Residents baffled as stormwater in beachside suburb turns bright green
The bizarre sight was spotted in the Sydney suburb of Manly this week with many wondering what it is.
A mysterious fluorescent liquid flowing into a stormwater drain baffled residents this week after one questioned why the gutters in one street had turned bright green.
Photos shared on Facebook on Thursday show Commonwealth Parade in the beachside suburb of Manly in Sydney with puddles of fluro liquid sitting in the gutter's edge. The road sits above Manly Cove beach with residents concerned the liquid may spill out into Sydney Harbour.
"Any idea what this green stuff flowing into the drains is?" asked the poster who seemingly snapped the photos as he walked by.
One suggested it could be "coolant from a car" which "should have a distinctive smell" but the poster confirmed there's no odour suggesting it's likely something different.
Green substance likely 'plumber's dye' often used in drains
It's believed this substance may be fluorescein dye which is commonly used in plumbing or drain testing and dissipates quickly once diluted.
Northern Beaches Council was not aware of the fluorescent water when contacted by Yahoo News Australia and suggested contacting Sydney Water which looks after stormwater outlets across the city. Sydney Water confirmed it was not their doing on this occasion and suggested it was likely a local or private plumber.
"Fluorescein has low toxicity but even small amounts can be highly visual and for this reason its use should always be minimised," an Environment Protection Authority spokesperson previously told Yahoo.
Must 'tread with caution' expert says
Similar reports have been made in waterways across the country. First in a creek in the Yarra Valley and in Rushcutters Bay Park in Sydney. One woman admitted it looked "very strange" as she shared a video on Facebook.
In the past, some residents have expressed concern over its potential toxicity. Fluorescein is said to be "non-toxic to the environment and is odourless," the product's manufacturer says. But we should still tread with caution, Ian Wright, a water scientist and associate professor at Western Sydney University, told Yahoo.
He noted the safety data sheet for the product shows it has several human health risks and should be used very carefully. It also warns "do not let this chemical enter the environment," he pointed out.
"Any chemical product should be used very cautiously. Being able to see a visible stain is a cause for concern," he said. "But perhaps also it has helped a plumber stop a leak of sewage or other wastewater from a natural waterway".
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