[Federal Register: September 14, 2010 (Volume 75, Number 177)]
[Proposed Rules]
[Page 55713-55725]
[DOCID:fr14se10-20]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2006-0952; FRL-9200-9]

Air Quality Implementation Plans; Montana; Attainment Plan for
Libby, MT PM2.5 Nonattainment Area and PM10 State Implementation Plan
Revisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve the State Implementation Plan
(SIP) revision submitted by the State of Montana on March 26, 2008.
Montana submitted this SIP revision to meet Clean Air Act requirements
for attaining the 15.0 micrograms per cubic meter ([mu]g/m3)
annual fine Particulate Matter (PM2.5) national ambient air
quality standard (NAAQS) for the Libby nonattainment area. The plan,
herein called an ``attainment plan,'' includes an attainment
demonstration, an analysis of Reasonably Available Control Technology
and Reasonably Available Control Measures (RACT/RACM), base-year and
projection year emission inventories, and contingency measures. The
requirement for a Reasonable Further Progress (RFP) plan is satisfied
because Montana projects that attainment with the 1997 PM2.5
NAAQS will occur in the Libby nonattainment area by April 2010. In
addition, we are proposing to approve the PM10 SIP revisions
to the Lincoln County Air Pollution Control Program submitted by
Montana on June 26, 2006 for inclusion into Libby's attainment plan.
This submittal contains provisions, including contingency measures, for
controlling both PM10 and PM2.5 emissions from
woodstoves, road dust, and outdoor burning. Finally, EPA is proposing
to find on-road directly emitted PM2.5 and oxides of
nitrogen (NOX) in the Libby, Montana nonattainment area
insignificant for regional transportation conformity purposes. If this
insignificance finding is finalized as proposed, the Libby, Montana
nonattainment area will not have to perform a regional emissions
analysis for either direct PM2.5 or NOX as part
of future conformity determinations for the annual 1997
PM2.5 NAAQS.

DATES: Written comments must be received on or before October 14, 2010.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2006-0952, by one of the following methods:
     http://www.regulations.gov. Follow the on-line
instructions for submitting comments.
     E-mail<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER> (please alert the individual listed in
FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Callie Videtich, Director, Air Program,
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595
Wynkoop St., Denver, Colorado 80202-1129.
     Hand Delivery: Callie Videtich, Director, Air Program,
Environmental Protection Agency (EPA), Region 8, Mail Code 8P-AR, 1595
Wynkoop St., Denver, Colorado 80202-1129. Such deliveries are only
accepted Monday through Friday, 8 a.m. to 4:30 p.m., excluding Federal
holidays. Special arrangements should be made for deliveries of boxed
information.
    Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-
2006-0952. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through http://
www.regulations.gov or e-mail. The http://www.regulations.gov Web site
is an anonymous access system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA, without
going through http://www.regulations.gov, your e-mail address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses. For additional information about EPA's public
docket, visit the EPA Docket Center homepage at http://www.epa.gov/
epahome/dockets.htm. For additional instructions on submitting
comments, go to Section I, ``General Information,'' of the
SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the http://
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at the Air Program,
Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop St.,
Denver, Colorado 80202-1129. EPA requests that, if at all possible, you
contact the individual listed in FOR FURTHER INFORMATION CONTACT to
view the hard copy of the docket. You may view the hard copy of the
docket Monday through Friday, 8 a.m. to 4 p.m., excluding Federal
holidays.

FOR FURTHER INFORMATION CONTACT: Crystal Freeman, Air Program,
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595
Wynkoop Street, Denver, Colorado 80202-1129, Phone:<PHONE_NUMBER>,
Fax:<PHONE_NUMBER><EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Definitions

    For the purpose of this document, we are giving meaning to certain
words or initials as follows:
    (i) The words or initials Act or CAA mean or refer to the Clean Air
Act, unless the context indicates otherwise.
    (ii) The words EPA, we, us or our mean or refer to the United
States Environmental Protection Agency.
    (iii) The initials SIP mean or refer to State Implementation Plan.
    (iv) The initials PM2.5 mean or refer to particulate
matter with an aerodynamic diameter of less than 2.5 micrometers.
    (v) The initials PM10 mean or refer to particulate
matter with an aerodynamic diameter of less than 10 micrometers.
    (vi) The word State or Montana refers to the State of Montana
unless the context indicates otherwise.
    (vii) The initials NAAQS mean or refer to National Ambient Air
Quality Standards.

Table of Contents

I. General Information
II. What Action Is EPA Proposing?
III. What Is the Background for EPA's Proposed Action?
    A. Designation History
    B. Clean Air Fine Particle Implementation Rule
IV. What Is Included in Montana's Submittal?
    A. Background
    B. PM10 SIP Revisions to the Lincoln County Air
Pollution Control Program
    C. Libby and Vicinity PM2.5 Control Plan
V. EPA's Analysis of Montana's Submittal
    A. PM10 SIP Revisions to Lincoln County Air Pollution
Control Program
    B. Attainment Demonstration
    C. Analysis of Montana's Submittal
    1. Pollutants Addressed and Attainment Date
    2. Monitoring Data
    3. Emission Inventory
    4. Modeling
    5. RACT/RACM
    6. Contingency Measures
    7. Transportation Conformity Requirements
VI. Proposed Action
VII. Statutory and Executive Order Reviews

I. General Information

A. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through
http://www.regulations.gov or e-mail. Clearly mark the part or all of
the information that you claim to be CBI. For CBI information in a disk
or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM
as CBI and then identify electronically within the disk or CD ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments,
remember to:
    a. Identify the rulemaking by docket number and other identifying
information (subject heading, Federal Register date and page number).
    b. Follow directions--The agency may ask you to respond to specific
questions or organize comments by referencing a Code of Federal
Regulations (CFR) part or section number.
    c. Explain why you agree or disagree; suggest alternatives and
substitute language for your requested changes.
    d. Describe any assumptions and provide any technical information
and/or data that you used.
    e. If you estimate potential costs or burdens, explain how you
arrived at your estimate in sufficient detail to allow for it to be
reproduced.
    f. Provide specific examples to illustrate your concerns, and
suggest alternatives.
    g. Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
    h. Make sure to submit your comments by the comment period deadline
identified.

II. What action is EPA proposing?

    EPA is proposing to approve two Montana SIP submittals for the
Libby nonattainment area: (1) PM10 SIP revisions to the
Lincoln County Air Pollution Control Program submitted by Montana on
June 26, 2006; and (2) the Libby PM2.5 attainment plan
submitted by Montana on March 26, 2008. EPA has determined that the
PM10 SIP revisions and the PM2.5 attainment plan
meet applicable requirements of the Clean Air Act, including the Clean
Air Fine Particle Implementation Rule (herein referred to as the
implementation rule) issued by EPA on April 25, 2007 (72 FR 20586).
Furthermore, EPA has determined that Montana's PM2.5 SIP
submittal for the Libby area includes an attainment demonstration, an
analysis of RACT/RACM, base-year and projection-year emission
inventories and contingency measures. The attainment plan supports a
determination that the Libby PM2.5 nonattainment area will
attain the 1997 PM2.5 NAAQS by the April 2010 deadline for
attainment. Finally, EPA is proposing to find on-road directly emitted
PM2.5 and NOX in the Libby, Montana nonattainment
area insignificant for regional transportation conformity purposes.
    EPA's analysis and findings are discussed in this proposed
rulemaking. Additional technical support documents are available at
http://www.regulations.gov, Docket No. EPA-R08-OAR-2006-0952.

III. What is the background for EPA's proposed action?

A. Designation History

    On July 18, 1997 (62 FR 38652), EPA established PM2.5
NAAQS, including an annual standard of 15.0 [mu]g/m3 based
on a 3-year average of annual mean PM2.5 concentrations, and
a 24-hour (or daily) standard of 65 [mu]g/m3 based on a 3-
year average of the 98th percentile of 24-hour concentrations. EPA
established the standards based on significant evidence and numerous
health studies demonstrating that serious health effects are associated
with exposures to PM2.5.
    Following promulgation of a new or revised NAAQS, EPA is required
by the CAA to designate areas throughout the United States as attaining
or not attaining the NAAQS; this designation process is described in
section 107(d)(1) of the CAA. In 1999, EPA and state air quality
agencies initiated the monitoring process for the 1997 PM2.5
NAAQS, and, by January 2001, established a complete set of air quality
monitors. On January 5, 2005, EPA published initial air quality
designations for the 1997 PM2.5 NAAQS (70 FR 944), based on
air quality monitoring data for calendar years 2001-2003. On April 14,
2005, EPA published a final supplemental rule amending the agency's
initial designations (70 FR 19844). EPA did not consider modifications
made in this rule to be ``re-designations'' because the changes were
made before April 5, 2005, the effective date of the initial
designations. As a result of the final supplemental rule,
PM2.5 nonattainment designations are in effect for 39 areas,
comprising 208 counties within 20 states (and the District of Columbia)
nationwide, with a combined population of about 88 million people. The
Libby nonattainment area which is the subject of this rulemaking is
included in the list of areas not attaining the 1997 PM2.5
NAAQS.
    On October 17, 2006, EPA strengthened the 24-hour PM2.5
NAAQS to 35 [mu]g/m3 and retained the level of the annual
PM2.5 standard at 15.0 [mu]g/m3 (71 FR 61144). On
November 13, 2009 EPA designated areas as either attainment/
unclassified or nonattainment with respect to the revised 24-hour NAAQS
(74 FR 58688). In the November 2009 designation action, EPA established
a deadline of December 14, 2012 for states to submit attainment plans
for areas designated as nonattainment for the revised 24-hour
PM2.5 NAAQS.
    Of relevance to the proposed rulemaking herein, the notice for the
November 2009 action clarified designations for the 1997
PM2.5 NAAQS by relabeling the existing designation tables to
identify designations for the annual NAAQS, and by providing a separate
table identifying designations for the 1997 24-hour NAAQS (i.e., 65
[mu]lg/m3). In that table, the Libby nonattainment area is
designated as attaining the 1997 24-hour PM2.5 NAAQS.

B. Clean Air Fine Particle Implementation Rule

    On April 25, 2007, EPA issued the Clean Air Fine Particle
Implementation Rule for the 1997 PM2.5 NAAQS (72 FR 20586).
The implementation rule describes the CAA framework and requirements
for developing state PM2.5 attainment plans. An attainment
plan must include a demonstration that a nonattainment area will meet
applicable NAAQS within the timeframe provided in the statute. This
demonstration must include modeling (40 CFR 51.1007) that is performed
in accordance with EPA modeling guidance (EPA-454/B-07-002, April
2007). It must also include supporting technical analyses and
descriptions of all relevant adopted federal, state, and local
regulations and control measures that have been implemented by the
proposed attainment date.
    For the 1997 PM2.5 NAAQS, an attainment plan must show
that a nonattainment area will attain the standard by 2010.
Alternatively, if the area is not expected to meet the NAAQS by 2010, a
state may propose an attainment-date extension for up to five years
based on the severity of the nonattainment problem and on the
availability and feasibility of pollution control measures (CAA section
172(a)(2)).
    For each nonattainment area, the state must demonstrate that it has
adopted all RACT/RACM needed to show that the area will attain the
PM2.5 standards ``as expeditiously as practicable.'' The
implementation rule provided guidance for making these RACM and RACT
determinations (72 FR 20616-21). Any measures that are necessary to
meet these requirements which are not already either federally
promulgated or part of the state's SIP must be submitted in enforceable
form as part of a state's attainment plan.
    The implementation rule also included policies on pollutants that
comprise total PM2.5. Five main types of pollutants
contribute to fine particle concentrations: direct PM2.5,
sulfur dioxide (SO2), nitrogen oxides (NOX),
ammonia, and volatile organic compounds (VOCs). All but direct
PM2.5 is considered to be ``precursors'' to PM2.5
formation. The effect of reducing emissions of each of these five types
of pollutants varies by area, depending on PM2.5
composition, emission levels, and other area-specific factors. For this
reason, the implementation rule established policies regarding what
states should include in their PM2.5 attainment plans for
evaluating these pollutants.
    Under these policies, sources of direct PM2.5 emissions
(including organic particles, elemental carbon and inorganic particles)
and SO2 must be evaluated for emission reduction measures in
all PM2.5 nonattainment areas. Sources of NOX
must be evaluated for emission reduction measures in each area unless
the state and EPA demonstrate that NOX is not a significant
contributor to PM2.5 concentrations in a specific area.
Neither VOC nor ammonia sources are required to be evaluated for
emission reduction measures in an area unless the state or EPA
demonstrates that either of these pollutant types significantly
contributes to PM2.5 concentrations. To reverse any of the
presumptive precursor policies, the implementation rule provided
guidance on the types of analyses that may be included in a technical
demonstration.
    The implementation rule also provided guidance on other elements of
a state's attainment plan, including but not limited to, consideration
of emission inventories, contingency measures, and motor vehicle
emissions budgets used for transportation conformity purposes.

IV. What is included in Montana's submittal?

A. Background

    Libby, Montana, a small rural community, is located in Lincoln
County in the northwestern part of the State. Libby sits in the narrow,
triangular Kootenai valley at an elevation of 2,100 feet. The
nonattainment area is dominated by three major mountain ranges that
limit the air-shed: (1) The Rocky Mountain and Flathead Ranges on the
eastern boundary; (2) the Purcell Range, which roughly bisects the area
from north to south; and (3) the Selkirk and Cabinet Ranges on the
western boundary. The vast majority of the area surrounding Libby is
National Forest managed by the U.S. Forest Service. Based on the 2000
census and a growth rate through 2005 of 3.71%, Libby's population is
estimated at 2,674.
    The highest PM2.5 concentrations in Libby generally
occur during the winter months of November through February. The winter
concentrations are related to stagnant weather conditions dominated by
light winds and strong temperature inversions. These meteorological
conditions can trap emissions within the valley for many days or weeks.
    Air quality data recorded during 2001-2003 at the PM2.5
monitor at the Libby Courthouse Annex showed violations of the annual
PM2.5 standard. Libby was designated nonattainment for
PM2.5 under section 107(d)(3) of the CAA, on April 5, 2005
(40 CFR part 81). The air quality planning requirements for
PM2.5 nonattainment areas are set out in Title I subpart 1
of the Act.\1\
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    \1\ Subpart 1 applies to nonattainment areas generally.
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    Historically, Libby was designated nonattainment for
PM10 by operation of law on November 15, 1990 (56 FR 56694,
56794, November 6, 1991), under CAA section 107(d)(4)(B) and was
classified as ``Moderate.'' The PM10 attainment plan was
approved by EPA on August 30, 1994 (59 FR 44627). Montana has submitted
revisions to the Lincoln County Air Pollution Control Program (herein
referred to as the Program) and the Libby and Vicinity PM2.5
Control Plan (herein referred to as the Libby attainment plan) for the
purpose of demonstrating attainment of the annual PM2.5
NAAQS. After public notice, public hearings regarding these two
submittals were held on February 27, 2006 for the Lincoln County Air
Pollution Control Program and on March 25, 2008 for the Libby and
Vicinity PM2.5 Control Plan. The Montana Board of
Environmental Review approved the revised Lincoln County Air Pollution
Control Program on March 23, 2006 and the Libby attainment plan on
March 25, 2008. Montana has met the requirements of Section 110(a)(2)
for reasonable notice and public hearings.

B. PM10 SIP Revisions to the Lincoln County Air Pollution Control
Program

    Montana submitted revisions to the PM10 SIP for the
Lincoln County Air Pollution Control Program for the Libby
nonattainment area to improve and strengthen the PM10
attainment plan. The revisions include several provisions to regulate
solid fuel burning devices and require owners and operators to obtain
operating permits. Operating permits may only be issued for EPA-
certified woodstoves or for pellet stoves. Furthermore, only specified
materials can be burned in these devices, and visible emissions of
greater than 20% opacity from them are prohibited. Additionally, these
provisions allow for air pollution alerts if PM10 or
PM2.5 concentrations averaged over a 4-hour period exceed a
level 20 percent below any federal or state particulate matter
standard. Provisions are also included for penalties for non-compliance
and contingency measures.
    Additionally, revisions were made for open and outdoor burning
regarding prohibited materials, major open burning and management
burning, minor open burning or residential open

burning, and special burning. These revisions generally included
significant limits on the time periods for open burning activities as
compared to the existing PM10 SIP. Further restrictions also
include prohibitions on burning from November 1 to March 31, which is
the winter-time period when exceedances of PM2.5 typically
occur. Lincoln County's Program prohibits burning the same materials as
the State but is more restrictive because the burning of trade waste,
Christmas tree waste, leaves, grass clippings and stumps is prohibited
within the Air Pollution Control District \2\ (herein referred to as
the District). The June 26, 2006 submittal also included a stringency
analysis for the Program showing that the revisions are more stringent
than comparable State law.
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    \2\ The boundaries of the District are identical to those for
the nonattainment area.
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C. Libby and Vicinity PM2.5 Control Plan

    The Libby attainment plan provides a demonstration that the annual
PM2.5 NAAQS will be met by April 2010 through the
implementation of the Lincoln County Program described in section B
above. The Libby attainment plan includes an emissions inventory (EI),
a woodstove air pollution control calculation, and a technical analysis
showing that the emissions of PM2.5 will be reduced
sufficiently to meet the NAAQS. The key components of the Libby
attainment plan are described as follows:
    1. Ambient air quality monitoring in the Libby area began in 1999
and is conducted using Federal Reference Method (FRM) PM2.5
samplers at the Courthouse Annex site in downtown Libby. Based on
monitoring data from the years 2001 to 2003, the 3-year annual design
value was 15.9 [micro]g/m\3\, which is a violation of the annual
PM2.5 NAAQS. In February 2002, speciation monitoring was
conducted to determine possible PM2.5 emission sources. The
results identified organic carbon as the main component of wintertime
PM2.5 emissions. Further ambient monitoring was conducted
from November 2003 to February 2004 to determine the geographic
distribution of PM2.5 concentrations. After additional
monitoring from various locations beyond Libby city limits and
meteorological data from Libby Courthouse Annex site, it was determined
that the Libby Courthouse Annex site represented the worst-case ambient
PM2.5 levels in the area.
    2. A chemical mass balance study (CMB) was conducted during the
winter of 2003-2004 by the University of Montana, Center for
Environmental Health Sciences (UM-CEHS). The goal of the CMB study was
to identify those emission sources in the Libby area that contributed
to elevated PM2.5 concentrations. The CMB model runs
indicated that emissions from residential wood combustion were the
major source of the fine particles on the PM2.5 filters,
averaging 82% during the CMB study period (i.e., winter months). Other
contributing PM2.5 sources identified by the CMB model were
automobile exhaust (7%), ammonium nitrate (5%), diesel exhaust (4%),
and sulfate (2%).\3\
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    \3\ Ward, T.J., Rinehart, L.R., Lange, T. The 2003/2004 Libby,
Montana PM2.5 Source Apportionment Research Study.
Aerosol Science and Technology. Vol. 40:166-177. 2006.
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    3. Carbon 14 (\14\C) analysis, as a part of the CMB study completed
by UM-CEHS, was conducted by the University of Arizona's Accelerator
Mass Spectrometry Laboratory Facility to provide further evidence that
wood combustion was the major source of PM2.5 emissions in
Libby.\4\
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    \4\ Ibid.
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    4. The Libby base year PM2.5 EI included a
quantification of actual PM2.5 emissions and apportioned the
emissions on a seasonal and annual basis for point and area sources.
The State used calendar year 2005 as the base year for the development
of an EI for the Libby area. The EI was used to support a proportional
rollback model for the emission control plan. The State developed
information for 2005 that allowed for the calculation of residential
wood combustion and commercial fuel use.
    5. The Libby PM10 SIP as revised also serves as the
control plan for emissions of PM2.5. Controls exist for
reducing emissions from re-entrained road dust through aggressive
street sweeping and flushing, and traction sand durability
requirements. Emissions of organic carbon are controlled through
residential woodstove regulations and outdoor burning restrictions.
    6. A significant part of the PM2.5 control strategies
has been the completion of a woodstove changeout program. Approximately
1,130 uncertified woodstoves were replaced with EPA-certified
woodstoves or pellet fuel burning devices. After the changeout,
PM2.5 emissions have been reduced from approximately 138.78
tons/year to 57.21 tons/year, a decrease of 59%.
    PM2.5 control strategies are primarily focused on
residential wood combustion. The control strategies also include: air
pollution alerts may be declared during the winter months; solid fuel
burning devices must have an operating permit; only EPA-certified
woodstoves and pellet fuel burning devices can obtain permits; and only
permitted pellet fuel devices can operate during air pollution alerts.
Other control strategies for PM2.5 have included an expanded
area for the prescribed burning control program and the continuing
federal tailpipe standards.
    7. Analysis for RACT/RACM was conducted for the Libby area. EPA's
RACT/RACM guidance covers three general source categories: stationary,
mobile and area (79 FR 20586). The Libby PM2.5 CMB study did
not identify any emissions from local stationary sources, only a minor
amount from mobile sources, and a significant amount from an area
source category--residential wood combustion. EPA's area source RACM
guidance covers four source categories: (1) Reduced solvent usage or
solvent substitution; (2) controls on charbroiling or other commercial
cooking operations; (3) controls on woodstoves and fireplaces; and (4)
new or improved regulations on open burning (79 FR 20586 and 20621).
The Libby attainment plan concluded that wood combustion control
strategies and more stringent rules on open burning constituted RACM
for area sources. The analysis further noted that the other two
categories of area sources, commercial users of solvent and commercial
cooking, were infrequent in the Libby area. The analysis also
considered mobile sources, but determined that in light of their small
contribution to PM2.5 nonattainment, existing federal
tailpipe standards and natural turnover rates of the local vehicle
fleet made additional measures for mobile sources unnecessary.
    8. The Lincoln County Air Pollution Control Program is legally
enforceable by Lincoln County, and by the State should Lincoln County
fail to administer the program. The Libby attainment plan also provides
for contingency measures if the NAAQS are exceeded after
implementation. There is one contingency measure for wood burning for
space heating purposes if it is determined that wood burning emissions
contribute to an exceedance of the PM2.5 NAAQS, then only
biomass pellet fuel burners may operate within the District. Other
contingency measures are included for re-entrained dust and industrial
facilities. There is also a review process to consider permanent
adoption of a contingency measure.

V. EPA's Analysis of Montana's Submittal

A. PM10 SIP Revisions to Lincoln County Air Pollution Control Program

    EPA's summary of the PM10 SIP revisions is addressed in
detail under section IV.B. These revisions were made for two purposes:
(1) To address PM2.5 attainment plan requirements; and (2)
to improve and strengthen requirements for continued attainment of
PM10. The revisions are a significant improvement to a plan
that was approved by EPA 16 years ago. The Libby area has not had an
exceedance of the PM10 NAAQS since 1993. Furthermore,
clarifications were made to the language to better explain to the
public the requirements of the air quality program. The revisions
removed exemptions and replaced them with requirements for obtaining
permits for wood burning appliances. These revisions also added
enforcement provisions where previously none had existed.
    Section 110(l) of the Clean Air Act states that a SIP revision
cannot be approved if the revision would interfere with any applicable
requirement concerning attainment and reasonable further progress
toward attainment of the NAAQS or any other applicable requirement of
the Act. The Libby area is currently meeting the NAAQS for all criteria
pollutants and has not had any violations of the PM10
standard for over a decade. Furthermore, the revisions do not relax the
stringency of any SIP provision; in fact, the revisions generally
strengthen the SIP. As a result, the PM10 SIP revisions do
not interfere with attainment of the NAAQS or any other applicable
requirement of the Act. Therefore, section 110(l) requirements are
satisfied.

B. Attainment Demonstration

    In accordance with section 172(c) of the CAA and the implementation
rule, the attainment plan submitted by Montana for the Libby area
included: (1) Emission inventories for the plan's base year (2005) and
projection year (2009); and (2) an attainment demonstration consisting
of: (a) Technical analyses that locate, identify, and quantify sources
of emissions contributing to violations of the annual PM2.5
NAAQS; (b) analyses of future-year emission reductions and air quality
improvements expected to result from national and local programs, and
from new measures to meet RACT/RACM requirements; (c) adopted emission
reduction measures; and (d) contingency measures.

C. Analysis of Montana's Submittals

1. Pollutants Addressed and Attainment Date
    In accordance with policies described in the implementation rule,
Montana's PM2.5 attainment plan evaluates emissions of
direct PM2.5, SO2 and NOX in the Libby
area. Montana provided documentation of expeditious attainment of the
annual PM2.5 NAAQS in the Libby area by April 2010. Areas
that demonstrate attainment by 2010 are considered to have satisfied
the requirement to show reasonable further progress toward attainment
and need not submit a separate RFP plan. For similar reasons such areas
are also not subject to a requirement for a mid-course review.
    Montana's evaluation of emissions is based on the work conducted by
UM-CEHS for the CMB model runs indicating that emissions from
residential wood combustion were the major source (82%) of the fine
particles on the PM2.5 filters. Other PM2.5
sources identified by the CMB model were automobile exhaust (7%),
ammonium nitrate (5%), diesel exhaust (4%), and sulfate (2%). In
addition, a Carbon 14 analysis confirmed that wood combustion is the
major source of PM2.5 emissions in the Libby area and that
emissions of both SO2 and NOX are very minor
compared to PM2.5 emissions from residential wood
combustion. As described in the emissions inventory, the sources of
SO2 are from home heating oil and sources of NOX
are from on-road and off-road mobile sources (see further discussion in
section V.C.7. on NOX emissions from mobile sources).
2. Monitoring Data
    As shown in the table below, the annual weighted average for 2009
shows that the Libby area has met the April 2010 deadline for the 1997
PM2.5 NAAQS. The trend in annual average concentrations is
downward and coincides with the implementation of the woodstove
changeout program. This is based on quality-controlled and quality-
assured monitoring data from 2005-2009 that is available in the EPA Air
Quality System (AQS).

                               Table V.2-1
------------------------------------------------------------------------
                                              Annual weighted average
                   Year                             ([mu]g/m\3\)
------------------------------------------------------------------------
2005.....................................                          15.8
2006.....................................                          15.2
2007.....................................                          13.0
2008.....................................                          12.9
2009.....................................                          10.7
------------------------------------------------------------------------

3. Emission Inventory
    CAA section 172(c)(3) states that for nonattainment areas, the
State shall prepare a statewide emission inventory no later than three
years after designation. The baseline emission inventory for calendar
year 2005 or another suitable year shall be used for attainment
planning (40 CFR 51.1008(b)). EPA promulgated the Air Emissions
Reporting Rule (AERR) (40 CFR part 51, subpart A) in order to
consolidate the various reporting requirements that already exist,
including those requirements outlined in the PM2.5
implementation rule. The AERR requires states to report state-wide
emissions every three years. Montana prepared a statewide emission
inventory for 2005. This inventory included annual totals of emissions
of criteria pollutants and their precursors. The State used data from
this statewide inventory to create an emission inventory specific to
the Libby area.
    Monitoring data for 2005 showed an exceedance of the
PM2.5 annual standard. The year 2005 is a suitable year for
attainment planning because an emission inventory for this year is
representative of ambient emission levels that led to the exceedance of
the annual standard. The 2005 emission inventory showed that
residential wood burning comprised 82% of the direct PM2.5
emissions during the winter. The next largest direct source, road dust,
was 11%, followed by locomotive emissions at 3.4%. The remaining
criteria pollutant emissions were very minor, including the precursors
of PM2.5 (i.e., NOX and SO2).
Background values of PM2.5 were accounted for by the State
using monitored data collected at remote stations far away from
emissions sources in the Libby area. EPA notes that the State used a
conservative emission inventory approach for projecting future growth
for the 2010 attainment year which involved increasing the vehicle
emissions by 2.1% (the population growth rate) from the 2005 base year
inventory, and not taking any credit for potential emission reductions
that may have been available from fleet turnover and the Federal
tailpipe standards for vehicles. Condensable particulate matter was not
considered in the emission inventory because of a lack of sources in
the Libby area.
4. Modeling
    CAA Section 172(c) requires states with nonattainment areas to
submit an attainment demonstration. A PM2.5 attainment
demonstration consists of (1) analyses which estimate whether

selected emissions reductions will result in ambient concentrations
that meet the NAAQS and (2) a set of control measures which will result
in the required emissions reductions.
    Montana's analysis of future-year emissions reductions and air
quality improvements was based on a proportional rollback model for
showing attainment of the standard and a roll forward model
demonstrating attainment in the future. The proportional models were
applied in conjunction with the findings from chemical mass balance and
Carbon 14 studies conducted by the University of Montana.
    In the particular case of Libby, a proportional model is more
appropriate than dispersion models. The great majority of periods with
elevated PM2.5 concentrations in Libby occur during
wintertime stagnation conditions. Furthermore, dispersion in Libby is
constrained by steep terrain. The most suitable approach for stagnation
conditions should be determined on a case-by-case basis, (see sections
7.2.8 and <IP_ADDRESS>(b) of the Guideline on Air Quality Models, 40 CFR
part 51, appendix W), and an alternative model should be selected by
the EPA Regional Office when a preferred model is less appropriate (see
section 3.2.2 of the Guideline).
    The proportional model used the emission inventory for 2005 when
there was an exceedance of the standard. The decrease in
PM2.5 emissions for the Libby area resulting from the
woodstove changeout program was calculated based on the amount of wood
burned by the EPA-certified woodstoves and then compared to the amount
of emissions resulting from burning the same amount of wood from the
uncertified woodstoves that were still in use. The decrease in
emissions would be an indication of the effectiveness of the control
strategy. Montana estimated that PM2.5 emissions would be
reduced by 81.57 tons as a result of the new EPA-certified woodstoves
installed in Libby households.
    The State projected future annual average PM2.5
concentrations for Libby at 9.5 [mu]g/m\3\. This projection was based
on the installation of the new stoves and a 100 percent compliance with
the wood burning restrictions for Libby. EPA's guidance is based on
emission sources complying with state and local restrictions on
emission sources (Emissions Inventory Guidance for Implementation of
Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations, appendix B, EPA-454/R-05-001,
August 2005.) The guidance defines rule effectiveness (RE) as a method
to account for the reality that not all emission sources are in
compliance 100% of the time.
    The guidance provides a listing of the factors that are most likely
to affect RE. EPA used a conservative 70% RE instead of a 100 percent
compliance to determine if Libby would still reach attainment of the
PM2.5 standard. EPA estimated that using the more
conservative compliance percentage for wood burning restrictions, the
future value for Libby would still be below the PM2.5
standard of 15 [mu]g/m\3\. As stated above in Table V.2.-1 the Libby
area 2009 annual average is currently 10.7 [mu]g/m\3\.
5. RACT/RACM
    Determination of RACT/RACM is a three-step process: (1) Identifying
potential measures that are reasonable; (2) modeling to identify the
attainment date that is as expeditious as practicable; and (3)
selecting RACT/RACM. Identification of potential measures should
ordinarily be supported by an inventory of emissions of directly
emitted PM2.5 and of precursors from the relevant sources
and source categories; the technologically feasible control measures
for each source or source category; and, for each measure, the control
efficiency, possible emission reductions by pollutant, estimated cost
per ton, and the date by which the measure was or could be implemented;
and other relevant information.
    For the first step, identification of potential measures that are
reasonable, Montana supported its RACT/RACM analysis with the emissions
inventory and the CMB study. The RACT/RACM analysis first noted that
there are no major stationary sources of PM2.5 in the Libby
area. It also noted that minor stationary sources are currently
regulated under Montana's minor source program, which requires permits
and a Best Available Control Technology (BACT) review. As discussed in
the implementation rule, if state or federal rules already regulate a
given sector, it is reasonable for a state to look to unregulated
sectors for RACT/RACM measures. Furthermore, the implementation rule
permits the state to use reason in the extent of its effort to identify
potential control measures. For example, the rigor of the analysis may
depend on the relative contribution of a particular pollutant to the
PM2.5 nonattainment problem (72 FR 20613). As shown by the
CMB study, stationary sources are a very minor contributor to
PM2.5 nonattainment in Libby. Similarly, the RACT/RACM
analysis reasoned that mobile sources are currently regulated, make
only a minor contribution to the nonattainment problem, and the overall
emissions will continue to be reduced through fleet turnover. Thus, the
first step focused on measures for area sources.
    The analysis further noted that two types of area sources
(commercial users of solvents and commercial charbroilers or other
commercial cooking operations) were infrequent in the Libby area. The
analysis also discussed re-entrained road dust, which the CMB study did
not identify as a contributor to PM2.5 nonattainment, and
noted that there were existing SIP provisions to control road dust. As
to home heating oil, a source of SO2, the CMB study found
only a 2% contribution to PM2.5 nonattainment for all
sulfates combined. Thus, the RACM analyses focused on the remaining
area sources of wood burning devices and open burning and identified
several control measures to be included in the attainment plan.
    For the second step, as discussed in more detail in section V.C.4,
Montana modeled attainment by 2010 based on adoption of these
reasonable control measures. Finally, for the third step, based on the
analysis, Montana selected and adopted RACM for wood burning devices
and open burning. For wood burning devices, the State developed and
implemented a woodstove changeout control strategy. The woodstove
changeout permanently removed 1,130 old, uncertified woodstoves and
replaced them with EPA-certified woodstoves or pellet stoves.
Additionally, the State adopted measures that require permits for solid
fuel burning devices (including woodstoves) and restrict installation
and operation of these devices to three categories: pellet stoves,
devices with a catalytic emissions control system, and devices with a
non-catalytic emissions control system. For the latter two, emission
limits are imposed.
    RACM measures were also included for major open burning, management
burning, residential burning, and special burning. The PM2.5
attainment plan includes BACT and permits for an expanded area, which
is the entire Air Pollution Control District, for all of these
different types of burning activities. Additionally, these burning
activities were restricted to shorter time periods.
    In summary, the State evaluated, by source category, sources of
direct PM2.5, SO2 and NOX for RACT/
RACM control measures. The State's evaluation of sources of
SO2 and NOX resulted in their decision that no
additional controls are necessary to attain the

NAAQS based on the absence of major sources or area sources that can be
cost effectively or reasonably controlled. The State therefore adopted
RACM for direct PM2.5. In accordance with Section 172(c) of
the CAA, Montana has adopted all RACT/RACM needed to attain the
standards as expeditiously as practicable. EPA has reviewed Montana's
RACT/RACM analysis and has determined that the state reasonably
identified potential control measures, modeled the attainment date that
is as expeditious as practicable and reasonably selected RACT/RACM for
the Libby area.
6. Contingency Measures
    In conformance with Section 172(c)(9) of the CAA, the
implementation rule requires that PM2.5 attainment area
plans include contingency measures. These measures must be fully
adopted or otherwise ready for quick implementation, should contain
trigger mechanisms and an implementation schedule, should be measures
not included in the SIP control strategy, and should provide the
equivalent of one year of RFP. Once triggered, a contingency measure
should take effect without further action by the State or EPA.
    The Libby SIP contains contingency measures for residential wood
burning, re-entrained dust, and industrial facilities. If it is
determined that residential wood burning contributes to an exceedance
of the PM2.5 NAAQS, then only biomass pellet fuel burners
may operate within the District. If re-entrained dust contributes to
noncompliance, then the existing regulations (which currently only
apply in a limited area) are made applicable to the entire Air
Pollution Control District. Finally, if an industrial facility
contributes to noncompliance, the Montana Department of Environmental
Quality (MTDEQ) will initiate contingency measures to reduce emissions.
Once a contingency measure is initiated, it must remain active until
the Libby SIP demonstration is revised and resubmitted to EPA for
approval.
    The contingency measures for residential wood burning and re-
entrained dust meet the requirements of the implementation rule. The
contingency measure for major point sources would require further
action by MTDEQ to determine whether additional controls are necessary.
However, the contingency measures for residential wood burning and re-
entrained dust are sufficient to meet the requirements of the CAA,
including equivalence to one year of RFP.
7. Transportation Conformity Requirements
    Transportation conformity is required under CAA section 176(c) (42
U.S.C. 7506(c)) to ensure that transportation plans, transportation
improvement programs (TIPs) and federally supported highway and transit
projects are consistent with (``conform to'') the state air quality
implementation plan. Transportation conformity applies to areas that
are designated nonattainment, and to those areas redesignated to
attainment after 1990 with a CAA section 175A maintenance plan
(``maintenance areas''), for transportation-related criteria
pollutants: carbon monoxide (CO), NOX and particulate matter
(PM2.5 and PM10).
    EPA's transportation conformity rule (40 CFR parts 51 and 93)
establishes the criteria and procedures for determining whether
transportation activities conform to the SIP. One requirement of the
rule is that transportation plans, TIPs, and projects must satisfy a
regional emissions analysis for the relevant pollutants and precursors
(40 CFR 93.118, 119). However, section 93.109(m) of this rule states
that an area is not required to satisfy a regional emissions analysis
for a pollutant or precursor if the SIP demonstrates that motor vehicle
emissions of that pollutant or precursor are an insignificant
contributor to the area's air quality problem. In today's notice, EPA
is proposing to find that motor vehicle emissions of PM2.5
and NOX are insignificant contributors to Libby's
PM2.5 nonattainment problem. If this proposal is finalized,
PM2.5 and NOX motor vehicle emissions budgets
(MVEB) would not be established and a regional emissions analysis would
not be required for either PM2.5 or NOX in any
future conformity determination in Libby. Please note, however, that
this proposed action would not apply to PM2.5 hot-spot
analyses for individual projects, if such an analysis is required in
the future for transportation conformity purposes.
    There are specific transportation conformity provisions that EPA
proposes to determine as applicable to the Libby PM2.5
nonattainment area. As provided in more detail in 40 CFR 93.109(m),
these specific conformity provisions are addressed when EPA finds that
emissions from motor vehicles in the Libby PM2.5
nonattainment area are an insignificant contributor to the areas'
nonattainment problem for a relevant NAAQS and/or precursor.
    To consider making such an insignificant finding, EPA evaluated the
provisions of 40 CFR 93.109(m) against the relevant information
contained in the SIP attainment plan, the SIP revision's associated
technical support document (TSD), and additional information as
developed by EPA. We evaluated the following factors in determining
whether on-road direct PM2.5 and NOX emissions
are insignificant contributors to the area's PM2.5 air
quality problem; (1) the percentage of motor vehicle emissions in the
context of the total SIP inventory; (2) the current state of air
quality as determined by monitoring data for that NAAQS; (3) the
absence of SIP motor vehicle control measures; and (4) historical
trends and future projections of the growth of motor vehicle emissions.
Our evaluation and conclusions are as follows:
a. The Percentage of PM2.5 Motor Vehicle Emissions in the
Context of the Total SIP Inventory
    This factor, with regard to PM2.5 emissions, is
addressed in two areas of the SIP revision documentation. Table
<IP_ADDRESS>B (``PM2.5 Annual Demonstration of Compliance'')
of the Libby attainment plan provides relevant information with regard
to 2003-2004 CMB percentages by source category, percent reduction in
emissions due to control strategies, estimated growth in emissions over
the 2005 to 2010 time period, and 2010 compliance year contributions.
The dominant CMB source was residential woodstoves at 82% with motor
vehicle tailpipe emissions at 7% of total PM2.5 mass and
diesel exhaust at 4% of the total PM2.5 mass.
    The contribution of motor vehicle PM2.5 emissions is
also documented in Table 5.1A (``Seasonal PM 2.5 Emissions in Libby by
Source Category'') of the SIP's TSD. Table 5.1A presents estimated
emissions based on metric tons and percentage of the inventory for
2005, by season; we have provided these motor vehicle tailpipe
PM2.5 emissions, as percent of total PM2.5
emissions, in Table V.7-1 below. We note that in Table 5.1A of the
SIP's TSD, the inventory is dominated by woodstove emissions in all
four seasons.

                Table V.7--1 Motor Vehicle PM2.5 Emissions Percentage of Total Inventory for 2005
                                        (All figures are in metric tons)
----------------------------------------------------------------------------------------------------------------
                                                                                Motor vehicle
                          Season                              Motor vehicle    Total inventory   emissions % of
                                                             PM2.5 emissions   PM2.5 emissions        total
----------------------------------------------------------------------------------------------------------------
Winter....................................................              0.48             80.63              0.59
Spring....................................................              0.55             46.43              1.18
Summer....................................................              0.66             13.66              4.83
Fall......................................................              0.51             97.67              0.52
    Total Year............................................               2.2            238.38              0.92
----------------------------------------------------------------------------------------------------------------

    As shown in Table V.7.-1 above, motor vehicle tailpipe
PM2.5 emissions represent an annual average of only 0.92% of
the total PM2.5 inventory. That is, motor vehicle emissions
are less than one percent of the inventory over the course of a year.
During the summer, motor vehicle emissions make up close to five
percent of the inventory, but motor vehicle emissions are only slightly
higher during the summer than during other seasons. The motor vehicle
emissions percentage is much greater during the summer compared with
other seasons primarily because total PM2.5 emissions are
significantly reduced during the summer compared to other seasons;
summer is the season with the fewest emissions from woodstoves. The
information provided in the State's submittal supports a conclusion
that regional PM2.5 on-road mobile source emissions are a
minimal percentage in the context of the total PM2.5
emissions inventory. Therefore, this factor supports the proposed
finding that on-road PM2.5 emissions are insignificant for
the Libby PM2.5 nonattainment area.
b. The Current State of Air Quality as Determined by Monitoring Data
for the PM2.5 NAAQS
    This factor is addressed as shown in the table below. From the
State's SIP revision and section V.B.2 above, from 2007 to 2009 the
Libby area continues to demonstrate attainment of the 1997 annual
PM2.5 NAAQS. Furthermore, the trend in annual average
concentrations is downward and coincides with the implementation of the
woodstove changeout program. This data is based on quality-controlled
and quality-assured monitoring data from 2005-2009 that are available
in the EPA AQS. This factor supports the proposed finding that on-road
PM2.5 emissions are insignificant for the Libby
PM2.5 nonattainment area.

                              Table V.2.-1
------------------------------------------------------------------------
                                           PM2.5 annual weighted average
                   Year                              ([mu]g/m3)
------------------------------------------------------------------------
2005.....................................                          15.8
2006.....................................                          15.2
2007.....................................                          13.0
2008.....................................                          12.9
2009.....................................                          10.7
------------------------------------------------------------------------

c. The Absence of SIP Motor Vehicle Control Measures for
PM2.5
    The Libby PM2.5 attainment plan relies on a 59%
reduction in residential woodstove emissions to reach attainment of the
annual PM2.5 NAAQS and took no credit for any emission
reductions in the motor vehicle tailpipe and diesel exhaust categories
(e.g. Federal tailpipe emission standards and fleet turnover). The
State further described these assumptions in sections <IP_ADDRESS>
(``Federal Tailpipe Standards Control Program'') and <IP_ADDRESS>
(``PM2.5 2010 Demonstration of Compliance'') of the Libby
attainment plan. EPA also notes there is no State or local mandated
motor vehicle emission control requirements (e.g., inspection and
maintenance program, fuels, or transportation control measures) for the
Libby PM2.5 nonattainment area. Therefore, this factor
supports the proposed finding that on-road PM2.5 emissions
are insignificant for the Libby PM2.5 nonattainment area.
d. Historical Trends and Future Projections of the Growth of Motor
Vehicle PM2.5 Emissions
    Libby's annual PM2.5 2001-2003 design value was 15.9
[mu]g/m\3\. In November 2003 through February 2004 air quality data was
collected in Libby to support CMB modeling. This CMB modeling showed
that residential wood smoke was the primary source of PM2.5
in Libby. Table <IP_ADDRESS>B in the Libby attainment plan shows that,
when the results of the CMB modeling are applied to the air quality
data from 2001-2003, residential wood smoke contributed 13.0 [mu]g/m\3\
(82%) of the 2001-2003 annual PM2.5 design value, motor
vehicle tailpipe emissions contributed 1.1 [mu]g/m\3\ (7%), and diesel
exhaust emissions contributed 0.7 [mu]g/m\3\ [mu]g/m\3\ (4%). Based on
the results of this modeling Montana based its attainment strategy for
the area on a woodstove change-out program.
    The SIP assumes that the woodstove change-out program will reduce
those emissions by 59% in 2010. The SIP also assumes that motor vehicle
tailpipe emissions and diesel exhaust emissions would grow by 2.1%
between 2005 and 2010, which is equal to the expected population growth
rate during that period. The SIP does not account for any reductions in
motor vehicle emissions or diesel exhaust that would occur due to fleet
turnover to new lower emission motor vehicles, on-road diesel vehicles
or off-road equipment. Table <IP_ADDRESS>B in the Libby attainment plan
shows that in 2010 the predicted annual average PM2.5
concentration would be 8.37 [mu]g/m\3\. The table also shows that
residential wood smoke is expected to contribute 5.44 [mu]g/m\3\ (65%)
in 2010, motor vehicle tailpipe emissions would contribute 1.12 [mu]g/
m\3\ (13%), and diesel exhaust emissions would contribute 0.71 [mu]g/
m\3\ (8%). As can be seen, on a percentage basis the contribution of
motor vehicle emissions and diesel exhaust increases; however, overall
PM2.5 concentrations are expected to decrease by 53% to 8.37
[mu]g/m\3\, the contribution of wood smoke emissions is expected to
decrease by 59%, and the total contribution of emissions from motor
vehicles and diesel exhaust to PM2.5 mass in 2010 is
expected to increase by only 0.03 [mu]g/m\3\ between 2005 and 2010.
This increase in mass is due to the assumptions that emissions from
these sources increase at the same rate as population growth and that
no emissions reductions from fleet turnover are included in the
calculations. Both of these are conservative assumptions.
    EPA notes that the contribution of motor vehicle emissions of 13%
to PM2.5 mass in 2010 represents the projected chemical mass
balance of PM2.5 and not an emission inventory projection.
The

SIP includes a base year PM2.5 inventory (Table 5.1A) for
2005. That inventory shows that motor vehicle emissions of
PM2.5 are 2.20 tpy and that total PM2.5 emissions
in the base year are 238.39 tpy. Therefore, the motor vehicle emissions
in the base year are slightly less than 1% of the total direct
PM2.5 emissions. On the surface this may seem to be in
conflict with the results of the CMB modeling, which shows that motor
vehicle exhaust contributed about 7% of the PM2.5 mass in
the base year. However, it should be noted that the chemical mass
balance data and the PM2.5 data collected at the Libby
Courthouse Annex represents only one receptor within the City of Libby,
and only for the period of late 2003 through early 2004. While this
location is believed to be representative of Libby's air quality,
numerous factors influence the local particulate matter concentrations
and air quality. Local scale meteorology (wind speed, wind direction,
temperature, relative humidity, barometric pressure, and solar
radiation at a minimum), traffic patterns, and precipitation are a few
examples of these factors which vary throughout the city. Accepting
that variable conditions exist throughout Libby, as well as the
inherent uncertainty associated with ambient air monitoring, the
difference that exists between PM2.5 monitoring data at one
receptor and a city-wide emission inventory appears to be plausible.
    We also note that the actual location of the monitor may have
exposed it to additional influence from motor vehicle emissions. We
have not performed an in-depth analysis, but we do note that the
monitor is located directly adjacent to U.S. Highway 2, the main north/
south highway through Libby. Although motor vehicle PM2.5
emissions are shown to be minimal in the State's emissions inventory
(ref. Table 5.1A: ``Seasonal PM2.5 Emissions in Libby by
Source Category'' and Table V.7.-1 above), motor vehicle emissions may
have shown a greater than anticipated contribution on the chemical mass
balance analysis due to the monitor's close proximity to Highway 2.
    Overall, this factor supports the proposed finding that on-road
PM2.5 emissions are insignificant for the Libby
PM2.5 nonattainment area. In summary, all four factors
support the proposed finding. After weighing these four factors
described in 40 CFR 93.109(m) and evaluated above, EPA proposes to find
that on-road PM2.5 emissions are insignificant for the Libby
PM2.5 nonattainment area. We turn to applying the four
factors to on-road NOX emissions.
e. The Percentage of NOX Motor Vehicle Emissions in the
Context of the Total SIP Inventory
    The Libby attainment plan focuses on directly emitted
PM2.5 and controls of PM2.5 emissions from
woodstoves and does not address any motor vehicle NOX
emissions other than to indicate in Table <IP_ADDRESS>B
``PM2.5 Annual Demonstration of Compliance'' that the CMB
data show that ammonium nitrate was only 5% of the mass found on the
filters. EPA, therefore, drew upon other relevant, available data to
evaluate whether NOX motor vehicle emissions in the Libby
PM2.5 nonattainment area are significant and require that a
NOX motor vehicle emissions budget be established for
transportation conformity purposes or whether on-road NOX
emissions could be found insignificant based on the criteria in 40 CFR
93.109(m).
    EPA reviewed relevant information from EPA's National Emissions
Inventory (NEI) data for 2005 that were used for the 2009 final
designations for the 24-hour 2006 PM2.5 NAAQS (74 FR 58688,
November 13, 2009).\5\ However, since the NEI data were for Lincoln
County as a whole, we needed to assess how much of the Lincoln County
on-road NOX inventory could be apportioned to the Libby
PM2.5 nonattainment area. Our methodology was to calculate
how many vehicle miles traveled (VMT) the Libby PM2.5
nonattainment area contributes to Lincoln County's total VMT and to
assign that same proportion of the total Lincoln County on-road
NOX emissions to the Libby PM2.5 nonattainment
area, as explained further below. We then needed to determine what
percentage this was of total NOX from the Libby
PM2.5 nonattainment area.
---------------------------------------------------------------------------

    \5\ The 2005 NEI data from EPA's PM2.5 24-hour 2006
NAAQS final designations information are available at: http://
www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.
---------------------------------------------------------------------------

    Specific emissions data for Lincoln County, MT, which includes the
Libby PM2.5 nonattainment area, are presented in Table V.7.-
2 below and are from EPA's PM2.5 24-hour 2006 NAAQS final
designations information.

                                                Table V.7.-2--(All emission figures are in tons per year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                County                      Major category        VOC      NOX      SO2      NH3     PM2.5      OC       EC      SO4      NO3     PMFine
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lincoln..............................  Fires..................     6106      310      277      425     2199     1286      219       20       10      664
Lincoln..............................  Non-Road...............      338     2403      169        1       76       16       55        0        0        4
Lincoln..............................  On-Road................      366      545       15       23       11        3        6        0        0        2
Lincoln..............................  Other-Stationary.......      871      138       74       57      453      108       16        5        1      323
    Total............................  .......................     7681     3395      535      506     2738     1412      296       25       11      994
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The ``On-Road'' or motor vehicle, 2005 NEI emissions were
calculated by EPA for Lincoln County based on a county annual total of
VMT of 231,246,800. This VMT figure, which represents data for the
entire county, is also referenced in our 2006 PM2.5 24-hour
NAAQS final designations information.\6\
---------------------------------------------------------------------------

    \6\ See http://www.epa.gov/ttn/naaqs/pm/pm25_2006_
techinfo.html; Factor 4.B ``Vehicle Miles Traveled''.
---------------------------------------------------------------------------

    Based on the 2005 NEI data referenced above in Table V.7.-2,
Lincoln County's total annual VMT of 231,246,800 results in
approximately 545 tpy of on-road NOX. To calculate the
estimated on-road NOX emissions for the Libby
PM2.5 nonattainment area, we first needed to determine what
percentage of Lincoln County's total VMT is attributed to the Libby
PM2.5 nonattainment area. We then applied that VMT
percentage to the total Lincoln County on-road NOX emissions
to get the estimated on-road NOX emissions for the Libby
PM2.5 nonattainment area. The total VMT for the Libby
PM2.5 nonattainment area, 54,877,360, came from the
MTDEQ.\7\ This is 23.73% of Lincoln County's total VMT (i.e.,
54,877,360 VMT from Libby divided by 231,246,800 VMT from Lincoln
County as a whole). It is reasonable to assume that the Libby
PM2.5 nonattainment area contributes this same percentage of
on-road NOX emissions to the total Lincoln County on-road
NOX emissions. Therefore, we applied this 23.73% to the
Lincoln County total of 545 tpy of

on-road motor vehicle NOX emissions, which results in
approximately 129.33 tpy of on-road NOX emissions for the
Libby PM2.5 nonattainment area. In lieu of other specific
data, EPA considers this approach a reasonable estimate of the on-road
NOX emissions for the Libby PM2.5 nonattainment
area.
---------------------------------------------------------------------------

    \7\ VMT data was communicated in a February 26, 2010, email from
Jim Carlin of MTDEQ to Tim Russ of EPA Region 8.
---------------------------------------------------------------------------

    Once we had a figure for the number of tons of on-road
NOX emissions from Libby, the next step in our analysis was
to determine what percentage of the total anthropogenic NOX
this represents. Again, since the NEI data available were for Lincoln
County as a whole, we needed to assess how much of the Lincoln County
total anthropogenic NOX could be apportioned to the Libby
PM2.5 nonattainment area. To do so, we needed to establish
what NOX emissions were from anthropogenic sources in the
Libby PM2.5 nonattainment area other than from on-road motor
vehicle tailpipes. To develop these particular emissions figures, we
assumed that the percentage of Lincoln County's anthropogenic
NOX coming from Libby would be the same as the percentage of
Lincoln County's anthropogenic PM2.5 emissions coming from
Libby, as described below.
    First, we determined the anthropogenic NOX emissions for
Lincoln County from the ``Non-Road'' and ``Other Stationary'' source
categories. We used the data from Table V.7.-2 above and eliminated the
``Fires'' \8\ and ``On-Road'' emissions categories from the Lincoln
County 2005 NEI data (see Table V.7.-3 below):
---------------------------------------------------------------------------

    \8\ The ``Fires'' category of the 2005 NEI relates to wildfires,
prescribed burns and such. This correlates to the ``Large Prescribed
Burning'' and ``General Burning'' categories in the State's Table
5.1A.

                                                   Table V.7.-3--(All emissions are in tons per year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                County                      Major category        VOC      NOX      SO2      NH3     PM2.5      OC       EC      SO4      NO3    PM Fine
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lincoln..............................  Non-Road...............      338     2403      169        1       76       16       55        0        0        4
Lincoln..............................  Other-Stationary.......      871      138       74       57      453      108       16        5        1      323
    Total............................  .......................     1209     2541      243       58      529      124       71        5        1      327
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The total anthropogenic NOX in Lincoln County from
sources other than on-road is 2541 tpy.
    Next, we summed-up the PM2.5 emissions from the Libby
PM2.5 nonattainment area from the State's SIP emission
inventory Table 5.1A, but did not include emissions from fires (i.e.,
PM2.5 emissions from ``Large Prescribed Burning'' and
``General Burning'' were not included from the State's Table 5.1A); see
Table V.7.-4 below.

                                Table V.7.-4--Libby Anthropogenic PM2.5 Emissions
(As adapted from Table 5.1A ``Seasonal PM2.5 Emissions in Libby by Source Category'' of the Libby Attainment SIP
                                               Emission Inventory)
----------------------------------------------------------------------------------------------------------------
                           Sources                               Winter       Spring       Summer        Fall
----------------------------------------------------------------------------------------------------------------
Woodstoves Residential/Com..................................        66.65        20.74         5.08        58.76
Paved Roads Fugitive Dust...................................         8.92         2.57         3.23         9.61
Large Prescribed Burning....................................        - - -        - - -        - - -        - - -
General Burning.............................................        - - -        - - -        - - -        - - -
Locomotives.................................................         2.72         2.72         2.72         2.72
Unpaved Roads Fugitive Dust.................................         1.22         1.34         1.53          1.2
Propane Heating Residential/Com.............................         0.13         0.04         0.01         0.11
Oil Heating Residential/Com.................................         0.48         0.15         0.04         0.42
Aircraft....................................................          0.0         0.03         0.03          0.0
Road & Building Construction Dust...........................         0.02         0.36         0.36         0.36
Motor Vehicle Tailpipe......................................         0.48         0.55         0.66         0.51
    Total (Metric Tons).....................................        80.62        28.50        13.66        73.69
    Total Short Tons (2000 lbs. per ton)....................        88.88        31.42        15.06       81.24
----------------------------------------------------------------------------------------------------------------
Total Annual Anthropogenic Short Tons of PM2.5 Emissions = 216.60 tons.

    Based on the data in Table V.7.-4 above, the total annual
anthropogenic short tons of PM2.5 emissions (without
including emissions from the ``Motor Vehicle Tailpipe'' category) from
``Non-Road'' and ``Other Stationary'' sources in the Libby
PM2.5 nonattainment area are estimated as 214.17 tons per
year.
    The Libby PM2.5 nonattainment area's annual emissions of
PM2.5 from ``Non-Road'' and ``Other Stationary''
anthropogenic sources is 214.17 tpy, whereas these sources emit 529 tpy
for Lincoln County as a whole (see Table V.7.-3 above). Therefore,
Libby's share of Lincoln County's PM2.5 emissions from
``Non-Road'' and ``Other Stationary'' anthropogenic sources is
approximately 40.48%.
    We then added Lincoln County NOX emissions from the
``Non-Road'' and ``Other Stationary'' sources categories, 2541 tpy (see
Table V.7-3 above), and attributed 40.48% of those emissions to the
Libby PM2.5 nonattainment area's NOX ``Non-Road''
and ``Other Stationary'' sources categories, which results in 1028.6
tpy. To summarize, EPA estimated the Libby PM2.5
nonattainment area's on-road NOX motor vehicle emissions as
129.33 tpy, and the non-road and other stationary sources'
NOX emissions as 1028.6 tpy. Therefore, the total estimated
annual anthropogenic NOX emissions from all of these source
categories are estimated to be 1157.93 tpy for the Libby
PM2.5 nonattainment area. The approximate contribution of
annual on-road NOX motor vehicle emissions (129.33 tpy) to
the total estimated NOX annual anthropogenic emissions from
all sources (1157.93 tpy) in the Libby PM2.5 nonattainment
area is 11.17% of the total inventory.
    EPA indicated in its July 1, 2004 Transportation Conformity final
rule (69 FR 40004) that mobile source emissions

of approximately 10% may be considered insignificant, but did not make
10% a specific threshold. While the 11.7% figure calculated for on-road
NOX in the Libby PM2.5 nonattainment area is
slightly greater than this, in this same rulemaking EPA explained:

    ``This example also illustrates the reason EPA believes it is
important to have flexibility in implementing this provision.
Although the commenter specifically mentions 10% as the threshold
for finding motor vehicle emissions insignificant, EPA clarifies
that this figure is a general guideline only. Depending on the
circumstances, we may find that motor vehicle emissions that make up
less than 10% of an area's total inventory are still significant.
Conversely, we may also find that motor vehicle emissions in excess
of 10% are still insignificant, under certain circumstances relating
to the overall composition of the air quality situation. In general,
the percentage of motor vehicle emissions in the area's total
inventory is an important criterion for determining whether motor
vehicles are a significant or insignificant contributor to an area's
air quality problem, yet there are other criteria that EPA will
examine when making this finding, as described in the regulatory
text for Sec.  93.109(k).'' (69 FR 40062) \9\

    \9\ EPA redesignated the insignificance provision of the
transportation conformity rule from 40 CFR 93.109(k) to 40 CFR
93.109(m) in its March 24, 2010 ``PM Amendments'' final rule (75 FR
14260).
---------------------------------------------------------------------------

    As stated in the 2004 preamble, 10 percent is a guideline only. As
described below, EPA considered other factors that lead EPA to propose
that motor vehicle emissions of NOX are an insignificant
regional contributor to the PM2.5 nonattainment problem.
f. The Current State of Air Quality as Determined by Monitoring Data
for PM2.5 NAAQS
    This factor is addressed with the ambient PM2.5 air
quality data presented in section V.7.B above which demonstrate the
Libby PM2.5 nonattainment area is attaining the
PM2.5 annual NAAQS. Additional data, relevant to
NOX or in this case nitrates derived from NOX
emissions,\10\ were provided by EPA with the 2009 final designations
for the 24-hour 2006 PM2.5 NAAQS. This information, as
provided in Table V.7-5 below, is from EPA's PM2.5 24-hour
2006 NAAQS final designations and is located at: http://www.epa.gov/
ttn/naaqs/pm/pm25_2006_techinfo.html.
---------------------------------------------------------------------------

    \10\ Nitrogen oxides react in the atmosphere to form nitrates.
For our purposes, the impact of NOX emissions is measured
as the amount of nitrates found at the PM2.5 monitor.

                                                    Table V.7-5--PM2.5 Composition Data for Libby, MT
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Sulfate    Nitrate     Carbon    Crustal     Total
             Area/County/State                   PM2.5 composition data       ([mu]mg/   ([mu]mg/   ([mu]mg/   ([mu]mg/   ([mu]mg/   Nitrate     Carbon
                                                                               m\3\)      m\3\)      m\3\)      m\3\)      m\3\)     percent    percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Libby/Lincoln/MT...........................  Total Concentration (Cold)....        1.4        0.8       41.9        0.3       44.4          2         94
                                             Regional Concentration (Cold).        0.9        0.4        2.4        0.2        3.9         10         62
                                             Urban Concentration (Cold)....        0.5        0.4       39.5        0.1       40.5          1         98
                                             Total Concentration (Warm)....        1.2        0.0        6.7        0.8        8.7          0         77
                                             Regional Concentration (Warm).        1.0        0.0        2.5        1.1        4.6          0         54
                                             Urban Concentration (Warm)....        0.2        0.0        4.2        0.0        4.4          0         95
                                             Total Concentration (Annual           1.0        0.1       12.8        0.4       14.3          1         90
                                              Average).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    As can be seen in Table V.7-5 above, nitrates (as derived from
NOX) are a very small component of the PM2.5
composition found in the Libby PM2.5 nonattainment area.
Therefore, NOX as derived from motor vehicle tailpipe
emissions also is a very small component. This factor thus supports the
proposed finding that on-road NOX emissions are
insignificant for the Libby PM2.5 nonattainment area.
g. The Absence of SIP Motor Vehicle Control Measures for NOX
    As discussed in section V.7.C above, the Libby PM2.5
attainment plan took no credit for any emission reductions in the motor
vehicle tailpipe and diesel exhaust categories (e.g. Federal tailpipe
emission standards and fleet turnover). The State further described
these assumptions in sections <IP_ADDRESS> (``Federal Tailpipe Standards
Control Program'') and <IP_ADDRESS> (``PM2.5 2010
Demonstration of Compliance'') of the Libby attainment plan. EPA also
notes there is no State or local mandated motor vehicle emission
control requirements (e.g., inspection and maintenance program, fuels,
or transportation control measures) for the Libby PM2.5
nonattainment area. Therefore this factor supports the proposed finding
that on-road NOX emissions are insignificant for the Libby
PM2.5 nonattainment area.
h. Historical Trends and Future Projections of the Growth of
NOX Motor Vehicle Emissions
    As noted in our discussion in section V.7.D above, the Libby
attainment plan uses a 59% reduction in residential woodstove emissions
to reach attainment of the annual PM2.5 NAAQS and took no
credit for any emission reductions in the motor vehicle tailpipe and
diesel exhaust categories. The State further described these
assumptions in sections <IP_ADDRESS> (``Federal Tailpipe Standards Control
Program'') and <IP_ADDRESS> (``PM2.5 2010 Demonstration of
Compliance'') of the Libby attainment plan. EPA notes that the State
used a conservative emission inventory approach for projecting the 2010
attainment year future growth which involved merely increasing the
vehicle emissions by 2.1% (the population growth rate) from the 2005
base year inventory, and not taking any credit for potential emission
reductions that may have been available from fleet turnover and the
Federal tailpipe standards for vehicles. In addition, as we noted
above, there are no State or local mandated motor vehicle emission
control requirements (e.g., inspection and maintenance program) for the
Libby PM2.5 nonattainment area.
    This factor supports the proposed finding that on-road
NOX emissions are insignificant for the Libby
PM2.5 nonattainment area. After weighing these four factors
described in 40 CFR 93.109(m) and evaluated above, EPA proposes to find
that on-road NOx emissions are insignificant for the Libby
PM2.5 nonattainment area.
i. Conclusion
    In view of our evaluation presented above per 40 CFR 93.109(m), EPA
is proposing to find that direct PM2.5 and NOX
motor vehicle emissions are an insignificant contributor to the air
quality issues associated with the PM2.5

annual NAAQS in the Libby PM2.5 nonattainment area; thus,
motor vehicle emission budgets for on-road direct PM2.5 and
NOX would not be established by this rulemaking. Based on
our evaluation of the four factors described in 93.109(m), EPA proposes
to conclude that it would be unreasonable to expect that the Libby
PM2.5 nonattainment area would experience enough motor
vehicle emissions growth such that a PM2.5 annual NAAQS
violation would occur.

VI. Proposed Action

    The EPA has reviewed Montana's SIP revision for attaining the
15[mu]g/m\3\ annual PM2.5 NAAQS for the Libby
PM2.5 nonattainment area. EPA is proposing to approve the
State of Montana's revisions to the Lincoln County Air Pollution
Control Program to be included in Montana's SIP, submitted on June 26,
2006, and the Libby PM2.5 attainment plan, submitted on
March 26, 2008. Action was not taken earlier on the June 26, 2006,
submittal at the request of the State of Montana to delay action until
the submittal of the Libby PM2.5 attainment plan at a later
date. EPA has determined that the SIP meets applicable requirements of
the CAA, as described in the Clean Air Fine Particle Implementation
Rule. Specifically, EPA has determined that Montana's SIP includes an
attainment demonstration and adopted state regulations and programs
needed to support the determination that the Libby PM2.5
nonattainment area will continue attaining the annual PM2.5
NAAQS. Finally, EPA is proposing to find on-road, directly emitted
PM2.5 and NOX in the Libby, Montana nonattainment
area insignificant for regional transportation conformity purposes.

VII. Statutory and Executive Order Reviews

A. Executive Order 12866, Regulatory Planning and Review

    Under Executive Order 12866, (58 FR 51735 (October 4, 1993)) the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to the Office of Management and Budget (OMB)
review and the requirements of the Executive Order. The Order defines
``significant regulatory action'' as one that is likely to result in a
rule that may: (1) Have an annual effect on the economy of $100 million
or more or adversely affect in a material way the economy, a sector of
the economy, productivity, competition, jobs, the environment, public
health or safety, or state, local, or tribal governments or
communities; (2) create a serious inconsistency or otherwise interfere
with an action taken or planned by another agency; (3) materially alter
the budgetary impact of entitlements, grants, user fees, or loan
programs or the rights and obligations of recipients thereof; or (4)
raise novel legal or policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the Executive
Order.'' The OMB has exempted this regulatory action from Executive
Order 12866 review.

B. Paperwork Reduction Act

    This action does not impose an information collection burden under
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
This action proposes to approve the SIP revisions submitted by the
State of Montana.

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.
    This proposed rule will not have a significant impact on a
substantial number of small entities because SIP approvals and
disapprovals under section 110 and subchapter I, part D of the Clean
Air Act do not create any new requirements, but simply approve or
disapprove requirements that the state is already imposing. Therefore
because the Federal SIP approval does not create any new requirements,
I certify that this action will not have a significant economic impact
on a substantial number of small entities. Moreover, due to the nature
of the Federal-state relationship under the Clean Air Act, preparation
of flexibility analysis would constitute Federal inquiry into the
economic reasonableness of state action. The Clean Air Act forbids EPA
to base its actions concerning SIPs on such grounds. Union Electric
Co., v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 42 U.S.C. 7410(a)(2).

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, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to state, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA 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 EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it 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 EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
    EPA has 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 one year. This Federal action proposes to partially
approve and partially disapprove pre-existing requirements under state
or local law, and to disapprove a redesignation request, and imposes no
new requirements. Accordingly, no additional costs to state, local, or
tribal governments, or to the private sector, result from this action.
Thus, today's rule is not subject to the requirements of sections 202
and 205 of the UMRA.

E. Executive Order 13132, Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA 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 power and
responsibilities among the various levels of government.''
    This proposed 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. This rule merely proposes to
partially approve and partially disapprove state rules implementing a
Federal standard, and to disapprove a redesignation request, and does
not alter the relationship or the distribution of power and
responsibilities established in the Clean Air Act. Thus, Executive
Order 13132 does not apply to this rule.

F. Executive Order 13175, 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 proposed rule does not have tribal
implications, as specified in Executive Order 13175. It will not have
substantial direct effects on tribal governments, on the relationship
between the Federal government and Indian tribes, or on the
distribution of power and responsibilities between the Federal
government and Indian tribes. This action does not involve or impose
any requirements that affect Indian Tribes. Thus, Executive Order 13175
does not apply to this rule.

G. Executive Order 13045, Protection of Children From Environmental
Health Risks and Safety Risks

    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 EPA has reason to 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 alternatives
considered by the Agency.
    EPA interprets Executive Order 13045 as applying only to those
regulatory actions that are based on health or safety risks, such that
the analysis required under section 5-501 of the Order has the
potential to influence the regulation. This proposed rule is not
subject to Executive Order 13045 because it proposes to approve a state
rule implementing a Federal program.

H. Executive Order 13211, Actions That Significantly Affect Energy
Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, Actions
Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use (66 FR 28355, May 22, 2001) because it is not a
significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C.
272 note) directs EPA to use voluntary consensus standards in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (e.g., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by voluntary consensus standards bodies. The NTTAA directs EPA
to provide Congress, through OMB, explanations when the Agency decides
not to use available and applicable voluntary consensus standards.
    This proposed rulemaking does not involve technical standards.
Therefore, EPA is not considering the use of any voluntary consensus
standards.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental
relations, Oxides of nitrogen, Particulate matter, Reporting and
recordkeeping requirements.

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

    Dated: September 2, 2010.
Stephen S. Tuber,
Acting Regional Administrator, Region 8.
[FR Doc. 2010-22848 Filed 9-13-10; 8:45 am]
BILLING CODE 6560-50-P