"It's that real decaying smell.''
He couldsometimes smell it 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 local 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 the 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 atmospheric conditions can make matters worse, which is a slightly harder question to answer.''
The plant was about to begin "blood drying operations'', which was "highly unlikely'' to worsen the smell, he said.
"It's a very different process.''
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 about the smell.