A GLOBAL survey states deep fracking is not a threat to water supplies in the South Downs.

The British Geological Survey states the risk of water supplies being contaminated in Britain is much lower than in the United States because almost all shale oil and gas is at least 650m below groundwater layers.

Many US homeowners have claimed that their water supply has been contaminated by methane leaks from fracked wells.

But companies in the US targeted shale less than 100m from chalk aquifers, which store water.

The distance to chalk water supply aquifers at the Weald basin in the South Downs is at least 650m.

The survey states that water supplies under the Downs should not be at risk from deep fracking, as long as vertical wells were drilled and sealed safely.

Dr Alwyn Hart, head of the air, land, and water research team at the Environment Agency, said: “We have strong regulatory controls in place to protect groundwater, and will not permit activity that threatens water and drinking supplies.”

Groundwater from the aquifers in the South Downs provide up to 70 per cent of the drinking water in the South East, making it one of the most important natural resources in the region.

Brighton Pavilion MP Caroline Lucas was among 25 people arrested at Balcombe in August 2013 during anti-fracking protests.

At court she was found not guilty of obstructing a public highway and a public order offence.

Brenda Pollack, south east campaigner for Friends of the Earth, said: “The survey is very interesting but we don’t think that it will eliminate the risk to the contamination of water.

“We believe the regulatory system is not strong enough.

“We don’t need to be trying to extract increasingly difficult fossil fuels when we need to be reducing our carbon emissions.”

A planning application for shale exploration inside the South Downs National Park is currently being considered by the South Downs National Park Authority.

A decision is expected in the next few weeks.

Simon Clydesdale, energy campaigner at Greenpeace, said: “Protective casings around drilling wells do sometimes fracture and with 30,000 wells planned in the UK can we really guarantee no water contamination?

“Water is essential to life. Playing roulette with our drinking water is a game that is too dangerous to play.”

Exploratory drilling for oil is also set to begin at Horse Hill, on the Sussex and Surrey border next month.