Sydney’s beaches have been hit by foul-smelling debris balls because a giant “fatberg” is blocking part of a major sewer near the Malabar wastewater treatment plant.
The balls have washed up from the Central Coast to the South Coast, and Malabar Beach has been closed more than once because of the mess. A fatberg is a hard lump made from built-up fats, oils and grease mixed with items that should not go down drains.
The blockage may be as large as four buses, but its full size is hard to measure. The worst part sits in a dangerous, hard-to-reach tunnel section, so crews cannot safely scrape it all out. Even so, 53 tonnes of grime was removed in April last year.
Inside the sewer system, sewage flow appears to skim past the fatberg and break off pieces. Those pieces can form into balls and get released into the ocean about three kilometres from the Malabar plant. A power failure on 13 October 2024 caused a surge of fast-flowing water, which likely helped push more material through. Wet weather can also force the debris to escape, and ocean currents then roll and smooth the pieces into rounder balls.
Cleaning up has been costly, with Randwick City Council spending about AU$500,000 on specialist clean-ups, which Sydney Water agreed to pay.
