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Case Summary: EPA Recovers $6 Million for Costs to Cleanup Colorado Abandoned Hard Rock Mine Site

On June 15, 2016, an agreement between the U.S. Environmental Protection Agency (EPA), Department of Justice (DOJ) and the state of Colorado with CoCa Mines, Inc. (CoCa), was approved that settles the company's liabilities at the Nelson Tunnel/Commodore Waste Rock Superfund Site (Site) by paying $6 million in past cleanup costs.

EPA’s Superfund program is currently evaluating alternatives for treatment of the Nelson Tunnel drainage to reduce heavy metal loading into West Willow Creek in order to improve aquatic conditions in the creek and downstream in the Rio Grande. The money recovered from CoCa is contained in a special account to fund future cleanup work at the site.

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Information about CoCa Mines, Inc.

Minerals Engineering Company (MECO), CoCa’s predecessor, mined the Amethyst, OH and P veins from 1972 until 1976, using the Commodore 5 tunnel adit that is located at the Commodore Waste Rock Pile. MECO continued operations as a joint venture partner with an exploration company from approximately 1982-1989. CoCa is liable as a successor to MECO for the operations conducted between 1972 and 1976 and for the joint venture operations between 1982 and 1986. CoCa is also directly liable for the activities conducted by the joint venture between 1986 and 1989. CoCa is a wholly owned subsidiary of Hecla Limited.

Information about the Nelson Tunnel/Commodore Waste Rock Pile Superfund Site

The Nelson Tunnel/Commodore Waste Rock Pile Superfund site is located on West Willow Creek, approximately one mile upstream of the City of Creede, in Mineral County, Colo., in the San Juan Mountains. The site is nestled in the Creede Mining District where historical mining operations provided economic viability to the area beginning in the late 1800s.

The site is an abandoned hard rock mine site that includes the Commodore Waste Rock Pile, which consists of approximately 200,000 cubic yards of formerly unstable mineralized waste rock that was the subject of a removal action completed in 2010. The site also includes the Nelson Tunnel, which discharges approximately 300 gallons per minute of metals contaminated surface water (200 lbs zinc/day) directly into West Willow Creek.

Fishing is an important part of recreation for visitors and locals in Creede, Colorado. Fisheries have been impacted and no fish exist for approximately two miles below the site. Further downstream, fish are sparse and appear to be suffering from reproductive effects of metals contamination. Willow Creek is a tributary of the Rio Grande River, a state-designated Gold Medal Fishery.

The EPA added the site to the National Priorities List on September 3, 2008. For more information, visit the Nelson Tunnel/Commodore Waste Rock Pile Superfund site profile sheet.

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Information on pollutants and environmental effects

The EPA’s work at the site will address the ecological risk to aquatic and terrestrial receptors as well as the human health risk to individual from dermal contact with waste rock, soil or surface water, or by inhaling contaminated dust. The primary contaminants of concern at the Site are arsenic, manganese, lead and zinc.

Contact information

For more information, contact

Laurianne Jackson
Enforcement Attorney
(303) 312-6950

Joy Jenkins
Remedial Project Manager
(303) 312-6873

U.S. Environmental Protection Agency
Region 8
1595 Wynkoop Street,
Denver, Colorado 80202

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