CFAC report reveals hot spots of cyanide at the old landfills, dumps
Flouride, cyanide and arsenic are the main pollutants at the Columbia Falls Aluminum Co. plant, a report of environmental consulting firm Roux Associates has found.
The results come as no surprise to people familiar with the plant, though they are giving insight into the extent of contamination at the 960-acre Superfund site. All told, Roux did hundreds of soil samples, drew water from 60 different wells and took surface water samples from nearby creeks, ponds and the Flathead River.
Initial tests have found that 75 percent of the groundwater samples site-wide contain cyanide with 21 samples having levels that exceeded state standards for safe drinking water. Flouride is also a problem on the site, with flouride detected in 95 percent of the groundwater samples, though only seven were above the safe water drinking threshold.
Arsenic was frequently detected in soil samples, though only two wells had levels above the safe water drinking threshold. Arsenic, however, is also usually found in mountainous terrain more than other areas of the country.
The report noted that cyanide was found in the highest levels downstream from the plant’s west landfill and the former wet scrubber sludge pond. The same held true for flouride.
Another hot spot was an area known as the former drum storage area. A monitoring well in that area found the highest concentration of cyanide on the site, at 7,320 micrograms per liter. The state safe water drinking threshold is, by contrast, 200 micrograms per liter.
The contamination, even after a very wet fall, appears to be staying on the site, however.
“Cyanide concentrations are non-detect in all groundwater samples from monitoring wells bordering the western boundary of the site in the vicinity of Aluminum City,” the report noted.
The same held true for flouride, the report noted.
The tests also revealed, not surprisingly, high levels of aluminum in soil samples as well. The plant ran from 1955 to 2009 and closed permanently in 2015.
CFAC is financing the testing and remedial investigation of the site, having posted a $4 million bond to cover the work. The Environmental Protection Agency is overseeing the work and will do some testing of its own this June, independent of Roux’s results.
Roux’s initial report is 7,000 pages long, though most of it is tables and well logs.
Testing will continue this spring and into June. The goal is to have a feasibility study of how best to clean up the site by 2021. Roux will present the report at the next CFAC community liaison panel scheduled for Wednesday, April 19, 2017 at a location to be announced.
An EPA toxicologist will also be attending the meeting.
The full report can be downloaded at www.rouxinc.com.
“We now have completed the first step of this overall process,” CFAC project manager John Stroiazzo said in a release. “Along with the demolition of the buildings and the removal of materials from the site, people are seeing progress. We are doing what we committed to do and remain dedicated to completing the remedial investigation-feasibility study work.”