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Cross Connection Control Program

The Cross Connection Control Program is a joint effort by a variety of groups and professionals to reduce water contamination risks in water infrastructure where a link between our drinking water system and non-potable water is located.

The program oversees guidelines for controlling cross connections and ensuring compliance so that Calgary's drinking water supply is protected from contaminated water. This is done by preventing water that has been used for washing, heating, cooling, etc., within a facility or home from flowing into the drinking water system.

Do you have a question for the program team?
First, there are many links below that may answer your question. If you cannot find what you are looking for, use the 311 Online Service Request at this link Cross Connection Inquiries, and place your question. A team representative will respond within five business days.

Cross connection resources


For more information on cross connections guidelines, view the Water Utility Bylaw, the National Plumbing Code and the Canadian Standards Association B64 Series Standards.

Cross connection frequently asked questions

What is a cross connection?

A cross connection is a temporary or permanent link between a potable (drinking) water system and any source containing non-potable water or other substances from which backflow may occur.

Examples include the piping between a public water system, or a citizen's water system and a heating or cooling system, fire system or irrigation system.

What is a cross connection control device?

A cross connection control device is a mechanical device that prohibits backflow of water into the public drinking water. The main testable types of cross connection control devices are the reduced-pressure principle assembly, the pressure vacuum breaker assembly, the double-check valve assembly and registered Air Gaps. Examples of secondary types of devices are the hose connection vacuum breakers, atmospheric vacuum breakers and residential dual check valves.

Learn more about cross connection control devices in the brochures below:

What is backflow?

Backflow is the undesirable reversal of non-potable (untreated) water (or other substances) through an unprotected cross connection and into the piping of a public water system or a citizen's drinking water system.

There are two causes of backflow:

Backsiphonage: The reversal of normal flow in a system caused by a vacuum in the supply piping. This can also happen if there is an interruption of the water supply due to nearby fire-fighting, repairs or breaks in the water supply mains.

Backpressure: The reversal of normal flow in a system due to pressure higher than the supply pressure. This happens when there is an increase in downstream pressure caused by pumps, temperature increases in boilers, elevated tanks or other pressure-producing systems.

The regulations related to backflow and cross connections include the Water Utility Bylaw, the National Plumbing Code and the Alberta Amendments to the National Plumbing Code.

Why do cross connection control devices need to be tested?

cross connection control devices have internal seals, springs and moving parts that are subject to fouling, wear or fatigue; therefore, all cross connection control devices have to be tested to ensure they are functioning properly.

For more information, view the Cross Connection Testing and Inspection Report.

How do I test my cross connection control device?

The owner of the property or agent of the owner (property manager) as identified in the lease is responsible for testing. If the cross connection control device belongs to the tenant, then they are responsible.

To have your cross connection control device tested,contact a certified tester.

A certified tester is any individual who is registered with The City of Calgary Water Services as a Cross Connection Control Specialist within the mechanical industry (plumbers, irrigation, fire and sprinkler contractors, and mechanical contractors).

Please note: We do not accept reports from unregistered or unqualified testers. A test report received from an unregistered or unqualified tester will be returned and the device will be still considered untested.

What if I have received notice that I must install appropriate cross control assemblies?

Contract a City Qualified Trade Contractor who is a Cross Connection Control Tester and approved to obtain a plumbing permit to install the cross connection control devices. A plumbing permit is required to install a testable cross connection control device. For additional permit information, please contact Building Inspections.

What if I do not comply with testing or installation requests?

Failure to comply with the notification may result in a violation ticket, a water service cut-off and/or summary conviction as outlined in theWater Utility Bylaw.

A time extension can be granted - the request must be presented in writing to the Cross Connection Control Officer and will be individually assessed due to the factors involved (i.e., degree of hazard, type of protection etc.)

If you have further questions or need clarification, please contact 311.​​​