Essentially, in the framework that Environment Canada had developed as part of the Great Lakes Water Quality Agreement, it focused on the Great Lakes, so, for example, there was the lakewide management plan for Lake Erie. There was a similar effort undertaken for lower Lake Huron. And Lake St. Clair, being part of the connecting channel, is neither one or the other of the Great Lakes. It was recognized that Lake St. Clair was a special case, and that the impacts of the watersheds that were draining directly into Lake St. Clair were proportionally greater because of the very small volume within Lake St. Clair.
On March 25th, 2014. See this statement in context.