beak 42 Arrow Road Tel (519)763-2325 international Guelph, Ontario Fax (519) 763-2378 incorporated Canada N1 K 1 S6

15 May 1998 Beak Reference No: 7253. 1

Mr. Thomas E. Roy SDMS DocID

Aries Engineering, Inc 46 South Main Street Concord, NH 03301

Reference: Fletcher's Paint Superfund Site, Application of ISTD Technology

Dear Mr. Roy:

Further to our recent discussions regarding the application of the in situ thermal desorption (ISTD) technology at the Fletcher's Paint Superfund Site (the "Site") in Milford, NH we are pleased to provide additional details regarding the Site-specific application of the technology. This letter provides information on: (1) the basis for determining the location of the ISTD exclusion zone; (2) operating experience and plans for treating resin in soil; (3) health & safety and emergency response issues related to the use of the ISTD technology at the Site; (4) treating soil beneath existing buildings; and (5) recent operating experience with the ISTD technology. In addition, this letter provides a summary of features and advantages of the ISTD technology relative to the low temperature thermal extraction (LITE) process. The information provided in this letter has been provide to us from Dr. Harold Vinegar of Shell Technology Co. and others from TerraTherm Environmental Services Inc.

ISTD Exclusion Zone Location Determination

If the ISTD technology is selected to treat soils at the Site, it is anticipated that any soil which requires cleanup and is located within about eight feet of the property boundary would be excavated, moved to the central area of the Site, and treated using the ISTD thermal wells. The cover over the ISTD thermal blanket and/or thermal wells would extend four feet out beyond the edge of the soil being treated. In addition, a four foot wide access corridor would be left between the edge of the cover and a perimeter fence to be installed along the property boundary. The access corridor would allow personnel access between the thermal blanket and the perimeter fence for maintenance and monitoring purposes. The perimeter fence would define the location of the exclusion zone around the ISTD equipment.

A distance of four feet between the cover and the perimeter fence is appropriate because: (1) the temperature of the surface soil immediately beyond the cover is not elevated significantly above ambient and contact with this soil need not be restricted; and (2) no vapors are released from the

beak international incorporated

Mr. Thomas Roy Reference: 7253.1 Aries Engineering, Inc. 2 Date: 15 May 1998

soil outside the cover because: (i) the cover extends out over the soil being heated, and (ii) the thermal blanket and thermal wells maintain a vacuum over and within this soil.

Several photographs of ISTD thermal wells and thermal blankets are attached to this letter. Photographs 1 and 2 show a number of thermal wells in operation directly across a small road from residences at a site in Portland, Indiana. Photograph 1 shows a number of individuals standing on soil directly adjacent to the cover while thermal wells were in operation at the site. Photograph 3 show a thermal blanket installed to treat soil near housing at the Mare Island Naval Shipyard in California. Photograph 4 shows the equipment in close proximity to an existing building. Photograph 5 shows thermal wells installed to treat soil hi an alley between an existing building and the backyard fences of residential properties at a site in Eugene, Oregon. Photograph 6 shows thermal wells being installed at a site in Eugene, Oregon adjacent to a roadway and residential housing. These photographs demonstrate that the ISTD technology has been applied or is currently being applied at sites hi similar proximity to public roadways and residences to that planned at the Site.

At our meeting in April, Lee May hew had raised concerns regarding the size of the exclusion zone at the Cape Girardeau Site and asked if the exclusion zone for the ISTD technology applied at the Fletcher's Site would be the same size. The Health and Safety Plan (HSP) for the Cape Girardeau Site established an exclusion zone of 50 feet from the area where the ISTD equipment was in operation. The size of the exclusion zone was not established to address concerns about the proximity to the ISTD equipment to areas where the public would have access, but was established based on the fact that the area to be treated was located a considerable distance from existing perimeter fencing which was used to define the exclusion zone for convenience purposes.

Experience and Plans for Treating Resin Type Materials

TerraTherm has successfully conducted treatability tests on poly amide resin material similar to that which is found at the Fletcher's Paint Site. If the ISTD technology is selected to treat soils at the Site, it is anticipated that additional treatability testing would be conducted on soil samples containing resin material from the site prior to on-site treatment. These tests would confirm that: (1) the resin material can be completely destroyed by the ISTD technology; (2) the presence of the resin material will not interfere with the safe operation of the ISTD technology; and (3) no potentially problematic products of incomplete combustion are produced during the treatment of soil containing resin material. If the treatability testing demonstrates that the resin material in the soil will not respond to treatment as desired then soils containing resin material would be excavated and transported off-site for disposal prior to the implementation of the ISTD technology at the Site.

beak international incorporated

Mr. Thomas Roy Reference: 7253.1 Aries Engineering, Inc. 3 Date: 15 May 1998

Health and Safety & Emergency Response Issues Raised by the Town of Milford

The HSP for the Fletcher's site will be similar to the HSP that was prepared for the Cape Girardeau Site and which was included in a letter to you from Michael lanniello and Dr. Richard Sheldon of General Electric dated December 12, 1997. It is anticipated that the notification and training provided to emergency services in the Milford area would also be similar to that provided for emergency services in the area of the Cape Girardeau Site and other sites where the ISTD technology has been successfully applied. At the Cape Girardeau Site, Shell provided a tour of the facility and reviewed the HSP and all emergency procedures with the fire department. This ensured that the fire department could handle any emergency at the Site, if there was ever a need. There are no special hazardous materials management or training requirements for the ISTD equipment beyond that which would be required for the use of equipment for the treatment of soils containing PCBs using low temperature thermal extraction technology.

Treatment of Soil Beneath Existing Buildings

The ISTD technology is currently being used to treat soil beneath existing buildings and has been used in the past to treat soil directly adjacent to buildings. Treatment of soil beneath existing buildings requires the Installation of thermal wells through the existing floor slab. Photograph 7 shows an array of thermal wells installed through the floor of an existing building. Given the capability of the ISTD technology it is not necessary to demolish the building at the Elm Street Site in order to treat soil beneath the building.

Comparison of ISTD and LTTE

The attached Table 1 presents a summary of features and advantages of the ISTD technology relative to the low temperature thermal extraction (LTTE) technology at the Site. Attachment 1 presents a copy of the executive summary of a report prepared by Focus Environmental Inc. which describes the results of a treatability study on the use of an LTTE process to treat landfill material containing PCBs. The report highlights some of the operating difficulties that may be encountered during the implementation of LTTE for landfill material. Some of the major issues with the implementation of the LTTE technology include: (1) difficulties with material handling related to landfill debris; (2) fugitive emissions related to the excavation, processing and transport of material to be treated; and (3) potentially explosive environments in the ex situ thermal desorption equipment which could exist due to the significant mass of organic material present. The use of the ISTD technology avoids potential problems associated with these issues. We believe that there are many significant advantages of the ISTD technology for the residents of the Town of Milford as summarized on Table 1.

beak international incorporated

Mr. Thomas RoyAries Engineering, Inc. 4

Reference: 7253.1 Date: 15 May 1998

Recent Operating Experience with the ISTD Technology

Attachment 2 presents information on recent operating experience with the ISTD technology and includes: (1) a project profile on the use of the ISTD technology at a bulk fuel storage facility in Eugene, Oregon; (2) a project profile on the use of the ISTD technology at the Bay Area Defense Conversion Action Team (BADCAT) project at the Mare Island Naval Shipyard in Vallejo, California; and (3) a copy of the Final Report on the demonstration of the ISTD technology at the Mare Island Naval Shipyard. This additional information provides further evidence that the ISTD technology can be applied safely and effectively at the Fletcher's Paint Site in Milford.

We trust that this information will be of interest to you, and if you have any additional questions or concerns we would be pleased to discuss them with you.

Sincerely,

BEAK INTERNATIONAL INCORPORATED

Thomas A. Krug, M.Sc., P.Eng. Associate, Senior Project Manager

cc: Lee Mayhew, Town of Milford John Peltonen, SPB&G Cheryl Sprague, EPA Antoinette Powell, EPA Stergios Spanos, NHDES Michael lanniello, GE Richard Sheldon, GE Harold Vinegar, Shell Oil Doug Day, TerraTherm

TABLE 1: SUMMARY OF FEATURES AND ADVANTAGES OF ISTD OVER LTTE Fletcher's Paint Superfund Site, Milford, NH

Features of ISTD Relative to LTTE

Minimal soil excavation required

Minimal stockpiling or moving soil during treatment

Soil treated in the ground and not above the ground

More compact above ground treatment equipment

PCBs are destroyed on-site

Lower cost

notes: ISTD - in situ thermal desorption

Advantages of ISTD over LTTE

lower potential for worker and community exposures to fugitive dust

less noise from earth moving equipment

less risks from construction activities

no need to stockpile soil in Keyes Field

lower potential for trespasser exposures to soil with PCBs

lower potential for worker and community exposures to fugitive dust

minimal disruption in the use of Keyes Drive

minimal transport of soil in the community

no noise from heavy earth moving equipment while soil is being treated

soil processing and treatment not affected by debris in soil

less risk of explosion from treatment of soil with a high organic content because of low oxygen level in soil

treatment can be conducted without using space in Keyes Field

no potential for spill of condensate containing high concentrations of PCBs during storage or transport

lower cost for all responsible parties

LTTE - low temperature thermal extraction (ex situ thermal desorption) PCBs - polychlorinated biphenyls

tk/Retcher's/1998/Communication/Leners/Tbl Feature_Adv 1ST (Converted)! 15 May 1998

7253.2

i

4

Photograph 1:

Thermal wells in operation at a site in Portland, Indiana.

Photograph 2:

Thermal wells in operation near residences at a site in Portland, Indiana.

iwiii II- T i l - ' ^ n m H

Photograph 3:

Thermal blanket in operation near base housing at the Mare Island Naval Shipyard in California.

Photograph 4:

Thermal well field demonstration at Mare Island Naval Shipyard.

Photograph 5:

Thermal wells installed to treat soil in an alley adjacent to backyards of residential properties, Eugene, Oregon.

Photograph 6:

Thermal wells installed to treat soil in close proximity to a road and residential building, Eugene, Oregon.

Photograph 7:

Thermal wells installed to treat soil beneath existing building.

Attachment 1

Executive Summary from, "Thermal Treatability Study Report, American Chemical Services (ACS) Site"

prepared by Focus Environmental Inc.

- 7 -05-1998 FocusEnvironmental

Hngineering Solutions to Environmental Problems

January 13, 1998

Ms. Sheri Bianchin, RPM Mail Code SR-J6 U. S. EPA, Region V 77 West Jackson Chicago, IL 60604-3590

Re: Thermal Treatability Study Report Submittal American Chemical Services (ACS) NPL Site Griffith, Indiana

Dear Ms. Bianchin:

The attached report is the second of a two-part submittal reporting on the ex-situ Low Temperature Thermal Treatment treatability studies conducted at the ACS site during the last six months. This report, in conjunction with the Pretreatment/Materials Handling Study (PMHS) report submitted on October 31,1997, provides new information about the site waste materials and indicates that the basis for the required remedy in the Record of Decision (ROD) has changed significantly. Based on the new information, Focus has concluded that ex-situ Low Temperature Thermal Treatment is not an appropriate technology for remediating the site.

I understand a meeting is being organized to allow a more detailed discussion of the findings from these studies with the EPA and State of Indiana.. I look forward to that meeting. If you have any questions regarding this submittal, please direct them to Peter Vagt at (630)691-5020.

Sincerely,

Paul Sadler Senior Project Engineer Focus Environmental, Inc.

Attachment: Draft Thermal Treatability Study Report (3 copies)

cc: S. Mrkvika, B&V (2 copies) Vince Epps, IDEM (2 copies) Marta Richards, EPA (1 copy) ACS Technical Committee (1 copy)

9O5O Executive Park Drive Suite A-202 Knoxville, TN 37923 (423)694-7517 (423)531-8854

THERMAL TREATABILITY STUDY REPORT

AMERICAN CHEMICAL SERVICE (ACS) SITE

Submitted to:

US EPA REGION V

Submitted by:

ACS RD/RA EXECUTIVE COMMITTEE

January 12,1998 Focus Project No. 119603

PREPARED BY:

FOCUS ENVIRONMENTAL, INC. 9050 EXECUTIVE PARK DRIVE SUITE A-202 KNOXVILLE, TENNESSEE 37923 (423)694-7517

American Chemical Service Site

Thermal Treatability Study Report

1.0 EXECUTIVE SUMMARY

Based on new information obtained from the treatability studies conducted for the American Chemical

Services (ACS) NPL site, the remedy required in the Record of Decision (ROD) is not an appropriate

remedy. Specific technical information supporting this conclusion includes:

Only 30 volume percent of the contaminated materials required to be managed as waste by the current ROD could be backfilled at the site after LTTT treatment. The remaining 70 volume percent would have to be removed from the site for one reason or another (i.e., drums, debris, and metals contaminated soil).

Excavation of the contaminated materials would produce significant fugitive emissions that could exceed health risk standards both on-site and offsite.

Potentially explosive environments could exist in a thermal desorption system due to the significant mass of organics vaporized into the offgas stream during treatment of site soils.

"Waste" processed in a thermal desorber would produce significant quantities of residuals that the ROD requires to be disposed of offsite. These residuals are a result of a significant organic content in the feed materials. Disposal of these residuals would significantly increase the cost of implementing the remedy.

Changes in the quantities of contaminated materials required to be disposed of offsite, will significantly increase the cost of implementing the specified remedy.

1.1 BACKGROUND

The ROD for the ACS NPL Site, located in Griffith Indiana, specifies that Buried Waste at the Site is to be

remediated by Low Temperature Thermal Treatment (LTTT). "Buried waste" is defined in the ROD as

material that has VOC concentrations greater than 10,000 ppm or PCB concentrations greater than 10

ppm. Li I I is a thermal desorption process in which contaminated material is heated sufficiently to

desorb contaminants from the matrix, but not heated to the degree that the contaminants are decomposed

or incinerated. In an LTTT system, the desorbed contaminants are recovered for further treatment or

destruction in an afterburner.

Previous investigations indicated that drums, debris, and municipal landfill debris are intermingled with the

"buried waste" and "contaminated soil" at the ACS site. A treatability test program was conducted to

better define the characteristics of materials in the Offsite Containment Area and determine the

applicability of thermal desorption for the ACS site. The treatability test program was conducted in two

separate phases; 1) a Pretreatment/Material Handling Study (PMHS) and 2) a Thermal Treatability Study

(TTS).

TTS-rep.lwp 1 119603

American Chemical Service Site

Thermal Treatability Study Report

1.2 PMHS RESULTS

The primary purposes of the PMHS were to determine the extent of the drum disposal region in the Offsite

Containment Area, to assess the degree to which debris could be screened from site soils, and to collect

samples of "buried waste" for the TTS. The results of the PMHS, detailed in the October 28, 1997 report

by Focus Environmental, showed that approximately 44 volume percent of the "buried waste" at the ACS

Site was debris and drums which are not amenable to treatment by thermal desorption technologies. The

remaining 56 volume percent have to be processed by LTTT. Approximately half of the soils that would

be treated by LTTT (approximately 26 volume percent of the total material) is contaminated with metals

and would have to be disposed of offsite according to the ROD. This means that a total of 70 volume

percent of the contaminated materials at the site will require disposal offsite for one reason or another

according to the current ROD.

1.3 TTS TEST AND RESULTS

The TTS tested the application of low temperature thermal desorption technologies to the soil portion of

the "buried waste". The TTS was executed in three steps. The first step was sample preparation and

characterization. The work plan called for two types of samples to be developed from the site materials:

one to represent the "typical case" site materials and the other to represent the "worst case" materials.

Two composite soil samples were prepared from the individual samples collected during the PMHS to

represent "worst case" and "typical case" waste soils for PCB's. The TTS was conducted on these two

samples. A composite sample representing "worst case" VOC or SVOC contamination could not be

generated from the samples collected because none of the samples contained VOC's or SVOC's at the

highest concentrations previously detected at the site. Analytical results for VOC's in the buried waste

samples collected during the Rl were 40 times higher than the concentration of VOC's in the samples

collected during the PMHS. The two composite soil samples contained detectable concentrations of

PCB's, tetrachloroethene, bis(2-ethylhexyl)phthalate, isophorone, and napthalene in excess of the cleanup

standards. Several other contaminants of concern (COC's) were not detected, but the analytical detection

limits were in excess of the respective cleanup standards. The total organic content of these two samples

averaged approximately 8 wt%.

The second step of the TTS was to conduct tray testing on both of the composite samples to document

the residual COC concentrations after heating the soil material to four different temperatures (500, 700,

900, and 1,100F). The results from the tray tests indicate that the cleanup standards can be attained for

the prepared samples at soil treatment temperatures of 700F or higher for all COC's with analytical

TTS-rep.lwp 2 119603

American Chemical Service Site

Thermal Treatability Study Report

detection limits that are less than the cleanup standard. There were several COC's with analytical

detection limits in excess of the cleanup standards. Attainment of the cleanup standards could not be

demonstrated for these COC's. The tray test results were also used to establish target soil temperatures

for the third step of the TTS which was rotary thermal apparatus (RTA) testing.

The primary purpose of RTA testing (the third step) was to characterize the offgas and residuals resulting

from heating of the soils at different soil treatment temperatures and using different purge gasses (air and

nitrogen). The results from these tests indicate that approximately 65 wt% of the organic carbon in the

starting soil partitions to the offgas at a soil temperature of 900F as opposed to 30 wt% at 700F. There

was no apparent impact on partitioning of organic carbon to the offgas when nitrogen was used as the

purge gas instead of air. For soils that contain higher concentrations of VOC's or SVOC's, which have

been detected at the site, an even higher percentage of the carbon would partition to the offgas than was

measured during the TTS.

Total hydrocarbons (THC) and carbon monoxide (CO) were measured in the offgas at concentrations in

excess of 30,000 and 70,000 ppmv, respectively. The concentration of CO in the offgas was reduced to a

maximum of approximately 25,000 ppmv when nitrogen was used as the purge gas in place of air.

Analysis of bag samples indicates that the THC in the offgas consists primarily of light hydrocarbons (i.e.,

methane, ethane, ethylene, and propylene/propane). Hydrogen was measured in the offgas at a

concentration in excess of 140,000 ppm for the 900F test run with an air purge.

1.4 CONCLUSIONS

The results of these studies provide the basis for concluding that ex-situ low temperature thermal

desorption is not an appropriate technology to remediate the ACS site. Specific conclusions supporting

this statement include:

A) Material handling issues will be significant at the site including:

Debris and drums which are not amenable to treatment by thermal desorption make up a much greater proportion of the "buried waste" at the site (approximately 44 volume percent) than was previously known. The majority of the debris is municipal debris that cannot be effectively washed per the requirements of the ROD. This debris might have to be transported offsite for disposal at a RCRA TSDF. This would significantly increase the cost of implementing the ROD remedy. Another 26 volume percent of the contaminated materials at the site are contaminated with metals and would require offsite disposal per the current ROD. This means a total of approximately 70 volume percent of the contaminated materials at the site would end up being removed from the site even if LTTT were implemented.

TTS-rep.lwp 3 119603

American Chemical Service Site

Thermal Treatability Study Report

High concentrations of VOCs exist at the site and treatability tests show that a high percentage of these VOCs will be lost as fugitive emissions during material handling activities, potentially resulting in relatively high exposures to workers and at offsite areas.

Soils commingled with the drums will have significantly higher organic content than the soils screened in the PMHS and could be problematic due to their sticky nature and high fugitive emissions during screening operations.

Soils excavated from the region of the upper aquifer could be difficult to handle due to the high water content.

B) Very high organic content (approximately 8 wt%) in the feed soil to a thermal desorber would result in the following problems:

Development of potentially explosive environments within the thermal desorption process equipment.

Premature condensation of organics in the emission control system that can cause significant operational problems (plugging, fires, downtime for cleanout).

Generation of large quantities of treatment residuals (organic liquids, organic sludges, and activated carbon) that require offsite disposal unless a thermal oxidizer can be used as an emission control device.

Significant emissions of total hydrocarbons (THC) and carbon monoxide (CO) (concentrations of THC and CO were as high as 30,000 and 70,000 ppmv in the offgas, respectively, during the RTA testing) unless a thermal oxidizer could be used to control the emissions.

Site soils contain concentrations of PCBs in excess of 50 mg/kg (soil samples collected during the PMHS averaged 80 mg/kg with a maximum of 330 mg/kg). Use of a thermal oxidizer on a thermal desorption system may require a detailed evaluation of alternative treatment technologies to comply with the State of Indiana statutes annotated (13-17-10-2 and 13-17-10-3) and may not be allowed under Indiana law. In addition, if a thermal oxidizer were used on the thermal desorption system, the unit would be required to demonstrate 99.9999 destruction and removal efficiency (ORE) which would be difficult to demonstrate at this site because of low PCB concentrations.

Thermally processing ACS site soils that contain metals will not provide treatment for those metals, but may increase their mobility (particularly lead) based on the results of the ITS. Thermally processing soils that contain metals will likely increase the quantity of soils requiring stabilization under the current ROD and result in increased project costs.

C) Acid gasses formed during thermal processing from the sulfur and chlorine contained in site soils would pose significant corrosion problems for emission control system equipment.

D) Cleanup standards for some of the ROD defined contaminants cannot be demonstrated using standard analytical techniques due to the analytical detection limits being greater than the cleanup standards. These COC's include CPAH's, 2,4-dinitrotoluene, 2,6-dinitrotoluene, bis(2-chloroethyl)ether, and hexachlorobenzene. This issue must be addressed regardless of the technology applied to the site.

TTS-rep.lwp 4 119603

Attachment 2

(1) Project Profile - Eugene, Oregon

(2) Project Profile - Bay Area Defense Conversion Action Team (BADCAT) Project at the Mare Island Naval Shipyard in Vallejo, California

(3) Final Report - Bay Area Defense Conversion Action Team (BADCAT) Project at the Mare Island Naval Shipyard in Vallejo, California

(5) PROJECT PROFILE Bulk Fuel Storage Terminal

PROJECT LOCATION: Eugene, Oregon

PROJECT ESTIMATED TIMEFRAME: January 1998 - May 1998

REGULATORY AGENCY INVOLVED: Voluntary Cleanup Action - Oregon DEQ

PROJECT MANAGER/KEY PERSONNEL: TerraTherm - Harold Vinegar, Tom Cason, John Kohli, Denis Conley, Darlene Venable

PROJECT DESCRIPTION: type, size, setting of site: The site is a voluntary cleanup where petroleum hydrocarbons are present in the soil and ground water on a one-acre site adjacent to railroad tracks in a light industrial/commercial area of Eugene. The area is bounded on one side by residential properties. The contamination extends under and adjacent to the warehouse facility.

nature and extent of contamination: The contaminants have been identified as benzene, gasoline, and diesel and have been detected to depths of 12 feet below ground surface, including areas underneath buildings. Impacted soils were also found in an adjacent alley. Maximum concentrations of diesel and gasoline in the soil are 9,300 mg/kg and 3,500 mg/kg, respectively.

remedial requirements: The goal is to remediate to 100 ppm TPH across the site.

permits or regulatory requirements: Air permit

health and safety measures: Onsite and boundary surveys are taken for dust and VOC emissions. CEMs are used on process equipment to verify clean stack emissions.

thermal treatment process, site set up and equipment utilized: TerraTherm is using its Diesel Remediation System to treat this complex site without excavating or removing any soil. In this application, the system consists of 277 Vacuum/Heater Wells, 484 Heater Wells, 11 individual processing units, a flameless thermal oxidizer and a carbon-bed polishing unit. Heating elements installed in the wells will be operated at up to 1,600F and raise the soil temperature to as high as 500F. The heat vaporizes the contaminants in the soil, and the vapors are then passed through the surface treatment system.

The remediation area is divided into 11 separate sections. Individual treatment units for each area consist of a pre-heater, catalytic converter, blower and carbon bed. These treatment units are connected by a manifold system to the final treatment facility, which includes a 60-hp blower, flameless thermal oxidizer and carbon bed. Virtually the only exhaust from the treatment system is water vapor and CO2.

The manifold system is comprised of over 3,000 feet of insulated 4-inch-diameter and 500 feet of 8-inchdiameter carbon steel piping. Eleven insertion heaters are used to ensure that contaminants remain in a vapor phase prior to treatment.

A mobile well controller system is used to monitor all 761 wells, the process skids, and the treatment system. A total of 29 Vacuum/Heater Wells and 73 Heater Wells are installed within an existing warehouse and office complex to remediate soils impacted beneath the buildings.

air and water pollution controls: In addition to the wells operated on-site, over 40 Vacuum/Heater and 20 Heater Wells are used to remediate impacted soils in an alley adjacent to the site. A dewatering system was used to lower the groundwater prior to initiation of thermal operations. The dewatering system pumped water from the ground, and the recovered liquids were chemically treated to destroy any contaminants.

PROJECT STATUS: On-going

CLIENT REFERENCES: Frank Fossati (714)427-3402

CONSULTING ENGINEER REFERENCES: Hart Crowser Stacy Callison, P.E. (503)620-7284

REGULATORY AGENCY REFERENCES: Frank Belyea Oregon DEQ - (541 )686-7838

P R O J E C T

^

TERRATHERM* ENVIRONMENTAL SERVICES INC PROFILE PROJECT: Remediation of PCBs at

former U.S. Naval Base LOCATION: Mare Island,

Naval Shipyard Vallejo, California

TIME OF OPERATIONS: August-November 1997

REGULATORY AGENCIES: US EPA, California EPA, Bay Area Air Quality Management District

BACKGROUND: The demonstration was conducted as a joint

collaboration between TerraTherm, the San Francisco Bay Area Defense Conversion Action Team (BADCAT) and the U.S. Navy, with RT Environmental Services serving as general contractor for TerraTherm. Observers included the Bay Area Economic Forum and the Toxics Program Officer for the Senior Environmental Employment Program.

BADCAT is responsible for developing effective methods to remediate contaminants found in abandoned military bases in the San Francisco Bay Area. Following remediation efforts, the sites will be opened to possible private development.

TerraTherm was one of several firms selected by BADCAT to demonstrate applicable new remediation technologies. The objective was to demonstrate In Situ Thermal Desorption (ISTD) to the agencies involved and prove ISTD's effectiveness in removing Polychlorinated Byphenyls (PCBs) from the soil.

More than 100 specially invited guests representing government regulators, elected officials, military personnel and environmental consultants attended a series of presentations during the operation.

SITE DESCRIPTION:

The test site was located at the former Mare Island Naval Shipyard in Vallejo, California. Soil contamination ranged from an average of 54 parts per million (ppm) to

April 1998

The area treated was adjacent to a former electrical and motor fabrication building, and included a nearby grease trap and an additional parking lot test area.

REMEDIATION OPERATIONS:

The project began in August 1997, with an expedited Toxics Substance Control Act (TSCA) air permit provided by the California EPA.

TerraTherm's ISTD process utilized electric soil heating and vapor treatment components. Soil heating elements consisted of Thermal Wells for deep remediation and Thermal Blankets for excavated soil treated at the surface.

The ISTD process is a clean, closed system that is simple, fast and works in place. It is designed to be a quiet, low profile operation with little neighborhood disruption. The process has high removal efficiency since it does not rely on fluid injections to mobilize target compounds. It is based on thermal conduction through the soil to provide a uniform heat transfer method. It works in tight soils, clay layers or in heterogeneous soils with wide variations in permeability or moisture content.

A network of twelve Thermal Wells remediated contaminants to a depth of 14 feet.

a maximum concentration of 2,200 ppm of PCBs, specifically Aroclor 1254 and 1260.

The demonstration consisted of 12 Thermal Wells,

drilled to an operational depth of 14 feet around the

former grease trap area next to the facility. Later two

Thermal Blankets were used to remediate impacted soil

from the floor drain excavation that was spread on the

surface to a depth of one foot.

The Thermal Wells and Thermal Blankets were

operated separately. Soil temperatures were brought to

600F with both the Thermal Wells and Thermal Blankets

in order to destroy most of the contaminants in place.

An MU 125 mobile processing unit removed

process gases by way of a vacuum system through

a flameless thermal oxidizer and activated charcoal beds.

Air controls included secondary and tertiary treatment

via the MU 125 trailer through the oxidizer and the carbon

beds, which provided redundant treatment of the recovered

process gases. In addition, an emergency electrical genera TerraTherm used two Thermal Blankets during seven days of sustained remediation

to reduce contaminant levels from 2,200 ppm to non-detectable residual readings of tor was located on the trailer to keep critical equipment less than 0.033 ppm.

operating in the event of a disruption to electric utility

power. Since contaminants were above the water table,

no dewatering was required

REMEDIATION RESULTS:

I

Remediation was completed in less

time than anticipated. The Thermal Wells

were operated for 37 days, while the

Thermal Blankets ran for seven days.

The thermal treatment was concluded

in November of 1997.

Verification sampling of the areas treated by the Thermal Wells and Thermal Blankets were conducted following the demonstration. The original clean-up goal had been set at 2 ppm residual PCB concentrations. Test results indicated that TerraTherm had substantially exceeded this goal by achieving non-detectable levels (less than 0.033 ppm) in all the areas sampled.

Technicians monitor the MU125 process unit, which captures and destroys any vapors not oxidized Please contact TerraTherm for more in the soil.

information on In Situ Thermal Desorption

technology and its applications.

^

An Affiliate of TERRATHERM" ENVIRONMENTAL SERVICES INC. Shell Technology Ventures Inc.

10077 Grogan's Mill Rd. The Woodlands, Tx. 77380 Tel: (800) 200-5288 Fax:(281)296-1049 Website vw^Aw.terratherm.com I

http:vw^Aw.terratherm.com

Environmental Services, Inc.

February 5, 1998

Ms. Karla Jenkins Naval facilities engineering Service center Code ESC414 1100 23rd Avenue Port Hueneme, CA 93043 (805) 982-2636

RE: BADCAT IN SITU THERMAL DESORPTION DEMONSTRATION SUBMITTAL OF FINAL REPORT

Dear Karla:

On behalf of TerraTherm Environmental Services, Inc., and RT Environmental Services, Inc., I am pleased to enclosed is a copy of the final report for the BADCAT ETP In Situ Thermal Desorption Demonstration. We understand that you will copy and distribute the report to project participants within the Navy, BADCAT, and regulatory agency personnel who took part in the demonstration.

We appreciate your assistance in making the Demonstration a success. Please feel free to call with any questions or comments you may have in your review of the enclosed report

Sincerely,

William Silverstein, P.E Senior Engineer

C: Jim Steed/TerraTherm Gary Brown/RT

194O-05\badcat251Over

215 West Church Road King of Prussia. PA 19406 (610) 265-1510 Fax: (610) 265-0687

E-Mail RTENVBAOl.COM Web Address http://www.RTENV.COM

http:http://www.RTENV.COMhttp:RTENVBAOl.COM

FINAL REPORT FOR

ENVIRONMENTAL TECHNOLOGY PARTNERSHIP (ETP) DEMONSTRATION

IN SITU THERMAL DESORPTION

PREPARED FOR:

U.S. NAVY AND BAY AREA DEFENSE CONVERSION ACTION TEAM (BADCAT)

PREPARED BY:

TERRATHERM ENVIRONMENTAL SERVICES, INC. 10077 GROGAN'S MILL ROAD, SUITE 475

THE WOODLANDS, TX 77380

AND

RT ENVIRONMENTAL SERVICES, INC 215 WEST CHURCH ROAD

KING OF PRUSSIA, PA 19406

FEBRUARY 5,1998

Table of Contents

Executive Summary 6

1. Introduction 8

1.1 Background Information 8 1.2 Official DoD Requirement Statement(s) 8 1.3 Objectives of the Demonstration 9 1.4 Regulatory Issues 11 1.5 Previous Testing of the Technology 12

2. Technology Description 13

2.1 Description 13 2.2 Strengths, Advantages, and Weaknesses 17 23 Factors Influencing Cost and Performance 18

3. Site/Facility Description 21

3.1 Background 21 3.2 Site/Facility Characteristics 21

4. Demonstration Approach 29

4.1 Performance Objectives 29 4.2 Thermal Well System Physical Setup and Operation 31 43 Thermal Blanket System Physical Setup and Operation 41 4.4 Operating Conditions and Control Interlocks 43 4.5 Residuals Management 46 4.6 Demobilization and Site Restoration 46 4.7 Sampling Procedures 47 4.8 Analytical Procedures 47

5. Performance Assessment 50

5.1 Performance Data 50 5.2 Data Assessment 59 5.3 Technology Comparison 60

6. Cost Assessment 62

6.1 Cost Performance 62 6.2 Cost Comparisons to Conventional and Other Technologies 62

7. Regulatory Issues 64

7.1 Approach to Regulatory Compliance and Acceptance 64

8. Technology Implementation 66

8.1 DoDNeed 66 8.2 Transition 66

9. Lessons Learned 67

10. References 68

Appendix A Points of Contact .69

Appendix B Data Archiving and Demonstration Plan(s) 71

Appendix C Laboratory Data and Validation Reports 72

TABLES

2-1 Summary of Cost and Performance Factors 20

3-1 Target Compound Concentrations and Preliminary Remedial Goals 26

4-1 Demonstration Operations Chronology 32

5-1 Pre-Treatment and Post-Treatment Soil Sampling Results (Thermal Wells) 51

5-2 Pre-Treatment and Post-Treatment Soil Sampling Results (Thermal Blankets) 52

6-1 Construction and Operating Costs for ISTD Remediation of a 1,000 Ton Site 63

FIGURES

2-1 Thermal Well System Schematic 15

2-2 Thermal Blanket System Schematic 16

3-1 Site Location 22

3-2 Demonstration Area Plan 24

4-1 Thermal Well Array and Thermocouple Layout 36

4-2 Thermal Blanket Assembly and Thermocouple Layout 37

4-3 Mechanical Plan 38

4-4 Process Flow Diagram 39

4-5 Thermal Well Demonstration Sample Location Plan 48

4-6 Thermal Blanket Demonstration Sample Location Plan 49

5-1 Thermal Well Demonstration Soil Temperatures 54

5-2a Thermal Blanket #1 Demonstration Soil Temperatures 55

5-2b Thermal Blanket #2 Demonstration Soil Temperatures 56

5-3a Continuous Emissions Monitoring System Output CO, CO:, and THC 58

5-3b Continuous Emissions Monitoring System Output - Dry O2 and Wet Oi 59

Executive Summary

This report describes the successful demonstration of In Situ Thermal Desorption (ISTD) to remove and destroy PCBs from soils in situ. The demonstrations of Thermal Blankets and Thermal Wells were conducted at the former Mare Island Naval Shipyard by TerraTherm Environmental Services and RT Environmental Services, in cooperation with the U.S. Navy and the Bay Area Defense Conversion Action Team (BADCAT) Environmental Technology Project (ETP).

The ISTD technology is straightforward in operation, using the direct application of heat supplied by electrical heater elements to raise the temperature of soils in situ to the boiling point of the organic contaminant targeted for removal. Heat is applied through the use of Thermal Wells (to heat soil radially outward from each well) or Thermal Blankets (to heat soils downward from the surface). Both forms of the technology were demonstrated on the Mare Island Installation Restoration Site 11 (IR11). In each case, any vapors created are drawn through a vacuum collection system and destroyed/treated vising a flameless thermal oxidizer with vapor phase activated carbon polishing. The system was controlled and monitored using a programmable logic controller (PLC) and continuous emissions monitoring system (CEM).

Soils at the Thermal Well Demonstration area, adjacent to a former electrical shop, were impacted with Polychlorinated Biphenyl (PCB) Aroclors 1254 and 1260, and had an average pretreatment total PCB concentration of 54 milligrams per kilograms (mg/kg). Samples collected within the demonstration area during the Remedial Investigation showed a maximum concentration of 2,300 mg/kg. These soils were successfully treated to significantly below the target concentration of 2 mg/kg. The Thermal Well demonstration was conducted using a network of 12 wells drilled to a depth of 14 feet. After reaching the target soil treatment temperature of 600F over a treatment period of 37 days, all post-treatment soil samples had non-detectable PCB concentrations (less than 0.033 mg/kg).

Soils used in the Thermal Blanket Demonstration were impacted by the release of an oily sludge with a total PCB concentration of 24,000 mg/kg. These soils were also successfully reduced from a pre-treatment average PCB concentration of 21 mg/kg to below the target concentration of 2 mg/kg. The Thermal Blanket test was conducted using two adjacent 8 foot by 20 foot heating units, and treated soils to a depth of 12 inches over a period of 7 days. Again, all post-treatment soil samples had non-detectable PCB concentrations (less than 0.033 mg/kg).

The ISTD system has been demonstrated to be an effective method for treatment of a wide range of problematic organic contaminants. The technology is expected to facilitate future treatment of

sites contaminated with PCBs, pesticides, coal tars, wood treating wastes having Polynuclear Aromatic Hydrocarbons (PAHs), and other organic contamination. The technology offers on-site destruction of contaminants, and allows for rapid treatment of deep contamination adjacent to, and even under, structures, without the need for excavation.

1.0 Introduction

1.1 Background Information

This section introduces the Bay Area Defense Conversion Action Team (BADCAT) Environmental Technology Project (BADCAT ETP) and the In Situ Thermal Desorption (ISTD) technology. The introduction includes an overview of the BADCAT ETP and a brief discussion of how ISTD meets the need for emerging and innovative environmental technologies to assist hi expediting remediation of the 12 closing military bases in the San Francisco Bay Area.

The ISTD technology is straightforward in operation, using the direct application of heat supplied by electrical heater elements to raise the temperature of soils in situ to the boiling point of the organic contaminant targeted for removal. Heat can be applied through the use of Thermal Wells (to heat soil radially outward from each well) or Thermal Blankets (to heat soils downward from the surface). Both forms of the technology were demonstrated on the Mare Island IR11 site.

In each application method, contaminant vapors are drawn through a vacuum collection system and destroyed/treated using a flameless thermal oxidizer with vapor phase activated carbon polishing. The system is automatically controlled and monitored using a programmable logic controller (PLC) and continuous emissions monitoring system (CEM).

The technology is expected to facilitate future treatment of sites impacted by PCBs, pesticides, coal tars, wood treating wastes with PAHs, and other organic contamination. The technology offers on-site destruction of contaminants, and allows for treatment of deep contamination adjacent to, and even under, structures, without the need for excavation.

1.2 Official Department of Defense (DoD) Requirement Statement(s)

Navy Environmental Quality (EQ) R&D Requirement 1.1.4.p, entitled "Improved Remediation of Soils Contaminated with Chlorinated Hydrocarbons and Other Organics", sets forth the following requirements, which are to be addressed through development of innovative technologies:

Many Navy facilities have soils impacted by chlorinated solvents. These soils represent a potential hazard to underlying aquifers and must be remediated prior to any Base Realignment and Closure (BRAC) transfers to the private sector. Solvents cannot be removed safely and

cost-effectively by present state-of-the-art technology (e.g., soil venting). Thus innovative removal/treatment methods are required. Emphasis should be placed on in situ technologies, either biological or chemical. PCBs and pesticides are another significant problem in soils and sediments at Navy and Marine Corps facilities. Also, there are numerous Navy sites with non-chlorinated organics, such as crash/rescue fire fighting training sites where fuel residues mixed with AFFF are impacting soil and groundwater. Remedial technologies most often involve incineration or disposal at Class 1 sites. Incineration is costly and has proven to be extremely controversial with the public. Landfill disposal is also expensive due to scarcity of sites, land ban, and permit restrictions. Innovative, cost efficient technologies must be developed for the Navy to clean up these sites in a timely, safe and cost-effective manner.

1.2.1 How Requirement(s) Were Addressed

The Navy requirement for an innovative, cost efficient technology to replace incineration, landfill disposal, and/or soil venting was addressed through the demonstration of the capabilities of In Situ Thermal Desorption. As described in subsequent sections of this report, ISTD addresses the needs of the Navy in the following ways:

The system does not involve incineration. The flameless thermal oxidation process is fundamentally more efficient and robust than incineration. The system has not been considered to be an incinerator by those issuing air emissions permits where ISTD has been implemented.

ISTD destroys the full range of contaminants described in the Navy requirement, in situ and on site, while generating very little in the way of residues for off-site disposal.

ISTD works effectively and consistently in a wide range of soil types, and has been proven effective in removing organic contaminants from heavy clay soils where soil venting would be ineffective.

ISTD is a safe technology. It protects the workers and the public from exposure of contaminants during removal and destruction.

13 Objectives of the Demonstration

The primary objective of the Field Treatability Demonstration was to evaluate the performance of In Situ Thermal Desorption technology for remediation of soils containing PCBs at the Site.

1.3.1 General Overview

ISTD is among a class of emerging technologies which are now accepted as alternatives to traditional soil excavation for landfill or incineration disposal methods. When used in conjunction with groundwater management techniques, the Thermal Wells can also treat the soil volume into the water saturated zone, which is traditionally beyond the limits of excavating. The general objective of the Thermal Well Demonstration at- the Mare Island facility was to demonstrate the capabilities of the system to treat PCB contaminated soil in an area adjacent to a building, where complete excavation would be impractical. The objectives of the Thermal Blanket Demonstration at the Mare Island facility were to demonstrate the capabilities of the system to treat surficial PCB-contaminated soil to a depth of twelve inches.

13.2 Statement of Specific Demonstration Objectives

The objectives of the Field Treatability Demonstration included the following:

Determination of the level of PCB reduction in site soils achievable by the In Situ Thermal Desorption Technology;

Acquisition of data to evaluate the efficiency of the system and to obtain the cost data as may be applicable for bringing full scale ISTD technology to this and other sites.

The specific objective of the Thermal Well demonstration was to:

Demonstrate that the Thermal Wells can achieve reduction of PCB concentrations to less than 2 mg/kg when the initial PCB concentration is as high as 2200 mg/kg in the soil matrix at the site.

The specific objective of the Thermal Blanket demonstration was to:

Demonstrate that the Thermal Blankets can achieve reduction of PCB concentrations to less than 2 mg/kg at a depth of up to twelve inches.

13.3 Scope and Location of Demonstrations

The field demonstration was conducted adjacent to a former electrical shop within Installation Restoration Site 11 (IR11) at the Mare Island Naval Shipyard. The Thermal Well Demonstration was conducted in situ using a. network of 12 Thermal Wells in the location of a former grease trap, where PCB contamination remained in place after removal of the grease trap.

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The Thermal Blanket Demonstration was conducted in a parking lot area near the Thermal Well Demonstration site, using soils excavated by the Navy during closure of a drain line. This soil was placed in a prepared shallow excavation in order to create a Thermal Blanket demonstration area in close proximity to the selected Thermal Well site.

1.4 Regulatory Issues

Resolution of the problem to be addressed by the ISTD technology - the presence of PCBs and other organic contaminants at Navy sites proposed for redevelopment- involved addressing both regulatory and technical issues, including:

Some or all of the sites are listed on the Comprehensive Environmental Response Compensation and Liability Act (CERCLA or Superfund) list of sites. Remediation activities at these sites are regulated by United States Environmental Protection Agency (US EPA) Region DC. The Mare Island IR11 site is a Federal Superfund site.

Cleanup of sites contaminated with PCBs may also be regulated under the Toxic Substances Control Act (TSCA), with respect to cleanup standards.

Cleanup technologies used to remediate PCBs are also regulated under TSCA from a process operation and permitting standpoint.

For non-CERCLA sites, California EPA (CalEPA) has similar regulatory authority, and CalEPA may also provide oversight and regulatory support, even on Federal lead projects.

The Bay Area Air Quality Management District, as well as CalEPA, regulate discharge of air contaminants. For a project involving thermal desorption and destruction of PCBs, the primary constituents of concern from an air emissions standpoint are PCBs and Hydrogen Chloride (HC1).

For sites which are located in populated areas or are to be redeveloped (the Mare Island site fits both criteria), the future owner, end user, or adjacent residents may participate through the public comment process on EPA actions, or may have other direct review authority. In the case of Mare Island, the City of Vallejo and the Restoration Advisory Board (RAB) are stakeholders in the process and are involved in environmental cleanup decisions.

Pursuant to the Cooperative Demonstration Agreement, no permits are required for on-site operations. However, operations must comply with applicable federal, state, and local

11

regulations for which permits would normally be required. Furthermore, the waiver of the permitting process is not applicable to any off-site operations, including the transport of materials or products to the site or off-site. Any activities which might occur off-site would be subject to the appropriate permitting procedures.

Any off-site disposal of PCS contaminated soils or residues must be conducted in accordance with RCRA and/or TSCA. The ISTD process strictly minimizes waste generation through on-site contaminant destruction.

Equipment to complete the Demonstration was furnished and operated by TerraTherm Environmental Services, Inc. (TerraTherm). TerraTherm is an affiliate of Shell Technology Ventures, Inc. (STVI) and operates the ISTD technology in accordance with the terms of a Draft Nationwide TSCA Operating Permit issued to STVI. The availability of this permit helped to simplify the overall regulatory review process as regulators/officials were able to review the minimum operational limits and monitoring systems which were already approved for use on a nationwide basis by the USEPA. Additional requirements were imposed only where necessary. A PCB stack test was not required on the treatment unit, as a test of the same equipment had recently been completed on another site under the Draft Nationwide TSCA permit.

CalEPA served to coordinate and expedite the regulatory review process. A single Work Plan was reviewed by USEPA Region DC, USEPA Chemical Operations Branch, CalEPA, BADCAT, the Navy, and die Bay Area Air Quality Management District (BAAQMD). In addition, an air permit application was separately submitted to BAAQMD for equivalency review.

1.5 Previous Testing of the Technology

This section presents the current development status of ISTD technology, and the technology is described in terms of demonstration history, previous acceptance and successful applications.

Bench and field-scale pilot tests and a field demonstration of the Thermal Blanket system were conducted at the former South Glens Falls, New York, Drag Strip Superfund Site. PCBs at concentrations up to 5,000 mg/kg (average of 500 mg/kg) were successfully remediated in soil at depths of up to 18 inches. The largest of the Glens Falls pilot tests used five adjacent Thermal Blankets heating soil, with a second group of five cooling from the prior test. The Glens Falls demonstration was conducted under a TSCA Research and Development (R&D) permit and an operating permit application including a Demonstration Test Plan. Subsequent to the successful demonstration, the draft TSCA National Permit was issued for the treatment system. The results of the Glens Falls demonstration were documented in a paper entitled "Field Demonstration of a Full-Scale In-Situ Thermal Desorption System for Remediation of Soil Containing PCBs and

12

other Hydrocarbons," Richard B. Sheldon, et. al, published in the proceedings of HazWaste World Expo, Washington, D.C., September, 1996.

The Thermal Wells have been successfully demonstrated at a TerraTherm research facility on surrogate compounds, which display physical properties similar to PCBs, but are not toxic. The Thermal Wells have also been successfully demonstrated on PCB containing soils at a former transformer refurbishing Superfund site in Missouri. At that "site, soils with PCB contamination at concentrations up to 20,000 mg/kg and depths up to 10 feet were successfully treated to concentrations of less than 2 mg/kg. Most post-treatment samples had non-detect PCB concentrations at a detection limit of 0.033 mg/kg. Stack test results from the Missouri site were submitted to USEPA, CalEPA, and BAAQMD during the review process for the Mare Island ISTD Demonstration Work Plan. These test results demonstrate a destruction/removal efficiency (DRE) of greater than 99.9999 percent.

The ISTD technology has effectively removed PCBs from soil to concentrations below 2 mg/kg. PCB destruction efficiencies of at least 99.9999% were achieved in the thermal treatment system.

2.0 Technology Description

2.1 Description

This section describes in detail the ISTD technology introduced in Section 1.0. The description includes a presentation of the principles, applicability, advantages, and status of the technology.

2.1.1 Principles of Technology

In Situ Thermal Desorption combines thermal desorption and vacuum extraction to remove organic compounds from soils in situ. A Thermal Well assembly was used to treat contaminated soils at depth. A Thermal Blanket desorption unit was applied directly to the surface to treat shallow contaminated soils. Thermal Wells and Thermal Blankets were both deployed at the Mare Island facility in consecutive demonstrations.

The Thermal Well assembly consists of five components: (1) stainless steel well casing, (2) a subsurface heating element, (3) a vacuum barrier of shimstock, (4) a layer of insulating material, and (5) an impermeable sheet. The heaters initiate a thermal front which moves laterally through the soil by thermal diffusion. As the soil is heated, organic compounds and water vapor are desorbed and evaporated from the soil matrix. Negative pressure is induced throughout the

13

treatment zone, and the impermeable liner and insulation minimize surface air inward leakage and heat loss. This creates a negative pressure in the impacted soil, removing gases from the treatment zone. The vapors are drawn via the vacuum blower. Drawn vapors are treated by the system within a flameless thermal oxidizer, followed by carbon polishing vessels to ensure that stack gases comply with air emission requirements.

The system used during this demonstration was comprised of an electrical oxidation unit, followed by a heat exchanger to reduce the vapor temperature, and a final polishing by granular activated carbon vessels. A combination carbon and HC1 reduction media were used in the first vessel to aid in reduction of HC1. A schematic of the Thermal Well system is shown in Figure 21.

The Thermal Blanket system used the same vapor extraction and vapor treatment systems. However, heat was supplied from the surface, using a Thermal Blanket assembly. The principal components of each Thermal Blanket were: (1) a surface heating element, (2) an insulating mat, and (3) an impermeable sheet. See Figure 2-2.

2.1.2 Waste and Media Applicability

The ISTD technology is applicable to soil contaminated with organic compounds including high boiling point compounds such as PCBs, or low boiling point metals. The Thermal Wells may also be used to treat source areas of groundwater contamination, sludge, and areas with non-aqueous phased liquids (NAPL), in conjunction with technologies such as dewatering, if required, based on site conditions. The physical processes of ISTD technology can be used to treat almost all classes of organic compounds; however, ISTD is more cost-competitive on high boiling point compounds, which are more difficult and costly to remove by conventional methods.

Solvents and PCBs were used throughout industry, especially in the electronics industries and in large electrical equipment, such as transformers, circuit breakers, and electric rail cars. Soil with these contaminants can be found at many large industrial sites, electrical utilities, and at many railyard facilities.

Because the technology is modular and very flexible in application, ISTD can be used for a wide range of contaminants and site conditions. The ISTD technology is applicable at many sites which have organic contamination in soil media. As is the case with almost any technology, site specific conditions must be well understood in order to successfully remediate non-soil media including non-aqueous phase liquids (NAPL), sludges, high viscosity oil products or others. In such cases, the remedial system design would take into account potential settlement, potential combustion of waste materials, and increased organic loading to the system. Design modifications may include

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specific designs of header piping and well systems to allow for settlement, or other modifications as may be needed for proper remedial operations.

The Thermal Well technology was originally developed for the purpose of enhanced recovery of crude oil from California shales, and recovery of NAPLs in either soil or bedrock is seen as one of the most beneficial and promising applications of the technology. Recovery of viscous materials buried in pits can also be accomplished.

During the early technology development tests at the Drag Strip Site in South Glens Falls, New York, tests were performed to determine if underground fires were of concern. A test plot was prepared by adding a large quantity of organic matter (branches, roots, leaves, & etc.) to the soil. The areas outside the blanket area were monitored for indications of fires, and the air pollution control equipment was monitored to see if there were any adverse effects of the heavy organic loading on the system. The results of these tests showed that subsurface fires were not of concern due to several factors including: 1) the thermal influence of the blanket system was limited to the area directly under the Thermal Blanket and declined very quickly beyond the edge of the blanket; and, 2) the conditions in the soil do not support combustion (i.e. sand and gravel act as a flame arrester) preventing the spread of fire or flame through the soil. Based on these tests and experience with the Thermal Wells ;at other demonstration test sites, subsurface fires are not of concern in treatment of soil media.

During application of the ISTD technologies, the extent of the thermal front outside of the targeted treatment area is limited and uniform. The extent of soil heating has been measured to extend approximately 6-12 inches below the treatment zone of a Thermal Blanket, and approximately 1-2 feet surrounding the outer perimeter of a group of Thermal Wells. The ISTD technology can be used within these limits near underground utilities. Where utilities are present, thermocouples are placed in the soil adjacent to the utility to confirm the actual temperature and regulate heating as required. In the case of a buried utility which is less temperature sensitive (such as a concrete sewer pipe) and the soils are impacted by a lower boiling contaminant, it is possible to safely treat the adjacent area around the utility. In the Thermal Well demonstration area at Mare Island, there were several existing underground utilities near the well pattern, and more important, a nearby building foundation. These were not affected during the Demonstration, as the thermal front extended less than five feet beyond the well pattern.

2.2 Strengths, Advantages, and Weaknesses

The system has distinct advantages over currently available and comparable technologies, including:

17

highly mobile equipment for in situ treatment. relatively short treatment time; 30-60 days vs. years of pump and treat or extended periods of

conventional soil vapor extraction (for volatile organics in clay soils). in situ treatment reduces owner liability at offsite landfills or treatment facilities. can be used in areas where traditional excavation and removal are not possible. proven organic chemical removal to below regulatory limits completely enclosed system eliminates emissions of VOCs or intermediates to the atmosphere. can be used near underground utilities and building foundations, and under buildings. is not limited by the maximum concentration of contaminant or consistency of media to be

treated. removes contaminants from clay soils where soil permeability, partitioning coefficients, and other

physical factors are problematic for other technologies.

The Thermal Wells are effective to any depth achievable by standard drilling techniques, both vertical and horizontal.

23 Factors Influencing Cost and Performance

The factors which are important in establishing the cost and performance for an ISTD project are unique when compared with other technologies. Ultimately, the most important success factors are the length of the treatment cycle and the volume of soU treated per cycle. Most site-specific conditions ultimately translate into a change in the length of the heating cycle.

The following parameters influence or potentially influence treatment cycle time:

Contaminants of concern - Each contaminant of concern has a unique boiling point. Contaminant desorption occurs at temperatures below the boiling point, but desorption occurs at a much more rapid rate when the boiling point is reached. Therefore, the target treatment temperature is generally at the boiling point of the highest boiling contaminant on site. A higher boiling point translates into a higher target temperature, and therefore a longer treatment cycle.

Moisture Content - Higher moisture content requires a longer treatment time to remove groundwater. It is very important to eliminate sources of recharge of groundwater. Initial natural moisture content is helpful, as boiling off one pore volume of water often benefits steam stripping of contaminants from soils.

Contaminant concentration - Contaminant concentration has minimal effect on treatment cycle time over the wide range of contaminant concentrations typically found in contaminated media. Only at sites with a very high organic content (greater than several percent of PCBs, oil, or other organics) is a slower heating rate or larger treatment vapor system required.

Depth of Contaminated Zone - For a given volume, a deeper contaminated zone over a smaller

18

area requires fewer (deeper) wells, but has an insignificant effect on cycle time. Soil Type - Soil (or rock) type has little overall effect on treatment time. Thermal conductivity

values for all types of soil and rock fall in a very narrow range (approximately a factor of two).

TerraTherm has developeda thermal model which is used to estimate the required heating time and temperature for each site, based on factors listed above, as well as other factors. This estimate of heating time is important in estimating the cost of specific projects.

Several parameters were monitored during the demonstrations. Due to the energy consumption rate during the heating phase of the treatment process, the time required to reach the targeted treatment temperature affects the cost of treatment Accordingly, the parameters that were monitored included energy consumption rates for the hearing equipment and thermal oxidizer, and the effect of soil moisture content on the treatment time (compared to that in the thermal model and that experienced at other sites). The specific properties of the soil (including soil classification and moisture content) were documented to help predict well spacing and treatment times at other sites with similar conditions.

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The ISTD technology is modular in construction, and process trailers have already been constructed in a number of sizes. Units constructed to date or planned include the MU-125 (Mobile Unit-125 cfin) used at the Mare Island demonstration, as well as the MU-1000, MU-1800, MU-3000, and MU-5000 (each model number designates the vapor flow rate of the treatment unit).

As the cost of the system operators (as well as portions of the capital cost such as the PLC control and CEM systems) does not vary from one unit to the next, larger units will typically have lower overall costs per volume of soil treated when utilized on appropriately sized treatment areas.

Additional system and operational parameters, as well as matrix characteristics which may affect ISTD treatment cost or performance are summarized on Table 2-1. Suggested parameters applicable to specific technology types are provided in Table 4-1 of Reference 2. Because ISTD is an innovative technology which does not fall within any of the typical categories of remedial systems, the factors in Table 2-1 are a hybrid of factors typically used for evaluation of remedial technologies including ex situ thermal desorption, in-situ steam extraction, and soil vapor extraction.

19

Table 2-1

Summary of Cost and Performance Factors

Factors Affecting Cost and Performance Typical or Measured Value

MATRIX CHARACTERISTICS SOIL TYPES

Soil Classification Clay Content/Particle Size Distribution

AGGREGATE SOIL PROPERTIES Moisture Content Air Permeability Porosity

ORGANICS IN SOIL Total organic Carbon Oil & Grease or Total petroleum Hydrocarbons Nonaqueous Phase Liquids

MISCELLANEOUS Contaminant Sorption

BTU Value Halogen Content Presence of Metals

Thermal Conductivity

Silt With Sand 82% passes #200 sieve

Not Determined Not Determined Not Determined

Not Determined Not Determined Not Determined

PCB Aroclor 1254 has a Koc of 810,000; Aroclor 1260 has a Koc of 1,800,000 Not Determined 3.3 E-3 % (calculated based on PCB Content) Background levels for RCRA metals

Not Measured - Typically between 1 and 5 cal/m/hr/C for all soil types

OPERATING PARAMETERS SYSTEM PARAMETERS

Air Flow Rate 125 scfm for Thermal Well Demonstration (Typically 1 scfin per foot of well)

60 scfin for Thermal Blanket Demonstration (Typically 1.5-2 scfin per square foot)

Operating Vacuum Typically 5 inches w.c. in collection header, minimum 0.1" w.c. measured in soil.

Flameless Thermal Oxidizer Residence Time 30-60 seconds Flamclcss Thermal Oxidizer Bed Temperature Typically 1600F to 1800 F Treatment Cycle Duration 30 to 45 days for Thermal Wells (37 days at Mare

Island)1/! to 8 days for Thermal Blankets (7 days at Mare Island)

Heater Temperature Typically 1400F-1600 F Target Soil Temperature Boiling Point of Contaminant to be Treated

(600 F for PCB Aroclor 1254 and 1260 at Mare island)

3.0 Site/Facility Description

3.1 Background

After screening a number of potential Navy sites in the Bay Area, Mare Island IR-11 was selected as the demonstration site based on the following criteria:

The site had high concentrations of PCBs identified in the investigation report. PCBs are persistent, have a high boiling point, are difficult to remove by other methods, and are strictly regulated.

The site had deep contamination (up to 14 feet below surface grade) adjacent to a massive structure. This is a difficult location to implement other technologies. For example, excavation could require expensive shoring of the excavation to work close to a building.

Contamination was originally expected to extend a few feet into the groundwater table, which would allow for demonstration of dewatering. Additional information obtained during predemonstration testing indicated that the test area was entirely unsaturated.

Each of the above criteria made the selected test area more complex, pointing out ways in which site conditions which pose potential limitations for other technologies could be overcome using ISTD.

The demonstration site was located adjacent to the western comer of the former Mare Island Electrical shop (Building 866). The area was paved, and contained PCB-contaminated soils in a previously disturbed excavation area to a depth of approximately 14 feet

3.2 Site/Facility Characteristics

The following sections provide information regarding the site, including the current understanding of site geology, hydrogeology, and contaminant distribution near the former grease trap at the electrical shop.

3.2.1 Site Location and History

The Mare Island electrical shop is located between Cedar and Suisun Avenues and 11th and 12th

Streets, near the center of Mare Island (Figure 3-1). The test site was located in the area of the

21

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former 3,000 gallon grease trap and adjacent paved areas located at the northwest corner of Building 866 (Figure 3-2). The facility is on a relatively flat portion of a hillside with a surface elevation approximately 26 feet above mean sea level. To the north and west of the facility, a hill slopes sharply upward to the original grade of the hill side. The grounds and building are surrounded by an eight-foot high chain link fence. The southwest half of the facility is located on bedrock, while approximately three to four feet of fill overlies the bedrock in the northeastern portion of the property.

Building 866 is a five story concrete block structure built on a concrete slab at grade (no basement). The area of the former grease trap, which was connected to the industrial wastewater (IW) collection system, is now paved. A former transformer storage area is near the northwest side of the building. Underground utilities in the area of the site include storm water and sanitary sewer pipelines, dredge and saltwater pipelines, and a former fuel oil pipeline.

From 1864 through the mid 1940s, the land occupied by the facility was used as a U.S. Marine parade ground. By 1946 the parade ground had been converted into a baseball field with grandstands. By 1955 the grandstands, most of the barracks, and the surrounding area had been dismantled, and construction of Building 866 had begun.

The facility was used as an electrical workshop from 1955 until 1994. Activities in the building included electrical and electronic equipment processing and overhaul. Processing entailed fabricating circuit boards, switches, breakers, transducers, and plugs. Overhaul activities included cleaning, repairing, and decommissioning motors, generators, transducers, transformers, breakers, and electrical instruments. Materials used during the processing and overhaul activities included lubricants, sealants, paints, plating compounds, epoxies, rubber compounds, radioactive materials (including plutonium and cesium), oils, photochemicals, solvents, degreasers, and detergents. Solvents (including methyl ethyl ketone, and stoddard solvent) were frequently used in most of the facility work areas from 1955 until the late 1960s.

The largest equipment cleaning facility, the cleaning room associated with the motor and transformer work area, was built so that workers could easily wash motors and transformers before repairing them or decommissioning the equipment The cleaning room and the motor and transformer work areas are located on the ground floor in the western corner of the building. Transformers were reportedly stored in the fenced area outside the cleaning room.

From 1955 to 1978, transformers washed in the cleaning room contained PCB oils. Transformer washing procedures included draining the oil and pressure washing the interior of the transformers with steam and degreasing solvents or detergents. All of the oil and washing wastes entered a 30gallon sump through floor grates and drains. The liquid waste and sludge that accumulated in the

23

I t I THtRUAL 1LAHKCT THUTMCMT AKtA (i-2)

QJCCON WATCHTomot r~ ii

UJ3 UJ >

2 3 ( )

MESA ROAD

BUILDING 866

IMVT ii wni liYnirr

\ 1-*-

xjTti UK uummt ion raw nouc 7-< mi-wUMe M iwu eautrroi uxAioa. moui. wucmwnM. HUC BUM HUM. im IT MC

RT ENVIRONMENTAL SERVICES. INC.

21S Wmt Church Rood tng of Pruitlo. PA 19406

TERRATHERM ENVIRONMENTAL SERVICES WC.

SITE PLAN MARE ISLAND. CALIFORNIA

a mix 13iL

cleaning room sump were pumped through a 6-inch diameter drain pipeline into the grease trap near the western corner of the building. The grease trap separated grease and sludge from the liquid waste prior to discharge into the storm water or sanitary sewer (1955 to 1972), or to the IW collection (after its construction in 1972). Grease and sludge from the grease trap were removed periodically.

In 1981, the Navy cleaned and plugged the floor drains in the cleaning room. The sludge was found to contain PCBs, and further samples revealed PCB contamination in the cleaning room sump, the grease trap, and the IW collection system. As a result, these systems were cleaned and removed from service. The grease trap was subsequently removed, and the lines of the IW collection system were capped.

During the drilling of a dewatering test well for a planned pump test prior to beginning the ISTD Demonstration, a pipeline containing oily liquid was encountered. This pipeline is believed to be a portion of the drain system previously connecting Building 866 to the grease trap. This line was pumped out, cut and capped at the building wall prior to proceeding. Soils excavated from this area were used for the Thermal Blanket demonstration.

Oily liquids containing some of the compounds used in the cleaning room apparently entered the soil through the grease trap. As previously stated, the area for the ISTD demonstration is located in the vicinity of the former grease trap near the western corner of the building as shown in Figure 3-2. The target compounds in this area are primarily PCBs, although total petroleum hydrocarbons (TPH) in the gasoline range were also detected in concentrations above applicable standards. Table 3-1 (reproduced from Table 7-5 in the RI - Reference 4) lists the principal target compounds, concentration ranges, and Preliminary Remediation Goals (PRGs). Concentration reduction of PCBs was the focus of the technology demonstration.

32.2 Geology

Prior to the demonstration activities, forty-nine soil borings had been drilled and logged at the Mare Island electrical shop during the Remedial Investigation (RI) study. Borehole depths ranged from 8 feet to 34 feet below ground surface (bgs). Three geologic units were identified in the region of the test site. These included, from top to bottom stratigraphically, (1) artificial fill material, (2) silt clay, and (3) weathered bedrock.

Based on lithologies of the geologic materials and the depth to groundwater, siltstone/fine-grained sandstone bedrock was the only hydrogeologic unit identified at the Mare Island electrical shop. The overlying artificial fill and clay units do not come in contact with groundwater.

25

Table 3-1

ERll STATISTICAL SUMMARY OF SOIL ANALYSES PHASE I AND H REMEDIAL INVESTIGATION

MARE ISLAND, CALIFORNIA

Nuabr of }f--in Anra?* of Kvmbvc of Sj^,l Kith

IMatMT of Dtctd De*cc*4 Supl Mith Cooc. CraaCar Aoaly-t &KA

KA KA z

SBCXVOULXXU osfiuxc COKTOOXDI PEEKOL TOTAL SVOCS

1/11 I/I*

2 2

0.( 0.(

0 HP

KA KE

riSTXCXDXS/PCB*

4.4'-DOE AROCLOR-12S4 AROCLOR-12(0

1/34 3/45

11/151

0.2 100

2,200

0.2 35

270

0 3 1

KA KA KA

01/09/97 T-7-21

Huabr of Oiicrc Loc. Hi til S&mpl* ?RC J^bicac

Cone. Crer Vlu Value T}un na n4 (g/kj) C*J/Tc>

tebiant'

0 0

77,000 31

26.000 1.3

8 0.3S IS

0 5,300 KA 2 0.14 1.1 3 t 3.5

ME HP KA

0 0

77.000 0.2

5( KA

0 0

4. (00 2,100

KA 213

HE HP KA 2 130 33

KE HP KA 0 3,200 5(0

0 23 XA 0 310 KA 0 ISO 70

KE HP XA

0 110 KA 0 310 KA

HE HP KA 0 5.4 KA

0 4(,000 KA KE HP HA

0 54 0 130 0 23.000 100

0 75 KA 0 1.4 XA 0 2.JOO KA 0 7 XA

0 1,900 XA 0 7 KA 0 910 KA

HE HP KA

0 39,000 KA KE HP XA

0 1 KA 3 0.07 XA 4 0.07 XA

Table 3-1 (continued) IRll STATISTICAL SUMMARY OF SOIL ANALYSES

PHASE I AND O REMEDIAL INVESTIGATION MARE ISLAND, CALIFORNIA

Kuaber of ffumbex of WJ--H .~ Awra^e of Number of Sample* With. Dicrt Loc.

Number of Detected Detected Savples Hith Cone. Greater Kith Sample tsa ^vhienc Analyta Section/ Coac. Coac. Coac. Creacer Than FRC and Cone. Greater Value Value

Analy***' (7/kg) (sg/ko;) Than FRC Ambicae Than ttta and (mqfky) (ag/lcg) Ambient'

jKsnairs/pcs.

HEPTACHLOR 2/34 0.002 0.0009 0 NA 0 0.1 KA TOTAL PCBS 14/158 2.200 220 11 NA 7 | 0.07 | KA

FKTXjQLX BC L** T yiTQy^

DIESEL RANGE 4/1(1 1.100 3.100 NP HE HE HP KA GASOLINE RANGE K/KJ 12,000 1,300 HP HE HE HP KA MOTOR OIL RANGE 4/1(1 320 140 HP HE HE HP KA TRPH 3/23 47 20 NP HE HE HP KA

XXSCZLLAICBOOS TOTAL ORGANIC CARBON 2/7 54,000 45.000 NP HE HE HP KA

Koccs:

1. Tocl numtxr o< aapl

3.2.3 Hydrogeology

Groundwater in the uppermost aquifer beneath building 866 is encountered approximately 9 feet to 15 feet bgs; groundwater elevations ranged between 10.5 to 17.69 feet above mean sea level. The direction of flow in the shallow water-bearing zone at the Mare Island electrical shop is to the east toward Mare Island Strait. Most of the underground utility pipelines were above the groundwater table. Neither these utility pipelines nor the backfill materials-are expected to affect groundwater flow at the site. The 48-inch diameter storm water pipeline that runs southwest to northeast under Building 866 and below the former grease trap treatment area is below the water table (approximately 20 feet bgs) and may act as a preferential flow pathway. This pipeline was installed in a tunnel under the site. Data are not available on the influence of this utility pipeline on shallow groundwater flow; the influence may not be significant if the static groundwater level at the site is within relatively impervious bedrock. It is possible that the tunnel or possible leakage into the pipeline, may act as a preferential groundwater pathway altering flow in the vicinity of the pipeline.

The geologic cross sections for the Mare Island electrical shop provided in the RI indicate that the wells are screened in a mostly homogeneous weathered bedrock unit, which consists primarily of weathered siltstone and fine-grained sandstone. A site-specific value for the hydraulic conductivity of the siltstone/fine-grained sandstone is not available. A slug test performed in June 1997 on an existing well near the demonstration area indicated a preliminary conductivity value of IxlO"5

cm/sec. A pump test scheduled to be conducted within the actual demonstration area was canceled after two wells drilled in the demonstration area to a depth of 16 feet were dry.

3.2.4 Contaminant Distribution

The target compounds at the Mare Island electrical shop are listed in Table 3-1. These compounds were identified during site investigation by surface soil sampling, concrete core sampling, hand augered boring sampling, vacuum excavation sampling, GEOPROBE survey, and well monitoring. The range of concentrations detected for each compound identified is also shown in Table 3-1.

Organic compounds detected in soil at the Mare Island electrical shop included PCBs, volatile organic compounds (VOCs), phenol, TPH, and pesticides. Fifteen percent of the soil samples collected at the site were analyzed for Contract Laboratory Program (CLP) VOCs, semi-volatile organic compounds (SVOCs), and pesticides; the distribution of samples analyzed for these constituents was sufficient to evaluate the presence of contaminants at the site. Of the organic compounds detected, only PCBs were detected in concentrations exceeding soil standards. There are currently no established remedial standards for TPH. The frequency of detection and distribution of PCBs and TPH in soil are discussed below. Although VOCs, phenol, and pesticides were detected at concentrations below their respective remedial standards, a brief description of the

28

frequency of detection and distribution of these compounds is also included because these compounds were typically found in the same areas as PCBs and TPH.

The sources of these organic compounds are likely the same sources presented in the PCB and TPH sections: transformer, motor, and generator storage coupled with subsequent leakage or spillage; possible transport along utility corridors from more highly contaminated areas; or possible leakage of contaminants from utility pipelines into soil.

Four metals (arsenic, beryllium, cadmium, and lead) were detected in samples at the site. Metals in soil at the Mare Island electrical shop most likely have the same sources as the organic constituents. The probable cause of metals hi the area around the grease trap excavation is former cleaning activities associated with transformers, motors, and generators. The distribution of metals in this area and the presence of organic compounds in soil samples with high metals concentrations, indicate that electrical equipment oils, gasoline, diesel, and/or waste liquids containing metals were likely released into the soil through leakage from the former grease trap. In the transformer storage area, metals in surface soils are likely associated with transformer, motor, and generator storage. Before equipment was cleaned and repaired or decommissioned, it was transported and stored hi the immediate vicinity of the exposed surface soil. Oil, gasoline, and/or diesel containing metals may have leaked or been spilled from the equipment as it was transported from the parking area or during storage near the surface soil.

During sampling of groundwater monitoring wells at the Mare Island electrical shop, tetrachloroethene, trichloroethene, TPH-gr (gasoline range), TPH-dr/mr (diesel range), and organotins were detected in groundwater from one or more of the wells at the site. A groundwater sample collected from Monitoring Wells 11W01 and 11W03 contained low concentrations of tetrachloroethene and trichloroethene; a sample from Monitoring Well 11W02 contained TPH-gr; and a sample from Monitoring Well 11W03 also contained organotins and TPH-dr/mr. Metals were not detected in groundwater samples from monitoring wells near the former grease trap.

Groundwater samples collected from locations near the grease trap excavation (Monitoring Well 11W01 and GEOPROBE Boring 11GB008) contained low concentrations of chlorinated solvents (up to 6 micrograms per liter (ug/L)) and TPH (up to 300 milligrams per liter (mg/L)). The organic compounds d