6.5.2.10 Air Quality and Climate

6Air quality would be affected locally and temporarily from fugitive dust emissions

7during construction of solar facilities; associated particulate matter concentrations could

8temporarily exceed ambient air quality standards near construction areas and possibly affect

9visibility in pristine areas such as National Parks or other Class I areas, especially in California,

10Colorado, and Nevada where multiple SEZs could affect such areas. In addition, long-distance

11transport of fugitive dust from SEZs could hasten snow melt in affected mountain areas.

12Application of measures included in an extensive dust abatement plan (a design feature for both

13BLM action alternatives) would substantially reduce the particulate matter levels generated

14during construction. The operation of solar facilities would produce very few emissions. Power-

15block facilities in solar thermal plants could produce some cooling tower drift if water cooling

16were used, as well as small levels of pollutants from natural gas or propane combustion from

17backup generators, and occasionally from emergency diesel generators. Portions of facilities that

18are maintained vegetation-free during operations could be a source of windblown fugitive dust,

19although design features requiring dust minimization would reduce this source. There also would

20be limited emissions from vehicles and natural gas–fired preheat boilers (if used).

21

22 Emissions from solar facilities would be mitigated and managed so that overall impacts 23 on local or regional air pollution problems would be reduced. Contributions to cumulative effects 24 on air quality would likewise be low, and cumulative effects from other foreseeable development 25 in most solar development regions would be low, given that renewable energy facilities are the 26 major type of new development expected to occur in the generally remote areas where solar

27 facilities would be built. However, the potential exists for cumulative impacts from solar energy 28 development on Class I areas. In addition, the cumulative impacts of long-range transport of

29 fugitive dust from multiple SEZs could affect snowmelt in mountains. Portions of the study area 30 have well-known ongoing air quality problems, primarily Southern California and Southern

31 Nevada. Solar developments in such regions would not worsen air quality, except for particulate 32 matter during construction. To the extent that solar facility operations avoid energy production 33 from fossil fuels, pollutants loads would be reduced for combustion-related pollutants such as 34 carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen oxides (NOx).

35

36Contributions to cumulative effects on air quality from fugitive dust emission would be

37reduced in some areas and increased somewhat in others from the consolidation of solar

38facilities, which could result from the elimination and modification of proposed SEZs since the

39issuance of the Draft Solar PEIS. Some areas would avoid effects while the effects in others

40could be intensified. Exceedances of particulate matter standards might increase slightly overall

41due to the combined effects of multiple projects in a localized area if construction were to occur

42at the same time.

43

44

3As discussed in Section 6.5.1.2.2, increasing atmospheric levels of GHGs (primarily

4CO2) are linked to global climate change (IPCC 2007; USGCRP 2009). Utility-scale solar

5energy development contributes relatively minor GHG emissions as a result of emissions from

6heavy equipment, primarily used during the construction phase; vehicular emissions; and natural

7gas or propane combustion from backup generators. The removal of plants from within the

8footprint of solar energy facilities would reduce the amount of carbon uptake by terrestrial

9vegetation, but only by a small amount (about 1% of the CO2 emissions avoided by a solar

10energy facility compared to fossil-fuel generation facilities [see Section 5.11.4 of the Draft and

11Final Solar PEIS]).

12

13Overall, CO2 emissions could be reduced if solar energy production avoids fossil fuel

14energy production over the next 20 years. CO2 emission reductions related to increased solar

15energy production could range from a few percentage points to more than 20% in some of the

16study area states if future fossil energy production were avoided by solar energy production.

17Table 6.5-22 of the Draft Solar PEIS remains unchanged but is repeated here for reader

18convenience; it provides a comparison of the CO2 emissions of different generation technologies

19during facility operations.

20

21In the near term, solar facilities would tend to reduce emissions from facilities serving

22peak loads rather than emissions from baseline loads served by large fossil fuel plants. Emissions

23from future fossil fuel plants serving peak loads, typically natural gas–fired plants, would

24nevertheless be avoided. The addition of thermal energy or electrical storage to solar facilities

25could allow avoidance of emissions from baseload fossil fuel plants in the long term.

26

27Because GHG emissions are aggregated across the global atmosphere and cumulatively

28contribute to climate change, it is not possible to determine the specific impact on global climate

29from GHG emissions associated with solar energy development on BLM-administered lands

30over the next 20 years. It is possible to predict, however, that increased solar energy generation

31could cumulatively result in fewer GHG emissions if it avoids electricity generation from new

32fossil fuel facilities.

33

34Cumulative effects on global climate change would not be significantly affected by the

35elimination or modification of SEZs, assuming no change in the RFDS.

36

37

38 6.5.2.11 Visual Resources

39

40The introduction of solar facilities in remote rural areas would alter the landscape and

41produce dramatic changes in the visual character of many affected areas. In addition, suitable

42solar energy production locations are in basin flats surrounded by mountains or highlands where

43sensitive viewing locations exist. Thus, visual impacts could be acute for some observers,

44including hikers and park visitors, as well as for certain groups, including Native American tribes

45or other ethnic groups who live in affected areas.

46

8long distances. Thus, solar development would be a major contributor to cumulative visual

9impacts from foreseeable development in the six-state region. Overall, cumulative impacts for all

10development could be significant, including impacts from wind and geothermal development,

11new roads, transmission lines, pipelines, canals, fences, communication systems, mining,

12agriculture, commercial development, aviation, road traffic, and OHV use. Visual impacts from

13solar facilities would be mitigated to the extent practical through the implementation of design

14features and through careful siting of facilities relative to sensitive viewing sites. Concerns for

15visual impacts could also affect solar technology selection, including, for example, concerns

16related to the height of solar tower facilities.

17

18Contributions to cumulative visual effects could be reduced overall from the elimination

19and modification of proposed SEZs since the issuance of the Draft Solar PEIS, due to the general

20consolidation of solar facilities, which would tend to reduce the number of facilities potentially

21lying near sensitive viewing areas. However, locations where facilities are located would have

22greater visual effects from more facilities.

23

24

25 6.5.2.12 Acoustic Environment

26

27Noise effects from heavy equipment and power tools during construction of solar

28facilities would be similar to those from any large construction project. Such impacts would

29depend on the type of solar technology being installed, with the lowest noise impacts for PV and

30dish engine installation and the greatest noise impacts and ground vibration associated with

31power block construction for solar energy facilities. Facility construction typically requires from

321 to 3 years, with intermittent noise nuisance effects possible on nearby residents and/or wildlife.

1Facilities would generally not be located near sensitive noise receptors, including specially

2designated areas such as national park units and wilderness areas, schools, hospitals, or

3 residential areas but could affect individual residences. Design features under the BLM action 4 alternatives to address noise during construction include limiting the daily hours of activities, 5 construction of noise barriers if needed and practicable, and coordination with nearby residents. 6

7 Noise for solar facility operations would be generally low and would depend on the solar 8 technology. PV facilities would produce little or no noise. Solar thermal facilities would produce

9low levels of continuous noise from power blocks and from cooling towers or cooling fans in air-

10cooled plants. Power blocks represent a localized noise source typically located near the center

11of a solar facility and far from facility boundaries. Dish engine facilities present the greatest

12concern for noise, because each dish represents a single, distributed noise source. While a single

13dish engine produces modest noise levels, a solar facility might employ thousands of them,

14presenting a significant noise concern near facility boundaries. Careful siting would mitigate

15such impacts. For example, SEZ-specific design features generally require siting of dish engine

16solar fields from 1 to 2 mi (2 to 3 km) away from residential areas. Since noise impacts are short

17range and solar development areas are mainly sparsely populated and otherwise largely

18undeveloped, few cumulative noise impacts would occur.

19

20Contributions to cumulative noise effects could be reduced overall from the elimination

21and modification of proposed SEZs since the issuance of the Draft Solar PEIS due to the general

22consolidation of solar facilities, which would tend to reduce the number of facilities potentially

23lying within or near sensitive noise receptors. However, locations where facilities are located

24would have greater local noise effects from more facilities.

25

26

27 6.5.2.13 Paleontological Resources

28

29Paleontological resources, mainly fossils, can be affected by construction excavation for

30solar facilities. Such effects can be mitigated by collecting or documenting fossils when

31encountered, with the aid of a paleontologist, or by avoiding areas rich in fossils. Many

32prospective solar areas have not been surveyed for fossils, and the presence of fossils can be

33inferred only by the types of geological deposits and soils present. Such areas would be surveyed

34prior to facility construction. Because of the vastness of the area, cumulative effects on

35paleontological resources in the six-state area from foreseeable development are expected to be

36small, while solar development could represent a major contribution to these small effects

37because of the large acreages disturbed for construction. However, while large in size, much of

38the area encompassed by solar arrays would not require deep excavation and thus would not

39likely disturb buried fossils. Foundations for solar collectors, reflectors, or dish engines

40typically involve minor or no excavation or employ a single piling driven into the ground. Deep

41excavations would occur for power block foundations, retention ponds, and other structures for

42some types of solar facilities. Shallow to moderately deep excavations for underground utilities

43and energy collector lines would be required at most facilities.

44