5. Discussion

5.1. Overview

D.08-12-031 summarizes all aspects of the Commission's review and approval of the El Casco Project and its grant of a PTC for the project. Before us now is SCE's request that we modify D.08-12-031 to authorize certain design changes within Segments 2 and 4 of the approved project. Also before us is the Supplemental Final EIR, which incorporates the Supplemental Draft EIR and reviews the potential environmental impacts of the proposed design changes.

As discussed in greater detail below, the Supplemental Final EIR determines that the design changes within Segments 2 and 4 result in environmental impacts in the area of visual resources. The proposed changes increase the visual impacts of the project both during construction and afterward, and result in certain significant and unavoidable impacts because those impacts cannot be mitigated to a less than significant level. In addition, several visual impacts contribute to a cumulative impact that cannot be mitigated to a less than significant level. The changes proposed do not result in a substantial change to the impacts previously identified in other resource areas or create new impacts in those areas.

As also discussed below, the changes do not alter D.08-12-031's assessment of the greenhouse gas (GHG) impacts of the project or its EMF implications.

5.2. Visual Resources

The Supplemental Final EIR identifies and analyzes two types of visual impacts along Segments 2 and 4: construction impacts and impacts associated with project operation. The Supplemental Final EIR also performs a cumulative impact analysis of these visual impacts.

Mitigation can reduce all construction-related visual impacts to less than significant levels. These impacts comprise the kind of impacts that result from the presence and visual intrusion of construction vehicles, equipment, material, and work force at the construction and staging areas, as well as impacts attributable to land scarring at those sites. Mitigation for the former includes specific measures to reduce visibility of construction activities and equipment and to reduce construction night lighting. Mitigation of the latter includes reducing in-line views of land scars and reducing the visual contrast of unnatural vegetation lines.

Some visual impacts in Segments 2 and 4 associated with post-construction project operation do not rise to significant levels, but several will be significant and unavoidable. Based upon assessments from key viewpoints identified along the subtransmission line's route, these operational visual impacts occur because of a visual increase in structure contrast, industrial character, view blockage, skylining (defined as an extension above the horizon line), and glare. The Supplemental Final EIR determines that no feasible mitigation is available to reduce these operational visual impacts along Segment 2 (viewed from Key Viewpoint 1 on South Sunset Avenue) and along part of Segment 4 (viewed from Key Viewpoint 2 on Faircliff Street). The visual impact elsewhere along Segment 4 (viewed from Key Viewpoint 3 on southbound State Route 79) is adverse but less than significant, which does not require mitigation.

5.3. Other Resource Areas and GHG Emissions

The Supplemental Final EIR also re-evaluates the impact of the proposed changes to the project on the following issue areas: air quality (Impact AQ-3 specifically addresses GHG emissions); land use; biological resources; cultural resources; geology and soils; hazards and hazardous materials; hydrology and water quality; noise; public services and utilities; and transportation. The Supplemental Final EIR determines that no additional impacts or new impacts would result in these areas. With respect to GHG emissions, since the design changes do not introduce more electrical switchgear equipment or circuit breakers, which generate the GHG sulfur hexafluoride (SF₆), the Supplemental Final EIR determines that the proposed changes to the project create no new, or substantially more severe, climate change impacts.

5.4. EMFs

Because CEQA does not define or adopt any standards to address the potential health risk impacts of possible exposure to EMFs, the Commission does not consider EMF issues in the context of CEQA. However, the Commission's GO 131-D, Section X, requires that PTC applications include a description of the measures undertaken or proposed to reduce the potential for exposure to any project-generated EMFs. D.08-12-031 discusses SCE's proposed EMF mitigation measures and finds that they comply with the Commission's "no-cost, low-cost" interim EMF reduction policy.

The proposed changes to the project should not increase EMF impacts and actually may lessen them. The two major features of the changed design - taller poles at some locations, and at others, a greater number of poles, which will reduce line sag-will both raise the energized subtransmission line further above ground level.

SCE has not asked the Commission to revise the EMF mitigations D.08-12-031 orders and, on the record developed here, we have no independent reason to do so. Therefore, approval of the proposed changes to the project should require continued compliance with all EMF mitigation D.08-12-031 requires.