Backflow is the unintended flow of water from any domestic, industrial or institutional piping system into a drinking water supply system.  It can be caused by a loss of pressure in the drinking water supply main or by the flow from a pressurised system through an unprotected cross connection.

As a property owner or occupier, you need to be aware of the backflow prevention requirements for your business.

Examples of properties with Backflow Hazards:

  • Premises with swimming pools
  • Commercial premises such as factories, chemical plants, cooling towers, grease trap hose out points and laundries
  • Hospital autopsy areas, funeral parlours
  • Irrigation systems with chemical or fertiliser injection
  • Pest control facilities
  • Motorhome effluent dump points, rubbish dumps
  • Caravan parks, secondary school laboratories
  • Food and beverage processing plant

Your requirements are based on the level of risk for your property. See below a general backflow requirements guide of risk level.

General Backflow Prevention Requirements Guide

Abbreviations
RPZD Reduced Pressure Zone Device
DCV Double Check Valve
DDCV Double Detector Check Valve
Dual CV Dual check Valve
HCVB Hose connection Vacuum Breaker
Containment Protection

Containment Protection (backflow prevention at property boundaries):

Site Activity Backflow Hazard Rating Prevention Device
Industrial Commercial Fire storage tank Low Dual check
Fire service with direct connection to the public supply where there is no other connection too alternative or auxiliary supplies, antifreeze, tanks or additives Dual check
Photographic laboratories Hose Connection Vacuum Breaker
Water filtration equipment
Hospitals Medical Veterinary Dental and medical surgeries High Reduced Pressure Zone Device
Dissecting rooms in hospitals and other medical buildings
Mortality equipment used in funeral parlours
Mortuaries, and autopsy areas
Utility room where other than hand basins are installed
Medical Veterinary Operating theatres in hospitals and medical facilities. Medium Double Check Valve
Fixtures Appliances Food preparation or food storage tanks, vats and vessels High Reduced Pressure Zone Device
Sanitary dump points
Fixtures Appliances Hair salons, basins or troughs Low Dual check
Food preparation or food storage tank, vats and vessels Dual check
Hose Connection Vacuum Breaker
Irrigation Fertilisers, herbicides, nematicides, or weedicides injected into an irrigator High Reduced Pressure Zone Device
Drinking nipples and troughs
Irrigation Irrigation systems for farms, animal shelters or sanctuaries Medium Double Check Valve
Commercial irrigation systems
Irrigation systems for other than domestic and residential properties NOT using injection systems.
Outlets and pipework less than 150mm above ground
Irrigation Irrigation systems for domestic and residential properties NOT using injections system.  Outlets and pipework less than 150mm above ground Low Dual Check
Dual check
Hose Connection Vacuum Breaker
Size Activity Backflow Hazard Rating Prevention device
Industrial Commercial Electroplating degreasing descaling stripping pickling dipping etc High Reduced Pressure Zone Device
Tanks vats and vessels
Commercial laundries
Cooling or heating systems with reticulated water
Clean-in-situ sytems (ie, internal chemical cleaning without dismantling)
Dockside facilities
Industrial process water which has been reticulated
Industrial and teaching laboratories
Industrial Secondary school laboratories (including fume cupboard) Medium Double Check Valve
Commercial Fire services other than:
a. Storage tanks
b.Direct connection to public supply where there is no other connection to alternative or auxiliary
Individual Protection
Size Activity Backflow Hazard Rating Prevention Device
Agricultural Antibiotic injectors High Reduced Pressure Zone Device
Horticultural Fertilizers, herbicides, nematicides or weedicides injected into an irrigator
Irrigation
Agricultural Horticultural irrigation Irrigation systems for farms, animal shelters or sanctuaries Medium Double Check Valve
Commercial irrigation systems
Irrigation systems for other than domestic and residential properties NOT using injection systems.
Outlets and pipework less than 150mm above ground
Agricultural horticultural Irrigation systems for domestic and residential properties NOT using injections systems. Low Dual check
Irrigation Outlets and pipework less than 150mm above ground. Dual check Hose Connection Vacuum Breaker
Industrial Commercial Fogging and cleaning spray equipment with chemical injection additives High Reduced Pressure Zone Device
Pan washing apparatus
Chemical dispensers (high toxicity)
Weed and pest spraying;  water cartage tanks
Mixing of chemicals
Portable and mobile tankers
Industrial Commercial Chemical dispensers (low toxicity) Medium Reduced Pressure Zone Device
Aircraft
Coils and jackets in heat exchangers unsealed and toxic environment
Industrial Commercial Coils and jackets in heat exchangers sealed and non-toxic environment Low Dual check
Photographic processing machines non developer mixing Dual check
Hose Connection Vacuum Breaker
Hospitals Medical Equipment used for handling mixing measuring and processing chemical and microbiological substances High Reduced Pressure Zone Device
Veterinary Photographic developers with mixing facilities
Hospital Medical Veterinary Photographic developers Medium Double Check Valve
Water supplying rinse tanks
Dental consoles
Haemodialysis machines
Fixtures Appliances Food preparation or food storage tanks, vats and vessels with clean-in-situ systems High Reduced Pressure Zone Device
Fixtures Appliances Fixtures for food preparation eg, sinks Low Dual check
Laundry troughs Dual check
Fixtures for ablutions eg, baths, bidets, showers and basins Hose Connection Vacuum Breaker
Hair salons basins and troughs
Drink dispensing equipment vending or coffee machines
Food preparation or food storage tanks, vats and vessels
Hose attachment outlets Areas in factories using or processing toxic chemicals High Reduced Pressure Zone Device
Sewerage treatment or pumping plants
Caravan parks (soil and waste dump points)
Hose attachment outlets Flexible connections of domestic fixtures Low Dual check
External hose taps Dual check
Hoses located in an area provided with zone protection Hose Connection Vacuum Breaker
Laboratory outlets
Hose attachment outlets Flexible connections over domestic fixtures Variable As required
External hose taps
Hose located in an area provided with zone protection
Laboratory outlets
Hose bib applications Steam boilers and cooling towers permanently attached to the water supply High Reduced Pressure Zone Device
Hose bib applications Steam calorifier Medium Double Check Valve
Water treatment systems Demineralising equipment using ion exchange resins with alkali regeneration High Reduced Pressure Zone Device
Plants with auxiliary non potable water supplies
Water treatment systems Chlorinators Medium Double Check Valve
Water treatment systems Potable water in reclaimed water plants Low Dual check
In-line water softeners and filters Dual check
Hose Connection Vacuum Breaker
NOTE: Please check applicable state regulations for backflow prevention requirements and Australian standards as these are a guide only. Pressure vacuum breakers are liable to discharge to the atmosphere during normal operating and may not be suitable for use in areas where containment of this discharge is impractical.

To speak with your local Backflow Prevention specialist about your backflow prevention requirements, find and contact them here.