The Proposed Action would include: 1) reconductoring the existing single- and double-circuit, 230-kV transmission line from the Elverta Substation to the Tracy Substation; 2) constructing a new double-circuit, 230-kV transmission line paralleling the existing double-circuit, 230-kV line from the O’Banion Substation to the Elverta Substation; and 3) realigning portions of the existing Cottonwood–Roseville single-circuit, 230-kV transmission line north of Elverta Substation. A detailed description of the Proposed Action is presented below:
Western would reconductor 72.6 miles of single- and double-circuit, 230-kV transmission lines between Elverta Substation and Tracy Substation. Reconductoring would be completed in two phases to minimize service disruption. The first 11.2 miles would be a double-circuit, 230-kV transmission line between Elverta Substation and Hurley Substation. The second 61.4-miles between Hurley Substation and Tracy Substation would include a combination of either two single- or one double-circuit transmission line. From Hurley Substation to Hedge Substation, there would be one double-circuit, 230-kV transmission line. Hedge Substation to Tracy Substation would include a combination of either two single-circuit, 230-kV transmission lines, or one double-circuit, 230-kV transmission line. Western would improve the fiber-optic communication system where necessary, replacing one of the two existing shield wires with a fiber-optic cable.
Western would construct a new, 26.6-mile, double-circuit, 230-kV transmission line between O’Banion Substation and Elverta Substation. It would parallel the existing O’Banion–Elverta double-circuit transmission line. This action would require a new right-of-way (ROW) (125 feet wide) for the transmission line. Additional access roads (15 feet wide) may be required.
Realignments are proposed for two locations. Realignment is defined as a route deviation of an existing transmission line. The route deviation would be sited outside of the existing ROW. The purpose for the realignments would be to reduce impacts to land use. One realignment for the Proposed Action would call for the construction of a new transmission line (2.8 miles) parallel to the existing O’Banion–Elverta transmission line, approximately 17 miles southeast of the O’Banion Substation. The realignment would avoid encroachment to the Pleasant Grove Cemetery. Conductors for the existing O’Banion–Elverta transmission line would be transferred to the west on 14 proposed new structures. The proposed new conductors would be strung along the existing structures to the east. This would avoid transmission line conductors crossing one another.
Western currently operates two transmission lines (2.8 miles) in adjacent ROWs (O’Banion–Elverta double-circuit, 230-kV line and Cottonwood–Roseville single- circuit, 230-kV line) between Keys Road and Elverta Substation. The total width of the two adjacent ROWs is 225 feet. There is no space to expand the ROW to add a third transmission line without impacting residences. Due to these ROW constraints, Western would realign five miles of the Cottonwood–Roseville single-circuit, 230-kV transmission line. A new transmission line between Keys Road and Elverta Substation would be constructed in place of the realigned Cottonwood–Roseville line. The realignment would deviate from the existing Cottonwood–Roseville transmission line at Keys Road and traverse eastward approximately 1.7 miles using new 125-foot-wide ROW along the south side of Keys Road. There it would angle south, paralleling the west side of the existing Pacific Gas & Electric Company (PG&E) Rio Oso–Brighton double-circuit, 230-kV transmission line for 3.3 miles. At that point, it would rejoin the existing route of the single-circuit, 230-kV Cottonwood–Roseville transmission line. This would eliminate the need for two sections of the existing Cottonwood–Roseville transmission line that would be abandoned in place. These sections are approximately 1.4 miles and 2.2 miles in length.
Alternative 1 would reconductor 99.2 miles of single- and double-circuit, 230-kV transmission lines on 820 structures from O’Banion Substation to Tracy Substation. About 199 structures would be replaced. Work would occur in three phases: O’Banion Substation to Elverta Substation; then Elverta Substation to Hurley Substation; and finally, Hurley Substation to Tracy Substation. Reconductoring activities for Alternative 1 would be the same as reconductoring activities described for the Proposed Action. While Alternative 1 would provide relatively less voltage support and capacity than the other action alternatives, it would relieve the system especially during periods of high load demand.
Alternative 2 is identical to the new transmission line construction and realignment activities of the Proposed Action, including new ROW (125 feet wide) and access roads (15 feet wide). Alternative 2 includes new construction of 26.6 miles of double-circuit, 230-kV transmission line between O’Banion Substation and Elverta Substation and realigning 2.8 miles near the Pleasant Grove Cemetery and five miles of the Cottonwood–Roseville transmission line.
Alternative 2 would require an estimated 50.9 acres of new access roads. Both realignments are described in the Proposed Action. Alternative 2 would meet the Purpose and Need by providing new transmission line between O’Banion Substation and Elverta Substation, and by providing additional voltage support for the Sacramento Area. The new line would eliminate limitations on the flow of power (generation) to Sacramento during n-1 and n-2 contingencies.
Alternative 3 would require new construction of 46.2 miles of double-circuit, 230-kV transmission line from Elk Grove Substation to Tracy Substation. The route would parallel Western’s two existing transmission lines (Hurley–Tracy No. 1 and No. 2) to the west. A new 125-foot-wide ROW adjacent to existing transmission line ROWs would contain about 225 new structures. Alternative 3 would require an estimated 85.5 acres of access roads. Alternative 3 would meet the Purpose and Need by supporting the load and thus increasing voltage support to the Sacramento area.
The No Action Alternative would include operating and maintaining the existing transmission lines. Western would not build or reconductor any transmission lines in the study area relative to voltage support. Implementing this alternative would preclude most short-term environmental impacts associated with construction and reconductoring activities.
This alternative would not meet Western’s Purpose and Need. Western may be unable to meet system reliability standards and its contractual obligations.