[Federal Register Volume 86, Number 190 (Tuesday, October 5, 2021)]
[Proposed Rules]
[Pages 54887-54894]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-21738]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2021-0408; FRL-8902-01-R9]


Clean Air Plans; Base Year Emissions Inventories for the 2015 
Ozone Standards; California

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve revisions to the California State Implementation Plan (SIP) 
concerning the base year emissions inventories for 18 areas designated 
as nonattainment areas (NAAs) for the 2015 ozone National Ambient Air 
Quality Standards (2015 ozone NAAQS) submitted on July 24, 2020. The 
areas include: Amador County, Butte County, Calaveras County, Imperial 
County, Kern County (Eastern Kern), Los Angeles--San Bernardino 
Counties (West Mojave Desert), Los Angeles--South Coast Air Basin, 
Mariposa County, Nevada County (Western part), Riverside County 
(Coachella Valley), Sacramento Metro, San Francisco Bay Area, San 
Joaquin Valley, San Luis Obispo (Eastern part), Sutter Buttes, Tuolumne 
County, Tuscan Buttes, and Ventura County. We are proposing to approve 
these revisions under the Clean Air Act (CAA or ``the Act''), which 
establishes emissions inventory requirements for all ozone 
nonattainment areas.

DATES: Written comments must arrive on or before November 4, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2021-0408 at https://www.regulations.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. The EPA may publish any comment received to its public 
docket. Do not submit electronically any information you consider to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Multimedia submissions (audio, 
video, etc.) must be accompanied by a written comment. The written 
comment is considered the official comment and should include 
discussion of all points you wish to make. The EPA will generally not 
consider comments or comment contents located outside of the primary 
submission (i.e., on the web, cloud, or other file sharing system). For 
additional submission methods, please contact the person identified in 
the FOR FURTHER INFORMATION CONTACT section. For the full EPA public 
comment policy, information about CBI or multimedia submissions, and 
general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets. If you need assistance in a 
language other than English or if you are a person with disabilities 
who needs a reasonable accommodation at no cost to you, please contact 
the person identified in the FOR FURTHER INFORMATION CONTACT section.

[[Page 54888]]


FOR FURTHER INFORMATION CONTACT: Khoi Nguyen, Air Planning Office (AIR-
2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105, (415) 
947-4120, or by email at nguyen.khoi@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,'' 
and ``our'' refer to the EPA.

Table of Contents

I. Background
II. Summary and Analysis of the State's Submittal
    A. Statutory and Regulatory Requirements
    1. Procedural Requirements for Adoption and Submittal of SIP 
Revisions
    2. Requirements for Base Year Inventories
    B. Summary of the State's Submittal
    1. Stationary Point Source Emissions
    2. Area-wide Source Emissions
    3. Off-Road Mobile Source Emissions
    4. On-Road Mobile Source Emissions
    C. The EPA's Evaluation of the State's Submittal
    1. Evaluation of Procedural Requirements
    2. Evaluation of Base Year Inventory Requirements
III. Proposed Action
IV. Statutory and Executive Order Reviews

I. Background

    On October 26, 2015, the EPA promulgated a revised 8-hour ozone 
NAAQS of 0.070 parts per million (ppm).\1\ In accordance with section 
107(d) of the CAA, the EPA must designate an area ``nonattainment'' if 
it is violating the NAAQS or if it is contributing to a violation of 
the NAAQS in a nearby area.
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    \1\ 80 FR 65292 (October 26, 2015).
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    The EPA designated 21 areas in California as nonattainment for the 
2015 ozone NAAQS on June 4, 2018, effective August 3, 2018.\2\ Amador 
County, Calaveras County, Butte County, Imperial County, Mariposa 
County, San Francisco Bay Area, San Luis Obispo (Eastern part), Sutter 
Buttes, Tuolumne County, and Tuscan Buttes NAAs were classified as 
Marginal nonattainment. Kern County (Eastern Kern), Nevada County 
(Western part), Sacramento Metro, and San Diego County NAAs were 
classified as Moderate nonattainment. The EPA classified the Ventura 
County NAA as Serious nonattainment. The EPA classified the Los 
Angeles-San Bernardino Counties (West Mojave Desert) and Riverside 
County (Coachella Valley) NAAs as Severe-15 nonattainment. The EPA 
classified the Los Angeles-South Coast Air Basin and San Joaquin Valley 
NAAs as Extreme nonattainment. The EPA designated the lands of the 
Pechanga Band of Luise[ntilde]o Mission Indians of the Pechanga 
Reservation and the Morongo Band of Mission Indians as separate NAAs 
and classified them as Marginal and Serious nonattainment, 
respectively. The State of California does not have regulatory 
authority on any Indian reservation land or in any other area where the 
EPA or an Indian tribe has demonstrated that a tribe has jurisdiction.
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    \2\ 83 FR 25776 (June 4, 2018).
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    The EPA finalized the 2015 ozone NAAQS SIP Requirements Rule (SRR) 
on December 6, 2018.\3\ The SRR established implementation requirements 
for the 2015 ozone NAAQS, including requirements for ``base year'' 
emissions inventories under CAA section 182(a)(1). The 2015 Ozone SRR 
is codified at 40 CFR part 51, subpart CC, and the emissions inventory 
requirements are codified at 40 CFR 51.1315.
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    \3\ ``Implementation of the 2015 National Ambient Air Quality 
Standards for Ozone: Nonattainment Area State Implementation Plan 
Requirements,'' Final Rule, 83 FR 62998 (December 6, 2018).
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    Within two years of designations, Section 182(a)(1) of the CAA and 
40 CFR 51.1315 require states and local governments to prepare base 
year emissions inventories for all areas exceeding the ozone standards. 
On July 27, 2020, the California Air Resources Board (CARB) submitted 
the ``70 ppb Ozone SIP Submittal'' (``2020 CARB SIP Submittal'') to the 
EPA.\4\ The 2020 CARB SIP Submittal contains a staff report with a 
release date of May 22, 2020, and attachments of emissions inventories 
that address base year inventory requirements for 18 of the 21 NAAs in 
California.\5\ In this action, we are evaluating and proposing action 
on the 2020 CARB SIP Submittal.\6\
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    \4\ Letter dated July 24, 2020, from Richard W. Corey, Executive 
Officer, CARB, to John Busterud, Regional Administrator, EPA Region 
IX (submitted electronically July 27, 2020).
    \5\ CARB's submittal does not include the San Diego NAA, which 
was submitted separately via the State Planning Electronic 
Collaboration System (SPeCS) for SIPs on January 12, 2021. The EPA 
will take action on the emissions inventory for the San Diego NAA in 
a separate rulemaking. Because the State of California does not have 
regulatory authority over the Pechanga and Morongo NAAs, CARB's 
submittal does not include emissions inventories for these areas.
    \6\ The 2020 CARB SIP Submittal, Section III addresses Vehicle 
Miles Travel (VMT) offsets for the South Coast Air Basin, San 
Joaquin Valley, and Coachella Valley. The EPA will take action on 
VMT offsets in a separate rulemaking.
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II. Summary and Analysis of the State's Submittal

A. Statutory and Regulatory Requirements

1. Procedural Requirements for Adoption and Submittal of SIP Revisions
    CAA sections 110(a)(1) and 110(l) and 40 CFR 51.102 require states 
to provide reasonable notice and an opportunity for a public hearing 
prior to adoption of SIP revisions. Section 110(k)(1)(B) requires the 
EPA to determine whether a SIP submittal is complete within 60 days of 
receipt. Any plan that the EPA does not affirmatively determine to be 
complete or incomplete will become complete six months after the day of 
submittal by operation of law. A finding of completeness does not 
approve the submittal as part of the SIP, nor does it indicate that the 
submittal is approvable. It does start a 12-month clock for the EPA to 
act on the SIP submittal (see CAA section 110(k)(2)).
2. Requirements for Base Year Inventories
    CAA section 182(a)(1) and 40 CFR 51.1315 require states to develop 
and submit, as a SIP revision, emissions inventories for all areas 
designated as nonattainment for any NAAQS. An emissions inventory for 
ozone is an estimation of actual emissions of air pollutants that 
contribute to the formation of ozone in an area. Ozone is a gas that is 
formed by the reaction of volatile organic compounds (VOC) and oxides 
of nitrogen (NOX) in the atmosphere in the presence of 
sunlight (VOC and NOX are referred to as ozone precursors). 
Therefore, an emissions inventory for ozone focuses on the emissions of 
VOC and NOX. VOC is emitted by many types of sources, 
including power plants, industrial sources, on-road and off-road mobile 
sources, smaller stationary sources collectively referred to as area 
sources, and biogenic sources. NOX is primarily emitted by 
combustion sources, both stationary and mobile.
    Emissions inventories provide emissions data for a variety of air 
quality planning tasks, including establishing baseline emissions 
levels (i.e., the level of anthropogenic emissions associated with 
violations of the ozone standard), calculating emissions reduction 
targets needed to attain the NAAQS and to achieve reasonable further 
progress (RFP) toward attainment of the ozone standard, determining 
emissions inputs for ozone air quality modeling analyses, and tracking 
emissions over time to

[[Page 54889]]

determine progress toward achieving air quality and emissions reduction 
goals. For the 2015 ozone NAAQS, states should submit ozone season day 
\7\ emissions estimates for an inventory calendar year to be consistent 
with the baseline year for the RFP plan as required by 40 CFR 
51.1310(b). For the RFP baseline year for the 2015 ozone NAAQS states 
may use a calendar year for the most recently available complete 
triennial (3-year cycle) emissions inventory (40 CFR 51, subpart A) 
preceding the year of the area's effective date of designation as a 
nonattainment area.\8\ States are required to submit estimates of VOC 
and NOX emissions for four general classes of anthropogenic 
sources: Stationary point sources; area sources; on-road mobile 
sources; and off-road mobile sources.
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    \7\ See 40 CFR 51.1300(q). Also see ``Emissions Inventory 
Guidance for Implementation of Ozone and Particulate Matter National 
Ambient Air Quality Standards (NAAQS) and Regional Haze 
Regulations,'' EPA-454/B-17-002, EPA, May 2017. The selected ozone 
season should be representative of the conditions leading to 
nonattainment.
    \8\ 83 FR 63034-63035 (December 6, 2018). The RFP requirements 
specified in CAA section 182(b)(1) apply to all areas designated 
nonattainment for ozone classified Moderate or higher.
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B. Summary of the State's Submittal

    The 2020 CARB SIP Submittal documents the public review process 
followed prior to its submittal to the EPA as a revision to the SIP. 
The submittal includes a copy of a CARB notice of public meeting on 
June 25, 2020 to consider the approval of the submittal,\9\ a 
transcript from the June 25, 2020 meeting,\10\ a signed resolution 
stating that CARB made the emissions inventories available for public 
review at least 30 days prior to the board hearing and that the 
emissions inventories were adopted after notice and public hearing,\11\ 
and a compilation of comments received by CARB prior to and during the 
June 25, 2020 public meeting.\12\
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    \9\ Notice of Public Meeting to Consider 70 Parts Per Billion 
Ozone State Implementation Plan Submittal, California Air Resources 
Board, May 22, 2020.
    \10\ Videoconference Meeting, State of California, Air Resources 
Board, CAL/EPA Headquarters, Byron Sher Auditorium, Second Floor, 
1001 I Street, Sacramento, California 95814, Thursday, June 25, 
2020, 9:03 a.m., James F. Peters, CSR, Certified Shorthand Reporter, 
License Number 10063.
    \11\ CARB, ``70 Parts Per Billion Ozone State Implementation 
Plan Submittal,'' Resolution 20-17, June 25, 2020, Agenda Item No.: 
20-6-1, signed by Ryan Sakazaki, Board Clerk.
    \12\ Compilation of comments received for 70 Parts Per Billion 
Ozone State Implementation Plan Submittal. CARB indicated in its 
July 24, 2020 transmittal letter to the EPA that CARB has considered 
all comments and has determined all are non-substantive and do not 
pertain to the action.
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    CARB selected 2017 as the base year because it was the most recent 
calendar year for which a complete triennial inventory was required to 
be submitted to the EPA, and because the year is consistent with the 
baseline year for the reasonable further progress (RFP) plan.\13\ The 
submitted base year emissions inventories are expressed as 2017 average 
ozone season day emissions in tons per day (tpd) \14\ and categorized 
as stationary point sources, area-wide sources, on-road mobile sources, 
and off-road mobile sources. The 2020 CARB SIP Submittal describes 
methods used to estimate emissions for each category and 
subcategory.\15\ The 2020 CARB SIP Submittal also describes how 
emissions were calculated for ``split regions'' not defined by CARB's 
county, air basin, and district boundaries,\16\ and CARB's quality 
assurance and quality control process.\17\
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    \13\ 2020 CARB SIP Submittal, page 9.
    \14\ 2020 CARB SIP Submittal, pages 5 and 9. The submittal 
indicates that statewide attainment challenges for the 8-hour ozone 
standard occur in the summer months, defined as May-October, and 
that seasonal inventories account for temporal activity variations 
throughout the year, as determined by category-specific temporal 
profiles.
    \15\ 2020 CARB SIP Submittal, pages 10-33.
    \16\ 2020 CARB SIP Submittal, page 9.
    \17\ 2020 CARB SIP Submittal, pages 9-10.
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    Table 1 summarizes the 2017 emissions inventories in tons of 
emissions per ozone season day for the Amador County, Butte County, 
Calaveras County, Imperial County, Kern County (Eastern Kern), Los 
Angeles--San Bernardino Counties (West Mojave Desert), Los Angeles--
South Coast Air Basin, Mariposa County, Nevada County (Western part), 
Riverside County (Coachella Valley), Sacramento Metro, San Francisco 
Bay Area, San Joaquin Valley, San Luis Obispo (Eastern part), Tuolumne 
County, and Ventura County NAAs for NOX and VOC \18\ 
emissions.\19\ The 2020 CARB SIP Submittal indicated that the Sutter 
Buttes and Tuscan Buttes NAAs are both small, high elevation areas and 
contained no anthropogenic sources; therefore there are no associated 
emissions inventories with these two NAAs.\20\
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    \18\ The State of California refers to reactive organic gases 
(ROG) rather than VOC in some of its ozone-related SIP submissions. 
As a practical matter, ROG and VOC refer to the same set of chemical 
constituents, and for simplicity, we refer to this set of gases as 
VOC in this proposed rule.
    \19\ 2020 CARB SIP Submittal, pages 7-35.
    \20\ 2020 CARB SIP Submittal, page 6.

                          Table 1--2017 Average Ozone Season Day Emissions Inventories
                                                      [tpd]
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                    Category                            NOX         % of total          VOC         % of total
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                                                  Amador County
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Stationary Sources..............................            2.21              59            0.88              23
Area-wide Sources...............................            0.05               1            1.55              41
On-road Mobile..................................            1.05              28            0.64              17
Off-Road Mobile.................................            0.44              12            0.72              19
                                                 ---------------------------------------------------------------
    Total.......................................            3.76             100            3.79             100
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                                                  Butte County
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Stationary Sources..............................            1.11               9            2.07              17
Area-wide Sources...............................            0.68               5            5.09              42
On-road Mobile..................................            4.94              39            2.52              21
Off-Road Mobile.................................            5.92              47            2.52              21
                                                 ---------------------------------------------------------------
    Total.......................................           12.65             100           12.19             100
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[[Page 54890]]

 
                                                Calaveras County
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Stationary Sources..............................            0.04               2            0.19               4
Area-wide Sources...............................             0.1               5            2.05              43
On-road Mobile..................................             1.4              63            0.84              18
Off-Road Mobile.................................            0.67              30            1.66              35
                                                 ---------------------------------------------------------------
    Total.......................................            2.21             100            4.74             100
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                                                 Imperial County
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Stationary Sources..............................            1.38               9            1.33              10
Area-wide Sources...............................            0.21               1            6.88              49
On-road Mobile..................................            6.05              41             2.6              19
Off-Road Mobile.................................            7.14              48            3.18              23
                                                 ---------------------------------------------------------------
    Total.......................................           14.78             100           13.98             100
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                                           Kern County (Eastern Kern)
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Stationary Sources..............................           18.13              67             1.4              20
Area-wide Sources...............................            0.12               0            1.17              16
On-road Mobile..................................            3.94              15            1.27              18
Off-Road Mobile.................................            4.82              18            3.33              46
                                                 ---------------------------------------------------------------
    Total.......................................           27.01             100            7.18             100
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                            Los Angeles--San Bernardino Counties (West Mojave Desert)
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Stationary Sources..............................           23.95              32           13.88              36
Area-wide Sources...............................            0.93               1           10.85              28
On-road Mobile..................................           23.06              31            9.03              23
Off-Road Mobile.................................           27.02              36            4.89              13
                                                 ---------------------------------------------------------------
    Total.......................................           74.95             100           38.64             100
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                                       Los Angeles--South Coast Air Basin
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Stationary Sources..............................           43.28              12           94.27              23
Area-wide Sources...............................           10.35               3          125.28              30
On-road Mobile..................................          180.29              51           91.96              22
Off-Road Mobile.................................          118.41              34           99.25              24
                                                 ---------------------------------------------------------------
    Total.......................................          352.32             100          410.75             100
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                                                 Mariposa County
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Stationary Sources..............................            0.02               2            0.07               3
Area-wide Sources...............................            0.01               1            1.33              51
On-road Mobile..................................            0.48              59            0.34              13
Off-Road Mobile.................................             0.3              37            0.89              34
                                                 ---------------------------------------------------------------
    Total.......................................             0.8             100            2.63             100
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                                          Nevada County (Western part)
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Stationary Sources..............................             0.1               3            0.76              16
Area-wide Sources...............................            0.15               4            1.65              35
On-road Mobile..................................             2.8              72            1.21              26
Off-Road Mobile.................................            0.82              21            1.07              23
                                                 ---------------------------------------------------------------
    Total.......................................            3.86             100            4.68             100
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                                       Riverside County (Coachella Valley)
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Stationary Sources..............................            1.31               7            3.58              24
Area-wide Sources...............................            0.29               1            3.82              26
On-road Mobile..................................           12.19              62            4.22              29
Off-Road Mobile.................................            5.91              30            3.09              21
                                                 ---------------------------------------------------------------
    Total.......................................            19.7             100           14.71             100
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[[Page 54891]]

 
                                                Sacramento Metro
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Stationary Sources..............................            6.21               9           23.31              25
Area-wide Sources...............................            2.34               3           31.69              34
On-road Mobile..................................           36.37              53           19.68              21
Off-Road Mobile.................................           24.25              35           19.79              21
                                                 ---------------------------------------------------------------
    Total.......................................           69.16             100           94.46             100
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                                             San Francisco Bay Area
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Stationary Sources..............................           32.96              17           68.49              29
Area-wide Sources...............................            6.79               4            76.8              33
On-road Mobile..................................           78.28              41           41.21              18
Off-Road Mobile.................................           72.87              38            46.6              20
                                                 ---------------------------------------------------------------
    Total.......................................           190.9             100           233.1             100
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                                               San Joaquin Valley
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Stationary Sources..............................           28.04              13           83.75              27
Area-wide Sources...............................            4.21               2          154.67              50
On-road Mobile..................................          100.38              46           34.06              11
Off-Road Mobile.................................           87.57              40           35.37              11
                                                 ---------------------------------------------------------------
    Total.......................................           220.2             100          307.85             100
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                                         San Luis Obispo (Eastern part)
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Stationary Sources..............................            0.45              58            0.09              20
Area-wide Sources...............................            0.01               1            0.22              49
On-road Mobile..................................             0.2              26             0.1              22
Off-Road Mobile.................................            0.12              15            0.04               9
                                                 ---------------------------------------------------------------
    Total.......................................            0.77             100            0.44             100
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                                                 Tuolumne County
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Stationary Sources..............................            1.05              28             0.5               7
Area-wide Sources...............................            0.07               2            2.15              30
On-road Mobile..................................            1.59              42            1.15              16
Off-Road Mobile.................................            1.08              28            3.38              47
                                                 ---------------------------------------------------------------
    Total.......................................            3.78             100            7.18             100
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                                                 Ventura County
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Stationary Sources..............................            2.02              11            8.08              27
Area-wide Sources...............................            0.63               3           10.45              35
On-road Mobile..................................            8.41              44            5.08              17
Off-Road Mobile.................................            8.09              42            6.63              22
                                                 ---------------------------------------------------------------
    Total.......................................           19.14             100           30.23             100
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Source: Attachment A of 2020 CARB SIP Submittal. The sum of the emissions values may not equal the totals shown
  due to rounding. The table excludes biogenic emissions. Additionally, there are no anthropogenic emissions
  from the Sutter Buttes and Tuscan Buttes NAAs.

1. Stationary Point Source Emissions
    CARB estimates stationary point source emissions based on annual 
reports submitted by the local air districts. The inventory reflects 
actual emissions from industrial point sources reported to local air 
districts by facility operators through calendar year 2017.\21\ The 
local air districts are responsible for working with facility operators 
to compile estimates, using source testing, direct measurement, or 
engineering calculations. CARB estimates emissions from smaller point 
sources, such as gasoline dispensing facilities and residential water 
heaters, as a group and reports them in a single source category. CARB 
groups stationary point source emissions into the following categories: 
Fuel combustion, waste disposal, cleaning and surface coatings, 
petroleum production and marketing, and industrial processes.\22\
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    \21\ 2020 CARB SIP Submittal, page 14.
    \22\ 2020 CARB SIP Submittal, Attachment A. Fuel combustion 
subcategories: Electric utilities, cogeneration, oil and gas 
production (combustion), manufacturing and industrial, food and 
agricultural processing, service and commercial, other (fuel 
combustion). Waste disposal subcategories: Sewage treatment, 
incinerators, other (waste disposal). Cleaning and surface coatings 
subcategories: Laundering, degreasing, coatings and related process 
solvents, printing, adhesives, and sealants. Petroleum productions 
and marketing subcategories: Oil and gas production, petroleum 
marketing, other (petroleum production and marketing). Industrial 
processes subcategories: Food agriculture, mineral processes, metal 
processes, wood and paper, other (industrial processes).

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[[Page 54892]]

    CARB describes the methodologies it uses for smaller point sources 
in Section II.B of the ``Emission Inventory Components'' summary of the 
2020 CARB SIP Submittal.\23\ The categories for these smaller point 
sources include: Stationary non-agricultural diesel engines, 
agricultural diesel irrigation pumps, wine fermentation and aging, 
laundering, degreasing, coatings and thinners, adhesives and sealants, 
gasoline dispensing facilities, gasoline cargo tank, marine petroleum 
loading, marine petroleum unloading, and oil and gas production. In 
addition to describing each category, CARB provides website links to 
additional information on each methodology. For example, while CARB 
reports most of the food and agricultural processing emissions sources 
as individual point sources, CARB estimates the exhaust emissions from 
agricultural irrigation pumps from a model developed by CARB staff. 
This category includes emissions from the operation of diesel-fueled 
stationary and mobile agricultural irrigation pumps.\24\
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    \23\ 2020 CARB SIP Submittal, pages 14-19.
    \24\ Section II.B.b of 2020 CARB SIP Submittal, page 15. 
Additional information on agricultural diesel irrigation pumps is 
available at https://ww3.arb.ca.gov/ei/areasrc/fullpdf/full1-1.pdf.
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2. Area-Wide Source Emissions
    CARB's area-wide source inventories include categories where 
emissions take place over a wide geographic area, such as consumer 
products, cooking, and agricultural burning. CARB groups area-wide 
source emissions as either solvent evaporation or miscellaneous 
processes.\25\
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    \25\ 2020 CARB SIP Submittal, Attachment A. Solvent evaporation 
subcategories: Consumer products, architectural coatings and related 
process solvents, pesticides/fertilizers, asphalt paving/roofing. 
Miscellaneous processes subcategories: Residential fuel combustion, 
farming operations, construction and demolition, paved road dust, 
unpaved road dust, fugitive windblown dust, fires, managed burning 
and disposal, cooking, and other (miscellaneous processes).
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    CARB describes the methodologies for each area-wide source 
emissions category in Section II.C of the ``Emission Inventory 
Components'' summary of the 2020 CARB SIP Submittal.\26\ Area-wide 
source emissions estimates are developed by CARB staff as well as some 
air districts. The methodologies are reviewed by CARB and air district 
staff before inclusion in the emissions inventory. CARB uses various 
models and methodologies for estimating emissions from area-wide source 
categories. CARB also provides information describing the methodologies 
used for the following area-wide sources: Consumer products and aerosol 
coatings, architectural coatings, pesticides, residential wood 
combustion, residential natural gas combustion, residential distillate 
oil and liquified petroleum gas, farming operations, fires, managed 
burning and disposal, and commercial cooking.\27\ In addition to 
describing each category, CARB provides website links to additional 
information on each methodology. A few examples are provided below.
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    \26\ 2020 CARB SIP Submittal, pages 19-22.
    \27\ 2020 CARB SIP Submittal, pages 19-22.
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    For the consumer products emissions estimates, CARB utilized sales 
and formulation data from CARB's mandatory survey of all consumer 
products sold in California for calendar years 2013 through 2015.\28\ 
Based on the survey data, CARB staff determined the total product sales 
and total VOC emissions for the various product categories. Growth for 
personal care products is based on real disposable personal income 
projections per Regional Economic Models, Inc. (REMI) version 2.3. No 
growth is assumed for aerosol coatings. Growth for all other personal 
care products is based on California Department of Finance.
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    \28\ 2020 CARB SIP Submittal, page 19. Additional information on 
CARB's consumer products surveys is available at: https://ww2.arb.ca.gov/our-work/programs/consumer-products-program/consumer-commercial-product-surveys.
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    The California Department of Pesticide Regulation (DPR) develops 
month-specific emissions estimates for agricultural and structural 
pesticides for CARB.\29\ The DPR applies Emission Potential values from 
the DPR database to the amount of grower-reported pesticide application 
in DPR's Pesticide Use Report database.\30\
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    \29\ 2020 CARB SIP Submittal, page 20. Additional information 
about CARB's pesticides program is available at: https://ww2.arb.ca.gov/solvent-evaporation-methodologies.
    \30\ The EP value is the fraction of the product that is assumed 
to potentially contribute to atmospheric VOC. California's pesticide 
use reporting program requires that all agricultural pesticide use 
must be reported monthly by growers to county agricultural 
commissions, who in turn, report the data to DPR. See https://ww2.arb.ca.gov/solvent-evaporation-methodologies.
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    CARB uses survey data and emissions factors to estimate emissions 
from residential wood combustion, a subcategory of residential fuel 
combustion.\31\ In 2011, CARB updated its methodology for residential 
wood combustion to include more recent survey data on residential wood 
burning devices and consumption rates, updates to the EPA National 
Emissions Inventory emissions factors and improved calculation 
approaches.\32\ The update reflects wood combustion surveys conducted 
by several districts including the Bay Area Air Quality Management 
District (AQMD) in 2007, South Coast AQMD in 2003 and 2006, Placer 
County Air Pollution Control District (APCD) in 2007, San Joaquin 
Valley APCD in 2014, and Sacramento Metropolitan AQMD in 2007. CARB 
also assumes no growth for this category based on the relatively 
stagnant residential wood fuel use over the past decade according to 
the American Community Survey and United States Energy Information 
Administration.
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    \31\ 2020 CARB SIP Submittal, page 20. Additional information on 
this methodology is available at: https://ww2.arb.ca.gov/miscellaneous-process-methodologies.
    \32\ CARB, Section 7.1 Residential Wood Combustion (Revised 
October 2015), available at: http://www.arb.ca.gov/ei/areasrc/fullpdf/full7-1_2011.pdf.
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3. Off-Road Mobile Source Emissions
    CARB has developed category-specific models for numerous off-road 
(also known as ``nonroad'') sources, including locomotives, ships, 
industrial and construction equipment, and recreational vehicles.\33\ 
CARB estimated emissions from off-road sources using a suite of 
category-specific models or, where a new model was not available, the 
OFFROAD2007 model. The submittal indicated that many of the newer 
models were developed to support recent regulations, including in-use 
off-road equipment, ocean-going vessels, and others. CARB provided 
information describing the updates made to following off-road sources: 
Ocean going vessels,\34\ commercial harbor craft, pleasure crafts and 
recreational vehicles, locomotives, fuel storage and handling 
equipment, fuel storage and handling, diesel agricultural equipment, 
in-use off-road equipment (i.e., construction, industrial, mining, oil 
drilling, and ground support equipment), cargo handling equipment, and 
transportation refrigeration units.\35\ In addition to describing each 
category, CARB provides website links to additional information on each 
methodology. These descriptions include the type of source represented,

[[Page 54893]]

the types and source of data used, and the models used.
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    \33\ 2020 CARB SIP Submittal, pages 11-14.
    \34\ CARB clarified via email that the link for ocean going 
vessels was updated to: https://ww3.arb.ca.gov/msei/offroad/pubs/2019_ogv_inventory_writeup_ver_oct_18_2019.pdf. See email dated 
February 9, 2021, from Stephanie Huber, CARB to Khoi Nguyen, EPA 
Region IX.
    \35\ Aircrafts are also considered off-road mobile sources. In 
CARB's February 9, 2021 email, CARB clarified that aircraft 
emissions are estimated by the districts.
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    For example, CARB groups commercial harbor craft into nine vessel 
types, including ferry and excursion vessels, tow boats, tugboats, 
pilot vessels, work boats, crew and supply vessels, commercial fishing 
vessels, charter fishing vessels, and other.\36\ Vessel and engine data 
were reported to CARB by vessel operators in compliance with CARB's 
2007 Commercial Harbor Craft Regulation. Staff updated the crew and 
supply vessel emissions inventory using 2009 reporting data and 
developed barge and dredge vessel emissions inventory using information 
from a 2009 CARB survey. Vessel population data were collected from 
various sources, including the U.S. Coast Guard, the California 
Department of Fish and Wildlife registration data, the CARB Harbor 
Craft Survey, and information from recent emissions inventory estimates 
generated for Los Angeles. Vessel and engine profiles, including vessel 
and engine type, age, size, annual hours of operation, and annual fuel 
use were developed based on the CARB survey.
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    \36\ 2020 CARB SIP Submittal, page 11. Additional information on 
CARB's CHC methodology is available at: https://www.arb.ca.gov/regact/2010/chc10/appc.pdf.
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4. On-Road Mobile Source Emissions
    CARB estimated on-road mobile emissions from cars, light and heavy-
duty trucks, motorcycles, buses, and motor homes using its Emission 
Factors (EMFAC) model version 2017,\37\ which was the latest EPA-
approved version available at the time the emissions inventories were 
prepared.\38\ The on-road emissions were calculated by applying 
EMFAC2017 emissions factors to the transportation activity data 
provided by the local metropolitan planning organizations. CARB states 
that EMFAC2017 includes data on California's car and truck fleets and 
travel activity. Light-duty motor vehicle fleet age, vehicle type, and 
vehicle population were based on data from the Department of Motor 
Vehicles (DMV), updated in 2016. The model also reflects the emissions 
benefits of CARB's rulemakings such as the Pavley Standards and 
Advanced Clean Cars Program and includes the emissions benefits from 
CARB's Truck and Bus Rule and previously adopted rules for other on-
road diesel fleets. CARB also indicates that EMFAC2017 utilizes a 
socio-econometric regression modeling approach to forecast new vehicle 
sales and to estimate future fleet mix. Light-duty passenger vehicle 
population includes 2016 DMV registration data along with updates to 
mileage accrual using data from the Bureau of Automotive Repair Smog 
Check Program. Updates to heavy-duty trucks include model year specific 
emissions factors based on new test data, and population estimates 
using DMV data for in-state trucks and International Registration Plan 
data for out-of-state trucks.
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    \37\ EMFAC is short for EMission FACtor. In August 2019, the EPA 
approved EMFAC2017 for SIP development and transportation purposes 
in California. 84 FR 41717 (August 15, 2019). CARB provides 
additional information and documentation on the EMFAC2017 model, 
available at: https://ww2.arb.ca.gov/our-work/programs/mobile-source-emissions-inventory/msei-road-documentation.
    \38\ 2020 CARB SIP Submittal, page 10.
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C. The EPA's Evaluation of the State's Submittal

1. Evaluation of Procedural Requirements
    Based on the documentation included in CARB's submittal, the EPA 
finds that the submittal satisfies the procedural requirements of 
sections 110(a)(1) and 110(l) of the Act requiring states to provide 
reasonable notice and an opportunity for public hearing prior to 
adoption of SIP revisions. CARB's submittal became complete by 
operation of law on January 24, 2021 pursuant to section 110(k)(1)(B).
2. Evaluation of Base Year Inventory Requirements
    The EPA has reviewed the 2020 CARB SIP Submittal for consistency 
with sections 172(c)(3) and 182(a)(1) of the CAA, and the EPA's 
emissions inventory requirements. In particular, the EPA has reviewed 
the techniques used by CARB to derive and quality assure the emissions 
estimates.
    CARB documented the procedures used to estimate the emissions for 
each of the major source types. The documentation of the emissions 
estimation procedures is adequate for the EPA to determine that CARB 
followed acceptable procedures to estimate emissions.
    CARB has established a quality assurance and quality control (QA/
QC) process to ensure the integrity and accuracy of the emissions 
inventories used in the development of air quality plans. These QA/QC 
procedures were summarized in the documentation describing how the 
emissions totals were developed.\39\ The EPA has determined that the 
QA/QC procedures are complete, adequate, and acceptable.
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    \39\ 2020 CARB SIP Submittal, page 9.
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    The EPA has also reviewed the 2017 average ozone season day base 
year emissions inventories in the 2020 CARB SIP Submittal. Our review 
included the emissions estimates for stationary sources, area-wide 
sources, and mobile sources. We find that CARB's selection of 2017 as 
the base year was appropriate for these areas because 2017 was the most 
recent calendar year for which a consistent and comprehensive statewide 
inventory was available. We also find that the emissions inventories 
appropriately address ozone season day emissions consistent with the 
definition of ozone season day emissions under 40 CFR 51.1300(q). The 
submittal provides sufficient information and explanation to allow the 
EPA to make a determination on the acceptability of the emissions 
inventories.
    The EPA proposes to find that CARB has developed approvable 
inventories of NOX and VOC emissions for the following ozone 
nonattainment areas as required under the CAA and SRR (40 CFR 51.1315, 
see also CAA section 172(c)(3)): Amador County, Butte County, Calaveras 
County, Imperial County, Kern County (Eastern Kern), Los Angeles--San 
Bernardino Counties (West Mojave Desert), Los Angeles--South Coast Air 
Basin, Mariposa County, Nevada County (Western part), Riverside County 
(Coachella Valley), Sacramento Metro, San Francisco Bay Area, San 
Joaquin Valley, San Luis Obispo (Eastern part), Sutter Buttes, Tuolumne 
County, Tuscan Buttes, and Ventura County.

III. Proposed Action

    We are proposing to approve the 2020 CARB SIP Submittal to address 
the ozone-related emissions inventory requirements for 18 ozone 
nonattainment areas for the 2015 ozone NAAQS. These areas are: Amador 
County, Butte County, Calaveras County, Imperial County, Kern County 
(Eastern Kern), Los Angeles--San Bernardino Counties (West Mojave 
Desert), Los Angeles--South Coast Air Basin, Mariposa County, Nevada 
County (Western part), Riverside County (Coachella Valley), Sacramento 
Metro, San Francisco Bay Area, San Joaquin Valley, San Luis Obispo 
(Eastern part), Sutter Buttes, Tuolumne County, Tuscan Buttes, and 
Ventura County. The emissions inventories we are approving into the SIP 
are specified in Table 1. We are proposing to approve the emissions 
inventories because they contain comprehensive, accurate, and current 
inventories of actual emissions for all relevant sources in accordance 
with CAA sections 172(c)(3) and 182(a), and because CARB adopted the 
emissions inventories after providing for

[[Page 54894]]

reasonable public notice and opportunity for a public hearing.

IV. Statutory and Executive Order Reviews

    Under the Clean Air Act, 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, the EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. 
Accordingly, this proposed action merely proposes to approve state law 
as meeting federal requirements and does not impose additional 
requirements beyond those imposed by state law. For that reason, this 
proposed action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the Clean Air Act; and
     Does not provide the EPA with the discretionary authority 
to address disproportionate human health or environmental effects with 
practical, appropriate, 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 the EPA or an Indian tribe 
has demonstrated that a tribe has jurisdiction. In those areas of 
Indian country, the rule does not have tribal implications 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, Incorporation by 
reference, Intergovernmental relations, Ozone, Reporting and 
recordkeeping requirements, Volatile organic compounds.

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

    Dated: September 29, 2021.
Deborah Jordan,
Acting Regional Administrator, Region IX.
[FR Doc. 2021-21738 Filed 10-4-21; 8:45 am]
BILLING CODE 6560-50-P


