Web Content Viewer (JSR 286)

Circle City Substation & Mira Loma-Jefferson Sub-Transmission Line Project

The Circle City Substation and Mira Loma-Jefferson Sub-transmission Project are important infrastructure upgrades that will enable us to safely and reliably meet increased demand for electricity in this region.

Neighboring Communities

This project will serve the cities of Corona, Norco, Chino, Eastvale, and Ontario. 

Project Details

This project includes the following:

  • Construction of a new distribution substation and source lines on approximately 11 acres in Corona. A distribution substation is a facility where electricity is lowered to a voltage that can be distributed and used by households and businesses.
  • Construction of the Mira Loma-Jefferson line, a 66 kV sub-transmission line approximately 10.7 miles in length. A combination of both overhead and underground construction, it would be constructed from the existing Mira Loma Substation in Ontario to a location adjacent to the existing Corona Substation in Corona.


SCE submitted its Permit-to-Construct application to the California Public Utilities Commission. The project is currently in the regulatory review process.

Project Timeline

  • Starting in 2009: Project planning and public outreach activities.
  • 4th quarter, 2015: SCE plans to file the project with the CPUC.
  • 2019: Subject to all necessary regulatory approvals, project construction is anticipated to begin.
  • 2021: Project expected to be operational and in-service.

Contact Information

If you have questions about this project, please call our toll-free project hotline at 1-866-464-2005.

Interested in working with SCE as a supplier? Learn more.

For More Information

CPUC link to the project website

Web Content Viewer (JSR 286)