Backflow Testing in Langley: Who Needs It, How Often, and What Gets Filed

Plumblink Crew

8/11/20266 min read

Backflow prevention assembly on an irrigation line at a Langley home.

Most homeowners find out they need backflow testing when a letter shows up from the municipality.

Most property managers find out when a tenant's water gets shut off.

Neither is a great way to learn it.

So here's the plain version: what backflow testing actually is, who's on the hook for it in Langley, how often it has to happen, and what happens if it doesn't.

What backflow testing is protecting against

Water in your building is supposed to travel one direction - in. Backflow is when it reverses and travels back toward the municipal main.

That matters because of what it can carry with it. A cross connection is any point where your drinking water piping meets something that isn't drinking water: irrigation lines sitting in fertilizer and animal waste, a boiler full of treated water, a hot tub, a soap dispenser on a janitorial sink, a hose left submerged in a bucket. Under normal pressure those are harmless. Reverse the flow and they become an inlet.

Two things cause the reversal:

Back-siphonage - pressure in the supply drops and creates a vacuum that pulls water backwards. A water main break, a hydrant opened for a fire, heavy simultaneous demand.
Back-pressure - pressure on your side climbs higher than the supply. A boiler, a pressure washer, a booster pump.

A backflow preventer is a one-way gate installed to stop it. Like anything mechanical with rubber seals and springs, it wears out - and it fails silently. There's no light, no alarm, no change at the tap. Testing is the only way to know it's still working, which is exactly why the testing is mandatory rather than optional.

Who needs backflow testing in Langley?

Two things determine whether you're required to test: what's connected to your water, and what the local bylaw says about your property.

Almost always required:

Commercial and industrial buildings
Restaurants and food service
Multi-family buildings, stratas and apartment complexes
Medical, dental and veterinary offices
Car washes, salons, laundromats
Agricultural properties - very relevant across the Township, especially where a property has both a municipal connection and a private well for irrigation
Any building with a fire sprinkler system
Any building with a boiler or hydronic heating loop

Often required on residential properties:

In-ground irrigation and lawn sprinkler systems - the single most common residential trigger
Hot tubs and pools with a fill line
Boilers and radiant floor heating
Water softeners and some filtration setups
Solar or recirculating hot water systems
Private well on the same property as a municipal connection

If you have a testable assembly installed, you're expected to test it. A useful distinction: a backflow device is generally non-testable, while a backflow assembly has test ports on it - those little brass fittings on the side. Test ports mean it's meant to be tested.

How often?

Annually is the standard, plus a test when the assembly is first installed, and again after any repair or relocation.

Some situations get tested more often - high-hazard commercial applications, or an assembly that's failed before. Irrigation systems are commonly tested at spring turn-on, which is a sensible time to do it anyway since that's when the system comes back under pressure after sitting all winter.

What actually happens during a test

It's quick and it isn't invasive. A certified tester connects a differential pressure gauge to the test ports, closes and opens the shutoffs in sequence, and measures whether the check valves and the relief valve hold within spec.

Water is off for a few minutes. On a typical residential irrigation assembly the whole visit is well under an hour.

You get a test report. The assembly gets a tag.

In BC, backflow assembly testers are certified through the BC Water & Waste Association, which is the recognized body for that certification province-wide. This isn't a task a general handyman can sign off on - an uncertified test isn't a test, it's a guess, and the municipality won't accept the paperwork.

Where the report goes

This is the step people miss. The test isn't finished when the tester packs up — it's finished when the report is filed with the water purveyor.

In the Township of Langley, backflow testing sits under the Waterworks Regulation Bylaw (2008 No. 4697, as amended), and test reports are submitted to the Township by the property owner or the certified tester. If your property is in the City of Langley or another municipality, the program is separate and the submission process may differ — worth a call to confirm which one you fall under, because the two are genuinely different jurisdictions and people mix them up constantly.

Either way: get a copy of your own report and keep it. If a device is later found untested, "my plumber did it" is a much weaker position than a dated report with a certification number on it.

When we test, we submit the report and send you the copy. You shouldn't have to chase either.

What happens if you don't test

It escalates in a predictable order:

A notice from the municipality
A follow-up notice, sometimes with a deadline
Water service shut off until a passing test is on file
Fines under the applicable bylaw

And if a contamination event traces back to an untested assembly on your property, liability is a real conversation. For a commercial property or a strata, that's the part worth taking seriously - the annual test costs a fraction of any of the alternatives.

Failed the test - now what?

A failed assembly usually doesn't need replacing. Most failures are worn rubber: check valve seats, springs, the relief valve diaphragm. Rebuild kits exist for the common models and a repair typically costs a lot less than a new assembly.

What does force replacement:

The body is cracked - usually freeze damage from an assembly that wasn't winterized or was left exposed
The model is obsolete and no longer approved, or parts aren't available
It's the wrong type of assembly for the hazard it's protecting, which occasionally comes to light on a first test

After any repair, the assembly is retested and the new report is filed. We do the repair and the retest in the same visit where we can, so you're not paying for two trips.

While we're on it: protect the assembly over winter

Freeze damage is the number one reason a Langley backflow assembly fails a spring test, and it's entirely preventable.

Drain and shut down irrigation systems before the first hard frost
Insulate any assembly in an exposed location, a crawlspace or an unheated garage
Don't blow high-pressure air through the assembly - it damages the internals
Turn it back on gently in spring and book the test at the same time

Frequently asked questions

Do I need backflow testing on a normal house with no irrigation?

Often not. If there's no testable assembly on the property, there's nothing to test. If you have irrigation, a boiler, a hot tub fill line, a water softener or a well alongside your municipal connection, you likely do.

How often does a backflow preventer need to be tested in BC?

Annually, plus at installation and after any repair or relocation. Some high-hazard commercial applications are tested more frequently.

Who is allowed to test a backflow preventer in BC?

A tester holding current certification through the BC Water & Waste Association. General plumbing or handyman work doesn't cover it, and the municipality won't accept a report from an uncertified tester.

How long does a backflow test take?

A typical residential assembly takes under an hour, with water off for only part of that. Larger commercial assemblies and multiple devices take longer.

What happens if my backflow test fails?

The assembly is repaired - usually a rebuild of the internal seals and springs rather than a replacement — then retested, and the passing report is filed with the municipality.

Who submits the test report?

In the Township of Langley the report is submitted by the property owner or the certified tester. We file it for our customers and send you a copy.

Can my backflow preventer freeze?

Yes, and it's the most common cause of a failed spring test. Drain irrigation systems before the first hard frost and insulate any assembly in an exposed spot.

Is a backflow preventer the same as a backwater valve?

No, and this one trips people up. A backflow preventer protects drinking water. A backwater valve is a sewer fitting that keeps sewage from backing up into your basement during a surcharge. Different device, different purpose, both worth having.

Book your annual backflow test in Langley

Plumblink handles backflow testing, repairs and new installations for homes, stratas, farms and commercial buildings across Langley and the surrounding Fraser Valley. Certified testing, the report filed on your behalf, and no call-out fees.

Call (236) 233-9696 or request a quote. If a device has failed and you're facing a shut-off deadline, say so when you call - we're available 24/7.