Fracking in the US has had a “significant impact” on water supplies, particularly in dry and drought-prone areas, according to a new report.
The study by the Ceres investor network looked into the impact the practice has on water supplies, in which water and sand are injected into the ground to create fissures from which trapped gas can escape and be collected.
The report shows that of the almost 40,000 oil and gas wells drilled in the US in an 18 month period, 75 per cent of those were in areas where water is scarce, while over half were in regions already experiencing droughts.
The findings come as the UK Prime Minister David Cameron urged fracking opponents to "get on board," as he announced that local authorities who support fracking will be given more money in tax revenue.
Mr Cameron told a Commons Committee in January that opponents of fracking are "irrational" and said the practice could be "real opportunity" for Britain.
The US researchers found that 97 billion gallons of water have so far been used to extract gas since 2011.
Almost a fifth of those sites were in the dry Eagle Ford Formation in Texas, with South Texas operators using an average of 4.5 million gallons per well.
Mindy Lubber, President of the Ceres green investors' network, told The Guardian that new regulations restricting water use needed to be implemented, or else the industry could be on a “collision course” with other water users.
“Hydraulic fracturing is increasing competitive pressures for water in some of the country's most water-stressed and drought-ridden regions,” she added.
While farms and cities continue to be the main users of water, the extra demand in the Eagle Ford was affecting small, rural communities, according to the report.
It goes on to predict that the shale producers will double the amount of water they currently use in the next decade.
This combined with drought, has seen communities run out of water, with almost 15 million people in Texas already living under water rationing.
Other dry and water-stained areas of the US, including Colorado, California, New Mexico, Utah and Wyoming were also being put at risk by fracking, the report said.
The Ceres report notes that water use and sourcing are local issues, and the water use for fracking in some areas is like the straw that broke the camel's back.
Responding to the water shortages, Exxon told the Financial Times that XTO, its shale oil and gas subsidiary, “works with local authorities to ensure there is adequate supply.” It added that coal needed ten times as much water as gas produced through fracking for an equivalent energy content, and corn-based ethanol needing up to 1,000 times as much water.