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Harry M. Ohlendorf 33 rd Annual SETAC Meeting November 15, 2012 . Ecological Risk Assessment for Decision-making in Restoration of the Bolsa Chica Lowlands, California. Acknowledgments.
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Harry M. Ohlendorf33rd Annual SETAC Meeting November 15, 2012 Ecological Risk Assessment for Decision-making in Restoration of the BolsaChica Lowlands, California
Acknowledgments • Interagency Steering/Technical Committees of representatives from multiple agencies: Corps of Engineers, USEPA, USFWS, NOAA, California Department of Fish and Game, California Resources Agency, California Regional Water Quality Control Board, State Coastal Conservancy, California State Lands Commission • Subcontractors: Kinnetic Laboratories, ToxScan • CH2M HILL staff: Marjorie Eisert, Trudy Pulley, Brad Sample, Steve Long, et al.
Overview Location: Orange County, CA Purpose: Restore portions of the wetland ecosystem of the BolsaChica lowlands as mitigation for development of port facilities in nearby Los Angeles County Scale: ~1,250 acres Setting: Included more than 430 active or abandoned oil wells, along with associated pipelines, roads, former tank farms, and other related facilities on the property; storm drainage enters from nearby urbanized areas Expected Result: Restore tidal influence from the Pacific Ocean to about half of this area to reinvigorate the wetland ecosystem
Project Goals • Remove oil production facilities and clean up associated contaminants • Protect and enhance marine habitat for coastal and estuarine fisheries resources • Increase and enhance habitat for migratory waterfowl, seabirds, and shorebirds • Provide habitat for endangered species including the light-footed clapper rail, Belding’s savannah sparrow, and California least tern • Incorporate passive and non-intrusive human activity, including public education, after construction
Project Approach • Restoration of the BolsaChica wetlands was directed by a federal/state interagency Steering Committee of representatives from the following agencies: • Corps • USEPA • USFWS • NOAA • California Department of Fish and Game (CDFG) • California Resources Agency • State Coastal Conservancy • California State Lands Commission (SLC)
Project Approach (cont’d) • USFWS, USEPA, NOAA, CDFG, CSLC, and the California Regional Water Quality Control Board provided members of their staff to form the BolsaChica Technical Committee. • CH2M HILL worked with the Technical Committee during 1997-2005 in evaluating ecological risks and developing an approach to cleanup and restoration based on post- restoration habitats.
Project Approach (cont’d) • ERA to determine if chemicals in soil, sediment, or water posed a risk for future use as a wildlife refuge, and if so, remediation goals for cleanup • In addition to sampling to complete the ERA, we took additional sediment samples for dredge material evaluation • Methods and results for the dredge material evaluation were similar to the random sampling strategy but samples were collected (one per acre) to the proposed dredge depths within the dredge channel footprint.
Ecological Risk Assessment (ERA) • Used a phased approach, as recommended by USEPA and California EPA • Three data collection or evaluation phases used to produce various documents • Data and observations from one phase used to determine whether further studies were necessary to meet the objectives of the ERA to ensure that “…only the necessary work [was] done and all of the necessary work [was] done”
Phase 1 - Site Screening • Review of site information identified over 230 chemicals of potential ecological concern (COPECs) for the site, including inorganics, petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), semivolatile organic compounds (SVOCs), volatile organic compounds (VOCs), organochlorine pesticides, PCBs, organochlorine herbicides, and organophosphorus insecticides.
Phase 2 - Site Characterization: ERA Sampling and Analysis • First sampling phase (“ERA Random Sampling”) to determine levels of constituents identified as COPECs and to conduct laboratory bioassays • Random sampling points within a stratified grid density of about one sample location per 4 acres; if “focused” sites (areas of known or suspected contamination) existed within a given grid, these were excluded from the ERA Random Sampling • Prepared an Ecological Effects Characterization Report
Phase 3 – Site Characterization: Focused Sampling and Analysis • Three main site categories were sampled: • Random Follow-up sites (discrete locations sampled during the ERA Random Sampling where the composite sample representing those locations had at least one analyte that exceeded screening levels • Previously Identified Sites with no supporting data • Partially Characterized Sites for which some existing data were available • Prepared Baseline ERA
Cleanup Plan • ERA identified chemicals that either: • Did not present a risk and did not need to be considered further; or • Presented risks to plants or animals that are expected to use the site after restoration and required further evaluation or remediation (total = 70 COECs) • BolsaChica Technical Committee: • Used weight-of-evidence approach to reduce the list of COECs and develop cleanup criteria that focused on 14 of the risk-driver COECs • Identified cleanup levels for material to be managed on-site and material to be hauled off-site
Cleanup Plan (cont’d) • Full Tidal area, delineation sampling was conducted on three categories of sites: • Single-point Site Sampling • Non-Linear Site (Polygon) Sampling • Linear Site Sampling • Delineation sampling began at sampling locations where results exceeded delineation concentrations and stepped out incrementally to delineate vertical and horizontal extent of contamination
Summary • Extensive sampling was conducted in sensitive habitats without unacceptable effects • ERA provided an effective approach for identifying site contamination and effects • ERA results were adequate to identify cleanup needs and disposition of contaminated soil/sediment • Site restoration has been completed for Phase I and site is providing desired habitats for diverse ecological resources