1 13 AFFECTED ENVIRONMENT AND IMPACT ASSESSMENT FOR 2 PROPOSED SOLAR ENERGY ZONES IN UTAH 3 4 5 13.1 ESCALANTE VALLEY 6 7 8 13.1.1 Background and Summary of Impacts 9 10 11 13.1.1.1 General Information 12 13 The proposed Escalante Valley solar energy zone (SEZ) is located in Iron County in 14 southwestern Utah (Figure 13.1.1.1-1). The SEZ has a total area of 6,614 acres (27 km2). In 15 2008, the county population was 45,833, while adjacent Washington County to the south had a 16 population of 148,256. The largest nearby town is Cedar City on Interstate 15 (I-15) in Iron 17 County; Cedar City had a 2008 population of 28,667 and is located about 30 mi (48 km) to the 18 east-southeast. Several small towns are located closer to the SEZ; Lund is about 4 mi (6 km) to 19 the north, and Zane is about 5 mi (8 km) to the west. Salt Lake City is located about 220 mi 20 (354 km) to the north–northeast. 21 22 The nearest major road is State Route 56, about 15 mi (24 km) south of the SEZ. Access 23 to the Escalante Valley SEZ is via county road; Lund Highway passes northeast of the SEZ. 24 Access to the interior of the SEZ is by dirt roads. The Union Pacific (UP) Railroad passes to the 25 west and has a rail stop in Lund. A rail spur off the main line at Lund passes through the 26 northeastern edge of the SEZ. Both state and private lands are nearby. The nearest public airport 27 is the Cedar City Regional Airport near Cedar City. A 138-kV transmission line ends about 3 mi 28 (5 km) from the southeastern area of the southernmost part of the SEZ. 29 30 As of February 2010, there were no right-of-way (ROW) applications for solar projects 31 within the SEZ. 32 33 The proposed Escalante Valley SEZ is in a rural area. The overall character of the 34 surrounding land is rural. The SEZ is located in the south-central portion of the Escalante Desert, 35 a large, southwest–northeast trending valley. The Escalante Desert is bounded by the Mineral 36 Mountains to the northeast, the Black Mountains and the Antelope Range to the south and 37 southeast, and the Shauntie Hills and Wah Wah Mountains to the northwest. Land within the 38 SEZ is undeveloped scrubland characteristic of a high-elevation, semiarid basin. 39 40 The proposed Escalante Valley SEZ and other relevant information are shown in 41 Figure 13.1.1.1-1. The criteria used to identify the proposed Escalante Valley SEZ in Utah as an 42 appropriate location for solar energy development included proximity to existing transmission 43 lines or designated corridors, proximity to existing roads, a slope of generally less than 2%, and 44 an area of more than 2,500 acres (10 km2). In addition, the area was identified as being relatively 45 free of other types of conflicts, such as U.S. Fish and Wildlife Service (USFWS)-designated 46 critical habitat for threatened and endangered species, Areas of Critical Environmental Concern Draft Solar PEIS 13.1-1 December 2010 1 2 FIGURE 13.1.1.1-1 Proposed Escalante Valley SEZ Draft Solar PEIS 13.1-2 December 2010 1 (ACECs), Special Recreation Management Areas (SRMAs), and National Landscape 2 Conservation System (NLCS) lands (see Section 2.2.2.2 for the complete list of exclusions). 3 Although these classes of restricted lands were excluded from the proposed Escalante Valley 4 SEZ, other restrictions may be appropriate. The analyses in the following sections evaluate the 5 affected environment and potential impacts associated with utility-scale solar energy 6 development in the proposed SEZ for important environmental, cultural, and socioeconomic 7 resources. 8 9 As initially announced in the Federal Register on June 30, 2009, the proposed Escalante 10 Valley SEZ encompassed 6,581 acres (27 km2). Subsequent to the study area scoping period, 11 the boundaries of the proposed SEZ were altered somewhat to facilitate the Bureau of Land 12 Management’s (BLM’s) administration of the SEZ area. Borders with irregularly shaped 13 boundaries were adjusted to match the section boundaries of the Public Lands Survey System 14 (PLSS) (BLM and USFS 2010a). Some small, higher slope areas internal to and at the borders 15 of the site were also added to the SEZ; although included in the SEZ, these higher slope areas 16 would not likely be utilized for solar facilities. The revised SEZ is approximately 33 acres 17 (0.13 km2) larger than the original SEZ as published in June 2009. 18 19 20 13.1.1.2 Development Assumptions for the Impact Analysis 21 22 Maximum solar development of the proposed Escalante Valley SEZ is assumed to be 23 80% of the SEZ area over a period of 20 years, a maximum of 5,291 acres (21 km2). These 24 values are shown in Table 13.1.1.2-1, along with other development assumptions. Full 25 development of the Escalante Valley SEZ would allow development of facilities with an 26 estimated total of 588 MW of electrical power capacity if power tower, dish engine, or 27 photovoltaic (PV) technologies were used, assuming 9 acres/MW (0.04 km2/MW) of land 28 required, and an estimated 1,058 MW of power if solar trough technologies were used, 29 assuming 5 acres/MW (0.02 km2/MW) of land required. 30 31 Availability of transmission from SEZs to load centers will be an important consideration 32 for future development in SEZs. The nearest existing transmission line is a 138-kV line 3 mi 33 (5 km) southeast of the SEZ. It is possible that this existing line could be used to provide access 34 from the SEZ to the transmission grid, but the 138-kV capacity of that line would be inadequate 35 for 588 to 1,058 MW of new capacity (a 500-kV line can approximately accommodate the load 36 of one 700-MW facility). At full build-out capacity, it is clear that new transmission and/or 37 upgrades of existing transmission lines would be required to bring electricity from the proposed 38 Escalante Valley SEZ to load centers; however, at this time the location and size of such new 39 transmission facilities are unknown. Generic impacts of transmission and associated 40 infrastructure construction and of line upgrades for various resources are discussed in Chapter 5. 41 Project-specific analyses would need to identify the specific impacts of new transmission 42 construction and line upgrades for any projects proposed within the SEZ. 43 44 To evaluate locations and amount of disturbed acreage for new transmission lines, it was 45 assumed that a transmission line segment would be constructed from the proposed Escalante 46 Valley SEZ to the nearest existing transmission line to connect the SEZ to the transmission Draft Solar PEIS 13.1-3 December 2010 TABLE 13.1.1.2-1 Proposed Escalante Valley SEZAssumed Development Acreages, Maximum Solar MW Output, Access Roads, and Transmission Line ROWs Assumed Total Acreage Assumed Distance and Area of Distance to and Assumed Maximum SEZ Distance to Capacity of Transmission Nearest Developed Output for Nearest State, Nearest Existing Line ROW Designated Acreage Various Solar U.S. or Interstate Transmission and Road Transmission (80% of Total) Technologies Highway Line ROW Corridore 6,614 acres and 588 MWb and State Route 56: 3 mi and 138 kV 91 acres and 4 mi 5,291 acresa 1,058 MWc 15 mid 109 acres a To convert acres to km2, multiply by 0.004047. b Maximum power output if the SEZ were fully developed using power tower, dish engine, or PV technologies, assuming 9 acres/MW (0.04 km2/MW) of land required. c Maximum power output if the SEZ were fully developed using solar trough technologies, assuming 5 acres/MW (0.02 km2/MW) of land required. d To convert mi to km, multiply by 1.609. e BLM-designated corridors are developed for federal land use planning purposes only and are not applicable to state-owned or privately owned land. 1 2 3 grid. This assumption was made without additional information on whether the nearest 4 existing transmission line would actually be available for connection of future solar facilities. 5 Establishing a connection to the line closest to the Escalante Valley SEZ would involve the 6 construction of about 3 mi (5 km) of new transmission line outside of the SEZ. The ROW for 7 this transmission line would occupy approximately 91 acres (0.37 km2) of land, assuming a 8 250-ft (76-m) wide ROW, a typical width for such an ROW. If a connecting transmission line 9 was constructed in the future to connect facilities within the SEZ to a different offsite grid 10 location from the one assumed here, site developers would need to determine the impacts from 11 construction and operation of that line. In addition, developers would need to determine the 12 impacts of line upgrades if they were needed. 13 14 State Route 56 lies about 15 mi (24 km) to the southeast of the proposed Escalante Valley 15 SEZ. Assuming construction of a new access road to reach State Route 56 would be needed to 16 support construction and operation of solar facilities, approximately 109 acres (0.44 km2) of land 17 disturbance would occur (a 60-ft [18.3-m] wide ROW is assumed).