0 0 0 0 1 5 0

CKMHIU.M E M O R A N D U M

TO: Margaret Guerriero, USEPA - Region V

CO Beth O'Brien, MDNR-ERDPaul Boersma, CH2M HILL

FROM: Michael McCann, CH2M HILL

DATE: October 25, 1990

SUBJECT: SVE Case Studies

PROJECT: CVO65563.PP.PM

As per your request, I have put together a short compilation of SVE case study summariesidentifying projects completed in and around Michigan. The attached Table identifies six sitescompleted to date. Case summaries for two of these sites and two additional sites are alsoenclosed. A notice of clean closure signed by James Truchan of the MDNR is attached to the casesummary for the Kinross site.

I hope this information is helpful. If I can provide any further information concerning these sitesor other SVE case studies, please let me know.

SOIL VAPOR EXTRACTION PERFORMANCE

REFERENCE LOCATION

SOIL/GEOLOGYCONDUCTIVITY

(CM/3)PERIOD OFOPERATION

PERCENTREDUCTION OFCONTAMINANT

CONCENTRATION

Suparfund Sit*in PR

GrovaJand, MASITE Prog.

clayay-siltsilty-ctay

10-5 to 10-7

silty clay10-8 (Lab)

4 yaara

56d

>99% (Vapor)Ca/Oon Tatrachlonda

94% (Soil)Tricrtloroathan*

3«ilviaw, FL

Stavanavilla1, Ml

Dayton, OH

Kinroaa Corrac-tional Facility,

Kinroaa, Ml

claywysandday.ailty sand

Av.10-4mfxad Mila

find sand to fin*sand with silt

10-3 to 10-4

primarily tandaand grav*l withthin day strata

2.4 x 10*5to 4.7 x 10-7

^ ^ ^hornoganouB

Approx. 10-3

180 d 90% Total hydrocarbona<Vapor)>08% Banzan«<Vapor)

270d >90% (Vapor)>»% (Soil)

Tatrachloroatrwn*

217d >99% (Soil)Totuana-Xylan*AcatonaKatona*

90d >99% (Soil)>99% (Vapor)

1,1,1-thchtoroathan*

REFSCNCES:

A: Agralot (1985). Malot (1989)3: £PA (1969)C: Appi*gat«-4Y988)0: Payna (1988) (1989)E: Usiacki, Payna (1989)F: Usiacki, Payn* (1989)

rKINROSS REGIONAL CORRECTIONAL FACILITY

PROJECT LOCATION: KINROSS REGIONAL CORRECTIONAL FACILITYSAULT SAINT MARIE, MICHIGAN

CONTAMINANT: 1,1,1-TRICHLOROETHANE

SOIL CONCENTRATION: START: 3,720 ppbEND: < 10 ppb

SOIL VOLUME: 159,000 cubic yards

PROJECT DURATION: 90 DAYS

COST PER CUBIC YARD: < $10.00

BACKGROUND

Kinross, located in Chippewa County, is at the eastern end ofthe Upper Peninsula of Michigan. The Kinross moraine andassociated deposits form some of the major highlands in the area.Kinross was the site of the decommissioned Kincheloe Air Force Baseand was to be the site of the Kinross Regional CorrectionalFacility (KRCF). KRCF consists of the Chippewa Regional andTemporary and Hiawatha Regional facilities. For the State ofMichigan's Department of Management & Budget, the Office ofFacilities contracted Turner Construction Company to manage thedesign and construction of the prison complex.

Construction of the prison complex began in the summer of1988. Construction was halted when strong solvent odors weredetected during footer excavation at the Chippewa RegionalFacility. The threat of human exposure to unknown quantities andtypes of buried contaminants prompted the Michigan Department ofManagement and Budget (MDHB) to formulate a situation response.All construction in the immediate vicinity of the two housing unitsin this area (Buildings 500 and 1200) would remain idle until afield survey for contamination was conducted on the surface andsubsurface soils and the sita remediated to reduce the healththreat to construction personnel.

SITE INVESTIGATION

STS Consultants Ltd. began the initial survey in July of 1988concentrating on an area of approximately 80,000 square feet nearthe housing units. STS initially identified 1,l-dichloroethylene,chloroform, 1,1,l-trichloro«thane, 1,1,2-trichloro«thane andtetrachloroethylene at concentrations over 60 ug/Kg in the soil.

snwv/rs

A second set of samples were taken and analyzed the next week.This data also revealed VOC contaminant concentrations in the partsper billion range* Based on the results of the STS survey, iMWRCwas retained by the MDMB to collect additional data and prepare aremediation plan. Due to construction delay costs which couldpotentially exceed one million dollars a week, it was imperativethat MDMB implement a treatment program designed to remediate thesite and allow construction activity resumption at the site asquickly as possible.

The MWRI site assessment team constructed six soil borings,monitored VOC vapors associated with drill cuttings and soilsamples, and soil sampled at two locations for laboratory analysis.Soil samples were then sent to a laboratory for contaminantidentification and quantification by GC/MS analysis. The contractlaboratory reported concentrations of 1,l,1-Trichloroethane (TCA)up to 3,720 ug/L at 30 feet below surface. The emergencyinvestigation also showed concentrations increasing with depth.

GEOLOGY OF SITE

Geologically, the area is a general highland and bothbuildings are situated above a regional ground water divide. Thegeology consists of light-browir ta-browir medium-grained sand. down.to the water table at" approximately 57-feet. The- sand becomescoarser toward the western edge of the site. The soil is veryhomogeneous and extremely conductive both pneumatically andhydraulically. The ground water gradient on the north side ismoving toward the northeast and to the southwest on the south side.

VAPORTECH" OPERATIONBased on site survey results, Michigan Department of

Management & Budget retained MWRI to design and install itspatented VAPORTECH enhanced volatilization system. MWRI mobilizedon August 16, 1988 for w«llfield and air conduit networkconstruction and installation of one VAPORTECH1" pump station. MWRIinstalled 14 injection wells and six withdrawal wells to form atreatment cell containing approximately 159,000 cubic yards ofsoil. System operation started 17 days after MWRI began siteactivities.

MWRI's in-situ vapor extraction method operated forapproximately 90 days. Due to the geology and diffuse nature ofnon-point source contamination, the total mass of materialrecovered was relatively low. Off-gas was controlled by adsorptiononto granular activated carbon. During operation, MWRI collectedprocess air samples and analyzed them at its laboratory in Lansing,Michigan. Analysis of the off-gas samples showed concentrationsof 1,1,1 TCA and other chlorinated compounds with trace amounts -.naphthalene.

CLOSURE

In December 1988, MWRI drilled one confirmatory soil boringin the previous "hot" spot. Analysis of the samples revealed belowdetectable limits ("<I0 ug/Kg) of volatile organic compounds. MWRIproject personnel then met with the Michigan Department of NaturalResource (MDNR) Environmental Response Division (ERD) to determineprotocol for closure on the site. MWRI prepared a closure plan inaccordance with the Michigan DNR Waste Management Draft Guidelinesdated May, 1988 entitled "How Clean is Clean" for closuredetermination. Site closure was approved on January 13, 1989.

This decision was later modified by the Chief of the ERD whorequired more soil samples from random points to confirm soilcontaminant level. Upon approval of the workplan by the MDNR, 19soxli: samples were taken, front 18 randomized: surface locations.Laboratory analysis with "immediate turnaround",.was initiated forall samples. Analyses revealed that all- samples, taken,.within thetreatment area were less- than 10 ppb for target compounds. MWRIreceived a letter from the MDNR in May 1989 stating that noadditional remediation was necessary at this site.

diiv 2* • 3? 11: i 1 ... •- • a" -^TTx.

STATE OF MICHIGAN, " injJM, RCSOU4CU COMMHTIOII <£« j

40MAS J. AMOCRSON

GORDON C. CUrUI

o. STTWMIT UYCM JAMES J. St NCHAftO. Oovwnoro,v,o o. ouo DEPARTMENT OF NATURAL RESOURCES

T. UfcSONpa aox jooa

Mawn F. NAUS.

CERTIFICATE OF ACTING CHIEFMICHIGAN DEPARTMENT OF NATURAL RESOURCES

ENVIRONMENTAL RESPONSE DIVISION

I, James Truchan, Acting Chief, Michigan Department of Natur&iResources, Environmertt'aJ. Response Division, certify the following, all as ofthe date hereof:

That I have reviewed the section entitled "THE FACILITIES - ChippewaCorrectional Facilities" of the Preliainary Official Stateaent dated May 1,1939 and the Official Stateaent dated Hay 12, 1989, relating to the StateBuilding Authority 1989 Sevenue Bonds, Series I and* to the best of 07knowledge, the Stateaent* in the Preliminary Official Stateaent and in theOfficial Statement in that section, insofar aa they relate to (i) DNR'sreview of the Kincheloe Air Fore* Base or inclusion in the NationalPriorities List and (ii) the identification and reaoval of soil c on tan i na-tion fro* certain building site* and the surrounding area, are accuratestatements or suooaries of the natters therein set forth and fairly presentthe information purported to be shown in that section (insofar as it relatesto the subject oatter identified above), as of the date hereof, does notcontain any untrue or misleading Stateaent of a naterial fact and does notomit Co state my fact required to be stated therein or necessary to makethe statement made therein, in light of the circuastances under which theywere made, not aisleading.

Dated: May ,_f 1989

is Truchanr"*eting Chiefihigan Department of Natural

Resources,Environmental Response Division

. 92

the total cost of the Detroit Regional Prisons will be derivedset forth in the following table: .

Bond Proceeds, including investment incomeState Appropriations

Total Cost of Detroit Regional Prisons

S 89,000,00015.800.000

S1Q4.8QQ.QQQ

Funds obtained from Bond proceeds, Including investment income,without further State appropriations, is sufficient to construct a tenantadleFacility.

Chippewa Correctional Facilities

This project involves construction of three separate prisons whichw i l l comprise the Chippewa Correctional Facilities. Each of these prisons isdescribed below: .,,'

Chippewapri son

Regional Prisonsubstantially

The Chippewasimilar to

Regionaleach of

Prison is athe Detroit

Regional Prisons, designed to house approximately 612 male inmates

Construction of the Chippewa Regional Prison commenced in October.1987 and is estimated to be tenantable September l. 1989.Construction, as of May 1. 1989. was approximately 851 complete.

Chippewa Temporary Prison. The Chippewa Temporary Prison is afacilityprototypewhichIT designed to provide medium securityhousing, administrative, recreational. vocational and supportfacilities for approximately 540 male inmates.

HIawatha Temporary Pri son. The Hiawatha Temporary Pri soncontains the same housing, administrative, recreational, vocationaland support facilities as the Chippewa Temporary Prison, and isdesigned to provide a medium-security complex for approximately 640male inmates.

Construction ofcomplete and they are

the Chippewa and Hiawatha Temporary Prisons is.. r .., ... . .„ _ . tenantable for purposes of the related Lease.Consequently, upon delivery of the Bonds, the State1s obligation to makepartial Rental payments will commence. The State has made an appropriationfor partial Rental payments due with respect to the Chippewa and HiawathaTemporary Prisons for fiscal year 1988-89. In the event any Facility is usedfor a purpose other than nous 1ng pnsoners, the State remains ob1igated tomake Rental payments in accordance with the related Lease.

The Architects for the Chippewa Correctional Facilities are GiffelsAssociates. Inc., Southfitld. Michigan, Cain Associates. Kalamaroo. Michiganand Becfcett and Raeder. Inc., Ann Arbor. Michigan and the construction manageris Turner Construction Company, fixed-price contracts have been entered intoto provide a tenantable Facility.

- 12 -

f, g T'

The total cost of the Chippewa Correctional Facilities will bederived as set forth in the following table:

Bond Proceeds, including Investment income $52,300,000State Appropriations 8. 700. OOP

Total Cost of Chippewa Correctional Facilities Sfil .000. QQQ

Funds ob ta i ned from Bond proceeds . i nc 1 ud i ng 1 nves tment i ncome ,without further State appropriations, are sufficient co construct tenantableChippewa Correctional Facilities.

The former Kinchloe Air Force Base comprised over 6.000 acres andincludes the approximately 130 acres where the Chippewa Correctional Facilityis being located. During the excavation for construction of two prisonhousing units, an area of soils .contaminated wi th chlorinated solvents wasencountered within the southern portion of the Site. The Michigan Departmentof Management and BudgeT retained consultants to determine the extent of thecontamination and to implement a soil cleanup remedy. Soil contamination wasdocumented as deep as 55 feet and extended south as far as the prison propertyline. No groundwater monitoring wells were installed within the boundaries ofthe known soil contamination area.

The results of the cleanup were reviewed by the Michigan Departmentof Natural Resources (the "MDNR"). rh y tom*mf HatfnuyirintV«Tie»lag towi

iiilei'fcM '• I nf

ut^t^evffimftte^No investigation has been made by the MONR over the full

130 acres of prison property to determine the presence or absence of othersources of contamination. In the opinion of the MONR Environmental ResponseDivision, the data developed to date would not adversely affect the use of theChippewa Correctional Facilities for their intended purpose,

The water supply for the Facilities is provided by the KinrossTownship municipal water system. The water supply is regularly monitored bythe Michigan Department of Public Health to ensure that it meets public healthqua I ity standards.

Air-Force B«e, which includes the- Sf-te -is underfor eligibility on the- Syperfund National . Priorities - List,

e stab I Ished under the Comprehensive Environmental Response, Compensation andLiability Act of 1980. as amended by the Superfund Amendments and^authorization Act of 1986. Initial results of the screening site inspectionconducted in August, 1988 indicate that the potential exists for the formerKinchloe Air Force Base to ultimately qualify for inclusion on the NationalPriority List.

See "SECURITY FOR AND SOURCES OF PAYMENT OF THE BONDS - FactorsAffecting State Rental Obligation and Insurance Provisions" and "LITIGATION."

- 13 -

r i O V 26 ' a 9 1 3 J l 3 . . • " p . 3 3

MICHIGAN DEPARTMENT OF NATURAL RESOURCES

INTEROFFICE COMMUNICATION

April 14, 1989

TO: Thomas Sajcton, Assistant Executive Director, State BuildingAuthority, Department of Management and Budget

FROM: Janes G. Truchan, Acting Chief, Environmental ResponseDivision, Department of Natural Resources

SUBJECT: Chippewa Correctional Facility Descriptive Attachment

. /My staff has 'completed their review of the new soil borings and soilanalyses data-fran the Chippewa. Correctional Facility contaminatedsoil treatment area that was recently provided to us by yourconsultant. Based upon thi* review, the proposed attachment has beenmodified to reflect prevent conditions at the site and is enclosed.This narrative constitute* my position regarding the status ofcontamination at the Qxippewa Correctional Facility, and is based uponall information that ha* be«n made available for ourccc: Mr. Stewart Freeman, Assistant Attorney General

Mr. Delbert Hector, HDNRMs. ttinciy Koch, MCNR

3 'f ;*0

nav 26 '99 it* I* ' p. a *

The former Kinchloe Air Force Base comprised over 6,000 acres andincludes the approximately 130 acres where the Chippewa CorrectionalFacility is being located. During the excavation for construction oftwo prison housing units,, an area of soils contaminated withchlorinated .solvent*.waa encountered"within the southern portion ofthe property. The Michigan Department of Management and Budgetretained consultants to determine the extent'of the contamination andto implement a soil cleanup remedy. Soil contamination was documentedas deep as 55 feet and extended south as far as the prison propertyline. Additional soil contamination is likely to extend beyond thesouthern prison property line, but no soil borings or analyses weremade in that area. It is not known whether groundwater contaminationexists underneath the prison property. No groundwater monitoring wellswere uistalled within the the boundaries of the known soilcontamination area. Groundwater contamination does exist immediatelyoutside the prison property to the southeast. Sine* groundwater flowdirections are/not known, it cannot be established as to whether thiscontamination' underflows prison property or not.

The results of the cleanup ware reviewed by the Michigan Department ofNatural Resources. Th» IS confirmatory soil borings and analysestaken March 22-29, 1989, show that the approximately 1.3 acres ofknown trichloroetnane soil contamination located within the southernportion of the site has been cleaned up. However, these sane analysesindicate the contaminants toluene, methylene chloride and

f- dichloroethane are present in soils at the site, but at levels which• do not require further remediation within the treatment area. Since no

investigation has been made over the full 130 acres of prison propertyto determine presence or absence of other sources of contamination,only the 1.3 acrea of soil may be considered to be remediated. Therelatively hi«h level of toluene (450 ug/kg) outside the treatmentarea indicates that additional investigation/cleanup may benecessary. This cleanup does not address any other areas of potentialcontamination on the foraer Air Force Base, or the known groundwatercontamination immediately outside the site of the facility- Soilcontamination likely exists immediately south of the prison propertyline and the treatment area.

The water supply for the Facility is provided by the Kinross Townshipmunicipal water systea. The water supply is regularly monitored by theMichigan Department of Public Health to ensure that it meets publichealth quality standard*. The increased frequency of monitoring isbecause of the potential for contamination of the township wells fromthe former air force base.

The former Kinchloe Air Force Base, which includes the site, is underevaluation for elgibility on the Superfund National Priorities List,established under the Comprehensive Environmental Response,Compensation and Liability Act of 1980. as amended by the SuperfundAmendments and { authorization Act of 1986. Initial results of thescreening site inspection conducted in August. 1988 indicate that the

( potential exists for the site to ultimately qualify for inclusion onthe National Priority List.

CONFIDENTIAL CLIENT

PROJECT LOCATION:

CONTAMINANTS:

CONCENTRATION:

MILFORD, MICHIGAN

TRICHLOROETHYLENE , PERCHLOROETHYLENE

START:END: 10-ppb (TARGET)

SOIL VOLUME: 7,700 cubic yards

TREATMENT DURATION: SIX MONTHS

BACKGROUND

A hydraulic pump manufacturing facility is located in SoutheasternMichigan. The manufacturing plant had several areas whichpotentially could be the cause of the contamination found to b*present at the site. Two groundvater storage tank areas at thenorth and northeast end of the plant which had been used to storesolvents used in degreasing operations. Two abandoned dry wellsand one 1,000 gallon tank are located at the north end of the ofthe facility. In addition there is a 12,000 gallon waste oilcutting holding tank on the east side of the facility. Upon reviewof the completed hydrogeological investigation, the responsibleparty determined that the VAPORTECH4* system was the most feasibleand cost effective manner of in-situ remediation of the vadose zoneat the site.

SITE INVESTIGATION

The investigation at this site was performed in 1986 by a thirdparty consultant and consisted of three phases. The first phasewas to investigate the presence of organic contaminants at the siteand, if present to define the extent of their migration. Phase Iconsisted of a Soil Gas survey to accomplish this goal. Resultsof the SGS indicated that VOCs were present at two areas at thefacility. Solvents, including TCEr PERC, and 1,2 DCZ and to alesser extent, components of gasoline (BTEX) were found to bepresent both at the soil disposal site and near the main facility.To further define the migration of contamination, a Phase IIinvestigation was undertaken. Phase II consisted of theinstallation of six Monitor Wells in the upper portion of the firstaquifer. Water quality analytical results indicated groundwaterdegradation at 5-7 feet below the groundwater surface. Deeper

13

rwells yielded no evidence of aquifer contamination. In order todetermine the source and extent of the solvent contamination, aPhase III investigation was undertaken.

six additional monitor wells were installed. During constructionof the monitor wells, split spoon samples were collected at twofoot intervals down to 27 or 60 feet. Selected soil samples weresubmitted to a laboratory for analysis. Results of the analysesshowed that very low levels of organic contaminants were presentfrom the site surface to just above the water table (approximately24 feet). Contamination consisting of TCEr and PERC was found atvarious depths with levels between. CT and 8,900'ppb in soil samplesdowngradient of the 12,000 gallon holding tank, the abandoned drywell, the old underground storage tanks and extended in thedowngradient direction toward the south property line.

GEOLOGY

Hydrogeologic investigations completed during April of 1987determined that the depth, to groundwater ranges for approximately23>-27 feetr. The soils overlying the groundwater aquifer arepredominantly sands and would provide minimal protection frommovement of surface contaminants downward toward the groundwater.The aquifer material consists of sand with: & trac* at graveL andsilt from saturation to the top to clay aquitard approximately 60feet. Some clay stringers were found in the sand just above theclay base of the aquifer. The aquifer was found to be fine tocoarse sand with a trace of gravel between the 23 and 57 footdepths and silt from 57-60 feet* Clay till was encountered belowthe 60-foot depth. Direction of the groundwater flow for the firstaquifer is southeasterly with a gradient of 0.0015 feet/foot.

•TMVAPORTECH OPERATION

MWRI was retained in Hay 1989 by the client to provide VAPORTECH"system operation to remediate approximately 7,700 cubic yards ofvadosa zone soils at the northeast corner of the facility. MWRIdefined two treatment cells for remediation, one of the treatmentcells is bisected by a service drive for traffic. MWRI was ableto provide minimal disruption to the roadway by installingtreatment piping across the road beneath speed bumps. Because ofthe separation of contaminants in the defined soil strata, MWRIstratified it* air uptake points in order to promote air flowthrough the treatment cell. MWRI created "nested" air withdrawalstrata at five locations with the following vertical dimensions:

Strata 1 Grade level to 8*12*Strata 2 8-12 feet to 20-23*

14

Based on negotiations with the Michigan DNR, the contracted levelof remediation is Below Detection Levels (BDL - < 10 ppb) of TCE.MWRI configured the VAPORTECH*" system to pass off-gas throughactivated carbon to capture VOC laden air. The decontaminatedairstream is then re-injected into the treatment area. During thefirst nine days of operation, the system off-gas decreased from 70ppm TVOCs to 22 ppra. During the next 14 days the level of TVOCsdecreased to 5.7 ppm. As of September 25, 1989 off-gas levels ofcomposite samples were 1.3 ppm and thirty percent of the treatmentarea has been closed based on off-gas VOC concentrations forindividual wellheads being below detection level. To date MWRIcalculates that approximately 170 pounds of PERC and TCE had beenrecovered.

SYSTEM SHUT DOWN AND RE-START

Due to the observable reduction in process off-gas concentration,MWRI initiated a system shut-down and re-start program in October,1989. This procedure entails shutting the system down for 7-10days to allow the soil environment, to re-equilibrate totemperatures and pressures which existed prior to treatment. Th«vapor extraction process is then re-activated to its normaloperating parameters. Experience has shown that a "re-start yieldspike is usually encountered immediately after start-up whichquickly declines to contaminant levels that parallel those priorto shut down. Samples were taken at 60, minutes and. 120 minutesafter system start-up. Samples results indicated that* soil vaporcontaminant levels were-minimal or non detect, which prompted MWRIto initiate a post treatment soil boring program.

CLOSURE

In December 1989, MWRI drilled two confirmatory soil borings in theprevious "hot** spot. Analysis of eight samples revealed that sixof the eight samples were below detectable limits (<10 ug/kg) ofvolatile organic compounds and two samples were at 20 ppb and 30ppb,. respectively* MWRI has discontinued treatment and hassubmitted a draft report to the client for submission to the MDNRfor closure of the site.

15

FLEXIBLE PACKAGING MANUFACTURER

PROJECT LOCATION: EDINBURGH, INDIANA

CONTAMINANTS: TOLUENE

SOIL CONCENTRATION: START: >1,000,000 ppbEND: <10 ppb

SOIL VOLUME: 1,000 cubic yards

PROJECT DURATION: THREE MONTHS

BACKGROUND

This flexible packaging manufacturer produces various packages forthe food and medical industry. The manufacturing process requiresuse of various solvents, mainly toluene and ethyl acetate. Inearly 1989 a small spill of toluene occurred in the vicinity ofthe existing tank farm area. Initial visual observations estimatedthe spill to be less than 50 gallons. An Indiana basedenvironmental consulting firm was contracted to perform anassessment of the horizontal and vertical extent of contamination.Initial soil gas survey results completed in April- 1989, revealedthat soil- contaminant concentrations wera greater than. 1000 ppa-After review of the completed soil gas survey data, and review ofpotential remedial alternatives, the responsible party selectedMWRI to design and install a VAPORTECH* system, a patented vaporrecovery system for the in-situ removal of VOCs. Selection wasbased on MWRl's experience and economic advantages.

GEOLOGY

Geological materials underlying the facility consists ofunconsolidated materials of glacial origin. The facility lies ina general art* where sand and gravel outwash deposits are abundant.The geologicr cross section defined by subsurface shallow boringsreveal the presence of loess (silt) which ranges in thickness fromsix: inches to four; feet and overlies a reddish brown sandy pebblyloam which extends to a depth approximately seven feet below grade.Underlying the till, sand and gravel is encountered to theapproximated depth of 25 feet. The water table is present at about15-17 feet below grade and appears to move at a rate of . 002feet/day in a southerly direction.

19

gTTKIn September. of 1988 an Indiana environmental consulting firmundertook a groundwater investigation to detect potentialcontamination caused by releases from underground storage tanks.Four separate UST locations had been present at the time of theexcavation. At that time these had been excavated and contaminatedsoil stockpiled for appropriate management. Eight groundwatermonitoring wells were installed and samples were collected fromeach well. Samples were analyzed for a variety of organicconstituents of concern including toluene, lacolene, ethyl alcohol,n-propyl alcohol, n-propyl acetate and diesel fuel. Toluene anddiesel fuel were found to be present in some of the samples,indicating that the contents of some of the tanks had been lost.Subsequent to this investigation, a small toluene spill occurredwhich prompted the client to contract MWRI for remediation of thearea immediately impacted by the newest spill.

VAPORTECH" SYSTEM OPERATION

In June, 1989 MWRI began construction of a treatment cell,encompassing approximately 500 cubic yards at the site. The most:,critical area of contamination underwent treatment first.Additional contamination was determined to be present on theperimeter of the treatment parcel. In August, the treatment areawas expanded to incorporate an additional 500 cubic- yards. Allair handling piping was installed above grade. Withdrawal pipingwas connected to a 15 foot tall, six inch diameter dispersion stackfor discharge of off-gas to atmosphere. The site was covered withfour mil thick plastic sheeting and fill sand to act as animpermeable layer for air and water control.

Upon initial start-up of the system in June, the contaminantcomposite vapor concentration of toluene was in excess of 408 ppm.After two weeks of system operation, the composite concentrationhad been decreased to 57.3 ppm and a calculated 125 pounds oftoluene had been removed form the soil. This amount represented75 percent of the total yield of the entire project. After fourweeks of remediation, composite off-gas results were at 16.45 ppm.After eight weeks the composite concentration was reduced to 1.08ppm and the total yield of toluene for week eight was slightlygreater than one half a pound.

20

CLOSURE

In October 1989, MWRI installed four confirmatory soil borings todetermine if the toluene levels in the soils were below thetargeted 0.1 ppm. Three split spoon samples were taken from eachborehole. Samples were taken at random depths in each borehole toavoid sampling bias™.. Analysis;dCfaUrtwelve samples, form: tolueneshowedi nom detect, results- (less:- thanr l(T ppb) . This levelrepresents closure levels t»n«,times-= less--than established; targetlevels. MWRI has discontinued™treatment of "Cell A" and is nowtreating an additional parcel incorporating approximately 1,200cubic yards at the site. */*w

21

SHERWIN WILLIAMS

PROJECT LOCATION: DAYTON, OHIO

CONTAMINANTS: ACETONE, MIBK, MEK, TOLUENE, BENZENE, XYLENE,ETHYL BENZENE, ALKANES, ALKENES, ALCOHOLS Ai-Ji;MINERAL SPIRITS

SOIL CONCENTRATION: START: 38,000 ppb TVOCEND: < 40 ppb TVOC

SOIL VOLUME: 425,000 cubic yards

PROJECT DURATION: SIX MONTHS TO REACH FINAL SOIL CONCENTRATIONS

COST PER CUBIC YARD: < $10.00

BACKGROUND

An undetermined quantity of paints and paint solvents werelost to soils at a paint warehouse in Dayton, Ohio during acatastrophic fire in the spring of 1987. The warehouse had aninventory estimated at 1.5 million gallons of paint, paint thinnersand associated products. Fire fighters did not use water to fightthe fire because it would have transported volatile organiccompound (VOC) constituents downward, by bulk movement or insolution. Uncombusted material penetrated the so il and spreadthrough the unsaturated zone despite this tactic. VOCs weredetected in nearby city wells within six weeks after the fire.

SITE INVESTIGATION

The paint component stock in the former warehouse containedmany volatile organic compounds. The major VOC types includedacetone, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK),benzene, ethyl benzene, toluene, naphtha, xylena and other volatilealiphatic and alkyl-benzene compounds. In all, more than 45different VOCs were identified in soil gas samples. Soil sampleswere taken by means of split spoon sampling during monitor well,ground water recovery well and vapor extraction system installationand unsaturated zone characterization.

snrrsrs

Total VOC concentrations were highest along the south and westsides of the warehouse floor outside the foundation, where totalVOC concentrations exceeded 10,000 ppm in the soil. Over much ofthe site, VOC levels were between 1 and 10 ppm. Contaminant levelswere highest in the upper 10 feet of the unsaturated zone,partially due to the presence of the discontinuous clays andperched water zones.

These high concentrations in the vadose zone pose as a threato f ground water contamination. Recharge waters can transportdissolved vocs down to the water table during the recharge seasonand following heavy storms. This would be particularly importantat this site, where much of tha contaminant load is accounted forby the highly soluble ketones, namely acetone, MEK and MIBK.Without removal of the VOCs from the vadose zone, the ground waterwould remain at risk.

Residual VOCs in the vadose zone may also solubilize intounderlying ground water by two vapor-phase transport mechanisms,where there are high concentrations at or above the capillaryfringe, diffusive migration can lead to mobilization into groundwater. Soil gas containing VOCs can also be displaced by saturatedfronts percolating through the vadose zone during heavyprecipitation events, bringing vapor-phase constituents intocontact with ground water. Given that the majority of lost paintconstituents were still adsorbed within the unsaturated zone, itwas imperative to remove this material before it could beremobilized to the ground water.

The maximum ground water VOC concentrations any time followingthe fire was 620 mg/1 of acetone. Ground water contamination waswidespread, as was the soil contamination, underlying more than 6acres of the outwash material.

GEOLOGY

The site is underlain entirely by valley-fill glacial outwashwithin the Great Miami River valley, reaching a thickness of over200 feet. The outwash is composed chiefly of coarse and clean sandand gravel, with numerous cobbles and small boulders. Two outwashunits are present, separated by a discontinuous till, found atdepths of 65 to 75 feet. The bedrock at this site is interbeddedwith Ordovician shale and limestone.

The upper outwash forms an unconfined aquifer, in whichsaturation occurs at a depth of 40 to 45 feet below grade. In theupper 10 feet of this unit, several discontinuous alluvial silt andclay strata are encountered, which support thin lenses of perched

water from a few inches to a few feet in thickness. The till belowserves as an aquitard between the unconfirmed outwash aquifer andthe lower confined to semi-confined outwash aquifer. Pump and slugtests in the upper aquifer have yielded measured values ofhydraulic conductivity ranging from 100 to 270 feet per day.

In the area along the Great Miami River, the ground water flowis toward the river. At this study site, however, the gradient inthe unconfined aquifer is towards the north, as the river suppliesa great deal of aquifer recharge induced by the pumping of the citymunicipal wells. This particular field serves 26 municipal and 5industrial wells, supplying approximately 30 percent of the city'swater supply.

VAPQRTECH" SYSTEM OPERATIONThe treatment area at the study site encompassed a total of

roughly 6 acres, including all soil underlying the formerwarehouse. Over the entire area, vacuum withdrawal extended to thedepth of ground water at about 40 to 45 feet for a total volumeof about 425,000 yd .

The treated soil volume was divided into four cells, based onthe air flow rate which could be provided by a VAPORTECH^ pumpingunit. Each of the four cells were brought on-line at two weeksintervals. The first cell containing 100,000 cubic yards was inoperation on July 22, 1987, two weeks after receipt ofauthorization from the client. The system yielded 3,720 poundstotal volatiles during th« first 73 days of operation. After 56weeks of operation, over 8000 pounds of volatile organics had beenrecovered from the site.

The principal volatile compounds yielded by the soil recoverysystem were:

AcetoneMethyl ethyl JcetoneMethyl isobutyl ketoneTolueneXylenes (ortho, meta, para)

These compounds account for approximately so percent ofmaterial recovered to date. The remaining material recovered wascomprised of mineral spirits, naptha and other diluters. GC/MSanalysis indicated that more than 85 compounds were yielded in thefirst 73 days of operation. All but the first seven compoundsnamed above fell below detectable levels in soil and ground watersamples.

CLOSURE

Prior to EV initialization at this site, there were nospecific closure criteria established for soil VOC concentrations.MWRI proposed that the appropriate remediation level should bedetermined by static soil atmosphere-aqueous (ground water)-phaseequilibrium conditions. The soil action levels should be low enoughso that waters recharging through contaminated soils result inground water VOC concentrations at or below regulatory standards.

Closure levels for the site were developed in a riskassessment during the fall months of 1987. The final versionestablished ground water" VOC action: levels- only. Levels were setfor the ketones only, and are listed below:

Action LevelParameter fua/Il

Acetone 810MIBK 260MEK 450

The risk assessment established no action levels for toluene;xylenes, ethyl benzene, or any of the many other types ofhydrocarbons identified in off-gases, because they had long sinceceased to be measurable in monitor and municipal well samples. Byearly February 1988 the only remaining detectable VOCs in eitherthe perched or unconfined water were those listed above. The actionlevels generated were accepted by the city and the OEPA inFebruary, 1988.

By April of 1988, composite off-gas VOC concentrations fromthe relatively deep unsaturatad interval (> 15 feet deep) in allcells had fallen to less than 1 ppm. At the same time, VOCconcentrations in the unconfined aquifer had for almost two monthsbeen at non-detectable levels for all hydrocarbon speciesidentified prior to treatment.

In April, the client petitioned the OEPA for at least partialsite closure based on off-gas and ground water VOC concentrations.Cells 1 and 2 were closed entirely. Only shallow treatmentcontinued in Cells 3 and 4, where elevated VOC levels remained inboth ground water and unsaturated soils above the clay and siltlenses which support the perched water.

Perched water quality was monitored beginning in February,1988 at the Cell 3 and 4 vacuum well head locations. Samples weregathered in a glass jar attached to a drop pipe located down-gradient of the vacuum well head. Once filled, a portion was thentransferred to a 40-ml vial for laboratory analysis.

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By June, 1988, all off-gases extracted from the shallowunsaturated soil were below l ppra. Jt£fiperched; water extracted fromthe same vacuum wells yieldadr.VOC concentrationff below the: actionlevelss-accaptedT by the-OBPA. At this point the site had met allclosure criteria.

Although all perched water was below the action levels, thecity and OEPA required that the client provide an extra measure ofVOC removal by further exposing the most shallow unsaturated soiland perched water to the atmosphere. In July, demolition of theformer warehouse floor began. As the concrete deck was brokenapart and removed, the underlying soil was disturbed to a depth oftwo to three feet, effectively land-farming the material in orderto volatilize additional remaining vocs.

The final closure steps required of the VAPORTECH1*installation are the grouting of all air injection/vacuum well andconduits. This took place in August and September of 1988.