Impact of Shale Gas Development on Regional Water Quality by R. D. Vidic, S. L. Brantley, J. M. Vandenbossche, D. Yoxtheimer, J. D. Abad, May 17, 2013, Science, Vol. 340 no. 6134 DOI: 10.1126/science.1235009
These technologies are not free from environmental risks, however, especially those related to regional water quality, such as gas migration, contaminant transport through induced and natural fractures, wastewater discharge, and accidental spills. We review the current understanding of environmental issues associated with unconventional gas extraction. Improved understanding of the fate and transport of contaminants of concern and increased long-term monitoring and data dissemination will help manage these water-quality risks today and in the future.
Energy future may be swamped in fracking wastewater, scientists warn by John Roach, May 16. 2013, NBC News
The current boom in U.S. natural gas production from glassy shale rock formations is poised to usher in an era of energy independence and could bridge the gap between today’s fossil-fuel age and a clean-energy future. But that future may be swamped in a legacy of wastewater, a new study suggests. Natural gas production is soaring thanks to hydraulic fracturing, or fracking, a technique that shoots several million gallons of water laced with chemicals and sand deep underground to break apart chunks of the glassy rock, freeing trapped gas to escape through cracks and fissures into wells. On average of 10 percent of this water flows back to the surface within a few weeks of the frack job. The rest is absorbed by the surrounding rock and mixes with briny groundwater, explained Radisav Vidic, a civil and environmental engineer at the University of Pittsburgh. “What happens to that water is a very good question,” he told NBC News. “We would like to know how much of it stays in the shale, and for how long, and is there a potential for migration away from the well.” Vidic led a review study of the scientific literature looking into these questions, which is published in Thursday’s issue of the journal Science. He said there is a small risk that some of this water could find its way into a crack that leads up to drinking-water aquifers. Most, though, follows the path of least resistance back to the well and flows out at the rate of around 30 to 50 gallons per day. “And what comes back out is much, much worse than anything you put in there, so the real concern is, what do you do with the water that comes back out? Because that’s where the potential for major environmental impact occurs,” he said. This wastewater, he noted, is 10 times saltier than seawater and contains naturally occurring radioactive material released from the shale. …
Eventually — and no one knows for sure when — more wastewater will be produced than there are new wells being drilled. The technology exists to treat the wastewater, but it is expensive and will leave behind mountains of salt and other solids that will need a proper home. “The thing is, the industry is simply not addressing it right now,” Vidic said. This oversight, he added, has potential be the source of panic and environmental woe when drilling slows. The natural-gas industry downplays the issue. The concern is “a hypothetical situation that doesn’t actually reflect what is really going on,” Steve Everly, a spokesman for Energy-in-Depth, an industry trade group, told NBC News. A sudden deluge of wastewater, he noted, is “highly unlikely.” But if it were to happen, he said, “companies would still be treating and finding a way to do something with the wastewater in a responsible fashion.” That wait-and-see approach worries Kate Sinding, who directs the community fracking defense project for the National Resources Defense Council, an environmental group. She pointed out that wastewater cannot be reused indefinitely. [Emphasis added]