Imperial Oil Ltd. spilled crude from its Mihihkan plant at the Cold Lake oil-sands site, contaminating a flock of geese in the latest environmental mishap at the company’s facilities.   

An operational issue caused 900 liters (5.7 barrels) of crude to be released into a process-water lagoon on July 24, the Alberta Energy Regulator said on its website. Later, a flock of 12 geese became stained after landing in the lagoon. Wildlife deterrents such as cannons have been deployed around the site, containment booms have been added to prevent the oil from spreading and the site is under 24 hour surveillance. The birds were taken to a facility for cleaning and rehabilitation.

“There are no related operational impacts, and cleanup of the oil is underway,” Imperial spokeswoman Lisa Schmidt said in an email. “The oil remained contained in the lagoon, which is lined. There were no mortalities reported” among the birds.

The incident is the latest mishap at Imperial’s oil-sands sites. Two toxic releases at Imperial’s Kearl mine, one last year and the other earlier this year, prompted the federal government step up environmental oversight in the oil sands. The company and the Alberta Energy Regulator were accused of failing to adequately inform the public and local indigenous communities of the spills.