PB98-963141
EPA 541-R98-153
March 1999
EPA Supei fund
Explanation of Significant Difference
for the Record of Decision:
Kohler Company Landfill
Kohler, WI
9/29/1998
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EXPLANATION OF SIGNIFICANT DIFFERENCES FOR
KOHLER COMPANY LANDFILL
KOHLER, WISCONSIN
1.0 Introduction
This Explanation of Significant Differences (ESD) is for the Kohler Company Landfill located
near the Village of Kohler, Wisconsin. This ESD is being issued, pursuant to Section l17(c) of
the Comprehensive Environmental Response, Compensation and Liability Act, and Section 40
CFR 300.435(c)(2)(i) of the National Contingency Plan, by the United States Environmental
Protection Agency (EP A) following consultation with the Wisconsin Department of Natural
Resources (WDNR). The ESD presents to the public an explanation of significant changes in the
requirements for capping the landfill. These are components of the remedial action approved for
the Kohler Company Landfill Site in the 1992 Record of Decision (ROD). However, a
fundamental change to the remedy, which would require a ROD Amendment, is not being
proposed.
The purpose of this ESD is to clarify the scope of the actions outlined in the 1992 ROD. The
1992 ROD required a multilayer cap to be constructed in phases over the hmdfill. The work
called for in the 1992 ROD has been completed over the lower half of the landfill, especially on
portions of the landfill that exhibited seepage and unstable slopes. The old hazardous waste
disposal areas within the waste mass that have not yet received final cover have been covered
with non-hazardous solid and/or interim cover. Consequently, there is no exposed hazardous
waste. The active portion of the landfill will remain open until the facility achieves its final
grade as specified in the approved State closure plan and will then be closed subject to State
closure rules under chapters NR 500-520, Wisconsin Administrative Code.
This ESD and its supporting documentation will become part of the Administrative Record for
the Kohler Compa"ny Landfill. This Administrative Record, supplemented by the supporting
documents for this ESD, are available for review at either location:
Meade Public Library
710 N. 8th Street
Sheboygan, Wisconsin 53081
Kohler Public Library
230 School Street
Kohler, Wisconsin 53044
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2. Site History and Information on Selected Remedies
The Kohler Company Landfill site is located in the NE 1/4 of the SE 1/4 of Section 29, T l5N,
R23E, within the corporate limits of the Village of Kohler, Sheboygan County, Wisconsin. The
landfill is situated on an 82-acre parcel of land which is bounded on the south, east and far west
by the Sheboygan River, to the west and south by County Trunk Highway "A" and to the north by
Highway "PP". Approximately one-half of the permitted 82-acre parcel has been used for waste
disposal.
Surrounding land uses include industrial (the Kohler Company plant), residential and
conservancy along the banks of the Sheboygan River. Residences in the vicinity of the landfill
rely on public drinking water derived from Lake Michigan. The only deep water supply wells in
the area provide production water for the Kohler manufacturing plant and irrigation water for the
nearby Blackwolf Run Golf Course.
The landfill, which is still open and licensed by the WDNR, has been in operation since the
19505, mostly for the disposal of foundry and other manufacturing wastes (foundry sand, pottery
cull, cores, and clay waste) produced by the nearby Kohler Company manufacturing plant. These
waste streams are considered non-hazardous under RCRA. However, during the 1950s, 60s and
eariy 1 970s, waste disposal pits were constructed within the landfill for the disposal of hydraulic
oils. solvents, paint wastes, enamel.powder (containing lead and c~dmium), brass lint, and
chrome plating sludges. Landfilling of all solid and liquid hazardous wastes ceased prior to
1980.
. At the recommendation of the WDNR, the U.S. EPA listed the Kohler Landfill site on the
National Priorities List (NPL) in 1983. In 1985, the Kohler Company entered into an
Administrative Order by Consent to perform a remedial investigation and feasibility study
(RI/FS). Subsequent to the Order, the site was split into two units, a Source Control Operable
. Unit (SCOU) and a Ground Water Operable Unit (GWOU).
The RI/FS for the SCOU was completed in 1991. The results of the investigation indicated that
there were contaminants present in the landfill soils, both shallow and deep ground water, and in
leachate seeps found along the eastern slope of the landfill. The contaminants of concern
(COCs) included a large list of volatile organic compounds (VOCs), metals, semi-volatiles and
inorganic compounds. Contaminants detected included trichloroethene, vinyl chloride,
1 ,2-dichloroethene, toluene. lead, cadmium, nitrates and sulfate.
After reviewing the results of the RIfFS, the U.S. EPA issued a proposed plan for the SCOU in
October, 1991 selecting capping with a shallow toe drain along the eastern slope as the source
control remedy. The SCOU Record of Decision (ROD) was finalized in 1992. The lead for the
site was then passed from the U.S. EPA to the State of Wisconsin for oversight of the SCOU
design and implementation, and for completion of the GWOU action. The U.S. EPA and the
State of Wisconsin issued a ROD for the GWOU in June of 1996.
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The selected remedy for both operable units included the following:
Removing existing cover material and vegetation from previously closed areas of the
landfill.
Installing a multi-layered clay capping system over the waste fill area.
Constructing surface water control features.
Installing a ground water interceptor drain system along the eastern and southern
perimeter of the landfill to an approximate depth of 10 feet and length of 2500 feet.
Discharging the water captured by the perimeter drain system into a force main that
connects to the City of Sheboygan's Publicly Owned Treatment Works (POTW).
Natural attenuation of the contaminated ground water that has already migrated beyond
the waste mass.
Long-term monitoring of ground water and effluent to measure the effectiveness of the
remedy.
3.0
DESCRIPTIONS OF SIGNIFICANT DIFFERENCES AND THE BASIS FOR
THOSE DIFFERENCES
This ESD makes the following revisions to the Kohler Company Landfill 1992 ROD:
As part of the remedial action, a portion of the waste fill area within the landfill was left
uncapped to accommodate future waste filling activities by the Kohler Company. This area is
currently operating under a license from the WDNR. Consistent with the existing license
requirements, the remaining landfill area will be capped with a low-permeability clay cover
system subject to State closure rules under chapters NR 500-520, Wisconsin Administrative
Code once waste filling has reached final grade as determined by the WDNR. The State of
Wisconsin, Bureau of Waste Management, has the regulatory authority for ensuring the adequacy
of the landfill's final closure consistent with existing license requirements. As such, no further
Federal response is needed at the Site.
4.0
SUPPORT AGENCY COMMENTS
WDNR is in agreement with the modifications made by the EPA to the March 1992 ROD, as
expressed in this ESD.
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5.0
AFFIRMATION OF THE STATUTORY DETERMINATION
Considering the new information that has been developed and the changes that have been made
to the selected remedy, EPA and WDNR believe that the remedy remains protective of human
health and the environment. The remedy complies with the Federal and State requirements that
are identified in this ESD and the ROD, which are applicable or relevant and appropriate to these
remedial actions. In addition, the revised remedy utilizes permanent solution and alternative
treatment to the maximum extent practicable for this Site.
6.0
PUBLIC PARTICIPATION ACTIVITIES
The Administrative Record, including this ESD, is available for public review at the repository
listed in Section 1.0.
The index for the Administrative Record supporting this ESD is attached.
~ r!7IJ -C
1-21-"
Date
William E. Muno, Director
Superfund Division
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