Understanding EPA’s Final Report on Hydraulic Fracturing

This week, the US Environmental Protection Agency (EPA) released its final report on the impacts of hydraulic fracturing (often referred to as “fracking”) on drinking water resources in the United States. In it, the agency describes the ways in which hydraulic fracturing, wastewater management, and other activities related to oil and gas production could potentially affect drinking water resources.

Much of the subsequent commentary about this report has focused on the fact that EPA dropped language contained in an earlier (2015) draft, which stated: “We did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources in the United States.” Some in the environmental community take this shift to mean that the effects are indeed systemic, while many in the oil and gas sector note that the information is still largely anecdotal. However, much of this attention has failed to recognize that the substantive evidence contained in the report—and the state of the research upon which it is based—has changed relatively little. Thus, what we observe is a new round of messaging, rather than a reaction to new information.

To get into the details a bit, both the draft and the final report describe instances in which oil and gas activities have caused or contributed to negative impacts on drinking water resources—both above ground, such as wastewater spills and leaks, and below ground, such as problems with well integrity and impacts on local groundwater availability.

For example, both the draft and the final versions of the report discuss several US regions where hydraulic fracturing activities have taken place within or adjacent to drinking water resources. While such practices are rare, they have occurred in parts of Wyoming, Montana, and certain coalbed methane formations. Both versions of the report also discuss the research surrounding “stray gas”—cases where methane can infiltrate groundwater due to problems with well integrity.

In a shift in emphasis, the final report discusses some of these issues in greater detail, including several high-profile cases of suspected stray gas in Dimock Township, Pennsylvania; Parker County, Texas; and Pavillion, Wyoming. The final report notes that in at least two of these cases, Parker County and Pavillion, substantial uncertainty remains over the precise causes of the stray gas, in part due to a lack of baseline (pre-drilling) data.

These high profile cases, as well as less-widely publicized incidents of negative effects on drinking water from oil and gas activities, continue to be investigated by researchers at governmental, nongovernmental, and academic institutions. While the state of knowledge has continued to evolve, it has been clear for some time that there have been cases of negative impacts through a variety of pathways. However, as two of us discuss in a previous blog post, in most cases these issues have been episodic, rather than systemic in their prevalence.

In its final report, EPA chose not to use terms like “systemic,” “widespread,” or “small” in characterizing the frequency or severity of these impacts. In a webinar describing the final report, EPA noted two main reasons for changing this language. First, EPA’s Science Advisory Board recommended that the agency quantitatively support its headline conclusions, and the agency determined that data “gaps and uncertainties” prevented it from doing so. Additionally, EPA found that its draft language had not clearly communicated the findings of the report, noting that the executive summary led various stakeholder groups to interpret its conclusions in different ways.

Unfortunately, the change in report language will do nothing to help resolve the uncertainties about the systemic nature of the problems. This can only be done with more research. In fact, industry and EPA have discussed exploring these risks through a series of pre- and post-monitoring field experiments, but the parties could not come to an agreement to carry out the work. Until research like this is conducted, heat—rather than light—will continue to characterize the debate.