bofors nobel inc - · pdf filedecision summary for the record of decision site name....

No. 0000004

DECLARATION FOR THE RECORD OF DECISION

SITE NAME AND LOCATION

Bofors-Nobel SiteMuskegon, Michigan

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial action forthe Bofors-Nobel site, in Muskegon, Michigan, chosen in accord-ance with CERCLA, as amended by SARA and, to the extent practic-able, the National Oil and Hazardous Substances PollutionContingency Plan. This decision is based on the administrativerecord file for this site.

The State of Michigan concurs on the selected remedy.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from thissite, if not addressed by implementing the response actionselected in this Record of Decision (ROD) , may present animminent and substantial endangerment to public health, welfare,or the environment.

DESCRIPTION OF THE REMEDY

This operable unit is the first of two operable units for thef • T1

soils in the lagoon area, a major source of contamination at thesite. The second operable unit will involve remediation ofcontaminated soils in the vicinity of the operating manufacturingfacility and remediation of the contaminated groundwater. Theresponse action for this operable unit addresses the principalthreat remaining at the site by treating the most highly contami-nated sludge. Treatment residuals, less-contaminated sludge, andsoils contaminated at low levels will be disposed of in an on-site landfill that will meet the intent of RCRA subtitle crequirements.

The major components of the selected remedy include:

Excavation and treatment, via on-site thermal treatment, ofapproximately 101,000 cubic yards of the most-contaminatedsludge from the lagoon area;

Disposal of approximately 19,000 cubic yards of less-contaminated sludge, approximately 353,000 cubic yards ofcontaminated soils, and solid treatment residuals in anon-site RCRA Subtitle C landfill; and

Upgrading of existing groundwater pumping and treatmentsystem.

STATUTORY DETERMINATIONS

The selected remedy is protective of human health and theenvironment, complies with Federal and State requirements thatare legally applicable or relevant and appropriate to theremedial action, and is cost-effective. This remedy utilizespermanent solutions and alternative treatment technologies to themaximum extent practicable and satisfies the statutory preferencefor remedies that employ treatment that reduces toxicity,mobility, or volume as a principal element. Because this remedywill result in hazardous substances remaining on-site abovehealth-based levels, a review will be conducted within five yearsafter commencement of remedial action to ensure that the remedycontinues to provide adequate protection of human health and theenvironment.

Valdas V. Adamkus L/Regional Administrator

Date

DECISION SUMMARY FOR THE RECORD OF DECISION

SITE NAME. LOCATION. AND DESCRIPTION

The Bofors-Nobel (Bofors) site is located 6 miles east of down-town Muskegon on Evanston Road in Egelston Township, MuskegonCounty, Michigan (see Figure 1). This 85-acre site includes acurrently operating specialty chemical production facility, anunused landfill, a currently operating groundwater pumping andtreatment system, and 10 abandoned sludge lagoons. The southernportion of the site is bounded by Big Black Creek. Pertinentsite features are shown on Figure 2. There are wetlands oneither side of Big Black Creek, within the Big Black Creek flood-plain. The approximate location of wetlands within the siteboundary is shown in this figure. A lacustrine aquifer underliesthe site and is contaminated from previous site activities. Theexisting groundwater pumping and treatment system prevents off-site migration of the contaminated groundwater into Big BlackCreek. This portion of the aquifer is not currently being used.A clay till approximately 150 feet thick underlies this lacus-trine aquifer and separates it from the underlying MarshallSandstone, a drinking water aquifer. There appears to be anupward hydraulic gradient through the till.

Big Black Creek is currently being used for recreational pur-poses. This includes fishing and swimming. In addition, thereis evidence of transient residences on the south side of thecreek.

Approximately 1,800 people live within a 1.25-mile radius of thissite. The primary route of exposure for this population is

nated groundwater will not migrate off-site assuming the existingpumping and treatment system remains operational.

SITE HISTORY AND ENFORCEMENT ACTIVITIES

Lakeway Chemicals began producing industrial chemicals at thesite in 1960. Throughout the 1960s and early 1970s, ten on-sitelagoons were used for disposal of sludge, wastewater, and variouswaste liquids. This practice resulted in contamination of thegroundwater underneath the site and, subsequently, Big BlackCreek. Because of this contamination, the State of Michiganplaced various restrictions on wastewater disposal from the site.In 1976, wastewater from the plant was accepted at the MuskegonCounty Wastewater Treatment Plant, and purge wells were installedat the site to extract contaminated groundwater.

LAKETON ROCARR LAKE

EVANSTON

8IG

Figure 1 Site Location Map

EVANSTON ROAD

LOMAC PLANT

UNUSEDLANDFILL

APPROXIMATEWETLANDROUNOflPV iwVICINITY OFAREA 10

BOFORSSITE BOUNDARY

BIG BLACK CREEK

NUMBERSsSOURCE AREAS

Figure 2 Site Detail Map

Bofors Industries, Inc., merged with Lakeway in 1977 and withNobel Industries in 1981. In 1985, Bofors-Nobel (Bofors) filedfor bankruptcy for reasons including reported environmentalexpenditures in excess of $60 million. As part of the bankruptcysettlement, the State of Michigan received $15 million and theU.S. Environmental Protection Agency (U.S. EPA) received$5 million to be used toward site remediation. As a result oflegal action in bankruptcy court, Bofors was allowed to sell theoperating chemical plant to Lomac, Inc. (Lomac) . As part of thesale, agreements were reached between Lomac, the MichiganDepartment of Natural Resources (MDNR) , and U.S. EPA that Lomacwould not be liable for cleanup of contamination existing priorto the sale of the plant area property. These agreements allowedLomac to operate the plant independently of previous site activi-ties. The site was nominated for the National Priorities List(NPL) and was placed on the NPL in March 1989. The RemedialInvestigation/Feasibility Study (RI/FS) was initiated inAugust 1987.

Bofors Lakeway, Inc., was a wholly-owned subsidiary of BoforsAmerica, Inc. (BAI) . BAI was a wholly-owned subsidiary of NobelIndustries Sweden A.B. (Nobel). Nobel is a Swedish corporation.On May 18, 1990, U.S. EPA sent CERCLA Statute 104 (e) informationrequests to BAI and to Nobel . BAI responded to those CERCLAStatute 104 (e) information requests in part on June 21, 1990.BAI filed a supplemental response on August 27, 1990. U.S. EPAis currently evaluating those responses. U.S. EPA is planning tofund the Remedial Design (RD) immediately.

HIGHLIGHTS OF COMMUNITY PARTICIPATION

The RI/FS and Proposed Plan for the Bofors site were released to

to the public in both the administrative record and an informa-tion repository maintained at the U,S. EPA Docket Room inRegion 5 and at the Hackley Public Library in Muskegon, Michigan.The notice of availability for these two documents was publishedin the Muskegon Press on July 21, 1990. A public comment periodwas held from July 23 through August 23, 1990. In addition, apublic meeting was held on August 1, 1990. At this meeting,representatives from U.S. EPA and MDNR answered questions aboutproblems at the site and the remedial alternatives under consi-deration. A response to the comments received during this periodis included in the Responsiveness Summary, which is part of thisRecord of Decision (ROD) . This decision document presents theselected remedial action for the Bofors site in Muskegon,Michigan, chosen in accordance with CERCLA, as amended by SARAand, to the extent practicable, the National Contingency Plan(NCP) . The decision for this site is based on the administrativerecord.

SCOPE AND ROLE OF OPERABLE UNIT WITH SITE STRATEGY

As with many Superfund sites, the problems at the Bofors site arecomplex. As a result, U.S. EPA organized the work into twooperable units (OUs). These are:

o Lagoon Area Operable Unit (L.O.U.): contamination in thesludges, in the lagoons, in the soils under and around thelagoons, and upgrading of the existing groundwater pumpingand treatment system.

o Groundwater and Plant Area Operable Unit (GW/PA O.U.):contamination of the groundwater under the site and contami-nation in the soils in the plant area.

This ROD concerns the first of these two operable units. Thisoperable unit addresses the principal threat through sourcecontrol. The location of the L.O.U. is shown in Figure 2.

As shown in Figure 2, the L.O.U. includes eight of the 10 lagooncontaminant source areas investigated. The remaining two lagoonsdid not contain detectable levels of contamination. The southernportion of the L.O.U. is bounded by a groundwater extractionsystem that controls the groundwater contaminant plume.

This area of the site poses a principal threat to human healthand the environment because of the risks from contaminant migra-tion from the sludges and soils into the lacustrine aquiferdirectly under site, that is a potential source of drinkingwater. The contaminated groundwater, if it discharges into BigBlack Creek, also poses risk from ingestion of contaminated creekwater. There is also a threat because of the risks from inhala-L.j.uii oi voa.aLj.li2eci contaminants trom tne siudges and soils. 'i'nepurpose of this response is to reduce contaminant migration intothe groundwater, surface water, and air, and prevent directcontact with the contaminants.

SUMMARY OF SITE CHARACTERISTICS

The RI included the following tasks:

o Lagoon sludges and soils characterizationo Plant area soil characterizationo Air sampling and analysiso Surface water and sediment characterizationo Surficial soil characterizationo Aquifer characterizationo Groundwater sampling and analysiso Wetlands surveyo Baseline risk assessmento Treatability studies

The results are summarized as follows.

Contamination and Affected Media

The lagoon area sludges and soils and the groundwater showeddetectable levels of contaminants related to the site. Thesurface water sampling and analysis showed no detected contamina-tion. The air analysis indicated contamination only from theoperating plant. Therefore, only a summary of contamination forthe lagoon area sludges and soils and the groundwater is pre-sented.

Lagoon Area Sludges and Soils

In the lagoon area, 10 potential source areas were identified.In these 10 source areas, the sludge from the lagoons, the soilbeneath the lagoons, and the soil around the lagoons were sampledand analyzed. The organic compounds detected for the lagoonsludges and soils beneath and around the lagoons are presented inTable 1. As discussed previously and as shown in Table 1, detec-table levels of contamination were found in eight of the10 lagoon areas. These source areas were subdivided into fourpossible subareas: lagoon sludge, contaminated soil beneath thelagoon sludge, contaminated soil around the lagoon sludge, and,in some cases, a berm. These source areas and subareas are shownin Figure 2. The source areas were subdivided because the magni-tude of contamination varies considerably among the eight sourceareas and their subareas. From a treatment standpoint, riskswere calculated for each source area and subarea separately toaid in selecting the most cost-effective remedial alternativeswhich provide the greatest protection of human health and theenvironment. Contaminated soils around the laqoons were identi-nea using results from a i-acre grid sampling interval; tnisexplains the irregular source area configurations shown in thefigure. The compounds of concern developed from the baselinerisk assessment are listed below:

o Methylene Chlorideo Benzeneo 3,3'-Dichlorobenzidine (DCB)o Anilineo Azobenzeneo Benzidine

These six compounds of concern were chosen because they arehighly toxic and drive the risk assessment for this site.Methylene chloride, DCB, aniline, and azobenzene are potentialhuman carcinogens. Benzene and benzidine are known humancarcinogens.

The Toxicity Characteristic Leaching Procedure (TCLP) wasperformed on selected lagoon area sludges and soils to evaluatethe potential mobility of metals in the waste material. Theresults of TCLP testing were compared to TCLP standards which canbe used as a measure of metal mobility. The concentrations ofmetals in the waste were found to be below the TCLP standards.Therefore, metals in the sludges and soils are not anticipated tobe compounds of concern at this site.

As discussed previously, these lagoon area sludges and soils area major source of contamination to the groundwater under the siteand, therefore, a source of contamination for Big Black Creek ifthe groundwater pumping and treatment system is turned off. Thelagoon sludges and soils are also a potential source of contami-nation to air in the vicinity of the site.

The volume of each lagoon subarea was estimated using datagenerated during Phase I and II RI activities. The volumes andsurface area associated with each lagoon subarea are shown inTable 2. The volumes for the soils beneath the lagoons includematerial extending from the bottom of the sludge to the averagewater table depth. ' The soil volumes around each lagoon were alsocalculated using a depth of contamination of five feet in eacharea, except in the area between Lagoons 6, 8, and 9. In thatarea, the soil around the lagoons is assumed to be contaminatedto the water table, because of the proximity of the lagoons toeach other and possible overlapping of the lagoon -boundaries.The assumption of contamination only in the top 5 feet for therest of the soil around the lagoons is based on evaluation of thecontaminant transport mechanisms by which the contaminationmigrated to these soils. These soils are estimated to becontaminated by surficial mechanisms such as trackout anduj.iuoj.iie >-^iiT_ai[ixii<j i_ j.uii. iins assumpLjLUJi will need to be verilieuduring the remedial design. The berm volumes were calculated bydirect measurement off the site topographic map and only includematerial above grade. Volumes calculated for soils around thelagoons are based on limited information and should be consideredas approximate values only.

Approximately 454,200 yd3 of total contaminated media isestimated to be at this site. Approximately 22 percent(101,500 yd3) represents contaminated sludge; 34 percent(156,200 yd3) represents contaminated soil beneath the lagoons;39 percent (178,500 yd3) represents contaminated soil around thelagoons; and 4 percent (18,000 yd3) represents contaminated bermsaround the lagoons. The volume of contaminated media may befurther refined prior to remedial design.

Unlit: ppb TABLE 1SUMMARY OF MA> lUM LAGOON SLUDGE AND SOU. COMPOUNDS AND CHEMICALS

ORGANIC COMPOUNDS

U*lhv<«n* ChtorkMT •irachtof oair>vl«n*Action*B«ni*n«2-Buunon*Elttvlb«ni*n*Tolu*n*XvteiM to.ni.pl2-ChlofoanKm*3.3'-DkMoiob«nildkM1 .2.4-ItteMotob*nran«&i 13 -chtoroeh*nvl)-diM*n*- 1 -euld*3.3'-OicMorab*nitdlrM bonwrip-CMoiophanyl] (4<Moroph«oyf)-m*itt*non*Anflm*Aiob*nnn«Bcnridin*Alxvl B*nzBn* bomcraAro>vb*ni*rMSuffixl.t'-SuffooyMtp-inMhYlf-BMtMrM

LAGOONI

SL

00

00

0518900120260000100000

083000300000

0

000000

SB

00TO00017030230000036005500

660

830003)00

0

SA

NANANANANANANANANA27000NANA

NA

NA

NA

NA0NANANANA

e0

0000264f 5

GO1> XOS.C )0

03? Ot&> SO

0

000000

•#:*y *. ^p^ 3g$

MttnvtMM CNortd*Tut «e hKMoMnvtan*ACMOIMB*AI«M

2-BuUnacMElhytlMAr*n«Totutn*Xyf*n« IO.rn.Dl2-ChtorcMnWn*3.3'-Dtcnioroto«futd)rM1 .2.4-Tnchlorob«nr*n«Bi» (2-chhMOohanvn -dl*z* n*- 1 -oi6d«3.y-OcWo»oto»orkHo« Itomcrt3-chloi cpfwnyi} (4 •chJoroptMnyl)•m*ih«fKX»Anmn*AjOtwnjenB

•niidin*AlKyl B«nJ«n* Itonwra

Ajoxvb«nl*n*Sultui1 . r-Sullony1bl*{2-methvn-B*nl*n»

LAGOON T

SL

ia0

000000020OOOO0

03000100000520000

0

220000

0

00

0

SB

00o000000toooo0051008400

0

0

0

0

0

03000

SA

00200010024013000000084000

0

13000

00

0

a0o000000o-00000

0

0

0

0

00

0

LAGOON 3

SL

0

0

09800000011000000220000S300000

15000000?600006100000

O

1200000034000000B90OOO0

0

SB0001300000

2700001100000390340000B30001900000

07001000000SfiOOOO14800046000000

SA

NANANANANANANANA39002700000049000002900000

S9009000410

46800017000000

a00000000000000

0

0000o0

lAOOON*

su1200600026000000000012000160000071000170000026000

17003300013OOO147000

00

0

SB

000000001200080000710007300018000

0

43000

147000

000

SA

0

o0000001MO88000007700034000

35034000tOTOOO

00

0

B

GOO340

01.4000o40.0000

6000750.0003.5500050.00013.000

650

Ifl.MO6.50073,500

000

LAGOONS

SL

4

0023001714

09300000

73000990000330000

017000000000

SB4

0

00003003300000

320002900

0590021000000

SA

NA

NA

NANANANANANA540150000tso9600011000

0300000000

B

00000000000000

0000000

LAGOON 6

SL

00910902501200023000001100000003000023000000

•390OOOO0200000•13000000

00

0

SB

00O

00010000038000700000000

D8007400059000

O

00

SA

00O

12000000(600000038000010000029000049000I90O6200000

078013001460000CJ03600015000

B

00000000000o00

0000

000

LAGOON e

SL

22000

0009200130000500002200021000073000010000001300000

068OOOO70000123000000

SB

0000000120021000390000061000204000280000

O

2200078006640000O

SA

NANANANANANANANA9401500001909600011000

0360000000

B

1.10000004.00069.00029.00011.00010.900036S.OOO900.000690,000

0540.00039.00061.900000

LAGOON 10

SL

000a0090240002900000003900000190000

MTOO230000•13000O

05000082OOO

88

00It000210043007100001132008300

34005000022004400

1000000

SA

000000000380000001 TOOOO06000

390340000

O00

B

000400a012.0001.450.000001.790.00085.000

830115.0006.5000

42.900041000

SL: Sludg*.SB; Sott b*n*Mh Ugoont.SA: Soil around lagooniB; Baimi•: D«i» oblilnad ttotn compoiH* Mmpl* of Lagooni B »nd to t lodge

/ /

Groundwater

Monitoring and purge wells were sampled and analyzed during theRI. The organic compounds detected in the groundwater arepresented in Table 3. The extent of contamination in the ground-water appears to be bounded by the plant area to the north andthe groundwater pumping and treatment system to the south.Contaminated groundwater at the site appears to be captured bythe groundwater pumping and treatment system. At the presenttime, approximately 1 million gallons of groundwater per day iscollected by the existing groundwater pumping and treatmentsystem and is pumped to a biological/carbon (PACT) treatmentsystem owned by Lomac that also treats Lomac wastewater. Thetreatment effluent is discharged to the Muskegon CountyWastewater Treatment Plant.

Based on historical data and groundwater modeling, if thegroundwater pumping and treatment system is turned off, thecontaminated groundwater will discharge into Big Black Creek, andthe creek will become contaminated.

Potential Routes of- Migration

Potential routes of migration and contaminant fate and transportwere evaluated for the Bofors site. Based on this evaluation,the most significant pathways for release of contaminants at theBofors site are through the air, surface water, and groundwaterpathways. The Phase I baseline risk assessment indicated thatthe risks associated with ingestion of the sludge and soils wassignificantly less than the risks associated with the ground-water, surface water, and air pathways. Fate and transportmechanisms are summarized below for each of these three£. —— __*... ~ J __ .

\_ Air Pathway

Contaminants can be released to the air in two ways, either byparticulate or volatile emissions. Risks from particulateemissions were estimated for exposure by inhalation. These riskswere estimated as approximately 100 times less than the risksfrom inhalation of volatile emissions. Therefore, volatilizationappears to be the primary release mechanism to the air pathwayfrom the lagoon area sludge and surficial soils surrounding thelagoons. Benzene, methylene chloride, and azobenzene are classi-fied as highly volatile compounds and may readily volatilize fromthe sludge and contaminated surface soils. Aniline may alsovolatilize from the sludges, but to a lesser extent, and DCB andbenzidine may volatilize to a limited extent. Even though thesemoderate and low volatility compounds may volatilize to a lesserdegree, there may be significant mass loading to the atmospherebecause of the large surface area and high concentrations ofthese compounds in the lagoons. Modeling of emission rates andcontaminant transport via the air pathway have shown that thelagoon areas, due to their considerable surface area, present a

TABLE 2

SOURCE AREA VOLUMES (yd3)BOFORS SITE

Muskegon, Michigan

SourceArea

1

3

5

6

7

8

9

10

Total

Percentof Tot-alVolume

Sludge

3,400

7,600

8,000

3,400

7,000

28,400

9,600

34,100

101,500

22.3

Berms

300

0

0

2,300

0

5,500

0

9,900

18,000

4.0

SoilBeneathLagoons

9,300

10,700

14,400

5,400

26,400

28,400

30,500

31,100

156,200

34.4

SoilAroundLagoons

7,700

3,900

6,300

17,900

12,600

14,400

33,100

82,600

178,500

3 9. *3

TotalVolume

20,700

22,200

28,700

29,000

46,000

76, 700

73,200

157,700

454,200

Percentof TotalVolume

4.6

4.9

6.3

6.4

10.1

16.9

16.1

34.7

Note: Soil volume around the lagoons was calculated assuming only the top5 feet of soil is contaminated.

RP/BFRSRQD/AA3

Pig* 1ol3

InlU: mg/kg [pcwn)

Background SocKgiound FlatdMWioi* M*44 Blank*

HAXMMMVOW

C*rtxxi Otiolflda -

Chlofobaniana -

1.2-Otchlotatruna -1.2-OlcMoMMViyiwM -MalnyMna Chkxkf* - - NO-3J•IracnloroMhytofM -

ricMoroMhyton* -

Vinyl Chtorida -

Nonnaloq«nal*d Compound*

Acalon* - - -

B*ni«f* - - NO-5

TokMn* NO-3J - NO-4J

•yf*n*i NO-t - NO-71,3.3-TfttnairiylcycIohaiianonc** - - -

Unknown* - - NO-2SJ

MW84* MWttl* UW102-

H*loaan*f*d VotaiUa*

Cwtaon OHuMd* -CMeratMntwM -

^^^^L. ~ I IM*thyl*n« Chlortd* - - NO-9ta/acnlOfO*Utyt*n« - - NO-2U

TrfchkxoMhytam -

Vinyl Chtenda -

tonh«kx]«n*l*d Compound*

AcMon* - - NO-«2

Banian* 3J-0 - NO-730

TokMna NO-4

Xyton* NO-3J

Unknown* - &J-30J

LEGEND:

^ TAflLE 3SUM \FTV OF DETECTED GROLWQWATER COMPOUNDS

BotoraSKaMullcvgon. Michigan

JunWJuty 19&9VOLATILE OFGANC COMPOUNDS

WC1' WC: WC27- LW1 LW3 LW4 PW31

- - 1000 -

920_

NO-19 J - - 1900NO- I4i ; - - 12OO - ZJ

5IOJ 18000. . . . - . .

—

44000J-fl> »E - - 3100

ND-3J - 37000-09000 4000 --

NO-4J 31000J-I1 COE 2QOOOO-2aOOOO 23000 a 70 14000 2J

NO-4J - - -- - -

NO-&J 44J - MOQJ 33J

MW103* MW10- MW109* UW100" MW108* MW11O*

-

- - - NO-U

NO-3J - NO-3J - - NO-3J

_ - -

ND-4J

-

NO-4000E NO-310 NO-Ct

' NO-200NO-4J NO-4J NO-4J

NO-12 NO-15J ND-13J ND-8J NO-5J

PW33 PW39 PW41 MW07 UW18 UW41 MWSO* MW31' MW32-

2 4 0 - - - - - - - -

1 1 0 - 5 5 - - - - - -

2 9 0 - 1 8 0 - - - - -

fl 11006 31J

_ - 2 2 0 - - - - - -

- - 4 3 - - - - - -

1000 - 5 2 - - - - - -

31J - NO-7J NO-fiJ

- 1 2 0 - M - - -

1100 - - 28006 MO - NO-H

S 100 - - ND-U NO-12280J - 85J - -

- - 2 7 5 8 J - 5J - - - NO-10J

-. NO: Nol daiactad. NO uMd wti*n [«nga* Of concantiailoni wai* found.

E. E*c*ad* c«ntn»llon tanga.

•: W«llc!uitai.": T«di»ih««ly Idanilliod compound.

ScrfC

1

a-Chkxoa-JMn*

4-CMoraanJUn*

1 •OKMotoMnian*

3.T-Olcn-xoe*nrMi-*

1 ,2.4-TrtchkM ob-ruMM

3.7-Olchlofob-ruMlM ltom-r»

3 J-OMtorabarufcftw bom*, (conf'd) »

J-O-xoph«iy<) oi (4-Chlotoph«nyl)U*in«

'rtcMoto-t-pK)p«n> Itomw

Aw**-*.

AMftaphthyl**

AnMn*

Arthr.e-n.

AMto-n~MM

BMUktln*

BMXoWArthf-C-n*

BMnMPyo*

BMuyi Alcohol

hi p-£my»»*y1) Phlnaiai •

CruyMM

DtbMualurftn

DlmMhyl Phih-lau

Dt-n-Butylphina 1 •!•:tauianlfwn*:tMn*o*

liophoroni

2-M«thy)n«phl hal* n«

2-M«iny1phinol

4-M«inylpt>«no<

Naphthatan*

NNiob«ru*n«

TABLE 3SUM- *RY OF DETECTED GROUNDWATER COMPOUNDS

Bolon SH«. Mutlwaon. MichiganJune/July. IBM

S£MIVOLATIL£ ORGANIC COMPOUNDS

FkldBlank* WCl* WC2* W '?• LW1 LW3 LW4 FW31

NO-25 ND-4J ND-14J B40C 3000 7200 130 170J 13J

-

- 400

ND-10J - B3a <800 440 22J

- - - NCWJ 5 8 J - _ _

ND-T2J - 74OJ 19OJ UOJ 24J

_

fXm" - - - NDOOJ - _ _ _

- 20- - - - 21

- BSO&iOOOO 1SOO -

- - (4J

- - 18J

NO-'iOJ - - - M

- 1BJ

- - - 230

5J

ND-U - - " - -

IQJ

18J

ND-4J - 72J 4J I20J

-

Iflj

Iflj

M-170 - 450 1400

- . - NO-480 12J

13J-470 NO 'J S3J 17J

NO-170 5J

2CU-650 22

ND (, -TO 450 -

PW33 PW36 PW41 MVftM* MW05* MW7

1300 W 3900 4J

- - - - -

- - - - -

BOJ 100 400 3J

- - - - - -

S«QJ eaoj aaooj -aoj IBOJ -

_ _

_ _04J

- _ _

SOJ

- 240 230 -

_ _ _ _ _

_ _

_

ND-1M 1JB-2JB 4000J

- - - - -

- - _

-

_

_

_

53J - 290 -

8J

- - - - -

-

- - 13J

- - - - - - -

3 o<3

InHt: tngfltg (ppri)

1 - NKr (no- O -n-P iDpyl amln*

.I'-OlpMnyt 2,2-Ot-/-ln*"

•U*i hyt-3- p*nl*n -1 -on*

-MyOioxy •* - m«myi • 2 - p*fii«rxxi«'

rtmp J*ofn*((i) (cooTOJ**

1,2.4-TfHhlo-WM"

1,3.3-Trtlhtan*">l*th«Myb*ni*nMmln« town**"

WCI'

TABLE 3SUW ^RY OF DFnCTEDGPOUNOWATER COMPOUNDS

Baton Sll«, Mutkagon. MichiganJun*/July, ifioa

SEMIVOLATILE OFCANC COMPOUNDS

WC2- LW4 PW31 PW33 PW39 PW<1 «W(M*

NO-170J

ND-18OJ

34OJ 40QJ

NO-42J

NC-t40J

NO-49CU

NO-ISOJ

NO-120J

4XJ

100J

340J

B7QJ MDQJ

NO-; oat190. lOOJ

NO -AXJ

NO CU

300J

1-CQj

21000J

NO-12J

NO-1Q1QJ 830J2292OJ

itoocuSSOJ

2COOJ

780J

278101 XttOO 2B5QJ- 1 0O500J 04_J S13OJ

32000J

300J

I4COJ

aiQjM

J-OJ

MOJ

4 _ t B

Unit): mg/kg (ppdi)

MW7

HrtM.n.1*. S«f-M>U1U.»

frChteMfl-ta. *J

4-ChkMo-nHln*

l^^^L1.2.4-TitcMo.ob.ru.n.

i,j vKnlofOvAflrtOnfl liofTttF^ —

>O-eraph*nyQ o» (4-Ch_xoph*nyQMalh_narM**

flchtoro-t-p«Op*n* toomM

Nont«JoQ«nM*d SMnfcoiUltat

AnBtn*

Erl~~ :BwuylAicohol

Bto{2.£m¥!h,-y1)PWh_l.l. 4000J

CricyMn*

Olb«ntatijr«n

Oim.thyiPNh_W.t£Z£r"tiophoron*

2-M.lhytft_phlh_t.n. BJ

2-hUlhylphcnol

NZTTT iLNnroO«rU«n«

N- NHraio- Ol - n-Piopyl*mtn«

TABLE 3SUM RY OF DETECTED GHOUNDWATER COMPOUNDS

Baton Sn«. Mutugon. Mlefiig-nJurM/Juty, 1BBA

SEMIVOLATILE ORGAMC COMFOUNDS

MWt4 MW41 M.1* MW»4* UWgi* UWIO^ UW10-* MW104* MWtOfl* MWtOfl* WW106' UW110

750 - - I-CU-IXJOOJ IJ-tOO - - 410-1000 M-taOO 12-«200

_j - - NO-42J - NO-83 ND-14J

- - ND-200 - NO-MO 2S-140 12J-200

_ - _ NO-UU _ _ _

- - - - NO42OJ 21J - - NC-MQJ NO-SOOJ NO-1000J

_ - _ NO-25J _ _ _ _ _ _

- - - _ _ _ _ ND-2-J NO^OJ _

- - - _ _ _ _ _ _ NO-78 NO-23

- - - - - 140-240J NO*J - - MJ-MO 100-1X0 71400

- - - ~ — — _ _ _ _ _ -

- >2J NO-2J NO-.J NO-1QJ - 1J8-2JB - NO-ftJB NO-3J

- - - - - - - -

- - - - - - - -

2 J B - - - _ _ _ _ _ _ _ _

- v _ j _ _ - _ . . ND-UB -

- ~ - _ - _ _ ^ _ _ NO-3J

_

- - - - - - - - -

- - _ _ _ _ . . _ _ _ _

2 J - - _ _ _ _ _ _ _ _

NtWU - - - - - -

UnNi: mg/kg (ppm|

Ph«nol

Py»»n«

,1'-Dlph«nyl 2.2 -OUmtn*

4 -M*ihyt- J- p«m>n -J -on*

'rtmp l*ofn«((() (confd)**

cMlc Actd

MW14 MW«I

TABLf 3ARY OF DETECTED GHOUNDWATER COMPOUNDS

Boton SN«, MiriMgon, MichiganJim/July. 19M

SEMFVOLATLE ORGANIC COMPOUNDS

WWS4- WW91' UWI02* MW1Q3* MW10S* MW106' MWtOfl* MW110

NO-140

aij-32ooj

MO-31J

NO-lflJ

NO-34QJ

NO-44J

ND-30J 30QJ-8790J 1&J-344J 13AJ-21BJ NO-1100J NO-23J NO30J

l£QENO:

8 : D*t«ci»d <n lab and/or fl«ld blank.

-, NO: Not d«t*ct*d. NO u»*d <mh*n rangn ol cooc«nr™tton« "•(• found.

J : Vdu* (•pon*d c*p(*M(il* an ntknal* a* valu* It abov* lnim<rn*nl dai*ctlon llmN but b*to* onl/act r»qul(

W*l dull*!.

TiMaihMly ld*ntHI*d compound.

Nol«: No ivmNolftlllai «*•(• lound tn th* background umpl*.

significant source of volatile contaminant transfer to the air.Even though air analysis indicated contamination only from theoperating plant, sampling and analysis of this medium containsuncertainties.

Photolysis, or the breakdown of compounds through exposure tolight, may also be a loss mechanism for benzidine, azobenzene,and DCB in the sludge and surficial soils. This mechanism may bepartially responsible for the general absence of benzidine in thesurficial soils. However, the breakdown products from photolysisof these compounds are hazardous. Oxidation may be a lossmechanism for benzene, benzidine, and aniline, especially in thelagoons with high iron content such as Lagoons 3 and 9.

Groundwater Pathway

Another contaminant migration route is through the groundwaterpathway. Contaminant release to the groundwater has occurredfrom the lagoon sludge, soils beneath the lagoons, and contami-nated soils around the lagoons due to infiltration of waterthrough these media into the groundwater.

Sorption significantly decreases the mobility of azobenzene andDCB, especially in the sludge, because these compounds stronglysorb to organic material. This may be the reason these chemicalsare currently present in such large concentrations in the lagoonsludges. Methylene chloride and benzene sorb to the sludge butless strongly. Benzidine and aniline do not appear to stronglysorb to lagoon sludges. Sorption has a lesser effect in soilsbeneath the sludge due to the 1 <-".. r>rganir content of these soils.However, even if soils have low organic content, sorption may besignificant for DCB and azobenzene because of the hiqh affinityor tnese compounds to even small amounts or soil organicmaterial.

Dissolution and leaching of compounds from the sludge and soilappear to be the primary transport mechanism to the groundwaterin the upper lacustrine aquifer. The contaminated groundwater inthis aquifer does not appear to be a potential source of contami-nants to the Marshall Sandstone drinking water aquifer due to theupward hydraulic gradient through the clay till that underliesthe upper lacustrine aquifer. Furthermore, diffusion of contami-nants through the till is expected to be extremely slow.

Surface Water Pathway

During the RI, no surface water runoff was observed. The primaryroute of contaminant release to the surface water appears to begroundwater discharge. As noted previously, contaminated ground-water is not presently being released to Big Black Creek since itis being intercepted by the groundwater pumping and treatmentsystem. Therefore, groundwater discharge is not considered a

ReceptOf ; r = 402.34mAzimuth = 0

Compound

SLUDGE ONLY

Methylene ChlorideJenzene3,3'-DichlorobenzldlneAnilineAzobenzeneJenzidineTotal

SOIL BENEATH LAGOONS

dethylane ChlorideJanzene3.3'-DichlorobenzldlneAnilineAzobenzeneJanzidtneTotalBERMSeihylene Chloride

Benzene3,3'-Dichlorobenzldlne

AzobenzeneBenzidineTotalSOIL AROUND LAGOONS

Meihylene ChlorideBenzene3.3'-DichlorobenzldineAnilineAzobenzeneBenzidineTotal

TABLE 4ANNUAL AIR CONCENTRATION

(ug/m3)Bofors Site

Muskegon, Michigan(Azimuth = 0)

Lagoon I

NDND2-6E-05NONONO __2.6E-05

NONONO4.TE-022.1E-03NO4.3E-02

NONO7.9E-06NONONO7.9E-06

NDND1.0E-04NDNONOl.OE-04

NO: Contaminant not detected in sample(s)NP- Media not present in

Lagoon 3

ND1.1E + 004.9E-05ND6.0E + 002.4E-037.1E+00

ND1.8E-023.6E-052.2E-Ot2.56 + 001.4E-032.7E + 00

NPNPNPNPNPNPNP

NDND2.7E-051.4E-022.9E-Ot1.2E-043. IE-01

from ihat lagoon.

Laqoon 5

3 £-033 E-033 £-05N5 E-01N )5 .£-01

6 E-03N >2- £-05N -1. E-014 e-04i e-oi

NNNNN'NiN

N:N:5 E-05Nll.fH-01Nf1. -£-01

Laqoon 6

3.7E-02ND1.0E-05NO4.BE-014.9E-045.1 E-01

NDNO1.4E-05ND1.3E-013.9E-041.3E-01

7.1E-02ND1.3E-05NO8. IE-015.SE-048.8E-01

NDNO8.4E-05ND2.6E-01NO2.6E-01

Lagoon 7

1.2E-02ND4.4E-05NO2.4E-01ND2.5E-01

NDND3. IE-06NDNDND3. IE-06

NPNPNPNPNPNPNP

NDND8.5E-05ND1.4E-02NO1.4E-02

Laqoon 8

1.3E-018.0E-026.6E-056.6E-024.8E-011.2E-037.6E-01

NDNO3.0E-05ND1.7E-01NO1.7E-01

t.2E-011.0E-016.2E-051.8E-012.6E-01NO7.2E-01

NOND2.1E-058. 4 E-034.5E-02ND5.3E-02

Laqoon 9

ND8.4E-021.6E-047.7E+001.3E+015.2E-032.lE-f01

NDNO2.9E-052.5E-018. IE-017.4E-041.1E+00

NPNPNPNPNPNPNP

NO1.1E + 016. IE-05ND6.9E-026.1 £-041.1E + 01

Laqoon 10

ND3.1 E-035.0E-055.0E-028.6E-018.2E-049.2E-01

NO5.5E-032.4E-051.1E-017.4E-016.2E-048. 6 E-01

ND2.4E-032.6E-051.7E-026.4E-01NO6.6E-01

NDND2.8E-049.0E-027.1E-01NO8.0E-01

specified lagoon area.

potential route for migration as long as the groundwater pumpingand treatment system is in operation. However, past site condi-tions and computer modeling performed for the baseline riskassessment have shown that, if the groundwater pumping and treat-ment system is turned off, groundwater will be a major contamina-tion migration route to the surface water.

Potential Receptors

Populations that could be affected, if exposed, include:

o Industrial workers (Lomac, Sun Chemical, Eagle, commercialfacilities north of Evanston Road).

o Residents on VJoli Lake, Laketon, o.trr, Evanston, Mill Imn,Summit, and Ravenna Roads within 1-1/4 miles of the site,

o Residents of the trailer park to the northwest of the site,o Transient residents on the southern side of Big Black Creek,o Residents using groundwater or surface water at the site at a

future date.

Environmental areas that could be affected, if exposed, areprimarily Big Black Creek, the wetlands around Big Black Creek inthe immediate vicinity of the site, down-stream surface waterbodies, and wildlife associated with these areas.

SUMMARY OF SITE RISKS

Human Health Risks

Contaminant Identification

The media of concern in this onerahl e unit are the contain inat-.edsludges and terms in the disposal lagoons 'and the contaminatedsoils around and under the sludge lagoons. As discussedpreviously, six contaminants of concern were identified in thebaseline risk assessment from a list of 27 organic compoundsdetected in the RI. These compounds are:

o Anilineo Azobenzeneo Benzeneo Benzidineo 3,3'-Dichlorobenzidine (DCB)o Methylene Chloride

The concentrations of these compounds of concern that were usedfor the risk assessment are presented in Tables 4 (air),5 (groundwater), and 6 (surface water). The maximum concentra-tions were used during the risk assessment to develop risks forthis operable unit.

Jnits: ppm

Compound

SOIL AND SLUDGE

Methylene ChlorideBenzene3,3'-DichtorobenzidineAnilineAzobenzena3enzrdine

SLUDGE ONLY

Melhylene Chloridebenzene3.3'-OichlorobenzidinsAnilineAzobenzene3enzidineSOIL BENEATH LAGOONS

Methylene ChlorideBenzene3,3'>Dichlorobenzid!n0AnilineAzobenzeneBenzidlne

BERMSMetnytene ChlorideBenzene3,3'*0ichlorobenzldlneAnilineAzobenzeneBenzldlneSOIL AROUND LAGOONS

Methylene ChlorideBenzene3,3'-DichlorobenzId!neAnilineAzobenzeneBenzidine

NP = Berms not present In

Laqoon 1

O.OE+00O.OE+005.8E-042-5E-038.5E-040-OE + 00

O.OE + 00O-OE + OO5-8E-04O.OE+00O.OE+00O.OE+00

0-OE-fOOO.OE+00O.OE+002.5E-038.5E-04O.OE + 00

O.OE + 00O.OE + 004.3E-05O.OE+00O.OE +00O.OE + 00

O.OE +00O.OE+00L4E-02o.oe+ooO.OE + 00O.OE + 00

these source areas

TABLESGROUNDWATER CONCENTRATIONS OBTAINED FROM .THE AT123D MODEL (PPM)

Bofors SiteMuskegon, Michigan

Laqoon 3 1 qoon 5 Laqoon 6 Laqoon 7 Laqoon 3

O.OE + 006.2E-019.3E-03O.OE + 007.5E-041.0E + 00

O.OE+002.6E-011.2E-03O.OE + 001.2E-046.7E-02

O.OE+008.8E-051.3E-025.7E-027.56-041.2E-01

NPNPNP .NPNPNP

O.OE + 00O.OE + 001.4E-022.5E-046.9E-04L8E-04

3.7E 53.4E 5LIE- 2O.OE • 008.5E-04LIE. 3

1.5E-63.4E-066.7E-04O.OE * 001.2E-04O.OE + 00

2.2E^ 3O.OE 4 007.7E-f 3O.OE -• 008.5E-( t6.8E-C4

NPNPNPNPNPNP

O.OE 4 00O.OE+008.4E-03O.OE + 006.9E-04O.OE + 00

2.3E-04O.OE + 002.2E-03O.OE + 001.8E-041.5E-04

2.3E-04O.OE+002.8E-04O.OE+003. IE-056. IE-03

O.OE+00O.OE + 003. IE-03O.OE + 002.5E-041.2E-03

3.0EXJ2O.OE+004.5E-04O.OE+006.9E-051.8E-04

O.OE+00O.OE+001.5E-02O.OE + 001.2E-03O.OE+00

5.1E-06O.OE + 008.3E-03O.OE + 003.8E-04O.OE + 00

5.1E-06O.OE + 00L7E-03O.OE + 003.8E-04O.OE + 00

O.OE + 00o.oe+008.3E-03O.OE+00O.OE+00O.OE+00

NPNPNPNPNPNP

O.OE + 00O.OE + 002.4 £-02O.OE+00LSe-04O.OE + 00

1.9E-034.0E-032.6E-02O.OE + 002.2E-03O.OE + 00

1.9E-034.0E-033.4E-032.3E-033.8E-042. IE-02

O.OE+00O.OE + 003.6E-02O.OE + 002.9E-03O.OE + 00

7.8E-055.4E-042.9E-03L6E-042.8E-041.3E-03

O.OE+00O.OE + 008.6E-042.2E-038.5E-04O.OE + 00

Laqoon 9

O.OE+004.5E-04LOE+002.1E + 001.6E-031.3E-01

O.OE + 004.5E-042.4E-032.1E+002.3E-041.3E-Ot

O.OE+00O.OE+006.7E-021.3E-022. IE-037.2E-03

NPNPNPNPNPNP

O.OE+004.2E-013-6E-02O.OE+X9.7E-042.0E-03

Laqoon 10

O.OE+003.4E-063.5E-021.3E-022.9E-033.9E-02

O.OE + 002.0E-054.7E-034.2E-035.3E-044.1E-02

O.OE+002.3E-054.8E-025.7E-034.1E-033.6E-03

O.OE+002.1E-055.1E-034.6E-045.0E-043.94E-03

O.OE+00O.OE + 001.8E-017.9E-041.3E-02O.OE + 00

f:-

Jnits. ppmCompound

SOIL AND SLUDGE

Methylene ChlorideBenzene

3,3'-Dich1oK>benzidineAnilineAzobenzenelenzidine

SLUDGE ONLY

•Aethylene ChlorideJanzene3,3'-DichlorobenzidineAnilineAzobenzeneBenzidineSOIL BENEATH LAGOONS

Methylene ChlorideBenzene3.3'-DichlofobenzfdlneAnilineAzobenzeneBenzldineBERMS

Methylene ChlorideBenzene3.3'-Dichlorobenz!dineAnilineAzobenzeneBenzidineSOIL AROUND LAGOONS

Methylene ChlorideBenzene3.3'-Dichlorobenz idineAnilineAzobenzeneBenzidine

TABLE 6SURFACE WATER CONC NTRATiONS OBTAINED FROM THE AT123D MODEL (PPM)


Lagoon 1 Laqoon 3 t poon 5 Laqoon 6 Lagoon 7 Laqoon 8

O.OE + 00O.OE + 005.8EO62.5E-OS8.5E-06O.OE + 00

O.OE + 00O.OE + 005.8E-06O.OE + 00O.OE + 00O.OE + 00

O.OE + 00O.OE + 00O.OE + 002.5E-058.5E-06O.OE + 00

O.OE + 00O.OE+004.3E-OrO.OE + 00O.OE + 00O.OE + 00

O.OE + 00O.OE + 001.4E-04O.OE+00O.OE + 00O.OE + 00

O.OE + 006.2E-039.3E-05O.OE + 007.5E-061.0E-02

O.OE+002.6E-031.2E-05O.OE + 001.2E-066.7E-04

O.OE + 008.8E-071.3E-045.7E-047.5E-061.2E-03

NPNPNPNPNPNP

O.OE + 00O.OE + 001.4E-042.5E-066.9E-061.8E-O6

3.7E-< 134E-< !ME-i :O.OE • 308-56-Gu1. IE-05

1. 56-083.4E-036.7E-OCO.OE -t 001.2E-0-3O.OE-t :»

2.2E-01O.OE-* TO7.7E-0 .O.OE-t »8.5E-C6.8E-( •

NPNP "NPNPNPNP

O.OE-t 0O.OE-t 08.4E<O.OE 4 06.9E-CO.OE-t 0

2.3E-06O.OE + 002.2E-05O-OE + OO1.8E-061.6E-04

2-3E-06O.OE + 002.8E-06O-OE + OO3.1E-076.1E-05

O.OE + 00O.OE + 003.1E-05O.OE+002.5E-061.2E-05

3.0E-04O.OE + 004.5E-06O.OE+006.9E-071,8E-04

O.OE + 00O.OE + 001.5E-04O.OE + 001.2E-05O.OE + 00

5.1E-08O.OE + 008.3E-05O.OE + 003.8E-06O.OE+00

5.1E-08O.OE+001.7E-05O.OE + 003.8E-06O.OE + 00

O.OE+00O.OE + 008.3E-05O.OE+00O.OE+00O.OE + 00

NPNPNPNPNPNP

O.OE + 00O.OE + 002. IE-04O.OE + 001.5E-06O.OE + 00

1.9E-054.0E-052.6E-04O.OE + 002.2E-05O.OE + 00

1.9E-054.0E-053.4E-052.3E-053.8E-062. IE-04

O.OE + 00O.OE + 003.6E-04O.OE + 002.9E-05O.OE + 00

7.8E-075-4E-062^E-051.6E-062.8EO61.3E-03

O.OE + 00O.OE + 008.6E-062.2E-058.5E-06O.OE + 00

Leqoc 9

O.OE + 004.5E-061.0E-022.1E-021.6E-05OE-03

O.OE + 004.5E-062.4E-052. IE-022.BE-061.3E-03

O.OE + 00O.OE + 006.7E-041.3E-042.1 E-057.2E-05

NPNPNPNPNPNP

O.OE + 004.2E-033.eE-04O.OE + 009.7E-062.0E-05

Lagoon 10

O.OE+003.4E-083.5E-041.3E-042.9E-053.9E-04

O.OE + 002.0E-074.7E-054.2E-055.3E-064.1E-04

O.OE + 002.3E )74.8E-O45.7E-054. IE-053.6E-05

O.OE + 002.1E-075.1 E-054.6E-065.0E-063.94E-03

O.OE + 00O.OE + 001.8E-037.9E-061.3E-04O.OE + 00

NP = Berms not present In these source areas.

The main health effects of these six compounds are as follows:

o Aniline: Attacks the blood, liver, kidneys, and cardiovascu-lar system. May cause anoxemia, central nervous systemdepression, or cyanosis. Headaches, irritability, dyspnea,unconsciousness, and even death may result from cyanosis.Aniline is considered a potential human carcinogen.

o Azobenzene: Can irritate the eyes, skin, and respiratorytract. Azobenzene may also cause blood disorders. Azoben-zene is considered a potential human carcinogen.

o Benzene: Acute exposures produce primarily central nervoussystem effects such as dizziness, nausea, headaches, loss ofbalance, narcosis, coma, and death. Benzene is also a knownhuman carcinogen and causes several forms of leukemia.

o Benzidine: Direct contact may cause contact dermatitis andprimary irritation or sensitization. Benzidine is also aknown urinary tract carcinogen with an average latency periodof 16 years.

o 3.3'-Dichlorobenzidine (DCS): Direct contact may causeallergic skin reactions. DCB may contribute to bladdercancer and is considered a potential carcinogen.

o Methvlene Chloride; Repeated contact may cause dermatitisand eye and upper respiratory irritation. Methylene chlorideis also a mild narcotic; effects include: headache, giddi-ness, stupor, irritability, and numbness. Exposure may causeelevated carboxyhemoglobin levels. Methylene chloride isconsidered a potential human carcinoqen.

Exposure Assessment

Based on the baseline risk assessment, several exposure pathwayswere evaluated, including:

o air, as a result of volatilization of organic compounds fromthe surface of the lagoons;

o wetland sediments through resolubilization of contaminantsand transport downstream in Big Black Creek;

o groundwater through direct use of the groundwater,o surface water, through potential contamination of Big Black

Creek by contaminated groundwater;o direct contact with waste, ando ingestion of waste.

Three of these pathways presented the most significant risks topotentially exposed populations:

o ingestion of contaminated groundwater from infiltration ofcontaminated precipitation from the lagoon area;

o ingestion of contaminated surface water;o inhalation of contaminated air from volatilization of organic

compounds from the lagoon area surface.

Potentially exposed populations used in the baseline risk assess-ment included adults living on- and off-site. Groundwater, air,and unsaturated-zone transport modeling was performed for thecompounds of concern to characterize exposure point concentra-tions. Modeling procedures were developed to evaluate receptorexposure to the chemicals of concern for the lagoon sludge,berms, soil beneath the sludge, and soil around the lagoons foreach lagoon area. The emission rates into the air or water fromthe sludge, soils and berms were first calculated, then thetransport through the air and groundwater was evaluated.

A computer program was developed to calculate volatile airemission rates from each lagoon source area. A 70-year averageemission rate was determined for each source area. Air riskswere determined from the downwind concentrations at receptorlocations.

Risks from dust emissions were estimated for exposure by inhala-tion. These risks were estimated as approximately 100 times lessthan the risks from inhalation of volatile emissions. Risks frominhalation of metals within the dust are expected to be less thanrisks from inhalation of organic compounds adsorbed to dustparticles, because metals have hicrher settlinej velocities and are*not. transported as easily.

Chemical emissions from the unsaturated zone to the groundwaterwere also estimated. Simulations were run for each lagoon sourcearea to determine the contaminant mass input to the groundwaterfrom the sludge and soil beneath the lagoons, the sludge only,the soil beneath the lagoons only, the berms, and the soilsaround the lagoons. The 70-year average mass inputs were thencalculated and the results were used as input to a groundwatermodel. The groundwater risks were then calculated using themaximum groundwater concentrations determined with the ground-water model.

Surface water risks were evaluated using average contaminantconcentrations in groundwater expected to enter Big Black Creek,accounting for dilution by clean upstream water and groundwateron the opposite side of Big Black Creek. The dilution rate wasestimated to be approximately 100, therefore, the surface waterconcentrations are 100 times lower than the corresponding ground-water concentration.

10

#V.\y;£$ ^ 'vr" '"*"'"'

The major assumptions used in these models were:

o The contamination is uniformly distributed within the soil orsludge matrix.

o The contaminant of interest is assumed to be bound to eitherthe soil or the sludge.

o The waste does not flow within the carrier matrix,o The adsorption isotherm of the constituent of interest is

linear within the depth of the waste and does not change withtime.

o No flow of gas is induced within the waste matrix,o The diffusion coefficient does not vary with either concen-

tration or time,o The concentration of the constituent of interest in the gas

phase at the surface of the lagoon is much lower than theconcentration of the constituent of interest in the gas phasewithin the waste matrix.

o No diffusion of the contaminant into depths below the wastelayer is assumed,

o Contaminant vapor, waste, solid, and water equilibrium isestablished at all times within the waste matrix,

o Hydrolysis, biodegradation, and ligand formation were assumedto be insignificant mechanisms at this site,

o The aquifer is infinitely wide.

The assumptions made for the risk assessment include:

o People would be exposed to areas where the highest levels ofcontamination were found, i.e., maximum concentrations wereused during the risk assessment to generate risks.

o 70-kg adult resident is exposed daily over a 70-year

o Daily intake is 2 liters per day of groundwater or surfacewater and 20 cubic meters per day of air.

o 100 percent absorption is assumed.

o The groundwater pumping and treatment system is turned off.

These conservative assumptions allow the risk assessment toemphasize health protection.

Toxicitv Assessment

All of the six compounds of concern are known or potential humancarcinogens. Cancer potency factors (CPFs) have been developedby U.S. EPA's Carcinogenic Assessment Group for estimating excesslifetime cancer risks associated with exposure to potentiallycarcinogenic-chemicals. CPFs, which are expressed in units of(mg/kg-day) , are multiplied by the estimated intake of a poten-

11

tial carcinogen, in mg/kg-day, to provide an upper-bound estimateof the excess lifetime cancer risk associated with exposure atthat intake level. The term "upper bound" reflects the conserva-tive estimate of the risks calculated from the CPF. Use of thisapproach makes underestimation of the actual cancer risk highlyunlikely. Cancer potency factors are derived from the results ofhuman epidemiological studies or chronic animal bioassays towhich animal-to-human extrapolation and uncertainty factors havebeen applied. The cancer potency factors for these compounds arepresented in Table 7. RFDs were not used because the carcino-genic toxic effects of the compounds of concern far exceeded thenon-carcinogenic toxic effects.

This table also presents information on whether the compound is aknown or potential carcinogen. As shown in the table, benzeneand benzidine are known human carcinogens (A); the other com-pounds of concern are potential human carcinogens (B2)- Benzi-dine is the most carcinogenic compound and DCB is the second mostcarcinogenic compound of the compounds of concern. Benzidine andDCB are several orders of magnitude more carcinogenic than theother compounds. These two compounds, and particularly benzi-dine, therefore, provide the highest risks at the site and drivethe level of remediation required.

RISK CHARACTERIZATION .

Excess lifetime cancer risks are determined by multiplying theintake level with the cancer potency factor. These risks areprobabilitiesthat are generally expressed in scientific notation(e.g., 1 x 10 ). An excess lifetime cancer risk of 1 x 10indicates that, as a plausible upper bound, an individual has aone in one million chance of developing cancer as a result ofs-n-e-j.ej.aue:u exposure Co a carcinogen over d /u-year i.±zec.imtjunder the specific exposure conditions at a site. Only potentialfuture land use was evaluated since there is no current land use.

Potential Future Conditions - Residential Exposure Scenario

As discussed previously, the site was divided into eight sourceareas and their subareas. The carcinogenic risks were developedfor each of the contaminants of concern for each of thesesubareas for each of the three exposure pathways. A discussionof the risks associated with the future use- residential exposurescenario for each of these pathways are presented below.

Air Inhalation Risks

Air inhalation risks are presented in Table 8. As shown in thetable, these risks range from 1.2 x 10 to 7.9 x 10 , with thelagoon sludge posing the highest risks and berms posing thelowest risks.

12

,<_<»,'• ' < : . ^ j ' i - ' ; • - . . • • ; . - .

Compound

Aniline

Azobenzene

Benzene

Benzidmo

3,3'-Dichlorobenzldine (DOB)

Methylone Chloride

TABLE 7COMPOUNDS OF CONCERN AND CARCINOGENICfTY


Potency Slope (mg/Vg/day)

0.0057

0.17

0.029

.' vi o

3.5

0.0075

EPA Classification

83

Bj

A

A

Ba

A: Known human carcinogen. •

Bz: Known animal carcinogen; Probable human carcinogen (from Risk Assessment Guidance lor Superfund, 1989)

I

Receptor: r = 402.34Azimuth *0

Compound

SLUDGE ONLY

Methylene ChlorideBenzene3.3'-OichlorobenzidineAnilineAzobenzene3enzidineTotal

SOIL BENEATH LAGOONS

Methylene ChlorideBenzene3.3'-DichlorobenzidineAnilineAzob«nzeneBenzidineTotal

BERMS

Methylene ChlorideBenzene3,3'-DichlorobenzldlneAnilineAzobenzeneBenzldineTotalSOIL AROUND LAGOONS

Methylene ChlorideBenzene3.3'-DichlorobenzldineAnilineAzobenzeneBenz'tdineTotal

TABLE 8AIR RISKSBofors Site

Muskegon, Michigan(Azimuth = 0)

Lagoon 1

NDND2.6E-08NDNDND2GE-08

NDNDND3.5E-076.7E-08ND4.2E-07

NDND7.9E-09NDNDND7.9E-09

NDND1.0E-07NDNDND __1.0E-07

Lagoon 3

ND9.2E-064.9E-08NDI.9E-O41.6E-043.6E-G4

ND1.5E-073.6E-081.9E-067.7E-059.4E-051.7E-04

NPNPNPNPNPNPNP

NDND2.7E-061.2E-079.2E-067.8E-061.7E-05

Lagoon 5

.5E-08J.2E-OBJ.3E-08JD7E-05

JO7E-Q5

'-5E-08JDME-08JD;.4E-06-?.8E-05J.2E-05

JPJP

•JPJP

- -jp•JPJP

JDJD..2E-08JD:.7E-06'JD'•.8E-06

Lagoon 6

1.5E-07ND1.0E-08NDt.5E-053.2E-054.7E-05

NDNO1.4E-08ND4.0EO62.6E-053.0E-05

2.9E-07ND1.3E-08ND2.6E-053.6E-056.2E-05

NDND8.4E-08ND8.0E-06ND8.1E-06

Lapoon 7

4.9E-08ND4.4E-O8ND7.5E-06NO __7.6E-06

NDND3. IE-09NDNDND3. IE-09

NPNPNPNPNPNPNP

NDND8.5E-08ND4.3E-07ND5.1E-07

LnQoon 8

5.1E-076.6E-0?6.6E-085.6E-071.5E-057.7E-059.4E-05

NDND3.0E-OQND5-4E-06ND5.5E-06

6.4E-078.5E-0?6.2E-061.6E-068.1E-06ND1.1E-C5

NDND2, IE-087.2E-081.4E-06ND1.5E-06

Lagoon 9

ND6.9E-071.6E-076.6E-054.0E-043.4E-048. IE-04

NDND2.9E-082.1E-062.5E-054.9E-057.6E-05

NPNPNPNPNPNPNP

ND9. IE-056.1E-08ND2.2E-064.0E-051.3E-04

Lagoon 10

ND2.6E-085.0E-084^3E-072.7E-055-4E-058.1E-05

ND4.6E-082.4E-089.7E-072.3E-054.1E-056.5E-05

ND2.0E-082.6E-081.4E-072.0E-05ND2.0E-05

NDND2.8E-077.7E-072.2E-05ND2.3E-05

ND: Contaminant not detected in sample(s) from that lagoon.NP: Media not present in specified lagoon area.specified lagoon area.

c

Groundwater Inqestion Risks

Groundwater ingestion risks are presented in Table 9. Theserisks range from 9.9 x 10" to 3.4.x 10 . Overall, the sludgepresents a total risk of 9.9 x 10 , the soil beneath the lagoonshas a total risk of 6.6 x 10 , and the soil around the lagoonspresents a total risk of 1.7 x 10 and the berms present a totalrisk of 1.2 x 10 . The sludge and soil beneath the sludge posethe greatest overall risk for groundwater ingestion. Totalgroundwater ingestion risks resulting from sludge, soil beneathlagoons, soil around lagoons, or berms are all above acceptablelimits. The highest magnitude of risk is associated withbenzidine. DCB poses the next highest risk.

Surface Water inqestion Risks

Surface water ingestion risks are presented in Table 10. Theserisks assume that the groundwater pumping and treatment system isturned off. The calculated risks range from 1 x 10 to3.4 x 10~ . Benzidine is the chemical which drives the overallrisk for surface water^- Benzidine's combined risk for all sourceareas exceeds 2.5 x'10 . Thus, even though the surface waterposes risks substantially lower than the groundwater, the risksfrom surface water ingestion are above the acceptable range by atleast four orders of magnitude.

Combined Risks

The highest excess cancer risks developed were associated withthe groundwater exposure pathway. The combined carcinogenicrisks reflecting all the contaminants of concern and all_exposurepathways of concern are estimated to be approximately 10 excesscancel rish.. Non-carcinogenic effects are estimated to beinsignificant in this operable unit, since the metals in thesludges and soils do not appear to exhibit significant mobility.If mobile, the non-carcinogenic effects would become significant.Therefore, non-carcinogenic effects were not used to estimate thelevel of remediation required.

Risks and risk-based cleanup criteria should be consideredapproximations due to the limitations and uncertainties of themanner in which these concentrations are computed. When modelingcontaminant transport, when estimation was necessary, a value waschosen to provide the most conservative realistic risk estimate.Tests with the model have shown that contaminant concentrationswithin the soil and sludge have the greatest effect on overallrisks. Other parameters, such as permeability, organic carboncontent, surface area, and volumes may have significant effectson calculated risks.

13

Compound

SOIL AND SLUDGE

MethyJene- ChlorideBenzene3,3-Dichlorobenzldin«AnilineAzobenzeneJenzidin*TotalSLUDGE ONLYMethylene Chlorideienzene3.3-DichlorobenzldineAnilineAzobenzeneJenzidine

TotalSOIL BENEATH LAGOONSMethylene ChlorideBenzene3,3-DichlorobenzidineAnilineAzobenzenelenzldine

TotalBERMSMethylene Chloridebenzene3,3-DichlorobenzidineAnilineAzobenzeneBenzldineTotalSOIL AROUND LAGOONSMethylene Chloride3enzene3,3-DichlorobenzidineAnilineAzobenzeneBenzidineTotal

ND; Contaminant not dNP. Media not present

Uqoon 1

NDND5.9E-05A. IE-072.7E-06ND6.2E-05

NDNO5.9E-05NDNDND5.9E-OS

NDNDND4.1E-072.7E-06ND3. IE-06


NDND1.4E-03NDNDND

TABLE 9EXCESS CAtJCER RISKS FROM GROUNDWATER INGESTION


Laqoon 3 Uqoon 5 Lagoon 6 Lagoon 7

ND5.2E-049.4E-04ND2.4E-061.0E+001.0E + 00

ND2.2E-041.2E-04ND3.6E-073.6E-013.6E-01

ND7.4E-OB1.3E-039.5E-062.4E-06S.4E-015.4E-01

NPNPNPNPNPNPNP

NDND1.4E-034.1E-082.2E-061.2E-03

1.4E-03 2.6E-03

sleeted in sample (s) from that lagoon,n specified lagoon area.

1.6E-092.9E-091. IE-03ND2.7E-067.2E-038.3E-03

7.0E-IO2.9E-096.8E-05ND3.BE-07

6.8E-05

9.0E-10ND7.6E-04NO2.7E-064.5E-035.3E-03

NPNP

.NPNPNPNPNP

ND•JD3.5E-04MD2.2E-06SDJ.5E-04

4.9E-08ND2.2E-04NO5.7E-071.0E-011.0E-01

4.9E-08ND2.8E-05ND1.0E-074.0E-024.0E-02

NDND3. IE-04ND8.0E-078. IE-038.4E-03

6.6E-06ND4.6E-05ND2.2E-071.2E-021.2E-02

NDND1.5E-03ND3.9E-06ND1.5E-03

1.1E-09ND8.4E-04ND1.2E-06ND8.4E-04

1.1E-09ND1.7E-04ND1.2E-06

1.7E-04


NPNPNPNPNPNPNP

NDND2.4E-03ND4.9E-07ND2.4E-03

Laqoon 8 Laqoon 9 Lagoon 10

4.1E-073.4E-062.6E-03ND6.9E-0,ND2.6E-C:;

4.1E-073.4E-063.4E-043.8E-C'1.2E-OC1.3E-011.3E-0'

NOND3.6E-03ND9.4E-OGND3.6E-03

3.3E-C-4.7 E-C '2.9E-C*-:2.6E-ce8.9E-C78.6E-T'8.9E-C::

NDND8.7E-053.6E-072.7E-OCND9.0E-C •

ND3.8E-071.0E-013.4E-045.0E-065.7E-016.7E-01

ND3.8E-072.4E-0434E-048.9E-07S.9E-015.9E-01

NDND6.6E-032.2E-066.6E-064.7E-025.4E-02

NPNPNPNPNPNPNP

ND3.5E-043.6E-03ND3.1E-061.3E-021.7E-02

ND2.9E-093.5E-032.1E-069.4E-062.3E-012.3E-01

ND1.7E-084.8E-046.9E-071.7E-062.4E-012.4E-01

NO1.9E-084.9E-039.4E-071.3E-052.4E-022.9E-02

NO1.8E-085.2E-047.5E-081.6E-062.5E-022.5E-02

NDND1.8E-021.3E-074.3E-05ND1.8E-02

Environmental Risks

Based on the preliminary evaluation performed for the preliminaryrisk assessment, site contamination does not appear to haveaffected critical habitats or endangered species. The Statecompleted a qualitative evaluation of the likelihood and magni-tude of each identified exposure pathway on endangered species.No adverse affects on wildlife were identified in this prelimi-nary assessment.

The wetlands on this site are located in the floodplain on bothsides of Big Black Creek. A portion of these wetlands arelocated within the L.O.U., as shown in Figure 2. These wetlandsconsist of a variety of plant comimini ties with good speci esdiversity. The entire valley area is composed of a complexmosaic of different wetlands, ranging from forested wetlands tosmall ponds. There are mature communities as well as recentlydeveloped wetlands, and wetland formation is still occurringwithin this active floodplain area. These wetlands appear to berelatively undisturbed by site contamination. However, U.S. EPAbelieves that, if the extraction system were turned off, impactto wetlands might occur from discharge of contaminatedgroundwater.

Although an animal study was not conducted on the site, pastexperience indicates that these types of wetlands would supportgood populations of various animal species. The relativelyisolated and undisturbed nature of these wetlands, theirproximity to upland woods, and the continuous band they formalong Big Black Creek indicate potential for supporting goodpopulations of deer, fur bearers, songbirds, migratory waterfowl, herons, eqrets, reptiles, amphibians, and a variety ofxnverutiijiaut;^. Must, jLj.r».e.i.y, Lins weuxdiia Dana aiso serves as apathway for local movement of animals.

None of the wetland types or species encountered on the projectsite are unique or rare in the Upper Midwest. It is possible,however, that individual plant or animal species occurring inthese wetlands may be federally protected or state protectedspecies.

Summary

Actual or threatened releases of hazardous substances from thissite, if not addressed by implementing the response actionselected in this ROD, may present an imminent and substantialendangerment to public health, welfare, or the environment.

14

Compound

SOIL AND SLUDGE

dethylene Chloride•enzene

3,3-DichlorobenzidineAnilineAzobenzeneJenzidino

Total

SLUDGE ONLY

Methylene Chloridetonzene3,3-DichlorobenzidinaAnilineAzobenzenetenzidine

TotalSOIL BENEATH LAGOONS

Methyl«ne ChlorideJenzene3.3-DichlorobenzldineAnilineAzobenzene3enzidineTotalBERMSMethylene ChlorideBenzene3,3-DichlorobenzidineAnilineAzobenzene•JenzidineTola!SOIL AROUND LAGOONS

Methylene ChlorideBenrene3.3-DichlorobenzidineAnilineAzobenzeneBenzidineTotal

Lflooon i

NDND5.9E-074. IE-0927E-06ND6.2E-07


NDNDND4. IE-092.7E-08ND3. IE-08


NOND1.4E-05ND.NOND1.4E-05

TABLE 10EXCESS CANi R RISKS FROM SURFACE WATER INGESTlON

BofofS SiteMusekgon, Michigan

Laqoon 3 Lflqoon 5 Laqoon 6 Lagoon 7

ND5.2E-069.4E-06ND2.4E-081.0E-021.0E-02

ND2.2E-061.2E-06ND3.8E-093.6E-033.6E-03

ND7.4E-101.3E-059.5E-082.4E-085.4E-035.4E-03

NPNPNPNPNPNPNP

NDND1.4E-054, IE-102.2E-081.2E-052.6E-05

OE-109E-U1E-05

JD7E-08.2E-053E-05

.OE-109E-1 18E-07

•JD6E-09

NO•'..8E-07

OE-10'08E-06

no7E-08

-• SE-053E-05

PP

* PPpPp

D. Di 5E-06• 3

2E-0835E-06

4.9E-10ND2.2E-06ND5.7E-091.0E-03t.OE-03

4.9E-10ND2.8E-07NO1.0E-O94.0E-044.0E-O4

NDND3.1E-06ND8.0E-0981E-056.4E-05

6.6E-08ND4.6E-07ND2^E-091.2E-041.2E-04

NDND1.5E-05ND3.9E-08ND1.5E-05

1.1E-11ND8.4E-06NDt.2E-08ND8.4E-06

1.1E-11ND1.7&06NDl E-08ND1.7E-06


NPNPNPNPNPNPNP

NDND2.4E-05ND4.9E-09ND2.4E-05

Le ioon 8

4.1E-C93.4E-082.6E-QSND6.9E-OSND2.6E-05

4.1E-093.4E-083.4E-063.8E-091^E-081.3E-031.3E-03

NDND3.6E-05ND9.4E-08ND3.6E-05

3.3E-104.7E-092.9E-062.6E-1D8.9E-098.6E-0:,8.9E-0:

NDND8.7^-073.6E-092.7E-aND9.0E-07

Lagoon 9

ND3.8E-091.0E-033.4E-065.0E-085.7E-036.7E-03

ND3.8E-0924E-063.4E-068.9E-095.9E-035.9E-03

NDNO6.6E-052.2E-086.6E-084.7E-045.4E-04

NPNPNPNPNPNPNP

ND3.5E-063.6E-05ND3.1E-081.3E-041.7E-04

Lagoon 10

ND2.9E-113.5E-052. IE-089.4E-082.3E-032.3E-03

NO1.7E-104.8E-066-9E-O91.7E-082.4E-032.4E-03

NO1.9E-104.9E-059.4E-091.3E-072.4E-042.9E-04

ND1.8E-105-2E-067.0E-101.6E-082.4E-032.4E-03

NDND1.8E-041.3E-094.3E-07ND1.8E-04

ND: Contaminant not detected in sample(s) from that lagoon.NP: Media not present in specified lagoon area.

•--•'•'• ——

FEASIBILITY STUDY ISSUES

Remedial Action Objectives

To evaluate the effectiveness of the technologies assessed in thetreatability study, the groundwater ingestion risks were used toestimate the post-treatment chemical concentrations necessary tomeet specified risk levels. As described previously, the ground-water ingestion route of exposure poses the greatest risks to humanhealth and the environment.

The cleanup criteria developed in the RI using EPA guidancegforrisk based cleanup criteria are presented in Tables 11 (10 Risk)

— U , ,.and 12 (10 Risk). However, on July 11, 1990, State of Michiganadministrative rules were promulgated pursuant to Act 307, p.a.1982 that require a modification of these levels. The Act 307cleanup criteria for the sludge, berms and soil are based upon a10-6 risk concentration calculated using methods presented in Act307 rules. The concentrations for the compounds of concern are:Methylene Chloride, 100.0 ug/1; Benzene, 20.0 ug/1; 3,3' -Dichlorobenzidine, 2.0 ug/1; Aniline, 120.0 ug/1; Azobenzene, 6.0ug/1; Benzidine, .004 ug/1.

In the event the analytical detection limit for these compounds isabove Act 307 risk based cleanup level, the analytical method thatcan achieve the lowest method detection limit which can be measuredand reported with 99% confidence, will be used to determine thecleanup criteria. If the compound is not detected the criteriashall be ouiitoj.utii.eu LU jje achieved. The modified cleanup criteriaare not expected to have an effect on the scope or cost of theremedy.

Tne mass oi eacli contaminant in each lagoon subarea was calculatedfrom the RI data and the distribution of each compound in each ofthe four types of subareas were calculated, as presented inTable 13. As shown in this table, the sludge and berms account for64 percent of the contamination by the compounds of concern. Thesoils under and around the sludge account for 36 percent of thecontamination by the compounds of concern. Benzidine drives theremediation because of its extremely high toxicity. Of the totalbenzidine distribution at the site, 83 percent is present in thesludges and berms. These figures clearly indicate that themajority of the contamination is present in the sludges and bermsand that the soils beneath and around the sludge are significantlyless contaminated than the sludges and berms.

Applicable or Relevant and Appropriate Requirements

Section 121(d) of SARA mandates that, for all remedial actionsconducted under the CERCLA, cleanup activities must be conducted ina manner that complies with applicable or relevant and appropriaterequirements (ARARs). The NCP and SARA have defined bothapplicable requirements and relevant and appropriate requirementsas follows:

UnlU:ppb TABLE 11 .SOURCE CONTROL CLEANUP CROB»A TO ACHIEVE W* FBSKS

BoJonSlttMutUgon, Michigan

GROUNOWATER WGESTJON

Compound

UMhytan* Chtorid*

B«ru«na

3.3--Otch»orob«nild%>«

Anttn»

AzobMU*n*

BwnildiM

Lagoon 1

SL

NO

ND

3lcjci$$!NO

NO

NO

SB

NO

NO

NO

NA

**e:&sNO

SL&SB

NO

NO

aeofQ)NA

i<>aiii|<;NO

SA

NO

NO

«qp&NA

NO

NO

B

NO

NO

IJPCINO

NO

NO

Lagoon 3

SL

NO

4500

30800(0]

NO

NA

BDMi ej

: B

NO

NA

39&-)(0)

97C

420 0

aocnofS

SL&SB

NO

790

39600(0)

560

2.3*10S

90600 (JOJ

SANO

NO

30600(0)

NA

49000

woolP

B

—_

—

—_

—

Lagoon B

SL

NA

NA

3**HNO

NA

NO

SB

NA

NO

30000(0)

NO

2000

t«$Wl

SL&SB

NA

NA

39600(0)

NO

24000

v&m

SA

ND

NO

39600(0)

ND

1700

NO

B

_

—

_

-

—_

Lagoon C

SL

NA

NO

30800(0)

ND

NA

(bobolif

SB

NO

ND

30000(0)

ND

NA

SL&SB

NA

ND

36*0(0)

NO

NA

ifpwijjl

SA

NO

NO

»wi.(6yNO

1000(0)

NO

B170

NO

38800(0}

NO

NA

mmGROUNDWATERINGESTON

CompoundLagoonT

SL SB SL&SB SA

Lagoon 6

SL SL&SB SA

Lagoon 9

SL SB SL&SB SA

Lagoon 10

SL SB SL&SB SA

NA NO NO NA NO NA ND ND NO NO NO NO NO NO NO NO

town* NO NO NO ND 820 NO ND NA ND NA 825(0) NA NA NA ND NA

30800(0) 39800 (O) 7100 39800(0) 48000 3*800(0) 30600(0) 39600(0) 30800(0) 880 (0) 880(0)

AnHn* NO NO NO NO NA NO NA 30000 (O) 4900 2800 ND 2900 NA 1200 NA NA

taooo NO 28000 1000(0) 2700 NA 400000 10OO(O) 3800 10000 1000(O) 70000

8*nxldin« NO ND NO ND 1000 (Of NO TOCO PJ NO

NA:

NO:SL:SB:

SL&SB;

SA:

B:

Not •pottubte; ctMnup eonconlmUora hioh*/ ih*n concMiraUOM d*t*ci«d tn Hmpto.

Not d«t«ct*d tn ortginal Mmpto.

Sludoi.

SoU twnMth lagoon.

Sluog* v>d wll b*nMlt) lagoon combtn«d.

Soil wound lagoon.

B*im.IndtcaiM •Hpo*ur« rout*, compound, and d*anup Uandan) Mhkh drhw i•mvdlalion, b«»*a on rttk».

Cleanup crttana it analyUcaJ quantltailon limR tor the compound.

I

UnM»: ppto TABLE 12SOURCl ONTnOLCLEANUPCRrTERlATOACHlEVElO''<raSKS

BofonSlt*Muikagon, MlcNg»n

GRQUNDWATER INGESTION

Compound

M*thyt*n« ChlofW*

9*ni*n*

S. -DkJikMOb^rUfdln*

Anllln*

AtobvniBn*

Bcnifdln*

Lagoon 1

SL

NO

NO

NA

NO

NO

NO

SB

NO

NO

NO

NA

J400 ••;.;:-.-;:

NO

SL&SB

NO

NO

NA

NA

»W-:-;:;-:----NO

SA

NO

NO

t98JL".;.-:;-*

NA

NO

NO

8

NO

NO

NA

NO

NO

NO

L*aoon3

SL

NO

450000

690000

NO

NA

80000 (O)

SB

3

\

aoo\*tt»|0i

SL4SB

NO

79000

100000

NA

NA

60000(0}

SA

NO

NO

190000

HA

NA

liba-jor,-

B

—

__

_

__

__

—

UgoxiS

SL

NA

NA

NA

NO

NA

NO

SB

NA

NO

3MOO(Q)

NO

NA

ioob';(QF::

SL&SS

NA

NA

39000 (O)

NO

HA

t'ooaipN

SA

NO

NO

39000(0^

NO

NA

NO

8

_

—

—

_

—

—

UgoonASL

NA

NO

NA

NO

NA

90009(0}

3S

NO

NO

130000

NO

NA

jbba f-

SL4S8

NA

NO

UOOOO

NO

NA

iiootfiitS?

EA

NO

NO

»*»PNO

NA

NO

B

NA

NO

NA

NO

NA

itbiJapfr-

GROUNOWATEH INGESTION

CompoundUgoan?

SLAS8 SA

L*goonS

SL S8 SL&SB SA

Lagoon D

SL SB SL1SB SA

Lagoon 10

SLJ.SS SA

CMond* NO NO NA NO 9100 NO NO NO NO NO NO NO NO NOB«ni«n« NO NO NO NO NA NA NO NA

1SOOOD 4400OO 30000(0) 20OOOQ 39800 (O( 39000(0) 39000 (Ot 200000

NO NO NO NA 1.1X10° NO

NO NA NA

NO NO NO NO 80000(0) JopojCj- NO 1000 Pt 60000 (O- iDDq(O> aoboo (Qy NO

NA:

NO:SL:SB:

SL4SB:

SA:B:

Not 'pp^tfr^: cl«*nup cone*ouniooi hlgnw than conc*nlruiont dat*ct»d m MmpU.

Not dai«cl*d In ortgkut umpl*.

Sludga.

Sol bMMath tigoon.

SKidg* and •«• b»n««m Ugoon comblMd.

So* uound l*goon.Bwm.Indttaln *>po*ur» rout*, compound, and dacnup tfwtdwd* *rfikh driv* r«mMIUIon.

Ctanoop cfltvrta ll In* «d«lyttc»l qv«*H««ilon Hmtt for tn* compound.

TABLE 13coNTAf. NANT MASS DISTRIBUTION BY SUBAREA

Bofors siteMuskegon, Michigan

Units: mg/kg (ppm)

Total Mass Percent Mass

SL SB B SA SL SB B

Methylena Chloride 43.0 0.1 3.7 - 92.0 % 0.2 6.0

Benzene 7782.3 2-0 - 10209.8 43.0% "0.0 0.0

DCS 2712333.0 24171.0 M905-0 253513.0 48.0% 4.0 4.0

Aniline 38770.8 626.6 14.8 132.0 98.0 % 1.6 "*0.0

Azobenzene 188478.8 16193.4 2264.8 4250.3 88.4% 8.5 1.1

Benzldine 406M.5 8122.6 203.2 121.1 B2JL%. I&5 QA

Percent of Total Mass 61.5% 5-7% 2.6% 30.1%

LEGEND:

SL Sludge.

SB: Soil beneath lagoon.

B: Berm.

SA: Soil around lagoon.

SA

0.0

57.0

44.0

0.3

2.0

JL2

o Monitoring groundwater and surface water, 'Samples fromexisting monitoring wells would be collected to assess theeffectiveness of the remedial action, if applicable. Sampleswould be collected four times during the first year ofmonitoring and twice annually in subsequent years. Tomonitor surface water quality, samples from two locationswould be collected in Big Black Creek. The surface watersamples would be collected on four occasions during the firstyear of monitoring and twice annually in subsequent years.

Remedial Alternatives 2, 3, and 4 contain the following addi-tional components:

o Constructing on-site roads. About 4,500 feet of roads wouldbe constructed on the site, primarily near the sludgelagoons, to accommodate truck traffic on the site during theremedial action cleanup.

o Monitoring air. Air samples would be collected from the workzone and perimeter of this site during excavation of thecontaminated material. Air samples would also be collectedto measure the potential emissions from the treatment facili-ties. These samples would be collected from the facilitystack and from the site perimeter. The frequency of samplingwould be determined prior to construction.

o Groundwater pumping and treatment. The groundwater iscurrently being pumped using the existing groundwater extrac-tion system. For this remediation, the pumping system wouldbe upgraded and the distribution system would be relocated toaccommodate excavation and treatment of the lagoons. A newtreatment system would be built. Treatability studiesj.uu.L'-tiL-ciu unaL u^uiie treatment wo.il acaieve ettiuent concen-trations below detection limits. Therefore, the groundwaterwould be treated using an ozone oxidation treatment system ora system that achieves equivalent performance. The treatedeffluent would then be discharged to Big Black Creek.Although a National Pollutant Discharge Elimination System(NPDES) permit is not required because treatment and dis-charge of the effluent occurs on-site, the substantiverequirements of the permit will be met. The proposed BestAvailable Technology (BAT) discharge standards for theindicator chemicals are as follows: Methylene Chloride, 5.0ug/1; Benzene, 5.0 ug/1; DCB, .06 ug/1; Aniline, 4.0 ug/1;Benzidine, .04 ug/1; discharge standards for Azobenzene arein the process of being developed. The groundwater treatmentsystem will be operated to achieve these standards*

18

Alternative 1; No Action

The no action alternative involves leaving the L.O.U. contaminantsource areas intact and terminating operation of the existinggroundwater pumping and treatment system which currently controlsgroundwater migration off-site. Groundwater and surface watermonitoring will be performed semiannually to evaluate impacts ofterminating operations of the groundwater pumping and treatmentsystem. Therefore, the potential for release of contamination toair, groundwater, and surface water pathways and for exposure tocompounds above acceptable risk levels will continue to exist.This alternative will not meet target risk levels and no reduc-tion of toxicity, mobility or volume of site contaminants willoccur. Risk levels predicted for this alternative are 10 forthe air inhalation pathway, 10~ for the groundwater ingestionpathway, and 10 ,for the surface water ingestion pathway, for atotal risk of 10" . This alternative is included as a NCPrequirement and also to provide a baseline against which otheralternatives may be compared.

Alternative 2: Cap. Institutional Controls. Pump and TreatGroundwater Perpetually

The components of this alternative are presented in Figure 3.The components presented in this figure are approximate and maybe modified during design or construction.

Treatment Components

There is no treatment of the sludges and soils in this alterna-tive. Fluids generated from sludge compaction during theconstruction of the cap will be treated in the qroundwater treat-iuoiiu t j j foucw. j.iij.0 .ita eat-AiuaUeu t-i_> u« o . i , illj. j. i iUii *j a j. j.i_U I ;=> uvei atwo-year period. The groundwater will be pumped and treatedperpetually using an ozone oxidation or equivalent treatmentsystem. Treatment levels will be determined in the next operableunit.

Containment Components

All eight lagoon source areas (Lagoon Areas 1,3,5,6,7,8,9,10)will be capped (approximately 23 acres of contaminated sludgesand soils). The cap, designed to meet the intent of RCRA Sub-title C, and constructed to meet U.S. EPA guidance provided in40 CFR 264.310, will consist of an upper 2-foot vegetated soillayer underlain by filter fabric and a 12-inch sand layer over alow permeability layer. The low-permeability layer will becomposed of a synthetic liner (minimum thickness of 20 mil) overa 2-foot compacted clay layer (i.e., soil liner) with a permea-bility less than or equal to 1 x 10-7 cm/sec.

19

To reduce water and wind-borne migration of contaminants off-site, erosion controls will be used. As needed, dust suppressiontechniques will be used to reduce airborne contaminant transport.After the initial grading of the site, the area to be capped willbe further prepared. Initially, a foundation layer will beformed using local or imported material capable of structurallysupporting the weight of the cap. This material will be spreadand graded to form a smooth subgrade prior to cap placement.Final grading of the subgrade will be performed in accordancewith the proposed cap grades to provide positive surface drainageoff the cap. A drainage system will be constructed to collectconsolidation leachate.

The minimum post-compaction slopes for the cap will be 5 percentwhere attainable; the maximum cap slope will be 25 percent. Thefinal capped area will rise approximately four feet aboveexisting grade. Stability of the soils on-site is not expectedto be a problem for the cap design for most of the site.However, based on geotechnical testing, the sludges consist oflow-strength, highly compressible materials. These constructionconcerns have been taken into account in the cap design and costestimate. After final grading is complete, the cap will befertilized, seeded, and mulched to promote vegetative growth.Drainage pathways will be established to divert surface waterrunoff away from the capped area on a permanent basis.

Groundwater Components

The groundwater is currently being pumped using an existinggroundwater extraction system. For this remediation, the pumpingsystem would be upgraded to increase performance efficiency andthe distribution system would be relocated to accommodate excava-tion and treatment of the lagoons. As previously mentioned, anew treatment system would be built, using an ozone oxidationtreatment system or equivalent system to treat the groundwater.The treated effluent would then be discharged to Big Black Creek.In this alternative, the groundwater will be pumped and treatedperpetually to contain the groundwater plume.

General Components

This alternative addresses all of the contaminated soils andsludges in this operable unit through containment using cappingand groundwater extraction. Capping the eight source areas willreduce air emissions and reduce infiltration of precipitation andcontaminants into the groundwater. However, the reduction ininfiltration will not be sufficient to achieve 10 risks forgroundwater or surface water ingestion. Therefore, the existingpump and treat system will be operated perpetually and willcontain the groundwater contaminant plume to prevent groundwatermigration off-site and subsequent surface water contamination.Institutional controls limiting on-site access and groundwater

20

Figure 3C< mponents of Alternative 2

4

All Source Areas;23 Acres of

ContaminatedSludge & Soil

Capping withRCRA Subtitle

Cap

Organic Compounds (ppb):Methylene Chloride: NO-2200Benzene: ND-980,000Aniline: ND-3.900,000Azobenzene: ND-12,000.000Benzidine: ND-3,400.000DCS: ND-3.500,00010-1 Carcinogenic Risk Level

GradingCap Constru1 ion

Upgrade PresentSystemPerpetual Operationto Contain PlumeCleanup Criteriafor GroundwaterDetermined in FinalOperaDle Units

Leachate generatedfromcompaction duringconstruction

ContaminatedGroundwater

GrounoXaterExtraction

Ozc ation

EQU a lentTr6t rnent

Discharge StandardsEffluen: Determmed in Final

Operable Unit

Discharge toBig Black

Cr -ek

• Long-term O&M - groundwater monitoring- cap integrity monitoring

• InstitutionalControls - deed restrictions on groundwater use

- access restrictions• 10-6 carcinogenic risk level assuming no failure of purge well system,

cap or institutional controls• $12.091,000 Capital• $429,000 Annual O&M• $19.890.000 Present Worth

10-6 Carcinogenic LevelSI,218.000 Capital$357,000 Annual O&M

Time Until Cleanup Goals Wet Capping

= 2 years

Groundwater

use will also be incorporated to prevent future-development, siteaccess, and use of the contaminated groundwater. Placement ofthe cap will involve alterations to the wetlands in source area10.

This alternative is estimated to achieve a risk of 10 , assumingthe cap, groundwater extraction and treatment system, andinstitutional controls are successfully maintained. Thisrepresents a five order-of-magnitude reduction in risk from the10 initial risk.

The cap-will require periodic inspection and repair. Periodicsampling, inspection, and maintenance of groundwater monitoringwells and the groundwater extraction system will be required. Asnoted previously, the cap will be constructed to meet the intentof RCRA Subtitle c. Although RCRA is not applicable or relevantand appropriate for this operable unit, the level of technologyrequired by RCRA is proposed to be used to provide an increasedlevel of protection.

Institutional controls on groundwater use and site access may bedifficult to enforce-over an extended time period. There issignificant uncertainty over the likelihood that the institu-tional controls, the cap, and the groundwater extraction andtreatment system will be operated, maintained, and enforcedforever.

The costs and estimated implementation time frame for Alterna-tive 2 are:

Capital: $12 millionAnnual O&M: $429,000i-j.tiUciiL r. i i_u. :?<;0 millionEstimated Implementation Time: 2 years

ARARs

Alternative 2 will comply with the substantive requirements of anNPDES permit (Clean Water Act), which is an applicable ARAR.Since wetlands on the north side of Big Black Creek will beimpacted during the construction of this alternative, thesubstantive requirements of a 404 permit will need to be satis-fied, as well as the requirements of the State Wetland ProtectionAct, also applicable ARARs. The State Soil and Erosion Act isrelevant and appropriate to this alternative, which is expectedto comply with the requirements of this ARAR. The Clean Air Actand State Air Pollution Control Act are applicable to thisalternative during construction of the cap. This alternative isexpected to comply with the requirements of these ARARs. TheSafe Drinking Water Act is a relevant and appropriate ARAR andthe State Water Resources Commission Act is an applicable ARAR tothis alternative because of discharge of treated groundwater to

21

Big Black Creek. The requirements of these ARARs are anticipatedto be met by this alternative. According to the State ofMichigan, the Michigan Act 307 requirements may not be met.

Alternative 3; On-Site Incineration/Low Temperature ThermalDesorption. Cap. Pump and Treat Groundwater

Alternative 3 consists of combined treatment and containmenttechnologies directed toward removal and treatment of the mostcontaminated sludges, and capping of less contaminated sludgesand soils. The components of this alternative are presented inFigure 4. The components presented in this figure are approxi-mate and may be modified during design or construction.


Source Areas 3 and 9: Sludge, berms, and soils under the sludgewill be excavated and incinerated on-site. Low-temperaturethermal desorption (LTTD) may be used on either or both of thesesource areas or subareas if pilot-scale testing indicates accep-table performance by achieving the cleanup criteria. LTTD is avolume reduction technology that removes contaminants from thesludge or soil by volatilization and concentrates the contami-nants in an aqueous phase which is then treated. This technologycan provide a less-expensive alternative to incineration whenthere is sufficient performance to achieve cleanup criteria.

Source Areas 6 and 8: Sludge and berms will be excavated andincinerated. On-site LTTD may also be used on either or both ofthese source areas or subareas if pilot scale testing indicatesacceptable performance.

Source Area 10: Slurtn** **H b ** v." "* 1 be exccr ' .1 ;.:._ ',_on-site using LTTD.

Fluids generated during the construction of the cap from sludgecompaction in Source Areas 1, 5, and 7 will be treated in thegroundwater treatment system.

Fluids generated during LTTD will be treated on-site using thegroundwater treatment system. Scrubber water from the incinerator will be treated by precipitation or equivalent treatment,Filter cake from filtering the LTTD wastewater will be incine-rated in the on-site incinerator. The groundwater beneath thesite will be collected and treated using ozone or equivalenttreatment .

22

Figure 5

0,M»3-WDC

SourewAnM* 1. 5 and 7Sod EfCivaoon

c omponents

nr*"» Ch'onOa NO-18

3 NO-930.000

of Alternative 4

AOf*- 1* Oitoo»*J

In P' *U SuMS* CLa^Ofafl

8*niK*n« NO-;. 100

8Source Arm 3. 6.

9. md id Soit AroundLagoon i

151.800 yd*

Sott EiCBVMfcM

an« Contaminant* (pod)CMorvM- NONO-120000

OC9: 7.100-J. 700.000Antar N0-3.*00

790-49000ina NO-7300

Sour* ATM* 3. S.a. 9. *td to Sari! 8^

KM, 100 yd*

NO

OC8; 7.100-MOOOOOAfMvw NO-9,800AfDOMi«n> <i 30O-I 000000B«na<*n» NO-MO 000

, 8. 8 9Residual A$n

MO-2 200Btritww NO-980000OCB 10.500-J.900.000

NO-J900000« 16.500-12.000.000SSOO-sJ 400.000

GmunatrmmrEincton

• Syt 1*m OwnlM UrrM OraundwaWr D.** Un"

OAM

- groundwater monitoring- cap and liner

integrity monrtoring

10-* carcinogenic risfc level

J&5.752.000 Cap«afU13.000 Annual OSM

S70.874.MO PrtUffl Worth

• 1357.000 Annual O1W

Time Unui Cleanup Goals Wet jncinefanon/LTTQ and Langtillinq-5

Gnsuncfwater————>Finite Penod

The costs and estimated implementation time frame for Alterna-tive 3 are:

Capital: $74 millionAnnual O&M: $344,000Present Worth: $80 millionEstimated Implementation Time: 5 years

ARARs

The ARARs presented for Alternative 2 also are pertinent to thisalternative. In addition, air emissions requirements concerningconstruction of equipment that may be a source of air emissionsin the Clean Air Act and Michigan Air Pollution Control Act areapplicable to this alternative. RCRA is a potential ARAR forthis alternative if the ash tests positive as a RCRA characteris-tic waste. According to the State of Michigan, this alternativedoes not satisfy Michigan Act 307 requirements.

Alternative 4: On-Site Incineration/Low Temperature ThermalDesorption. On-Site Landfill, Pump and Treat Groundwater

Alternative 4 also consists of combined treatment and containmenttechnologies directed to treatment of the most contaminatedsludges and landfilling of less contaminated sludges and soils.The components of Alternative 4 are presented in Figure 5. Thecomponents presented in this figure are approximate and may bemodified during design or construction.


Source Areas 3. 6. 8, and 9: Sludge and berms will be excavated— — <-*— -» -j jj j. i L> it uW Ll^ji_i_i v_*li wii_;-jt— o t^ u .1. i~< C i_i .1. ij: i_i L>

if pilot-scale testing indicates acceptable performance.

Source Area 10: Sludge and berms will be excavated and treatedon-site using LTTD.

Fluids generated during LTTD will be treated on-site using thegroundwater treatment system. Filter cake generated during LTTDwill be incinerated on-site. Scrubber water from the incineratorwill be treated by precipitation or equivalent treatment.Landfill leachate will be treated in the groundwater treatmentsystem.

The groundwater from beneath the site will be pumped and treatedusing ozone or equivalent treatment.

24

'Tip:

Containment Components

All material in Source Areas 1, 5, and 7, including sludge,berms, and soils, will be excavated and placed in an on-siteRCRA-type landfill. The ash from incineration and LTTD (SourceAreas 3, 6, 8, 9, and 10) will be placed in the on-site RCRAlandfill. Soils beneath and around the lagoons in these sourceareas will be excavated and also placed in the landfill. Theapproximate location of the landfill is presented in Figure 6.

Groundwater Components

The groundwater component for this alternative is the same asdescribed in Alternative 3.

General Components

This alternative also addresses all the contaminated sludges andsoils in this operable unit through a combination of treatmentand containment. The risks remaining after remediation usingthis alternative are estimated to be 10~ . This alternative willrequire the excavation and treatment of approximately 100,800 yd3of sludge and berms and landfilling of approximately 18,700 yd3of sludge. The approximate volume of soil to be landfilled is334,700 yd3. The volume of ash from incineration and LTTD thatwill be landfilled is 73,100 yd3. The total volume of materialthat will be landfilled is approximately 426,506 yd3. Thelandfill will occupy approximately 8 acres. A minimum of 12-feetseparation between the landfill base and the water table will beprovided. Landfilling of soils in source area 10 will impact theexisting wetlands.

Ani^ .w L . tiit>j t;t>L.-LILHAi_eu -Lnipj.ciiie:iiUciCjLwii uj.uit_ frame for Alterna-tive 4 are:

Capital: $65,752,000Annual O&M: $313,000Present Worth: $70,874,000Estimated Implementation Time: 5 years

ARARs

The ARARs presented for Alternative 3 also are pertinent to thisalternative except Michigan Act 307 requirements would be met.

SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The following nine criteria were used to evaluate the fouralternatives:

1. Overall protection of human health and the environment:addresses whether a remedy provides adequate protection and

25

Approximate Landfill Location

Figure 6 Location of RCRA Landfill

$3TOWW«TO^^

' . LI - :c£----. —L!._!_HI. n Hi nut •-—--^—-

describes how risks posed through each pathway are elimi-nated, reduced, or controlled through treatment, engineeringcontrols, or institutional controls.

2. Compliance with applicable or relevant and appropriaterequirements (ARARs): addresses whether a remedy will meetall of the ARARs of other Federal and State environmentallaws and/or justifies a waiver.

3. Long-term effectiveness and permanence: refers to expectedresidual risk and the ability of a remedy to maintainreliable protection of human health and the environment overtime, once clean-up goals have been met.

4. Reduction of toxicity, mobility, or volume through treatment:is the anticipated performance of the treatment technologiesa remedy may employ.

5. Short-term effectiveness: addresses the period of timeneeded to achieve protection and any adverse impacts on humanhealth and the environment that may be posed during theconstruction and implementation period, until clean-up goalsare achieved.

6. Implementability: is the technical and administrative feasi-bility of a remedy, including the availability of materialsand services needed to implement a particular option.

7. Cost: includes estimated capital and O&M costs, as well aspresent-worth costs.

8. State Acceptance: is used to indicate the state's comments.

y. community Acceptance: summarizes the public's generalresponse to the alternatives described in the Proposed Planand RI/FS Report. The specific responses to public commentsare addressed in the Responsiveness Summary section of theROD.

Threshold Criteria

Overall Protection of Human Health and the Environment

Alternative 1 provides no protection, sincefino action is taken.Alternative 2, even though it attains a 10 risk, is the nextleast protective because no treatment of the principal threat isincluded in the alternative. If failure of the cap, institu-tional controls, or pump and treat system occurs because theoriginal source is still present, the site could return tocurrentfirisk levels. In addition, in this alternative, achievingthe 10 risk estimate assumes that institutional controls andgroundwater pumping and treatment will be maintained forever, an

26

unlikely event. Alternative;3 is,more protective than Alterna-tive 2 because of the treatment of sludge, berms, and soils, andthe finite groundwater pumping and treatment period. However,Alternative 3 presents a 10~ risk, two orders of magnitudegreater excess cancer risk than Alternatives 2 and 4. Thisgreater residual risk is due to the use of capping only as acontainment technology, rather than in combination with perpetualgroundwater pumping and treatment. Alternative 4 is the mostprotective because it provides treatment of highly contaminatedmaterials, high degree of containment of less contaminatedmaterials through landfilling rather than capping, and does notrequire perpetual pumping and treatment of groundwater.

Compliance with ARARs

The substantive provisions of the following have been identifiedas ARARs for this operable unit:

Federal:

o Clean Water Act (33 U.S.C. 1251)o Clean Air Act (42 U.S.C. 7401)o Flood Plain Management and Protection of Wetlands (42 U.S.C.

4321)

State:

o Water Resources Commission Act (ACT 245)o Goemaere-Anderson Wetland Protection Act (ACT 203) •o Michigan Environmental Response Act (ACT 307)o Soil Erosion and Sedimentation Act (ACT 347)o Air Pollution Act (ACT 348)

The following have been identified as potential ARARS for thisoperable unit:

o Resource Conservation and Recovery Act (42 U.S.C.6901)o Safe Drinking Water Act (42 U.S.C. 300(f)

Federal

The Clean Water Act (CWA) regulates the chemical, physical, andbiological integrity of surface waters. Under Title III and IVof this act, effluent standards and permits are required to beestablished and applied to discharges to surface waters.Section 404 of Title IV specifically regulates the discharge ofdredged or fill material into surface waters, including adjacentwetlands. Title 40, Part 129 of the Code of Federal Regulations(40 CFR 129) establishes effluent standards and ambient watercriteria for certain toxic pollutants, including benzidine.

27

Alternative 1, the no action alternative, will*.affect-.the-waterquality of Big Black Creek, a recreational-use stream, since thisalternative involves the discontinuation of the groundwaterpumping and treatment system. Alternatives 2, 3, and 4 includepumping, treating, and discharging groundwater on-site to the BigBlack Creek. Therefore, this regulation is applicable to all thealternatives for the L.O.U. 40 CFR 122, 125 and 136 establishguidelines and procedures for the National Pollutant DischargeElimination System (NPDES). The NPDES program is a nationalprogram for issuing, monitoring, and enforcing permits for directdischarges. The substantive requirements of these regulationsmust be met for on-site discharges. Therefore, the substantiverequirements of these regulations are applicable to Alterna-tives 2, 3, and 4.

40 CFR 230 regulates the disposal of dredged or fill material insurface water and wetland areas. Alternatives 2, 3, and 4 -involve excavation and other remedial activities in the wetlandarea. Therefore, the substantive requirements of this regulationare applicable to these alternatives. The MDNR has assumedadministration over the wetlands in the State of Michigan becauseof Act 203 and several other environmental statutes whichincorporate these Federal requirements. However, the Federalgovernment retains the authority to review and comment.Section 10 of the Federal River and Harbor Act, as amended,regulates the obstruction or alteration of any navigable water inthe United States. The jurisdiction of navigable waters includesconnected wetlands. Alternatives 2 and 3 include activitieswhich will cause alterations in the wetland area of the Big BlackCreek by capping the wetlands in Source Area 10. Alternative 4includes activities which will cause alterations in the wetlandsby excavating the wetlands in Source Area 10. Therefore, thesubptant 1 VP r°rmi r^^^nt1^ of ">"> '"T"r> "^0 through 330 may beapplicable to these alternatives.

The Safe Drinking Water Act (SDWA) of 1974, as amended, wasenacted to assure high water quality in public water systems.The National Primary Drinking Water Regulations specify themaximum contaminant levels (MCLs) and the maximum contaminantlevel goals (MCLGs) for public water systems for inorganic andorganic chemicals. The surface water in Big Black Creek is notcurrently distributed through the public water supply systems.Therefore, these regulations are not applicable to the site.However, the surface water is a potential source of drinkingwater. Therefore, these standards may be relevant andappropriate for Alternatives 1, 2, 3, and 4. Benzene is the onlycompound of the compounds of concern which has a MCL and MCLG.According to the final NCP, MCLGs which have values of zero arenot relevant or appropriate at CERCLA sites (55 FR 8751).Since the MCLG for benzene is zero, this standard is notrelevant or appropriate to the L.O.U. The MCL for benzenefiis5 ppb, which is equivalent to an excess cancer risk of 10~ .

28

Lagoon 3 soil and sludge and Lagoon 9 soil around the lagoon mayresult in an excess cancer risk of benzene in surface water atthe same order of magnitude as the MCL. Based on this informa-tion, Alternative 1, the no action alternative, may not complywith MCLs. However, Alternatives 2, 3, and 4 are expected tocomply with MCLs.

The Clean Air Act (CAA) was enacted to protect and enhance airquality. 40 CFR 6 rerr»i>-ns that al1 ^•-•deral projects, licenses,permits, plans, and financial assistance activities conform toany State Air Quality Implementation Plan (SIP). This require-ment is action specific and therefore, is applicable to Alterna-tives 2, 3, and 4. 40 CFR 50 establishes primary and secondaryambient air quality standards. Since these requirements regulateambient air quality, these rules are applicable to all thealternatives. It is expected that all the alternatives, exceptAlternative 1, will be able to attain primary and secondary .airquality standards. 40 CFR 60.50-54 specify emission standardsfor newly constructed incinerators. These rules are onlyapplicable to Alternatives 3 and 4 which include incineration ofsoil and/or sludge and berms as part of the remedial alternative.These alternatives are expected to comply with 40 CFR 60.50-54rules. 40 CFR 61 specifies national emission standard forhazardous air pollutants from stationary sources. The hazardousair pollutant at this site specified under these regulations isbenzene. This regulation is applicable to Alternatives 3 and 4which contain treatment systems for the groundwater, soil, and/orsludge and berms which may emit hazardous air pollutants.

U.S. EPA's policies and procedures for implementing ExecutiveOrders 11988 (Floodplain Management) and 11990 (Wetlands Protec-tion) and the Fish and Wildlife Coordination Act are provided in40 CFR fi. The nrorprhlT**3^ nrr>wMr.H i « * n rrr» f »_„,-,„ j ,•.. •» ^suostancively require that U.S. EPA conduct its activities toavoid long- and short-term adverse impacts associated withactions in the wetland or floodplain areas. Because Alterna-tives 2 and 3 involve capping in a portion of the wetland areaand Alternative 4 involves excavation in a portion of the wetlandarea, compliance with the Wetland Act must be met for thesealternatives and will require close interaction with the appro-priate regulatory agencies.

The Resource Conservation and Recovery Act (RCRA) is a potentialARAR for Alternatives 3 and 4. After treatment in these alterna-tives, the resulting ash may exhibit the characteristic oftoxicity for metals through TCLP testing, since metals may beconcentrated in the ash and their mobility increased. This willbe confirmed during the design phase. If the ash is a RCRAcharacteristic waste, then Alternatives 3 and 4 must comply withRCRA regulations concerning disposal.

29

^

State • •' ; • . . » • ••(-. nf*rf~ ^: « • • - • ' • '*The Water Resources Commission Act was established to protect thewater quality of Michigan. Part 4 rules establish surface waterquality standards and regulate discharge to surface water bodies,since surface water quality would be affected by the no actionalternative, Alternative 1 does not comply with these waterquality requirements. Alternatives 2 through 4 include ground-water pumping and treatment followed by discharge to Big BlackCreek, a recreational-use stream. Rule 323.1057 (Rule 57) ofPart 4 establishes standards for toxic substances. Standards fortoxic substances are established on a site-specific basis.NPDES permits are regulated by the State under the Part 4 WaterQuality rules. Because all remedial activities occur on-site,permits are not required? however, the substantive requirementsof the NPDES permit will be met.

Act 203, the Goemaere-Anderson Wetland Protection Act, applies toactivities that result in discharge to the wetland area thatdrains to the Big Black Creek. In Michigan, the MDNR has juris-diction over the wetlands. All the alternatives result indischarge to, excavation, or grading of a portion of the wetlandarea of.the Big Black Creek south of Lagoon 10 in some form. Theno action alternative may detrimentally affect the wetland areaby natural discharge of contaminated groundwater into thewetlands. Therefore, this alternative may not comply with theWetland Protection Act. Alternatives 2, 3, and 4 includeremedial activities, i.e. excavation and/or filling in thewetland area. These activities must meet the substantiverequirements of the Wetlands Protection Act. Compliance with thesubstantive standards of the Wetland Act must be met forAlternatives 2, 3, and 4 and will require close interaction withthe appropriate regulatory agencies.

The substantive provisions of Parts 6 and 7 of the rulespromulgated under the Michigan Environmental Response Act (Act307) are considered an ARAR for the remedial action to beundertaken at this site. These rules provide, inter alia.that remedial action be protective of human health, safety andthe environment, (Rule 299.5705 (1)). The rules specify thatthis standard is achieved by a degree of cleanup which conformsto one or more of three cleanup types (Rule 299.5705(2)). A typeA cleanup generally achieves cleanup to background (Rule299.5707); a type B cleanup meets specified risk-based levels inall media (Rule 299.5709); and a type C cleanup is based on asite-specific risk assessment which considers specified criteria.The selected remedy meets this ARAR.

The Soil Erosion and Sedimentation Act establishes general soilerosion and sedimentation control procedures and measures forspecified activities which disturb one or more acres of land oris within 500 feet of a lake or stream. Because the activities

30

specified in Part 17 rules are not the activities which'directlycorrespond to the remedial alternatives, these rules are notapplicable to the alternatives for the L.o.u. However, Alterna-tives 2, 3, and 4 will disturb one or more acres of land and arewithin 500 feet of a stream. Therefore, the requirements ofthese rules are^sufficiently similar to the site that they arerelevant and appropriate. It is expected that Alternatives 2, 3,and 4 will comply with the requirements of Part 17 Soil Erosionand Sedimentation rules.

The Air Pollution Control Act was enacted to control air pollu-tion in Michigan. Part 2 Air Use Approval rules establishesrequirements for the installation or construction of equipmentwhich may be a source of an air contaminant. Alternatives 2, 3,and 4 include ozonation for the groundwater. Alternatives 3 and4 include LTTD and incineration of soil and/or sludges and berms.These treatment systems may be sources of air contaminants,therefore, Part 2 rules are applicable. Alternatives 2, 3, and 4are expected to comply with the requirements of these rules.Part 3, Emissions Limitations and Prohibitions for ParticulateMatter, establishes standards for the density of emissions andemission of particulate matter. Alternatives 2, 3, and 4 includeactivities which are sources of particulate matter, i.e.processing, using, storing, transporting and/or conveying bulkmaterials. Therefore, these rules are applicable to Alterna-tives 2, 3, and 4. It is expected that these alternatives willcomply with the requirements of these rules. Part 7, EmissionLimitations and Prohibitions for New sources of Volatile OrganicCompound Emissions provides general provisions for new sources ofvolatile organic compound emissions. Alternatives 2, 3, and 4may provide VOC emissions. Therefore, these rules are applicableto these alternatives. Tt- IK eyno^-+-^^ +•>>-»*- M *- ,---,+-,*.,,«.- -<. ->ana 4 wail comply with requirements of Part 7 rules. Part 9Emissions Limitations and Prohibitions prohibits the emission ofan air contaminant or water vapor in a quantity that causesinjurious effects to human health and the environment. From therisk assessment, the L.O.U. may provide an unacceptable risk tohuman health and the environment via the air route of exposure.Part 9 rules are applicable to the no action alternative, andthis alternative does not comply with the requirements of theserules. With appropriate emissions controls, Alternatives 2, 3,and 4 are expected to comply with these rules. Part 10, Inter-mittent and Sampling rules give the commission the authority torequire performance tests of any source of an air contaminant.Performance tests can be performed only on unit processes.

Therefore, these rules are applicable to Alternatives 2, 3, and 4which include treatment systems. It is expected that thesealternatives will comply with intermittent testing and samplingif and when the commission requires performance tests.

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3&S&&&&&&J ••Jtefei- ^ . ^ .fr .;. ;,,v'..'- .-J&

Primary Balancing Criteria

Long-Term Effectiveness and Permanence

The evaluation of alternatives under this criterion addresses therisk remaining at the site after response objectives have beenmet. The primary focus of this evaluation is the extent andeffectiveness of the controls that may be required to manage therisk posed by treatment residuals and/or untreated wastes.

Alternative 1 provides no long-term effectiveness and wouldresult in continuation of the evaluated 10~ risk levels thatexist at the Bofors site. Alternative 2 provides for insti-tutional controls and permanent extraction and treatment ofgroundwater as a means of perpetually managing the site. Thereliability of controls for this alternative for the most partdepend on the successful implementation of institutional controlson the use of groundwater as a drinking water source andcontinuation of groundwater pumping and treatment forever. Therewill likely be difficulties in implementing and maintaining theseinstitutional controls and perpetual groundwater remediation.Alternative 3 remediates the more contaminated areas of theBofors Site. Alternative 3 requires a finite groundwater extrac-tion and treatment period, but compromises the cleanup levelattained in groundwater to 10 rather than 10~ because of theuse of capping. Therefore, the residual risk of Alternative 3must be recognized as two orders of magnitude greater thanAlternatives 2 and 4. Alternative 4 is the most comprehensive ofthe alternatives relative to long-term risks. This alternativeis projected to be able to attain 10~ risk levels. Thisalternative, like Alternative 3, minimizes long-term managementbecause the purge well and treatment system will be turned offeventually. In addition, Alternative 4 uses a higher degree of

^ j,aiiai j. j. j. a. JILJ ; , tJiuii ttj. Lei i id L i ve j

Reduction of Toxicitv. Mobility, or Volume Through Treatment

This evaluation criterion addresses the statutory preference forselecting remedial actions that employ treatment technologiesthat permanently and significantly reduce toxicity, mobility, orvolume of the untreated wastes. The preference is towardtreatment processes which result in destruction of toxiccontaminants, reduction of toxic contaminants total mass,irreversible reduction in contaminant mobility, or reduction oftotal volume of contaminated media.

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All alternatives except Alternatives 1 and 2 provide, to varyingdegrees, permanent and irreversible reduction of contaminants.No significant destruction of toxic components or reduction intotal volume is achievable in Alternative 2. Alternatives 3 and 4employ both containment and treatment technologies with treatmentof the principal threat.

Alternatives 3 and 4 incluuu un-site treatment technologies(incineration and LTTD) capable of significantly and irreversiblyreducing the toxicity and volume of the untreated source wastes.The landfill component of Alternative 4 provides only permanentcontainment, not destruction or reduction in volume. However,this containment is more protective than the capping in Alterna-tive 3, because the landfill has a cap and a bottom liner system,providing a greater degree of containment.

Short-Term Effectiveness

This evaluation criterion addresses the effects of the alterna-tive during the construction and implementation phases untilremedial response objectives are attained. Under this criterion,alternatives are evaluated with respect to their effects on humanhealth and the environment.

Short-term effectiveness is not applicable to Alternative 1 sincethere is no remediation in this alternative. Alternative 2 doesnot require excavation of contaminated material and therefore hasa lower potential risk to the on-site workers and the nearbycommunity. Some grading will be required that may generate someair-borne contamination that must be controlled. Alternatives 3and 4 both require excavation of contaminated material whichcould generate air-borne contamination. Alternatives 3 anu 4also have the potential for air emissions from the incineratorand LTTD units. Air emissions controls will be implemented onthese systems as needed and these alternatives would be subjectedto community health and safety work plans for controllingfugitive dust and air emissions and potential exposures.

Considering the time required for protection and the time untilthe remedial action objectives are met, Alternative 2 requiresperpetual groundwater extraction and treatment and is essentiallya management alternative that requires the establishment of apermanent treatment facility, monitoring plan, site security,etc. In contrast. Alternatives 3 and 4 require a finite periodof time for groundwater extraction and treatment. This can bemore easily managed. Both Alternatives 3 and 4 are expected to

33

^ Wjfcpilft ^ "~

require approximately the same remediation time period of 5 years(not including the time to pump and treat groundwater).

Implementabilitv

This criterion addresses the technical and administrativefeasibility of implementing an alternative and the availabilityof various services and materials required during its implemen-tation.

Technically, all site alternatives are easily implemented andreadily constructed of available materials. The technologiesconsidered (which include incineration, LTTD, capping, andpumping and treatment of groundwater) are available fromcommercial vendors. Those alternatives which employ incinerationand LTTD simultaneously present moderate site restrictions. As aresult of space constraints, these processes must be separated,therefore construction will occur on opposite sides of the Boforssite, warranting careful coordination between these constructionphases.

Groundwater treatment systems and long-term monitoring will berequired for each remedial alternative and do not presentconstraints on implementation. However, approval of institu-tional controls placed on groundwater under Alternative 2 may bedifficult to obtain, and the long-term reliability of thesecontrols is questionable.

All remedial actions in Alternatives 2, 3, and 4 are proposed totake place on-site. Therefore, no actual permits are required;however, the substantive requirements of permits must bp met.Coordination with the local community may be required to ensurethe acceptability of incineration and LTTD in Alternatives 3 and4 and the substantive requirements of the air permit will need tobe met for air emissions from implementation of these twoalternatives.

Cost

Capital, annual O&M, and present worth costs are summarized inTable 14. Alternative 4 is the least expensive alternative ofthe alternatives that provide treatment of the contaminatedmaterial. Alternative 2 is less expensive than Alternative 4 butcontains no treatment of the principal threat and requiresperpetual pumping and treatment of the groundwater for contain-ment of the plume.

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TABLE 14ALTER IATIVE COST SUMMARY

Bofors Sitetv jskegon, Michigan

Alternative

Alternative 1

Alternative 2

Alternative 3

Alternative 4

AlternativeDescriptions

No Action.

Capping, Groundwater InstitutionalControls, Pump & Treat Ground-water Perpetually.

Capping, Incineration, LTTD, Pumpand Treat Groundwater for FinitePeriod.

Incineration, LTTD, Landfill, Pumpand Treat Groundwater for FinitePeriod.

Capital Cost

_ -_

512.091,000

574,416,000

B65.752.000

O&M Cost

$27,000

$429,000

$344,000

$313,000

Total PresentWorth Cost*

$484,000

$19.890,000

$79,912,000

$70,874,000

Risk R malningA'"er

Remt dlation

1 H

1 >-6

1 -4

1 -6

PathwaysRemediated

None

SW.A

GW, SW, A

GW, SW, A

NOTES:* i Present Worth based on perpetual pump and treat for Aliemativ* 3 2 and 4; 43 years ol pump and treat for other alternatives; vari; >le times for flushing

options depending on time to effectively reduce contaminant cot :entrations; all present worth costs are calculated using an intert ; rate 5.5%. Capand landlill options provide long-term O&M for periods equal to t e pump and treat times. 43-year groundwater pump and treat pi iod is approximate

' onty and based on preliminary evaluations. This wilt be evaluate i further in the Groundwater Operable Unit Feasibility Study.

2 The present worth analysis is used to evaluate expenditures tha occur over different lime periods by discounting all future costs \< a common baseyear. This allows the cost of remedial action alternatives to be c mpared on the basis of a single figure representing the amount > money that, ifinvested in the base year and disbursed as needed, would be si icient to cover all costs associated with the remedial alternative ;er its plannedlife.

Alternative 1 costs represent long-term monitoring.

Costs assume sludge, berms, and soils beneath the lagoons are c< ntaminated above 10-3 risk level to the water table. Soils arounc 3re assumedto be contaminated above 10-6 risk level only in the top 5 feet.

GW: Groundwater.

SW: Surface water.

A: Air.

:.•-.. J IJLJ...

Modifying Criteria -,

State Acceptance

The State of Michigan has indicated it's acceptance ofAlternative 4 for remediation of the L.O.U. at the Bofors siteand a letter of concurrence is forthcoming.

Community Acceptance

There were several comments received from the community duringthe public comment period. In summary, two who commentedperceive that there is a high level of cancer mortality in thearea and that more needs to be done to protect the community.The third expressed that money could be spent on "betterpriorities" than expanding wastewater facilities, and suggestedthe use of bacteria to "eat up" contaminants. Several commentersexpressed objections to the use of incineration. However,U.S. EPA is confident that the remedy will be protective of humanhealth and the environment. The complete comments are addressedin the attached Responsiveness Summary.

THE SELECTED REMEDY

Based upon consideration of the requirements of CERCLA, thedetailed analysis of the alternatives, and public comments, bothU.S. EPA and the State have determined that Alternative 4:Excavation, On-site Incineration/Low-Temperature Thermal Desorp-tion, On-site Disposal, and Pumping and Treatment of Groundwateris the most appropriate remedy for the Bofors site in Muskegon,Michigan.

Approximately luu,ouu <JUJJ.L<_: yaius \yu-j oi moac-conuaminateasludge will be excavated from the lagoon area. The organiccompounds in the sludge will be treated using incineration andlow-temperature thermal desorption technologies. Approximately64 percent of the organic compounds will be removed by thistreatment process. The treated sludges will be landfilled in anRCRA landfill. It is estimated that 73,100 yd3 of treated ashwill be landfilled. Approximately 334,700 yd3 of less-contami-nated sludges and soils will also be excavated and placed in theRCRA landfill. This landfill will occupy approximately 8 acresin the lagoon area.

Remediation Goals

The purpose of this response action is to control risks posed bymigration of organic compounds to groundwater and surface waterand through air. Existing conditions at the site have beendetermined to pose an excess lifetime cancer risk of 10 fromingestion of contaminated groundwater. This risk relates to theorganic compound concentrations (primarily benzidine and DCB) in

35

the sludges. Since no Federal or State chemical-specific ARARsexist for sludge and soil that specify concentrations, the actionlevel for the organic compounds in sludge and soil was determinedthrough a site-specific analysis. This analysis used fate andtransport modeling to determine levels to which organic compoundsin sludges and soils should be reduced in order to ensure nomigration of contaminants to the primary pathways of groundwater,cjn^^a^rt f-'at^r nr ^i.r above 10 levels.

The excavated contaminated sludges and berms will be treatedusing incineration and low-temperature thermal desorption whichwill remove approximately 64 percent of the organic compoundsfrom the sludge and berms. The ash from treated sludge and bermswill be excavated and landfilled in a on-site landfill that willmeet the intent of RCRA subtitle C requirements, along with theless contaminated soils beneath and around the sludge.

A breakdown of capital, annual O&M, and present-worth costs forthe selected remedy are presented in Table 15.

THE STATUTORY DETERMINATIONS

Under its legal authorities, U.S. EPA's primary responsibility atSuperfund sites is to undertake remedial actions that achieveadequate protection of human health and the environment. Inaddition, section 121 of CERCLA establishes several otherstatutory requirements and preferences. These specify that whencomplete, the selected remedial action for this site must complywith applicable or relevant and appropriate environmentalstandards established under Federal and State environmental lawsunless a statutory waiver is justified. The selected remedy alsomust be cost-effective and utilize permanent solutions nnrtdj.i~eniat.Lve i-reaciuent technologies or resource recoverytechnologies to the maximum extent practicable. Finally, thestatute includes a preference for remedies that employ treatmentthat permanently and significantly reduce the volume, toxicity,or mobility of hazardous wastes as their principal element. Thefollowing sections discuss how the selected remedy meets thesestatutory requirements.

Protection of Human Health and the Environment

The selected remedy protects human health and the environmentthrough treatment and landfilling of organic compound contami-nated sludge, and landfilling the soils in the lagoon area. Thelandfill will be constructed to meet the intent of RCRA SubtitleC landfill requirements to reduce the likelihood of contaminantmigration.

Treatment of the most contaminated sludge also will reduce therisks to less than 1 x 10~ . This level is within.the range ofacceptable exposure levels of between 10" and 10 . By land-

36

filling the contaminated soils, the risks of ingestion of ground-water contaminated from the soils will be further reduced. Theremay be short-term threats associated with the selected remedyduring excavation; however, these can be controlled. No adversecross-media impacts are expected from the remedy.

Compliance with ARARs

The selected remedy of excavation, on-site thermal treatment, andlandfilling will comply with all chemical-, action-, andlocation-specific ARARs. The ARARs are presented below.

Action-Specific ARARs:

Clean Water Act (CWA) of 1977, as amended [33 U.C.S. 1251]

40CRF122 + 40CRF125 - The National Pollutant DischargeElimination System (NPDES), which specifies the scope anddetails of the NPDES permit applications, including limita-tions, standards, and other permit conditions which areapplicable to all permits including specified categories ofNPDES permits. -Also specifies schedules of compliance andrequirements for recording and reporting monitoring results.

Act 348 of the Public Acts of 1965, as amended: Air Pollu-tion Act

Part 2 - Air Use Approval, which specifies informationrequired for a permit to install, construct, reconstruct,relocate, or alter any process, fuel burning or refuseburning equipment, or control equipment which may be a sourceof an air contaminant.

Chemical-Specific ARARs:


40CFR129 - Toxic Pollutant Effluent Standards, which estab-lishes toxic pollutant effluent standards and prohibitions ofspecific compounds for specified facilities discharging intonavigable waters. 40CFR129.104 sets the ambient watercriterion for benzidine in navigable water as 0.1 ug/1.

Public Health Service Act: Title XIV, as amended by the SafeDrinking Water Act [42 U.S.C. 300(f)] (Potential ARARs)

40CFR141 - National Primary Drinking Water Regulations, whichspecify maximum chemical contaminant levels (MCLs) of publicwater systems for inorganic and organic chemicals, maximumcontaminant level goals (MCLGs) of public water systems fororganic chemicals, and establishes national revised primarydrinking water regulations of MCLs for organic chemicals.

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TABLE 15

COST SUMMARY FOR THE SELECTED REMEDY

CAPTIAL COSTS:

Site Work

1. Site Preparation2. Soil Excavation3. Materials Transport4. Materials Processing/Size Reduction5. Site Monitoring

Treatment Component

1. On-site Incineration2. On-site LTTD3. Pumping and Treatment Systems

Containment Component

1. On-site Secure Landfill2. Indirect Capital Costs

Subtotal

Cost

S 2,090,400S 4,731,000S 2,752,400S 555,400$ 7,241,000

$15,035,100511,347,000S 1,218,200

S 6,387,600514.383.200

565,752,000

OPERATION AND MAINTENANCE COST:

1. Landfill O&M

Leachate Pump & Treat: combinedwith groundwater pump fc treat;1.2 million gallons per year

Maintenance of Cap and Leachate SystemUtilitiesEnvironmental Monitoring

Subtotal

2. Pump and Treat O£M

Subtotal

S 5,000/yrS 22,000/yrS 10,000/yrS L0,000/yr

S 47,000/yr

S266,OQO/yc

S313,000/yr

Note; Detail cost breakdowns are in Appendix F of the Feasibility Study.

RP/BFRSROD/AAl

'' **!••> ..•

Clean Air Act of 1963, as amended [42 U.S.C. 7401]

40CFR50 - National Primary and Secondary Ambient Air QualityStandards, which establish national primary and secondaryambient air quality standards. The appendices providemethods and procedures for measuring specific air pollutants.

40CFR60 - Standards of Performance for New StationarySources, which indicate applicability, sets particulatematter effluent standards, specifies monitoring requirements,and outlines test methods and procedures for incinerators.

40CFR61 - National Emission Standards for Hazardous AirPollutants, which identifies substances that have beendesignated hazardous air pollutants, and for which a FederalRegister notice has been published, and specifies prohibitedactivities, describes procedures for determining whetherconstruction or modification is involved, prescribes methodsof applying for approval, and covers manner in which start-upnotification is to be provided.

Act 245 of the Public Acts of 1929, as amended: WaterResources Commission Act

Part 4, Rule 57 - Water Quality Standards (Surface WaterQuality Standards), which establishes limits for all watersof the State for the following components: dissolved solids,pH, taste and odor producing substances, toxic substances,total phosphorous and other nutrients, and dissolved oxygen.

Act 348 of the Public Acts of 1965, as amended: Air Pollu-tion Act

Part 3 - Emission Limitations and Prohibitions - ParticulateMatter, which establishes standards for the density ofemissions and emission of particulate matter.

Act 307, Michigan Environmental Remediation Act, setsrequirements for remediation of hazardous waste sites inMichigan. There are three types of remediation specified bythis act; Type A, B, and C.

Location-Specific ARARs:


33CFR322 - Permits for Structures or Work in or AffectingNavigable Waters of the United States, which provide proce-dures for the C.O.E. for reviewing permits to authorizestructures or work affecting navigable water, includingwetland areas.

38

Floodplain Management, and 11990, Protection of Wetlands [42U.S.C. 7401]

40CFR6 - Procedures for Implementing Requirements of theCouncil on Environmental Quality on the National Environ-mental Policy Act, which provide policies and procedures forfloodplain management and wetland protection.

Act 203 of the Public Acts of 1979: The Goemaere-AndersonWetland Protection Act - These rules apply to activities thatresult in discharge to the wetland area that drains to theBig Black Creek. These rules include permitting require-ments, wetland determination, and mitigation.

Act 347 of the Public Acts of 1972: Soil Erosion andSedimentation Control Act

Part 17 - Soil Erosion and Sedimentation Control - Estab-lishes general soil erosion and sedimentation controlprocedures and measures. Also, specifies earth changerequirements and soil conservation district standards andspecifications.

Other Criteria. Advisories or Guidance to be Considered(TBCs):

None.

Cost-Effectiveness

The selected remedy is cost-effective because it has beendetermined to provide overall errectiveness proportional to itscosts, the net present worth value being $70,000,000. Theestimated costs of the selected remedy are within an order ofmagnitude of the costs associated with treatment of sludge andon-site capping of the contaminated soils, and yet the selectedremedy assures a lower residual risk after remediation iscomplete and higher degree of certainty that the remedy will beeffective in the long-term since more complete containment (land-filling) is used.

Utilization of Permanent Solutions and Alternative TreatmentTechnologies for Resource Recovery Technologies) to the MaximumExtent Practicable

U.S. EPA and the State of Michigan have determined that theselected remedy represents the maximum extent to which permanentsolutions and treatment technologies can be utilized in a cost-effective manner for the lagoon area operable unit at the Boforssite. Of those alternatives that are protective of human health

39

and the environment and comply with ARARs, U.S. EPA and the Statehave determined that this selected remedy provides the bestbalance of tradeoffs in terms of long-term effectiveness andpermanence, reduction in toxicity, mobility, or volume achievedthrough treatment, short-term effectiveness, implementability,cost, also considering the statutory preference for treatment asa principal element and considering State and community accep-tance.

The selected remedy offers a high degree of long-term effective-ness and permanence since incineration is being used.

The selected remedy treats the principal threats posed by thesludges, achieving significant organic compound reductions(60 percent). The implementability of the selected remedy iscomparable to the nontreatment alternatives. The selected remedyis also the least costly of the two alternatives.

The selection of treatment of the contaminated sludges is consis-tent with program expectations that indicate that highly toxicand mobile waste are a priority for treatment and often necessaryto ensure the long-term effectiveness of a remedy. Since theselected remedy has the most complete containment, this remedy isanticipated to have the best long-term effectiveness andpermanence and is therefore determined to be the most appropriatesolution for the contaminated sludges and soils at the Boforssite.

Preference for Treatment as a Principal Element

By treating the contaminated sludges in a thermal destructionunit and landfilling the ash and contaminated soils, the selectedreiueuy audresses one 01 the piMucipai bureaus posed by the sitethrough the use of treatment technologies. Therefore, thestatutory preference for remedies that employ treatment as aprincipal element is satisfied.

40

RESPONSIVENESS SUMMARY

The Remedial Investigation/Feasibility Study (RI/FS) and theProposed Plan for the Bofors-Nobel site were made available tothe public in July, 1990. The notice of availability for thesetwo documents was published in the Muskeaon Press on July 23,1990. A public comment period was held from July 23 throughAugust 23 and a public meeting was held on August 1, 1990. Atthis meeting, representatives from U.S.EPA and the MichiganDepartment of Natural Resources (MDNR) answered questions aboutproblems at the site and the remedial alternatives underconsideration. Three comments were submitted at the publicmeeting and several comments were received in the mail prior toAugust 23, 1990, the last day of the public comment period.Following are all the comments received and U.S. EPA's responseto each comment.

CommentThe first comment related to contamination in the air from thechemical company and the fact that several people in thecommunity have died of cancer.

ResponseThere are several chemical companies and several Superfund sitesin the area and the Michigan Department of Public Health ispursuing this issue.

CommentThe second commentor felt the proposed alternative is notprotective enough, particularly concerning air exposure duringremediation. She indicated more should be done.

ResponseU.S. EPA is very sensitive to the concerns of the public andbelieves the selected remedy is the most protective and willalleviate any air emissions from the lagoon site as part of theremedy. Because of the highly toxic nature of the material onsite, the alternative uses incineration to destroy the mosthazardous waste. State of the Art technology will be used toeliminate hazardous air emissions. Extensive air monitoring willbe performed to ensure control of air emissions duringconstruction.

CommentThe third commenter questioned if bacteria could be used to eatup the contamination and suggested bioremediation was notselected due to costs.

41

- ffWW

-i.

Response - fIn fact, biological treatment methods were considered andscreened out early because they will not work efficiently andare not cost effective. 3,3'-Dichlorobenzidine (DCB), which isone of the major contaminants at the site, is present at the sitein a crystalline form. DCB requires the transfer from acrystalline form into an aqueous matrix which would require asoil washing pretreatment step. Soil washing treatabilitystudies have indicated that this technology cannot adequatelyremove DCB from soil. In addition, heavy metals such as zinc,chromium, and lead which are present at the site, can be toxic tothe microorganisms and additional treatment would probably beneeded for metal contamination. In both cases the concentrationsof contaminants are very high and the waste would be verydifficult to bioremediate.

CommentSeveral commentors objected to incineration based on informationprovided by the West Michigan Region Environmental networkconcerning uncertainties, hazards and health risks associatedwith incineration.

ResponseAs previously mentioned, U.S. EPA is very sensitive to theconcerns of the community. The agency believes the selectedremedy provides the best protection the U.S. EPA can provide.Contrary to the information the citizens were given; incinerationwill destroy the hazardous compounds and the incinerator will beoperated in such way to insure total destruction. Extensivetesting prior to start-up including treatability studies andtrial burns will be performed to determine the correct operatingprocedures for the incinerator. This extensive testing isdesigned to overcome the uncertainties involved in treatment ofhazardous waste. Extensive monitoring including air emissionsand other operating parameters will be performed to evaluateincinerator performance and corrections will be made asnecessary.

CommentSeveral commentors expressed concern over the fact thegroundwater will not be addressed until much later.

ResponseIn fact, the contaminated groundwater is currently beingcontrolled by a pump and treat system which will be upgradedduring this remedy. In addition, the groundwater RemedialInvestigation/Feasibility Study (RI/FS) is currently underway.

CommentA few citizens were concerned that the pollutants will drift intopopulated areas, especially the Carr Elementary School.

42

ResponseThe response to the comment regarding objection to incinerationapplies to this comment.

CommentOne conunentor stated that all landfills leak and does not wantthe material landfilled on site. This commentor suggested weexcavate and transport the hazardous material to an offsite(emphasis added) landfill.

ResponseBecause it is known that landfills may leak, the U.S. EPA hasselected technology that provides the most protective type oflandfill. The landfill design that will be used in this remedywill consist of a double lined containment system with a leachatecollection system between the two liners to prevent migration ofany leachate that might be generated. In addition the landfillcap will be constructed to prevent infiltration of anyprecipitation so that leachate generation is minimized.Furthermore, there will be a detection system below the bottomliner to provide backup monitoring for the system. In addition,the majority of contamination will be destroyed through theincinerator and the less contaminated material will belandfilled.

The Comprehensive Environmental Response, Compensation, andLiability Act of 1980 (CERCLA) as amended by the SuperfundAmendments and Reauthorization Act of 1986 (SARA) states insection 121(b)(l) that remedial actions in which treatment whichpermanently and significantly reduces the volume, toxicity ormobility of the hazardous substances, pollutants, andcontain 1 nant-.s. are to h*» preferred over rptnpdial arMr>n«s nn-tinvolving such treatment. The offsite transport and disposal ofhazardous substances or contaminated materials without suchtreatment should be the least favored alternative remedial actionwhere practicable treatment technologies are available. U.S. EPAdoes not recommend offsite landfilling of the hazardous materialbecause it would not comply with the law.

CommentOne person indicated it is a disgrace that the ResponsibleParties wriggle out of cleaning up the site.

ResponseIt has not been established that liable parties exist for thissite. U.S. EPA will continue to explore the possibility ofnaming potentially Responsible Parties in the future.

CommentSeveral commentors requested an extension on the second to thelast day of the comment period.

43

ResponseThe National Contingency Plan (NCP) allows for a 30 day extensionto a public comment period if requested in a timely manner. TheNCP defines a "timely" request as generally being within 2 weeksafter the initiation of the public comment period. U.S. EPA doesnot believe a delay in this project will benefit the community.The protection of public health and the environment will betterbe served by moving ahead with the design and clean-up of thissite.

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