Bowral Sewage Treatment Plant upgrade taking shape

Bowral residents are one step closer to having a world-class wastewater treatment plant, with construction complete on the first stage of a multimillion-dollar overhaul that will future- proof the local sewerage system for decades to come.

The project is being delivered thanks to $6.6 million from the NSW Government’s Safe and Secure Water Program and over $26 million from Wingecarribee Shire Council.

Sewage generated within Bowral, East Bowral and Burradoo is transferred through gravity sewers and sewage pump stations to the Bowral Sewage Treatment Plant which hasn’t been upgraded since 2006.

While the plant is still functioning well and meeting environmental standards, it is now operating near its capacity. Once fully complete, the upgrade will increase the plant’s capacity by 50 per cent, allowing for local population growth while also ensuring better efficiency and improved protection for local waterways.

The first phase of the project involved the installation of a new bioreactor, clarifier and inlet works to improve the removal of substances such as nitrogen and phosphorus. These Stage 1 works will enable a more consistent treatment process which is more resilient in responding to changes in the incoming raw sewage.

The improvements will also better safeguard the health of the Wingecarribee River, which sits upstream and flows into Lake Burragorang, part of Sydney’s drinking water catchment.

In 2023, the construction contract was awarded to Haslin Construction after a competitive tender process, with the project due for full completion in early 2026.

Government Spokesperson for Wollondilly Mark Buttigieg MLC said:

“It’s exciting to see this highly anticipated overhaul begin to take shape, equipping the Bowral Sewage Treatment Plant with the latest technology including new bioreactors, odour control, an additional emergency storm pond and a new UV system.

“All these changes will ensure the effluent released by the plant continues to be maintained to the highest standard, helping protect precious local ecosystems.

“I’d like to thank everyone involved, from the NSW Government and Council for their generous investments, to the local contractors on the ground bringing this project to life.”

Member for Wollondilly Judy Hannan MP said:

“Quality sewage services are vital in helping to support growing populations, and the Southern Highlands has become a popular tree change location, which is why it’s so important Bowral has the infrastructure it needs to thrive.

“This will be a massive win not only for the community who will have a more reliable system, but also for the environment which will be better safeguarded thanks to these upgrades.

“I look forward to seeing the final product in early 2026 and the positive impact it will have in years to come.”

Wingecarribee Shire Council General Manager Lisa Miscamble said:

“Council's strategic engagement of Haslin Construction, a respected specialist in the area, has delivered a welcome economic boost. Their procurement process prioritised collaboration with local contractors and facilitated staff contributions to local spending.

“Moving this project forward is a major win for residents, businesses, and the environment, while also supporting the implementation of Council's housing targets.

“This is all about looking down the track and recognising the need to get the right infrastructure in place for the long term. Reaching this stage 1 milestone is a significant achievement, bringing us closer to the project’s highly anticipated completion.”