The Columbia Falls Aluminum Company announced Tuesday that it recently met a “major milestone” by submitting three draft reports assessing contamination at the shuttered aluminum reduction facility near the Flathead River, one of which shows no impact to the human health of neighbors.
Submission of the reports to the U.S. Environmental Protection Agency (EPA) and Montana Department of Environmental Quality (DEQ) keeps the project on track to meet the agreed-upon schedule between the two regulatory agencies, CFAC and the environmental firm it hired to study the site, according to John Stroiazzo, CFAC project manager.
He said the company has gone “above and beyond” in its pledge to pay for costs associated with investigating the property, which is entering its third year on the federal Superfund program’s National Priorities List.
“We are pleased to keep moving this project forward,” Stroiazzo said. “We have a dedicated team and regulatory agencies who are keeping to their commitment. That means a great deal to this project and to getting the work completed.
“This portion is critical to understanding the big picture of the site,” he added.
Since 2015, workers have been painstakingly dismantling the shuttered aluminum plant, which was declared a Superfund site — one recognized by EPA as among the most contaminated in the country — in 2016.
During demolition, more than 29,000 tons of hazardous waste has been removed from the site and more than 131,000 tons of material (metals and carbon) have been recycled. Demolition work was conducted by Calbag Resources under the supervision of the DEQ.
In addition to the demolition, Roux Associates, with oversight from the EPA and DEQ, conducted a Remedial Investigation/Feasibility Study to identify contaminated areas at the site. Since 2016, Roux staff monitored the groundwater through 64 wells and collected more than 900 samples of soil/sediment, groundwater and surface water.
The three draft reports totaling more than 17,000 pages each are: the Phase II Site Characterization Data Summary Report; the Baseline Human Health Risk Assessment; and the Baseline Ecological Risk Assessment.
The data presented in the three reports is a major component of the overall risk evaluation of site conditions and will be used to support the feasibility study process, Stroiazzo said.
The Human Health Risk Assessment preliminarily confirmed that constituents from the site do not impact neighbors or others off-site, he said.
The Ecological Risk Assessment preliminarily indicates some potential, theoretical impact from the site to the backwater seep area of the Flathead River immediately near the site but didn’t show any actual impact to organisms and also determined that the area has limited fish habitat. The Ecological Risk Assessment did not show any impact to the rest of the Flathead River from the site.
The EPA and DEQ now begin review of the three reports and will provide comments to the CFAC team after the review is complete. Report details will be shared with the panel once agency review is complete.
The Phase II Site Characterization Data Summary Report outlines findings from data collected during sampling conducted in 2018. This information was combined with the data found in the Phase I work to create a comprehensive understanding of site conditions. The report is a requirement of the Remedial Investigation and Feasibility Study (RI/FS) discussed during various panel meetings, with the most recent presentation given in October 2018.
As Phase I indicated, Phase II preliminarily confirms several site facts:
Groundwater flow is south-southwest and toward the Flathead River during all seasons and flows away from Aluminum City; the highest concentrations of cyanide and fluoride were observed by the legacy landfills, indicating that these landfills are the primary source of cyanide and fluoride in groundwater; polycyclic Aromatic Hydrocarbons were detected at the site, most frequently in surface soil samples, and at the highest concentrations around the main plant and operational areas of the site.
The reports are subject to review by the EPA and DEQ, which may issue the final reports later this year.