3. Summary of Environmental
Findings in D.12-04-022
3.1. Environmentally Superior
Project Alternative
The EIR/EIS, as certified by D.12-04-022, identifies the environmentally superior project alternative, other than the "no project" alternative, as the ECO Substation Alternative combined with the ECO Partial Underground 138 kV Transmission Route Alternative, Tule Wind Alternative 5 (reduction in turbines) combined with Tule Wind Alternative 2 (underground the 138 kV transmission line from the operations and maintenance and collector substation facilities co-located on Rough Acres Ranch), and the Energy Sierra Juarez (ESJ) Gen-Tie Overhead Alternative Alignment.
The approved ECO Substation Alternative Site would avoid a significant prehistoric archeological site, thus avoiding the significant impacts that the substation site proposed by SDG&E would have on prehistoric archaeological resources. Whereas SDG&E proposed building the entire 138 kV transmission line above ground, the approved ECO Partial Underground 138 kV Transmission Route Alternative would underground two portions of the line for environmental reasons. One portion of the alternative, in which the line would be rerouted and undergrounded along existing roadways between Mile Point (MP) 0.3 and MP 2.4, was developed as a result of consultation under Section 106 of the Historic Preservation Act to reduce cultural resource impacts. The second portion would underground the line between MP 9 and the rebuilt Boulevard substation, to minimize visual impacts to residents of the community of Boulevard. Undergrounding these two portions of the line also would minimize visual impacts at several scenic vistas. The potential for ignition of wildfires would be reduced and significant impacts on the effectiveness of firefighting would be avoided along the undergrounded portions of the line, compared to above-ground construction.
The EIR/EIS identified mitigation measures that would eliminate or lessen the project's adverse environmental impact; those measures are identified in the Mitigation Monitoring, Compliance and Reporting Plan (MMCRP) attached to this order. The EIR/EIS determines that, notwithstanding these mitigation measures, the environmentally superior project alternative will have the following significant and unmitigable adverse impacts.
3.2. Unmitigable Adverse Impacts
The ECO Substation Alternative combined with the ECO Partial Underground 138 kV Transmission Route Alternative would have significant adverse and unmitigable impacts on Quino checkerspot butterfly critical habitat. Quino checkerspot butterfly is a federally endangered species found only in western Riverside Country, southern San Diego County, and northern Baja California, Mexico. The substation would result in the permanent loss of 2.27 acres of U.S. Fish and Wildlife Service critical habitat for this species.
The Tule Wind Alternative 5 combined with Tule Wind Alternative 2 would have adverse and unmitigable impacts to birds, such as golden eagles, due to the risk of mortality from collision with operating wind turbines.
The ECO Substation Alternative combined with the ECO Partial Underground 138 kV Transmission Route Alternative would be located in a predominantly undeveloped desert landscape in eastern San Diego County, approximately 0.5 mile to the west of the Jacumba Mountains Wilderness, and approximately 0.7 mile to 1.5 miles south of the Table Mountain Area of Critical Environmental Concern (ACEC) and Anza-Borrego Desert State Park. The substation would be mainly visible by travelers and dispersed residences along Interstate 8 and Old Highway 80, and views would also be possible from the Jacumba Mountains Wilderness, the Table Mountain ACEC and other BLM-administered public lands, and would substantially degrade the area's existing visual character.
The Tule Wind Alternative 5 combined with Tule Wind Alternative 2 would have significant adverse and unmitigable impacts on visual resources. The proposed wind turbines and associated overhead and underground 34.5 kV collector cable systems would be situated in a natural, undeveloped desert landscape of eastern San Diego County in the In-Ko-Pah Mountains near the McCain Valley. The northern extent of the project area would be bordered by high mountainous terrain to the north, northwest, and east including the Sawtooth Mountains Wilderness Area to the north, the Laguna Mountains to the northwest, and Sombrero Peak to the northeast in Anza-Borrego Desert State Park. The wind turbines would be visually dominant and prominent against the skyline. The Tule Wind 138 kV transmission line would create significant impacts to scenic views where it would cross Interstate 8 and parallel and cross Old Highway 80 into the Boulevard Substation, and would introduce a moderate to strong industrial feature into a landscape characterized by a mixture of natural and rural community elements.
The ESJ Gen-Tie Overhead Alternative Alignment would be situated in a predominantly natural, undisturbed desert landscape in eastern San Diego County immediately south of the proposed ECO Substation. While the 500 kV or 230 kV gen-tie would not be openly visible or cause adverse visual impacts, the ESJ Phase 1 wind turbines to be located in Mexico would create strong, openly visible and sky-lined visual contrasts along the ridgeline and slopes of the Sierra de Juarez Mountains.
All components of the environmentally superior alternative would have potential adverse and unmitigable impacts to traditional cultural property (TCP). Although no TCPs have been identified, potential National Registry of Historic Places eligibility of unknown TCPs is assumed. In some cases, avoiding direct and indirect impacts to TCPs such as traditional landscapes, topographic elements including sacred mountains, or use areas may not be completely feasible. In this event, the impact on TCPs would be adverse and, while mitigation is provided, the impacts would not be mitigated to a level that is less than significant.
The ECO Substation Alternative combined with the ECO Partial Underground 138 kV Transmission Route Alternative and the Tule Wind Alternative 5 combined with Tule Wind Alternative 2 would have adverse and unmitigable noise impacts that would occur temporarily during construction due to construction-related nighttime noise, helicopters and blasting.
Construction of the ECO Substation Alternative combined with the ECO Partial Underground 138 kV Transmission Route Alternative will generate emissions of nitrogen oxides (NOx) and particulate matter less than or equal to 10 microns (PM10) in excess of the significance levels recommended by the San Diego Air Pollution Control District; construction of the Tule Wind Alternative 5 combined with Tule Wind Alternative 2 will generate volatile organic compounds (VOC), NOx, particulate matter less than or equal to 2.5 microns (PM2.5), and PM10 emissions in excess of the recommended significance levels; and construction of the ESJ Gen-Tie Overhead Alternative Alignment will generate PM10 emissions in excess of the recommended significance levels. Construction of all three projects in combination will generate carbon monoxide (CO) emissions, as well as emissions of NOx, VOC, PM10 and PM2.5, in excess of the recommended significance levels.
The ECO Substation overhead transmission lines increase the probability of a wildfire and reduce firefighting effectiveness. As part of the plan for mitigating these impacts, SDG&E is required to develop a fire protection plan for the ECO Substation, which will be subject to review and comment by responsible agencies and final approval by the lead agencies (Mitigation Measure FF-4), and to provide funding assistance to the San Diego Rural Fire Protection District (District) (as well as to the San Diego County Fire Authority) to support fire code specialist positions in an amount to be determined by the lead agencies (Mitigation Measure FF-3). Because the fire protection plan and funding assistance arrangements have yet to be approved by the lead agencies, the EIR/EIS states that the effectiveness of this mitigation in reducing these impacts "is not known and therefore, [the impacts are] considered unavoidable for purposes of the analysis conducted in this EIR/EIS." (Exhibit 11 at D.15-58 and D.15-68.)
