Water and gas samples were collected from (1) nine shallow groundwater aquifers overlying Marcellus Shale in north-central West Virginia before active shale gas drilling, (2) wells producing gas from Upper Devonian sands and Middle Devonian Marcellus Shale in southwestern Pennsylvania, (3) coal-mine water discharges in southwestern Pennsylvania, and (4) streams in southwestern Pennsylvania and north-central West Virginia. Our preliminary results demonstrate that the oxygen and hydrogen isotope composition of water, carbon isotope composition of dissolved inorganic carbon, and carbon and hydrogen isotope compositions of methane in Upper Devonian sands and Marcellus Shale are very different compared with shallow groundwater aquifers, coal-mine waters, and stream waters of the region. Therefore, spatiotemporal stable isotope monitoring of the different sources of water before, during, and after hydraulic fracturing can be used to identify migrations of fluids and gas from deep formations that are coincident with shale gas drilling.

Editorial handling by A. Kolker a b s t r a c t Stable isotopes were used to determine the sources and fate of dissolved inorganic C (DIC) in the circumneutral pH drainage from an abandoned bituminous coal mine in western Pennsylvania. The C isotope signatures of DIC (d 13 C DIC ) were intermediate between local carbonate and organic C sources, but were higher than those of contemporaneous Pennsylvanian age groundwaters in the region. This suggests a significant contribution of C enriched in 13 C due to enhanced carbonate dissolution associated with the release of H 2 SO 4 from pyrite oxidation. The Sr isotopic signature of the drainage was similar to other regional mine waters associated with the same coal seam and reflected contributions from limestone dissolution and cation exchange with clay minerals. The relatively high d 34 S SO4 and d 18 O SO4 isotopic signatures of the mine drainage and the presence of presumptive SO 4 -reducing bacteria suggest that SO 4 reduction activity also contributes C depleted in 13 C isotope to the total DIC pool. With distance downstream from the mine portal, C isotope signatures in the drainage increased , accompanied by decreased total DIC concentrations and increased pH. These data are consistent with H 2 SO 4 dissolution of carbonate rocks, enhanced by cation exchange, and C release to the atmosphere via CO 2 outgassing.

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Geography for giving me the opportunity to continue my education and providing me with the support to do so. Additionally, I would like to thank the DOE/NETL for providing me the funds to carry out my research. My experience would not have been the same without my fellow graduate students and lab workers, so thanks for the help and support. Finally, to my close friends and family for encouraging me to keep motivated and working hard throughout the years.