"Advocates state that fracturing has been performed safely without significant incident for over 60 years," the report said. "Opponents point to failures and accidents and other environmental impacts, but these incidents are typically unrelated to hydraulic fracturing per se and sometimes lack supporting data about the relationship of shale gas development to incidence and consequences."

Panel members blamed some of this "difference in perception" on "communication issues."

"Many in the concerned public use the word 'fracking' to describe all activities associated with shale gas development," the report said, "rather than just the hydraulic fracturing process itself."

The report noted that the U.S. Environmental Protection Agency is undertaking a two-year study -- ordered by Congress -- to investigate the potential impacts of hydraulic fracturing on drinking water resources.

The advisory panel report said, "The subcommittee shares the prevailing view that the risk of fracturing fluid leakage into drinking water sources through factures made in deep shale reservoirs is remote."

"Regulators and geophysical experts agree that the likelihood of properly injected fracturing fluid reaching drinking water through fractures is remote where there is a large depth separation between drinking water resources and the producing zone," the report said. "In the great majority of regions where shale gas is being produced, such separation exists and there are few, if any, documented examples of such migration."

But the panel also said, "An improperly executed fracturing fluid injection can, of course, lead to surface spills and leakage into surrounding shallow drinking water formations. Similarly, a well with poorly cemented casing could potentially leak, regardless of whether the well has been hydraulically fractured."

The report said, though, that methane leaking from producing wells into surrounding drinking water wells "is a greater source of concern," that needs more study and more attention from the industry.

Panel members said such methane migration could most likely be blamed on drilling in a geologically unstable location or on poor casing or production practices.

More testing and more frequent inspections are needed to guard against such unsafe practices, the panel said.

"The public deserves assurance that the full economic, environmental and energy security benefits of shale gas development will be realized without sacrificing public health, environmental protection and safety," the report said. "Accidents and incidents have occurred with shale gas development, and uncertainties about impacts need to be quantified and clarified."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.

Read the report

The U.S. Department of Energy advisory panel downplayed the chances that large-scale "fracking" to release gas reserves deep underground would directly pollute drinking water from shallow groundwater supplies.

But the team also warned shoddy industry practices such as poorly cemented well casings could easily leak contaminants and urged a broader examination of the overall impacts of gas booms like the one hitting West Virginia's Marcellus Shale formation.

"Intensive shale gas development can potentially have serious impacts on public health, the environment and quality of life -- even when individual operators conduct their activities in ways that meet and exceed regulatory requirements," said the 41-page report from a Secretary of Energy Advisory Board subcommittee appointed by Energy Secretary Steven Chu.

"The combination of impacts from multiple drilling and production operations, support infrastructure (pipelines, road networks, etc.) and related activities can overwhelm ecosystems and communities," the report said.

Panel members urged federal, state and local regulators to "place greater effort on examining these cumulative impacts in a more holistic manner."

"Discrete permitting activity that focuses narrowly on individual activities does not reach to these issues," the report said.

The report's findings are significant in part because six of the panel's seven members have financial ties to the gas industry, including chairman John Deutch, an MIT chemist and former CIA director who previously served on the boards of two energy companies. On Wednesday, 28 scientists from 22 universities in 13 states had urged Chu to appoint a new chair to ensure the group's work was "unbiased and scientifically sound."

"The committee appears to be performing advocacy-based science and seems to have already concluded that hydraulic fracturing is safe," the scientists said in their letter. "We believe that the best science should be done first to determine whether increased unconventional gas production is sufficiently safe -- from the individual water well to climate impact -- and that policy should follow."

In its report, the panel called natural gas "the cornerstone of the U.S. economy," and praised "breakthroughs in technology" that have "brought lower prices, domestic jobs and the prospect of enhanced national security due to the potential of substantial production growth."

And parts of the report echoed industry complaints that drilling critics and the media misstate the impacts of the gas boom, especially regarding larger-scale hydraulic fracturing.

"Advocates state that fracturing has been performed safely without significant incident for over 60 years," the report said. "Opponents point to failures and accidents and other environmental impacts, but these incidents are typically unrelated to hydraulic fracturing per se and sometimes lack supporting data about the relationship of shale gas development to incidence and consequences."

Panel members blamed some of this "difference in perception" on "communication issues."

"Many in the concerned public use the word 'fracking' to describe all activities associated with shale gas development," the report said, "rather than just the hydraulic fracturing process itself."

The report noted that the U.S. Environmental Protection Agency is undertaking a two-year study -- ordered by Congress -- to investigate the potential impacts of hydraulic fracturing on drinking water resources.

The advisory panel report said, "The subcommittee shares the prevailing view that the risk of fracturing fluid leakage into drinking water sources through factures made in deep shale reservoirs is remote."

"Regulators and geophysical experts agree that the likelihood of properly injected fracturing fluid reaching drinking water through fractures is remote where there is a large depth separation between drinking water resources and the producing zone," the report said. "In the great majority of regions where shale gas is being produced, such separation exists and there are few, if any, documented examples of such migration."

But the panel also said, "An improperly executed fracturing fluid injection can, of course, lead to surface spills and leakage into surrounding shallow drinking water formations. Similarly, a well with poorly cemented casing could potentially leak, regardless of whether the well has been hydraulically fractured."

The report said, though, that methane leaking from producing wells into surrounding drinking water wells "is a greater source of concern," that needs more study and more attention from the industry.

Panel members said such methane migration could most likely be blamed on drilling in a geologically unstable location or on poor casing or production practices.

More testing and more frequent inspections are needed to guard against such unsafe practices, the panel said.

"The public deserves assurance that the full economic, environmental and energy security benefits of shale gas development will be realized without sacrificing public health, environmental protection and safety," the report said. "Accidents and incidents have occurred with shale gas development, and uncertainties about impacts need to be quantified and clarified."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.