11 



3.2 Trace Metal Results 



The results from the three replicates were averaged for each station (Table 3-1). 

 Almost all of the metals concentrations were within the "low" category of contaminated 

 sediments as classified by the New England River Basin Commission (Oceanic Society 1982). 

 Exceptions, which fell in the moderately contaminated category, include four (out of twenty- 

 eight) Cr results, five Pb results, and one Zn result. 



Cadmium concentrations were below detection ( < 2 ppm) in all samples except for 

 one replicate from Station 8-7 (4 ppm). Average Cr concentrations ranged from 38 ppm 

 (16-9) to 123 ppm (10-9). Nickel concentrations were below detection (< 14 to < 16 ppm) 

 at several stations, and reached a maximum of 35 ppm at Station 8-3 (Table 3-1). Copper 

 concentrations ranged from 19 ppm (8-9) to 78 ppm (Station 12-3). The lowest Zn 

 concentration was also measured at Station 8-9 (66 ppm), and the highest, 221 ppm, was 

 again found at Station 12-3. Mercury was below detection limits (<0.05 ppm) in all 

 replicates at Station 8-7, and in two out of three replicates at Stations 8-3 and 8-5. The 

 highest Hg concentration was measured at Station 12-3 (0.47 ppm), followed closely by 

 Station 14-9 (0.45 ppm), which is the station located by the "MDA" buoy (Figure 2-1). 

 Finally, Pb concentrations ranged from 29 ppm at Stations 16-7 and 16-9 to 155 ppm at 

 Station 9-6 (Table 3-1). 



3.3 TOC, Pesticides, and PCB Results 



All of the samples collected in the June 1989 survey were analyzed for TOC. 

 Average TOC values ranged from 0.44% at Station 10-7 to 2.2% at Station 18-17 (Table 



3-2). 



Composited samples, and two replicates of 18-17, were analyzed for pesticides and 

 PCBs. Most of the analyzed pesticides were below detection limits in all of the samples. 

 The most commonly detected pesticide was 4,4'-DDE (DDE), which was detected in 

 seventeen of the thirty samples at concentrations ranging from 0.65 (Station 10-7) to 

 10.5 ppb (Station 18-17; Table 3-2). The only other pesticides detected, including endrin, 

 dieldrin, and 4,4'-DDD, were all at Station 10-7 (Table 3-2). 



PCBs were not detected ( < 20 ppb) in any sample except in the composite sample 

 from Station 16-9, at barely above the detection limit (20 ppb; Table 3-2). 



3.4 BNA Results 



Composited samples were analyzed for BNA compounds including PAHs. Many of 

 the PAH sample results were qualified ("J") as estimated when they were less than the MDL 

 but were able to be quantified from the chromatographic peaks (above the practical 



Chemical Analyses of Sediment Sampling at the Massachusetts Bay Disposal Site, June 1989 



