Shale Gas Development Impacts on Surface Water Quality in Pennsylvania, by Sheila M. Olmstead, Lucija A. Muehlenbachs, Jhih-Shyang Shih, Ziyan Chu, and Alan J. Krupnick. PNAS, 110(13):4962-4967 doi: 10.1073/pnas.1213871110 (March 2013)
Concern has been raised in the scientific literature about the
environmental implications of extracting natural gas from deep shale formations, and published studies suggest that shale gas development may affect local groundwater quality. The potential for surface water quality degradation has been discussed in prior work, although no empirical analysis of this issue has been published. The potential for large-scale surface water quality degradation has affected regulatory approaches to shale gas development in some US states, despite the dearth of evidence. This paper conducts a large-scale examination of the extent to which shale gas develop- ment activities affect surface water quality. Focusing on the Marcel- lus Shale in Pennsylvania, we estimate the effect of shale gas wells and the release of treated shale gas waste by permitted treatment facilities on observed downstream concentrations of chloride (Cl−) and total suspended solids (TSS), controlling for other factors. Results suggest that (i) the treatment of shale gas waste by treat- ment plants in a watershed raises downstream Cl− concentrations but not TSS concentrations, and (ii) the presence of shale gas wells in a watershed raises downstream TSS concentrations but not Cl− concentrations. These results can inform future voluntary measures taken by shale gas operators and policy approaches taken by regulators to protect surface water quality as the scale of this economically important activity increases.
Senior author Sheila Olmstead will be speaking here tonight (LaSells Stewart Center, 6:30 PM, free) on 'Fracking and Surface Water Quality: Impacts and Policy Implications'. I am planning to go (see abstract below).
Due to advances in hydraulic fracturing, horizontal drilling, and seismic imaging, the development of energy resources from lowpermeability deep shale formations has increased dramatically in the United States, and development may be poised to take off elsewhere around the globe. Potential impacts on water resources are a primary focus of public opposition, yet empirical evidence of actual impacts is just beginning to emerge. How generalizable are these results? What are the policy implications? These questions and others will be addressed.
On 30 May she will give a more technical talk, 'Damming the Commons: An Empirical Analysis of International Cooperation and Conflict in Dam Placement', 3:30 - 5:00 PM, 019 Milam Hall.