US environmental authorities have declared for the first time that fracking may be to blame for groundwater pollution.

A draft finding by the U.S. Environmental Protection Agency (EPA) could have a chilling effect on states trying to determine how to regulate the process.

Fracking, or hydraulic fracturing, involves pumping pressurised water, sand and chemicals underground to open fissures and improve the flow of oil or gas to the surface.

The EPA found that compounds likely associated with fracking chemicals had been detected in the groundwater beneath the Wyoming community of Pavillion where residents say their well water reeks of chemicals.

Health officials advised them not to drink their water after the EPA found hydrocarbons in their wells.

The EPA announcement has major implications for the vast increase in gas drilling in the US in recent years. Fracking has played a large role in opening up many reserves.

The industry has long contended that fracking is safe, but environmentalists and some residents who live near drilling sites say it has poisoned groundwater.

The EPA said its announcement is the first step in a process of opening up its findings for review by the public and other scientists.

“EPA’s highest priority remains ensuring that Pavillion residents have access to safe drinking water,” said Jim Martin, EPA regional administrator in Denver. “We look forward to having these findings in the draft report informed by a transparent and public review process.”

At this time, the EPA is emphasising that the findings are specific to the Pavillion area. The agency said the fracking that occurred in Pavillion differed from fracking methods used elsewhere in regions with different geological characteristics.  Further studies need to be done in specific areas and the finding of this report should not be extrapolated to other areas of high activity.

This feels a bit like the EPA is hedging their bets and is scant consolation to those folks in other parts of the country who have the sideshow ability to light their water taps on fire.  Nevertheless, this finding may make it easier for other communities to have their voices heard when they express concerns about pollution of their water supplies.  This will be particularly important in Texas which is looking at a multi-year, record breaking drought in their future.

The fracking occurred below the level of the drinking water aquifer and close to water wells, the EPA said. Elsewhere, drilling is more remote and fracking occurs much deeper than the level of groundwater that anybody would use.

In Colorado, regulators are considering requiring oil and gas companies to publicly disclose the chemicals used in fracking

The public and industry representatives packed an 11-hour hearing on the issue on Monday. They all generally supported the proposal but the sticking point is whether trade secrets would have to be disclosed and how quickly the information would have be turned over.

Industry representatives say Colorado and Texas are the only states to have moved to consider disclosing all fracking chemicals, not just those considered hazardous by workplace regulators.