The United States’ Environmental Protection Agency (EPA) has released a scientific report (13 December 2016), requested by Congress, on the impacts of fracking (hydraulic fracturing) on drinking water resources, which proves that fracking can impact drinking water under some circumstances.

The EPA study, called ‘Hydraulic Fracturing for Oil and Gas: Impacts from the Hydraulic Fracturing Water Cycle on Drinking Water Resources in the United States’, identifies cases of impacts on drinking water at each stage in the hydraulic fracturing water cycle. These generally occurred near hydraulically fractured oil and gas production wells and ranged in severity, from temporary changes in water quality, to contamination that made private drinking water wells unusable.

The report’s conclusions are based on review of over 1,200 cited scientific sources, feedback from an independent peer review conducted by EPA’s Science Advisory Board, input from engaged stakeholders, and new research conducted as part of the study.

The findings are aimed at helping to guide decisions on the nation’s water resources. However, EPA said that data gaps and uncertainties limited its ability to fully assess the potential impacts on local and national drinking water resources.

EPA's Science Advisor, Dr. Thomas A. Burke, said: "This assessment is the most complete compilation to date of national scientific data on the relationship of drinking water resources and hydraulic fracturing. EPA's assessment provides the scientific foundation for local decision makers, industry, and communities that are looking to protect public health and drinking water resources and make more informed decisions about hydraulic fracturing activities.”

Conditions under which impacts from fracking were found to be more frequent or severe, included:

• Water withdrawals for fracking in times or areas of low water availability, particularly in areas with limited or declining groundwater resources;
• Spills during the management of hydraulic fracturing fluids and chemicals or produced water that result in large volumes or high concentrations of chemicals reaching groundwater resources;
• Injection of hydraulic fracturing fluids into wells with inadequate mechanical integrity, allowing gases or liquids to move to groundwater resources;
• Injection of hydraulic fracturing fluids directly into groundwater resources;
• Discharge of inadequately treated hydraulic fracturing wastewater to surface water resources; and
• Disposal or storage of hydraulic fracturing wastewater in unlined pits, resulting in contamination of groundwater resources.

With a UK consultation on fracking and water currently underway, the industry will need to take the EPA's findings into account.

Image of fracking process: iStock (c) selvanegra