Greywater is household wastewater that comes from:
- bathroom sinks
It doesn’t include water from toilets. This is blackwater which may contain pathogens that spread disease.
Greywater from the kitchen requires a greywater treatment system that is certified to handle kitchen wastewater.
How to reuse greywater
Greywater can be a useful for:
- garden watering, with care. For example, make sure it is low in salt because salt can kill plants. This means you should use low salt shampoo, laundry detergent and soap. Apply greywater below soil surface.
- toilet flushing and clothes washing if properly treated.
- it can contain pathogens that spread disease
- it begins to turn septic and smell if stored for longer than 24 hours untreated.
Do not use greywater as drinking water.
The Australian Government’s YourHome website has advice for reusing greywater, including how to:
- reduce use of cleaning chemicals. Use natural cleaning products if possible
- use low or no sodium laundry detergents, soaps and shampoos
- use a lint filter. Clean and replace as necessary to make sure water can flow through easily.
Don’t dispose of household chemicals down the sink. Contact your local council or water authority for information about chemical collection services.
Treating and recycling greywater
Permanent onsite systems for treating and recycling greywater are regulated by local councils. A council permit is required to construct, install or alter an onsite wastewater management system.
Our Code of practice – Onsite wastewater management (publication 891) has more information about managing domestic wastewater.
Read more about wastewater
Reviewed 19 December 2022