The Development of Chemical-Specific, Risk-Based Soil Cleanup Guidelines Results in Timely and Cost-Effective Remediation

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1 Journl of Soil Contmintion, 5(1):(1996) The Development of Chemicl-Specific, Risk-Bsed Soil Clenup Guidelines Results in Timely nd Cost-Effective Remedition John F. Liptk nd George Lomrdo New Hmpshire Deprtment of Environmentl Services, Concord, NH ABSTRACT: Millions of dollrs of limited stte clenup funds re spent ech yer in New Hmpshire to identify, smple, excvte, nd tret thousnds of tons of contminted soil. Cost nlyses of numerous sites indicted tht soil remedition costs lone rech upwrds of $300, per site. The New Hmpshire Deprtment of Environmentl Services Interim Policy for Mngement of Soils Contminted from Spills/Releses of Virgin Petroleum Products (DES, 1989, 1991) set conservtive remedition gols sed on totl petroleum hydrocrons in 1989 using the Leching Potentil Anlysis method (Cliforni Luft Mnul, 1989). A current review of ville literture nd severl cse histories indicted tht chemicl-specific soil clenup levels my e more pproprite for estlishing remedil gols. New chemicl-specific soil clenup guidelines using risk-sed pproch hve een developed. These new guidelines re conservtively sed using two principl considertions: (1) n ssumed soil exposure scenrio tht estimted the humn helth risks ssocited with potentil long-term exposure to site soils vi ingestion, inhltion nd derml contct nd (2) the estimted fte nd trnsport of chemicls of concern in the soil unsturted zone. The first considertion ssumed totl cncer risk tht did not exceed The second considertion employed the use of the SEsonl SOIL Comprtment (SESOIL) model which simultneously models wter trnsport, sediment trnsport, nd pollutnt fte (US EPA, 1981). Severl stte soil stndrds from Oregon, Wisconsin, Msschusetts, nd other sttes were extensively reviewed in order to develop level of confidence tht use of the SESOIL model ws pproprite. A series of sensitivity nlyses ws lso performed in order to evlute the response of the model to chnges in vrious input prmeters unique to New Hmpshire s hydrogeologic conditions. Generic soil clenup guidelines were developed for 24 petroleum-sed voltile nd semivoltile chemicls of concern to e pplied sttewide. Site-specific soil clenup guidelines will e llowed if it cn e demonstrted tht insertion of site-specific dt into the model will not dversely ffect groundwter qulity. As result of the ove processes, timely nd much more cost-effective remedition will e chieved while still mintining high degree of protection of the groundwter qulity nd humn helth. KEY WORDS: risk-sed soil clenup guidelines, totl petroleum hydrocrons (TPH), SESOIL, sensitivity nlyses, site-specific, cost effective remedition. Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 1

2 I. INTRODUCTION The New Hmpshire Deprtment of Environmentl Services (NHDES) developed chemicl-specific, risk-sed soil clenup guidelines tht ecme effective on Jnury 1, This rticle descries the process of tht development. The cost effectiveness nd protectiveness of this type of pproch towrd nswering the question How clen is clen?, is exmined. A summry of dt from severl petroleum-contminted sites tht represents the potentil cost svings relized if the chemicl-specific, risk-sed soil clenup guidelines were utilized in fvor of conservtive, indirect mesurements such s totl enzene, toluene, ethlyenzene, nd xylene (BTEX) nd totl petroleum hydrocrons (TPH) is lso discussed. A cse study is presented to further illustrte the differences in costs for the mngement of petroleum-contminted soils using the chemicl-specific, risk-sed soil clenup guidelines vs. numericl clenup guidelines for BTEX nd TPH. The cse study nd the dt summry re sed on ctul sites locted in New Hmpshire where corrective ctions hve een conducted under the New Hmpshire Leking Underground Storge Tnks (LUST) progrm. Millions of dollrs of limited stte clenup funds re spent ech yer in New Hmpshire to identify, smple, excvte, nd tret thousnds of tons of petroleumcontminted soil. Bsed on review of informtion collected from severl sites, cost nlysis indicted tht soil remedition costs lone represented n verge of $350, per site (Denison, 1994). The NHDES Interim Policy for the Mngement of Soils Contminted from Spills/Releses of Virgin Petroleum Products (policy) set conservtive remedil gols in 1989 using the leching potentil nlysis method (NHDES, 1989, 1991; CWRCB, 1988). These remedil gols, specificlly for BTEX constituents nd TPH compounds, hd ecome stndrd for mny sttes during the development of stte nd federl underground storge tnk (UST) progrms s method of guging when soil remedition ws complete t given site (Bell et l., 1990). The remedil gols for BTEX nd TPH mesured s gsoline were set t 1.0 nd 10.0 ppm, respectively. For fuel oils, the gols were set t 1.0 ppm for BTEX nd ppm for TPH. Recently, there hs een n incresed movement towrd chemicl-specific, risk-sed pproch to the clenup of petroleum-contminted soils. Since 1990, stte UST progrms hve moved wy from the typicl 1 ppm BTEX or 100 ppm TPH clenup stndrds or guidelines to more chemicl-specific, risk-sed pproches. Thirtytwo of 50 sttes hve mde this trnsition (Oliver et l., 1993). II. BTEX/TPH MEASUREMENTS VS. CHEMICAL-SPECIFIC MEASUREMENTS Trditionlly, BTEX constituents hve een comined together to determine the level of petroleum-relted voltile orgnic chemicls (VOC) t given site. How- Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 2

3 ever, this comprehensive method oscures whtever the rel risk would e to humn helth nd the environment. Moreover, BTEX constituents, the min components of gsoline tht re often nlyzed ecuse of their toxicity, re esily decomposed in the environment. BTEX is mesured in the lortory ginst gsoline stndrd. Becuse of its forementioned ffinity towrd rpid decomposition, nlysis of the BTEX compounds in soil smple tht is composed of wethered gsoline would not e ppropritely ddressed y single clenup guideline for just BTEX compounds tht is sed on pure gsoline stndrd (Nicholson nd Boyce, 1993). Other voltile nd semivoltile constituents of gsoline exist for which n ssocited chemicl-specific, risk-sed clenup guideline hs een developed y NHDES. The TPH mesurement hs severl limittions. Chemicl mixtures present in given soil smple cn vry gretly from site to site. Therefore, the individul constituents of the hydrocron mixture would e difficult to ssess ecuse the TPH mesurement gives only the totl mount of hydrocrons present in the soil. As result, the mgnitude of risk from specific TPH concentrtion will vry from site to site nd e difficult to determine. Moreover, the chemicl compounds found in complex petroleum mixture cn degrde over time nd lter the composition, moility, nd toxicity of the initil mixture. This fctor cn result in wide rnge of TPH concentrtions etween soil smples, nd the results my not e comprle. III. CHEMICAL-SPECIFIC, RISK-BASED SOIL CLEANUP GUIDELINES: A SCIENTIFIC APPROACH TO THE COST-EFFECTIVE SITE CLEANUP OF CONTAMINATED SOILS Thirty-two sttes hve developed nd implemented site-specific, risk-sed soil clenup levels or guidelines, indicting n incresing scientific pproch towrd risk-sed methodology for the clenup of contminted sites (Bell et l., 1990; Oliver et l., 1993). New risk-sed guidnce hs een developed y the Americn Society for Testing nd Mterils (ASTM). The guidnce stndrd, ASTM Guide for Risk-Bsed Corrective Action t Petroleum Relese Sites, offers three-tiered pproch to incorporting risk ssessment into the corrective ction process. These methods nd others to chemicl-specific, risk-sed pproch to corrective ction help to support the direction NHDES took in the development of its soil clenup guidelines. The formtion of these guidelines nd their effect on the cost effectiveness of site remedition re discussed elow. A. Generic Soil Clenup Guidelines A literture review nd file review of NHDES petroleum-contminted sites were performed in order to develop list of chemicls ssocited with petroleum Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 3

4 hydrocron mixtures in contminted soil (Anderson, 1992; MDEP, 1993,; Mgee et l., 1992). Initilly, 50 chemicls commonly found in vrious hydrocron mixtures indictive of petroleum-contminted soil t LUST sites were proposed to e included in the estlishment of the chemicl-specific, risksed soil clenup guidelines. However, due to (1) lck of ccurte risk-sed exposure dt, (2) no ville drinking wter stndrds for severl chemicls, nd (3) infrequently detected petroleum-sed chemicls in contminted soil smples, the initil list of regulted contminnts ws reduced to 24 chemicls. The concentrtion in soil tht ws protective of humn helth nd the environment ws derived for ech compound for oth direct exposure nd leching to groundwter exposure pthwys. The direct exposure pthwy reviewed three routes of exposure: ingestion, inhltion nd derml contct. The lechility exposure pthwy exmined the trnsport of contminnts through the susurfce to the groundwter tht would e used s drinking wter supplies. The concentrtions for the two exposure pthwys were compred, nd the lowest of the two vlues ws used s the generic soil clenup levels listed in Tle 1. The development of the soil clenup guidelines sed on direct exposure nd lechility long with the formtion of TPH guideline re discussed elow. 1. Development of Direct Exposure-Bsed Soil Clenup Guidelines Risk-sed soil clenup guidelines hve een developed for oth crcinogens nd noncrcinogens nd re sed on residentil exposure scenrio, ssuming tht residents re exposed to the soil y oth derml contct nd incidentl ingestion routes. They re intended to e protective for children nd dults nd represent the mximum cceptle helth risk for n mient residentil exposure scenrio. For those chemicls (i.e., enzene) tht re nticipted to exert similr trget effects of toxicity vi ll routes of exposure, the vrious pthwys were comined to develop risk-sed soil concentrtion. For those chemicls tht exhiit different criticl trget effects from different routes of exposure, risk-sed levels were clculted seprtely for the derml contct/ incidentl ingestion route vs. the inhltion route, nd the most restrictive of these two vlues ws used for the direct exposure clenup level (Perlmn, 1994). These risk-sed concentrtions were clculted to correspond to trget risk of 1 in 1 million ( ) excess cncer risk over lifetime for individul chemicls s well s cumultive crcinogenic risk for given site, given tht the exposure to multiple crcinogens through multiple routes ws reviewed. Guidelines for noncrcinogens were developed sed on n estimted exposure incurred in young child. All ssumptions used in the development of the direct exposure-sed soil clenup guidelines re recorded in Tle 2. Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 4

5 TABLE 1 Virgin Petroleum-Contminted Soils Generic Clenup Guidelines Soil clenup Regulted Guidelines Exposure contminnts (ppm) pthwys Acenphthene 0.66 Benzene 0.2 Benzo()nthrcene 0.66 Benzo()pyrene 0.66 Benzo()fluornthene 0.66 Benzo(k)fluornthene 0.66 Chrysene 0.66 Dienzo(,h)nthrcene ,2-Dichloroethne 0.04 Ethylenzene 75 Fluornthene 0.66 Indeno(1,2,3-cd)pyrene 0.66 Isopropylenzene 23 MTBE 0.6 Nphthlene 3 2-Methylnphthlene 0.66 Toluene 75 Xylenes (Totl) 750 Totl Petroleum Hydrocrons 10,000 Totl Noncrcinogenic PAHs 7,800 Acenphthylene Anthrcene Benzo(g,h,i)perylene Fluorene Phennthrene Pyrene Concentrtion is sed on the direct exposure pthwy vi inhltion, ingestion, nd derml contct. Concentrtion is sed on the lechility to the groundwter exposure pthwy. 2. Development of Lechility-Bsed Soil Clenup Guidelines The nlysis of the lechte pthwy involved the use of computer models to model trnsport of the contminnt nd to estimte sfe levels of soil concentrtion for ech compound. Severl stte petroleum soil mngement progrms (Oregon, Wisconsin, nd Msschusetts) were reviewed extensively (Anderson, 1992; MDEP, 1993; Scott nd Hetrick, 1994). These stte progrms used two models to develop soil clenup levels. The SEsonl Soil Comprtment (SESOIL) model ws used to Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 5

6 TABLE 2 Assumptions Used in Developing Risk-Bsed Soil Clenup Guidelines Prmeter Assumptions Trget risk rnge Exposure scenrio Residentil Age group Body weight Surfce re Soil ingested Dys exposed (yers) (kg) (cm 2 ) (mg/d) (yerly) , , , Concentrtion is sed on the direct exposure pthwy vi inhltion, ingestion, nd derml contct. Concentrtion is sed on the lechility to the groundwter exposure pthwy. model the fte nd trnsport of contminnts through the unsturted zone down to the wter tle. Anlyticl model of trnsient 1-, 2-, nd 3-dimensionl wste trnsport in quifers (AT123D) ws used to simulte the mixing of contminnts in groundwter nd trnsport within the sturted zone.* A review of the nlyses of the models performed y other stte progrms nd nlysis of the models using conservtive ssumptions nd input prmeters specific to New Hmpshire resulted in the discovery tht the two most criticl prmeters controlling the fte nd trnsport of chemicls in n queous system were Henry s constnt (H) nd the orgnic cron prtition coefficient (K oc ). Henry s constnt mesures the ility of compound dissolved in wter to escpe into ir. The orgnic cron prtition coefficient mesures the tendency of compound dissolved in wter to sor onto soil. The chemicls H nd K oc were then used in n empiricl eqution to clculte the soil clenup levels for the lechte pthwy. This empiricl eqution, first developed y Anderson (1992), is s follows: Soil/Wter = K oc H (1) The resultnt soil/wter rtio reltes chemicl s K oc nd H vlues to the rtio etween the initil soil concentrtion for given chemicl nd the mximum concentrtion of tht chemicl predicted for the groundwter. Becuse the mximum concentrtion predicted for chemicl in the groundwter cn lso e viewed s tht chemicl s helth-sed sfe drinking wter stndrd, Eqution 1 cn e used to clculte soil clenup guidelines tht would e protective of the groundwter. This ws ccomplished y ssigning the mximum groundwter concentrtion in Eqution 1 to New Hmpshire mient groundwter qulity * SESOIL ws initilly prepred for the USEPA office of Toxic Sustnce y Arthur D. Little, Inc., of Cmridge, MA, in 1984 (Bonzounts nd Wgner, 1984). AT123D ws developed y Ok Ridge Ntionl Lortory in 1981 (Odencrntz et l., 1990). Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 6

7 stndrd (AGQS) nd the initil soil concentrtion in Eqution 1 to the soil clenup level prmeter. This produced the following eqution: Soil Clenup = (0.150 K oc H) Sfe Drinking Wter Guidelines Stndrd (2) As conducted y Anderson (1992), ten indictor compounds were simulted in the SESOIL model nd then multiple liner regression model ws developed relting the soil clenup guideline to K oc nd H to provide dditionl soil clenup guidelines for other chemicls of concern. NHDES concurred with this technique nd selected conservtive input prmeters representtive of site conditions in New Hmpshire, which re outlined in Tle 3. These input prmeters nd their ssocited vlues were selected ecuse they represented conservtive site conditions. For exmple, soil orgnic cron ws selected with vlue of 0.1%. The soil orgnic cron content of soil is the primry controlling fctor for the dsorption/retrdtion of orgnic compounds in soils. Incresed retrdtion of contminnt in the soil results in incresed contct time with iodegrding orgnisms nd llows for voltiliztion, which results in less of the contminnt reching groundwter. However, with soil orgnic cron content vlue set very low, it ws determined tht more of chemicl ws estimted to rech groundwter. Therefore, long with the other conservtive input prmeter vlues nd the use of the AT123D model, conservtive concentrtions for the lechte pthwy were produced. The concentrtions for the lechte pthwy represent the mximum concentrtion in soil tht would not cuse violtion of New Hmpshire s drinking wter stndrds. Site conditions used in the modeling reserch re illustrted on Figure 1. TABLE 3 Representtive Input Prmeters Used in the SESOIL Model Prmeter Vlue Permeility cm 2 Bulk density 1.5 g/cm 3 Porosity 0.3 Soil orgnic cron 0.1% Hydrulic conductivity 0.5 m/h Hydrulic grdient Longitudinl dispersivity 20 m Trnsverse dispersivity 2 m Verticl dispersivity 2 m Annul precipittion Concord dt Initil soil concentrtion 10 ppm Voltiliztion Vol. frction = 0.2 Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 7

8 FIGURE 1. Site conditions used for the modeling studies. 3. Development of Totl Petroleum Hydrocron Soil Clenup Guideline As previously mentioned in this rticle, the use of TPH mesurement s tool for ssisting in risk-sed pproch to site clenup hs limited vlue. Despite this Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 8

9 informtion, use of the TPH mesurement ws incorported into New Hmpshire s generic soil clenup guidelines for severl resons. Current ville soil smple dt were reviewed from numerous sites tht indicted it is often the cse tht individul chemicl-specific clenup guidelines re often not exceeded with corresponding higher TPH vlues. However, with greter concentrtion for the TPH mesurement, ojectionl odors re sometimes present. A clenup guideline of 10,000 ppm ws estlished to del with the possiility of ny ojectionl odor from the contminted soil. It should e noted tht soils hving TPH vlues in excess of 10,000 ppm cn strt to show free product droplets (Bickford, 1994). Furthermore, the TPH mesurement is good indictor of generl petroleum contmintion. An initil TPH nlysis indicting no contmintion cn eliminte the need for costly dditionl nlysis. In ddition, the option to remove ny contminted soil with high TPH concentrtion tht does not exceed the chemicl-specific clenup guidelines hs een mde ville for esthetic resons. IV. CASE STUDY Potentil cost svings were clculted s descried elow tht illustrte how cost effective the use of chemicl-specific, risk-sed clenup guidelines re. One selected cse study, n irport, is explored in detil. This site ws initilly operted s municipl irport since the 1930s. In the 1950s, it ws further developed into militry instlltion. Fifty 55,000-gl. UST tht held vition jet fuel (JP-4) exist t the site. In , severl UST nd ssocited lines were removed. VOC concentrtions mesured in 96 composite soil smples from the site did not exceed the new chemicl-specific, risk-sed guidelines. PAH concentrtions mesured in 23 out of 24 composite soil smples did not exceed the new chemiclspecific, risk-sed guidelines. The soil TPH concentrtions mesured rnged up to 1700 ppm t depths down to 16 ft. Polyromtic hydrocrons (PAH) nd VOC concentrtions mesured in four groundwter smples did not exceed drinking wter stndrds for New Hmpshire. In ddition, VOC nd PAH nlysis in groundwter from municipl well locted 2000 ft downgrdient from the contminted soil indicted no petroleum contmintion. Becuse the clenup ws initited when NHDES hd in plce the remedil gols developed in 1989, pproximtely 45,000 t of soil with TPH concentrtions greter thn 100 ppm ws removed nd disposed of t locl lndfill. V. DATA SUMMARY Severl typicl gsoline service sttion sites consisting of UST with cpcity rnging from 3000 to 6000 gl nd in opertion since the 1950s hd petroleum- Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 9

10 contminted soil removed due to corrective ction. The soil removed rnged up to 8000 tons. Soil TPH concentrtions mesured t the sites rnged etween 50 nd 1000 ppm in soil. The soil t these sites ws mnged under the remedil gols estlished in All soil ws thermlly treted off-site t n verge cost of up to $350, per site. The dt summry for these sites is shown in Tle 4. VI. DISCUSSION OF RESULTS For the cse study reviewed in this rticle, the remedil gols developed in 1989 of 100 ppm for TPH were shown to e overprotective when compred with chemicl-specific, risk-sed pproch to corrective ction. Groundwter ws not dversely impcted t the site or t municipl well locted 2000 ft downgrdient. On chemicl-specific sis, no VOC or PAH concentrtions mesured in the site soil exceeded the new chemicl-specific, risk-sed soil clenup guidelines except for one smple. As summrized in Tle 4, dt from severl sites indicte the potentil cost svings relized if chemicl-specific, risk-sed pproch hd een implemented t these sites. Contminted soil from these sites tht ws ultimtely thermlly treted t extremely high cost rnged upwrd to nerly 8000 t. If the soil from the militry instlltion descried in the cse study hd to e thermlly treted, the costs for this one site lone would hve exceeded $1 million. If the new chemiclspecific, risk-sed soil clenup guidelines were in effect t the time of tretment of the soil from these seven sites, over $2 million could hve een sved nd TABLE 4 Summry of Potentil or Actul Cost Svings from Mngement of Petroleum-Contminted Soils Potentil Tons of cost soil TPH rnge svings Site nme removed (ppm) (pprox.) A 1, $73,000 B 2, ,000 $143,000 C 3, $237,000 D 2, ,000 $150,000 E 6, $398,000 F 7, $516,000 Includes ll verge costs for excvtion, stockpiling, trnsporttion, tretment, nd ckfill. Smpling nd nlysis costs were not included ecuse these costs re incurred during the site investigtion phse. Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 10

11 remedition efforts could hve een focused on more significnt sources of humn helth or environmentl risk. VII. CONCLUSIONS The following recommendtions/oservtions re mde: 1. At lest 32 sttes hve implemented risk-sed pproch to the development of soil clenup guidelines. 2. The use of the totl BTEX mesurement of the most voltile constituents of petroleum will oscure the rel risk posed y these chemicls. Individul nlysis of ech selected voltile nd semivoltile chemicl is recommended. 3. The use of the TPH mesurement in risk-sed corrective ction hs limited vlue. Use of the TPH stndrd lone t sites my e sustntilly under- or overprotective, ut with chemicl-specific, risk-sed pproch more efficient distriution of limited clenup funds cn e chieved. 4. Chemicl-specific, risk-sed soil clenup guidelines derived from the use of fte nd trnsport models nd risk ssessment methods sed on conservtive criteri cn result in lower costs for petroleum-contminted soil clenups nd t the sme time e protective of humn helth nd the environment. This methodology cn lso demonstrte the negligile risk posed to potentil humn or environmentl exposure pthwys when risksed site clenup pproch is implemented. Therefore, remedition efforts cn focus on more significnt sources of humn helth or environmentl risk. 5. SESOIL nd AT123D re pproprite models for use in developing generic soil clenup guidelines tht re protective of humn helth nd the environment. ACKNOWLEDGMENTS We wish to cknowledge the ssistnce of the New Hmpshire Division of Pulic Helth Services, Bureu of Helth Risk Assessment, specificlly Gry Perlmn nd John Dreisig, in the development of the direct exposure guidelines. REFERENCES Anderson, M. R Development of Generic Soil Clenup Levels Bsed on Anlysis of the Lechte Pthwy. Oregon. Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 11

12 Bell, C. E., Kostecki, P. T., nd Clrese, E. J An updte on ntionl survey of stte regultory policy: clenup stndrds. In: Petroleum Contminted Soils, Vol. 3, pp (Kostecki, P. T. nd Clrese, E. J., Eds.) Chelse, MI, Lewis Pulictions. Bickford, P Personl communiction. Bonzounts, M. nd Wgner, J. M SESOIL. A Sesonl Soil Comprtment Model. Prepred for the U.S. Environmentl Protection Agency, Office of Toxic Sustnces. Arthur D. Little. CWRCB (Cliforni Wter Reserch Control Bord) LUFT Mnul: Guidelines for Site Assessment Clenup nd Underground Storge Tnk Closure. Cliforni Wter Reserch Control Bord, Leking Underground Fuel Tnk Tsk Force. Denison, T Personl communiction. Mgee, B. H., Brdley, L. J. M., Butler, E. L., Krs, A. J., nd Growski, J. S Risk-sed trget clenup levels for TPH in soils. Pper presented t the Seventh Annul Conference on Contminted Soils, Msschusetts. MDEP (Msschusetts Deprtment of Environmentl Protection) Development of Dilution/ Attenution Fctors (DAFs) for the Lechility-Bsed Soil Stndrds. MDEP (Msschusetts Deprtment of Environmentl Protection) Msschusetts Contingency Pln Site Investigtion Guide. MDEP (Msschusetts Deprtment of Environmentl Protection) Msschusetts Contingency Pln. NHDES (New Hmpshire Deprtment of Environmentl Services). 1989, Interim Policy for Mngement of Soils Contminted from Spills/Releses of Virgin Petroleum Products. New Hmpshire Deprtment of Environmentl Services. Multi Medi Soils Tsk Force. Nicholsen, T. C. nd Boyce, C. P Clenup stndrds for petroleum hydrocron. I. Review of methods nd recent developments. J. Soil Contm. 2(2), 109. Odencrntz, J. E., Frr, J. M., nd Roinson, C. E Trnsport model prmeter sensitivity for soil clenup level determintions using SESOIL nd AT123D in the context of the Cliforni Leking Underground Fuel Tnk Field Mnul. In: Proceedings of the Fifth Annul Conference on Hydrocron Contminted Soils, Amherst, MA, 319. Oliver, T., Kostecki, P. T., nd Clrese, E. J Stte summry of soil nd groundwter clenup stndrds. In: Anlysis Monitoring Remedition Soils, pp (Prker, S., Ed.) Michign, Group III Communictions, Inc. Perlmn, G. D Soil Remedition Stndrds for Petroleum Contminted Soils. New Hmpshire. Scott, S. J. nd Hetrick, D. M The New SESOIL User s Guide, Rev Copyright 1996, CRC Press, Inc. Files my e downloded for personl use only. Reproduction of this mteril without the consent of the pulisher is prohiited. 12