Assessing the Legacy of an Old Aluminum Smelter

The last step in figuring out how much damage the former Columbia Falls smelter has caused to nature is now ready. A plan written by state and federal agencies, the Confederated Salish and Kootenai Tribes, and other partners will examine the site again and decide how to repair or pay for long‑term harm. The team is looking beyond the tests already done by the EPA and CFAC. They want to see if “forever chemicals” – a group of hard‑to‑breakdown substances known as PFAS – are present. The original studies didn’t check for these chemicals, and a former plant engineer thinks the smelting process could produce them. Gathering old data is difficult, but once it’s collected it must be shared with the trustees who oversee Superfund projects. One focus of the new investigation is how groundwater and surface water interact. Staff will collect samples from seeps that feed into the Flathead River. Past tests have found high levels of cyanide and fluoride near old waste piles, but the river water itself shows lower contamination. The new work will confirm whether those numbers still hold. CFAC, the company that once owned the smelter, has not joined the damage assessment. In letters from March 2024 it said it was being asked only to pay, not to help. It also called the effort premature and outside its scope. Despite this, the assessment will move forward at a pace that balances speed with scientific rigor.The damage study is separate from the cleanup that starts in 2027. The cleanup will move contaminated soil to a landfill, build a slurry wall around the old sludge pond, and aim to stop cyanide from leaching into groundwater. That part is already approved by the EPA and will cost about $57 million. The damage assessment seeks to recover losses suffered by people, wildlife, and tribal communities. Past settlements in Montana have ranged into the millions and sometimes involve land swaps instead of cash. For example, a former mining company gave up 322 acres that became public parkland in Helena. The assessment does not affect plans to build new homes on the property’s east side, which a developer intends to turn into over 400 housing units. Nor does it directly address human health risks; those would be forwarded to the EPA if found. The next step is to review all data, find gaps, and quantify how much the natural environment has been harmed. The trustees will then decide on restoration actions that give back services to the public and, where possible, replace lost ecological or cultural benefits for tribal members.