31.75 m, while the minimum depths of mounds "A" and "C" remained 

 unchanged. In the present survey, the minimum depths at mounds "A", 

 "B" , and "C" were 29.50 m, 29.75 m, and 27.78 m, respectively. 

 Bathymetric charts of the area surrounding mound "B" in August 1986 

 (Figure 3-2), November 1987 (Figure 3-3), and July 1988 (Figure 3-4) 

 illustrate the changes in depth which were due to the addition of 

 dredged material within a radius of approximately 100 m around the 

 buoy. 



Depth difference calculations indicated that between the 

 November 1987 and July 1988 bathymetric surveys, a total of 23,370 

 m 3 of dredged material was added to the area within about 200 m of 

 the disposal buoy. Tabulation of scow logs for the same period 

 indicated that approximately 52,842 m 3 (69,074 yds 3 ) of dredged 

 material were deposited at or near the buoy. 



3.2 REMOTS® Sediment-Profile Photography 



Recently-deposited (i.e., since November 1987) dredged 

 material exceeding the depth of prism penetration occurred at 

 stations 3-C and 5-C in the immediate vicinity of the WLIS "B" mound 

 (Figure 3-5) . This material had a "mottled" appearance caused by 

 alternating high and low reflectance streaks (Figure 3-6) , and it 

 also exhibited a significant sand component in many photos (Figure 

 3-7). 



As in the November 1987 survey, relict or "weathered" 

 dredged material was evident at stations on or near the "A" and "C" 

 mounds. For example, station 3-G at the "C" mound continued to 

 exhibit poorly-sorted relict material characterized by discontinuous 

 sand layers at depth (Figure 3-8) . Likewise, a distinct relict 

 dredged material layer about 7 cm deep remained visible at station 

 5-E near the "A" mound. Some stations located away from the three 

 disposal mounds (-1-Y, -1-Z, -1-A, -1-K, -1-M, -1-1, 1-K, 1-M, and 

 7-G) also exhibited indistinct, low-reflectance horizons at depth 

 suggestive of relict dredged material layers (Figure 3-9) . 



The majority of REMOTS® on-site and reference stations 

 consisted of silt-clay sediments (> 4 phi, Figure 3-10) . As in 

 1987, a cluster of stations in the immediate vicinity of both the 

 active ("B") and recent ("A" and "C") disposal mounds exhibited a 

 significant sand component and were mapped with a grain size major 

 mode of >4-3 phi (fine sand/silt/clay) . Likewise, sediments having 

 a >4-3 phi major mode continued to occur at stations near the 

 northwest corner of the sampling grid and at reference station 

 2000S. 



The freguency distribution of apparent RPD depths for the 

 disposal site stations had a major mode at the 3.0 cm class 

 interval, while the corresponding freguency distribution for the 

 reference stations had major modes at the 2 and 4 cm class intervals 



