1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 2: PROBLEM FORMULATION
Numerous clean-up actions have occurred over the past two decades. While no formal
remediation was performed when the State Ecological Reserve was created and partially
diked (1977 to 1978), visibly contaminated soils and debris were scraped off the Reserve
areas and removed. Cleaner, but probably untested, in situ soils were used to build the
dikes around the Reserve.
Extensive remediation associated with the active oil field “waste handling facility” was
carried out in the 1980s and 1990s. More recently CalResources, now AERA Energy, working
with Signal Landmark/Koll, has remediated decommissioned oil wells, pipelines, and oil
field facilities, such as the former tank farms and gas plant, as well as accidental spills.
Under the terms of the site purchase and proposed habitat restoration agreement
(Memorandum of Agreement, October 1996, Amended December 1996 and February 1997),
portions of the Lowlands will continue to be operated by AERA Energy as an active oilfield.
If sufficient funds are available to buy out producing wells or as the wells are phased out,
closed down, and cleaned up, these active oilfield areas will also be restored fully to coastal
wetland habitats.
2.2 Ecological Characterization
Bolsa Chica is classified as a bay estuary having deepwater habitats with extensive intertidal
wetlands (Ferren, 1990; OCEMA, 1996). The Bolsa Chica Wetlands are the remnant of what
was once a vast saltwater and freshwater wetlands complex in the historic floodplain of the
Santa Ana River. The generally open and broad mouth of the bay allowed marine water to
flood the adjacent marshes at low elevation during high tide. During the winter wet season,
rainfall and streamflow dilute the marine waters; during the rest of the year, ocean water
dominates.
2.2.1 Identification of Habitats
The Lowlands include habitats that at one time supported salt marsh, brackish marsh,
freshwater marsh, open water, mudflats, dunes, and sandy flats. The present condition of
these lowland habitats has been altered and degraded by development that has removed
much of the site from tidal influence. These alterations include dike construction, road and
pad construction for oil development, and channel construction for flood control. Removal
from tidal influence has adversely affected much of the salt marsh habitat, which is now
mostly degraded or ruderal habitat (i.e., weedy species tolerant of poor soils, including
mustard, ice plant, and telegraph weed).
Habitat types found in the Lowlands are briefly described in text and are shown on Figure 2-4.
2.2.1.1 Pickleweed
Saline tidal and non-tidal areas with adequate soil moisture are dominated by pickleweed
(Salicornia virginica). Other species associated with the pickleweed salt marsh habitat include
alkali heath (Frankenia salina), saltgrass (Distichlis spicata), and annual pickleweed (Salicornia
bigelovii). In non-tidal areas, ice plant (Carpobrotus edulis) is often co-dominant.
SAC/143368(002.DOC) 2-5 ERA REPORT
7/31/02