Region 5 Superfund (SF)

U.S. EPA REGION 5
DODGE COUNTY
ASHIPPIN

Congressional District # 06

OCONOMOWOC ELECTROPLATING CO., INC.

EPA ID# WID006100275
Last Updated: October, 2006

Site Description

The Oconomowoc Electroplating Company Inc. (OEC) site was once an electroplating facility, located in Ashippun, Wisconsin. The cities of Oconomowoc and Watertown are approximately eight miles south and 10 miles west of the site, respectively. The OEC site occupies approximately 10.5 acres, which includes adjacent wetlands to the southwest . A small creek, Davy Creek, is located approximately 500 feet south of the site. Davy Creek flows through the wetlands, and is a tributary to the Rock River. The site is in a rural area, and the local population is less than 100 people. The site is complex, and has been divided into five discrete remedial actions:

Action 1 includes the surface water, metal hydroxide sludge, and contaminated soils that are associated with the two Resource Conservation and Recovery Act (RCRA) Subtitle C lagoons, located behind the OEC facility.

Action 2 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. Soil, contaminated with arsenic, cadmium, chromium, copper, lead, nickel, zinc, and cyanide, was found over the entire site area. Concentrations ranged from about 100 mg/kg to several thousand mg/kg in the creek and wetlands. 

Action 3 includes the contaminated groundwater that is associated with the site. Contaminants in the groundwater include trichloroethane (TCA) from the electroplating degreasing operations, cyanide, and the above metals from plating operations.

Action 4 addresses the most highly contaminated sediments in the Davy Creek/Wetlands area.

Action 5 includes the building foundation and underlying soils along with the chemicals and required removal. 

Site Responsibility

This site is being addressed through federal actions. 

Threats and Contaminants

The groundwater, wetland and creek sediments, and subsurface soils are contaminated with heavy metals, cyanide, and volatile organic compounds (VOCs) from electroplating activities. The heavy metals include chromium, cadmium, copper, nickel, and zinc. Ingesting, inhaling, or coming into direct contact with the contaminated soil, groundwater, or creek sediments may cause a potential health threat. The contaminants that threaten the aquatic organisms in the wetlands and creek sediments could bioaccumulate contaminants in their tissues and possibly pose a threat to anyone consuming those organisms. 

Cleanup Progress

A letter was sent to the chairman of OEC on July 30, 1990, pursuant to Section 122(a) of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), informing OEC that work would be undertaken by the United States Environmental Protection Agency (U.S. EPA), pursuant to Section 104(a) of CERCLA, because OEC appeared to lack the resources to conduct the remedial design (RD) and implement the remedial action. No negotiations were conducted, although a consent decree (CD) was signed, granting access to the land. U.S. EPA began the cleanup of the five OUs in May 1992 and completed it in September 1996. 

For Action 1, approximately 600 cubic yards of metal hydroxide sludge were removed from the sludge lagoons along with 72,000 gallons of lagoon water, contaminated with methylene chloride and acetone, and was disposed of offsite.

For Action 2, approximately 300 cubic yards of soil contaminated with heavy metals was removed from the site and taken to a hazardous waste disposal facility.

For Action 3, a groundwater treatment plant was built to treat approximately 21 million gallons of groundwater per year for TCA, cyanide, and metals.

For Action 4, 16,000 cubic yards of contaminated sediment were removed from Davy Creek and the wetlands and were disposed of at a hazardous waste disposal facility. Several thousand cubic yards of clean wetland-type soil were placed in the wetland to restore it.

For Action 5, the building and foundation were dismantled and removed from the site. The 56,917 gallons of cyanide, chrome and acid/alkaline solution were removed and taken to a hazardous waste disposal facility. 

A five-year review was signed on September 29, 1997. A second five-year review was signed on July 12, 2002. In general the reports have concluded that the remedy is protective of human health and the environment in the short-term. There are no current exposure pathways, and the remedy appears to be functioning as designed. The removal of lagoon sludge, soils, debris, and sediment to eliminate the source of contamination has achieved the remedial objectives to minimize the migration of contaminants to groundwater and surface water and prevent direct contact with, or ingestion of, contaminants in soils and sediments.

In 2004, the groundwater pump and treat system was evaluated for optimization. The results of the study demonstrated that the treatment system had removed a significant amount of contamination at the site, but was no longer effective in lowering contaminant levels, and that natural attenuation would cleanup the site faster than pumping and treatment. The system has been turned off while natural attenuation is evaluated.

The injection of substrate to enhance the cleanup was evaluated but found to be unnecessary since an adjacent wetland was serving this function. The site monitoring wells and adjacent residential wells are being sampled quarterly. Natural attenuation parameters are being evaluated, and a Record of Decision Ammendment is anticipated.

Contacts

Remedial Project Manager, U.S. EPA
william ryan (ryan.williamj@epa.gov)
(312) 353-4374

Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325

Aliases

OCONOMOWOC ELECTROPLATING CO. INC
OCONOMOWOC ELECTROPLATING CO INC

 

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