A 10-year wastewater upgrade program has been announced after debris balls washed ashore at Coogee, with works focused on the Malabar treatment system linked to the incidents.
When The Debris Balls Appeared
Debris balls were reported on Sydney beaches from October 2024 to January 2025, including at Coogee Beach. The material raised water safety concerns and led to beach closures during clean-up and testing. In January 2025, nine beaches were closed after greasy debris was found on shore.
What Testing Found
Testing by the NSW Environment Protection Authority indicated the debris most likely originated from the Malabar wastewater treatment system.
An EPA update described the material as containing mainly fatty acids, along with a smaller portion of petroleum hydrocarbons and other materials such as human hair and fibres.
What The Upgrade Program Covers
A $3 billion investment program is planned over 10 years to reduce the volume of wastewater needing treatment and discharge through the Malabar deep ocean outfall.
The Malabar system is one of the largest wastewater networks in Australia and services close to two million people, including areas such as Fairfield, Campbelltown and Liverpool.
First Facilities In Line
Early works are set to upgrade the Glenfield and Liverpool facilities, including refurbishments and expanded processing capacity. A secondary treatment process is planned for Liverpool as one of the first major developments.
Other Steps Alongside Construction
Additional measures flagged as part of the response include increased cleaning and inspection of ocean outfall screens, tighter trade-waste controls for higher-risk customers, and an expanded education campaign targeting fats, oils and grease entering the network.
What Happens Next
Sydney Water, the NSW EPA and an independent wastewater expert panel are expected to continue working together over the coming decade to reduce the likelihood of debris balls reappearing on beaches, including Coogee.
Most disruption is expected to be localised near facilities, mainly construction noise and truck movements.
Published 19-Jan-2026
