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Vantage to Pomona Heights Chapter 2 230 kV Transmission Line Project FEIS Proposed Action and Alternatives PAGE 2-11 Turn-around areas may be required in certain areas where construction travel would be restricted by rock outcrops, washes, ravines, or sensitive areas. Turn-around areas would typically require a temporary disturbance area of 60 feet by 60 feet (3,600 sq. ft./0.08 acre). Several material staging areas, roughly five acres each, would be required for material and equipment storage and for staging construction activities. For the EIS analysis, it is assumed that sites for material staging areas would be located on existing disturbed areas in areas approved by the landowner or agency. However, material staging areas would be determined during detail design and may include undisturbed areas, but preference would be given to currently disturbed sites. Pacific Power’s proposed Project, as described above, is for overhead transmission line construction (Overhead Design Option) which is considered feasible from the perspective of construction, operation, maintenance, and cost by Pacific Power (e.g., overhead steel or wood, H-frame, or single pole structures). In addition to the Overhead Design Option proposed by Pacific Power, this FEIS analyzes the option of undergrounding two discrete route segments of the NNR Alternative. The Underground Design Option is being analyzed in response to comments received from the U.S. Fish and Wildlife Service (USFWS) and Washington Department of Fish and Wildlife (WDFW) regarding potential Project impacts to Greater Sage-Grouse (Centrocercus urophasianus; hereafter, Sage-Grouse). The Underground Design Option is technically feasible, but construction and maintenance costs are expected to be higher than the Overhead Design Option. The impact analysis for the Underground Design Option is described and considered for each resource in the FEIS. Upgrades would also occur to Pacific Power’s Pomona Heights Substation and BPA’s Vantage Substation, located at the proposed Project’s termini at the north and the south ends. 2.1.2 Pomona Heights Substation Upgrades The new 230 kV transmission line would enter Pacific Power’s Pomona Heights Substation on the northwest edge of the substation. All new equipment would be installed within the existing substation fence. A new steel H-frame terminal structure would be required. New line breakers, new switches, various bus connections and other minor equipment and wiring would be installed to incorporate the new line into the interconnected regional electric transmission grid. 2.1.3 Vantage Substation Upgrades The Vantage Substation is owned by BPA. A currently occupied bay would be vacated within the substation for termination of the proposed new 230 kV transmission line. The proposed new transmission line would enter the east area of the substation. BPA would design and install the new equipment to interconnect the new 230 kV transmission line to the regional electric transmission grid. New substation equipment would be installed within the existing Vantage Substation fence. 2.2 PROJECT ACTIVITIES AND FEATURES COMMON TO ACTION ALTERNATIVES 2.2.1 Design Options Considered in the NNR Alternative Impact Analysis Two design options were developed and analyzed to determine the potential impacts of the proposed Project on resources identified in Chapters 3 and 4. These options are considered in this FEIS based on the various design and construction techniques proposed. The two design options that are considered are: 1) Overhead Design Option and 2) Underground Design Option. Potential impacts of variations on the