Canada's abundant surface water, so prominent on maps of the country, is not always located where people need it most. One in three Canadians depends on groundwater. Drinking water quality is regulated separately by each of the provinces and territories, but there are common elements in the various policies. In general, Canadians select the highest-quality supply and protect it or remove the potential sources of contamination. Problems a utility may have meeting the water quality guidelines established by the province are addressed with a cooperative abatement strategy. In this article the authors review regulatory policies, water sources, contamination problems, and treatment strategies for each of Canada's provinces and territories. Includes table, figure.