[Federal Register Volume 83, Number 4 (Friday, January 5, 2018)]
[Proposed Rules]
[Pages 636-651]
[FR Doc No: 2018-00037]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R07-OAR-2017-0734; FRL 9972-64-Region 7]

Air Plan Approval and Air Quality Designation; MO; Redesignation
of the Missouri Portion of the St. Louis Missouri-Illinois Area to
Attainment of the 1997 Annual Standard for Fine Particulate Matter and
Approval of Associated Maintenance Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Advanced notice of proposed rulemaking.

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SUMMARY: The Environmental Protection Agency (EPA) is issuing this
Advanced Notice of Proposed Rulemaking (ANPR) to inform the public of
currently available information that will be used by the Administrator
to issue a subsequent action to propose redesignation of the Missouri
portion of the St. Louis MO-IL nonattainment area for the 1997
PM2.5 NAAQS, (hereafter referred to as the ``St. Louis
area'' or ``area''). On September 2, 2011, Missouri, through the
Missouri Department of Natural Resources (MDNR) submitted a request for
EPA to redesignate the Missouri portion of the St. Louis MO-IL
nonattainment area to attainment for the 1997 Annual National Ambient
Air Quality Standards (NAAQS) for fine particulate matter
(PM2.5) and approve a state implementation plan (SIP)
revision containing a maintenance plan for the Missouri portion of the
area. In advance of any potential rulemaking to address the state of
Missouri's request, EPA is specifically requesting early input and
comments on its interpretation that currently available data support a
finding that the area will be attaining the 1997 Annual
PM2.5 NAAQS based on air quality monitoring data from 2015-
2017, and on EPA's advanced notice of its expectation that the state's
plan for maintaining the 1997 Annual PM2.5 NAAQS for the St.
Louis Area (maintenance plan) including the associated motor vehicle
emission budgets (MVEBs) for nitrogen oxides (NOX) and
PM2.5 for the years 2008-2025 is approvable. EPA will take
any information received from this ANPR into consideration when
developing a proposed action for redesignating the Missouri portion of
the St. Louis Area to attainment for the 1997 Annual PM2.5
NAAQS.

DATES: Comments must be received on or before February 5, 2018.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R07-
OAR-2017-0734 to https://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from 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.

FOR FURTHER INFORMATION CONTACT: Lachala Kemp, Environmental Protection
Agency, Air Planning and Development Branch, 11201 Renner Boulevard,
Lenexa, Kansas 66219 at<PHONE_NUMBER>, or by email at
[email protected].

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and
``our'' refer to EPA. This section provides additional information by
addressing the following:

Table of Contents

I. What is the purpose of this Advanced Notice of Proposed
Rulemaking?
II. What future EPA action is discussed in this Advanced Notice of
Proposed Rulemaking?
III. What is the background for EPA's advanced notice?
IV. What is EPA's initial analysis of the state's request?
V. What is EPA's initial analysis of the state's MVEBs?
VI. What is EPA's initial analysis of the state's 2008 emissions
inventory?
VII. Summary of Advanced Notice of Proposed Actions

I. What is the purpose of this Advanced Notice of Proposed Rulemaking?

    The primary purpose of this Advanced Notice of Proposed Rulemaking
or ANPR is to provide the public an opportunity to provide input on the
EPA's approach and initial review of Missouri's request to redesignate
the Missouri portion of the St. Louis bi-state nonattainment area to
attainment for the 1997 PM2.5 NAAQS. Once the 2015-2017
quality assured and certified air monitoring data for the entire bi-
state nonattainment area is available, EPA intends to take action
determining if the area has met the standard and if the state of
Missouri has satisfied the other requirements for redesignating a
nonattainment area to attainment as provided by the Clean Air Act (CAA
or Act). Specifically, section 107(d)(3)(E) of the CAA allows for
redesignation to attainment provided the following criteria are met:
(1) The Administrator determines that the area has attained the
applicable NAAQS, (2) the Administrator has fully approved the
applicable implementation plan for the area under CAA section 110(k),
(3) the Administrator determines that the improvement in air quality is
due to permanent and enforceable reductions in emissions resulting from
implementation of the applicable SIP and applicable Federal air
pollutant control regulations and other permanent and enforceable
reductions, (4) the Administrator has fully approved a maintenance plan
for the area as meeting the requirements of CAA section 175A, and (5)
the state containing such area has met all requirements applicable to
the area under section 110 and part D of title I of the CAA.
    EPA has reviewed Missouri's submittal and additional information
and recognizes that the state's information supports the St. Louis
area's redesignation for the 1997 annual PM2.5 NAAQS. Based
on historical and air quality data collected for the majority of 2017,
it is extremely likely the area will have an attaining design value
based on 2015-2017 air quality data. Provided air quality data for the
remainder of the 2017 calendar year continues to support a finding of
attainment and EPA approves the emissions inventory submitted with the
maintenance plan, EPA expects to approve the area's redesignation.

II. What future EPA action is discussed in this Advanced Notice of
Proposed Rulemaking?

    EPA is providing advanced notice on future actions related to
Missouri's request that the Agency determine that the St. Louis bi-
state nonattainment area for the 1997 annual PM2.5 National
Ambient Air Quality Standard attains the standard and the Agency
officially redesignate the area from nonattainment to attainment.
Missouri submitted their first request to determine attainment and
redesignation on September 1, 2011. The state then supplemented and
revised their request on March 31, 2014, and on September 17, 2014.\1\
In this notice, when EPA refers to Missouri's submission, we are
referring to information provided in the 2011 and 2014 submissions and
the additional clarifying information together unless otherwise
specified. EPA is providing advanced notice related to information that
supports redesignation from nonattainment to attainment for the
Missouri portion of the St. Louis area for the 1997 annual
PM2.5 NAAQS and evaluation of Missouri's 1997 annual
PM2.5 NAAQS maintenance plan, which includes the 2008 and
2025 NOX and PM2.5 MVEBs for the St. Louis area.
EPA evaluated Missouri's request and plan consistent with section 175A
of the CAA and EPA's supplemental analysis that the area will continue
to maintain for ten years following redesignation. The Missouri
counties comprising the St. Louis area are Franklin, Jefferson, St.
Charles and St. Louis. The City of St. Louis is also part of the
nonattainment area.
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    \1\ The date of the original submission is September 2, 2011.
Missouri supplemented and revised their request on March 31, 2014,
September 17, 2014, and May 23, 2017. The May 27, 2017, letter
requested EPA to take action on prior submission, but did not
include additional documentation. EPA considered all submissions in
reviewing and proposing this action.
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III. What is the background for EPA's advanced notice?

    Fine particle pollution can be emitted directly or formed
secondarily in the atmosphere. The main precursors of secondary
PM2.5 are sulfur dioxide (SO2), nitrogen oxides
(NOX), ammonia (NH3), and volatile organic
compounds (VOC). See, e.g., 72 FR 20586, 72 FR 20589. Sulfates are a
type of secondary particle formed from SO2 emissions of
power plants and industrial facilities. Nitrates, another common type
of secondary particle, are formed from NOX emissions of
power plants, automobiles, and other combustion sources of fossil fuel.
    On July 18, 1997, EPA promulgated the first air quality standards
for PM2.5. 62 FR 38652. EPA promulgated an annual standard
at a level of 15 micrograms per cubic meter ([mu]g/m\3\), based on a
three-year average of annual mean PM2.5 concentrations. In
the same rulemaking, EPA promulgated a 24-hour standard of 65 [mu]g/
m\3\, based on a three-year average of the 98th percentile of 24-hour
concentrations. On October 17, 2006, at 71 FR 61144, EPA retained the
annual average NAAQS at 15 [mu]g/m\3\ but revised the 24-hour NAAQS to
35 [mu]g/m\3\, based again on the three-year average of the 98th
percentile of 24-hour

concentrations.\2\ Under EPA regulations at 40 CFR part 50, the primary
and secondary 1997 annual PM2.5 NAAQS are attained when the
annual arithmetic mean concentration, as determined in accordance with
40 CFR part 50, appendix N, is less than or equal to 15.0 [micro]g/m\3\
at all relevant monitoring sites in the subject area over a three-year
period.
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    \2\ In response to legal challenges of the annual standard
promulgated in 2006, the United States Courts of Appeals for the
District of Columbia Circuit (D.C. Cir.) remanded that NAAQS to EPA
for further consideration. See American Farm Bureau Federation and
National Pork Producers Council, et al. v. EPA, 559 F.3d (D.C. Cir.
2009). However, given that the 1997 and 2006 annual NAAQS are
essentially identical, attainment of the 1997 annual NAAQS would
also indicate attainment of the remanded 2006 annual NAAQS.
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    On January 5, 2005, at 70 FR 944, and supplemented on April 14,
2005, at 70 FR 19844, EPA designated the St. Louis area as
nonattainment for the 1997 PM2.5 annual NAAQS. In that
action, EPA defined the 1997 annual PM2.5 St. Louis
nonattainment area to include Jefferson, Franklin, St. Charles, and St.
Louis Counties along with the City of St. Louis on the Missouri side,
and Madison, Monroe, and St. Clair Counties as well as the Baldwin
Township of Randolph County on the Illinois side of the nonattainment
area.
    On November 13, 2009, EPA promulgated designations for the 24-hour
standard established in 2006, designating the St. Louis area as
attainment for that NAAQS (74 FR 58688). That action clarified that the
St. Louis area was classified as unclassifiable/attainment for the 1997
24-hour PM2.5 NAAQS. EPA did not promulgate designations for
the 2006 annual PM2.5 NAAQS because that NAAQS was
essentially identical to the 1997 annual PM2.5 NAAQS, and
today's action only addresses the 1997 annual PM2.5 NAAQS
designation.
    All 1997 PM2.5 NAAQS areas were designated under subpart
1. Subpart 1 contains the general requirements for nonattainment areas
for any pollutant governed by a NAAQS and is less prescriptive than the
other subparts of title I, part D. On April 25, 2007 (72 FR 20586), EPA
promulgated its Clean Air Fine Particle Implementation Rule, codified
at 40 CFR part 52, subpart Z, in which the Agency provided guidance for
state and tribal plans to implement the 1997 PM2.5 NAAQS.
The DC Circuit remanded the Clean Air Fine Particle Implementation Rule
and the final rule entitled ``Implementation of the New Source Review
(NSR) Program for Particulate Matter Less than 2.5 Micrometers
(PM2.5)'' (73 FR 28321, May 16, 2008) (collectively, ``1997
PM2.5 Implementation Rules'') to EPA on January 4, 2013, in
Natural Resources Defense Council v. EPA, 706 F.3d 428 (D.C. Cir.
2013). The Court found that EPA erred implementing the 1997
PM2.5 NAAQS pursuant to the general implementation
provisions of subpart 1, rather than the particulate matter-specific
provisions of subpart 4.
    On July 29, 2016, EPA issued a rule entitled, ``Fine Particulate
Matter National Ambient Air Quality Standards: State Implementation
Plan Requirements'' (PM2.5 SIP Requirements Rule) that
clarifies how states should meet the statutory SIP requirements that
apply to areas designated nonattainment for any PM2.5 NAAQS
under subparts 1 and 4. See 81 FR 58010 (August 24, 2016). It does so
by establishing regulatory requirements and providing guidance that is
applicable to areas that are currently designated nonattainment for
existing PM2.5 NAAQS and areas that are designated
nonattainment for any PM2.5 NAAQS in the future. In
addition, the rule responds to the D.C. Circuit's remand of the 1997
PM2.5 Implementation Rules. As a result, the requirements of
the rule also govern future actions associated with states' ongoing
implementation efforts for the 1997 and 2006 PM2.5 NAAQS.
    In the PM2.5 SIP Requirements Rule, EPA revoked the 1997
primary Annual PM2.5 NAAQS in areas that had always been
attainment for that NAAQS, and in areas that had been designated as
nonattainment but that were redesignated to attainment before October
24, 2016, the rule's effective date. See 81 FR 58010 (August 24, 2016).
EPA also finalized a provision that revokes the 1997 primary Annual
PM2.5 NAAQS in areas that are redesignated to attainment for
that NAAQS after October 24, 2016, effective on the effective date of
the redesignation of the area to attainment for that NAAQS. See 40 CFR
50.13(d). EPA is providing advanced notice of its expectation to
redesignate the St. Louis area to attainment for the 1997 Annual
PM2.5 NAAQS and to approve the CAA 175A maintenance plan for
the 1997 Annual PM2.5 NAAQS in a future action, for the
reasons described elsewhere in this advanced notice.\3\ If the action
is finalized, the 1997 primary Annual PM2.5 NAAQS will be
revoked in the Missouri portion of the St. Louis Area on the effective
date of the redesignation. Beginning on that date, the Missouri portion
of the St. Louis Area will no longer be subject to transportation or
general conformity requirements for the 1997 Annual PM2.5
NAAQS due to the revocation of the primary NAAQS. See 81 FR 58125. The
Missouri portion of the St. Louis Area will be required to implement
the CAA section 175A maintenance plan for the 1997 Annual
PM2.5 NAAQS and the prevention of significant deterioration
(PSD) program for the 1997 Annual PM2.5 NAAQS. Once
approved, the maintenance plan can only be revised if the revision
meets the requirements of CAA Section 110(l) and, if applicable CAA
section 193. The Area would not be required to submit a second 10-year
maintenance plan for the 1997 Annual PM2.5 NAAQS. See 81 FR
58144.
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    \3\ CAA Section 175A(a) established the requirements that must
be fulfilled by nonattainment areas in order to be redesignated to
attainment. That section only requires that nonattainment areas for
the primary standard submit a plan addressing maintenance of the
primary NAAQS in order to be redesignated to attainment; it does not
require nonattainment areas for secondary NAAQS to submit
maintenance plans in order to be redesignated to attainment.
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IV. What is EPA's initial analysis of the state's request?

    As stated above, EPA is providing advanced notice that in a future
action it intends to formally act on Missouri's request to redesignate
the Missouri portion of the St. Louis area to attainment for the 1997
annual PM2.5 NAAQS and Missouri's plan for maintaining the
1997 Annual PM2.5 NAAQS for the St. Louis portion of the
area, including finding the associated MVEBs for 2008 and 2025 as
adequate using criteria in 40 CFR 93.118(e)(4) and (5). EPA is issuing
this advanced notice of proposed rulemaking because the information
currently before the agency strongly supports a redesignation of the
St. Louis area to attainment for the 1997 annual PM2.5
NAAQS, with the exception of a small amount of air quality data for the
2017 calendar year, which EPA expects the states of Missouri and
Illinois to certify in early 2018. Assuming, as EPA fully expects, that
the remaining air quality data continue to support a finding that the
area will have attained the 1997 standard based on monitoring data from
2015-2017, EPA intends to propose approval of Missouri's redesignation
request for its portion of the St. Louis 1997 PM2.5
nonattainment area. EPA's evaluation of whether Missouri's request for
the area satisfies the five redesignation criteria provided under CAA
section 107(d)(3)(E), based on currently available information, is
discussed in greater detail in the following paragraphs of this
section.

Criteria (1)--Attainment of the 1997 Annual PM2.5 NAAQS

    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the area has

attained the applicable NAAQS (CAA section 107(d)(3)(E)(i)). An area's
attainment of the 1997 annual PM2.5 NAAQS is determined in
accordance with 40 CFR 50.7 and appendix N of part 50, which requires
three complete, consecutive calendar years of quality-assured air
quality monitoring data. To attain this NAAQS, the three-year average
of the annual arithmetic mean concentration, as determined in
accordance with 40 CFR part 50, appendix N, must be less than or equal
to 15.0 [micro]g/m\3\ at all relevant monitoring sites in the subject
area over a three-year period. The relevant data must be collected and
quality-assured in accordance with 40 CFR part 58 and recorded in the
EPA Air Quality System (AQS) database.
    On May 23, 2011, EPA determined that the St. Louis area was
attaining the 1997 annual PM2.5 NAAQS (76 FR 29652). In that
action, EPA reviewed PM2.5 monitoring data from monitoring
stations in the area for the 1997 annual PM2.5 NAAQS for
2007-2009. This data was quality-assured and recorded in AQS. The
design value for 2007-2009 was 14.1 [mu]g/m\3\ for the St. Louis area
which met the NAAQS. On June 27, 2012 (77 FR 38183), EPA also finalized
a determination that the St. Louis area attained the 1997 annual
PM2.5 NAAQS by the applicable attainment date of April 5,
2010.
    In August of 2014, EPA Region 7 received notice that EPA Region 5
conducted a technical systems audit regarding the weighing of
PM2.5 samples in Illinois. The audit revealed that the Cook
County Department of Environmental Control, which weighs all of the
filters in Illinois' monitoring network, did not have the appropriate
equipment for determining whether the laboratory conditions met the
temperature and humidity criteria in 40 CFR 50 appendix L for proper
conditioning of filters. The instantaneous temperature and humidity
information collected during the audit suggested that many of the
sample weighings failed to meet these criteria. As a result, no filter-
based PM2.5 site in Illinois has sufficient, valid Federal
Reference Method (FRM) data from 2011 through 2013. EPA is aware that
the monitors in the Illinois portion of the St. Louis area started
recording valid data in AQS in the 3rd quarter of 2014 and that a valid
annual mean can only be determined, to date, for the years 2015 and
2016 from those Illinois monitors. EPA completed a review of the
recorded data from the entire nonattainment area from 2015, 2016, and
the first two quarters of 2017 and believes that this data is
indicative of air quality that will support a finding that the area is
attaining the 1997 PM2.5 annual NAAQS based on 2015-2017 air
quality monitoring data. Assuming the complete, quality assured data
for 2017 continues to support that finding, EPA in a future action
intends to take future action regarding Missouri's request to
redesignate the Missouri portion of the St. Louis area to attainment
for the 1997 annual PM2.5 NAAQS.
    To evaluate how likely it is that the area will have an attaining
design value, once all air quality data for the 2017 calendar year is
complete and certified, EPA calculated critical values that would be
required for the area to be in violation of the NAAQS. EPA has
calculated the critical values in two ways; for the entire year of 2017
and for the remaining two quarters of 2017. Table 1 provides the area's
critical values. Both the annual and quarterly critical values greatly
exceed recently recorded levels, indicating that it is extremely
unlikely that the area's design value will be in violation of the NAAQS
based on 2015-2017 air quality data. The data analysis of critical
values in 2017 demonstrates that all the monitors should easily attain
the PM2.5 NAAQS as the critical values are well above what
is currently measured or historically measured at any of the St. Louis
PM2.5 monitors.

                                     Table 1--Critical Values for the St. Louis Area for the 1997 Annual PM2.5 NAAQS
                                                                      [[mu]g/m\3\]
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                                                                                Critical value
              State                      County              Monitor         AQS site ID     2015     2016     2017    DV \2\   Critical   3rd/4th qtrs
                                                                                \1\             value \3\        \4\
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Missouri........................  St. Louis City.....  Blair Street (FRM)     29-510-0085     10.4      8.5      7.4      8.8       26.1            44.8
Missouri........................  St. Louis City.....  South Broadway....     29-510-0007     11.1      8.1      7.0      8.7       25.8            44.6
Missouri........................  Jefferson..........  Arnold West.......     29-099-0019     11.6      8.3      8.0      9.3       25.1            42.2
Missouri........................  St. Louis County...  Ladue.............     29-189-3001     10.3      8.7      9.2      9.4       26.0            42.8
Missouri........................  St. Louis City.....  Forest Park.......     29-510-0094      9.2      8.7      7.7      8.5       27.1            46.5
Illinois........................  Madison............  Alton.............     17-119-2009      9.0      8.8      8.6      8.8       27.2            45.8
Illinois........................  Madison............  Wood River........     17-119-3007      9.1      8.7      8.2      8.7       27.2            46.2
Illinois........................  Madison............  Granite City......     17-119-1007     10.4      9.1      8.8      9.4       25.5            42.2
Illinois........................  St. Clair..........  East St. Louis....     17-163-0010     10.7     10.0      8.3      9.7       24.3            40.3
Illinois........................  Jersey.............  Jerseyville.......     17-083-1001      7.7      7.9      8.9      8.2       29.4            49.9
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\1\ Only first 2 quarters of 2017 data are complete and reported to AQS.
\2\ 2015-2017 design values not yet valid since only the first 2 quarters of 2017 data being reported to AQS.
\3\ To determine the critical value for the 2012 NAAQS, and knowing that the average annual value over 3 years must be less than or equal to 15 [micro]g/
  m\3\, EPA used the following formula (y1 + y2 + y3)/3 <= 15 solving for year 3 (y3). Where y3 = 45 - y1 - y2 is the critical value for y3 in the
  equation.
\4\ Having 2 quarters of data in 2017 (y3), EPA was able to determine how high the average of the last two quarters could be by utilizing the following
  formula (Q12 + Q34)/2 <= annual critical value where Q34 <= 2 * CV - Q12.

    If there is any indication that the area is not attaining the 1997
annual PM2.5 NAAQS, EPA will not go forward with acting on
Missouri's request to redesignate the area. MDNR has committed to
continue monitoring in this area in accordance with 40 CFR part 58.
    In summary, EPA is providing for the public's review the currently
available air quality data, including all data submitted by Missouri to
AQS, as well as EPA's analysis of the critical values for both 2017 and
the last two quarters of 2017 which indicate it is extremely likely
that the area will have an attaining design value once the 2017 data
are complete and quality-assured. EPA is requesting the public's
comments and feedback on the data and analysis provided, and is
providing advanced notice that it intends to use this information in
support of a

proposal for redesignation of the St. Louis area.

Criteria (2)--the Area Has a Fully Approved SIP Under Section 110(k);
and Criteria (5)--The Missouri Portion of the St. Louis Area Has Met
All Applicable Requirements Under Section 110 and Part D of the CAA

    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the state has met all applicable
requirements under section 110 and part D of title I of the CAA (CAA
section 107(d)(3)(E)(v)) and that the state has a fully approved SIP
under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA
is providing advanced notice of its review of Missouri's redesignation
and believes Missouri has submittal all applicable SIP requirements for
purposes of redesignation for the Missouri portion of the St. Louis
area under section 110 of the CAA (general SIP requirements) and part D
of title I.
    EPA has ascertained which requirements are applicable to the
Missouri portion of the St. Louis area and, if applicable, determined
that they are, or will be, fully approved through this action under
section 110(k) of the CAA. See sections (a) and (b) below. EPA notes
that SIPs must be fully approved only with respect to requirements that
were due prior to submittal of the complete redesignation request.
a. The Missouri Portion of the St. Louis Area Has Met All Applicable
Requirements for Purposes of Redesignation Under Section 110 and Part D
of the CAA
    General SIP requirements. Section 110(a)(2) of title I of the CAA
delineates the general requirements for a SIP, which include
enforceable emissions limitations and other control measures, means, or
techniques; provisions for the establishment and operation of
appropriate devices necessary to collect data on ambient air quality;
and programs to enforce the limitations. General SIP elements and
requirements are delineated in section 110(a)(2). These
``infrastructure'' requirements include, but are not limited to, the
following: (1) Submittal of a SIP that has been adopted by the state
after reasonable public notice and hearing; (2) provisions for
establishment and operation of appropriate procedures needed to monitor
ambient air quality; (3) implementation of a source permit program;
provisions for the implementation of part C requirements (Prevention of
Significant Deterioration (PSD)); (4) provisions for the implementation
of part D requirements (Nonattainment New Source Review (NNSR) permit
programs); (5) provisions for air pollution modeling; and (6)
provisions for public and local agency participation in planning and
emission control rule development.
    EPA has long interpreted section 110(a)(2) elements that are
neither connected with nonattainment plan submissions nor linked with
an area's attainment status not to be applicable requirements for
purposes of redesignation, under the theory that states were required
to fulfill these obligations as to a particular NAAQS regardless of the
designation status of any specific area. As noted above, this advanced
notice of redesignation also has the effect of revoking the 1997
PM2.5 NAAQS for the St. Louis Area, and thus the section
110(a)(2) general SIP requirements will no longer be in force for the
1997 standard upon the effective date of the redesignation. However,
the 1997 standard was superseded by the more stringent 2012
PM2.5 NAAQS, and all states are required to comply with
section 110(a)(2) for that more stringent standard. The Missouri
portion of the St. Louis area (and Missouri in general) continues to be
subject to the section 110(a)(2) general SIP requirements for the more
stringent 2012 PM2.5 NAAQS notwithstanding the expected
redesignation and revocation. In any case, EPA has previously approved
provisions of Missouri's SIP addressing CAA section 110(a)(2)
requirements including provisions addressing the 1997 PM2.5
NAAQS on May 8, 2007 (72 FR 25975), and June 21, 2013 (78 FR 37457). In
summary, EPA does not interpret the section 110(a)(2) requirements to
be applicable for purposes of redesignation under sections
107(d)(3)(E)(ii) and (v), and in any case those provisions have been
fully approved.
    Part D Requirements. EPA is providing advanced notice that upon
final approval of the 2008 comprehensive emissions inventory discussed
in section VII of this rulemaking, the Missouri SIP will meet the
applicable SIP requirements for the Missouri portion of the St. Louis
area for purposes of redesignation under part D of the CAA. Subpart 1
of part D, found in sections 171-179 of the CAA, sets forth the basic
nonattainment requirements applicable to all nonattainment areas. For
purposes of evaluating this redesignation request, the applicable part
D, subpart 1 SIP requirements for all nonattainment areas are contained
in sections 172(c)(1)-(9) and in section 176. A thorough discussion of
the applicable requirements contained in section 172 can be found in
the General Preamble for Implementation of title I (57 FR 13498, April
16, 1992). In section V of this proposed rulemaking, EPA discusses the
relationship between this proposed redesignation action and subpart 4
of part D.
    Subpart 1 section 172 Requirements. Sections 172 to 175 of the CAA,
set forth the basic nonattainment plan requirements applicable to
PM2.5 nonattainment areas. Under CAA section 172, states
with nonattainment areas must submit plans providing for timely
attainment and meet a variety of other requirements. On May 23, 2011
(76 FR 29652), EPA made a determination that the St. Louis area had
attained the 1997 annual PM2.5 NAAQS. This determination was
based upon complete, quality-assured, and certified ambient air
monitoring data that showed that the area monitored attainment of the
1997 annual PM2.5 NAAQS during the 2007-2009 monitoring
period. Pursuant to 40 CFR 51.1004(c), upon determination by EPA that
an area designated nonattainment for the PM2.5 NAAQS has
attained the standard, the requirement for such an area to submit an
attainment demonstration and associated reasonably achievable control
technology (RACT)/reasonably achievable control measures (RACM), a
reasonable further progress (RFP) plan, contingency measures, and other
planning SIPs related to the attainment of the PM2.5 NAAQS
are suspended until the area is redesignated to attainment or EPA
determines that the area has violated the PM2.5 NAAQS, at
which time such plans are again required to be submitted. As a result
of the determination of attainment, the only remaining requirement
under CAA section 172 to be considered is the emissions inventory
required to be submitted and approved by EPA under CAA section
172(c)(3).
    In this advanced notice, as discussed further in section VI, EPA is
providing advanced notice of Missouri's 2008 base year emissions
inventory and intends to approve the emissions inventory in a future
action in accordance with section 172(c)(3) of the CAA.\4\ Because
Missouri withdrew their nonattainment SIP submittal, which included the
2002 baseyear emissions inventory after EPA finalized the Clean Data
Determination (76 FR 29652) for the Missouri portion of the St. Louis
nonattainment area in

2011, EPA believes the 2008 base year emissions inventory is an
appropriate baseyear emissions inventory requirement under section
172(c)(3) of the CAA. For more information on EPA's analysis of the
2008 base year emissions inventory, see EPA's ``Emissions Inventory and
Motor Vehicle Emissions Budget (MVEB) Technical Support Document (TSD)
for the Redesignation Request and Maintenance Plan for the St Louis,
Missouri 1997 PM2.5 Nonattainment Area'', available online
at www.regulations.gov, Docket ID No. EPA-R07-OAR-2017-0734.
---------------------------------------------------------------------------

    \4\ EPA's longstanding guidance on redesignations, entitled
``Processing Redesignations to Attainment,'' John Calcagni 1992,
notes that the subpart 1 emissions inventory requirement is
satisfied by the maintenance plan inventory requirements.
---------------------------------------------------------------------------

    The General Preamble for Implementation of title I also discusses
the evaluation of these requirements in the context of EPA's
consideration of a redesignation request. The General Preamble sets
forth EPA's view of applicable requirements for purposes of evaluating
redesignation requests when an area is attaining the standard. See
General Preamble for Implementation of title I (57 FR 13498, April 16,
1992).
    Because attainment has been reached for the area, no additional
measures are needed for attainment, and CAA section 172(c)(1)
requirements for an attainment demonstration and RACT/RACM are no
longer considered to be applicable for purposes of redesignation as
long as the area continues to attain the standard until redesignation.
See 40 CFR 51.1004(c). The RFP requirement under CAA section 172(c)(2)
and contingency measures requirement under CAA section 172(c)(9) are
similarly not relevant for purposes of redesignation.
    Section 172(c)(4) of the CAA requires the identification and
quantification of allowable emissions for new and modified major
stationary sources in an area, and CAA section 172(c)(5) requires
source permits for the construction and operation of new and modified
major stationary sources anywhere in the nonattainment area. EPA has
determined that, since the PSD requirements will apply after
redesignation, areas being redesignated need not comply with the
requirement that a nonattainment NSR (NNSR) program be approved prior
to redesignation, provided that the area demonstrates maintenance of
the NAAQS without part D NSR. A more detailed rationale for this view
is described in a memorandum from Mary Nichols, Assistant Administrator
for Air and Radiation, dated October 14, 1994, entitled, ``Part D New
Source Review Requirements for Areas Requesting Redesignation to
Attainment.'' Nevertheless, Missouri currently has an approved NNSR
program and Missouri's PSD program for the 1997 annual PM2.5
NAAQS will become effective in the Missouri portion of the St. Louis
area upon redesignation to attainment.
    Section 172(c)(6) of the CAA requires the SIP to contain control
measures necessary to provide for attainment of the NAAQS. Because
attainment has been reached for the Missouri portion of the St. Louis
area, no additional measures are needed to provide for attainment.
    Section 172(c)(7) of the CAA requires the SIP to meet the
applicable provisions of CAA section 110(a)(2). As noted previously, we
believe the Missouri SIP meets the requirements of CAA section
110(a)(2) that are applicable for purposes of redesignation.
    Subpart 1 Section 176 Conformity Requirements. Section 176(c) of
the CAA requires states to establish criteria and procedures to ensure
that Federally supported or funded projects conform to the air quality
planning goals in the applicable SIP. The requirement to determine
transportation conformity applies to transportation plans, programs,
and projects developed, funded or approved under Title 23 of the United
States Code (U.S.C.) and the Federal Transit Act (transportation
conformity) as well as to all other Federally supported or funded
projects (general conformity). EPA approved the most recent revisions
to the transportation conformity SIP for the Missouri portion of the
St. Louis area on August 29, 2013 (78 FR 53247).
    Thus, for purposes of redesignating the Missouri portion of the St.
Louis area to attainment, EPA is providing advanced notice of our
determination and believes Missouri has satisfied all applicable
requirements for purposes of redesignation for the Missouri portion of
the St. Louis area under CAA section 110, and upon final approval of
the 2008 base year emissions inventory, also will have satisfied all
applicable requirements under part D of title I of the CAA.
    Subpart 4 Requirements. As discussed above, in NRDC v. EPA, the
Circuit held that EPA should have implemented the 1997 PM2.5
NAAQS pursuant to the particulate matter-specific provisions of subpart
4. On remand, EPA identified all areas designated nonattainment for
either the 1997 or the 2006 PM2.5 NAAQS, including the St.
Louis Area, as moderate nonattainment areas for purposes of Subpart 4
in the Classification and Deadlines Rule. Moderate nonattainment areas
are subject to the requirements of sections 189(a), (c), and (e),
including: (1) An approved permit program for construction of new and
modified major stationary sources (section 189(a)(1)(A)); (2) an
attainment demonstration (section 189(a)(1)(B)); (3) provisions for
RACM (section 189(a)(1)(C)); (4) quantitative milestones demonstrating
RFP toward attainment by the applicable attainment date (section
189(c)); and (5) precursor control (section 189(e)).14
    With respect to the specific attainment planning requirements under
subpart 4,\5\ EPA applies the same interpretation that it applies to
attainment planning requirements under Subpart 1 or any of the other
pollutant- specific subparts. That is, under its long-standing
interpretation of the CAA, where an area is already attaining the
standard, EPA does not consider those attainment planning requirements
to be applicable for purposes of evaluating a request for
redesignation, that is, CAA section 107(d)(3)(E)(ii) or (v), because
requirements that are designed to help an area achieve attainment no
longer have meaning where an area is already meeting the standard. EPA
has proposed to determine that the area has attained the 1997 Annual
PM2.5 Standard. Therefore, under its longstanding
interpretation, EPA is providing advance notice that the requirements
to submit an attainment demonstration under section 189(a)(1)(B) and a
RFP demonstration under section 189(c)(1) are not applicable for
purposes of evaluating Missouri's redesignation request.
---------------------------------------------------------------------------

    \5\ These planning requirements include the attainment
demonstration, quantitative milestone requirements, and RACM
analysis.
---------------------------------------------------------------------------

    The permit requirements of subpart 4, contained in section
189(a)(1)(A), refer to and apply the subpart 1 permit provisions
requirements of sections 172 and 173 to PM10, without adding
to them. Consequently, EPA believes that section 189(a)(1)(A) does not
itself impose for redesignation purposes any additional requirements
for moderate areas beyond those contained in subpart 1.\6\ As discussed
above, EPA has long relied on the interpretation that a fully approved
nonattainment new source review program is not considered an applicable
requirement for redesignation, provided the area can maintain the
standard with a PSD program after redesignation. A detailed rationale
for this view is described in the Nichols Memorandum. See also
rulemakings for the Illinois portion of the St. Louis Area (77 FR
34819, 77 FR 34826, June 12, 2012); Louisville, Kentucky (66 FR 53665-
66 FR 53669, October 23, 2001); Grand Rapids, Michigan (61 FR 31831, 61
FR 31834-

61 FR 31837, June 21, 1996); Cleveland-Akron-Lorain, Ohio 61 FR 20458,
61 FR 20469-61 FR 20470, May 7, 1996); Detroit, Michigan (60 FR, 12467-
60 FR 12468, March 7, 1995).
---------------------------------------------------------------------------

    \6\ The potential effect of section 189(e) on section
189(a)(1)(A) for purposes of evaluating this redesignation is
discussed below.
---------------------------------------------------------------------------

    Subpart 4 and the Control of PM2.5 Precursors. CAA
section 189(e) provides that control requirements for major stationary
sources of direct PM10 (including PM2.5) shall
also apply to PM precursors from those sources, except where EPA
determines that major stationary sources of such precursors ``do not
contribute significantly to PM10 levels which exceed the
standard in the area.'' The CAA does not explicitly address whether it
would be appropriate to include a potential exemption from precursor
controls for all source categories under certain circumstances. In
implementing subpart 4 with regard to controlling PM10, EPA
permitted states to determine that a precursor was ``insignificant''
where the state could show in its attainment plan that it would
expeditiously attain without adoption of emission reduction measures
aimed at that precursor. This approach was upheld in Association of
Irritated Residents v. EPA, 423 F.3d 989 (9th Cir. 2005) and extended
to PM2.5 implementation in the PM Implementation Rule. A
state may develop its attainment plan and adopt reasonably available
control measures that target only those precursors that are necessary
to control for purposes of timely attainment. See 81 FR 58020. In the
rule, EPA also finalized application of 189(e) to the NNSR permitting
program, requiring states to determine whether a new major source of a
precursor might have a significant contribution to air quality before
allowing exemption of controls of a precursor from a new major
stationary source or major modification in the text of that program.
See 81 FR 58026.
    Therefore, because the requirement of section 189(e) is primarily
actionable in the context of addressing precursors in an attainment
plan and in NNSR permitting, a precursor exemption analysis under
section 189(e) and EPA's implementing regulations is not an applicable
requirement that needs to be fully approved in the context of a
redesignation under CAA section 107(d)(3)(E)(ii). As discussed above,
for areas that are attaining the standard, EPA does not interpret
attainment planning requirements of subparts 1 and 4 to be applicable
requirements for the purposes of redesignating an area to attainment
nor does it interpret NNSR to be an applicable requirement if the area
can maintain the NAAQS with a PSD program after redesignation. However,
to the extent that Missouri is required to conduct a precursor
exemption analysis in order to satisfy 189(e) in the context of its
RACM determination for the St. Louis Area, which is required pursuant
to the Sixth Circuit's decision in Sierra Club, EPA proposes to find
that the requirements of section 189(e), as interpreted by EPA's
regulations, are met in this case. The area has attained the 1997
Annual PM2.5 NAAQS, and therefore, no additional controls of
any pollutant, including any PM2.5 precursors, are necessary
to bring the area into attainment.\7\ For these reasons, EPA is
providing advance notice that it believes Missouri has satisfied all
applicable requirements for purposes of redesignation of it portion of
the St. Louis area under section 110 and part D of the CAA.
---------------------------------------------------------------------------

    \7\ The Missouri portion the St. Louis area contains no major
stationary sources of ammonia, and existing major stationary sources
of VOC are adequately controlled under other provisions of the CAA
regulating the ozone NAAQS. The St. Louis area has reduced VOC
emissions through the implementation of various control programs
including VOC Reasonably Available Control Technology regulations
and various on-road and non-road motor vehicle control programs.
---------------------------------------------------------------------------

b. The Missouri Portion of the St. Louis Area Has a Fully Approved
Applicable SIP Under Section 110(k) of the CAA
    Upon final approval of the comprehensive emissions inventory in a
future notice, EPA will have fully approved the state's SIP for the
Missouri portion of the St. Louis area for the 1997 annual
PM2.5 nonattainment area under section 110(k) of the CAA for
all requirements applicable for purposes of redesignation. EPA may rely
on prior SIP approvals in approving a redesignation request (see
Calcagni Memorandum at p. 3; Southwestern Pennsylvania Growth Alliance
v. Browner, 144 F.3d 984, 989-90 (6th Cir. 1998); Wall, 265 F.3d 426
(6th Cir. 2001, upholding this interpretation)) plus any additional
measures it may approve in conjunction with a redesignation action (see
68 FR 25426 (May 12, 2003) and citations therein). Following passage of
the CAA of 1970, Missouri has adopted and submitted, and EPA has fully
approved at various times, provisions addressing the various SIP
elements applicable for the 1997 annual PM2.5 NAAQS in the
St. Louis area (e.g., 78 FR 37457, June 21, 2013).
    As indicated above, EPA believes that the section 110 elements not
connected with nonattainment plan submissions and not linked to the
area's nonattainment status are not applicable requirements for
purposes of redesignation. EPA has previously approved all part D
subpart 1 requirements applicable for purposes of this redesignation.

Criteria (3)--The Air Quality Improvement Is Due to Permanent and
Enforceable Reductions in Emissions Resulting From Implementation of
the SIP and Applicable Federal Air Pollution Control Regulations and
Other Permanent and Enforceable Reductions (Section 107(d)(3)(E)(iii))

    For redesignating a nonattainment area to attainment, section
107(d)(3)(E)(iii) of the CAA requires EPA to determine that the air
quality improvement in the area is due to permanent and enforceable
reductions in emissions resulting from implementation of the SIP and
applicable Federal air pollution control regulations and other
permanent and enforceable reductions. EPA is providing advanced notice
that it believes that Missouri has demonstrated that the observed air
quality improvement in the St. Louis area is due to permanent and
enforceable reductions in emissions resulting from implementation of
the SIP, Federal measures, and other state adopted measures discussed
below.
    In making this demonstration, MDNR has calculated the change in
emissions from a nonattainment year inventory to an attainment year
inventory. For the nonattainment inventory, Missouri developed a 2002
base year emissions inventory, which the state subsequently withdrew
once a Clean Data Determination was finalized for the Missouri portion
of the St. Louis nonattainment area. For purposes of their
redesignation request, Missouri developed a baseyear emissions
inventory for 2008, one of the years the St. Louis area monitored
attainment of the standard. See section b. below for discussion on
development of these inventories. The reduction in emissions and the
corresponding improvement in air quality over this time period can be
attributed to a number of permanent and enforceable regulatory control
measures that St. Louis and upwind areas have implemented in recent
years.
a. Permanent and Enforceable Controls Implemented
    The following is a discussion on the permanent and enforceable
measures that have been implemented in the area.\8\ Reductions in
PM2.5 precursor emissions have occurred statewide and

in upwind areas as a result of Federal emission control measures, with
additional emission reductions expected to occur in the future. Federal
emission control measures include the following:
---------------------------------------------------------------------------

    \8\ It should be noted that the mobile source controls discussed
below also provide reductions in VOC and/or SO2
emissions. While those emissions may be reduced, the submitted
maintenance plan and redesignation request do not rely on these
emission reductions.
---------------------------------------------------------------------------

    Tier 2 vehicle standards and low-sulfur gasoline. Implementation of
the Tier 2 vehicle standards began in 2004, and as newer, cleaner cars
enter the national fleet, these standards continue to significantly
reduce NOX emissions. The standards require all classes of
passenger vehicles in any manufacturer's fleet to meet an average
standard of 0.07 grams of NOX per mile. In addition,
starting in January of 2006, the Tier 2 rule reduced the allowable
sulfur content of gasoline to 30 parts per million (ppm). Most gasoline
sold prior to this had a sulfur content of approximately 300 ppm. EPA
expects that these standards will reduce NOX emissions from
vehicles by approximately 74 percent by 2030, translating to nation-
wide reductions of nearly 3 million tons annually by 2030.
    Heavy-duty gasoline and diesel highway vehicle standards and ultra-
low-sulfur diesel rule. On October 6, 2000, EPA promulgated a rule to
reduce NOX and VOC emissions from heavy-duty gasoline and
diesel highway vehicles that began to take effect in 2004 (65 FR
59896). On January 18, 2001, (66 FR 5002) EPA promulgated a second
phase of standards and testing procedures began in 2007 to reduce
particulate matter from heavy-duty highway engines, and reduce highway
diesel fuel sulfur content to 15 ppm since the sulfur in fuel damages
high efficiency catalytic exhaust emission control devices. The total
program is estimated to achieve a ninety percent reduction in
PM2.5 emissions and a ninety-five percent reduction in
NOX emission for new engines using low-sulfur diesel fuel,
compared to existing engines using higher-content sulfur diesel fuel.
EPA expects that this rule will reduce NOX emissions by 2.6
million tons nation-wide by 2030 when the heavy-duty vehicle fleet is
completely replaced with newer heavy-duty vehicles that comply with
these emission standards.
    Tier 4 Non-Road Diesel Engine Rule. This rule, which applies to
diesel engines used in industries such as construction, agriculture,
and mining, was promulgated in 2004 and fully phased in 2014. This rule
reduced allowable non-road diesel fuel sulfur levels from approximately
3,000 ppm to 500 ppm in 2007 and further reduced those levels to 15 ppm
starting in 2010 (a 99 percent reduction). This rule also achieved
significant reductions for up to 90 percent for NOX and
particulate matter emissions nationwide.
    Nonroad Large spark-ignition engines and recreational engines
standards. The nonroad spark-ignition and recreational engine
standards, effective in July 2003, regulate NOX, and
hydrocarbons, and carbon monoxide from groups of previously unregulated
non-road engines. (67 FR 68242). These engine standards apply to large
spark-ignition engines (e.g., forklifts and airport ground service
equipment), recreational vehicles (e.g., off-highway motorcycles and
all-terrain-vehicles), and recreational marine diesel engines sold in
the United States and imported after the effective date of these
standards.
    When all of the nonroad spark-ignition and recreational engine
standards are fully implemented, an overall seventy-two percent
reduction in hydrocarbons, eighty percent reduction in NOX,
and fifty-six percent reduction in carbon monoxide emissions is
expected by 2020. These controls will help reduce ambient
concentrations of fine particulate matter.
    Tier 3 Motor Vehicles Emission and Fuel Standards: On April 24,
2014 (79 FR 23414), EPA finalized a rule designed to reduce air
pollution from passenger cars and trucks. The vehicle emissions
standard began in 2017, and combined with the reduction of gasoline
sulfur content will significantly reduce motor vehicle emissions
including NOX, VOC, PM2.5, Carbon Monoxide and
air toxics by 2030, which will help the area maintain the 1997
PM2.5 annual NAAQS.
    NOX SIP Call. On October 27, 1998 (63 FR 57356), EPA issued the
NOX SIP Call pursuant to the CAA to require twenty-two
states and the District of Columbia to reduce NOX, a
precursor to ozone and PM2.5 pollution, and providing a
mechanism (the NOX Budget Trading Program) that states could
use to achieve those reductions. Affected states were required to
comply with Phase I of the SIP Call beginning in 2004, and Phase II
beginning in 2007. By the end of 2008, ozone season NOX
emissions from sources subject to the NOX SIP Call dropped
by sixty-two percent from 2000 emissions levels. All NOX SIP
Call states have SIPs that currently satisfy their obligations under
the NOX SIP Call, and the emission reductions required under
the SIP Call are permanent and enforceable.
    As part of the NOX SIP Call, the eastern third of
Missouri was required to comply with Phase II of the program. In
response, Missouri developed rules governing the control of
NOX emissions from EGUs, major non-EGU industrial boilers,
major cement kilns, and large internal combustion engines. EPA approved
Missouri's Phase II NOX SIP Call rules on August 15, 2006
(71 FR 46860). Implementation of the Phase II rules was projected to
result in an eighty-two percent NOX reduction from 1995
levels. Missouri rules which address the NOX SIP call
include:

     10 CSR 10-6.350, ``Emissions limitations and Emissions
Trading of Oxides of Nitrogen''
     10 CSR 10-6.360, ``Controlling NOX Emissions From Electric
Generating Units and Non-Electric Generating Boilers''
     10 CSR 10-6.380, ``Control of NOX Emissions From Portland
Cement Kilns''
     10 CSR 10-6.390, ``Control of NOX Emissions From Large
Stationary Internal Combustion Engines''
    Clean Air Interstate Rule (CAIR) and the Cross State Air Pollution
Rule (CSAPR). The Clean Air Interstate Rule (CAIR) was promulgated in
2005 and required twenty-eight eastern states and the District of
Columbia to significantly reduce emissions of SO2 and
NOX from electric generating units (EGUs) in order to limit
the interstate transport of these pollutants and the ozone and fine
particulate matter these pollutants form in the atmosphere. 70 FR 25162
(May 12, 2005). In 2008, the D.C. Circuit initially vacated CAIR and
ordered EPA to replace CAIR in its entirety, North Carolina v. EPA, 531
F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule to EPA
without vacatur in order to preserve the environmental benefits
provided by CAIR, North Carolina v. EPA, 550 F.3d 1176, 1178 (D.C. Cir.
2008). On August 8, 2011, acting on the Court's remand, EPA promulgated
CSAPR in order to replace CAIR and address interstate transport of
emissions and the resulting secondary formation of ozone and fine
particulate matter (76 FR 48208).\9\ CSAPR requires substantial
reductions of SO2 and NOX emissions from EGUs in
twenty-eight states in the eastern United States. As a general matter,
because CSAPR is CAIR's replacement, emissions reductions associated
with CAIR will for most areas be made permanent and enforceable through
implementation of CSAPR.
---------------------------------------------------------------------------

    \9\ CAIR addressed the 1997 PM2.5 annual standard and
the 1997 8-hour ozone standard. CSAPR addresses contributions from
upwind states to downwind nonattainment and maintenance of the 2006
24-hour PM2.5 standard as well as the ozone and
PM2.5 NAAQS addressed by CAIR.
---------------------------------------------------------------------------

    Implementation of the rule was scheduled to begin on January 1,
2012, when CSAPR's cap-and-trade programs would have superseded the
CAIR cap-and-trade programs. Numerous parties filed petitions for
review of CSAPR in the D.C. Circuit and on August 21, 2012,

the court issued its ruling vacating and remanding CSAPR to EPA and
ordering continued implementation of CAIR. EME Homer City Generation,
L.P. v. EPA, 696 F.3d 7, 38 (D.C. Cir. 2012). The D.C. Circuit's
vacatur of CSAPR was reversed by the United States Supreme Court on
April 29, 2014, and the case was remanded to the D.C. Circuit to
resolve remaining issues in accordance with the Supreme Court's ruling.
EPA v. EME Homer City Generation, L.P., 134 S. Ct. 1584 (2014). On
remand, the D.C. Circuit affirmed CSAPR in most respects, but
invalidated without vacating some of the CSAPR budgets as to a number
of states. EME Homer City Generation, L.P. v. EPA, 795 F.3d 118. (D.C.
Cir. 2015) (EME Homer City II). The CSAPR budgets for Missouri are not
affected by the Court's decision. The litigation over CSAPR ultimately
delayed implementation of that rule for three years, from January 1,
2012, when CSAPR's cap-and-trade programs were originally scheduled to
replace the CAIR cap-and-trade programs, to January 1, 2015. Thus, the
rule's Phase 2 budgets were originally promulgated to begin on January
1, 2014, but began on January 1, 2017.
    As noted above, CAIR was promulgated in 2005 and incentivized early
reductions from sources in all covered states, including those upwind
of the St. Louis area. On December, 14, 2007, EPA approved Missouri's
CAIR rules into the SIP and the state's CAIR rules became effective in
2009 (72 FR 71073). The Missouri rule written to comply with the
NOX SIP Call requirements for EGUs was replaced with the
CAIR NOX regulations, 10 CSR 10-6.362, Clean Air Interstate
Rule Annual NOX Trading program and 10 CSR 10-6.364, Clean Air
Interstate Rule Seasonal NOX Trading program, and include limits for
non-EGU boilers, specifically Trigen Units 5 and 6 and Anheuser Busch
Unit 6. However, these three units have all been retired, and received
retired unit exemptions that prohibit these units from operating.
    Missouri's SIP redesignation request lists CAIR as a control
measure. CAIR was in effect and achieving emission reductions in
Missouri when the St. Louis area began monitoring attainment of the
1997 annual PM2.5 NAAQS. The quality-assured, certified
monitoring data used to demonstrate the area's attainment of the 1997
annual PM2.5 NAAQS by the April 5, 2010, attainment deadline
was influenced by reductions achieved by CAIR. Furthermore, because
PM2.5 concentrations in the St. Louis area are likely
impacted by the transport SO2 and NOX emissions
produced upwind, the area's air quality is likely affected by
regulation of emissions from power plants in other states.
    On November 21, 2014, the Administrator signed an action that
published in the Federal Register on December 3, 2014 (79 FR 71163),
amending the regulatory text of CSAPR to reflect the Court's October
23, 2014, order tolling all deadlines in CSAPR by three years,
including provisions governing the sunsetting of CAIR. CAIR therefore
sunset at the end of 2014 and was replaced by CSAPR beginning January
1, 2015, which continue to remain in place. Relative to CAIR, CSAPR
required similar or greater emission reductions from relevant upwind
areas starting in 2015 and beyond, and Missouri's emissions budgets
were not affected by the Court's remand of some of the ozone-season and
SO2 budgets. The emission reductions associated with CAIR
that helped the St. Louis area achieve attainment of the 1997 annual
PM2.5 NAAQS can therefore be considered permanent and
enforceable for purposes of redesignation under section
107(d)(3)(E)(iii) of the CAA.
    State and Local Measures. In addition to the above Federal
measures, Missouri has several other state regulations that provide
permanent and enforceable controls for PM2.5 and
PM2.5 precursor emissions in the St. Louis area. These SIP
approved rules include:
     10 CSR 10-6.405 ``Restriction of Particulate Matter
Emissions from Fuel Burning Equipment Used for Indirect Heating''
     10 CSR 10-5.040 ``Use of Fuel in Hand-Fired Equipment
Prohibited''
     10 CSR 10-5.070 ``Open Burning Restrictions''
     10 CSR 10-6.170 ``Restriction of Particulate Matter to the
Ambient Air Beyond the Premises of Origin''
     10 CSR 10-6.220 ``Restriction of Emission of Visible Air
Contaminants''
     10 CSR 10-6.260 ``Restriction of Emission of Sulfur
Compounds''
     10 CSR 10-6.330 ``Restriction of Emissions from Batch-Type
Charcoal Kilns''
     10 CSR 10-6.400 ``Restriction of Emission of Particulate
Matter from Industrial Processes''
    Vehicle Inspection and Maintenance Program. To meet nonattainment
area requirements for the one-hour ozone standard, Missouri implemented
an inspection and maintenance program beginning in 2000 in the counties
of St. Louis, St. Charles, and Jefferson and the City of St. Louis.
Missouri codified the program through state rule 10 CSR 10-5.380,
``Motor Vehicle Emissions Inspection,'' and EPA approved an additional
revision this rule on May 12, 2003 (68 FR 25414). While this program
was established to address ozone formation, the reduction in
NOX emissions impact PM2.5 in this area. The
mobile source emissions inventory projections used in this
demonstration incorporates the inspection and maintenance program rule,
10 CSR 10-5.381, which replaced the 10-5.380 rule. The state has
implemented 10 CSR 10-5.381 since 2007 and EPA approved this rule in 80
FR 11323, March 3, 2015.
    Permanent and Enforceable Controls Used to Attain the Standard for
the Illinois portion of the nonattainment area. The same Federal
control measures listed above for the Missouri side of the area are
also applicable to the Illinois side of the St. Louis area (defined as
Madison, Monroe, and St. Clair Counties as well as the Baldwin Township
of Randolph County). These include the Federal mobile source measures
and Federal upwind trading programs. Illinois also operates an
Inspection/Maintenance (I/M) program, and has adopted a state rule to
control NOX and SO2 from EGUs. Illinois also has
a number of other state regulations in place to control
PM2.5 and PM2.5 precursors. Additional
information regarding NOX and VOC emissions controls for the
Illinois portion of the area can be found in the Illinois maintenance
plan for the nonattainment area under the 1997 ozone standard. See
docket ID EPA-R05-OAR-2010-0523; FRL-9619-8 for more information.
b. Emission Reductions
    The St. Louis area attained the 1997 annual PM2.5 NAAQS
based on monitoring data for the three-year period from 2007-2009.
During the development of the nonattainment SIP, which was subsequently
withdrawn by the state, MDNR selected 2002 as the baseyear and since
then has selected 2008 as the attainment emission inventory year. The
attainment inventory identifies a level of emissions in the area that
is sufficient to attain the 1997 annual PM2.5 NAAQS for
direct PM2.5 and the PM2.5 precursors
SO2, NOX, NH3 and VOC. Point source
information was compiled from the 2008 NEI and the annual emissions
reports submitted to MDNR by sources and EPA's Clean Air Markets
Division database for electric utilities. Area, nonroad and onroad
attainment year inventories originated from the 2008 NEI v1.5 provided
by EPA. For more information on EPA's analysis of the 2002 and 2008
emissions inventories, see EPA's ``Emissions Inventory and Motor
Vehicle Emissions Budget (MVEB) Technical Support Document

(TSD) for the Redesignation Request and Maintenance Plan for the St
Louis, Missouri 1997 PM2.5 Nonattainment Area,'' or appendix
B, E and F of the state submittal, available on line at
www.regulations.gov, Docket ID No. EPA-R07-OAR-2017-0734.
    Using the inventory described above, as well as emissions
inventories provided by Illinois, Missouri has documented changes in
emissions from 2002 NEI to 2008 for the St. Louis area as shown in
table 3 below. This table demonstrates that the entire St. Louis area
has reduced emissions during the period except as described below.

                            Table 3--Comparison of 2002 NEI and 2008 Baseyear Inventory for the St. Louis Nonattainment Area
                                                                          [tpy]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                County name                        Source category              NH3             NOX          PM2.5-Pri          SO2             VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Point Sources...............           -7.11      -13,095.20       -1,113.84      +44,701.42       -6,569.97
Illinois..................................  ............................          164.12      -17,471.79         +134.22       -3,811.29         -816.76
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................          157.01      -30,566.99         -979.62      +40,890.13       -7,386.76
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Area Sources................         -453.09       -5,546.29         -799.57       -5,721.41       -7,169.82
Illinois..................................  ............................         -433.02       -1,967.73       -2,757.16         -141.18      -16,890.58
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................         -886.11       -7,514.02       -3,556.73       -5,862.59      -24,060.40
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  On-Road Mobile Sources......         -177.76      -31,503.01         -631.79       -1,452.91      -18,830.40
Illinois..................................  ............................            6.88       -4,646.94         -102.62         -556.81       -2,555.87
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................         -170.88      -36,149.95         -734.41       -2,009.72      -21,386.27
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Off-Road Mobile Sources.....           +5.84       -6,714.58         -386.84       -1,531.01       -3,962.38
Illinois..................................  ............................           -1.24       +1,063.95          +33.13          -93.56          131.75
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           +4.60       -5,650.63         -353.71       -1,624.57       -3,830.63
--------------------------------------------------------------------------------------------------------------------------------------------------------
        Missouri Totals...................  ............................         -632.13      -56,859.08       -2,932.04      +35,996.09      -36,532.57
                                                                         -------------------------------------------------------------------------------
        Illinois Totals...................  ............................         -263.26      -23,022.51       -2,692.43       -4,602.84      -20,131.46
                                                                         -------------------------------------------------------------------------------
            Grand Total...................  ............................         -895.39      -79,881.59       -5,624.47      +31,393.25      -56,664.03
--------------------------------------------------------------------------------------------------------------------------------------------------------

    There is an increase of total SO2 emissions from 2002 to
2008 of 35,996.09 tons on the Missouri side of the nonattainment area.
This increase is a result of two factors described below. First, over
20,700 tons of the SO2 increase can be attributed to a
change in emission factors between 2002 and 2008 for the Doe Run
Primary Lead Smelter in Herculaneum, MO, but that source has since shut
down.\10\ The second factor which contributes to the increase in
SO2 emissions is a ten percent increase in electricity
demand at four Missouri EGUs. Between 2002 and 2008 a 10 percent
increase in electricity demand coupled with increases in SO2
emission rates from the Ameren utilities lead to increasing
SO2 emissions between 2002 and 2008. Overall emissions from
2002 to 2008 are trending down for direct PM2.5 and the
three other PM2.5 precursors and EPA believes that the
effect of these decreases cumulatively outweigh the increase seen in
SO2 emissions during the same time, thus supporting EPA's
position set forth in this ANPR. In addition, in the years following
2008, substantial SO2 reductions have been realized in the
St. Louis utility sector within the nonattainment area from a
combination of controls, fuel switching and shutdowns, and EPA believes
SO2 emissions from the utility sector will not increase back
to 2002 or 2008 levels further supporting EPA's position in this ANPR.
---------------------------------------------------------------------------

    \10\ This facility shut down in 2011 pursuant to a federally
enforceable Consent Decree. https://www.epa.gov/enforcement/doe-run-resources-corporation-settlement.
---------------------------------------------------------------------------

    Based on the information summarized above, and information provided
in the technical support, which is a part of the docket for this
action, EPA is providing advanced notice of its determination that
Missouri has adequately demonstrated that the improvement in air
quality is due to permanent and enforceable emissions reductions.

Criteria (4)--The Area Has a Fully Approved Maintenance Plan Pursuant
to Section 175A of the CAA (Section 107(d)(3)(E)(iv))

    In conjunction with its request to redesignate the St. Louis area
to attainment for the 1997 annual PM2.5 NAAQS, MDNR
submitted a SIP revision on September 1, 2011, supplemented on March
31, 2014, and further clarified on September 17, 2014, to provide for
the maintenance of the 1997 annual PM2.5 NAAQS for at least
ten years after the effective date of redesignation to attainment. EPA
is providing advanced notice that it believes this maintenance plan
meets the requirements for approval under section 175A of the CAA.
a. Maintenance Plan Requirements
    Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
Under section 175A, the plan must demonstrate continued attainment of
the applicable NAAQS for at least ten years after the Administrator
approves a redesignation to attainment. Because the 1997 p.m.2.5 NAAQS
will be revoked for the area if the area is redesignated to attainment,
Missouri is not required submit a revised maintenance plan eight years
after the redesignation. To address the possibility of future NAAQS
violations, the maintenance plan must contain such contingency
measures, as EPA deems necessary, to assure prompt correction of any
future 1997 annual PM2.5 NAAQS violations. The Calcagni
Memorandum provides further guidance on the content of a maintenance
plan, explaining that a maintenance plan

should address five requirements: (1) The attainment emissions
inventory, (2) a maintenance demonstration, (3) a commitment to
maintain the existing monitoring network, (4) verification of continued
attainment, and (5) a contingency plan to plan or prevent or correct
future violations. As discussed below, EPA is proposing that MDNR's
maintenance plan includes all the necessary components and is thus
proposing to approve it as a revision to the Missouri SIP.
b. Maintenance Plan Base Year Inventory
    As discussed previously, the 2008 inventory is referenced as the
baseyear and is used for the year of attainment is called the
Attainment Year Inventory. The 2008 inventory is the inventory which
all future years will be compared to in order to show maintenance.
However, MDNR created a different 2008 onroad inventory for the
comparison to future years in the maintenance plan. As explained
previously, for the 2008 onroad attainment inventory, MDNR used NEI
data which was developed using Mobile6.2 to compare with the 2002
nonattainment base year. A second 2008 onroad inventory was developed
utilizing MOVES2010 to establish a maintenance base year for comparison
to the future 2017 and 2025 MOVES-based future year inventories. This
allows for a smooth transition to the updated model and to prevent
comparing a MOVES2010 version of 2008 attainment year with the
Mobile6.2 version of the 2002 nonattainment base year inventory.
Therefore, the 2008 onroad mobile source inventory used for supporting
maintenance was developed using the most current version of EPA's
highway mobile source emissions model, MOVES2010a.
    Emissions projections to support maintenance through 2025 have been
prepared for the years 2017 and 2025. While Missouri's maintenance plan
projects maintenance of the 1997 Annual PM2.5 NAAQS through
2025, as noted above, EPA believes that the St. Louis area will
continue to maintain the standard through 2027 for several reasons: All
of the Federal regulatory requirements that enabled the area to attain
the NAAQS will continue to be in effect and enforceable after the ten-
year maintenance period. Overall emissions are projected to decline
steadily through 2025. Because it is unlikely that emissions will
suddenly increase in 2026 and 2027 in an amount that results in overall
emissions in the area exceeding an attainment year inventory levels.
EPA expects that the St. Louis area will continue to maintain the 1997
Annual PM2.5 NAAQS through 2027.
    EPA has reviewed the documentation provided by MDNR and is
providing advanced notice that the EPA believes the emissions inventory
is acceptable. For more information on EPA's analysis of the 2008
emissions inventory, see EPA's TSD as part of this advanced notice of
proposed rulemaking, or Appendix B, E and F of the state's 2014
submittal and additional clarifying information provided on September
17, 2014, available on line at www.regulations.gov, Docket ID No. EPA-
R07-OAR-2017-0734.
c. Maintenance Demonstration
    Section 175A requires a state seeking redesignation to attainment
to submit a SIP revision to provide for the maintenance of the NAAQS in
the Area ``for at least ten years after the redesignation.'' EPA has
interpreted this as a showing of maintenance ``for a period of ten
years following redesignation.'' Calcagni Memorandum, p. 9. Where the
emissions inventory method of showing maintenance is used, the purpose
is to show that emissions during the maintenance period will not
increase over the attainment year inventory. Calcagni Memorandum, pp.
9-10.
    As discussed in detail in the subsection below, Missouri's
maintenance plan submission expressly documents that the area's
emissions inventories will remain below the attainment year inventories
through 2025. For a demonstration of maintenance, emissions inventories
are required to be projected to future dates to assess the influence of
future growth and controls; however, the maintenance demonstration need
not be based on air quality modeling. See Wall v. EPA, 265 F.3d 426
(6th Cir.2001); Sierra Club v. EPA, 375 F. 3d 537 [(7th Cir.2004)]. See
also 66 FR 53099-66 FR 53100; 68 FR 25430-68 FR 25432. MDNR uses
projection inventories to show that the Missouri portion of the St.
Louis area will remain in attainment. MDNR developed projection
inventories for an interim year of 2017 and a maintenance plan end year
of 2025 to show that future emissions of direct PM2.5,
NOX, SO2, NH3 and VOC will remain at
or below the attainment year 2008 emissions levels in the St. Louis
area through the year 2025. In light of more recent information on
CSAPR, Missouri submitted on September 17, 2014, a revision that
updated their future year projections for EGU facilities using the
presumption that CSAPR will be in place to control emissions from
sources. Non-EGU Point source and nonpoint sources were developed using
growth factors created from the EGAS model (https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations) using economic
growth projections from the Policy Insight[supreg] Model for Regional
Economic Model, Inc. (REMI) to project the future year inventory. EPA's
Nonroad Model and EPA's onroad mobile model, MOVES, were utilized to
project mobile source future inventories.
    EPA has reviewed the documentation provided by MDNR and is
providing advanced notice that it finds the methodologies acceptable.
Table 4-6 below shows the inventory summaries for the 2008 attainment
year, 2017 interim year, and the 2025 maintenance plan end year for the
entire area.

                                                        Table 4--2008 Emissions Inventory Summary
                                                                          [tpy]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   State                           Source category              NH3             NOX          PM2.5-Pri          SO2             VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Point Sources...............        1,308.64       31,103.26        3,493.39      201,700.73        5,067.89
Illinois..................................  ............................          208.31       16,981.51        2,448.15       21,853.56        4,277.72
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        1,516.95       48,084.77        5,941.54      252,431.33        9,345.61
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Area Sources................        3,514.98        4,382.94       14,033.64       11,510.48       38,215.34
Illinois..................................  ............................        3,354.13        1,638.36        5,161.76          246.67        7,796.34
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        6,869.11        6,021.30       19,195.40       11,757.15       46,011.68
--------------------------------------------------------------------------------------------------------------------------------------------------------

Missouri..................................  On-Road Mobile Sources......        1,056.17       58,819.58        2,179.28          426.65       23,793.80
Illinois..................................  ............................          250.58       15,012.94          577.99          116.76        5,069.55
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        1,306.75       73,832.52        2,757.27          543.41       28,863.35
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Off-Road Mobile Sources.....           15.68       20,722.57        1,199.82           544.3       11,545.53
Illinois..................................  ............................            2.89        8,475.24          425.71          300.72        2,972.77
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           18.57       29,197.81        1,625.53          845.02       14,518.30
                                                                         -------------------------------------------------------------------------------
        Grand Total.......................  ............................        9,711.38      157,136.40       29,515.74      265,576.91       98,738.94
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                        Table 5--2017 Emissions Inventory Summary
                                                                          [tpy]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   State                           Source category              NH3             NOX          PM2.5-Pri          SO2             VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Point Sources...............        1,308.64       31,661.08        3,692.74      107,713.00        6,363.13
Illinois..................................  ............................          221.12       11,891.31        2,601.95       20,221.18        4,962.34
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        1,529.76       43,552.39        6,294.69      127,934.18       11,325.47
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Area Sources................        3,514.98        4,446.97       14,165.78       11,534.82       44,057.17
Illinois..................................  ............................        3,364.32        1,694.82        4,706.63          258.36        8,607.70
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        6,879.30        6,141.79       18,872.41       11,793.18       52,664.87
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  On-Road Mobile Sources......          722.47       22,904.99          913.15          191.12       10,867.41
Illinois..................................  ............................          186.79        5,623.42          231.68           49.31        2,364.85
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................          909.26       28,528.41        1,144.83          240.43       13,232.26
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Off-Road Mobile Sources.....           15.75       10,505.88          787.35          193.55        7,398.02
Illinois..................................  ............................            3.46        8,673.75          370.28          390.79        2,303.43
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           19.21       19,179.63        1,157.63          584.34        9,701.45
                                                                         -------------------------------------------------------------------------------
        Grand Total.......................  ............................        9,337.53       97,402.22       27,469.56      140,552.13       86,924.05
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                        Table 6--2025 Emissions Inventory Summary
                                                                          [tpy]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   State                           Source category              NH3             NOX          PM2.5-Pri          SO2             VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Point Sources...............        1,308.64       32,603.86        4,403.28      108,617.07        7,809.01
Illinois..................................  ............................          242.69       12,822.94        2,865.19       21,853.56        5,541.80
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        1,551.33       45,426.80        7,268.47      130,470.63       13,350.81
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Area Sources................        3,514.98        4,531.02       14,314.86       11,606.89       49,458.63
Illinois..................................  ............................        3,374.17        1,735.20        4,668.15          268.04        9,249.75
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................        6,889.15        6,266.22       18,983.01       11,874.93       58,708.38
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  On-Road Mobile Sources......          691.88       16,568.44          533.34          189.22        8,035.80
Illinois..................................  ............................          178.80        3,616.52          181.73           49.15        1,592.92
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................          870.68       20,184.96          715.07          238.37        9,628.72
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Off-Road Mobile Sources.....           17.63        8,895.81          640.68           219.9        7,178.29
Illinois..................................  ............................            3.99        9,028.03           331.2          438.02        2,037.10
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           21.62       17,923.84          971.88          657.92        9,215.39
                                                                         -------------------------------------------------------------------------------
        Grand Total.......................  ............................        9,332.78       89,801.82       27,938.43      143,241.85       90,903.30
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 7 below compares the 2008 base year to the 2025 projection
year and shows that the St. Louis area is projected to reduce
SO2 emissions by 122,335 tpy, NOX emissions by
67,335 tpy, direct PM2.5 emissions by 1,577 tpy,
NH3 emissions by 379 tpy, and VOC emissions by 7,836 tpy.

                                             Table 7--Comparison of 2008 Base Year and 2025 Projection Year
                                                                          [tpy]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   State                           Source category              NH3             NOX          PM2.5-Pri          SO2             VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Point Sources...............            0.00       +1,500.60         +909.89      -93,083.66       +2,741.12
Illinois..................................  ............................           34.38       -4,158.57         +417.04      -28,877.04       +1,264.08
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           34.38       -2,657.97        1,326.93     -121,960.70       +4,005.20
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Area Sources................            0.00         +148.08         +281.22          +96.41      +11,243.29
Illinois..................................  ............................           20.04          +96.84         -493.61          +21.37       +1,453.41
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           20.04          244.92         -212.39          117.78      +12,696.70
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  On-Road Mobile Sources......         -364.29      -42,251.14       -1,645.94         -237.43      -15,758.00
Illinois..................................  ............................          -71.78      -11,396.42         -396.26          -67.61       -3,476.63
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................         -436.07      -53,647.56       -2,042.20         -305.04      -19,234.63
--------------------------------------------------------------------------------------------------------------------------------------------------------
Missouri..................................  Off-Road Mobile Sources.....            1.95      -11,826.76         -559.14         -324.40       -4,367.24
Illinois..................................  ............................            1.10         +552.79          -94.51         +137.30         -935.67
                                                                         -------------------------------------------------------------------------------
    Totals................................  ............................           +3.05      -11,273.97         -653.65         -187.10       -5,302.91
--------------------------------------------------------------------------------------------------------------------------------------------------------
        Missouri Totals (Safety Margin)...  ............................         -362.34      -52,429.22       -1,013.97      -93,549.08       -6,140.83
                                                                         -------------------------------------------------------------------------------
        Illinois Totals (Safety Margin)...  ............................          -16.26      -14,905.36         -567.34      -28,785.98       -1,694.81
                                                                         -------------------------------------------------------------------------------
            Grand Total...................  ............................         -378.60      -67,334.58       -1,577.31     -122,335.06       -7,835.64
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Note: A negative value indicates a projected decrease in emissions from 2008 to 2025. A positive value indicates a projected increase in emissions
  from 2008 to 2025.

    Table 5-4 of Missouri's September 17, 2014 submittal shows that in
the 2017 interim year, emissions levels in the area will remain below
the 2008 base year for all pollutant categories.
    While MDNR's maintenance plan projects maintenance of the 1997
Annual PM2.5 NAAQS through 2025, as noted above, EPA is
providing advanced notice that it expects St. Louis Area will continue
to maintain the standard through 2028 for several reasons: All of the
Federal regulatory requirements that enabled the Area to attain the
NAAQS will continue to be in effect and enforceable after the ten-year
maintenance period and overall emissions are projected to decline
significantly through 2025. Again, because there is no indication that
emissions will suddenly increase in 2026, 2027 and 2028 in an amount
that results in overall emissions in the area exceeding attainment year
inventory levels, EPA is providing advanced notice that it expects that
the St. Louis Area will continue to maintain the 1997 Annual
PM2.5 NAAQS through 2028.
d. Monitoring Network
    There are currently 6 monitors measuring PM2.5 in the
Missouri portion of the St. Louis area.\11\ MDNR has committed to
continue operation of the network in the area in compliance with 40 CFR
part 58 and have thus addressed the requirement for monitoring. EPA
approved Missouri's 2016 monitoring plan on December 29, 2016, see
https://www.epa.gov/ks/region-7-air-quality-program.
---------------------------------------------------------------------------

    \11\ One monitor in the Missouri portion of the St. Louis area
is a middle scale monitor and is not comparable to the 1997
PM2.5 Annual NAAQS.
---------------------------------------------------------------------------

e. Verification of Continued Attainment
    MDNR has the legal authority to enforce and implement the
requirements of the Missouri portion of the St. Louis area 1997 annual
PM2.5 NAAQS maintenance plan. This includes the authority to
adopt, implement and enforce any subsequent emissions control
contingency measures determined to be necessary to correct future
PM2.5 attainment problems.
    MDNR will track the progress of the maintenance plan by performing
future reviews of triennial emission inventories for the St. Louis area
as required in the Air Emissions Reporting Rule (AERR). For these
periodic inventories, MDNR will review the assumptions made for the
purpose of the maintenance demonstration concerning projected growth of
activity levels.
f. Contingency Measures in the Maintenance Plan.
    Section 175A of the CAA requires that a maintenance plan include
such contingency measures as EPA deems necessary to assure that the
state will promptly correct a violation of the NAAQS that occurs after
redesignation. The maintenance plan should identify the contingency
measures to be adopted, a schedule and procedure for adoption and
implementation, and a time limit for action by the state. A state
should also identify specific indicators to be used to determine when
the contingency measures need to be implemented. The maintenance plan
must include a requirement that a state will implement all measures
with respect to control of the pollutant that were contained in the SIP
before redesignation of the area to attainment in accordance with
section 175A(d).
    The contingency plan included in the submittal includes a
triggering mechanism to determine when contingency measures are needed
and a

process of developing and implementing appropriate control measures.
MDNR will use actual ambient monitoring data as the triggering event to
determine when contingency measures should be implemented.
    Missouri has identified two different levels of corrective
responses should the annual PM2.5 level exceed the NAAQS in
any year. A level I trigger occurs when the annual average monitored
PM2.5 concentration exceeds 15.0 [mu]g/m\3\ in any year at
any monitoring station in the nonattainment area as described in the
state's submittal for the St. Louis area.
    MDNR will evaluate a level I condition, if it occurs, as
expeditiously as practicable to determine the causes of the ambient
PM2.5 increase. If adverse emission trends are likely to
continue, MDNR will first evaluate and subsequently adopt and implement
control measures, taking into consideration the ease of implementation
and the technical and economic feasibility of selected measures, as
outlined in the state's plan no later than twenty-four months after
quality-assured ambient data has been entered into EPA's Air Quality
System (AQS) database indicating a level I trigger.
    A level II trigger is activated when any violation of the 1997
annual PM2.5 NAAQS at any Federal reference method monitor
in the St. Louis maintenance area is recorded, based on quality-assured
monitoring data. In this event, MDNR will conduct a comprehensive study
to determine the cause of the violation within six months of the
triggering event. Selected measures will be implemented as
expeditiously as practicable, taking into consideration the ease of
implementation and the technical and economic feasibility of selected
measures, as outlined in the state's plan no later than twenty-four
months after quality-assured ambient data has been entered into EPA's
AQS database indicating a level II trigger.
    The comprehensive measures will be selected from the following
types of measures, as further detailed in the state's submission, or
from any other measure deemed appropriate and effective at the time the
selection is made by MDNR:
     Controls for local individual sources with significant
effects on the monitored violation;
     Revisions to current rules that control PM2.5
and PM2.5 precursor emissions such as lowering limits and
broadening applicability thresholds of current rules; and
     Establishing new rules that control PM2.5 and
PM2.5 precursor emissions.
    In addition to the triggers indicated above, Missouri commits to
compiling and monitoring PM2.5 and PM2.5
precursor emissions inventories for the Missouri portion of the area
every three years throughout the duration of the maintenance period to
facilitate the emissions trends analysis included in the contingency
plan under levels I and II.
    EPA is providing advanced notice of its analysis that that the
maintenance plan adequately addresses the five basic components of a
maintenance plan: Attainment emission inventory, maintenance
demonstration, monitoring network, verification of continued
attainment, and a contingency plan. Therefore, EPA is providing
advanced notice that it in a future action, it intends to find that the
maintenance plan SIP revision submitted by MDNR for the Missouri
portion of the St. Louis area meets the requirements of section 175A of
the CAA and is approvable.
    In addition, EPA is providing advanced notice that it intends to
determine that the state submission has met the public notice
requirements for SIP submissions in accordance with 40 CFR 51.102. The
submission also satisfied the completeness criteria of 40 CFR part 51,
appendix V. As explained above and in more detail in the technical
support document which is part of this document, the revision meets the
substantive SIP requirements of the CAA, including section 110 and
implementing regulations.

V. What is EPA's initial analysis of the state's MVEBs?

    Under section 176(c) of the CAA, new transportation plans,
programs, and projects, such as the construction of new highways, must
``conform'' to (i.e., be consistent with) the part of the state's air
quality plan that addresses pollution from cars and trucks. Conformity
to the SIP means that transportation activities will not cause new air
quality violations, worsen existing violations, or delay timely
attainment of the NAAQS or any interim milestones. If a transportation
plan does not conform, most new projects that would expand the capacity
of roadways cannot go forward. Regulations at 40 CFR part 93 set forth
EPA policy, criteria, and procedures for demonstrating and assuring
conformity of such transportation activities to a SIP. The regional
emissions analysis is one, but not the only, requirement for
implementing transportation conformity. Transportation conformity is a
requirement for nonattainment and maintenance areas. Maintenance areas
are areas that were previously nonattainment for a particular NAAQS but
have since been redesignated to attainment with an approved CAA section
175A maintenance plan for that NAAQS.
    Under the CAA, states are required to submit at various times,
control strategy SIPs and maintenance plans for nonattainment areas.
These control strategy SIPs (including RFP and attainment
demonstration) and maintenance plans create MVEBs for criteria
pollutants and/or their precursors to address pollution from cars and
trucks. Per 40 CFR part 93, a MVEB must be established for the last
year of the maintenance plan. A state may adopt MVEBs for other years
as well. A MVEB is the portion of the total allowable emissions in the
maintenance demonstration that is allocated to highway and transit
vehicle use and emissions. See 40 CFR 93.101. The MVEBs serve as a
ceiling on emissions from an area's planned transportation system. The
MVEBs concept is further explained in the preamble to the November 24,
1993, Transportation Conformity Rule. See 58 FR 62188. The preamble
also describes how to establish the MVEBs in the SIP and how to revise
the MVEBs.
    After interagency consultation with the transportation partners for
the St. Louis area, Missouri developed MVEBs for NOX and
PM2.5 for the Missouri portion of the St. Louis
nonattainment area. Missouri has developed these MVEBs for 2008 and
2025. The MVEBs reflect the total on-road emissions for 2008 and 2025,
plus an allocation from the available NOX and
PM2.5 safety margin. Under 40 CFR 93.101, the term ``safety
margin'' is the difference between the attainment level (from all
sources) and the projected level of emissions (from all sources) in the
maintenance plan. All or a portion of the safety margin can be
allocated to the transportation sector; however, the total emissions
from all sources must remain below the attainment level (40 CFR
93.124(a)). The NOX and PM2.5 MVEBs and
allocation from the safety margin were developed in consultation with
the transportation partners and were added to account for uncertainties
in population growth, changes in modeled vehicle miles traveled, and
new emission factor models. The NOX and PM2.5
MVEBs for the Missouri portion of the St. Louis area are identified in
Table 9, below.

 Table 8--Missouri Portion of the St. Louis Area PM2.5 and NOX 2008 and
                               2025 MVEBs
                                  [tpy]
------------------------------------------------------------------------
                                                        PM2.5      NOX
------------------------------------------------------------------------
2008 Motor Vehicle Emissions Budgets................     2,179    58,820
2025 Mobile Emissions...............................       533    16,568
2025 Safety Margin Allocated (20%)..................       107     3,314
2025 Motor Vehicle Emissions Budgets................       640    19,882
------------------------------------------------------------------------

    In an effort to accommodate future variations in travel demand
models (TDM) results and the vehicle miles traveled forecast when no
change to the network is planned, MDNR consulted with the interagency
consultation group, including U.S. EPA Region 7, to determine a
reasonable approach to address this variation. The projected 2025
annual on-road motor vehicle emissions for direct PM2.5 and
NOX are 533 and 16,568 tons, respectively.
    A safety margin is necessary to accommodate the variability, or
worst-case scenarios that can occur due to future planning assumptions.
The Missouri portion of the St. Louis area's available total safety
margin for NOX is 52,429 and direct PM2.5 is
1,014. However, Missouri is only using a portion of this available
safety margin. The worst-case daily motor vehicle emissions projection
for PM2.5 is twenty percent above the projected 2025 on-road
emissions. For the PM2.5 MVEB, the needed annual safety
margin would be twenty percent above the projected 533 tons for 2025
onroad emissions. Therefore, the needed annual safety margin for
PM2.5 would be 107 tons resulting in an overall MVEB of 640
tons per year. The worst-case daily motor vehicle emissions projection
for NOX is twenty percent above the projected 16,568 tons
for 2025 on-road emissions. Therefore, the needed annual safety margin
for the NOX MVEB would be 3,314 tons, resulting in an
overall MVEB of 19,882 tons per year.
    The maintenance plan establishes 2008 and 2025 MVEBs for direct
PM2.5 and NOX for the St. Louis area. EPA is
providing advanced notice that in a future action it will initiate the
process for determining whether or not the MVEBs are adequate for
transportation conformity purposes. The publication of the future
notice starts a 30-day public comment period on the adequacy of the
submitted MVEBs. The comment period will be concurrent with the comment
period on of the future action and comments should be submitted to the
docket for that rulemaking. EPA may choose to make its determination on
the adequacy of the budgets either in the final rulemaking on this
maintenance plan and redesignation request or by informing the state of
the determination in writing, and publishing a notice in the Federal
Register. EPA will also update its adequacy web page to reflect the
decision on the adequacy of the budgets (https://www.epa.gov/state-and-local-transportation).\12\ EPA, through is providing advanced notice,
that it intends to propose to approve the MVEBs for use to determine
transportation conformity in the Missouri portion of the St. Louis
area. EPA has reviewed the budgets and the entire maintenance plan and
redesignation request. In conducting that review we applied the
adequacy criteria found in 40 CFR 93.118(e)(4) and found that the
budgets satisfy all of these criteria. For more information on EPA's
review, see EPA's ``Emissions Inventory and Motor Vehicle Emissions
Budget (MVEB) Technical Support Document (TSD) for the Redesignation
Request and Maintenance Plan for the St Louis, Missouri 1997
PM2.5 Nonattainment Area'' available on line at
www.regulations.gov, Docket ID No. EPA-OAR-R07-2017-0734.
---------------------------------------------------------------------------

    \12\ For additional information on the adequacy process, refer
to 40 CFR 93.118(f) and the discussion of the adequacy process in
the preamble to the 2004 final transportation conformity rule. (69
FR 40039-40043)
---------------------------------------------------------------------------

    As discussed throughout this notice EPA's review of the
redesignation request and maintenance plan for this area shows that the
area has attained the 1997 annual PM2.5 NAAQS and will
continue to maintain that NAAQS through 2028. While budgets were
submitted for 2008 and 2025, EPA is providing advanced notice that the
submitted motor vehicle emissions budgets for NOX and
PM2.5 for 2025 are consistent with maintenance of the 1997
annual PM2.5 NAAQS through at least 2028 for the reasons
discussed above.
    We are providing advanced notice that we intend to approve the
redesignation request, maintenance plan and the NOX and
PM2.5 budgets contained in the maintenance plan in a
subsequent action.

VI. What is EPA's initial analysis of the state's 2008 emissions
inventory?

    EPA has reviewed Missouri's documentation of the emissions
inventory techniques and data sources used for the derivation of the
2008 emissions estimates and has found that Missouri has thoroughly
documented the derivation of these emissions inventories. The submittal
from the state shows that at the time the 2008 emissions inventory was
the most complete emissions inventory for PM2.5 and
PM2.5 precursors in the St. Louis area. Based upon EPA's
review, we propose to find that 2008 emissions inventories are as
complete and accurate as possible given the input data available to
Missouri. Therefore, we are providing advanced notice and taking
comment on the 2008 NH3, VOC, NOX, direct
PM2.5 and SO2 emissions inventories as a base
year inventory. Final approval of the 2008 base year emissions
inventory will satisfy the emissions inventory requirement under
section 172(c)(3) of the CAA. For more information on EPA's analysis of
the 2008 base year emissions inventory, see EPA's ``Emissions Inventory
and Motor Vehicle Emissions Budget (MVEB) Technical Support Document
(TSD) for the Redesignation Request and Maintenance Plan for the St,
Louis, Missouri 1997 PM2.5 Nonattainment Area'' available on
line at www.regulations.gov, Docket ID No. EPA-OAR-R07-2017-0734.

VII. Summary of Advanced Notice of Proposed Actions

    EPA is providing advanced notice on several actions regarding the
area's redesignation and maintenance of the 1997 PM2.5
NAAQS. We are processing this as an advanced notice of proposed action
because we are soliciting comments on the information provided in this
notice and the appropriate of EPA's future action. First, EPA is giving
advanced notice that in a future action it intends to determine, based
on data for the 2015-2017 monitoring period, and after review of all
available data in AQS, that the Missouri portion of the St. Louis area
is attaining the 1997 annual PM2.5 NAAQS. EPA is also
providing advanced notice that it believes the St. Louis area has met
the criteria under CAA section 107(d)(3)(E) for redesignation from
nonattainment to attainment for the 1997 annual PM2.5 NAAQS.
Therefore, EPA is providing advanced notice and taking comment on
Missouri's request to redesignate the St. Louis area and change the
legal designation of Franklin, Jefferson, St. Charles, and St. Louis
and the City of St. Louis from nonattainment to attainment for the 1997
annual PM2.5 NAAQS.
    Second, EPA is providing advanced notice and taking comment on the
maintenance plan for the St. Louis area, including the PM2.5
and NOX MVEBs for 2008 and 2025 submitted by Missouri. The
maintenance plan demonstrates that the area will continue to maintain
the 1997 annual PM2.5 NAAQS, and the budgets meet all of the
adequacy criteria contained in 40 CFR 93.118(e)(4) and (5).

    In addition, EPA is providing advanced notice of proposed approval
of Missouri's 2008 base year emissions inventory in accordance with
section 172(c)(3) of the CAA. If finalized, approval of the
redesignation request would change the official designation of St.
Louis area for the 1997 annual PM2.5 NAAQS, found at 40 CFR
part 81, from nonattainment to attainment.

    Dated: December 15, 2017.
James B. Gulliford,
Regional Administrator, Region 7.
[FR Doc. 2018-00037 Filed 1-4-18; 8:45 am]
 BILLING CODE 6560-50-P