The U.S. Environmental Protection Agency (EPA) has added the former Gelman Sciences Inc. site in Ann Arbor to the federal Superfund National Priorities List, marking a significant step toward addressing a decades-old groundwater contamination problem.
This placement identifies the location as one of the nation’s most contaminated sites and allows the EPA to use additional legal authority and federal resources to accelerate cleanup efforts.
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“With this Superfund designation, EPA will use its statutory authorities to hold the company responsible for near- and long-term actions to more expeditiously address possible risks to human health and the environment,” said EPA Regional Administrator Anne Vogel. “Thanks to Administrator Lee Zeldin’s leadership, EPA is making good on its promise to the community to protect drinking water sources and ensure clean drinking water to families living in and near the community.”
Gelman Sciences Inc. is a former medical filter manufacturer, and the facility is located near Wagner Road. Manufacturing activities at the site between 1963 and 1986 released wastewater containing the industrial solvent 1,4-dioxane into nearby ponds, forming a large contaminated groundwater plume, according to a release from the EPA.
The plume is estimated to stretch roughly three miles long and one mile wide, and has migrated into aquifers that supply drinking water in the region. The groundwater contamination is in the western part of Ann Arbor and Scio Township.
--> The Michigan Department of Environment and Great Lakes (EGLE) created an interactive map of the Gelman site contamination. Click here to see the map.
Exposure to 1,4-dioxane has been linked to serious health concerns, including potential liver and kidney damage and an increased cancer risk, according to the release.
State regulators and the company currently have an agreement that requires the company to pump and treat contaminated groundwater, which is an effort to reduce concentrations of the chemical and limit its spread. The agreement also restricts groundwater use in affected areas, prevents well use within the plume, and requires certain homes to connect to municipal water supplies.
However, the EPA said the state agreement does not require full restoration of the aquifer and still allows the contaminated plume to move toward the nearby Huron River.
By placing the site on the Superfund National Priorities List, the EPA said it can take stronger action to control the plume’s movement, prevent further contamination of the aquifer serving the Ann Arbor area, and preserve uncontaminated sections of the groundwater system for future residential and commercial use.
Officials said there is currently no known human exposure, but the plume remains a concern due to the potential to migrate and contaminate the Huron River and drinking water wells.
Some private wells have already detected elevated levels of 1,4-dioxane, forcing homeowners to abandon those wells and connect to city water lines.
Contamination concerns have also affected municipal water supplies in the past.
In 2001, the City of Ann Arbor shut down the Montgomery Wellfield, their municipal drinking water well, after 1,4-dioxane was detected in the water source.
The state first asked the EPA to place the site on the Superfund list in 2021. After conducting evaluations for years, the EPA proposed the listing in March 2024 and opened a 60-day public comment period.
The EPA received 151 comments, the majority supporting the designation.
Sites that are added to the Superfund National Priorities List become eligible for federal funding and enforcement actions aimed at long-term environmental remediation.
The list helps the EPA prioritize cleanup of locations where contamination poses significant threats to public health or the environment.
The listing is intended to ensure stronger oversight of the cleanup process while protecting drinking water resources for communities in and around Ann Arbor, according to the release.