### March 9,2009

Carol Rushin, Acting Regional Administrator

United States Environmental Protection Agency - 

### Region 8

80C-EISC

1595 Wynkoop Street Denver, CO 80202- 1 129

Re: Area Designation Recommendation for 

### 2008 Revised Ozone NAAQS

Dear Ms. Rushin:

Thank you for your letter inviting the Southern Ute Indian Tribe to participate in the process of designating areas for the 2008 revised ozone national ambient air quality standards.

Under section 107(d)(l) of the Clean Air Act, areas may be designated as "nonattainrnent" (if the

area does not meet the standards or contributes to ambient air quality in a nearby area that does

not meet the standards), "attainment" (if the area meets the standards), or "unclassifiable" (if the

area cannot be classified on the basis of available information as meeting or not meeting the standards).

EPA's guidance on the area designations for the 2008 revised ozone standard lists nine

factors that states and tribes should consider in making recommendations for area designations

and on which EPA will base its designations. With regard to the factors to be considered in determining nonattainment area boundaries, the guidance provides that "a state's or tribe's demonstration supporting their boundary recommendation for an area should show that: 1)

violations are not occurring in nearby portions that are excluded from the recommended area, and 2) the excluded nearby portions do not contain emission sources that contribute meaninnfully to the observed violations." (emphasis added). In 

### carrying out its responsibility for designating areas in Indian country, in addition to the factors listed in EPA's guidance document, EPA must consider the federal policy of encouraging tribal self-determination and economic development, and environmental justice must be considered too. EPA 1984 

### Indian 

### Policy (providing that "in keeping with the Federal trust responsibility, [EPA] will assure that

tribal concerns and interests are considered whenever EPA's actions andlor decisions may affect

reservation environments.")

Based on our 

### evaluation, set forth 

### in the attached Technical Support Document, 

### of air quality data, emissions data, and other factors which, according to EPA guidance, should be

considered in making recommendations for area designations, the Tribe recommends that the

P.O. Box 737 + IGN.~CIO, CO 81137 + PHONE: 970-563-0100

### area within the exterior boundaries of the Southern Ute Indian Reservation be designated as "attainment/unclassifiable" 

### for the 2008 revised ozone NAAQS. Additionally, based on our determination that the contribution, if any, from Reservation-based sources to the violation of the
standard in northwest New Mexico is not meaningful, the Tribe recommends that the

Reservation not be included in the "nonattainment" area that is likely to be designated for San

Juan County, and perhaps Rio Arriba County, in New Mexico as a result of the ozone violating

monitor located in New Mexico near Navajo Lake. 

### In other words, no violations of the revised

ozone standards are occurring on the Reservation and the sources of air pollution located on the
Reservation do not contribute meaningfully to the monitored violation at New Mexico's Navajo
Lake monitor.

Please contact Vickie Kujawa (Environmental Programs Division Head) (970) 563-01 35

or James Temte (Air Quality Program Manager) at (970) 563-4705 or Sam W. 

### Maynes (Tribal attorney) at (970) 247-1755 if you have any questions about the Tribe's recommendation and

Technical Support 

### Document.



## L

Encl. Technical Support Document

cc: Southern Ute Indian TribeIState of Colorado Environmental Commission

Martha 

### E. Rudolph, Director of Colorado Environmental Programs Paul Tourangeau, Colorado Air Pollution Control Division Director Douglas A. Lempke, Colorado Air Quality Control Commission Administrator Mary Uhl, New Mexico Air Quality Bureau Chief

Ernest House, Sr., Chairman, Ute Mountain Ute Tribe Scott Clow, Environmental Programs Director, Ute Mountain Ute Tribe Joe Shirley Jr., President, Navajo Nation Stephen B. Etisitty, Navajo Nation Environmental Protection Agency Levi Pesata, President, Jicarilla Apache Nation

Cordell TeCube, Director, Environmental Protection Office, Jicarilla Apache Nation La Plata County Colorado Board of County Commissioners

Archuleta County Colorado Board of County Commissioners

Montezuma County Colorado Board of County Commissioners


### State Senator Jim 

### Isgar State Representative Ellen Roberts

U.S. Senator Mark Udall

U.S. Senator Michael Bennett Interior Secretary Ken Salazar

## SOUTHERN UTE INDIAN TRIBE

Technical Support Document For 2008 Revised Ozone NAAQS Area Designation Recommendation

March 10, 2009

Southern Ute Environmental Programs Division Air Quality Program

116 Mouache Dr.

P.O. Box 737 Ignacio, Colorado 81137i TABLE OF CONTENTS Page No.

List of Tables ................................................................................................................ ..... iii

List of Figures ............................................................................................................... ..... iii

I. Introduction ..............................................................................................................1

II. Nine-Factor Analysis ...............................................................................................3

Factor 1. (Air Quality Data) ..................................................................................3

A. Monitoring Data Show Attainment for the Reservation ..............................3

Factor 2. (Meteorology) ........................................................................................6

A. Photochemical Source A pportionment Modeling Shows that

the Contribution of Reservati on Sources to Ozone Formation in Northwest New Mexico is Not Meaningful .................................................6

B. Wind Roses Show Prevailing Winds Over the San Juan Basin

Blow From the West and Southwest ..........................................................17

Factor 3. (Emissions Data) ..................................................................................24

A. Ozone Precursor Emissions from Reservation Sources are only a

Small Portion of Ozone Precursor Emissions in the Four Corners Region ..........................................................................................24

B. Emissions Data Show That Large Engine Sources on the Reservation Already Have Low NOx Emissions ...........................................................28

Factor 4. (Level of Cont rol of Emission Sources) ..............................................29

A. Existing Regulatory Fr amework on the Reservation .................................29

B. Existing Sources on the Re servation are Well-Controlled .........................29

C. Tribal Efforts to Assume Regulatory Responsibility Will

Result in Better Control of S ources and Decreased Emissions .................30ii TABLE OF CONTENTS Page No.

Factor 5. (Growth Rates and Patterns) ................................................................34

A. Existing Development ................................................................................34

B. 80-Acre Infill Development .......................................................................34

C. A Nonattainment Designation Based on Possible Future Development is Inappropriate Since NOx Emissions from Reservation Sources (and, Hence, Ozone Levels on the Reservation) are Expected

to Decrease Over the Ne xt 20 Years Notwithstanding Infill Development. ....................................................................................35

Factor 6. (Jurisdictional boundaries) .....................................................................38

A. Control of Emission Sources in a Regional Nonattainment Area Would be Spread Among Multip le Jurisdictions and (1) is Unnecessary, (2) Could Slow the Tribe’s and Environmental Commission’s Implementation of Air Pollution Control Measures, and (3) Would Not Efficiently and Effectively Serve the Purpose of Improving Air Quality ...............................................................................38

B. The Reservation is Already a Separate Air Quality Control Region .........39

Factor 7. (Geography/Topography) ......................................................................41

Factor 8. (Population Density and Degree of Urbanization) ................................42

Factor 9. (Traffic and Commuting Patterns) .........................................................44

III. Other Factors ..........................................................................................................44

A. EPA Must Consider Tribal Se lf-Determination in Making its Area Designation for the Reservation .................................................................45

B. Environmental Justice Favor s an Attainment/Unclassifiable Designation for the Reservation .................................................................45

C. In the Alternative, Ongoing St udies May Warrant an Unclassifiable Designation for the Reservation .................................................................46

IV. Conclusion .............................................................................................................46iii LIST OF TABLES Page No.

Table 1: Southern Ute Indian Reserv ation Ozone Monitoring Data Summary ...............3 Table 2: Average Predicted Hourly O 3 (ppb) for all Hours Above

Indicated Threshold at th e Navajo Lake Monitor ............................................ 15

Table 3: Total 8-hour Ozone Pred ictions and Corresponding SUIT Impacts for High Impact Days ......................................................................... 16 Table 4: Summary of Regional NOx and VOC Emissions in the Four Corners Area 4C-4km Domain Emissions Summary (t/yr)......................................25-26

Table 5: Distribution of Reciprocating Internal Co mbustion Engines on the

Reservation in 2005 that Process CBM Gas .................................................... 28 Table 6: Summary of Conclusions Regard ing Additional Contro ls on Oil and Gas Natural Gas Fired Engines ............................................................................... 30 Table 7: Reservation Demography – Es timated Population on Reservation ................. 42 Table 8: Reservation Demography - Estimat ed Population Growth on Reservation ..... 42 Table 9: Estimated Total Square Miles on the Reservation ........................................... 43 Table 10. Estimated Population Density on the Reservation ........................................... 43

Table 11: Emissions from Vehicle Tr avel on Paved Roads within the Reservation Boundaries (tons) ......................................................................... 44

Table 12: Emissions from Vehicle Travel on Unpaved Roads within the SUIT Reservation Boundaries (tons) ......................................................................... 44

LIST OF FIGURES

Figure 1: Ute 3 2006-2008 Ozone Monitoring Data .........................................................4 Figure 2: Ozone Monitor Locations in the Four Corners Region .....................................5 Figure 3: Hourly Time Series for Na vajo Lake Monitor for April 2005 ...........................8 Figure 4: Hourly Time Series for Navajo Lake Monitor for May 2005 ............................9 Figure 5: Hourly Time Series for Na vajo Lake Monitor for June 2005 ............................10 Figure 6: Hourly Time Series for Na vajo Lake Monitor for July 2005 ............................11 Figure 7: Hourly Time Series for Na vajo Lake Monitor for August 2005 .......................12 Figure 8: Hourly Time Series for Na vajo Lake Monitor for September 2005 ..................13 Figure 9: Hourly Time Series for Nava jo Lake Monitor for October 2005 .................... .14 Figure 10: 2008 Annual Wind Roses in the Four Corners Area ....................................... 19 Figure 11: 2008 Annual Daytime Wind Roses .................................................................. 19 Figure 12: 2008 Annual Nighttime Wind Roses ............................................................... 20 Figure 13: 2008 Spring Wind Roses ................................................................................. 20 Figure 14: 2008 Summer Wind Roses............................................................................... 21 Figure 15: 2008 Summer Daytime Wind Roses ................................................................ 21 Figure 16: 2008 Summer Nighttime Wind Roses ............................................................. 22 Figure 17: 2008 Autumn Wind Roses ............................................................................... 22 Figure 18: 2008 Winter Wind Roses ................................................................................. 23 Figure 19: Relative Contribution to Total NOx Inventory ................................................ 27 Figure 20: Relative Contribution to Total VOC Inventory ............................................... 27 Figure 21: Estimated Production Volume by Year ........................................................... 36iv Figure 22: Actual NOx Emissions from Engines .............................................................. 37 Figure 23: Geography of the Southern Ute Indian Reservation........................................ 411 I. Introduction.

Pursuant to section 107(d) of the Clean Air Act, EPA must designate areas as “attainment,” “nonattainment,” or “unclassif iable” whenever a ne w or revised NAAQS is promulgated. In making area designations, EPA guidance provides that the following nine factors, as well as any other releva nt information, will be considered:

• Air quality data

• Emissions data

• Population density and degree of urbanization

• Traffic and commuting patterns

• Growth rates and patterns

• Meteorology

• Geography/topography

• Jurisdictional boundaries

• Level of control of emission sources

This technical support document analyzes the ni ne factors identified a bove, as well as other relevant information, and is provided in s upport of the Tribe’s r ecommendation that the Reservation be designated “ attainment/unclassifiable ” and not be included in any nonattainment area that may be de signated for northwest New Mexico. 1

In support of the Tribe’s recommendation, this technical support doc ument includes data and analysis performed by Air Quality Res ource Management and ENVIRON International Corporation, under contract with the Tribe. ENVIRON’s work has included conducting a stateof-the-art three-dimensional multi-scale photochemical/aerosol grid modeling study using

ENVIRON’s Comprehensive Air Quality Model with Extensions ( CAMx , v4.51). An approach using ENVIRON’s CAMx model is more robust than performing qualitative analyses using the NOAA HYSPLIT back trajectory model. The HYSPL IT model provides an estimated flow only at one layer of the atmosphere, and in addition there is uncertain ty regarding the accuracy of the flow in complex terrain (as in the case of the Na vajo Lake monitor). By contrast, the use of a photochemical grid model in conjunction wi th fine scale MM5 meteorological modeling provides a complete and accurate picture of tran sport in the region within the mixed layer and provides a quantitative estimate of potential im pacts that include the non linear chemistry of

ozone formation. This work is similar to the modeling analysis of ai r quality and air quality related values impacts within the Four Corners region that is currently being conducted by ENVIRON for the Four Corners Air Quality Gr oup (formerly known as the Four Corners Air Quality Task Force) under contract with th e New Mexico Environmental Department.

Importantly, and as further explained below, ENVIRON’s CAMx model results show that there is no meaningful contribution from sources located on the Southern Ute Indian Reservation

to elevated ozone concentrations measured at New Mexico’s Navajo Lake monitor. The modeling and the analyses of the nine factor s support the Tribe’s recommendation that the

1 The nine factors analyzed by the Trib e are the factors listed in EPA’s guida nce but the Tribe’s analysis of the factors is not presented in the same order as the factors are listed in EPA’s guidance.2 Reservation should be designated attainment/unc lassifiable. In summary, burdening Reservation development with nonattainment requirements in circumstances where (1) Reservation monitors show attainment, (2) source appo rtionment shows the contribution by Reservation sources to a measured exceedance at New Mexico’s Navajo La ke monitor is not meaningful, (3) prevailing

winds blow from the west and southwest onto th e Reservation, and (4) th e Southern Ute Indian

Tribe/State of Colorado Environmental Commis sion and the Tribe already are aggressively acting to control emissions, w ould not likely result in ozone reductions in northwest New Mexico and would impose a disproportionate an d unfair burden on the Trib e to attempt to help

northwest New Mexico achieve attainme nt with the 2008 revised ozone NAAQS.3 II. Nine-Factor Analysis.

Factor 1 (Air Quality Data)

A. Monitoring Data Show Attainment for the Reservation.

The most recent years of quality-assured, cer tified air quality data collected from the two ozone monitors located on the Reservation, in cluding three consecutive years for the Ute 3 monitor, each sited and operated in accordance with applicable federal requirements, show compliance with the 2008 revised ozone NAAQS. The data shown in Table 1 and Figure 1 demonstrate attaining ozone leve ls well below the revised NAAQS.

Table 1. Southern Ute Indian Reservation Ozone Monitoring Data Summary.

4 th Maximum 8-Hour Ozone Values and 3-Year Averages

Site Name AQS # Year 3-Year Average

2005-07

(ppm) 3-Year Average

2006-08*

(ppm) 2005 (ppm) 2006 (ppm) 2007 (ppm) 2008 (ppm)

Ute 1- Ignacio 08-067-

7001 (Void) (Void) (Void) 0.067 n/a n/a

Ute 3- Hwy.

550/Bondad 08-067-

7003 0.066 0.063 0.071 0.067 0.066 0.067

*Note: Data are through October 20084 Figure 1. Ute 3 2006 – 2008 Ozone Monitoring Data.

Daily Maximum of the 4th Highest 8-hour Ozone Average at Ute 3 Site (2006-2008)

0.060 0.065 0.070 0.075 0.080

Ute 3 BondadConcentration (ppb)

2006-2008 Design Value Ozone NAA Q S = 0.075 pp b5 The location of the two ozone monitors on the Reservation, as well as the ozone monitors in surrounding areas, are shown on Figure 2.

Figure 2. Ozone Monitor Locations in the Four Corners Region.

The Tribe is aware that the monitoring data from New Mexico’s Navajo Lake monitor indicates that San Juan County, New Mexico, is not attaining the revised ozone NAAQS of 0.075 ppm. As shown in Figure 2, New Mexi co’s Navajo Lake monitor is located approximately 13 miles south of the southern bou ndary of the Reservati on. Emissions from Reservation-based sources, however, do not meaningf ully contribute to oz one concentrations in

northwest New Mexico and for that reason and the additional reasons discussed below, the Reservation should not be included in any nona ttainment area that may be designated for

northwest New Mexico. 2

2 The presumptive boundary for a nonattainment area based on the Navajo Lake monitor encompasses San Juan County, New Mexico, but does not include the S outhern Ute Indian Reservation, because they are in separate Core Based Statistical Areas. The EPA’s ozone area designations guidance provides that the Core Based Statistical Area (CBSA) or Combined Statistical Area (CSA) should serve as the starting point or presumptive boundary for any nonattainment designa tion. Where a violating monitor is not located in a CBSA or CSA, EPA recommends that the boundary of the county containing the monitor serve as the presumptive boundary for the nonattainment area. In this case, the Navajo Lake monitor is located at Navajo Lake State Park, which is located in San Juan County, New Mexico. Farmington, New Mexico, is in a CBSA that encompasses San Juan County and is designated as a metr opolitan statisti cal area. Durango, Colorado, is in a CBSA that encompasses La Plata County and the Reservation and is designated as a micropolitan statisti cal area. Neither statis tical area is included in a combined statistic al area, or CSA. The presumptive nonatt ainment boundary for the Navajo Lake monitor, th erefore, does not include the Reservation.6 Factor 2 (Meteorology)

A. Photochemical Source Apportionment Mode ling Shows that the Contribution of

Reservation Sources to Ozone Formation in Northwest New Mexico is Not Meaningful.

In evaluating if sources within an area shoul d be included in a near by nonattainment area, it is important to identify meaningful source culpab ility or source attributi on from that area to elevated ozone concentrations in the nearby nonattainment area. The most quantitative method for making that determination is to ut ilize source apportionment modeling within a photochemical grid model that has undergone an accuracy evaluation using actual ozone monitoring data. That kind of work is ongoing as part of the modeling analysis being done by

ENVIRON for the Four Corners Air Quality Group using the CAMx model.

An approach using ENVIRON’s CAMx model provides a more realistic quantitative representation of source contribu tions than using the NOAA HYSPLIT back trajectory model. The use of a photochemical grid model in conj unction with fine scale (4 kilometer) MM5 meteorological modeling provides a complete, accu rate picture of emission transport in the region within the mixed layer and provides a quantitative estimate of potential ozone

contributions that includes non-line ar chemistry of ozone formation. As part of the Four Corners analysis, the accuracy of the CAMx model was evaluated and found to be within EPA criteria. Thus, such a modeling analysis provides a comple te picture of Reservatio n source contributions

related to elevated ozone concentrations at New Mexico’s Navajo Lake monitor.

In contrast, the HYSPLIT model only provides an estimated flow at one or several layers in the atmosphere and possibly identifies what may be upwind regions from the Navajo Lake

monitor. Unlike the CAMx model, the HYSPLIT model provides no indication of pollutant concentrations. In addition, in complex terrai n such as the terrain where the Navajo Lake monitor is located, there is uncer tainty regarding the accuracy of the wind fields in HYSPLIT. In the EPA’s HYSPLIT analysis of the Navajo La ke monitor, there was no indication of the meteorological information that was used in the an alysis. One critical issue is the size of the grids used to estimate meteorologi cal conditions. In a recent analys is regarding the accuracy of meteorological modeled wind fields (as used by HYSPLIT) in Wyoming, it was found that wind

fields modeled with either a 36 kilometer grid or a 12 kilometer grid could not resolve the observed terrain influences in meteorological da ta caused by the Wind River Mountains. It was further found that a 4 kilometer grid was necessa ry in order to obtain an acceptable comparison between meteorological da ta and modeled wind fields 3

.

Thus the CAMx model results provide a more accurate estimate of the contribution from

Reservation sources to the elevated ozone meas urements at the Navajo Lake monitor than qualitative HYSPLIT modeling.

3 D.N. Blewitt, 2008, “Evaluation of the Accuracy of MM5/CALMET Generated Wind Fields in Southwestern Wyoming” Presented at EPA Modeling Conference October 2008.7 In this case, the Tribe has had an extensiv e air quality impact assessment performed by Air Quality Resource Management and ENVIRON using ENVIRON’s CAMx model for the Four Corners region. 4 ENVIRON’s CAMx model accuracy was evaluated for 2005 emissions and meteorology and future year source apportionment modeling was conducted for estimated 2018

emissions. 5 Because the 2018 modeling used 2005 emissions for Reservation emissions, the

modeled contributions from Rese rvation sources represent actual 2005 contributions. Figures 3 through 8 provide monthly estimates of hourly time series for 2005 predicted ozone concentrations at the Navajo Lake monitor for the months of April thr ough October and present the contribution from various source groups to total ozone formation at the Navajo Lake

monitor. 6 The source groups include boundary cond itions (BC) which reflect the amount of

ozone formed as a result of emissions outside th e Four Corners region, other sources in the Four Corners region (i.e., New Mexico oil and gas, elect ric generating utilities (EGU), mobile sources, area sources, etc.) and Reservation sources.

Importantly, as shown in Figures 3 through 8, ENVIRON’s modeling for ozone

evidences that:

• On many of the days with predicted elevated ozone concentrations at the Navajo Lake monitor, a contribution from Re servation sources does not exist;

• On days when there are contributions from Reservation sources, the contribution is not meaningful;

• A large amount of ozone in northwest New Me xico is the result of ozone transported from outside the Four Corners region; and

• New Mexico sources are responsible for the va st majority of ozone in the region above that which is transporte d from outside the region.

4 This analysis was complementary to the Four Corners air quality analysis performed for the Four Corners Air Quality Task Force and used the same modeling procedures, emission data, meteorological data and air quality data.

5 The Four Corners modeling analysis extrapolated the 2005 inventory to estimate 2018 emissions. This extrapolation was done using BLM’s Northern San Juan Environmental Impact Statement and Farmington Resource Management Plan analyses based on information contained in the Record of Decision and economic growth factors.

6 Because these figures represent 1-hour average concentrations and not 8-hour concentrations, these figures cannot be used to test compliance with the 8-hour ozone standard.8Figure 3. Hourly Time Series forNavajo Lake Monitor for April 2005.010203040506070804/ 1 4/ 2 4/ 3 4/ 4 4/ 5 4/ 6 4/ 7 4/ 8 4/ 9 4/10 4/11 4/12 4/13 4/14 4/15 4/16 4/17 4/18 4/19 4/20 4/21 4/22 4/23 4/24 4/25 4/26 4/27 4/28 4/29 4/30

Ozone Concentration (ppb)Initial ConditionsBoundary ConditionsReservation SourcesOther Sources in the 4 Corners RegionNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model9Figure 4. Hourly Time Series for Navajo Lake Monitor for May 2005.01020304050607080905/ 1 5/ 2 5/ 3 5/ 4 5/ 5 5/ 6 5/ 7 5/ 8 5/ 9 5/10 5/11 5/12 5/13 5/14 5/15 5/16 5/17 5/18 5/19 5/20 5/21 5/22 5/23 5/24 5/25 5/26 5/27 5/28 5/29 5/30 5/31

Ozone Concentrations (ppb)Initial ConditionsBoundary ConditionsReservation SourcesOther Sources in the 4 Corners RegionNote: 1) This information is notcomparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations thatwere used to start the CAMx model10Figure 5. Hourly Time Series for Navajo Lake Monitor for June 2005.01020304050607080906/ 1 6/ 2 6/ 3 6/ 4 6/ 5 6/ 6 6/ 7 6/ 8 6/ 9 6/10 6/11 6/12 6/13 6/14 6/15 6/16 6/17 6/18 6/19 6/20 6/21 6/22 6/23 6/24 6/25 6/26 6/27 6/28 6/29 6/30

Ozone Concentration (ppb)Initial ConditionsBoundary ConditionsReservation SourcesOther Sources in the 4 Corners RegionNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model11Figure 6. Hourly Time Series for Navajo Lake Monitor for July 2005.01020304050607080907/ 1 7/ 2 7/ 3 7/ 4 7/ 5 7/ 6 7/ 7 7/ 8 7/ 9 7/107/11 7/127/13 7/147/15 7/167/177/18 7/197/20 7/217/22 7/237/247/25 7/267/27 7/287/29 7/307/31

Ozone Concentration (ppb)Initial ConcentrationBoundary ConditionsReservation SourcesOther Sources in the 4 Corners RegionNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model12Figure 7. Hourly Time Series forNavajo Lake Monitor for August 2005.01020304050607080908/ 1 8/ 2 8/ 3 8/ 4 8/ 5 8/ 6 8/ 7 8/ 8 8/ 9 8/10 8/11 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 8/25 8/26 8/27 8/28 8/29 8/30 8/31

Ozone Concentrations (ppb)Initial ConditionsBoundary ConditionsReservation SourcesOther Sources in the 4 Corners RegionNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model13Figure 8. Hourly Time Series for Navajo Lake Monitorfor September 2005.01020304050607080909/ 1 9/ 2 9/ 3 9/ 4 9/ 5 9/ 6 9/ 7 9/ 8 9/ 9 9/10 9/11 9/12 9/13 9/14 9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 9/25 9/26 9/27 9/28 9/29 9/30

Ozone Concentratins (ppb)Initial ConditionsBoundary ConditionsReservation StandardsOther Reservation SourcesNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model14Figure 9. Hourly Time Series forNavajo Lake Monitor for October 2005.010203040506070809010/ 110/ 210/ 310/ 410/ 510/ 610/ 710/ 810/ 910/1010/1110/1210/1310/1410/1510/1610/1710/1810/1910/2010/2110/2210/2310/2410/2510/2610/2710/2810/2910/3010/31

Ozone Concentration (ppb)Initial ConditionsBoundary ConditionsReservation SourcesOther Sources in the 4 Corners AreaNote: 1) This information is not comparable to the 75 ppb 8-hour standard2) Initial conditions are the concentrations that were usedto start the CAMx model15 Table 2 quantifies the predicted hourly contributions from sources on the Reservation to predicted peak ozone at New Mexico’s Navajo Lake monitor. This table presents the number of hours when total predicted concentrations were above 60, 65, 70, and 75 ppb, as well as the contribution from s ources on the Reservation. As indicated in this table, the contribution, on average, from Reservation sources during periods of

elevated concentrations at New Mexico’s Nava jo Lake monitor is so small as to be not meaningful.

Table 2. Average Predicted Hourly O 3 (ppb) for all Hours Above Indicated Threshold at the

N

ava j

o Lake Monitor for 2005.

O 3 Concentrations

Greater than No. Hrs Average

Total Impacts Sources on

the
Reservation Other Sources

in the Four Corners Region Boundary
Conditions

60 472 68.4 0.9 28.8 38.7

65 295 71.9 1.0 32.5 38.3

70 167 75.4 1.2 36.0 38.2

75 86 78.2 1.2 39.7 37.3

N

ote: Boundar y Conditions indicate the amount o f

ozone f ormed as a result o f

sources outside the Four Corners region.16 Further analyses were conducted to evaluate whether, and if so, by how much, Reservation sources were contributing to a predicted exceedance of the 75 ppb 8-hour ozone standard at New Mexico’s Navajo Lake monitor. This was done by identifying all predicted hourly concentrations that had a total hourly ozone concentration in excess of 70 ppb and when the corresponding Reservation contributions were in excess of 1 ppb. Table 3 summarizes these modeling results and

indicates that Reservation sources are not res ponsible for any exceedances of the 8-hour ozone

standard and have a contribution to the overall model predicted concentr ations that is not meaningful.

Table 3. Total 8-Hour Ozone Predictions an d Corresponding SUIT Contributions for High Impact Days for 2005.

Rank Date Total (ppb) Reservation Sources (ppb) Percent

Contribution of

Reservation

Sources to Total Other

Sources in

the 4

Corners Region (ppb) Percent Contribution

of Other

Four Corners Sources

to Total

1 13-Jul 77.3 1.4 1.8 75.9 98.2

2 1-Aug 75.7 2.6 3.4 73.2 96.6

3 31-Jul 74.7 1 1.3 73.8 98.7

4 22-Jul 74.4 1.1 1.5 73.3 98.5

5 16-Jul 73.4 1.2 1.7 72.2 98.3

6 20-May 72.8 0.8 1.1 72 98.9

7 24-Jun 72.3 0.7 1 71.5 99.0

8 20-Jun 71.9 0.5 0.7 71.4 99.3

9 1-Jul 71.7 0.7 1 70.9 99.0

10 12-Jul 71.4 0.9 1.2 70.5 98.8

11 4-Jul 71.1 0.6 0.9 70.5 99.1

12 19-Jun 70.9 0.6 0.8 70.3 99.2

13 7-Jul 70.4 0.2 0.3 70.2 99.7

14 30-Jul 69.9 0.9 1.2 69 98.8

15 8-Sep 69.3 0.1 0.2 69.2 99.8

16 30-Jun 68.9 0.8 1.1 68.2 98.9

17 25-May 67.6 1.1 1.6 66.5 98.4

18 6-Sep 66.9 2.1 3.1 64.8 96.9

19 22-May 66.8 0.9 1.4 65.8 98.6

20 20-Jul 65.9 3.2 4.8 62.8 95.2

21 22-Apr 65.7 1 1.6 64.7 98.4

22 7-Sep 64 0.7 1.1 63.3 98.9

23 11-Jul 63.3 1.7 2.7 61.6 97.3

24 23-Aug 62.1 0.9 1.5 61.2 98.5

25 5-Sep 61.1 1.6 2.5 59.5 97.5

Average 69.6 1.1 1.6 68.5 98.4

N ote: Regulatory compliance is based on 4th highest concentration17 B. Wind Roses Show That Prevailing Winds Over the San Juan Basin Blow

from the West and Southwest.

The Southern Ute Indian Reservation, lo cated in southwestern Colorado, includes a substantial portion of the northern San Juan Basin. The Reservation remains generally semi-arid throughout the year cons istent with its location in th e arid/semi-arid continental Great Basin. Abundant sunshine and larg e diurnal temperature ranges occur in the region, largely as a result of the significant di stance from major oceans. Temperature and precipitation data from Ignacio, Colorado, are cons idered to be representative of climatic conditions within the Reservation. However, because elevation, slope and aspect affect precipitation and temperatures, the complex te rrain of La Plata County, Colorado, creates considerable climatic variability. The Reservation can be classified into six climatic

zones:

• Zone 1 - semi-desert grasslands at elevations below 6,000 feet; average annual precipitation less than 12 inches;

• Zone 2 - sagebrush savanna at elevations from 6,000 to 6,300 feet; average annual precipitation 12 to 13 inches;

• Zone 3 - piñon-juniper woodland at el evations from 6,0 00 to 7,200 feet; average annual precipitation 13 to 17 inches;

• Zone 4 - piñon-juniper/mountain browse at elevations from 6,100 to 8,400 feet; average annual precip itation 14 to 20 inches;

• Zone 5 - ponderosa pine at eleva tions from 6,500 to 8,800 feet; average precipitation 16 to 23 inches; and

• Zone 6 - fir-spruce/aspen at eleva tions from 6,600 to 9,000 feet; average precipitation 18 to 27 inches.

Annual precipitation measurements at Ignacio during the period from 1961 through 1990 averaged 14.4 inch es. From 1993 through 1996, precipitation was well distributed throughout th e year, with the months from April to June receiving the lowest average amounts (0.5 to 0.9 inches) and A ugust the highest levels (1.7 inches). Maximum precipitation occurring in the region in late summer and early fall is the result of moisture transport from the Gulf of Mexico under the western extension of the Bermuda High. 7 Much of this precipitation derives from afternoon convective thunderstorms that occur during the late su mmer “monsoon” season. Snow is another dominant form of precipitation on the Rese rvation, though more snowfall is generally seen in the higher elevations just north of the Reservation. During the winter season, the Reservation records an average of ro ughly 3 to 4 inches of precipitation.

December and January are the coldest m onths, with average lows of about 10 degrees Fahrenheit (°F) and highs of about 40°F. The wa rmest months are July and August with average minimum and maxi mum temperatures of 50°F and 85°F, respectively. Based on 30-year climate data (National Oceanic and Atmospheric

7 Tesche, T. W. and Dennis E. McNally, Air Quality Modeling Analysis for the San Juan County Early Action Compact: Episode Selection and Conceptual Model. June 17, 2003.18 Administration 1992), the norm mi nimum temperature (about 6°F) occurs in January and the normal maximum temperature (88°F) occurs in July.

Figures 10 through 18 are wind rose figures created using data gathered by the meteorological monitoring stations in the Four Corners region that depict the frequency, direction, and force of the winds that travel across the Rese rvation. The di stribution of

wind values are shown on each wind rose map. Note that the directions associated with any bar in these figures are the di rection from which the wind blows. 8 It should be noted

that all of these data were coll ected at a ten meter elevation.

Seasonal and daytime/nighttime wind roses display the predominant light winds crossing the Reservation blowi ng from the northeast with th e stronger less frequent winds gusting from the west (Figures 10 through 18) . During the summer daytime period when ozone concentration values are expected at their highest, the wi nd roses show more frequent west and southwest winds at the San Juan Substa tion, Bloomfield, and Navajo Lake sites in northern New Mexico (Figure 15). The Ute 1 and Ute 3 sites also illustrate similar characteristics of high frequency wi nds blowing from the west and southwest during the same time period. Overall, the wi nd rose models show that the winds over the San Juan Basin are westerly to southw esterly throughout much of the year.

8 Preprocessed meteorological data used to produce wind roses for each of the monitoring sites were obtained from the State of New Mexico Environment Department website, Air Resource Specialists, Inc., and EPA’s Air Quality Subsystem (AQS) database. New Mexico meteorological monitoring wind rose figures were for the Bloomfield, Substation, and Navajo Lake sites. Data from the Ute 1, Ute 3, Mesa Verde National Park, and Shamrock sites were used to produce the Colorado wind roses.19 Figure 10. 2008 Annual Wind Roses in the Four Corners Area.

Figure 11. 2008 Annual Daytime Wind Roses (6am – 6pm).20 Figure 12. 2008 Annual Nighttime Wind Roses (6pm – 6am).

Figure 13. 2008 Spring Wind Roses (March – May).21 Figure 14. 2008 Summer Wind Roses (June – August).

Figure 15. 2008 Summer Daytime Wind Rose s (June – August from 6am – 6pm).22 Figure 16. 2008 Summer Nighttime Wind Rose s (June – August from 6pm – 6am).

Figure 17. 2008 Autumn Wind Roses (September – November).23 Figure 18. 2008 Winter Wind Ro ses (December – February).24 Factor 3 (Emissions Data)

An evaluation of emissions data for the Re servation demonstrates the following: (1) based on a comparison of emission inventories fo r different areas within the Four Corners region, the contribution by sources located on the Reservation to el evated ozone concentrations in New Mexico is minimal, and (2) NOx emissi ons from large engine sources located on the Reservation already are with in the recently promulgated NSPS regulatory requirements.

A. Ozone Precursor Emissions from Reservatio n Sources are only a Small Portion of Ozone Precursor Emissions in the Four Corners Region.

Table 4 demonstrates that the Reservation sources are only a sma ll portion of the NOx emissions for the Four Corners region (2 percen t or 4,694 tons per year of a total of 221,865 tons per year) and an insign ificant amount of the VOC emissions (0.4 percent or 1,926 tons per year out of 431,649 tons per year). Compared to th e other areas in the Four Corners region,

contribution from the Reservation is much smaller than emissions from other areas in the region. For example, NOx emissions from the Rese rvation amount to 4,694 tons per year, while northwestern New Mexico’s sources alone, not including the Navajo Nation, emit 150,493 tons per year (approximately 32 times as much as the Reservation), and the Navajo Nation emits 45,323 tons per year (almost ten times as much as the Reservation). Comparisons of relative VOC emissions are similarly illustrative, with sources in northwestern New Mexico emitting 144 times as many tons per year of VOCs as the Rese rvation. Further, with respect to hydrocarbons,

the emissions from Reservation sources are primarily methane and ethane, which are not regulated VOC compounds by EPA because of low reactivity, and therefore have very little culpability in regional ozone formation. In othe r words, the Reservation is not a source of VOCs – one of the two primary precursors to ozone.

The data shown in Table 4 is a summary of the 2005 Four Corners regional emissions inventory that was developed as part of the Four Corners Task Force’s modeling project for the base case modeling and represent th e most accurate emission data in the region. It is important

to note that all stakeholders involved in th e modeling analysis approved this inventory.25Table 4. Summary of Regional NOx and VOC Emissions in the Four Corners Area4C - 4km Domain Emissions Summary (t/yr)2005 NOxJurisdictionAreaBiogenicsFugitiveDustOff-roadOn-roadRoadDustWindblownDustArea Oil & GasPoint Oil & GasElectricGeneratingUtilityNon-ElectricGeneratingUtilityGrand Total% Of totalArizona 97 211 0 2,407 4,661 0 0 13 0 0 0 7,388 3Colorado 302 659 0 1,910 3,757 0 0 921 2,548 0 535 10,632 5Navajo Nation 0 0 0 0 0 0 0 0 2,570 41,743 1,010 45,323 20New Mexico 16,036 833 0 11,219 30,182 0 0 37,848 19,834 30,925 3,615 150,493 68Pueblo of Laguna 0 0 0 0 0 0 0 0 0 0 1,551 1,551 1Pueblo of Santa Ana 0 0 0 0 0 0 0 0 0 0 209 209 0Southern Ute**0**0004,694004,6942Utah 42 130 0 181 741 0 0 51 352 0 78 1,575 1Ute Mountain Ute 0 0 0 0 0 0 0 0 0 0 0 0 0Grand Total 16,477 1,834 0 15,717 39,340 0 0 38,832 29,998 72,668 6,997 221,865 100Source: ENVIRON for Four Corners Modeling Group* Area, Biogenics, Off-road and On-road emissions for Southern Ute are included in the numbers shown for Colorado.264C - 4km Domain Emissions Summary (t/yr) (continued)2005 VOCJurisdictionAreaBiogenicsFugitiveDustOff-roadOn-roadRoadDustWindblownDustArea Oil & GasPoint Oil & GasElectricGeneratingUtilityNon-ElectricGeneratingUtilityGrand Total% of TotalArizona 2,204 29,202 0 728 3,314 0 0 37 0 0 0 35,484 8Colorado 3,632 84,822 0 4,884 2,616 0 0 891 1,257 0 348 98,450 23Navajo Nation 0 0 0 0 0 0 0 0 293 292 121 706 0New Mexico 26,675 108,515 0 5,690 17,079 0 0 109,480 7,857 7 1,849 277,152 64Pueblo of Laguna 0 0 0 0 0 0 0 0 0 0 11 11 0Pueblo of Santa Ana 0 0 0 0 0 0 0 0 0 0 49 49 0Southern Ute**0**0001,926**001,9260Utah 479 15,931 0 388 490 0 0 455 77 0 52 17,872 4Ute Mountain Ute 0 0 0 0 0 0 0 0 0 0 0 0 0Grand Total 32,989 238,471 0 11,690 23,499 0 0 110,862 11,410 299 2,429 431,649 100Source: ENVIRON for Four Corners Modeling Group* Area, Biogenics, Off-road and On-road emissions for Southern Ute are included in the numbers shown for Colorado.** VOC emissions from oil and gas operations are based on the production of coal bed methane which does not contain VOC compounds.27 As indicated in Figure 19, the contribution to NOx emissions in the Four Corners region by sources on the Reservation is only about 2 percent.

Figure 19. Relative Contribution to Total NOx Inventory

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As indicated in Figure 20, the contribution to VOC emissions in the Four Corners region by Reservation sources is less than 1 percent.

Figure 20. Relative contribution to Total VOC Inventory

0 10 20 30 40 50 60 70

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. . .%28 B. Emissions Data Show Large Engine So urces on the Reservation Already Have

Low NOx Emissions.

Table 5 presents a summary of the level of the distribution of emissions from data compiled for engines as part of a 2005 em ission inventory for the Reservation.

Table 5. Distribution of Reciprocating Internal Combustion Engines on the

Reservation in 2005 that Process CBM Gas.

Engine Size (hp) Number

of Engines Number

of Engines (percent) Percentage of Capacity Average

NOx

Emission

Factor(g/hphour) Total

NOx

Emissions (t/yr) Emissions (percent)

>500 170 53.0 92 1.5 2,982 71

<500 >100 76 23.7 6.1 7.7 724 17

<100 >25 73 22.7 1.8 12.2 510 12

<25 2 0.6 0.0 27 11 0.3

Total 321 100 4,227

As indicated by this analysis, the vast number of engines on the Reservation have capacities in excess of 500 horsepo wer and are controlled with non- selective catalytic reduction (NSCR) or are low emitting lean burn engines. 9 Table 5 shows that 71 percent of the emissions and 92 percent of the capacity are from engines larger than 500 horsepower. For this size engine, the average NOx emission factor is 1.5 g/hp-hour. Currently, therefore, the overwhelming majority of the large natural ga s fired compressor engines on the Reservation already meet or exceed the recently promul gated EPA New Source Performance Standard (NSPS) for reciprocating internal combustion engines (RICE). 73 Fed. Reg. 3568 (January 18, 2008)

.

For the small to medium size engines (i .e., engines below 500 hp, which account for approximately 29 percent of the emissions shown in Table 5), the Tribe intends to improve the controls on those engines and reduce their emi ssions through implementation of a minor source permitting program, which is in the final draft stage and which the Tribe expects will be implemented in late 2009 or early 2010. The minor source program will impose restrictions upon both new and existing sources. In addition, the Tribe intends to condition its consent to new well development on the inclusion of additional controls.

9 It is important to note that the inventory identified only one engine in this size class that was not controlled.29 Factor 4 (Level of Control of Emission Sources) – The Southern Ute Indian Tribe/State of Colorado Environmental Commission (Envir onmental Commission) and the Tribe are Taking Responsibility for the Control of Emission Sources on the Reservation.

A. Existing Regulatory Framework on the Reservation. EPA currently implements emission controls for major sources on the Reservation. New sources with a potential to emit (PTE) in excess of 250 tons per year are requir ed to obtain a PSD permit prior to construction. In addition, sources with PTE in excess of 100 tons per year are required to obtain a Title V operating permit. There currently is no federal minor source program for Indian country, so sources that do not require a PSD pre-construction permit or a Title V operating permit (i.e., minor sources) are unpermitted for the time being. 10

B. Existing Sources on the Reservation Already are Well-Controlled.

The Four Corners Task Force recently pub lished a report regarding mitigation options 11

, which provided a detailed analysis of emissi on reduction options for oil and gas engine mitigation. 12 The majority of the controls identified by the Task Force are already in use on the

Reservation. The others were determined to be ineffective or infeasible. The Four Corners report examined:

• Electrification of natural ga s fired compressor engines;

• Lean burn technology;

• Non selective catalyt ic reduction (NSCR);

• Selective catalytic reduction (SCR);

• Oxidation catalyst

Table 6 demonstrates how the mitigation measures have been applied on compressor engines on the Reservation, and i ndicates whether those measures are feasible and effective.

10 On August 21, 2006, EPA issued a notice of propos ed rulemaking entitled “Review of New Sources and Modifications in Indian Country.” 71 Fed. Reg. 48,696 (2006) . In that notice, EPA proposed to promulgate a Federal Implementation Plan (“FIP”) covering certain minor emission sources in “Indian country” nationwide. To date, however, EPA has not finalized the proposed FIP.

11 Mitigation is defined as additional emission controls beyond NSPS.

12 Four Corners Air Quality Task For ce Report of Mitigation Options, 200730 Table 6. Summary of Conclusions Regarding Additional Controls on Natural Gas Fired Engines for Oil and Gas

Mitigation Option Comments Electrification of natural gas fired compressor engines Based on information and belief, a major operator on the Reservation (i.e., BP America Inc.) plans for all of its new engines associated with ongoing infill development

on the Reservation to be electrically operated and, over the next two years, plans to replace approximately 100 existing engines with electrically operated engi nes. The effect of this conversion to electrically operated engines will be to further reduce emissions

from Reservation sources. Lean burn technology Already widely in use Non selective catalytic reduction (NSCR); Already widely in use

Selective catalytic reduction (SCR) Not Feasible—Not commercially available for remote oil and gas operations Oxidation catalyst Already widely in use

As indicated in Table 6, there is very little opportunity to retrof it existing engines with additional

reliable and cost effective controls that will further reduce emissions from natural gas fired engines on the Reservation below NSPS levels. At the present time, proven technology does not

exist to reduce emissions below th e federally mandated limits. Thus, existing sources within the Reservation already are well-controlled.

Notwithstanding the conclusion in Table 6 rega rding electrification, it is important to note that, based on information and belief, a majo r operator on the Reservation (i.e., BP America Inc.) plans for all of its new engines asso ciated with ongoing infill development on the Reservation to be electrically operated a nd, over the next two years, plans to replace approximately 100 existing engines with electrically operated engi nes. The effect of this conversion to electrically operate d engines will be to further re duce emissions from Reservation

sources.

C. Tribal Efforts to Assume Regulato ry Responsibility Will Result in Better

Control of Sources and Decreased Emissions.

The Tribe is aggressively engaged, in c ooperation with the State of Colorado, in developing a Reservation air pr ogram to regulate a ll air pollution sour ces located on the

Reservation and to maintain the attainment/uncla ssifiable status of the Reservation area. In 1999, the Tribe and State entered into an interg overnmental agreement concerning air quality

control on the Reservation. The purpose of the agreement is to establish a single air quality program applicable to all lands within the ex terior boundaries of the Reservation. A joint31 Tribal/State Environmental Commission was esta blished with responsibi lity for selecting the Clean Air Act programs and other air programs that will be adopted for the Reservation. Under the agreement, the day-to-day administration of the programs is the responsibility of the Tribe.

In 2004, Congress provided specific statutory au thority for the Tribe to regulate all air

resources within the exterior boundaries of the Reservation. Southern Ute and Colorado Intergovernmental Agreemen t Implementation Act of 2004 , Act of October 18, 2004, Pub. L. No. 108-336, 118 Stat. 1354-56 (Public Law 108-336). Public Law 108-336 accomplished several important objectives. First, Public Law 108- 336 authorizes the Environmental Protection Agency to treat the Tribe as a state under secti on 301(d) of the Clean Ai r Act, and allows the Tribe to accept delegation of EPA’s authority un der the Clean Air Act in the same manner as states for purposes of administ ering air quality programs. Sec. 4(a)(1) . Second, Public Law 108- 336 provides that the scope of the Tribe’s delegate d authority extends to a ll air resources within

the exterior boundaries of the Reservati on, including those located on fee land. Sec. 4(a)(2) . No distinction is made among the various categories of on-Reservation land. Once the delegation is made, therefore, the Tribe is au thorized to regulate sources of air pollution located anywhere

within the exterior boundaries of the Rese rvation. Third, Public Law 108-336 provides jurisdiction for enforcement of the Tribe’s delega ted powers in the United States District Court for the District of Colorado and provides for j udicial review in the United States Court of Appeals for the Tenth Circuit. Secs. 5(a) and 6

, Public Law 108-336

.

On January 20, 2009, the Tribe submitted its Application for Treatment as a State Pursuant to Section 301(d) of the Clean Air Ac t and Section 4(a) of the Southern Ute and Colorado Intergovernmental Agreement Implementa tion Act of 2004 for the Purpose of Approval of the Southern Ute Indian Tribe’s Part 70 Operating Permit Program (TAS Application) and Application for Approval of the Southern Ute Indian Tribe’s 40 CFR Part 70 Operating Permit Program (Part 70 Program Application). Upon appr oval of the TAS Application and Part 70 Program Application by EPA, the Tribe will become the first Indian tribe in the nation to receive a delegation of authority to administer a Pa rt 70 operating permit program. These efforts exemplify the Tribe’s commitment to emissions c ontrol and clean air. Because the program will be administered locally, and because the Tribe wi ll have several staff members devoted solely to regulation and inspection of sour ces located on the Reservation, th e Tribe expects that emissions

from sources located on the Reservation will be more effectively controlled than they are currently. 13

Further, the Tribe plans to seek a delegation of authority from EPA, in accordance with the process established by its agreement with the State of Colo rado, to incorporate as part of the Reservation air program certain standards of pe rformance established by EPA pursuant to section 111 of the Clean Air Act (regulating criteria polluta nt emissions from specific categories of new sources) (NSPS) and certain National Emissi on Standards for Hazardous Air Pollutants established by EPA pursuant to section 112 of the Clean Air Act (NESHAP) (regulating hazardous air pollutant emissions from specific categories of new and existing sources). The incorporation will enable the Tribe and the Environmental Commission to exercise administrative authority with respect to the incorp orated regulations. With that authority will

13 There are five staff members employed as part of the Tribe’s Air Quality Program, which is a ratio of approximately 1 staff member to every 8 ma jor sources on the Reservation.32 come the authority to set and im plement controls on major sources that are more stringent than those that are imposed by the federal government.

Recognizing the importance of regulating minor sources, the Tribe cu rrently is finalizing a minor source permitting program to recommend to the Environmental Commission. The Tribe intends to recommend the program in spring 2009 with the expectation th at the Environmental Commission will adopt the program for implemen tation in late 2009 or early 2010. The adoption of a minor source permitting program is the sec ond priority of the Environmental Commission

and Tribe under their Long-Term Plan for Reservation Air Program , after the development of the Part 70 operating permit program.

The minor source permitting program will mirro r certain aspects of the proposed federal minor source NSR program ( 71 Fed. Reg. 48,696 (2006) ), yet will be tailored towards the specific regulatory needs of the Reservation, and w ill, in some respects, be more stringent than the proposed federal program. The purpose of the program is to establish a permitting program for existing, new, and modified minor sources of air pollution and for minor modifications at major stationary sources located within the ex terior boundaries of the Reservation. The draft program includes proposed minor source thresholds so that only minor sources with a potential to emit (PTE) equal to or higher than those thres holds (and less than the th resholds necessary for regulation as a major source) will be subject to the program. 14 By regulating existing minor sources on the Reservation, the Tr ibe’s proposed program goes a st ep further than the proposed federal minor source NSR program. Sources subject to the progr am (including existing, new, and modified sources) will be required to appl y control technology and be subject to emission limits as determined by the Tribe on a case-by- case basis or based on an application of presumptive best available cont rol technology that may be establ ished by the Tribe for various categories of similar sources with similar contro l technologies and capabili ties. Additionally, the Tribe’s draft program will allow otherwise majo r stationary sources on the Reservation to voluntarily accept emission limitations on their PTE to become “synthetic minor sources.” Such synthetic minor sources will include sources that emit hazardous air pollutants.

The draft program also sets forth the criter ia and procedures that the Tribe will use to administer the program. In accordance with the IGA and Public Law No. 108-336, the Tribe and

Environmental Commission will enforce civil co mpliance with the program. Actions taken by the Tribe in the administration of the program will be subject to administrative review by the

Environmental Commission in accordance with the procedures contained in the program regulations. A copy of the minor source progra m will be provided to EPA-Region 8 for review and comment as part of the Environmental Co mmission’s public review and comment process once the Tribe’s recommended program beco mes an Environmental Commission proposed program. A copy of the Tribe’s draft program is available now, however, and will be provided to EPA upon request.

The development of the minor source permitti ng program and, specifically, the plan to make not only new and modified sources but also existing minor sources subject to emission limits and control technology requirements set by the Tribe under the program, demonstrates the

14 The thresholds included in the Tribe’s draft minor source program are the same as the thresholds contained in the proposed federal program.33 Tribe’s intention to aggressively control NOx emissions from the estimated 300 to 400 minor

sources located on the Reservation. This program, coupled with (1) the Tribe’s and

Environmental Commission’s efforts to reduce NOx emissions from the Reservation’s 40+ major sources (in part through aggressi ve administration of the Part 70 operating permit program once it is delegated by EPA to the Tribe (e.g., more frequent inspections) and through the possible adoption of more stringent s ubstantive requirements (e.g., NSPS , NESHAPS, and MACT)), and (2) the tribal-imposed conditions on new inf ill well development on the Reservation, should

ensure maintenance of the attainment/unclass ifiable status of the Reservation for the 2008

revised ozone standards.

In sum, the programs planned for implemen tation on the Reservation, particularly the minor source program, will be sufficient for the Tribe and Environmental Commission to maintain and prevent deterioration of the Reservation’s existing good air quality.34 Factor 5 (Growth Rates and Patterns)

A. Existing Development.

Emissions associated with mineral extraction activities are the prin cipal source of air pollution on the Reservation, where rural popula tion densities and agricultural land uses predominate. Development of its coalbed me thane and natural gas resources has been and

continues to be the economic lifeb lood of the Tribe. Overall, th e wells on the Reservation are on the declining end of the production curve. As noted above, the ozone monitors on the Reservation show attainment, and a source appo rtionment study shows that Reservation sources do not contribute meaningfully to ozone exceedances that have been measured at New Mexico’s Navajo Lake monitor.

B. 80-Acre Infill Development.

With the Tribe’s support, well density based on 80 acres rather than 160 acres on lands

within the exterior boundaries of the Reservation already has b een approved by the Colorado Oil and Gas Conservation Commission and development of infill wells on non-Indian fee lands has begun. Development of infill wells on Tribal land is needed to ensure that the gas reserves that are held in trust by the United States for the benefit of the Tribe are efficiently extracted in a manner that protects against drainage and is protective of correlative rights.

For the infill development on the Reservat ion, all new natural gas-fired compressor engines (i.e., the largest NOx emi ssion sources associated with the development) will be required to meet the new NSPS emission limits as a matter of federal law. In addition, in order to ensure

that Reservation mineral resource s are extracted in an environm entally compatible manner, the Tribal Council has required, as a condition of consenting to 80 -acre infill development, the presumptive utilization of the best available ai r emissions control technology for new compressor installation, as well as the presumptive upgrade of existing compressors to contemporary best available emissions control technology to the ma ximum extent feasible in a manner consistent with optimizing air quality on the Reservation.

Full infill development of Tribal lands within the Reservation would consist of as many

as 770 new coalbed methane 80-acre infill wells to be drilled from existing and new well sites on the Reservation over a 20-year period. 15 That development, however, will not increase overall emissions from Reservation sources. In fact, as demonstrated below, there will be a dramatic decline in NOx emissions from Reservation sources over the life of the development.

15 In comparison, according to a 20-y ear Reasonably Foreseeable Developm ent Scenario supporting a Resource Management Plan prepared by the Bureau of Land Management in 2001 for the BLM’s Farmington, New Mexico Field Office, there are approximately 12,461 new oil and gas wells that are expected to be completed from 2002- 2022 in the New Mexico portion of the San Juan Basin (i.e., San Juan County and western Rio Arriba County). That equates to approximately 623 new wells per year.35 C. A Nonattainment Designation Base d on Possible Future Development is Inappropriate Since NOx Emissions from Reservation Sources (and, Hence, Ozone Levels on the Reser vation) are Expected to Decrease Over

the Next 20 Years Notwithsta nding Infill Development.

Air Quality Resource Management and E NVIRON International Corporation have performed an extensive air quality impact analys is assessing the impact of this anticipated growth. The analysis conservatively assumes th at the requirements of the NSPS will be applied only to new compressor installation and assumes no upgrades to existing compressors. Figure 21 presents annual production estimates through 2027 with and without infill development on the Reservation and Figure 22 presents a summary of projected NOx emissions through 2027. As indicated by these figures, because of production decline, emissions of NOx (an ozone precursor) are projected to dramatically decrease. Furthe rmore, due to the additional upgrades to existing compressors required by the Tribe, this emissions decrease is anticipated to be accelerated.

While NOx emissions from the Reservation will decr ease even with infill development and even without the supplemental upgrades to existing compressors, the same probably cannot be said of ozone precursor emissions from northwest New Mexico, given that nearly 15 times the amount of new wells may be drilled in that area as comp ared to the Reservation, given that New Mexico state law bars the State from implementing regulati ons that are more stringent than federal NSPS regulations, and given the possibl e construction of an additional coal-fired power plant in the

northwest New Mexico area.36 

## Figure 21. E s timated P roduc tion

Volume by Year

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E xis ting T otal T ribal Infill Fee Infill T otal (exis ting + infill)

P res s ure C hange

Note: Future year emissions were pr ojected using operating data from 2005.38 Factor 6 (Jurisdictional Boundaries)

A. Control of Emission Sources in a Regional Nonattainment Area Would be Spread Among Multiple Jurisdictions and (1) is Unnecessary, (2) Could Slow

the Tribe’s and Environmental Commi ssion’s Implementation of Air Pollution Control Measures, and (3) Wou ld Not Efficiently and Effectively Serve the Purpose of Improving Air Quality.

In 1984, Congress confirmed the exterior boundaries of the Southern Ute Indian Reservation, which contains approximatel y 710,000 acres of land in southwest Colorado. Because of the vagaries of federal Indian policy over the last 125 years, land within the

Reservation is owned in a checkerboard fashion by a number of different parties, meaning that

some of the land within the ex terior boundaries of the Reserv ation is owned by Indians and nonIndians in fee, while other land is owned by the Un ited States in trust. The United States holds approximately 300,000 surface acres in trust for th e Tribe. Additionally, the Tribe is the beneficial owner of minerals, in cluding oil, gas and coal, on more than half of the Reservation lands. As discussed, the Tribe and Envir onmental Commission have been recognized by Congress as being primarily responsible fo r air quality on the Reservation, and the Environmental Commission’s air pollution control programs will apply to all sources on the Reservation, regardless of whet her they are located on fee or trust land, and regardless of whether the sources are owned by I ndian or non-Indian entities.

Jurisdictional complications are amplified when considering all of the entities that can claim jurisdiction in the Four Co rners region, given that the regi on includes four states, three EPA regions, and a half-dozen Indian reservatio ns. Control of emissi on sources in the Four Corners region is spread among multiple jurisdic tions. On the Reservation, as noted above, regulatory authority currently is exercised by EPA but the En vironmental Commission has the authority to establish CAA and other air pollution cont rol programs for the Reservation. Once adopted by the Environmental Commission, the Trib e may (1) apply for a delegation of authority from EPA to administer the CAA programs, a nd (2) administer the non-CAA programs. For

land outside the exterior boundari es of the Reservation and within Colorado, the State of Colorado is the primary regulatory agency. With in northwest New Mexico, regulatory authority is split among two EPA regional offices (Region 6 for lands within New Mexico that are not within the Navajo Reservation and Region 9 for la nds within the Navajo Reservation); the State of New Mexico; and the Navajo Nation. A re gional nonattainment area would require close coordination among all of the entitie s with regulatory authority.

The inclusion of the Reservation in a nona ttainment area that spans all of those jurisdictions, however, is unnecessary given the substant ial efforts that the Tribe and Environmental Commission already are making to control emissions. As evidenced by the progress that the Tribe and the Environmental Comm ission have made with regard to air quality permitting and regulation on the Reservation, as we ll as the proactive stance they have already taken to address emissions, the Tribe and th e Environmental Commission will be the most

effective entities to facilitate air quality planning and implemen tation of control measures on the

Reservation to maintain the Reservation’s attain ment/unclassifiable status with the 2008 revised

ozone standard. If the Reservation were to be included in a nonattainment area, the efforts39 required to prepare and implement a plan for brin ging the area into attainment could hamper and delay the Tribe’s and Environmen tal Commission’s current efforts to control emissions, their progress in that regard, and their ability to efficiently regulate through development of the Reservation air program. In sum, further complic ating an already difficult jurisdictional situation by thrusting the Reservation into an interstate, intergovernment al, nonattainment area would not effectively and efficiently serve th e purpose of improving air quality.

B. The Reservation is Already a Se parate Air Quality Control Region.

The nine-factor analysis that will be us ed in making area designations for the 2008 revised ozone standard also was used by EPA in making area designations for the 2006 24-hour fine particle standard. In th e context of the area designations for the 2006 24-hour fine particle standard, EPA stated that in evaluating the ju risdictional boundary fact or, consideration should be given to existing boundaries a nd organizations that may facilita te air quality planning and the implementation of control measures to attain the standard. As explained below, the Reservation already has effectively been de signated as a separate AQCR vi a Congressional action and should

continue to be considered a separate AQCR for purposes of maintenance of an attainment/unclassifiable designation fo r the 2008 revised ozone standard.

First, by not being part of a region desi gnated by one of the first two means for designation under CAA section 107 (i.e., designated as an AQCR by Congress before December 31, 1970, pursuant to the Air Quality Act of 1967; or by EPA as part of an interstate or major intrastate area “necessary or a ppropriate” for the attainment and maintenance of the NAAQS), the Reservation became its own AQCR.

Second, the Reservation is r ecognized by Congress in the Southern Ute and Colorado Intergovernmental Agreemen t Implementation Act of 2004 as the geographic area within which

the Environmental Commission and the Tribe are primarily responsible for assuring air quality (by submitting an implementation plan which will specify the manner in which national primary and secondary ambient air quality standards will be achieved and maintained within each air quality control region in the Reserv ation area). The purpose of the Southern Ute and Colorado Intergovernmental Agreemen t Implementation Act of 2004 was to:

provide for the implementation and enforcement of air quality control programs under the Clean Air Act (42 U.S.C. 7401 et seq .) and other air quality programs developed in acco rdance with the Intergovernmental Agreement that provide for – (1) the regulation of air quality with in the exterior boundaries of the Southern Ute Indian Reservation; and

(2) the establishment of a Southern Ute Indian Tribe/State of Colorado

Environmental Commission.

Pub. L. No. 108-336, § 2(b), 118 Stat. 1354 (2004). This unique arrangement was created to specifically address and resolve a complicated juri sdictional issue between the Tribe and State of40 Colorado and, given adequate opportunity, will prove to be an effective means to regulate air quality on the Reservation.

Third, EPA has determined that the CAA opera tes as a delegation of federal jurisdiction to tribes to administer programs with respect to all air resources within the tribe’s reservation.

See 63 Fed. Reg. 7254 (1998). In other words, in the CAA amendments of 1990, Congress authorized tribes to act as primary air quality re gulators and recognized th eir reservations as the areas over which they are primarily re sponsible. CAA § 301; 42 U.S.C. § 7601(d).41 Factor 7 (Geography/Topography)

The Reservation is located in the northern portion of the San Juan Basin and the eastern

area of the Colorado Plateau in southwestern Colorado. The Colorado Plateau is a vast physiographic province extendi ng throughout western Colorado, northwestern New Mexico, most of northern Arizona, and southern and eastern Utah. Th is physiographic province is characterized by generally flat-lying sedimentar y deposits divided by faults and monoclines that form cliffs and individual plateaus. Steep-sid ed mesas and buttes cappe d by erosion-resistant rock layers are common.

The topography of the Reservation varies from moderately steep to steep mountains, canyons, and mesas in the north-central and sout h-central portions, to ro lling hills and gently sloping river valleys in the easte rn and western regions. Elevations range from about 6,000 to 9,000 feet.

Figure 23. Geography of the Southern Ute Indian Reservation.42 Factor 8 (Population Density and Degree of Urbanization)

Data from the U.S. Census Bureau demonstrat es that the Southern Ute Indian Reservation is sparsely populated, and the degr ee of urbanization is minimal. Only two small towns, Ignacio and Arboles, are located within the Reserv ation boundaries, and th e remainder of the Reservation’s population is scatte red throughout the portion of the Re servation that is comprised of unincorporated areas of Arc huleta and La Plata counties. Based on information provided on the website for the Colorado State Demography Office, the total population on the Reservation for 2007, including both Indians and non-Indians, is estimated to be approximately 16,128.

As shown in Table 7, the population estimate for the Reservation was calculated using the population estimates for the unincorporated portions of Archuleta and La Plata counties multiplied by the estimated percentage of those counties that are within the exterior boundaries

of the Reservation.

Table 7. Reservation Demography – Es timated Population on Reservation.

County / Town % of County/Town covered by

Reservation 2005 Population 2005 Total on

Reservation 2006 Population 2006 Total on

Reservation 2007 Population 2007 Total on

Reservation

Archuleta Unincorporated Area 29% 10,055 2,916 10,509 3,048 10,865 3,151

La Plata Unincorporated Area 39.6% 29,788 11,796 30,261 11,983 30,912 12,241

Ignacio 100% 755 755 741 741 736 736

La Plata Total 12,551 12,724 12,977

Source: http//www.dola.colorado.gov/dlg/demog/pop_munil_estimates.html

Table 8 shows that, based on the 2006 and 2007 population data, the average growth rate on the Reservation is 2.7% (i .e., (3.4 +2.0) ÷ 2 = 2.7%).

Table 8. Reservation Demography – Estimate d Population Growth on Reservation.

County 2005 Total

on Reservation 2006 Total

on Reservation 2007 Total

on Reservation Percent Change

2006 -2007

Archuleta Unincorporated 2,916 3,048 3,151 3.4%

La Plata Unincorporated and Ignacio 12,551 12,724 12,977 2.0%43 The total square miles of both Archuleta a nd La Plata counties and the estimated portion

of those counties that lie within the exterior boundaries of the Re servation are shown on Table 9.

Table 9. Estimated Total Square Miles on the Reservation.

County Total Square

Miles % County Covered by

Reservation Total Square

Miles on

Reservation

Archuleta 1,355 29.0% 393.0

La Plata 1,700 39.6% 673.2

Based on the population estimates shown in Table 7, the estimated population density

within the exterior boundaries of the Reservation is 27 people per square mile, which is well below the United States average populati on density of 80 people per square mile :

Table 10. Estimated Population Density on the Reservation.

County Total Square

Miles on

Reservation 2005
Persons Per Square Mile 2006
Persons Per Square Mile 2007
Persons Per Square Mile

Archuleta 391.5 7 8 8

La Plata 670.0 19 19 19

TOTAL on

Reservation 26 27 27

Even combined with the three counties in s outhwest Colorado, the Re servation population has not only a much smaller density than the United St ates average density, it also is much smaller than the population of northwest New Mexico, whic h is 75 percent higher than the population of

southwest Colorado.44 Factor 9 (Traffic and Commuting Patterns)

Traffic volume on the Reservation is relativel y low. Approximately 150 miles of state and major highway segments cross the Reserva tion. Table 9 shows da ily and annual vehicle miles travelled, as well as total emissions fr om vehicle travel on pa ved roads within the

Reservation for 2005.

Table 11. Emissions from Vehicle Travel on Paved Roads within the Reservation Boundaries
(tons) **

Paved Roads Length (mi) Daily VMT* Annual

VMT* VOC (tons) CO (tons) NOx (tons) PM 10 (tons)

Hwy 550 15.61 100,794 3.6789E+0 7 56.78 1,011.56 95.43 2.50

Hwy 140 15.658 31,860 1.1628E+0 7 17.95 319.74 30.16 0.79

Hwy 151 33.96 43,120 1.5738E+0 7 24.29 432.75 40.82 1.07

US Hwy 160 7.668 65,323 2.3843E +07 46.16 704.20 71.84 1.85

Hwy 172 24.449 102,151 3.72835+ 07 57.54 1,025.18 96.71 2.53

Other Hwys 52 66,026 2.4099E+07 46.66 711.78 72.61 1.87

Totals 149.40 409,274.00 1.4935E+0 7 289.21 3,862.95 450.08 11.58

** Southern Ute Indian Tribe Air Emissions Inventory Base Year 2005. * Vehicle miles traveled (VMT) data is based on inventory data from the Colorado Department of Transportation website.

According to the Southern Ute Indian Trib e Air Emissions Inventory Base Year 2002, there are approximately 3,700 miles of unpave d roads on the Reservation. Table 10

demonstrates the emissions from vehicle trav el on unpaved roads within the Reservation for

Base Year 2002.

Table 12. Emissions from Vehicle Travel on Unpaved Roads within the SUIT Reservation
Boundaries (tons) *

VOC (tons) CO (tons) NO
x (tons) PM 10 (tons) Unpaved Road Emissions 12.51 184.0 18.52 8,589 * Southern Ute Indian Tribe Air Emissions Inventory Base Year 2002.45 III. Other Factors.

A. EPA Must Consider Tribal Self-Determination in Making its Area Designation for the Reservation.

In the 1984 EPA Indian Policy, EPA committed th at, “in keeping with the federal trust responsibility,” it would “assure th at tribal concerns and interest s are considered whenever EPA’s actions and/or decisions may aff ect reservation environments.” The Tribe’s interest in pursuing expanded control over emissions on the Reserv ation and in proposing its 80-acre infill development project is linked to the strong federa l interests in promoting strong tribal economic development, self-sufficiency, and self-governance. In that regard, the Tribe is concerned that imposition of a nonattainment designation on the Reservation by EPA, and the corresponding nonattainment requirements, would constitute an infringement on the Tribe’s interests in territorial autonomy and could dama ge the long-term economic and soci al interests of the Tribe. The northern San Juan Basin is continuing to be developed and, as noted above, the Colorado Oil and Gas Commission already has ap proved 80-acre infill drilling on lands within the Reservation

boundaries. Prudent and environmen tally protective development of the mineral resources held in trust by the United States for the benefit of th e Tribe is an important economic development objective of the Tribe. In fact , such development is for the e xpress purpose of improving the economic and social well-being of the Tribe and its members. A portion of the revenues from development of the trust mineral estate are distri buted to tribal members and a portion is used by the Tribe to fund many important go vernmental functions and servic es such as the Tribe’s police department, court system, school, education progr ams, health care services, water treatment plants, and recreation programs. Accordingly, the Tribe expects that in keeping with its commitment given in the 1984 EPA Indian Policy, EPA will “give special c onsideration to Tribal interests” when considering a de signation for Reservation.

B. Environmental Justice Favors an Attain ment/Unclassifiable Designation for

the Reservation.

In 1994, the President issued Executive Order 12,898 on environmental justice in minority and low-income populations. Executive Order 12,898: Federal Actions to Address

Environmental Justice in Minor ity Populations and Low-Inco me Populations, 59 Fed. Reg. 7629 (1994)

. The purpose of the Order is to identify and address, as appropriate, disproportionately high and adverse human health and environmental e ffects of programs, polic ies, or activities on minority or low-income populations. The mandates of Executive Order 12,898 specifically apply to Native American programs. Id . at § 6-606, 59 Fed. Reg. 7629, 7632 (1994). On the Reservation, minority populations include Native Americans and Hispanics. Low-income groups on the Reservation may include low-income Indian s, Hispanics, and Caucasians. The Council on Environmental Quality has issued a guidance doc ument on compliance with the President’s order on environmental justice that is designed to engender greater tribal involvement. Council on Environmental Quality, Environmental Justic e: Guidance Under the National Environmental Policy Act 1, 9 (Dec. 10, 1997), < ceq.eh.doe.gov/nepa/regs/ej/justice.pdf> . This guidance document provides that the environmental justice c oncerns that federal agencies must address in their decision-making arise not only from imp acts on the natural and physical environment, but

also from related social and economic impacts on the affected populations.46 The Tribe is concerned that a nonattainment designation of the Reservation by EPA for the 2008 revised ozone NAAQS woul d have a disproportionate negative impact on the Tribe and

its members and would be unfair to the Tribe from a social and economic perspective. As noted above, comparative emission inventories reveal that emissions from northwestern New Mexico

far exceed emissions from Reservation sources . Northwest New Mexico and Navajo Nation emissions include emissions from two existing coal-fired power plants and EPA recently approved a PSD permit for a third. Burdening Reservation development with nonattainment requirements in circumstances where (1) Reserv ation monitors show attainment, (2) source apportionment shows the contribution by Reservati on sources to a measured exceedance at New Mexico’s Navajo Lake monitor is not meani ngful, and (3) the Environmental Commission and the Tribe already are aggressively acting to cont rol emissions, would impose a disproportionate burden on the Tribe to help Ne w Mexico achieve attainment with the 2008 revised ozone NAAQS and would be unjust to the Tribe.

In summary, it is the Tribe’s expectation th at EPA will take the Tribe’s environmental justice concerns into account in making its 2008 revised ozone NAAQS area designation for the

Reservation.

C. In the Alternative, Ongoing Studies May Warrant an Unclassifiable Designation for the Reservation.

In the alternative, an unclassifiable designati on for the Reservation should be considered until officials have a more complete understanding of the root causes of the monitored exceedances at New Mexico’s Navajo Lake monito r. The Four Corners Air Quality Group still is in the process of evaluating emission reductions that could be achieved, as well as the overall air quality benefits that could be achieved as a result of implem entation of additional controls on sources in the Four Corners region. Those studi es include ongoing photochemical analyses that will provide more information on the role of VOCs and NOx from different source regions in ozone formation. Before including the Reserv ation in any nonattainme nt area that may be designated as a result of the violation measur ed at New Mexico’s Navajo Lake monitor, therefore, the results of the ongoi ng studies should be obtained a nd considered. For that reason, a designation of unclassifiable for th e Reservation may be warranted.

IV. Conclusion.

In conclusion, the Tribe’s recommendation is that the Reservation ar ea be designated as

“attainment/unclassifiable” for the 2008 revised ozone NAAQS and not included in any nonattainment area that may be designated for northwest New Mexico. The reasons supporting

this recommendation include:

• Monitoring data show that the Reserva tion is attaining th e 2008 ozone NAAQS.

• A source apportionment study shows the cont ribution from Reservation sources to

the violation in northwest Ne w Mexico is not meaningful.

• Prevailing winds blow from the west and southwest onto the Reservation.47 • Emissions from sources located on the Reservation are minimal when compared

to emissions from sources loca ted in northwest New Mexico.

• Emissions from large engine sources on th e Reservation already are within federal

limits and additional emission reducti ons probably are not technologically possible at this time.

• Reservation emissions already are well-cont rolled and limits and controls that will be required on the Reservation as a re sult of (1) the new NSPS emissions regulation, (2) self-imposed conditions to the Tribe’s support for 80-acre infill development, and (3) limits and controls that the Tribe currently is planning to include as part of the minor source pr ogram that it will recommend to the Environmental Commission, will be suffici ent to maintain compliance with the 2008 revised ozone NAAQS. Both the condi tions for the Tribe’s support for infill development and the minor source program that the Tribe plans to

recommend to the Environmental Commi ssion, will require use of presumptive best available control technology (BACT) for not only new or modified minor

sources but also exis ting minor sources. The requir ed use of BACT for all minor

sources on the Reservation is a more stri ngent control requirement than would be required, and will be implemented sooner (within 3 years under the draft minor source program) than probably could be required if the Reservation were included in a nonattainment area (assumi ng the nonattainment area would be categorized as a “marginal” nonattainment area). In addi tion, some of the controls and limits that will be required on the Reservation probably are equivalent to or exceed the controls th at would be required if the Reservation were included in a “marginal” nonattainment area.

• Continued development of the Reservation air program by the Environmental

Commission and the Tribe advance self-d etermination and environmental justice goals. In making its designation for the Re servation area, EPA must consider not only its statutory duty, but the federal interest in promoting tribal selfdetermination, as well as the Tribe’s environmental justice concerns.

Based on the Tribe’s analysis above of the 9-factors th at EPA instructs must be considered in making recommendations for area designations for the 2008 revised ozone NAAQS, and based on the other cons iderations described above, the Tribe recommends that the Reservation be designated “ attainment/unclassifiable ” and not be included in any nonattainment area that may be desi gnated for northwest New Mexico.