Under the New Zealand Building Code, water from the water network must not be able to return – or ‘backflow’ – to the system.
Backflow is dangerous when there is a cross-connection between a drinking water supply and a source of contamination or pollution. For example, a garden hose being left on in a bucket that has chemicals in it.
There are cases where the public water supply has been contaminated with dangerous chemicals and other pollutants, causing illness. Simply because people weren’t aware of backflow.
How you can stop backflow
At home, you can reduce the risk of backflow by fitting an inexpensive hose tap vacuum breaker on outdoor hose taps. Available from your local plumber.
Commercial prevention measures
Commercial buildings with potential hazards must have adequate backflow prevention.
- hospitals and medical centres
- agricultural and horticultural operations
- points where portable water tankers are filled
- premises with boilers and cooling towers
- hairdressers and barbers
- some food preparation premises
If you’re not sure of the risks at your premises or business, call our Water Technical Officer on 06 356 8199.
Best practice: Backflow protection for hairdressing salons(PDF, 166KB)