Castle Mountain Mine Phase II Expansion Project

The proposed Project involves the second major expansion of Castle Mountain Mine (CMM), including installation of an underground waterline and overhead powerline within existing rights-of-way (ROWs) to support the expanded operations. CMM is an existing open-pit gold mine and heap-leach operation located on a combination of private land, owned by Castle Mountain Venture (CMV; Project Applicant), and public land, administered by the U.S. Bureau of Land Management (BLM) Needles Field Office (NFO) in California and regulated in coordination with the County of San Bernardino (County). The proposed Project would extend the mine life by approximately 30 years, with 20 years of mining and ore processing followed by 10 years of reclamation and closure activities. The proposed Project would increase the annual mining rate from 22 million tons to 80 million tons. The increased production rate would require up to 2,250 acre-feet per year of groundwater and up to 25 megawatts (MW) of electrical power. To meet these demands, the Project Applicant proposes to construct a 31.5-mile underground water pipeline and a 16.5-mile overhead electrical transmission line. The proposed utilities would be constructed within existing ROWs and would traverse public land managed by the BLM NFO in California and the BLM Las Vegas Field Office (LVFO) in Nevada. The proposed Project would disturb a total of approximately 3,288 acres, including 1,474 acres of existing disturbance from previously approved development, 1,434 acres of proposed disturbance for the mine expansion, and 380 acres of disturbance associated with the proposed underground water pipeline and 16.5-mile-long, 69-kilovolt (kV) overhead powerline ROWs. The CMM Access Road was approved under the mine’s original BLM Plan of Operations (CACA031137) in 1990, as documented in the Record of Decision for the Castle Mountain Mine Project Environmental Impact Statement (EIS No. 890053; State Clearinghouse No. 88062708) (1990 Plan) (BLM?1990a). When the California Desert Protection Act of 1994 established the Mojave National Preserve, approximately 1,000 feet of the mine’s approved access road alignment and proposed utility corridor were included within the Mojave National Preserve boundary. CMV has proposed an alternative alignment that avoids the Mojave National Preserve but would disturb approximately five acres of BLM-managed land. The proposed Project includes: • Construction and operation of a 31.5-mile underground water pipeline within a proposed BLM ROW. • Construction and operation of a 16.5-mile-long, 69-kV overhead powerline within a proposed BLM ROW. • Increasing the total land disturbance by an additional 1,814 acres. • Increasing mining by an additional 296 million tons. • Increasing overburden stockpiling by an additional 196 million tons. • Increasing crushing rate from six million to 19 million tons per year. • Increasing the maximum rate of mining by an additional 62 million tons per year. • Increasing groundwater use from 625 to 2,250 acre-feet per year, an additional 1,625 acre-feet per year. • Expanding and deepening open pits to greater than 400 feet below the water table. • Providing up to 500 temporary and 400 permanent jobs. • Creating an open pit lake that would remain a permanent land feature. • Extending the mine life to 2060.