Backflow

Backflow Program

ENWIN and Windsor Utilities Commission (WUC) work hard to ensure our community’s water is clean and safe. To do that, we enforce Windsor Utilities Commission By-law 96, which requires properties to install and maintain backflow prevention devices. These devices help prevent cross contamination on our water system.

What is Backflow?

Backflow is when water flows in the opposite direction from normal. It can happen during a water main break, weather event, industrial size drainage or pressure drop —and can draw contaminants into the drinking water system through a cross-connection (an unintended link between clean water and a source of pollution).

To prevent this, certain commercial, industrial and institutional properties are required to install and regularly test backflow prevention devices.

What is a Backflow Preventer?

A backflow preventer is a mechanical device that stops contaminated water from flowing back into the public water system. These devices are installed on the water service line and are tested annually by a certified professional to make sure they’re working properly.

Backflow devices have moving parts and are not maintenance-free. Annual testing by a certified plumber is required.

Why WUC Requires This

Backflow can pose serious health risks by contaminating the drinking water system. Under By-law 96, ENWIN requires properties at risk of contamination to install and maintain proper protection. This helps safeguard everyone’s water — at every tap.

Property Owner Responsibilities

If your property is subject to By-law 96, you are required to:

  • Install an approved backflow preventer
  • Have it tested annually by a certified backflow tester
  • Ensure the tester submits the test results to ENWIN through the online portal within 7 days

If your property is residential and not subject to the by-law, you may apply for an exemption.

Backflow Portal

Certified backflow installers and testers must submit all test results through the Windsor Utilities Commission Backflow Portal

WUC Approved Certified Backflow Testers

The WUC Approved Certified Backflow Testers list includes plumbers and contractors who are certified to test backflow prevention devices in accordance with Windsor Utilities Commission By-law 96. Only testers on this list are authorized to perform and submit compliance testing for affected properties.

If your plumber or contractor is not currently listed, you can ask them to apply for approval to be added to the list.

How to Apply

Frequently Asked Questions

What is meant by “degree of hazard”?

This refers to the risk level of contamination. Higher-risk properties require more robust devices.

What are premises and zone isolation?
  • Premises isolation: Protects the entire building and is installed where the water service enters the building.
  • Zone isolation: Protects specific areas within a building.
Why do I need a Backflow Prevention Device (BPD) if I don’t have wastewater or a non-potable device connected?

Even without wastewater or a non-potable connection to the water service, risks exist from irrigation, fire suppression systems, or hose connections. A BPD protects against all potential cross connections.

Are low hazard properties required to comply with the Backflow Prevention Program?

Yes. All industrial, commercial, institutional (ICI), and certain residential properties are required to comply with the Backflow Prevention Program, regardless of their assessed hazard level.

Properties classified as low hazard—those presenting a minor risk of contamination may be eligible for a three-year plumbing survey renewal cycle, rather than the standard annual review. This determination is made by WUC based on the degree of hazard and compliance history.

To confirm eligibility and ensure compliance:

  • A certified tester must complete an initial plumbing survey.
  • The survey must be submitted to WUC for review and approval.
  • WUC will determine the appropriate testing and renewal schedule.
Why was my water disconnected?

Water may be shut off due to:

  • Non-compliance with backflow requirements
  • Unpaid bills
  • Safety concerns or leaks
How can I get reconnected?

Contact ENWIN to:

  1. Resolve outstanding issues
  2. Pay applicable fees
  3. Schedule reconnection
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plumber doing install

Contractors: Please use the Windsor Utilities Commission Backflow Portal below.