Final ULP PEIS 3: Affected Environment 1 3 AFFECTED ENVIRONMENT 2 3 4 The ROIs affected by the proposed action presented in the ULP PEIS are described for 5 each resource area evaluated (see Appendix D for additional discussion on the determination of 6 the ROIs). This site-specific information will be 7 used as the basis for evaluating the potential Regions of Influence (ROIs) for the Various Resource Areas Evaluated 8 impacts from the alternatives discussed in in the ULP PEIS 9 Chapter 4. 10 Air Quality: Mostly within 31 mi (50 km) from the 11 source(s) but up to several hundred miles, a minimal but cumulative contribution to air quality- 12 3.1 AIR QUALITY related values (such as visibility and acid 13 deposition) 14 Noise: Within 2–3 mi (3–5 km), from noise 15 3.1.1 Climate source(s) at best 16 Paleontological Resources: Lease tracts and any 17 other areas on adjacent lands that could be affected 18 3.1.1.1 General Climate by mining activities 19 Soil Resources: The lease tracts and any other 20 Wide variations in elevation and areas on adjacent lands (e.g., unpaved access roads) that could be affected by mining activities 21 topographic features within the area Water Resources: Montrose, Mesa, and 22 surrounding the ULP lease tracts have an San Miguel Counties, primarily on the lease tracts; 23 impact on wind patterns, temperatures, and also the Dolores River, San Miguel River, and their 24 storm tracks in all seasons (NCDC 2011a). The tributaries 25 area has a semi-arid, mid-continental climate Human Health: 50-mi (80-km) radius of the lease 26 characterized by abundant sunshine, low tracts 27 humidity, low precipitation, and cold, snowy Land Use: The lease tracts and land within a 25-mi 28 winters. Strong, outgoing terrestrial radiation (40-km) radius of each lease tract, with an 29 provides cool nights. In midwinter, air emphasis on specially designated public land areas 30 temperatures are often low, but strong solar Ecological Resources: Montrose, Mesa, and San Miguel Counties, primarily on the lease tracts; 31 radiation and dry air combine to provide the Dolores River, San Miguel River, and Colorado 32 generally pleasant conditions. River (for threatened and endangered species 33 evaluation only) 34 The local climate is strongly influenced Socioeconomics: Montrose, Mesa, and San Miguel 35 by microclimatic features such as slope, aspect, Counties 36 and elevation. The prevailing wind direction Environmental Justice: 50-mi (80-km) radius of 37 aloft over the region is from the west or the the lease tracts 38 southwest (the westerlies), as it is in most of the Transportation: 25-mi (40-km) radius from the 39 United States; however, complex terrains in boundary of the lease tracts 40 western Colorado are responsible for deflecting Cultural Resources: Lease tracts and any other areas on adjacent lands that could be affected by 41 these winds. Accordingly, wind patterns are mining activities 42 sometimes dissimilar even over short distances. Visual Resources: 25 mi (40 km) from the lease 43 tracts 44 The ULP lease tracts are located in Waste Management: Surface mine plants on the 45 southwestern Mesa County and in western lease tracts 46 Montrose and San Miguel Counties in 3-1 March 2014 Final ULP PEIS 3: Affected Environment 1 southwestern Colorado. The elevations of lease tracts range from 5,100 ft (1,500 m) to 8,000 ft 2 (2,439 m) with an average elevation of about 6,401 ft (1,951 m). The area surrounding the ULP 3 lease tracts is characterized by complex topography with valleys, canyons, and plateaus, so the 4 climate varies considerably from place to place. 5 6 7 3.1.1.2 Wind 8 9 Wind roses (which graphically display the distribution of wind speed and direction) are 10 presented here based on data available from weather stations in place for the proposed Piñon 11 Ridge Mill, because they are located in the center of the ULP lease tracts scattered over a wide 12 area. These stations are referred to as Site 1 (33-ft [10-m] level) and Site 2 (98-ft [30-m] level). 13 Data for a 3-year period (April 2008–March 2011) are shown in Figure 3.1-1 (Rogers 2011). The 14 proposed Piñon Ridge Mill site is located in the eastern Paradox Valley in western Montrose 15 County, which is roughly at the center of ULP lease tracts. The Paradox Valley is aligned in a 16 northwest–southeast direction. Winds are controlled in large part by the valley and ridge 17 topography. At Site 1 (33-ft [10-m] level), winds blow more frequently from the northwest and 18 southeast, reflecting the channeling of winds parallel to the valley axis. The annual average wind 19 speed is about 6.3 mph (2.8 m/s). Average wind speeds are highest in spring at 7.9 mph (3.5 m/s) 20 and lowest in winter at 4.6 mph (2.1 m/s). Prevailing wind directions are from the southeast 21 (about 14% of the time) and the east–southeast (about 14% of the time). Secondary prevalent 22 wind directions are from the northwest and west-northwest about 18% of the time combined. 23 Thus, about half of the time, upslope and downslope winds along the valley axis prevail. 24 However, effects of prevailing westerlies aloft are relatively minor at the surface. Northwesterly 25 upslope winds blow more frequently during daytime, while southeasterly downslope winds (also 26 called drainage winds) prevail at night. 27 28 Wind rose at Site 2 (98-ft [30-m] level) of the proposed Piñon Ridge Mill site, which is 29 located about 1.3 mi (2.1 km) south–southeast of Site 1 on the same valley floor but closer to the 30 valley wall, is provided in Figure 3.1-1(b). Wind patterns are somewhat different from those at 31 Site 1 (33-ft [10-m]) level. Daytime upslope winds observed are like those at Site 1, while 32 nighttime downslope winds are relatively weak. Typically, downslope winds are shallower than 33 upslope winds, with little or no turbulence because of the stable temperature structure of the air. 34 Throughout the year, westerly or southwesterly winds prevail at Site 2, especially during 35 nighttime hours, suggesting it is more affected by regional winds than by local flows. Average 36 wind speed at Site 2 is about 5.9 mph (2.6 m/s). As it is at Site 1, wind speed at Site 2 is highest 37 in spring and lowest in winter. Prevailing wind direction at Site 2 is from the west–northwest 38 (about 12% of the time) and secondarily is from the west (about 12% of the time). Winds that 39 range from the southeast clockwise to northwest sectors, which is the lower-left half of the valley 40 axis, account for more than three-fourths of the time. 41 42 Typically, wind speeds at higher elevations are faster than those at lower elevations 43 because of surface friction. However, the reverse is observed at the proposed Piñon Ridge Mill. 44 The upslope-downwind speed at Site 2 is lower than that at Site 1, which is located on the central 3-2 March 2014 3-3 March March 3-3 F inal ULPPEIS 1 2 (a) (b) 3 FIGURE 3.1-1 Wind Roses at the Proposed Piñon Ridge Mill, Montrose County, Colorado, April 2008–March 2011: (a) Site 1, 33-ft 4 (10-m) Level; and (b) Site 2, 98-ft (30-m) Level (Source: Rogers 2011) 5 3: AffectedEnvironmen 2014 t Final ULP PEIS 3: Affected Environment 1 valley floor, due to friction with the nearby valley wall at Site 2 and because local flows seem 2 somewhat stronger than regional westerly winds. 3 4 Aside from the weather stations at the proposed Piñon Ridge Mill, there is also a BLM 5 Remote Automated Weather Station at Nucla near the ULP lease tracts. Nucla station is located 6 outside the southeastern edge of Paradox Valley, about 2 mi (3 km) south of Nucla and about 7 11 mi (18 km) east of the proposed Piñon Ridge Mill site. However, wind patterns are quite 8 different from those at Piñon Ridge Mill. As shown in Figure 3.1-2, prevailing wind directions 9 are from the east throughout the year due to predominant nighttime drainage winds from the 10 San Miguel River valley to the east (DRI 2011). During daytime hours, effects of the San Miguel 11 River valley, which runs in a northwest–southeast direction, parallel those of the Paradox Valley, 12 and regional westerly winds are more prominent. 13 14 15 16 FIGURE 3.1-2 Wind Rose at 20-ft (6.1-m) Level at Nucla, Montrose 17 County, Colorado, 2006–2010 (Source: DRI 2011) 18 3-4 March 2014 Final ULP PEIS 3: Affected Environment 1 3.1.1.3 Temperature 2 3 Temperatures in the region vary widely with elevation, latitude, season, and time of day. 4 In western Colorado, topography plays a large role in determining the temperature of any 5 specific location (NCDC 2011a). The ULP lease tracts sit at a higher elevation; thus, 6 temperatures there are lower than at lower elevations of comparable latitude. Historical annual 7 average temperatures measured at selected meteorological stations around the ULP lease tracts 8 range from 45.3F (7.4C) in Northdale (about 10 mi [16 km] south of the southernmost ULP 9 lease tract at an elevation of 6,680 ft [2,040 m]) to 53.9F (12.2C) in Gateway 1 SE (about 6 mi 10 [10 km] northwest of the northernmost ULP lease tract at an elevation of 4,550 ft [1,390 m]), as 11 presented in Table 3.1-1 (WRCC 2011a; DRI 2011).