The new $3.5 billion Victorian Desalination Project will deliver Australia’s largest desalination plant. It will supply up to 150 GL of water a year to Melbourne, Geelong and, via other connections, South Gippsland and Westernport towns.

The project is being delivered as a public private partnership between the Victorian Government and the AquaSure consortium, comprised of Degrémont, a Suez Environnement company, Thiess, and Macquarie Capital.

The project includes an 84 km underground pipeline to connect the desalination plant to Melbourne and regional water networks. The pipeline will comprise over 6,200 mild-steel cement-lined pipe sections, all 1.9 m in diameter, weighing around 13 t with wall thicknesses of 12.5–20 mm.

Construction of the pipeline is being carried out by the Thiess Degrémont Nacap Pipeline Joint Venture.

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Protecting the pipeline

Savcor Corrosion Engineering Services (CES) division has been contracted by the joint venture to design, supply, install and commission both the temporary and permanent cathodic protection systems for the entire 84 km pipeline.

The temporary cathodic protection (CP) provided to the pipeline utilises sacrificial anodes and the permanent system will be impressed current. Low-potential magnesium sacrificial anodes are being installed to provide temporary cathodic protection during construction stage.

Once the pipeline is completed, impressed current CP systems will be used to provide the ongoing CP. The overall system will incorporate 260 test points which will be used for monitoring the potential levels and the CP systems’ effectiveness. Direct current voltage gradient surveys are also being carried out to detect any defects in the pipeline coating after it has been installed.

The size of the pipeline, its permanent earthing system, numerous insulating flanges and surrounding power infrastructure and other nearby structures are among the challenges that must be overcome to deliver a robust, efficient and effective CP system.

Savcor’s experienced CES team is looking forward to this opportunity and to completing the project on time.