On 27 November 1991, the NDA buoy was re-positioned at 41° 16.251' N, 

 72°04.497' W (NDA #2). A second, smaller buoy, "D/S", was placed 175 m south of 

 NDA #2 at coordinates 41° 16. 162' N, 72°04.468' W (Figure 1-3; Appendix A, Table 1). 

 From 28 November to 12 December 1991, 3,100 m 3 of additional material from Gwen 

 Mor Marina and Port Niantic, Inc. were deposited at the second NDA buoy location 

 (Appendix Al). 



The D/S buoy was deployed in support of a sediment capping project, marking the 

 deposition point for material generated from dredging operations at Stonington Harbor, 

 CT, and the Dow Chemical Company's Allyns Point Plant in Gale's Ferry, CT. During 

 the Dow/Stonington capping project, disposal of UDM commenced on 2 December 1991 

 and continued through 12 December 1991. Within those 10 days, an estimated barge 

 volume of 12,000 m 3 of material from Stonington Harbor, as well as 24,000 m 3 of dredged 

 material from Dow Chemical Company's Allyns Point facility, was deposited in close 

 proximity to the D/S buoy (Appendix A2). Upon conclusion of UDM deposition, a precap 

 bathymetric survey was performed for the Dow Chemical Company by Ocean Surveys 

 Incorporated (OSI) of Old Saybrook, Connecticut. 



The detected UDM deposit was then targeted for capping with an estimated barge 

 volume of 59,300 m 3 of CDM from the Dow Chemical project. A series of seven capping 

 points (A-G) were developed to control the CDM dispersal pattern in order to efficiently 

 cover the 36,100 m 3 of UDM to a desired sediment cap thickness of 50-100 cm. 

 However, due to an apparent error, the positions of the seven capping points were 

 misinterpreted. As a result, cap material was released both over the mound and east of the 

 initial D/S sediment deposit. On 15 January 1992, capping operations were concluded, 

 and a postcap bathymetric survey was conducted in August 1992. 



At the conclusion of the capping project, the disposal buoys were scheduled to be 

 repositioned at the request of the U.S. Coast Guard and the U.S. Navy. The U.S. Coast 

 Guard stated that U.S. Navy vessels frequently transit through the area and the disposal 

 buoys posed a hazard to navigation. The NDA buoy was repositioned on 22 January 1992 

 at 41°16.252' N, 72°04.756' W, a position outside a newly designated U.S. Navy 

 shipping lane (NDA #3; Figure 1-3). The smaller D/S buoy, which was scheduled for. 

 removal from NLDS, was not found in the area. It is believed that the D/S buoy was 

 removed from the site by a U.S. Navy submarine passing through NLDS on approximately 

 14 January 1992. 



The NDA buoy was repositioned, again at the U.S. Navy's request, on 10 April 

 1992, to its final location of 41° 16. 163' N, 72°04.996' W, 475 m west of the U.S. Navy 



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



