station in the present study (0.58-1.1 ppm) were similar to the 1 

 to 3 ppm concentrations reported by Munns et al. for the reference 

 station. Cd concentrations on dredged material in the present 

 study (0.85-1.2 ppm) were not significantly increased over 

 reference levels. This is similar to what was reported for Cd by 

 Munns et al. 



The PCB concentrations reported here for Nephtys were 

 below the analytical detection limits for all samples (Table 3-31) . 

 These detection limits ranged from 270-770 ppb. The detection 

 limits were generally higher than the concentrations previously 

 measured by Munns et al. in Nephtys from the reference station 

 (200-400 ppb) . 



The measured wet weight concentrations for Hg (Table 3- 

 30) and PCBs (Table 3-31) were well below the FDA Alert Levels. 

 These were the only compounds guantif ied for which Alert levels are 

 presently being applied. The FDA Alert Levels are 0.2 ppm for Hg 

 and 2 ppm for PCBs. 



5 . CONCLUSIONS 



The only significant addition to the bathymetric features 

 at CLIS was the development of the new CLIS-86 disposal mound, 

 which had a maximum thickness of 2 meters and a radius of about 250 

 meters as detected with acoustic methods. The REMOTS® results 

 showed that recently-deposited dredged material covered an area 

 with a north-south radius of about 350 to 400 meters and an east- 

 west radius in excess of 600 meters. An estimated 131,920 m 3 of 

 disposed material was detected on the bottom using precision 

 bathymetry and REMOTS® photography, compared to a scow log volume 

 estimate of 164,045 m 3 . No evidence of significant changes in 

 topography at other mounds was detected. 



The bathymetric and side scan surveys conducted at GHOST- 

 1 and GHOST-2 outside the CLIS boundaries did not detect large 

 enough areas of high reflectance or distinct changes in depth to 

 account for the approximately 50,000 yd of dredged material 

 allegedly deposited in each area. Likewise, there was no 

 conclusive evidence of dredged material in the REMOTS® photographs 

 obtained in these two areas. 



Based on REMOTS® parameters, the new CLIS reference 

 station had higher mean OSI values than any of the disposal mounds 

 which were surveyed. This new area appears to represent a valid 

 reference station for future monitoring. Mean OSI values at the 

 STNH-N, CS-2, FVP, NOR, and NH-74 disposal mounds, as well as those 

 at Ghost Sites 1 and 2, were not significantly different from those 

 measured at the new CLIS reference station. The three disposal 

 mounds that consistently have exhibited relatively low mean OSI 

 values (STNH-S, NH-83 and MQR) are located along the southern 



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