1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 2: PROBLEM FORMULATION
(now Huntington Harbour) was cut through Bolsa Chica Mesa. Construction of berms and
dikes to enhance duck habitat (e.g., create freshwater habitat) may have resulted in
increased evapoconcentration cycles (metals, minerals, salinity from fresh, brackish, and
seawaters) in the shallower soils as waters came into the Lowlands and then slowly
evaporated during the dry season. However, the degree to which evapoconcentration may
have been impacted by construction activities has not been well documented.
Since 1920, the site and surrounding area have been used for oil and gas exploration,
production, and processing as part of the Huntington Beach Oil Field. The earliest
exploration occurred in the Edwards Thumb area at the eastern tip of the Lowlands. Oil
operations in the Lowlands did not start until the 1940s (Klancher, 1999).
An examination of aerial photographs from 1938 and 1947 indicates drainage from surrounding
areas entered the site at several locations. Discrete channels entered areas that are now
designated as Cell 63 (Freeman Creek) and Cell 66. Freeman Creek drainage would have
flowed westward through channels that are now parts of Cells 30, 18, 17, and 5 into Inner Bolsa
Bay. Drainage entering through Cell 66 would have flowed to the area that is now Cell 67.
A more generalized drainage pattern to the Lowlands appears to have existed northwest of
the area, where the Garden Grove-Wintersburg Flood Control Channel (which drains to
Outer Bolsa Bay) was subsequently constructed. Another generalized drainage pathway
(without a defined channel) appears to have entered the Lowlands from oilfield
developments east of the site. This drainage pathway would have entered the Lowlands
through what is now Cell 36.
More than 430 oil wells are on the site, including many that have been abandoned. Active
and inactive oil wells are present, primarily on earthen pads elevated several feet above the
natural grade of the Lowlands. Most of the wells are characterized by aboveground pumps
and below-grade cellars. Open, unlined sumps within the Lowlands area have been used
historically to process or dispose of oilfield wastes, including drilling muds, oil/water
separation wastes, brine, and other oily waste.
An extensive network of active, inactive, and abandoned oil and gas pipelines criss-cross the
site along the elevated oil roads. Most of the main transmission pipelines are aboveground
in the Lowlands area, except for shorter pipelines from individual wells to the main
transmission lines, which are sometimes underground. Two gas lines that carry petroleum
products from offsite locations traverse the site.
Three tank farms (the North Bolsa Tank Farm, the South Bolsa Tank Farm, and the State Lease
Tank Farm) and related structures and equipment yards were formerly present in the project
area. The tank farms, which were at the eastern side of the project area, have been removed.
Soil contamination has been associated with each of the tank farms (Steffeck, et al., 1996).
Until recently, a gas plant operated on the Huntington Beach Mesa adjacent to the eastern
edge of the property. The gas plant processed condensate from onsite and offsite production.
Contamination by condensate has been detected in the soil beneath the old gas plant.
Ancillary operations to petroleum production include an outdoor sand blasting and spray
painting area on the eastern Lowlands. A helipad is on the Huntington Beach Mesa (outside
the property boundary); an underground jet fuel tank and underground waste tank are
associated with the helipad (OCEMA, 1994).
SAC/143368(002.DOC) 2-3 ERA REPORT
7/31/02