Melbourne Water Corporation’s Eastern Treatment Plant (ETP) processes 40 percent of Melbourne’s wastewater each day and serves 1.6 million people. It is the second-largest wastewater treatment plant in Australia and the largest activated sludge plant in the Southern Hemisphere.
The ETP produced chlorinated secondary effluent, which was discharged via a 56-km pipeline into the ocean. The discharge point at Boags Rocks was through a nearshore outfall, and the discharge was apparent to beach users and surfers.
Class A Recycled Water
In 2006, the Victorian Government announced that the ETP-treated effluent discharge was to be upgraded to reduce its environmental impact. The Eastern Tertiary Alliance (ETA), including Melbourne Water and Black & Veatch, was subsequently formed to deliver the plant upgrade.
Black & Veatch selected a process train of ozonation, media filtration, ultraviolet irradiation and chlorination that provided significant improvements to the quality of discharge into the environment.
The process also produces Class A recycled water that can be used by the community. This has avoided the significant costs of extending the nearshore outfall.