Wells might be okay at a Muskoka cottage, but in most places, well water is highly polluted by local farming. Farming is one of the worst polluting industries, but gets a free pass because farmers have disproportionate political clout. Farms have killed lakes, and cost cities millions in water treatment plants to deal with their ground water pollution, but it's not politically correct to tell a farmer to stop ruining the environment for everyone else! Just look at Florida... Florida has spent $2BILLION cleaning up algae caused by fertilizer used in farms around lake Okeechobee, and it has cost the state's tourism industry billions more. There have been petitions for the state to just buy the farms to shut them down, but no... you can't tell farmers who are destroying the state's industry to stop using harm fertilizers. Likewise, you can't tell Canadian farms around the wells that supply Kitchener-Waterloo's city water supply to stop using harmful fertilizers.