5 West Nutrient Removal Plant Project

The Western Treatment Plant (WTP) sustainably treats almost half of Melbourne’s sewage daily. We’ve been constructing the 5 West Nutrient Removal Plant (NRP) to ensure a safe sewerage service for local homes and businesses now and into the future. 

Why this project is important 

This critical upgrade involves constructing a new Nutrient Removal Plant (NRP) capable of processing an additional 150 million litres of wastewater per day. The new plant will:  

• address future growth and improve overall plant efficiency.
• replace 55E Activated Sludge Plant which was built in 2001.
• enhance safety for the operations and maintenance teams to avoid high risk activities, such as diving and working over water from boats.
• provide the opportunity to implement lower cost, more energy efficient treatment technology, such as short cut nitrogen removal process.

What we are doing

The scope of works includes:  

• construction of five combined bioreactor-clarifier tanks with associated feed, waste activated sludge and effluent discharge pipeline connection.  
• installation of interconnecting pipework between pond systems.  
• building ancillary buildings and pump stations.  
• fitting process mechanical equipment.  
• high and low voltage electrical works.  
• installation and calibration of sensors, transmitters, and analysers for control automation and process monitoring.  
• commissioning of the plant infrastructure.  

Project benefits 

The key benefits of this innovative project include:  

• maintaining compliance of total nitrogen load discharged to Port Philip Bay as there has been increasing load growth in the WTP catchment.     
• protecting Port Philip Bay’s biodiversity by reducing the severity of algal blooms.  
• supporting the local community by securing consistency in the recycled water supply delivered to local Werribee growers.