### Attachment A 

### Request to Create a Nonattainment Area for the Morongo Indian Reservation



### EXECUTIVE SUMMARY

On November 6,2003, EPA modified theboundaries ofnonattainment areas in Southern California so that the Morongo Reservation "moved" fiom the Coachella Valley Nonattaiirment Area within the Salton Sea Air Basin to the South Coast Air Basin, which had a more restrictive ozone attainment designation. The State of California petitioned EPA on September 

### 27, 2007 to "bump up" the ozone ironattainnlent designation for the South Coast Air Basin from "severe-1 7" to "extreme." With regard tojurisdictional boundaries, EPA did not acknowledge the existence ofthe Morongo Reservation as a separate, sovereignjurisdictioil wllen the nonattahnent area boundary was changed in 2003, and did not recognize the major inlplications for the Tribe of moving the area boundary. The Tribe's ecoiloniic and governmental interests, specifically its inherent authority with respect to reservation air quality planning and its nascent regulatory and permitting authority under the Tribal Autllority Rule, were supposed to be protected by the EPA until the Tribe could fbrmally assume these responsibilities. 'This was not done, as evidenced by the lack of EPA consultation with the Tribe during the 2003 boundary change rulemaking, as required under Executive Order 13175 and the fderaltrust responsibility.
The Morongo Band ofMission Indians (Tribe) requests that EPA create a Morongo Noilattaininent Area that is geographically identical to the reservation. If that is not approvable for some valid reason, in the alternative the Tribe requests that EPA move the western boundary ofthe existing Coachella Valley Nonattainment Area to include the Morongo Resewation. Leaving the Molongo Reservation within tl~e South Coast Nonattainment Area will impose additional, unanticipated delays in developing Morongo's air program, including the Tribe's plan to implement a tribal air pertnit progranl for minor sources within the next year. First, by reducing the major source "potential to emit" thresh0ld for ozoneprecursor (i.e., NOx and ROC) emissions fiom 25 tpy to 10tpy under the 8-hour average ozone standard, the reclassification will increase the nuinba- of facilities potentially subject to Nonattainment New Source Rcview (NNSR) requirements, thus increasing the use and cost of Morongo staff resources, as well as facility resources. Sewitd, the number of future facilities subject to Title V would be significantly increased if the threshold of25tpy is reduced to 10tyy. Finally, under the cui~ent nonattainment area designation, the threshold for the applicability of General Confornlity requirements is similarly 10 tyy, requiring many more projects to dcmonstratc that their emissions of criteria pollutants will not impede progress toward attainment with national ambient air quality standards.For both existing facilities and futurefacilities subject to NNSR, there 

### is currently no system 

### in place through which such facilities can obtain emissionreduction credits. Unless EPA allows such sources to use emission reduction credits fiom the adjacent air basins, either through its own program or through a tribal permitting program, such facilities will be placed at a disadvantage relative to similar facilities operating outside of the Reservation.
Based on the nine factors suggested 

### in EPA guidance, analysisofthe relevant technical data support establishment ofthe Momngo Reservation as its own nonattainment area. 

### If EPA believes that a separatenonattainment area is not legally defensible, then the Morongo Reservation should be made a part ofthe Coachella Valley Nonattainment Area. The factor ofjurisdictional boundaries suggests that the reservation should logically be its own nonattainment area The factors pertaining to low population density and lack ofurbanization, meteorology, geography, hydrology, and level of emission source control show that the reservation 

### is substantially different than the South Coast Air 

### asi in,' and holds more in common with the Coachella Valley Nonattainment Area. The remaining factors dealing with air quality, causes ofnonattainment, lack of local emission sources, low level of local trac, and growth rates ae neutral on commonality with either the Coachella Valley or South Coast Nonattainment Areas, and hence EPA should treat these factors as supportiveofthetribal request to make the Morongo Reservation its own nonattainment area.



### INTRODUCTION
On November 6,2003, the U.S. Environmental ProtectionAgency (EPA or Agency) modified the boundaries ofthe Salton Sea Air Basin (SSAB), so that the Morongo Reservation "moved" from the CoachellaValley Nonattainment Area 

### in the SSAB to the South Coast Air Basin (SoCAB), which had a more restrictive ozone attainment designation. One ofthe importantparameters that this action changed for the Morongo Band ofMission Indians (Tribe) 

### is that the major source definition threshold droppcd horn the previous 25 tons per year (tpy) level down to 10tpy. That change to the lower major source threshold is fiuther exacerbated by the September 27,2007 request fiom the South Coast Air Quality Management District and the State of california2that EPA "bump up" the nonattaimnent designation ofthe SoCAB fiom "severe-1 7" to "extreme" with respect to the 8-hour average ozone standard. Keeping the Morongo Reservation 

### hi a nonattainrnent area with such a restrictive major source threshold means that the Tribe cannot implement a meaningful Minor Source permitting program because the regulation would be applicable only to a small set of potential future emitting sources whose emissionswould be lower than 10tpy ofboth

I 'IheSouth CoastNonattainment Area is geographically identical to the South Coast Air Basin. %e South Coast Air QualityManaganent Distlict described the request in the June 1,2007 Roardapproved2007 Air QualityManagement Plan, and initiatedthe requcst September 27,2007. The Califon~ia Air Resources Board (ARB) passed Resolution07-41on September 27,2007 to forw~d the request for redesignation to EPA.NOx and VOC. Several additionalyearswill be needed for the Tribe to develop a Major Source permitting program and gain approval fir such a program from EPA. During this interim period, the Tribe would not have permitting authority over its own Morongo Casino Cogeneration Plant, which now operates under EPA's Part 

### 7

### 1 Title V permitting authority.
Tl~e purpose ofthis document is to present the logical and technicallybased rationale tbr 

### EPA to create a Morongo Nonattainment Area. It will be shown that the reservation has substantial diffwences fiorn the South Coast Air Basin and warrants its own nonattainment 

### area. It makes no sense for the reservation to remain inside the South Coast Nonattainment Area, which is the principal sourceofthe emissions that cause the monitored violations ofthe ozone National Ambient 

### Air Quality Staadards(NAAQS) on Tribal lands, and EPA has authorityunder Clean Air Act Section 11 0(k)(6) to create a Morongo Nonattainment Area. At a minimum, EPA should adjust the Coachella Valley Nonattainment Area boundary to include the Morongo Reservation.



### RATIONALE
The following discussion is organized according to the nine factors, taken fkom USEPA guidance.
Factor I : "Air aualitv data" Ozone, generated by atmospheric reactions of its precursor einissions ofNOx and VOC over periods ofhours, is by its nature a regional pollutant. High levels that exceed the 

### 8- hour ozoneNAAQS are widespread throughout the SoCAB, 

### an4 because of'the overwhelmingly dominant role of transport: are also widespread throughout the Reservation and the Coachella Valley Nonattainment Area, sls well as the rest ofthe SSAB.
As can be seen in Figure 1, the average annual number of exceedances ofthe current 8- hour ozone NAAQS is highest at the Redlands monitoring station, and similarly high at the two stations west on the 

### SOCAB' side of Redlands and four of the five stations to the east of Redlands 

### (see Figure 2 forthe locations of the monitoring stations). The 11-year average of 32 exceedances measured at the Indio monitoring station are substantial, but only half the number measured at the other monitoring stations. Figure 

### 3 shows that the relative magnitude and temporal trends ofthe number of ozone exceedances are

USEPA. Apes Designutiom for the 2008 Revised Ozone National Ambienr Air Qudi{vS~undurds, memorandum from Robert J. Meyers, Principal Deputy Assistant Administrator, Office ofAir and Radiation, to Regional A&ainistrators,Dece~nber 8,2008. South Coast Air QualityManagement District (SCAQMD). Air QualityManagement Plan, Chapter 8 .- Future Air Quality - Desert Nonattainmenthens, 1997, httpr//www.aqmdgov/aqmp/97aqmp/chapter,~/mc~I<JJ&. htfPll.

The Morongo Reservation and monitoring station are currentlylocated in the South CoastAir Basin and South Coast Noiutttainment Area.

### comparable for most ofthe stations, especially 

### in 2005 when the highest 

### number of' exceedances were recorded at Banning, Palm 

### Springs, Joshua Tree, and Riverside. Figure 4 

### shows that the average annual maximum 8-hour ozone concentration is relatively uniformbetween the monitoring stations, and the highest occurs at Redlands. Figure 5 

### shows the relatively unifbrm and synchronous temporal changes between the stations from 

### year to year. Similarly,Figures 

### 6 and 

### 7 show the same uniformity between stations and fiom year to year of the annual 4" 

### highest 8-hour ozone concentrations, respectiveIy.

~ecause the spatial pattern ofthese stations coversboth the east side of the SoCAR and 

### Coachella Valley Nonattainment Area, the magnitude and temporal pattern ofozone concentration suggest that the Morongo Reservation should be established 

### as its own 

### nowattainment area.

### Figure 1. 

### Average Annual Number of Excedances of the 8-Hour Ozone NAAQS

### (0.075 ppm) from 1998-2008

l

Riverside Perris BB Redlands .Banning I# Morongo* @ Palm Springs 199 Joshua Tree NM*' @ lndio

j South Coast MonattainmentArea CoachellaValley NonattainmentArea
i 

## +-------------------------- ---I---------------- 90 .\"..."."- --"
,-- .)

* Dataforthe Morongositeonty existfor 2006-2W8. * Full site name isloshuaTree National Monument (A05 site #0607190023. Notes:The vertical line acmssthe topof each barrepreseneonestandarddeviationaround the arthmetic mean. The Joshua TreeMational Monument datafor 203wereexduded bmusetheywere very incmsistent with the other yearsand sitesand appear erroneous.

### Figure3. 

### Average Annual Number 

### of Exceedances 

### of the 8-Hour Ozone NAAQS (0.075 

### ppm) by 

### Year Normalized to Redlands

-- 

## - .."..*." - - -" " 1-60 

# - -- - 

### - 

### ---

........................ 0.oo .r-7-. TI- --Riverside -B-Redbnds -$+?-Banning 44- Morongo --*Joshua Tree NM +Palm Springs

Notes:The Perrlsdatawereexdded due tohlghvolatjlityof theconmtrationsfrom year-to-year,makingcomparisomwiththeothersitesd~fficult. me JoshuaTreeNMdatafor ZOQI wereexcludedbecausetheywere very inconsistentwiththeother yearsandsitesandappearerroneous. The Indiodatawereexcludedduetothemuch lower number ofexceedancesand thelowcorrelationwiththeothers~tes.

### Figure4. 

### Average Annual Maximum 8-hour Ozone Concentration from 1998-2008

l

Riverside gl Perris @ Redlands l Banning B Morongo* @ Palm Springs Joshua Tree NM** @ lndio 160

....................... I " " I South Coast NonattainmentArea CoachellaValley NonattainmentArea 

### 4----------------- 

# ---- i-------------- 

## + j

* Dataforthe Moronga siteonh/exlstfor 20C16-2008 * Full wtename isJc6huaTreeNational Monunent(AQZsite#U60719002). NQes:lhe vertical line acrossthetopof each barrepresentronedandarddeuiationaroundthe arlhmetic mean. The Joshua Tree National Monument data for 2031 wereexduded because theywe~every irronsistentwith theotheryearsandsites and appearerroneous.'~~Io~uoJJ~ Jeadde puesq!s pueSJeah~wl0 aqjq8~ walgsuox! A~ah aam Aaq~asnmaq papnlnaaJaMTOOZ JoJeIePWNaaJ1 enqsor au ~qm!y!psa~!sjq~oaqjq~!Mwosyedcuo~Bu!qew ~~~~-~J-J~~~~oJ~su~~wu~uo~J~~~o~~~&~~o~@!~o~ snp PaPnPxaan* elePgJJadaU:saloN 8002 LOO2 9002 SO02 PO02 FOOZ ZOOZ T 002 0002 6665 8661:

........ ! i A "L L ! 

### t 00.0 I

-..-..--.,,.. ....... ..............-.. 

# .--I ovo 

# E 3

1 

## I 0,

### Figure6. 

### Average Annual 

### 4th Highest 8-hour Ozone Concentration Averages from 1998-2008

Ei Riverside aD Perris @ Redlands lBl Banning Bi Morongo* I Palm Springs IJoshua Tree NM** @ lndio 160 .r......---.--- i i South CoastNonattainmentArea ellavalley NonattainmentArea
I 

# ----------------

" --..-.. -

### --
............... "."".".--

Data for the Morongosite only existfor 2006-2008 

### " Full site name isJoshuaTree National Monument(AQSsite#060714)02). Notes:Theverticalline acrossthetopof each barrepresentsonestandarddeJatlonaroundthe artthmetk mean. The JoshuaTree National Monumentdatafor 2Mn wereexduded bemusetheywere veryinconslstentwhh the other year sand sites and appear erroneous.

### Figure7. 

### Annual 4th

### Highest 

## 8-hour Average Ozone Concentration Normalizedto Redlands

E 

# : 8 1.00
U) u c -+-Riverside a G +Redlands 

### 2 o 0.80 w +Banning C 0 

### f -4- Morongo 

# - E 

### --"

.......... .- .......................................................... --*Joshua Tree NM 9 0.60 PalmSprings
-+- lndio

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Notes:ThePerrisdatawere excluded due tohighvolatility oftheconcentrationsfrornyear-to-year, rnakingcomparlsonswlththe othersitesdlftlcult. The JoshuaTreeNMdata for 2001wereexcludedbecausetheyweix very inconsistentwiththe otheryearsand sitesandappear erroneous.

### Factor 2: 

### ffEmissions data (location of sources and contributionto ozone concentrations')''
Due to the sparsepopulation ofthe Morongo Reservation, the limited emissions f?om the few sources on the Reservation are close to only 

### a few nearby receptors. This same sparse distributionof emission sources and nearby receptors characterizesthe other Indian reservations and communities located throughout most ofthe 

### SSAB. The greater Palm 

### Springs area, which contains the densestpopulation within the SSAB, is itself relatively isolated fhmother SSAB communities, and covers a small fiaction of the SSAB's surface. Far 

### different is the closeproximity ofthedense residential areas ofthe SoCABto transportation, commercial, and industrial emission sourcesclustered 

### in the urban 

### centers of the SoCAB, including not only the Los Angeles CMSA, but also the 

### nearby Riverside-San Bernardino-Ontario Metropolitan StatisticalArea.
Table 

### 1 presents 

### a comparison of emissions fiomthe Morongo Reservation and two portions ofRiverside County in 

### the SoCAB and SSAB, separated into stationary, 

### area, and mobile source categories. The emissions 

### in both the SoCAB and SSAB portions of 

### RiversideCounty are well in 

### excess ofthe 

### emissionson Tribal lands and, as a 

### result, these data suggestthat the Morongo Reservation shouldbe 

### established as its own noilattahment area.Factor 3: "Po~ulation de~lsitv and demee of urbanization (including commercial development)"
The Morongo 

### Band ofMission Indians has a low population (see Table 2), a low population density throughout the reservation, and 

### a general lack ofurbanization. These same characteristics of the Morongo Reservation are found throughoutmuch of the Coachella Valley Nonattainment Area and the larger SSAB, exccpt within the fast-growing retirement cities such as Palin Springs and PaInl Desert. As one moves west fromthe Morongo 

### Reservation, population density and degree 

### ofurbanization 

### ~apidly increase upon reaching the nearby Riverside-Sari Bernardino-Ontario Metropolitan Statistical Area, and reach the highest levels found 

### in the Los Angeles CMSAupon

### moving furtl~er 

### west towards the coat. Table 

### 2 sl~ows the population density ofthe Morongo Reservation, Coachella Valley, Riversidesan Bernardino-Ontario Metropolitan Statistical Area, Riverside County, Los Angeles County, and Los Angeles-Long BeachSanta Ana Metropolitan StatisticalArea The population density on the reservation is far lower than that 

### in 

### any of the other nearby geographicalareas, and is closestto that found in the Coachella Valley within the CoachellaValley Nonattainment Area. 

### Thus, from

### the perspective ofpopulation density and degree of urbanization, the data support establishmentof the Morongo Reservation as 

### its own nonattainment area.

Reservation. Growth rate based on estimate of375 residencesand annual increase of2-3 (mail fiom Director, Environmental ProtectionDepartment, Fehy 17,2009). Coachella Valley, California,h~~:l/www.city-data.com/citylCoachella-Valley-Cali~mia.html "Coachella Valley Fxonnrnic Partnership,Poptrlation Trends, data br2005, http://cvq.comlpop-traids.dim1.

MSA

# - Metropolitan StatisticalArea. US Cwsus Bureau. QuickFacts,http:l!quickf8cts/census.gov. 'USEPA. Letter fio~n Wayne Nastri, Ado~inistrator, Region 9, to Martin Robert, Chairperson, Moi-ongo Bald ofMission Indians, August 21,2008, http://www.epa.gov/prndesignationsl2006b~andarddrec~ettersrT~M0~ongo~Band~of~ Mission-Indians-EPA



### Factor 4: 

### "Traffic and 

### commutinp vattern"
Traffic and 

### commutingthroughout most of the Morongo Reservation are 

### at 

### low levels, while non-tribal regional traffic and commuting 

### are dominated by the 

### presence of Interstate 10 

### crossing through the 

### Banning Pass on the southern boundary ofthe reservation (see Table 3). 

### Similarly, traffic and 

### commuting levels throughout most of the SSAB are light, but heavy traffic is 

### concentratedon 1-10, 

### especially where it is 

### adjacentto thc Palin Springs to Palm Desert con-ictorofresort hotels and residentiaI developments. Moderate levels oftraffic and commuting 

### are found in the SSAB along State Highways 86 and 1 11 (see Table 3) running 

### fromthe north 

### end ofthe Salton Sea southeast dong the west and east sides ofthe 

### sea, respectively, 

### and into Imperial County.
The SoCAB, 

### in comparison, is characterized by the highest levels oftraffic and commuting found in the nation. These high levels are found throughout the basin, including on the road system in nearby 

### SanBemardino 

### and Riverside. In fact, the eastwest traffic on interstate-levelhighways 1-10, SR60, 

### and SR91 

### is concentrated onto the 1-10 alone at the east end of the SoCAB because Banning Pass 

### is the only major east exit fioin the basin into the 

### SSAB. Table 

### 3 provides traffic counts from several key roads in the geographical 

### areasunder consideration. The low levels oftrafic throughout the reservation 

### are: Inore consistent with the lower levels of traffic found onnon-fi-eeways

### in the SSAB 

### and the SOCAB(e.g., see lower levels oftravel observed on SH-86 and SH-I 11 in the SSAB and SH-74 

### in the SoCAB). Freeway traffic levels are much higher than non-freeway traffic levels 

### in both basins.

IAvemge &i!y TruckTrqfficon

Factor 

### 5: "Growth rates and oattems"
Both the Morongo Reservation and the adjacent Coachella Valley 

### are mostly open space, containing relatively isolated communities connected by Interstate 

### 10

### and a few other major roads. Because both areas 

### are home to only a few iildustries, their growth is tied to infrequent special developments such 

### as the Morongo Casino and retiree residential projects.
As can be seen in Table 

### 2, population growth has been high throughout Riverside County onboth sides ofthe Morongo Reservation, while low onthe reservation (and 

### in the Los Angeles-Long Beach-Santa 

### Ana MSA).Factor 

### 6: "Meteoroloev (weather/traflsp~-t patterns)"
The meteorology and climatology ofthe Morongo Reservation, like its air quality, are dominated by the transport of air from the SoCAB, essentiallythe same asthe continuation of the same transport through the CoachellaValley exceptthat higher winds across the reservation result from its proximity to Banning Pass, which funnels air flow between the basins (i.e., relatively low speed daily seabreeze fiom the west, and relatively high speed wintertime SantaAna desertwinds from the east). The SoCAB is characterized by a substantial 

### frequency ofmarine layer accompanied by calm winds under an inversion that leads to cooler temperatures, but higher concentrations of pollutants. The reservation rarely experiencesthe coastal marine layer, and the Coachella Valley and SSAB never experience it. Consequently, the Morongo Reservation

### has meteorology more similar to that ofthe Coachella ValleyNonattainment Area than to most ofthe South Coast 

### Air Basin. Meteorologyand atmospheric transport characteristics suggest that the reservation should be its own nonattainlnent area.

Factor 

### 7: "Geo~m~hy/to~omaph~ (mountain ranges or other air basin boundaries)"
Because geography and topography are important factors 

### in defining 

### the boundaries of the SoCAB and SSAB, the Morongo Reservation clearly has 

### far more 

### in common with the SSAB. Most ofthe SoCAB is a coastalarea heavily influenced by the proximity of the Pacific Ocean and generally westerly flow of air, accounting for the fiequent sea breezes duringthe day and strength ofthe marine layer. In contrast, the ringing ofthe SoCABby the San Gabriel, San Gorgonio, and San Jacinto mountain ranges prevents this marine layer from affecting the environment that dominates from the Banning Pass through the Morongo Reservation and eastward-southeastward through the entire SSAB.
On the large spatial scale ofhydrologicregions, the Momngo Reservation is located within the Colorado River Basin Hydrologic Region, one of the ten hydrologic water study areas of Califoniia. The Colorado River Hydrologic Region has 

### as its western boundarythe crest ofthe 

### San Bernardino, San Jacinto, SantaRosa, and Peninsular Ranges, separating it completely fiom the South Coast Basin Hydrologic Region.
Witlun this Region therc are planning areas 

### and hydrologic units 

### and subunits. The Morongo Reservation is situated directly within the San Gorgonio Hydrologic Subunit of the Whitewater Hydrologic Unit 

### (WHU). The Whitewater River watershed (from which the Tribe derives 

### its surGcewater rights) is generally situated 

### in Riverside County within the Coachella Valley Planning 

### Area of the Colorado 

### River Basin Regional Water Quality ControlBoard. The Whitewder watershed 

### is generally defined by the boundaries ofthe WHU, as 

### described in the Water Quality Control 

### Plan for the Colorado River Basin, Region 

### 7 

### (2006). The Whitewater River Watershed Municipal Stormwater 

### Program Stonnwatcr Management 

### Plan (2001-2006) descriies the watershed 

### as follows: "much 

### ofthe watershed consists of sparselypopulated mountains, 

### desert, and agricultural lands. Urbanized areas are principally located on the valley floor between Banning and Indio along Interstate 10, and fkom Palm Springs to Coachella along StateHighway 

### 1

### 1 1

### ."

### The western boundaries ofthc above-refaenced planning 

### areas and hydro logic units generally coincide with or are slightlyto the west 

### ofthe Morongo 

### Reservation's western boundary, thus 

### making it clear that, fiom a geographic and hydrological standpoint, the Reservation has more 

### in common with the Salton Sea Air Basin than the South Coast Air Basin.
This information serves to emphasizethe connectionbetween the Reservation and the Coachella Valley Area The Reservation and Coachella Valley luve surfacewater rights that derive from the 

### same watershed (Whitewater)and share groundwaterthat flows in 

### a generally southeasterly direction spilling fiom the San Gorgonio Basin aquifer into the CoachellaValley. Geography, topography, and hydrology information all suggest that thc reservation should logicallybe its om nonattainment 

### area.

Factor 8: 

### "Jurisdictional boundaries (ex.. counties. air districts. existing nonattainment areas. Reservations. metropolitan olanninn organizations(MPOs)"
The most importantjurisdictional boundaries for nonattainment area definition and designation in 

### the vicinity ofthe Morongo Reservation are those of the reservation itself, and that between the SoCAB and 

### SSAB. The boundary between San Bernardino and Riverside Counties 

### is locatedjust a short distance north of the northern boundary 

### ofthe reservation Jurisdictional aspects of the requested change in boundary are simplifiedby the following hcts:
The reservation and the CoachellaValley Nonattainment 

### Area are both located in the commonjurisdiction of Riverside County; and
Air quality management responsibilitiesofthe South Coast Air Quality Management District forthe South Coast Air Basin and the Coachella Valley NonattainmentArea will not change whether the reservation is located within the former or 

### latter portions ofthe District's jurisdiction.
Jurisdictional boundaries suggest that the reservation should logjcaltybe its owl nonattainment 

### area With regard tojurisdictional boundaries, EPA did not acknowledgethe existence ofthe Morongo Reservation as a separate, sovereignjurisdiction when the nonattainment area boundary was changed in 2003, 

### and did not recognize the major implications for the Tribe ofmoving the areabou~ldary.The Tribe's economic and 

### governmental interests, specifically its inherent authoritywith respect to reservation air qualityplanning and its nascent regulatory and permitting authorityunder the Tribal AuthorityRule, were supposed to be protected by tl~e Agency until the Tribe could formally assume these responsibilities. There 

### was no EPA wnsuttation with the 

### Tnbe during the 

### 2003 boundary change rulemaking, as was required under Executive Order 

### 13175 and the federal trust responsjbilit

### y.Factor 9: ''Level of control of emission sources"
The key differencebetween the level of control of emission sources is that a source in the Coachella Valleyportion ofthe SSAB must emit at least 25 tons per year of a nonattainment criteria pollutant or precursor to be subject to the inore stringent federal New Source Review and Title V federal operating permit requirements for a major source, compared to the requirements for a minor source, whereas sources in the SoCAB emitting only 

### 10tons per year or more of a nonattainment criteria pollutant or precursor are subject to the more stringent requirements for major sources. Mobile source emission controlrequirements are identical in the SSAB and SoCAB. As indicated above, 

### air quality on the Morongo Reservation is dominated by transport from the SoCAB, where the 10ton per year federal threshold applies. Large emission reductions are needed in the SoCAB to allow that air basin to make reasonable further progress towards attainment, and also to allow the SSAB to reach attainment because of the dominant role played by transport fi-omthe SoCAB into the SSAB. Only a modest level of emission reductions 

### is needed fiom sources on the Morongo Reservation and throughout the 

### SSAB to prevent local sources ftom impeding reasonable further progress towards attainment.



### CONCLUSION
Based on the nine kctors suggested 

### in EPA guidance and analysis ofthe available data, the Morongo Reservation logically and technically shouldbe its own Morongo No~lattainment Area tlut is geographically identicalto the reservation. The factors pertaining to low population density and lack ofurbanization, meteorology, geography, hydrology, 

### and level of emission source control show that the reservation is substantially different than the South Coast Air and holds more in common with the Coachella ValleyNonattainrnent 

### Area. The remaining factors dealing with air quality, causes of nonattainment, lack of local emission sources, low level of local traffic, and growtl~ rates are neutral on commonality with either the Coachella Valley or South Coast Nonattainrnent Areas, and hence it 

### EPA should treat these factors 

### as supportiveofthe tribal request to make the Morongo Reservationits own nonattainment area. Leaving the Morongo Reservation within the South Coast Nonattainment Area will impose additional, unanticipated delays 

### in developingMorongo's air program, including the Tribe's plan to implement a tribal air permit program for minor 

### sources within the next year. First, by reducing the major source "potential to emit" threshold 

### krozone precursor (i.e., 

### NOx and ROC) emissions from 

### 25 tpy to 

### 10tpy under the 8-hour average ozone standard, the reclassification will increase the number of fkcilitiespotentially subject to Nonattainment New Source Review requirenlents, thus increasingthe use and cost of Morongo staffresources, as well as facility resources. Second, the number of

"fie South Coast Nonattainlncnt Area is geographicallyidentical to the South CoastAir Basin.

### future facilities subject to Title V would be 

### significantly increased becausethe 

### threshold of25 tpy is 

### reduced to 10

### tpy. Finally, reducing 

### the threshold for the applicabilityof General Confbrmityrequirements 

### &om 

### 25 tpy to 10 

### tpy would 

### require many more projects to demonstratethat their emissions 

### ofcriteriapollutants

### will not impede progress toward 

### attainment with national ambient 

### air quality standards.