An exhaustive study by the United States Geological Survey has uncovered no groundwater contamination from natural-gas drilling in the energy-rich Fayetteville Shale in Arkansas.
No Significant Effects Found
The United States Geological Survey (USGS) report, Shallow Groundwater Quality and Geochemistry in the Fayetteville Shale Gas-Production Area, North-Central Arkansas, 2011, analyzed water quality samples taken in Van Buren and Faulkner counties. USGS researchers focused on chloride concentrations taken from 127 wells and methane concentrations and carbon isotope ratios from a subsample of 51 wells.
“For more than 100 years, the USGS has been a source of freely available, unbiased information on our natural resources such as oil, gas, and water, helping government and local leaders make wise decision for the public good,” said USGS Director Marcia McNutt in a press statement. “This new study is important in finding no significant effects on groundwater quality from shale gas development within the area of sampling.”
Chloride was of particular interest to USGS scientists. It moves easily through groundwater without reacting with other ions or compounds, making it, in the words of USGA, “a good indicator of whether chemicals used during hydraulic fracturing are reaching groundwater. In this case, the chloride concentrations from this study were not higher than samples taken from nearby areas from 1951 to 1983.”
Methane, the primary component of natural gas, can be found naturally in shallow shale formations in the Fayetteville Shale. These areas also serve as sources of water for domestic supply. USGS researchers placed a high priority on determining whether fracking might be releasing more methane into area waters.
“What methane was found in the water, taken from domestic wells, was either naturally occurring, or could not be attributed to natural gas production,” USGS reported.
Fayetteville Shale Resources
Though less well known than the Marcellus Shale formation in the U.S. Northeast, the Fayetteville Shale was used for natural gas production several years ahead of the Marcellus play. The gas in the approximately 50-mile-wide formation has been extracted through hydraulic fracturing (fracking) and horizontal drilling, as in similar sites throughout the United States.
Another Blow to Activists
The USGS’s findings cast further doubt on claims by anti-fracking activists that the practice poses a risk to groundwater.
“When environmental activists talk about hydraulic fracturing, they frequently call it ‘dangerous’ or ‘controversial.’ But time after time, in study after study, hydraulic fracturing is shown to have a clean bill of environmental health, as the USGS’s recent findings in Arkansas confirm,” said Daniel Simmons, director of state policy at the Institute for Energy Research.
“The fact remains that there are no confirmed cases of groundwater contamination from hydraulic fracturing” anywhere in the United States, Simmons noted.
EPA Extends Comment Period
In a related development, the U.S. Environmental Protection Agency (EPA) announced in January that it is extending public comment on its investigation of chemicals found in water near Pavillion, Wyoming. Without fully explaining its reasons, EPA extended the comment period, originally scheduled to expire in mid-January, until Sept. 30.
In late 2011, EPA issued a draft report claiming its researchers had found chemicals consistent with hydraulic fracturing in groundwater near Pavillion, but not in drinking water. EPA did not present any evidence the chemicals, which are also consistent with activities other than fracking, were a byproduct of fracking in the region. State environmental officials said EPA itself had contaminated the groundwater when it drilled two monitoring wells.
Bonner R. Cohen, Ph. D. ([email protected]), is a senior fellow at the National Center for Public Policy Research in Washington, DC.
Shallow Groundwater Quality and Geochemistry in the Fayetteville Shale Gas-Production Area, North-Central Arkansas, 2011, U.S. Geological Survey, Jan. 9, 2013: http://news.heartland.org/sites/default/files/ar_fracking_study_jan_2013.pdf