collected at various locations within the site showed little, if 
any, statistically significant differences in contaminant 
concentrations. There was little supporting evidence at the 
disposal site to suspect either that a thin layer of contaminants 
was concentrated at the sediment surface due to resuspension and 
transport or, conversely, that surface sediment was cleaner than 
deeper layers due to desorption of contaminants, selective 
winnowing, or deposition of cleaner material. 
An examination of temporal trends in trace metal 
concentrations from the Reference station and disposal mounds NL-I 
and NL-II over the past 4 years showed trace metal levels remained 
relatively stable at these stations. Similar results were found 
for the levels of organic compounds from these locations. Even 
though trace metal levels appeared temporally stable at these three 
locations, the levels of mercury, lead, zinc, arsenic, chromium, 
and copper were significantly elevated at several of the mounds 
compared with the Reference station; the levels of copper were 
consistently elevated at all sites tested. These levels were also 
higher than levels reported as background concentrations in eastern 
Long Island Sound; however, all concentrations fell within NERBC 
Class I (low) or lower Class II (moderate) catagories. This is 
consistent with concentrations detected in the disposed material 
during pre-dredging testing. Nickel and cadmium levels were below 
analytical detection limits at each site. The NL-85, NL-I, and NL- 
RELIC stations showed somewhat elevated levels of total organic 
carbon; PCB concentrations of the NL-85 and NL-I sediments were at 
measurable, but low concentrations. 
There were no Significant differences in the 
concentrations of any of the eight metals tested in Pitar between 
the Reference and disposal mound stations. This information and 
comparisons of the trace metal data to literature values from 
relatively clean sites suggests that trace metals were not 
bioaccumulating in the bivalve Pitar morrhuana at the New London 
Disposal Site. The same was also true for PCBs. All of the PCB 
concentrations were below the analytical detection limits and well 
below FDA Alert Levels. These initial baseline data showed that 
there was minimal impact to resident suspension-feeding bivalves 
as a result of dredged material disposal at the New London Disposal 
Site. 
38 
