Annual backflow preventer testing: what the test is and what you get

What annual backflow testing is

Backflow testing (some people call it a backflow inspection or a backflow device test) is the same annual check under the same by-law; the words vary, the test does not. Your building draws water from the Region's main. Somewhere near where the service enters, usually by the meter, there is a mechanical assembly that lets water flow in and never back out: the backflow preventer (in the trade, a backflow prevention assembly). It protects the drinking water main from anything in your building's plumbing: boiler treatment chemicals, dish machine detergent, irrigation water, process water. Because it is mechanical, it wears. Because it wears, Regional Municipality of Durham By-law 24-2018 requires it to be tested every year (section 6.3), by an authorized tester, at the owner's expense.

The test itself is a set of pressure readings. A calibrated differential pressure gauge is connected to the assembly's test cocks and each check valve, and the relief valve if there is one, is confirmed to hold against reverse flow at or above the minimum values in the CSA B64.10.1 standard. Pass or fail, the readings go on a report. The report goes to the Region through BSI Online, the company that administers the program on the Region's behalf.

Who has to have it done

Section 3.1 of the by-law applies it to all industrial, commercial, institutional (ICI) and multi-residential properties supplied with Regional water. Multi-residential means a building with more than six self-contained units (section 1.1). Residential occupancies, meaning single-family and small residential buildings, are excluded. If your property is any of these, the annual test applies:

• Offices, retail plazas, restaurants, clinics, warehouses, and every other commercial building
• Factories, plants, workshops, and industrial sites
• Schools, places of worship, community and government buildings, care facilities
• Apartment buildings, condominium corporations, townhouse and co-op complexes over six units

The requirement is identical in Oshawa, Whitby, Ajax, Pickering, Clarington, Uxbridge, Scugog and Brock. There is one program, run by the Region. See who needs testing for the property-type view and service areas for the municipality view.

What a test visit involves

Full detail, including a "what to have ready" checklist, on how it works. In short: the tester finds the assembly, confirms it matches the Region's record (make, model, serial, size, location), closes the shut-off valves to isolate it, takes the readings, restores water, tags the device, and files. Water is off only to that line, only for the readings.

What you get

What happens if the device fails

Some do. Debris on a check disc, a worn seat, a weak spring, a relief valve that will not seat. Under section 6.4 of the by-law, when a test shows a device is not in proper working condition, the authorized tester gives written notice to the Region and the area municipality within 24 hours, and repairs or replacement proceed immediately at the owner's expense. Repairs are plumbing work: they are done by a licensed plumber. We coordinate that through a licensed plumbing partner, then retest the device and file the passing report. Costs, timelines and the common repairs are on the failed test page.

What it costs

We quote per property. Price depends on how many devices, what type, where they are, and when the test has to happen. Testing in the GTA is commonly quoted from around $360 per device by some providers; the working range for commercial devices in Ontario is wider, and multi-device buildings get per-device pricing. Whatever the number, a good quote says whether the $25 BSI filing fee is included (ours is), what happens on failure, and who files the report. The cost page goes through all of it.

Who does the testing

Testing is performed by an OWWA-certified cross-connection control specialist registered with Durham Region’s backflow prevention program through BSI Online.

Every tester on the Region's program has passed a cross-connection control course, holds an OWWA certificate or approved equivalent, registers with the Region every year, and tests with equipment calibrated to the standard (by-law sections 8.2 to 8.6). You can check any tester against the Region's authorized tester registry. What we add is the coordination: booking, access, filing, records, and reminders, done the same way every year.

What we do not do

• Five-year cross-connection surveys. Appendix A of the by-law reserves surveys for licensed master plumbers, professional engineers and certified engineering technologists. If your notice asks for a survey rather than a test, we will say so and point you to who can do it.
• Fire sprinkler line devices. Section 9.1 requires personnel approved by the Commissioner, and isolating a sprinkler system is a Fire Code impairment. Not in year one.
• Single-family homes. Outside the by-law's scope.
• Repairs ourselves. Licensed plumbing partner, coordinated by us.