title: Chloride sources in urban and rural headwater catchments, central New York.
abstract: Road salt used as a deicing agent in winter months has become an emerging contaminant to streams and groundwater. In central New York, road salts are applied heavily during winter months. Recognizing potential sources of salinity to a river may reveal processes controlling the salinization of freshwater systems, with implications for future management practices. The Tioughnioga River, located in central New York, is a headwater of the Susquehanna River, which flows into the Chesapeake Bay. Salinity of the Tioughnioga River water has been increasing since the late 1930s. In this study, water samples were collected weekly at the East and West Branches of the Tioughnioga River from 2012 to 2014. We characterize natural and anthropogenic sources of salinity in the Tioughnioga River, using two independent approaches: (1) chloride to bromide ratios (Cl/Br) and (2) linear discriminant analysis. Ratios of Cl/Br suggest that road salt runoff influence is notable in both branches, but is more significant in the West Branch, consistent with a greater area of urban land. Linear discriminant analysis confirms the results of Cl/Br in the West Branch and further indicates presence of Appalachian Basin Brines in the East Branch, although their contribution may be volumetrically small. Longitudinal stream Cl concentration profiles indicate that sources of pollution are particularly concentrated around urban areas. Residence time of Cl in the watershed is estimated to be approximately 20 to 30years using a mixing model, suggesting that stream Cl concentrations likely will continue to rise for several decades.
authors.affiliation: Syracuse University, Department of Earth Sciences, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States. Electronic address: kmgutche@syr.edu.
authors.forename: Kristina
authors.initials: K
authors.lastname: Gutchess
authors.affiliation: Geology Department, State University of New York College at Cortland, Cortland, NY 13045, United States.
authors.forename: Li
authors.initials: L
authors.lastname: Jin
authors.affiliation: Syracuse University, Department of Earth Sciences, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States.
authors.forename: Laura
authors.initials: L
authors.lastname: Lautz
authors.affiliation: Department of Environmental Resources Engineering, College of Environmental Science and Forestry, State University of New York, Syracuse, NY 13244, United States.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Shaw
authors.affiliation: Syracuse University, Department of Earth Sciences, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Syracuse University, Department of Earth Sciences, 204 Heroy Geology Laboratory, Syracuse, NY 13244, United States.
authors.forename: Zunli
authors.initials: Z
authors.lastname: Lu
mesh_terms: D001965:Bromides / Q000032:analysis*; D002712:Chlorides / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis*; D060587:Groundwater / Q000032:analysis*; D009518:New York; D012424:Rural Population; D054712:Salinity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001965:Bromides; D002712:Chlorides; D014874:Water Pollutants, Chemical
keywords: Bromide; Chloride; Groundwater; Linear discriminant analysis; Road salt