A Brief History

The Columbia Falls Aluminum smelter operated from 1955 – 2009. It was originally built and operated by the Anaconda Company to take advantage of cheap power from Hungry Horse Dam. By the late 1960s, the plant employed over 900 people and produced more than 1 million pounds of aluminum per day. Complaints about fluoride emissions harming wildlife, cattle, and air quality began to be raised. The Atlantic Richfield Company (ARCO) bought the plant in 1977, then sold it to private investors for $1 in 1985. The new company, Columbia Falls Aluminum Company (CFAC) ran the plant until 1999 when they sold to Glencore. After a decade running at reduced capacity, Glencore shuttered the mill in 2009, and closed it permanently in 2015. It was listed as a federal Superfund site in 2016.


The aluminum production generated mass amounts of solid toxic waste, as well as toxic air emissions. Approximately 40 toxic chemicals have been identified on the site. The most notable solid toxic waste is spent potliner, a carbon layer bonded to brick that builds up inside smelting pots and has to be periodically removed. The spent potliner contains cyanide, fluoride, sodium and aluminum. Cyanide and fluoride can leach into groundwater. Wet scrubber sludge, which is 80% calcium fluoride as well as other toxins, is another primary source of contamination.

Trace amounts of cyanide, suspected of originating from CFAC, was discovered by the EPA in two drinking wells in 2013 in the nearby Aluminum City neighborhood.

Waste Disposal

From 1955 – 1990, the toxic waste was buried in seven unlined landfills, or discharged into percolation ponds on site. After 1990, toxic waste was removed by the still-existing rail line for disposal in federally-certified hazardous waste landfills out-of-state.

The Reliable Parties

Two companies are fully reliable for the cleanup costs. The Columbia Falls Aluminum Company (CFAC) is responsible for 65% and Atlantic Richfield Company (ARCO) is responsible for the remaining 35%. CFAC is owned by Glencore, one of the largest commodity trading and mining companies in the world with revenues of $256 billion in 2022. ARCO is owned by BP PLC (formerly British Petroleum) one of the largest oil companies in the world with $241.4 billion in revenue in 2022.

The Proposed Plan

Consultants for CFAC conducted the feasibility study and wrote the proposed plan, which the EPA released for public comment in the summer of 2023. Their plan would leave all 1.2 million cubic yards of contaminants on-site. They propose to build a 3,700’ long slurry wall that is 100 – 125’ deep and 2’ – 3’ wide around the most contaminated area. A groundwater treatment facility would be built to treat any groundwater seeping beyond the slurry wall. Other contaminants would mostly be excavated and then re-buried in EPA-approved on-site repositories.

Problems with the Proposed Plan

The proposed plan disregards the community’s consistent desire for a comprehensive cleanup, a consideration the EPA is expected to prioritize. Rather than addressing this community preference, CFAC’s plan opts to leave all toxic waste on-site, risking contamination of nearby drinking wells and the Flathead River. The proposal also imposes perpetual restrictions on site usage. Concerns include unaccounted-for waste, technical doubts about the slurry wall’s effectiveness, and the indefinite maintenance burden of the water treatment facility and new waste repositories. Financing details remain unclear, and the feasibility study overlooks flood, seismic, and climate vulnerabilities, despite the site’s water proximity.

A Better Option: Remove the Waste

During the feasibility study, the company’s consultants inexcusably eliminated removing the waste as an option, saying it was too costly and that using trucks would disturb the community and visitors to Glacier National Park. They conveniently made almost no mention of the existing rail line nor the nearly two decades the company safely removed toxic waste by this rail line. The Coalition believes our community deserves to have the cost-benefits of a complete removal fully and fairly evaluated before a plan for cleaning up the site is approved. Only then can we be sure the cleanup truly protects our water, our health, our community, and our economy.

Next Steps

The EPA is currently evaluating the proposed plan as well as public comments received during the summer public comment period. The EPA is expected to make a decision about how the site will be cleaned-up in the coming months. It’s important to the health and future of our community and our river that they pause this process and order a fair and independent evaluation of the cost-benefits of removing the waste and restoring the site.