DENVER (AP) — A Colorado mine that spewed 3 million gallons of contaminated wastewater into rivers in three Western states was designated a Superfund site Wednesday, clearing the way for a multimillion-dollar federal cleanup. The U.S. Environmental Protection Agency added the inactive Gold King Mine and 47 other nearby sites to the Superfund list. It also included nine other sites in eight states and Puerto Rico. The Colorado Superfund designation is the beginning of a years-long effort to clean up the wreckage of a once-booming mining industry in the San Juan Mountains in the southwestern corner of the state. Abandoned mining sites send millions of gallons of acidic wastewater to creeks and rivers every year. “What a great benchmark for this community and for our downstream partners, that we got listed,” said Bill Gardner, town administrator for Silverton, a mountain village not far from the Gold King. A federal crew inadvertently triggered the Colorado spill during preliminary cleanup work at the gold mine on Aug. 5, 2015, sending out a mustard-yellow plume that tainted rivers in Colorado, New Mexico and Utah.