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

espectively, and each station had 10 compounds exceeding ERL values. Again, the SQS value
for benzyl alcohol was exceeded at both stations, while both SQS and CSL values for mercury
were exceeded at station 17 1. With the exception of station 16 1, all six samples collected from
Sinclair Inlet exceeded the ERM value for mercury. Mean ERM quotients at these stations were
high, ranging from 0.27 to 0.55, and ERL values were exceeded for 7 to 11 compounds in each
sample. All six samples exceeded the SQS and CSL values for mercury.
Spatial patterns in chemical contamination in the sediments collected in Elliott Bay and the
Duwamish River are summarized in Figure 23 and Table 13. The degree of chemical
contamination increased steadily and considerably from the outer to the inner reaches of the bay.
Sediment samples collected from the outer bay (strata 23,24, and 28) had no chemical
concentrations exceeding ERM values, mean ERM quotients ranging between 0.06 and 0.45, and
ERL values were exceeded for 0 to 16 compounds. Sediments from stations 174, 176, and 190
did, however, have concentrations of butylbenzylphthalate (stations 174, 176), di-n-
butylphthalate (station 190), and mercury, benzo(g,h,i)perylene, and phenanthrene (station 176)
above the SQS levels.
Samples collected along the Seattle shoreline and inner bay (strata 25-27,29) and in the lower
Duwamish River (strata 30-32) were the most contaminated among the 100 tested in central
Puget Sound. In the samples from these seven strata, many chemical compounds (up to 25 per
station) had concentrations exceeding ERL levels, and mean ERM quotients ranged from 0.37 to
3.93. Notable among these 25 samples were those from 1 1 stations (i.e., 18 1, 1 82, 184, 188, 194,
198, 114,200,201,202, and 205) in which chemical concentrations exceeded 20 to 25 ERL
values, and mean ERM quotients exceeded 1.0 (1.05-3.93).
Within these seven strata, a variety of compounds (up to 10 per station) had concentrations
exceeding ERM, SQS, and CSL values. Some unique patterns were discerned with regard to the
chemical compounds that exceeded national guidelines and state criteria. Mercury values
exceeded only the state criteria, and only at some of the shoreline and mid-Elliott Bay stations,
while other metals were detected above state criteria (arsenic) and national guidelines (arsenic
and zinc) near West Harbor Island only (station 197). The majority of the samples exceeding
HPAH national guidelines and state criteria were collected from shoreline and mid-Elliott Bay
stations. With one exception (station 198), total LPAH values exceeded only national guidelines.
However, one LPAH compound (phenanthrene) exceeded both state criteria and national
guidelines at some shoreline and mid-Elliott Bay stations, while four other LPAH compounds (2-
methylnaphthalene, acenaphthene, fluorene, and naphthalene) exceeded both sets of values at the
three West Harbor Island stations (stratum 30). Total PCBs exceeded ERM values only. They
did not exceed SQS and CSL values. Phenol concentrations (primarily 4-methylphenol),
however, exceeded only state criteria, and were found primarily in the Harbor Island and
Duwamish River samples. The phthalate esters bis(2-ethylhexyl)p11thalate and
butylbenzylphthalate were found only in the East Harbor Island and Duwamish River samples.
Four other compounds which exceeded state criteria only included dibenzofuran (station 183 and
198), benzyl alcohol (station 188), 1,4-dichlorobenzene (station 200), and pentachlorophenol
(station 205).
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