Wheeler Pit is a 3.8-acre former disposal area in La Prairie Township, Rock County, Wisconsin. General Motors dumped paint, wastewater sludge, and coal ash there from 1960 to 1974. Those operations left soil and groundwater contaminated with hazardous chemicals. EPA placed the site on the National Priorities List in September 1984 following an initial assessment in 1983.
EPA identified 17 contaminants of concern across groundwater, soil, and solid waste at the site. These include metals such as arsenic, cadmium, chromium, lead, and manganese. Organic chemicals found at the site include 1,4-dichlorobenzene, bis(2-ethylhexyl)phthalate, butyl benzyl phthalate, ethylbenzene, naphthalene, and xylene mixed isomers. Iron and manganese were also detected in groundwater.
The cleanup remedy for the landfill area included installing a multilayer cap, fencing the site, consolidating waste onsite, and setting up long-term groundwater monitoring. Institutional controls, including deed restrictions recorded in 2014 and a restrictive covenant on a neighboring property dating to 1995, limit land and groundwater use to prevent exposure to remaining contamination. Construction of the remedy finished in December 1992. Groundwater cleanup goals have been achieved, and contaminated groundwater has stabilized within the original contamination area. EPA deleted Wheeler Pit from the Superfund list in April 2004. The site reached sitewide ready for anticipated reuse status in September 2016.
Human exposure is currently under control across the entire site, with no unacceptable exposure pathways identified. Groundwater migration is also under control. EPA continues monitoring to confirm contamination remains in place. The most recent five-year review was completed in September 2022. The next five-year review is estimated to occur between September and November 2027. EPA is working with property owners and the Wisconsin Department of Natural Resources to update institutional controls.
Community members who have questions or want to share information about site conditions can contact EPA's Community Involvement Coordinator or Remedial Project Manager directly.
