Grant: Alliance Grants

Metals and associated compounds contaminate more than 7,000 sites across Canada. Remediation projects currently underway at Faro Mine (Faro, YT) and Giant Mine (Yellowknife, NT) are considered among the most challenging. Since 2017, Crown-Indigenous Relations and Northern Affairs Canada has collaborated extensively with the Strategic Partnership Grants for Networks "Towards Environmentally Responsible Resource Extraction Network" (TERRE-NET) in studies at Faro and Giant and is the partner organization for this proposal. TERRE-NET research has significantly advanced understanding of the geochemical conditions at these sites and has reached a critical stage where this knowledge can provide quantitative forecasts of future environmental impacts to inform the efficacy of rehabilitation programs. The goal of the project is further development of comprehensive conceptual and numerical models of geochemical evolution at Faro and Giant for the assessment of future geochemical conditions under existing and remediated scenarios. At both Faro and Giant, covers are proposed to mitigate the release of metal-impacted drainage to the surrounding ecosystems. Various cover designs have proven to be an effective solution; however, materials and installation techniques are site-specific and comprehensive investigation is critical to the success of a cover, and the effectiveness of a cover system on the geochemical behaviour of the waste materials is uncertain. The complex interactions between physical and biogeochemical processes within mine wastes make a priori prediction of the extent of environmental impacts associated with an individual mine site challenging. Enhancements to previous research are: application of advanced mineralogical and emerging non-traditional isotopic characterization, comprehensive gas flux measurement; and development of numerical models to integrate collected data for the assessment of remediation scenarios. This project will provide a rigorous framework that can be applied to evaluate the potential benefits of new strategies for managing mine wastes at other mine sites in Canada and globally.