Midas Gold’s project is located in the remote central Idaho Rockies near the town of Yellow Pine. It is a brownfields gold-antimony project featuring three open pits and an anticipated 22,000 tpd plant throughput, along with challenging terrain and environmental constraints. Tierra Group was responsible for the completion of the preliminary feasibility design for the proposed tailings storage facility, water diversions, and site-wide water management, including relevant content for the NI-43-101-compliant prefeasibility technical report.
Tierra Group developed the prefeasibility design for the TSF, surface water diversions, and closure plan for the TSF and waste rock storage facility. The TSF will be lined with a composite geosynthetic liner system and also includes a rockfill embankment approximately 460 feet tall that will be built in multiple stages during project development. Diversions include a channel diverting a perennial mountain stream around the TSF, and a combined channel / tunnel diverting a river around one of the open pits. The tunnel diversion was designed to facilitate passage of migrating salmon, opening access to spawning habitat that had been blocked for decades due to previous mining in the district.
Tierra Group continues supporting Midas by completing baseline geotechnical assessments and geotechnical investigations, as well as assisting Midas Gold with the upcoming Feasibility Study.