Backflow is caused by a sudden drop in pressure in the supply pipe, or when the pressure from a property’s pump is higher than the pressure in the supply pipe (often due to pressure drop in the supply).
How does backflow cause contamination?
Backflow can lead to contamination of the water supply through:
- A hose left running in or through a container with chemicals in it
- Equipment connected directly to the water mains using water to mix chemicals
- Cleaning processes using clean-in-place systems involving chemical or biological substances
- Equipment using recycled water
- Cooling towers and heating systems
What are considered high risk activities?
- Animal processing (abattoirs)
- Metal finishing and coating
- Car and plant washing
- Commercial laundering
- Food processing
- Mixing or diluting agricultural sprays
- Irrigation systems with direct injection of fertiliser or pesticides
- Using toxic chemicals (hospitals, mortuaries)
- Other industrial processes
- Other as specified in Australian Standard AS3500
How can I prevent backflow happening?
There are several ways to prevent backflow from occurring:
- Assess your property to identify any backflow risks - specific advice is available from a licensed plumber registered to install backflow devices.
- Install appropriate backflow prevention devices - these must be installed by a licensed plumber, installed in accordance with the Australian Standard For Backflow Prevention (AS3500) and approved by Central Highlands Water.
- Arrange maintenance and testing of backflow prevention devices by a backflow prevention certified plumber as part of an annual maintenance program. Forward the results of testing to us within 30 days.
What are the property owner’s responsibilities?
Property owners are responsible for ensuring activities carried out on their property does not lead to contamination of the water supply.
If contamination occurs, the occupier of the property found to be responsible could face legal action and risk to their reputation.
Who do I contact for more information about backflow prevention?
Contact Central Highlands Water’s Technical Officers on 1800 061 514 for more detailed information.