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United States EnvironmentalProtection Agency

Public Comment

FEASIBILITY STUDY REPORT

ELECTRO-VOICE INC. SITEBuchanan, Michigan

WA 37-5PE8 / Contract No. 68-W8-0040

September 10, 1991

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CKMHIll

Public Comment

FEASIBILITY STUDY REPORT

ELECTRO-VOICE INC. SITEBuchanan, Michigan

WA 37-5PE8 / Contract No. 68-W8-0040

September 10, 1991

GLT181/020.51

CONTENTS

SECTION Page

1 Introduction ] -1Purpose and Scope of Report 1-1Organization of Report 1-1

2 Site Description 2-1Site Characteristics 2-1Nature and Extent of Contamination 2-5Contaminant Fate and Transport 2-9Baseline Risk Assessment 2-9

3 Remedial Action Objectives and Goals 3-1NCP and CERCLA Requirements 3-1Site-Specific Exposure Pathways 3-2Potential ARARs 3-3Site-Specific Remedial Action Objectives and Goals 3-6

4 Remedial Technology Development and Screening 4-1General Response Actions 4-2Preliminary Technology Screening 4-2Secondary Technology Screening Criteria 4-2Secondary Technology Screening for Soil 4-3Secondary Technology Screening for Groundwater 4-10Summary 4-13

5 Development of Detailed Alternatives 5-1Descriptions of Alternatives 5-2

6 Detailed Analysis of Selected Alternatives 6-1Evaluation Criteria 6-1Individual Analysis of Alternatives 6-2

Appendix A. Screening of ARARsAppendix B. Equations Used in Extraction Well CalculationsAppendix C. Remedial Action Alternative Cost EstimatesAppendix D. Potential Chemical-Specific Remedial Action Goals

FollowsTABLES Page

2-1 Summary of Estimated Excess Lifetime Cancer Risks UnderCurrent Land Use Conditions 2-10

2-2 Summary of Estimated Excess Lifetime Cancer Risks AssumingFuture Residential Use of the Site 2-10

FollowsTABLES (Continued) Page

2-3 Summary of Estimated Noncarcinogenic Hazard Indexes UnderCurrent Land Use Conditions 2-10

2-4 Summary of Estimated Noncarcinogenic Hazard Indexes AssumingFuture Residential Use of the Site 2-10

2-5 MC/ECL Ratios for Aquatic Species 2-13

4-1 Remedial Objectives Addressed by General Response Actions 4-24-2 Technologies and Process Options Retained for Inclusion

in Remedial Alternatives 4-13

5-1 Alternatives Summary 5-1

FollowsFIGURES Page

1-1 Feasibility Study Process 1-1

2-1 Location Map 2-12-2 Study Area 2-12-3 Site Map 2-12-4 Groundwater Contour Map with VOC Plume 2-12-5 Soil Boring Location Map 2-52-6 100-Year Flood Plain 2-8

3-1 Sludge, VOC, and SVOC Contaminated Areas and GeologicalCross Section Location Map 3-7

3-2 Fuel Tank/Dry Well Area Cross Section AA-AA'—Sludge, VOC,and SVOC Contaminated Areas 3-7

3-3 Dry Well Area Cross Section BB-BB'—Sludge, VOC, and SVOCContaminated Areas 3-7

3-4 Former Lagoon/Dry Well Area Cross Section CC-CC'—Sludge,VOC, SVOC, and PCB Contaminated Soil Areas 3-7

3-5 Groundwater Contour Map with VOC Plume 3-8

4-1 Initial Screening of Process Options for Soil Remediation 4-24-2 Initial Screening of Process Options for Groundwater Remediation 4-2

5-1 Alternatives Development Matrix 5-15-2 Alternative 2 5-35-3 Conceptual SVE System 5-45-4 Alternative 3A 5-55-5 Alternative 4A—Groundwater Treatment Schematic 5-55-6 Alternative 4A 5-55-7 Alternative 5A 5-65-8 Alternative 5B 5-6

GLT181/023.51

Section 1INTRODUCTION

PURPOSE AND SCOPE OF REPORT

This report presents the results of a feasibility study (FS) performed for theElectro-Voice, Inc. (EV) site, located at 600 Cecil Street in the City of Buchanan,Berrien County, Michigan. The FS work originally commenced in accordance with anAdministrative Order by Consent entered into between the U.S. EnvironmentalProtection Agency (EPA) and EV on October 15, 1987. Fishbeck, Thompson, Carr& Huber, Inc., completed the original FS for EV in January 1991.

The U.S. EPA also assigned CH2M HILL to perform an FS of the site. This revisedFS report was prepared using data provided in deliverables submitted to theU.S. EPA by EV. The checking or verification of data or assumptions used by EV inthe generation of the RI, which is the basis for this revised FS report, was not part ofthe scope for the preparation of the FS. CH2M HILL used the information providedin the EV deliverables to reevaluate risks, ARARs, and remedial alternatives for theElectro-Voice site. CH2M HILL assumed that all the data and information suppliedin the EV deliverables and used in the revised FS had been accepted by theU.S. EPA as usable. The accuracy of the FS is dependent upon the accuracy of thedata provided by EV.

The purpose of the FS is to provide information to assist in the selection of acost-effective remedial action alternative (RAA) in accordance with theComprehensive Environmental Response, Compensation and Liability Act(CERCLA) and the National Oil and Hazardous Substances Contingency Plan (NCP).The FS will serve as the basis for documentation of the selected remedy in the EPA'srecord of decision (ROD) and for remedial design (RD).

ORGANIZATION OF REPORT

The FS process (summarized in Figure 1-1, following page 1-1) began with theidentification of the site areas of concern (response units) and the remedial actionobjectives (RAOs) for these areas. The response units and RAOs were determinedbased on data and conclusions developed during the RI and the risk assessment.

The RI work is summarized in the report entitled Final Remedial Investigation Reportfor Electro-Voice, Inc. (EV 1990). The RI characterizes existing site conditionsincluding physical characteristics, site history, and the nature and extent ofcontamination. The results of the RI are summarized in Section 2 of this FS report.The risk assessment, which was performed by Ecology and Environment, Inc., issummarized in the report entitled Risk Assessment for the Electro-Voice Site. Theassessment, also summarized in Section 2, examined the potential threat posed by thesite to human health and the environment and calculated risk levels based onestablished U.S. EPA guidelines.

1-1

Section 1INTRODUCTION

Section 2SITE BACKGROUND

Section 3REMEDIAL ACTION

GOALS AND OBJECTIVES

Appendix ASITE ARARs

Section 4REMEDIAL TECHNOLOGY

DEVELOPMENT SCREENING

Section 5REMEDIAL ALTERNATIVE

DEVELOPMENT IAppendix B

CONTAMINANTMIGRATION ESTIMATES

Section 6EVALUATION OFALTERNATIVES

Appendix CCOST ESTIMATE

Figure 1-1Feasibility Study Process

Electro-Voice, Inc. FS

The risk assessment and ARARs were used in Section 3 to develop RAOs. After theRAOs were identified, information regarding potentially applicable technologies wasdeveloped. The process consisted of: (1) identification of applicable technologiesand process options and (2) screening of technologies and process options that wouldnot meet response objectives or that are technically infeasible because of specific sitecharacteristics, waste characteristics, or other physical constraints. This screening stepeliminated infeasible or unacceptable technologies from further consideration.

In the secondary evaluation of technologies, the technology processes considered tobe implementable were evaluated in greater detail before selecting one process torepresent each technology type. This was done to simplify the subsequentdevelopment and evaluation of alternatives without limiting flexibility during the RD.The process options within each technology type were compared on the basis ofrelative effectiveness, implementability, and cost, as documented in Section 4.

Upon completion of the screening and evaluation processes, the remaining technologyoptions identified as implementable and relatively cost-effective were then combinedto form a range of remedial action alternatives in accordance with the NCP. A no-action alternative was retained for comparison of baseline risk to human health andthe environment.

The alternatives that were developed are described in detail in Section 5. Finally, theassembled alternatives were evaluated, as described in Section 6.

GLT181/001.51

1-2

Section 2SITE DESCRIPTION

SITE CHARACTERISTICSSTUDY REGION

The study region is about 6 miles west of Niles in the City of Buchanan, BerrienCounty, Michigan, in the NW quarter of Section 36, Township 7 N, Range 18 W. Itincludes the study area and study site (see Figure 2-1, following page 2-1).

The study area is the area in which the RI field work was conducted. It includes theEV site and the area extending from the site to just north of McCoy Creek (seeFigure 2-2, following page 2-1). The study area is approximately 160 acres or0.25 square mile. The study site consists of about 11.5 acres of land currently ownedby EV (see Figure 2-3, following page 2-1). The EV site is located at 600 Cecil Streetin Buchanan, Michigan.

PHYSIOGRAPHY

The EV site is in the southern portion of the City of Buchanan, a commercial andresidential community of about 5,000. The City of Buchanan encompasses the studyarea and lies in the southern portion of the St. Joseph River drainage basin.

The land surface elevation in the study area varies considerably as a result ofglaciation and subsequent dissection of the glacial drift by the St. Joseph River and itstributaries. The elevation of the eastern portion of the EV site is approximately740 feet above mean sea level. The land surface of the western portion of the siterepresents a natural land surface depression with an elevation of about 715 feet.Ground surface elevation decreases gradually toward McCoy Creek to the northwest.McCoy Creek decreases in elevation from approximately 680 to 665 feet across thestudy area. McCoy Creek flows to the northeast and discharges to the St. JosephRiver approximately 1 mile downstream of the study area.

HYDROGEOLOGY

The study area geology consists of glacial drift deposits underlain by bedrock of theAntrim Shale formation. The glacial drift consists of two primary units: an outwash(sand and gravel) unit underlain by a clay-rich till unit. The lower portion of theoutwash unit is an extensive unconfined aquifer. The aquifer ranges in thickness fromabout 50 feet at the EV site to 10 feet near McCoy Creek. Driller's logs indicate thata lower confined aquifer also exists within the drift in localized areas and is separatedfrom the upper aquifer by the clay-rich confining layer. However, a lower aquifer wasnot identified in the study area. All investigative borings that completely penetratedthe aquifer encountered a clay-rich confining layer. The upper unconfined aquifer isconsidered the aquifer of concern since all identified contaminants in the groundwateroriginating from the EV site have been shown to exist predominantly in theunconfined aquifer. Contaminants were detected near the base of the unconfinedaquifer at MW-18D (4 /ig/L TCE) and at higher concentrations at MW-26D (5 /ig/Lcis-l,2-dichloroethene [DCE], 60/tg/L TCE) (see Figure 2-4, following page 2-1, for

2-1

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STUDY REGION

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SOURCE: Figure 1-2. Boctro-Voice FS,FTC&M Engineers & Scientists. 1-90.

Figure 2-1Location Map

Electro-Voice. Inc. FS

FOURTH ST.

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^—. —— Approximate Sit*Property Boundaries

Figure 2-2Study Area

Electro-Voice, Inc. FS

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FORMERLAGOONS

OWWOi. ST.

SITE MAP

SOURCE: Figure 1-4. Electro-Voice FS,FTC&H Engineers & Scientists. 1-90.

Figure 2-3Site Map

Electro-Voice. Inc. FS

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5 S V /

MONITOR WE.U AND682 60 GROUNDVMTER £LEV

——— - —— APPROXIMATE SITEPROPERTY BOUNDARIES

• Mr~n McCO" OREEK t»CC ADO679 69 S1*£A*I ELEVATION

GROUNOWATER.^——680-^ ELEVATION CONTOUR—— — — — — — GROUNDWATER FLOW PATH

: ' «°PRO»IMATE VOC ~BOUHO4P»

SOURCE: Figure 1-6. Electro-Voice FS,FTC&H Engineers & Scientists, 1-90.

Figure 2-4Groundwater Contour Map

With VOC PlumeElectro-Voice, Inc. FS

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monitoring well locations). The aquifer is approximately 10 feet thick at MW-26D.The proximity of MW-26D to McCoy Creek and observed water levels indicate thatgroundwater discharges to the creek.

The groundwater is approximately 50 feet below ground at the eastern portion of thesite, 30 feet in the former lagoon area, 60 feet in the center of the study area, andless than 10 feet below ground near McCoy Creek. Groundwater flow direction isnortherly toward McCoy Creek. The horizontal hydraulic head gradient ranges from0.0025 ft/ft in the center of the study area to about 0.010 ft/ft near McCoy Creek.There is a downward hydraulic head gradient in the central (0.0097 ft/ft) and northern(0.0021 ft/ft) portions of the study area, but there is no apparent vertical hydraulichead gradient at the EV site.

The relatively coarse sand and gravel aquifer is characterized by an average porosityof 0.20 and an average hydraulic conductivity of 1.24 x 10"3 feet per second. Theaverage linear groundwater flow velocity within the upper aquifer in the study area isestimated at 860 feet per year. Groundwater is discharged to McCoy Creek from theupper aquifer, as indicated by groundwater flow direction measurements and flowmeasurements of McCoy Creek.

NEARBY POPULATION AND LAND USE

The EV property and nearby surrounding areas are illustrated in Figures 2-1 and 2-2,following page 2-1. The population of the study region is concentrated primarily inthe City of Buchanan, located north of the EV site. According to U.S. census figures,the population was 4,645 in 1970 and 5,142 in 1980. The population of BuchananTownship increased from 3,182 in 1970 to 3,571 in 1980.

The north and west sides of the EV property border on residential areas of the Cityof Buchanan. Additional residences are located south of the property, beyond theadjacent railroad right-of-way. The east side of the property borders on baseballdiamonds, tennis courts, and playground areas belonging to Stark Elementary School.The school building itself is north of the playground and northeast of the EVproperty. As of March 1990, 319 students were enrolled at Stark Elementary School

. in kindergarten through the fifth grade. The closest residences to the north, south,I and west and the playing fields to the east are 350 to 500 feet from the former dry

well and lagoon areas. The number of EV employees at the Cecil Street facility int April 1990 was about 150.

' Groundwater beneath the EV site flows under residential and commercial areas northof the site to McCoy Creek. The section of McCoy Creek where the plume is

j believed to discharge is bordered on the south by the former Clark Equipment> Company and on the north by F. S. Carbon Company properties, the City of

Buchanan City Building, and Woodstock Manufacturing Company properties.

j CLIMATOLOGY

[ Monthly normals for temperature and precipitation have been recorded at Bentonj Harbor and Eau Claire for the period 1948 to 1977. Data recorded at the Eau Claire

Station were used in this report because of its proximity (11 miles northeast) to theI City of Buchanan. The average daily maximum, minimum, and average temperaturesi, 2-2

for the region were measured at 58.8°, 40.4°, and 49.6°F, respectively. The warmestdays of the year occur in July (average is 72.8°F), the coldest in February (average is24.1°F).

The normal annual precipitation in the study region is 35.38 inches. The maximummean monthly precipitation (3.80 inches) occurs in April, and the minimum meanmonthly precipitation (1.79 inches) occurs in February. The average annual snowfallfor the region is 65 inches. The prevailing winds of the region are from thesouth-southwest.

Climatological data recorded at South Bend, Indiana, indicate similar temperaturefigures, an average annual precipitation of 38 inches, and an average annual snowfallof 72 inches. The average wind speed is 10.3 miles per hour. The prevailing winddirection is from the southwest or south-southwest from May through February,shifting to the north-northwest for March and April, according to data from the SouthBend station.

SITE HISTORY AND DESCRIPTION

The original building at the EV site was constructed in about 1902. Activitiesconducted at the site from 1902 into the 1920s are not well documented. CampbellTransmissions Company used the facility in the late 1920s and early 1930s. Theproperty and facility were subsequently purchased by the Dry Zero Corporation,which produced insulating materials and operated from the mid-1930s to 1940. ClarkEquipment Company, which manufactured transmissions for large equipment, leasedand used the facility from 1940 to 1946. EV purchased the property and beganoperation in 1946. Activities conducted by EV at the facility include administration,assembly, die casting, machining, painting, and electroplating associated with themanufacturing of audio equipment.

The EV site occupies about 11.5 acres. Expansion of the facility since acquisition byEV has included the addition of a front office, warehouse, machine shop, and variousother additions. Fill material was used to raise the ground surface elevation of thewestern portion of the site. The fill materials reportedly consisted of residentialrefuse, trash, and demolition debris from several razed buildings in the City ofBuchanan. The materials were dumped on the site periodically from the 1920s to theearly 1950s.

In 1952, EV constructed two bentonite-clay-lined lagoons (north and south) fordisposal of liquid waste from the electroplating operation at the plant. The lagoons(Figure 2-3, following page 2-1) were located west of the plant and were connected inseries by an overflow pipe. EV discharged metal plating waste to the north lagoonfrom 1952 to 1962. Plant personnel indicate that no metal plating waste wasdischarged to the south lagoon, but area residents indicate that both lagoons receivedplating waste. Use of these lagoons was discontinued in 1962 after a new wastewatertreatment facility was installed at the site.

In January 1980, four monitoring wells were installed around the lagoons as part of astudy by TenEch Environmental Consultants, Inc. (South Bend, Indiana) for removaland abandonment of the two lagoons (Figure 2-3, following page 2-1). Periodicgroundwater sampling of the four wells began in January 1980. Analysis of

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groundwater samples collected from the four wells in January 1980 revealeddetectable concentrations of xylene and toluene in two of the wells. Concentrationsof lead were also detected in groundwater collected from all four wells.

In September 1980, pursuant to a remediation plan approved by the MichiganDepartment of Natural Resources (MDNR), the north lagoon and its contents wereremoved. The materials removed—9,500 gallons of water, 19,600 gallons of sludge,and 40 cubic yards of clay liner—were disposed of offsite, and the area was thenfilled with imported fill. The south lagoon was not considered to be contaminatedand was not excavated; it was filled with imported fill and graded to the naturalsurface topography of the area. During grading operations, contaminated soilsappeared to have been spread throughout the lagoon area. Lagoon closure activitywas performed in accordance with Michigan Act 64 (Hazardous Waste ManagementAct) and its proposed Administrative Rules (1979). All waste was listed on industrialwaste disposal manifest forms and approved for transportation and disposal by theMDNR.

With the installation of a new automated painting system in 1964, a dry well wasinstalled at the location indicated in Figure 2-3, following page 2-1. The dry wellconsisted of an excavated pit backfilled with gravel. A drain pipe connected a sinkinside the building to the dry well. The dry well reportedly was used to dispose ofliquid waste from the paint shop that included toluene and xylene derivatives as wellas methyl ethyl ketone (MEK or 2-butanone). The dry well was in use from 1964 to1973, after which a subsurface tank was installed immediately to the west to collectdischarge from the paint shop. In 1975, the subsurface tank was,removed and

!replaced with a long, upright, buried tank of similar capacity. The second tank wasremoved in about 1983. An aboveground tank with a capacity of 1,000 gallons,identified as the MEK tank, was placed about 25 feet south of the dry well. TheMEK tank also was removed from the site.

Two partially buried fuel oil tanks were excavated and removed from the site in July1987. These tanks, which were located outside the maintenance shop doorway asindicated in Figure 2-3, following page 2-1, had been onsite since 1930. EV used thetanks from 1946 to 1960 for storage of No. 6 fuel oil. Analytical results of soilsampling conducted during the excavation and removal of the tanks indicated lowconcentrations of trichloroethene (TCE), tetrachloroethene (PCE), DCE, and1,1,1-trichloroethane (TCA). An unspecified volume of soils in this area wasexcavated and replaced with clean fill during removal of the fuel oil tanks.

Ecology and Environment, Inc., conducted a Hazard Ranking System Assessment atthe EV site on July 29, 1982. In February 1983, the EV site was placed on theNational Priority List (NPL) and the Michigan Act 307 Priority List. In the June 1986National Priority List Fact Book, the EV site was ranked No. 491, Group 10. In theFebruary 1987 Michigan Sites of Environmental Contamination Priority List (Act 307)Book, the site received a score of 610, Group 1.

2-4

NATURE AND EXTENT OF CONTAMINATION

POTENTIAL SOURCES OF CONTAMINATION

Three potential onsite source areas at the EV site—the dry well, the former fuel tankarea, and the former lagoon area—were investigated to determine the presence andextent of any contamination. Investigation of the source areas included fieldscreening of soils for volatile organic compounds (VOCs) at select boring intervalsusing a gas chromatograph. Selected samples were chosen for laboratory analysisprimarily on the basis of field screening results.

SOIL CHEMICAL QUALITY

Background Soil Chemical Quality

One boring (B) was completed along the tree line west of the south lagoon area (asshown in Figure 2-5, following page 2-5) to approximate background soil chemicalquality conditions. Samples B6I (13.5 to 16 feet deep) and B8I (18.5 to 21 feet deep)were submitted for laboratory analysis based primarily on field screening results.

Analytical results for background soil samples indicated two tentatively identifiedsemivolatile compounds (TICs) at a depth of 13.5 to 16 feet. No target VOCs,polychlorinated biphenyls (PCBs), or pesticide compounds were detected inbackground soils.

At the direction of the U.S. EPA and the MDNR (August 1990), the mean ofconcentrations from the two background samples (B6I and B8I) was established asthe background level for purposes of completing the RI and risk assessment reports.The absence of more complete background soil quality data is identified as a datagap. If background data are required for use during implementation of a remedialaction, a statistically valid characterization of background quality will be developed.

Chemical Characteristics—Dry Well Area

Soil samples were collected from nine borings completed in the dry well area (seeFigure 2-5, following page 2-5). Laboratory analytical results from select samplesindicated the presence of 14 Target Compound List (TCL) VOCs, 26 TCLsemivolatile organic compounds (SVOCs), several TICs, one pesticide compound,PCBs and 14 TCL metals at concentrations above background levels. Most of thecompounds are concentrated in a sludge-like material at depths ranging from 5 to10 feet deep. The volume of the sludge-like material is estimated to be 2,100 cubicyards.

Dispersion of organic compounds in the vadose zone increases with depth. Testresults indicated that considerable vertical migration of compounds has occurred inthe vadose zone. The presence of a clay-rich horizon at a depth of 14 feet appears tolimit downward migration of metals, since only arsenic, calcium, and magnesium weredetected above background levels in lower horizon soils. The volume ofcontaminated soil is estimated to be 3,000 cubic yards.

2-5

•ICD

0 50

•••=SCALE IN FEET

ELECTRO-VOICE

FORMERNORTHLAGOON

FORMERSOUTHLAGOON

ORMERRY WELL

AREA

ELECTRO-VOICE

BACKGROUNDLOCATION

/ / FORMER -• FUEL TANK

AREA

GroundwaterMonitoring Well

Soil Bonng

•IAI Lysimeter / Soil Boring

SOURCE: Figure 1-5, Electro-Voice FS,FTC&H Engineers & Scientists, 1-90. Figure 2-5

Soil BoringLocation Map

Electro-Voice, Inc. FS

Some target organic compounds are reaching the groundwater and are migrating asdissolved constituents with the groundwater.

Chemical Characteristics—Former Lagoon Area

Soil samples were collected from two borings at each of the former lagoons duringthe RI (see Figure 2-5, following page 2-5). From each boring, one sample wascollected near the base and a second at a depth considerably below the base of theformer lagoons. Four surface soil samples were collected in March 1991 near thelysimeters in the north and south lagoons and analyzed only for arsenic, lead, andcadmium.

Analytical results for TCL organic analysis from samples collected near the base ofthe north lagoon collectively revealed the presence of 5 VOCs, 10 SVOCs, and2 TICs. Analytical results from lower horizon samples collected from the northlagoon revealed the presence of DCE and TCE but no SVOCs. No pesticides,herbicides, or PCB compounds were detected in north lagoon area soil samples.Analytical results of TCL inorganic analysis on north lagoon soils revealed thepresence of 14 metals at concentrations above background levels (defined as themean of two background soil samples). These concentrations typically appear todecrease with depth. The surface soil samples from the north lagoon had elevatedlevels of arsenic, lead, and cadmium.

Results of TCL organic analysis performed on samples collected near the base of thesouth lagoon did not reveal the presence of VOCs, but 10 SVOCs and several TICswere detected. Several TICs were found in the lower horizon soil samples, but VOCsand SVOCs were not. No pesticides, herbicides, or PCB compounds were detected insoil samples from the south lagoon area. Results of TCL inorganic analysis revealedthe presence of 17 metals at concentrations above background levels (defined as themean of two background samples). These concentrations appear to decrease withdepth. The surface soil samples from the south lagoon had elevated levels of arsenic,lead, and cadmium.

Chemical Characteristics—Former Fuel Tank Area

Soil samples were collected from two borings in the former fuel tank area (as shownin Figure 2-5, following page 2-5) and analyzed for VOCs. Laboratory analyticalresults indicated the presence of two VOCs—PCE (1 /Ag/kg) and TCE (25 Aig/kg).These compounds were detected in one sample collected near the base of the formertanks. No VOCs were detected in the second sample, collected at a depthconsiderably below the former tanks. Analytical results on a groundwater samplefrom MW-12, immediately downgradient from the former fuel tank area, revealed thepresence of TCE at 1 /xg/L.

VADOSE-ZONE WATER QUALITY

Vadose-zone water, sampled from three lysimeters located in the former lagoon area,was analyzed for TCL metals and general water quality indicator parameters.Samples from the two south lagoon lysimeters (LY-1 and LY-2) collectively revealedthe presence of cadmium, nickel, and zinc at concentrations above detection limit. Asample collected from the north lagoon lysimeter (LY-3) revealed the presence of

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cadmium, chromium, nickel, and zinc at concentrations above detection limit.Background vadose-zone water quality was not determined during the RI.

GROUNDWATER QUALITY

During Phase I of the RI, 7 monitoring wells and were installed and 11 monitoringwells (including 4 existing wells) were sampled. Phase II activity included theinstallation of 27 monitoring wells and the sampling of all monitoring wells. Theresults of both phases of the investigation indicated that VOCs were present in the

i onsite groundwater.

Groundwater from monitoring well MW-2 had the highest detected concentrations of! organic analytes. Most of the VOCs detected in MW-2, however, were not detected.' in downgradient wells. Three chlorinated VOCs (DCE, TCE and vinyl chloride) have

been detected in downgradient wells. Processes such as volatilization to the vadosei zone, sorption to soils, degradation, and dilution may be contributing to the

attenuation seen in the downgradient wells.

The horizontal extent of the VOC-contaminated groundwater is indicated in| Figure 2-4, following page 2-1. The groundwater plume extends from the EV site to

McCoy Creek (a distance of approximately 3,000 feet with a maximum width of. approximately 600 feet) and consists of low levels of DCE and TCE and traces ofJ vinyl chloride. RI data indicate that the vertical extent of the contamination is1 primarily limited to the upper 15 feet of the aquifer.

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The groundwater samples were analyzed for TCL SVOCs during the Phase I samplingand did not indicate significant levels of these compounds at any monitoring wellsexcept MW-2, which is located immediately downgradient of the former dry well area.

Analysis for TCL inorganic parameters indicated that metals are not present abovebackground levels at any of the well locations with the exception of MW-17, wherechromium (18.8 /*g/L) and nickel (52.3 /ig/L) were detected at concentrations abovepractical quantitation limits.

v Analytical results of groundwater indicator and field parameters may indicate thatJ some contaminants could potentially be migrating onto the site from an upgradient* source. Elevated levels of ammonia, total dissolved solids, total Kjeldahl nitrogen,

total organic carbon, specific conductance, and a low Eh value were detected atI MW-6. Several other upgradient and downgradient wells exhibited similar' concentrations of these parameters.

I A lower aquifer was not identified in the study area. All soil borings that havecompletely penetrated the upper aquifer have encountered a dense clay-rich tillconfining layer. If a lower aquifer exists in the study area, it may be protected by this

j clay-rich barrier layer. Field screening and laboratory results of groundwater samplesI from the base of the upper aquifer indicate that VOCs were not present at the base

of the upper aquifer. However, the U.S. EPA has recognized that a lower aquifer (ifi one exists) has not been sampled and analyzed, and that therefore a data gap exists.j To address the data gap, a boring should be completed near MW-9S that would

extend into the second aquifer (if it exists) or into 10 feet of the base clay till layer,whichever comes first. A sample of either clay or groundwater (by means of installing

2-7

a monitoring well) from the lower aquifer would be analyzed for Contract LaboratoryProgram (CLP) volatile organics. This work would be completed during the RDphase.

SURFACE WATER QUALITY

McCoy Creek is located within V* mile of the Electro-Voice site and runs from thesouthwest to the northeast. The creek discharges into the St. Joseph River about1 mile downstream from the site. Figure 2-6, following page 2-8, shows the locationof McCoy Creek and the 100-year flood plain.

VOCs migrating offsite in the groundwater discharge into McCoy Creek. Thegroundwater elevation contour map, Figure 2-4, following page 2-1, indicates thatsome of the contaminated groundwater flows beneath McCoy Creek near streamgauge MC-6, resulting in part from a dam structure located just downstream of MC-6.Contaminated groundwater that flows beneath McCoy Creek upstream from the dam

then flows northeast and discharges into McCoy Creek downstream from the dam.

Surface water sampling and analysis of McCoy Creek was not performed during thePhase I or Phase II sampling events. Analysis of groundwater from MW-26S, locatednear McCoy Creek, revealed the presence of TCE (76 /ig/L) and DCE (5 ftg/L).These were among the highest concentrations of organic compounds observed offsiteand downgradient from EV. An estimate of the concentrations of these compoundsin McCoy Creek was made using a mass-balance dilution equation. The calculationsrevealed that the potential maximum concentrations of TCE and DCE in McCoyCreek upon mixing would be 0.62 /tg/L and 0.04 ftg/L, respectively. Theseconcentrations are below the detection limit for most analytical methods and wellbelow the CLP regular analytical services method detection limit of 5 /ig/L. Thecalculations assume complete and instantaneous mixing of the contaminant in thesurface water. The assumption of complete mixing is not valid within a mixing zoneextending downstream of the contaminant release. Concentrations may be higherwithin the mixing zone than the concentrations estimated by the mass-balance dilutionequation.

The U.S. EPA sampled McCoy Creek in October 1990 and observed detectableconcentrations of TCE similar to the concentrations modeled for use in the riskassessment (0.6 to 0.7 /ig/L).

AIR QUALITY

Soil gas emanating from the boreholes was monitored to ensure that drillingpersonnel would not be exposed to elevated levels of CH4, CO, H2S, or VOCs or to adepleted level of O2. Elevated levels of VOCs were detected in the dry well andformer north lagoon as vapors emanated from the borehole and from subsurface soilsbeing sampled. Elevated concentrations of VOCs detected in the borehole and fromsubsurface soils at MW-27A may be attributed to the location of the formerunderground storage tank.

2-8

FOURTH ST.

eo>01

u.

v>

8o

^— .̂ _ Approximate SueProperty Boundaries

5001

SCALE IN FEETFigure 2-6

100-Year Flood PlainElectro-Voice, Inc. FS

CONTAMINANT FATE AND TRANSPORTOrganic and inorganic contaminants from the former fuel tank and lagoon area soilswere found in low concentrations and do not appear at elevated levels in thegroundwater. It appears that attenuation of contaminants in the vadose zone is thedominant process limiting the release of contaminants from these areas.

Transport of contaminants by erosion or wind is not expected to occur because theground surface is stabilized by vegetation. There is no evidence of significant surfaceerosion in the source areas.

The dry well area appears to be releasing organic contaminants that are beingtransported offsite by groundwater (TCE and DCE). The maximum offsite summedconcentration of total VOCs was 101 /ug/L at MW-23 (69 /ig/L TCE, 32 /ig/L DCE).These contaminants migrate with the groundwater. Some are discharged into McCoyCreek and some flow under the creek.

Low concentrations of VOCs may be volatilizing to the atmosphere from nearsubsurface soils in the dry well area. Ambient VOC concentrations in the atmospherewere measured for health and safety purposes.

Results of the private well survey indicate that no groundwater is used within thezone of contamination. A municipal groundwater system supplies water to the entirecommunity. The groundwater supply has little potential of being affected bycontaminants originating from the EV site because it is 2,000 feet west of the EVplume.

The water table is close to the land surface near McCoy Creek, and groundwaterseepage into basements reportedly occurs at several businesses along East FrontStreet. Sumps are installed at several businesses to pump water to the storm sewer.Most Front Street businesses are located west of (outside) the VOC plume attributedto the EV site. Only one business has been identified to be a likely basementreceptor within the zone of groundwater contamination. Analytical results fromnearby upgradient well MW-24 indicate the presence of TCE at a concentration of17 /tig/L. Because of the possible presence of TCE, there is the potential for theinhalation of vapors.

Groundwater discharges to McCoy Creek north of Front Street in downtownBuchanan. A small dam located at Dewey Street keeps the water surface of McCoyCreek at an artificially high level upstream (west) of the dam. Minor groundwaterdischarge (estimated at 20 percent of the total groundwater flux in this area) occursto McCoy Creek along this stretch (north of MW-26). The balance of groundwaterflows beneath McCoy Creek before discharging to the creek near MC-7 downstreamof the dam (see Figure 2-4, following page 2-1).

BASELINE RISK ASSESSMENT

The object of a baseline risk assessment is to identify potential pathways of exposurefor human and environmental receptors and quantitatively to estimate the exposuresthat could occur and the risks associated with them. The risk estimate is used, along

2-9

with other information, to determine whether remedial measures are needed at thesite and, if so, the estimates to be considered in selecting appropriate remedialmeasures and RAOs.

Environmental concerns associated with the site include soil contamination by organiccompounds and arsenic in the dry well area, soil contamination by metals in the

!, former lagoon area, and groundwater contamination consisting mainly of VOCs atand downgradient of the site. A conceptual site model was developed to show thecontaminant migration and potential exposure pathways for both current and future

i site use.

HUMAN HEALTH RISK ASSESSMENTiRisks due to carcinogenic and noncarcinogenic contaminants are assessed differently.Carcinogenic risks are assessed by multiplying the estimated daily intake of a

! carcinogen by its estimated slope factor to obtain the estimated risk, expressed as theprobability of that exposure resulting in an excess incidence of cancer. The estimatedexcess lifetime cancer risks for potentially exposed populations are given in Table 2-1

; for existing land use conditions and in Table 2-2 for potential future residential use ofJj the site.

J The potential for adverse effects resulting from exposure to noncarcinogens isassessed by comparing the daily intake of a substance to its reference dose. Thiscomparison is performed by calculating the ratio of the estimated intake to thecorresponding reference dose, which is called the hazard index. If the hazard index is

1 less than 1, no adverse effects would be expected; however, if it is greater than 1,-* adverse effects could be possible. The estimated hazard indexes for potentially

exposed populations are listed in Table 2-3 for current land use conditions and in| Table 2-4 for future residential use of the site.

Under existing land use conditions, the only pathway for which the estimatedi potential carcinogenic risk reached the benchmark level of 1 x 10"6 was inhalation ofJ vapors emanating from the ground near the former dry well by EV workers, assuming

reasonable maximum exposure conditions. The estimated potential risk for this\ pathway was 1 x 10"6, just reaching the benchmark level. That risk is due primarily toJ the potential for vinyl chloride to diffuse to the ground surface from the groundwater

and for benzene, PCE, and TCE to diffuse to the ground surface from contaminated, soils. It should be noted that the estimated air concentrations of VOCs near the dryy well are about 1,000 times below the maximum work place air concentrations of these

compounds considered acceptable by the Occupational Safety and HealthAdministration (OSHA).

i.; None of the exposure pathways that are complete under existing land use conditionswere estimated to result in potential exposures to noncarcinogenic contaminants that

I might produce adverse health effects. The largest estimated hazard index was 0.03I for a child trespassing in the lagoon area.

I The estimated potential carcinogenic risk for employees of Front Street businessesfrom contaminants known to be present in the groundwater in that area, andassuming reasonable maximum exposure conditions, was 8 x 10"7 due to TCE in thegroundwater, which can evaporate from basement sumps or diffuse through cracks in

2-10

Table 2-1Summary of Estimated Excess Lifetime Cancer Risks Under Current Land Use Conditions

Exposure Setting

Onsite workers, inhalation of vapors from dry well area soilReasonable Maximum Exposure

Children trespassing in dry well area, dermal contact withand ingestion of soils, inhalation of vapors from soils

Reasonable Maximum Exposure

Children trespassing in lagoon area, dermal contact withand ingestion of soils, inhalation of vapors from soils

Reasonable Maximum Exposure

Workers at Front St. businesses, infiltration of vaporsinto basement, inhalation exposure indoors

Reasonable Maximum ExposureRME + (VC)*

Recreational fisherman using McCoy Creek, ingestionand dermal exposure to water, fish ingestion

Reasonable Maximum ExposureRME + (VC)*

Receptor

Adult

1 x 10"6

N/A

N/A

8 x icr75 x KT4

3x 1CT81 x 10'7

9-year-old

Child

N/A

3 x Ifr7

3 x 10-7

N/AN/A

N/AN/A

Exposure Routesin Order ofImportance

Inhalation

Ingestion,inhalation

Ingestion

Inhalation

Fish ingestion,water ingestion,dermal contact

Chemicals PrimarilyResponsible for Risksin Order of Importance

VC, BNZ, PCE, andTCE

AS, VC, BNZ, PCE, andTCE

AS

(VC)*, TCE

(VC)*, TCE

Key:AS Arsenic TCE TrichloroetheneBNZ Benzene VC Vinyl ChloridePCE Tetrachloroethene (Perchloroethene) NA Not applicable

*If present in groundwater at qualitative detection limit.

GLT172A)86.51

Table 2-2Summary of Estimated Excess Lifetime Cancer Risks Assuming Future Residential Use of the Site

(Page 1 of 2)

Exposure Setting

Residential use at dry well location, outdoor soil exposures,ingcstion, dermal contact and inhalation of vapors

Reasonable Maximum Exposure

Residential use at dry well location, infiltration of vapors,inhalation indoors only

Reasonable Maximum Exposure

Residential use of groundwater for drinking and showeringReasonable Maximum Exposure

Overall residential use at dry well locationReasonable Maximum Exposure

Receptor

Adult

3 x ID'5

1 x 10'5

9x ID"4

9x 10"4

4-year-old

Child

5 x ID'5

8x KT6

4x 1Q-4

5 x ID"4

ExposureRoutes inOrder of

Importance

Ingestion,inhalation,dermal contact

Inhalation

Inhalation/showering,water ingestion,dermal/showering

Inhalation/showering,water ingestion,inhalation ofindoor air

Chemicals PrimarilyResponsible for Risksin Order of Importance

PAHs, VC, PCBs, PCE,BNZ, AS

VC, BNZ, PCE, TCE,PCBs

VC, 1,2-DCA, BNZ,TCE

VC, 1,2-DCA, BNZ,PCE, TCE, PAHs, PCBs

Table 2-2Summary of Estimated Excess Lifetime Cancer Risks Assuming Future Residential Use of the Site

(Page 2 of 2)

Exposure Setting

Receptor

Adult

4-year-old

Child

ExposureRoutes inOrder of

Importance

Chemicals PrimarilyResponsible for Risksin Order of Importance

Residential use of the lagoon location, dermal contact with andingestion of soils, inhalation of vapors from soils

Reasonable Maximum Exposure, North LagoonReasonable Maximum Exposure, South Lagoon

9 x3 x

10-'10-1

1 x 104 x 10

Ingestion AS

Key:AS ArsenicBNZ Benzene1,2-DCA 1,2-DichloroethanePAHs Carcinogenic Polycyclic Aromatic HydrocarbonsPCBs Polychlorinated BiphenylsPCE Tetrachloroethene (Perchloroethenc)TCE TrichloroetheneVC Vinyl Chloride

*lf present in groundwater at qualitative detection limit.

GLT172/087.51

Table 2-3Summary of Estimated Noncarcinogenic Hazard Indexes Under Current Land Use Conditions

Exposure Setting

Onsite workers, inhalation of vapors from dry well area soilsReasonable Maximum Exposure

Children trespassing in the dry well area, inhalation of vapors from soilsReasonable Maximum Exposure

Children trespassing in lagoon area, dermal contact with and ingestionof soils, inhalation of vapors from soils

Reasonable Maximum Exposure, North LagoonReasonable Maximum Exposure, South Lagoon

Workers at Front St. businesses, infiltration of vapors into basement,inhalation exposure indoors

Reasonable Maximum Exposure

Recreational fisherman using McCoy Creek, ingestion and dermalexposure to water, fish ingestion

Reasonable Maximum Exposure

Receptor

Adult

0.03

N/A

N/AN/A

0.0006

0.000004

9-year-old

Child

N/A

0.03

0.050.04

N/A

N/A

ExposureRoutes inOrder of

Importance

Inhalation

Inhalation

Ingestion,dermal contact

Inhalation

Fish ingestion,water ingestion,dermal contact

Chemicals PrimarilyResponsible for Risksin Order of Importance

ALK, PCE, ALKBNZ,XYL, TOL, and ETBNZ

ALK, PCE, ALKBNZ,XYL, and ETBNZ

Lead, cadmium

1,2-DCE

1,2-DCE

Key:ALK Alkanes (C-8 to C-13)ALKBNZ Alkylbenzenes1,2-DCE 1,2-DichloroetheneETBNZ EthylbenzenePCE Tetrachloroethene (Perchloroethene)TOL TolueneXYL XyleneNA Not Applicable

GLT 172/088.51

Table 2-4Summary of Estimated Noncarcinogenic Hazard Indexes Assuming Future Residential Use of Site

Exposure Setting

Residential use at dry well location, outdoor soil exposures,ingestion, dermal contact and inhalation of vapors

Reasonable Maximum Exposure

Residential use at dry well location, infiltration of vapors, inhalationindoors only

Reasonable Maximum Exposure

Residential use of groundwater for drinking and showeringReasonable Maximum Exposure

Overall residential use at dry well locationReasonable Maximum Exposure

Residential use of lagoon location, dermal contact with and ingestion ofsoils, inhalation of vapor from soils

Reasonable Maximum Exposure, North LagoonReasonable Maximum Exposure, South Lagoon

Receptor

Adult

0.1

0.2

2

2

0.20.1

4-year-old

Child

0.6

0.1

18

19

20.8

Exposure Routesin Order ofImportance

Inhalationingestion

Inhalation

Inhalation/showering, wateringestion,dermal/showering

Inhalation/showering,water ingestion,inhalation ofindoor andoutdoor air

Ingestion

Chemicals PrimarilyResponsible for Risksin Order of Importance

ALK, NAP, PCE, TOL,ALKBNZ, ETBNZ,

XYL

ALK, PCE, ALKBNZ,XYL, TOL, ETBNZ

XYL, ALKBNZ,ETBNZ, NAP, TOL,

1,2-DCE

XYL, ALKBNZ,ETBNZ, NAP, ALK,TOL, 1,2-DCE, PCE

Lead, cadmium

Key:ALK Alkanes (C-8 to C-13) NAP NapthaleneALKBNZ Alkylbenzenes PCE Tetrachloroethene (Perchloroethene)1,2-DCE 1,2-Dichloroethene TOL TolueneETBNZ Ethylbenzene XYL Xylene

GLT172/089.51

basement floors or walls, mix with the indoor air, and be inhaled by persons workingin those buildings.

Vinyl chloride has been detected in the groundwater near these businesses. It couldbe present at concentrations below its analytical method detection limit but highenough to pose a health risk. To take this possibility into account, vinyl chloride wasassumed to be present at its practical quantitation limit (5 ftg/L). The hypotheticalcarcinogenic risk posed to Front Street business workers if vinyl chloride were presentat that concentration was estimated to be 5 x 10"*.

The estimated air concentration of TCE in the basement and the hypothetical airconcentration of vinyl chloride are also well below their respective OSHA PermissibleExposure Limits (PELs). For TCE, the estimated basement air concentration was0.000432 mg/m3, whereas the OSHA PEL is 270 mg/m3. For vinyl chloride, thehypothetical air concentration was estimated to be 0.115 mg/m3, while its PEL is8 mg/m3.

TCE was the only contaminant detected in the creek. DCE and vinyl chloride werenot detected in McCoy Creek, but because vinyl chloride is a potential degradationproduct of TCE and DCE and it is present in the groundwater, its presence wasassumed at 5 pig/L as an alternative for the reasonable maximum exposure setting.The same assumption was made for DCE. Although vinyl chloride is in thegroundwater and assumed to be in McCoy Creek, the risk assessment concluded thatthe existing lifetime cancer risk is significantly less than the benchmark level of1 x 10"* indicated in Table 2-1.

The fuel tank area soils exhibit subsurface soil contamination, but the groundwater inthat area does not appear to have been adversely affected. In addition, current and

| future risks of human contact with the fuel tank area soils are considered1 inconsequential based on existing data.

I To provide a basis for risk assessment calculations for incidental exposure to lagoon1 soils, the contaminant concentration of surface soils was assumed to be equivalent to

the maximum concentrations found in subsurface soil samples collected from the] lagoon area. This was corroborated by surface soil samples taken in March 1991.

The potential future risks to residents, should the EV property be converted toT residential use without any remedial action, would be due primarily to the proximityI of the organic dry well area soil contaminants to the ground surface and to their

volatility and toxiciry. There is also a potential risk due to the presence of arsenic inthe dry well area soils and of arsenic, lead, and cadmium in the lagoon area soils.

I Future risks from the potential use of groundwater for domestic supply purposeswould be due primarily to the volatility and toxicity of the contaminants in thegroundwater. The future potential risks that were estimated to reach or exceed 10"6for the following onsite pathways are:

]J

Dermal contact with and incidental ingestion of the soil and inhalationof soil vapors, both indoors and outdoors, in the dry well area bypotential future site residents

2-11

• Residential use of groundwater for drinking and showering

• Incidental ingestion of lagoon area soils by potential future residents

ECOLOGICAL ASSESSMENT

An ecological assessment of the EV site was undertaken to identify environmentalresources at or near the site that might be affected adversely by site contaminants.An ecological assessment is a qualitative or quantitative appraisal of the actual orpotential effects of hazardous waste site contaminants on plants and animals otherthan humans and domesticated species.

Soil

Under existing site use conditions, the contaminants are not expected to result inadverse effects on terrestrial ecosystems.

No rare or endangered species are known to reside at the EV site, nor are therespecies of special economic or recreational value for which the EV site serves ascritical habitat. The site is surrounded by a residential area; therefore, it is unlikelythat it would be used to graze livestock. The site is heavily vegetated and populatedby various birds and small animals. However, because rare or endangered species areabsent, as are other important species for which the site would serve as criticalhabitat, there do not appear to be any environmental receptors at the site that wouldbe of potential concern.

Groundwater

Groundwater is 30 to 50 feet deep at the site and does not discharge to the sitesurface. Therefore, groundwater contaminants are not expected to have any onsiteecological impacts.

Groundwater containing TCE and DCE discharges to McCoy Creek about J/2 milenorth of the site. McCoy Creek is the main regional surface water feature of interestbecause it represents the discharge boundary for the upper aquifer in the studyregion.

McCoy Creek

McCoy Creek is a freshwater stream located approximately Vi mile north of the site.The creek flows in a northeasterly direction through the City of Buchanan to itsconfluence with the St. Joseph River. McCoy Creek is on the MDNR director's listdesignating it as protected trout stream. Brown trout are stocked by the MDNR atapproximately 15 locations along the creek, all of which are upstream of the City ofBuchanan and the area where the groundwater plume discharges to the creek.

TCE, DCE, and vinyl chloride were the only contaminants determined to be migratinginto the creek. Vinyl chloride was detected in the groundwater near McCoy Creek.But because vinyl chloride is a degradation product of TCE and DCE, it was assumedto be present in both groundwater and McCoy Creek.

2-12

Exposure routes for aquatic species include dermal absorption, ingestion, andrespiration. Mammals and water fowl may occasionally use the creek but are unlikelyto spend sufficient time in the area for their exposure to approach that of aquaticspecies.

The two-step quotient method was used to assess risk in the McCoy Creek aquaticsystem. First, an environmental concern level (ECL) was derived by applying anuncertainty factor to the lowest observed effect concentration or the no observedeffect concentration obtained from the toxicological literature. The ratio of thepredicted environmental concentration to the ECL is then calculated for theevaluation of risks. When this ratio exceeds one, a significant risk of adverse effectsmay exist. Site-specific ECLs were derived based on available toxicological data. TheECL derived for DCE was 1.0; for TCE it was 0.001 mg/L. Information available inthe literature regarding vinyl chloride is inadequate for the derivation of ECLs. Vinylchloride is carcinogenic in humans and may be tumorigenic in fish. At theconcentration potentially reaching McCoy Creek, vinyl chloride is not expected toremain in the water column or sediment long enough to produce an adverse healtheffect on aquatic species.

The ratios of the estimated reasonable maximum concentration (MC) of eachcontaminant of concern to its ECL are presented in Table 2-5. The MC/ECL ratio isless than one for both DCE and TCE in McCoy Creek. No significant effects onaquatic organisms would be expected to result from groundwater contaminantsdischarged to McCoy Creek.

Table 2-5MC/ECL Ratios for Aquatic Species*

Chemical

DCE

TCE

EstimatedReasonableMaximum

Concentration(MC)

1.4 x 10-4

5.3 x 10"

Lowest DerivedEnvironmentalConcern Level

(ECL)

1.0

0.001

MC/ECL

1.4 x ID"4

0.53

*Concentrations are expressed as mg/L

GLT181/003.51

2-13

Section 3REMEDIAL ACTION OBJECTIVES AND GOALS

Remedial action objectives are general requirements that the remediation shouldachieve. Remedial action goals are the specific chemical concentrations that theremedial action plans should achieve to provide adequate protection of human healthand the environment. Remedial action objectives and goals are based on generalremedial objectives set forth in the National Oil and Hazardous Substances PollutionContingency Plan (NCP), CERCLA and the Superfund Amendments andReauthorization Act (SARA), site-specific exposure pathways, and applicable orrelevant and appropriate requirements (ARARs) from state and federalenvironmental laws. During the FS, remedial action objectives are determined andpreliminary remedial action goals are developed. Final remedial action goals areestablished when the remedy is selected. This section presents the development ofthe remedial action objectives and goals for the EV site.

NCP AND CERCLA REQUIREMENTS

The general requirements for remedial action at the EV site are described in theNCP and in CERCLA and its amendments. The NCP states: "The national goal ofthe remedy selection process is to select remedies that are protective of human healthand the environment, that maintain protection over time, and that minimize untreatedwaste." [40 CFR 300.430 (a)(i).] It is more specific on several issues regardingexpectations for remedial action:

• The EPA expects treatment to be used to address the principal threatsposed by a site wherever practicable. Principal threats for whichtreatment is most likely to be appropriate include liquids, areascontaminated with high concentrations of toxic compounds, and highlymobile materials. [40 CFR 300.430 (a)(iii)(A)]

• The EPA expects engineering controls, such as containment, to be usedfor waste that poses a relatively low long-term threat or wheretreatment is impracticable. [40 CFR 300.430 (a)(iii)(B)]

• The EPA expects a combination of methods to be used, as appropriate,to achieve protection of human health and the environment. [40 CFR300.430 (a)(iii)(C)]

• The EPA expects institutional controls, such as water use and deedrestrictions, to be used to supplement engineering controls asappropriate for short- and long-term management to prevent or limitexposure to hazardous substances, pollutants, or contaminants.Institutional controls must not be substituted for active responsemeasures as the sole remedy unless such active measures aredetermined not to be practicable. [40 CFR 300.430 (a)(iii)(D)]

• The EPA expects to consider using innovative technology when suchtechnology offers the potential for comparable or superior treatment

3-1

performance or implementability, fewer or lesser adverse impacts thanother available approaches, or lower costs for similar levels ofperformance than demonstrated technologies. [40 CFR 300.430

• The EPA expects to return usable ground waters to their beneficial useswherever practicable within a time period that is reasonable given theparticular circumstances of the site. [40 CFR 300.430 (a)(iii)(F)].

Several of these expectations are reiterated within the SARA. The SARA states that:

• Remedial actions "shall attain a degree of cleanup of hazardoussubstances, pollutants, and contaminants released into the environmentand of control of further releases at a minimum which assuresprotection of human health and the environment." [Section 121(d)]

• Remedial actions "in which treatment that permanently and significantlyreduces the volume, toxicity, or mobility of the hazardous substances,pollutants, and contaminants is a principal element" are preferred.[Section 121(b)]

• The selected remedy shall comply with or attain the level of any"standard, requirement, criteria, or limitation under any Federalenvironmental law ... or any promulgated standard, requirement,criteria, or limitation under a State environmental or facility siting lawthat is more stringent than any Federal standard, requirement, criteria,or limitation." (Section 121(d)(2)(A))

SITE-SPECIFIC EXPOSURE PATHWAYS

Remedial action objectives and goals must also take into consideration site-specificexposure pathways and their associated risk. The results of the risk assessmentcompleted as part of the RI are summarized Section 2.

Key exposure pathways for the existing uses of the site are:

• Inhalation of vapors from dry well area soils• Inhalation of vapors from contaminated groundwater in basements

Key exposure pathways for potential future uses of the site are:

• Direct contact with soil from residential use at the dry well area soil• Ingestion of contaminated groundwater

The NCP states that for systemic toxicants acceptable exposure levels shall representconcentration levels to which the human population may be exposed without adverseeffect during a lifetime or part of a lifetime, incorporating an adequate margin ofsafety [40 CFR 300.430 (e)(2)(i)(A)(l)]. The NCP states that for known or suspectedcarcinogens, acceptable exposure levels are concentration levels that represent anexcess upperbound lifetime cancer risk to an individual of between 10"4 and 10"6. The10"6 risk level is to be used as the point of departure for determining remediation

3-2

goals where ARARs are unavailable or not sufficiently protective [40 CFR !300.430 (e)(2)(i)(A)(2)].

IConcentrations of soil and groundwater contaminants associated with unacceptable 'levels of carcinogenic or noncarcinogenic risk are presented at the end of this section.

iI

POTENTIAL ARARS

DEFINITION OF ARARS

Remedial actions for the site are based on defining areas of contaminated media andthen acting on those media. What constitutes being "contaminated" and the goals of Ithe remedial action are often based on regulatory requirements. Such requirements Ican also restrict or establish methods of remediation. Section 121(d)(2)(A) ofCERCLA specifies that Superfund remedial actions must meet any federal standards, {requirements, criteria, or limitations that are determined legally to be applicable or [relevant and appropriate requirements (ARARs). CERCLA also requires that stateARARs be met if they are more stringent than federal requirements. Remedial ~-" iactions must take into account the "to be considered" criteria (TBCs) or guidelines if }the ARARs do not address a particular situation.

CERCLA provides the definition of "applicable" and "relevant and appropriate" !requirements. Applicable requirements are cleanup standards, standards of control,substantive requirements, criteria, or limitations promulgated under federalenvironmental or state environmental law or facility siting laws that specifically |address a hazardous substance, pollutant, contaminant, remedial action, location, or *other circumstance at a CERCLA site. Relevant and appropriate requirements arecleanup standards, standards of control, substantive requirements, criteria, or 5limitations promulgated under federal environmental or state environmental or facility Isiting laws that address problems or situations sufficiently similar to thoseencountered at a CERCLA site that their use is well suited for that particular site. r

EPA Region 5 and the State of Michigan determine which requirements areapplicable or relevant and appropriate by considering the type of remedial actionscontemplated, the hazardous substances present, the waste characteristics, the iphysical characteristics of the site, and other appropriate factors. Only thesubstantive portions of the requirements are considered potential ARARs. CERCLA lprocedural and administrative requirements provide safeguards similar to those y*provided under other laws. Under Section 121(e) of CERCLA, federal, state, andlocal permits are not required for the portions of CERCLA cleanups conductedentirely onsite, or within the real extent of contamination as long as the actions are Iselected and carried out in compliance with Section 121.

Remedial actions must also take in to account TBCs if ARARs do not address a jparticular situation or action. TBCs are unenforceable criteria, advisories, or Iguidance issued by federal or state agencies. They are not legally binding and do nothave the status of ARARs. They are generally considered along with the ARARs, if /appropriate, in determining the level of cleanup required for protection of health and :the environment. Examples of TBCs are reference doses and potency factors for

3-3

ingestion of noncarcinogenic and carcinogenic compounds used in the risk assessment(see Appendix A of the RI report).

j CERCLA Section 121 provides that, under certain circumstances, an otherwiseapplicable or relevant and appropriate requirement may be waived. Such waiversapply only to the attainment of the ARAR; other statutory requirements (e.g., that

| remedies be protective of human health and the environment) cannot be waived.CERCLA Section 121 also provides for establishing alternative concentration levels(ACLs; Section 121(d)(2)(B)(ii)) for groundwater beyond the facility boundary.

i However, because there are potential exposure points between the facility boundaryand the groundwater discharge location, the ACLs are not applicable to this site.

; The federal ARARs and TBCs have been placed in three specific categories:

Chemical-specific ARARs are laws and requirements that regulate the release; of contaminants to the environment. They generally place limits on! concentrations of specific chemicals that can be released to or be present in

the environment. If a chemical is subject to more than one requirement, theI more stringent requirement should generally be applied. An example ofj chemical-specific ARARs is the standards in the Safe Drinking Water Act.

jI

Location-specific ARARs relate to the geographic characteristics of the site.They include regulations pertaining to activities within wetlands, flood plains,and historic sites. They may limit the type of remedial action that can beimplemented or place added constraints on the cleanup process. Examples ofpotential location-specific ARARs are RCRA regulations pertaining to facilitylocation and Executive Orders in the Protection of Wetlands.

Action-specific ARARs define acceptable treatment and disposal proceduresfor hazardous substances. They are generally technology-based regulations,including performance and design standards, identified by the types of remedialaction under consideration. Examples of potential action-specific ARARs arethe Clean Air Act and the Land Disposal Restrictions.

ARARS FOR THE ELECTRO-VOICE SITE

A more detailed discussion and listing of potential ARARs for the EV site ispresented in Appendix A.

Chemical-specific ARARS

Important federal chemical-specific ARARs include the Clean Water Act and theSafe Drinking Water Act. The NCP states that the remedial action goals forgroundwater should attain maximum contaminant level goals (MCLGs) establishedunder the Safe Drinking Water Act, when MCLGs are set at levels above zero.These levels should be attained by remedial actions for ground or surface waters thatare current or potential sources of drinking water, where the MCLGs are relevantand appropriate under the circumstances of the release. If an MCLG is determinednot to be appropriate, the maximum contaminant level (MCL) shall be attainedwhere relevant and appropriate to the circumstances of the release (40 CFR 300.430

{ (e)(2)(i)(B)). Where the MCLG for a contaminant has been set at zero, the MCL

• 3-4

]

promulgated for that contaminant under the Safe Drinking Water Act shall beattained by remedial actions for ground waters that are current or potential sources ofdrinking water, where the MCL is relevant and appropriate under the circumstancesof the release. Because the aquifer is considered a potential source of drinking water,the MCLs are considered relevant and appropriate (see ARARs discussion inAppendix A). The MCLs and MCLGs for the contaminants of concern are presentedat the end of this section.

Michigan Act 307 also identifies goals for remedial actions for cleanup of hazardouswaste sites. The Act states that all remedial actions shall be protective of the publichealth, safety, and welfare and the environment and natural resources and thatremoval, treatment, or containment measures shall be implemented to attain one ormore of the following degrees of cleanup:

• Type A—Remediate to background or detection limit.

• Type B—Remediate groundwater to 10"6 risk levels for carcinogens, andthe human life cycle safe concentration for noncarcinogens, secondaryMCLs, or concentrations of hazardous substances that impart adverseaesthetic characteristics to the ground water. Remediate soil to protectgroundwater and surface water from migration of contaminants fromthe soil to these media and to protect against unacceptable risk throughinhalation or direct contact of contaminants.

• Type C—Meet the requirements of protectiveness as determined by asite-specific risk assessment.

A summary of the chemical-specific ARARs that may be applied to the EV site ispresented in Appendix D, Tables D-l to D-3.

Location-Specific ARARs

The only pertinent location-specific ARAR relates to construction of facilities in the100-year flood plain. The source areas are not within the 100-year flood plain and sowould not be affected by this ARAR. Treatment systems constructed near theMcCoy Creek might fall within the flood plain and require special study andmitigation measures. Additional potential location-specific ARARs are identified anddiscussed in Appendix A.

Action-Specific ARARs

Important action-specific ARARs include the state laws pertaining to surface waterdischarge, air stripper offgas emissions, and incineration.

Groundwater Treatment Requirements. Rules 323.2101 through 323.2189 of theMichigan Water Resources Commission Act (Act 245) implement a waste effluentdischarge permit system that is compatible with the National Pollution DischargeElimination System (NPDES). The rules outline acceptable effluent concentrationsand monitoring requirements. CERCLA exempts Superfund sites from the permittingrequirements, but the substantive requirements of the rules must be followed.

3-5

Air Treatment Requirements. Rules 336.1901 through 336.1912 of the Michigan AirPollution Act (Act 348) set treatment requirements for all sources of VOC emissions.Generally, VOC emissions must be treated with the best available control technology(BACT). Both groundwater and soil treatment technologies would discharge VOCs.Each remedial alternative includes emission control measures considered to be BACTtreatment for air emissions.

Incineration Requirements. Rules 299.9623 through 299.9626 of the MichiganHazardous Waste Management Act (Act 64) set performance, design, operation, andtrial burn standards for hazardous waste incinerators. Thermal treatment is includedin some of the remedial alternatives. Any onsite incineration would have to conformto these standards.

SITE-SPECIFIC REMEDIAL ACTION OBJECTIVES AND GOALS

Site-specific remedial action objectives were established for individual media groupsor areas of waste management that are expected to require similar or specialremedial actions, based on similarities in physical characteristics of media, the relativerisk posed by the material, or by distinctions drawn by ARARs. The EV site wasdivided into four waste management areas:

• Dry well area sludge and soil• Fuel tank area soil• Lagoon area soil• Groundwater

The following objectives were established for each of the waste management areas ofthe EV site. Refer to Appendix D for chemical-specific goals.

DRY WELL AREA SLUDGE AND SOIL

The remedial action objectives for the dry well area sludge and soil are:

• Minimization of direct contact with or inhalation or ingestion ofcontaminants that present unacceptable risks to public health

• Minimization of the threat to public health and the environment frommigration of contaminants into the groundwater

Soils in the dry well area consist of topsoil and sandy fill material to a depth of about3 to 8 feet. A brown to greenish-black, odorous, soft and wet material wasencountered at various depths from 3 to 21 feet. The estimated average depth of thesoil material is about 9.3 feet. The material was described as a sludge in the soilboring logs. The volatile contaminants present include BETX and chlorinated volatilecompounds; the semivolatile contaminants include PAHs and phthalates. The drywell area is the only area at the site where PCB and pesticide/herbicidecontamination was encountered. Inorganic contamination at the site is poorlydefined. An insufficient number of samples (two) was collected to determinebackground concentrations properly. Maximum concentrations of inorganic analytesexceeded the average background concentrations for 16 of 18 analytes. This may

3-6

indicate inorganic contamination. Apendix Table D-l summarizes observedconcentrations and potential remedial action goals for soil in the dry well area (seechemical-specific ARARs).

Figure 3-1, following page 3-7, depicts a plan view of the estimated extent of thesludge layer based on physical descriptions from the boring logs and the estimatedextent of soil contamination based on analytical soil sampling results. Figures 3-2, 3-3,and 3-4, following page 3-7, show cross sections of the estimated extent of sludge andsoil contamination. The volume of the sludge layer is estimated to be 2,100 cubicyards, based on a surface area of 6,100 square feet and an average thickness of9.3 feet. The volume of contaminated soil in the dry well area (exclusive of thesludge layer) is estimated to be another 3,000 cubic yards based on the presence orabsence of organic contaminants in soil samples. Thus the total volume ofcontaminated material is about 5,100 cubic yards.

FUEL TANK AREA SOILS

The remedial action objectives for the fuel tank area soils are:

• Minimization of direct contact with or inhalation or ingestion of soilcontaminants that present unacceptable risks to public health

• Minimization of the threat to public health and the environment frommigration of contaminants from the soil into the groundwater

Subsurface soils in the fuel tank area are mostly sands with discontinuous clay layers.No visible contamination was noted in this area during the boring program. Chemicalanalyses indicate that acetone, chloroform and trichloroethene were the only volatilecompounds detected in this area. No semivolatiles or pesticides/PCBs were detectedin samples collected in this area. Samples collected from the fuel tank area were notanalyzed for inorganic analytes.

Concentrations of contaminants measured in fuel tank area soil samples did notexceed any of the potential chemical-specific ARARs.

LAGOON AREA SOIL

The remedial action objectives for the lagoon area soils are:

• Minimization of direct contact with or inhalation or ingestion of soilcontaminants that present unacceptable risks to public health

• Minimization of the threat to public health and the environment frommigration of contaminants from the soil into the groundwater

Soils in the lagoon area are sands with discontinuous clay layers and gravel layers.Some organic contaminants were detected in the lagoon soil, but they were at lowlevels and generally did not exceed any of the remedial action goals. Inorganiccontamination was detected more frequently and at higher concentrations. Maximumconcentrations for 16 of the 18 inorganic analytes exceeded the average backgroundconcentration for those analytes, indicating inorganic contamination may be a

3-7

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Extent of Sludge Lagoon

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Figure 3-1Sludge, VOC, and SVOC

Contaminated Areas and GeologicalCross Section Location Map

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problem in this area. Additional background samples should be collected todetermine which analytes are present above background concentrations.

Appendix Table D-2 summarizes the maximum observed concentrations and potentialremedial action goals (potential chemical-specific ARARs) for the lagoon area soils.Figure 3-1, following page 3-7, identifies the estimated extent of contamination basedon the goals listed in Table 3-3. The volume of contaminated lagoon area soil (fromboth lagoons) is estimated to be 2,000 cubic yards, based on the presence or absenceof organic contamination in soil samples, a surface area of 2,000 square feet, and anestimated average thickness of 13 feet in each lagoon.

GROUNDWATER

The remedial action objectives for the groundwater are:

• Minimization of the ingestion of or direct contact with water havingconcentrations of contaminants exceeding MCLs, exceeding MCLGsgreater than zero, having a total excess lifetime cancer risk of 1 x 10"6,or exceeding an HLCSC

• Minimization offsite migration of contaminants

Figure 3-5, following page 3-8, outlines the estimated extent of contamination, basedon presence or absence of organic contaminants in groundwater samples.

Volatile contaminants detected in the groundwater include chlorinated VOCs andBETX compounds. Semivolatile contaminants include benzoic acid, naphthalene,phthalates, and phenolic compounds.

Appendix Table D-3 summarizes the maximum observed concentrations and potentialremedial action goals (potential chemical-specific ARARs) for groundwater.

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3-8

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1

I

Section 4REMEDIAL TECHNOLOGY DEVELOPMENT

AND SCREENING

Remedial alternatives are assembled from the technologies and process options mostlikely to be compatible with the site's contaminants and physical characteristics. Thischapter presents the evaluation by which certain technologies and process optionswere selected for the remedial alternatives. The development and screening of a listof technologies and process options applicable to the site follows the procedurepresented in the U.S. EPA Interim Final Guidance for Conducting RemedialInvestigations and Feasibility Studies under CERCLA (U.S. EPA 1988).

The procedure for identifying and screening technologies and process options consistsof the following steps:

• Identify general response actions for each environmental medium (e.g.,soil, air, and groundwater) that would address site conditions andachieve some or all of the remedial action objectives presented inSection 3. A general response action is the broadest classification of aremedial action and includes groupings of response actions, such astreatment, disposal, and containment. Each response action could berepresented by one or more technologies.

• Identify and screen specific technologies and process options todetermine which are feasible for achieving the goals of each responseaction. Technologies are general categories of similar treatment.Process options are specific materials, equipment, or methods used toimplement a technology. For example, physical treatment ofgroundwater is a technology; air stripping is a process option used toimplement the technology of physical treatment. This initial screeningeliminates technologies and process options that are clearly notapplicable to the physical site conditions or the substances of concern.

• Evaluate technologies and process options that pass initial screening onthe basis of their effectiveness, implementability, and relative cost tofurther reduce their number. This evaluation constitutes the secondaryscreening. If possible, single technologies or process options areselected to represent each general response action.

After the secondary screening of technologies and process options, the processoptions that remain are combined to form sitewide alternatives capable of meetingthe site objectives. The development of alternatives is described in Section 5.

The two main areas of contaminated soil—the dry well area and lagoon area—aredescribed in Sections 2 and 3. Although the geology and hydrogeology at the twoareas are similar, the nature of the contamination is different. Technologies andprocess options retained in the initial and secondary screenings are consideredapplicable to at least one of the source areas, and sometimes both.

4-1

GENERAL RESPONSE ACTIONS

General response actions are actions that will address the exposure pathwaysidentified in Section 2, and that will achieve the remedial objectives presented inSection 3 by reducing either contaminant levels or the likelihood of exposure to theexisting levels. Potential general response actions for soil and groundwater are:

No actionMonitoringInstitutional controlsContainmentRemoval/collectionTreatmentDisposal

Except for the no-action response, these actions are not mutually exclusive. Mostremedial action alternatives will use some combination of general response actionssuch as soil removal, treatment, and offsite disposal. Combining general responseactions is done as part of development of the alternatives (Section 5).

General response actions for soil and groundwater and the remedial objective theyaddress are listed in Table 4-1. The no-action general response action for the soiland groundwater was considered as required by SARA.

PRELIMINARY TECHNOLOGY SCREENING

Each general response action has a corresponding set of potential remedialtechnologies and process options. Like the general response actions, technologies andprocess options must be directed toward meeting a remedial objective.

The initial phase of screening requires that technologies and process options bechecked for compatibility with site characteristics (e.g., physical and chemicalcharacteristics of the contaminated media) and the contaminants present. Processoptions that were clearly unworkable or inappropriate were eliminated. During thisscreening, process options were addressed independently without considering potentialadvantages or disadvantages when applied in combination with other process options.Figures 4-1 and 4-2, following page 4-2, show the preliminary screening results for thesoil and groundwater treatment technologies.

SECONDARY TECHNOLOGY SCREENING CRITERIA

Incorporating all process options that pass the initial screening into detailedalternatives would result in a cumbersome number of alternatives to evaluate. Toreduce the number of alternatives, technologies and process options that survivedinitial screening were reevaluated on the basis of their effectiveness, implementability,and relative cost. The process op