Emissions of particulate matter due to Marcellus Shale gas development in Pennsylvania: Mapping the implications

Abstract

Over the past decade, the shale gas boom has led to increasing public concerns regarding communities' exposure to air pollutants from shale gas development resulting in concentrations higher than the EPA's National Ambient Air Quality Standards. This study investigates the sufficiency of current policy in Pennsylvania to protect people from exposure to fine particulate matter (PM2.5) emissions from such development. We used a Gaussian plume model to simulate PM2.5 concentrations over the Marcellus shale region of Pennsylvania, and using census block data, we estimated the potential number of people who experienced exceedance of the PM2.5 standard between 2005 and 2017. Results demonstrate that these emissions could increase the number of exceedances by more than 36,000 persons in a single year which is almost 1% of the Marcellus shale regional population in Pennsylvania. This number has largely been proportional to the overall number of developed wells, but development histories show that similar levels of development could occur with reduced population exposure. Setback policy is shown to be an effective method to reduce exposure exceedances, but results suggest that it should be revised based on the number of wells per wellpad as well as the local conditions to further limit air quality impacts.