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6.1 CENTRAL LONG ISLAND SOUND DISPOSAL SITE 



6.1.1 Summary of CLIS 



The Central Long Island Sound Disposal Site (CLIS) is located 5.6 nmi south of 

 South End Point in East Haven, Connecticut. The site is 2 nmi by 1 nmi and is centered at 

 41°08.95' N, 72°52.85' W (Figure 6-1). The ambient water depths at this site range from 

 17.5 to 22.5 m with the peaks of some of the disposal mounds as shallow as 14.0 m. Since 

 1984, five disposal mounds have been created at CLIS: CLIS-86, CLIS-87, CLIS-88, CLIS- 

 89, and CS-90-1. A 1200 x 1200 m area of CLIS, surveyed in 1990, showed the four most 

 recent mounds (Figure 6-2). This site has been utilized primarily for the disposal of dredged 

 material from the New Haven area, but also from areas as distant as Stamford and Norwalk 

 Harbors. The energy regime at CLIS is dominated by tidal currents running in an east-west 

 direction. A southerly component introduced by the Quinnipiac River between West and 

 East Haven is more pronounced during periods of spring runoff. This low energy regime is 

 reflected in the ambient fine silt and clay sediments. The incidence of storm-driven, wave- 

 induced currents at CLIS is reduced considerably due to the restricted fetch available at the 

 site. Only the most severe northeast storms have any appreciable effect (SAIC 1988a). 



There is little finfishing activity inside the site with the exception of lobstermen 

 trawling for bait and an occasional trawler fishing for scup. The nearest leased oyster 

 grounds are approximately 3 miles north of this site. 



Six monitoring cruises were conducted at CLIS by scientists from SAIC since 1984 

 (SAIC 1989a, 1990a, 1990b, 1990c, Germano et al. 1994). These studies assessed the 

 stability of the dredged material disposed in the area and any potential adverse environmental 

 effects. CLIS has been studied closely over the years, using many of the proven disposal 

 assessment techniques developed in the DAMOS Program. These included precision 

 bathymetric and side-scan sonar surveys, remote sensing such as underwater television 

 observations and the REMOTS® sediment-profile camera, and sediment sampling for 

 chemical, physical, and benthic community analysis. This site was studied extensively using 

 innovative techniques such as the DAISY in situ multiparametric array. The Field 

 Verification Program (FVP) disposal mound in the northeast corner of CLIS was studied 

 intensively until 1988 as part of the Field Verification Program for the US Army Waterways 

 Experiment Station and the US Environmental Protection Agency (EPA). The program was 

 designed to determine the applicability, reproducibility, and field verification of test methods 

 for the evaluation of the effects of dredged material disposal (Gentile 1988). In addition to 

 regularly scheduled surveys, a monitoring cruise was conducted immediately following the 

 occurrence of Hurricane Gloria in 1985 (SAIC 1989a). During this study, it appeared that 

 the storm produced local redistribution of sediment at some of the disposal mounds but no 

 major transport of dredged material out of the disposal site boundaries. 



DAMOS Summary Report, 1985-1990 



