10 



western flank. The USCGA Mound was laterally confined by the NL-RELIC Mound to 

 the west and the NL-II Mound to the east (Figure 1-3). The NL-94 Mound was formed 

 when 8,700 m 3 of UDM from Pier 15 at the U.S. Navy Submarine Base was released at 

 the NDA-94 buoy (41°16.270' N, 72°04.890' W). This UDM, which was released 

 between 26 December 1994 and 5 January 1995, was covered by 28,200 m 3 of CDM 

 between 17 January and 14 February 1995. The southern flank of the NL-94 Mound abuts 

 the historic NL-I Mound. 



In addition to the material disposed at the NL-94 Mound during the 1994-95 

 disposal season, additional material was placed in this location during the 1996-97 disposal 

 season. In September 1996, a disposal buoy (NDA-96) was deployed at 41° 16.234' N, 

 72° 05.912' W (41° 16.228' N, 72° 04.941 ' W; NAD 27), approximately 80 m west- 

 southwest of the NDA-94 buoy location (Figure 1-2). An estimated barge volume of 3,400 

 m 3 of material dredged from the Niantic River as well as Gales Ferry Marina in the 

 Thames River was deposited at the NDA 96 buoy, to add to the existing NL-94 Mound. 



1.3 Monitoring Activity 



1.3.1 August 1992 Monitoring Survey 



SAIC conducted a monitoring survey at NLDS from 7 to 9 August 1992 as part of 

 the DAMOS Program. The field efforts were concentrated over the central region of the 

 disposal site and consisted of precision bathymetry, Remote Ecological Monitoring of the 

 Seafloor (REMOTS®) sediment-profile photography, and dissolved oxygen (DO) 

 measurements to provide information on the effects of the sediment deposition that 

 occurred in 1991-1992. 



The objectives of the August 1992 New London Disposal Site survey were to 



• delineate the extent and characterize the topography of recently deposited 

 dredged material around the Dow/Stonington and NDA disposal points since the 

 June 1991 survey; 



• assess the recolonization status of benthic biota and determine the spatial limits 

 of the recently deposited sediment; 



• determine near-bottom and surface dissolved oxygen concentrations at the active 

 disposal mound and reference areas. 



Monitoring Cruise at the New London Disposal Site, 1992 - 1998 



