DVIXEAMACCORPORATION

Dynamac CorporationPublic Ledger Building6th and Chestnut StreetsSuite 872Philadelphia, PA 19106

Telephone: 215-440-7340Fax: 215-440-7346

March 14, 1990

Ms. Christine ChulickU.S. Environmental Protection AgencySE Pennsylvania Section/3HW21841 Chestnut BuildingPhiladelphia, PA 19107

Re: EPA Contract No.: 68-W9-0005Work Assignment No.: CO3019Work Assignment: Eastern Diversified Metals FS Report

Dear Ms. Chulick:

Dynamac has reviewed the Draft Feasibility Study (FS) Report forthe Eastern Diversified Metals (EDM) site (the Site) in SchuylkillCounty, Pennsylvania. The FS document was prepared byEnvironmental Resources Management, Inc., and was submitted to theU.S. Environmental Protection Agency (EPA) on February 5, 1990.This study was part of the Consent Order with EPA dated October 19,1987 (File 720-01). The objectives of this study were outlined inthe RI/FS Work Plan approved March 25, 1988.

The format of the FS Report follows the suggested FS Report formatprovided in the "Guidance for Conducting Remedial Investigationsand Feasibility Studies Under CERCLA" (October 1988). The sectionsare numbered differently but cover the three suggested phases,including identifying the remedial action objectives andtechnologies, developing and screening alternatives, and providingdetailed analysis of the alternatives. The last section of thereport provides a summary and comparison between the selectedalternatives.

In general, the report provides a well presented analysis of thepossible options that are available to remediate the Site. Thereport evaluates a broad range of innovative technologies, resourceconservative process options, and pollution preventionalternatives. The screening and analysis of the developedalternatives follow the nine required evaluation criteria outlinedin the National Contingency Plan.

Corporate Headquarters: The Dynamac Building, 11140 Rockville Pike. Rockville, Maryland 20852 •

Eastern Diversified Metals FS ReportW.A. No. C03019March 14, 1990

The report should include a detailed analysis for the off-Sitedisposal alternative. For deep bedrock groundwater remediation,the alternative should analyze the option of having one or twoshallow recovery wells closer to the fluff pile and should notinclude plans for a deeper bedrock well.

The format of this letter report includes a brief discussion on thereasons to include off-Site disposal as an alternative and then afew comments on the other selected alternatives and theirassociated costs and assumptions.

SECTION 3 - DEVELOPMENT AND SCREENING OF ALTERNATIVES

Off-Site Disposal

This alternative should not have been eliminated from a detailedevaluation. The three criteria for accepting this alternative forfurther analysis are:

Implementabilitv: There are at least two facilities listed in thedocument that could take the fluff materials; the South Carolinalandfill and the Emelle, Alabama landfill. If one or both of thesefacilities would take 18,000 tons/year of fluff, the Site would beclear within 5 to 10 years. The remediation schedule would not beunusually long, even if it lasted the full 10 years.

Effectiveness; The long-term risk associated with the fluff at theSite would be greatly reduced. Contaminated soils and sedimentswould also be removed so that most Site risks would be eliminated.The long-term groundwater contamination threat would be eliminatedand with the continuation of an effective shallow groundwatercollection and on-site treatment program, the groundwater qualitywould be improved and available for future use. This alternativeis more effective in reducing the risks associated withcontaminated ground water than the in-place closure alternative.There would be no wastes on Site to leach, whereas under the in-place closure, the existing fluff materials will always have thepotential to form leachate.

Cost; The estimated costs involved in removal, transport and off-Site disposal will be high, however this alone should not cause thealternative to be eliminated. Based on an average cost of $350/ton(given in the detailed alternative analysis for off-site disposalof selected contaminated soils) the costs for off-site disposal of187,000 tons of EDM waste would be $65,450,000.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. COS019

SECTION 4 - DETAILED EVALUATION OF ALTERNATIVES

No Further Action;

The evaluation of this alternative is required by SARA and reflectsthe current conditions and risks associated with the Site. Theimportant information provided in this evaluation is the estimatedcost of the current operations at the Site, primarily thecollection and treatment of shallow groundwater and leach'ate.Operation and maintenance costs for a 30 year monitoring periodtotal $966,000, with an estimate of $35,000 for the leachatetreatment system. These costs seem reasonable.

Bulk And Plastics Separation Recycling and Shallow GroundwaterCollection/Treatment;

The bulk recycling with shallow groundwater collection is thealternative selected as the most desirable by the PRPs. It is veryattractive in that the waste fluff pile becomes a potentialresource and the alternative then fits under resource conservation,pollution prevention, and alternative technologies policies. Thesepolicies are important concepts and issues that EPA Headquartersare closely monitoring. However, the time frames, Site conditions,and schedules for remediation required for this Site may not allowthis alternative combination to work.

Comments on the bulk and plastic separation recycling alternativesinclude:

• Safe bulk processing (including separation) technologiesfor the contaminated waste plastics are not presentlyavailable and as stated in the FS report it might be 5to 10 years before they come into use.

• The recycling market for clean plastics is just gettingoff the ground. At present, only selected kinds ofplastics are being considered for recycling and therecycled product is very specific. Recycling centers forthose specific "clean" plastics are being established inPhiladelphia, Chicago, and New York. However, thesecenters would probably not consider reusing plastics thatare associated with hazardous wastes and that containsuch a very high lead content.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. COS019

The recycling market for any material is an unknownventure. Paper recycling has been around for 10 yearsand has gone through many changes. At first, therecyclers paid for each ton of paper that they received,now the recyclers are charging for each ton used and theprice is going up. It would be impossible to estimatethe costs associated with plastic recycling.

The costs shown on Table 4-5 for recycling indicate thatthe low cost option includes a negative $2,500,000 forthe sale of the plastic. This would be very unlikely.To be conservative, assume you would get the same amountas you might pay ($3.00/Cy) or $717,000. This increasesthe low-end bottom line by $1,673,000 for a new total of$5,702,000. The high end cost would still be$10,753,130.

Costs shown on Table 4-7 for recycling do not include anyamount for fluff loading or transportation. If we assumethat these are the same as Table 4-5, then an additional0.7 to 2.75 million dollars should be added to the bottomline.

To compare the costs of the other options on an equalbasis; the costs of off-site disposal and incinerationlisted in Tables 4-5 and 4-7 should be projected forward10 years at 5% interest rates, and then added to thebottom line.

If processing technologies and a market are developed,then the processing of the waste still would take 10years. This is the time frame it would take for removaland off-site disposal, just by itself.

Polychlorinated biphenyls (PCB) and dioxin contaminatedwastes would still need to be disposed at an off-Sitesecure landfill. Other non-recyclable materials wouldalso need to be left on Site. It is estimated that67,000 tons or 1/3 of the total waste pile could not berecycled. Of this amount, 4,000 tons are PCB wastes and400 tons are dioxin waste. The remaining 62,500 tonswould be spread out on the Site and covered with 1 footof soil. This material presents a continuing risk forcontamination of the ground water and would increase thetime required to remediate the ground water.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

• The low end cost estimate in Table 4-7 presents $0 forresidual waste handling and a multilayer cap; there willbe some wastes left on the Site so a value should beincluded. The cap will cost $1,000,000 and handling(assume 10% of waste pile) could be $150,000. New totalswould be $7,800,000 and $11,904,000.

If bulk process recycling takes place off Site, then therisks associated with transport and handling are similarto the risks presented in off-site disposal

• The PCB and dioxin contaminated plastics and theexcavated soils and sediments should be treated ordisposed as soon as remediation starts and not storedfor an additional 10 years.

An interim synthetic (plastic) cap may not be able to beplaced on the fluff pile as it now stands because ofslope-failure issues. No statements were made concerningthe risk of slope failure in the associated cap over the10 years nor of the resulting hazards. There should besome assessment of the risk and of the corrective actionsteps needed, if a slope failure occurs.

• The temperature within the fluff material may increaseif a plastic cap is placed over it. This could increasethe risk of internal burning or "slow cooking" of theplastic materials. Will the temperature probes andmonitors be retained and evaluated? What evaluation andcorrective measures would the PRPs take in response toan increase in temperatures?

• The composition of the fluff, in terms of hazardousconstituents, PCB and dioxin contamination and mixed non-recyclable wastes should be defined for the bulk orentire mass of the fluff. If the composition is notdefined before they cap the pile it could turn out thatonly a small percentage (15 - 50%) of the material isrecyclable and the rest still needs to be treated anddisposed.

The extent of groundwater contamination is not well defined inthe shallow and intermediate bedrock zones. Additional wells willneed to be drilled during the design phase of the program.Comments on the shallow ground water alternative include:

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

• The present shallow groundwater trench system is notintercepting all of the leachate and contaminated groundwaters. If this system is not upgraded, thecontamination will continue to seep into the intermittentstream, and pose a potential hazard.

A deep trench design installed to the bedrock surfaceshould be very effective, if it is properly constructedand extends the length of the intermittent stream thatis potentially fed by the overburden flow. A trenchsystem of the proper design might cost $40,000. Noseparate cost estimates were provided for the deepenedtrench.

Recycling and Shallow and Deep Groundwater Collection/Treatment

This alternative provides for additional control and treatment ofcontaminated ground waters. A new, upgraded groundwater collectiontrench is installed and a deep bedrock production or recovery wellis planned. The wastewater treatment plant is redesigned to treatthe additional ground water.

Comments concerning this groundwater remediation alternativeinclude:

The deep (200 foot) production well, producing from anopen hole, would recover a great deal of "clean", non-contaminated water in addition to the small amount ofcontaminated water.

The treatment plant is being redesigned to treat thisadded volume (130 gallons per minute) of mostly cleanwater.

• Costs for drilling and equipping a deep well are veryhigh compared to drilling shallow recovery wells.

Costs reflecting this new well, trench, and treatmentsystem are provided in Table 4-6 only as a lump sum of$300,000. This amount seems low for a deep well and forthe new design of the wastewater treatment plant.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

• If this deep well is located at the western end of thefacility and pumps at 130 gallons per minute from an openhole, then there will be a significant impact on thewetlands west of the area and on the intermittent stream.

• One or two shallower production wells, located closer tothe fluff pile in the more contaminated portion of theplume would reduce both of these problems. The shallowwells would produce a greater percentage of contaminatedwater that could be treated by the leachate treatmentplant. In addition, if this treated water is returnedto the intermittent stream above the wetland than thissensitive area would not be as severely impacted. Costsfor drilling and pumping the shallower wells will be lessthan a deep, large production well.

In-Place Closure and Shallow Groundwater Collection/Treatment

This alternative provides moderate to high levels of protection tothe public and is a proven technology. The RCRA-type cap is a goodpreliminary design. Some comments and additional components ortasks required for in-place closure include:

The internal leachate drain is an excellent plan.Horizontal or inclined drillholes into the fluff thatjoin with the leachate drain would increase the internaldrainage.

• The existing groundwater interceptor trench and therecommended internal leachate collection trench arereversed in the legend of Figure 4-1.

• The PCB and lead contaminated soils and sediments shouldbe disposed off Site in a secure landfill. This wouldadd $425,000 to the cost.

The existing PCB contaminated fluff should be disposedoff Site, at an additional cost of $1,369,000.

• The dioxin containing fluff should be incinerated at aregulated facility. This could cost an additional$500,000 to $1,000,000.

The new total for this alternative is $7,855,000.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

• There should be an assessment of risk related topotential failure of the cap and the steps needed forthe required corrective action should be described.

In-Place Closure and Shallow and Deep GroundwaterCollection/Treatment

This alternative combination has the same advantages as thealternative just reviewed plus the addition of deeper, morecomplete groundwater contamination control and cleanup. Thecomments provided under the In-Place Closure with ShallowGroundwater Collection and under the Plastic Recycling and Shallowand Deep Groundwater Collection/Treatment alternative apply to thisalternative.

The extra components, costs for off-Site disposal, discussed forthe In-Place Closure will add additional costs for this alternativecombination as well. Additional costs could total $2,800,000.The deep well option should be replaced by two shallow wells closeto the fluff pile, and the treated waters should be returned to theintermittent stream above the wetlands.

On-Site Incineration

On-Site incineration is always a costly alternative. The processwill provide the most effective cleanup of the organic compoundsat the Site but has potential drawbacks associated with metalsvolatilization and leaching from the ash residue.

Some comments on the assumptions and proposed costs include:

• Incineration would require at least 3 years for start-up, including alterations to the scrubber or condenser.

The initial feed rate for the plastics into theincinerator was 8 tons/hour. This is in the high rangefor feed rates. Commonly the feed rate might be 4tons/hour. At this rate of 4 tons/hour, it would take7 years to incinerate the waste pile. However, this ratemay have to be decreased further to meet strict new airemission standards. The FS report outlines all of theserequirements.

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

• There is a range in feed rates and remediation time basedon the new Tier I standards. The report calculates arange of remediation times from 1 year for arseniccontamination and emission to 87 years based on potentiallead emissions. Lead will be the most difficultcontaminant to control in the emissions.

• Tier II standards indicate even higher remediation times,up to 5,000 years for lead emissions. The assumptionsused to calculate these rates are that the Site is incomplex terrain, is an urban area, and there is a 20meter stack height. The air emissions model should bererun using smooth terrain condition and a rural setting.The emissions rate for lead will still have the dominateeffect on the potential remediation times.

• A Site-specific air emissions model and treatability testprogram should be planned.

• Tier III risk analysis does provide for a more realisticview of the potential remediation times and feed rates.Tier III assumptions correctly indicate a feed rate ofapproximately 2.4 tons/hour and a remediation time of 9years.

• The costs provided in Table 4-11 for on-Site incineration($500/ton) are in the high range but are valid.

Summary and Recommendations

The draft Feasibility Study Report for the EDM Site is generallycomplete and is presented in the correct reporting format. Foreach alternative selected for review, the detailed screening andanalysis section followed the nine required evaluation criteria.

Dynamac strongly disagrees with the proposed single deep bedrockwell as the option for the deep groundwater collection andtreatment. A deep hole is expensive, but more importantly, thedeep well would produce a large volume of "clean" water for thesmall amount of contaminated water it produced. Additionally, thedeep well, located at the western end of the property would havea strong, negative impact on the nearby wetlands.

Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. CO 3 019

A better option is to drill shallow recovery wells, closer to thepotential source (the fluff pile) and to treat the produced waterand return it to the intermittent stream above the wetlands.Dynamac recommends that this option be evaluated, including ananalysis of costs.

Dynamac also recommends that the entire groundwater remediationprogram be approached as a separate phase or operable unit. .Thefirst component of this unit would be the installation of a newinterceptor trench through the overburden into bedrock. Thissystem should direct all leachate and contaminated, shallow groundwaters to the wastewater treatment facility. The upgraded trenchshould eliminate most of the groundwater flow to the intermittentstream above the treatment plant, but the water will be replacedat and downstream of the plant. The contaminated surface waterseeps on the intermittent stream will also be eliminated. Twoadditional monitoring wells should be drilled in the shallow andintermediate depth bedrock. These wells should be designed to beconverted to recovery wells, if required. Monitoring these newwells and the existing monitoring network would allow the EPA todecide if pumping of the bedrock aquifer is required.

Table 1.0 is a summary of Dynamac 's estimated total costs for theselected alternatives.

The other operable unit would be the fluff pile and surroundingcontaminated soils and sediments. The FS provides a good analysisof the various remediation alternatives. The option most favoredby Eastern Diversified was the recycling of the plastic materials.The unknowns, timing and potential market, involved with thisresource conservation option are its worst points. The overallcost of this option is close to the in-place closure option. Allthe PCB and dioxin contaminated fluff as well as all the excavatedcontaminated soils and sediments should be disposed or treated nowand not stored under an interim cap.

If you have any questions concerning the above comments, pleasecall me at (215) 440-7340.

Sinceely,

BruoeBeachProject Manager

cc: Elaine K. Spiewak, EPA Region III, Project OfficerJohn J. Lindsay, Dynamac Regional Manager

10

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Ms. Christine ChulickEastern Diversified Metals FS ReportWA No. C03019

TABLE 1.0SUMMARY OF COSTS

Alternative Estimated Total Costs

No further Action $966,000

Recycling (Bulk)Shallow Ground Water $5,702,000 - $10,753,130

Recycling (Separation)Shallow Ground Water $8,794,130 - $13,054,000

Recycling (Bulk)Shallow and Deep Ground Water $8,135,500 - $13,175,630

Recycling (Separation)Shallow and Deep Ground Water $11,216.630 - $14,326,630

In-place ClosureShallow Ground Water $7,855,000

In-Place ClosureShallow and Deep Ground Water $8,990,000

Off-Site Disposal $65,450,000*

On-Site IncinerationShallow Ground Water $152,000,000*

On-Site IncinerationShallow and Deep Ground Water $154,000,000*

*Estimates

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/IR303336

UNITED STATES ENVIRONMENTAL PROTECTION AGENCYOFFICE OF RESEARCH AND DEVELOPMENTRISK REDUCTION ENGINEERING LABORATORY

CINCINNATI, OHIO 45268

DATE: March 26, 1990

SUBJECT: Handling PCB "Hot Spots" at Eastern Diversified Metals(EDM) Site

FROM: Benjamin L. BlaneyChief, Technical Support BranchSuperfund Technology Demonstration Division

TO: Christine ChulickRemedial Project Manager, Region III

This memorandum confirms our telephone conversation of March 12th onthis subject. You requested advice on whether solidification is anappropriate approach to handling two types of PCB "hot spots" at the EDM site.One type of hot spot involves approximately 3,000 tons of "fluff" (i.e, wireinsulation plastic) with 50-5,600 ppm PCB. The second type was about 460cubic yards of soil with 50-260 ppm PCB.

We cannot recommend solidification of the fluff. There is insufficientdata available on the stabilization of such high concentrations of PCBs,particularly in plastics material. In addition, we understand that TOSCA doesnot allow stabilization of PCB's over 50 ppm as a treatment technique. Wewould recommend that the "fluff" be combusted at a sufficiently slow rate thatlead emissions are within regulatory limits. This can best be done off-siteat a commercial incinerator with a PCB permit, of which there areapproximately a dozen nationwide.

Similarly, we recommend that the relatively small amount of soil "hot"be treated thermally. This would destroy the PCBs while meeting TOSCAregulations. A low feed rate should result in acceptable lead emissions. Analternative is to treat the contaminated soil with a dehalogenation process(formerly called alkali polyethylene glycol, or APEG). Attached is an articledescribing its application to PCBs in soil at Guam. Please note that recentimprovements in the process (which are being patented) result in a cheaperprocess. Charles Rogers of our Laboratory is the lead person on this processand can make arrangements to have a treatability study conducted on yourcontaminated soil, if you wish to pursue this approach instead ofincineration. His telephone number is FTS: 684-7757.

Please call me at FTS: 684-7406 if you want to discuss this matter anyfurther.Attachment

cc: D. OberackerR. MournighanG. HowellC. WilesC. RogersF. Freestone

\JRESULTS AND PRELIMINARY ECONOMIC ANALYSIS

' OF AN APEG TREATMENT SYSTEM T5I———DEGRADING PCB'S IN SOIL

by:

John A. Wentz,Michael L. Taylor, Ph.D,

William E. GallagherPEI Associates, Inc.

Cincinnati, Ohio

D.B. Chan, Ph.D, P.E.,Naval Civil Engineering Laboratory

Port Hueneme, California

Charles J. RogersRisk Reduction Engineering LaboratoryU.S. Environmental Protection Agency*

Cincinnati, Ohio

ABSTRACT

This paper describes the system and operational procedures utilized aswell as results obtained when the APEG chemical dechlorination process wasscaled up to field-scale and employed to dechlorinate PCB-contaminated soilon the Island of Guam, U.S.A. The APEG system consisted of a steam jacketed,mixer, steam generating plant, and condensate collection system. Approxi-mately 15 cubic yards of soil in batches of 1.5 to 2 cubic yards each withaverage initial PCB concentrations of 3430 ppm Aroclor 1260 were KPEG treat-ed. PCB concentrations of treated soil were reduced by more than 99.999percent with no individual PCB congener exceeding 2 ppm. The demonstrationproved the efficacy of the APEG process to chemically dechlorinate PCB con-taminated soil without the use of DMSO or TMH. Field-scale demonstrationsare being planned for Fall 1989 with modified reagents and optimized operat-ing parameters where the APEG chemical dechlorination process is estimated tocost $200-300 per ton of contaminated soil.

INTRODUCTION

Halogenated chemical contaminants such as chlorinated dibenzodioxins(PCDD's), chlorinated dibenzofurans (PCDF's), and polychlorinated biphenyls(PCB's) have contaminated soil, water, and other matrices in various loca-tions throughout the United States and the world. Because many of thesehalocarbon contaminants have been found to be highly toxic in laboratoryanimal studies, human exposure is undesirable. To date, only limited dis-posal or treatment options are being developed for these contaminants and thematrices they contaminate—particularly soil. The large quantities of con-taminated soil have created a need for a safe, cost-effective, cleanup

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process as an alternative to the current practices of secured on-site stor-age, Class B landfilling, or incineration.

In 1978, at the Franklin Research Center in Philadelphia, Pennsylvania,a reagent was identified and successfully utilized to dechlorinate PCB's inoil.1 The reagent consisted of an alkali metal hydroxide (AOH) and poly-ethylene glycol (PEG) mixture which became known generically as APEG (alkalipolyethylene glycolate). The U.S. Environmental Protection Agency's RiskReduction Engineering Laboratory (U.S. EPA/RREL) initiated further develop-ment of the APEG chemical dechlorination process for PCB oils to includesoils contaminated with PCB's, PCDD's, and other potentially toxic, halo-genated aromatic compounds. Initial laboratory findings indicated thatPCB-contaminated soils could be decontaminated and that further investigationof the process including assessment for full-scale service was warranted.

A typical laboratory-scale procedure for dechlorinating PCB-contaminatedsoil entails mixing potassium hydroxide (KOH) and PEG-400 (average molecularweight 400) to formulate the reagent known as potassium polyethylene glyco-late (KPEG). The KPEG reagent is mixed with the contaminated soil, heated to150°C, and held at that temperature for 1 to 4 hours to allow completion ofthe reaction. Excess reagent is decanted, the soil neutralized with sulfuricacid and rinsed two or three times with water, and the decontaminated soildischarged.

The PCB's, PCDD's, and PCDF's are dechlorinated in a reaction with theAPEG mixture. The reaction of AOH with PEG-400 produces an alkoxide (ROA)(see Equation 1) that, in turn, reacts with a chlorine atom on the aryl ringto produce an ether and chloride salt (AC!) (see Equation 2). Replacement ofthe chlorine atom on the aryl ring with an ether linked PEG detoxifies thecompound.2 The dechlorination process is described in general terms inEquations 1 and 2:

ROH + AOH •»• ROA + HOH (Eq. 1)

ROA + ArCln * ArClp_1OR + AC! (Eq. 2)

Early APEG reagent formulations included solvents such as dimethyl sulfoxide(DMSO) and triethylene glycol methyl ether (TMH). The DMSO and TMH werebelieved to serve as cosolvents to the APEG formulation to enhance reactionrate kinetics by improving rates of extraction of the aryl halide compoundinto the alkoxide phase.3"* Later findings, subsequent to the first pilot-scale APEG chemical dechlorination demonstration on PCB-contaminated soils,indicated that DMSO and TMH could be removed from the APEG formulation with-out hindering the dechlorination process or extending the reaction time.

In June 1987, a pilot-scale APEG chemical dechlorination demonstrationwas performed on a PCB-contaminated site. The pilot-scale demonstration wasone of the earliest attempts to dechlorinate PCB-contaminated soil at pilotscale using a reactor. The system consisted of a reaction vessel, electricalheating elements, and a condensate collection system to collect moisturedriven off of the soil and KOH solution at the elevated temperatures. The

reactor vessel consisted of a 16-inch-diameter pipe, 40 inches long, that wasloaded with approximately 35 Ib of PCB-contaminated soil per batch. A'pre-mixed reagent formulation of DMSO, TMH, and PEG-400 was added to the soil,then 45 percent KOH solution added separately. The treatment parametersutilized mimicked those used at laboratory scale. Initial PCB concentrationsof the batches ranged from 133 to 7013 ppm and averaged 1990 ppm. PCB con-centrations of the treated soil batches ranged from 1.09 to 12.4 ppm andaveraged 5.6 ppm, representing an overall PCB destruction rate of more than99.7 percent.

The satisfactory reduction of PCB's in the soil at the pilot scale leadto the U.S. EPA/RREL's decision to design, construct, and demonstrate theefficacy of a larger KPEG chemical dechlorination system. The proposedfield-scale system would be capable of treating 1 to 2 cubic yards of con-taminated soil per batch at a remote location.

EXPERIMENTAL METHODS

DESCRIPTION OF SELECTED SITE FOR FIELD-SCALE KPEG DEMONSTRATION

The U.S. Navy Civil Engineering Laboratory (NCEL) and U.S. EPA/RRELagreed upon a U.S. Navy site for the field-scale demonstration. The U.S.Navy Public Works Center (USN PWC) site on the Island of Guam, U.S.A. wasselected when analytical results of the collected soil samples indicatedaverage PCB concentrations of 2500 ppm with "hot spots" as high as 45,860 ppm(4.58 percent). Soil contamination found mainly in a nearby storm drainageditch resulted from leaks from a transformer rework building that had beenused as early as World War II. The waste PCB oil that was stored outsideleaked and was carried by surface runoff into the ground.

In preparation for the field-scale KPEG treatment demonstration, a 60-ftby 40-ft metal building was constructed on a 100,ft by 100 ft concrete padand was used to stockpile the 20 cubic yards of excavated PCB-contaminatedsoil. The excavated soil was screened mechanically to separate particles1/2-inch and smaller. Of the 20 cubic yards, approximately 15 cubic yardspassed the 1/2-inch screen and were stockpiled for treatment. The remaining5 cubic yards consisted of coral and rock ranging from 1/2 to 12 inches indiameter. The oversized material was stockpiled separately for subsequentspecial processing.

BRIEF OVERVIEW OF MIXER SELECTION

The type of reaction vessel used for the pilot-scale demonstrationalluded to above was not conducive to the order of magnitude of size for theproposed field-scale demonstration. A mixer system was required that wouldprovide sufficient capacity and mixing capabilities for the KPEG/soil mixtureas well as provide efficient heat transfer. The mixer was selected basedupon the demonstrated mixing range and heat transfer efficiency as determinedby mixer manufacturer facility tests and scale^up potential.

Various mixers were evaluated at several mixer manufacturer's facil-ities. At each facility, prototype mixers were charged with noncontaminatedsoil, DMSO, TMH, PEG-400, and 45 percent KOH. The mixers were turned on andheated with either hot oil or steam through the external jackets. Physicaland operational data were collected,, and the mixer was selected that affordedthe widest range of mixing and greatest heat transfer efficiency.

.DMSO REMOVAL FROM KPEG FORMULATION

During the design phase of the field-scale KPEG system, the U.S. EPA/RREL initiated laboratory treatability studies to determine the KPEG chemicaldechlorination effectiveness on PCB-contaminated soil without DMSO or TMH.U.S. EPA/RREL laboratory results indicated that DMSO and TMH could be removedfrom the KPEG formulation without hinderance to the chemical dechlorinationprocess or extension of reaction time. The removal of DMSO from the formula-tion was also appropriate from a health and safety point of view. The ex-cellent solvent characteristics of DMSO, coupled with the known rapid rate ofskin penetration by DMSO, posed serious concerns for workers in the presenceof compounds such as PCB's and PCDD's.

FIELD-SCALE KPEG TREATMENT SYSTEM

A block flow diagram of the KPEG chemical dechlorination system designedfor the demonstration on the USN PWC site on the Island of Guam, U.S.A., isprovided in Figure 1. The diagram illustrates that the mixer was the primarycomponent of the system where the chemical dechlorination process occurredand was supported by ancillary equipment to make the system functional. Anextensive pipe network was required for interconnecting the auxiliary systemsto each other and to the mixer. To reduce the complexity of the pipingnetwork, a centralized pipe rack was installed. Figure 2 provides a layoutof the site plan of the KPEG demonstration in Guam. The site plan illus-trates the location of the equipment, pipe rack, and exclusion zone. Thesite plan indicates that the majority of the auxiliary systems were locatedoutside the exclusion zone to provide easy access. Only equipment contactingthe soil in its contaminated state or required to be located near the mixerbecause of physical limitations was located within the exclusion zone.

Mixer

The selected mixer was designed with a total capacity of 793 gallons(106 cubic feet) and a working capacity of 490 gallons (65 cubic feet). Themixer was equipped with a 2-speed, 75-horsepower motor and gear box capableof providing mixer shaft speeds of 30 and 60 rpm. All potentially wettedparts were comprised of 316 stainless steel to prevent corrosion from chemi-cal attack. The mixer was provided with an 8-inch-diameter shaft that ranthe length of the mixing cylinder, which was supported at each end by posi-tive-flow nitrogen purged seals. Extending radially from the shaft were armswith plows that maintained a 5/8-inch tolerance from the wall. A maximumtolerance of 5/8 inch between the plow and wall was recommended by the manu-facturer without substantially sacrificing mixing and heating efficiency bycreating a dead zone where caking could occur. This 5/8-inch tolerance alsoestablished the maximum allowable particulate size of 1/2 inch to preventparticulate jamming between the plow and wall.

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Figure 3 is a diagram of the selected mixer and designed features.Three 2-inch and one 1-inch flanged liquid charge ports were located alongthe top of the mixer for PEG-400 and sulfuric acid addition. One 1-inchcharge port was provided at each headwall of the mixer for water addition. A12-inch Teflon-coated rupture disc was provided at the top of the mixer as aprecautionary measure against over-pressurization of the mixer. A 2-inchvent was also provided that vented to the condensate collection system.

Solids were loaded into the top of the mixer through a 20-inch by24-inch rectangular flange. A 16-inch flanged screen assembly with a 2-inchdrain was provided at the bottom of the mixer for reagent draining followingtreatment. Treated soils were discharged from the mixer through an 8-inchair-operated ball valve located on the bottom center of the mixer.

The mixer cylinder was provided with a steam jacket rated at 80 psi(156CC). A manifold was provided across the top and bottom of the steamjacket. During heating, steam entered the top manifold, traversed downwardthrough the jacket, and exited the bottom manifold. The manifolds weredesigned to serve as part of the cooling system as well. Rearrangement ofthe valves allowed for upflow of cooling water through the jacket.Platform

The entire mixer/motor assembly was mounted on a platform to elevate thedischarge port sufficiently to allow for placement of a soil-collectionhopper underneath the mixer for discharge. The platform was designed withcatwalks around the mixer for access. The catwalks folded down for transportin order that legal road widths were not exceeded. The platform was designedwith an integrally mounted jib crane for lifting drums of soil and dry KOHfor charging into the mixer.

Liquid Reagent Loading

The liquid reagent loading system consisted of a pallet scale and air-operated diaphragm pump. PEG-400 was placed on the scale and tared. Thepositive displacement pump was used to charge proper quantities of PEG-400into the mixer.

Heating System

The heating system was a leased package steam generating plant. Designcalculations based upon approximated soil and moisture content and reagentsindicated that a 600-1b-per-hour, 80-psi unit was required to heat the mixercontents from ambient temperature to 150°C within a 4-hour timeframe. Greaterpressure steam (higher temperature) could not be used because the steamjacket rating on the mixer was 80 psi. The mixer steam manifold included asteam pressure relief valve specified at 80 psi.

Nitrogen System

The nitrogen system was provided in the design as part of the safetyconsideration in the event DMSO and TMH were not removable from the KPEGformulation. The nitrogen system consisted of a pressure regulator and flow

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AR3033i*6

controller. Nitrogen was purged into the mixer through the seals to displaceambient air. The removal of DMSO meant the nitrogen was no longer requiredand its use was discontinued when it was learned the seals would not becomedamaged without the nitrogen flow.

Condensate Collection System

The condensate collection system was designed to collect and condensemoisture vapors vented from the mixer while at elevated temperatures. Thecondensate collection system consisted of a 2-inch vent line connected to aknock-out tank that was used to remove any solids which may have been throwninto the vent line from the rigorous mixing action. The knock-out tankvented to a fan-cooled condenser where 9600-cfm ambient air was blown overthe condenser coils. The fan condenser drained into a condensate collectiontank, which originally vented into a secondary condenser consisting of acopper coil submerged in an ice bath. Restrictions in the line size at theice condenser created back-pressure on the system, which necessitated itsremoval. The condensate collection tank was then vented directly to anactivated-carbon column for collection of any remaining volatilized organics.

Process Cooling Water System

The hot treated soil contained within the mixer cylinder required cool-ing prior to further processing. The process cooling-water system consistedof a 1250-gallon water tank and centrifugal pump assembly. Piping on themixer manifolds was revalved to allow cooling water to upflow through themixer jacket and return to the water tank. The process cooling-water systemalso provided the feedwater directly into the mixer cylinder when the soilwas rinsed in an attempt to recover reagent.

Reagent Collection System

The reagent collection system was included in the design to attempt torecover and reuse a portion of the KPEG dechlorination reagent. The reagent,collection system consisted of two 1-inch liquid charge ports on the mixerheadwalls, a 16-inch screened flange assembly with a 2-inch drain on thebottom of the mixer, and two 500-gallon steel tanks immediately adjacent tothe mixer. Ideally, following treatment, the soil was washed byj?umping.process cooling water directly into the mixer through the 11qu1dI£Mrflej30rts•grid aJJewing mixing. The reagent would be allowed to drain through thescreen assembly and 2-inch drain line into the 500-gallon tanks for potentialreuse. The first-attempt at thp snil vash and reagent drain proved futile.Sutoequefit- batches were not washed-or elr-afn€4£jSj££fc£_£eAgej ^ t r a -l«a±ioja. Alternative methods for KPEG reagent recovery would be requireHshould reagent recovery prove essential to the economics of the process.

Neutralization System

The neutralization system consisted of a pallet scale, sulfuric acid,and drum pump. A stoichiometri'c quantity of sulfuric acid was pumped JrttojJhg_mixer to neutralize the known quantity of_KOH.the high calcium carbonate(CaCOg) content of the soil required additional acid to reduce the mixercontent pH to a range within 6 to 9.

OPERATION OF THE FIELD-SCALE KPEG TREATMENT SYSTEM

The mixer was charged with 3400 1b of PCB-contaminated soil, 1555 Ib ofPEG-400, and 285 Ib of KOH. The mixer was turned on to high speed (60 rpm)to mix the soil and reagents. The vent line from the mixer to the condensatecollection system was opened, the fan condenser turned on, and the steamgenerating plant ignited. Eighty psi (156°C) steam was circulated throughthe mixer jacket until the mixer contents reached 150°C, as indicated by thethermocouple readouts. Steam pressure was reduced to 70 psi (150°C) and thetemperature and mixing maintained for a 4-hour period. At the completion ofthe 4-hour period, the steam generator and mixer were shut down. The fancondenser was turned off and the contents allowed to cool overnight.

Following overnight cooling, the mixer contents had dropped from 150° to90°C. Additional cooling was performed by recirculating cooling water fromthe process cooling water system in the upflow manner through the mixerjacket until the mixer contents were cooled to 50°C. The cooling waterremained on and a stoichiometrically calculated quantity of sulfuric acid waspumped into the mixer in 20-lb increments. Because of the known presence ofhigh CaC03 concentrations in the Guam soil, additional sulfuric acid was re-quired to adjust the pH to within a range of 6 to 9. Samples were collectedfrom the sample collection port on the mixer, and the slurry pH was measured.Additional 20-lb increments of sulfuric acid were added, and the pH measure-ment process was repeated until the pH was within the 6 to 9 pH range. Thestrong exothermic reaction during acid addition reelevated the temperature ofthe mixer contents. The cooling water continued to pass through the mixerjacket until the mixer temperature was returned to 45°C. During the entirecooling process, cooling water initially at an ambient temperature of 25°Cwas elevated to 40°C, which represented a significant transfer of heat awayfrom the mixer.

A soil collection hopper was placed under the mixer discharge valve.The air-operated valve was controlled from the mixer control panel mounted onthe mixer, which was accessible from the platform catwalk. The mixing actioninternal to the mixer cylinder directed the contents to the discharge port.After the treated soil was collected in the soil-collection hoppers, thehopper lids were securely fastened. The soil collection hoppers were storedin a secured area on site, awaiting analysis.

RESULTS

VERIFICATION OF PCB DECHLORINATION

On-site analyses of untreated and treated soil were performed by usingextraction and gas chromatographic mass spectrometric (GC/MS) methods adaptedfrom EPA Methods (SW 846, 3rd Edition). Corroborative analyses on duplicatesamples of the untreated and treated soil and on collected condensate andrecoverable reagent samples were performed by an independent laboratory inthe United States by GC/MS as well. Table I provides the analytical results

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of the pre- and post-KPEG-treated soils from both laboratories, as well asthe percent PCB reduction, PCB concentration in the collected condensate, andPCB concentration in the neutralized KPEG reagent. The PCB concentrations ofthe untreated soil from the corroborative analyses were reported as re-covery-corrected. On-site PCB concentrations of the untreated soil were notrecovery-corrected when reported, thus justifying the consistent discrepencybetween the two laboratory facilities.

The PCB analyses in Table I indicate that the lowest PCB reduction was99.996 percent, while the majority of the reduction rates exceeded 99.999percent. Low concentrations of PCB were identified in the collected conden-sate. For each 1.5-cubic-yard batch of soil that was treated, approximately50 gallons of condensate was collected. Using Batch 4 as an example, initialPCB concentration of the 3400 Ib of soil charged into the mixer was 3778 ppm;thus, the total quantity of PCB can be calculated by Equation 3:

Total Ib PCB in soil = Ib soil x ]|j (Eq. 3)

Placing Batch 4 values into Equation 3 indicates that 12.8 Ib of PCB werecontained within the batch. Analysis of the condensate' from Batch 4 indi-cated a PCB concentration of 13.81 ppm. The total quantity of PCB in thecondensate can be calculated by Equation 4:

Total Ib PCB = 6a1 condensate x pCB conc_ (ppm) x g>34 (Eq< 4)in condensate 1 x 10

Again using values obtained from Batch 4, the total quantity of PCB's trans-ferred from the soil to the condensate was 0.006 Ib of PCB. Therefore, thetotal quantity of PCB's transferred from the soil in the mixer to the conden-sate was less than 0.04 percent of the overall quantity, assuring that thereduction of PCB's in the soil was not the result of PCB relocation into thecondensate by steam stripping.

The collected condensate was passed through an activated carbon systemto remove the residual PCB's. All analyses of carbon-treated condensate werereported as nondetectable. Treated condensate was collected and transportedto the sanitary sewer for discharge.

The results presented in Table I indicate the efficacy of the KPEGtreatment „ for the dechlorination of PCB's. The operation of the system,which was capable of treating 1.5 cubic yards per batch utilizing equipmentthat is readily available for scale-up, indicates that scale-up to full scaleis conceivable, assuming favorable economics. The operation of the systemwas performed without major mechanical or operational problems. Therefore,full-scale design need only enlarge the system and incorporate minor changesto improve operations, particularly the materials handling aspects of thetreatment process.

DISCUSSION OF PROCESS ECONOMICS

The economics of the KPEG chemical dechlorination process must indicatea favorable advantage when compared with other treatment and disposal

flR30-3'35!

practices for the development of the process toward a full-scale system.

The demonstration performed on the PCB-contaminated soil in Guam wasperformed solely to demonstrate the feasibility and potential of the KPEGtechnology. The system was purposefully designed to be labor-intensive fortwo reasons: (1) as a demonstration focusing on the efficacy of the KPEGreagent to dechlorinate the PCB, the system was not automated in order thatcapital expenditures be reduced, and (2) the use of hands-on operation wouldallow for observations and overall intimate knowledge of the system to beacquired. To reduce capital costs even further, all system equipment thatcould be leased was utilized in place of purchased equipment. These leasecharges were initially incorporated into the operational costs per unit ofcontaminated soil, which artificially elevated the operational costs. Otherfactors included in the initial operation costs were all labor, associatedper diem, and automobile charges; major equipment items leased from the U.S.mainland; major equipment items leased while in Guam; diesel fuel; processchemicals; electrical consumption; and contractor profit and overhead.Taking into account a weekly expenditure (excluding unusually uncharacteris-tically high costs associated with performing work in Guam) where six batchesof 1.5 cubic yards (3400 Ib) of PCB-contaminated soil were treated per batch,the operational costs were calculated by PEI to be $1700-1800/ton of PCB-contaminated soil.

The system utilized in Guam only demonstrated the potential use of KPEGreagent for PCB dechlorination. During the demonstration, no attempt wasmade to optimize the reagent formulation or operating parameters. Sincereturning from Guam, U.S. EPA/RREL and PEI have continued laboratory treat-ability studies to optimize the reagent formulation and operating parameters.

From the data concerning a modified KPEG reagent formulation and reducedconstraints upon operation, as determined by the U.S. EPA/RREL laboratory op-timization studies, a full-scale, portable, self-supportive treatment systemhas been preliminarily costed. The estimated capital expenditures for afull-scale system, including equipment and construction costs, are $3.5 to$4.5 million. The system would theoretically be capable of dechlorinating 72tons of PCB-contaminated soil daily, with a more realistic throughput of 54tons per day. Assuming that all equipment is purchased outright and mate-rials handling is automated to reduce excessive labor, operational costs areestimated to be $200 to $300/ton. This cost includes all direct labor andindirect living costs for an out-of-town operational crew, diesel fuel con-sumption, and chemical usage. This cost, however, does not include exca-vation of the contaminated soil or placement back onto the ground followingtreatment; therefore, the overall cost to the client will be slightly higher.

The purpose for presenting the operational costs without including theexcavation or replacement costs was so that a cost comparison can be madewith the current treatment practice of incineration for PCB-contaminatedsoils. A telephone poll of several independent PCB-permitted incineratorsthroughout the country indicated an incineration charge averaging $1713 perton of PCB-contaminated soil. This incineration charge does not includeexcavation; loading into Department of Transportation (DOT) approved drums,since the majority of incinerator facilities will not accept contaminated

&R3Q3352

soil in bulk; transportation of soil to the incinerator site; ash disposal;or any cost associated with replacement of excavated soil with clean fill.

CONCLUSIONS

Based on the projected cost estimates that have been performed, the APEGchemical dechlorination process appears to be superior in economics, assumingthe optimizations obtained in the laboratory are suitable for full-scalescenarios. Advantages of the APEG process are that transportation costs ofcontaminated soil and replacement costs of clean fill are eliminated, sincetreatment is performed on site and treated soil should be suitable for place-merit back onto the ground. Prior to initiating design of the full-scalesystem, additional field-scale demonstrations will be performed utilizing theoptimized parameters determined by U.S. EPA/RREL, NCEL, and PEI. Thesefield-scale demonstrations are currently being planned for Fall 1989.

ACKNOWLEDGEMENTS

PEI is grateful to the technical support and guidance provided through-out the course of the KPEG field-scale demonstration and on-site sampleanalysis on the Island of Guam, U.S.A., by Dr. Alfred Kernel and Mr. HaroldSparks of the U.S. EPA Risk Reduction Engineering Laboratory, Cincinnati,Ohio. PEI is also grateful to Mr. German Dorsey for use of the USN PWC FENAlaboratory where on-site sample analysis was performed as well as Mr. JessLizama, Supervisory Environmental Engineer of the USN PWC site, Guam, forarrangements of construction equipment, supply of utilities, and USN PWCpersonnel for assistance of systems assembly and disassembly.

REFERENCES

1. laconianni, F. J. Destruction of PCBs—Environmental Applications ofAlkali Metal Polyethylene Glycolate Complexes. Prepared for U.S. En-vironmental Protection Agency, Hazardous Waste Engineering ResearchLaboratory, Cincinnati, Ohio. Franklin Research Center, Philadelphia.May 31, 1985.

2. DeMarini, D. M., J. E. Simmons. Toxicological Evaluation of By-ProductsFrom Chemically Dechlorinated 2,3,7,8-TCDD. Accepted for publication inChemosphere, 1989.

3. Peterson, R. L., E. Milicic, and C. J. Rogers. Chemical Destruction/Detoxification of Chlorinated Dioxins in Soils. In: Incineration andTreatment of Hazardous Waste, Proceedings of the Eleventh Annual Re-search Symposium. EPA/600/9-85/028, September 1985.

4. Peterson, R. L. 1986 Method for Decontaminating Soil, U.S. PatentNumber 4,574,013, March 4, 1986.

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