Sydney Water is developing a new pre-treatment plant for the Prospect water filtration plant, which, according to Alfa Laval, supplies around 85% of Sydney’s population, some 5.4 million people. It is being designed and built by a Suez-Acciona joint venture, which won the A$322 million (€199 million) contract, according to Acciona.
The plant will have an initial capacity of 500 megalitres a day. According to Acciona, it will include intake screening, an advanced clarification process, chemical storage and dosing, a residuals handling system, an administration building and site services.
Alfa Laval has published a case study on its part in the project: the supply of four Aldec 50 decanter centrifuges for the pre-treatment sludge. According to the company, the existing plant had run on decanter centrifuges for more than 25 years but struggled to cope with extreme peak flows after heavy rain, and the project partners chose a new pre-treatment facility rather than upgrading the existing equipment. Alfa Laval says that, before construction, it ran laboratory tests on water from Prospect, adding mud, sand and other materials to recreate some of the toughest raw water conditions, and that one centrifuge would be enough under normal load, with more coming online in bad weather, up to all four at once.
Construction is under way, and Sydney Water expects the plant to be operational in late 2027.
Sources: Alfa Laval, 20 October 2026 (in Spanish); Acciona, contract award, and Sydney Water, project page. Image: aerial view of Prospect Reservoir (Sydney), February 2016. Bidgee, CC BY-SA 3.0 AU, via Wikimedia Commons (cropped).
