What backflow prevention is, in two sentences
A backflow preventer is a one-way valve assembly that stops non-potable water (irrigation, boiler, mechanical fluids) from being siphoned backward into the municipal drinking-water main during a pressure event. Across BC, municipalities require that every installed assembly be tested annually by a certified Cross-Connection Control Tester and the test report filed with the city 1.
Who's affected (most BC stratas, quietly)
- ✓Any building with an irrigation system tied into the domestic water line
- ✓Any building with a boiler, hydronic loop, or glycol heating system
- ✓Buildings with a fire sprinkler service (most low-rises and all mid- and high-rises)
- ✓Buildings with a shared mechanical room, pool, hot tub, or commercial-style laundry
In practice that's the vast majority of strata corporations in Metro Vancouver, Victoria, Kelowna, and Nanaimo. Townhouse complexes with shared irrigation are affected even though individual homes are not.
What gets tested, and how often
Each individual assembly is tested annually — and many stratas have more than one. A typical mid-rise might have three: one on the irrigation line, one on the fire service, and one on the boiler. Each test takes 20–40 minutes and produces a city-format test report that the contractor files with the municipal program on the strata's behalf.
| Assembly type | Where it lives | Test frequency |
|---|---|---|
| DCVA (Double Check) | Most irrigation, fire | Annual |
| RPBA (Reduced Pressure) | Boilers, chemical hazards | Annual |
| PVB (Pressure Vacuum Breaker) | Some irrigation | Annual |
Who can test
BC requires the tester to hold a current Cross-Connection Control Tester (CCCT) certification through ASTTBC, BCWWA, or AWWA, and to use calibrated test equipment recertified annually 2. The plumber who installed the assembly is not automatically certified to test it. A general plumbing licence is not enough.
The most common failure mode is a missed irrigation-assembly test the year after a landscaping contractor change. The old landscaping company quietly handled the test; the new one assumes the strata books it directly. We've seen councils get shutoff notices because no one filed for two seasons in a row.
What it typically costs
| Scenario | Typical annual cost |
|---|---|
| Single DCVA (just irrigation) | $180–280 |
| Two assemblies (irrigation + fire) | $280–450 |
| Three+ assemblies (irrigation + fire + boiler) | $420–700 |
| Replacement (failed assembly, parts + labour) | $600–1,800 each |
Lower Mainland 2025–26 quotes; includes test, city-report filing, and on-site visit within a single mobilization window. Replacement costs are separate.
When StrataNotes will cover this
Backflow is among the most common ask in our intake — we expect to open commercial matching in Summer 2026, focusing first on Metro Vancouver and Victoria (where municipal programs are most active). The intake will ask how many assemblies you have and where they live; we'll match to CCCT-certified testers in your area.
Subscribers get first pick of contractors when we open early access. Subscribe here.
References
- 1Metro Vancouver, Drinking Water Conservation & Cross-Connection Control. Member-municipality programs administer testing locally (e.g. City of Vancouver, City of Surrey, Burnaby).
- 2ASTTBC, Cross-Connection Control Tester (CCCT) program. Certification lookup: asttbc.org.