As Canadians, we changed after May, 2000 when the unexpected happened. Now, Walkerton, Ontario means death and illness caused by negligence and criminality within our public drinking water system. Walkerton’s water was contaminated with cattle manure containing a virulent strain of E. coli bacteria. The manure didn’t enter the town’s wells because of an irresponsible farmer. It entered Walkerton’s water supply, undetected until sickness and death, because those responsible for the city’s water, Stan and Frank Koebel, didn’t understood the risk of E. coli contamination. They didn’t sample water correctly and they ignored results showing astronomical E. coli counts. Why did the Koebels, two high school drop-outs, hold responsibility for the safety of Walkerton’s water? Who checked Stan and Frank’s work? Where were the checks and balances provided by a concerned public, city council, the utilities commission, the water testing laboratory, the regional health office, the provincial Ministry of the Environment and Health Canada? Politicians, bureaucrats and engineers who design drinking water systems like to explain that a multi-barrier approach is taken to protect public drinking water. Even if one barrier is breached there are back-ups to protect public health. However, in the case of Walkerton, not only had barriers collapsed without sounding alarms, but warnings had been ignored. A 1996 Health Canada study cautioned that Walkerton’s drinking water was at high risk of E. coli contamination. Then provincial premier, Mike Harris, had recently and rapidly eviscerated the Ontario Ministry of Environment against the advice of senior Ministry officials who counselled that such deep, rapid cuts would risk public health. Local Ministry of Environment officials had not or could not carefully scrutinize Walkerton’s water sampling records which contained a pattern of falsification. The Ministry did not act on Walkerton’s repeated violations of drinking water treatment guidelines. The Regional Health Office wasn’t receiving copies of Walkerton’s water tests. City council and the utilities commissioners did not act as good public trustees and critically audit Stan and Frank’s work. Instead, councillors and commissioners behaved like the Koebel’s chums. They accepted, without question, misleading reports. Walkerton is full of lessons. We deceive ourselves when we assume the system is working. Drinking untreated water does not always lead to immediate death or illness and it may not affect everyone. E. coli is not the only or the greatest waterborne menace. Between 1817 and the 1900, six cholera pandemics killed mercilessly. In Chicago, during the 1849 outbreak, the death rate was 2,897 per 100,000. This was the worst death rate for any cause since Chicago began keeping health statistics – and Chicago wasn’t exceptional. By the beginning of the twentieth century, cholera had abated as we learned of germs, the fecal-oral route of infection and the science of drinking water treatment. But cholera and other waterborne diseases, hadn’t disappeared. They’re always in our waste, wildlife, soil, water and air. Their exclusion from drinking water requires education and continual vigilance. The definitive book on Walkerton, the one all Canadians and especially all elected representatives must read is the thirty-five page “A Summary Report of the Walkerton Inquiry” by the Honourable Dennis R. O’Connor. This is a concise chronology of the events that precipitated the disaster, an examination of where systems failed and recommendations to prevent future occurrences. For more detail than O’Connor’s Summary Report, try his full two volume report or “Well of Lies” by Colin Perkel. Perkel is a respected journalist who followed the Walkerton story from its beginning. In “Well of Lies” he offers easy-to-read historic context, how the disaster unfolded, and a view of Walkerton after the media left town.