Great Lakes Basin Great Lakes Basin The Great Lakes Basin consists of the Great Lakes and the surrounding lands of the states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin in the United States, and the province of Ontario in Canada, whose direct surface runoff and watersheds form a large drainage basin that feeds into the lakes. It is generally considered to also include a small area around and beyond Wolfe Island, Ontario, at the east end of Lake Ontario, which does not drain into the Great lakes, but into the Saint Lawrence River. The basin is home to 33
Great Lakes "Since the early 1970s, the level of treatment to reduce pollution from waste water discharges to the Great Lakes has improved considerably. This is a result of significant expenditures to date on both infrastructure and technology, and robust regulatory systems that have proven to be, on the whole, quite effective." The commission reported that all urban sewage treatment systems on the U.S. side of the lakes had implemented secondary treatment, as had all on the Canadian side except for five small systems. However contrary to federal laws in both countries, those treatment system upgrades have not yet eliminated Combined sewer