Chapter 4 Page 53

Chapter 4 Potential TIP Program

Elements

As previously discussed, the TAR provides tribes with the

flexibility to adopt partial TIPs, so long as the adopted

program elements are “reasonably severable” from the

program elements that are not included in the TIP.1

 Data

from emissions inventories and air quality monitoring, can

be used to determine the air quality goals and needs of your

reservation and which TIP elements, if any, your tribe may

want to adopt. Or, the tribe may choose to implement some

TIP program elements without air quality monitoring data

or an emission inventory in order to address gaps in

regulations. This chapter focuses on the potential TIP

elements that your tribe can adopt to help reach the tribe’s

air quality goals, including: 

» maintenance strategies

» attainment strategies

» source preconstruction permits

» regional haze plans 
 Chapter 4 Page 54

Maintenance

Strategies

What is a maintenance

strategy?

If your tribe has good reason to believe that existing air

pollutant concentrations on your reservation are below the

National Ambient Air Quality Standards(NAAQS) your

goal may be to develop a maintenance strategy for one or

more air pollutants.2 Your tribe may also choose to develop

a maintenance strategy for only a portion of your

reservation (instead of the entire area) if another portion has

been designated nonattainment. The goal of a maintenance

strategy is to limit air pollutant emissions so as to maintain

pollutant concentrations at levels below the NAAQS.

What are the basic steps for

developing a maintenance

strategy?

To develop a maintenance strategy, your tribe would obtain

data (including that from an emissions inventory and air

quality monitoring) and conduct analyses necessary to

accomplish the following objectives, as applicable:

» Establish enforceable emission limits

» Write enforceable regulations

» Prevent downwind NAAQS violations

» Create an appropriate compliance schedule

" Establish enforceable

emission limits

Your tribe can establish enforceable emission limits for

new and existing emission sources on your reservation. 

Most emissions limits are on equipment, although your

tribe can establish a maximum emissions level or “cap” for

a facility. To determine at what level emissions limits

should be set, ascertain the amount of emissions your tribe

could permit that would still allow the reservation to meet

its air quality goals. Your tribe may wish to consider

innovative approaches to establishing enforceable emission

limits, such as averaging and bubbling. Bubbling enables a

source to average emissions from the entire facility, while

averaging enables a source to average emissions from

several similar emission points within the facility.

The goal of a

maintenance strategy is

to limit air pollutant

emissions so as to

maintain pollutant

concentrations at levels

below the NAAQS.
 Chapter 4 Page 55

" Write enforceable

regulations

One basic purpose of regulations is to list the actions that

the owners and operators of sources must take to help

achieve your tribe’s air quality goals. To be enforceable,

regulations must be clear and specific. Regulations could

include technology-based standards and market-based

standards, which are discussed in the upcoming Attainment

strategies section - Identify appropriate control measures. 

The methods of determining compliance must be clear for

both sources and the tribal air program staff. Your tribe

also needs to adopt regulations in accordance with tribal

law and administrative procedures (see Chapter 6 for more

information) and your tribe must have the authority to

enforce the regulations (see Chapter 5 for more

information).

For many types of sources, the states and/or the

Environmental Protection Agency (EPA) have regulations

which can be used as models for your tribe’s regulations. 

The EPA has also written many guidance documents to

assist states and tribes in developing enforceable

regulations. Resources that can help your tribe write

enforceable regulations include:

» The State and Territorial Air Pollution and Program

Administrators/Association of Local Air Pollution

Control Officials (STAPPA/ALAPCO) publishes

reference guides that contain “menus of options” for

controlling various sources of pollutants

(www.4cleanair.org/).

» The EPA Office of Air and Radiation’s (OAR) Policy

and Guidance Information web site is designed to

provide access to rules, policy, and guidance documents

produced by the OAR. This site provides easy access to

both current and historical regulatory information

(www.epa.gov/ttn/oarpg/).

» The EPA’s Air Quality Office in your region can help

your tribe identify existing state and local regulations

that can serve as models for your tribe’s regulations (see

Appendix A).
 Chapter 4 Page 56

» Appendix G, TIP Enforceability Checklist, provides

general criteria that can be used to determine if

regulations are clearly written and approvable.

» Appendix J, Regulation Development

" Prevent downwind

NAAQS violations 

The Clean Air Act (CAA) section 110(a)(2)(D) prohibits

emissions from one area from negatively impacting air

quality in another area. The EPA is responsible for

resolving problems over inter-jurisdictional transport of air

pollutants. More information about EPA intervention can

be found later in this chapter under Regional Air Quality: 

Can EPA intervene in regional air quality problems?

Tribes may submit a TIP that includes enforceable emission

limits and compliance schedules 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. 

In such a case, if necessary and appropriate, EPA will

determine if the tribe’s emission limits will prevent

NAAQS violations.

" Create an appropriate

compliance schedule

If your maintenance plan establishes new emission limits, it

should also set an expeditious schedule by which sources

must comply with the regulations. The CAA generally

requires states to implement emission control programs

within 3-5 years. Some emission reductions should be

achieved each year until the regulations are fully

implemented. In addition, your maintenance plan should

include a schedule for periodic review of your emissions

inventory and modeling data, if applicable. Reviewing the

air quality data for your reservation will help your tribe

determine if your tribe is meeting your goal to maintain air

quality better than the NAAQS. 

What can be done about new

sources of emissions?

Construction of new sources on the reservation could add

enough emissions that the goals of maintaining the NAAQS

would not be met. Therefore, your tribe may also want to

adopt, as a separate TIP element, a preconstruction permit

program to review plans for new major sources of

emissions (and major modifications to existing emission
 Chapter 4 Page 57

sources) and issue permits that limit emissions from those

sources.

The Prevention of Significant Deterioration program (PSD)

is a preconstruction permit program for areas with air

quality that is better than the NAAQS. There is a federal

PSD program, which EPA administers, that applies in

Indian country. The PSD program can help your tribe

preserve good air quality while still allowing economic

development to occur. 

Under a PSD program, the tribe can require major sources

wanting to locate on your reservation to model their

projected air quality impacts at various distances from their

proposed locations (i.e., 20 km, 30 km, 40 km, 50 km). 

You can then limit emissions from the sources to reduce the

impact on the air quality.

If your tribe chooses to adopt and administer a PSD

program it will help you develop communications with

jurisdictions that border your reservation. By alerting your

neighbors of any emission increases on your reservation,

they can account for those emissions in their air quality

planning. Furthermore, by increasing communication with

surrounding jurisdictions, your tribe will be more informed

of emission changes outside its reservation that may affects

its air quality.

Your tribe can also establish a similar program to review

construction plans for minor new sources. More

information can be found later in this chapter under Source

Preconstruction Permits.

How does your tribe start

creating a maintenance

strategy?

To start creating a maintenance strategy, it may be useful to

inventory the sources, types, and quantities of air pollutants

emitted on your reservation. Your tribe may also want to

determine the current concentrations of those pollutants

relative to the NAAQS through ambient air quality

monitoring and/or modeling. In addition to the references

provided in this document, the Air Quality Program of your

regional EPA office can assist your tribe in this effort (see

Appendix A). 
 Chapter 4 Page 58

Attainment

Strategies

What is an attainment

strategy?

The existing concentrations of some pollutants on your

reservation may be above the NAAQS if there are

significant sources of air pollution on your reservation or in

adjacent areas. In those cases, or in the case where EPA

has designated your reservation as being nonattainment,

your goal may be to develop an attainment strategy to

reduce the concentrations of those pollutants to levels

below the NAAQS. Your tribe may also choose to develop

an attainment strategy for a portion of your reservation

(instead of the entire reservation) if it is appropriate.

Your tribe may decide to concentrate its efforts on

regulating the existing sources of emissions, and possibly

on regulating new sources of air pollution, as well. As your

tribe develops an attainment strategy, it should consider

how to best maintain a balance between its air quality

regulations, its economy, and its culture. The appropriate

balance will depend on the relationships between these and

other factors, and the values, goals, and priorities of your

tribe.

What are the basic steps for

developing an attainment

strategy?

To develop an attainment strategy, your tribe would obtain

the data (including that from an emissions inventory and air

quality monitoring) and conduct the analyses necessary to

accomplish the following objectives, as applicable:3

» Ascertain the effect of emissions from sources within 

and outside the TIP area

» Determine emission reductions needed to attain or

maintain the NAAQS for the pollutant(s) of concern

» Identify which emission control measures to use to

bring your area into attainment and allow it to stay in

attainment

» Write enforceable regulations that require sources to

implement emission control measures that result in

verifiable emission reductions

The goal of an attainment

strategy is to reduce the

concentrations of

pollutants to levels below

the NAAQS.
 Chapter 4 Page 59

Everglades National Park,

FL

With a rich cultural history

dating back to 10,000 B.C.,

the Everglades are the tribal

homelands of the Tequesta in

southeast Florida; the Calusa

in the southwest; and the

Jeaga and Ais along the east

coast north of the Tequesta;

and the Mayaimi, Creek, and

Seminoles near Lake

Okeechobee.

(Photo courtesy of the

National Parks Service)

» Prevent downwind NAAQS violations

» Create a schedule that sources will follow to comply

with the regulations, ensuring progress toward

attainment

» Develop “contingency measures” for situations in

which air quality improvements do not occur according

to schedule

The EPA has prepared policy memoranda related to

attainment strategies which are available at EPA’s site for

NAAQS policy and guidance memos

(www.epa.gov/ttn/oarpg/t1pgm.html). Literature in the

fields of engineering, policy analysis, and economics

discusses emission control measures for specific sources

and how to package individual measures into a

comprehensive plan. Since the Tribal Authority Rule

(TAR) allows tribes to adopt severable TIP elements and to

build a TIP in a modular fashion, your tribe may select the

requirements that meet its air quality objectives (provided

such elements are not integrally related to program

elements not included in the TIP). Your tribe should

contact the regional EPA office before submitting your TIP

(see Appendix A). The following discussion of attainment

strategies presents a general framework for planning. 

" Ascertain the effect of

emissions from sources

within and outside the

TIP area

The information in your tribe’s emission inventory on the

types and amounts of pollutants emitted by sources can be

used to determine the impacts of those sources on pollutant

concentrations on the reservation. Another reason the air

quality on your reservation may be worse than the NAAQS

is air pollution from nearby, non-reservation sources being

transported across your reservation boundaries. Sources of

pollutants outside the TIP area may be a concern if your

reservation is adjacent to or surrounded by a state

nonattainment area, or if it is downwind of major sources of

emissions that are not under your tribe’s jurisdiction.

Your tribe may want to ascertain the potential effects that

pollutants from sources outside the TIP area have on your

reservation’s air quality. Therefore, an appropriate air
 Chapter 4 Page 60

quality model, as recommended in EPA’s Guideline on Air

Quality Models,4 can be used to estimate the effects of

emissions from those sources and activities, located both on

and off the reservation, on the reservation’s air quality. The

modeled pollutant concentrations, when added to an overall

background (natural) pollutant levels on the reservation,

gives an estimate of the total concentration of each

pollutant. The effects of emissions from sources located

off the reservation on total pollutant concentrations can be

estimated by running the model with only those sources,

and separately running the model with sources located on

the reservation.

Some pollutants, such as ozone and fine particulate matter,

are not emitted directly from a source, but rather are formed

in the atmosphere through chemical reactions with

emissions from many sources over a large area. These

secondary pollutants are regional in nature and

consequently are inappropriate for the type of analysis

described above.

Your tribe can only regulate sources within its jurisdiction. 

However, if your tribe determines that emissions from

sources outside the TIP area are causing your reservation’s

air quality to exceed the NAAQS, or if your tribe worries

that such emissions may cause future air quality problems

on your reservation, there are steps your tribe can take. For

more information, see the section on Regional Air Quality

later in this chapter. Your tribe can also approach the

regional office for assistance in making these assessments.

" Determine the necessary

emission reductions

To determine the emission reductions needed from sources

on your reservation, the monitoring data your tribe collects

must be compared to the NAAQS. To make this

comparison, your tribe needs to calculate the “design value”

for each pollutant of concern. The design value is the

monitoring data in the same form and over the same

averaging period as the NAAQS. The method for

calculating the design value depends upon the units and

averaging time of the NAAQS.5

 Your tribe should follow

EPA’s data handling conventions and computational

formulas when determining design values. More

information on the data analysis requirements can be found
 Chapter 4 Page 61

Sources outside your TIP

area, such as this industrial

complex, may transport

pollutants onto your TIP

area.

Control measures may be

technology-based or

market-based.

in the Code of Federal Regulations (CFR) at 40 CFR 50

(accessible at www.access.gpo.gov/nara/cfr/ index.html).

If the design value for a pollutant is greater than the

NAAQS, the area violates the NAAQS for that pollutant. 

For example, the NAAQS for carbon monoxide (CO)

is 9 parts per million (ppm) for an 8-hour average

concentration. If the design value for CO on your

reservation is 10 ppm, it indicates that the concentration of

CO in the ambient air exceeds the NAAQS and your design

value must be reduced by at least 1 ppm or ten percent.

To reduce the ambient concentration of CO, your tribe

could: (1) reduce the CO emissions by a fixed amount

(about 10 percent) from every source in your emission

inventory; or (2) reduce the CO emissions from different

sources by different amounts (based on the cost

effectiveness of control options or other factors important

to your tribe). For the latter strategy, your tribe could use

air quality modeling to test different combinations of

reductions before deciding which combination to use. 

Some pollutants, such as ozone, are formed from more than

one precursor pollutant through complicated atmospheric

chemistry; these pollutants would require more complex

strategies to determine which precursor pollutant emissions

to reduce, by how much, and from which sources.

" Identify appropriate

control measures

The hurdle that proposed control measures must clear is

whether, taken as a group, they can achieve the emission

reductions necessary to decrease pollutant concentrations

by the amount indicated by the design value (see above).6

A fundamental choice that your tribe will make when

selecting control measures is whether it will adopt a

technology-based or a market-based strategy. 

With a technology-based strategy, your tribe would

require a process change or an emission limitation for a

piece of equipment or process. For example, your tribe

might set the maximum allowable sulfur dioxide emission

rate from a process; set the maximum allowable volatile

organic compound content allowed in coatings (such as

those used in the manufacturing wood products); require
 Chapter 4 Page 62

Nez Perce National

Historical Park, ID

For thousands of years the

valleys, prairies, mountains

and plateaus of the inland

northwest have been home to

the Nez Perce people. The

park also houses the

battlefield from the War of

1877, where the Nez Perce

people fought the U.S. Army.

(National Parks Service)

work practices such as wetting dry, dusty materials at

construction sites to reduce particulate matter emissions; or

require the installation of a certain pollution control device

for reducing emissions. These measures are technologybased.

If your tribe prescribes emission limitations or emissionreducing actions for each source or category of sources,

regulations must require the use of Reasonably Available

Control Technologies (RACT) or Reasonably Available

Control Measures (RACM).7

 RACT is typically for large

point sources such as industrial facilities, while RACM is

for area sources such as agricultural operations.

The EPA has many resources to provide guidance for the

selection of appropriate control measures. The Clean Air

Technology Center (CATC) is a resource on all areas of

emerging and existing air pollution prevention and control

technologies, and provides public access to information on

their use, effectiveness, and cost. In addition, the CATC

will provide support, as resources allow, related to the

technical and economic feasibility, operation, and

maintenance of these technologies. The

RACT/BACT/LAER Clearinghouse within the CATC

contains information from state and local air pollution

control agencies that can be used in determining what types

of controls and pollution prevention measures have been

applied to and/or are required for various sources, the

effectiveness of these technologies, and the annualized cost

of purchase, operation, and maintenance.8

 More

information on the CATC is available at

www.epa.gov/ttn/catc/. 

A market-based strategy, or economic incentive program,

achieves air quality objectives by providing market-based

incentives or information to emission sources.9

 There are

four main types of economic incentive programs:

» Emission trading programs limit the total emissions

from a certain type or group of sources and allow the

sources to trade or buy emission credits to comply with

their individual emission limits
 Chapter 4 Page 63

The selection of control

measures depends on

several factors, including:

 • Number and types of

sources

 • Pollutants to be

reduced

 • Expertise, experience,

and number of air

program staff

 • Effectiveness, cost

and fairness of

various control

measures

» Financial mechanism programs include fees paid by

emitters for each unit of emissions, or subsidies that

promote pollution-reducing activities or products

» Clean air investment funds allow sources with high

costs for reducing emissions to pay into a fund instead;

the funds are then used by the regulatory authority to

procure emission reductions elsewhere

» Public information programs include educational

programs, product certifications, “ozone action days,”

and other information people can consider when

making choices that affect air quality

A market-based strategy is most successful when several

large sources that continuously monitor emissions

participate. Your tribe may consider requiring certain

sources to join an existing regional market-based trading

program to achieve emission reductions. Guidance on

developing an economic incentive program can be found in

Improving Air Quality with Economic Incentive Programs

(EPA-452/R-01-001, January 2001), available at

www.epa.gov/ttn/oarpg/t1main.html and through EPA’s

Air and Radiation Docket and Information Center (Docket

Number A-97-27) by calling (202) 260-7548.

The best regulatory approach for your tribe depends on the

number and types of sources your tribe is regulating, the

pollutants to be reduced, the expertise, experience, and

number of your air program’s staff, and other

considerations. Your situation is likely to be different from

that of other tribes. If your tribe chooses a technologybased approach, it will restrict the flexibility that sources

have in complying, but it will create a program that is

relatively easy to implement. If your tribe chooses a

market-based approach, it will provide maximum

compliance flexibility (which may reduce the total cost of

compliance for sources), but will create a more complicated

system to implement.

Only careful investigation of the options for limiting

emissions from the sources under your jurisdiction will tell

which control measures are best for your tribe. Because
 Chapter 4 Page 64

“best” could mean several things, another important part of

the air quality planning process is to explicitly state the

criteria that your tribe will use to select control measures. 

Criteria may include effectiveness, cost, and fairness.

Questions to ask when selecting control measures include: 

» How well does the method reduce emissions?

» How certain are the reductions using the method?

» Are the reductions sufficient to ensure the source is not

causing an air quality violation downwind?

» What is the total cost? Cost per ton of pollution

reduced? Up-front capital cost? Annual operating and

maintenance cost?

" Write enforceable

regulations

As discussed above under Maintenance Strategies,

regulations must be clear and specific and the methods of

determining compliance must be clear for both sources and

the tribe’s air program staff. Regulations need to be written

in accordance with tribal law and administrative procedures

(see Chapter 6 for more information) and your tribe must

have the authority to enforce the regulations (see Chapter 5

for more information).

For many types of sources, the states and/or the

Environmental Protection Agency (EPA) have developed

many resources and guidance documents to assist in

developing enforceable regulations. In addition, Appendix

G, TIP Enforceability Checklist, provides general criteria

that can be used to determine if regulations are clearly

written and approvable and Appendix J, Regulation

Development provides useful information.

" Prevent downwind

NAAQS violations

The Clean Air Act (CAA) section 110(a)(2)(D) prohibits

emissions from one area from negatively impacting air

quality in another area. The EPA is responsible for

resolving problems over inter-jurisdictional transport of air

pollutants. More information about EPA intervention can

be found later in this chapter under Regional Air Quality: 

Can EPA intervene in regional air quality problems?

Tribes may submit a TIP that includes enforceable emission

limits and compliance schedules and not include evidence

that the emission limits are adequate to prevent NAAQS
 Chapter 4 Page 65

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. 

In such a case, if necessary and appropriate, EPA will

determine if the tribe’s emission limits will prevent

NAAQS violations.

" Create an appropriate

schedule for emission

reductions

Your attainment strategy should include a schedule by

which sources must comply with regulations. The

compliance date should allow the sources to comply

without great economic difficulty and ensure attainment of

the NAAQS as soon as possible. The CAA generally

requires states to implement attainment strategies within

five years of less

Your tribe may want your schedule to ensure that

reasonable further progress (RFP) is made in annual

emission reductions. RFP, or annual incremental emission

reductions, are required for state nonattainment areas. To

make RFP, some emission reductions should be achieved

each year (i.e., new regulations take effect of new sources

must comply each year) until the attainment strategy is fully

implemented. 

Your tribe may or may not decide to demonstrate RFP

through the schedule you develop. However, when tribal

lands are part of a multi-state jurisdictional area, if the tribe

does not show that the emission limits in their TIP are

adequate to prevent NAAQS violations and make RFP,

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.

" Develop appropriate

contingency measures

The tribe should discuss with the regional office the need

for including contingency measures in the TIP. 

Contingency measures should accomplish about 1 year’s

worth of progress toward meeting the NAAQS, or an

additional 20 to 25 percent of the emissions being
 Chapter 4 Page 66

reduced.10 For example, if emissions must be reduced 100

tons per year to attain the NAAQS, contingency measures

should be capable of reducing emissions by an additional

20 to 25 tons per year. Your tribe should also establish

criteria for determining when and if the contingency

measures have to be implemented, and set a schedule for

implementing them, if needed. If your tribe does not

include contingency measures in their TIP, EPA will adopt

additional measures to fill the gap, where necessary and

appropriate.

What can be done about new

sources of emissions?

Construction of new sources on the reservation could add

enough emissions that the goal of the TIP to attain and

maintain the NAAQS would not be met. Therefore, the

tribe may also want to include source preconstruction

permit programs as a seperate TIP element in their TIP. 

The program, applicable to areas with air quality that is

worse than the NAAQS, is a nonattainment New Source

Review (NSR) program. You can limit the impacts of

emissions from new major sources and major modifications

to existing sources with a NSR program. Tribes can also

establish a similar program to review construction plans for

new minor sources. For more information, see the Source

Preconstruction Permits section later in this chapter.

How does your tribe start

creating an attainment

strategy?

To start developing an attainment strategy, your tribe will

need to determine the emission reductions necessary to

attain and maintain the NAAQS for the pollutant(s) of

concern. Your tribe will also need to identify the sources of

air pollution that need to be controlled and the emission

control measures your tribe wants to require to achieve

these emission reductions. Your tribe’s attainment strategy

may include adopting a source preconstruction permitting

program and creating a mandatory schedule for sources to

implement emission control measures. Contingency

measures for situations in which emission reductions do not

occur according to schedule are another element your tribe

can include in an attainment strategy. In addition to the

references provided in this document, the Air Quality

Program of your regional EPA office can also provide

guidance as your tribe creates an attainment strategy (see

Appendix A). 
 Chapter 4 Page 67

Source

Preconstruction

Permits

What is New Source

Review?

Reviewing plans for a

proposed new source.

The New Source Review (NSR) program requires all new

major sources or existing sources with major modifications

in both nonattainment areas and attainment areas to obtain

preconstruction permits.11 The definition of major

stationary source and major modification varies with the air

quality status of the area and the type of pollutant.12 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. A major modification means any physical change

in or change in the method of operation of a major

stationary source that would result in a significant net

emissions increase of any pollutant subject to regulation

under the CAA.13

For example, in attainment and unclassifiable areas, a

major stationary source is defined as any source that emits,

or has the potential to emit,14 250 tons per year (or, for

specific types of sources, 100 tons per year) of any pollutant

subject to regulation under the CAA. Serious particulate

matter nonattainment areas and moderate, serious, severe,

and extreme ozone nonattainment areas have lower

thresholds for determining what is a major source. 

The NSR permit requirements are determined on a case-bycase basis. The permits specify emission limits and control

requirements for each emission point at a source, as well as

the monitoring, recordkeeping, and reporting requirements. 

The CAA created three separate NSR programs to address

different situations involving new and growing facilities

(see Table 4-1). 
 Chapter 4 Page 68

If your tribe does not

adopt a major NSR

program, the EPA may

adopt, without

unreasonable delay,

Federal Implementation

Plan provisions as are

necessary or appropriate

to protect air quality.

Table 4-1. Overview of the New Source Review Programs

Program Name Program

Abbreviation

Applicable

Areas Applicable Sources

Nonattainment

New Source

Review

nonattainment

NSR

Nonattainment New major sources

Existing major sources with 

 major modifications

Prevention of

Significant

Deterioration

PSD Attainment,

Unclassifiable

New major sources

Existing major sources with 

 major modifications

Minor 

New Source

Review

minor NSR Nonattainment,

Attainment,

Unclassifiable

New minor sources

Any modification to minor 

 sources

Minor modifications to 

 major stationary sources

The nonattainment NSR and PSD programs, collectively

known as major NSR, are federal regulations under the

CAA. Implementation of the federal NSR programs can be

delegated to individual states and tribes. A tribe should

contact the Regional Office is it wishes to have such

programs delegated. If a source wants to locate in Indian

Country, and your tribe has not or does not want to adopt a

major NSR program, EPA would do a source-specific FIP. 

Minor NSR programs are state, local, and tribal programs

that apply to sources smaller than those in the major NSR

programs. EPA is in the process of developing these

programs.

Both the major and minor new source review programs

focus primarily on the criteria pollutants (ozone, nitrogen

dioxide, lead, carbon monoxide, sulfur dioxide, and

particulate matter) regulated by the NAAQS. State minor

NSR programs frequently cover additional pollutants,

including many toxic air pollutants, which are not covered

in their SIPs.

The core procedures in the major NSR programs are: (a)

evaluating the consequences of allowing facilities to start
 Chapter 4 Page 69

The nonattainment NSR

program deals with large

point sources such as this

petroleum refinery.

operations or to expand; (b) requiring the most effective

emissions control measures for these facilities; and (c)

including informed public participation in the evaluation of

consequences and selection of emissions control measures. 

These procedures must occur before the construction or

expansion of a facility begins. 

If emissions from a new major source or major

modification may affect a national park or wilderness area,

the evaluation may also include the impact of emissions on

visibility and natural and cultural resources in the park or

wilderness area. Federal land managers can assist with this

effort. For lands owned by the government of the United

States, a federal land manager is the representative of the

department or agency with authority over such land, such as

a Regional Forester or individual Forest Supervisor for US

Forest Service lands.

What is the nonattainment 

NSR program?

Numerous requirements in the CAA apply to new major

sources and major modifications at existing sources in

nonattainment areas. For example, a facility covered by

nonattainment NSR must install control equipment

ensuring the Lowest Achievable Emission Rate (LAER). 

The economic costs are not considered when defining the

applicable control technology to obtain LAER. The LAER

is defined as the more stringent of the following limitations: 

» The most stringent emission limitation contained in a

SIP of any state for the same class or category of source

(unless it is demonstrated that this limitation is

unachievable)

» The most stringent emission limitation achieved in

practice

Another requirement of the nonattainment NSR program is

that increases in emissions from new major sources and

major modifications must be matched or offset by greater

emissions reductions from other sources (called “offsets”),

thus ensuring that progress is made toward decreasing the

total emissions for the area and meeting the NAAQS.15
 Chapter 4 Page 70

Nonattainment NSR programs must meet all the

requirements established in the Code of Federal

Regulations (CFR) at 40 CFR 51.160-165, and Part D of

the CAA. State air regulators have developed

nonattainment NSR programs which tribes can use as

models when developing their own programs. Your

regional EPA office can also provide assistance and

guidance (see Appendix A, Tribal Contacts at EPA). The

EPA is developing an example nonattainment NSR

program. Once it is promulgated, your tribe will be able to

adopt it by reference. NSR guidance documents are

available from EPA at www.epa.gov/ttn/nsr/.

What is the PSD permitting

program?

The purpose of the Prevention of Signification

Deterioration (PSD) permitting program is to prevent air

quality that is below the NAAQS from deteriorating more

than an incremental amount. If the air quality on your

reservation is currently better than the NAAQS, your tribe

may want to adopt a PSD permitting program which would

allow for air quality goals more protective than the

NAAQS. The PSD permitting program applies to all new

major sources or major modifications of existing major

sources in attainment and unclassifiable areas. With a PSD

program, your tribal permitting authority can require the

best available air pollution control technology (BACT) to

be installed when large new sources are constructed or

expanded. BACT is defined as an emission limitation

based on the maximum degree of reduction of each

pollutant [subject to regulation under the PSD program]

which your permitting authority determines is achievable

through application of production processes and available

methods, systems and techniques. BACT is to be

determined for each source on a case-by-case basis, taking

into account energy, environmental, and economic impacts

and other costs. [See section 169(3) of the Clean Air Act.]

The PSD permitting process typically takes from 3 months

to 1 year. However, complicated or controversial permits

can take longer. In order to obtain a permit, a source and

the permitting authority must do the following: 
 Chapter 4 Page 71

Yosemite National Park,

California

Indian people have lived in

the Yosemite region for as

long as 8,000 years. By the

mid-nineteenth century, when

native residents had their first

contact with non-Indian

people, they were primarily

of Southern Miwok ancestry. 

However, trade with the

Mono Paiutes from the east

side of the Sierra for pinyon

pine nuts, obsidian, and other

materials from the Mono

Basin resulted in many

unions between the two

tribes.

» Evaluate the BACT, which is based on the most

stringent control available for a similar type of source

that is technically and economically feasible

» Perform an ambient air impact study

» Conduct additional impact studies including visibility,

soils, and vegetation

Under the PSD permitting program, the “baseline”

concentration of regulated pollutants must be determined. 

The baseline is the ambient concentration level of a

pollutant that exists at the time of the first application for a

PSD permit in the baseline area. The baseline

concentration can be determined using existing data

representative of air quality in the area where the new

source will be located. If representative data do not exist,

your permitting authority can require the permit applicant

to establish a site-specific monitoring network, and monitor

the air quality for a period of at least one year immediately

before applying for a permit to construct. Your permitting

authority can also require the permit application to monitor

the meteorological parameters of the area to facilitate

modeling the potential impacts of emissions from the new

source.

The ambient concentration resulting from total emissions

from all sources (both permitted and non-permitted

sources) is not allowed to exceed the baseline plus an

increment set in the CAA and in EPA’s regulations.16

Owners of new and growing facilities must show how

much the increase in emissions will increase the

concentrations of air pollutants in Indian country. The total

effect of the increased emissions from new and modified

sources on pollutant concentrations may not exceed the

baseline plus the increment, nor exceed the NAAQS. In

most cases, the baseline plus the increment will result in an

emissions ceiling more stringent than the NAAQS (see

Figures 4-1 and 4-2).
 Chapter 4 Page 72

Figure 4-1. PSD Program: Baseline + Increment = Ambient Standards More

Stringent Than NAAQS.

Under the PSD Program, the maximum allowable ambient concentration equals

the baseline plus the increment. Therefore, standards can be more stringent than

the NAAQS.

Figure 4-2. PSD Program: NAAQS Remain Maximum Emission Level

There could be cases where the baseline plus the increment would exceed the

NAAQS. However, the NAAQS are a ceiling that ambient concentrations are

NOT allowed to exceed.
 Chapter 4 Page 73

The increments are

smallest for Class I areas

and largest for Class III

areas. Only very little

degradation of air quality

is allowed in Class I

areas. 

The increments are smallest for Class I areas and largest for

Class III areas (attainment area classifications are discussed

in Chapter 3).16 Therefore, Class I areas (which include

national parks, national wilderness areas, national

monuments, national seashores, other areas of special

natural, recreational, scenic, or historic value, and areas

reclassified as Class I) receive the greatest protection. Only

very little degradation of air quality is allowed in Class I

areas. To permit a major new facility or major

modification of an existing facility in a Class I area, an

offset from another facility in the area may be necessary. 

Apart from your tribe’s decision whether to adopt your own

PSD program, your tribe has some freedom to change the

classification of your reservation and thus affect the amount

of allowable emissions growth from new and growing

facilities. The CAA automatically classifies most

attainment areas as Class II, but a federally recognized

Indian tribe may apply to change the classification of its

reservation to Class I or Class III.17 Reservations that have

been reclassified from Class II to Class I include those of

the Northern Cheyenne, Flathead, Fort Peck, Spokane, and

Yavapai-Apache Indians.

Your tribe’s governing body can request reclassification by

submitting a proposal to the EPA, notifying the appropriate

state(s), and holding a public hearing. See Appendix H

(Procedures for Area Reclassification to Class I) and the

CAA section 164 for more detailed information on the

statutory and regulatory requirements for redesignation. 

The EPA has developed a PSD permitting program. The

EPA must administer the PSD permitting program in any

state or reservation that has not developed its own PSD

permitting program or received a delegation of authority

from the EPA to implement the federal program. Your

tribe may request delegation of PSD administration if it has

the technical knowledge and legal authority to implement

and enforce the requirements. Alternatively, your tribe can

develop your own PSD permitting program and submit it as

part of your TIP. One way your tribe can establish a PSD

permitting program is to incorporate the federal PSD

permitting program by reference into your TIP (this process
 Chapter 4 Page 74

is different than delegation).18 The federal PSD permitting

requirements and the requirements that state and tribal PSD

permitting programs must meet are found at 40 CFR

51.165(b), 51.166 and 52.21. 

What is minor NSR? Minor NSR programs can be developed in both attainment

and nonattainment areas and apply to smaller new facilities

and facility expansions that are not large enough to qualify

as major new sources or major modifications. Examples of

common minor sources include gasoline stations,

automobile refinishing shops, dry cleaners, incinerators,

and small industrial facilities. A minor NSR program

allows a state or tribe to exercise oversight over the growth

of pollution from minor sources to ensure such sources will

not cause or contribute to a violation of the NAAQS, while

still allowing growth to occur. 

A minor NSR program can also provide permitting

flexibility. In minor NSR, a source with a potential to emit

above the major source threshold can agree to enforceable

emissions limits below the major source threshold. The

source would not be required to undergo the more complex

major NSR and lower emissions would be ensured. Such a

source is called a “synthetic minor” source. 

There is no federal minor NSR program and the CAA is not

specific on what is required in such a program. Therefore,

states and tribes currently have flexibility when designing

these programs. Existing minor NSR programs vary

greatly, and can differ in attainment and nonattainment

areas. Typically the programs require emission limitations

and monitoring, recordkeeping, and reporting to ensure

compliance with the emission limits. State air regulators

have developed minor NSR programs. Your tribe may

want to consider using a state’s minor NSR program as a

model when developing its own minor NSR rules. 

How does your tribe start

creating a preconstruction

permit program?

Your emissions inventory will help your tribe identify the

types of sources a preconstruction permit program on your

reservation will need to regulate. Information on

permitting can be found in the references provided in this

document. In addition, the EPA tribal air coordinator for

your region can help your tribe determine which, if any,
 Chapter 4 Page 75

Testing visibility with an

IMPROVE monitor.17 

This is an Optec LPV-2

transmissometer, with the

transmitter end of the

instrument on a rooftop in

Denver, Colorado. It’s

corresponding receiver end is

located on another rooftop a

distance away. (Air

Resources Specialists, Inc.)

existing NSR or minor NSR programs may be useful

models for your tribe to use, and assist your tribe in the

development of its preconstruction permit program

(Appendix A).

Regional Air

Quality

Why is regional air quality

important? 

According to the CAA section 110(a)(2)(D), emissions

from one area are not supposed to negatively impact

another area’s air quality. Sources are not allowed to:

» Contribute significantly to nonattainment in other areas

» Interfere with maintenance of the NAAQS in another

area

» Interfere with measures implementing prevention of

significant deterioration in other areas

» Interfere with measures protecting visibility in other

areas

However, pollutants such as sulfur dioxide, nitrogen

oxides, ozone, and fine particulate matter can travel great

distances from the source. Therefore, urban and rural areas

working to reduce ozone may be fighting a losing battle if

upwind sources release pollutants that travel in their

direction. Regionally, tribal and state governments,

businesses, citizens, and EPA and other federal agencies

need to work together to help overcome this problem. In

fact, it may be less expensive and more fair to control

emissions throughout a region rather than just in the

nonattainment areas. 

Sophisticated computer modeling of a region including

your reservation - and possibly multiple surrounding

states - can be used to evaluate the impacts upwind sources

have on your reservation, and the impacts sources on your

reservation have on downwind areas. Atmospheric

transformation and dispersion models that are used

regularly for these investigations include the Regulatory

Emission Modeling System for Aerosols and Deposition

(REMSAD) and the Urban Airshed Model-V (UAM-V).19

REMSAD calculates concentrations of particulate matter
 Chapter 4 Page 76

A clear day...

... and a hazy day at Glacier

National Park, MT.

and UAM-V calculates concentrations of ground-level

ozone. Dispersion models are helpful when developing

emission control strategies because they relate changes in

emissions to changes in air pollutant concentrations.

Two options your tribe has for addressing regional air

quality are: participating in regional planning to develop a

regional haze plan; and petitioning EPA for intervention if

your tribe believes upwind sources are contributing to

nonattainment on your reservation.

What is haze? Regional haze affects public welfare such as the quality of

life in the places where we live, work, and play. Haze

obscures the clarity, color, texture, and form of what we

see. Regional haze plans can be included as elements of 

TIPs.

Haze is caused when light encounters tiny pollution

particles (sulfates, nitrates, organic carbon, soot, and soil

dust) and some gases (nitrogen dioxide) in the air. Some

light is absorbed by the particles and gases and other light is

scattered away before it reaches an observer. More

pollutants mean more absorption and scattering of light,

resulting in more haze. Humidity (especially prevalent in

the east) magnifies the haze problem because some

particles, such as sulfates, attract water and grow in size,

scattering more light. 

Some of the same pollutants for which NAAQS have been

established because of their serious health and

environmental effects also contribute to regional haze. 

Some haze-causing pollutants (mostly fine particles) are

directly emitted to the atmosphere by a number of

activities, such as electric power generation, various

industrial and manufacturing processes, truck and auto

emissions, burning related to forestry and agriculture, and

construction activities. Others are formed when gases are

emitted to the air and form particles as they are carried

downwind (such as sulfate, formed from sulfur dioxide, and

nitrates, formed from NOX). Natural sources, such as forest

fires, windblown dust, and organic emissions from

biogenic sources also contribute to haze.20 Particles in the

air can travel hundreds or thousands of miles, contributing
 Chapter 4 Page 77

This dirt is from a recently

developed sub-division in

Lame Deer, MT. It will

eventually be washed down

to a busy street and, when it

dries and gets blown by

traffic and wind, will

contribute to a PM problem.

to the haze that causes visibility impairment over broad

regions of the United States. This distribution makes

regional efforts for addressing haze a necessity.

What has the EPA done to

improve and protect

visibility?

The EPA issued regional haze regulations in 1999 (the

“Regional Haze Rule”) that call for states and tribes, in

partnership, to establish goals for improving visibility and

to develop long-term strategies to return visibility to natural

conditions in federal Class I areas (primarily national parks

and wilderness areas). The EPA’s Regional Haze Program

applies to all states and to tribes that are eligible to

implement CAA programs. They are to address their

contributions to visibility problems in national parks and

wilderness areas both within and outside their borders. 

Most initial plans for implementing the regional haze

program are due in 2008. However, nine states and the

tribes located in the western portion of the country have the

option of submitting plans in 2003 to improve visibility in

16 Class I areas on the Colorado Plateau. Progress reviews

are due every five years, and comprehensive plan revisions

are due in 2018 and every ten years thereafter. The regional

haze regulations also call for coordinated efforts between

the states and eligible tribes to meet particulate matter

health standards. 

How can your tribe 

improve and protect

visibility?

Your tribe can improve and protect visibility by developing

a regional haze plan. These regional haze plans, part of the

EPA’s Regional Haze Program, are discussed below. 

Because these plans are regional is scope, The EPA is

encouraging states and tribes to work in regional groups to

develop and implement their air quality plans. Five

regional planning organizations (RPOs) covering the 48

contiguous states have been established to analyze the

nature and causes of regional haze in each federal Class I

area (see Appendix E, A Guide to Regional Air Quality

Planning Organizations). These organizations will also

work together to evaluate potential emission reduction

strategies for meeting the goals of EPA’s Regional Haze

Program.21 The RPOs will explore ideas for meeting

regional haze program goals, perform technical analyses,

and generally facilitate the exchange of information among

all participating governments. The EPA is encouraging the

RPO’s to develop recommended strategies and agree on
 Chapter 4 Page 78

acceptable methodologies for apportioning emission

reduction responsibilities to state and tribal governments. 

States and tribes then implement these strategies through

individual state or tribal regulations. The regional haze rule

provides flexibility for states and tribes to develop a range

of strategies addressing stationary, mobile, and area

sources.

" Regional Planning

Organizations

A tribe that wishes to include a regional haze plan as part of

their TIP, or that is interested in regional air quality issues

in general, should participate in the regional planning

organization for its area. The RPOs are primarily

partnerships between state and tribal governments as air

quality regulators in various geographic areas of the

country, although these organizations want participation

from all interested parties. 

There are a number of benefits for tribes in participating in

the RPOs: (1) participation helps build a tribe’s capability

to manage it’s air quality; (2) participation helps build

working relationships with other air quality professionals;

(3) participation can help a tribe leverage monitoring,

modelling and other technical resources; (4) in the future,

the RPOs may address other long-range transport issues

such as transport of ozone, fine particulate matter and toxic

air pollutants; and (5) tribes can contribute to the RPOs by

providing fresh ideas, monitoring visibility on their

reservations, and filling gaps in emission regulations (even

small quantities of emissions can affect regional haze).

When participating in a regional planning effort, your tribe

may wish to advocate for the tribe’s interests in air quality

on its reservation. You may wish to articulate the tribe’s

positions on issues, and ensure that studies of the potential

impacts of new regulations assess the air quality benefits

and economic costs for your tribe, as well as other

implications, such as effects on the quality of life on your

tribe’s reservation.

When identifying problems and developing solutions, it is

important that every participant in the regional planning

effort use consistent methods for counting sources,

developing emissions inventories, and considering other
 Chapter 4 Page 79

factors, such as environmental costs and benefits. With this

information, the group should develop a plan for

implementing the recommendations it develops. 

" Regional Haze Plans Regional planning organizations are working together to

develop regional haze plans. Regional haze plans include

goals for improving visibility in national parks and

wilderness areas and to develop long-term strategies for

reducing emissions of air pollutants that cause visibility

impairment. These goals should show reasonable progress

goals based on improving visibility in the Class I affected

area on the haziest day, as well as not allowing degradation

of visibility on clear days. The long-term strategies should

include enforceable measures allowing your tribe to meet

the goal. It will be helpful to identify all manmade

emissions contributing to impaired visibility in the Class I

areas, and then identify the emission reduction measures

your tribe will require. It may be the case that visibility

will improve with the implementation of programs

designed to meet the national ambient air quality standards

for particulate matter.

An example of collaboration

to address regional haze

One regional planning group that developed a regional haze

strategy is the Grand Canyon Visibility Transport

Commission (GCVTC). The GCVTC was established by

Congress through the 1990 CAA Amendments to address

visual air quality in the national parks and wilderness areas

on the Colorado Plateau. The GCVTC was comprised of

tribal, state, and federal representatives. Many of the

GCVTC recommendations were incorporated into section

51.309 of the regional haze rule. Section 51.309 outlines

an optional approach for the states and tribes in a nine-State

western region to submit regional haze plans in 2003. 

Examples of some of the emission reduction strategies

included in section 51.309 are:

» Regional sulfur dioxide emissions milestones for

each year in the 2003-2018 period, and a backstop

market trading program to be implemented if any

milestone is exceeded.

» Mobile source emissions caps for areas contributing

significantly to visibility impairment.
 Chapter 4 Page 80

Grand Canyon National

Park, Arizona

The Grand Canyon National

Park has a long history of

tribal culture, namely with

the Pueblo tribes. About

2,000 ancestral Puebloan

sites have been found within

the park boundaries. The

Grand Canyon also houses

the homelands of the Cerbat,

Navajo, and Apache tribes. 

(Photo courtesy of the

American Park Network)

» Smoke management plans and annual fire emissions

goals for prescribed fire programs

» Comprehensive emissions tracking strategies for

clean air corridors to ensure that visibility does not

degrade on the cleanest “least impaired” days.

» Programs to expand energy conservation and to

provide incentives for early emissions reductions.

Once the GCVTC made its recommendations, the Western

Regional Air Partnership (WRAP) was formed to

implement GCVTC’s recommendations. The WRAP’s

goals are to “promote and monitor the implementation of

the recommendations from the GCVTC and, with the

concurrence of its members, engage in other common

regional air quality issues.” 

The members of WRAP include governors from western

states, western tribal leaders, and representatives of the

Departments of Agriculture and Interior, and EPA. Tribal

representation includes the Pueblo of Acoma, the Campo

Band of Kumeyaay Indians, the Cortina Indian Rancheria,

the Hopi Tribe, the Hualapai Nation of the Grand Canyon,

the Northern Cheyenne Tribe, the Salish and Kootenai

Confederated Tribes, the Pueblo of San Felipe, the Nez

Perce Tribe, and the Shoshone-Bannock Tribes of Fort

Hall. Tribal air professionals are in many of the

workgroups and committees. For more information on the

WRAP, visit their web site at www.wrapair.org, or contact

the National Tribal Environmental Council at (505) 242-

2175.

Can EPA intervene in

regional air quality

problems?

Section 126 of the CAA requires certain new major sources

and major modifications to provide written notice to all

nearby states and eligible tribes that may be affected by

their emissions before they can be built. Sources that must

comply with this requirement are those either subject to a

PSD program, or that may significantly contribute to levels

of air pollution above the NAAQS in another region. 

This section of the CAA also authorizes a downwind

jurisdiction to petition EPA to impose emission limits

directly on upwind sources if emissions from those sources

are found to adversely affect that jurisdiction.22 (A tribe
 Chapter 4 Page 81

1. “Reasonably severable” means that the TIP elements selected are not integrally related to

the elements that are not included in the TIP and are consistent with applicable CAA and

making an appeal must be eligible for treatment in the same

manner as a state.) In 1997, eight northeastern states filed

petitions requesting EPA to make a finding that nitrogen

oxide (NOX) emissions from certain major stationary

sources significantly contribute to ozone nonattainment

problems in the petitioning states. The eight petitioning

states were Connecticut, Maine, Massachusetts, New

Hampshire, New York, Pennsylvania, Rhode Island, and

Vermont. The petitions identified 30 states and the District

of Columbia as containing sources that significantly

contribute to regional transportation of ozone to the

northeast. 

In December 1999, after a technical review and public

comment period, EPA granted the section 126 petitions

from four northeast states (Connecticut, Massachusetts,

New York, and Pennsylvania), finding that certain large

electric utilities, industrial boilers, and turbines violated the

CAA prohibition against significantly contributing to air

pollution in other states. The petitions of the other four

states were denied because by that time, all areas in those

states met the 1-hour NAAQS for ozone. As a result of

these findings, EPA is directly regulating the offending

sources by applying the necessary emissions limits, and

requiring each affected facility to participate in a federal

NOX “cap-and-trade” emissions trading program. A total of

392 facilities affected by these petitions will have to reduce

annual emissions of NOX by a total of nearly 510,000 tons. 

Conclusion There are several potential TIP elements that your tribe can

adopt to help it reach its air quality goals: maintenance

strategies, attainment strategies, source preconstruction

permits, and regional haze plans. Once your tribe has

decided which TIP elements, if any, to adopt, it can begin

developing its TIP. Chapter 5 addresses two important

aspects of TIP development: source compliance and

enforcement of regulations.

Endnotes
 Chapter 4 Page 82

regulatory requirements. 40 CFR Part 49.7(c)

2. The CAA Section dealing with maintenance plans is Section 110(a)(1). Maintenance

strategies for areas previously in nonattainment are established in the CAA section 175A. 

3. Sections 171 through 193 of the CAA establish the requirements for attainment plans.

4. The EPA’s Guidelines on Air Quality Models can be found at 40 CFR Part 51, Appendix

W and on-line at www.epa.gov/ttn/scram

5. Information on the data analysis requirements can be found in 40 CFR 50 and at the

NAAQS policy and guidance memos site (www.epa.gov/ttn/oarpg/t1pgm.html).

6. Resources provided in this section for developing control measures include:

» The Clean Air Technology Center (CATC) is a resource on emerging and existing air

pollution prevention and control technologies, and provides public access to

information on their use, effectiveness, and cost (www.epa.gov/ttn/catc/).

» The RACT/BACT/LAER Clearinghouse (www.epa.gov/ttn/catc/).

» Improving Air Quality with Economic Incentive Programs, EPA-452/R-01-001,

January 2001, available at www.epa.gov/ttn/oarpg/t1main.html and through EPA’s

Air and Radiation Docket and Information Center (Docket Number A-97-27) by

calling (202) 260-7548.

7. RACT is defined as the “devices, systems, process modifications, or other apparatus or

techniques that are reasonably available taking into account: (1) The necessity of

imposing such controls in order to attain and maintain a national ambient air quality

standard; (2) The social, environmental, and economic impact of such controls; and (3)

Alternative means of providing for attainment and maintenance of such standard.” 

RACT connotes a device or technological method such as a scrubber or baghouse or

reformulation of coatings to reduce VOC content whereas RACM connotes a pollution

prevention or other practice or measure —although the difference is not absolute. In

general, the existing sources in nonattainment areas must meet emissions limits

achievable by RACT. For more information, see the RACT/BACT/LAER Clearinghouse

(www.epa.gov/ttn/catc/), and Procedures for Identifying Reasonably Available Control

Technology for Stationary Sources of PM10 (EPA 452/R-93-001), September 1992,

available through the Clear Air Technology Center products page

(www.epa.gov/ttn/catc/). 

8. BACT refers to the “best available control technology,” an emission limitation based on

the maximum degree of emission reduction (considering energy, environmental, and

economic impacts) achievable through application of production processes and available

methods, systems, and techniques. Use of the BACT concept is allowable on a case by

case basis for major new or modified emission sources in attainment areas (used under

the Prevention of Significant Deterioration program) and applies to each pollutant
 Chapter 4 Page 83

regulated by PSD. LAER refers to the “lowest achievable emission rate,” which is the

rate of emissions that reflects (a) the most stringent emission limitation in the

implementation plan of any state for such source unless the owner or operator

demonstrates such limitations are not achievable; or (b) the most stringent emissions

limitation achieved in practice, whichever is more stringent. LAER is usually required in

the New Source Review program.

9. Regulations for economic incentive programs are in 40 CFR 51.490 through 51.494. 

Guidance on developing an economic incentive program can be found in Improving Air

Quality with Economic Incentive Programs, EPA-452/R-01-001, January 2001, available

at www.epa.gov/ttn/oarpg/t1main.html and through EPA’s Air and Radiation Docket and

Information Center (Docket Number A-97-27) by calling (202) 260-7548.

10. The requirement for contingency measures is established in the CAA section 172(c)(9)

and codified in 40 CFR 51.152.

11. For more information on NSR, see www.epa.gov/ttn/nsr/.

12. 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 definition of major source is given in 40 CFR 51.165(a)(1)(iv). For serious PM

nonattainment areas, the definition of a major source is in the CAA section 188. For

moderate, serious, severe, and extreme ozone nonattainment areas, the definition of major

source is in the CAA section 182(b), (c), (d), and (e), respectively. Definitions for major

modifications in the NSR and PSD programs can be found in 40 CFR 51.165(a)(1)(v)

and 51.166(b)(2)(i). The term “significant” is defined for these programs in 

40 CFR 51.165(a)(1)(x) and 51.166(b)(23).

13. New major sources of hazardous air pollutants (HAPs, defined in the section 112 of the

CAA) are not subject to the nonattainment or attainment major New Source Review

programs discussed here. 

14. A source’s “potential to emit” is its emission estimate based on the maximum capacity of

that source, taking into consideration enforceable permit conditions, such as the type of

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

15. “Offsets” are emissions reductions obtained from existing source(s) by a prospective

major new stationary source, or a source planning major modifications, in order to offset

the increase in pollutant emissions caused by the new or modified source (thereby

creating no net increase in emissions). Offsets must always be greater than the amount of

the new emissions, depending on the area’s air quality designation. Offsets are generally

secured from other sources in the vicinity of the new source or modification. However, in

the case of modifications, offsets can also be obtained, with limitations, from within the

source itself.
 Chapter 4 Page 84

16. PSD increments for NO2, PM, and SO2 Class I, II, and III areas are specified in the CAA

section 163 and in 40 CFR 51.166(c). Currently there are no increments for CO, O3, or

Pb.

17. For more information on area redesignation under the PSD program, see the CAA

section 164 and Appendix H, Procedures for Area Redesignation to Class I.

18. If your tribe adopts federal PSD regulations by reference in an approved TIP, when

reading 40 CFR 52.21, substitute the appropriate tribal authority for references to the

EPA “Administrator.”

19. Information on air quality models is available at EPA’s Support Center for Regulatory

Air Models (www.epa.gov/ttn/scram/).

20. Biogenic sources are non-manmade or natural emitters of air pollutants. For example,

conifer trees emit terpenes which are volatile organic compounds, a precursor to ozone.

21. See the Visibility Program website of the Office of Air and Radiation for more

information on regional haze (www.epa.gov/oar/vis/index.html).

22. For more information on petitioning EPA for a finding that upwind sources are

contributing significantly to NAAQS violations on your reservation, see the CAA section

126 and www.epa.gov/ttn/rto/126/.