EPA has issued a Superfund record of decision (ROD) calling for the responsible parties to spend at least $500 million to clean up the Molycorp. Inc. mine site near Questa, New Mexico. The site, which is owned by Chevron Mining, Inc., consists of an operating mine and milling facility, a tailings pile, and a tailings pipeline running from the mill to the pile.
Contaminated material includes about 328 million tons of acid-generating waste rock, more than 100 million tons of tailings, and acid-rock drainage at the mine and tailings pile. The ROD requires Chevron Mining to excavate contaminated soil and waste rock from the site and to intercept water draining from waste rock piles and treat the water.