Canadian Natural Resources Ltd. has been fined $500,000 for toxic chemical releases at its Horizon oil sands mine.
Alberta Environment and Parks announced the penalty late on Friday.
The company was fined $350,000 for failing to immediately report a 2010 release of hydrogen sulphide after its sulphur recovery unit failed at the operation. It was penalized another $150,000 for a separate release in 2012.
The province said $425,000 of the total penalty will go to researchers at the University of Calgary to study the toxicological effects of chemicals measured in the air in and around the aboriginal community of Fort MacKay.
Canadian Natural's expanding Horizon mine is slated to ultimately pump 250,000 barrels per day.