5£ 



The Eaton's Neck, South Norwalk, and Stamford disposal sites continue to be of 

 particular significance given their position relative to the WLIS III boundaries (Figure 4- 

 3). Historic disposal operations were not required to observe the guidelines which 

 currently apply to sediment deposition through the Interim Plan (NERBC 1980) and the 

 DAMOS Program. The lack of a requirement for precision positioning during disposal 

 operations allowed dredged material to be disposed throughout the established sites as 

 scattered, discrete sediment deposits. As a result, the detection of relic dredged material 

 within the WLIS reference areas is possible, even following their careful selection. 



The DAMOS tiered monitoring protocol requires the status of the benthic 

 enviroimient within an area of dredged material disposal to be analyzed relative to the 

 regional conditions as characterized by the reference area REMOTS® data. However, the 

 multitude of historic dredged material disposal sites and the lack of suitable areas with 

 ambient material at the sediment- water interface has complicated this process at WLIS. 



Reference area comparisons are used to ground-truth sediment-profile photography 

 results (SAIC 1987). Poor benthic conditions attributed to seasonal hypoxia, a period of 

 reduced dissolved oxygen concentrations, at WLIS-REF during the August 1985 and 

 August 1986 surveys prompted the use of additional sites for comparison. Four new 

 reference areas (3000E, 2000W, 2000S, and 2000N) were utilized during a DAMOS 

 monitoring cruise in November 1987 to compare benthic community structure, body 

 burden, and sediment chemistry (Figure 4-3). Stations 2000W and 2000S were accepted as 

 useful reference areas. However, the physical appearance and chemical composition of the 

 sediments collected at 2000N and 3000E were indicative of anthropogenic activity and did 

 not support their use as WLIS reference areas (SAIC 1990a). 



During 1991 survey, REMOTS® imagery and chemical analysis of the sediments 

 collected from reference areas WLIS-REF and 2000S detected the presence of relic 

 dredged material and elevated PAH and trace metals concentrations. It was determined 

 that these discoveries were linked to the historic disposal operations in the region. The use 

 of WLIS-REF and 2000S as reference areas were discontinued, with subsequent survey 

 efforts attempting to define two new reference areas free from the effects of anthropogenic 

 activity. Reconnaissance surveys of prospective reference areas cannot guarantee the 

 absence of historical dredged material. As reference areas are used and additional data are 

 collected, previously undetected historical material may be sampled. 



In 1992, more detailed physical and chemical analysis of western Long Island 

 Sound sediments led to the acceptance of reference area SOUTH (40°58.688' N latitude, 

 73°29.20r W longitude) as a replacement for 2000S. A second prospective reference 

 area, EAST (alternate to WLIS-REF), was utilized for comparison widi WLIS sedhnents 

 once (in 1992) before being abandoned due to the subsequent discovery of relic dredged 



Monitoring Cruise at the Western Long Island Sound Disposal Site, July 1996 



