EPA Orders Sunnyside Gold Corporation To Conduct Groundwater Investigation At Bonita Peak Mining District Superfund site

The U.S. Environmental Protection Agency (EPA) recently issued a unilateral administrative order to Sunnyside Gold Corporation to conduct groundwater investigation activities at the Bonita Peak Mining District Superfund Site (BPMD) in San Juan County, Colo. Sunnyside Gold is a current owner and past operator of the Sunnyside Mine in the BPMD.

“EPA remains committed to advancing the investigation and cleanup of historic mining impacts in the Bonita Peak Mining District,” said EPA Regional Administrator Doug Benevento. “The assessment of groundwater in the area is a fundamental step in identifying effective cleanup options for the site and improving water quality in the upper Animas River watershed.”

EPA issued the order to Sunnyside Gold Corporation to conduct a remedial investigation of the Bonita Peak Groundwater System, designated as Operable Unit 3, within the larger BPMD. EPA is ordering the company to complete this work so the agency can identify surface water impacts from the groundwater system, assess the condition of existing bulkheads associated with the groundwater system, determine the hydrological interconnection of the various underground mine workings, and evaluate potential cleanup options at this portion of the site.

It is anticipated that the RI will be conducted as an iterative fashion using adaptive management principles to identify opportunities for early or interim response actions as information and data is developed during the RI.

EPA’s order requires this work to begin in 2018, with some identified items being completed by the end of the year. The company has an opportunity to request a conference with the EPA to discuss the order before it becomes effective.

The BPMD became a Superfund site on Sept. 9, 2016, when it was added to the National Priorities List. The site consists of historic and ongoing releases from mining operations in three drainages: Mineral Creek, Cement Creek and Upper Animas, which converge into the Animas River near Silverton, Colorado. The site includes 35 mines, seven tunnels, four tailings impoundments and two study areas where additional information is needed to evaluate environmental and human health concerns.

On Dec. 8, 2017, EPA Administrator Scott Pruitt named the BPMD to a list of 21 Superfund sites across the nation which are receiving his immediate and intense attention. For more information, visit epa.gov/superfund/bonita-peak.