In some drier locations, the shale gas boom causes conflict among the energy industry, agricultural interests and residents over already-scarce water resources, according to researchers writing in the journal Environmental Science & Technology.
According to Regional Variation in Water-Related Impacts of Shale Gas Development and Implications for Emerging International Plays, a major criticism of extracting shale gas through hydraulic fracturing, or fracking, is that it requires tremendous amounts of water — 2.5 to 5 million gallons — to develop a single well. Water, along with chemicals and sand, is injected under high pressure into wells to create cracks, or fractures, in shale and release stored gas.
The research by Carnegie Mellon University‘s Meagan S. Mauter and colleagues says that in some water-rich places, such as Pennsylvania, this is not a significant problem. But in other locations, including some rural counties in arid south Texas, this level of water use competes with residential and agricultural needs and depletes groundwater resources. Degraded water quality is also a potential risk unless adequate safeguards are in place, according to the research.
However, according to the research there are ways to minimize the industry’s water footprint. One method is to use brackish water that is not fit for drinking or agricultural use but can be suitable for fracking. The US Geological Survey’s 1965 survey suggests that US brackish water resources are geographically consistent with major US shale basins (see image).
Another method is to recycle the waste water.
Advanced dialysis technology developed by researchers at the University of British Columbia and announced in March could reduce the use of fresh water and carbon dioxide emissions generated during hydraulic fracturing.
The system has the potential for use in any location where brine and waste carbon dioxide are present, UBC says. Once commercialized, the system is expected to have the capacity to reduce CO2 emissions by 1 metric ton per year and more than 2 billion liters of fresh water for tight oil and shale gas extraction in Alberta, UBC says.