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4.2 New Reference Area Investigation at SE-REF 



Reference areas are necessary for assessing the environmental impacts of dredged 

 material disposal and for classifying the suitability of dredged material for disposal through 

 the permit evaluation process. Selection of a reference area is based on proximity to the 

 disposal site, sediment chemistry, and similar water depths and grain size (EPA and 

 USAGE 1991). Reference sediments should be representative of ambient conditions and 

 free of historic dredged material or other unnamral contamination or dismrbances (EPA 

 and USAGE 1997). Reference areas provide a control region of ambient conditions for 

 comparison with results of sediment-profile photography and geochemistry analyses at the 

 disposal mounds. 



Disposal operations before 1977 occurred throughout Long Island Sound both in the 

 historic disposal sites and the surrounding regions. From 1954 to 1972, an estimated total 

 of 22 million cubic yards of dredged material was disposed at eight sites in western Long 

 Island Sound, with sixty percent (13.2 million cubic yards) at Eaton's Neck which is close 

 to WLIS (Fredette et al. 1993). Since 1983, dredged material disposal has been directed to 

 positioned buoys in the southwestern quadrant of WLIS and has been carefully monitored 

 and managed. 



During monitoring surveys, the benthic conditions at disposal mounds are compared to 

 observations of ambient sediments at reference areas. Although three reference areas are 

 required according to DAMOS protocol, only two reference areas, SOUTH and SW-REF, 

 currently qualify to represent ambient conditions. 2000W was the latest reference area to be 

 discontinued due to the detection of historic dredged material in many REMOTS® replicates 

 during monitoring surveys (Morris 1998). Low DO conditions and methane bubbles were 

 observed in the area both in 1992 and 1996. Figure 1-2 displays the location of 2000W, 

 which is within the boundaries of the historic Stamford Disposal Site, in addition to five other 

 discontinued reference areas relative to WLIS. All six have been abandoned due to the clear 

 evidence of dredged material. In addition, REMOTS® data collected randomly to the north 

 and east of WLIS indicated that historic dredged material was widespread throughout these 

 regions (EUer and Williams 1996). Therefore, all of the regions surrounding WLIS, except 

 the southeast, have been investigated prior to this report and historic dredged material has 

 been detected in every direction. 



To replace 2000W, we investigated the southeast region and identified a potential 

 reference area, SE-REF. We characterized the sediments using multiple survey 

 techniques, including: side-scan sonar, REMOTS® sediment-profile photography, and 

 sediment grab sampling with geochemical and grain size analyses. 



Monitoring Cruise at the WLIS Disposal Site, September 1997 and March 1998 



