Nevada Regional Haze 5

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5 

# Chapter Five

– Changes in Emissions: All Sources within the State (40 CFR 51.308(g)(4

))

Table of Contents

5.1 Status Summary

................................ ................................ ................................ ................ 2

5.2 Baseline and Progress Periods for Tracking Emission Changes

................................ ...... 2

5.3 Emissions from the 2002 Baseline Period

................................ ................................ ........ 5

5.4 Emissions from the 2008 Progress Period

................................ ................................ ....... 7

5.5 Emission Differences between the Baseline and Progress Periods

................................ .. 9

5.5.1 Sulfur Dioxide

................................ ................................ ................................ ........... 9

5.5.2 Oxides of Nitrogen

................................ ................................ ................................ .. 11

5.5.3 Ammonia

................................ ................................ ................................ ................. 13

5.5.4 Volatile Organic Compounds

................................ ................................ ................. 15

5.5.5 Primary Organic Aerosol

................................ ................................ ........................ 17

5.5.6 Elemental Carbon

................................ ................................ ................................ .... 19

5.5.7 Fine Soil

................................ ................................ ................................ .................. 21

5.5.8 Coarse Mass

................................ ................................ ................................ ............ 22Nevada Regional Haze 5

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### 5.1 Status Summary

Table 5

- 1 shows that emissions of all visibility impairing pollutants decreased from the 2002
baseline inventory to the 2008 comparison year inventory developed by the WRAP , except for
fine soil and co arse mass

. The increases in fine soil and coarse mass were likely due to updates in inventory development methodologies rather than actual increases. Sections 5.5.7 and 5.5.8

. Notably

, actual 2008 emissions are lower than the projected 2018 emissions for all poll utants except fine soil and coarse mass

. Point source SO 2 emissions alone decreased by 78 percent
between the baseline and 2008 inventories ( Table 5

- 5 ) , while NO x point source emissions decreased by over 50 percent ( Table 5

- 7 )

. This demonstrates a significant reduction in Nevada’s anthropogenic emissions of SO 2 and NO x and con firms the success of Nevada’s long

- term strategy for reducing emissions that are controllable within the State

.

Table 5

- 1

. Comparison of 2002, 2008 and 201 8 Emission Inventories for A ll Visibility Impairing Pollutants *

Pollutants 2002 Baseline

(tpy) 2008 Inventory

(tpy) 2018 Projection

(tpy) 2008 A ctuals a s

a Percent of 2018 P rojections Sulfur Dioxide 67,743 17

, 058 1 46,224 37 % Oxides of Nitrogen 162,397 119,513 135,496 88 %

Ammonia 12,092 9,382 14,503 6 5% Volatile Organic Compounds 897,102 351,142 897,707 39 %
Primary Organic Aerosol 24,734 11,816 24,822 48 %

Elemental Carbon 6,409 4,425 5,638 78 %

Fine Soil 21,208 40,301 24,134 1 67% Coarse Mass 161,142 321,257 188,287 1 71%
* The SO 2 and NO
x data include only gaseous emissions.



### 5.2 Baseline and Progress Periods for Tracking Emission Change s

40 CFR 51.308(g)( 4) requires an analysis tracking the change over the past five years of the emissions of pollutants from all sources and activities within th e s tate that contribute to visibility impairment. This c hapter describes the change in emissions between the baseline period and the progress period. In doing so, it relies principally on the WRAP TSD prepared for the western states to support the development of 5

- year progress reports

. Appendix A and WRAP 2013

. The WRAP TSD includes extensive analyses and comparisons of emissions data from source categories, displaying the differences between the baseline and progress period inventories for
Nevad a.

1 Nevada over

- reported 2008 NEI SO 2 emissions by 88 tons. This correction has been accounted for in Table 5

- 1

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The baseline period is represented by the 2000

- 2004 emission inventory developed by the WRAP for use in the initial RH SIPs. The development of the baseline (referred to as “2002” by the WRAP) or “ P lan02” inventories

was a cooperativ e effort between the
WRAP and the western states. The emissions reported by the states in the 2002 NEI served as the starting point for the P lan02 inventories.
The data were enhanced via efforts by contractors, WRAP workgroups,
and consultation with the WRAP states. Point, area, mobile, oil and gas, fire and dust source categories were better characterized through
this effort. Section 5.3 further
describes the d evelopment of the Plan02d inventory.

The inventory year chosen for comparison with the baseline year is
2008 as provided in the WRAP TSD

. WRAP 2013. The WRAP used the 2008 NEI as a starting point , then updated that inventory through its WestJump Air Quality Modeling Study (WestJump AQMS 2013)

, producing an updated and comprehensive inventory for year 2008

. WestJump2008

. Section 5.4 further describes the data sources used in developing the 2008 inventory

. E missions data is presented showing the change from the 2008 NEI to the 2011 NEI

, where available

. Emission inventories were complicated by the fact that a number of changes and enhancements
have occurred bet ween development of the baseline and current period inventories

. Thus, s ome of the differences between inventories are more reflective of changes in methodology, rather th an changes in actual emissions

. Some examples of the changes include using a revised mobile
model , different meteorological models , incorporation of state

- specific data, re

- categorization of sources into more appropriate source categories, regulatory changes, revised emission rates, and improvements to activity data. T he changes and enhancements are discussed more in Section 5.3 of this chapter and Table 3.2

- 1 of the WRAP TSD

. WRAP 2013

. These differences in methodologies will aff

ect the ability to make comparisons of inventories used for 2002 and 2008
estimates.
In Nevada’s 2009 RH SIP, emission summaries compared both gas eous and particulate
emissions of sulfur oxides ( SO x ) and NO x . Emission summaries in the WRAP TSD compared just gaseous emissions of SO 2 and NO x . The difference between gas eous and particulate
emissions and gas eous only emissions for point and area source categories, the primary source s 51.308(g) Periodic progress reports must
contain at a minimum . . . (4 ) An analysis tracking the change over the past 5 years in emissions of pollutants contributing to visibility impairment from
all sources and activities within the State. Emissions changes should be ident ified by type of source or activity. The analysis

must be based on the most recent updated emissions inventory, with estimates projected forward as necessary and appropriate, to account for emissions changes during the applicable 5

- year period.Nevada Regional Haze 5

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of SO 2 and NO x emissions, is less than one percent. For this report

, Nevada is conforming to the analysis performed by the WRAP for the TSD

. T herefore

, a comparison of the gaseous emissions of SO 2 and NO x is discussed in this chapter.

As evident in Section 5.3

, the majority of anthropogenic point source emissions in the baseline period are SO 2 and NO x . Thus, this c hapter focuses on the emission reductions from point
sources of SO 2 and NO x . Table 5

- 2 lists the different source categories that comprise anthropogenic and natural sources of visibility

- impairing pollutants general ly

.

Table 5

- 2

. Anthropogenic and Natural Source Categories

Anthropogenic Source Categories Natural Source Categories

Point Sources Natural Fire Sources Anthropogenic Fire Sources Biogenic Sources Area Sources Wind Blown Dust WRAP Oil and Gas Sources On

- Road Mobile Sources Off

- Road Mobile Sources Road Dust Fugitive Dust

Table 5

- 3 lists the major emitted pollutants inventoried, the related monitored aerosol species, some of the major sources for each pollutant

, and some notes regarding implications of these pollutants. Appendix A, Table 6.8

- 7

Table 5

- 3 . Pollutants, Aerosol Species and Major Sources

Emitted Pollutant Related

Aerosol Major Sources Notes

Sulfur Dioxide (SO 2 ) Ammonium

Sulfate Point Sources;

On

- a nd Off

Road Mobile Sources SO 2 emissions are generally associated with anthropogenic

sources , such as coal

- burning power plants, other industrial sources such as refineries and cement plants, and both on

- and off

road diesel engines. Oxides of Nitrogen (NO
x ) Ammonium

Nitrate On

- a nd Off

Road Mobile Sources; Point Sources; Area Sources NO
x emissions are generally associated with anthropogenic

sources. Common sources include virtually all combustion activities, especially those involving cars, trucks, power plants, and other industrial processes.

Ammonia (NH 3 ) Ammonium

Sulfate and A mmonium Nitrate Area Sources;

On

- Road Mobile Sources Gaseous NH 3 has implications in particle formation because it can

form particulate ammonium. Ammonium is not directly measured by the IMPROVE program, but affects formation potential of ammonium sulfate and ammonium nitrate. All measured nitrate and sulfate is assume d to be associated with ammonium for IMPROVE reporting purposes. Volatile Organic Compounds (VOCs) Particulate

Organic Mass (POM) Biogenic

Emissions; Vehicle Emissions; Area Sources VOCs are gaseous emissions of carbon compounds, which are

often converted to POM through chemical reactions in the atmosphere. Estimates for biogenic emissions of VOCs have undergone significant updates since 2002, so changes reported here are more reflective of methodology changes than actual changes inNevada Regional Haze 5

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Emitted Pollutant Related

Aerosol Major Sources Notes

emissi ons

. S ee Section 3.2.1 of the WRAP TSD

.

Primary Organic Aerosol ( POA ) POM Wildfires; Area Sources POA represents organic aerosols that are emitted directly as

particles, as opposed to gases. Wildfires in the west generally dominate POA emissions, and large wildfire events are generally sporadic and highly variable from year to year. Elemental Carbon (EC) EC Wildfires; On

- a nd Off

Road Mobile Sources Large EC events are often associated with large POM events

during wildfires. Other sources include both on

- and off

- road diesel engines.

Fine soil Soil Windblown Dust; Fugitive Dust; Road Dust; Area Sources Fine soil is reported here as the crustal or soil components of

PM 2.5 .

Coarse Mass (PMC) Coarse

Mass Windblown

Dust; Fugitive Dust Coarse mass is reported by the IMPROVE Network as the

difference between PM 10 and PM 2.5 mass measurements. Coarse mass is not separated by species in the same way that PM 2.5 is speciated, but these measurements are generally associated with crustal components. Similar to crustal PM 2.5 , natural windblown dust is often the larges t contributor to PMC.



### 5.3 Emissions from the 2002 Baseline Period

The baseline period emissions are represented by the 2002 inventory developed by the WRAP
for the initial RH SIPs

. This effort built upon 2002 emission s submitted by states to US EPA for
the 2002 NEI and inc orporat ed work by contractors and WRAP workgroups in consultation with

states. Base02 was the first inventory , which used actual 2002 data and represented actual
conditions in calend ar year 2002 . Subsequent to the Base02 inventor y , a series of Plan02 inventories were developed ( Plan02a, Plan02b, Plan02c and Plan02d ) using 2000 through 2004
data . The purpose of the inventory series was to represent baseline emission patterns based on average, or typical, conditions rather than a single year

. The Plan02d emission inventory was a result of minor changes to the Plan02c inventory. The Plan02d inventory provides the basis in this report for comparison with the 2018 projected emissions, a s well as for gauging reasonable progress with respect to future year visibility

.
D ata comparisons were made between the baseline and 2008 emission inventory periods for nine source categories

. A summary of the emission inventory descriptions for the Plan02d source categories follows

. A more detailed description can be found in the WRAP TSD

. WRAP 2013,
Table 3.2

- 1

.
1. Point source inventory

– This inventory was generated using hourly US EPA CAMD continuous emission monitoring ( CEM ) data for EGUs. Other po int source emissions

were developed in consultation with states

.Nevada Regional Haze 5

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2. Area source inventory

– This inventory was developed by the WRAP contractor , E astern
R esearch G roup , in consultation with states.

3. Area oil and gas

– The oil and gas inventories were developed for specific oil and gas basins using WRAP Phase II emissions methodologies. If Phase II emission methodologies were not available, then state

- reported emissions were used. Nevada did not report oil and gas emissions. However, Nevada was included in the Phase II oil and

gas inventory; therefore emissions for the baseline period for Nevada exist.

4. On

- road m obile

– This inventory was generated using US EPA’s MOBILE6 model as applied by ENVIRON using inputs from states.

5. Off

- road m obile

– This inventory was generated using NONROAD2004 model as applied by ENVIRON using inputs from states.

6. Fugitive d ust and r oad d ust

– This inventory was generated using the WRAP 2002 inventory by ENVIRON with initial inputs from stat es. Vegetative scavenging factors were applied pre

- processing at the county level, as opposed to grid

- level for 2008 data.

7. Windblown d ust

– This inventory was generated using the WRAP Windblown Dust
Model and the 200 2 Meteorological Mesoscale 5 ( MM5 ) grid ded meteorolog ical data at 36 km grid cell resolution. Vegetative scavenging factors were applied pre

- processing at the county level, v ersu s post

- processing at the grid cell level for 2008.

8. Biogenic

– This inventory was generated using BEIS3.12 model, BELD3 land use and 2002 MM5 meteorolog ical data, at 36 km grid cell resolution

.
9. Fires ( n atural and a nthropogenic)

– This inventory was generated using the WRAP’s Phase III fire inventory, which represented a 5

- year average of fire activity from 2000 to
200 4

.
Table 5

- 4 provides Nevada emissions data by pollutant f r om the Plan02d baseline inventory

. P oint sources contribute 32 percent of the total anthropogenic em issions

. Of that 32 percent, SO 2 and NO x emissions account for 92 percent of the anthropogenic point source emissions and 29 percent of total anthropogenic emissions

. Clearly

, SO 2 and NO x emissions from point sources are the primary

, controllable visibil ity impairing pollutants in the baseline inventory.

Table 5

- 4 . Emissions from Plan02d Baseline Inventory in Tons

Plan02d Point Source

Anthropogenic Emissions Total Anthropogenic Emissions Total Natural Emissions (fire + biogenic + dust) SO 2 50,720 65,543 2,200 NO x 59,864 139,353 23,044
NH 3 339 10,408 1,684 VOC 2,215 85,357 811,745Nevada Regional Haze 5

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POA 256 2,233 22,501 EC 13 1,735 4,674 Fine Soil 2,158 9,364 11,845 Coarse Mass 4,093 62,020 99,122
Total 119,658 376,013 976,815



### 5.4 Emissions from the 2008 Progress Period

The progress period is represented by the WRAP’s WestJump2008 inventory. Data comparisons
were made between the baseline and 2008 emission inventory periods for Nevad a in nine
different source categories

. The WRAP continues to refine inventories and conduct studies to better estimate emissions from the different source categories. A summary of the sources of data used for each source category for the progress period follows; a more detailed de scription of the
inventories used in developing the WestJump 2008 inventory can be found in the WRAP TSD

. WRAP 2103, Table 3.2

- 1. When d ifferent models or data sources were used in the 2008 inventory as compared to the baseline inventory, those difference s are noted below

.
1. Point source

– The WRAP WestJump 2008 inventory w as generated using hourly US EPA
CAMD CEM data for EGUs

. WestJump AQMS 2013

. Other point sources emissions
are from the 2008 NEI v2. Point source oil and gas inventories were inventoried separately for WestJump 20 08 and are included in this point source inventory.

2. Area source

– The area source category is now referred to as the “non

- point” emission
sector category by US EPA. WRAP’s WestJ ump2008 inventory used state

- reported area
source inventories from the 2008 NEI v2. The WRAP included stationary area sources, agricultural and natural ammonia emission sources, oil and gas production operations, and biogenic emissions for the non

- point s ector in addition to the typical area source emission categories

. 2 Beginning in 2008

, s ome sources that were previously considered
“off

- road” were incorporated into the area source inventory , i.e., commercial marine vessels, vessels on in

- land waterways a nd in

- transit locomotive emissions

. For the WestJump2008 inventory, area oil and gas emissions were reported separately.

3. Area oil and gas

– The oil and gas inventories were developed for specific oil and gas basins using WRAP Phase III emission methodologies

, based on Version 2.0 of the 2008
NEI

. Twelve additional categories were included for t he 2008 progress period than were used in the 2002 baseline inventory. New emission methodologies

, especially for VOC
emission rates

, were used. If WRAP Phase III emissions methodologies were not available, area source oil and gas emissions as reported by the states to the 2008 NEI
were used

. Nevada did not report oil and gas emissions to the 2008 NEI

. Furthermore

,

2 TSS Stationary Area Sour ce Emissions June 2011.doc (last viewed 5/21/2014), located on the TSS website, http://vista.cira.colostate.edu/docs/wrap/emissions

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since N evada was not included in the oil and gas basins for the WestJump study, there were no estimates for 2008 oil and gas emissions for Nevada.

4. On

- road m obile

– US EPA’s Motor Vehicle Emission Simulator ( MOVES ) 2010 model was applied to state inputs. Inputs were updated with new V ehicle M iles T raveled (VMT) and controls on vehicles.

5. Off

- road m obile

– T he 2008 off

- road mobile inventory was obtained from the 2008 NEI v2, using NONROAD model estimates from within the National Mobile Inventory
Model. One important methodology change w as the reclassification of some sources previously labeled off

- road ; these sources were included in the non

- point (area) sources
in 2008.

6. Fugitive d ust and r oad d ust

– T hese emissions were extracted from state

- reported area
source estimates from the 2008 NE I v 2

. Vegetative scavenging factors were applied
post

- processing at a higher resolution grid cell level than for the 2002 data

.
7. Windblown d ust

– Emissions were generated using the WRAP Windblown Dust Model and a different meteorological model, 2008 WRF, at 4 km and 12 km grid cell resolution

v ersu s 36 km resolution in the baseline period. There were significant updates to enhance the accuracy of the WRAP Windblown Dust Model ; thus

, it will affect comparisons between the baseline period and the 2008 inven tory. Vegetative scavenging factors were applied post

- processing at the grid cell level rather than pre

- processing at the county level for 2002. The WestJump AQMS project included many technical updates and improvements including refinements to the grid, meteorology and land

- cover data thus improving the data results for the dust modeling. Th e study on dust emission sources for the WestJump AQMS was presented as Technical Memorandum No. 6: Dust
Source Emissions. 3

8. Biogenic

– A different m odel

, Model of Emissions of Gases and Aerosols from Nature ( MEGAN ) 2.10

, was used along with different meteorology data , 2008 WRF, at a finer grid cell resolution, 4 km and 12 km.

9. Fires ( n atural and a nthropogenic)

– The WRAP used DEASCO3 4 fire summaries to account for fires in 2008 rather than a 5

- year average of fires as was used in the baseline inventory. The tables in this report compare fire inventories between the baseline period

, a five

- year average from 2000

- 2004, and 2008, one

- year of data from the DEASCO3 study , although t his results in a somewhat misleading comparison

. There was separate reporting of anthropogenic and natural fires.

3 http://wrapair2.org/pdf/Memo6_Dust_Mar11_2013review_draft.pdf (last viewed 5/21/2014)

4 “ Deterministic and Empirical Assessment of Smoke’s Contribution to Ozone ,” https://deasco3.wrapt ools.org/ (last viewed 5/20/2014)Nevada Regional Haze 5

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### 5.5 Emission Differences b etween the Baseline and Progress Periods

This section analyzes the change in emissions betwee n the baseline (Plan02d) and 2008 (WestJump2008) inventories and includes comparison of some source category changes between
the 2008 and 2011 NEIs

. As noted earlier in this report

, a number of changes and enhancements have occurred between development of the baseline and current period inventories. Where such changes in methodology affect the 2008 data, they are identified in the following discussion.

The d ata by s ource type are shown below for the following emission species: s ulfur d ioxide,

o xides of n itrogen, a mmonia, v olatile o rganic c ompounds, p rimary o rganic aerosol

, e lemental

c arbon, f ine s oil and c oarse m ass.

5.5.1 S ulfu r Dioxide

Table 5

- 5 shows SO 2 emissions by source category for the baseline and 2008 inventories

. Table
5

- 6 presents 2008 and 2011 NEI data for the point and mobile source categories

. The primar y source of SO 2 in Nevada is from point sources. Nevada’s point sources contribute 75 percent of
total (anthropogenic and natural) statewide SO 2 emissions in the Plan02d inventory and 6 5 percent of total statewide SO 2 emissions in the WestJump2008 inventory. Point source SO 2 emissions alone decreased by 78 percent between the 2002 and 2008 inventories. The NEI point

source inventory shows a further decrease of 4 4 percent in SO 2 emissions from 2008 to 2011 ( Table 5

- 6 )

. 5 Area source SO 2 emissions decreased 63 percent from 2002 to 2008

. Due to the complexity of the calculation of the area source emissions, there are no area ( aka non

- point)
emissions obtained directly from the NEI.

Table 5

- 5

. Sulfur Dioxide Emissions by Category

Source Category Sulfur Dioxide Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference (Perce nt Change) Anthropogenic Sources Point 50,720 11,067 6

- 39,653 Area 12,953 4,863

- 8,090 On

- Road Mobile 454 298

- 156 Off

- Road Mobile 1,403 322

- 1,081 Area Oil and Gas 0 0 0 Fugitive and Road Dust 0 0 0 Anthropogenic Fire 12 2

- 10 Total Anthropogenic 65,543 16,552

- 48,991 (

- 75 % ) Natural Sources

5 Note that the 2008 NEI emissions are slightly different from the WestJump2008 inventory, which leverages more recent inventory development work performed by the WRAP.

6 Nevada over

- reported 2008 NEI SO 2 point emissions by 88 tons

, due to incorrect emission unit and transcription

errors. This correction has been accounted for in Table 5

- 5 and Table 5

- 6

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Natural Fire 2,200 506

- 1,694 Biogenic 0 0 0 Wind Blown Dust 0 0 0
Total Natural 2,200 506

- 1,694 (

- 77 % ) All Sources Total Emissions 67,743 17,058

- 50,685 (

- 75 % )

O n

- road mobile source SO 2 emissions decreased 34 percent from the Plan02d to the WestJump2008 inventory

, while t he NEI data show a further 47 percent de crease from 2008 to
2011. Off

- road mobile source SO 2 emissions decreased by 77 percent from the Plan02d inventory to WestJump2008 inventory and 87 percent from 2008 to 2011 based on the NEI

.
In sum, Table 5

- 5 shows a ll source categories of SO 2 decreased between the Plan02 d and WestJump2008 inventories. Total anthropogenic and total anthropogenic plus natural emissions both saw a net decrease of 75 percent between the Plan02d and WestJump2008 emission
inventories. The large reduction of SO 2 emissions for point sources is primarily due to the
closure of M ohave in southern Nevada . The reductions in SO 2 emissions from mobile sources

are likely due to the required use of low sulfur diesel fuel discussed in Chapter Three

, S ection
3.3

.

There is a significant decrease in SO 2 e missions f rom p oint and mobile sour ces in the 2008 and
2011 NEI ( Table 5

- 6 )

. This is primarily due to reductions in coal

- fired power plant emissions , as discussed in Chapter Three , as well as reductions from on

- road and off

- road mobile source
emissions

.
Table 5

- 6

. SO 2 NEI E missions (2008 and 2011)

Source Category SO 2 Emissions (tons/year)

2008 NEI 2011 NEI

(% change from 2008)

Point 10,409 7 5,863 8 (

- 44 % )

On

- Road Mobile 511 270 (

- 47 % )

Off

- Road Mobile 316 41 (

- 87 % )

Figure 5

- 1 presents a graphical display of the difference in SO 2 emissions by source category for the baseline period and the current progress period from the WRAP TSD

. Appendix A

. While
there are sign ificant reduction s in SO 2 emissions from both area and point sources , the reduction from point sources is especially noteworthy

.

7 See supra n.7.

8 Nevada under

- reported 2011 NEI SO 2 point emissions by 427 tons

, due to incorrect emission unit and transcription

errors. This correction has been accounted fo r in Table 5

- 6

. SO 2 NEI E missions (2008 and 2011)Nevada Regional Haze 5

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Figure 5

- 1

. 2002 and 2008 Sulfur Dioxide Emission s and Difference s by Source Category

5.5.2 Oxides of N

itrogen

Table 5

- 7 shows NO x emissions by source category for the baseline and 2008 inventories; Table
5

- 8 presents 2008 and 2011 NEI data for the point and mobile source categories

. The primary anthropogenic source categories of NO x emissions in Nevada are point and on

- road mobile, followed by o ff

- road mobile, and area sources. Nevada’s point sources contribute 37 percent of
total statewide NO x emissions in the Plan02d inventory , decreasing to 25 percent in the WestJump 2008 inventory

. P oint source emissions alone decreased by over 50 percent between
the 2002 and 2008 inventories

. The NEI point source inventory shows a decrease of 57 percent
in NO x emissions from 2008 to 2011.

NO x emissions from on

- road mobile sources increase d 2 2 percent from the Plan02d to the WestJump 2008 inventory. The i ncrease can be attributed in part to the use of a different model
to estimate on

- road mobile emissions. MOBILE6 was used for the 2002 baseline inventory

, whereas a new model

, MOVES2010

, was us ed for the 2008 progress period. The MOVES2010
model results in higher overall NO x and PM 2.5 emissions

, but lower VOC emissions. 9 The increase may also be partly due to a growth in the vehicle population, coupled with the fact that
reductions from the federal vehicle emission standards have not yet been fully reali zed (see Chapter Two)

. Four Nevada counties , comprising nearly three

- quarters of the State ’s population

, contributed over 70 percent of the increase : Clark County

, 28 percent; E lko County

, 18 percent; Pershing County

, 12 percent; and Humboldt County

, 12 percent

. http://nvdemography.org/data

-

9 Introduction to MOVES for Non

- Modelers, August 2012, http://www.dvrpc.org/NTAQS/pdf/MOVES_training.pdfNevada Regional Haze 5

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and

- publications/ , 2008 data

. NEI data show a 36 percent increase in on

- road mobile NO x emissions from 2008 to 2011 , possibly related to a 2 percent popu lation growth in Clark County and 3 percent in Washoe County

.

Off

- road mobile source emissions contribute 20 percent of total statewide NO x emissions in the Plan02d inventory , decreasing to 14 percent in the WestJump 2008 inventory

. O ff

- road mobile
source emissions alone decreased by 48 percent

. NEI data also show a decrease in off

- road
mobile emissions from 2008 to 2011 of 12 percent ( Table 5

- 8 )

.
Overall, in the progress period 2002 to 2008, total anthropogenic emissions of NO x in Nevada decreased by 23 percent ( Table 5

- 7 and Figure 5

- 2 ). Total NO x emissions saw a net decrease of
26 percent between the Plan02d and WestJump2008 emission inventories. Increases in on

- road mobile and area source inventory totals were offset by larger decreases in point and off

- road
mobile totals. The increase in emissions for area sources from the 2002 to the 2008 inventory may be a result of a re classification of some off

- road mobile sources into the area source category. This reclassification may have also contributed to the decrease in the emissions for the
off

- road inventory totals.

Table 5

- 7 . Oxi des of Nitrogen Emissions by Category

Source Category Oxides of nitrogen Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point 59,864 29, 344 10

- 30, 520 Area 5,725 11,321 5,597 On

- Road Mobile 41,089 50,068 8,979 Off

- Road Mobile 32,565 17,081

- 15,484 Area Oil and Gas 63 0

- 63 Fugitive and Road Dust 0 0 0 Anthropogenic Fire 48 13

- 35 Total Anthropogenic 139,353 107,827

- 31, 526 (

- 2 3 % ) Natural Sources Natural Fire 8,026 3,575

- 4,451 Biogenic 15,018 7,364

- 7,654 Wind Blown Dust 0 0 0
Total Natural 23,044 10,939

- 12,105 (

- 53 % ) All Sources Total Emissions 162,397 118,766 11

- 43,631 (

- 26 % )

10 Nevada over

- reported 2008 NEI NO
x emissions by 746 tons
, due to incorrect emission unit and transcription

errors. This correction has been accounted for in Table 5

- 7 and Table 5

- 8

. 11 See supra n. 10

.Nevada Regional Haze 5

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- 8 . NOx NEI Emissions (2008 and 2011)

Source Category NOx Emissions (tons/year)

2008 NEI 2011 NEI

(% change from 2008)

Point 20,934 12 10,548 13 (

- 50 % )

On

- Road Mobile 40,643 55,389 ( 36 % )

Off

- Road Mobile 16,797 14,706 (

- 12 % )

Figure 5

- 2 sh ows a graphical display of the difference in NO x emissions by source category for the baseline period and the current progress period from the WRAP TSD

. Appendix A. The
reduction in emiss ions from point and off

- road mobile sources is noteworthy.

Figure 5

- 2

. 2002 and 2008 Oxides of Nitrogen Emissions and Difference s by Source Category

5.5.3 Ammonia

Table 5

- 9 shows NH 3 emission s by source category , and Figure 5

- 3 shows the graphical display
from the WRAP TSD

. Appendix A. The primary source of anthropogenic emissions of NH 3 in
Nevada is from area sources , while natural fire is the dominant natural source of NH 3 emissions

.

12 See supra n. 10

. 13 Nevada under

- reported 2011 NEI NO
x point emissions by 1,494 tons, due to incorrect emission unit and transcription errors. This correction has been accounted for in Table 5

- 8

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 14

Nevada’s area sources contribute 66 percent of total statewide NH 3 emissions in the Plan 02d inventory and 6 1 percent of total NH 3 emissions in the WestJump2008 inventory. Area source s of NH 3 emissions alone decreased by 29 percent between the Plan02d and WestJump2008
inventories.

On

- road mobile sources showed a notable 58 percent decrease in NH 3 emissions between the
2002 and 2008 inventor ies

. On

- road mobile sources contribute 17 percent of total statewide NH 3 emissions in the Plan02d inventory and nine percent in the WestJump2008 inventory. N atural
fire contributes 14 a nd 27 percent in the 2002 and 2008 inventor ies, respectively

.
In sum, a ll anthropogenic source categories of NH 3 decreased between the Plan02d and WestJump2008 inventories. Total anthropogenic emissions of NH 3 saw a net decrease of 34
percent between the Plan02d and WestJump2008 emission inventories. In spite of the fact that
emissions from natural fires increased by almost 50 percent , total NH 3 emissions still decreased by a net of 22 percent.

Ammonia is not a criteria pollutant and is not inventoried or reported to the NEI ; t hus , no NEI
emissions data for NH 3 is provided

.

Table 5

- 9

. Ammonia Emissions by Category

Source Category Ammonia Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point 339 302

- 37 Area 8,009 5,717

- 2,293 On

- Road Mobile 2,030 849

- 1,182 Off

- Road Mobile 22 20

- 2 Area Oil and Gas 0 0 0 Fugitive and Road
Dust 0 0 0 Anthropogenic Fire 8 6

- 2 Total Anthropogenic 10,408 6,893

- 3,515 (

- 34 % ) Natural Sources Natural Fire 1,684 2,490 805 Biogenic 0 0 0 Wind Blown Dust 0 0 0 Total Natural 1,684 2,490 805 (48 % ) All Sources Total Emissions 12,092 9,382

- 2,710 (

- 22 % )Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 15

Figure 5

- 3 . 2008 and 2008 Ammonia Emission s and Difference s by Source Category

5.5.4 V olatile O rganic C

ompounds

Table 5

- 10 shows VOC emission s by source category ; Table 5

- 11 presents 2008 and 2011 NEI data for the point and m obile source categories

. Figure 5

- 4 shows a graphical display from the
WRAP TSD

. Appendix A

. The data show huge reductions in VOC emissions from natural sources with lesser reductions from anthropogenic sources . Biogenic emi ssions from natural sources dominate the Nevada VOC emissions inventory.
VOC emissions showed a 61 percent decrease overall, mostly due to a decrease in the biogenic emission inventory (67 percent). However, e stimates for biogenic emissions of VOCs have

u ndergone significant updates since 2002, hence changes reported here are more reflective of enhancements in the inventory methodology rather than actual changes in emissions

. Table 5

- 3

. Specifically, the P lan02d inventory used the BEIS3.12 model

, while the WestJump2008 inventory used the MEGAN2.10 model outputs. Also, different meteorological years were used,
2002 MM5 for the P lan02d inventory and 2008 WRF for the WestJump2008 inventory. In addition, higher temporal and spatial variability of land cover and improved emission factors based on better sources of data (e.g., satellites and field studies) were used for the WestJump2 008 inventory.

Th ere were also decreases in the on

- road m obile, natural fire and anthropogenic fire source categories. The decrease in o n

- r oad m obile emissions of VOCs is part ly due to the use of
differen t models. MOBILE6 was used for the Plan02d inven tory, while MOVES2010 was used
for 2008. There were also new VMT data and new controls on vehicles ( WRAP 2013, Table
3.2

- 1), which may account for some of the decrease in emissions. Specifically, VOC emissions are reduced due to implementation of the Tie r 2 Vehicle and Gasoline Sulfur Program discussed Chapter Two

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 16

For natural fire emissions, a detailed and comprehensive inventory was conducted for year 2008
in the DEASCO 3 study. 14 VOC emissions decreased significantl y in the WestJump2008 inventory. H owever, o nly fire emissions from a single year ( 2008 ) are represented here for the progress period. Thus, not all fire events for the 2005

- 2009 period are represented in the WestJump2008 inventory

. Due to the variability and sporadic nature of wildfire

, a comparison
between these inventories is complicated.

Table 5

- 10

. Volatile Organic Compound Emissions by Category

Source Category Volatile Organic Compound Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point 2,215 2, 5 30 15 3 38 Area 28,592 40,973 12,381 On

- Road Mobile 36,257 21,302

- 14,955 Off

- Road Mobile 18,094 18,783 688 Area Oil and Gas 129 0

- 129 Fugitive and Road
Dust 0 0 0 Anthropogenic Fire 70 16

- 54 Total Anthropogenic 85,357 84,026

- 1,331 (

- 2 % ) Natural Sources Natural Fire 17,606 4,204

- 13,403 Biogenic 794,139 262,912

- 531,227 Wind Blown Dust 0 0 0 Total Natural 811,745 267,115

- 544,630 (

- 67 % ) All Sources Total Emissions 897,102 351,142

- 545,960 (

- 61 % )

Table 5

- 11 shows a decrease in point source , on

- road mobile and off

- road mobile emissions of
VOC from the 2008 NEI to the 2011 NEI of 17 percent
, 20 percent and 18 percent , respectively.

14 See supra n. 4

. 15 Nevada over

- reported NEI 2008 VOC point emissions by 423 tons

, due to incorrect emission unit and transcription errors. This correction has been accounted for in Table 5

- 10 and Table 5

- 11

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 17 Table 5

- 11

. VOC NEI Emissions (2008 and 2011)

Source Category VOC Emissions (tons/year)

2008 NEI 2011 NEI

(% change from 2008)

Point 1,176 16 971 17 (

- 17 % )

On

- Road 27,084 21,779 (

- 20 % )

Off

- Road 18,759 15,328 (

- 18 % )

Figure 5

- 4 . 2002 and 2008 Volatile Organic Compounds Emission s and Difference s by Source Category

5.5.5 P rimary O rganic A erosol

Table 5

- 12 shows primary organic aerosol emissions by source category

, and Figure 5

- 5 shows the graphical display from the WRAP TSD

. Appendix A. Wildfires dominate the primary organic aerosol emissions for both the Plan02d and WestJump2008 inventor ies at 90 percent and 58 pe rcent
, respectively , although anthropogenic sources (area and mobile) are also an important component of the inventory. Large wildfire events are generally sporadic and highly variable from year to year

. T his variability is seen in the large reduction of primary organic aerosol
natural fire emissions between the Plan02d and WestJump2008 inventory years.

16 See supra n. 15

. 17 Nevada under

- reported NEI 2011VOC point emissions by 746 tons, due to incorrect emission unit and transcription errors. This correction has been accounted for in Table 5

- 11

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 18

Overall, total emission s of primary organic aerosols decreased by 52 percent from the Plan02d to the WestJump2008 inventory. Point source emissions of primary organic aerosols decreased by 82 percent over that period

. While source c ategories other than natural and anthropogenic fires and point sources saw increases in primary organic aerosol emissions

, the total percentage of the
other sources is eight percent and 42 percent of the total ( anthropogenic plus natural ) emissions for the Plan02d and WestJump2008 inventories

, respectively. The increase in area emissions is explained in Section 5.4 ; beginning in 2008

, s ome sources that were previously considered “off

road” were incorporated into the area source inventory . Clark and Washoe Counties , comprising 87 percent of the State population ( http://nvdemography.org/data

- and

- publications/ , 2008 data)

, contribute over 75 percent to total area emissions and 63 percent to total on

- road emissions in the WestJump2008 inventory.

Table 5

- 12

. Primary Organic Aerosol Emissions by Category

Source Catego ry Primary Organic Aerosol Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change)
Anthropogenic Sources Point* 256 46

- 210 Area 687 2,283 1,596 On

- Road Mobile 314 1,053 739 Off

- Road Mobile 572 689 117 Area Oil and Gas 0 0 0 Fugitive and Road
Dust 332 891 559 Anthropogenic Fire 73 22

- 51 Total Anthropogenic 2,233 4,985 2, 752 ( 123 % ) Natural Sources Natural Fire 22,501 6,831

- 15,670 Biogenic 0 0 0 Wind Blown Dust 0 0 0 Total Natural 22,501 6,831

- 15,670 (

- 70 % ) All Sources Total Emissions 24,734 11,816

- 12,918 (

- 52 % )

* Point source data includes only oil and gas and regulated CEM sources

. More comprehensive point source data were not available at the time this report was prepared but will be made available through the WRAP TSS ( http://vista.cira.colostate.edu/tss/ ).Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 19

Figure 5

- 5 . 2002 and 2008 Primary Organic Aerosol Emission s and Difference s by Source Category

5.5.6 E lemental C

arbon

Table 5

- 13 shows elemental carbon emissions by source category, and Figure 5

- 6 shows the graphical display from the WRAP TSD

. Appendix A

. Wildfires dominate d elemental carbon
emissions for the Plan02d inventory at 73 percent. Large wildfire events are generally spora dic and highly variable from year to year. Thus

, variability is seen in the elemental carbon emissions
from natural fire between the Plan02d and WestJump2008 inventory years.

Total elemental carbon emissions showed a 31 percent decrease between 2002 and 2008

. This was mostly due to a 76 percent decrease in emissions from natural fire. On

- road mobile, area and point source emissions increased from 2002 to 2008. On

- road mobile sources dominated the
elemental carbon emissions for the WestJump2008 invento ry at 43 percent , while wildfires contributed 26 percent. Area and point source emissions contribute less than one percent each to the 2008 inventory.

Clark County and Washoe County , comprising 87 percent of the State population ( http://nvdemography.org/data

- and

- publications/ , 2008 data)

, are the biggest contributors to the
area and on

- road mobile emissions for the 2008 invent ory. In the area source category
, Clark County’s contribution is 29 percent and Washoe County’s contribution is 17 percent. In the on

road source category

, Clark County’s contribution is 43 percent and Washoe County’s contribution is 16 percent.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 20 Table 5

- 13

. Elemental Carbon Emissions by Category

Source Category Elemental Carbon Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point * 13 64 5 1 18

Area 96 368 272 On

- Road Mobile 235 1,891 1,656 Off

- Road Mobile 1,354 954

- 400 Area Oil and Gas 0 0 0 Fugitive and Road
Dust 24 14

- 1 0 Anthropogenic Fire 13 6

- 7 19 Total Anthropogenic 1,735 3,295 1, 560 (90 % ) 20

Natural Sources Natural Fire 4,674 1,130

- 3,544 Biogenic 0 0 0 Wind Blown Dust 0 0 0 Total Natural 4,674 1,130

- 3,544 (

- 76 % ) All Sources Total Emissions 6,409 4,425

- 1,984 (

- 31 % )

* Point source data include s only oil and gas and regulated CEM sources

. More comprehensive point source data were not available at the time this report was prepared

, but will be made available through the WRAP TSS ( http://vista.cira.colostate.edu/tss/ ).

18 Note values in Table 5

- 13 are different than in the WRA P TSD, due to rounding.

19 See supra n. 18

. 20 See supra n. 18

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 21

Figure 5

- 6 . 2002 and 2008 Elemental Carbon Emission s and Difference s by Source Category

5.5.7 Fine Soil

Table 5

- 14 show s fine soil emissions by source category , and Figure 5

- 7 shows the graphical display from the WRAP TSD

. Appendix A. Fine soil emissions were identified as PM fine
emissions in the 2009 RH SIP

. F ine soil emissions inventor ies show increases in fugitive dust
and natural windblown dust from the Plan02d to the WestJump2008 inventory . These increases

are likely due to updates in inventory development methodologies rather than actual increases

. Appendix A, p. 6

- 2

.

Table 5

- 14

. Fine Soil Emissions by Category

Source Category Fine Soil Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point * 2,158 209

- 1,948 Area 830 1,024 195 On

- Road Mobile 239 21 190

- 49 Off

- Road Mobile 0 49 49 Area Oil and Gas 0 0 0 Fugitive

and Road Dust 6,128 19,216 13,087 Anthropogenic Fire 9 10 1

21 Fine soil emissions showed zero emissions for the on

- road source category in the 2009 RH SIP. This was strictly an oversight and has been corrected here.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 22

Source Category Fine Soil Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Total Anthropogenic 9,364 20,698 11,334 ( 121 % ) Natural Sources Natural Fire 1,406 2,552 1,146 Biogenic 0 0 0 Wind Blown Dust 10,438 17,051 6,613 Total Natural 11,845 19,603 7,758 ( 65 % ) All Sources Total Emissions 21,208 40,301 19,092 (90 % ) *Point source data includes only oil and gas and regulated CEM sources

. More com prehensive point source data were not available at the time this report was prepared but will be made available through the WRAP TSS ( http://vista.cira.colostate.edu/tss/ ).
Figure 5

- 7 . 2002 and 2008 Fine Soil Emission s and Difference s by Source Category

5.5.8 Coarse Mass

Table 5

- 15 show s coarse mass emissions by source category

, and Figure 5

- 8 shows the graphical display from the WRAP TSD

. Appendix A. Coarse mass emissions were identified as PM
coarse emissions in the 2009 RH SIP. Coarse mass emission inventories showed increase s in fugitive and road dust and natural windblown dust from the Plan02d to the WestJump 2008 inventory

. Fugitive dust includes sources such as agricultural operations, construction and mining operations and windblown dust from vacant lands. These increases in part can be
attributed to updates in inventory development methodologies rather than actual increases

. Appendix A, p. 6

- 2

. However, increases in the fugitive dust inventories may also be due to increases in population, while increases in road dust m ay be due to increases in estimated VMT

.Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 23

T he WestJump2008 inventory for coarse mass emissions is dominated by emissions in Clark and
Elko C ounties at 61 percent and 13 percent
, respectively. In Clark County

, particulate air pollution is lar gely associated with windblown dust, re

- entrained road dust, or construction
activities. 22 The windblown dust category includes more of the natural influences such as wind
erosion on natural lands. While point source and natural fire emissions decreased, m ost of the
other sources of coarse mass showed emission increases

.

Table 5

- 15

. Coarse Mass Emissions by Category

Source Category Coarse Mass Emissions (tons/year)

2002 (Plan02d) 2008

(WestJump2008) Difference

(Percent Change) Anthropogenic Sources Point * 4,093 1,761

- 2,331 Area 897 1,094 198 On

- Road Mobile 245 2,014 1,769 Off

- Road Mobile 0 82 82 Area Oil and Gas 0 0 0 Fugitive and Road
Dust 56,779 161,532 104,753 Anthropogenic Fire 7 4

- 3 Total Anthropogenic 62,020 166,488 104, 468 ( 168 % ) Natural Sources Natural Fire 5,176 1,310

- 3,866 Biogenic 0 0 0 Wind Blown Dust 93,946 153,459 59,513 Total Natural 99,122 154,769 55,647 (56 % ) All Sources Total Emissions 161,142 321,257 160,115 ( 99 % )

* Point source data includes only oil and gas and regulated CEM sources

. More comprehensive point source data were not available at the time this report was prepared but will be made available through the WRAP TSS ( http://vista.cira.colostate.edu/tss/ ).

22 http://www.clarkcountynv.gov/Depts/AirQuality/Documents/Planning/SIP/PM10/PM10_SIP_PLAN_without_Appe ndices.pdf (page 3

- 1; last viewed 8/29/ 2014)Nevada Regional Haze 5

- Year Progress Report, November 2014 5

- 24

Figure 5

- 8 . 2002 and 2008 Coarse Mass Emission s and Difference s by Source Category

As can be seen from the tables a nd figures in this chapter, visibility

- impairing emissions from point sources have significantly decreased with the exception of volatile organic compounds and elemental carbon. Point sources of both of these two pollutants contribute only a minor fractio n of the anthropogenic emission sources.