An Alberta oil and gas company has been fined $15,000 for failing to report a potentially lethal amount of hydrogen sulphide, or sour gas, had been released into the atmosphere.

The Alberta Energy Regulator says a tank at a Mcland Resources work site near Tees, Alta., a hamlet about 55 kilometres northeast of Red Deer, ruptured in 2023.

The toxic gas was released for more than three hours.

The regulator says the company was aware of the rupture and worked to stop the release but failed to report i…