The U.S. Forest Service is working to plug holes and bury waste at a southern Arizona mine after orange sludge appeared downstream last year.
A storm in September of 2014 released heavy metals and iron from the abandoned Lead Queen mine site into the Harshaw Creek watershed, about six miles south of Patagonia, according to the Arizona Daily Star.
The Forest Service is putting waste rock into a contained underground area, covering it, and placing barriers to keep it in place. The cleanup is expected to be complete by February.
Patagonia Area Resource Alliance board member Carolyn Shafer says the Patagonia area is home to at least 130 abandoned mines. The alliance wants the abandoned mines cleaned up before any new mines begin operating.