We monitor the safety of public drinking water. If there is a threat to safe water, we may issue a water advisory.
Municipal water systems
Waterworks are managed by cities and towns. Ministry of the Environment and Climate Change inspectors ensure that water is treated, sampled and monitored on a regularly. Any adverse results are reported to us and to the Ministry of the Environment and Climate Change. If water does not meet the Ontario Regulation 169/03 Ontario Drinking Water Quality Standards, we may issue a water advisory. For all water test results and other water supply information, contact your local waterworks department or Public Utility Commission.
Small drinking water systems include restaurants, campgrounds, seasonal trailer parks, summer camps, community centres, libraries, gas stations, motels and churches. We inspect these systems for water quality under Ontario Regulation 319/08.
Small drinking water systems documentation and requirements
The Ministry of Health and Long-Term Care provides guidance documents, fact sheets and Ontario Regulations for small drinking water systems.
The Government of Ontario Central Forms website provides the following small drinking water systems forms:
- 4578 – 64E Lab services notification form
- 4579 – 64E SDWS identification form
- 4580 – 64E Notice of adverse test results/issue resolution form
- 012-1806 Well record request form
The Medical Officer of Health issues a water advisory when there is an existing or potential threat to a public drinking water supply. A threat could be an adverse test result, a break in a water main or flooding.
Water advisories are removed when the problem is fixed and test results show the water is safe.
Water advisories may last for any length of time. If you have questions about when the water advisories will be removed, contact your municipality or water system operator.
The following fact sheets provide instructions on what to do during a Boil Water Advisory:
- How to Use Your Water Safely (for the general public)
- Food Establishments
- Healthcare Institutions
- Dental Offices
The following fact sheets may be given with a Health Information Advisory:
- Sodium in Drinking Water
- Fluoride in Drinking Water
- Nitrates in Drinking Water