Alberta to Consider Injecting Oil Sands Wastewater Deep Underground

An oil sands tailings pond in Fort McMurray, Alta., in a file photo. The Canadian Press/Jason Franson

The government of Alberta has accepted recommendations to consider injecting oil sands wastewater underground as a means to address volumes of toxic tailings accumulating on oil sands mining sites.

The suggestion is one of the first five recommendations set out by the Oil Sands Mine Water Steering Committee, which was established by the province of Alberta in 2024 to assess options for managing the water stored in oil sands tailings ponds, which is the waste product that results from extracting bitumen from oil sands ore.

In its June 12 recommendations report, the committee says that injecting mine water underground through deep well disposal provides a “practical solution” to managing excess untreatable tailings water by isolating the water from the environment and thereby “preventing potential harm” to surface water and groundwater resources.

“Deep well disposal involves the injection of oil sands mine water (OSMW) into underground geological formations,” the report says. “The injected [mine water] is disposed of beneath multiple layers of impermeable rock, ensuring that it does not contaminate drinking water sources.”

However, the committee says that deep well disposal should not be used as a primary or long-term solution and should be considered as “one tool in a comprehensive suite of management strategies” for mine water, such as reusing, sharing across operations, and treating and releasing to the environment when possible.

“This approach helps to mitigate the continued accumulation of OSMW and provides a buffer while longer-term water management strategies are being developed and implemented,” the report says, noting that regulations should be put in place to limit the volume of wastewater that can be injected.

The province says there are more than 1.4 billion cubic metres of wastewater in tailings ponds, but the recommendations do not specify how much of this volume should be disposed of.

‘Careful Considerations’

The report says that deep well disposal of mine water will “permanently remove potentially treatable water” from the water cycle, which in turn would reduce the amount of water that could be reused for oil sand operations or released back into the watershed.

The committee noted that this approach to managing wastewater is inconsistent with the province’s water conservation policies, such as Alberta’s Water for Life strategy and Water Conservation Policy for Upstream Oil and Gas Operations.

“At a minimum, untreated OSMW should be treated to a level where the useable water can be recycled or reused safely for other operations and/or other beneficial water uses,” the report says.

The committee also noted that deep water disposal would require access to large “pore-space volumes” across multiple disposal sites and would necessitate further assessments, monitoring, authorizations, and risk mitigation strategies. In addition, access to pore space may be limited due to competition including carbon capture and storage, other disposals, and geothermal.

“The challenge of oil sands mine water and tailings ponds is undeniably complex, and simple fixes don’t exist,” said Tany Yao, chair of the Oil Sands Mine Water Steering Committee, in a June 12 letter introducing the recommendations.

“We recognize the strong and varied opinions surrounding this issue. Navigating the technical complexities of oil sands mine water and tailings requires careful consideration of many viewpoints.”

Alberta’s Environment Minister Rebecca Schulz thanked the committee for its effort to explore options to improve mine water management in the province in a June 12 news release.

“We need to start finding a path to more effectively manage oil sands mine water and tailing ponds,” Schulz said in a statement. “Doing nothing while mine water continues accumulating is not a sustainable approach.”

The provincial government says that Alberta Environment and Protected Areas will work with the Alberta Energy Regulator to evaluate the committee’s recommendations over the next six months.

NDP environment critic Sarah Elmeligi has criticized the approach, saying it is “irresponsible because we don’t know the risks involved to groundwater or geological stability.”

“I don’t know that we are at a stage where we could even say if we can safely inject anything down there,” she said in a media statement.

The Canadian Press contributed to this report.