## Chapter Four – Visibility and Source Apportionment Modeling

4.1 INTRODUCTION

4.1.1 Air Quality Models 4.1.2 Model Perform a nce Evaluation 4.1.2.1 2002 W o rst Days Perform a nce 4.1.2.2 2002 Best Days Performance 4.1.3 W e ighted Em issions Potential Analysis



### 4.2 VISIBILITY MODELI NG RESULTS FOR 2018

4.2.1 2018 Visibility Pro j ections for Jarbidge W ildern e ss Area



### 4.3 SOURCE APPORTIONMENT MODELI NG RES U LTS

4.3.1 Sulfate Source Apportionm ent fo r Jarbidge W ilderness Area 4.3.2 Nitrate Source Apportionm ent for Jarbidge W ilderness Area 4.3.3 Source Apportionm ent for Other Class I Areas 4.3.4 Organic Aerosol Source Apportionmen t for Jarbidge W ilderness Area 4.3.4.1 Organic Aerosol PSAT for W o rst Da ys 2002 and 2018 4.3.4.2 Organic Aerosol PSAT for Best Days 2002 and 2018 4.3.4.3 Organic Aerosol PSAT for All Days 2002 and 2018



### 4.4 WEIGHTED EMISSIONS PO TENTIAL ANALYSES RESULTS

4.4.1 Nitrogen Oxides – Regional W E P Analysis for 2018 W o rst Days 4.4.2 Sulfur Oxides – Regional W E P Ana l ysis for 2018 W o rst Days 4.4.3 Organic Carbon – Regional W E P Analysis for 2018 W o rst Days 4.4.4 Elem ental Carbon – Regional W E P Analysis for 2018 W o rst Days 4.4.5 Particulate Matter Fi ne – Regional WEP Analys is for 2018 Worst Days 4.4.6 Particulate Matter Coarse – Region al W E P Ana l ysis for 2018 W o rst Days



### 4.5 VISIBILITY AND SOURCE APPORTIONMENT MODELING SUMMARY

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-14 .1 INTRODUCTION

The regional haze ru le (RHR) requires states to “address regional haze in each m a ndatory Class I Federal area located within the State, and each mandatory Class I Federal area located outside the State which m a y be affected by em issions fr om within the State”. The RHR also requires goals be established to “provi de for reasonable progress toward achieving natural visibility conditions.” CFR 40 Par t51.308(d) Air quality modeling analyses were perform e d to determ ine which Class I areas are affected by em issions from Nevada and to evaluate reasonable progress, as discus sed in Chapter One. The W e ster n Regional Air Partners hip’s (WRAP) Re gional Modeling C e nter (RMC) perform e d these m odeli ng analyses for the WRAP states, including Nevada.

Visibility m odeling resu lts ind i ca te that the Jarb idge W ildern e ss Area ( J a r bidge W A ) will m eet the Uniform Rate of Progress (URP) for 2018. The m odeling results and technical analyses also indicate Nevada sources do contribute to visibility impair m e nt at the Jarbidge W A , as well as Class I areas located in adjacen t states. The m o deling also in dicates th at out-of-state sources have the g r eates timpact on regional haze in Ne v a da. Region al weighted em issions potential (W EP) analyses indicate the s i gnif i cant ro le of em issions f r om wind blown and f ugitive dust and natural fire in visibility impairm ent at th e Jarbidge W A , thereby supporting the anecdotal observations of the Nevada Divi sion of Environmental P r otecti on (NDEP) staff discussed in Chapter One.

The visibility and source apportionment m odeli ng described in this Chapter provides, in conjunction with the m onitoring and em issions anal yses, the technical basi s used to identify and evaluate reasonable progress for the Jarbidge W A

.

4.1.1 Air Quality Models

RMC utiliz e d two grid-b ased m odels to analy ze th e ef f

ects of haze-c ausin g particle s within the WRAP area. The Community Multi-Scale Air Q u ality (CMAQ) m odel provided visibility modeling forecasts for 2 018, the end of the first regional h aze planning period. The results of CMAQ modeling are used in identifying the 2018 reasonable progress goals (RPG). The Particulate Matter Source Attr ibution Tracking (PSAT) algorith m in the Comp rehensive Air Quality Mo del with Extensions (CA M x) m odel is used to as s e ss source apportionm ent, particula r ly f o r sulf ate a nd nitr ate pa rticle species, based on source area and source category, and to iden tif y those Class I ar eas that are affected by Ne vada em ission sources.

The PSAT algorithm applies n i trate-sulfate-ammonia chem istry to a sys t em of tracers, or “tags ”
, to track chem ical transform a tions, transport and re m oval of e m issions. Each source area (state or region) is as signed a tag that is used to track the em issions from each 36-k ilom e ter grid cell within th e s p ecified sou r ce area. E m issions fr om point, m o bile, area and fire (natural and anthropogen i c) sou r ce categories were tagged fo r each source area. The P S AT algorithm was also used, in a lim ited ap plic ation (i.e., no source area attri bution), to track natural and anthropogen i c species of organic aerosols at each Class I area. The organic aeroso l tracer tracked both prim ary and secondary organic aerosols (POA and SOA, respectively).

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-2Meteorological inputs and em issi on inventories were prepared fo r 2002, chosen as representative of the baseline period 20 00 through 2 004. These inputs were used in th e air quality m odel to predict fine particle m a ss a nd visibility. The m o del results for 2002 were comp ared with observed m e teorological and air quality data to evaluate m ode l perform a nce. Several configurations of the m e teorol ogical and air quality m odel we re evaluated to select the configuration that gave the best overall pe rform a nce for the WRAP region. Once model perform a nce was deem ed adequate, the current and future year em issions were processed through the em issions model, as discussed in Chap ter One. T h e m odeled em issions scenarios are described in Chapters One and Three.

4.1.2 Model Performance Evaluation

The objectiv e of the m o del perform a nce evalu a tion was to co mpare m odel-sim u lated concentrations with observed data to dete rm ine whether the model’s perform a nce was sufficiently accurate to justify using the m odel fo r sim u lating future conditions, as d i scussed in Chapter One. The m odel was comp ar ed to am bient data for both particulate m a tter and gaseous species, for an annual tim e period and for a large num ber of sites. The model was evaluated for both the worst and best visibility conditions. The “Final Report for the W R AP 2002 Visibility Model Perform a nce Evaluation” (To nnesen, et al, 2006 can be found at http://pah.cert.ucr.edu/aqm / 308/reports /final/2002_MPE_report_m a in_body_FINAL.pdf ) discusses in detail how the m odel perform a nce was evaluated.

The W R AP’s RMC found the m odel over-predicted the observed data on the cleanest days (i.e., the 20 percent best days or bestdays) and under predicted the obs erved data on the m o st polluted days (i.e., the 20 percent wors t days or worst days).

RMC has concluded that the CMAQ model cannot be used to forecast future coa r se matte r (CM) concentratio ns. Nevada has also deem ed model perform a nce was unacceptable for fine particulate m a tter (SOIL) on the worst days and n itrate on the best days. Model perfor m ance is discussed in greater detail below.

4.1.2.1 2002 Worst Days Performance

CMAQ model perform a nce can be roughly j udged by comp a r ing the m o del predicted concentration (left side of Figur e 4-1) agains t the m onitored concentration from the Interagency Monitoring of Protected Visual Environm ents (IMPROVE) monitor JARB1 (right side of Figure 4-1) for the worst days of 2002. As s hown, the model greatly under-predicts total m a ss and particularly CM (shown in gray on F i gure 4-1) . Sim ilar m o del under-prediction is observed across the WRAP region, thus the RMC has concl uded that the CMAQ model cannot be used to forecast futu re CM concentrations.

Figure 4-2 indicates the CMAQ mo del under predicts, as shown by negative percentages, all six

components of extinction for the worst days atJARB1. Neva da deem s model perform a nce for the worst days is acceptable for sulfate (-32 percent), nitrate (- 20 percent), organic m a tter (-40 percent), and elem ental carbon (- 33 percent), but is unacceptabl e for SOIL (-88 percent).

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-3FIGURE 4-1

CMAQ MODEL PERFORMANCE FOR JARB1 2002 W O RST DAYS

FIGURE 4-2

RELATIVE ERROR OF CMAQ MODEL PREDI C TION VERSUS IMPROVE DATA FOR JARB1 200 2 W O RST DAYS

- 100%

- 80% - 60% - 40% - 20% 0% 20% 40% 60% 80% 100%

S u l f a t

e N i t r a t e O M C E C S oi l C MRelative Error(%)

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-44.1.2.2 2002 Best Days Performance

Comp arison of the m ode l predicted concentration (left side of Fi gure 4-3) against the monitored concentratio n from the IMPROVE m onitor JARB1 (right side of Figur e 4-3) for the best days of 2002 shows much better agreem en t between total m a ss.

FIGURE 4-3

CMAQ MODEL PERFORMANCE FOR JARB1 2002 BEST DAYS

However, Figure 4-4 shows the m ode l produces m i xe d predictions for the best days at JARB1. Nevada deem s the m ode l perform a nce for the best days is acceptable for elem ental carbon (-33 percen t) and SOIL (-38 percen t), but is m a rginally acceptable for sulfate (+61 percen t) and organic m a tter (+60 percent). Model perform a nc e for nitrate (+175 percent) is unacceptable for the best days. As described above, RMC has concluded the CMAQ model cannot be used to predict future CM concentrations.

4.1.3 Weighted Emissions Potential Analysis

The W E P was developed as a screen ing tool for states to identify which source areas (e.g., states) have the po tentia l to con t ribu te to h a ze f o rm a tion at specific Class I areas, based on both the 2002 and 2018 em issions inventories, as discussed in Chapter One. W E P was used to investigate the attribution of sources of nitrogen oxides (NO x ), sulfur dioxide (SO 2 ), organic carbon (OC), elem ental carbon (EC), fine particulate m a tter (P MF) and coarse particulate m a tter (P MC). The results of th e W E P analyses are discussed below in section 4.4.

4.2 VISIBILITY MODELI NG RESULTS FOR 2018

Visibility m odeling results indica te projected visibility conditions for the Jarbidge W A , based on the PRP18a em ission inventory, will m eet th e URP for 2018 (i.e., 2018 pro j ected vis i bility conditions show better progr ess than the glidepath).

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-5FIGURE 4-4

RELATIVE ERROR OF CMAQ MODEL PREDI C TION VERSUS IMPROVE DATA FOR JARB1 2002 BEST DAYS

- 100%

- 80% - 60% - 40% - 20% 0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 200%

Su l f a t

e N i t r a t e O M C E C S o i l C MRelativeError(%)

4.2.1 2018 Visibility Projections for Jarbidge Wild erness Area

Table 4-1 lists the 2018 URP for the Jarbidge W A and the CMAQ visibility m odeling forecasts for 2018. The results of this m odeling will be u s ed in es tablishing RPGs for the Jarb idge W A

. The 2018 model forecas ts indicate J a rbidge W A will m eet th e 2018 URP for the 20 percen t worst days and will m a intain v i sib ility for the bes tdays in 20 18.

The 2018 modeling results of 11.05 d eciviews (dv) presented in Ta ble 4-1 and Figure 4-5 show an improvem e nt of 1.02 dv from the worst days baseline value of 12.07 dv for the Jarbidge W A using the U S EPA specific days m e thod. This resu lts in an improvem e nt of 4.1 percent over the 2018 URP value of 11.09 dv, or 104.1 percent toward the 2018 URP. This indicates that Nevada’s projected reasonable prog r e ss is be tter than the UR P. The visibility m odel projections are based on the 2018 prelim inary reasonable progre ss (PRP18a) em ission i nventory identified in Chapter Three. The 2018 PRP does not include all of Nevad a ’s Best Ava ilab l e Retrof it Technology (BART) e m ission contro ls, or all of adjacen t states ’ BART controls. Additional

em ission reductions due to the installation of BART and other contro ls under the RHR are anticipated to improve modele d visib ility forecas ts.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-6TABLE 4-1

SUMMARY OF MODEL-PREDICTED PROGRESS TOWARD 2018 UNIFORM RATE OF PROGRESS AT JARB1

20 Percent Worst Days 20 Percent Best Days

Mandatory Class I Federal

Area Wor s t Days Baseline (dv) 2018 URP (dv) 2018 Modeling

Results

(dv) CMAQ Modeling

Percent Toward

2018 URP Best Days Baseline (dv) Average 2018 Modeling

Results

(dv) CMAQ 2018 Modeling

Result

Less Than Baseline ? Jarbidge W ilderness Area 1 2

. 0 7 1 1

. 0 9 1 1

. 0 5 1 0 4

. 1 % 2

. 5 6 2

. 5 0 Y e s

FIGURE 4-5

CMAQ MODEL PR OJ ECTIONS I N HAZ E INDEX FOR JARB1 2018 W O RST DAYS

Figure 4-6 provides the species-specific extinc tion glide slopes in inverse m e ga m e ters and corresponding 2018 m o del projections for the worst days at JARB1 using the USEPA specific days m e thod. Table 4-2 presents these data gr aphically and identifies the 2018 URP, the m odelprojected 2018 extinction and the percentage of modeled progress from the baseline toward the 2018 URP. The values presented in Figures 4-5 and 4-6 are rounded to one decim a l place, while those in Tab l e 4-2 are presented to two decim a l places.

All components show extinction reductions from baseline conditions, except CM and Sea Salt extinctions. These two rem a in constant from the baseline period to 2018 because the em ission

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-7inventories f o r these components were held c onstant for the baseline period and the 2018 projection f o r the purposes of m odeling.

Projected 2018 extinctio n m eets the URP for all components except SO 4 and Soil, as shown in Figure 4-6 and indicated by m odeled extinction changes of greater th an 100 percent in Table 4-2. The projected SO 4 extinction of 3.34 Mm -1 achieves 80 percent of the 2018 URP value (3.17 Mm -1 ). The projected N O 3 extinction of 0.7 M m -1 shows an improvem e nt of 1000 percent toward the 2018 URP of 1.06 Mm -1

.

Recall that the RMC has indicated th e CMAQ m odel canno t be used to forecas t future CM concentrations, and NDEP has deem ed the m o del perform a nce for Soil on the worst days as unacceptable. The resu lts for these s p ecies are p r esented for infor m ational purposes.

FIGURE 4-6

CMAQ MODEL PROJ ECTIONS I N EXTINCTION

BY SPECIES FOR J A RB1 2018 WORST DAYS

TABLE 4-2

SUMMARY OF MODEL PRE D ICTED PROGRESS T O WARD SPECIES-SPECIFIC 20 18 W O RST DAYS UR P AT JAR B 1

Ext i n c t i o n ( M m -1 ) S u l f a te N i tr a t e Or g a n i c Ca r b on E l e m e n ta l Ca r b o n F i n e S o i l Co a r s e Ma s s S e a S a l t
Ba s e l i n e 4 1

. 1 1 0 .0 4 1 .6 5 2 .4 1 5 .4 7 0 .0 6 2 0 1 8 U R P 3 .1 7 1 .0 6 8 .4 9 1 .3 4 2 .1 5 5

. 2 0

. 1 3 Pr oj ec t e d 2 0 18 R P 3

. 3 4 0

. 7 8 .2 4 1 .1 2 2 .2 9 5 .4 7 0 .0 6
M o de l e d C h a n g e f r o m B a s e l i n e t o 2 0 1 8 U R P (% o f G o a l ) 8 0 % 1 00 0% 1 1 6 % 1 7 1% 46 % 0 % 0 %

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-8Figure 4-7 indicates the 2018 m odel- projected extinction for the be st days at JARB1, using the USEPA spe c ific days m e thod, is 2.50 dv, which is below the best days baseline average of 2.56 dv. These data ind i cate Nevada is forecast to m a in tain v i sib ility for the best days of 2018 at the Jarbidge W A

.

FIGURE 4-7

CMAQ MODEL PROJ ECTIONS I N HAZE INDEX FOR J A RB1 2018 BEST DAYS

4.3 SOURCE APPORTI O NMENT MODELING RESULTS

The PSAT a l gorithm in the CAMx model was de veloped to assess source apportionm e n t. The PSAT analysis was used to attribu t e particle sp ecies, particularly sulfate and nitrate, from specific sou r ce areas and source categories, as disc ussed earlier. Em issions from each state or region for point, m obile, area and fire sources were tagged and track ed. The PSAT modeling utilized the Plan02c and Base 18b em ission inventories.

4.3.1 Sulfate Sou rce Apportionment for Jarbidge Wilderness A rea
Figure 4-8 displays the 2002 and 2018 worst days particulate sulfate concentrations impacting the JARB1 monitor due to em issi ons from WRAP states. The chart provides details on the relative source contribution for each WRAP state during 2002 and 2018. The data ind i cate the overall SO 2 em ission sources for the worst days ar e from the states of Idaho, Oregon and Washington. Idaho’s contributi ons to sulf ate a r e prim arily f r o m natural f i re em ission s which were held constant from 2002 to 2018. Point sources also contribute signifi cantly to sulfate from Idaho. W a s h ington, Oregon, Nevada and California s how contributions to su lfate prim arily from point sources and natural fires.

Figure 4-9 shows the contributions to sulfate con centration from all m odeled source areas for the worst days of 2002 and 2018 at the JARB1 monitor. These charts show that source areas outside the dom ain and within the W R AP region have sub-equal contributions of approxim a tely 40 percent to year 2002 sulfate concentration at the JARB1 monitor for the worst days. Adding other source area contributions outside of the United States (i.e., Cana da, Mexico and Pacific

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-9Offshore) to the Outsid e Dom a in source area contributions suggests over 55 percent of the sulf ate con t r i butions to v i sibility impairm e nt at th e Jarbidg e WA are out side the jurisdiction of state or federal regulation.

FIGURE 4-8

SULFATE PSAT SOURCE REGI ON BAR CHART FOR WORST DAYS 2002 AND 2018

FIGURE 4-9

SULFATE PSAT REGI ONAL PIE CH ART FOR WORST DAYS 2002 AND 2018

Figure 4-10 displays the 2002 and 2018 best days’ particulate sulf ate concentrations impacting the JARB1 monitor due to em issi ons from WRAP states. The chart provides details on the relative source contribution for each WRAP state during 2002 and 2018. The data ind i cate the dom i nant WRAP source area contribution for the be st days is Nevada. Lesser con t rib u tions a r e due to em issions from Idaho, Oregon and Califor nia. Point sources are the dom inant source catego r y.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-10Figure 4-11 show the contributions to sulfate con centration from all m odeled source areas for the best days of 2002 and 2018 at the JARB1 m onitor. These charts show that W R AP source areas contribute less than a third to th e su lfate concentration at the J A RB1 monitor for the best days. Source areas outside the jurisd icti on of state or federal regulati on and/or control (i.e., Outside Dom a in, Canada, Mexico and Pacific Offshore) c ontr i bute m o re tha ttwo thirds to th e sulf ate concentratio n at the JARB1 m onitor.

FIGURE 4-10

SULFATE PSAT SOURCE REGI ON BAR CHART FOR BEST DAYS 2002 AND 2018

FIGURE 4-11

SULFATE PSAT REGI ONAL PIE CHAR T FOR BEST DAYS 2002 AND 2018

4.3.2 Nitrate Sou rce Apportionment for Jarbidge Wilderness A rea
Figure 4-12 displays the particulate nitrate concentrations for 2002 and 2018 worst days for WRAP source areas at the JARB1 monitor. Th e chart provides details on the relative source contribution of each W R AP state during 2002 an d 2018. The data ind i cate the dom inant W R AP source area contributions for the worst days ar e from Idaho, Utah and Nevada. Calif ornia,

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-11Oregon and Washington had lesser cont ributions to nitrate concentra tions at the JARB1 m onitor. Mobile sou r ce em issions are th e dominant sou r ce catego r y for NO x e m issions, although area

source em issions are significant for Idaho. Poin t source em issions from I d aho, Nevada and Utah are also important contributors to the m odeled nitrate concentration fo r the worst days of 2002 and 2018.

FIGURE 4-12

NITRATE PSAT SOURCE RE GION BA R CHART FOR WORST DAYS 2002 AND 2018

Figure 4-13 shows the contributions to nitrate co ncentration f r om all m o deled source areas for the worst days of 2002 and 2018 at the JARB1 mon itor. The pie charts show the WRAP region contributes more than three qua rters to 2002 nitrate concentrati on at the JARB1 monitor for the worst days of 2002. The W R AP contribution drops to m o re than two thirds for 2018. Outside Dom a in sources com b ined with contributions fr om Mexico, Canada and Pacific Offshore areas contribute nearly a quarter to sulfate concentrations at the JARB1 m onitor in 2002. Contributions from these sources in crease to nearly a third for 2018.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-12FIGURE 4-13

NITRATE PSAT RE GIONAL PIE CHART FOR WORST DAYS 2002 AND 2018

Figure 4-14 displays the 2002 and 2018 best days’ particulate nitr ate concentrations impacting the JARB1 monitor due to em issi ons from WRAP states. The chart provides details on the relative source contribution for each WRAP state during 2002 and 2018. The data ind i cate the dom i nant WRAP source area contribution for the best days is the St ate of Nevada with significant contributions from California and Idaho. Oregon, Ut ah and Washington show lesser contributions. Mobile sources are the dom inant source category, except in Nevada, where point and m obile sources have sub-equa l co ntribu tion to nitr ate con c entr ation at the JARB1 monitor. Area sources in Idaho also contribute significantly.

FIGURE 4-14

NITRATE PSAT SOURCE RE GION BA R CHART FOR BEST DAYS 2002 AND 2018

Figure 4-15 displays the contributio ns to nitrate concentration from all m o deled source areas for 2002 and 2018 best days at JARB1. The pie charts indicate WRAP states contribute approxim a tely two thirds to the n itr ate concentr ation at the JA RB1 m onitor with th e re m a ining nitr ate impact due to Ou tside Dom a in, Canada and Pacific Offshore sources.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-13FIGURE 4-15

NITRATE PSAT RE GIONAL PIE CH ART FOR BEST DAYS 2002 AND 2018

4.3.3 Source Apportionment for Other Class I Areas

The PSAT s ource apportionm ent m o deling results were eva l u a ted to d e te r m ine which Class I areas in adjacent s t ates m i ght be affected by em i ssions from Nevada sources. Table 4-3 presents the resu lts o f this evalu a tion f o r sulf ate ex tinc tio n. The table identif i es th e rank and p e rcen tage of

the tota l modeled co ncentration due to SO 2 em issions from sources within Nevada to the IMPROVE monitors rep r esenting all Class I areas in the five adjacen t states. The ran k and percentage contribution is base d on contributions from all m o de led source areas. The bolded values are th e highes tpercentage contribution to v i sibility impairm e nt at Class I areas in each of the five adjacent s t ates d u e to em issions from Ne vada sources for the worst days projected for 2018.

Exam ination of the best days 2018 rank and contri bution identifies the m a xim u m contribution to sulf ate ex tin ction due to em issi ons from Nevada sources occurs at SAWT1 located in the Sawtooth Wilderness Area, with a rank of 4 and a contribution of 7.2 percent. For the worst days, Nevada’s m a xi m u m contribution occurs at ZION1 located in Zion N a tiona l Park with a rank of 6 and a contribution of 5.6 percent. F i gure 4-16 shows SO 2 em issions from sources outside the modeling dom a in, which are beyond th e jurisdiction of Unite d States regulatory agencies and uncontrollable, contribute nearly eight tim es as much as Nevada sources to sulfate extinction on the 2018 best days at the Sawtoot h W ilderness Area. Figure 4-17 shows the two source areas with the greatest contributions to sulfate extinction on the 2018 worst days to Zion National Park are Outsid e Dom a in and Pacific O ffshore. Sources in Mexico are the fourth larges t con t r i butor while the m a jority of em issi ons from the third larges t so urce area co ntribu tor are natural.

Table 4-4 presents the results of the source appo rtionm ent m o deling for nitrate extinction at the Class I areas in adjacent states. Exam inati on of the best days 2018 rank and contribution identifies th e m a xi m u m contribution to nitrate ex tinction due to em issions from Nevada sources

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-14occurs at JOSH1 located in Joshua T r ee Nationa l Park, with a rank of 4 and a contribution of 12.4 percent. For the worst days, Nevada’s m a xi mum contribution occurs at BLIS1 located in Bliss Sta t e P a rk (m onitor location f o r

Desola tion W ilderness Area and Mokelum n e W ilderness Area) with a rank of 3 and a contribution of 20.0 percent. The bolded va lues in this table represent the m a xi m u m visibility impacts at the Class I areas in adjacent states due to Nevada’s

em issions for the worst days projected for 2018.

TABLE 4-3

NEVADA’S SULFATE EXTINC TI ON C ONT R I BUTION T O CLASS I AREAS OUT SIDE OF NEVADA

I m pa ct R a n k I m

p ac t R a nk I m pa ct R a n k I m

p a

c t R a nk

G R C A 2 H an ce C a m p 3. 1% 4 2

. 8 % 5 6. 0% 6 2. 8% 6 I K B A 1 I ke ' s B ack bo ne 4. 2% 6 2

. 6 % 8 3. 3% 8 1

. 5 % 1 0 S I

A N 1 S i e r ra A n c h a 2

. 6 % 9 1. 6 % 9 3

. 1 % 8 1. 5% 9 SY C A 1 S yca m o r e C a nyon 6. 3% 3 3

. 1 % 6 5. 6% 6 2

. 5 % 8 TO N T 1 T on t o 2. 2% 7 1

. 3 % 9 2. 7% 8 1

. 3 % 9

B L I S 1 B l i s s St at e Pa r k 3. 0% 4 3

. 1 % 4 4. 8% 5 4. 4% 5 D O M E 1 D om e L a nds 6. 3% 3 5

. 3 % 3 2. 0% 7 1

. 6 % 8 H O O V 1 H o o v e r 2

. 3 % 4 2. 2 % 4 3

. 0 % 6 2. 6% 6 J O SH 1 J o s h u a T r ee 6. 6% 4 4

. 0 % 4 1. 7% 6 1

. 2 % 6 KA I S 1 K a i s e r 1

. 6 % 4 1. 5 % 4 2

. 9 % 6 2. 4% 6 LA V O 1 L as s e n V o l c a n i c 2. 7% 4 3

. 0 % 4 2. 1% 7 2

. 3 % 7 LA B E 1 L ava B e ds 3. 5% 4 3

. 8 % 4 3. 1% 7 3

. 2 % 7 SA G A 1 S an G a b r i e l 2

. 4 % 4 2. 0 % 4 1

. 0 % 7 0. 7% 8 S A G O 1 S a n G o r g on i o 6. 9% 4 4

. 1 % 5 1. 5% 6 0

. 9 % 6 S E Q U 1 S e quo i a 3. 1% 4 2

. 2 % 5 2. 8% 5 2

. 0 % 5 Y O SE 1 Y o s e m i t e 2

. 9 % 6 2. 4 % 7 1

. 9 % 4 1. 6% 4

C R M O 1 C r a t e

r s of t h e M o o n 3. 5% 7 4

. 1 % 6 1. 6% 9 1

. 9 % 9 S A W T 1 S a w t o o t h 5

. 9 % 5 7

. 2 % 4 2

. 2 % 8 2. 5% 8

C R L A 1 C r a t e

r L a k e 0. 8% 7 0

. 8 % 7 1. 2% 7 1

. 4 % 7 H E C A 1 H el l s C a n yon 1. 2% 8 1

. 6 % 5 3. 2% 7 4. 0% 6 S T A R 1 S t a r k

e y 1. 6% 7 1

. 9 % 7 1. 7% 7 2

. 0 % 7

B R C A 1 B r y c e C a n yon 3. 8% 3 4

. 1 % 4 8. 1% 5 4

. 8 % 6 C A P I 1 C ap i t o l

R e e f 2. 4% 8 2

. 5 % 8 6. 0% 6 3

. 9 % 6 Z I O N 1 Z i o n 5

. 4 % 3 4

. 9 % 3 9

. 0 % 4 5. 6% 6 Ut a h IM P R O V E Si

t e C o d e I M P R OV E S ite N a m e Ar i z o n a

Ca l i f

o r

n i a

Id a h o

O r e gon S u l f at

e E x t i nct i on C o nt ribu t i on d u e t o N e va d a E m i s s i o n s B e s t D a ys W o r s t D a ys 200 2 2 018 20 0 2 2 018

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-15FIGURE 4-16

SULFATE PSAT SOURCE REGI ON BA R CHART FOR BEST DAYS 2002 AND 2018 AT SAWTOOTH W I LDE R NESS AREA

FIGURE 4-17

SULFATE PSAT SOURCE REGI ON BA R C HART FOR W O RST DAYS 2002 AND 2018 AT ZION NATIONAL PARK

Figure 4-18 shows NO x em issions from California sources ar e the dom inant contributor to nitrate extinction on the 2018 best days at Joshua Tr ee National Park, followed by sources outside the modeling dom a in and Pa cific offs hore sources. F i gure 4-19 shows NO x e m issions from California sources are the dom inant contributor f

o r the 2018 worst days, followed by em issions from sources outside the m odeling dom a in to nitrate extin ction at the Desolation W ilderness Area.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-16TABLE 4-4

NEVADA’S NITRATE EXTINC TI ON C ONT R I BUTION T O CLASS I AREAS OUT SIDE OF NEVADA

Im p a c t R a n k Im p a

c t R a n k Im p a

c t R a n

k Im p a

c t R a n k

G R C A 2 H a n c e C a m p 5

. 8% 5 5

. 8 % 5 2. 2% 6 2

. 8 % 6 I KB A 1 I ke ' s B a ck

bo ne 2

. 8% 6 3

. 2 % 6 1. 6% 8 2

. 4 % 8 S I

A N 1 S i er ra

A n ch a 2

. 3 % 7 2

. 7 % 7 2

. 6 % 5 3

. 9 % 5 SY C A 1 S y c a m o r e C a ny on 3

. 4% 6 4

. 3 % 6 3. 4% 6 4. 3 % 6 T O N T 1 T o n t o 2

. 4% 6 2

. 7 % 6 1. 5% 7 2

. 1 % 7

B L I S 1 B l i s s S t at e Pa r k 4

. 2% 4 4

. 9 % 4 16

. 3 % 3 20

. 0 % 3 D O M E 1 D o m e L a n d s 8

. 6 % 3 9

. 6 % 3 1

. 8 % 4 2

. 3 % 4 H O O V 1 H o o v er 4

. 3% 3 4

. 8 % 3 7. 7% 3 8

. 3 % 3 J O S H 1 J os hu a T r e e 11

. 0 % 4 1 2

. 4 % 4 0

. 6 % 4 0

. 6 % 4 K

A I S 1 K a i s e r 2

. 3 % 4 2

. 7 % 4 2

. 9 % 6 4

. 0 % 4 LA V O 1 L a s s e n

V o l c a n i c 3

. 6% 4 4

. 8 % 4 2. 4% 6 3

. 0 % 5 LA B E 1 L a v a

B e ds 3

. 7% 5 4

. 4 % 5 6. 6% 4 8

. 0 % 4 S A GA 1 S a n Ga b r

i e l 2

. 0 % 4 2

. 4 % 4 0

. 3 % 6 0

. 4 % 5 S A G O 1 S a n G o r g o n i o 5

. 4% 4 6

. 4 % 4 0. 3% 5 0

. 5 % 5 S E Q U 1 S e q u o i a 2

. 7% 4 3

. 6 % 4 1. 6% 4 2

. 0 % 4 Y O S E 1 Y o s e m i t e 1

. 8% 4 2

. 2 % 4 3. 8% 4 5

. 1 % 4

C RM O 1 C r a t e

r s o f t h e M o o n 5

. 8% 8 6

. 6 % 5 2. 3% 9 2

. 7 % 8 S A W T 1 S a w t o o t h 6

. 5 % 5 7

. 5 % 5 3

. 1 % 7 3. 2 % 6

CR L A 1 C r a t e

r L a k e 1

. 2% 6 1

. 5 % 7 1. 6% 7 2

. 0 % 7 H E CA 1 H el l s C a ny on 2

. 0% 8 2

. 4 % 8 4. 8% 6 5. 5 % 5 S T A R 1 S t a r k e y 3

. 2% 6 3

. 7 % 6 3. 7% 7 4

. 5 % 6

B R C A 1 B r y ce C a ny on 4. 0 % 4 4

. 0 % 5 8

. 8 % 4 8. 8 % 4 C A PI 1 C a p i t o l R e e f 2

. 9% 5 2

. 9 % 6 5. 2% 4 5

. 4 % 5 Z I O N 1 Z i o n 6

. 2 % 4 6

. 2 % 5 8

. 1 % 4 7

. 9 % 4 Ca l i f

o r

n i a

Id a h o

Or e g o n

Ut a h 20 18 IM P R O V E Si t e C o d e I M P R O V E Si t e Na m e Ar i z o n a Ni t r at e E x t i nc t i o n C o n t r i bu t i o n d u e t o N ev a da E m i s s i o n s B e st D a ys W o rs t D a ys 2 0 0 2 20 18 20 02

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-17FIGURE 4-18

NITRATE P S AT SOUR CE RE GION BAR CHART F O R BEST DAYS 2002 AND 2018 AT JOSHUA TRE E NATIONAL PARK

FIGURE 4-19

NITRATE P S AT SOUR CE RE GION BAR CHART F O R WORST DAYS 2002 AND 2018 AT DESOLATION W I LDERNESS ARE A

4.3.4 Organic Aerosol Source Apportionment for Jarbidge Wilderness Area

The PSAT a l gorithm wa s also used in a lim ited application to track na tural and anthropogenic species of organic aeroso ls at each Class I area. S ource area (e.g., no state or region al) attribution was not perform e d for the aeroso l so urce appo rtionm ent. The organic ae rosol trac er tracked both POA and SOA. POAs are prim ary organics resulting form direct organic aerosol

em issions from anthropogenic and biogenic source s. SOAs are further subdivided to include anthropogen i c second ary organics res u lting form arom atic VOCs such as xylene, to lu ene and cresols, as w e ll as biogenic secondary organics resulting from biogenic V O Cs such as terpenes. The purpose of the organ i c aerosol tracer tool is to investigate the contribu tion of prim ary and secondary anthropogenic and biogenic sources on m odeled OC at Class I areas.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-18A wide variety of sources contribute to POAs, from cooking of m eat to diesel em issions and

com bustion byproducts f r om wood and agricultura l burning (e.g., em issions from area sources, on-road and of f

-road m o bile sou r ces, f ugitive dus t source s an d f i re sourc e s ). Nevada’ s POA

em issions inventory is dom i nated by natural fire em issions as described in Chapter 3 (see 3.8.4) and shown in Figure 3-17 and Table 3-10.

4.3.4.1 Organic Aerosol PSAT for Worst Days 2002 and 2018

Figure 4-20 displays the monthl y organic aerosol concentratio n for the baseline period (2000 through 2004) and 2018 in pairs for the worst days at the JARB1 m onitor. The organic aerosol PSAT tracks anthropogenic SOA (in red) , biogenic SOA (in sky blue) and anthropogenic/biogenic POA (in bl ue). The chart provides deta ils on the relativ e anthropogenic and biogenic concentration for each month of the baseline period and the f u ture con t ribution in 2018. None of the worst days for the baseline pe riod or for 2018 occurred during the winter or early spring months of Ja nuary, February or March.

FIGURE 4-20

MONTHL Y ORGANIC AEROSO L PSAT BAR CHART FOR WORST DAYS 2002 AND 2018

4.3.4.2 Organic Aerosol PSAT for Best Days 2002 and 2018

Figure 4-21 displays the monthl y organic aerosol concentratio n for the baseline period (2000 through 2004) and 2018 for the best days at the JARB1 monitor. None of the best days during the baseline period or for 2018 occurred in the summer or early fall m onths of June, July, August, Septem ber or October.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-19FIGURE 4-21

MONTHLY ORGANIC AEROSO L PSAT BAR CHART FOR BEST DAYS 2002 AND 2018

4.3.4.3 Organic Aerosol PSAT for All Days 2002 and 2018

Figure 4-22 displays the monthly organic aerosol concentrations for the baseline period (2000 through 2004) and 2018 for all days at the JARB 1 m onitor. This figure shows the strong seasonal influence of biogenic and fire em issions on visibility at the Jarb idge W A . The bar chart indicates biogenic SOA (in sky blue) is the dom inan t source of organic aero sol for all months of the year and it occu rs at much higher concentrati ons during the summ er a nd early fall months of June, July, August, Septem ber and October when temp eratures are warm er and vegetative growth is most prolific. Signi ficant POA concentrations are i ndicative of the contribution of natural fire em issions occurring in the m onths of July, August, Septem ber and to a lesser degree October.

4.4 WEIGHTED EMISSI ONS POTE NTIAL ANALYSES RESULTS

The W e ighted Em issions Potentia l (WEP) tool is an analysis techniqu e that iden tif ie s the predom inant em ission source regions contributin g haze-forming pollu tants at each Class I area based on 5 years of historical m e teorology for both the 20 percent best and worst days, as described in Chapter One.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-20FIGURE 4-22

ORGANIC AEROSOL PSAT BAR CH ART FOR ALL DAYS 2002 AND 2018

The W E P analysis resu lts in tw o graphical displays of the data: W E P maps of nor m a lized, weighted em issions; and W E P bar charts of nor m a lized, residence tim e - and distance-weighted annual em issions. The m a ps show t h e location of the Jarbidge W A with a green star surrounded by 100 km and 200 km radius concentric circles. The areas shaded in diffe rent colors identify those 36 km grid cells w ith the potential of contributing em issions to JARB1 for the worst days in 2018. Geographical regions and individual grid cells with greater pot ential to impact the Jarbidge W A are easily distinguis he d in the m a ps by the dark er shaded g r id ce lls, wh ile the white areas denote those grid cells with neg ligib le em ission poten tia l.

Geographic source areas and source catego r ies are also easily distinguis hed on the bar charts, which identif y twelve source ca tegor ies: windb lo wn dust, f ugitiv e dust, ro ad dust, of f

-road mobile, on-road m obile, off-shore, oil and gas, ar ea, biogenic, natural fire, anthropogenic fire and point. Two different m o deling sim u lation em i ssion scenarios (using the Plan02d and PRP18a

em ission inventories) were used to produce the WEP m a ps. Only the PRP18a em ission scenario

m a ps for the worst days are presented below.

4.4.1 Nitrogen Oxides – Regional WEP Analysis for 2018 Worst Days

Figure 4-23 shows the norm alized regional cont ributions to residence tim e- and distanceweighted NO x em issions for JARB1. The W E P bar charts, shown as Figure 4-24, display

norm a lized (unitless), residence tim e- and distance-weighted 2018 annual NO x e m issions values, by em issions source region.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-21FIGURE 4-23

REGIONAL NO x W E P FOR 2018 WORST DAYS

Exam ination of Figures 4-23 and 4-24 show s the point source contributions from the industrialized portions of northern Nevada and al ong the Snake River Plain of Idaho, as well as more distance areas in southern Nevada and por tions of California, in cluding the Bay Area, Central Valley and Los Angeles area to 2018 NO x concentration at JARB1. These figures also show the contribution of m obile sources, both on-road and of f-roa d, from the m a in transportation corridors and population centers along I-80 in Nevada and Ut ah, I-84 in U t ah, Idaho, and Oregon, and I-5 in California to NO x e m issions at JARB1.

4.4.2 Sulfur Oxid es – Regional WEP Analysis for 2018 Worst Days

Figure 4-25 shows the norm alized regional cont ributions to residence tim e- and distanceweighted S O 2 em issions for JARB1. The W E P bar charts, shown as Figure 4-26, display

norm a lized (unitless), residence tim e- and distance-weighted annual SO 2 em issions values, by

em issions source region. Exam ination of Figures 4-25 and 4-26 shows the large point source contributions from the industrialized portions of northeastern Nevada and along the Snake River Plain of Idaho, as well as m o re distance ar eas in the Bay Area of California to 2018 S O 2 concentration at JARB1. These figures also show the contribution of natu r a l f i res in Id aho to SO 2 e m issio n s at JARB1.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-22FIGURE 4-24

SOUR CES AND ARE A S OF POT E NTIAL HAZE-CAUS ING NO x EMISSIONS FOR J A RB1 2002 AND 2018 WORST DAYS

4.4.3 Organic Carbon – Regional WE P Analysis for 2018 Worst Days

Figure 4-27 shows the norm alized regional cont ributions to residence tim e- and distanceweighted organic carbon (POA) e m issions for JARB1. The WEP bar charts, shown as Figure 4- 28, display norm a lized (unitless), residence tim e- and distance-weighted annual OC em issions values, by em issions source region. Exam ination of Figures 4-27 and 4-28 shows the large, natural fire source contributions from diffuse areas of California, Idaho, northern Nevada, Oregon, Utah and W a shington to 2018 OC concentra tion at JARB1. The s e figures also show the contribution of area sources from population cen ters along the Snake River Plain of Idaho, the Central Valley and Bay Area of California, the P o rtland area of Oregon and the Seattle area of Washington.

4.4.4 Elemental Carbon – Regional WE P Analysis for 2018 Worst Days

Figure 4-29 shows the norm alized regional cont ributions to residence tim e- and distanceweighted prim ary EC e missions for JARB1. Th e WEP bar charts, shown as Figure 4-30, display

norm a lized (unitless), residence tim e- and di stance-weighted annual primary EC em is sions values, by em issions source region. The contributi on distribution shown by EC is very sim ilar to that shown by OC. Exa m ination of Figures 4-29 and 4-30 shows the large, natural fire-source contributions from diffuse areas of Califor nia, Idaho, northern Ne vada, Oregon, Utah and Washington to 2018 EC concentration at JARB1. Figure 3-22 in Chapter Three m o re clearly shows that the EC e m issions in Nevada are prim ar ily du e to n a tural fire ev ents. These figures also show the contribution of area and off-road mobile source s from population centers along the Snake River Plain of Idaho, the Central Valley and Bay Area of Californi a, the Portland area of Oregon and the Seattle area of W a shi ngton.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-23FIGURE 4-25

REGIONAL SO 2 W E P FOR 2018 WORST DAYS

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-24FIGURE 4-26

SOUR CES AND ARE A S OF POT E NTIAL HAZE-CAUS ING SO 2 EMISSIONS FOR J A RB1 2002 AND 2018 WORST DAYS

FIGURE 4-27

REGIONAL ORGANI C CARBON WEP FOR 2018 W O RST DAYS

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-25FIGURE 4-28

SOUR CES AND ARE A S OF POT E NT IAL HAZE-CAUS ING OR GANIC

CARBON EMISSIONS FOR JA RB1 2002 AND 2018 WORST DAYS

FIGURE 4-29

REGIONAL ELEMENTAL CARBON W E P FOR 2018 WORST DAYS

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-26FIGURE 4-30

SOURCES AND ARE A S OF POT E NT IAL HAZE-CAUS ING ELEM ENTAL CARBON EMISSIONS FOR JA RB1 2002 AND 2018 WORST DAYS

4.4.5 Particulate Matter Fin e – Regional WEP Analysis for 2018 Worst Days

Figure 4-31 shows the norm alized regional cont ributions to residence tim e- and distanceweighted P M F em issions for JARB1. The W E P bar charts, shown as Figure 4-32, display

norm a lized (unitless), residence tim e- and dist ance-weighted annual PMF em issions values, by

em issions source region.

Exam ination of Figures 4-31 and 4-32 shows the large windblown dust-source contributions from diffuse areas of southern Idaho, norther n Nevada, eastern Oregon and northern U t ah to 2018 PMF concentration at JARB1. These figures also show lesser fugitive dust contributions from the sam e diffuse areas of Idaho, Neva da, Oregon and Washington, as well as the contribution of area sources from population cen ters along the Snake River Plain of Idaho, the Central Valley and Bay Area of Californ ia, and the Portland area of Oregon.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-27FIGURE 4-31

REGIONAL PARTICULATE MATTER FINE WEP FOR 2018 W O RST DAYS

FIGURE 4-32

SOUR CES AND ARE A S OF POT E NTIA L HAZE-CAUS ING PARTICULATE

MATTER F I NE EMISSIONS FOR JARB1 200 2 AND 201 8 W O RST DAYS

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-284.4.6 Particulate Matter Coarse – Region al WEP Analysis for 2018 Worst Days

Figure 4-33 shows the norm alized regional cont ributions to residence tim e- and distanceweighted P M C e m issions for JARB1. The W E P bar charts, shown as Figure 4-34, display

norm a lized (unitless), residence tim e- and dist ance-weighted annual PMC em issions values, by

em issions source region. The cont ribution distribution shown by PM C is very sim ilar to that shown by PMF. Exa m ination of Figures 4-33 and 4-34 shows the large w i ndblown dust source contributions from diffuse areas of southe rn Idaho, northern Nevada, eastern Oregon and northern Utah to 2018 PMF concentration at JA RB 1. These figures als o show lesser fugitive dust contributions from the sam e diffuse areas of Idaho, Nevada, Oregon and W a shington, as well as the contribution of area sources from population centers along the Snake River Plain of Idaho, the C e ntral Valley and Bay Area of Califor nia, and the Portland area of Oregon. Road dust is an important contributor fr om areas of California and Idaho.

FIGURE 4-33

REGIONAL PARTICULATE MATTER COARSE W E P FO R 2018 WORST DAYS

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-29FIGURE 4-34

SOUR CES AND ARE A S OF POT E NTIA L HAZE-CAUS ING PARTICULATE MATTER COARSE EM ISSIONS FO R JARB1 2002 AND 2018 W O RST DAYS

4.5 VISIBILITY AND SOURCE APP O RTIONMENT MODELING SUMMARY

Results of th e CMAQ visibility m odeling f o reca st s indic a te th e Jarbidg e W A will m e et the URP for 2018 for the worst days with no degradation of best days.

Results of the PSAT source apportionm ent m odeli ng identify the source areas contributing to sulfate and n itrate ex tin ction at th e JA RB1 m onitor. Table 4

- 5 lists the f o u r source are a s with the highest contribution of SO 2 and NO x to JARB1 based on the source apportionm ent modeling. The area with the greates tsulfate con t ribu ti on is Outside Dom a in (or boundary cond itions ), which has contributions four tim es greater th an any other sou r ce area. Po int, area and natural fire sources all contribute approxim a tely one-third to visibility im pair m e nt at the Jarbidge W A

. Nevada is not a significant contribu tor of sulfate at the Jarb id ge W A

. Idaho, closely followed by Outside Dom a in, is the largest source area contri butor to nitrate at JARB1. Ne vada and Utah also contribute significan tly to m o deled nitrate concentrations in the Jarbidge W A . Point, mobile and area sources c ontribu te su bequally to nitr ate, with a lesse r contribution from natural fire sources.

Boundary conditions represent the b ackground concentration s of pollu tan t s that enter the edge of the m odeling dom a in. Em issions can be transpor ted great distances and repres ent international

em issions beyond the portions of Canada and Me xico that lie within the m odeling dom a in. Boundary conditions represent em issions from s ources beyo nd the ju risd iction of United States regulatory agencies and are uncon trollable for the purposes of Nevada’s regional haze SIP.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-30TABLE 4-5

SUMMARY OF 2018 MODEL RESULTS FOR JARBIDGE W I LDERNESS AREA

S o ur c e s * 1s t 2 n d 3 r d 4 t h So ur c e s * 1 s t 2 n d 3 r d 4 t h O u ts id e Do m a in I d a h o O r e g o n Pa ci f i c O f fs h o re I d a h o Ou t s i d e Do m a i n Ne v a d a Ut a h

4 3

. 8 % 1 0. 3 % 7

. 2% 6. 9% 30

. 3 % 2 7

. 5% 1 3

. 1 % 1 0. 6 %

* O u ts id e D o m a in n o t in c l u d e d in p i e c h a r ts P o in t S o ur c e s Mo b i l e S o u r c e s N a t u ra l F i re S o ur c e s A r ea So ur ce s 20 18 Su l f a t e P S A T - 2 0 % W o r s t D a y s 4 R e g i o n s w i t h Gr ea t e s t C o n t r i bu t i on t o Ja r b i d ge 2 0 1 8 Ni t r a t e P S AT - 2 0 % W o r s t D a y s 4 R e g i o n s w i th Gr e a

te st C o n t ri

b u tio n t o J a rb id g e

Table 4-6 lists the 2002 to 2018 change in m odeled particulate sulfate and nitrate concentrations at the Jarbidge W A fo r the worst days. The 2018 PSAT modeling forecasts overall decreases in total sulfate and nitrate con centrations (i.e., “Total SO 4 ” and “Total NO 3 ” colum n s of Table 4-6) at the JARB1 m onitor. However, the m odeled c ontributions to sulfate at JARB1 due to Nevada sources (NV SO 4 colum n ) increased b y 14 percen t, while m o deled nitrate contributions due to Nevada sources (NV NO 3 colum n ) decreas ed by 1 2 percen t. The PSAT modeling used the Plan02c and Base18b em ission inventorie s, as discussed in C h apter One.

TABLE 4-6

CHANGE I N WORST DAYS MO DELED CONCENTRATIONS OF SUL F ATE AND NI TRATE

Cl a s s I

Ar e a Ye a r To t a l SO 4 (u g / m 3 ) NV S O 4 (u g / m 3 ) NV Sh ar e SO 4 NV [S O 4 ] Ch a n g e T o ta l NO 3 (u g / m 3 ) NV NO 3 (u g / m 3 ) NV Sh a r e NO 3 NV [N O 3 ] Ch a n g e

20 02 0

. 52 9 0

. 0 24 1 4

. 6 % 0

. 3 08 0. 03 58 11

. 6 %

20 18 0

. 50 7 0

. 0 27 5 5

. 4 % + 14 % 0

. 2 40 0. 03 14 13

. 1 %

- 1 2 % Ja r b i d g e W ild e r n e s s Ar e a

Figure 4-35 summarizes the Ne vada Plan02c and Base18b SO 2 inventories, while Figure 4-36 summarizes the Nevada Plan02d and PRP18a SO 2 inventories. Figures 4-37 and 4-38

sum m a rize the sam e data for NO x .

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 4-31FIGURE 4-35

NEVADA S O 2 PLAN02 c AND BAS E 18b EMI SSI ON I NVENT OR Y COMP ARI S ON

FIGURE 4-36

NEVADA S O 2 PLAN02 d AND PRP 18a EMI SSI ON I NVENT OR Y COMP ARI S ON

NEVADA REGI ONAL HAZE S T ATE I M PLEMENTATI ON PLAN, October 2009 4-32FIGURE 4-37

NEVADA NO x PLAN02c AND BASE18b EMI SSI ON I NVENT OR Y COMP ARI S ON

FIGURE 4-38

NEVADA NO x PLAN02d AND P R P18a EMI SSI ON I NVENT OR Y COMP ARI S ON

NEVADA REGI ONAL HAZE S T ATE I M PLEMENTATI ON PLAN, October 2009 4-33The projected 2018 em is sions inventories for both SO 2 and NO x show substantial overall reductions from the 2002 baseline invent ories. However, the PRP18a SO 2 projected inventory does not show as great reductions from 2002 for point sources as the Base18b and less total SO 2 reductions. For NO x e m issions, the total projected reductions are ve ry sim ilar, w ith a slight reduction in the PRP18a pointsource projection.

Com p arison of the Plan02d and PRP18a em i ssion inventories shows Nevada’s total SO 2
em issions decreased by 33 percent from the baseline period to 2018, while SO 2 point source

em issions decreased by 44 percent (see Tabl e 3

- 7). Sim ilarly, N e vada’s tota l N O x em issions decreased by 17 percent from the baselin e to 201 8, w h ile N O x point source em issions increased by 13 percent (see T a ble 3-8).

The projected overall particulat e sulfate and n itrate concen tra tion reductions at JARB1, shown on Table 4-6, are due to Nevada ’s and regional reductions of SO 2 and NO x em issions. Organic aerosol PSA T results identify prim ary and second ary biogenic organic aerosol em issions as the dom i nant contributor to projec ted O C concentrations at JAR B 1 for 2018. These results also indicate prim ary organic aerosol em issions du e to wildland fire are seaso n ally s i gnificant.

Regional W E P analyses appear to co nfirm the i m portant contributions of projected sulfate and nitrate em issions from point sources in Idaho a nd Nevada, as well as the influence of nitrate

em ission from m obile sources in th e states adjacent to Nevada to visib i lity im pairm e nt at JA R B 1 in 2018. These analyses also indicate the signi ficant contributions of natural sources due to natural fire em issions of OC and EC and windblown dust em i ssions of PMF and PMC to visibility im pairm e nt at JA R B 1

. The results of the projected 2018 visibility and source apportionm ent m o de ling indicate the RPG for the Jarb idge W A wil l exceed the URP and identifies Nevada point sou r ces of SO 2 , as well as point and m obile sources of NO x , as source area candidates for consideration of additional
contro l m e asures during future reg i o n al haze p l anning period s.

NEVADA REGI ONAL HAZE S T ATE I M PLEMENTATI ON PLAN, October 2009 4-34