Regional Water Quality Control Board, Region 5 (Central Valley), Sacramento
Walker Mine Pit Backfill Project
NOE - Notice of Exemption
The remediation project consists of filling in nine collapsed mine working pits with nearby soils and bedrock material. The goal of the project is to significantly reduce the volume of snowmelt which enters underlying mine workings of the abandoned Walker Mine and becomes acid mine drainage. Approximately 10 to 15 acres of land will be graded from nearby source areas.
RWQCB is implementing this project pursuant to its Cleanup and Abatement authority under Section 13304 of the Porter Cologne Water Quality Control Act. The project is designed to further mitigate the release and threat of significant releases of heavy metal laden acidic drainage from the underlying mine workings. The project will also reduce the physical hazard to wildlife and the public. The two project areas are located on gentle hill slopes approximately 3/4 of a mile and nearly 2 miles, respectively, from the Walker Mine portal and former mill site. The primary task consists of the filling of earth into previously excavated land with material compatible with the natural features of the site. Significant portions of the project areas are already disturbed by former mining activities. Some potential source areas are not fully disturbed but are not significant sensitive resources. Additional tasks include improving existing surface water diversion ditches. Based on information provided by the Plumas County Planning Dept. there are no recorded historical resources in either project area. The total cost of the project is estimated to be approximately $500,000.