Imperial Oil Ltd., Exxon Mobil Corp.’s Canadian unit, is at risk of being charged for toxic leaks at its Kearl oil-sands mine in Alberta after the country’s environment ministry opened an official investigation into the spills.

“The decision to move from an inspection to launch a full investigation means that the file has reached a stage where officers will determine whether charges are warranted for non-compliance with federal Fisheries Act,” Steven Guilbeault, minister of Environment and Climate Change, said at a press conference. “The process is underway to hold the company to account.”

Since May 2022, water has seeped from a tailings area and from a wastewater pond at the Imperial Kearl oil-sands mine on two separate occasions. Local indigenous communities complained that the company and the Alberta Energy Regulator failed to inform them quickly and adequately enough about the leaks and the dangers they could pose to local water supplies and wildlife. The Alberta Energy Regulator didn’t tell the public about the spills until February.

The investigation comes as oil-sands producers face increased pressure from investors to reduce their environmental footprint, including their carbon emissions.   

“Imperial understands that Environment and Climate Change Canada is seeking additional information, and we are cooperating with the department,” Lisa Schmidt, an Imperial spokeswoman, said by email. “We have been providing information on the situation at Kearl and have hosted regulatory officials for tours and testing at our site.