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Coliban Water – Delivering one of the largest submerged continuous microfiltration plant in the world

In February 2000, Veolia signed a Build Own Operate Transfer (BOOT) contract for 25 years to treat and distribute drinking water to approximately 100,000 residents of the greater Bendigo area.

Coliban Water Aqua


In early 2000, the region was experiencing odour problems in the water supply caused by a build-up of organic material, resulting in overall degradation of the water quality. To avoid this happening again, Coliban Water built three new water treatment plants in Bendigo, Castlemaine and Kyneton as part of the Aqua Project. The cutting-edge microfiltration and ozonation technology at the plants ensures organic material does not enter the region’s water supply system.


In February 2000, Veolia signed a BOOT contract for 25 years to treat and distribute drinking water to approximately 100,000 residents of the greater Bendigo area. The project involved the construction of three advanced water treatment plants. Trunk mains and major storages were also acquired under the contract and owned and operated under the BOOT agreement.
Veolia was responsible for the overall delivery of the BOOT scheme, including network planning, environmental approvals, design, building, operation and maintenance.

The Aqua Project comprises five components:

  • Bendigo Water Treatment Plant (126 ML/d; submerged microfiltration technology CMF-S Ozone and BAC filters)
  • Castlemaine Treatment Plant (18 ML/d; CMF Ozone and BAC filters)
  • Kyneton Treatment Plant (8 ML/d; CMF Ozone and BAC filters)
  • 40 km of trunk pipelines five storage reservoirs totalling 110 ML in capacity.

It involves extensive works across various sites, including 18 major interface points with the existing distribution network.
The water treatment plants use microfiltration (CMF-S and CMF), ozone and Biologically Activated Carbon (BAC) filtration technologies to remove taste and odour compounds and blue-green algae toxins, as well as MF, which guarantees removal of Cryptosporidium and Giardia contamination from unprotected rural catchments. The plants are operated and continuously monitored using a PLC/SCADA control system.

In early 1998, Coliban Water called for registrations of interest for the Aqua 2000 project, a 25 year BOOT project to finance, design, build and operate three water treatment plants and associated infrastructure. US Filter Australia (USFA) was awarded the contract which was signed in November 1999. Following the acquisition of US Filter by Vivendi Environnement (now Veolia), delivery of the project proceeded under the control of Veolia.

The commencement date for the contract was in February 2000 with commercial acceptance in June 2002. The operations and maintenance phase runs until the end of May 2027.

Over the years, Veolia has introduced a variety of new initiatives and projects to continuously improve plant performance, including:
  • Trail of new technology for monitoring of filter turbidity
  • Research and investigation into network nitrification issues and biologically activated carbon filter performance
  • Attendance and presentations at water industry conferences.

In addition, Veolia has continued to manage the development and delivery of the following projects to enable long-term water security to the region to be maintained:
  • Process upgrade project
  • Sludge handling upgrade project
  • Replacement of Bendigo Water Treatment Plant clear water storage liner.


  • At the time of commissioning, the Bendigo Water Treatment Plant was the largest submerged continuous microfiltration plant in the world. Submerged membranes have lower operating costs (primarily reduced energy requirements), compared to conventional membranes.
  • 100% compliance across all performance standards covering water quality, quantity and system performance.
  • Application of new technology and innovation for improved performance and provision of strategic advice in relation to the project.
  • Roll-out of proven maintenance program to minimise unexpected breakdowns and address sudden operational condition changes
  • Continuous monitoring of water quality and systems.


  • Serves a population of 220,000
  • The largest submerged continuous microfiltration plant in the world during the time of its installation.