PROJECT DESCRIPTION AND LOCATION
Pursuant to California Public Utilities Code Section 1001, the CPUC General Order (GO) 131-D and
the CPUC's Rules of Practice and Procedure, San Diego Gas & Electric Company (SDG&E)
submitted an Application for a certificate of public convenience and necessity (CPCN) for the
proposed Valley-Rainbow 500 kV Interconnect Project (Application No. 01-03-036, filed on March
23, 2001). The Valley-Rainbow 500 kV Interconnect (Project) is proposed to provide an
interconnection between SDG&E's existing 230-kilovolt (kV) transmission system at the proposed
Rainbow Substation on Rainbow Heights Road near the unincorporated community of Rainbow in
San Diego County and Southern California Edison's (SCE) existing 500kV transmission system at
the Valley Substation on Menifee Road in the unincorporated community of Romoland in Riverside
County. The Project Area is in northern San Diego County and western Riverside County (Figure
1).
Figure 1 Project Area
The major elements of the Project are described below and illustrated on Figure 1:
500kV Transmission Line - A new single-circuit 500kV transmission line, rated at
approximately 1,000 megawatts (MW), would interconnect the new SDG&E Rainbow Substation
with SCE's existing Valley Substation. The right of way would be 170 feet wide (typical).
New Rainbow Substation - A new SDG&E 500/230/69kV substation would be located in
northern San Diego County to interconnect the new 500kV transmission line with SDG&E's
existing 230kV and 69kV transmission systems.
Valley Substation Modifications - SCE's existing Valley Substation would be modified to
accommodate the new 500kV transmission line from the Rainbow Substation. All proposed
modifications would occur on existing utility-owned land within the existing facility
boundaries.
Talega - Escondido 230kV Line Upgrade - The 230kV line was originally licensed and
constructed using double-circuit structures with only one circuit installed. Necessary
transmission upgrades to support the Project import capability would include installing the
second 230kV circuit on the existing transmission structures and modifying the existing
substations at Talega and Escondido.
Rebuild of 69kV Transmission Line - A 7.7-mile section of the existing 69kV transmission
circuit, currently installed on one side of the existing double-circuit Talega -Escondido
230kV transmission line structures and interconnecting SDG&E's existing Pala and Lilac
substations, would be rebuilt on new 69kV structures. The 7.7-mile line, supported on wood
and steel pole structures, would be constructed adjacent to the existing 230kV line along this
section to allow installation of the 69kV circuit. The new section of the 69kV circuit would
be constructed within the existing 300-foot-wide Talega - Escondido right of way.
System Voltage Support - A 230kV Static Synchronous Compensator (STATCOM) would be
added at the existing Mission Substation. Shunt capacitors would be added at Miguel and
Sycamore Canyon substations (230kV). The STATCOM would provide dynamic voltage
support, and the shunt capacitors would provide continuous voltage support. Both
continuous and dynamic voltage support would be required to allow the increased power
import levels provided by the Project. The STATCOM and shunt capacitors would be
installed at existing substations owned by SDG&E.
CONSTRUCTION SCHEDULE
SDG&E's general construction schedule for the proposed Project anticipates start of construction
in 2002 with completion and operation by 2004.
PROJECT PURPOSE, OBJECTIVES AND NEED
The San Diego County and Southern Orange County regional economies have expanded rapidly and
are placing increased demands on that area's transmission system. The ability of the existing
transmission system to reliably meet near term requirements is uncertain without the addition of
significant regional transmission or generation. The existing transmission system also limits the
ability of new generation within the San Diego County region and to the southwest from being useful
in mitigation of current supply problems within California. The proposed Project will provide the
transmission capacity necessary to reliably meet regional loads should regional internal generating
capacity be insufficient to meet regional demand and will also provide necessary export capability
to the north for excess local generation, thus helping resolve the State's energy problems.
In addition to the above short-term benefits, long range transmission plans under development by
the California Independent Systems Operator (CAISO) for the Southern California region indicate
a potential need for development of additional transmission capacity into the San Diego region from
the Southwest. In order for this new capacity to be useful in meeting the overall needs of the State,
it will be necessary to increase current transmission transfer capability from the San Diego region
to the remainder of the state. The proposed Project would therefore provide a critical element in
meeting the overall needs of the State.
ENVIRONMENTAL EFFECTS
Based on the Initial Study/Environmental Checklist (see attached), review of documents submitted
by SDG&E and other parties to the CPUC's CPCN proceeding, the CPUC and BLM have
determined that the proposed Project may have a number of potentially significant environmental
effects. The CPUC and BLM have determined that an EIR/EIS be prepared to fully analyze the
existing environmental setting, the potential impacts resulting from Project implementation, and
potential mitigation measures, if necessary, in the following areas: Biological Resources, Cultural
Resources, Land Use, Visual Quality, Public Health, Safety and Nuisance, Traffic, Noise, Air
Quality, and Hydrology/Water Quality.
The following is a brief description of the environmental effects to be addressed in the EIR/EIS:
Construction and operation of the proposed Project could result in impacts to plant
and animal life including but not limited to endangered, threatened, or rare species
and/or their habitats.
A number of cultural resources sites are known to exist in the Project area, and
therefore, Project construction could impact areas with archaeological and historical
resources, as well as sites with Native American values.
The EIR/EIS will address any instances of potential disruption of existing as well as
planned land uses including residential, business, recreational uses and agriculture,
as well as impacts to adopted environmental plans or policies (e.g., biological
mitigation programs).
Short-term emissions of pollutants generated by Project construction would
contribute to violations of state or federal air quality standards.
Construction and operational activities would increase noise levels for adjoining
areas.
Construction and/or operation-related traffic for the proposed Project would not
create a substantial impact on traffic volumes. However, construction may
temporarily affect traffic patterns and result in temporary traffic hazards. Therefore,
the EIR/EIS will specifically address impacts to the following:
Construction of the Project may result in substantial erosion, affect drainage patterns,
surface runoff rates and water quality.
The EIR/EIS will address relevant concerns of the public with respect to health,
safety and nuisance, focusing in three areas: electric magnetic fields (EMF), the
safety of high voltage electric facilities, and radio, televison, or electric interference.
The proposed 500 kV Interconnect transmission line as well as the proposed new
SDG&E 500/230/69 kV substation to be located in northern San Diego County
would affect the character and views in the Project study area.
MANDATORY DISCUSSION
In addition to the aforementioned issues, the following areas will be addressed in the EIR/EIS:
Growth Inducement, Significant Irreversible Changes, Cumulative Impacts and Alternatives.
The alternatives discussion will describe the process employed to derive alternatives that are capable
of meeting the stated Project's purpose and need and that are technically, economically and
environmentally feasible. The alignments and alternatives originally studied by SDG&E, as well as
those identified during review of SDG&E's application and as requested during public scoping will
be discussed. Alternatives identified for inclusion into the EIR/EIS are listed below. The evaluation
of other alternatives for inclusion in the EIR/EIS will consider their ability to achieve Project
objectives, technical and economic feasibility, compatibility with public concerns, and ability to
reduce identified significant environmental impacts.
The "No Project" Alternative will be analyzed as required.
SDG&E's Route E. As a possible alternative to SDG&E's proposed Valley to
Rainbow 500 kV Interconnect route, the EIR/EIS will evaluate SDG&E's Route E.
This route differs from the proposed route only on the southern seven to nine miles
as it would travel east of the proposed Rainbow Substation south of the southern
boundary of the Pechanga Indian Reservation. The route would turn north along the
eastern boundary of the Pechanga Indian Reservation, which is also the western
boundary of the Agua Tibia Wilderness and the Cleveland National Forest. The
route would then pass to the west side of the Agua Tibia Wilderness Study Area,
which is managed by the BLM for possible inclusion into the National Wilderness
System. The route would continue north and turn to the northeast to cross Highway
79 before turning north across undeveloped lands where it would join the SDG&E's
proposed route.
Pala Substation Site. As an alternative to the proposed Rainbow Substation site, the
Pala Substation site north of Highway 76 on the San Luis Rey River, just west of the
Pala Indian Reservation will be evaluated in the EIR. An additional 4.4 miles of
500kV transmission line within an existing 300-foot wide right of way would be
required if the Pala Substation site were to be selected over the Rainbow Substation
site. The site is an existing 160-acre parcel, most of which is currently being used
as a citrus and avocado orchard.