The U.S. Environmental Protection Agency says a change in how it investigates leaking underground storage tanks is helping move contaminated sites toward closure faster, including several in Michigan.

EPA announced Sept. 24th that it addressed 10 leaking underground storage tank releases on Tribal lands in Michigan and Minnesota in 2026. It also removed a leaking tank in Wisconsin and says the work “saved taxpayers more than $550,000."

Nine of the closed releases were at four locations on Saginaw Chippewa territory near Mount Pleasant, Michigan. Another was at a gas station on Shakopee Mdewakanton Sioux territory near Prior Lake, Minnesota.

Underground storage tanks (USTs) are common at gas stations and other facilities that store gasoline, diesel and other regulated products below ground. EPA estimates there are about 542,000 nationwide. When a tank or its piping leaks, petroleum can contaminate surrounding soil and groundwater, potentially threatening nearby drinking water wells or creating vapor problems in buildings.

This change is how EPA is evaluating some of those sites.

What's the EPA's plan of attack?

In September 2025, the agency issued guidance aimed at streamlining investigations of petroleum UST releases. Instead of relying on a full site assessment in every case, the approach focuses testing on potential exposure pathways, including private drinking water wells and other places where people could come into contact with contamination.

EPA says the change can eliminate unnecessary testing while still determining whether contamination has moved offsite.

“EPA’s permitting reforms are cutting unnecessary testing, saving time and taxpayer dollars, and putting those resources back to work where they matter most,” EPA Regional Administrator Anne Vogel said. “That means faster site investigations, quicker tank removals when needed, and stronger protection for nearby properties through close coordination with Tribes.”

One Michigan project shows how that works in practice. In L’Anse, EPA worked with the Keweenaw Bay Indian Community to determine whether contamination from a former gas station had migrated toward Keweenaw Bay Ojibwa Community College across the street. EPA says testing determined the college was free from contamination, clearing the way for the Tribe to put the property into protected trust.

EPA is responsible for overseeing UST cleanup on Tribal lands and says it has identified more than 60 potentially leaking tanks across its Great Lakes region. Recently, crews discovered a nearly 100-year old gasoline tank in Harrison Township, Michigan. 

For groundwater and environmental contractors, the underlying job hasn't changed much: determine where a release went and whether it threatens people or water supplies.

EPA's newer approach puts more emphasis on answering those specific questions, particularly whether contamination has a pathway to drinking water wells or nearby properties, rather than automatically expanding the investigation across an entire site.

Will this approach work? 

It’s hard to say. The EPA juggles a variety of issues and many are afraid that this one will be swept under the rug after the smoke clears.