The application of road salt in an urban watershed leads to increased sodium and chloride concentrations in surface water and groundwater, which can adversely affect aquatic ecosystems, and may have consequences for soil cation exchange. This study focuses on the spatial and temporal variations in sodium and chloride concentrations in Patroon Creek, Albany County, New York, a tributary of the Hudson River. For two years, weekly surface water samples were gathered from 7 sites along Patroon Creek for major ion concentrations as measured by ion chromatography. Additionally, a USGS gage on Patroon Creek measures specific conductivity, water temperature, stage, and discharge in 15 minute intervals. Sodium and chloride concentrations in the creek are highest at all sampling sites in winter months, and near large parking lots and areas with high road density. However, concentrations remain elevated throughout the year with respect to natural background levels. Mean chloride concentration is 224 ppm (n = 644). Sodium and chloride in the creek water are a result of halite road salt application in the watershed, which is evidenced by the rapid rise in sodium and chloride concentrations in the creek during winter storm events, and the high correlation between sodium and chloride in the water (sodium to chloride ratio in mEq = 0.94:1, R2 = 0.95, n = 578). Roughly one-third of the 37 km2 watershed is covered by impervious surfaces, suggesting that much of the road salt applied to the watershed is washed directly into Patroon Creek. This study attempts to create a mass-balance of inputs and outputs of halite salt to and from the Patroon Creek Watershed system. Inputs of sodium and chloride include road salt application, groundwater baseflow input, and input from precipitation. Outputs include discharge of salt by Patroon Creek to the Hudson River, output from a combined sewage overflow system, and loss to groundwater recharge. The budget does not balance perfectly; there seems to be a net gain of salt to the system.
Erickson, E.K., 2004. Road salt application and its effects on
sodium and chloride ion concentrations in an urban stream Patroon
Creek, Albany, NY.
Unpublished MSc. thesis, State University of New York at Albany. 83 pp., + ix
University at Albany Science Library call number: SCIENCE Oversize (*) QE 40 Z899 2004 E75
thesis (scanned text) - 15.1MB pdf file
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