Holden Mine Remediation

The Holden Mine clean-up effort is the largest mine site cleanup on Forest Service managed property in the United States. Herrera prepared the site-wide Surface Water Pollution Prevention Plan (SWPPP) for the site located near Chelan, WA. The plan addresses surface water management for large scale CERCLA removal and cleanup within heavy metals contaminated areas. Primary concerns include controlling heavy metal mobilization, turbidity, pH, and uncontrolled discharges. The plan included thirty-one Best Management Practices (BMP) modified to address concerns with heavy metal discharges. Examples include: 1) high mountain native vegetation proven on mine site stabilization, and 2) construction sequencing, removal area size, and exposure timing coordinated with tailings redox. Site specific SWPPPs were prepared for each work area building upon remediation designs and construction work plans. The site specific SWPPPs combine BMPs, soils treatment, revegetation, and construction techniques to address hydrology, contaminated soils and mine waste. Record keeping, lessons learned, and water quality tracking are incorporated into an overall compliance program for the site. Water quality monitoring parameters include pH, heavy metals, and turbidity.