UPDATE: Authorities have confirmed the cause of the bizarre, sticky grease balls that have plagued Sydney beaches since October 2024. The culprit? The Malabar Wastewater Treatment System, which has been identified as the source of these tar-like debris balls, known as fatbergs.
Investigations by the NSW Environment Protection Authority (EPA) suggest that these grease-laden globules formed within the system’s tunnels, which expel treated water into the ocean approximately 3.6 kilometers offshore. This disturbing phenomenon closed popular beaches—including Bondi, Bronte, and Dee Why—at various times until the end of summer, affecting residents and tourists alike.
The EPA’s findings, shared in an urgent statement on Friday, reveal that the Malabar system stands out due to its intake of industrial waste, which is less prevalent in other wastewater systems. The investigation is expected to help Sydney Water develop new strategies to prevent future incidents.
In addressing the ongoing issues, NSW Water Minister Rose Jackson emphasized the urgency of maintaining the city’s wastewater systems. “Sydney Water is now working to prevent future events through new programs to help reduce the amount of fats, oils, and grease entering the wastewater system,” she stated. The government plans to invest hundreds of millions of dollars in maintenance and upgrades over the coming decades to ensure the sewage system can handle the demands of a growing city.
The mysterious balls, which began appearing at Coogee Beach, contained a mix of human waste, industrial runoff, and a shocking array of components, including cooking oil, soap scum, and even pharmaceuticals. Testing revealed that these globules were primarily composed of fats and oils, confirming their classification as fatbergs—large masses that form when fat, oil, and grease bind together with debris like wet wipes.
The impact of these fatbergs is not insignificant; they cost Sydney Water approximately $27 million annually to clear. The Malabar Treatment System, while efficient at removing solids, fails to adequately address the fats and oils, which can be broken down using bacteria. The EPA now suspects that the fatbergs are reforming within the pipes themselves, leading to ongoing contamination and environmental concerns.
In a related note, a 2020 CSIRO report indicated that the Malabar catchment released between 5.4 billion to 120 billion microplastic particles into the ocean each day, a staggering figure that underscores the urgency of addressing these environmental challenges.
As the investigation continues, beaches remain on alert for further occurrences. Residents and beachgoers are urged to stay informed about updates and potential beach closures as authorities implement new measures to mitigate these issues. The situation remains fluid, and all eyes are on the EPA and Sydney Water as they work to resolve this urgent public health concern.
Next steps: The EPA aims to finalize its investigation by the end of the year, with recommendations that could reshape how Sydney manages its wastewater. As the city prepares for a changing environment, the importance of maintaining clean beaches and safe waters has never been more pressing. Stay tuned for the latest updates as this story develops.


































