Featured artist: Shannon Crees

Reuse wastewater (greywater)

Featured artist: Shannon Crees
You are here:


What is greywater?

Garden irrigated with greywaterGreywater 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.

Greywater can be used instead of drinking water to irrigate gardens or lawns and, if treated appropriately, it can be used in toilets and washing machines. By using greywater for irrigation alone, a household can save between 50,000 and 100,000 litres of drinking water a year.

What are the benefits of using greywater?

  • Reduces your potable water (or drinking water) consumption.
  • Reduces the amount of sewage discharged into our water ways and oceans. 
  • Reduces your water bills.
  • Ensures your garden gets water during drought.

Three ways to reuse greywater:

  1. Manual bucketing – small quantities of greywater are captured in a bucket for re-use outside on gardens or lawns. No council approval required. 
  2. Diversion – a greywater diversion device simply redirects greywater without storage or treatment. Flow is activated through a switch which sends greywater back to the sewer during wet weather. Water is only suitable for use outside the home on gardens or lawns using sub-surface irrigation. The system must be installed by a plumber. No council approval required if all conditions are met.
  3. Treatment – a domestic greywater treatment system collects, stores and treats greywater to a high standard. Water is potentially suitable for use in your toilet or washing machine, as well as outside on gardens or lawns. Council approval is required and the system must be installed by a plumber. Council approval is only able to be given for NSW Health accredited greywater treatment systems.

What things do I need to consider?

Example of a simple greywater treatment system suitable for domestic housing (copyright www.greywater.com)

Example of a simple greywater treatment system suitable for domestic housing
(© www.greywater.com)

Council recommends you consider all water efficiency measures and rainwater harvesting options before investigating greywater reuse. It may be that you can adequately provide for your family's water needs without the use of greywater, particularly if your property is small. In order to assess your family's current water use and how much greywater your home actually produces it is helpful to conduct a water audit.

Reusing greywater sensibly can be costly as systems must be designed, installed and maintained in a manner which protects public health and is ecologically sustainable. Such costs may be better directed, in the first instance, to items such as water conservation devices and rainwater tanks which have less environmental and public health impacts.

All forms of household wastewater have the potential to be infectious to human health and pollute our waterways and soils. The Department of Energy Utilities and Sustainability has investigated the risks of greywater reuse and has developed the NSW Guidelines for Greywater Reuse in Sewered, Single Household Residential Premises. Follow these guidelines when installing and using a greywater system to protect the health of your family, community and the environment. All greywater systems require ongoing monitoring and maintenance.

Most original soils in the Marrickville are clay based which means that water is absorbed quite slowly. As chemicals in greywater often decrease the rate of absorption it is important  that Marrickville residents do not apply greywater too quickly as it may run off the garden surface and enter stormwater drains.

Contact Council's Water and Catchments Coordinator or phone 9335 2104 for more information.


Related sites