Thursday, 13 February 2025

No treatment process failure at Shotover Wastewater Treatment Plant

Floating material seen at the surface of the facility’s clarifier is typical and expected

Treated water from Shotover WWTP is blended with treated water from the alternative treatment process (oxidation pond), receives UV disinfection, and is then discharged into the disposal field.

There is no issue currently with the treatment process of Queenstown Lakes District Council’s (QLDC) Shotover Wastewater Treatment Plant (WWTP), despite a recent media report to the contrary.

Some floating material at the surface of the facility’s clarifier is typical and reflects normal operation. The clarifier mechanism separates this material from the settled water, before it is then discharged from the tank prior to receiving Ultraviolet (UV) disinfection. The collected floating material is then returned to the front of the plant for re-processing.

The plant's operational team undertakes daily testing for a number of parameters to aid them with the operation and optimisation of the treatment process. In the sample analysed on Wednesday 12 February 2025, Total Suspended Solids (TSS) were measured at 1.3mg/L - well within the facility's mean target of 30mg/L.

These results are consistent with the most recent sampling results returned from an external and independent laboratory which completes testing for consent compliance purposes. TSS in this sample taken on Friday 24 January 2025 measured at 5.4mg/L - also well within the facility's mean target.

The below photos taken yesterday afternoon reflect the excellent treated water quality the plant is currently achieving.

ENDS | KUA MUTU.