An investigation was conducted on the environmental effects of open water dredged material disposal at the Eatons Neck Disposal Site in central Long Island Sound, New York. However, because of local political and public opposition to the dredging project, the field investigation was terminated after Phase I, a 12-month baseline survey of the disposal site and surrounding area. Phase I data, therefore, were used to describe environmental conditions at the Eatons Neck Disposal Site as they were four years after cessation of disposal operations. Dredged material, building rubble, and other materials were dumped at the site for about 70 years (1900 to 1971); 9,841,000 cu m of dredged sediments were placed at the site from 1954 to 1971. Results of hydrodynamic, bathymetry, and sediment studies showed no evidence of dispersion of dredged material from the site. Thus it appears that the Eatons Neck site is suitable, from a confinement standpoint, for the disposal of dredged sediments. Measured current velocities were typically