Sydney Harbour West WWTP A New-Build Wastewater Treatment Case Study
Sarah Ensslin, Holly Sampson (CBCL Limited)

The wastewater collection system in the Sydney Harbour West SHW region was until recently discharging untreated wastewater through three separate marine outfalls to Sydney Harbour. There are a number of other communities in CBRM that do not have wastewater treatment. Due to a changing regulatory environment, CBRM is working toward intercepting and treating the wastewater in these communities prior to discharge, and the construction and commissioning of the SHW WWTP is an important step in the path to full treatment of wastewater in the region.

The SHW WWTP is a three-cell Sequencing Batch Reactor facility with a design average day flow of 11,600 m’³/day., Construction started in 2021, and the plant was commissioned in 2023. Wastewater from Sydport, Westmount and Coxheath was intercepted and pumped to the WWTP site just outside of the community. The treatment facility includes a headworks, secondary treatment, disinfection, an aerobic sludge holding tank, and sludge dewatering, and has an admin building, process building, and maintenance garage on the site, along with the process tanks.

Data from the design phase as well as from commissioning and the first several months of operation will demonstrate the improvement in the effluent quality reaching Sydney Harbour, as well as cover the challenges encountered with design and commissioning of the WWTP. An overview of CBRMes next steps towards implementing wastewater treatment in other communities will also be discussed.