[Federal Register Volume 89, Number 188 (Friday, September 27, 2024)]
[Proposed Rules]
[Pages 79189-79195]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-22114]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R01-OAR-2024-0117; FRL-12283-01-R1]


Air Plan Approval; Connecticut; New Haven and Fairfield Counties 
Second 10-Year Limited Maintenance Plan for the 2006 24-Hour PM2.5 
Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve, under the Clean Air Act (CAA), the limited maintenance plan 
(LMP) for the 2006 PM<INF>2.5</INF> national ambient air quality 
standard (NAAQS) for New Haven and Fairfield Counties, which comprise 
the Connecticut portion of the New York-N. New Jersey-Long Island (NY-
NJ-CT) 2006 PM<INF>2.5</INF> NAAQS maintenance area. This LMP was 
submitted on May 9, 2023, and supplemented on February 21, 2024, by the 
Connecticut Department of Energy and Environmental Protection (CT 
DEEP). The plan addresses the second 10-year maintenance period for 
particulate matter with an aerodynamic diameter less than or equal to a 
nominal 2.5 micrometers, known as PM<INF>2.5</INF>. EPA is proposing 
approval of Connecticut's LMP submission because it provides for the 
maintenance of the 2006 24-hour PM<INF>2.5</INF> NAAQS through the end 
of the second 10-year portion of the maintenance period. In addition, 
EPA is initiating the process to find the Connecticut PM<INF>2.5</INF> 
LMP adequate for transportation conformity purposes.

DATES: Written comments must be received on or before October 28, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R01-
OAR-2024-0117 at https://www.regulations.gov, or via email to 
<a href="/cdn-cgi/l/email-protection#89e4e8fbfde0e7ece5e5e0a7e8f0e5e8c9eee4e8e0e5a7eae6e4"><span class="__cf_email__" data-cfemail="3954584b4d50575c5555501758405558795e54585055175a5654">[email protected]</span></a>. For comments submitted at Regulations.gov, 
follow the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, 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, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit https://www.epa.gov/dockets/commenting-epa-dockets. Publicly 
available docket materials are available at https://www.regulations.gov 
or at the U.S. Environmental Protection Agency, EPA Region 1 Regional 
Office, Air and Radiation Division, 5 Post Office Square--Suite 100, 
Boston, MA. EPA requests that, if possible, you contact the contact 
listed in the FOR FURTHER INFORMATION CONTACT section to schedule your 
inspection. The Regional Office's official hours of business are Monday 
through Friday, 8:30 a.m. to 4:30 p.m., excluding legal holidays and 
facility closures due to COVID-19.

FOR FURTHER INFORMATION CONTACT: Ayla Martinelli, Air Quality Branch, 
U.S. Environmental Protection Agency, EPA Region 1, 5 Post Office 
Square--Suite 100, (Mail code 5-MI), Boston, MA 02109-3912, tel. (617) 
918-1057, email <a href="/cdn-cgi/l/email-protection#2c414d5e58454249404045024d55404d6c495c4d024b435a"><span class="__cf_email__" data-cfemail="95f8f4e7e1fcfbf0f9f9fcbbf4ecf9f4d5f0e5f4bbf2fae3">[email protected]</span></a>.

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

Table of Contents

I. Background and Purpose
    A. The PM<INF>2.5</INF> National Ambient Air Quality Standards 
(NAAQS)
    B. Regulatory Actions in New Haven and Fairfield Counties
II. The Limited Maintenance Plan Option
    A. Demonstration of Maintenance Using the Limited Maintenance 
Plan Option
    B. Transportation Conformity Under Limited Maintenance Plan 
Option
    C. General Conformity Under Limited Maintenance Plan Option
III. EPA's Analysis of the State's Submittal
    A. Demonstration of Qualification for the Limited Maintenance 
Plan Option
    B. Attainment Inventory
    C. Air Quality Monitoring Network
    D. Verification of Continued Attainment
    E. Contingency Provisions
IV. Proposed Action
V. Statutory and Executive Order Reviews

I. Background and Purpose

A. The PM2.5 National Ambient Air Quality Standards (NAAQS)

    EPA has established NAAQS for particulate matter with an 
aerodynamic diameter less than or equal to 2.5 micrometers, known as 
PM<INF>2.5</INF>, to protect human health and the environment. In 1997, 
EPA established the first PM<INF>2.5</INF> standards based on 
significant scientific evidence and health studies demonstrating the 
serious health effects associated with exposure to PM<INF>2.5</INF>. 
EPA set an annual standard of 15.0 micrograms per cubic meter ([mu]g/
m\3\) and a 24-hour (or daily) standard of 65 [mu]g/m\3\. In 2006, EPA 
strengthened the 24-hour PM<INF>2.5</INF> NAAQS by revising it to 35 
[mu]g/m\3\ and retained the level of the annual PM<INF>2.5</INF> 
standard at 15.0 [mu]g/m\3\. Subsequently, in 2012, EPA established an 
annual primary PM<INF>2.5</INF> NAAQS at 12.0 [mu]g/m\3\ and retained 
the 2006 24-hour PM<INF>2.5</INF> NAAQS at 35 [mu]g/m\3\. In early 
2024, EPA strengthened the level of the annual primary PM<INF>2.5</INF> 
standard to 9.0 [mu]g/m\3\ and retained the 2006 24-hour 
PM<INF>2.5</INF> NAAQS at 35 [mu]g/m\3\.

B. Regulatory Actions in New Haven and Fairfield Counties

    Hereafter, ``New Haven-Fairfield'' means the Connecticut portion of 
the NY-NJ-CT maintenance area which is comprised of New Haven and 
Fairfield Counties. EPA promulgated the designations for New Haven-
Fairfield as a PM<INF>2.5</INF> nonattainment area for the 1997 annual 
PM<INF>2.5</INF> NAAQS on January 5, 2005 (70 FR 944) and the 2006 24-
hour PM<INF>2.5</INF> NAAQS (74 FR 58688) on November 13, 2009, due to 
measured violations of the standards. These designations became 
effective on April 5, 2005, and December 14, 2009, respectively. On 
June 22, 2012, CT DEEP submitted a request to EPA to redesignate the 
New Haven- Fairfield nonattainment area to attainment of both the 1997 
annual and 2006 24-hour PM<INF>2.5</INF> NAAQS. This submittal included 
a maintenance plan to provide for maintenance of the PM<INF>2.5</INF> 
NAAQS in the area for 10 years. EPA redesignated New Haven-Fairfield to 
attainment for the 1997 and 2006 PM<INF>2.5</INF> NAAQS on October 24, 
2013 (78 FR 58467) and approved the associated maintenance plan into 
the Connecticut State Implementation Plan (SIP). The purpose of CT 
DEEP's May 9, 2023 (supplemented on February 21, 2024) LMP submission 
is to fulfill the second 10-year planning requirement of CAA section 
175A(b), thus ensuring PM<INF>2.5</INF> NAAQS compliance through the 
end of the maintenance period.

[[Page 79190]]

    In the LMP submittal, CT DEEP indicates that it is seeking approval 
of the LMP for both the 2006 24-hour standard as well as the 1997 
annual standard. However, as explained in the PM<INF>2.5</INF> SIP 
Requirements Rule (81 FR 58009), a second 10-year maintenance plan for 
the revoked 1997 annual PM<INF>2.5</INF> NAAQS is not required. 
Therefore, CT DEEP clarified via email that it incorrectly sought 
approval of the plan for the revoked 1997 annual standard and asked 
that EPA ignore the request for approval of the plan for this standard. 
The email, sent on July 7, 2023, can be found in the docket of this 
action. Thus, EPA will only proceed with proposing approval of the LMP 
for the 2006 24-hour PM<INF>2.5</INF> NAAQS.

II. The Limited Maintenance Plan Option

A. Demonstration of Maintenance Using the Limited Maintenance Plan 
Option

    Section 175A of the CAA sets forth the elements of a maintenance 
plan. Under section 175A, a state must submit a revision to the SIP 
that provides for maintenance of the applicable NAAQS for at least 10 
years after an area is redesignated to attainment. Section 175A also 
requires that eight years into the first maintenance period, the state 
must submit a second maintenance plan demonstrating that the area will 
continue to attain for the following 10-year period.
    EPA has published long-standing guidance for states on developing 
maintenance plans.\1\ The Calcagni memo provides that states may 
generally demonstrate maintenance by either performing air quality 
modeling to show that the future mix of sources and emission rates will 
not cause a violation of the NAAQS or by showing that future emissions 
of a pollutant and its precursors will not exceed the level of 
emissions during a year when the area was attaining the NAAQS (i.e., 
attainment year inventory). EPA clarified in subsequent guidance memos 
that certain nonattainment areas could meet the CAA section 175A 
requirement to provide for maintenance by demonstrating that an area's 
design value is well below the NAAQS and that the historical stability 
of the area's air quality levels shows that the area is unlikely to 
violate the NAAQS in the future.\2\
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    \1\ See Calcagni, John, Director, Air Quality Management 
Division, EPA Office of Air Quality Planning and Standards, 
``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' September 4, 1992 (Calcagni memo). A copy of this 
memorandum can be found in the docket for this proposed rulemaking.
    \2\ See ``Limited Maintenance Plan Option for Nonclassifiable 
Ozone Nonattainment Areas'' from Sally L. Shaver, Office of Air 
Quality Planning and Standards (OAQPS), dated November 16, 1994; 
``Limited Maintenance Plan Option for Nonclassifiable CO 
Nonattainment Areas'' from Joseph Paisie, OAQPS, dated October 6, 
1995; and ``Limited Maintenance Plan Option for Moderate 
PM<INF>10</INF> Nonattainment Areas'' (PM<INF>10</INF> LMP Guidance) 
from Lydia Wegman, OAQPS, dated August 9, 2001. Copies of these 
guidance memoranda can be found in the docket for this proposed 
rulemaking.
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    Most recently, in October 2022, EPA released guidance extending 
this streamlined option for demonstrating maintenance under CAA section 
175A to certain PM<INF>2.5</INF> areas, titled ``Guidance on Limited 
Maintenance Plan Option for Moderate PM<INF>2.5</INF> Nonattainment 
Areas and PM<INF>2.5</INF> Maintenance Areas'' (PM<INF>2.5</INF> LMP 
Guidance).\3\ EPA refers to this streamlined demonstration of 
maintenance as an LMP. EPA has interpreted CAA section 175A as 
permitting this option because section 175A of the Act defines few 
specific content requirements for maintenance plans, and in EPA's 
experience implementing the various NAAQS, areas that qualify for an 
LMP and have approved LMPs have rarely, if ever, experienced subsequent 
violations of the NAAQS. As noted in the PM<INF>2.5</INF> LMP Guidance, 
states seeking an LMP should still submit the other maintenance plan 
elements outlined in the Calcagni memo, including: an attainment 
emissions inventory, provisions for the continued operation of the 
ambient air quality monitoring network, verification of continued 
attainment, and a contingency plan in the event of a future violation 
of the NAAQS. Moreover, states seeking an LMP must still submit their 
section 175A maintenance plan as a revision to their SIP, with all 
attendant notice and comment procedures.
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    \3\ See the guidance document developed by the Office of Air 
Quality Planning and Standards, the Office of Transportation and Air 
Quality, and the Office of Air and Radiation titled ``Guidance on 
the Limited Maintenance Plan Option for Moderate PM<INF>2.5</INF> 
Nonattainment Areas and PM<INF>2.5</INF> Maintenance Areas''. A copy 
of this guidance can be found in the docket for this proposed 
rulemaking.
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    The PM<INF>2.5</INF> LMP Guidance, similar to the PM<INF>10</INF> 
LMP Guidance, allows states to demonstrate that certain areas qualify 
for an LMP by showing that, based on their recent measured air quality, 
they are unlikely to violate the NAAQS in the future. Specifically, the 
PM<INF>2.5</INF> LMP Guidance relies on the critical design value (CDV) 
concept. This guidance directs states to calculate a site-specific CDV 
for the monitoring site in an area with the highest design value, and 
also for all other active monitoring sites in the area with complete 
data. The PM<INF>2.5</INF> LMP Guidance states that areas should show 
that the average design value (ADV) for each monitoring site in the 
area, i.e., the average of at least the most recent consecutive 5 years 
of PM<INF>2.5</INF> design values, does not exceed the associated CDV 
for each site.\4\ If the ADV for each monitoring site in the area is 
below the CDV then the probability of a future exceedance, based on the 
area's historical air quality and variability, is less than 10 percent. 
The CDV calculation for a monitoring site involves the following 
parameters: (1) the level of the relevant NAAQS; (2) the co-efficient 
of variation of recent design values measured at that site; and (3) a 
statistical parameter corresponding to a 10 percent probability of 
exceedance, such that sites with historically high variability in 
design values result in a lower (or more stringent) CDV. The 
eligibility calculation equations for the CDV demonstration are shown 
in table 1.
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    \4\ EPA recommends that the ADV be calculated using at least 
five years of design values, each representing a three-year period, 
because this approach would rely on a more robust dataset. However, 
we acknowledge that an alternative interpretation may be acceptable, 
where these variables could be calculated using three years of 
design values, collectively representing five years of air quality 
data.

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[[Page 79191]]

[GRAPHIC] [TIFF OMITTED] TP27SE24.001

B. Transportation Conformity Under Limited Maintenance Plan Option

    Transportation conformity is required by section 176(c) of the CAA. 
Under that provision, conformity to a SIP means that transportation 
activities will not cause or contribute to new air quality violations, 
worsen existing violations, delay timely attainment of the NAAQS or any 
required interim emission reductions or other milestones in any area. 
See CAA 176(c)(1)(A) and (B). EPA's transportation conformity rule at 
40 CFR part 93 subpart A establishes the criteria and procedures to 
determine whether metropolitan transportation plans, transportation 
improvement programs, and federally supported highway and transit 
projects conform to the SIP. Transportation conformity applies for 
transportation-related criteria pollutants in nonattainment areas and 
redesignated attainment areas with a CAA section 175A maintenance plan 
(i.e., maintenance areas).
    While qualification for the LMP option does not exempt an area from 
the need to determine conformity, in an area with an adequate or 
approved LMP, conformity may be demonstrated for a transportation plan 
or a transportation improvement program without a regional emissions 
analysis for the relevant NAAQS and pollutant (40 CFR 93.109(e)). 
However, transportation plan and transportation improvement program 
conformity determinations that meet applicable requirements continue to 
be required in these areas (see table 1 in 40 CFR 93.109). The areas 
also remain subject to the other transportation conformity requirements 
of 40 CFR part 93, subpart A, including fulfilling project-level 
conformity analyses requirements and consultation requirements. In 
addition, an LMP must demonstrate that it is unreasonable to expect 
that the qualifying area would experience enough growth in on-road 
emissions during the maintenance period such that a violation of the 
relevant NAAQS would occur (40 CFR 93.109(e)). Furthermore, consistent 
with the PM<INF>2.5</INF> LMP Guidance, if re-entrained road dust has 
been found to be significant for PM<INF>2.5</INF> transportation 
conformity purposes under 40 CFR 93.102(b)(3), the plan should include 
an on-road PM<INF>2.5</INF> emissions analysis consistent with the 
methodology provided in attachment B of the PM<INF>10</INF> LMP 
Guidance. EPA discusses CT DEEP's submittal in section III.A of this 
notice.
    Along with this proposed action, EPA is initiating an adequacy 
process for the New Haven and Fairfield LMP. See 40 CFR 93.118(e)(4) 
and 93.118(f). Since LMPs do not include motor vehicle emissions 
budgets, EPA's adequacy review is to assess whether the demonstration 
required by 40 CFR 93.109(e) is met.

C. General Conformity Under Limited Maintenance Plan Option

    The general conformity rule of November 30, 1993 (58 FR 63214) 
applies to nonattainment areas and redesignated attainment areas 
operating under maintenance plans (i.e., maintenance areas). General 
conformity requires compliance to the purpose of a SIP, which means 
that federal activities not related to transportation plans, programs, 
and projects will not cause or contribute to any new violation of any 
standard in any area, increase the frequency or severity of any 
existing violation of any standard in any area or delay timely 
attainment of any standard or any required interim emission reductions 
or other milestones in any area (CAA section 176(c)(1)(A)and(1)(B)). As 
noted in the PM<INF>2.5</INF> LMP Guidance, EPA's general conformity 
regulations do not distinguish between maintenance areas with an 
approved ``full maintenance plan'' and those with an approved LMP. 
Thus, maintenance areas with an approved LMP are subject to the same 
general conformity requirements under 40 CFR part 93 subpart B, as 
those covered by a ``full maintenance plan.'' Full compliance with the 
general conformity program is required within an LMP.

III. EPA's Analysis of the State's Submittal

A. Demonstration of Qualification for the Limited Maintenance Plan 
Option

    EPA redesignated New Haven- Fairfield to attainment of the 
PM<INF>2.5</INF> NAAQS on October 24, 2013 (78 FR 58467). Table 2 below 
shows the historical design values for each monitoring site within the 
maintenance area since it was redesignated in 2013.\5\ The 2006 24-hour 
PM<INF>2.5</INF> NAAQS is attained when the 3-year average of the 98th 
percentile of 24-hour PM<INF>2.5</INF>

[[Page 79192]]

concentrations is equal to or less than 35 [micro]g/m\3\, and as shown 
in table 2, the area has been measuring air quality well below the 2006 
PM<INF>2.5</INF> NAAQS with an overall decrease in PM<INF>2.5</INF> 
concentrations over time. These design values from the individual 
monitoring sites within the maintenance area demonstrate the stability 
of ambient PM<INF>2.5</INF> concentrations over time.
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    \5\ See https://www.epa.gov/air-trends/air-quality-design-values.

     Table 2--PM2.5 Design Values in New Haven-Fairfield Since Redesignation to Attainment in [micro]g/m\3\
                                                   [2013-2023]
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                                                    090010010--     090011123--     090090027--
                                                     Roosevelt     Western Conn      Criscuolo      090092123--
               Design value period                   School--          State        Park-- New      Meadow and
                                                    Bridgeport      University         Haven       Bank Streets
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2011-2013.......................................              23              25              24              23
2012-2014.......................................              23              24              21              24
2013-2015.......................................              24              25              22              24
2014-2016.......................................              24              23              20            * 23
2015-2017.......................................              21              22              20            * 20
2016-2018.......................................              20              21              19            * 20
2017-2019.......................................              19              20              18              19
2018-2020.......................................              21              21              20              20
2019-2021.......................................              22              21              21              20
2020-2022.......................................              21              22              21              21
2021-2023.......................................              21              21              20          \6\ 20
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* 24-hr data invalid due to site reconstruction.

    EPA proposes to find that the New Haven-Fairfield area meets the 
critical design value demonstration for an LMP. As noted above, the 
parameters of the CDV calculation include the level of the relevant 
NAAQS, the co-efficient of variation of recent design values, and a 
statistical parameter corresponding to a 10 percent probability of 
future violation. The CDV demonstration is designed such that if a 
site's ADV is lower than the site's CDV, the probability of a future 
violation of the NAAQS is less than 10 percent.\7\ Section 2.2 of CT 
DEEP's LMP submittal demonstrates the likelihood of continued 
attainment. EPA reviewed the data and methodology provided by the state 
and we find that each monitor's 5-year ADV is well below the 
corresponding site-specific CDV, as shown in table 3.
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    \6\ The 2020-2022 and 2021-2023 design values were not finalized 
until after CT DEEP submitted the PM<INF>2.5</INF> LMP to EPA; they 
are included here to show the most recent air quality data.
    \7\ See the ``Example Site Calculation'', page 7 of the October 
2022 PM<INF>2.5</INF> LMP guidance, found in the docket for this 
rulemaking.

       Table 3--Results of Calculation of CDVs at New Haven-Fairfield Monitors for the 24-Hour PM2.5 NAAQS
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                                                                Average design
                                                                 value (2017-
                     Site                             CDV          2021) \a\            Qualify for LMP?
 
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090010010.....................................            32.3            20.6  Yes.
090011123.....................................            33.3            21.0  Yes.
090090027.....................................            32.1            19.6  Yes.
090092123.....................................            33.2        \b\ 19.7  Yes.
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\a\ CT DEEP uses the term `mean' interchangeably with ADV in the proposed LMP; the design values averaged for
  the ADV span seven years of data (2015-2017, 2016-2018, 2017-2019, 2018-2020, 2019-2021).
\b\ Only three years of design values (5 years of data) were used for the Meadow and Bank Streets' monitor due
  to site reconstruction. activities resulting in incomplete data for 2016 and invalidating design values for
  2016-2018.

    We also propose to find that the CT DEEP LMP submittal satisfies 
transportation conformity regulations under the LMP option. Connecticut 
holds annual transportation conformity interagency consultation 
meetings which include Federal, State, and local agencies. 
Additionally, the LMP SIP submittal for New Haven-Fairfield was 
developed in accordance with interagency consultation between Federal, 
State, and local partners. CT DEEP also includes analysis that 
addresses the demonstration under 40 CFR 93.109(e) in their supplement 
submitted on February 21, 2024. This transportation conformity 
regulation requires that an LMP would have to demonstrate that it would 
be unreasonable to expect that a maintenance area would experience 
enough motor vehicle emissions growth for a NAAQS violation to occur 
(40 CFR 93.109(e)).
    The state's demonstration assesses the total projected growth in 
on-road motor vehicle PM<INF>2.5</INF> emissions through the end of the 
20-year maintenance period, where the projected percentage increase in 
vehicle miles traveled (VMT<INF>pi</INF>) to the end of the 20-year 
maintenance period (i.e., 2033), is multiplied by the motor vehicle 
design value (DV<INF>mv</INF>). The DV<INF>mv</INF> is based on the on-
road mobile portion of the attainment year inventory. CT DEEP analyzed 
whether the area's ADV for the period used to demonstrate LMP 
qualification plus (VMT<INF>pi</INF> x DV<INF>mv</INF>) was less than 
or equal to the CDV for the relevant PM<INF>2.5</INF> standard in 
[micro]g/m\3\ for the given area. The state calculated the CDV for the 
entire maintenance area, 33 [mu]g/m\3\, using the most recent (2017-
2021) maximum design values from each year.\8\ CT DEEP calculated the 
projected

[[Page 79193]]

design value in 2033 to be 21.49 [mu]g/m\3\ which is less than the 
determined CDV, 33 [mu]g/m\3\. Thus, CT DEEP concludes that it is 
unlikely that increased emissions from on-road mobile sources could, in 
the next 10 years, increase concentrations in the area enough to 
threaten the maintenance of the PM<INF>2.5</INF> NAAQS. In consultation 
with the Connecticut Department of Transportation (CTDOT), CT DEEP also 
provided a VMT<INF>pi</INF> of .0565 from 2017 to 2033, which is a 
5.65% increase.
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    \8\ See appendix A of the state submittal for the complete 
calculation, which is included in the docket of this rulemaking.
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    The VMT projection considered by Connecticut was based on the on-
road emissions analysis calculation as laid out in the PM<INF>10</INF> 
LMP Guidance. Under the PM<INF>2.5</INF> LMP Guidance, this on-road 
emissions analysis is only necessary for LMPs where re-entrained road 
dust has been found to be significant for PM<INF>2.5</INF> 
transportation conformity purposes under 40 CFR 93.102(b)(3) for a 
given maintenance area. While CT DEEP does not identify re-entrained 
road dust as a significant contributor to PM<INF>2.5</INF> 
concentrations in the maintenance area, the state utilizes the same 
methodology to address projected VMT and motor vehicle emissions growth 
in its LMP submittal. CT DEEP's analysis indicates that the projected 
design value in 2033 is significantly below the area's CDV signaling 
future continued maintenance of the relevant NAAQS, with limited growth 
in VMT from 2017 to 2033. This analysis supports a conclusion that the 
state has demonstrated that it would be unreasonable to expect New 
Haven-Fairfield to experience enough growth in on-road emissions during 
the remaining maintenance period such that a violation of the 2006 24-
hour PM<INF>2.5</INF> NAAQS will occur.
    Also, per 40 CFR 93.109(e), an area with an adequate or approved 
LMP is not required to satisfy the regional emissions analysis for 
Sec.  93.118 and/or Sec.  93.119 for a given pollutant and NAAQS, in 
this instance the 2006 PM<INF>2.5</INF> NAAQS. However, the first 10-
year maintenance plan for the New Haven-Fairfield area included motor 
vehicle emissions budgets for 2025. Therefore, if 2025 is within the 
timeframe of any transportation plan or transportation improvement 
program (TIP) and transportation conformity is determined for that plan 
or TIP, a regional emissions analysis is required for 2025.
    In the PM<INF>2.5</INF> LMP Guidance, EPA clarifies that an area 
submitting the second 10-year maintenance plan may be eligible for the 
LMP option if monitored air quality data and VMT trends support the LMP 
option. Given the air quality data demonstrating that New Haven- 
Fairfield has been maintaining the 2006 PM<INF>2.5</INF> NAAQS for at 
least 8 years, the current PM<INF>2.5</INF> design values in the area, 
the demonstrated downward trend in PM<INF>2.5</INF> concentrations over 
the last ten years, and the state's on-road emissions analysis of 
projected VMT discussed above, we propose to find that CT DEEP's LMP 
submittal for the New Haven-Fairfield 2006 PM<INF>2.5</INF> maintenance 
area meets the qualification criteria for an LMP, consistent with 40 
CFR 93.109(e) and the PM<INF>2.5</INF> LMP Guidance.
    The following is a summary of EPA's interpretation of the section 
175A requirements and EPA's evaluation of how each requirement is met. 
Under the LMP option, the state will be expected to determine on a 
regular basis that the criteria are still being met. If the state 
determines that the LMP criteria are not being met, it should take 
action to reduce PM<INF>2.5</INF> concentrations enough to requalify. 
One possible approach the state could take is to implement the 
contingency measures contained in its first maintenance plan (78 FR 
58467), that the state will continue to adhere to for the second 
maintenance period (See section 3.6 of the current state submittal). If 
the attempt to reduce PM<INF>2.5</INF> concentrations fails, or if it 
succeeds but in future years it becomes necessary again to address 
increasing PM<INF>2.5</INF> concentrations in an area, the area will no 
longer qualify for the LMP option.

B. Attainment Inventory

    As noted above, states that qualify for an LMP must still meet the 
other elements of a maintenance plan, as articulated in the Calcagni 
Memo. This includes an attainment year emissions inventory. CT DEEP's 
New Haven-Fairfield PM<INF>2.5</INF> LMP submission includes an 
emissions inventory, with a base year of 2017. This inventory was 
prepared as part of the 2017 National Emissions Inventory \9\ Version 2 
under EPA's Air Emissions Reporting Rule (73 FR 76539, December 17, 
2008). The 2017 base year represents the most recent emissions 
inventory data available when the state prepared the submission and is 
representative of the level of emissions during a period that the area 
shows monitored attainment of the NAAQS and is consistent with the data 
used to determine applicability of the LMP option (i.e., having no 
violations of the NAAQS during the 5-year period used to calculate the 
design value). Table 3 shows the total 2017 emissions in New Haven-
Fairfield in tons per year included in the state's submission.
---------------------------------------------------------------------------

    \9\ See https://www.epa.gov/air-emissions-inventories/2017-national-emissions-inventory-nei-data.

       Table 3--2017 Emissions (Tons/Year) in New Haven-Fairfield
------------------------------------------------------------------------
                                                               Total
                        Pollutant                            emissions
------------------------------------------------------------------------
PM2.5...................................................           4,361
Ammonia (NH3)...........................................           1,485
Nitrogen oxides (NOX)...................................          22,020
Sulfur dioxide (SO2)....................................           1,296
Volatile organic compounds (VOCs).......................          43,518
------------------------------------------------------------------------

C. Air Quality Monitoring Network

    Once an area is redesignated, the state must continue to operate an 
appropriate air monitoring network in accordance with 40 CFR part 58 to 
verify the attainment status of the area. CT DEEP continues to operate 
a PM<INF>2.5</INF> monitoring network sited and maintained in 
accordance with federal siting and design criteria in 40 CFR part 58, 
and in consultation with EPA Region 1. CT DEEP submitted its 2023 
Annual Monitoring Network Plan on June 26, 2023,\10\ which EPA approved 
on July 12, 2023.\11\ In the LMP submittal, CT DEEP commits to 
continued operation of its PM<INF>2.5</INF> monitors within New Haven-
Fairfield, consistent with the EPA-approved CT DEEP annual network 
plan. Currently, there are 4 monitors in the New Haven-Fairfield 
maintenance area.
---------------------------------------------------------------------------

    \10\ See CT DEEP's 2023 Annual Air Monitoring Network Plan found 
in the docket for this proposed rulemaking.
    \11\ See EPA'S Approval Letter for CT DEEP'S 2023 Annual 
Monitoring Network Plan found in the docket for this proposed 
rulemaking.
---------------------------------------------------------------------------

D. Verification of Continued Attainment

    The level of the 2006 24-hour PM<INF>2.5</INF> NAAQS is 35 [mu]g/
m\3\ (40 CFR 50.13). The NAAQS is attained when the 3-year average of 
the 98th percentile of PM<INF>2.5</INF> concentrations is equal to or 
less than the NAAQS, which CT DEEP has proven in its LMP submittal. As 
stated previously, CT DEEP commits to verifying continued attainment of 
the PM<INF>2.5</INF> standards through the maintenance plan period with 
the operation of an appropriate PM<INF>2.5</INF> monitoring network. In 
developing the second 10-year maintenance plan, CT DEEP evaluated the 
last 5 years of complete, quality-assured data (2017 through 2021) for 
New Haven-Fairfield at the time of the submittal to verify continued 
attainment of the standard. Certified air quality data from 2023, as

[[Page 79194]]

shown in table 2, confirms continued attainment of the standard.\12\
---------------------------------------------------------------------------

    \12\ See https://www.epa.gov/air-trends/air-quality-design-values.
---------------------------------------------------------------------------

E. Contingency Provisions

    CAA section 175A(d) states that a maintenance plan must include 
contingency provisions, as necessary, to ensure prompt correction of 
any violation of the relevant NAAQS which may occur after redesignation 
of the area to attainment. As explained in the Calcagni memo, these 
contingency provisions are an enforceable part of the federally 
approved SIP. The maintenance plan should clearly identify the events 
that would ``trigger'' the adoption and implementation of a contingency 
provision, the contingency provision(s) that would be adopted and 
implemented, and the schedule indicating the timeframe by which the 
state would adopt and implement the provision(s). The Calcagni memo 
states that EPA will determine the adequacy of a contingency plan on a 
case-by-case basis. At a minimum, the plan must require that the state 
implement all measures contained in the CAA part D nonattainment plan 
for the area prior to redesignation.
    CT DEEP will continue to adhere to the contingency plan they 
submitted with their first maintenance plan, which includes the 
required contingency provisions to ensure the area will promptly 
correct any violation of the 2006 PM<INF>2.5</INF> NAAQS.\13\ 
Connecticut's contingency measures include a Warning Level Response and 
an Action Level Response. CT DEEP also commits to pursuing adoption 
(and submittal to EPA) and implementation of any appropriate regulatory 
revisions within 18 to 24 months after the verified violation. CT DEEP 
will select contingency measures based on cost effectiveness, emission 
reduction potential, economic and social considerations, or other 
appropriate factors. Stakeholder input will be solicited before final 
selection of any contingency measures. The contingency measures are 
described in detail in the NPRM for the first maintenance plan and will 
not be repeated here. See 78 FR 43096. EPA proposes to find that the 
contingency provisions in the PM<INF>2.5</INF> LMP for the New Haven-
Fairfield 2006 PM<INF>2.5</INF> maintenance area meet the requirements 
of section 175A(d) of the CAA.
---------------------------------------------------------------------------

    \13\ See section 5.4 of PM<INF>2.5</INF> post-comment 
supplemental submission to EPA found in the docket for this proposed 
rulemaking.
---------------------------------------------------------------------------

IV. Proposed Action

    EPA is proposing to approve the second 10-year PM<INF>2.5</INF> LMP 
for the New Haven-Fairfield 2006 24-hour PM<INF>2.5</INF> maintenance 
area submitted by CT DEEP on May 9, 2023, and supplemented on February 
21, 2024. EPA's review of the air quality data for the maintenance area 
indicates that it continues to show attainment well below the level of 
the 2006 24-hour PM<INF>2.5</INF> NAAQS and meet all the LMP qualifying 
criteria as described in this action. If finalized, EPA's approval of 
this LMP will satisfy the CAA section 175A requirements for the second 
10-year maintenance period.
    As discussed previously, EPA is also initiating as part of this 
proposed rulemaking the process to determine if the LMP is adequate for 
transportation conformity purposes. Any comments on the adequacy of the 
submitted CT LMP should be submitted to the docket established for this 
rulemaking. EPA may complete that process either in a final action on 
this LMP or through a separate process provided for in the 
transportation conformity regulations. See 40 CFR 93.118(f). EPA is 
soliciting public comments on the issues discussed in this notice or on 
other relevant matters. These comments will be considered before taking 
final action. Interested parties may participate in the Federal 
rulemaking procedure by submitting written comments to this proposed 
rule by following the instructions listed in the ADDRESSES section of 
this Federal Register.

V. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a 
SIP submission that complies with the provisions of the Act and 
applicable Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). 
Thus, in reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. 
Accordingly, this proposed action merely approves state law as meeting 
Federal requirements and does not impose additional requirements beyond 
those imposed by state law. For that reason, this proposed action:
    <bullet> Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
    <bullet> Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
    <bullet> Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
    <bullet> Is not subject to requirements of section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the Clean Air Act.
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rule does not have tribal implications and will not impose 
substantial direct costs on tribal governments or preempt tribal law as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
Feb. 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on communities with environmental justice 
(EJ) concerns to the greatest extent practicable and permitted by law. 
EPA defines EJ as ``the fair treatment and meaningful involvement of 
all people regardless of race, color, national origin, or income with 
respect to the development, implementation, and enforcement of 
environmental laws, regulations, and policies.'' EPA further defines 
the term fair treatment to mean that ``no group of people should bear a 
disproportionate burden of environmental harms and risks, including 
those resulting from the negative environmental consequences of 
industrial, governmental, and commercial operations or programs and 
policies.''
    CT DEEP did not evaluate environmental justice considerations as 
part of its SIP submittal; the CAA and applicable implementing 
regulations

[[Page 79195]]

neither prohibit nor require such an evaluation. EPA did not perform an 
EJ analysis and did not consider EJ in this action. Due to the nature 
of the action being taken here, this action is expected to have a 
neutral to positive impact on the air quality of the affected area. 
Consideration of EJ is not required as part of this action, and there 
is no information in the record inconsistent with the stated goal of 
E.O. 12898 of achieving environmental justice for communities with EJ 
concerns.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Nitrogen dioxide, Particulate matter, Sulfur oxides, 
Volatile organic compounds.

    Dated: September 23, 2024.
David Cash,
Regional Administrator, EPA Region 1.
[FR Doc. 2024-22114 Filed 9-26-24; 8:45 am]
BILLING CODE 6560-50-P


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