ACCIONA, in partnership with SUEZ, has completed the installation of the dome lid on the first of two thickened sludge tanks at Sydney Water’s Prospect Pre-treatment Plant, marking a significant milestone in the project’s construction schedule.

The installation is part of a major upgrade to Sydney’s water supply system, designed to improve resilience and reliability for the Prospect Water Filtration Plant, which supplies nearly 85 per cent of Sydney’s households.

Boosting storage capacity

The two tanks will provide a combined storage capacity of 8,000 cubic metres of thickened sludge removed from raw water during treatment.

This capacity allows the plant to store up to five days of sludge during periods when disposal sites are inaccessible, ensuring continuous operation even under challenging conditions.

The successful placement of the dome lid required precise planning and coordination to safely execute the heavy lift on site.

A critical piece of Sydney's water security

The Prospect Pre-treatment Plant will process up to 625 million litres of raw water per day. It incorporates advanced clarification systems, chemical dosing facilities and residual handling processes to manage waste effectively. The project is a critical component of Sydney Water’s strategy to maintain water quality during extreme weather events such as storms, droughts and bushfires.

Once complete, the Prospect Pre-treatment Plant will provide additional treatment for raw water to support the water filtration plant. This will allow the Prospect Water Filtration Plant to continue providing safe, secure and reliable drinking water during periods where raw water quality has been impacted.

Next steps for construction

The installation of the first dome lid represents a key step toward completing the residual handling system, which is essential for the plant’s overall operation.

Work on the second sludge tank is progressing and will follow a similar process to achieve full storage capacity.

The Prospect Pre-treatment Plant is expected to play a vital role in safeguarding Sydney’s water security for decades, providing infrastructure that can adapt to changing climate conditions.

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