Wastewater systems

How we process water when you're done with it

Wastewater, also known as sewage, is the used water that goes down sinks, toilets and drains. We treat it so it's safe to recycle and reuse, and we recover valuable by-products. Then we return safe, treated wastewater to the environment.

Find your local water resource recovery facility on our wastewater systems map.

Where your wastewater goes

When wastewater leaves the pipes on your property, it connects with one of our 24 wastewater systems throughout Sydney, the Illawarra and the Blue Mountains. Our systems provide wastewater services to more than 5.2 million people.

The NSW Environment Protection Authority (EPA) sets standards for the performance of our wastewater pipes and water resource recovery facilities to protect public health and the environment. We have environment protection licences in place that we monitor. We treat our wastewater to meet EPA requirements to protect the environment.

Our wastewater systems consist of:

  • about 27,000 kilometres of wastewater pipes
  • about 30 water resource recovery facilities, which treat over 1.3 billion litres of wastewater every day
  • 695 wastewater pumping stations.

Cronulla Water Resource Recovery Facility

Sydney Water owns and operates most wastewater systems in Greater Sydney. However, customers are responsible for maintaining wastewater pipes to where they connect with our systems. Find out how to deal with wastewater blockages.

Precautions when working with wastewater
If you work in and around untreated wastewater, refer to our Chemwatch safety data sheet for substances wastewater may contain and how to minimise risk.

How we treat wastewater and recover resources

Water resource recovery facilities give new life to wastewater through recycling, reusing by-products or generating some of the energy the facilities need to do their job. We're committed to reducing the environmental impact of what we do to help mitigate climate change.

We're building new facilities as our population grows. Get project updates at Sydney Water Talk.

Sewer mining

Some non-residential customers produce their own recycled water through sewer mining. They extract wastewater from their local wastewater system and treat it on-site using a small treatment plant. They can use the recycled water in various ways:

  • to flush toilets in commercial buildings and at industrial sites
  • in cooling towers
  • to irrigate sports fields, parks and golf courses.

Find out more about sewer mining and other ways we're producing recycled water.

Why we monitor treated wastewater

Wastewater from homes and businesses contains nutrients, organic matter, bacteria, and cleaning products like shampoo and detergents. Commercial and industrial customers produce trade waste. If wastewater was discharged without being treated, it would harm the environment.

Monitoring and reports

We routinely check what's in treated wastewater and report it in our EPA pollution monitoring data reports. We also publish yearly reports on our detailed long-term aquatic monitoring programs.

You can learn more about the safety of Greater Sydney's harbour and ocean beaches from the NSW Government Beachwatch program. RiverWatch® is our recreational monitoring and reporting program for rivers, creeks, lakes and harbour inlets. It monitors water quality at Urban Plunge® swim sites.

Controlling wet weather overflows

The Northside Storage Tunnel stores excess wastewater and stormwater that may overflow into Sydney Harbour. By preventing untreated overflows, we can help protect public health, recreational activity and aquatic ecosystems in the catchment.

Stay safe if you see a wastewater overflow
Please avoid wastewater overflows. If you see a wastewater overflow, report it. Call us on 13 20 90 24/7.