EPA’s Fracking and Drinking Water Study: A Win for Science, but More Work Remains

In a triumph of science over drilling industry spin, the U.S. Environmental Protection Agency on December 13 issued its final report on the impact of hydraulic fracturing or “fracking” on drinking water supplies, finding that the oil and natural gas extraction technique had caused or contributed to drinking water impacts in a variety of ways.  Importantly, EPA removed an unsubstantiated claim featured in an earlier draft in which the agency contended that the impacts were relatively rare.

However, significant data gaps and EPA’s exclusion of likely pollution pathways in the study’s design mean that citizens and policy makers should treat the report as informative but not comprehensive despite its length (666 pages plus 572 pages of appendices).  Two significant potential routes of pollution not included in the study are the drilling of wells, a prerequisite to fracking that often involves boring directly through underground water supplies with chemicals, and the underground injection of fracking wastewater for disposal, the predominant method of wastewater disposal.

The EPA presented evidence that hydraulic fracturing had caused or contributed to impacts on water supplies through several routes:  improperly cemented wells (Bainbridge, Ohio (p. 6-71); Mamm Creek, Colo.(p. 6-72)), spills of produced water (Pennsylvania and Williams County, N.D.(p. 7-26)), well blowouts (Killdeer, N.D.(6-21)), overflow of wastewater retention pits (Knox County, Ky.(8-43)), seepage of wastewater from unlined pits into water supplies (Ohio, Texas, Wyoming (8-44 through 8-45)).

The agency also concluded that there are activities that are “more likely than others to result in more frequent or more severe impacts including:

“Water withdrawals for hydraulic fracturing in times or areas of low water availability, particularly in areas with limited or declining groundwater resources;

“Spills during the management of hydraulic fracturing fluids and chemicals or produced water that result in large volumes or high concentrations of chemicals reaching groundwater resources;

“Injection of hydraulic fracturing fluids into wells with inadequate mechanical integrity, allowing gases or liquids to move to groundwater resources;

“Injection of hydraulic fracturing fluids directly into groundwater resources;

“Discharge of inadequately treated hydraulic fracturing wastewater to surface water resources; and

“Disposal or storage of hydraulic fracturing wastewater in unlined pits, resulting in contamination of groundwater resources.” (pp. ES-46 through ES-47)

The EPA acknowledged that data gaps prevented an assessment of the nationwide frequency of impacts on drinking water from fracking (p. ES-46).  This finding was a significant change from the draft report issued in June 2015.  The executive summary of that previous document stated that EPA “did not find evidence” that fracking caused “widespread, systemic impacts on drinking water resources.”  The accompanying news release contained an even more sweeping statement that “hydraulic fracturing activities have not led to widespread, systemic impacts on drinking water resources.”

The EPA’s Science Advisory Board criticized the finding as inconsistent with the body of the 1,000-page draft report that highlighted multiple data gaps that should have prevented the EPA from making broad conclusions.  PFPI and other organizations had expressed similar concerns in comments to the science advisory board.  Marketplace and American Public Media recently reported that the line about “widespread, systemic impacts” was added to the draft report in the final six weeks of a five-year long process and that the line was added to the EPA’s news release one day before release.  As PFPI stated recently, these changes created the appearance that the Obama administration manipulated the report to downplay drilling risks and shield the oil and gas industry from regulation.  EPA’s removal of the line in the final report was a significant improvement.

The final study could have been further improved if it had included analyses of pollution from the drilling of wells and disposal of wastewater by reinjecting it underground.  The EPA found that “most hydraulic fracturing wastewater is managed by injection into…disposal wells” (p. 8-1) and cited one estimate that in 2012, onshore and offshore U.S. oil and gas producers generated close to a trillion gallons of wastewater, an estimate that the EPA noted may be too low (p. 8-6).  The agency also found that such wastewater can contain dangerous substances including the known human carcinogen, benzene (p. 8-65).  In 1989, Congress’ investigative arm, the Government Accountability Office (then the General Accounting Office) found severe water pollution caused by this disposal method.  The federal government has not conducted a significant investigation of water pollution related to the process since.

Due to lack of cooperation by the drilling industry, the report did not contain so-called prospective studies that would have compared baseline water samples prior to hydraulic fracturing with samples of the same water sources after fracturing had occurred.  These studies are perhaps the best way to assess fracking’s impacts.  It is disappointing that the EPA has not been able to conduct such studies since concluding in a 1987 report to Congress (see p. IV-22) that “during the fracturing process, fractures can be produced, allowing migration of native brine, fracturing fluid, and hydrocarbons from the oil and gas well to a nearby water well.  When this happens, the water well can be permanently damaged and a new well must be drilled or an alternative source of drinking water found.”  This finding was featured in a 2011 New York Times series on natural gas drilling.

The EPA acknowledged many other data gaps that hampered the study including two that PFPI highlighted in a recent report:  drilling industry trade secret claims that hide the identity of chemicals used in hydraulic fracturing (pp. 5-19 through 5-20) and the lack of toxicological data for these chemicals (p. 9-8).

The EPA’s study is a valuable document, but in the years ahead, the EPA still has much work to do to protect the public from fracking’s impacts.