VII. Environmental Impacts of the Antelope-Pardee Transmission Project and Route Alternatives

The Final EIR/EIS evaluated the environmental impacts of the proposed project and alternatives, classifying the impacts as Class I (significant and unavoidable or unmitigable), Class II (significant but mitigable to less than significant), Class III (adverse but less than significant), and Class IV (beneficial). The Final EIR/EIS found that the proposed project would have significant unmitigable impacts on visual resources, forest management activities, land use and public recreation, socioeconomics, noise levels, and air quality.

The conclusions in the Final EIR/EIS regarding environmental impacts of the proposed project and its alternatives assume that the impact-reduction measures proposed by SCE in the PEA, called Applicant Proposed Measures or APMs, together with the additional mitigation measures recommended in the Final EIR/EIS, will be implemented. The applicable APMs and Final EIR/EIS mitigation measures for the proposed Project are included as part of this Decision in Attachment A. We adopt the mitigation measures included in Attachment A, including the Applicant Proposed Measures, as if fully set forth herein. Implementation of all of the applicable APMs and all mitigation measures recommended in the Final EIR/EIS is a condition of our approval of this project.

A summary comparison of the project as proposed by SCE and the alternatives that were studied in detail in the Final EIR/EIS can be found at pages ES19 to ES-27 of the Final EIR/EIS. A detailed issue area by issue area comparison, running over seven hundred pages in length, can be found in Section C of the Final EIR/EIS.

In describing potential environmental impacts of the proposed project below, we focus on the significant unmitigable (Class I) impacts, since we expect that the adopted mitigation measures will eliminate other potentially adverse environmental impacts of Antelope-Pardee Transmission Project or allow them to be reduced to less-than-significant levels. Accordingly, the description below does not include any detailed discussion of those issue areas for which all identified significant or potentially significant environmental impacts can be mitigated to a level of insignificance by implementation of the mitigation measures set forth in Attachment A. A more detailed discussion of all identified significant or potentially significant environmental impacts of the proposed project and the alternative routes studied in the Final EIR/EIS is set forth in the CEQA Findings of Fact included in Attachment B.

A. Impacts on Visual Resources

The proposed Project would remove a portion of an existing 66 kV transmission line that was constructed in the 1930s, and would replace it with a new 500-kV transmission line in the same right-of-way from Mile 1.1 to 18.6. A new ROW would be established from Antelope Substation to the existing 66-kV line (Mile 0.0 to approximately 1.1), and also in Haskell Canyon from Mile 18.6 to Mile 20.3. Beyond Mile 18.6, the existing 66-kV transmission line would remain in its current location. The proposed project would expand the existing transmission corridor by an additional 60 feet for a total corridor width of 160 feet. The height of the new lattice steel towers would range between 38 feet to 118 feet taller than the existing towers (178 feet), and the tower arms would be approximately 80 feet wider than the existing tower arms. The towers would be prominent visual features of the landscape.

The Final EIR/EIS reports that the proposed project could have numerous unmitigable significant impacts on visual resources. Of all the issue areas studied in the Final EIR/EIS, visual resources is the topic with, by far, the largest number of potentially significant unmitigable impacts. The Final EIR/EIS, at pages C.15-1 through C.15-217, provides a detailed discussion of the potential effects the proposed project and alternatives could have on visual resources as well as numerous photographic visual simulations.

An extensive set of mitigation measures has been proposed to address the potentially significant and significant visual impacts of the proposed project and its alternatives. These include measures V-1a through V-1e, V-3a through V-3c, V-4a through V-4c, V-12, V-15a through V-15c, V-16a through V-16c, V-17a through V-17d, B-1a, B-1b and R-4 (see, pages A-23 and A-26 to A-28 of Attachment A).

Because of the complexity of the visual impacts of the proposed project and its alternatives, the discussion below begins with a discussion of construction impacts, which apply to all alternatives, and is followed by a discussion of the visual impacts of the project and each of its alternatives in turn.