Robert W. Black Kathleen E. Conn 2014 Between February and June 2013, the U.S. Geological Survey collected representative samples of whole water, suspended sediment, and (or) bed sediment from a single strategically located site on the Duwamish River, Washington, during seven periods of different flow conditions. Samples were analyzed by Washington-State-accredited laboratories for a large suite of compounds, including polycyclic aromatic hydrocarbons and other semivolatile compounds, polychlorinated biphenyl Aroclors and the 209 congeners, metals, dioxins/furans, volatile organic compounds, pesticides, butyltins, hexavalent chromium, and total organic carbon. Chemical concentrations associated with bulk bed sediment (<2 mm) and fine bed sediment (<62.5 μm) fractions were compared to chemical concentrations associated with suspended sediment. Bulk bed sediment concentrations generally were lower than fine bed sediment and suspended-sediment concentrations. Concurrent with the chemistry sampling, additional parameters were measured, including instantaneous river discharge, suspended-sediment concentration, sediment particle-size distribution, and general water-quality parameters. From these data, estimates of instantaneous sediment and chemical loads from the Green River to the Lower Duwamish Waterway were calculated. application/pdf 10.3133/ds880 en U.S. Geological Survey Data compilation for assessing sediment and toxic chemical loads from the Green River to the lower Duwamish Waterway, Washington reports