HomeMy WebLinkAboutChevron2.0 Project Description
May 2010 i Chevron Tank Farm Project EIR
Administrative Draft
Table of Contents
2.0 Project Description........................................................................................................... 2-1
2.1 Background and Current Site Operations...................................................................... 2-4
2.1.1 Historical Use......................................................................................................... 2-4
2.1.2 Current Conditions ................................................................................................. 2-6
2.2 Proposed Remediation Activities ................................................................................ 2-11
2.2.1 Regulatory Agency Involvement ......................................................................... 2-11
2.2.2 Proposed Remediation Actions Overview ........................................................... 2-15
2.2.2.1 Monitoring .................................................................................................... 2-15
2.2.2.2 Excavation .................................................................................................... 2-15
2.2.2.3 Caps .............................................................................................................. 2-18
2.2.3 Project Areas Specific Remediation Plans ........................................................... 2-18
2.2.3.1 Operable Unit #1 – Northwest Area ............................................................. 2-19
2.2.3.2 Operable Unit #2 – Reservoirs 5 and 7 ......................................................... 2-21
2.2.3.3 Operable Unit #3 – Reservoir 4 and Flower Mound Area ........................... 2-22
2.2.3.4 Operable Unit #4 – Remaining Site-Wide Terrestrial and Wetland Areas .. 2-24
2.2.3.5 Operable Unit #5 – Site-Wide Groundwater ................................................ 2-28
2.2.4 Building and Structure Demolition ...................................................................... 2-29
2.2.5 Pipeline Decommissioning .................................................................................. 2-30
2.2.6 Miscellaneous Cleanup ........................................................................................ 2-32
2.2.7 Construction Methods .......................................................................................... 2-34
2.2.7.1 Mobilization, Staging Areas, Truck Transport and Access .......................... 2-34
2.2.7.2 Borrow-Area Excavations ............................................................................ 2-38
2.2.7.3 Excavation Procedures and Quantities ......................................................... 2-42
2.2.7.4 Site Grading .................................................................................................. 2-43
2.2.8 Remediation Schedule, Employee, and Traffic Details ....................................... 2-45
2.2.9 Long-Term Monitoring Activities ....................................................................... 2-46
2.3 Restoration .................................................................................................................. 2-48
2.3.1 Earthwork ............................................................................................................. 2-49
2.3.2 Planting and Seeding............................................................................................ 2-52
2.3.3 Irrigation .............................................................................................................. 2-53
2.3.4 Weed Control ....................................................................................................... 2-53
2.4 Development Options .................................................................................................. 2-53
2.4.1 City Development Plan ........................................................................................ 2-54
2.4.1.1 City Plan Overview ...................................................................................... 2-54
2.4.1.2 City Option Construction Requirements ...................................................... 2-61
2.4.1.3 City Development Option Operations .......................................................... 2-63
2.4.2 County Development Option ............................................................................... 2-64
2.4.2.1 County Plan Overview.................................................................................. 2-66
2.4.2.2 County Option Construction Requirements ................................................. 2-66
2.4.2.3 County Development Option Operations ..................................................... 2-67
2.5 Project Permitting Requirements ................................................................................ 2-69
2.5.1 City Project .......................................................................................................... 2-69
2.5.1.1 Specific Plan Amendment ............................................................................ 2-69
2.5.1.2 General Plan Amendment ............................................................................. 2-70
2.5.1.3 City Vesting Tentative Tract Map (Tract No. 2981) .................................... 2-71
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Chevron Tank Farm Project EIR ii May 2010
Administrative Draft
2.5.1.4 Pre-Zoning and Annexation .......................................................................... 2-71
2.5.1.5 Other City Permits (Grading) ....................................................................... 2-71
2.5.1.6 Development Agreement .............................................................................. 2-71
2.5.2 County Project ..................................................................................................... 2-73
2.5.2.1 General Plan Amendment/Zone Change ...................................................... 2-73
2.5.2.2 County Vesting Tentative Tract Map (Tract No. 2988). .............................. 2-73
2.5.2.3 Conditional Use Permit (Grading) ................................................................ 2-74
2.5.3 Other Potential Permits ........................................................................................ 2-74
2.0 Project Description
May 2010 iii Chevron Tank Farm Project EIR
Administrative Draft
List of Figures
Figure 2-1 Project Location ................................................................................................... 2-2
Figure 2-2 Project Site ........................................................................................................... 2-3
Figure 2-3 Project Site Existing Pipelines ............................................................................. 2-9
Figure 2-4 Airport Safety Zones .......................................................................................... 2-10
Figure 2-5 Water Monitoring Wells and Netted Areas ....................................................... 2-12
Figure 2-6 Project Site Existing Affected Areas ................................................................. 2-13
Figure 2-7 Proposed Remediation Areas ............................................................................. 2-17
Figure 2-8 Reservoir 5 and 7 Remediation Proposed Cap Section ..................................... 2-23
Figure 2-9 Reservoir 4 Remediation Proposed Cap Section ............................................... 2-24
Figure 2-10 Reservoir 3 Remediation Proposed Cap Cross Section ..................................... 2-27
Figure 2-11 Miscellaneous Cleanup Areas ............................................................................ 2-33
Figure 2-12 Proposed Work Areas, Staging Areas, and Site Access .................................... 2-35
Figure 2-13 Proposed Truck Routes ...................................................................................... 2-37
Figure 2-14 Proposed Borrow Sites ....................................................................................... 2-40
Figure 2-15 Restoration Planting Plan ................................................................................... 2-51
Figure 2-16 Typical Creek Cross Section .............................................................................. 2-52
Figure 2-17 Site Zoning under the City AASP ...................................................................... 2-55
Figure 2-18 Proposed Project Development Plan .................................................................. 2-56
Figure 2-19 Proposed Project Land Use Designations and Bike Paths ................................. 2-57
Figure 2-20 City Development Option Phasing .................................................................... 2-62
Figure 2-21 Existing County Land Use Designations ........................................................... 2-65
Figure 2-22 County Development Option Phasing ............................................................... 2-68
Figure 2-23 Tentative City Tract Map ................................................................................... 2-72
Figure 2-24 Tentative County Tract Map .............................................................................. 2-75
List of Tables
Table 2-1 Proposed Remediation by Operable Unit .......................................................... 2-19
Table 2-2 Borrow Site Quantities ....................................................................................... 2-41
Table 2-3 Area Grading and Excavation Quantities .......................................................... 2-44
Table 2-4 Employee Requirements for Remediation ......................................................... 2-45
Table 2-5 Equipment Requirements for Remediation ........................................................ 2-45
Table 2-6 Peak Remediation Traffic Levels....................................................................... 2-46
Table 2-7 Development Plan Summaries ........................................................................... 2-59
Table 2-8 Detailed Development Plan Worst Case Mix .................................................... 2-59
Table 2-9 Development Construction Equipment (per phase) ........................................... 2-63
Table 2-10 City Option Build-Out Water Use and Traffic .................................................. 2-63
Table 2-11 City Option Traffic Generation by Phase .......................................................... 2-64
Table 2-12 County Plan Build-Out Water Use and Traffic.................................................. 2-67
Table 2-13 County Option Traffic Generation by Phase ..................................................... 2-69
Table 2-14 San Luis Obispo City Development Option Comparison of Existing AASP and
Proposed Land Use and Acres ........................................................................... 2-70
Table 2-15 San Luis Obispo County General Plan Amendment/Zone Change Comparison of
Existing and Proposed Land Use and Acres ...................................................... 2-73
Table 2-16 Anticipated Federal, State and Local Permits .................................................... 2-76
2.0 Project Description
May 2010 2-1 Chevron Tank Farm Project EIR
Administrative Draft
2.0 Project Description
Chevron owns the 332-acre former tank farm property (Project Site), south of the City of San
Luis Obispo (City), in San Luis Obispo County (County), California (see Figure 2-1). This
Project Site was originally owned and operated by Unocal. Chevron purchased Unocal, including
this Project Site, in August 2005. The San Luis Obispo Tank Farm was constructed in 1910 to
serve as the tidewater accumulation point for the petroleum pipeline from the San Joaquin
Valley. In 1926, many of the tanks on the Project Site were destroyed in a fire created by a
lighting strike. This Project Site was slowly withdrawn from operation during the later decades
of the twentieth century, and by the late 1990s it was formally decommissioned. The Project Site
now exists as primarily vacant land that is effectively surrounded by the urban development of
the City of San Luis Obispo and the San Luis Obispo County Regional Airport (SLOCRA).
Chevron intends to remediate the Project Site to address site contamination issues, restore and
improve the ecological function of the habitat, and develop portions of the Project Site consistent
with a proposed land use plan.
The Project consists of two principal components: remediation and development. The
remediation and restoration component includes several activities: demolishing existing
buildings, excavating top soil, site recontouring, capping, and mitigating existing impacts to
wetland and rare plant habitats. Recontouring would be done mostly using on-site materials. The
Flower Mound, the former quarry site in the northeastern corner of the Project Site (see Figure 2-
2), would be the principal borrow source for soil materials. This area is comprised of
metavolcanic rocks and serpentinite. It is anticipated that this area would need to be blasted in
order to break up and access this material.
The second component of the Proposed Project involves developing portions of the Project Site
through entitlements for commercial or industrial uses. Chevron’s goal is to develop a portion of
the Project Site with approximately 800,000 square feet (floor area) of business park.
Developments would be executed in five phases over a period of approximately 25 years; each
phase would create approximately 160,000 square feet of leasable floor area and take
approximately five years to construct. The development phase would only occur after the
remediation phase of the Proposed Project is completed.
The proposal includes designation of approximately 15 acres for recreational use to be developed
by others. The Project Site is included in the City’s Airport Area Specific Plan (AASP) that
anticipates future annexation of this and other properties in the area given its proximity to
existing City boundaries, existing industrial uses, and the SLOCRA. In addition, the City’s
AASP requires the environmentally sensitive portions of the Project Site – comprised of
approximately 250 acres – be kept in open space. Chevron is proposing a Development
Agreement for consideration by the City Council in association with a potential annexation of the
Project Site. In the event the City Council ultimately approves a Development Agreement, the
process for adoption of such an agreement and the annexation of the Project Site would be
lengthy and would require the approval of several long-term development and phasing plans.
Given the nature of the Development Agreement and annexation processes, Chevron has filed a
land division map application with both the County and City. As such, Chevron is proposing two
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Figure 2-1 Project Location
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Figure 2-2 Project Site
Source: AVOCET 2007
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separate development options, one consistent with County regulations and one consistent with
City regulations. The objective of the dual project approach by Chevron is to provide an
alternative development option in the event the review and approval process for annexation and
development is unsuccessful or does not meet Chevron’s needs. Approved development would
either be under County or City jurisdiction, and such approvals would follow approval of
required amendments to the County General Plan and the City’s Airport Area Specific Plan
AASP). The Proposed Project will be processed simultaneously in the City and County
jurisdictions. The City and County serve as California Environmental Quality Act co-lead
agencies in processing the Proposed Project and preparation of the Environmental Impact Report
EIR). It is likely that the Project-related work that includes grading and remediation will occur
while under County jurisdiction, and development and construction would occur once the Project
Site is annexed to the City.
The applicant for the remediation and restoration component of the Proposed Project is Chevron
Environmental Management Company. The applicant for the purpose of the land planning and
development component is Chevron Land and Development. Both companies are located at 4051
Broad Street in San Luis Obispo.
This EIR evaluates the remediation project, which would occur under County jurisdiction, as
well as both the City and County development options with suitable alternatives. Information for
the remediation and development options is based on the Remedial Action Plan (AVOCET
2007), the Project Execution Plan (Chevron 2007), and Chevron’s responses to the EIR
preparer’s information requests.
2.1 Background and Current Site Operations
The Chevron Project Site is immediately south of the City of San Luis Obispo, San Luis Obispo
County, California (see Figure 2-1). The address of the San Luis Obispo Tank Farm is 276 Tank
Farm Road. The County of San Luis Obispo Assessor’s Parcel Numbers for the Project Site are
076-351-037, 076-351-040, and 076-351-037-041; 076-352-061 and 076-352-062; and 076-381-
021, 076-382-005, 076-383-001 and 076-383-002.
The Project Site is divided into north and south sections by Tank Farm Road (see Figure 2-2); it
is bordered by light commercial and industrial development, the SLOCRA, agricultural and
pastoral lands with scattered residences, and a mobile home park. The existing buildings in the
northwest part of the Project Site were used as Chevron’s local headquarters for a variety of
environmental and remediation operations. The buildings are proposed for demolition as part of
the Proposed Project.
2.1.1 Historical Use
From 1910 until the early 1980s, the Project Site stored crude oil transported from the San
Joaquin Valley via pipeline. Storage facilities at the Project Site included six large earthen
reservoirs, ranging in capacity between 775,000 and 1,350,000 barrels (bbl), and 21 steel
aboveground storage tanks (AST), each with a 55,000 bbl capacity. By 1926 only 15 tanks
remained. The reservoirs were constructed by excavating a circular or elliptical depression,
which was then lined with concrete reinforced with wire mesh. The walls were also reinforced
concrete, but they were constructed either vertically or integrated into the sloping sides of the
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depression. The walls and floors of the AST were constructed of heavy plate steel secured with
rivets. The roofs of both the reservoirs and AST were wood and composition. All together, the
Project Site had capacity to store more than 6 million bbl of petroleum.
On April 7, 1926, a lightning strike ignited a fire at the Project Site. At that time, 933,577 bbl of
oil were stored in the AST, and another 5,374,927 bbl of oil were stored in the reservoirs. The
total inventory was 6,308,504 bbl of various grades of oil. Eyewitnesses claim that a lightning
strike simultaneously ignited the vapors in Reservoirs 5, 6, and 7. The power of the resulting
explosion registered on the Weather Bureau barograph in downtown San Luis Obispo at 7:35
a.m. A second lightning strike ignited Reservoir 3 sometime between 7:50 and 7:55 a.m.
Despite suppression efforts by the facility staff, over the next four days the fire spread to the
other reservoirs and to 12 of the existing 15 steel AST with a combination of burning embers and
boil-overs, where the heated oil flowed out of the reservoirs and onto the ground surrounding the
tanks. By April 11, 1926, all but a few thousand of the 6 million bbl inventory was released,
some of which burnt to coke and spread across the Project Site. Petroleum coke is defined as a
black solid residue, obtained mainly in refineries by cracking (burning) of residue feedstocks.
The burning of the heavy oil during the fire had a similar effect to the refining cracking process,
creating the coke. This release is considered responsible for most of the numerous surface
occurrences (i.e., expressions) of highly weathered and burned petroleum that cover the ground
in topographically low areas of the Project Site.
Subsequently, Unocal (now Chevron) resumed operations at the Project Site, including
reconstructing ten of the steel AST and Reservoirs 3, 4, 5, and 6. Reservoirs 2 and 7 were never
used again for petroleum storage. The reconstruction effort included expanding the firebreaks
and enlarging the containment areas surrounding the reservoirs, which created numerous
hydraulically closed depressions around the Project Site that subsequently became wetlands.
In addition to the reservoirs and AST utilized for petroleum storage, the facility included a series
of pipelines to move oil to and from the Project Site and between the onsite tanks and facilities.
Regional pipeline operations were also conducted at the Project Site, primarily from the
Northwest Area of the Project Site (see Figure 2-2). Facilities to support pipeline operations
included a pumphouse, boilers (for heating crude oil to reduce viscosity) and an associated blow-
down area (a blow-down area safely depressurizes the system in the event of an emergency), a
petroleum physical properties testing laboratory, and an electrical equipment house. The
Northwest Area also included areas for general equipment storage and maintenance, as well as
underground storage tanks (UST) that contained diesel fuel and gasoline (England, Shahin &
Associates 1994). The UST were removed in 1987.
Other historical activities at the Project Site include the operation of a fire training school in the
unpaved eastern portion of the Northwest Area. The school consisted of several simulated
sumps, flares, and tanks where students practiced techniques for extinguishing petroleum-fed
fires. Off-specification gasoline and diesel fuel were fed to these fixtures from a set of three AST
via a system of buried metal pipes.
The four reservoirs repaired after the 1926 fire continued in service for several more decades, but
they were progressively decommissioned from the late 1950s through the mid 1970s.
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Field evidence suggests that decommissioning involved emptying the reservoirs of liquid
petroleum and removing the roofs and removing the vertical walls at Reservoirs 3 and 4. The
reinforced concrete covering the sloping slides and bottoms was left in place. In Reservoirs 2, 5,
and 7 there is evidence that the concrete bottoms were ripped by the shank of a bulldozer in
perpendicular directions. The bottoms of the remaining reservoirs have not been directly
observed, so it is uncertain whether these were similarly ripped. The bottoms of Reservoirs 2 and
7 were ripped by Unocal in the mid 1990s in an attempt to prevent water from accumulating in
the former reservoirs. Reservoirs 3 and 4 were largely backfilled by bulldozing the berms into
the center of the reservoirs. Reservoir 4 generally contains 5 to 6 feet of non-engineered fill and
construction debris above the concrete bottom, and Reservoir 3 is estimated to contain between 8
and 11 feet of non-engineered fill. To provide access, a portion of the berms surrounding
Reservoirs 5, 6, and 7 has been pushed into the reservoirs. Approximately 1.5 feet of non-
engineered fill and construction debris cover the bottoms of Reservoirs 5 and 6, and in Reservoir
7 the berm debris was not distributed evenly across the reservoir bottom, but rather was left as an
apron near the notch. Most of the bottom of Reservoir 7 is covered by several inches of
interlayered tar and organic debris.
A review of historical aerial photographs shows that the ten steel AST remaining or rebuilt after
the 1926 fire were decommissioned at various times. Aboveground storage tank 522, in the
Northwest Area, was removed sometime between 1959 and 1965. Eight of the nine remaining
AST were removed in 1994 and the last AST was reserved for fire water storage. The final AST
was removed in August 2000. Fire school exercises were suspended at the Project Site in the
1970s and transferred to the Richmond Refinery. The pumphouse, pipelines, and boilers were
taken out of service in the early 1990s and were demolished or decommissioned in the late
1990s. Of the original Tank Farm structures, only three buildings remain.
For several years, approximately 2 acres of land near the center of the Project Site north of Tank
Farm Road was leased to a recycling company. The area was used as a transfer station and
accumulation point for recyclable materials, such as paper, glass, and aluminum. The operation
was shut down and removed in mid 2000, when the lease expired and was not renewed (England
Geosystem, Inc. 2001).
2.1.2 Current Conditions
Aside from the existing, vacant office buildings in the northwestern portion of the Project Site,
the Project Site is undeveloped land that contains native grasslands and both natural wetlands
and wetlands from water accumulation in depressions associated with the former oil storage
facility (see Figure 2-2).
At the Project Site, topography, soils, and vegetation have been altered considerably through
plowing and disking, catastrophic fire, grazing of domestic livestock, construction and removal
of oil storage tanks and their surrounding berms, stream channelization, construction of water
and oil management and containment systems, and several other anthropogenic alterations.
Currently, most of the Project Site is dominated by non-native species of forbs and grasses.
However, some scrub/shrub and forested plant communities occur in wet depressions or within
riparian corridors associated with the East Fork of San Luis Obispo Creek and its tributaries.
Waters of the U.S., including wetlands, in the forms of riverine, depressional, and small slope
ecosystems are prominent throughout the Project Site. Many of the waters/wetlands on the
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Project Site are associated with natural features such as swales, small riverine channel systems,
or depressions. However, some of the depressional and slope wetlands are associated with
human-made depressions that remain after decommissioning of oil storage facilities or after
various mining or domestic livestock management operations.
The most recent wetlands study determined that there are 49 acres of wetlands under federal
Clean Water Act (CWA) jurisdiction. Another combined total area of 3.9 acres are otherwise
called “’other waters’ of the U.S.” Therefore, total area of waters/wetlands under federal CWA
jurisdiction at the Project Site is 52.9 acres.
There are isolated depressional features mapped on the Project Site that are not under federal
CWA jurisdiction because they either have (1) no connection with, or adjacency to, traditionally
navigable waters, and/or (2) no significant nexus with interstate commerce or maintenance of the
physical, biological, or chemical integrity of downstream waters. However, these wetland
features support special status species that are protected at federal and/or state levels of
jurisdiction. Total area of waters/wetlands not under federal CWA jurisdiction, but which do
support special status species is 15.8 acres. Finally, fifteen (15) wet depressional features
mapped on the Project Site do not support any special status species. Their combined total area is
3.4 acres (Padre, WSP 2008).
The disturbed rock outcrop (i.e., former quarry site known as the “Flower Mound”) exists in the
northeastern corner of the Project Site and contains a mixture of serpentinite rock outcrops along
the upper slopes and clay-loam soils along the lower slopes. Several areas of the Project Site
where surface expressions of petroleum exist have been enclosed with netting to protect birds
and other animals from becoming mired in the material. The Project Site is best characterized as
open space, with cattle grazing for fire prevention and weed control. Adjacent land uses include
light commercial and industrial development, the SLOCRA, agricultural and pastoral land with
scattered residences, and a mobile home park.
Some modifications and improvements have been made to the Northwest Area since the last
petroleum-dedicated AST were decommissioned in 1994. These included upgrades to the front
gate, the addition of a modular office building adjacent to the northernmost original building, a
new fire-water tank to replace the water storage AST decommissioned in 2000, and various
upgrades to the electrical and telecommunication systems.
Utility companies provide natural gas, electricity, and telecommunication service to the Project
Site or have lines that cross the Project Site. The Gas Company owns a 4-inch diameter gas line
located just north of Tank Farm Road. The line is buried in the shoulder of the road and
terminates approximately 400 feet from the west boundary of the Northwest Area. A 2-inch
diameter gas line splits off the main line and runs underground along the western property line
for approximately 500 feet. That branch line provides natural gas service to the Northwest Area.
Aerial lines also run parallel to Tank Farm Road, offset to the north approximately 100 feet from
the road centerline. The aerial lines include electrical power provided by Pacific Gas and Electric
Company and telecommunications service provided by AT&T. Electricity and
telecommunications services also branch off the main lines at the west boundary of the
Northwest Area, and run along the western property line. A new lift station and larger gravity
sewer lines were installed by the City on Tank Farm Road and put into service in July, 2009. The
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Chevron Tank Farm Project EIR 2-8 May 2010
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new pump station replaced two aging stations. The new sewer lines were installed along Broad
Street between Rockview Place and Tank Farm Road and on Tank Farm Road at Broad Street.
Historical operations at the Project Site were served by approximately 25,125 feet of crude oil
pipeline, 47,340 feet of water supply line, and 1,172 feet of other pipeline. Figure 2-3 shows the
approximate locations of these lines. It is believed that most of the lines were abandoned in
place, although anecdotal reports suggest that much of the pipeline serving the AST was
removed when the tanks were removed. Since there is no record of final cleaning or
abandonment procedures, it is presumed that at least some of the lines still contain crude oil.
Crude oil pipelines vary in diameter from 8 to 16 inches. It appears that the most common
diameter is 8 inches; using this as a nominal diameter for the entire network suggests that the
crude oil pipeline volume is approximately 16,750 cubic feet. It is unlikely, however, that this
volume of oil remains in the lines. Many of the lines are demonstrably empty where they are
exposed on the surface.
Much of the facility piping is found in the Northwest Area, as shown in Figure 2-3. This includes
nearly 20 percent of the total crude oil pipe network (approximately 4,300 linear feet). This
configuration allowed the operators to direct oil in and out of the facility and to transfer oil
between the various storage locations as needed. There are also 4,900 feet of water line, 1,120
feet of dedicated Foamite fire-fighting lines, and leach and drain lines totaling slightly less than
1,200 feet. The estimated volume of the crude oil lines in the Northwest Area is approximately
3,260 cubic feet.
The Project Site is located beneath the departure pattern for Runway 11-29 of SLOCRA, which
extended Runway 29 by approximately 500 feet in 2001. This expanded the airport safety zones
beyond those originally considered in the City’s AASP. The State of California Department of
Transportation’s Airport Land Use Planning Handbook provides recommendations, based on
runway length, for the size and configuration of aviation safety zones, those safety zones are
depicted in Figure 2-4. Additional discussion of the Airport Safety Zones is provided in Section
4.11, Hazards and Hazardous Materials. These expanded zones place additional restrictions on
approximately 14.6 acres of the City’s AASP proposed building area. Furthermore,
environmental studies subsequent to the City’s AASP provided more detailed information
regarding location of contamination and sensitive and endangered species on the Project Site.
For example, protected habitat for Vernal Pool Fairy Shrimp (VPFS) was identified in several of
the former tank rings north of the Northwest Area. Consequently, Chevron has proposed
revisions to the existing City land use plan consistent with these post-AASP in depth studies. A
detailed description of the proposed amendments to the City’s AASP is included in Section
2.5.1.1, Specific Plan Amendment.
Current deliveries and visits to the Project Site occur sporadically, with an average of one truck
per quarter-year to haul debris, visits by contractors two to four times per month to inspect
netting enclosures and complete routine maintenance activities, and two persons visiting the
Project Site approximately 20 days per year for groundwater, stormwater, and surface water
monitoring.
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Figure 2-3 Project Site Existing Pipelines
Source: Padre 2007
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Figure 2-4 Airport Safety Zones
Source: Modifications to the Airport Land Use Commission for San Luis Obispo County 2005 by the City of SLO
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Ongoing monitoring at the site includes groundwater monitoring of wells, surface water
monitoring and the installation and monitoring of netting that encloses areas of impacted surface
water. These activities are guided by the Surface Hydrocarbon Inspection and Mitigation Plan
SHIMP). The netting is installed to prevent impacts to bird populations. The netted areas are
monitored on a weekly basis. Cumulative impacts on birds at the netted areas between March
2007 and January 2009 indicate that 58 birds were netted with 5 bird fatalities. Figure 2-5 shows
the water monitoring wells and the areas covered with netting.
2.2 Proposed Remediation Activities
The remediation portion of the Proposed Project addresses soil and groundwater contamination
identified as potential human health or ecological risks as agreed by the resources agencies
reviewing the proposed remedial actions for the Project Site. The Proposed Project would also
address existing impacts to wetland and rare plant habitats from contamination, and those
unavoidable impacts that would result from implementing the remedial actions. The petroleum-
related impacts affecting the Project Site include oil found as far as 60 feet below ground surface
bgs) and, at the surface, crude oil expressions that range from solid asphalt-like coke to a low-
density non-aqueous phase liquid (LNAPL). Figure 2-6 shows the locations and nature of the
contamination within the Project Site.
The following sections describe the involvement of the regulatory agencies in the remediation
design, an overview of the proposed remedial actions, a detailed description of remedial actions
to be taken in specific areas of the Project Site, a description of the demolition of existing
structures, a depiction of how pipelines will be decommissioned, a description of miscellaneous
cleanup slated to take place at the Project Site, details of the construction methods to be used, a
discussion of the Proposed Project schedule and a detailed description of the long term
monitoring activities.
2.2.1 Regulatory Agency Involvement
Petroleum released as a result of the 1926 fire and prior and subsequent Project Site operations
have impacted soil and groundwater underlying the Project Site. Chevron, along with its
predecessors, conducted several investigations over the course of nearly two decades to study the
soil, groundwater, and surface water conditions at the Project Site to assess the nature and
distribution of hydrocarbons in soil and groundwater. These investigations include multiple
events of soil, soil gas, surface water, and groundwater sampling; well installation activities; and
non-aqueous phase liquid (NAPL) evaluation. Analytical testing has been performed for total
petroleum hydrocarbons (TPH); benzene, toluene, ethyl benzene, and total xylenes (BTEX);
other volatile organic compounds (VOC); fuel oxygenates; polynuclear aromatic hydrocarbons
PAH); polychlorinated biphenyls (PCB); pesticides and herbicides; metals; and general
minerals. In addition to soil and groundwater investigations, there have been additional field
studies focusing on soil gas profiling, natural attenuation, aquifer and product recovery testing,
and hydrocarbon seep studies. Specifically, many investigations focused on the nature and
occurrence of surface petroleum hydrocarbons present throughout the Project Site, primarily
those that are either liquid or display evidence of recent plastic flow, which, are the principal risk
drivers at the Project Site. Figure 2-6 summarizes the petroleum hydrocarbon-containing soil and
groundwater and metals-containing soil areas at the Project Site.
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Figure 2-5 Water Monitoring Wells and Netted Areas
Source: Padre 2009
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Figure 2-6 Project Site Existing Affected Areas
Source: AVOCET 2007
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Characterization of these impacts has included, in addition to their identification and delineation,
an evaluation of their importance relative to human and ecological health and the need for their
remediation. Key to this effort has been the cooperative process between Chevron, regulatory
agencies, and local municipalities that have reviewed data, evaluated assessments, identified data
gaps, established the risk associated with a given impact, and determined which impacts require
remediation.
In order to validate the characterization process, Chevron entered two cooperative programs
intended to foster regulatory participation and third-party expert review. The first of these
collaborative processes was the Remediation Technology Panel (RTP), established through a
cooperative agreement between Chevron and the Regional Water Quality Control Board
RWQCB). The RTP consisted of three experts drawn from academia with expertise in the
characterization and remediation of petroleum-impacted sites, whose purview focused on soil-
and groundwater-related issues. They identified data gaps within the existing site
characterization, guided and reviewed subsequent characterization activities, and published a
report summarizing their consensus understanding of subsurface issues at the Project Site (RTP
2006).
The second of these cooperative processes, the Surface Evaluation, Remediation, and Restoration
Team (SERRT), was established to oversee and direct risk assessment and risk management
activities. The SERRT was comprised of two principal groups, the Human Health Risk Working
Group (HHRWG) and the Ecological Risk Working Group (ERWG). Both groups included
Chevron, its representatives, and the RWQCB, but the HHRWG also included the California
Office of Environmental Health Hazard Assessment, the San Luis Obispo County Environmental
Health Division, and the San Luis Obispo County Air Pollution Control District (APCD); and the
ERWG added a biologist from the City of San Luis Obispo and a representative from the
California Department of Fish and Game (CDFG). In addition to reports documenting the human
and ecological risk assessments, the SERRT prepared a consensus summary document listing its
recommendations for risk management at the Project Site (BBL 2005). To focus risk assessment
efforts, certain areas of the Project Site, principally those impacted by sticky or liquid surface
expressions of petroleum, were excluded from the risk assessments with the understanding that
something would be done to mitigate the risk in those areas.
Chevron’s participation in the SERRT process is a departure from a typical remediation project
where an applicant proposes a cleanup plan and government agencies then accept it or reject it.
In this case, the SERRT has brought all the parties together to develop cleanup plans with buy in
from the different agencies. As a result, cleanup efforts are being pursued without the issuance
of a Clean and Abatement Order from the RWQCB.
The culmination of the characterization efforts was the Risk Management Summary, which
identified those impacts to the Project Site requiring remediation. These included surface liquid
hydrocarbons impacting seasonal wetlands in Reservoirs 5 and 7, plastic surface hydrocarbons
found across the Project Site (mostly in low-lying areas), groundwater impacted by LNAPL and
benzene, arsenic in soil, asphalt impacting wetlands, and the potential for methane to affect
habitable structures. The following sections describe the areas impacted and the proposed
remediation treatment for specific sites.
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More recently, as a result of the peer review conducted as part of the preparation of this
document, it was determined that additional site assessment was necessary to address concerns
that the large fire of 1926 at the Project Site likely produced dioxins, which have not been
adequately characterized. Consequently, Chevron has prepared a work plan to evaluate the on-
site concentrations of dioxins and furans in shallow soils, and to compare those results to off-site
ambient sample concentrations to identify whether dioxins generated by the 1926 fire are present
in surface soils at the site at concentrations greater than ambient soil conditions. The results of
the additional assessment would dictate whether additional remediation is necessary, if dioxins
are present at elevated levels, and additional environmental review would have to be conducted
to analyze the potential impacts of that added remediation.
2.2.2 Proposed Remediation Actions Overview
General remedial actions proposed as part of the remediation phase of the Proposed Project
include long-term monitoring, natural attenuation, excavation and offsite transport, and capping.
Figure 2-7 shows the areas proposed for monitoring, excavation, and capping.
2.2.2.1 Monitoring
The principal monitoring activity is groundwater sampling and reporting to ensure against offsite
migration of petroleum products. Long term monitoring is discussed in detail in Section 2.2.9
below. The monitoring program currently requires sampling of onsite and offsite wells (see
Figure 2-5 for a map of monitoring wells). Chevron currently samples the wells required by the
RWQCB on a semiannual basis. Samples are tested for extractable range hydrocarbons, and
some samples from well monitoring are also tested for purgeable range hydrocarbons and BTEX.
A few samples are analyzed for all three constituent types.
The preferred remedial alternative for some areas is monitored natural attenuation with
institutional controls and long-term monitoring. Monitored natural attenuation includes
semiannual sampling of the existing groundwater monitoring network; testing those samples for
total extractable petroleum hydrocarbons (TEPH). Monitored natural attenuation (MNA) is the
degradation of organic contaminants by naturally occurring microbes in the subsurface. Periodic
testing of soil vapor at the Project Site is proposed to document the degradation of contaminants.
This technology is used for TPH- and PAH impacted subsurface soil. TPH is amenable to
intrinsic biodegradation and other attenuation processes in the subsurface; however,
biodegradation of heavier TPH is slow.
Long-term monitoring would also include periodic inspections of the caps and excavation areas.
Caps are discussed in more detail in Section 2.2.2.4 below. This would be done to ensure those
remedies continue to function properly and are achieving the remedial action objectives.
Chevron proposes that inspections occur on a semiannual basis. In particular, Chevron proposes
that one inspection should occur just prior to the rainy season and the other during or just after
the rainy season. Long-term monitoring would also evaluate habitat potential.
2.2.2.2 Excavation
Some impacted near-surface soils, mostly those affected by petroleum with the risk of wildlife
entrapment, would be excavated. These selective excavations have been chosen to either improve
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the function of a capping system or to mitigate an identified ecological risk. When performed in
conjunction with the construction of a cap, the excavation would remove a limited amount of
material defined by an excavation depth (e.g., 2 feet) or by exposure of some existing feature
e.g., a former reservoir bottom).
Field investigations conducted for Chevron have shown that the isolated pockets of plastic
hydrocarbon identified for removal are the byproducts of the fire or operational spills and appear
to be localized to within 3 to 4 feet of the ground surface. In the event that these impacts are
determined to extend locally to depths greater than 5 feet, it is proposed that removal excavations
would be limited to a depth of 5 feet below ground surface (bgs). Four issues were evaluated by
Chevron in defining this limitation: worker safety, the potential to encounter groundwater,
mitigating risk to burrowing animals, and ensuring that plastic hydrocarbon does not resurface at
some later date. Excavations beyond 5 feet in depth could be potentially dangerous to workers.
Special standards exist requiring planning and support for worker safety, based on the
requirements of the U.S. Occupational Safety and Health Administration (OSHA) and the
California Division of Occupational Safety and Health (Cal/OSHA). In addition, Chevron
maintains that excavations beyond 5 feet in the low-lying areas of the Project Site are likely to
encounter groundwater.
One objective of the remedial design is to ensure that future open space uses of the Project Site
do not pose an unacceptable risk to potential ecological receptors, which include birds and
burrowing animals. The proposed limit for excavation is below the burrowing depths of most
animals that will likely be encountered at the Project Site (DTSC 1996). Further protection could
be provided by using a 0.75-inch gravel for the first 6 inches of backfill to act as a barrier to
burrowing animals, if deemed necessary. Chevron studies also indicate that 5 feet of compacted
backfill would prevent resurfacing of the plastic materials and that the materials are viscous and
generally appear to mobilize only when exposed to the warming effects of direct sunlight
England Geosystem, Inc. 2001). By removing material from the near-surface and replacing it
with a well-compacted backfill, the studies indicate that the likelihood that the material would
resurface is very low. Soil used for backfill would be compacted to 90 percent of its relative
maximum density as determined by ASTM International (ASTM) Method D1557. Remediation
would include long-term monitoring and maintenance of the Project Site. In the event that plastic
hydrocarbons were to resurface, they would be detected by the long-term monitoring program
and further remedial steps would be taken as part of Project Site maintenance.
Groundwater remediation is not included as part of Chevron’s proposal because it was
determined by the SERRT that the groundwater contamination did not exceed action levels and
was not moving offsite. There is no evidence of hydrocarbon impacts to down gradient
groundwater beneficial uses, and groundwater in the airport area is not used for drinking. It was
concluded by the SERRT that monitored natural attenuation is sufficiently protective to be
adopted as the long-term remedy for groundwater.
As proposed by Chevron, clean materials, those not impacted by plastic hydrocarbon, would be
segregated during excavation, stockpiled locally, and reused as common earth backfill. Common
earth may include solid asphaltic hydrocarbon. Materials impacted by plastic hydrocarbon would
be disposed of at an appropriate offsite location.
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Figure 2-7 Proposed Remediation Areas
Source: AVOCET 2007
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However, the rate of disposal that could occur once traffic and air quality impacts are considered
during the environmental analysis is uncertain. Assuming that there are no constraints on truck
trips, impacted soils would be loaded directly onto a truck and hauled offsite. An alternative
would be to stockpile the impacted material onsite and remove it at a rate that does not unduly
burden local streets or air quality.
The Northwest Area would be used as a staging area, if needed, to stockpile contaminated soil
prior to loading on trucks for offsite disposal. The Northwest Area would be capped and later
developed. It is estimated that remedial actions could generate up to 157,000 cubic yards of
impacted soil. If necessary, however, a secondary stockpile could be located on the south side of
the Project Site, adjacent to the gate on the existing paved slab. It is likely that this area would
store equipment or materials. This area would be available for impacted soil stockpiling if
crossing Tank Farm Road to access the central staging area is seen as being problematic. The
paved area is slightly more than an acre, and the stockpile would be limited in capacity to
approximately 15,000 cubic yards.
2.2.2.3 Caps
Caps would cover impacted materials and separate them from potential human and ecological
receptors. They would be constructed from earthen materials, but may also include various
geosynthetic materials for additional strength or material separation. In addition, caps would
support either open space or development land uses.
A distinction between the open space and development caps is that the former would include a
topsoil layer that would support revegetation. The development caps may be vegetated to
minimize erosion, but that would be done directly on the structural fill. The revegetation would
also be of a temporary nature, and it would be maintained in place only long enough to minimize
potential soil loss in the interim prior to development. The development caps would be
constructed of structural fill with a minimum thickness of 4 feet. Conversely, the open space
caps would be more varied due to their differing design objectives and individual site constraints.
Typical cap figures are provided later in this document under the discussion of the remediation
of the different Operable Units.
2.2.3 Project Areas Specific Remediation Plans
Based on the different types of contamination at the Project Site and the potential remediation
efforts, five Operable Units (OU) were developed for the Project Site, shown in Figure 2-7. A
brief description of each OU and the Areas of Concern (AOC) within each one of the OUs as
appropriate is provided in the sections below, accompanied by a discussion of the associated
proposed remedy. These descriptions are largely taken from the Avocet Feasibility Study
prepared for Chevron (Avocet 2007), but have been edited to reflect the current plan to pursue
the development options, where applicable, and to reflect refinement of the City’s AASP land
use zones. Table 2-1 lists the operable units, areas of concern, and the proposed remedies.
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Table 2-1 Proposed Remediation by Operable Unit
Operable Unit Area of Concern Proposed Remedy
1 – Northwest Area
1 – LNAPL/BTEX-Impacted
Groundwater Natural Attenuation + IC + LTM
2 – Surface Soils Capping + IC + LTM
2 – Reservoirs 5 & 7 NA Capping + IC + LTM
3 – Reservoir 4 NA Capping/Excavation + IC + LTM
4 – Remaining Site-Wide
Surface and Subsurface Soils
1 – North Marsh Area Excavation + IC + LTM
2 – Reservoir 3 Capping + IC + LTM
3 – PPSH Areas Excavation + IC + LTM
5 – Site-Wide Groundwater - Natural Attenuation + IC + LTM
Notes: LNAPL = Light Non-Aqueous Phase Liquid; BTEX = Benzene, Toluene, Ethylbenzene, Xylene; IC =
Institutional Controls; LTM = Long-Term Monitoring; PPSH= Pliable Petroleum Surface Hydrocarbons; NA = Not
Applicable.
Source: AVOCET 2007
2.2.3.1 Operable Unit #1 – Northwest Area
Operable Unit #1 encompasses approximately 5 acres in the Northwest Area of the Project Site
designated as service/manufacturing land use (see Figure 2-7). Historically, this area was used to
support tank farm and pipeline operations and included equipment and processes not found
across the remainder of the Project Site. Consequently, this area is affected, at least in part, by a
unique group of contaminants, namely arsenic in shallow soil and LNAPL with a lighter fraction,
including BTEX, in the saturated zone.
In addition, a portion of this area of the Project Site is designated in both the City and County
General Plans for future commercial development. Although the area zoned for commercial
development in either land use plan includes all or portions of the northwest corner of the Project
Site, including the former AST containment berms, the area of OU #1 excludes the AST berms
due to the identified value of the Vernal Pool Fairly Shrimp (VPFS) habitat that they support.
This area also lies within the 100-year floodplain.
Operable Unit #1 includes two areas of concern (AOC): groundwater (AOC #1) and soil (AOC
2). Due to a set of conditions unique to the Northwest Area, the LNAPL in the saturated zone
also contains a light fraction (lighter hydrocarbon in the C5-C20 range), including benzene. This
light fraction is responsible for the Northwest Area being the only area of the Project Site
identified by the RTP where groundwater containing dissolved contaminants (TPH and benzene)
at concentrations greater than maximum contaminant levels (or frequently applied action levels)
has migrated offsite. The LNAPL impact in the Northwest Area covers an area approximately
600 feet long by 300 feet wide and ranges in depth from 4 to 28 feet bgs (see Figure 2-6). The
light fraction co-occurs with, and is dissolved in, the heavier oil. Light-end hydrocarbons,
including BTEX, are hundreds of times more soluble in oil than in water. Therefore, this light
fraction would be difficult to remove without also removing the heavier residual oil. In the
Northwest Area, groundwater typically occurs at depths ranging from 5 to 15 feet bgs.
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Benzene is the most toxic constituent of BTEX and its presence in soil, groundwater, and soil gas
may be a potential risk to future users of the Project Site if not addressed. The Feasibility Study
described the circumstances surrounding the presence and discovery of the BTEX in detail
AVOCET 2007). In summary, a human health risk assessment determined that the BTEX does
not pose a significant risk to building occupants, provided adequate controls (e.g., vapor barriers)
are in place (McDaniel Lambert 2004).
Area of Concern #2 includes shallow soil in OU #1, which is impacted by arsenic and, to a more
limited extent, by TPH and polynuclear aromatic hydrocarbons (PAH), and deeper (4 to 28 feet
bgs) soil impacted by the above-described LNAPL. Within the OU, the arsenic is relatively
widespread and limited to shallow (less than 2 feet) soil, which is consistent with its likely use as
an herbicide. The arsenic was identified as a potential human health risk for both open space and
commercial development land uses. It is assumed that the entire operable unit is impacted with
arsenic, subject to remediation given the available spatial distribution of data. A detailed
description of the two areas of concern (AOCs) under this Operable Unit is provided below.
Area of Concern #1 – Groundwater
Chevron studies indicate that benzene dissolved in groundwater has historically migrated off site,
but rapidly attenuates and does not appear to threaten down-gradient water wells. The remedial
action objectives for OU #1 and AOC #1 established in the Feasibility Study intend to prevent
human contact with TPH- or benzene-impacted groundwater and ensure that groundwater
resources down-gradient of existing impacts are not affected. Chevron proposes that monitored
natural attenuation is sufficiently protective as the long-term remedy for groundwater in OU #1
and AOC #1 since the LNAPL is considered stable and difficult to recover; the dissolved phase
is naturally contained; there is no evidence of hydrocarbon impacts to offsite, down-gradient
groundwater beneficial uses; and groundwater in the airport area is not used for drinking.
Therefore, the proposed remedial alternative for AOC #1 is monitored natural attenuation with
institutional controls and long-term monitoring onsite and offsite. Monitored natural attenuation
includes regular sampling of the existing groundwater monitoring network on and surrounding
AOC #1; chemical analyses on collected samples; and reporting findings to the RWQCB in
accordance with an approved monitoring and reporting program.
Institutional controls would include deed restrictions limiting land use to commercial and
industrial purposes, a soil management plan implemented in the event contaminated soils are
disturbed, and groundwater use restrictions in impacted areas.
Area of Concern #2 – Soil
Area of Concern #2 includes shallow soil, which is impacted by arsenic and, to a more limited
extent, by TPH and PAH, and deeper (4 to 28 feet bgs) soil impacted by LNAPL containing a
light fraction. The arsenic is relatively widespread and limited to shallow (less than 2 feet) soil,
which is consistent with its probable former use at the Project Site as an herbicide. The arsenic
and PAH have been identified as potential threats to human and ecological receptors (if the area
were converted to open space). With regard to the deeper soil, the LNAPL was not considered a
direct contact risk, but vapor intrusion by the volatile fraction may pose a risk to future on-site
commercial workers. Remedial action objectives were primarily focused on preventing human
and ecological receptor contact with arsenic, TPH, PAH, and volatile hydrocarbons. Since the
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area is proposed to be developed, it would not support suitable ecological habitat, thereby
mitigating the potential for ecological risks.
The proposed remedy for OU #1 and AOC #2 includes constructing a soil cap, a minimum of 4
feet in thickness. The cap would provide a barrier between the impacted soil and potential
receptors and also provide a soil layer of sufficient thickness to facilitate foundation construction
and utility installation. The Northwest Area is within the 100-year flood plain associated with
Tank Farm Creek. At its current grade, the southernmost structure within the Northwest Area is
subject to inundation during periods of moderate to heavy rain. Raising the ground elevation by 4
feet and re-grading appropriately would also satisfy the requirements for construction in
floodplains and help alleviate the current flooding problems. A geotextile, placed between the
cap and the existing ground surface, would act as an identifying marker to reduce the likelihood
of inadvertently excavating into the impacted soils. See Appendix A for detailed figures on
OU#1.
The cap would require long-term monitoring and maintenance. Institutional controls would
include deed restrictions limiting land use to commercial and industrial purposes; excavation
notification requirements; a soil management plan; groundwater use restrictions in impacted
areas; and a vapor barrier requirement for any new buildings constructed in the OU, which would
protect the building occupants from possible vapors from the underlying hydrocarbons.
2.2.3.2 Operable Unit #2 – Reservoirs 5 and 7
Operable Unit #2 includes the former Reservoirs 5 and 7. Measured from the outside toe of the
reservoir containment berms, the reservoirs cover a total area of 9.8 acres. The reservoirs contain
approximately 8.5 acres of wetland, none of which are identified VPFS habitat. Reservoir 5
contains local communities of Congdon’s tarplant. Both reservoirs contain ponded water from
rising groundwater elevations during the winter. In years of heavy rainfall, it is not unusual for 2
to 3 feet of water to accumulate in the reservoirs. The reinforced concrete bottoms are still
present in both of the reservoirs but they are ripped and covered by 1 to 2 feet of tar, non-
engineered fill, and construction debris. In both the City and County land use plans, Reservoirs 5
and 7 appear in areas designated as Open Space (see Figure 2-7).
Reservoirs 5 and 7 are unique because they are the only areas of the Project Site impacted by
liquid-type hydrocarbon surface expressions, and these are the only surface expressions
hydraulically connected to subsurface LNAPL sources. Therefore, simply removing the shallow
hydrocarbon-impacted soils would not effectively remediate the sheen that seasonally develops
on surface water in the reservoirs. The source of the hydrocarbon sheen is hydrocarbon materials
that extend to depths of up to 25 feet below the bottom of the reservoirs. During periods of rain,
the water table rises coming in contact with the hydrocarbons and creating the sheen, and
pushing hydrocarbon to the surface. Elimination of the sheen would require either removal of the
mobile hydrocarbon below ground, making that hydrocarbon immobile, or filling the bottom of
the reservoirs to elevations above the seasonal water table highs (RTP 2006).
The proposed remedy involves capping Reservoirs 5 and 7, mitigating impacts in other on-site
areas, institutional controls, and long-term monitoring. Cap construction would involve
removing existing non-engineered fill down to the existing concrete floor in each reservoir.
Gravel would then be placed directly on top of the existing concrete floor in each reservoir 1.5
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feet above each reservoir’s historic (1990 to 2005) high water-table elevation. The gravel would
be covered with a layer of geotextile and a combination of common earth fill and topsoil to
create the finished surface. The cap would be graded to encourage runoff, thereby minimizing
water infiltration into the gravel reservoir. A cap cross section is shown in Figure 2-8. This
remedy assumes that wetlands that exist in reservoirs would not be restored in the reservoir areas
but, rather, in other suitable areas of the Project Site. Consequently, it would be necessary to
create additional wetlands elsewhere on site. Institutional controls would depend on the level of
public access, but are expected to include fencing, signs, awareness programs, and similar active
measures to control access to the Project Site. Other institutional controls would include deed
restrictions and other covenants as needed to preserve the land as open space in perpetuity.
Long-term monitoring would include periodic inspections and maintenance as needed to ensure
that the institutional controls and cap remain effective.
2.2.3.3 Operable Unit #3 – Reservoir 4 and Flower Mound Area
Operable Unit #3 includes approximately 30 acres in the eastern part of the Project Site that is
zoned for future commercial development for both the City and the County (see Figure 2-7). This
operable unit includes Reservoir 4, several surface expressions of sticky hydrocarbon that
collectively cover an area of approximately 2.3 acres, and the area of the former recycling center.
The floor of former Reservoir 4 is covered with 5 to 6 feet of non-engineered, hydrocarbon-
impacted soil and construction debris. The Risk Management Summary recommended that soil
within Reservoir 4 be left in place with no further action, assuming that the area remains open
space. However, due to the entrapment hazard posed by the sticky hydrocarbon surface
expressions, the ERWG identified these areas, together with some proximal expressions that are
not physical hazards, for remediation. Operable Unit #3 contains several small areas of wetlands,
none of which are VPFS habitat, and at least two special status plants: Congdon’s tarplant and
San Luis Obispo morning glory. Finally, three areas of relatively low Level 2 ecological risk
were identified in the former recycling center, but because the area is paved and does not provide
suitable ecological habitat, the Risk Management Summary recommended no further action
provided that the site is utilized for other uses.
For purposes of the Feasibility Study evaluation, the development scenario was defined as
including all of the activities necessary to leave the OU in a condition such that a developer
could undertake construction. For OU #3, this is potentially significant since there are several
feet of non-engineered fill within Reservoir 4 anticipated to be incapable of supporting a
conventional spread footing building foundation without adverse differential settlement.
Consequently, the Feasibility Study considered remedial alternatives that would support high
foundation loads by removing and replacing the non-engineered, hydrocarbon-impacted fill
within Reservoir 4, as well as development alternatives that would require minimal structural
support, such as a parking lot.
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Figure 2-8 Reservoir 5 and 7 Remediation Proposed Cap Section
Weathered, high-molecular weight TPH-impacted soil extends to depths of up to 50 feet below
Reservoir 4. Since no significant risk has been attributed to the presence of this material, and
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considering the impracticability of contaminant removal, remedial measures targeting this
material were not considered in the Feasibility Study.
Subsequent to the Feasibility Study, a refinement of the land uses shown in the City’s AASP has
been proposed by Chevron. The proposed remediation for OU #3 provides a soil cover over
Reservoir 4 that is at least 4 feet thick, and as much as 11 feet thick. The cover would provide a
barrier between the impacted soil and potential receptors and also sufficient structural support for
future onsite construction. A geotextile identifying layer, placed between the cap and the existing
ground surface, would reduce the likelihood of inadvertently excavating into the impacted soils.
See Figure 2-9 for a cross section of the cap proposed for Reservoir 4. Landscaped areas of the
cover would be planted with appropriate shallow-rooted vegetation to prevent erosion without
penetrating the cover. Development would still require the installation of vapor barriers below
any future foundations or slabs to protect against potential methane intrusion.
Since residual contamination would remain at depth, institutional controls would minimize the
potential for future onsite exposures and long-term monitoring would assess compliance and
effectiveness.
Figure 2-9 Reservoir 4 Remediation Proposed Cap Section
2.2.3.4 Operable Unit #4 – Remaining Site-Wide Terrestrial and Wetland Areas
Operable Unit #4 includes all the remaining terrestrial and wetland areas of the Project Site not
considered in the first three operable units. Operable Unit #4 covers approximately 270 acres and
all but 24 acres is planned open space.
Three areas of concern were defined in OU #4 corresponding to “must-do” areas identified by
the SERRT (see Figure 2-7):
AOC#1 – the North Marsh;
AOC#2 – Reservoir 3; and
AOC#3 – Other sticky hydrocarbon surface expressions.
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The SERRT identified all of these areas due to the presence of sticky hydrocarbon surface
expressions. However, the conditions surrounding the occurrence of these surface expressions in
each area of concern are subtly different, necessitating individual review. Over 70 acres of
wetland occur in OU #4, including more than 30 acres identified as VPFS habitat. The OU also
includes substantial coverage by a variety of special status plants.
The Risk Management Summary also recommended two areas of surface hydrocarbon
expressions surrounding Reservoir 3, which were not identified as ecological risks, for ripping to
facilitate re-vegetation. These areas would be scarified to depths of not less than 15 inches. A
detailed description of the remedies proposed for these Areas of Concern is provided below.
Area of Concern #1 – North Marsh
Area of Concern # 1, the North Marsh, is approximately 11.9 acres of wetlands, without VPFS
habitat, east of the Northwest Area. The wetlands include the most extensive coverage of pliable
plastic hydrocarbon surface expressions at the Project Site. When grouped into areas based on
proximity, these expressions cover about 7 acres. The extent of contamination in the shallow
subsurface, however, may be significantly greater. Based on the 1926 topography of the North
Marsh, these surface expressions may cover as much as 13 acres. The thickness of the
expressions varies, but has been estimated to be 2 to 3 feet on average. The North Marsh has not
been identified as VPFS habitat.
The proposed remedy is to excavate the plastic hydrocarbon surface expressions from the North
Marsh, dispose of the impacted material off-site, and improve upon the existing wetland
function. The area of excavation is estimated between 7 and 13 acres, with an average assumed
excavation depth of 3.5 feet. Given the areas and thickness, the excavation may generate
anywhere from 40,000 to 73,000 cubic yards of material. Any material identified as clean would
be stockpiled separately and used later as backfill.
It is anticipated that the petroleum hydrocarbon-containing soil excavated from the North Marsh
area would be disposed of as nonhazardous hydrocarbon contaminated soil at an appropriate
landfill (see Section 2.2.2.3 for more detail). It is assumed that the upper 1 foot of soil would be
replaced with appropriate organic-rich topsoil, consisting either of clean soil from on-site or
imported to the Project Site.
Once the excavation and backfill operations are complete, the marsh would be replanted to
restore wetland function. Institutional controls may include fencing, signs, awareness programs,
and similar active measures to control access to the area. Other institutional controls might
include deed restrictions or other covenants that would maintain the wetlands in perpetuity.
Long-term monitoring would include a monitoring and maintenance program to ensure that those
controls remain effective.
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Area of Concern #2 – Reservoir 3
Area of Concern #2 includes 8.4 acres within the footprint of former Reservoir 3. Much of the
ground surface within the former reservoir area is covered by pliable hydrocarbon surface
expressions with wildlife entrapment hazard potential. Studies have demonstrated that
groundwater is not responsible for the hydrocarbon surface expressions in this former reservoir.
These studies have determined that viscous oil is being slowly squeezed from the mixed
reservoir fill as the soil slowly settles. The reservoir is filled with 8 to 11 feet of non-engineered
fill, including berm soils, construction debris, and tar. Approximately 4 acres of precipitation and
runoff-supported wetlands hosting VPFS habitat form seasonally along the inside edges of the
former reservoir.
The proposed remediation activities consist of constructing a geosynthetic and soil cap that
would establish a permanent barrier between contaminated soil and potential human and eco-
receptors. The cap would isolate the contamination from the surface and attempt to reestablish
wetlands in the same area, thus minimizing the amount of habitat that must be created elsewhere
on the Project Site. Conceptually, the cap would be constructed by removing a minimum amount
of hydrocarbon-impacted soil so that the cap can be installed without significantly changing the
existing grades. Non-hazardous hydrocarbon contaminated soil would be disposed of at an
appropriate landfill (see Section 2.2.2.3). Since the remaining reservoir fill material is non-
engineered and, at best, has poor bearing capacity, it would be necessary to support the cap with
various soil and geosynthetic materials. A geotextile would be laid over the exposed work
surface and anchored in a trench excavated around the perimeter of the work area. A tri-
directional geo-grid anchored in a 1-foot thick gravel layer would distribute loads as evenly as
possible and limit settlement to the cap center. A flexible membrane liner protected above and
below by geotextiles would create the impermeable barrier. The primary function of the flexible
membrane would prevent downward migration of water, which may help support wetland habitat
in a manner similar to the current condition. The final component of the cap would be an
overlying thickness of common fill and organic-rich topsoil, which would be contoured to mimic
the existing topography and wetland hydrology. See Figure 2-10 for a cross section of the cap.
Remediation may unavoidably impact as much as 3.9 acres of Vernal Pool Fairy Shrimp (VPFS)
habitat. Institutional controls may include fencing, signs, awareness programs, and similar active
measures to control access to the site. Other institutional controls might include deed restrictions
or other covenants that would maintain the habitat in perpetuity. Long-term monitoring would
include periodic inspections and maintenance, as needed, to ensure that the institutional controls
and cap remain effective.
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Figure 2-10 Reservoir 3 Remediation Proposed Cap Cross Section
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Chevron Tank Farm Project EIR 2-28 May 2010
Administrative Draft
Area of Concern #3 – Pliable Surface Expressions of Petroleum
Area of Concern #3 includes approximately 3 acres of sticky hydrocarbon surface expressions in
six general areas on the southern portion of the Project Site. These surface expressions occur in
topographically low areas that accumulated petroleum during the 1926 fire. These expressions
are limited in extent by surrounding berms and are 2 to 3 feet thick on average. Because these
expressions are in topographically low spots, many occur within wetlands, some of which
include protected VPFS habitat.
The remediation of OU #4/AOC #3 consists of excavating the plastic hydrocarbon surface
expressions, disposing of the contaminated material off site, and restoring the original grade. The
remediation activities would also restore the existing wetland function, create additional
wetlands on site to reach the expected mitigation requirements, establish institutional controls,
and provide long-term monitoring. The wetlands impacted by the remediation would be restored
within the remediation area.
Institutional controls may include fencing, signs, awareness programs, and similar active
measures to control access to the Project Site. Other institutional controls might include deed
restrictions or other covenants that would maintain the wetlands in perpetuity. Long-term
monitoring would include periodic inspections to ensure that those controls remain effective.
2.2.3.5 Operable Unit #5 – Site-Wide Groundwater
Operable Unit #5 includes site-wide groundwater, exclusive of the Northwest Area (see Figure 2-
7). Groundwater flows toward the southwest at an average rate of about 100 feet per year and
primarily within subsurface sandy interbeds in the largely fine-grained valley fill. The major
potential source areas for petroleum impacts to water quality in OU #5 are the LNAPL areas
underlying the former reservoirs (reservoirs 2, 3, 4, 5, 6 and 7). Groundwater monitoring of OU
5 has been conducted continuously since 1990, both on and off the Project Site, through a
network monitoring wells (see Figure 2-5). For the most part, these samples were tested for TPH
and BTEX, although a significant number were also tested for PAH. With respect to TPH, there
is no maximum contaminant level (MCL); the RWQCB regulates this contaminant on a case-by-
case basis but often ascribes 1,000 micrograms per liter (µg/L) as a reasonable action level. A
study of the OU #5 monitoring record indicates that 43 percent (414) of the samples tested for
TPH contained detectable (<100 µg/L) concentrations. These concentrations range from 100 to
1,600 µg/L, with a median concentration of 220 µg/L. The majority of detected concentrations
range between 100 and 400 µg/L, with some between 400 and 1,000 µg/L. Only two out of the
966 samples tested for TPH contained concentrations greater than 1,000 µg/L, and neither of
these was verified by resampling. Benzene has never been detected (<0.5 µg/L) in an OU #5
monitoring well.
Therefore, there is no direct evidence in OU #5 of off-site migration of dissolved contaminants in
excess of MCL or the frequently applied RWQCB TPH action level of 1,000 µg/L. These
findings, together with those of the groundwater natural attenuation monitoring program, suggest
that natural processes are attenuating any dissolved hydrocarbons generated in OU #5 within a
few hundred feet of the source.
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Therefore, the proposal for OU #5 under this Project would be monitored natural attenuation
with institutional controls and long-term monitoring. Monitored natural attenuation includes
regularly sampling of the existing groundwater monitoring network on and surrounding OU #5,
testing those samples for TPH and natural attenuation parameters, and reporting these findings to
the RWQCB in accordance with an approved monitoring and reporting program.
Institutional controls would include deed restrictions limiting land use to open space and
commercial and industrial purposes and groundwater use restrictions in and adjacent to impacted
areas. Land use restrictions may also be required on the adjacent Betita Property, south of the
Project Site, due to the localized presence of petroleum in the subsurface.
2.2.4 Building and Structure Demolition
Four buildings at the Project Site in the Northwest Area would be demolished during
remediation. Three of these buildings were constructed to support former operations at the
Project Site, but are now primarily vacant office space. The fourth, a modular building adjacent
to the northernmost original building, was constructed within the last five years to provide
additional office space.
Given the age of the three older buildings, Chevron is assuming that lead-containing materials
and asbestos-containing materials (ACM) are present. Consequently, surveys and abatement
would precede physical demolition of the buildings. A California-licensed Asbestos Consultant
and California-certified Lead Consultant, respectively, would conduct asbestos and lead-based
paint surveys for each building. Positive surveys would require abatement.
Prior to abatement, a National Emissions Standard for Hazardous Air Pollutants demolition
notification form, asbestos survey report, and an asbestos abatement work plan would be
submitted to the San Luis Obispo County APCD. Asbestos-containing materials would be abated
in accordance with local, state, and federal regulations. Any suspect material found during
abatement and not previously identified would be presumed ACM unless contradicted by
specific laboratory data. Asbestos-containing materials would be properly wrapped, placed in
covered roll-off bins, and disposed of at a licensed disposal facility (e.g., Kettleman Hills).
Once abatement activities are completed, recyclable or potentially reusable materials would be
removed. The building structure would be demolished using excavators. Some of the buildings
have metal structural elements or siding, which would be segregated for recycling, if economical.
Other materials would be loaded into haul trucks for disposal. Concrete foundations would be
broken apart using a hydraulic hammer and removed. It is possible that concrete would be
crushed and used as gravel elsewhere on the Project Site.
Utility lines would be disconnected and abandoned. Where lines are aboveground, they would be
removed. Where utility service is brought to a building underground, the line would be cut at a
point at least 2 feet below grade and capped. Service lines that use pipes or conduits greater than
4 inches diameter (e.g., water, sewer) would be filled with cement grout. Voids created in the
existing grade by demolition would be backfilled with structural fill or gravel.
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Demolition activities would also occur in other locations throughout the Project Site. These
include the removal of existing infrastructure, such as concrete walls, barb-wire fencing, and
concrete foundations. Demolition activities would occur at the following locations:
Reservoirs 3, 4, 5, and 7;
The Flower Mound;
The North Marsh; and
Other Areas (e.g., debris piles, concrete vault).
2.2.5 Pipeline Decommissioning
When operational, the Project Site required numerous pipelines to move oil between the pump
house, boilers, tanks, and reservoirs. The Project Site was also served by water, natural gas, and
septic lines. Figure 2-3 shows pipeline locations based on historical facility drawings. It is
estimated that more than 25,000 feet of oil pipeline were installed onsite; approximately 4,500
feet are found in the Northwest Area.
Chevron intends to abandon most of the existing pipelines in place. Portions of lines that are
within work areas would be removed for disposal, except for the Northwest Area, where the
pipelines may be closed in place by pressure-grouting. If a pipeline crosses an environmentally
sensitive area (e.g., wetland) and would not otherwise be disturbed by remediation activities, it
would also be closed in place by pressure-grouting. All pipelines would be flushed and, if
possible, pigged to remove residual hydrocarbon and vapors prior to abandonment. Pigging in
pipeline maintenance refers to the practice of using pipeline inspection gauges or 'pigs' to
perform various operations on a pipeline, including the use of devices to remove solid or semi-
solid deposits or debris from the pipeline. The devices are inserted into the pipeline and pushed
through and received at the other end where the debris collected from the pipeline would
accumulate. If a section of pipeline is in such poor condition that it cannot be adequately cleaned,
it would be excavated and removed in its entirety.
Pipeline Inventory
The locations of the pipelines shown in Figure 2-3 have not been field verified. While these
figures are reasonable approximations of their locations, final remediation would require more
accurate information. It is expected that prior to abandonment a detailed field survey would be
performed to locate the lines and characterize their contents. Potholes would be dug at key
locations (e.g., ends, transitions, junctions, and valves) to expose the pipe and determine its
diameter and materials of construction. Line tracing would be performed using an appropriate
geophysical instrument operated by a trained technician. The alignment of the pipeline would be
flagged every 5 feet. Pothole and flag locations would be recorded using a high-precision Global
Positioning System unit and entered into a Geographic Information System database. A detailed
pipeline inventory, noting location, depth, size, materials of construction, and condition, would
be created to guide abandonment activities.
Given the interconnected, and possibly deteriorated, web of pipelines within the Northwest Area,
Chevron may elect to cut the lines at the operable unit boundary and completely remove them
from its interior. In this case, the lines would be removed in accordance with the procedures
presented below after their locations have been confirmed.
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Pipeline Flushing and Pigging
Water trucks attached to portable pumps would be connected via hose to each petroleum pipeline
segment within the facility. Additionally, several portable storage tanks or vacuum trucks would
be stationed and attached to the pipelines to receive and collect the flush water. Each pipeline
segment would be flushed with an adequate volume of water to remove residual oil from the
pipelines. Pipeline flushing operations would continue until flush water containing total
petroleum hydrocarbons of less than 100 parts per million is achieved.
The pipeline segments that may be suitable for pigging would be identified by Chevron during
the initial potholing activities. The pigging operations would be basically the same for each
pigging run segment. The maintenance tool or pipeline pig, is introduced into the line via a pig
trap, which includes a launcher and receiver. Without interrupting flow, the pig is then forced
through it by product flow, or it can be towed by another device or cable. Usually cylindrical or
spherical, pigs sweep the line by scraping the sides of the pipeline and pushing debris ahead.
Each segment would have a beginning location where the pig is “launched” and an end section
where the pig is “received.”
First, the launching and receiving locations would be prepared for the procedure. Buried ends of
the pipeline would be excavated. The excavations would vary depending on the depth of the
pipe, but should not typically exceed an area larger than 7 feet wide by 12 feet long (84 square
feet) and no more than 5 feet deep. A trench box may be used to minimize the area affected by
the excavation.
The pipeline fluids would be drained from the pipe and the pipe would then be cold-cut to gain
access to the pipe. The pig launcher and receiver would then be attached to the exposed pipe
ends.
Once the pig launcher and receiver are attached to the pipeline, the subject pipe segment would
be pigged. The pigging operation would involve the use of scraper-type or foam pigs. The
scraper pig is constructed to help remove any remaining hydrocarbons from the inside walls of
the pipeline as it moves down the pipe. Liquefied nitrogen gas or compressed air would push the
pigs through the piping segment.
At the receiving end, vacuum trucks would remove any liquids from the pipe as the liquids are
pushed ahead of the pigs. Carbon filtration canisters would treat any vapor emissions generated
during pipeline purging operations, in accordance with APCD requirements. Chevron would
obtain approval from APCD for the proposed activities. Recovered hydrocarbons and water from
the pigging operation would be properly disposed of or recycled.
There is the possibility that a pig may become lodged in the pipe by an obstruction. If the pig
becomes obstructed along a pipe segment, the field crews would identify these locations.
Excavation activities may be required to remove the pig and the damaged or obstructed section
of pipe.
Pipeline Grouting
Pipelines that are scheduled for abandonment with diameters greater than 4 inches would be
grouted with a cement-slurry to prevent any future ground subsidence from pipe wall collapse. A
portable grout pump would pump grout into the pipeline segments. Grout would be pumped until
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Administrative Draft
it exits the other end of the pipe segment. Following grouting, the pipeline segment ends would
be backfilled with soil and the soil compacted.
Pipeline Segment Removal
Chevron proposes to remove piping within the Project Site that may be affected by project
remediation activities or is determined to be in poor condition. If practical, the pipeline segments
would be flushed or pigged prior to removal. The pipeline segment endpoints would be isolated
and cut. The pipeline segment would then be uncovered by excavating a trench to the existing
pipeline depth. As the pipeline is removed from the trench, a spill containment device would be
placed under the pipeline end to catch any residual fluids in the containment. All liquids drained
from the piping into the containment device would be removed using a vacuum truck and hauled
to an approved facility for disposal or recycling. The pipe segments would then be cut into
manageable pieces, the pipe ends wrapped in plastic to prevent spillage, the segments removed
from the trench, and the trench backfilled. Scrap pipe would be temporarily stored in bins and
transported off site for recycling.
2.2.6 Miscellaneous Cleanup
Four locations on site have been identified as requiring cleanup or demolition that are not part of
one of the OU or AOC. They are not generally “contaminated” or impacted areas, although they
may have some impacted soil associated with them. These areas are comprised of debris or
abandoned structures that are unattractive or possible physical hazards (see Figure 2-11).
Three of the locations are on the parcel north of Tank Farm Road. There are two debris piles
along the north property line. They appear to contain mostly concrete debris. As with other
concrete debris, the contractor may crush this material and reuse it for gravel elsewhere on the
Project Site. Otherwise, the concrete would be hauled off-site for recycling or disposal.
The other area identified on the parcel north of Tank Farm Road is the historical debris disposal
area adjacent to the North Marsh. This material in this area would be excavated and removed for
disposal or recycling as appropriate. The limits and characteristics of the waste would be defined
prior to excavation and disposal. It is assumed that the debris extends to a depth of 5 feet and that
the nominal excavation volume is 18,000 cubic yards. Material removed from the excavation
would be segregated on the basis of how it would be managed. Concrete would be recycled, as
described previously. Other construction debris would be sent to a solid waste landfill for
disposal. Impacted soils would either be sent to the proposed stockpile area for later disposal or
directly to the landfill designated for disposal. The excavation would not be backfilled in order to
accommodate habitat mitigation later in the project.
The fourth miscellaneous cleanup location is south of Tank Farm Road, adjacent to Reservoir 6.
It is a concrete vault of uncertain purpose, approximately 5 feet wide, 12 feet long, and 8 feet
deep. The crude oil supply line serving Reservoirs 6 and 7 connected to it, but it is not known if
it was a separator, a valve box, or served some other purpose. The vault is open and presents a
physical hazard to people and animals and a possible wildlife entrapment hazard. The steel hand
rail would be removed and the upper 3 feet of the concrete wall would be broken and used to fill
the bottom of the vault. A sand-cement slurry would fill the void spaces. The remaining depth of
the vault would be backfilled with common fill until the original grade is reestablished.
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Figure 2-11 Miscellaneous Cleanup Areas
Source: AVOCET 2007
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2.2.7 Construction Methods
Construction methods address issues such as mobilization, staging areas, site access, transport of
contaminated material, utilities, borrow areas, site grading, and chemical usage.
2.2.7.1 Mobilization, Staging Areas, Truck Transport and Access
Mobilization
Mobilization activities include moving equipment and support trailers onsite, improving site
access, installing storm water and dust control Best Management Practices, and creating habitat
protection measures. To successfully accomplish this work, the contractor would require ready
access to the work areas with ample traffic routes. At the same time, the contractor must also
minimize impacts to non-work areas and avoid sensitive habitat areas that must be preserved.
Figure 2-12 shows the anticipated work areas and the proposed staging areas and access routes.
The work areas are the limits within which remediation activities would be conducted for a given
OU or AOC. The work area limit would be generally defined by the extent to which a particular
site must be cleared and grubbed to properly perform the work and provide the contractor with
sufficient room to move equipment and materials.
Staging Areas
Chevron has identified three main and four auxiliary staging areas at the Project Site (see Figure
2-12). The main staging areas would be at the former recycling area, the Northwest Area, and the
Southern Staging Area. Major maintenance (e.g., engine repair, fluid changes) would only be
performed at the primary staging areas in specially prepared areas with proper spill control
measures in place. Four auxiliary staging areas identified for use during remediation activities
are at the four operable unit areas. The auxiliary staging areas would be directly adjacent to the
work areas and would be used to stage materials, park equipment, and other support activities.
Vehicles and equipment would be fueled and undergo minor maintenance (e.g., changing tires) at
the local staging areas.
Internal access routes have been chosen to use existing roads and thereby avoid sensitive habitat.
These routes may require widening and drainage improvement (see Figure 2-12). A flagman or
other means of traffic control would be provided, as necessary, at the proposed Tank Farm Road
crossing. In operating a stockpile for impacted soil, it would be necessary to comply with local
air quality and traffic regulations. This would likely require covering the stockpile and periodic
monitoring to keep volatile organic compound emissions within regulatory limits. It would also
be necessary to control dust and minimize stockpiling during the rainy season.
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Figure 2-12 Proposed Work Areas, Staging Areas, and Site Access
Source: AVOCET 2007
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Construction Water Supply
Water is available on site for construction purposes. Water wells are just north of the Northwest
Area, at the southwest corner of the Project Site (south of Tank Farm Road), at the southernmost
tip of the Project Site (also south of Tank Farm Road), and on the eastern edge of the Project Site
south of Tank Farm Road. As necessary, the contractor would supply pumps, storage tanks, and
stands to fill water trucks for dust control and other construction activities.
One storage tank and fill stand would be located next to the existing water well at the Northwest
Area, and another would be located south of Tank Farm Road, adjacent to the entrance. The
contractor would be responsible for determining the adequacy of water supply and for making
any upgrades to the supply infrastructure. Prior to mobilization, the suitability of the existing
water distribution network for conveying water for construction purposes would be evaluated. If
feasible, fill stations would be located at readily accessible points such as the on-site fire
hydrants. Otherwise fill stations would be supplied by temporary overland pipelines.
Bottled water would be used for potable purposes and would be brought on site and stationed at
work and staging areas as needed. The contractor would also supply sanitary facilities at needed
locations.
Off-site Hauling of Material
It is anticipated that most hydrocarbon-impacted soils would be disposed of at the Nonhazardous
Hydrocarbon Impacted Soil (NHIS) facility at the City of Santa Maria Landfill. Use of NHIS is
consistent with the requirements included in Title 27 of the California Code of Regulations and
has been approved by the California Integrated Waste Management Board (CIWMB) and the
Central Coast Regional Water Quality Control Board (RWQCB). NHIS material includes, but is
not limited to, soils from oil field sumps, tank farms, pipeline leaks, or petroleum product spills.
The Santa Maria Landfill has an NHIS program addressing the types and monitoring of the
NHIS received at the landfill.
The proposed truck route for transporting petroleum-containing soil and demolition debris from
the Project Site is as follows: westbound on Tank Farm Road, then southbound on South Higuera
Street, then westbound on Los Osos Valley Road to the Highway 101 southbound on-ramp.
From southbound Highway 101, trucks would exit at Betteravia Road in Santa Maria, travel east
on Betteravia Road to Philbric Road, then north on Philbric Road to the SML entrance. An
alternate route would involve trucks traveling east on Tank Farm Road, then southbound on
Highway 227, then westbound on Price Canyon Road, then south on Price Street to the
southbound Highway 101 onramp. The route from Highway 101 to SML would be same. The
route would be the same in reverse for inbound trucks. The applicant estimates that 10,500 truck
trips would be necessary to transport the NHIS to the Santa Maria Landfill. Hours of work are
planned to occur between 7 a.m. and 5 p.m. Monday through Friday within the months of April
to October, with peak hauling periods between July and September. Figure 2-13 shows these
truck routes
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Figure 2-13 Proposed Truck Routes
The material would be used at the landfill as cover for closing landfill cells. The materials to be
transported would be tested to ensure it meets the Santa Maria Landfill’s specifications for
NHIS . Any material that does not meet the NHIS specifications will be separated and handled
appropriately. Soil that does not meet the NHIS criteria will be sent to another licensed facility
able to accept hydrocarbon-impacted soil, to either Clean Harbor’s Class I disposal facility in
Buttonwillow, California or the Chemical Waste Management (CWM) Class I disposal facility in
Kettleman City, California. The truck route to Buttonwillow or Kettleman City would involve
accessing Highway 101 as described above (see Figure 2-13). The designated highway route to
CWM Kettleman Hills Landfill would be as follows: Highway 101 northbound, then east on
Highway 46, then northeast on Highway 41 to the landfill entrance. The designated highway
route to the Clean Harbors Buttonwillow Landfill would be as follows: Highway 101
northbound, then east on Highway 46, then south on Highway 33, then east on Lokern Road to
the landfill entrance.
The Applicant estimates that disposal of up to one-third, or 50,000 cubic yards, of the soil at
either of these two locations could occur.
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Site Access
The principal entrance to the Project Site would be relocated to the primary staging area.
Chevron is recommending that the entrance gate be moved back 60 to 100 feet from the road and
that adequate turn lanes be provided into the Project Site. The greater distance from the road
would allow trucks to park at the gate without blocking traffic along Tank Farm Road.
Other access points would be provided as needed but controlled by the contractor. At a
minimum, it would be necessary for the contractor to move vehicles, personnel, equipment, and
materials between the north and south portions of the Project Site across Tank Farm Road. This
would occur at the location shown in Figure 2-12, approximately 750 feet west of the primary
staging area. The existing gate to the south portion of the Project Site is the current access point
and would be maintained for use during remediation. A new, appropriately sized gate would be
installed to provide access to the north portion of the Project Site directly across from the south
gate so that traffic crosses Tank Farm Road in the minimum distance and time. Access to the
Project Site would also be maintained at the Northwest Area, but would not be used as a primary
access to the Project Site.
The internal routes shown in Figure 2-12 are intended to provide the contractor with access to all
potential work and borrow areas across the Project Site with as little impact to sensitive habitat
as possible. The access routes utilize existing dirt tracks. Those shown as solid lines in Figure 2-
12 would be required, while those shown as dashes would only be used if the borrow sources
shown at the end of those routes are developed. It is anticipated that most routes must be able to
accommodate two-way traffic. Existing dirt tracks would be widened, as necessary, to at least 24
feet in the direction that is least likely to affect adjoining sensitive habitat. Management
procedures would be used to minimize impacts from dust and erosion. Where necessary, the
contractor would improve the roadway by grooming the subgrade to provide a reasonably
smooth surface. A geotextile placed over the subgrade would provide separation between the
subgrade and a minimum 6-inch thick course of compacted crushed miscellaneous base or
gravel.
The contractor would also provide traffic control to ensure the safe operation of vehicles and
equipment. One key component would be controlling traffic crossing Tank Farm Road. It is
anticipated that the contractor would at least provide a flagman and signs. It is possible, however,
that in consultation with the appropriate municipal agency, a temporary stop sign or traffic light
may need to be installed at this location.
Access to the borrow areas would be provided on an as-needed basis. Some of the borrow
sources may be used to facilitate other project needs such as mitigating habitat impacts. The use
of these locations, and the associated access routes, would be determined at a later date.
2.2.7.2 Borrow-Area Excavations
It is anticipated that many of the soil materials needed for remediation may be obtained onsite.
The following sections discuss the various proposed borrow sources, the types of materials
available in each, and the estimated quantity of potential borrow material. Figure 2-14 shows the
location of each of the borrow sources, and Table 2-2 summarizes the estimated material
quantities available from each.
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Chevron anticipates that there is ample soil for most of the project requirements. Borrow Areas
1 and #3 are adjacent to large existing wetland complexes. Borrowing from these areas provides
the opportunity to expand those complexes. Redundant borrow sources reduce the likelihood of
importing significant quantities of material from off-site sources.
It is important to note, however, that some borrow materials, especially the tank berms, may
contain asphaltic materials that are inseparably embedded into the soil matrix. Only the plastic
hydrocarbon has been identified as posing a potential hazard or risk, and where these materials
are expressed at the surface or exposed during other excavations, they would be removed.
Conversely, the asphaltic material does not warrant remediation and its potential incorporation
into the common or structural fills is consistent with the findings and recommendations of the
Feasibility Study. Notwithstanding this, remediation efforts would favor borrow materials that
are not impacted by asphaltic material.
There is a possibility that the material at the former quarry site will not meet the RAP’s gravel
specification. This material may have to come from a commercially available gravel source in
San Luis Obispo County or Santa Barbara County. Possible gravel sources include the Rocky
Canyon Quarry in Atascadero, Kaiser Quarry in Santa Margarita, or the Hanson sand and gravel
quarry in Sisquoc near Santa Maria.
Flower Mound
The area referred in Figure 2-2 as the Flower Mound is an area proposed by Chevron to be used
as a borrow site due to its available rock material for backfill of excavation areas. The Flower
Mound area is approximately 17.3 acres in the northwest corner of the Project Site within OU #3,
which is approximately 55.1 acres. It is an outcrop of the basement bedrock complex known as
the Franciscan Formation. Typically referred to as the “Franciscan mélange,” the Franciscan
Formation is comprised of a complex collection of various rock types. Although the Franciscan
Formation found at the Project Site includes localized occurrences of coarse- to fine-grained
clastic sedimentary rocks, it more commonly consists of highly fractured and weathered
metavolcanic rocks and serpentinite. It is these latter types of rock that comprise the Flower
Mound.
The Flower Mound contains approximately 328,250 cubic yards of material that must be blasted
and processed to access. Chevron anticipates that blasting with directed explosive charges will be
needed to break up rock materials within the Flower Mound area. Processing would at least
include crushing, and may include sorting, depending upon what materials are required by the
project.
Material produced from the Flower Mound would be crushed and screened to meet project
materials specifications. It is anticipated that the Flower Mound material would be readily
suitable for use as common or structural fill.
Berms
Numerous berms were erected around the Project Site during its operational life. These were
principally constructed to contain oil spills and to isolate the reservoirs in the event of fire. It is
proposed to use the berms adjacent to Reservoirs 5 and 7 to supply the common fill required for
cap construction.
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Figure 2-14 Proposed Borrow Sites
Source: AVOCET 2007
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Table 2-2 Borrow Site Quantities
Area Gross Area
acres)
Topsoil
cubic yards)
Common
Earth
cubic yards)
Gravel
cubic yards)
Off-Site Cut
cubic yards)
Borrow # 1 8.6 9,000 27,200 0 0
Borrow # 2 8.5 20,700 0 0 0
Borrow # 3 17 19,700 59,250 0 0
Flower Mound 55 0 262,850 65,400 73,700
Reservoir 5 & 7 Berms - 0 71,600 0 0
Total - 49,400 420,900 65,400 73,700
Source: AVOCET 2007
This material may be locally contaminated and, therefore, unsuitable for structural fill. Borrow
activities would be monitored and the materials segregated as necessary for various uses and to
ensure that contaminated material is not used for fill.
Borrow #1
Borrow # 1 is an approximately 8.6-acre site located adjacent to the North Marsh. It includes
approximately 2.3 acres that may have been used as a disposal area for demolition debris from
the 1926 fire. Anecdotal reports suggest that the disposed materials consist mostly of
construction debris, such as concrete and wood. This material would be characterized, removed,
and managed at an appropriately permitted facility. It is estimated that the disposal area contains
a total of approximately 10,325 cubic yards, including debris, assuming an average depth of
approximately 4 feet.
Soil suitable for use as common and structural fill, and possibly as topsoil, could be removed
from the borrow area after removal of the debris. The nominal grading contours for this area
would begin at the existing floor of the wetland area and slope back to the east at approximately
0.5 percent. Side slopes would be no greater than 4:1 (horizontal:vertical). This grading approach
would generate approximately 36,200 cubic yards of common or structural fill.
This borrow source may be used on an as-needed basis. Its main attraction is that after borrowing
the available soil the area can be used to create additional wetland. Complete utilization of the
borrow source and removal of the historical debris would potentially generate 7.84 acres of
additional wetland habitat. This is in excess of the 0.77 acre of wetland that is currently present
within the proposed borrow site.
Borrow # 2
Borrow # 2 is located on the east portion of the Project Site, south of Tank Farm Road. It covers
approximately 8.54 acres but does not include any pre-existing wetlands. This borrow site
should generate topsoil suitable for use in revegetating the caps. It is estimated that 20,700 cubic
yards of topsoil may be recovered from this location. A portion of the topsoil horizon would be
removed for use in remediation. After borrow operations are completed, the borrow site would
be re-graded to support future development. It is estimated that 65,700 cubic yards of topsoil
would be required for remedial construction. Any topsoil deficit would need to be closed by
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manufacturing topsoil from other borrow materials or importing topsoil from off-site sources.
The total volume of import will be limited to the amount of gravel required for remediation.
Borrow # 3
Borrow # 3 is located west of Reservoirs 5 and 6 and would function similarly to Borrow # 1. It
provides a useful source for common fill and structural fill, and possibly topsoil. It also provides
a location that, if utilized, potentially creates additional wetland habitat that can mitigate the
habitat that is unavoidably impacted during remediation.
The proposed area is approximately 17.5 acres in extent, including approximately 6.59 acres of
existing wetland. It is assumed that material would be borrowed from this source starting at the
wetland along the south boundary. The existing grade would be lowered to the elevation in the
southwest corner and then allowed to slope up at approximately 0.5 percent to the north. This
approach would yield approximately 78,950 cubic yards of borrow material.
Gravel Source Contingency
Chevron has requested that the potential use of commercially available gravel for use in
construction of the proposed reservoir caps instead of on-site gravel sources be analyzed as part
of this Project. Approximately 70,000 cubic yards of gravel will be required during the
construction of the two remedial caps. There is a possibility that the material at the former quarry
site will not meet the RAP’s gravel specification. If needed, Chevron would import this material
from a commercially available gravel source in San Luis Obispo County or Santa Barbara
County. Possible gravel sources include the Rocky Canyon Quarry in Atascadero, Kaiser Quarry
in Santa Margarita, or the Hanson Sand and Gravel Quarry in Sisquoc near Santa Maria.
2.2.7.3 Excavation Procedures and Quantities
Some impacted near-surface soils, mostly those affected by petroleum with wildlife entrapment
potential, would be excavated. These selective excavations have been chosen to either improve
the function of a capping system or to mitigate an identified ecological risk. Where performed in
conjunction with construction of a cap, the excavation would remove a limited amount of
material defined by an excavation depth (e.g., 2 feet) or by exposure of some existing feature
e.g., a former reservoir bottom).
Clean-closure areas include the North Marsh and Other Sticky Hydrocarbon Surface Expression
areas of concern, respectively. The clean-closure approach would be limited to pliable
hydrocarbon material. There may be field determinations as to the need for removal of some
hydrocarbon materials, and these determinations would be made with the concurrence of a
regulatory agency representative. A practical field methodology would be prepared.
Field investigations have shown that the isolated pockets of plastic hydrocarbon identified for
removal are the byproducts of the fire or operational spills and appear to be localized to within 3
to 4 feet of the ground surface. In the event that these impacts are determined to extend locally to
depths greater than 5 feet, it is proposed that removal excavations would be limited to a depth of
5 feet bgs.
One objective of the remedial design is to ensure that future open space uses of the Project Site
do not pose an unacceptable risk to potential ecological receptors, which include burrowing
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animals. The applicant proposed limit for excavation is below the burrowing depths of most
animals that are likely to be encountered at the Project Site (DTSC 1996). Further protection can
be provided by using a 0.75-inch gravel for the first 6 inches of backfill to act as a barrier to
burrowing animals, if that is deemed necessary.
Chevron believes that 5 feet of compacted backfill would prevent resurfacing of the plastic
materials. The materials are viscous and generally appear to mobilize only when exposed to the
warming effects of direct sunlight (England Geosystem, Inc. 2001). By removing material from
the near-surface and replacing it with a well-compacted backfill, Chevron indicates that the
likelihood of the material resurfacing is low. Soil used for backfill would be compacted to 90
percent of its relative maximum density as determined by ASTM Method D1557.
Clean materials, those not impacted by plastic hydrocarbon, would be segregated during
excavation, stockpiled locally, and reused as common earth backfill. Common earth may include
solid asphaltic hydrocarbon. Materials impacted by plastic hydrocarbon would be disposed off
site. Impacted soils would be loaded directly onto a truck and hauled off site or temporarily
stockpiled on site at a designated staging area until transported off site for disposal.
The Northwest Area would be used as a staging area to stockpile contaminated soil prior to
loading on trucks for off-site disposal. The Northwest Area would be capped and later
developed. It is estimated that remedial actions could generate up to 157,000 cubic yards of
impacted soil. If truck trips constrain the off-site removal of impacted soil, the stockpile would
be used to accommodate the surge between the volume generated each day during excavation
and the volume that is scheduled for removal. The Northwest Area should provide sufficient
room for this operation. The estimated entire volume of impacted soil generated during
remediation would occupy less than 4 acres if placed in a 25-foot tall pile.
A secondary stockpile area has been identified on the south side of the Project Site, adjacent to
the gate on the existing paved area (see Figure 2-12). It is likely that this area would be used to
store equipment or materials. The paved area is slightly greater than one acre, and the stockpile
would be limited in capacity to approximately 15,000 cubic yards. In operating a stockpile for
impacted soil, Chevron would have to comply with local APCD regulations. This may likely
require covering the stockpile or other means to keep fugitive air emissions within regulatory
limits. Chevron would also be required to control dust and minimize stockpiling during the rainy
season.
2.2.7.4 Site Grading
Table 2-3 shows the grading, cut, and fill from each operational unit. Appendix A shows grading
plans for the following areas:
Northwest Area Cap Grading Plan(OU #1);
Reservoir 3 Grading Plan (OU #4);
Reservoir 4 Cap and Flower Mound Grading Plan (OU #3);
Reservoir 5 Cap Grading Plan (OU #2);
Reservoir 7 Cap Grading Plan (OU #2); and
Borrow Area #2.
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Table 2-3 Area Grading and Excavation Quantities
Grading
Area
acres)
Work
Area
acres)
Estimated
Impacted Soil
cubic yards)
Common Fill
cubic yards)
Structural
Fill
cubic yards )
Gravel
cubic
yards)
Topsoil
cubic
yards)
Geotextile
12oz./
Geomembrane/
Geogrid
acres)
OU #1 –
Northwest Area 6.4 6.4 - - 53,400 - - 6.4/0/0
OU #2 –
Reservoir 5 7.8 10.4 15,300 12,500 - 20,100 12,600 7.8/0/0
OU #2 –
Reservoir 7 6.8 8.0 11,000 24,500 - 39,000 11,000 3.7/0/0
OU #3 and Flower Mound
Borrow Area 52.6 52.6 - - 262,800 - - 7.9/0/0
OU #4 –
North Marsh Area 13.3 15.6 75,300 53,800 - - 21,500 -
OU #4 –
Reservoir 3 6.9 13.3 26,700 5,100 - 10,500 11,100 20.0/6.7/6.7
OU #4 –
Remaining Petroleum
Expressions 5.9 3.6 28,700 19,200 - - 9,500 -
Borrow Area #2 12.1 12.1 - - 57,900 - - -
Total 111.9 122.1 157,000 115,100 374,100 69,600 65,700 45.8/6.7/6.7
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2.2.8 Remediation Schedule, Employee, and Traffic Details
This section estimates manpower and equipment requirements to complete the remediation
activities at the Project Site. These tables are based on working one 10-hour shift per day,
Monday through Friday. Table 2-4 shows the anticipated employees needed to complete the
remediation activities. Refer to Table 2-5 for the anticipated project equipment requirements.
Table 2-4 Employee Requirements for Remediation
Number Job Category
1 Project Manager
1 Construction Manager
1 Foreman
1-2 Safety Officers
6-10 Equipment Operators
10-14 Truck Drivers
4-6 Surveyors/Soils Technicians/Environmental
Monitors
5-10 Laborers
29-45 Total (plus extra truck drivers as needed)
Table 2-5 Equipment Requirements for Remediation
Number Equipment Type
2-3 Bulldozers
2-4 Excavators
2-4 Rubber-tired front end loaders
4-6 10-wheeled dump trucks
1-2 Vacuum truck
1 Universal processor
2-4 Sheep’s foot Compactors (self-propelled)
2 Motor graders
2-4 Flatbed utility truck
1 Trucking services (as necessary)
Truck trips would be generated offsite by the transportation of contaminated and hydrocarbon
impacted soils and demolition materials. Total export is estimated at 157,000 cubic yards, or
approximately 10,500 truck trips. Total import of fill materials is estimated to be 69,600 cubic
yards, and 4,640 truck trips. Daily workers are estimated to generate up to 90 trips per day.
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Estimated peak day trips for the project are summarized in Table 2-6 (ATE 2007). The Chevron
schedule indicates that grading and remediation would take 2.5 years until completion. All
grading and remediation would occur in advance of the development phases of the Proposed
Project.
Table 2-6 Peak Remediation Traffic Levels
Phase/Activity Type of Vehicle Round Trips
Total/Annual
Round Trips Peak
Day
Current Monitoring
Groundwater monitoring Auto 104 2
Bird netting Auto 104 2
Total 208 4
Remediation
Retaining wall steel/concrete Truck 26 2
Reservoir 5 geotextile/gravel Truck 1006 20
Reservoir 7 geotextile/gravel Truck 1951 20
Reservoir 3 geotextile/gravel Truck 528 20
Reservoir 4 geotextile Truck 1 1
Demolition Truck 2775 46
NHIS hauling Truck 10500 40
Import of fill materials Truck 4640 18
Equipment Delivery Truck 31 10
Personnel Auto 23400 90
Total 44858 267
Restoration
Employees Auto 5200 20
Redevelopment Construction
Equipment Delivery Truck 24 10
Materials Delivery Truck 1600 100
Employees Auto 39000 150
Total 40624 260
Long-Term Monitoring
Inspections Auto 16 4
Maintenance Truck 320 8
Total 336 12
Sources: ATE 2007, Padre 2007, Padre 2009, Chevron 2007 & 2008, AVOCET 2007
2.2.9 Long-Term Monitoring Activities
Once the caps and other short-term remedial actions have been implemented, the long-term
monitoring and maintenance phase of Project Site closure would begin. Long-term monitoring is,
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in itself, considered by Chevron a remedial action for various groundwater impacts. Long-term
maintenance, however, is intended to ensure that those actions taken under this plan (e.g.,
excavations, cap construction) continue to meet their remedial objectives. This is important, in
that most of the impacted materials onsite would remain after remediation is complete, especially
in the former reservoirs. Therefore, periodic inspection and, as necessary, maintenance are
necessary components of remediation.
Inspection would primarily cover the engineered caps, habitat restoration and mitigation areas,
and the open space caps and development caps. In general, it is anticipated that inspections
would occur periodically after a given remedial action is completed. The frequency of
inspections is proposed to be quarterly for the first two years after construction and then semi-
annually.
Inspections would, at a minimum, focus on the following:
signs of erosion or burrowing by animals;
recurrence or new surface expressions of plastic hydrocarbon;
successful revegetation;
integrity of fencing and other onsite institutional controls; and
settlement.
Most of these activities would be visual inspections by trained technicians or subject experts
e.g., wetland restorations specialists). Settlement would be measured by properly trained
technicians under the supervision of a surveyor or civil engineer licensed to practice in the state
of California. Settlement measurements would monitor movement in the various caps.
Inspections would look for resurfacing of plastic hydrocarbon expressions at the excavation
locations, especially if material was left in place at depths greater than 5 feet. Inspections would
also include other areas of the Project Site overlying impacted soils and would look for new
surface expressions. In either case, resurfaced material would be removed using the standards
and protocols described in this plan. Further recurrence of a surface expression would prompt
evaluation and a focused remedial action.
The degree to which settlement is considered unacceptable would vary between caps. It is
expected that significant settlement may occur at the Reservoir 3 cap. The geosynthetics will
accommodate up to 2 feet of settlement in the reservoir. The resulting strain in the geosynthetic
is expected to be less than 6 inches. The caps to be built for Reservoirs 5 and 7 would be
somewhat more sensitive to settlement; it could compromise the void space available for
groundwater to occupy. These caps can accept settlements up to 1 foot, measured at the former
reservoir centers before remedial activity would need to be considered.
The development area caps are not expected to experience significant settlement prior to
subsequent construction activities. It is anticipated, however, that any structures built on these
caps would include careful geotechnical engineering that incorporates the limits and constraints
of the caps.
Over time, the caps may require maintenance. It is expected that this would be minor in nature
and would include activities such as repairing drainages and maintaining vegetation. Frequent
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maintenance, however, would be necessary for the storm water management features in the
development areas. These include the surface mulching, cleaning of desilting basins, and
periodic cleaning of the culverts located at the Northwest Area.
More significant repairs would be made as needed, and would be based on observations made
during the periodic inspections. This would include re-grading if low spots develop in caps other
than Reservoir 3.
Land use covenants would be prepared for the various potential subdivisions of the Project Site.
This would include not only potentially developable parcels, but also the open space areas. A
land use covenant is a legal document that would accompany a parcel’s deed. It would be signed
by representatives of Chevron and the lead agencies (e.g., RWQCB), and would be notarized and
recorded with the County Clerk/Recorder. It is intended to ensure that future owners of the
properties understand what mechanisms are in place at the Project Site to protect human health
and the environment, and to identify for future property owners their responsibilities in
maintaining those protections.
The specifics of the land use covenant for the Project Site would vary depending on which parcel
is under consideration. It would, however, identify the allowed land uses and would exclude uses
that might be allowed under current or future land use planning but are inappropriate for the
Project Site. The land use covenant would list the various caps and other containment features
that must be maintained. It would be accompanied by various documents, such as the guidelines
for vapor barriers, Habitat Mitigation Plan, and Soil Management Plan prepared for the Project
Site as part of the Proposed Project. The land use covenant would also restrict the use of
groundwater in areas of impacted soil on the Project Site. Chevron would work with adjacent
landowners to establish covenants regarding soil and groundwater on adjacent properties affected
by historical Project Site activities. A draft of the land use covenant would be prepared by
Chevron for review by the RWQCB and the lead municipality once the Remedial Action Plan
has been approved. The covenant is proposed to be finalized prior to title transfer or transfer of
ownership.
The long-term ownership and management of the property is uncertain at this time, however, it is
expected that the open space portions of the property will be deed-restricted or otherwise
dedicated to open space uses in perpetuity. The City of San Luis Obispo has indicated an interest
in both fee or easement ownership, provided that the site remediation has been accepted as
complete by the jurisdictional agencies and some form of management endowment has been, or
could be, created. Other possibilities are continued Chevron ownership together with a
managing entity, or some form of nonprofit organization ownership.
Monitoring would require a crew of two to four people walking the Project Site to identify
vegetation growth and the status of caps and various remediation projects. A crew of six to eight
people working an average of 10 days per quarter over a period of five years would conduct
periodic maintenance (e.g., weed control, plant replacement).
2.3 Restoration
The restoration phase as proposed by Chevron would restore areas impacted by the remediation,
impacted by the development and restoration of degraded wetlands. Impacts to waters/wetlands
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due to remediation efforts are expected on 26.06 acres; impacts to waters/wetlands due to
development efforts are expected on 1.16 acres; restoration of degraded wetlands is proposed on
an additional 11.33 acres. The proposed restoration of waters/wetlands would occur on an
estimated total of 45.67 acres, representing a 1.7:1 area-to-area metric.
Details on the proposed restoration plan were documented in the report by Padre and WSP titled
Landscape restoration for the Chevron San Luis Obispo Tank Farm: 75% basis of Design
Report” (Padre 2009). The report presents a landscape-level design at the 75% level of
completion for the waters/wetlands, adjacent terrestrial ecosystems (i.e., uplands), and native
special status plant and animal populations impacted by the proposed remediation, site
development, and landscape restoration. It should be noted that resources agencies have not yet
made decisions on requirements for restoration levels. It is expected that this environmental
review will yield the required restoration standards for the Proposed Project. The following
section provides a summary of the proposed design.
The Chevron proposed restoration design is centered on the following major activities:
1. Earthwork, including mass and fine grading, including installation of microtopographic
features (e.g., large wood structures, mounds, depressions, habitat logs),
2. Planting and seeding,
3. Irrigation,
4. Weed control, and
5. Maintenance, monitoring and adaptive management
Design rationale for implementation of each technique is described in the following text.
Restoration construction activities will be initiated and completed during over two to three dry
seasons (May to November).
2.3.1 Earthwork
At the project site, natural landforms and transitions among them are significantly degraded as a
result of historic land uses. These landforms would be further degraded by proposed remediation
efforts. Earthwork has been designed to use both mass and fine grading techniques to re-create
or mimic (where possible), natural features and transitions within the landscape. Specifically,
grading would restore Project Site conditions to natural forms and functioning, targeting the
re)establishment of important hydrologic processes and the partial structure of faunal habitats
e.g., landscape hydrologic connectivity and creation of smooth transitions within and among
wetland classes and adjacent upland habitats). Additionally, mass grading (specifically clearing,
grubbing and stripping) is effective at removing weeds rapidly through elimination of standing
biomass and surficial weed seed banks. Mass grading would also prepare the soil surface as a
planting environment. In addition, fine grading at the Project Site would create habitats for
threatened and endangered plant and animal species.
Grading plans associated with the restoration are shown in Appendix A. Figure 2-15 shows the
proposed final arrangement after grading and planting.
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The new arrangement of Tank Farm Creek would be intended to address the poor hydrologic
function that results from its existing configuration. The East and West forks would be routed
into the North Marsh. The dual round culverts that cross under Tank Farm Road would be
abandoned, and a weir installed in box culverts forcing water to pond in the North Marsh,
thereby reducing the magnitude of the peak flow for a given precipitation event and delaying its
arrival at the site discharge point to the south. Tank Farm Creek would be relocated to follow the
course of the former auxiliary channel (away from the property line), and a low-flow outlet
would be provided so that it releases water in a controlled manner earlier in a storm, further
reducing demand on the limited storage capacity south of Tank Farm Road.
The modified channels pass storms up to the 10-year precipitation event in a riverine manner
with some ponding in the North Marsh and support of depressional and slope wetland features.
Larger storm events engage the increased storage capacity of the entire site. A typical creek
cross section is shown in Figure 2-16.
In the southeastern portion of the site, specifically in two areas adjacent to the San Luis Obispo
Creek, two creek meanders have been historically cut off from the main channel system by levee
construction. However, the fundamental geometry of the meanders is intact. Chevron proposes
to remove the upstream and downstream earthen “plugs” that separate the meanders from the
East Fork San Luis Obispo Creek channel system, and thus re-engage them. To protect civil
structures (e.g., bridge abutments, instrument landing strip structures), grading, slope hardening
with rip-rap, and installation of some log deflection structures would occur. Sheets showing the
proposed grading areas are shown in Appendix A.
There would also be placed large wood and log structures on flood plain surfaces to create
microtopographic variation that includes abrupt gradients in elevation, soil texture and site water
balance. These features of the restored site landscape would allow for restoration of
biogeochemical functioning, high plant diversity, and a variety of faunal habitats. Appendix A
shows drawings which indicate proposed locations for habitat logs and earthen mounds.
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Figure 2-15 Restoration Planting Plan
Source: Padre 2009
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Figure 2-16 Typical Creek Cross Section
After mass and fine grading as discussed, and prior to planting, finish grade soils would be
ripped and lofted to a depth of approximately twelve inches using either a tractor- or dozer-
drawn set of hydraulic gang rippers and a box or gang disc. The goal of the ripping and lofting
operation would be to decrease soil compaction, increase soil aeration porosity, and improve
conditions for planting. Passes for the ripping and lofting would be made at right angles to each
other. No ripping or lofting would occur on soil surfaces intentionally compacted to encourage
ponding of water (e.g., depression bottoms) or amended to encourage colonization of species of
conservation concern.
After ripping and lofting of finish grades, interim sediment and erosion control systems would be
installed on restoration areas. Best management practices (hereafter “BMPs”) and techniques
would be used including installation of rock aprons to protect high energy storm water outfall
locations, degradable geotextile (e.g., coir cloth) covers on high energy or highly erosive slopes
or river meanders, lifts of sterile straw, hydroseeding with native plant mixes and tackifier, coir
rolls and sediment traps, etc. The location of the sediment control features is shown in Appendix
A.
2.3.2 Planting and Seeding
Restoration planting would be conducted to maintain fidelity to native plant community structure
and composition at the site. A native plant nursery would be established to provide planting stock
suited to the restoration site and to better control planting schedules and logistics. Seed collecting
would be conducted on-site, and off-site as necessary, to assist in reestablishment of locally
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adapted native plants. Planting would be conducted in phases that would allow for important,
shade-tolerant species to be installed after initial plantings have been conducted in certain plant
communities. For example, in the palustrine forest II community type, shade-tolerant species
e.g., elk clover [Aralia californica], hedge nettle [Stachys bullata], and western sword fern
Polystichum munitum]) would be planted after the canopies of the tree and shrub layers
Fremont cottonwood, Western sycamore, coffee berry, toyon, and arroyo willow close (or
nearly so). The restoration planting design and plan is provided in Figure 2-15 and Appendix A.
2.3.3 Irrigation
Irrigation systems would primarily be installed at the nursery area to ensure appropriate
irrigation of container plants. Planting of plants would be conducted in the fall to allow for
natural watering of plants from rainfall. Some irrigation systems may be installed in specific
areas to ensure appropriate moisture levels.
2.3.4 Weed Control
Weed control efforts will be adapted as needed using an integrated program that includes initial
clearing, grubbing and stripping, mowing, hand weeding, weed-whacking, and re-planting or
inter-planting additional plants as necessary, and use of herbicides as necessary. Weed control
will be required as part of the construction, monitoring, maintenance, and adaptive management
activities planned for the project.
An integrated weed strategy that has been successful in waters/wetlands restoration project
elsewhere includes seven parts. They are:
Clearing, grubbing, stripping and mass grading to remove weeds and weed propagules;
Installing nursery stock at high planting densities to promote competitive exclusion of weed
species by native plants, rapid establishment of shade, targeted or limited understory growth;
Installing native plant species with high survival potential and rapid growth rates that will
exclude other species;
Hand weeding and weed whacking to remove invasive species prior to their reproduction;
Use of herbicides registered by the EPA for use in waters/wetlands, only if necessary;
Adaptive management techniques such as rest/rotation grazing by livestock and a controlled
burn program; and
Particular species of non-native noxious weedy plant species will be targeted for immediate
removal if or when they are documented on the restoration site.
2.4 Development Options
It is expected that upon completion of the remediation phase, the Project Site would be converted
to new uses consistent with the evolving land use plans for the area. Chevron is working in
concert with the City, the County, and others to define the final use of the Project Site. Two
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plans are being developed concurrently; a City Development plan and a County Development
plan, depending on whether the development area would be annexed by the City or remain as
part of the County (as it currently is). Each of these plans is discussed below.
2.4.1 City Development Plan
At present, the Project Site is within unincorporated San Luis Obispo County. It has been
proposed, however, to annex the Project Site into the City as part of the AASP. Chevron has
proposed a new land use plan that conforms to the revised runway protection zones resulting
from extending Runway 11-29 at the SLOCRA (see Figure 2-4) and also the more detailed
information regarding location of remediation activities and sensitive resources. Remediation has
been tailored to support the proposed land use concept.
The City development scenario envisions the Project Site developed with approximately 803,000
square feet of commercial and industrial floor area with associated parking, landscaping, open
space, bicycle and pedestrian trails, and various site amenities over a 25-year period. The Project
Site would carry the City Land Use designations of Business Park, Services and Manufacturing
includes repair and maintenance services; retailing of vehicles, building materials and plants,
among others; and light manufacturing), Recreation Open Space, and Conservation Open Space.
2.4.1.1 City Plan Overview
Although the Project Site is presently within the unincorporated County, it also lies within the
City’s sphere of influence and the City desires to annex the Project Site in accordance with the
City’s AASP, dated January 2005. The central focus of the City’s AASP is to convert the 332-
acre Project Site (approximately one-third of the Airport Area) and other surrounding areas to
other uses, including limited commercial development (Business Park) and recreational open
space, while enhancing the physical link between the Airport and City areas. The City’s AASP
provides additional guidance and planning for the area surrounding and including the Project
Site; and complements the adjacent Margarita Area Specific Plan, which addresses the area
immediately north of the Project Site.
Figure 2-17 shows the AASP proposed zoning for the site.
The proposed land uses under the City Plan include 27 acres of business park development, 26
acres of services and light manufacturing, 15 acres of recreation, 14 acres of public right-of-way
e.g., streets), and the approximately 250-acre balance as open space (see Figure 2-18). Cattle
grazing is anticipated to continue in open space areas under the City and County proposals.
Figure 2-19 shows the proposed zoning for the site under the City development plan.
The Project Site is beneath the departure pattern for Runway 11-29 of the SLOCRA, which
extended Runway 29 by approximately 500 feet (see Figure 2-4). This expanded the airport
safety zones beyond those originally considered in the City’s AASP. These expanded zones
render approximately 14.6 acres of the City’s AASP proposed building area less suitable for
development. In addition, environmental studies subsequent to the City’s AASP have identified
protected habitat for Vernal Pool Fair y Shrimp (VPFS) in several of the former tank rings north
of the Northwest Area. Consequently, Chevron’s current proposal includes revisions to the
existing City land use plan consistent with these post-AASP developments.
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Figure 2-17 Site Zoning under the City AASP
Source: Chevron 2007 PEP
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Figure 2-18 Proposed Project Development Plan
Source: Chevron 2005
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Figure 2-19 Proposed Project Land Use Designations and Bike Paths
Source: Chevron 2007 PEP
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The proposed land use plan trades approximately 9 acres of developable area in the northwest
portion of the Project Site and on the west edge of the area south of Tank Farm Road for 16 acres
in the northeast portion of the Project Site (see Figure 2-17). Overall, the developable area
relative to the City’s AASP land use plan increases by almost 7 acres but decreases by 16 acres
relative to the existing County General Plan. The proposed swap of land use designations also
overlaps, to a large degree, with the County General Plan. The proposed plan provides more
developable frontage along Santa Fe Road, which is anticipated to see significant traffic when it
eventually connects Tank Farm Road with Prado Road. It also avoids 3.28 acres of protected
VPFS habitat in the northwest corner of the Project Site.
The City development option proposes the following:
Business Park: 27 acres with approximately 433,000 square feet of floor space for business
park land, located at the northeastern portion the Project Site. Access would be from the
proposed extension of Santa Fe Road. Examples of potential uses within the Business Park
areas are offices, architects, medical research, dry cleaning, printing, restaurants,
convenience store, and business support services. It is envisioned that this area would be
developed with a campus-like business park. Included in the 27 acres of Business Park would
be 15,000 square feet of retail space, located on the north-west corner of Santa Fe and Tank
Farm Roads;
Service and Manufacturing: 26 acres with approximately 370,000 square feet for Service and
Manufacturing uses located mostly within the Tank Farm Road Corridor. Access to the
western Service and Manufacturing areas would be from Tank Farm Road. Services and
Manufacturing uses to the east would be accessed from Tank Farm Road, Santa Fe Road, and
a new local road. Permitted uses may include airport-related uses, catering services, day care,
equipment rental, vehicle service, and veterinary clinic.
Open Space: 265 acres designated as open space on both sides of Tank Farm Road. 250 acres
would be used for open space and environmental mitigation. The remaining 15 acres located
immediately west of the 21-acre industrial area would be used as active sports fields.
Public Right-of-Way and Streets: approximately14 acres would be used for streets,
sidewalks, and other frontage improvements, including 6.06 acres dedicated to the widening
of Tank Farm Road. The right-of-way areas would also include bike paths on both sides of
Tank Farm Road and along Santa Fe Road as well as within the proposed development. The
road improvements include ingress and egress improvements into the proposed development,
improve Tank Farm Road to a 100 foot right-of-way, and provide sidewalks, curbs and
gutters.
The City would provide water, sewer, and public services such as police and fire. The City
recently installed a sewer trunk line in Tank Farm Road along the property’s frontage (July
2009). Chevron would extend the water main and utilities to the developable areas. The City
option would require an amendment to the City’s AASP, an amendment of the City’s
General Plan Land Use Policy map, a subdivision of existing parcels (Vesting Tentative
Map), annexation of the Project Site by the City, architectural review, and could include
adoption of a Development Agreement with the City.
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Table 2-7 summarizes the proposed City and County plans.
Table 2-7 Development Plan Summaries
Designation City Plan County Plan
Business Park
27 acres
433,000ft2 Business Park
15,000 ft2 retail
27 acres
433,000ft2 Business Park
15,000 ft2 retail
Service and Manufacturing 26 acres
370,000 ft2 service/manuf.
26 acres
370,000 ft2 service/manuf.
Open Space 265 acres with
15 acres as active sports fields
261 acres with
11 acres as active sports fields
4 acres for WWTP
Right of Way
14 acres with
6.06 acres for Tank Farm Road
widening
14 acres with
6.06 acres for Tank Farm Road
widening
Table 2-8 shows a possible worst case mix of uses for each land use category. These levels of
use would be used to establish traffic and other issue area impacts. Since the tenants have not
yet been established, there is a potential variation on size of each of these uses. However, the
parameters set up in Table 2-8 are anticipated to be within a likely envelope of development and
has been developed based primarily on traffic generation.
Table 2-8 Detailed Development Plan Worst Case Mix
Designation Detailed Use
Business Park Office Park (418,000 ft2)
Retail (15,000 ft2)
Service and Manufacturing
Manufacturing (170,000 ft2)
Industrial Park (170,000 ft2)
Day Care (5,000 ft2)
Vehicle Service (20,000 ft2)
Veterinary Clinic (5,000 ft2)
Although the specifics of the active sports fields has not been determined, based on the area set
aside for active sports fields, the area could be comprised of up to five soccer fields or eight
baseball fields, including parking areas, concessions, maintenance areas, etc. A proposal by
Babe Ruth Baseball has been submitted to the Applicant for development of the recreational area
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into baseball diamonds. The area would be comprised of three baseball fields and amenities
including the following characteristics:
A championship baseball field having 147,500 ft2 area with sports lighting, scoreboard,
built in terrace seating, bleachers;
A baseball field having 104,500 ft2 with sports lighting, scoreboard, bleachers, and
scorekeepers booth;
A flexible use field (Baseball and Softball) having 108,000 ft2 with scoreboard,
bleachers, and scorekeepers booth;
Batting cages totaling 3,500 ft2;
Restrooms, a plaza and a playground totaling 17,000 ft2;
Parking area totaling 45,000 ft2;
Open space for grass areas for team warm up, general use, picnic tables & benches
totaling 236,580 ft2; and
Wetland areas and paths totaling 16,800 ft2.
More details on the baseball proposal are included in Attachment A.
Improvements and modifications would be made to existing roadways in the project area. Also,
new roads would be installed and associated tie-ins to existing roadways infrastructure would
occur. Detailed drawings associated with these portions of the project are shown in Appendix A.
Tank farm road would be reconstructed including the following elements;
Widen Tank Farm Road to 4 lanes
A 14 foot wide median down the middle of the road;
Existing power lines would be placed underground;
A 20 foot wide multi-use pathway/bikeway would be placed on the south side of Tank
farm Road; and
Installation of culverts and improvements to drainage systems.
Santa Fe Road south of Tank farm Road currently is a two-lane road ending at Tank farm Road
with a stop sign. Santa Fe Road south of Tank farm Road would be realigned and tie in to Tank
Farm Road with the following elements:
The short segment of Santa Fe Road that is to be re-aligned would be 4 lanes;
An arched culvert would be constructed over San Luis Obispo Creek;
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A multiuse bike path/sidewalk would be constructed on both sides of the Santa Fe
realignment.
New roads would be constructed north of Tank farm Road, including:
A ¼ mile long extension of Santa Fe Road continuing north of Tank farm Road as a two
lane road with a 14 foot landscaped median;
Construction of the two lane “A” Road north of Tank Farm Road off of Santa Fe Road
approximately 300 feet long); and
Construction of a 1/3 mile long two lane “B” Road intersecting with Tank Farm Road
west of the Santa Fe intersection curving towards the east to intersect with the new Santa
Fe Road.
2.4.1.2 City Option Construction Requirements
Construction would take place in five development phases, with each phase lasting
approximately 5 years. Development phases would begin once the remediation project is
completed. Figure 2-20 shows the location of the phases.
Build-out under the Proposed Project would involve grading and construction of commercial,
industrial, retail and recreational structures throughout the Project Site. The most intense activity
would be generated during the initial phases of Project Site preparation when large areas of soil
would be disturbed and many large construction vehicles would be operating.
Site grading would be completed during the remediation phase and only minimal additional site
grading would need to be conducted with each phase of development. An estimated 1,600 truck
trips for each phase would be required to deliver materials and equipment to the Project Site. A
total of 150 construction workers would be associated with each phase. Table 2-9 summarizes
the necessary construction equipment.
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Figure 2-20 City Development Option Phasing
Source: Chevron 2005
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Table 2-9 Development Construction Equipment (per phase)
Number Equipment
3 Scrapers
2 Dozers
2 Loader
1 Excavator
1 Grader
1 Water truck
3 Pavers
2 Rollers
3 Forklifts
3 Backhoes
1 Crane
1 Generator set
1 Welder
2.4.1.3 City Development Option Operations
Once the City option is completely built out, there would be an increase in traffic associated with
the development and an increase in water use. Traffic levels are estimated based on the Institute
of Traffic Engineers Trip Generation Manual, 7th Edition. Water use rates are based on water use
factors provided by the City of San Luis Obispo Utilities Department. Table 2-10 shows the
estimated water use and the traffic generated at the end of the project build-out in an estimated
25 years.
Table 2-10 City Option Build-Out Water Use and Traffic
Type
Floor Area
square feet)
Water Use
Factor
per 1,000
square feet)
Water Use
acre feet
per year)
Weekday
Trip
Generation
per 1,000
square feet)
Weekend
Trip
Generation
per 1,000
square feet)
Weekday
Average
Daily
Trips
Weekend
Average
Daily
Trips
Manufacturing 180,000 0.22 40 3.9 1.5 702 270
Industrial 180,000 0.22 40 7.0 2.5 1,260 450
Retail Sales 15,000 0.88 13 167.6 215.4 2,514 3,231
Business Park 428,000 0.06 26 11.4 1.6 4,879 685
Recreation 15 acres - - 1.6 20 24 300
Total 803,000 - 118 - - 9,379 4,936
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The City would provide water, sewer, and public services such as police and fire. The City has
recently installed a sewer trunk line along the Project Site’s frontage. Chevron would extend the
water main and utilities to the developable areas.
Table 2-11 shows the traffic levels generated by each phase of the Project. The traffic levels are
based on the land uses associated with each phase and corresponding trip generation rates.
Table 2-11 City Option Traffic Generation by Phase
Phase Weekday Average Daily Trips Weekend Average Daily Trips
1 3,840 3,820
2 1,462 316
3 1,182 209
4 816 300
5 2,078 292
2.4.2 County Development Option
The only differences between the City and County plans are that the City plan includes more
rapid (phase 1) potential development in the eastern end of the Project Site, north of Tank Farm
Road and the need in the County plan to use approximately 4 acres of land designated as Open
Space to construct a new wastewater treatment facility to serve the County development
scenario, and to secure a source of water for the site since City water is not available to users
outside City limits. Figure 2-21 shows the existing County land use designations and Figure 2-
19 shows the Proposed Project’s land use designations.
Chevron’s goal under the County plan would be to develop a portion of the Project Site with an
approximate 803,000 square feet (floor area) business park with associated parking, landscaping,
open space, bicycle and pedestrian trails, and Project Site amenities (the same amount as the City
Plan). This business park would be integrated with the natural resources, enhanced wetlands, and
open space areas. Developments would be executed in five phases over a period of
approximately 20 to 25 years with each phase developing approximately 160,000 square feet of
leasable floor area and taking approximately four to five years to build out.
The County development scenario would carry land use designations of Commercial Services,
Industrial, and Recreational. The County development option transfers the development potential
of the Commercial Services designated land (north of the existing Chevron facilities) to the
eastern portion of the Project Site.
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Figure 2-21 Existing County Land Use Designations
Source: Chevron 2007
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2.4.2.1 County Plan Overview
The County General Plan envisions future development on portions of the Project Site. Possible
development areas under the County General Plan are situated on the east and west ends of the
northern portion of the Project Site, north of Tank Farm Road (see Figures 2-18 and 2-19).
It is anticipated that cattle grazing may continue in open space areas of the Project Site. Cattle
effectively control invasive weeds and limit the fuel available to a potential fire. It is expected
that cattle grazing would be limited to grassland areas and excluded from upland and wetland
restoration areas. Specific requirements for continued cattle grazing would be coordinated with
the CDFG, the RWQCB, and the U.S. Fish and Wildlife Service.
The County development option includes the following:
27 acres with approximately 433,000 square feet of floor space for commercial services,
including limited retail uses;
26 acres with approximately 370,000 square feet for industrial uses;
261 acres of open space and recreational use, with 250 acres used for open space and
environmental mitigation and 11 acres for sports fields;
4 acres for a wastewater treatment facility (WWTF), in the south of the area designated as
recreation in the City option along Tank Farm Road (see Figure 2-19), and onsite wells and
the onsite WWTF would provide water and sewer;
14 acres for streets, sidewalks, bike lanes and other frontage improvements. Bike lanes
would be the same as shown in the City plan; and,
Cal Fire would provide fire protection services, the County Sheriff would provide police
services, and existing area service providers would provide utilities.
The County option would require an amendment to the AASP by the City, an amendment of the
County General Plan, a subdivision of existing parcels, a Conditional Use Permit, and
environmental review (see Table 2-7). The road improvements include ingress and egress
improvements into the proposed development, improve Tank Farm Road to a 100-foot right-of-
way, and provide sidewalks, curbs, and gutters.
Although the specifics of the active sports fields have not been determined, based on the area set
aside for active sports fields, it could be comprised of up to four soccer fields or six baseball
fields, including parking areas, concessions, and maintenance areas. The Babe Ruth baseball
proposal, developed as part of the City plan, would most likely be scaled back for the County
option to fit into the smaller space.
2.4.2.2 County Option Construction Requirements
Project Site construction would require the same level of effort as the City option. Phasing would
be similar to the City option except that a small section of the eastern area would be developed in
phase 2, rather than phase 1 under the City option. Figure 2-22 shows the County plan phases.
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Build-out under the Proposed Project would involve grading and construction of commercial,
industrial, retail and recreational structures throughout the Project Site. The most intense activity
would be generated during the initial phases of site preparation when large areas of soil would be
disturbed and many large construction vehicles would be operating.
Chevron estimates that construction of each phase would take five years. Development phases
would begin once the remediation project is completed. Site grading would be achieved during
the remediation phase and only minimal site grading would need to be conducted with each
phase construction. An estimated 1,600 truck trips for each phase would be required to deliver
materials and equipment to the Project Site. A total of 150 construction workers would be
associated with each phase. Table 2-9 offers a summary of necessary construction equipment.
2.4.2.3 County Development Option Operations
Operations would be similar to the City option, with some additional traffic due to the WWTF
but less traffic because of the smaller area dedicated to recreational facilities. Table 2-12
summarizes the traffic and water requirements associated with build-out under the County
option.
Table 2-12 County Plan Build-Out Water Use and Traffic
Type
Floor Area
square
feet)
Water
Use
Factor
per 1,000
square
feet)
Water
Use
acre
feet per
year)
Weekday
Trip
Generation
per 1,000
square feet)
Weekend
Trip
Generation
per 1,000
square feet)
Weekday
Average
Daily
Trips
Weeken
d
Average
Daily
Trips
Manufacturing 180,000 0.22 40 3.9 1.5 702 270
Industrial 180,000 0.22 40 7.0 2.5 1,260 450
Retail Sales 15,000 0.88 13 167.6 215.4 2,514 3,231
Business Park 428,000 0.06 26 11.4 1.6 4,879 685
Recreation 11 acres - - 1.6 20 17 220
WWTF 4 acres - - 6.8 6.8 27 27
Total 803,000 - 118 - - 9,355 4,636
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Figure 2-22 County Development Option Phasing
Source: Chevron 2005
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Table 2-13 shows the traffic levels generated by each phase of the Project. The traffic levels are
based on the land uses associated with each phase and corresponding trip generation rates. Note
that retail would be shifted to phase 2, rather than phase 1 in the City option.
Table 2-13 County Option Traffic Generation by Phase
Phase Weekday Average Daily Trips Weekend Average Daily Trips
1 1,347 536
2 3,976 3,547
3 1,182 209
4 816 300
5 2,078 292
2.5 Project Permitting Requirements
2.5.1 City Project
2.5.1.1 Specific Plan Amendment
The plan area is located within the City’s AASP, which has been identified for future annexation
by the City. In October 2004, the City adopted the AASP and associated Final Environmental
Impact Report. The City’s AASP establishes the framework for developing these properties and
contains goals, policies, and standards for land uses, circulation, public service and facilities, and
utilities.
Adoption of the Proposed Project will require concurrent or subsequent amendment of the City’s
AASP for which the City would act as a Lead Agency. The proposed land use changes trade
acreage on the west side, considered inappropriate for development due to wetlands and sensitive
habitat, for additional acreage on the east that would better utilize the infrastructure
accompanying extension of Santa Fe Road and widening of Tank Farm Road.
The existing City’s AASP Land Use plan designates 51 acres for Services and Manufacturing, 3
acres for Business Park, 278 acres in Open Space, and the remaining acreage used for streets or
public right-of-way. Business Park is primarily for research and development, light
manufacturing, and business services that include processing, production and airport-related
services. Areas designated Service and Manufacturing are generally for storage, transportation,
and wholesaling type uses, as well as certain retail sales and business services that may be less
appropriate in other commercial designations. Open Space designations are intended to protect
undeveloped or minimally developed land for preservation of natural resources and public safety.
The Project proposes amending the City’s AASP Land Use Plan to designate 26 acres for
Services and Manufacturing, 27 acres for Business Park, 15 acres for Recreation, and 250 acres
for Open Space with the remaining acreage used for public right-of-way. Table 2-14 compares
existing and proposed land uses.
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Table 2-14 San Luis Obispo City Development Option Comparison of Existing AASP and
Proposed Land Use and Acres
Land Use Designation
Land Area
Existing Acres % Proposed Acres %
Business Park 3 1 27 8
Service and Manufacturing 51 16 26 8
Recreation 0 0 15 5
Open Space 279 83 250 75
Streets, Right-of-Way n/a n/a 14 4
Total 332 100 332 100
Other Specific Plan amendments include:
Removing the Service and Manufacturing designation on approximately 8.6 acres in the
northwest corner that is constrained by wetlands and VPFS habitat, as well as airport safety
concerns, and relocating this development potential to a less environmentally sensitive area
near the Santa Fe Road extension and Prado Road;
Eliminating or relocating the collector street (known as the Unocal Collector) along the
western and northern edges of the Project Site to avoid the environmentally sensitive
Northwest Area, which would also include removing underlying planned utilities and
realigning the sewer trunk line located within the collector street’s right-of-way;
Providing an additional driveway connection to Tank Farm Road;
Revisions to appropriate text, tables, and graphics to reflect land use and circulation changes,
including:
Land Use Designations amended to Proposed Plan Area Land Use;
Plan Area Zoning amended to Proposed Plan Area Zoning;
Primary Circulation System and Functional Classifications within Specific Plan Area and
Surrounding Community amended to Proposed Primary Circulation System and
Functional Classifications;
Bicycle Plan amendment; and
Modify southern side of Tank Farm Road street section to remove sidewalk and Class I
path and include a 12-inch wide Class I multi-use path.
2.5.1.2 General Plan Amendment
Approval of the Specific Plan amendments would require an amendment of the City’s General
Plan Land Use Policy map to maintain consistency between the two documents. The resulting
General Plan Amendment would be processed by the City subsequent to Project approval.
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2.5.1.3 City Vesting Tentative Tract Map (Tract No. 2981)
According to the available title information, the Project Site contains 12 certificate parcels and
one parcel created with Parcel Map 03-287. This component of the Project involves subdividing
the Project Site into 19 lots: 16 industrial and commercial lots, 1 lot for recreational faculties,
and 2 open space lots. The proposed lots would range from 4.12 to 178.4 acres (see Figure 2-23).
Vehicular access would be from Tank Farm Road, Santa Fe Road, and internal public streets,
which would be developed consistent with County and City standards and the City’s AASP. Four
30-foot wide shared access easements provide direct access to the industrial lots and to minimize
the number of driveways on Santa Fe Road, Tank Farm Road, and the internal streets.
Pedestrian access would be via public sidewalks and recreational trails.
All utilities would be designed and installed in accordance with City standards. The City would
provide water, recycled water, sewer, police, and fire services. Drainage would be directed to the
open space wetlands and an onsite detention basin south of Tank Farm Road.
2.5.1.4 Pre-Zoning and Annexation
In the unincorporated area of the County, the Project Site is outside of the city limits but within
the City’s Sphere of Influence boundary. Chevron is proposing to annex approximately 333 acres
to the City. With annexation, the City would provide water, recycled water, sewer, and public
services such as police and fire to developed areas. According to City staff, the City has recently
installed (July 2009) a sewer trunk line along the Project Site’s frontage. Chevron would be
required to extend the water main and utilities to the developable areas.
2.5.1.5 Other City Permits (Grading)
Grading for remediation and habitat restoration including Tank Farm and Santa Fe Roads, public
sidewalks, trails, and street trees would be permitted in conjunction with approved construction
plans. Separate grading permits would be needed for the development phases of the Proposed
Project. In addition, entitlements will be necessary from the Architectural Review Commission
for public improvements, subsequent development phases and/or individual proposed buildings.
2.5.1.6 Development Agreement
Chevron is requesting the City negotiate a mutually acceptable pre-annexation agreement and
ultimately a Development Agreement (DA). Adoption of a DA provides long-term financial
certainty to both the City and Chevron. The DA would address phasing construction and costs of
backbone infrastructure, extending the life of the Vesting Tentative Tract Map up to 25 years,
and maintaining certain planning and environmental fees for the life of the agreement. Chevron’s
goal is to have an executed DA prior to or concurrent with annexation of the Project Site to the
City.
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Figure 2-23 Tentative City Tract Map
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2.5.2 County Project
2.5.2.1 General Plan Amendment/Zone Change
The County’s General Plan designates the Project Site Industrial on approximately 47.6 acres,
Commercial Services on approximately 18.6 acres, Recreation on approximately 251 acres, and
the remaining 14 acres are designated Agriculture. The Project proposes amending the County
General Plan, including the San Luis Obispo Area Plan, to designate approximately 27 acres to
Commercial Services, approximately 26 acres to Industrial, 265 acres for Open Space, and the
remaining 14 acres used for streets. The Project would remove the Industrial designation on 23
acres located in the northwest corner and place it on the east side of the Project Site along Tank
Farm and Santa Fe Roads. Development is proposed to be moved from the northwest corner of
the Project Site to avoid sensitive habitat. Table 2-15 compares existing and proposed land uses.
Table 2-15 San Luis Obispo County General Plan Amendment/Zone Change Comparison of
Existing and Proposed Land Use and Acres
Land Use Designation
Land Area
Existing Acres % Proposed Acres %
Commercial Services 19 6 27 8
Industrial 48 14 26 8
Recreation 251 76 265 80
Agriculture 14 4 0 0
Streets, Right of Way, etc. n/a n/a 14 4
Total 332 100 332 100
2.5.2.2 County Vesting Tentative Tract Map (Tract No. 2988).
According to available title information, the Project Site contains 12 parcels with certifications of
compliance and 2 larger parcels created with the recording of Parcel Map 03-287. Tract No.
2988 proposes to subdivide the Project Site into 16 lots consisting of 13 industrial and
commercial lots, 1 lot for recreation and wastewater facilities, and 2 open space lots. The
proposed lots would range in size from 4.12 to 178.4 acres (see Figure 2-24).
Vehicular access would be from Tank Farm Road, Santa Fe Road, and internal public streets.
Tank Farm Road, Santa Fe Road and internal public streets would be developed consistent with
County standards. Four 30-foot wide shared access easements have been provided for direct
access to the industrial lots and to minimize the number of driveways on Santa Fe Road, Tank
Farm Road, and the internal streets. Pedestrian access would be via public sidewalks and
recreational trails.
Chevron has constructed two production wells on-site and has additional rights to a third
production well located on the parcel west of the former operations area of the Project Site.
Collectively they are of sufficient capacity to supply over 150 gallons per minute of water on a
sustained yield basis. All utilities would be designed and installed in accordance with County
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standards. Water would be provided by individual or shared wells. Four acres have been set aside
for a WWTF that would accommodate approximately 81,000 gallons per day.
2.5.2.3 Conditional Use Permit (Grading)
A Conditional Use Permit would be needed to allow grading for remediation and habitat
restoration, including Santa Fe Road and interior streets as well as rough grading of building lots.
A separate permit may be needed for the subsequent development phases under the Proposed
Project.
2.5.3 Other Potential Permits
Chevron is seeking approval of the Remedial Action Plan and authorizations under the Clean
Water Act and Porter-Cologne Water Quality Control Act from the RWQCB. The remediation
and restoration efforts will also require permits and authorizations from the U.S. Army Corps of
Engineers, Los Angeles District; California Department of Fish and Game; SLO County
Environmental Health Division; SLO County Public Works Department; and the San Luis
Obispo County Air Pollution Control District (APCD). Please see Table 2-16 for a listing of the
anticipated project approvals and permits required for the Proposed Project for state, federal and
local agencies.
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Figure 2-24 Tentative County Tract Map
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Table 2-16 Anticipated Federal, State and Local Permits
Agency Permit Regulated Activity Authority
Federal Agencies
U.S. Department of
Defense, Army Corps
of Engineers
Section 404 of the
Clean Water Act
Permit
Discharge of dredged or fill
material into waters/wetlands of
the U.S. during construction
Section 404 Clean Water
Act
U.S. Fish and Wildlife
Service (USFWS)
Section 7
Consultation
Endangered Species
Act) through
consultation with the
USACE
Threatened and Endangered
Species Biological Opinion,
Section 404 Permit.
16 USCA 1513
50CFR Section 17
Advisory Council on
Historic Preservation
Section 106 of the
National Historic
Preservation Act
NHPA) Review
through USACE
process) (possible)
Project activities that will affect
register eligible prehistoric or
historic resources subject to
federal protection requirements.
Review by the ACHP would
only be needed in the project
affects registered eligible
prehistoric or historic
resources subject to federal
protection requirements.
State Agencies
CA Department of
Fish and Game
Compliance with CA
Endangered Species
Act
Species disturbance through
remediation process.
Sections 1601-1607 of the
Fish and Game CodeStreamAlteration
Agreement (1603)
Alteration of the natural state of
any stream.
Approval of RAP Enforcement of Oil Pollution Act
Regional Water
Quality Control Board
RWQCB)
Approval of RAP Remedial Action Plan activities Porter-Cologne
Section 401 Water
Quality Certification
Discharge of fill that may affect
surface and groundwater quality.
Clean Water Act, Porter-
Cologne, Water Quality Act
NPDES Waste
Discharge Permits
possible)
Discharge of treated groundwater
or surface water generated during
construction (if needed)
Clean Water Act, Porter-
Cologne, Water Quality Act
State Office of Historic
Preservation
State Level Review
of Section 106
Compliance
possible)
Project activities that will affect
register eligible prehistoric or
historic resources subject to
federal protection requirements.
Review by the SOHP would
only be needed in the project
affects registered eligible
prehistoric or historic
resources subject to federal
protection requirements.
Local Agencies
SLO County Planning
and Building
Development
Permit, Grading
Permit
Land use, grading, drainage, and
environmental
impacts
Title 22 County Code
CEQA
SLO County
Public Works Dept.
Encroachment
Permit
Any work within public right-of-
ways (if needed). County Code
SLO County
Environmental Health
Division
Well Construction/
Destruction Permits,
CUPA
Approval and inspection of
monitoring well and water supply
well destruction. Approval and
inspection of new monitoring well
construction. Review and
California Water
Code, Title 22
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Agency Permit Regulated Activity Authority
enforcement of hazardous
materials management plans.
SLO County Air
Pollution Control
Dist. (APCD)
Authority to
Construct/Permit
to Operate
Emissions associated with
construction and operations may
require permits.
Clean Air Act
City of San Luis
Obispo
Annexation
approval,
Tentative Tract Map
General Plan/Specific Plan
Amendment Annexation of areas
to be developed into city Approval
of tentative tract map
City Code,
Subdivision Map Act
Acceptance of
Offer to Dedicate
Road Right-of-way
New roadways and roadway
improvements
associated with new development
City Code
Local Agency
Formation
Commission
LAFCO)
Annexation approval Annexation of re-development
areas into City.
Cortese-Knox-
Hertzberg Act of
2000, LAFCO
policies
SLO Airport Land Use
Commission Consistency review Development within the Airport
Land Use Plan area. Airport Land Use Plan
2.0 Project Description
Chevron Tank Farm Project EIR 2-78 May 2010
Administrative Draft
References
The Airport Land Use Commission for San Luis Obispo County. 2005. Airport Land Use Plan
for the San Luis Obispo Regional Airport. San Luis Obispo, CA: The Airport Land Use
Commission for San Luis Obispo County; May 18, 2005.
Associated Transportation Engineers (ATE). 2007. Chevron San Luis Obispo Traffic and
Circulation Study. November 9, 2007.
AVOCET. 2007. Remedial Action Plan. December 18, 2007.
AVOCET. 2007. Feasibility Study, Former San Luis Obispo Tank Farm. March 15, 2007.
BBL. 2005. Risk Management Summary. December 12, 2005.
Chevron. 2005. Presentation on Project as Part of Application.
Chevron. 2007. Final Project Execution Plan for the Chevron San Luis Obispo Tank Farm
Restoration and Re-development Project. San Luis Obispo, CA: December 20, 2007.
Chevron. 2008. Restoration and Redevelopment Project Application.
Department of Toxic Substances Control (DTSC). 1996. Guidance for Ecological Risk
Assessment at Hazardous Waste Sites and Permitted Facilities Part A: Overview. Draft.
Sacramento, CA: Office of Scientific Affairs, California EPA; 1996.
England Geosystem, Inc. 2001. Supplemental Site Characterization. October 15, 2001.
England, Shahin & Associates. 1994. Supplemental Ground Water Investigation Unocal Tank
Farm Facility. May 11, 1994.
McDaniel Lambert, Inc. 2004. Human Health Risk Assessment for the Unocal San Luis Obispo
Tank Farm. Version 2.0. San Luis Obispo, CA. May 25, 2004.
Padre. 2007. Project Execution Plan for the Chevron San Luis Obispo Tank Farm Restoration
And Re-Development Project. San Luis Obispo, CA: December 20, 2007.
Padre [letter]. July 17, 2009. Chevron. Information Request.
Remediation Technology Panel (RTP). 2006. Assessment of Off-Site Migration and On-Site
Surface Expressions of Hydrocarbons at the San Luis Obispo Tank Farm Site. May 9, 2006.