main sampling grid, and general background information. 

 Positioning of the reference areas was constrained by the need to 

 find areas of comparable water depth and bottom type, while still 

 maintaining a sufficient distance from the disposal site 

 boundaries. Adequate locations for reference stations were 

 difficult to establish, because most of the region surrounding the 

 disposal site was either too shallow or too hard-bottomed. 



Three replicates were analyzed for the majority of 

 REMOTS® stations within the disposal site and at REF-3 (Figure 2- 

 2) . Some stations, such as those at REF-1, yielded few pictures 

 for analysis. This was due principally to hard substratum and 

 subsequent lack of camera penetration. The rocky nature of the 

 bottom at REF-1 illustrates the difficulty of selecting adequate 

 reference stations in the immediate vicinity of the Saco Bay 

 Disposal Site (Figure 2-4) . Reference areas REF-2 and REF-3 

 provided the majority of photographs used for analysis and 

 interpretation . 



3 . RESULTS 



3 . 1 Bathymetry 



Acoustic detection of dredged materials at the Saco Bay 

 Disposal Site was hampered by the relatively low volume of material 

 disposed, its apparently wide distribution over the site, and the 

 lack of a pre-disposal survey. Although the bathymetric survey did 

 not detect a single, distinct mound, there were several features 

 that probably represented the results of dredged material disposal. 

 A potential disposal feature was present in the region between the 

 32.0 m and 32.5 m contours, just west of the survey center and 

 tending toward the southwest (Figure 3-1) . An enlargement of this 

 region revealed three small peaks (A, B, C) elevated approximately 

 0.5 m above the surrounding topography, and between 25 to 60 m in 

 diameter (Figure 3-2) . The area encompassing peaks A, B, and C was 

 approximately 11,940 m 2 and roughly 150 m in diameter. Water 

 depths across the site deepened progressively towards the east and 

 away from shore (Figure 3-1) . The shallow feature at the extreme 

 northeast corner of the survey was part of the natural bottom 

 topography and unrelated to disposal activities. 



3.2 REMOTS® Sediment-Profile Photographs 



The REMOTS® survey identified dredged material in the 

 central and southern portions of the survey (Figure 3-3) . Almost 

 all of this material extended beyond the penetration depth of the 

 camera and consisted of fine sands (3-2 phi) over the top of very 

 fine sands (4-3 phi) (Figure 3-4) . In contrast, ambient sediments 

 were unlayered and composed of very fine sands (4-3 phi) to silt 

 (>4 phi) (Figure 3-5) . Undisturbed sediments were present north of 



