The rubbish is strewn around a former gravel-dredging area by the Clutha River, off Barnego Rd on the outskirts of Balclutha.
A Balclutha man, who wanted to remain anonymous, said he came across the illegal dump in February and contacted the Clutha District Council with his concerns. He said he was then told to contact the Otago Regional Council (ORC).
When the Otago Daily Times first visited the site early last month there was a washing machine, five containers labelled as agricultural products, sheep remains, and household waste among the rubbish dumped on gravel and in the grass.
By yesterday morning the rubbish had doubled, with 10 containers labelled as agricultural products, a mattress, and more household waste.
Most of the containers are filled with a milky-looking substance.
Since then, other Balclutha residents have contacted the ODT about their concerns.
One woman said it was a long-standing issue and she had come across similar dumping two years ago.
''It's just shocking what they're dumping.''
The area, a few metres away from the Clutha River, is a marked angler's access area and a popular spot for walkers. Clutha District Council planning and environment manager Murray Brass said the Litter Act made it illegal for anyone to deposit rubbish of any kind on to land without approval of the landowner.
According to the council records, the land was a mix of riverbed and Crown land, he said.
The council had contacted the ORC, as riverbed fell under its jurisdiction.
Mr Brass said he had visited the site and saw containers labelled as drenches.
''If the liquid matches what is on the labels then they are chemicals, but not an immediate risk.''
ORC environmental services manager Martin King said if the illegal dump site was in an area classified as riverbed, then it did fall under the regional council's responsibilities.
Staff would visit the area this week, he said.
Mr King said illegal dumping in riverbeds was an issue throughout the region, but did not occur regularly.
In 2008, the Clutha District Council introduced a new bylaw with a two-tier infringement system, for those caught littering. Small to medium cases of littering can result in instant fines of either $100 or $400, while major cases go before the courts. The council successfully prosecuted a man in 2008 for dumping rubbish near Clinton. He was convicted and fined $1000 and ordered to pay $101 reparation after dumping a trailer-load of rubbish at a layby in September 2007.
Mr Brass asked the public to report vehicle registrations or other identifying details if people were suspected of illegally dumping rubbish.
