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Backflow prevention for plumbers
Assessing, installing and testing devices
Licensed plumbers and accredited backflow plumbers must follow a strict procedure to help our customers fulfil their backflow prevention obligations. We have a guide that provides information for backflow prevention (1MB) containment and a collection of frequently used Backflow prevention terms (66KB).
When a site needs backflow containment
All connections to our water mains must have suitable backflow containment as set out in our policy, Your responsibilities when connected to our services (358KB).
What plumbers must do
Licensed plumbers must assess each site to work out its specific backflow containment needs.
If you've determined the site's hazard rating as low, our 20 mm and 25 mm water meters already have a simple backflow prevention device in them. If the property's water meter is larger than 25 mm, you'll need a separate backflow device. Find out more about meters and metered standpipes.
You must advise the property owner of the backflow requirements and install a backflow prevention device appropriate to the property's hazard rating. You must also tell the owner if the device needs to be tested each year.
What to know about fire services
All fire services, fire hydrant and sprinkler services require the installation of a Double Check Detector Assembly (DCDA).
The materials used on the upstream side of the DCDA and including the outlet control valve must be WaterMark approved for plumbing and drainage installations.
There can be no galvanised pipe and fittings on the upstream/inlet side of the containment device.
- All rising spindle valves must be WaterMark approved.
- All butterfly valves must be WaterMark approved and gear operated.
If you need further information, email us at backflow@sydneywater.com.au.
Who to contact about zone and individual devices
We no longer accept reports for zone and individual backflow devices. Contact NSW Fair Trading if you have questions about these types of devices.
Who can install or test backflow prevention devices
Only licensed plumbers with backflow prevention accreditation issued by a registered training organisation (backflow plumbers) can inspect, commission and test medium and high hazard backflow devices.
Once backflow devices have been installed, only backflow plumbers can test them. Once a test has been done, backflow plumbers must submit the test report using our online lodgement system.
Why you need to retain photos for each lodgement
We now audit lodgements.
As part of our audit, we may ask you to provide 2 photographs for any backflow containment device test you've registered with us. The photos need to show:
- the backflow device you tested with the serial number clearly visible
- the test kit you used.
You don't need to attach photographs to your test reports when you upload them using the new backflow prevention application. However, your uploaded test reports may be subject to an audit. If we audit your lodgement, we'll send you an email asking you to email the photographic evidence to us as proof.
How to submit a backflow test report
Use our online lodgement system to submit your backflow test report. To access the system for the first time, you'll need to register for backflow prevention using your personal email address. If you can't access the system, email us at backflow@sydneywater.com.au.