On June 4, 2015, the U.S. Environmental Protection Agency (EPA) released a draft of its highly anticipated study, Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (the “Draft Assessment”). The study, which began at the request of Congress in 2011, contains a broad analysis of available information concerning the potential impacts of hydraulic fracturing operations on drinking water resources. While EPA identified potential mechanisms by which hydraulic fracturing could affect drinking water resources, EPA did not find evidence of widespread, systemic impacts on drinking water resources in the United States.

The study analyzed the potential impacts from hydraulic fracturing to drinking water resources, consisting of any body of groundwater or surface water that now serves, or in the future could serve, as a source of drinking water for public or private use. The study examined potential impacts during five stages of hydraulic fracturing operations:

  • Water acquisition: the withdrawal of groundwater or surface water needed for hydraulic fracturing fluids;
  • Chemical mixing: the mixing of water, chemicals and material on the well pad to create the hydraulic fracturing fluid;
  • Well injection: the injection of hydraulic fracturing fluids into the well to fracture the geologic formation;
  • Flowback and produced water: the return of injected fluid and water produced from the formation to the surface, and subsequent transport for reuse, treatment or disposal; and
  • Wastewater treatment and waste disposal: the reuse, treatment and release, or disposal of wastewater generated at the well pad, including produced water.

EPA identified above- and belowground mechanisms associated with hydraulic fracturing stages that could potentially lead to impacts to drinking water, including withdrawing water for hydraulic fracturing fluids during times of, or in locations with, low water availability; spilling hydraulic fracturing fluids and produced water; fracturing directly into underground drinking water resources; belowground migration of liquids and gases; and inadequate treatment and discharge of wastewater.

Ultimately, however, EPA found only a small number of instances in which drinking water resources were impacted when compared to the total number of hydraulically fractured wells. EPA did not find evidence that the mechanisms associated with hydraulic fracturing operations have led to widespread, systemic impacts on drinking water resources in the United States. EPA also noted that while hydraulic fracturing uses billions of water each year, with some exceptions, hydraulic fracturing water use and consumption accounts for less than 1% of the total annual water use and consumption in most areas.

EPA acknowledged that the relative absence of evidence of impacts to drinking water resources could reflect a rarity of hydraulic fracturing operations impacting drinking water resources. On the other hand, EPA pointed out that it could be due to other limiting factors, including insufficient pre- and post-fracturing data on the quality of drinking water resources; the scarcity 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 is currently accepting public comments on the Draft Assessment (Docket ID No. EPA-HQ-OA-2015-0245) for consideration by the Science Advisory Board (SAB). Beginning in September, SAB will hold three public teleconferences and three public meetings to conduct a public review of the Draft Assessment; these sessions will conclude on October 30, 2015. The final edition of the study is anticipated to be released in 2016.

Moving forward, although the relative lack of identified drinking water impacts is encouraging, given the data limitations identified in the EPA study, state and federal agencies will likely continue to seek information pertaining to hydraulic fracturing operations so as to more fully appreciate its potential impacts and to craft safeguards to protect drinking water resources.