Columbia Falls Aluminum Co. has agreed to pay $57.6 million to clean up the former smelter site in Columbia Falls, according to a proposed agreement with the Environmental Protection Agency.

The cleanup plan includes placing a slurry wall of bentonite around the wet scrubber sludge pond and west landfill where leachate and spent pot liner from the plant was dumped for years.

Both areas have been found to be leaking high amounts of cyanide and fluoride into the nearby groundwater, though by the time the groundwater reaches the Flathead River, the concentrations have been shown to be greatly diminished, according to tests done by the company and vetted by the Environmental Protection Agency and state Department of Environmental Quality. 

The proposed consent decree marks a milestone. The property was listed as a Superfund site in 2016 and it has taken a decade to finalize the cleanup plan. 

In addition to the $57 million, Columbia Falls Aluminum Co. has also agreed to pay the EPA $1.8 million in past and future response costs and will also reimburse Montana for “any independent state future response costs incurred by the Montana Department of Environmental Quality.” 

The proposed agreement was filed with the U.S. District Court for the District of Montana and is subject to a 30-day comment period.

"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,” Cheryl Driscoll, president of CFAC’s parent company Glencore Ltd., said in a press release. 

In 2018, Columbia Falls Aluminum Co. filed suit against former plant owner Atlantic Richfield Co. in federal court in Missoula to recoup some of the projected cleanup costs. 

In 2021, Missoula District Court Judge Donald Molloy ruled Columbia Falls Aluminum Co. was responsible for 65% of the costs while Atlantic Richfield Co., which is owned by energy giant British Petroleum, was responsible for 35%. Columbia Falls Aluminum Co. disputed the ruling and filed an appeal in 2022.

Atlantic Richfield Co. is not named in the consent decree. The company is to reimburse Columbia Falls Aluminum Co. for its 35% share of the costs under the terms of the Molloy ruling.

From 1960 to 1980, Atlantic Richfield Co. disposed 129,000 to 135,000 tons of toxic spent potliner in unlined landfills, including 61,800 tons in the west landfill, Columbia Falls Aluminum Co. claimed. 

Atlantic Richfield Co., in court filings, did not dispute those figures. 

“As the district court found (and ARCO did not contest on appeal), ARCO’s spent potliner is the primary cause of groundwater contamination at the site. During that period, ARCO produced over 3.2 million tons of aluminum and generated $565 million in profits,” Columbia Falls Aluminum Co. attorneys argued in court filings. 

“Unlike ARCO, CFAC never placed spent potliner in unlined landfills. Instead, CFAC disposed of spent potliner in a lined landfill from 1985 to 1990 and shipped spent potliner offsite from 1990 onward, which seriously reduced contamination at the site,” Columbia Falls Aluminum Co. argued on appeal. “Indeed, compared to ARCO’s disposal of spent potliner, CFAC’s contribution to contamination was a drop in the bucket. It was undisputed at trial that ARCO contributed more than 50 times the amount of cyanide and fluoride into the Site’s groundwater that CFAC did.” 

In previous court arguments, Columbia Falls Aluminum Co. experts maintained its share of the cleanup of the west landfill and wet scrubber sludge pond should be about 10% and sitewide, a split of about 53% for Atlantic Richfield Co., and 47% for Columbia Falls Aluminum Co. 

Columbia Falls Aluminum Co. did admit that it dumped contaminated leachate into the wet scrubber sludge pond, which was also toxic. Molloy's opinion noted the leachate was untreated, unlike Atlantic Richfield Co.'s 91 million gallons of waste into the wet scrubber sludge pond, which was treated for cyanide and essentially inert. 

Molloy also found that Columbia Falls Aluminum Co. had an opportunity to clean up the cyanide and fluoride contamination in 1989 but decided to not apply for a government hazardous waste storage permit which would have opened it to more regulatory scrutiny and the cleanup costs. 

There was also the matter of profit over time and investment for both companies. 

Atlantic Richfield Co. expended about $1.1 billion over the course of owning the plant and made about $565 million in profit. Columbia Falls Aluminum Co. expended $95 million and made $1.1 billion. Of that profit, about $659 million was from selling electricity it had purchased on contract at wholesale rates back to the market during the 2001-02 West Coast energy crisis. Molloy discounted that amount, but still noted the company made about $279 million producing aluminum. 

Molloy also took into account indemnity clauses and other factors when Columbia Falls Aluminum Co. bought the plant in 1985 when determining the 65%-35% split. 

Columbia Falls Aluminum Co. argued that Atlantic Richfield should pay more and that Molloy’s ruling was arbitrary and capricious. The Ninth Circuit, however, upheld Molloy’s methods for parsing out the costs entirely and affirmed Molloy’s ruling in 2022. 

Outside of the landfills and contaminated areas, most of the property today has been sold to Columbia Falls developer Mick Ruis. The city recently approved a 400-plus unit subdivision on about 76 acres of land east of the former plant, which the EPA has said is safe for residential development. 

Ruis in total bought about 2,300 acres of land from the company. The plant was torn down years ago and Ruis has said in the past he hopes to attract new businesses to the site. It has railroad access and power nearby.