The U.S. Environmental Protection Agency has proposed a new lead cleanup standard for residential soil and interior dust at the Butte Superfund site, setting the action level at 456 parts per million — a significant reduction from the current threshold but higher than a figure the agency had previously signaled.
The Proposal
Under the plan put forward by EPA Regional Administrator Cyrus Western, the cleanup action level for lead in Butte residential soil and indoor dust would fall from 1,200 parts per million to 456 parts per million. The agency had earlier indicated it was considering a standard of 175 parts per million, a figure that now appears to have been set aside.
The proposal also expands the cleanup area to cover an additional 7,100 homes and shortens the evaluation timeframe from 25 years to 15 years — changes local county officials described as a step forward, though not without lingering questions.
Local Reaction: Mixed, and Pointed
Butte-Silver Bow County’s Department of Reclamation and Environmental Services director, Eric Hassler, acknowledged progress while raising a pointed concern about the agency’s shifting numbers. “Butte-Silver Bow feels it’s a positive move in the right direction, but still has questions regarding why the proposal of 175 in 2024 versus the proposal of 456 in 2026,” Hassler said.
Environmental advocates were sharper in their criticism. Evan Barrett of Butte Watchdogs for Social and Environmental Justice said the agency had effectively moved the goalposts in the wrong direction. “They’re actually proposing raising the rates from what they told us before,” Barrett said. “That’s not acceptable, frankly.”
Critics also pointed to a geographic gap in the proposal: a portion of the community near Margaret Leary Elementary School was omitted from the expanded map of the Butte Priority Soils Operable Unit, raising concerns about which neighborhoods will ultimately qualify for cleanup action.
Background on the Superfund Site
Butte’s Superfund designation stems from more than a century of copper mining that left heavy metals, including lead, distributed across residential neighborhoods and yards throughout the city. Lead contamination poses particular risks to children, whose neurological development can be harmed at relatively low exposure levels.
The question of what cleanup threshold is sufficient has been a persistent source of tension between federal regulators, county government, and community groups. The EPA’s earlier indication of a 175 ppm standard had raised expectations among advocates, making the jump to 456 ppm in the current proposal a source of frustration.
A similar dynamic is playing out at other Montana environmental sites where federal regulatory decisions are drawing local scrutiny. A federal court challenge over an EPA wastewater permit for a Montana Renewables facility in Pondera County is pending, and a 30-day public comment period is open for a Stillwater Mine expansion review in the state’s south-central region.
Public Comment Opportunity
The EPA has scheduled a public comment session for Tuesday, June 17, from 5 to 7 p.m. at the Tech auditorium in Butte. Residents and stakeholders who cannot attend in person may submit written comments by email or mail, with a deadline of 11:59 p.m. on June 30, 2026; mailed comments must be postmarked by that date.
What Comes Next
The comment period gives Butte residents, county officials, and advocacy groups a formal window to push back on the proposed 456 ppm threshold or the omission of the Margaret Leary Elementary School area from the expanded cleanup map. Whether the EPA will adjust the final standard in response to public input remains to be seen.
For a community that has lived with Superfund designation for decades, the gap between the 175 ppm level previously floated and the 456 ppm now on the table is likely to define the public debate in the weeks ahead. County officials and local watchdog groups have made clear they intend to use the comment process to press the agency for answers.
