Water recycling

What is recycled water?

Recycled water is water that's been used before.
Did you know that all the water on Earth is all that we have? It's continually moving through the natural water cycle.

We have many water sources to make sure we have resilient and liveable cities as our population grows and our climate changes.

Recycled water is a valuable resource and it's important we use, re-use and conserve it wisely.

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.

All water can be recycled, but it most often comes from wastewater , stormwater or greywater. We clean the water so that it's safe to be re-used.

Recycled water has been through several treatment steps. The number and treatment steps used depends on how the 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

Reducing and re-using water is a great way to make sure we have enough, and help care for the environment.

Recycling water means we have another water source to rely on 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. We can make cooler, greener and more liveable cities when we re-use water.

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.

In greater Sydney we clean the water to a high standard to it can be returned to homes and businesses and safely used again, but it's not treated enough for drinking.

For homes, 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.

Did you know?
There are many cities around the world that use recycled water as part of their drinking water supply. Some places you might like to learn more about are Perth, San Diego and Singapore.

Recycled water that is supplied in a purple tap or pipe in greater Sydney 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 four 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 high schools, universities and community groups. Find out more about excursion requests.

Other water recycling projects

We aren't the only organisation recycling water. Urban water management is a big job and we all have a role to play.

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