EPA finalizes plan for Billings PCE Superfund site in Montana
Cleanup plan will address indoor air contamination and mitigate health risks
BILLINGS, Mont. – Today, U.S. Environmental Protection Agency (EPA), in partnership with the Montana Department of Environmental Quality (MDEQ), finalized the cleanup plan to address indoor air contamination at the Billings PCE Superfund site, marking a major milestone in the Superfund process.
The plan, informed by gold-standard science and community input, is to install mitigation systems in homes and businesses within the site boundaries to reduce exposure to harmful chemical vapors. This action is designed to prevent exposure to indoor air contamination and ensure the site remains protective of human health and the environment.
“Today’s decision sets a clear path forward to addressing contamination and protecting human health and the environment,” said EPA Regional Administrator Cyrus Western. “This plan reflects input from the Billings community, is grounded in science and marks a critical step in the Superfund process to ensure continued progress for Billings residents.”
EPA’s plan for Operable Unit 1, finalized in a document known as a Record of Decision (ROD), addresses PCE contamination by installing a system that consists of pipes and a fan that channel vapors from a building’s basement to the outside. These systems remove chemical vapors from indoor air and beneath building foundations, significantly reducing health risks associated with chemicals such as PCE. Under the plan, EPA will be responsible for the equipment and installation of the systems, while MDEQ will be responsible for long-term operation and maintenance of the systems. Building owners will cover the electricity cost, comparable to running a 75-watt lightbulb continuously.
EPA accepted public comments on the proposed cleanup plan during a 60-day comment period from July 28, 2025, through Sept. 27, 2025, and held a public meeting on Aug. 27, 2025, to present the proposal and gather public comments. EPA will continue to engage with the community and provide updates as the project moves forward.
The next phase of the process is remedial design, during which EPA will develop detailed engineering plans to implement the cleanup plan. Cleanup activities will begin after the design phase is complete.
Background
The Billings PCE Superfund site covers 1,100 acres and runs through several neighborhoods east of downtown Billings. The site was contaminated in the past with PCE and other chemicals from dry cleaners and other industrial sources. The chemicals from these businesses are in the soil and groundwater in parts of Billings. Chemical vapors can build up under building foundations and let small amounts of vapors into the indoor air. The mitigation systems vent these vapors outside the building, reducing the risk to people inside.
EPA’s formal response to public comments, additional background and site documents are available on the Billings PCE Superfund site profile page.