On August 5, 2015, the EPA triggered a massive release at the Gold King Mine in San Juan County, Colorado that caused three million gallons of heavily mineralized water to be discharged into Cement Creek, which enters the Animas River near the Town of Silverton, Colorado. Shortly after the EPA triggered the release, to obscure and limit its own liability, the EPA created what it called the Bonita Peak Mining District (BPMD)—surrounding the Gold King Mine—and designated the BPMD and 46 specific mine sites and two study areas as Superfund sites. The EPA has studied this area for years but has always concluded that sites within the so-called BPMD did not warrant inclusion on the National Priorities List as established by Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).
Sunnyside Gold Corporation is a small corporation that owns former mining claims and other real property in the Animas River Valley, in San Juan County, Colorado. As a result, its properties are within the BPMD. As of 1991, all mining ceased on Sunnyside’s properties and Sunnyside immediately began reclaiming its sites, working with the Colorado Water Quality Control Division to complete its reclamation activities. In 1996, Sunnyside entered into a consent decree, reviewed by the EPA and approved by a Colorado district court, which required Sunnyside to complete specific remediation actions on its sites. In 2003, Sunnyside had fulfilled all of its reclamation duties under the consent decree. After the consent decree was terminated, Sunnyside continued voluntarily reclaiming its sites and other surrounding properties, which are monitored by all stakeholders, including the WQCD, the State of Colorado, the U.S. Bureau of Land Management the U.S. Forest Service, local governments, and the citizen formed Animas River Stakeholders Group. The State of Colorado and local governments opposed past efforts by the EPA to add any sites in the Animas River Valley to the NPL. The town of Silverton, for example, relies on tourism to support its economy and believes that tourists would avoid Silverton if nearby land were a Superfund site.
After the EPA made its designation in the Federal Register on September 9, 2016, Sunnyside filed a petition for review on December 8, 2016, in the U.S. Court of Appeals for the D.C. Circuit.
On April 26, 2017, MSLF filed a friend of the court brief in support of the Petitioner arguing that the designation violates federal law, federal regulations, and a ruling of the Supreme Court of the United States. On April 19, 2017, Sunnyside filed its opening brief. On July 10, 2017, the EPA filed its answer brief. Oral argument was held on February 20, 2018.