Document ID: EPA-R08-OAR-2012-0347-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality Implementation Plans; Approvals and Promulgations: Montana; Interstate Transport of Pollution for the 2006 PM2.5 NAAQS
Posted Date: 2013-05-13T04:00Z

[Federal Register Volume 78, Number 92 (Monday, May 13, 2013)]
[Proposed Rules]
[Pages 27883-27888]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-11292]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2012-0347; FRL-9813-3]

Approval and Promulgation of State Implementation Plans; State of 
Montana; Interstate Transport of Pollution for the 2006 PM2.5 NAAQS

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to partially approve and partially disapprove 
portions of a State Implementation Plan (SIP) submission from the State 
of Montana that are intended to demonstrate that its SIP meets certain 
interstate transport requirements of the Clean Air Act (``Act'' or 
``CAA'') for the 2006 fine particulate matter (``PM2.5'') 
National Ambient Air Quality Standards (``NAAQS''). This submission 
addresses the requirement that Montana's SIP contain adequate 
provisions to prohibit air emissions from adversely affecting another 
state's air quality through interstate transport. Specifically, EPA is 
proposing to partially approve and partially disapprove the portion of 
the Montana SIP submission that addresses the CAA requirement 
prohibiting emissions from Montana sources from significantly 
contributing to nonattainment of the 2006 PM2.5 NAAQS in any 
other state or interfering with maintenance of the 2006 
PM2.5 NAAQS by any other state. EPA is also proposing to 
partially approve and partially disapprove the portion of Montana's 
submission that addresses the CAA requirement that SIPs contain 
provisions to insure compliance with specific other CAA requirements 
relating to interstate and international pollution abatement. The 
partial disapprovals, if finalized, would not trigger an obligation for 
EPA to promulgate a Federal Implementation Plan (FIP) to address these 
interstate transport requirements as EPA is determining that the 
existing SIP is adequate to meet the specific CAA requirements.

DATES: Comments must be received on or before June 12, 2013.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2012-0347, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     Email: clark.adam@epa.gov.
     Fax: (303) 312-6064 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Carl Daly, Director, Air Program, Environmental 
Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129.
     Hand Delivery: Carl Daly, Director, Air Program, 
Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129. Such deliveries are only accepted 
Monday through Friday, 8:00 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-
2012-0347. 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 email. 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 email comment directly to EPA, without 
going through http://www.regulations.gov, your email 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 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, Mailcode 8P-AR, 1595 
Wynkoop, 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, 8:00 a.m. 
to 4:00 p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Adam Clark, Air Program, U.S. 
Environmental Protection Agency, Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129, (303) 312-7104, 
clark.adam@epa.gov.

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 initials CAIR mean or refer to the Clean Air Interstate 
Rule
    (iii) The initials CSAPR mean or refer to the Cross-State Air 
Pollution Rule
    (iv) The words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.

[[Page 27884]]

    (v) The initials SIP mean or refer to State Implementation Plan.
    (vi) The initials MDEQ mean or refer to the Montana Department 
of Environmental Quality.
    (vii) The words Montana and State mean the State of Montana.

Table of Contents

I. General Information
II. Background
    A. 2006 PM2.5 NAAQS and Interstate Transport
    B. Rules Addressing Interstate Transport for the 2006 PM2.5 
NAAQS in the Eastern United States
    C. EPA Guidance for SIP Submissions to Address Interstate 
Transport for the 2006 PM2.5 NAAQS
III. Montana's Submittal
IV. EPA's Evaluation
    A. Identification of Nonattainment and Maintenance Receptors
    B. Evaluation of Significant Contribution to Nonattainment
    C. Evaluation of Interference With Maintenance
    D. Evaluation of Montana's SIP With regard to CAA section 
110(a)(2)(D)(ii)
V. Proposed Action
VI. Statutory and Executive Order Reviews

I. General Information

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

    1. Submitting CBI. Do not submit CBI to EPA through http://www.regulations.gov or email. 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. Background

A. 2006 PM2.5 NAAQS and Interstate Transport

    Section 110(a)(2)(D)(i) of the CAA identifies four distinct 
elements related to the evaluation of impacts of interstate transport 
of air pollutants. In this action for the state of Montana, EPA is 
addressing the first two elements of section 110(a)(2)(D)(i) with 
respect to the 2006 PM2.5 NAAQS.\1\ The first element of 
section 110(a)(2)(D)(i) requires that each SIP for a new or revised 
NAAQS contain adequate provisions to prohibit any source or other type 
of emissions activity within the state from emitting air pollutants 
that will ``contribute significantly to nonattainment'' of the NAAQS in 
another state. The second element of CAA section 110(a)(2)(D)(i) 
requires that each SIP for a new or revised NAAQS contain adequate 
provisions to prohibit any source or other type of emissions activity 
in the state from emitting pollutants that will ``interfere with 
maintenance'' of the applicable NAAQS in any other state.
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    \1\ This proposed action does not address the two elements of 
the transport SIP provision (in CAA section 110(a)(2)(D)(i)(II)) 
regarding interference with measures required to prevent significant 
deterioration of air quality or to protect visibility in another 
state. We will act on these elements in a separate rulemaking.
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    EPA is also addressing the requirements of section 110(a)(2)(D)(ii) 
with respect to the 2006 PM2.5 NAAQS. Section 
110(a)(2)(D)(ii) requires each SIP to contain adequate provisions to 
insure compliance with the applicable requirements of sections 126 and 
115 of the Act. Section 126 pertains to notification to nearby states 
and petitions from states to EPA regarding interstate transport of 
pollution. Section 115 pertains to international transport of 
pollution.

B. EPA Rules Addressing Interstate Transport for the 2006 PM2.5 NAAQS 
in the Eastern United States

    EPA has addressed the requirements of section 110(a)(2)(D)(i)(I) 
for many states in the eastern portion of the country in three 
regulatory actions.\2\ Most recently, EPA published the final Cross 
State Air Pollution Rule (``CSAPR'' or ``Transport Rule'') to address 
the first two elements of CAA section 110(a)(2)(D)(i)(I) in the Eastern 
United States with respect to the 2006 PM2.5 NAAQS, the 1997 
PM2.5 NAAQS, and the 1997 8-hour ozone NAAQS (August 8, 
2011, 76 FR 48208). CSAPR was intended to replace the earlier Clean Air 
Interstate Rule (CAIR) which was judicially remanded.\3\ See North 
Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008). On August 21, 2012, a 
panel of the U.S. Court of Appeals for the D.C. Circuit issued a 
decision to vacate the CSAPR. See EME Homer City Generation, L.P. v. 
E.P.A., 696 F.3d 7 (D.C. Cir. 2012). The EME Homer City panel also 
ordered EPA to continue implementing CAIR in the interim. On March 29, 
2013, the United States asked the Supreme Court to review the EME Homer 
City decision. In the mean time, and unless the EME Homer City decision 
is reversed or otherwise modified, EPA intends to act in accordance 
with the panel opinion in EME Homer City.
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    \2\ See NOX SIP Call, 63 FR 57371 (October 27, 1998); 
CAIR, 70 FR 25172 (May 12, 2005); and Transport Rule or Cross-State 
Air Pollution Rule, 76 FR 48208 (August 8, 2011).
    \3\ CAIR addressed the 1997 annual and 24-hour PM2.5 
NAAQS, and the 1997 8-hour ozone NAAQS. It did not address the 2006 
24-hour PM2.5 NAAQS.
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    It is important to note that Montana was not among the states 
covered by CAIR and CSAPR and was outside of the modeling domain used 
in the analysis for those rules. However, as explained in section IV of 
this proposal, our methodology and analysis for evaluating Montana's 
compliance with 110(a)(2)(D)(i)(I) for the 2006 PM2.5 NAAQS 
is intended to be consistent with portions of the methodology in CSAPR 
that were not called into question in the D.C. Circuit's decision, in 
particular the methodology used to identify monitors in other states--
called ``receptors''--that are appropriate for assessing interstate 
transport.

C. EPA Guidance for SIP Submissions To Address Interstate Transport for 
the 2006 PM2.5 NAAQS

    On September 25, 2009, EPA issued a guidance memorandum that 
provides recommendations to states for making SIP submissions to meet 
the requirements of CAA section

[[Page 27885]]

110(a)(2)(D)(i) for the 2006 PM2.5 standards (``2006 
PM2.5 NAAQS Infrastructure Guidance'' or ``Guidance'').\4\ 
With respect to the requirement in section 110(a)(2)(D)(i)(I) to 
prohibit emissions that would contribute significantly to nonattainment 
of the NAAQS in any other state, the 2006 PM2.5 NAAQS 
Infrastructure Guidance essentially reiterated the recommendations for 
western states made by EPA in previous guidance addressing the 
110(a)(2)(D)(i) requirements for the 1997 8-hour Ozone and 1997 
PM2.5 NAAQS.\5\ The 2006 PM2.5 NAAQS 
Infrastructure Guidance advised states outside of the CAIR region to 
include in their section 110(a)(2)(D)(i)(I) SIP submissions an adequate 
technical analysis to support their conclusions regarding interstate 
pollution transport, e.g., information concerning emissions in the 
state, meteorological conditions in the state and in potentially 
impacted states, monitored ambient pollutant concentrations in the 
state and in potentially impacted states, distances to the nearest 
areas not attaining the NAAQS in other states, and air quality 
modeling.\6\ With respect to the requirement in section 
110(a)(2)(D)(i)(I) to prohibit emissions that would interfere with 
maintenance of the NAAQS by any other state, the Guidance stated that 
SIP submissions must address this independent and distinct requirement 
of the statute and provide technical information appropriate to support 
the State's conclusions, such as information concerning emissions in 
the state, meteorological conditions in the state and in potentially 
impacted states, monitored ambient concentrations in the state and in 
potentially impacted states, and air quality modeling.
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    \4\ See Memorandum from William T. Harnett entitled ``Guidance 
on SIP Elements Required Under Sections 110(a)(1) and (2) for the 
2006 24-Hour Fine Particle (PM2.5) National Ambient Air 
Quality Standards (NAAQS),'' September 25, 2009, available at http://www.epa.gov/ttn/caaa/t1/memoranda/20090925_harnett_pm25_sip_110a12.pdf.
    \5\ See Memorandum from William T. Harnett entitled ``Guidance 
for State Implementation Plan (SIP) Submission to Meet Current 
Outstanding Obligations Under Section 110(a)(2)(D)(i) for the 8-hour 
ozone and PM2.5 National Ambient Air Quality Standards,'' 
August 15, 2006, available at http://www.epa.gov/ttn/caaa/t1/memoranda/section110a2di_sip_guidance.pdf.
    \6\ The 2006 PM2.5 NAAQS Infrastructure Guidance 
stated that EPA was working on a new rule to replace CAIR that would 
address issues raised by the court in the North Carolina case and 
that would provide guidance to states in addressing the requirements 
related to interstate transport in CAA section 110(a)(2)(D)(i)(I) 
for the 2006 PM2.5 NAAQS. It also noted that states could 
not rely on the CAIR rule for section 110(a)(2)(D)(i)(I) submissions 
for the 2006 24-hour PM2.5 NAAQS because the CAIR rule 
did not address this NAAQS. See 2006 PM2.5 NAAQS 
Infrastructure Guidance at 3.
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    In assessing interstate transport of emissions from Montana, EPA 
continues to consider relevant the types of information that were 
suggested in the 2006 PM2.5 NAAQS Infrastructure Guidance. 
Such information may include, but is not limited to, the amount of 
emissions in the state relevant to the NAAQS in question, the 
meteorological conditions in the area, the distance from the state to 
the nearest monitors in other states that are appropriate receptors, or 
such other information as may be probative to consider whether sources 
in the state may contribute significantly to nonattainment or interfere 
with maintenance of the 2006 PM2.5 NAAQS in other states. 
Modeling can be relied on when acceptable modeling technical analyses 
are available, but EPA does not believe that modeling is necessarily 
required if other available information is sufficient to evaluate the 
presence or degree of interstate transport in a specific situation.

III. Montana's Submittal

    On February 10, 2010, the Montana Department of Environmental 
Quality (MDEQ) made a submission certifying that Montana's SIP is 
adequate to implement the 2006 PM2.5 NAAQS for all the 
``infrastructure'' requirements of CAA section 110(a)(2). This 
submission included a brief transport analysis to support the 
conclusion that Montana's SIP meets the requirements of CAA section 
110(a)(2)(D)(i)(I) for this NAAQS.\7\
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    \7\ MDEQ's certification letter, dated February 10, 2010 is 
included in the docket for this action.
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    Montana's PM2.5 transport analysis relies almost solely 
on EPA's decision not to model contribution from Montana to other 
states for the CAIR. We do not consider this adequate analysis, in 
large part because CAIR did not address the 2006 PM2.5 
NAAQS.\8\ Moreover, as Montana was outside the modeling domains used in 
developing CAIR and CSAPR, EPA did not model the impact of emissions 
from Montana in the modeling done for either rule. EPA's decision in 
CAIR and CSAPR to focus on transport among states in the eastern and 
central portions of the U.S. did not constitute a determination that 
SIPs for states outside the modeling domain (e.g. those in the Western 
U.S.) were necessarily adequate to address interstate transport for the 
1997 or 2006 PM2.5 NAAQS. As a result, western states such 
as Montana that were not included in the modeling domains for the CAIR 
and CSAPR rulemakings cannot rely on that modeling to demonstrate the 
adequacy of their transport SIPs. Such states, if they chose to submit 
transport SIPs for the 2006 PM2.5 NAAQS, must conduct a 
transport analysis that relies on relevant data and factors. MDEQ's 
submission contains no technical analysis of potential interstate 
transport or any other support for the State's conclusion that the 
existing Montana SIP satisfies the requirements of CAA section 
110(a)(2)(D)(i)(I) for the 2006 24-hour PM2.5 NAAQS. MDEQ's 
submission also failed to address how Montana's SIP is adequate to meet 
the requirements of CAA section 110(a)(2)(D)(ii).
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    \8\ CAIR addressed the 1997 PM2.5 and 1997 ozone 
NAAQS.
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IV. EPA's Evaluation

    To determine whether the CAA section 110(a)(2)(D)(i)(I) requirement 
is satisfied, EPA first determines whether a state's emissions 
contribute significantly to nonattainment or interfere with maintenance 
in downwind areas. If a state is determined not to have such 
contribution or interference, then section 110(a)(2)(D)(i)(I) does not 
require any changes to that state's SIP. If, however, the evaluation 
reveals that emissions from sources within the state do contribute 
significantly to nonattainment or interfere with maintenance in other 
states, then the state must adopt substantive provisions to eliminate 
those emissions. The state could achieve any required reductions 
through traditional command and control programs, or at its own 
election, through participation in a cap and trade program.
    Consistent with the first step of EPA's approach in the 1998 
NOX SIP call, the 2005 CAIR, and the 2011 CSAPR, EPA is 
evaluating impacts of emissions from Montana with respect to specific 
monitors identified as having nonattainment and/or maintenance 
problems, which we refer to as ``receptors.'' To evaluate these 
impacts, and in the absence of relevant modeling of Montana emissions, 
EPA is examining factors suggested by the 2006 Guidance such as 
monitoring data, topography, and meteorology. EPA notes that no single 
piece of information is by itself dispositive of the issue. Instead, 
the total weight of all the evidence taken together is used to evaluate 
significant contributions to nonattainment or interference with 
maintenance of the 2006 24-hour PM2.5 NAAQS in another 
state.
    As noted above, Montana's February 10, 2010 transport analysis 
relies on factors irrelevant to the 2006 PM2.5

[[Page 27886]]

NAAQS, and lacks any technical analysis to support the State's 
conclusion with respect to interstate transport. For these reasons, we 
propose to partially disapprove the State's submission. However, we 
also propose to partially approve the submission based on EPA's 
supplemental evaluation of relevant technical information, which 
supports a finding that emissions from Montana do not significantly 
contribute to nonattainment or interfere with maintenance of the 2006 
24-hour PM2.5 NAAQS in any other state and that the existing 
Montana SIP is, therefore, adequate to meet the requirements of CAA 
section 110(a)(2)(D)(i)(I) for the 2006 24-hour PM2.5 NAAQS.
    Our supplemental evaluation considers several factors, including 
identification of the monitors in other states that are appropriate 
``nonattainment receptors'' or ``maintenance receptors,'' consistent 
with EPA's approach in the CSAPR, and additional technical information 
to evaluate whether emissions from Montana contribute significantly to 
nonattainment or interfere with maintenance of the 2006 24-hour 
PM2.5 NAAQS at these receptors.
    Our Technical Support Document (TSD) contains a detailed evaluation 
and is available in the public docket for this rulemaking, which may be 
accessed online at http://www.regulations.gov, docket number EPA-R08-
OAR-2012-0347. Below, we provide a summary of our analysis.

A. Identification of Nonattainment and Maintenance Receptors

    EPA evaluated data from existing monitors over three overlapping 3-
year periods (i.e., 2006-2008, 2007-2009, and 2008-2010) to determine 
which areas were violating the 2006 PM2.5 NAAQS and which 
areas might have difficulty maintaining the standard. If a monitoring 
site measured a violation of the 2006 PM2.5 NAAQS during the 
most recent 3-year period (2008-2010), then this monitor location was 
evaluated for purposes of the significant contribution to nonattainment 
element of section 110(a)(2)(D)(i)(I). If, on the other hand, a 
monitoring site shows attainment of the 2006 PM2.5 NAAQS 
during the most recent 3-year period (2008-2010) but a violation in at 
least one of the previous two 3-year periods (2006-2008 or 2007-2009), 
then this monitor location was evaluated for purposes of the interfere 
with maintenance element of the statute.
    This approach is similar to that used in the modeling done during 
the development of CSAPR to identify the areas/receptors of concern 
when evaluating interstate transport. Nothing in the EME Homer City 
decision disturbs or undermines the validity of this approach to 
identifying receptors. However, as noted above, CSAPR did not model 
interstate transport of emissions from Montana to these receptors, so 
we consider other technical information to make our evaluation.

B. Evaluation of Significant Contribution to Nonattainment

    EPA reviewed technical information to evaluate the potential for 
Montana emissions to contribute significantly to nonattainment of the 
2006 PM2.5 NAAQS at specified monitoring sites in the 
Western U.S.\9\ EPA first identified as ``nonattainment receptors'' all 
monitoring sites in the western states that had recorded 
PM2.5 design values above the level of the 2006 24-hour 
PM2.5 NAAQS (35 [mu]g/m\3\) during the years 2008-2010.\10\ 
See Section III of our TSD for more a more detailed description of 
EPA's methodology for selection of nonattainment receptors.
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    \9\ EPA also considered potential PM2.5 transport 
from Montana to the nearest nonattainment and maintenance receptors 
located in the eastern, midwestern and southern states covered by 
CSAPR and believes it is reasonable to conclude that, given the 
significant distance from Montana to the nearest such receptor (in 
Wisconsin) and the relatively insignificant amount of emissions from 
Montana that could potentially be transported such a distance, 
emissions from Montana sources do not significantly contribute to 
nonattainment or interfere with maintenance of the 2006 24-hour 
PM2.5 NAAQS at this location. These same factors also 
support a finding that emissions from Montana sources neither 
contribute significantly to nonattainment nor interfere with 
maintenance of the 2006 24-hour PM2.5 NAAQS at any 
location further east. See TSD at Section I.B.3.
    \10\ Because CAIR did not cover states in the Western United 
States, these data are not significantly impacted by the remanded 
CAIR and thus could be considered in this analysis. In contrast, 
recent air quality data in the eastern, midwestern and southern 
states are significantly impacted by reductions associated with CAIR 
and because CSAPR was developed to replace CAIR, EPA could not 
consider reductions associated with the CAIR in the base case 
transport analysis for those states. See 76 FR at 48223-24.
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    Because geographic distance is a relevant factor in the assessment 
of potential pollution transport, EPA first reviewed information 
related to potential transport of PM2.5 pollution from 
Montana to the nonattainment receptors in states bordering Montana, 
both of which were in Idaho. As detailed in our TSD, the following 
factors support a finding that emissions from Montana do not 
significantly contribute to nonattainment of the 2006 24-hour 
PM2.5 NAAQS in Idaho: (1) Technical information, such as 
data from monitors in the vicinity of the Idaho nonattainment 
receptors, indicating that elevated PM2.5 levels are 
predominantly caused by emissions from local sources; (2) topographical 
considerations such as intervening mountain ranges; and 3) 
meteorological considerations such as prevailing winds. While none of 
these factors by itself would necessarily show non-contribution, when 
taken together in a weight-of-evidence assessment they are sufficient 
for EPA to determine that emissions from Montana do not significantly 
contribute to nonattainment at the Idaho receptors.
    EPA also evaluated potential PM2.5 transport to 
nonattainment receptors in the more distant western states of Oregon, 
Washington, Utah, Nevada, and California. The following factors support 
a finding that emissions from Montana do not significantly contribute 
to nonattainment of the 2006 24-hour PM2.5 NAAQS in any of 
these states: (1) The significant distance from Montana to the 
nonattainment receptors in these states; (2) technical information, 
such as data from nearby monitors, indicating that elevated 
PM2.5 levels at nonattainment receptors in these states are 
predominantly caused by emissions from local sources; and (3) the 
presence of intervening mountain ranges, which tend to impede pollution 
transport.
    Based on our evaluation, we propose to conclude that emissions of 
direct PM2.5 and PM2.5 precursors from sources in 
the State of Montana do not significantly contribute to nonattainment 
of the 2006 24-hour PM2.5 standards in any other state, that 
the existing SIP for the State of Montana is adequate to satisfy the 
``significant contribution'' requirements of CAA section 
110(a)(2)(D)(i)(I) with respect to the 2006 24-hour PM2.5 
standards, and that the State of Montana therefore does not need to 
adopt additional controls for purposes of implementing the 
``significant contribution'' requirements of 110(a)(2)(D)(i)(I) with 
respect to that NAAQS at this time.

C. Evaluation of Interference With Maintenance

    We also reviewed technical information to evaluate the potential 
for Montana emissions to interfere with maintenance of the 2006 24-hour 
PM2.5 standards at specified monitoring sites in the Western 
U.S. EPA first identified as ``maintenance receptors'' all monitoring 
sites in the western states that had recorded PM2.5 design 
values above the level of the 2006 24-hour PM2.5 NAAQS (35 
[mu]g/m\3\) during the 2006-2008 and/or 2007-2009 periods but below 
this standard during the 2008-2010 period. See section III of our

[[Page 27887]]

TSD for more information regarding EPA's methodology for selection of 
maintenance receptors. All of the maintenance receptors in the western 
states are located in California, Utah and Arizona. EPA therefore 
evaluated the potential for transport of Montana emissions to the 
maintenance receptors located in these states. As detailed in our TSD, 
the following factors support a finding that emissions from Montana do 
not interfere with maintenance of the 2006 24-hour PM2.5 
NAAQS in those states: (1) Technical information indicating that 
elevated PM2.5 levels at these maintenance receptors are 
predominantly caused by local emission sources; and (2) the significant 
distance between Montana and these maintenance receptors.
    Based on this evaluation, EPA proposes to conclude that emissions 
of direct PM2.5 and PM2.5 precursors from sources 
in the State of Montana do not interfere with maintenance of the 2006 
24-hour PM2.5 standards in any other state, that the 
existing SIP for the State of Montana is adequate to satisfy the 
``interfere with maintenance'' requirements of CAA section 
110(a)(2)(D)(i)(I), and that the State of Montana therefore does not 
need to adopt additional controls for purposes of implementing the 
``interfere with maintenance'' requirements of section 
110(a)(2)(D)(i)(I) with respect to that NAAQS at this time.

D. Evaluation of Montana's SIP With Regard to CAA Section 
110(a)(2)(D)(ii)

    As stated, MDEQ's February 10, 2010 submission did not address the 
requirements of CAA section 110(a)(2)(D)(ii), which requires that each 
SIP shall contain adequate provisions insuring compliance with 
applicable requirements of sections 126 and 115 (relating to interstate 
and international pollution abatement). Because the State did not 
address this element for the 2006 PM2.5 NAAQS, EPA proposes 
to partially disapprove this portion of Montana's submission. However, 
we also propose to partially approve the submission based on our 
evaluation which finds that Montana's existing SIP is sufficient to 
meet the requirements of 110(a)(2)(D)(ii).
    Section 126(a) requires notification to affected, nearby states of 
major proposed new (or modified) sources. Sections 126(b) and (c) 
pertain to petitions by affected states to the Administrator regarding 
sources violating the ``interstate transport'' provisions of section 
110(a)(2)(D)(i). Section 115 similarly pertains to international 
transport of air pollution.
    As required by 40 CFR 51.166(q)(2)(iv), Montana's SIP-approved PSD 
program requires notice to states whose lands may be affected by the 
emissions of sources subject to PSD.\11\ This suffices to meet the 
notice requirement of section 126(a).
---------------------------------------------------------------------------

    \11\ See Administrative Rule of Montana (``ARM'') 
17.8.826(2)(d).
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    Montana has no pending obligations under sections 126(c) or 115(b); 
therefore, its SIP currently meets the requirements of those sections. 
In summary, the SIP meets the requirements of 110(a)(2)(D)(ii) for the 
2006 PM2.5 NAAQS.

V. Proposed Action

    EPA is proposing to partially approve and partially disapprove the 
110(a)(2)(D)(i)(I) and 110(a)(2)(D)(ii) portions of Montana's February 
10, 2010 submission. We propose to partially disapprove the 
110(a)(2)(D)(i)(I) portion of the submission because it relies on 
irrelevant factors and lacks any technical analysis to support the 
State's conclusion with respect to interstate transport. However, we 
also propose to partially approve this portion of the submission based 
on EPA's supplemental evaluation of relevant technical information, 
which supports a finding that emissions from Montana do not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2006 24-hour PM2.5 NAAQS in any other state and that 
the existing Montana SIP is, therefore, adequate to meet the 
requirements of CAA section 110(a)(2)(D)(i)(I) for the 2006 24-hour 
PM2.5 NAAQS. We propose to conclude that any FIP obligation 
resulting from finalization of the partial disapproval would be 
satisfied by our determination that there is no deficiency in the SIP 
to correct. Finalization of this proposed disapproval also would not 
require any further action on Montana's part given EPA's conclusion 
that the SIP is adequate to meet the requirements of CAA section 
110(a)(2)(D)(i)(I) for the 2006 24-hour PM2.5 NAAQS.
    Similarly, EPA is proposing to partially disapprove the 
110(a)(2)(D)(ii) portion of Montana's submission because it fails to 
address or discuss this CAA requirement. However, we propose to 
partially approve this portion of the submission based on the 
conclusion that the State's existing SIP is adequate to meet the 
requirements of CAA section 110(a)(2)(D)(ii) for the 2006 24-hour 
PM2.5 NAAQS. For similar reasons, the partial disapproval of 
the submission for the 110(a)(2)(D)(ii) requirement does not require 
any further action from Montana or create any additional FIP obligation 
for EPA.

VI. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
federal regulations (42 U.S.C. 7410(k), 40 CFR 52.02(a)). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
proposed action merely approves some state law as meeting federal 
requirements and disapproves other state law because it does not meet 
federal requirements; this proposed action does not impose additional 
requirements beyond those imposed by state law. For that reason, this 
proposed action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Public Law 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and,
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, this rule does not have Tribal implications as specified 
by Executive Order 13175 (65 FR 67249, November 9, 2000), because the 
SIP is

[[Page 27888]]

not approved to apply in Indian country located in the state, and EPA 
notes that it will not impose substantial direct costs on Tribal 
governments or preempt Tribal law.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Nitrogen dioxide, Ozone, 
Particulate matter, Reporting and recordkeeping requirements, Volatile 
Organic Compounds.

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

    Dated: May 2, 2013.
Howard M. Cantor,
Acting Regional Administrator, Region 8.
[FR Doc. 2013-11292 Filed 5-10-13; 8:45 am]
BILLING CODE 6560-50-P