A circular economy aims to eliminate waste, reuse or recycle it. The purpose is to restore and regenerate resources, compared to a linear economy of taking resources, using them and disposing of the waste.
A key part of our corporate strategy is to eliminate waste, or recycle and reuse the by-products of our activities. We're investigating innovative technologies and designing our systems to maximise recycling and reuse water and energy. We're working to restore and regenerate the natural environment and reduce our carbon footprint.
The used water and solids from wastewater treatment contain valuable resources we can recover and reuse, to minimise our impact on the environment.
Along with recycling, we're committed to protecting and maintaining the environment through renewable energy and efficiency initiatives to reduce our carbon footprint. Our recycling program is diverse. It includes:
We're always looking for more ways to reuse and recycle our resources, working with other agencies, businesses and research partners to develop innovative recycling solutions.
Nature is the world’s biggest water recycler. All water on earth is used and reused in an endless cycle – the natural water cycle. We use technology to speed up this natural process, so we can reuse this precious resource without relying entirely on rainfall. It also reduces the impact of waste on the environment.
We've been recycling water since the 1960s. We started with small irrigation projects and now produce billions of litres of recycled water each year. We provide recycled water for:
Recycled water is wastewater that's been used in homes and businesses and treated so it's safe to reuse. We put it through a multi-step treatment process to remove impurities, so the purified recycled water can be used in many ways.
Recycled water can be produced using:
Recycling and reusing water means we don’t need to depend as much on rainfall and reduces the amount of waste going to the environment.
Recycling also ensures we have extra water available, in case of drought, to supply Greater Sydney's growing population.
Read more about producing recycled water.
How much we treat recycled water determines what it can be used for. We treat it to a high standard, suitable for its intended purpose. We don't currently supply recycled water for drinking and so we don't treat it to drinking water standards.
We monitor closely to ensure it meets strict recycled water quality guidelines, so it's safe to use:
Recycled water isn’t the only thing we produce at our treatment plants. We also produce biosolids – the nutrient-rich by-product of the wastewater treatment processes.
Biosolids are a rich source of phosphorus and nitrogen and can be used in agriculture, land rehabilitation, horticultural processes and mining.
Each year, we produce around 180,000 wet tonnes of biosolids from Sydney's wastewater. The strictly regulated process allows 100% beneficial reuse in agriculture. This results in greater crop yield for Australian farmers and improved environmental outcomes.
The NSW Environment Protection Authority (EPA) and NSW Health advise that biosolids are safe if produced and used in line with their guidelines. We meet all the requirements in the guidelines.
To learn more about the biosolids guidelines, visit
When solids are separated from wastewater during the wastewater treatment process, they go through biological treatment. This reduces pathogens, odours and particles that attract insects and vermin.
All biosolids we produce are tested at laboratories to ensure they comply with regulations to protect human health and the environment. Our $25 million biosolids program uses the latest technology and treatment processes. This ensures we can:
Find out more about
Examples of biosolids use
Benefits of biosolids
Nutrients from biosolids are released slowly during plant growth. This increases crop production, provides superior water-holding properties and replaces nutrients removed from soil by harvesting.
Biosolids are mixed with other organic materials such as green waste, shredded timber and sawdust and allowed to compost naturally. This material is usually mixed into the soil to improve soil structure and help hold water.
Biosolids are used to restore mine sites and degraded agricultural land.
We're committed to protecting and maintaining the environment through renewable energy and efficiency initiatives. Renewable energy comes from natural resources that never run out.
Our Renewable Energy Generation Program is part of our pledge to reduce greenhouse gas emissions.
Our program includes producing electricity:
We use much of the renewable energy we generate to power our wastewater treatment and water recycling plants.
Find out more about energy management and climate change.
Our goal is to reduce waste through recycling and reuse and to encourage our suppliers to minimise waste. We avoid generating waste wherever possible.
Our waste procedure is consistent with the NSW Government's Waste Reduction and Purchasing Policy (WRAPP). We publish a yearly statement that outlines how we apply our waste reduction strategies. It includes details about: