Pump jacks and wells are seen in an oil field on the Monterey Shale formation near McKittrick, California. (Photo: David McNew/Getty Images)

Researchers have recently found that the practice of hydraulic fracturing, known as fracking, produces more than just oil and gas: It's been known to cause earthquakes, contaminate groundwater, and increase hydrocarbon emissions, among other impacts. However, the process is still considered less water-intensive than other forms of energy production.

Now, a new study from Duke University has found a dramatic increase in fracking's water footprint in the United States over a five-year period, suggesting that future fracking practices will require far more water than previously estimated.

The paper, published Wednesday in the journal Science Advances, found that water use per well increased by as much as 770 percent from 2011 to 2016, while wastewater volumes rose by as much as 1,440 percent in two Texas shale formations. This increase means more waste—and less drinking water—for local populations living in already-arid regions of the country.

Duke Ph.D. candidate Andrew Kondash, the lead author on the study, analyzed information from six major U.S. fracking sites, including the number of wells drilled, the amount of water required for fracking, and the volume of wastewater produced. Kondash's team found that every region's water use increased during this period, and if drilling picks up between 2018 and 2030, these numbers could multiply 50 times over.

"[This study] necessitates a need to find alternative water sources," Kondash says. "Especially in water-scarce areas, you will have more strain and more competition for water. If you're able to use more remedial sources, like wastewater, or to recycle some of the flow-back and produced water ... that solves some of the problems that the industry is currently facing."

The process of fracking produces so much unusable wastewater that the net water loss "could outweigh its relatively lower water intensity," the study says. After drillers inject fluid into wells for fracking, it returns as a blend of saltwater and harmful chemicals, which is expensive and difficult to treat.

"Almost all of the water used for hydraulic fracturing is kind of a lost cause," Kondash says. "Whereas for other things, like coal mining, the water is returning into the system ... and recharging aquifers."

Although fracking has tapered off in the U.S. since its peak in the early 2010s, companies have begun drilling with new intensity, using tactics that produce more oil, but at a price; Kondash has identified a correlation between increased production in lateral-drilled wells and decreased water-use efficiency. Most wells are drilled straight down, but fracking longer, horizontal wells allows producers to hit new targets—provided there's more water to reach them.

If fracking returns to peak levels, it will likely intensify problems such as water scarcity and groundwater contamination, Kondash says. Already, the Environmental Protection Agency has acknowledged that fracking can release chemicals, spilled fluid, or inadequately treated waste water into local communities' surface and groundwater supplies.

Kondash hopes this study will demonstrate the need for better water management in the oil and gas industry. But in the meantime, he says, researchers must continue to track contamination on a local level, so that everyone knows exactly what's in their water.