What is greywater?

Greywater is the name given to wastewater from household appliances such as showers, baths, basins, sinks, washing machines and dishwashers. It does not include wastewater from toilets (this is known as blackwater).

Using greywater can carry a number of potential health and environmental risks. Care must be taken to ensure that greywater is used in a safe and controlled manner. Using greywater correctly can help you conserve water. 

How can I use greywater?

Household greywater can be used to water your garden and/or for toilet flushing. Using treated greywater for toilet flushing can potentially reduce your domestic water consumption by up to 20 per cent. However, untreated greywater is not suitable for toilet flushing.

A trial on greywater use for toilet flushing and garden irrigation, carried out on four houses in Melbourne by Victoria University, resulted in water savings of tens of thousands of litres per year, for each household.

Am I allowed to use greywater?

To find out if you are allowed to use greywater, and for qualified professional advice, contact authorities, such as your local council, or the Environment Protection Authority.

In most cases, untreated greywater can be diverted for immediate use, as long as there is no adverse impact on public health or the environment.