Bathymetric Survey of the New London, Connecticut Dredge Spoil Dump Ground

The current concern for the environment of local waters has caused a reevaluation of the effects of dumping dredge spoil in local waters that are used for recreational and commercial purposes. A COE approved dumping grounds at the confluence of the Thames River, CT. and Long Island Sound has been used to dispose of the dredge spoil obtained by deepening the river channel to a depth suitable to accommodate the Navy´s new 688 class submarine. This paper describes a dual frequency bathymetric profiling method used to survey the spoil that has been dumped to determine if there has been any material transported from the dump site by local currents. The method provided an accurate description of the dump site as well as an accurate estimate of the volume of spoil dumped. The survey indicated that approximately 95% of the discharged material remained within the dump site.