Oil Sands Tailings

In oil sands mining operations, tailings are a mixture of water, sand, clay and residual bitumen, and are the by-product of the extraction process used to separate the oil from sand and clay. Tailings and tailings ponds are not unique to the oil sands – they are used around the world in mining and other industrial processes.

Tailings ponds are engineered dam and dyke facilities used for safe storage of tailings materials. Tailing ponds are also used to enable water to separate from the tailings. Water from the tailings ponds is recycled back into the extraction process, reducing the use of fresh water from the Athabasca River and other sources. Oil sands mining operators recycle an estimated 75% of water used. 

The Government of Alberta, through the Tailings Management Framework (TMF) for the Mineable Athabasca Oil Sands, provides direction for all oil sands operators to manage fluid tailings volumes, during and after mine operations, in order to manage and decrease liability and environmental risk resulting from the accumulation of fluid tailings on the landscape. Recognizing that the mineable oil sands are a significant resource, and that tailings are a by-product of mining activity, the TMF provides a framework to manage existing and future tailings production.

The objective of the TMF, and associated regulatory requirements, is to minimize the amount of fluid tailings on the landscape and ensure operators reclaim tailings progressively over the life of the mine. Project-specific targets are set for each operation to ensure tailings are ready to reclaim within 10 years of the end of the mine’s life. To enable this goal, it is also recognized that treated water will need to be released from oil sands mining operations to enable overall reclamation of the mine sites.

Reclamation of the oil sand mining industry’s first tailings pond, Suncor’s Pond One (Wapisiw Lookout), was completed in 2010. Strict regulations and a comprehensive monitoring program are in place to ensure that reclamation and end land use outcomes are met. All oil sands mining operators plan mine development to enable reclamation of the site once mining operations are completed. In addition, industry actively seeks input from Indigenous communities, government agencies and other local stakeholders to inform planning for reclamation of the disturbed mining landscape.

In addition to requiring operators to include reclamation and closure plans for all tailings ponds in broader site closure planning, the government requires financial guarantees for each mining project to ensure reclamation plans are carried out. Oil sands mining operators contribute to the Mine Financial Security Program, a fund held by the government for reclamation of land impacted by mines. These funds are used only if operators do not carry out their reclamation plans. To date, there has never been a need to draw on this fund, so it continues to grow.