Overview:

  • The EPA adds the Gelman Sciences site to the Superfund National Priorities List after decades of groundwater contamination from industrial solvent dioxane.
  • The contamination plume spans 3 miles long and 1 mile wide, threatens drinking water aquifers, and discharges into the Huron River.
  • Superfund designation enables federal funding and stronger EPA oversight to control plume migration and restore groundwater for future use.

by Kyle Davidson, Michigan Advance
March 12, 2026

The U.S. Environmental Protection Agency on Thursday announced the Gelman Sciences Inc. site in Ann Arbor would be added to the Superfund National Priorities List. 

Between 1963 and 1986 Gelman Sciences manufactured medical filters, discharging wastewater containing 1,4 dioxane, an industrial solvent, into surrounding ponds, creating a groundwater plume. The plume is approximately 3 miles long and 1 mile wide, and has migrated into aquifers that supply drinking water. 

“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,” EPA Regional Administrator Anne Vogel said in a statement.

Dioxane carries several health risks including liver and kidney damage and cancer. According to the EPA, Gelman has an agreement with the state requiring it to pump and treat contaminated groundwater to lower the concentration of dioxane within the plume, prevent groundwater use in the contaminated area and well use within the plume and to connect properties affected to the municipal water system.

However, Gelman’s agreement does not require it to restore the groundwater, allowing the plume to migrate and discharge into the Huron River.

By adding the site to the Superfund National Priorities List, the EPA says it can more effectively control the plume, reducing its migration to the east, preventing further degradation of the Ann Arbor aquifer and ensuring uncontaminated portions of the aquifer can be used for future commercial or residential use.

U.S. Rep. Debbie Dingell (D-Ann Arbor) told Michigan Advance the Gelman plume’s inclusion as a Superfund site is a big deal. 

U.S. Rep. Debbie Dingell (D-Ann Arbor) reflects on her late husband, former U.S. Rep. John Dingell’s efforts to pass the Clean Water Act. | Kyle Davidson

“They delisted other sites, and everybody told us this could never happen,” Dingell said, with Republican President Donald Trump’s administration in control of the EPA.

However, this designation wouldn’t have been possible without EPA Administrator Lee Zeldin – a former Republican member of the U.S. House – and Regional Administrator Vogel, Dingell said.

“I called him. He paid attention, he saw the urgency,” Dingell said, emphasizing that when people get together from across the aisle to study the facts, they can get something done.

The state asked the EPA to include the Gelman site on the National Priorities List in 2021, with the EPA issuing a proposal to add it to the list in March 2024.

The Superfund site list collects the nation’s most contaminated sites. The sites included are eligible for federal funding for long-term, permanent cleanup.

Michigan Gov. Gretchen Whitmer also cheered the decision in a statement Thursday morning.

“Adding the Gelman plume to the National Priorities List is a meaningful step forward that strengthens the tools available to address contamination,” Whitmer said.

“It builds on the work we’ve done across Michigan to clean up damage caused by decades of disinvestment and strengthen clean water and environmental standards so every Michigander can have peace of mind knowing their community is safe.”

According to the Michigan Department of Environment, Great Lakes and Energy, the site’s listing marks the start of a coordinated federal-state cleanup process. The EPA will lead an assessment of the contaminated area, develop long-term remediation plans, and determine appropriate enforcement actions to address the source of contamination and protect groundwater.

Michigan Advance is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) public charity. Michigan Advance maintains editorial independence. Contact Editor Jon King for questions: info@michiganadvance.com.

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