Castle Mountain Mine Phase II Expansion Project

Castle Mountain Venture (CMV) has submitted a proposal for the second expansion of the CMM. The Project is referred to as the “Phase II Expansion.” The Phase II Expansion would extend the mine life by approximately 30 years, with 20 years of mining and processing and 10 years of reclamation. Operations would effectively quadruple the annual mining rate from 18 million tons to 80 million tons. The increased rate would require a total of 2,250 acre-feet per year of groundwater and up to 25 megawatts of power. To meet these demands, CMV would construct a 32-mile water pipeline and a 16.5-mile powerline (Figure 1) from Walking Box Ranch to the second phase of development. Walking Box Ranch is listed on the National Register of Historic Places, owned by the BLM, and managed by the BLM and the University of Nevada, Las Vegas Public Lands Institute. The proposed utilities would be located largely within existing rights-of-way and would cross public land managed by the BLM CA NFO and the BLM NV Las Vegas Field Office (Figure 2). The proposed Project would include the expansion of the mine pits, overburden sites, and heap leach pad, all within the existing Approved Project Area (APA). The APA, shown in Figure 2, was previously approved by the BLM and the County. The Project would also include the installation of the associated pipeline and powerline, which would disturb an additional 1,800 acres of BLM land outside of the APA, for a total project disturbance of 3,294 acres. CMM’s access road was approved under the mine’s original BLM Plan of Operations (CACA-031137) in 1990. When the California Desert Protection Act of 1994 established the Mojave National Preserve, it inadvertently included 1,000 feet of the mine’s access road and proposed utilities. CMV has proposed a realignment of the mine’s access road that avoids the Preserve but would disturb 5 acres of BLM land. The National Park Service will participate in the NEPA/CEQA process and will assist BLM in selecting the preferred road alignment. The proposed expansion includes: - Extending the mine life by approximately 30 years, with 20 years of mining and processing and 10 years of reclamation. - Quadrupling the annual mining rate from 18 million tons to 80 million tons. - Increasing the total land disturbance by an additional 1,800 acres. - Increasing mining by an additional 296 million tons. - Increasing overburden stockpiling by an additional 196 million tons. - Increasing crushing rate from 6 million to 19 million tons per year. - Increasing power usage to 25 megawatts of power per year. - Increasing groundwater use by an additional 1,625-acre feet per year: - 830 to 1,340 acre-feet per year would be supplied from wells at the mine site within Lanfair Valley Groundwater Basin - 830 to 1,340-acre feet per year would be supplied via a pipeline from wells within the adjacent Ivanpah Valley Groundwater Basin - ~8% reduction in flow at Piute Springs (riparian habitat and ecological reserve). - Expanding and deepening open pits to more than 400 ft. below the water table. - Employing up to 500 temporary and 400 permanent workers. - Creating an open pit lake, which will remain as a permanent land feature.