By Steve Fiscor, Editor-in-Chief, E&MJ

As close to the end of President Barack Obama’s term as possible, the U.S. Environmental Protection Agency (EPA) conveniently issued its final report for the Gold King mine release — the largest mining-related environmental disaster in the U.S. in recent memory. On August 5, 2015, Environmental Restoration, a contractor working on behalf of the agency to investigate and address contamination from abandoned hard rock mines in San Juan County, Colorado, accidentally released 3 million gallons of water from the Gold King mine into the upper portions of Cement Creek, which fouled waterways as far away as Lake Powell in Utah and perhaps further.

The report provides the agency’s interpretation of pre-existing river conditions, the movement of metals related to the Gold King release through the river system, and the effects of the release on water quality. Amazingly, the research supports the EPA’s earlier statements that water quality returned to the levels that existed prior to the release. “While data indicate that water quality has returned to pre-event conditions, the EPA is committed to continue our work with states and tribes in the river system affected by the Gold King mine release to ensure the protection of public health and the environment,” said Dr. Thomas A. Burke, science advisor and deputy assistant administrator of the EPA’s Office of Research and Development.

In an effort to minimize the damage the agency inflicted on the environment, the report compares the total amount of metals entering the Animas River following the release with the average amount of metals generated by acid mine drainage from the Gold King mine and carried by the river in one to two days of high spring runoff. The report did note that the concentrations of some metals in the yellow plume that polluted the waterway all the way to Lake Powell were “higher than historical mine drainage.” The report said metal concentrations within the plume decreased as they were diluted by river water and as some of the metals settled to the river bed, justifying EPA Administrator Gina McCarthy’s ridiculous statements during the event regarding the waterway’s self-healing abilities.

The agency said there were no reported fish kills in the affected rivers, and post-release surveys by multiple organizations have found that other aquatic life does not appear to have suffered harmful short-term effects. The concentrations of metals in well-water samples collected after the plume passed did not exceed federal drinking water standards. No public water system using Lake Powell as a source of drinking water has reported an exceedance of metals standards since the release.

The final report can be found here. 

The report’s executive summary here.