The treatment works have generated complaints for years

The plant at Springfield near Cupar, Fife, was built in the late 1970s and has been listed as having one of the worst odour problems in the country.

Following longstanding complaints from neighbours, upgrading work has been brought forward to begin in January.

Some residents have said they do not think the �2m odour control project will totally eradicate the smells.

Concern for years

The scheme includes adding a new storm tank along with improving screening mechanisms and an interceptor tank to catch solids from a nearby piggery.

Upgrading work is expected to be completed by August.

Complaints about the smell had been received from local residents, the community council and local politicians. The issue has caused concern for several years.

Time will tell if the future improvements actually make the required difference Iain Smith MSP

Ian Dawson, who owns the nearby farm, said: "They're very overpowering. They tend to linger in the air for a long time.

"There's no disguising the fact that it's sewage. We basically have to close all the windows and doors.

There is some concern in the village that the work planned will only go part way to solving the odour problem.

Mr Dawson added: "I'll be surprised if the works that are getting done actually do get rid of the smells.

"My own opinion is that they may be targeting the wrong areas for where the smell is coming from in their plant."

Worst offenders

The Scottish Government's odour steering group found Springfield to be one of the 35 worst sites for smells.

That ranking made it a priority to curb the release of noxious odours.

Richard Blanchfield from Scottish Water said: "Not only are we looking to improve the environment and the quality of the River Eden with this multi-million pounds project, but we are also looking to alleviate the odour nuisance for people living near the works.

"We would like to take this opportunity to thank the local community for their involvement and patience while this work is carried out and to assure them that any short-term inconvenience will deliver long-term environmental benefits"

The local MSP Iain Smith has said he has been assured that the strength of the smell would be reassessed once the works were complete.

He told the BBC Scotland news website: "I welcome the news from Scottish Water that major improvements are planned for Springfield.