Domestic greywater is wastewater from the bath, shower, basin, laundry tub and washing machine that can be used for lawn and garden irrigation. Some treated greywater can be used for 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 greywater distribution system in your home.
Commercial buildings can also re-use treated greywater.
Untreated greywater
- Manual bucketing: You can collect water from your shower and washing machine by bucket 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. Details about this process can found in Greywater systems.
Treated greywater
Greywater treatment plants collect, clean, store and disinfect greywater and can be installed in sewered and unsewered areas. 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. Details about this process can found in Greywater systems.
Greywater use can be a sustainable and adequate source of water for lawns and gardens during dry spells. When using greywater, it is recommended that the homeowner is vigilant and considers the following suggestions:
- When bucketing or using a flexible hose, spread greywater evenly by emptying in different locations or continuously moving the hose around. This will limit the potential for ponding or run-off. Ponding can become a health risk and cause offensive odours.
- Do not empty or position a flexible hose near property boundaries, stormwater pits or swimming pools.
- Do not use greywater when it is raining or use on ground that is already saturated.
- Avoid human contact with greywater. Use gloves and wash your hands thoroughly when coming into contact with greywater.
- Do not store greywater for any period of time as bacteria will breed quickly and turn greywater septic, in as little as 20 minutes, causing potential odours and health risks.
- Apply greywater to suitable plants and do not use on edible parts of vegetables or fruits.
- When an approved greywater diversion device is installed, ensure the filter on the diversion device and irrigation links are clear and working effectively and ensure the approved greywater system is regularly maintained and installed as per its approved design.
- 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.
Contaminants in greywater can have damaging effects on soils, plants, animals, groundwater and local waterways. Trial greywater use on a small section of the garden to see what effect it has on the soil and the plants before using all over garden.
- To avoid causing long-term damage to your soil and plants, move the hose around regularly rather than leaving it to discharge to the same place.
- Alternate greywater and freshwater.
- Ensure the plants and turf in your garden are greywater tolerant. Identify the sensitivity of plant species (especially native plants) to contaminants found in greywater before using it. Ask your local nursery for more information.
- 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.
- Consider testing your soil regularly for pH, salinity, conductivity and chemical levels. This will tell you the suitability of the soil to absorb greywater, as well as allowing you to monitor the ongoing effects of the greywater on the soil environment and plants.
- Clay soil absorbs water at a slower rate than sandy soil; therefore, it is recommended that greywater is applied slowly to prevent ponding or run-off from the garden surface.
- See your local nursery or hardware store for more information.
- A below ground irrigation system can be designed to suit the soil and other conditions in your yard.
To ensure that the health and wellbeing of our residents and the environment is protected, we investigate any complaints about illegal plumbing installations and misuse of greywater such as:
Fines can be issued for greywater offences.
Greywater issues can be reported by contacting us.