eprintid: 1709 rev_number: 11 eprint_status: archive userid: 6 dir: disk0/00/00/17/09 datestamp: 2016-07-08 07:52:52 lastmod: 2017-02-08 12:21:31 status_changed: 2016-07-08 07:52:52 type: article metadata_visibility: show creators_name: Ahmadi, Mahdi creators_name: John, Kuruvilla corp_creators: University of North Texas, Denton, TX, USA corp_creators: University of North Texas, Denton, TX, USA title: Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas subjects: O subjects: RU2 subjects: SHU divisions: SHEER full_text_status: none keywords: Shale gas; Hydraulic fracturing; Ozone pollution; Meteorological adjustment; Barnett Shale; Statistical evaluation; Ozone trend abstract: Over the past decade, substantial growth in shale gas exploration and production across the US has changed the country's energy outlook. Beyond its economic benefits, the negative impacts of shale gas development on air and water are less well known. In this study the relationship between shale gas activities and ground-level ozone pollution was statistically evaluated. The Dallas–Fort Worth (DFW) area in north-central Texas was selected as the study region. The Barnett Shale, which is one the most productive and fastest growing shale gas fields in the US, is located in the western half of DFW. Hourly meteorological and ozone data were acquired for fourteen years from monitoring stations established and operated by the Texas Commission on Environmental Quality (TCEQ). The area was divided into two regions, the shale gas region (SGR) and the non-shale gas (NSGR) region, according to the number of gas wells in close proximity to each monitoring site. The study period was also divided into 2000–2006 and 2007–2013 because the western half of DFW has experienced significant growth in shale gas activities since 2007. An evaluation of the raw ozone data showed that, while the overall trend in the ozone concentration was down over the entire region, the monitoring sites in the NSGR showed an additional reduction of 4% in the annual number of ozone exceedance days than those in the SGR. Directional analysis of ozone showed that the winds blowing from areas with high shale gas activities contributed to higher ozone downwind. KZ-filtering method and linear regression techniques were used to remove the effects of meteorological variations on ozone and to construct long-term and short-term meteorologically adjusted (M.A.) ozone time series. The mean value of all M.A. ozone components was 8% higher in the sites located within the SGR than in the NSGR. These findings may be useful for understanding the overall impact of shale gas activities on the local and regional ozone pollution. date: 2015-12 date_type: published publication: Science of The Total Environment volume: 536 publisher: Elsevier pagerange: 457-467 id_number: doi:10.1016/j.scitotenv.2015.06.114 issn: 0048-9697 official_url: http://doi.org/10.1016/j.scitotenv.2015.06.114 access_IS-EPOS: limited owner: Publisher citation: Ahmadi, Mahdi and John, Kuruvilla (2015) Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas. Science of The Total Environment, 536. pp. 457-467. DOI: https://doi.org/10.1016/j.scitotenv.2015.06.114