Backflow preventers: what the RBQ requires of building owners
The RBQ requires building owners to install backflow preventers and have them tested every year by a certified verifier. In the RBQ’s own words, existing buildings that are entirely residential “with fewer than 9 units or fewer than 3 storeys” are excluded from these obligations.
Updated
What a backflow preventer is, and is not
According to the RBQ, a backflow preventer — DAr in Québec’s French terminology — is a mechanical device made up of two check valves, designed to protect the drinking water supply network.
The RBQ describes the risk it prevents. A potentially polluting source coming into contact with drinking water creates a cross-connection. Back-siphonage occurs during a backflow caused by a pressure loss in the network; back-pressure, when a device or piece of equipment runs at a higher pressure than the network.
It also states that a check valve is not a backflow preventer and is not effective protection.
Which buildings are covered
The obligation applies to buildings generally, unless excluded. The RBQ words it this way: existing buildings that are entirely residential “with fewer than 9 units or fewer than 3 storeys are excluded from these obligations.” If you are unsure about your building, ask the RBQ.
The owner must install backflow preventers at the building’s water entry and wherever there is a risk of contamination. The devices must be approved to CSA B64 and installed to CSA B64.10.
The annual test and the record
Installing the device is not enough. The RBQ requires the owner to:
- have the backflow preventers tested at installation, then every year;
- entrust the tests and maintenance to a certified verifier — the provincial registry of backflow-preventer verifiers, hosted by Réseau Environnement, lets you find one;
- keep a record containing proof of the tests carried out.
What the owner risks
According to the RBQ, failing to comply exposes the owner to penal prosecution. And if contamination of the network comes from a building, the owner may face criminal prosecution and have to pay the cost of cleaning the network.