I grew up in a small city on the dry prairie of Canada. The water source for our city was Buffalo Pound Lake, some 30 kilometres north of town. However there was a problem with the water from the lake. In the 1930's and 1940's farmers dumped their excess fertiliser in the lake. This meant that rich crops of algae bloomed in the lake. For much of the spring, summer, and autumn, the lake would be green from the algae. During the late summer though, the algae would bloom and produce many seeds. The city's water filtration plant had to use extra chlorine to kill whatever came from our taps. The water from the lake became almost undrinkable because of the awful stench. Our shower water stank. We boiled water on the stove for drinking and cooking, hoping to remove some of the horrible smell. Eventually, the city put a heavy duty carbon filtration system in which made the water smell better. But for us during those weeks in August, we always wondered what was in the water we drank.