Effects of 'pre-fracking' operations on ambient air quality at a shale gas exploration site in rural North Yorkshire, England

Ruth M Purvis; Alastair C Lewis; James R Hopkins; Shona E Wilde; Rachel E Dunmore; Grant Allen; Joseph Pitt; Robert S Ward

doi:10.1016/j.scitotenv.2019.04.077

Effects of 'pre-fracking' operations on ambient air quality at a shale gas exploration site in rural North Yorkshire, England

Sci Total Environ. 2019 Jul 10:673:445-454. doi: 10.1016/j.scitotenv.2019.04.077. Epub 2019 Apr 8.

Authors

Ruth M Purvis¹, Alastair C Lewis², James R Hopkins², Shona E Wilde³, Rachel E Dunmore³, Grant Allen⁴, Joseph Pitt⁴, Robert S Ward⁵

Affiliations

¹ National Centre of Atmospheric Science, Dept. of Chemistry, University of York, UK. Electronic address: ruth.purvis@york.ac.uk.
² National Centre of Atmospheric Science, Dept. of Chemistry, University of York, UK.
³ Dept. of Chemistry, University of York, UK.
⁴ School of Earth and Environmental Sciences, University of Manchester, UK.
⁵ British Geological Survey, Keyworth, UK.

PMID: 30991334
DOI: 10.1016/j.scitotenv.2019.04.077

Abstract

Rural observations of air quality and meteorological parameters (NO_x, O₃, NMHCs, SO₂, PM) were made over a 2.5-year period (2016-2018) before, during and after preparations for hydraulic fracturing (fracking) at a shale gas exploration site near Kirby Misperton, North Yorkshire, England. As one of the first sites to apply for permits to carry out hydraulic fracturing, it has been subject to extensive regulatory and public scrutiny, as well as the focus for a major programme of long-term environmental monitoring. A baseline period of air quality monitoring (starting 2016) established the annual climatology of atmospheric composition against which a 20-week period of intensive activity on the site in preparation for hydraulic fracturing could be compared. During this 'pre-operational phase' of work in late 2017, the most significant effect was an increase in ambient NO (3-fold) and NO_x (2-fold), arising from a combination of increased vehicle activity and operation of equipment on site. Although ambient NO_x increased, air quality limit values for NO₂ were not exceeded, even close to the well-site. Local ozone concentrations during the pre-operational period were slightly lower than the baseline phase due to titration with primary emitted NO. The activity on site did not lead to significant changes in airborne particulate matter or non-methane hydrocarbons. Hydraulic fracturing of the well did not subsequently take place and the on-site equipment was decommissioned and removed. Air quality parameters then returned to the original (baseline) climatological conditions. This work highlights the need to characterise the full annual climatology of air quality parameters against which short-term local activity changes can be compared. Based on this study, changes to ambient NO_x appear to be the most significant air quality ahead of hydraulic fracturing. However, in rural locations, concentrations at individual sites are expected to be below ambient air quality limit thresholds.

Keywords: Air quality; Environmental baseline monitoring; Fracking; Hydraulic fracturing; NO(x) emissions.