MIT Department: Civil and Environmental Engineering
My name is Nathalie Thelemaque and I am a rising senior at the University of Florida majoring in Civil Engineering. My passion greatly involves the promotion of sustainability practices within the engineering discipline, especially within the design and developments of steel and composite structures for construction. I hope to one day use my varied experiences to help rebuild the infrastructure of countries undergoing strife using efficient and sustainable methodologies. In my spare time, I can be found enjoying the arts, learning new things, or pointing out construction cranes.
2019 Research Abstract
Groundwater Methane Concentration in Relation to Hydraulic Fracturing Above the Marcellus Shale
Nathalie Thelemaque1, Nicolette Bugher2, Yunpo Li3, and Desiree Plata4
1Department of Civil and Coastal Engineering, University of Florida
2Department of Civil and Environmental Engineering, University of Delaware
3,4 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology
While the focus of many current global warming countermeasures is on carbon dioxide and its effects on climate, methane has a much higher global warming potential. Fugitive methane emissions from natural gas extraction processes are poorly constrained. In terms of groundwater, methane can originate from either biogenic sources (i.e., anaerobic microbial activity) or thermogenic sources (i.e., natural gas). Here, we analyzed well water samples from the region of the Marcellus Shale formation in Pennsylvania using a headspace equilibrium approach. Specifically, drinking water samples were collected in azide-sterilized serum bottles. Subsequently, we injected methane-free helium headspace, allowed the dissolved hydrocarbons (methane, ethane, and propane) to equilibrate with that helium, and then quantified those species using a gas chromatograph. From the 2018 field samples, we found that most groundwater contained low hydrocarbon level with the exception of a small number (approximately 5%) of outliers. No statistically significant relationship between dissolved methane concentrations and proximity to the nearest unconventional oil and gas well was observed. Moreover, the methane-to-higher-chain-hydrocarbon ratio indicated the dominant source of methane in originated from biogenic activity. Future studies could use isotopic analysis to further delineate the source of methane in these groundwaters, and ongoing calculations will estimate the total contribution of groundwater methane to atmospheric greenhouse gas budgets. Overall, these results indicate that there is no systematic methane contamination of home drinking water wells as a result of hydraulic fracturing activity in this region of the United States.