The Environment Protection Authority Victoria (EPA) was notified by a member of the public after noticing the Banyule Creek in Rosanna had turned fluorescent blue yesterday.
The source of the discolouration has been traced to a dust suppressant used on the North East Link Project (NELP).
“NELP is currently working on cleaning the drain, and the EPA will oversee the project, which will now evaluate ways to prevent similar incidents in the future,” said an EPA spokesperson.
“EPA investigations and assessments of any harm to the environment are continuing.”
Sandbags have been laid at the site in an attempt to reduce the flow of the coloured substance.
A statement on the Banyule City Council’s website mentioned that the council was aware of the situation and had been informed that their drainage system was not responsible for the pollution.
“The state’s pollution regulator, EPA Victoria, has been involved in leading the investigation and response,” the statement reads.
“Council will continue to work alongside EPA to inspect downstream areas and monitor for any ongoing effects.
“We’re committed to protecting our local environment and supporting the agencies managing this incident.”
The discolouration affects the creek south of Lower Plenty Road through Creekbend Reserve.
The North East Link Project has been contacted for comment.
