Book Description

Observations at the Elliott Bay disposal site on 24, 25 and 26 February 1976 were made of the descent of dredged material through the water column, the spreading velocity and thickness of the density surge over the bottom, and the drift of residual material introduced into the water column by the descending jet. Baseline bathymetry and postdisposal surveys were conducted by the U.S. Army Engineer District, Seattle, in order to determine the distribution and amount of disposed material on the bottom. In addition to these surveys, a 7.5-kHz subbottom profiler was used to detect the deposit of disposed material during the observation period. Dredging was done with a clamshell bucket into two split-hull scows and transported in tandem to the disposal site. The dredging location at the time of the observations was in the Duwamish Waterway between South Park Reach and the 14th Avenue Bridge Reach. Disposal operations were at a site in Elliott Bay less than 825 meter off the end of the dry docks in the West Waterway (See Figure J1 for index map of the area).