The graphic at right, shows the distribution of water consumption per frack job reported via the voluntary industry reporting database FracFocus.org (raw data available here). As you can see, the average here appears to be around 2 million gallons per frack job, but (a) some wells are fracked multiple times and (b) there may be some systemic downward bias inherent in the voluntary nature of the FracFocus.org data set. So 5 million gallons per looks like a good solid average estimate.
There were 27,000 new gas wells completed in the US in 2011, according to the US Energy Information Administration (EIA). Shale gas wells represented virtually all of the increase in gas production from 2010 to 2011.
Given those assumptions, all shale gas wells completed in 2011 across the United States consumed on the order of 135 billion gallons of water.
All freshwater water withdrawals in the US (surface and groundwater) totaled about 127,750 billion gallons in 2005. Assuming 2005 is a fair baseline for total annual water withdrawals in the United States, that means water consumed to frack all U.S. shale gas wells in 2011 represents on the order of 0.1 percent of total U.S. freshwater withdrawals.
Jessee Jenkins, The Energy Collective, April 6 2013. "Energy Facts: How Much Water Does Fracking for Shale Gas Consume?". http://www.theenergycollective.com/jessejenkins/205481/friday-energy-facts-how-much-water-does-fracking-shale-gas-consume.
Post updated at Thursday 2nd of July 2015 9:53:25 AM.