MEMORANDUM 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

RESEARCH TRIANGLE PARK, NC 27711 

IDEC202011 

OFFICE OF 

AIR QUALITY PLANNING 

AND STANDARDS 

SUBJECT: Policy for Establishing Separate Air Quality Designations for Areas of Indian Country 

TO: Regional Air Directors, Regions I-X 

Purpose 

This memorandum provides EPA's policy regarding designating areas of Indian country separately from 

adjacent areas for the National Ambient Air Quality Standards (NAAQS), when requested by the 

relevant tribe for a particular area of Indian country. 1 The purpose of this memorandum is to ensure a 

nationally consistent approach for evaluating requests to designate separate areas of Indian country and 

for recognizing Indian country in the 40 CFR Part 81 Tables.Z We may receive a request for a separate 

designation of Indian country in either of two ways: 1) submittal of an initial recommendation by the 

relevant tribe during the Clean Air Act (CAA) section 1 07( d) process following promulgation of a new 

NAAQS, or 2) submittal of a request for a boundary change to a previous designation/redesignation (this 

may arise where Indian country boundaries have been changed due to the acquisition of additional lands; 

EPA deferred a decision on the designation, redesignation, or reclassification; an error was made in the 

previous designation/redesignation; or for other reasons). 

The impetus for this policy is fourfold: 1) the desire to recognize tribal sovereignty in air quality 

management matters affecting their Indian country; 2) the need to ensure protection of air quality in 

Indian country; 3) the desire to increase transparency in the designations process; and 4) the receipt of 

recent requests from several tribes to have a separate attainment or nonattainment area from adjacent 

state or local government areas. 

This memorandum has two main sections. The first section provides background information on EPA's 

process for designating all areas of the country under the CAA. It also describes EPA's new policy for 

evaluating recommendations/requests for separate designations of Indian country, and the potential 

associated implications for tribes. The second section provides background information regarding the 

way in which Indian country areas have typically been displayed in tables located in 40 CFR Part 81 in 

1 Indian country, as defmed at 18 U.S.C. § 1151, means (a) all land within the limits of any Indian reservation under the 

jurisdiction of the United States Government, notwithstanding the issuance of any patent, and, including rights-of-way 

running through the reservation, (b) all dependent Indian communities within the borders of the United States whether within 

the original or subsequently acquired territory thereof, and whether within or without the limits of a state, and (c) all Indian 

allotments, the Indian titles to which have not been extinguished, including rights-of-way running through the same. 2 When areas are designated through CAA section 107(d) and these designations are published in the Federal Register, the 

area boundaries are displayed in tables located in 40 CFR Part 81 . 

Internet Address (URL) • http://www.epa.gov 

Recycled/Recyclable • Printed wHh Vegetable 011 Based Inks on Recycled Paper (Minimum 25% Postconsumer) 
2 

the past. It then discusses EPA's new policy for explicitly addressing Indian country in the 40 CFR Part 

81 Tables. 

Please share this policy with tribal leaders and state agencies in your Region. When corresponding with 

tribal leaders, please provide courtesy copies to tribal environmental directors or tribal air quality staff, 

as appropriate. 

Approach for Evaluating Tribal Requests for Separate Designations of Indian Country for the 

NAAQS 

Background 

CAA section 1 07( d) establishes, among other things, the requirement for EPA to promulgate air quality 

designations for all areas following promulgation of a new or revised NAAQS. Per section 

1 07(d)(a)(A)(i) of the CAA, a nonattainment area is an area that "does not meet (or that contributes to 

ambient air quality in a nearby area that does not meet) ... [a] national primary or secondary ambient air 

quality standard." EPA is required to designate areas as nonattainment, attainment, or unclassifiable 

relative to the promulgated NAAQS. Under section 107(d)(1)(B)(ii) ofthe CAA, EPA must finalize area 

designations no later than two years from the date a new or revised NAAQS is promulgated, unless the 

Administrator has insufficient information to promulgate designations. In such case, the Administrator 

may extend this period for up to one year beyond the original deadline. 

Although section 107(d) does not explicitly reference Indian tribes or Indian country, tribes are able to 

participate in the designations process. For instance, under section 301 (d) and the Tribal Authority Rule 

(TAR) (63 FR 7254, February 12, 1998), tribes may seek treatment in a similar manner as a state (TAS) 

for purposes of section 107(d) designations. Even absent TAS for section 107(d) purposes, EPA may 

solicit air quality information and designations recommendations from tribes for their areas of Indian 

country. In addition, Executive Order (EO) 13175, the Agency's 1984Indian Policy, and the EPA 

Policy On Consultation and Coordination With Indian Tribes (May 4, 2011) call for EPA to consult with 

tribes on actions and decisions, such as designation of their Indian country, that affect their interests. 

The ultimate statutory authority to promulgate designations rests with EPA, and EPA is required under 

the CAA to designate all areas of the country for the NAAQS in a timely manner. If a tribe does not 

submit recommendations, EPA, under its CAA authorities, will promulgate an appropriate designation 

for the relevant area of Indian country. 

In the past, EPA did not have a clearly articulated policy for considering a tribal request for designation 

of its Indian country as a separate area. Several tribes have well-established air programs and have 

engaged in the designations process. Some of these tribes are not only interested in submitting 

designations recommendations to EPA, but are also interested in having their Indian country boundaries 

designated separately from the adjacent area. 

Approach to Designation Decisions for Indian Country 

1) When EPA Does Not Receive a Request/Recommendation for a Separate Designation 

In circumstances where EPA either does not receive an initial designation recommendation from a tribe, 

or receives a recommendation that does not specify designation of a separate area, EPA intends to 
3 

designate the relevant tribe's Indian country as part of the surrounding multi-jurisdictional area, and to 

list the tribe by name in the 40 CFR Part 81 Table (more details regarding this process are provided 

below in the section "Approach for Addressing Indian Country through 40 CFR Part 81 Tables"). In 

addition, to the extent possible, EPA will ensure that a single tribe's Indian country is not inadvertently 

split based on the use of other jurisdictional boundaries (e.g., counties) to designate the surrounding state 

areas. Technical factors (e.g. , topography) and information obtained during consultation with the tribes 

should be used to establish appropriate boundaries. 

The following examples generally illustrate designations that may be appropriate for areas of Indian 

country: 

• Indian country with a regulatory air quality monitor showing a violation of the NAAQS should be 

designated nonattainment. 

• Indian country with a regulatory air quality monitor showing that the NAAQS is being met could be 

designated attainment. However, it should be designated nonattainment when: 1) sources on Indian 

country are contributing to poor air quality in the nearby state area, and/or 2) air quality modeling 

shows that the NAAQS is being violated in the Indian country area.

3 

• Indian country that is lacking a regulatory monitor, and is located within a multi-jurisdictional area 

with a violating regulatory monitor that is not representative of the Indian country could be 

designated unclassifiable. However, the Indian country should be designated nonattainment when: 1) 

sources on Indian country are contributing to poor air quality in the nearby state area, and/or 2) air 

quality modeling shows that the NAAQS is being violated in the Indian country area. 

4 

2) When EPA Receives a Request/Recommendation for a Separate Designation 

If EPA receives an initial designations recommendation or a boundary change request from a tribe 

seeking to have its Indian country designated as a separate area, EPA will make decisions regarding 

these recommendations or requests on a case-by-case basis, and after consultation with the tribe. 5 Listed 

below are several potential scenarios associated with designations recommendations and/or boundary 

change requests from tribes for a separate area: 

• Tribe recommends/requests separate attainment area from adjacent attainment area; 

• Tribe recommends/requests separate attainment area from adjacent nonattainment area; 

• Tribe recommends/requests separate nonattainment area or different area classification from adjacent 

nonattainment area; or 

• Tribe recommends/requests separate nonattainment area from adjacent attainment area. 

As a matter of policy, EPA believes it is important for tribes to make certain submittals associated with 

an initial designations recommendation or boundary change request. These submittals include: 

3 This only applies to the NAAQS for sulfur dioxide (S02) where both monitoring and modeling are used to establish violations. 4 This only applies to the NAAQS for S02 where both monitoring and modeling are used to establish violations. 5 It should be noted that T AS status for purposes of 1 07 (d) is not necessary for Indian country to be designated by EPA separately from the 

surrounding area. 
4 

a) Submittal of a formal request/recommendation from an official authorized to make the request on 

behalf of the tribe. Initial designations recommendations should be submitted on the same schedule 

that applies to states; 

b) Documentation of the boundary of the area of Indian country to which the request for separate 

designation pertains, and concurrence with EPA's intent to include that area in the 40 CFR Part 81 

Table should EPA separately designate the area; and 

c) Submittal of a multi-factor analysis (as described below) to support the recommendation/request. 

It is important for a tribe to submit a formal request/recommendation from an authorized official to 

ensure that EPA considers the tribe's procedural and governmental protocols when evaluating the 

request/recommendation. In addition, given the CAA requirement to designate all areas in a timely 

manner, EPA intends to designate all areas on the same schedule. It is therefore crucial that EPA receive 

initial designations recommendations from tribes no later than the deadline given to states. This timing 

will ensure that EPA has adequate time to conduct appropriate consultation and will allow EPA to make 

informed, timely decisions on requests for a separately designated area of Indian country. 

When submitting a request/recommendation for a separately designated area of Indian country, it is 

important for a tribe to submit documentation of the boundary of the area of Indian country to which the 

request for a separate designation pertains. The tribe should also express concurrence with inclusion of 

the area in the 40 CFR Part 81 Table should EPA separately designate the area. EPA will consult and 

work closely with tribes to address any issues that may be raised by including the Indian country area in 

the 40 CFR Part 81 Table. 

EPA intends to make all decisions regarding a tribe's recommendation/request to designate an area 

separately after all necessary consultation with the tribe and, as appropriate, with other affected entities, 

and after evaluating whether there is sufficient data/information to support such a designation. 

Designation recommendations or boundary change requests for a separate area should include an 

analysis ofthe factors listed below ("multi-factor analysis"). Section 107(d)(1) ofthe CAA defines an 

area as nonattainment if it is violating the NAAQS or if it is contributing to a violation in a nearby area. 

Thus, the purpose of evaluating these factors is to determine the appropriate boundaries encompassing 

the area meeting the CAA's definition of a nonattainment area. In addition, an analysis of these factors 

supports determining whether an area oflndian country located within or next to a larger multijurisdictional area should be excluded from that area and potentially designated separately, or whether it 

should be designated according to the rest of the area. To receive proper consideration, tribes should 

include the following types of data/information in the multi-factor analysis: 6 

• Air Quality Data 

- Does the Indian country area have an attaining or violating air quality monitor? 

- Is the nearest monitor representative of air quality in the area? If so, does it violate the 

standard? 

- Is the data of sufficient quality to be used for boundary decisions and/or designations 

purposes? 

- If there is no monitor in the Indian country area, is there other technical information available 

that characterizes air quality in the Indian country area? 

6 Note: The questions below each factor are included for illustrative purposes only, and are not intended to be comprehensive. 
5 

• Emissions-Related Data 

Source emissions data 

What are the actual and estimated emissions from sources located in and around the area of 

Indian country? Significant emissions levels in a nearby area indicate the potential for the 

area to contribute to observed violations. 

How far is the Indian country area from emissions sources in the adjacent area? 

Traffic and commuting patterns 

Where are the major transportation arteries? Is information on traffic volume and commuting 

in and around the violating area available? 

Is the Indian country area being impacted by traffic crossing Indian country to get to another 

area? 

Population density and degree of urbanization 

What are the population characteristics and trends of the area and the patterns of commercial 

development as indicators of the probable location and magnitude of emissions sources? 

• Meteorology 

How do meteorological conditions affect the fate and transport of emissions from sources on 

or nearby the area of Indian country? 

• Geography/Topography 

What are the physical features of the land that might define the airshed and, therefore, affect 

the formation and distribution of pollution over the Indian country area? Mountains or other 

physical features may affect the location of emissions sources and the distribution of 

emissions, and may help define the boundaries of violating areas and areas contributing to 

violating areas. 

• Jurisdictional Boundaries 

What are the existing jurisdictional boundaries for the purposes of providing a clearly 

defined legal boundary of the area pertaining to the designation request and carrying out the 

air quality planning and enforcement functions for nonattainment areas? For example, this 

might include Indian country, state, county government, or metropolitan planning 

organization areas. 

In addition to the information above, tribes may submit any other information that they believe is 

important for EPA to consider. Consistent with the multi-factor analysis conducted by the states, there 

may be instances where not all of the above-listed factors are relevant to a specific request. For example, 

if a tribe were to request the designation of a separate attainment area from an adjacent attainment area, 

it is possible that only the air quality data factor and/or the jurisdictional boundaries factor would be 

applicable to the given situation. We encourage Regional Offices, when requested, to assist tribes with 

developing their multi-factor analyses to determine which factors are most relevant to the specific 

request for a separate area. 

Additional information is included below regarding consideration of the information/data submitted by a 

tribe for the air quality data and jurisdictional boundaries factors. Given the complexity of issues 

associated with the use of different data sources to support the air quality data factor, we feel it is 
6 

important to clearly articulate how air quality data should be considered in the multi-factor analysis 

submitted by a tribe. Through this memorandum, EPA is setting a new policy for recognizing tribal 

jurisdiction in the designations process. Therefore, the jurisdictional boundaries factor should be 

considered differently for a tribe than it is considered for a state or county. 

Air Quality Data Factor Analysis 

Data from both non-regulatory monitors and regulatory monitors can be included as part of the air 

quality data factor analysis submitted by a tribe. However, while qualified data from regulatory monitors 

can be used to determine the designation status (attainment, nonattainment, or unclassifiable) for an area 

of Indian country, data from non-regulatory monitors may only be used to support a geographic 

boundary determination for that designation category. Regulatory and non-regulatory monitors are 

defined as follows: "Regulatory" monitors are those that: (1) have a monitoring objective that is 

intended for comparing design values against the level of the NAAQS (NAAQS Comparison), and (2) 

have adequately achieved the quality assurance and data requirements for regulatory decision making. 

"Non-regulatory" monitors are those that: (1) have been designated as a "non-regulatory" monitor type 

in EPA's Air Quality System, meaning that they have monitoring objectives other than NAAQS 

Comparison, and therefore are not required to meet all of the quality assurance and data requirements 

necessary for regulatory decision-making, or (2) may have the objective of "NAAQS Comparison" and 

have not adequately achieved the quality assurance and data requirements necessary for regulatory 

decision-making. 

EPA recognizes that when considering tribal recommendations for separate area designations, 

appropriate air quality data may not be available for the relevant areas of Indian country-either due to 

the absence of a monitor in Indian country, or due to concerns regarding data accuracy. It is also 

possible that despite the absence of air quality data for the Indian country area, other technical 

information is available that characterizes air quality in the Indian country area. For example, a 

proximate state regulatory monitor could be determined to be representative of air quality in the Indian 

country area. Or, for some pollutants, modeling or emissions inventory data may be useful. In these 

circumstances, it may be appropriate for other technical information to be used in the air quality data 

factor analysis. However, in cases where a tribe submits a recommendation for a separate attainment 

area from an adjacent nonattainment area, or a separate nonattainment area from an adjacent attainment 

area, such recommendations would be best supported by air quality data from a regulatory monitor in 

the relevant area of Indian country. 

Jurisdictional Boundaries Factor Analysis 

When evaluating the multi-factor analysis submitted by a tribe, it is important to recognize tribal 

sovereignty and the jurisdictional status of Indian country in the decision-making process. Therefore, the 

jurisdictional boundaries factor analysis should recognize that tribes retain important sovereign 

authorities over their members and territories, and that jurisdiction in Indian country generally rests with 

the relevant tribe and the federal government, not with states. In general, when deciding whether to grant 

a tribal request for designation of a separate area, the jurisdictional boundaries factor analysis may bear 

the most weight in the following circumstances: 

• A recommendation/request for a separate attainment area where all of the adjacent areas are 

designated attainment; 
7 

• A recommendation/request for a separate attainment area where there is an adjacent 

nonattainment area, when a regulatory monitor in Indian country demonstrates that the NAAQS 

is being met, and there are no sources in Indian country contributing to nonattainment in the 

adjacent area based on an analysis of the factors described above; 

• A recommendation/request for a separate nonattainment area where all adjacent areas are 

designated attainment, when a regulatory monitor in Indian country demonstrates a NAAQS 

violation and an analysis of the factors described above does not support inclusion of areas 

outside the Indian country boundary based on their contribution to air quality at that monitor; and 

• A recommendation/request for a separate nonattainment area where there is an adjacent 

nonattainment area, when an analysis of the factors above indicates that there are no sources in 

Indian country contributing to nonattainment in the adjacent area. 

Example Decision-Making Scenarios 

Several example decision-making scenarios for considering tribal recommendations/requests are 

included below. These scenarios are meant to provide general examples, and do not suggest a definitive 

decision. Ultimately, EPA's decision regarding whether to designate an area of Indian country 

separately will depend upon a consideration of all factors and other relevant data/information submitted 

by a tribe with their recommendation/request. 

• Tribe submits a recommendation/request for a separate nonattainment area with the same or a 

different area classification (e.g., Moderate, Serious, etc.) than an adjacent nonattainment area. 

Tribe either has its own regulatory monitor demonstrating violation of the NAAQS or has 

shown that a proximate regulatory monitor violating the NAAQS outside of Indian 

country is sufficiently representative of air quality in the Indian country area. 

There are no significant emissions sources in Indian country that are contributing to 

nonattainment in the adjacent area. 

Indian country area is impacted only by sources within the Indian country. 

-7 Indian country area could be designated as a separate nonattainment area or with a 

different area classification. 

• Tribe submits a recommendation/request for a separate nonattainment area from an adjacent 

nonattainment area. 

Tribe either has its own regulatory monitor demonstrating violation of the NAAQS or has 

shown that a proximate regulatory monitor outside of Indian country violating the 

NAAQS is sufficiently representative of air quality in the Indian country area. 

Indian country area has emissions sources that are contributing to nonattainment in the 

adjacent state area. 

Indian country area is impacted by sources outside of Indian country. 

Indian country area is meteorologically and topographically integrated with the 

surrounding area. 

-7 Indian country area could be designated as part of a multi-jurisdictional nonattainment 

area, such that the tribe is one of the governing bodies within the area. 

• Tribe submits a recommendation/request for a separate attainment area adjacent to a 

nonattainment area. 

- Tribe has its own regulatory monitor demonstrating the NAAQS is being met. 
8 

There are no significant emissions sources in the Indian country area that are contributing 

to nonattainment in the adjacent area. 

Indian country area is separated from adjacent nonattainment area by topography or other 

geographic features. 

-7 Indian country area could be designated as a separate attainment area. 

• Tribe submits a recommendation/request for a separate nonattainment area adjacent to or within 

a surrounding attainment area. 

Tribe has its own regulatory monitor demonstrating the NAAQS is being violated. 

-7 Indian country area could be designated as a separate nonattainment area. 

• Tribe submits a recommendation/request for a separate attainment area adjacent to or within a 

surrounding attainment area. 

Tribe either has its own regulatory monitor demonstrating attainment ofthe NAAQS or 

has shown that a proximate regulatory monitor outside of Indian country that is attaining 

the NAAQS is sufficiently representative of air quality in the Indian country area. 

-7 Indian country area could be designated as a separate attainment area. 

Potential Implications of Separately Designated Areas of Indian Country 

Pursuant to the TAR, tribes are not treated as states with respect to the plan submittal and 

implementation deadlines for NAAQS-related requirements (See 40 CPR§ 49.4(a)). Therefore, even if a 

tribal request for a separate area is granted, that tribe is not required to submit a tribal implementation 

plan (TIP). Although we encourage tribes to develop plans to address NAAQS-related requirements, 

where tribes do not develop TIPs, EPA is authorized to promulgate federal implementation plan (PIP) 

provisions as are necessary or appropriate to protect air quality. (See 49 CPR§ 49.11(a)). In a 

nonattainment area, the goal is to implement a strategy that will allow the area to meet the standards by 

reducing specific pollutants below the levels of the NAAQS. A PIP or TIP may include, as necessary or 

appropriate: (a) an emissions inventory to identify the sources of air pollution, their location, and the 

types of pollutants emitted; (b) enforceable emission limits that will require application of all 

Reasonably Available Control Measures (RACM), including adoption ofReasonably Available Control 

Technology (RACT) for existing pollution sources; (c) evidence that the emission limits will reduce 

emissions enough to prevent NAAQS violations in Indian country and in other areas (i.e., an attainment 

demonstration) and demonstrate reasonable further progress towards attainment; (d) a new source 

review preconstruction permit program to ensure that new and modified sources of pollution do not 

impede progress toward cleaner air; 7 and (e) contingency measures to apply in the event the area fails to 

meet any attainment or progress goals. 

During consultation, EPA Regional Offices should ensure that tribes interested in submitting a 

recommendation/request for a separate area designation are aware of the implications for their tribe 

should such a recommendation/request be granted. For example, in order for a separately designated 

nonattainment area in Indian country to be redesignated to attainment, the tribe or EPA would need to 

demonstrate that the area attains the standard and that it meets necessary or appropriate redesignation 

criteria, including a TIP or PIP that provides for ongoing maintenance of the NAAQS. Also, small 

7 On July 1, 2011, EPA promulgated a FIP, entitled "Review of New Sources and Modifications in Indian Country," to ensure that Clean 

Air Act permitting requirements are applied consistently to facilities in Indian country. (76 FR 38748). Interested tribes can assist EPA with 

implementation of the federal rules set forth in the FIP through a delegation agreement with EPA Tribes can also develop and seek 

approval of a TIP to administer these permitting programs under their own laws. 
9 

separate nonattainment areas with few sources of emissions may experience difficulties demonstrating 

reasonable further progress and attainment from sources within the area, should they elect to develop 

such demonstrations. 

Another area that Regions should discuss with tribes during consultation is how general and 

transportation conformity would apply in a separately designated tribal nonattainment area. Activities in 

areas that are designated nonattainment that are conducted or supported by Federal agencies must 

"conform" to the purpose of an applicable implementation plan, as required by section 176(c) ofthe 

CAA. The EPA's general conformity rules apply to Federal activities within nonattainment areas and 

areas that have moved from nonattainment to maintaining the standards, i.e., areas that are redesignated 

as attainment. A Federal agency must demonstrate, prior to approving, permitting, licensing, providing 

financial support for, or otherwise supporting a project, that its action conforms to applicable 

requirements in the area's approved implementation plan and will not cause or contribute to NAAQS 

violations or delay timely attainment. Transportation conformity rules apply to highway and transitrelated activities, and all other types of Federal activities are governed by general conformity rules. 8 The 

transportation conformity rule requires transportation agencies to estimate the total motor vehicle 

emissions that would result from the area's transportation system if the proposed transportation projects 

are built. These emissions must be within levels that the applicable implementation plan predicts are 

consistent with attainment. 

If general conformity obligations are determined to apply to emissions from a Federal agency action, the 

general conformity rules provide Federal agencies with the following options for demonstrating 

conformity in nonattainment or maintenance areas: (1) obtaining emission offsets (generated in the same 

area or certain nearby areas) for the total emissions from the new project, (2) showing that the project's 

emissions are already included in, or accommodated by, the applicable SIP for the area (or in the 

absence of an applicable SIP, showing that the project's emissions will not increase the baseline 

emissions used in the most current emissions inventory), or (3) obtaining a written commitment from the 

Governor for the area, or the Governor's designee for SIP actions, to include the project's emissions in a 

forthcoming revision of the applicable implementation plan. Tribes that choose to engage in the 

implementation planning process through submittal of a TIP may find it easier to address any general 

conformity issues associated with their separately designated areas of Indian country. EPA plans to 

provide tribes with training and/or guidance on transportation and general conformity. 

In an attainment or unclassifiable area the goal is to maintain air quality that is cleaner than the NAAQS. 

A tribal or Federal air quality program in such areas will generally contain enforceable emission limits 

for existing emission sources, a program to limit the impacts of emissions from new and modified 

stationary sources, and provisions to prevent significant contribution by sources located in Indian 

country to NAAQS violations in other areas. Major sources located in areas of Indian country that are 

designated attainment or unclassifiable for any pollutant would be subject to the Federal program for the 

Prevention of Significant Deterioration (PSD) upon the date that designations under the standard 

become effective.9 

8 It should be noted that under the Federal Lands Highways Program, 23 US.C §§202(d), 204, as amended by the Safe, Accountable, 

Flexible, Efficient Transportation, Equity Act: A Legacy for users (SAFETEA-Lu) authorization to promulgate and implement regulations 

regarding planning and construction of Title 23 highway activities, as well as Title 49 transit-related activities on Indian reservations are 

entrusted to the Secretary of the Interior through the assistance of the Bureau oflndian Affairs. 9 Major sources are those emitting either 100 tons per year or 250 tons per year, depending upon the source category. For more information 

on PSD, visit: http://www.epa.gov/NSR/psd.html. 
10 

Carrying out this Policy: Guidance to Tribes 

Due to the implementation considerations associated with this policy, as described above, EPA believes 

that it is important not only to provide additional assistance to tribes interested in submitting 

recommendations/requests for separately designated areas, but also to provide them with additional 

guidance regarding any requirements associated with designating these areas. Therefore, EPA intends to 

provide tribes with additional technical support through conference calls, webinars, and/or guidance 

document(s) to assist them with carrying out this policy. Such technical support will include, but is not 

limited to, the following subjects: 

• How to evaluate the factors in a multi-factor analysis; 

• Examples of supplemental data that could be used to support the air quality data factor; 

• How to submit a request for a boundary change; 

• Requirements for a separately designated area of Indian country to be redesignated from 

nonattainment to attainment; 

• How to address exceptional events; and 

• Addressing transportation and general conformity. 

Approach for Addressing Indian Country through 40 CFR Part 81 Tables 

Background 

When areas are designated through CAA section 107(d) and these designations are published in the 

Federal Register, the area boundaries are displayed in tables located in 40 CFR Part 81. In general, 

Indian country has historically been addressed in the 40 CFR Part 81 Tables either through a footnote or 

through "exclusion" of Indian country from a particular county's designation. 

Tables 1 and 2 below represent examples. 

In Table 1, the San Carlos Apache Indian Reservation is both explicitly excluded from the Hayden PM10 

nonattainment area as well as implicitly included as part of the "Rest of State" unclassifiable area. 
11 

Table 1. Indian Country Excluded from Surrounding Area 

Environmental Protection Agency 

Arizona-PM-10 

Designated Area 

Townships: 

Pinal ancl Gila Counties: 

T7S-R21W, R22W; 

T8S·R21W, R22W, R23W, 

R24W 

T9S-R21W, R22W, R23W, 

R24W, R25W; 

T10S-R21W, R22W, R23W, 

R24W, R25W 

Design at ion 

Dale Type 

Hayden planning area ....................................................... 11115190 Nonattainment 

T1 S, R13E (sections 7-36); Tl S, R14E (sections 25-

36);T2S, R13E; T2S, R14E; T2S, R15E; T3S, R13E; 

T3S, R14E; T3S, R15E; T3S, R16E (except that portion in the San Carlos Apache Indian Reservation); 

T4S, RI3E;T4S, RI4E;T4S, RI5E;T4S, R16E;T5S, 

RI3E; T5S, R14E; T5S, R15E; TSS, RISE; T6S, 

RI3E; T6S, RI4E; T6S, RISE; and T6S, R16E. 

Miami planning area.......................................................... 11/15/90 Nonattainment 

T1N, R13E; T1N, RI4E; T1N, R15E; T1S, RI3E (sections 1-6); TIS, R14E (sections 124); T1S, R141

12E; 

and TIS, RISE. 

Gila County (part): 

Payson: T10N, sections 1-3, ............................................ 08/26/02 Attainment 

IQ-15, 22-27, and 34-36 of R9E; T11N, sections 1-3, 

1Q-IS, 22-27, and 34-36 of R9E; T1Q-11N, RIOE; 

T10N, sections 4-9, 16-21, and 28-33 of R11E; 

T11N, sections 4-9, 16-21, and 28-33 of R11E. 

Mohave County (part): August Attainment 

Bullhead City: T21 N, R21 W, excluding Lake 

Mead National Recreation Area: T20N, R21-

22W; TI9N, R22W excluding Fort Mohave Indian Reservation. 

26,2002 

Rest of State ..... - .............................................................. 11/15190 Unclassifiable 

§81.303 

Classification 

Date Type 

11115/90 Moderate. 

11/15190 Moderate. 

In Table 2, no affected area of Indian country in Arizona is listed by name. Instead, the footnote in Table 

2 indicates that each designated area "Includes Indian Country located in each county or area, except as 

otherwise specified." In this example, there is no such explicit separate specification in the table, so 

affected areas of Indian country are not identified. 

Table 2. Indian Country Included in Footnote 

Arizona-PM2.5 

Designated area 

Dale' 

Statewide: 

Apache County ........................................................................................ .. 

Cochise County ........................................................................................ .. 

Coconino County ..................................................................................... .. 

Gila County ............................................................................................... . 

Graham County ......................................................................................... . 

Greenlee County .................................................................. .................... .. 

La Paz County ....................................................................... .... ............... . 

Maricopa County .................................................................... .................. .. 

Mohave County ........................................... ........................... ................... . 

Navajo County ............. ............................................................................ .. 

Pima County ............................................................................................ .. 

Pinal County .............................................................................................. . 

Santa Cruz County ....... ........................................................................... .. 

Yavapai County ........................................................................................ .. 

Yuma County ..................................... ....................................................... . 

• Includes Indian Country located in each county or area, except as otherwise specified. 

'This date is 90 days after January 5, 2005, unless otherwise noted. 

Designation" 

Type 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 

Unclassifiable/Attainment. 
12 

Approach 

EPA believes it is appropriate to explicitly identify Indian country in the 40 CPR Part 81 Tables. 

Therefore, EPA intends to use the following approach: 

• For instances where an area of Indian country is designated as part of an adjacent area, the area 

of Indian country will be listed by name in the 40 CFR Part 81 Table. 

• For instances where an area of Indian country is designated separately from the adjacent_area, the 

separately designated area of Indian country will be specified in the 40 CPR Part 81 Table along 

with its associated designation status. Separately designated areas of Indian country will be 

identified using appropriate information included in an EPA decision on a tribe's TAS 

application, if one exists, for designations or other purposes, or from other appropriate sources.

10 

Tables 3 and 4 provide mock-ups for explicitly identifying areas oflndian country in the 40 CPR Part 81 

Tables. 

to As noted earlier in this document, TAS is not required for a tribe to submit designations recommendations. 

r. 
13 

Table 3. Arizona (2008 8-Hour Ozone Standard) 

[MOCK-UP to Show Separately LISTED Areas of Indian Country] 

I 

Designated area 

I 

Designation Classification 

Date1 Type Date1 Type 

[ Phoenix-Mesa, AZ:2 

I Nonattainment [ M0derate 

Maricopa County (part) 

T1N,R1E;T1N,R2E;T1N,R3E;T1N,R4E; 

etc ... 

Pinal County (part) 

Apache Junction: TlN, R8E; TlS, R8E (Sections 

1 through 12) 

Fort McDowell Indian Reservation (Fort McDowell 

Yavapai Nation)3 

Gila River Indian Reservation (Gila River Indian 

Communityi 

Salt River Reservation (Salt River Pima-Maricopa 

Indian Communityi 

Rest of State

2 Unclassifiable/ I Attainment 

Apache County 

Cochise County, etc ... 

(or omit county-by-county listing) I Rest of Indian country' ID Unclassifiable/ I I Attainment 

Chemehuevi Reservation (Chemehuevi Indian Tribe) 

Colorado River Indian Reservation (Colorado River 

Indian Tribes), etc ... 

(or omit tribe-by-tribe listing) 

1 This date 1s (INSERT DATE), unless otherw1se noted 2 Excludes Indian country located in each county or area, unless otherwise noted. 

3 Includes all Indian country located within the exterior boundaries of the State of Arizona, except for Indian country 

separately designated in this Table. 

I 

I 

I 

I 

I 

I 
I 

14 

Table 4. Arizona (2008 8-Hour Ozone Standard) 

[MOCK-UP to Show Separately DESIGNATED Areas of Indian Country] 

Designation I Classification 

Designated area 

~~l Type I Date

1 II Type 

Phoenix-Mesa, AZ:

2 Nonattainment RModerate 

Maricopa County (part) 

TlN,RlE;TlN,R2E;TlN,R3E; 

I I TlN,R4E;TlN,R5E;TlN,R6E; 

TlN, R7E; TlN, Rl W; etc ... 

Pinal County (part) ILJ LJ 

Apache Junction: TlN, R8E; TlS, 

I R8E (Sections 1 through 12) 

Fort McDowell Indian Reservation (Fort Nonattainment I Moderate 

McDowell Yavapai Nation)3 

Gila River Indian Reservation (Gila River Nonattainment Marginal 

Indian Community)3 

Salt River Reservation (Salt River Pima- Nonattainment Moderate 

Maricopa Indian Communityi 

Rest of State2 Efiable/Att · 

Apache County 

Cochise County, etc ... 

(or omit county-by-county listing) 

Rest of Indian count~ Unclassifiable/ Attainment 

Chemehuevi Reservation (Chemehuevi 

Indian Tribe) 

Colorado River Indian Reservation 

(Colorado River Indian Tribes), etc ... 

(or omit tribe-by-tribe listing) - 1 This date 1 (INSERT DATE) unles otberwt e noted 

2 Excludes Indian country located in each county or area, unless otherwise noted. 

3 fncludes all Indian country located within the exterior boundaries of the State of Arizona, except for Indian country 

separately designated in this Table. 

I 

I 
15 

Questions Regarding This Policy 

Staff in EPA's Office of Air Quality Planning and Standards are available for assistance throughout the 

designations process. Questions on this policy may be directed to Kristin Riha at (919) 541-2031 or 

riha.kristin@epa.gov; or Angel McCormack at (919) 541-3588 or mccormack.angel@epa.gov. 

cc: Anna Wood, OAQPS 

Lydia Wegman, OAQPS 

Richard Wayland, OAQPS 

Greg Green, OAQPS 

Peter Tsirigotis, OAQPS 

Margo Oge, OTAQ 

Sarah Dunham, OAP