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ACS News Service Weekly PressPac: September 16, 2015

How much water do U.S. fracking operations really use?

"The Water Footprint of Hydraulic Fracturing"
Environmental Science & Technology Letters

The oil and gas extraction method called hydraulic fracturing remains controversial for multiple reasons, one of which is its water use. But, as scientists report in ACS’ journal Environmental Science & Technology Letters, water requirements for the process are potentially lower than those for some other energy-related extraction methods.

Since oil and gas companies ramped up hydraulic fracturing, or fracking, to unlock oil and gas from shale and tight oil formations, reports of earthquakes and contaminated water near wells proliferated. Some environmental experts have also raised concerns over the huge volumes of water required to make these unconventional wells, especially in drought-stricken places. But assessing this latter concern was difficult since no one had a complete picture of how much water has been used in fracking operations across the country. So Avner Vengosh and Andrew Kondash decided to find out.

The researchers culled data from multiple sources, including government agencies and industry. They estimated that energy companies consumed nearly 250 billion gallons of water between 2005 and 2014 for hydraulic fracturing. This is more water per unit of energy produced than conventional oil and gas exploration requires for drilling and cementing wells. But underground coal and uranium mining, as well as enhanced oil recovery, use about two-and-a-half to 13 times more water per unit of energy produced. Also, they calculated that water for fracking accounts for less than 1 percent of annual total industrial water use in the U.S. Still, the researchers note that in drought-stricken areas such as the Barnett formation in Texas, home to thousands of unconventional wells, local water shortages could limit future use of hydraulic fracturing.

The authors acknowledge funding from the National Science Foundation and the Duke University Energy Initiative.

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Hydraulic fracturing requires varying amounts of water depending on the shale formation (darker blue indicates heavier water use).
Credit: American Chemical Society
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