Wollongong City Councillor Cath Blakey said it was ceramic fines from a tile roof being cleaned with a high-pressure hose.

"It is awful to see the pollution going into the stormwater drain and Byarong Creek," Cr Blakey said.

"We were fortunate that people out walking along the footpath at Byarong Creek raised the alarm and reported it to council straight away.

Read more: South32 report says creek pollution 'non-toxic'

"Council rangers were onsite quickly and have been able to trace the pollutant through the stormwater drain system to the source, and are pursuing compliance action."

Figtree resident Charlotte Simpson said she was concerned for wildlife.

"There's an abundance of ducks, frogs and eels in the creek," she said.

"I am still trying to locate three ducklings which lived in the area where the pollution occurred."

A spokeswoman for the council, however, said WCC couldn't yet confirm what the substance was.

"The incident is currently under investigation and the red discharge to the creek will be confirmed through this process," she said.

In August the nearby Brandy and Water Creek was contaminated by an estimated 10 megalitres of water containing coal waste which was washed down from a stormwater drain at South32's Dendrobium mine.

"Many residents have expressed dismay at seeing their local way so heavily polluted," Cr Blakey said.

"All stormwater drains lead to local creeks and eventually the sea. Byarong Creek flows through Figtree into American Creek, then Allans Creek and eventually Tom Thumb Lagoon also known as Port Kembla Harbour. We need to stop pollution from the source to the sea."

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