data will also provide information as to where sampling should be conducted to obtain 

 samples of organisms living on the spoils. The bathymetric data will not yield information 

 on whether clean spoils have been capped, intermixed with or displaced underlying material. 

 The resolution of acoustic data is not sufficient to delineate the margins of the spoil mounds. 

 In situ observation and samples taken by divers will supplement the remote measurements. 



The major problem associated with diver operations is navigation control. Limited 

 visibility and the lack of undersea to surface communications hamper diving studies in New 

 England waters, interfering with precision or replicate sampling procedures. This problem 

 will be solved by using microwave navigation equipment to deploy a wire on the bottom. 

 The wire will be 400 meters long and centered 25 meters south of the disposal buoy 

 designated for the mud-capped pile. This wire will be oriented east-west and will have 

 polypropylene line spliced at specific distances from the middle to designate sample locations 

 based on a logarithmic distribution. 



These sample locations will be spaced at distances of 25, 29, 36, 47, 64, 92, 136, and 

 206 meters from the middle of the wire. At each location a calibrated stake will be installed 

 to anchor the wire and provide a means of measuring sediment accumulation. 



Two additional stations near the ends of the wire will be sampled by spot dives as 

 controlled by the navigation system. At these distances changes in the distribution of spoils 

 should be minimal and precise replication of sample stations less important. 



An acoustic release and pinger will be placed at the 206 meter station and divers will 

 start at this location and swim towards the center. At each station three 20 cm cores will be 

 obtained for heavy metal analysis; visual observations of the sediment stakes will be obtained 

 and photographs taken. 



The wire itself may act as a measure of spread of the spoils inasmuch as the margin 

 of the mound may be identified by the proportion of the wire that is covered. The stakes and 

 the polypropylene line should enable divers to ascertain sample locations as they approach 

 the disposal point location despite cover of the wire. 



Sampling and analysis for metal content of the cores obtained by the divers appears to 

 be the most definitive approach to determining the extent of coverage, intermixing, or 

 displacement of Stamford spoils by New Haven material. 



Grab samples for chemical analysis taken from on board ship will be obtained at 

 distances farther removed form the disposal points. 



Twenty eight separate diver stations at the mud-capped site will require at least two 

 days to sample because of distances that must be travelled and restrictions on bottom time in 

 repetitive dives. Fewer samples should be required at the sand site to define the sediment 

 cover because of the small amount of materials involved and their sharp lithological 

 differences. 



