Clause 9(2) of Bill C-469 says:
(2) The Government of Canada has an obligation, within its jurisdiction, to protect the right of every resident of Canada to a healthy and ecologically balanced environment.
Clause 8, which refers to the scope of application, says:
8. The provisions of this Act apply to all decisions emanating from a federal source or related to federal land or a federal work or undertaking.
For environmental assessment processes, for example, there are already administrative agreements between Quebec and Ottawa. In the case of the Hydro-Québec dam on the Romaine River, there was a federal jurisdiction issue relating to the mouth of the river, and specifically to navigation. Generally, it was under the jurisdiction of Quebec, but a commissioner was appointed by Quebec.
In my opinion, it would be difficult to define it more specifically. The environment was never in issue in the British North America Act. However, it is also defined by agreements with the provinces. I do not anticipate there will be a lot of problem situations. Certainly if the federal government takes on a share of responsibility under a particular statute, a member of the public will be able to bring a legal action. I would remind you that it must relate to "decisions emanating from a federal source or related to federal land or a federal work or undertaking".
A federal source may be a regulatory body. Where it gets a bit complicated, though, is when we're dealing with regulatory bodies that wear two hats. There could be problems in cases where the role of a federal commissioner was challenged in a situation with a federal-provincial panel. For those cases, however, I would trust in the wisdom of the courts.