The last batch of swords was removed from the harbor’s beaches this week, Northern Beaches Council said in a statement on Tuesday.
He urged anyone who spotted the swords not to pick them up and to contact the authorities.
In addition to acids and bacteria, the balls also contained volcanic pumice.
Northern Beaches Mayor Sue Hynes said she hopes the EPA’s analysis will “identify the source so they can stop it at other beaches.”
“We continue to carry out regular inspections of our beaches and encourage the public to report any sightings,” she said.
The first batch of litter in October they were 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.
Scientists said they resembled grease, oil and grease stains – often called “grease slides” – that commonly form in sewage systems.
But Sydney Water said its water treatment plans were working fine and that the city had no known problems with its waste systems.
