title: Impact of Marcellus Shale natural gas development in southwest Pennsylvania on volatile organic compound emissions and regional air quality.
abstract: The Marcellus Shale is the largest natural gas deposit in the U.S. and rapid development of this resource has raised concerns about regional air pollution. A field campaign was conducted in the southwestern Pennsylvania region of the Marcellus Shale to investigate the impact of unconventional natural gas (UNG) production operations on regional air quality. Whole air samples were collected throughout an 8050 km(2) grid surrounding Pittsburgh and analyzed for methane, carbon dioxide, and C1-C10 volatile organic compounds (VOCs). Elevated mixing ratios of methane and C2-C8 alkanes were observed in areas with the highest density of UNG wells. Source apportionment was used to identify characteristic emission ratios for UNG sources, and results indicated that UNG emissions were responsible for the majority of mixing ratios of C2-C8 alkanes, but accounted for a small proportion of alkene and aromatic compounds. The VOC emissions from UNG operations accounted for 17 ± 19% of the regional kinetic hydroxyl radical reactivity of nonbiogenic VOCs suggesting that natural gas emissions may affect compliance with federal ozone standards. A first approximation of methane emissions from the study area of 10.0 ± 5.2 kg s(-1) provides a baseline for determining the efficacy of regulatory emission control efforts.
authors.affiliation: Natural Resources and Earth System Science Program, University of New Hampshire , Durham, New Hampshire 03824, United States.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Swarthout
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Russo
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Brandon M
authors.initials: BM
authors.lastname: Miller
authors.forename: Brittney
authors.initials: B
authors.lastname: Mitchell
authors.forename: Emily
authors.initials: E
authors.lastname: Horsman
authors.forename: Eric
authors.initials: E
authors.lastname: Lipsky
authors.forename: David C
authors.initials: DC
authors.lastname: McCabe
authors.forename: Ellen
authors.initials: E
authors.lastname: Baum
authors.forename: Barkley C
authors.initials: BC
authors.lastname: Sive
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000592:standards*; D002245:Carbon Dioxide / Q000032:analysis*; D004784:Environmental Monitoring / Q000592:standards / Q000706:statistics & numerical data*; D008697:Methane / Q000032:analysis*; D059206:Natural Gas / Q000032:analysis; D061329:Oil and Gas Fields; D010414:Pennsylvania; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D059206:Natural Gas; D055549:Volatile Organic Compounds; D002245:Carbon Dioxide; D008697:Methane