Document ID: EPA-R08-OAR-2021-0808-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Montana; Whitefish PM10 Nonattainment Area Limited Maintenance Plan and Redesignation Request
Posted Date: 2022-03-08T05:00Z

[Federal Register Volume 87, Number 45 (Tuesday, March 8, 2022)]
[Proposed Rules]
[Pages 12912-12919]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-04758]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R08-OAR-2021-0808; FRL-9595-01-R8]

Air Plan Approval; Montana; Whitefish PM10 Nonattainment Area 
Limited Maintenance Plan and Redesignation Request

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
fully approve the Limited Maintenance Plan (LMP) submitted by the State 
of Montana to EPA on August 6, 2021, for the Whitefish Moderate 
nonattainment area (NAA) for particulate matter with an aerodynamic 
diameter less than or equal to a nominal 10 micrometers 
(PM10) and concurrently redesignate the NAA to attainment 
for the 24-hour PM10 National Ambient Air Quality Standard 
(NAAQS). In order to approve the LMP and redesignation, EPA is 
proposing to determine that the Whitefish NAA has attained the 1987 24-
hour PM10 NAAQS of 150 [micro]g/m\3\. This determination is 
based upon monitored air quality data for the PM10 NAAQS 
during the years 2015-2020. EPA is taking this action pursuant to the 
Clean Air Act (CAA).

DATES: Written comments must be received on or before April 7, 2022.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2021-0808 to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
www.regulations.gov. The EPA may publish any comment received to its 
public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. The EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.
    Docket: All documents in the docket are listed in the 
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 electronically in 
www.regulations.gov. To reduce the risk of COVID-19 transmission, for 
this action we do not

[[Page 12913]]

plan to offer hard copy review of the docket. Please email or call the 
person listed in the FOR FURTHER INFORMATION CONTACT section if you 
need to make alternative arrangements for access to the docket.

FOR FURTHER INFORMATION CONTACT: Kate Gregory, Air and Radiation 
Division, U.S. Environmental Protection Agency (EPA), Region 8, Mail 
Code 8P-ARD-QP, 1595 Wynkoop Street, Denver, Colorado 80202-1129, 
telephone number: (303) 312-6175, email address: [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,'' 
``us,'' or ``our'' is used, we mean the EPA.

I. Background

Description of the Whitefish NAA

    The Whitefish NAA is in Flathead County and is in the northwest 
corner of the Flathead Valley, with the Whitefish range of mountains on 
the north and east sides of the small, rural, city of Whitefish and the 
Salish mountains to the west. The EPA promulgated the PM10 
National NAAQS on July 1, 1987 (52 FR 24634). The Whitefish NAA was 
originally designated as a Group III area on July 1, 1987 (52 FR 
24634), meaning, at that time, there was a strong likelihood the 
Whitefish NAA would attain the PM10 NAAQS and, therefore, 
needed only adjustments to their preconstruction permit review program 
and monitoring network. However, on July 16, 1992, the Administrator of 
EPA, Region 8 notified the Governor of Montana that EPA believed that 
the area around Whitefish should be redesignated as nonattainment for 
PM10 and subsequently the Whitefish NAA was classified as 
Moderate for the 1987 24-hour PM10 NAAQS on November 18, 
1993 (58 FR 53886).\1\ Within 18 months of this Moderate designation, 
by May 18, 1995, Montana was required to submit to EPA a Moderate NAA 
State Implementation Plan (SIP) for the Whitefish NAA containing, among 
other requirements, provisions to assure that reasonably available 
control measures (RACM), including reasonably available control 
technologies (RACT), are implemented and a demonstration as to whether 
it was practicable to attain the PM10 NAAQS by December 31, 
2000 (57 FR 13498 (April 16, 1992).\2\
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    \1\ See p. 64 of document titled FR-1993-10-19.pdf in docket for 
58 FR 53886.
    \2\ See also 57 FR 18070 (April 28, 1992) and 66 FR 55102 
(November 1, 2001).
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    The State of Montana submitted an initial PM10 SIP to 
EPA on June 26, 1997, and a subsequent submission on June 13, 2000. EPA 
approved both the June 26, 1997 and the June 13, 2000 PM10 
SIP submissions for the Whitefish initial control plan on April 24, 
2008 (73 FR 22057). The State of Montana's SIP for the Whitefish 
Moderate NAA included but was not limited to a comprehensive emissions 
inventory, RACM (implemented by November 18, 1997), a demonstration 
that attainment of the PM10 NAAQS would be achieved in 
Whitefish by December 31, 2000; Reasonable Further Progress (RFP) 
requirements and control measures that satisfy the contingency measures 
requirement of section 172(c)(9) of the CAA. The EPA fully approved the 
Whitefish NAA PM10 attainment plan on April 24, 2008 (73 FR 
22057).

II. Requirements for Redesignation

A. CAA Requirements for Redesignation of NAAs

    NAAs can be redesignated to attainment after the area has measured 
air quality data showing it has attained the NAAQS and when certain 
planning requirements are met. Section 107(d)(3)(E) of the CAA, and the 
General Preamble to Title I provide the criteria for redesignation. See 
57 FR 13498 (April 16, 1992). These criteria are further clarified in a 
policy and guidance memorandum from John Calcagni, Director, Air 
Quality Management Division, EPA Office of Air Quality Planning and 
Standards dated September 4, 1992, ``Procedures for Processing Requests 
to Redesignate Areas to Attainment.'' \3\ The criteria for 
redesignation are:
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    \3\ The ``Procedures for Processing Requests to Redesignate 
Areas to Attainment'' (Calcagni memo) outlines the criteria for 
redesignation (see docket for memo).
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    (1) The Administrator has determined that the area has attained the 
applicable NAAQS;
    (2) The Administrator has fully approved the applicable SIP for the 
area under section 110(k) of the CAA;
    (3) The state containing the area has met all requirements 
applicable to the area under section 110 and part D of the CAA;
    (4) The Administrator has determined that the improvement in air 
quality is due to permanent and enforceable reductions in emissions; 
and
    (5) The Administrator has fully approved a maintenance plan for the 
area as meeting the requirements of section 175A of the CAA.

B. The LMP Option for PM10 NAAs

    On August 9, 2001, the EPA issued guidance on streamlined 
maintenance plan provisions for certain moderate PM10 NAAs 
seeking redesignation to attainment (Memo from Lydia Wegman, Director, 
Air Quality Standards and Strategies Division, entitled ``Limited 
Maintenance Plan Option for Moderate PM10 Nonattainment 
Areas,'' (hereafter the LMP Option memo)).\4\ The LMP Option memo 
contains a statistical demonstration to show that areas meeting certain 
air quality criteria will, with a high degree of probability, maintain 
the standard 10 years into the future. Thus, the EPA has already 
provided the maintenance demonstration for areas meeting the criteria 
outlined in the LMP Option memo. It follows that future year emission 
inventories for these areas, and some of the standard analyses to 
determine transportation conformity with the SIP are no longer 
necessary.
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    \4\ The ``Limited Maintenance Plan Option for Moderate 
PM10 Nonattainment Areas'' outlines the criteria for 
development of a PM10 limited maintenance plan (see 
docket for memo).
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    To qualify for the LMP Option, the area should have attained the 
1987 24-hour PM10 NAAQS, based upon the most recent 5 years 
of air quality data at all monitors in the area, and the 24-hour design 
concentration should be at or below the ``Critical Design Value'' 
(CDV). The CDV is a calculated design concentration that indicates that 
the area has a low probability (1 in 10) of exceeding the NAAQS in the 
future. For the purposes of qualifying for the LMP option, a 
presumptive CDV of 98 [micro]g/m\3\ is most often employed, but an area 
may elect to use a site-specific CDV should the average design 
concentration (ADC) be above 98 [micro]g/m\3\, while demonstrating that 
the area has a low probability of exceeding the NAAQS in the future. 
The annual PM10 standard was effectively revoked on December 
18, 2006 (71 FR 61143), and as such will not be discussed as a 
requirement for qualifying for the LMP option. In addition, the area 
should expect only limited growth in on-road motor vehicle 
PM10 emissions (including fugitive dust) and should have 
passed a motor vehicle regional emissions analysis test. The LMP Option 
memo also identifies core provisions that must be included in the LMP. 
These provisions include an attainment year emissions inventory, 
assurance of continued operation of an EPA-approved air quality 
monitoring network, and contingency provisions.

[[Page 12914]]

III. Review of Montana's Submittal Addressing the Requirements for 
Redesignation and Limited Maintenance Plan

A. Has the Whitefish NAA attained the applicable NAAQS?

    States must demonstrate that an area has attained the 24-hour 
PM10 NAAQS through analysis of ambient air quality data from 
an ambient air monitoring network representing peak PM10 
concentrations. The data should be stored in the EPA Air Quality System 
(AQS) database. The request for redesignation of the Whitefish 
PM10 NAA submitted by the State of Montana presented data 
and analyses to demonstrate that the area attained the PM10 
standard using 2015-2019 data. The redesignation request excluded two 
values in 2018 that it believed would be removed from the dataset prior 
to this action, but those values have not been concurred on as 
exceptional events and were included in the EPA's data and analyses 
presented in this action. In addition to reviewing the 2015-2019 data 
the EPA included 2020 PM10 data in this action (as it is 
currently the most recent year of certified data present in AQS) to 
confirm that the area is still attaining the 24-hour PM10 
NAAQS. Additionally, preliminary 2021 data indicates the area continues 
to attain.
    Today, EPA is proposing to determine that the Whitefish NAA has 
attained the PM10 NAAQS based on monitoring data from 
calendar years 2015-2020. The 24-hour standard is attained when the 
expected number of 24-hour average concentrations above 150 [micro]g/
m\3\ (averaged over a 3-year period) is less than or equal to one. See 
40 CFR 50.6(a). A minimum of three complete and consecutive years of 
air quality data are generally necessary to show attainment of the 
standard. See 40 CFR part 50, appendix K. A complete year of air 
quality data, as referred to in 40 CFR part 50, appendix K, is 
comprised of all four calendar quarters with each quarter containing 
data from at least 75% of the scheduled sampling days.
    The Whitefish NAA has one State and Local Air Monitoring Station 
(SLAMS) PM10 monitor, Whitefish Dead End (AQS ID 30-029-
0009), operated by the Montana Department of Environmental Quality 
(MDEQ). Table 1 summarizes the PM10 data collected from 
2015-2020 for the Whitefish NAA.\5\ The EPA deems the data collected 
from these monitors valid, and the data have been submitted and 
certified by the MDEQ to be included in AQS.
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    \5\ While the submission from the State for this action includes 
2015-2019 monitoring data, EPA provided 2020 monitoring data in this 
action in order to provide an analysis of PM10 
concentrations in the Whitefish, NAA area using the most current 
monitoring data available.

 Table 1--Summary of Maximum 24-Hour PM10 Concentrations ([micro]g/m\3\), Design Concentrations ([micro]g/m\3\),
                                and Number of Exceedances for Whitefish 2015-2020
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                                                                                                    Number of
                                                                                                   exceedances
                                                                                                    excluding
                            Year                                 Maximum            Design          regionally
                                                              concentration   concentration \6\     concurred
                                                                                                   exceptional
                                                                                                    events \7\
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2015.......................................................              135                122                0
2016.......................................................              105                122                0
2017.......................................................              153                131                0
2018.......................................................              188                135                1
2019.......................................................               86                135                0
2020.......................................................              145                136                0
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    The CAA allows for the exclusion of air quality monitoring data 
from design value calculations when there are exceedances caused by 
exceptional events, including for expected number exceedances for 
PM10 averaged over a 3-year period, that meet the criteria 
for an exceptional event identified in the EPA's implementing 
regulations, the Exceptional Events Rule at 40 CFR 50.1, 50.14, and 
51.930. For the purposes of this proposed action, on November 23, 2021, 
the State of Montana submitted exceptional event demonstrations to 
request exclusion of data impacted by wildfires. The EPA evaluated the 
State of Montana's exceptional event demonstrations for the flagged 
values of the 24-hour PM10 listed in Table 3 below in the 
Whitefish Moderate NAA, with respect to the requirements of EPA's 
Exceptional Events Rule (40 CFR 50.1, 50.14, and 50.930).
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    \6\ The design concentrations are calculated using three years 
of data and the ``Table Look-up'' method described in the 
``PM10 SIP Development Guideline'', EPA-450/2-86-001, 
June 1987.
    \7\ Exceedances in 2017 and 2020 have been flagged and concurred 
on as exceptional events. Additional information on 2017 data can be 
found in Appendix A, p. a-1, of the submission by the state in the 
docket of this action and additional information on 2020 data can be 
found in the docket for this action, document titled: Montana 2020 
PM10 Letter.
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    On January 25, 2022, EPA concurred with the State of Montana's 
requests to exclude event-influenced data listed in Table 3 finding 
that the State of Montana's demonstration met the Exceptional Event 
Rule criteria. As such, the event-influenced data have been removed 
from the data set used for regulatory purposes. For this proposed 
action, EPA relies on the PM10 concentrations reported at 
the Whitefish monitoring site which showed only one exceedance from 
2015-2020 when exceptional events are excluded. Therefore, the expected 
number of days with 24-hour average concentrations above 150 [micro]g/
m\3\ averaged over a 3-year period is less than one, and as such, the 
EPA proposes to determine that the Whitefish NAA has attained the 
standard for the 24-hour PM10 NAAQS.\8\
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    \8\ Please see section III(F) of this action for further 
discussion and description of exceptional events in the Whitefish 
NAA during the 2015-2020 time period.
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    Additionally, the EPA concurred on the State of Montana's request 
to exclude PM10 data listed in Table 3 in regulatory 
decisions. For further information, refer to the State of Montana's 
Exceptional Event demonstration packages and the EPA's concurrence and 
analyses located in the docket for this proposed action.

B. Does the Whitefish NAA have a fully approved SIP under CAA section 
110(k)?

    In order to qualify for redesignation, the SIP for the area must be 
fully approved under CAA section 110(k) and must satisfy all 
requirements that apply

[[Page 12915]]

to the area. Section 189 of the CAA contains requirements and 
milestones for all initial Moderate NAA SIPs including: (1) Provisions 
to assure that RACM (including such reductions in emissions from 
existing sources in the area as may be obtained through the adoption, 
at a minimum, of RACT shall be implemented no later than December 10, 
1993; (2) A demonstration (including air quality modeling) that the 
plan will provide for attainment as expeditiously as practicable by no 
later than December 31, 1994, or, where the state is seeking an 
extension of the attainment date under section 188(e), a demonstration 
that attainment by December 31, 1994, is impracticable and that the 
plan provides for attainment by the most expeditious alternative date 
practicable (CAA sections 189(a)(1)(A)); (3) Quantitative milestones 
which are to be achieved every 3 years and which demonstrate RFP toward 
attainment by December 31, 1994, (CAA sections 172(c)(2) and 189(c)); 
and (4) Contingency measures to be implemented if the area fails to 
make RFP or attain by its attainment deadline. These contingency 
measures are to take effect without further action by the state or the 
EPA (CAA section 172(c)(9)).
    The EPA fully approved the Whitefish NAA PM10 attainment 
plan on April 24, 2008 (73 FR 22057). The Whitefish plan included RACM, 
an attainment demonstration, emissions inventory, quantitative 
milestones, and control and contingency measure requirements. As such, 
the area has a fully approved NAA SIPs under section 110(k) of the CAA.

C. Has the state met all applicable requirements under section 110 and 
part D of the CAA?

    Section 107(d)(3)(E) of the CAA requires that a state containing a 
NAA must meet all applicable requirements under section 110 and Part D 
of the CAA for an area to be redesignated to attainment. The EPA 
interprets this to mean that the state must meet all requirements that 
applied to the area prior to, and at the time of, the submission of a 
complete redesignation request. The following is a summary of how 
Montana meets these requirements.
1. CAA Section 110 Requirements
    Section 110(a)(2) of the CAA contains general requirements for 
SIPs. These requirements include, but are not limited to, submittal of 
a SIP that has been adopted by a state after reasonable notice and 
public hearing, provisions for establishment and operation of 
appropriate apparatus, methods, systems and procedures necessary to 
monitor ambient air quality, implementation of a permit program, 
provisions for Part C--Prevention of Significant Deterioration (PSD) 
and Part D--New Source Review (NSR) permit programs, criteria for 
stationary source emission control measures, monitoring and reporting, 
provisions for modeling and provisions for public and local agency 
participation. See the General Preamble for further explanation of 
these requirements. See 57 FR 13498 (April 16, 1992).
    For purposes of redesignation, the EPA's review of the Montana SIP 
shows that the State has satisfied all requirements under section 
110(a)(2) of the CAA. Further, in 40 CFR 52.1372, the EPA has approved 
Montana's plan for the attainment and maintenance of the national 
standards under section 110.
2. Part D Requirements
    Part D contains general requirements applicable to all areas 
designated nonattainment. The general requirements are followed by a 
series of subparts specific to each pollutant. All PM10 NAAs 
must meet the general provisions of Subpart 1 and the specific 
PM10 provisions in Subpart 4, ``Additional Provisions for 
Particulate Matter Nonattainment Areas.'' The following paragraphs 
discuss these requirements as they apply to the Whitefish NAA.
3. Subpart 1, Section 172(c)
    Subpart 1, section 172(c) contains general requirements for NAA 
plans. A thorough discussion of these requirements may be found in the 
General Preamble. See 57 FR 13538 (April 16, 1992). CAA section 
172(c)(2) requires nonattainment plans to provide for RFP. Section 
171(1) of the CAA defines RFP as ``such annual incremental reductions 
in emissions of the relevant air pollutant as are required by this part 
(part D of title I) or may reasonably be required by the Administrator 
for the purpose of ensuring attainment of the applicable national 
ambient air quality standard by the applicable date.'' Since EPA is 
proposing to determine that the Whitefish NAA is in attainment of the 
PM10 NAAQS, we believe that no further showing of RFP or 
quantitative milestones is necessary.
4. Section 172(c)(3)--Emissions Inventory Section
    Section 172(c)(3) of the CAA requires a comprehensive, accurate, 
current inventory of actual emissions from all sources in the Whitefish 
PM10 NAA. Montana included an emissions inventory for the 
calendar year 2017 with the August 6, 2021 submittal of the LMP for the 
NAA. The LMP Option memo states that an attainment inventory should 
represent emissions during the same 5-year period associated with the 
air quality data used to determine that the area meets the 
applicability requirements of the LMP option. The Whitefish LMP 
includes an emission inventory from 2017, representative of the 2015-
2019 5-year period which served as the 5-year period relied upon in the 
LMPs as meeting the air quality data requirements of the LMP option 
memo.\9\
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    \9\ The emissions inventory included in the Whitefish MT 
submission is the 2017 National Emissions Inventory (NEI). The NEI 
is a composite of data from many different sources, with PM data 
coming primarily from EPA models as well as from state, tribal, and 
local air quality management agencies. Different data sources use 
different data collection methods, and many of the emissions data 
are based on estimates rather than actual measurements. The EPA 
considers the 2017 NEI representative of the period from 2015-2019 
because MT provided comparable vehicle miles traveled (VMT) data in 
their submission. See Whitefish, MT Submission, Appendix C, Montana 
Department of Transportation Future VMT Projections, p.C-1 in 
docket.
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5. Section 172(c)(5)--NSR
    The 1990 CAA Amendments contained revisions to the NSR program 
requirements for the construction and operation of new and modified 
major stationary sources located in NAAs. The CAA requires states to 
amend their SIPs to reflect these revisions but does not require 
submittal of this element along with the other SIP elements. The CAA 
established June 30, 1992, as the submittal date for the revised NSR 
programs (section 189 of the CAA).
    Montana has a fully approved nonattainment NSR program, approved on 
September 18, 1995 (60 FR 36715). Montana also has a fully approved PSD 
program, approved on September 18, 1995 (60 FR 36715). Upon the 
effective date of redesignation of an area from nonattainment to 
attainment, the requirements of the Part D NSR program will be replaced 
by the PSD program and the maintenance area NSR program.
6. Section 172(c)(7)--Compliance With CAA Section 110(a)(2): Air 
Quality Monitoring Requirements
    Once an area is redesignated, the state must continue to operate an 
appropriate air monitoring network in accordance with 40 CFR part 58 to 
verify attainment status of the area. The State of Montana operates one 
PM10 SLAMS in each of the NAAs. The Whitefish monitoring 
site meets EPA SLAMS network design and siting requirements set forth 
at 40 CFR part 58, appendices D and E. In section 3.5 of the LMP that 
we are

[[Page 12916]]

proposing to approve, the State commits to continued operation of the 
monitoring network.
7. Section 172(c)(9)--Contingency Measures
    The CAA requires that contingency measures take effect if the area 
fails to meet RFP requirements or fails to attain the NAAQS by the 
applicable attainment date. Since the Whitefish NAA has attained the 
1987 24-hour PM10 NAAQS, contingency measures are no longer 
required under section 172(c)(9) of the CAA. However, contingency 
provisions are required for maintenance plans under section 175(a)(d). 
We describe the contingency provisions Montana provided in the LMP 
section below.
8. Part D, Subpart 4
    Part D subpart 4, section 189(a), (c) and (e) requirements apply to 
any Moderate NAA before the area can be redesignated to attainment. The 
requirements which were applicable prior to the submission of the 
request to redesignate the area must be fully approved into the SIP 
before redesignating the area to attainment. These requirements 
include: (a) Provisions to assure that RACM was implemented by December 
10, 1993; (b) Either a demonstration that the plan provided for 
attainment as expeditiously as practicable but not later than December 
31, 1994, or a demonstration that attainment by that date was 
impracticable; (c) Quantitative milestones which were achieved every 3 
years and which demonstrate RFP toward attainment by December 31, 1994; 
and (d) Provisions to assure that the control requirements applicable 
to major stationary sources of PM10 also apply to major 
stationary sources of PM10 precursors except where the 
Administrator determined that such sources do not contribute 
significantly to PM10 levels which exceed the NAAQS in the 
area. These provisions were fully approved into the SIP upon the EPA's 
approval of the PM10 Moderate area plan for the Whitefish 
NAA on March 22, 1995 (60 FR 15056).

D. Has the state demonstrated that the air quality improvement is due 
to permanent and enforceable reductions?

    A state must be able to reasonably attribute the improvement in air 
quality to permanent and enforceable emission reductions. In making 
this showing, a state must demonstrate that air quality improvements 
are the result of actual enforceable emission reductions. This showing 
should consider emission rates, production capacities, and other 
related information. The analysis should assume that sources are 
operating at permitted levels (or historic peak levels) unless evidence 
is presented that such an assumption is unrealistic. Permanent and 
enforceable control measures in the Whitefish NAA SIP includes RACM. 
Emission sources in the NAA have been implementing RACM for at least 10 
years.
    Areas that qualify for the LMP will meet the NAAQS, even under 
worst case meteorological conditions. Under the LMP option, the 
maintenance demonstration is presumed to be satisfied if an area meets 
the qualifying criteria. Thus, by qualifying for the LMP, Montana has 
demonstrated that the air quality improvements in the Whitefish NAA is 
the result of permanent emission reductions and not a result of either 
economic trends or meteorology. A description of the LMP qualifying 
criteria and how the Whitefish area meets these criteria is provided in 
the following section.
    Permanent and enforceable emission reductions in the Whitefish NAA 
have reduced emissions since the 1993 baseline year. The primary 
controls incorporated into the SIP included reducing fugitive dust 
emissions from roads, parking lots, construction and demolition 
projects, and barren ground as well as stipulations on industrial 
emissions. Additionally, the approved control plan satisfied the 
requirements for RACM of area sources. Based on the 2017 national 
emissions inventory, PM10 emissions in all source areas are 
below the levels approved in the original control plan.\10\
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    \10\ See Whitefish, MT submission in docket, Table 2.4--
Whitefish, MT--PM10 Emission Summary, p. 2-5.
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E. Does the area have a fully approved maintenance plan pursuant to 
section 175A of the CAA?

    In this action, we are proposing to approve the LMP for the 
Whitefish NAA in accordance with the principles outlined in the LMP 
Option.

F. Has the state demonstrated that the Whitefish NAA qualifies for the 
LMP Option?

    The LMP Option memo outlines the requirements for an area to 
qualify for the LMP Option. First, the area should be attaining the 
NAAQS. As stated above in section III.A., the EPA has determined that 
the Whitefish NAA is attaining the PM10 NAAQS.
    Second, the ADC for the past 5 years of monitoring data (2015-2019) 
must be at or below the CDV and the area must meet the motor vehicle 
regional emissions analysis test in attachment B of the LMP Option 
memo. As noted in section II.B., the CDV is a margin of safety value 
and is the value at which an area has been determined to have a 1 in 10 
probability of exceeding the NAAQS. The LMP Option memo provides two 
methods for review of monitoring data for the purpose of qualifying for 
the LMP option. The first method is a comparison of a site's ADC with 
the CDV of 98 [micro]g/m\3\ for the 24-hour PM10 NAAQS. A 
second method that applies to the 24-hour PM10 NAAQS is the 
calculation of a site-specific CDV and a comparison of the site-
specific CDV with the ADC for the past 5 years of monitoring data. 
Table 2 below outlines the design concentrations for the years 2015-
2020 and presents the ADC.
    Table 3 summarizes the wildfire related events that were excluded 
from the calculated design concentrations in Table 2. Table 3 includes 
all regionally concurred exceptional events, as well as values between 
98 [micro]g/m\3\ and 155 [micro]g/m\3\, which were treated in a manner 
analogous to exceedance data under the Exceptional Events Rule for the 
purpose of determining the LMP option eligibility. The values between 
98 [micro]g/m\3\ and 155 [micro]g/m\3\ remain in the AQS database for 
use in calculating design concentration for every purpose besides 
determining LMP eligibility.\11\ The Exceptional Events Rule can be 
found in 40 CFR 50.14 and 40 CFR 51.930, and outlines the requirements 
for the treatment of monitored air quality data that has been heavily 
influenced by an exceptional event. 40 CFR 50.1(j) defines an 
exceptional event as an event which affects air quality, is not 
reasonably controllable or preventable, is an event caused by human 
activity that is unlikely to recur at a particular location or a 
natural event and is determined by the Administrator in accordance with 
40 CFR 50.14 to be an exceptional event. Exceptional events do not 
include stagnation of air masses or meteorological inversions, 
meteorological events involving high temperatures or lack of 
precipitation, or air pollution relating to source noncompliance. 40 
CFR 50.14(b) states that the EPA shall exclude data from use in 
determinations of exceedances and NAAQS violations where a state 
demonstrates to the EPA's satisfaction that an exceptional event caused 
a specific air pollution concentration in excess of one or more NAAQS 
at a

[[Page 12917]]

particular air quality monitoring location and otherwise satisfies the 
requirements of section 50.14. Table 3 below includes some values 
between 98 [micro]g/m\3\ and 155 [micro]g/m\3\ that were excluded for 
the sole purpose of determining PM10 LMP eligibility in 
accordance with the LMP guidance.\12\ Supporting documentation of EPA's 
concurrence with the wildfire related events can be found in the 
docket.\13\
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    \11\ Update on Application of the Exceptional Events Rule to the 
PM10 Limited Maintenance Plan Option, US EPA, William T. 
Harnett, Director, Air Quality Policy Division, OAQPS, May 7, 2009.
    \12\ See Update on Application of the Exceptional Events Rule to 
the PM10 Limited Maintenance Plan Option, US EPA, William 
T. Harnett, Director, Air Quality Policy Division, OAQPS, May 7, 
2009 and Additional Methods, Determinations, and Analyses to Modify 
Air Quality Data Beyond Exceptional Events, US EPA, Richard Wayland, 
Director, Air Quality Assessment Division and Anna Marie Wood, 
Director, Air Quality Policy Division, April 4, 2019 memos in 
docket.
    \13\ February 8, 2019 letter to MDEQ, Re: Exceptional Events 
Requests Regarding Exceedances of the 24-hour PM10 NAAQS 
and the LMP Eligibility Threshold at Montana Monitoring Sites with 
PM10 Nonattainment Areas; and November 1, 2018 letter to 
MDEQ, Re: Request for EPA concurrence on exceptional event claims 
for fine (PM2.5) and coarse (PM10) particulate 
matter data impacted by wildfires in 2015 and 2016. See Whitefish, 
MT submission in docket.

 Table 2--Summary of 24-Hour PM10 Design Concentrations ([micro]g/m\3\)
                              for Whitefish
------------------------------------------------------------------------
 Based on data from Whitefish Dead End, AQS  Identification Number (30-
                                029-0009)
-------------------------------------------------------------------------
                                                              Design
               Design concentration years                 concentration
                                                         ([micro]g/m\3\)
------------------------------------------------------------------------
2015-2017..............................................              118
2016-2018..............................................               98
2017-2019..............................................               91
2018-2020..............................................              103
------------------------------------------------------------------------
Average Design Concentration (Of Most Recent 3 Design Concentrations) 97
  [micro]g/m\3\.

 Table 3--Whitefish 24-Hour PM10 Events Excluded From the 2015-2020 Data
             for the Purpose of Determining LMP Eligibility
------------------------------------------------------------------------
  Based on data from Whitefish Dead End Site, AQS Identification Number
                              (30-029-0009)
-------------------------------------------------------------------------
                                                          24-Hour  value
                          Date                           ([micro]g/m\3\)
------------------------------------------------------------------------
8/20/2015..............................................              128
8/21/2015..............................................              131
8/24/2015..............................................              122
8/25/2015..............................................              106
8/27/2015..............................................              118
8/28/2015..............................................              110
8/29/2015..............................................              104
9/4/2017...............................................              153
9/5/2017...............................................              122
9/6/2017...............................................              143
9/7/2017...............................................              212
9/8/2017...............................................              215
9/9/2017...............................................              130
9/13/2020..............................................              145
9/14/2020..............................................              172
9/15/2020..............................................              139
9/18/2020..............................................              100
------------------------------------------------------------------------
Values between 98 [micro]g/m\3\ and 155 [micro]g/m\3\ were excluded by
  EPA solely for the purpose of determining limited maintenance plan
  (LMP) eligibility in accordance with LMP guidance. The values remain
  in AQS and are still used for all other purposes (including
  calculating the estimated exceedances and official design
  concentrations).

    The ADC for the 24-hour PM10 NAAQS for Whitefish, based 
on data from the SLAMS monitor for the years 2016-2020 is 97 [micro]g/
m\3\. This value falls just below the presumptive 24-hour CDV of 98 
[micro]g/m\3\ but leaves very little room for any growth under the 
motor vehicle regional emissions analysis test. Therefore, an area-
specific CDV is necessary. Using design concentrations from 2009 
through 2020 and the methodology outlined in the LMP memo, the EPA 
calculates the area-specific CDV at 130 [micro]g/m\3\. This area-
specific CDV was used for the remaining calculations in this action.
    In addition to having an ADC that is at the presumptive or area-
specific CDV, and in order to qualify for the LMP, the area must meet 
the motor vehicle regional emissions analysis test in attachment B of 
the LMP Option memo. Using the methodology outlined in the memo, the 
data presented in the State's submission in section 3.2 and based on 
monitoring data for the period 2016-2020, the EPA has determined that 
the Whitefish NAA has a projected design concentration of 119 [micro]g/
m\3\ after 10 years, attributable to motor vehicle emission growth. 
This value is below the area-specific 24-hour CDV of 130 [micro]g/m\3\ 
and therefore passes the motor vehicle regional emissions analysis 
test. For the detailed calculations used to determine how the Whitefish 
NAA passed the motor vehicle regional analysis test, see the supporting 
documents in the docket.\14\
---------------------------------------------------------------------------

    \14\ See memo to file in docket dated January 10, 2022 titled 
``Memo to File--Whitefish, MT Motor Vehicle Regional Emissions 
Analysis.''
---------------------------------------------------------------------------

    Using the most recent 5 years of data (2016-2020), the analyses in 
this section of the action demonstrates that the Whitefish NAA has 
attained the 24-hour NAAQS for PM10, that the 24-hour ADC 
for the area is less that the area-specific 24-hour PM10 CDV 
of 130 [micro]g/m\3\, and the area has met the regional vehicle 
emissions analysis test. Thus, the Whitefish NAA qualifies for the LMP 
Option described in the LMP Option memo. The LMP Option memo also 
indicates that once a state selects the LMP Option and it is in effect, 
the state will be expected to determine, on an annual basis, that the 
LMP criteria are still being met. If a state determines that the LMP 
criteria are not being met, it should take action to reduce 
PM10 concentrations enough to requalify for the LMP. One 
possible approach a state could take is to implement contingency 
measures. Please see section 3.6 of the Whitefish LMP for a description 
of contingency provisions submitted as part of the State's submittal.

G. Does the state have an approved attainment emissions inventory which 
can be used to demonstrate attainment of the NAAQS?

    A state's approved attainment plan should include an emissions 
inventory (attainment inventory) which can be used to demonstrate 
attainment of the NAAQS. The inventory should represent emissions 
during the same 5-year period associated with air quality data used to 
determine whether the area meets the applicability requirements of the 
LMP Option. A state should review its inventory every 3 years to ensure 
emissions growth is incorporated in the attainment inventory if 
necessary. In this instance, Montana completed an attainment year 
inventory for the attainment year 2017 for the Whitefish NAA. The EPA 
has reviewed the 2017 emissions inventories and determined that they 
are current, accurate and complete. In addition, the emissions 
inventory submitted with the LMP for the calendar year 2017 is 
representative of the level of emissions during the time period used to 
calculate the ADC since 2017 is included in the 5-year period used to 
calculate the design concentrations (2015-2019).

H. Does the LMP include an assurance of continued operation of an 
appropriate EPA-approved air quality monitoring network, in accordance 
with 40 CFR part 58?

    The PM10 monitoring network for the Whitefish NAA has 
been developed and maintained in accordance with federal siting and 
design criteria in 40 CFR part 58, appendices D and E and in 
consultation with the EPA Region 8. In section 3.5 of the Whitefish 
LMP, Montana states that it will continue to operate its monitoring 
network to meet EPA requirements.

[[Page 12918]]

I. Does the plan meet the CAA requirements for contingency provisions 
for maintenance plans?

    Section 175A of the CAA states that a maintenance plan must include 
contingency provisions, as necessary, to promptly correct any violation 
of the NAAQS which may occur after redesignation of the area to 
attainment. As explained in the LMP Option memo, these contingency 
measures do not have to be fully adopted at the time of redesignation. 
As noted above, CAA section 175A requirements are distinct from CAA 
section 172(c)(9) contingency measures. Section 3.6 of the Whitefish 
LMP describes a process and timeline to identify and evaluate 
appropriate contingency measures in the event of a quality assured 
violation of the PM10 NAAQS. Upon notification of a 
PM10 exceedance in any of the three areas, the MDEQ and the 
appropriate local government will develop contingency measures designed 
to prevent or correct a violation of the PM10 standard. This 
process will be completed within twelve months of the exceedance 
notification. Upon violating the PM10 standard, the MDEQ and 
local government will determine if the local contingency measures will 
be adequate to prevent further exceedances or violations. If the 
agencies determine that local measures will be inadequate, the MDEQ and 
local government will adopt State-enforceable measures.
    The current and proposed contingency provisions in the Whitefish 
LMP meet the requirements for contingency provisions as outlined in the 
LMP Option memo.

IV. Conformity and the LMP Option

    Section 176(c) of the CAA requires the conformity of federal 
actions to the air quality goals of an NAA or maintenance area. Such 
federal actions include actions on transportation plans, programs and 
projects developed, funded, or approved by federal agencies or by 
recipients of federal funds, as well as more general actions receiving 
federal assistance or approval. Conformity of these two types of 
actions is known, respectively, as ``transportation conformity'' and 
``general conformity.'' The purpose of conformity is to ensure that 
such federal actions will not produce new air quality violations, 
worsen existing violations, or delay timely attainment of the NAAQS. 
The EPA's transportation and general conformity rules are found in 40 
CFR part 93, subparts A and B, respectively.
    The transportation conformity rule generally requires a 
demonstration that emissions from the relevant projects of a 
transportation plan and transportation improvement program covering a 
designated area are consistent with the motor vehicle emissions budget 
(MVEB or `budget') contained in the SIP or maintenance plan for that 
area. The MVEB is the level of mobile source emissions of a pollutant 
relied upon in the attainment or maintenance demonstration to attain or 
maintain the NAAQS in the NAA or maintenance area.
    Under the transportation conformity rule, designated areas meeting 
the criteria for the LMP Option will not be required to satisfy the 
rule's regional emissions analysis requirements (40 CFR 93.109(e)). 
When the EPA approves an LMP, we are concluding that it is unreasonable 
to expect that the qualifying area will experience sufficient growth 
during the maintenance period that a violation of the PM10 
NAAQS would result. Therefore, the EPA is concluding with an LMP 
approval that the area's budget is essentially not constraining for the 
duration of the maintenance period and a regional emissions analysis 
will not be necessary to demonstrate conformity.
    However, because LMP areas are still maintenance areas, approval of 
a Whitefish LMP does not remove certain transportation conformity rule 
requirements for transportation plans, programs, and projects. As an 
isolated rural maintenance area, the Whitefish area will generally be 
subject to the requirements of 40 CFR 93.109(g), as modified by the 
requirements for LMP areas in 40 CFR 93.109(e). Specifically, state 
transportation plans, transportation improvement programs and 
transportation projects still must demonstrate that they are fiscally 
constrained (30 CFR 93.108), are still subject to consultation 
requirements (40 CFR 93.112), and projects must not interfere with the 
implementation of any transportation control measures from the 
applicable implementation plan (40 CFR 93.113).
    Approval of the LMP option would have similar implications with 
respect to general conformity. Federal actions subject to general 
conformity in an LMP area will not be required to satisfy the budget 
test requirement of the general conformity rule. Such federal actions 
are presumed to conform under the LMP option as emissions budgets in 
such areas are essentially not constraining for the duration of the 
maintenance period.

V. Environmental Justice Concerns

    To identify potential environmental burdens and susceptible 
populations in the Whitefish NAA, EPA performed a screening-level 
analysis using the EPA's EJSCREEN tool to evaluate environmental and 
demographic indicators within the area. The tool outputs are contained 
in the docket for this action. The results indicate that the Whitefish 
NAA is not a potential area of EJ concern and is not a candidate for 
further EJ review.\15\
---------------------------------------------------------------------------

    \15\ Region 8, EPA considers an area a ``potential EJ area'' or 
``potential area of EJ concern'', and a candidate for further 
review, if any of the following criteria are met: The area is in the 
80th percentile or above for any EJ index when compared to the 
nation, region, or state, the percentage of Low-income population in 
the area exceeds the state average for the state in which the area 
exist and the percentage of People of Color population in the area 
exceeds the state average for the state in which the area exists.
---------------------------------------------------------------------------

    When the EPA establishes a new or revised NAAQS, the CAA requires 
the EPA to designate all areas of the U.S. as either nonattainment, 
attainment, or unclassifiable. If an area is designated nonattainment 
of the NAAQS, the CAA provides for the EPA to redesignate the area to 
attainment upon a demonstration by the state authority that the 
criteria for a redesignation are met, including a showing that air 
quality is attaining the NAAQS and will continue to maintain the NAAQS 
in order to ensure that all those residing, working, attending school, 
or otherwise present in those areas are protected. This action 
addresses a plan for continued attainment of the PM10 NAAQS 
for the Whitefish NAA. Approval of this plan does not impose any 
additional regulatory requirements on sources beyond those imposed by 
state law. As discussed in this document, Montana has demonstrated that 
the air quality in the Whitefish NAA is attaining the PM10 
NAAQS and will ensure continued attainment of the NAAQS. For these 
reasons, this action does not result in disproportionately high and 
adverse human health or environmental effects on communities with 
environmental justice concerns.

VI. Proposed Action

    For the reasons explained in section III., we are proposing to 
approve the LMP for the Whitefish NAA and the State's request to 
redesignate the Whitefish NAA from nonattainment to attainment for the 
1987 24-hour PM10 NAAQS. Additionally, the EPA is proposing 
to determine that the Whitefish NAA has attained the NAAQS for 
PM10. This determination is based upon monitored air quality 
data for the PM10 NAAQS during the years 2014-2020. The EPA 
is proposing to approve the Whitefish LMP as meeting the appropriate 
transportation conformity requirements found in 40 CFR part 93, subpart 
A.

[[Page 12919]]

VII. 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, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely proposes to approve state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     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 (Pub. L. 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, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the proposed rule does not have tribal implications and will 
not impose substantial direct costs on tribal governments or preempt 
tribal law as specified by Executive Order 13175 (65 FR 67249, November 
9, 2000).

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Greenhouse gases, Incorporation by reference, Intergovernmental 
relations, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting 
and recordkeeping requirements, Sulfur oxides, Volatile organic 
compounds.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
and Wilderness areas.

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

    Dated: February 28, 2022.
K.C. Becker,
Regional Administrator, Region 8.
[FR Doc. 2022-04758 Filed 3-7-22; 8:45 am]
BILLING CODE 6560-50-P