Water Pollution Risk Associated with Natural Gas Extraction from the Marcellus Shale

Abstract

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.

Evaluating the effects of living with contamination from the lens of trauma: a case study of fracking development in Alberta, Canada

“…Roy, Adams, and Robinson 2014;Howarth, Santoro, and Ingraffea 2012); water pollution and large water withdrawals (e.g. Warner et al 2013;Myers 2012;Rozel and Reaven 2012); earthquakes (e.g. Davies et al 2013;Kim 2013); and human health threats (e.g.…”

Analysis of BTEX groundwater concentrations from surface spills associated with hydraulic fracturing operations

“…Public concerns have been expressed about drinking-water contamination from migration of chemicals used during the hydraulic fracturing process, as well as from the escape of methane from fractured rock and well casings (Dammel et al, 2011;Groat and Grimshaw, 2012;Osborn et al, 2011;Rozell and Reaven, 2012;U.S. EPA, 2011).…”

Monitoring Marcellus: A Case Study of a Collaborative Volunteer Monitoring Project to Document the Impact of Unconventional Shale Gas Extraction on Small Streams

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