Pacific Gas & Electric Company's Proposed Windsor Substation Project

(Application A.10-04-024, filed April 21, 2010)

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Welcome to the California Public Utilities Commission (CPUC) website for Pacific Gas and Electric's (PG&E's) proposed Windsor Substation Project. An application for this project was submitted to the CPUC on April 21, 2010 (A.10-04-024). The project was reviewed by CPUC in accordance with the California Environmental Quality Act (CEQA) and a Mitigated Negative Declaration (MND) was prepared.

This site provides access to public documents and information relevant to the permitting, CEQA review, and construction of the Windsor Substation Project.


The Final MND was adopted by the CPUC on April 3, 2014 in Decision D.14-03-031. In accordance with CEQA, a Mitigation Monitoring, Compliance, and Reporting Plan (MMCRP) was prepared to ensure compliance with the mitigation measures approved in the MND. The MMCRP is available here (6.4MB). PG&E started construction of the Windsor Substation Project in November 2016 and completed construction in June 2018. The Final Monitoring Report can be found here.

Pre-construction Compliance

Notices to Proceed (NTPs) are being issued by CPUC by subsection of the project as requested by PG&E. NTP #1 for the construction of the substation component of the project was issued by CPUC on June 15, 2016, and is available here. NTP #2 for the reconductoring work along Old Redwood Highway and the Fulton No. 1 line was issued by CPUC on March 30, 2017, and is available here. Issuance of NTPs is contingent upon PG&E's compliance with pre-construction requirements as specified by the approved mitigation measures and responsible agency permitting requirements.

Other responsible agency permits required for construction, and their amendments, are listed in the MMCRP (see above). Prior to construction, PG&E was required to submit the following surveys and plans/programs. Surveys were field validated by the CPUC EM:

  • Sensitive Biological Habitat Survey Reports
  • Bird Nesting Survey Reports
  • Special-status Bat Survey Reports
  • Restoration Plans
  • Storm Water Pollution Prevention Plans (SWPPPs)
  • Construction Site Monitoring Program (CSMP)
  • Worker Environmental Awareness Program Plans

Other compliance plans requiring CPUC and/or permit agency review and approval included the following:

  • Landscaping Plan (available here)
  • Spill Prevention Control and Countermeasure Plans (available here)
  • Hazardous Substance Control and Emergency Response Plan (available here)

Construction Monitoring and Minor Project Change Review

Construction activities began November 2, 2016. CPUC Environmental Monitors are monitoring construction activities to ensure that construction is being conducted in accordance with the approved mitigation measures and permit conditions. Monitoring reports documenting construction and compliance can be viewed here.

As final engineering is completed or as construction necessitates, Minor Project Changes (MPCs) are being submitted for the Project. Each of these requests is reviewed by CPUC to ensure that no new impacts or increase in impact severity would result from the requested change. Table 1 provides a summary of the MPCs submitted for the Windsor Substation Project.

Table 1. Minor Project Changes (MPCs)
Phase Description
MPC #1
Approved under NTP #1
Windsor Substation Design change to Spill Prevention Control and Countermeasure (SPCC) retention pond and stormwater flow. MPC #1 was incorporated into NTP #1.
MPC #2
Approved under NTP #1
Windsor Substation Use of water truck or driwater pods instead of irrigation system for landscaping. MPC #2 was incorporated into NTP #1.
MPC #3
Approved under NTP #1
Windsor Substation Replacement of culverts in existing roadways entering substation site and Herb Lane. MPC #3 incorporated into NTP #1.
MPC #4
Windsor Substation Revision of the Conceptual Landscape Plan based on final design and engineering.
MPC #5
Approved under NTP #2
Reconductoring & 12 kV Line Underbuild Use of crane staged on SMART tracks to replace certain poles along the Fulton No. 1 Power Line submitted with NTP Request #2.
MPC #6
Approved under NTP #2
Reconductoring & 12 kV Line Underbuild Final design and engineering revision to the tubular steel pole (TSP) west of the substation submitted with NTP Request #2.
MPC #7
Approved under NTP #2
Reconductoring & 12 kV Line Underbuild Changes to tree trimming and removal due to construction method changes (crane use on SMART tracks) submitted with NTP Request #2.
MPC #8
Approved under NTP #2
Reconductoring & 12 kV Line Underbuild Additional pull and tension site located on Railroad Avenue between Poles a32 and a33 submitted with NTP Request #2.
MPC #9
Reconductoring & 12 kV Line Underbuild Reconfiguration of distribution line crossing of Old Redwood Highway and pole changes.
MPC #10 revised
Reconductoring & 12 kV Line Underbuild Use of an additional temporary staging yard.
MPC #11
Reconductoring & 12 kV Line Underbuild Increase the height of pole a35 on the Fulton No. 1 60 kV line.
MPC #12
Reconductoring & 12 kV Line Underbuild Use of drone instead of ground equipment to facilitate installing the new distribution underbuild on the Fulton No. 1 60 kV line.


Project Description

The originally proposed Windsor Substation Project site was located on Mitchell Lane in the southern part of the Town of Windsor, Sonoma County, California. Subsequent to its original Application, PG&E amended its Application and submitted a Supplemental PEA for substation sited at a different location. The new site is in the northern part of the Town, on Old Redwood Highway at Herb Road, between Highway 101 and the Northwestern Pacific Railroad (NWPRR) right of way.

Electrical power would enter the substation by tapping the existing Fulton No. 1 60 kV power line that parallels the west side of the NWPRR right of way. Electrical power would leave the substation as 12 kV via distribution feeder lines, which would interconnect with the distribution network. Construction involves the installation of the following components:

  • Construction of a 3-bank 115/12 kilovolt substation on 2.6 acres of a 4.11-acre parcel on Old Redwood Highway at Herb Road in the Town of Windsor, California. The substation would consist of the following at full buildout:

    • Three 115 kV bus structures
    • Six 115 kV circuit breakers
    • Three 115/12 kV power transformers
    • Eighteen 115 kV disconnecting switches
    • Three 12 kV metal-clad switchgear enclosures
    • Twelve 12 kV distribution circuits
    • Three 30 MVA power transformers
    • Connection of the new substation to on the Fulton No. 1 60 kV power line by way of a new tubular steel pole [TSP] replacing an existing wood pole
    • Two 42-foot-high dead-end structures within the substation supporting the 60 kV power line entering and exiting the substation

  • Pole replacement and line work along Old Redwood Highway, Starr Road, Gumview Road, Wilcox Road, Starr Circle, Railroad Avenue and Joni Court.

  • Underground distribution lines connecting the substation to existing and future infrastructure.

  • Rebuilding approximately 1.5 miles of the existing Fulton No. 1 60 kV power line, requiring replacement 39 wooden poles (with 38 wood poles and 1 steel pole) and installation of 2 new wood riser poles.

  • Reconductoring approximately 1.8 miles of existing distribution line with 12 kV double-circuit conductor along Old Redwood Highway, requiring replacement of 44 wooden poles with taller wood poles and installation of 3 additional wood riser poles.

Proponent's Environmental Assessment (PEA)

PG&E filed a PEA with the Application in April 2010. A Supplemental PEA was submitted in May 2011. The PEA provides a starting point for the independent environmental review process conducted by the CPUC. In addition, PG&E's Notice of an Application for a Permit to Construct can be found here.

Environmental Review Process

PG&E's Application and PEA were deemed complete for review by the CPUC on May 20, 2010. However, the PEA was replaced by the Supplemental PEA, submitted in 2011. The CPUC evaluated the substation site and related project elements identified in the Supplemental PEA.

The CPUC determined that an Initial Study/Mitigated Negative Declaration (IS/MND) appeared to be the appropriate CEQA document to prepare for this project. After it was prepared, the Draft IS/MND was published and the public and agencies had an opportunity to comment on the document. Based on the Draft IS/MND, CPUC determined that an EIR was not required.

Draft Initial Study/Mitigated Negative Declaration

On July 15, 2013, the CPUC released a Notice of Intent to Adopt a Mitigated Negative Declaration for the Windsor Substation Project showing that the Proposed Project, as mitigated, would not have any significant effects on the environment. The Draft Mitigated Negative Declaration and Supporting Initial Study (IS/MND) can be viewed here.

The Draft IS/MND underwent a public review period from July 15, 2013 through August 14, 2013.

Final Initial Study/Mitigated Negative Declaration

After the close of the comment period, CPUC prepared a Final Mitigated Negative Declaration for the Windsor Substation Project. The Final IS/MND can be viewed here. The study showed that the Proposed Project, as mitigated, would not have any significant effects on the environment. The Final MND provides details on the Proposed Project, evaluates and describes its potential environmental impacts, identifies those impacts that could be significant, and presents mitigation measures to avoid or minimize these impacts.

Public Information Meeting

The CPUC Energy Division held a public information meeting on August 16, 2010, to describe the then-proposed project, describe the CEQA process, and receive public comments on the proposal. Written comments were submitted at this meeting. Subsequent to the meeting, PG&E identified its alternate site and submitted a supplemental PEA.

For Additional Information

To request additional information, please contact:

Eric Chiang, Project Manager
California Public Utilities Commission
c/o Aspen Environmental Group
235 Montgomery Street, Suite 935
San Francisco, CA 94104-3002

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