[Federal Register Volume 86, Number 61 (Thursday, April 1, 2021)]
[Proposed Rules]
[Pages 17106-17109]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-06754]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2020-0646; FRL-10021-65-Region 8]


Approval and Promulgation of Implementation Plans; Utah; 2017 
Base Year Inventories for the 2015 8-Hour Ozone National Ambient Air 
Quality Standard for the Uinta Basin, Northern Wasatch Front and 
Southern Wasatch Front Nonattainment Areas

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a state implementation plan (SIP) revision submitted by the 
State of Utah. The revision fulfills the base year inventory 
requirement for the 2015 8-hour ozone national ambient air quality 
standard (NAAQS) for the Uinta Basin, Northern Wasatch Front, and 
Southern Wasatch Front nonattainment areas. Utah submitted the base 
year emissions inventories to meet, in part, the nonattainment 
requirements for Marginal ozone nonattainment areas under the 2015 8-
hour ozone NAAQS. EPA is taking this action pursuant to sections 110, 
172, and 182 of the Clean Air Act (CAA).

DATES: Written comments must be received on or before May 3, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2020-0646, to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
www.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.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available electronically in 
www.regulations.gov. To reduce the risk of COVID-19 transmission, for 
this action we do not

[[Page 17107]]

plan to offer hard copy review of the docket. Please email or call the 
person listed in the FOR FURTHER INFORMATION CONTACT section if you 
need to make alternative arrangements for access to the docket.

FOR FURTHER INFORMATION CONTACT: Matthew Lang, Air and Radiation 
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, 
Colorado 80202-1129, (303) 312-6709, [email protected].

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

I. Background

    Ground-level ozone is formed when nitrogen oxides (NOX) 
and volatile organic compounds (VOCs) react in the presence of 
sunlight. Referred to as ozone precursors, these two pollutants are 
emitted by many types of pollution sources, including motor vehicles, 
power plants, industrial facilities, and area wide sources, such as 
consumer products and lawn and garden equipment. Scientific evidence 
indicates that adverse public health effects may occur following 
exposure to ozone pollution. These effects are more pronounced in 
children and adults with lung disease. Breathing air containing ozone 
can reduce lung function and inflame airways, which can increase 
respiratory symptoms and aggravate asthma or other lung diseases. In 
1979, in response to this scientific evidence, EPA promulgated the 
first ozone NAAQS, the 0.12 part per million (ppm) 1-hour ozone 
NAAQS.\1\ EPA had previously promulgated a NAAQS for total 
photochemical oxidants.
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    \1\ Revisions to the National Ambient Air Quality Standards for 
Photochemical Oxidants, 44 FR 8202 (Feb. 8, 1979).
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    On July 18, 1997, EPA promulgated a revised ozone NAAQS of 0.08 
ppm, averaged over eight hours.\2\ EPA determined this standard to be 
more protective of public health than the previous 1979 1-hour ozone 
standard. In 2008, EPA revised the 8-hour ozone NAAQS from 0.08 to 
0.075 ppm.\3\ On October 26, 2015, EPA again strengthened the 8-hour 
ozone NAAQS to 0.070 ppm, based on extensive scientific evidence about 
ozone's effects on public health and welfare.\4\ Effective August 3, 
2018, EPA designated the Uinta Basin, Northern Wasatch Front, and 
Southern Wasatch Front areas as Marginal nonattainment for the more 
stringent 2015 8-hour ozone NAAQS.\5\
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    \2\ National Ambient Air Quality Standards for Ozone, 62 FR 
38856.
    \3\ National Ambient Air Quality Standards for Ozone, 73 FR 
16436 (March 27, 2008).
    \4\ National Ambient Air Quality Standards for Ozone, 80 FR 
65292.
    \5\ Additional Air Quality Designations for the 2015 Ozone 
National Ambient Air Quality Standards, 83 FR 25776 (June 4, 2018).
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    The Uinta Basin Nonattainment Area (NAA) is comprised of portions 
of Duchesne and Uintah Counties. The Northern Wasatch Front NAA 
includes Salt Lake, Davis, and portions of Weber and Tooele Counties. 
The Southern Wasatch Front NAA is comprised of only a portion of Utah 
County.
    Under section 172(c)(3) of the CAA, Utah is required to submit 
comprehensive, accurate, and current inventories of actual emissions 
from all sources of the relevant pollutants in its Marginal 
nonattainment areas, i.e., the Uinta Basin NAA, Northern Wasatch Front 
NAA, and Southern Wasatch Front NAA.\6\ Specific to areas classified as 
Marginal ozone nonattainment, CAA section 182(a)(1) requires that a 
base year inventory of ozone precursors be submitted within two years 
of the nonattainment designation.\7\
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    \6\ 42 U.S.C. 7502(c)(3).
    \7\ Id. 7511a(a)(1).
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    EPA's guidance for emissions inventory development specifically 
calls for states to report ``ozone season day emissions'' in the base 
year inventory.\8\ EPA's regulations define ozone season day emissions 
as an average day's emissions for a typical ozone season work 
weekday.\9\ Although elevated ground-level ozone is typically a 
summertime issue for many areas, high ground-level ozone can occur 
during the winter with the presence of temperature inversions and snow 
cover as well as sufficient solar radiation and ozone precursors.
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    \8\ EPA, Emissions Inventory Guidance for Implementation of 
Ozone and Particulate Matter National Ambient Air Quality Standards 
(NAAQS) and Regional Haze Regulations, May 2017, 21, 45, 75.
    \9\ 40 CFR 51.1300(q).
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    CAA sections 172 and 182 identify additional plan submissions and 
requirements for ozone nonattainment areas. Under sections 172(c)(5) 
and 182(a)(3)(B) of the CAA, Utah is required to implement a 
nonattainment new source review permit program and emission statement 
requirement, respectively.\10\ EPA will act on SIP revisions that 
address these two requirements separately from the base year emissions 
inventories at issue in this action.
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    \10\ 42 U.S.C. 7502(c)(5); 7511a(a)(3)(B).
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II. Summary of SIP Revision

    On July 30, 2020, the Utah Division of Air Quality (UDAQ) submitted 
a SIP revision titled ``2017 Marginal Ozone Inventories'' to satisfy 
the emission inventory requirements under CAA sections 172(c)(3) and 
182(a)(1).\11\ On January 28, 2021, UDAQ submitted a superseding 
supplement to the earlier submission, which corrected and explained 
administrative errors in Utah's SIP revision.\12\ Utah met the 
reasonable notice and public hearing requirements of CAA section 110(a) 
for the SIP revision through reasonable notice posted on June 11, 2020, 
and notice of a public hearing for July 16, 2020.\13\
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    \11\ Letter dated July 29, 2020, from Gary R. Herbert, Governor, 
State of Utah, to Gregory Sopkin, Regional Administrator, EPA, 
Region 8.
    \12\ Utah, Utah Administrative Documentation, Marginal Ozone 
Inventory Supplement, January 2021 (``UT SIP Revision'').
    \13\ Id. at 68, 86-87, 107-108.
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    Utah's SIP revision uses 2017 as its base year for SIP planning 
purposes, as recommended in EPA's implementation rule for the 2015 
Ozone NAAQS.\14\ The 2017 base year inventories represent 
NOX and VOC emissions estimates for an average episode day 
(work weekday) during the peak ozone season of an area. For the Uinta 
Basin NAA, an average episode day during the peak ozone season is in 
February. For the Northern Wasatch Front NAA and Southern Wasatch Front 
NAA, an average episode day during the peak ozone season is in 
July.\15\ The inventories were developed for all major source 
categories including point sources, area (nonpoint) sources, and mobile 
sources, including both nonroad mobile and on-road mobile sources.\16\ 
Additionally, the Uinta Basin NAA inventory included a separate oil and 
gas source category.\17\ Emissions sources in the Uinta Basin are 
located both in state land and in Indian country. We note that the 
Uinta Basin portion of Utah's SIP revision includes only emissions from 
sources located on state lands within the Uinta Basin NAA.\18\
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    \14\ Implementation of the 2015 National Ambient Air Quality 
Standards for Ozone: Nonattainment Area State Implementation Plan 
Requirements, 83 FR 62998, 63004-05, 63011 n.29 (December 6, 2018).
    \15\ UT SIP Revision at 92, 98, 103.
    \16\ Id. at 93, 99, 104.
    \17\ Note that Utah included oil and gas emissions as area 
sources for the Northern and Southern Wasatch NAAs. See, e.g., UDAQ, 
Area Source Inventories, April 2, 2020.
    \18\ UT SIP Revision at 95. See also 40 CFR 51.1, 51.15(b).
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    Tables 1-3 of this document summarize the 2017 VOC and 
NOX emission inventory by source sector for the Uinta Basin 
NAA, Northern Wasatch Front NAA, and Southern Wasatch Front NAA. Ozone 
season weekday emissions are given in tons per day (tpd).

[[Page 17108]]



    Table 1--Uinta Basin Nonattainment Area 2017 VOC and NOX Baseline
                           Emissions Inventory
                             [Tons/Day] \19\
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                  Source type                       NOX          VOC
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Point.........................................         1.07         0.73
Nonpoint......................................         0.22         1.46
On-road Mobile................................         3.24         1.22
Nonroad Mobile................................          0.1         0.11
Oil & Gas.....................................        10.61         37.4
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    Total.....................................        15.24        40.93
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   Table 2--Northern Wasatch Front Nonattainment Area 2017 VOC and NOX
                      Baseline Emissions Inventory
                             [Tons/Day] \20\
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                  Source type                       NOX          VOC
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Point.........................................        18.83         5.88
Nonpoint......................................         1.25        44.48
On-road Mobile................................        52.46        28.56
Nonroad Mobile................................        27.59        18.54
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    Total.....................................       100.12        97.46
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   Table 3--Southern Wasatch Front Nonattainment Area 2017 VOC and NOX
                      Baseline Emissions Inventory
                             [Tons/Day] \21\
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                  Source type                       NOX          VOC
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Point.........................................         1.25         0.21
Nonpoint......................................         0.56         13.1
On-road Mobile................................        14.93         7.07
Nonroad Mobile................................         5.18         3.67
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    Total.....................................        21.92        24.06
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    Point sources are large, stationary, identifiable sources of 
emissions that release pollutants into the atmosphere. For Utah's 2017 
base year inventories, the State determined point source emissions in 
the three nonattainment areas from source-reported data in the UDAQ 
State and Local Emissions Inventory System (SLEIS) database, which 
includes any source that has the potential to emit greater than or 
equal to 100 tons per year of NOX or VOCs. The point source 
actuals are reported in tons per year.\22\ Utah's SIP revision uses the 
emissions processing software SMOKE (Sparse Matrix Operator Kernel 
Emissions) to distribute inventoried pollutants in time and space, 
including to a 24-hour period.\23\ The SMOKE Emissions Processing 
technical support document included with Utah's SIP revision describes 
the processing software in greater detail.\24\ A further description of 
the point source emissions inventory is found in the Base Year Ozone 
SIP Point Source Inventory technical support document included with 
Utah's SIP revision.\25\
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    \19\ Id. at 95; Note that the Uinta Basin inventory represents 
only emissions from State land in the Uinta Basin NAA.
    \20\ Id. at 100.
    \21\ Id. at 105.
    \22\ See, e.g., id. at 95.
    \23\ Id. at 94, 100, 105.
    \24\ UDAQ, SMOKE Emissions Processing, June 10, 2020.
    \25\ Utah, Base Year Ozone SIP Point Source Inventory (listing 
point sources by NAA).
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    Nonpoint sources, also known as area sources, are sources of 
pollution that are small and numerous, and that have not been 
inventoried as specific point or mobile sources. They include a wide 
range of sources including, for example, dry cleaners, residential 
heating and cooling, auto body painting, and consumer solvents. To 
inventory nonpoint sources, sources are grouped so that emissions can 
be estimated collectively using one methodology. For Utah's 2017 base 
year emissions inventories, the State determined area emissions from 
UDAQ's area source emissions calculation workbooks that are the 
foundation for data in the 2017 National Emissions Inventory (NEI).\26\
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    \26\ UT SIP Revision at 93, 99, 104.
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    The on-road mobile source portion of the State's 2017 base year 
inventories includes emissions from vehicles, such as cars, trucks, 
trash trucks, over-the-road diesel trucks, and buses, which are 
operated on public roadways. These emissions were estimated using EPA's 
Motor Vehicle Emissions Simulator (MOVES) model version MOVES2014b. 
Metropolitan planning organizations (MPOs) determined on-road emissions 
for the urban nonattainment areas. The Utah Department of 
Transportation (UDOT) determined on-road emissions for rural 
nonattainment counties and UDAQ determined emissions in rural counties 
in attainment. The on-road mobile source portion of the inventories for 
the Uinta Basin NAA, Northern Wasatch Front NAA, and Southern Wasatch 
Area were developed by UDOT, the Wasatch Front Regional Council (WFRC) 
MPO and the Mountainland Association of Governments (MAG) MPO, 
respectively.\27\
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    \27\ Id. at 94, 100, 105.
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    The On-road Mobile Sources technical support document \28\ included 
with the State's submittal details MOVES modeling inputs including 
speeds, vehicle fuel properties and specifications, Vehicle Miles 
Traveled (VMT), inspection and maintenance profiles, VMT mix, vehicle 
age distributions, and meteorological conditions.\29\ VMT within the 
NAAs is based on their respective transportation model's output data 
from the UDOT, MAG, and WFRC.\30\ The MOVES modeling used 
meteorological inputs for the Uinta Basin NAA based on conditions for 
an ozone exceedance event from February 1-10, 2013, in Uintah, Utah, 
and conditions on an average July day in 2017 for both the Southern 
Wasatch Front NAA and Northern Wasatch Front NAA. UDOT, MAG, and WFRC 
developed the on-road inventories in the State's submittal using MOVES 
2014b default fuel parameters for diesel and compressed natural gas. 
The inventories adjusted gasoline fuel parameters for gasoline sulfur 
levels in Utah since small volume refiners were not required to comply 
with federal Tier 3 gasoline (10 ppm sulfur) requirements until January 
1, 2020. Utah notes in the technical support document for on-road 
mobile sources that the EPA Office of Transportation and Air Quality 
(OTAQ) provided the 2017 local gasoline sulfur value of 20.9 ppm.\31\
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    \28\ Utah provided a separate technical support document for 
each source sector in each of the three NAAs. Each technical support 
document contains largely the same material regarding methodology. 
Thus, for ease of reference, we will cite to the technical support 
document for the Northern Wasatch Front NAA unless otherwise 
specified. Please see the docket for specific technical support 
documents.
    \29\ See, e.g., UDAQ, Technical Support Document for On-road 
Mobile Sources: Summertime 2017 Baseline Ozone Emissions Inventory 
for the Northern Wasatch Front, UT Nonattainment Area and 
Surrounding Modeling Domain in Utah, April 2020, 5.
    \30\ Id. at 6-7.
    \31\ Id. at 8.
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    Nonroad mobile sources are mobile sources other than on-road 
vehicles, including aircraft, locomotives, construction and 
agricultural equipment, recreational equipment like snowmobiles, and 
marine vessels. The 2017 base year inventory includes emissions from 
nonroad mobile sources, excluding aircraft and locomotives, as 
estimated for the Uinta Basin NAA, Northern Wasatch Front NAA, and 
Southern Wasatch Front NAA by EPA's Non-Road Model. EPA's Non-Road 
Model is incorporated into EPA's MOVES model.\32\
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    \32\ Utah SIP Revision at 94, 100, 105.
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    The State prepared aircraft emissions from data reported by the 
2017 NEI, and determined emissions from airport ground support 
equipment using the Federal Aviation Administration's Aviation 
Environmental Design Tool.\33\

[[Page 17109]]

For rail yard emissions, associated with the operation of switcher 
engines, Utah used emissions reported by the 2017 NEI that are compiled 
by the Eastern Regional Technical Advisory Committee. Commuter rail 
emissions from UTA FrontRunner are also included.\34\ The State 
processed the nonroad emissions for the inventories included in the 
State's submittal with SMOKE. Additional information describing the 
development of the inventory of the nonroad mobile source sector can be 
found in the Non-Road Mobile Source technical support document included 
with the State's submittal.
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    \33\ UDAQ, Technical Support Document Non-Road Mobile Source: 
Ozone Inventory for 2017 Base Year, February and July, April 2020, 
3, 5.
    \34\ Id. at page 8.
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    To inventory oil and gas emissions, Utah explains in the SIP 
revision that emissions within the Uinta Basin NAA were determined from 
workbooks submitted by sources as well as EPA/NOMAD (Nonpoint Methods 
Advisory group) oil and gas tool outputs.\35\ Additionally, the State 
included emissions associated with off-road mobile oil and gas and 
nonroad oil and gas well pad construction equipment in the 2017 base 
year inventory for the Uinta Basin NAA. Off-road mobile oil and gas 
emissions are from mobile sources that operate within the oil and gas 
fields located in the Uinta Basin NAA and were calculated in the base 
year inventory from emission factors generated using MOVES2014b.\36\ 
Nonroad oil and gas well equipment emissions, which include emissions 
from well pad, access road, and pipeline construction, were calculated 
from emissions factors generated by the EPA MOVES2014b Non-Road 
Model.\37\ Well counts for 2017 were provided for by the UDAQ Technical 
Analysis Section from the Utah Division of Oil, Gas, and Mining for 
both the determination of oil and gas off-road mobile and nonroad 
emissions.\38\
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    \35\ Utah SIP Revision at 94.
    \36\ UDAQ, Technical Support Document 2017 Baseline Wintertime 
Ozone Emissions Inventory: Off-road Mobile Sources Operating Within 
the Oil and Gas Fields Located in the Uintah, UT Nonattainment Area, 
March 2020, 5-6.
    \37\ UDAQ, Technical Support Document 2017 Baseline Wintertime 
Ozone Emissions Inventory: Non-Road Well Pad Construction Equipment 
Operating within the Oil and Gas Fields within the Uintah, UT 
Nonattainment Area, March 2020, 4.
    \38\ Id. at 5; UDAQ, Technical Support Document 2017 Baseline 
Wintertime Ozone Emissions Inventory: Off-road Mobile Sources 
Operating Within the Oil and Gas Fields Located in the Uintah, UT 
Nonattainment Area, March 2020, 9.
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    EPA has reviewed Utah's 2017 base year emission inventories' 
results, procedures, and methodologies for the Uinta Basin NAA, 
Northern Wasatch Front NAA, and Southern Wasatch Front NAA and we 
propose to find them approvable. EPA has concluded that the 2017 base 
year inventories are based on the most current and accurate information 
available to the State at the time the inventories were developed. 
Additionally, the 2017 inventory comprehensively addresses all source 
categories in Utah's NAAs and was developed consistent with the 
relevant EPA emission inventory guidance and models.

III. Proposed Action

    As detailed in the Utah SIP Revision and summarized previously in 
this proposed rulemaking, the procedures used by the State in 
developing the 2017 base year inventories for the source sectors in the 
Uinta Basin NAA, Northern Wasatch Front NAA, and Southern Wasatch Front 
NAA satisfy the requirements of the CAA. Therefore, we are proposing to 
approve the 2017 base year inventories for the 2015 8-hour ozone NAAQS 
for the Uinta Basin, Northern Wasatch Front, and Southern Wasatch Front 
Marginal NAAs because the State prepared the inventories in accordance 
with the requirements in sections 172(c)(3) and 182(a)(1) of the CAA 
and its implementing regulations, including those at 40 CFR 51.1315. 
EPA is soliciting public comments on the issues discussed in this 
document. EPA will consider these comments before taking final action.

IV. 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. 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 requirements of the CAA. Accordingly, 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 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, the proposed rule does not have tribal implications and will 
not impose substantial direct costs on tribal governments or preempt 
tribal law as specified by Executive Order 13175 (65 FR 67249, November 
9, 2000).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Greenhouse gases, Incorporation by reference, Intergovernmental 
relations, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting 
and recordkeeping requirements, Sulfur oxides, Volatile organic 
compounds.

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

    Dated: March 23, 2021.
Debra H. Thomas,
Acting Regional Administrator, Region 8.
[FR Doc. 2021-06754 Filed 3-31-21; 8:45 am]
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