Proposed Rule2026-01314
Air Plan Approval; Maryland; Clean Data Determination for the Baltimore, MD Nonattainment Area for the 2015 Ozone National Ambient Air Quality Standards
Primary source
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Published
January 23, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to determine that the Baltimore, Maryland nonattainment area (the Baltimore Area or the Area) has clean data for the 2015 8-hour ozone national ambient air quality standards (2015 ozone NAAQS or standard). This proposed clean data determination (CDD) under the EPA's Clean Data Policy is based upon quality-assured, quality-controlled, and certified ambient air quality monitoring data showing that the Baltimore Area has attained the 2015 ozone NAAQS based on 2022-2024 data available in the EPA Air Quality System (AQS) database. If finalized, this proposed CDD would suspend the obligations of the State of Maryland (MD) to submit certain attainment area planning requirements for as long as the Baltimore Area continues to attain the 2015 ozone NAAQS. As part of this rulemaking, the EPA also proposes to take final agency action on portions of exceptional events requests submitted by MD on February 2, 2024 and concurred on by the EPA on November 12, 2025. The proposed CDD is based upon the EPA's concurrence on portions of the exceptional events demonstrations. This action is being taken under the Clean Air Act (CAA).
Full Text
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<title>Federal Register, Volume 91 Issue 15 (Friday, January 23, 2026)</title>
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[Federal Register Volume 91, Number 15 (Friday, January 23, 2026)]
[Proposed Rules]
[Pages 2887-2892]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-01314]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R03-OAR-2025-2532; FRL-13045-01-R3]
Air Plan Approval; Maryland; Clean Data Determination for the
Baltimore, MD Nonattainment Area for the 2015 Ozone National Ambient
Air Quality Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
determine that the Baltimore, Maryland nonattainment area (the
Baltimore Area or the Area) has clean data for the 2015 8-hour ozone
national ambient air quality standards (2015 ozone NAAQS or standard).
This proposed clean data determination (CDD) under the EPA's Clean Data
Policy is based upon quality-assured, quality-controlled, and certified
ambient air quality monitoring data showing that the Baltimore Area has
attained the 2015 ozone NAAQS based on 2022-2024 data available in the
EPA Air Quality System (AQS) database. If finalized, this proposed CDD
would suspend the obligations of the State of Maryland (MD) to submit
certain attainment area planning requirements for as long as the
Baltimore Area continues to attain the 2015 ozone NAAQS. As part of
this rulemaking, the EPA also proposes to take final agency action on
portions of exceptional events requests submitted by MD on February 2,
2024 and concurred on by the EPA on November 12, 2025. The proposed CDD
is based upon the EPA's concurrence on portions of the exceptional
events demonstrations. This action is being taken under the Clean Air
Act (CAA).
DATES: Written comments must be received on or before February 23,
2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R03-
OAR-2025-2532 at <a href="http://www.regulations.gov">www.regulations.gov</a>, or via email to
<a href="/cdn-cgi/l/email-protection#1b7c74697f7475357672707e5b7e6b7a357c746d"><span class="__cf_email__" data-cfemail="fc9b938e989392d291959799bc998c9dd29b938a">[email protected]</span></a>. For comments submitted at <a href="http://Regulations.gov">Regulations.gov</a>, follow
the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. 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 <a href="http://www.epa.gov/dockets/commenting-epa-dockets">www.epa.gov/dockets/commenting-epa-dockets</a>.
FOR FURTHER INFORMATION CONTACT: Ian Neiswinter, Planning &
Implementation Branch (3AD30), Air & Radiation Division, U.S.
Environmental Protection Agency, Region III, 1600 John F. Kennedy
Boulevard, Philadelphia, Pennsylvania 19103. The telephone number is
(215) 814-2011. Mr. Neiswinter can also be reached via electronic mail
at <a href="/cdn-cgi/l/email-protection#89e7ece0fafee0e7fdecfba7e0e8e7c9ecf9e8a7eee6ff"><span class="__cf_email__" data-cfemail="e688838f95918f88928394c88f8788a6839687c8818990">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, wherever ``we,''
``us'' or ``our'' are used, it is intended to refer to the EPA.
[[Page 2888]]
I. Background
On October 26, 2015 (80 FR 65292), the EPA promulgated a revised
primary and secondary ozone NAAQS to provide requisite increased
protection of public health and welfare, respectively. In that action,
the EPA strengthened both standards from 0.075 parts per million (ppm)
to 0.070 ppm and retained the indicator (ozone), averaging time (8-
hour), and form (annual fourth-highest daily maximum, averaged over
three years) of the existing standards. Effective August 3, 2018 (83 FR
25776, June 4, 2018), the EPA designated 52 areas throughout the
country as nonattainment for the 2015 ozone NAAQS, including the
Baltimore Area,\1\ which was classified as a Marginal nonattainment
area. This designation was based on quality-assured, quality-
controlled, and certified air quality monitoring data from calendar
years 2014-2016. The EPA established the attainment date for Marginal
2015 ozone NAAQS nonattainment areas as 3 years from the effective date
of the final designations, meaning the Baltimore Area had an attainment
date of August 3, 2021.\2\
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\1\ The Baltimore Area consists of the following counties/
cities: Anne Arundel County, Baltimore County, Carroll County,
Harford County, Howard County, and the City of Baltimore in
Maryland. See 40 Code of Federal Regulation (CFR) 81.321.
\2\ See 83 FR 10376 (March 9, 2018) and 40 CFR 51.1303(a).
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Effective November 7, 2022 (87 FR 60897, October 7, 2022), the EPA
determined that 22 Marginal areas or portions of areas failed to attain
the standard \3\ by the applicable Marginal attainment date, including
the Baltimore Area. In that action, the EPA reclassified the Baltimore
Area as Moderate nonattainment for the 2015 ozone NAAQS because it
failed to attain the standard by the attainment date of August 3, 2021.
That designation was based on quality-assured, quality-controlled, and
certified ambient air monitoring data from calendar years 2018-2020. In
that same action, the EPA established the Moderate attainment date as
August 3, 2024.\4\
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\3\ Because the 2015 primary and secondary NAAQS for ozone are
identical, for convenience, the EPA refers to them in the singular
as ``the 2015 ozone NAAQS'' or as ``the standard.''
\4\ See 87 FR 60897 (October 7, 2022).
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On July 18, 2024, MD requested that the EPA reclassify the
Baltimore Area from Moderate to Serious. On August 1, 2024 (89 FR
62663), the EPA approved MD's reclassification request from Moderate to
Serious under CAA section 181(b)(3), which provides for ``voluntary
reclassification''. Because of that action, the Baltimore Area must now
attain the 2015 ozone NAAQS as expeditiously as practicable, but no
later than nine years from the date of the initial designation as
nonattainment, i.e., August 3, 2027.
On February 2, 2024 the Maryland Department of the Environment
(MDE), on behalf of MD, submitted three exceptional events (EE)
demonstrations to show that the ozone concentration at certain MD
monitors on June 2, June 29-30, and July 17-18, 2023 were influenced by
wildfire smoke events originating in Canada and/or the United
States.\5\ On May 6, 2025, MDE provided additional information for the
June 2, 2023 demonstration. On November 12, 2025, the EPA concurred on
portions of the June 2, June 29-30, and July 17-18, 2023 EE
demonstrations. Ambient air monitoring data from 2022 to 2024, which
pursuant to the EPA's concurrence on portions of the three MDE EE
demonstrations now excludes exceptional event influenced monitor days,
indicates that the Baltimore Area has attained the 2015 ozone NAAQS.
The EPA's Exceptional Events Rule and MDE's EE demonstrations are
discussed in more detail in section II of this document. Three separate
Technical Support Documents (TSDs) detailing the EPA's rationale for
concurring with portions of MDE's EE demonstrations are included in the
docket for this action.
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\5\ Maryland submitted two additional EE demonstrations for
which the EPA is not currently taking agency action on in this
proposed rulemaking.
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II. Exceptional Events Demonstration
Congress has recognized that it may not be appropriate for the EPA
to use certain monitoring data collected by the ambient air quality
monitoring network and maintained in the EPA's AQS database in certain
regulatory determinations. Thus, in 2005, Congress provided the
statutory authority for the exclusion of data influenced by
``exceptional events'' meeting specific criteria by adding section
319(b) to the CAA and granted the EPA with the authority to propose
regulations to review and manage air quality monitoring data influenced
by exceptional events.\6\
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\6\ Under CAA section 319(b), an exceptional event means an
event that: (i) affects air quality; (ii) is not reasonably
controllable or preventable; (iii) is an event caused by human
activity that is unlikely to recur at a particular location or a
natural event; and (iv) is determined by the EPA under the process
established in regulations promulgated by the EPA in accordance with
section 319(b)(2) to be an exceptional event. For the purposes of
section 319(b), an exceptional event does not include: (i)
stagnation of air masses or meteorological inversions; (ii) a
meteorological event involving high temperatures or lack of
precipitation; or (iii) air pollution relating to source
noncompliance.
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On March 22, 2007 (72 FR 13560), the EPA promulgated the 2007
Exceptional Events Rule in order to implement this 2005 CAA amendment.
The 2007 Exceptional Events Rule created a regulatory process codified
at 40 Code of Federal Regulations (CFR) parts 50 and 51 (sections 50.1,
50.14, and 51.930). These regulatory sections, which superseded the
EPA's previous guidance on handling data influenced by exceptional
events, contain definitions, procedural requirements, requirements for
air agency demonstrations, criteria for the EPA's approval of the
exclusion of event-affected air quality data from the data set used for
regulation decisions, and requirements for air agencies to take
appropriate and reasonable actions to protect public health from
exceedances and violations of the NAAQS. On October 3, 2016 (81 FR
68216), the EPA promulgated a comprehensive revision to the 2007
Exceptional Events Rule.
The 2016 Exceptional Events Rule revision included the requirement
that, if a state demonstrates to the Administrator's satisfaction that
emissions from a wildfire smoke event cause a specific air pollution
concentration in excess of the NAAQS at a particular air quality
monitoring location and otherwise satisfies the requirements of 40 CFR
50.14, the EPA must exclude that data from use in determinations of
exceedances and violations.\7\
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\7\ 40 CFR 50.14(b)(4).
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The CAA provides for the exclusion of air quality monitoring data
from design value (DV) \8\ calculations when there are NAAQS
exceedances caused by events, such as wildfires, that meet the criteria
for an exceptional event identified in CAA section 319(b) and in the
EPA's Exceptional Events Rule at 40 CFR 50.1, 50.14, and 51.930. For
the purposes of this proposed action, on February 2, 2024 MDE, on
behalf of MD, submitted three EE demonstrations to show that the ozone
concentration at certain MD monitors on June 2, June 29-30, and July
17-18, 2023 were influenced by wildfire smoke events originating in
Canada and/or the United States. On May 6, 2025 MDE provided additional
information for the June 2, 2023 demonstration.
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\8\ A design value (DV) is a statistic used to compare data
collected at an ambient air quality monitoring site to the
applicable NAAQS to determine compliance with the standard. The DV
for the 2015 ozone NAAQS is the 3-year average of the annual fourth
highest daily maximum 8-hour average ozone concentration. The DV is
calculated for each air quality monitor in an area, and the DV for
an area is the highest DV among the individual monitoring sites
located in the area.
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[[Page 2889]]
The EPA found that MDE's June 2, June 29-30, and July 17-18, 2023
demonstrations met the Exceptional Events Rule criteria and determined
that monitoring data impacted by wildfire smoke had regulatory
significance for purposes of calculating the Baltimore Area's most
recent DV (2022-2024 monitoring data). The removal of this exceptional
event-impacted data, consistent with the CAA and the implementing
regulations, supports a CDD for the 2015 ozone NAAQS. As such, the EPA
proposes to take final regulatory action on the concurred dates,
summarized in Table 1 of this action and detailed in the docket, and
remove from the dataset used for regulatory purposes those monitor days
that the EPA concurred on as influenced by an exceptional event
consistent with CAA section 319(b) and the implementing regulations.\9\
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\9\ At this time, the EPA defers action on other monitor-days
included in the June 29-30 and July 17-18 demonstrations, details of
which are included in the EPA's TSDs and associated letter included
in the docket for this action.
Table 1--EPA Decisions for Exceptional Events Exclusion
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EPA decision Location Site name AQS ID Event date
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Concur......................... Harford County.... Aldino............ 24-025-9001 June 2, 2023.
Concur......................... Harford County.... Edgewood.......... 24-025-1001 June 2, 2023.
Concur......................... Baltimore County.. Essex............. 24-005-3001 June 2, 2023.
Concur......................... Baltimore County.. Essex............. 24-005-3001 June 29, 2023.
Concur......................... Harford County.... Aldino............ 24-025-9001 June 29, 2023.
Concur......................... Harford County.... Edgewood.......... 24-025-1001 June 29, 2023.
Concur......................... Anne Arundel Glen Burnie....... 24-003-1003 June 29, 2023.
County.
Concur......................... Baltimore City.... Lake Montebello... 24-510-5253 June 29, 2023.
Concur......................... Baltimore County.. Padonia........... 24-005-1007 June 29, 2023.
Concur......................... Carroll County.... South Carroll..... 24-013-0001 June 29, 2023.
Concur......................... Harford County.... Aldino............ 24-025-9001 June 30, 2023.
Concur......................... Harford County.... Aldino............ 24-025-9001 July 17, 2023.
Concur......................... Harford County.... Edgewood.......... 24-025-1001 July 17, 2023.
Concur......................... Baltimore County.. Essex............. 24-005-3001 July 17, 2023.
Concur......................... Baltimore City.... Lake Montebello... 24-510-5253 July 17, 2023.
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The rationale of the EPA's exceptional events proposal is detailed
in the docket. For this proposed action, the EPA will rely on the
calculated design values that exclude the exceptional event-influenced
data for the purpose of demonstrating attainment of the 2015 ozone
NAAQS. Further details on MDE's analysis and the EPA's determination,
including the exceptional events initial notification, exceptional
events demonstration, and the EPA's response to the initial
notification can be found in the docket for this regulatory action.
While the EPA has concurred on portions of MDE's request to exclude
exceptional event-influenced air quality monitoring data from
regulatory decisions, these regulatory actions require the EPA to
provide an opportunity for public comment on the claimed exceptional
events and all supporting data prior to the EPA taking final agency
action. This proposed action provides the public with an opportunity to
comment on the claimed exceptional events, all supporting documents,
and the EPA's concurrence on MDE's request.
III. The EPA's Clean Data Policy and Clean Data Determination
Following the enactment of the CAA Amendments of 1990, the EPA
discussed its interpretation of the requirements for implementing the
NAAQS in the ``General Preamble for the Implementation of title I of
the CAA Amendments of 1990'' (General Preamble).\10\ In 1995, based on
the interpretation of CAA sections 171, 172, and 182 in the General
Preamble, the EPA set forth what has become known as its ``Clean Data
Policy'' for the 1-hour ozone NAAQS.\11\ Under the Clean Data Policy,
for a nonattainment area that can demonstrate attainment of the
standard before implementing CAA nonattainment measures, the EPA
interprets the requirements of the CAA that are specifically designed
to help an area achieve attainment, including attainment
demonstrations, implementation of reasonably available control measures
(RACM), reasonable further progress (RFP) demonstrations, emissions
limitations and control measures as necessary to provide for
attainment, and contingency measures, to be suspended for so long as
air quality continues to meet the standard.\12\
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\10\ 57 FR 13498, 13564 (April 16, 1992).
\11\ See Memorandum from John S. Seitz, Director, Office of Air
Quality Planning and Standards, entitled, ``Reasonable Further
Progress, Attainment Demonstration, and Related Requirements for
Ozone Nonattainment areas Meeting the Ozone National Ambient Air
Quality Standard,'' dated May 10, 1995. (1995 John S. Seitz Memo).
Further description of the EPA's Clean Data Policy can be found in
the ``Final Rule to Implement the 8-hour Ozone National Ambient Air
Quality Standard--Phase 2'' (referred to as the Phase 2 Final Rule),
(70 FR 71612, November 29, 2005). The EPA embodied the Clean Data
Policy for the 2015 ozone NAAQS in the final rule ``Implementation
of the 2015 National Ambient Air Quality Standards for Ozone:
Nonattainment Area State Implementation Plan Requirements'', (83 FR
62998, December 6, 2018). See 40 CFR 52.1318. The Tenth, Seventh,
and Ninth Circuit U.S. District Courts have upheld the EPA
rulemakings applying the Clean Data Policy. See Sierra Club v. EPA,
99 F. 3d 1551 (10th Cir. 1996); Sierra Club v. EPA, 375 F. 3d 537
(7th Cir. 2004); Our Children's Earth Foundation v. EPA, No. 04-
73032 (9th Cir., June 28, 2005) memorandum opinion.
\12\ 1995 John S. Seitz memo.
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The EPA may issue a CDD under the EPA's Clean Data Policy when a
nonattainment area is attaining the 2015 ozone NAAQS based on the most
recent available data. The EPA will determine whether the area has
attained the 2015 ozone NAAQS based on available information, including
air quality monitoring data for the affected area. If the CDD is made
final, then certain attainment plan requirements for the area are
suspended for so long as the area continues to attain the NAAQS.\13\
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\13\ See 40 CFR 51.1318.
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Furthermore, the suspension of the obligation to submit an
attainment plan is only appropriate while the area remains in
attainment of the NAAQS. A CDD under the Clean Data Policy does not
serve to alter the area's nonattainment designation. The EPA will not
take final action on the CDD for the Baltimore Area if the DV of a
monitoring site within the Area violates the 2015 ozone NAAQS prior to
final approval of the CDD. CDDs are not redesignations to attainment.
For the EPA to redesignate an area to attainment
[[Page 2890]]
the state must submit, and the EPA must approve, a redesignation
request for the area that meets the requirements of CAA section
107(d)(3), which includes the approval of a maintenance plan.
IV. The EPA's Analysis of Air Quality Data
The EPA has reviewed the 2022 through 2024 quality-assured,
quality-controlled, and certified ambient air quality monitoring data
for ozone for the Baltimore Area, consistent with the requirements
contained in 40 CFR 50.19(b) and 40 CFR part 50, appendix U, and
recorded in the EPA's AQS database. Preliminary data for 2025 was also
reviewed by the EPA; however, this data has not been certified.\14\ MD
is required to certify this data by May 1, 2026.\15\
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\14\ Preliminary 2025 ozone data for the Baltimore Area can be
viewed at: <a href="http://www.epa.gov/outdoor-air-quality-data/ozone-watch">www.epa.gov/outdoor-air-quality-data/ozone-watch</a>.
\15\ See 40 CFR 58.15.
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Under the EPA regulations at 40 CFR 50.19(b) and 40 CFR part 50,
appendix U, the 2015 ozone NAAQS is attained when the 3-year average of
the annual fourth-highest daily maximum 8-hour average ambient air
quality ozone concentration (i.e., DV) does not exceed 0.070 ppm at
each monitor site within the nonattainment area.\16\ Notably, the 2015
ozone NAAQS DVs are based solely on ozone season data.\17\ Ozone season
is defined for each state or portion of a state at 40 CFR part 58,
appendix D, section 4.1, Table D-3. The ozone season for MD runs
annually from March 1 to October 31.\18\
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\16\ The rounding convention in 40 CFR part 50, appendix U
dictates that concentrations shall be reported in ``ppm'' to the
third decimal place, with additional digits to the right being
truncated. Thus, a computed 3-year average ozone concentration of
0.071 ppm is greater than 0.070 ppm and would exceed the standard,
but a DV of 0.0709 is truncated to 0.070 and attains the 2015 ozone
NAAQS.
\17\ See 40 CFR 51.1300(b), which refers to 40 CFR part 50,
appendix U.
\18\ See 40 CFR 51.1300(j), which refers to 40 CFR part 58,
appendix D, section 4.1, Table D-3.
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The data completeness requirement in 40 CFR part 50, appendix U is
met when the average percentage of days with valid ambient monitoring
data for the three-year design value period is greater than 90% and no
single year is less than 75% data complete. The Baltimore Area has
complete data for the years 2022-2024, as shown in Table 2 in this
document, with the exception of the Glen Burnie (24-003-1003) and
Brooklyn Park (24-003-1004) monitors, as explained below. Preliminary
completeness data for 2025 is also provided in Table 2 in this
document, but as noted, this data has not been certified.\19\
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\19\ Preliminary 2025 ozone data for the Baltimore Area can be
viewed at: <a href="http://www.epa.gov/outdoor-air-quality-data/ozone-watch">www.epa.gov/outdoor-air-quality-data/ozone-watch</a>.
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The Glen Burnie monitor, located in Anne Arundel County, was
discontinued in 2024 because the site land was sold, as described in
MDE's 2024 Annual Network Plan included in the docket for this action.
To replace the Glen Burnie monitor, on April 1, 2024 the Brooklyn Park
monitor, also located in Anne Arundel County and approximately 4 miles
north of the Glen Burnie site, became operational, as described in
MDE's 2025 Annual Network Plan included in the docket for this action.
Based on the monitoring history for these sites and proximity to each
other, the EPA determined that it is reasonable to conclude that the
Glen Burnie and Brooklyn Park sites would not have exceeded the 2015
ozone NAAQS for the 2022-2024 DV.
For each monitor site in the Baltimore Area, except for the Glen
Burnie and Brooklyn Park monitors, the average completeness data
percentage from 2022 through 2024 is greater than 90% and no single
monitor year is below 75% complete.
Table 2--Completeness Data Percentage From 2022 Through 2025 for the Baltimore Area
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2022-2024 2023-2025
Location Site name AQS site ID 2022 2023 2024 Average 2025 \a\ Average \a\
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Anne Arundel County................ Glen Burnie.......... 24-003-1003 98 98 N/A \a\ 65 N/A \a\ 33
Anne Arundel County................ Brooklyn Park........ 24-003-1004 N/A N/A 82 \b\ 27 97 \b\ 60
Baltimore City..................... Lake Montebello...... 24-510-5253 97 96 96 96 98 97
Baltimore County................... Padonia.............. 24-005-1007 97 99 100 99 98 99
Baltimore County................... Essex................ 24-005-3001 98 92 98 96 98 96
Carroll County..................... South Carroll........ 24-013-0001 99 99 99 99 96 98
Harford County..................... Edgewood............. 24-025-1001 97 99 96 97 92 96
Harford County..................... Aldino............... 24-025-9001 98 98 98 98 98 98
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\a\ This data is preliminary and has not been certified. Preliminary 2025 ozone data for the Baltimore Area can be viewed at: <a href="http://www.epa.gov/outdoor-air-quality-data/ozone-watch">www.epa.gov/outdoor-air-quality-data/ozone-watch</a>.
\b\ This data is below the data completeness requirement in 40 CFR part 50, appendix U.
Table 3 in this document shows the annual fourth-highest maximum 8-
hour average ozone concentrations for the Baltimore Area monitors, as
well as the ozone DV for these same monitors based on the average of
the annual fourth-highest daily maximum 8-hour average ozone
concentrations for the 2022-2024 three-year period. As explained in
section II of this document, this data excludes the exceptional event
impacted monitoring days. Preliminary data for year 2025 and the 2023-
2025 DV is also provided; however, the 2025 data has not been
certified.\20\
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\20\ Preliminary 2025 ozone data for the Baltimore Area can be
viewed at: <a href="http://www.epa.gov/outdoor-air-quality-data/ozone-watch">www.epa.gov/outdoor-air-quality-data/ozone-watch</a>.
Table 3--Fourth-Highest 8-Hour Ozone Average Concentration (ppm) and 2022-2024 and 2023-2025 DVs (ppm) for the Baltimore Area
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2022-2024 2023-2025
Location Site name AQS site ID 2022 2023 \a\ 2024 DV \a\ 2025 \b\ DV \a\ \b\
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Anne Arundel County................ Glen Burnie.......... 24-003-1003 0.062 0.065 N/A \c\ 0.063 N/A \c\ 0.065
[[Page 2891]]
Anne Arundel County................ Brooklyn Park........ 24-003-1004 N/A N/A 0.068 \c\ 0.068 0.066 \c\ 0.067
Baltimore City..................... Lake Montebello...... 24-510-5253 0.068 0.070 0.071 0.069 0.067 0.069
Baltimore County................... Padonia.............. 24-005-1007 0.065 0.071 0.071 0.069 0.068 0.070
Baltimore County................... Essex................ 24-005-3001 0.069 0.070 0.070 0.069 0.066 0.068
Carroll County..................... South Carroll........ 24-013-0001 0.064 0.069 0.066 0.066 0.064 0.066
Harford County..................... Edgewood............. 24-025-1001 0.066 0.073 0.073 0.070 0.066 0.070
Harford County..................... Aldino............... 24-025-9001 0.068 0.070 0.070 0.069 0.066 0.068
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\a\ Based on the EPA's concurrence of MD's exceptional events demonstrations, this data excludes the exceptional event-influenced monitoring data on
June 2, June 29-30, and July 17-18, 2023.
\b\ This data is preliminary and has not been certified. Preliminary 2025 ozone data for the Baltimore Area can be viewed at: <a href="http://www.epa.gov/outdoor-air-quality-data/ozone-watch">www.epa.gov/outdoor-air-quality-data/ozone-watch</a>.
\c\ This data is below the data completeness requirement in 40 CFR part 50, appendix U.
The EPA's review of these data indicates that for the 2022-2024 DV,
each of the Baltimore Area monitors have valid data, meet the data
completeness requirements except for the two aforementioned monitors in
Anne Arundel County, and attain the standard of 0.070 ppm, excluding
the exceptional event impacted monitoring days summarized in section II
of this document.\21\ Preliminary data for 2025 indicate that the
Baltimore Area continues to attain the standard. As a result, the EPA
is able to determine that the Baltimore Area met the 2015 8-hour ozone
standard and meets the requirements under the Clean Data Policy for a
CDD.
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\21\ Further details on MDE's exceptional events analysis and
the EPA's concurrence on the demonstrations can be found in the
docket for this regulatory action.
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V. Proposed Action
The EPA is proposing to determine that the Baltimore Area has
attained the 2015 ozone NAAQS and meets the requirements under the
Clean Data Policy for a CDD. This proposed determination is based upon
complete, quality-assured, quality-controlled, and certified ambient
air monitoring data that show the Baltimore Area has monitored
attainment of the 2015 ozone NAAQS for the 2022-2024 DV monitoring
period. This proposed determination is based upon the EPA's evaluation
of and concurrence on portions of MD's exceptional events
demonstrations. Notably, preliminary data from 2025 indicate that the
Baltimore Area continues to attain the standard. As provided in 40 CFR
51.1318, if the EPA finalizes this CDD, it would suspend the
requirements for the Baltimore Area to submit attainment demonstrations
and associated RACM, RFP plans, and contingency measures under CAA
section 172(c)(9), and any other planning state implementation plan
(SIP) revision related to attainment of the 2015 ozone NAAQS for the
Baltimore Area, for so long as the Area continues to attain the
standard.
Finalizing the CDD does not constitute a redesignation of the
Baltimore Area to attainment for the 2015 ozone NAAQS under CAA section
107(d)(3). This action also does not involve approving any maintenance
plan for the Baltimore Area and does not determine that the Baltimore
Area has met all the requirements for redesignation under the CAA,
including that the attainment be due to permanent and enforceable
measures. Therefore, the designation status of the Baltimore Area will
remain nonattainment for the 2015 ozone NAAQS until such time as MD
submits a request for redesignation pursuant to 107(d)(3) of the CAA
and the EPA determines that the Area meets the CAA requirements for
redesignation to attainment and takes action to redesignate the Area.
The EPA also proposes to take final agency action on portions of
exceptional events requests for June 2, June 29-30, and July 17-18,
2023, submitted by MDE on February 2, 2024, and concurred on by the EPA
on November 12, 2025.
The EPA is soliciting public comments on the issues discussed in
this document. These comments will be considered before taking final
action.
V. Statutory and Executive Order Reviews
This rulemaking proposes to make a clean data determination based
on air quality data and would, if finalized, result in the suspension
of certain Federal requirements and would not impose any additional
requirements. 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);
<bullet> Executive Order 14192 (90 FR 9065, February 6, 2025) does
not apply because this action is exempt from review under Executive
Order 12866;
<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, this proposed CDD for the Baltimore Area for the 2015
ozone NAAQS does not have tribal implications as specified by Executive
Order 13175 (65 FR 67249, November 9, 2000), because this action is not
approved to apply in Indian country located in the State, and the EPA
notes that it will not impose substantial direct costs on tribal
governments or preempt tribal law.
[[Page 2892]]
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Nitrogen dioxide, Ozone, Reporting and recordkeeping
requirements, Volatile organic compounds.
Amy Van Blarcom-Lackey,
Regional Administrator, Region III.
[FR Doc. 2026-01314 Filed 1-22-26; 8:45 am]
BILLING CODE 6560-50-P
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