Oil and diesel are allegedly being discharged into a South Auckland waterway, leaving a nasty smell and killing eels.
"I live in the house next door and we can't even open our windows", says local Ben Watson, who’s fed up.
"Over the last 3-5 months we've been noticing oil and diesel coming down and it's just been getting stronger and stronger", he said.
"The smell is just horrible, makes our mouths feel like we may as well be drinking it", said another local, Shane Vegar.
Mr Watson says he’s traced the oil slick and stench up the creek, to the company he believes is responsible.
He's reported it to Auckland Council, but says not enough has been done.
"[The Council's] responded, and they've actually told us themselves that it's bad, but then nothing seems to happen", Mr Watson said.
Two days ago, he turned to Facebook in frustration, his post gaining plenty of attention.
"We got a lot of response from that and I think that's what's got everyone starting to do something about it now", said Mr Vegar.
Then today, to add to the pollution, a 44 gallon drum of oil was tipped on its side over a drain just 50 metres from the stream.
"All my workers turn up for work and we come out here and they like to chuck bread to the eels", Mr Watson said.
"As we were doing that a whole lot of black oil started coming out of the drain"
"Thankfully the Council turned up about 10 minutes after, so they witnessed that."
Council compliance staff have spent the day cleaning up.
As part of that blockages called booms have been placed in the creek and a truck with specialist suction equipment was also dispatched.
Auckland Council's Regulatory Services Director Craig Hobbs also said: "Compliance officers have been in contact with a company in Papakura that has been allegedly dumping oil in the Slippery Creek since 2017"
"They received an abatement notice and fine for discharging oil in August 2018.
"A further alleged spill in May 2019 is currently under investigation."
Mr Hobbs said the council is unsure if today’s oil drum spill was related to the company, but it is making inquiries.
Locals told 1 NEWS they just want the pollution to be stopped.
"It's disgusting, it really is", said Mr Vegar.
"I don't see why people have to dump in the water you know, it goes to our oceans, it's where we fish", he said.
The council's warning it's taking its investigation seriously.
"There are significant penalties in place for those issues occurring, there's a $300,000 fine for an individual, $600,000 fine for a corporate, two years in prison" Mr Hobbs said.
The Council is also urging anyone who sees a person or company illegally dumping chemicals to call its pollution hotline on 09 377 3107.