Sydney Harbour water glows bright green after mysterious leak

Water in Sydney Harbour was bright green after a substance leaked into a stormwater drain on Wednesday, 25 September.

Fire and Rescue New South Wales (NSW) said they quickly investigated and determined the spill near Milson Park, Kirribilli, was non-toxic.

Fluorescein, a chemical used by plumbers to dye water and find leaks, is thought to be behind the colour change, superintendent Adam Dewberry said.

“We can’t say for sure but that’s what we think it is,” he added.

Emergency services confirmed that there was no vapour or odour to the substance, and there was no evidence of damage to the environment.

Fire and Rescue NSW said the source of the spill was still ‘unclear’ but said it appeared to be flowing from a stormwater drain.