The mysterious balls that forced the closure of several beaches in Sydney last week were found to contain saturated acids, E. coli and faecal bacteria, authorities say.
Sydney’s Northern Beaches council said it has sent the debris to the New South Wales Environment Protection Authority ( EPA ) for further analysis.
Nine shores, including common areas Powerful and Dee Why, were closed on 14 January after the marble-sized balloons started washing up.
It came weeks after thousands of black spots started appearing on the state’s shores in October, prompting regulators to close some of its most famous beaches for several days and get a large clean-up.
The latest batch of balloons was cleaned up from bay shores this year, the North Beaches committee said in its statement on Tuesday.
It urged everyone who spotted the balloons not to control them and to call authorities.
Besides the acid and bacterium, the balls even contained volcanic rock ash.
North Beaches president Sue Heins said she hopes the EPA study did “identify the supply so that they can stop this from happening at different beaches”.
” We are continuing to perform regular audits of our shores and encourage the group to record any sightings,” she said.
The first batch of debris in October were at first mistakenly called “tar balls” but were later found to contain everything from cooking oil and soap scum molecules, to blood pressure medication, pesticides, hair, methamphetamine and veterinary drugs.
Researchers said they resembled overweight, oil and grease blobs- generally called “fatbergs”- which are generally formed in wastewater systems.
But Sydney Water has reported that its water treatment programs are operating generally and that there were no known issues with spare devices in the area.