CONSTRUCTION work on an old tannery site in Westbury has been delayed until developers find a way to prevent river pollution.

Persimmon Homes wants to remove an 8,000 cubic metre mound of earth at the site, known locally as Mount Everest.

The emergency planning team at county hall has already confirmed the mound contains residual chemicals including arsenic and chromium left when the tannery closed in the early 1950s, after 200 years of operation.

The Environment Agency has asked Persimmon to provide evidence that no harmful chemical substances will leak from the contaminated materials.

However, Paul Scotford from the Environment Agency said the risks were very low and Persimmon was doing everything in its power to make the area safe.

"As part of the scheme, it is digging up the contaminated waste, putting it through a treatment plant and then reburying it.

"Persimmon has set some very high standards and we just need evidence to show it can meet them and safeguard the River Biss."

Mr Scotford expects to receive some data in the next couple of weeks and, if this proves to be acceptable, the development work can continue.

He said: "If treatment methods do not meet the standards, Persimmon will have to come back with another scheme of treatment."

"The site is well fenced off from the public and in the unlikely event of something happening, an emergency response has been well planned."

Persimmon Homes wants the land for a distributor road around the Leigh Park estate.

Regional chairman David Thornton said: "Persimmon has been working closely with the agency and with West Wiltshire District Council to establish precise methods for dealing with the risk of contamination from the tannery, and to ensure there is a safe and clean environment in the long term.

"Persimmon's consultants and contractor are carrying out final tests, with work expected to commence early in the new year."