In May 2000, the unthinkable happened; individuals living in Canada became ill, some fatally, from drinking tap water contaminated with a toxic strain of Escherichia coli (e-coli). Walkerton, a small rural town in Ontario, Canada, was thrust into the spotlight as Canadians tried to understand how this could have happened. A public inquiry was struck to investigate the causes of the tragedy and make recommendations to ensure that it would not happen again. As a result, governments across Canada are taking a close look at how drinking water supplies are protected and managed.

This Article reviews the following questions: (1) what happened in Walkerton in May 2000?; (2) what caused the contamination?; and (3) what are its implications for groundwater protection law? In doing so, it focuses on the Walkerton Inquiry Report's source protection recommendations for Ontario and on the groundwater protection reforms of two provinces, British Columbia and New Brunswick.