N2,4-DINITROPHENOL 51285 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 NDINITROTOLUENE MIX 6.80E-001 I 9.8E-002 C 9.2E-003 C 4.6E-003 C 8.4E+000 C 9.4E-001 C2,4-DINITROTOLUENE 121142 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N 2.9E-002 5.7E-001 N2,6-DINITROTOLUENE 606202 1.00E-003 H 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 N 1.2E-002 2.5E-001 NDINOSEB 88857 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 N 8.7E-003 1.7E-001 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgDIOCTYLPHTHALATE 117840 2.00E-002 H 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 1.2E+005 2.4E+006 N1,4-DIOXANE 123911 1.10E-002 I 6.1E+000 C 5.7E-001 C 2.9E-001 C 5.2E+002 C 5.8E+001 C 1.3E-003 2.6E-002 CDIPHENYLAMINE 122394 2.50E-002 I 9.1E+002 N 9.1E+001 N 3.4E+001 N 5.1E+004 N 2.0E+003 N 1.3E+000 2.5E+001 N1,2-DIPHENYLHYDRAZINE 122667 8.00E-001 I 8.00E-001 I 8.4E-002 C 7.8E-003 C 3.9E-003 C 7.2E+000 C 8.0E-001 C 1.3E-004 2.5E-003 CDIQUAT 85007 2.20E-003 I 8.0E+001 N 8.0E+000 N 3.0E+000 N 4.5E+003 N 1.7E+002 N 1.7E-002 3.3E-001 NDISULFOTON 298044 4.00E-005 I 1.5E+000 N 1.5E-001 N 5.4E-002 N 8.2E+001 N 3.1E+000 N 3.2E-003 6.4E-002 N1,4-DITHIANE 505293 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NDIURON 330541 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N 5.8E-002 1.2E+000 NENDOSULFAN 115297 6.00E-003 I 2.2E+002 N 2.2E+001 N 8.1E+000 N 1.2E+004 N 4.7E+002 N 9.8E-001 2.0E+001 NENDRIN 72208 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N 2.7E-001 5.4E+000 NEPICHLOROHYDRIN 106898 2.00E-003 H 9.90E-003 I 2.86E-004 I 4.20E-003 I y 2.0E+000 N 1.0E+000 N 3.2E-001 C ! 5.8E+002 C ! 6.5E+001 C ! 4.2E-004 8.4E-003 NETHION 563122 5.00E-004 I 1.8E+001 N 1.8E+000 N 6.8E-001 N 1.0E+003 N 3.9E+001 N 3.2E-001 6.4E+000 N2-ETHOXYETHANOL 110805 4.00E-001 H 5.70E-002 I 1.5E+004 N 2.1E+002 N 5.4E+002 N 8.2E+005 N 3.1E+004 N 3.3E+000 6.5E+001 NETHYL ACETATE 141786 9.00E-001 I y 5.5E+003 N 3.3E+003 N 1.2E+003 N 1.8E+006 N 7.0E+004 N 1.7E+000 3.5E+001 NETHYLBENZENE 100414 1.00E-001 I 2.90E-001 I 3.85E-003 E y 3.3E+000 C 1.6E+000 C 1.4E+002 N 2.0E+005 N 7.8E+003 N 1.8E-003 3.6E-002 CETHYLENE DIAMINE 107153 2.00E-002 H 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NETHYLENE GLYCOL 107211 2.00E+000 I 7.3E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 N 1.5E+001 3.0E+002 NETHYLENE GLYCOL, MONOBUTYL ETHER 111762 5.00E-001 I 3.70E+000 I 1.8E+004 N 1.4E+004 N 6.8E+002 N 1.0E+006 N 3.9E+004 NETHYLENE OXIDE 75218 1.00E+000 H 3.50E-001 H y 2.3E-002 C 1.8E-002 C 3.2E-003 C 5.7E+000 C 6.4E-001 C 4.8E-006 9.5E-005 CETHYLENE THIOUREA 96457 8.00E-005 I 1.1E-001 H 6.1E-001 C ! 5.7E-002 C ! 2.9E-002 C ! 5.2E+001 C ! 5.8E+000 C !ETHYL ETHER 60297 2.00E-001 I y 1.2E+003 N 7.3E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 N 4.2E-001 8.5E+000 NETHYL METHACRYLATE 97632 9.00E-002 H y 5.5E+002 N 3.3E+002 N 1.2E+002 N 1.8E+005 N 7.0E+003 N 1.0E+000 2.1E+001 NFENAMIPHOS 22224926 2.50E-004 I 9.1E+000 N 9.1E-001 N 3.4E-001 N 5.1E+002 N 2.0E+001 N 7.8E-003 1.6E-001 NFLUOMETURON 2164172 1.30E-002 I 4.7E+002 N 4.7E+001 N 1.8E+001 N 2.7E+004 N 1.0E+003 NFLUORINE 7782414 6.00E-002 I 2.2E+003 N 2.2E+002 N 8.1E+001 N 1.2E+005 N 4.7E+003 NFOMESAFEN 72178020 1.90E-001 I 3.5E-001 C 3.3E-002 C 1.7E-002 C 3.0E+001 C 3.4E+000 CFONOFOS 944229 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 N 1.8E-001 3.5E+000 NFORMALDEHYDE 50000 2.00E-001 I 4.50E-002 I 7.3E+003 N 1.4E-001 C 2.7E+002 N 4.1E+005 N 1.6E+004 N 1.5E+000 3.0E+001 NFORMIC ACID 64186 2.00E+000 H 7.3E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 NFURAN 110009 1.00E-003 I y 6.1E+000 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 N 1.5E-003 3.0E-002 NFURAZOLIDONE 67458 3.80E+000 H 1.8E-002 C 1.6E-003 C 8.3E-004 C 1.5E+000 C 1.7E-001 CFURFURAL 98011 3.00E-003 I 1.00E-002 A 1.1E+002 N 3.7E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 N 2.3E-002 4.6E-001 NGLYCIDALDEHYDE 765344 4.00E-004 I 2.90E-004 H 1.5E+001 N 1.1E+000 N 5.4E-001 N 8.2E+002 N 3.1E+001 NGLYPHOSATE 1071836 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N 2.6E+001 5.3E+002 NHEPTACHLOR 76448 5.00E-004 I 4.50E+000 I 4.50E+000 I 1.5E-002 C 1.4E-003 C 7.0E-004 C 1.3E+000 C 1.4E-001 C 4.2E-002 8.4E-001 CHEPTACHLOR EPOXIDE 1024573 1.30E-005 I 9.10E+000 I 9.10E+000 I 7.4E-003 C 6.9E-004 C 3.5E-004 C 6.3E-001 C 7.0E-002 C 1.2E-003 2.5E-002 CHEXABROMOBENZENE 87821 2.00E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 NHEXACHLOROBENZENE 118741 8.00E-004 I 1.60E+000 I 1.60E+000 I 4.2E-002 C 3.9E-003 C 2.0E-003 C 3.6E+000 C 4.0E-001 C 2.6E-003 5.2E-002 CHEXACHLOROBUTADIENE 87683 2.00E-004 H 7.80E-002 I 7.80E-002 I 8.6E-001 C ! 8.0E-002 C ! 4.0E-002 C ! 7.3E+001 C ! 8.2E+000 C ! 9.2E-002 1.8E+000 CALPHA-HCH 319846 6.30E+000 I 6.30E+000 I 1.1E-002 C 9.9E-004 C 5.0E-004 C 9.1E-001 C 1.0E-001 C 4.5E-005 8.9E-004 CBETA-HCH 319857 1.80E+000 I 1.80E+000 I 3.7E-002 C 3.5E-003 C 1.8E-003 C 3.2E+000 C 3.5E-001 C 1.6E-004 3.1E-003 CGAMMA-HCH (LINDANE) 58899 3.00E-004 I 1.30E+000 H 5.2E-002 C 4.8E-003 C 2.4E-003 C 4.4E+000 C 4.9E-001 C 2.2E-004 4.3E-003 CTECHNICAL HCH 608731 1.80E+000 I 1.80E+000 I 3.7E-002 C 3.5E-003 C 1.8E-003 C 3.2E+000 C 3.5E-001 CHEXACHLOROCYCLOPENTADIENE 77474 6.00E-003 I 5.7E-005 I 2.2E+002 N 2.1E-001 N 8.1E+000 N 1.2E+004 N 4.7E+002 N 8.8E+001 1.8E+003 NHEXACHLORODIBENZODIOXIN MIX 19408743 6.20E+003 I 4.55E+003 I 1.1E-005 C 1.4E-006 C 5.1E-007 C 9.2E-004 C 1.0E-004 C




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgHEXACHLOROETHANE 67721 1.00E-003 I 1.40E-002 I 1.40E-002 I 4.8E+000 C ! 4.5E-001 C ! 2.3E-001 C ! 4.1E+002 C ! 4.6E+001 C ! 1.8E-002 3.6E-001 CHEXACHLOROPHENE 70304 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N 1.0E+002 2.0E+003 N1,6-HEXAMETHYLENE DIISOCYANATE 822060 2.90E-006 I 1.1E-002 N HEXANE 110543 6.00E-002 H 5.71E-002 I y 3.5E+002 N 2.1E+002 N 8.1E+001 N 1.2E+005 N 4.7E+003 N 6.9E-001 1.4E+001 N2-HEXANONE 591786 4.00E-002 E 1.4E-003 E 1.5E+003 N 5.1E+000 N 5.4E+001 N 8.2E+004 N 3.1E+003 NHEXAZINONE 51235042 3.30E-002 I 1.2E+003 N 1.2E+002 N 4.5E+001 N 6.7E+004 N 2.6E+003 NHMX 2691410 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NHYDRAZINE 302012 3.00E+000 I 1.70E+001 I 2.2E-002 C 3.7E-004 C 1.1E-003 C 1.9E+000 C 2.1E-001 CHYDROGEN CHLORIDE 7647010 5.70E-003 I 2.1E+001 N HYDROGEN SULFIDE 7783064 3.00E-003 I 2.85E-004 I 1.1E+002 N 1.0E+000 N 4.1E+000 N 6.1E+003 N 2.3E+002 NHYDROQUINONE 123319 4.00E-002 H 1.5E+003 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 NIRON 7439896 3.00E-001 E 1.1E+004 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 NISOBUTANOL 78831 3.00E-001 I y 1.8E+003 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 5.9E-001 1.2E+001 NISOPHORONE 78591 2.00E-001 I 9.50E-004 I 7.0E+001 C 6.6E+000 C 3.3E+000 C 6.0E+003 C 6.7E+002 C 2.1E-002 4.1E-001 CISOPROPALIN 33820530 1.50E-002 I 5.5E+002 N 5.5E+001 N 2.0E+001 N 3.1E+004 N 1.2E+003 NISOPROPYL METHYL PHOSPHONIC ACID 1832548 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NTETRAETHYLLEAD 78002 1.00E-007 I 3.7E-003 N 3.7E-004 N 1.4E-004 N 2.0E-001 N 7.8E-003 N 4.6E-005 9.2E-004 N**KEPONE 143500 3.00E-004 E 8.00E+000 E 8.4E-003 C 7.8E-004 C 3.9E-004 C 7.2E-001 C 8.0E-002 CLITHIUM 7439932 2.00E-002 E 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NMALATHION 121755 2.00E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 4.0E-001 8.1E+000 NMALEIC ANHYDRIDE 108316 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NMANGANESE-NONFOOD 7439965 2.00E-002 I 1.43E-005 I 7.3E+002 N 5.2E-002 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 4.8E+001 9.5E+002 NMANGANESE-FOOD 7439965 1.40E-001 I 1.43E-005 I 5.1E+003 N 5.2E-002 N 1.9E+002 N 2.9E+005 N 1.1E+004 N 3.3E+002 6.7E+003 NMEPHOSFOLAN 950107 9.00E-005 H 3.3E+000 N 3.3E-001 N 1.2E-001 N 1.8E+002 N 7.0E+000 NMEPIQUAT CHLORIDE 24307264 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 NMERCURIC CHLORIDE 7487947 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 NMERCURY (INORGANIC) 7439976 8.60E-005 I 3.1E-001 N METHYLMERCURY 22967926 1.00E-004 I 3.7E+000 N 3.7E-001 N 1.4E-001 N 2.0E+002 N 7.8E+000 NMETHACRYLONITRILE 126987 1.00E-004 I 2.00E-004 A y 1.0E+000 N 7.3E-001 N 1.4E-001 N 2.0E+002 N 7.8E+000 N 2.1E-004 4.2E-003 NMETHANOL 67561 5.00E-001 I 1.8E+004 N 1.8E+003 N 6.8E+002 N 1.0E+006 N 3.9E+004 N 3.8E+000 7.5E+001 NMETHIDATHION 950378 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 NMETHOXYCHLOR 72435 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N 1.5E+001 3.1E+002 NMETHYL ACETATE 79209 1.00E+000 H y 6.1E+003 N 3.7E+003 N 1.4E+003 N 2.0E+006 N 7.8E+004 N 1.2E+000 2.5E+001 NMETHYL ACRYLATE 96333 3.00E-002 A y 1.8E+002 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N 5.0E-001 1.0E+001 N2-METHYLANILINE 95534 2.40E-001 H 2.8E-001 C 2.6E-002 C 1.3E-002 C 2.4E+001 C 2.7E+000 C 2.8E-004 5.7E-003 C4-(2-METHYL-4-CHLOROPHENOXY) BUTYRIC ACID 94815 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N2-METHYL-4-CHLOROPHENOXYACETIC ACID (MCPA) 94746 5.00E-004 I 1.8E+001 N 1.8E+000 N 6.8E-001 N 1.0E+003 N 3.9E+001 N2-(2-METHYL-4-CHLOROPHENOXY)PROPIONIC ACID (MCP 93652 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 NMETHYLCYCLOHEXANE 108872 8.60E-001 H y 6.3E+003 N 3.1E+003 N METHYLENE BROMIDE 74953 1.00E-002 A y 6.1E+001 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N 1.5E-002 3.0E-001 NMETHYLENE CHLORIDE 75092 6.00E-002 I 7.50E-003 I 8.60E-001 H 1.65E-003 I y 4.1E+000 C 3.8E+000 C 4.2E-001 C 7.6E+002 C 8.5E+001 C 9.5E-004 1.9E-002 C4,4'-METHYLENE BIS(2-CHLOROANILINE) 101144 7.00E-004 H 1.30E-001 H 1.30E-001 H 5.2E-001 C 4.8E-002 C 2.4E-002 C 4.4E+001 C 4.9E+000 C4,4'-METHYLENE BIS(N,N'-DIMETHYL)ANILINE 101611 4.60E-002 I 1.5E+000 C 1.4E-001 C 6.9E-002 C 1.2E+002 C 1.4E+001 C4,4'-METHYLENEDIPHENYL ISOCYANATE 101688 1.7E-004 I 6.2E-001 N METHYL ETHYL KETONE (2-BUTANONE) 78933 6.00E-001 I 2.86E-001 I y 1.9E+003 N 1.0E+003 N 8.1E+002 N 1.2E+006 N 4.7E+004 N 4.0E-001 7.9E+000 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgMETHYL HYDRAZINE 60344 1.10E+000 W 6.1E-002 C 5.7E-003 C 2.9E-003 C 5.2E+000 C 5.8E-001 CMETHYL ISOBUTYL KETONE (4-METHYL-2-PENTANONE) 108101 8.00E-002 H 2.00E-002 A y 1.4E+002 N 7.3E+001 N 1.1E+002 N 1.6E+005 N 6.3E+003 N 6.5E-002 1.3E+000 NMETHYL METHACRYLATE 80626 1.40E+000 I 2.00E-001 I y 1.4E+003 N 7.3E+002 N 1.9E+003 N 2.9E+006 N 1.1E+005 N 3.2E-001 6.5E+000 N2-METHYL-5-NITROANILINE 99558 3.30E-002 H 2.0E+000 C 1.9E-001 C 9.6E-002 C 1.7E+002 C 1.9E+001 CMETHYL PARATHION 298000 2.50E-004 I 9.1E+000 N 9.1E-001 N 3.4E-001 N 5.1E+002 N 2.0E+001 N 4.3E-003 8.5E-002 N2-METHYLPHENOL 95487 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N3-METHYLPHENOL 108394 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N4-METHYLPHENOL 106445 5.00E-003 H 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NMETHYLSTYRENE MIX 25013154 6.00E-003 A 1.00E-002 A y 5.5E+001 N 3.7E+001 N 8.1E+000 N 1.2E+004 N 4.7E+002 N 5.1E-002 1.0E+000 NALPHA-METHYLSTYRENE 98839 7.00E-002 A y 4.3E+002 N 2.6E+002 N 9.5E+001 N 1.4E+005 N 5.5E+003 N 4.0E-001 7.9E+000 NMETHYL TERT-BUTYL ETHER 1634044 4.00E-003 O 8.57E-001 I y 2.6E+000 C 1.6E+000 C 7.9E-001 C 1.4E+003 C 1.6E+002 C 5.9E-004 1.2E-002 CMETOLACHLOR (DUAL) 51218452 1.50E-001 I 5.5E+003 N 5.5E+002 N 2.0E+002 N 3.1E+005 N 1.2E+004 NMIREX 2385855 2.00E-004 I 7.3E+000 N 7.3E-001 N 2.7E-001 N 4.1E+002 N 1.6E+001 NMOLYBDENUM 7439987 5E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NMONOCHLORAMINE 10599903 1E-001 I 1.00E-001 H 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NNALED 300765 2E-003 I 7.3E+001 N 7.3E+000 N 2.7E+000 N 4.1E+003 N 1.6E+002 NNICKEL REFINERY DUST 8.4E-001 I 7.5E-003 C NICKEL 7440020 2.00E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NNITRATE 14797558 1.60E+000 I 5.8E+004 N 5.8E+003 N 2.2E+003 N 3.3E+006 N 1.3E+005 NNITRIC OXIDE 10102439 1.00E-001 W y 6.1E+002 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 NNITRITE 14797650 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N2-NITROANILINE 88744 5.70E-005 H 2.1E-001 N **3-NITROANILINE 99092 3.00E-004 E 2.00E-002 E 3.00E-004 E 3.3E+000 C ! 3.1E-001 C ! 1.6E-001 C ! 2.9E+002 C ! 2.3E+001 N**4-NITROANILINE 100016 3.00E-003 E 2.00E-002 E 1.00E-003 E 3.3E+000 C 3.1E-001 C 1.6E-001 C 2.9E+002 C 3.2E+001 C !NITROBENZENE 98953 5.00E-004 I 6.00E-004 A y 3.5E+000 N 2.2E+000 N 6.8E-001 N 1.0E+003 N 3.9E+001 N 1.2E-003 2.3E-002 NNITROFURANTOIN 67209 7.00E-002 H 2.6E+003 N 2.6E+002 N 9.5E+001 N 1.4E+005 N 5.5E+003 NNITROFURAZONE 59870 1.50E+000 H 4.5E-002 C 4.2E-003 C 2.1E-003 C 3.8E+000 C 4.3E-001 CNITROGEN DIOXIDE 10102440 1.00E+000 W y 6.1E+003 N 3.7E+003 N 1.4E+003 N 2.0E+006 N 7.8E+004 NNITROGLYCERIN 55630 1.4E-002 E 4.8E+000 C 4.5E-001 C 2.3E-001 C 4.1E+002 C 4.6E+001 C4-NITROPHENOL 100027 8.00E-003 E 2.9E+002 N 2.9E+001 N 1.1E+001 N 1.6E+004 N 6.3E+002 N 8.7E-002 1.7E+000 N2-NITROPROPANE 79469 5.70E-003 I 9.40E+000 H y 1.3E-003 C 6.7E-004 C 3.2E-007 6.4E-006 CN-NITROSO-DI-N-BUTYLAMINE 924163 5.40E+000 I 5.60E+000 I y 1.9E-003 C 1.1E-003 C 5.8E-004 C 1.1E+000 C 1.2E-001 C 1.4E-006 2.7E-005 CN-NITROSODIETHANOLAMINE 1116547 2.80E+000 I 2.4E-002 C 2.2E-003 C 1.1E-003 C 2.0E+000 C 2.3E-001 CN-NITROSODIETHYLAMINE 55185 1.50E+002 I 1.50E+002 I 4.5E-004 C 4.2E-005 C 2.1E-005 C 3.8E-002 C 4.3E-003 C 1.1E-007 2.3E-006 CN-NITROSODIMETHYLAMINE 62759 5.10E+001 I 5.10E+001 I 1.3E-003 C 1.2E-004 C 6.2E-005 C 1.1E-001 C 1.3E-002 C 2.8E-007 5.7E-006 CN-NITROSODIPHENYLAMINE 86306 4.90E-003 I 1.4E+001 C 1.3E+000 C 6.4E-001 C 1.2E+003 C 1.3E+002 C 3.8E-002 7.6E-001 CN-NITROSODIPROPYLAMINE 621647 7.00E+000 I 9.6E-003 C 8.9E-004 C 4.5E-004 C 8.2E-001 C 9.1E-002 C 2.4E-006 4.7E-005 CN-NITROSO-N-ETHYLUREA 759739 1.40E+002 H 4.8E-004 C 4.5E-005 C 2.3E-005 C 4.1E-002 C 4.6E-003 CN-NITROSO-N-METHYLETHYLAMINE 10595956 2.20E+001 I 3.0E-003 C 2.8E-004 C 1.4E-004 C 2.6E-001 C 2.9E-002 CN-NITROSOPYRROLIDINE 930552 2.10E+000 I 2.10E+000 I 3.2E-002 C 3.0E-003 C 1.5E-003 C 2.7E+000 C 3.0E-001 CM-NITROTOLUENE 99081 2.00E-002 E y 1.2E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NO-NITROTOLUENE 88722 1.00E-002 H y 6.1E+001 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NP-NITROTOLUENE 99990 1.00E-002 H y 6.1E+001 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NNUSTAR 85509199 7.00E-004 I 2.6E+001 N 2.6E+000 N 9.5E-001 N 1.4E+003 N 5.5E+001 NORYZALIN 19044883 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgOXADIAZON 19666309 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NOXAMYL 23135220 2.50E-002 I 9.1E+002 N 9.1E+001 N 3.4E+001 N 5.1E+004 N 2.0E+003 N 1.9E-001 3.8E+000 NOXYFLUORFEN 42874033 3.00E-003 I 1.1E+002 N 1.1E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 NPARAQUAT DICHLORIDE 1910425 4.50E-003 I 1.6E+002 N 1.6E+001 N 6.1E+000 N 9.2E+003 N 3.5E+002 NPARATHION 56382 6.00E-003 H 2.2E+002 N 2.2E+001 N 8.1E+000 N 1.2E+004 N 4.7E+002 N 5.0E-001 1.0E+001 NPENTACHLOROBENZENE 608935 8.00E-004 I 2.9E+001 N 2.9E+000 N 1.1E+000 N 1.6E+003 N 6.3E+001 N 1.0E+000 2.0E+001 NPENTACHLORONITROBENZENE 82688 3.00E-003 I 2.60E-001 H 2.6E-001 C 2.4E-002 C 1.2E-002 C 2.2E+001 C 2.5E+000 C 4.1E-003 8.2E-002 CPENTACHLOROPHENOL 87865 3.00E-002 I 1.20E-001 I 5.6E-001 C 5.2E-002 C 2.6E-002 C 4.8E+001 C 5.3E+000 CPERMETHRIN 52645531 5.00E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N 1.2E+002 2.4E+003 N**PHENOL 108952 3.00E-001 I 1.1E+004 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 3.3E+000 6.7E+001 NM-PHENYLENEDIAMINE 108452 6.00E-003 I 2.2E+002 N 2.2E+001 N 8.1E+000 N 1.2E+004 N 4.7E+002 N 4.9E-002 9.8E-001 NO-PHENYLENEDIAMINE 95545 4.70E-002 H 1.4E+000 C 1.3E-001 C 6.7E-002 C 1.2E+002 C 1.4E+001 CP-PHENYLENEDIAMINE 106503 1.90E-001 H 6.9E+003 N 6.9E+002 N 2.6E+002 N 3.9E+005 N 1.5E+004 N2-PHENYLPHENOL 90437 1.90E-003 H 3.5E+001 C 3.3E+000 C 1.7E+000 C 3.0E+003 C 3.4E+002 CPHOSPHINE 7803512 3.00E-004 I 8.60E-005 I 1.1E+001 N 3.1E-001 N 4.1E-001 N 6.1E+002 N 2.3E+001 NPHOSPHORIC ACID 7664382 2.90E-003 I 1.1E+001 N PHOSPHORUS (WHITE) 7723140 2.00E-005 I 7.3E-001 N 7.3E-002 N 2.7E-002 N 4.1E+001 N 1.6E+000 NP-PHTHALIC ACID 100210 1.00E+000 H 3.7E+004 N 3.7E+003 N 1.4E+003 N 2.0E+006 N 7.8E+004 NPHTHALIC ANHYDRIDE 85449 2.00E+000 I 3.43E-002 H 7.3E+004 N 1.3E+002 N 2.7E+003 N 4.1E+006 N 1.6E+005 N 2.6E+001 5.2E+002 NPOLYBROMINATED BIPHENYLS 7.00E-006 H 8.90E+000 H 7.5E-003 C 7.0E-004 C 3.5E-004 C 6.4E-001 C 7.2E-002 C !POLYCHLORINATED BIPHENYLS 1336363 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 C 2.1E-002 4.1E-001 CAROCLOR-1016 12674112 7.00E-005 I 7.00E-002 I 7.00E-002 I 9.6E-001 C ! 8.9E-002 C ! 4.5E-002 C ! 8.2E+001 C ! 5.5E+000 N 2.1E-001 4.2E+000 CAROCLOR-1221 11104282 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 CAROCLOR-1232 11141165 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 CAROCLOR-1242 53469219 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 CAROCLOR-1248 12672296 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 CAROCLOR-1254 11097691 2.00E-005 I 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 C ! 5.4E-002 1.1E+000 CAROCLOR-1260 11096825 2.00E+000 I 2.00E+000 I 3.3E-002 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 CPOLYCHLORINATED TERPHENYLS 61788338 4.50E+000 E 1.5E-002 C 1.4E-003 C 7.0E-004 C 1.3E+000 C 1.4E-001 CPOLYNUCLEAR AROMATIC HYDROCARBONS:ACENAPHTHENE 83329 6.00E-002 I y 3.7E+002 N 2.2E+002 N 8.1E+001 N 1.2E+005 N 4.7E+003 N 5.2E+000 1.0E+002 NANTHRACENE 120127 3.00E-001 I y 1.8E+003 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 2.3E+001 4.7E+002 NBENZ[A]ANTHRACENE 56553 7.30E-001 E 9.2E-002 C 8.6E-003 C 4.3E-003 C 7.8E+000 C 8.7E-001 C 7.3E-002 1.5E+000 CBENZO[B]FLUORANTHENE 205992 7.30E-001 E 9.2E-002 C 8.6E-003 C 4.3E-003 C 7.8E+000 C 8.7E-001 C 2.3E-001 4.5E+000 CBENZO[K]FLUORANTHENE 207089 7.30E-002 E 9.2E-001 C 8.6E-002 C 4.3E-002 C 7.8E+001 C 8.7E+000 C 2.3E+000 4.5E+001 CBENZO[A]PYRENE 50328 7.30E+000 I 3.10E+000 E 9.2E-003 C 2.0E-003 C 4.3E-004 C 7.8E-001 C 8.7E-002 C 1.9E-002 3.7E-001 CCARBAZOLE 86748 2.00E-002 H 3.3E+000 C 3.1E-001 C 1.6E-001 C 2.9E+002 C 3.2E+001 C 2.3E-002 4.7E-001 CCHRYSENE 218019 7.30E-003 E 9.2E+000 C 8.6E-001 C 4.3E-001 C 7.8E+002 C 8.7E+001 C 7.3E+000 1.5E+002 CDIBENZ[A,H]ANTHRACENE 53703 7.30E+000 E 9.2E-003 C 8.6E-004 C 4.3E-004 C 7.8E-001 C 8.7E-002 C 7.0E-002 1.4E+000 CDIBENZOFURAN 132649 4.00E-003 E y 2.4E+001 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 N 3.8E-001 7.7E+000 NFLUORANTHENE 206440 4.00E-002 I 1.5E+003 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 N 3.1E+002 6.3E+003 NFLUORENE 86737 4.00E-002 I y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 N 6.8E+000 1.4E+002 NINDENO[1,2,3-C,D]PYRENE 193395 7.30E-001 E 9.2E-002 C 8.6E-003 C 4.3E-003 C 7.8E+000 C 8.7E-001 C 6.4E-001 1.3E+001 C2-METHYLNAPHTHALENE 91576 2.00E-002 E y 1.2E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 1.1E+000 2.2E+001 NNAPHTHALENE 91203 2.00E-002 I 9.00E-004 I y 6.5E+000 N 3.3E+000 N 2.7E+001 N 4.1E+004 N 1.6E+003 N 7.7E-003 1.5E-001 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgPYRENE 129000 3.00E-002 I y 1.8E+002 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N 3.4E+001 6.8E+002 NPROMETON 1610180 1.50E-002 I 5.5E+002 N 5.5E+001 N 2.0E+001 N 3.1E+004 N 1.2E+003 NPROMETRYN 7287196 4.00E-003 I 1.5E+002 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 NPROPACHLOR 1918167 1.30E-002 I 4.7E+002 N 4.7E+001 N 1.8E+001 N 2.7E+004 N 1.0E+003 NPROPANIL 709988 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NPROPARGITE 2312358 2.00E-002 I 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NN-PROPYLBENZENE 103651 4.00E-002 E y 2.4E+002 N 1.5E+002 N 5.4E+001 N 8.2E+004 N 3.1E+003 N 1.4E+000 2.8E+001 NPROPYLENE GLYCOL 57556 2.00E+001 H 7.3E+005 N 7.3E+004 N 2.7E+004 N 4.1E+007 N 1.6E+006 NPROPYLENE GLYCOL, MONOETHYL ETHER 52125538 7.00E-001 H 2.6E+004 N 2.6E+003 N 9.5E+002 N 1.4E+006 N 5.5E+004 NPROPYLENE GLYCOL, MONOMETHYL ETHER 107982 7.00E-001 H 5.70E-001 I 2.6E+004 N 2.1E+003 N 9.5E+002 N 1.4E+006 N 5.5E+004 NPURSUIT 81335775 2.50E-001 I 9.1E+003 N 9.1E+002 N 3.4E+002 N 5.1E+005 N 2.0E+004 NPYRIDINE 110861 1.00E-003 I 3.7E+001 N 3.7E+000 N 1.4E+000 N 2.0E+003 N 7.8E+001 NQUINOLINE 91225 3.00E+000 I 2.2E-002 C 2.1E-003 C 1.1E-003 C 1.9E+000 C 2.1E-001 CRDX 121824 3.00E-003 I 1.10E-001 I 6.1E-001 C 5.7E-002 C 2.9E-002 C 5.2E+001 C 5.8E+000 CRESMETHRIN 10453868 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 NRONNEL 299843 5.00E-002 H 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 NROTENONE 83794 4.00E-003 I 1.5E+002 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 NSELENIOUS ACID 7783008 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NSELENIUM 7782492 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N 9.5E-001 1.9E+001 NSILVER 7440224 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N 1.6E+000 3.1E+001 NSIMAZINE 122349 5.00E-003 I 1.20E-001 H 5.6E-001 C 5.2E-002 C 2.6E-002 C 4.8E+001 C 5.3E+000 C 1.7E-004 3.3E-003 CSODIUM AZIDE 26628228 4.00E-003 I 1.5E+002 N 1.5E+001 N 5.4E+000 N 8.2E+003 N 3.1E+002 NSODIUM DIETHYLDITHIOCARBAMATE 148185 3.00E-002 I 2.70E-001 H 2.5E-001 C 2.3E-002 C 1.2E-002 C 2.1E+001 C 2.4E+000 CSTRONTIUM, STABLE 7440246 6.00E-001 I 2.2E+004 N 2.2E+003 N 8.1E+002 N 1.2E+006 N 4.7E+004 N 7.7E+002 1.5E+004 NSTRYCHNINE 57249 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N 8.3E-003 1.7E-001 NSTYRENE 100425 2.00E-001 I 2.86E-001 I y 1.6E+003 N 1.0E+003 N 2.7E+002 N 4.1E+005 N 1.6E+004 N 2.9E+000 5.7E+001 N2,3,7,8-TETRACHLORODIBENZODIOXIN 1746016 1.50E+005 H 1.50E+005 H 4.5E-007 C 4.2E-008 C 2.1E-008 C 3.8E-005 C 4.3E-006 C 4.3E-007 8.6E-006 C1,2,4,5-TETRACHLOROBENZENE 95943 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N 3.3E-002 6.6E-001 N1,1,1,2-TETRACHLOROETHANE 630206 3.00E-002 I 2.60E-002 I 2.60E-002 I y 4.1E-001 C 2.4E-001 C 1.2E-001 C 2.2E+002 C 2.5E+001 C 2.0E-004 4.0E-003 C1,1,2,2-TETRACHLOROETHANE 79345 6.00E-002 E 2.00E-001 I 2.00E-001 I y 5.3E-002 C 3.1E-002 C 1.6E-002 C 2.9E+001 C 3.2E+000 C 3.4E-005 6.8E-004 CTETRACHLOROETHENE 127184 1.00E-002 I 5.2E-002 E 1.4E-001 E 1.00E-002 E y 6.3E-001 C 6.3E-001 C 6.1E-002 C 1.1E+002 C 1.2E+001 C 1.4E-003 2.9E-002 C2,3,4,6-TETRACHLOROPHENOL 58902 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 NP,A,A,A-TETRACHLOROTOLUENE 5216251 2.00E+001 H 3.3E-003 C 3.1E-004 C 1.6E-004 C 2.9E-001 C 3.2E-002 C1,1,1,2-TETRAFLUOROETHANE 811972 2.29E+001 I y 1.7E+005 N 8.4E+004 N TETRAHYDROFURAN 109999 2.00E-001 E 7.6E-003 E 8.6E-002 E 6.8E-003 E 8.8E+000 C 9.2E-001 C 4.2E-001 C 7.5E+002 C 8.4E+001 CTETRYL 479458 1.00E-002 H 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NTHALLIC OXIDE 1314325 7.00E-005 W 2.6E+000 N 2.6E-001 N 9.5E-002 N 1.4E+002 N 5.5E+000 NTHALLIUM 7440280 7.00E-005 O 2.6E+000 N 2.6E-001 N 9.5E-002 N 1.4E+002 N 5.5E+000 N 1.8E-001 3.6E+000 NTHALLIUM ACETATE 563688 9.00E-005 I 3.3E+000 N 3.3E-001 N 1.2E-001 N 1.8E+002 N 7.0E+000 NTHALLIUM CARBONATE 6533739 8.00E-005 I 2.9E+000 N 2.9E-001 N 1.1E-001 N 1.6E+002 N 6.3E+000 NTHALLIUM CHLORIDE 7791120 8.00E-005 I 2.9E+000 N 2.9E-001 N 1.1E-001 N 1.6E+002 N 6.3E+000 NTHALLIUM NITRATE 10102451 9.00E-005 I 3.3E+000 N 3.3E-001 N 1.2E-001 N 1.8E+002 N 7.0E+000 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgTHALLIUM SULFATE (2:1) 7446186 8.00E-005 I 2.9E+000 N 2.9E-001 N 1.1E-001 N 1.6E+002 N 6.3E+000 NTHIOBENCARB 28249776 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 NTIN 7440315 6.00E-001 H 2.2E+004 N 2.2E+003 N 8.1E+002 N 1.2E+006 N 4.7E+004 NTITANIUM 7440326 4.00E+000 E 8.60E-003 E 1.5E+005 N 3.1E+001 N 5.4E+003 N 8.2E+006 N 3.1E+005 NTITANIUM DIOXIDE 13463677 4.00E+000 E 8.60E-003 E 1.5E+005 N 3.1E+001 N 5.4E+003 N 8.2E+006 N 3.1E+005 NTOLUENE 108883 2.00E-001 I 1.14E-001 I y 7.5E+002 N 4.2E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 N 4.4E-001 8.8E+000 NTOLUENE-2,4-DIAMINE 95807 3.20E+000 H 2.1E-002 C 2.0E-003 C 9.9E-004 C 1.8E+000 C 2.0E-001 CTOLUENE-2,5-DIAMINE 95705 6.00E-001 H 2.2E+004 N 2.2E+003 N 8.1E+002 N 1.2E+006 N 4.7E+004 NTOLUENE-2,6-DIAMINE 823405 2.00E-001 H 7.3E+003 N 7.3E+002 N 2.7E+002 N 4.1E+005 N 1.6E+004 NP-TOLUIDINE 106490 1.90E-001 H 3.5E-001 C 3.3E-002 C 1.7E-002 C 3.0E+001 C 3.4E+000 C 3.0E-004 5.9E-003 CTOXAPHENE 8001352 1.10E+000 I 1.10E+000 I 6.1E-002 C 5.7E-003 C 2.9E-003 C 5.2E+000 C 5.8E-001 C 3.1E-002 6.3E-001 C1,2,4-TRIBROMOBENZENE 615543 5.00E-003 I 1.8E+002 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 NTRIBUTYLTIN OXIDE 56359 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N2,4,6-TRICHLOROANILINE 634935 3.40E-002 H 2.0E+000 C 1.8E-001 C 9.3E-002 C 1.7E+002 C 1.9E+001 C**1,2,4-TRICHLOROBENZENE 120821 1.00E-002 I 1.00E-003 E y 7.2E+000 N 3.7E+000 N 1.4E+001 N 2.0E+004 N 7.8E+002 N 1.4E-002 2.8E-001 N1,1,1-TRICHLOROETHANE 71556 2.80E-001 E 6.30E-001 E y 3.2E+003 N 2.3E+003 N 3.8E+002 N 5.7E+005 N 2.2E+004 N 3.0E+000 6.0E+001 N1,1,2-TRICHLOROETHANE 79005 4.00E-003 I 5.70E-002 I 5.60E-002 I y 1.9E-001 C 1.1E-001 C 5.5E-002 C 1.0E+002 C 1.1E+001 C 3.9E-005 7.8E-004 CTRICHLOROETHENE 79016 3.00E-004 E 4.00E-001 E 1.00E-002 E 4.00E-001 E y 2.6E-002 C 1.6E-002 C 7.9E-003 C 1.4E+001 C 1.6E+000 C 1.3E-005 2.6E-004 CTRICHLOROFLUOROMETHANE 75694 3.00E-001 I 2.00E-001 A y 1.3E+003 N 7.3E+002 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 1.1E+000 2.3E+001 N2,4,5-TRICHLOROPHENOL 95954 1.00E-001 I 3.7E+003 N 3.7E+002 N 1.4E+002 N 2.0E+005 N 7.8E+003 N2,4,6-TRICHLOROPHENOL 88062 1.10E-002 I 1.00E-002 I 6.1E+000 C 6.3E-001 C 2.9E-001 C 5.2E+002 C 5.8E+001 C2,4,5-T 93765 1.00E-002 I 3.7E+002 N 3.7E+001 N 1.4E+001 N 2.0E+004 N 7.8E+002 N 9.8E-002 2.0E+000 N2-(2,4,5-TRICHLOROPHENOXY)PROPIONIC ACID 93721 8.00E-003 I 2.9E+002 N 2.9E+001 N 1.1E+001 N 1.6E+004 N 6.3E+002 N 1.1E+000 2.1E+001 N1,1,2-TRICHLOROPROPANE 598776 5.00E-003 I y 3.0E+001 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N 1.2E-002 2.5E-001 N1,2,3-TRICHLOROPROPANE 96184 6.00E-003 I 2.00E+000 E 1.4E-003 E y 5.3E-003 C 3.1E-003 C 1.6E-003 C 2.9E+000 C 3.2E-001 C 1.8E-006 3.6E-005 C1,2,3-TRICHLOROPROPENE 96195 5.00E-003 H y 3.0E+001 N 1.8E+001 N 6.8E+000 N 1.0E+004 N 3.9E+002 N 1.2E-002 2.5E-001 N1,1,2-TRICHLORO-1,2,2-TRIFLUOROETHANE 76131 3.00E+001 I 8.60E+000 H y 5.9E+004 N 3.1E+004 N 4.1E+004 N 6.1E+007 N 2.3E+006 N 1.2E+002 2.3E+003 N1,2,4-TRIMETHYLBENZENE 95636 5.00E-002 E 1.70E-003 E y 1.2E+001 N 6.2E+000 N 6.8E+001 N 1.0E+005 N 3.9E+003 N1,3,5-TRIMETHYLBENZENE 108678 5.00E-002 E 1.70E-003 E y 1.2E+001 N 6.2E+000 N 6.8E+001 N 1.0E+005 N 3.9E+003 NTRIMETHYL PHOSPHATE 512561 3.70E-002 H 1.8E+000 C 1.7E-001 C 8.5E-002 C 1.5E+002 C 1.7E+001 C1,3,5-TRINITROBENZENE 99354 3.00E-002 I 1.1E+003 N 1.1E+002 N 4.1E+001 N 6.1E+004 N 2.3E+003 N2,4,6-TRINITROTOLUENE 118967 5.00E-004 I 3.00E-002 I 2.2E+000 C ! 2.1E-001 C ! 1.1E-001 C ! 1.9E+002 C ! 2.1E+001 C !URANIUM (SOLUBLE SALTS; from IRIS) 7440611 3.00E-003 I 1.1E+002 N 1.1E+001 N 4.1E+000 N 6.1E+003 N 2.3E+002 NURANIUM (SOLUBLE SALTS; provisional) 7440611 2.00E-004 E 7.3E+000 N 7.3E-001 N 2.7E-001 N 4.1E+002 N 1.6E+001 NVANADIUM 7440622 7.00E-003 H 2.6E+002 N 2.6E+001 N 9.5E+000 N 1.4E+004 N 5.5E+002 N 2.6E+002 5.1E+003 NVANADIUM PENTOXIDE 1314621 9.00E-003 I 3.3E+002 N 3.3E+001 N 1.2E+001 N 1.8E+004 N 7.0E+002 NVANADIUM SULFATE 16785812 2.00E-002 H 7.3E+002 N 7.3E+001 N 2.7E+001 N 4.1E+004 N 1.6E+003 NVINCLOZOLIN 50471448 2.50E-002 I 9.1E+002 N 9.1E+001 N 3.4E+001 N 5.1E+004 N 2.0E+003 NVINYL ACETATE 108054 1.00E+000 H 5.71E-002 I y 4.1E+002 N 2.1E+002 N 1.4E+003 N 2.0E+006 N 7.8E+004 N 8.7E-002 1.7E+000 NVINYL CHLORIDE inc earlylife(see cover memos) 75014 3.00E-003 I 1.40E+000 I 2.8E-002 I 3.00E-002 I y 1.5E-002 C 7.2E-002 C 9.0E-002 C 1.7E-005 3.3E-004 CVINYL CHLORIDE: adult (see cover memos) 75014 3.00E-003 I 7.20E-001 I 2.8E-002 I 1.5E-002 I y 4.4E-003 C 7.9E+000 CWARFARIN 81812 3.00E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 N 2.2E-002 4.4E-001 N




RfDo CSFo RfDi CSFi water air Fish Industrial Residential DAF 1 DAF 20Chemical CAS mg/kg/d 1/mg/kg/d mg/kg/d 1/mg/kg/d VOC ug/l ug/m3 mg/kg mg/kg mg/kg mg/kg mg/kgM-XYLENE 108383 2.00E+000 H y 1.2E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 N 1.3E+001 2.5E+002 NO-XYLENE 95476 2.00E+000 H y 1.2E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 N 1.1E+001 2.3E+002 NP-XYLENE 106423 y XYLENES 1330207 2.00E+000 I y 1.2E+004 N 7.3E+003 N 2.7E+003 N 4.1E+006 N 1.6E+005 N 8.5E+000 1.7E+002 NZINC 7440666 3.00E-001 I 1.1E+004 N 1.1E+003 N 4.1E+002 N 6.1E+005 N 2.3E+004 N 6.8E+002 1.4E+004 NZINC PHOSPHIDE 1314847 3E-004 I 1.1E+001 N 1.1E+000 N 4.1E-001 N 6.1E+002 N 2.3E+001 NZINEB 12122677 5E-002 I 1.8E+003 N 1.8E+002 N 6.8E+001 N 1.0E+005 N 3.9E+003 N

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Rule R309-200. Monitoring and Water Quality: Drinking Water Standards.

As in effect on February 1, 2003

Table of Contents • R309-200-1. Purpose.

• R309-200-2. Authority.

• R309-200-3. Definitions.

• R309-200-4. General.

• R309-200-5. Primary Drinking Water Standards.

• R309-200-6. Secondary Drinking Water Standards for Community, Non-Transient Non-Community and Transient Non-Community Water.

• R309-200-7. Treatment Techniques and Unregulated Contaminants.

• R309-200-8. Approved Laboratories.

• KEY

• Date of Enactment or Last Substantive Amendment

• Notice of Continuation

• Authorizing, Implemented, or Interpreted Law

R309-200-1. Purpose. The purpose of this rule is to set forth the water quality and drinking water standards for public water systems. R309-200-2 Authority. R309-200-3 Definitions. R309-200-4 General. R309-200-5 Primary Drinking Water Standards (1) Inorganic Contaminants (2) Lead and Copper (3) Organic Monitoring. (4) Radiological Chemicals. (5) Turbidity. (6) Microbiological quality

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(7) Disinfection R309-200-6 Secondary Drinking Water Standards. R309-200-7 Treatment Techniques and Unregulated Contamiants. R309-200-8 Approved Laboratories.

R309-200-2. Authority. This rule is promulgated by the Drinking Water Board as authorized by Title 19, Environmental Quality Code, Chapter 4, Safe Drinking Water Act, Subsection 104 of the Utah Code and in accordance with 63-46a fo the same, known as the Administrative Rulemaking Act.

R309-200-3. Definitions. Definitions for certain terms used in this rule are given in R309-110 but may be further clarified herein.

R309-200-4. General. (1) Maximum contaminant levels (MCLs) and treatment techniques are herein established for those routinely measurable substances which may be found in water supplies. "Primary" standards and treatment techniques are established for the protection of human health. "Secondary" regulations are established to provide guidance in evaluating the aesthetic qualities of drinking water. (2) The applicable "Primary" standards and treatment techniques shall be met by all public drinking water systems. The "Secondary" standards are recommended levels which should be met in order to avoid consumer complaint. (3) The methods used to determine compliance with these maximum contaminant levels and treatment techniques are given in R309-205 through R309-215. Analytical techniques which shall be followed in making the required determinations shall be as given in 40 CFR 141 as published on July 1, 2001 by the Office of the Federal Register. (4) Unless otherwise required by the Board, the effective dates on which new analytical methods shall be initiated are identical to the dates published in 40 CFR 141 on July 1, 2001 by the Office of the Federal Register. (5) If the water fails to meet these minimum standards, then certain public notification procedures shall be carried out, as outlined in R309-220. Water suppliers shall also keep analytical records in their possession, for a required length of time, as outlined in R309-105-17.

R309-200-5. Primary Drinking Water Standards. (1) Inorganic Contaminants. (a) The maximum contaminant levels (MCLs) for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sodium, thallium and total dissolved solids are applicable to community and non-transient non-community water systems. (b) The MCLs for nitrate, nitrite, and total nitrate, nitrite and sulfate are applicable to community, non-transient non-community, and transient non-community water systems. (c) The maximum contaminant levels for inorganic chemicals are listed in Table 200-1. TABLE 200-1 PRIMARY INORGANIC CONTAMINANTS Contaminant Maximum Contaminant Level 1. Antimony 0.006 mg/L

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2. Arsenic 0.05 mg/L 3. Asbestos 7 Million Fibers/liter (longer than 10 um) 4. Barium 2 mg/L 5. Beryllium 0.004 mg/L 6. Cadmium 0.005 mg/L 7. Chromium 0.1 mg/L 8. Cyanide (as free Cyanide) 0.2 mg/L 9. Fluoride 4.0 mg/L 10. Mercury 0.002 mg/L 11. Nickel --- (see Note 1 below) 12. Nitrate 10 mg/l (as Nitrogen) (see Note 4 below) 13. Nitrite 1 mg/L (as Nitrogen) 14. Total Nitrate and Nitrite 10 mg/L (as Nitrogen) 15. Selenium 0.05 mg/L 16. Sodium --- (see Note 1 below) 17. Sulfate 1000 mg/L (see Note 2 below) 18. Thallium 0.002 mg/L 19. Total Dissolved Solids 2000 mg/L (see Note 3 below) NOTE: (1) No maximum contaminant level has been established for nickel and sodium. However, these contaminant shall be monitored and reported in accordance with the requirements of R309-205-5(3). (2) If the sulfate level of a public (community, NTNC and non-community) water system is greater than 500 mg/L, the supplier shall satisfactorily demonstrate that: (a) No better quality water is available, and (b) The water shall not be available for human consumption from commercial establishments. In no case shall the Board allow the use of water having a sulfate level greater than 1000 mg/L. (3) If TDS is greater than 1000 mg/L, the supplier shall satisfactorily demonstrate to the Board that no better water is available. The Board shall not allow the use of an inferior source of water if a better source of water (i.e. lower in TDS) is available. (4) In the case of a non-community water systems which exceed the MCL for nitrate, the Executive Secretary may allow, on a case-by-case basis, a nitrate level not to exceed 20 mg/L if the supplier can adequately demonstrate that: (a) such water will not be available to children under 6 months of age as may be the case in hospitals, schools and day care centers; and (b) there will be continuous posting of the fact that nitrate levels exceed 10 mg/L and the potential health effect of exposure in accordance with R309-220-12; and (c) the water is analyzed in conformance to R309-205-5(4); and (d) that no adverse health effects will result. (2) Lead and copper. (a) The lead action level is exceeded if the concentration of lead in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with R309-210-6(3) is greater than 0.015 mg/L (i.e., if the "90th percentile" lead level is greater than 0.015 mg/L).

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(b) The copper action level is exceeded if the concentration of copper in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with R309-210-6(3) is greater than 1.3 mg/L (i.e., if the "90th percentile" copper level is greater than 1.3 mg/L). (c) The 90th percentile lead and copper levels shall be computed as follows: (i) The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number, ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken. (ii) The number of samples taken during the monitoring period shall be multiplied by 0.9. (iii) The contaminant concentration in the numbered sample yielded by the calculation in paragraph (c)(ii) above is the 90th percentile contaminant level. (iv) For water systems serving fewer than 100 people that collect 5 samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations. (3) Organic Contaminants. The following are the maximum contaminant levels for organic chemicals. For the purposes of R309-100 through R309-R309-605, organic chemicals are divided into three categories: Pesticides/PCBs/SOCs, volatile organic contaminants (VOCs) and total trihalomethanes. (a) Pesticides/PCBs/SOCs - The MCLs for organic contaminants listed in Table 200-2 are applicable to community water systems and non-transient, non-community water systems. TABLE 200-2 PESTICIDE/PCB/SOC CONTAMINANTS Contaminant Maximum Contaminant Level 1. Alachlor 0.002 mg/L 2. Aldicarb (see Note 1 below) 3. Aldicarb sulfoxide (see Note 1 below) 4. Aldicarb sulfone (see Note 1 below) 5. Atrazine 0.003 mg/L 6. Carbofuran 0.04 mg/L 7. Chlordane 0.002 mg/L 8. Dibromochloropropane 0.0002 mg/L 9. 2,4-D 0.07 mg/L 10. Ethylene dibromide 0.00005 mg/L 11. Heptachlor 0.0004 mg/L 12. Heptachlor epoxide 0.0002 mg/L 13. Lindane 0.0002 mg/L 14. Methoxychlor 0.04 mg/L 15. Polychlorinated biphenyls 0.0005 mg/L 16. Pentachlorophenol 0.001 mg/L 17. Toxaphene 0.003 mg/L 18. 2,4,5-TP 0.05 mg/L 19. Benzo(a)pyrene 0.0002 mg/L 20. Dalapon 0.2 mg/L 21. Di(2-ethylhexyl)adipate 0.4 mg/L 22. Di(2-ethylhexyl)phthalate 0.006 mg/L 23. Dinoseb 0.007 mg/L 24. Diquat 0.02 mg/L

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25. Endothall 0.1 mg/L 26. Endrin 0.002 mg/L 27. Glyphosate 0.7 mg/L 28. Hexachlorobenzene 0.001 mg/L 29. Hexachlorocyclopentadiene 0.05 mg/L 30. Oxamyl (Vydate) 0.2 mg/L 31. Picloram 0.5 mg/L 32. Simazine 0.004 mg/L 33. 2,3,7,8-TCDD (Dioxin) 0.00000003 mg/L Note 1: The MCL for this contaminant is under further review, however, this contaminant shall be monitored in accordance with R309-205-6(1). (b) Volatile organic contaminants - The maximum contaminant levels for organic contaminants listed in Table 200-3 apply to community and non-transient non-community water systems. TABLE 200-3 VOLATILE ORGANIC CONTAMINANTS Contaminant Maximum Contaminant Level 1. Vinyl chloride 0.002 mg/L 2. Benzene 0.005 mg/L 3. Carbon tetrachloride 0.005 mg/L 4. 1,2-Dichloroethane 0.005 mg/L 5. Trichloroethylene 0.005 mg/L 6. para-Dichlorobenzene 0.075 mg/L 7. 1,1-Dichloroethylene 0.007 mg/L 8. 1,1,1-Trichloroethane 0.2 mg/L 9. cis-1,2-Dichloroethylene 0.07 mg/L 10. 1,2-Dichloropropane 0.005 mg/L 11. Ethylbenzene 0.7 mg/L 12. Monochlorobenzene 0.1 mg/L 13. o-Dichlorobenzene 0.6 mg/L 14. Styrene 0.1 mg/L 15. Tetrachloroethylene 0.005 mg/L 16. Toluene 1 mg/L 17. trans-1,2-Dichloroethylene 0.1 mg/L 18. Xylenes (total) 10 mg/L 19. Dichloromethane 0.005 mg/L 20. 1,2,4-Trichlorobenzene 0.07 mg/L 21. 1,1,2-Trichloroethane 0.005 mg/L (c) Disinfection Byproducts and Disinfectant Residuals: (i) Community and Non-transient non-community water systems. Surface Water systems serving 10,000 or more persons shall comply with this section beginning January 1, 2002. Surface water systems serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water shall comply with this section beginning January 1, 2004. Community water systems utilizing only groundwater sources serving 10,000 persons or more shall monitor in accordance with R309-210-9 and meet the MCL listed in paragraph (vii) of this section until December 31, 2003. (ii) Transient non-community water systems. Surface water systems serving 10,000 or more persons and using chlorine dioxide as a disinfectant or oxidant shall comply with the chlorine dioxide MRDL beginning January 1, 2002. Surface water

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systems serving fewer than 10,000 persons and using chlorine dioxide as a disinfectant or oxidant and systems using only ground water not under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant shall comply with the chlorine dioxide MRDL beginning January 1, 2004. (iii) The maximum contaminant levels (MCLs) for disinfection byproducts are listed in Table 200- 4. TABLE 200-4 DISINFECTION BYPRODUCTS DISINFECTION BYPRODUCT MCL (mg/L) Total trihalomethanes (TTHM) 0.080 Haloacetic acids (five) (HAA5) 0.060 Bromate 0.010 Chlorite 1.0 (iv) The maximum residual disinfectant levels (MRDLs) are listed in Table 200-5. TABLE 200-5 MAXIMUM RESIDUAL DISINFECTANT LEVELS DISINFECTANT RESIDUAL MRDL (mg/L) Chlorine 4.0 (as Cl2) Chloramines 4.0 (as Cl2) Chlorine dioxide 0.8 (as ClO2) (v) Control of Disinfectant Residuals. Notwithstanding the MRDLs listed in Table 200-5, systems may increase residual disinfectant levels in the distribution system of chlorine or chloramines (but not chlorine dioxide) to a level and for a time necessary to protect public health, to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross-connection events. (vi) A system that is installing GAC or membrane technology to comply with this section may apply to the Executive Secretary for an extension of up to 24 months past the dates in paragraph (c)(i) of this section, but not beyond December 31, 2003. In granting the extension, the Executive Secretary shall set a schedule for compliance and may specify any interim measures that the system shall take. Failure to meet the schedule or interim treatment requirements constitutes a violation of Utah Public Drinking Water Rules. (vii) Community water systems utilizing only groundwater sources serving 10,000 persons or more shall monitor in accordance with R309-210-9 and meet the following MCL until December 31, 2003. (A) The running average of analyses of quenched TTHM samples for four consecutive calendar quarters shall not exceed 100 micrograms per liter. (B) The single sample Total Trihalomethane Formation Potential (THMFP) shall not exceed 100 micrograms per liter. Approval is needed from the Executive Secretary to substitute this test for TTHM samples and may only be used for groundwater sources. Compliance for each source is based on measurement of this sample. (4) Radiologic Chemicals. (a) Compliance dates. Compliance dates for combined radium-226 and -228, gross alpha particle activity, gross beta particle and photon radioactivity, and uranium: Community water systems shall comply with the MCLs listed in paragraphs (b), (c), (d), and (e) of this section beginning December 8, 2003 and compliance shall be determined in accordance with the requirements of this sub-section (4) and R309-

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205-7. Compliance with reporting requirements for the radionuclides under R309-220 and R309-225 is required on December 8, 2003. (b) Combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium- 228 is 5 pCi/L. The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228. (c) Gross alpha particle activity (excluding radon and uranium). The maximum contaminant level for gross alpha particle activity (including radium-226 but excluding radon and uranium) is 15 pCi/L. (d) The MCL for beta particle and photon radioactivity. (i) The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year (mrem/year). (ii) Except for the radionuclides listed in Table 200-6, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of 2 liters per day drinking water intake using the 168 hour data list in "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure," NBS (National Bureau of Standards) Handbook 69 as amended August 1963, U.S. Department of Commerce. Copies of this document are available from the National Technical Information Service, NTIS ADA 280 282, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll-free number is 800-553-6847. Copies may be inspected at the Division of Drinking Water offices. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year. TABLE 200-6 MAN-MADE RADIONUCLIDE CONTAMINANTS Average Annual Concentrations Assumed to Produce: A Total Body or Organ Dose of 4 mrem/yr Radionuclide Critical organ pCi per liter Tritium Total body 20,000 Strontium-90 Bone Marrow 8 (e) The MCL for uranium. The maximum contaminant level for uranium is 30 þg/L. (5) TURBIDITY (a) Large surface water systems serving 10,000 or more population shall provide treatment consisting of both disinfection, as specified in R309-200-5(7)(a), and filtration treatment which complies with the requirements of paragraph (i), (ii) or (iii) of this section by January 1, 2002. (i) Conventional filtration treatment or direct filtration. (A) For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water shall be less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month, measured as specified in R309-200-4(3) and R309-215-9. (B) The turbidity level of representative samples of a system's filtered water shall at no time exceed 1 NTU, measured as specified in R309-200-4(3) and R309-215-9. (C) A system that uses lime softening may acidify representative samples prior to analysis using a protocol approved by the Executive Secretary. (ii) Filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water

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system may use a filtration technology not listed in paragraph (i) or (iii) of this section if it demonstrates to the Executive Secretary, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of R309-200-7, consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts and 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts, and the Executive Secretary approves the use of the filtration technology. For each approval, the Executive Secretary will set turbidity performance requirements that the system shall meet at least 95 percent of the time and that the system may not exceed at any time at a level that consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts, 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts. (iii) The turbidity limit for slow sand filtration and diatomaceous earth filtration shall be less than or equal to 1.0 NTU in at least 95 percent of the measurements taken each month, measured as specified in R309-215- 9(1)(c) and (d). For slow sand filtration only, if the Executive Secretary determines that the system is capable of achieving 99.9 percent removal and inactivation of Giardia lamblia cysts at some turbidity level higher than 1.0 NTU in at least 95 percent of the measurements, the Executive Secretary may substitute this higher turbidity limit for that system. (b) Small surface water systems serving a population less than 10,000: (i) The following turbidity limit applies to finished water from small surface water treatment facilities providing water to all public water systems whether community, non-transient non-community or non-community. (ii) The limit for turbidity in drinking water from treatment facilities which utilize surface water sources or ground water sources under the direct influence of surface water is 0.5 NTU in at least 95 percent of the samples as required by R309-215-9(1)(c) for conventional complete treatment and direct filtration. If the Executive Secretary determines that the system is capable of achieving at least 99.9 percent removal and inactivation of Giardia lamblia cysts at some turbidity level higher than 0.5 NTU in at least 95 percent of the measurements, the Executive Secretary may substitute this higher turbidity limit for that system. However, in no case may the Executive Secretary approve a turbidity limit that allows more than 1.0 NTU in more than 5 percent of the samples taken each month, measured as specified in R309- 215-9(1)(c) and (d). (A) The turbidity limit for slow sand filtration and diatomaceous earth filtration shall be less than or equal to 1.0 NTU in at least 95 percent of the measurements taken each month, measured as specified in R309-215-9(1)(c) and (d). For slow sand filtration only, if the Executive Secretary determines that the system is capable of achieving 99.9 percent removal and inactivation of Giardia lamblia cysts at some turbidity level higher than 1.0 NTU in at least 95 percent of the measurements, the Executive Secretary may substitute this higher turbidity limit for that system. (B) The turbidity level of representative samples shall at no time exceed 5.0 NTU for any treatment technique, measured as specified in R309-215-9(1)(c) and (d). (C) The Executive Secretary may allow the higher turbidity limits for the above treatment techniques only if the supplier of water can demonstrate to the Executive Secretary's satisfaction that the higher turbidity does not do any of the following: (I) Interfere with disinfection; (II) Prevent maintenance of an effective disinfectant agent throughout the distribution system; (III) Interfere with microbiological determinations; or

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(IV) Interfere with a treatment technique's ability to achieve the required log removal/inactivation of pathogens or virus as required by R309-505-6(2)(a) and (b). (c) Ground water sources not under the direct influence of surface water: (i) The following turbidity limit applies to community water systems only. (ii) The limit for turbidity in drinking water from ground water sources not under the direct influence of surface sources is 5.0 NTU based on an average for two consecutive days pursuant to R309-205-8(3). (6) MICROBIOLOGICAL QUALITY (a) The maximum contaminant level (MCL) for microbiological contaminants for all public water systems is: (i) For a system which collects less than 40 total coliform samples per month, no more than one sample per month may be total coliform-positive. (ii) For a system which collects 40 or more total coliform samples per month, no more than 5.0 percent of the samples collected during a month may be total coliform-positive. (b) Any fecal coliform-positive or Escherichia coliform (E. coli)-positive repeat sample or any total coliform-positive repeat sample following a fecal coliform positive or E. coli-positive routine sample constitutes a violation of the MCL for total coliforms. For the purposes of public notification requirements in R309-220-5 this is a violation that may pose an acute risk to health. (c) For NTNC and transient non-community systems that are required to sample at a rate of less than one per month, compliance with paragraphs (a) or (b) of this subsection shall be determined for the month in which the sample was taken. (7) DISINFECTION Continuous disinfection is recommended for all water sources. It shall be required of all ground water sources which do not consistently meet standards of bacteriologic quality. Surface water sources or ground water sources under direct influence of surface water shall be disinfected and continuously monitored for disinfection residual during the course of required conventional complete treatment for systems serving greater than 3,300 people. Disinfection shall not be considered a substitute for inadequate collection or filtration facilities. Successful disinfection assures 99.9 percent inactivation of Giardia lamblia cysts and 99.99 percent inactivation of enteric viruses. Both filtration and disinfection are considered treatment techniques to protect against the potential adverse health effects of exposure to Giardia lamblia, viruses, Legionella, and heterotrophic bacteria in water. Minimum disinfection levels are set by "CT" values as defined in R309-110. (a) Each public water system that provides filtration treatment shall provide disinfection treatment as follows: (i) The disinfection treatment shall be sufficient to ensure that the total treatment processes of the system achieve at least 99.9 percent (3-log) inactivation and/or removal of Giardia lamblia cysts and at least 99.99 percent (4-log) inactivation and/or removal of viruses, as determined by the Executive Secretary. (ii) The residual disinfectant concentration in the water entering the distribution system cannot be less than 0.2 mg/L for more than 4 hours. (iii) The residual disinfectant concentration in the distribution system, measured as combined chlorine or chlorine dioxide, cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration less than or equal to 500/ml, measured as heterotrophic plate count (HPC) is deemed to have a detectable disinfectant residual for purposes of determining compliance with this requirement. Thus, the

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value "V" in the following formula cannot exceed 5 percent in one month, for any two consecutive months. V = ((c + d + e) / (a + b)) x 100 where: a = number of instances where the residual disinfectant concentration is measured; b = number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured; c = number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured; d = number of instances where no residual disinfectant concentration is detected and where HPC is greater than 500/ml; e = number of instances where the residual disinfectant concentration is not measured and HPC is greater than 500/ml. (b) If the Executive Secretary determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified in Heterotrophic Plate Count (Pour Plate Method) as set forth in the latest edition of Standard Methods for the Examination of Water and Wastewater, 1985, American Public Health Association et al. (Method 907A in the 16th edition) and that the system is providing adequate disinfection in the distribution system, the requirements of R309-200-5(7)(a)(iii) do not apply. (c) If a system utilizes a combination of sources, some surface water influenced (requiring filtration and disinfection treatment) and others deemed ground water (not requiring any treatment, even disinfection), the Executive Secretary may, based on site-specific considerations, allow sampling for residual disinfectant or HPC at locations other than those specified by total coliform monitoring required by R309-210-5.

R309-200-6. Secondary Drinking Water Standards for Community, Non-Transient Non-Community and Transient Non-Community Water. The Secondary Maximum Contaminant Levels for public water systems deals with substances which affect the aesthetic quality of drinking water. They are presented here as recommended limits or ranges and are not grounds for rejection. The taste of water may be unpleasant and the usefulness of the water may be impaired if these standards are significantly exceeded. TABLE 200-5 SECONDARY INORGANIC CONTAMINANTS Contaminant Level Aluminum 0.05 to 0.2 mg/L Chloride 250 mg/L Color 15 Color Units Copper 1 mg/L Corrosivity Non-corrosive Fluoride 2.0 mg/L (see Note below) Foaming Agents 0.5 mg/L Iron 0.3 mg/L Manganese 0.05 mg/L Odor 3 Threshold Odor Number pH 6.5-8.5 Silver 0.1 mg/L Sulfate 250 mg/L (see Note below) TDS 500 mg/L (see Note below) Zinc 5 mg/L

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Note: Maximum allowable Fluoride, TDS and Sulfate levels are given in the Primary Drinking Water Standards, R309-200- 5(1). They are listed as secondary standards because levels in excess of these recommended levels will likely cause consumer complaint.

R309-200-7. Treatment Techniques and Unregulated Contaminants. (1) The Board has determined that the minimum level of treatment as described in R309-525 and R309- 530 herein or its equivalent is required for surface water sources and ground water contaminated by surface sources. (2) For surface water systems, R309-200, 215, 505, 510, 520, 525 and 530 establish or extend treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium, and turbidity. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve: (a) at least 99.9 percent (3-log) removal and/or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to re-contamination by surface water runoff and a point downstream before or at the first customer; (b) at least 99.99 percent (4-log) removal and/or inactivation of viruses between a point where the raw water is not subject to re-contamination by surface water runoff and a point downstream before or at the first customer. (c) At least 99 percent (2-log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer. for filtered systems, or Cryptosporidium control under the watershed control plan for unfiltered systems. (d) Compliance with the profiling and benchmark requirements under the provisions of R309-215-14. (3) No MCLs are established herein for unregulated contaminants; viruses, protozoans and other chemical and biological substances. Some unregulated contaminants shall be monitored for in accordance with 40 CFR 141.40.

R309-200-8. Approved Laboratories. (1) For the purpose of determining compliance, samples may be considered only if they have been analyzed by the State of Utah primacy laboratory or a laboratory certified by the Utah State Health Laboratory. However, measurements for pH, temperature, turbidity and disinfectant residual, daily chlorite, TOC, UV254, DOC and SUVA may, under the direction of the direct responsible charge operator, be performed by any water supplier or their representative. (2) All samples shall be marked either: routine, repeat, check or investigative before submission of such samples to a certified lab. Routine, repeat, and check samples shall be considered compliance purposes samples. (3) All public water systems shall either: contract with a certified laboratory to have the laboratory send all compliance purposes sample results, with the exception of Lead/Copper data, to the Division of Drinking Water, or shall inform the Division of Drinking Water that they intend to forward all compliance purposes samples to the Division. Each public water system shall furnish the Division of Drinking Water a copy of the contract with their certified laboratory or inform the Division in writing of the public water system's intent to forward the data to the Division. (4) All sample results can be sent either electronically or in hard copy form.

KEY

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drinking water, quality standards, regulated contaminants

Date of Enactment or Last Substantive Amendment December 9, 2002

Notice of Continuation April 16, 2001

Authorizing, Implemented, or Interpreted Law 19-4-104; 63-46b-4