This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

9884 

Vol. 86, No. 30 

Wednesday, February 17, 2021 

1See part D of title I of the Clean Air Act and 

EPA’s Fine Particulate Matter National Ambient Air 

Quality Standards: State Implementation Plan 

Requirements (72 FR 20586, April 25, 2007). 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Parts 52 and 81 

[EPA–R10–OAR–2020–0190; FRL–10014– 

37–Region 10] 

Air Plan Approval; ID: Logan UtahIdaho PM2.5 Redesignation to 

Attainment and Maintenance Plan 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to 

redesignate the Idaho portion of the 

Logan, Utah-Idaho fine particulate 

matter (PM2.5) nonattainment area 

(Logan UT-ID NAA) to attainment for 

the 2006 PM2.5 National Ambient Air 

Quality Standard (NAAQS). EPA is also 

proposing to approve a maintenance 

plan for the area demonstrating 

continued compliance with the 2006 

PM2.5 NAAQS through 2031, which the 

Idaho Department of Environmental 

Quality (IDEQ) submitted along with the 

redesignation request on September 13, 

2019, for inclusion into the Idaho State 

Implementation Plan (SIP). 

Additionally, EPA is proposing to 

approve the 2031 motor vehicle 

emissions budgets included in Idaho’s 

maintenance plan for PM2.5, nitrogen 

oxides (NOX) and volatile organic 

compounds (VOC). EPA is proposing 

this action pursuant to the Clean Air Act 

(CAA or the Act). 

DATES: Comments must be received on 

or before March 19, 2021. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R10– 

OAR–2020–0190, 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 

electronically submit any information 

you consider to be Confidential 

Business Information (CBI) or other 

information the disclosure of which 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://

www.epa.gov/dockets/commenting-epadockets. 

FOR FURTHER INFORMATION CONTACT: 

Adam Clark, (206) 553–1495, 

clark.adam@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document whenever 

‘‘we,’’ ‘‘us,’’ or ‘‘our’’ is used, it is 

intended to refer to EPA. 

Table of Contents 

I. Background 

II. Requirements for Redesignation to 

Attainment 

III. EPA’s Analysis of Idaho’s Submittal 

A. Attainment Determination 

B. Applicable Requirements Under Section 

110 and Part D of the CAA 

1. CAA Section 110 General SIP 

Requirements 

2. Part D of Title I Requirements 

3. Fully Approved SIP Under CAA Section 

110(k) 

C. Improvement in Air Quality Due to 

Permanent and Enforceable Measures 

D. Fully Approved Maintenance Plan 

1. Attainment Inventory 

2. Maintenance Demonstration 

3. Monitoring Network 

4. Verification of Continued Attainment 

5. Contingency Plan 

E. Requirements for Transportation 

Conformity and Motor Vehicle Emissions 

Budgets (MVEBs) 

IV. Proposed Action 

V. Statutory and Executive Order Reviews 

I. Background 

On October 17, 2006 (71 FR 61144), 

EPA revised the level of the 24-hour 

PM2.5 NAAQS, lowering the primary 

and secondary standards from the 1997 

standard of 65 micrograms per cubic 

meter (mg/m3) to 35 mg/m3. On 

November 13, 2009, EPA designated a 

portion of Franklin County, Idaho in 

addition to portions of Cache County, 

Utah nonattainment for the 2006 24- 

hour PM2.5 NAAQS (74 FR 58688). This 

cross-boundary nonattainment area is 

referred to as the Logan, UT-ID PM2.5

NAA. 

The boundaries of the Logan, UT-ID 

PM2.5 NAA roughly conform to the 

geographic boundaries of the Cache 

Valley. The Cache Valley is an isolated, 

bowl-shaped valley measuring 

approximately 60 kilometers north to 

south and 20 kilometers east to west and 

almost entirely surrounded by mountain 

ranges. The Wellsville Mountains lie to 

the west, and on the east lie the Bear 

River Mountains; both are northern 

branches of the Wasatch Range. This 

topography can act as a barrier to air 

movement in the Cache Valley during 

temperature inversions, which occur in 

the winter months and are often the 

cause of elevated concentrations of fine 

particulates. Additional information 

pertaining to the unique issues 

associated with the Logan, UT-ID PM2.5

NAA and studies completed on 

inversions can be found in the docket 

for Utah and Idaho in the November 13, 

2009, final designations action for the 

2006 24-Hour PM2.5 NAAQS (74 FR 

58688). 

The nonattainment designation of the 

Logan UT-ID PM2.5 NAA required Idaho 

to prepare and submit an attainment 

plan to meet statutory and regulatory 

requirements in the Idaho portion of the 

Logan, UT-ID PM2.5 NAA.1 IDEQ 

submitted this attainment plan to EPA 

on December 14, 2012, and 

supplemented the attainment plan on 

December 24, 2014. The attainment plan 

addressed specific required elements, 

including but not limited to the 

following elements: Emissions 

inventory, Reasonably Available Control 

Measures/Technology (RACM/RACT), 

attainment demonstration, contingency 

measures, and Motor Vehicle Emissions 

Budgets (MVEBs). EPA approved the 

baseline emissions inventory on July 18, 

2014 (79 FR 41904) and the control 

measures on March 25, 2014 (79 FR 

16201). EPA approved the control 

measures in the attainment plan as 

meeting RACM/RACT and disapproved 

contingency measures on January 4, 

2017 (82 FR 729). EPA approved the 

attainment demonstration on August 8, 


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2 Idaho’s submission incorporated by reference 

EPA’s August 24, 2016 (81 FR 58010) rule changes 

to 40 CFR 51.165 promulgated under CAA subpart 

4, part D. 

3See ‘‘State Implementation Plans; General 

Preamble for the Implementation of Title I of the 

Clean Air Act Amendments of 1990,’’ 57 FR 13498, 

April 16, 1992. 

4See 83 FR 52983, October 19, 2018. 

2017 (82 FR 37025). We also approved 

a separate, March 20, 2018, Idaho SIP 

revision as meeting applicable part D 

nonattainment new source review (NSR) 

requirements on August 20, 2018 (83 FR 

42033).2 Most recently, we approved the 

attainment plan as meeting the 

Reasonable Further Progress (RFP), 

Quantitative Milestone (QM), and 

MVEB requirements on February 20, 

2020 (85 FR 9664). 

On September 8, 2017 (82 FR 42447), 

EPA granted two, one-year extensions, 

under CAA section 188(d), to the 

December 31, 2015 Moderate attainment 

date for the 2006 24-hour PM2.5 Logan, 

UT-ID NAA. On October 19, 2018, EPA 

finalized a determination that the 

Logan, UT-ID PM2.5 NAA had attained 

the 2006 primary and secondary 24- 

hour PM2.5 NAAQS (‘‘Determination of 

Attainment’’) by the December 31, 2017, 

attainment date (83 FR 52983). 

Additionally, EPA finalized a 

determination that the obligation to 

submit any remaining attainmentrelated SIP revisions arising from 

classification of the Logan, UT-ID NAA 

as Moderate under subpart 4 of part D 

(of title I of the Act) for the 2006 24- 

hour PM2.5 NAAQS are not applicable 

for so long as the area continues to 

attain the 2006 24-hour PM2.5 NAAQS. 

See 40 CFR 51.1015(a) (known as a 

‘‘Clean Data Determination’’ or ‘‘CDD’’). 

II. Requirements for Redesignation to 

Attainment 

The CAA provides the requirements 

for redesignating a nonattainment area 

to attainment. Specifically, section 

107(d)(3)(E) of the CAA, 42 U.S.C. 

7407(d)(3)(E), allows for redesignation 

provided that: (1) EPA determines that 

the area has attained the applicable 

NAAQS; (2) EPA has fully approved the 

applicable implementation plan for the 

area under section 110(k) of the CAA; 

(3) EPA determines that the 

improvement in air quality is due to 

permanent and enforceable reductions 

in emissions resulting from 

implementation of the applicable SIP 

and applicable federal air pollutant 

control regulations and other permanent 

and enforceable reductions; (4) EPA has 

fully approved a maintenance plan for 

the area as meeting the requirements of 

section 175A of the CAA; and (5) the 

state containing such area has met all 

requirements applicable to the area 

under section 110 and part D of the 

CAA. In this proposed action, EPA will 

review CAA section 107(d)(3)(E) 

requirements (2) and (5) together as part 

of our evaluation of Idaho’s 

redesignation request. 

EPA has provided guidance on 

redesignation in the ‘‘General 

Preamble,’’ 3 and has provided further 

guidance on processing redesignation 

requests in the following documents: (1) 

‘‘Procedures for Processing Requests to 

Redesignate Areas to Attainment,’’ 

Memorandum from John Calcagni, 

Director, Air Quality Management 

Division, September 4, 1992 (hereafter 

the ‘‘Calcagni Memo’’); (2) ‘‘State 

Implementation Plan (SIP) Actions 

Submitted in Response to Clean Air Act 

(CAA) Deadlines,’’ Memorandum from 

John Calcagni, Director, Air Quality 

Management Division, October 28, 1992; 

and (3) ‘‘Part D New Source Review 

(Part D NSR) Requirements for Areas 

Requesting Redesignation to 

Attainment,’’ Memorandum from Mary 

D. Nichols, Assistant Administrator for 

Air and Radiation, October 14, 1994. 

These documents are included in the 

Docket for this proposed action. 

III. EPA’s Analysis of Idaho’s Submittal 

EPA is proposing to redesignate the 

Franklin County, ID portion of the 

Logan UT-ID NAA to attainment for the 

2006 24-hour PM2.5 NAAQS and 

proposing to approve into the Idaho SIP 

the associated maintenance plan. EPA’s 

proposed approval of the redesignation 

request and maintenance plan is based 

upon EPA’s determination that the area 

continues to attain the 2006 24-hour 

PM2.5 NAAQS and that all other 

redesignation criteria have been met for 

the area. The following is a description 

of how Idaho’s September 13, 2019, 

submittal satisfies the requirements of 

section 107(d)(3)(E) of the CAA for the 

2006 24-hour PM2.5 standard. 

A. Attainment Determination 

To redesignate an area from 

nonattainment to attainment, the CAA 

requires EPA to determine that the area 

has attained the applicable NAAQS 

(CAA section 107(d)(3)(E)(i)). Whether 

an area has attained the 2006 24-hour 

PM2.5 NAAQS is based upon measured 

air quality levels at each eligible 

monitoring site with a complete threeyear period to produce a design value 

equal to or below 35 mg/m3. See 40 CFR 

part 50 and 40 CFR part 50, appendix 

N. A state must demonstrate that an area 

has attained the 2006 24-hour PM2.5

NAAQS through submittal of ambient 

air quality data from an ambient air 

monitoring network representing 

maximum PM2.5 concentrations. The 

data must be quality assured, qualitycontrolled and certified in the EPA’s Air 

Quality System (AQS) and it must show 

that the three-year average of valid PM2.5

98th percentile mass concentrations is 

equal to or below the 2006 24-hour 

PM2.5 NAAQS (35 mg/m3), pursuant to 

40 CFR 50.13. In making this showing, 

three consecutive years of complete air 

quality data must be used. 

As noted, on October 19, 2018, EPA 

finalized a Determination of Attainment 

for the Logan, UT-ID PM2.5 NAA based 

upon quality-assured and certified 

ambient air quality monitoring data for 

the period of 2015–2017 (83 FR 52983). 

The monitoring data used as the basis 

for the Determination of Attainment 

under CAA section 188(b)(2) is provided 

in Table 1 of this document. 

TABLE 1—LOGAN UT-ID AREA DESIGN VALUES FROM 2018 CDD 4

Monitor AQS site ID 

98th percentile value (μg/m3) 2015–2017 

design value 2015 2016 2017 

Smithfield, UT ...................................................................... 490050007 a 28.9 34.0 36.0 a 33 

Franklin, ID ........................................................................... 160410001 18.8 33.3 b 38.3 b 30 

aThis value combines monitor data from the Logan, UT and Smithfield, UT monitors. EPA concurred on exceptional events in the October 19, 

2018 (83 FR 52983) action and the specified data was excluded. bThis value includes 1-in-3 day monitoring frequency from January 1–August 9, 2017, and daily monitoring frequency from August 10–December 31, 2017. 


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5As defined in 40 CFR part 50, Appendix N, 

section (1)(c). 

6See https://www.epa.gov/air-trends/air-qualitydesign-values#report. 

7The Preston monitor does not have a valid 

design value for the 2017–2019 three-year period 

because of an incomplete 2017 quarter 1 which 

cannot be substituted with quarter 1 data at the 

same monitor in 2018 or 2019 per 40 CFR part 50, 

Appendix N, section 4.2(c)(i) because it has below 

50% complete data for that quarter. 

8Please see ‘‘EPA R10 Ambient Monitoring TSD’’ 

in the docket for this proposed action (EPA–R10– 

OAR–2020–0190) on www.regulations.gov. 

EPA has also reviewed the subsequent 

PM2.5 ambient air monitoring data in the 

Logan UT-ID area for the monitoring 

design value 5 periods of 2016–2018 and 

2017–2019. Consistent with the 

requirements at 40 CFR part 50, Idaho 

quality assured, quality-controlled and 

certified this ambient air monitoring 

data in the EPA’s Air Quality System 

(AQS). This air quality data 

demonstrates that the Logan UT-ID area 

continues to attain the 2006 24-hour 

PM2.5 NAAQS. For the 2016–2018 threeyear period, the Smithfield monitor 

recorded a design value of 33 mg/m3.6

The area’s 24-hour PM2.5 design values 

for the 2017–2019 three-year period are 

provided in Table 2 of this document. 

TABLE 2—LOGAN UT-ID CURRENT PM2.5 DESIGN VALUES 7

Monitor AQS site ID 

98th percentile value (μg/m3) Design value 

(3-year 

2017 2018 2019 average) 

Smithfield, UT ...................................................................... 490050007 36.0 27.9 35.1 33 

Preston, ID ........................................................................... 160410002 a 17.3 27.2 30.1 b NA 

aThe Preston monitor operated at a 1-in-3 day monitoring frequency throughout 2017 and did not begin operation until February 24, 2017, 

making the first quarter incomplete for this monitor with less than 50% of data reported. b Due to the incomplete first quarter in 2017, this design value does not meet validity requirements per 40 CFR part 50, Appendix N, section 

4.2(c)(i). 

As Table 2 indicates, the Logan UTID PM2.5 NAA has continued to attain 

the 2006 24-hour PM2.5 NAAQS since 

EPA issued its October 19, 2018, 

Determination of Attainment for the 

area based on the 2015–2017 design 

values shown in Table 1 of this 

document. We note that the Preston, ID 

monitor did not produce a valid design 

value for the 2017–2019 period because 

the monitor did not begin operation 

until February 24, 2017, thus producing 

an incomplete first quarter for that 

monitoring year. Despite this, EPA finds 

that it is appropriate to conclude that 

the area has continued to attain the 

NAAQS since the initial 2015–2017 

period upon which we based our 

October 19, 2018, Determination of 

Attainment, based on uninterrupted 

attainment at the Smithfield, UT 

monitor. A review of concurrent 

monitoring data for the Smithfield and 

Preston monitors provided in Table 2 of 

this document, and discussed in more 

detail in our Technical Support 

Document (TSD) 8 included in the 

docket for this proposed action, shows 

that the Smithfield site typically records 

higher levels of PM2.5 than the Preston 

site, indicating that Smithfield’s 

location is more suitable to demonstrate 

maximum PM2.5 concentrations in the 

Cache Valley. On September 1, 2020, 

Utah and Idaho completed a 

memorandum of understanding (MOU) 

to collectively meet the monitoring 

requirements of 40 CFR part 58, 

Appendix D in the Logan UT-ID 

metropolitan statistical area (MSA), 

allowing Idaho to rely on the Smithfield 

monitor in Utah as the highest 

concentration monitor in the MSA. As 

shown, the Smithfield monitor has 

attained the 2006 24-hour PM2.5 NAAQS 

for the 2015–2017, 2016–2018 and 

2017–2019 design value periods. The 

MOU is included in the docket for this 

proposed action. The TSD also 

demonstrates that it is very unlikely that 

the Preston monitor’s first complete 

valid design value for the 2018–2020 

period could exceed the 2006 PM2.5

NAAQS based on a review of all 

available data recorded at this monitor. 

EPA’s review of the monitoring data 

for 2016–2018 and 2017–2019 supports 

the previous determination that the area 

has attained the 2006 24-hour PM2.5

NAAQS and demonstrates that the area 

continues to attain the standard. As 

discussed further in Section III.D of this 

document, Idaho has committed to 

continue monitoring ambient PM2.5

concentrations in accordance with 40 

CFR part 58. Thus, EPA is proposing to 

determine that the Logan UT-ID PM2.5

NAA attained the 2006 24-hour PM2.5

NAAQS. 

B. Applicable Requirements Under 

Section 110 and Part D of the CAA 

Section 107(d)(3)(E)(ii) and (v) of the 

CAA states that for an area to be 

redesignated to attainment, it must be 

determined that the Administrator has 

fully approved the applicable 

implementation plan for the area under 

CAA section 110(k) and all the 

requirements applicable to the Area 

under section 110 of the CAA (general 

SIP requirements) and part D of Title I 

of the CAA (SIP requirements for 

nonattainment areas) must be met. 

1. CAA Section 110 General SIP 

Requirements 

Section 110(a)(2) of Title I of the CAA 

delineates the general requirements for 

a SIP, which include enforceable 

emissions limitations and other control 

measures, means or techniques, 

provisions for the establishment and 

operation of appropriate devices 

necessary to collect data on ambient air 

quality, and programs to enforce the 

limitations. The general SIP elements 

and requirements set forth in CAA 

section 110(a)(2) include, but are not 

limited to the following: 

• Submittal of a SIP that has been 

adopted by the state after reasonable 

public notice and hearing; 

• Provisions for establishment and 

operation of appropriate procedures 

needed to monitor ambient air quality; 

• Implementation of a source permit 

program; provisions for the 

implementation of Part C requirements 

(PSD); 

• Provisions for the implementation 

of Part D requirements for NSR permit 

programs; 

• Provisions for air pollution 

modeling; and 

• Provisions for public and local 

agency participation in planning and 

emission control rule development. 

CAA section 110(a)(2)(D) requires that 

SIPs contain certain measures to prevent 

sources in a state from significantly 

contributing to air quality problems in 

another state. However, CAA section 

110(a)(2)(D) requirements for a state are 

not linked with a particular 

nonattainment area’s designation and 

classification in that state. EPA believes 

that the requirements linked with a 


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9 81 FR 58010, August 24, 2016. Codified at 40 

CFR part 51, subpart Z. 

10See Section 188(c)(1) of the CAA, 42 U.S.C. 

7513(c)(1), 40 CFR 51.1004(a)(1). See also 

Identification of Nonattainment Classification and 

Deadlines for Submission of State Implementation 

Plan (SIP) Provisions for the 1997 Fine Particle 

(PM2.5) National Ambient Air Quality Standard 

(NAAQS) and 2006 PM2.5 NAAQS (June 2, 2014), 

79 FR 31566, 31567–68. 

particular nonattainment area’s 

designation and classifications are the 

relevant measures to evaluate in 

reviewing a redesignation request. The 

transport SIP submittal requirements, 

where applicable, continue to apply to 

a state regardless of the designation of 

any one particular area in the state. 

Thus, EPA does not believe that these 

requirements are applicable 

requirements for purposes of 

redesignation. 

In addition, EPA believes that the 

other CAA section 110(a)(2) elements 

not connected with nonattainment plan 

submissions and not linked with an 

area’s attainment status are not 

applicable requirements for purposes of 

redesignation because the area will still 

be subject to these requirements after it 

is redesignated. EPA concludes that the 

CAA section 110(a)(2) and part D 

requirements which are linked with a 

particular area’s designation and 

classification are the relevant measures 

to evaluate in reviewing a redesignation 

request, and that CAA section 110(a)(2) 

elements not linked to the area’s 

nonattainment status are not applicable 

for purposes of redesignation. This 

approach is consistent with EPA’s 

existing policy on applicability of 

conformity (i.e., for redesignations) and 

oxygenated fuels requirement. See 

Reading, Pennsylvania, proposed and 

final rulemakings (61 FR 53174, October 

10, 1996), (62 FR 24826, May 7, 1997); 

Cleveland-Akron-Lorain, Ohio final 

rulemaking (61 FR 20458, May 7, 1996); 

and Tampa, Florida, final rulemaking 

(60 FR 62748, December 7, 1995). See 

also, the discussion on this issue in the 

Cincinnati, Ohio redesignation (65 FR at 

37890, June 19, 2000), and in the 

Pittsburgh-Beaver Valley, Pennsylvania 

redesignation (66 FR at 53099, October 

19, 2001). 

EPA has reviewed the Idaho SIP and 

has concluded that it meets the general 

SIP requirements under Section 

110(a)(2) of the CAA to the extent they 

are applicable for the purposes of 

redesignation. EPA has previously 

approved provisions of Idaho’s SIP as 

demonstrating compliance with the 

CAA section 110(a)(2) requirements for 

the 2006 PM2.5 NAAQS (79 FR 40662, 

July 14, 2014). These requirements are, 

however, statewide requirements that 

are not linked to the PM2.5

nonattainment status of the Logan, UTID NAA. Therefore, EPA believes that 

these SIP elements are not applicable 

requirements for purposes of review of 

this proposed redesignation. 

2. Part D of Title I Requirements 

Part D of Title I of the CAA sets forth 

the basic nonattainment plan 

requirements applicable to all 

nonattainment areas at subpart 1 (CAA 

sections 172–176) and requirements 

specific to PM10 and PM2.5 areas at 

subpart 4 (CAA section 189). On August 

24, 2016, EPA promulgated the Fine 

Particulate Matter National Ambient Air 

Quality Standards; State 

Implementation Plan Requirements 

rule.9 This rule implements the 

requirements of Part D of Title I of the 

CAA for areas designated nonattainment 

for any PM2.5 NAAQS. 

In accordance with 40 CFR 51.1015, 

upon a determination by EPA that a 

Moderate PM2.5 nonattainment area has 

attained the PM2.5 NAAQS, the 

requirements for the state to submit an 

attainment demonstration, provisions 

demonstrating that RACM (including 

RACT for stationary sources) shall be 

implemented no later than 4 years 

following the date of designation of the 

area, RFP plan, QMs and QM reports, 

and contingency measures for the area 

shall be suspended until such time as: 

(1) The area is redesignated to 

attainment, after which such 

requirements are permanently 

discharged; or, (2) EPA determines that 

the area has re-violated the PM2.5

NAAQS. 

Those states containing Moderate 

PM2.5 NAAs were required to submit a 

SIP by December 31, 2014, which 

demonstrated attainment of the PM2.5

NAAQS by December 31, 2015.10

Pursuant to CAA section 188(d) and 40 

CFR 51.1005(a), on September 8, 2017, 

EPA extended the attainment date for 

the Logan UT-ID NAA from December 

31, 2015 to December 31, 2017 (82 FR 

42447). As stated in the ‘‘Background’’ 

section, EPA has approved several 

attainment plan elements for the Idaho 

portion of the Logan UT-ID area. 

Specifically, EPA approved the 

following elements of Idaho’s 

attainment plan: Baseline emissions 

inventory (July 18, 2014, 79 FR 41904); 

control measures (March 25, 2014, 79 

FR 16201); RACM/RACT (January 4, 

2017, 82 FR 729); attainment 

demonstration (August 8, 2017, 82 FR 

37025); nonattainment NSR (August 20, 

2018, 83 FR 42033), and RFP, QM and 

MVEB (February 20, 2020, 85 FR 9664). 

Pursuant to 40 CFR 51.1015(a), on 

October 19, 2018, EPA completed a CDD 

for the Logan, UT-ID Moderate PM2.5

NAA. (83 FR 52983). The CDD 

suspended the obligation for Idaho to 

make submissions to meet certain CAA 

requirements related to attainment of 

the NAAQS, including the CAA section 

172(c)(9) requirement to adopt 

contingency measures. 

Determinations of attainment do not 

relieve states from submitting and EPA 

from approving certain Part D planning 

requirements for the 2006 PM2.5

NAAQS. CAA section 172(c)(3) requires 

submission and approval of a 

comprehensive, accurate and current 

inventory of actual emissions. For 

purposes of the PM2.5 NAAQS, this 

emissions inventory should address not 

only direct emissions of PM2.5, but also 

emissions of all precursors to PM2.5

formation, i.e., SO2, NOX, VOC, and 

ammonia. As previously discussed, EPA 

determined that Idaho met the CAA 

section 172(c)(3) comprehensive 

emissions inventory requirement in a 

final rulemaking on July 18, 2014 (79 FR 

41904). 

CAA section 172(c)(4) requires the 

identification and quantification of 

allowable emissions for major new and 

modified stationary sources in an area, 

and CAA section 172(c)(5) and requires 

source permits for the construction and 

operation of new and modified major 

stationary sources anywhere in the 

nonattainment area. EPA first approved 

the requirements of the part D NSR 

permit program for Idaho under subpart 

1 on November 26, 2010 (75 FR 72719). 

Subsequently, on March 20, 2018, Idaho 

submitted rule revisions to meet 

additional part D NSR requirements 

promulgated by the EPA under subpart 

4 (81 FR 58010, August 24, 2016). We 

approved Idaho’s submission on August 

20, 2018 (83 FR 42033). 

Once the Logan, UT-ID PM2.5 NAA is 

redesignated to attainment, the 

prevention of significant deterioration 

(PSD) requirements of part C of the Act 

will apply. Idaho’s PSD regulations are 

codified in the Idaho Administrative 

Procedures Act (IDAPA) at 

58.01.01.200–228 (permit to construct) 

and governed by IDAPA 58.01.01.205 

(permit requirements for new major 

facilities or major modifications in 

attainment or unclassifiable areas). We 

most recently approved revisions to 

Idaho’s PSD program on August 20, 

2018 (83 FR 42033), May 12, 2017 (82 

FR 22083) and August 12, 2016 (81 FR 

53290). EPA finds that Idaho’s PSD 

provisions meet all applicable Federal 

requirements for any area designated 

unclassifiable or attainment, and these 

provisions will become fully effective in 

the Idaho portion of the Logan, UT-ID 


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11 2014 attainment plan SIP submittal, Section 

4.1. 

12See Idaho’s September 13, 2019 submittal at 

Section 5.2. 

PM2.5 NAA upon redesignation of the 

area to attainment. 

CAA section 172(c)(7) requires the SIP 

to meet the applicable provisions of 

CAA section 110(a)(2). As noted above, 

we find that the Idaho SIP meets the 

CAA section 110(a)(2) applicable 

requirements for purposes of 

redesignation. 

For purposes of redesignation to 

attainment for the 2006 24-hour PM2.5

NAAQS, EPA proposes to find that 

Idaho has met all the applicable SIP 

requirements under part D of Title I of 

the CAA. 

3. Fully Approved SIP Under CAA 

Section 110(k) 

As discussed in Sections III.B.1 and 

III.B.2 of this document, for purposes of 

redesignation to attainment for the 2006 

24-hour PM2.5 NAAQS, EPA has fully 

approved all applicable requirements of 

Idaho’s SIP for the Idaho portion of the 

Logan UT-ID area in accordance with 

CAA section 110(k). Therefore, EPA has 

fully approved all applicable 

requirements of the applicable 

implementation plan in accordance 

with CAA section 110(k). 

C. Improvement in Air Quality Due to 

Permanent and Enforceable Measures 

CAA section 107(d)(3)(E)(iii) of the 

CAA provides that for an area to be 

redesignated to attainment, the 

Administrator must determine that the 

improvement in air quality is due to 

permanent and enforceable reductions 

in emissions resulting from 

implementation of the applicable 

implementation plan, implementation 

of applicable Federal air pollutant 

control regulations, and other 

permanent and enforceable reductions. 

On December 14, 2012, IDEQ 

submitted an attainment plan that 

addressed attainment planning 

requirements for the Idaho portion of 

the Logan UT-ID PM2.5 NAA. On 

December 24, 2014, the IDEQ submitted 

a supplement to the 2012 attainment 

plan that included additional analysis. 

Idaho’s December 14, 2012, attainment 

plan submittal included residential 

wood combustion (RWC) ordinances, 

road-sanding agreements, and a wood 

stove change-out program to reduce 

emissions of PM2.5 in the Idaho portion 

of the Logan UT-ID PM2.5 NAA. Each of 

these programs is discussed in detail 

within this section. EPA approved the 

RWC ordinances and road sanding 

agreements into the Idaho SIP on March 

25, 2014 (79 FR 16201), making them 

federally enforceable. EPA approved 

Idaho’s evaluation of, and imposition of, 

RACM and RACT level controls on 

appropriate sources on January 4, 2017 

(82 FR 729). This approval included 

approving the RWC ordinances and 

wood stove change-out program as 

meeting the RACM requirement. 

The RWC ordinances approved as 

RACM on January 4, 2017, apply within 

Franklin County and all six Idaho cities 

on the Idaho side of the Logan UT-ID 

PM2.5 NAA (Franklin, Preston, Weston, 

Dayton, Clifton, and Oxford). EPA 

determined in its approvals that these 

RWC ordinances achieved permanent 

and enforceable emissions reductions. 

Key elements in the current RWC 

ordinances include mandatory burn 

bans issued when PM2.5 has reached or 

is forecasted to reach 75 on the Air 

Quality Index (AQI), which corresponds 

to a PM2.5 concentration of 23.3 mg/m3

and aligns with the RWC ordinances 

applicable within Cache County on the 

Utah side of the Logan UT-ID PM2.5

NAA. All RWC ordinances effective in 

Franklin County prohibit both open 

burning and the use of specified devices 

when an air quality alert is issued. The 

ordinances also prohibit the installation 

of non-EPA-certified devices. Each of 

the adopted ordinances bans open 

burning of any kind during burn ban 

days, bans the sale or installation of 

non-EPA certified devices in new or 

existing buildings, and prohibits the 

construction of any building for which 

a solid fuel burning device is the sole 

source of heat. In its December 14, 2012, 

attainment plan submittal, Idaho 

estimated that maximum reductions for 

this measure are 0.06 tons per day (tpd) 

direct PM2.5, 0.009 tpd nitrogen oxides 

(NOX), and 0.078 tpd volatile organic 

compounds (VOC). 

In our March 25, 2014 action, EPA 

also approved road sanding agreements 

between IDEQ, Franklin County Road 

and Bridge, and the Idaho 

Transportation Department (IDT) to 

reduce the contribution of primary 

PM2.5 from reentrained dust on paved 

roads. According to records submitted 

to Idaho and summarized in the 

submission, IDT used salt in 2014 (409 

tons), 2015 (340 tons), and 2016 (109 

tons) and did not use sand. Franklin 

County Road and Bridge historically 

used a 10:1 ratio of sand and salt; 

however, in the Idaho attainment plan, 

Franklin County committed to use a 4:1 

ratio of sand and salt when anti-skid 

treatment is required. Franklin County 

also agreed to apply brine when 

temperatures are above 22 °F, a measure 

that further reduces the amount of sand 

required by approximately 50%. The 

City of Preston now uses a 2:1 ratio of 

sand and salt at an average of 700 tons 

total per year. In its SIP, IDEQ estimates 

that these road sanding commitments 

would lead to 0.10 tpd reduction in 

direct PM2.5 annually. 

Finally, in its attainment plan, IDEQ 

quantified the emission reduction 

benefits from three woodstove changeout programs on the Idaho side of the 

Logan UT-ID area. These programs were 

conducted in 2006–2007, 2011–2012, 

and 2013–2014. Accordingly, Idaho 

demonstrated in the submission that a 

total of 209 uncertified RWC devices 

have been changed-out since 2006. In 

addition, 39 stoves were removed and 

destroyed through Idaho’s Alternative 

Energy Device tax deduction program. 

In total, 256 wood stoves have been 

changed out on the Idaho side of the 

Logan UT-ID NAA since 2006. As 

described in the supplemental 2014 

attainment plan SIP submittal (applying 

the appropriate temporal profile to 

convert to tons per day), Idaho stated 

these change-outs have led to 

permanent reductions of 0.05 tpd direct 

PM2.5, 0.003 tpd NOX, and 0.13 tpd 

VOC.11 These woodstove change-out 

programs achieved permanent and 

enforceable emissions reductions 

because the RWC ordinances banned the 

sale or installation of non-EPA certified 

devices in new or existing buildings in 

Franklin County jurisdictions. 

IDEQ also noted that Utah adopted 

permanent and enforceable control 

measures into its SIP that have reduced 

PM2.5 and precursor emissions and led 

to the improvement in air quality in the 

Logan UT-ID PM2.5 NAA. IDEQ 

specifically referenced area source rules 

(2015 reductions of 122 lbs/day NOX, 

679 lbs/day PM2.5, 3,665 lbs/day VOC) 

and a vehicle and inspection and 

maintenance program (2015 reductions 

of 0.214 tons/day for NOX and 0.212 

tons/day for VOC) in the Utah portion 

of the Logan UT-ID NAA.12 IDEQ also 

referenced Federal measures, including 

the ‘‘Tier 3 Motor Vehicle Emission and 

Fuel Standards Rule’’ (79 FR 23414), as 

permanent and enforceable reductions 

leading to improvement in air quality, 

and ultimately to attainment, in the 

Logan UT-ID PM2.5 NAA. 

Based on the foregoing evaluation of 

these control measures, EPA proposes to 

determine that the improvement in air 

quality is reasonably attributable to 

permanent and enforceable reductions 

in emissions resulting from 

implementation of the applicable 

implementation plan, implementation 

of applicable Federal air pollutant 

control regulations, and other 

permanent and enforceable reductions. 


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13See Calcagni Memo at 8. 

14See Appendix A of Idaho’s September 13, 2019 

submittal for the apportionment methodology. 

15With the exception of paved road dust 

emissions, which IDEQ calculated using AP–42 

guidance. 16An episodic day was defined as any day from 

November through March during which the daily 

average PM2.5 concentration in Franklin County was 

above 35 mg/m3. A total of 62 days were identified 

that met these criteria at the Logan-Cache Airport 

weather station from 2013 through 2017. The 

hourly meteorological data from these 62 days were 

then averaged to create the final average episodic 

day inputs. 

D. Fully Approved Maintenance Plan 

CAA section 107(d)(3)(E)(iv) requires 

that, for a NAA to be redesignated to 

attainment, EPA must fully approve a 

maintenance plan which meets the 

requirements of CAA section 175A. The 

plan must demonstrate continued 

attainment of the relevant NAAQS in 

the area for at least 10 years after our 

approval of the redesignation. Eight 

years after our approval of a 

redesignation, the State must submit a 

revised maintenance plan 

demonstrating attainment for the 10 

years following the initial 10-year 

period. The maintenance plan must also 

contain a contingency plan to ensure 

prompt correction of any violation of 

the NAAQS. See CAA sections 175A(b) 

and (d). The Calcagni Memo provides 

additional guidance on the content of a 

maintenance plan, stating that a 

maintenance plan should include the 

following elements: (1) An attainment 

emissions inventory; (2) a maintenance 

demonstration showing attainment for 

10 years following redesignation; (3) a 

commitment to maintain the existing 

monitoring network; (4) verification of 

continued attainment; and (5) a 

contingency plan to prevent or correct 

future violations of the NAAQS. The 

following paragraphs describe how each 

of these elements is addressed in 

Idaho’s maintenance plan. 

1. Attainment Inventory 

As discussed in the General Preamble 

(see 57 FR 13498, April 16, 1992) and 

the Calcagni Memo, PM2.5 maintenance 

plans should include an attainment 

emission inventory to identify the level 

of emissions in the area which is 

sufficient to maintain the NAAQS. 

The maintenance plan attainment 

year inventory should include the 

emissions during the time period 

associated with the monitoring data 

showing attainment.13 For the Logan, 

UT-ID PM2.5 NAA, IDEQ determined 

attainment using air quality data from 

2015, 2016, and 2017, the design value 

period relied upon for the EPA’s 

Determination of Attainment (83 FR 

52983, October 19, 2018). The State 

therefore used 2017 to calculate its base 

year attainment inventory, which 

aligned with the 2017 National 

Emissions Inventory (NEI) data available 

for point, area, on-road mobile, and 

nonroad mobile sources. IDEQ then 

projected the 2017 base year inventory 

to both a ‘‘horizon year’’ (a future year 

at least 10 years from the approval date 

of the maintenance plan) of 2031 and an 

interim year of 2026. 

The NEI is compiled at the county 

level, so the State first calculated the 

2017 emissions inventories for Franklin 

County, and then apportioned these 

county-wide inventories to the portion 

of Franklin County included in the 

Logan, UT-ID NAA.14 IDEQ projected 

mobile source emissions using the latest 

version of EPA’s Motor Vehicle 

Emissions Simulator (MOVES) model 

(MOVES2014b). IDEQ used apportioned 

2017 NEI data for the on-road mobile 

source emissions, and used 

MOVES2014b model defaults for the 

nonroad portion of the model, because 

the State has not yet developed input 

files for that version of the model.15 To 

best represent emissions that occur on 

days when the ambient concentrations 

of PM2.5 are of concern, the MOVES 

meteorological inputs were based on an 

average episodic day representing 

conditions present during wintertime 

stagnation events leading to high levels 

of ambient PM2.5 in the Logan UT-ID 

PM2.5 NAA.16 IDEQ ran MOVES2014b to 

calculate on-road and nonroad mobile 

source emissions on an average episodic 

winter day for Franklin County for 

January 2017, 2026 and 2031. Area 

source emissions were apportioned from 

2017 NEI data for individual categories, 

which were projected for the 2026 and 

2031 inventories based on an average 

annual growth rate. No point sources 

were listed in the base year or projected 

future inventories. More detailed 

descriptions of the 2017 base year 

inventory and the 2026 and 2031 

projected inventories can be found in 

section 4 and Appendix A of Idaho’s 

September 13, 2019 submittal, in the 

docket for this action. 

For each of these source categories, 

the pollutants that were inventoried 

include: PM2.5, sulfur dioxide (SO2), 

NOX, VOC, and ammonia (NH3). 

Summary of emission figures from 2017 

base year and the projected inventories 

are provided in Table 3 of this 

document. 

TABLE 3—IDAHO PORTION OF THE LOGAN, UT-ID PM2.5 NAA; ACTUAL EMISSIONS FROM 2017 AND PROJECTED

EMISSIONS FOR 2026 AND 2031 

[Pounds per average episodic winter day] 

Year Source category PM2.5

condensable 

PM2.5

filterable NOX SO2 VOC NH3

2017 ................................. Area ................................. 9.72 208.8 338.8 28.3 1,626.5 868.6 

2017 ................................. Mobile .............................. ...................... 127.3 957.7 1.9 901.2 13.8 

2017 ................................. Nonroad ........................... ...................... 42.5 286.6 0.8 1,189.1 0.7 

2017 ................................. Total .......................... 9.72 378.5 1,583 31 3,716.8 883.1 

2026 ................................. Area ................................. 9.88 222.4 363.5 28.6 2,061.1 872.1 

2026 ................................. Mobile .............................. ...................... 109.4 421.8 2.0 533.1 12.5 

2026 ................................. Nonroad ........................... ...................... 31.2 302.8 0.8 776.4 0.7 

2026 ................................. Total .......................... 9.88 363 1088.1 31.4 3,370.6 885.3 

2031 ................................. Area ................................. 9.97 230 377.2 28.8 2,302.6 874 

2031 ................................. Mobile .............................. ...................... 110.5 297.3 2 396.3 13.2 

2031 ................................. Nonroad ........................... ...................... 29.8 306.7 0.8 732.5 0.7 

2031 ................................. Total .......................... 9.97 370.4 981.2 31.6 3,431.4 887.9 

Projected change (%) .......................................... 2.5 ¥2.2 ¥38 2 ¥7.70 0.5 


jbell on DSKJLSW7X2PROD with PROPOSALS
9890 Federal Register / Vol. 86, No. 30 / Wednesday, February 17, 2021 / Proposed Rules 

17 ‘‘Emissions Inventory Guidance for 

Implementation of Ozone and Particulate Matter 

Following our review, we have 

determined that IDEQ prepared an 

adequate attainment inventory for the 

Idaho portion of the Logan, UT-ID PM2.5

NAA. 

In the September 13, 2019 

submission, Idaho also provided 

inventory information for the Utah 

portion of the Logan, UT-ID NAA. Idaho 

derived this inventory from the Utah 

Division of Air Quality (Utah DAQ), 

which performed a photochemical grid 

modeling analysis using the 

‘‘Comprehensive Air Quality Model 

with Extensions’’ (v. 6.3, http://

www.camx.com/) modeling system for 

the nonattainment area for Utah’s 

attainment, interim, and projected years. 

Utah used linear projections to estimate 

future years to 2035. Utah DAQ’s 

modeling domain included all three of 

the nonattainment areas in UT and 

extended into southern Idaho to include 

the Idaho portion of the Logan UT-ID 

PM2.5 NAA. The methodology for the 

mobile, nonroad and area source 

emissions inventories can be found in 

the Utah DAQ PM2.5 Emissions 

Inventory Preparation Plan (Utah DAQ 

2019), in the docket for this action. 

IDEQ interpolated the Utah DAQ 

projections to 2031 using the average 

annual growth rate for area, mobile, and 

nonroad sources to match the 2031 

horizon year for Idaho’s redesignation 

request. The actual and projected 

emissions in the Utah portion of the 

Logan UT-ID PM2.5 NAA are provided in 

Table 4 of this document. Table 5 of this 

document provides Idaho’s projected 

emissions inventories for the entire 

Logan UT-ID PM2.5 NAA, which is the 

combination of the values in Tables 3 

and 4 of this document. 

TABLE 4—UTAH PORTION OF THE LOGAN, UT-ID PM2.5 NAA; ACTUAL EMISSIONS FROM 2017 AND PROJECTED

EMISSIONS FOR 2026 AND 2031 

[Pounds per average episodic winter day]. 

Year Source category PM2.5

condensable 

PM2.5

filterable NOX SO2 VOC NH3

2017 ................................. Area ................................. 1.83 1,198.17 1,840 60 7,600 26,960 

2017 ................................. Mobile .............................. ...................... 460 7,520 40 4,920 200 

2017 ................................. Nonroad ........................... ...................... 200 1,580 .................... 4,380 ....................

2017 ................................. Total .......................... 1.83 1,858.17 10,940 100 16,900 27,160 

2026 ................................. Area ................................. 2.09 1,277.91 1,400 60 7,760 26,540 

2026 ................................. Mobile .............................. ...................... 260 3,040 20 2,780 180 

2026 ................................. Nonroad ........................... ...................... 120 1,180 .................... 2,540 ....................

2026 ................................. Total .......................... 2.09 1,657.91 5,620 80 13,080 26,720 

2031 ................................. Area ................................. 2.29 1,311.04 1,411.11 60 8,215.56 26,362.22 

2031 ................................. Mobile .............................. ...................... 326.67 3,306.67 20 3,357.78 191.11 

2031 ................................. Nonroad ........................... ...................... 108.89 1,157.78 .................... 2,284.44 ....................

2031 ................................. Total .......................... 2.29 1,746.6 5,875.56 80 13,857.78 26,553.33 

Projected change (%) .......................................... 25.2 ¥6.0 ¥46.3 ¥20 ¥18.0 ¥0.02 

TABLE 5—ENTIRE LOGAN, UT-ID PM2.5 NAA; ACTUAL EMISSIONS FROM 2017 AND PROJECTED EMISSIONS FOR 2026 

AND 2031 

[Pounds per winter day] 

Year Source category PM2.5

condensable 

PM2.5

filterable NOX SO2 VOC NH3

2017 ................................. Area ................................. 11.55 1,406.94 2,178.76 88.27 9,226.45 27,828.63 

2017 ................................. Mobile .............................. ...................... 587.3 8,477.7 41.94 5,821.24 213.76 

2017 ................................. Nonroad ........................... ...................... 242.48 1,866.57 0.76 5,569.08 0.66

2017 ................................. Total .......................... 11.55 2,236.72 12,523.03 130.97 20,616.77 28,043.05 

2026 ................................. Area ................................. 11.98 1,500.33 1,763.48 88.58 9,821.12 27,412.08 

2026 ................................. Mobile .............................. ...................... 369.36 3,461.84 22 3,313.12 192.55 

2026 ................................. Nonroad ........................... ...................... 151.19 1,482.79 0.77 3,316.4 0.66 

2026 ................................. Total .......................... 11.98 2,020.88 6,708.11 111.35 16,450.64 27,605.29 

2031 ................................. Area ................................. 12.26 1,541.06 1,788.33 88.75 10,518.17 27,236.22 

2031 ................................. Mobile .............................. ...................... 437.21 3,603.94 22.05 3,754.04 204.32 

2031 ................................. Nonroad ........................... ...................... 138.73 1,464.52 .78 3,016.94 0.67 

2031 ................................. Total .......................... 12.26 2,117 6,856.79 111.58 17,289.15 27,441.21 

Projected change (%) .......................................... 6.1 ¥5.4 ¥45.2 ¥14.8 ¥16.1 ¥2.1 

Based our review of the emissions 

inventories Idaho provided in its 

September 13, 2019 submittal, shown in 

Tables 3 through 5 of this document, we 

propose to find that Idaho prepared an adequate attainment inventory for the 

Logan, UT-ID PM2.5 NAA.17


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Federal Register / Vol. 86, No. 30 / Wednesday, February 17, 2021 / Proposed Rules 9891 

National Ambient Air Quality Standards (NAAQS) 

and Regional Haze Regulations,’’ May 2017. 

18As stated, Utah and Idaho signed an MOU to 

collectively meet the monitoring requirements of 40 

CFR part 58, Appendix D in the Logan UT-ID MSA 

on September 1, 2020. 

19See EPA’s November 9, 2020 approval of 

Idaho’s 2020 Annual Monitoring Network Plan, in 

the docket for this action. 

2. Maintenance Demonstration 

CAA section 175A requires a state 

seeking redesignation to attainment to 

submit a SIP revision to provide for the 

maintenance of the NAAQS in the area 

‘‘for at least 10 years after the 

redesignation.’’ A state can make this 

demonstration by either showing that 

future emissions of a pollutant or its 

precursors will not exceed the level of 

the attainment inventory, or by 

modeling to show that the future mix of 

sources and emissions rates will not 

cause a violation of the NAAQS. See 

Calcagni Memo, pages 9–10. Idaho 

elected to demonstrate maintenance of 

the 2006 PM2.5 NAAQS for at least ten 

years following redesignation using the 

attainment inventory method. 

IDEQ developed projected 

inventories, provided in Tables 3 

through 5 of this document, to show 

that the Logan UT-ID area will remain 

in attainment through the year 2031. 

These projected inventories, covering an 

interim year of 2026 and a horizon year 

of 2031, show that future emissions of 

NOX, SO2, VOCs, ammonia, and direct 

PM2.5 throughout the NAA will remain 

at or below the 2017 attainment-level 

emissions for the 2006 24-hour PM2.5

NAAQS. As these inventories show, 

emissions from NOX, SO2, VOCs and 

NH3 are projected to decrease between 

2017 and 2031 (Table 5 of this 

document). The emissions of direct 

filterable PM2.5 are projected to decline 

by 5.4% by 2031 (Table 5 of this 

document). 

Although emissions from condensable 

PM2.5 increase by 6.1% by 2031, Idaho 

adequately demonstrated that this 

increase will not prevent maintenance 

of the NAAQS through 2031. The 

condensable fraction of PM2.5 is 0.6% of 

the total PM2.5-Primary levels projected 

for 2031. As depicted in Table 5 of this 

document, the total condensable PM2.5

emissions are projected to increase by 

0.71 pounds per winter day between 

2017 and 2031, while total filterable 

PM2.5 emissions are projected to 

decrease by 119.72 pounds per winter 

day over the same time period. Overall, 

total PM2.5 (sum of filterable and 

condensable PM2.5) is projected to 

decrease by 5.3% from 2017 to 2031. 

EPA has reviewed the documentation 

provided by Idaho for developing the 

2026 and 2031 emissions inventories for 

the Logan UT-ID PM2.5 NAA. Based on 

our review, EPA finds that the 

emissions inventories were prepared in 

accordance with EPA requirements. 

These inventories indicate a decrease in 

PM2.5 and precursor emissions 

throughout the maintenance period, 

therefore EPA is proposing to determine 

that the projected emissions inventories 

in the Idaho maintenance plan 

sufficiently demonstrate that the Logan 

UT-ID PM2.5 NAA will continue to 

maintain the 2006 24-hour PM2.5

standard throughout the maintenance 

period. 

3. Monitoring Network 

Once a NAA has been redesignated to 

attainment, the state must continue to 

operate an appropriate air quality 

monitoring network, in accordance with 

40 CFR part 58, to verify the attainment 

status of the area.18 The maintenance 

plan should contain provisions for 

continued operation of air quality 

monitors that will provide such 

verification. In the maintenance plan, 

IDEQ noted that it currently operates a 

regulatory monitor (the Preston monitor) 

in the Idaho portion of the Logan, UTID PM2.5 NAA, and committed to 

continue operating a regulatory 

monitoring network in Franklin County 

in order to verify continued attainment 

of the PM2.5 NAAQS and track the 

progress of the maintenance plan. IDEQ 

also stated that it will work with EPA 

each year through the air monitoring 

network review process (per 40 CFR 

part 58) to determine the adequacy of 

the monitoring network.19 EPA 

proposes to determine that the 

maintenance plan contains adequate 

provisions for continued operation of an 

air quality monitoring network to verify 

maintenance of the 2006 PM2.5 NAAQS. 

4. Verification of Continued Attainment 

As stated in Section III.D.3 of this 

document, in its maintenance plan, 

Idaho commits to continue to operate a 

regulatory monitoring network in order 

to verify continued attainment of the 

PM2.5 NAAQS in the Idaho portion of 

the Logan UT-ID area. Idaho is also 

required to periodically update the 

emissions inventory for Franklin County 

in accordance with the Annual Air 

Emissions Reporting Requirements Rule 

(AERR) during the maintenance plan 

period. This includes developing annual 

inventories for major point sources and 

a comprehensive periodic inventory 

covering all source categories every 

three years. 

5. Contingency Plan 

CAA section 175A(d) requires that a 

maintenance plan also include 

contingency provisions, as necessary, to 

promptly correct any violation of the 

NAAQS that occurs after redesignation 

of the area to attainment. For the 

purposes of CAA section 175A, a state 

is not required to have fully adopted 

contingency measures that will take 

effect without further action by the state 

in order for the maintenance plan to be 

approved. However, the contingency 

plan is an enforceable part of the SIP 

and should ensure that contingency 

measures are adopted expeditiously 

once they are triggered. The plan should 

discuss the measures to be adopted and 

a schedule and procedure for adoption 

and implementation. The contingency 

plan must require that the state will 

implement all measures contained in 

the Part D nonattainment plan for the 

area prior to redesignation. The state 

should also identify the specific 

indicators, or triggers, which will be 

used to determine when the 

contingency plan will be implemented. 

Idaho’s maintenance plan outlines the 

procedures for the adoption and 

implementation of contingency 

measures to further reduce emissions 

should a violation occur. Idaho’s 

contingency measures include a 

warning level response and an action 

level response. An initial warning level 

response is triggered for the 2006 24- 

hour PM2.5 NAAQS when the 98th 

percentile 24-hour PM2.5 concentration 

for a single calendar year reaches 35.5 

mg/m3 or greater within the area. An 

action level response will be prompted 

by any one of the following: (1) A two 

year average of the 98th percentile 

reaches 35.5 mg/m3 or greater within the 

area; or (2) a violation of the standard 

occurs in the area (i.e. a three-year 

average of the 98th percentile reaches 

35.5 mg/m3 or greater). 

Regardless of which level of response 

is triggered, the State will evaluate all 

appropriate data including air quality 

data, evaluation of wood smoke 

programs and information on wildfires 

or winter power outages to determine 

the cause of the exceedance. IDEQ will 

perform this evaluation within six 

months of the end of the year in which 

the NAAQS is exceeded or violated. 

Should a warning level response be 

triggered, and IDEQ determines that 

additional emissions reductions are 

necessary, the State will adopt and 

implement contingency measures as 

expeditiously as possible and no later 

than 18 months from the determination 

of a single year exceedance based on 

quality assured data. Should an action 


jbell on DSKJLSW7X2PROD with PROPOSALS
9892 Federal Register / Vol. 86, No. 30 / Wednesday, February 17, 2021 / Proposed Rules 

20See 40 CFR 93.102(b)(2)(iv)–(v) and (b)(3). 

21See 40 CFR 93.118. 

22See document titled ‘‘EPA R10 MVEB and 

MOVES TSD’’ in the docket for this proposed action 

(EPA–R10–OAR–2020–0190) on 

www.regulations.gov. 

level response be triggered, 

implementation of necessary control 

measures will take place as 

expeditiously as possible, but in no 

event later than 18 months after IDEQ 

determines, based on quality-assured 

ambient data, that an action level trigger 

has been exceeded. 

Idaho has identified the following 

potential contingency measures for the 

maintenance plan: 

• Measures to address emissions from 

residential wood combustion, including 

the potential implementation of a burn 

ban in the maintenance area at a lower 

threshold than currently in place in the 

ordinances for the six cities in the Idaho 

portion of the Logan UT-ID PM2.5 NAA. 

The current ordinances trigger a burn 

ban when the Air Quality Index (AQI) 

level reaches 75. 

• Additional measures to address 

other PM2.5 sources identified in the 

emissions inventory such as on-road 

and nonroad vehicles, industrial 

sources, and dust. 

Based on our analysis of Idaho’s 

submittal, we propose to find that the 

contingency measure provisions 

provided in Idaho’s Logan, UT-ID PM2.5

maintenance plan are sufficient and 

meet the requirements of CAA section 

175A(d). 

E. Requirements for Transportation 

Conformity and Motor Vehicle 

Emissions Budgets (MVEBs). 

Transportation conformity is required 

by CAA section 176(c). EPA’s 

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 or 

not they conform. 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. Thus, 

EPA’s conformity rule requires a 

demonstration that emissions from a 

Metropolitan Planning Organization’s 

(MPO’s) Regional Transportation Plan 

and Transportation Improvement 

Program, involving Federal Highway 

Administration (FHWA) or Federal 

Transit Administration (FTA) funding 

or approval, are consistent with the 

MVEB(s) contained in a control strategy 

SIP revision or maintenance plan (40 

CFR 93.101, 93.118, and 93.124). A 

MVEB is the level of mobile source 

emissions of a pollutant relied upon in 

the attainment or maintenance 

demonstration to attain or maintain 

compliance with the NAAQS in the 

nonattainment or maintenance area. 

A PM2.5 maintenance plan should 

identify MVEBs for direct PM2.5, NOX

and all other PM2.5 precursors from onroad mobile source emissions that are 

determined to significantly contribute to 

PM2.5 levels in the area.20 To determine 

which precursor pollutants are required 

to have an MVEB, IDEQ reviewed PM2.5

speciation at the Franklin monitor. 

Based on PM2.5 speciation data and the 

local emissions inventory composition 

for each pollutant, IDEQ determined 

that in addition to NOX and direct 

PM2.5, the maintenance plan should also 

include an MVEB for VOCs because 

they are important precursors to 

secondary formation PM2.5. The State 

excluded direct PM2.5 emissions from 

paved road dust from the MVEBs in 

accordance with 40 CFR 93.102(b)(3), as 

these emissions made up only 1% of 

total wintertime contributions at the 

Franklin monitor. Vehicle emissions of 

SO2 and NH3 were also found to 

contribute minimally to PM2.5 in the 

area and therefore the maintenance plan 

does not include MVEBs for these 

precursors in accordance with 40 CFR 

93.102(b)(2)(v). See Section 6 of Idaho’s 

maintenance plan, in the docket for this 

action, for further analysis of the 

pollutants and precursors and the 

decisions on whether or not MVEBs 

were required for the individual 

pollutants and precursors. 

The MVEBs for 2031 are identical to 

the on-road mobile source emissions 

inventory provided for direct PM2.5, 

NOX and VOCs in Table 1 (in Section 

II.D.1 of this document) of this proposed 

action for that year, except that the 2031 

direct PM2.5 budget does not include 

paved road dust. As stated in that 

section, IDEQ used EPA’s MOVES2014b 

model to develop vehicle emissions 

estimates for 2031, which were 

recalculated into tons per day (from lbs 

per day) for the 2031 MVEBs. 

Based on its analysis, IDEQ set the 

mobile source emissions budgets for 

2031 provided in Table 6 of this 

proposed action, as part of the 

September 13, 2019 maintenance plan 

submission. The previously approved 

2017 MVEBs (see 85 FR 9664, February 

20, 2020), are included in Table 6. 

According to EPA’s conformity rule, the 

emissions budget acts as a ceiling on 

emissions in the year for which it is 

defined or until a SIP revision modifies 

the budget.21

TABLE 6—2017 AND 2031 MVEBS FOR THE IDAHO PORTION OF THE LOGAN UT-ID PM2.5 NAA 

Year 

Motor vehicle emissions budget 

(tpd) 

Direct PM2.5 NOX VOC 

2017 ............................................................................................................................................. .029 .544 .467 

2031 ............................................................................................................................................. .009 .149 .198 

We propose to find that Idaho has 

evaluated the appropriate pollutants 

and precursors and appropriately 

established MVEBs for direct PM2.5, 

NOX and VOCs. Idaho used the most upto-date model (MOVES2014b) available 

at the time of submission in order to 

appropriately calculate these budgets.22

The MVEBs are based on the control 

measures in the maintenance plan and 

consistent with maintaining the 2006 

24-hour PM2.5 NAAQS. Based on our 

review of Idaho’s 2031 MVEBs, we are 

proposing to approve the budgets. 

IV. Proposed Action 

EPA is proposing to redesignate the 

Idaho portion of the Logan UT-ID PM2.5

NAA, and proposing to approve the 

associated maintenance plan for the 

area. If this proposal is finalized, the 

designation status of the Idaho portion 

of the Logan, UT-ID PM2.5 NAA under 

40 CFR part 81 will be revised to 

attainment upon the effective date of 

that final action. 

V. Statutory and Executive Order 

Reviews 

Under the CAA, redesignation of an 

area to attainment and the 

accompanying approval of a 

maintenance plan under section 


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Federal Register / Vol. 86, No. 30 / Wednesday, February 17, 2021 / Proposed Rules 9893 

107(d)(3)(E) are actions that affect the 

status of a geographical area and do not 

impose any additional regulatory 

requirements on sources beyond those 

imposed by state law. A redesignation to 

attainment does not in and of itself 

create any new requirements, but rather 

results in the applicability of 

requirements contained in the CAA for 

areas that have been redesignated to 

attainment. Moreover, the Administrator 

is required to approve a SIP submission 

that complies with the provisions of the 

CAA and applicable Federal regulations. 

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 

merely approves state law as meeting 

Federal requirements and does not 

impose additional requirements beyond 

those already imposed by state law. For 

that reason, this 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); 

• Is not an Executive Order 13771 (82 

FR 9339, February 2, 2017) regulatory 

action because SIP approvals are 

exempted under Executive Order 12866; 

• 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). 

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, this rule does not have 

tribal implications as specified by 

Executive Order 13175 (65 FR 67249, 

November 9, 2000), because 

redesignation is an action that affects 

the status of a geographical area and 

does not impose any new regulatory 

requirements on tribes, impact any 

existing sources of air pollution on 

tribal lands, nor impair the maintenance 

of ozone national ambient air quality 

standards in tribal lands. 

List of Subjects 

40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Intergovernmental relations, 

Lead, Nitrogen dioxide, Ozone, 

Particulate matter, Reporting and 

recordkeeping requirements, Sulfur 

oxides, Volatile organic compounds. 

40 CFR Part 81 

Environmental protection, Air 

pollution control, National parks, 

Wilderness areas. 

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

Dated: February 9, 2021. 

Michelle L. Pirzadeh, 

Acting Regional Administrator, Region 10. 

[FR Doc. 2021–03031 Filed 2–16–21; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 281 

[EPA–R05–UST–2020–0685; FRL–10020– 

06–Region 5] 

Indiana: Final Approval of State 

Underground Storage Tank Program 

Revisions 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: Pursuant to the Resource 

Conservation and Recovery Act (RCRA 

or Act), the Environmental Protection 

Agency (EPA) proposes to take direct 

final action to approve revisions to the 

State of Indiana’s Underground Storage 

Tank (UST) program submitted by the 

State. This action is based on EPA’s 

determination that the State’s revisions 

satisfy all requirements needed for UST 

program approval. In the ‘‘Rules and 

Regulations’’ section of this Federal 

Register, EPA is approving the changes 

by direct final rule because we believe 

this action is not controversial and do 

not expect comments that oppose it. 

DATES: Send written comments by 

March 19, 2021. 

ADDRESSES: Submit your comments, 

identified by EPA–R05–UST–2020–0685 

by one of the following methods: 

1. Federal eRulemaking Portal: 

https://www.regulations.gov. Follow the 

online instructions for submitting 

comments. 

2. Email: Kamke.Sherry@epa.gov. 

Instructions: Direct your comments to 

Docket ID No. EPA–R05–UST–2020– 

0685. EPA’s policy is that all comments 

received will be included in the public 

docket without change and may be 

available online at https://

www.regulations.gov, including any 

personal information provided, unless 

the comment includes information 

claimed to be Confidential Business 

Information (CBI) or other information 

whose disclosure is restricted by statute. 

Do not submit information that you 

consider to be CBI or otherwise 

protected through https://

www.regulations.gov, or email. The 

federal https://www.regulations.gov 

website is an ‘‘anonymous access’’ 

system, which means EPA will not 

know your identity or contact 

information unless you provide it in the 

body of your comment. If you send an 

email comment directly to EPA without 

going through https://

www.regulations.gov, your email 

address will be automatically captured 

and included as part of the comment 

that is placed in the public docket and 

made available on the internet. If you 

submit an electronic comment, EPA 

recommends that you include your 

name and other contact information in 

the body of your comment and with any 

disk or CD–ROM you submit. If EPA 

cannot read your comment due to 

technical difficulties, and cannot 

contact you for clarification, EPA may 

not be able to consider your comment. 

Electronic files should avoid the use of 

special characters, any form of 

encryption, and be free of any defects or 

viruses. 

EPA encourages electronic submittals, 

but if you are unable to submit 

electronically, please reach out to EPA 

contact person listed in the notice for 

assistance with additional submission 

methods. 

You can view and copy the 

documents that form the basis for this 

action and associated publicly available 

materials through www.regulations.gov. 


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