After decades of research, testing and technology development, the oil sands mining industry is seeking to release treated mine water into the Athabasca River. However, there are still many steps involved before any water can be released.
Proven water treatment technologies and ongoing research show that oil sands mine water can be treated to enable safe release. The industry is now working with provincial and federal governments to develop standards and regulations for mine water release.
Why release mine water?
Water release is an essential tool for meeting the industry’s goal of responsible environmental stewardship, reclamation and eventual closure of oil sands mines.
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Like many industrial processes, the oil sands mining process requires water. Other industries and types of mines in Canada are allowed to release treated water to a natural aquatic environment – provided the water meets stringent regulatory requirements – but no such regulations exist for releasing treated water from oil sands mining operations. Instead, oil sands mines have been required to store water on site, for decades in some cases, in large, engineered ponds known as tailings ponds. As a result, a very large volume of stored water has accumulated.
Permanent storage of water is not a best practice and prevents the full restoration and reclamation of land used for oil sands mining, so the industry is now working with regulators to develop standards that would allow treated water to be released.
In these ponds, the solid components of tailings gradually settle, leaving a layer of water at the top. It’s this water that would be extensively treated prior to release back into the local environment, which is where the water came from in the first place.
Knowing that storing water in tailings ponds cannot be a permanent solution, oil sands companies have conducted extensive research into how to treat this stored water to make it safe for release. This research, testing and development of treatment technologies has reached a point where oil sands operators are now confident that treated water could safely be released into the environment.
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Proven treatment technologies
Water at oil sands mines needs to be treated to ensure concentrations of constituents in the water are at levels safe for release to the environment. These constituents include suspended solid material (sand, silt, and clay) and a range of metals that are also commonly found in other industrial waters. Some other constituents are unique to oil sands mine water, such as organic compounds.
Oil sands operators have the demonstrated processes, including innovative technologies developed via Canada’s Oil Sands Innovation Alliance to treat these constituents to levels that are safe for release. The industry continues to invest in applying, adapting and improving the effectiveness of these treatment processes as well as new technologies. After decades of work in this area trying different methods with constant improvement as the goal, industry is confident that water can be treated and safely released to the environment once regulations are established.
With regulations in place, water will be treated using proven technologies and released from individual sites over a period of many years. Ongoing water quality testing and environmental monitoring will provide assurance that water release is not impacting the environment.
Safe for the environment
Release of treated water from oil sands mines will be regulated by both the federal and Alberta governments, ensuring protection of the environment and human health. Once regulatory requirements are established, companies will select the best treatment tools for each mine site. With effective regulations in place, more detailed planning for the treatment of mine water and reclamation of oil sands mines can progress.
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The volume of treated water that will be released into the Athabasca River watershed at any one time will be very small compared to the flow of the river. Total water volumes currently stored equal about two per cent of the annual flow of the Athabasca River.
The safe release of treated water into the Athabasca River will:
- Reduce water storage requirements
- Minimize further land disturbances associated with water storage
- Enable progressive reclamation and final reclamation outcomes at closure.
Beyond focusing on the science and technology needed to safely release treated water, the industry is also working with Indigenous partners and local communities to understand their concerns, ensure awareness of the research and regulatory work now underway, and engage on matters important to all.
