Backflow testing is one of those compliance jobs that quietly comes around every year and catches people out when a reminder notice arrives. Here is what a backflow device actually does, who is required to have one, and what the annual test involves, in plain English.
TL;DR
A testable backflow device stops contaminated water siphoning back into the drinking supply. In NSW, testable devices must be tested and certified every 12 months by an accredited plumber and the result lodged with your water authority. Higher-risk properties (commercial, bores, irrigation, pools) are the ones that need them.
What backflow is, and why it matters
Your home’s water is supposed to flow one way: from the clean mains into your taps. But if pressure in the mains drops suddenly, from a burst main, heavy use, or firefighting nearby, water can be sucked backwards out of your property and into the shared supply. If that backwards-flowing water has been near a contamination source, like garden chemicals through an irrigation line, pool water, or a bore, it can pollute the drinking water everyone shares. A backflow prevention device is a valve that physically stops that from happening.
Testable devices need an annual test
Not all backflow protection is the same. Simpler, lower-risk situations use non-testable devices that just sit there and work. But medium and high-risk situations use testable devices, and the law treats those differently: the internal parts wear, so a testable device must be tested every 12 months by a plumber who holds backflow accreditation, and the result has to be lodged with your water authority. Miss the test and you can end up with a non-compliance notice.
Who actually needs one?
Backflow requirements come down to the contamination risk at your property. The ones that typically need a testable device include:
- Commercial and industrial premises, which is the most common case.
- Homes with a bore or rainwater tank plumbed in near the mains supply.
- Irrigation and reticulation systems connected to the drinking water.
- A swimming pool with an automatic top-up from the mains.
- Properties with a fire service connection.
A standard low-risk home with none of those often only needs simpler protection at the meter. If you are not sure which camp you are in, we can assess the property and tell you.
What the test involves
It is a quick job for a licensed tester. We isolate the device, connect a test kit, check that the valve and its non-return mechanism hold pressure the way they are meant to, and record the readings. If it passes, we issue the certificate and lodge it with the water authority so your record stays current. If it fails, the device usually needs a service or a part, which we can sort, and then retest.
Donza Plumbing installs, repairs and carries out the annual test and certification on testable devices. If you have had a reminder, or you are not sure whether your property needs one, request a callback or see our backflow prevention service.