Despite statements from industry officials and political leaders, U.S. Environmental Protection Agency officials say that their new study of the nation’s natural gas boom should not be described as proof that the nation’s water supplies are safe from hydraulic fracturing.
“That is not the message of this report,” said EPA science advisor and deputy administrator Thomas A. Burke. “The message of this report is that we have identified vulnerabilities in the water system that are really important to know about and address to keep risks as low as possible.”
Burke made his comments in an interview on Friday, one day after EPA released its 998-page draft report, “Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources.”
In a follow-up statement after the interview, EPA spokeswoman Cathy Milbourn emphasized that EPA’s review of various sources of information — ranging from peer-reviewed studies to state and industry datasets — “did not identify widespread impacts on drinking water resources due to hydraulic fracturing activities.”
“The information available is adequate to qualitatively characterize the frequency of occurrence as being small, particularly relative to the number of wells that are hydraulically fractured each year,” Milbourn said in the Friday afternoon statement. “That same information, however, is not sufficient to quantitatively measure occurrence nationwide.
“We further emphasize that the purpose of the assessment was not to come up with an estimate of the frequency of occurrence for each vulnerability outlined in the assessment,” the statement said. “We do identify and make mention of specific events that serve as examples and illustrate vulnerabilities.”
When the study was released on Thursday, EPA’s press office promoted the agency’s five-year investigation as reporting that “hydraulic fracturing activities have not led to widespread, systematic impacts” to drinking water, a sound bite that was immediately picked up on by oil and gas industry officials and by political leaders who support the industry.
“EPA hydraulic fracturing review confirms safety,” said the headline on a press release from the American Petroleum Institute.
The Marcellus Shale Coalition, a regional natural gas industry group, touted the EPA report, saying it reflected “the strong, rigorous and modernized regulations in place that ensure environmental protection but also the industry’s focus and commitment to continuous operational improvements, especially related to groundwater protection and effective water management best practices.”
In its report, EPA did say its investigation had concluded that the number of “identified cases” of water impacts “was small compared to the number of hydraulically fractured wells.” But later in the report, EPA said a wide variety of “data limitations preclude a determination of the frequency of impacts with any certainty.”
Gretchen Goldman, an environmental engineer with the Center for Science and Democracy at the Union of Concerned Scientists, said EPA’s press release, along with conflicting language in the report, led to a misleading coverage in the media and likely confusion in the public about what the agency’s investigation found.
“I was just taken aback that they chose to communicate it that way, given what the results showed,” said Goldman, who wrote about the issue on her organization’s blog. “If they don’t have the data, how are they able to make those kinds of statements?”
Congress ordered the study in 2010, as natural gas production in places like the Marcellus Shale region in West Virginia skyrocketed amid the increased use of a combination of horizontal drilling and hydraulic fracturing, or “fracking.” Fracking is part of the process of preparing a well for production by pumping huge volumes of water and chemicals underground to split open rock formations to loosen oil and gas flow.
EPA investigators said that they did find “above and below ground mechanisms” through which various stages of what they called “fracking activities” can “have the potential to impact drinking water resources.”
Among those mechanisms: Fracking directly into underground water resources, water withdrawals in areas with or in times of low water availability, spills of various fluids used in or produced by fracking processes, below-ground migration of liquids and gases, and inadequate treatment and discharge of wastewater.
EPA said its investigators found “specific instances” where one or more mechanisms affected drinking water, including contamination of wells. The agency report said the number of identified cases “was small compared to the number of hydraulically fractured wells,” but conceded it wasn’t sure why.
“This finding could reflect a rarity of effects on drinking water resources, but may also be due to other limiting factors,” the EPA said. “These factors include: insufficient pre- and post-fracturing data on the quality of drinking water resources; the paucity of long-term systematic studies; the presence of other sources of contamination precluding a definitive link between hydraulic fracturing activities and an impact; and the inaccessibility of some information on hydraulic fracturing activities and potential impacts.”
EPA’s Burke said Friday that he stood by the report and that the agency did not set out to do a random sample of wells from around the country to come up with a number for the frequency of water contamination.
“What we wanted to understand were the vulnerabilities,” Burke said. “We do know that, and we feel very confident, because we looked at tens of thousands of data sources and wells’ files and spill reports that we know that the number throughout each part of the assessment is very small compared to the broader denominator of the number of wells.”
Reach Ken Ward Jr. at email@example.com, 304-348-1702 or follow @kenwardjr on Twitter.