Estimation of riverine nutrient fluxes from an urban watershed in New Jersey

This study is to estimate the riverine nutrient (N and P) fluxes in Water Management Area (WMA) 7, New Jersey, as part of a larger project investigating potential relationships between land use/land cover, water quality, and demographics in northern New Jersey. Data collection and analysis were made based on historical data from the federal and state agencies such as the United States Geological Survey's water quality and flow measurement stations and the New Jersey Department of Environmental Protection. The area of interest includes the Elizabeth River in Passaic River Basin and the Rahway River in Rahway River Basin within Water Management Area (WMA) 7, located near the city of Newark and surrounding suburbs. Data from three USGS measurement stations (USGS # 01393450, 01394500 and 01395000) were selected and then joined to the geographic locations of the stations with ArcMap application from Esri. Readings for daily mean discharge and selected water chemistry measurements were analyzed to inform parameters for flux calculations. Five approaches to estimate nutrient flux, which were recommended by the Joint Group of Experts on the Scientific Aspects of Marine Pollution (GESAMP) under United Nations Educational, Scientific and Cultural Organization (UNESCO), were applied to the available data. Preliminary analysis shows that the average nutrient fluxes estimated from the five approaches at each sampling station range from 6,381 to 15,449 kg y^-1 for total organic nitrogen (TON), 27,837 to 52,532 kg y^-1 for total nitrogen (TN), and 6,113 to 15,815 kg y^-1 for total organic phosphorus (TOP), respectively. The results from this study provide a reference for nutrient fluxes from an urban watershed in northern New Jersey.