Domestic greywater is wastewater from the bath, shower, basin, laundry tub and washing machine that can be used for lawn and garden irrigation, toilet flushing, cold water in the laundry and washing machine and the washing of paths, external walls and vehicles.
Grey water does NOT include toilet water or greywater generated from a kitchen in a sewered area due to the high levels of grease, fats, oils and food particles which can clog the plumbing in your home.
In unsewered areas kitchen water should be first put through a grease trap before it is diverted to the greywater treatment plant.
Commercial buildings can also re-use greywater.
Ways to use untreated greywater
- Manual bucketing - You can collect water from your shower and washing machine by bucket (you can't collect wastewater from the kitchen) and empty the water onto your gardens and lawn.
- Connect a flexible hose to a washing machine outlet - Connect a greywater hose to your washing machine outlet and place the other end of the hose outside to water the lawn and garden. By placing the hose so it runs downhill you'll ensure the washing machine can pump the water.
- Greywater diversion device - Greywater from the laundry, shower, bath and wash basin can pass through the pipes to a diversion device. The greywater flows through a filter in the device to blocks solids and can then be used to irrigate your lawn and garden.
- Manual and automatic diversion devices are available.
- Before purchasing a diversion device ensure it meets Australian standards.
- A licensed plumber must install the diversion system and a plumbing approval will be required. Read more about this here.
Ways to use treated greywater
Greywater treatment plants collect, clean, store and disinfect greywater. The end product can be used for:
- lawn and garden irrigation.
- toilet flushing.
- washing of external paths, walls and vehicles.
- laundry and washing machine use (cold water source only).
A licensed plumber must install the greywater system and a plumbing approval will be required. Read more about this here.
Greywater diversion devices and treatment systems
The installation and operation of a greywater diversion device or treatment plant and the accompanying irrigation system needs to be implemented by a plumber and requires our approval (see approval process information below). Plumbers can work with you, the homeowner, to plan a greywater facility and irrigation system that will work with your land.
Once a system is installed it is the owner's or occupier's responsibility to ensure the system is maintained regularly, by cleaning or replacing filter and organising servicing.
Greywater diversion device
A greywater diversion device consists of a filter that removes hair, lint and other solids. The device is fitted with a switch that diverts greywater through to a subsurface or surface irrigation system.
Greywater treatment plants
A greywater treatment plant collects, stores, treats and disinfects greywater and can be installed in sewered and unsewered areas.
Approval process for greywater diversion and treatment systems
Before installing either a greywater diversion device or greywater treatment system you'll need to apply for approval. Read more about this...
Approval is not required for manual bucketing or connection of a flexible hose to a washing machine outlet.
Tips for greywater use
- Alternate greywater and freshwater.
- Ensure the plants and turf in your garden are greywater tolerant.
- Choose laundry detergents designed for greywater re-use. They will be low in phosphorus, sodium and nitrogen.
- Only use greywater in your garden when it needs watering as over watering may damage plants and soil structure.
- Use gloves and wash your hands thoroughly when coming into contact with greywater.
- Prevent run-off into neighbouring properties.
- A below ground irrigation system can be designed to suit the soil and other conditions in your yard.
Greywater should be used responsibly. Keep the following list in mind when using greywater.
- Don't store untreated greywater - Greywater stored for more than 24 hours may turn septic, give off offensive odours, breed mosquitoes and provide conditions for the growth of micro-organisms. If the immediate use of greywater is not practical it should be diverted to the sewerage system.
- Don't allow children, pets or human contact to occur where greywater has been used.
- Don't use greywater that has been used to wash soiled clothes e.g. nappies or labourer work uniforms.
- Keep greywater from flowing into stormwater drains, polluting ground water and watercourses.
- Don't allow greywater to pond as it may become a health risk and cause offensive odours.
- Don't use greywater on edible plants.
To ensure that the health and well being of our residents and the environment is protected, we investigate any complaints about illegal plumbing installations and misuse of greywater such as:
- the installation of a greywater diversion device or treatment plant without our prior approval.
- the installation of a greywater diversion device or treatment plant without a current plumbers and drainers licence.
- the installation of a non-approved greywater diversion device or treatment plant.
- greywater ponding, run-off causing a danger or health risk to anyone and offensive odours from greywater.
- kitchen waste being used as greywater.
Fines can be issued for greywater offences.