Walkerton water and complex adaptive systems.

About a year ago there was a major crisis about the water supply in Walkerton, a small Ontario Town in a farming area near Georgian Bay. In May 2000, there was a sudden outbreak of bloody diarrhea that affected up to half the town population of 5000, sent almost 900 people to get medical attention, hospitalized almost 100 of them and killed at least 7 people. It was shown that Escherichia coli 0157:H7 (E.coli) contaminated the water supply and that a "boil water" directive was sent to the town’s population only after people had become ill. There was a public outcry and a series of government responses, including a public inquiry into the circumstances surrounding these events.