The rapid expansion of hydraulic fracturing to retrieve once-inaccessible reservoirs of oil and gas could put pressure on already-stressed water resources from the suburbs of Fort Worth to western Colorado, according to a new report from a nonprofit group that advises investors about companies' environmental risks.
"Given projected sharp increases" in the production of oil and gas by the technique commonly known as fracking, the report from the group Ceres said, "and the intense nature of local water demands, competition and conflicts over water should be a growing concern for companies, policy makers and investors."
The overall amount of water used for fracking, even in states like Colorado and Texas that have been through severe droughts in recent years, is still small: in many cases 1 percent or even as little as a tenth of 1 percent of overall consumption, far less than agricultural or municipal uses.
But those figures mask more significant local effects, the report's author, Monika Freyman, said in an interview. "You have to look at a county-by-county scale to capture the intense and short-term impact on water supplies," she said.
"The whole drilling and fracking process is a well-orchestrated, moment-by-moment process" requiring that one million to five million gallons of water are available for a brief period, she added. "They need an intense amount of water for a few days, and that's it."
One of the options that oil and gas drillers have is recycling the water that comes back out of wells, which is called "produced water." But the water injected into wells is laced with a proprietary mixture of chemicals and sand, and the water returning from thousands of feet below the surface can also contain natural pollutants or even radioactivity. Recycled water must therefore be treated, which can be expensive.
An earlier report done by engineers at the University of Texas, Austin, showed that 8,800 acre-feet -- nearly 2.9 billion gallons -- were used for fracking in 2011 in Tarrant County in North Texas, where Fort Worth is located and which has gone to the Supreme Court to get access to Oklahoma's water.
And in the Eagle Ford shale formation in South Texas, particularly in Webb County, some researchers estimate that the amount of water used for fracking represents as much as one-third of the area's annual groundwater recharge, the amount of surface water that percolates back to the underground aquifer supplying the region.
But the Ceres report notes that drillers in the Eagle Ford formation are also expanding their use of brackish, undrinkable water in place of fresh water.
While the local effects in Texas have been sufficient to spur the state's Railroad Commission, which regulates the oil and gas industry there, to encourage recycling by loosening rules governing that process, it is Colorado that faces the most widespread potential conflicts between fracking and other water uses, according to Ceres's new report.
Kenneth H. Carlson, an engineering professor at Colorado State University, saw little difference between drillers buying needed water and cities buying water from farmers. "It's a private commodity that people can do with what they want," he said. "We're not going to go thirsty. We're just going to have to pay more."science
This article originally appeared in The New York Times.