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

exceeded state criteria and national guidelines at different locations, with the majority of the
LPAH compounds detected above these values in the West Harbor Island samples, and the
majority of the HPAH compounds found in the Elliott Bay and Duwamish River samples. There
were 6, 15, and 3 samples in which the concentration of at least one PAH compound exceeded
the ERM, SQS, or CSL values, respectively, representing areas equivalent to 0.4%, 0.7%, and
0.07% of the total survey area.
The concentrations of phenols were low in the central Puget Sound stations, with the exception
of 4-methylphenol, which was elevated above the SQS and CSL values in 22 samples scattered
throughout the study area (23% of the total area). The concentration of the compound 2,4-
dimethylphenol was elevated above SQS and CSL levels at station 188 in Elliott Bay (0.14% of
the study area), while the concentration of pentachloropl~enol was elevated above the SQS value
at station 205 in the Duwamish River (0.03% of the study area).
Phthalate ester concentrations, including bis(2-etl-1yll-1exyl)pl~tl1alate, butylbenzlphthalate, and din-butylphthalate,
were detected above state criteria levels only in the stations from Elliott Bay,
East Harbor Island, and the Duwamish River. There were a total of 7 samples with phthalate
ester concentrations exceeding SQS criteria (0.76 % of study area), and 1 sample exceeding the
CSL criteria (0.03% of the study area).
The concentrations of chlorinated pesticides for which national guidelines exist were found to be
below ERM levels for both 4,4'-DDE and total DDT. Total PCB congeners (>QL data)
exceeded the ERM value in 12 samples, located in Elliott Bay, East and West Harbor Island, and
the Duwamish River, and covered 0.55% of the total study area. In contrast, total PCB Aroclor
concentrations exceeded the SQS value in 36 samples and the CSL in one sample, but all of these
concentrations were measured at or below the method quantitation limits reported by MEL, and
these limits exceeded the guideline values.
Five of the nine compounds in the remaining suite of miscellaneous compounds were not found
above guideline levels in any samples, or were measured at or below method quantitation limits
that exceeded the guideline values. The compound 1,4-dichlorobenzene was measured above its
SQS value at station 200 (0.02% of the study area), collected east of Harbor Island. Benzyl
alcohol was measured above its SQS value at stations collected near Bainbridge Island, in Dyes
Inlet, and Elliott Bay (1.7% of the study area), and above its CSL concentration at the Bainbridge
Island station (0.5% of the study area). Dibenzofuran was measured above its SQS value at one
station in Elliott Bay and three stations collected west of Harbor Island (0.13% of the study area),
and above its CSL value at one of the West Harbor Island stations (0.04% of the study area).
High concentrations of benzoic acid were found almost ubiquitously throughout the central Puget
Sound study area, exceeding the SQS and CSL concentrations in 89 samples. These samples
represented about 8 1 % of the total study area.
When all the chemical concentrations for which ERM values were derived (excluding nickel)
were compared to their respective guidelines, 2 1 samples had at least one reliable chemical
concentration greater than an ERM value. These 2 1 samples represented about 1.6% of the total
survey area. In contrast, there were 95 and 94 samples in which at least one SQS or CSL value
(respectively) was exceeded, representing about 99% of the survey area. Excluding the data for
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