EXECUTIVE SUMMARY 



Science Applications International Corporation (SAIC) conducted monitoring 

 surveys. of the New London Disposal Site (NLDS) in August 1992; August 1995; 

 September 1997; and July 1998, as part of the Disposal Area Monitoring System 

 (DAMOS) Program. Field operations in each survey year included data collection of one 

 or more of the following: precision bathymetric surveys, Remote Ecological Monitoring 

 of the Seafloor (REMOTS®) sediment-profile surveys, and surface and near-bottom 

 dissolved oxygen determinations. 



Since its inception in 1977, the Disposal Area Monitoring System (DAMOS) 

 Program has investigated dredging and dredged material disposal practices in an effort to 

 minimize adverse physical, chemical, and biological impacts. DAMOS utilizes a flexible, 

 tiered management approach centered around comprehensive environmental monitoring to 

 oversee the placement of sediments at nine open water disposal sites along the coast of 

 New England. Active disposal sites are surveyed on a regular basis to ensure the effects of 

 dredged material disposition on the benthic habitat are localized and temporary. 



There has been an active dredged material disposal site near New London since at 

 least 1955. DAMOS monitoring of the New London Disposal Site started in 1977 when 

 the program was established. In 1996, the boundary of the New London Disposal Site 

 shown in DAMOS graphics was shifted in accordance with the Final Programmatic 

 Environmental Impact Statement, resulting in a 0.2 nmi northerly shift of the disposal site. 

 The new, northern region was surveyed in 1997. 



The New London disposal site has been used for on-going disposal throughout the 

 1990's, including unconfined disposal of suitable sediments, and capped disposal of 

 unsuitable sediments. This report summarizes the disposal and monitoring activities 

 conducted from the 1991-1992 dredging season through monitoring in July 1998. This 

 information is presented as a single report to provide a clear, concise picture of use of the 

 New London Disposal Site during this time frame and to include important monitoring 

 information related to the dredged material mounds. 



During the 1991-1992 disposal season, the NLDS received a total barge volume of 

 104,200 m 3 of dredged material generated from four separate projects in the eastern Long 

 Island Sound region. Disposal resulted in creation of two disposal mounds, the 

 Dow/Stonington (D/S) mound, consisting of unsuitable dredged material (Dow and 

 Stonington sediments) and suitable cap material (Dow sediments), and the NL-91 mound 

 immediately north of the D/S mound. 



Bathymetric surveys and REMOTS® data, which were fully developed using pre- 

 and post-cap bathymetric survey data analyzed in 1994-1995, showed that due to errors in 

 navigation, while some cap material covered the D/S mound, most of the cap material was 



