The Cactus Mine site gold deposits are located in the Soledad Mountain Mining District were developed by a series of mining companies including Cypress Gold and Hecla Mining Company over a period of time extending from the 1940’s to 1990’s. A large open pit, heap leach gold deposit was developed at the site. The voluminous quantity of mine tailings were produced as a result of the development of the heap leach open pit mine.
Approximately +12 million tons of mine tailings were generated by mining operations. These mine tailings have discharged from the graded slope and drain side slopes on the west side of the mine and onto the alluvial fan surface, due to erosion from storm events since the mine had ceased operations. The Cactus tailings contain highly elevated levels of arsenic.
Significant potential human health risks to the community and regional environmental impacts may have resulted from release of arsenic-bearing tailings into the waters of the state and airborne sources. The Cactus Mine has been designated as an AML CERCLA site. Soil and sediment sample results indicate that elevated arsenic levels exist on the hillslope areas at the mine and in steam and floodplain sediments at locations were the hillslope drain has failed.
A preliminary site inspection was undertaken during November 2007, when elevated concentrations of arsenic were detected in the mill tailings material. This survey was followed up by a detailed investigation during January 2008 by the USGS technical team. The results of this latter investigation will be incorporated into a multi-faceted environmental study of arsenic contamination in the region.
The CERCLA remediation plan by BLM staff is awaiting CERCLA site study coordination with the USGS technical team.
No recommendations for remediation have been made to date, due to the early phase of site investigation.
Risks: Water quality, Arsenic contamination
Location: Section 8, T10N, R13W,SBBM, Kern County, CA
Field Office: Ridgecrest
Congressional District: 25