United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R05-90/129
September 1990
Superfund
Record of Decision:
Oconomowoc Electroplating, Wl
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30272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R05-90/129
3. Recipient1* Accea*ion No.
4. Tin* «nd Subtitle
SUPERFUND RECORD OF DECISION
Oconomowoc Electroplating, WI
First Remedial Action
t. Report Dete
09/20/90
7. Author**)
8. Performing Organization Rept No.
9. Performing Organization Name and Addreea
10. ProfacVTaek/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponeoring Organization Name and Addreu
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report A Period Covered
800/000
14.
15. Supplementary Mote*
16. Abstract (Limit: 200 worde)
The 10.5-acre Oconomowoc Electroplating site encompasses a 5-acre active electroplating
facility and 5 acres of adjacent wetlands in Dodge County, Ashippun, Wisconsin. The
Oconomowoc Electroplating Company's (OEC) facility includes a main building that houses
process lines, a wastewater treatment building, two formerly used wastewater treatment
lagoons, and various storage tank and container deposit areas. Recreational facilities
residences, and businesses that use ground water for their drinking water supply, are i
proximity to the OEC facility. In addition, Davy Creek, a small creek and warm water
sport fishery, flows through the wetlands 500 feet south of the site. Electroplating,
finishing, and degreasing processes performed since 1957 at the OEC facility produce a
multi-source effluent stream contaminated with heavy metals and VOCs. The effluent, as
well as accidental spills and leaks around the property, have resulted in widespread
site contamination. Prior to 1972, untreated wastewaters were discharged directly into
the Davy Creek wetlands, and even after the construction of two treatment lagoons,
untreated wastes and sludge overflowed the lagoons and continued to accumulate in the
wetlands. Lagoon sludge removal was initiated by OEC in 1979 but was never completed,
and therefore, discharge of contaminants, including RCRA-listed hazardous waste (F006),
(See Attached Page)
WI
17. Document Analytic a. Descriptor*
Record of Decision - Oconomowoc Electroplating,
First Remedial Action
Contaminated Media: soil, sediment, debris, sludge, gw, sw
Key Contaminants: VOCs (TCE, toluene, xylenes), and metals (chromium, lead)
b. Mentifiera/Open-Ended Term*
e. COSATI Reid/Group
19. Security Clau (Thl* Report)
None
20. Security a*** (Thie Page)
None
21. No. of Page*
95
22. Price
(See ANSI-Z38.1S)
See Inmtructian* on Remrae
UPIIONAL rVmM 272 (4-77)
(Formerly NTIS-3S)
Department of Commerce
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EPA/ROD/R05-90/129
Oconomowoc Electroplating, WI
;'irst Remedial Action
Abstract (Continued)
continued into the wetlands. An estimated 10,000 square yards of wetlands are
contaminated with metals and cyanide. Hazardous waste was also found in between the
walls and floor of the wastewater treatment building (where it was placed as a sealant),
leaking from waste containers, and spilled in a north parking lot area. Due to its
complexity, the site has been divided into four Operable Units (OU) for remediation: the
surface water, sludge and contaminated soil associated with the two lagoons (OU1); all
other contaminated soil around the DEC facility not associated with the lagoons or found
beneath the manufacturing building, including a fill area, a lowlands area, the drainage
ditches and the parking lot area (OU2); the associated contaminated ground water (OU3);
and the highly contaminated sediment in the Davy Creek wetlands area (OU4). All remedial
actions for the operable units are final except for OU4, which is an interim action.
Further wetland investigation will delineate the final removal area. In addition, if
after further investigation, the building foundation and underlying soil will need
remediating, an appropriate remedial action will be developed to accompany the wetland
remedial action. The primary contaminants of concern affecting the soil, sediment,
debris, sludge, ground water and surface water are VOCs including TCE, toluene, and
xylenes; and metals including chromium and lead.
The selected remedial action for this site includes clean closing the lagoon by
excavating 650 cubic yards of lagoon sludge and surrounding soil, followed by
stabilization and offsite disposal of the material and pumping 72,000 gallons of
contaminated lagoon water (which will be hauled offsite and treated) (OU1); excavating
'/OO cubic yards of soil and debris with offsite treatment and disposal (OU2) ; onsite
ground water pumping and treatment using filtration, ion exchange, air stripping, and
carbon adsorption, followed by onsite discharge to surface water (a treatability study
will be conducted to determine the effectiveness of the ion exchange and to determine the
disposition of the resin) (OU3); excavating 6.000 cubic yards of contaminated sediment
from Davy Creek and adjacent wetlands to a depth of two feet, followed by offsite
stabilization, treatment, and disposal of the contaminated sediments and monitoring of
the area; and performing additional bioassay and risk assessment work to determine final
exposure levels (OU4). The estimated present worth cost for this remedial action is
$7,576,196, which includes an annual O&M cost of $90,569. The present worth costs
associated with each of the four OUs are $490,302 (OU1); $258,667 (OU2); $1,831,805
(OU3), which includes an annual O&M cost of $90,569; and $4,995,422 (OU4).
PERFORMANCE STANDARDS OR GOALS: The lagoon soil excavation levels for the OEC site OU1
will attain background levels consistent with State and Federal (RCRA) clean closure
levels; excavation of OU2 soil will attain a 10~° cumulative carcinogenic risk and a
cumulative HK1 for noncarcinogens. Ground water treatment (OU3) will attain Federal and
State ground water cleanup standards and are based on State preventative action limits
(PALs). Chemical-specific ground water goals*include chromium 5.0 ug/1 (PAL); and TCE
0.18 (PAL). Cleanup levels for Davy Creek and adjacent wetlands have not been
determined.
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RECORD OF DECISION
SELECTED REMEDIAL ALTERNATIVE
FOR THE
OCONOJCWOC EI£CTROPLATING COMPANY, INC. SITE
ASHIPPUN, WISCONSIN
Statement of Basis and Purpose
This decision document presents the selected remedial action for the
Oconomowoc Electroplating Company, Inc., Ashippun, Wisconsin, which was
chosen in accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980, as amended by the Super-fund
Amendments and Reauthorization Act of 1986 (CERdA), and, to the extent
practicable, the National Contingency Plan (NCP). This decision is based
on the administrative record file for this site.
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if
not addressed by implementing the response action in this Record of
Decision, may present an imminent and substantial endangerment to public
health, welfare, or to the environment.
Description of the Selected Remedy
This ROD addresses four Operable Units, or discrete actions at the Site.
The selected remedies are final remedies for the first three operable
units, and will address the principal threats at the site - the ground
water contaminant plume and its source (i.e., contaminated soils and
sludge lagoons). The selected remedy for the fourth operable unit is an
interim remedy and will address contamination in Davy Creek and the
wetlands. The selected remedy consists of the following components:
— Clean close the RCRA subtitle C lagoons by excavation of
approximately 650 cubic yards'of lagoon sludge and surrounding
soils to be treated and disposed of at an off-site RCRA Subtitle
C facility. Treatment of 72,000 gallons of contaminated lagoon
water at a ground-water treatment system installed on site;
— Excavation of approximately 700 cubic yards of contaminated soil
and debris at the site. The contaminated soil will be treated
and disposed of at an off site RCRA Subtitle C disposal facility;
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— Extraction of the ground water contaminant plume to State ground
water quality standards with subsequent treatment. The treated
water shall be discharged into the adjacent Davy Creek in
compliance with the substantive requirements of the Wisconsin
Pollutant Discharge Elimination System (WPDES);
— Excavation of approximately 6,000 cubic yards of contaminated
wetland and Davy Creek sediment to be treated and disposed of at
a RCRA Subtitle C disposal facility. Additional monitoring of
Davy Creek and the wetland will be performed after the
remediation to determine the effectiveness of the remedy.
Statutory Determinations
The first three operable units, which deal with the lagoons, contaminated
soil, and contaminated ground water, are protective of human health and
the environment, comply with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial action,
and are cost-effective. The wetland operable unit is protective of
human health and the environment, complies with Federal and State
requirements that are legally applicable or relevant and appropriate to
the remedial action, and is cost effective, within the limited scope of
the interim action. This action utilizes permanent solutions and
alternative treatment technology, to the maximum extent practicable,
given the limited scope of the action. Because this action does not
constitute the final remedy for Davy Creek and the Wetlands, the
statutory preference for remedies that employ treatment that reduces
toxicity, mobility, or volume as a principal element will be addressed at
the time of the of the final response action. To the extent practicable,
treatment is used as part of the interim action. Subsequent actions are
planned to address fully the principal threats posed by Davy Creek and
the Wetlands.
State Concurrence
The State of Wisconsin concurs with the selected remedy. The Letter of
Concurrence is attached to this Record of Decision.
. Adamkus Date^/
Regional Administrator
/
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Decision Summary
I. Site Location and Description
The Oconomowoc Electroplating Company Inc. (OEC) Site encompasses
an active electroplating facility located at 2572 West Oak
Street, Ashippun, Wisconsin and the adjacent wetlands area
located to the southwest. The cities of Oconomowoc and Watertown
are approximately 8 miles south and 10 miles west of the site,
respectively. Milwaukee lies approximately 35 miles to the
southeast (Figure 1-1). The OEC site occupies approximately 10.5
acres (which includes 5 acres of the OEC facility) in the north-
west 1/4 of the southeast 1/4 of Section 30, Township 9 North,
Range 17 East in the town of Ashippun, in Dodge County,
Wisconsin. A small creek, Davy Creek, is located approximately
500 feet south of the site. Davy Creek, which flows through the
wetlands, is a tributary to the Rock River (Figure 1-2). Davy
Creek is a warm water sport fishery.
The OEC site is bordered on the north by Eva and Oak Streets and
on the south by Davy Creek and the property occupied by the
Ashippun Town Garage (Figure 1-3). Several small businesses line
Oak Street to the northwest, and back up to the Chicago and North
Western Railroad tracks. Residential areas are west (200 ft) and
northwest of the site (200 ft) beyond Eva Street, and southeast
of the site (1400 ft) beyond the Town Garage facilities.
Residents in these areas rely on groundwater for their source of
drinking water. The aquifer is classified as a class IIA
aquifer. Two parks with facilities for playing baseball, skeet
shooting, and picnicking are also near the site. One park with a
playground is adjacent to the Town Garage between Oak Street and
Elm Street, and the other is beyond the residential block to the
northwest.
The natural resource areas associated with the site are the
adjacent wetlands, Davy Creek, and the wildlife associated with
them.
The OEC facility consists of a main building which houses the
office and process lines; a wastewater treatment building (to the
west); parking area (to the north and east); two formerly used
wastewater treatment lagoons (to the south); various storage tank
and container deposit areas; and a fill area and a lowlands area
between the main building and the Town Garage property. The site
plan is shown in Figure 1-3.
II. Site History and Enforcement Activities
OEC has been in operation since 1957. Electroplating processes
performed at the facility used nickel, chrome, zinc, copper,
brass, cadmium, and tin. Finishing processes have included
chromate conversion, coating, and anodizing.
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Geneva /._r\iJ'.^l"B^_«_
^-v- *y" N^NO*"**' •*">a i. *
I0-.*-: hr*c- [i «r f-
2f~W.nthrop Hbr
0 5 10
SCALE IN MILES
ASHIPPUN
CE: STATE MAP
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATING COMPAW
FIGURE 1-1 .
SITE LOCATION MAP
EBASCO SERVICES INCORPORATED
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ill
CONTOUR INTERVAL IS 10 FEET
DATUM IS MEAN SEA LEVEL
0 1000 2000
SCALE IN FEET
SOURCE: USGS IXONIA QUADRANGLE 1959
ENVIRONMENTAL PROTECTION AQENO
OCONOMOWOC ELECTROPLATING COMPAQ
FIGURE 1-2
SITE VICINITY MAP
EBASCO SERVICES INCORPORATED
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1. Main Building
2. Wastewater Treatment Building
3. Parking Area
4. Wastewater Treatment Lagoons
5. Fill Area
6. Town Garage
7. Ballpark Area
8. Residential Areas
9. Lowlands '
10.Commercial Businesses o so too
11.Railroad'Tracks
FIGURE 1-3
STUDY AREA MAP
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Contaminants in the effluent from the electroplating processes
are believed to originate from several sources. Spent process
solutions, the drag-out of various processing baths into
subsequent rinses, accidental spills, leaks, plating tanks filter
systems, and sludges from the bottom of plating baths all
contribute to the waste stream.
Wastewaters formerly generated at the OEC facility can be divided
into three categories: 1) cyanide-bearing (from rinses following
zinc, copper, nickel, brass, and cadmium plating); 2) chromium-
bearing (from chrome and chrome conversion operations); and 3)
acid-alkaline (from rinses following cleaning, anodizing, and
plating operations). Tin plating was suspended at the facility
in 1981 and chromium, copper, and nickel plating in 1982.
Plating of cadmium ceased in October 1984, and as of February
1985, OEC had suspended all cyanide plating processes (WDNR,
1986a). Presently OEC only utilizes a zinc plating process.
In conjunction with the electroplating process, degreasing opera-
tions were also performed at the OEC site and contributed to the
waste stream. A number of volatile organic compounds are
believed to have been used by OEC and include: chloroform; 1-1-
dichloroethane; 1-2 dichloroethane; 1,1-dichloroethylene;
tetrachloroethylene; 1,1,1-trichloroethane, and
trichloroethylene. These contaminants become incorporated in
both sludge bottoms and wastewater streams.
In 1972, OEC constructed two unlined settling lagoons to
supplement their wastewater treatment system. Each lagoon is 60
foot long by 40 foot wide with a sidewall depth of 5 feet (Figure
1-3). The walls are concrete on two sides and sloped gravel on
the others. There is a concrete divider running lengthwise
between the two lagoons. Over the years, both lagoons have
accumulated large volumes of plating sludges. In the past,
untreated plating sludges have overflowed the settling lagoons
and accumulated in the wetlands between the OEC site and Davy
Creek, which is also known as the Davy Creek wetlands.
Prior to 1972, untreated wastewaters were discharged directly
into the wetland area south of the OEC property. In November
1973, after installation of a wastewater treatment system, a
Wisconsin Pollution Discharge Elimination System (WPDES) Permit
was issued for discharging treated wastewater to the creek.
Spills from the wastewater treatment unit are well documented in
the Wisconsin Department of Natural Resources (WDNR) files. In
August 1978, OEC was denied a WPDES Permit by the WDNR; however,
since the facility has appealed the permit denial it is still
operational.
In 1979, the effects of the wastewater discharge and sludge over-
flow were investigated by the Solid Waste Management Division of
the WDNR. Analytical results of stream sediment samples
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collected from Davy Creek downstream of the OEC's discharge point
confirmed the presence of high concentrations of heavy metals
specifically cadmium, chromium, copper, and nickel. An analysis
of surface soil samples collected from the wetlands area adjacent
to the facility showed comparable concentrations of metals.
In 1980, OEC contracted with Waste Management, Inc. to remove the
lagoons' sludge. Approximately one million pounds of sludge were
removed and disposed. However, OEC did not have sufficient funds
to complete the job. These lagoons are now approximately one-
third full of electroplating sludges. Because these sludges are
wastewater treatment sludges from electroplating operations, they
are defined as listed hazardous waste (F006) by the Resource
Conservation and Recovery Act (RCRA) 40 CFR Part 261 Subpart D-
261.31.
In 1981, the WDNR inspection documented that OEC was violating
the 90-day storage limit for hazardous wastes under RCRA.
Although some corrective actions were taken, they were not
sufficient to ameliorate the violation.
OEC is subject to regulations under RCRA for the generation and
storage of hazardous waste (electroplating sludge - F006; Spent
halogenated solvents - F002). In addition, the two wastewater
lagoons which contain the F006 wastes are hazardous waste surface
impoundments which are defined as land disposal units under RCRA.
On July 22, 1980, OEC submitted a RCRA notification to EPA as a
hazardous waste generator. OEC did not submit a RCRA Part A
application or State permit application for interim status as a
treatment, storage or disposal (TSD) facility. At that time, OEC
was storing the hazardous waste described above in containers and
using a surface impoundment. Therefore, OEC never received
interim status as a storage or disposal facility under RCRA, nor
did they receive an interim license for WDNR for those
activities. Since the use of the surface impoundments was in
violation of RCRA requirements, the WDNR required closure of
these lagoons. On December 8, 1988, the WDNR issued a
conditional closure plan approval for the lagoons. This approval
required OEC to clean close these lagoons in accordance with
State RCRA requirements by March, 1989. If OEC could not attain
clean closure of the lagoons, the approval required RCRA closure
of wastes in-place and long-term care requirements be met. .To
date, OEC has never closed the lagoons.
The State of Wisconsin filed suit against OEC in 1981 for alleged
violations of the Wisconsin Pollutant Discharge Elimination
System (WPDES) discharge permit. A guilty decision against OEC
was entered in the Dodge County Circuit Court in March, 1981, but
OEC continued operating its discharge system. Subsequently, in
April 1982, the state moved for remedial sanctions against OEC
for contempt of court. After a hearing on May 10, 1982, OEC was
ordered to cease discharges. The case was finally settled by
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stipulation and DEC was fined $47,000. Since this fine was
levied, OEC has been involved in additional lawsuits because of
WPDES permit and RCRA violations.
In 1983, in order to alleviate the local flooding problem, the
Dodge County Drainage Board proposed to dredge and rechannel a
5,000 foot stretch of the Davy Creek near the OEC facility. How-
ever, the USEPA and the U.S. Army Corps of Engineers disapproved
the dredging proposal because they believed that dredging would
increase the migration of contaminated sediments from the
wetlands into the Rock River.
A Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) preliminary assessment was performed in
May, 1983 by the USEPA Field Investigation Team (FIT). The site
(including the Davy Creek wetlands) received an HRS score of
31.86 and was placed on the National Priorities List (NPL). By
letter dated September 18, 1985, the USEPA notified OEC that they
had been identified as a Potentially Responsible Party (PRP)
under CERCLA for the documented release or threatened release of
hazardous substances. No other responsible parties have been
named to date. On October 9, 1985, OEC informed the USEPA that
they did not have the financial resources to conduct an RI/FS and
formally declined to participate in the CERCLA process.
Between 1983 and 1987, the WDNR sampled residential wells in the
area on seven different occasions. In 1985, three shallow
monitoring wells were installed by the Wisconsin Geological and
Natural History Survey (WGNHS), two near the lagoons and one
southeast of the site on the Town Garage property. Sampling
efforts indicated elevated concentrations of cadmium, nickel, and
zinc, and revealed the presence of 1,1-dichloroethane, 1,1,1-
trichloroethane, and trichloroethylene.
In December, 1985, the WDNR performed a Hazardous and Solid Waste
Amendments (HSWA) initial screening, and in March, 1986, they
prepared the Facility Management Plan and the Site Investigation
Report. In the course of their investigations, the WDNR Horicon
Area Office received an anonymous report of cyanide filled drums
buried on the OEC property eleven to twelve years previously
(1972 to 1973). In October, 1984, two test pits were dug
following an investigation with,a metal detector. Badly
deteriorated sheet metal, metal scrap, and quarter inch metal
wire was found in Test Pit 1, and sheet metal was found in Test
Pit 2.
On April 8, 1986, a WDNR inspection reported that OEC was using
wastewater treatment sludge, a listed hazardous waste (F006)
under RCRA, to seal the space between the floor and walls of the
wastewater treatment building. This sludge spread out of the
building and into the adjacent area. Dead and stressed
vegetation was observed around the building. Additionally, an
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uncovered container full of electroplating sludge overflowed when
snow and rain water accumulated within the container causing it
to spill on the ground. WDNR stated that OEC did not report the
spill or properly cleanup the area. Since that time, some soil
material has been removed from the perimeter of the foundation
and a new curb installed inside the building.
On June 10, 1986, OEC reported that about 10 cubic yards of
sludge had been spilled onto the ground at the north lot. A
month later, on July 14, 1986, the electroplating sludge waste
containers were observed leaking by WDNR staff, violating state
and federal hazardous waste storage and transportation
regulations. The spill has remained on the ground around the
containers.
During the summer of 1986, the Technical Assistance Team (TAT), a
contractor to the USEPA Emergency Response Section, conducted a
limited sediment sampling survey in the wetlands. The analytical
results of these samples indicated high concentrations of metals
and cyanide in the wetlands area immediately south of OEC. In
March and April of 1987, the TAT conducted an extensive sampling
program which covered approximately 300 acres of wetlands along
Davy Creek. This program also included sampling of the OEC
sludge lagoons and soils at the ballpark located southeast of
OEC. The analytical results indicated that approximately 75,000
square feet of the wetlands adjacent to OEC is contaminated with
metals and cyanide associated with the facility's electroplating
process.
In early December, 1987, the U.S. Environmental Response Team
(ERT) conducted a toxicity investigation in the wetlands south of
the OEC site to determine if the contaminated sediments from the
wetlands are toxic to aquatic organisms. The analytical results
indicated severe metals and cyanide contamination of the
sediments in the wetlands. As a result, the sediments from
several locations were considered as being highly toxic. The
toxicity data collected showed conclusively that the
contamination in the wetlands was toxic to fathead minnows and
algae.
CERCLA Enforcement
After OEC declined to participate in the RI/FS, the United States
Environmental Protection Agency (U.S. EPA) decided to use Federal
funds to perform the RI/FS due to OEC's refusal to participate.
The U.S. EPA contracted with EBASCO Inc. to perform the RI/FS on
December 30, 1987, under contract number 68-01-7251, work
assignment number 211-5LM8. The U.S. EPA has erected a partial
fence along Elm Street to minimize access to these wetland areas,
also around the wastewater treatment lagoons (to the southwest)
and the drum storage facility (to the northwest).
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6
A letter was sent to the chairman of Oconomowoc Electroplating on
July 30, 1990 pursuant to Section 122(a) of CERCLA via certified
mail informing OEC that work would be undertaken by U.S. EPA
pursuant to Section 104(a) of CERCLA because OEC appears to lack
the resources to conduct the remedial design and implement the
remedial action. On July 27, 1990, U.S. EPA filed a complaint in
civil court against OEC for past costs associated with the RI/FS,
construction of the fence as described above, and future costs
for design and implementation of the remedial action along with
violations of the Clean Water Act.
III. Highlights of Community Participation
An information repository has been established at the F&M Bank,
533 North Highway 67 in Ashippun, Wisconsin. In accordance with
the requirements of Section 113(k)(l) of CERCLA, the
Administrative Record file is available to the public at the F&M
Bank.
The RI Report for three of the operable units, the lagoons, the
contaminated soils adjacent to the manufacturing buildings and
the ground water, became final on March 23, 1990. A public
meeting to discuss the results of this RI was held on March 28,
1990.
The FS became final on July 9, 1990 and the Proposed Plan was
available for public comment from July 23, 1990 to August 22,
1990. On July 25, 1990 a public meeting was held to present the
proposed plan. Comments received during that public comment
period and the U.S. EPA's responses are included in the attached
Responsiveness Summary, which is part of this Record of Decision
(ROD). The provisions of Sections 113(k)(2)(i-v) and 117 have
been met.
IV. Scope of Operable Unit
This is a complex site and as a result the site has been broken
into four operable units (OUs), or discrete actions. These are:
OU One: Includes the surface water, metal hydroxide sludge
and contaminated soils associated with the two RCRA
Subtitle C lagoons located behind the OEC facility.
OU Two: Includes all other contaminated soil around the OEC
facility not associated with the RCRA lagoons, or beneath
the manufacturing buildings. This includes the fill area,
the lowlands area, the drainage ditches, and the parking
lot.
OU Three: Includes the contaminated groundwater associated
with the site.
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OU Four: Addresses the most highly contaminated sediments
in the Davy Creek/Wetlands area.
The building foundation and underlying soils require
further investigation. Upon further investigation a
appropriate remedial action will be selected if necessary.
There are several principal threats posed by the Oconmowoc site.
This ROD addresses the contamination in all four areas.
Groundwater is contaminated in the shallow aquifer in the
vicinity of the site. The contaminated groundwater poses a
future health threat to the residents who use groundwater as a
drinking water source. Contaminated soil in the fill and lowland
areas poses a threat to children who play in this area and to
workers who may be involved in future development in this area.
The contaminated soil and the sludge lagoons also act as
potential sources of groundwater contamination in the future.
The contaminated sediments are also toxic to the wetland
environment.
The recommended alternative will address the principal threats
through:
1. Removal and treatment of the contaminated groundwater in
order to eliminate any future drinking water health threat;
2. Removal, treatment, and off-site disposal of the
contaminated soil in order to remove the potential
ingestion health threat;
3. Removal, treatment, and off-site disposal of contaminated
wetland sediments in order to minimize toxic effects to the
wetland; and
4. Removal, treatment, and off-site disposal of the sources
of groundwater contamination.
The remedial actions to be implemented for operable units one
through three are considered the final actions for these units.
However, removal of contaminated sediments from Davy Creek and
the wetlands is considered to be an interim action that will be
consistent with the any final remedial action selected for this
Site. Removal of the major portion of contamination at this time
will minimize the environmental damage posed by the contaminated
wetland. Further investigation of the contaminated wetland and
Davy Creek will be conducted to determine if any contaminants
remaining in the wetlands subsequent to the interim action
continue to pose a threat to the environment. After further
investigation is performed in the wetland a final cleanup remedy
for Davy Creek and the wetlands will be made after the
investigation of the building is complete and further remedial
action will be performed as necessary.
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V. Site Characteristics
The primary contaminants of concern are associated with the past
operation and maintenance activities of the Oconomowoc
Electroplating Company. These contaminants include volatile
organic compounds used in the degreasing operation, and
inorganic contaminants derived from the electroplating processes.
The nature and extent of organic and inorganic contaminants in
soil, groundwater, and RCRA Subtitle C lagoon sludge and liquid
in the OEC facility are discussed in the RI Report, and
summarized in the following sections. Also, the extent of
inorganic contaminants in wetlands sediments and surface water as
described by previous investigations (Weston, 1987; Ecology and
Environment, 1988), are summarized below.
A. Soil Contamination
Soil samples were collected from three depth intervals between
ground surface and the water table (approximately 5 feet), and
from a depth interval greater than 5 feet. A total of 61 soil
samples (including 5 duplicates) were collected from three depth
intervals above the water table (0 to 1, 2 to 3, and 4 to 5
feet), and 21 samples (including 1 duplicate) were collected
below the water table. The soil samples collected above the
water table were analyzed for full target compound list (TCL)
organics, and full target analyte list (TAL) inorganics. The
soil samples collected below the water table were analyzed only
for inorganics (not including cyanide).
A.I Depth Interval of 0 to 1 Foot
Analytical results for organics in the soil samples collected
from 0 to 1 foot depth indicated the presence of four volatile
organic contaminants, 1,1-dichloroethane, 1,1,1-trichloroethane,
trichloroethene, and toluene. The concentration distribution of
these organics are shown in Figure 1-5. The highest
concentration levels and the largest number of volatile compounds
were reported in the northern corner of the lowlands area (south
of the fill area) on the eastern edge of the main production
building, and in the far southern corner of the lowlands area in
the drainage pathway. The organic contamination in the lowlands
area is probably from the OEC laboratory which is located on the
eastern side of the main production building.
Soil contaminated with arsenic, cadmium, chromium, copper, lead,
nickel, zinc, and cyanide was found to be widespread over the
entire site area. The distributions of these inorganics are
shown in Figure 1-6 through 1-9. Certain areas in the OEC
property, in particular the southwestern corner of the fill area
on the eastern edge of the main production building, exhibited
high concentrations of these inorganics. The source of these
-------
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• SHALLOW SOIL SAMPLE
® SOIL BORING
• WATER TABLE BORING
MONITORING WELL BORING
Organic Concentrations (ug/hg) In
Soil Samples
-------
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tr (\ I SUB I- / x'x \ . ••" i
SHALLOW SOIL SAMPLE
(ALL LOCATIONS ARE APPROXIMATE)
Inorganic Concentration!
(mg/kg) In Shlllow Soil
Samples: 0-lflOepihlnl
i:i)Ascn SFHVICES INCOHPOI
'" I
lerval I
on/ •!
-------
® SOIL BORING
(ALL LOCATIONS ARE APPROXIMATE)
Inorganic Concentrations (mg/kg)
In Soil Boeing Simples: 0-1 It
Deplh Interval
-------
A. 10»
OI <77
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• WATER TABLE BORING
(ALL LOCATIONS AflE APPROXIMATE)
CNVinONMEMTAL PHOTECriON AGENCY
OCONOMOMOC ELECrnOfVATINB COMWNY
Inorganic Concftntratlons (mg/kg)
In Waler Table Boring Simples:
o-i n Depth Interval
EHASCO SERVICES INCORPORATED
-------
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MW-O 1S_MW-0 ID V
C» MO 120
Ft 110 )J
Mi 130 9.1
120 120
MONITORING WELL
(2) = Duplicate Sample
norginlc Concentrations (mg/kg)
In Monitoring Well Boring
Samples: 0-1 It Depth Interval
-------
inorganic contaminants is likely the spent plating solution used
for laboratory analysis, the wastewater treatment filter cake
which was allowed to dry outside, and the leaching of inorganics
from the lagoons.
A.2 Depth Interval of 2 to 3 Feet
No organic contaminants were identified in the soil samples
collected from 2 to 3 foot depth interval.
Soil contaminated with arsenic, cadmium, chromium, copper, lead,
nickel, zinc, and cyanide was found to be widespread over the
entire site area. The distributions of these inorganics are
shown in Figure 1-10. The eastern corner of the wastewater
treatment lagoons, and the area west of the main production
building contained high concentrations of these inorganics. The
presence of the inorganic contaminants is likely the results of
improper drying and storage of the filter cake from the
wastewater treatment process, and the lagoons overflowing onto
the surrounding area.
A. 3 Depth Interval of 4 to 5 Feet
Analytical results for organics in the soil samples collected
from 4 to 5 foot depth interval indicated the presence of three
volatile organic contaminants, 1,1,1-trichloroethane,
trichloroethene, and toluene. The concentration distributions of
these organics are shown in Figure 1-5. These volatile organic
compounds were detected in the southwestern corner of the fill
area on the eastern edge of the main production building. This
contamination is probably the result of the laboratory sink
draining into the fill area.
Soil contaminated with arsenic, cadmium, chromium, copper, lead,
nickel, zinc, and cyanide was found throughout the fill area.
The distributions of these contaminants are shown in Figure 1-11.
The highest concentrations were reported in the southwestern
corner of the fill area on the eastern edge of the main
production building. The source of this contamination is likely
the filter cake from the wastewater treatment process, and the
OEC laboratory.
A.4 Depth Interval Greater Than 5 Feet
Soil samples collected from a depth interval greater than 5 feet
were analyzed only for inorganics. Five inorganic analytes,
chromium, copper, lead, nickel, and zinc, which were previously
identified as contaminants were detected at low concentrations.
The distributions of these inorganics are shown in Figure 1-12.
-------
® SOIL BORING
• MONITORING WELL BORING
Inorganic Concentrations (mg/hg)
In Soil: 2-3 fl Oepifi Interval
-------
. WATER TABLE BORING
* TEST PIT
Inorganic Concentrations (mg/kg)
in Soil: 4-5 II Depth Interval
-------
;-vl__v^_. S?^
MONITORING WELL
(ALL LOCATIONS ARE APPROXIMATE)
ENVIRONMENIAL PROTECTION AGENCY
OCONOMOWOC ELECTBOa>TINO COUMNV
Inorganic Concinlnlloni (mg/kg)
In Soil: > 5 (I Oeplh Inleml
ck; SURVEY MAP-.^
EBASCO SEHVICES INCORPORATED
-------
10
B. Hydrogeologic Characteristics and Groundwater Contamination
Shallow groundwater at the OEC site occurs in the saturated
unconsolidated deposits which range in thickness from 30 to 60
feet. There are no known residential wells which draw water from
these deposits. The unconsolidated deposits are underlain by a
dolomite which is approximately 30 feet thick in the eastern
portion of the site and totally disappears to the west of the
site. This dolomite constitutes the upper part of the Maquoketa
Shale. Several residential wells near the site are completed in
this zone. The Maquoketa Shale is underlain by dolomite of the
Galena-Platteville aquifer. Several residential wells in the
Ashippun area appear to be withdrawing water from dolomite below
the shale. See Figures 3-3 through 3-5.
Ground-water flow in the unconsolidated deposits is in the west
southwest direction towards Davy Creek. Davy Creek acts as a
discharge (drainage) area for the local groundwater flow system.
The groundwater flow system in the upper dolomite is under
confined or semi-confined conditions since the water levels in
the deep monitoring wells completed in this zone are above the
top of the upper dolomite. The recharge to the upper dolomite is
downward leakage through the unconsolidated deposits overlying
the dolomite. Due to the apparent hydraulic connection between
the unconsolidated deposits and the upper dolomite, it is assumed
that the ground-water flow in the underlying dolomite is similar
to the one in the unconsolidated deposits.
The horizontal hydraulic gradient in the unconsolidated deposits
varies from 1.2 x 10""4 to 1.8 x 10~3 with an average of
9.6 x 10~4 feet/foot in the west-southwest direction. The
horizontal hydraulic gradient in the upper dolomite aquifer
varies from 3.3 x 10""* to 2.4 x 10~3 feet/foot with an average
gradient 1.4 x 10~3.
Groundwater samples were collected from all monitoring wells and
nearby residential wells in two rounds of sampling. A total of
26 groundwater samples (including 3 duplicates) were collected
from the monitoring wells, and 31 samples (including 6
duplicates) were collected from the residential wells. The
groundwater samples were analyzed for full TCL organics and TAL
inorganics, total and simple cyanide, total organics content
(TOC), nitrate-nitrite, ammonia, sulfate, alkalinity, total
suspended solids, and hexavalent chromium.
B.I Monitoring Wells
Analytical results for organics in the groundwater samples
collected from the monitoring wells indicated the presence of six
volatile organic contaminants, 1,1-dichloroethene, 1,1-
dichloroethane, 1,2-dichloroethene (total), 1,2-dichloroethane,
-------
r^—^~?T_\ -V- J >" ' / '
PRESIDENTIAL WELL
4^MONITORING WELL
ENVIRONMENTAL fnOTECTKM AOCNOT
OCQNOMWWC a£CIW)n>TlHO COMWNY
MonHorlng and ResldenUal
Well Locations
EBASCO SERVICES INCORPORATED
-------
MW-02D
MW-04D
MW-08
W*X«;*!»!»fX*H*i*i5"'' • :Xv>X-.**:'v
DOLOMITE ' v^y
V V «•
80 160
SCALE IN FEET
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPiATINa COMPANY
FIGURE 3-4
GENERALIZED GEOLOGIC
CROSS SECTION A-A'
-------
•Ill
B
RW-08
RW-04
MW-03D
RW-11
B'
RW-12 MW-01D
850
. ^ ^ ,s ^-^
DOLOMITE (1)
S-^S±=S±=3
I .v .v .v . '
^ A .\ r^—s
DOLOMITE 1(2)
^ ^x .x .^ _>
CO
UJ
UJ
u.
O
P
UJ
UJ
710 J
«-710
WATER LEVEL
(2-2747)
0 80 160
SCALE IN FEET
(1) Maquokrta
(2) Galena-Plattvill* Dolomite
NOTE: RW Groundwatw Levels arc Based on Measurements Taken After Well Construction.
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATINQ COMPANY
FIGURE 3-5
GENERALIZED GEOLOGIC
CROSS SECTION B-B'
EBASCO SERVICES INCORPORATED
-------
11
1,1,1-trichloroethane, and trichloroethene. These organic com-
pounds were detected in both rounds of sampling. The concentra-
tion distribution of the organic contaminants in groundwater are
shown in Figure 1-13. All detected volatile organic compounds
exceeded the Maximum Contaminant Levels (MCLs) and the Wisconsin
Groundwater Quality Standards. Most of the groundwater
contamination with volatile organics was found to be restricted
to three shallow monitoring wells (MW-02S, MW-05, and MW-06)
located in the downgradient direction. The highest concentra-
tions of volatiles was reported in monitoring well MW-05 located
in the southern corner of the lowlands area.
Groundwater contaminated with cadmium, nickel, and cyanide was
found in shallow monitoring well MW-02S located downgradient in
the drainage ditch southwest of the wastewater treatment in both
rounds of sampling. These concentrations were above Wisconsin
Enforcement Standards (ES) concentrations for cadmium and
cyanide. Cadmium was also detected in shallow monitoring well
MW-06, and cyanide was detected in shallow wells MW-03S, MW-
04S, MW-05, and MW-06. These concentrations were below MCLs but
were above Wisconsin Preventive Action Limits (PALs) for cadmium
in monitoring well MW-06 and cyanide in monitoring wells MW03S
and MW-05. In monitoring wells MW-02D, MW-025 MW-03D, MW-04S, MW-
05, and MW-06, nickel was also detected, (no federal or state
standards exist for nickel). The concentration distributions of
cadmium, nickel, and cyanide in groundwater are shown in Figure
1-14.
B.2 Residential Wells
Analytical results of the first round of groundwater samples
collected from the residential wells indicated the presence of
only acetone at low concentration. In the second round of
groundwater sampling, all volatile organic compounds were
reported below detection limits.
Groundwater contaminated with nickel was detected in several
residential wells at concentrations above background levels. The
concentration distribution of nickel in residential well samples
is shown in figure 1-15. The highest concentrations of nickel
were reported in residential wells RW-06 (87.5 ppb) and RW-07
(75.8 ppb) located west of the .OEC facility in a downgradient
direction. The Federal lifetime health advisory for nickel is 100
ppb. RW-07 also had ,elevated concentrations of cadmium, lead and
zinc. It is not known whether the completion zone of these
residential wells is in the upper dolomite or the lower dolomite.
No federal MCLs/non-zero MCLGs were exceeded in the residential
wells, although the State's PALs for chromium was exceeded in RW-
07 (19.4ppb) and lead (20.5ppb).
-------
I.I-OCE - I.I DkUonxIkM
I.I OCA . |.|.
- I J-OfeMoniMtaM (Toul)
IJ OCA
I.I.I-TCE - 1.1.1-TriAlorankcx
MW-01SCMW-01D
U-DCE01 660E HOE
1.2 DCA 210 VO
I.I-TCK HOP. 66IB
2IOOG
I.I-DCE 2101 190
I.I DCA 200 MO
I.I.ITCE 510 72.01
TCP. 200 120
j®r MONITORING WELL
Organic Concantntlons (ug/1) In
Monitoring Well Water Samplai
-------
Inorganic Concentration! (ug/1) In
Monitoring Well Water Simple!
-------
•£_v_Ai> . ^~~^t'^ **
TTTTTfa'—V~"llllJlli7~~lilli;iJlilllllllf(ill
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BOL o BclomOetecllon Limit
(2) = Dupllcil* Simple
•ff)- RESIDENTIAL WELL
Nickel Concentrations (ug/l) In
Residential Well Water Sample*
-------
12
C. Lagoon Contamination
Sludge and liquid samples were collected from the two RCRA-
regulated wastewater treatment lagoons. A total of 9 sludge
samples (including 1 duplicate), and 3 liquid samples (including
1 duplicate) were collected from the lagoons. The sampling
locations are shown in Figure 1-16. The samples were analyzed
for volatile organics and full TAL inorganics. In addition, one
composite sludge sample was collected from the lagoons and
analyzed for RCRA hazardous waste characterization.
C.I Sludge
Analytical results of the RCRA lagoon sludge samples indicated
the presence of nine volatile contaminants which include acetone,
methylene chloride, l,l-dichloroethane, 1,1,1-trichloroethane,
trichloroethene, tetrachloroethene, toluene, ethylbenzene, and
xylene. Acetone in particular was detected at elevated concen-
trations in eight of the nine samples. Most of the volatile
compounds were reported in sludge samples located adjacent to the
central dividing wall running lengthwise between the two
wastewater treatment lagoons. This may indicate a tendency on
the part of the contaminated sludge to settle out adjacent to the
dividing wall. The degreasing operations are the likely source
of these contaminants.
Sludge contaminated with arsenic, cadmium, chromium, copper,
lead, nickel, zinc, and cyanide was found in most of the samples
collected from the wastewater treatment lagoons. These
inorganics were reported with very high concentrations, where the
maximum concentrations were detected in the west lagoon except
for arsenic. Arsenic was detected with the maximum concentration
was in the east lagoon. The presence of these inorganics is
likely from the treatment of wastewater from the OEC
electroplating process. In addition, the lagoon sludge was
determined to be a characteristic hazardous waste based on its EP
toxicity (cadmium) and reactivity (cyanide). The lagoon sludge
is a listed RCRA hazardous waste (F006).
C.2 Liquid
Analytical results of the lagoon liquid samples indicated the
presence of methylene chloride and acetone. These contaminants
were detected in both wastewater treatment lagoons. Methylene
chloride and acetone were also detected in the lagoon sludge at
elevated concentrations. The occurrence of these organics may be
attributed to the discharge of spent solvents and bottom sludges
from the degreasing operations into the lagoons.
No inorganic contamination was detected in the lagoon liquid.
-------
• LAGOON SLUDGE SAMPLE
D LAGOON LIQUID SAMPLE
(All locations are approximate)
50
SCALE IN FEET
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATINQ COMPANY
FIGURE 1-16
LAGOON SAMPLING LOCATIONS
EBASCO SERVICES INCORPORATED
-------
13
D. Wetlands Contamination
Several studies of the contamination in the wetlands have been
conducted. In 1987, Weston collected sediment and surface water
samples from a 300 acre wetlands area south of the OEC facility
along Davy Creek. A total of 184 sediment samples and 7 surface
water samples were collected. The wetlands area under
investigation was subdivided into three areas: the grid area,
the Davy Creek up-stream area, and the Davy Creek down-stream.
The grid area consisted of 94 sediment samples obtained from 30
locations in a 250,000 square foot area south of the OEC
facility. The Davy Creek up-stream area occupied the east side
of the grid along Davy Creek. Forty-five sediment samples from
14 locations were collected along this 3/4 mile stretch along
Davy Creek. The Davy Creek down-stream area was defined as the
area between the grid and the confluence point of Davy Creek with
the Rock River. Forty-five sediment samples were collected from
16 locations west (down-stream) of the grid area. The 7 surface
water samples were collected from different locations within the
wetlands study area.
Selected sediment samples were analyzed for total Hazardous
Substance List (HSL) metals, full-scan HSL organics, hexavalent
chromium, total and reactive cyanide, EP toxicity (metals), and
total organic carbon. A maximum of four intervals (0 to 1, 1 to
2, 2 to 3, and 3 to 5 feet) were sampled at any given location.
Surface water samples were analyzed for total HSL metals, full-
scan HSL organics, hexavalent chromium, and total cyanide.
D.I Wetlands Grid Sediment
Analytical results indicated three volatile organic compounds
present in the sediment. These were acetone, methylene chloride,
and toluene. The highest concentrations reported were 4,000 g/kg
acetone, 250 g/kg methylene chloride (also detected in laboratory
blank), and 1,100 g/kg toluene.
The grid, which is located adjacent to OEC's discharge ditch, was
suspected to be a potential sink for contaminants. Sediment
samples collected from the central and upper-central sections of
the grid contained the highest concentrations of metals and
cyanide. The contaminants of primary concern in the grid
sediment were cadmium, chromium, copper, nickel, zinc, tin, and
cyanide. The 0 to 1 foot sampling interval yielded
concentrations of up to 3,600 mg/kg cadmium, 8,840 mg/kg
chromium, 3,550 mg/kg copper, 16,500 mg/kg nickel, 1,120 mg/kg
tin, 10,800 mg/kg zinc, and 1.120 total cyanide. These
contaminant concentrations exceeded those of the background
sample and the range of typical metal concentrations in natural
soils. Results also indicated that the concentrations of metals
and cyanide are at elevated levels at depths greater than three
feet. Isopleths of concentrations for cadmium, chromium, nickel,
-------
14
zinc, and cyanide for 0 to 1, l to 2 and 2 to 3 foot depth
intervals are illustrated in Figures 1-17 through 1-31 in the FS.
Isopleths for the above metals for the 0 to 1 foot interval are
attached. See Figures 1-17, 1-20, 1-23, 1-26, and 1-29.
Results of the 1987 Extent of contamination Study showed no EP
toxicity levels over the RCRA levels for metals. However the
April 1988 test results showed a large area within the wetland
exceeding RCRA EP toxicity levels for metals. Inorganic and
organic concentrations are shown in Tables 1-1 through 1-3 and
Table 5.
D.2 Upstream Area Sediments
Samples were collected through the first two feet of sediment in
the Davy Creek upstream area (Figure 1-32). The sediment did not
appear to be contaminated with metals or cyanide. The
concentration ranges shown in Tables 1-4 and 1-5 , can be
considered the background samples.
D.3 Down-Stream Area Sediments
The sediment samples collected immediately down-stream of the
sewage treatment plant's discharge area (Figure 1-32) had
elevated concentrations of metals and Cyanide. Cadmium (272
mg/kg), chromium (1,370 mg/kg), copper (714 mg/kg), and nickel
(987 mg/kg) were detected in the 1 to 2 foot sampling interval.
Also, 11.1 mg/kg of cyanide was reported. The remaining
downstream Davy Creek sediment samples also had elevated levels
of metals contaminants.
D.4 Surface Water
The organic analytical results indicated that surface water in
the wetlands does not appear to contain any significant
concentrations of contaminants.
Surface water samples in the wetlands did not contain metal
contaminants, with the exception of zinc, associated with OEC
processes. Zinc concentrations ranged from 11 to 478 ppb, the
latter concentration being from a sample collected at the OEC
discharge point. The field blank also detected zinc (13 ppb)
which may indicate that the sample bottles or the preservative
was slightly contaminated with zinc. Cyanide concentrations in
all the water samples were below detection limits.
Chemicals of concern identified in the wetlands which may
contribute to chronic and or acute toxicity to aquatic organisms
living in the wetlands and Davy Creek include cadmium, chromium,
nickel, copper, lead, zinc and cyanide. In addition, cadmium and
copper may bioaccumulate to varying degrees in organisms within
in the wetlands and Davy Creek ecosystems.
-------
0 SEDIMENT SAMPLE LOCATIONS
SURFACE WATER SAMPLE LOCATIONS
ENVIRONMENTAL PROTECTION AOENCY
OCONOUOWOC d.ECTTK>n.ATIN3 COMPANY
flgur.
Cadmium Concentration Isopleln*
(mg/kg) lor Grid Area Sedimen
0-1 ft Depth Interval
Source: Weston (1987)
-------
SAMPLE LOCATIONS
SURFACE WATER SAMPLE LOCATIONS
SCAU IN FEET
Source: Weslon (1987)
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATINQ COMPANY
Fljur. I JO
Chromium Concentration Isoplelhs
(mg/kg) lor Grid Are* Sediment
O-l It Depth Interval
CflASCO SEHVICE5 INCORPOHATEO
-------
Q SEDIMENT SAMPLE LOCATIONS
A SURFACE WATER SAMPLE LOCATIONS
SCALE IN FEET
Sow 'Veslon (1987)
ENVIRONMENTAL PROTECTION AQENCY
OCONOMOWOC ElECTHOn.ATINO COMRWY
Figure f-2J
Nickel Concentration lioplelhi
(mg/lig) lor Grid Area Sediment
0-1 n tJeplh ' --!rvjl
A:^:() SFHVIKI.'
-------
0 SEDIMENT SAMPLE LOCATIONS
A SURFACE WATER SAMPLE LOCATIONS
SCALE IN FEET
Source: We;lon(l9a?)
ENVIRONMENTAL PROTECTION AOENCY
OCONOUOWOC EiECTBOPLAIINO COMWMV
Flgur* I -It
Zinc Concentration Isoplelnt
(mg/kg) ior Grid Area Sediment
0-1 II Depth Interval
FflASCO SEMVICCS INCORPORATED
-------
GJ SEDIMENT SAMPLE LOCATIONS
SURFACE WATER SAMPLE LOCATIONS
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTnOPLATINO COUf*NY
Flgia. I It
Cyanide Concenlnllon lioplelht
(mg/lcg) (or Grid Are* Sediment
O-1 It Depth Interval
Source: Weslon (1987)
-------
Table 1-1: Inorganic Concentrations (mg/kg) in Davy Creek
Sediment Downstream of OEC Facility -- 0 to 1 Foot
Depth Interval
Analyte
Cadmium 383
Chromium (Total) 4,720
Chromium (Cr*6) NA
Copper 2,760
Lead 284
Nickel 2,760
Tin NA
Zinc 4,230
Cyanide (Total) 39.0
Cyanide (Reactive)- NA
(1) Results of FIT Collected
(2) Results of TAT Collected
13.7 10.4
130 37.6
NA NA
26.8 58
6.4 6.0
69.2 40.1
NA NA
75.6 89.5
6.1
NA NA
Sediment Samples
Sediment Samples
(3) Background Sample Collected Approximately :
NA = No Analysis Performed
Sample
7+500(2)
149
545
4.6
249
8.8
591
<14
318
3.6
<0.2
10+000(2) 12+50D(2) Background
22
94
<2
90
17
98
<26
139
1.3
NA
20
48
NA
97
.1
35
91
NA
NA
(Ecology & Environment, 1988)
(Weston, 1987)
3700 Feet Upstream of Site
<2.7
14
NA
18
9.6
12
64
47
<0.2
NA
-------
Table 1-2: Inorganic Concentrations (mg/kg) in Davy Creek
Sediment Downstream of OEC Facility -- 1-2 Feet
Depth Interval
Analvte
Cadmium
Chromium (Total)
Chromium (Cr*6)
Copper
Lead
Nickel
Tin
Zinc
Cyanide
Cyanide (Total)
11.1
72.4
NA
40.7
13.4
48.2
NA
90.4
1.7
NA
S2AH)
121
379
NA
171
25
518
NA
320
90.4
NA
NA
Sample
7+500(2)
272
1,370
NA
714
29
987
86
1,190
11.05
<0.2
10+OOPm 12+500(2) Background
21
97
NA
65
11
78
<26
82
NA
NA
(1)
(2)
(3)
NA =
Results of FIT Collected Sediment Samples (Ecology & Environment, 1988)
Results of TAT Collected Sediment Samples (Weston, 1987)
Background Sample Collected Approximately 3,700 Feet Upstream of Site
No Analysis Performed
<3.6
<3.6
<2
90
<3.6
4.3
7.3
<0.71
NA
<2.7
14
NA
18
9.6
12
64
47
<0.2
NA
-------
Table 1-3: Organic Concentration Ug/kg) in Davy Creek Sediment
Samples Downstream From OEC Facility
Compound
Acetone
1,1-Dichloroethene
1,1-Dichloroethane
1,2-Dichloroethene (Total)
2-Butanone (MEK)
1,1,1-Trichloroethane
Trichloroethene
4-methyl-2-pentanone
Toluene
Chlorobenzene
S1A
SIB
Sample*
S2A
S2B
S3A
S3B
11
18
14
110
20
17
A = 0-1 Foot Depth
B = 1-2 Foot Depth
FIT Collected Sediment Samples (Ecology & Environment, 1988)
-------
Table 1-4: Inorganic Concentrations (mg/kg) in Davy Creek
Sediment Upstream of DEC Facility -- 0 to 1 Foot Depth
Interval
Analyte
Cadmium
Chromium
Chromium
Copper
Lead
Nickel
Tin
Zinc
Cyanide
Cyanide
(Total)
(CO
(Total)
(Reactive)
7+50M
9.5
29
<2
47
<6.3
78
<25
91
<1.2
NA
Sample0'
10+OOH
10
125
NA
39
7.5
69
74
NA
NA
12+50M
5.9
26
<2
26
14
49
<21
40
<1.1
NA
Background^)
<2.7
14
NA
18
9.6
12
64
47
<0.2
NA
NA = No Analysis Performed
(1) TAT Collected Sediment Samples (Weston, 1987)
(2) Background Sample Collected Approximately 3,700 Feet Upstream of Site
-------
Interval
Analyte
Cadmium
Chromium
Chromium
Copper
Lead
Nickel
Tin
Zinc
Cyanide
Cyanide
(Total)
(Total)
(Reactive)
7+50H
3.9
11
NA
12
4
12
28
NA
NA
NA .
(1)
(2)
Sample0'
10+OOH 12+50M
<3.2
6.9
<2
15
4.3
14
<13
29
NA
NA
<4.6
15
NA
21
16
17
<19
65
NA
NA
<2.7
14
NA
18
9.6
12
64
47
<0.2
NA
No Analysis Performed
TAT Collected Sediment Samples (Weston, 1987)
Background Sample Collected Approximately 3,700 Feet Upstream of Site
-------
PLANT DISCHARGE '\
MUNICIPAL SCWAOC THEATUENT PLANT
LlNCflLM
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATING COMPANY
FIGURE 1-32
DAVY CREEK SEDIMENT
SAMPLES LOCATIONS
EBASCO SERVICES INCOHPC :"D
-------
15
The contamination of the wetlands to the south of the OEC
Facility is a hazard to the environment.
The toxicity tests revealed a few samples to be acutely toxic to
fathead minnows. In addition, one sample was chronically toxic
to the algae. The chemical or precise combination of chemicals
which are causing the toxicity are unknown. Each chemical or
metal in our analysis can be toxic when presented in appropriate
concentrations. They can also act as synergists or antagonists
when presented with other metals. In this case the levels or
combination of chemicals and metals has exceeded the minimum
which is toxic to the two species tested.
The toxicity data collected on fathead minnows and algae showed
conclusively that the contamination in the wetland is toxic.
E. Contaminant Fate and Transport
The fate and transport of chemical contaminants is of major
importance in the evaluation and quantification of the risks
resulting from site contamination. The relevant environmental
fate data for the chemical contaminants associated with the OEC
site are presented. These chemicals were grouped into two
generalized classes sharing similar characteristics, volatile
organics and inorganics.
E.I. Volatile Organics
The volatile organic compounds that were detected or exceeded the
MCLs or PALs were grouped into chlorinated and non-chlorinated
type compounds.
E.I.a Chlorinated Compounds
The chlorinated compounds considered to be indicator chemicals at
the OEC site are methylene chloride, 1,1-dichloroethene, 1,1-
dichloroethane, 1,2-dichloroethene (total), 1,2-dichloroethane,
1,1,1-trichloroethane, trichloroethene, and tetrachloroethene.
Due to the high water solubility of these compounds, groundwater
transport of chlorinated volatile organic compounds will be a
principal environmental fate/transport mechanism at the OEC site.
Volatilization will also be a major environmental fate/transport
mechanism at the air-soil-water interface matrices for
chlorinated compounds at the site. Photolysis, oxidation,
hydrolysis, sorption, bioaccumulation,
biodegradation/biotransformation, and persistence are not
significant environmental fate processes.
-------
16
E.l.b Non-chlorinated Compounds
The non-chlorinated indicator chemicals at the OEC site are
acetone, toluene, ethylbenzene, and xylene. Water solubility and
volatilization are the principal environmental fate/transport
mechanisms at the OEC site. For non-ketone volatile organic
compounds (i.e., toluene, ethylbenzene, and xylene), adsorption
will be a principal fate/transport mechanism. But for ketone
volatile compounds (i.e., acetone) adsorption will not be a
principle fate/transport mechanism. Photolysis, oxidation,
bioaccumulation, biodegradation/biotransformation, and
persistence are not significant environmental fate processes.
E.2 Inorganics
The inorganic indicator chemicals at the OEC site are arsenic,
cadmium, chromium, copper, lead, nickel, zinc, and cyanide. The
principal environmental fate/transport mechanisms for these
inorganic contaminants are sorption, complexation, and
precipitation/coprecipitation.
Arsenic, cadmium, copper, lead, nickel, and zinc are all adsorbed
by a variety of constituents present in the environment. These
include hydrous iron, calcium oxides, metal oxides, aluminum,
clays, and organic matter. Two elements which are not
significantly affected by the sorption mechanisms are chromium
and cyanide.
All the inorganic analytes of concern form organic and inorganic
complexes in the environment. These complexes, along with
sorption, can aid in the precipitation/coprecipitation of the
contaminants and therefore contribute to the persistence of these
inorganics. Arsenic is the only element of concern which is not
significantly affected by the precipitation/coprecipitation
mechanism.
Bioaccumulation is not significant for arsenic, chromium, lead,
zinc, or cyanide. However, cadmium and copper are bioaccumulated
to varying degrees in the environment. Volatilization and
photolysis are also not important fate/transport mechanisms for
the majority of the inorganic contaminants of concern at the OEC
site. Cyanide, however, is a highly volatile element and could
potentially enter the environment as vapor. Copper and lead have
been shown to be susceptible to sunlight.
In summary all of the inorganic contaminants except cyanide are
persistent in the environment. Cyanide is very mobile and easily
biodegraded, therefore, it is not very persistent.
-------
17
VI. Summary of Site Risks
The exposures and risks to nearby residents or workers, and to
the environment were evaluated. This assessment is site specific
and provides baseline evaluation of the site under the assumption
of no remedial actions and that future development of the site
could occur. The baseline risk assessment followed the guidance
in the Superfund Public Health Evaluation Manual (1986). At this
time, no final exposure levels have been calculated for the
wetlands south of the OEC facility. However, a preliminary
toxicity investigation in the wetlands was conducted by the USEPA
to determine if the contaminated sediments from the wetlands are
toxic to aquatic organisms. The results of all investigations
relating to the wetlands are included in the Administrative
Record file.
A. Human Health Risk
The public health evaluation for the OEC site was organized
around several areas of the site which are sources of potential
human exposure to contamination. See tables 6-1 and 6-2 for the
media of concern and the chemicals of concern for the following
areas:
1. Parking Lot Area - the unfenced northern corner of the
site, plus the paved area and driveway on the eastern
side of the site;
2. Decontamination Area - the fenced portion of the
northern corner of the site;
3. Fill Area - the unfenced area southeast of the OEC
facility;
4. Lowlands Area - the unfenced swampy area south of the
fill area;
5. Lagoon Area - the fenced area surrounding the lagoons
and wastewater treatment buildings, and adjacent to the
western walls of the OEC facility; and
6. Lagoons - the area of.the wastewater treatment lagoons
themselves.
Nine possible human exposure scenarios associated with these
sources of site contamination were identified and evaluated.
The first five were evaluated for current use and the last four
were evaluated for future use. These are:
1. Dermal contact, ingestion, and inhalation of soil by
children playing in the ballpark/playground area south-
east of the site.
-------
TABLE 6-1
SUMMARY OF ORGANIC CONTAMINANTS SELECTED
AS INDICATOR CHEMICALS BY MEDIUM
Contaminant
Acetone
Methylene Chloride
1,1-Dichloroethene
1 1_rV/*HI/-*r«'>rt **••* — -
1 ,2-Oichloroethene (total)
1 ,2-Dichloroethane
1,1,1-Trichloroethane
Trichloroethene
Tetrachloroethene
Toluene
Ethylbenzene
Xylene
Vinyl Chloride
Soil
0
O
—
A
O
—
X
X
O
X
—
O
—
Lagoon
Sludge
X
X
—
X
—
—
X
X
X
X
X
X
—
Groundwater
0
O
V
X
O
X
X
X
—
—
—
—
0
Lagoon
Liquid
X
X
..._
—
—
—
—
—
—
—
—
—
—
X Contaminant is selected as indicator chemical.
O Contaminant is present in the medium but not selected as indicator chemical.
— Contaminant is not present in the medium.
-------
TABLE 6-2
SUMMARY OF INORGANIC CONTAMINANTS SELECTED
AS INDICATOR CHEMICALS BY MEDIUM
Contaminant
Arsenic
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
Cyanide
Soil
X
X
X
X
X
X
X
X
Lagoon
Sludge
X
X
X
X
X
X
X
X
Lagoon
Groundwater Liquid
— —
x
—
— _
— o
X
— o
X
X Contaminant is selected as indicator chemical.
O Contaminant is present in the medium but not selected as indicator chemical.
— Contaminant is not present in the medium.
-------
18
2. Dermal contact, ingestion and inhalation of soil, and
inhalation of volatiles emanating from soil, by
children accessing the on-site fill and lowlands areas.
3. Inhalation of resuspended contaminated soil by workers
and children accessing the parking lot area.
4. Inhalation of resuspended lagoon area soil by a worker
who frequents the lagoon area (i.e., the wastewater
treatment engineer).
5. Inhalation of resuspended lagoon sludge, and volatiles
emanating from lagoon sludge during dry periods by the
wastewater treatment engineer.
6. Inhalation of resuspended lagoon sludge during dry
periods by residents adjacent to the site.
7. Ingestion of garden vegetables grown in windblown soil
from the site.
8. Dermal contact, ingestion, and inhalation of on-site
fill area soil by workers during future
excavation/construction.
9. Future ingestion of shallow on-site groundwater
migrating to residential wells in the Upper Dolomite
aquifer.
Models and parameter assumptions were developed and used to
calculate chronic daily intakes of indicator chemicals from the
exposure pathways associated with these scenarios. Two exposure
cases were evaluated for each pathway, one representing the best-
estimate (geometric mean) of exposures to indicator chemicals,
and one representing a set of conditions which would result in a
reasonable maximum exposure level.
A.I Toxicity Assessment Summary
Cancer potency factors (CPFs) have been developed by U.S. EPA's
Carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with exposure to potentially
carcinogenic chemicals. CPFs, which are expressed in units of
(mg/kg-day)'1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects
the conservative estimate of the risks calculated from the CPF.
Use of this approach makes underestimation of the actual cancer
risk highly unlikely. Cancer potency factors are derived from
the results of human epidemiological studies or chronic animal
-------
19
bioassays to which animal-to-human extrapolation and uncertainty
factors have been applied. See Table 6-28.
Reference doses (RfDs) have been developed by U.S. EPA for
indicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals.
Estimated intakes of chemicals from environmental media(e.g., the
amount of a chemical ingested from contaminated drinking water)
can be compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors
assure that the RfDs will not underestimate the potential for
adverse non carcinogenic effects to occur.
Excess lifetime cancer risks are determined by multiplying the
intake level with the cancer potency factor. These risks are
probabilities that are generally expressed in scientific notation
(e.g., IxlO"6 or 1E-6). An excess lifetime cancer risk of lxlO~6
indicates that, as a plausible upper bound, an individual has a
one in a million chance of developing cancer as a result of
site-related exposure to a carcinogen over a 70-year lifetime
under the specific conditions at a site.
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminants reference dose). By adding the HQs for all
contaminants within a medium or across all media to which a given
population may reasonably exposed, the Hazard Index (HI) can be
generated. The HI provides a useful reference point for gauging
the potential significance of multiple contaminant exposures
within a single or across media.
Excess cancer risk estimates were calculated for exposures to
carcinogenic indicator chemicals by summing the product of the
chronic daily intakes (GDI) and cancer potency factor for all
carcinogenic indicator chemicals and intake routes for a given
human receptor. Hazard indices.were calculated for exposures to
non-carcinogenic indicator chemicals by summing the ratios of
GDIs to acceptable daily intakes (reference doses) for all
chemicals and intake routes for a given human receptor.
B. Risk Summary
The risk assessment results show that risk estimates for both
carcinogens and non-carcinogens are within EPA's target risk
ranges (10"~4 to 10~6 excess cancer risk and hazard index <1.0)
for all best-estimate exposure scenarios. With the exception of
-------
27
TABLE 6-28
TOXICITY PARAMETERS USED IN THE RISK ASSESSMENT
Acceptable Intake(a)
(mg/kg/day)
Chemical
Acetone
Ammonia
Arsenic
Cadmium
Oral
1.00E-01
9.70E-01
1.0E-03
1.03E-03(food)
5.0E-04 (water)
Inhalation
NO
0.36 mg/m3
ND
ND
Source(b)
HEA
RID
—
RfO
Cancer Potency Factor
(mg/kg/day)(-1)
Oral
NA
1.8E+00
ND
Inhalation
NA
5.0E+01
6.1E+00
Source
—
HEA
HEA
EPA
Weight of
Evidence(c)
—
A
B1
Chromium
Hexavalent (VI)
Trivalent (III)
Copper
Cyanide
1.1-Dichloroethane
1,1-Dichloroethene
1,2-Dichloroethane
Ethylbenzene
Lead
Methylene Chloride
Nickel
Toluene
1,1,1 -Trichloroethane
Trichloroethene
Total Xylenes
Zinc
5.0E-3
1.0E+0
3.7E-02(d)
2.0E-02
1 .OE-01
9.0E-03
NA
1. OE-01
1.4E-03
6.0E-02
2.0E-02
3.0E-01
9.0E-02
NA
2.0E+00
2.0E-01
ND
ND
ND
ND
1. OE-01
ND
NA
ND
ND
NA
ND
1.0E+00
3.0E-01
NA
4.0E-01
NA
RID
RID
HEA
RID
RID
RID
—
RID
MCL
RID
RfD
RID
RfD
—
RfD
RfD
NA
NA
NA
NA
9.1E-02
6.0E-01
9.1E-02
NA
ND
7.5E-03
ND
NA
NA
1.1E-02
NA
NA
4.1E+01
NA
NA
NA
ND
1.2E+00
9.1E-02
NA
ND
1.4E-02
8.4E-01
NA
NA
1.3E-02
NA
NA
—
—
—
—
HEA
HEA
HEA
—
—
HEA
HEA
—
—
. HEA
—
—
—
—
—
—
B2
C
B2
—
—
B2
A
—
—
B2
—
—
-------
27
TABLE 6-28 (Cont'd.)
TOXICITY PARAMETERS USED IN THE RISK ASSESSMENT
NOTE:
a. Chronic (AIC): Acceptable Chronic Int, USEPA Integrated Risk Information System
CAG * USEPA Carcinogen Assessment Group
c. Alphanumerics represent EPA Weight of Evidence classifications, which are defined as follows:
Group A - Human Carcinogen. Sufficient evidence from epidemiologic studies to support a casual association
between exposure and cancer.
Group B1 - Probably-Human Carcinogen. Limited evidence of carcinogenicity in humans from epidemiologic studies.
Group B2 - Probable Human Carcinogen. Sufficient evidence of carcinogenicity in animals; inadequate evidence of
carcinogenicity in humans.
Group C - Possible Human Carcinogen. Limited evidence of carcinogenicity in laboratory animals.
d. Converted from standard of 1.3 mg/l by assuming a 70kg adult drinking 2 liters/day of water.
* * - For those compounds where inhalation criteria are not available, the oral criteria will be used as the cancer
potency factor and/or AIC (RfD) in evaluating potential risks posed by these compounds.
NO: Not Determined
NA: Not Applicable or Not Available
-------
20
the future groundwater ingestion limiting case (contaminated
groundwater migrating from the site to the residential wells),
excess cancer risk estimates are within target risk ranges for
all other reasonable maximum exposure scenarios. The results
indicate an excess of target risk ranges for these potential
exposure scenarios at the OEC site:
1. A non-carcinogen hazard index of 1.81 was calculated
for the plausible maximum exposure to contaminated soil
by a child continuously accessing the fill and lowlands
areas on the southeast side of the site. Over 75
percent of this risk is attributable to exposures to
lead and cadmium through direct contact and incidental
ingestion pathways.
2. A non-carcinogen hazard index of 3.66 was calculated
for the plausible maximum exposure to contaminated soil
by a worker involved in possible future development of
the fill area. Over 75 percent of this risk is
attributable to exposures to lead and cadmium through
incidental ingestion pathways.
3. An excess cancer risk of 3.53E-03 and a non-carcinogen
hazard index of 3.2 were calculated for the possible
future groundwater ingestion pathway. This exposure
scenario was evaluated for a limiting case, where it
was assumed that for 50 years an individual drinks 2
liters per day of groundwater having indicator chemical
concentrations equal to the maximum concentrations
detected in the shallow on-site monitoring wells.
One or more residential wells downgradient from OEC showed
elevated levels of zinc, cadmium, lead and nickel. No federal
MCLs were exceed in these analyses. The Wisconsin PAL for
cadmium was exceeded at one well. The levels of risk estimated
for the two fill/lowlands area exposure scenarios are a result of
high lead and cadmium concentrations in fill and laboratory area
soil. The exposure pathways of concern are dermal contact and
incidental ingestion. Volatile organic contaminants in the soil
are not a risk to human health.
C. Ecological Risk Assessment
The major areas of environmental concern associated with the OEC
site are Davy Creek and the adjacent wetlands ares. Several
studies conducted over the years by WDNR and EPA have
demonstrated that the Davy Creek area and wetlands have been
impacted by the electroplating wastes from the OEC site. In
particular, the investigations have shown that the wetlands are
contaminated with elevated levels of cadmium, chromium, nickel,
copper, lead nickel, tin, zinc, and cyanide. The contamination
of these environmentally-sensitive areas is largely a result of
-------
21
the direct channelling of highly contaminated, untreated
wastewater in the wetlands area by the OEC facility. There is
also evidence that surface run-off from the site during heavy
precipitation events or snow melts may have led to contamination
being transported to these areas.
During the Remedial Investigation, a number of samples were taken
from the wetlands and Davy Creek area. Sediment and surface
water samples were taken in areas upstream, down-stream and
adjacent to the treatment plant's discharge area. The results of
that sampling are presented Table 0-1 through 1-5. It should be
noted however, that final exposure levels have not been
calculated for these areas at this time. During remedial design
and action phases, additional environmental studies will be
conducted to further define the extent of contamination in Davy
Creek and the wetlands and the extent of a toxicity due to the
contamination. A product of those studies will be the
development of final exposure levels for the contaminated
sediment in the wetlands and Davy Creek. The EPA and WDNR
believe that the RI information presented is sufficient to
support the EPA's and WDNR's decisions to take the interim action
of removing the more highly contaminated sediments in order to
prevent further degradation of the wetland and to achieve
significant risk reduction. It is unknown in the wetland area
whether endangered species inhabit the contaminated area.
C.I Environmental Risks
The contamination of the wetlands to the south of the OEC
Facility has been proven to be a significant hazard to the
environment. The sediments from several points exceed what is
accepted as highly toxic.
Wetland sediments have a large capacity for binding heavy metals
and not allowing these metals to become available to the environ-
ment and its biota. In the present case, the high levels of
metal contamination have been partially bound to the sediments
but the high levels of contamination have overwhelmed the
capacity of the wetlands and toxic metals are available.
The toxicity tests revealed a few samples to be acutely toxic to
fathead minnows. In addition, one sample was chronically toxic
to the algae. The chemical or precise combination of chemicals
which are causing the toxicity are unknown. Each chemical or
metal in our analysis can be toxic when presented in appropriate
concentrations. They can also act as synergists or antagonists
when presented with other metals. In this case the levels or
combination of chemicals and metals has exceeded the minimum
which is toxic to the two species tested.
The.toxicity data collected on fathead minnows and algae showed
conclusively that the contamination in the wetland is toxic. The
-------
22
use of two species one fish and one plant has demonstrated that
the contamination of chemicals and metals on site is toxic to
both species.
C. Assessment of Human Health and Environmental Risks Presented
by the Site
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response actions
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or, the environment.
VII. Description of Alternatives
The goals of the OEC remedial actions are: to protect human
health from any current and future risk; control the sources of
groundwater contamination to protect human health; and to protect
the environment by removing contamination currently causing
environmental harm. The following is the list of alternatives by
operable units followed by a detailed description of the
alternatives.
A. No Action
B. Minimal Action
C. Operable Unit 1: Lagoons/Final Action
LI - Contaminated Water - Pumping/Ion Exchange/Carbon
Adsorption Sludges/Excavation/Off-Site Treatment
and Disposal
D. Operable Unit 2: Contaminated Soil/Final Action
SI - Excavation/Off-Site Treatment and Disposal
S2 - Capping(RCRA)
E. Operable Unit 3: Groundwater/Final Action
GW1 - Subsurface Drains/Jon Exchange/Air Stripping/Carbon
Adsorption/Chemical Oxidation (If Necessary)
GW2 - Groundwater Pumping/Ion Exchange/Air
Stripping/Carbon Adsorption/Chemical Oxidation
(If Necessary)
-------
23
F. Operable Unit 4: Davy Creek and Wetlands/Interim Action
DW1 - Excavation/Off-site Treatment and Disposal
DW2 - Excavation/On-site Stabilization/Off-site Disposal
G. Manufacturing Building and Subsurface Soils
Data is insufficient at this time to recommend
alternatives for the building and subsurface soils.
Additional investigations will be conducted in this area.
A. No Action Alternative
CERCLA requires that the "no action" alternative be considered at
every site. Under this alternative, EPA would take no further
action to remedy the contamination. However, long-term
monitoring of the site of all four operable units would be
necessary to monitor contaminant migration. A ground water
monitoring program would be performed for the first three
operable units to observe possible changes in contaminant
levels. The wetlands would also be monitored.
Because this alternative would result in contaminants remaining
on-site above risk based levels, CERCLA requires that the site be
reviewed every five years. If justified by the review, remedial
actions would be implemented at the time to remove or treat the
wastes.
The present worth cost of this alternative is $322,992.
B. Minimal Action
The Minimal Action alternative would also be used for all four
operable units and would include fencing and sign posting in
addition to long-term monitoring of the groundwater, surface
water and sediments.
A chain link security fence would be installed around the
perimeter of the site to prevent access. Presently, a fence
exists around the lagoons and wastewater treatment facility.
However, additional fencing is required around the remainder of
the site. The length of proposed fencing is approximately 1200
linear feet including two 20 foot wide double swinging gates to
provide access to the OEC facility. In addition to the security
fence, warning signs would be posted along the fence and at the
entrance gates. Long-term monitoring of the site would consist of
checking the condition of the fence; and sampling and analysis of
surface water, groundwater and sediment in order to monitor
contaminant migration. The monitoring program would be the same
as the one proposed in the No Action alternative. This
alternative would only be chosen in the event that the active
-------
24
remedial alternatives were found to be impracticable by the
agencies.
The present worth cost for this alternative is $348,192.
C. Alternative LI - RCRA-regulated Lagoons
The RCRA lagoons contain approximately 72,000 gallons of organic
contaminated water. Under this remedial alternative, the water
would be pumped from the two lagoons to an equalization tank.
From this tank the surface water would be transferred to the
groundwater treatment system. This treatment system will
include an ion exchange unit or metal precipitation unit for
metal removal; and an air stripper, vapor phase carbon adsorption
unit or a liquid phase carbon adsorption unit for organic
contaminant removal. The treated water would then be discharged
directly to the Davy Creek/Wetlands area, in compliance with the
WPDES discharge requirements.
After removing the contaminated lagoon water, the metal
hydroxide sludge (which contains F006 hazardous waste) at the
bottom of the lagoons ("400 yd3) would be removed using a
backhoe.
The contaminated soil surrounding the lagoons ("250 yd3) would
also be excavated with the backhoe. The soil, which contains F006
waste, would be excavated to background levels in compliance with
the WDNR clean closure requirements. Both the sludge and soil
would then be loaded into trucks and transported off-site to a
RCRA permitted treatment and disposal facility, where they will
be stabilized in accordance with RCRA LDR requirements. All
excavated areas will be backfilled using clean fill material and
the area would be graded and revegetated.
The total present worth cost for this alternative is $490,302.
C. Operable Unit 2 - Contaminated Soil
C.I Alternative SI
Contaminated soils not associated with the wastewater treatment
lagoons (-1,000 yd3), also considered to be a hazardous waste
containing a F006 waste, would be excavated to established
cleanup levels (based on results of the risk assessment, See
Table 2-1), loaded onto trucks and transported to a RCRA
permitted treatment and disposal (TSD) facility . At the TSD
facility the wastes will be stabilized in accordance with RCRA
LOR requirements prior to land disposal. All excavations would be
backfilled with clean fill material, graded, and vegetated. See
Figure 4-1.
The present worth cost for this alternative is $258,667.
-------
TABLE 2-1
SOIL CLEANUP LEVELS FOR THE
OCONOMOWOC ELECTROPLATING SITE
CARCINOGENS:
CARCINOGENIC
PARAMETER
ARSENIC
1,1-DICHLOROETHANE
TRICHLOROETHENE
FILL |
SOIL C |
(MAX) |
MG/KG |
I
47.0 |
0.070 |
0.800 |
NONCARCIKCGESS:
NONCARCINOGENIC
PARAMETER
ARSENIC
LEAD
CADMIUM
NICKEL
COPPER
CHROMIUM
ZINC
CYANIDE '
1,1-DICHLOROETHANE
TOLUENE
1,1,1-TRICHLOROETHANE
FILL
SOIL C
(MAX)
MG/KG
... .
47.0
300.0
500.0
2500.0
1500.0
1200.0
4500.0
90.0
0.070
0.075
0.210
-------
m .j^..__JH_ _fifl
m u m ^
• • • E
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATING COMPANY
CONTAMINATED SOIL TO BE
EXCAVATED
EBASCO SERVICES INCORPORATED
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25
D.2 S2 - Capping (RCRA)
This remedial alternative would consist of capping the
contaminated areas. A multi-layered cap which complies with RCRA
closure requirements would be placed over the site. See Figure
4-2 and 4-3. The area to be capped would include the
fill/lowlands and those areas determined to be contaminated east
of the facility. This area would be approximately 1.5 acres and
would be constructed as follows (from bottom to top):
o 2-foot clay layer (permeability, 10~7 cm/sec)
o 40 mil synthetic membrane (High Density Polyethylene)
o 1-foot sand layer — act as drainage layer
o Geotextile — polypropylene cloth to allow filtration
of leachate into sand layer
o 2-foot soil layer — for vegetation
o Vegetation — to prevent erosion
Post-closure use of the property would also be restricted, as
necessary, to prevent damage of the cap. Post-closure care and
ground water monitoring, in accordance with RCRA and WDNR
hazardous waste regulations, would also be implemented.
The present worth cost for this alternative is $1,108,793
E. Operable Unit 3 - Groundwater
E.I Alternative GW-1
This remedial alternative involves intercepting the contaminated
groundwater in a subsurface drainage system and treating it on-
site to reduce the contaminant levels. See Figure 4-4.
An approximately 500 foot long subsurface drainage system would
be installed south of the waste, treatment lagoons and the
lowlands area. The trench would be approximately 15 feet deep and
approximately 4 feet wide. The captured groundwater would be
pumped to an on-site treatment system which would include ion
exchange for metal and possible cyanide removal; and air
stripping and carbon adsorption for organic contaminant removal.
A alkaline chlorination (chemical oxidation) system will be
utilized for the treatment of cyanide if a treatability study
indicates that ion exchange is ineffective in removing the
contaminant from the groundwater. The groundwater would be
treated to meet the WPDES discharge standards and then discharged
-------
ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATINQ COMPANY
CONTAMINATED SOIL TO BE
CONSOUDATED UNDER RCRA CAP
EBASCO SERVICES INCORPORATED
-------
••-
-------
ENVIRONMENTAL PROTECTION AGENCY
SUBSURFACE TRENCH
OCONOMOWOC ELECTROPLATING COMPANY
SUBSURFACE DRAINAGE TRENCH
LOCATION
EBASCO SERVICES INCORPORATED
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26
to the Davy Creek/Wetlands area. Air emissions from the air
stripping tower would meet all WDNR requirements in NR 400 -
499, Wisconsin Administrative Code. The resultant ion exchange
resin from this treatment process would be properly disposed off-
site at a RCRA permitted landfill because it will contain an
F006 waste. It will be determined whether or not the spent carbon
requires disposal in a RCRA permitted landfill.
Figures 4-5 and 4-6 show block diagrams of the proposed treatment
process utilizing ion exchange and chemical oxidation,
respectively.
Action-specific ARARs which are applicable for the site pertain
to the construction of the subsurface drainage system and
treatment process, the treatment and subsequent disposal of the
treated groundwater, and the management of treatment residuals.
The groundwater would be treated to surface water quality
standards for organic and inorganic contaminants before being
discharged to the Davy Creek/wetlands area. The discharges from
the air stripper will meet the requirements of state code NR
400-499.
Alternative GW1 would consist of developing a groundwater
extraction system, analysis, design and implementation of an air
stripping, carbon adsorption and ion exchange. For costing
purposes the required time for complete remediation of the
unconsolidated unit aquifer is estimated to be 30 years. However,
the actual remediation time will likely be less than 30 years and
groundwater monitoring will be performed for the duration of the
treatment process to determine the effectiveness of the system.
This remedial alternative would also include semi-monthly
sampling of influent and effluent to confirm the effectiveness of
the treatment process. Process parameters are monitored as
required using instrumentation installed in the system.
The capital costs and O&M costs for this alternative with and
without chemical oxidation are $1,048,220, $1,223,660 and
$131,158, $143,765 respectively. The present worth cost for this
alternative with and without chemical oxidation is $3,081,130 and
$3,450,370 respectively.
E.2 Alternative GW2
This remedial alternative includes using extraction wells to
remove contaminated groundwater and treating it to reduce the
contaminant levels. See Figure 4-7.
Five groundwater recovery wells would be installed and equipped
with pumps south of the lagoons and fill/lowlands area.
Recovered groundwater would be pumped to an on-site treatment
plant through a header pipe system. Treatment would include
filtration, ion exchange, air stripping and carbon absorption. An
-------
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ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATING COMPANY
FIGURE 4-5
SCHEMATIC OF TREATMENT SYSTEM
FOR ALTERNATIVE GW1 AND GW2
USING ION EXCHANGF
EBASCO SERVICES INCORPC
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-------
n;i r.i
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ENVIRONMENTAL PROTECTION AGCNCY
OCONOMOWOC ELECTROPLATING COMPANY
FIGURE 4-6
SCHEMATIC OF TREATMENT SYSTEM
FOR ALTERNATIVES GW1 AND GW2
USING CHEMICAL OXIDATION
EBASCO SERVICES INCORPORATED
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ENVIRONMENTAL PROTECTION AGENCY
OCONOMOWOC ELECTROPLATING COMPANY
FIGURE 4-7
PUMPING WELL LOCATIONS
EBASCO SERVICES INCORPORATED
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27
alkaline chlorination (chemical oxidation) system will be
utilized for treatment of cyanide if a treatability study
determines that ion exchange will be ineffective in removing
cyanide from the groundwater. This treatment train is explained
in detail in Alternative GW1. Treated groundwater would be
discharged to the wetlands. Actual discharge limits will be
determined by WPDES requirements and considerations. The
resultant ion exchange resin from this treatment process would be
properly disposed off-site at a RCRA permitted landfill because
it will contain an F006 waste. It will be determined whether or
not the spent carbon requires disposal in a RCRA permitted
landfill. All air emissions will comply with WDNR requirements
in NR400 - 499, WAC.
Figures 4-5 and 4-6 show block diagrams of the proposed treatment
processes utilizing ion exchange and chemical oxidation/
respectively.
The capital and O&M costs with and without chemical oxidation are
$402,310, $432,908 and $91,905, $90,569 respectively. The total
present worth for this alternative with and without chemical
oxidation is $1,831,805 and $1,841,865 respectively.
F. Operable Unit 4 - Davy Creek and the Wetlands
F.I Alternative DW1
The objective of this alternative is to minimize potential risks
to public health and the environment associated with the
contaminated sediments by removing the contaminated sediments
from the wetlands area and portions of Davy Creek. This interim
action will be followed by a final action once the planned
sediment study is completed.
A berm would be constructed around the contaminated wetlands area
to prevent surface water infiltration. The area would then be
dewatered with pumps and the sediment (" 5,200 yd3) excavated to
a depth of 2 feet. Sediment from Davy Creek (750 yd3) would also
be excavated to a depth of 2 feet. See Figure 4-8. The length of
creek to be remediated extends from the OEC discharge point south
to slightly past the discharge point of the municipal water
treatment plant. The sediment would be dewatered in a
sedimentation basin/lagoon, loaded on to trucks and transported
to a RCRA subtitle C permitted treatment and disposal facility.
The treatment of these wastes would be in accordance with the
RCRA LDR requirements. Water decanted from the sedimentation
basin/lagoon would be filtered and discharged directly to Davy
Creek according to WPDES discharge standards. The filter
technology to be utilized will be determined during the remedial
design based on the discharge limits provided by the State. The
excavated area would not be backfilled in order to prevent the
potential for additional wetlands disturbance and/or destruction
-------
Si l.e I.iou ncl n ry
j.
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-
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ENVIRONMENTAL PROTECTION />GI:NCY
OCONOMOWOC ELECIROPLAIING COMPANY
FIGURE H-B
AREA OF PROPOSE
WETLAND EXCAVATION
EBASCO SERVICES iNCOHPORATtD
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28
or introducing nonnative vegetation. Once the sediments have been
excavated and disposed off-site the berm structure would be
removed. If the berm material is not contaminated it would be
used as fill material for the closure of the sedimentation basin.
Clean fill and top soil would also be used to fill the
sedimentation basin. After filling the basin it would be
revegetated. This interim action will remove most of the highly
contaminated sediments, but is not anticipated to be the final
action for this media.
With regard to location-specific ARARs, Federal and state
regulatory programs which are applicable to this remedial
alternative include those pertaining to the protection and
management of wetlands and floodplains. This interim action is in
compliance with these ARARS to the extent practicable.
Destruction or disturbance of portions of the wetlands is
unavoidable if the contaminated sediments are removed. WDNR and
the U.S Fish and Wildlife recognize that this destruction or
disturbance will occur. The action is necessary to remove the
significant contamination from the site. Remedial actions would
have to be continually monitored to minimize and assess damage to
the wetlands area.
Chemical-specific ARARs which are applicable to the site include
Wisconsin's ambient water quality criteria and effluent
limitations derived from NR 105 and NR 106 to protect the present
and prospective use classification of Davy Creek and the
wetlands. These water quality standards are legally applicable or
relevant and appropriate to the site. Any discharges or release
of contaminants to the wetlands area must meet the established
effluent limitations/water quality criteria to protect and
maintain the Full Fish and Aquatic Life classification of the
water body.
The present worth cost for this alternative is $4,995,422.
F.2 Alternative DW2
This alternative is identical to Alternative DW1 with the
exception that the sediments will be stabilized on-site. ARAR
compliance for this alternative is the same as the previous
alternative. See Figure 4r-8.
The present worth cost for this Alternative is 5,000,584.
VIII. Comparative Analysis of Alternatives
A detailed analysis was performed on all alternatives for the
four operable units using the nine evaluation criteria in order
to select a site remedy. The following is a summary of the
comparison of each alternative's strength and weakness with
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29
respect to the nine evaluation criteria. The nine criteria are:
1) overall protection of human health and the environment, 2)
compliance with applicable or relevant and appropriate
requirements, 3) long-term effectiveness and permanence, 4)
reduction of toxicity, mobility, and volume, 5)short-term
effectiveness, 6) implementability, 7) cost, 8) state
acceptance, and 9) community acceptance.
A. Overall Protection of Human Health and the Environment
All of the remedial alternatives considered for the OEC site are
protective of human health and the environment by eliminating,
reducing, or controlling risks at the OEC site with the exception
of the no action, and minimal action alternative. As the no
action and the minimal action alternatives do not provide
protection of human health and the environment, they are not
eligible for selection and shall not be discussed further in this
document.
The lagoon alternative (LI) and soil alternative (SI) will remove
all contaminated materials from the site. This will eliminate
any unacceptable risks associated with these areas.
Soil alternative S2 will keep contaminated materials beneath a
low permeability cap. This would remove risks posed by dermal
contact, ingestion, and inhalation associated with the
contaminated soil. Capping would also reduce infiltration
through the contaminated material and therefore reduce
contaminant leaching to groundwater.
Both groundwater alternatives GW1 and GW2 will gradually remove
contaminants thereby reducing the risks from ingestion and off-
site migration.
Both alternatives for Davy Creek and the wetlands will remove the
more highly contaminated sediment from the site which will result
in significant risk reduction quickly
B. ARARS Compliance
Each alternative is evaluated for compliance with ARARS,
including chemical specific, action specific, and location
specific ARARS. All of the alternatives for the first three
operable units meet their respective ARARS. The alternatives for
the interim action will comply with those standards that are
applicable within the limited scope of this action.
With regard to location-specific ARARs, Federal and state
regulatory programs which are applicable to this remedial
alternative include those pertaining to the protection and
management of wetlands and floodplains. This interim action is in
compliance with these ARARS to the extent practicable.
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30
Destruction or disturbance of portions of the wetlands is
unavoidable if the contaminated sediments are removed. WDNR and
the U.S Fish and Wildlife recognize that this destruction or
disturbance will occur. The action is necessary to remove the
significant contamination from the site. Remedial actions would
have to be continually monitored to minimize and assess damage to
the wetlands area.
The sediment of the wetlands area were contaminated as a result
of improper discharges of F006 wastes from the OEC facility.
Therefore, the contaminated sediments must be managed as a
hazardous waste if picked up, according to RCRA's "contained-in"
interpretation.
C. Long- Term Effectiveness and Permanence
This evaluation focuses on the results of a remedial action in
terms of the risks remaining at the site after response
objectives have been met. The following factors are addressed
for each alternative: magnitude of remaining risk, adequacy and
reliability of controls.
Alternatives LI and SI comply with this criteria by removal of
the contaminated material associated with the respective operable
units and would reduce the contaminants on-site permanently.
Treatment and Off-site disposal in a RCRA landfill would further
control the contaminated materials. All risks associated with
the lagoons and soil would be reduced to protective levels.
Alternative S2 would contain the contaminated soil, thus
preventing direct contact and ground water migration risks posed
by the contamination remaining on-site. Periodic maintenance of
the cap would be required to insure that it maintains its low
permeability. Groundwater monitoring would also be required to
determine whether contaminant leaching and migration is adversely
affecting groundwater quality.
Both groundwater alternatives would slowly remove the
contaminated groundwater onsite. Removing a bulk of the
contamination will prevent migration towards the residential
wells. It is projected that the ground-water extraction and
treatment systems (Alternatives GW1 and GW2) may attain the
Ground-Water Cleanup Standards within 30 years or less. However,
ground-water quality will be evaluated to determine if the
remedial action objectives have been met. If, after the ground-
water operable unit has been operating, it becomes apparent that
it is not technically or economically feasible to achieve a
preventive action limit (PAL), then an alternate concentration
limit (ACL) may be established, not to exceed the Enforcement
Standards (ES).
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31
If, during the implementation of the remedy, it becomes apparent
that it is technically impracticable to achieve federal and State
Ground-Water Cleanup Standards, including any NR 140 ACL
established as discussed above, then the U.S. EPA in consultation
with the WDNR, may then consider the use of alternative methods
of controlling the ground-water contaminant plume or source to
achieve the standards. If those alternate methods are found not
to attain Ground-Water Cleanup Standards (including any ACL
established), then a CERCLA waiver may be considered. Measures
will be taken to ensure that this exposure pathway remains
protective over a period of time.
Both alternatives for Davy Creek and the wetlands will remove the
most highly contaminated sediments from the site. Off-site
treatment and disposal in a RCRA permitted landfill will further
control the contaminated materials.
D. Reduction of Toxicity, Mobility, or Volume Through Treatment
This alternative addresses the statutory preference for selecting
remedial actions that employ treatment technologies which
permanently and significantly reduce toxicity, mobility, or
volume of the hazardous substances. This preference is satisfied
when treatment is used to reduce the principal threats at a site
through destruction of toxic contaminants, irreversible reduction
of contaminant mobility, or reduction of total volume of
contaminated media.
For alternatives LI, SI, Dl, and D2 removal and stabilization of
the contaminated material at the source area assures the
reduction of mobility of contaminants at the site through
treatment (stabilization is considered treatment for F006 waste).
For alternatives Dl and D2 some contamination will remain
although its mobility will be monitored. Alternatives GW1 and
GW2 by removing and treating the groundwater will reduce the
toxicity and the mobility of the groundwater plume as well as the
volume of the plume.
The toxicity and volume of the contaminated material will not be
reduced for these alternatives but is considered.
E. Short-Term Effectiveness
This evaluation focuses on the effects to human health and the
environment which may occur while the alternative is being
implemented and until the remedial objectives are met. The
following factors were used to evaluate the short term
effectiveness of each alternative: protection of the community
during remedial actions, protection of workers during remedial
actions, environmental impacts from implementation of
alternatives, and time until remedial objectives are met.
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32
With regard to the community and onsite workers, all alternatives
will pose potential risks from dust and air emissions generated
during excavation activities because all alternatives require
some excavation. Perimeter air monitoring would be needed during
remedial activities to determine if steps are needed to protect
the community from adverse air emissions. Workers will be
required to wear the proper protective health and safety
equipment to protect their safety.
With regard to the time until remedial objectives are met, all
alternatives with the exception of GWl and GW2 should take a few
weeks to a few months to implement. Alternatives GWl and GW2
could take up to 30 years to achieve the cleanup goals.
With regard to environmental impacts, alternatives GWl and GW2
may result in a change in groundwater flow and will have to be
monitored so that no adverse impacts result to the wetlands.
Alternatives DWl and DW2 will have environmental impacts to the
wetlands and Davy Creek and a plan to mitigate these impacts
(e.g. restricting vehicle traffic in the wetland) will be
developed.
None of these alternatives will result in unacceptable short-term
risks to worker, residents, or the environment.
F. Implementablity
This evaluation addresses the technical and administrative
feasibility of implementing the alternatives and the availability
of the various services and materials required during its
implementation.
The alternatives LI, SI, Dl and D2, include excavation,
stabilization and off-site disposal which are all demonstrated
and commercially available. Conditions external to the site, such
as equipment availability, materials and services present no
problem at this time. The contaminated solids would be treated
and disposed of in an off-site landfill. Stabilization has been
determined to be the Best Developed Available Technology (BOAT)
for wastes contaminated with F006 wastes. At this time, the
specific location and capacity of the off-site landfill have not
yet been determined but should not pose a problem. Alternative
S2, capping, is well demonstrated and commercially available.
Alternatives GWl and GW2 are proven technologies and commercially
available. A treatability study will be necessary to determine
if ion exchange or chemical oxidation will be more practical in
removing cyanide from the groundwater.
Administratively, none of the alternatives should have any
problem with regard to implementation, although coordination at
both the State and local level will be necessary for
implementation.
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33
G. Cost
This evaluation examines the estimated costs for implementing the
remedial alternatives. Capital and O&M cost are used to
calculate estimated present worth costs for each alternative.
For the lagoons only one alternative was considered.
Its capital cost is $485,601 with no O&M costs. Alternative SI
has a capital cost of $253,966 and no O&M costs. Alternative S2
has a capital cost of $887,035 and an O&M cost of $13,340. The
cost for S2 is higher than SI, and S2 allows for contamination to
remain onsite. Alternatives GW1 and GW2 (with ion exchange) are
very similar with regard to meeting the remedial objectives, GW2
has a less costly present worth cost of $1,831,805 while GW1 has
a present worth cost of $3,081,130. The capital and O&M costs
for GW1 were $1,048,220 and $131,158 respectively. The capital
and O&M costs for GW2 were $402,310 and $91,905 respectively.
Alternatives DW1 and DW2 are also very similar in meeting the
cleanup objectives with DW1 present worth cost at $4,995,422 and
DW2 present worth cost at $5,000,584. Neither alternative has
any O&M costs.
H. State Acceptance
The State of Wisconsin concurs with EPA's selection of
alternatives for the four operable units at the OEC site. The
State of Wisconsin predicates their concurrence on the interim
nature of the response action planned in this ROD for Davy Creek
and the wetlands areas. The State would not concur with this ROD
if this was the final action for the wetlands and Davy Creek
areas.
I. Community Acceptance
Community response to the alternatives is presented in the
responsiveness summary which address comments received during
the public comment period.
IX. The Selected Remedy
Based upon considerations of the requirements of CERCLA, the
detailed analysis of alternatives, and public comments both U.S.
EPA and WDNR have selected the following alternatives for the
four operable units at OEC:
A. OU1; Alternative LI, lagoon closure, pump an estimated
72,000 gallons to the groundwater treatment system onsite
and excavate an estimated 650 cubic yards of lagoon sludge
and surrounding soil to be stabilized and disposed of at a
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34
RCRA permitted landfill. Cleanup levels will be consistent
with clean closure levels, in accordance with 40 CFR 264 and
NR 181, WAC;
B. OU2; Alternative SI, onsite soil excavation of
approximately 700 cubic yards of soil as shown on Figure 4-1
and off-site treatment and disposal. Cleanup levels will be
risked-based pursuant to Wisconsin law and the EPA policy on
implementing hybrid closures. Cumulative carcinogenic risk
due to soil ingestion should not exceed 1 x 10~6 risk
level, and the cumulative Hazard Index should not exceed
1.0;
C. OU3; Alternative GW2, installation of groundwater
recovery wells, an onsite treatment system including ion
exchange, air stripping and carbon absorption. A chemical
oxidation system will be utilized for treatment of cyanide
if a treatability study determines that ion exchange is
ineffective in removing cyanide from the groundwater. The
resultant ion exchange resin from this treatment process
would be properly disposed off-site at a RCRA permitted
landfill because it will contain an F006 waste. It will be
determined whether or not the spent carbon requires disposal
in a RCRA permitted landfill.
D. OU4; Alternative DW1 excavation of contaminated sediment
in Davy Creek and the wetlands to a depth of two feet, and
off-site stabilization and disposal of the contaminated
sediment. Sediment to a depth of approximately two feet
will be removed from the wetland and Davy Creek in order to
remove the most contaminated sediments in these areas.
Additional bioassay and risk assessment work will be
performed to determine the final exposure levels.
X. Statutory Determinations
The selected remedy must satisfy the requirements of Section
121(a-e) of CERCLA to:
A. Protect human health and the environment;
B. Comply with ARARs;
C. Be cost-effective;
D. Utilize permanent solutions and alternate treatment
technologies to the maximum extent practicable; and,
E. Satisfy a preference for treatment as a principle element
of the remedy.
The implementation of Alternatives LI, SI, GW2, and DW1 at the
OEC site satisfies the requirements of CERCLA as detailed below:
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35
A. Protection of Human Health and the Environment
Implementation of the selected alternatives will reduce and
control potential risks to human health posed by exposure to
contaminated soil, sediment, and ground water. Lagoon cleanup
will be to RCRA clean closure 40 CFR Part 264 Subpart G levels,
or the appropriate State RCRA requirements. Extraction and
treatment of contaminated ground water will be conducted to meet
federal and state Ground-Water Cleanup Standards. Soil and
debris at the site (i.e., the non-RCRA lagoon soils) will be
excavated and backfilled so that the direct contact exposure risk
will be reduced to 10~6 and migration of contaminants to ground
water will be mitigated to standards, consistent with EPA's
guidelines on hybrid clean closure. Cleanup levels in the
wetlands and Davy Creek have not been established pending the
results of the bioassay work. The selected remedy also protects
the environment by reducing the potential risks posed by site
chemicals discharging to surface water (Davy Creek) and the
wetlands.
With regard to the community and onsite workers, all alternatives
will pose potential risks from dust and air emissions generated
during excavation activities. Perimeter air monitoring will be
needed during remedial activities to determine if steps are
needed to protect the community from adverse air emissions.
Workers will be required to wear the proper protective health and
safety equipment to protect their safety. None of these short-
term risks will result in unacceptable exposures to human health
or the environment.
B. Compliance With ARARS
The remedies selected for operable units I, 2, and 3, will comply
with the federal, and state standards where more stringent, of
applicable or relevant and appropriate requirements (ARARs). The
selected, interim remedy for Operable Unit 4 will comply with
those ARARs that are pertinent, given the limited scope of this
action. The ARARs for the four operable units are listed below.
B.I Chemical-specific ARARS
Chemical-specific ARARs regulate the release to the environment
of specific substances having certain chemical characteristics.
Chemical-specific ARARs typically determine the extent of cleanup
at a site.
B.I.a Soils
The soil clean-up standards for the DEC site will be based on the
State's clean closure requirements (for the lagoons) and on EPA's
hybrid closure guidelines for the contaminated soil and debris at
the site.
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36
B.l.b Sediments
The removal criteria for the sediments in the wetlands, and
potentially Davy Creek, will be based on existing sediment
studies, as well as any additional information collected during
remedial design and action.
B.l.c Ground Water
i. Federal ARARs
Maximum Contaminant Levels (MCLs), and the non-zero Maximum
Contaminant Level Goals (MCLGs), the Federal drinking water
standards promulgated under the Safe Drinking Water Act (SDWA),
are applicable to municipal water supplies servicing 25 or more
people. At the DEC site, MCLs and MCLGs are not applicable, but
are relevant and appropriate, since the sand and gravel aquifer
is a Class IIA source which could potentially be used for
drinking in the area of concern (the contaminant plume). MCLGs
are relevant and appropriate when the standard is set at a level
greater than zero (for non-carcinogens), otherwise, MCLs are
relevant and appropriate. The point of compliance for ground
water standards will be attained throughout the plume within a
reasonable period of time, once all sources on site have been
addressed.
ii. State ARARs
The State of Wisconsin is authorized to administer the
implementation of the Federal SDWA. The State has also
promulgated ground-water quality standards in Ch. NR 140, WAC.
Chapter 160, Wis. Stats., directs the WDNR to take action to
prevent the continuing release of contaminants at levels
exceeding standards at the point of standards application.
Ground-water quality standards established pursuant to Ch. NR
140, WAC, will be preventive action limits (PALs), where
economically and technically feasible, or alternative
concentration limits (ACLs) not to exceed the State's ES.
Preventive action limits (PALs) and enforcement standards (ESs)
contained in section NR 140.10, WAC, for the Chemicals of Concern
are listed in Table 2-13. PALs (and ESs) are generally more
stringent than corresponding Federal standards . The State's
ground water law and code is a ARAR for this site, since those
laws were created to address ground water quality in general.
k
The implementation of the selected remedy at the OEC site will be
in compliance with Ch. NR 140, WAC, in that preventive action
limits (PALs) will be the clean-up standard for ground water. The
effectiveness of the ground water system in achieving that goal
will be reviewed periodically to determine if achieving the PAL
is technically and economically feasible, based on site-specific
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TABLE 2-13
REMEDIATION GOALS FOR
CONTAMINANTS OF CONCERN IN GROUNDWATER
Contaminant(s)
of Concern
Arsensic
Cadmium
Chromium
Copper
Cyanide
1,1-Dichloroethane
1,2-Dichloroethane
1,1-Dichloroethene
1,2-Dichloroethene
Lead
Manganese
Mercury
Tetrachloroethene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethene
Vinyl Chloride
Zinc
Regulatory Standards
MCL
(PPb)
___
5
100
1300
200
5
5
2
5
2
— — —
Wisconsin
En fore.
STD PAL
(Ppb)
50
10
50
1000
200
850
0.5
0.24
100
50
50
2
1
200
0.6
1.8
0.015
5000
(Ppb)
5
1
5
500
40
85
0.05
0.024
10
5
25
0.2
0.1
40
0.06
0.18
0.0015
2500
MCL - Maximum Contaminant Level
SDWA - Safe Drinking Water Act
Enforc.Std - Enforcement Standard
PAL - Preventive Action Limit
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37
information collected during remedial action. The initial review
of the ground water system shall occur within the first five
years of implementing the ground water remediation system.
Alternative concentration limits (ACLS), pursuant to the criteria
in section NR 140.28, WAC, will be established if it is
determined that attaining the PALs is infeasible, at any point in
the remedial action process.
i. Federal ARARs
Surface water quality standards for human health and aquatic life
protection were developed under the Clean Water Act (CWA) Section
304. The Federal Ambient Water Quality Criteria (AWQC) are non-
enforceable guidelines that set pollutant concentration limits to
protect surface waters that are applicable to point source
discharges, such as from industrial or municipal wastewater
streams. At a Superfund site, the Federal AQWC would not be
applicable except for pretreatment requirements for discharge of
treated water to a Publicly Operated Treatment Works (POTW).
CERCLA (Section 121(d)(l)) requires the U.S. EPA to consider
whether AWQC would be relevant and appropriate under the
circumstances of a release or threatened release, depending on
the designated or potential use of ground water or surface water,
the environmental media affected by the releases or potential
releases, and upon the latest information available. Since the
aquifer is a current and potential source of drinking water, and
treated water will be discharged to Davy Creek, AWQC adopted for
drinking water and AWQC for protection of freshwater aquatic
organisms are relevant and appropriate to the point source
discharge of the treated water into Davy Creek.
ii. State ARARs
Section 303 of the CWA requires the State to promulgate state
water quality standards for surface water bodies, based on the
designated uses of the surface water bodies. CERCLA remedial
actions involving surface water bodies must ensure that
applicable or relevant and appropriate state water quality
standards are met. The standards established pursuant to NR 105
and 106, WAC, would be ARARs for this site.
In addition Ch. NR 102, WAC establishes an antidegradation policy
for all waters of the State and it establishes water quality
standards for use qualifications. Chapter NR 102, WAC would be
applicable to actions that involve discharges to Davy Creek in
that discharges must meet water quality standards, as set forth
in Section B.3.ii, below.
B.2 Location-specific ARARS
Location-specific ARARs are those requirements that relate to the
geographical position of a site. These include:
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i. Federal ARARs
Executive Order 11990 - Protection of Wetlands is an applicable
requirement to protect against the loss or degradation of
wetlands. As discussed above, Alternative GW2 should be designed
not to have an adverse effect on the Davy Creek wetlands.
ii. State ARARs
Section 29.415, Wisconsin Statutes, and Chapter NR 27, WAC, are
State Endangered and Threatened Species laws which prohibit the
"taking" or harming of endangered or threatened wildlife
resources in the area. Since it is possible that endangered
species inhabit the wetlands, these statutes would be ARARs for
the site in that the poisoning of endangered or threatened
species by site contaminants could be considered by the WDNR to
be a "taking."
B.3 Action-specific ARARs
Action-specific ARARs are requirements that define acceptable
treatment and disposal procedures for hazardous substances.
i. Federal and State RCRA ARARs
Since the OEC was and is still operating a RCRA hazardous waste
site, the State's RCRA Subtitle C requirements are applicable.
The State's NR 181 requirements for clean closure of surface
impoundments would be applicable to the OEC lagoons since these
are regulated units pursuant to RCRA. The RCRA Subtitle C
standards are not applicable to the site's contaminated soil and
debris. However, since it is soil and debris contaminated with
an FOO6 hazardous waste, the RCRA closure requirements would be
relevant and appropriate. As established in the NCP, the EPA
may utilize the EPA's hybrid closure guidelines for remediating
the contaminated soil and debris, where RCRA is determined to be
relevant and appropriate. The EPA and WDNR have agreed to use
the hybrid closure guidelines when remediating the soil and
debris at OEC.
The substantive requirements of RCRA waste generation and
temporary storage regulations under 40 CFR Part 262 will be
followed when managing the treatment residuals from the ground
water system (e.g., ion exchange resins). Additional Federal
action-specific ARARs are found in the FS.
ii. State ARARs
The State is authorized to implement the National Pollutant
Discharge Elimination System (NPDES) program. The
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substantive requirements of a Wisconsin Pollutant Discharge
Elimination System (WPDES) permit, under Ch. NR 220, WAC, would
be applied to the discharge of the treated water into Davy Creek.
A permit is not required since the discharge point is considered
to be on-site. Subject to the approval of the U.S. EPA, effluent
limits for surface water discharge will be established by the
WDNR. Ch. NR 220, WAC requires that the effluent limits be based
on the application of best available treatment technology (BAT)
prior to discharge.
Chapter 147, Wisconsin Statutes, is also applicable to treated
water to be discharged to Davy Creek. These regulations state
that no discharge shall contain quantities of listed pollutants
greater than that would remain after subjecting the water to best
available technology economically achievable (BATEA).
Chapter NR 445, WAC regulates air emissions from treatment
technologies and is applicable to point source emissions from
industrial facilities. Since air strippers may emit hazardous
substances in the form of VOCs, section NR 445.04, WAC is
relevant and appropriate for the remedy. The need for emission
control technology shall be evaluated based on requirements of
Ch. NR 445, WAC. If air stripper emissions are projected to
exceed standards at the OEC property boundary, the point of
compliance, then vapor control technology such as vapor phase
activated carbon will be included in the treatment system to
bring air emissions into compliance.
C. Cost-effectiveness
Cost-effectiveness compares the effectiveness of an alternative
in proportion to its cost of providing its environmental
benefits. Table ES-5 lists the costs associated with the
implementation of the remedies.
1. Operable Unit 1 - RCRA Subtitle C Lagoon Closure
Clean closure of the surface impoundments affords the highest
degree of effectiveness and reduction of MTV by removing
contaminants so that the soils are excavated to background levels
required by Wisconsin RCRA regulations. This alternative was
determined to be cost-effective in that the costs incurred were
reasonable in light of the long*-term results achieved.
2. Operable Unit 2 - Soil and Debris
Alternative SI was less costly than alternative S2, yet provides
more long-term effectiveness, and a greater reduction of
toxicity, and mobility of the contaminants.
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TABLE ES-5
COST ESTIMATE SUMMARY
Alternative
Capital
Cost($)
Annual
O&M Cost($)
5-Year
Review($)
Total
Present
Worth($)
Alternative L1:
Lagoon Closure
Alternative S1:
Excavation and Disposal
485,601
253,966
6,000
6,000
490,302
258,667
Alternative GW2:
Groundwater Pumping and
Treatment (Ion Exchange)
Alternative GW2:
Groundwater Pumping and
Treatment (Chemical Oxidation)
Alternative DW1:
Excavation and Removal
402,310
432,908
4,986,020
91,905
90.569
6,000
6,000
12,000
1,831,805
1,841,865
4,995,422
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3. Operable Unit 3 - Groundwater
The two options for remediating the ground water provided
comparable performances with respect to long-term effectiveness,
short-term effectiveness and reduction of TMV. The only
difference between the two remedies was that alternative GW2 was
less costly.
4. Operable Unit 4 - Davy Creek and the Wetlands
Alternative DW1 was slightly less costly than Alternative DW2.
The alternatives had comparable performance with respect to long-
term effectiveness, short-term effectiveness, and reduction of
TMV.
D. Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
U.S. EPA and the State of Wisconsin believe the selected remedies
for the OEC Site represent the maximum extent to which permanent
solutions and treatment technologies can be utilized in a cost-
effective manner for the three final operable units and one
interim action at the OEC site. The selected remedies utilize
permanent solutions and alternative treatment technologies to the
maximum extent practicable ("MEP"). This finding was made after
evaluation of the protective and ARAR-compliant alternatives for
the OEC site remedial actions and comparison of the "trade-offs"
(advantages vs. disadvantages) among the remedial alternatives
with respect to the five balancing criteria (see above).
Once the threshold criteria of protection of human health and the
environment and ARARs-compliance were satisfied, the key criteria
used in remedy selection for the OEC site were long-term
effectiveness; reduction of toxicity, mobility, and volume
("TMV") through treatment; short-term effectiveness; and cost).
The priority given to long-term effectiveness and to reduction of
TMV at the site is consistent with U.S. EPA policy established in
the NCP. This policy states that long-term effectiveness and
reduction of TMV through treatment are generally the key decision
factors to be considered at Superfund sites.
1. RCRA Lagoon Remedy
*
The selected remedy's long-term effectiveness and its ability to
reduce the TMV of hazardous substances was weighed against its
short-term effectiveness aspects in relation to the remaining
alternatives. In general, the selected remedy does involve a
small degree of risk to site workers and to the community in that
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there would be movement and treatment of hazardous substances
during implementation in order to minimize the long-term effects
those substances would have on human health and the environment.
With respect to VOC-emissions during treatment of the lagoon
water and ground water, and contaminated dust during excavation
of soil, sludge and sediments, effective air monitoring would
ensure that air standards established to protect human health and
the environment are met. Emission controls may be utilized, if
necessary, to meet those standards. Short-term risks due to the
discharge of treated ground water to Davy Creek would be
minimized by ensuring that the treated water meets discharge
criteria, which are established to protect human health and the
environment as well.
The lagoon alternative complies with State and Federal ARARS
which require cleanup to clean closure standards. This provides
maximum long-term effectiveness by removing the contaminated
sludge and soil, treating it in accordance with the land
disposal restrictions, and disposing of it in a RCRA Subtitle C
land disposal unit, in compliance with the Superfund off-site
policy. The major factor upon which this selection was based was
the alternatives long-term effectiveness and its reduction of
mobility, toxicity or volume.
2. Soil and Debris Remedy
Alternative SI (excavation, treatment and disposal) has greater
long-term effectiveness than alternative S2 (closure of waste in
place) because SI removes a continuing source of contamination
and exposure from the site. The treatment of the soil and
debris to the LDR requirements (BOAT) will reduce the mobility of
the contaminants.
3. Ground-water Alternatives
Both ground-water alternatives provide for long term
effectiveness. Ground-water extraction and treatment will
utilize treatment to permanently address the principal threats
posed by the ground-water contaminant plume.
4. Davy Creek and the Wetlands Alternatives
Both alternatives DW1 and DW2 are interim actions. Further
monitoring of the wetlands will be necessary to determine the
long term effectiveness of the selected remedy. Stabilization
of the sediments will meet the LDR treatment standards.
D.I Summary
The combination of treatment and engineering controls being
implemented will minimize and eliminate threats remaining to
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achieve protectiveness. Negative short-term impacts during
implementation of the remedy will be minimized by health and
safety measures. The State has concurred with the selected
remedies for operable units one, two, three and four. Community
acceptance is addressed in the responsiveness summary.
E. Preference for Treatment as a Principal Element
The principal threats at the OEC site are the ground-water
contaminant plume, due to the potential use of the contaminated
water as a drinking water source, and the contaminated soil,
sediment and sludge due to direct exposure. The remedies
selected in this ROD satisfy the statutory preference for
treatment as a principal element of the remedy by treating the
ground water and excavating and stabilizing the contaminated
soils, and a portion of the contaminated sediments at the OEC
site.
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APPENDIX
RESPONSIVENESS SUMMARY
OCONOMOWOC ELECTROPLATING COMPANY INC. SITE
ASHIPPUN, WISCONSIN
I. Responsiveness Summary Overview
In accordance with CERCLA 117, the U.S. Environmental Protection
Agency (U.S. EPA) held a public comment period from July 23, 1990
through August 22, 1990 for interested parties to comment on the
Proposed Plan (PP) for the interim remedial action at the
Oconomowoc Electroplating Company (OEC) Site in Ashippun,
Wisconsin.
The PP, provides a summary of the background information leading
up to the public comment period. Specifically, the PP includes
information pertaining to the history of the OEC Site, the scope
of the proposed cleanup action and its role in the overall Site
cleanup, the risks presented by the Site, the descriptions of the
remedial alternatives evaluated by EPA, the identification of
EPA's preferred alternative, the rationale for EPA's preferred
alternative, and the community's role in the remedy selection
process.
EPA held a public meeting at 7:00 p.m. on July 25, 1990 at the
Ashippun Town Headquarters in Ashippun, Wisconsin to outline the
remedial alternatives for the four operable units described in*>
the PP and to present EPA's proposed remedial alternative for
controlling contamination at the OEC Site.
The responsiveness summary, required by the Superfund Law,
provides a summary of citizens' comments and concerns identified
and received during the public comment period, and EPA's
responses to those comments and concerns. All comments received
by EPA during the public comment period will be considered in
EPA's final decision for selecting the remedial alternative for
addressing contaminated at the OEC Site.
This responsiveness summary is organized into sections and
appendices as described below:
I. RESPONSIVENESS SUMMARY OVERVIEW. This section outlines
the purposes of the Public Comment period and the
Responsiveness Summary. It also references the
appended background information leading up to the
Public Comment period.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS. This
section provides a brief history of community concerns
and interests regarding the OEC Site.
III. SUMMARY OF MAJOR QUESTIONS AND COMMENTS RECEIVED DURING
THE PUBLIC COMMENT PERIOD AND EPA RESPONSES TO THESE
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COMMENTS. This section summarizes the oral comments
received by U.S. EPA at the July 25, 1990 public
meeting, and provides U. S. EPA's responses to these
comments.
IV. WRITTEN COMMENTS RECEIVED DURING THE PUBLIC COMMENT
PERIOD AND EPA RESPONSES TO THESE COMMENTS. This
section contains the letter received by EPA containing
written comments, as well as EPA's written response to
that letter.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS
Local awareness of the OEC site is very high, because startup of
the Remedial Investigation (RI) was delayed in 1986 due to a lack
of funds which in turn delayed the submission of the Dodge County
Drainage Board's application to rechannel Davy Creek. This was
a result of the decision of the U.S Army Corps of Engineers (U.S
ACE) that the application to rechannel Davy Creek could not be
submitted until the final RI was complete and the extent of
contamination was known. Local residents have lost farmland to
wetlands over the past twenty years and want to reclaim them,
although the Department of Interior has taken the position that
the wetlands are protected and attempts to drain them will not be
allowed. The local residents are in the process of attempting to
rechannel Davy Creek to mitigate flooding and stop the loss of
existing farmland.
A local community group was formed called "People for the Cleanup
of the Davy Creek Toxins". This group has been very active in
generating community support for the quick remediation of the OEC
site.
A health issues workshop was held on July 5, 1988, to inform the
local residents of the potential risk associated with the site
and a public meeting was held immediately afterward to inform the
residents of the Super fund process and the work to be conducted
under the RI. Major issues raised during the July 5, 1988,
public meeting included the following:
Why the start of the RI had been delayed;
Why the wetlands could not be drained to return them to
farmland;
Why the government was allowing OECI to discharge after they
had caused the site contamination.
An attempt was made by the RPM to satisfactorily respond to the
issues, although as discussed above the issue of the wetlands has
come up on every subsequent public meeting and is still very much
an issue with the local residents.
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On March 28, 1990, a RI/FS update meeting was held to inform th'
local residents of the results of the RI and give a schedule for.
the FS, ROD, and remedial design and construction. The major
issue again concerned the wetlands and the rechannelization of
Davy Creek.
As part of EPA's responsibility and commitment to the Superfund
Program, the community has been kept informed of ongoing
activities conducted at the OEC site. U.S. EPA has established a
repository at the F&M Bank, in Ashippun, Wisconsin, where
relevant site documents may be viewed. Documents stored at the
repository include:
The final RI and Feasibility Study for the site;
The PP for the site;
Fact sheets, summarizing the technical studies conducted at
the site;
Public Meeting Transcript.
U.S. EPA's selection of a remedy to cleanup the contamination at
the OEC site will be presented in a document known as a Record of
Decision (ROD). The ROD and the documents containing information
that U.S. EPA used in making its decision (except for documents
that are published and generally available) will also be placed
in the information repository, as will this responsiveness
summary.
III. Summary of Major Questions and Comments Received During the
Public Comment Period and U.S. EPA Responses to These Comments
Oral comments raised during the public comment period for the OEC
Site interim remediation have been summarized below together with
U.S. EPA's response to these comments.
COMMENT: A resident inquired whether the 55 gallon drums left
from the remedial investigation could be removed from the site
within 30 days.
RESPONSE: The waste contained in the 55 gallon drums is
considered a Resource Conservation and Recovery Act (RCRA) F006
hazardous waste. The drums are secured in a locked chain link
fence and are scheduled for removal when the remedial action
begins in 1992.
COMMENT: A resident asked why the wetland and Davy Creek would
not be remediated to the same health based cleanup levels as the
site soils.
RESPONSE: Excavation to a depth of two feet in Davy Creek and the
wetlands is being done to remove the most significant
contamination in these areas as an interim action. Additional
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bioassay work is being performed to determine the level
protective of the environment. Based on a determination of the
level protective of the environment, it will be determined
whether any further response is necessary in Davy Creek.
COMMENT: One resident stated that the contamination at the OEC
Site was very serious and that she felt that U.S. EPA had come up
with the best solution for the problem and that she supported the
remedial alternatives.
RESPONSE: U.S. EPA acknowledges the comment.
COMMENT: Can another public meeting be held between all
responsible parties involved with the Davy Creek
rechannelization including U.S. ACE, Fish and Wildlife, Wisconsin
Department of Natural Resources, and U.S. EPA.
RESPONSE: An attempt will be made in the near future to have all
of the involved parties attend a public meeting as soon as they
have had a chance to review and take a position on the proposed
Davy Creek rechannelization.
IV. Written Comments Received During the Public Comment Period.
The written comments regarding the OEC site have been summarized
below, together with U.S. EPA's responses to these comments.
COMMENT: The wetlands study and contamination from the
manufacturing area should be more carefully studied before
remediation begins. Also, the Site continues to operate and will
the continued operation result in additional contamination after
the remediation is complete.
RESPONSE: The wetlands are in the process of being very carefully
studied to determine chronic toxicity levels. After the
remediation is complete, the wetlands monitoring will continue
to determine if the remedy is protective of human health and the
environment. With regard to the manufacturing area, the
remediation will be closely monitored so that contamination
during the remediation does not runoff to the wetlands.
Additional contamination from the OEC effluent is not anticipated
because U.S. EPA has filed a civil suit against OEC for effluent
violations, requiring that OEC comply with their NPDES permit.
COMMENT: I feel a need to protect the environment, although I do
not feel that my rights as a landowner should be compromised for
the sake of maintaining wetlands that developed after I bought my
property.
RESPONSE: Whether or not the wetlands remain is not directly
related to this remediation and will be addressed by the
appropriate agencies after the rechannelization of Davy Creek is
formerly submitted to the U.S. ACE.
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COMMENT: "PEOPLE FOR THE CLEANUP OF THE DAVY CREEK TOXINS" are in
favor of the PP to cleanup the OEC site so long as the
remediation in the wetland and Davy Creek will be protective of
human health and the environment.
RESPONSE: Excavation to a depth of two feet in Davy Creek and the
wetlands is being done to remove the most significant
contamination in these areas as an interim action. Additional
bioassay work is being performed to determine the level
protective of the environment. Based on a determination of the
level protective of the environment along with human health, it
will be determined whether any further response is necessary in
Davy Creek.
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State of Wisconsin \ DEPARTMENT OF NATURAL RESOURCES —
Ctrnll 0, Btitdny, Secretary
BOX 7927
Mtdrton, Wiconiln 53707
TELEFAX NO. «0«-2«7-3S79
TOO NO. 604-267-6897
SOUO WASTE TELEFAX NO. 60*267.2768
September 18, 1990 IN REPLY REFER TO: 4440
Mr. Valdas V. Adamkus, Regional Administrator
U.S. Environmental Protection Agency
230 South Dearborn Street
Chicago, IL 60604
SUBJECT: Selected Superfund Remedy
Oconomowoc Electroplating Company, Inc. Site
Town of Ashippun, Dodge County, WI
Dear Mr. Adamkus:
The Department 1s providing you with this letter to document our position on
the proposed remedy, which Includes 4 operable units, for the Oconomowoc
Electroplating Company, Inc. Site (OECI). The proposal, as Identified 1n the
draft Record of Decision, Includes the following:
Clean closure of the RCRA subtitle C sludge lagoons.
j ^
soils would be excavated, with off-site treatment and disposal at
a RCRA Subtitle C facility. Contaminated lagoon water would be
treated.
Alternate clean closure of contaminated soil areas.
Approximately 700 cubic yards of contaminated soil would be
excavated, with off-site treatment and disposal at a RCRA Subtitle
C disposal facility.
Extraction 'and treatment of contaminated grouhdwater.
Contaminated groundwater would be" extracted and treated with an
on-s1te treatment unit. The treated water would be discharged
Into Davy Creek 1n compliance with the substantive requirements of
the Wisconsin Pollutant Discharge Elimination System.
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Excavation of contaminated sediment from the Davy Creek wetlands.
Approximately 6000 cubic yards of contaminated sediment would be
excavated from the wetlands, with subsequent treatment and
disposal at an off-site RCRA Subtitle C disposal facility. This
operable unit would be an interim action. Further Investigation
of the problem would occur. Potentially, another remedy would be
necessary.
The total 30 year present net worth for the OECI Operable Units is estimated
to b<> approximately $6,200,000, of which $4,776,000 is estimated to be capital
cost and $92,000 per year Is estimated to be annual operation and maintenance
cost«. The Department concurs with the preferred remedy, as described above
and In the Record of Decision for these operable units.
We understand that 1f the potentially responsible parties (PRPs) dp not agree
to "fund the remedy,"'the"Statef'o'f Wisconsin will contribute 10 percent of the
remedial action costs associated with this remedy.
We also understand that our staff will continue to work in close consultation
with your staff during any remaining Investigative work associated with the
OECI site, as well as during the design and construction of the operable unit
remedies.
Thani< you. for your support and., cooperation in addressing this contamination
problem at the OECI site. If you have any questions regarding this matter,
please contact Mr. Paul Did'ier, Director of the Bureau of solid and Hazardous
Wast* Management, at (608) 266-1327.
Sincjrelv,
C. D.ijtes>dny
Secretary
CDB::v
cc: Lyman Wible • AD/5
Linda Meyer - LC/5
_Paul.D1d1er - SW/3
Joe Brusca/Mike Schmoller - SOD
Wendy Carney/Tom Williams - EPA Region V (5HS/11)
Mark G1esfeldt/Sue Bangert/Celia VanOerLoop - SW/3
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