Correction to Methane Concentrations in Water Wells Unrelated to Proximity to Existing Oil and Gas Wells in Northeastern Pennsylvania

Abstract

The authors thank the Chesapeake Energy Corporation for access to their baseline groundwater data set for NE Pennsylvania and for providing funding for the authors through their organizations of employment, and privately, in the case of the senior author, to do basic research to explore and evaluate this very large data set. The opinions and conclusions expressed in this paper are strictly those of the authors and do not necessarily reflect those of Chesapeake Energy. We also thank the landowners who allowed their water wells to be sampled.None of the authors have competing corporate financial interests exceeding guidelines presented by ES&T.

Groundwater‐quality hazards of methane leakage from hydrocarbon wells: A review of observational and numerical studies and four testable hypotheses

“…The challenge in identifying relationships between oil and gas drilling and stray methane in the subsurface is best illustrated by the studies that have investigated the issue as it relates to northeastern Pennsylvania (e.g., Hammond, ; Jackson, Vengosh, et al, ; Molofsky, Connor, Farhat, Wylie, & Wagner, ; Molofsky, Connor, Wylie, Wagner, & Farhat, ; Osborn, Vengosh, Warner, & Jackson, ; Siegel, Azzolina, Smith, Perry, & Bothun, ). Osborn et al () and Jackson, Vengosh, et al () collected samples from water wells in regions with active (northeastern Pennsylvania) and nonactive (New York, where hydraulic fracturing currently is not allowed) unconventional oil and gas operations.…”

“…No regional trends were identified between the proximity of water wells to oil and gas operations and stray methane contamination. Instead, topography and groundwater geochemistry were identified as influencing methane concentration, suggesting natural migration of thermogenic methane from the deep subsurface into shallow groundwater (Molofsky et al, ; Siegel et al, ).…”

“…Instead, they describe a complex system in which methane migrates into shallow aquifers both naturally through deeply circulating groundwater upwelling in valleys and unnaturally via enhanced pathways created by oil and gas drilling (e.g., Dusseault et al, ; Ingraffea, Wells, Santoro, & Shonkoff, ; Jackson et al, ; Kang et al, , ; Lackey, Rajaram, Sherwood, Burke, & Ryan, ; Pétron et al, ; Watson & Bachu, ). Molofsky et al () and Siegel et al () had access to data sets large enough to investigate regional trends of methane occurrence in groundwater. However, these studies lack the detailed isotopic measurements necessary to distinguish between natural and anthropogenically induced methane migration.…”

“…However, these studies lack the detailed isotopic measurements necessary to distinguish between natural and anthropogenically induced methane migration. Furthermore, they analyze private databases maintained by oil and gas companies, which lack the transparency of publicly available data sets (Siegel et al, ). Osborn et al () and Jackson, Gorody, et al () performed gas compositional and isotopic analyses, but these studies were limited by the size of their sampling data sets ( n = 68 and 141) and therefore could not investigate regional‐scale trends.…”

‘Shooting the messenger’: some reflections on what happens doing science in the public arena

“…Collins, ). ES & T prudently asked my colleagues and me for more details, and we provided the largest and most detailed disclosure statement I have ever written (Siegel et al ., ).…”