Discriminating Sources and Flowpaths of Anthropogenic Nitrogen Discharge to Florida Springs, Streams and Lakes. Environmental and Engineering Geoscience

Surface discharges of anthropogenic nutrients historically have been the focus of Florida’s water-quality regulations. Groundwater contributions to eutrophication of Florida’s surface waters are a more recent focus. Florida’s naturally oligotrophic springs, streams, and lakes are experiencing significant anthropogenic nutrient contamination resulting from groundwater discharges with elevated nitrate. Sour-ces of nitrate contamination to these surface-water ecosystems include sewage effluent, industrial animal waste (concentrated animal feedlot operations) and inorganic fertilizers. In this study, stable nitrogen isotope (d15N) analysis of freshwater macrophytes was combined with basic knowledge of watershed an