Water recycling

All water is precious

Recycling water isn't new. Nature recycles water over and over again. We use technology to speed this process up. Find out how it’s done, how recycled water can be used and where we do it in Greater Sydney.

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. It's important we use, reuse and conserve it wisely.

How is recycled water made?

All water can be recycled, but it most often comes from wastewaterstormwater or greywater. We clean the water so that it's safe to be reused. You can learn more about How we turn wastewater into recycled water.

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
  • Environmental flow

Recycled water treatment processes

Flow chart

Why should we recycle and reuse water?

Reducing and reusing 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 reuse water.

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

Recycled water can be used to irrigate sports fields.

Fire fighters can use recycled water instead of drinking water.

How can you tell if you have recycled water?

Recycled water comes to you through purple pipes that are completely separate from the drinking water system. The recycled water system has separate taps for safety. 

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, which should have a ‘do not drink’ warning sign nearby
  • recycled water charges on your water bill.

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

Recycled water taps are purple.

How can you use recycled water?

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).

We clean the water to a high standard so it can be safely used again, but it's not treated enough for drinking.

Recycled water from 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.

Learn more about using recycled water.

Did you know?
Many cities around the world use recycled water as part of their drinking water supply. Some places you might like to learn more about are PerthSan Diego and Singapore.

Where is water recycled in Sydney?

We have 14 water resource recovery facilities that recycle water. Find out more about our recycled water network.

We run 4 of the largest water recycling projects in Australia.

Rouse Hill

The Rouse Hill Water Resource Recovery Facility 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.

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

The St Marys Advanced Water Treatment Plant produces recycled water for the Hawkesbury-Nepean River.

St Marys

There are 2 sites at St Marys that work together to make high-quality recycled water for 2 different purposes.

The St Marys Water Resource Recovery Facility produces recycled water for irrigating the local golf course.

Right next door, the St Marys Advanced Water Treatment 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.


The Penrith Water Resource Recovery Facility makes recycled water that's used to water sporting fields in Penrith.

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

Local sports fields are watered with recycled water at Penrith.

BlueScope Steel uses recycled water to cool equipment.


Wollongong Water Resource Recovery Facility makes 2 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 facility 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 and reduce dust.

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.

Make a membrane model

Try this activity to make your very own reverse osmosis module. It's easy to do!

Teacher resources

Does your school have purple taps? (7.2MB) – try this classroom activity to find out if your school has recycled water

Recycled water lesson plan – investigate recycled water

How do we clean recycled water? –  worksheet

Make a membrane model (350KB) – try this activity to make a membrane model and discover how they work

Make a membrane model lesson plan (185KB) – Stage 6 Chemistry

Glossary – definitions of keywords and industry terms


The used water that goes down toilets, sinks and drains and into the sewerage system. Also known as sewage. About 99% of it is water.