A poultry firm yesterday moved to reassure residents of a Norfolk village over the size and health risks of a half-built rendering plant near their homes.

A poultry firm yesterday moved to reassure residents of a Norfolk village over the size and health risks of a half-built rendering plant near their homes.

Attleborough-based Banham Poultry has faced strong opposition over its plans at Clay Hall Farm, Great Witchingham.

Villagers claim the plant being built is bigger than it has permission for and have voiced concerns that it could process carcasses of animals with notifiable diseases such as avian flu.

But bosses at the Banham Compost, part of Banham Poultry, say the worst it intends to process is low-risk diseased poultry, relating to common conditions such as enteritis.

The company says it is building a single-unit rendering plant that was approved in 2003 and has submitted a planning application to Norfolk County Council for a twin-unit plant, processing the same material and of the same size.

It says the twin-unit plant became necessary after Defra introduced new guidelines last year banning different grades of material from being processed in the same building.

But objectors have requested the government "call-in" the planning application and this week the director of planning at the county council, Mike Jackson, confirmed the company is carrying out building work that it does not have permission for on the site.

Bob Waterson, the project manager at Banham, insisted the only deviation from the approved plan on site was that a second intake pit had been dug, which will be filled if requested by the county council.

He said if it took too long to get the two units approved the company would instead complete the single building and only process one type of waste material.

Mr Waterson said the twin-unit plant was identical to the approved single-building plant apart from the fact that it would have two intakes and outputs, which would mean a small section of the roof was two panels higher.

He added it would be a vast improvement over the Mid Norfolk Proteins rendering plant that ran on site until 2003.

"People would see a very modern building, they will have none of the odour problems they have had previously and that, bar a small amendment, conforms to an existing planning consent," he said.

When it is finished it will be the only rendering plant in East Anglia, processing 1,500 tonnes of animal waste material each week.

The twin unit plant will be able to handle two types of material, that fit for consumption such as offal from healthy chickens while the higher risk material could be chickens that die from disease, culled birds or those that die for other reasons before being slaughtered.

Mr Waterson added the only way it would be used for processing waste such as birds that have died from avian flu would be if it was forced to accept the carcasses by Defra, something he said was highly unlikely.

The building will be fitted with a high-tech biofilter and oxidiser that will remove all odours from the air before it is pumped out of the plant and is expected to be served by about 25-lorries a day.

The earliest planning meeting the twin-plant plan could be considered by Norfolk County Council would be on April 27.

Mr Jackson has said the county council is considering whether to take enforcement action over unauthorised building work carried out by Banham and is continuing to monitor the site.