Abstract |
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. 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), continued into the wetlands. 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 OEC 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). 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. |