The institutional and human failures that caused the lead contamination of Flint, Michigan’s water supply (see p. 14) are only the most recent examples of similar problems that have led to rare but lethal outbreaks in Canada and the U.S.

An E. coli outbreak contaminated the water supply of the small community of Walkerton, Ontario, in 2000, killing seven people and sickening thousands.

A far worse health emergency occurred in Milwaukee, Wisconsin, in 1993, when the city’s water supply suffered an outbreak of cryptosporidium that killed 69 people, most of them AIDs patients. The belief among water professionals is that the contamination occurred when a discharge of animal waste into Lake Michigan hit the plant’s intakes at the same time water plant operators were testing filters.