52864 Federal Register / Vol. 86, No. 182 / Thursday, September 23, 2021 / Proposed Rules 

PART 71—DESIGNATION OF CLASS A, 

B, C, D, AND E AIRSPACE AREAS; AIR 

TRAFFIC SERVICE ROUTES; AND 

REPORTING POINTS 

■ 1. The authority citation for part 71 

continues to read as follows: 

Authority: 49 U.S.C. 106(f), 106(g); 40103, 

40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 

1959–1963 Comp., p. 389. 

§ 71.1 [Amended] 

■ 2. The incorporation by reference in 

14 CFR 71.1 of FAA Order JO 7400.11F, 

Airspace Designations and Reporting 

Points, dated August 10, 2021, and 

effective September 15, 2021, is 

amended as follows: 

Paragraph 6011 United States Area 

Navigation Routes. 

* * * * * 

T–222 ST. PAUL ISLAND, AK TO FAIRBANKS, AK [AMENDED] 

ST. PAUL ISLAND, AK (SPY) NDB (Lat. 57°09′25.20′′ N, long. 170°13′58.77′′ W) 

BETHEL, AK (BET) VORTAC (Lat. 60°47′05.41′′ N, long. 161°49′27.59′′ W) 

CABOT, AK WP (Lat. 61°12′01.32′′ N, long. 160°45′20.93′′ W) 

WOGAX, AK WP (Lat. 61°29′41.04′′ N, long. 160°06′19.41′′ W) 

IKUFU, AK WP (Lat. 61°40′34.53′′ N, long. 159°52′35.43′′ W) 

JILSI, AK WP (Lat. 61°46′52.14′′ N, long. 159°31′07.72′′ W) 

CYCAS, AK WP (Lat. 61°52′23.15′′ N, long. 159°13′52.38′′ W) 

UTICE, AK WP (Lat. 62°18′35.36′′ N, long. 157°37′56.78′′ W) 

MC GRATH, AK (MCG) VORTAC (Lat. 62°57′03.72′′ N, long. 155°36′40.97′′ W) 

NENANA, AK (ENN) VORTAC (Lat. 64°35′24.04′′ N, long. 149°04′22.34′′ W) 

FAIRBANKS, AK (FAI) VORTAC (Lat. 64°48′00.25′′ N, long. 148°00′43.11′′ W) 

* * * * * 

Issued in Washington, DC, on September 

17, 2021. 

Michael R. Beckles, 

Acting Manager, Rules and Regulations 

Group. 

[FR Doc. 2021–20577 Filed 9–22–21; 8:45 am] 

BILLING CODE 4910–13–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R04–OAR–2020–0428; FRL–8911–01– 

R4] 

Air Plan Approval; TN; Montgomery 

County Limited Maintenance Plan for 

the 1997 8-Hour Ozone 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 Tennessee, 

through the Tennessee Department of 

Environment and Conservation (TDEC), 

Air Pollution Control Division, on June 

23, 2020. The SIP revision includes the 

1997 8-hour ozone national ambient air 

quality standards (NAAQS) Limited 

Maintenance Plan (LMP) for the 

Montgomery County, Tennessee portion 

of the Clarksville-Hopkinsville Area 

(hereinafter referred to as the 

‘‘Montgomery County Area’’ or ‘‘Area’’). 

The Clarksville-Hopkinsville Area is 

comprised of Montgomery County, 

Tennessee, and Christian County, 

Kentucky. EPA is proposing to approve 

Tennessee’s LMP for the Montgomery 

County Area because it provides for the 

maintenance of the 1997 8-hour ozone 

NAAQS within the Montgomery County 

Area through the end of the second 10- 

year portion of the maintenance period. 

The effect of this action would be to 

make certain commitments related to 

maintenance of the 1997 8-hour ozone 

NAAQS in the Montgomery County 

Area federally enforceable as part of the 

Tennessee SIP. 

DATES: Comments must be received on 

or before October 25, 2021. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R04– 

OAR–2020–0428 at http://

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 

http://www2.epa.gov/dockets/ 

commenting-epa-dockets. 

FOR FURTHER INFORMATION CONTACT: 

Sarah LaRocca, 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– 

8994. Ms. LaRocca can also be reached 

via electronic mail at larocca.sarah@

epa.gov. 

SUPPLEMENTARY INFORMATION: 

Table of Contents 

I. Summary of EPA’s Proposed Action 

II. Background 

III. Tennessee’s SIP Submittal 

IV. EPA’s Evaluation of Tennessee’s SIP 

Submittal 

A. Attainment Emissions Inventory 

B. Maintenance Demonstration 

C. Monitoring Network and Verification of 

Continued Attainment 

D. Contingency Plan 

E. Conclusion 

V. Transportation Conformity 

VI. Proposed Action 

VII. Statutory and Executive Order Reviews 

I. Summary of EPA’s Proposed Action 

In accordance with the Clean Air Act 

(CAA or Act), EPA is proposing to 

approve the Montgomery County Area 

LMP for the 1997 8-hour ozone NAAQS, 

adopted by TDEC on June 10, 2020, and 

submitted by TDEC as a revision to the 

Tennessee SIP on June 23, 2020. In 

2004, the Montgomery County Area was 

designated as nonattainment for the 

1997 8-hour ozone NAAQS. 

Subsequently, in 2005, after having 

clean data and EPA’s approval of a 

maintenance plan, the Area was 

redesignated to attainment for the 1997 

8-hour ozone NAAQS. See 70 FR 55559 

(September 22, 2005). 

The Montgomery County Area LMP, 

submitted by TDEC on June 23, 2020, is 

designed to maintain the 1997 8-hour 

ozone NAAQS within the Montgomery 

County 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 Montgomery 

County Area LMP relies on the same 


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1See ‘‘Fact Sheet, Proposal to Revise the National 

Ambient Air Quality Standards for Ozone,’’ January 

6, 2010 and 27 FR 2938 (January 19, 2010). 

2 In March 2008, EPA completed another review 

of the primary and secondary ozone NAAQS and 

tightened them further by lowering the level for 

both to 0.075 ppm. See 73 FR 16436 (March 27, 

2008). Additionally, in October 2015, EPA 

completed a review of the primary and secondary 

ozone NAAQS and tightened them by lowering the 

level for both to 0.070 ppm. See 80 FR 65292 

(October 26, 2015). 

3Section 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. 

4 John Calcagni, Director, Air Quality 

Management Division, EPA Office of Air Quality 

Planning and Standards (OAQPS), ‘‘Procedures for 

Processing Requests to Redesignate Areas to 

Attainment,’’ September 4, 1992 (Calcagni memo). 5The ozone design value for a monitoring site is 

the 3-year average of the annual fourth-highest daily 

maximum 8-hour average ozone concentrations. 

The design value for an ozone area is the highest 

design value of any monitoring site in the area. 6See ‘‘Limited Maintenance Plan Option for 

Nonclassifiable Ozone Nonattainment Areas,’’ from 

Sally L. Shaver, OAQPS, November 16, 1994; 

‘‘Limited Maintenance Plan Option for 

Nonclassifiable CO Nonattainment Areas,’’ from 

Joseph Paisie, OAQPS, October 6, 1995; and 

‘‘Limited Maintenance Plan Option for Moderate 

PM10 Nonattainment Areas,’’ from Lydia Wegman, 

OAQPS, August 9, 2001. Copies of these guidance 

memoranda can be found in the docket for this 

proposed rulemaking. 

control measures and contingency 

provisions to maintain the 1997 8-hour 

ozone NAAQS during the second 10- 

year portion of the maintenance period 

as the maintenance plan submitted by 

TDEC for the first 10-year period. 

II. Background 

Ground-level ozone is formed when 

oxides of nitrogen (NOX) and volatile 

organic compounds (VOC) react in the 

presence of sunlight. These two 

pollutants, referred to as ozone 

precursors, are emitted by many types of 

pollution sources, including on- and offroad motor vehicles and engines, power 

plants and industrial facilities, and 

smaller area sources such as lawn and 

garden equipment and paints. Scientific 

evidence indicates that adverse public 

health effects occur following exposure 

to ozone, particularly in children and in 

adults with lung disease. Breathing air 

containing ozone can reduce lung 

function and inflame airways, which 

can increase respiratory symptoms and 

aggravate asthma and other lung 

diseases. 

Ozone exposure also has been 

associated with increased susceptibility 

to respiratory infections, medication 

use, doctor visits, and emergency 

department visits and hospital 

admissions for individuals with lung 

disease. Children are at increased risk 

from exposure to ozone because their 

lungs are still developing and they are 

more likely to be active outdoors, which 

increases their exposure.1

In 1979, under section 109 of the 

CAA, EPA established primary and 

secondary NAAQS for ozone at 0.12 

parts per million (ppm), averaged over 

a 1-hour period. See 44 FR 8202 

(February 8, 1979). On July 18, 1997, 

EPA revised the primary and secondary 

NAAQS for ozone to set the acceptable 

level of ozone in the ambient air at 0.08 

ppm, averaged over an 8-hour period. 

See 62 FR 38856 (July 18, 1997).2 EPA 

set the 8-hour ozone NAAQS based on 

scientific evidence demonstrating that 

ozone causes adverse health effects at 

lower concentrations and over longer 

periods of time than was understood 

when the pre-existing 1-hour ozone 

NAAQS was set. EPA determined that 

the 8-hour NAAQS would be more 

protective of human health, especially 

children and adults who are active 

outdoors, and individuals with a preexisting respiratory disease, such as 

asthma. 

Following promulgation of a new or 

revised NAAQS, EPA is required by the 

CAA to designate areas throughout the 

nation as attaining or not attaining the 

NAAQS. On April 15, 2004, EPA 

designated the Clarksville-Hopkinsville 

Area, which included Montgomery 

County, Tennessee, and Christian 

County, Kentucky, as nonattainment for 

the 1997 8-hour ozone NAAQS, and the 

designation became effective on June 15, 

2004. See 69 FR 23858 (April 30, 2004). 

Similarly, on May 21, 2012, EPA 

designated areas as unclassifiable/ 

attainment or nonattainment for the 

2008 8-hour ozone NAAQS. EPA 

designated Montgomery County as 

unclassifiable/attainment for the 2008 8- 

hour ozone NAAQS. This designation 

became effective on July 20, 2012. See 

77 FR 30088 (May 21, 2012). In 

addition, on November 16, 2017, areas 

were designated for the 2015 8-hour 

ozone NAAQS. The Montgomery 

County Area was designated attainment/ 

unclassifiable for the 2015 8-hour ozone 

NAAQS, with an effective date of 

January 16, 2018. See 82 FR 54232 

(November 16, 2017). 

A state may submit a request to 

redesignate a nonattainment area that is 

attaining a NAAQS to attainment, and, 

if the area has met other required 

criteria described in section 107(d)(3)(E) 

of the CAA, EPA may approve the 

redesignation request.3 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 ten 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). 

EPA has published long-standing 

guidance for states on developing 

maintenance plans.4 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 page 

9. EPA clarified in three 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 5 being significantly below 

the standard and the area having a 

historically stable design value.6 EPA 

refers to a maintenance plan containing 

this streamlined demonstration as an 

LMP. 

EPA has interpreted CAA section 

175A as permitting the LMP option 

because section 175A of the Act does 

not define how areas may demonstrate 

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 the LMP 

guidance memoranda, 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 


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7The prior 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 for the carbon 

monoxide (CO) NAAQS. 

8See, e.g., 79 FR 41900 (July 18, 2014) (approval 

of the second ten-year LMP for the Grant County 

1971 SO2 maintenance area). 

9See 86 FR 12092 (March 2, 2021). 

10See Calcagni memo. 

LMP must still submit its section 175A 

maintenance plan 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,7

EPA has extended the LMP 

interpretation of section 175A to other 

NAAQS and pollutants not specifically 

covered by the previous guidance 

memos.8

In this case, EPA is proposing to 

approve Tennessee’s LMP because the 

State has made a showing, consistent 

with EPA’s prior LMP guidance, that the 

Clarksville-Hopkinsville Area’s ozone 

concentrations are well below the 1997 

8-hour ozone NAAQS and have been 

historically stable and that it has met 

the other maintenance plan 

requirements. TDEC submitted this LMP 

for the Montgomery County Area to 

fulfill the second maintenance plan 

requirement in the Act. EPA’s 

evaluation of the Montgomery County 

Area’s LMP is presented below. 

In August of 2005, TDEC submitted to 

EPA a request to redesignate the 

Montgomery County Area to attainment 

for the 1997 8-hour ozone NAAQS. This 

submittal included a plan to provide for 

maintenance of the 1997 8-hour ozone 

NAAQS in Montgomery County through 

2016 as a revision to the Tennessee SIP. 

EPA approved the Montgomery County 

Area’s Maintenance Plan and the State’s 

request to redesignate the Montgomery 

County Area to attainment for the 1997 

8-hour ozone NAAQS, effective 

November 21, 2005. See 70 FR 55559 

(September 22, 2005). 

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. EPA’s final 

implementation rule for the 2008 8-hour 

ozone NAAQS revoked the 1997 8-hour 

ozone NAAQS and stated that one 

consequence of revocation was that 

areas that had been redesignated to 

attainment (i.e., maintenance areas) for 

the 1997 NAAQS no longer needed to 

submit second 10-year maintenance 

plans under CAA section 175A(b). See 

80 FR 12264, 12315 (March 6, 2015). 

In South Coast Air Quality 

Management District v. EPA, the United 

States Court of Appeals for the District 

of Columbia Circuit (D.C. Circuit) 

vacated the EPA’s interpretation that, 

because of the revocation of the 1997 8- 

hour ozone NAAQS, second 

maintenance plans were not required for 

‘‘orphan maintenance areas,’’ i.e., areas 

that had been redesignated to 

attainment for the 1997 8-hour ozone 

NAAQS maintenance areas and were 

designated attainment for the 2008 

ozone NAAQS. South Coast, 882 F.3d 

1138 (D.C. Cir. 2018). Thus, states with 

these ‘‘orphan maintenance areas’’ 

under the 1997 8-hour ozone NAAQS 

must submit maintenance plans for the 

second maintenance period. 

Accordingly, on June 23, 2020, 

Tennessee submitted a second 

maintenance plan for the Montgomery 

County Area that shows that the Area is 

expected to remain in attainment of the 

1997 8-hour ozone NAAQS through 

2025. 

In recognition of the continuing 

record of air quality monitoring data 

showing ambient 8-hour ozone 

concentrations in the ClarksvilleHopkinsville Area well below the 1997 

8-hour ozone NAAQS, TDEC chose the 

LMP option for the development of a 

second 1997 8-hour ozone NAAQS 

maintenance plan. On June 10, 2020, 

TDEC adopted the second 10-year 1997 

8-hour ozone maintenance plan, and on 

June 23, 2020, TDEC submitted the 

Montgomery County Area LMP to EPA 

as a revision to the Tennessee SIP. 

III. Tennessee’s SIP Submittal 

As mentioned above, on June 23, 

2020, TDEC submitted the Montgomery 

County Area 1997 8-Hour Ozone 

NAAQS LMP to EPA as a revision to the 

Tennessee SIP. The submittal includes 

the LMP, air quality data, emissions 

inventory information, and appendices, 

as well as certification of adoption of 

the plan by TDEC. Appendices to the 

plan include comments and responses 

between EPA and TDEC; documentation 

of notice, hearing, and public 

participation prior to adoption of the 

plan by the TDEC on June 10, 2020; 

interagency consultation; and Air 

Pollution Control Board order, which 

notes that Tennessee’s LMP submittal 

for the remainder of the 20-year 

maintenance period for the for the 

Montgomery County Area is in response 

to the D.C. Circuit’s decision 

overturning aspects of EPA’s 

implementation rule for the 2008 8-hour 

ozone NAAQS. The Montgomery 

County Area LMP does not include any 

additional emissions reduction 

measures but relies on the same 

emission reduction strategy as the first 

10-year Maintenance Plan that provides 

for maintenance of the 1997 ozone 

NAAQS through 2016. The measures 

upon which the second 10-year LMP for 

the Montgomery County Area relies 

include the SIP-approved version of 

Tennessee Air Pollution Control 

Regulation 1200–03–27–.12, NOX SIP 

Call Requirements for Stationary Boilers 

and Combustion Turbines, which 

established a state control program for 

sources that are subject to the NOX SIP 

Call but not covered under Cross State 

Air Pollution Rule (CSAPR).9 The LMP 

also relies on continued implementation 

of federal measures (e.g., interstate 

transport rules such as CSAPR, see 76 

FR 48208 (August 8, 2011), and the 

CSAPR Update, see 81 FR 74504 

(October 26, 2016)). 

IV. EPA’s Evaluation of Tennessee’s SIP 

Submittal 

EPA has reviewed the Montgomery 

County Area’s LMP which is designed 

to maintain the 1997 8-hour ozone 

NAAQS within Montgomery County 

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 10 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 

ozone, the inventory should be based on 

typical summer day emissions of VOCs 

and NOX, as these pollutants are 

precursors to ozone formation. The 

Montgomery County Area LMP includes 

an ozone attainment inventory for 

Montgomery County that reflects typical 

summer day emissions in 2014. Table 1 

presents a summary of the inventory for 

2014 contained in the LMP. 


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11See email from James Johnston, TDEC, to 

Lynorae Benjamin, EPA Region 4, on December 15, 

2020, available in the docket for this proposed 

rulemaking. 

12EPA developed emissions for these sectors 

based on AP–42 emissions factor, and information 

supplied by the Eastern Regional Technical 

Advisory Committee for locomotives and Federal 

Aviation Administration’s Emissions and 

Dispersion Modeling System (since replaced by the 

Aviation Environmental Design Tool). 

13See footnote 4. 

14See the spreadsheet titled ‘‘Ozone Design 

Values, 2018 (XLXS)’’ at https://www.epa.gov/airtrends/air-quality-design-values#report. 

15See the spreadsheet titled ‘‘Ozone Design 

Values, 2020 (XLXS)’’ at https://www.epa.gov/airtrends/air-quality-design-values#report. 

TABLE 1—2014 TYPICAL SUMMER DAY 8-HOUR OZONE EMISSIONS FOR THE MONTGOMERY COUNTY AREA

[Tons/summer day] 

Source category VOC 

emissions 

NOX

emissions 

Fire ........................................................................................................................................................................... * 0.00 * 0.00 

Nonpoint ................................................................................................................................................................... 8.79 0.90 

Nonroad ................................................................................................................................................................... 1.58 1.35 

Onroad ..................................................................................................................................................................... 4.76 7.64 

Point ......................................................................................................................................................................... 0.97 0.50 

Total .................................................................................................................................................................. * 16.10 10.39 

* This Total VOC Emissions value differs from Tennessee’s submittal and has been re-calculated by TDEC to accurately reflect the total VOC 

emissions for Montgomery County.11

The Emissions Inventory section of 

the Montgomery County Area’s LMP 

describes the methods, models, and 

assumptions used to develop the 

attainment inventory. As described in 

the Emissions Inventory section of the 

LMP, TDEC generally relied upon 

emissions inventory information from 

the EPA 2014 version 7.0 air quality 

modeling platform (2014v7.0 platform), 

which is based on the 2014 NEI. The 

emissions data in the 2014v7.0 platform 

are primarily based on the 2014NEIv1 

for point sources, nonpoint sources, 

commercial marine vessels (CMV), 

onroad and nonroad mobile sources, 

and fires. This 2014 modeling platform 

includes all criteria air pollutants 

(CAPs) and precursors and two groups 

of hazardous air pollutants (HAPs). 

Nonroad mobile source emissions in 

the 2014NEIv1, in part, were estimated 

using the latest version of the EPA’s 

motor vehicle emissions model, MOVES 

2014a (which includes estimates of 

nonroad emissions like agriculture, 

commercial and mining, industrial and 

recreational equipment, and commercial 

and residential lawn and garden 

equipment). Locomotives, aircraft, and 

marine nonroad sources are not 

included in MOVES, and TDEC relied 

on EPA-generated emissions for these 

sectors.12 Onroad mobile sources in the 

2014NEIv1 were estimated using 

MOVES 2014a and the latest planning 

assumptions regarding vehicle type, 

activity, and vehicle speeds to estimate 

vehicular emissions for 2014. 

MOVES2014a was used with inputs, 

where provided, by state and local 

agencies, in combination with EPAgenerated default data. In its entirety, 

the 2014v7.0 platform’s set of estimates 

for vehicles reflects 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. 

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 over the 

second 10-year maintenance period is 

low.13 These criteria are evaluated 

below with regard to the ClarksvilleHopkinsville Area as a whole. 

1. Evaluation of Ozone Air Quality 

Levels 

To attain the 1997 8-hour ozone 

NAAQS, the three-year average of the 

fourth-highest daily maximum 8-hour 

average ozone concentrations (design 

value) at each monitor within an area 

must not exceed 0.08 ppm. Based on the 

rounding convention described in 40 

CFR part 50, Appendix I, the NAAQS is 

attained if the design value is 0.084 ppm 

or below. There is currently one monitor 

measuring ozone, located within 

Christian County, Kentucky, which 

provides air quality data for the entire 

Clarksville-Hopkinsville Area. At the 

time of submission, EPA evaluated 

quality assured and certified 2016–2018 

monitoring data 14 and determined that 

the design value for the ClarksvilleHopkinsville Area was 0.060 ppm, or 71 

percent of the level of the 1997 8-hour 

ozone NAAQS. Based on quality 

assured and certified monitoring data 

for 2018–2020,15 the current design 

value for the Clarksville-Hopkinsville 

Area is 0.058 ppm, or 69 percent of the 

level of the 1997 8-hour ozone NAAQS. 

Consistent with prior guidance, EPA 

believes that if the most recent air 

quality design value for the area is at a 

level that is well below the NAAQS 

(e.g., below 85 percent of the NAAQS, 

or in this case, below 0.071 ppm), then 

EPA considers the state to have met the 

section 175A requirement for a 

demonstration that the area will 

maintain the NAAQS for the requisite 

period. Such a demonstration assumes 

continued applicability of prevention of 

significant deterioration requirements 

and any control measures already in the 

SIP and that Federal measures will 

remain in place through the end of the 

second 10-year maintenance period, 

absent a showing consistent with 

section 110(l) that such measures are 

not necessary to assure maintenance. 

Tables 2a and 2b present the design 

values for the Clarksville-Hopkinsville 

Area over the 2007–2020 period. As 

shown in Tables 2a and 2b, the 

Hopkinsville monitor has been well 

below the level of the 1997 8-hour 

ozone NAAQS since the Area was 

redesignated to attainment, and the 

most current design value is below the 

level of 85 percent of the NAAQS, 

consistent with prior LMP guidance. 


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16See the spreadsheet titled ‘‘Ozone Monitoring 

Site Design Values for 2008 through 2017 and for 

2023’’ at https://www.epa.gov/airmarkets/memoand-supplemental-information-regarding-interstatetransport-sips-2015-ozone-naaqs. 

17The 2017 NEI is the most recent NEI, but it was 

unavailable to Tennessee when the State developed 

its SIP revision. 

18The projected emissions data is available at 

https://www.epa.gov/air-emissions-modeling/2014-

2016-version-7-air-emissions-modeling-platforms. 

19EPA’s emissions projections to 2028 were made 

from the 2011 NEI, as that iteration of the NEI was 

the most recently available version when the 

projection work was performed. 

TABLE 2a—1997 8-HOUR OZONE NAAQS DESIGN VALUES (ppm) AT THE MONITORING SITE IN THE CLARKSVILLEHOPKINSVILLE, TN-KY AREA FOR THE 2007–2013 TIME PERIOD

Location County State AQS Site 

ID 

2005–2007 

DV 

2006–2008 

DV 

2007–2009 

DV 

2008–2010 

DV 

2009–2011 

DV 

2010–2012 

DV 

2011–2013 

DV 

Hopkinsville ................ Christian ..................... KY 21–047– 

0006 

0.081 0.078 * 0.074 0.069 0.070 0.073 0.069 

TABLE 2b—1997 8-HOUR OZONE NAAQS DESIGN VALUES (ppm) AT THE MONITORING SITE IN THE CLARKSVILLEHOPKINSVILLE, TN-KY AREA FOR THE 2014–2020 TIME PERIOD

Location County State AQS Site 

ID 

2012–2014 

DV 

2013–2015 

DV 

2014–2016 

DV 

2015–2017 

DV 

2016–2018 

DV 

2017–2019 

DV 

2018–2020 

DV 

Hopkinsville ................ Christian ..................... KY 21–047– 

0006 

0.067 0.063 0.062 0.061 0.060 0.058 0.058 

* The Hopkinsville, KY site (AQS ID: 21–047–0006) was operated by the Tennessee Valley Authority (TVA) until 2008. In 2008, the Kentucky Division for Air Quality 

began operation of an ozone monitor at the site (designated in AQS as Parameter Occurrence Code (POC) 2), and TVA discontinued operation of its POC 1 ozone 

monitor at the end of 2008. Both monitors met completeness requirements for the years that they operated during 2007–2009. AQS does not combine data from different POCs when calculating a design value for the 1997 Ozone NAAQS. However, to accurately present the data in the Table, a 2007–2009 design value was calculated using the combined datasets from the TVA and KY monitors. In 2008, when both monitors collected complete data, the KY monitor data was used because it 

is flagged as certified in AQS, while the 2008 TVA data is not. The combined 2007–2009 DV using 2007 data from the TVA monitor and 2008–2009 data from the KY 

monitor is 74 parts per billion and is shown in the Table. 

Therefore, the Montgomery County 

Area is eligible for the LMP option, and 

EPA proposes to find that the long 

record of monitored ozone 

concentrations that attain the NAAQS, 

together with the continuation of 

existing VOC and NOx emissions 

control programs, adequately provide 

for the maintenance of the 1997 8-hour 

ozone NAAQS in Montgomery County 

through the second 10-year maintenance 

period and beyond. 

Additional supporting information 

that the Area is expected to continue to 

maintain the NAAQS can be found in 

projections of future year design values 

that EPA recently completed to assist 

states with development of interstate 

transport SIPs for the 2015 ozone 

NAAQS.16 Those projections, made for 

the year 2023, show that the highest 

design value in the ClarksvilleHopkinsville Area is expected to be 

0.056 ppm. 

2. Stability of Ozone Levels 

As discussed above, the Montgomery 

County Area has maintained air quality 

well below the 1997 8-hour ozone 

NAAQS over the past thirteen years. 

Additionally, the design value data 

shown within Tables 2a and 2b 

illustrates that ozone levels have been 

relatively stable over this timeframe, 

with an overall downward trend. For 

example, the data within Tables 2a and 

2b indicates that the largest year over 

year change in design value at any one 

monitor during these thirteen years was 

five parts per billion which occurred 

between the 2007–2009 design value 

and the 2008–2010 design value, and it 

represented only a six percent change. 

Furthermore, the overall trend in design 

values for the Clarksville-Hopkinsville 

Area between 2007–2020 shows a 

decrease of 23 parts per billion at the 

Hopkinsville monitor (AQS Site ID 21– 

047–0006). This downward trend in 

ozone levels, coupled with the relatively 

small, year-over-year variation in ozone 

design values, makes it reasonable to 

conclude that Montgomery County Area 

will not exceed the 1997 8-hour ozone 

NAAQS during the second 10-year 

maintenance period. 

3. Projected Emissions 

Although under the LMP option there 

is no requirement to project emissions 

over the maintenance period, TDEC 

included an analysis of ozone precursor 

emissions trends expected over the 

course of the second 10-year 

maintenance period. TDEC provided a 

VOC and NOx emissions trends analysis 

from 2014 to 2028. Tennessee selected 

2014 as a baseline for the projection 

because that is the most recent year for 

which a complete set of data was 

available from EPA’s National 

Emissions Inventory (NEI) database at 

the time the State developed its second 

maintenance plan for the Area.17

Projected emissions data for the year 

2028 were obtained from EPA,18 and 

these data represent EPA emissions 

projections that are available for a date 

furthest out into the future.19 The 

emissions projection trends show that 

between 2014 and 2028, VOC emissions 

are estimated to fall by approximately 

43 percent, and NOx emissions are 

estimated to fall by approximately 56 

percent within the Montgomery County 

Area. These projected declining 

emissions trends further support the 

conclusion that it is unlikely that the 

Area would violate the 1997 8-hour 

ozone NAAQS in the future. Table 3 

presents a summary of projected 

emissions for 2028 contained in the 

maintenance plan. 

TABLE 3—2028 TYPICAL SUMMER DAY 8-HOUR OZONE EMISSIONS FOR THE MONTGOMERY COUNTY AREA

[tons/day] 

Source category VOC 

emissions 

NOX

emissions 

Fire ........................................................................................................................................................................... 0.58 0.02 

Nonpoint ................................................................................................................................................................... 5.31 1.36 


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I I I I I I I I I 

I I I I I I I I I 
Federal Register / Vol. 86, No. 182 / Thursday, September 23, 2021 / Proposed Rules 52869 

20 Kentucky’s network plan is available at https:// 

www.tn.gov/content/dam/tn/environment/air/

documents/apcairqualitymonitoring/2020

%20Tennessee%20Annual%20Monitoring

%20Network%20Plan%20-%20Comment

%20Update.pdf. 

21See 71 FR 4047 (January 25, 2006). 

22 If QA/QC data indicates a violating design 

value for the 8-hour ozone NAAQS, then the 

triggering event will be the date of the design value 

violation, and not the final QA/QC date. However, 

if initial monitoring data indicates a possible design 

value violation but later QA/QC indicates that a 

NAAQS violation did not occur, then a triggering 

event will not have occurred, and contingency 

measures will not need to be implemented. 

23See the Contingency Plan section of the LMP 

for further information regarding the contingency 

plan, including measures that Tennessee will 

consider for adoption if the trigger is activated. 

TABLE 3—2028 TYPICAL SUMMER DAY 8-HOUR OZONE EMISSIONS FOR THE MONTGOMERY COUNTY AREA—Continued 

[tons/day] 

Source category VOC 

emissions 

NOX

emissions 

Nonroad ................................................................................................................................................................... 1.12 0.67 

Onroad ..................................................................................................................................................................... 1.43 2.15 

Point ......................................................................................................................................................................... 0.73 0.31 

Total .................................................................................................................................................................. 9.17 4.51 

C. Monitoring Network and Verification 

of Continued Attainment 

EPA periodically reviews the ozone 

monitoring network that the 

Commonwealth of Kentucky operates 

and maintains in Christian County, in 

accordance with 40 CFR part 58. This 

network plan, which is submitted 

annually to EPA, is consistent with the 

ambient air monitoring network 

assessment. The annual network plan 

developed by the Kentucky Division for 

Air Quality (KDAQ) follows a public 

notification and review process. EPA 

has reviewed and approved the 2020 

Ambient Air Monitoring Network Plan 

(‘‘2020 Annual Network Plan’’).20

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, KDAQ’s monitoring 

network in the Clarksville-Hopkinsville 

Area has been approved by EPA in 

accordance with 40 CFR part 58, and 

Kentucky committed, in its SIPapproved maintenance plan,21 to 

continue to maintain a network in 

accordance with EPA requirements. 

TDEC supports continued ozone 

monitoring by KDAQ. EPA proposes to 

find that KDAQ’s monitoring network is 

adequate to verify continued attainment 

of the 1997 8-hour ozone NAAQS in the 

Montgomery County Area. 

D. Contingency Plan 

Section 175A(d) of the Act 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. These contingency 

measures are required to be 

implemented expeditiously once they 

are triggered by a future violation of the 

NAAQS or some other trigger. The state 

should identify specific triggers which 

will be used to determine when the 

contingency measures need to be 

implemented. 

The LMP states that the trigger is a 

Quality Assured/Quality Controlled 

(QA/QC) violating design value of the 

1997 8-hour ozone NAAQS in the 

Clarksville-Hopkinsville Area.22 If this 

trigger is activated, the maintenance 

plan requires Tennessee to conduct a 

study to determine the cause of the 

higher ozone value, whether from an 

event not likely to recur or from an 

increasing trend in emissions that 

threatens the continued maintenance of 

the NAAQS. Tennessee will adopt and 

implement appropriate contingency 

measures tailored to the source of the 

violation (or increased concentrations) 

as expeditiously as practicable, but no 

later than 18 to 24 months after the 

trigger event.23

EPA proposes to find that the 

contingency provisions in Tennessee’s 

second maintenance plan for the 1997 8- 

hour Ozone NAAQS meet the 

requirements of the CAA section 

175A(d). 

E. Conclusion 

EPA proposes to find that the 

Montgomery County Area LMP for the 

1997 8-hour ozone NAAQS includes an 

approvable update 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 1997 8-hour 

ozone NAAQS. EPA also proposes to 

find that the Montgomery County Area, 

qualifies for the LMP option, and 

adequately demonstrates maintenance 

of the 1997 8-hour ozone NAAQS 

through the documentation of 

monitoring data showing maximum 

1997 8-hour ozone levels well below the 

NAAQS and historically stable design 

values. EPA believes the Montgomery 

County Area’s LMP, which retains all 

existing control measures in the SIP, is 

sufficient to provide for maintenance of 

the 1997 8-hour ozone NAAQS in 

Montgomery County over the second 

maintenance period (i.e., through 2025) 

and thereby satisfies the requirements 

for such a plan under CAA section 

175A(b). EPA is therefore proposing to 

approve Tennessee’s June 23, 2020, 

submission of the Montgomery County 

Area’s LMP as a revision to the 

Tennessee 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 (MVEB) 

contained in the control strategy SIP 

revision or maintenance plan. See 40 

CFR 93.101, 93.118, and 93.124. A 

MVEB is defined as ‘‘the 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, 


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52870 Federal Register / Vol. 86, No. 182 / Thursday, September 23, 2021 / Proposed Rules 

24A conformity determination that meets other 

applicable criteria in Table 1 of paragraph (b) of this 

section (93.109(e)) is still required, including the 

hot-spot requirements for projects in CO, PM10, and 

fine particulate matter (PM2.5) areas. 

allocated to highway and transit vehicle 

use and emissions.’’ See 40 CFR 93.101. 

Under the conformity rule, LMP areas 

may demonstrate conformity without a 

regional emissions analysis. See 40 CFR 

93.109(e). On September 22, 2005, EPA 

made a finding that the MVEBs for the 

first 12 years of the 1997 8-hour ozone 

maintenance plan for the Montgomery 

County Area were adequate for 

transportation conformity purposes. In a 

Federal Register notice dated 

September 22, 2005, EPA notified the 

public of that finding. See 70 FR 55559. 

These new MVEBs became effective 

November 21, 2005. After approval of 

this LMP or an adequacy finding for this 

LMP, there is no requirement to meet 

the budget test pursuant to the 

transportation conformity rule for the 

maintenance area. All actions that 

would require a transportation 

conformity determination for the 

Montgomery County 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 as a result of EPA’s 

adequacy finding for the LMP. See 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. Specifically, for such 

determinations, RTPs, TIPs and 

transportation projects still will have to 

demonstrate that they are fiscally 

constrained (40 CFR 93.108) and meet 

the criteria for consultation (40 CFR 

93.105) and Transportation Control 

Measure implementation in the 

conformity rule provisions (40 CFR 

93.113) as well as meet the hot-spot 

requirements for projects (40 CFR 

93.116).24 Additionally, conformity 

determinations for RTPs and TIPs must 

be determined no less frequently than 

every four years, and conformity of plan 

and TIP amendments and transportation 

projects is demonstrated in accordance 

with the timing requirements specified 

in 40 CFR 93.104. In addition, in order 

for projects to be approved they must 

come from a currently conforming RTP 

and TIP. See 40 CFR 93.114 and 40 CFR 

93.115. 

VI. Proposed Action 

Under sections 110(k) and 175A of the 

CAA and for the reasons set forth above, 

EPA is proposing to approve the 

Montgomery County Area LMP for the 

1997 8-hour ozone NAAQS, submitted 

by TDEC on June 23, 2020, as a revision 

to the Tennessee SIP. EPA is proposing 

to approve the Montgomery County 

Area LMP because it includes an 

acceptable update of the various 

elements of the 1997 8-hour ozone 

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 Montgomery 

County Area qualifies for the LMP 

option and that, therefore, the 

Montgomery County Area’s LMP 

adequately demonstrates maintenance 

of the 1997 8-hour ozone NAAQS 

through documentation of monitoring 

data showing maximum 1997 8-hour 

ozone levels well below the NAAQS 

and continuation of existing control 

measures. EPA believes that the 

Montgomery County Area’s 1997 8-Hour 

Ozone LMP is sufficient to provide for 

maintenance of the 1997 8-hour ozone 

NAAQS in Montgomery County over the 

second 10-year maintenance period, 

through 2025, and thereby satisfy the 

requirements for such a plan under CAA 

section 175A(b). 

VII. Statutory and Executive Order 

Reviews 

Under the CAA, the Administrator is 

required to approve a SIP submission 

that complies with the provisions of the 

Act and applicable Federal regulations. 

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. This action merely proposes to 

approve state law as meeting Federal 

requirements and does not impose 

additional requirements beyond those 

imposed by state law. For that reason, 

this 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 13563 (76 FR 3821, 

January 21, 2011); 

• Does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act (44 

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

• Is certified as not having a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act (5 

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

• Does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4); 

• Does not have Federalism 

implications as specified in Executive 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not an economically significant 

regulatory action based on health or 

safety risks subject to Executive Order 

13045 (62 FR 19885, April 23, 1997); 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of 

Section 12(d) of the National 

Technology Transfer and Advancement 

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

application of those requirements would 

be inconsistent with the CAA; and 

• Does not provide EPA with the 

discretionary authority to address, as 

appropriate, disproportionate human 

health or environmental effects, using 

practicable and legally permissible 

methods, under Executive Order 12898 

(59 FR 7629, February 16, 1994). 

The SIP is not approved to apply on 

any Indian reservation land or in any 

other area where EPA or an Indian tribe 

has demonstrated that a tribe has 

jurisdiction. In those areas of Indian 

country, the rule does not have tribal 

implications as specified by Executive 

Order 13175 (65 FR 67249, November 9, 

2000), nor will it impose substantial 

direct costs on tribal governments or 

preempt tribal law. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Nitrogen oxides, Ozone, Reporting and 

recordkeeping requirements, Volatile 

organic compounds. 

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

Dated: September 1, 2021. 

John Blevins, 

Acting Regional Administrator, Region 4. 

[FR Doc. 2021–20349 Filed 9–22–21; 8:45 am] 

BILLING CODE 6560–50–P 


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