EPA Superfund Site

COPPER BLUFF MINE

CA | EPA ID CAD980638225

About this site’s exposure pathways: As of December 2024, the Copper Bluff Superfund site is considered to Human Exposure Not Under Control. High concentrations of metals in the acid mine drainage and sediment are being discharged from the main mine tunnel (adit). This adit mine drainage is located along a highway with intermittent foot traffic. This exposure pathway is considered unacceptable based on EPA risk-based criteria because until this flow is controlled or treated, the human exposure potential will continue to exist for those individuals hiking in this area. Exposure through fish consumption is not expected to be significant because none of the metals (copper cadmium and zinc) found in the discharge bio-accumulate in fish at the concentrations and area of the River that is impacted by mine drainage. This site has recently been listed on the NPL and contracting and studies are under way to understand steps to control or treat the mine drainage.

Currently, the planned activities to address this pathway are development of a Remedial Investigation and Human Health Risk Assessment, which are currently underway. EPA currently anticipates that human exposure will be under control by 2028, because the Remedial Investigation and Human Health Risk Assessment should be completed by then.