Residents still skeptical of CFAC cleanup after tour

Busloads of people toured the Columbia Falls Aluminum Co. Superfund site on June 12 as the company and government officials explained how a slurry wall containment system might work at the site.

They’re fields of grass now, but years ago, the wet scrubber sludge ponds and the west landfill were dumps for tons of waste potliner and water from about 1965 to 1990.

The two sites are joined at the hip. About 50 acres total, the west landfill is perched just above the sludge ponds.

“They are a source of contamination of ground water,” Dick Sloan of the Montana Department of Environmental Quality told the crowd.

A plume of groundwater contaminated with cyanide and fluoride, which leach from the potliner, spreads to the south from the dumps.

Potliner is the brick that was used to line the pots the aluminum was smelted in at the plant. The massive 40-acre building had dozens of large pots and the liners had to be replaced regularly. For years, potliner wasn’t even considered hazardous waste, but after a series of lawsuits in the 1980s, spent potliner was reclassified as such in 1988.

The state first found cyanide and fluoride leaching into groundwater at the Columbia Falls Aluminum Co. in the early 1990s. The two contaminants continue to leach into groundwater to this day from the above-mentioned dumps.

“Fortunately, [it] hasn’t reached the [Flathead] River in terms of impacting the river,” Sloan said.

Test wells near the river show very low levels of cyanide or non-detects altogether. Test wells near the dumps, on the other hand, show levels well above safe drinking water thresholds.

Sloan explained the strategy for cleaning up the dumps comes in the form of a slurry wall that will surround them. It will be about three feet thick, made of bentonite, soil and possibly cement, and will run about 100- to 125-feet deep. The idea is to contain the wastewater behind the wall as well as put monitoring wells inside and outside of it to determine if it’s working.

If it’s not working, a second cleanup, called pump and treat, would pump up the groundwater, treat it for cyanide and fluoride and then re-inject it back into the water table.

But there were skeptics of the plan. People questioned how a slurry wall would stop the dumps from leaking from the bottom. Sloan said test wells at the site indicate the contaminants are in groundwater that’s fairly shallow, about 60 feet or less.

Another layer below that is considered an “aquitard” — soils that keep the shallow groundwater and deep aquifers separate.

“None of the deep wells show any contamination,” Sloan told the crowd.

But folks still thought there should be more soil and other geological testing before work commenced and a Record of Decision is signed.

“There will be opportunity for public input in the design phase,” Sloan noted.

The aforementioned dumps aren’t the only concern, another area called north percolation ponds are also a problem. Soil from them will be dug up and placed in one of the landfills onsite, most likely an industrial landfill that already exists.

The Record of Decision is the Enviornmental Protection Agency’s legal document that outlines a cleanup plan for the site.

It was expected in March. Now the hope is it’s out by the end of the calendar year, EPA project manager Matt Dorrington said. The document, which could be changed, has been submitted to EPA Region 8 Administrator K.C. Becker.

Mayre Flowers, of the Coalition for a Clean CFAC said the tours were helpful and she appreciated the company hosting them. But like many others, she still has questions as the Record of Decision looms.

The coalition has recently been meeting with Karmen King, a scientist with Skeo, under an EPA-funded Technical Assistance for Communities grant.

King previously gave the community recommendations on the cleanup when the proposed action was first released. Now she is working with the coalition, helping them find key data points in volumes of technical documents that are hundreds of pages long.

The coalition will eventually hire its own independent analyst under another EPA program called Technical Assistance Grant, which is designed to help communities during the Superfund process.

Whether any of this will result in substantive changes to the cleanup plan remains to be seen. Many locals want to see the waste dug up and hauled away permanently.

But the EPA and the company note that they could probably never get it all and it would take hundreds of railcars to haul it out to an approved landfill in Oregon. Cost is also a factor, as the estimated price tag for removal would be about $623 million to $1.4 billion.

Removing the waste would also create a huge hole, EPA officials have said in the past.

Still, few residents are all that happy about the potliner and other waste being there forever.