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

Natural gas plays a key role in the nation’s energy future. EPA is working closely with other federal partners to ensure that this important resource can be developed safely.

“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,” says Paul Anastas, assistant administrator for EPA’s Office of Research and Development. “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 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 allow a more comprehensive assessment of the potential impacts of hydraulic fracturing on drinking water resources. Using independent sources of information, the study will be conducted using a transparent, peer-reviewed process to better understand any impacts associated with hydraulic fracturing.

EPA invited stakeholders from across the country 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, more than 40 case studies were nominated for inclusion in the study. The case studies were identified, prioritized and selected based on criteria that 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 view the draft study plan and additional information, visit