Cover Systems to Reduce Environmental Impact

Okane was engaged to develop a conceptual cover system design for two tailings basins, providing insight for operational and closure planning. The project’s overarching goal was to create a robust, cost-effective, and constructible cover system in alignment with site-specific objectives. At the time, the basins were causing watershed impacts due to seepage, which was characterized by relatively higher concentrations of constituents of interest (COIs). The site-specific challenge Okane was presented with was the reduction of COIs in the surrounding environment.

Okane developed models to inform effective cover system options, considering solutions that could be implemented during operations to mitigate potential risks or liabilities during closure. Additionally, Okane provided recommendations and proposed a risk-based approach to guide decisions before developing detailed cover design alternatives based on the permeability of the underlying foundation material. These recommendations focused on reducing COI concentrations that affected the watershed.

Okane’s conceptual cover system design effectively reduced seepage into the groundwater flow system by minimizing water percolation through the cover system. Once implemented, the cover system will result in lower concentrations of COIs into the surrounding watershed.