Pavillion, Wy
Jeff Locker, a Wyoming farmer, displays water filters from his well on September 17, 2009. Reuters

The U.S. Environmental Protection Agency is again under fire for a draft study released late last year that suggests natural gas drilling contaminated ground water.

An independent review of the EPA's controversial draft study on hydraulic fracturing in Wyoming concluded federal regulators had insufficient data to suggest the natural gas drilling technique allowed methane to contaminate groundwater, near the town of Pavillion.

The EPA is still reviewing its Dec. 8 draft study, which drew sharp criticism from industry proponents. In early March, the agency agreed to have more water samples taken, and even delayed the peer review process needed to corroborate its findings.

The U.S. Geological Survey in April collected additional samples from the town and will expect to have results ready by September, said its spokesman, Dave Ozman.

But according to a report initially released this week by S.S. Papadopulos & Associates Inc., an environmental and water resource consulting firm, the EPA's study did not adequately distinguish between potential natural impacts and those from gas drilling activities.

The EPA has previously said its findings in Pavillion are unique to that single town, and should not be used to assume hydraulic fracturing, or fracking, everywhere is causing groundwater contamination. But the study's findings, if eventually upheld, would be the first time that drilling for natural gas itself contaminated water from underground aquifers -- potentially validating the fears of many, who are convinced the technique is hazardous.

Fracking involves pumping large amounts of water mixed with sand and toxic chemicals to fracture underground rock formations and collect natural gas trapped within them.

The EPA draft study found evidence of natural gas deep in water wells regulators drilled for the purpose of conducting their investigation, but the Papadopulos study faults the EPA's report on several fronts.

It finds the EPA lacked baseline and background data including naturally occurring methane and other hydrocarbon levels, faulted poor study design, found the EPA's conclusions are based on a total of four samples, and that the EPA study failed to adequately address the original project aims of determining the source of taste and odor complaints in residential wells.

The EPA launched its investigation following residents' complaints that their water quality had visibly deteriorated after natural gas drilling took place in the area.

For the EPA to adequately test their hypothesis that deep groundwater in the Pavillion area is impacted by hydraulic fracturing activities, additional samplings [of wells] is required, read the report.

This latest assessment of the EPA's report has added to criticism of the agency following its study's release in December.

Encana Corp., the oil company drilling in the area, blasted the report as soon as it came out, and the Independent Petroleum Association of America joined in on Wednesday.

Through this review, the science speaks for itself, said Lee Fuller, IPAA vice president of government relations. Unfortunately, the EPA has continued to miss the mark with its draft report. We encourage EPA to work with the State of Wyoming and the U.S. Geological Survey, among other stakeholders, to re-examine the two EPA monitoring wells for their suitability to this study's objectives and to credibly investigate likely sources of potential constituents of concern while adopting strict scientific standards and avoiding guesswork.

It is our hope that this study's flaws will challenge and guide the agency toward better methodology and reporting in the future.