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Example of how backflow can occurBackflow is the reverse flow of a liquid into the drinking water supply.

Backflow from an industrial or commercial property that uses harmful substances could pollute the local water supply.

For example, a hose left running in a container of toxic chemicals could result in harmful backflow. A sudden drop in water pressure could cause the liquid to be siphoned back through the hose and into the water supply.

The installation of a backflow prevention device protects the water supply from this very serious situation.

Commercial and trade waste customers

If you’re a commercial or trade waste customer you must provide a backflow prevention device immediately downstream of your water meter.

Without a backflow prevention device, you risk:

  • causing serious illness or death
  • prosecution under the Water Act 1989
  • substantial financial losses and litigation (such as Workcover, and Occupation Health and Safety claims)
  • being disconnected from the water supply.

Installing a device

It's the property owner's responsibility to make sure that a suitable backflow device is properly installed and tested. Only plumbers with a Water Supply license are qualified to install a device.

Here's what you need to do:

1. Get a risk assessment

Arrange for an accredited plumber to assess the potential onsite hazards of your property.

The hazard ratings are:

  • High hazard - potential to cause death.
  • Medium hazard - potential to endanger health.
  • Low hazard - constitute a nuisance but not endanger health.

2. Choose and install a device

Your accredited plumber will recommend and install a suitable device based on your property's hazard rating. If installing a device in a medium or high hazard area, your plumber must be licensed in Backflow Prevention.

3. Test your device

Medium and high hazard devices need testing annually by a plumber licensed in Backflow Prevention. Results must be lodged within 28 days to either Coliban Water or Coliban Water's agent:

CIS Services Pty Ltd
4 Florence Street Burwood VIC 3125


Last updated on 21 Feb 2023
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