A Colorado mine that spilled 3 million gallons of contaminated wastewater into rivers in three Western states has been designated a Superfund site.
The U.S. Environmental Protection Agency's action Wednesday clears the way for a multimillion-dollar federal cleanup of the Gold King Mine and 47 other nearby mining-related sites.
The EPA also added nine other sites in eight states and Puerto Rico to the Superfund list.
A federal crew inadvertently triggered the Colorado spill during preliminary cleanup work at the inactive mine in August 2015, tainting rivers in Colorado, New Mexico and Utah.
The spill released metals including arsenic, cadmium, copper, lead, mercury, nickel and zinc.
The Superfund designation comes after months of negotiations with southwestern Colorado residents, who feared it could dampen the region's vital tourism industry.