Oil Sands Mine Reclamation Cover Study
Evaluating the effects of reclamation-cover depths on the performance of vegetation on reclaimed oil-sands mine sites.
Canada’s largest surface mining occurs in the oil sands mines in the boreal forest of northeastern Alberta. Cover systems for oil-sands mine reclamation consist of soils or other reclamation materials (e.g., clean overburden from the mining process) placed over mine wastes in order to support revegetation. To properly design cover systems and optimize volumes of reclamation materials it is necessary to understand the effects of reclamation-cover depths on reclaimed vegetation performance. To support this understanding, IEG was contracted by a major oil-sands mine operator to conduct an assessment of reclamation cover depths as part of an integrated and multidisciplinary research team including academic researchers and other environmental consultancies.
IEG’s role in this project was to investigate the effects of reclamation-cover depth on above-ground vegetation responses. This included field sampling, data interpretation and synthesis, and reporting. The project results indicated that the required cover depths were conservative (more than required) to support desired upland plant functions and responses, and likely non-conservative (higher-risk) for other landscape-level goals such as ensuring water delivery to receiving wetlands. Ultimately this work and its results will be used by the operator for future reclamation planning and monitoring, and was used in a successful regulatory application to reduce required reclamation cover depths over saline-sodic overburden.