EPA proposes lower residential lead cleanup level for Butte
EPA proposal lowers the existing residential cleanup level and initiates a 30-day public comment period
BUTTE, Mont. — Today, U.S. Environmental Protection Agency (EPA) is proposing changes to the residential cleanup level for lead and the size of the Butte Priority Soils Operable Unit (BPSOU). EPA’s proposal lowers cleanup level for lead in residential soil and interior dust to 456 parts per million (ppm) from the current cleanup level of 1,200 ppm. EPA is also proposing expanding the BPSOU boundary by approximately 3,637 acres to include an additional 7,100 homes.
Cleanup at the BPSOU will continue under the current plan while the agency’s proposal goes through public comment and finalization.
"Today marks a major step forward toward reducing lead exposure in Butte and delivering lasting results for the community," said EPA Regional Administrator Cyrus Western. "In the proposal, EPA is establishing a clear, accelerated cleanup approach and collaborating early with state and local partners to provide multiple layers of protection for children and families."
In October 2025, EPA released the Residential Soil Lead Directive for CERCLA Sites and RCRA Hazardous Waste Cleanup Facilities (2025 Directive). The 2025 Directive streamlines response actions by setting a single regional screening level of 200 ppm and a single target blood-lead level of five micrograms per deciliter, enabling faster decisions that are built to quickly address risks posed by lead in residential soil and interior dust. The 2025 Directive evaluates and incorporates site-specific conditions to develop and select protective cleanup levels, which will help accelerate cleanups and deliver health and environmental protections to communities.
Residences with the most vulnerable populations, including those with young children and pregnant and nursing mothers, are currently prioritized under existing cleanup protocols and will continue to be prioritized in EPA’s new proposal.
The proposed changes modify the existing cleanup plan outlined in the 2006 Record of Decision (ROD), which was later modified by the 2011 Explanation of Significant Differences (ESD) and the 2020 ROD Amendment (RODA). If finalized, residential properties within the current BPSOU boundary would continue to be sampled and evaluated to determine whether cleanup is needed. Properties previously sampled but not warranting cleanup under the former 1,200 ppm cleanup level would also be reevaluated to determine if cleanup is needed. Mandatory sampling, evaluation, and any necessary cleanup of residential properties within the expanded BPSOU boundary is anticipated to take approximately 15 years from 2026.
EPA’s proposal will undergo a 30-day public comment period, which will run from June 1 through June 30, 2026. A formal public meeting where verbal public comments can be submitted for the record will be held on Tuesday, June 16, from 6-7 p.m. in the Library Auditorium at Montana Tech. A stenographer will be present to record public comments. Hybrid joining information will be made available on the Butte community engagement calendar. Community members joining in-person are also invited to attend an open house from 5-6 p.m. in the gathering area outside the library auditorium.
While verbal public comments can only be submitted at the formal public meeting, written public comments will be accepted throughout the public comment period. Please submit comments via email to EPAButtePPcomments@epa.gov or U.S. mail through June 30, 2026.
U.S. Environmental Protection Agency
ATTN: Butte Superfund Site Team
10 W 15th Street, Suite 3200
Helena, Montana
59626
Following the conclusion of the public comment period, EPA will consider all public comments and provide responses in a formal Responsiveness Summary in the Record of Decision Amendment.
EPA’s proposal is available for review on the Butte website along with a fact sheet explaining the proposed changes. The supporting Administrative Record is also available for review.
These documents will also be available for review at the library at Montana Tech (1300 W Park Street, Butte, Montana) and at EPA’s Helena office (10 W 15th Street, Suite 3200, Helena, Montana).