Also, the contaminant concentrations of the Top and Bottom 

 sections of the cores were compared. The Kruskal-Wallis test was 

 used for comparing concentrations to detect significant 

 differences at the p < 0.05 level. 



Results of the statistical analyses showed that in the 

 cores from the Reference station, the concentration of chromium 

 was significantly higher (p<0.05) in the Top sections whereas 

 those of iron were significantly higher in the Bottom sections. 

 In the WLIS-A station cores, concentrations of lead, nickel, 

 copper, and oil and grease were significantly higher in the Top 

 sections compared to the Bottom sections. The concentrations of 

 these same four elements were significantly elevated in Top 

 sections of the WLIS-A cores compared to those of the Reference 

 station cores. 



The physical characteristics were determined for the 

 sediment collected for the benthic community analysis (Table 3- 

 2) . The sediment from all five samples obtained at the "A" mound 

 center was described as dark gray silty sand with some gravel 

 and/or shell fragments. The sediment from the Reference station 

 was much finer material dominated by dark, olive gray organic 

 clay with shell fragments. 



3.4 Benthic Community Analysis 



The sieve residues from the Reference station samples 

 consisted of 500-1,200 cm 3 of shells and shell particles. Intact 

 shells of bay scallop ( Aequipecten irradians ) , soft shell clam 

 ( My a arenaria ) , gem clam ( Gemma gemma ) , juvenile surf clam 

 ( Spisula solidissima ) , and mud snail dlyanassa obsoleta) all 

 suggest an origin in shallow sandy bottom. Coot clam ( Mulinia 

 lateralis ) shells were also present, but are less indicative of 

 origin. The samples contained a small amount (approximately 20 

 cm 3 ) of fine organic debris. 



Samples collected at the center of "A" mound contained 

 3000-4000 cm 3 of sand and pebbles and about 100 cm 3 of coarse 

 plant debris. Smooth white quartz pebbles were a conspicuous 

 constituent. Bits of coal, boat paint, and rust could be seen 

 under magnification. Table 3-3 presents the visual descriptions 

 of the sediment grabs collected at both WLIS-A and the Reference 

 station for benthic community analysis. 



Species counts are given in Table 3-4. A summary of 

 the number of species and individuals in major taxa at each 

 station is given in Table 3-5. The number of species present at 

 the two stations follows a pattern found at other disposal sites. 

 Species richness is lower at the Reference station than at the 

 WLIS-A station. At both stations, polychaetes were the most 

 abundant taxon followed by molluscs and crustaceans. 



