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.


Oil sands mine water release means water that has been used in oil sands operations has been treated and then allowed back into the surrounding environment. Through the safe release of water, oil sands mine operators can: reduce the need for additional footprint for water storage, reclaim tailings areas sooner, reduce timelines for reclamation, and meet closure and reclamation outcomes.

In most cases, the water will be released into the Athabasca River or its tributaries. Any water released will meet release criteria set to protect the environment and human health. Each mine site will need to meet specific criteria and requirements prior to releasing treated water. Monitoring, both site specific and regional, will ensure compliance with the regulations and check that the controls in place are working.

Currently, government is working to develop requirements to allow for the safe release of water used in oil sands mining operations.


Active tailings ponds are part of oil sands mine environmental management and monitoring programs aimed at reducing and understanding any potential environmental risks associated with their operation. Oil sands mining companies are committed to high environmental standards and conduct extensive monitoring for their operating sites. In addition, oil sands mining companies support and fund regional monitoring programs that ensure there is broader-scale monitoring in the oil sands region, including monitoring for potential cumulative effects.

The oil sands industry contributes up to $50M per year towards regional monitoring programs and an additional $130M per year towards project-specific monitoring programs. As a result, the Athabasca River watershed is one of the most monitored watersheds in the world!


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.

Did You Know?

Since 2012, COSIA members have invested $826 million in 228 contributed tailings technologies. In 2020, 57 active projects were underway through COSIA at a cost of $150 million. (Source: COSIA, 2020)


Canada’s Oil Sands Innovation Alliance (COSIA)s a group within Pathways Alliance, an alliance of oil sands producers focused on accelerating the pace of improvement in environmental performance in Canada’s oil sands through collaborative action and innovation. COSIA’s Tailings Environmental Priority Area (EPA) is focused on improving the management of oil sands tailings through identification of new or innovative technologies or processes for tailings management.

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