Greywater can replace drinking water for irrigating gardens or lawns and, if treated appropriately, it can be used in toilets and washing machines.
By using greywater for watering gardens and lawns, a household has the potential to save between 50,000 and 100,000 litres of drinking water a year.
Previously, council approval was required for greywater diversion devices to be installed in homes. The NSW Government has changed the rules, and this is no longer required if certain conditions are met.
What is greywater?
Greywater is the wastewater from your shower, bath, spa, hand basins, laundry tub, washing machine, dishwasher and kitchen sink. It doesn't include water from toilets, urinals or bidets. Used appropriately, you can water your garden with greywater and save up to hundreds of litres of fresh water each day.
Benefits of using greywater
Reusing greywater provides a number of benefits including:
- Reducing your potable water consumption
- Reducing the amount of sewage discharged to the ocean or rivers
- Reducing your water bills
- A healthier garden, especially during drought periods.
Disadvantages of using greywater
The disadvantages of greywater reuse may include:
- The potential for pollution and undesirable health and environmental effects if the greywater is not reused correctly
- Initial cost of a greywater system and plumbing requirements
- Ongoing maintenance.
Health and safety
All forms of household wastewater have the potential to be infectious to human health and pollute the environment. However, when managed properly and carefully using appropriate processes wastewater can be converted into a valuable resource that can be reused.
It is very important to follow official guidelines when installing greywater devices and systems to ensure the health and safety of your household and community is protected. More information about how to use greywater safely is outlined in Greywater Fact Sheet 1: Diversion Devices - Dos and Don'ts (PDF 614 KB).
Ways to reuse greywater
There are three ways of reusing greywater:
- Manual bucketing – small quantities of greywater are captured in a bucket for re-use outside on gardens or lawns. No council approval required.
- Diversion – greywater diversion devices redirect greywater for use outside the home on gardens or lawns using sub-surface irrigation. No council approval required under certain conditions. Needs a plumber to install.
- Treatment – greywater treatment systems for reuse inside the home (e.g. toilet flushing, washing machine) as well as outside on gardens or lawns. Council approval is required. Needs a plumber to install.
Guidelines for greywater reuse in households
These guidelines for greywater use in households relate to single, detached households only and do not include premises comprising more than one dwelling.
Read or download these easy to follow fact sheets on greywater reuse for households:
How to purchase greywater devices and treatment systems
Greywater diversion devices can be purchased from some hardware stores or direct from the manufacturer from as little as $200, and require a plumber to install.
NSW Health keeps a register of WaterMark licensed suppliers of domestic greywater diversion devices and accredited greywater treatment systems, you can download these directly from the following links:
Registered environmentally sensitive areas
In areas registered as environmentally sensitive, a council approval is needed to divert greywater. At present, no such areas have been registered.
The best source of information about installing, treating and using greywater devices and treatment systems is your local council or water utility. If you live within the Greater Sydney area, contact Sydney Water.