Sydney Water’s Malabar Wastewater Treatment System has been identified as the likely source of debris balls that washed up on New South Wales beaches between October 2024 and February 2025.
Evidence collected by Sydney Water under an EPA Preliminary Investigation Notice, has narrowed the origin of the debris to within the Malabar system.
The EPA’s Independent Wastewater Expert Panel, which was established to investigate the source of the debris and provide independent scientific advice, reviewed this evidence in September, and has recommended Sydney Water undertake further investigations.
This work is underway and will inform Sydney Water’s short, medium, and long-term strategies to reduce the likelihood of a similar incident from recurring. This work is expected to be completed by the end of 2025.
The EPA first received a report of debris balls on Dee Why Beach in October 2024.
Lifeguards from Northern Beaches Council inspected beaches in the area and found ball-shaped debris on nine beaches: Manly, Dee Why, Long Reef, Queenscliff, Freshwater, North and South Curl Curl, North Steyne and North Narrabeen.
NSW EPA completed extensive chemical analysis of the balls and in late 2024 shared test results identifying that the debris contained fatty acids and petroleum hydrocarbons, as well as organic and inorganic materials.
For more information, visit: www.epa.nsw.gov.au/
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