VI. Environmental Impacts of the Tehachapi-Vincent Transmission Project and Route Alternatives
The Final EIR 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 found that the proposed project would have significant unmitigable impacts on visual resources, land use and public recreation, agricultural resources, population and housing, noise levels, and air quality.
The conclusions in the Final EIR 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, will be implemented. The applicable APMs and Final EIR 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 as if fully set forth herein. Implementation of all of the applicable APMs and all mitigation measures recommended in the Final EIR 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 can be found at pages ES22 to ES-28 of the Final EIR. A detailed issue area by issue area comparison, running over 350 pages in length, can be found in Section C of the Final EIR.
In describing the 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 or reduce to less-than-significant levels other adverse environmental impacts of the Tehachapi-Vincent Transmission Project of the project that were determined to be significant but mitigable to less than significant (Class II) 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 is set forth in the CEQA Findings of Fact included in Attachment B.
A. Impacts on Visual Resources
The proposed project would begin near the Tehachapi Wind Resource Area in the Tehachapi Mountain Range west of the town of Mojave which is in the Mojave Desert. The project would cross the Pacific Crest National Scenic Trail in the Tehachapi Wind Resource Area. Two new substations (No. 2 and No. 1) would be constructed in this vicinity of hundreds of wind turbine generators. The project would proceed south from new Substation One, across the high desert plain of the Antelope Valley to the Antelope Substation, located at the western edge of the City of Lancaster, then would cross the rolling hills of Portal Ridge, across the San Andreas Rift Zone, and proceed across the steep mountains of the Sierra Pelona Ridge, and terminate at the Vincent Substation, south of the City of Palmdale and near Acton in unincorporated Los Angeles County. Such varied terrain and landscape characteristics are accompanied by many potentially sensitive viewing opportunities by residents, agricultural workers, and recreational travelers on local roads, and back-country recreationists, including hikers and equestrians.
The Final EIR, at pages C.11-1 through C.11-74, 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-1f, V-5, V-9, V-15 and V-16a through V-16d, all of which are fully set forth in Attachment A.
Notwithstanding the implementation of these mitigation measures, the Final EIR reports that the proposed project would have an unmitigable significant impact (Class I) on visual resources along one portion of the proposed route, along Elizabeth Lake Road, from Mile S2-6.7 to Mile S2-7.9 of the project route. From a strictly visual resource perspective and as seen from this nearby road, construction of new 500-kV lattice steel towers and conductors would create moderate visual contrast, because the existing transmission lines have created visual contrasts and clutter in the Midway-Vincent ROW. However, because three existing inhabited residences would be removed along this portion of the proposed route, the visual impact is high for all accounts. The view from these sensitive receptor locations would be permanently disrupted and the viewer platforms would be removed. The proposed project would add visual clutter and industrial character to this pastoral landscape, but more importantly, the proposed alignment would eliminate three existing houses from three different ranchettes, creating high visual contrast, dominance, and view blockage, as well as land use impacts and increase of industrial character.
However, the selection of Option A would mitigate these otherwise significant, unavoidable adverse visual impacts to a level of insignificance. Option A would be sited approximately 1,000 feet east of the proposed project alignment from approximately Mile S2-5.7 to Mile S2-7.7, and therefore would be located away from three existing residences located along Elizabeth Lake Road. The effect of implementing Option A would be that three existing houses would remain in a pastoral setting. Under Option A, the transmission line would be completely screened by landforms and would be located 1,000 feet farther away from the key observation position where the unmitigable significant visual impacts would otherwise occur; thus, the transmission line would not be visible from Elizabeth Lake Road or residences along both sides of Elizabeth Lake Road. This landform screening would also prevent viewers from seeing the transmission line from any other locations. No recreational resources or sensitive receptors would be traversed by the approximately 2.1-mile portion of Option A that deviates from the proposed project route.
For these reasons, Option A is the preferable route from the standpoint of mitigating the potentially significant and significant visual impacts of the proposed project.
B. Land Use and Public Recreation/Population and Housing
The Final EIR reports that the proposed project would have certain unmitigable significant impacts on land use and public recreation. The Final EIR, at pages C.8-1 through C.8-23, provides a discussion of the potential effects the proposed project and alternatives would have on existing and proposed land uses in addition to sensitive land uses that have the potential to be affected by the proposed project and alternatives. Also, at pages C.13-1 through C.13-10, the Final EIR provides a discussion of the potential effects the proposed project and alternatives would have on existing population and housing. Various mitigation measures have been proposed to address the potentially significant and significant impacts of the proposed project and its alternatives on land use and public recreation. These include measures L-1a through L-1c, L-5, N-3a and N-3b, all of which are fully set forth in Attachment A.
Notwithstanding the implementation of these mitigation measures, the Final EIR reports that the proposed project could have an unmitigable significant impact (Class I) on existing land uses, in that (1) the proposed project route and various alternatives would require the displacement of existing residences; (2) the selection of Option B or Alternative 3 would adversely impact planned development within Ritter Ranch and Anaverde Ranch; and (3) the selection of Option B or Alternative 3 would preclude the development of a planned school.
The proposed project would require an easement that would vary in width from 160 feet (Mile S3-0.0 to S3-9.6), to 180 feet (Mile S3-33.4 to S3-35.2, Mile S2-0.0 to S2-8.1, Mile S2-10.6 to S2-21.6), to 200 feet (Mile S3-9.6 to S3-33.4, Mile S2-8.1 to S2-10.6). This easement would extend over privately owned parcels and would restrict future use of the property within the proposed easement; the removal of some existing structures would be required and no new structures would be permitted within the easement during project operation. Of particular concern, the proposed easement would traverse a minimum of three existing residences in unincorporated Los Angeles County along Cherry Tree Lane (Mile S2-7.4), and would require the displacement and relocation of these residences for construction and operation of the project.
Moreover, in addition to the residential structures identified within SCE's proposed route that would need to be removed, both Alternatives 1 and 2 would require additional existing residential housing be removed. Specifically, Alternative 1 would require the removal of three single-family residences (ranchettes with horse stables) two of which are located west of the proposed Alternative 1 ROW and one of which is located east of the proposed Alternative 1 ROW on Cameron Canyon Road in unincorporated Kern County.
Alternative 2 would require several existing residences to be removed: a single-family residence at 10085 Hamilton Road, in unincorporated Kern County, and a number of single-family residences at 100th Street West, in unincorporated Kern County (on the east Side, 2 homes north of Rosamond Boulevard, 16 homes north of Avenue A and 1 home north of Avenue B, and on the west Side, several homes along Leslie Ave off 100th Street West and 6 homes north of Avenue A).
The removal of existing residences and/or the restriction of current or future land uses on private property is considered a significant and unavoidable impact (Class I).
The unavoidable significant impact of SCE's proposed project route can be avoided with a re-route around the residences along Cherry Tree Lane, such as the routes presented in Option A and in Alternative 4. Moreover, the unavoidable significant impact of removing existing residences under Alternative 1 or Alternative 2 can be avoided by not selecting either of those alternatives. Thus, the selection of Option A would avoid this otherwise unavoidable adverse impact on existing residences.
For the foregoing reasons, Option A is the preferable route from the standpoint of mitigating the potentially significant and significant impacts of the proposed project on existing housing.
Implementation of either Option B or Alternative 3 would preclude planned development within portions of Ritter Ranch and Anaverde Ranch. Both Option B and Alternative 3 would travel across the Ritter Ranch and Anaverde Ranch developments for which home sites, parks, open space areas and other facilities have been planned. Thus, construction and operation of Option B or Alternative 3 would preclude the use of land parcels within the 180-foot expanded ROW that have already been approved as future residential sites.
Proposed Mitigation Measure L-3 would minimize the effects of Option B and Alternative 3 to planned development at Ritter Ranch and Anaverde Ranch. However, the coordination with Ritter Ranch and Anaverde Ranch called for under this mitigation measure may not avoid impacts to planned residential development, and as such, the impacts of Option B and Alternative 3 on this planned development would be significant and unavoidable (Class I).
Neither the proposed project route nor Option A would traverse planned residential development within Ritter Ranch and Anaverde Ranch. Thus, the selection of SCE's proposed route or Option A will avoid this otherwise unavoidable adverse impact on planned residential development within Ritter Ranch or Anaverde Ranch.
For the foregoing reasons, either SCE's proposed route or the proposed route as modified by Option A is the preferable route from the standpoint of mitigating the potentially significant and significant impacts of the proposed project on planned residential development within Ritter Ranch and Anaverde Ranch, and both Option B and Alternative 3 are the least preferable alternatives.
Option B and Alternative 3 would travel across the Ritter Ranch and Anaverde Ranch developments. Both of these routes would restrict the use of proposed school sites in both Ritter Ranch and Anaverde Ranch, and would therefore affect the screening process required by the California Department of Education for the selection of new school sites proposed for development.
Proposed Mitigation Measure L-3 would minimize the effects of Option B and Alternative 3 to planned school site development at Ritter Ranch and Anaverde Ranch. However, the coordination with Ritter Ranch and Anaverde Ranch called for under this mitigation measure may not avoid impacts to planned school site development, and as such, the impacts of Option B and Alternative 3 on this planned school site development would be significant and unavoidable (Class I).
However, neither the proposed project route nor Option A would traverse planned school site development within Ritter Ranch and Anaverde Ranch. Thus, the selection of SCE's proposed route or Option A will avoid this otherwise unavoidable adverse impact on planned school site development within Ritter Ranch or Anaverde Ranch.
For the foregoing reasons, either SCE's proposed route or Option A is the preferable route from the standpoint of mitigating the potentially significant and significant impacts of the proposed project on planned school site development within Ritter Ranch and Anaverde Ranch, and both Option B and Alternative 3 are the least preferable alternatives.
C. Agricultural Resources
The proposed Project would construct lattice steel towers and new access and spur roads across lands classified as Prime Agricultural Land and Mixed Acreage Parcels under the California Land Conservation Act of 1965 (Williamson Act). More specifically, Segment 3 of the proposed project would involve the siting of the 20.2-acre Substation Two on Mixed Acreage Parcels.
The Final EIR, at pages C.9-1 through C.9-24, provides a detailed discussion of the potential effects the proposed project would have on agricultural resources. This discussion includes a number of detailed maps. Several mitigation measures have been proposed to address the potentially significant and significant impacts of the proposed project and its alternatives on agricultural resources. These include measures AG-3, AG-4 and N-3a, all of which are fully set forth in Attachment A.
Notwithstanding the implementation of these mitigation measures, the Final EIR reports that the proposed project could have an unmitigable significant impact (Class I) on land that is currently the subject of a contract under the Williamson Act. In total, operation of the proposed project (i.e., tower footings, access and spur roads, substation pad) would permanently remove approximately 1.0 acre of Prime Agricultural Land and 28.6 acres of Mixed Acreage Parcels. Given that Mixed Acreage Parcels include Prime Agricultural Land in addition to Non-Prime Williamson Act lands, the total amount of Prime Agricultural Land that would be permanently disturbed may exceed the 10 acres for Prime Farmland that has been established as the threshold level of significance for conflicting with a Williamson Act contract, thereby resulting in significant and unavoidable impacts (Class I).
This impact can only be avoided with a relocation of proposed Substation Two, such as the alternative Substation 2C site that has been proposed as part of Alternative 1.
For this reason, Alternative 1 the preferable route from the standpoint of mitigating the potentially significant and significant impacts of the proposed project on agricultural resources, specifically, lands under a Williamson Act contract.
D. Noise
The Final EIR reports that noise associated with the operation of the proposed project would violate local noise standards and that permanent noise levels along the project ROW would increase due to corona noise from the operation of the transmission lines. The Final EIR, at pages C.10-1 through C.10-22, describes the various noise impacts of the proposed project. Several mitigation measures have been proposed to address the potentially significant and significant noise impacts of the proposed project and its alternatives. These include measures N-1, N-3a and N-3b, all of which are fully set forth in Attachment A.
Sensitive noise receptors are located along the proposed project route, immediately adjacent to the proposed transmission ROW (within 0.2 miles), as well as along the proposed alternative routes. The most stringent land use noise standards of all the local jurisdictions in the project area are included within the Los Angeles County Noise Ordinance, which contains a noise standard of 45 dBA for noise-sensitive areas such as residential land uses along the route within Los Angeles County. The level of worst-case wet weather and heavy load noise would likely be between 55 and 65 dBA along the corridor. Therefore, operational corona noise levels at these locations would exceed Los Angeles County Ordinance Standards and would therefore result in a significant and unavoidable impact (Class I). No mitigation measures have been identified to reduce this impact.
Similarly, corona discharge associated with high-voltage power transmission lines is heard near an energized line as a crackling or hissing sound. SCE did not forecast a specific level of audible corona noise for the proposed transmission line. According to SCE, the wet-conductor generated acoustic power (dB) of a single circuit 500 kV transmission line (baseline) is calculated to be 55.9 dB, at the edge of the ROW. The dB level with the addition of another parallel 500 kV transmission line is calculated to be 57.0 dB, at the edge of the ROW. The heavy-rain generated acoustic power (dB) of a single circuit 500 kV transmission line (baseline) is calculated to be 62.0 dB, at the edge of the ROW, with an increase to 63.1 dB at the edge of the ROW with the addition of another parallel 500 kV transmission line. Corona noise would occur along the entire corridor of SCE's proposed route as well as the alternative routes, all of which are, along certain lengths of their respective routes, in close proximity to sensitive receptors. Thus, the proposed project, under any of the alternatives studied, would create ambient noise levels greater than the noise occurring under existing conditions. This would cause significant operational noise impacts to adjacent sensitive uses. The level of worst-case wet weather and heavy load noise would likely be between 55 and 65 dBA along the corridor, meaning that introduction of new corona noise could result in a substantial (more than five dBA) increase to the ambient noise levels of nearby receptors. For any homes or other sensitive receptor within about 200 feet of the ROW, this would violate local standards or policies. This increase in ambient noise levels to sensitive receptors immediately adjacent to the proposed ROW would constitute a significant and unavoidable (Class I) impact.
No mitigation measures have been identified that would reduce these noise impacts to a less-than-significant level. Moreover, there are sensitive receptors located nearby to SCE's proposed route as well as nearby to all of the alternative routes studied in the Final EIR. Consequently, there would be significant and unavoidable noise impacts under all alternatives, and none of the alternatives studied would be preferable from the standpoint of mitigating such impacts.
E. Air Quality
The Final EIR reports that essentially all air quality impacts associated with the proposed project would occur during project construction. The Final EIR, at pages C.2-1 through C.2-25, describes expected dust and exhaust emissions during construction of the proposed project. Construction is tentatively scheduled for March 2008 to June 2009. Temporary construction emissions would result from on-site activities, such as surface clearing, excavation, foundation construction, steel construction, etc.; and from off-site activities such as construction-related haul trips and construction worker commuting. Pollutant emissions would vary from day to day depending on the level of activity, the specific operations, and the prevailing weather.
Most of these identified impacts can be mitigated to a level of insignificance by the adoption and implementation of mitigation measures A-1a through A-1i, all of which are fully set forth in Attachment A.
However, even with all recommended mitigation measures, dust and exhaust emissions during construction would still exceed the regional emission thresholds of the Antelope Valley Air Quality Management District (AVAQMD). Accordingly, the Final EIR reports that, even with the recommended mitigation measures, the proposed project would cause significant and unavoidable (Class I) impacts in that construction emissions would exceed daily regional emission thresholds in the AVAQMD.
No mitigation measures have been identified that would reduce these air quality impacts to a less-than-significant level. Moreover, there would be essentially identical impacts in connection with all of the alternative routes studied in the Final EIR. Consequently, there would be significant and unavoidable air quality impacts under all alternatives, and none of the alternatives studied would be preferable from the standpoint of mitigating such impacts.
