ACID MINE DRAINAGE

Penn Mine, Calaveras County, California

WEST personnel designed improvements and provided operations for the acid mine drainage (AMD) treatment system at the former Penn Mine site, located in the California foothills. The tailings associated with the operation of the abandoned copper mine resulted in discharges of acid and heavy metals. A treatment system was installed to provide pH control and removal of the heavy metals. The treatment system utilized calcium oxide for pH adjustment and heavy metal precipitation. WEST personnel designed improvements to the treatment system to enhance solids removal and system performance. These improvements included use of polymers, calcium carbonate, and Modifications to the process flow to enhance settling and reduce solids discharge to Comanche Reservoir. These modifications allowed for the discharge of the treated water in compliance with all regulatory requirements.