1 5.11.1 Common Impacts

7

(i.e., mobilization/staging, land clearing [grubbing and tree removal], topsoil

8

stripping, cut-and-fill operations [i.e., earthmoving], road construction, ground

9

excavation, drilling and blasting if required, and foundation treatment). An

10

updated list also includes disposal of cleared biomass by various methods,

11

which could include on-site burning of the biomass.

12

13

• The text of Section 5.11.1.2 of the Draft Solar PEIS discussing air quality

14

impacts associated with highly erodible soils (beginning at line 30 on

15

p. 5-146) is being updated to acknowledge the need to avoid desert pavement

16

and biological soil crusts. Disturbance of areas with biological soil crusts and

17

desert pavement should be avoided whenever possible, since once disturbed,

18

these areas can become dust sources. In addition, this update notes that

19

visibility modeling for construction activities may be required, at BLM’s

20

discretion, as part of the ROW application process or as part of the air permit

21

application process with the appropriate regulatory agency.

22

23

24

5.11.1.2

Operations: Update to Section 5.11.1.3 of the Draft Solar PEIS

25

26

• The discussion of fugitive dust emissions from wind erosion and vehicle

27

travel during operations (beginning at line 27 on p. 5-147 of the Draft PEIS)

28

is being updated to address the potential for dust generation from disturbed

29

desert pavement and fragile biological soil crusts, to note that, once disturbed,

30

these soils can become a major windblown dust source for long periods of

31

time, and to note that visibility modeling may be required. As stated in the

32

Draft Solar PEIS, because of the large area that could be disturbed and the fact

33

that stabilization is never fully effective, wind erosion during operation needs

34

to be addressed in site-specific assessments during the ROW application

35

process to assess the severity of these impacts. Visibility modeling may be

36

required, at BLM’s discretion, as part of the ROW application process or as

37

part of the air permit application process with the appropriate regulatory

38

agency.

39

40

In addition, in response to comments, it is acknowledged that low probability

41

events such as explosions, natural disasters (fires, tornadoes, earthquakes, and

42

severe storms), and terrorism could affect solar facilities. Consequences could

43

include injuries, loss of life, and the release of hazardous materials. Fires at

44

PV facilities could release cadmium into the atmosphere, but research has

45

indicated that less than 0.04% of the cadmium would be released in fires

46

(Fthenakis et al 2004). A terrorist attack would probably have impacts similar

Final Solar PEIS

5-17

July 2012

1

to those just noted for natural events. Additional discussion of the events, the

2

regulatory setting, and planning to reduce impacts are discussed in

3

Section 5.21.3 of the Draft Solar PEIS. The impacts of these events would

4

need to be evaluated and plans developed to deal with the impacts on a

5

project-specific basis.

6

7

8

5.11.1.3 Decommissioning and Reclamation: Update to Section 5.11.1.4 of the Draft

9

Solar PEIS

10

11

• Section 5.11.1.4 of the Draft Solar PEIS is being updated to note that visibility

12

modeling for decommissioning and reclamation may be required at BLM’s

13

discretion. This modeling may be part of the ROW application process or part

14

of the air permit application process with the appropriate regulatory agency.

15

16

17

5.11.1.4 Impacts of GHG Emissions: Update to Section 5.11.4 of the Draft

18

Solar PEIS

19

20

• Section 5.11.4 of the Draft Solar PEIS did not account for vehicle and

21

construction equipment emissions in the discussion of emissions avoided

22

through solar generation of electricity. Vehicle and construction emissions

23

represent fossil fuel combustion emissions; however, CO2 emissions

24

associated with construction equipment and vehicle use during the

25

construction and operation of a solar plant would be limited and much smaller

26

than the estimated CO2 emissions avoided (716 kg [1,578 lb] annually per

27

megawatt-hour of solar energy produced; see Table 5.11-1 of the Draft Solar

28

PEIS). Therefore, quantification of vehicle and construction equipment

29

emissions in the PEIS analyses is not needed.

30

31

• Section 5.11.4 is being supplemented to address potential emissions of sulfur

32

hexafluoride (SF6). SF6 is a GHG used as a dielectric in electrical equipment

33

such as transformers. One pound of SF6 has the same global warming

34

potential as about 12 tons of CO2. There is concern that if SF6 were used in

35

electrical equipment at solar facilities, accidental spills of the powerful GHG

36

would offset the benefits of avoided emissions from generating electricity

37

through solar power. Under design feature HS1-1, the BLM is directing

38

developers to consider use of alternative dielectric fluids that do not contain

39

SF6 at solar facilities on BLM-administered lands (Section A.2.2.22.2 of

40

Appendix A of this Final Solar PEIS). The BLM does not have jurisdiction

41

over transmission lines, and thus SF6 use associated with transmission lines

42

would need to be considered by other agencies.

43

44

Final Solar PEIS

5-18

July 2012