Analyses of elutriates, native water, and bottom material in selected rivers and estuaries in western Oregon and Washington

Chemical analyses of elutriates, bottom sediment and water samples for selected metals, nutrients and organic compounds including insecticides and herbicides have been made to provide data to determine short-term water quality conditions associated with dredging operations in rivers and estuaries. Between May and December 1980 data were collected as far south as the Coos River in Western Oregon, as far north as Baker Bay in Southwestern Washington and as far inland as Bonneville Dam on the Columbia River. In an elutriation test, bottom material from a dredging site is mixed with native water and the filtrate is analysed. Elutriation test results showed variability in concentrates of dissolved chemicals as follows: in micrograms per liter (micro g/l), manganese ranged from 0 to 10,000, iron from 10 to 4300, zinc from 1 to 90, and phenols from 9 to 420; in milligrams per liter (mg/l), ammonia as nitrogen ranged from 0.03 to 46 and organic carbon from 0.5 to 45. (USGS)