Skip ribbon commands
Skip to main content

A cross connection is a piping arrangement that allows a potable water system to be connected to a source of potential pollution or contamination. It's very important to protect cross connections in order to prevent backflow into potable water. Ultimately, backflow can cause the contamination of the entire public water supply, posing a risk for anyone using water for drinking, cooking, bathing or any other purposes.

If there's an incident resulting in contamination of public drinking water (due to improper or unprotected plumbing connections), the owner responsible or occupant of the property can be held liable for damages.

Preventing backflow

To comply with the Canadian Standards Association (CSA B64.10), the National Plumbing Code of Canada, and City of Edmonton Bylaw 19626 property owners must do the following to prevent backflow:

  • Remove any unnecessary cross connections and isolate your water system from the public's.
  • Protect cross connections that can't be​​ eliminated with an approved backflow prevention device or assembly.
  • Ensure that all testable backflow preventers are tested annually by a certified tester, and all non testable devices are visually inspected.

Backflow prevention assemblies

The type of device required for premises isolation of a commercial, industrial, or multi-residential property is based on how hazardous it could be to the public drinking water: ​​

​Severe degree of hazard

Examples of facilities in this category

  • Automotive repair shops
  • Hospitals
  • Dry cleaning plants
  • Car washes
  • Labouratories
  • Mortuaries

Required assembly

Reduced Pressure principle backflow preventer (RP)


​Moderate degree of hazard

Examples of facilities in this category

  • Restaurants
  • Schools
  • Hotels
  • Commercial office spaces
  • Shopping malls
  • Apartment buildings

Required assembly

Double Check Valve Assembly (DCVA)

cross-connection-double-check-valve.jpg ​​

Consult with a certified backflow tester or our CCC Department to determine the appropriate protection. Residential homes can also play their part in preventing backflow.

Cross Connection Control Program

Our Cross Connection Control Program helps Edmonton's commercial and multi-residential property owners meet various bylaws and standards in relation to backflow prevention. It's a cooperative effort between plumbing and health officials, water purveyors, property owners and certified testers. Together, we establish and administer guidelines for controlling cross connections, ensure their enforcement and make sure the public potable water supply will be protected.

Learn more about EPCOR's Cross Connection Control Program. ​​