Transmission Line Undergrounding and Removal

In addition to the replacement of the substation, SDG&E also proposes other changes. Currently, there are three overhead 138kV transmission lines running from the South Bay Power Plant Switchyard on shared structures. Two of those lines connect into the Main Street Substation, while the third line (Tie Line 13815) bypasses the Main Street Substation, and continues on to SDG&E's Mission Substation. (Yari, Transcript, pp. 67-68.)

SDG&E proposes to remove the two lines that currently serve the Main Street Substation, and underground the third line (Tie Line 13815) for approximately 2.5 miles, from the South Bay Power Plant Switchyard to the Sweetwater River, in the City of Chula Vista. This would also allow for the removal of 18 steel lattice towers. Other than the undergrounded portion, Tie Line 13815 would remain in its existing route and configuration.

The City of Chula Vista strongly supports SDG&E's proposal to remove and underground the existing overhead transmission lines in Chula Vista. (Exhibit 6; see also PPH Transcript, pp. 2-6.)

Rohr, Inc., operating as Goodrich Aerostructures Group (Rohr), filed a protest to SDG&E's Application, arguing that the portion of the project proposing the undergrounding of transmission lines on the existing transmission easement on Rohr's property could have adverse environmental and economic impacts on Rohr and its facilities and business operations. Specifically, Rohr argued that the undergrounding of the transmission lines could result in changes in groundwater flow and the movement and concentration of contaminants, and subsidence that could affect Rohr buildings and equipment. In addition, the construction of the underground transmission line on Rohr's property could disrupt or interfere with Rohr's business operations. (Rohr Protest, pp. 2-8.)

The environmental issues raised by Rohr's protest were addressed in the CEQA review process leading to the Final EIR we adopt today, and are discussed further in the draft and final EIRs. Rohr requested evidentiary hearings, but other than filing a protest and appearing at the prehearing conference, Rohr has not participated in this proceeding. Rohr did not attend the public participation hearing nor the evidentiary hearing, both of which were held in the San Diego area.

According to SDG&E, Rohr and SDG&E have reached an agreement or understanding that has resolved their differences, and Rohr has agreed to SDG&E's trenching across Rohr's property. (Yari, supra, Transcript p. 69.) Rohr was concerned about SDG&E trenching across its property multiple times, as both the Silvergate and Otay Mesa Projects involve undergrounding of transmission facilities on Rohr's property. As its part of the agreement or understanding, SDG&E is supposed to only trench across Rohr's property once, combining the construction process for the undergrounding of the Silvergate 138 kV line and the installation of the Otay Mesa 230 kV line. (Id.) Combining the construction of the Silvergate and Otay Mesa transmission lines makes sense as a way to minimize the environmental and economic impacts of the construction, and should also reduce the cost of construction. We order SDG&E to combine construction of the Silvergate and Otay Mesa Projects to the extent possible, particularly the undergrounding of transmission lines.

Given the mitigation measures adopted in the Final EIR relating to the environmental issues raised by Rohr, SDG&E's statement under oath that SDG&E and Rohr have resolved their differences, and Rohr's lack of participation in the proceeding,⁶ we find that the issues raised by Rohr's protest are no longer contested.

We approve SDG&E's request to remove the two 138 kV lines connecting the South Bay Power Plant Switchyard and the Main Street Substation, and to partially underground a third 138 kV line (Tie Line 13815) in the City of Chula Vista.

⁶ We conclude that Rohr's lack of participation is intentional, rather than inadvertent, as Rohr is a large and sophisticated business, and is represented in this proceeding by counsel with extensive experience litigating before this Commission.