Silver Basin Phase 3 pump station has been commissioned successfully. This project has been in construction for several years and is a big accomplishment. This high and low head pump station has a combined capacity of 40,000 GPM which will deliver 20,000 GPM PLS to Modoc, and another 20,000 GPM to Stargo and Central SX. Completion of this pump station allows for the tie in of the Phases 1 and 2 stockpile to Phase 3. Once all three of these phases are tied in together the stockpile will just be known as the Silver Basin Stockpile.
The project included blasting and excavation of 730,000 CY of rock from the pump station area, and the excavation of a solution tunnel through rock to connect the stockpile collection system with the PLS impoundment. The work that remains is the demolition of the Silver Basin phase 1/2 pump station which includes the existing PLS sump, valve vault, transform substation, pipelines, pumps motors, and concrete infrastructure. Installation of the main diversion channels from Phase 1/2 to the Phase 3 stockpile will commence once demolition is completed. The foundation/solution collection system for Phase 3 includes placement of a compacted crushed leach under-liner, and the installation of 6.1 MSF of LLDPE and HDPE liner 433,000 CY of over liner, 640,000 CY of select ROM, and 958,000 CY of general ROM.
This work is scheduled to be completed early in the fourth quarter 2023.