1.1 MB pdf - Bolsa Chica Lowlands Restoration Project
1.1 MB pdf - Bolsa Chica Lowlands Restoration Project 1.1 MB pdf - Bolsa Chica Lowlands Restoration Project
SECTION 2: PROBLEM FORMULATION Pickleweed salt marsh has a high value for wildlife because of the density and structure of the vegetation. Nesting and foraging marsh birds as well as Belding's savannah sparrow (Passerculus sandwichensis beldingi) and common wildlife species, such as the great egret (Ardea albus), great blue heron (Ardea herodias), sora rail (Porzana carolina), northern harrier (Circus cyaneus), barn owl (Tyto alba), western harvest mouse (Reithrodontomys megalotis), southern California salt marsh shrew (Sorex ornatus salicornicus), and western rattlesnake (Crotalus viridis), are found in this habitat. Brackish marsh provides nesting and foraging habitat for many wetland species. Wildlife found in brackish marsh habitats at the Lowlands include the American bittern (Botaurus lentiginosus), great egret, great blue heron, black-crowned night-heron (Nycticorax nycticorax), sora rail, American coot (Fulica americana), common moorhen (Gallinula chloropus), American kestrel (Falco sparverius), northern harrier, red-winged blackbird (Agelaius phoeniceus), and salt marsh shrew. Saltgrass provides low- to moderate-quality habitat for wildlife species at the Lowlands. Species observed using this habitat include the great egret, great blue heron, sora rail, American kestrel, northern harrier, barn owl, salt marsh shrew, western harvest mouse, house mouse (Mus musculus), coyote (Canis latrans), and red fox (Vulpes vulpes). The open water habitats provide foraging, protection, and resting for diverse wildlife, especially water-dependent birds, at the Lowlands. Birds found in this habitat include the double-crested cormorant (Phalacrocorax auritus), brown pelican (Pelecanus occidentalis), California least-tern (Sterna antillarum), blue-winged teal (Anas discors), cinnamon teal (Anas cyanoptera), northern pintail (Anas acuta), American wigeon (Anas americana), mallard (Anas platyrhynchos), northern shoveler (Anas clypeata), bufflehead (Bucephala albeola), ruddy duck (Oxyura jamaicensis), greater scaup (Aythya marila), lesser scaup (Aythya affinis), and American coot. These birds forage on aquatic plants, invertebrates, and fish, and during the breeding season, some may nest in adjacent upland areas. Mudflats are used by shorebirds and wading birds, such as the American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), semipalmated plover (Charadrius semipalmatus), snowy plover (Charadrius alexandrinus), killdeer (Charadrius vociferus), greater yellowlegs (Tringa melanoleuca), willet (Catoptrophorus semipalmatus), and least sandpiper (Calidris minutilla). Gulls (Larus spp.), terns (Sterna spp.), and coots also roost and forage on non-tidal mudflats. Coastal scrub habitat is sparse and highly degraded at the site, but it can support specialstatus plant species. Terrestrial wildlife found in ruderal and coastal scrub habitats at the Lowlands include the red-tailed hawk (Buteo jamaicensis), American kestrel, white-tailed kite (Elanus leucurus), great horned owl (Bubo virginianus), mourning dove (Zenaida macroura), rock dove (Columba livia), American crow (Corvus brachyrhynchos), northern mockingbird (Mimus polyglottos), European starling (Sturnus vulgaris), western meadowlark (Sturnella neglecta), house finch (Carpodacus mexicanus), house sparrow (Passer domesticus), western harvest mouse, house mouse, coyote, and red fox. Dunes and sandy flats at the Lowlands are found mostly on islands and provide good-quality nesting and roosting habitat for shorebirds and seabirds. Birds using the dunes and sandy flats include the Caspian tern (Sterna caspia), elegant tern (Sterna elegans), Forster's SAC/143368(002.DOC) 2-7 ERA REPORT 7/31/02
SECTION 2:PROBLEM FORMULATION tern (Sterna forsteri), California least tern, western snowy plover, killdeer, and black skimmer (Rynchops niger). 2.2.2.2 Special-Status Species The California Natural Diversity Database (CNDDB) (RareFind, 1999) was used to identify special-status plant and animal species and natural community types for which records of occurrence exist on or within a 5-mile radius of the project area. Data included in the CNDDB, which is maintained by the CDFG, are compiled by opportunistic rather than systematic means and, therefore, may not include all records of species occurrences and habitats for a given area. As with the list of species expected to occur onsite, each specialstatus species was cross-referenced with information collected during site visits and reviews of published and unpublished data (CDFG, 1998; USFWS, 1990; USACE, 1995) to determine the accuracy of habitat associations, geographic distributions, and listing status. A list of special-status species potentially occurring in the Bolsa Chica Lowlands is in Table 2-2. 2.3 Chemicals of Potential Ecological Concern This section describes selection and preliminary evaluation of COPECs. The COPECs were selected as part of the Scoping Assessment (CH2M HILL, 1998b) through evaluation of existing data and comparison to available background concentrations and screening-level benchmarks, as described in the following subsections. The COPECs selected in the Scoping Assessment were used to: • Ensure that field activities detailed in the Work Plan (CH2M HILL, 1998a) would yield data sufficient to fully characterize the potential risk to ecological receptors from siterelated contaminants and activities • Provide the basis for evaluations conducted in the EEC Report and this ERA The ERA was completed using analytical results from the Phase II environmental investigation (Tetra Tech, 1996) and the ERA Sampling and Analyses and Focused Sampling and Analyses (CH2M HILL, 1998a; and 2000). Other previous investigations (Woodward Clyde, 1987; Groundwater Technology, 1989; Earth Technology, 1987, 1988, 1990; and Schaefer Dixon Associates, 1991) were considered to the extent that they are still relevant. The data from sampling conducted by Tetra Tech (1996), as well as that conducted through the CSP/ERA (CH2M HILL, 1998a and 2000) were compiled into a single ERA chemical database. The data evaluation for the ERA is presented in Section 3. Those data meeting data quality parameters were used to quantitatively and qualitatively evaluate the potential ecological risks from chemical concentrations in soil, sediment, surface water, and biota. Final chemicals of ecological concern (COECs) have been identified based on these evaluations, as described in Sections 3 and 4. 2.3.1 Preliminary Data Evaluation A list of sitewide COPECs was compiled by the Bolsa Chica Technical Committee prior to preparation of the Work Plan and the Scoping Assessment (Table 2-3). This list was expanded in the Scoping Assessment to include all chemicals detected in soils, sediments, surface water, and biota (benthic infauna, fish, terrestrial plants, and terrestrial mammals) ERA REPORT 2-8 SAC/143368(002.DOC) 7/31/02
- Page 1 and 2: REVISED FINAL VOLUME I Ecological R
- Page 3 and 4: CONTENTS 3. Analysis...............
- Page 5 and 6: CONTENTS 3-21 Summary of EC 50 s an
- Page 7 and 8: Executive Summary The Bolsa Chica L
- Page 9 and 10: EXECUTIVE SUMMARY The ERA report ev
- Page 11 and 12: EXECUTIVE SUMMARY “focused sampli
- Page 13 and 14: EXECUTIVE SUMMARY Exposure point co
- Page 15 and 16: EXECUTIVE SUMMARY sample. However,
- Page 17 and 18: EXECUTIVE SUMMARY The chemicals in
- Page 19 and 20: SECTION 1: INTRODUCTION • Sedimen
- Page 21 and 22: SECTION 1: INTRODUCTION Assessment
- Page 23 and 24: SECTION 1: INTRODUCTION Based on th
- Page 25 and 26: SECTION 1: INTRODUCTION 1.5 Organiz
- Page 27 and 28: SECTION 2:PROBLEM FORMULATION The L
- Page 29 and 30: SECTION 2:PROBLEM FORMULATION The e
- Page 31: SECTION 2:PROBLEM FORMULATION 2.2.1
- Page 35 and 36: SECTION 2:PROBLEM FORMULATION backg
- Page 37 and 38: SECTION 2:PROBLEM FORMULATION 2.4.1
- Page 39 and 40: SECTION 2:PROBLEM FORMULATION The f
- Page 41 and 42: SECTION 2:PROBLEM FORMULATION Benth
- Page 43 and 44: SECTION 2:PROBLEM FORMULATION Fish
- Page 45 and 46: SECTION 3: ANALYSIS The field sampl
- Page 47 and 48: SECTION 3: ANALYSIS CAR Sites A tot
- Page 49 and 50: SECTION 3: ANALYSIS 3.1.2 Data Eval
- Page 51 and 52: SECTION 3: ANALYSIS questionable. T
- Page 53 and 54: SECTION 3: ANALYSIS Pesticides were
- Page 55 and 56: SECTION 3: ANALYSIS copper were det
- Page 57 and 58: SECTION 3: ANALYSIS For five of the
- Page 59 and 60: SECTION 3: ANALYSIS the subsurface
- Page 61 and 62: SECTION 3: ANALYSIS 3.1.4 Exposure
- Page 63 and 64: SECTION 3: ANALYSIS 3.1.4.2 Exposur
- Page 65 and 66: SECTION 3: ANALYSIS Model The gener
- Page 67 and 68: SECTION 3: ANALYSIS 3.1.5 Exposure
- Page 69 and 70: SECTION 3: ANALYSIS The toxicity bi
- Page 71 and 72: SECTION 3: ANALYSIS The chronic tox
- Page 73 and 74: SECTION 3: ANALYSIS conductivity wi
- Page 75 and 76: SECTION 3: ANALYSIS the regression
- Page 77 and 78: SECTION 3: ANALYSIS Scatter plots a
- Page 79 and 80: SECTION 3: ANALYSIS concentrations,
- Page 81 and 82: SECTION 3: ANALYSIS dieldrin. These
SECTION 2: PROBLEM FORMULATION<br />
Pickleweed salt marsh has a high value for wildlife because of the density and structure of<br />
the vegetation. Nesting and foraging marsh birds as well as Belding's savannah sparrow<br />
(Passerculus sandwichensis beldingi) and common wildlife species, such as the great egret<br />
(Ardea albus), great blue heron (Ardea herodias), sora rail (Porzana carolina), northern harrier<br />
(Circus cyaneus), barn owl (Tyto alba), western harvest mouse (Reithrodontomys megalotis),<br />
southern California salt marsh shrew (Sorex ornatus salicornicus), and western rattlesnake<br />
(Crotalus viridis), are found in this habitat.<br />
Brackish marsh provides nesting and foraging habitat for many wetland species. Wildlife<br />
found in brackish marsh habitats at the <strong>Lowlands</strong> include the American bittern (Botaurus<br />
lentiginosus), great egret, great blue heron, black-crowned night-heron (Nycticorax<br />
nycticorax), sora rail, American coot (Fulica americana), common moorhen (Gallinula<br />
chloropus), American kestrel (Falco sparverius), northern harrier, red-winged blackbird<br />
(Agelaius phoeniceus), and salt marsh shrew.<br />
Saltgrass provides low- to moderate-quality habitat for wildlife species at the <strong>Lowlands</strong>.<br />
Species observed using this habitat include the great egret, great blue heron, sora rail,<br />
American kestrel, northern harrier, barn owl, salt marsh shrew, western harvest mouse,<br />
house mouse (Mus musculus), coyote (Canis latrans), and red fox (Vulpes vulpes).<br />
The open water habitats provide foraging, protection, and resting for diverse wildlife,<br />
especially water-dependent birds, at the <strong>Lowlands</strong>. Birds found in this habitat include the<br />
double-crested cormorant (Phalacrocorax auritus), brown pelican (Pelecanus occidentalis),<br />
California least-tern (Sterna antillarum), blue-winged teal (Anas discors), cinnamon teal (Anas<br />
cyanoptera), northern pintail (Anas acuta), American wigeon (Anas americana), mallard (Anas<br />
platyrhynchos), northern shoveler (Anas clypeata), bufflehead (Bucephala albeola), ruddy duck<br />
(Oxyura jamaicensis), greater scaup (Aythya marila), lesser scaup (Aythya affinis), and<br />
American coot. These birds forage on aquatic plants, invertebrates, and fish, and during the<br />
breeding season, some may nest in adjacent upland areas.<br />
Mudflats are used by shorebirds and wading birds, such as the American avocet<br />
(Recurvirostra americana), black-necked stilt (Himantopus mexicanus), semipalmated plover<br />
(Charadrius semipalmatus), snowy plover (Charadrius alexandrinus), killdeer (Charadrius<br />
vociferus), greater yellowlegs (Tringa melanoleuca), willet (Catoptrophorus semipalmatus), and<br />
least sandpiper (Calidris minutilla). Gulls (Larus spp.), terns (Sterna spp.), and coots also roost<br />
and forage on non-tidal mudflats.<br />
Coastal scrub habitat is sparse and highly degraded at the site, but it can support specialstatus<br />
plant species. Terrestrial wildlife found in ruderal and coastal scrub habitats at the<br />
<strong>Lowlands</strong> include the red-tailed hawk (Buteo jamaicensis), American kestrel, white-tailed kite<br />
(Elanus leucurus), great horned owl (Bubo virginianus), mourning dove (Zenaida macroura),<br />
rock dove (Columba livia), American crow (Corvus brachyrhynchos), northern mockingbird<br />
(Mimus polyglottos), European starling (Sturnus vulgaris), western meadowlark (Sturnella<br />
neglecta), house finch (Carpodacus mexicanus), house sparrow (Passer domesticus), western<br />
harvest mouse, house mouse, coyote, and red fox.<br />
Dunes and sandy flats at the <strong>Lowlands</strong> are found mostly on islands and provide<br />
good-quality nesting and roosting habitat for shorebirds and seabirds. Birds using the dunes<br />
and sandy flats include the Caspian tern (Sterna caspia), elegant tern (Sterna elegans), Forster's<br />
SAC/143368(002.DOC) 2-7 ERA REPORT<br />
7/31/02
Change language