Friday, February 14, 2014

Water use for fracking exacerbating water shortages?


While fracking has helped reduce CO2 emissions in the US (see previous post), expanding the use of this technology is meeting a lot of resistance from many environmentalists. Some worry that cheap natural gas increases the challenge for wind and solar technologies.  Others worry about the fugitive natural gas that could quickly negate any benefits of the reduced CO2 emissions because of the 20X global warming potential of natural gas. Still other concerns have to do with ground water contamination, or just water use. A typical fracking well takes between 2 and 4 million gallons of water.  To help visualize a million gallons, picture an Olympic swimming pool, 100 m x 25 m and 2 m deep.  It holds 660,000 gallons, and so a million gallons is a half larger than an Olympic swimming pool.


A recent report by Ceres, a nonprofit organization dedicated to increasing awareness among business leaders and investors about issues of climate change and water scarcity, asserts that water used for fracking was depleting water in arid regions and thus exacerbating the water shortage. This report attracted a lot of media attention.  The headline for the story in The Guardian ran, “Fracking is depleting water supplies in America’s driest areas, report shows.”

While it is true that water use in dry areas diverts the resource from other uses some quantitative consideration is needed to provide perspective.  As I read through the Guardian article, I found this bit of information: Fracking operations in Texas (the state with most frack wells) used about 48 billion gallons of water. 
Now, 48 billion gallons sure sounds a lot; and yes, Texas is pretty arid.  The question one has to ask is how much water does the state use? A little searching led me to the fact that in 2010 Texas used 22 million acre-feet of water, which translates to 7,168 billion gallons of water. In other words, all the water used for fracking in Texas represents just 0.68% of water used in one year! Pointing to fracking as the reason for the water shortage is clearly misplacing the blame.

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