Villagers angry about the odour of rotting food from a compost waste centre are to stage a protest.
People in Gelligaer, Penybryn and Nelson in Caerphilly county say the smell from the Bryn Compost site means they cannot open windows in summer.
They hope to force the firm to take action with the protest at Greenhill School, Gelligaer, on Wednesday.
Bryn Compost says it is working with the Environment Agency to improve the situation.
Ray Matthews from Gelligaer, who sits on a liaison committee set up by Caerphilly council to address the issue, said residents were also worried about the potential health risks connected with inhaling the odours.
He said: "Most people here are pro-recycling but when it comes to health and quality of life, this is the wrong place for this site.
"We have been suffering from bad odours coming from Bryn Compost for four years but over the last two years it has become absolutely disgusting."
'Eliminate the odour'
A spokesperson for Bryn Compost said the site posed no danger to people's health and it had taken various measures to address the issue.
"We recognise there is sometimes an odour at the site and we have been working closely with the Environment Agency to improve the situation," said the spokesperson.
"We are entirely committed to running the site as best we can and to eliminate the odour."
Bryn Compost has lodged a planning application with Caerphilly council to enclose its operations inside a building and compost in a different way.
The spokesperson added: "We are confident this is the long-term and robust solution and we hope the application will be determined by the council within the next few months."
The protest takes place outside Greenhill School, Gelligaer, at 1000 BST on Wednesday.