Sustainability at Suncor

Tailings management

Our tailings reclamation is a story of ongoing collaboration, learning and innovation.

Fluid tailings are the focus of our tailings technology improvements. Although sand separates quickly from the tailings, smaller particles of clay and silt remain in suspension and form fluid tailings, which in the past could take decades to separate. Finding ways to treat fluid tailings quickly and cost-effectively is critical to improving our overall reclamation performance.

An industry leader in tailings management, we manage tailings stability risk through our Tailings Facility Management System and Operational Excellence Management System which guide our corporate accountability for tailings, effective operations integrity and governance, and robust dam safety management.

Over the past several years, our holistic Tailings Reduction Operations (TRO™) tailings management approach and the implementation of permanent aquatic storage structure (PASS) treatment process have allowed us to reduce our total fluid tailings inventory at Base Plant. In 2019, PASS treated more than 25 million cubic metres of fluid tailings, a new annual treatment record. This represents 2.3 times the 2019 volume of fluid tailings produced.

Permanent aquatic storage structure (PASS) is a Suncor-led research and technology development project focused on an accelerated dewatering process and treatment of fluid fine tailings creating a PASS lake shortly after the end of mine life.

Regulatory requirements

We have enhanced our management plans and tailings management approach to meet the requirements of the Tailings Management Framework (TMF), developed by Alberta Environment and Parks under the Lower Athabasca Regional Plan and implemented in 2015. Suncor worked with Indigenous communities, the Alberta Energy Regulator (AER) and other stakeholders to support the development of the Fluid Tailings Management for Oil Sands Mining Projects (Directive 085). Finalized in 2017, this regulation includes tailings management plan application and tailings performance reporting requirements aligned with the TMF.

Dam safety and integrity

We take tailings dam safety very seriously and have been implementing a robust dam safety program since we began operations in the Athabasca Oil Sands in the late 1960s. Our dam safety program protects the integrity of tailings dam structures through extensive checks and balances for design, construction and monitoring, including a series of internal and external reviews, and adherence to industry-leading tailings and dam safety guidelines and government regulations.

Additional information is available in Suncor’s response to the Investor Mining and Tailings Safety Initiative. Suncor has disclosed an extensive data table on our tailings facilities including location, dimensions, and status. An interpretation document has also been provided for additional context.


Suncor is committed to the responsible development of oil sands resources, addressing tailings treatment, and engaging Indigenous communities and stakeholders. On November 19, 2019, we hosted the Suncor Sharing Session on Tailings to share information on tailings results and plans, and to provide an opportunity for Suncor staff to gather feedback and input from Indigenous community members.

Fluid tailings management

As our mining operations have expanded, the volume of fluid tailings have increased. However, with the implementation of TRO™ in 2010, fluid tailings volumes at site remained steady and have now begun to reduce with the implementation of our PASS technology.

From 2015 to 2019, Base Plant alone has treated over 100 million cubic metres of fluid tailings. Fluid tailings inventories peaked in 2010 and with this amount of treatment, the total inventories are now reducing so that Base Plant is ahead of regulatory requirements. Since 2018, fluid tailings treatment capacity has increased by commercially implementing our PASS fluid tailings treatment process. This has allowed for a 5% reduction in untreated fluid tailings inventory as of the end of 2019 at Base Plant operations. Base Plant currently has about 263 million cubic metres of fluid tailings.

 Up close view oil sands tailings management technology
Up close view of oil sands tailings management technology.

Suncor is working to reduce the number of active tailings ponds. Even with the start of a new mining operation (Fort Hills), the total number of active tailings has reduced over the last 10 years, with one being surface reclaimed and three more advancing to closure.

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