title: Methane concentrations in water wells unrelated to proximity to existing oil and gas wells in northeastern Pennsylvania.
abstract: Recent studies in northeastern Pennsylvania report higher concentrations of dissolved methane in domestic water wells associated with proximity to nearby gas-producing wells [ Osborn et al. Proc. Natl. Acad. Sci. U. S. A. 2011 , 108 , 8172 ] and [ Jackson et al. Proc. Natl. Acad. Sci. U. S. A. , 2013 , 110 , 11250 ]. We test this possible association by using Chesapeake Energy's baseline data set of over 11,300 dissolved methane analyses from domestic water wells, densely arrayed in Bradford and nearby counties (Pennsylvania), and near 661 pre-existing oil and gas wells. The majority of these, 92%, were unconventional wells, drilled with horizontal legs and hydraulically fractured. Our data set is hundreds of times larger than data sets used in prior studies. In contrast to prior findings, we found no statistically significant relationship between dissolved methane concentrations in groundwater from domestic water wells and proximity to pre-existing oil or gas wells. Previous analyses used small sample sets compared to the population of domestic wells available, which may explain the difference in prior findings compared to ours.
authors.affiliation: †Department of Earth Sciences, Syracuse University, 204 and 314 Heroy Geology Lab, Syracuse, New York 13244, United States.
authors.forename: Donald I
authors.initials: DI
authors.lastname: Siegel
authors.affiliation: ‡The CETER Group, Inc., 1027 Faversham Way, Green Bay, Wisconsin 54313, United States.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Azzolina
authors.affiliation: §Enviro Clean Products and Services, 11717 North Morgan Road, P.O. Box 721090, Yukon, Oklahoma 73172-1090, United States.
authors.forename: Bert J
authors.initials: BJ
authors.lastname: Smith
authors.affiliation: ∥AECOM Technology Corporation, 250 Apollo Drive, Chelmsford, Massachusetts 01824, United States.
authors.forename: A Elizabeth
authors.initials: AE
authors.lastname: Perry
authors.affiliation: ⊥AECOM Technology Corporation, 1601 Prospect Parkway, Fort Collins, Colorado 80525, United States.
authors.forename: Rikka L
authors.initials: RL
authors.lastname: Bothun
mesh_terms: D004784:Environmental Monitoring; D060587:Groundwater / Q000032:analysis; D016015:Logistic Models; D008697:Methane / Q000032:analysis*; D061329:Oil and Gas Fields; D010414:Pennsylvania; D060986:Water Wells
chemical_list: D008697:Methane