The Alberta Energy Regulator (AER) has approved Suncor Energy’s plans for managing its oilsands tailings as the company’s base mining operations approach their end of life, which is 2033.
The AER had denied the applications in March, saying essentially that not enough information had been provided about an “unproven technology.”
Suncor had proposed using water capping or end-pit lake technology to contain about 70 percent of its tailings volumes, which are made up of sand, silt, clay and residual bitumen left behind after bitumen extraction.
Over the past few months, Suncor says its technical experts have met with Aboriginal communities, stakeholders and the regulator to clarify and provide additional information about its tailings management plan. The approved plan will facilitate the treatment of current fluid tailings, reduce the tailings inventory and decrease the overall number of tailings ponds on site, the company says.
A demonstration end-pit lake has been operating at Syncrude since 2012, but Suncor spokeswoman Sneh Seetal explains that the processes are different in that while Syncrude has placed water overtop of untreated tailings, Suncor plans to treat its volumes prior to end-pit lake creation.
“We have developed a technology that works for our mine plan and the geology we have,” Seetal said. “Using mining best practices is why we’ve proceeded down that path,” including work Suncor has conducted as part of Canada's Oil Sands Innovation Alliance.
There are approximately 180 end-pit lakes around the world, with 50 in Canada alone, she said.
“There are lots of successful end-pit lake examples, and our goal is to be the same.”
This week’s AER approval comes with a big caveat related to water capping.
The regulator describes Suncor’s plan as “a newly patented, unproven technology that uses the addition of chemicals to dewater the tailings and reduce the mobility of contaminants.”
Water will be placed on top of treated tailings after the end of mine life (2043–2053), creating an aquatic closure, the regulator said in its approval.
“The proposed technology…has uncertainties; Suncor acknowledges the addition of chemicals to reduce the mobility of contaminants released to the water cap has only been demonstrated at a lab scale to date,” the AER said, adding that Suncor’s demonstration pit lake pilot test is planned to run over the next 15 years in parallel to commercial scale implementation of the technology at its site.
The AER said it shares concerns that have been raised about the proposed technology. In addition, the Government of Alberta has yet to unveil its expected policy on water capping tailings and end pit lakes.
“Suncor is prohibited from placing water over treated or untreated tailings until Government of Alberta policy is received, and is required to meet future policy on water-capped tailings and pit lakes. Suncor must also conduct and report on research and monitoring to resolve uncertainties with the proposed tailings treatment and water capping,” the AER said.
“Suncor must propose the final closure outcome…by 2023, which will include the results of terrestrial and aquatic research and implementation design and planning. This is ten years before end of mine life. This is a critical deadline as it should provide enough time for Suncor to adjust their tailings management plan to meet any applicable policy if water-capped tailings and pit lakes are restricted by any applicable policy in effect at that time.”
The AER has added research, monitoring, evaluation and reporting requirements to Suncor’s approvals to “provide the information needed to verify the technology and deposit performance assumptions in order to ensure that Suncor’s performance is tracking to the objective and outcomes of the [regulations].”
The AER added that this approval approach is designed to get appropriate and timely information so as to inform the approaching end of mine life regulatory decisions and manage risk.
“It is not sufficient to rely exclusively on outcomes-based approvals,” it said.
Suncor said it will now work to implement its tailings management plan, “working diligently to address the conditions outlined in the approval and continuing to engage with Aboriginal communities and stakeholders.”