A resident reported it on Thursday afternoon and within an hour Wollongong City Council staff were on the scene to try and clean up.
At the scene on Friday morning Councillor Cath Blakey urged anyone with information to report it, so the culprit could be found.
"It's disgusting to see one of our local waterways being used to dump chemical waste," Cr Blakey told the Mercury.
"I'm really heartened though that someone reported it quickly and that council took quick action putting in a bund, trying to contain the pollutant, getting samples, and pumping some of it out.
"It's really important that if anyone knows anything they contact council or the EPA, so we can find out who's responsible, and not only take compliance action but also to get them actually to fund the recovery work."
Cr Blakey pointed out lizards and fish that were in and around the waterway, which was sustaining life despite running through an industrial area into Fairy Creek.
"I was contacted by a resident who's actually done some birding here and talked about seeing different birdlife ... we can see now there's fish and there's water dragons.
"So it's really terrible that someone has dumped this pollution into the creek.