A truck washing site has been shut down after a local resident's own investigation found polluted water running into a stream leading into the Waikato River.
Hamilton resident Owen Trolove had noticed weeds were growing in the Mangaone Stream, which runs by his home.
He followed the water upstream and eventually came across the truck washing site used by Regal Haulage on Tauwhare Rd.
Trucks which had transported fertiliser were being washed out and the dirty water was running directly into the stream, he said.
"I went up there and I though holy f******* hell. This is just a bloody mess."
He claimed there was a series of pipes at the site which may have once been designed to spread the water out over the site, but were not doing anything.
There was also a strong stench of fertiliser.
The site is owned by the Waikato District Council which has leased 8600sq m to Regal Haulage since 2002.
Trolove says he alerted an investigator from Waikato Regional Council the same day he discovered the pollution, on February 1.
Regional Council industry and infrastructure manager Brent Sinclair said an investigator visited the site the same day and discovered that a malfunction in the truck wash was causing run-off into the stream.
The regional council contacted Regal Haulage that afternoon and they agreed it would not be used until the problem was fixed.
The council is now considering what action to take over the contamination.
Sinclair said the council had not noticed a problem when it last visited the site in November 2016.
Regal Haulage director Brett McHardie said it had a "simple solution there that's worked well for a very long time" but had been damaged by local residents who used the area as a dumping site.
He said the company should have noticed the damage sooner and was now working with the council to comply.
Waikato District Council has an annual lease of $4250 plus GST with the company on the basis they met any regional council permits or consents.
The resource consent for the truck wash was issued in 2013 and is due to expire in 2023.
Waikato District Council general manager service delivery Tim Harty said the council only learnt the truck wash had been shut down on Monday.
"From a monitoring point of view, Waikato Regional Council monitors the operation of Regal Haulage. Waikato District Council's role is that of landlord."