Backflow Prevention Program

The Backflow Prevention Program is designed to protect the quality of our municipal water supply from possible contamination..

The purpose of the Backflow Prevention Program is to identify existing or potential connections between the potable water system and any source of pollution or contamination. Once one is identified, the property owners and/or tenants are required to install proper backflow devices.

Frequently Asked Questions

What is a cross-connection?

A cross-connection is an existing or potential piping connection that may allow pollutants or contaminates to enter your drinking water when a backflow condition occurs.


What is ''backflow''?

Backflow is caused by changes in system pressures which causes the water to flow in reverse direction. This reversed direction of water flow may allow pollutants or contaminants to enter the drinking water system through cross-connections. There are two types of backflow: back-siphonage and back-pressure.


What is back-siphonage and its causes?

Back-siphonage can occur when water system pressure is reduced typically caused by an interruption of the water supply due to nearby firefighting, repairs, or breaks in water supply mains.  This type of backflow can cause water to be pulled from buildings and fixtures possibly allowing contaminants to enter the water supply main.


What is back-pressure?

When a system is operating at a higher pressure than the pressure in the water main, a back-pressure backflow condition can occur. This is typically caused by high-pressure pumps, temperature increases in malfunctioning boilers, elevated tanks or other systems that produce pressure. Back-pressure can force water in reverse direction and can push pollutants or contaminants into the drinking water supply.


What is a backflow preventer?

This mechanical device prohibits the backflow of water which prevents pollutants and contaminants from entering the drinking water system through cross-connections. Examples of testable backflow prevention assemblies used typically in commercial facilities for medium to high hazard processes include: reduced-pressure principle assemblies, double-check valve assemblies and pressure vacuum breaker assemblies. Non-testable devices used typically in residential properties for low hazard processes include: dual check valves and hose connection vacuum breakers.


Do swimming pools require backflow prevention?

Yes, when swimming pools are installed on residential properties, a dual check valve backflow preventer must be installed on the water service entrance just after the water meter.  All hose connections must be equipped with a hose connection vacuum breaker backflow preventer. These measures will help prevent contaminated pool water from entering the drinking water system should a back-siphonage condition occur during pool refills.  Connections to swimming pools within commercial facilities require a testable backflow prevention assembly.


Are testable backflow prevention assemblies requires to be tested and maintained?

Yes, they are required to be tested upon installation and at least once per year thereafter.  If the assembly fails its test, maintenance or repair is required immediately in order to keep the assembly in proper operating condition. The assembly must be retested immediately after any repairs, maintenance, or when the assembly has been removed and re-installed or has changed locations.


Why do backflow prevention assemblies require annual testing?

Backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear or fatigue. Therefore, backflow prevention assemblies must be tested at least once per year to ensure that they are functioning properly. This is necessary in order to sustain safe drinking water and is a requirement under City By-Law P-102.


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

The property owner or water customer is responsible to ensure that all backflow prevention assemblies within their properties are always functioning properly.


I received a letter from the City stating that backflow prevention reports are due for my property. What am I required to do?

The City of Moncton requires annual reports showing that all backflow prevention assemblies have been tested and are functioning properly.  The Building Inspection department sends annual notices to customers advising when test reports are due for their facility. Property owners are responsible for contacting a backflow prevention testing company to schedule and have the testing completed.


Who can test backflow preventers within the City of Moncton?

Backflow prevention assemblies can only be tested by technicians who carry a current license issued by the Province of New Brunswick.  For a complete list of licenced backflow prevention testers, please refer to   For a list of companies that support the New Brunswick Backflow Prevention Association and typically have licensed backflow prevention testers on staff, please refer to   You may also refer to the Yellow Pages of the phone book under the plumbing category.


Once testing is complete, who is responsible for providing the reports to the City?

Ultimately, the property owner or water customer is responsible.  However, typically the backflow prevention testing company will forward a copy of the reports to the City’s Building Inspection department as part of their service. It is always good practice to keep a copy of the reports for your records.