Department of Technology and Society, State University of New York at Stony Brook, Stony Brook, NY, USA.
Water Pollution Risk Associated with Natural Gas Extraction from the Marcellus Shale
Article first published online: 28 DEC 2011
© 2012 Society for Risk Analysis
Volume 32, Issue 8, pages 1382–1393, August 2012
How to Cite
Rozell, D. J. and Reaven, S. J. (2012), Water Pollution Risk Associated with Natural Gas Extraction from the Marcellus Shale. Risk Analysis, 32: 1382–1393. doi: 10.1111/j.1539-6924.2011.01757.x
- Issue published online: 9 AUG 2012
- Article first published online: 28 DEC 2011
- probability bounds analysis;
In recent years, shale gas formations have become economically viable through the use of horizontal drilling and hydraulic fracturing. These techniques carry potential environmental risk due to their high water use and substantial risk for water pollution. Using probability bounds analysis, we assessed the likelihood of water contamination from natural gas extraction in the Marcellus Shale. Probability bounds analysis is well suited when data are sparse and parameters highly uncertain. The study model identified five pathways of water contamination: transportation spills, well casing leaks, leaks through fractured rock, drilling site discharge, and wastewater disposal. Probability boxes were generated for each pathway. The potential contamination risk and epistemic uncertainty associated with hydraulic fracturing wastewater disposal was several orders of magnitude larger than the other pathways. Even in a best-case scenario, it was very likely that an individual well would release at least 200 m3 of contaminated fluids. Because the total number of wells in the Marcellus Shale region could range into the tens of thousands, this substantial potential risk suggested that additional steps be taken to reduce the potential for contaminated fluid leaks. To reduce the considerable epistemic uncertainty, more data should be collected on the ability of industrial and municipal wastewater treatment facilities to remove contaminants from used hydraulic fracturing fluid.