A huge fatberg has just been found in the deepwater ocean sewer system of Malabar. This sizeable block could be as big as four Sydney buses and had been forming since the system opened in 1990. Eagle-eyed experts suspect the fatberg lurks in a 300 cubic meter cavern past the Malabar outfall’s stopboards. Given the potentially long-lasting impacts of PFAS on local beaches and marine life due to this discovery, this is a grim find.
The Malabar outfall, which extends 2.3 kilometers offshore, has sparked the interest of environmentalists. Recent marine pollution incidents have involved debris balls and tar balls washing up on Sydney’s beaches, raising widespread concern over marine pollution. Experts warned that the recent influx of Fats Oils and Grease (FOG) into the wastewater system has shot up. In fact, it has grown by 39% in the last 10 years. This expansion has been accompanied by a shocking 125% increase in volatile organic compounds. Examples of these are everyday products like cleaning products, cosmetics, and paints that enter the system.
During the week of 20 April 2025, Sydney Water pumped out 53 tonnes of FOG and accumulated waste material from the Malabar system. None of the root causes have gone away. In response, the New South Wales Environment Protection Authority (EPA) is preparing an Independent scientific assessment report on the deepwater ocean outfalls. This report, released August 30, 2025, highlights the immediate need for repair and upgrade of the system.
In addition, with the treatment plant losing power, this stopped the pumping of raw sewage for several minutes. This outage compounded all of these issues. This incident probably caused the first appearance of poo balls on Coogee Beach on October 15th, 2024. On January 11, 2025, a wet weather event led to a loss of system pressure. This alteration dislodged a portion of the fatberg and led to repeated, additional pollution episodes.
The Malabar system today only does a primary treatment of sewage, mostly just separating out solids. In order to address the fatberg, we need to temporarily take the outfall offline for maintenance. This will require rerouting all of the sewage to a new underwater “cliff face discharge.” This move would shut Sydney beaches and other open spaces for months.
In light of these challenges, Sydney Water has outlined a substantial investment program estimated at $3 billion over the next decade. This funding will help reduce the amount of wastewater that needs treatment and discharge through the Malabar deep ocean outfall.
“Malabar system investment program estimated at $3bn over the next 10 years.” – Rose Jackson
Sydney Water noted that tar balls could have absorbed pre-existing wastewater discharge. They explained that these tar balls were not created outright because of their activities. In response to inquiries, a spokesperson assured that both the Bondi and Malabar wastewater treatment plants continue to operate without incident. Not one challenge has disrupted their business as usual.
“Sydney Water acknowledges that the tar balls may have absorbed wastewater discharge, which was already present in the water while forming; however, they did not form as a result of our wastewater discharges.” – Sydney Water spokesperson
In response to this outcry, the EPA assured the public that all Sydney Water facilities were operating within their environmental licenses. They functioned as they were intended to throughout these emergencies. Any future regulatory results or possible fines will be decided solely by the EPA.
“The EPA has advised that all Sydney Water facilities involved were operating in compliance with their environment licenses during the events. Any regulatory outcomes, including potential penalties, are determined independently by the EPA.” – Sydney Water spokesperson
To prevent more from happening in the future, Sydney Water intends to undertake a detailed investigation into changing operational and maintenance practices. This entails increased frequency of inspections in public-facing spaces and improved management protocols to deal with fats, oils and greases.
“We are reviewing operational and maintenance practices, including regular inspections of accessible areas, and strengthening fats, oils and grease management through ongoing cleanouts, trade waste customer engagement, source control reviews, and community education on proper disposal practices.” – Sydney Water spokesperson
Environmental advocates, including Sustainable Seattle’s Jeff Angel, emphasize that upgrading our sewerage system is essential to stopping these problems from happening again.
“The outfalls are old school technology, and our sewerage system needs to be modernized.” – Jeff Angel
Sydney Water are currently going through the process of reviewing their environmental protection license. They have convened a panel of wastewater experts to help tackle the build-up. The agency said it is hoping to finalize these license variations by the middle of February.
“As part of Sydney Water’s environment protection licence review, we are considering this build-up in consultation with the wastewater expert panel.” – Sydney Water spokesperson