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Backflow Prevention Program

Water Meter Installation Example CompressedWhat is backflow?

The water distributed through the Municipality’s water supply system is under constant and high pressure. In addition to maintaining the quality of the water, this pressure is necessary to move the water throughout the system and the hundreds of water service connections (a water service connection is where the Municipality’s distribution pipes or water mains connect with the private plumbing of homes and businesses). Backflow is the undesired reversal of water flow against normal direction that occurs as a result of backpressure or back siphonage. Backpressure results when the pressure in private water system is higher than the pressure in the Muncipality’s water supply system. An example of this situation would be when industries use pumps to circulate cooling water for equipment. Back siphonage can occur when there are dips in pressure in the system. An example of this situation is when there is a water main break.

If chemicals, pollutants, toxic substances, bacteria, pathogens or non-potable water are in the property’s water supply system, they may enter the public water supply system due to backflow. This may result in contamination of the public drinking water supply.

Why do we need a backflow preventer?

The Safe Drinking Water Act and regulations of the provincial Ministry of the Environment require the Municipality to provide safe drinking water to its residents. In order to meet this requirement, By-Law 63-12 takes a proactive approach towards preventing the contamination of water in the waterworks and includes a program for backflow prevention to ensure the safety of the drinking water.

A building permit is required for the installation of all premise isolation backflow preventers regardless of the size of the water service connection.

All installations of the premise isolation devices and all related items should be done in accordance with the Building Code, Canadian Standards Association (CSA) –B64 series standard, Municipal Code Chapter 851 and manufacture’s specifications.

Before any installations, tests or surveys are conducted for the premise isolation backflow prevention program, the authorized person as per the authorized function list in Schedule E of By-Law 63-12, must submit a copy of all the required documentation to the backflow prevention program in order for the installation, test and survey to be recognized for commercial and multi-residential properties.

Who can install backflow preventer devices?

A moderate or high hazard backflow preventer must be installed and certified by an authorized person on the municipal approved list of plumbers. For a complete list of approved plumbers, click here.

For the residential required backflow (dual check valve) you are not required to use a plumber off of the municipal approved list.

Who pays for the installation of the backflow device?

The approved backflow prevention device(s) may be supplied by the Municipality at cost to the owner or a CSA approved device that meets Municipal standards may be purchased directly by the owner. The owner is responsible for installation and maintenance of the backflow prevention device(s) and all associated costs as per By-Law 63-12.

What is cross-connection?

Cross-connection is any actual or potential connection between a potable water system and any source of pollution or contamination and includes any by-pass, jumper connection, removable section of pipe or hose, swivel or changeover device, private hydrant connections and any other temporary or permanent connecting arrangement through which backflow may occur.

What is a cross-connection survey?

A cross-connection survey is a complete review of the potable water system or systems located on a property to determine the presence of any existing backflow prevention devices, existing and potential cross-connections, corrective measures and recommendations. This survey must be completed by an authorized person on a Municipally-approved list. Please contact Water/Waste Water Clerk at  or call 613-258-9569 ext. 159.