Gelman Sciences Inc. sits near Ann Arbor, Michigan, and operated as a medical filter manufacturer from 1966 until 1986. Decades of waste handling at the facility released 1,4-dioxane, an industrial solvent, into the ground. The contamination spread into a plume that now affects groundwater across Ann Arbor and Scio Townships, including parts of Ann Arbor city itself. EPA added the site to the Superfund National Priorities List in March 2026, a step that gives the agency authority to act on the plume's eastern spread and protect the Ann Arbor aquifer for future use.
The site was first assessed in December 1985. EPA began evaluating it for National Priorities List eligibility in 2022 after a site inspection found 1,4-dioxane concentrations above three times background levels. EPA proposed the listing in March 2024 and received more than 150 public comments during a 60-day comment period. The agency coordinated with the Michigan Department of Environment, Great Lakes, and Energy throughout and secured the state's concurrence before moving forward. Michigan Environment, Great Lakes and Energy serves as the enforcement lead for the site's cleanup obligations.
A county circuit court ordered Gelman Sciences to act on the plume back in 1992. That order required the company to contain the plume, prevent groundwater use in contaminated areas, stop well use within or near the plume, and connect affected properties to municipal water. Cleanup work is organized into operable units, with one unit focused on groundwater. A combined remedial investigation and feasibility study for that groundwater unit is estimated to start between June and August 2027. No remedy has been selected yet, and construction has not begun.
Because physical cleanup work has not started, human exposure control and groundwater migration control cannot be determined at this time. The site has not been deleted from the National Priorities List, and key milestones such as remedy selection, remedial action, and construction completion remain ahead.
Community members who want to stay involved can review frequently asked questions about the site, learn about EPA's National Priorities List process, and consult resources from the state agency managing the plume. For direct questions, community members can contact the EPA's Community Involvement Coordinator or Remedial Project Manager.
