Columbia Falls Aluminum Corporation, LLC Agrees to $57 million cleanup of former smelter site in Montana
COLUMBIA FALLS, Mont. -- U.S. Environmental Protection Agency (EPA) announced today that Columbia Falls Aluminum Company, LLC (CFAC) has agreed to clean up contamination at the Anaconda Aluminum Company Columbia Falls Reduction Plant Superfund site near Columbia Falls, Montana (also called the CFAC site).
CFAC agreed to pay past response costs and implement multi-million-dollar cleanup actions at the site. Today’s announcement marks a major step forward in the Superfund cleanup process at the site, ushering in the next stages of implementation and environmental protection.
Under the proposed consent decree, EPA and the Montana Department of Environmental Quality (DEQ) will oversee the design and the implementation of remedial activities to address arsenic, cyanide, fluoride, and polyaromatic hydrocarbon (PAH) contamination. The cleanup activities are outlined in the Record of Decision (ROD), which was signed by EPA and DEQ in January 2025.
“This consent decree represents a significant milestone on the path to successful cleanup and redevelopment,” said EPA Region 8 Regional Administrator Cyrus Western. “In coordination with our federal, state, local, and industry partners, EPA is advancing effective, protective solutions that safeguard human health and the environment.”
After the public comment period and court approval of the proposed consent decree, CFAC will design and implement the cleanup work, known as the remedial design/remedial action under EPA and DEQ oversight.
“In partnership with EPA, we are excited to announce this consent decree, allowing for the successful cleanup and redevelopment of the Columbia Falls Aluminum Company Superfund site,” said Montana DEQ Director Sonja Nowakowski. “We are happy that we continue to work with the EPA and the community to ensure this work will protect the Flathead River and Columbia Falls.”
"The start of active cleanup activities is a positive step toward addressing environmental impacts at the site and reflects a shared commitment by CFAC and local, state, and federal partners to position the area for long-term and sustainable reuse,” said Cheryl Driscoll, President of CFAC’s parent company Glencore Ltd.
Site Background
The area, also called the Anaconda Aluminum Co. Columbia Falls Reduction Plant Superfund Site, operated from 1955 to 2009. The aluminum smelting process created significant amounts of spent potliner material that was stored in unlined landfills near the former smelter building. Over time, arsenic, cyanide, and fluoride leached out of potliner material stored in two areas of the Site and into the groundwater. Other areas of the site were contaminated with PAHs from the aluminum reduction process.
To address these issues, CFAC will implement cleanup actions such as low-permeability caps on landfills and the construction of a slurry wall to fully encompass the main source of groundwater contaminants. This slurry wall will prevent further contamination of the groundwater, stop the migration of contaminants toward the Flathead River, and bring seeps along the Flathead River into ecological compliance. CFAC will carry out these actions under EPA and DEQ oversight.
Cleanup actions were selected by EPA in consultation with DEQ in the ROD, which followed a Proposed Plan released in 2023. Significant community engagement activities, such as a public comment period, public meetings, and the development of materials like newsletters and fact sheets accompanied this Proposed Plan. After the public comment period ended, EPA engaged in significant additional community engagement activities, such as public meetings, the development of fact sheets, and technical assistance support.
The proposed consent decree was filed with the U.S. District Court for the District of Montana and is subject to a 30-day comment period. The complaint and the proposed consent decree are available on the Department of Justice’s Proposed Consent Decree webpage.
DEQ is separately required to put the proposed consent decree out for public comment. This will be available on DEQ’s website.
More information on the site is available on the Anaconda Aluminum Co Columbia Falls Reduction Plant Superfund (also called the CFAC site) site profile webpage.