With a potential Superfund designation still on the table for the shuttered Columbia Falls Aluminum Co., officials with the U.S. Environmental Protection Agency are negotiating with representatives from the company to guarantee cleanup of the contaminated site.

The EPA proposed the listing on the National Priorities List in March, citing sampling that detected potentially hazardous levels of contaminants including cyanide, fluoride, arsenic, chromium, lead and selenium in surface water, groundwater and soils at and adjacent to the aluminum reduction plant’s campus. A listing would initiate the process of decontaminating the site and compelling the responsible parties to pay the costs.

The goal of the negotiations — begun about one month ago — is to agree on an administrative order of consent, which would include financial assurances that CFAC and its parent company, Glencore, won’t walk away from the cleanup process, federal oversight requirements, a work schedule and access to the site for the EPA to conduct monitoring of contamination within the proposed Superfund boundaries.

Speaking during a public meeting Wednesday night, EPA remedial site manager Mike Cirian told several dozen community members that the agency hopes to complete an agreement with the company by Thanksgiving.

“We got through a lot of [the negotiations] today,” Cirian told the audience members. “Toward the end of the month, we’re going to be meeting again by conference call to answer a few more of these items, and I think we’ll be pretty close.”

Stacey Schnebel, vice president of the Columbia Falls Chamber of Commerce, expressed concern with the stigma associated with Superfund-listed sites, and urged the agency to be clear that the designation would applies only to the aluminum plant site, rather than the town itself.

“What’s happened out there is important, but what’s happening now to more forward is more important,” Schnebel said. “The community itself is not a Superfund site, it’s a site on the edge of Columbia Falls.”

She also asked Cirian how the cleanup would be regulated if the EPA decides against a Superfund listing.

“That’s a ‘depends’ answer,” Cirian responded. “If we can come to an understanding with Glencore, and through the AOC (administrative order of consent) they agree everything we negotiated needs to be done, we may not need to go to a Superfund designation. ... [but] there will have to be financial assurances and other things in place.”

In 2014, the EPA completed a preliminary site assessment on the property, testing samples from soils on or adjacent to the plant and water from monitoring wells. But with only preliminary data available, little is known of the full extent of the contamination, and no estimate of the cleanup costs exists.

Several attendees asked whether the taxpayers would be on the hook for the costs of cleanup. Cirian said the agency would conduct interviews with community members, including former workers, and sift through company records to identify the parties responsible for contamination throughout the property.

He added that Libby’s Superfund designation resulted in a successful settlement from the responsible company that has covered all of its remediation to date, and that the agency had already notified past owners of the CFAC property, including Anaconda Co. and ARCO.

Cirian said if the EPA decides to list the site, the next step would be a more robust assessment, with additional wells and soil sampling sites included in the site investigation. Then a feasibility study would identify where on the site remediation would need to happen, and what the alternatives for cleanup are.

He said the site investigation could be undertaken throughout the winter, with cleanup beginning as soon as next year.

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.