CUP 98-0022 Mesquite Mine Expansion

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement EPIMS-IMP-31209-R6 for the Mesquite Leach Pad Optimization Project in eastern Imperial County, California. This regulatory agreement, issued pursuant to Section 1602 of the Fish and Game Code, authorizes the construction of Leach Pad 8 at the Western Mesquite Mine. The project covers 87.28 acres and involves integrating new infrastructure into the existing mine site, specifically focusing on impacts to streams associated with the expansion. Technical specifications for the project require the leach pad to be constructed on at least 12 inches of low-permeability or compacted soil, overlain by an 80-mil linear low-density polyethylene liner and a protective layer of crushed rock or gravel. A critical component of the design is the installation of a leak detection system beneath the primary solution collection pipes. To ensure environmental protection, all activities must occur within an existing fenced area designed to exclude desert tortoises. The CDFW has determined that the project will not have a significant environmental effect within its jurisdiction, provided that the adopted mitigation measures and monitoring plans are followed.