Mysterious black balls that appeared across popular beaches have been identified as disgusting clumps of human faeces, drugs and forever chemicals.
University of NSW chemistry professor Jon Beves had the extremely unpleasant task of subjecting the balls - which first appeared on Sydneys Coogee Beach on October 16 - to analysis with shocking results.
His team found the balls were fatbergs, or FOG (fat, oil, grease) aggregates, which could only be formed in a sewerage system.
The findings ruled out Randwick Councils earlier conclusion that the lumps were tar balls created from an oil spill or ship leakage.
Aside from human waste - cooking oils, diesel or fuel and recreational drugs, including THC and methamphetamine, were also found in the balls.
I always expected them to be like crude oil or … even heavy oil, it doesnt smell that bad but this really smells disgusting. It smells more like what youd expect in a sewer. They really are gross, Professor Beves told the Sydney Morning Herald.
Also discovered were PFAS chemicals - a type of plastic often referred to as forever chemicals - but the types found differed from those at the centre of drinking water safety discussions.
The chemicals discovered were instead more closely aligned with those found in waterproof clothing.
Mysterious black balls (pictured) that appeared across Sydney beaches last month have been identified as disgusting clumps of human faeces, drugs and forever chemicals
The balls were found to be fatbergs, or FOG - fat, oil, grease - aggregates, which could only be formed in a sewerage system
Other elements found in the balls included medications for high blood pressure, birth control and steroids - all of which typically show in sewerage testing.
Professor Beves tests made his team unpopular around the UNSW campus due to their smelly nature.
Despite their efforts, questions around the origin of the balls still remain.
I dont know if its come from our local sewer system, or if its been discharged from a boat, or if its been washed from the sewers into the stormwater, or some other origin that we really dont know, he told the ABC.
However, testing suggests the balls all came from the same place as they were similar in composition.
So it seems they havent come from many different locations, theyre consistent with all coming from one location at one time, Professor Beves said.
The balls were originally reported in Coogee but spread to Bondi, Bronte, Tamarama and Maroubra beaches in the following days.
All the affected beaches were immediately closed and a massive clean-up effort was taken by Randwick Council.
Other elements found in the balls included medications for high blood pressure, birth control and steroids - all of which typically show in sewerage testing
Questions around the origin of the balls still remain with local sewerage systems or boats possible suspects
Its initial testing indicated the balls were made of oil and were a danger to beachgoers health.
Sydney Water stated there were no issues with its deep ocean outfalls at Malabar, Bondi and North Head.
The systems discharge wastewater three kilometres off the coast and 60 to 80 metres below the surface.
The Environmental Protection Authority hopes final tests due in the coming weeks will reveal the balls source.