Constructible Cover Systems at the Faro Mine Remediation Project

Located on the traditional territory of the Kaska Nation and upstream of the traditional territory of the Selkirk First Nation, the Faro Mine was once the world’s largest open pit mine for lead and zinc (Faro Mine Remediation Project, 2022). Today, the site stands as one of Canada’s most complex mine remediation projects. Decades of mining left behind 57 million tonnes of tailings and 260 million tonnes of mine rock, posing a risk of widespread acid and metalliferous drainage to land and water. The Faro Mine Remediation Project aims to reclaim the abandoned site by reducing acid and metalliferous drainage, minimizing the potential risk of contact water, and promoting long-term landform stability.

Okane was engaged to provide engineering designs and field oversight to support the construction of cover system field trials for the Landform, Cover, and Revegetation Pilot of the site’s remediation project. Collaborating with other subject matter experts, Okane evaluated existing construction methods for the cover system trials and optimized the trial design for practical implementation by considering locally available and suitable material sources, optimal cover thicknesses, and alignment with the site’s closure objectives. In support of closure design, Okane also provided construction quality assurance support, and installed meteorological and soil monitoring instrumentation to evaluate cover system performance.

Performance monitoring of the cover system trials showed that soil erosion decreased after the initial year of cover placement, and net percolation remained lower than predicted by the cover system conceptual model. Okane’s approach optimized the cover system design to facilitate constructability, align with project objectives, and inform decision-making to address long-term risks.