## Chapt er Six – Reas onable Progr e s s for the Jarbidge Wilderness Area

6.1 INTRODUCTION

6.2 STEPS FOR DEVELOPING REAS ONABLE PROGRESS GOALS

6.3 ESTABLISHING BASELINE AND NATURAL VISIBILITY CONDITI ONS

6.4 DETERMINING THE UNIF O RM RATE OF PROGRESS

6.5 IDENTIFYING THE MEAS URES TO ACHIEVE THE UNIFORM RATE OF PROGRESS

6.5.1 Key Pollutants and Sources of Impairm e nt 6.5.2 Em issions Reduction s du e to Exis ting Air Pollu tio n Control M easures 6.5.2.1 Federal R u les 6.5.2.2 Consent Decrees 6.5.2.3 Other Air Pollution Control Measures 6.5.3 Resulting Improvem e nt in Visibility



### 6.6 ESTABLI S HING REASONABLE PROGRESS FOR NEVADA

6.7 DEMONS TRATION THAT THE RPG FOR WORST DAYS IS REASONABLE

6.7.1 The Role of Natural F i re in Nevada



### 6.8 REFERENCES

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-16.1 INTRODUCTION

The Regional Haze Rule (RHR) requires s t ates to estab lish reasonable progress goals for each Class I area within th e state (expres s e d in de civiews) that provide for reasonable progress towards achieving natural visi bility conditions by 2064. 40 CFR 51.308(d)(1) USEPA also released guidance, Guidance for Setting Reasonable Progres s Goals Under the Regional Haze Program, on June 7, 2007 for setting reasonable progre ss goals. The reasonable progress goals must provide for im provem ent in visibility for the m o st-im p a i red (20 percent worst) days over the period of the SIP and ensure no degradation in visibility f o r

the le ast-impaired (20 p e rcen t best) days over the sam e tim e. The planni ng period for the initial regional haze SIP is 2004 through 201 8, with an in terim review due five ye ars after sub m ittal of th e initial implem entation plan.

Chapter Two identifies the uniform r a te of progr e ss (URP) for Nevada’s o n ly Class I a r ea, th e Jarbidge W ilderness Area (Jarbi dge WA). Neva da com p ared base line visibility conditions to natural visibility conditions to determ ine the unifor m rate of visibility im provem e nt (in deciviews) that would n eed to be m a intained during each implem entati on period in order to attain natural visibility conditions by 2064, as shown on Table 2-1 and Figure 2-5.

Visibility m odeling was used to determ ine th e expected 2018 visibility im provem e nts for the Jarbidge W A resulting from existing federal a nd state regulations, including presum ptive sulfur dioxide (SO 2 ) Best Available Retrofit Technology (B ART) lim its for coal-fired electric generating units (EGU) with capac ity greater than 750 M W . Visibi lity m odeling indicates that im plem entation of existing rules cou p led with in stallation of BART controls, as captured by the projected P R P18a e m issions inventory, provides for an im provem e nt in visibility better than the URP for the Jarbidge W A on the m o st-im p aired da ys over the period of the SIP and identifies no degradation in visibility for the least- im paired days over the sam e period.

The m odele d 2018 extinction of 11.05 dv represents Nevada’s reasonable progress goal (RPG). Nevada’s long-term strategy to achieve this RP G is detailed in Chapter Seven. Given the significant em issions reductions anticipated from Nevada’s BART requirem e nts and the im ple m entation of other Clean Air Act (C AA) program s during this planning period, im ple m entation of these program s represents r easonable progress in Nevada for the initial regional haze planning period. The resulting m o de led visibility improvem e nt is identified as Nevada’s 2018 RPG.

The BART analyses con ducted by Nevada were based, in part, on an assessm ent of many of the

sam e factors addressed in estab lishing the RPG. The control requirem e nts im posed by Nevada’s BART determ inations also satisf y the RPG-rela ted requirements for source review in the first planning period. Theref ore, Neva da will not requ ire add i tional em issions contro ls bey ond BART for these sources during the first planning period.

Nevada concludes, based on its assessm ent of the sta t e’s s i g n if icant em issions r e duc tions in this first plannin g period, that it achiev e s reasonab l e p r ogress toward the natio n a l vis i bility goal for this planning period. Furtherm ore, Nevada de em s it is unreasonable at this tim e to request additional em ission controls on Nevada sour ces beyond those discussed below due to the

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-2negativ e “... im plication of comp liance costs to th e health an d vitality of industries w ithin ... ” Nevada (USEPA June 2007, p.5-1). It is reason able for Nevada to defer addition a l red u ctions to later planning periods in order to m a intain a consistent glidepath toward the long-term goal. Our

assessm ent is consistent with guidance provi ded in sections 1.2, 4.1, and 5.0 of USEPA’s Guidance for Setting Reasonable Progress Goals under the Regional Haze Program.

6.2 STEPS FOR DE VEL O PING REASONAB L E PROGRESS GOAL S

The steps in USEPA’s guidance for de veloping a RPG are listed below.

1. Establish Baselin e and Natural Visib i lity Conditio ns. 2. Determ ine the Glidepa t h (or Unif or m Rate of Progress). 3. Identify and Analyze the Measures Aim e d at Achieving the U n iform Rate of Progress:

a. Identify the key pollutants and sources and/ or source categories that are contributing to visib i lity impairm ent at each Class I area. b. Identify the contro l m e asures and as sociated em ission reductions th at are expected to result f r om com p liance with exis tin g rule s and other av ailable m easures for the sources and source categories that co ntribu te s i gn if icantl y to visibility im pairm e nt.

c. Determ ine what additio n al control m eas ures would be reasonable based on the statutory factors and other relevant factors for sources and/or source categories you have identified. d. Estim ate the im prove m e nt in visibility that would result from im ple m entation of the control m e a s ures you have found to be reas onable and com p a r e this to the uniform rate of progress. 4. Establish a RPG.

The following sections describ e ho w Nevada’s regional haze SIP addres ses each of the steps listed above and docum e n ts the techn i cal b a sis of each com p onent of the RPG. The discussion of Step3c, listed above, is deferred to Chapter Seven, which details Nevada’s long-term strategy.

6.3 ESTABLIS H ING BASELINE AND NAT URAL VISI BILITY CONDITIONS

Chapter Two, sections 2.2 and 2.3, of this SIP discusses the m e thodologies em ployed to identify the base line and natur a l visibility conditions for the Jarbidge WA . These data were used to determ ine th e rate of progress need ed to attain n a tural vis i bility cond ition s by the year 2064.

6.4 DET E RMI N ING THE UNIFORM RATE O F PROGRESS

Chapter Two, section 2.4, of this SI P identif ie s the URP needed to attain natura l vis i bility conditions for the Jarbid ge W A . Ne vada com p a r ed the b a seline vis i bility conditions to natural visibility co nditions to identif y the u n if orm rate of visibility improve m e nt that would need to be

m a intained during each imple m entation period in or der to atta in natu ral visibility conditions by 2064.

The URP or glidepath is shown on Figure 6-1, reproduced from Chapter Two. The baseline conditions for the 20 percent worst days are shown by the upper short line on Figure 6-1, while

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-3natural visibility conditions fo r the worst days are shown by th e long horizontal line. The baseline visibility conditions for the 20 percent be st days are shown by the short lower line. The diam onds represent the annual average visib i lity c onditions for each of th e baseline y ears for th e worst and best days. The URP or glidepath is shown by the sloping line interrupted by open triangles identifying the URP in five-year increm ents. The 2018 URP for the Jarbidge W A is 11.09 deciviews.

FIGURE 6-1

UNIFORM RATE OF P R OGRESS GLIDEPAT H

U n i f or m R a t e o f R eas o n a b l e P r o g r es s G l i d ep at h Jar b i d g e Wi l d er n ess A r e a - 20% B e st an d Wo r s t D a y s

12 .0 7 11 .7 9 11. 44 11 .0 9 10 .7 4 10 .3 9 10 .0 4 9. 69 9. 34 8. 99 8. 64 8. 29 7. 87

0 2 4 6 8 10 12 14 16

200 0 2 0 0 4 2 0 0 8 2 0 1 2 2 016 2 020 202 4 202 8 2 0 3 2 2 0 3 6 2 0 4 0 2 044 2048 205 2 205 6 206 0 2 0 6 4

Ye a rHazeIndex(Deciview)

B a se lin e Ob s 2 0 % W 2 000

- 200 4 B a s e l i n e 2 0 % W Gl i d e Pa th B a se lin e Ob s 2 0 % B 2 000

- 200 4 B a s e l i n e 2 0 % B Na t u r a l Co n d it i o n s S i 7 S i 8 20 18 - En d o f 1s t Pl a nni ng P e r i o d

6.5 IDENTIF Y ING THE MEASURES TO ACHIEVE THE UNIFORM RAT E OF PROGRESS

40 CFR 51.308(d)(1)(i)(B) requires states to cons ider the unif o rm rate of progress and the

em ission red u ctions n eed ed to ach iev e it for th e period covered by the plan. The next step in setting the R P G is identifying and analyzi ng the measures aim e d at ach ieving the URP, including: identifying the key vi sibility-im p airing pollutants and their sources; identifying the existing con t rol m easures and the as s o ciated redu ctions ; iden tifying reaso n able add itional control

m easures; a nd estim atin g the resu lting visibility improve m e nt, as discussed in the following sections.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-46.5.1 Key Pollu ta nts and Sources of Imp a irment

The analyses of the Interagency Monitoring of Protected Visual Environm ents (IMPROVE) monitor data, as presented in Chapter Two, s ection 2.5, identify orga nic m a tter carbon (OMC) and coarse m a tter (CM) as the two most signi ficant components of annual average visibility im pairm e nt at the Jarb id ge W ilderne ss Area for the worst days of the baseline period. For the worst days, OMC and CM account for more than sixty percent of the average annual reconstructed extinction at JARB1. For these d a y s , SO 4 and NO 3 account for less than a quarter of the extinction, as shown on Table 6-1, m odifi ed from Table 2-2.

TABLE 6-1

MONITOR E D CONTR I BUTIONS TO AVERAGE ANNUAL RECONST R UCT E D E X TINCTION FOR BAS ELINE PERIOD

OMC Extinction CM Extinction SO 4 Extinction Soil Extinction EC Extinction NO 3 Extinction Sea Salt Extinction

20% Worst Days Aver a g e 40 .0% 22 .3% 16 .7% 9

. 7 % 6

. 5 % 4

. 5 % 0

. 3 %

20% Best Days Aver a g e 26 .3% 9

. 2 % 40 .9% 2

. 8 % 9

. 4 % 9

. 8 % 1

. 6 %

Com p ilation and analyses of baseline (2002) a nd 2018 em issions inventories, presented in Chapter Three, dem onstrate th at nearly three quart ers of Nevada’s total em issions originate from natural (i.e., non-anthropogenic) sources , see Table 3-2. Sulf ur oxides (SO x ), nitrogen oxides (NO x ), and ammonia (NH 3 ) are the only pollutants whose 2018 em issions are dom inated by anthropogenic sources, although both particulate m a tter fine (PMF) and particulate m a tter coarse (PMC) 2018 em issions are sub-equally divided between natural and an thropogenic sources. Note that th e exis ting 20 18 em ission inventories do not includ e reductions resulting from the insta lla tion of BART, except f o r SO x presum ptive lim its f o r s ubject-to

- BART EGU’s with capacity greater than 750 M W

. Analyses of the projected 2018 em is sions data have led to the following conclusions.

• The m a jority of the em i ssions that form the m o nitor e d spec ie s OMC, volatile organic

com pounds (VOC) and prim ary organic aeroso l (POA) e m issions, are from biogenic (88 percent) and natural fire (91 percent) sources, respectively.

• Em issions o f PMC are predom inantly f r om windblown dust ( 50 percen t) and f ugitive dust (36 percent) sources.

• Point sources account for the m a jority (61 percent) of em issions of SO x , a component of monitored s p ecies SO 4
.

• Em issions o f PMF are predom inantly windblown dust (43 p e rcen t) and f ugitiv e dust (30
percen t) sou r ces.

• Em issions of elem ental carbon (EC) are dom inated by natural fire (83 percent).

• Point sources account for the m a jority (50 percent) of NO x em issions, a com ponent of monitored s p ecies NO 3 ; although m obile sources are al so a significant (27 percent) contributor.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-5Visibility m odeling projections, shown in Figur e 6-2, indicate the rela tive contribution to 2018 visibility im pairm e nt at the Jarbidg e WA for each visibility impairing sp ecies in units of inverse

me g a me t e r s ( M m -1 ). This graph sho w s an extinction reductio n for each s p ecies by th e end of the first planning period, except Sea Salt and CM. CM e m issions were held constant from the baseline to 2018 and Sea Salt is not an importan ce com ponent of extinction at JARB1. As noted above, VOC and POA, a nd CM e m issions leading to OMC (shown by the green line on Figure 6- 2) and CM (shown by gray line) extinction resp ectively, are dom i nated by natural sources.

FIGURE 6-2

CMAQ MODEL PROJ ECTED EXTINCTION BY SPECIES FOR J A RB1 2018 WORST DAYS

The SO 4 and NO 3 source apportionment m odeling identifi es the relative concentration due to SO x and NO x em issions by source area and source categ ory, as shown in Figures 6-3 and 6-4, respectively. Figure 6-3 shows the dom i nating ef fect of uncontrollable em issions from outside the m odeling dom a in (right side of the x axis) on SO 4 concentrations at the Jarbidge WA. Outside Dom a in contributions are four tim es greater than any other source category. SO x em issions from the Pacific Offshore source cate gory (PO on x axis of graph) are also a significant cont ribu tor to SO 4 concentrations at JARB1. Em i ssions from three other states, Idaho, Oregon, and W a shington, have larger contributions to the SO 4 concentration than does Nevada for both 2002 and 2018.

Figure 6-4 shows the largest contributor to NO 3 concentrations at the Jarbidge WA is NO x em issions from Idaho, closely follow e d by the uncontrollable em issions from outside the modeling dom a in. Idaho’s NO x contribution to baseline NO 3 form ation is largely due to m obile and area sources, with a large in crease in the importance of area source em issions for 2018. Em issions from Utah have a larger contribution to NO 3 concentration than does Nevada for 2002, but slightly less than Nevada for 2018 due to m obile source em issions reductions. Note the significant reduction in 2018 co ncentrations due to reductions in m obile source em issions from all states.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-6FIGURE 6-3

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

FIGURE 6-4

NITRATE P S AT SOUR CE RE GION BAR CHART FOR WORST DAYS 2002 AND 2018

6.5.2 Emissions Reductions due to Existi ng Air Pollution Control Measures

The RHR re quires states to subm it a long-term strategy that includes such m easures as are necessary to achieve the RPG for each Class I ar ea. RPGs are interim goals that repres ent increm ental im prove m e nt over tim e toward the goal of natural background conditions. Prior to developing a long-term strategy, ex isting control m easures must be assessed. As stated in USEPA gui dance (June 2007): “One im portant factor to keep in m i nd wh en establishing a RPG is that you cannot adopt a RPG that represents le ss visibility improvem e nt than is expected to result from the implem entation of other CAA requi rem e nts. You must therefore determ ine the am ount of e m issions reductions that can be expected from identified sources or

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-7source categ o ries as a result of requ irem ents at the local, State, and federal lev e ls during the planning period of the SIP and th e resulting improvem e nts in visibility at Class I areas. Given the signi f i can t e m issions reductions that we antic ipate to resu lt from BART, the CAIR, and the im plem entation of other CAA program s, including ozone and PM 2. 5 NAAQS, f o r m a ny States this w ill b e an im portan t f i rst step in determ ining your RPG, and it may be all that is nece ssary to achieve reasonable progress in the first planni ng period for some States.” (p. 4-1) emphasis added

There are significant control program s being i m pl em ented between the baseline period and 2018, on the federal, state and local levels. Em issi ons reductions from“on-the-way” and “on-thebooks” control programs and the implem entation of BART, as cap tured in the PRP18a em ission inventory, are projected to achie ve substantial visibility impr ovem e nt by 2018 at the Jarbidge WA and other Class I areas in the west. In fact , the Jarbidge WA repres ents the on ly western Class I area where the R P G m eets or exceeds th e URP for 2018. In general, these pro g ram s consist of regulations affecting m obile source em i ssions and, to a lesser degree, stationary sources. The following sections describe em issions control progr am s considered in developing the 2018 emissions inventory PRP18a based on control m e a s ures that are expected to result from

com p liance with exis tin g rules and other av ailable m easures.

6.5.2.1 Federal Rules

Em issions reductions due to the following federa l pollution control program s were incorporated into the PRP18a em issions inventory. These program s affect m obile, point and area source

em issions.

Heavy Duty Diesel (2007) Engine Sta ndard (On-road trucks and buses) The USEPA set a PM em issions standard for new heavy-duty engines of 0.01 gram s per brakehorsepower-hour (g/bhp-hr), to take f u ll effect fo r diesel engines in the 2007 m odel year. This rule also included standards for NO x and non-m e thane hydrocarbons (NMHC) of 0.20 g/bhp-hr and 0.14 g/bhp-hr, respectively. These NO x and NMHC standards will be phased in together between 2007 and 2010 for diesel engines. Sulfur in diesel fuel m u st be lowered to enable modern pollution control technology to be effective on these trucks and buses. Pursuant to USEPA rule, a 97 percent reduction in the sulfur content of highway dies el fuel from 500 ppm (low sulfur diesel) to 15 ppm (ultra-low sulfur diesel) b ecam e effective in Nevada in October 2006.

Tier 2 Tailp ipe (On-roa d vehicles ) The USEPA m obile source rules include the Tier 2 fleet averaging program, m odeled after the California L o w Em ission Vehicle II standards. Manufacturers can pr oduce vehicles with

em issions ranging from r e latively dirty to zero em issions, but the m i x of ve hicles a m a nufacturer sells each year m u st have average NO x em issions below a specified value. Tier 2 standards becam e effective in the 2005 m odel year.

Large Spark Ignition a nd Recreational Vehicle Rule The USEPA has adopted new standards for em issions of NO x , hydrocarbons and carbon monoxide from several groups of previously unregul ated non-road engines. Included in these are

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-8large industrial sp ark-ign ition engines and recr eational veh i cles. Non-road spark-ignition engines are those powered by gasoline, liquid pr opane gas or comp ressed natural gas rated over 19 kilowatts (25 horsepower). These engines are used in com m e rcial and industrial applications, included forklifts, electric generators, airport bagg age transport vehicles, and a variety of far m and construction applications. Non-road recreati onal vehicles include snowm obiles, off-highway motorcycles and all-terrain-veh ic les. These rules were initia lly effective in 2004 and will be fully phased in by 2012.

Non-road Diesel Rule This rule sets standards that will reduce em issi ons by m o re than 90 percent from non-road diesel equipm ent and reduce sulfur levels by 99 percent from current levels in non-road diesel fuel starting in 2 007. This step will app l y to m o st non -road diesel fuel in 201 0 and to fuel used in locom o tives and m a rine vessels in 2012.

Industrial Boiler/Process Heater MACTs The USEPA issued f i na l rules to subs tantially reduce em issions of toxic air pollutants from industrial, comm ercial, and inst itutional boilers and process h eaters. These rules reduce

em issions of a num ber of toxic air pollutants , including hydrogen chloride, m a nganese, lead, arsenic and m e rcury by 2009. This ru le also reduces em issions of SO 2 and PM in conjunction with the toxic air pollu tant reductions. The applied Maxim u m Achievable Control Technology (MACT) control efficiencies were 4 percen t for SO 2 and 40 percent for PM 10 and P M 2. 5 . The USEPA’s industrial boiler MACT rules were va cated on June 8, 2007. WRAP states decided to leave these controls in th e m odeling since it is b e lieved th at b y 2018 the USEPA will have reprom ulgated a boiler MACT rule or states will have addressed the issue through rulem a king.

Combustion Turbine and Reciprocating Internal Combustion Engines MACT The projection inventories do not include the NO x co-benefit of the MACT regulations for Gas Turbines or Station a ry R ecipro cating Intern al Combustion Engines, which the USEPA estim ates to be sm all com p ared to the overall inventory.

VOC 2-, 4-, 7- and 10-year MACT Standards Various point source MACTs and associated em ission reductions were imple m ented. Reductions occurring before 2002 were assum e d to be accou n ted for in the 2002 base year inventory.

6.5.2.2 Consent Agreements

The following section d e scrib e s con s ent agr eements for the Mohave Generating Station (Mohave) and Reid Gardner Genera ting Station (Reid Gardner). M ohave is owned by Southern California E d ison (SCE) and is located in Laughl in, Nevada. Reid Gardner is owned by NV Energy (form e rly Nevada Power Com p any) and is lo cated near Moap a, Neva da. Both facilities are lo cated in Clark Country and perm itted throu gh NDEP.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-9Mohave Generating Station 1 On February 8, 2002, USEPA prom ul gated a final ru le revising Nevada’s federal im plem entation plan for protection of visibility in Class I ar eas (visibility F I P; 40 CF R 52.1488). That revision concerned em issions reduction requirem e nts fo r Mohave. The requirem e nts were based on a consent decree between the owners of Mohave and the Grand Canyon Trust, the Sierra Club and the National Parks and Conservation Associati on, addressing issues raised by the U.S. Departm e nt of the Interior (DOI) regarding Mohave ’s contribution to visibi lity im pairm e nt at the Grand Canyon National Park (GCNP) from SO 2 em issions. In addition, by incorporating the requirem e nts of the consent decree into the long-te rm strategy of the Nevada visibility FIP, USEPA argued that there would be allowan ce for reasonable progress toward the national visibility go al with respe c t to Mohave’s contribution to visibil ity im pairment at GCNP from SO 2
em issions according to the criteria set forth in Sec tion 169A(g)(1) of the C AA.

This rule was USEPA’s first re port assessing the long-term visibi lity strategy for Nevada since
prom ulgating the Nevada visibility F I P. USEP A reviewed the long-term strategy only for the purpose of addressing D O I’s certification of ex isting visibility impair m e nt at GCNP and Mohave’s contribution to that im pairm e nt, a nd evaluating whether the term s of the Mohave consent decree would m a ke reason able progress toward the nationa l visibility goal. The revision of the long term strategy of the Nevada visi bility FIP was to allow for reasonable progress toward the CAA national vis i bility goal with re spect to Mo have’s con t r i bution to visibility im pair m e nt at GCNP due to SO 2 em i ssions. USEPA did not conduct a comprehensive review of the long -te r m strategy o f the Nevada visibility FI P at tha t tim e. Accordin g to the Fed e ral Reg i ste r notice (67 F R 6130), federal land m a nagers did no t provide any inform ation for such a review and USEPA did not have any eviden c e that v i sib i lity im pairment at any other Class I area cou l d be attributed to a specific s ource or group of sources located in Nevada. USEPA reasoned that the reg i onal haze ru le would resu lt in a region al s t rategy for w e stern sta t es and would provide for additional p r ogress towa r d the nation al vis i bility goal. The Nationa l Park Service d i d r e view the consent decree and believed that a USEPA ru le making which adopts the em ission lim i t s and other requirem e nts from the decree was an a ppropriate m eans of a ddressing its concerns regarding the im pact of SO 2 e m issions from Mohave on visibility impairm e nt at GCNP.

The requirem e nts of the visibility FIP were includ ed as an ap plicab le req u irem ent in the schedule of

com p liance sec tion of Mohave’s T itle V operating perm it:

Interim Em i ssion Lim its - For the period of tim e between the entry of the decree (Decem ber 15, 1999) and the date on which each unit m u st commence com p liance with the final

em ission lim itations set forth in Section VI.A.2.b of the Operating Perm it, the follow i ng SO 2 and opacity em ission lim its shall apply: a. SO 2 em iss i ons shall no t exceed 1.0 lb/MMBtu o f heat input calcu lated o n a 90 boiler operating day rolling average bas i s for each un it.

1 On J u ne 1 0

, 2 0 0 9

, t h e o w ne r s o f t h e M o ha v e Ge nerat i n g S t at i on, i n cl u d i n g S o ut he rn C a l i f or ni a E d i s o n (SC E )

, an nou n c ed t h e d ecision to d e co mmissio n th e statio n an d rem o v e th e g e n e ratin g facility fro m th e site. Th e SCE n e ws release states t h at in 20 10 , the p l an t ’ s g e n e ratin g eq u i p m e n t will b e rem o v e d and its op eratin g p e rm its t e rm in ated ( ht t p : / / www .ed i son

. com / press r o o m / pr.asp ? b u=sce&y ear= 2 00 9&i d =7 2 3 4 ).

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-10b. The opacity of em issions shall b e no m o re than 30 percen t, as averaged over each separate 6-m i nute perio d within an hour, beginn ing each hou r on the hou r, m e asured at the stack, with no m o re than 375 exceedances of 30 percent allowed per calendar quarter (including any pro rated portion th ereof), regardless of reason.

The consent decree require d installation of low NO x burners with over-fire ai r and fabric filter dust collection devices, but no associat ed em ission lim itatio ns f o r eithe r NO x or PM/PM 10 ; however, opacity was lim ited to 20 percent. Th e consent decree required the controls to be installed and operational by January 1, 2006 or th e plant would need to cease operations. The plant has been in a period of tempor a r y shutdown since January 1, 2006.

However, Mohave has maintained their operating perm it during this period in anticipation of
resta r ting or selling the f acility, and SCE has subm itted a BART analysis, discussed in Chapter Five, as Mohave is subject to BART under the R H R as an EGU with capacity greater than 750 M W . As such, the PRP18a em ission invent ory incorporated the presum ptive BART SO 2 lim it. The PRP18a inventory has projected SO 2 and NO x em issions from Mohave of 8,701 tpy and 19,595 tpy, respectively. Mohave emissions repr esent 19 percent of projected 2018 (18PRPa) statewide S O 2 em issions and 14 percent of projected statewide NO x e m issions.

However, SCE’s BART analysis proposes fuel switching from coal to natural gas. F u el switching w ill resu lt in s i gnif i can t e m issions reductions of SO 2 and NO x with a greater than 95 percent reduction in SO 2 em issions from the PRP18a projecti ons and a 75 percent reduction in NO x e m issions from the PRP18a projections. The BART e m issions limits required by this SIP will be incorporated in f u ture W e ster n Regional Air Partne rs hip (W RAP) visibility modeling and

are an tic ipated to redu ce visibility im pairm e nt at Class I areas . SCE’s BART analysis is discussed in Chapter Five, where a link is provided to the complete analysis.

Reid Gardner Genera ting Station The recen t action at Reid Gardner was not related to any visib ility im pairm e nt certification. Rather, the order issued by NDEP and the consen t decree issued by USEPA in cooperation with NDEP and Reid Gardner were rela ted to com p liance issues at th e station, specifically, record keeping and opacity exceedances. Nevertheless, som e of the reduc tions ordered at Reid Gardner

m a y result in visibility improvem e nt s.

In a letter and order, date d April 3, 2007, NDEP r e quired Nevada Power Com p any (now NV Energy) to install natural gas ig niters on units 1 thr ough 4 at Reid Gardner no later than July 1, 2009, and install baghouses on units 1 through 3 Reid Gardner no late r than July 1, 2010. These requirem e nts were also f ound in the Reid Gardne r consent decree entered into by Nevada Power Com p any, NDEP and the USEPA on April 3, 2007 a nd approved by the Unite d States District Court on June 14, 2007. The consent decree further imposed SO 2 lim itations beginning on the effective date of the decree: Measured se parately, units 1, 2 and 3 shall not have SO 2 em issions in excess of 0.40 lb/MM B tu, based o n a 10-day rolling average period.

Installation of the m a ndated em issio n s contro ls will have th e effect of reducing pro j ected 2018 (18PRPa) SO 2 em issions by 11 percent or 219 tpy and NO x em issions by 17 percent or 1822 tpy from the Plan02d inventory. Reid Gardner is al so subject to BART unde r the RHR. Proposed

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-11BART controls for Reid Gardner will re sult in a 60 percent reduction in NO x em issions from those projected in the P R P18a e m issions inventory but a 30 percent increase in SO 2 em issions from the PRP18a inventory, resulting in an overall reduction of nearly 5,000 tpy of NO x /SO x com b ined. The BART analysis is discussed in Chapter Five where a link is provided to NV Energy’s B A RT report. The BART em issions lim its require d by this SI P will be in c o rporated in future WRAP visibility modeling an d are an ticip ated to redu ce vis i bility im pair m e nt at Class I

areas.

6.5.2.3 Other Air Pollution Control Measures

Additional air pollution control m e a s ures were incorporated in the PRP18a em issions inventory to account for em issions reductions due to all on-the-way or on-the-book s control program s

. Som e of these program s are specific to Nevada, while others have broader application in the WRAP states. These program s are identified below:

• Em issions reductions resulting from sm oke m a nagem e nt program s were accounted f o r by applying em issions reduction techniques to the 2000 to 2004 average fire em issions.

• Em issions reductions resulting from state oil and gas em issions control program s for Rocky Mountain S t ates.

• Em issions reductions resulting from the inst allation of known BART for facilities in Colorado, Utah, North D a kota and one facility in Oregon.

• Application of presumptive SO 2 BART lim its f o r EGU’s with capacity gre a ter than 75 0 MW across the WRAP region.

• Em issions reductions resulting from ozone and PM 10 SIPs in place acro ss the W R AP region. Nevada’s ozone and PM 10 SIPs are discussed below.

In 2000, Nevada had several nonattainm e nt area SI Ps in place. These S I Ps are effective in Washoe and Clark Counties, the locations of Reno and Las Vegas, respectively. In NDEP’s jurisdiction, the only non attainm e nt area was the Central S t eptoe Valley, which was out of
atta inm e nt for SO 2 because of e m issions from a copper sm elter. This area was designated attainm e nt in 2002. Table 6-2 shows the designati on status for Nevada’s nonattainm e nt areas.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-12TABLE 6-2

NONATTAINMENT AREA REDESIGNATION STATUS AS OF SEPTEM BER 2008

Planning Area Nonattainment Date Redesignations
Carbon Monoxide
Lake Tahoe Basin (HA90) 3/3/78 USEPA approved 12/15/03; effective 2/1 3 /04 Las Vegas Valley (HA212) 3/3/78 a nd 1 1 /15/90 Request sub m itted 9/18/08 Truckee Meadows (Reno) (HA87) 3/3/78 and 11/15/90 USEPA approved 7/3/08
Oz one

Washoe County 1/6/92 (1 hr) 1/16/01 (1 hr) 6/15/05 1 hr NAAQS revoked; Maintenance plan approved

1/18/08; effective 3/18/08 Clark County 9/13/2004 (8 hr) PM 10 Las Vegas Valley (HA212) 11/15/90 Pahrum p Valley 2 (HA162) does not apply MOU Sept 2003 Truckee Meadows (Reno) (HA87) 11/15/90 SO 2
Central S t eptoe Valley (HA179M) 3/3/78 USEPA approved 4/12/02; effective 6/1 1 /02

Clark County Clark County has PM 10 and carbon monoxide (C O) SIPs. For m a ny years, the Las V e gas Valley

severe ly vio l ated air qu a lity s t anda rd s f o r PM 10 a i rborne p a r t iculate m a tter. Fugitiv e dust contributed substantially to this pr oblem , but there were thousands of PM 10 sources spanning an area of over 300,000 acres. In an un preceden ted strategy, Clark County adopted fugitive dust rules m o re stringent than any prior program in the country and employed a team of 28 field

com p liance officers dedicated to enforce fugiti ve dust regulations. To m a ke its approach effective, the program target ed large construction sites a nd conducted an extensive public outreach campaign to educate owners of large expanses of vacant residential land. T h e departm e nt also funded new research in PM 10 paved-road an d vacant-lan d em issions, which provides new techniques with greater accu racy for estim a ting em issions. Clark County’s advanced dust control program serves as a nation al m odel and has been integral in leading the Las Vegas Valley to achieve PM 10 concentrations below the USEP A’s standard. In the June 2007 Milestone Achievem ent Report, Clark Count y dem onstrated achievem e nt of the 24-hour PM 10 National Am bient Air Quality Standards (NAAQS) and continue d attainm e nt of the annual PM 10 standard. CO control strategies include cl eaner burning gasoline, tr ansporta tion contro l

m easures, the state Alternative Fueled Vehicle pr ogram and woodstove and fi replace regulations.

2 Pahrum p Valley is not a designate d nonattainm e nt area. A Me m o randum of Understa ndi ng is in place, whic h defe rs a nonattainm e nt designation, t o accele r ate attainm e nt of the PM 10 n a tio n a l am b i en t air qu ality stand a rd s.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-13Washoe County Washoe County or the Truckee Meadows Hydrographic Area (HA 87) has SIPs for ozone, CO and PM 10 . Control m easures focus on off-road and on-road vehicles, oxyge nated fuel, gasoline vapor recovery, transportation control m easur es, residential wood burning and dust control

m easures such as the s t reet sweep in g program

.

This sec tion summarized the sign if ic ant f e dera l, state, and lo cal con t rol p r ogram s that are being im ple m ented between the baseline period and 20 18. These control program focus prim arily on mobile (both on- and off-road) em issions sour ces and to a lesser degr ee area and stationary

source em issions. Em issions projections based on im ple m entation of all the described program s have been incorporated into the prelim inary r easonable progress em issions inventory (PRP18a). The em ission invento r y will be updated in late 2 008 or 2009 to inco rporate BART e m issions estim ates for further visibility m odeling.

6.5.3 Resulting I m provemen t in Visibilit y

Utilizing W R AP Regional Mode ling Center m o deling results, Nevada has estim ated th e expected visibility improvem e nts by 2018 at the Jarbidg e WA resultin g from the implem entation of existing federal and state regulations discussed above. Figure 6-5 shows the URP glide slope with a m ode led 2018 visibility projection of 11.0 5 dv, although the value in Figure 6-5 has been rounded to o n e decim a l place.

6.6 ESTABLIS H ING REASONABL E PROGRES S FOR NE VADA

WRAP baseline m odeling dem onstrates that the 2018 prelim i n ary reasona ble progress scenario (PRP18a) provides for an improve ment in visibility better than the uniform rate of progress at the Jarbidge W A for the most im paired days over th e period of the im plem e n tation plan, and ensures no degradation in visibility for the least impaired days over the sam e period (see Figure 6-5 and Table 6-3). The im provem ent is the result of the em issions reduc tions from existing and planned

em issions controls due to federal and state program s (i.e., on-the-way and on-the-books), as discussed in Chapter Three.

For the 20 percent worst days, the reasonable pr o g ress goa l for Jarb idge provides for greater visibility improvem e nt by 2018 than the area’s uniform rate of pr ogress, as shown on Table 6-3. For the 20 percent best days, the reasonable prog ress goal for Jarbidge indicates an im provem e nt of visibility by 2018 greater than current best day conditions. Th ese projections are based on the modeling results discussed in Chapter Four.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-14FIGURE 6-5

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

Identification of the 2018 reasonable progress go al for Jarbidge is a required elem ent of Nevada’s regional haze SIP. Nevada’s reasonabl e progress goal for the Jarbidge W A is 11.05 dv for the 2018 worst days and 2.50 dv for the 2018 best days, as shown in Table 6-3.

TABLE 6-3

SUMMARY OF MODEL PRE D ICTED PROGRESS TOWARD 2018 UNIFORM RATE OF PROGRESS AT JARB1

20% Worst Days 20% Best Days

M a ndat o ry

Class I Fede ral

Area Wo rst Day s Baselin e (Deci view) 2 018 U R P (Deci view) RPG 20 18 M odel i n g

Resu lts (Deci view) CM AQ M odel i n g

Perce n t Toward

2 018 URP Best Days Baselin e (Deci view) 2 018 M odel i n g

Resu lts (Deci view) CM AQ 2 018 M odel i n g

Resu lt Less T h an Baselin e?

Jarbi dge Wi l d e r n e s s Area 12 .0 7 1 1 .0 9 1 1 .0 5 10 4. 1 % 2. 5 6 2. 5 0 Y e s

The background and results of the m onitoring, emi ssions and modeling analys es are discussed in Chapters T w o, Three, and Four of this SIP and provide the technical basis for the establishm ent of Nevada’s reasonable progress. Nevada has ut ilized th e tech nical analys es develop e d by the W R AP to comply with USEPA’s guidance for developing its RPG.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-156.7 DEMONST RATION T H AT THE RPG FO R WORST DAYS IS RE ASONAB L E

USEPA gui dance (June 2007) indicates, “. . . St ates m a y establish a RPG that provides for greater, lesser, or equivalent visi bility im prove ment as that desc ribed by the glidepath,” (p. 1-3) and goes on to state, “It is reasonable for you to defer reductions to later planning periods in order to m a intain a consistent glidepath toward the long-term goal.” (p. 1-4) It further states: “After determ ining the amount of e m issions reductions of vi sibility im pairing pollutants that m a y be expected from im ple m entation of other CAA program s, you will be read y to identify any additional measures that are reasonable (emphasis added)

. The RHR gives States wide latitude to de term ine a dditional control requirem e nts, and there are m a ny wa ys to approach identifying additional reasonable

m easures; however, you m u st, at a m i ni m u m, c onsider the four st atutory factors. Based on the contribution from certain sour ce categories and the m a gnitude of their

em issions you may determine that li ttle additional analysis is required to determine further controls are not wa rranted for this ca teg o ry .”(p. 4-2) emphasis added

The 2018 RPG identified in Table 6-3 for the 20 percent worst days show an im provem e nt in visibility better than the 2018 URP. For this reason, in conjunction wi th other evidence and docum entation described below and the fact that Nevada is meeting its share of em issions reductions at Class I area s outside of the state (see secti on 7.9.3.2), Nevada m a intains its RPGs are reasonable. The following factors support this conclusion:

1. The 2018 RPG shows better prog ress than the 2018 URP. As shown in Table 6-3, Nevada’s 2018 RPG shows better visibility im provem ent that the 2018 URP for the worst days and ensures no visibility degradation for the least im paired days of 2018. Therefore, it is reasonable to defer additi onal em issions reductions to la ter planning periods in order
to m a intain a consis tent glidepa t h to ward the lon g -term goal.

2. Reductions in anthropogenic em issions consistent with 2018 URP are reasonable. Meeting the 2018 URP a t the Jarbidge W A re quires an 8.1 percent reduction in the haze index expressed in deciviews. The PRP 18a e m ission inventory shows a 33 percent reduction of SO x e m issions and a 17 percent reduction of NO x em issions when com p ared to the Plan0 2d invento r y

. W h en the insta lla tion of BART controls on Nevada sources is taken into account, the reductions increase to 44 percent for SO x and nearly 33 percent for NO x from the Plan02d inventory. The W E P em issions projections show a 14.5 percent reduction for NO x , but a 16.8 percent increase in SO x by 2018. The SO x increase is due partly to the siting of a proposed coal -fired EGU in eastern Nevada, as well as the significant S O x em issions reductions from m obile and point sources in Idaho, which incre a se th e rela tive contribut ion of Nevada em i ssions. This com b ination of e m issions reductions from anthropo genic sources consis tent with the req u ired reduction in haze index supports the dem o nstra tion of reasonable progress.

3. Reductions in anthropogenic em issions are cons istent with Nevada’s share of e m issions reductions to m eet RPGs of Cl ass I areas in other states. Analyses of the relationships between Nevada’s SO x and NO x e m issions, source apportionm ent m odeling, and visibility im pairm e nt at Class I areas in adjacent states ind i cate s Nevada’s em issions reductions b y 2018 represent Nevada’s share of the em issions reductions necessary for

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-16these Class I areas to ach ieve reasonable progress. The analys es are p r esented in s e ction 7.9.3.2 of Chapter Seven.

4. Major reductions in m obile source em issions. Mobile sources, both on- and off-road, are signif i can t e m itters of NO x and to a lesser degree SO x . These source categories show a considerable reduction in em issions by 2018, a 63 percent reduction in SO x and 49 percent reduction in NO x from 2002 levels. Although thes e reductions are prim arily due to “on-the-books” federal regu lations, the em issions reductions are consistent with and support Nevada’s dem onstration of reasonable progress.

5. Offshore m a rine shipping and international em i ssions contribute signific antly to vis i bility im pair m e nt. Source apportionm ent modeling (secti on 4.3 of Chapter Four) identifies the significant contribution of international and off-shore m a rine em issions (e.g., source categories O u tside Dom a in, Canada, Mexic o, and Pacific Offs hore) to visibility im pair m e nt at the Jarbidge W A . These s our ce cat e gori e s ar e ma jor contributors to S O 4 and NO 3 extinction as shown by the source apport ionm ent m o deling results with outside dom a in, Mexican, and C a nadian em issi ons representing 51 percent of the SO 4 visibility im pact and 30 percent of the NO 3 i m pact at JARB1. Control of international and offshore sources will likely account fo r greater im provem e nt in the SO 4 and NO 3 extinction contribution at the Jarbidge W A . Al though USEPA has recently addressed off-shore

em issions by the Marine Diesel Engine Rule (see section 7.9.2.3 of Chapter Seven), no United States regulatory body has authority to control international em issions.

6. Natural sou r ces contribu te sign if ican tly to v i sib i lity im pairm e nt. Nevada’s analyses of the m onitoring, em issions and m odeling data (Chapters Two, Three, and F our) strongly support the finding that the contribution of na tural and uncontrollable em issions sources, such as natural fire and windblown dust, and the pollutants associated with these sources (OMC, EC, PMC and PMF), contr i b u te sign if ica n tly to v i sib i lity im pairment. The 20 18

em ission inventory show s increased em issions of these pollutants, excep t EC, while th e

em issions of SO x and NO x decreas e significan tly . The role of natural fire is discussed below.

7. Consideration of the costs of com p liance, tim e necessary for com p liance, the energy an d non-air quality environm ental im pa cts of co m p l i ance, and rem a ining useful life of existing sou r ces th at con t ribu te to v i s i bility im pairm e nt . In light of the 6 factors listed above, it is Nevada’s po sition that th e cost s of an y additional contro l m e a s ures beyon d those docum ented in this chapte r and Chapte r Seven are unreasonable at this tim e and would im pose unnecessary burdens on the health and vitality of industries within ou r state. Since the cos t s of com p liance are unr easonable, no further analysis of these four factors was conducted.

6.7.1 The Role of Natural Fire in Nevada

The role of natural fire contribu tions to visibility impairm ent at the Jarbidge W A is undeniable as shown in Figure 6-6, wh ich disp lays tim e lines for each v i sib i lity im pairin g species fro m 1988 to 2006 for all IMPROVE sam p le days. As noted prev iously, annual visibility impairment due to OMC e m issions from natural fires are highly variable from yea rto year. Som e of the monitored visibility impairm e nt is due to local natural fires, but regional transport of sm oke is common, as

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-172002 dem o nstrates when large tim ber fires in Arizona, Colorado and Oregon contributed to elevated OMC extinction at the Jarbidge WA.

The natural fire data presented in Table 6-4 sh ow significant burned acreage in proxim ity to the Jarbidge W A for 1999, 2006 and 2007. These data were downloaded from the National Interagency Fire Center ( http://www.nifc.gov/fire _info/fire_stats.htm ) list of 1997-2007 fires greater than 100,000 acres and year-t o-date fires for 2008. Only data for fires in northeastern Nevada and southern Idaho within approxim a tely 100 m iles of the Jarbi dge W A were com p iled. Com p arison of Figure 6-6 and Table 6-4 dem onstrates the correlation of large fires and visibility im pair m e nt at the Jarbidge W A for 1999 and 2006. No fires in excess of 100,000 acres were recorded in Nevada from 2000 to 2005.

FIGURE 6-6

SPECIES TI ME SERIES EXTINCTI ON FOR PERIOD OF RECORD AT THE J A RBIDGE WILDERNE S S ARE A

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-18TABLE 6-4

LARGE NATURAL FIRES NE AR THE JARBIDGE W I LD ERNESS AREA 1999 - 2008

Year Fire Nam e State Acreage
1999 Dun Glen Com p lex Nevada 288,220 1999 Sadler Complex Nevada 224,509
1 9 9 9 B a t t l e Moun tain Com p l e x N e v a d a 1 6 9

, 6 0 8
1 9 9 9 J u n g o Com p l e x N e v a d a 1 6 9

, 2 2 0 1999 Acreage 851,557
2 0 0 6 W i n t e r s N e v a d a 2 3 8

, 4 5 8
2 0 0 6 C h a r l e s t o n Com p l e x N e v a d a 1 9 0

, 4 2 1
2 0 0 6 S h e e p N e v a d a 1 5 0

, 2 7 0 2006 Acreage 579,149
2 0 0 7 M u r p h y C o m p l e x I d a h o 6 5 2

, 0 1 6 2007 Acreage 652,016 2008 East Slide Rock Ridge Nevada 54,549 2008 Acreage 54,549

Figures 6-7 through 6-9, show MODI S fire detections for 2006, 2007 and 2008 in Calif ornia and Nevada and their proxim ity to the Jarbidge WA . The yellow depicts areas burned since January 1 st of each year. These m a ps were downloaded from the MODIS Active Fire Mapp in g Program website at http://activefirem aps. fs.fed.us/activefirem aps.php? op=m a ps&rCode=cgb

. Figure 6-7 shows the 2006 W i nters, Charleston Com p lex and Sheep fi re detections in northeastern Nevada. The Jarbidge W A is located in the no r t h east corner of Nevada, between the eas tern

- m ost large f i re show n in Figure 6-7 and the Idaho border. The IMPROVE m onitor JARB1 location is depicted in black. Recall that 2006 has a large OMC extinction component that m a y in part be due to these fires.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-19FIGURE 6-7

2006 MODIS FIRE DETECTIONS IN CALIFORNIA AND NEVADA

Figure 6-8 shows the Jarbidge WA surrounded by the 2007 Murphy Complex Fire detections on the west, no rth, and e a st where near ly two thirds of a m illion acres bu rned in this on e f i re

com p lex.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-20FIGURE 6-8

2007 MODIS FIRE DETECTIONS IN CALIFORNIA AND NEVADA

Figure 6-9 shows the 2008 East Slide Rock Ridge fire partially within the Jarbidge W A and burning out of the wilderness area to the east. This l ong-lived fire started as a lighting strike within the wilderness area and was allowed to burn as wi l d land fi re use fi re until it crossed out of

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-21the wilderness area and was partially suppresse d. The listed acreage do es not represent full containm ent of this fire, as of early Octobe r 200 8 and the acreage will likely increas e.

FIGURE 6-9

2008 MODIS FIRE DETECTIONS IN CALIFORNIA AND NEVADA

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-22Monitor data is not yet available for 2007 to a ssess the im pact of the Murphy Com p lex fire on visibility at the Jarbidge WA, nor is data for 2008 to assess the impacts of the East Slide Rock Ridge fire and the effects of the prolonged regi onal transport of s m oke fr om the 2008 northern California fires. Nevada suspect s the visibility impacts from na tura l f i res a r e not lim ited to OMC and EC e m issions, but include CM and SOIL e m issions due to windblown transport from the denuded burn areas which m a y persis t for years after a fire. Rehabilitation efforts on the Murphy Com p lex have been hampered by lo w soil m o isture conditio ns likely res u lti ng in sig n ificant local transport of particulates due to windblown dust. It is clear from Figure 6-6 that the relative extinction contribution of both OMC and CM increased sign ificantly in 2006. The relative contribution of EC and SOIL also increased, although less m a rkedly than OMC and CM. The extinction in creas es for these species are likely a result of the large acr eages burned in northern Nevada during 2006.

The 2006 monitoring data, pres ented in Figure 6

- 6, s how the visibility im pairm e nt res u lting from natural sources such as natural fire and wi ndblown dust overwhelm s the effects of em issions reductions resulting from additional control of Nevada’s anthropogenic em issions. Nevada anticipates a sim ilar result for 2007 and possibl y 2008 based on the active fire season in these
years.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-236.8 REFERENCES

U.S. EPA 2007. Guidance for Setting Reasonabl e Progress G o als under the Regional Haze Rule. U.S. Environm ental Pro t ection Age n cy, Of f i ce of Air Quality and Stand a rds, Resea r ch Triang le Park, North Carolina. June 1, 2007 rev.

U.S. EPA 2001. Guidance for Dem o nstrating Attainm e nt of Air Quality Goals for PM 2. 5 and Regional Haze, Draft Report. U.S. Environm enta l Protection Agency, Research Triangle Park, North Carolina. January 2, 2001.

U.S. EPA 2007. Guidance on the Use of Models and Other Analyses for De m onstrating Attainm e nt of Air Quality Goals f o r Ozone, PM 2. 5 , and Regio n al Haze-Draft 3.2. U.S. Environm ental Pro t ec tio n Agency, Of f i ce of Air Qu ality and Standards, R e sear ch Tria ngle Park, North Carolina. April, 2007.

NEVADA REGIONAL HAZE S T ATE IMPLEMENTATI ON PLAN, October 2009 6-24