Reusing greywater

You can improve the amount of water you save by using greywater as an alternate source for garden and lawn irrigation or, if treated appropriately, for toilet flushing and washing machines. Substituting greywater not only saves our precious drinking water supplies, but also reduces the amount of wastewater discharged to the environment.

What is greywater?

Greywater is household wastewater collected from baths, spas, showers, hand basins, washing machine rinse cycles or laundry tubs. The safest, cleanest greywater comes from the shower, bath or washing machine. Greywater does not include water from flushing toilets, urinals, bidets, dishwashers or kitchen sinks.

Based on current NSW Guidelines for greywater reuse, there are three ways greywater can be used for domestic purposes:

  • Manual bucketing - capturing small quantities in a bucket for outside use on gardens or lawns. No Council approval is required.
  • Diversion - permanent greywater diversion devices redirect for outside use on gardens or lawns using sub-surface irrigation. These must be installed by a plumber. No Council approval is required under certain circumstances
  • Treatment - permanent treatment systems treat the greywater to ensure it is safe for reuse inside the home eg flushing toilets, washing machines, as well as outside on gardens and lawns. These must be installed by a plumber and Council approval is required.

Protecting your health

Greywater contains a range of contaminants that could cause health problems and damage the environment if it is not appropriately treated and distributed. Contaminants in your greywater may be either chemical (from detergents and cleaners) or microbial (such as bacteria from your skin and clothes). To protect public and environmental health, greywater should not be allowed to run off your property. The Australian Standard also requires that the outlet of a greywater diversion device is marked ‘Warning do not drink’ and all irrigation pipes be coloured purple.