The allegations stem from a submission filed with the CEC in 2010 by two non-governmental organizations – Environmental Defence Canada and the Natural resources Defense Council – and three individuals. The claim is that the government of Canada has not been properly enforcing the section of the Fisheries Act, which deals with pollution prevention and establishes a prohibition against depositing harmful substances into water bodies inhabited by fish.

The CEC move sends a signal that the concerns have merit and casts doubt on Canada's ability to manage the environmental impacts of the oilsands, said Gillian McEachern, with Environmental Defence.

"The federal government has been hard at work to convince the U.S. government that it's doing its job and this is another example that it's just simply not," she said in an interview. "This is yet one more serious example of why the U.S. shouldn't buy the line coming from Canada that things are under control when it comes to the environmental impacts of the industry."