By The Guardian (World News) | Created at 2024-09-26 04:30:12 | Updated at 2024-09-30 15:28:35
4 days ago
Residents in one of Sydney’s most affluent neighbourhoods were shocked to discover a bright green substance leaking into the harbour on Wednesday.
The colouring was spotted in Careening Cove at Milson Park, Kirribilli, near the city’s central business district and home to one of the prime minister’s official residences.
One local told 9News the water resembled “green cordial” and the “radioactive stuff you see in superhero movies”. However Supt Adam Dewberry from Fire and Rescue NSW said there was no indication the substance was toxic and it is most likely a fluorescein dye.
He compared the unplanned occurrence to the annual St Patrick’s Day event in Chicago, during which the river is temporarily dyed green.
The dye had come out of a storm water drain in Kirribilli – an old suburb at the bottom of a large hill – so Dewberry said there are “thousands of areas where it could have entered”.
“So it’s unlikely we’ll be able to identify the source, where it did come from, because there’s just so many access points into the storm water … in that area,” he said.
“The main thing is we’ve identified it’s non-toxic … There’s no evidence of any marine damage, fish kills, [and] there’s no staining on any of the boats that are in the bay there, or around the wharves or the shoreline.”
Water expert and professor of environmental engineering at UNSW, Stuart Kahn, said fluorescein is used as a flow tracer, to determine whether pipes might leak or where they might flow to.
“That’s its normal use. Clearly in this case it’s been misused,” he said.
Normally a teaspoon of fluorescein would be used, with “even very small amounts [producing] a very visible, intensive colour that can hang around for a long time”.
“Even if somebody was doing a legitimate task … they’ve used way too much of it,” Prof Kahn said. “It’s a massive amount. It’s probably a whole bucket full of fluorescein dye.”
North Sydney council said its rangers also attended the site on Wednesday, with spill socks placed into the storm water channel to stop further pollution from entering the bay. Council engineers also believe the substance to be fluorescein, and said the drainage network was clear of the green water by 6.40pm.
Kirribilli also received around 10mm of rain overnight, as much of Sydney copped a drenching into Thursday. Dewberry visited the bay in the morning and said it had all been flushed out and diluted, after flowing for up to eight hours.
Dewberry said FRNSW had spoken with Sydney Water, which said it had not used the dye in the area.
There are a number of theories as to what caused the fluorescein spill, including a potential year 12 “muck-up day” prank. Prof Kahn said this was “plausible”, though could also be a result of “misuse or poor practice for its intended purpose”.
He said the rain might also be a potential factor.
“It might have been sitting there in a storm water system for a couple of weeks or something, and it might just be the fact that it started raining that’s washed it out,” he said.
