Abergeldie carried out the Belmont WWTW Stage 3 Upgrade to enable an increase to the nominal capacity of the existing plant from 85,000EP to 115,000EP. The contract consisted of a package of works to design, construct and install/commission augmentations to aeration systems and grit removal facilities. The scope of works included modification to the existing fine screen to provide adequate bypass capacity; two new vortex–type grit removal tanks and associated facilities; and a new distribution structure and pipework for feeding raw sewage and RAS to five aeration tanks, with allowance for a sixth. All electrical and control services to the plant were also upgraded, including two new transformers and switchboards.
Abergeldie designed an MLE type aeration process to fit within the existing series of tanks, with floor-mounted diffusers. Allowance was made for the MLR pump intakes and the pressure relief wall openings adjacent to diffusers. The design for the graded aeration zone allowed for new generation vertical magnetic bearing turbines, used for the first time in New South Wales, with specific provision for the turn-down required to meet the initial design requirements.
Hunter Water Corporation