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.
Southern California Edison has proudly served the city of Corona for many years, and as the city has grown, we have grown with it by investing in new infrastructure that ensures the delivery of safe, affordable and reliable power.
The City of Corona is enjoying an expanding job market, new industrial growth and a thriving housing market. To meet the demand of Corona’s growth, Southern California Edison has proposed the Circle City project.
Between 2010 and 2015, Corona’s population grew 7.8%, compared to surrounding cities such as Ontario and Riverside with 4.4% and 6.1% growth, respectively. To keep up with Corona’s progress, new electrical infrastructure is needed. Additionally, households across Southern California are using energy in a much different way than they did 10 years ago, and SCE is committed to ensuring that customers’ needs are met.
Like Corona, progress is important to SCE, which is why the utility is preparing your local grid for more rooftop solar, onsite energy storage and the growing adoption of electric vehicles.
For more information on how SCE is making the grid better, please see - Making Vision a Reality
For more information on the Circle City Project, please see below.
This project will serve the cities of Corona, Norco, Chino, Eastvale, and Ontario.
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.
- 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.
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.
Maps & Resources
Additional Project Details
- Project Summary/Overview
- Project Summary/Overview (Spanish)
- Visual Simulation from River Road Park
- Visual Simulation from Magnolia Ave near Sherborn St
- Visual Simulation from Magnolia Ave near S Promenade Ave
- Visual Simulation from Interstate 15
- Visual Simulation from Hellman Avenue at Landerwood
- Visual Simulation from Huber Park
Regulatory Review Process
- SCE Notice of Application
- SCE Application for PTC
- Proponent’s Environmental Assessment – Volume 1
- Proponent’s Environmental Assessment – Volume 2
- Proponent’s Environmental Assessment – Volume 3
- Proponent’s Environmental Assessment – Volume 4
- Proponent’s Environmental Assessment – Volume 5
- Proponent’s Environmental Assessment – Volume 6
- CPUC Transmission Siting Process