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Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

No comments objecting to the proposal

were received. Class E airspace areas

extending from 700 feet or more above

the surface of the earth are published in

paragraphs 6005 of FAA Order 7400.96,

signed August 14, 2007, and effective

September 15, 2007, which is

incorporated by reference in 14 CFR

71.1. The class airspace designation

listed in this document will be

published subsequently in the Order.

The Rule

The FAA is amending Title 14, Code

of Federal Regulations (14 CFR) part 71

to modify Class E airspace at

Waynesburg, PA, by providing

additional controlled airspace for

aircraft executing the RNAV (GPS)

Runway 09/27 to the Green County

Airport. This action also corrects the

geographic position coordinates of the

airport.

The FAA has determined that this

regulation only involves an established

body, of technical regulations for which

frequent and routine amendments are

necessary to keep them operationally

current. It, therefore, (1) is not a "significant regulatory action" under

Executive Order 12866; (2) is not a "significant rule" under DOT

Regulatory.Policies and Procedures (44

FR 11034; February 26, 1979); and (3)

does not warrant preparation of a

Regulatory Evaluation as the anticipated

impact is so minimal. Since this is a

routine matter that will only affect air

traffic procedures and air navigation, it

is certified that this rule, when

promulgated, will not have a significant

economic impact on a substantial

number of small entities under the

criteria of the Regulatory Flexibility Act.

The FAA's authority to issue rules

regarding aviation safety is found in the

Title 49 of the United States Code.

Subtitle I, Section 106 describes the

authority of the FAA administrator.

Subtitle VII, Aviation Programs,

describes in more detail the scope. of the

agehcy's authority.

This rulemaking is promulgated

under the authority described in

Subtitle VII, Part A, Subpart 1, Section

40103. Under that section, the FAA is

charged with prescribing regulations to

assign the use of airspace necessary to

ensure the safety of aircraft and the

efficient use of airspace. This regulation

is within the scope of that authority as

it modifies Class E Airspace at

Waynesburg, PA.

List of Subjects in 14 CFR Part 71

Airspace, Incorporation by reference,

Navigation (air).

Adoption of the Amendment

m In consideration of the foregoing, the

Federal Aviation Administration

amends 14-CFR part 71 as follows:

PART 71-DESIGNATION OF CLASS A,

-CLASS B, CLASS C, CLASS D, AND

CLASS E AIRSPACE AREAS;

AIRWAYS; ROUTES; AND REPORTING

POINTS

m 1. The authority citation for part 71

continues to read as follows:

Authority: 49 U.S.C. 106(g); 40103, 40113,

40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-

1963 Comp., p. 389.

§71.1 [Amended]

a 2. The incorporation by reference-in

14 CFR 71.1 of Federal Aviation

Administration Order 7400.9R, Airspace

Designations and Reporting Points,

signed August 15, 2007, and effective

September 15, 2007, is amended as

follows:

Paragraph 6005 Class E Airspace Areas

Extending Upward from 700 feet or More

Above the Surface of the Earth.

AEA PA E5 Waynesburg, PA [Revised]

Green County Airport, PA

(Lat. 39°54'04" N., long. 80°07'51" W.)

That airspace extending upward from 700

feet above the surface of the Earth within an 8.3-mile radius of Green County Airport.

Issued in College Park, Georgia, on April

21, 2008.

Lynda G. Otting,

Acting Manager, System Support Group,

Eastern Service Center, Air Traffic

Organization.

[FR Doc. E8-10425 Filed 5-15-08; 8:45 am]

BILLING CODE 4910-13-M

DEPARTMENT OF HOMELAND

SECURITY

Coast Guard

33 CFR Part 165

[Docket No. USCG-2008-0366]

Security Zone; Portland Rose Festival

on Willamette River - •

AGENCY: Coast Guard, DHS.

ACTION: Notice .of enforcement of

regulation.

SUMMARY: The Coast Guard will enforce

the Portland Rose Festival Security

Zone on the Willamette River from 1

a.m. on June 4, 2008 until 10 a.m. June

10, 2008. This action is necessary for the

security of public vessels on a portion

of the Willamette River during the fleet

week of the Rose Festival. This security

zone provides for the regulation of

vessel traffic in the vicinity of the

moored public vessels. During the

enforcement period, entry into this zone

is prohibited unless authorized by the

Captain of the Port or his designee.

DATES: The .regulations in 33 C FR

165.1312 will be enforced'commencing

from 1 a.m. on June 4, 2008 until 10

a.m. June 10, 2008.

FOR FURTHER INFORMATION CONTACT:

MST1 Lucia Mack, Coast Guard Sector

Portland, 6767 N. Basin Ave, Portland,

OR 97217, telephone 503-240-9311.

SUPPLEMENTARY INFORMATION: The Coast

Guard will enforce the Rose Festival

Security Zone established by 33 CFR

165.1312 from 1 a.m. on June 4, 2008

until 10 a.m. June 10, 2008.

Under the provisions of 33 CFR

165.33 a vessel may not enter the

regulated area, unless it receives

permission from the Captain of the Port

or his designee. The Coast Guard may be

assisted by other Federal, State, or local

law enforcement agencies in enforcing

this regulation.

This notice is issued under authority

of 33 CFR 165.1312 and 5 U.S.C. 552(a).

In addition to this notice in the Federal

Register, the Coast-Guard will provide

the maritime community with extensive

advance notification of this enforcement

period via the Local Notice to Mariners

and marine information broadcasts.

Dated: May 6, 2008.

F.G. Myer,

Captain, U.S. Coast Guard, Captain of the

Port, Portland. .

[FR Doc. E8-10921 Filed 5-15-08; 8:45 am]

BILLING CODE 4910-15-P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Parts 51 and 52

[EPA-HQ-OAR-2003-0062; FRL-8566-1]

RIN 2060-AN86

Implementation of the New Source

Review (NSR) Program for Particulate

Matter Less Than 2.5 Micrometers

(PM 2.5)

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: The EPA is finalizing

regulations to implement the New

Source Review (NSR) program for fine

particulate matter (that is, particles with

an aerodynamic diameter less than or

equal to a'nominal 2.5 micrometers,

28321
28322 Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

generally referred to as "PM 2.5"). The

NSR program was created by the Clean

Air Act (Act or CAA) to ensure that

stationary sources of air pollution are

constructed or modified in a manner

that is consistent with air quality goals

in the area.

The Clean Air Fine Particle

Implementation Rule, which was

proposed in the Federal Register on

November 1, 2005, included

requirementS'and guidance for State and

local air pollution agencies to follow in

developing State implementation plans

(SIPs) and also the NSR provisions. The

final implementation rule that was

promulgated on April 25, 2007,

included all the SIPs related provisions.

In this rulemaking, EPA is finalizing the

NSR provisions of the November 1, 2005

proposed rule including the major

source threshold, significant emissions

rate, and offset ratios for PM 2.

5,

interpollutant trading for offsets and

applicability of NSR to PM 2.

5 precursors.

DATES: This final rule is effective on July

15, 2008.

ADDRESSES: The EPA has established a

docket for this action under Docket ID

No. EPA-HQ-OAR-2003-0062. All

documents in the docket are listed on

the www.regulations.gov Web site.

Although listed in the index, some

information may not be publicly

available, e.g., CBI or other information

whose disclosure is restricted by statute.

Certain other material, such as

copyrighted material, is not placed on

the Internet and will be publicly

available only in hard copy form.

Publicly available docket materials are

available either electronically through

www.regulations.gov or in hard copy at

the Air Docket, EPA/DC, EPA West,

Room 3334, 1301 Constitution Avenue,

Northwest, Washington, DC. The Public

Reading Room is open from 8:30 a.m. to

4:30 p.m., Monday through Friday,

excluding Jegal holidays. The telephone

number for the Public Reading Room is

(202) 566-1744, and the telephone

number for the Air Docket is (202) 566-

1742.

FOR FURTHER INFORMATION CONTACT: Mr.

Raghavendra (Raj) Rao, Air Quality

Policy Division, Office of Air Quality

Planning and Standards (C504-03), U.S.

Environmental Protection Agency,

Research Triangle Park, North Carolind

27711, telephone -umber: (919) 541-

5344, facsimile number: (919) 541-5509,

e-mail address: rao.raj@epd.gov; or Mr.

Dan deRoeck, at the same address,

telephone 919-541-5593, or e-mail at

deroeck.dan@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

Entities affected by this rule include

sources in all industry groups. The

majority of sources potentially affected

are expected to be in the following

groups:,

Industry group .NAICSa

Electric services ........................................................................................ 221111, 221112, 221113, 221119, 221121, 221122

Petroleum refining ................................................................................... 32411

Industrial inorganic chemicals ....................................................... I ......... 325181, 32512, 325131, 325182, 211112, 325998, 331311, 325188

Industrial organic chemicals .................................................................... 32511, 325132, 325192, 325188, 325193, 32512, 325199

Miscellaneous chemical products ............................................................ 32552, 32592, 32591, 325182, 32551

Natural gas liquids ................................................................................... 211112

Natural gas transport ................................................................................ 48621, 22121

Pulp and paper mills ................................................................................. 32211, 322121,322122, 32213

Paper m ills ................................................................................................ 322121, 322122

Automobile manufacturing ........................................................................ 336111, 336112, 336712, 336211, 336992, 336322, 336312, 33633,

33634, 33635, 336399, 336212, 336213

Pharmaceuticals ....................................................................................... 325411, 325412, 325413, 325414

a North American Industry Classification System.

Entities affected by this rule also

include States, local reviewing

authorities, and Indian country with

new and modified major stationary

sources.

B. Where can I get a copy of this

document and other related

information?

In addition to being available in the

docket, an electronic copy of this final

rule will also be available on the World

Wide Web. Following signature by thb

EPA Administrator, a copy of this final

rule will be posted in the regulations

and standards section of our NSR home

page located at http://www.epa.gov/nsr.

C. How is this preamble organized?

The information presented, in this

preamble is organized as follows:

I. General Information

A. Does this action apply to me?

B. Where can I get a copy of this document

and other related information?

C. How is this preamble organized?

II. Purpose

III. Background

A. New Source Review (NSR) Program

B. Fine Particulate Matter and the NAAQS

for PM 2.

5

C. Implementation of NSR for PM2 .5

IV. Overview of This Final Action

V. Rationale for Final Actions

A. Applicability of NSR to Precursors uf

PM 2.5 in the Ambient Air

1. What is EPA's legal authority to regulate

precursors?

2. What is EPA's approach for addressing

precursors?

3. Final Action on SO2

4. Final Action on NOx

5. Final Action on VOC

6. Final Action on Ammonia

B. Major Stationary Source Threshold for

PM 2.

5

C. Significant Emissions Rate for Direct

Emissions of PM 2.

5

D. Significant Emissions Rates for PM 2.5

Precursors

E. Condensable PM Emissions

F. Prevention of Significant Deterioration

(PSD) Program Requirements

1. How must BACT be implemented for

PM 2.s?

2. How does EPA plan to address PM 2.5

Increments, Significant Impact Levels

(SILs), and Significant Monitoring

Concentiations (SMCs)?

3. What is the ambient air quality analysis

requirement for PM 2.

5?

4. How must the PSD preconstruction

monitoring requirement be implemented

for PM 2.

5 ?

G. Nonattainment New Source Review (NA

NSR) Requirements

1. What is the required offset ratio for

direct PM 2.

5 emissions?

2. Which precursors are subject to the

offset requirement?

3. What is the required offset ratio for PM 2_5

precursors?

4. Is interpollutant trading allowable to

comply with offset requirements?

H. How will the transition to the PM 2.

5 PSD

requirements occur?

1. Background

2. Transition for "Delegated States"

3. Transition for "SIP-Approved States"

I. How will the transition to thdPM2.

5 NA

NSR requirements occur?

1. Background

2. Transition
Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

3. Implementation of NSR Under the

"Emissions Offset Interpretative Ruling"

(40 CFR -part 51, appendix S) with

Revisions

J. Does major NSR apply to PM 2.5

precursors during the SIP development

period?

K. Are there any Tribal concerns?

L. What are the requirements for minor

NSR for PM 2.

5?

M. Rural Transport Areas

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory

Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

E. Executive Order 13132-Federalism

F. Executive Order 13175--Consultation

and Coordination with Indian Tribal

Governments

G. Executive Order 13045-Protection of

Children from Environmental Health and

Safety Risks

H. Executive Order 13211-Actions That

Significantly Affect Energy Supply,

Distribution, or Use

I. National Technology Transfer and

Advancement Act

J. Executive Order 12898-Federal Actions

to Address Environmental Justice in

Minority Populations and Low-Income

Populations

K. Congressional Review Act

L. Petitions for Judicial Review

M. Determination Under Section 307(d)

VII. Statutory Authority

II. Purpose

The purpose -of this rulemaking is to

finalize the major NSR program

provisions for PM2.5. This final rule

supplements the final implementation

rule for PM2.5 (excluding the NSR

provisions) that we 1 promulgated on

April 25, 2007 at 72 FR 20586. This

final action on the bulk of the major

NSR program for PM2.5 along with our

proposed rule on increments, SILs, and

SMC, when final, will represent the

final elements necessary to implement a

PM2.5 PSD program. When both rules are

promulgated and in effect, the PM2.5

PSD program will no longer use a PM1o

program as a surrogate, as has been the

practice under our existing guidance.

1II. Background

A. New Source Review (NSR) Program

The existing regulations require both

major and minor NSR programs to

address any pollutant for which there is

a National Ambient Air Quality

Standard (NAAQS) and precursors to

the formation of such pollutant when

identified for regulation by the

Administrator. This final rule amends

the NSR regulations to establish the

minimum elements for State, local, and

Tribal agency programs implementing

NSR for the PM2.5 NAAQS. This

preamble also explains what interim

provisions would apply with respect to

PM2.5 during the State Implementation

Plan (SIP) development period.

The NSR program is a preconstruction

permitting program that applies when a

source is constructed or modified. The

NSR program is composed of three

different programs:

e Prevention of Significant

Deterioration (PSD);

" Nonattainment NSR (NA NSR); and

" Minor NSR.

We often refer to the PSD and NA NSR

programs together as the major NSR

program because these programs

regulate only major sources. 2

The PSD program applies when a

major source that is located in an area

that is designated as attainment or

unclassifiable for any criteria pollutant

is constructed or undergoes a major

modification. 4 The NA NSR program

applies when a major source that is

located in an area that is designated as

nonattainment for any criteria pollutant

is constructed or undergoes a major

modification. The minor NSR program

addresses both major and minor sources

that undertake construction or

modification activities that do not

qualify as major, and it applies

regardless of the designation of the area

in which a source is located.

The national regulations that apply to

each of these programs are located in

the Code of Federal Regulations (CFR)

as shown in the following table:

Program Applicable regulations

PSD .......................................................................................................... 40 CFR 52.21, 40 CFR 51.166, 40 CFR 51.165(b).

NA NSR .................................................................................................... 40 CFR 52.24, 40 CFR 51"165, 40 CFR part 51, appendix S.

Minor NSR ................................................................................................ 40 CFR 51.160-164.

The PSD requirements include but are

not limited to:

* Installation of Best Available

Control Technology (BACT);

# * Air quality monitoring and

modeling analyses to ensurethat a

project's emissions will not cause or

contribute to a violation of any NAAQS

or maximum allowable pollutant

increase (PSD increment);

• Notification of Federal Land

Manager of nearby Class I areas; and

• Public comment on the permit.

Nonattainment NSR requirements

include but are not limited to:.

e Installation of Lowest Achievable

Emission Rate (LAER) control

technology;

'In this proposal, the terms "we," "us," and

"our," refer to the EPA and the terms "you," and

"your," refer to the owners or operators of

stationary sources of air pollution.

o Offsetting new emissions with

creditable emissions reductions; o Certification that all major sources

owned and operated in the State by the

same owner are in compliance with all

applicable requirements under the Act;

* An alternative siting analysis

demonstrating that the benefits of the

proposed source significantly outweigh

the environmental and social costs

imposed as a result of its location,

construction, or modification; and e Public comment on the permit.

Minor NSR programs must meet the

statutory requirements in section

110(a)(2)(C) of the Act, which requires ..* * regulation of the modification

and construction of any stationary

source * * * as necessary to assure that

ZThe Act uses the terms "major emitting facility"

to refer to sources subject to the PSD program, and "major stationary source" to refer to sources subject to NA NSR. SeeCAA sections 165,169,172(c)(5),

and 302(j). For ease of reference, we use the term

"major source" to refer to both terms.

national ambient air quality standards

are achieved."

B. Fine Particulate Matter and the

NAAQS for PM2.5

Fine particles in the atmosphere are

made up of a complex mixtur6 of

components. Common constituents

include sulfate (SO4 ); nitrate (NO,);

ammonium; elemental carbon; a great

variety of organic compounds; and

inorganic material (including metals,

dust, sea salt, and other trace elements)

generally referred to as "crustal"

material, although it may contain.

material from other sources. Airborne

particulate matter (PM) with a nominal

aerodynamic diameter of 2.5.

miciometers or less (a micrometer is

3 The term "criteria pollutant" means a pollutant

for which we have set a NAAQS.

4 In addition, the PSD program applies to most

noncriteria regulated pollutants.

I 28323
Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

one-millionth of a meter, and 2.5

micrometers is less than one-seventh the

average width of a human hair) are

considered to be "fine particles," and

are also known as PM2.5. "Primary"

particles are emitted directly into the air

as a solid or liquid particle (e.g.,

elemental carbon from diesel engines or

fire activities, or condensable organic

particles from gasoline engines).

"Secondary". particles (e~g., sulfate and

nitrate) form ip the atmosphere as a

result of various chemical reactions.

The health effects associated with

exposure to PM 2.

5 are significant.

Epidemiological studies have shown a

significant correlation between elevated

PM2.5 levels and premature mortality.

Other important effects associated With

PM2.

5 exposure include aggravation of

respiratory and cardiovascular disease

(as indicated by increased hospital

admissions, emergency room visits,

absences from school or work, and

restricted activity days), lung disease,

decreased lung function, asthma attacks,

and certain cardiovascular problems.

Individuals particularly sensitive to

PM2.

5 exposure include older adults,

people-with heart and lung disease, and

children.

On July 18, 1997, we revised the

NAAQS for PM to add new standards

for fine particles, using PM2.5 as the

indicator. We established health-based

(primary) annual and 24-hour standards

for PM2.5 (62 FR 38652). We set an annual standard at a level of 15

micrograms per cubic meter (gg/m 3

) and

a 24-hour standard at a level of 65 gg/

M 3

. At the time we established the

primary standards in 1997, we also

established welfare-based (secondary)

standards identical t o the primary

standards. The secondary standards are

designed to protect against major

environmental effects of PM2.

5 such as

visibility impairment, soiling, and

materials damage.

On October 17, 2006, we revised the

primary and secondary NAAQS for

PM2:5 and PM1o. In that rulemaking, we

reduced the 24-hour NAAQS for PM2.5

to 35 gg/m 3 and retained the existing

annual PM2.5 NAAQS of 15 gg/m3. In

addition, we retained PMo as the

indicator for coarse PM, retained the

existing PM1o 24-hour NAAQS of 150

jg/m3

, and revoked the annual PM10

NAAQS (which had previously been set

at 50 gg/m3). See 71 FR 61236.

5

Available in the docket for this rulemaking, ID

No. EPA-HQ-OAR-2003-0062, and at http://

www.epa.gov/regiono7/progroms/artdlair/nsr/

nsrmemos/pm25.pdf.

C. Implementation of NSR for PM2.5

After we promulgated the NAAQS for

PM2.

5 in 1997, we issued a guidance

document entitled "Interim

Implementation for the New Source

Review Requirements for PM 2.

5" (John

S. Seitz, EPA, October 23, 1997). 5 As

noted in that guidance, section 165 of

the Act suggests that PSD requirements

become effective for a new NAAQS

upon the effective date of the NAAQS.

Section 165(a)(1) of the Act provides

that no new or modified major source

may be constructed without a PSD

permit that meets all of the section

165(a) requirements with respect to the

regulated pollutant. Moreover, section

165(a)(3) provides that the emissions

from any such source may not cause or

contribute to a violation of any NAAQS.

Also, section 165(a)(4) requires BACT

for each pollutant'subject to PSD

regulation. The 1997 guidance stated

that sources would be allowed to use

implementation of a PM1o program as a surrogate for meeting PM2.

5 NSR

requirements until certain difficulties

were resolved, primarily the lack of

necessary tools to calculate the

emissions of PM2 .5 and related

precursors, the lack of adequate

modeling techniques to project ambient

impacts, and the lack of PM2.5

monitoring sites.

On April 5, 2005, we issued a

guidance document entitled

"Implementation of New Source Review

Requirements in PM-2.5 Nonattainment

Areas" (Stephen D. Page, EPA). 6 This

memorandum provides guidance on the

implementation of the nonattainment

major NSR provisions in PM2.5

nonattainment areas in the interim

period between the effective date of the

PM2.

5 NAAQS designations (April 5,

2005) and the promulgation date of the

final NSR regulations reflected in this

action. Besides affirming the

continuation of the Seitz guidance

memo in PM2 .

5 attainment areas, the

April 5, 2005 memo recommends that

until we promulgate the PM2.5 major

NSR regulations, States should use a PM10 nonattainment major NSR program

as a surrogate to address the

requirements of nonattainment major

NSR for PM2.

5. On November 1, 2005, we proposed a

rule to implement the 1997 PM2.

5

NAAQS, including proposed revisions

to the NSR program (70 FR 65984). As

discussed above, this action finalizes

the portion of that proposal related to

6 Available in the docket for this rulemaking, ID.

No. EPA-HQ-OAR-2003-0062, and at http://

www.epa.gov/nsr/documents/nsrnemo.pdf.

NSR. The other portions of that

proposal, concerning attainment dates,

SIP submittals, reasonable further

progress (RFP) requirements, etc., were

finalized on April 25, 2007 (72 FR

20586).

On September 21, 2007, we proposed

additional elements for th% PSD

program for PM2.

5 including PM 2.

5

"increments," significant impact levels

(SILs), and significant monitoring

concentrations (SMCs) (72 FR 54112).

Increments are the maximum allowable

increases over baseline concentrations

that can be permitted to occur when a

major source is constructed or modified.

This is one mechanism by which the

PSD program prevents significant

deterioration in air quality. A SIL

defines the level of ambient air impact

that is considered a "significant

contribution" to air quality. If the

modeled maximum ambient impacts of

a new source or modification are below

the SILs, the source: (1) Is presumed not

to cause or contribute significantly to a

PSD increment or NAAQS violation,

and (2) is not required to perform the

multiple-source, cumulative impacts

assessments that are otherwise required

under PSD. An SMC defines the level of

modeled ambient air impact below

which the reviewing authority may

.exempt a new or modified source from

conducting the preconstruction

monitoring that may otherwise be

required under PSD. The reviewing

authority may also exempt the source

from preconstruction monitoring if the

existing monitored ambient

concentration is less than the SMC. This

final action on the bulk of the major

NSR program for PM2.5 along with our

proposed rule on increments, SILs, and

SMC, when final, will represent the

final elements necessary to implement a

PM 2.5 PSD program. When both rules are

promulgated and in effect, the PM2.

5

PSD program will no longer use a PM10

program as a surrogate, as has been the

practice under our existing guidance.

IV. Overview of This Final Action

The table below summarizes the main

elements of the existing NSR program

that this action addresses for PM2.5 as a

regulated NSR pollutant. The table

indicates our final position on an issue

and whether our position has changed

based on comments received. Our final

action for each element, or where

appropriate, explanation of

implementation under existing

28324
Federal Register/Vol. 73, No..96/Friday, May 16, 2008/Rules and Regulations

regulations, is addressed in detail in the

referenced sections of this preamble.

NSR program element Final action Section

Applicability to PM2.5 precursors ............. SO-Must be regulated as precursor, NOx-Presumed rejulated, VOC-Pre- V.A

sumed not regulated, Ammonia-Presumed not regulated. PSD major source threshold ................... 100/250 tons per year (tpy) ..........................................................

V.B

NA N SR m ajor source threshold ............ 100 tpy .......................................................................

V .B

Significant emissions rate ....................... Direct PM2.

5 emissions-10 tpy, SO2 precursor--40 tpy, NOx precursor-40 tpy, V.C & V.D

if regulated. Condensable PM2.5 emissions ................ Included in direct PM2.

5 emissions for major NSR applicability determinations V.E

after the end of the transition period (changed based on comments received). Control technology: BACT and LAER ..... Applies for direct PM2., emissions, SO2, and other precursors if regulated. V.F.1 & V.G

Prevention of significant deterioration ..... Increments, SILs and SMCs covered in a separate rulemaking ........................... V.F.2

Air quality im pact analysis ...................... Applies for PM 2.. .................................................................

V.F.3

Preconstruction monitoring ..................... Applies for PM2.5 (finalizing options 1 & 3) ................................................

V.F.4

NA NSR Statewide compliance and al- Applies for direct PM2.5 emissions and precursors, if regulated ............................ V.G

temative siting analyses. NA NSR offsets ....................................... Applies for direct PM2.

5 emissions and precursors, if regulated ............................ V.G.1-3

Interpollutant offsetting ............................ Allowed on a regional or statewide basis; EPA is issuing guidance with rec- V.G.4

ommended regional hierarchies and trading ratios (changed based on comments received). Transition for PSD ................................... Continues to use PM1o as a surrogate ...................................................

V.H

Transition for NA NSR ............................ Applies through an approved SIP or through 40 CFR part 51, appendix S .......... V.1

SIP development period .......................... Clarifies that major NSR does not apply to precursors during the SIP develop- V.J

ment period in attainment areas (changed based on comments received). Tribal concerns ........................................ Cross references to proposed NSR rules for Indian country .............................. V.K

Minor NSR ............................................... Clarifies that State and local regulatory programs must include PM2., require- V.L

ments for minor sources.

NSR transport option .............................. Transport classification not available ....................................................

V.M

The provisions of the PM2.5 major

NSR program finalized in this action are

codified as. revisions in the previously

existing regulatory text. The revisions to

NA NSR are codified in 40 CFR 51.165

and appendix.S to 40 CFR part 51. The

PSD revisions are codified in 40 CFR

51.166 and 52.21.

V. Rationale for Final Actions

In this section we discuss each

element of our proposal'for this

rulemaking, explain our final action,

discuss the rationale for our final action,

and summarize the major public

comments we received. The full

summary of public comments on the

proposal, along with our responses, can

be founcrinthe docket for this

rulemaking.7

A. Applicability of NSR to Precursors of

PM 2 .5 in the Ambient Air

Scientific research has shown that

various pollutants can contribute to

'ambient PM 2., concentrations. In

additibn to direct PM2 .5 emissions, these

include the following precursors:

" Sulfur dioxide (SO 2);

" Oxides of nitrogen (NOx);

" Volatile organic compounds (VOC);

and

7 See "Implementation of the New Source Review

(NSR) Program for Particulate Matter Less Than 2.5

Micrometers in Diameter (PM2 .5); Response to

Comments," U.S. Environmental Protection

Agency. It can be viewed or downloaded at www.regulations.gov, Docket ID No. EPA-HQOAR-2003-0062.

* Ammonia.

.These gas-phase precursors undergo

chemical reactions in the atmosphere to

form secondary PM. Formation of

secondary PM depends on numerous

factors including the concentrations of

precursors; the concentrations of other

gaseous reactive species; atmospheric

conditions including solar radiation,

temperature, and relative humidity; and

the interactions of precursors with

preexisting particles and with cloud or

fog droplets. Several atmospheric

aerosol species, such as ammonium

nitrate and certain organic compounds,

are semi-volatile and are found in both

gas and particle phases. Given the

complexity of PM formation processes,

new information from the scientific

community continues to emerge to

improve our understanding of the

relationship between sources of PM

precursors and secondary particle

formation.

Precursors contribute significantly to

ambient PM2.5 concentrations,

producing approximately half of the

concentration nationally. In most areas

of the country, PM2.5 precursor

emissions are major contributors to

ambient PM2.5 concentrations. The

relative contribution to ambient PM2.

5

concentrations from each of these

pollutants varies by area. The relative

effect of reducing emissions of these

pollutants is also highly variable.

Some PM2.5 precursors are already

subject to major NSR under other

NAAQS, as shown in the following

table:

PM 25 Existing program coverage

precursor for major NSR applicability

NOx ................ NA NSR and PSD for NO2 and Ozone.

SO2 ...... . ..... ... NA NSR and PSD for SO2.

VOC ............... NA NSR and PSD for

Ozone.

Ammonia ....... No coverage for NSR. -

In the subsections that follow, we first

discuss our legal authority under the

Act for regulating precursors to the

formation of criteria pollutants, and

then discuss our final action for each of

the PM2.5 precursors. •

1. What is EPA's legal authority to

regulate precursors?

As we discussed in the November 1,

2005 proposal, we interpret the Act to

not only provide explicit authority for

EPA to regulate precursors, but also to

grant us discretion to determine how to

address precursors for particular

regulatory purposes. This reading is

based on section 302(g) of the Act,

which defines the term "air pollutant"

to include "any precursors to the

formation of any air pollutant, to the

extent the Administrator has identified

such precursor or precursors for the

particular purpose for which the term

'air pollutant' is used." The first clause

of this second sentence in section 302(g)

explicitly authorizes the Administrator

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to identify and regulate precursors as air

pollutants under other parts of the Act.

In addition, the second clause of the

sentence indicates that the

Administrator has discretion to identify

which pollutants should be classified as

precursors for particular regulatory

purposes. Thus, we do not necessarily

construe the Act to require that EPA

identify a particular precursor as an air

pollutant for all regulatory purposes

where it can be demonstrated that

various programs under the Act address

different aspects of the air pollutant

problem. Likewise, we do not interpret

the Act to require that EPA treat all

precursors of a particular pollutant the

same under any one program when

there is a basis to distinguish between

such precursors within that program.

For example, in a recent rule addressing

PM2.5 precursors for purposes of the

transportation conformity program, we

chose to adopt a different approach for

one precursor based on the limited

emissions of that precursor from onroad

mobile sources and the degree to which

it contributes to PM2.

5 concentrations

(70 FR 24280, May 6, 2005).

Other provisions of the Act reinforce

our reading of section 302(g) to mean

that Congress intended precursors to

NAAQS pollutants to be subject to the

air quality planning and control

requirements of'the Act, but also

recognized that there may be

circumstances where it is not

appropriate to subject precursors to

certain requirements of the Act. Section

182 of the Act provides for the

regulation of NOx and VOC as

precursors to ozone in ozone

nonattainment areas, but also provides

in section 182(f) that major stationary

sources of NOx (an ozone precursor) are

not subject to emission reduction

requirements for ozone where the State

shows through modeling that NOx

reductions do not decrease ozone.

Section 189(e) provides for the

regulation of PM10 precursors in PM10

nonattainment areas, but also recognizes

that there may be certain circumstances

(e.g., if precursor emission sources do

not significantly contribute to PM1o

levels) where it is not appropriate to

apply control requirements to PM10

precursors. The legislative history of

section 189(e) recognized the

complexity behind the science of

precursor transformation into PM10

ambient concentrations and the need to

harmonize the regulation of PM1o

precursors with other provisions of the -

Act:

The Committee notes that some of these

precursors may well be controlled under

other provisions of the CAA. The Committee

intends that * * * the Administrator will

develop models, mechanisms, and other

methodology to assess the significance of the

PM1Q precursors in improving air quality and

reducing PM 0 . Additionally, the

Administrator should consider the impact on ozone levels of PM10 precursor controls. The

Committee expects the Administrator to

harmonize the PM10 reduction objective of

this section with other applicable regulations

of this CAA regarding PM 0 precursors, such as NOx.

See H. Rpt. 101-490, Pt. 1, at 268 (May

17, 1990), reprinted in S. Prt. 103-38,

Vol. II, at 3292.

In summary, section 302(g) of the Act

clearly calls for the regulation of

precursor pollutants, but the Act also

identifies circumstances when it may

not be appropriate to regulate precursors

and gives the Administrator discretion

to determine how to address particular

precursors under various programs

required by the Act. Due to the

complexities associated with precursor

emissions and their variability from

location to location, we believe that in

certain situations it may not be effective

or appropriate to control a certain

precursor under a particular regulatory

program or for EPA to require similar

control of i particular precursor in all

,;.reas of the country.

The term "air pollutant," as defined

in section 302(g), is incorporated into

the NSR provisions for various

purposes. Thus, we interpret section

302(g) of the Act to require us to

consider how to address precursors

under the NSR program.

With regard to PSD, section 165(a)(3)

of the Act states that new or modified

major sources must demonstrate that

emissions "will not cause, or contribute

to, air pollution in excess of any * * *

NAAQS in any air quality control region

* * t." A source could not reasonably

make this demonstration without

considering precursors that EPA has

identified for this purpose. Section

165(a)(4) of the Act states that a new or

modified source must apply BACT "for

each pollutant subject to regulation

under this Act emitted from, or which

results from, such facility." The phrase "emitted from, or which results from"

indicates that the statute is not limited

to direct emissions, but rather extends

to precursors as well.

With regard to NA NSR, sections

172(c)(4) and 173 require States to

demonstrate, among other things, that

emissions from new or modified major

sources are consistent with the

achievement of "reasonable further

progress." Reasonable further progress

is further defined as reductions of the

relevant air pollutant, which is defined

in section 302(g) to include precursors

identified by EPA as subject to

regulation for that purpose.

2. What is EPA's approach for

addressing precursors?

As proposed, we are finalizing

different approaches for addressing the

individual precursors to PM2.5 under the

Act's NSR provisions. Generally, where

the scientific data and modeling

analyses provide reasonable certainty

that the pollutant's emissions are a

significant contributor to ambient PM2.

5

concentrations, we believe that

pollutant should be identified as a "regulated NSR pollutant" and subject

to the PM2.

5 NSR provisions.

C6nversely, where the effect of a

pollutant'g emissions on ambient PM2.

5

concentrations is subject to substantial

uncertainty, such that in some

circumstances the pollutant may not

result in formation of PM2.

5, or control

of the pollutant may have no effect or

may even aggravate air quality,.we

generally believe it is unreasonable to

establish a nationally-applicable

presumption that the pollutant is a

regulated NSR pollutant subject to the

requirements of NSR for PM 2.5. We

discuss our final action with respect to

,each of the PM2.5 precursors and the

basis for that action in sections V.A.2

through 5.

For those precursors that are either

presumed to be regulated or not

regulated (NOx, VOC, and ammonia), a

State program need not follow the

presumed approach if it can be

demonstrated that the precursor in

question is not, or is, a "significant

contributor" to PM2.

5 concentrations

within the specific area. "Significant

contribution" in this context is a

different concept than that in section

110(a)(2)(D) of the Act. Section

110(a)(2)(D) of the Act prohibits States

from emitting air pollutants in amounts

which significantly contribute to

nonattainment or other air quality

problems in other States. Consistent

with the previous discussion of sections

189(e) and 302(g), we are clarifying that

the use in this NSR implementation rule

of the term "significant contribution" to

the area's PM2.

5 concentration means

fhat a significant change in emissions of

the precursor from sources in the area

would be projected to provide a

significant change in PM2.5

concentrations in the area. For example,

if modeling indicates that a reduction in

an area's NOx emissions would reduce

ambient PM2.

5 levels in the area, but that

a reduction in ammonia emissions

would result in virtually no change in

ambient PM2.5 levels, this would suggest

that NOx is a significant contributor but

that ammonia is not. We are not

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establishing in this rule a quantitative

test for determining whether PM2 .5

levels in an aiea change significantly in

response to reductions in precursor

emissions in the area. However, in

considering this question, it is relevant

to consider that relatively small

reductions in PM2.

5 levels are estimated

to result in worthwhile public health

benefits.

This approach to identifying a

precursor as a regulated NSR pollutant

reflects atmospheric chemistry

conditions in the area and the

magnitude of emissions of the precursor

in the area. Assessments of whether it

is technically feasible and cost effective

to control particular emissions units at

a source should be part of the later

BACT determination within a permit

action, and should occur after the basic

assessment of which precursors are to

be regulated NSR pollutants in an area

is completed. I Most commenters did not question

our legal authority to identify and

regulate PM2.

5 precursors. However,

some commenters argued, based on the

language of sections 302(g) and 189(e) of

the Act, that once we have designated

a compound as a precursor, we do not

have discretion to presumptively

exclude it from NSR requirements.

Other commenters on this issue

indicated that we do have such

discretion, based on the de minimis

doctrine of the Alabama Power decision

or on practical implementation

considerations such as the uncertainty

in measuring and modeling the effect of

PM 2.

5 precursors.

We do not agree with the comment

that the Act does not give us discretion

to presumptively exclude a PM 2.

5

precursor from NSR requirements. As

stated previously, we believe that

section 302(g) allows the Administrator

to presumptively not require certain

precursors to be addressed in PM2.5 NSR

programs generally, while allowing the

State or EPA to make a finding for a

specific area to override the general

presumption. In the following pollutantspecific sections of this preamble, we find that at this time there is sufficient

uncertainty regarding whether certain

precursors significantly contribute to

PM 2.

5 concentrations in all areas such

that the policy set forth in this rule does

not presumptively require certain

precursors (ammonia, VOC) to be

controlled in each area. However, the

State or EPA may reverse the

presumption and regulate a precursor if

it provides a demonstration showing

that the precursor is a significant

contributor to PM2.

5 concentrations in

the area. In addition, if in the State's

NSR program adoption process a

commenter provides additional

information suggesting an alternative

policy for regulating a particular

precursor, the Stdte will need to

respond to this information in its

rulemaking action.

Hence, we continue to believe that the

Act provides us the authority not only

to identify and regulate precursors to

PM2.5, but also to treat precursors of the

same pollutant differently under the

same program.

3: Final Action on SO2

Sulfur dioxide is emitted mostly from

the combustion of fossil fuels in boilers

operated by electric utilities and other

industrial sources. Less than 20 percent

of SO 2 emissions nationwide are from

other sources, mainly other industrial

processes such as oil refining and pulp

and paper production. The formation of

sulfuric acid from the oxidation of SO 2

is an important process affecting most

areas in North America. There are three

different pathways for this

transformation.

First, gaseous SO 2 can be oxidized by

the hydroxyl radical (OH) to create

sulfuric acid. This gaseous SO2

oxidation reaction occurs slowly and

only in the daytime. Second, SO2 can,

dissolve in cloud water (or fog or

rainwater), and there it can be oxidized

to sulfuric acid by a variety of oxidants,

or through catalysis by transition metals

such as manganese or iron. If ammonia

is present and taken up by the water

droplet, then ammonium sulfate will

form as a precipitate in the water

droplet. After the cloud changes and the

droplet evaporates, the sulfuric acid or

ammonium sulfate remains in the

atmosphere as a particle. This aqueous

phase production process involving

oxidants can be very fast; in some cases

all the available SO 2 can be oxidized in

less than an hour. Third, SO 2 can be

oxidized in reactions in the particlebound water in the aerosol particles

themselves. This process takes place

continuously, but only produces

appreciable, sulfate in alkaline (dust, sea

salt) coarse particles. Oxidation of SO 2

has also been observed on the surfaces

of black carbon and metal oxide

particles. During the last 20 years, much

progress has been made in

understanding the first two major

pathways, but some important questions

still remain about the smaller third

pathway. Models indicate that more

than half of the sulfuric acid in the

eastern United States and in the overall

atmosphere is produced in clouds.

The sulfuric acid formed from these

pathways reacts readily with ammonia

to form ammonium sulfate, (NI) 2SO 4.

If there is not enough ammonia present

.to fully neutralize the produced sulfuric

acid (one molecule of sulfuric acid

requires two molecules of ammonia),

part of it exists as ammonium bisulfate;

NH4HSO4 (one molecule of sulfuric acid

and one molecule of ammonia) and the

particles are more acidic than

ammonium sulfate. In certain situations

(in the absence of sufficient ammonia

for neutralizatibn), sulfate can exist in

particles as sulfuric acid, H 2 80 4.

Sulfuric acid often exists in the plumes

of stacks where SO 2, sulfur trioxide

(SOs), and water vapor are in much

higher concentrations than in the

ambient atmosphere, but these

concentrations become quite small as

the plume is cooled and diluted by

mixing.

Because sulfate is a significant

component (e.g., ranging from 9 percent

to 40 percent) of PM2.5 concentrations,

and contributes to other air quality

problems in all regions of the country,

we proposed to require States to treat

SO2 as a PM2.

5 precursor in all areas. We

are retaining the same approach for SO2

in this final rule. Sulfate is an important

precursor to PM2 .

5 formation in all areas,

and has a strong regional impact on

PM2.

5 concentrations. This apprbach is

consistent with past EPA regulations,

such as the Clean Air Interstate Rule

(CAIR), the Clean Air Visibility Rule,

the Acid Rain rules, and the Regional

Haze rule, each of which require SO 2

reductions to address fine particle

pollution and related air quality

problems. Finally, we do not believe

that regulating SO 2 as a precursor to

PM2.

5 is likely to add a major burden to

sources, as S02 is already regulated as

part of the NSR program for the SO 2

NAAQS.

Most commenters who addressed this

issue agreed that SO 2 should be

regulated as a PM2.

5 prQcursor, although

one only supported regulation of SO2 as

a precursor in NA NSR, and not under

PSD. Two commenters disagreed that

SO 2 acts as precursors to PM2.

5 in all

cases and indicated that it should not be

regulated as an "always-in" precursor.

We find the commenters' arguments

against regulating SO 2 as a precursor

unpersuasive. Sulfate is a significant

fraction of PM2 5 mass in all

nonattainment areas currently, and

although large SO 2 reductions are

projected from electric generating units

with the implementation of the CAIR

program, sulfate is still projected to be

a key contributor to PM2 .

5

concentrations in the future, in both

attainment and'nonattainment areas.

Sulfur dioxide emissions also lead to

sulfate formation on both regional and

local scales.

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4. Final Action on NOx

The sources of NOx are numerous and

widespread. The combustion of fossil

fuel generates the majority of NOx

emissions, with large contributions from

power generation and mobile sources.

Nitrates are formed from the oxidation

of NOx into nitric acid (HN0 3 ) either

during the daytime (reaction with OH)

or during the night (reactions with

ozone and water). Nitric acid

continuously transfers between the gas

and the condensed phases through

condensation.and evaporation processes

in the atmosphere. However, unless it

reacts with other species (such as

ammonia, sea salt, or dust) to form a

neutralized salt, it will volatilize and

not be measured using standard PM2 .

5

measurement techniques. The formation

of aerosol ammonium nitrate is favored

by the availability of ammonia, low

temperatures, and high relative

humidity. Because ammonium nitrate is

semivolatile and not stable in higher

temperatures, nitrate levels are typically

lower in the summer months and higher

in the winter months. The resulting

ammonium nitrate is usually in the submicrometer particle size range.

Reactions with sea salt and dust lead to

the formation of nitrates in coarse

particles. Nitric acid may be dissolved.

in ambient aerosol particles.

Based on a review of speciated

monitoring data analyses, it is apparent

that nitrate concentrations vary

significantly across the country. For

example, in some southeastern

locations, annual average nitrate levels

are in the range of 6 to 8 percent of total

PM2 .5 mass, whereas nitrate comprises

40 percent or more of PM2 .5 mass in

certain California locations. Nitrate

formation is favored by the availability

of ammonia, low temperatures, and high

relative, humidity. It is also dependent

upon the relative degree of nearby SO 2

emissions because ammonia reacts

preferentially with SO 2 over NOx.

Reductions in NOx emissions are

expected to reduce PM2 .5 concentrations

in most areas. However, it has been

sfiggested that in a limited'number of

areas, NOx control would result in

increased PM 2.5 mass by disrupting the

ozone cycle and leading to increased

oxidation of SO 2 to form sulfate

.particles, which are heavier than nitrate

particles.

Because of these factors, we are

finalizing our proposed approach to

NOx as a precursor to PM2.5 for the NSR

program. Under this approach, NOx is

presumed to be a significant contributor

to ambient PM2.5 concentrations in all

PSD and NA NSR areas. However, a

State or'EPA may rebut this

presumption for a specific area if the

State demonstrates to the

Administrator's satisfaction or EPA

demonstrates that NOx emissions in that

area are not a significant contributor to

that area's ambient PM2.

5

concentrations. If a State or EPA makes

such a demonstration, NOx would not

be considered a PM2.5 precursor under

the NSR program in that area. If a State

or EPA does not make such a

demonstration, NOx must be regulated

as a precursor under the PSD, NA NSR,

and minor source programs for PM2.5.

As discussed previously, this "presumed-in" approach is warranted

based on the well-known transformation

of NOx into nitrates, coupled with the

fact that nitrate concentrations vary

significantly around the country. This

approach is consistent with other recent

EPA regulations requiring NOx

reductions, which will reduce fine

particle pollution, such as the CAIR and

a numbei of rules targeting onroad and

nonroad engine emissions.

We had proposed that NOx be

presumed to be a precursor in any State

that EPA has identified as a source of

the PM2 .

5 interstate transport problem.

In the final rule, we have dropped this

requirement to be consistent with EPA's

Clean Air Fine Particle Implementation

Rule published on April 25, 2007. 72 FR

20586. Such a requirement is not

necessary in this rule because States

that contribute to downwind

nonattainment for PM2.

5 are otherwise

required to address transported NOx

emissions under the CAIR.

In areas where NOx is regulated as a

precursor to PM2.

5, we do not believe

that this is likely to add a major burden

to sources, as NOx is already a regulated

NSR pollutant. This is because NOx is

an identified precursor for the ozone

NAAQS and an indicator for the NO2

NAAQS.

Several commenters agreed that NOx

should be regulated under major NSR as

a precursor to PM2.5. Some of these

commenters believe that States should

not have the opportunity to demonstrate

otherwise, or indicated that a waiver for

exclusion of NOx as a precursor should

be allowed only if downwind States

approve such a waiver. A few

commenters stated that NOx should not

be regulated as a precursor to PM 2.5 in

the major NSR program, either on

grounds of scientific uncertainty

regarding the impact of NOx emissions

on ambient PM2.

5 concentrations or on policy grounds (i.e., because NOx is

already regulated under NSR for other

NAAQS).

We are not persuaded by the

argument that NOx should not be

regulated as a PM2.5 precursor because

it is a regulated pollutant under other

NAAQS. We do not find the degree of

scientific uncertainty regarding PM 2.

5 formation from NOx to be great enough

to preclude regulation of NOx as a

precursor with an opportunity for a

case-by-case demonstration that NOx is

not a significant contributor.

Furthermore, the fact that we regulate

NOx for other NAAQS under the NSR

program does not by itself justify

declining to regulate NOx as a PM2.5

precursor in circumstances where NOx

also significantly contributes to PM2.

5 formation. As noted earlier, the

regulation of NOx as a precursor for

PM 2.5 is not expected to add a major

burden to regulated sources that are

already required to limit NOx emission

to meet other NAAQS.

We disagree with the commenters

who believe that emissions of NOx

cannot be correlated to PM2.5 formation,

or that it is unclear when NOx acts as

a precursor. As discussed previously, our decision to regulate NOx as a

precursor to PM2.5 is based on the wellknown transformation of NOx into

nitrates. Nevertheless, nitrate

concentrations vary significantly across the country. As a result, we believe that

the "presumed-in" approach is

appropriate-for NOx since a State can

demonstrate that NOx should not be a precursor in a given area or region.

While we recognize that NOx

emissions can affect PM2.

5 - concentrations in downwind areas, we

disagree that approval from downwind

States should be required'for a State to

exclude NOx as a PM2.

5 precursor for a particular area. This is because States

that contribute to downwind

nonattainment for PM2.

5 are otherwise

required to address transported NOx

emissions under the CAIR.

5. Final Action on VOC

The organic component of ambient

particles is a complex mixture of

hundreds or even thousands of organic

compounds. These organic compounds are either emitted directly from sources

(i.e., primary organic aerosol) or can be

formed by reactions in the ambient air

(i.e., secondary organic aerosol, or SOA). Volatile organic compounds are key precursors in the formation

processes for both SOA and ozone. The

relative importance of organic

compounds in the formation of

secondary organic particles varies from area to area, depending upon local

emissions sources, atmospheric

chemistry, and season of the year. - The lightest organic molecules (i.e.,

molecules with six or fewer carbon

atoms) occur in the atmosphere mainly as vapors and typically do not directly

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form organic particles at ambient

temperatures due to the high vapor

pressure of their products. However,

they participate in atmospheric

chemistry processes resulting in the

formation of ozone and certain free

radical compounds (such as OH) which

in turn participate in oxidation

reactions to form SOA, sulfates, and

nitrates. These VOCs include all alkanes

with up to six carbon atoms (from

methane to hexane isomers), all alkenes

with up to six carbon atoms (from

ethene to hexene isomers), benzene, and

many low-molecular weight carbonyls,

chlorinated compounds, and

oxygenated solvents.

Intermediate weight organic

molecules (i.e.,-compounds with 7 to 24

carbon atoms) often exhibit a range of

volatilities and can exist in both the gas

and aerosol phase at ambient

conditions. For this reason they are also

referred to as semivolatile compounds.

Semivolatile compounds react in the

atmosphere to form SOA. These

chemical reactions are accelerated in

warmer temperatures, and studies show

that SOA typically comprises a higher

percentage of carbonaceous PM in the

summer as opposed to the winter. The

production of SOA from the

atmospheric oxidation of a specific VOC

depends on four factors: Its atmospheric

abundance, its chemical reactivity, the

availability of oxidants (ozone, OH,

HNO3), and the volatility of its products.

In addition, recent work suggests that

the presence of acidic aerosols may lead

to an increased rate of SOA formation.

Aromatic compounds such as toluene,

xylene, and trimethyl benzene are

considered to be the most significant

anthropogenic SOA precursors and have

been estimated to be responsible for 50

to 70 percent of total SOA in some

airsheds. Man-made sources of

aromatics gases include mobile sources,

petrochemical manufacturing, and

solvents. Some of the biogenic

hydrocarbons emitted by trees are also

considered to be important precursors of

secondary organic PM. Terpenes (and bpinene, limonene, carene, etc.) and the

sesquiterpenes are expected to be fiajor

contributors to SOA in areas with

significant vegetation cover, but

isoprene is not. Terpenes are very

prevalent in areas with pine forests,

especially in the southeastern United

States. The rest of the anthropogenic

hydrocarbons (higher alkanes, paraffins,

etc.) have been estimated to contribute

5 to 20 percent to the SOA

concentration depending on the area. The contribution of the primary and

secondary components of organic

aerosol to the measured organic aerosol

concentrations remains a complex issue.

Most of the research performed to date

has been done in southern California,

and more recently in central California,

while fewer studies have been

completed on other parts of North

America. Many studies suggest that the

primary and secondary contributions to

total organic aerosol concentrations are

highly variable, even on short time

scales. Studies of pollution episodes

indicate that the contribution of SOA to

the organic PM can vary from 20 percent

to 80 percent during the same day.

Despite significant advances in

understanding the origins and

properties of SOA, it remains probably

the least understoQd component of

PM2.

5. The reactions forming secondary

organics are complex, and the number

of intermediate and final compounds

formed is voluminous. Some of the best

efforts to unravel the chemical

composition of ambient organic aerosol

matter have resulted in quantifying the

concentrations of hundreds of organic

compounds representing only 10 to 20

percent of the total organic aerosol

mass. For this reason, SOA continues to

be a significant topic of research and

investigation.

Current scientific and technical

information shows that carbonaceous

material is a significant fraction of total

PM2.

5 mass in most areas, that certain

VOC emissions are precursors to the

formation of SOA, and that a

considerable fraction of the total

carbonaceous material originates from

local as opposed to regional sources.

However, while significant progress has

been made in understanding the role of

gaseous organic material in the

formation of organic PM, this

relationship remains complex. We

recognize that further research and

technical tools are needed to better

characterize emissions inventories for

specific VOC, and to determine the

extent of the contribution of specific

VOC to organic PM mass.

As a result, this final rule does not, in

general, require regulation of VOC as a

precursor to PM2.5 for the NSR program.

However, a State may demonstrate to

the Administrator's satisfaction or EPA

may demonstrate that VOC emissions in

a specific area are a significant

contributor to that area's ambient PM2 .

5

concentrations. After such a

demonstration, the State would regulate

VOC (or a subset of VOC) as a PM2 .

5

precursor for the NSR program in that

area. That is, the State would need to

regulate construction and modification

of stationary sources that increase

emissions of VOC in that area to assure

that these emissions do not interfere

with reasonable further progress or the

ability of that area to attain Or maintain

the PMi.5 NAAQS.

We believe that this "presumed-out"

approach is appropriate for VOC

because of the complexity in assessing

the role of VOC in PM2.5 formation, as

discussed previously. Where the effect

of a pollutant's emissions on ambient

PM 2.5 concentrations is subject to this

degree of uncertainty, we do not have

justification to establish a nationallyapplicable presumption that the

pollutant is a regulated NSR pollutant

subject to the requirements of NSR for

PM 2.5. Under the circumstances, we

believe the best policy is to continue to

regulate VOC under NSR as a precursor

to ozone in all areas, which will

potentially provide a co-benefit for

PM2.5 concentrations despite the

uncertainty in PM2.5 formation from

VOC. As discussed previously, we do

not find it appropriate to utilize the

same approach for NOx because the

scientific data and modeling analyses

provide more certainty that NOx

emissions are a significant contributor

to ambient PM2.5 concentrations.

Note that we intend to regulate high

molecular weight VOC (with 25 carbon

atoms or more and low vapor pressure)

as direct PM2.5 emissions because they

are emitted directly as primary organic

particles and exist primarily in the

condensed phase at ambient

temperatures. See section V.E following

for more on the regulation of such

"condensables."

Most commenters agreed with the

"presumed-out" approach for VOC. One

commenter gaid that the role of VOC in

the formation of PM2.5 is sufficiently

understood to recommend a "waiver"

approach for this pollutant in the same

way as NOx is treated for PM 2.

5 in the

rule.

As discussed previously, the reactions

forming secondary organics are complex

and the number of intermediate and

final compounds formed is voluminous.

Some of the best efforts to unravel the

chemical composition of ambient

organic aerosol matter have merely been

able to quantify the concentrations of

hundreds of organic compounds

representing only 10 to 20 percent of the

total organic aerosol mass. For this

reason, SOA continues to be a

significant topic of research and

investigation. Accordingly, we do not

agree with the commenter who

suggested a waiver or "presumed-in"

approach for VOC. We continue to

believe that our "presumed-out"

approach is most appropriate for VOC

and have included this approach in the

final iules.

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6. Final Action on Ammonia

Ammonia (NH 3) is a gaseous pollutant

that is emitted by natural and

anthropogenic sources. Emissions

inventories for ammonia are considered

to be among the most uncertain of any

species related to PM. Ammonia serves

an important role in neutralizing acids

in clouds, precipitation, and particles.

In particular, ammonia neutralizes

sulfuric acid and nitric acid, the two key

contributors to acid deposition- (acid

rain). Deposited ammonia also can

contribute to problems of eutrophication

in water bodies, and deposition of

ammonium particles may effectively

result in acidification of soil as

ammonia is taken up by plants. The

NARSTO Fine Particle Assessment 8

indicates that reducing ammonia

emissions where sulfate concentrations

are high may reduce PM 2.5 mass

concentrations, but may also increase

the acidity of particles and

precipitation. An increase in particle

acidity is suspected to be linked with

adverse human health effects and with

an increase in the formation of

secondary organic compounds. Based

on this information and further insights

gained from the NARSTO Fine Particle

Assessment, it is apparent that the

formation of particles related to

ammonia emissions is a complex,

nonlinear process.

Though recent studies have improved

our understanding of the role of

ammonia in aerosol formation, ongoing

research is required to better describe

the relationships between ammonia

emissions, PM concentrations, and

related impacts. The control'techniques

for amnionia and the analytical tools to

quantify the impacts of reducing

ammonia emissions on atmospheric

aerosol formation are both evolving.

Also, area-specific data are needed to

evaluate the effectiveness of reducing

ammonia emissions on reducing PM2.

5

concentrations in different areas, and to

determine where ammonia decreases

may increase the acidity of particles and

precipitation.

Due to the considerable uncertainty

related to ammonia as a precursor, our

final rules do not require ammonia to be

regulated as a PM2.5 precursor but do

give States the option to regulate

ammonia as a precursor to PM2.

5 in

nonattainment areas for purposes of

NSR on a case-by-case basis. Consistent

with our proposal, if a State

8 NARSTO (2004) "Particulate Matter Assessment

for Policy Makers: A NARSTO Assessment." P.

McMurry, M. Shepherd, and J. Vickery, ads.

Cambridge University Press, Cambridge, England.

ISBN 0 52 184287 5. See the docket for this

-rulemaking, Docket ID No. EPA-HQ-OAR-2003-

0062, or http://www.narsto.org/section.src?SID-6.

demonstrates to the Administrator's

satisfaction that ammonia emissions in

a specific nonattainment area are a

significant contributor to that area's

ambient PM2.5 concentrations, the State

would regulate ammonia as a PM2.5

precursor under the NSR program in

that nonattainment area. Once this

demonstration is made, ammonia would

be a "regulated NSR pollutant" under

NA NSR for that particular

nonattainment area, and the State would

need to regulate construction and

modification of stationary sources that

increase emissions of ammonia in that

area to assure that these-emissions do

not interfere with reasonable further

progress or the ability of that area to

attain or maintain the PM2.

5 NAAQS. In

all other npnattainment areas in that

State and nationally, ammonia would

not be subject to the NSR program. In

addition, the action of any State

identifying ammonia emissions as a

significant contributor to a

nonattainment area's PM 2.s

concentrations, or our approval of a

nonattainment SIP doing so, does not

make ammonia a regulated NSR

pollutant for the purposes of PSD in any

attainment or unclassifiable areas

nationally. This is consistent with our

proposal (70 FR 66036) and no

commenters took issue with the

proposal. We also retain the ability to

make a technical demonstration for any

area in a State, if appropriate, to reverse

the presumption and require ammonia

to .be addressed in that State's

nonattainment area plan.

We elected to finalize the proposed

approach because of continued

uncertainties regarding ammonia

emission inventories and the effects of

ammonia emission reductions.

Ammonia emission inventories are

presently very uncertain in most areas,

complicating the task of assessing

potential impacts of ammonia emissions

reductions. In addition, data necessary

to understand the atmospheric

composition and balance of ammonia

and nitric acid in an area are not widely

available, making it difficult to predict

the results of potential ammonia

emission reductions. Ammonia

reductions may be effective and

appropriate for reducing PM2.

5

concentrations in selected locations, but

in other locations such reductions may

lead to minimal reductions in PM2,5

concentrations and increased

atmospheric acidity. Research projects

continue to expand our collective

understanding of these issues, but at

this time we believe this case-by-case

approach for fionattainment areas is

appropriate given that there is sufficient

uncertainty regarding the impact of

ammonia emission reductions on PM2.5

concentrations in all nonattainment

areas. In light of these uncertainties, we

encourage States to continue efforts to

better understand the role of ammonia

in their fine particle problem areas.

Several commenters agreed with our "presumed-out" approach for anunonia.

One of these commenters recommended

that we recognize the role ammonia

plays in PM2.5 formation and develop a

policy to require the minimization and

mitigation of known emissions of

ammonia, while another suggested that

we require States to initiate

comprehensive ambient' air monitoring

networks to determine the extent of

local effects of ammonia.

Four commenters did not support

treating ammonia as a PM 2.5 precursor

under any circumstances. Three of-these

commenters stated that if EPA permits

States to demonstrate that ammonia

should be regulated as a PM 2.5 precursor

for NSR purposes, we should make clear

that ammonia emissions from the

operation of an air pollution control

system to control NOx should not factor

into such a demonstration.

Two commenters preferred that we

use the "presumed-in" approach for

ammonia, as for NOx. One of these

commenters stated that the "presumedout" approach would improperly

delegate our authority to regulate

ammonia as a PM2.5 precursor to the

States and would reverse Congress'

requirement to regulate PM precursors

unless the emissions are not part of the

problem, instead taking the approach

that we will "not regulate unless proven

to be part of the problem."

We continue to believe that the

"presumed-out" approach is most

appropriate for ammonia. As discussed

previously, considerable uncertainties

remain regarding ammonia emission

inventories and the effects of ammonia

emission reductions. As a result, we do

not believe it advisable to adopt a "presumed-in"_ approach. However,

where a State can gather sufficient data

to demonstrate that reductions in

ammonia emissions will decrease

ambient concentrations of PM2.

5 in a

particular nonattainment area, we

believe that the State should be allowed

to regulate ammonia emissions under its

PM 2.5 NSR program for that area. , We do not believe that this approach

improperly delegates authority to the

States. The final rule establishes a

general presumption for all

nonattainment areas through this

rulemaking process, and allows for the

presumption to be modified by the State

on a case-by-case basis with EPA

approval. Under the Clean Air Fine

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Particle Implementation Rule (72 FR

20586, April 5, 2007). (addressing

various nonattainment plan elements

other than NSR), we still retain the

ability to make a technical

demonstration for any area if

appropriate to reverse the presumption

and require ammonia to be addressed in

its nonattainment area plan. As

discussed previously in section V.A.1,

we interpret the Act to allow the "presumed-out" approach adopted in

the final rule.

We agree with the commenter who

suggested that we continue research on

the role of ammonia in the formation of

PM 2.5. We believe that it is prudent to.

continue research on ammonia control

technologies and'the ammonia-sulfatenitrate-SOA equilibrium before

undertaking a broad national program to

reduce ammonia emissions. As we

develop a greater understanding about

the potential air quality effects of .

reducing ammonia emissions in specific

nonattainment areas, it may be

appropriate for ammonia reduction

strategies to be included in future SIPs.

At this time, however, we believe that

reducing S02 and NOx emissions will

achieve significant reductions in

ambient PM2 5 concentrations.

Regarding the comment related to

ammonia emissions from NOx control

systems, we believe that a State should

evaluate all sources of ammonia

emissions when determining whether to

regulate ammonia under its PM2.5 NSR

program for a particular nonattainment

area. However, we also encourage States

to be mindful of the potential tradeoff in

terms of ambient PM2.

5 concentrations

that may be related to reducing

ammonia emissions from NOx control

systems.

B. Major Stationary Source Threshold

for PM 2 .

5

The major NSR program applies to

construction of major stationary sources

and major modifications at major

stationary sources. A stationary source

is a "major source" if its actual

emissions or its potential to emit for a.

specific pollutant equals or exceeds the

major source threshold for that pollutant

established in the Act. Different

pollutants, including precursors, are not

summed to determine applicability.

, Sections 169 and 302(j) of the Act

contain definitions of "major emitting

facility" and "major stationary source"

that apply to programs implemented

under part C and subpart 1 of part D of

the Act (PSD and NA NSR,

respectively). Consistent with our

proposal, these final rules follow these

definitions for purposes of defining a

major emitting facility or.major ;

stationary source that would be subject

to major NSR. The thresholds set out in

the definitions are applied to each

relevant pollutant individually, that is,

to direct PM2.5 emissions and to

emissions of each pollutant identified as

a PM2 .

5 precursor for the applicable NSR

program. Under the final rules, the

inajor source thresholds are as follows:

PSD ............. 100 tpy for source categories

listed in 40 CFR

51.166(b)(1)(i)(a) and

52.21 (b)(1)(i)(a).

250 tpy for all other source

categories.

NA NSR ...... 100 tpy for all source categories.

No regulatory change is required to

implement this approach to the major

source thresholds for direct PM2 .

5

emissions and the PM 2.5 precursors. See

"40 CFR 51.165(a)(1)(iv)(a),

51.166(b)(1)(i), 52.21(b)(1)(i), and part

51, appendix S, section II.A.4.

This approach is consistent with'how

we treat other criteria pollutants that are

covered by subpart 1 of part D of the

Act. Nonattainment NSR programs

under subpart 1 do not include a tiered

classification system such as the one

required for ozone nonattainment areas

under subpart 2 of part D. We do not

interpret subpart 4 of part D of the Act

(creating "serious" and "moderate"

classifications for PM10 nonattainment

areas) as applying to PM 2.5. • Although our approach is consistent

with sections 169 and 302(j) and subpart

1 of part D of the Act, it results in a

higher major source threshold in PM2.5

nonattainment areas than the major

source threshold that applies in some

PM10 nonattainment areas under subpart

4 of part D of the Act. This is because

section 189(b) of the Act establishes a

70-tpy major source threshold for

"serious" PM 10 nonattainment areas

while "moderate" PM 0 nonattainment

areas apply a 100-tpy major source

threshold based 6n the definition in

section 302(j). We do not believe the Act

gives us the discretion to promulgate a

lower major source threshold for

pollutants such as PM2 .5 that are only

subject to subpart 1 of part D of the Act.

Our emissions inventory data do not

indicate that this situation will

adversely impact attainment of the

PM2 .

5 NAAQS. These data indicate that

a significant number of sources have

actual PM2.

5 emissions in the 100 to 250

tpy range. Additionally, our more

current inventory data show that the

number of sources that would be

covered as major sources by a lower

major source threshold would not

increase substantially unless thd

threshold were lowered to 20 tpy or

below. Thus, even if EPA had the

discretion to adopt a 70-tpy major

source threshold for PM2 .

5

nonattainment areas, our data indicate

that few additional sources would be

subject to the major NSR program in

PM2.5 nonattainment areas. 9

We believe that States should

consider such information in

developing their own SP-approved NSR

programs. For example, if construction

of PM2.

5 sources emitting 99 tpy with no

major NSR controls and without

mitigation would undermine a State's

ability to achieve reasonable further

progress or attain the PM2.

5 NAAQS, the

State should consider imposing

emissions controls or other

requirements on these sources through

the State's minor NSR program. Note

that such programs are required under

the existing statute and regulations to

assure that the NAAQS are achieved.

See section 110(a)(2)(C) of the Act and

40 CFR 51.160. In addition, States may

address such sources through other

elements in their nonattainment area

SIPs that are not statutorily bound to the

definition of major source, as the major

NSR program is. We reiterate that since

we do not interpret subpart 4 of the Act

to apply to PM2.5, we do not believe that

we have discretion under section 302(j)

of the Act to define a lower major source

threshold for pollutants such as PM2.5

that are only subject to subpart 1 of part

.D of the Act.

Some commenters indicated that State

minor NSR programs would not be

sufficient to address such sources due to

interstate transport and the existence of

interstate PM2.

5 nonattainment areas.

These commenters indicated -that a

lower major source threshold for PM2.5

sources located in designated

nonattainment areas should be applied

uniformly throughout the entire

nonattainment area, which would not be.

possible when minor NSR programs are

defined on a State-by-State basis.

We believe, to the contrary, that States

can coordinate their minor NSR

programs to address interstate PM2.

5

nonattainment areas, and we encourage

them to do so. In addition, we note that

the impacts of direct PM 2.

5 emissions

are generally felt primarily in the local

area.

One commenter stated that in order to

address the impact of high PM

concentrations, the Act mandates EPA

to define a criteria pollutant's NSR

major threshold at levels less than 100

tpy. The commenter gave the example of

9 See "NEI-PM2 _5 Source Analysis" in the docket

for this rulemaking, Docket ID No. EPA-HQ-OAR2003-0062.

I

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Federal Register / Vol. 73, No. 96/Friday, May 16, 2008 / Rules and Regulations

subparts 2 and 4 of part D of the Act,

which define lower major source

thresholds for certain classifications of

ozone and PMo nonattainment areas,

respectively. The commenter argued

that it is unreasonable for us to assert

that subpart 4 does not apply to this rlle

because it regulates all PM with a

diameter of less than 10 micrometers,

which includes PM2.

5. The commenter

believes that we recognized as much in

our proposal preamble discussion of the

options for implementing reasonably

available control technology (RACT),

where we discussed potential "

approaches that "would be consistent

with the approach set forth in the Act

in subpart 4." 70 FR 66017.. This

commenter stated that a reasonable

interpretation of the Act requires major

sources- of direct PM2 .

5 emissions and

precursor emissions to be defined at a

baseline level of 70 tpy, and adjusted

further downward as appropriate

considering the characteristics and

potential impacts of the pollutants.

We do not agree that subpart 4 of part

D applies t0 PM2.

5 nonattainment areas.

Subpart 4 was added to the Act by

Congress specifically to address the

PM1o NAAQS. We believe that the PM2.

5

standard should be implemented under

subpart 1 of part D, which is the general

provision of the Act related to NAAQS

implementation. Part D of title I of the

Act sets forth the requirements for SIPs

needed to attain the NAAQS. Part D also

includes a general provision under

subpart 1, which applies to all NAAQS

for which a specific subpart does not

exist. Because the PM2.5 standards were

not established until 1997, the

nonattainment plan provisions found in

section 172 of subpart 1 apply. Subpart

4 on its face applies only to the PM10

standard. In general, the emphasis in

subpart 4 on reducing PM1o

concentrations -from certain sources of

direct PM2.5 emissions can be somewhat

effective in certain PM 2.5 nonattainment

areas but not in all. Contributions to

PM2.5 concentrations are typically from

a complex mix of sources of primary

emissions and sources of precursor

emissions, which form particles through

reactions in the atmosphere. In addition,

PM 2.5 differs from PM1 o in terms of

atmospheric dispersion characteristics,

chemical composition, and contribution

from regional transport.

A group of environmental

commenters believed that EPA should

be consistent with the stationary source

size thresholds proposed for RACT in

option 2, see 70 FR 66019/1. In our

proposal preamble discussion of RACT,

while we discussed developing a

classification system for PM 2.5

nonattainment areas under section

172(a)(1) of subpart 1, we did not

discuss subjecting PM2.

5 to the

requirements of subpart 4. While our

discussion of RACT contemplated a

lower threshold for RACT applicability

in' some PM2.

5 nonattainment areas, we

did not characterize this as defining a

lower major source threshold. Moreover,

section 302(j) defines a major stationary

source as one that emits 100 tpy or more "except as otherwise expressly

provided." Since section 172 does not

expressly provide EPA with the

authority to promulgate a major source

threshold below 100 tpy, we do not

believe we are authorized to do so under

subpart 1 of part D of the Act.

One commenter stated that the major

source threshold for PM2.

5 emissions

should be calculated using the current

SO 2 and NOx definitions of major

source and significant emissions rate..

Specifically, the commenter suggested

that the ratio of these values (100 tpy

and 40 tpy, respectively) should be

multipfied by the significant emissions

rate for direct PM 2.5 emissions (10 tpy;

see section V.C following) to yield a

PM 2.5 major source threshold of 25 tpy.

As previously stated, we do not

believe that we have discretion under

the Act to define a lower major source

threshold under subpart 1 of part D of

the Act. In any case, the major source

thresholds and significant emissions

rates for SO 2 and NOx were not defined

in relation to one another, and therefore

their relationship would not provide a

suitable basis for developing the PM?. 5

major source threshold from the PM2.

5

significant emissions rate. Major source

thresholds are defined directly in the

Act, while the significant emissions

rates were codified independently in

regulations through a modeling analysis

of ambient impacts.

C. Significant Emissions Rate for Direct

Emissions of PM2.

5

The determination of what should be

classified as a modification subject to

major NSR is based, in part, on a "significant emissions rate." 10 The

major NSR regulations define this term

as a rate above which a net emissions

increase will trigger major NSR

permitting requirements, if the increase

results from a major modification.

Sources are exempt from major NSR

requirements if the emissions increase

resulting from a modification is below

this rate because EPA considers such

lower emissions increases to be de

minimis for purposes of the major NSR

program.

The significant emissions rates for the

criteria pollutants other than PM 2.5 are

given in the following table:

Criteria pollutant Significant emissions rate (tpy)

Ozone ................................................................. VOC: Any increase up to 40 tpy (dependent on NA classification).

NOx: Any increase up to 40 tpy (dependent on NA classification).

NO2 ..................................... ..... ..... .... ..... ..... ..... ... NOx: 40 tpy.

Particulate Matter ............................................. 25 tpy, particulate matter emissions.

15 tpy, PM 1o emissions.

CO ................................. 50 or 100 tpy (dependent on NA classification).

S02 ..................................................................... 40 tpy.

Lead .................................................................... 0.6 tpy.

Significant emissions rates for

additional (non-criteria) pollutants that

are subject to the PSD program are

contained in 40 CFR 51.166(b)(23).and

40 CFR 52.21(b)(23).

For direct ,emissions of PM2 .5, these

final rules define the significant

t0 For additional background on EPA's

interpretation of modification and rationale for

emissions rate as 10 tpy. This is the

level that we proposed as our preferred

option. This final significant emissions

rate for direct PM2.

5 emissions is based

fundamentally on the same approach

that we used in setting the previous

including significant emissions rates in defining

significant emissions rates for PM

emissions and PM 0 emissions.

Historically, the original significant

emissions rate for PM (25 tpy of PM

emissions) was set using a modeling

analysis to determine the amount of PM

emissions that a source could emit that

major modifications, see 61 FR 38253-54 (Dec. 31,-

2002).

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Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

would be unlikely to cause ambient

impacts above 4 percent of the PM

NAAQS (measured as total suspended

particulate (TSP)). 11 Although a range of

source configurations can yield a wide

range of impacts per tpy of emissions,

our review of typical configurations of

major PM sources led us to the

conclusion that a major modification

that increased PM emissions by 25 tpy

or less would be unlikely to increase 24-

hour average concentrations of TSP by

more than 4 percent of the 24-hour TSP

NAAQS. Subsequently, when we set the

significant emissions rate for PM10 , we

adjusted the rate for PM emissions using

the ratio of the 24-hour PM1o NAAQS to

the 24-hour TSP NAAQS to derive the

PM10 significant emissions rate of 15

tpy. W6 used the ratio of 24-hour

NAAQS for this adjustment because that

NAAQS was controlling for both PM

and PM10 . We used a conceptually similar

methodology to derive the final PM2.5

significant emissions rate from the rate

for PM10 . However, because the 24-hour

NAAQS is not controlling for PM2.5, we

revised the methodology to take into

account the annual impact of emissions.

See the proposal preamble for

additional information on the

methodology we used to develop the

final significant emissions rate for direct

PM2.5 emissions (70 FR 66038).

Several commenters supported our

approach to setting the significant

emissions rate for direct PM2.

5 emissions

and the level (10 tpy) based on the same

methodology used for PM emissions and

PM10 emissions. Numerous other

commenters believe that our

rethodology was too conservative, and

suggested a significant emissions rate of

15 tpy. Two commenters suggested that

we use significant emissions rate of 5

tpy or less. Another commenter

suggested that we could "split the

"The EPA established the original NAAQS for

PM id terms of ambient concentrations of TSP (40.

CPR 51.100(ss)). Source applicability for PM was

.determined in terms of amounts of PM emissions

(40 CFR 51.100(pp)) from the affected source. In

1993, at 58 FR 31622 (see page 31629), EPA

eliminated TSP as the ambient indicator for

measuring compliance with both the NAAQS and

PSD increments. Thus, EPA no longer considers the

TSP ambient indicator to be a regulated NSR

pollutant. The EPA is currently evaluating whether

it remains appropriate- to consider PM as a "regulated NSR pollutant." There is no NAAQS for

TSP/PM, rather the standards address specific size

fractions of PM, namely PM1e and PM 2.

5. However,

PM emissions, based on in-stack measurements,

continue to be regulated under PSD because of the use of such emissions for evaluating compliance

under a variety of CAA section 111 new source performance standards (40 CFR part 60). Given the

regulatory changes and positions taken by EPA

since 1993, EPA is re-evaluating the implications

for PM emissions in the NSPS program (and other

air programs) and will act accordingly to clarify this

issue in the near-term.

difference," using an option that could

give States and companies some

flexibility: Modifications less than 5 tpy

of direct PM2.

5 emissions could be

considered de minimis; modifications

between 5 and 15 tpy of direct PM2.

5

emissions could choose to either

demonstrate less than a 4 percent

NAAQS increase or simply be subject;

and modifications with increases of 15

or more tpy of direct PM 2.

5 emissions

would be subject.

We agree with commenters who

indicated that we were correct in using

the same methodology for direct PM2 .5

that was used to set the significant

emissions rate for PM1J and PM

emissions. We do not agree that using

the same-level as PM1 o emissions (15

tpy) is warranted, given the

demonstrated health effects of PM2.5.

Neither do we agree that a significant

emissions rate of 5 tpy or less is

warranted. While our screening model

runs indicated that emissions increases

in this range at facilities with short

stacks can cause measurable increases

in ambient PM2.

5 levels, we do not

believe that facilities at the extremes.

should dictate the program for all

sources.

We do not agree that inclusion of

condensable emissions in future testing

and applicability determinations (see

section V.E) is grounds for increasing

the SER for direct PM2.

5 emissions. The

results of the modeling analysis that is

the basis for the SER of 10 tpy is not

affected by the nature of the direct PM2.

5

emissions (i.e., condensable or not).

We also do not agree that'the

proportions of primary and secondary

PM2.5 that comprise ambient PM2.5

concentrations is relevant to

determining the appropriate SER for

direct PM2.5 emissions. Following our

historic approach for PM and PM10 , we

based our analysis on determining the

size of a source of direct PM2.5

emissions that would be expected to

have an ambient impact of 4 percent or

more of the NAAQS. This relationship

holds true regardless of the origin of the

particles that make up the ambient

PM2.

5. The commenter's approach (i.e.,

carrying out the analysis based on onehalf of the NAAQS because primary

PM2.

5 makes up only one-half ofthe

ambient PM2.5)•implies that an increase

in ambient PM2.

5 concentrations due to

an increase in direct PM2.

5 emissions is

somehow automatically matched by a

like increase in the ambient

concentration of secondary PM2.

5. We

do not believe that this is a reasonable

approach.

D. Significant Emissions Rates for PM2.

5

Precursors

Consistent With the preferred option

in the proposal, we are setting

significant emissions rates for PM2 .

5

precursors at the levels for those

pollutants already included in major

NSR programs, as shown in the

following table:

Significant emissions PM2.5 rate (equal to or precursor exceeding)

S0 2 ........................... 40 tpy.

NO x .......................... 40 tpy.

VOC ..................... 40 tpy.

Ammonia .................. Adopted in SIP.

VOC is presumed not to be a

precursor to PM2 .

5 in any attainment or

unclassifiable area, unless the State

demonstrates to the Administrator's

-satisfaction or EPA demonstrates that

emissions of VOC from sources in a

specific .area are a significant

contributor to that area's ambient PM2.

5

concentrations. Any State making such

a demonstration would be required to

adopt the 40-tpy significant emissions

rate unless it demonstrates that a more

stringent significant emissions rate

(lower rate) is more appropriate.

For ammonia, States determining in

their SIPs that control of ammonia is a

necessary part of a PM2 .

5 control strategy

in a particular area must set the

significant emissions rate for ammonia.

Otherwise, according to the definition of "significant" in the PSD program, "any

emissions rate" would be considered

significant. See 40 CFR 51.166(b)(23)(ii).

One commenter stated that we- should

not leave it to States to set significant

emissions rates for ammonia. The

commenter argued that EPA's scientists

should shoulder this responsibility, and

the resulting significant emissions rate

should be subject to notice and

comment.

In the final rule, we are allowing

those States that determine in their SIPs

that control of ammonia is necessary to

set the significant emissions rate for

ammonia, based on the information

developed for each attainment

demonstration. At this time, we believe

this is more appropriate than EPA

setting a single, nationwide significant

emissions rate because of the different

role ammonia plays in the formation of

PM2 .

5 from one area to another, as well

as our still-evolving understanding of

the impact of reducing ammonia

emissions on ambient PM2 .5

concentrations. In dddition, we note that

the SIP revisions that States undertake

to add ammonia to their NA NSR

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programs are subject to notice and

comment rulemaking procedures.

Numerous commenters supported our

proposal to set significant emissions

rates for PM2.

5 precursors at the levels

already used'for other purposes in the

NSR program. One commenter indicated

that since roughly half or more of

ambient PM2.5 is derived from

precursors, 140 tpy would be an

appropriate significant emissions rate

for PM2.

5 precursor emissions. Another

commenter suggested a significant

emissions rate of 4 ipy for SO 2 and 2 tpy

for NOx, based on the percentage of

PM2.

5 that is typically derived from

these precursors and the ratios between

the existing significant emissions rates

for these pollutants and the SO 2 and

NO 2 annual NAAQS. Since the ambient

concentrations of PM2.5 vary across the

country and since significant emissions

rates have not been developed as a ratio

of the NAAQS, we do not believe that

the suggested approach is appropriate.

As discussed in the proposal, the use

of existifig significant emission rates

where the PM2,

5 precursor is also

regulated under NSR as a separate

criteria pollutant harmonizes the NSR

program for PM2.

5 with the NSR

programs for those other criteria

pollutants. This enables a source to

determine the NSR impacts of proposed

modifications by reference to a single

significant emissions rate for each

pollutant, and enables streamlining of

determinations regarding the applicable

control technology and analysis of air

quality impacts into a single and

comprehensive decision making process

for both PM2.

5 and other criteria

pollutants that also cover PM2.

5

precursors. This also follows precedent.

When ozone became a criteria pollutant,

EPA used the NOx significant emissions

rate from the NO2 program.

The burden imposed is not the only

factor to consider when setting the

significant emission rates for

precursors-the process for determining

the significant emission rates must also

take into account the accuracy and

certainty with which we can predict the

effect of the precursors on PM 2.

5

concentrations. It is difficult to

determine the ambient air quality effects

that result from a single source of

emissions of PM2.

5 precursors. There are

conservative screening models for

predicting impacts of large NOx and

SO2 sources on ambient PM2.

5

concentrations. We conducted a range of

modeling analyses to determine the

amount of PM2.5 precursor emissions -

needed to show an increase in ambient

PM2.

5 concentrations. These analyses

showed that precursor emissions

probably have some localized impacts,

but that most impact is farther

downwind as precursors have the time

to convert to PM2.5. In addition, the

modeling available at this time does not

provide sufficient information to

estimate impacts of emissions from

individual sources of ammonia and

VOC on ambient PM2

. 5 concentrations.

While we know that precursors

contribute to the formation of PM2 .

5 in

the ambient air, the degree to which

these individual precursors contribute

to PM2.5 formation in a given location is

complex and variable. There are

competing chemical reactions taking

place in the atmosphere, and

meteorological conditions play a

significant role in the size and

characteristics of particle formation. For

these reasons, we do not believe that we

have adequate data on the impacts of

precursor emissions from individual

sources to override the administrative

advantages of setting the significant

emissions rates for SO 2, NOx, and VOC

for purposes of the PM2.

5 NSR program

at the same levels that are already used

for other purposes in the major NSR

program.

E. Condensable PM Emissions

In this final NSR rule, EPA will not

require that States address condensable

PM in establishing enforceable

emissions limits for either PM 1o or PM2.

5

in NSR permits until the completion of

a transition period, as described herein.

In response to significant comments on

the variability of test methods available

for measuring condensable emissions,

we have adopted this transition period

approach to allow us to assess the

capabilities of the test methods and

possibly revise them to improve

performance. The transition period will

end January 1, 2011 unless EPA

advances this date through the

rulemaking process described below.

Subsequent to the completion of the

test methods assessment, EPA will be

conducting a notice and comment

rulemaking to codify new or revised test

methods. Once these new or revised test

methods are in place, States will have

the tools necessary to issue NSRpermits

addressing condensable PM. Thus, as

part of the test methods rulemaking, we

will take comment on an earlier closing

date for the transition period in the NSR

program if we are on track to meet our expectation to complete the test

methods rule much earlier than January

1, 201.1. In the meantime, however, we

are establishing January 1, 2011 as the

latest possible end date for the NSR

transition period because this is also the

end of the transition period for SIP

purposes as described in the Clean Air

Fine Particle Implementation Rule (see

section II.L in 72 FR 20586, April 25,

2007). Prevention of Significant

Deterioration and NA NSR permits

issued after the effective date of this

NSR implementation rule but prior to

the end of the transition period for the

NSR program are not required to

account for condensable emissions in "

PM2 .

5 or PM 10 emissions limits. After

January 1, 2011 (or any earlier date

.established in the upcoming rulemaking

codifying test methods), EPA will

require that NSR permits include limits

of condensable emissions, as

appropriate. Prior to this date, States are

not prohibited from establishing

emissions limits in NSR permits that

include the condensable fraction of

direct PM2.

5.

As noted in the proposal preamble,

certain commercial or industrial

activities involving high temperature

:processes (e.g., fuel combustion, metal•

processing, and process cooking

operations) emit gaseous pollutants into

the ambient air, some of which rapidly

condense into particle form. The

constituents of these condensed

particles include, but are not limited to,

organic materials, sulfuric acid, and

metals and metal compounds. We

consider such condensable emissions to

be a component of direct PM emissions.

Specifically, direct PM emissions

consist of both the "filterable fraction"'

which already exist in particle form at

the elevated temperature of the exhaust

stream, and the "condensable fraction"

which exist in gaseous form under

exhaust stream conditions but

condenses rapidly in the ambient air.

Because condensable PM emissions

exist almost entirely in the 2.5

micrometer range and smaller, these

emissions are inherently more.

significant for PM2.

5 than for prior PM

standards addressing larger particles.

Condensable PM emissions commonly

make up a significant component of

direct PM 2.5 emissions. Therefore, we

believe that it is important that the air

quality management of PM promote a

comprehensive approach to the control

of condensable PM.

We proposed on November 1, 2005 to

clarify that condensable PM emissions

must be included when determining

whether a source is. subject to the major

NSR program. We noted in the proposal

that our prior guidance 12 had clarified

that PMo includes condensable PM and

12 Leter from Thompson G. Pace, Acting Chief,

Particulate Matter Programs Branch, to Sean

Fitzsimmons, Iowa Department of Natural

Resources (Mar. 31, 1994) (available at http://

www.epa.govfRegion7/programs/artd/air

nsr.nsrmemos/cpm.pdf and in the docket for th.is

rulemaking, Docket ID No. EPA-HQ-OAR-2003-

0062).

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Federal Register / Vol. 73, No. 96 / Friday, May 16, 2008 / Rules and Regulations

that, where States expect condensable

PM emissions to be in higher amounts,

States should use methods that

appropriately measure condensable PM

emissions. In addition, we pointed out

that the 2001 consolidated emissions

reporting rule (CERR) requires States to

report condensable emissions in each

inventory revision (see 67 FR 39602,

June 10, 2001) and that Method 202 in

appendix M of 40 CFR part 51 quantifies

condensable PM. We also noted that

States have not applied this existing

guidance consistently.

We received a number of comments

on whether NSR programs should

account for condensable PM emissions

in. light of the current state of knowledge

of and uncertainties around the

measurement of direct PM2.

5. Several

commenters supported our proposal to

require the inclusion of condensable PM

emissions in NSR applicability

determinations. On the other hand,

several other commenters expressed

opposition to including condensables at

this time and raised concerns about the

availability and implementation of test

methods and related issues about the

uncertainties in existing data for

condensable PM 2.

5 . As a result of the

concerns, these commenters believed

EPA would be premature in requiring a

comprehensive evaluation of

condensable PM 2.

5, especially as it

related to developing any new

emissions limits for stationary sources. One commenter noted that regulation

of condensable PM at this time will

impede, rather than facilitate,

expeditidus attainment of the PM2.5

standard. Another commenter expressed

concern about the poteitial for

retroactive enforcement over

applicability decisions made in good

faith, and for retroactive application of

the new test method to assert violations

of an emission limit, where the

applicability decision or the emission

limit was originally based on flawed

testing/estimatilg methodology. Several

commenters raised serious concerns

about the availability and

implementation of accurate test

methods and emissions factors for

condensable PM2.

5. They further stated

that regulation of condensable PM2.5

emissions would be appropriate only

after we have developed a workable

transitional strategy that ensures

existing major sources are not placed in

"NSR jeopardy" for physical and

operational changes undertaken before

new test methods and other

-requirements for condensable PM2.

5 are

established.

In recognition of these concerns, both

as they apply to the NSR program and

the broader air program, we have

adopted a transition period during

which NSR permits need not address

limits of condensable PM2.5 emissions.

During this transition period, EPA will

undertake a collaborative testing effort

with industry, National Association of

Clean Air Agencies (NACAA), and other

stakeholders to assess and improve the.

effectiveness and accuracy of the

available or revised test methods. The

purpose of the stakeholder testing

projects will be to collect new direct

filterable and condensable PM2.

5

emissions data using methodologies that

provide data more representative of

sources' direct PM 2.

5 emissions. The

EPA, States, and others will use these

data to establish or improve emissions

factors and to define more

representative source emissions limits

in permits.

The EPA acknowledges the legitimate

concerns raised by commenters

concerning potential exposure to -

retroactive enforcement and has

established rules to address this issue.

The EPA will not revisit applicability

determinations made in good faith prior

to the end of the transition period,

insofar as the quantity of condensable

PM emissions are concerned, unless the

applicable implementation plan clearly

required consideration of condensable

PM. Likewise, EPA will interpret PM

emissions limitations in existing

permits or permits issued during the

transition period as not requiring

quantification of condensable PM2.

5 for

compliance purposes unless such a

requirement was clearly specified in the

permit conditions or the applicable .implementation plan. "

After the end of the transition period

(January 1, 2011 or any earlier date

established in the upcoming rulemaking

codifying test methods), EPA will

require that all NSR applicability

determinations for PM2 .

5 and PM1 o

address condensable emissions as

applicable, and the source may not rely

on calculations made for previous

determinations that did not include an

accurate accounting of condensables.

Additionally, compliance with these

limits must be determined using the

promulgated validated test methods that

are applicable after that date. Moreover,

after that date, we expect that

condensable PM emissions will be

addressed in all other aspects of the

major NSR program, such as impact

analyses under PSD and offsets under

NA NSR. See 72 FR 20586, April 25,

2007 for the discussion of the transition

period as it applies to the other

elements of the air program in the final

Clean Air Fine Particle Implementation

Rule.

Although EPA is not requiring that

State NSR programs address

condensable emissions of PM until the

end of the transition period, States that

have developed the necessary tools ae

not precluded from acting to measure

and control condensable PM emissions

in NSR permit actions prior to the end

of the transition period, especially if it

is required in an applicable SIP. To the

extent that a State has the supporting

technical information and test methods,

the State may assess the capabilities of

current control technologies, possible

modifications to such technologies, or -new technologies as appropriate relative

to control of condensable PM 2.5

emissions. As an example, a specific

approach for controlling condensable

PM could be a change in control device

operating temperature to improve

emissions reductions. We also note that

it is important that implementation of

any new or revised emissions limits and

test 'methods that account for

condensable emissions should be

prospective and clearly differentiated

from existing NSR permit requirements.

This will avoid confusion over the

compliance status relative to existing

PM emissions limits that were not

developed considering the condensable

portion.

Notwithstanding the issues and

uncertainties related to condensable

PM, we encourage States to begin

immediately to identify measures for

reducing condensable PM emissions in

major NSR permit actions, particularly

where those emissions are expected to

represent a significant portion of total

PM emissions from a sourceF. Prevention of Significant

Deterioration (PSD) Program

Requirements

To receive a permit for a new major

source or a major modification, sources

subject to PSD must:

* Install Best Available Control

Technology (BACT).

* Conduct air quality modeling to

ensure that the project's emissions will

not cause or contribute to either-

-A violation of any NAAQS or

maximum allowable pollutant

increase (PSD increment); or

-An adverse impact on any Class I area "air quality related value" (AQRV).

e As required, comply with

preconstruction monitoring

requirements.

This final action regarding each of these

elements is discussed in the following

sections.

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Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

1. How must BACT be implemented for

PM 2.

5?

- We are not making any change to our

current regulations or policy for

implementing BACT requirements at a

major source that is subject to the

requirements of the PSD program.

Accordingly, if a new major source will

emit, or have the potential to emit, a

significant amount of a regulated NSR

pollutant in an attainment area for that

pollutant, the source must apply BACT

for each emissions unit that emits the

pollutant. In addition, if a physical or

operational change at an existing major

source will result in a significant

emissions increase and a significant net

emissions increase of a regulated NSR

pollutant in an attainment area for that

pollutant, the source must apply BACT

to each proposed emissions unit

experiencing a net increase in emissions

of that pollutant as a result of the

physical or operational change in the

unit. Under the PM2.

5 PSD program,

these requirements will apply to direct

PM2.5 emissions; SO 2 emissions; NOx

emissions, unless a State demonstrates

that NOx is not a significant contributor

to ambient PM2.

5 concentrations in that

area; and to VOC if identified by a State

as a precursor in the PM2.5 attainment

area where the source is located.

2. How does EPA plan to address PM2.5

Increments, Significant Impact Levels

(SILs), and Significant Monitoring

Concentrations (SMCs)?

On November 1, 2005, we proposed a

rule to implement the PM2.

5 NAAQS,

including proposed revisions to the NSR

program (70 FR 65984). In that proposal,

we indicated our intent to propose a

separate rule for developing PM2.5

increments, SILs, and SMCs and sought

comments on general approaches for

developing these values. We proposed

PM2.

5 increments, SILs, and SMCs in a

rule dated September 21, 2007. 72 FR

54112. We intend to address comments

received on these components of the

PM2.

5 PSD program when we finalize

that proposed rule.

3. What is the ambient air quality

analysis requirement for PM2.5?

All sources subject to PSD review

must perform an ambient air quality

impact analysis to show that the

emissions from.the source will not

cause or contribute to a PSD increment

or NAAQS violation. See section

165(a)(3) of the CAA; 40 CFR 51.166(k)

and 52.21(k). We did not propose, and

our final rules do not contain, any

changes to the regulations on air quality

impact analyses for purposes of the

PM2.

5 NSR program. Accordingly,

sources will be required to perform this

analysis for the PM 2.

5 NAAQS and,

when finalized, PM2.5 increments. Such

analyses must consider how a source, in

combination with other sources in the

area, will impact air quality at existing

PM2.5 monitor locations, as well as at

other locations that are appropriate for

comparing predictcd PM2.

5

concentrations to the NAAQS based on

PM2.5 monitor siting requirements and

recommendations.

4. How must the PSD preconstruction

monitoring requirement be

implemented for PM2.

5?

Sources subject to PSD are subject to

preconstruction ambient air quality

monitoring requirements. See sections

165(a)(7) and 165(e) of the Act and 40

CFR 51.166(m) and 52.21(m). The PSD

permitting requirements provide that

continuous preconstruction ambient air

quality monitoring must be conducted

for any criteria pollutant emitted in

significant amounts. Under 40 CFR

51.166(i)(5) and 52.21(i)(5), the

reviewing authority has the discretion to

exempt an applicant from this

monitoring requirement if: o The maximum modeled

concentration for the applicable

averaging period caused by the

proposed significant emissions increase

(or net emissions increase) is less-than

the prescribed SMC; or o The existing monitored ambient

concentrations are less than the

prescribed SMC.

A source may also use existing data as

a surrogate for preconstruction

monitoring if the existing monitored

data record is determined to be

representative of the project's location.

We proposed five options for how to

address preconstruction monitoring for

PM2.5. We are adopting a combination of

options 1 and 3 from the proposal,

primarily because we believe that it

reflects existing procedures for other

regulated NSR pollutants. The following

sections summarize the major comments

received on each option and explain

why we are not adopting particular

options.

Option 1-Require Preconstruction

Monitoring for All Sources But Exempt

on a Case-by-Case Basis

Generally, commenters who

supported option I believed the option

gives regulatory agencies enough

flexibility to address sources with

unique characteristics. One

commentator stated that another benefit

is that this option would avoid

unnecessary installation of new PM2.5

monitors and redundant

preconstruction monitoring.

Another commenter, however,

believed option I to be overly

burdensome until EPA develops an

SMC. The commenter argued that for

example, there are many upcoming PSD

projects in their State, which would be

located in extremely remote areas where

there are no local or regional PM2.

5

emission sources, so there would be no

need to collect such data for these areas.

Additionally, one group of commenters

stated that option 1 appeared to be

"streamlining" preconstruction permit

requirements, which is not the intention

of the Act's PSD provisions, and that

EPA does not have the authority to

exempt sources from the requirements

of section 165(e)(2).

We agree with the "commenter that

recommended combining option 3 (the

use of a 24-hr PM2.5 SMC) with option

1 and are finalizing this approach. We

have proposed an SMC for PM2.5 in the

rulemaking on increments, SILs, and

SMCs (72 FR 54112, September 21,

2007). Our regulations at 40 CFR

51.166(i)(5) and 52.21(i)(5) have allowed

the use of an SMC as screening tool for

identifying when an impact is de

minimis and there is thus little or no

value in gathering preconstruction

monitoring data The use of de minimis

levels of this nature (such as significant

emission rates and significant impact

levels) is supported by court precedent

interpreting the NSR provisfons of the

Act. Alabama Power Co. v. Costle, 636

F.2d 323, 360 (DC Cir. 1979). ("Unless

Congress has been extraordinarily rigid,

there is likely a basis for an implication

of de minimis authority to provide [an]

exemption when the burdens of

regulation yield a gain of trivial or no

value.")

Option 2-Exempt All Sources From

Preconstruction Monitoring

Under option 2, we proposed to

exempt all PM2 .

5 sources from

preconstruction monitoring through a

* blanket determination that the existing

PM2.

5 monitoring network is sufficient.

One commenter who preferred option 5

(described subsequently) was also

supportive of option 2. This commenter

noted that preconstruction monitoring is

expensive and can significantly delay a

project. The commenter also pointed out

that it is very difficult to locate monitors

for both direct PM2.

5 and precursors

because precursors may transport over

long distances before transforming into

PM2.5. The commenter indicated that we

should not rely on the existing

regulations, which are already known to

be problematic.

One comment letter from a group of

environmental advocacy organizations

specifically opposed option 2. These

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Federal Register / Vol. 73, No. 96 / Friday, May 16, 2008 / Rules and Regulations

commenters noted that spatial gradients

can be significant for PM2.

5 , especially

for direct PM2.

5 emissions, and that the

existing monitoring network is severely

limited in its spatial coverage, most

especially in attainment areas where

PSD preconstruction monitoring

requirements apply. The commenters

indicated that to make a blanket

determination that the existing network

suffices for any source, regardless of

where it might choose to locate, would

be absurd.

We decided not to finalize option 2

because we do not believe that the

current network will be sufficient for all

existing and potential new sources. As

stated in the proposal preamble, we

believe that the existing PM 2.

5

monitoring record has the following

limitations:

* The PM 2.5-monitoring data record

would require spatial interpolation

between monitors for the determination

of appropriate concentrations at the

project's location.

* Use of existing monitored data will

not increase the PM 2.5 monitoring data

record to confirm or contradict

conventional perceptions.

* The PM 2.5 monitoring data record

assumes that local hot spots of high

PM2.

5 concentrations do not exist or are

already being monitored, which may not

be true in all cases. .* Automatic acceptance of existing

measurements does not follow our

current policy that a case-by-case

determination needs to be made to

determine whether preconstruction

ambient monitoring is necessary.

* When used with the impact

modeling, separate concentrations of

direct and precursor-formed PM are

needed.

Option 3-Use SMC's To Exempt

Sources From Preconstruction

Monitoring

Several commenters supported this

option adding that this approach

follows existing procedures to justify

the exclusion of preconstruQtion

monitoring requirements when source

impacts are less than the SMC or when

sufficient representative data exists. One

group of commenters stated that EPA's

proposed options 1 and 3, which would

allow case-by-case or de minimis

exemptions from the monitoring

requirements, are ill-conceived as a -

matter of public policy and contradict

the Act's PSD provisions.

We agree with the commenters that

support adopting option 3 because a

combination of options 1 and 3 reflects

existing procedures for other regulated

NSR pollutants. As discussed

previously, a de minimis exemption

from monitoring requirements is

supported by court precedent

interpreting the PSD provisions of the

Act. We do not consider it sound policy

to require gathering additional data

when it is unnecessary to demonstrate

that a proposed source or modification

will not adversely impact air quality.

Option 4-Use Existing PM10 Data

We proposed using the available large

PMo data record combined with the

recently acquired PM2.

5 data to provide

representative ambient measurements

for most sources: One comnient letter

from an industry group opposed any

requirement for preconstruction

monitoring, and endorsed option 4 if

nationally gathered PM2.5 data is not

available. Three commenters

specifically opposed option 4. One

comment letter from an environmental

advocacy organization stated that option

4 is illegal on its face, to the extent that

EPA intends it as a universally available

alternative. This comment indicated

that some individual sources might be

able to demonstrate that PM10

monitoring could fulfill the statutory

requirements and purposes of PM2.5

monitoring (e.g., with sufficiently

protective assumptions about PM2.

5/

PM1o proportions), but due to the

variability in the relationship between

PM2.

5 and PM10, EPA cannot

categorically allow this substitution.

Two other commenters stated that

option 4 was not a viable approach due

to the convoluted nature of attempting

to infer PM2.

5 concentration from PM10

monitoring data for source-specific

applications.

We decided not to finalize option 4.

As we recognized in the proposal

preamble, the differences in

characteristics between PM2.

5 and PM 0

and our limited understanding of their

relationship are problematic for this

application. We do not believe that

generalized factors to convert PM10

concentrations to PM2.

5 concentrations

sufficiently reflect important industryspecific and spatially-related

characteristics of PM2.5. In addition,

removing altogether the obligation to

provide preconstruction PM 2.

5 ambient

monitoring data would eliminate

industry's contribution to the PM2.

5 data

record when source impacts are more

than de minimis.

Option 5-Exempt Sources From

Preconstruction Monitoring if No SMC

Is Established

We noted in the proposed rule that

the existing regulations at 40 CFR

51.166(i)(5)(iii) and 52.21(i)(5(ii) could

be interpreted to allow a reviewing

authority to exempt an applicant from

preconstruction monitoring for any

pollutant for which we have not

established an SMC. These provisions

state that a source may be exempted

from preconstruction monitoring "if

* * * the pollutant is not listed in" the

list of pollutants for which SMC have

been set.1 3 The original rationale for this

exemption is based on the lack of

adequate methods for measuring

ambient concentrations of pollutants not

on the list. See 45 FR 52709, 52723-

52724. We r~quested comment on this

interpretation and any other legal or

policy rationale that could support

applying the text of these provisions to

exempt sources from preconstruction

monitoring-if we elected not to define

an SMC for PM2 .

5.

One commenter stated that option 5 is

the most practicable to implement until

an SMC can be established and any

potential gaps in the monitoring

network can be filled. Two commenters

question the legality of option 5 under

the Act. They added that whatever may

have been the case when the existing

list of SMCs was adopted, methods now

exist for conducting the monitoring

required under section 165(e)(2). We

decided not to finalize option 5, and

have proposed an SMC rule for PM2.5.

In conclusion, we are finalizing a

combination of options 1 and 3 from the

proposal, since we believe that it

reflects existing procedures for other

regulated NSR pollutants. Once we

finalize an SMC for PM 2.5, the reviewing

authority will have the discretion to

exempt a source frofh the

preconstruction monitoring requirement

if the projected PM2.

5 ambient impact of

the source is below the PM 2.5 level

promulgated in our rules. In addition,

additional preconstruction monitoring

data may not be necessary based on the

availability of existing representative

monitoring data in the area, as

discussed previously.

G. Nonattainment New Source Review

(NA NSR) Requirements

To receive a permit for a new major

source or a major modification, sources

subject to NA NSR must:

* Install Lowest Achievable Emission

Rate (LAER) control technology;

* Offset new emissions with

creditable emissions reductions;

13 These sections actually cross-reference the list

at 40 CFR 51.166(i)(8)(i) and 52.21(i)(8(i), however

we renumbered those paragraphs to paragraph

(i}{5)(i) of those provisions in the December 31,

2002 NSR reform rule and inadvertently overlooked

correcting the cross-references in paragraphs

(i)(5)(ii) and (il(5)(iii). See 67 FR 80186. As

proposed, in this final action we have corrected this

misnumbering and others in this section.

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* Certify that all major sources owned

or operated by the applicant in the same

State are in compliance; and

* Conduct an alternative siting

analysis demonstrating that the benefits

of the proposed source significantly

outweigh the environmental and social

costs.

We did not propose, nor are we

finalizing, any revisions to the first,

third, and fourth of these requirements.

Thus, these requirements apply for

purposes of PM2. 5 and its designated

precursors just as they apply for other

criteria pollutants and their designated

precursors. In the remainder of this

section G, we discuss our final actions

related to offsets for direct PM2.5

emissions and emissions of PM2 . 5

precursors.

1. What is the required offset ratio for

direct PM2.5 emissions?

Under section 173 of the Act, all

major sources and major modifications

at existing major sources within a

nonattainment area must obtain

emissions reductions to offset any

emissions increases resulting from the

project in an amount that is at least

equal to the emissions increase, aid that

is consistent with reasonable further

progress towards attainment. We refer to

the proportional difference between the

amount of the required offsets to the

amount of emissions increase as the "offset ratio."

The Act specifies an offset ratio for

several situations. In ozone

nonattainment areas subject to subpart 2

(of title I, part D of the Act), the ratio

is set between 1.1:1 and 1.5:1 depending

on the area's level of classification

pursuant to subpart 2. For other

nonattainment areas, the Act establishes

a minimum offset ratio of 1:1 pursuant

to subpart 1 of title I, part D of the Act.

As proposed, we are finalizing the

offset ratio for direct PM2.s emissions as

at least 1:1 on a mass basis because the

PM2.

5 program is being implemented

under subpart 1 of the Act. The

commenters on this issue generally

agreed that our regulations should

require an offset ratio of at least 1:1

pursuant to subpart 1.

A few commenters indicated that a

lower ratio could be acceptable on a

source-specific basis if accompanied by

a modeling analysis demonstrating a net

air quality benefit. One commenter

suggested that such a demonstration

would be possible when a direct PM2.5

emissions increase from a tall stack is

being offset by ground-level PM2.

5

emission reductions. Applying diesel

retrofit technology to bus and truck

fleets is an example of how ground-level

PM2 .s emission reductions could be

achieved. We do not believe that a lower

offset ratio is authorized under subpart

1, which prescribes an offset ratio of at

least 1:1, and therefore we have not

adopted this approach in our final rules.

Some of the commenters disagreed

regarding whether an offset ratio of at

least 1:1 under subpart 1 represents a

ceiling or a floor on the level we can

prescribe in our regulations. We

interpret section 173 of the Act to allow

higher offset ratios where necessary to

achieve reasonable further progress.

Accordingly, We believe that States may

establish higher offset ratios in their

State programs if they wish, but we do

not believe that it would be appropriate

for us to do so for PM2.s in national

regulations. We do not have cause to

believe a higher ratio is necessary for

PM2 . 5 in each area of the country and

prefer to leave this to the discretion of

States. We do not believe that the higher

offset ratios required for ozone

precursors under subpart 2 apply in any

way to direct PM2 .

5 emissions or PM 2.5

precursors.

2. Which precursors are subject to the

offset requirement?

-Consistent with our proposal, the

pollutants that are designated as PM2 .-

precursors- in a particular area are

subject to the offset requirement in that

area. Accordingly, SO 2 is subject to

offsets in all PM2 .5 nonattainment areas.

As a "presumed-in" precursor, NOx will

be subject to offsets unless a State

obtains an exemption for-its NSR

program through a demonstration that

NOx emissions in a particular area are

not a significant contributor to ttiat

area's ambient PM2 . 5 concentrations. As

"presumed-out" precursors, VOC and

ammonia would be subject to offsets

only in areas where the State has

demonstrated that these emissions are

significant contributors to the area's

ambient PM2.s concentrations. Two

commenters on this issue agreed with

this approach; one commenter

recommended that we not require

offsets for any PM2 5 precursors. We

believe that it is appropriate to offset

emissions increases of all precursors

that have been established to contribute

to the PM 2.s nonattainment problem in

a particular area.

3. What is the required offset ratio for

PM2 .5 precursors?

As discussed previously, the Act

requires that a source obtain offsets for

emissions increases that occur in a

nonattainment area. As with PM2.5

direct emissions, the minimum offset

ratio permitted under subpart 1 of the

Act is at least 1:1. Based on these

requirements of the Act, we are

finalizing our proposal that an offset

ratio of at least 1:1 applies where a

source seeks to offset an increase in

emissions of a PM2.

5 precursor with

creditable reductions of the same

precursor. This offset ratio applies for

all pollutants that have been designated

as PM2.5 precursors in a particular

nonattainment area.

Most commenters agreed with this

approach. A few commenters indicated

that an offset ratio of less than 1:1 for

precursor emissions of PM 2.5 should be

allowed only if there is a net air quality

benefit and if the lower ratio is justified

by air quality modeling analysis. They

noted that for PM2.5 precursors,

chemical reactivity modeling

demonstrations should be developed

and approved that are, at a minimum,

capable of determining the impacts of

the precursor emissions on tl~e air

quality in the nonattainment area in

which the source is located. As noted

previously, we do not believe that any

offset ratio less than 1:1 is permissible

under subpart 1.

One commenter stated that consistent

with the statutory scheme for ozone laid

out in section 182, and given the

severity of the health risks associated

with PM2.5, EPA must require offsets of

at least 1.15:1 for PM2 .s precursors in

"moderate" nonattainment areas, and

must increase the offset ratio in

"serious" nonattainment areas or in

areas that request extensions of their

attainment deadlines. As mentioned

previously, we do not believe that

subpart 2 of the Act (which includes

section 182) has any relevance to PM2 .5

or its precursors. Subpart 2 is specific to

ozone. In addition, we are implementing

the PM2 .5 program under subpart 1.

Nevertheless, under the Act, we believe

that a State may require higher offset

ratios if it determines that they are

necessary to achieve reasonable further

progress. For the reasons discussed

previously with respect to direct PM2 .

5 ,

we do not believe that it is appropriate

for us to set higher offset ratios for PM2.5

precursors on a national basis.

Two commenters requested that we

make clear in the final rule that an

increase in precursor emissions need

only be offset once, even if the increase

triggers nonattainment NSR under, for

example, both the ozone and PM2 .5

programs. We agree with these

commenters and are clarifying that a

precursor emissions increase only needs

to be offset once. A permit applicant

will not, for example, need to obtain

two sets of offsets for NOx emissions if

NOx is regulated as a precursor both for

ozone and PM2 .s in the area. The NOx

precursor emissions need only be offset

once in accordance with the applicable

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Federal Register/Vol. 73, No. 96/Friday, May 16, 2008 /Rules and Regulations

ratio. To the extent a higher ratio

applies for ozone under subpart 2, the

applicant would have to obtain offsets at

the higher ratio. However, when the

offset ratios are the same, both

requirements can be met with a single

set of NOx offsets.

4. Is interpollutant trading allowable to

comply with offset requirements?

In this final rule, we are allowing

limited interpollutant trading for

purposes of offsets only (and not

netting) under the PM2.5 NA NSR

program. Specifically, the final rules

allow interpollutant trading only based

on a trading ratio established in the SIP

as part of the attainment demonstration

approved for a specific nonattainment

area, on a statewide basis, or in a

regional, multi-state program. This

differs from our proposal in that the

final rules do not allow interpollutant

trading on a case-by-case basis as part of

an individual NA NSR permitting

process. For the purpose of offsets in the

NA NSR program for PM2.

5, the final

rules" allow reductions in direct PM2 .

5

emissions to offset precursor emissions

increases, emissions reductions of one

precursor to offset emissions increases

of another precursor, and reductions in

precursor emissions to offset direct

.PM 2.

5 emissions increases.

We have completed a technical

assessment to develop preferred

interpollutant trading ratios that may be

used for the purposes of PM 2.5 offsets,

where appropriate. The preferred ratios

were generated with a PM2.5 response

surface modeling (RSM) approach based

on the EPA's Community Multi-Scale

Air Quality (CMAQ) model. This RSM

approach allows one to distinguish the

impact of direct and precursor

emissions from particular source

groupings on total PM2.

5 concentrations

within nine specific urban areas and

broadly across U.S. regions. This

approach Was recently applied by the

Agency to inform development of

potential PM2 .s control strategies as part

of the Regulatory Impact Assessment

(RIA) for the final PM 2.5 NAAQS.1 4

Based on results from the RSM, we

determined the distribution of predicted

ratios for urban areas and regions across

the country and developed the preferred

ratios with a goal to be environmentally

protective. The technical approach with

details on data and modeling inputs are

fully described in a technical memo to

the docket, "Details on Technical

Assessment to Develop Interpollutant

14 A full description of this approach is available

in the technical support document at http://www.

epa.gov/scramool/repoils/pmnaaqs-tsd rsm -alL

021606.pdfand in the docket for this rulemaking,

Docket ID No. EPA-HQ-OAR-2003--0062.

Trading Ratios for PM2.s Offsets." 15 Use

of the preferred ratios is recommended

by EPA but not mandatory, and we do

not intend to preclude the opportunity

for a local demonstration of trading

ratios on a case-by-case basis and public

input into that process.

Our work here and in other recent

PM2.

5 assessments clearly show that the

relative efficacy of emissions reductions

varies across pollutants and that a ton

of direct PM2.5 is generally more

effective than a ton of precursor

emissions in reducing overall PM 2.

5

concentrations. For the purposes of

reporting information here, we define

the "East" to be the 37 States either

completely or in part east of 100 degrees

west longitude. "West" would include

the remaining 11 western-most States in

the continental United States. We found

the following relationships between

pollutants in developing the preferred

trading ratios:

1. NOx to S0 2 . S0 2 to NOx: Our

assessment indicated potential disbenefits of

reducing NOx (i.e.,. reducing NOx tons in

urban areas may increase overall PM2.5

concentrations) in the eastern United States

and urban areas in the western United States.

Due to the possibility of these disbenefits and

the high degree of variability in the observed

NOx to SO 2 ratios or SO2 to NOx ratios across urban areas, we are not defining preferred

ratios involving trades between these

precursors but will rely upon a local

demonstration to determine the appropriate

trading ratios.

2. NOx to Primary PM2 .5; Primary. PM2.5 to

NOx: Based on a local demonstration that

NOx reductions are beneficial in reducing

PM 2.

5 concentrations (i.e., no disbenefits from

NOx reductions as noted previously), our assessment indicates that the preferred -

trading ratio is 200 to 1 (NOx tons for PM2 .

5

tons) or 1 to 200 (PM2.

5 tons for NOx tons)

for areas in the eastern United States, and

100 to 1 (NOx tons for PM 2.

5 tons) or 1 to 100

(PM2 .

5 tons for NOx tons ) for areas in the

western United States.

3. SO 2 to Primary PM 2.s; Primary PM2 .

5 to

SO2 : We have determined a nationwide

preferred ratio of 40 to 1 (SO 2 tons for PM 2_5

tons) or.1 to 40 (PM 2 .s tons for SO 2 ) for trades

between these pollutants. We recognize there

is spatial variability here between urban and

regionally located sources of these pollutants

that can be addressed through a local

demonstration to detqrmine an area-specific

relationship, as appropriate.

We recommend that States hse thiese

hierarchies and trading ratios in their

interpollutant trading programs to

provide consistency and streamline the

trading process. As indicated by our

work and findings, it is appropriate to

establish acceptable trading ratios for

interpollutant trading for PM2:5 NSR

offsets. If States elect to'use EPA's

15 Available in the docket for this rulemaking,

Docket ID No. EPA-HQ-OAR-2003-0062.

recommended trading ratios, they may

rely on EPA's technical work and a

presumption that such ratios will be

approvable by EPA absent a credible

showing that EPA's trading ratios are

not appropriate for that location. If

States choose to develop thEir own

hierarchies/trading ratios, they will

have to substantiate by modeling and/or

other technical demonstrations of the

net air quality benefit for PM 2.

5 ambient

concentrations, and such a trading

program will have to be approved by

EPA.

We acknowledge that the relationship

between pollutants can vary across

geographic areas. Thus, local

demonstrations, to determine trading

ratios, will need to address a number of

local factors including, but not limited

to, the following:

1. The relative magnitude of emissions of

direct PM2.

5 and precursor gases (e.g., SO 2

and NOx) within the geographic area of

interest.

2. The relative contribution to local PM2.5

nonattainment of directly emitted PM2.

5 and

individual precursors from the various

sources or source categories under

consideration as part of a potential

interpollutant trade.

3. The meteorological conditions and

topography of the area, which result in

different source-receptor relationships across

pollutants within the local area.

We.have adopted this approach to

capture the flexibility advantages.of

interpollutant trading, while remaining

mindful of the limitations of existing air

quality models. We believe that the

regional-scale models used for areawide attainnient demonstrations have

sufficient accuracy to establish an

overall equivalence ratio for a

nonattainment area. However, we do not

believe that available models can

accurately determine the effects of

interpollutant trades'at a single source.

In addition, permit-by-permit modeling

demonstrations are extremely resource

intensive, dnly to yield limited results.

For these reasons, the final rules only

allow a State to develop its own

interpollutant trading rule for inclusion

in its SIP, based on a technical

demonstration for a specific

nonattainment area. We will not accept

case-by-case demonstrations on an

individual source permit basis.

The flexibility provided by this policy

allows sources to select the most costeffective manner to obtain the offsets

necessary to ensure that PM2.

5 air

quality improves. This will be

particularly beneficial where offsets for

one particular pollutant are scarce in a

particular area, as is often the case for

direct PM2 .

5 emissions and SO 2.

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Federal Register/Vol. 73, No. 96/Friday, May 16, 2008/Rules and Regulations

We received a large number of

comments on this issue representing a wide variety of viewpoints. Several

commenters supported flexible

interpollutant trading at ratios

established either on an area-wide basis

or permit by permit. They often pointed

out the economic and administrative

benefits of flexibility in the program,

especially in areas where offsets for

some pollutants will be difficult to

obtain. One commenter asserted that

such flexibility is essential to the ability

of enterprises to be able to expand as the

PM2.

5 NAAQS is implemented,

especially in the program's early years.

Another commenter suggested allowing

such trading on an equal basis, without

the "unnecessary complication" of

interpollutant offset ratios.

Many commenters argued against

allowing interpollutant trading for

offsets. These commenters commonly

pointed out that direct PM2.5 emissions

typically have a more local impact,

while the impact of precursor emissions

are farther afield. A number of

commenters pointed out the complex

atmospheric chemistry of secondary

particulate formation and the

shortcomings of the air quality models

currently available to perform a.detailed

PM2.

5 formation assessment, specifically

that local-scale. models are not

sufficiently accurate and regional-scale

models do not have the resolution to

show local impacts adequately.

According to two commenters, trading

precursors for direct PM2.5 emissions

raises serious environmental justice

concerns due to the localized impacts of

direct PM2 .s emissions. These

commenters also asserted that the

equivalence between precursors would

vary spatially and temporally, making it

extremely difficult to assess, and that

PM2.

5 precursors also differ in their

impacts on other air pollution problems,

such as direct health and welfare

impacts of SO 2 and NOx; and formation

of ozone, acid deposition, and reactive

nitrogen deposition.

We also received comments opposing

allowing interpollutant trading for

netting purposes, on the basis that the

resulting program would be very staffintensive apart from the difficulty of

demonstrating through modeling the net

air quality benefit of a single source

trade. We concur with these

commenters and are not allowing

interpollutant trading for netting

purposes at this time.

A number of commenters supported

some types of trades, but not others.

Most frequently, these commenters

favored allowing reductions in direct

PM2.

5 emissions to offset precursor

emissions increases. One commenter

suggested a hierarchy as follows: Direct

PM2.5 emissions, S02, NOx, ammonia,

and VOC. That is, a pollutant should be

allowed as an offset for a pollutant

ranked lower, but not the-reverse (e.g.,

reductions in direct PM2.

5 emissions

could be used to offset increases in any

of the listed pollutants, SO 2 emissions

reductions could offset NOx increases,

etc.).

As previously noted, this rule allows

interpollutant and interprecursor

trading of offsets according to a SIPapproved trading program. To be

approved, the trading program must

either adopt EPA's recommended

trading ratios or be backed up by

regional-scale modeling that

demonstrates a net air quality benefit

using appropriate overall offset ratios

for such trades for a specified

nonattainment area, State, or multi-State

region. There is considerable

uncertainty about the relationship of

precursor and direct PM2 .5 emissions to

localized ambient PM2.

5 concentration

both spatially and temporally. Given the

uncertainty as tO localized adverse and

beneficial effects, we have opted for

program flexibility. We believe this is

necessary, in part, because of the

shortage of available offsets for some

pollutants, particularly direct PM2.5

emissions and SO 2, in many areas.

H. How will the transition to the PM2.

5

PSD requirements occur?

1. Background

On October 23, 1997, after the

NAAQS for PM2.

5 was originally

promulgated, we issued a guidance

document entitled "Interim

Implementation for the New Source

Review Requirements for PM2.

5," John

S. Seitz, EPA. As noted in that guidance,

section 165 of the Act suggests that PSD

requirements become effective for a new

NAAQS upon the effective date of the

NAAQS. Section 165(a)(1) of the Act

provides that no new or modified major

source may be constructed without a

PSD permit that meets all of the section

165(a) requirements with respect to the

regulated pollutant. Moreover, section

165(a)(3) provides that the emissions

from any such source may not cause or

contribute to-a violation of any NAAQS.

Also, section 165(a)(4) requires BACT

for each pollutant subject to PSD

regulation.

The 1997 guidance stated that sources

should continue to use implementation

of a PM1o program as a surrogate for

meeting PM2.

5 NSR requirements until

certain difficulties were resolved,

primarily the lack of necessary tools to

calculate the emissidns of PM2.

5 and

related precursors, the lack of adequate

modeling techniques to.project ambient

impacts, and the lack of PM2 .

5 ' monitoring sites. With this final action

and technical developments in the

interim, these difficulties have largely

been resolved.

2. Transition for "Delegated States"

The Federal PSD program is

contained in 40 CFR 52.21. This section

is the Federal implemeritation plan for

areas lacking an approved PSD program.

We implement this program in Indian

country and some U.S. territories, but

for the most part we have delegated

implementation of 40 CFR 52.21 to

those States without approved PSD

programs (typically referred to as

"delegated States;'). Except as provided

in the grandfathering provisions that

follow, these final rules go into effect

and must be implemented beginning on

the effective date of this rule, July 15,

2008 in all areas subject to 40 CFR

52.21, including the delegated States.

Consistent with 40 CFR 52.21(i)(1)(x),

wherein EPA grandfathered sources or

modifications with pending permit

applications based on PM from the PM1o

requirements established in 1987, EPA

will allow sources or modifications who

previously submitted applications in

accordance with the PMo surrogate

policy to remain subject to that policy

for purposes of permitting if EPA or its

delegate reviewing authority

subsequently determines the application

was complete as submitted. This is

contingent upon the completed permit

application being consistent isith the

requirements pursuant to the EPA

memorandum entitled "Interim

Implementation of New Source Review

Requirements for PM2.

5" (Oct. 23, 1997)

recommending the use of PM 0 as a surrogate for PM2.

5. Accordingly, we

have added 40 CFR 52.21(i)(1)(xi) to

reflect this grandfathering provision.

3. Transition for "SIP-Approved States"

The requirements for State PSD

programs are contained in 40 CFR

51.166. Most States have developed PSD

programs according to these

requirements, which we have approved

into each State's implementation plan.

States with PSD programs approved

under 40 CFR 51.166 are called "SIP--

approved States."

States with SIP-approved PSD

programs that require amendments to

incorporate these final NSR rule

changes for PM2.

5 will need time to

accomplish these SIP amendments. For

example, a State may need to amend its

existing regulations to add the specific

significant emissions rate for PM2.

5 or a designated precursor. In our December

31, 2002 Federal Register notice

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Federal Register / Vol. 73, No. 96/Friday, May 16, 2008 / Rules and Regulationspromulgating other changes to the NSR

program, we explained that the Act does

not specifically address the timeframe

by which States must submit SIP

revisions when we revise the PSD and

NA NSR rules. W6nonetheless looked

.to section 110(a)(1) to guide our

decision to require States to adopt and

submit plan revisions within 3 years

from when we publish changes in the

Federal Register. We codified this

approach in the PSD regulations at 40

CFR 51.166(a)(6)(i) and applied this

same timeframe to State NA NSR

programs through that final rule action.

.64 FR 80241. This rule follows our

established approach for determining

when States must adopt and submit

revised SIPs following changes to the

NSR regulations, but does not revise

otherwise applicable SIP submittal

deadlines. Accordingly, we are

requiring States with SIP-approved PSD

programs to submit revised PSD

programs and revised NA NSR programs

for PM2.5 (see section V.I.) within'3

years from the date of this action.1 6

During this SIP development period,

the PM2.5 NAAQS must still be

protected under the PSD program in

such States. We are finalizing our

proposed option 1 that if a SIP-approved

State is unable to implement a PSD

program for the PM2.5 NAAQS based on

these final rules, the State may continue

to implement a PM1o program as a

surrogate to meet the PSD program

requirements for PM2.5 pursuant to the

1997 guidance mentioned previously.

Under option 1 for SIP-approved States,

we had proposed two additional

requirements. These were to require

sources to demonstrate that emissions

from constiuction or operation of the

facility will not cause or contribute. to a

violation of the PM2.5 NAAQS'and to

include condensable PM emissions in

6

1n our proposal, we proposed April 5, 2008 as a deadline for States to comply with the revised

nonattainment NSR and PSD requirements in this

rule. However, in light of the time it has taken to

complete this final rule, expecting States to submit

required SIP revisions consistent with this final rule

by April 5, 2008 is no longer practical or fair.

Nevertheless, States are still cugrently required to

implement a PSD program for PM2.s, and we still

expect States to fulfill the SIP infrastructure

requirements of CAA section 110(a)(2), including

the PSD program requirements, by April 5, 2008.

We believe these PSD program requirements are

currently met by implementing the transitional PSD

program for PM2.

5 described in this preamble (ak..a.

the PM10 surrogate policy). In accordance with a

Consent Decree in Environmental Defense and

American Lung Ass'n v. Johnson, No. 1:05CV00493

(D.D.C. June 15, 2005), EPA must determine by

October 5, 2008 whether each State has submitted

the SIP revisions for the PM2.5 PSD program

required under section 110(a)(2) of the Act. This

rulemaking does not change the specific guidance

we previously provided to States on what they

should submit by April 5, 2008 to comply with

section 110(a)(2).

determining major NSR applicability

and control requirements. We are not

finalizing either of these additional

requirements of our proposed option 1.-

We have dropped the requirement for

demonstrating compliance with the

PM 2.5 NAAQS in order to maintain

consistency in the application of the

existing surrogate policy across the PSD

program during the interim period.

Since in the final rule we are otherwise

allowing SP-approved States to

continue with the existing PM10

surrogate policy to meet the PSD

requirements for PM2.

5, partially

implementing the PM1o surrogate policy

in this manner would be confusing and

difficult to administer. Thus, to ensure

consistent administration during the

transition period, we have elected to

maintain our existing PM1o surrogate

policy which only recommends as an

interim measure that sources and

reviewing authorities conduct the

modeling necessary to show that PM~o

emissions will not cause a violation of

the PM1o NAAQS as a surrogate for

demonstrating compliance with the

PM2.5 NAAQS. Also as discussed

previously in section V.E, we are not

requiring condensable emissions to be

fully integrated into the PM2.5 program

until the end of the transition period to.

validate test methods discussed in

section V.E of this preamble.

In our proposal, we offered two

additional option for the SIP

development period in-States with SIPapproved PSD programs. Under option

2, we would have updated the 1997

guidance to reflect the provisions in

these final rules and allowed States to

run a PM2.

5 program pursuant to this

updated guidance. Alternatively under

option 2, we would have amended

appendix S and 40 CFR 52.24 so that the

PSD requirements of 40 CFR 52.21

would govern the issuance of major NSR

permits during the SIP development

period. Finally, under option 3, we

would have allowed a State to request

delegation of just the Federal PM2.

5 PSD

program in 40 CFR 52.21 in that State.

A State that otherwise had a SIPapproved PSD program could have

requested delegation for PM2.s by

informing us that it did not intend to

submit a PSD SIP for PM2.5 in the

immediate future.

We received several comments

supporting option 1, although some of

these commenters requested that we not

require condensable emissions to be

included until the c6ncerns with test

methods were resolved. One of these

commenters favored continuing to

implement the PMmo program as a

surrogate under the 1997 guidance to

provide clarity and certainty to the

permitting agency and regulated

community. The commenter indicated

that PM2.

5 inventories and methods for

estimating emission rates are

rudimentary and may even be

nonexistent in some.cases, which would

nmke permitting onerous.

A few commenters opposed option 1.

One of these commenters indicated that

we should not continue outdated policy

(i.e., the 1997 NSR guidance) because it

does not address'the PM2.

5 problem,

cannot be implemented in some States,

and does not incorporate precursor

emissions.

Four commenters expressed support

for option 2. Three of these suggested

that we issue updated guidance to

incorporate these PSD requirements for

PM2.

5, while one preferred that we

revise appendix S to point to the

requirements of 40 CFR 52.21. We

received one comment in favor of option

3 and three-opposed.

Two commenters supported

approaches different from our options.

One of these commenters requested that

the interim framework should, at a

minimum, ensure that any new or

modified project that exceeds thresholds

use BACT. The commenter also

-suggested that we require offsets for

projects approved before the other

protective elements of the full PSD

program are in place to ensure that there

is no significant deterioration in air

quality. Another commenter stated that

none of the proposed options were

viable for their State. The commenter

requested that we allow States to

continue their existing PMo program as

a surrogate for PM2.5, without caveat.

As noted previously, we are finalizing

proposed option 1, without the

requirement of demonstrating

compliance with the PM2s NAAQS or

the requirement to include condensable

emissions. We believe that our final rule

is reasonable for the following reasons.

First, PMio will act as an adequate

surrogate for PM2.

5 in most respects,

because all new major sources and

major modifications that would trigger

PSD requirements for PM2.5 would also

trigger PM1o requirements because PM2.s

is a subset of PM10 . Second, both of the.

precursors designated in the final ruleSO 2 and NOx (presumptively)-are

already regulated under State NSR

programs for other criteria pollutants.

Thus, those precursors will be subject to

NSR through those other programs. We

do not believe that the other options or

suggestions offer significant advantages

that outweigh the utility and ease of

implementation of this approach.

States may include grandfathering

provisions similafto the ones EPA

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included in the transition requirements

for 40 CFR 52.21.

L How will the transition to the PM2.

5

NA NSR requirements occur?

1. Background

The requirements for State NA NSR

programs are contained in 40 CFR

51.165. All States with nonattainnent

areas have developed NA NSR program

according to these requirements, which

we have approved into each State's

implementation plan. However, as

noted previously, it takes time for a

State to amend its SEP when it must

make changes to its NA NSR program.

According to the provisions of 40 CFR

52.24(k), during such an interim period

when a State lacks an approved NA 1IS

program for a particular pollutant,

appendix S of 40 CFR part 51 applies ft

NA NSR permitting.'

Section 172(c)(5) of the Act requires

that States issue major NSR permits for

construction and major modifications o

major stationary sources in any

nonattainment area. Thus, since the

PM2.

5 nonattainment designations

became effective on April 5, 2005, StatE

are now required to issue major NSR

permits that address the section 173 NY

NSR requirements for PM2.5.

On the date that the PM2.

5

nonattainment designations took effect

(April 5, 2005), we issued guidance to

address implementation of the NA NSR

program pending the completion of thi,

action to develop implementation rules

for PM2.

5. See memorandum from

Stephen D. Page, Director, Office of Air

Quality Planning and Standards to

Regional Air Directors, "Implementatio

of New Source Review Requirements in

PM2.

5 Nonattainment Areas" (April 5,

2005).

Our current guidance permits States

to implement a PM1o NA NSR program

as a surrogate to address the

requirements of NA NSR for the PM2.

5

NAAQS. A State's surrogate major NSR

program in PM2.5 nonattainment areas

may consist of either the

implementation of the State's SIPapproved NA NSR program for PM1 o or

implementation of a major NSR prograr

for PM10 under the authority in 40 CFR

part 51, appendix S.

2. Transition

With this finalization of the new

PM 2.5 NSR implementation

requirements under 40 CFR 51.165,

States now have the necessary tools to

implement a NA NSR program for PM2.

After the effective date of the amended

rule (that is, July 15, 2008, States will

no longer be permitted.to implement a

NA NSR program for PM1o as a surrogat

for the PM2.

5 NA NSR requirements.

Most States will then need to implemeni

a transitional PM2.5 NA NSR program

under appendix S (as amended in this

rulemaking action) until EPA approves

changes to a State's SIP-approved NA

NSR program to reflect the new

requirements under 40 CFR 51.165. At

this time, we do not believe it is

s appropriate to allow grandfathering of

pending permits being reviewed under

the PM10 surrogate program in

nonattainment areas, mainly because of

a State's obligations to expedite

attainment and the fact that we had not

established a similar precedent for

transitioning from PM to PMio.

The NA NSR provisions in a State's

R existing SP-approved NA NSR program

would also apply in areas designated as

)r nonattainment for the PM2.5 NAAQS if

the SP-approved regulations contain a

generic requirement to issue part D

permits in areas designated as

f nonattainment for any criteria pollutant

and do not otherwise need to be

amended to incorporate the changes

finalized in this action. States belonging

!s to the following categories will need to

revise their NA NSR regulations and

submit them to EPA for incorporation

into the SIP within 3 years from the datc

of this action 17:

* States that have nonattainment

regulations which need to be amended

to incorporate the new PM2.

5

requirements.

* States that have designated

nonattainment areas for PM2.5 and their

nonattainment NSR regulations

specifically list the areas in which NA

n NSR applies (i.e., the list does not

include the designated nonattainment

areas for PM2.

5).

* States that have not previously had

nonattainment areas but now have

nonattainment areas for PM2.5;

These States will have to implement

a transitional NA NSR permitting

program for PM2.5 pursuant to 40 CFR

52.24(k) and appendix S until their

existing part D SlPs are revised to meet

17 As discussed earlier, we are following the

precedent we established in our 2002 rule for NA

n2 NSR program revisions to allow States adequate

time to adopt these revisions. For practical and

fairness reasons, we are not requiring the NA NSR

elements of this rule to be submitted by April 5,

2008, as we had proposed. However, the States are

still required to submit nonattainment plans for

PM2 .

5 (including NA NSR programs) on April 5,

2008. We believe this requirement is satisfied by

implementing the transitional NA NSR program for

PM2.5 (a.k.a. the PM,Q surrogate policy) described in

our April 5, 2005 guidance, or, if submitted after

5. the effective date of this rule, implementing

Appendix S as revised in this rule. This rulemaking

does not change the specific guidance we

previously provided to States on what they should

submit to EPA by April 5, 2008 to comply with

.e nonattainment area requirements under Part D.

these new PM2.5 NSR requirements

t under 40 CFR51.165.

3. Implementation of NSR Under the

"Emissions Offset Interpretative Ruling"

(40 CFR Part 51, Appendix S) With

Revisions

In general, appendix S requires new

or modified major sources to meet LAER

and obtain sufficient offsetting

emissions reductions to assure that a

new major source or major modification

of an existing major source will not

interfere with the area's progress toward

attainment. Readers should refer to

appendix S for a complete

understanding of these and other

appendix S requirements. In this action,

we are finalizing our proposed revisions

to appendix S to include provisions

necessary to implement a transitional

NA NSR program for PM2.

5 , including

significant emissions rates applicable to

major modifications for PM 2.

5 and, as

appropriate, precursors. Additionally,

since we are finalizing interpollutant

trading provisions in the NSR rules at

40 CFR 51.165, we are also amending

appendix S to allow interpollutant

trading for PM2.

5 . Appendix S applies

directly to new and modified major

stationary sources. In accordance with

the requirements of section 110(a)(2)(c)

of the Act, we believe that the majority

of States have the legal authority to

issue permits consistent with these

requirements under an existing SIPapproved permitting program.

Nonetheless, at least one State has

reported that it lacks the legal authority

to issue permits implementing the

requirements of appendix S under its

existing permitting rules.

If a State is unable to apply the

requirements of appendix S, we will act

as the reviewing authority for the

relevant portion of the permit. We

-believe that it is appropriate for EPA to

issue the preconstruction permits in

such circumstances. Congress amended

the Act in 1990 to remove the

requirements that would have applied a

construction ban in areas that lacked a

SIP-approved part D permit program.

Thus, we believe that it is consistent

with Congressional intent that either the

State or EPA issues construction permitsfor those projects meeting the applicable

criteria during the interim period. See

the preamble of the proposal for this

rule for more detail on the legal basis for

requiring States to issue NA NSR

permits pursuant to appendix S during

the SIP development period (70 FR

66045-46).

We received three comments

supporting the issuance of NA NSR

permits under appendix S during the.

SEP development period. Two of these

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commenters expected States generally to

be able to do so, while one suggested

that EPA issue such permits because

States will lack the authority to do so

without protracted rule revisions. One

of these commenters also suggested that

we revise appendix S to authorize

interprecursor trading during the

transition period, believing that the

paucity of existing direct PM2.

5

emissions and SO 2 offsets likely will

make business expansion in PM2 .

5

nonattainment areas from now until at

least April 2008 impossible unless this

is done. One commenter suggested that

we suspend the 2005 PM2.

5 NSR

guidance which allows use of PM 1o.

emissions'as a surrogate for PM2.5

emissions in PM 2.

5 nonattainment areas

when we adopt the final PM2.5

implementation rules, while three other

commenters requested continued

implementation of that guidance during

the interim period.

As noted previously, this final action

will require States to amend their NA

NSR programs consistent with the

amended rules at 40 CFR 51.165. During

the SIP development period, where they

have legal .authority to do so, States

must issue NA NSR permits under

appendix S (as revised for purposes of,

the PM2 .5 program). To address one of

the points raised by commenters, we are

amending appendix S to allow

interpollutant trading for PM2.

5 in this

final rule. Where a State determines that

it does not have legal authority to issue

such permits, we will act as the

reviewing authority. As of the effective

date of this action, the 2005 PM2.

5 NSR

guidance on use of PM10 emissions as a

surrogate for PM2.5 emissions will

remain in effect only for PSD in the SIPapproved States during the SIP

development period. In the delegated

PSD States and in nonattainment areas,

the new PM2.

5 requirements will apply

immediately on the effective date of thig

final action.

J. Does major NSR apply to PM2.

5

precursors during the SIP development

period?

As discussed previously in section

V.A, we have taken final action on NSR

applicability for PM2.5 precursors.

Specifically, we have designated SO2 as

a national precursor to PM2.

5 in all

areas, NOx as a "presumed-in"

precursor in all areas, VOC as a "presumed-out" precursor in all.areas,

and ammonia as a "presumedrout"

precursor. Thus, States have the option

of bxcluding NOx as a precursor by

demonstrating that NOx emissions are

not a significant contributor to ambient

PM2.

5 concentrations in a particular

area. In addition, States have the option

of identifying VOC and/or ammonia as

precursor(s) by demonstrating that

emissions of VOC and/or ammonia are

a significant contributor in an area, and

thus should be subject to major NSR.

In the proposal, during the SIP

development period, we proposed that

SO2 should be treated as a regulated

PM2.5 precursor as of the effective date

of this final rule since there is no doubt

about its status as such in any area and

proposed to defer NSR applicability for

NOx until a State SIP ubmittal so that

if a State elected to submit information

to rebut the presumption that NOx is a

regulated PM2.

5 precursor, the State

would have an opportunity to do so in

its SIP submittal. We also proposed that

VOCs and ammonia would not be

treated as PM2.

5 precursors. during the

interim period because they are

presumed not to be precursors until

they have been demonstrated to be

through a State's SIP submittal.

A few commenters supported staying

the applicability of NSR to all

precursors during the interim period.

However, two of these supporters

suggested that EPA establish

mechanisms for interpollutant trading

for offsets during the interim period so

that increases in direct PM 2.5 emissions

can be offset with SO 2 or NOx emissions

reductions. Another supporter noted

that their State cannot impose

obligations on NSR applicants until

those obligations are established in State

regulations or statutes. Another

indicated that this delay would allow

States the time to develop experience

and knowledge in establishing local

photochemical models and to

performance test their accuracy.

Two commenters opposed staying -

NSR applicability for any precursors.

They believe that this would make

attainment more difficult. One

commenter suggested that S02 should

be designated as a precursor during the

interim period, and another suggested

the same for S02 and NOx.

Based on the comments, we have been

persuaded that SIP-approved PSD States

will not have the authority to regulate

PM2.

5 precursors before they have

amended thefr SIPs to incorporate these

requirements in attainment areas. Thus,

in order to allow time for these States

to revise their regulations to incorporate

such requirements, this final action does

not require regulation of SO2 or NOx as

precursors to PM2.

5 under PSD until the

SIP development period ends. In

addition, we are allowing SIP-approved

PSD States to continue with the existing

PM10 surrogate policy to meet the PSD

requirements for PM 2.5. However, for

delegated PSD States, SO 2 and NOx are

regulated as precursors from the

effective date of this rule. However,

these States or EPA have the option of

excluding NOx as a precursor by

demonstrating that NOx emissions are

not a significant contributor to ambient

PM2.5 concentrations in a particular

area.

For nonattainment areas, the

transitional program pursuant to

appendix S will apply on the effective

date of this action. Under appendix S,

SO 2 will be regulated as a precursor in

all nonattainment areas for PM2 .

5. -

However, unlike in the proposal, NOx

will not be regulated as a precursor for

PM2.5 because we believe it is

appropriate to give States the

opportunity to determine whether NOx

emissions are a significant contributor

to the ambient PM2.

5 problem, and to

make the appropriate demonstration in

their SIP. Finally, for States determining

that VOC and/or ammonia are PM2.

5

precursors under their SIPs, we will

approve their definition of "significant

emissions rate" for each precursor based

on an appropriate demonstration.

K. Are there any Tribal concerns?

Some Tribal areas may be designated

as nonattainment, in part because of

pollution that is transported from

surrounding State lands. Tribal

representatives have advocated for

additional flexibility to address

nonattainment problems caused by

transported pollution, such as a pool of

available NSR offset set-asides (which

we expect would come from State offset

pools or banks), because they have

limited ability to generate offsets on

their own. Tribal representatives have

raised these and other concerns in

discussions on implementation of the 8-

hour ozohe and PM 2.5 standards, and in

comments on the 8-hour ozone

implementation rule. We requested

comment on whether emissions offset

set-asides, possibly generated by

innovative measures to promote

additional emissions reductions, are an

appropriate method to help level theplaying field for the Tribes and support

economic development in Tribal areas.

We also requested comment on ways in

which States may help -provide the

Tribes access to offsets from non-Tribal

areas. We received no comments on

these issues.

We recently proposed Tribal NSR

rules. See 71 FR 48696, August 21,

2006. They include a NANSR rule,

which refers to appendix S for its

substantive requirements, and a minor

NSR rule. In recognition of the concerns

mentioned above, we have proposed

and sought comments on options for

obtaining offset relief in that proposal.

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We will address these issues in the

context of that rule.

L. What are the requirements for minor

NSR for PM2.5 ?

Pursuant to section 110(a)(2)(C) of the

Act, States must have a minor source

permitting program. This applies to new

arid modified stationary sources that are

not considered major for a criteria

pollutant or a precursor for a criteria

pollutant. Prior to this action, States

were required to include the following

pollutants in their minor NSR program:

* VOC,

" SO 2,

" NOx,

* CO,

" PM1 0 , and

" Lead (Pb).

Based on this action, States must now

amend their minor source programs to

include direct PM 2.5 emissions and

precursor emissions in the same manner

as included for purposes of PM2.5 major

NSR.

M. Rural Transport Areas

In the proposal for the Clean Air Fine

Particle ImplementAtion Rule and this

NSR implementation rule for PM2.

5, we

considered the option of classifying

some nonattainment areas as transport

areas that suffer from overwhelming

transport, and of developing NA NSR

rules specific to such areas. However,

the final implementation rule does not

include the rural transport

classification. Conseqluently, no NA

NSR rules have been developed or

finalized in this rule.

VI. Statutory and Executive Order

Reviews

A. Executive Order 12866: Regulatory,

Planning and Review

Under Executive Order (EO) 12866

(58 FR 51735, October 4, 1993), this

action is a "significant regulatory

action" because it is likely to raise novel

legal or policy issues arising out of legal

mandates, the President's priorities, or

the principles set forth in the Executive

Order. Accordingly, EPA submitted this

action to the Office of Management and

Budget (OMB) for review under EO

12866 and any changes made in

response to OMB recommendations

have been documented in the docket for

this action.

B. Paperwork Reduction Act

The information collection

requirements in this rule have been'

submitted for approval to the OMB

under the Paperwork Reduction Act, 44

U.S.C. 3501 et seq. The information

collection requirements are not

enforceable until OMB approves them.

The Information Collection Request

(ICR) document prepared by EPA has

been assigned OMB Control Number

2060-0003 (EPA ICR No. 1230.21).

To achieve the purposes of the major

NSR program, certain records and

reports are necessary for the Stateor

local agency (or the EPA Administrator

in non-delegated States), for example,

to: (1) Confirm the compliance of status

of stationary sources, identify any

stationary sources -not subject to the

rules, and identify stationary sources

subject to the rules; and (2) ensure that

the stationary source control '

requirements are being achieved. The

information would be used by EPA or

State enforcement personnel to (1)

identify stationary sources subject to the

rules, (2) ensure that appropriate control

technology is being properly applied,

and (3) ensure that the emission control

devices are being properly operated and

maintained on a continuous basis.

This final NSR rule does not create

new information collection

requirements, but rather expands the

coverage of the existing requirements of

the major NSR program. Specifically,

the rule changes finalized in This action

afdd PM2.5 to the list of air pollutants

that must be addressed in the major

NSR program, and the companion

proposal adds certain elements that are

necessary for a complete PM2.5 NSR

program. This change is unlikely to

increase significantly the number of

NSR permits that must be issued, but

may add to the analyses that sources

and Federal, State, and local reviewing

authorities must conduct as part of the

construction permit application and

review process.

We expect the rule changes finalized

in this action to increase the.burden

associated with major NSR permitting

for tracking new emissions of PM2.5

against increments; collecting ambient

air quality monitoring data for existing

PM2.5 concentrations; reviewing the

effects of PM2.5 emissions on soils Wd

vegetation, as well as on air quality

related values in Class I areas;

determining the appropriate best

available control technology or lowest

achievable emission rate; and/or

obtaining offsets. At the same time,

there would be a reduction in burden

directly associated with the revocation

of the annual increment for PM10 , which

is proposed in the propbsed rule.

Over the 3-year period covered by the

ICR, we estimate an average annual

burden increase of about 39,000 hours

(about 8 percent) and $4.3 million

(about 10 percent) for all industry

entities that would be affected by this

final NSR rule. For the same reasons, we

also expect the final rule to increase

burden for the State and local

authorities reviewing permit

applications when fully implemented.

In addition, there would be additional

burden for State and local agencies to

revise their SIPs to incorporate the

proposed changes. We estimate the

cgmbined increase in burden to average

about 16,000 hours and $700,000

annually for all State and local

reviewing autihsrities, which is less than

13 percent.

Burden means the total time, effort, or

financial resources expended by persons

to generate, maintain, retain, or disclose

or provide information to or for a

Federal agency. This includes the time

needed to review instructions; develop,

acquire, install, and utilize technology

and systems for the purposes of

collecting, validating, and verifying

information, processinig and

maintaining information, and disclosing

and providing information; adjust the

existing ways to comply with any

previously applicable instructions and

requirements; train personnel to be able

to respond to a collection of

information; search data sources;

complete and review the collection of

information; and transmit or otherwise

disclose the information.

An agency may not conduct or

sponsor, and a person is not required to

respond to a collection of information

unless it displays a currently valid OMB

control number. The OMB control

numbers for EPA's regulations in 40

CFR are listed in 40 CFR part 9. When

this ICR is approved by OMB, the

Agency will publish a technical

amendment to 40 CFR part 9 in the

Federal Register to display the OMB

control number for the approved

information collection requirements

contained in this final rule.

C. Regulatory Flexibility Act

. The Regulatory Flexibility Act (RFA)

generally requires an agency to prepare

a regulatory flexibility analysis of any

rule subject to notice and comment

rulemaking requirements under the

Administrative Procedure Act or any

other statute unless the Agency certifies

that the rule will not have a significant

economic impact on a substantial

number of small entities. Small entities

include small businesses, small

organizations, and small governmental

jurisdictions.

For purposes of assessing the impacts

of this proposed rule on small entities, "small entity" is defined as: (1) A small

business as defined by the Small

Business Administration's regulations at

13 CFR 121.201; (2) a small

governmental jurisdiction that is a

government or a city, county, town,

I

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school district or special district with a

population of less than 50,000; and (3) a small organization that is any not-forprofit enterprise which is independently

owned and operated and is not

dominant in its field.

After considering the economic

impacts of this final rule on small

entities, I certify that this rule will not

have a significant economic impact on

a substantial number of small entities.

The requirements of this final rule apply

only to new major stationary sources or

major modifications of existing major

stationary sources. This final rule does

not create any new requirements under

the major NSR program, but simply

expands the program to cover an -

additional pollutant, referred to as

PM2.

5 . There is no reason to expect that

the rule will significantly or uniquely

affect small businesses, organizAtions, or

governments (few, if any, of which act

as reviewing authorities pursuant to this

final rule).

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates

Reform Act of 1995 (UMRA), Public

Law 104-4, establishes requirements for

Federal agencies to assess the effects of

their regulatory actions on State, local,

and tribal governments and the private

sector. Under section 202 of the UMRA,

.we generally must prepare a written

statement, including a cost-benefit

analysis, for proppsed and final rules

with "Federal mandates" that may

result in expenditures to State, local,

and tribal governments, in aggregate, or

to the private sector, of $100 million or

more in any 1 year. Before promulgating

an EPA rule for which a written

statement is needed, section 205 of the

UMRA generally requires us to identify

and consider a reasonable number of

regulatory alternatives and adopt the

least costly, most cost-effective, or least

burdensome alternative that achieves

the objectives of the rule. The

provisions of section 205 do not apply

when they are inconsistent with

applicable law. Moreover, section 205

allows us to adopt an alternative other

than the least-costly, most cost-effectivo,

or least-burdensome alternative if the

Administrator publishes with the final

rule an explanation of why that

alternative was not adopted. Before we

establish any regulatory requirements

that may significantly or uniquely affect

'small governments, including tribal

governments, we must have developed

under section 203 of the UMRA a small

government agency plan. The plan must

provide for notifying potentially

affected small governments, enabling

officials of affected small governments

to have meaningful and timely input in

the development of our regulatory

proposals with significant Federal

intergovernmental mandates; and

informing, educating, and advising,

small governments on compliance with

the re ulatory requirements.

We ave determined that this rule

does not contain a Federal mandate that

may result in expenditures of $100

million or more for State, local, and

tribal governments,-in the aggregate, or

the private sector-in any 1 year. The

final rule does not add any new

requirements to the NSR program; it

simply expands the program to cover

PM2.

5 in addition to the several other -

pollutants already defined as regulated

NSR pollutants. (Technically, the rule

also subjects the precursors to PM2.5 to

the NSR program. However, these

precursors (SO 2, NOx" and VOC) are

already subject to the existing NSR

program.) As discussed previously in

section VI.B on the Paperwork

Reduction Act, the expansion of the

NSR program to cover PM2.

5 will only

marginally increase the expenditures of

State, local, and tribal governments and

the private sector on the program. Thus,

this action is not subject to the

requirements of sections 202 and 205 of

the UMRA..

The EPA has determined that this rule

contains no regulatory requirements that

might significantly or uniquely affect

small governments. As noted

previously, thisrule does not create any

new requirements under the major NSR

program, but simply expands the

.program to cover an additional pollutant

(PM2.

5). There is no reason to expect that

the rule will significantly or uniquely

affect small governments, few if any of

Which act as reviewing authorities.

E. Executive Order 13132-Federalism

Executive Order 13132, entitled

"Federalism" (64 FR 43255, August 10,

1999), requires us to develop an

accountable process to ensure "meaningful and timely input by State

and local officials in the development of

regulatory policies that have federalism

implications." "Policies that have

federalism implications" is defined in

the Executive Order to include

regulations that have "substantial direct

effects on the States, on the relationship

between the national government-and

the States, or on the distribution of

powe and responsibilities among the

various levels of government."

This final rule does not have

federalism implications. It will not have

substantial direct effects on the States,.

on the relationship between the national

government and the States, or on the

distribution of power and

responsibilities among the various

levels of government, as specified in

Executive Order 13132. Pursuant to the

terms of Executive Order 13132, it has

been determined that this proposed rule

does not have "federalism implications"

because it does not meet the necessary

criteria. Thus, the requirements of

section 6 of the Executive Order do not

apply to this proposed rule.

In the spirit of Executive Order 13132,

however, and consistent with our policy

to promote communications between us

and State and local governments, we

specifically solicited comment on the

proposed rule from State and local

officials.

F. Executive Order 13175-Consultation

and Coordination With Indian Tribal

Governments

Executive Order 13175, entitled

','Consultation and Coordination with

Indian Tribal Governments" (65 FR

67249, November 9, 2000), requires EPA

to develop an accountable process to

ensure "meaningful and timely input by

Tribal officials in the development of

regulatory policies that have Tribal

implications." This final rule does not

have "Tribal implications" as defined in

Executive Order 13175. This rule

concerns the NSR requirements for State

and tribal implementation plans. The

CAA provides for States to develop

plans to regulate emissions of air

pollutants within their jurisdictions.

The Tribal Air Rule (TAR) under the

CAA gives Tribes the opportunity to

develop and implement CAA programs

such as programs to attain and maintain

the PM 2.5 NAAQS, but it leaves to the

discretion of the Tribe the decision of

whether to develop these programs and

which programs, or appropriate

elements of a program, they will adopt.

Although Executive Order 13175 does

not apply to this rule, EPA did reach out

to Tribal leaders and'environmental

staff in developing this rule. From

2001-2004, the EPA supported a

National Designations,Workgroup to

provide a forum for tribal professionals

to give input to the designations

process. In 2006, EPA supported a

national "Tribal Air call" which

provides an open forum for all Tribes to

voice concerns to EPA about the

NAAQS implementation process,

including the PM2.

5 NAAQS. In these

meetings, EPA briefed call participants

and Tribal environmental professionals

gave input'as the rule was under

development. Furthermore, in December

2005, EPA sent individualized letters to

all federally recognized Tribes about the

proposal to give Tribal leaders the

opportunity for consultation.

This final rule does not have Tribal

implications as defined by Executive

I

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Federal Register/Vol. 73, No. 96/'Friday, May 16, 2008/Rules and Regu~lations

.Order 13175. It does not have a

substantial direct effect on one or more

Indian Tribes, since no Tribe has

implemented a CAA program to attain

the PM2.

5 NAAQS'at this time. The EPA

notes that even if a Tribe were

implementing sich a plan at this time,

while the rule might have Tribal

implications with respect to that Tribe,

it would not impose substantial direct

costs upon. it, nor would it preempt

Tribal law.

Furthermore, this rule does not affect

the relationship or distribution of power

and responsibilities between the Federal

government and Indian Tribes. The

CAA and the TAR establish the

relationship of the Federal government

and Tribes in developing plans to attain

the NAAQS, and this rule does nothing

to modify that relationship. As this rule

does not have Tribal implications,

Executive Order 13175 does not apply.

G. Executive Order 13045-Protection of

Children From Environmental Health

and Safety Risks

Executive Order 13045, entitled

"Protection of Children from

Environmental Health Risks and Safety

Risks" (62 FR 19885, April 23, 1997),

applies to any rule that: (1) Is

determined to be "economically

significant" as defined under Executive

Order 12866; and (2) concerns an

environmental health or safety risk that

we have reason td believe may have a

disproportionate effect on children. If

the regulatory action meets both criteria,

the Agency must evaluate the

environmental health or safety effects of

the planned rule on children, and

explain why the planned regulation is

preferable to other potentially effective

and reasonably feasible alternativesconsidered by the Agency.

This final rule is not subject to the

Executive Order because it is not

economically significant as defined in

Executive Order 12866, and because the

Agency does not have reason to believe

the environmental health or safety risks addressed by this action present a

disproportionate risk to children. This

rule does not impose any new

requirements under the NSR program.

However, in expanding the major NSR

program to address PM2.

5, we believe

that this rule will serve to reduce

environmental health risks to all

citizens, including children, because

one of the basic requirements of the

major NSR program is that new and

modified major stationary sources must

not cause or contribute to air quality in

violation of the NAAQS.

H. Executive Order 13211-Actions

That Significantly Affect Energy Supply,

Distribution, or Use

This rule is not a "significant energy

action" as defined in Executive Order

13211, "Actions Concerning Regulations

That Significantly Affect Energy Supply,

Distribution, -or Use" (66 FR 28355 (May

22, 2001)) because it is not likely to .

have a significant adverse effect on the

supply, distribution, or use of energy.

The final rule does not add any new

requirements to the major NSR program;

it simply expands the program to cover

PM 2.

5 in addition to the several other

pollutants already defined as regulated

NSR pollutants. Although the major

NSR program may apply to energy

supply and distribution companies that

build or significantly modify major

sources of regulated NSR pollutants, we

believe that any increase in

expenditures for obtaining NSR permits

that may result from this rule will be

marginal rather than significant.

L National Technology Transfer and

Advancement Act

As noted in the proposed rule, section

12(d) of the National Technology -

Transfer and Advancement Act of 1995

(NTTAA), Public Law No. 104-113,

12(d) (15 U.S.C. 272 note) directs us to

use voluntary consensus standards

(VCS) in our regulatory and

procurement activities unless to do so

would be inconsistent with applicable

law or otherwise impractical. The VCS

are technical standards (e.g., materials

specifications, test methods, sampling

procedures, and business practices)

developed or adopted by one or more

voluntary consensus bodies. The

NTTAA directs us to provide Congress,

through annual reports to OMB, with

explanations when we do not use

available and applicable VCS.

This final rule does not involve

technical standards. Therefore, we did

not consider the use of any VCS.

J. Executive Order 12898-Federal

Actions to Address Environmental

Justice in Minority Populations and

Low-Income Populations

ExecutiveOrder 12898 (59 FR 7629

(Feb. 16, 1994)) establishes Federal

executive policy on environmental

justice. Its main provision directs

Federal agencies, to the greatest extent

practicable and permitted by law, to

make environmental justice part of their

mission by identifying and addressing,

as appropriate, disproportionately high

and adverse human health -or

environmental effects of its programs,

policies, and activities on minorities

and low-income populations in the

United States.

The EPA has determined that this

final rule will not have

disproportionately high and adverse

human health or environmental effects

on minority or low-income populations

because it will have the effect of

improving air quality. While it does not

impose any new requirements under the

major NSR program, we believe that this

rule, in expanding the NSR program to

address PM2.

5 , will serve to reduce

adverse human health and

environmental effects for all citizens,

including minorities and low-income

populations.

K. Congressional Review Act

The Congressional Review Act, 5

U.S.C. 801 et seq., as added by the Small

Business Regulatory Enforcement

Fairness Act of 1996, generally provides

that before a rule may take effect, the

agency promulgating the rule must

submit a rule report, which includes a

copy of the rule, to each House of the

Congress and to the Comptroller General

of the United States. The EPA will

submit a report containing this rule and

other required information to the U.S.

Senate, the U.S. House of

Representatives, and the Comptroller

General of the United States -prior to

publication of the rule in the Federal

Register. A major rule cannot take effect

until 60 days after it is published in the

Federal Register. This action is not a "major rule" as defined by 5 U.S.C.

804(2). The rules affected by this action

will be effective July 15, 2008.

L. Petitions for Judicial Review

Under section 307(b)(1) of the Act,

petitions for judicial review of this

action must be filed in the United States

Court of Appeals for the District of

Columbia Circuit by July 15, 2008.

Filing a petition for reconsideration by

the Administrator of this final rule does

not affect the finality of this rule for the

purposes of judicial review nor does it

extend the time within which a petition

for judicial review may be filed, and

shall not postpone the effectiveness of

such rule or action. This action may not

be challenged later in proceedings to

enforce its requirements. See Act

section 307(b)(2).

M. Determination Under Section 307(d)

. The PSD portions of this rulemaking,

which implements part C of title I of the

Act, are subject to the proceduralrequirements in section 307(d) of the

Act. See section 307(d)(1)(J). In

addition, pursuant to section

307(d)(1)(V) of the Act, the

Administrator determines that the NA

28346
Federal Register/Vol. 73, No.'96/Friday, May:'16, 2008/Rules and Regulations

NSR portions of this'action should also

be subject to the provisions of section

307(d) to ensure consistency. All of the

procedural requirements of section

307(d), e.g., docketing, hearing, and

comment periods, have been complied

with during the course of this

rulemaking.

VII. Statutory Authority

The statutory authority for this action

is provided by sections 101, 110, 165,

169, 172, 173, 301, and 302 of the Act

as amended (42 U.S.C. 7401, 7410, 7475,

7479, 7502, 7503, 7601, and 7602). This

rulemaking is also subject to section

307(d) of the Act (42 U.S.C. 7407(d)).

List of Subjects

40 CFR Part 51

Environmental protection,

Administrative practices and

procedures, Air pollution control,

Intergovernmental relations.

40 CFR Part 52

Environmental protection,

Administrative practices and

procedures, Air pollution control,

Intergovernmental relations.

Dated: May 8, 2008.

Stephen L. Johnson,

Administrator.

m For the reasons stated in the preamble,

title 40, chapter I of the Code of Federal

Regulations is amended as follows.

PART 51-fAMENDED]

m 1. The authority citation for part 51

continues to read as follows:

Authority: 23 U.S.C. 101; 42 U.S.C. 7401-

7671q.

Subpart I--[Amended]

* 2. Section 51.165 is amended as

follows:

" a. By revising paragraph (a)(1)(x)(A);

" b. By removing the word "or" at the

end of paragraph (a)(1)(xxxvii)(B);

m c. By revising paragraph

(a)(1)(xxxvii)(C);

* d. By adding paragraph

(a)(1)(xxxvii)(D);

m e. By redesignating paragraphs (a)(9) (i)

through (iii) as paragraphs (a)(9)(ii)

through (iv), respectively, and adding -

new paragraph (a)(9)(i);

m f. By removing from newly

redesignated paragraph (a)(9)(iii) the

reference to "paragraph (a)(9)(i)" and

adding in its place "paragraph

(a)(9)(ii)"; and

m g. By adding paragraph (a)(11).

§51.165 Permit requirements.

(a) * * *

(1)* * * . ..

(x)(A) Significant means, in reference

to a net emissions increase or the

potential of a- source to emit any of the

following pollutants, a rate of emissions

that would equal or exceed any of the

following rates:

Pollutant Emission Rate

Carbon monoxide: 100 tons per year

(tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Ozone: 40 tpy of volatile organic

compounds or nitrogen oxides

Lead: 0.6 tpy

PMIo: 15 tpy

PM2.

5: 10 tpy of direct PM2.5 emissions;

40 tpy of sulfur dioxide emissions; 40

tpy of nitrogen oxide emissions unless

demonstrated not to be a PM2.

5

precursor under paragraph

(a)(1)(xxxvii) of this section * * * * *

(xxxvii)* * *

(C) Any pollutant that is identified

under this paragraph (a)(1)(xxxvii)(C) as

a constituent or precursor of a general

pollutant listed under paragraph

(a)(1)(xxxvii)(A) or (B) of this section,

provided that such constituent or

precursor pollutant may only be

regulated under NSR as part of

regulation of the general pollutant.

Precursors identified by the

Administrator for purposes of NSR are

the following:

(1) Volatile organic compounds and

nitrogen oxides are precursors.to ozone

in all ozone nonattainment areas.

(2) Sulfur dioxide is a precursor to

PM2.

5 in all PM2.5 nonattainment areas.

(3) Nitrogen oxides are presumed to

be precursors to PM 2.

5 in all PM2.5

nonattainment areas, unless the State

demonstrktes to the Administrator's

satisfaction or EPA demonstrates that

emissions of nitrogen oxides from

sources in a specific area are not a

significant contributor to that area's

ambient PM 2 .5 concentrations.

(4) Volatile organic compounds and

ammonia are presumed not to be

precursors to PM2.

5 in any PM2.5

nonattainment area, unless the State

demonstrates to the Administrator's

satisfaction or EPA demonstrates that

emissions of volatile organic

compounds or ammonia from sources in

a specific area are a significant

contributor to that area's ambient PM2.5

concentrations; or (D) PM2.

5 emissions and PM10

emissions shall include gaseous

emissions from a source or activity

which condense to form particulate

- matter at ambient temperatures. On or

after January 1, 2011 (or any earlier date

established in the upcoming rulemaking

codifying test methods), such

condensable particulate matter shall be

accounted for in applicability

determinations and in establishing

emissions limitations for PM2.

5 and

PM 10 in nonattainment major NSR

permits. Compliance with emissions

limitations for PM2.

5 and PM 0 issued

prior to this date shall not be based on

condensable particulate matter unless

required by the terms and conditions of

the permit or the applicable

implementation plan. Applicability

determinations made prior to this date

without accounting for condensable

particulate matter shall not be

considered in violation of this section

unless the applicable implementation

plan required condensable particulate

matter to be included. * * * * *

(9)(i) The plan shall require that in

meeting the emissions offset

requirements of paragraph (a)(3) of this

section, the ratio of total actual

emissions reductions to the emissions

increase shall be at least 1:1 unless an

alternative ratio is provided for the

applicable nonattainment area in

paragraphs (a)(9)(ii) through (a)(9)(iv) of

this section.

(11) The plan shall require that in

meeting the emissions offset -

requirements of paragraph (a)(3) of this

section, the emissions offsets obtained

shall be for the same regulated NSR

pollutant unless interprecursor

offsetting is permitted for a particular

pollutant as specified in this paragraph.,

The plan may allow the offset

requirements in paragraph (a)(3) of this

section for direct PM2.

5 emissions or

emissions of precursors of PM2.s to be

satisfied by offsetting reductions in

direct PM2.5 emissions or emissions of

any PM2.

5 precursor identified under

paragraph (a)(1)(xxxvii)(C) of-this

section if such offsets comply with the

interprecursor trading hierarchy and

ratio established in the approved plan

for a particular nonattainment area.

m 3. Section 51.166 is amended as

follows:

m a. By revising paragraphs (b)(23)(i)

and (b)(49)(i);

m b. By removing the word "or" at the

end of paragraph (b)(49)(iii);

m c. By adding and reserving paragraph

(b)(49)(v);

m d. By adding paragraph (b)(49)(vi);

and

m e. By revising paragraphs (i)(5)(ii) and

(i)(5)(iii).

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Federal Register / Vol. 73, No. 96 / Friday, May 16, 2008 / Rules and Reg-Jations

§ 51.166 Pevention of significant

deterioration of air quality. * * * * *

(23)(i) Significant means, in reference

to a net emissions increase or the

potential of a source to emit any of the

following pollutants, a rate of emissions

that would equal or exceed any of the

following rates:

Pollutant and Emissions Rate

Carbon monoxide: 100 tons per year

(tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Particulate matter: 25 tpy of particulate

matter emissions. 15 tpy of PM10

emissions

PM2 .5 : 10 tpy of direct PM2.

5 emissions;

40 tpy of sulfur dioxide emissions; 40

tpy of nitrogen oxide emissions unless

demonstrated not to be a PM 2

. 5

precursor under paragraph (b)(49) of

this section

Ozone: 40 tpy of volatile organic

compounds or nitrogen oxides

Lead: 0.6 tpy

Fluorides: 3 tpy

Sulfuric acid mist: 7 tpy

Hydrogen sulfide (H2S): 10 tpy

Total reduced sulfur (includirig H2S): 10

tpy

Reduced sulfur compounds (including

H2S): 10 tpy

Municipal waste combustor organics

(measured as total tetra-through octachlorinated dibenzo-p-dioxins and

dibenzofurans): 3.2 x 10- - 6

megagrams per year (3.5 x 10-6 tons

per year)

Municipal waste combustormetals

(measured as particulate matter): 14

megagrams per year (15 tons per year)

Municipal waste combustor acid gases

(measured as sulfur dioxide and

hydrogen chloride): 36 megagrams per

year (40 tons per year)

Municipal solid waste landfill

emissions (measured as nonmethane

organic compounds): 45 megagrams

per year (50 tons per year) * * - * * *

(49) * * *

(i) Any pollutant for which a national

ambient air quality standard has been

promulgated and any pollutant

identified under this paragraph (b)(49)(i)

as a constituent or precursor to such

pollutant. Precursors identified by the

Administrator for purposes of NSR are

the following:

(a) Volatile organic compounds and

nitrogen oxides are precursors to ozone

in all attainment and unclassifiable

areas.

(b) Sulfur dioxide is a precursor to

PM2.

5 in all attainment and

unclassifiable areas.

(c) Nitrogen oxjdes are presumed to

be precursors to PM2.

5 in all attainment

and unclassifiable areas, unless the

State demonstrates to the

Administrator's satisfaction or EPA

demonstrates that emissions of nitrogen

oxides from sources in a specific area

are not a significant contributor to that

area's unbient PM 2.

5 concentrations.

(d) Volatile organic compounds are

presumed not to be precursors to PM2.5

in any attainment or unclassifiable area,

unless the State demonstrates to the

Administrator's satisfaction or EPA

demonstrates that emissions of volatile

organic compounds from sources in a

specific area are a significant

contributor to that area's ambient PM2.5

concentrations.

* * * * *

(v) [Reserved.]

(vi) Particulate matter (PM) emissions,

PM2.5 emissions, and PM1 o emissions

shall include gaseous emissions from a

source or activity which condense to

form particulate matter at ambient

temperatures. On or after January 1,

2011 (or any earlier date established in

the upcoming rulemaking codifying test

methods), such condensable particulate

matter shall be accounted for in

applicability determinations and in

establishing emissions limitations for

PM, PM2.

5 and PM10 in PSD permits.

Compliance with emissions limitations

for PM, PM2 .

5 and PMoissued prior to

this date shall not be based on

condensable particular matter unless

required by the terms and conditions of

the permit or the applicable

implementation plan. Applicability

determinations made prior to this date

without accounting for condensable

particular matter shall not be considered

in violation of this section unless the

applicable implementation plan

required condensable particular matter

to be included. * * * * *

(i) * * *

(5) * * *

(ii) The concentrations of the

pollutant in the area that the source or

modification would affect are less than

the concentrations listed in paragraph

(i)(5)(i) .of this section; or

(iii) The pollutant is not listed in

paragraph (i)(5)(i) of this section. * -* * * *

E 4: Appendix S to Part 51 is amended

as follows:

* a. By revising paragraphs II.A.10(i)

and fl.A.31;

* b. By revising paragraph IV.A,

Condition 3;

m c. By redesignating paragraphs IV.G. 1

through IV.G.3 as paragraphs IV.G.2

through IV.G.4, respectively, and adding

new paragraph IV.G.1; m d. By removing from newly

redesignated paragraph IV.G.3 the

reference to "paragrAph IV.G.1" and

adding in its place "paragraph IV.G.2";

and

m e. By adding paragraph IV.G.5.

Appendix S -to Part 51-Emission Offset

Interpretative Ruling

* * * * *

II. * * *

A.* *

10. (i) Significant means, in reference to a net emissions increase or the potential of a source to emit any of the following

pollutants, a rate of emissions that would

equal or exceed any of the following rates:

Pollutant and Emissions Rate

Carbon monoxide: 100 tons per year (tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Ozone: 40 tpy of volatile organic compounds or nitrogen oxides

Lead: 0.6 tpy

Particulate matter: 25 tpy of particulate

matter emissions

PM1o: 15 tpy PM 2.5: 10 tpy of direct PM2.

5 emissions; 40

tpy of sulfur dioxide emissions * * * * *

31. Regulated NSR pollutant, for purposes

of this Ruling, means the following:

(i) Nitrogen oxides or any volatile organic

compounds; (ii) Any pollutant for which a national

ambient air quality standard has been

promulgated;

(iii) Any pollutant that is identified under

this paragraph II.A.31(iii) as a constituent or

precursor of a general pollutant listed under

paragraph ll.A.31(i) or (ii) of this Ruling,

provided that such constituent or precursor

pollutant may only be regulated under NSR as part of regulation of the general pollutant.

Precursors identified by the Administrator

for purposes of NSR are the following:

(a) Volatile organic compounds and

nitrogen oxides are precursors to ozone in all ozone nonattainment areas. (b) Sulfur dioxide is a precursor to PM2 _5

in all PM 2.

5 nonattainment areas; or (iv) Particulate matter (PM) emissions,

PM2 ,

5 emissions and PMie emissions shall

include gaseous emissions from a source or activity which condense to form particulate

matter at ambient temperatures. On or after

January 1, 2011 (or any earlier date

established in the upcoming rulemaking

codifying test methods), such condensable

particulate matter shall be accounted for in

applicability determinations and in

establishing emissions limitations for PM,

PM2 .

5 and PM10 in permits issued under this

ruling. Compliance with emissions

limitations for PM, PM 2.

5 and PMo issued

prior to this date shall not be based on condensable particulate matter unless

required by the terms and conditions of the

permit or the applicable implementation

plan. Applicability determinations made

prior to this date without accounting for

condensable particulate matter shall not be

28348
Federal Register/Vol. 73, No. 96 / Friday, May 16, 2008 / Rules and Regulations

considered in violation of this section unless

the applicable implementation plan required

condensable particulate matter to be

included.

* * * * *t

IV. * * *

A. * * *

Condition 3. Emission reductions (offsets)

from existing sources 5 in the.area of the

proposed source (whether or not under the

same ownership) are required such that there

will be reasonable progress toward

attainment of the applicable NAAQS. Except

as provided in paragraph IV.G.5 of this

Ruling (addressing PM2.

5 and its precursors),

only intrapollutant emissibn offsets will be

acceptable (e.g., hydrocarbon increases may

not be offset against SO 2 reductions).

5 Subject to the provisions of paragraph IV.C of this Ruling. 6 The discussion in this paragraph is a

proposal, but represents EPA's interim policy

until final rulemaking is completed. . * * * *

G. Offset ratios.

1. In meeting the emissions offset

requirements of paragraph IV.A, Condition 3

of this Ruling, the ratio of total actual

emissions reductions to the emissions

increase shall be at least 1:1 unless an

alternative ratio is provided for the

applicable nonattainment aredin paragraphs

IV.G.2 through IV.G.4. * * * * *

5. Interpollutant offsetting. In meeting the

emissions offset requirements of paragraph

IV.A, Condition 3 of this Ruling, the

emissions offsets obtained shall be for the same regulated NSR pollutant unless

interpollutant offsetting is permitted for a particular pollutant as specified in this

paragraph IV.G.5. The offset requirements of

paragraph IV.A, Condition 3 of this Ruling

for direct PM2.5 emissions or emissions of

precursors of PM2.

5 may be satisfied by

offsetting reductions of direct.PM2.5

emissions or emissions of any PM2 .

5

precursor identified under paragraph II.A.31

(iii) of this Ruling if such offsets comply with an interprecursor trading hierarchy and ratio

approved by the Administrator. * * * . * *

PART 52--[AMENDED]

u 5. The authority citation for part 52

continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart A-f[Amended]

* 6. Section 52.21 is amended as

follows:

m a. By revising paragraphs (b)(23)(i)

and (b)(50)(i);

m b. By removing the word "or" at the

end of paragraph (b)(50)(iii);

a c. By adding and reserving paragraph

(b)(50)(v];

n d. By adding paragraphs (b)(50)(vi)

and (i)(1)(xi);

m e. By revising paragraph (i)(5)(ii); and

* f. By adding paragraph (i)(5)(iii).

§52.21 Prevention of significant

deterioration of air quality. * * * * *

(b)*

(23)(i) Significant means, in reference

to a net emissions increase or the

potential of a source to emit any of the

following pollutants, a rate of emissions

that would equal or exceed any of the

following rates:

Pollutant and Emissions Rate

Carbon monoxide: 100 tons per year

(tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Particulate matter: 25 tpy of particulate

matter emissions

PM1o: 15 tpy

PM2.

5: 10 tpy of direct PM2.

5 emissions;

40 tpy of sulfur dioxide emissions; 40

tpy of nitrogen oxide emissions unless

demonstrated not to be a PM2.

5

precursor under paragraph (b)(50) of

this section

Ozone: 40 tpy of volatile organic

compounds or nitrogen oxides

Lead: 0.6 tpy

Fluorides: 3 tpy

Sulfuric acid mist: 7 tpy

Hydrogen sulfide (H2S): 10 tpy

Total reduced sulfur (including H 2 S): 10

tpy

Reduced sulfur compounds (including

H 2S): 10 tpy

Municipal waste combustor organics

(measured as total tetra-through octachlorinated dibenzo-p-dioxins and

dibenzofurans): 3.2 x 10 6

megagrams per year (3.5 x 10 6

tons per year)

Municipal waste combustor metals

.(measured as particulate matter): 14

megagrams per year (15 tons per year)

Municipal waste combustor acid gases

(measured as §ulfur dioxide and

hydrogen chloride): 36 megagrams per

year (40 tons per year)

Municipal solid waste landfills

emissions (measured as nonmethane

organic compounds): 45 megagrams

per year (50 tons per year) * * * * *

(50)* * *

(i) Any pollutant for which a national

ambient air quality standard has been

promulgated and any pollutant

identified under this paragraph (b)(50)(i)

as a constituent or precursor for such

pollutant. Precursors identified by the

Administrator for purposes of NSR are

the following:

(a) Volatile 6rganic compounds and

nitrogen oxides are precursors to ozone

in all attainment and unclassifiable

areas.

(b) Sulfur dioxide is a precursor to

PM2.

5 in all attainment and

unclassifiable areas.

(c) Nitrogen oxides are presumed to

be precursors to PM2.5 in all attainment

and unclassifiable areas, unless the

State demonstrates to the

Administrator's satisfaction or EPA

demonstrates that emissions of nitrogen

oxides from sources in a specific area

are not a significant contributor to that

area's ambient PM2 .5 concentrations.

(d) Volatile organic compounds are

presumed not to be precursors to PM2.

5

in any attainment or unclassifiable area,

unless the State demonstrates to the

Administrator's satisfaction or EPA

demonstrates that emissions of volatile

organic compounds from sources in a

specific area are a significant

contributor to that area's ambient PM2.

5

concentrations.

* * * * *

(v) [Reserved.]

(vi) Particulate matter (PM) emissions,

PM2.

5 emissions and PMI0 emissions

shall include gaseous emissions from a

source or activity which condense to

form particulate matter at ambient

temperatures. On or after January 1,

2011 (or any earlier date established in

the upcoming rulemaking codifying test

methods), such condensable particulate

matter shall be accounted for in

applicability determinations and in

establishing emissions limitations for

PM, PM2.5 and PM10 in PSD permits.

Compliance with emissions limitations

for PM, PM2.5 and PMI0 issued prior to

this date shall not be based on

condensable particular matter unless

required by the terms and conditions of

the permit or the applicable -

implementation plan. Applicability

determinations made prior to this date

without accounting for condensable

particular matter shall not be considered

in violation of this section unless the

applicable implementation plan

required condensable particular matter

to be included. * * * * *

(i] * * *

(1)* ...

(xi) The source or modification was

subject to 40 CFR 52.21, with respect to

PM2.5, as in effect before July 15, 2008,

and the owner or operator submitted an

application for a permit under this

section before that date consistent with

EPA recommendations'to use PM 0 as a

surrogate for PM2.

5, and the

Administrator subsequently determines

that the application as submitted was

complete with respect to the PM2.

5

requirements then in effect, as

interpreted in the EPA memorandum

entitled "Interim Implementation of

New Source Review Requirements for

PM 2.5" (October 23, 1997). Instead, the

requirements of paragraphs (j) through

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Federal Register / Vol. 73, No. 96 / Friday, May 16, -2008 / Rules and Regulations

(r) of this section, as interpreted in the

aforementioned memorandum, that

were in effect before July 15, 2008 shall

-apply to such source or modification. * * * * *

(5) * * *

(ii) The concentrations of the

pollutant in the area that the source or

modification would affect are less than

the concentrations listed in paragraph

(i)(5)(i) of this section; or

(iii) The pollutant is not listed in

paragraph (i)(5)(i) of this section. * * * * *

[FR Doc. E8-10768 Filed 5-15-08; 8:45 am]

BILLING CODE 6560-50-P

DEPARTMENT OF HOMELAND

SECURITY

Federal Emergency Management

Agency

44 CFR Part 67

Final Flood Elevation Determinations

AGENCY: Federal Emergency

Management Agency, DHS.

ACTION: Final rule.

SUMMARY: Base (1% annual chance)

Flood Elevations (BFEs) and modified

BFEs are made final for the

communities listed below. The BFEs

and modified BFEs are the basis for the

floodplain management measures that

each community is required either to

adopt or to show evidence of being

already in effect in order to qualify or

remain qualified for participation in the

National Flood Insurance Program

(NFIP).

DATES: The date of issuance of the Flood

Insurance Rate Map (FIRM) showing

BFEs and modified BFEs for each

community. This date may be obtained

by contacting the office where the maps

are available for inspection as indicated

on the table below.

ADDRESSES: The final BFEs for each

community are available for inspection

at the office of the Chief Executive

Officer of each community. The

respective addresses are listed in the

table below.

FOR FURTHER INFORMATION CONTACT:

William R. Blanton, Jr., Engineering

Management Branch, Mitigation

Directorate, Federal Emergency

Management Agency, 500 C Street, SW.,

Washington, DC 20472, (202) 646-3151.

SUPPLEMENTARY INFORMATION: The

Federal Emergency Management Agency

(FEMA) makes the final determinations

listed below for the modified BFEs for

each.cornmunity listed. These modified

elevations have been published in

newspapers of local circulation and

ninety (90) days have elapsed since that

publication. The Assistant

Administrator of the Mitigation

Directorate has resolved any appeals

resulting from this notification.

This final rule is issued in accordance

with section 110 of the Flood Disaster

Protection Act of 1973, 42 U.S.C. 4104,

and 44 CFR part 67. FEMA has

developed criteria for floodplain

management in floodprone areas in

accordance with 44 CFR part 60.

Interested lessees and owners of real

property are encouraged to review the

proof Flood Insurance Study and FIRM

available at the address cited below for

each community. The BFEs and

modified BFEs are made final'in the

communities listed below. Elevations at

selected locations in each community

are shown.

National Environmental Policy Act.

This final rule is categorically excluded

from the requirements of 44 CFR part

10, Environmental Consideration. An

environmental impact assessment has

not beet prepared.

Regulatory Flexibility Act. As flood

elevation determinations are not within

the scope of the Regulatory Flexibility

Act, 5 U.S.C. 601-612, a regulatory

flexibility analysis is not required.

Regulatory Classification. This final

rule is not a significant regulatory action

under the criteria of section 3(f) of

Executive Order 12866 of September 30,

1993, Regulatory Planning and Review,

58 FR 51735.

Executive Order 13132, Federalism.

This final rule involves no policies that

have federalism implications under

Executive Order 13132.

Executive Order 12988, Civil Justice

Reform. This final rule meets the

applicable standards of Executive Order

12988.

List of Subjects in 44 CFR Part 67

Administrative practice and

procedure, Flood insurance, Reporting

and recordkeeping requirements.

m Accordingly, 44 CFR part 67 is

amended as follows:

PART 67-[AMENDED]

m 1. The authority citation for part 67

-continues to read as follows:

Authority: 42 U.S.C. 4001 et seq.;

Reorganization Plan No. 3 of 1978, 3 CFR,

1978 Comp., p. 329; E.O. 12127, 44 FR 19367,

3 CFR, 1979 Comp., p. 376.

§ 67.11 [Amended]

m 2. The tables published under the

authority of § 67.11 are amended as

follows:

* Elevation in feet

(NGVD) + Elevation in feet Communities

Flooding source(s) Location of referenced elevation (NAVD) affected

# Depth in feet

above ground

Modified

Randolph County, Illinois, and Incorporated Areas

Docket No.: FEMA-B-7740

• Kaskaskia River .....................

Mississippi River ....................

At confluence with Mississippi River ....................................

Randolph/Monroe County boundary (approximately 700

feet upstream Anna Lane extended).

Jackson/Randolph County boundary (approximately Cora

Road extended).

+392

+392

+382

Village of Evansville, Unincorporated Areas of Randolph

County.

City of Chester, Unincorporated Areas of Randolph

County, Village of

Kaskaskia, Village of Prairie Du Rocher, Village of

Rockwood.

28350