A proposed travellers’ site could put Brighton’s water supply at risk of pollution, an expert has claimed.

A formal planning application for the Horsdean site, which has been awarded a £1.7million Government grant, is expected in the next month.

But a community group including former Brighton University researcher James Rhodes has cast serious doubt on the suitability of the site. He said it is situated in a floodprone basin and that polluted water could seep through the limestone into the groundwater supply within 24 hours.

Dr Rhodes said: “The concept of locating a traveller camp in such a vulnerable position appears to be complete folly and against all common sense, and could well compromise a major water source.

“This site is quite unsuitable as a place for travellers to live, or anybody else for that matter, and should be returned to its original use as a recreational ground.”

The retired lecturer added: “Instead of wasting public money trying to find ways around all the difficulties, time and energy would have been much better spent in searching for a location that properly meets the demand without endangering the supply.”

The site was selected by Brighton and Hove City Council as the best option for a travellers’ site in 2011.

It has been used as a transit site for several years but is currently closed for maintenance.

A planning application for a permanent site will be submitted in the next month to the South Downs National Park Authority.

A council spokesperson said: “We are very aware of the sensitivity of the Horsdean location in ground water terms and have been in contact with the Environment Agency from very early on in the site selection process. We have employed specialist hydrology consultants to assess the issues and to design a scheme that will be acceptable and prevent groundwater contamination.”

An Environment Agency spokesperson said: “As part of the preplanning process, we have provided comments on foul and surface water assessments for this site.

“Due to the groundwater sensitivity of this site, we will continue to work with the consultants to ensure these strategies satisfy our requirements prior to the formal submission of a planning application.”

The Patcham and Hollingbury Conservation Association has been campaigning against the plan.