Jump to main content or area navigation.

Contact Us

Water: Hydraulic Fracturing

Case Study Locations for Hydraulic Fracturing Study

EPA has selected seven case studies located in various formations locations across the country that the Agency believes will provide the most useful information about the potential impacts of hydraulic fracturing on drinking water resources under a variety of circumstances. Two prospective case studies, where EPA will monitor key aspects of the hydraulic fracturing process at future hydraulic fracturing sites, are located in:

  • Haynesville Shale - DeSoto Parish, LA
  • Marcellus Shale - Washington County, PA

Our partners in conducting the prospective case studies are Chesapeake Energy Corporation in DeSoto Parish, LA and Range Resources Corporation in Washington County, PA.

Five retrospective case studies, which will investigate reported  drinking water contamination due to hydraulic fracturing operations at existing sites, are located in:

Key Issues to be Investigated

Potential Outcomes

new Companies Involved

Bakken Shale—Killdeer and Dunn Counties, ND

  • Production well failure during hydraulic fracturing
  • Suspected drinking water aquifer contamination
  • Identify sources of well failure
  • Determine if drinking water resources are contaminated and to what extent
  • Denbury Resources Inc.

Barnett Shale—Wise County, TX

  • Possible drinking water well contamination
  • Spills and runoff leading to suspected drinking water well contamination
  • Determine if private water wells are contaminated
  • Obtain information about the likelihood of transport of contaminants via spills, leaks, and runoff
  • Aruba Petroleum, Inc.
  • Primexx Energy Partners Ltd
  • XR-5, LLC
  • White Stone Energy, LLC

Marcellus Shale—Bradford and Susquehanna Counties, PA

  • Ground water and drinking water well contamination
  • Suspected surface water contamination from a spill of fracturing fluids
  • Methane contamination of multiple drinking water wells
  • Determine if drinking water wells are contaminated
  • Determine source of methane in private wells
  • Transferable results due to common types of impacts
  • Chesapeake Energy Corporation
  • Cabot Oil and Gas Corporation
  • Chief Oil and Gas, LLC

Marcellus Shale—Washington County, PA

  • Changes in drinking water quality, suspected contamination
  • Stray gas in wells, surface spills
  • Determine if drinking water wells are contaminated
  • Determine if surface spills affect surface and ground water
  • If contamination exists, determine potential source of contaminants in drinking water
  • Range Resources Corporation
  • Atlas Energy, L.P.

Raton Basin, CO

  • Potential drinking water well contamination (methane and other contaminants) in an area with intense concentration of gas wells in shallow surficial aquifer (coalbed methane)
  • Determine source of methane
  • Identify presence/source of contamination in drinking water wells
  • Pioneer Natural Resources Company
  • Petroglyph Energy, Inc.


Criteria for Case Study Location Selection

The sites were identified, prioritized and selected based on a rigorous set of criteria and represent a wide range of conditions and impacts that may result from hydraulic fracturing activities. These criteria included proximity of population and drinking water supplies, evidence of impaired water quality (retrospective only), health and environmental concerns (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 hydrological features, characteristics of water resources, and land use.

Jump to main content.