6. Results of Environmental Analysis
As required by CEQA, the FEIR presents conclusions regarding the environmentally superior alternative for each project component. This comparison is based on the environmental impacts of PG&E's proposed project and each alternative, as identified in Exhibit 1000, Sections C.2 through C.13, and as modified and further evaluated in Section C and H of Exhibit 1003. CEQA requires that, if the No Project Alternative is found to be environmentally superior, the EIR also identify the environmentally superior "build" alternative for the consideration of decision makers. Alternatives are compared by summarizing the impacts of each alternative in each environmental issue area, considering the relative importance of the issues, and then identifying the alternative with the least overall impact on the environment. Exhibit 1003, Section D, presents summary tables for each alternative.
The FEIR found two alternatives in the Pleasanton area to be environmentally superior to other alternatives and the proposed project. As described in Exhibit 1003 and 1003-A, the FEIR finds that the combinations of S2A/S2 and S2A/S2/S5 to be environmentally superior. Because each of these routes utilizes a combination of the Pleasanton alternatives, and because variants for S2A and S2 were studied, the environmentally superior alternatives are briefly described.
The environmentally superior S2A/S2 alternative route begins at the existing Contra Costa-Newark transmission line immediately southwest of the Zone 7 Del Valle water treatment plant, on private property. An overhead-underground transition station would be constructed adjacent to the Contra Costa-Newark line. From this point, the line would be placed underground immediately west of Foley Road, within two private property parcels, continuing west/northwest adjacent to Foley Road, just outside of the roadway right-of-way. Where Foley Road and Vineyard Avenue intersect, the underground transmission line would turn west along Vineyard Avenue, crossing Highway 84. From Highway 84, the underground route would be located in the firebreak road south of Vineyard Avenue, past Isabel Avenue (where a bored crossing beneath the roadway would likely be required). From Isabel Avenue, the underground line would continue along the firebreak road for approximately 0.9 miles until the point at which New Vineyard Avenue diverges to the northwest. The underground line would continue along New Vineyard Avenue (within the roadway or immediately adjacent to it) until it reconverges with (Old) Vineyard Avenue. Where Vineyard Avenue becomes a divided roadway, the transmission line would be installed within the roadway. The transmission line travels underground on Vineyard Avenue to Bernal Avenue. Where Vineyard Avenue meets Bernal Avenue, the line would turn north on Bernal Avenue (still underground), and into the Vineyard Substation. Based on PG&E's estimates the total length of this route is 5.72 miles, all underground. (PG&E June 4, 2001 Cost Information Filing.)
The S2A/S2/S5 route mirrors the S2A/S2 route onto New Vineyard Avenue. Whereas S2A/S2 continues along New Vineyard Avenue, the S2A/S2/S5 alternative would turn north (from New Vineyard Avenue) at the location where the existing 60 kV line crosses Arroyo del Valle Creek, across from the future Neal Elementary School. The line would be installed underground at the creek crossing by means of an open-trenched crossing which would end at a transition station located on quarry land where the line would be brought overhead. The overhead portion of the route begins at the transition station on quarry land (just north of Arroyo del Valle Creek). From this half-acre fenced transition station, three tubular steel transmission poles would be installed on quarry land, and a fourth pole would be located north of Stanley Boulevard. Approximately 8 to 10 more poles would be located along the north side of Stanley Boulevard to the west of the crossing at the quarry entrance, then the line would cross back to the south into the existing Vineyard Substation. The total length of this alternative would be approximately 6.4 miles with about 4.3 miles underground.
The S2/S2A route would be entirely underground from the Contra Costa-Newark transmission line to the Vineyard Substation. This alternative minimizes visual impacts, utilizes corridors with greater construction access, and follows disturbed corridors (adjacent to or within existing roadways). For these reasons, this route would have less impact on threatened species than PG&E's proposed project and other alternatives studied. Although this alternative passes residential areas along Vineyard Avenue near Bernal Avenue, the impacts on these areas have been determined in the FEIR to be less than significant.
The S2A/S2/S5 alternative, using the Quarry Route would result in overhead and underground lines of 2.1 and 4.3 miles, respectively. The underground lines along Vineyard Avenue would protect the views across the valley. This alternative avoids residential areas by traversing an existing quarry operation, but the overhead lines through the quarry would be visible from the Shadow Cliffs Regional Recreation Area.
The environmentally superior alternatives for the Pleasanton area have different tradeoffs for the western portions of the routes. S2/S2A is all underground and so results in no visual impacts. S2A/S2/S5 includes an overhead portion. The visual impact of this alternative is considered to be less than significant given the existing visual setting, but, if constructed, the overhead segment will exist and be visible for a long period of time. However, S2A/S2/S5 avoids proximity to residential neighborhoods and construction impacts associated with construction of an underground line. Because both alternatives use existing roadways or disturbed corridors, they will have similar impacts on other environmental factors. PG&E's proposed project would traverse undeveloped grazing land in its southern half, and relatively narrow residential streets in the northern half compared to the environmentally superior alternatives, which utilize existing or disturbed corridors, and wider streets.
The FEIR finds that the D1 alternative is environmentally superior to PG&E's proposed Dublin substation and D2 alternative for the Dublin/San Ramon area. The transmission line route to the D1 substation is primarily within the gravel preserve so would have minimal visual impacts or construction disturbance to the public. The D1 substation site is in the commercially zoned portion of the Dublin Ranch development, in an area where commercial and industrial growth is focused and there is a high demand for electricity. In comparison, PG&E's proposed Dublin substation would require new transmission lines across the open space of North Livermore, crossing several scenic canyon areas and disturbing many more miles of habitat.
In North Livermore, the FEIR finds that the No Project Alternative is environmentally superior to PG&E's proposed project and the alternatives studied because the environmental impacts of constructing the project in this pristine area would be greater than those of not constructing the project at this time. The North Livermore substation itself would create a significant and unavoidable visual impact, which would be avoided with the No Project Alternative. Because there is little ongoing or recent growth in the North Livermore area (in the vicinity of North Livermore Road), there would be no need to bring in distribution lines from other substations (the most likely action if the No Project Alternative were approved in this area).
However, for the North Livermore area, the FEIR identified the environmentally superior "build" alternative to be the P3 variant15 on PG&E's proposed project. Under this alternative, a five acre substation would be constructed on the west side of North Livermore Avenue at May School Road as proposed by PG&E. PG&E's proposed North Livermore substation site is preferred over the L1 and L2 alternative sites, with a 2.4-mile underground transmission line route to the Contra Costa-Newark line that would run along May School and Dagnino Roads and a private road. This underground route was proposed as a mitigation measure to reduce potential air quality impacts associated with the longer underground route (P2 Alternative), and to reduce the significant visual impacts of PG&E's proposed project route to this substation. The substation site would still create a significant and unavoidable visual impact, but impacts in nearly all other issue areas would be less with the P3 Alternative (all underground transmission lines) than for the L1 and L2 alternatives or PG&E's proposed project.
For Phase 2, the FEIR finds that the No Project Alternative is environmentally superior. Based on power flow modeling completed by PG&E with input from the ISO and the Commission's consulting engineer, the need for Phase 2 within the next few years is in doubt. Because any of the "build" alternatives would have some environmental impacts and the No Project Alternative would not result in construction of any Phase 2 facilities in the Tri-Valley area, the No Project Alternative is found to be environmentally superior.
However, for Phase 2, the FEIR identified the environmentally superior "build" alternative to be the construction of a switching station at the southern tap point for whichever Pleasanton area alternative is selected. Compared to construction of new transmission lines, the switching station alternative was found to be clearly environmental superior to the other alternatives because it would eliminate the need for construction of 10 to 15 miles of new transmission line to the Tesla Substation.
