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Technical Papers
AUGMENTATION OF THE SCHEME STAGE 1 A WORKS
Due to the amount of existing infrastructure, comprising the existing REMS, four WWTPs and the distribution and storage system connecting to the 24 end users, various permutations
All except two end users of the REMS are located downstream of Vincentia WWTP, thus a two-pronged approached has been selected for the upgrade of the Stage 1A plants: • A retrofit of UV treatment systems at three out of four of the existing Stage 1A plants, Vincentia, Culburra and Callala treatment plants to bring the existing REMS outlined in the AGWR; • Separate treatment or approach for the two other end users located on the transfer main from St Georges Basin WWTP to Vincentia WWTP.
STAGE 1 B WORKS
Nowra WWTP’s (first commissioned 1937, shown in Figure 2) and Bomaderry WWTP’s (first commissioned 1972, shown in Figure 3) current treatment capacities are 12,500 and 21,000 equivalent people respectively. The infrastructure at these plants is in need of repair as the assets age, and further capacity is required to provide for current and future development in the catchments of these plants. The effluent from these two plants is currently being discharged to local waterways that drain to the Shoalhaven River. Neither plant is connected to the REMS as the effluent quality does not meet the requirements for reclaimed water, and effluent transfer infrastructure is not in place.
SEPTEMBER 2014 WATER
WATER REUSE
Stage 1A plants are currently fitted with chlorination disinfection. This treatment alone does not achieve the required pathogen Log Reduction Values (LRVs) defined by the AGWR, for the authorised end uses of the reclaimed water. Shoalhaven Water is ultimately responsible for the quality of the reclaimed water, and needs to ensure that it can be validated, verified and controlled.
were investigated to bring the REMS Stage 1A effluent in line with the AGWR requirements.