EXECUTIVE SUMMARY 



Science Applications International Coq^oration (SAIC) conducted a monitoring 

 survey at the Western Long Island Sound Disposal Site (WLIS) from 16 to 18 July 1996 

 aboard the M/V Beavertail as part of the Disposal Area Monitoring System (DAMOS) 

 Program. The field efforts were concentrated over the active southwestern quadrant of 

 WLIS and consisted of precision bathymetry and Remote Ecological Monitoring of the 

 Seafloor (REMOTS®). These surveying techniques were used to monitor the development, 

 stability, and benthic recolonization of the disposal mounds formed on the WLIS seafloor 

 from 1992 through 1996. 



Buoys have been deployed to control disposal operations within the boundaries of 

 WLIS since its selection as a dredged material disposal site in 1982 (WLIS III). Upon 

 receiving the first volumes of sediment dredged from coastal Connecticut and New York in 

 1982, WLIS has been monitored on a semi-annual basis for the US Army Corps of 

 Engineers, New England District (NED). Currently, a total of eight discrete disposal 

 mounds exist on the WLIS seafloor within an east-west trending seafloor depression that 

 extends through the center of the disposal site. The latest survey activity was concentrated 

 over the three most recent dredged material deposits, the WLIS H, WLIS G, and WLIS F 

 mounds, as well as the southern flank of the older WLIS D mound. 



The WLIS H mound is the most recent bottom feature formed within the boundaries 

 of WLIS. In September 1995, the WDA buoy was deployed at 40°59.228' N, 

 73°28.732' W and received approximately 15,300 m' of sands, silts, and clays dredged 

 from harbors and creeks along the Connecticut coast and the North Shore of Long Island, 

 New York, from 15 April to 29 May 1996. The deposition of this material resulted in the 

 formation of a 1.5 m high disposal mound, approximately 230 m in width. REMOTS® 

 sediment-profile photography detected a solid Stage I pioneering polychaete community 

 with some evidence of Stage III activity, as well as deep Redox Potential Discontinuity 

 (RPD) depths over the majority of the H mound. 



The WDA buoy was placed at 40°59.I58' N, 73°29.020' W, and received an 

 estimated barge volume of 52,500 m^ of sediment originating from coastal New York and 

 Connecticut, during the 1994-95 disposal season. The resulting dredged material deposit, 

 the WLIS G mound, was found to be 2.5 m high and connected to adjacent disposal 

 mounds (D and F) by a wide apron of dredged material. The infaunal population consists 

 mainly of Stage I individuals with some evidence of Stage III activity. Sediment-profile 

 photography also determined the RPD depths to be relatively deep, suggesting the area has 

 been free from the effects of seasonal hypoxia. 



The WLIS F mound is the product of modest dredged material deposition at WLIS 

 over a three-year period. The DAMOS disposal buoy WDA was positioned in nearly the 



