IDENTIFICATION AND QUANTIFICATION OF BASIN BRINE AND ROAD SALT SOURCES IN STREAMS ALONG THE NEW YORK / PENNSYLVANIA BORDER

Produced water from hydraulic fracturing of the Marcellus Shale has generated considerable concern for the potential of high Total Dissolved Solids (TDS) contamination to water resources, which highlights the need for watershed based water quality measurements pre, during, and post drilling operations. In addition to potential natural gas extraction sources, the application of road salt can be a major source of high TDS to streams throughout the northeastern United States. 300 samples were collected from 10 stream locations within 4 adjacent watersheds along the NY/PA border, to determine geochemical trends from watersheds containing differing amounts of road salt applications and drilling activities. Inorganic cation and anion ratios, including Cl/Br and (Ba+Sr)/Mg, were used to chemically distinguish between six reference sites, three sites impacted by basin brine sources, and one site by road salt sources. Geochemical mixing models combined with numerous measurements of surface discharge from a natural brine source at Salt Springs State Park, PA allowed for quantification of the brine discharge rate into adjacent streams, and demonstrated the applicability of using inorganic cation and anion ratios to identify and quantify small additions (0.01-0.001%) of high TDS contaminants under varying flow conditions. The magnitude of current high TDS brine inputs in these headwater streams is small relative to road salt impacted streams in more traveled areas, increasing the likelihood for detecting future additions of high TDS contaminants from continued monitoring in rural watersheds. Water quality analysis combining cation and anion metrics could serve as a basis for the classification and quantification of pre-as well as post natural gas drilling brine contaminant levels, which would assist stakeholders in short and long term water quality assessments.