[Federal Register Volume 86, Number 103 (Tuesday, June 1, 2021)]
[Proposed Rules]
[Pages 29222-29227]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-11441]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R03-OAR-2021-0017; FRL-10023-69-Region 3]


Air Plan Approval; Maryland; Baltimore Area Base Year Inventory 
for the 2015 Ozone National Ambient Air Quality Standards

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a state implementation plan (SIP) revision submitted by the 
State of Maryland. This revision consists of the base year inventory 
for the Baltimore, Maryland marginal nonattainment area (Baltimore 
Area) for the 2015 ozone national ambient air quality standards 
(NAAQS). This action is being taken under the Clean Air Act (CAA).

DATES: Written comments must be received on or before July 1, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R03-
OAR-2021-0017 at https://www.regulations.gov, or via email to 
David.Talley@epa.gov. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, 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, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Serena Nichols, Planning & 
Implementation Branch (3AD30), Air & Radiation Division, U.S. 
Environmental Protection Agency, Region III, 1650 Arch Street, 
Philadelphia, Pennsylvania 19103. The telephone number is (215) 814-
2053. Ms. Nichols can also be reached via electronic mail at 
Nichols.Serena@epa.gov.

SUPPLEMENTARY INFORMATION: On July 30, 2020, the Maryland Department of 
the Environment (MDE), on behalf of the State of Maryland, submitted a 
revision to the Maryland SIP entitled, ``2015 8-Hour Ozone NAAQS (0.070 
ppm) Marginal Area State Implementation Plan for the Baltimore, MD 
Nonattainment Area, SIP #20-08.'' This SIP revision, referred to in 
this rulemaking action as the ``Baltimore base year inventory SIP,'' 
addresses the base year inventory requirement for the 2015 ozone NAAQS.

I. Background

    On October 1, 2015, EPA strengthened the 8-hour ozone NAAQS, 
lowering the level of the NAAQS from 0.075 ppm parts per million (ppm) 
to 0.070 ppm. 80 FR 65292 (October 26, 2015). Effective August 3, 2018, 
EPA designated the Baltimore Area, consisting of Anne Arundel, 
Baltimore, Carroll, Harford, and Howard Counties and the City of 
Baltimore, all in Maryland, as marginal nonattainment for the 2015 
ozone NAAQS. 83 FR 25776 (June 4, 2018). CAA section 182(a)(1) requires 
ozone nonattainment areas classified as marginal or above to submit a 
comprehensive, accurate, current inventory of actual emissions from all 
emissions sources in the nonattainment area, known as a ``base year 
inventory.'' The Baltimore base year inventory SIP addresses a base 
year inventory requirement for the Baltimore Area.

II. Summary of SIP Revision and EPA Analysis

A. EPA's Evaluation of the Baltimore Base Year Inventory SIP

    EPA's review of Maryland's base year inventory SIP for the 
Baltimore Area indicates that it meets the base year inventory 
requirements for the 2015 ozone NAAQS. As required by 40 CFR 
51.1315(a), MDE selected 2017 for the base year inventory, which is 
consistent with the baseline year for the reasonable further progress 
(RFP) plan because it is the year of the most recent triennial 
inventory. MDE included actual ozone season emissions, pursuant to 40 
CFR 51.1315(c).
    EPA prepared a Technical Support Document (TSD) in support of this 
rulemaking. In that TSD, EPA reviewed the results, procedures, and

[[Page 29223]]

methodologies for the SIP base year, and found them to be acceptable 
and developed in accordance with EPA's technical guidance. The TSD is 
available online at http://www.regulations.gov, Docket ID No. EPA-R03-
OAR-2021-0017.

B. Base Year Inventory Requirements

    In EPA's December 6, 2018 (83 FR 62998) rule, ``Implementation of 
the 2015 National Ambient Air Quality Standards for Ozone: 
Nonattainment Area State Implementation Plan Requirements,'' known as 
the ``SIP Requirements Rule,'' EPA set out nonattainment area 
requirements for the 2015 ozone NAAQS. The SIP Requirements Rule 
established base year inventory requirement, which were codified at 40 
CFR 51.1315. As required by 40 CFR 51.1315(a), each 2015 ozone 
nonattainment area to submit a base year inventory within 2 years of 
designation, i.e., by no later than August 3, 2020.
    Also, 40 CFR 51.1315(a) requires that the inventory year be 
selected consistent with the baseline year for the RFP plan as required 
by 40 CFR 51.1310(b), which states that the baseline emissions 
inventory shall be the emissions inventory for the most recent calendar 
year for which a complete triennial inventory is required to be 
submitted to EPA under the provisions of subpart A of 40 CFR 51, Air 
Emissions Reporting Requirements, 40 CFR 51.1-50. The most recent 
triennial inventory year conducted for the National Emissions Inventory 
(NEI) pursuant to the Air Emissions Reporting Requirements (AERR) rule 
is 2017. 73 FR 76539 (December 17, 2008). Maryland selected 2017 as 
their baseline emissions inventory year for RFP. This selection 
comports with EPA's implementation regulations for the 2015 ozone NAAQS 
because 2017 is the inventory year. 40 CFR 51.1310(b).\1\ Further, 40 
CFR 51.1315(c) requires emissions values included in the base year 
inventory to be actual ozone season day emissions as defined by 40 CFR 
51.1300(q), which sates: Ozone season day emissions means an average 
day's emissions for a typical ozone season work weekday. The state 
shall select, subject to EPA approval, the particular month(s) in the 
ozone season and the day(s) in the work week to be represented, 
considering the conditions assumed in the development of RFP plans and/
or emissions budgets for transportation conformity.
---------------------------------------------------------------------------

    \1\ On January 29, 2021, the Court of Appeals for the D.C. 
Circuit issued its decision regarding multiple challenges to EPA's 
implementation rule for the 2015 ozone NAAQS which included, among 
other things, upholding this provision allowing states to use an 
alternative baseline year for RFP. Sierra Club v. EPA, No. 15-1465 
(D.C. Cir.) (mandate not yet issued). The other provisions of EPA's 
ozone implantation rule at issue in the case are not relevant for 
this rulemaking.
---------------------------------------------------------------------------

C. Baltimore Base Year Inventory SIP

    The Baltimore base year inventory SIP contains an explanation of 
MDE's 2017 base year emissions inventory for Baltimore (2017 Baltimore 
BYE) for stationary, non-point, non-road, and on-road anthropogenic 
sources, as well as biogenic sources, in the Baltimore Area. MDE 
estimated anthropogenic emissions for volatile organic compound (VOC), 
nitrogen oxide (NOX), and carbon monoxide (CO) for a typical 
ozone season workweek day.
    MDE developed the 2017 Baltimore BYE with the following source 
categories of anthropogenic emissions sources: Point, quasi-point, non-
point, non-road, on-road, biogenic, and commercial marine vessels, 
airport, and railroad emissions sources (MAR). Appendix A of the 
Baltimore base year inventory SIP, 2017 Base Year SIP Emissions 
Inventory Methodologies (Appendix A), sets out the methodologies MDE 
used to develop its base year inventory.\2\
---------------------------------------------------------------------------

    \2\ The Appendix A--2017 Base Year SIP Emission Inventory 
Methodologies, submitted with the 2015 8-Hour Ozone NAAQS Marginal 
Area State Implementation Plan for the Baltimore, MD Nonattainment 
Area is included in the docket for this rulemaking available online 
at https://www.regulations.gov, Docket ID: EPA-R03-OAR-2021-0017.
---------------------------------------------------------------------------

1. Point Sources
    Point sources are larger sources that are located at a fixed, 
stationary location. As defined by the AERR in 40 CFR 51.50, point 
sources are large, stationary (non-mobile), identifiable sources of 
emissions that release pollutants into the atmosphere. A point source 
is a facility that is a major source under 40 CFR part 70 for one or 
more of the pollutants for which reporting is required by 40 CFR 51.15 
(a)(1). These point sources can be associated with a single point or 
group of points in space. Examples of point source emissions categories 
include power plants, industrial boilers, petroleum refineries, cement 
plants, and other industrial plants.
    As stated in Appendix A, for the 2017 Baltimore BYE, MDE defined a 
point source located within a designated ozone nonattainment area as a 
stationary commercial or industrial facility that operations and emits 
more than 10 tons per year (tpy) of VOC; or 25 tons per year of 
NOX; or a 100 tpy of CO, sulfur oxides (SOX), 
particulate matter with an aerodynamic diameter less than 10 
micrometers (PM10), diameter less than 2.5 micrometers 
(PM2.5), and total suspended particulates (TSP).
    In Appendix A, MDE explains that it used several methods of source 
identification to ensure the point source inventory is as complete as 
possible. MDE's primary data source is its permitting program. MDE's 
compliance program identifies other point sources though facility 
inspections and investigations. In addition, facilities are required by 
Maryland's emissions statement regulations, Code of Maryland 
Regulations (COMAR) 26.11.01.05-1 and 26.11.02.19D to certify the air 
emissions for the past calendar year. The certified emissions are used 
for inventory and planning purposes.
    MDE's Air and Radiation Management Administration (ARMA) developed 
the point source data for the 2017 base year inventory. The point 
source inventory contains emissions for electric generating units (EGU) 
and Non-EGU sources in the nonattainment area (NAA). EPA guidance for 
emissions inventory development provides that ozone season day 
emissions are used for the base year inventory for the NAA. ARMA 
developed their 2017 inventory by using emissions directly reported to 
the agency by facilities as required by Maryland air quality 
regulations. These emissions are also reported to EPA, and after going 
through EPA's quality assurance (QA) and quality control (QC) process, 
are included in EPA's National Emissions Inventory (NEI). The emissions 
for this base year can be found in EPA's 2017 NEI.\3\
---------------------------------------------------------------------------

    \3\ The TSD for the Base Year Inventory Submitted with the 2015 
8-Hour Ozone NAAQS Marginal Area State Implementation Plan for the 
Baltimore, MD Nonattainment Area, included in the docket for this 
rulemaking available online at https://www.regulations.gov, Docket 
ID: EPA-R03-OAR-2021-0017.
---------------------------------------------------------------------------

2. Quasi-Point Sources
    MDE defines quasi-point sources as that are generally considered 
part of the non-point or non-road emissions sectors but are included in 
the point source emissions inventory for a particular reason. In 
Appendix A, MDE states that such reasons include Federal guidance, as 
in the case of certain airports, or to facilitate future general 
conformity determinations, as in the case of military bases, ports, and 
other similar facilities. EPA has reviewed the source categories 
included in the quasi-point sources and has found this to be a 
reasonable approach to handle these sources.

[[Page 29224]]

3. Non-Point Sources
    Non-point sources are also called ``area sources.'' These sources 
collectively represent individual sources of emissions that have not 
been inventoried as specific point or mobile sources. These individual 
sources treated collectively as non-point sources are typically too 
small, numerous, or difficult to inventory using the methods for the 
other classes of sources.
    Non-point sources that MDE evaluated for the 2017 Baltimore BYE 
include petroleum distribution losses (e.g., tank truck unloading and 
auto refueling), stationary source solvent application (e.g., dry 
cleaners, auto refinishing), bioprocess emissions sources (bakeries, 
breweries, wineries, distilleries), catastrophic/accidental releases 
(e.g., oil spills), solid waste disposal treatment, and recovery (e.g., 
open burning), small stationary source fossil fuel use (e.g., small 
utility boilers), fugitive sources (e.g., construction activity and 
unpaved roads), fire sources (e.g., agricultural burning and vehicle 
fires), and ammonia sources (e.g., agricultural livestock production 
operations). Appendix A sets out the methodologies MDE used to estimate 
emissions for each of these non-point source categories. These methods 
are consistent with the most recent EPA emission inventory guidance.
4. Non-Road Mobile Sources
    Non-road mobile sources are also called ``off-highway'' mobile 
sources. These are defined as a non-road engine or non-road vehicle. As 
per 40 CFR 51.50, a non-road engine is an internal combustion engine 
(including the fuel system) that is not used in an on-road motor 
vehicle or a vehicle used solely for competition, or that is not 
affected by sections 111 or 202 of the CAA. Also defined by 40 CFR 
51.50, a non-road vehicle (rather than engine) is a vehicle that is run 
by a non-road engine and that is not an on-road motor vehicle or a 
vehicle used solely for competition. Examples of non-road mobile 
sources include airport ground support equipment, agricultural and 
construction equipment powered by an internal combustion engine, and 
lawn and garden engines and equipment.
    As explained in Appendix A, consistent with EPA's Emission 
Inventory Guidance for Implementation of Ozone and Particulate Matter 
NAAQS and Regional Haze Regulations, MDE used the most current version 
of EPA's NONROAD2008a model, which is incorporated into EPA's Motor 
Vehicle Emission Simulator (MOVES) model, specifically MOVES2014a, to 
develop the inventory for non-road mobile sources. The NONROAD2008a 
model includes more than 80 basic and 260 specific types of non-road 
equipment and further stratifies equipment types by horsepower rating. 
Fuel types include gasoline, diesel, compressed natural gas (CNG), and 
liquefied petroleum gas (LPG).
5. Marine Vessels, Airport, Railroad Locomotives (MAR) Sources
    MAR is a non-road sub-category. MDE states in its Baltimore base 
year inventory SIP that, for MAR sources, MDE calculated emissions by 
collecting data directly from surveyed sources, or activity from state 
and federal reporting agencies. To develop the commercial marine 
vehicle emissions for the base year, Maryland used EPA's 2016 beta 
modeling platform. This platform was used because it provided the most 
recent descriptions and methodologies for calculation of marine vessel 
emissions. To estimate emissions for aircraft, Maryland used airport 
activity statistics from the Federal Aviation Administration (FAA), 
landing and takeoff cycle information from the Maryland Aviation 
Administration, and statewide survey information for landing and 
takeoffs, engine type, location, and usage data. Railroad emission 
estimates were developed using activity and fuel consumption estimates 
collected from the rail companies and proportioned to each county by 
the amount of track miles each company utilized in a county. MDE 
applied EPA emission factors using EPA guidance and methodologies or 
the best engineering method. These methods of calculating emissions are 
consistent with the most recent EPA emission inventory guidance.\4\ 
Details of the development of emissions for these sources along with 
other non-road model sources are provided in Appendix A of Maryland's 
July 30, 2020 submittal.
---------------------------------------------------------------------------

    \4\ Emission Inventory Guidance for Implementation of Ozone and 
Particulate Matter National Ambient Air Quality Standards (NAAQS) 
and Regional Haze Regulations, Page 130, included in the docket for 
this rulemaking available online at https://www.regulations.gov, 
Docket ID: EPA-R03-OAR-2021-0017 PG 130.
---------------------------------------------------------------------------

6. On-Road Mobile Sources
    On-road mobile sources are also called ``highway mobile sources.'' 
These sources are the motor vehicles (e.g., automobiles, buses, trucks) 
traveling on local and highway roads. On-road mobile sources should be 
estimated by the latest recommended on-road mobile source models. 
Currently, that means EPA's MOVES model for all states but California.
    In addition to emissions from vehicles' exhaust, the MOVES model 
estimates evaporative emissions for mobile sources, which must be 
included in the inventory. Volatile hydrocarbons evaporate from the 
fuel system while a vehicle is refueling, parked, or driving. 
Evaporative processes differ from exhaust emissions because they don't 
directly involve combustion, which is the main process driving exhaust 
emissions.
    As stated in Appendix A, MDE used EPA's MOVES2014a model to 
estimate the 2017 annual emissions as well as 2017 daily emissions from 
on-road vehicles and total energy consumption in Maryland. Emissions 
were estimated based on emission factors and vehicle activity. Emission 
factors for vehicles were based on vehicle type such as passenger cars, 
passenger trucks, vehicle age and the vehicle's operating modes. 
Operating modes for running, start, and idle emissions are included in 
MOVES. The emission factors varied over a range of conditions, such as 
the ambient air temperature, speed, traffic conditions, road types, 
road topography, etc. The generated emission factors were then 
multiplied by the appropriate vehicle miles traveled (VMT) to estimate 
emission.
    In order to estimate both the rate at which emissions are being 
generated and to calculate VMT, MDE examined its road network and fleet 
to estimate vehicle activity. For the annual inventories, this was done 
for each of the twelve months in 2017 and aggregated for the entire 
year. MDE used computer models to perform these calculations by 
simulating the travel of vehicles on the Maryland's roadway system.
    EPA has reviewed the results, procedures, and methodologies for the 
SIP base year, as well as comparing the inventory with previously QA/
QC'd data in EPA's 2017 NEI for any data discrepancies and found none. 
EPA has therefore determined the base year inventory to be acceptable 
and developed in accordance with EPA's technical guidance.
7. Biogenic Emissions
    MDE also inventoried biogenic emissions, which are not included in 
the anthropogenic total. Biogenic emissions come from natural sources, 
including vegetation, soils, volcanic emissions, lightning, and sea 
salt. They need to be accounted for in photochemical grid models, as 
most types are widespread and ubiquitous contributors to background 
formation of

[[Page 29225]]

ozone. However, they are not included in the RFP baseline.
    Biogenic emissions are typically computed using a model which 
utilizes spatial information on vegetation and land use and 
environmental conditions of temperature and solar radiation. The model 
inputs are typically horizontally allocated (gridded) data, and the 
outputs are gridded biogenic emissions which can then be speciated and 
utilized as input to photochemical grid models. In Appendix A, MDE 
explains that it used the data files created and made available by EPA. 
MDE computed biogenic emissions with a modified version of EPA's 
Biogenic Emission Inventory System (BEIS) model that utilized county 
land use data from EPA's land use inventory and temperature and cloud 
cover data from the National Weather Service. This method is acceptable 
under EPA's emission inventory guidance.\5\
---------------------------------------------------------------------------

    \5\ Emission Inventory Guidance for Implementation of Ozone and 
Particulate Matter National Ambient Air Quality Standards (NAAQS) 
and Regional Haze Regulations, Page 100, included in the docket for 
this rulemaking available online at https://www.regulations.gov, 
Docket ID: EPA-R03-OAR-2021-0017 PG 130.
---------------------------------------------------------------------------

8. Emissions Summary
    The Baltimore base year inventory SIP contains a summary of 2017 
ozone season day emissions by source category, which is presented in 
Table 1 of this document. Tables 2 through 7 of this document present 
the 2017 Baltimore BYE by source category and county. In the Baltimore 
base year inventory SIP, MDE notes that the biogenic emissions in Table 
1 are taken from EPA's NEI 2014 database. Total biogenic emissions for 
July 2014 were divided by 31 days to develop average ozone season day 
emissions for each jurisdiction in the Baltimore Area and then added 
together to develop the Baltimore Area total.

                   Table 1--2017 Baltimore BYE Summary
                       [Tons per ozone season day]
------------------------------------------------------------------------
         Source category               VOC          NOX           CO
------------------------------------------------------------------------
Point............................        5.729       47.530       18.902
Quasi-Point......................        1.310        7.274        6.549
Non-Point........................       72.233       10.931       26.954
Non-Road.........................       21.314       13.164      330.888
MAR..............................        0.930        7.440        3.848
On-Road Mobile...................       25.860       53.720      365.010
                                  --------------------------------------
    Anthropogenic Total..........      127.379      140.060      752.152
Biogenic.........................      227.640        2.740       24.550
------------------------------------------------------------------------


           Table 2--2017 Baltimore BYE Point Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............        0.885       13.079        5.523
Baltimore County.................        0.876       11.531        2.788
Carroll County...................        0.390        8.342        5.568
Harford County...................        0.471        3.110        0.422
Howard County....................        1.036        1.266        0.920
Baltimore City...................        2.070       10.202        3.682
                                  --------------------------------------
    Baltimore Area Total.........        5.729       47.530       18.900
------------------------------------------------------------------------


        Table 3--2017 Baltimore BYE Quasi-Point Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............        0.793        4.009        4.554
Baltimore County.................
Carroll County...................
Harford County...................        0.451        2.451        1.634
Howard County....................
Baltimore City...................        0.066        0.815        0.361
                                  --------------------------------------
    Baltimore Area Total.........        1.310        7.274        6.549
------------------------------------------------------------------------


         Table 4--2017 Baltimore BYE Non-Point Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............       16.532        2.090        2.836
Baltimore County.................       20.168        3.200        4.206
Carroll County...................        4.810        0.595        2.922

[[Page 29226]]

 
Harford County...................        9.111        1.007       12.685
Howard County....................        7.745        1.375        1.617
Baltimore City...................       13.867        2.665        2.689
                                  --------------------------------------
    Baltimore Area Total.........       72.233       10.931       26.954
------------------------------------------------------------------------


          Table 5--2017 Baltimore BYE Non-Road Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............        5.818        3.263       80.901
Baltimore County.................        6.421        4.725      102.577
Carroll County...................        1.572        0.980       26.043
Harford County...................        2.645        1.590       30.234
Howard County....................        2.712        1.500       53.191
Baltimore City...................        2.145        1.107       37.943
                                  --------------------------------------
    Baltimore Area Total.........       21.314       13.164      330.888
------------------------------------------------------------------------


            Table 6--2017 Baltimore BYE MAR Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............        0.113        1.623        0.776
Baltimore County.................        0.634        2.277        1.833
Carroll County...................        0.027        0.188        0.497
Harford County...................        0.031        0.469        0.321
Howard County....................        0.013        0.302        0.075
Baltimore City *.................        0.112        2.582        0.348
                                  --------------------------------------
    Baltimore Area Total.........        0.930        7.440        3.848
------------------------------------------------------------------------
* Emissions from marine vessels at the Port of Baltimore are included
  here.


           Table 7--2017 Baltimore BYE Mobile Source Emissions
                       [Tons per ozone season day]
------------------------------------------------------------------------
           County name                 VOC          NOX           CO
------------------------------------------------------------------------
Anne Arundel County..............         6.17        12.33        85.88
Baltimore County.................         8.12        17.72       117.58
Carroll County...................         2.13         3.10        21.86
Harford County...................         2.73         5.26        35.31
Howard County....................         3.12         8.21        54.20
Baltimore City...................         3.60         7.10        50.18
                                  --------------------------------------
    Baltimore Area Total.........        25.86        53.72       365.01
------------------------------------------------------------------------

III. Proposed Action

    EPA's review of this material indicates the Baltimore base year 
inventory SIP meets the base year inventory requirement for the 2015 
ozone NAAQS for the Baltimore Area. Therefore, EPA is proposing to 
approve the Baltimore base year inventory SIP, which was submitted on 
July 30, 2020. EPA is soliciting public comments on the issues 
discussed in this document. These comments will be considered 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 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 imposed by state 
law. For that reason, this proposed action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a

[[Page 29227]]

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, this proposed rulemaking, proposing to approve 
Maryland's base year inventory SIP for the 2015 ozone NAAQS, does not 
have tribal implications as specified by Executive Order 13175 (65 FR 
67249, November 9, 2000), because the SIP is not approved to apply in 
Indian country located in the State, and EPA notes that it will not 
impose substantial direct costs on tribal governments or preempt tribal 
law.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Ozone, 
Reporting and recordkeeping requirements, Nitrogen dioxide, Volatile 
organic compounds.

    Dated: May 19, 2021.
Diana Esher,
Acting Regional Administrator, Region III.
[FR Doc. 2021-11441 Filed 5-28-21; 8:45 am]
BILLING CODE 6560-50-P


