Dredging has turned the colour of the sea at St Kilda beach jet black, but authorities say there is no immediate threat to people’s health or the environment.
A broken sewage pipe in nearby Acland Street is contributing to the foul odour caused by the dredging.
People have been advised not to swim at St Kilda or touch the water while dredging is under way.Credit: Joe Armao
St Kilda Marina has been dredging at the entrance channel near Blessington Street since Monday, as part of a week-long operation to deepen the channel to allow vessels to pass unhindered.
Marina manager Judi Finn said the discolouration of the sand – which also turns the water black during dredging – was normal.
“We do sand testing prior to any dredging works being done so we know it’s not contaminated,” she told this masthead.
“It comes out black and once it goes onto the beach they spread it out, and it dries and oxidises, and then it turns white.”
Dredging at the entrance of the St Kilda Marina channel on Wednesday.Credit: Joe Armao
The deep colour of the sand comes from naturally occurring organic material, including decomposed plants and animals on the sea floor. As it is dredged up, sulphur is also released, contributing to the strong smell.
Workers are currently dumping the dredged sand onto the beach at Shakespeare Grove, near Luna Park. While it is smelly – locals on social media describe it as sulphuric, like rotten eggs – the Environmental Protection Authority said it should dissipate within days.