Water quality information is tightly monitored in Ontario, following the Walkerton tainted water tragedy in 2000 and the recommendations of the O'Connor report of 2002. Municipalities are now required to report annually on the quality of their drinking water and to make this information public on their municipal websites.
What follows is a select list of potential data sources for water treatment plants organized by level of government. The Appendix contains details about each of the sources listed below, as well as additional sources of information.