Sediment Quality in Puget Sound Year 2 - Center for Coastal ...

Spatial Patterns in Chemical Contamination
The spatial (geographic) patterns in chemical contamination were determined by identifying on
maps the locations of sampling stations in which numerical sediment quality guidelines (ERM,
SQS, and CSL values) were exceeded (Figures 19-23). Tables 12 and 13 provide detail regarding
the specific chemical compo.unds that exceeded these guideline values at each station. The
number of compounds exceeding the ERL values and the mean ERM quotient calculated for each
station, are also provided in Tables 12 and 13, and discussed below.
Spatial patterns in chemical contamination in strata 1,2,4, and 5 near Port Townsend, southern
Admiralty Inlet, and in Possession Sound, are displayed in Figure 19 and summarized in Table
12. None of the ERM values were exceeded in these 12 sediment samples. The ERM quotients
for all samples except those from stations 107 and 1 18 were less than 0.1, suggesting that very
little contamination occurred in this area. For samples 107 and 1 18, three chemicals exceeded
the ERL values, and mean ERM quotients were 0.24 and 0.13, respectively, suggesting a slight
degree of contamination. One chemical, 4-methylphenol, exceeded state SQS and CSL values at
six stations within strata 1,2,4, and 5. Five of these samples were collected in Port Townsend
(stations 106-1 09, 1 1 1) and the other near Mukilteo (station 1 18) in Possession Sound.
None of the chemical concentrations in samples from strata 6-8 in the central basin and Port
Madison, and in strata 13-1 5 (Liberty BayIKeyportlBainbridge Island) exceeded ERM values
(Figure 20, Table 12). Mean ERM quotients in these samples were low (0.04 to 0.26). Samples
with chemical concentrations exceeding ERL values included those from stations 128 (16
compounds); 142-144, 146 (4 each); 148 (3); 129 (2); and 122, 123(1 each). As in strata 1,2,4,
and 5, the SQS and CSL values for 4-methylphenol were exceeded in samples 113, 122, 123, and
148, again suggesting these samples were only slightly contaminated.
In the samples collected in the southern reaches of the central basin and Eagle Harbor, all
chemical concentrations were below the ERM values (Figure 21, Table 12). However, in
samples 130 and 13 1 from Eagle Harbor, mean ERM quotients were 0.33 and 0.36 and 17 and 19
ERLs were exceeded, respectively, in these samples, suggesting a slight degree of contamination.
The CSL concentration for 4-methylphenol was again exceeded in the sample from station 140.
No other samples from strata 9-12 had chemical concentrations exceeding Washington State
sediment standards.
Figure 22 and Table 12 summarize spatial patterns for chemical contamination in the sediments
collected near Bainbridge Island, Port Orchard, and Bremerton (strata 16-22). Contaminant
levels in the samples collected from strata 16 through 18,21, and station 169 (Dyes Inlet) were
all measured below ERM values, with low mean ERM quotients (0.04 - 0.19). The ERL values
were exceeded at stations 15 1 and 153 (SW Bainbridge Island), and 168 (Port Washington
Narrows), while the CSL values for benzyl alcohol was exceeded only at station 15 1.
Samples from stations 170 and 17 1 in Dyes Inlet also displayed no contaminant levels above
ERM values, with the exception of nickel at station 170. Long et al. (1995), however, suggested
that there was a limited degree of reliability in the ERM value for nickel, and that nickel does not
play a major role in causing toxicity. The mean ERM quotient values were higher, 0.25 and 0.26,
Page 32