The Western Treatment Plant (WTP) processes 55% of Melbourne’s sewerage, approximately 485 ML/day, and the effluent water is treated via both the 25W and 55E lagoons before being discharged to Port Phillip Bay.


WTP was looking to improve assets and infrastructure to increase reliability, safety, and environmental concerns. Ageing electrical infrastructure poses a reliability risk to the Lagoon Aeration System, precisely six existing HV kiosk transformer substations. An arc flash risk has also been identified for these ageing assets. Increased electrical assets’ reliability mitigates the risk of an EPA license break by aerators being offline due to equipment failure.


Middleton Group prepared the detailed design for the HV & LV electrical, control, communications components of the WTP 25W Pond 1 HV Kiosk Substation Upgrade. Developed protection settings for LV and HV components, Kiosk substation specification and electrical layouts, and cable specifications for substation connections.


The impact of our work resulted in Melbourne Water being able to upgrade the necessary assets swiftly and therefore significantly increasing reliability and safety of their processes due to the detailed plan provided to them by Middleton Group.

Project team

Adam Loucas

Senior Power Engineer