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Construction has commenced


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CPUC Proceeding
A.15-03-003 - Proceeding

Welcome to the California Public Utilities Commission (CPUC) website for the California Environmental Quality Act (CEQA) review of proposed construction of the Mesa 500-kV Substation Project (Mesa Substation Project). On March 13, 2015, SCE filed an application [Application No. A.15-03-003] for a Permit to Construct (PTC) with the CPUC to rebuild and upgrade a portion of its transmission infrastructure primarily within the Western Los Angeles Basin Electrical Needs Area. The majority of would take place in the City of Monterey Park with some work occurring in nearby cities and portions of unincorporated Los Angeles County. If the proposed project is approved, the existing 220/66/16-kV Mesa Substation would be upgraded to a 500/220/66/16-kV substation.

In accordance with CEQA, the CPUC, as the Lead Agency, is required to conduct a review of the environmental impacts of the proposed project and has prepared an Environmental Impact Report (EIR). This site provides access to public documents and information relevant to the CEQA review process. Additional project information and documentation will be posted as it becomes available.

Construction of the project began in September 2017. Information about the CPUC’s monitoring of construction activities for environmental compliance is provided under Construction and Mitigation Monitoring below.

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Project Description

Major components of the Mesa Substation Project include the following:

Construction of the new 500/220/66/16-kV substation and demolition of the existing 220/66/16-kV substation would occur in phases. Phase 1 would consist of grading and initial site development on the western portion of the project site. Phase 2 would consist of construction of the first half of the new Mesa Substation. During Phase 1 and 2, the existing substation on the eastern portion of the site would remain operational in order to maintain electrical service to customers during construction. Phase 3 would consist of demolition of the existing substation and construction of the second half of the new substation on the eastern portion of the site. Construction of the Mesa Substation Project is anticipated to begin in 2017 and would take approximately 4.5 years.

Project Location

The Proposed Project is located in Los Angeles County, California, primarily in the City of Monterey Park where the existing 220/66/16-kV Mesa Substation would be demolished and the new 500/220/66/16-kV Mesa Substation would be constructed. Other major components will be located within portions of Monterey Park, Montebello, Rosemead, South El Monte, Commerce, Bell Gardens, Pasadena, Industry, Santa Clarita, and in portions of unincorporated Los Angeles County.

Application and Proponent’s Environmental Assessment

SCE filed an application (A.15-03-003) for a PTC and Proponent's Environmental Assessment (PEA) for the proposed project on March 13, 2015. The PEA provides information to begin the independent environmental review process conducted by the CPUC. On April 2, 2015, the CPUC sent a deficiency letter to SCE, which requested additional information needed in order to deem the application complete. SCE provided a response to Deficiency Letter #1 on April 30, 2015. Following review of SCE’s response, the CPUC deemed the application complete on May 15, 2015.

Data Requests and Responses

The CPUC reviewed the application and PEA to identify additional data needed from the Applicant to complete the environmental review process. The CPUC submitted data requests to the applicant for specific information to support the environmental review process. Those requests and the applicant's responses are included below.

CPUC Request SCE’s Response Attachments
Data Request #1 (5/22/15) DR #1 Response (Part 1) (6/5/15)
DR #1 Response (Part 2) (6/9/15)
DR #1 Response (Part 3) (6/16/15)
Response Attachments
Data Request #1 Follow Up (6/25/15) DR #1 Follow Up Response (Part 1) (7/22/15)
DR #1 Follow Up Response (Part 2) (8/5/15)
DR #1 Follow Up Response (Part 3) (8/3/15).1
Response Attachments
Data Request #1 Follow Up 02 (8/14/15) DR #1 Follow Up 02 Response (8/31/15)
Response Attachments
Data Request #1 Follow Up 03 (9/1/15) DR #1 Follow Up 03 Response (9/16/15)
Response Attachments
Data Request #2 (7/22/15) DR #2 Response (Part 1) (8/1/15)
DR #2 Response (Part 2) (8/17/15)
DR #2 Response (Part 3) (8/18/15)
Data Request #2 Follow Up (8/6/15) DR #2 Follow Up Response (8/27/15)
Response Attachments
Data Request #3 (9/1/15) DR #3 Response (9/16/15)
Response Attachments
Data Request #4 (9/16/15) DR #4 Response (Part 1) (10/2/15)
DR #4 Response (Part 2) (10/2/15)
DR #4 Response (Part 3) (10/9/15)
Response Attachments
Data Request #5 (9/18/15) DR #5 Response (Part 1) (10/2/15)
DR #5 Response (Part 2) (10/8/15)
DR #5 Response (Part 3) (10/13/15)
Data Request #6 (10/30/15) DR #6 Response (11/17/2015)
Data Request #7 (11/18/15) DR #7 Response (12/3/2015)
Answer Q.1 Attachment (Pre-Project Contingency List)
1. Revised visual simulations provided in response to Data Request #1 Follow UP Q.19 show a 10 ft. wall. Consistent with the current proposed project, these simulations will be revised to reflect a 12 ft. wall.

During the public comment period for the Draft EIR, SCE submitted a comment letter to the CPUC. After reviewing the comment letter, the CPUC sent a data request to SCE. SCE provided responses on 7/15/16 and 8/3/16. The requests and responses are included in the table below.

CPUC Request Response Attachments
Data Request #8 - to SCE (7/22/16) DR #8 Response (8/4/16)
Response Attachments

During the public comment period for the Draft EIR, the California Independent System Operator (CAISO) submitted a comment letter to the CPUC. After reviewing the comment letter, the CPUC sent a data request to CAISO and received a response as indicated below.

CPUC Request Response Attachments
Data Request #1 - to CAISO (7/20/16) CPUC received CAISO’s response on 8/3/16 N/A

After the release of the Draft EIR (April 2015), the following data requests were submitted to the CPUC. The responses to these data requests have been provided to assist the parties in providing comments on the Draft EIR.

SCE Request CPUC's Response Attachments
Data Request #1 (5/16/16) DR #1 Response (5/23/216) Attachment 1 (Written Responses to SCE’s Data Request)

Public Scoping and Notice of Preparation of an EIR

On June 5, 2015, the CPUC published a Notice of Preparation (NOP) indicating that an EIR would be prepared. The NOP, which includes a figure depicting an overview of project components, is located here.

Publication of the NOP initiated a public comment period beginning June 5, 2015, and ending at 5:00 pm on July 5, 2015. All interested parties, including the public, responsible agencies, and trustee agencies, were invited to learn more about the project, ask questions, and present comments about the Mesa Substation Project at the public scoping meeting. The scoping meeting was held on June 23, 2015 at the Langley Center, located at 400 W. Emerson Avenue in the City of Monterey Park, California from 6:00 p.m. until 7:30 p.m. A copy of the PowerPoint presented at the scoping meeting is located here.

In addition, all interested parties were invited to provide written scoping comments via mail, fax, or e-mail to the CPUC during the NOP comment period specified above.

Comments received during the scoping period will be considered during preparation of the Mesa Substation Project EIR. The following comments were received during the scoping period:

Written Comments Received during the Scoping Period
Name Affiliation Date Received
Local and Regional Agencies
Barbara Radlein South Coast Air Quality Management District 6/23/15
Dianna Watson California Department of Transport (Caltrans) 7/1/2015
Deborah Drezner Metropolitan Water District of Southern California (Metropolitan) 7/1/2015
Joyce Kinnear Silicon Valley Power (SVP) 7/6/2015
Tribal Representatives
Andy Salas Chairman Of Gabrieleño Band Of Mission Indians/Kizh (Kit'c) Nation 6/12/15
Individuals and Organizations
Doug Ito None 4/2/2015
Samuel B. Villalobos None 4/13/2015
Victor Pelayo None 4/13/20151
J.P. Wolk None 6/9/2015
Saul Roe None 6/12/2015
Oral Comments Received During Scoping Meeting
Samuel Villalobos None 6/23/2015
1Three separate emails were submitted by this commenter on the same date.

All scoping comments can be found here and are organized by the date that they were received.

Draft Environmental Impact Report (EIR) and Public Comment Period

As the CEQA Lead Agency, the CPUC prepared a Draft EIR for the proposed project in accordance with CEQA. Links to view the Notice of Completion, Notice of Availability, and Draft EIR are provided below. Hardcopies of the Drat EIR were available at the following repositories during the comment period:

Monterey Park Library
318 S Ramona Avenue
Monterey Park, CA 91754
(626) 307-1368
Montebello Library
1550 W Beverly Boulevard
Montebello, CA 90640
(323) 722-6551

The CPUC initiated a 45-day comment period starting April 29, 2016 extending through June 13, 2016. The CPUC extended the comment period to 60 days, and accepted written comments on the Draft EIR through June 27, 2016. All written comments must have been postmarked or received by fax or email no later than 5:00 p.m. on June 27. The comment period is now closed

The CPUC held a public meeting on May 18, 2016, to explain the proposed project, discuss the proposed project’s significant impacts, and receive written comments on the Draft EIR from the public. The meeting began with a presentation, followed by an informal discussion session. Details for the public meeting are provided below:

May 18, 2016, 6:00 p.m.
Barnes Park – Service Club House Main Room

350 S. McPherrin Ave.
Monterey Park, CA 91754

Link to the Presentation

The following comments were received on the Draft EIR:

Written Comments Received on the Draft EIR
Name Affiliation Date Received
State and Local Agencies
Betty Courtney California Department of Fish and Wildlife 6/16/2016
Deanna Watson California Department of Transport (Caltrans) 6/1/2016
Jordan Pinjuv California Independent System Operator 6/27/2016
Jillian Wong South Coast Air Quality Management District 6/10/2016
Vivian Romero City of Montebello 6/22/2016
City of Montebello, City Council Members City of Montebello 6/22/2016
Jose Jimenez City of Commerce 5/31/2016
Michael Huntley City of Monterey Park 6/23/2016
Tribal Representatives
Andrew Salas Chairman Of Gabrieleño Band Of Mission Indians/Kizh (Kit'c) Nation 5/10/2016
Non-Government Organizations
Margot Eister Save Montebello Hills 5/22/2016
Yvonne Watson Sierra Club
Margot Eiser Citizens for Open and Public Participation 6/27/2016
Josh Havelka Barnhart Crane 6/10/2016
Saul Roe None 4/30/2016
James Flournoy None 5/1/2016
Calvin Yoshitake None 5/18/2016
Marc Blodgett None 5/18/2016
Samuel Villalobos None 5/18/20161
Samuel Villalobos None 5/18/20161
Samuel Villalobos None 6/27/20161
Henry Yew None 6/27/2016
Yvonne Watson None 6/27/2016
Applicant SCE 6/27/2016
1Three separate comments were submitted by this commenter; two were received on 5/18/2016, and a third was submitted on 6/27/2016.

Final EIR

CPUC published the Final EIR on October 7, 2016. It includes comments on the Draft EIR, responses to comments on the Draft EIR, and revisions to the Draft EIR. The Final EIR is available electronically by clicking the link below.

Hard copies of the Final EIR are available at the following libraries:

Monterey Park Library
318 S Ramona Avenue
Monterey Park, CA 91754
(626) 307-1368
Montebello Library
1550 W Beverly Boulevard
Montebello, CA 90640
(323) 722-6551
Commerce Public Library
5655 Jillson Street
Commerce, CA 90040
(323) 722-6660

Final EIR Errata

The Final EIR Errata may be viewed here.

Commission Decision

On February 9, 2017 the Commission granted SCE a PTC the Mesa 500 kV Substation Facility Project, with mitigation identified in the Mitigation Monitoring and Reporting Plan. The Commission Decision (Decision 17-02-015) can be viewed here.

Construction and Mitigation Monitoring

The CPUC developed a Mitigation Monitoring, Compliance, and Reporting Program (MMCRP) in coordination with SCE to provide guidance and procedures for environmental monitoring during project construction. The MMCRP is a tool to ensure compliance with the applicant proposed measures (APMs) and mitigation measures approved in the Final EIR.

The MMCRP can be viewed here. (3 MB)

A list of mitigation plans approved for the project can be found here.

The first phase of construction began September 2017. The Notice to Proceed (NTP) approved for the project and is posted below and monthly compliance reports will be posted to this websiteare posted below

Notice to Proceed

The CPUC issues Notice to Proceed (NTPs) to the applicant for each phase of construction activity, after confirming that SCE has complied with pre-construction environmental requirements. Each NTP for the project is listed in the table below.

NTP No. Project Components/Phase NTP Request from SCE Date NTP Approved
1 Vegetation removal and grading, waterline relocation, OII well removal, and various line relocations (transmission, sub-transmission, distribution, and telecommunications). NTPR-1 September 2017 September 27, 2017
1 - Amendment NTPR-1 amended to reflect the approval of additional vegetation removal, and the increase from 12 to 16 temporary wood poles to re-route the Mesa-Walnut-Hillgen-Industry-Mesa-Reno and Mesa-Laguna Bell-Narrows 66-kV lines. NTPR-1 Amendment October 2017 October 18, 2017
2 Vegetation removal and grading, and the removal, replacement, relocation, modification, and/or construction of: walls, Mechanical Electrical Equipment Rooms, operations and test and maintenance buildings, storm drains, lattice steel towers, various poles, underground trenches, concrete foundations, and associated components. NTPR-2 additionally includes equipment modifications at 29 satellite substations. NTPR-2 November 2017 November 15, 2017

Construction Monitoring Reports

Monthly reports issued on construction progress as part of mitigation monitoring and compliance are listed here.

Construction Month Associated Notice to Proceed
October 2017 NTP-1
November 2017 NTP-1, NTP-2
December 2017 NTP-1, NTP-2
January 2018 NTP-1, NTP-2
February 2018 NTP-1, NTP-2
March 2018 NTP-1, NTP-2
April 2018 NTP-1, NTP-2
May 2018 NTP-1, NTP-2
June 2018 NTP-1, NTP-2
July 2018 NTP-1, NTP-2
August 2018 NTP-1, NTP-2
September 2018 NTP-1, NTP-2
October 2018 NTP-1, NTP-2
October 2018 NTP-1, NTP-2
November 2018 NTP-1, NTP-2
December 2018 (3.1 MB) NTP-1, NTP-2
January 2019 (5.1 MB) NTP-1, NTP-2
February 2019 (8.9 MB) NTP-1, NTP-2
March 2019 (10.6 MB) NTP-1, NTP-2
April 2019 (7.2 MB) NTP-1, NTP-2
May 2019 (10.5 MB) NTP-1, NTP-2
June 2019 (9.4 MB) NTP-1, NTP-2
July 2019 (9.9 MB) NTP-1, NTP-2
August 2019 (8.2 MB) NTP-1, NTP-2
September 2019 (5.9 MB) NTP-1, NTP-2
October 2019 (10.7 MB) NTP-1, NTP-2
November 2019 (6.6 MB) NTP-1, NTP-2
December 2019 (5.7 MB) NTP-1, NTP-2
January 2020 (8.7 MB) NTP-1, NTP-2
February 2020 (6.5 MB) NTP-1, NTP-2
March 2020 (9.1 MB) NTP-1, NTP-2
April 2020 (9.7 MB) NTP-1, NTP-2
May 2020 (7.7 MB) NTP-1, NTP-2
June 2020 (7.1 MB) NTP-1, NTP-2
July 2020 (5.6 MB) NTP-1, NTP-2
August 2020 (5.2 MB) NTP-1, NTP-2
September 2020 (6.0 MB) NTP-1, NTP-2
October 2020 (6.2 MB) NTP-1, NTP-2
November 2020 (5.5 MB) NTP-1, NTP-2
December 2020 (7.8 MB) NTP-1, NTP-2
January 2021 NTP-1, NTP-2
February 2021 NTP-1, NTP-2
March 2021 (2.4 MB) NTP-1, NTP-2
April 2021 (1.1 MB) NTP-1, NTP-2
May 2021 (1.3 MB) NTP-1, NTP-2
June 2021 (1.8 MB) NTP-1, NTP-2
July 2021 NTP-1, NTP-2

Minor Project Changes

SCE may submit Minor Project Changes (MPCs) for project changes that are not major enough to warrant potential revision of the certified CEQA document. The CPUC will review any MPCs submitted by SCE per the process described in the MMCRP. Each MPC request submitted for the project is listed in the table below.

MPC No. Description Date CPUC Approval
001 Use of driveway off Greenwood Ave. October 9, 2017
002 CPUC identified that requested changes did not require a full MPC, and that actions were permitted N/A
003 (4.7 MB) Three new poles with wires across Potrero Grande Drive February 5, 2019
004 Installation of eight temporary wooden poles in approved workspaces to reroute 66-kV circuits and install tubular steel poles March 14, 2019
005 Installation of new switches on three 66-kV circuits February 18, 2019
006 Relocation of 16-kV conduit under several poles August 9, 2019 (4.4 MB)
007 Access to 12 existing fiber splice cases on existing poles, manholes, or vaults to install communication between substations October 2, 2019
008 Installation of 500 feet of new 5-inch conduit with a trench 2 feet wide and 5 feet deep August 23, 2019
009 Installation of 600 feet of new 5-inch conduit adjacent to the Service Center driveway October 22, 2019
010 Installation of a raptor nest platform on a temporary wood pole in an approved work area (NTRP-1) February 26, 2020
011 Installation and/or removal of jumper loops at existing SCE structures to create a new, temporary circuit from two existing circuits (NTPR-1) MPC request 011 was submitted on March 12, 2020. On March 20, 2020, MPC request 011 was withdrawn and determined no longer needed due to developments with respect to cutover work/sequencing in conjunction with outages.
012 Grounding work at two existing structures within the ROW March 26, 2020
013 Repositioning a 500-kV lattice steel tower at Construction 5001 135 feet north January 19, 2021
014 Accessing 199 existing fiber splice cases to remove idled copper cables between satellite substations (NTPR-2) May 21, 2021

Non-Compliance Reports

Non-compliance reports (NCR) are issued by the CPUC to SCE for non-compliance incidents. NCRs include a non-compliance level of 1, 2, or 3, depending on the potential or actual risk to environmental resources caused by the non-compliance event. More information about the levels and NCRs is included in the MMCRP.

NCR No. Type of Incident/Resources at Risk Level
001 Biological Resources – repeated occurrences of crews entering work areas prior to biological sweep 2
002 Spill Prevention, Countermeasure, and Control Plan – failure to notify CPUC before additional transformer oil was brought onsite 2
003 Biological Resources – crews removed inactive nest material before the area was swept by a biologist; self-issued by SCE 2
004 Spill Prevention, Countermeasure, and Control Plan, Stormwater Pollution Prevention Plan – detention basin design did not function as a secondary containment facility as required by the SPCC, and sediment-laden water in violation of the project SWPPP escaped from the construction site 2
005 Public storm drain system, Stormwater Pollution Prevention Plan – muddy track out was observed on Market Place Drive and Potrero Grande Road. Construction activities lead to severe erosion resulting in off-site sediment transport onto public roads 1
006 Hazardous Materials – PGI uncovered transite pipe (asbestos-cement material) within the Mesa Substation and staged the material 40 feet east. PGI is not authorized to handle or excavate asbestos. This action conflicted with MM HZ-4 2
007 Stormwater from recent rain events were circumventing erosion and sediment control best management practices (BMPs) installed on the banks of the far west basin on Markland Drive, eroding soil at the base, and accumulating in the basin. As a result, heavy sediment-laden water accumulated in the basin over time and was not draining within 96 hours (per the CASQA BMP Fact Sheet for basins), and therefore a vector control issue was discovered post 1
008 Stormwater Pollution Prevention Plan – rainwater circumvented several erosion control BMPs and eroded on-site soils leading to potential signs of off-site sediment transport via the public stormdrain 2

Administrative Law Judge’s Proceeding

For information about the proceeding or to find out how you can participate in the proceeding, please click the following link and enter the proceeding number (1503003):

Link to the Proceeding

For Additional Information

To request additional information or to be added to the mailing list, please contact us by email, fax, or phone, as follows:

Project email: Mesa.CPUC@ene.com
Project fax: 415-796-0846
Project voicemail: (844) 538-6992 (toll free)

California Public Utilities Commission
RE: Mesa Substation Project
c/o: Ecology and Environment, Inc.
50 California Street, Suite 1500
San Francisco, CA 94111

The CPUC’s Project Manager is:

Connie Chen, CPUC Project Manager
California Public Utilities Commission
Energy Division
Infrastructure Permitting and CEQA
505 Van Ness Avenue
San Francisco, CA 94102
Email: Connie.Chen@cpuc.ca.gov