Mt St John Wastewater Purification Plant
Hunter Water Australia (HWA) has been involved with Townsville City Council (TCC) water and wastewater treatment plants for over 15 years. Commencing 2007, HWA and its partner AECOM have worked closely with TCC to develop an augmentation plan for their ageing WPP. This occurred during a difficult time where two local councils, Thuringowa and Townsville, were amalgamated into one Council.
Savings of $80M
The amalgamated treatment involved combing the sewage from the Mt Low, Deeragun and Mt St John plants into one new plant at Mt St John. The strategy also involved refurbishment works at Condon WPP. This strategy was termed the Wastewater Upgrade Program (WUP), and resulted in savings of over $80M compared to previous augmentation strategies.
The Mt St John plant was designed with a strong focus on reliability and lowest whole of life costs. It is a full Biological Nutrient Removal plant of 106,500 EP capacity. It uses oxidation ditch technology configured as a 5 Stage Bardenpho to achieve better than 5 mg/L total nitrogen and 1 mg/L total phosphorus.
The plant uses aerobic digestion to stabilise waste activated sludge. HWA adopted the latest research into aerobic digestion to ensure a higher degree of biosolids stability in comparison to conventional aerobic digestion designs.