Sydney's beaches have been plagued by 'poo balls' originating from a massive fatberg trapped in an inaccessible chamber at the Malabar wastewater treatment plant. The fatberg, estimated to be the size of four buses, has been depositing congealed fats, oils and grease (FOG) onto beaches including Coogee, Bondi and Manly, forcing closures in late 2024 and early 2025.
The fatberg lies beyond a rusty bulkhead door in a 300-cubic-metre underground chamber. Sydney Water has been unable to determine its exact size because a drone sent to inspect it could not fly straight due to turbulence from sewer gases and rapid effluent flow. The corporation believes pieces break off during pressure changes caused by power losses or heavy rain, then pass through diffusers at the end of a deepwater ocean outfall 2.3km out to sea before being carried back to shore by waves and wind.
In February 2025, the NSW Environment Protection Authority issued a pollution reduction program requiring Sydney Water to remove fat from the Malabar outfall area. However, accessing the main fatberg is problematic. A five-metre area behind the bulkhead door can be reached during low flow, lunar low tides and minimal rainfall, but the main chamber beyond wooden stopboards remains untouched. Crews can pump out spillover from the accessible area every four to six months, removing 53 tonnes in April 2025, but more material re-accumulates.
Sydney Water says the only way to clear the fatberg fully would be to shut down the ocean outfall for months and dump primary-treated sewage at the cliff face—a strategy deemed unacceptable in a secret August 2025 report obtained by Guardian Australia. The report noted this had never been done and was no longer considered acceptable. Fiona Copeman, the plant's hub manager, has worked at Malabar for nearly 15 years and described the FOG's consistency as sometimes gritty or scummy, adding that staff have handled it to understand its composition.
