62 



sediment data from three hundred sites since 1984. Several stations in western Long Island 

 Sound that had been sampled over the period of 1984-1989 (NOAA 1991) were compared to 

 the WLIS proposed reference stations. All of these areas were coastal (north shore of Long 

 Island or south shore of Connecticut) except for the western Long Island station (NS&T code 

 WLI) which was located approximately 5 km west of WLIS. 



In comparing the WLIS results with NS&T data, several qualifications should be 

 made. The analytical methods used vary somewhat between the two datasets because NS&T 

 methods were developed for very low detection limits. For example, although pesticides 

 were not detected in most of the WLIS replicates, the detection limits were higher than those 

 of the NS&T data, so the two datasets could not be compared. PCBs were analyzed by 

 NS&T methods as individual isomers, and so were not directly comparable with the total 

 PCB measurement obtained by the NED laboratory. All NS&T data were normalized to the 

 fine-grained fraction since the correlation between the percentage of silt and clay and trace 

 chemical constituents was higher than between Al or TOC (NOAA 1991). Therefore, the 

 WLIS data were also normalized to the fine-grained fraction for comparison purposes. 



PAHs measured at SOUTH and EAST were all within the range of the values 

 measured at the NS&T western Long Island Sound stations (Table 4-1). Of the NS&T sites, 

 two had the highest concentrations of all PAH compounds: the Throgs Neck station (the 

 farthest west station in Long Island Sound) and the Sheffield Island station, located northwest 

 of WLIS. Hempstead and Huntington Harbors on the north shore of Long Island, and the 

 Mamaroneck station on the southern coast of Connecticut had the lowest PAH 

 concentrations. 



The NS&T WLI station fell between the sets of maximum and minimum PAH 

 concentrations measured in western Long Island Sound. The EAST and SOUTH values were 

 comparable to the PAH concentrations measured at the WLI station. High molecular weight 

 PAH concentrations from WLI were almost identical to concentrations measured at SOUTH,, 

 and were very similar to those at EAST (Table 4-1). Low molecular weight PAH 

 concentrations measured at SOUTH and EAST were slightly lower than those measured at 

 WLI, and were actually more similar to those measured at Hempstead Harbor (Table 4-1). 



Metals results from SOUTH and EAST were, in general, similar to or lower than 

 metals concentrations measured at the NS&T WLI site (Table 4-2). However, of the trace 

 metals, As and Zn were higher than most of the NS&T stations. Zinc concentrations at both 

 EAST and SOUTH, and As at EAST, were higher than all of the other NS&T stations. 

 Categories of trace metal concentrations suggested by the New England River Basins 

 Commission (NERBC) were included in Table 4-2 as a guide to metals concentrations. The 

 metals concentrations measured at SOUTH and EAST all fell within the low to moderately 

 contaminated categories. Arsenic and Zn concentrations were elevated relative to other sites 



Monitoring Cruise at the Western Long Island Sound Disposal Site, July 1992 



