The Alberta government has laid 11 charges against CNRL in connection with a release of hydrogen sulphide from the company's Horizon Upgrader project near Fort McMurray on Aug. 2, 2012.

Each charge carries the possibility of a fine of up to $500,000. 

Environment and Sustainable Resource Development (ESRD) opened its investigation after receiving reports of high ambient air monitoring readings in the area and complaints from residents of the community of Fort MacKay, the province said in a news release Friday.

The charges under the Environmental Protection and Enhancement Act include:

  • release of a substance causing a significant adverse effect;
  • failure to ensure complete combustion at the flare stack, release of an unapproved substance, and failure to report approval contraventions;
  • providing misleading information to the Director and the Fort McKay First Nation; and,
  • failing to properly report the contravention and release to the Director and the Fort McKay First Nation.

Environment Minister Robin Campbell issued a written statement that doesn't mention CNRL or the charges, but said the government takes environmental protection seriously.

"Our ability to open new markets for our oil — or to maintain the markets we have today — depends on our credibility when it comes to responsible oilsands development," the statement said.

"Alberta is a leader when it comes to having stringent environmental monitoring, regulation and protection legislation. We are proud of this and remain committed to ensuring that we develop our resources in a responsible and sustainable way."

CNRL was also charged with releasing hydrogen sulphide gas at the same plant back in 2010. Those charges are back in court in June 2014.

The company is to appear in Fort McMurray provincial court on the latest charges on April 14.

Hydrogen sulphide gas is produced during the bitumen upgrading process. It is highly poisonous and flammable with the characteristic odour of rotten eggs.