Unity Auto Mart

Overview

Unity Auto Mart sits in the Village of Unity, Wisconsin, and includes a former gas station, convenience store, and dry-cleaning operation. The dry cleaner ran from 1979 to 1984 and released tetrachloroethene (PCE) and related chemicals into the soil and groundwater. State officials first detected the contamination in 1999. By 2014, testing showed that multiple private drinking water wells in the village contained PCE above safe limits. The U.S. Environmental Protection Agency (EPA) added the site to the Superfund National Priorities List (NPL) in March 2022 because it poses significant risks to human health and the environment.

The contamination plume covers roughly 25 acres and has reached two aquifers. Most residents within a 4-mile radius rely on private groundwater wells for drinking water. Seventeen of those wells have been contaminated with PCE and its breakdown products, including trichloroethylene (TCE), cis- and trans-1,2-dichloroethylene (1,2-DCE), and vinyl chloride. Eight wells have contamination levels above the Safe Drinking Water Act's Maximum Contaminant Levels. The Wisconsin Department of Natural Resources provided carbon filters and alternate water supplies to affected households.

EPA conducted a removal action from November 2015 through October 2018 to address immediate risks. A remedial investigation began in April 2024 as part of a broader sitewide effort. EPA and its contractors plan to continue sampling private wells in 2026, install monitoring wells, and collect samples near the suspected contamination source. This work will help determine how far the contamination has spread and support development of a formal cleanup plan. A feasibility study is being conducted alongside the remedial investigation, but EPA has not yet selected a cleanup remedy or completed physical construction.

Current data are insufficient to determine whether human exposure is under control or whether groundwater migration has stabilized. The site is not yet ready for its anticipated use, and key milestones such as remedy selection, start of remedial action, and construction completion remain ahead.

Community members can stay involved by reviewing the community meeting presentation available on the Unity Auto Mart page of the EPA website. They can also contact EPA's Community Involvement Coordinator or Remedial Project Manager.