Calgary-based Imperial Oil is facing continuing blowback for two releases of tailings from its Kearl oil sands mine in northern Alberta, days after Environment Canada opened an investigation into the spills.

Environment and Climate Minister Steven Guilbeault said the move came after weeks of sampling and testing of water near the site, where tailings ponds seeped into groundwater and where 5.3 million litres of wastewater overflowed from a containment pond, The Canadian Press reported last week.

“The decision to move from an inspection to launch a full investigation means that the file has reached a stage where officers will determine if charges are warranted,” Guilbeault said.

“It means the process is under way to hold the company to account.”

Imperial said it will cooperate with investigators.

“We have been providing information on the situation at Kearl and have hosted regulatory officials for tours and testing at our site,” spokesperson Lisa Schmidt told CP in an email.

In the days immediately before and after Guilbeault’s announcement, an Indigenous leader called for charges against Imperial, a subsidiary of Houston-based ExxonMobil, and a Canadian pension fund not widely known for its pro-active stance on the energy transition took the company to task for its performance at Kearl.

On Monday, Dene Nation National Chief Gerald Antoine said he was “extremely disappointed” that Canada and Alberta had not halted operations at the Kearl mine and called for the company to be charged, Yellowknife-based Cabin Radio reports.

“It is disappointing that not only are our treaty lands, waters, birds, animals and families being poisoned by tar sand developments in Alberta, but we practically have to beg to be engaged by industry and the governments of Alberta and Canada,” Antoine said in a release.

And last week one of Canada’s biggest pension fund managers, the British Columbia Investment Management Corporation (BCI), voted against re-election of two Imperial Oil directors—including board chair and CEO Brad Corson—to express its “displeasure” with the leaks, the Globe and Mail writes.

BCI said it wanted to hold Corson accountable “for what we believe to be a lack of risk oversight that led to major controversies related to tailings integrity and engagement with Indigenous communities.” The fund also voted against the chair of the Imperial board’s community collaboration and engagement committee, Miranda Hubbs, after taking issue with “a lack of oversight that led to major controversies related to insufficient engagement with Indigenous communities.”

Hubbs also serves on the board and two board committees of PSP Investments, the federal public service pension plan.

In May 2022, Imperial workers discovered what they at first called discoloured water seeping from one of the mine’s tailings ponds, CP recalls. The substance was later found to be groundwater mixed with mine tailings.

Another release in February sent 5.3 million litres of contaminated surface water overflowing from a containment pond.

Environment Canada has confirmed the presence of hydrocarbons and naphthenic acids in a small fish-bearing lake located almost entirely within Imperial’s lease. Federal inspectors have already said they believe the tailings-contaminated groundwater and surface water to be hazardous to wildlife.

The Globe says “dangerous levels of arsenic, dissolved metals, and hydrocarbons” have been seeping into a fish-bearing lake, as well as tributaries of the Firebag and Muskeg rivers.

At the time the first release was discovered, both Imperial and the Alberta Energy Regulator (AER) failed to keep area First Nations and responsible governments updated, even after it realized the seepage contained tailings, CP writes. That failure provoked widespread outrage that resulted in three separate investigations—one by Alberta’s information commissioner, one by the House of Commons environment committee, and a third-party consultant review commissioned by the regulator’s board.

It also led Guilbeault to propose a notification and monitoring working group. That group, currently being formed, could include industry, Alberta, Ottawa, the Northwest Territories, and area First Nations. The details are now being discussed, but will likely have to wait to be firmed up until after the Alberta election May 29.

However, a spokesperson in Guilbeault’s office said the group would likely have two roles: ensuring all affected parties are notified early and often in the case of another leak and monitoring the effects and cleanup of such an event.

It will be separate from Alberta’s Oilsands Monitoring Program, which is intended to track long-term changes in the local environment.

First Nations have asked for that body to undertake a risk assessment of all tailings ponds in the oil sands region, which hold more than 1.4 trillion litres of toxic wastewater.

“We need to study the risk from the tailings ponds and the risk to human health so that we can better understand the gravity of the problem,” Guilbeault said.

Greg McLean, a Calgary Conservative MP and member of the House environment committee, called the communication lag “a failure that has to be fixed.”

McLean told reporters the issue raises questions about the Alberta Energy Regulator.

“There are clearly things wrong with this regulatory body and this points it out in spades,” he said. “In the real world, there’s accountability for things that don’t go right.”

Edmonton New Democrat Heather McPherson, also a member of the environment committee, welcomed the investigation.

“After weeks of pushing by the NDP, an investigation is a step in the right direction to hold Imperial Oil accountable,” she said in a release.

The environment minister for the Northwest Territories, downstream from the oil sands, is on board with the proposed working group.

“We look forward to action to meet these commitments because transboundary water management agreements only work if all parties commit to information-sharing,” Shane Thompson said in a release.

Imperial’s Schmidt said the company has installed a vacuum system to collect shallow groundwater by the pond, which continues to seep. It has also installed a series of pumps and trenches to track the plume and prevent it from spreading.

“Water testing has indicated drinking water is safe,” wrote Schmidt. “There continues to be no indication of impacts to wildlife or fish populations.”

But on Friday, according to an AER notice obtained by Cabin Radio, Imperial said it found “up to 10 deceased wood frogs” near a water body north of the Kearl lease.

The main body of this report was first published by The Canadian Press on May 4, 2023.