Our water resource recovery facilities use conventional and advanced technologies to process wastewater, eliminate waste and recover resources. All facilities recycle water, reuse by-products or generate some of the energy they need to do their job. Some do all three. We're committed to reducing the environmental impact of what we do to help mitigate climate change.
Everyone in Greater Sydney should have a reliable, drought-resistant water supply. Recycling and reuse allow us to be less dependent on rainfall to provide water to customers. Recycled water lets us make more water available for residents and businesses to use during drought.
Wastewater is treated to a quality where it can be returned to the environment or recycled, meeting the requirements of our The recycled water we supply to customers meets the high standards of the . .
All 30 of our water resource recovery facilities put wastewater through a multi-step treatment process to remove impurities. It is treated to suit:
There are 5 treatment levels in our recycled water process. Our facilities provide different treatment levels depending on how the water will be used. These include:
We're always looking for ways to reduce our carbon footprint and use alternative and renewable energy sources. Water resource recovery facilities generate different types of renewable energy from their processes as they treat wastewater. They use it to help power their operations.
The different types of renewable energy we recover at our facilities are:
We harness the power of the treated wastewater on its way to a deep ocean outfall. It's captured by our hydroelectric generator at the North Head Water Resource Recovery Facility. North Head is currently the only water resource recovery facility that produces hydroelectricity. It produces up to 58% of its total energy needs from renewable sources, including hydroelectricity. We also produce hydroelectricity in our water network.
Cogeneration is the process of turning waste methane gas (biogas) into electricity and heat. Biogas is naturally created during wastewater treatment. Bacteria break down wastewater sludge in anaerobic (without oxygen or air) digesters. This helps power our water resource recovery facilities.
We're also investigating co-digestion to increase the amount of energy generated at our water resource recovery facilities. Co-digestion is the process of turning food waste into energy by adding it to our anaerobic digesters along with the wastewater sludge. We've trialled co-digestion at Bondi and Cronulla. The next facility to receive food waste will be Liverpool.
We've partnered with Jemena to install a biogas upgrader at Malabar Water Resource Recovery Facility. Excess biogas not used for cogeneration is treated to produce renewable gas, or biomethane, that can be supplied to Jemena's customers via the local gas network.
Biosolids are a nutrient-rich fertiliser converted from the organic solids wastewater solids – or sludge – produced during wastewater treatment. They're a rich source of phosphorus and nitrogen used in agriculture, forestry, composting and land rehabilitation.
These 23 water resource recovery facilities produce biosolids: Bingara Gorge, Bombo, Bondi, Cronulla, Gerringong-Gerroa, Glenfield, Hornsby Heights, Liverpool, Malabar, North Head, Penrith, Picton, Quakers Hill, Richmond, Riverstone, Rouse Hill, Shellharbour, St Marys, Wallacia, Warriewood, West Camden, Winmalee and Wollongong. The remaining water resource recovery facilities transfer wastewater sludge to one of the 23 listed to be processed.
Producing biosolids helps us reduce our environmental footprint by: