Environmentalists have criticised revised plans for a controversial biogas plant in the Norfolk countryside.

The anaerobic digester (AD) is being built in Bressingham, near Diss, but late last year the companies behind it had to submit new proposals to South Norfolk Council, following complaints that the project had deviated from the conditions of its original planning permission.

Now, South Norfolk Green Party have attacked the new plans, branding them "greenwashing" and questioning the environmental benefits of the scheme.

Their supporters say that anaerobic digesters - which produce fuels from materials like maize or manure - are environmentally friendly because they generate energy from waste materials. But critics have questioned this, claiming they can generate pollution.

Tom Williamson of the South Norfolk Green Party branded the Bressingham plans "greenwashing", saying they were being pushed through under the guise of being a benefit to the community.

Of particular concern to Mr Williamson are new digest lagoons, which turn organic materials into methane and carbon dioxide.

Mr Williamson said: "No such lagoons were included in the original plan, this is a major alteration.

"So that everyone can visualise the size of the actual lagoons, each one would be two thirds the size of Norwich City Carrow Road pitch."

Three lagoons are included in the plans, with a capacity of 5,000 square metres of liquid digestate each.

Mr Williamson also complained one of the lagoons, which will all be raised above ground level, will be close to Bressingham village and a public footpath.

He said: "The lagoons are to be fed by pipelines from the digester which on the plans provided follow the roadside presumably located in ditches so any spill will immediately cause environmental damage."

He added that there were environmental concerns over using green liquid manure in the process, which can leak into nearby watercourses and pollute land with an increase in potassium and nitrate.

The AD was first approved in 2015 but as construction got underway neighbours complained the plans were changed without permission.

This came to a head in October 2021, when Tim Barker, SNC planning officer, questioned the legality of the development and called for it to be stopped and a new planning application to be submitted. Development finally stopped in November.

A spokeswoman for Deal Farm Biogas Limited, one of the companies behind the project, said the new part retrospective planning application had been submitted to validate changes from the 2015 permission.

She said: "The changes predominantly include amendments to the layout and positioning of equipment on the site, but critically, the application seeks to further enhance the sustainability of the plant by including carbon capture technology."

She encouraged anyone with questions to visit www.dealfarmbiogas.co.uk for more information on the project.