The Columbia Falls Aluminum Company has entered into an agreement to expedite one portion of its extensive remediation project at the former aluminum-processing site along the Flathead River.
CFAC signed the administrative settlement agreement and order on consent (ASAOC) with the EPA on July 21, which calls for an early-action step to remove sediment and soil from the south percolation ponds and to restore a section of diverted river to its natural channel.
Initial work for this phase of the project, involving excavators scraping sediment from the pond bottoms and trucking it out, is expected to begin this fall, with the second phase slated for 2021.
“This is a positive, proactive step to remove impacted sediments and restore the natural course of the Flathead River,” CFAC Project Manager John Stroiazzo said. “From the data collected at the site, we know this is necessary. We were in a position to do the work now, and the agency supported that proposal.”
Stroiazzo said the agreement allows the work to move forward before the completion of the overall remediation’s feasibility study, anticipated to be finalized next year, after which the Environmental Protection Agency will issue its record of decision to define the scope of the cleanup. CFAC says the agreement accelerates the pond work by two or more years.
The ASAOC is similar to an earlier one that CFAC signed with the EPA to conduct a remedial investigation and feasibility study. The EPA, with consultation from the Montana Department of Environmental Quality (DEQ), is the lead agency for environmental assessment and cleanup of the site.
Previous work at the site included the demolition of most buildings onsite, including the main processing plant, and removal of waste, as well as cleanup of debris and equipment, which was completed in 2019, Stroiazzo said.
The EPA declared the aluminum-processing property a Superfund site in 2016.
The DEQ announced in September 2018 that CFAC and contractor Calbag Resources had resolved potential hazardous waste violations at the pot room building, satisfying a 2015 administrative consent order. More than 400 million pounds of waste was removed, including solid waste, asbestos, hazardous waste, universal waste, and reused and recycled waste, which the DEQ called a “milestone” at the time.
The resolution of the order was separate from the overall Superfund work and did not relieve CFAC of liabilities associated with the other aspects of the extensive project.
The pot room building contained 451 aluminum reduction cells, each weighing approximately 60 tons and containing materials derived from spent pot liners that were considered hazardous waste. Spent pot liners were listed by the U.S. Environmental Protection Agency in 1988 as hazardous waste because they contain toxic fluoride and cyanide compounds that can leach into the water.
Five smaller structures remain onsite, Stroiazzo said, including three warehouse facilities, a fabrication shop and an administrative building.
The early-action work beginning this fall and continuing in 2021 will remove sheet pile and riprap, installed in 2016 and 2018 to divert the river and protect the ponds from erosion. It will also include closing piping that allows stormwater into the percolation ponds and placing the removed soil and sediment from the ponds into an existing repository on the north end of the site.
CFAC says the actions will “remove the potential for future erosion of the South Pond structures and eliminate the risk for impacted sediment to reach the river.” Scoping and engineering work are underway, with fieldwork expected to start in October.
The south ponds were originally formed in the 1960s by installing a dam and infrastructure to close off a northern side channel of the Flathead River. The ponds were used as percolation ponds throughout the operational history of the site and now receive site storm water, according to CFAC.
“We are pleased to keep moving this project forward,” Stroiazzo said. “We have a dedicated team working with responsive regulatory agencies; both are fulfilling their commitments. That means a great deal to this project and to getting the work completed.”
In 2018, CFAC sued former aluminum plant owner Atlantic Richfield Company (Arco), arguing that Arco bore responsibility for contributing to the costs of cleaning up decades of contamination that occurred at the site.
Arco asked the court to stay the case until the EPA’s record of decision. Then, last week, Arco filed a motion requesting partial summary judgment on three of CFAC’s claims and summary judgment on two others.
As the lawsuit plays out in U.S. District Court, Stroiazzo said parent company Glencore, which purchased CFAC in 1999 and shuttered the plant in 2009, has solely funded remediation costs to date, including funding the remedial investigation and feasibility work, as well as financial assurance to guarantee the work to the EPA.
“We have also funded demolition work that was not part of the EPA mandate,” Stroiazzo said. “We took it upon ourselves to do the demolition work and clean up the site. We’re paying the bills.”
CFAC has not yet responded in court to Arco’s request for partial summary judgment, but Stroiazzo said the company disputes Arco’s assertion that the court can’t equitably allocate remediation costs until the record of decision.
“We don’t agree with that,” he said. “The way these things are done, you don’t have to know what exactly the dollars are because it’s a percentage basis. We think it should go ahead and responsibility should be determined now.”