EPA proposes lower lead threshold, soil cleanup expansion in Butte

BUTTE, Mont. -- The Environmental Protection Agency (EPA) has officially proposed a new threshold for lead contamination in soil and attic dust to trigger remediation efforts, making much more of Butte eligible for that cleanup in the process.

The newly proposed lead action level, for which the EPA had set a deadline of June 1 to determine, lands at 456 parts per million, nearly three times lower than the previous standard of 1,200 ppm.

With this looser threshold, an additional 3,600 acres and 7,000 homes are set to become eligible for testing and/or cleanup within Butte's Superfund site boundaries.

EPA Region 8 administrator Cyrus Western says that the new number reflects the agency's goals of both protecting human health and allowing cleanup to move swiftly.

"What ultimately came out was the 2025 lead directive that I think brought a more holistic approach that protects human health--that is always number one, no matter what," Western said. "But it was also able to help the Superfund sites, including Butte, that were specifically dealing with lead on a navigable path forward that ensured protectiveness but also allowed these communities to progress and help us solve the problem, so that they're not just stuck spinning their wheels."

In 2026, the EPA hopes to sample 1,000 residences and remediate 100 yards in Butte. That work is set to pick up soon with summer on the horizon.

Western feels confident that they can surpass those numbers on an annual basis.

"I'm even more optimistic than that [goal], in that I'm pushing Atlantic Richfield, who will be leading the cleanup effort, to clean up even more yards," Western said. "The number we originally released officially is the 15-year timeline. I remain optimistic that we can beat that by quite a bit. If we get to as many as 300 or 350 yards a summer, we can accelerate that timeline even faster."

The newly proposed lead action level now enters a 30-day public comment period before being finalized, which will include a community forum at Montana Tech's Library Auditorium on Tuesday, June 16.