Backflow prevention requirements in Hamilton

Who has to comply in Hamilton

Hamilton runs its own backflow program under the Prevention of Backflow By-law 10-103, passed on May 12, 2010 and amended in 2019. It applies to every industrial, commercial and institutional property and to multi-residential buildings of four storeys or more. Hamilton is a single-tier city: it is not part of Halton Region, and Halton's program does not apply here.

The Ontario Building Code's plumbing part (Part 7) and the CSA B64 standards also apply. The municipal by-law adds the program around them: who is surveyed, how often each device is tested, where the report goes and by when.

Two kinds of survey

The by-law sets the survey by the size of the water service.

• A Self-Assessed Survey, which the owner completes on the City's form, for a service of 38 mm (1½ inches) or smaller. There is no fee. Where more than one business shares the property, a survey is completed for each business.
• A Cross Connection Survey by a contractor registered with the City, for any larger service. The by-law's threshold is above 38 mm, while the City's program page says 50 mm or larger. For a service between the two, we confirm with the City which survey applies. The City can also require one after a Self-Assessed Survey. The signed original and the City's fee are delivered within 14 days of the survey.

Both are repeated every 5 years. A new survey is also due within 30 days of a change in the hazard level, the ownership, or the equipment the last survey covered.

Installation and testing

The City's survey acknowledgement states the hazard level, in the by-law's terms, and the hazard level sets the device:

• a reduced-pressure assembly (RP, also called an RPZ) for a high or severe hazard;
• a double check valve assembly for a non-health hazard such as a fire sprinkler system (the by-law allows either device on a fire service);
• a double check detector assembly where the City's program page calls for one, on a moderate-hazard fire service.

The contractor installs the device on the water service downstream of the meter, under a building permit, and performs the initial test.

Every device is tested at installation, every year, whenever the City asks, and after any replacement, relocation or repair. The tester delivers the report and the City's fee within 14 days of the test. The tester also files a calibration certificate for the test kit with the City every year.

A permit for a new device in Hamilton

The City requires a building permit for every backflow preventer installation. The Building Division at City Hall, 71 Main Street West (905-546-2720), issues it. The owner or an agent applies through the City of Hamilton Customer Portal at my.hamilton.ca and pays the fee at application. The application gives the licence number of the contractor doing the work. The fee schedule lists $291 for the first premise or zone backflow preventer and $187 for each additional one (Schedule A to Building By-law 15-058, as amended in January 2025). No 2026 schedule had been published when this page was checked, so the amount is confirmed at application. After the initial test, the Building Division is called to schedule the device inspection, which the City's fee table lists at $190.69 in regular hours.

Who can test

Only persons with the qualifications in Schedule A, the by-law's Authorized Functions List, may survey, install, relocate, replace, repair or test a device. Each qualification covers only the functions listed for it. Registration with the City is annual. The master plumber or professional engineer registers the company's testers in person at 330 Wentworth Street North, with the test-kit calibration certificate. For a fire-protection company the master sprinkler installer registers. The City issues one registration number for all of them. A company whose licences are not kept up to date is classed as inactive and cannot submit documents under its number. The City publishes an Approved List of Contractors.

Working with us in Hamilton

Hamilton accepts surveys, installations, repairs and tests only from contractors registered with its Backflow Prevention Program. Send us the notice and we confirm the next step. Our certificates are listed on the Qualifications page.