37 



5.0 CONCLUSIONS 



The July 1990 monitoring cruise at the Central Long Island Sound Disposal Site was 

 conducted to delineate the areal extent of the dredged material from the previous disposal 

 season and to monitor the recolonization status of the resident infaunal community. Distinct 

 dredged material mounds were formed at all buoy locations (CLIS-88, CLIS-89, and CS-90- 

 1), and dredged material was detected in all REMOTS® photographs around these disposal 

 locations. The REMOTS® photographs confirmed the recolonization predictions with Stage 

 III on inactive mound CLIS-88 and mostly Stage I on CLIS-89 and CS-90-1. 



As measured by bathymetry, the cap at CS-90-1 was thickest (20-100 cm) over the 

 main portion of the contaminated sediment mound. While much of the flank deposit had 

 20 cm or more of cap, other flank areas appeared to have less than 20 cm of cap. The 

 apparent cap thickness of less than 20 cm over these thin flank deposits occurs due to several 

 factors including compaction of the underlying deposits. To assure complete coverage of the 

 thinner cap areas, additional material should be directed to this mound during future disposal 

 operations. 



It appears that the use of multiple barge disposal points on capping projects of this 

 size or smaller should be reconsidered in favor of one central cap disposal point. 

 Alternatively, releasing material underway may have resulted in a more even distribution of 

 cap. Such operational modifications should be investigated in future capping projects. 



Monitoring Cruise at the Central Long Island Sound Disposal Site, July 1990 



