glass of water
© Reuters/Tim Shaffer
A Dimock, Pennsylvania resident who did not want to be identified pours a glass of water taken from his well after the start of natural gas drilling in Dimock, Pennsylvania, March 7, 2009.

New York/Washington - Federal regulators are considering trucking fresh water to households in a Pennsylvania town where residents say wells have been polluted by hydraulic fracturing, or fracking, for natural gas.

Only a month after declaring water in Dimock safe to drink, the Environmental Protection Agency is reconsidering action after residents supplied the EPA with hundreds of pages of data that link water pollution to fracking.

Two residents of Dimock, a town of some 1,400 in the northeast corner of Pennsylvania, told Reuters that the EPA said water would be delivered on Friday, but the agency indicated it was still considering the issue.

"No decision has been made by EPA to provide alternate sources of water," an EPA spokeswoman said in an email on Friday. She added that the agency was trying to understand the situation in Dimock where state regulators recently halted deliveries of fresh water.

If the EPA delivers water to the village, it would be the clearest sign yet regulators are concerned about the effect of drilling on drinking water there.

Dimock may become pivotal in a national debate about the environmental impact of fracking, the drilling technique that could unlock decades' worth of natural gas trapped in shale deposits, but which environmentalists say contaminates water supplies.

On Thursday, the EPA said it was considering doing its own tests on drinking water there after reviewing the evidence provided by residents that suggested that water could be more polluted than they realized.

Dimock residents began complaining of cloudy, foul-smelling water in 2008 after Cabot Oil & Gas Corp began fracking, which involves injecting chemical-laced water and sand into wells to release gas in shale rock deep below the surface.

Environmentalists say fracking pollutes fresh water as fluids seep from drilling wells into aquifers and other supply sources.

Cabot had trucked water to a dozen Dimock households for three years until November when state regulators agreed it could stop. Now residents are onto the last of their water. Some are using pondwater for showers.

Cabot denies polluting local water supplies.

"We still feel very comfortable that the water meets safe drinking water standards," said Cabot spokesman George Stark. "We have a lot of data on well water there."

As fracking increases in the United States and contributes to an energy boom, the EPA is conducting a national study to determine its impacts.

A recent EPA draft report showed that harmful chemicals from fracking fluids were likely present in a Wyoming aquifer near the town of Pavillion.

Industry denies that fracking, which is being done across the country, poses a threat to drinking water.