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Declaration for the Record of

Fortst Waste DisposalOtlsville, Michigan

PURPOSE

"his decision document '•"presents the final selected remedial act'on *:.*tne, 'orest «aste Disposal s i t e in O t i s v i l l e , Micmgan. It *as :ave!;;eiaccordance with the Csmprenensive Environmental Response, Compensation, jn-l i a b i l i t y Act of 1980 (CcRCLA), as amended by the Suoerfund Amendments iia3eauthori:ation Act of 1986 (SARA), and to the extent practicaote, theNational Contingency Plan (40 CrR Part 300).

The State of Michigan has been consulted on the selected remedy and c:oosesthe remedy. - ,. -,-.-.__

BASIS

The selection of remedy is based upon the Forest Waste Disposal SiteAdministrative .Record. The attacned index identifies the items whichcomprise this record.

DESCRIPTIOM OF SELECTED REMEDY

The final ,-emedial action addresses two site operable units: the Vandal'soil and source materials, and contaminated groundwater on the east end ;ft " e site. " . , - - - -

The landfill operable unit remedial action consists of the following:

Removal and offsite treatment of areas of concentrated drumsand associated saturated contaminated soils;

Installation of a Resource Conservation and Recovery Act (RCRA)cap over tht landfill;

Installation of a soil-bentonite slurry wall vertical barrier witha dtMtfHng system surrounding the landfill;

Otltctlon and treatment of the groundwater from the dewateringi sy»t«»;

• Access restrictions on the Forest Wast* property and areasimmediately surrounding the site;

Installation of fence around the lancfill area; and

Groundwater monitoring around the landfill.

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oseraole u n i t cared' il a:t;on ::ns-$;s ;* "--s *:'':

i;:5ss -5stnct:3"s *hvcn •icl-.da prevention of -••I'-xi-g *a:e-- • e l l s 'i f.e snal'ow aquifsr :n :ne sita :r :n adjacent 3"eas;

ter -onitoring to assess the changes in location andconcentration of the contaminant plume.

DECLARATION

The selected remedy is protective of human health and tne environment,attains rederal and State requirements that are applicable or relevant andappropriate, and is cost-effective. As mandated by CERCLA and as amendedby SARA, the remedy satisfies the preference for treatment that reducestoxicity, mobility, or volume of hazardous substances as a principalelement. Finally, this remedy utilizes permanent solutions to the maximumextent practicaole.

Because this remedy w i l l result in hazardous substances remaining onsiteabove heal th-oased levels, a review w i l l be conducted every 5 /ears aftercommencement of '•emedial action to ensure that the remedy continues toprovide adequate protection of human health and tie environment.

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jat /aidas V. Ad4nuRegional Admini dU.S. EPA, Regi

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Suawry of Remedial Alternative SelectionForest Waste DisposalOtlsvllle. Michigan

SITE LQCATIOM AND DESCRIPTION

"he Forest ,^aste site is in :ne rural southeast corner of Sscf:n_3, r;,-?s:'ownsnip (T9N, R8E) , lenesee County, Micnigan. It is 20 n i l e s lor^sis: ;•Flint, and 2 miles nortnwest of t.ne City of C t i s v i l l e (Figure I). In 1322,the population within a 3-mile radius of the site was estimated it 3,120 :/the Micnigan Department of 'latural Resources (MONR). O t i s v i l l e had'anestimated population of 729. An estimated 20-30 households are within aquarter m i l a of the site.

The site is generally flat except for slight irregularities in the landsurface suggesting waste disposal. Vegetation consists of grass and weeds,low shrubs, and a few scattered trees. Land surrounding the site isapproximately 50 percent agricultural and 50 percent undeveloped (woodlandsand wetlands). Sutternut Creek flows past the southeast corner of thesite, continuing southwest and discharging into the Flint River.

Physical features of the site include * landfill and nine surfaceimpoundments, or lagoons, that were used for waste disposal. The landfillarea occupies approximately 11 acres of the 112-acrs property. It iscovered with vegetation and native soil, althougn refuse and rusty drumsare exposed in some places. The nine lagoons have a collective surfacearea of about i acre. A schematic site map is presented in Figure 2.

'he regional geography of Forest Township is typical of glaciated areas,characterized by morainal deposits. The topography of Forest Township ish i l l y in the east, grading to a slightly undulating and, in places, flatsurface in the west.

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The surficial geology in the vicinity of the Forest Waste site is primarilyderived from Wisconsin Age glacial deposits, and generally consists oflayers of medium sand with fine gravel, alternating with layers of siltyclay morainal till deposits.

Bedrock In tht slti vicinity is reported to be the Pennsylvanian AgeSaginaw formation. Generally, the Saginaw formation is a series ofirregular aquifers. Sedrock described in residential well drilling legs ispredominantly sandstone, with interbedded layers of shale and limestoneranging from I to 39 feet thick. Generally, these interbedded layers ofshale and limestone are less than 20 feet thick, averaging about 9 feet inthickness.

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"hrse hydrogeologic units, occurring it different e1evat':ns ;eneatn t-esite, have been identified 1.1 tie saturated g l a c i a l <e::sits. "hes'e ire:

o Shallow Aquifer: -n unconfined aquifer consisting ofaaoroxi-v-jtaly 20 feet of fine to medium sands, inq 'ocjtsd3:pr:x:-ataly 10 to 30 feet below ground surface.

o T i l l Acuiclude: A low peneable confining unit, consisting of10 to 30 feet of g l a c i a l t i l l , and located approximately 20 to 25feet below ground surface.

o Oeep Aquifer: An aquifer consisting of 7 to 27 feet of medium-coarse gravel, and located approximately 40 to 60 feet belowground surface.

The shallow aquifer unit, in general, is a very fine to medium-grained sandcontaining some silt, with only the lower half of the sand layer oeingsaturated.

The shallow groundwater flows toward the east at the northern portion ofthe site and toward the southeast at the southern portion of the site asshown in Figure 3. [n general, this flow is directed toward and dischargesto the marshy region and Butternut Creek.

"orizontal hydraulic gradients are relatively flat in the western half ofthe site, with values of 0.0007 ft/ft in the north 'in the vicinity of tnelandfill) increasing to 0.005 ft/ft in the south, "he gradients varybetween Q.OG4 and 0.007 ft/ft over the eastern half of the site.

"he estimated hydraulic conductivities for the shallow aquifer are between5 x LQ-4 en/sec and I x 10" cm/sec. These fall within the expected rangeof hydraulic conductivities of sllty sands to clean sands.

Average linear groundwater velocities for the western half of the site Irange from about 2 ft/yr in tht north (in the vicinity of tht landfill) toabout 17 ft/yr in the south. Velocities for the eastern half of the sitevary from about 13-24 ft/yr. These velocities art based on an averagehydraulic conductivity of 1 x 10-3 cm/sec and an assumed effective porosityof 0.30.

The effect of tht landfill on groundwater elevation, direction, andvelocity can bt estimated, but cannot bt fully assessed because of the lackof information on tht groundwater beneath tht landfill. Water levelsmeasured in monitoring wtlls adjacent to tht landfill indicate that agroundwater mound may bt present, but dots not extend btyond tht estimatedlandfill disposal area boundaries.

The shallow aquifer appears to bt continuously undtrlain by a silt or claytill of low hydraulic conductivity whost thickntss rangts fro* 15 to 27feet. Most of tht low hydraulic conductivity mattrials in this confining

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layer are clay t i l l s , out a sredcm:nantl/ s i l t t ; l l is present -i :-e .::a«-3 feet near the northwest corner :f :?e site.

"he hydraulic conducti/ity v a l u e s for the t i l l , c a l c u l a t e d '--om * a i l ; n giead ;emeabi1ity test, range from 1 < 10'7 to 5 * 10"3 :m/sec. Easaci :n ah y d r a u l i c conduct! my of 1 x 10"' cm/sec, an assumed ef'ecti/e sorosi:/ :ff3.20, and a / e r t i c a l hydraulic gradient range of 3.4 to 0.3 ft/ft, f.eaverage downward ground-water velocities range from 0.14 to 0.23 ft/yr.

The deep aquifer varies from 7 to 27 feet fn thickness. The compositionvaries from a slightly silty, fine to coarse sand to a relatively cleansand and gravel. In general, the deeo aquifer groundwater flows toward thesoutheast in the western portion of the site and toward the southwest inthe eastern portions of the site as shown in Figure 4. Horizontalhydraulic gradients for both flow paths are similar, ranging from 0.001 to0.003 ft/ft.

Water levels in the deeo aquifer are consistently 11 to 15 feet lower thanthose in the shallow aquifer. Downward vertical gradients bet-ween the twoaquifers range from 0.-4 to 0.3 ft/ft. The differences in both the waterlevels and tht flow directions of the upper and lower aquifers indicatethat the hydraulic connection between aquifers is limited.

In situ hydraulic conductivity testing determined that hydraulicconductivities of the deeper aquifer range from 1 x 10"3 cm/sec to 7 x 10*5 cm/sec. Based on a hydraulic conductivity of 1.3 x IQ-3 cm/sec, anassumed effective porosity of 0.30, and a horizontal hydraulic gradient of0.001 to 0.003 ft/ft, the groundwater velocities range from 4 ft/yr to L3ft/yr.

The Forest Waste Disposal site lies just west of a marshy area. Surfacewater bodies include a small lakt 1/2-m.ile north of the site and a smallresidential pond southeast of the site. Surface drainagt across the siteis southeast to Butternut Creek. Tht marshy area west of tht site alsodrains into Butternut Creek, which flows past tht southeast corner of thesite (approximately 1,000 feet from tht eastern site boundary). ButternutCreek flows southwest for 3 miles btfore discharging Into tht Flint River.

Residential wtlls In tht vicinity of tht sitt draw water predominantly fromtht bedrock sandstone aquifer. Tht location of residential wtlls in closeproximity to tht sttt and where known, tht approximate well screen depth,are shown IN F1$urt 5.

SITE HISTOtT

Previous Activities

Forest Waste Disposal is now closed. It was first optrated as a.sanitarylandfill in 1972. An Order of Determination was Issutd by tht Michigandepartment of Natural Resources (MONR) Water Resources Commission onOecembtr 21, 1972, to property owners Walter and Elaint R1x to receivelimited types of liquid industrial waste in accordance with Michigan Act

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A R O O O O I O

215, PubHc Act 1929, *s amended. Subsequently, jndar MfCv-an ;-. = .A. 1965. licenses were issued :o tie proper:/ owners ;3 '•scai/e jererrrefuse, and industrial and l i q u i d waste f'-om 3ecemoer 10, 1973 to leote-ce";, 1373. During this time, the M n d f i l l was ilso granted remission :oaccsot, on occasion, hazardous waste 'i.*.t polyorominatad oiohenyls '333ool/chlorinated o i p n e n y l s (?C3)] jncer VC!,NR and C-enesee County -eal'thDepartment 'jC-0) Supervision. The exact iate on wnic.h t.ie -ores* .<astaDisposal site cegan accepting waste is not <nown, but it is t.hougit" to ;ano sopner than when the licenses were issued, [n 1974, the f a c i l i t yaccepted sludge and residual waste from tne Agrico Chemical Warehouse ofBridgeport, Michigan. Likewise, ?C3 and ?33 were disposed of at the si*3in 1375.

In 1975, Mr. Six died and ownership of the landfill was assumed Oy Mrs.Six, who currently resides in Florida. The site license was reviewed forrenewal in 1973; the GCHO did not grant renewal due to operational andvarious other violations. As a result, Mrs. Six was ordered to properlyphasetout the site according to the guidelines established under theMichigan Solid Waste Management Act.

Curing operations of the site, incoming wastes to the l a n d f i l l were notscreened by the facility owner. Drummed wastes from various sources,including wastes transported to tne site by Berlin and Farro Incineration,were disposed of in the landfill area. The waste fill is covered, althoughrefuse and rusty drums are exposed in some places.

MQNR files indicate the lagoons originally accepted metallic sludges, wnicnwere to be pretreatad before receipt onsite, and acidic and basic l i q u i i s ,which were to be neutralized before shipment to the site.

Among the types of wastes which have been documented as being accepted atthe site, those suspected of being disposed of in the onsite lagoonsinclude the following: waste oils, septic tank waste, plating wastes,phosphate zinc wastes, metal sludges, spent sulfuric acid, and paintwastes. MONR file information indicates that incoming wastes were notscreened by the facility owner and that the operator often mixed differentwaste streams in somt o-f the lagoons. The operator was also suspected ofdischarging liquid wastes into the landfill area and onto the ground.

In Oecembtr 1982. tht site was placed on U.S. EPA's National PrioritiesList (MPt) of abandoned or uncontrolled hazardous waste sites eligible forinvestigation and cleanup under the Superfund Program.

In January 1984, a Remedial Action Master Plan (RAMP) for the Forest wasteDisposal Site was completed by U.S. £PA contractors. The RAMP is a.planfor undertaking Remedial 'investigation (RI) activities and identifyingappropriate initial remedial actions at a site.

In 1984, tht U.S. EPA constructed a fence around tht sltt and postedwarning signs. The fence was installed to serve as a deterrent totrespassers and thus help prevent humans from coming into direct contactwith hazardous substances at the site.

A R O O O O I I

In June 1986, U.S. E°A selected a cleanup a l t e r n a t i v e for the s i t e 'agccisource materials, "he lagoon cleanup action is in 'emedial resign :nase.The selected lagoon remedial alternative is removal and offsita treatmentand disposal of lagoon li q u i d s ; and removal, onsite treatment, and offsitedi s p o s a l of contaminated lagoon sediment, sludge, and so i l . Construct'onfor lagoon cleanup is scheduled for Summer 1388.

In 1987, ownership of the RrfO site was assumed by MONR because of taxpayment delinquency by the previous site owner.

Current Site Status

In December 1983, a Remedial Investigation (SI) was initiated to define :-,enature and extent of contamination at the site and characterize thepotential threats to public health and the environment from the site. 'Ifield activities were performed in three phases and were completed in A p r i l1987. The RI included geophysical and hydrogeologic investigations todefine the site hydrology and hydrogeology and to better identify areas ofsuspected drum burial in the l a n d f i l l . Environmental sampling was alsoperformed to determine the type, extent, and magnitude of contamination atthe site.

The results of the RI are described in the RI report, dated August 23,1987. This report also summarizes site data collected previous to the si,oy the Genesee County Health Department (3CHO), MONR, and U.S. E?A.

The site Feasibility Study (FS) was completed January 20, 1988. The FSdocuments in detail the development and evaluation of an array of remedialaction alternatives for tht FWO site.

Site Characterization

The following discussion briefly summarizes tht nature and extent ofcontamination according to tht respective media sampled during RIinvestigations.

1. Landfill Contents

In gtittral, flvt classifications of contaminant sources wtrtencoimttrtd during tht landfill investigation: bulk wastes,drumjMd liquids and solids. P88-contam1nated cattle fetd, agriculturalchemical warehoust flrt debris, and contaminated soil. It should beemphasized that tht landfill is incompletely characterized. Fifteentest pits wtrt excavattd ovtr tht 11-acrt landfill area. Tht intent ofthe investigation was not to fully establish tht naturt and extent ofcontamination, but to verify somt of tht manifest and disposal fileinformation for tht site.

Juried drums -were discovered at several test pit locations(Figure S). The drums contained primarily noncorroslvtvolatile organic compounds (solid and liquid) in high concentrations.

AROOOOI2

Test pit soils sjr-rjnding tie drum's were ilso fojnd to :econtaminated w i t n t"e same constituents oresent in tie irjms,but at somewhat 'o'wer concentrations, 'his suggests fiat e'-herpast disposal practices included tne dumping of noncontaineri:ad. l i q u i d s and sludges, or drum leakage has occurred. One percnedwater sample ta:<en *rcm a tast pit excavation also contained s i m i ' i rv o l a t i l e contaminants as discovered in tne drummed s o l i d s and1i q u i d s and test :it soi1s.

Cattle feed contaminated with ?38 was found wnere indicated oyMONR file information.

2. Groundwater

Two general areas of the shallow aquifer appear contaminated,southeast and east of the landfill and southeast and east of thelagoons. The area southeast and east of the landfill ischaracterized by relatively high specific conductance values. This islikely due to past brine disposal in that area of the site. Inaddition, the shallow aquifer east of the lagoons contains areas ofrelatively high pri (greater than 9) and several organic compounds(trans-l,2-dic,hloroethene, 1 ,1 ,1-trichloroethant, toluene, 1 , 1 -dichloroethane, and trichloroethene). The deep aquifer containedseveral inorganic constituents at elevated levels above background;however, no patterns or plumes were identified. Sporadic lowconcentrations of organics were detected in the deep aquifer; however,the types and distribution of constituents did not reveal any patternsof contamination.

Table 1 lists the 13 organic constituents detected in groundwatersamples from both the shallow and deep aquifers at the site.

It is not apparent that tht site contaminants found in thelandfill and the lagoons can account for the detection of organics in-the deep aquifer. Furthermore, tht inconsistency in detection ofcontaminants in the two aquifers suggests that contamination nf theshallnw aquifer has not affected tht deeo aquifer. This is alsosupported qy tnt hydro geologic, cnarac ten sties (now direction andhorizontal gradients) of tht two aquifers and tht confining unitbetwttn them. However, interaction between the two aquifers is notimposilblt.

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Tht naturt of tht release to the shallow groundwater suggests the sitelagoons ar» the source of this contamination. Several volatilecompounds 4W/u) in tht lagoons wtrt also round in tht shallowgroundwater to tht east and southeast. Tht extent of this release islimited to onsite areas. RI data from monitoring wtlls surrounding thelandfill have indicated that wastt releases from tht landfill have notaffected groundwater downgradient from tht landfill.

Residential drinking water wells wtrt sampled during tht sitt RI.'!o hazardous substance list organic compounds wtrt detected in

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the residential w e l l water. Inorqanic concentrations detected :onot suggest that tie w e l l s nave oesn affected oy tie site.

3. Surface Soils

Inorganic constituents of primary concern in the l a n d f i l l surfacesoil included oarium, lead, and nickel. Organic compounds, sucnas polycyclic aromatic nydrocarbons (PAHs) and pesticides (DOT, :Q£e.ndosulfan, and d i e l d r i n ) , were present throughout the l a n d f i l l area.?33s were present in the northern surface portion of the l a n d f i l l ,coinciding with the reported disposal area of contaminated cattlefeed. The peripheral areas of the landfill contained elevatedlevels of arsenic (aoove bac<ground) and chlordane.

4. Lagoon Liquids, Soil, Sediment, and Sludges

The constituents found in the lagoons are described in detailin the Forest Waste RI report (August 28, 1987). The remedialalternative for the lagoons has already been selected and designis underway. Therefore, further discussion of the findings forthis document is not necessary.

5. Qffsita Surface Water and Sediments

The type and distribution of compounds detected in the offsitesurface water and sediments did not reveal any pattern ofcontamination. One surface water location has a number ofinorganic constituents that exceeded Federal Ambient WaterQuality Criteria. It is likely that the higher concentrationsof inorganics merely reflected the poorer quality of waterin the wetland area and the possible entrairtment of suspendedsolids in the shallow sample.

RISK ASSESSMENT SWtURT

A baseline risk assessment was performed as part of the FWO RI (Chapter 6)to evaluatt potential sitt hazards to public health and tht environmentassuming no remedial action is taken at tht sitt. Tht risk assessmentincluded tht following:

o Idtnt1fl"cat1on of potential chemicals of concerno Toxlclty Assessmento Exposurt Assessmento Sisk Characterization

The potential chemicals of concern wtrt Identified in a constrvatlvtfashion at this sitt. Distribution of sitt contaminants Idtntifled in theRI was somewhat sporadic, indicating areas of dlscrttt contamination asopposed to area-wide contamination. Therefore, any chemical detected *ttht site having a critical toxicity valut (I.e., cancer pocteiicy factor jr

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reference dose) was i d e n t i f'*ed (as a ootsntnl c-emicjj o_f '•onca-i. iacaitionai cnemicais, w i t h o u t c r i t i c a l coxic't/ / a i j e s , were 'cant;*'-potential chemicals of concern, oased on c r i t i c a l t:xicity /aijes ofs i m i l a r chemicals, ^olyorominated oionen/1 'V333) was also i d e n t i f i e dpotential chemical of concern because of its persistence and :qent:f;"as a p o t e n t i a l :a"c:"03en oy the National Toxicology 3rogra,'n. "-ioiel i s t s tne vi 3 s i t e potential contaminants of concern. . . .

Potential chemicals of concern were then described in terns of treirtoxicological properties in a toxicity assessment.

In the exposure assessment, potential pathways by which humans and will! irepopulations could be exoosed were identified. A oathway is consideredcomplete if all the following elements are present: A contaminant source,a mechanism for chemical release, an environmental transport medium andexposure point, and a feasible route of exposure. Exposure pathways areconsidered for current and future land use conditions.

The exposure pathways of qreatest interest under current land useconditions are.

o Exposure of trespassers by direct contact with exposed•wastes and contaminated soil onsite

o Exposure of terrestrial w i l d l i f e by direct contact withexposed wastes and contaminated soil onsite and bycontaminant uptake through the food chain

o Exposure of wildlife populations that come into contactwith surface water/sediment contaminated by discharges(runoff and groundwater) from the site

o Exposure of downgradient groundwater users from ingestion ofcontaminated groundwater

Under a future land ust. for tht site the exposure pathways of interestinclude:

o Exposurts from residential development associated withdlrtct contact with soil and groundwater use

o Exposurts from commercial development associated withdirect contact with soil and from groundwater ust

A Risk Characterization was performed in which public health andenvironmental risks to potentially exposed populations wtrt presented. Thepublic health evaluation was performed for each exposure media andincluded: I) a comparison of estimated intakes (of contaminated-media) toacceptable intakes for noncarcinogenic chemicals; and 2) an estimation ofexcess lifetime cancer risk from exposure to carcinogens. Out to thtsporadic nature of the contaminant results, maximum detected contaminantconcentrations were used in this assessment. Under current land use

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conditions, pu b l i c health effects of concern .vere 'dentif'ed -eMv.e :o >.jirect contact exposure to l a n d f i l l surface s o i l and sur-ace :r.-s • ? :-?'andfill area. Long-ten exposures to ' a n a f i l l sur-ice s o i 1 :/ :-«spi33r-sc o u l d result in a reference qose^'xfd) axc_eedarce •"-cm 'ead ' - z e s t - o n a-: \cancer risk greater than 1 x 13"° ''•om pel yaromatic iyqrocar:c"3^'gJre 7 •'11 .,stra tes the areas of concern ...ider a cjrrent l a r c .33sett:-g ""or long-tern exposures.

in acute exsosure threat, further-lore, exists fron the landfi.l! via adirect contact threat from nig.nly concentrated contaminant source iater'a'3identified on the l a n d f i l l surface. An estimated 100-200 drums are exposesat the landfill surface. Samples taken during the RI identified n i g ncontaminant concentrations in drums. Results of a liquid samole tf--om asurface landfi l l drum, for example, detected a single chemical ' tol aenei '.:34 percent by weight.

Under current land use conditions. th*»n» is no oublic health threat fromUMB contaminated grounawdfcsr onsite. Inere are no current users of thisonsita groundwater, and groundwater transport modelling has shown, underconservative modelling conditions, that the contaminants will not reach thecurrent offsite groundwater users. The suspected source of thiscontamination, the onsits lagoons, is scheduled for complete cleanup inTate'1388.

Jnder future land use conditions, rgsidential and commercial/industrial ^seof the site was considered. In this setting, snilar to the current l a n duse setting, long-term exposure to landfill surface soil could result inreference dose (Rfd)^exceedances from lead ingestion and a cancer riskgreater tnan 1 x LQ-5 from ?AHs. Also similar to the current land usesetting, surface exposed drums present an acute uirect contact publicnealth threat. Figure 3 illustrates the areas of concern under a futureland'ust residential setting.

Under future land use conditions, the onsite contaminated shallowgroundwater may bt used for drinking water. Using maximum detectedcontaminant concentrations, the excess lifetime cancer risk under aresidential drinking water scenario is 1 x 10*5. No reference doses areexceeded undtr tht drinking water scenario.

A significant thrtat to tht groundwater also exists from the landfill wastematerial, particularly tht drummed wastes. These wastes are in anuncontalntd situation; leachate generation and liquid waste releases mayeventually rtsult in groundwater contamination. Due to tht highconcentrations of wastes in the landfill, an uncontrolled release nayresult in contamination to current offsite, as well as future onsite,groundwater drinking wells.

3ased on the RI data, exposures to contaminants in surface water andsediments undtr a current ust scenario would bt of limited conctm. Thepopulation at risk is small, and releases of contaminants to this media isundocumented. Under a future use scenario, current groundwatercontaminants which would eventually discharge to nearby surface water

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"aple 3 l i s t s ground-water contaminants detected in the '.I comoare-1 to 2-if?Drinking Water -c: '-'aximum Contaminant Levels C'CLs) 2nd M a x i m urnContarni^ant -aval Goals (''CLGs). In one case, a comoound aetectao '-cmgroundwatar samples exceeds the MCL. Tricnloroethene (TC£) was ,atactad u11 ug/1. 'he MCL for TC£ is 5 ug/1.

Tables 4A and 48 list the calculated contaminant concentrations ofgroundwater from the contaminant plume on the eastern edge of the site,before it would discharge to the nearest surface water body. "Thesecalculations are based on maximum and mean contaminant concentrationsdetected. These contaminant concentrations are compared to Federal AmoientWater Quality Criteria (AWQC) for the protection of freshwater aquatic l i f eand State of Michigan Surface Water quality Guidelines Levels forProtection of Aquatic Life. If this plume is allowed to discharge to thenearest surface water body, it does not appear likely that these criteriaw i l l be exceeded.

For. complete details of the Risk Assessment, Chapter 6 of the RemedialInvestigation (August 23, 1987) and Appendices A and C of the FeasibilityStudy (January 20, 1988) should be consulted.

COHHUNITT RELATIONS

The Superfund activities at the Forest Waste Disposal Site have beenfollowed closely by the local community and press. The MDNR currently nast.-.e lead role in community relations activities at the site. The State andthe U.S. E?A have worked together to keep communication with the communityopen and frequent.

There is an active mailing list of local citizens 'who receive updates aboutsite activities. Newsletters are periodically mailed to the citizens,updating them on recent sitt activities. Mint newsletters to date havebeen sent to tht community.

A Citizens Information Committee (CIC) has bttn formed by tht State. Thisis a group of local citizens and Federal, State, County and local officialswith high Interest In site activities. This group meets periodically toreceive Information about sitt activities and exchange information aboutcommunity concerns. Tht committee members servt as liaisons between thelocal citizens, and MONR and U.S. EPA.

There have been periodic meetings held at tht site to keep tht publicinformed of tht sitt activities. Tht Initial mtttlng was an RI/FS kick offnetting htld May 9, 1984. A more recent meeting was held afttrfinalization of the RI Report on October 1, 1987. At this mtttlng tht

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11public was provijed with a handout *nich o u t l i n e d the general :>.'•smedlal response a c t i v i t i e s under ccnsi jeration for :.ne p i n a l act:ne sitt.

A puoiic meeting *as -.elj on February 17, 1388, to discuss the :uo:c-rent :raft :~.. ~'na p u o l i c ::.TTment period was Held January 13 :reor'Jary 27, '.933. "~e attached rasoonsiveness summary addresses:o,Tients and questions raised at the Feoruary 17, 1388, meeting a-^a :-r- —:ne puolic coranent period.

ENFORCEMENT

'J.S. EPA has identified approximately twenty-five Potentially Resconsi:^e'arties (PRPs) for the Forest Waste Disposal site. U.S. EPA identified -.-3PRPs on the oasis of site records and responses to information requestssuianitted pursuant to Section 104 (e) of CERCLA.

A PRP steering committee has been established since May 1986 when the*ere noticed for the operaole unit lagoon remedial action. The PRPs navebeen active in exchanging information about the site since that time. ThePRPs have reviewed and commented on the U.S. EPA RI report, as *ell asconducted and suomitted tneir own FV<0 Endangerment Assessment and•easibility Study, "wo meetings discussing approaches to site remediation*ere held with the PRPs prior to issuance of the U.S. EPA Public Comment:raft FS.

Cn January 13, 1388, representatives from U.S. £?A and flONR met *itn t-e33?s in Lansing, Michigan to discuss the PRP recommend proposal in tneueragnty and Miller Feasibility Study, dated December 13, 1387 for acomoined remedial action on the site lagoons, landfill , and groundwater.The 3RP proposal included: fence, site restrictions, groundwatermonitoring, pumping lagoon liquids for offsiti treatment and disposal it aRCRA facility, backfill lagoons and cover with a low permeability cap,removal and offsite disposal of approximately 100 surface drums in thel a n d f i l l , and cover landfill with a low permeability cap. At that -nesting,U.S. EPA provided tht PRPs with an updated outline of sitt remedial actiongoals, and alternatives currently undtr consideration In tht draft U.S. i?AFS. This outlint was also supplied to tht public repository.

Tht discussions at this meeting focused on tht protection needed for thesitt shallow aquifer. Tht Agencies maintained tht oositi^n that thisaau1f«i» f« *"drinlc1na wattr aouirer. Tht Agw.-.«.>e» also exprtsstd concernstnac tnt PRP proposed landfill action would not providt adtquatt protectionto the shallow aquifer.

Discussions at this meeting also focused on tht ortftrtnet cited In'CERCLA121(o). U.S. EPA represtntitivts explained that tht prtftrtnct was rortreatment of hazardous substances to significantly and permanently reducethtir toxicity, mobility, and volume, and that containment rt«td1ts, whichreduce mobility of hazardous substances to tht groundwattr do not satisfythis preference. U.S. EPA indicated that the PRP proposal dots not satisfythis preference.

5R000026

U.S. EPA also stated that the lagoon ooeraole jnit remedy conf -'gurar :nnot negotiable. This remedy was selected by J.5. E3A in June '.336 and -scurrently 1n design pnase. Several discussions w i t h t.ne 33.Ps aoout this'•smedy took place oefore and immediately after :ne remedy *as selected.The PRPs were again offered the opportunity to undertake the lagoon remedyas configured in the June 1386, ROD. . .

On January 22. 1383, representatives from U.S. EPA and MONR -net with tnePRPs in Chicago, I l l i n o i s . The PRPs presented a new site cleanup proposal(dated January 21, 1988) which included: fence, site restrictions, removalof approximately 100 surface landfill drums for offsite disposal, coverlandfill with a low permeability cap, construct slurry wall around l a n d f i l lperimeter, construct dewatering system at site perimeter with onsitetreatment and discharge, 30-year long-term maintenance of cap and periodicgroundwater monitoring, and pumping and treating shallow aquifer in theeastern area of the site. The PRP proposal also included a lagoonremediation for offsite RCRA disposal of liquids, offsite RCRA disposal ofsix inches of lagoon solids, and covering lagoons with a low permeabilityengineered cap.

The above comment from tht January 13, 1988, meeting on lagoon cleanup wasreiterated to the PRPs by U.S. EPA.

Concerns from the Agencies about the January 21, 1988, PRP proposal wereexpressed, and included:

1. A concern about the ability of a slurry wall to contain wastesassociated with drums at the site.

2. A concern about meeting the CERCLA 121(b) preference for treatment.

3. A concern that the containment system be maintained beyond 30years.

The PRPs expressed concerns and an opposition to any landfill excavation.The PRPs expressed concerns about short-term risks from landfillexcavation. Tht PRPs txprtsstd concerns about defining the limits of apartial landfill excavation.

On January 28, 1988, Special Notice letters pursuant to Section 122 (e) ofSARA of 19tf were sent to the PRPs.The most recent negotiations with the PRPs was held February 23, 1988, inChicago, Illinois and included representatives from U.S. EPA, MONR, and .thePRPs. The PRPs reiterated the merits of their January 21, 1988, proposal.MONR representatives discussed their concerns about the unknown extent ofdrum excavation in the U.S. EPA preferred Alternative SRCVT. The PRPsreiterated their concern about any landfill excavation activity.

AR000027

13

~*e January 21, 1388, PRP proposal is considered a good f f a i t h proposal. "-?•Horatoriun for i n i t i a t i o n of remedial acfon at tne s i t e wi!' extend „,-,:•'"June 3, 1988.

DOCUMENTATION OF SIGNIFICANT CHAISES [SECTION 117(b)]

The i n c i n e r a t i o n treatment comoonent of the selected l a n d f i l l -emedialaction, Alternative SRCVT, and l a n d f i l l Alternatives RON and 3C!F -.as scopedin the FS and Proposed Plan to oe implemented at a compliant offsite 3C3,Aincinerator. Cost information a v a i l a b l e at the time of the FS suggestedthat use of an offsite incinerator would be less costly than use of anonsite incinerator for the volumes of waste proposed in these alternatives(see page 5-5 of the FS). Recent cost information has suggested that anonsite incineraiiofl <ni* $& less costly than offsite incineration for thevolumes or waste slated for incineration in Alternatives SRCVT, R3N, andROF.

These remedies are best configured to allow for the option of incineratingthese wastes onsite or offsite, depending on which option is less costly atthe time of remedy implementation. The short-term risks to the communityduring onsite incineration are manageable and balance against the risks tothe community during the offsite transport of wastes in the offsiteincineration option. An onsite incineration option was fully developed andpresented to the public for comment in Alternative RTO. "o commentspecifically directed to onsite incineration was received during the 3uolicComment Period.

The selected landfill Alternative SRCVT will be configured to includeonsits or offsite incineration of the excavated drummed wastes. In thebidding and award of this construction job, the less costly incinerationoption may be incorporated into the remedy.

ALTERNATIVES DEVaOPMCTT

Remedial Action Goals

General remedial action goals outlined in the National Contingency Plan(NC?) (40 CFR Part 300) and CERCLA as amended by SARA were reviewed, andFw'O site specific goals were established. In evaluating the findings ofthe RI and Risk Assessment, two separate areas of concern, or operableunits, wtrt Idtntlfltd at the site: 1) soil and landfill contents; and 2)groundwater at the eastern end of the site. Specific* goals for each ofthese two operable units follow.

The specific remedial action goals for the soil and landfill contentsoperable units are:

o Prevent direct contact exposure to soil or landfill sources thatcontain contaminant levels in excess of target concentrations for:- "oncarcinogenic health effect protection (based on reference

doses)

AR000028

14I

- Excess lifetime cancer r i s < ;n tie "inge :f '.;•* to I]'7

o 3ravent migration of contaminants fr:i t".e s o i l :r scurtss -itie l a n d f i l l to a d r i n n i n g water aquifer t.nat would contaminate

to concentrations:

greater tnan the MCLs

•xceeding the lifetime health advisories

- Exceeding levels for noncartinogenic health effect protection(based on reference doses)

- : Resulting in an excess lifetime cancer risk range of 10"* to ID"7

o Prevent migration of contaminants from the soil and sources in thelandfill to a surface water body that would result in contaminationto levels greater than the Federal Ambient Water Quality Criteria orState of Michigan Surface Water 'Quality Guideline Levels for theProtection of Aquatic Life. ;

o Control future release of contaminants to ensure protectionof human health and the environment ( SASA Section 121 (d)).

o Consider a preference for remedies that permanently andsignificantly reduce toxicity, nobility, or volume of hazardoussubstances through treatment to the greatest extent practicaole (SARASec 12i(b).

"he specific remedial action goals for the qroundwater operable unit are:

o Assure the quality of groundwater in drinking water aquifersand prevent migration of contaminants to a drinking water aquiferthat would contaminate groundwater to concentrations:

- Greater than the' MCLs

- Exceeding the lifetime health advisories- Exceeding levels for noncarcinogenic health effect protection

(based on reference doses)- Exceeding a lifetime cancer risk of range ID'4 to 10*7

o Prevent migration of contaminants to surface wattr body thatwould result in contamination to levels greater than the FederalAmbient Water Quality Criteria or State of Michigan Surface WaterQuality Guideline Levels for the Protection of Aquatic Life.

ARQ00029

~he identified shallow aid ieeo aquifers, as well as t"e :ear:c<aquifer underneath the ~'.«0 site, are considered drHxing water aqui'ers."he shallow aquifer is "ot currently jsed as a irinxi.ng water source.aquifer, however, if unaffected sy t.-e site contaminants, wouia oe :fsufficient quality and quantity to :e jsed as a inn<ing water source.

Appropriate remedial tscnnologies process options were screened in :-e r3.Fifty-five s o i l s and l a n q f i l l contents operaole u n i t remedial technologyprocess options were i n i t i a l l y identified for screening. ~hirt/-*ourgroundwater operaole unit remedial technology process options werei n i t i a l l y identified for screening. These process options were evaluatedrelative to their a b i l i t y to achieve the remedial act:on goals, abi l i t y toieet Federal and State a p p l i c a o l e or relevant and appropriate regulations,and inolementaoi1ity relative to site conditions. Twenty-seven soil andlandfill operable unit process options, and sixteen groundwater operaoleunit process options remained after initial screening.

A second screening of technology orocess options was performed based ontechnology performance (action accomplished), reliability (provenoperation), implementability (ease of construction), safety associated withconstruction and operation, and relative costs. After this screening,thirteen soil and landfill contents operable unit remedial process options,and seven groundwater operable unit remedial process options were retainedfor development of remedial alternatives. Only technologies which survivedscreening were used to formulate remedial alternatives.

Alternatives development

'Jsing the established remedial action goals, the FS then assembled theidentified technologies into operaole unit remedial alternatives[combinations of technologies to remediate the operable units).Alternatives which encompass a range of choices for remediating theoperable units were developed. This range included, for each operableunit, to the extent feasible:

o A no action alternative.

o At least one alternative that involves rontainment of wasttwith littlt or no treatment, but provides protection of humanhealth and the environment by preventing potential exposureor by reducing the mobility of the waste.

o Treatment alternatives ranging from one that would eliminatethe need for long-term management (including monitoring) at thesite to one that would use treatment as a principal elementto reduce the toxicity, mobility, or volume of contaminants.

15

description of Altarnati/es

-ie "anedial alternatives are organised into two groups: a l i s t :f 31 Tlternatives to address the soi.l and l a n d f i l l contents operaole u n i t , L

;ntalternatives to aaqress :ne soi. i ana l a n a r n i contents operaole u n i t , and'ist :f *our alternatives to address the groundwater operaole unit.

All a l t e r n a t i v e s developed include ;iplementation of the lagoon oparaole^nit selected remedy.

1. Landfill Soil and Source Material

Alternative NA - - No Action

Total Present Worth: SOConstruction Cost: SOPresent Worth O&M Cast: SOAnnual Q&M Cost: $0Time to Implement: none

Alternative ,'IA assumes that no further corrective actions take place andthat no restrictions are placed on future uses at the site. The fence thatwas installed in 1384 will remain onsite. Repair and maintenance of thefence w i l l be continued by MONR. This alternative also recognizes thatliquids, soil, sediment, and sludges associated with the lagoon wastes willoe removed as planned for in the lagoon operable unit selected remedy.This alternative is considered as a baseline scenario to which otheralternatives can be compared.

Alternative SR - Site Restrictions

Total Present Worth: $1,430,000Construction Cost: 574,000Present Worth O&M Cost 51,390,000Annual OiM Cost: 5202,500Time to Implement: 3 Months

The major components of Alternative SR are: access restrictions (deedlimitations), fence, and monitoring.

Deed limitations would be placed on the Forest Waste property and areas{.mediately surrounding the site. The deed limitations would prohibitexcavation of soil and/or landfill contents that might occur during futureproperty development. The fence that was installed onsite in 1984 willremain. Regular repair and maintenance of the fence will be performed byMOHR.

Contaminant migration from the soil and landfill contents would be assessedthrough a groundwater monitoring program.

Eight new monitoring wells (five shallow, three deep) would be installedaround the landfill perimeter. A total of 21 wells (IS shallow, 6 deep)

AR00003I

17

would be sampled and analyzed to detect -cnanges in the groundwaterCharacteristics under the l a n d f i l l area.

Sampling and analysis of groundwater would be per^omed :uarterly jur'ngtne first 5 years and semiannually thereafter. Samples would oe analyzed*or CL? organic and inorganic parameters, ?38s, lioxins, and conventionalparameters such as cnlonde, sulfate, nitrate, n i t r i t e , specificconductivity, and a l k a l i n i t y . Water levels of the monitoring w e l l s *ouldoe taken at the time of sampling and gradients would be calculated andcompared to existing data.

Alternative SRC - Site Restrictions with Soil Cover

Total Present Worth: 32,070,300Construction Cost: 3663,000Present Worth O&M Cost: $1,390,000Annual O&M Cost: $206,500Time to Implement: 2-3 Weeks

The major components of Alternative SRC are: access restrictions (deedlimitations), fence, monitoring, and soil cover. Access restrictions,fence, and monitoring are similar to Alternative SR. Alternative SRC addsa soil cover over the contaminated soils and landfill area.

A 2-foot minimum thick soil cover would be placed over the landfill andassociated contaminated soil to prevent direct contact with thecontaminated materials. The cover would not be designed to preventinfiltration of precipitation into the landfill. The cover would consistof onsite borrow soil. Prior to placing the cover, the landfill area wouldbe graded to fill existing depressions, eliminate any sharp grade changes,and improve surface runoff. After placement, the cover would be seeded andshaped to maximize evapotranspiration and minimize water ponding over thecontaminated area.

Maintenance and repair of the soil cover would be needed periodically.

Alternative .SRCV - Site Restrictions with Cap ind Vertical Barrier

Total Present Worth: 59,700,000Construction Cost: 58*006,000Present Worth O&M Cost: 51,554,000Annual OtN Cost: $250,000Time to Implement: 12 Months

The major components of Alternative SRCV are: access restrictions (deedlimitations), fence, monitoring, RCRA cap, and vertical barrier.

Access restrictions and monitoring are similar to Alternative SRC. A newfence would be installed around the landfill area to protect the cap and ^^

AR000032

13

prevent access to gas 'ents and groundwater monitoring mannoles. ~ke *::t:f the fence would be buried.

Alternative SRCV uses a multilayer cap and adds a barrier around thel a n d f i l l perimeter. The cap and vertical barrier are intended toeffecti/ely contain the contaminants by preventing i n f i l t r a t i o n into thel a n d f i l l area and contaminated soil (cap), and restricting groundwatermovement w i t h i n the l a n d f i l l (vertical barrier).

*he RC.RA cap would be constructed as specified in RCRA regulations andguidance. A gas collection system for tne cap would be installed.

A soi1-bentonite slurry wall vertical barrier would be constructed in tnenative soil surrounding the contaminated area. The wall would beapproximately two feet wide and 35 feet deep. The bottom of the wall wouldbe keyed into the low permeability glacial till layer underlying the site.A dewatering system would be installed inside the wall to lower the waterlevel under the landfill, creating a head differential toward the l a n d f i l land collecting any releases o.f liquid wastes inside the landfill. Noadverse effects to the wetlands east of the site is anticipated from thisdewatering and groundwater diversion.

Operation and maintenance for Alternative SRCV would include routinemonitoring and periodic repair of the cap, vertical barrier, and gascollection system. Groundwater collected from inside the landfill(leachate) would be periodically collected and properly disposed of ortreated. Proper treatment or disposal of the landfill leachate would bedetermined in design activities after leachate quality is determined.

Alternative SRCVT - Site Restrictions with Cao and Vertical Barrier.Source 3rum removal , and Treatment

Total Present Worth: 522,530,000Construction Cost: 520,337,000Present Worth O&M Cost: 51,554,000Annual O&M Cost: 5250,500Time to Implement: . 12 Months

The major components of Alternative SRCVT are: access restrictions,monitoring, fence, RCRA cap, vertical barrier, limited drum removal andincineration.^ All components of this remedy, with the exception of thedrum removal and incineration, are similar to Alternative SRCV.

Prior to tht containment activity, the areas of the landfill withconcentrated drummed wastes would be excavated, and drummed wastes would beincinerated onsite or transported offsite for RCRA incineration. Soilssaturated with contamination from the excavated drums would also beincinerated onsite or transported offsite for RCRA incineration. The drumremoval activity would be limited in scope and would not Include excavationof the entire 11 acre landfill.

flROOQQ33

19

An estimated 4,000 drums of wasts and 1,300 cubic yards !4,300 a runs ;•contaminated saturated soil would ce excavated from the l a n d f i l l e-rtreatment. The exact extent of the area of concentrated :runs wouli :e^etemihed in remedial :esign phase. The "3 estimate for the nu.moer ;•arums is conservative, oased on currently a v a i l a o l e information. ~ue ;:stestimate 'or t.nis remedy, tnerefore, is conservative. In remedial :es';n,t.ne :ost ast'tata C3r cms remedy would be ~ore refined.

Air monitoring would be conducted during excavation and tne potentialonsite incineration to evaluate exoosure risks from fugiti/e dust generatesduring excavation and to assure compliance with air quality standards.

Stormwater runon/runoff would be controlled during excavation throughgrading, the construction of perms, etc., as necessary to minimize theamount of Stormwater irainage that contacts contaminated excavation.materials and to ensure that any contaminated Stormwater is collected anddisposed of with the excavated drums.

Alternative RON - 3emoval , Source Drum Treatment, and Onsite Qisoosal

Total Present Worth: $29,620,000Construction Cost: $28,581,000Present Worth O&M Cost: $746,000Annual C&M Cost: $102,000Time to Implement: 5 /ears

The major components of Alternative RON are: complete waste removal,onsite or offsite incineration of drummed wastes, redisposal of remainingwastes in onsite RC.RA-type landfill, and RCRA landfill monitoring.

Approximately 200,000 cubic yards of material would be excavated from thelandfill area, resulting in a volume of 260,000 cubic yards of loosenedmaterial. Air monitoring and stormwatar drainage controls would beperformed during excavation as described In Alternative SRCVT, It isestimated that approximately 4,000 drums of waste materials would beencountered. The drums would be incinerated onsite or transported offsitefor RCRA incineration..trea,tment.

Remaining bulk' waste would be treated as necessary onsite to remove freeliquids, redisposed into a RCRA-type landfill, and covered with a RCRA cap.The newly constructed landfill cell would be located within the previousarea of waste-disposal. Groundwater monitoring would be performed asrequired by RCRA post-closure requirements.

Operation and maintenance would include leachate collection and disposal,periodic groundwater monitoring, repair of the landfill cap, and gasmonitoring.

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23

Alternative PDF - "eroval . Source Crum '-gatment, and :f*sita :is::s> •

Tptal Present Worth: S51,320,:COInstruction Cost: Sol,399,300Passant Worth CiM Cost: SOin.Tjal CiM Cost: SOT-'-e to Implement: 2 ''ears

Ccmponents of Alternative ROF are similar to Alternative RON, with theexception of the disposal facility. Materials slated for disposal would :ataken to an offsite RCRA-approved landfill.

"here would be no long-term operation and maintenance activities for thisalternative.

Alternative RTD - Removal, Treatment and Disposal

Total Present Worth: $130,500,000Construction Cost: $66,364,000Present Worth Q&M Cost: $63,888,000Annual O&M Cost: $15,742,000Time to Implement: 5 Years

The major components of Alternative RTO are: 1) removal of allcontaminated landfill materials, 2) treatment of all combustible excavatedmaterials in an onsite RCRA-type incinerator, 3) dewatering, as necessary,of the noncombustible excavated materials onsite, and 4) disposal, asnecessary, of treatment residuals and untreated materials in an onsiteRCRA-type landfill.

The operation and maintenance 'would be as described in the Alternative RDM.The onsite treatment system would require trained operators. Duringexcavation and treatment, appropriate air monitoring and, as necessary, ai--controls would be exercised. Stormwater drainage controls would also beexercised.

2. Groundwater

Alternative HA - No ActionTotal Present Worth: 50Constraction Cost: SOPresent 'Worth O&M Cost: 50Annual O&M Cost: 50Time to Implement: none

This alternative is described under the soil and landfill contents operableunit section. No further action is taken to address the contaminantscurrently identified in the groundwater on the eastern side of the site.

The identified contaminants would be allowed to migrate with groundwaterflow. Any change in groundwater quality would be due to natural dilution,

• . . = —-

AR000035

adsorption and oiological degradation, 'lo m o n i t o r i n g wouli :e :er-"or-ed,cnerefore, no 'urther information apout groundwater q u a l i t y w o u l d :egained.

S3 - S'te

~otal =-esent ,ortn: S1,:90,:COinstruction Cost: S24,CCO^resent worth CiM Ccst: $1,254,000Annual CiM Cost: $139,500Time to Implement: 2-3 Weeks

The access restrictions component would be as described in the soil andlandfill contents Alternative SR. Ceed restrictions would be implementedto specifically prevent installation of new drinking water wells in theshallow aquifer at the site or in adjacent areas.

Changes in the location and concentration of the groundwater contaminationwould be assessed through a groundwater monitoring program. RI datacollected on the groundwater to date indicate that with one exception, allgroundwater remedial action goals are currently being met relative to theduality of affected groundwater (see Remedial Action Goals Section). Theexception met is a sample of groundwater from onsite monitoring well numberMW85-1 that detected trichloroethane (TCE) at U ug/1. The MCL for TCE is5 ug/1. The monitoring would be configured such that If groundwaterquality at the site boundary is anticipated to exceed any of thegroundwater remedial action goals, a remedial action plan for groundwatercleanup w i l l pe developed.

The monitoring program would include two new monitoring wells (deep)installed downgradient of the plume. A total of 14 wells (9 shallow, 5deep) would be sampled and analyzed to detect plume movement or changes inthe concentrations. In addition, a newly Installed or currently availableupgradient background well would be sampled to establish backgroundgroundwater quality.

Sampling and analysis of groundwater would be performed quarterly duringthe first 5 years and then the program would be reevaluated for changes inanalyses and sampling frequency. Samples would be analyzed for CLP organicand inorganic parameters and for conventional parameters such as chloride,sulfate, nitrate, nitrite, specific conductivity, and alkalinity. Waterlevels of tto monitoring wells would be take at the time of sampling andgradients would bt calculated and compared to existing data.

Annually, tht quarterly results of the sampling and analysis program wouldbe averaged and compared to the groundwater remedial action goals. At thesite boudary (monitoring well nos. MUSS-IS and MU85-2S), if on an averageannual basis, the quality of the groundwater is greater than MCLs,exceeding lifetime health advisories, exceeding levels for noncarclnogenichealth effect protection (based on reference doses) or exceeding a lifetimecancer risk range of 10"4 to 10" ; or offsite. upgradient of the wetlands,(monitoring well nos. MM86-4S. MW86-3S, and MU86-2S) 1f on an average

AROQOQ36

annual basis the quality of the groundwater is greater than Federal --p-e--Water Quality Critaria or Stats of Michigan Surface Water Xiality Guide'•"--"Levels for the Protection of Aquatic Life, a plan ffor further grounawater"^medial action would :e evaluated.

Alternative C~3J - C o l l e c t i o n , Cnsite 'rajt^ent. and Discharge

*ptal Present ,/orth: $3,760,000Capital Cost: $325,000Present Worth O&M Cost: $3,306,000Annual Q&M Cost: $465,000Time to Implement: 15 Years

The major components of Alternative CTGO are: collection of contaminatedgroundwater from the shallow aquifer, treatment of that water as necessaryto meet NPOES discharge permit requirements, and discharge of the water tothe Sutternut Creek.

iThe groundwater collection system would consist of groundwater extractionwells. Collection pipes from the wells would discharge to a common sump.Water would be treated, as necessary, with granulated activated carbon toassure compliance with NPOES permit discharge limits. The water would thenbe discharged to the Sutternut Creek.

Alternative CT? - Collection and Cffsite Treatment

Total Present Worth: 52,550,000Capital Cost: $205,000Present Worth O&M Cost: $2,319,000Annual O&M Cost $329,500Time to Implement: 15 Years

The major components of Alternative CTP are collection of contaminatedgroundwatar from the shallow aquifer and offsite treatment of the water ata Publicly Owned Treatment Works (POTW). .._

Collection of groundwater of Alternative CTP is similar to AlternativeCTGO. This alternative adds onsite groundwater storage prior to transportoffsite and treatment at a POTW. The possibility exists that pretreatmentprior to discharge to the POTW will be required for compliance with POTWlocal limits and Federal and State pretreatment regulations.

SUMMMT OF q»»AflATIYE ANALYSIS OF ALTERNATIVES

Each of the alternatives were evaluated using a number of evaluationfactors. The regulatory basis for these factors comes from the National •Contingency Plan and Section 121 of SARA (Cleanup Standards). Section121(b)(l) states that, "Remedial actions in which treatment whichpermanently and significantly reduces the volume, toxlcity or mobility ofthe hazardous substances, pollutants, and contaminants is a principalelement, are to be preferred over remedial actions not involving suchtreatment. The offsite transport and disposal of hazardous substances or

5R000037

23

contaminated materials without such treatment snould :e tne least faalternative remedial action wnere practicaols treatment technologiesavailable.' Section 121(5)(i) also states that ths f o l l o w i n g factors s.iape addressed during the remedy selection process:

'Av. :-e 'png-ta-i uncertainties associated with land d i s p o s a l ;;3) :ne —al's, ;ojecti/es and requirements of tne S o l i d *aste C i s p c s a l

Act;*(C) the persistence, toxicity, mobility, and propensity to oioaccumulate

of sucn Hazardous substances and their constituents;'3) snort- and long-term potential for adverse nealth effects from

human exposure; I(E) long-term maintenance costs; I( F) the potential for future remedial action costs if the alternative

remedial action in question were to fail; and(G) the potential threat to human health and the environment associated

with excavation, transportation, and redisposal , or containment.

Section 121 of SARA requires that the selected remedy is to be protectiveof human health and the environment, cost-effective, and use permanentsolutions and alternative treatment technologies or resource recoverytechnologies to the maximum extent practicable.

Alternatives were evaluated usinq current U.S. EPA guidance, including:"interim Guidance on Superrund selection of Remedy" dated December 24, 1986and "Additional Interim Guidance for FY'87 Records of Decision' dated July24, 1987. In the Jul v 24. 1987. guidance^, the following nin* evaluationfactors are referenced:

1. Overall Protection of Human Health and the Environment addresseswnether or not a remedy provides adequate protection, and describes howrisk are eliminated, reduced or controlled through treatment,engineering controls, or institutional controls.

2. Compl1ance with ARARs addresses whether or not a remedy will meet allof the applicable or relevant and appropriate (ARARs) requirements ofother environmental-statutes and/or provide grounds for invoking awaiver. (See discussion below).

3. Long-term effectiveness and permanence refers to the ability of aremedy to maintain reliable protection of human health and theenvironment over time once cleanup goals have been net.

4. Reduction of toxicity. mobility, or volume Is the anticipatedperformance of the treatment technologies a remedy may employ.

5. Short-term effectiveness involves the period of time needed to achieveprotection and any adverse impact on human health and the environmentthat may be posed during the construction and implementation perioduntil cleanup goals are achieved.

AR000038

24

5. Implementability is the tecnni:al and a d m i n i s t r a t i v e f e a s i b i l i t y :r aremedy, including the a v a i l a o i l i t y of goods and services needed toimplement the chosen solution.

T. :ost includes cap i t a l and operation and maintenance costs.

3. S;j3sort -:e*cy Acceptance indicates whether, Pased on ;ts roview of tneRI/FS ana'=roposed 31an, the suoport agency (M2NR) concurs, opposes, :rhas no comment on the preferred alternative.

9. Community Acceptance indicates the public support of a given remedy.This criteria is discussed in the Responsiveness Summary.

The analysis that follows was performed using the above factors as theyapply to each of the developed alternatives.

I. Soil and Landfill Contents

A. Alternatives Evaluation

Alternative MA

No protectiveness is provided by this remedy since no further action takesplace at the site. Short-term unacceptable risks remain from thecontaminated landfill surface soil, both to trespassers under the currentuse scenario, and residents under a future use scenario. Short-term acuteunacceptable risk from drummed waste on the landfill surface also remainunder both current use and future use scenarios. The unacceptable long-term release of contaminants from the landfill to the groundwater alsoremains. This long-tern risk to groundwater threatens current groundwaterusers and future residential onsite users of the groundwatar, as well assurface water bodies near the site, which receive groundwater discharge.No treatment to reduce toxicity, mobility, or volume of hazardoussubstances is included as part of this remedy. This alternative does notafford any permanence. The remedy will not meet the identified Federal andState ARARs for the landfill. .' .-

No construction-activities are associated with this remedy. Therefore,there art no construction implementability issues. This remedy will takeno time to Implement. This remedy is not supported by the State ofMichigan.

The estimated capital cost of this remedy is SO. The total present worthis 50. Estimated annual operation and maintenance (O&M) cost is 50.

Alternative SR

Some short-term protectiveness is provided by this remedy by reducing thethreat of direct contact risks from the landfll.1 soil and surfacematerials. This method of providing protectiveness, however, is notreliable, since prevention of trespassers in current and future usescenarios cannot be assured. The long-term risk of a release of landfill

wastes to the groundwater is not mitigated, "he groundwater monitor"1}w i l l only provide the information that a release nas occurred, snould thatoe the case. No treatment to reduce t o x i c i t y , m o o i l i t y , or volume ofHazardous substances is included as part of this remedy. This alternati/e:ces not afford any permanence. Protection of Human Health and theenvironment provided by this remedy is not adequate. This remedy w i l l *otmeet the identified Federal and State ARARs for the l a n d f i l l closure.

"HI'S remedy can oe e a s i l y implemented within a few weeks. A c t i v i t i e snecessary to implement the remedy w i l l not increase risxs of exposure tothe community or workers. This alternative is easy to maintain and iseasily modified. This remedy is not supported by the State of Micnigan.

The estimated capital cost of this remedy is $74,000. The total presentworth is $1,430,000. The estimated annual O&M cost is $202,500.

Alternative SRC

Short-term protectiveness is provided with this remedy by reducing existingrisfcs from direct contact threats from landfill soil and surface materials.These materials are covered with a minimum of two feet of soil. Thismethod should be reliable in alleviating the direct contact threat totrespassers. Deed restrictions, furthermore, may reduce trespassing. Thelong-term risk of a release of landfill waste to the groundwater is not,however, mitigated. Surface precipitation would be able to percolatethrough the cover, and serve as a potential solvent for landfill wastes,resulting in generation of leachate. Such leachate, and liquids wastescurrently in the landfill, may migrate to, and contaminate groundwater.The groundwater monitoring will provide information that a release hasoccurred, should that be the case. No treatment to reduce toxicity,mooility, or volume of hazardous substances is included in this remedy.This alternative affords little permanence. Adequate protection of humanhealth and the environment is not provided by this remedy. This remedydoes not meet the identified Federal and State ARARs for the landfill. Inparticular, the soil cover does not comply with RC.RA 40 CFR Section 264.310and Michigan Act 64 requirements for cover at final hazardous wastelandfill closure.

This remedy can be easily implemented with some quality control inapproximately three months. Risks to the surrounding community duringconstruction art negligible, and risks to construction workers are minimal.This alternative requires minimal maintenance. Modifications to the remedywould bt staple", potentially requiring some cover alterations. This remedyis not supported by tht State of Michigan.The estimated capital cost of this remedy is 5663,000. The total presentworth is 52,070,000. The estimated annual O&M cost is 5206,500.

Alternative SRCY

This remedy provides short-term protectiveness by eliminating directcontact threats from landfill soil and surface materials with a RCRA cap

flRQOQ(HQ

25

and deed restrictions, "^e cap is 3 reliable method to prevent trespassertfrom the direct contact threat :f l a n d f i l l surface materials. ~*e long.ten risk of a release of l a n d f i l l waste to the groundwater is m i t i g a t e dw i t h the cap, slurry w a l l , and lewataring system combination, 'hissystem sarves to fully contain the l a n d f i l l wastes. The p o s s i o i l i t y ofcontainment system failure exists if h i g h l y concentrated organic sol/entscontact tne s'jr"y wall or underlying t i l l and compromise t.ne 'Htegnty p*the system. A oroperly designed leacnate coHection system snouli,However, lessen such contact. The RCRA cap serves to s i g n i f i c a n t l y reduceprecipitation infiltration to the l a n d f i l l , ultimately reducing tnepotential 'for generation of landfill leachate. The slurry wall w i l l fullysurround la n d f i l l source materials. The wall keys into the lowerpermeability t i l l layer underneath the site. The wall will prevent thepossibility of upgradient groundwatar from coming into contact wi l ll a n d f i l l source materials. The wall w i l l contain l i q u i d and solidmaterials inside the l a n d f i l l , and the dewatering system will activelycollect any liquids (leachate and l i q u i d wastes released from drums) insidethe containment system. Collected liquids will be properly treated anddisposed of. The groundwater monitoring system will identify if a releaseoutside of the containment system (in the case of failure) has occurred.Treatment of the liquids from the dewatering system, although not specifieduntil the Remedial Design phase, will likely include some reduction of thehazardous substance toxicity, mobility, or volume. This remedy isprimarily a containment remedy. Treatment is provided only to the liquids.If properly operated and maintained, this remedy wi l l provide adequateprotection of public health and the environment. There are reliabilityconcerns about the system's ability to contain high concentrations ofsolvent type wastes associated with the drums. This remedy will meet theidentified Federal and State ARARs for the landfill.

This remedy can be constructed in approximately twelve months. The cap andvertical barrier require some technical ability to implement and qualitycontrol is necessary for an effective action. Construction workers andequipment are available for implementation. Risks to the surroundingcommunity during construction are negligible, and risks to constructionworkers are minimal since wastes remain in place. Maintenance of the capand slurry wall should be routine. Leachate and landfill gas collection,and treatment, will be necessary over an indefinite period of time.Modifications to the remedy would be difficult, due to the complex cap andsubsurfact slurry wall. This remedy is not supported by the State ofMichigan.

The estimated capital cost of this remedy is 58,006,000. The total presentworth is 59,700,000. The estimated annual O&M cost is 5250,000.

Alternative SRCVT

This remedy provides the short-term and long-term containmentprotectiveness as described in Alternative SRCV. In addition, thereliability and long-term effectiveness of the containment system is•greatly increased because areas of concentrated drunwed wastes are removedand thermally destroyed. The known complete, or a precise percentage, of

27

drums removed w i l l not pe <nown, since the entire l a n d f i l l w i l l tot :eexcavated. Drum removal -educes tne lUelinood of containment system'ailure, and reduces the stress on the leachate c o l l e c t i o n systan 'HH a n d l i n g high contaminant concentrations £r"in :rum releases. "H?S -emedyprovides additional treatment wnich s i g n i f i c a n t l y and permanently -educest o x i p i t y , - o o i l i t y , and /olume of Hazardous suostances. drummed wastesfrpm coHcent.-ited disposal regions are destroyed offsite or onsite oyincineration. "These drummed wastes contain nign concentrations :f t p x i ccontaminants whicn are relatively easily soluoilized in water, therefore,nobile in the environment. A principal element of the threat at tie sitsis treated with a permanent remedy. This remedy wil l provide adequateprotection of public health and the environment. This remedy w i l l meet theidentified Federal and State ARARs for the landfill.

This remedy can be implemented in approximately twelve months, including aconcurrent 5 month time frame for drum removal and onsite incineration oroffsite transport and incineration. In addition to cap and verticalbarrier installation concerns, precise definition and removal ofconcentrated drum areas w i l l present some implementability issues. Drumexcavation requires significant quality control. Construction workers,equipment, and offsite treatment capacity are available. Additional riskto workers beyond Alternative SCRV stems from drum excavation. Risk to thesurrounding community stems from offsite transport of drummed wastes or theonsite incineration of drummed waste. Maintenance of the cap and slurrywall should be routine. Leachate and landfill gas collection and treatmentshould be less than that in Alternative SRCV. Modifications to the remedy•would be difficult due to the complex cap and subsurface slurry wall, "heState of Michigan does not support this remedy. "His remedy is also notsupported by the surrounding community residents. (See attachedResponsiveness Summary).

The estimated capital cost of this remedy is 520,337,000. The totalpresent worth is 522,530,000. The estimated annual O&M cost is $250,500.

Alternative RON

This alternative provides reliable short-term protection by eliminatingdirect contact .threats from landfill soil and source materials with anonsite RCRA landfill which will properly cover wastes. The long-term riskof a release of landfill waste to the groundwater is mitigated with acombination of drum removal and offsite or onsite incineration anddisposal, and redlsposal of all remaining landfill hazardous substances andcontaminated soil in an onsite RCRA-type cell. The onsite landfill can bebuilt in tht previously located area of contamination, therefore, RCRA Land3an regulations for treatment may not apply. Such containment isconsidered very reliable: the RCRA cap prevents precipitation percolationand leachate generation, the landfill cell contains non-drummed wastes in adouble lined system with leachate collection. Tht leachate collectionsystem will provide for active collection and treatment of Uachatt, asneeded. A groundwater monitoring program will identify if a release fromthe containment system has occurred. This remedy provides thermaldestruction treatment of all drummed waste in the landfill. This

23 .i. - , Balternative utilizes treatment f:r destruction of t o x i c i t y , m o o i l i t / , andolume pf a principal element of fe threat. rhis remedy requires somemaintenance, but affords a high iegree of permanence. This remedy w i l lprovide 'adequate protection of puoiic Health and tne environment. "HISremedy w i l l meet the identified redenl and State ARASs for the l a n d f i l l .

"HI'S remedy :an oe implemented 'n approximately five years. Thisalternative requires complete waste excavation from the l a n d f i l l , r e s u l t i n gin significant waste handling issues, and requiring considerable technicalability and quality control to assure complete waste removal. Carefuldesign and quality control for ouilding the onsite RCRA-type cell w i l l oeneeded, -xposure risks to the workers stem from the significant wastehandling and extensive waste excavation. The significant amount of wastehandl ing extends risks to the surrounding community in addition to therisks from offsite transport of drummed wastes or onsite incineration ofdrummed waste. Construction workers, equipment, and treatment capacity areavailable. Maintenance of the RCRA-type cell should be routine and wouldinclude periodic cap replacement. Leachate and landfill gas collection andtreatment will be necessary for an indefinite period of time. Leachatequantity should be less than in Alternatives SCRV and SRCVT. Modificationsto the remedy would be difficult due to the engineered onsite RCRA-typecell. The State of Michigan supports this remedy. The surroundingcommunity residents also support this remedy,

The estimated capital cost of this remedy is 528,631,300. The totalpresent worth is $29,620,000. The estimated annual 34M cost is $102,000.

Alternative ROF

This alternative provides reliable short and long-term protactlveness bycomplete excavation and offsite removal of landfill wastes. All directcontact and groundwater contamination threats from the landfill arecompletely removed. This remedy also provides onsite or offsite thermaldestruction treatment of all drummed waste in the landfill and, therefore,provides a similar degree of treatment and permanence as Alternative RON.Long-term management of the non-drummed wastes is the responsibility of theoffsite land disposal facility. This remedy will provide adequateprotection of public health and the environment. This remedy will meet theidentified Federal and State ARARs for the landfill.

This remedy can be implemented in approximately two years. As withAlternative RON, this remedy requires complete excavation of landfillwastes, resulting in significant waste handling issues, and requiringconsiderable technical ability and quality control to assure complete wasteremoval. Exposure risks to .the workers and surrounding community stem fromthe significant waste handling and extensive waste excavation. Risks tothe community also exist because of the extensive offsite transportnecessary for approximately 260,000 cubic yards of material. If onsiteincineration is employed, there would be short-term risks from thistreatment. No long-term maintenance activities are required for thisremedy since the offsite disposal facility is responsible for long-termmonitoring. Workers and equipment are readily aviilaolt for this

flROOOOU3

29

alternative, but the large l a n d f i l l capacity needed for this /ol ne :fwaste may present some d i f f i c u l t i e s , "ne 3C3A Land San r e g u l a t i o n s 'ortreatment prior to land disposal may a p p l y , presenting pot e n t i a l sanous;7iolementab1l ity issues, and a d d i t i o n a l costs than configured in the r3.:f no treatment is provided to wastes transported offsite for aisposal ,tnis a l t e r n a t i v e is not preferred r e l a t i v e to CERCLA Section 121 d i r e c t i o n"nere w i l l ' ' <el y pe d i f f i c u l t i e s f i - d i n g a land disposal * a c i l i t y -nMicnigan w i l l i n g to accept the :3B wastes. There may also pe somedifficulty finding a l a n d f i l l to accept the low level dioxin contaminatedwastes. The State of Michigan supports this remedy.

The estimated capital cost of this remedy is $61,399,000. The totalpresent worth is $61,920,000. "he estimated annual OiM cost is $0.

Alternative R^O

This alternative provides reliable short and long-term protection withcomplete landfill waste excavation, onsite thermal destruction of allcombustible materials in an onsite RCRA-type incinerator, onsite dewateringtreatment of non-combustible materials, and disposal, as necessary, oftreatment residuals and untreated materials in an onsite RCRA-typelandfill. The direct contact threat and the long-term groundwater threatare mitigated. Onsite thermal treatment of all combustibles significantlydestroys the toxicity, mooility, and volume of hazardous substances. Thisremedy provides the maximum amount of permanence, and practicallyeliminates the potential for future exposure. This remedy will provideadequate protection of public health and the environment. This remedy w i l lmeet the identified Federal and State ARARs for the landfill.

This remedy will take approximately 5 years to complete and will be verydifficult to implement. Complete landfill excavation and waste sortingw i l l present significant waste handling issues. Considerable technicalability and quality control will be needed to assure complete wasteremoval. Careful design and quality control for building the onsite RCRA-type incinerator and RCRA-type landfill will be needed. Operation of theincinerator will be lengthy and will require careful quality control andskilled operators. Equipment and specialists for onsite Incinerator areavailable, but limited. This alternative will require careful andsignificant coordination with Federal, State and local authorities forenvironmental regulation. This alternative presents exposure risks to theworkers and surrounding community during waste excavation and incineratoroperation. Lonf-term maintenance and operation of the RCRA-type disposalcell should b« routine, and less significant than the O&M in AlternativesSRCV, SRCVT, and RON. Modifications to this remedy would be difficult.The State of Michigan has no comment on this remedy.

The estimated capital cost of this remedy is 566,364,000. Total presentworth is 5130,500,000. The estimated annual O&M cost is $16,742,000.

flRQOGOH

3. landfill Evaluation Summary

1. Overall Protection of -iurnan wealth and the Environment -

"ie Alternatives NA, SR, and SRC do not provide adequate human healthand environmental protection, therefore, are not e l i g i b l e for furtner::ns:carati:n.

Alternative SRCV is configured to provide adequate protection, p u t "r e l i a b i l i t y concerns relative to the containment system for drummed wastematerials makes the protectiveness of this alternative somewnatquestionable.

All remaining alternatives provide reliable protection, although they 1o sothrougn different combinations of treatment, containment, and i n s t i t u t i o n a lcontrols. The greater degree of treatment, the less reliance oncontainment and institutional controls.

2. Compliance with Applicable or Relevant and Appropriate Requirements -

All protective alternatives are designed to attain the applicable orrelevant and appropriate requirements of other Federal and Stateenvironmental laws.

3. Long-Term Effectiveness and Permanence -

Alternative RTO offers the greatest degree of permanent management for thewastes at the site. All wastes wnich can be, are treated, destroying the•naximum amount of hazardous substances at the site. Only wastes whichcannot be treated and treatment residuals are left onsite for long-termlanage'ment of waste.

Alternatives ROM and ROF provide similar degrees of permanent and long-term effective waste management. All drummed wastes are thermallydestroyed, and all remaining wastes are contained in a RCRA land disposalcell which provides effective waste containment.

Alternative SRCVT provides permanent treatment for drummed wastes inconcentrated disposal regions, as well as associated saturated contaminatedsoils. Permanent treatment for twice the volume of waste than inAlternatives RON and ROF is proposed (4,000 drums of waste plus 4,000 drumvolumes of contaminated soil). The remaining wastes are managed with aRCRA cap/slurry wall containment system. Such containment is lesseffective over the long-term for waste containment than a RCRA cell.

Alternative SRCV relies entirely on the RCRA cap/slurry wall containmentfor long-term effectiveness. Drummed wastes, which are not removed, maycause some problems for tht containment system over tht long-term.

flROQOOUS

31

4. Reduction of "oxicity, M o b i l i t y , or /ol jrne -

Alternatives SRCVT, RC.N, 3OF, and 3TD offer treatment *nich prCV'jes-eduction of toxicity, m o o i l i t y , and /ol^me of hazardous suostances is ip r i n c i p a l element.

Altar-ati/e tTD offers the greatest degree :f permanent and s i g n i f i c a n treductipn in toxicity, m o b i l i t y , and volume of the hazardous suostancestnrougn treatment. Large volumes of waste (estimated at over 130,300 cjo-cyards) would be incinerated.

Alternative SRCVT offers thermal treatment for an estimated 3,000 drums(4,000 drums of waste plus 4,000 drum volumes of contaminated soil) or2,000 cubic yards of material. The waste of concern in the landfill ispermanently treated. Landfill leachate would also likely be permanentlytreated.

Alternatives RON and RDF offer permanent treatment (incineration) for anestimated 4,000 drums or 1,000 cubic yards of material. The waste ofconcern in the landfill is permanently treated. Landfill leachate wouldalso likely be permanently treated.

Alternative SRCV does not offer reduction in hazardous substance toxicity,mooility, or volume as a principal element of the remedy. Landfillleachate only would likely be permanently treated.

5. Short-Term Effectiveness -

Alternatives SRCV and SRCVT are most attractive in the short-termeffectiveness respect of time to implement. Both alternatives areestimated to take one year to implement. Alternative SRCV would require nowaste excavation, therefore, no short-term human health or environmentaleffects exist in that sense. Alternative SRCVT would require abovegroundwaste handling of 2,000 cubic yards of material, and would Include adverseshort-term effects regarding the offsite transport or onsite incinerationof this waste.

Alternatives RON, ROF, and RTO would required significant amounts of above-ground waste handling and associated adverse short-term impacts. Allrequire complete landfill excavation (estimated to be 260,000 cubic yardsof material after excavation) with some waste sorting (Alternatives RON andROF to sort drums) to great amounts of waste sorting (Alternative RTO tosort combustible from non-combustible materials). Alternative ROF alsoincludes offsite transport of all wastes from the landfill (estimated at208,000 cubic yards of waste), thus short-term effects exist from muchtruck traffic and some risks to the community exist during offsitetransport. If drums were incinerated off site. Alternative RON wouldinclude short-term adverse impacts from waste transport of an estimated1,000 cubic yards of material. If Alternatives RON or ROF included onsiteincineration, there would be short-term adverse effects from short-termoperation of an onsite Incinerator. Alternative RTO would include adverseshort-term effects from long-term operation of the onsite incinerator.

32

Time to implement for Alternatives R2F, 3:,N, and 3T3 are -esoecti/e:/ 2/ears, 5 years, and 5 /ears.

5. :.m piemen tab il i ty -

Alternative SRCV would be the. easiest to implement of all protectivealternatives oecause it requires no aaoveground waste handling and r e l i e sonly on readily available materials and services. Some quality controlwould, be required in construction. Alternative SRCVT would a d d i t i o n a l l yrequire some landfill intrusive investigation to- identify concentratedareas of drum disposal, and aboveground handling of an estimated 2,300cubic yards of material. Services and materials for this alternativeshould also be readily available. There may be some difficulty i d e n t i f y i n ga compliant offsite RCRA incinerator for the 3,000 drums of material. Ifthe drummed wastes are treated onsite, some careful quality control w i l l oeneeded for building and operating the incinerator.

Alternatives RON, ROF, and RTO require careful quality control in wasteexcavation and sorting. There may be some- difficulty in identifying acompliant offsite RCRA incinerator for the estimated 4,000 drums inAlternatives RON and ROF. Alterative RTO would require some qualitycontrol in building the onsite RCRA incinerator, however, materials andservices should be readily available. Likewise, some quality control forthe potential onsite incinerator in Alternatives RON and ROF would beneeded. There would likely be some difficulty in identifying a compliantoffsite RCRA landfill disposal facility for the large amount of waste in.Alternative ROF (estimated at 208,000 cubic yards of waste). Additionallyidentification of a land disposal facility w i l l i n g to accept the ?B8 andlow level dioxin contaminated wastes would likely be difficult. Materialsand services for Alternative RTO should be available, but the long-termoperation of the onsite incinerator would require significant qualitycontrol and technical skill.

7. Cost - . ....

Alternative RTO is by far the most expensive alternative with an estimatedpresent worth cost of $130,500,000. Alternative ROF is also clearly moreexpensive than tht balance of protective alternatives with an estimatedtotal prtftnt worth cost of 561.920,000.Alternatives R*ON and SRCVT are in the middle range of costs for protectivealternatives, with estimated total present worth costs of 529,620,000 and522,530.000, respectively.Alternative SRCV is at the lower range of costs for protectivealternatives, with an estimated total present worth of $9,700,000. Thecost difference between Alternatives SRCY and SRCVT is an estimated512,830,000. This additional cost provides permanent treatment for a wasteof concern at the site (drummed wastes) and long-term effectiveness for

AROOOO«»7

33

Alternative SRCVT. [t should be noted that a permanent treatment(incineration) for this waste of concern, is not a v a i l a o l e at any 'essercost.

Alternatives wni'ch do not provide adequate protection at the sits naveestimated total :resa.nt worths of approximately $2 m i l l i o n and less.

3. State Acceptance -

"he State of Micnigan w i l l support Alternative RON and prefers AlternativeROF. Alternatives NA, SR, SRC, SRCV, and SRCVT are not supported oy theState of Micnigan.

9. Community Acceptance -

Local community residents support the above State of Michigan position.PRPs for the site support Alternative SRCV, and are opposed to AlternativesSRCVT and RON.

II. Groundwater

A« Alternatives Evaluation

Alternative NA

No public health risks currently exist from the onsite contaminatedgroundwater, since there are no users of this water and migration ofcontaminants to offsite groundwater users is highly unlikely. uowever,this alternative provides no protection against future use of onsitegroundwater and provides no information about the change in groundwaterquality geographically and over time, and the threat this change may poseto public health and environment. This alternative provides no treatmentto reduce contaminant toxicity, mobility, or volume. This remedy is notpermanent. This remedy may not meet the identified Federal and State ARARsfor the groundwater. There are no limitations for use of the shallowaquifer as a drinking water source, and without monitoring, compliance withthe Safe Orinking Water Act MCLs Is unknown. This remedy is not protectiveof public health and tht environment.

NO construction activities art associated with this remedy, therefore,there are n* construction implementabllity issues. This remedy will takeno time to implement. This remedy is not supported by the State ofMichigan.

There are no costs associated with this remedy.

Alternative SRNo public health risks currently exist from onsite contaminated groundwatersince there are no users of this water, and migration of tht contaminantsto current offsite groundwater users is highly unlikely. This alternativeprovides protection to future users of onsite groundwater with deed

34

restrictions that prevent use of this water as a jrjni<ing water source.Enforcement of the deed restrictions should pe imolementaole pecause tnsite is currently under MO'IR ownership and oecause of the low potentialievelooment of site property, "he m o n i t o r i n g component of this,provides information about cnanges in groundwater q u a l i t y geographical! /and over time. If a threat to p u b l i c health and the environment is" posedpy c-.anges in ;roundwater q u a l i t y , it w i l l be identified and a remedialaction plan can oe evaluated. This alternative provides no treatment toreduce contaminant toxicity, m o o i l i t y , or volume other than alterationst.nat -nay occur naturally througn di l u t i o n , adsorption, and biologicaldegradation.

The suspected source (lagoons) for the groundwater contamination will becompletely removed in the lagoon operable unit remedial action currently -niesign phase. Current groundwater contaminants should eventually discnar-eto nearby surface water bodies, resulting in background groundwater q u a l i t yin the currently affected aquifer area. If the discharge of contaminantsto surface water bodies occurs in an environmentally acceptable fashion,this alternative affords a high degree of permanence for groundwaterprotection at the site. This remedy wil l meet the identified Federal andState ARARs for the groundwater at the site. This remedy 1s protective ofpuolic health and the environment.

Deed restrictions and installation of additional monitoring wells can beeasily and quickly implemented. Equipment and workers for this remedy areeasily available. Groundwater wi l l be easy to monitor. Modifications, ifnecessary, could be easily implemented. This remedy is not supported oythe State of Michigan.

The estimated capital cost for this remedy is 524,000. Estimated totalpresent worth is $1,290,000. Estimated annual O&M cost is 5190,000.

Al ternative CT30

The public health and environmental risks are mitigated in this alternativewith groundwater collection, onsite treatment with granulated activatedcarbon, and discharge of tht treatment effluent to Sutternut Creek, suchthat NPOES discharge permit requirements are met. The spent carbon willeventually bt disposed of offsite. This alternative uses treatment toreduce contaminant mobility and volume. This remedy will provide permanentcleanup of tht groundwater by completely removing the groundwatercontaminant!. .Tht reliability of this alternative is high. Thisalternative provides adequate protection of public health and theenvironment. All identified Federal and State ARARs for groundwatercleanup are met by this remedy.

This alternative is quickly and easily constructed. Some technical abilityis required. Equipment and construction workers are readily available.Some administrative coordination to obtain the NPOES permit will berequired. The time of system operation, until tht cleanup goals are met,is estimated to be 15 years. No risks to surrounding community, andnegligible risks to site workers, exist with this remedy. Modifications

ARQOOQI49

35

to this system are relatively easy, "he State of Michigan supports tms-emedial alternative.

"he estimated capital cost tfor this remedy is $325,300. "otal presentwortn is $3,760,300. Estimated annual 3&M costs are $465, CGO.

Public health and environmental risks are mitigated by this alternativewith groundwater collection and offsite treatment and disposal at aPuolicly Owned Treatment Works (POTW). The treatment at the POTW w i l lsignificantly reduce the toxicity, mobility, and volume of groundwatercontaminants. This alternative will provide permanent cleanup ofgroundwatar by completely removing the groundwater contaminants. Thereliability of this alternative is high. This alternative providesadequate protection of puolic health and the environment. All identifiedFederal and State ARARs for groundwater cleanup art met by this remedy.

This alternative is easily and quickly constructed, requiring sometechnical ability. Eauipment and construction workers are readilyavailable. Significant administrative coordination with State regulatoryprograms and the local POTW will be needed. The possibility exists that nolocal PQTW would be willing to accept the site groundwattr. The time ofsystem operation (groundwater pumping) until cleanup goals are met isestimated to be 15 years. Risks to site workers and surrounding communityexist from necessary collection and transport of water. Modifications tothe treatment will be very difficult since the site waste stream is mixedwith others at the POTW facility. The State of Michigan has not supportedthis remedial alternative.

The estimated capital cost for this remedy is $205,000. Total presentworth is $2,550,000. Estimated annual O&M cost Is $330,000.

3. Groundwater Evaluations Summary

1. Overall Protection of Human Health and the Environment -

Alternative NA does not afford adequate protection of human health and theenvironment, and is not eligible for further consideration.

The three regaining alternatives afford adequate protection, although theydo so throuojl different combinations of treatment, engineering, and'-stitutioMl controls.

2. Compliance with Applicable or Relevant and Appropriate Requirements -

All protective alternatives art designed to attain tht applicable orrelevant and appropriate requirements of other Federal and Stateenvironmental laws.

3. Long-term Effectiveness and Permanence -

"4

26

AH protective groundwater alternatives are designed to assure completegroundwater cleanups in an environmentally sound fashion.

4. 'eduction of Toxicity, Mobility, or Volume -

A l t e r n a t i v e s CT30 and CT? provide for collection and the treatment ofcontaminated groundwater, and in that sense provide for reduction in" them o b i l i t y and volume of the hazardous substances. Ultimate land disposal ofthe spent carbon which has collected the hazardous substances inAlternative CTGO, however, 'would yield no reduction in contaminanttoxicity. Treatment of groundwater offsite at a POTW would offer reductionin contaminant toxicity.

5. Short-Term Effectiveness -

Alternative SR requires little/no construction and waste handling,therefore, provides the least amount of adverse short-term impacts of theprotective groundwater alternatives. Alternatives CTGO and CTP both wouldrequire construction, and handling of contaminated groundwater.Alternative CTP additionally would require transport of the contaminatedgroundwater through the community.

6. Implementabll ity -

Alternative SR Is the easiest to implement of the protective groundwateralternatives because it requires little/no construction. Alternative CT?has potentially serious implementability issues relative to locating alocal POTW willing to accept the Forest Waste groundwater.

7. Cost -

Alternatives CTGD and CTP have high range associated costs with estimatedtotal present worths of 53,760,000 and 52,550,000, respectively.Alternative SR is the least costly protective groundwater alternative withan estimated total present worth of 51,290,000.

3. State Acceptance -The State has supported only Alternative CTGO.

9. Community Acceptance -Ho groundwtttr alternative was expressed as preferred by local communityresidents. PRPs for the site maintain no groundwater cleanup is necessaryat this site.

SaECTED REMEDY AND STATUTORY DETERMINATIONS

I. Landfill Soil and Source Material

The selected remedy for landfill soil and source materials is AlternativeSRCVT. This alternative is protective of human health and the environment.

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attains applicable or relevant and appropriate requirements promulgatedjnder Federal and State environmental laws, and is cost-effect!/e.Treatment which permanently and significantly reduces the /olume, tpx ;;••./,and mobility of hazardous substances is a p r i n c i p a l element of tne remedy!ci.nally, this alternative u t i l i z e s permanent solutions to the iax'mumextent practicaole. This alternative represents the pest oalanca :' fefactors *or selecting an appropriate l a n d f i l l -emedy at tne site.

A. Protection of uuman Health and the Environment

Alternative SRCVT provides protection of human health and the environmentwith a comoination of treatment, containment, and institutional controls.Short-term protectiveness is provided with the landfill RCRA cap and deedrestrictions. The cap is a reliable method to alleviate the direct contactthreat from the landfill surface materials to persons entering the site.The long-tern risk of release of landfill waste to the groundwater ismitigated with the cap, slurry wall, and dewatering system combination.This system serves to fully contain landfill wastes. The RCRA cap servesto significantly reduce precipitation infiltration to the landfill,ultimately reducing the potential for generation of landfill leachate. Theslurry wall will fully surround l a n d f i l l source material. The wall keysinto the lower permeability till layer underneath the site. The wall willprevent the possibility of upgradient groundwater from coming into contactw i l l landfill source materials. The wall w i l l contain liquid and solidmaterials Inside the landfill, and the dewatering system will activelycollect any liquids (leachate and liquid wastes released from drums) i n s i d ethe contained system. Collected liquids w i l l be properly treated anddisposed of. The groundwater monitoring system w i l l identify if a releaseoutside of the containment system (in the case of failure) has occurred.

In addition, removal and treatment of concentrated areas of drummed wastew i l l ensure the reliability of the containment system and provideslgnificact long-term effectiveness.

The short-term Impact of limited landfill excavation and onsiteconstruction are manageable and can be reasonably accomplished in anenvironmentally sound fashion. Likewise, the offsite transport or onsiteincineration of tht estimated 2.000 cubic yards of material presentmanageable short-term Impacts.3. Attainment of Applicable or Relevant and Appropriate Requirements(ARART—"———————————————

Alternative SRCVT will meet all ARARs of Federal, and more stringent Stateenvironmental laws. See discussion below.

C. Cost-Effectiveness

This alternative affords a high degree of effectiveness by providingprotection against direct contact threats and a threat of releases to thegroundwater. The containment portion of this remedy will be reliable Inthe long-term, as concentrated areas of wastes, which may compromise the

5R000052

containment system if left in place, ar? removed and permanently treated.Al t.Hougn Alternative SRCV provides i d e n t i c a l containment of 'andf.ill wastesand Has an estimated total present worth of 53,700,000, Al t e r n a t i v e S3CVTwit.H an estimated total present «ortn of $22,530,300 is the cost-effectivea l t e r n a t i v e . 3otential future costs with Alternative SRCV are !i< e l y ifconcentrated drummed wastes cause containment failure. The additional costof Altarna::/e 3RCVT provides pemanent treatment of drummed waste insuringfe "itegnty of tne containment system. This degree of treatment :annot5e gained tfor any lesser costs. The wastes of most concern in thel a n d f i l l , due to their toxic, mooile nature, are treated.

Alternative NA, SR, and SRC are less costly than Atlernative SRCVT,nowever, none of them provide adequate public health and environmentalprotection. Future costs are likely with all of these remedies. None ofthese remedies provide a cost-effective solution to the proolem.

Alternative RON provides treatment similar to Alternative SRCVT. Lesswaste is treated in Alternative RON since saturated soils are not treatedbut complete landfill excavation insures locating and removing all drums.The containment system is more secure, and the estimated total presentworth ($29,620,000) is a higher cost than Alternative SRCVT. Short-termimpacts and implementability issues are, however, greater than AlternativeSRCVT. The greater cost is due primarily to more sophisticatedcontainment. The containment, however, is for less mobile wastes, sincedrummed wastes are removed. The additional long-term benefits gained inAlternative RON are not commensurate with the additional cost for thisremedy.

Alternatives ROF and RTD require significantly greater costs (estimatedtotal present worths of $61,920,000 and 5130,500,000, respectively) andsignificantly greater implementability issues than Alternative SRCVT,without commensurate gains in overall effectiveness.

0. Utilization of Permanent Solutions and Alternative TreatmentTechnologies to the Maximum Extent Practicaori"

„- "*5"' :''

Alternative SRCVT focuses on providing permanent and significant treatmentof the wastes of concern (drummed wastes) at the site. Identification,excavation, and treatment of these wastes can be practicably done. Thevolume of wastt to bt handled is relatively small- 2,000 cubic yards.Alternatives which provide greater degrees of permanence presentsignificant waste* handling and Implementabil ity issues which render suchalternatives not practicable. All of the more permanent remedies requirecomplete landfill excavation and above-ground management of approximately260,000 cubic yards of waste. Time frames associated with more permanentalternatives are 2 to 5 years, as compared with Alternative SRCVT, which isestimted to take one year to implement. Alternatives which do not providesource treatment (Alternatives NA, SR, SRC, SRCV) afford little permanence.

No alternative is widely accepted by all parties involved in tht site. TheState and local community, as well as the PRPs oppose Alternative SRCVT.Their issues with the selected alternative are very different (set

flR'000053

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Responslveness Summary). Such lac< of support presents 'mplementaoi ', > ty;ssues for this alternative.

por "reat.ment as a 3"incipal -Tement

Concentrated areas of wastes of concern in the l a n d f i l l are permanentlytreated (incinerated) to reduce the toxicity, m o b i l i t y , and /olume of tneHazardous substances. The preference for treatment as a p r i n c i p a l elementis met with Alternative SRCVT.

2. Groundwater

The recommended remedy for selection and implementation for the groundwataris Alternative SR. This alternative is protective of human health and tneenvironment, attains Federal and State requirements promulgated underenvironmental laws that are applicaole or relevant and appropriate, and iscost-effective. Treatment solutions which permanently and significantlyreduce toxicity, mobility, and volume of hazardous substances are not aprincipal element of of this groundwater remedy. This alternative doesprovide a permanent solution to the groundwater contamination. Thisalternative represents the best balance among the factors for selecting anappropriate groundwater remedy at the site.

A. Protection of 'Ainan uealth and the Environment

.'Jo public health risks currently exist from onsite contaminated groundwatarsince there are no current users of this water, and migration of thecontaminants to current offsite groundwater users is highly unlikely. "HISalternative provides protection to future users of onsite groundwatar *itndeed restrictions that prevent use of this water as a drinking watersource. The monitoring component of this remedy provides information aboutchanges in groundwater quality geographically and over time. If a threatto puolic health and the environment is posed by changes in groundwaterquality, it will bt identified and a remedial action plan will beevaluated. Modelling information has indicated that a current onsitecontamination will discharge to offsite groundwater at concentrations thatare well within all remedial action goals.

The suspected source (lagoons) for the groundwater contamiantion will becompletely removed in the lagoon operable unit remedial action currently indesign pJUtt.. Current groundwater contaminants should eventually dischargeto nearby surface water bodies, in an environmentally sound fashionresulting In background groundwatar quality in the currently affectedonsite aquifer area.The monitoring component of this remedy will include quarterly sampling andanalysis of groundwater during the first S years. Tht program would thenbe reevaluated to determine if changes in analyses and sampling frequencyare necessary. Samples will be analyzed for CLP organic and Inorganicparameters and for conventional parameters such as chloride, sulfate,nitrate, nitrite, specific conductivity, and alkalinity.

.-0 -

Annually, the quarterly results of the s a m p l i n g and anal/sis program' wi";e averaged and compared to the groundwater remedial action goals. At fesite boundary (monitoring well HOS. ."W85-IS and MW85-2S;, if :n an averageannual pasis, the quality of groundwater is greater than ''CLs, exceeding3l i f e t i m e Health advisories, exceeding levels for noncarcinogenic * e a l t neffect :r:tact'on (pased on reference doses) or exceeding a l i f e t i m e cancerrisx range of 13"^ to 10"'; or offsite, upgradient of tne wetlands,(monitoring well nos. MW86--IS, MW36-3S, and HW86-2S) if :n an averageannual basis the quality of tire groundwater is greater than Federal AmoiantWater Quality Criteria or State of Michigan Surface Water Quality G u i d e l i n eLevels for the Protection of Aquatic Life, a plan for further groundwatarremedial action will be evaluated.

The minimal construction and operations of this alternative present noadverse snort-term impacts.

3. Attainment of Applicable or Relevant and Appropriate Requirements

Alternative SR will meet all ARARs of Federal, and more stringent Stateenvironmental laws. See discussion below.

C. Cost-Effectiveness

This alternative affords a high degree of effectiveness by providingprotection against use of onsite groundwater with deed restriction andassuring the contaminants discharge to offsite areas in an environmentallysound fashion, (1e., consistent with the groundwater remedial actionsgoals) with the monitoring program. The estimated total present worth costof 51,290,000 is on the low range of the alternatives developed in the FS.The no.action alternative, with a total present worth of SO, is notacceptable as a cost-effective alternative because it does not provideadequate public health and environmental protection.

Alternatives CTGO and CTO Include active construction and waste handling,and have respective estimated total present worth costs of 53.760,000 and52,550,000. The additional adverse short-term impacts of waste handling,and additional costs associated with these alternatives are not necessaryto provide public health and environmental protection. These alternativesare not cost-effective.

0. Utilization of Permanent Solutions and Alternative TreatmentTechnologies to the Maximum Extent Practicable

Alterntaive SR provides a permanent solution to the onsite contaminatedgroundwater problem. Over time, through dilution and adsorption, the.minimally contaminated onsite groundwater should reach background levels asthe contaminants discharge to the nearest surface water body in anenvironmentally sound fashion. Since tht source of this groundwatercontamination (lagoons) is being completely removed 1n the lagoon operableremedy, no future contribution to this contaminant plume will occur.

Alternatives CTGO and CT? also provide permanent remedies, and do sothrough treatment processes. The actual amount of Hazardous suostancestreated in these remedies, however, is very small, 'hese remedies alsopresent impl ementabi 1 i ty issues and adverse short-tern impacts. Thea d d i t i o n a l cost and impl ementabi 1 ity issues, with no gain in o v e r a l lprotacti /eress or permanence, make selection of these alternatives notpracticaole.

xgpce *or "reatment as a Principal -!ement

The groundwater Alternative SR does not use treatment as a principalelement. Use of treatment provides no gain in overall protectiveness orpermanence for the groundwater cleanup, therefore, is not worthwhile . T^eoverall site remedy, including the landfill cleanup, however, does providetreatment as a principal element.

State Issues

The landfill soil and source materials, and groundwater operable unitrecommended alternatives are both opposed by the State of Michigan. Theprotection provided by landfill operable unit Alternative SRCVT is notviewed by the State as adequate. The groundwater Alternative SR is notacceptable to the State. The State maintains that the releases to theonsite groundwater merit active groundwater cleanup. The State of Michiganposition and the U.S. EPA response is discussed in detail in theResponsiveness Summary.

ATTAINMENT OF APPLICABLE Of RaEVAMT AND APPROPRIATE REQUIREMENTS OFEHVIROHHENTAL LAirfS

1. Landfill Soil and Source Materials ARARs

Alternative SRCVT is designed to meet all applicable, or relevant andappropriate requirements (ARARs) of Federal, and more stringent. Stateenvironmental laws. Tht Federal ARARs include the Resource Conservationand Recovery Act (RCRA). (42 USCA Section 6901 et seq and 40 CFR Part 260-271), the Clean Water Act (40 CFR Parts 122. 12T, and 131), the SafeDrinking Water Act (42 USCA Section 300(f) 'et seq and 40 CFR Part 141), theClean Air Act (42 USCA Section 7401 et seq and^O CFR Parts 50 and 51), andthe Occupational Safety and Health Administration Act (40 CFR 1910).Potential SUtt ARARs include the Michigan Hazardous Waste Management Act(Act 64), tht Liquid Industrial Waste Removal Act (Act 136), the AirPollution Act (Act 347). the Mineral Well Act (Act 315), and the WaterResources Commission Act (Act 245).

A. Federal Resource Conservation and Recovery Act

RCRA regulations will bt applicable to tht wastt removed fro* tht landfillfor incineration treatment. All such material will bt considered to behazardous waste as defined in the RCRA regulations, 40 CFR Part 261"Identification and Listing of Hazardous Wastes", unless proven otherwise,

flRGQ0056

;r unless the waste is "egjlitad :/ another s t a t u t e S^CH as t-eControl Act.

A*tar --emoval and treatment/disoosal of jrum *astes and cpnta.minated s o i l s ,t.na rwo 'andfill area w i l l oe closed. 3ecause disposal of Hazardous «astaat t-e "O l a n d f i l l pccured prior to the effective date of t.ne ?C.RA-egulat'pn, t-e C.->A closure regulations are not aoolicaple. ^wever, :-e/ara considered -a'evant and appropriate, "he ^i^ant and appropriaterequirements of RCRA Suotit'e C regulations, w i l l :e met 2y the selectedremedy.

closure and post-closure requirements for all hazardous wastemanagement facilities are outlined in 40 CFR Subpart S. Section 264.310 :fRC3A Subpart .N specifies the performance-based requirements for a cover atfinal landfill closure. The cover system in Alternative SRCVT wi11 be acap as prescribed in RCRA guidance and will comply with RCRA regulations."he cap w i l l minimize migration of liquid through the landfill, functionwith minimum maintenance, promote drainage, minimize erosion, accommodatesettling, and 5e less than or equal to the permeability of natural subsoilspresent.

After closure is completed, the substantive monitoring and maintenancepost-closure requirements contained in Section 264.117 through 264.120 ofSubpart 3 will be conducted. The facility will be closed according to thestandards in Subpart G Section 264.111 - Closure performance standards.After the closure activities have concluded, a survey plat, as prescrioedin Subpart 3 Section 264.116, indicating the location and dimensions of thedisposal area will be submitted to the local zoning authority, or to theauthority with jurisdiction over local land use, and the RegionalAdministrator (Michigan State Director).

The drum wastes and contaminated soils removed from concentrated regions ofthe landfill prior to closure must be properly disposed of ordecontaminated as required in Subpart G Section 264.114. If incineratedoffsite these wastes will be staged and repackaged onsite, and transportedoffsite for incineration at a RCRA treatment facility operating incompliance with 40 CFR Sections 264.340 through 264.351. The excavatedwaste will also be handled as regulated by Part 262 - Standards Applicableto Generators of Hazardous Waste, and Part 263 - Standards Applicable toTransporters of Hazardous Waste. If incineration is onsite, it mustoperate in compliance with tht technical requirements of Subpart 0 Sections264.340 through-264.351.

3. Michigan Hazardous Waste Management Act (Act 64)To the extent that Act 64.1s more stringent than the Federal RCRAregulation, Act 64 will bt followed.

Rules 301(4) and 304 (1) (c) of Act 64 require that a gtntrator ust alicensed transporter or gentrator-owntd licensed vehicle for transport ofhazardous waste offsite.

AR000057

-ij

:egarding mani f?sti-g, a 'H:--:aH lapa-t.-ent : •" '.'at^r?: ^esc^rtss -a--•'?:•.w i l l pe used and ma i fed to 'CNR as ^tli-ed -H "jie :;4, -V*s -?:a-r-:-sa of the hazardous waste nu.moer wi ;' pe 'oi':*ed as :u:l-ned -H -:,;a::A'>:, ICSUXe) , and 2:6.

<as:as a c c u m u l a t e d :nsite "'or 'ass "."an 30 :a/s -jSt :e itprec ' *:pnta:-e-s «•',' saco"dary rcntai-rent eq u i v a l e n t to tnat of a pen-ttad• a c i l - t y *n:er i-3 3FR 254.175. Containers must pe 'apelad witn feHazardous waste numoer.

"he following rules for transporter standards w i l l apply under Act 54;requirements for transporter business anq vehicle licenses (Rule 403 and4C6), use of Michigan manifest form (Rule 409(1)) and l i a b i l i t y insurance(Rule 711).

Transporters must comply with generator requirements when they mix smallquantities (Rule 401(3) and 405 (2)). Mixing, combining, and comminglingof managed hazardous waste (greater than 1000 '<g) is prohibited withoutapproval from the MONR.

The following transporter vehicle requirements will be followed: 3ule 106/enicle labeling, operation and maintenance requirements, andidentification numbers; compliance with Act 300 Michigan Vehicle Code;Act 207 Fire Prevention Act; Act 131 Motor Carrier Safety Act; and theHazardous Material Transport Act (Rule 408 (1)), and Rule 408 Provisionsfor a Fire Marshall Inspection.

Rule 410 of Act 64 outlines the procedures to be 'ollowed in the event :fwaste discharge during transport.

Rule 409(2) requires transporters to document communications withgenerators on the manifest, if waste cannot be delivered.

Relative to landfill closure provisions, Act 64 Rule 619 specifies closurestandards, including a minimum cover requirement, and requirements forventing which will bt followed.

C. Michigan Liquid Industrial Waste Removal Act (Act 136)

This Act rtojulrts tht ust of a licensed liquid industrial waste hauler toremove any Industrial liquid wastes offsite, similar to tht requirements ofRCRA Part 2t3«* To tht extent these requirements are more stringent thanRCRA, they will bt complied with for handling offsiti disposal of liquidwaste froa tht landfill.

0. Federal CTean Air Act

The Clean Air Act (CAA) identifies and regulates pollutants that could btreleased during earth-moving activities associated with tht partialexcavation and slurry wall construction and potential onsite incinerationof SRCVT. Tht CAA Section 109 outlines tht criteria pollutants for which-National Ambient A1r Quality Standards have been established. CAA Section

AROOQQ58

12 ;dent1f1es ;ollutants *";f w n i p i t-ere a-? -o a p p l - c a p ' e -^p;antjality Standards, those suastancas - e g u l a t a d -r-^er tne r2^e-ji '.'at-m i s s i o n Standards for -azar-o,,s -oll^tants. ";-e :±A s an :;AR ande g j l a t i o n s standards w i l l :e complied wi tn d u r i n g imglementafpn ;•

. '":--:a" -•- VTJt-:n Act 'ict ?4g)

:HTS Act, t.me Micnigan Air Quality J'yision, through Ru l e 901,axercises its autnority to ensure that a parson does not cause or permitthe emission of an air contaminant in quantities that will cause,"injurious effects to human health or safety, animal life, plant life orsignificant economic value" or "unreasonaole interference with thecomfortable enjoyment of life and property." This Act is an ARAR which "asmore stringent emissions controls for air contaminants than the FederalClean Air Act, and the substantive technical requirements will be compliedwith during landfill excavation and potential onsite incineration.

F. "ederal Occupational Safety and health Administration Act "3SHA)

*he selected remedial action contractor must develop and implement a healthand safety program for his worxers, if such a program does not alreadyexist. All on site workers must .meet the minimum training and medicalmonitoring requirements outlined in 40 CFR 1910. OSHA will also becomplied with wnen implementing the groundwater remedial activity.

2. >oundwater/Surfaee '..'ater ARARs

Alternative SR is designed to meet all applicable, or relevant andappropriate requirements of Federal, and more stringent, Stateenvironmental laws. Three groups of Federal environmental standards andcriteria are considered ARARs for the groundwater at the FWO site: Safe3rin*ing w'ater Act Maximum Contaminant Limits (MCLs), RCRA GroundwaterProtection Standards, and Clean Water Act Ambient water Quality Criteria.These are ARARs for groundwattr protection underneath tht landfill for thelandfill operable unit remedy, as well as for tht affected groundwattr inthe groundwater operabVe unit remedy* The CUA regulation is likewise anARAR for protection of surface water relative to tht landfill andgroundwattr operable unit remedies.Potential SUtt ARARs for tht regulation of groundwater at tht site includethe MIchffM Ulttr Resources Commission Act and the Mineral Well Act.Michigan environmental law regulating surface water includes tht MichiganWater Resources Commission Act.A. Federal Groundwater ARARsMaximun Contaminant Levels established undtr tht Safe Drinking Water Actare ARARS at this site. MCLs art tht maximum contaminant concentrationsallowed in a regulated public water supply. These levels apply at thtpoint of distribution ("at tht tap") to public water systtns having atleast 15 service connections or regularly serving at least 25 individuals.

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Levels are based on a :-emici's t o x i c i t y , t - e a t a o i l : t y ; - " c ' u d i n g ::3:considerations), and a n a l y t i c a l l i m i t s o* detection.

MCLs are relevant and acprcor-ate at ^D *or groundwatar p r o t e c t i o n :eci,i~fa a:uifers underneath the site are defined as d r i n < i n g *atar a p u i f e r s ,ana *CL5 are t-e a.nforceaol e drin<ing water standard ""or p u o l i c «atars-opi'as. Si-ca MCLs apply to water at the point of use, these l e v e l s areappropriate szr estaol i sni ng *ater quality in the d r i n < i n g water asui^a'-'jat tne site. 3roundwater tapped for drinking water generally *as m i n i m a lor no treatment. These standards w i l l be applied to the groundwater itssl'to ensure safe levels in the groundwater underneath the site.

The groundwater cleanup levels are also consistent with MaximumConcentrations Limits or health based Alternate Concentration Limits underRCRA Subpart F. Specifically, the protection provided for groundwater inthe site remedies is consistent with RCRA Subpart F Section 264.100.Corrective action program, which serves as the ARAR. The point ofcomollance for groundwater protection is established onsite. For thegroundwattr plume to the east, the point of compliance is at monitoringwell Nos. MW85-1S and MW85-2S. For t-» ''ndflll, the point of complianceis at the physical landfill perimeter.

3. Federal Surface Water ARAR - Ambient Water Quality Criteria 'AWQC)established under the Clean Jater Act————————

The CWA Is an ARAR at this site since site groundwater eventuallydischarges to the surface water body (wetlands) east of the sitt. "heAWQC are established for protection of freshwater aquatic organisms. -WQCwill be met at the point the groundwater discharges to the closest surfacewater body. Monitoring shallow groundwattr, upgradient at the surfacewater body, will assure compliance with AWQC before it discharges to thewetlands.

C. Potential State Groundwater ARARs

1. Water Resources Commission Act (Act 245)

Act 245 Is not a groundwater ARAR at this site. Its purpose is to preventdischarges into tht groundwater. U.S. SPA is not discharging into thegroundwattr, hence tht Act Is not applicable.

Similarly*, Act 24S is not relevant or appropriate to establishing cleanuplevels at*tht sitt. There are no promulgated regulations U.S. EPA canconsider In sttting cleanup standards. Additionally, the objectives of theAct and rules, which art to define and limit discharges, vary significantlyfrom U.S. EPA's objectives to cleanup tht site.ii. Mineral Well .Act (Act 315)

Act 315 and the Administrative Rules require that test wtlls bt permitted,constructed properly, recorded, and properly plugged upon abandonment.This Act is an ARAR and treatment of all test wtlls will bt dictated by it.

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Stata Surface Water A3AR - 'later Resources Cprniss'pn ict '-ct ?A;

Act 145 establishes surface water standards, "he more stringentp r o m u l g a t e d State standards, relative to the C'WA AWQC, w i l l oe met cor an/discharges to t.ne nearest surface water discharge point.

ry Discussion

Considering the various evaluation factors in SARA Section 121 (b) and theNational Contingency Plan, Alternative SRCYT for the landfill andAlternative SR for the groundwater offer cost-effective solutions to thecontaminant proolems onsite. 3oth remedies satisfy Federal and StateARARS . : : . ; ,Alternative SRCVT provides adequate protection of human health and theenvironment, and utilizes treatment, which permanently and significantlyreduces toxicity, mobility, and volume of hazardous substances, as aprincipal element. This alternative utilizes long-term onsite managementof some wastes in a reasonable fashion, and presents no major engineeringimplementabi1ity issues.

Alternative SR provides adequate protection of human health and theenvironment. The minimal groundwater contamination problem is handled witha deed restriction/monitoring alternative which incurs little cost and iseasily implemented.

OPERATION AMD HAIMTENAMCE

The recommended landfill Alternative SCRVT requires some annual operationand maintenance (O&M). Maintenance of the landfill cap and slurry wallw i l l be, required periodically over time. Operation of a collection andtreatment system for landfill leachate and gas will be needed over time.Maintenance of a site fence will be needed. Operation of a groundwatermonitoring program to identify potential groundwater releases from theslurry wall/cap containment system will be required over time.

The recommended groundwater remedy. Alternative SR, will require operationof a groundwtter sampling and analysis monitoring program. Over time it isanticipated that tht monitoring program can be abandoned as groundwattrcontamination attenuates and is no longer detected, due to dilution andadsorption.

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1.0 INTRODUCTION

This report documents activities performed during the field investigationactivities at the Forest Waste Superfund Disposal Site in Otisville, Michigan.The project was conducted for the U.S. Army Corps of Engineers (USAGE), OmahaDistrict, under contract No. DACW 45-90-C-0030. -,

The field work was performed in accordance with approved plans submitted priorto field investigation activities. Those documents were:

o Final Quality Control Plan.o Final Site Safety Health and Emergency Response Plan (SHERP).o Addendum No. 1 to the SHERP Boundary Air Monitoring.

Technical memoranda were prepared detailing the field procedures presentingthe data and noting any deviations from approved plans.

Detailed technical memos are in the sections as follows:

Section 1 Landfill Boundary DeterminationSection^ Soil Gas SurveySection 3 Slurry Wall Borings - Drilling and Sampling ProceduresSection 4 Piezometer and Monitoring Well InstallationSection 5 Slug Testing Field Procedures and Data AnalysisSection 6 Groundwater SamplingSection 7 Trench ExcavationSection 8 Drum Selection and Sampling -..--Section 9 Landfill Drum EstimationSection 10 Perimeter Air MonitoringSection 11 Quality Control Summary Report

1.1 Site Background Summary

The Forest Waste Site is in the rural southeast corner of Section 8, ForestTownship (T9N, R8E), Genesee County, Michigan. It is 20 miles northeast ofFlint and 2 miles northwest of the City of Otisville.

The site is generally flat except for slight irregularities in the landsurface that indicate previous waste disposal. Vegetation consists of grassand weeds, low shrubs, and a few scattered trees. Land surrounding the siteis approximately 50 percent agricultural and 50 percent undeveloped (woodlandsand wetlands). Butternut Creek flows past the southeast corner of the site,continuing southwest and discharging into the Flint River.

Physical features of the site include a landfill and formerly, nine lagoonswith a surface area of 1 acre that have now been remediated with all soilsexceeding action levels removed from the site. The landfill area occupiesapproximately 11 acres of the 112-acre property. It is covered with vegeta-tion and native soil, although refuse and rusty drums are exposed in someplaces.

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A Remedial Action Master Plan (RAMP) for RI activities was completed inJanuary 1984. On-site RI activities proceeded in three phases from 1334 to1987, and the final RI report was issued in August 1987. RI activities wereaccomplished by CH2M Hill. These reports present a more detailed sitedescription and a description of previous work performed.

A Phased Feasibility Study (PFS) addressing the lagoons as an operable unitwas completed in April 1986. In the PFS, remedial actions were considered forthe lagoon liquids, sludges, sediments, and soils that represent an unaccept-able public health risk through direct contact exposure. The ROD for lagoonremediation was signed on June 30, 1986.

Donohue & Associates, Inc. (Donohue), performed field investigation activitiesbetween April 16, 1990 and June 20, 1990. The goal of the field investigationwas to lead to treatability studies and design and implementation of finalcleanup. A landfill boundary was determined, a drum estimation was completed,an estimated volume of contaminated soil was calculated, and treatabilitystudies are beginning.

2.0 FIELD ACTIVITIES

The report briefly summarizes the following activities:

1. Conduct an electromagnetic geophysical survey to determine the locationof the landfill boundary.

2. Conduct shallow confirmation soil borings around the landfill to verifythe location of the landfill boundary.

3. Conduct deep soil borings equally spaced around the landfill to charac-terize soils for use in designing a slurry wall.

4. Install piezometers along the proposed slurry wall to collect groundwaterelevation information.

5. Conduct a soil gas survey to determine location and relative concentra-tion of volatile organic compounds (VOC) in the landfill area.

6. Install groundwater monitoring wells to determine the presence and con-centration of contaminants in the groundwater.

7. Excavate trenches, and remove and overpack drums to determine locationand approximate number of drums in the landfill.

8. Collect samples from drums to determine the types and concentrations ofdrum contents.

9. Collect leachate/groundwater samples from trenches to determine the typesand concentrations of contaminants in the landfill.

10. Collect soil samples from trenches to determine type, concentration, andextent of contamination associated with the drum contents.

II

2.1 Landfill Boundary Determination . •

An electromagnetic terrain conductivity survey was conducted along the peri-meter of the landfill from April 21 to April 23, 1990. The purpose of thesurvey was to delineate the aerial extent of the landfilled area and to aidein placing the landfill boundary confirmation borings. Additional electro-magnetic: terrain conductivity data were collected in two area? in the proposedtrench excavation locations to provide additional information as to the extentof buried drums, and in an area to the north of the hanger along the east haulroad to.delineate the limits of waste reportedly disposed of outside of themajor landfill area. :

Twenty landfill boundary confirmation borings were conducted to verify thelimits of the landfill boundary delineated during the electromagnetic survey.The technical memorandum in Section 1 discusses the equipment and fieldprocedures and results of the landfill boundary investigation.

2.2 Soil Gas Survey

A soil gas survey was performed to assess the areal extent of volatile organiccontamination in the near surface. Section 2 discusses procedures and equip-ment for the investigation.

2.3 Slurry Wall Borings - Drilling and Sampling Procedures

Exploratory soil borings were drilled and sampled at the Forest Waste DisposalSuperfund Site from May 3 through June 2, 1990. Fourteen slurry wall boringswere drilled along the proposed slurry wall trench alignment, which surroundsthe abandoned landfill area. These borings were advanced to define thestratigraphy in the vicinity of the landfill and assist in the definition ofthe proposed design depth of the slurry wall, and to investigate for soil andgroundwater contamination. Three additional landfill borings were drilled andsampled within the landfill boundary to better define the stratigraphy beneaththe landfill. Figure 1 'shows the locations of the geologic cross-sections.Site stratigraphy is shown on Figures 2 through 5. Figure 6 shows the UnitedSoil Classification System (USCS) for depicting the subsurface. Interpreta-tions were made based on field observations and not on geotechnical analyses.As seen on the figures, there are areas which do not correlate well. Chemicalsampling was not included in these three borings. The memorandum in Section 3summarizes the drilling and sampling procedures used during the slurry walland landfill boring program.

2.4 Piezometer and Monitoring Well Installation

Four polyvinyl chloride (PVC) piezometers and four stainless steel monitoringwells were installed at the Forest Waste Disposal Superfund Site. For theproject, the term piezometer is reserved for wells constructed of PVC withvariable screen lengths emplaced between a surficial facial till and a lowersilty clay and/or till aquiclude. The term monitoring well is used for wellsconstructed of stainless steel for the purpose of groundwater chemical

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sampling. This terminology is consistent with project plans. The memorandumin Section 4 summarizes the drilling and well installation procedures, to noteany problems encountered, and to explain any deviation from project plans.

2.5 Slug Testing Field Procedures and Data Analysis

Hydraulic conductivity testing (slug testing) of all newly installed wells atthe Forest Waste Disposal Site were conducted on June 4 and 5, 1990. Slugtests were performed to determine aquifer hydraulic conductivity at the moni-toring points upon completion of well development. Section 5 summarizes theprocedures and results of the data analysis.

2.6 Groundwater Sampling

Groundwater sampling at the Forest Waste Disposal Site was performed onJune 20 and 21, 1990. Four polyvinyl chloride (PVC) slurry wall piezometersand four stainless steel groundwater monitoring wells installed during thefield investigation were sampled. Section 6 summarizes sample collection andanalyses.

2.7 Trench Excavation

The landfill trench excavation activities at the Forest Waste Disposal Sitewere conducted from May 3 to May 24, 1990. Ten trenches were excavated todetermine the location and approximate number of drums within the landfill andto assess the extent and character of soil contamination, groundwater, andleachate. One thousand and three drums were removed from ten trenches. Fivehundred drums were overpacked and placed in the drum staging area forsampling. The 503 drums spoiled were backfilled into the trenches. A totalof 702 feet of trench was excavated. Section 7 summarizes soil intrusiveactivities for 10 trenches.

2.8 Drum Selection and Sampling

« T e n trenches were excavated at the Forest Waste Disposal Superfund Site toassess the location and approximate number of drums within the landfill. Atotal of 500 drums were removed, logged, and overpacked at the time of excava-tion. Fifty of the 500 drums (10 percent) removed from the landfill and over-packed were sampled in the drum staging area to obtain a preliminarycharacterization of the drum contents. The memorandum in Section 8 summarizesthe selection process of drums to be sampled and drum sampling techniques.

2.9 Landfill Drum Estimation

« Trench excavation activities at the Forest Waste Disposal Superfund Site wereconducted to assess the location and approximate number of drums within theabandoned landfill. One thousand and three drums were removed from the10 trenches. Five hundred drums exhibiting sufficient structural integritywere overpacked and placed in the drum staging area for potential sampling.The remaining 503 drums spoiled were backfilled into the trenches. Trenchlogging during excavation documented the location of each drums as they were

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removed from the trench. The location of drums that remaired insidewalis, and drums visible at the surface or exosurface, were also recorded. The estimation of "Spresent in the landfill was based upon the applicationestablished during trenching and rebate? adja ent areavisible in the trench sidewalis, exposed at the surfa« f * '" ^and the relative configuration and intensitv of%h» 9 3craPin9'drum disposal area. The memorandum in Section 5 c magnetlc an°^ly of eachestimation procedures, including the estimation 8"!""lz" th- »«ill drumoutside the trench excavation an'd the inte^a on o the ^98f^PA^ ^^ "*data. The approximate volume of contaminated =nii magnetometryexcavated trenches and adjacent areas ScIuJjna jJ "" eStimated Usin9 *heused to, calculate the estimated number of dru^sa? thj'slt'ir''' drUm denSUl/

2-10 Perimeter Air Monitoring

Perimeter air monitoring was performed durinq trenchi™ , , . • • .intended to justify possible trench excavation or^n aCtlVlties' ™^ «assions. Section 10 details the dates, InlT s, and' results"

2'Ll Quality Control Summary Report

The Quality Control Summary Report

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TECHNICAL MEMORANDUM

DATE: September 25, 1990

TO: David Shultz, Project Manager

FROM: Dave Richardson, Donohue GeologistDoug Graham, Donohue Environmental EngineerDave Rogers, GZA Geological EngineerPeg Bastien, PEER Engineer

SUBJECT: Trench ExcavationForest Waste Disposal Superfund SiteOtisville, MichiganDonohue Project No. 17617.340

TNTRODUCTION

The landfill trench excavation activities at the Forest Waste DisposalSuperfund Site were conducted from May 3 to May 24, 1990. Ten trenches wereexcavated to determine the location and approximate number of drums within thelandfill and to assess the extent and character of soil contamination, ground-water, and leachate. One thousand and three drums were removed from tentrenches. Five hundred drums were overpacked and placed in the drum stagingarea for sampling. The 503 drums spoiled were backfilled into the trenches.A total of 702 feet of trench was excavated.

The scope of work stated that trenching would be complete when either500 drums were overpacked or 750 linear feet of trench was excavated. Fivehundred drums were overpacked and 702 feet of trench was excavated in tentrenches. Due to the number of drums encountered, Trenches 5, 8, and ° werenot excavated the entire length of the trench specified in the scope or ork.Drum quotas were established per trench to prevent the number of drums over-packed from exceeding 500. This limited further trenching at Trenches 5, 8,and 9. The purpose of this memorandum is to summarize the equipment andprocedures used during trenching, drum removal and drum overpacking, and todescribe the information collected during each trench excavation

TRENCHES

Trench Locations

The trench locations were selected based on the 1986 magnetic gradientgeophysical data collected by the U.S. EPA Region V. Electromagnetic (EM-31)geophysical data collected by Donohue & Associates as part of the site inves-tigation were also used to verify the proposed trench excavation locations.The magnetic geophysical data distinguished anomalies within the landfill thatindicated areas of high metallic content assumed to be associated with drums.The magnetic anomalies were used in conjunction with the electromagnetic data.and visual observations of drums at the surface to orient the trenches and

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Iprovide a representative cross section of drum distribution within themagnetic anomalies. Trench excavation locations are presented on Figure 1.The following trench locations were deleted or re-oriented from that shown onFigure 3-4 in the Field Investigation Plan (FIP);

_ i. Trench 1 was not excavated because it was located in the middle of theI haul road that leads to the decontamination pad and entrance to the™ landfill work zone.

12. Trench 2 was moved 25 feet to the north to provide better coverage ofanomalies detected during the electromagnetic survey.

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3. Trench 4 was rotated 90 degrees and extended in length to provide coverageof drums visibly protruding from the surface and to position the trenchalong the long axis of the magnetic anomaly.

4. Trench 10 was moved approximately 25 feet east to avoid an area excavatedduring an earlier investigation and to provide coverage of drums visiblyprotruding from the surface.

Table 1 presents the site grid coordinates and elevations of the four cornersof each trench. The trenches confirmed the geophysical data in that the drumlocations and drum density correlated with the magnetic anomaly shape andintensity, except for Trench 2 which did not contain drums. Trench 2contained municipal garbage with pipes, bedsprings, cable, and 5-gallon and1-gallon pails.

Trench Preparation .;

The trench run-off control grading for seven trenches (2, 3,4, 6, 8, 9,and 11) was prepared by May 14, 1990. The run-off control grading forTrenches 5, 7, and 10 was prepared following the excavation of adjacenttrenches due to their close proximity. The four corners of each trenchexcavation were surveyed and flagged with wooden lath prior to run-off controlgrading. The run-off control grading areas were flagged approximately 30 feetout from both sides of the long axis of each . trench. At one side of eachtrench, the drums were staged for overpacking. Trench spoils were placed onthe other side. The run-off control preparation consisted of removing alltrees and brush from the vicinity of the trench and grading the run-offcontrol areas so rain water and liquids removed from the trench would draintoward the open excavation. The grading work was performed with a bulldozerfor the first seven trenches and with a trackhoe for the remaining threetrenches. Prior to excavation and drum removal at each trench, sheet plasticwas laid on the run-off control grading to prevent liquids from contacting theunderlying soils.

During trench preparation for Trenches 4, 6, 8, and 9, drums just under thesurface were exposed. Empty drums were removed to the side, otherwise theywere left in place and avoided. For Trench 4, the exposed drums were numberedwith orange paint, and their relative positions were recorded on a trenchlogging form. If any other type of refuse was exposed, it was moved outsidethe boundary of the trench area.

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Air monitoring during trench preparation was performed using a photoionizationdetector (HNu) with a 10.2 electron volt (ev) bulb, The background airreadings ranged between 0.1 and 0.2 parts per million (ppm) during trenchpreparation at all trench areas. When a drum was exposed it resulted inhigher readings, but for less than 5 minutes. See Table 2 for a summary ofair monitoring date collected during trench preparation.

For all trenches, the bulldozer or trackhoe operator was in Level B protec-tion. For Trenches 3 and 4, observers were also in Level B, due to possibledownwind exposure to trench preparation activities. For ',the preparation forthe remaining trenches, observers were in Level C protection, because allpreparation activities were conducted downwind of the- observers and HNureadings were at background levels.

Typical Trench Excavation Procedures

The trenches were excavated using a John Deere 892D-LC trackhoe. The drumswere overpacked using a 720 D backhoe and a 420 D trackhoe. Removal ofsurface soil in shallow lifts (scraping) in the vicinity of the trench wasused to determine the horizontal extent of drums in relation to the trench.

The trench excavations were oriented across magnetic anomalies to provide arepresentative cross-section of the drum distribution within the magneticanomaly. Trenching at each location was initiated in a magnetically cleanarea and extended through the anomaly. When drums were encountered, they wereremoved from the trench with the backhoe bucket and inspected. If the drumswere too crushed to be sampled or were empty, they were discarded on thespoils pile by each trench. Drums with sampleable contents were assigneddrum-specific identification numbers (Trench No. -- Drum No.) and placed onplastic sheeting at the side of the trench. The assigned drum numbers wereused to log the drum locations in the trench prior to removal and identify thedrum on the drum logging form. The drum number was also printed on the drum

—M overpack. This provided a means of tracking each drum from excavation,|f through inspection, logging, overpacking, drum selection, and sampling.

„ The backhoe positioned drums to be overpacked upright on the plastic sheetingIB for drum logging, air monitoring, and photographing. Drum logging consisted^™ of identifying the drum size and type, color, drum condition, and the physical

characteristics of the drum contents. The drums encountered and removed were•rf metal, 55-gallon drums primarily with top and side bungs. One 33-gallon drum•I was encountered and three 5-gallon buckets were overpacked because they

contained material. Most of the drums were devoid of outside markings. The^ drum logging forms are in Appendix A.•

Upon completion of each trench excavation, the trench sidewalis were loggedprior to backfilling. Trench logging included identification of drums visible

^1 in the trench sidewalis, trench width and depth, liquid depth if present, soil^" classification and color using a munsell color chart, and photography of the

trench sidewalis. The trench logging forms are in Appendix B.

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Trenches were not excavated as wide nor as deep as was originally planned.Native soils were encountered within 14 feet of the ground surface at alltrench locations, whereas the depth of drums was limited to 10 feet or less.Consequently, excavations deeper than 14 feet were unwarranted. Water/leachate was encountered between 3 and 10 feet in some trenches which inhi-bited deeper trench excavation.

Each trench was backfilled using a John Deere 892D-LC trackhoe. Disposablepersonal protective^ equipment (PPE) was placed in garbage bags and placed inthe trench prior to', backfilling. Plastic which the excavation spoils wereplaced on was also buried within the trench while backfilling. Aftercompleting the replacement of the trench spoils, the trench was covered withsurrounding fill.

ATR MONITORING

Air monitoring was performed in the work zone during trenching and at indivi-dual drums when they were removed from the trench, inspected, and placed onthe plastic sheeting. Monitoring instruments included photoionizationdetectors (HNu) fitted with 10.2 ev bulbs, MSA 361 hydrogen sulfide (H£S)meter, percent oxygen (0£) meter, methane (CH4) meter, percent Lower ExplosiveLimit (LEL) meter, MSA MX-231 or MSA Micro Card LEL/02 meter, andCompur 4100SD Monitox hydrogen cyanide (HCN) meter. All instrumentation wascleaned and calibrated daily. Calibration logs were also completed daily.All field measurements were logged on an Atmospheric Monitoring Log/FieldSafety (AML/FS) form along with the field observations, drum numbers, photo-graph number, and comments. The highest/lowest readings for each trench aresummarized in Table 3.

SOIL SAMPLE COLLECTION

During excavation, soil samples were collected for chemical analysis tocharacterize nature and the extent of contamination. Soil samples collectedin native soil (based upon visual inspection and instrument readings) werecalled "clean" soil samples. Soil samples collected in stained soil orbeneath drums were designated "dirty" soil samples. Water/leachate sampleswere collected from trenches,'- when present. All sample collection locationsand designations were recorded on the trench logging form.

Soil samples were obtained from the trackhoe bucket, field-screened with anHNu, and placed in a stainless steel bowl. Samples were mixed with a stain-less steel spoon until a homogeneous sample was present. Each sample wasquartered and equal portions were taken from each quadrant to fill the samplejars. After sample collection, 3x5 cards were used as the chain of custodyuntil samples were relinquished to the sample custodian at the field trailer.The information on the card included the sample number, depth of sample,horizontal trench length, HNu reading, time of sample collection, and thesampler's name.

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One drum, 11-14, was overpacked with the following writing on it:

WHITE

GREEN

WHITE WITH ILLEGIBLE GREEN WRITING

Exploratory Test Pits

On April 25, 1990, three additional test pits were excavated north of theabandoned hanger to verify the presence of waste delineated during the elec-tromagnetic survey. The test pit locations are shown on Figure 2.

The test pits were excavated to verify magnetic anomalies detected during thegeophysical survey conducted by Donohue in 1990. The test pits were locatedby the site survey grid and were located at 550N 375E, 550N 500E, and 750N525E.

Drums were not found in the three test pits. The test pit at 550N 375E was25 feet long, 20 feet wide, and 4 feet deep. The soil profile was 10YR3/2silty very fine sand overlaying 10YR4/4 poorly graded fine sand. There wereno metal objects found in the excavation. The excavation was halted at 4 feetbecause native sand was encountered. Photographs were taken of the test pit.

The test pit at 550N 550E was 20 feet long, 10 feet wide, and 7 feet deep.The test pit soil profile was 10YR4/4 silty, very fine sand from 0 to 3 feet.Municipal garbage was encountered at 3 feet and included bedsprings, pipes,wire and metal 1-gallon cans. The municipal garbage was overlying 10YR4/4silty, very fine sand. The excavation was halted after native soil wasencountered. Photographs were also taken of this test pit.

The test pit at 750N 525E was 23 feet long, 20 feet wide, and 8 feet deep.The soil profile was 5 feet of bedsrings, pipes, and wire. The excavation washalted in municipal garbage, because it was clear the garbage created themagnetic anomaly. In addition, drums were not encountered in the garbageexcavated.

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RP/FWASTETM/AB1

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