individual disposal mounds (25 m lane spacing) were conducted to 

 detect more detailed changes in bottom topography. The results of 

 the bathymetric surveys conducted in October at STNH-N, STNH-S , 

 MQR, CS-1, and CS-2 (Figures 3-2 to 3-6) were compared with those 

 conducted in August to calculate any changes in the volume of 

 dredged material present (Table 3-1) . The volume of dredged 

 material at the Field Verification Program (FVP) disposal mound 

 comparing the August survey with the October survey is also 

 included (results from investigations at the FVP mound are 

 discussed separately in DAMOS Contribution #52) . The CS-1 mound 

 was the only one which experienced a detectable loss of material 

 (15,390 m^ ± 3,660; insignificant given the total area of the 

 survey) . Because no significant changes in depth at the individual 

 mounds was evident, only the October contour plots are presented 

 in this report. 



The results of the August bathymetric survey at the CLIS- 

 SE location (Figure 3-7) showed a relatively flat bottom topography 

 gently sloping to the south with depths from 2 0.4 to 21.4 meters. 



3.2 Side Scan Surveys 



The results of the side scan survey at CS-1 and CS-2 

 (Figure 3-8) showed areas of high acoustic reflectance indicating 

 the mounds of dredged material as well as some isolated patches in 

 the surrounding area that could have been dredged material. The 

 demarcation line in the figure indicates where natural bottom 

 occurred to the west beyond the boundary of the disposal site; the 

 region of intermediate reflectance in the eastern portion of the 

 survey most likely reflects the general area affected by disposal 

 operations. 



The results of the side scan survey conducted at the 

 southeast quadrant of CLIS (Figure 3-9) showed areas of high 

 acoustic reflectance located on the western portion of the survey 

 area representing dredged material disposed at the Stamford-New 

 Haven South (STNH-S) disposal mound. The demarcation line 

 indicates where intermediate reflectance occurred along the western 

 edge of the survey area due to dredged material from previous 

 activity at the SP buoy, NH-74, and STNH-N disposal mounds. The 

 area chosen as CLIS-SE (to the east of the demarcation line) was 

 clear of dredged material and sufficiently far from potential 

 interference from the existing dredged material at STNH-S and FVP 

 to the north. A representative portion of the side scan record 

 from the survey at CLIS-SE (Figure 3 -10a) showed the relatively 

 "clean" (i.e., lack of any reflective targets) gently sloping 

 bottom. A section of the side scan record from the western portion 

 of the survey area near STNH-S (Figure 3-lOb) illustrates the high 

 reflectivity normally attributed to dredged material; these areas 

 of high reflectance did not occur in the CLIS-SE area. 



