The Warrnambool Sewage Treatment Plant upgrade is nearly finished

The upgrade of the Warrnambool Sewage Treatment Plant is nearing completion, with all major structures now in place. Subject to commissioning works, the plant is scheduled to come online in late 2025.

A new odour control facility will soon be connected, and we’ll also install an aeration diffuser system linked to the new treatment tanks. Installation of the ultra-violet (UV) disinfection system continues, which will add an extra layer of protection for the environment and human health. We also plan to install UV disinfection on the existing treatment tanks in early 2026.

Work to reinstate the site entry road and landscape the surrounding dune will begin later this year.

Commissioning works

Once the mechanical and electrical fit-out is complete, we’ll start commissioning the new system, aiming to bring it online in late 2025.

We’ve received the green light from the Environment Protection Authority (EPA) to move forward with commissioning. This process will take several months and involves:

• Pre-commissioning checks and dry system testing to ensure all mechanical and electrical components are installed correctly.
• Circulating clean water through the system to make sure everything works as it should.
• Diverting sewage to the new plant and setting up the treatment process, which includes connecting new sewer access points.

Preliminary performance testing of the new system will take up to a month. After that, we’ll continue to test and monitor the system for several months before it officially comes online.

At the end of commissioning, we’ll submit a final report to the EPA for their approval.

Dune revegetation

Work continues to ensure our revegetation design for the dune surrounding the site reflects the needs of the environment, user groups and the wider community.

Recently, we met with key stakeholders to inspect the site and discuss a draft landscape concept plan. Most stakeholders are supportive of the plan, but we’re still waiting on full approval before we can finalise it.

Once the plan is officially approved then we’ll be able proceed with the plant zone layout.

Effluent Management Strategy

In parallel with the upgrade project, we’re developing an Effluent Management Strategy (EMS) to investigate alternative methods for further treating sewage and trade waste, and for the disposal of treated effluent over the next 50 years.

As part of this work, we recently established a community panel that comprised 12 independently selected members including interested people and representatives from local stakeholders from an environment group, industry and local organisations.

Over four sessions, from February to April, the panel participated in a site visit, reviewed detailed background materials, and engaged with expert presentations on the management of treated effluent.

The panel agreed that recycling water for long-term security was a priority, reflecting strong community support for sustainable and reliable water sources. Members also recognised the importance of completing the sewage treatment plant upgrade project as a first step to enable future recycling opportunities.