Several residents living near the Keep it Clean rendering plant on the hill above Burnside, across from Green Island, contacted the Otago Daily Times at the weekend saying it created an "unbearable'' stink.
This followed an article last week about issues the public had with a plant in North Taieri.
Both plants are owned by the Waitoa-based Wallace Group.
Kenmure resident Ian Stewart said he was driving down Kaikorai Valley Rd recently and "dry retching'' at the smell.
"It's because of the type of smell. It's that real decaying smell.''
It sometimes reached inside his property when the wind was blowing in a certain direction, he said.
"I feel for the people in Green Island and Concord. A couple of times I've gone outside and gone back inside because of it.
" I keep thinking about ringing up the air pollution guy, but it's there and it's gone.''
Another resident who lived nearby, who did not want to be named, said the plant created an "unbearable stench''.
"There have been multiple complaints and very little improvement by Keep It Clean.''
Wallace Group chief executive Graham Shortland said the company was spending "large sums of money'' addressing odour issues at both plants.
"We are working our way through a menu of things to mitigate and manage it.''
It was working closely with city and regional councils to keep them aware of the work it was doing, he said.
"I think sometimes there can be atmospheric conditions which can make matters worse, which is a slightly harder question to answer.''
The plant was about to begin "blood drying operations''.
This was "highly unlikely'' to worsen the smell, he said.
"It's a very different process.''
The company was "conscious'' of the community's concerns, Mr Shortland said.
The company had owned the plant for under a year, but he understood it was "several decades'' old.
The Otago Regional Council was unable to comment yesterday on whether it received complaints regarding the smell.
