Welcome to the California Public Utilities Commission (CPUC) website for the environmental review of the Tehachapi Renewable Transmission Project (TRTP) in Kern, Los Angeles, and San Bernardino Counties. Southern California Edison (SCE) submitted an application for a Certificate of Public Convenience and Necessity (CPCN) for this project to the CPUC on June 29, 2007. SCE also submitted an application for a Special Use authorization to the USDA Forest Service. The project has been reviewed under both the California Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA). This site provides access to public documents and information relevant to the CEQA and NEPA review processes, as well as information regarding construction of the Project.

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Project Location Maps
Addendum to Final EIR (7.7MB)
Draft SEIR/SEIS
Final SEIR/SEIS
Final EIR
Final EIS
Document Repositories
Address Lookup
Fact Sheets

The CPUC certified the Final Environmental Impact Report (EIR) on December 17, 2009 and subsequently issued Decision 09-12-044 approving the Project.

The USDA Forest Service published a Final EIS for the Project in September 2010. Following release of the Final EIS, the Forest Service issued a Record of Decision (ROD) (13.4MB) approving the requested Special Use authorization for the Project on October 4, 2010.

The Approved Project includes a combination of Alternative 2 (SCE's Proposed Project), Alternative 3 (West Lancaster Alternative), Alternative 6 (Maximum Helicopter Construction in the ANF), and Alternative 7 (66-kV Subtransmission). Additionally, on July 11, 2013 in Decision 13-07-018, the CPUC granted the City of Chino Hills' Petition for Modification of Decision 09-12-044 filed October 28, 2011, which includes undergrounding of the 500-kV transmission line in the existing right-of-way (ROW) along an approximately 3.5-mile portion of the TRTP alignment through Chino Hills in lieu of the previously approved overhead transmission line. SCE will now be required to place the subject portion of the TRTP transmission line underground using a single-circuit, two cable per phase design (known as Option UG5) using cross-linked polyethylene (XLPE) cable. This will also include the construction of a ductbank system and structures for a third cable in the future, if necessary. The underground portion of the transmission line will run in a southwest to northeast direction, with the southwest end terminating in a transition station to be located just west of the end of Eucalyptus Avenue and the northeast end terminating in a transition station to be located adjacent to State Route (SR) 71 (Chino Valley Freeway). The environmental effects of undergrounding the TRTP through Chino Hills were analyzed in an Addendum to the TRTP Final EIR (provided below).

The CPUC and USFS also prepared a Supplemental EIR/EIS (SEIR/SEIS) for the proposed changes requested in SCE's Petition for Modification of Decision 09-12-044 on the TRTP. The SEIR/SEIS addressed implementation of the Federal Aviation Administration (FAA) recommendations including: installation of marker balls on 276 transmission line spans; installation of aviation lights on 90 transmission structures; and engineering refinements to reduce the height of 21 structures within Segment 8 between Chino and Mira Loma Substations utilizing a combination of shorter tubular steel poles and specially designed dead-end lattice steel towers, which would result in changing the previously approved structure type for seven structures. The CPUC issued a Final Decision (Decision 13-10-062) for the FAA related changes on October 31, 2013, for non-ANF lands. A final ROD for the FAA changes on ANF lands was issued by the USFS on October 17, 2014.

Construction Progress and Mitigation Monitoring

Construction started in April 2010 with the establishment of some construction yards and expansion of the existing Vincent Substation in Acton. Notices to Proceed (NTPs) were issued by CPUC for each of these activities. The majority of construction started in June/July 2010 as CPUC issued NTPs for each segment and substation of the Project. As final engineering was completed and as construction necessitated, minor permanent modifications were made to the Project. A summary of NTPs and modifications issued for TRTP is provided here. Issuance of NTPs was contingent upon SCE's compliance with pre-construction requirements as specified by the approved mitigation measures and responsible agency permitting requirements. At times, minor temporary changes were required to address construction constraints. A summary of these minor temporary changes is provided here. Each of these requests was reviewed by CPUC to ensure that no new impacts or increase in impact severity would result from the requested change. Compliance plans were developed as required by the mitigation measures and submitted to the CPUC for review and approval prior to construction. A listing of major compliance plans requiring CPUC and/or permit agency review and approval is provided here. Other responsible agency permits required for construction, and their amendments, are listed here.

Status of Construction

Construction of TRTP has been completed, and complete Project energization occurred on December 15, 2017. Post-construction activities include restoration and Stormwater Pollution Prevention Plan (SWPPP) compliance as described below.

CPUC Environmental Monitors (EMs) monitored construction activity since its start to ensure that construction was conducted in accordance with the approved mitigation measures and permit conditions. Weekly reports documenting construction and monitoring activities are posted here.

As construction was completed, SCE has been required to restore temporary construction disturbance areas. The plans detailing those restoration efforts are provided here. CPUC EMs have been monitoring restoration activities and SWPPP compliance at project disturbance areas. Monthly reports documenting SCE's restoration activities and SWPPP monitoring can be found here. For permanent loss of habitat due to TRTP structures and ancillary facilities, SCE was required to purchase offsite mitigation lands that would be managed in perpetuity as permanent habitat.

For questions, comments, or complaints related to the TRTP construction, please contact us by email at the address below. Please include your name and phone number so that we may contact you for follow-up clarification.

Project Background and Description

The Project, as approved, includes new and upgraded transmission infrastructure along approximately 173 miles of new and existing ROW from the Tehachapi Wind Resource Area (TWRA) in southern Kern County south through Los Angeles County and the ANF and east to the existing Mira Loma Substation in Ontario, San Bernardino County, California. The major components of Project have been separated into eight distinct segments (Segments 4 through 11). Under separate application to the CPUC, SCE previously requested approval for Segments 1, 2, and 3 of the Antelope Transmission Project. The major components of the Project are as follows:

• Two new single-circuit 220-kilovolt (kV) transmission lines traveling in parallel approximately 4 miles over new right-of-way (ROW) from the Cottonwind Substation (not part of this project) to the new Whirlwind Substation (Segment 4 - 220 kV). NOTE: Since approval of the TRTP, the Cottonwind Substation has not been built; the two projects that were anticipated to connect to the Cottonwind Substation now connect directly to the Whirlwind Substation utilizing the two "Cottonwind-Whirlwind" positions. The two single-circuit 220-kV transmission lines approved as part of Segment 4 are no longer necessary and have not been built.
  
  
• A new single-circuit 500-kV transmission line, initially energized to 220 kV, traveling approximately 16.0 miles over new ROW from the new Whirlwind Substation to the existing Antelope Substation (Segment 4 - 500 kV).
  
  
• Replace approximately 17.4 miles of the existing Antelope-Vincent 220-kV transmission line and the existing Antelope-Mesa 220-kV transmission line with only one new transmission line built to 500-kV standards in existing ROW between the existing Antelope Substation and the existing Vincent Substation (Segment 5).
  
  
• Rebuild approximately 31.9 miles of existing 220-kV transmission line to 500-kV standards from existing Vincent Substation to the southern boundary of the ANF. This segment includes the rebuild of approximately 26.9 miles of the existing Antelope-Mesa 220-kV transmission line and approximately 5 miles of the existing Rio Hondo-Vincent 220-kV No. 2 transmission line (Segment 6).
  
  
• Rebuild approximately 15.8 miles of existing 220-kV transmission line to 500-kV standards from the southern boundary of the ANF to the existing Mesa Substation. This segment would replace the existing Antelope-Mesa 220-kV transmission line (Segment 7).
  
  
• Rebuild approximately 33 miles of existing 220-kV transmission line to 500-kV standards from a point approximately 2 miles east of the existing Mesa Substation (the "San Gabriel Junction") to the existing Mira Loma Substation (Segment 8A). This segment would also include the rebuild of approximately 7 miles of the existing Chino-Mira Loma No. 1 line from single-circuit to double-circuit 220-kV structures (Segment 8B).A new circuit between Chino Substation and approximately 0.8 mile west of the Mira Loma Substation (6.4 miles) would also be installed on the new double-circuit 500-kV structures built as part of Segment 8A (Segment 8C).
  
  
• Removal of twelve former 220 kV tower locations, five 500 kV Lattice Steel Towers (LSTs) and foundations, and eleven 500 kV Tubular Steel Poles (TSPs) and foundations within the city of Chino Hills and Chino to support construction of 500 kV Underground in place of overhead transmission construction.
  
  
• Construct 3.7 miles underground 500 kV transmission, which will include the installation of 14 cable splice vault clusters, 6 restraint vault sites, and 16 communication vaults. Installation of approximately 17,000 feet of duct bank, approximately 14,500 feet of bundled High Density Polyethylene (HDPE) conduit via horizontal directional drilling (HDD), and approximately 20,000 circuit feet of cable. Replacement of 16 gas pipeline crossings and relocation of distribution and telecom. Development and construction of an Eastern and Western Transition Stations, with the installation of two DC 500 kV LST structures.
  
  
• Construct the Whirlwind Substation, a new 500/220-kV substation located near the intersection of 170th Street and Holiday Avenue in Kern County near the TWRA (Segment 9).
  
  
• Upgrade of the existing Antelope, Vincent, Mesa, Gould, and Mira Loma Substations to accommodate new transmission line construction and system compensation elements (Segment 9).
  
  
• Build a new 500-kV transmission line traveling approximately 16.8 miles over new ROW between the approved Windhub Substation (not part of this project) and the new Whirlwind Substation (Segment 10).
  
  
• Rebuild approximately 18.7 miles of existing 220-kV transmission line to 500-kV standards between the existing Vincent and Gould Substations. This segment would also include the addition of a new 220-kV circuit on the vacant side of the existing double-circuit structures of the Eagle Rock-Mesa 220-kV transmission line, between the existing Gould Substation and the existing Mesa Substation (Segment 11).
  
  
• Install associated telecommunications infrastructure.

Project Location

Maps of the proposed transmission routes can be viewed here.

To find the location of your property in relation to the proposed transmission routes, click here and enter your property address.

Additional Project Documents

Addendum to Final EIR (7.7MB). The CPUC prepared an Addendum to the October 2009 Final EIR for the TRTP pursuant to the CEQA (Pub. Res. Code §21000 et seq.) and the State CEQA Guidelines (14 Cal. Code Regs §15000 et seq.). In November 2011, the CPUC issued an Assigned Commissioner's Ruling directing SCE to prepare testimony on new options for the portion of the TRTP known as Segment 8A that traverses the City of Chino Hills. In response, testimony was submitted by SCE in January 2012 on options to the approved TRTP in Chino Hills. These options included alternative routes, different types of overhead structures, and undergrounding options. In response to the Scoping Memo and Ruling of Assigned Commissioner issued on July 2, 2012, as amended, SCE submitted preliminary testimony in December 2012 describing five underground transmission options for Chino Hills. On February 28, 2013, SCE submitted refined testimony on the underground options.

An Addendum was prepared to address proposed changes to the TRTP along a portion of Segment 8A in the City of Chino Hills. Specifically, options have been considered for placing either a 500-kV single-circuit or 500-kV double-circuit transmission line underground in an approximately 3.5-mile segment of existing right-of-way (ROW) through Chino Hills. The CPUC originally approved the construction of a 500-kV double-circuit overhead transmission line through this portion of Chino Hills as part of the TRTP.

Final EIS. The Final EIS for the TRTP was released by the Forest Service on September 14, 2010. The Final EIS includes responses to all comments received on the Draft EIR/EIS, as well as responses to comments received on the Supplemental Draft EIS. The Final EIS contains much of the same content as the Final EIR; however, information and analysis that has not changed substantively from the Final EIR has not been reproduced in the Final EIS, particularly information about conditions and impacts on non-federal lands.

Supplemental Draft EIS. The Forest Service published a Notice of Intent to prepare a Supplemental Draft EIS in the Federal Register on February 8, 2010. The Forest Service released the Supplemental Draft EIS on April 30, 2010. The Supplemental Draft EIS assessed the changed conditions in the Angeles National Forest created by the 2009 Station Fire.

General Conformity. The Forest Service prepared a Draft Conformity Determination for the TRTP. The Draft Conformity Determination was released for a 30-day public review period, as required under 40 CFR §93.156, on March 22, 2010. Responses to comments received on the Draft Conformity Determination were incorporated into the Final Conformity Determination. The Forest Service approved the Final Conformity Determination for the TRTP on June 2, 2010.

Final EIR. The Final EIR was released on October 30, 2009 (Notice of Availability of the Final EIR). The Final EIR includes responses to all comments received on the Draft EIR/EIS during the public review period (February 13 through April 6, 2009).

Draft EIR/EIS. The CPUC and the USDA Forest Service released the Draft EIR/EIS on February 13, 2009. Revisions to the Draft EIR/EIS are reflected in the Final EIR (see link above).The Final EIR contains the entire content of the Draft EIR/EIS along with responses to comments received on the Draft EIR/EIS during the public review period.

Notices

Notice of Preparation for the Draft SEIR/SEIS. To initiate the EIR process, a Notice of Preparation (NOP) was distributed by the CPUC on September 24, 2012.

The NOP was advertised in local newspapers throughout the Project area. The Notice of Preparation (English) can be viewed here. Translated versions of the NOP can be viewed in Chinese, Spanish, and Korean.

To initiate the SEIS process, the Forest Service published its Notice of Intent to prepare a SEIR/SEIS in the Federal Register on September 24, 2012.

Notice of Availability of the Draft EIR/EIS. When the CPUC and the Forest Service published the Draft EIR/EIS, a Notice of Availability (NOA) was distributed to the public on February 13, 2009. The NOA (English) can be viewed here. Translated versions of the NOA can be viewed in Chinese, Spanish, and Korean.

Notice of Preparation for the Draft EIR/EIS. To initiate the EIR process, a Notice of Preparation (NOP) was distributed by the CPUC on August 31, 2007. The NOP (English) can be viewed here. Translated versions of the NOP can be viewed in Chinese, Spanish, and Korean.

Notice of Intent. To initiate the EIS process, the USDA Forest Service published its Notice of Intent to prepare an Environmental Impact Statement in the Federal Register (Volume 72, No. 173, page 51404) on September 7, 2007.

Other Project Documents

Comment Summary Report. The Comment Summary Report and its appendices, which document and summarize the public meeting that was held on January 17, 2008, in Brea, CA, are available here.

Scoping Report. The Scoping Report and its appendices, which document and summarize the public scoping process, including comments received on the proposed Project, are available here.

Policy Consistency and Plan Amendments Report. The Policy Consistency and Plan Amendments Report, which provides a review of relevant federal, State, regional, and local agency plans and planning documents, is available here (4.3MB).

Fact Sheets. Several Fact Sheets are available that provide information on aspects of electrical transmission that frequently interest the public. These Fact Sheets were provided at all of the public scoping meetings and are also available here.

Proponent's Environmental Assessment (PEA). As part of its application to the CPUC, SCE prepared and submitted a Proponent's Environmental Assessment (PEA), which describes the proposed project, existing environmental conditions in the project area, and potential environmental impacts. The PEA may be viewed here.

Contact Information