Hudson Bay drainage basin
The Hudson Bay drainage basin is the drainage basin in northern North America where surface water empties into Hudson Bay and adjoining waters. Spanning an area of about , the basin is almost totally in Canada (spanning parts of the Prairies, central and northern Canada), with a small portion in the United States (in Montana, the Dakotas, and Minnesota). The watershed's headwaters are in part on the Continental Divide of the Americas, and the watershed's connection to the Labrador Sea is at the Hudson Strait's mouth between Resolution Island in the Qikiqtaaluk Region and Cape Chidley on the Labrador Peninsula. On the Continental Divide the basin is bounded at Triple Divide Peak to the south, and Snow Dome to the north.
Pollution in Canada
Pollution of the Great Lakes, the world’s biggest bodies of fresh water, continue to be a significant problem for both Canada and the United States. According to Derek Stack, executive director of Great Lakes United, "High pollution levels in the Great Lakes basin continue to take an apparent toll on the air and water quality of the ecosystem." 
In 2002, it was reported that the Great Lakes basin was home to 45% of all toxic air pollution in Canada, in turn affecting the Great Lakes' water. An even more recent report suggests that the Alberta oil sands' impact could reach as far as the Great Lakes. The report warns that "[oil] refineries will be using the Great Lakes ‘as a cheap supply’ source for their copious water needs and the area’s air ‘as a pollution dump'."