Discussion of the EIR

SDG&E's stated objectives for the OMPPA Transition Project are as follows:


2. Provide firm transmission delivery of OMGP to load centers at the Sycamore Canyon and Old Town substations, along with surrounding substations.


3. Prevent the OMGP from compounding intra-zonal congestion at the Miguel Substation.


4. Meet G-1/N-17 reliability need due to future load growth.


5. Provide for expansion capability for load growth and possible generation retirement.


6. Minimize load shedding and avoid potential cascading outage during Miguel Corridor outage.


7. Provide cost savings to SDG&E customers by reducing some of the CAISO reliability must run (RMR) contract requirements.

CEQA Guidelines 15123 requires the EIR summary to include "[a]reas of known controversy known to the lead agency including issues raised by agencies and the public." Known areas of controversy, which include issues raised during the public scoping process include: potential impacts on the human environment, especially with issues arising from above-ground transmission lines in Chula Vista and below-ground transmission lines in San Diego. Many commenters stated that Chula Vista has previously received a disproportionate amount of effects from existing electric lines. Other commenters focused on impacts to existing land use plans, visual and scenic impacts, health concerns related to increased electric and magnetic field (EMF) emissions, biological resources, public services and utility issues, traffic and noise.

CEQA requires that a reasonable range of project alternatives be discussed in the EIR. Section 15126.6[a] states:


An EIR shall describe a reasonable range of alternatives to the project, or the location of the project, which would feasibly attain most of the basic objectives of the project but would avoid or substantially lessen any of the significant effects of the project.

Following the guidelines, the alternatives were evaluated as to whether they would meet the project's objectives, be feasible and have the potential to substantially lessen any of the significant environmental impacts. The EIR identifies and analyzes such a reasonable range of alternatives; discusses the environmental effects of each alternative; compares the environmental effects of each alternative with the environmental setting, with the effects of each other alternative, and with the Proposed Project; and addresses the relationship of each alternative to the project objectives.

The alternatives considered and carried forward for full EIR evaluation:


1. Pacific Highway Bridge Attachment Design Alternative


Under this alternative, the 230 kV line cable would be attached to the Pacific Highway Bridge rather than directional drilled under the San Diego River as proposed in the OMPPA Project. This alternative met all the stated project objectives, was determined to be feasible and would lessen the environmental effects of the Proposed Project by avoiding potentially significant environmental impacts to soils, water resources and biological resources that could result from directional drilling under the San Diego River. Therefore, this alternative was carried forward for full analysis in the EIR.


2. Sicard Street Transition Cable Pole Design Alternative


Under this alternative, the cable pole design would be approximately 145 feet in height and would require a substantially smaller footprint for the single pole design as compared with the 230 kV transition station as proposed. This proposal met all the required criteria for an alternative to be carried forward to full analysis in the EIR.


3. Harbor Drive Bridge Cable Attachment Design Alternative


This is an alternative to boring under the Harbor Drive Bridge and instead the underground cable would emerge from its underground configuration and attach to the underside of the bridge at the south end and at the north end transition underground. This proposal met all the required criteria for an alternative to be carried forward to full analysis in the EIR.


4. South Bay Power Plant Area to Sweetwater River Overhead Design Alternative


This alternative would minimize the impacts to the Sweetwater Marsh National Wildlife Refuge because it eliminates boring under the Refuge and supports the two 230 kV lines above ground on the existing bridge structures in the Chula Vista Bayfront. While this alternative would minimize impacts to the Sweetwater Marsh Refuge, its ability to lessen environmental effects of the Proposed Project and legal/regulatory feasibility would depend on its compatibility with applicable land use plans and policies relevant to the City of Chula Vista Bayfront and on the regulatory feasibility due to coastal permit issues within the City of Chula Vista. Because this alternative would minimize impacts to Refuge, it was carried forward to full EIR analysis.

This alternative combines an existing 138 kV line with the new 230 kV line on one structure and eliminates existing lattice structures between Proctor Valley Substation to the South Bay Substation and it has the potential to avoid and minimize visual and land use impacts along almost the entire length of the proposed OMPPA Transmission Project in Chula Vista. This alternative would necessitate two actions: (1) installing the new 230 kV monopoles and 230 kV/138 kV conductors; and (2) dismantling and removing the existing 138 kV lattice structures and one of the 138 kV conductors. Under this alternative, one of the existing 138 kV conductors, currently on the lattice structure, would be relocated to the new monopoles, but the other 238 kV circuit would be removed.

By removing the lattice structures and installing the monopoles under this alternative, there would be a beneficial visual change, depending on viewer location and conditions that would range from beneficial to slightly adverse. The removal of the existing lattice towers would substantially reduce the visual effects of the addition of the proposed 230 kV monopoles. This alternative met all the required criteria to be carried forward to full analysis in the EIR.

Alternative 1 would require the construction of two 230 kV lines from the Miguel area with one line going to the Sycamore Canyon Substation and other to the Mission Substation. This alternative has the ability to bypass the Miguel Substation by the addition of 230 kV line tap breakers at the Miguel Substation. Although this alternative meets most of SDG&E's objectives and is feasible, it does not lessen any of the significant environmental effects of the Proposed Project, and in fact would create some additional environmental impacts.

This alternative builds on System Alternative 1 by adding a new 230 kV line between Otay Mesa Substation and the Miguel Substation. This alternative does not lessen any of the impacts of the Proposed Project and adds additional construction-related impacts to sensitive residential neighborhoods.

This alternative would entail the construction of two 230 kV lines from the Miguel Substation and a new 230 kV/138 kV/69 kV substation at the South Bay Power Plant. This alternative was rejected because it would not meet most of SDG&E's stated objectives.

This alternative would entail the construction of a new 230 kV line between the Miguel and Sycamore Canyon Substations. This alternative is feasible, but was rejected because it would not meet most of SDG&E's stated project objectives as it would not offer the full dispatchability and delivery of the OMPP.

This alternative is the same as System Alternative 5 which was the proposed OMPPA as presented in the May 2004 application, but also adds another new 230 kV line between the Otay Mesa Substation and the Miguel Substation. This alternative would meet stated objectives and potentially the feasibility criteria if the alternative were modified to be consistent with the Recent MOU with the City of Chula Vista. However, it would not avoid or lessen any significant impacts of the Project and would add new impacts between the Miguel and Otay Mesa Substations.

The DEIR details numerous other alternatives in the Alternatives Screening Report Appendix 2 that were considered, but rejected for full EIR evaluation. These options included the following: undergrounding, structure designs, use of Caltrans Bike Path/Railroad ROW/rerouting to avoid the Sweetwater Marsh, routing alternatives, repowering of South ay, and energy conservation, demand side management and renewables. The DEIR Alternatives Screening Report discusses in detail how these various alternatives comport, or do not comport, with SDG&E's stated objectives, are feasible or not, and whether they add to or reduce significant environmental impacts.

This alternative assumes that SDG&E would need to make other improvements elsewhere in their system to compensate for the system benefits that would not be realized under the No-Project scenario. There is the possibility that new generation capacity and/or transmission capacity could be necessary in San Diego County or elsewhere to compensate for existing system limitations and anticipated loads. The impacts of the No-Project alternative would primarily result from operation of gas fired turbine generators and/or development of new transmission. Long term operational impacts from generation would include air emissions and noise as well as visual impacts. Impacts from new transmission facilities would primarily be the same as those of the Proposed Project with the exception of land use and visual, which could be greater if developed within a new transmission corridor.

6 On June 9, 2004,in D.04-06-011, the Commission approved a 10-year Power Purchase Agreement (PPA) between SDG&E and Calpine as part of the approval of a number of resources that were evaluated as part of SDG&E's 2004 Request For Proposal (RFP) for a mix of resources to meet its grid reliability needs. There are pending applications for rehearing of D.04-06-011, filed jointly by TURN and The Utility Consumers Action Network, the Alliance for Retail Energy Markets and Chula Vista. Our discussion of this decision is not intended to dispose of or prejudice the pending rehearing applications. 7 The G-1/N-1 criterion is defined as loss of the largest generating unit with operating adjustments to prepare the system for another contingency, followed by the worst transmission outage. In SDG&E's case, the worst G-1/N-1 that defines its reliability requirements is the overlapping outage of the Encina five unit plus loss of the Southwest power link.

Previous PageTop Of PageNext PageGo To First Page