U.S. Geological Survey Study

Shallow Groundwater Quality and Geochemistry in the Fayetteville Shale Gas-Production Area, North-Central Arkansas

While little evidence exists directly linking hydraulic fracturing to environmental harm, such notions have spurred speculation and controversy.

A report released by the United States Geological Survey once again confirms that hydraulic fracturing does not pose a serious risk of polluting drinking water resources.

The study examined the water quality of 127 shallow domestic wells in the Fayetteville Shale – a region with 4,000 completed producing natural gas wells. Scientists analyzed water-quality data from samples taken in Van Buren and Faulkner counties in 2011, focusing on chloride concentrations from 127 wells and methane concentrations and carbon isotope ratios from a subsample of 51 wells.

Report lead Timothy Kresse stated, “none of the data that {USGS} looked at as part of this study suggests that any groundwater contamination is resulting from natural gas production activities.”

Summary of results:

  • Chloride concentrations were not higher in the 2011 samples than in samples from nearby areas collected from 1951 through 1983
  • Chloride concentrations from wells within 2 miles of a gas-production well were similar to concentrations from wells more than 2 miles from a gas-production well
  • Methane concentrations and carbon isotope ratios indicate that almost all methane in groundwater samples is naturally occurring as a result of biological processes in shallow shale formations used as a source of water for domestic purposes and did not originate from the Fayetteville Shale