From The Denver Post (Kirk Mitchell):
The Environmental Protection Agency has sued a mining company operating in Mineral County in federal court to recoup hazardous waste cleanup costs.
The U.S. sued Coca Mines Inc. for cleanup of hazardous substances in the Nelson Tunnel and the Commodore Waste Rock Pile Superfund Site.
The superfund site is in the San Juan Mountains less than 2 miles from the town of Creede. Shafts were dug in a series of hard-rock silver mines operated between 1889 and the 1980s tapping the “Amethyst Vein.” Horizontal tunnels also were bored, including the Nelson Tunnel.
The Nelson Tunnel is partially collapsed but continues to drain acid runoff.
The Commodore Waste Rock Pile, just outside the entrance of the Nelson Tunnel, included a water conveyance system that failed around 1995, releasing mine waste containing heavy metals including arsenic, cadmium, lead, manganese and zinc into West Willow Creek.
The creek flows into the Rio Grande River 4 miles below the site.
In 2008 and 2009, the EPA conducted waste removal studies at the waste pile site.
The EPA is now in the process of completing a feasibility study of remedial actions for the site.
Through June 30, 2015, the EPA incurred nearly $10 million in costs. Some of those costs were covered by the Asarco Environmental Trust.
The lawsuit says the discharge each day from the Nelson Tunnel into Willow Creek carries 375 pounds of zinc, 1.37 pounds of cadmium and 6.39 pounds of lead. Zinc levels have hit 25,000 parts per billion, hurting fish reproduction for more than 4 miles down to a confluence with the main stem of the Rio Grande, where dilution eases the impact.