Greywater  is wastewater from non-toilet plumbing fixtures such as showers, basins and taps. Depending on its use, greywater can require less treatment than blackwater and generally contains fewer pathogens.

Treated greywater can be re-used indoors for toilet flushing and clothes washing, both of which are significant consumers of water. Greywater can also be used for garden watering. The average Australian home produces about 113 litres of greywater per day. 

Wastewater re-use opportunities vary according to where you live. Urban households typically have a connection to a centralised, or reticulated, sewage system, whereas rural households manage their wastewater on-site. The regulations concerning the treatment and re-use of wastewater vary according to your location. You need to check with your local council or state health authority for advice on the regulations in your area. In some States it is illegal to re-use wastewater in urban areas. Wastewater can be used to flush toilets, water gardens and even to wash clothes.

By using wastewater as a resource rather than a waste product you can:

• Reduce water bills Use less water resources
  
• Cut down the amount of pollution going into our waterways
  
• Help save money on new infrastructure for water provision and wastewater treatment.
  
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Wastewater re-use decreases effluent volumes, reducing the stress on existing centralised wastewater disposal systems, which will work better and last longer. There are two types of wastewater created in a home, each of which can be treated and used in various ways.

An example of a Grey Water Diversion Unit is shown below.