1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 1: INTRODUCTION
1.5 Organization of the ERA Report
This ERA is organized as follows:
• Section 2.0 – Problem Formulation. Provides information, largely taken from the
Scoping Assessment (CH2M HILL, 1998b) and updated in the Ecological Effects
Characterization (CH2M HILL, 1999), that was used to develop the exposure and
ecological effects characterizations in the Analysis section. This section presents
preliminary site background information; describes the different habitats found onsite;
lists potential ecological receptors for the site; summarizes chemicals of potential
ecological concern (COPECs), screening reference toxicity values (RTVs) for the
COPECs, and results of screening for potential risks that was conducted in the Scoping
Assessment; lists assessment endpoints, risk hypotheses, and measures that will be used
to assess ecological effects; and presents the ecological conceptual site model for
potential ecological exposures for representative ecological receptors.
• Section 3.0 – Analysis. Presents the Exposure Characterization and Ecological Effects
Characterization, which analyze and evaluate results of the two phases of field sampling
(the ERA Sampling and Analyses and the Focused Sampling and Analysis), as well as
relevant data from Tetra Tech (1996). This section summarizes the field sampling and
analysis; presents the data evaluation for chemicals detected in the Lowlands; presents an
updated evaluation of background concentrations of inorganics detected onsite;
summarizes potential sources of chemical stressors and their spatial distribution across the
site; summarizes chemical-specific exposure point concentrations of COPECs to which
plants and animals may be exposed; presents estimated daily doses for terrestrial and
semi-aquatic birds and terrestrial mammals; reports the results of bioassays performed on
sediment, pore water, and surface water from the site; discusses dose-response
evaluations conducted using univariate regression analyses; and summarizes the exposure
and effects information into an exposure profile and stressor-response profile.
• Section 4.0 – Risk Characterization. Presents results of quantitative and qualitative risk
evaluations to provide a weight-of-evidence for characterizing the presence or absence
of risk to representative receptors in each evaluation area of the Lowlands. This section
also includes a discussion of uncertainties and limitations associated with the
information and methodologies used in this ERA.
• Section 5.0 – Conclusions and Recommendations. Provides a summary of conclusions
of the ERA and recommendations for the site as a whole, as well as specific evaluation
areas within the Lowlands.
• Section 6.0 – References. Provides a list of information sources used in this report.
• Tables, Figures, and Appendices. Contain information used to support ERA
ERA REPORT 1-8 SAC/143368(001.DOC)
7/31/02