EVALUATING A LINK BETWEEN SHALE GAS EXTRACTION ACTIVITIES AND GROUNDWATER/SOCIETAL IMPACTS

Recent advances in shale gas extraction practices (i.e, hydraulic fracturing) have allowed for a rapid expansion in U.S. natural gas production. However, concerns remain with regards to potential impacts to shallow groundwater quality and resulting effects on human health. Here we conduct a joint geochemical study and citizen survey to evaluate a potential link between shale gas hydraulic fracturing and impacts to groundwater quality and human health. As part of this study, approximately 20 private shallow drinking water wells in Bradford and Susquehanna Counties in Pennsylvania were sampled and analyzed for methane, total conductivity, and select elemental constituents. These same residents were also administered a survey documenting perceived changes in water quality and resident health since commencement of drilling activities as well as their opinions on shale gas hydraulic fracturing. The analytical results revealed detectable methane concentrations in over 50% of the wells, the majority of which were in excess of 14 ppm. In addition, a positive correlation was observed between methane concentrations and total conductivity. The survey revealed a statistically significant decrease in residents’ opinions of their water quality before and after drilling commenced in their immediate area. A significant negative correlation was also observed between the residents’ rating of their health and the concentrations of methane found in their drinking water well. Finally, while the majority of residents interviewed supported hydraulic fracturing because of the economic benefits, most of these residents did not drink their water. These preliminary results indicate the need for increased sampling efforts evaluating the groundwater and human health impacts associated with shale gas extraction.