

The small grey debris balls that washed up along Sydney beaches earlier this month have been analysed, with findings showing they were comprised largely of soap scum and cosmetics.
Nine beaches along the north, including popular swimming spots like Dee Why and Manly, were closed on January 14 when white and grey balls appeared on the same.
It was the second time these mysterious balls had appeared, with black balls of debris first seen along Coogee and Bondi in October. These were later determined to be a delightful mixture of fats, oils, human hair, soap scum, human faeces, and recreational drugs.
Chemistry professor Jon Beves from the University of New South Wales said this second wave of debris balls were slightly less disgusting, mostly being made up of saturated fatty acids and calcium.
“The ones that we found down at Coogee, they were majority, what looks like cooking oil and the similar sort of fatty acids that we found here, but there were all other things in them as well,” he told the ABC.
“I guess what looked like diesel, which is why they were black. These ones on the North Shore are much simpler composition than the ones we found.”
Beves said the balls were made up of hydrophobic materials commonly washed down the drain, which is why they stuck together.
“They don’t really like water, so they’re just trying to get away from it,” he said.
“And when they find other compounds that also don’t like water, they stick together sort of like glue and this is why they end up being in these sort of lumps, and they form commonly in sewers.”
Sydney Water say no issues reported
Sydney Water released a statement clarifying it was working with the NSW Environmental Protection Authority (EPA) to investigate the possible causes of the balls.
They highlighted that no issues were reported with the operations of Warriewood or North Head Water Resource Recovery plants prior to the debris being discovered.
“We comply with our licences as set by the NSW Environment Protection Authority,” Sydney Water said.
“Sydney Water has developed a long-term capital operating plan, which will see over $30 billion invested in the next 10 years to upgrade and expand our water and wastewater networks.”
Earlier this month, Professor Stuart Khan, head of the school of civil engineering at the University of Sydney says that Sydney’s wastewater system was unusual for a major city in a developed nation.
Current primary water treatments involve physical processes, such as screening out solids and allowing sludge to settle to the bottom, while fat and grease floats to the top. Secondary processing relies on detailed biological processing and filtration, and can rid wastewater more thoroughly of fatty substances.
After primary processing, wastewater is pumped kilometres out to sea to deep ocean outfalls constructed in the 1990s.
“We really are out of step with the rest of the developed world, discharging primary-treated effluent into the Pacific Ocean,” said Khan. “You can’t do that in California.”