Gold King Mine Accident Highlights Risks Posed by Abandoned Mines

On August 5, 2015, EPA personnel were working with a private contractor on a water quality project at the Gold King Mine near Silverton, Colorado. The intent of the project was to assess ongoing mine water leakage and to identify and evaluate options for additional mine water treatment and for reduction in the amount of mine water that flows into Cement Creek. In the course of this project, workers inadvertently damaged a tailings pond that had been built to slow and treat mine water outflow. This resulted in destruction of the pond and a discharge of over 3 million gallons of mine waste water and tailings into Cement Creek, a tributary of the Animas River.

Since this event, EPA officials have engaged in ongoing water quality testing and report that contamination levels in the Animas River have decreased to pre-spill levels. The Colorado Department of Public Health and Environment has reached similar conclusions and reports that the river has returned to “stable” conditions which means that that are no human health concerns during typical recreational exposure.

The Gold King Mine was abandoned in 1923, and according to the EPA, mine tailings were directly released into the creeks and rivers in the area until the 1930s. Prior to this 2015 accident, contaminated mine water flowed from this mine at a rate of approximately 7 gallons per minute. That rate briefly increased to more than 500 gallons per minute immediately following the accident. The EPA had previously sought to list the Gold King Mine and surrounding area as a Superfund site which would have provided additional funding for environmental remediation and clean-up. Community input, however, raised concerns about the effect of Superfund status on tourism. As a result, the EPA agreed to postpone seeking Superfund status for the site as long as measurable progress could be made to improve the water quality absent such status.

The accident at the Gold King Mine emphasizes the risks posed by the legacy of mines that were opened, operated and abandoned in the western U.S decades ago during a time when neither the technology nor the regulations necessary for effective water quality protection existed. The Gold King Mine is one of approximately 23,000 such abandoned mines in Colorado, 6127 of which have been reclaimed by the Colorado Division of Reclamation, Mining and Safety. The BLM lists 3400 abandoned mines on BLM-managed lands in Colorado. In the Upper Animas Watershed, where the Gold King Mine is located, there are approximately 400 abandoned and inactive mine sites. Numerous reclamation projects have been completed in that watershed over the last 20 years.

The BLM’s Abandoned Mine Lands Program was created in 1997 to reduce dangers to the public, public lands and the environment from health and other adverse impacts related to hard rock mines at which operations ceased prior to 1981. As of 2014, this Program had over 46,000 abandoned mine sites in its inventory. Of those, approximately one-quarter are remediated, are sites that do not require remediation, or are sites at which remediation actions have commenced.

These site clean-up and remediation actions on federal lands are governed by various federal statutes including the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the federal Clean Water Act (CWA), the Federal Land Policy and Management Act (FLPMA) and the National Environmental Policy Act (NEPA). The lack of a robust federal budget for clean-up of abandoned mine sites and the liability that can attach to non-government actors who attempt clean-up of mine sites has inhibited progress towards addressing this mining legacy in Western states.