A major operation to remove 7,500 tonnes of contaminated soil from a section of north Suffolk marshes is to be launched following a public outcry.

A major operation to remove 7,500 tonnes of contaminated soil from a section of north Suffolk marshes is to be launched after a public outcry.

The Environment Agency (EA) has agreed to take drastic action after admitting its contractors dumped the soil, contaminated with destructive Japanese Knotweed, on Reydon Marshes, near Southwold.

As reported in the EDP last month, furious landowners feared the fast-spreading weed, the planting of which is an offence under the Wildlife and Countryside Act 1981, would cause havoc on the marshes and surrounding area.

Initially, it appeared the EA would leave the contaminated soil, brought in to construct a flood defence bank, on site and carry out a treatment programme to stop it spreading.

However, a spokesman last night confirmed the huge task or removing the soil from the site would now take place, although he was unable to say how much the project would cost.

Richard Woollard said: "We will be removing it, but that's all we can say at this stage. The soil needs to be carefully disposed of using the proper authorities."

While the removal of the soil has been demanded by landowners, their representative fears the action might not be enough to prevent knotweed taking root and spreading in the long-term.

Sam Jennings, who works for land agents Strutt and Parker in Ipswich, said his clients wanted a long-term commitment from the EA to treat any future outbreaks of the weed in the area.

Mr Jennings, who represents clients including Southwold Town Council, St Felix School and Southwold Fishing Club, added: "Even though they are going to remove the soil, I don't think it's the end of the problems. How do they know it will remove everything?"

Landowners had threatened the EA with legal action if it did not remove the soil while it also emerged the EA, which usually investigates breaches of environmental law, faced the possibility of prosecution itself.

Mr Jennings added: "If knotweed suddenly appeared on land belonging to the town council or the fishing club, the Environment Agency would come down on them like a tonne of bricks, with enforcement notices. In five to 10 years' time everyone will have forgotten what has happened now."

Resident Clyde Camburn, who lives by the marshes, said: "I think it is good news. It's what we wanted, but they need to ensure there are procedures in place to manage the potential spread of knotweed. It's very easy for the stuff to spread and I'm anxious to make sure they don't just remove it and walk away."

Japanese Knotweed was introduced to the UK as an ornamental plant during the 1800s and forms dense clumps up to three metres in height. It shades out native plants by producing a dense canopy of leaves and creates a poor habitat for native birds, insects and mammals. It can also grow through roads and within cavity walls in properties.

A spokesman for the Government-funded watchdog Natural England last night said there were no plans to at present to carry out a prosecution.

No-one from the EA's contractors, Van Oord, was available for comment.