4. Proposed Facilities Description

By this application, SCE seeks authority to build the Leatherneck Substation project, which includes:

_ Leatherneck Substation: Construction of a new, customer-dedicated, 115/33kV substation, located within the USMC Combat Center and encompassing an inside-the-fence area of approximately 0.9 acres. Including the access driveway and drainage and slope improvements outside the fence, the new Leatherneck Substation will cover a total area of approximately 1.9 acres. The Leatherneck Substation will be connected to both the existing Hi Desert Substation and the existing Carodean Substation, as described in the following paragraphs.

_ Hi Desert-Leatherneck Subtransmission Line: The subtransmission connection to the new Leatherneck Substation from Hi Desert Substation will consist partly of new line and partly of reconfigured existing line.

_ Carodean-Leatherneck Subtransmission Line: Construction of a new 115kV subtransmission line from the existing Carodean Substation to the new Leatherneck Substation, a distance of approximately 9 miles, by overbuilding existing 33kV circuit and existing 12kV circuit along that route.

_ Carodean-Hi Desert Subtransmission Line: A new 115 kV line segment will be overbuilt along the existing 33kV route from Hi Desert Substation to Sunnyslope Drive, a distance of approximately 1 mile which will connect at Sunnyslope Drive to the existing 115 kV line to Carodean Substation, together forming the new Carodean-Hi Desert 115 kV line.

_ Upgrades to and expansion of the existing Hi Desert Substation: Electrical reconfiguration of the Hi Desert Substation, including expansion of the overall substation site by approximately 28 feet to the north (an expansion area of approximately 0.2 acres) on SCE-owned property.

_ Upgrades to additional existing SCE substations: Electrical reconfiguration of the Carodean Substation, including construction of a new mechanical electrical equipment room, but not involving any expansion of the overall substation site; and electrical equipment upgrades at the Yucca and Devers substations, also not involving any expansion of the substation sites.

_ Telecommunications Equipment: Installation of new telecommunications equipment and new overhead fiber optic lines at the new Leatherneck Substation as well as at the existing substations.