CHEYENNE, Wyo. — New samples from beneath a Wyoming gas field where the U.S. Environmental Protection Agency linked hydraulic fracturing to groundwater pollution seem unlikely to sway hearts and minds on a nationwide debate over the contentious issue: The additional data just isn't a whole lot different, or more substantial, compared to what the EPA detected previously.

Calgary-based Encana, which owns the gas field in the Pavillion area in west-central Wyoming, still says the EPA research was flawed and, so too, last year's finding that implicated the petroleum industry technique.

An environmental group still says Pavillion shows more regulation is needed for fracking, the practice of blasting of millions of gallons of water and smaller amounts of sand and chemicals down well holes to force open new fissures.

“This newest information reinforces our concerns that fracking may be putting our drinking water and health at risk,” Kate Sinding, with the Natural Resources Defense Council, said Thursday.

The Pavillion field has shallow gas and geology much different from other gas fields. Fracking occurred unusually close to home water wells.