Mystery balls that It forced the closure of many beaches Authorities say saturated acids, E. coli and fecal bacteria were found in Sydney last week.
Sydney's Northern Beaches Council said it had sent the wreckage to the NSW Environment Protection Authority (EPA) for further analysis.
Nine beaches, including popular sites Manly and Dee Why, were closed on January 14 after marbles began washing away.
This came months after thousands of black dots appeared on the city's coast in October, prompting authorities to close some of its most popular beaches for several days and order a massive clean-up.
Northern Beaches Council said in its statement on Tuesday that the last batch of balls were cleaned from the harbor beaches this week.
She urged anyone who spots the balls not to handle them and to contact the authorities.
Besides acids and bacteria, the balls also contain volcanic pumice.
Northern Beaches Mayor Sue Hynes said she hoped the EPA's analysis would “identify the source so they can prevent this from happening at other beaches”.
“We continue to conduct regular inspections of our beaches and encourage the community to report any sightings,” she said.
the The first batch of debris in October They were initially mistakenly called “tar balls” but were later found to contain everything from cooking oil and soap scum particles to blood pressure medications, pesticides, hair, methamphetamine and veterinary medicine.
Scientists said they resemble the clumps of fats, oils and grease – often called “fat mountains” – that commonly form in sewage systems.
But Sydney Water reported that its water treatment plans were operating normally and that there were no known issues with the city's waste systems.
