Grant: Collaborative Research and Development Grants

The oil sands industry presently produces 400 million barrels of oil annually and is expected to increase to 1,825 million barrels by 2030. Each barrel of oil produced is accompanied by 1.25 m3 of tailings. This corresponds to an increase in tailings production from 500 to 2,280 million m3 annually from now to 2030. Current tailings management plans include the construction of out-of-pit tailings ponds for the storage and disposal of tailings and associated process-affected (PA) water. A challenge faced in the design of these out-of-pit tailings ponds is the presence of regionally occurring buried sand channels that may act as preferential flow paths of PA water seepage. Preliminary modeling predicts the infiltration of PA seepage into the adjacent sand channels, however the extent of this impact is poorly understood. Research is proposed to: 1) Improve the understanding of PA water transport through the local, natural sediments to better quantify the extent of impact, and 2) Remediate impacted soils, including the development of risk-based closure mechanisms. Specifically, this research will evaluate the potential of natural attenuation within the overlying till and the sand channel. Further, this research will evaluate the potential to reduce the impacts of PA tailings water on the sand channel by both intrinsic biodegradation and in-situ oxidation. The proposed research will provide the ability to predict the fate and transport of chemicals of concern through clay-till, into and through a sand channel, promoting sound groundwater management and remediation as required in the oil sand mining industry.