Melbourne Water completes major upgrade to sewage treatment with world-leading innovation
Melbourne Water is proud to announce the completion of the 5 West Nutrient Removal Plant (5W NRP), a groundbreaking upgrade to the Western Treatment Plant. This world-leading innovation will boost the city’s sewage treatment capacity while also reducing energy requirements and improving water quality.
The 5W NRP is designed to achieve one of the world's first full-scale Shortcut Nitrogen Removal processes. This advanced technology, which reduces energy use due to less aeration demand and carbon requirements compared to traditional treatment methods, is a major step forward in sustainable sewage treatment.
At the core of the plant are five colossal circular tanks, each towering as high as a two-storey building and wider than a football field. These tanks are capable of treating up to 150 million litres of sewage per day. Together, they replace the 55E Activated Sludge Plant built in 2001, enabling safer, more efficient and environmentally friendly sewage treatment.
"This marks a significant milestone for Melbourne Water and the broader community, " said Managing Director, Dr Nerina Di Lorenzo. “We are committed to delivering sustainable, climate-smart infrastructure which supports our city today and into the future."
The new facility, built in collaboration with BMD and Jacobs, cost approximately $330 million. The completion of the 5W NRP marks the final stage of a three-part program to upgrade sewage processing. This program, which began in 2016, responds to Melbourne’s population growth, and will improve the efficiency of the Western Treatment Plant.
The 5W NRP delivers multiple benefits for both the environment and the community. It helps reduce Melbourne Water’s nitrogen loads to Port Phillip Bay, therefore playing a critical role in protecting the Bay’s environmental values. The facility also provides source water for the recycled water that supports Werribee's agricultural sector with irrigation.
"This facility is a powerful example of how innovation in essential services can deliver lasting environmental and economic value, turning what was once considered waste into valuable resources."
In addition to its environmental credentials, the new plant significantly enhances worker safety by replacing high-risk manual operations with modern, automated technology.
Melbourne Water remains committed to investing in future-ready infrastructure that safeguards public health, supports our city’s growth, and strengthens the resilience of our natural environment.
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