It turns out that U.S. hydraulic fracturing – more commonly known as "fracking" – accounts for less than one percent of water used nationwide for industrial purposes. Compared to other energy extraction methods, fracking might not be as water-intensive as we thought, according to a recent Duke University study.
Hydraulic fracking is a process whereby natural gas is extracted from deep underground wells by pumping water and other materials into the ground to break up the rocks that stores natural gasses. The methods continues to raise concerns for many reasons, including water consumption.
"Water use and wastewater production are two of the chief environmental concerns voiced about hydraulic fracturing," Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment, explained in a news release. "Yet until now we've had only a fragmented and incomplete understanding of how much water is actually being used, and how much wastewater is being produced."'
According to Duke's study, between 2005 to 2014, U.S. energy companies used roughly 250 billion gallons to extract shale gas and oil from hydraulically fractured wells. During this time they also accumulated 210 billion gallons of wastewater. However, this new study suggests we can't judge these numbers based on their face value.
It turns out these numbers actually reflect that fracking – when compared to other energy extraction methods – is much less water-intensive, requiring less water to extract energy and generating less wastewater.
"Our new study, which integrates data from multiple government and industry sources, provides the first comprehensive assessment of fracking's total water footprint, both nationally and for each of the 10 major U.S. shale gas or tight oil basins," Vengosh added.
To be specific, the researchers found that fracking uses between two-and-a-half to 13 times less water per unit of energy produced, than other mining processes use. Also, they found that for each barrel of oil, these other methods accumulate more than three barrels of wastewater, while fracking only fills up half of a barrel.
However, researchers noted that concerns remain about how fracking impacts water supplies.
"While hydraulic fracturing consumes only a small fraction of the water used in other extraction methods, our analysis highlights the fact that it can still pose serious risks to local water supplies, especially in drought-prone regions such as the Barnett formation in Texas, where exploration and development is rapidly intensifying," Kondash said in a statement. "Drilling a single well can require between three to six million gallons of water, and thousands of wells are fracked each year. Local water shortages could limit future production."
Treating wastewater plays a key role in lessening the impacts of hydraulic fracking, the researchers added. Their findings were recently published in the journal Environmental Science & Technology Letters.
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