Backflow Prevention

City of Moncton Backflow Prevention Program

What is a cross-connection?

A cross-connection is a permanent or temporary piping assembly that may allow your drinking water to become contaminated if a backflow condition occurs.

What is “backflow”?

Backflow occurs when the water flows in the opposite direction from its normal flow. The cause of a backflow is a change in pressures. This reversed direction of water flow may allow contaminants to enter the drinking water system through cross-connections.

What is back-siphonage and its causes?

Back-siphonage can occur when the pressure is reduced in the water main allowing a siphon to start and contaminants to enter the main. This may be caused by an interruption of the water supply due to nearby firefighting, repairs, or breaks in water supply mains.

What is back-pressure?

When a system is operating under a higher pressure than the pressure in the water main, a back-pressure backflow can occur. This forces the contaminants into the drinking water. The cause of back-pressure backflows is by high-pressure pumps, temperature increases in boilers, elevated tanks or other systems that produce pressure.

What is a backflow preventer?

This mechanical device prohibits a backflow of contaminants from getting into the drinking water. Examples of testable backflow preventers used for medium to high hazard processes include: reduced-pressure principle assemblies, double-check valve assemblies and pressure vacuum breaker assemblies. Non-testable devices used for low hazard processes include: residential dual check valves and hose connection vacuum breakers.

Who is responsible for the testing and maintenance of the backflow prevention device?

It is the responsibility of the customer to ensure that the backflow prevention device is always in satisfactory operating conditions. Testing of the backflow prevention devices must be done at the time of installation and on an annual basis thereafter. The device must be retested if any maintenance or repairs are performed on it. The City of Moncton Building Inspection department will send a notice to the customer advising them when an annual test is required on the device.

The customer must contact a licensed plumber who has a license to complete backflow testing. All test results must be submitted to the Building Inspection department.

Will a backflow preventer affect my water pressure?

Yes, essentially all backflow preventers cause some degree of pressure loss. The typical pressure drop across a preventer depends upon the type, make, size and location of the device. Refer to the manufacturer’s literature for more information.

Do swimming pools require backflow prevention?

Yes, backflow prevention devices must be installed on the City water supply. The pipe or hose connection must be equipped with a hose connection vacuum breaker valve to help prevent contaminated pool water from entering the drinking water system should a back-siphonage condition occur.

Why do I have my backflow preventer valve tested annually?

Backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear or fatigue. Therefore, backflow preventers have to be tested regularly to ensure that they are functioning properly. Typically, backflow preventers are tested once a year, or upon moving of unit from one area to another.

Is a plumbing permit required when installing a backflow preventer?

Any plumbing alteration related to the installation of a backflow preventer will require a plumbing permit. For permit information or inquires, contact the Building Inspection department at City Hall at 506-853-3470. For confirmation of plumbing permit fess, please refer to municipal by-law #1302, section 22.

Who can test backflow preventers?

Backflow prevention assemblies can only be tested by technicians who carry current certifications as a “Certified Backflow Prevention Assembly Tester.”

I received a letter stating that my backflow preventer is due for testing. What am I required to do?

We would suggest that you contact the certified backflow assembly testing company of your choice.

All work must be completed by a licensed plumbing contractor and tester.