The disposal cell is excavated in phases. About 25% of the cell remains to be excavated. Excavation depth is 25 feet below the ground surface.
Tailings are end-dumped from the containers, loaded into dump trucks, and driven to the disposal area where they spread for compaction using a dozer. A sheep’s foot roller compacts them in place in the cell. During the month of May 2023, 94,700 tons of mill tailings were disposed of in the cell.
The cover on the disposal cell consists of multiple layers of soil and rock as illustrated in the diagram below. Interim cover is placed on portions of the cell once the final grade for tailings material has been met. Final cover layers have been installed over portions of the interim cover.