1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 3: ANALYSIS
• Sediment results for nonpolar organic chemicals were normalized for total organic
carbon (TOC) for use in some of the evaluations conducted as part of the exposure
characterization. The normalized value was calculated by dividing the chemical
concentration by the fraction TOC (e.g., 2 percent TOC is 0.02 as a fraction) for each
sample. These results are included with the other bioassay data transformations on
the CD for Appendix D.
Chemical data meeting the data evaluation requirements were retained for further evaluation
in the ERA. The chemicals detected in each medium are presented in Table 3-1. The analytical
data for soil and sediment were also combined as a single exposure medium because both
media will become sediment under the post-restoration habitat types for the Lowlands.
Chemicals were also combined into “totals” for specific groupings. The totals were calculated
from the validated data, using detected values only. Non-detect results were not included in
the total. The chemical groupings and chemicals included in each are listed below:
• Low MW PAHs — anthracene, acenaphthylene, acenaphthene, phenanthrene, fluorene,
naphthalene
• High MW PAHs — benzo(a) anthracene, benzo(a) pyrene, benzo(e) pyrene, benzo(b)
fluoranthene, benzo(k) fluoranthene, benzo(g, h, i) perylene, chrysene, dibenz(a, h)
anthracene, fluoranthene, indeno (1,2,3-cd) pyrene, pyrene
• Total PAHs — low MW PAHs and high MW PAHs
• Total DDT — 4,4’-DDD; 4,4’-DDE; 4,4’-DDT
• Total PCBs — Aroclor 1242, Arochlor 1254, Aroclor 1260
• Total phenols — pentachlorophenol
• Total phthalate esters —bis(2-ethyhexyl)pthalate, butyl benzyl phthalate,
diethylphthalate, dimethylphtalate, di-n-butyl phthalate, di-n-octylphthalate
The data were then summarized by area and are presented in Table 3-2 for sediment/soil,
Table 3-3 for surface water, Table 3-4 for terrestrial plant tissue, Table 3-5 for terrestrial
invertebrate tissue, Table 3-6 for stilt eggs, Table 3-7 for small mammals, Table 3-8 for aquatic
invertebrates, and Table 3-9 for fish. The analyses of tissue data were conducted by taxonomic
group and are presented on the accompanying CD. The summary statistics were completed for
tissue groups (e.g. all terrestrial plants) because they would be used as a group in estimating
exposures. The summaries include number of detects; number of samples; minimum and
maximum reported concentrations; mean, median and 95th percent UCL of the mean; and
the 90th percentile. The raw data (including grain size) are presented in Appendix D.
A brief overview of the data is presented below for each area.
Bolsa Bay
Several chemical groups including metals, pesticides, PAHs, and semi-volatiles were
detected at Bolsa Bay. Metals were found with a high frequency of detection in
sediment/soil, and fish tissue. In fish tissue, 7 of 11 chemicals had a detection frequency of
100 percent. Of the 15 detected metals in sediment/soil, 7 had a detect frequency of
100 percent. All detected metals in surface water had a sample size of two.
SAC/143368(003.DOC) 3-9 ERA REPORT
7/31/02