Chapter 2 Page 21

Chapter 2 Characteristics of

Implementation Plans

This chapter explains what an implementation plan is,

compares tribal implementation plans (TIPs) and state

implementation plans (SIPs), introduces the technical

information that can support a TIP and the potential

elements of a TIP, and explains the other elements that may

accompany a TIP when it is submitted to the Environmental

Protection Agency (EPA). More detailed information about

the technical information that can support a TIP (such as

emission inventories and air quality modeling) is found in

Chapter 3. More detailed information on the potential

elements of a TIP is found in Chapter 4.

Implementation

Plan Basics

What is an Implementation

Plan?

As mentioned in Chapter 1, EPA established the National

Ambient Air Quality Standards (NAAQS) for the six

criteria pollutants to protect public health and the

environment. An implementation plan is a set of programs

and regulations developed by the appropriate regulatory

agency in order to assure that these air quality standards are
 Chapter 2 Page 22

attained and maintained. These plans can be developed by

the state, tribe, or EPA, depending on which has

jurisdiction in a particular area.

How do TIPs compare to

SIPs?

The Clean Air Act (CAA) requires each state to adopt a

SIP. Several sections of Title I of the CAA provide

structured, mandatory requirements for SIP contents.1 The

EPA’s requirements for SIPs are laid out in Title 40 of the

Code of Federal Regulations (CFR) part 51. The SIP

programs can reflect each state’s particular needs and air

quality issues, but they must meet certain federal standards.

If a state fails to submit an approvable SIP within the

schedules provided in the CAA, sanctions are imposed on

the state and the EPA is required to develop and enforce a

federal implementation plan (FIP) to implement the

applicable CAA requirements for that state.

Section 301(d) of the CAA as amended in 1990 and as

implemented through the Tribal Authority Rule (TAR),

provides for tribal implementation of CAA programs. 

Tribes can choose to implement certain CAA programs by

developing a TIP. TIPs are different from SIPs. TIPs:

» Are optional

» Are modular

» Have flexible submission schedules

» Allow for joint tribal and EPA management

" TIPs are optional The CAA requires each state to adopt a SIP. Unlike states,

tribes are not required to adopt an implementation plan. In

the Tribal Authority Rule, EPA recognized that not all

tribes will have the need or the desire for an air pollution

control program. Where tribes elect not to develop a TIP

EPA will adopt, without unreasonable delay, such Federal

implementation plan provisions as are necessary or

appropriate to protect air quality. However, where tribes

elect to adopt rules to regulate sources of criteria air

pollutants under their jurisdiction, these rules will form the

core of a TIP.

" TIPs are modular The TAR offers individual tribes the flexibility to include

in a TIP only those TIP elements that address their specific

air quality needs and that they have the capacity to manage. 
 Chapter 2 Page 23

The modular approach

gives the choice to adopt

only the TIP elements

considered most relevant

to the air quality needs of

each tribe and that each

tribe has the capacity to

manage. 

Under this modular approach, the TIP elements the tribe

adopts must be “reasonably severable” from the package of

elements that can be included in a whole TIP. 

“Reasonably severable” means that the elements selected

for the TIP are not integrally related to elements that are not

included in the TIP, and are consistent with applicable

CAA and regulatory requirements.2

TIP elements are discussed in more detail in the next

section of this chapter and in Chapter 4.

" TIPs have flexible

submission schedules

Neither the CAA nor the TAR requires tribes to develop

TIPs. Therefore, unlike states, tribes are not required to

meet the implementation plan submission deadlines or

attainment dates specified in the CAA. Tribes can establish

their own schedules for developing TIP elements (e.g.,

regulations to limit emissions of a specific air pollutant)

and submitting them to EPA. Tribes will also not face

sanctions for failing to submit or for submitting incomplete

or deficient TIPs. 

Once TIP elements are approved, EPA will expect tribes to

diligently implement them. Therefore, tribes should work

with their EPA Regional Offices to develop schedules to

expeditiously implement the regulations and programs

included in TIP elements. If a tribe fails to implement an

approved regulation or program, EPA may exercise it’s

authority to enforce the TIP. EPA could also sanction the

tribe (e.g., withhold grant funds) for failing to implement

an approved program.3

" TIPs allow for joint

tribal and EPA

management

Joint management can be helpful because it allows tribes to

concentrate on specific areas of interest or need. Tribes can

revise a TIP and take on or give back programs based on

changes in tribal need or capacity. The EPA may regulate

emission sources that the tribe chooses not to include in a

TIP if it is necessary or appropriate to adequately protect air

quality. The EPA may also promulgate federal regulations

initially through a FIP, and later approve tribal rules

covering particular types of sources or activities in a TIP. 
 Chapter 2 Page 24

This type of joint management should result in a program

fully protective of tribal air resources.

For example, your tribe may initially want to adopt and

implement rules for open burning and construction

activities to address particulate matter concerns, but defer

regulation of industrial sources of emissions to EPA. At a

later date, your tribe may decide to adopt rules for industrial

sources of emissions as well. This modular approach

would allow for an easy transition from the federal

industrial source rules to the tribal rules. When the tribal

rules are approved, they become the federally enforceable

requirements and replace the existing FIP requirements. 

It is important to remember that as part of your tribe’s

overall air program, the tribe may develop requirements

that are not part of your TIP. These requirements can

support other environmental and cultural issues that are

important for the tribe and do not have to be approved by

EPA. For example, a tribe may want to adopt regulations

on residential wood combustion or open burning (as many

tribes have already done).

Where are the Statutory and

Regulatory Requirements

for a TIP?

Title I of the Clean Air Act contains the requirements that

SIPs and, as appropriate, TIPs must meet.4

 However, in

some instances these regulatory requirements may be

inconsistent with the Clean Air Act as amended in 1990,

and to facilitate SIP development under the amended CAA,

EPA has issued several guidance documents that may be

useful to consult if you are developing a TIP.

Your tribe should also review EPA’s Tribal Authority Rule

(TAR) [40 CFR Part 49] which has specific provisions

regarding TIPs. In addition, the preamble notices

accompanying the proposed and final TAR provide

guidance regarding TIP requirements.5

It is important to keep in mind that TIP requirements may

vary depending on the specific TIP elements your Tribe

intends to adopt. For this reason, and in light of the large

body of potentially applicable requirements, EPA strongly

encourages you to speak with your Regional contact to

determine the requirements that may apply to your specific
 Chapter 2 Page 25

An air monitoring station at

the Tribal Air Monitoring

Support (TAMS) Center in

Las Vegas.

TIP. Your EPA Regional contact can also identify other

relevant guidance documents that may be useful for you to

consult as you develop your TIP.

Developing a TIP

What technical information

do you need to develop a

TIP?

Information on existing emissions and ambient air quality

in the area over which your tribe seeks to run a TIP will

help determine your air quality goals and which TIP

elements to develop. Two mechanisms for obtaining such

data, emissions inventories and air quality monitoring, are

introduced below and discussed in greater detail in 

Chapter 3.

" Emissions Inventory An emissions inventory is a quantitative list of the amounts

and types of pollutants that are entering the air from each

source on your reservation. Your inventory may be

comprehensive, looking at all pollutants, or focused on only

selected pollutants of concern. The fundamental elements

in an emissions inventory are the characteristics and

locations of the sources, as well as the amounts and types of

pollutants emitted. A tribe may want to develop an

emissions inventory to help identify air pollution concerns

and determine the air quality goals your tribe wants to

address in your TIP.

" Air Quality Monitoring The concentration of various air pollutants can be measured

using devices called monitors. Monitoring data collected

on or in the vicinity of your reservation can help determine

if the existing air quality on your reservation meets the

NAAQS and set air quality goals. Your tribe may monitor

the short-term and annual concentrations of pollutants that

your tribe is concerned about to determine if those

concentrations are above or below the NAAQS. 

Alternatively, if your tribe decides not to develop an air

quality monitoring network, it may be able to utilize air

quality data from nearby monitors operated by other entities

such as states, regional planning organizations, or the

federal government. And, your tribe can still develop a TIP

without already having monitoring data as some TIP

elements, such as regional haze plans, can be developed
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without knowing the exact current concentrations of

pollutants on the reservation.

What are the potential

elements in a TIP?

The CAA and TAR give EPA broad discretion in approving

TIPs to address the specific air quality problems and

circumstances of individual tribes. As described above, a

TIP can address one or more relevant criteria pollutants,

and may include selected elements of a complete NAAQS

implementation plan, provided those elements are

reasonably severable from the other CAA elements not

included in the TIP. The potential elements of a TIP are:

» Maintenance strategies

» Attainment strategies

» Source preconstruction permits

» Regional haze plans

The EPA believes these elements are “reasonably

severable” from each other and can be approved for tribes

to implement. These elements are briefly described below;

more detailed descriptions are provided in Chapter 4. 

Tribes may elect to develop TIPs that include one or several

of these elements. Elements that are initially excluded from

a TIP can be included at a later date. The EPA expects that

in some cases, a TIP may need to be supplemented with a

FIP if it is necessary or appropriate, to protect air quality.

" Maintenance Strategy

(for areas that attain the

NAAQS or are

unclassifiable)

In an attainment area, the air quality is as clean as or

cleaner than the NAAQS for all of the criteria pollutants.6

Areas for which there are insufficient air quality data to

determine if the NAAQS are met may be designated

“unclassifiable” and are treated as attainment areas. If your

reservation is in an attainment or unclassifiable area, a goal

of your TIP could be to maintain that good air quality. The

reservation does not need a NAAQS designation however,

for your tribe to develop a TIP . A maintenance strategy

includes:

» Enforceable emission limits for existing emission

sources and
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» Evidence the emission limits are adequate to prevent

NAAQS violations on the reservation and in other

jurisdictions

» Schedules for implementing emission limits

expeditiously 

Tribes may submit a TIP that includes enforceable emission

limits and compliance schedules for a single source, and

not include evidence that the emission limits are adequate

to prevent NAAQS violations in other jurisdictions. The

EPA can fully approve such TIP elements as progress

toward developing a more complete implementation plan

that meets the tribes air quality goals. The EPA may also

evaluate whether the emission units are adequate to prevent

NAAQS violations, if necessary and appropriate.

Construction of new sources on the reservation could add

enough emissions that the goal of the TIP to maintain the

NAAQS would not be met. Therefore, the tribe may also

want to include in their TIP source preconstruction permit

programs, one of the next severable elements discussed.

" Attainment Strategy

(for areas that are in

nonattainment for

NAAQS)

A goal of a TIP in an area with air quality worse than the

NAAQS for some criteria pollutants (a “nonattainment”

area) would be to reduce the concentrations of those

pollutants below the NAAQS.6

 The EPA and the tribe can

work together to develop an attainment strategy for a

nonattainment area. An attainment strategy generally

includes:

» Enforceable emission limits that will require application

of at least Reasonably Available Control Measures

(RACM) or Reasonably Available Control Technology

(RACT) for existing sources

» Evidence the emission limits are adequate to prevent

NAAQS violations on the reservation and in other

jurisdictions (an “attainment demonstration”)

» Schedules for implementing emission limits and

evidence that the compliance schedules will produce
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The Dexter Road Project of

the Oneida Tribe of Indians

of Wisconsin. The Oneida

Reservation contains

approximately 65,000 acres. 

The Dexter Road Project

involves native grassland

restoration and reforestation.

(Photo courtesy of the Oneida

Tribe of Indians of

Wisconsin.)

annual reductions in emissions until the NAAQS are

met

» Additional regulation to achieve emission reductions

beyond those necessary to meet the NAAQS, to be held

in reserve and used only if the primary regulations do

not result in attainment of the NAAQS (“contingency

measures”)

Tribes may submit a TIP that includes enforceable emission

limits and compliance schedules for a single source, and

not include evidence that the emission limits are adequate

to prevent NAAQS violations. The EPA can fully approve

such TIP elements as progress toward developing a more

complete implementation plan that meets the tribes air

quality goals. 

When tribal lands are part of a multi-jurisdictional area, if

the tribe does not show that the emission limits in their TIP

are adequate to prevent NAAQS violations, EPA will

review the emission limits and compliance schedules to

assure that they will not interfere with the overall plan to

attain the NAAQS in the area. In cases where sources on

tribal lands would interfere with an area meeting it’s

attainment date, EPA will develop a FIP to reduce

emissions from those sources, where necessary and

appropriate, since the tribe is not required to meet the

attainment date. 

Construction of new sources on the reservation could add

enough emissions that the goal of the TIP to attain the

NAAQS would not be met. Therefore, the tribe may also

want to include in their TIP source preconstruction permit

programs, the next severable elements discussed.

The ambient air quality on the reservation may violate the

NAAQS because emissions from sources located outside of

your reservation are transported there. Sources of

pollutants outside the TIP area may be a concern if your

reservation is adjacent to or surrounded by a nonattainment

area, or if it is downwind of major sources of emissions that

are not under your tribe’s jurisdiction. Although your tribe

can only regulate sources in the area covered by its
 Chapter 2 Page 29

approved TIP, the Regional Air Quality section in Chapter

4 describes ways your tribe can address this problem.

" Source Preconstruction

Permit Programs

The CAA provides for programs to review and permit new

major sources and major modifications to existing sources

as part of an overall strategy to attain or maintain the

NAAQS.6 These programs are collectively known as New

Source Review. 

» The Prevention of Significant Deterioration (PSD)

program is a federal program for attainment and

unclassifiable areas. Under this program, new major

sources and major modifications to existing sources

must obtain a PSD permit before construction.7

 Tribes

can adopt a PSD program of their own that meets EPA

requirements, or a tribe can accept delegation to

manage the federal PSD program.

» The nonattainment New Source Review (NSR) program

is for nonattainment areas. Tribes can adopt statutory

requirements for an NSR program of their own to

regulate emissions from new major sources and major

modifications to existing sources. In the future, when

EPA establishes a federal nonattainment NSR program 

tribes will be able to accept delegation to manage that

program.

Tribes in attainment, unclassifiable, and nonattainment

areas may also develop a minor New Source Review

program (minor NSR). With a minor NSR program,

enforceable emission limits are established for minor new

sources to limit the source’s potential to emit,8

 help attain

or maintain the NAAQS, and help prevent significant

deterioration of air quality. EPA is continuing to develop a

federal minor NSR rule and anticipates that it will include a

provision for delegation of the federal program to interested

tribes.

" Regional Haze Plans The purpose of regional haze plans is to improve visibility

in mandatory federal Class I areas (primarily national parks

and wilderness areas). In 1999, EPA issued regional haze

regulations that require states to work together specifically

to improve regional haze. Five regional planning
 Chapter 2 Page 30

Your tribe may wish to

develop a regional haze plan

in order to protect or

improve visibility.

organizations were established to analyze the nature and

causes of regional haze in mandatory federal Class I areas,

evaluate potential emission reduction strategies for meeting

the goals of EPA’s Regional Haze Program, and generally

facilitate the exchange of information among all

participating governments (see Appendix E, A Guide to

Regional Air Quality Planning Organizations). 

The tribe may wish to include regional haze plans as part of

its TIP if it is concerned about diminished visibility or if

sources on your reservation contribute to haze in a federal

Class I area. Tribes are encouraged to participate in these

regional planning organizations regardless of whether they

include regional haze plans in their TIPS. Participating in

the regional planning organization would help the tribe

learn about current developments in the area and allow the

tribe to coordinate your efforts with those of other

governments. Such participation will ensure tribal

positions are considered in discussions of regional air

quality for regional haze. 

What elements must

accompany a TIP?

There are three elements that must accompany a TIP when

it is submitted to EPA for approval: a request for a

determination of eligibility; administrative elements; and a

demonstration of enforcement authority. The request for a

determination of eligibility is outlined in Chapter 1, Section

“Tribal Air Programs and TIPs”. A discussion of

administrative elements9

 can be found in Chapter 6, Section

“What needs to be submitted to EPA along with your TIP?”

A discussion of enforcement authority can be found in 

Chapter 5. A sample submission checklist is provided as 

Appendix K.

Conclusion TIPs can be flexible enough to meet tribal needs while

ensuring the NAAQS are attained and maintained. Your

tribe can choose to adopt only those TIP elements that best

address its air quality needs and that it has the capability to

administer. 

Setting air quality goals and gathering data to inform those

goals is described in Chapter 3. The potential elements of a

TIP - maintenance and attainment strategies, source

preconstruction permit programs, and regional haze plans -
 Chapter 2 Page 31

1. The SIP requirements are established in the CAA section 110(a), Part C (Prevention of

Significant Deterioration), and Part D (Plan Requirements for Nonattainment Areas). 

The EPA’s SIP regulations are codified in 40 CFR parts 51 and 52.

2. The requirement that program elements be “reasonably severable” is set forth in the

Tribal Authority Rule (TAR) at 40 CFR 49.7(c). 

3. Once a TIP is approved, a tribe may be subject to sanctions when EPA determines that a

requirement of the approved TIP is not being implemented. CAA section 179(a)(4).

4. See CAA Section 110, Sections 160-169, Sections 171-192, and 40 CFR Parts 51 and 52

for identifying requirements for the preparation, adoption, and submission of

Implementation Plans.

5. The Tribal Authority Rule notices can be found at 63 Federal Register 7254, and 40 CFR

Parts 9, 35, 49, 50, and 81.

6. See Chapter 3 of this document for more information on attainment, nonattainment, and

unclassifiable air quality designations. Keep in mind that an area may be in attainment

for some pollutants and in nonattainment for others. If this is the case on your

reservation, the tribe may want to develop a maintenance strategy for some pollutants and

an attainment strategy for others.

7. In general, major sources are sources that emit over a certain amount of a pollutant (the

“major source threshold” for that pollutant); minor sources are sources that emit less than

that amount. The major source threshold can vary depending on the particular pollutant

and the air quality status of the area. For example, in an area designated attainment or

unclassifiable for a particular NAAQS, a major stationary source is defined as any source

that emits, or has the potential to emit, 250 tons per year (or, for specific types of sources,

100 tons per year) of that NAAQS pollutant subject to regulation under the CAA. 

For attainment and unclassified areas, the definitions of major source and major

modification are given in 40 CFR 51.166(b)(1) and (2), respectively. For nonattainment

areas, the definitions of major source and major modification are given in 40

CFR 51.165(a)(1)(iv) and (v), respectively. For serious PM nonattainment areas, the

definition of a major source is in the CAA section 188. For moderate, serious, severe, or

extreme ozone nonattainment areas, the definition of major source is in the CAA

are described in Chapter 4. Compliance strategies and

enforcement programs are described in Chapter 5.

Endnotes
 Chapter 2 Page 32

section 182(b), (c), (d), and (e), respectively.

8. A source’s “potential to emit” estimate is based on its maximum capacity after taking into

consideration enforceable permit conditions, such as the type of materials combusted, the

type of materials processed, and the annual hours of operation. 

9. More information on the criteria EPA uses to determine the administrative completeness

of implementation plans can be found in 40 CFR 51 Appendix V.