P.O. BOX 3567

DAVENPORT, BOWA 52808

(319) 359-2000

APR 2 4ALCOA

April 23, 1996

James ColbertEPA Region VIIIowa-Nebraska Remedial Branch726 Minnesota Ave.Kansas City, Kansas 66101

RE: CERCLA Order VII-95-F-0026: Unit CMW-08-Fuel Oil Pump House

Dear Jim:

Confirming our earlier phone conversations on this subject, this letter is a request forapproval to proceed with excavation and disposal of PCB-contaminated soils andconcrete foundation materials from the referenced unit location. The enclosed"Specification for Building 876 Soil and Foundation Removal and Disposal"(Specification), dated April 20, 1996, describes the intended work and is being sent outfor quotes this week. Approval will be requested for the potential remediationcontractor once the bids have been received and reviewed. We anticipate this will beeither Chemical Waste Management or Heritage, both reputable remediationcompanies.

As we have discussed, this unit is the location of a fuel oil pump house that washistorically used to pump PCB-contaminated oils into storage tanks and subsequentlyto an ingot furnace for disposal. The tanks, equipment, piping and building structurewere decontaminated under a TCSA Consent Order and were removed in late 1995.The building floor and foundations were left in place to be addressed as part ofremedial activities for this unit. This area was listed as a unit under the captionedCERCLA Consent Order because earlier investigations confirmed the presence ofPCB-contaminated soils beneath the building floor. The unit was assigned a priority of28 by the prioritization procedure submitted to you on October 11, 1995, and our planswere to address it under the approved risk-based procedure, probably in 1997.

The reason we feel it is necessary to proceed with early excavation in this area is theintermittent presence of free liquid and stained soils at the surface. With the warmerweather, water and small amounts of oil trapped beneath the building floor are beingforced to the surface. The liquids are being contained and routinely removed by plantforces for disposal as a TSCA waste. However, we feel it would be prudent to attemptto remove the major source of this material through excavation and disposal asdescribed in the enclosed specification. Work will proceed based on inspection of thearea being excavated and excavation will be terminated based on a visual lack of

37759

Superfund

James ColbertApril 23, 1996Page 2 of 2

stained material. Before the excavation is filled with clean borrow, random samples willbe taken from the bottom of the excavation for PCB analysis. These data will then becombined with existing data from the area for use in the preparation of an RBC Report.Further action at this unit will be based on the RBC Report and subsequent UnitRecommendation Memo.

In summary, we are requesting approval to proceed with excavation and disposal ofPCB-contaminated soils and foundation materials at the location of the Fuel Oil PumpHouse. Once the visually contaminated soils and concrete are removed, theexcavation will be sampled and backfilled with clean fill. Any subsequent work at thisunit will be done according to the original procedure for a priority 28 unit - RBCReport, Unit Recommendation Memo, EE\CA if required, etc. Future work will bedictated solely by results of the RBC Report and Unit Recommendation Memo. It is notour intention to use this excavation action as a reason not to proceed with additionalwork if the RBC Report indicates that a risk remains.

If you have any questions, please feel free to call me or Bud Sturtzer of my staff. Bud'stelephone number is (319) 344-1628.

Yours truly,

Marshall SonksenRemediation Manager

cc: Bud Sturtzer w\o encl. ( via e-mail)

ALUMINUM COMPANY OF AMERICA

DAVENPORT WORKS

RIVERDALE, IOWA

SPECIFICATION FORBUILDING 876 SOIL AND FOUNDATION

REMOVAL AND DISPOSALApril 20,1996

SHOP ORDER NO. 207026

TABLE OF CONTENTS

SECTION

I. SITE BACKGROUND

II. SCOPE OF WORK

III. BASIS OF PAYMENT

IV. CONSTRUCTION SCHEDULE

V. SITE CONDITIONS

I. Site Background

Historically, Building 876 served as the pumping station for oil transfer between the FormerWaste Oil Lagoon (Unit HU-09) and later, the PORI building, three one-million gallon above groundstorage tanks and the Ingot Plant from the early 1970's until its removal in to 1994. Historically,reclaimed oil from the Former Waste Oil Lagoon and the Industrial Waste Treatment Facility (UnitCWM-10) contained PCBs . Later, non-contaminated oil was pumped from the PORI Building to one ofthe one-million gallon tanks. When fuel oil was required in the Ingot Plant, equipment in building 876was used to pump the reclaimed oil stored the tanks to the No. 13 or No. 14 melting furnaces (Unit IPO-05) located in the Ingot Plant. In addition, the Building 876 pump house was used to transfer neat oiland scrap oil into and out of the 8,000 and 20,000 and 29,000 gallon above ground tanks located on thenorth side of Building 876. The area consisted of the pump house, the three smaller above groundstorage tanks and associated piping and transfer lines to and from the PORI building, the three one-million gallon above ground storage tanks, the smaller tanks and the Ingot Plant furnaces. The threemillion gallon tanks, all associated piping (including that to the Ingot Plant furnaces), equipment and thephysical Building 876 was decontaminated under a TSCA Consent Order. Subsequent to thedecontamination, Building 876 was demolished in November 1995 and only the building foundationremains along with some of the underground piping. The pipes were previously decontaminated,however, during periods of high groundwater flow, water carrying PCB containing oil and soil may haveflowed into sections of pipe where they had been cut off from above ground piping. Decontamination ofthese pipes will be done as part of this removal action.

Previous investigations have indicated polychlorinated biphenyl (PCBs) and total petroleumhydrocarbons (TPH) in soil beneath and surrounding the building. During the early spring and periods ofheavy rain, oil seeps have been observed in soil surrounding the foundation of building 876. This isprobably due to high groundwater flows forcing the oil through the seeps. In 1990, seven hollow stemauger borings were drilled to depths ranging from 10.5 feet to 13 feet around the perimeter of the buildingand four hand auger borings were completed to depths of 2.0 to 6.0 feet adjacent to and beneath building876. The borings were taken to obtain information regarding the lithology, thickness, moisture contentand quality of the unconsolidated soils near building 876.

The unconsolidated soils encountered while drilling around the perimeter of the building consistprimarily of two distinct horizons, the lower-most of the two units is comprised of silts with varyingamounts of sand and clay. The upper few feet of the unconsolidated soil tends to be a mixture of organicrich clays and compacted construction fill (clay and crushed limestone). The thickness of theunconsolidated soil near Building 876 ranges from 9 to 12.5 feet.

Results of laboratory analyses of soil samples collected during the field program reveal thepresence of PCBs and Oil and Grease in soils beneath Building 876. Visual observation of the soilsamples during drilling also indicated the presence of free-product oils beneath the building. PCBs weredetected in four of the 23 soil samples collected from the eleven borings. PCB concentrations rangedfrom 2 mg/kg to 88 mg/kg.

CERCLA Consent Order

Building 876 (CWM-08) is mandated by Comprehensive Environmental Response,Compensation and Liability Act (CERCLA) Consent Order Dockets No. 90-F-0027. Because of theintermittent seepage of PCB containing oil to the ground surface in the area of Building 876, a Time-Critical Removal Action of the foundations, contaminated soil and it's source is proposed for thismanagement unit under the above referenced Order . Upon approval of this scope of work by the EPAwork to remediate this area will commence.

The purpose of this time-critical removal action is to remove the source of PCB oils that aremigrating to the surface with upward groundwater movement. Subsequent to removal of the visuallycontaminated materials, soil samples will be collected before the excavation is backfilled. These data willthen be used in preparation of an RBC Report for the Unit. Subsequent management of the unit will beper the risk-based procedures detailed in CERCLA Consent Order Dockets No. 90-F-0027.

EL SCOPE OF WORK

This contractor shall furnish all materials, equipment, labor, supervision, tools, laboratoryservices, construction plant, loading, unloading, hauling, taxes, insurance, permits, disposal of residueand all other things (unless otherwise noted) necessary to complete the removal and disposal of theremaining Building 876 (Pump house) foundation and PCB and total petroleum hydrocarbon (TPH)containing soils within the immediate vicinity of the former building located at the Owner's DavenportWorks, Riverdale, Iowa. All excavated material, collected groundwater, equipment or pipingdecontamination rinseate, and residual material such as protective clothing that may have beencontaminated during site operations shall be disposed of in a TSCA permitted landfill or incinerator, asappropriate. Hauling and disposal of materials shall be part of this contract, but hauling and disposalsubcontractors for each shall come from the attached list of Alcoa-approved sources, shall be specifiedin the bid document.

The total volume of material to be excavated from the former building 876 area is estimated torange from approximately 700 to 1500 cubic yards. Based on prior soil borings and chemical analyses,the impacted area is approximately 40 ft x 40 ft x 12 ft. Visual inspections of the excavated area will beconducted during excavation. The excavation will be terminated after a visual inspection by the AlcoaEngineer has determined that no oil stained soils remain in the area. Following sampling of the excavatedare(see Post Excavation Environmental Sampling below) and approval by Alcoa's engineer to proceed,the excavated area shall be backfilled to grad with common borrow and covered with 6"-8" of gravel.Borrow material shall be provided by this contractor. Gravel cover will be provided by Alcoa from an on-site location. Transportation and spreading of the gravel shall be by this contractor.

Several sections of buried pipes that have been removed from service have been identified in thearea . These are to be confirmed during the site visit. These pipes are to be triple rinsed to decontaminatethem according to TSCA regulations. All rinseate is to be removed from the pipes and the pipes thenfilled with flowable mortar or similar material.

If the source of the oil seep(s) is not removed, additional excavation may be necessary. If thesource is leaking underground pipe, the pipe shall be removed or cleaned and filled with inert material.(DETERMINED IN THE FIELD - but far enough away that train traffic would not be disturbed)

The contractor shall submit a site specific Work Plan, associated contingency plans and Healthand Safety Plan to Alcoa at least thirty days before field work is scheduled to begin. All materials shippedoff- site for disposal shall be shipped under manifest. Each load shall be inspected by Alcoa's engineerbefore shipment and the manifest shall be signed by the Alcoa Engineer.

Post Excavation Environmental Sampling

After the excavation has been visually determined to be complete, the Contractor shall survey agrid using the Davenport Works coordinate system over the excavated area. The grid spacing shall be tenfoot x ten foot increments (100 sq. Ft.). Twenty-five surface soil samples will be taken from each 100square foot grid section and composited into one sample per grid. Each sample will be sent to a certifiedlaboratory for PCB analysis. For example, if the excavated area were to be 40 ft x 40 ft., sixteencomposite samples would be gathered and sent to the certified laboratory.

BASIS OF PAYMENT

The contractor shall be liable for and shall pay all Iowa Sales and Use Taxes on all Contractor-furnished materials, machinery, tools, equipment, supplies and similar items which are used whether ornot incorporated into the project.

The invoice for the removal of the PCB containing soil work will not be paid until the completionof the Removal Action.

The Contractor shall supply safety information requested in the Alcoa Engineering Standard33.052.3, Prequalification Questionnaire.

The Contractor shall submit the following breakdown as a basis of bid:

1. Soil Excavation $ per cubic yard

2. Transportation and $ per truck load.

3. Disposal $ per unit (gal or ton)

4. Pipe Decontamination L. S. $

3. Pipe Removal and Additional Trench Excavation L. S. $

LUMP SUM TOTAL L. S. $

NOTE:

It shall be this Contractor's responsibility to determine the exact quantities required for the abovelump sum item. Estimates given in these specifications are only approximate quantities of in-place material and are for reference only.

IV. CONSTRUCTION SCHEDULE

A. Site Visit 1996 April 30

B. Submit Lump Sum Cost Estimate and Work Plans 1996 May 01

C. Mobilization and Excavation 1996 May 27

D. Demobilization and Decontamination 1996 May 31

V. SITE CONDITIONS

DAVENPORT WORKS

The Contractor shall, during site visitations, make careful examination sufficient to thoroughlyassess the nature and location of the work; access to the work area; character, quality, and quantity of thematerials involved; kind of equipment and facilities needed preliminary to and during performance of thework; general and local conditions; designated areas for staging, stockpiling, and disposal; and any othermatters which can in any way affect the work.

Safety

The Contractor and it's employees shall conform to all Federal, State, and local safety regulationsincluding OSHA standards, IOSHA standards, referenced Alcoa standards, "Davenport Works SafetyManual for Contractors' Operations", and applicable sections of the Comprehensive Health and SafetyPlan for CERCLA Assessment Activities, Alcoa Davenport Works. The Contractor shall provide a SiteSafety Plan design to protect on-site personnel and surrounding areas from any hazards from thisremediation work. The Contractors site safety plan shall address specific safety concerns related to thecontaminants of potential concern (PCBs and TPH) and shall include discussions of protective gear,decontamination procedures, emergency procedures, emergency procedures, site access control, personneltraining.

Contractors Construction Plant

The Contractor shall provide it's own office, and other facilities necessary to complete all workcovered by this contract. All temporary buildings and services shall be located and approved by Owner'sEngineer. Upon completion of this Contract, all the Contractors facilities shall be removed to thesatisfaction of the Owner's Engineer.

SCALE

GERAGHTY& MILLER, INC.

Environmental Services

LOCATION AND PHYSICAL SETTING SETTINGOF THE ALCOA-DAVENPORT WORKS PLANT

FIGURE

876-B 876-C , 876-A

GERAGHTY& MILLER, INC.

Environmental Services

LOCATION OF BUILDING 876

NU

876-7

A ND

OIL

TANKS

EXTENT OFSEPARATE-PHASE OIL

876-10ND

2.3 ( f - i r)

876PUMP HOUSE

•" ND876-8

88 (T-2/)^

876-410(XL'-2') 876-6

NO

88

HOLLOW-STEM AUGER BORING

SPLIT-SPOON ONLY

HAND AUGER BORING

NONE DETECTED

PCB-1248 CONCENTRATIONS(mg/kg) DEPTH INTERVALINDICATED IN PARENTHESES

SCALE

10 20 30 FT

GERAGHTY& MILLER, INC.

Environmental Services

PCB-1248 CONCENTRATIONS (mg/kg)IN SOIL SAMPLES NEAR BUILDING 876

ALCOA-DAVENPORT WORKS PLANTRIVERDALE, IOWA

FIGURE