Under the Canadian Environmental Assessment Act, there are a number of triggers that cause the federal government to carry out an environmental assessment. It could be federal funding or it could be a river crossing or some loss of fish habitat that would trigger the review. So if the tailings pond is not in a fish-bearing water, is not crossing a river, then it wouldn't trigger the federal environmental assessment, and so the federal government wouldn't be directly involved. Of course, all of the scientific knowledge that we have at Environment Canada is publicly available and could be used by the provincial assessment, but we're not directly involved in a provincial environmental assessment.
On March 12th, 2009. See this statement in context.