On-Site Bioremediation at ScottLumber Under a Performance Contractby Bruce Morrison, RPM, Region VII

Scott Lumber in Missouri is one of the largest Superfundsites in the United States where bioremediation has beenemployed. EPA’s Region VII Emergency Planning andResponse Branch (EP&R) laid the groundwork well for theirchoice of bioremediation. EP&R suspected that indigenousmicrobes were present at the site that could possibly convertthe creosote contaminated soil into harmless compounds on-site. But concentration levelsof the creosote compounds were quite high. For example, creosote contamination revealedconcentrations of benzo-a-pyrene (BAP) as high as 260 parts per million (ppm), with totalconcentration levels of polynuclear aromatic hydrocarbons (PAHs) as high as 64,000 ppm.Any cleanup at the site had to protect the aquifer that is the primary source of drinkingwater for Alton, Missouri.

EPA established cleanup levels for the site at concentrations less than 14 ppm forBAP and 500 ppm for total PAHs. EP&R then conducted a literature search and taskedtheir Technical Assistance Team (TAT) to perform a treatability study, independent ofcleanup contractors, to determine the feasibility of bioremediation. Both the literature andthe treatabiity study indicated a strong potential for significant biodegradation of creosotecompounds and possible cost savings when compared to conventional off-site disposal.

EPA’s Emergency Response Contractor for Region VII subcontracted the services ofRemediation Technologies, Inc. (RETEC) to clean up the site using bioremediation. Thecontract agreement was written as a fixed-price, performance specification contract; that

(see Bioremediation, page 3)

Bioremediationfor Both Soiland GroundWater On-Site

W ithcontam-inantsknown to bebiodegrad-able andindigenousmicrobes on-site to do the biodegrading,the signs pointed toward bioremediationto clean up both soil and ground waterat the Champion International Super-fund Site in Libby, Montana. Over theyears, the major contaminants at thesite-creosote and polycyclic aromaticcompounds and pentachlorophenol fromformer wood preserving operations-had contaminated a number of soil areasand migrated into the upper aquifer. Awaste pit was also a source of ground-water contamination. ChampionInternational, Inc. and WoodwardClyde, Inc. of Denver conducted bench-scale laboratory studies and pilot-scalein situ bioremediation studies thatindicated that biodegradation in the soilwas occuring and could be furtherenhanced by bioremediation treatmenttechniques. They determined that theground water could be treated throughbioremediation as well. The full scalebioremediation remedial design andremedial action are in various stages ofimplementation. Most of the cleanupwork to date has focused on thecontaminated soil.

The remediation contractor did nothave to construct a special stockpilearea for the soils. Soils from thecontaminated areas scattered throughoutthe site are excavated and brought to thepre-existing waste pit. The pit serves asa staging area to pretreat the soils. Inthe pit, biodegradation is enhanced assoil is sprinkled with water and nutrientsto support the growth and activity ofbacteria. Further a tiller aerates andhomogenizes the soil, so that the soilconcentrations are relatively even whenplaced on the final land treatment area.

However, prior to being placed in

(see Soil and Ground Water, page 4)

SITE Subjects

On-Site Chemical Destructionof Organics with UltravioletRadiation and Oxidationby Norma M. LewisRisk Reduction Engineering Laboratory

A t a former drum recycling facility in San Jose, Califor-nia. EPA demonstrated an innovative ultraviolet (UV)radiation/oxidation technology to treat ground water contami-nated with volatile organic compounds (VOCs). SevenVOCs had been identified in the ground water, of whichtrichloroethylene (TCE), was the major contaminant. The ground wateralso contained dichloroethane (l,l-DCA) and 1.1.1-trichlorethane (l,l,l-TCA), which arerelatively difficult to oxidize. The UV radiation/oxidation technology, developed byUltrox International, chemically destroys organics in liquids including those VOCsdifficult to oxidize), with little or no harmful residuals from the process. During thetesting at the San Jose site, no VOCs were detected in the exhaust from the treatment unit.The efficiency of destruction rendered the ground water in compliance with NationalPollutant Discharge Elimination System (NPDES) standards at the 95% confidence level.

Essentially, the process uses a combination of UV radiation, ozone and hydrogenperoxide to oxidize organic compounds in water. The treatment system is comprised offour different treatment modules that are mounted on skids. The ozone generator moduleand hydrogen peroxide system feed into the UV radiation/oxidation reactor module. Theliquid to be treated (ground water in the case of the San Jose site) is fed into the UVradiation/oxidation reactor. The reactor is divided into six chambers. Each chambercontains ultraviolet lamps and a diffuser that uniformly bubbles and distributes the ozonegas from the ozone generator through the liquid The combination of the UV radiation,hydrogen peroxide and ozone chemically destroys the VOCs. Off-gassing ozone and anyremaining VOCs in the reactor go to the catalytic ozone decomposer unit on top of thereactor where they are destroyed. The system allows you to enhance the oxidation of theorganics according to the level of concentrations of the contaminants by adjustingparameters such as oxidant dose, UV radiation intensity and the pH level of the incominggroundwater.

You have the option of pumping ground water directly from the aquifer into thereactor or of storing the liquid above ground for subsequent feeding into the reactor. Atthe San Jose site, the ground water was pumped into storage tanks because the flow fromthe wells was insufficient to support enough volume of water for flow through the reactor.The water was stored in inflatable heavy plastic bladder tanks. The construction of theinflatable tanks allows them to be filled to capacity, so that VOCs do not have space inthe tank to off-gas into the air.

The Ultrox system achieved removal efficiencies as high as 90% for the total VOCs.The removal efficiency for TCE, the major contaminant at the site, was greater than 99percent, The maximum removal efficiencies for 1,1-DCA and l,l,l-TCA were about 65and 85 percent respectively.

Use of the UV radiation/oxidation process at the San Jose site was part of the EPASuperfund Innovative Technology Evaluation (SITE) program. Overall, this treatmenttechnology is intended to destroy dissolved organic contaminants, including chlorinatedhydrocarbons and aromatic compounds, that are present in wastewater or ground water

(see UV Radiation/Oxidation, page 4)

Chemical Warfare Defense Evolves IntoPortable GC/MS for Hazardous Waste Sites

By Stephen BilletsEnvironmental Monitoring Systems Laboratory, Las Vegas

Gas chromatography/mass spectrometry (GC/MS) is the EPA-recommendedmethod for the analysis of volatile organic compounds (VOCs) andsemivolatile organic compounds. Until recently, it was not feasible to bringa (GC/MS) instrument to a hazardous waste site because its size and weightmade it too cumbersome to handle. However, field-portable mass spec-trometers were developed for military use in the mid-1980s to detect residualchemical warfare agents and have now been applied to the analysis ofsamples at hazardous waste sites. The Superfund Innovative TechnologyEvaluation (SITE) program recently demonstrated a mobile mass spectrometrysystem, developed by Bruker Instruments, Inc., at two Superfund sites inRegion I: the Re-Solve, Inc., Site with PCB-laden soil and the WestboroughTownship Site with PAH-contaminated soil and VOCs in ground water. Testresults harbinger field portable GC/MS as a major field technology for the1990s.

The Bruker mobile environmental monitor (MEM) measures about 20” x 20” x30” and weighs about 500 pounds. It can be mounted on a four-wheel drive

continued on page 6

BIOPLUME II Prediction of Natural Bioremediationin Ground Water Saves $3 Million at Traverse City Site

By Joseph WilliamsRobert S. Kerr Environmental Research Laboratory, Ada

EPA’s Robert S. Kerr Environmental Research Laboratory (RSKERL) has developed BIOPLUME II, a two-dimensionalground water model that can help you determine whether or not natural biodegradation can effectively remediatedissolved hydrocarbons in ground water. BIOPLUME II was used at the U.S. Coast Guard air station at Traverse City,

continued on page 4

Field Portable X-Ray Fluorescence for Inorganic Analysis

By William H. EngelmannEnvironmental Monitoring Systems Laboratory, Las Vegas

X-ray fluorescence has been astandard laboratory method foryears and the recent availabilityof portable instruments nowallows this method to be takeninto the field for use at hazard-ous waste sites. Field-portableX-ray fluorescence (FPXRF) is asite screening procedure using asmall, portable instrument thatprovides a rapid turnaround,low-cost method for in situanalysis of inorganic contami-nants. The conventionalmethods of analyses in fixedlocation laboratories take from20-45 days while FPXRF takesabout three days and costs lessthan conventional laboratoryanalysis. The design of FPXRFprovides flexibility for twolevels of analysis: in situanalysis and hot spot screening.

FPXRF, while not strictlyequivalent to conventionallaboratory analyses, producesquantitative results because theFPXRF is calibrated based onlimited conventional laboratoryanalyses of soil samples fromthe site. The in situ analysis iscombined with a pre-surveyaerial photographic evaluationof the site, documented qualitycontrol and geostatisticalinterpretation to produceisopleth maps denoting concen-

tration levels for contaminants atvarious site locations. The com-plete procedure from pre-surveythrough the final report takes aboutsix weeks and costs between$25,000 and $50,000. FPXRF hasbeen used at a number of sites.

For “hot spot” screening, site-specific calibration samples are notused. Calibration is based onstandards taken from similar sites.The results are useful for detectingsurficial contaminant “hot spots”and merely indicate relativedifferences between measurementstaken at the site. This “hot spot”screening is the most basic surveyand generally takes less than aweek at a cost of approximately$10,000 to $20,000. However, it isonly a qualitative method and is notrecommended as a substitute for thecomplete procedure. “Hot spot”screening is most appropriatelyused for some emergency responsesituations.

Six elements have been successfullyanalyzed by EMSL-LV using FPXRF:arsenic, chromium, copper, iron,lead and zinc. Other EPA InorganicTarget Analyte List elements may bequantifiable with FPXRF whenappropriate standards and radioiso-tope sources are used. Also, costsare expected to significantlydecrease with the advent of the

automated locating and datalogging system due in early1991.

FPXRF has been used at variedsites, including battery plating,tannery and mining operationsand a lead smelter. Forexample, FPXRF measured zincat the Palmerton Zinc Site inPennsylvania; mercury at theOrrington Mercury Site inMaine; chromium at theVander Horst Site in New YorkState; lead in painting sludgewaste at Caldwell Trucking inNew Jersey and at a TonolliMetals mining site in theAppalachian Mountains ofPennsylvania; lead and arsenicat Halby Chemical in Dela-ware; and cadmium, zinc,chromium and lead at NewHampshire Plating.

Remedial Project Managers andOn Scene Coordinators cancontact a Regional contractorwith the necessary equipmentand expertise to perform anFPXRF survey. If specialassistance is needed, you cancontact the Technical SupportCenter at EMSL-LV for expertadvice. For more information,contact Ken Brown at EMSL-LVat FTS 545-2270 or 702-798-2270.

Multispectral Identification Techniques ImproveIdentification of Non-Target Analytes

By William T. Donaldson, Environmental Research Laboratory, Athens andMary Moorcones, Office of Solid Waste and Emergency Response

The EPA Athens EnvironmentalResearch Laboratory (AERL) canhelp you turn tentatively identi-fied and unknown compounds atyour sites into definitely identi-fied compounds! A researchteam at AERL is applying multi-spectral identification techniquesthat can identify, with a highdegree of confidence, most of theorganic chemicals for whichmass spectral information can beobtained. For the identificationof non-target analytes, thetechnique offers a markedimprovement over the currentlow resolution electron impactmass spectrum (Method 8270)used by Superfund contractlaboratories in their gas chro-matograph/mass spectrometryanalyses. Although Method8270 can provide reliable

identifications of the 234 compoundstargeted for detection at Superfundsites, it is only about 25% accuratefor identification of unknown com-pounds. Whereas the universe ofcompounds that Method 8270 canidentify accurately is constrained bythe fact that the computer library isgeared to the 234 target analytes,multispectral identification is drivenby the ability to piece together highlydefinitive pieces of information forthe full array of semivolatile com-pounds.

Here’s how it works. In addition tothe low resolution electron impactmass spectra that are produced byMethod 8270, the AERL multispectralidentification team develops addi-tional spectroscopic information,which is pieced together to reveal theidentities of the unknown com-

pounds. High resolutionchemical ionization mass spectratell the analyst the number ofatoms of each chemical elementin the compound and highresolution electron impact massspectra provide similar informa-tion for key fragments of themolecule. Infrared spectraindicate the presence of func-tional groups that are character-istic of compound types, such asaldehydes or ketones. Duringone recent study, the AERL teamidentified 63 of 70 non-targetcompounds in industrial waste-water samples.

AERL is eager to help Superfundsite managers. For more infor-mation, contact John Mc Guireat AERL at FTS-250-3185 or 404-546-31 85.

Rethinking Measurement Methods for Mobility of Heavy Metals

By David S. Brown, Environmental Research Laboratory, Athens andKevin Novo-Gradac, AScI Corporation

The EPA Athens EnvironmentalResearch Laboratory (AERL) hasseveral alternative ways todetermine the mobility ofmetals at Superfund sites thatovercome some of difficultiesof the often-used platinumelectrode probe method. The

alternatives measure the oxidation/reduction (redox) potential, Eh, as away of measuring mobility ofmetals. We will briefly discusssome of the problems posed withthe platinum electrode method andthen briefly describe severalalternatives.

While the platinum electrodeEh measurements are effectivein some idealized laboratorysystems, the measurements inthe field are often plagued byproblems and should be held

continued on page 4

BIOPLUME IIfrom page 1

Michigan where a spill ofaviation gasoline had contami-nated the shallow groundwater, BIOPLUME II, incombination with otherassessment techniques, indi-cated that natural processeswould destroy the contami-nated plume that had reachedthe residential area down-gradient before the CoastGuard could let a contract andget a pump-and-treat remedyinstalled. The special assess-ments used in combinationwith BIOPLUME II included ageochemical characterizationof the plume and microcosmstudies establishing thatmicrobial degradation of thecontaminants was taking place.

Prior to these assessments, theState of Michigan was going torequire, as a result of courtaction, that the Coast Guardinstall interdiction wells and apump-and-treat system.Indeed, the Coast Guard hadalready installed a series of theinterdiction wells down-gradient of the source area tocreate a hydraulic barrier tocontain the contaminantswithin the boundary of theCoast Guard base. However,the strength of the assessmentevidence convinced the Stateof Michigan that furtherremediation beyond interdic-tion wells was of no value andthus saved the Coast Guard anestimated $3 million in reme-diation costs.

BIOPLUME II simulates the trans-port of dissolved hydrocarbons inground water and the effect ofoxygen-limited biodegradation onthese contaminants. You can takethe information from BIOPLUME IIand use it with any graphicssoftware to produce contaminantplume, oxygen distribution andhead maps. This version ofBIOPLUME II is available for DOS-compatible computers.

You can also use BIOPLUME II as acomponent of RSKERL’s OASISParameter Estimation System, adecision support system developedon the Macintosh withHYPERCARD. A decision flow-chart component of OASIS enablesyou to evaluate whether or notbiorestoration is an appropriateremediation technique for yoursite. As part of OASIS, theBIOPLUME II component buildsdatasets through interactive“painting” of information on thecomputer screen. Another portionof the OASIS system, BIOGRAPH,allows the user to visualize thesize, growth and degradation overtime of the hydrocarbon plume.BIOGRAPH can also producemaps of the distribution of the headof the plume as well as aquiferoxygen concentration levels.

For more information onBIOPLUME II and on OASIS and itsother components (hydrogeologicand chemical databases,bioremediation flowchart, theDRASTIC system for evaluatingground water pollution potentialand reference library of informa-tion related to bioremediation), callJoe Williams at FTS-743-2246 or405-332-8800 at RSKERL in Ada.

Rethinkingfrom page 3

suspect. Frequently, lack ofredox equilibrium (often thecase at Superfund sites) orcontamination of the electrodesurfaces by trace oxide coatingscan yield erroneous readings.The presence of trace oxidecoatings on the platinumsurface causes the electrodesystem to respond like a newtype of pH measurementdevice, rather than an indicatorof Eh. (A linear relationshipbetween measured pH andapparent Eh is a pretty goodindication that the oxide coatingproblem is present.)

In spite of the difficultiesassociated with determiningredox conditions at Superfundsites, the issue must not beneglected because of the criticalimportance of the redox state ininfluencing metals transport.The determination of Eh canmake the all-or-nothingdifference in mobility. Betteroptions for evaluating Eh(described in more detail below)involve direct measurement ofion activity ratio, measurementsof dissolved oxygen, detectionof sulfides or a method involv-ing iron solubility assumption.

Direct measurement of ion ratioactivity provides an estimate ofEh—it determines the ratio ofdifferent forms of the species ofthe same metal as a way to

continued on page 6

Quick Measurement and On-site Data Analysis ofOff-Gassing Air Emissions of Volatile Organics

By Donald F. GurkaEnvironmental Monitoring Systems Laboratory, Las Vegas

If you want quick on-site dataon air emissions of volatileorganic compounds (VOC) thatare off-gassing from soil andother sources at a site, youwant to know about open pathFT-IR (Fourier-transforminfrared) spectrometry. WithFT-IR you can reduce thenumber of points in the sitewhere you need to collectsamples in cannisters forlaboratory analysis--and fewercannister sampling points alsotranslates into lower costs. FT-IR rapidly scans the site aboveground over a path of up toseveral hundred meters toquickly narrow down thosepoints in the site from whichyou will need to take specificsoil or other samples for furtheranalysis.

The open path FT-IR consists oftwo devices on tripods. Thefirst device emits horizontalbeams of infrared radiationacross the path between thetwo devices. VOCs that areoffgassing within the pathabsorb energy from the beam.This process enables thesecond device to record anyVOCs in the path that haveconcentrations at the low partsper billion or higher level. Thesecond device then records the

average concentration of theseVOCs in the path over a set periodof time. Conversely, the cannistersampling method collects gasesonly at specific points. Anotherimportant advantage of FT-IR is thatyou can analyze the data on-site.Within a few hours, the fieldscientists can narrow down thosepoints in the site where you need tocollect samples for more extensivelaboratory analysis. The currentmobile instrument can be set upquickly at a site by trained person-nel and can function with minimumoperator intervention until thesystem is moved to a new locationon the site.

EPA has two efforts focusing ontesting, evaluation and applicationof FT-IR. Dr. Donald F. Gurka ofEPA’s Environmental MonitoringSystems Laboratory at Las Vegas(EMSL-LV), along with Region 7personnel, formed a cooperativeagreement with researchers atKansas State University to investi-gate the application of a prototypeopen path FT-IR at Superfund sites.For example, open path FT-IR wassuccessfully used at the HastingsNPL Superfund site in Region 7.Also, Dr. William McClenny ofEPA’s Atmospheric Research andExposure Assessment Laboratory(AREAL) at Research Triangle Park,North Carolina, is working with a

commercially available FT-IRsystem to demonstrate itsapplication at Superfund sites,such as the Hal by Chemicalsite in Delaware and theShavers Farm site in Georgia.Several open path FT-IRsystems will be demonstratedunder the Monitoring andMeasurement Technologiesportion of the SuperfundInnovative Technology Evalua-tion (SITE) Program in thespring of 1991.

Early assessments of thetechnology indicate that it is animportant tool for VOCscreening at hazardous wastesites. Preliminary data withabout 25 common volatilesolvents show that FT-IR candetect VOCs in the low partsper billion range. The technol-ogy promises to reduce thelabor and time involved intraditional NPL site studies andin the monitoring of off-gassingduring site remediations.

For further information onopen path FT-IR, contacteither: (1) EMSL-LV’s TechnicalSupport Center Manager, KenBrown, at FTS-545-2270, or702-798-2270 or (2) AREAL’sBill McClenny at FFS-629-3158 or 919-541-3158.

Chemical Warfarefrom page 1

vehicle and taken directly to thesite. This rugged instrument isequipped with built-in powersupply, is resistant to shocksand is independent of coolingand heating needs. It canoperate for six to eight hours onbuilt-in battery power.

You can choose from severalanalysis modes and sampleintroduction methods, based ondata quality objectives at yoursite. Two of these modes,“rapid screening” and “charac-terization,” were tested in theSITE demonstration. The rapidscreening mode al lows a quickanalysis for up to ten organiccompounds simultaneously.

The more accurate characterizationmode follows a Contract LaboratoryProcedure-type protocol. The massspectrum generated by this instru-ment is compared against knowncompounds in the computer’slibrary providing you with aninstantaneous analysis of yoursample.

The desirability of field-portableGC/MS instrumentation is obvious.The MEM provides the Agency withan instrument for field analysis withno compromise in methodology.The MEM affords the site manageraccess to the same quality of dataas a conventional laboratory GC/MS. Unanticipated field problemscan be quickly surmounted as theGC/MS measures for the full rangeof organic contaminants. Further,decisions can be made at the site,based on early results, to focussubsequent sampling in areas of

greatest contamination. Thus,fewer samples need to be sentto the laboratory for analysis.

The MEM enhances riskcommunication and manage-ment by allowing field scien-tists and decisionmakers tocompare field results tohistorical databases with rapidturnaround.

The MEM is commerciallyavailable. Additionally, asother mobile massspectrometery instrumentsbecome available, EMSL-LVwill perform comparisons andprovide further information.

For more information, callStephen Billets at EMSL-LV atFTS-545-2232 or 702-798-2232.

Rethinkingfrom page 4

determine Eh. The ratio of Fe(II)to Fe(III) is a good example sinceFe is present in all soil andground water.

The determination of dissolvedoxygen (DO) is a relatively easymeasurement that is amenable tofield implementation. Care mustbe taken to assure that oxygen isnot introduced during thesampling process or it willchange the Eh.

If sulfides are detected, you cansafely assume that most pollutant

metals of interest will be in theirreduced state, and hence havereduced mobility. Dissolved phasemetal concentrations will also be verylow.

The iron solubility assumptionmethod for estimating Eh is a crudebut simple estimate to use if analyti-cal or budget constraints prohibitother approaches. This measurementcan yield a rough redox estimate insystems of moderate to high pH.

A precise quantitative measure of Ehmay not always be necessary to makea reasoned decision about the poten-tial mobility of a particular metal at aparticular site. Often, a rough esti-mate will suffice for making somedeterminations about metals transport

from a particular site if usedskillfully and appropriately. Theoptions presented here allow youto make such determinations.

The focus of this article has beento introduce you to alternativeways to estimate redox condi-tions and ultimately the mobilityof metals. It is not intended togive you an in-depth knowledgeof the methods or the limitationsof the methods. The EPA AthensEnvironmental Research Labora-tory can help you with furtherinformation and in determiningwhich method is appropriate foryour site.

For further information, callDave Brown at AERL at FTS-250-3310 or 404-546-3310.

First Time User Hooked on ATTIC While ResearchingThermal Incinerationby Bill Sproat, Alternative Treatment Technology Information Center

M ike Scott with the Minnesota Pollution Control Agency was coordinating with the U.S. Army Corps of Engineers on a state leadsite when he decided EPA’s Alternative Treatment Technology Information Center (ATTIC) Database might be a good source ofinformation on thermal technology. The State of Minnesota and the Corps knew that the soil and ground water were contaminated withsemivolatile and volatile organic compounds. The Corps had already conducted treatability studies at the site and was leaning toward theuse of thermal incineration to clean up the site. However, they needed additional information on thermal treatment technologies versusbioremediation. They also needed a list of incinerator vendors.

Scott had heard about ATTIC from a colleague.Scott was able to respond to the Corps’ needs by accessing ATTIC.

He contacted the ATTIC system operator and explained that he needed to have athorough understanding of both bioremediation and thermal treatment, including performance levels and limitations. The subsequentsearch of the ATTIC Database yielded 14 abstracts, including three Records of Decision and two treatability studies related to thermaldestruction and bioremediation. The abstracts proved helpful and led Scott to contact ATTIC again for specific additional informationthat enabled him to compile a report for the Corps that contained a list of incinerator vendors and compared the cost and efficiency ofthermal destruction versus bioremediation.

Scott was also interested in determining what offices within EPA were involved in thermal treatment of hazardous wastes, includingEPA’s Combustion Research Facility. He was particularly interested in what the Superfund Innovative Technology Evaluation (SITE)Program had on innovative thermal technologies. Based on this request, an additional search of ATTIC specifically focused on SITEProgram thermal technology demonstrations, including the demonstration test performed by American Combustion’s Pyretron ThermalDestruction System at the Combustion Research Facility in Jefferson, Arkansas.

The Corps was not the only benefactor of Scott’s new addiction to ATTIC.conducting research on lead treatment

Scott was able to help a university researcher who isWhen the researcher contacted Scott for information on alternative treatment for lead contaminat-

ed soil, Scott was ready with ATTIC abstracts to send to the grateful researcher.Currently, almost 20% of the documents contained& the ATTIC Database include information on some form of thermal treatment

technologies. Several types of thermal processes highlighted in the ATTIC Database include rotary kiln incineration, fluidized bedcombustion, infrared incineration, pyrolysis and plasma heat systems.

For more information on how to use ATTIC, as well as information contained in ATTIC, do what Mike Scott did-call the ATTICoperator at 301-816-9153. Bill Sproat and his staff are ready to assist you.

Bioremediation(from page 1)

is, RETEC cannot receive paymentunless: (1) it completes the cleanupwithin 30 months, and (2) analytical dataconfirm that the contaminant concentra-tions are at or below the EPA establishedcleanup criteria for the site.

To prepare the soil for bioremedia-tion, several steps were taken. First, allidentified creosote-contaminated soil wasexcavated and stockpiled in an area thathad a high-density polyethylene (HPDE)cover overlying a crushed limestone base.The excavated area was then prepared asa land farm treatment cell for the soil.The cell area was contoured and itsperimeter bermed, i.e., built up to avoidrunoff. The base of the treatment cellwas compacted and layered with two feetof densely compacted clay to prevent thecontaminants from percolating into the

ground water. Next, an underdrain systemconsisting of a ten-inch sand layer and aperforated pipe network was placed on theclay liner to collect irrigation and rain waterwithin the treatment cell. A two-inch layerof top soil was then placed on top of theunderdrain system to act as a bufferbetween the system and the top layer ofcontaminated soil.

The treatment cell was then ready foroperation. A nine-inch layer of contamin-ated soil was placed on top of the treatmentcell surface. Operation of the treatmentcell, begun in June 1990, primarily consistsof: (1) tilling and irrigating the soil tofacilitate the biodegradation and (2)removing the rocks. The rocks are pressurewashed and will remain on-site. The waterfrom the rock washing operation is incorpo-rated into the irrigation system of thetreatment cell. The underdrain systemtransports the water to an HPDE-linedholding basin, where it is either recirculated

onto the treatment cell or pumped to thelocal publicly owned treatment works,

To date, approximately 60% of theexcavated soil (9,200 tons) has beenplaced in the treatment cell. EPA hasdone some preliminary testing on 17PAHs in a 6,000 square foot segment ofthe seven acre treatment cell. Resultsfrom this preliminary testing indicate thatbiodegradation is occurring at the &siredrate of cleanup. As of September 20,1990, the contaminant levels of soil havebeen reduced to 160 ppm for PAHs, with13 ppm for BAP. Costs are runningabout $75 per ton for bioremediation asopposed to $100 per ton for off-sitedisposal. And, you will get to see it onvideo. EPA has approved the productionof a videotape to document the project’sprogression.

For more information on the site,contact Bruce Morrison at FTS-757-3881or 913-236-388l