The U.S. Environmental Protection Agency Tuesday released its scientific report on the impacts from hydraulic fracturing activities on drinking water resources, which provides states and others the scientific foundation to better protect drinking water resources in areas where hydraulic fracturing is occurring or being considered.
EPA identified conditions under which impacts from hydraulic fracturing activities can be more frequent or severe. The report also identifies uncertainties and data gaps.
These uncertainties and data gaps limited EPA’s ability to fully assess impacts to drinking water resources both locally and nationally.
The report is organized around activities in the hydraulic fracturing water cycle and their potential to impact drinking water resources.
The stages include: (1) acquiring water to be used for hydraulic fracturing (Water Acquisition), (2) mixing the water with chemical additives to make hydraulic fracturing fluids (Chemical Mixing), (3) injecting hydraulic fracturing fluids into the production well to create and grow fractures in the targeted production zone (Well Injection), (4) collecting the wastewater that returns through the well after injection (Produced Water Handling), and (5) managing the wastewater through disposal or reuse methods (Wastewater Disposal and Reuse).
EPA identified cases of impacts on drinking water at each stage in the hydraulic fracturing water cycle.
Impacts cited in the report 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.
As part of the report, EPA identified certain conditions under which impacts from hydraulic fracturing activities can be more frequent or severe, including:
-- Water withdrawals for hydraulic fracturing 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.
Does Not List Documented Impacts
The report provides valuable information about potential vulnerabilities to drinking water resources, but was not designed to be a list of documented impacts.
Data gaps and uncertainties limited EPA’s ability to fully assess the potential impacts on drinking water resources both locally and nationally.
Generally, comprehensive information on the location of activities in the hydraulic fracturing water cycle is lacking, either because it is not collected, not publicly available, or prohibitively difficult to aggregate.
In places where it is known activities in the hydraulic fracturing water cycle have occurred, data that could be used to characterize hydraulic fracturing-related chemicals in the environment before, during, and after hydraulic fracturing were scarce.
Because of these data gaps and uncertainties, as well as others described in the assessment, it was not possible to fully characterize the severity of impacts, nor was it possible to calculate or estimate the national frequency of impacts on drinking water resources from activities in the hydraulic fracturing water cycle.
EPA's final assessment benefited from extensive stakeholder engagement with states, tribes, industry, non-governmental organizations, the scientific community, and the public.
This broad engagement helped to ensure that the final assessment report reflects current practices in hydraulic fracturing and uses all data and information available to the agency.
This report advances the science. The understanding of the potential impacts from hydraulic fracturing on drinking water resources will continue to improve over time as new information becomes available.
The report, done at the request of Congress, provides scientific evidence that hydraulic fracturing activities can impact drinking water resources in the United States under some circumstances.
The final conclusions in the report are based upon 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 value of high quality science has never been more important in helping to guide decisions around our nation’s fragile water resources. 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,” said Dr. Thomas A. Burke, EPA's Science Advisor and Deputy Assistant Administrator of EPA's Office of Research and Development. "This assessment is the most complete compilation to date of national scientific data on the relationship of drinking water resources and hydraulic fracturing."
A copy of the EPA report is available online.
The Department of Environmental Protection maintains a list of cases where DEP has determined that a private water supply was impacted by one or more parts of the conventional or unconventional oil and gas well drilling process.
Since January of 2009 through November 9, 2016, DEP has documented 283 cases of water supplies being affected.
This list is intended to identify historic water supply impacts and does not necessarily represent ongoing impacts.
Many of the water supply complaints have either returned to background conditions, have been mitigated through the installation of water treatment controls or have been addressed through the replacement of the original water supply.
This list is dynamic in nature and will be updated to reflect new water supply impacts as they are reported to DEP and a determination is made; however, the list will retain cases of water supply impacts even after the impact has been resolved.For more information on oil and gas well compliance issues, review DEP’s 2015 Annual Report On The Oil And Gas Regulatory Program.
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