84 



layer. RPD depths, successional stage status, and OSI values all indicate that this trend 

 will continue well into the future. 



Comprehensive chemical analysis of the new surface sediment layer over the MQR 

 mound indicates the area surrounding this bottom feature should reflect conditions found at 

 the CLIS reference areas. Comparison of metals results at the MQR mound show that nine 

 of the ten average metals concentrations at the mound were lower than or equal to the 

 respective concentrations at the three reference areas. Average copper concentrations over 

 the MQR mound were slightly elevated with a concentration of 80 ppm, versus the average 

 reference value of 57 ppm. The Cu concentration of 80 ppm at the MQR mound is still 

 well below the "low" category of the NERBC, which is <200 ppm (Appendix A, Table 

 10). As a whole, the average metals concentrations, as well as the individual station 

 metals concentrations are all classified as "low" in accordance to the NERBC except for 

 the following stations which are classified as "moderate": Cd at MQR-3 (4.2 ppm), Cr at 

 MQR-7 (110 ppm), and Hg at MQR-1 (0.58 ppm), MQR-6 (0.65 ppm), MQR-7 

 (0.98 ppm), and MQR-10 (0.63 ppm). 



Average total PAH values were slightly elevated on the MQR mound in comparison 

 to the reference areas, as were the average LMW and HMW PAH compounds. This result 

 can be attributed to the fact that the cap material of the MQR mound was attained from an 

 area affected by anthropogenic activities within New Haven Harbor, which typically show 

 increased levels of PAHs. The reference areas are representative of ambient sediments of 

 Long Island Sound and therefore anthropogenic sources and inputs of PAHs are less in 

 comparison to urbanized areas. The individual station and average fine-grained normalized 

 PAH data values pertinent to the MQR mound are below the PAH fine-grained normalized 

 values of the NS&T sites located within Long Island Sound. As with the metals 

 concentrations, the raw and normalized PAH values do not indicate an obvious correlation 

 between PAH concentrations between the two sediment types of the MQR mound. 



Monitoring Cruise at the Central Long Island Sound Disposal Site, July 1994 



