EPA's Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources

Key Issues to be Investigated at Case Study Locations

EPA has selected case studies 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. View the criteria according to which these locations were selected.

EPA currently is working closely with industry partners to identify locations and develop research activities for prospective case studies. EPA will announce the location of its prospective case studies once sites that meet the Agency’s scientific requirements are selected.

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

Area Navigation

  Location   Key Issues to be Investigated   Potential Outcomes   Companies Involved
  • Dunn County, North Dakota (Bakken Shale)
  • 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.
  • Wise County, Texas (Barnett Shale)
  • 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
  • Marcellus Shale: Bradford and Susquehanna Counties, Pennsylvania
  • 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
  • Marcellus Shale: Washington County, Pennsylvania
  • 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: Las Animas County, Colorado
  • 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.