A five-year investigation by the U.S. Environmental Protection Agency of the boom in natural gas drilling and production has identified potentially serious threats to drinking water supplies, but provides no new detailed data that would help to quantify the scope of any contamination that has occurred across the country.
EPA media officials promoted the study as finding that “hydraulic fracturing activities have not led to widespread, systematic impacts” to drinking water. But the actual conclusion of the agency’s 998-page report contained a subtle, but important, difference: It said EPA “did not find evidence” of widespread or systematic impacts.
And authors of the EPA study made clear that they lacked enough data to draw strong conclusions about the extent of any damage.
“In particular, data limitations preclude a determination of the frequency of impacts with any certainty,” the report said.
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.
The 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.”
And when pressed, EPA officials were not able to point to any statistics listed in the study that counted or attempted to estimate instances of drinking water impacts.
“The study was not, nor was it intended to be a numerical catalog of all episodes of contamination,” EPA science advisor and deputy assistant administrator Thomas Burke told reporters during a telephone conference call.
In several key spots, the EPA report makes clear the lack of data to quantify the extent of water pollution problems related to the natural gas boom.
For example, the report says that EPA was not able to come up with nationwide data on the frequency of fracking fluid spills.
EPA used data for two states — Colorado and Pennsylvania — to generate an estimate that spills could range from 100 to 3,700 nationwide annually. But the report conceded that “it is unknown whether these spill estimates are representative of national occurrences.”
The EPA report said that investigators found no spills in which fracking fluids made it into groundwater supplies, but then noted, “the data contain few post-spill analyses, so groundwater contamination may have occurred, but have not been identified.”
Also, the EPA report bluntly explained that a lack of local water quality data needed to compare pre- and post-hydraulic fracturing conditions “reduces the ability to determine whether hydraulic fracturing affected drinking water resources in cases of alleged contamination.”
“Unfortunately there isn’t much new material here,” said Rob Jackson, a Stanford University environmental scientist who has studied drilling impacts. “EPA didn’t do any of the prospective studies they proposed four years ago or hardly any new fieldwork at all. In that sense I think they missed an opportunity.”
Industry officials, though, quickly jumped on the conclusions — as outlined in EPA’s press statements — that the report found that the gas boom wasn’t causing widespread impacts.
“I have no doubt that skeptics and deniers will pretend that EPA’s study says something it doesn’t,” said Steve Everley, a spokesman for the industry group Energy In Depth. “But this study is not just a vindication of the safety of fracking, but also good news for folks who have been inundated with alarmist –- and clearly unsupportable –- headlines for many years.”
But Amy Mall, senior policy analyst with the Natural Resources Defense Council, said that the EPA report does show impacts from fracking, despite its very limited scope.
“This study is missing some critical elements, hamstringing its comprehensiveness,” Mall said. “Among other things, there are reports industry has not cooperated in providing important information. And field studies of start-to-finish impacts never made it in. Much more science will be necessary to fully understand all of the risks. But despite the holes, it is clear EPA has found impacts — they just cannot be sure how widespread those impacts are.”
Reach Ken Ward Jr. at firstname.lastname@example.org, 304-348-1702 or follow @kenwardjr on Twitter.