Federal Register / Vol. 88, No. 238 / Wednesday, December 13, 2023 / Proposed Rules 86303 

D. Federalism and Indian Tribal 

Governments 

A rule has implications for federalism 

under Executive Order 13132 

(Federalism), if it has a substantial 

direct effect on the States, on the 

relationship between the National 

Government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government. We have analyzed 

this proposed rule under that Order and 

have determined that it is consistent 

with the fundamental federalism 

principles and preemption requirements 

described in Executive Order 13132. 

Also, this proposed rule does not have 

tribal implications under Executive 

Order 13175 (Consultation and 

Coordination with Indian Tribal 

Governments) because it would not 

have a substantial direct effect on one or 

more Indian tribes, on the relationship 

between the Federal Government and 

Indian tribes, or on the distribution of 

power and responsibilities between the 

Federal Government and Indian tribes. 

If you believe this proposed rule has 

implications for federalism or Indian 

tribes, please contact the person listed 

in the FOR FURTHER INFORMATION

CONTACT section. 

E. Unfunded Mandates Reform Act 

The Unfunded Mandates Reform Act 

of 1995 (2 U.S.C. 1531–1538) requires 

Federal agencies to assess the effects of 

their discretionary regulatory actions. In 

particular, the Act addresses actions 

that may result in the expenditure by a 

State, local, or tribal government, in the 

aggregate, or by the private sector of 

$100,000,000 (adjusted for inflation) or 

more in any one year. Though this 

proposed rule will not result in such an 

expenditure, we do discuss the effects of 

this proposed rule elsewhere in this 

preamble. 

F. Environment 

We have analyzed this proposed rule 

under Department of Homeland 

Security Management Directive 023–01, 

Rev.1, associated implementing 

instructions, and Environmental 

Planning Policy COMDTINST 5090.1 

(series), which guide the Coast Guard in 

complying with the National 

Environmental Policy Act of 1969 

(NEPA) (42 U.S.C. 4321–4370f). The 

Coast Guard has determined that this 

action is one of a category of actions that 

do not individually or cumulatively 

have a significant effect on the human 

environment. This proposed rule 

promulgates the operating regulations or 

procedures for drawbridges. Normally 

such actions are categorically excluded 

from further review, under paragraph 

L49, of chapter 3, table 3–1 of the U.S. 

Coast Guard Environmental Planning 

Implementation Procedures. 

Neither a Record of Environmental 

Consideration nor a Memorandum for 

the Record are required for this 

proposed rule. We seek any comments 

or information that may lead to the 

discovery of a significant environmental 

impact from this proposed rule. 

V. Public Participation and Request for 

Comments 

We view public participation as 

essential to effective rulemaking and 

will consider all comments and material 

received during the comment period. 

Your comment can help shape the 

outcome of this rulemaking. If you 

submit a comment, please include the 

docket number for this rulemaking, 

indicate the specific section of this 

document to which each comment 

applies, and provide a reason for each 

suggestion or recommendation. 

Submitting comments. We encourage 

you to submit comments through the 

Federal Decision-Making Portal at 

https://www.regulations.gov. To do so, 

go to https://www.regulations.gov, type 

USCG–2023–0912 in the search box and 

click ‘‘Search.’’ Next, look for this 

document in the Search Results column, 

and click on it. Then click on the 

Comment option. If your material 

cannot be submitted using https://

www.regulations.gov, contact the person 

in the FOR FURTHER INFORMATION

CONTACT section of this document for 

alternate instructions. 

Viewing material in docket. To view 

documents mentioned in this proposed 

rule as being available in the docket, 

find the docket as described in the 

previous paragraph, and then select 

‘‘Supporting & Related Material’’ in the 

Document Type column. Public 

comments will also be placed in our 

online docket and can be viewed by 

following instructions on the https://

www.regulations.gov Frequently Asked 

Questions web page. Also, if you go to 

the online docket and sign up for email 

alerts, you will be notified when 

comments are posted, or a final rule is 

published of any posting or updates to 

the docket. 

We review all comments received, but 

we will only post comments that 

address the topic of the proposed rule. 

We may choose not to post off-topic, 

inappropriate, or duplicate comments 

that we receive. 

Personal information. We accept 

anonymous comments. Comments we 

post to https://www.regulations.gov will 

include any personal information you 

have provided. For more about privacy 

and submissions in response to this 

document, see DHS’s eRulemaking 

System of Records notice (85 FR 14226, 

March 11, 2020). 

List of Subjects in 33 CFR Part 117 

Bridges. 

For the reasons discussed in the 

preamble, the Coast Guard proposes to 

amend 33 CFR part 117 as follows: 

PART 117—DRAWBRIDGE 

OPERATION REGULATIONS 

■ 1. The authority citation for part 117 

continues to read as follows: 

Authority: 33 U.S.C. 499; 33 CFR 1.05–1; 

DHS Delegation No. 00170.1, Revision No. 

01.3. 

■ 2. [From the date of publication in the 

Federal Register], through 11:59 p.m. on 

March 31, 2025, § 117.647(e) is 

temporarily added to read as follows: 

§ 117.647 Saginaw River. 

* * * * * 

(e) The draw of the Independence 

Bridge, mile 3.88, over the Saginaw 

River, will require a 2-hour advance 

notice of arrival to be given to move 

barges away from the draw to allow 

vessels to pass through the bridge from 

April 24, 2024, through November 30, 

2024, and the bridge need not open for 

the passage of vessels from December 1, 

2024, through March 31, 2025. 

Jonathan Hickey, 

Rear Admiral, U.S. Coast Guard, Commander, 

Ninth Coast Guard District. 

[FR Doc. 2023–27385 Filed 12–12–23; 8:45 am] 

BILLING CODE 9110–04–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R04–OAR–2021–0367; FRL–11573– 

01–R4] 

Air Plan Approval; Alabama; 

Birmingham Limited Maintenance Plan 

for the 2006 24-Hour PM2.5 NAAQS 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to approve a 

State implementation plan (SIP) 

revision submitted by the State of 

Alabama, through the Alabama 

Department of Environmental 

Management (ADEM), via a letter dated 

February 2, 2021. The SIP revision 

includes the 2006 24-hour fine 

particulate matter (PM2.5) national 


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1EPA notes the Agency received the submittal on 

February 17, 2021. 

2See 78 FR 3086 at 3090, 3121 (January 15, 2013). 

3See id.; ‘‘Fact Sheet Final Revisions to the 

National Ambient Air Quality Standards for Particle 

Pollution (Particulate Matter),’’ September 21, 2006, 

accessible at: https://www.epa.gov/sites/ 

production/files/2016-04/documents/20060921_

standards_factsheet.pdf; 71 FR 61144, 61145 

(October 17, 2006). 

4 In the same rulemaking, EPA promulgated an 

annual standard at a level of 15.0 micrograms per 

cubic meter (mg/m3), based on a 3-year average of 

annual mean PM2.5 concentrations. See 62 FR 

38652. 

5On January 15, 2013, and December 18, 2020, 

EPA retained the 24-hour primary and secondary 

PM2.5 NAAQS at the 2006 level of 35 mg/m3. See 

78 FR 3086 and 85 FR 82684. 

ambient air quality standards (NAAQS) 

Limited Maintenance Plan (LMP) for the 

Birmingham, Alabama maintenance area 

(Birmingham Area or Area). The 

Birmingham 2006 24-hour PM2.5

maintenance area is comprised of 

Jefferson County, Shelby County, and a 

portion of Walker County. EPA is 

proposing to approve the Birmingham 

Area LMP because it provides for the 

maintenance of the 2006 24-hour PM2.5

NAAQS within the Birmingham Area 

through the end of the second 10-year 

portion of the maintenance period in 

2034. The effect of this action would be 

to incorporate into the Alabama SIP 

certain commitments related to 

maintenance of the 2006 24-hour PM2.5

NAAQS in the Birmingham Area, 

making them federally enforceable. EPA 

is also starting the adequacy process, 

consistent with requirements in the 

transportation conformity rule, for this 

LMP. 

DATES: Comments must be received on 

or before January 12, 2024. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R04– 

OAR–2021–0367 at https://

www.regulations.gov. Follow the online 

instructions for submitting comments. 

Once submitted, comments cannot be 

edited or removed from Regulations.gov. 

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. 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: 

Dianna Myers, Air Regulatory 

Management Section, Air Planning and 

Implementation Branch, Air and 

Radiation Division, U.S. Environmental 

Protection Agency, Region 4, 61 Forsyth 

Street SW, Atlanta, Georgia 30303–8960. 

The telephone number is (404) 562– 

9207. Ms. Myers can also be reached via 

electronic mail at myers.dianna@

epa.gov. 

SUPPLEMENTARY INFORMATION: 

Table of Contents 

I. Summary of EPA’s Action 

II. Background 

III. Alabama’s SIP Submittal 

IV. EPA’s Evaluation of Alabama’s SIP 

Submittal 

A. Attainment Emissions Inventory 

B. Maintenance Demonstration 

1. Evaluation of PM2.5 Air Quality Levels 

2. Stability of PM2.5 Levels 

C. Monitoring Network and Verification of 

Continued Attainment 

D. Contingency Plan 

E. Conclusion 

V. Transportation Conformity 

VI. General Conformity 

VII. Proposed Action 

VIII. Statutory and Executive Order Reviews 

I. Summary of EPA’s Action 

In accordance with the Clean Air Act 

(CAA or Act), EPA is proposing to 

approve the Birmingham Area LMP for 

the 2006 24-hour PM2.5 NAAQS, 

adopted by ADEM on February 2, 2021, 

and submitted by ADEM as a revision to 

the Alabama SIP under a cover letter 

with the same date.1 The Birmingham 

Area LMP is designed to maintain the 

2006 24-hour PM2.5 NAAQS within the 

Birmingham Area through the end of the 

second 10-year portion of the 

maintenance period beyond 

redesignation. EPA is proposing to 

approve the plan because it meets all 

applicable requirements under CAA 

sections 110 and 175A. As a general 

matter, the Birmingham Area LMP relies 

on the same control measures and 

similar contingency measures to 

maintain the 2006 24-hour PM2.5

NAAQS during the second 10-year 

portion of the maintenance period as the 

maintenance plan submitted by ADEM 

for the first 10-year period, which is not 

a limited maintenance plan. 

II. Background 

Fine particulate matter, particulate 

matter with an aerodynamic diameter of 

2.5 microns or less, can be emitted 

directly into the atmosphere as a solid 

or liquid particle (‘‘primary PM2.5’’ or 

‘‘direct PM2.5’’) or can be formed in the 

atmosphere as a result of various 

chemical reactions among precursor 

pollutants such as nitrogen oxides 

(NOX), sulfur oxides, volatile organic 

compounds (VOC), and ammonia (NH3) 

(‘‘secondary PM2.5’’).2 Epidemiological 

studies have shown statistically 

significant correlations between 

elevated levels of PM2.5 and premature 

mortality. Other important health effects 

associated with PM2.5 exposure include 

aggravation of respiratory and 

cardiovascular disease, changes in lung 

function, and increased respiratory 

complications, contributing to 

premature mortality and increased 

hospital admissions and emergency 

room visits. Individuals particularly 

sensitive to PM2.5 exposure include 

older adults, people with heart and lung 

disease, and children.3

On July 18, 1997, EPA promulgated 

the first air quality standards for PM2.5. 

See 62 FR 38652. EPA promulgated a 

24-hour standard of 65 mg/m3, based on 

a 3-year average of the 98th percentile 

of 24-hour concentrations.4 On October 

17, 2006, EPA revised the 24-hour 

NAAQS to 35 mg/m3, based again on the 

3-year average of the 98th percentile of 

24-hour concentrations. See 71 FR 

61144.5 Under EPA regulations at 40 

CFR part 50, the primary and secondary 

2006 24-hour PM2.5 NAAQS are attained 

when the 3-year average of the 98th 

percentile of 24-hour concentration, as 

determined in accordance with 40 CFR 

part 50, Appendix N, is less than or 

equal to 35 mg/m3 at all relevant 

monitoring sites in the subject area over 

a 3-year period. 

Following promulgation of a new 

revised NAAQS, EPA is required by the 

CAA to designate areas throughout the 

nation as attaining or not attaining the 

NAAQS. On November 13, 2009, EPA 

promulgated designations for the 2006 

24-hour PM2.5 NAAQS, designating the 

Birmingham Area, which includes 

Jefferson County, Shelby County, and a 

portion of Walker County, as 

nonattainment for the 2006 24-hour 

PM2.5 NAAQS based upon air quality 

data for calendar years 2006 through 

2008. See 74 FR 58688. Under the CAA, 

States are also required to adopt and 

submit SIPs to implement, maintain, 

and enforce the NAAQS in designated 

nonattainment areas and throughout the 

State. 

A State may submit a request to 

redesignate a nonattainment area that is 

attaining the NAAQS, and, if the area 

has met the required criteria described 

in section 107(d)(3)(E) of the CAA, EPA 

may approve the redesignation to 


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Federal Register / Vol. 88, No. 238 / Wednesday, December 13, 2023 / Proposed Rules 86305 

6Section 107(d)(3)(E) of the CAA sets out the 

requirements for redesignating a nonattainment area 

to attainment. They include attainment of the 

NAAQS, full approval of the applicable SIP 

pursuant to CAA section 110(k), determination that 

improvement in air quality is a result of permanent 

and enforceable reductions in emissions, 

demonstration that the state has met all applicable 

section 110 and part D requirements, and a fully 

approved maintenance plan under CAA section 

175A. 

7See Memorandum from John Calcagni, 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 guidance is available in the docket 

for this proposed rulemaking. 

8The 24-hour PM2.5 design value for a monitoring 

site is the 3-year average of the annual 98thpercentile 24-hour average PM2.5 concentrations. 

The design value for a PM2.5 nonattainment area is 

the highest design value of any monitoring site in 

the area. 

9See ‘‘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; 

‘‘Limited Maintenance Plan Option for Moderate 

PM10 Nonattainment Areas,’’ from Lydia Wegman, 

OAQPS, dated August 9, 2001 (2001 PM10 LMP 

Guidance); and Guidance on the Limited 

Maintenance Plan Option for Moderate PM2.5

Nonattainment Areas and PM2.5 Maintenance Areas 

(2022 PM2.5 LMP Guidance). Copies of these 

guidance memoranda can be found in the docket for 

this proposed rulemaking. 

10Prior memos addressed unclassifiable areas 

under the 1-hour ozone NAAQS, nonattainment 

areas for the PM10 (particulate matter with an 

aerodynamic diameter less than 10 microns) 

NAAQS, and nonattainment areas for the carbon 

monoxide (CO) NAAQS. 

11See, e.g., 79 FR 41900 (July 18, 2014) (approval 

of second ten-year LMP for Grant County 1971 

sulfur dioxide (SO2) maintenance area). 

12As discussed further below, ADEM prepared its 

second maintenance plan submission following the 

2001 PM10 LMP Guidance. 

13A copy is available in the docket for this 

proposed action and also available via https://

www.epa.gov/system/files/documents/2023-03/ 

PM%202.5%20Limited%20Maintenance

%20Plan%20Guidance.pdf. 

attainment for the area.6 One of the 

criteria for redesignation is to have an 

approved maintenance plan under CAA 

section 175A. The maintenance plan 

must demonstrate that the area will 

continue to maintain the NAAQS for the 

period extending 10 years after 

redesignation, and it must contain such 

additional measures as necessary to 

ensure maintenance and such 

contingency provisions as necessary to 

assure that violations of the NAAQS 

will be promptly corrected. Eight years 

after the effective date of redesignation, 

the State must also submit a second 

maintenance plan to ensure ongoing 

maintenance of the NAAQS for an 

additional ten years pursuant to CAA 

section 175A(b) (i.e., ensuring 

maintenance for 20 years after 

redesignation). 

In 2009, the Birmingham Area was 

designated as nonattainment for the 

2006 24-hour PM2.5 NAAQS. On June 

17, 2010, ADEM submitted to EPA a 

request to redesignate the Birmingham 

Area to attainment for the 2006 24-hour 

PM2.5 NAAQS. This submittal included 

a plan to provide for maintenance of the 

2006 24-hour PM2.5 NAAQS in the 

Birmingham Area through 2024 as a 

revision to the Alabama SIP. On 

September 20, 2010, EPA issued a clean 

data determination under the Agency’s 

Clean Data Policy based upon complete, 

quality assured, quality controlled, and 

certified ambient air monitoring data for 

the years 2007–2009 showing that the 

Birmingham Area had monitored 

attainment of the 2006 24-hour PM2.5

NAAQS. See 75 FR 57186. 

Subsequently, on January 25, 2013, EPA 

approved the Birmingham Area’s 

maintenance plan and the State’s 

request to redesignate the Birmingham 

Area to attainment for the 2006 24-hour 

PM2.5 NAAQS. See 78 FR 5306. 

EPA has published long-standing 

guidance for States on developing 

maintenance plans.7 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 projected 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). See Calcagni Memo at 9. 

EPA clarified in subsequent guidance 

memos that certain areas could meet the 

CAA section 175A requirement to 

provide for maintenance by showing 

that the area was unlikely to violate the 

NAAQS in the future, using information 

such as the area’s design value 8 being 

significantly below the standard and the 

area having a historically stable design 

value.9 EPA refers to a maintenance 

plan containing this streamlined 

demonstration as an LMP, and in 

guidance, EPA has discussed certain 

criteria that it intends to evaluate, 

including consistency with EPA 

regulations along with other information 

as is relevant, in determining if this 

option is appropriate for an area. 

EPA has interpreted CAA section 

175A as permitting the LMP option 

because section 175A of the Act does 

not define how areas may provide for 

maintenance, 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 EPA’s LMP 

guidance, States seeking an LMP must 

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, a 

State seeking an LMP as its section 

175A maintenance plan must submit it 

as a revision to its SIP, with all 

attendant notice and comment 

procedures. While the LMP guidance 

memoranda were originally written with 

respect to certain NAAQS,10 EPA has 

extended the LMP interpretation of 

section 175A to certain other NAAQS 

and pollutants not specifically covered 

by the previous guidance memos.11

At the time ADEM was developing its 

February 2, 2021, SIP revision, EPA had 

not developed specific LMP guidance 

for PM2.5, and ADEM consulted with the 

Agency in extending the rationale from 

the 2001 PM10 LMP Guidance, which 

was written for particulate matter with 

an aerodynamic diameter of 10 microns 

or less (PM10), to the PM2.5 maintenance 

plan.12 Accordingly, ADEM prepared its 

second maintenance plan submission in 

accordance with the 2001 PM10 LMP 

Guidance. Since the time of the 

February 2, 2021, submittal, EPA has 

released LMP guidance for PM2.5. 

Specifically, on October 27, 2022, EPA 

published clarifying guidance that 

focuses on the distinctions that are 

relevant specifically for PM2.5 LMPs for 

Moderate PM2.5 Nonattainment and 

PM2.5 Maintenance Areas.13 The 2022 

PM2.5 LMP Guidance applies the 2001 

Limited Maintenance Plan Option for 

Moderate PM10 Nonattainment Areas 

guidance for PM2.5 LMP submissions, 

except for the specific topics where the 

2001 guidance is superseded. Therefore, 

EPA has evaluated the February 2, 2021, 

submittal in light of the criteria 

discussed in the 2022 PM2.5 LMP 

Guidance, as well as the relevant 

statutory and regulatory requirements. 

EPA is proposing to approve the 

Birmingham Area LMP because the 

State has made a showing, consistent 

with EPA’s current PM2.5 LMP guidance, 

that the Birmingham Area’s PM2.5

concentrations are well below the 2006 

24-hour PM2.5 NAAQS and have been 

historically stable, and that it has met 

the other maintenance plan 

requirements. EPA’s evaluation of the 

Birmingham Area LMP is presented in 

Section IV of this notice of proposed 

rulemaking (NPRM). 


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14See 79 FR 23414 (April 28, 2014). The February 

17, 2021, submittal lists this as ‘‘Tier IV,’’ which is 

an error, as only Tier 3 standards have been set for 

on-road mobile source emissions standards. EPA 

understands this to be in reference to the latest 

emissions standards, referred to as ‘‘Tier 3.’’ 

15See, e.g., 63 FR 57355 (October 27, 1998). 

16See also 78 FR 5306 (January 25, 2013), 76 FR 

70091 (November 10, 2011), and the submittal at 

docket ID EPA–R04–OAR–2011–0043. 

17See also EPA docket EPA–HQ–OAR–2017– 

0003 and item EPA–HQ–OAR–2017–0003–0213 

supporting EPA’s air quality designations for the 

2010 1-hour SO2 NAAQS. 

18See Calcagni Memo. 

19 Documentation and data for the 2017 NEI can 

be accessed via the following website: https://

www.epa.gov/air-emissions-inventories/2017- 

national-emissions-inventory-nei-data. 

III. Alabama’s SIP Submittal 

Under CAA section 175A(b), States 

must submit a revision to the first 

maintenance plan eight years after 

redesignation to provide for 

maintenance of the NAAQS for ten 

additional years following the end of the 

first 10-year period. Accordingly, on 

February 2, 2021, Alabama submitted a 

second maintenance plan for the 

Birmingham Area that shows that the 

Area is expected to remain in 

attainment of the 2006 24-hour PM2.5

NAAQS through 2034, i.e., through the 

end of the full 20-year maintenance 

period. 

In recognition of the continuing 

record of air quality monitoring data 

showing ambient 24-hour PM2.5

concentrations in the Birmingham Area 

well below the 2006 24-hour PM2.5

NAAQS, ADEM chose the LMP option 

for the development of a second 2006 

24-hour PM2.5 NAAQS maintenance 

plan. On February 2, 2021, ADEM 

adopted the second 10-year 

maintenance plan for the 2006 24-hour 

PM2.5 NAAQS and submitted the 

Birmingham Area LMP to EPA as a 

revision to the Alabama SIP. 

The February 2, 2021, submittal 

includes the LMP, air quality data and 

other information demonstrating 

qualification for the LMP, emissions 

inventory information, and appendices, 

as well as certification of adoption of 

the plan by ADEM. Appendices to the 

plan include a copy of the 2001 PM10

LMP Guidance, supplemental 

information on ADEM’s mobile source 

emissions analysis, emissions inventory 

development data, and qualifying 

calculations in accordance with the 

2001 PM10 LMP Guidance. The 

submittal also includes documentation 

of notice, hearing, and public 

participation prior to adoption of the 

plan by ADEM on February 2, 2021. The 

Birmingham Area LMP relies on the 

same emission reduction strategy and 

other already-implemented measures as 

the Area’s first 10-year maintenance 

plan, which provides for the 

maintenance of the 2006 24-hour PM2.5

NAAQS through 2024. Specifically, the 

Birmingham Area LMP relies on the 

following measures: the continuation of 

programs such as the local Jefferson 

County and Shelby County burn bans, 

prioritizing funding for diesel emissions 

reduction projects within the 

Birmingham Area, continued 

implementation of Federal measures (for 

example, Tier 3 Motor Vehicle Emission 

and Fuel Standards,14 and interstate 

transport rules 15), and emission 

reductions achieved and documented 

for the first CAA section 175A 

maintenance plan.16 Since Alabama 

submitted its maintenance plan for the 

first 10-year portion of the maintenance 

period, other changes that have 

decreased PM2.5 and precursor 

emissions in the Area have taken place, 

as noted in the February 2, 2021, 

submittal. Examples include the 

permanent shutdown of Units 1–5 at the 

Tennessee Valley Authority’s Colbert 

Plant, the permanent shutdown of 

Alabama Power Company’s Plant 

Gorgas, the installation of a baghouse 

with an electrostatic precipitator at 

Alabama Power Company’s Plant 

Gaston, and the conversion of the coalfired units to natural gas at Alabama 

Power Company’s Greene County Steam 

Plant.17

IV. EPA’s Evaluation of Alabama’s SIP 

Submittal 

EPA has reviewed the Birmingham 

Area LMP, which is designed to 

maintain the 2006 24-hour PM2.5

NAAQS within the Birmingham Area 

through the end of the 20-year period 

beyond redesignation, as required under 

CAA section 175A(b). The following is 

a summary of EPA’s interpretation of 

the section 175A requirements 18 and 

EPA’s evaluation of how each 

requirement is met. 

A. Attainment Emissions Inventory 

For maintenance plans, a State should 

develop a comprehensive, accurate 

inventory of actual emissions for an 

attainment year to identify the level of 

emissions which is sufficient to 

maintain the NAAQS. A State should 

develop this inventory consistent with 

EPA’s most recent guidance on 

emissions inventory development. For 

the 24-hour PM2.5 NAAQS, the 

inventory should be based on 

representative daily emissions of direct 

PM2.5 and precursor emissions, 

including SO2, NOX, VOC, and NH3. 

The Birmingham Area LMP includes a 

PM2.5 attainment inventory for the 

Birmingham Area with emissions from 

2017. Table 1 presents a summary of the 

inventory for 2017 contained in the 

LMP for PM2.5 and precursor emissions. 

TABLE 1—2017 SO2, NOX, PM2.5, VOC, AND NH3 EMISSIONS FOR THE BIRMINGHAM AREA

[Tons/day] 

Point 

source 

Non-point 

source 

On-road 

mobile source 

Nonroad 

mobile source Event Total 

SO2 .......................................................... 52.95 0.5 0.27 0.02 0.14 53.88 

NOX .......................................................... 73.06 10.02 27.96 9.44 0.32 120.8 

PM2.5 ........................................................ 9.0 13.94 0.80 1.07 1.17 25.98 

VOC ......................................................... 9.4 171.17 12.91 7.75 2.99 204.22 

NH3 .......................................................... 0.40 1.77 0.95 0.02 0.16 3.30 

The Attainment Emissions Inventory 

section of the Birmingham Area LMP 

describes the methods, models, and 

assumptions used to develop the 

attainment inventory. As described in 

the Attainment Emissions Inventory 

section of the LMP, ADEM relied on the 

2017 National Emissions Inventory 

(NEI) for point source, non-point (or 

area source), and event emissions 

(which typically consist of activities 

such as wildfires), except as described 

below.19

Nonroad mobile source emissions 

were, in part, estimated using the latest 

version of the EPA’s motor vehicle 

emissions model, MOVES3 (which 

provides the ability to estimate nonroad 

emissions from agricultural, 

commercial, mining, industrial, and 


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20EPA developed emissions for these sectors 

based on AP–42 emissions factors, and information 

supplied by the Eastern Regional Technical 

Advisory Committee for locomotives and Federal 

Aviation Administration’s Aviation Environmental 

Design Tool. See 2017 National Emissions 

Inventory: January 2021 Updated Release, 

Technical Support Document available via the 

following website: https://www.epa.gov/airemissions-inventories/2017-national-emissionsinventory-nei-technical-support-document-tsd. 

21See 2022 PM2.5 LMP Guidance; see also 2001 

p.m.10 LMP Guidance; ‘‘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; and ‘‘Limited Maintenance Plan Option 

for Nonclassifiable CO Nonattainment Areas’’ from 

Joseph Paisie, OAQPS, dated October 6, 1995. 22 40 CFR 58.11(e) requires agencies to assess data 

from Class III PM2.5 Federal equivalent methods 

(FEMs) operating in their network alongside 

collocated Federal reference methods (FRMs) in 

accordance with table C–4 to subpart C of 40 CFR 

part 53. The Jefferson County Department of Health 

(JCDH) submitted a demonstration on November 28, 

2022, showing that the FEM operating at AQS site 

01–073–0023 did not meet these performance 

criteria and therefore should not be used for 

comparison to the NAAQS. EPA approved this 

demonstration on February 2, 2023. As stated in 

EPA’s approval (which is included in the docket for 

this proposed rulemaking), JCDH included its 

demonstration and EPA’s approval thereof in the 

2023 network plan that was posted for public 

comment. See the docket for this proposed 

rulemaking for more information. 

23For more information on the air quality data, 

see additional information in the document titled 

‘‘Technical Support Document for EPA’s Notice of 

Proposed Rulemaking: Air Plan Approval; Alabama; 

Birmingham Limited Maintenance Plan for the 2006 

24-Hour PM2.5 NAAQS’’ (Birmingham TSD) with 

the file name ‘‘AL–124 TSD_Alabama Limited 

Maintenance Plan for 2006 PM2.5.pdf’’ in the docket 

for this proposed rulemaking. 

recreational equipment, and commercial 

and residential lawn and garden 

equipment, among others). Locomotives, 

aircraft, and marine nonroad sources are 

not included in MOVES, and ADEM 

relied on EPA-generated emissions for 

these sectors.20 ADEM estimated onroad mobile source emissions using 

MOVES3 and local data such as vehicle 

type, activity, and vehicle speeds from 

the Birmingham metropolitan planning 

organization (MPO) to estimate 

vehicular emissions for 2017. ADEM’s 

estimates for vehicles reflect emissions 

inventories and ancillary data files used 

for emissions modeling, as well as the 

meteorological, initial condition, and 

boundary condition files needed to run 

the air quality model. 

Based on EPA’s review of the 

methods, models, and assumptions used 

by Alabama to develop the inventory, as 

well as EPA’s review of the 2017 daily 

emissions data, EPA proposes to find 

that the Birmingham Area LMP includes 

a comprehensive, accurate inventory of 

actual PM2.5 and precursor emissions in 

attainment year 2017 and proposes to 

conclude that this is acceptable for the 

purposes of a maintenance plan under 

CAA section 175A(b). 

B. Maintenance Demonstration 

The maintenance demonstration 

requirement is considered to be satisfied 

in an LMP if the State can provide 

sufficient weight of evidence indicating 

that air quality in the area is well below 

the level of the NAAQS, that past air 

quality trends have been shown to be 

stable, and that the probability of the 

area experiencing a violation during the 

second 10-year maintenance period is 

low.21 These criteria are evaluated 

below with regard to the Birmingham 

Area. As noted in Section II of this 

NPRM, EPA has evaluated ADEM’s 

submittal and, considering the 

submittal’s contents and EPA’s 

conclusions based thereon, finds the 

LMP to be consistent with EPA’s current 

LMP guidance for PM2.5 Maintenance 

Areas. Although ADEM developed the 

Birmingham Area LMP in accordance 

with the 2001 PM10 LMP Guidance, the 

LMP is nonetheless consistent with the 

portions of the 2022 PM2.5 LMP 

Guidance that superseded the 2001 

PM10 LMP Guidance. 

1. Evaluation of PM2.5 Air Quality 

Levels 

To attain the 2006 24-hour PM2.5

NAAQS, the three-year average of the 

98th percentile 24-hour average PM2.5

concentrations (design value) at each 

monitor within an area must not exceed 

35 mg/m3. Table 2 includes the Areawide monitor design values for the 2006 

24-hour PM2.5 NAAQS from EPA’s Air 

Quality System (AQS) for the period 

2015–2019, which covers the overall 

period from 2013–2019.22

TABLE 2—2015–2019 DESIGN VALUES (DV) (μg/m3) FOR THE 2006 24-HOUR PM2.5 NAAQS AT MONITORING SITES IN

THE BIRMINGHAM AREA abc

AQS site ID Location 2013–2015 2014–2016 2015–2017 2016–2018 2017–2019 

01–073–0023 ...................... North Birmingham .............. 23 23 22 21 d 20 

01–073–1005 ...................... McAdory ............................. e 20 e 18 18 17 18 

01–073–1010 ...................... Leeds .................................. 20 19 17 18 18 

01–073–2003 ...................... Wylam ................................ 20 19 18 18 17 

aThe Metropolitan Statistical Area (MSA) is required to have a minimum of three PM2.5 monitoring sites. The MSA still maintains five regulatory PM2.5 monitoring sites, offering adequate coverage of the MSA. bSome of the data in this table is different than that transmitted in the February 2, 2021, submittal. EPA queried AQS to substitute the data for 

the 2014–2016 design values for the Leeds, McAdory, and Wylam sites and understands these differences to be the result of typographical errors. cThere is one additional monitor in Jefferson County recording PM2.5 data. The Arkadelphia/Near Road site in AQS with ID 01–073–2059, 

identified as the West Birmingham monitor in the February 2, 2021, SIP revision, began recording data to AQS in calendar year 2014, so 2014– 

2016 comprises the first period with three full years of data to calculate a DV. However, until Quarter 3 of 2020, data collected were incomplete 

because the Federal reference method monitor was operating on a 1-in-6-day sampling frequency rather than a 1-in-3-day sampling frequency 

as required by 40 CFR 58.12(d). The incomplete data means that resulting calculated DVs are invalid. Accordingly, those data are not presented 

here or included in further analysis. dThe 2017–2019 DV for the North Birmingham site differs from the DV submitted in the February 2, 2021, SIP revision because the updated 

value presented in Table 2 reflects EPA-approved exclusion of data from one monitor at the site and utilization of data recorded at a collocated 

monitor for NAAQS-comparison purposes. eThese data are incomplete due to the need to relocate the monitor in the first quarter of 2014, and the resulting DVs for 2013–2015 and 

2014–2016 are invalid. 

From the available data in Table 2, the 

representative complete DV for the 

Birmingham Area was the North 

Birmingham monitor DV for each threeyear period. The highest complete DV in 

this time period is 23 mg/m3, which is 

66% of the 24-hour NAAQS. The most 

recent official DVs are for 2020–2022 

and are as follows: North Birmingham, 

17 mg/m3; McAdory, 17 mg/m3; Leeds, 18 

mg/m3; and Wylam, 18 mg/m3. These 

most recent data are slightly lower than 

those presented in Table 2 and continue 

to show the general downward trend.23


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24See the February 2, 2021, submittal and the 

Birmingham TSD for more information on ADEM’s 

calculations. 

25See the Birmingham TSD for additional 

information. 

To qualify for the LMP option 

pursuant to EPA’s 2022 PM2.5 LMP 

Guidance, a State must analyze the 

design value (DV) trends to determine a 

critical design value (CDV), which is 

typically calculated based on the fiveyear average of the most recent DVs for 

the area and the statistical variation of 

the average DV. If each site in the 

maintenance area has an average design 

value (ADV) that is less than the CDV, 

it would demonstrate that the area has 

PM2.5 concentrations that will likely 

remain below the level of the standard 

in the future. 

The ADVs are used to determine the 

CDV for the area. See Table 3 for 

relevant equations. 

EPA notes that ADEM made use of a 

different calculation of the standard 

deviation than that shown in Table 3, 

which affects the calculations of the CV 

and the CDV. Specifically, ADEM made 

use of a population standard deviation, 

which treats the seven-year period and 

five resultant DVs as the entire set of 

available data needed to assess the 

stability of the DVs over time. The 2001 

PM10 LMP Guidance, which ADEM 

followed when it developed the LMP, 

did not specify the approach for 

determining the standard deviation of 

DV data analyzed. However, the sevenyear period and five resultant DVs used 

to assess the stability of the DVs over 

time are a subset, or sample, of all of the 

available historical data. Therefore, EPA 

considers the sample standard 

deviation, presented in Table 3, to be 

the most appropriate approach for 

determining the variability in the data.24

ADEM calculated the CDV across the 

entire area to be 33.3 mg/m3 for the 

Birmingham Area, and the ADV across 

the Area to be 22.2 mg/m3. ADEM 

determined the CDV and ADV based on 

the controlling, or highest, DV across all 

monitoring sites in the Birmingham 

Area for each three-year period. EPA 

clarified in the 2022 PM2.5 LMP 

Guidance that the CDV approach is 

specifically intended to be conducted 

for each monitoring site in an area. 

Therefore, EPA has included the CDV 

and ADV calculations across each site in 

Table 4. 

TABLE 4—STATISTICAL ANALYSIS OF 2015–2019 DVS AT MONITORING SITES IN THE BIRMINGHAM AREA

AQS site ID Location ADV 

(μg/m3) S CV CDV (μg/m3) 

CDV–ADV 

(μg/m3) 

01–073–0023 ...................... North Birmingham .............. 21.8 1.30 0.060 32.1 10.3 

01–073–1005 ...................... McAdory ............................. 18.2 1.10 0.060 32.0 13.8 

01–073–1010 ...................... Leeds .................................. 18.4 1.14 0.062 32.0 13.6 

01–073–2003 ...................... Wylam ................................ 18.4 1.14 0.062 32.0 13.6 

EPA has calculated the CDVs over this 

time and across the Area, with the 

highest CDV being 32.1 mg/m3 at the 

North Birmingham site and the lowest 

being 32.0 mg/m3 at the other sites. The 

ADVs across the Birmingham Area in 

Table 4 are far below the CDVs, with the 

lowest margin between these values 

shown as 10.3 mg/m3, so the Area 

qualifies for the LMP based on this 

portion of the analysis. 

The most recent DVs for 2018–2020, 

2019–2021, and 2020–2022, available 

through EPA’s AQS, do not alter the 

conclusions of the analysis conducted 

based on the 2015–2019 DVs. The 

available margins between the updated 

CDV and ADV for the 2018–2022 DVs 

covering the seven-year period from 

2016–2022 for each site are as follows: 

North Birmingham, 11.8 mg/m3; 

McAdory, 15.9 mg/m3; Leeds, 15 mg/m3; 

and Wylam, 15.9 mg/m3. These most 

recent margins between the calculated 

CDVs and ADVs are greater than those 

presented in Table 4, meaning the data 

at the monitoring sites more easily meet 

the criteria in the 2022 PM2.5 LMP 

Guidance.25

The 2022 PM2.5 LMP Guidance 

describes circumstances in which an 

LMP may be appropriate for a first and/ 

or second 10-year maintenance plan. 


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Table 3 - Eli~ibility Calculations Used to Redetermine Qualification for the LMP 

Standard Deviation ( cr) 

Coefficient of Variation (CV)* 

Critical Design Value (CDV)* 

ADV= Average of 3-year design values. 

DV = Design value. 

NAAQS = Applicable standard (35 μg/m3). 

L (x;-ADV)2 

(J = n-1 

CV= a/ADV 

CDV = NAAQS/(1 +(tc * CV)) 

fc = Critical t-value (based on the one-tail student's t-distribution, at a significance level of 

0.10). 

x; = A given three-year period design value for the area. 

n = The total number of design values evaluated, which in this case is jive. 

*See 2022 Guidance on the Limited Maintenance Plan Option for Moderate PM2.s 

Nonattainment Areas and PM2.5 Maintenance Areas (p. 7). 
Federal Register / Vol. 88, No. 238 / Wednesday, December 13, 2023 / Proposed Rules 86309 

26A copy of the August 9, 2023, conformity 

determination is included in the docket for more 

information. 

27ADEM completed additional motor vehicle 

emissions analysis based on the 2001 PM10 LMP 

Guidance. This analysis is not required for the 

Birmingham Area under the 2022 PM2.5 LMP 

Guidance, and EPA is not relying on it here. See 

the February 2, 2021, SIP revision for more details 

on this analysis. 

28ADEM does not monitor PM2.5 in the 

Birmingham MSA. 29The letter approving this network plan, except 

for the SO2 network, is available in the docket for 

this rulemaking. 

For example, the 2022 PM2.5 LMP 

Guidance discusses how an LMP might 

be especially appropriate for second 

maintenance plans, considering that the 

given area will have demonstrated 

attainment of the applicable PM2.5

NAAQS for at least eight years. With 

respect to second maintenance plans, 

the 2022 PM2.5 LMP Guidance indicates 

that the LMP submission should address 

the area’s PM2.5 air quality trends and 

historical and projected vehicle miles 

traveled (VMT) to meet the regulatory 

requirements at 40 CFR 93.109(e). The 

LMP would need to include 

documentation supporting the 

demonstration that it would be 

unreasonable to expect that such an area 

would experience enough motor vehicle 

emissions growth for a NAAQS 

violation to occur, per 40 CFR 93.109(e). 

The 2022 PM2.5 LMP Guidance goes on 

to note that if re-entrained road dust 

emissions have been found to be 

significant for PM2.5 transportation 

conformity purposes under 40 CFR 

93.102(b)(3), then the LMP should 

include an additional motor vehicle 

emissions analysis. 

As a result of neither the EPA 

Regional Administrator nor the ADEM 

director having made a finding that reentrained road dust emissions within 

the Birmingham Area were a significant 

contributor to the PM2.5 nonattainment 

problem, this LMP and ADEM’s first 10- 

year maintenance plan did not include 

emissions of re-entrained road dust as 

significant for transportation conformity 

analyses under 40 CFR 93.102(b)(3). 

Therefore, it was not necessary to 

perform additional on-road emissions 

analysis. The Birmingham Area MPO 

provided local VMT data, and ADEM 

included these VMT data, which show 

only a 12 percent projected VMT growth 

from the base year of 2017 to the final 

year of the plan in 2034, in the 

submittal. Additionally, EPA considered 

the regional emissions analysis results 

from the most recent transportation 

conformity determination adopted by 

the Birmingham MPO,26 shown in Table 

5, to include on-road emissions in the 

year 2024 of 0.57 and 16.48 tons per day 

of PM2.5 and NOX, respectively. 

TABLE 5—BIRMINGHAM MPO 2006 

ON-ROAD EMISSIONS IN TONS/DAY

(tpd) 

Analysis year 

On-road 

emissions 

PM2.5 NOX

2024 .................................. 0.57 16.48 

2034 .................................. 0.38 9.14 

2044 .................................. 0.37 8.41 

2050 .................................. 0.38 8.61 

The PM2.5 on-road emissions are 47 

percent below the 2024 budget of 1.21 

tpd. The PM2.5 on-road emissions 

continue to decline steadily from years 

2034 to 2050 to 31 percent of the 

budget. The NOX on-road emissions are 

34 percent below the 2024 budget of 

48.41 tpd and continue to decline 

steadily from years 2034 to 2050 to 18 

percent of the budget. Because the onroad emissions show an overall 

downward trend for PM2.5 and NOX, it 

would be unreasonable to expect that 

the Area would experience enough 

motor vehicle emissions growth for a 

PM2.5 NAAQS violation to occur as 

shown by the ADV and CDV 

calculations above. For the preceding 

reasons, the low projected growth in 

VMT over the 17-year period, and the 

downward trend in PM2.5 and NOX onroad vehicle emissions compared to the 

budget, the mobile source emissions are 

not expected to adversely impact the 

Area’s ability to continue to maintain 

compliance with the 2006 24-hour PM2.5

NAAQS. 

Therefore, the Birmingham Area is 

eligible for the LMP option, and the 

more detailed mobile source analysis 

that is found in the PM10 LMP Guidance 

is not required.27 EPA proposes to find 

that the long record of monitored PM2.5

concentrations that attain the NAAQS, 

ADEM’s air quality statistical analysis 

and EPA’s updated analysis, together 

with the continuation of existing 

emissions control programs, adequately 

provide for the maintenance of the 2006 

24-hour PM2.5 NAAQS in Birmingham 

through the second 10-year maintenance 

period and beyond. 

2. Stability of PM2.5 Levels 

As discussed above, the Birmingham 

Area has maintained air quality well 

below the 2006 24-hour PM2.5 NAAQS 

during the first maintenance period. 

Additionally, the DV data shown within 

Table 2 illustrate that 24-hour PM2.5

levels have been relatively stable over 

this timeframe, with a modest 

downward trend. For example, the data 

within Table 2 indicate that the highest 

year-over-year change in complete DVs 

at any given monitor between 2015– 

2019 was 2 mg/m3, which represented a 

10 percent change. See, e.g., the change 

at the Leeds monitor (AQS 01–073– 

1010) from 2014–2016 to 2015–2017. 

Furthermore, the overall trend in DVs 

for the Birmingham Area between 2015 

and 2019 shows a decrease of 13 percent 

at the highest-reading monitor with 

valid DVs, North Birmingham 01–073– 

0023, with overall decreases in DVs at 

each individual monitoring site in the 

Birmingham Area. Considering the 

2020, 2021, and 2022 DVs, which were 

finalized after ADEM’s February 2, 

2021, submittal, the trend between 

2015–2022 shows a decrease of 26.1 

percent at the North Birmingham 

monitor, 01–073–0023. This downward 

trend in PM2.5 levels, coupled with the 

relatively small, year-over-year variation 

in PM2.5 DVs, makes it reasonable to 

conclude that the Birmingham Area will 

not exceed the 2006 24-hour PM2.5

NAAQS during the second 10-year 

maintenance period. 

C. Monitoring Network and Verification 

of Continued Attainment 

EPA periodically reviews the PM2.5

monitoring network that the Jefferson 

County Department of Health (JCDH) 

operates and maintains in accordance 

with 40 CFR part 58. This network plan, 

which is submitted annually to EPA, is 

consistent with the most recent ambient 

air quality monitoring network 

assessment. The annual network plans 

developed by ADEM and JCDH follow a 

public notification and review process. 

EPA has reviewed and approved the 

2023 Ambient Air Monitoring Network 

Plan for JCDH.28 29

To verify the attainment status of the 

area over the maintenance period, the 

maintenance plan should contain 

provisions for continued operation of an 

appropriate, EPA-approved monitoring 

network in accordance with 40 CFR part 

58. As noted above, JCDH’s Network 

Plan for Birmingham, covering the PM2.5

network, has been approved by EPA in 

accordance with 40 CFR part 58, and the 

State has committed to continue 

operating all required PM2.5 monitors in 

the Area in accordance with part 58. 

EPA therefore proposes to find that the 

monitoring network is adequate to 


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30A certified air quality design value would be 

quality assured and quality controlled. 

31ADEM also states that in the event that any 

given year’s 98th percentile 24-hour concentrations 

is 36 mg/m3 or higher at any monitor in the Area 

the State will evaluate existing control measures to 

determine whether any further emission reductions 

should be implemented at that time. 

32See the Contingency Plan section of the LMP 

for further information regarding the contingency 

plan, including measures that ADEM will consider 

for adoption if a certified violation occurs. 

33On January 25, 2013, EPA approved the 2024 

motor vehicle emissions budgets associated with 

the first 10-year maintenance plan for the 

Birmingham Area for the 2006 24-hour PM2.5

NAAQS. See 78 FR 5306. 

verify continued attainment of the 2006 

24-hour PM2.5 NAAQS in the 

Birmingham Area. 

D. Contingency Plan 

Section 175A(d) of the CAA requires 

that a maintenance plan include 

contingency provisions. The purpose of 

such contingency provisions is to 

prevent future violations of the NAAQS 

or to promptly remedy any NAAQS 

violations that might occur during the 

maintenance period. The State should 

identify specific triggers which will be 

used to determine when the 

contingency measures need to be 

implemented. 

The LMP contains a commitment 

from Alabama to adopt, within 18 

months of certification of a violating 

DV 30 of the 2006 24-hour PM2.5 NAAQS 

in the Birmingham Area, one or more 

control measures as needed to reattain 

the NAAQS.31 If a certified violation 

occurs, Alabama will assess the 

violation and consider planned local 

and regional emission reductions and 

consider additional control measures as 

needed to attain the NAAQS. 

EPA proposes to find that the 

contingency provisions in Alabama’s 

second maintenance plan for the 2006 

24-hour PM2.5 NAAQS meet the 

requirements of CAA section 175A(d).32

E. Conclusion 

EPA proposes to approve the 

Birmingham LMP for the 2006 24-hour 

PM2.5 NAAQS, which includes updates 

of the various elements (including 

attainment inventory, assurance of 

adequate monitoring and verification of 

continued attainment, and contingency 

provisions) of the initial EPA-approved 

maintenance plan for the 2006 24-hour 

PM2.5 NAAQS. EPA also finds that the 

Birmingham Area qualifies for the LMP 

option and adequately provides for 

maintenance of the 2006 24-hour PM2.5

NAAQS through 2034, i.e., beyond the 

20 years following redesignation of the 

Area to attainment, and thereby satisfies 

the requirements for such a plan under 

CAA section 175A(b). EPA is therefore 

proposing to approve Alabama’s 

February 2, 2021, submission of the 

Birmingham Area 2006 24-hour PM2.5

NAAQS LMP as a revision to the 

Alabama SIP. 

V. Transportation Conformity 

Transportation conformity is required 

by section 176(c) of the CAA. 

Conformity to a SIP means that 

transportation activities will not 

produce new air quality violations, 

worsen existing violations, or delay 

timely attainment of the NAAQS. See 

CAA 176(c)(1)(A) and (B). EPA’s 

transportation conformity rule at 40 CFR 

part 93, subpart A, requires that 

transportation plans, programs, and 

projects conform to SIPs and establishes 

the criteria and procedures for 

determining whether they conform. The 

conformity rule generally requires a 

demonstration that emissions from the 

Regional Transportation Plan (RTP) and 

the Transportation Improvement 

Program (TIP) are consistent with the 

motor vehicle emissions budget (budget) 

contained in the control strategy SIP 

revision or maintenance plan. See 40 

CFR 93.101, 93.118, and 93.124. A 

motor vehicle emissions budget is 

defined as ‘‘that portion of the total 

allowable emissions defined in the 

submitted or approved control strategy 

implementation plan revision or 

maintenance plan for a certain date for 

the purpose of meeting reasonable 

further progress milestones or 

demonstrating attainment or 

maintenance of the NAAQS, for any 

criteria pollutant or its precursors, 

allocated to highway and transit vehicle 

use and emissions.’’ See 40 CFR 93.101. 

Under the transportation conformity 

rule, LMP areas may demonstrate 

conformity without a regional emissions 

analysis. See 40 CFR 93.109(e). For 

LMPs, which do not include budgets, 

EPA also reviews whether the LMP 

makes the demonstration that it would 

be unreasonable to expect so much 

motor vehicle emissions growth that the 

area would violate the NAAQS. See 40 

CFR 93.109(e). As discussed in the 

Section IV above, the low VMT growth 

from 2017 to 2034, the downward trend 

in PM2.5 and NOX on-road vehicle 

emissions documented in the 

Birmingham MPO’s recent conformity 

determination, and the emission results 

from the MPO’s conformity 

determination compared to the 2024 

budgets collectively demonstrate that it 

is unreasonable to expect so much 

motor vehicle emissions growth that the 

area would violate the NAAQS.33

EPA’s substantive criteria for 

determining the adequacy of certain SIP 

submissions, including maintenance 

plans, are set out in 40 CFR 93.118(e)(4). 

The process for determining adequacy is 

outlined in 40 CFR 93.118(f). EPA 

intends to make its determination 

regarding the adequacy of the 

Birmingham Area LMP for 

transportation conformity purposes in 

the near future by completing the 

adequacy process together with any 

final decision on this proposed 

rulemaking. 

Today’s proposal notifies the public 

that EPA has received this LMP, which 

EPA will review for adequacy, and 

begins the public comment period. EPA 

invites the public to comment on the 

adequacy of the LMP as well as other 

aspects of the action EPA is proposing 

in this notice. Comments submitted as 

part of the adequacy process must be 

submitted by the close of the comment 

period on this NPRM. 

If EPA approves this LMP or makes an 

adequacy finding for this LMP, after 

2024, the motor vehicle emissions in the 

Birmingham Area may be treated as 

essentially not constraining for the 

second 10-year maintenance period 

because EPA would have concluded 

that it is unreasonable to expect that the 

area will experience so much motor 

vehicle emissions growth during this 

period of time that a violation of the 

PM2.5 NAAQS would result. When 

determining conformity of 

transportation plans and TIPs after the 

year 2024, MPOs would not have to do 

a regional emissions analysis. 

Birmingham has approved budgets from 

the first 10-year maintenance plan for 

the year 2024, and if a transportation 

conformity determination is needed and 

2024 is in the timeframe of the 

determination, the MPO would have to 

perform a regional emissions analysis 

and compare the results to the 2024 

budgets. All actions for transportation 

plans and transportation improvement 

programs that would require a 

transportation conformity determination 

for the Birmingham 2006 24-hour PM2.5

maintenance area under EPA’s 

transportation conformity rule 

provisions are considered to have 

already satisfied the regional emissions 

analysis and ‘‘budget test’’ requirements 

in 40 CFR 93.118. See 40 CFR 93.109(e) 

and 69 FR 40004 (July 1, 2004). 

However, because LMP areas are still 

maintenance areas, certain aspects of 

transportation conformity 

determinations still will be required for 

transportation plans, programs, and 

projects. As stated in 40 CFR 93.109(e), 

‘‘A conformity determination that meets 

other applicable criteria in Table 1 of 


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paragraph (b) of this section is still 

required.’’ Specifically, consultation (40 

CFR 93.112) is required for all 

transportation conformity 

determinations. Conformity 

determinations for RTPs and TIPs still 

will have to demonstrate that they are 

fiscally constrained (40 CFR 93.108) and 

provide for timely implementation of 

Transportation Control Measures from 

the applicable implementation plan (40 

CFR 93.113). Any conformity 

determinations made for transportation 

projects must demonstrate that there is 

a currently conforming transportation 

plan and TIP (40 CFR 93.114) and that 

the project is from that conforming plan 

and TIP (40 CFR 93.115), meet the hotspot requirements for projects (40 CFR 

93.116), and ensure that the project 

complies with any PM control measures 

in the SIP (40 CFR 93.117). 

Additionally, conformity of 

transportation plans and TIPs, plan and 

TIP amendments, and transportation 

projects must be demonstrated in 

accordance with the timing 

requirements specified in 40 CFR 

93.104; for RTPs and TIPs, this is no less 

frequently than every four years. 

VI. General Conformity 

The conformity requirement under 

CAA section 176(c) ensures that Federal 

activities implemented by Federal 

agencies will not interfere with a State’s 

ability to attain and maintain the 

NAAQS. Under CAA 176(c)(1), the 

requirement prohibits Federal agencies 

from approving, permitting, licensing, 

or funding activities that do not conform 

to the purpose of the applicable SIP for 

the control and prevention of air 

pollution. See CAA section 176(c)(1)(A). 

Under CAA section 176(c)(1)(B), 

conformity to an implementation plan 

means that Federal activities will not 

cause or contribute to any new 

violations of the NAAQS, increase the 

frequency or severity of any existing 

NAAQS violation, or delay timely 

attainment or any required interim 

emissions reductions or other 

milestones contained in the applicable 

SIP. 

The general conformity program 

implements CAA section 176(c)(4)(A), 

and the criteria and procedures for 

determining conformity of general 

Federal activities to the applicable SIP 

are established under 40 CFR part 93, 

subpart B, sections 93.150 through 

93.165. General conformity 

requirements apply to Federal activities 

that (1) would cause emissions of 

relevant criteria or precursor pollutants 

to originate within nonattainment areas 

or areas that have been redesignated to 

attainment with an approved CAA 

section 175A maintenance plan (i.e., 

maintenance areas), as given under 40 

CFR 93.153(b), and (2) are not Federal 

Highway Administration (FHWA) or 

Federal Transit Administration (FTA) 

transportation projects as defined in 40 

CFR 93.101 under the transportation 

conformity requirements. See 40 CFR 

93.153(a). 

The general conformity regulations do 

not provide special flexibility to account 

for when EPA establishes a LMP for a 

maintenance area. EPA notes that the 

PM10 LMP Guidance (2001) stated that 

Federal actions subject to the general 

conformity regulations could be 

considered to satisfy the ‘‘budget test’’ 

because the budgets are essentially 

considered to be unlimited (i.e., 

unconstrained). However, unlike the 

transportation conformity regulations, 

the concept of unconstrained emissions 

budgets has no meaning under the 

general conformity regulations. There is 

no provision in the general conformity 

regulations for a LMP claiming 

unconstrained emissions budgets and 

no exception to applying the limitations 

of the de minimis threshold rates to an 

action’s emissions that could trigger the 

requirement for a general conformity 

determination. The concept of an 

unconstrained budget cannot be relied 

upon by a Federal agency to make a 

general conformity determination. Thus, 

for general Federal actions proposed for 

maintenance areas with LMPs, such as 

this proposed rulemaking, the criteria 

and procedures outlined in subpart B 

shall apply in the same way as for any 

non-LMP maintenance area. 

VII. Proposed Action 

Under sections 110(k) and 175A of the 

CAA and for the reasons set forth above, 

EPA is proposing to approve the 

Birmingham Area LMP for the 2006 24- 

hour PM2.5 NAAQS, submitted by 

ADEM on February 2, 2021, as a 

revision to the Alabama SIP. EPA is 

proposing to approve the Birmingham 

Area LMP because it includes an 

acceptable update of the various 

elements of the 2006 24-hour PM2.5

NAAQS maintenance plan approved by 

EPA for the first 10-year period 

(including emissions inventory, 

assurance of adequate monitoring and 

verification of continued attainment, 

and contingency provisions), and 

retains the relevant provisions of the 

SIP. 

EPA also finds that the Birmingham 

Area qualifies for the LMP option. We 

propose to approve the LMP because the 

Birmingham Area LMP adequately 

provides for maintenance of the 2006 

24-hour PM2.5 NAAQS over the second 

10-year maintenance period, through 

2034, and thereby satisfies the 

requirements for such a plan under CAA 

section 175A(b). 

VIII. Statutory and Executive Order 

Reviews 

Under the CAA, the Administrator is 

required to approve a SIP submission 

that complies with the provisions of the 

CAA 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 CAA. Accordingly, this action 

proposes to approve State law as 

meeting Federal requirements and does 

not impose additional requirements 

beyond those imposed by State law. For 

that reason, this proposed action: 

• Is not a significant regulatory action 

subject to review by the Office of 

Management and Budget under 

Executive Orders 12866 (58 FR 51735, 

October 4, 1993) and 14094 (88 FR 

21879, April 11, 2023); 

• Does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act (44 

U.S.C. 3501 et seq.); 

• Is certified as not having a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act (5 

U.S.C. 601 et seq.); 

• Does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4); 

• Does not have federalism 

implications as specified in Executive 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not subject to Executive Order 

13045 (62 FR 19885, April 23, 1997) 

because it approves a State program; 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); and 

• Is not subject to requirements of 

section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (15 U.S.C. 272 note) because 

application of those requirements would 

be inconsistent with the CAA. 

In addition, the SIP is not approved 

to apply on any Indian reservation land 

or in any other area where EPA or an 

Indian tribe has demonstrated that a 

tribe has jurisdiction. In those areas of 

Indian country, the proposed rule does 

not have Tribal implications and will 

not impose substantial direct costs on 

Tribal governments or preempt Tribal 

law as specified by Executive Order 

13175 (65 FR 67249, November 9, 2000). 

Executive Order 12898 (Federal 

Actions To Address Environmental 


khammond on DSKJM1Z7X2PROD with PROPOSALS
86312 Federal Register / Vol. 88, No. 238 / Wednesday, December 13, 2023 / Proposed Rules 

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 minority populations 

and low-income populations to the 

greatest extent practicable and 

permitted by law. EPA defines 

environmental justice (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.’’ 

ADEM did not evaluate EJ 

considerations as part of its SIP 

submittal; the CAA and applicable 

implementing regulations neither 

prohibit nor require such an evaluation. 

EPA did not perform an EJ analysis and 

did not consider EJ in this proposed 

action. Due to the nature of the action 

being proposed here, this proposed 

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 proposed action, 

and there is no information in the 

record inconsistent with the stated goal 

of E.O. 12898 of achieving EJ for people 

of color, low-income populations, and 

Indigenous peoples. 

List of Subjects in 40 CFR Part 52 

Environmental Protection, Air 

Pollution Control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen dioxide, Particulate Matter, 

Reporting and recordkeeping 

requirements, Sulfur oxides, Volatile 

organic compounds. 

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

Dated: December 7, 2023. 

Jeaneanne Gettle, 

Acting Regional Administrator, Region 4. 

[FR Doc. 2023–27297 Filed 12–12–23; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 62 

[EPA–R10–OAR–2023–0224; FRL–10859– 

01–R10] 

Approval and Promulgation of State 

Plans for Designated Facilities and 

Pollutants; Spokane Regional Clean 

Air Agency; Control of Emissions 

From Existing Large Municipal Waste 

Combustors 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to partially 

approve and partially disapprove a 

Clean Air Act (CAA) State Plan 

submitted by the Spokane Regional 

Clean Air Agency (SRCAA). This State 

Plan establishes emission limits for 

existing large municipal waste 

combustors (MWC) and provides for the 

implementation and enforcement of 

these limits. SRCAA submitted this 

State Plan to fulfill its requirements 

under the CAA in response to the EPA’s 

promulgation of Emissions Guidelines 

and Compliance Times for Large MWC 

Constructed on or before September 20, 

1994 (Emission Guidelines). The EPA is 

partially approving the State Plan 

because it meets the requirements of the 

Emission Guidelines for existing large 

MWC known to operate in Spokane 

County, Washington. The EPA is 

partially disapproving the State Plan 

because it omits requirements for 

fluidized bed combustors and air 

curtain incinerators, which are required 

elements of a State Plan. 

DATES: Written comments must be 

received on or before January 12, 2024. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R10– 

OAR–2023–0224 at 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, 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. 

FOR FURTHER INFORMATION CONTACT: 

Bryan Holtrop (he/him), U.S. EPA, 

Region 10. He can be reached by phone 

at (206) 553–4473 or by email at 

holtrop.bryan@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. Background 

Section 111(d) of the CAA requires 

the EPA to establish a procedure for a 

state to submit a plan to the EPA that 

establishes standards of performance for 

any air pollutant: (1) for which air 

quality criteria have not been issued or 

which is not included on a list 

published under CAA section 108 or 

emitted from a source category which is 

regulated under CAA section 112 and 

(2) to which a standard of performance 

under CAA section 111 would apply if 

such existing source were a new source. 

Section 129(b)(2) of the CAA requires 

that after the EPA promulgates 

guidelines for a category of solid waste 

incineration units, each state in which 

units in the category are operating shall 

submit to the EPA a plan to implement 

and enforce the guidelines with respect 

to such units. Such plans shall be at 

least as protective as the guidelines 

promulgated by the EPA. The EPA 

established requirements for State Plan 

submittals in the Code of Federal 

Regulations (CFR) at 40 CFR part 60, 

subpart B. State submittals under CAA 

sections 111(d) and 129 must be 

consistent with the relevant emission 

guidelines, in this instance 40 CFR part 

60, subpart Cb, and the requirements of 

40 CFR part 60, subpart B. 

On May 10, 2006, the EPA revised the 

regulations established for Emissions 

Guidelines and Compliance Times for 

Large MWC That Are Constructed on or 

before September 20, 1994, in 40 CFR 

part 60, subpart Cb (71 FR 27324). This 

action was taken under sections 111(d) 

and 129 of the CAA. 

On July 18, 2022, SRCAA submitted 

to the EPA a section 111(d)/129 plan for 

existing large MWC. The submitted 

section plan was in response to the May 

10, 2006, promulgation of Federal 

emission guidelines requirements for 

large MWC, 40 CFR part 60, subpart Cb 

(71 FR 27336). 


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