In 1988, a new strategy for managing the sediments deposited at CLIS was 

 instituted. Utilizing the ten-year dredging cycle for large federal projects that exist in the 

 central Long Island Sound region, NED controlled the deposition of small to moderate 

 volumes of dredged material, forming a disposal mound ring (Morris et al. 1996). Upon 

 completion in 1992, this network of disposal mounds formed an artificial containment cell 

 that was capable of accepting a large volume of UDM, limiting the lateral spread of the 

 deposit and facilitating efficient capping operations (Figure 1-2). During the 1993/94 

 disposal season, this containment strucmre was utilized for the disposal of approximately 

 1,159,000 m^ of material dredged from New Haven Harbor. 



From October 1993 to February 1994 Great Lakes Dredging Company conducted a 

 large scale disposal and capping operation at CLIS as part of the New Haven Harbor 

 Capping Project (Morris et al. 1996). An estimated barge volume of 590,000 m^ of 

 material classified as UDM was dredged from inner New Haven Harbor, as well as five 

 private marine terminals, and deposited in close proximity to the "NHAV" buoy 

 (41°09.122' N, 72°53.453' W). The UDM was subsequently capped with an approximate 

 barge volume of 569,000 m^ of CDM dredged from the outer New Haven Harbor, 

 resulting in a flat, stable CAD mound with a CDM to UDM ratio of 0.96:1.0. Upon 

 completion of the disposal and capping operations in March 1994, the NHAV 93 mound 

 displayed a height of 2.5 m and an overall diameter of approximately 820 m (Morris et al. 

 1996). 



A variety of smaller dredging projects along the coast of Connecticut during the 

 1993/94 disposal season generated approximately 65,000 m^ of material for subaqueous 

 disposal at CLIS. Barges were directed to the "CDA" taut-wired buoy (41°08.637' N, 

 72°53.859' W) deployed over the MQR mound in September 1993. The MQR mound is a 

 capped mound in the southwest quadrant of the disposal site. This bottom feature is 

 acmally composed of several alternating layers of UDM and CDM deposited during the 

 1981/82, 1982/83, and 1993/94 disposal seasons. 



In the spring of 1982, an estimated barge volume of 42,000 m^ of UDM was 

 dredged from the Mill River and placed on a relatively flat area of CLIS seafloor. The 

 UDM deposit was quickly capped with approximately 133,200 m^ of CDM removed from 

 the Quinnipiac River. During the 1982/83 disposal season, in conjunction with the US 

 Environmental Protection Agency (EPA) and the US Army Corps of Engineers, 

 Waterways Experiment Station (WES) Field Verification Program (FVP), an additional 

 67,000 m^ of UDM from Black Rock Harbor was released over the MQR mound. The 

 Black Rock Harbor material was followed by 400,000 m' of CDM originating from a 

 project in New Haven Harbor (SAIC 1995). 



Monitoring Cruise at the Central Long Island Sound Disposal Site, July 1994 



