Woronora Pilot Plant Operation


CWT provided assistance in operating the Woronora Water Filtration Plant (WFP) as part of an urgent investigation into identifying differences between the WFP operating and design capacities with an imminent need to increase production to full capacity coinciding with a significant dirty water event of escalated raw water colour and DOC. CWT’s recommissioning and operation of the pilot plant to identify the optimal WFP operating parameters to maintain both critical supply and contractual treated water quality standards was followed by a comparison of the suitability of different polymer strength options to relieve pump stress.

Services Offered

  • Analysis of high rate filtration against contractual treated water quality targets
  • Research into treatment of raw water with high colour and organic carbon content
  • Training of operators in pilot plant operations
  • Trials to compare polymer strengths
  • Analysis of chemical dosing and existing pump capabilities
  • Jar testing


Veolia had issues with the design capacity of 166 ML/day only operating at an average of 40 ML/day which is a significant difference in operating and design capacity. With an imminent need to increase production to design capacity to maintain critical supply to southern Sydney during network shutdowns of other treatment plants, the significant increase in production required careful analysis and consideration by the team to ensure capacity requirements were achieved without detriment to treated water quality.

Additionally, the WFP required optimisation to ensure treated water quality was maintained due to heavy rainfall in the catchment that resulted in an escalation in the raw water colour and DOC levels which increased the incoming loading on the WFP.

With WFP production at less than 1/4 of its design capacity, operational problems were created with pumps’ ability to maintain steady, low flows and introduced the risk of overheating. Therefore, an investigation into the use of lower polymer product concentration was required to relieve stress on the pumps.


CWT carried out a pilot plant study at the Woronora WFP to investigate the ability to maintain contractual treated water quality standards whilst operating at the maximum design rate in conjunction with periods of elevated colour and turbidity in the source water.


CWT’s pilot study work identified the optimal coagulant and polymer doses required to balance treated water quality while maximising filter runtimes and demonstrated that the Woronora WFP would be able to increase its production rate to design capacity in order to meet network demand despite the deterioration in raw water quality.

During the course of the pilot trials, CWT also demonstrated to Veolia operators the recommissioning, preparation and maintenance of the pilot plant. Demonstrations were also provided to senior Veolia and Sydney Water representatives as part of discussions of the WFP’s ability to meet demand.