Greywater is household wastewater that comes from:

  • baths 
  • showers 
  • bathroom sinks  
  • laundries.  

It doesn’t include water from toilets, as this is blackwater that goes through sewerage systems. It also doesn’t include water used in kitchens and dishwashers. This water can contain viruses or bacteria that spread disease.  

How to reuse greywater

Greywater can be a water resource during drought and water restrictions. It can be useful for:  

  • garden watering, with precautions. 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.  

You must treat and disinfect greywater before storage and reuse because: 

  • it can contain large numbers of 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.

Permanent systems for treating and recycling greywater require council permits. To find an approved onsite wastewater system, see current certificate holders.  

Our Code of practice – Onsite wastewater management (publication 891) has more information about managing wastewater.

Read more about wastewater

About wastewater

How to manage your own septic system

Onsite wastewater treatment systems with valid certificates

Regulatory framework and approval process for onsite wastewater treatment systems

Wastewater guidance for industry

Reviewed 16 September 2020