EPA expects proposed action on CFAC cleanup this fall
The red lines show a plume of pollution around the CFAC plant. It drops dramatically in concentration as it nears the Flathead River, preliminary tests have shown.
Hungry Horse News
The Columbia Falls Aluminum Co. Superfund timeline will enter a new phase in the coming months, project manager Ken Champagne of the Environmental Protection Agency said last week.
The EPA, with help from an independent contractor, will write a proposed action for cleanup of the former aluminum plant.
Much like an environmental impact statement, it will include several alternatives for ways to clean up the site, which has groundwater contaminated in some locations with cyanide and fluoride and soils that show contaminations with polycyclic aromatic hydrocarbons, commonly found in coal, oil and gas.
One of the main concerns is the groundwater near old dumps and ponds at what was once the north end of the plant. Some wells near those dumps show high amounts of cyanide and fluoride well above safe water drinking standards.
CFAC, through its contractor Roux Associates, recently released a formal feasibility study, which suggests the best way to clean up the site is to contain the landfills and ponds with a slurry wall — a wall of concrete that would be 3 to 6 feet thick.
The EPA and the state Department of Environmental Quality recently accepted that feasibility study and remedial investigation as part of the Superfund process.
The acceptance marked the completion of the Administrative Order on Consent — a legal document that laid out the steps the company needed to do to get to an eventual cleanup of the facility.
The company came in on budget and on time. The AOC was first agreed to back in 2016. Since then the plant has been torn down and a vast array of test wells, soil borings, and other tests have been conducted on the sprawling property.
There is a wrinkle in all of this, however. CFAC is suing former owner the Atlantic Richfield Co. in federal court, claiming ARCO should pay at least some of the cleanup costs because it dumped the waste in the first place. A bench trial is underway this week in federal court in Missoula in front of Judge Donald Molloy. That suit will likely determine who will pay the brunt of cleanup costs. The legal action is allowed under the Superfund law and it could impact the proposed action.
Once the proposed action is completed, it will go out for public comment.
After the comments are considered, the EPA will release a record of decision, which will outline the final remedy for the site. That should come in spring of 2022.
After that, a detailed cleanup plan is developed and implemented during the remedial design/remedial action stage. Remedial design includes development of engineering drawings and specifications for a site cleanup.
Remedial action follows design, and involves the actual construction or implementation phase of site cleanup.