The U.S. Environmental Protection Agency (EPA) announced the next steps in its congressionally mandated hydraulic fracturing study, identifying seven case studies designed to help inform the assessment of potential impacts of hydraulic fracturing on drinking water resources. The sites identified were selected following input from stakeholders, including the public, local and state officials, industry, and environmental organizations. The EPA will begin field work in some of the selected regions this summer.

“This is an important part of a process that will use the best science to help us better understand the potential impacts of hydraulic fracturing on drinking water,” said Paul Anastas, Assistant Administrator for EPA’s Office of Research and Development, in a prepared statement. “We’ve met with community members, state experts, and industry and environmental leaders to choose these case studies. This is about using the best possible science to do what the American people expect the EPA to do — ensure that the health of their communities and families are protected.”

The studies, which will take place in regions across the country, will be broken into two study groups. Two of the seven sites were selected as prospective case studies where the EPA will monitor key aspects of the hydraulic fracturing process throughout the lifecycle of a well.

These areas are located in:

  • Haynesville Shale – DeSoto Parish, La.

  • Marcellus Shale – Washington County, Pa.

Five retrospective case studies were selected and will examine areas where hydraulic fracturing has occurred for any impact on drinking water resources. These are located in:

  • Bakken Shale – Kildeer, and Dunn Counties, N.D.

  • Barnett Shale – Wise and Denton Counties, Texas

  • Marcellus Shale – Bradford and Susquehanna Counties, Pa.

  • Marcellus Shale – Washington County, Pa.

  • Raton Basin – Las Animas County, Colo.

The information gathered from these case studies will be part of an approach which includes literature review, collection of data and information from states, industry and communities, laboratory work and computer modeling. The combination of these materials is intended to help the EPA do a more comprehensive assessment of the potential impacts of hydraulic fracturing on drinking water resources. The study will continue to use the best available science, independent sources of information, and will be conducted using a transparent, peer-reviewed process, to better understand any impacts associated with hydraulic fracturing.

The EPA invited stakeholders to participate in the identification of potential case studies through informational public meetings and the submission of electronic or written comments. Following thousands of comments, over 40 case studies were nominated for inclusion in the study. The case studies were identified, prioritized and selected based on a set of criteria. These criteria included proximity of population and drinking water supplies to activities, concerns about impaired water quality (retrospective only) and health and environmental impacts (retrospective only), and knowledge gaps that could be filled by the case study. Sites were prioritized based on geographic and geologic diversity, population at risk, site status (planned, active or completed), unique geological or hydrology features, characteristics of water resources, and land use.

To review the draft study plan and additional information, visit