Estimating Wastewater Impacts from Fracking

Wastewater produced by hydraulic fracturing (" fracking ") for natural gas in the Marcellus Shale is already overwhelming disposal options and will continue to do so as gas development increases, according to newly published research. The investigation did not evaluate environmental consequences of the wastewater. But lead author Brian Lutz, an assistant professor in the Kent State University Department of Biology, says fracking wastewater could have a range of environmental and health impacts if not managed correctly. The analysis was limited to Pennsylvania, which along with West Virginia dominates Marcellus shale gas production today. 2 During fracking, a fluid mixture pumped deep underground fractures the rock to liberate trapped natural gas, which then rises through the well to the surface. Fracking fluids amount to between 3 and 7 million gallons of water per well, 3 mixed with sand and a complex chemical mixture that can include naphthalene, formaldehyde, and a variety of volatile organic compounds, among other substances. 4 Since the 1850s, natural gas has been extracted from a number of relatively shallow formations. But advances in horizontal fracking have enabled the development of shale gas deposits, most of which are more than a mile underground in the Marcellus and even deeper in other formations such as the Woodford Shale in Oklahoma. 5 In 2010 shale gas contributed 23% of domestic natural gas production, compared with 2% in 2000. And of that, about 10% came from the Marcellus, which in recent months has become the biggest producer of shale gas in the United States. 2 Correspondingly, the amount of wastewater generated by fracking in the Marcellus rose nearly sixfold between 2004 and 2011, such that it increasingly dwarfs amounts produced by conventional gas drilling—even though conventional gas production generates 65% more wastewater per unit of recovered gas than fracking does. According to Kevin Sunday, the deputy press secretary with the Pennsylvania Department of Environmental Protection (DEP), gas producers in Pennsylvania traditionally sent their wastewater to municipal water treatment plants for purification and then discharge into rivers. But with the shift to nonconventional production, the wastewater—which is enriched with heavy metals, radionuclides, and salts liberated from the shale rock below 1 —became harder to deal with. Removing dissolved salts, in particular, requires expensive distillation or reverse osmosis. Citing these environmental concerns, DEP secretary Michael Krancer called on the Marcellus Shale industry to cease wastewater delivery to municipal sewage plants in April …