Winmalee Sewerage Treatment Plant Upgrade

Winmalee Sewage Treatment Plant (STP) is located next to Agnes Banks Nature Reserve in New South Wales, Australia.

Winmalee Sewerage Treatment Plant (STP) was originally commissioned in 1984, with Stage 2 amplification in 1992 and Stage 3 amplification (4 x SBRs – 16.4 MLD – 4 x Filters) in 1998. A Pollution Reduction Program was imposed in July 2015, which required Sydney Water to reduce the nutrient loads from Winmalee STP.

Cardno, now Stantec was engaged by Downer in 2020 to undertake the complete Civil and Structural design (along with construction support services) associated with the upgrade, which included:

  • New Inlet Works,
  • MBR,
  • Blower / Switchroom,
  • Chemical Storage Facilities,
  • Dewatering Facility, 
  • Roads, Earthworks and Underground Pipework.

Our team worked closely with the Downer engineering and construction team, along with other key stakeholders to deliver the Civil and Structural design of this significant Sydney Water project within tight timeframes. Successful design delivery was enhanced through the completion of the design in a fully integrated 3D environment.