The Auto Ion Chemicals Inc. Superfund (Auto Ion) site is a 1.5-acre parcel of land located in Kalamazoo, Michigan. The site is in a light industrial area and is bordered by the Kalamazoo River along its southern edge. The property was originally used as an electrical generating station by the City of Kalamazoo from sometime during the 1940s until 1956. From 1964 to 1973, Auto Ion Chemicals operated a treatment facility for electroplating waste at the site. Wastewater was discharged to the sanitary sewer, and sludges were disposed of in an on-site lagoon. Poor storage and waste handling practices resulted in numerous spills onto surface soil and within the basement of the facility building, and several unpermitted discharges to the Kalamazoo River and city sewers were documented. In 1973, the Auto Ion facility ceased operations after its license to transport, store, and treat liquid industrial waste was not renewed by the State. Contaminants of concern at the site are heavy metals associated with electroplating waste, such as cadmium, chromium, nickel and zinc, and two volatile organic compounds.