A GEOCHEMICAL ANALYSIS OF CHARLOTTE CREEK WATERSHED, NEW YORK

Charlotte Creek watershed is a highly forested agricultural area that drains into the Susquehanna River in New York State that ultimately runs to the Chesapeake Bay. This watershed is located north of the New York City drinking water supply area in Delaware County; thus, it is less studied. The purpose of this project was to characterize and monitor the chemical composition of Charlotte Creek and its tributaries. Water samples were collected at 11 sites six times between the fall of 2019 and 2022 during baseflow conditions to help understand spatial and temporal variations within the watershed. Field parameters such as pH, temperature, electrical conductivity, and dissolved oxygen were measured on-site. Turbidity as a proxy for suspended sediment concentration was measured upon arrival at the laboratory. Then samples were filtered and preserved for cation and anion analysis, which was conducted by atomic absorption spectroscopy and ion chromatography, respectively. The general geochemical signature of the watershed reflected the bedrock geology and the water was found to be mainly a calcium-bicarbonate-type of water with magnesium-sulfate-type being the secondary component. The human influence of road salt applications was detected after the main tributaries, Middle Brook and Kortright Creek, entered the main stem and supplied a significant amount of sodium-chloride-type water into the main stem of Charlotte Creek. However, the water quality of Charlotte Creek is good during baseflow conditions and all tested parameters read below the maximum allowed and recommended quality standard values of the US-EPA.