Tissue samples were screened for the presence of several 

 different PCB formulations. These included Aroclors 1016, 1221, 1232, 

 1242, 1248, 1254 and 1260. Aroclor 1254 is the most prevalent mixture 

 in the marine environment of the Northeast region. 



Because each formulation contains different amounts of 

 chlorine, the response factors can vary between mixtures. The 

 detection limits for Aroclors 1016, 1242 and 1260 were the same as 

 that achieved for 1254. The detection limits were higher for the 

 other mixtures by factors of 4.0, 2.0 and 1.6 for Aroclors 1221, 1232 

 and 1248, respectively. In order to report a total PCB concentration 

 one would have to add the concentrations of all the different 

 mixtures . 



The PCB analyses were quality assured by measuring the 

 recovery of a surrogate compound (dibutylchlorendate) in each sample. 

 The recovery of this compound was 69% ±16 for the Central Long Island 

 Sound disposal site samples. 



3 . RESULTS 



3.1 Bathymetric Surveys at the CLIS Disposal Mounds 



The disposal mounds were evident as rapid changes in 

 topography (Figure 3-1) . Comparison with the results of the identical 

 survey in 1985 (Figure 3-2) revealed the only significant addition to 

 be the accumulation of new dredged material at the buoy (designated 

 as the CLIS-86 mound) . Modifications in the analysis software enabled 

 the production of higher resolution contour plots for the 1986 

 surveys . 



The minimum depth at the peak of the CLIS-86 mound was 16.6 

 meters; this mound apex was located approximately 60 meters east of 

 the disposal buoy location (Figure 3-3) . A detailed comparison of 

 this area was made with the survey conducted in August 1985 to 

 determine where depth differences occurred (Figure 3-4) and to 

 estimate the volume of material deposited since that time. This 

 volume difference calculation resulted in an estimate of approximately 

 79,200 m 3 of dredged material deposited during the 1985-86 disposal 

 season. Tabulation of scow logs indicated that approximately 164,045 

 m 3 of dredged material was deposited at CLIS-86 during the period 11 

 October 1985 to 5 May 1986. 



The standard error of the depth difference volume 

 calculation for the 650 x 700 meter survey area at CLIS-86 was 

 determined to be 4,246 m 3 , resulting in 95% confidence limits of 

 74,954 to 83,446 m 3 of dredged material detected on the bottom by 

 precision bathymetry. A detailed description of the calculations 

 required to determine this error and the 95% confidence limits around 



