Authorities have taped off a Tatterson Park wetlands, which has been polluted by a 23,000-litre spill of sewage.
A blocked sewer at 90 Lake View Boulevard Keysborough was discovered by South East Water about 9pm on Monday 24 April.
The blockage was caused by a build-up of tree roots and fats, resulting in overflow into the adjacent wetlands, SEW acting service delivery general manager Glenn Goldsmith said.
Water-quality testing found elevated levels of E.coli close to the spill site.
Crews acted immediately to contain the spill, he said.
“This included sandbagging, flushing and eduction (removal), and cleaning and disinfection of the site.
“The area remains taped off to the public and signage put in place, asking community members (and their animals) not to use or handle the water in the wetlands.”
Water-quality sampling was continuing at the wetlands and downstream at Mordialloc Creek.
“While water testing indicates that E.coli levels at the site of the spill are declining, advisory signs will be in place until we receive further water quality results for the area, and it is declared safe.
“We utilised our Environmental Sensitivity Mapping tool to confirm that no sensitive flora or fauna in the wetlands was impacted by the spill.”
Mr Goldsmith said it was the first time that the pipeline had blocked.
“At South East Water, we do everything possible to avoid spills, including using monitoring sensors with alarms that detect potential blockages or overflows across our sewer network.
“We’re investigating to clear any further restrictions along this pipeline to prevent any spills from happening again.”
There was no disruption to water and sewage services in the area, he said.
“We’re continuing to work with the Environment Protection Authority to determine the impact of the spill.”
An EPA Victoria spokesperson said an estimated 23,000 litres of sewage was isolated to the Lake View Boulevard wetlands area.
“A clean up operation was commenced by South East Water.
“EPA will be making further enquiries.”
The location is bounded by a contemporary housing estate, sports fields and playgrounds.
Greater Dandenong councillor Rhonda Garad said it was “perplexing why it’s happened now and why in this place.”
The council’s acting chief executive Paul Kearsley said its emergency management team has been in daily contact with South East Water since the spill occurred.
Meanwhile, South East Water advised customers to “appropriately dispose of anything that’s not water, human waste or toilet paper, including food scraps, fats and oils”.
