FY 1984

Sources and transport of hydrocarbons in the Green-Duwamish River, Washington

Hamilton, S.E., T.S. Bates, and J.D. Cline

Environ. Sci. Technol., 18(2), 72–79, doi: 10.1021/es00120a004 (1984)

Hydrocarbon concentrations were measured in the suspended matter and sediments of the Green-Duwamish River, Washington (1978–1981), in an effort to document the sources, transport, and fate of these organic compounds in a tractable estuary. Hydrocarbon derived from algae, plant waves, highway runoff, a secondary sewage treatment plant, and sedimentary sources were distinguished from each other. Hydrocarbon transports were calculated at each station. Dilution with pristine particulates and/or particulates associated with highway runoff accounted for transport disparities between stations encompassing no known point sources of hydrocarbons. Compositional effects of the sewage effluent were observed, but the transport budget could not account for the hydrocarbons contributed by the outfall. Organic matter appears to flocculate and sediment as effluent mixes with river water. This organic-rich layer may be mobilized only during periods of high discharge.