The Environmental Protection Agency now formally proposes adding the Columbia Falls Aluminum Company to the National Superfund List.
That makes the former smelter eligible for additional study and cleanup resources.
Cyanide, fluoride and various metals have been detected in soils, surface ponds and groundwater at the now-closed Columbia Falls smelter. That's why city manager, Susan Nicosia, supports the EPA's proposal to add the site to its priorities list.
"Our main push for the city has been to maintain our clean water supply and to ensure the community's clean water supply is not impacted by the groundwater contamination at the site," Nicosia said.
Parent-company Glencore shuttered the smelter in 2009 and recently decided to permanently close it. Glencore opposes a Superfund designation saying it's a slow, stigmatizing process that hinders redevelopment.
EPA's proposal to add the smelter to its priorities list kicks off a 60-day public review and comment period that begins Thursday.