v>EFV\ United States Environmental Protection Agency Office of Emergency and Remedial Response EPA/ROD/RO1-83/007 September 1983 Superfund Record of Decision: Sylvester Site, NH ------- " TECHNICAL REPORT DATA (PlefUe rtfld Instructions on the revene IHfore completing) 1. REPORT NO. 12. 3. RECIPIENT'S ACCESSION NO. .. TITLE AND SUBTITLE 5. REPORT DATE SUPERFUND RECORD OF DECISION: 09/22/83 Sylvester, NH (Supplemental ROD) 6. PERFORMING ORGANIZATION CODE 7. AUTHORIS) 8. PERFORMING ORGANIZATION REPORT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM EL.EMENT NO. ". CONTRACT/GRANT ~O. 12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED U. S. Environmental Protection Agency 401 "M" Street, S. W. 14. SPONSORING AGENCY CODe Washington, D. C. 20460 15. SUPPLEMENTARY NOTES 16. ABSTRACT The Gibson Road hazardous waste dump site is located in the City of Nashua, New Hampshire. The 6 acre site has been used as a sand borrow pit for an undetermined number of years. Some time during the late 1960's the operator of the pit began an unapproved and illegal waste disposal operation. Household refuse, demolition materials, chemical sludges, and approximately 900,000 gallons of hazardous liquid chemicals were dumped at the site. The ground water, air and to a lesser extent surface water have been contaminated. The original ROD was signed in July 1982 approving the installation of a slurry wall and surface cap as the first operable unit. The ROD also approved ground water treatment as the second operable unit but deferred selection of the specific treatment process until the technical analysis and evaluation of the pilot plant studies were complete. The cost-effective ground water treatment system selected for this site includes: inorganic chemicals removal; volatile organic chemicals removal; concen- trated organic chemicals removal; and biological treatment of the sidestream. Also a treatment rate of 300 gpm has been selected to reduce the operating time to approximately 2 years. 17. KEY WORDS AND DOCUMENT ANAL.YSIS . a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group Record of Decision Si te Name : Sylvester, NH (Supplemental ROD) Contaminated media: gw, sw, air Key contaminants: volatile organics, inorganics, heavy metals 18. DISTRIBUTION STATEMENT 19. SECURITY CLASS IT/lis Repo,,/ 21. NO. OF PAGES None 20. SECURITY CL.ASS (TlJis page) 22. PRICE None EPA 'ewlll 2220-1 (Rn. .-n) ------- INSTRUCTIONS " REPORT NUMBER Insert Ihe EPA report number as it appears on the cover of the publil:ation. 2. 3. LEAVE BLANK RECIPIENTS ACCESSION NUMBER Reserved for use by each report recipient. 4. TITLE AND SUBTITLE Tille should indicate dearly and briefly the subject eovera~e of Ihe report. and be disl'lay~'d prolllin~'ntly. S.'I suhlille. if uS~'II. 11\ slIIali.'r type or otherwise subordinate ilto main title. When a report is prepared in mon' than un~' vulume, rcp'atlh.. primary I ill... alld vilhan1\' number and include subtitle for the specific tille. REPORT DATE Each report shaU carry a date indicating at least month and ycar. Indkate Ihc hasis on whkh il \\";1\ .....le~'Icd (q:.. JIlII' i'/ismc'. Jlllc' 0/ Ilpprolllll, d4t~ o{ pr~pIlftlt;on, elc.). 5. 8. PERFORMING ORGANIZATION CODE Leave blank. 7. AUTHORIS) Give namels) in l'\)nventional order (John R. Doc. J. RobC'TllJof.'. c'lt..), List author's affiliallon it. it differs frum th~' j1crfurlllinj: "'j:ani- zation. 8. PERFORMING ORGANIZATION REPORT NUMBER Insert if performing organization wishes to assign this number. 9. PERFORMING ORGANIZATION NAME AND ADDRESS Give name, street, city, state, and ZIP code. List no more than two levels of an orj:anizalional hireardlY, 10. PROGRAM ELEMENT NUMBER Use the program element number under which the report was prepared. Subordinate number, lI\a)' be indu,lnl in p;m'nlh.."". 11. CONTRACT/GRANT NUMBER Insert contract or grant number under which report was prepared. 12. SPONSORING AGENCY NAME AND ADDRESS Include ZIP code. 13. TYPE OF REPORT AND PERIOD COVERED Indicate interim final. etc.. and if applicable. dates covered. 14. SPONSORING AGI:NCY CODE Insert appropriate code. 15. SUPPLEMENTARY NOTES Enter information not included elsewhere but useful. such as: To be published in, Supersedes, Supplements. etc. Prepared in ~oopcralion wllh. I r;l'I\lalioll 01'. I'r~'"'III,''' al ,'011"''''11''' "I. 18. ABSTRACT Include a brief (200 words or lessl factual summary of the mosl sil!OIt'kani Informal ion ,'u'1'4In,'" III ,"" "'pOlI. It 111,' "'porl 'Oll'all'\ J significant bibliography or literature survey. mention II here. 17. KEY WORDS AND DOCUMENT ANALYSIS la) DESCRIPTORS - Select from the Thesaurus of Engineerir.~ and Sdenlll'k Terl'" the prupel aUlh"r,,,'d 1"1111' Ihatldenllfy the maJOI concept of the research and are sufficiently specific and pre\:ise to be used as ande)\ entrics lur calalu~In!!. (b) IDENTIFIERS AND OPEN-ENDED TERMS - Use identifiers for proJcct nam". ~ode lIam~'. ~4u1pment d~"~nalor'. ,'Ic, l.;,c "PCII' ended terms written in descriptor form for those subjects for which no deS4:riptor ~.\ists. (c) COSA TI HELD GROUP - Field and group assignments are to be takcn from the I ~6S (,OSA'II Sul*~t ('ale~..ry I.ist. Sin~~' the ma. jority of documents are multidisciplinary In nature. the Primary held/Group assignmelllt 'I w,lI be ',X'lll II' di" .pline. ar~'a III' human endeavor, or type of physical object. The applicationls) will be cross-rcJ'crcnced with \cI'undary 1,.-Id/C ;10111' J"'f!"mCIIl\ Ihal "'1111..11.." the primary posting(s). 18. DISTRIBUTION STATEMENT Denote releasability to the public or limllation for reasons other than se~uflly for example "I{~lcasc 1;1111111'1"11." ('ilc allY a~a,lah,IrI>' 10 the public. with address and price. 19. Be 20. SECURITY CLASSIFICATION DO NOT submit classified reports to the National Tcchnlcallnformation servke. 21. NUMBER OF PAGES Insert the total number of pages, including this onc and unnumbered page'. but exdude di,trrbution 1i,1. II any. 22. PRICE Insert the price set by the National fechnicallnformation Scrvl~e ur the Government Prlnllng OITi~e, ,I' known, ------- Supplemental Record of Decision. Ground Water Treatment Alternative Selection Site: Sylvester Site, Gilson Road, Nashua, New Hampshire Analvses Reviewed: I have reviewed the following documents describing ~he analysis of cost effectiveness of remedial alternatives at the Sylvester Site: -AA OSWER Record of Decision on Remedial Alternative Selection for the Sylvester Site dated July 29, 1982. -Sylvester Hazardous Waste Dump Site Containment and Cleanup Assessment, Roy F. Weston, Inc., Jan~ary 1982. -Supplemental Study to Final Report on Sylvest~r Hazardous Waste Dump Site Containment and Cleanup Assessment, Roy F. Weston, Inc., July 1982. -Gilson Road Ha%ardous Waste Dump Site Pilot Plant Treatment - Study Pilot Plant Design, Roy F. Weston, Inc., October 1982. -Gilson Road Hazardous Waste Dump Site Pilot Plant Treatment - Final Report, ROY F. Weston, Inc., May 1983. -Gilson Road Hazardous Waste Dump Site Pilot Plant Treatment - Addendum to Final Report, ROy F. Weston, Inc., June 1983. -Gilson Road Hazardous Waste Dump Site Treatment Concerns Report, ROy F. Weston, Inc., September 1983. -Feasibility and Cost Evaluation of Alternative Scheme for Ground Water Flow Regime Manipulation, Goldbe~g- Zoino , Associates, Inc, September 1983. -Staff summary and recommendation. Summary of Original ROD: The original ROD was signed in July of 1982. It selected the installation of a slurry wall and a surface cap as the first phase of remedial action. The ROD approved ground water treatment as the second phase of remedial action but deferred selection of the specific treatment process until the State could complete ------- '. . . -2- Components of the Selected Treatment Process: Ground Water Extraction and Treatment @ 300 gpm. Chemical precipitation of heavy metals pB adjustment Sand Filtrati"on 8igh temperature air stripping of volatile organics Incineration of vapors from ai~ stripping process Recirculation of 250 gpm of treatment plant effluent within the slurry wall. (Recharging: less water back into the containment area will induce ground water flow into the containment area through the bedrock structure.) Biological treatment of SOgpm of treatment plant effluent and injection into the ground water outside the slurry wall. (Additional biological treatment is necessary because it is discharged outside the slurry wall.) Dewatering and on-site disposal of' sludge generated from chemical precipitation and biological treatment processes* Operation of the system to complete the remedial action. *Based on the pilot plant study, the sludge produced by the treatment plant will not be hazardous. Bowever, if the sludge is found to be hazardous, it will be transported off site to an approved hazardous waste treatment or disposal facility. ' Declarations: Consistent with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), and the National Oil and 8azardous Substances Contingency Plan, I have determined that the ground-water treatment action, in conjunction with previous remedial actions taken on the site, is cost effective, and provides adequate protection of.tha public health and welfare, and of the environment. I have also determined that the action being taken is appropriate when balanced against the need to use Trust Fund money at other si,tes. I have determined that treatment of the ground water contained within the slurry wall is necessary because the leakage of contam- inants under the slurry wall (through fractures in the bedrock) is expected to continue and because the long term integrity of slurry wall installation at this hazardous waste site cannot be predicted at this time. , I , - ; . . '. . , ~ I .;'.......:'. t~. \ '--- :' '" \ " '. --, ,....,......"'" . Office of Lee M. Thomas Assistant Administrator Solid Waste and Emergency "IJ :'_. . . ~. ,... /. ~ / l' 1 ,~' n...~... ------- Sylvester Site Staff Summary for the Supplemental Record of Decision on Ground Water Treatment Site. Description and History The Gilson Roed hazardous waste dump site is located in tne City of Nashua, New Hampshire, off Route 111, in the south ~aster1y corner of that community. See Figures 1 and 2 for its location. The 6-acre site had be~n used as -a sand borrow pit for an undete~ined number of years. During the late 1960's, the operator of the pit began an unapproved and illegal waste disposal ~~eration, apparently intending tQ fill the excavation. Household refuse, demolition materials, chemical sludges, and hazardous liquid chemicals all were dumped at the site at various times. The household refuse and demolition material were usually buried, while the slupges and hazardous liquids were either mixed with the trash or were allowed to percolate into the ground adjacent t~ the old sand pit. Some hazardous liquids were also stored in steel drums which wer~ either' buried or placed on the ground surface. The illegal dumping at the site was first discovered in late 1970. After several court appearances and court actions, an injunc- tion was issued in 1976 which ordered the removal of all materials from the site. This injunction was ignored by the operator. The first indication that the illegal dumping had included hazardous wastes came in November 1978 when State personnel observed drums being stored at the site. A court order was issued in October 1979 prohibiting all further disposal of hazardous wastes on the site. It is impossible to estimate the total quantit.ies of waste materials discarded at the site. However, it has been documented that over 800,000 gallons of hazardous waste were discarded there during a ten month period in 1979. In 1981, initial investigations showed that there were high concentrations of heavy metals 'and volatile and extractable organics in the ground water under the site. (See Table 1.) The contamination formed a plume in the ground water which was moving from the site toward Lyle Reed Brook at the rate of 0.8 to 1.6 feet. per day. When the volatile hazardous chemicals reach Lyle Reed Brook, they begin to volatize into the atmosphere. The rate of volatili- zation and exposure to the surrounding community was modeled. Based upon this analysis it was determined that volatilization of organic pollutants from Lyle Reed Brook will be well above acceptable limits. Chloroform exceeds life-time exposure levels by 100 times. Exposure from methylene chloride and ethylene chloride are high ------- -2- Under the no action alternative, dilution of organic and inorganic contaminants were not sufficient to eliminate health hazards for the Lowell, Massachusetts, water system users. The arsenic concentration, which was above water quality criteria, was expected to increase by a factor of seven. The water quality criteria for methylene chloride, chloroform, 1,2-dichloro-ethane, trichloroethylene anQ benzene cumulati~ely would have been exceeded by a factor of 7.3. Also, Lyle Reed Brook would not be able to support aquatic life. In the Nashua River, concentrations were expected to approach 40 percent of the accute acceptable limits during the summer months. During periods of extreme low flow fish kills were predicted. Due to the ground water plume migrating from the site to the Nashua River, all ~rivate drinking water wells hydraulically be~ween these locations are unsuitable for use.. Community Relations The public has supported the remedial actions already taken and those proposed in this Record of Decision (ROD). Local citizens have, however, urged the State to initiate action as soon as possible. . EPA communicated its acceptance of the selected remedial actions at a pub~ic meeting on March 30, 1982. Approximately 150 people attended. A meeting will be held in October to review the design of treatment system with the community. Enforcement Actions The State has taken the lead on enforcement actions on this site. A jury awarded $14 million in a State court action. It is highly unlikely, however, that defendants in this matter have assets sufficient to satisfy the court decision.. Region I has initiated a generator search to identify the generators who sent waste to Cannon's Engineering, which was the main source of waste at Nashua. The search should be completed by November 1983. Previous Actions During May and June of 1980, the 1314 drums which were accessible were removed by a contractor and disposed of at approved sites in New ~ork and ohio. This action was funded by EPA under section 311 (k) of the Clean Water Act. In November of 1981, EPA used CERCLA emergency funds to install a ground water interception and recirculation system at the site to retard further migration of the contami~ant plume until remedial action could be. implemented. This system was operated until October 1982, when the slurry wall was completed. The State of New Hampshire completed a remedial investigation ------- -3- in January of 1982. They completed a supplement to that study . in July of 1982, providing additional information on the costs associated with various ground water treatment rates. A ROD was signed by the AA, OSWER in July of 1982. The activities approved in th~-ROD were funded through an amendment to the Cooperative Ag~eement. The selected remedial action included the 20 acre sl~rry wall and surface capas remedial action plan. The State completed slurry wall and cap in December of 1982. The _BOD. also approved ground water treatment, in principle, but deferred the selection of the optimum treatment process until after the State had completed its technical analysis and evaluated the pilot plant studies. the installation or the first phase of the construction of the The pilot treatment plant has now been constructed and operated- for a year. Studies to determine the process train for the treat- ment plant were completed in June of 1983. Current Status The slurry wall is effectively. preventing migration of contam- inants contained in the overnurden aquifer. However, it is not entirely preventing contamination from leaking into the fractured bedrock aquifer below the containment area and, thus, under the slurry wall. This was anticipated and is addressed in the treatment plant design by diverting part of the treated effluent (50 gpm) to ground water outside of the slurry wall. This sidestream will induce ground water flow into the slurry wall through bedrock fractures eliminating further contaminant leakage. out of the containment area. The current leakage rate of 30,000 - 55,000 gpd does, however, make it important that construction of the treatment plant be started as soon as possible. Another factor requiring rapid construction is that many of the hazardous substances inside-the site are destructive to the slurry wall. Therefore, the treatment plant should be started as soon as possible to protect the effectiveness of the slurry wall. Ground Water Treatment The 100 gallon per minute (gpm) treatment plant proposed in the original Record of Decision was expected to require 6.2 years of operation at an annual operating cost of $750,000 and a life-cycle cost of $6,788,000. A larger plant was evaluated that would shorten the period of the remedial action. A shorter treatment period is advantegeous because it would attain the performance objectives sooner and provide better protection of the ------- .' . -4- 30QJ£.~<;i~~e!:Lt.ne..-op.e.rating... time__.t:.9":._L.1.._~ars, which completes the remedial action significantly sooner at a com~arable life-cycle cost ot $7,097,000. The 300 gpm plant is now being recommended for implementation. Table 1 and 2 display capital ana operational costs. The estimated cost of the recommended system is cClr":;',,H'al:>le t~,j the original system. the co.s..t ot both systems may. ~~.r.~~,7~t..~b= r.edl,1_~e.~_o.~w.Q-1...c!"~..Q...rs that have not been' included in:i112 '.:.')':::: estimates: FirstL-.thiL-e..,q1,1j.~~I1~ probably will retain 31: :.='.: . ...d resale_or $~9.EL.y~l_ue (possibly as much as half the' ':~""": purchase price after two years). Second, the current . -~. ..._.~ tor a ~ tU1"'h; nA g.a.n.az:.~ that will use waste ste:<" t-:> ~,:n'=~a'~'= electricity. whoen that elec:.t_;'.~-<;.~J;:l._~~.~.Q!-d to the lc::a1 utilitJ', the project is expected to realize net revenues of app~~xima~~li $100,000 per year. Neither ot these potential revenue scurc~s ~as been included in th~ lite-cycle cost estimates for these systems. ... . Based on the risk assessment it was aetermined that the following reductions inside the containment area are necessary to adequately protect'public health and the environment: Total organic Carbon Chloroform Methylene Chloride Benzene 1,2-dichloroethane Trichloroethylene l,l,l-Trichloroethane Acetone Isopropanal Arsenic 90% 95% 90% 90% 90% 90% 90% 90% 75% 90% The Region I Administrator has concluded based 0" the Nashua teasibility studies that the concentrations remaining in the site after the treatement is stopped will not pose a substantial present or potential hazard to human health or the environment. (Analysis is attached.) The analysis used the criteria of Part 264.93 of the ~CRA Land Disposal Regulations. Volatization from Lyle Reed Creek will be reduced to acceptable exposure levels. Arsenic and organic concentrations will be reduced to below water quality criteria at Lowell, Massachusetts. The likelihood of tish kills in the Nashua River will diminish as tne plume migrates into the river. Lyle Reed Brook will not meet water quality criteria levels but an expanded aquatic population is expected. Finally, all t"esidences using around W-'lT~1'" -'11"'8 tt1reat.e.fl~d ------- -5- After one and a half to two years of operations, the treatment system will be evaluated for the following: o The degree to which treatment goals have been met for the ground water within the slurry wall contairumen~ area. o o The lopg-term integrity of the slurry wall. The amount ot ground wa~er flowing through th~ con~ainmen~ area. w~ exp~ct to attain the designated removal rates inside the contai~ent area after two years of plant operation. This 5u~~~~~ental ROD approves operation of the treatment system tor two years. At the conclusion ot the evaluation, the State and Region I will evaluate the concentration limits and will recommend elther that the treatment plant be shut down or_~_hat its opera~01'lOe-'- contlnued. . . - .....--'-" The basic steps of the recommended grouna water treatment system are: o inorganic chemicals removal volatile organic chemicals removal concentrated organic chemicals incineration biological treatmen~ of ~he sidestream o o o The inorganic chemical removal stage is designed to remove iron and manganese from the ground water. This is necessary to prevent fouling of down stream equipment. An additional benefit of this process is the removal of some of the other heavy metals such as arsenic and lead. This step of the treatment system consists of chemical precipitation of heavy metals, pH adj ustmen~' of the waste water, and sand filtration to remove the preci~itated metals sludge. A sample of th~ sludge has been analyzed using the standard EP-toxicity procedure and was found to be non-hazardous. Samples of the sludge from the full-scale plant will be tested. The sludge will be taken to a RCRA approved treatment or disposal facility if it is found to be a hazardous substance. The next step in the process is the removal of the volatile organic compounds using a high temperature air stripper (HTAS). The contaminated ground water (which has had the metals removed from it in the previous process step) is preheated in two heat exchangers, an economizer and a trim heat exchanger. Over the range of operating temperatures tested, all of the ~riority pollutants and more than 75 per cent ot the alcohols were removed from t~e waste water. The vapor leaving the top of the HTAS will then go directly to a fume incinerator for the removal of the concentrated volatile organic chemicals. The incineration step of the treatment system includes a horizontal fume incinerator, usin~ #2 fuel oil as supplemental fuel, a waste hea~ recovery boiler and a 250KW turbine ------- . . -6- to incineration, but was found to be more costly and less reliable. The incineration process is a well established method for handling vapor-phase organics while avoiding operational problems in meeting stack discharge limits. The turbine generator is expec~ed to be cost-effective for a flow rate of 300 GPM with a payback period of less ~han the expected operating life of the facility. After the, waa~e water discharged from the HTAS is split into two waste streams, the larger stream (of 250 gpm) will be directly recharg~d back into the contaminated area without biological treat- ment. The removal of the small remaining quantities of alcohols and ketortes is neither necessary nor cost-effective for this stream. The side: stream (of 50 gpm) will be treated using an extended aeration, ~ctivated-sludge plant. Additional biological treatment is necessary for the side stream because it is to be discharged just outside of the slurry wall to induce ground water flow into the containment area through the bedrock fractures. In addition to enhanciny the water quality of the 'side stream, the additional removal of alcohols and ketones will avoid any possibility of damage to the outside of the slurry wall. The 50 gpm side stream is adequately treated to protect public health and is discharged on-site into less contaminated ground water just outside the slurry wall. Design of this plant is currently nearing completion and its construction will be funded through an amendment to the Cooperative Agreement. Capital costs of the plant are shown in Table l. Estimated operational costs to complete the remedial action are ------- TABLE 1 Vinyl Chloride Benzene. Chloroform .' Jl,2-Tric~loroethane 'Ethylene Chloride Tetrachloroethylene Tricnloroethylene Xylenes Methyl Isobutyl Ketone Methyl Ethyl Ketone Chlorobenzene . Methylene Chloride'/ Toluene Ethyl Benzene 1,1-Dichloroethane t-l,2-Dichloroethane. l,l,l-Trichloroethane Methyl Methacrylate Ethyl Chloride Tetrahydrofuran 2-Butanol Dimethyl Sulfide Diethyl Ether Methyl Acetate Isopropyl Alchol Acetone : \ HIGHEST CONC. . fUUND IN GROUND WATER (PPB) . 950 3,400 31,000 17 73,000 570 15,000 10,000 21,000 80,000 1,100 122,500 29,000 1,200 lS 18,000 2,000 3,500 320 1,500,000 3,560 3,500 20,000 2,400 26,000 ------- TABLE 2 ESTIMATED CONSTRUCTION COSTS - ITEM CAPITAL COST: 1. :onstruction of treatment building, site work, utilities, and sludge disposal site 985,000 $ 2. Chemical precipitation, neutralizaton, sludge de~atering 635,000 3. High temperature air stripping, incineration, and compliance testing 622,OQO 4. Extraction and recharge system package: extended-aerati~n, activated-sludge plant with nutrient addition to treat purge stream 475,000 5. 340,000, 6. Electrical, instrumentation, piping, and RVAC 857,000 Subtotal $ 3,914,000 7. Contingencies (20%) 782,400 Total Capital Cost ------- . . ITEM - 1. Labor 2. Electricity 3. Fuel Oil 4. Chemicals TABLE 3 ESTIMATED ANNUAL OPERATIONAL COSTS TO COMPLETE THE REMEDIAL ACTION 5. Sludge Disposal (on-site) 6. Maintenance Materials 7. Miscellaneous (Insurance, Phones, etc.) TOTAL COST $262,200 69,000 883,000 96,800 41,400 13,800 13,800 ------- /\ ~ --- \-. N I I , SCALE I": " MILE I . , , I I , fiGURE LOCATION MAP q- :) HOLL/S~. ct. z. HUDSON . . . NEW ItAMPSltlRE MASSACItUSETTS ," 1_- -- NEW HAMPSHIRE ------- t ...."" .... ~~ 0":::' q; Fi ~Iur~ 2... Re I lIa:tarrlous Waste Site IlIvcstigation Sylvester Site. Gilson Road, Nashua, New Hampshire, GIIR Engineering Corp/GZA. Inc. 1981 « u. :> ~ Jensen's Trailer P.rk '. - /. ", Rodger's T railer Parle III e ... ... k .. ~ ::J o U oaY- d 0( . \\Ce Vi \ C 0,.0 ,,~ c.\ \..SO ) FIGURE 1 TIlE AREA SURROUNDING TilE SYLVESTER SITE (NOT TO SCA 1.1:) t~' /V ------- , . DA TE: SUBJECT: FROM: u.s. ENVIRONMENTAL PROTECTION AGENCY REGION I September 22, 1983 - Transmittal of Alternate Concentration Limits for the Gilson Road Site, Nashua, NH Site TO: Michael R. Deland, Regional Administrator, Region I Lee M. Thomas, Assistant Administrator for Solid Waste and Emergency Response (WH-562-A) EPA, Washington, DC I am transmitting to you al~ernate concentration limits for the Gilson Road site which I believe have complete technical support. I would like to potnt out that a comprehensive legal and programmatic review has not been: initiated in the Region. It is my understanding that the issues concerning the interface with CERCLA and RCRA is currently under consideration in Washington and we ------- OATE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY September 21, 1983 . SUBJECT Recommended Alternate Concentration Li~its for the Gilson Road Site, Nashua, NE. F~OM Michael R. Deland, Regional Administrator EPA, Region I, Bostc~, MA -. TO Lee M. Thomas, Assistant Administrator for Solid Waste and Emergenc~ Response (WH-562-A) EPA, Washington, DC. Introduction. I. am recommending to you alternate concentration limits for the Gilson Road site, which I have determined to be compatible with the RCRA regulations described in the July 26, 1982 Federal Register Section 264.92 through 264.94. This determination should assist you in approving the Record of Decision dated September 22, 1983 currently awaiting your signature. Backc;round The Gilson Road hazardous waste site located in Nashua, New Hampshire has received remedial action under the Comprehensive Emergency Response, Compensation, and Liability Act (CERCLA) since November, 1981. EPA used CERCLA emergency funds to install a ground water interception and recirculation system. This system was operated until October, 1982 when a slurry wall was completed. The State of New Hampshire developed a remedial investigation and feasibi1i"ty study in January, 1982 and a s~pplemental study providing costs associated with various ground water treatment rates in July, 1982. A Record of Decision was signed by the AA, OSWER in July, 1982 which approved the installation of the slurry wall and pilot studies. Upon completion of the slurry wall, a pilot treatment plant was constructed and operated for several months. The data from this pilot study resu~ted in a recommendation to construct a treatment plant capable of removin9.~0% of the hazardous constituents within the slurry wall. This design was based on evaluating the present and potential hazards to human health and environmental targets previously identified in the risk assessment portion of the feasibility study and supplement. A subsequent design modified to reduce operation and maintenance costs, but still capable of 90% removal is presently the subject of a Record of Decison dated September 22, 1983 awaiting signature by the AA OSWER. A briefing for the Director OSWER prior to the briefing for the AA OSWER su~faced the issue that a CERCLA financed ground-water treatment system should significantly reduce the level of ground-water contamination and in conjuction with the containment structure should be compatible with RCRA regulations g~verning ground water protection. ------- -2- Present Situation At this site, there are 16 hazardous constituents in the ground- water which are identified in Appendix VIII of RCRA Part .261. These hazardous constituents will be treated by the treatment process and reduced in concentration by an order of magnitude. (See Table 1). For these hazardous constituents, I am recommending the a~t~rnate concentration limits set forth in Table 1. These alternate concentration limits are consistent with the treatment design rationale which was set forth in the Feasibility Study of May, 1982 and approved in a subsequent Record of decision. These A.C.~.'~ were derived from extensive technical research into the potential hazard posed by such concentrations to the human population at risk (residents a~ two adjacent mobile home parks) and to environmental targets identified during the risk assessment, namely Lyle Reed Brook and the Nashua River. The documents which contain the technical rationale for establishing these limits and the equivalant requirements as specified in 264.94. of the RCRA regulations are enumerated in Appendix A. Public Participation The NH Water Supply and Pollution Control Association actively solicited public participation and input into the decision process in establishing the alternate concentration limits. Two formal meetings were held: one in March, 1982 and another in August, 1982 to present the findings of the remedial investigation and "feasibility study and to describe the various treatment schemes and results of the pilot plant study. The public reaction to the proposed treatment scheme was highly favorable including public acceptance of the long term effect of the contaminant containment and treatment. In addition, the public was made aware of all pertinent issues and the progress of remedial action through press releases, press conferences, and various mailings. At this time" the public is urging rapid implementation of the chosen alternative. Recommendation I am recommending that these site specific alternate concentration limits set forth in this memo be accepted as compatible with the RCRA regulations and guidance governing ground water protection. These limits represent a conservative evaluation of the concentration of contaminants which may remain within the slurry wall after treatment. In actuality, the slurry wall is expected to achieve 30 to 70% reduction after treatment. The contaminants which may leave containment would leave from the lower portion of the aquifer and this will provide additional attenuation to protect ~yle Reed Brook. Alternate water supplies have been provided to the human population at risk, and the assimilative capacity of the Nashua River will further protect downstream users should the treated contaminants migrate downstream. All these safeguards further protect public health and the environment beyond the inherent protection derived from the treatment ------- . Table I Contaminated Concentration Within the Containment After Treatment Appendix VIII Hazardous Constituents - Vinyl Chloride Benzene Chloroform , 1,1,2 trichloroethane Tetrachloroe~hylene Trichloroethylene Methyl Ethyl Ketone Chlorobenzene Methylene Chloride Toluene 1,1 Dichloroethane trans-l,2-Dichloroethane 1,1,1 Trichloroethane' Methyl Methacrylate Selenium Phenols Recommended A.C.L. Within the Containment Structure 95 ug/l 340 ug/l 1505 ug/l 1. 7 ug/1 57 ug/l 1500 ug/1 8000 ug/l 110 ug/1 1:2250 ug/l 2900 ug/l 1. 5 ug/l 1800 ug/1 . 200 ug/l 350 ug/l 2.6 ug/l 400 ug/l ------- Appendix A RCRA Requirement in Developing A.C.L.'s The physical and chemical characteristics of the waste in the regulated unit, including its potential for , migration; The hydrogeologicar~haracceristics of che facility and sur~ounding land: The quanity of ground water and the direction of ground water flow; The p~oximity and wichdrawal rates of ground-users; The current and future uses of ground water in che area. '. " . The existing quality of g~ound water, icluding other ~ources of contamination and their cumulation impact on the g~ound-water quality; The potential fo~ health ~isks caused by human . . exposure to waste consltutents: The potential damage to wildlife, crops, vegatation, and physical structures casued by exposure to waste consituents: The persistance and permanence of che potential adverse effects of hydraulically-connected surface-water quality considering; The volume and physical and chemical characteristics of the waste i~ the regulated unit: The hydrogeological characteristics of the facility and surrounding land~ The quanity and quality of ground water, and the direction of ground water flow; The patterns of rainfall ~n the region~ The proximity of the regulated unit to surface waters: Technical Documentation (1)(2)(4) (1) (2) (1)(2)(4) (1)(2) (1)(2) (1)(2) (1)(2) (1)(2) (1)( 2) (1}(2)(4) (1)(2) (1)(2)(4) ( 2 ) ------- Appendix A Con t . RCRA Requirement in Develo~ina A.C.L.'s Technical Documentation The current and future uses of surface waters in the area and any water quality standards established for those surface waters~ (l) ( 2) The existing quality of surface water, including other sources of cantamina~ian and the cumulative impact of surface-water quality (1)(2) The potential health_~isk causesd by human exposure to waste-constituents; (1) (2) The potential damage to wildlife, crops. vegetation, and physical structures caused by exposure to waste constituents; (1)(2) The persistence and permanance of the potential adverse effects. (1) (2) Key Contained in the following Documents: 1. Remedial Investigation (GHR Report) 2. Final Report. Sylvester Hazardous Waste Dump site Containment and Cleanup. 3. Supplemental report to final report. 4. Gilson Road Hazardous W~ste site pilot plant treatment ------- |