DETECTION OF APPALACHIAN BASIN BRINES IN THE TIOUGHNIOGA RIVER, CENTRAL NEW YORK

Environmental concerns regarding shale gas development include the potential for contamination of potable water sources. These concerns emphasize a need for the development of reliable and efficient means to distinguish waters influenced by Appalachian Basin Brines from other shallower sources (e.g. road salts and animal waste) and the establishment of baseline water quality data. Iodine, as a sensitive tracer, can be a useful tool in detecting the influence of organic rich shale in natural waters. A moratorium currently exists in New York State, prohibiting shale gas development by means of high-volume hydraulic fracturing, thus providing a favorable area to establish baseline water quality measurements. The Tioughnioga River is a major headwater to the Upper Susquehanna River Basin, the main watershed in central New York and Pennsylvania. Water samples were collected weekly at the East and West Branches of the Tioughnioga River from 2012 to 2014. Samples were analyzed for major ions using Ion Chromatography, for I^- and Br^- on ICP-MS, and for δ²H and δ¹⁸O on a Picarro Water Isotope Analyzer. ­The purpose of this study is to differentiate waters impacted by Appalachian Basin brines. We use of the unique chemical ratios of halogens (I^-, Br^-, and Cl^-) and mixing relationships to determine whether Appalachian Basin Brines are present in tributaries and shallow groundwater. As an independent method, we applied a multivariate statistical model to effectively distinguish contaminant sources. Our data suggest that deep subsurface brines are mixing with shallow groundwater and discharging to tributaries. This work has implications for establishing baseline water quality in surface water and future monitoring practices concerning shale gas production in the Appalachian Basin.