EPA Adds Gelman Sciences Inc. in Ann Arbor, Michigan, to the Superfund National Priorities List
CHICAGO (March 12, 2026) – Today, U.S. Environmental Protection Agency (EPA) added the Gelman Sciences Inc. site in Ann Arbor, Michigan, to the Superfund National Priorities List, a list of the nation's most contaminated sites.
“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.”
From 1963-1986, Gelman Sciences Inc. manufactured medical filters, a process that discharged wastewater containing 1,4-dioxane into surrounding ponds creating a contaminated groundwater plume. Health risks of 1,4-dioxane include liver and kidney damage and cancer. The 1,4-dioxane groundwater plume is approximately 3 miles long and 1 mile wide and has migrated into aquifers that supply drinking water. Currently, the company has an agreement with the state requiring them to pump and treat contaminated groundwater to lower the concentration of 1,4-dioxane within the plume, prevent groundwater use in contaminated areas, prevent well use within the plume, and connect affected properties to municipal water. This agreement does not require Gelman to restore the groundwater to beneficial use and allows the plume to migrate toward, and discharge to, the Huron River in compliance with the state’s groundwater to surface water interface criterion. With this NPL listing, EPA can take action to more effectively control the plume to reduce eastern migration and further degradation of the Ann Arbor aquifer and ensure uncontaminated portions of the aquifer can be used for future commercial and/or residential use.
Although there is currently no known human exposure, conditions at the site present a threat because of the potential for the plume to migrate and contaminate the Huron River and drinking water wells. 1,4-dioxane exceedances in private wells have already resulted in residential drinking water wells to be abandoned and residents to tie into municipal supplied water lines. In 2001, the city closed their municipal drinking water well, known as the Montgomery Wellfield, due to the presence of 1,4-dioxane.
The state asked EPA to list the site to the NPL in 2021. Following years of site assessments, EPA proposed to add site to the NPL in March 2024. EPA held a 60-day public comment period that garnered 151 public comments. Responses to the comments, which were primarily in support of the listing, are included in the final rule which is published on EPA’s website.
Background:
EPA adds sites to the Superfund NPL when releases of contamination pose risks to human health and the environment. This list serves as the basis for prioritizing EPA Superfund cleanup funding and enforcement actions. Only sites included on the NPL are eligible to receive federal funding for long-term, permanent cleanup.
Cleaning up Superfund sites provides tangible health and economic benefits to American communities. By adding the Gelman Sciences site to the NPL, EPA is advancing Administrator Zeldin’s Powering the Great American Comeback initiative by working to provide clean air, land, and water for all Americans. EPA uses all available tools to ensure protection of human health and the environment in partnership
with States and impacted communities. EPA only places sites on the NPL after confirming a threat to human health and the environment, evaluating various avenues for site cleanup, and determining that NPL is the most appropriate and effective option to achieve a protective cleanup.
Before EPA can add a site to the NPL, the site must meet listing requirements under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and be proposed for addition to the list through a rulemaking in the Federal Register, prompting a 60-day public comment period. EPA may officially add the site to the NPL if the site continues to meet the listing requirements after the public comment period closes and the agency has addressed all comments received during the comment period.
Learn more about Superfund and the National Priorities List.
For more information about the Gelman Sciences site, please visit our website.