IDENTIFYING THE SOURCE OF EXCESS FINE-GRAINED SEDIMENTS IN NEW JERSEY RIVERS USING RADIONUCLIDES

Fine-grained sediment is a major pollutant in streams and lakes, affecting feeding and reproduction of aquatic animals, aesthetics, recreation and water supply. One barrier to controlling sediment load is that it is often difficult to determine whether the source of sediment is widespread but shallow surficial erosion from overland flow occurring in the watershed or from the erosion of channel bank material. However, these two sources of sediment should be identifiable by their different radionuclide signatures, including ⁷Be, ²¹⁰Pb, and ¹³⁷Cs. We propose to sample channel bank material, watershed soils, in-stream fine sediment, and suspended sediment and analyze them for their radionuclide signature to investigate how well one can identify the relative contributions of sediments from the watershed and channel banks. This knowledge will allow for improved stream and watershed management and the possible initiation of sediment-reduction programs.