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Approval and Promulgation of Air Quality Implementation Plans; State of Montana; Missoula Carbon Monoxide Redesignation to Attainment, Designation of Areas for Air Quality Planning Purposes, and Approval of Related Revisions

 
[Federal Register: April 25, 2007 (Volume 72, Number 79)]
[Proposed Rules]
[Page 20480-20488]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25ap07-18]

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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[EPA-R08-OAR-2006-0163; FRL-8305-2]

Approval and Promulgation of Air Quality Implementation Plans;
State of Montana; Missoula Carbon Monoxide Redesignation to Attainment,
Designation of Areas for Air Quality Planning Purposes, and Approval of
Related Revisions

AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve State Implementation Plan (SIP)
revisions submitted by the State of Montana. On May 27, 2005, the
Governor of Montana submitted a request to redesignate the Missoula
``moderate'' carbon monoxide (CO) nonattainment area to attainment for
the CO National Ambient Air Quality Standard (NAAQS). The Governor also
submitted a CO maintenance plan which includes transportation
conformity motor vehicle emission budgets (MVEB) for 2000, 2010, and
2020. In addition, EPA is proposing to approve CO periodic emission
inventories for 1993 and 1996 for the Missoula nonattainment area that
the State had previously submitted. This action is being taken under
section 110 of the Clean Air Act.

DATES: Comments must be received on or before May 25, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2006-0163, by one of the following methods:
--http://www.regulations.gov. Follow the on-line instructions for
submitting comments.
--E-mail: videtich.callie@epa.gov and fiedler.kerri@epa.gov.
--Fax: (303) 312-6064 (please alert the individual listed in the FOR
FURTHER INFORMATION CONTACT if you are faxing comments).
--Mail: Callie A. Videtich, Director, Air and Radiation Program,
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595
Wynkoop Street, Denver, Colorado 80202-1129.

[[Page 20481]]

--Hand Delivery: Callie A. Videtich, Director, Air and Radiation
Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-
AR, 1595 Wynkoop Street, 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-
2006-0163. 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 and Radiation
Program, Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop
Street, Denver, Colorado 80202-1129. EPA requests that if at all
possible, you contact the individual listed in the FOR FURTHER
INFORMATION CONTACT section 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: Kerri Fiedler, Environmental
Protection Agency, Region 8, 1595 Wynkoop Street, Denver, Colorado
80202-1129, phone (303) 312-6493, and e-mail at: fiedler.kerri@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
II. What is the purpose of this action?
III. What is the State's process to submit these materials to EPA?
IV. EPA's Evaluation of the Missoula Redesignation Request and
Maintenance Plan
V. EPA's Evaluation of the Transportation Conformity Requirements
VI. Consideration of Section 110(l) of the Clean Air Act
VII. Proposed Action
VIII. Statutory and Executive Order Reviews

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 NAAQS mean National Ambient Air Quality Standard.
    (iv) The initials SIP mean or refer to State Implementation Plan.
    (v) The word State means the State of Montana, unless the context
indicates otherwise.

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.
    (b). 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.
    Make sure to submit your comments by the comment period deadline
identified.

II. What is the purpose of this action?

    In this action, we are proposing approval of a change in the legal
designation of the Missoula area from nonattainment for CO to
attainment. We're proposing approval of the year 2000 attainment
emission inventory and the maintenance plan that is designed to keep
the area in attainment for CO for the next 13 years. We're also
proposing approval of the transportation conformity motor vehicle
emission budgets (MVEB) for 2000, 2010, and 2020, and we're proposing
approval of the 1993 and 1996 CO periodic emission inventories.
    We originally designated Missoula as nonattainment for CO under the
provisions of the 1977 CAA Amendments (see 43 FR 8962, March 3, 1978).
On November 15, 1990, the Clean Air Act Amendments of 1990 were enacted
(Pub. L. 101-549, 104 Stat. 2399, codified at 42 U.S.C. 7401-7671q).
Under section 107(d)(1)(C) of the Clean Air Act (CAA), we designated the

[[Page 20482]]

Missoula area as nonattainment for CO because the area had been
designated as nonattainment before November 15, 1990. Under section 186
of the CAA, Missoula was classified as a ``moderate'' CO nonattainment
area with a design value less than or equal to 12.7 parts per million
(ppm), and was required to attain the CO NAAQS by December 31, 1995.
See 56 FR 56694, November 6, 1991. Further information regarding this
classification and the accompanying requirements are described in the
``General Preamble for the Implementation of Title I of the Clean Air
Act Amendments of 1990.'' See 57 FR 13498, April 16, 1992.
    Under the CAA, we can change designations if acceptable data are
available and if certain other requirements are met. See CAA section
107(d)(3)(D). Section 107(d)(3)(E) of the CAA provides that the
Administrator may not promulgate a redesignation of a nonattainment
area to attainment unless:
    (i) The Administrator determines that the area has attained the
national ambient air quality standard;
    (ii) The Administrator has fully approved the applicable
implementation plan for the area under CAA section 110(k);
    (iii) The Administrator determines that the improvement in air
quality is due to permanent and enforceable reductions in emissions
resulting from implementation of the applicable implementation plan and
applicable Federal air pollutant control regulations and other
permanent and enforceable reductions;
    (iv) The Administrator has fully approved a maintenance plan for
the area as meeting the requirements of CAA section 175A; and,
    (v) The State containing such area has met all requirements
applicable to the area under section 110 and part D of the CAA.
    Before we can approve the redesignation request, we must decide
that all applicable SIP elements have been fully approved. Approval of
the applicable SIP elements may occur simultaneously with our final
approval of the redesignation request. That's why we are also proposing
approval of the 1993 and 1996 CO periodic emission inventories and the
year 2000 emission inventory.

III. What is the State's process to submit these materials to EPA?

    Section 110(k) of the CAA addresses our actions on submissions of
revisions to a SIP. The CAA requires States to observe certain
procedural requirements in developing SIP revisions for submittal to
us. Section 110(a)(2) of the CAA requires that each SIP revision be
adopted after reasonable notice and public hearing. This must occur
prior to the revision being submitted by a State to us.
    The Missoula City-County Air Pollution Control Board (MCCAPCB) held
a public hearing for the Missoula CO redesignation request and the
maintenance plan on November 18, 2004. The MCCAPCB adopted the Missoula
CO redesignation request and maintenance plan on March 7, 2005. The
Missoula CO redesignation request and maintenance plan were then
forwarded to the Montana Department of Environmental Quality (MDEQ) for
the State to conduct its public hearing. The MDEQ held a public hearing
for the Missoula CO redesignation request and the maintenance plan on
April 22, 2005 after which the SIP materials were forwarded to the
Governor for his submittal to EPA. These SIP revision materials were
submitted by the Governor to us on May 27, 2005.
    We have evaluated the Governor's submittal and have concluded that
the State met the requirements for reasonable notice and public hearing
under section 110(a)(2) of the CAA. By operation of law, under section
110(k)(1)(B) of the CAA, the Governor's May 27, 2005, submittal became
complete on November 27, 2005.

IV. EPA's Evaluation of the Missoula Redesignation Request and
Maintenance Plan

    Under the CAA, we can change designations of areas if acceptable
data are available and if certain other requirements are met. See CAA
section 107(d)(3)(D). We have reviewed the Missoula area's
redesignation request and maintenance plan (section 2.0) and believe
that approval of the request is warranted, consistent with the
requirements of CAA section 107(d)(3)(E) as presented in our section II
above.
    As we noted above, before we can approve the redesignation request,
we must decide that all applicable SIP elements have been fully
approved. Approval of the applicable SIP elements may occur
simultaneously with final approval of the redesignation request. That's
why we are also proposing to approve the 1993 and 1996 periodic
emission inventories and the year 2000 attainment inventory (to also
suffice as the 1999 periodic emission inventory.) The following are
descriptions of how the section 107(d)(3)(E) requirements are being
addressed.

(a) Redesignation Criterion: The Area Must Have Attained the Carbon
Monoxide (CO) NAAQS

    Section 107(d)(3)(E)(i) of the CAA states that for an area to be
redesignated to attainment, the Administrator must determine that the
area has attained the applicable NAAQS. As described in 40 CFR 50.8,
the national primary ambient air quality standards for carbon monoxide
are 9 parts per million (10 milligrams per cubic meter) for an 8-hour
average concentration not to be exceeded more than once per year, and
35 parts per million (40 milligrams per cubic meter) for a 1-hour
average concentration not to be exceeded more than once per year. 40
CFR 50.8 continues by stating that the levels of CO in the ambient air
shall be measured by a reference method based on 40 CFR part 50,
Appendix C, and designated in accordance with 40 CFR part 53 or an
equivalent method designated in accordance with 40 CFR part 53.
    Attainment of the CO standards is not a momentary phenomenon based
on short-term data. Instead, we consider an area to be in attainment if
each of the CO ambient air quality monitors in the area doesn't have
more than one exceedance of the relevant CO standard over a one-year
period. See 40 CFR 50.8 and 40 CFR 50, Appendix C. If any monitor in
the area's CO monitoring network records more than one exceedance of
the relevant CO standard during a one-year calendar period, then the
area is in violation of the CO NAAQS. In addition, our interpretation
of the CAA and EPA national policy \1\ has been that an area seeking
redesignation to attainment must show attainment of the CO NAAQS for at
least a continuous two-year calendar period. In addition, the area must
also continue to show attainment through the date that we promulgate
the redesignation in the Federal Register.
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    \1\ Refer to EPA's September 4, 1992, John Calcagni policy
memorandum entitled ``Procedures for Processing Requests to
Redesignate Areas to Attainment.''
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    Montana's CO redesignation request for the Missoula area is based
on an analysis of quality assured ambient air quality monitoring data
that are relevant to the redesignation request. As presented in section
2.1.1 of the maintenance plan, ambient air quality monitoring data for
consecutive calendar years 2000 through 2003 show a measured exceedance
rate of the CO NAAQS of 1.0 or less per year, per monitor, in the
Missoula nonattainment area. Further, we have reviewed ambient air
quality data from 2004 through December 2006 and the

[[Page 20483]]

Missoula area continues to show attainment of the CO NAAQS. All of
these data were collected and analyzed as required by EPA (see 40 CFR
50.8 and 40 CFR 50, Appendix C) and have been archived by the State in
our Air Quality System (AQS) national database. Therefore, we believe
the Missoula area has met the first component for redesignation:
demonstration of attainment of the CO NAAQS. We note that the State has
also committed, in the maintenance plan, to continue the necessary
operation of the CO monitor in compliance with all applicable Federal
regulations and guidelines.

(b) Redesignation Criterion: The Area Must Have Met All Applicable
Requirements Under Section 110 and Part D of the CAA and Title II of
the CAA

    To be redesignated to attainment, section 107(d)(3)(E)(v) requires
that an area must meet all applicable requirements under section 110
and part D of the CAA. We interpret section 107(d)(3)(E)(v) to mean
that for a redesignation to be approved by us, the State must meet all
requirements that applied to the subject area prior to or at the time
of the submission of a complete redesignation request. In our
evaluation of a redesignation request, we don't need to consider other
requirements of the CAA that became due after the date of the
submission of a complete redesignation request.
1. CAA Section 110 Requirements
    On January 10, 1980, we approved revisions to Montana's SIP as
meeting the requirements of section 110(a)(2) of the CAA (see 45 FR
2034). Although section 110 of the CAA was amended in 1990, most of the
changes were not substantial. Thus, we have determined that the SIP
revisions approved in 1980 continue to satisfy the requirements of
section 110(a)(2). In addition, we have analyzed the SIP elements we
are approving as part of this action, and we have determined they
comply with the relevant requirements of section 110(a)(2).
2. Part D Requirements
    Before the Missoula ``moderate'' CO nonattainment area may be
redesignated to attainment, the State must have fulfilled the
applicable requirements of part D. Under part D, an area's
classification indicates the requirements to which it will be subject.
Subpart 1 of part D sets forth the basic nonattainment requirements
applicable to all nonattainment areas, whether classified or
nonclassifiable. Subpart 3 of part D contains specific provisions for
``moderate'' CO nonattainment areas.
    The relevant subpart 1 requirements are contained in sections
172(c) and 176. Our General Preamble (see 57 FR 13529, 13533, April 16,
1992) provides EPA's interpretations of the CAA requirements for
``moderate'' CO areas. The General Preamble (see 57 FR 13530, et seq.)
provides that the applicable requirements of CAA section 172 are
172(c)(3) (emissions inventory), 172(c)(5) (new source review
permitting program), 172(c)(7) (the section 110(a)(2) air quality
monitoring requirements), and 172(c)(9) (contingency measures). It is
also worth noting that we interpreted the requirements of sections
172(c)(2) (reasonable further progress--RFP) and 172(c)(6) (other
measures) as being irrelevant to a redesignation request because they
only have meaning for an area that is not attaining the standard. See
EPA's September 4, 1992, memorandum entitled, ``Procedures for
Processing Requests to Redesignate Areas to Attainment'', and the
General Preamble, 57 FR at 13564, dated April 16, 1992. Finally, the
State has not sought to exercise the options that would trigger
sections 172(c)(4) (identification of certain emissions increases) and
172(c)(8) (equivalent techniques). Thus, these provisions are also not
relevant to this redesignation request.
    The relevant subpart 3 provisions were created when the CAA was
amended on November 15, 1990 and appear in section 187 of the CAA. The
new CAA requirements for a CO nonattainment area, classified as
``moderate'' with a design value of 12.7 ppm or less, that are
applicable to Missoula are a 1990 base year inventory (CAA section
187(a)(1)), contingency provisions (CAA section 187(a)(3)), and
periodic emission inventories (CAA section 187(a)(5)).
    A. Relevant CAA subpart 1 requirements.
    1. Emissions Inventory. For the CAA section 172(c)(3) emissions
inventory requirement, the State submitted a 1990 base year CO
emissions inventory for the Missoula area on July 18, 1995 which met
the requirements of section 172(c)(3) of the CAA. We approved this
inventory on December 15, 1997 (62 FR 65613).
    2. New Source Review (NSR) and Prevention of Significant
Deterioration (PSD). For the CAA section 172(c)(5) New Source Review
(NSR) requirements, the CAA requires all nonattainment areas to meet
several requirements regarding NSR, including provisions to ensure that
increased emissions will not result from any new or modified stationary
major sources and a general offset rule. The State of Montana has a
fully-approved NSR program (60 FR 36715, July 18, 1995.) The State also
has a fully approved PSD program (60 FR 36715, July 18, 1995) that will
apply, instead of nonattainment NSR, if we approve the redesignation to
attainment.
    3. Air Quality Monitoring Requirements. For the CAA section
172(c)(7) provisions (compliance with the CAA section 110(a)(2) Air
Quality Monitoring Requirements), our interpretations are presented in
the General Preamble (57 FR 13535). CO nonattainment areas are to meet
the ``applicable'' air quality monitoring requirements of section
110(a)(2) of the CAA. We have determined that the Missoula area has met
the applicable air quality monitoring requirements of section 110(a)(2)
of the CAA. See our descriptions in section IV.A above.
    4. Contingency Measures. Section 172(c)(9) of the CAA requires the
submittal of contingency measures to be implemented in the event that
an area fails to make reasonable further progress or to attain the
NAAQS by the date applicable (which for a CO nonattainment area, with a
design value of less than 12.7 ppm, was December 31, 1995.) To meet
this requirement the State submitted a contingency measure, involving
residential woodburning devices, on March 2, 1994. We approved this CO
contingency measure on December 13, 1994 (59 FR 64133).
    5. Conformity. Section 176 of the CAA contains requirements related
to conformity. Although EPA's regulations (see 40 CFR 51.390) require
that states adopt transportation conformity provisions in their SIPs
for areas designated nonattainment or subject to an EPA-approved
maintenance plan, we have decided that a transportation conformity SIP
is not an applicable requirement for purposes of evaluating a
redesignation request under section 107(d) of the CAA. This decision is
reflected in EPA's 1996 approval of the Boston carbon monoxide
redesignation. (See 61 FR 2918, January 30, 1996.)
    B. Relevant CAA subpart 3 requirements.
    1. Emissions Inventory. For the CAA section 187(a)(1) emissions
inventory requirement, the State submitted a 1990 base year CO
emissions inventory for the Missoula area on July 18, 1995 which met
the requirements of section 187(a)(1) of the CAA. We approved this
inventory on December 15, 1997 (62 FR 65613).
    2. Periodic emission inventories. For the CAA section 187(a)(5)
periodic

[[Page 20484]]

emissions inventory requirement, the State submitted CO periodic
emission inventories (PEI) for 1993 and 1996 on January 27, 2000. In
addition, the State submitted a year 2000 CO emission inventory, on
July 19, 2004, that qualifies for the 1999 PEI and is also the basis
for the attainment year 2000 CO emission inventory that is part of the
State's Missoula CO maintenance plan. We have reviewed these CO
periodic emission inventories and have determined they contain
comprehensive information with respect to point, area, non-road, and
on-road mobile sources and were prepared in accordance with EPA
guidance. We are proposing approval of the 1993 PEI, the 1996 PEI, and
the year 2000 attainment inventory (for the 1999 PEI requirement) in
conjunction with this action's proposed approval of the Missoula CO
redesignation to attainment and maintenance plan.
    3. CAA Title II requirements. The relevant CAA Title II requirement
is contained in section 211(m)(1) which requires the implementation of
an oxygenated fuels program for CO areas with a design value of 9.5 ppm
or greater.
    A. Title II, Part A of the CAA: Oxygenated fuels program (CAA
section 211(m)(1)).
    Section 211(m)(1) of the CAA requires the submittal of a SIP
revision to implement an oxygenated fuels program for CO nonattainment
areas with a design value of 9.5 ppm or greater. To address this
requirement, the State submitted a SIP revision on November 6, 1992 for
the implementation of an oxygenated fuels program in Missoula County.
EPA approved this SIP revision on November 8, 1994 (see 59 FR 55585).

(c) Redesignation Criterion: The Area Must Have a Fully Approved SIP
Under Section 110(k) of the CAA

    Section 107(d)(3)(E)(ii) of the CAA states that for an area to be
redesignated to attainment, it must be determined that the
Administrator has fully approved the applicable implementation plan for
the area under section 110(k).
    As noted above, EPA previously approved SIP revisions based on the
pre-1990 CAA as well as SIP revisions required under the 1990
amendments to the CAA. In this action, EPA is proposing approval of the
Missoula area's 1993 periodic CO emissions inventory, the 1996 periodic
CO emissions inventory, and the 2000 CO emission inventory (as meeting
the 1999 periodic emissions inventory requirement). Thus, with our
final approval of these SIP revisions, we will have fully approved the
Missoula area's CO element of the SIP under section 110(k) of the CAA.

(d) Redesignation Criterion: The Area Must Show That the Improvement in
Air Quality Is Due to Permanent and Enforceable Emissions Reductions

    Section 107(d)(3)(E)(iii) of the CAA provides that for an area to
be redesignated to attainment, the Administrator must determine that
the improvement in air quality is due to permanent and enforceable
reductions in emissions resulting from implementation of the applicable
implementation plan, implementation of applicable Federal air pollutant
control regulations, and other permanent and enforceable reductions.
    The CO emissions reductions for the Missoula area, that are further
described in section 2.3 of the maintenance plan, were achieved
primarily through an oxygenated fuels program, Federal Motor Vehicle
Control Program, residential woodburning regulations, changes in the
transportation infrastructure involving the reconstruction of the
Brooks/South/Russell (B/S/R) intersection, and outdoor open burning
regulations. These five control strategies are fully discussed in
section 2.3 of the maintenance plan and are summarized below.
    1. Oxygenated Fuels. As described in section 2.3.2.1 of the
maintenance plan, since November of 1992, all gasoline sold within the
Missoula CO nonattainment area must have a minimum oxygen content of
2.7% by weight from November 1st through the last day of February each
year. The use of oxygenates in gasoline helps provide additional oxygen
in the fuel for better combustion of the fuel in the engine and a
decrease in tailpipe CO emissions.
    2. Federal Motor Vehicle Control Program (FMVCP). Section 2.3.2.2
of the maintenance plan discusses the FMVCP which involves Federal
provisions that require vehicle manufacturers to meet more stringent
vehicle emission limitations for new vehicles in future years. These
emission limitations are phased in (as a percentage of new vehicles
manufactured) over a period of years. As new, lower emitting vehicles
replace older, higher emitting vehicles (``fleet turnover''), emission
reductions are realized for a particular area such as Missoula.
    3. Residential Woodburning. As described in section 2.3.2.3 of the
maintenance plan, in order to reduce the amount of CO emissions from
residential woodburning, Missoula adopted progressively more stringent
solid fuel burning device regulations. Currently, the only new solid
fuel burning devices permitted in Missoula are pellet stoves and the
regulations also require that most woodstoves be removed at the time of
sale of a property.
    4. Transportation Infrastructure. Section 2.3.2.4 of the
maintenance plan describes the changes in transportation infrastructure
that specifically address the B/S/R intersection. Violations of the CO
NAAQS were occurring at the B/S/R intersection in the 1980s and an
initial intersection reconstruction was completed in 1985. This effort
involved restricting left turn lanes and adding right turn and
departure lanes. The CO designation of nonattainment for Missoula in
1991 was again tied to monitoring data near the B/S/R intersection. The
final reconstruction project involved the realignment of South Avenue
such that South Avenue no longer enters the intersection. This
construction effort was scheduled to be completed by the end of 2005.
The South Avenue realignment simplified the intersection, reducing the
projected peak-hour delay from 120 seconds to 20 seconds, and also
allowed for the synchronization of all traffic lights along Brooks
Street from Reserve to Mount. This reduces congestion along the whole
corridor.
    5. Outdoor Burning. Section 2.3.2.5 of the maintenance plan
describes the provisions of Missoula's outdoor burning regulations.
These regulations reduce the impact of outdoor burning, especially
during December, January, and February, by requiring a permit for each
burn, allowing only the burning of untreated lumber and natural
vegetation, requiring burners to call the Outdoor Burning Hotline to
confirm if any burning or air quality restrictions are in effect,
establishing burning seasons to reduce the generation of smoke, and
prohibiting outdoor burning during December, January, and February
except for ceremonial bonfires, emergency burning, and essential
wintertime burning.
    We have evaluated the various Local, State, and Federal control
measures, the original 1990 base year CO emission inventory (62 FR
65613, December 15, 1997), the 1993 periodic CO emission inventory, the
1996 periodic CO emission inventory, and the 2000 attainment year CO
inventory that was provided with the State's May 27, 2005 submittal and
have concluded that the improvement in air quality in the Missoula
nonattainment area has resulted from emission reductions that are
permanent and enforceable.

[[Page 20485]]

(e) Redesignation Criterion: The Area Must Have a Fully Approved
Maintenance Plan Under Section 175A of the CAA

    Section 107(d)(3)(E)(iv) of the CAA provides that for an area to be
redesignated to attainment, the Administrator must have fully approved
a maintenance plan for the area meeting the requirements of section
175A of the CAA.
    Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
The maintenance plan must demonstrate continued attainment of the
applicable NAAQS for at least ten years after the Administrator
approves a redesignation to attainment. Eight years after the
promulgation of the redesignation, the State must submit a revised
maintenance plan that demonstrates continued attainment for a
subsequent ten-year period following the initial ten-year maintenance
period. To address the possibility of future NAAQS violations, the
maintenance plan must contain contingency measures, with a schedule for
adoption and implementation, that are adequate to assure prompt
correction of a violation. In addition, we issued further maintenance
plan interpretations in the ``General Preamble for the Implementation
of Title I of the Clean Air Act Amendments of 1990'' (57 FR 13498,
April 16, 1992), ``General Preamble for the Implementation of Title I
of the Clean Air Act Amendments of 1990; Supplemental'' (57 FR 18070,
April 28, 1992), and the EPA guidance memorandum entitled ``Procedures
for Processing Requests to Redesignate Areas to Attainment'' from John
Calcagni, Director, Air Quality Management Division, Office of Air
Quality and Planning Standards, to Regional Air Division Directors,
dated September 4, 1992.
    In this Federal Register action, EPA is proposing approval of the
maintenance plan for the Missoula nonattainment area because we have
determined, as detailed below, that the State's maintenance plan meets
the requirements of section 175A and is consistent with the documents
referenced above. Our analysis of the pertinent maintenance plan
requirements, with reference to the Governor's May 27, 2005, submittal,
is provided as follows:
1. Emissions Inventories--Attainment Year and Projections
    EPA's interpretations of the CAA section 175A maintenance plan
requirements are generally provided in the General Preamble (see 57 FR
13498, April 16, 1992) and the September 4, 1992, Calcagni Memorandum
referenced above. Under our interpretations, areas seeking to
redesignate to attainment for CO may demonstrate future maintenance of
the CO NAAQS either by showing that future CO emissions will be equal
to or less than the attainment year emissions or by providing a
modeling demonstration.
    The maintenance plan that the Governor submitted on May 27, 2005,
includes comprehensive inventories of CO emissions for the Missoula
area. These inventories include emissions from stationary point
sources, area sources, non-road mobile sources, and on-road mobile
sources. The maintenance plan uses a year 2000 attainment inventory and
includes interim-year projections with a final maintenance year of
2020. More detailed descriptions of the 2000 attainment year inventory
and the projected inventories are documented in section 2.5.1, section
2.5.2.2, and Appendix D of the maintenance plan. The State's submittal
contains detailed emission inventory information that was prepared in
accordance with EPA guidance. Summary emission figures from the 2000
attainment year, the interim projected years, and the final maintenance
year of 2020 are provided in Table IV-1 below.

                           Table IV-1.--CO Emission Inventories for the Missoula Area
                                       [All figures in tons per day of CO]
----------------------------------------------------------------------------------------------------------------
                           Year                               2000       2005       2010       2015       2020
----------------------------------------------------------------------------------------------------------------
Point Sources............................................       0.30       0.33       0.37       0.41       0.46
Area Sources.............................................       6.62       6.37       6.10       5.88       5.69
Non-Road Mobile Sources..................................       5.06       5.73       6.14       6.52       7.01
On-Road Mobile Sources...................................      44.86      32.73      27.10      24.97      22.98
                                                          ------------------------------------------------------
    Total................................................      56.83      45.16      39.71      37.78      36.14
----------------------------------------------------------------------------------------------------------------

2. Demonstration of Maintenance--Projected Inventories and CAL3QHC
Intersection Modeling
    As we presented above, total CO emissions were projected forward by
the State for the years 2005, 2010, 2015, and 2020. We note the State's
approach for developing the projected inventories follows EPA guidance
on projected emissions and we believe they are acceptable.\2\ Further
information regarding these CO emission inventories is also provided in
section 2.5.2.2 and in Appendix D of the maintenance plan. The
projected inventories show that CO emissions are not estimated to
exceed the 2000 attainment level during the time period of 2000 through
2020 and, therefore, the Missoula area has satisfactorily demonstrated
maintenance.
    In addition to the emission inventory projections, the State also
performed ``hot-spot'' modeling to evaluate predicted CO concentrations
at the B/S/R intersection. This effort involved the CAL3QHC-R
intersection model and considered meteorological data, relevant CO
emission contributions from point, area, non-road, and on-road sources,
and information specific to the B/S/R intersection such as traffic
patterns and intersection geometry. Consistent with EPA guidance, the
State modeled CO concentrations at 60 receptor sites around the
intersection and at the location of the CO ambient air quality
monitoring site at the B/S/R intersection. The years modeled were 2000,
2005, 2010, and 2020. We note this modeling effort was consistent with
our modeling guidance.
---------------------------------------------------------------------------

    \2\ ``Use of Actual Emissions in Maintenance Demonstrations for
Ozone and Carbon Monoxide (CO) Nonattainment Areas'', signed by D. Kent
Berry, Acting Director, Air Quality Management Division, November 30, 1993.
---------------------------------------------------------------------------

    The results of the State's modeling for 2000, 2005, 2010, and 2020
are presented in section 2.5.2.1 and Appendix C of the maintenance plan
and in Table IV-2 below.

[[Page 20486]]

     Table IV-2.--CAL3QHC-R Modeled CO Concentrations for the B/S/R
                              Intersection
                  [All values are in parts per million]
------------------------------------------------------------------------
                                 2000       2005       2010       2020
------------------------------------------------------------------------
First Maximum 8-hour CO            11.8        8.9        5.4        4.5
 Value......................
Second Maximum 8-hour CO           10.7        8.0        4.4        3.6
 Value......................
First Maximum 8-hour CO             7.0        5.4        3.2        2.5
 Value at the Monitor
 Location...................
Second Maximum 8-hour CO            6.7        5.1        2.9        2.4
 Value at the Monitor
 Location...................
------------------------------------------------------------------------

    As shown, the CAL3QHC-R model predicted an exceedance of the CO
NAAQS in 2000 at a modeling receptor location near the intersection. We
consider this to be a conservative estimate by the model. For
comparison, for 2000 the model predicted first maximum 8-hour and
second maximum 8-hour CO concentrations of 7.0 and 6.7 ppm,
respectively, at the ambient air quality monitoring site. However,
actual ambient air quality data from the monitor for 2000 were a first
maximum 8-hour value of 3.9 ppm and second maximum 8-hour value of 3.3
ppm (ref. section 2.1.1 and Figure 2-3 of the maintenance plan.)
    Based on the information provided in sections 2.5.2.1 and 2.5.2.2,
the maintenance plan concludes that maintenance of the CO NAAQS is
demonstrated. Specifically, the actual monitored values for 2000
indicate no exceedances of the CO NAAQS for the Missoula area, the
modeled CO values for 2005, 2010, and 2020 are less than the 8-hour CO
NAAQS (9.0 ppm), and, as stated earlier in this action, predicted CO
emissions for 2005, 2010, and 2020 are all less than the attainment
year levels of 2000.
    We have reviewed the State's CAL3QHC-R modeling data and results
and the attainment year and projected years CO emission inventory
information, and have concluded that the State has satisfactorily
demonstrated maintenance of the CO NAAQS through 2020.
3. Monitoring Network and Verification of Continued Attainment
    Continued attainment of the CO NAAQS in the Missoula area depends,
in part, on the State's efforts to track indicators throughout the
maintenance period. This requirement is met in section 2.5.3 of the
Missoula CO maintenance plan. In section 2.5.3 the State commits to
review mobile source emission inventory data and compare that
information to the emission inventory data in the Missoula CO
maintenance plan. In section 2.5.3 the State also commits to continue
the operation of the CO monitor in the Missoula area, specifically at
the B/S/R intersection, and to annually review this monitoring network
and make changes as appropriate.
    Based on the above, we are approving these commitments as
satisfying the relevant requirements and note that this approval will
render the State's commitments federally enforceable.
4. Contingency Plan
    Section 175A(d) of the CAA requires that a maintenance plan include
contingency provisions. To meet this requirement, the State has
identified appropriate contingency measures along with a schedule for
the development and implementation of such measures.
    As stated in section 2.5.5 and 2.5.5.4 of the Missoula CO
maintenance plan, the contingency measures for the Missoula area will
be triggered by a violation of the CO NAAQS.
    Section 2.5.5.4 states that contingency measures contained in the
Missoula City-County Air Pollution Control Plan will be implemented
within 60 days of notification by the MDEQ and EPA that the area has
violated the CO NAAQS. If those measures are not adequate, the Missoula
City-County Air Pollution Control Board (MCCAPCB), in conjunction with
the Air Quality Advisory Council (AQAC), will initiate a process to
begin evaluating potential contingency measures. The Missoula City-
County Health Department (MCCHD) and the AQAC will present
recommendations to the MCCAPCB within 180 days of notification. The
MCCAPCB will then hold a public hearing to consider the contingency
measures recommended, along with any other contingency measures that
the MCCAPCB believes may be appropriate to effectively address the
violation of the CO NAAQS. The necessary contingency measures will be
adopted and implemented within one year of the MCCHD being notified of
the CO NAAQS violation.
    The potential contingency measures that are identified in section
2.5.5.1 of the Missoula CO maintenance plan include (a) expanding the
2.7% oxygenated fuels program in Missoula County to months outside of
the current program time frame of November 1st through the end of
February, (b) further restricting woodstove burning, (c) increasing the
oxygenated fuels content to 3.1% by weight, and (d) constructing
transportation projects and implementing transportation control
measures. A more complete description of the triggering mechanism and
these contingency measures can be found in section 2.5.5 of the
Missoula CO maintenance plan.
    Based on the above, we find that the contingency plan provided in
the Missoula CO maintenance plan meets the requirements of section
175A(d) of the CAA.
5. Subsequent Maintenance Plan Revisions
    In accordance with section 175A(b) of the CAA, the MCCHD and MDEQ
have committed to submit a revised maintenance plan eight years after
our approval of the redesignation. This provision for revising the
maintenance plan is contained in section 2.5.7 of the Missoula CO
maintenance plan.

V. EPA's Evaluation of the Transportation Conformity Requirements

    One key provision of our conformity regulation requires a
demonstration that emissions from the transportation plan and
Transportation Improvement Program are consistent with the emissions
budget(s) in the SIP (40 CFR sections 93.118 and 93.124). The emissions
budget is defined as the level of mobile source emissions relied upon
in the attainment or maintenance demonstration to maintain compliance
with the NAAQS in the nonattainment or maintenance area. The rule's
requirements and EPA's policy on emissions budgets are found in the
preamble to the November 24, 1993, transportation conformity rule (58
FR 62193-96) and in the sections of the rule referenced above.
    Section 2.5.6 of the Missoula CO maintenance plan defines the CO
motor vehicle emissions budgets in the Missoula CO maintenance area as
44.86 tons per day for 2005 through 2009, 43.22 tons per day for 2010
through 2019, and 42.67 tons per day for 2020 and beyond. As we explain
more fully below, we view these as the budgets for 2000, 2010, and 2020
respectively.

[[Page 20487]]

    Under our conformity rules, a motor vehicle emissions budget is
established for a given year, not for a range of years. This is because
the motor vehicle emissions budget reflects the inventory value for
motor vehicle emissions in a given year, plus, potentially, any safety
margin in that year. (We explain the concept of safety margin more
fully below.) It is not possible to specify the same motor vehicle
emissions budget for a range of years absent specific analysis
supporting the derivation of that budget for each year in the range. As
a practical matter, this is not usually important because our
conformity rules also say that a motor vehicle emissions budget for a
particular year applies for conformity analyses of emissions in that
year and all subsequent years before the next budget year. See 40 CFR
93.118(b)(1)(ii) (``Emissions in years for which no motor vehicle
emissions budget(s) are specifically established must be less than or
equal to the motor vehicle emissions budget(s) established for the most
recent prior year.'').
    The maintenance plan's ``2005 through 2009'' motor vehicle
emissions budget in fact is derived directly from the year 2000
inventory value for on-road vehicle emissions. It is apparent from the
maintenance plan that MCCHD and MDEQ were not relying on 2005 inventory
numbers to establish the ``2005 through 2009'' budget, and thus, it is
not truly a 2005 budget. We assume the maintenance plan designates this
as a 2005 to 2009 budget because the maintenance plan was adopted in
2005, and the years 2000 through 2004 had already passed. However,
because it was derived from 2000 values, the ``2005 through 2009''
budget is actually a 2000 budget, and we will refer to it as such in
the remainder of this proposal. Consistent with our discussion above,
the 2000 budget applies for conformity analyses of emissions in the
year 2000 and all subsequent years before the next budget year; i.e.,
since the next budget year is 2010, the 2000 budget applies for
analyses of years 2000 through 2009.
    Similarly, the ``2010 through 2019'' and ``2020 and beyond''
budgets were derived from, respectively, 2010 and 2020 inventory values
for on-road vehicle emissions and available safety margin. Thus, we
will refer to these as the 2010 and 2020 budgets in the remainder of
this proposal.
    For the Missoula CO maintenance plan, the ``safety margin'' is the
difference between the attainment year (2000) total emissions and the
projected future year's total emissions. Part or all of the safety
margin may be added to projected mobile source CO emissions to arrive
at a motor vehicle emissions budget to be used for transportation
conformity purposes. The safety margins, less one ton per day, were
added to projected mobile source CO emissions for 2010, and 2020. The
derivation and determination of safety margins and motor vehicle
emissions budgets for the Missoula CO maintenance plan is further
illustrated in Table V-1 below and in section 2.5.6, Table 2-7 of the
maintenance plan:

                  Table V-1.--Mobile Sources Emissions, Safety Margins, and Motor Vehicle Emissions Budgets in Tons of CO per Day (TPD)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Mobile sources       Total                                                                     Motor vehicle
                   Year                        emissions       emissions                        Math                         Margin of       emissions
                                                 (TPD)           (TPD)                                                     safety (TPD)    budget (TPD)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2000......................................           44.86           56.83  ............................................             N/A           44.86
2010......................................           27.10           39.71  56.83-39.71 = 17.12.........................           16.12           43.22
                                                                            17.12-1 = 16.12.............................
                                                                            27.10+16.12 = 43.22.........................
2020......................................           22.98           36.14  56.83-36.14 = 20.69.........................           19.69          42.67
                                                                            20.69-1 = 19.69.............................
                                                                            22.98+19.69 = 42.67.........................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: N/A = Not Applicable.

    Our analysis indicates that the above figures are consistent with
maintenance of the CO NAAQS throughout the maintenance period.
Therefore, we are approving the 44.86 tons per day budget for 2000,
43.22 tons per day budget for 2010, and 42.67 tons per day budget for
2020 for the Missoula area.
    Pursuant to section 93.118(e)(4) of EPA's transportation conformity
rule, as amended, EPA must determine the adequacy of submitted mobile
source emissions budgets. EPA reviewed the Missoula CO maintenance plan
budgets for adequacy using the criteria in 40 CFR 93.118(e)(4), and
determined that the budgets were adequate for conformity purposes.
EPA's adequacy determination was made in a letter to the MDEQ on May 4,
2006, and was announced in the Federal Register on June 1, 2006 (71 FR
31181). As a result of this adequacy finding, the budgets took effect
for conformity determinations in the Missoula area on June 16, 2006.
However, we are not bound by that determination in acting on the
maintenance plan.\3\
---------------------------------------------------------------------------

    \3\ In its adequacy determination, EPA listed and found adequate
budgets for 2005, 2010, and 2021. The listed years should have been
2000, 2010, and 2020, consistent with our discussion above. Assuming
we do not change this proposal in response to public comment, the
final approved budgets will be for years 2000, 2010, and 2020.
---------------------------------------------------------------------------

VI. Consideration of Section 110(l) of the Clean Air Act

    Section 110(l) of the CAA states that a SIP revision cannot be
approved if the revision would interfere with any applicable
requirement concerning attainment and reasonable further progress
towards attainment of a NAAQS or any other applicable requirement of
the CAA. The Missoula CO maintenance plan will not interfere with
attainment, reasonable further progress, or any other applicable
requirement of the CAA.

VII. Proposed Action

    In this action, EPA is proposing approval of the request for
redesignation from nonattainment to attainment for CO for the Missoula
area, the Missoula area's maintenance plan, the 1993 PEI, the 1996 PEI,
the year 2000 attainment inventory (which fulfills the 1999 PEI
obligation), and the transportation conformity CO motor vehicle
emission budgets of 44.86 tons per day for 2000, 43.22 tons per day for
2010, and 42.67 tons per day for 2020.
    Submit your comments, identified by Docket ID No. EPA-R08-OAR-2006-
0163, by one of the methods identified above at the front of this
proposed rule. In deciding on our final action, we will consider your
comments if they are received before May 25, 2007. EPA will

[[Page 20488]]

address all public comments in a subsequent final rule based on this
proposed rule. EPA will not institute a second comment period on this
action. Any parties interested in commenting must do so at this time.

VIII. Statutory and Executive Order Reviews

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
proposed action is not a ``significant regulatory action'' and
therefore is not subject to review by the Office of Management and
Budget. For this reason, this action is also not subject to Executive
Order 13211, ``Actions Concerning Regulations That Significantly Affect
Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This
proposed action merely proposes to approve state law as meeting Federal
requirements and imposes no additional requirements beyond those
imposed by state law. Accordingly, the Administrator certifies that
this proposed rule will not have a significant economic impact on a
substantial number of small entities under the Regulatory Flexibility
Act (5 U.S.C. 601 et seq.). Because this rule proposes to approve pre-
existing requirements under state law and does not impose any
additional enforceable duty beyond that required by state law, it does
not contain any unfunded mandate or significantly or uniquely affect
small governments, as described in the Unfunded Mandates Reform Act of
1995 (Pub. L. 104-4).
    This proposed rule also does not have tribal implications because
it will not have a substantial direct effect on one or more Indian
tribes, 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, as specified by Executive
Order 13175 (59 FR 22951, November 9, 2000). This action also does not
have Federalism implications because it does not have a substantial
direct effect 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 (64 FR 43255, August 10, 1999). This action
merely proposes to approve a state rule implementing a Federal
standard, and does not alter the relationship or the distribution of
power and responsibilities established in the Clean Air Act. This
proposed rule also is not subject to Executive Order 13045 ``Protection
of Children from Environmental Health Risks and Safety Risks''
(62 FR 19885, April 23, 1997), because it proposes to approve a state rule
implementing a Federal standard.
    In reviewing SIP submissions, EPA's role is to approve state
choices, provided that they meet the criteria of the Clean Air Act. In
this context, in the absence of a prior existing requirement for the
State to use voluntary consensus standards (VCS), EPA has no authority
to disapprove a SIP submission for failure to use VCS. It would thus be
inconsistent with applicable law for EPA, when it reviews a SIP
submission, to use VCS in place of a SIP submission that otherwise
satisfies the provisions of the Clean Air Act. Thus, the requirements
of section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (15 U.S.C. 272 note) do not apply. This proposed rule does
not impose an information collection burden under the provisions of the
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide,
Intergovernmental relations, Reporting and recordkeeping requirements.

40 CFR Part 81

    Air pollution control, National parks, Wilderness areas.

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

    Dated: April 17, 2007.
Kerrigan G. Clough,
Acting Regional Administrator, Region 8.
[FR Doc. E7-7900 Filed 4-24-07; 8:45 am]
BILLING CODE 6560-50-P 

 
 


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