Water recycling

What is recycled water?

Recycled water is water that's been used before. It's a valuable resource that can be used for many different things.

We take wastewater and clean it to a high standard so it can be returned to homes and businesses and safely used again.

Watering the garden with a hose fitted with a trigger nozzle

Recycled water can be used to water gardens.

Recycled water treatment processes

Recycled water treatment processes. Select the image to see a larger version.

Recycled water comes from wastewater. We clean the wastewater so that it's safe to be used for other things.

Recycled water has been through several wastewater treatment steps. The types of treatment steps used depends on how the recycled water will be used.

We treat recycled water to meet the Australian Guidelines for Water Recycling 2006. To make sure it's safe to use, we monitor and test the water regularly.
Treatment level Recycled water uses
  • Irrigation
  • Irrigation
  • Industry, like dust suppression
  • Watering gardens
  • Flushing toilets
  • Specialised industrial processes, like steel manufacturing

Recycling and re-using water is a great way to save drinking water and help care for the environment.

Saving drinking water by recycling means we have extra water available in case of drought - and for a growing population.

We don't need to use drinking water to flush toilets or water sports fields. Recycled water can do the job safely and just as well.

Sprinklers on a sports field.

Recycled water can be used to irrigate sports fields.


Some activities, like fighting fires, use high volumes of water very quickly. We can conserve drinking water and use recycled water instead.

A fire fighter putting out a fire

Fire fighters can use recycled water instead of drinking water.

Purple recycled water tap next to a drinking water tap.

Recycled water taps are purple.

Recycled water comes to you through purple pipes that are completely separate from the drinking water system.

If your home or school has recycled water you should be able to see:

  • a second water meter that is purple
  • a purple garden tap. It should have this sign near it: 'Recycled water - do not drink.'  
  • recycled water charges on your water bill.

Try the Does your school have purple taps? classroom activity.

Recycled water is great for:

  • watering lawns and gardens, including fruit and vegetable plants
  • flushing toilets
  • washing cars
  • filling ornamental ponds
  • fighting fires
  • washing laundry in a washing machine (you need the right plumbing for this).
Lady washing a car on the lawn

If your house has recycled water, you can use it to wash your car.

Recycled water can't be used for:

  • drinking or cooking
  • bathing
  • filling swimming pools and playing under sprinklers
  • cleaning inside the house
  • filling evaporative coolers.

The recycled water system has separate taps for safety. Look out for purple water pipes and taps, and signs near taps saying 'Warning - not for drinking'. 

Learn more about using recycled water.

We have 14 water recycling plants. Find out more about our recycled water network.

We run three of the largest water recycling projects in Australia.

Rouse Hill

The Rouse Hill Water Recycling Plant is our largest residential recycling project.

It provides recycled water to about 32,000 homes and businesses in the Rouse Hill area for things like watering gardens and flushing toilets.

Lady watering a garden with a hose in front of a house

People living in Rouse Hill can use recycled water to water their gardens.

St Marys

There are two water recycling plants at St Marys that work together to make high quality recycled water for two different purposes.

The St Marys Water Recycling Plant produces recycled water for irrigating the local golf course.

Right next door, the St Marys Advanced Water Recycling Plant is part of Sydney’s largest water recycling project. It produces up to 18 billion litres of very high quality water a year for the Hawkesbury-Nepean River system.

Water coming out of large metal pipes.

The St Marys advanced plant produces recycled water for the Hawkesbury-Nepean River.


The Penrith Water Recycling Plant makes recycled water that's used to water sporting fields in Penrith.

Some of the water is also sent to St Marys Advanced Water Recycling Plant to produce very high quality water for the Hawkesbury-Nepean River system.


Wollongong Water Recycling Plant makes two different types of recycled water.

It makes some recycled water that is suitable to irrigate the local golf course and sporting fields, and for dust suppression at the nearby coal terminal.

The plant also uses advanced membrane technology to provide high quality recycled water to BlueScope Steel at Port Kembla.

BlueScope Steel uses about 20 million litres of recycled water every day to:

  • make iron and steel
  • cool the plant and equipment
  • reduce dust.  

Bluescope steel using recycled water.

BlueScope Steel uses recycled water to cool equipment.

Want to visit a water recycling plant?
We offer excursions and technical tours to schools, universities and community groups. Find out more about excursion requests.

Other water recycling projects

We aren't the only organisation recycling water.

There are lots of other water recycling projects around Australia and the world. The Australian Water Association website has more information about water recycling.

Other types of water, like stormwater and greywater, can be recycled too.

Stormwater recycling

Stormwater is rainwater that runs off hard surfaces like roofs and roads and is carried away by stormwater drains flowing into local waterways.

We can capture stormwater, treat it and use it for things like watering gardens, flushing toilets and, in some cases, in washing machines.

Greywater recycling

Greywater is the wastewater from washing machines, dishwashers, showers, baths and basins. It does not include wastewater from toilets or kitchens.

Greywater can be captured and used to water gardens.

Learn more about greywater re-use.