# Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality Planning Purposes; California; South Coast Moderate Area Plan and Reclassification as Serious Nonattainment for the 2012 PM2.5 NAAQS

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2020-12690

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** July 2, 2020
- **Citation:** 85 FR 40026

## Text

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[EPA-R09-OAR-2019-0145; FRL-10010-50-Region 9]

Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality Planning Purposes; California; South Coast Moderate Area Plan and Reclassification as Serious Nonattainment for the 2012 PM
2.5
NAAQS

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to approve or conditionally approve portions of a state implementation plan (SIP) revision submitted by California to address Clean Air Act (CAA or “Act”) requirements for the 2006 and 2012 fine particulate matter (PM
2.5
) national ambient air quality standards (NAAQS or “standards”) in the Los Angeles-South Coast Air Basin (“South Coast”) PM
2.5
nonattainment area. Specifically, the EPA is proposing to approve all but the contingency measure element of the submitted SIP revision as meeting all applicable Moderate area requirements for the 2012 annual PM
2.5
NAAQS, and to conditionally approve the contingency measure element as meeting both the Moderate area contingency measure requirement for the 2012 annual PM
2.5
NAAQS and the Serious area contingency measure requirement for the 2006 24-hour PM
2.5
NAAQS. In addition, the EPA is proposing to approve 2019 and 2022 motor vehicle emissions budgets for use in transportation conformity analyses for the 2012 annual PM
2.5
NAAQS. The EPA is also proposing to reclassify the South Coast PM
2.5
nonattainment area, including reservation areas of Indian country and any other area of Indian country within it where the EPA or a tribe has demonstrated that the tribe has jurisdiction, as a Serious nonattainment area for the 2012 annual PM
2.5
NAAQS based on the EPA's determination that the area cannot practicably attain the standard by the applicable Moderate area attainment date of December 31, 2021. Upon final reclassification of the South Coast as a Serious area for this NAAQS, California will be required to submit a Serious area plan for the area that includes a demonstration of attainment by the applicable Serious area attainment date, which is no later than December 31, 2025, or by the most expeditious alternative date practicable, in accordance with the requirements of part D of title I of the CAA.

DATES:

Any comments on this proposal must be received by August 3, 2020.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R09-OAR-2019-0145 at
https://www.regulations.gov,
or via email to
graham.ashleyr@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, 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 (
e.g.,
audio or video) 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.

FOR FURTHER INFORMATION CONTACT:

Ashley Graham, Air Planning Office (AIR-2), EPA Region IX, (415) 972-3877,
graham.ashleyr@epa.gov.

SUPPLEMENTARY INFORMATION:

Throughout this document, “we,” “us,” or “our” refer to the EPA.

Table of Contents

I. Background for Proposed Action

II. Summary of the South Coast PM
2.5
Plan

III. Clean Air Act Requirements for Moderate PM
2.5
Nonattainment Area Plans

IV. Completeness Review of the South Coast PM
2.5
Plan

V. Review of the South Coast PM
2.5
Plan

A. Emissions Inventory

B. PM
2.5
Precursors

C. Air Quality Modeling

D. Reasonably Available Control Measures and Control Strategy

E. Major Stationary Source Control Requirements Under CAA Section 189(e)

F. Demonstration That Attainment by the Moderate Area Attainment Date Is Impracticable

G. Reasonable Further Progress and Quantitative Milestones

H. Contingency Measures

I. Motor Vehicle Emissions Budgets

VI. Reclassification as Serious Nonattainment and Serious Area SIP Requirements

A. Reclassification as Serious and Applicable Attainment Date

B. Clean Air Act Requirements for Serious PM
2.5
Nonattainment Area Plans

C. Statutory Deadline for Submittal of the Serious Area Plan

VII. Reclassification of Areas of Indian Country

VIII. Summary of Proposed Actions and Request for Public Comment

IX. Statutory and Executive Order Reviews

I. Background for Proposed Action

On October 17, 2006, the EPA strengthened the 24-hour (daily) NAAQS for particulate matter with a diameter of 2.5 microns or less (PM
2.5
) by lowering the level from 65 micrograms (µg) per cubic meter (m
3
) to 35 µg/m
3
(“2006 PM
2.5
NAAQS”).
1

On January 15, 2013, the EPA strengthened the primary annual NAAQS for PM
2.5
by lowering the level from 15.0 µg/m
3
to 12.0 µg/m
3
(“2012 PM
2.5
NAAQS”).
2

The EPA established these standards after considering substantial evidence from numerous health studies demonstrating that serious health effects are associated with exposures to PM
2.5
concentrations above these levels.

1
71 FR 61144 and 40 CFR 50.13. The EPA first established NAAQS for PM
2.5
on July 18, 1997 (62 FR 38652), including annual standards of 15.0 µg/m
3
based on a 3-year average of annual mean concentrations and 24-hour (daily) standards of 65 µg/m
3
based on a 3-year average of 98th percentile 24-hour concentrations (40 CFR 50.7).

2
78 FR 3086 and 40 CFR 50.18. Unless otherwise noted, all references to the PM
2.5
standards in this notice are to the 2012 annual NAAQS of 12.0 µg/m
3
codified at 40 CFR 50.18.

Epidemiological studies have shown statistically significant correlations between elevated PM
2.5
levels and premature mortality. Other important health effects associated with PM
2.5
exposure include aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions, emergency room visits, absences from school or work, and restricted activity days), changes in lung function, and increased respiratory symptoms. Individuals particularly sensitive to PM
2.5
exposure include older adults, people with heart and lung disease, and children.
3

PM
2.5
can be emitted directly into the atmosphere as a solid or liquid particle (“primary PM
2.5
” or “direct PM
2.5
”) or can be formed in the atmosphere (“secondary PM
2.5
”) as a result of various chemical reactions among precursor pollutants such as nitrogen oxides (NO
X
), sulfur oxides (SO
X
), volatile organic

compounds (VOC), and ammonia (NH
3
).
4

3
Id.

4
EPA, Air Quality Criteria for Particulate Matter, No. EPA/600/P-99/002aF and EPA/600/P-99/002bF, October 2004.

Following promulgation of a new or revised NAAQS, the EPA is required by CAA section 107(d) to designate areas throughout the nation as attaining or not attaining the NAAQS. On November 13, 2009, the EPA designated the South Coast area as nonattainment for the 2006 PM
2.5
NAAQS.
5

The EPA classified the area as Moderate nonattainment on June 2, 2014 and reclassified it as Serious nonattainment for these NAAQS on January 13, 2016.
6

On January 15, 2015, the EPA designated and classified the South Coast area as Moderate nonattainment for the 2012 PM
2.5
NAAQS.
7

The South Coast area is also designated and classified as Moderate nonattainment for the 1997 annual and 24-hour PM
2.5
NAAQS.
8

5
74 FR 58688 (codified at 40 CFR 81.305).

6
79 FR 31566 and 81 FR 1514. The EPA promulgated these PM
2.5
nonattainment area classifications in response to a 2013 decision of the Court of Appeals for the D.C. Circuit remanding the EPA's prior implementation rule for the PM
2.5
NAAQS and directing the EPA to promulgate implementation rules pursuant to subpart 4 of part D, title I of the Act.
Natural Resources Defense Council
v.
EPA,
706 F.3d 428 (D.C. Cir. 2013).

7
80 FR 2206 (codified at 40 CFR 81.305).

8
70 FR 944 (January 5, 2005) (codified at 40 CFR 81.305). In November 2007, California submitted the 2007 PM
2.5
Plan to provide for attainment of the 1997 PM
2.5
standards in the South Coast. On November 9, 2011, the EPA approved all but the contingency measures in the 2007 PM
2.5
Plan (76 FR 69928), and on October 29, 2013, the EPA approved a revised contingency measure SIP for the area (78 FR 64402). On July 25, 2016, the EPA determined that the South Coast area had attained the 1997 annual and 24-hour PM
2.5
NAAQS based on 2011-2013 monitoring data, suspending any remaining attainment-related planning requirements for purposes of the 1997 PM
2.5
NAAQS in this area (81 FR 48350).

On April 27, 2017, the California Air Resources Board (CARB) submitted the “Final 2016 Air Quality Management Plan (March 2017)” to provide for attainment of both the 2006 PM
2.5
NAAQS and the 2012 PM
2.5
NAAQS in the South Coast (“2016 PM
2.5
Plan” or “Plan”).
9

On February 12, 2019, the EPA approved those portions of the 2016 PM
2.5
Plan that pertain to the requirements for implementing the 2006 PM
2.5
NAAQS, except for the contingency measure component of the Plan.
10

9
Letter dated April 27, 2017, from Richard Corey, Executive Officer, CARB, to Alexis Strauss, Acting Regional Administrator, EPA Region IX (transmitting “Final 2016 Air Quality Management Plan (March 2017)”).

10
84 FR 3305. As part of this action, the EPA found that, for purposes of the 2006 PM
2.5
NAAQS, the requirement for contingency measures to be undertaken if the area fails to make RFP under CAA section 172(c)(9) was moot as applied to the 2017 milestone year because CARB and the District had demonstrated to the EPA's satisfaction that the 2017 milestones in the plan had been met. The EPA took no action with respect to RFP contingency measures for the 2020 milestone year or attainment contingency measures for these NAAQS.

The South Coast PM
2.5
nonattainment area is home to about 17 million people, has a diverse economic base, and contains one of the highest-volume port areas in the world. For a description of the geographic boundaries of the South Coast PM
2.5
nonattainment area, see 40 CFR 81.305. The local air district with primary responsibility for developing a plan to attain the PM
2.5
NAAQS in the South Coast area is the South Coast Air Quality Management District (SCAQMD or “District”). The District works cooperatively with CARB in preparing these plans. Authority for regulating sources in the South Coast is split between the District, which has responsibility for regulating stationary and most area sources, and CARB, which has responsibility for regulating most mobile sources and some categories of consumer products.

II. Summary of the South Coast PM
2.5
Plan

We are proposing action on portions of a California SIP submission that address the Moderate area plan requirements for the 2012 annual PM
2.5
NAAQS and the Serious area contingency measure requirement for the 2006 24-hour PM
2.5
NAAQS in the South Coast PM
2.5
nonattainment area. The SCAQMD Governing Board adopted the “Final 2016 Air Quality Management Plan (March 2017)” on March 3, 2017, and CARB submitted this SIP revision to the EPA on April 27, 2017.
11

We refer to this SIP submission herein as the “2016 PM
2.5
Plan” or “Plan.”

11
Letter dated April 27, 2017, from Richard Corey, Executive Officer, CARB, to Alexis Strauss, Acting Regional Administrator, EPA Region IX, with enclosures.

The 2016 PM
2.5
Plan is organized into eleven chapters, each addressing a specific topic. We summarize below each of the chapters relevant to the 2012 PM
2.5
NAAQS and the contingency measure requirement for the 2006 PM
2.5
NAAQS.
12

Chapter 1, “Introduction,” provides general background, including a discussion of the purpose of the Plan, historical air quality progress in the South Coast, and the District's approach to air quality planning. Chapter 2, “Air Quality and Health Effects,” discusses current air quality in comparison with federal health-based air pollution standards. Chapter 3, “Base Year and Future Year Emissions,” summarizes emissions inventories, estimates current emissions by source and pollutant, and projects future emissions with and without growth. Chapter 4, “Control Strategy and Implementation,” presents the control strategy, specific measures, and implementation schedules to attain the air quality standards by the specified attainment dates. Chapter 5, “Future Air Quality,” describes the modeling approach used in the Plan and summarizes the South Coast's future air quality projections with and without the control strategy. Chapter 6, “Federal and State Clean Air Act Requirements,” discusses specific federal and state requirements as they pertain to the South Coast, including anti-backsliding requirements for revoked standards. Chapter 11, “Public Process and Participation,” describes the District's public outreach effort associated with the development of the Plan. Finally, a glossary is provided at the end of the document, presenting definitions of terms commonly used in the Plan.

12
The following chapters in the Plan are not relevant to the 2006 or 2012 PM
2.5
NAAQS and were not reviewed as part of this action: Chapter 7, “Current and Future Air Quality—Desert Nonattainment Areas,” describes the air quality status of the Coachella Valley, including emissions inventories, designations, and current and future air quality. Chapter 8, “Looking Beyond Current Requirements,” assesses the South Coast air basin's status with respect to the 2015 8-hour ozone standard of 70 ppb. Chapter 9, “Air Toxic Control Strategy,” examines the ongoing efforts to reduce health risk from toxic air contaminants, co-benefits from reducing criteria pollutants, and potential future actions; and Chapter 10, “Climate and Energy,” provides a description of current and projected energy demand and supply issues in the South Coast air basin, and the relationship between air quality improvement and greenhouse gas mitigation goals.

The Plan also includes the following technical appendices:

• Appendix I (“Health Effects”) presents a summary of scientific findings on the health effects of ambient air pollution.

• Appendix II (“Current Air Quality”) contains a detailed summary of the air quality in 2014, along with prior year trends, in both the South Coast and the Coachella Valley.

• Appendix III (“Base and Future Year Emission Inventory”) presents the 2012 base year emissions inventory and projected emissions inventories of air pollutants in future attainment years for both annual average and summer planning inventories.

• Appendix IV-A (“SCAQMD's Stationary and Mobile Source Control Measures”) describes SCAQMD's proposed stationary and mobile source control measures to attain the federal ozone and PM
2.5
standards.

• Appendix IV-B (“CARB's Mobile Source Strategy”) describes CARB's proposed 2016 strategy to attain health-based federal air quality standards.

• Appendix IV-C (“Regional Transportation Strategy and Control Measures”) describes the Southern California Association of Governments' (SCAG) “Final 2016-2040 Regional Transportation Plan/Sustainable Communities Strategy” and transportation control measures included in the 2016 PM
2.5
Plan.

• Appendix V (“Modeling and Attainment Demonstrations”) provides the details of the regional modeling for the attainment demonstration.

• Appendix VI (“Compliance with Other Clean Air Act Requirements”) provides the District's demonstration that the Plan complies with specific federal and California Clean Air Act requirements.

CARB adopted additional documents on March 23, 2017 that supplement the analyses and demonstrations adopted by the SCAQMD on March 3, 2017. In particular, the “CARB Staff Report, ARB Review of 2016 AQMP for the South Coast Air Basin and Coachella Valley” (“CARB Staff Report”) includes in Appendix D a weight of evidence analysis for the SCAQMD's attainment demonstration for the 24-hour and annual PM
2.5
NAAQS. Also, to supplement the contingency measure element of the 2016 PM
2.5
Plan, CARB submitted a letter dated January 29, 2019 containing the District's commitment to adopt a control measure by a date certain for purposes of satisfying CAA contingency measure requirements for the 2006 and 2012 PM
2.5
NAAQS.
13

The District later clarified its January 29, 2019 commitment in a letter dated February 12, 2020, and CARB submitted the District's clarified commitment together with related State commitments to the EPA by letter dated March 3, 2020.
14

We discuss these commitments as part of our evaluation of the contingency measure element of the 2016 PM
2.5
Plan, in section V.H.

13
Letter dated February 13, 2019, from Michael Benjamin, Air Quality Planning and Science Division, CARB, to Mike Stoker, Regional Administrator, EPA Region IX (transmitting letter dated January 29, 2019, from Wayne Nastri, Executive Officer, SCAQMD, to Richard Corey, Executive Officer, CARB). In its January 29, 2019 letter, the District committed to modify an existing rule or adopt a new rule to create a contingency measure that would be triggered if the area fails to meet an RFP requirement, to submit a quantitative milestone report, to meet a quantitative milestone, or to attain the 2006 24-hour or 2012 annual PM
2.5
NAAQS.

14
Letter dated March 3, 2020, from Michael Benjamin, Air Quality Planning and Science Division, CARB, to Mike Stoker, Regional Administrator, EPA Region IX (transmitting letter dated February 12, 2020, from Wayne Nastri, Executive Officer, SCAQMD, to Richard Corey, Executive Officer, CARB). In its February 12, 2020 letter, the District specifically committed to modify Rule 445 (“Wood Burning Devices”) to lower the mandatory wood burning curtailment threshold in the rule following any of the EPA findings listed in 40 CFR 51.1014(a). In its March 3, 2020 letter, CARB committed to submit the revised District rule to the EPA as a SIP revision by a date certain.

We present our evaluation of the 2016 PM
2.5
Plan in Section V of this proposed rule.

III. Clean Air Act Requirements for Moderate PM
2.5
Nonattainment Area Plans

With respect to the statutory requirements for particulate matter (PM) attainment plans, the general nonattainment area planning requirements of title I, part D of the CAA are found in subpart 1, and the Moderate area planning requirements specifically for PM are found in subpart 4.

The EPA has a longstanding general guidance document that interprets the 1990 amendments to the CAA, commonly referred to as the General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990 (“General Preamble”).
15

The General Preamble addresses the relationship between the subpart 1 and subpart 4 requirements and provides recommendations to states for meeting certain statutory requirements for PM attainment plans. As explained in the General Preamble, specific requirements applicable to Moderate area attainment plan SIP submissions for the PM NAAQS are set forth in subpart 4 of part D, title I of the Act, but such SIP submissions must also meet the general attainment planning provisions in subpart 1 of part D, title I of the Act, to the extent these provisions “are not otherwise subsumed by, or integrally related to,” the more specific subpart 4 requirements.
16

15
General Preamble, 57 FR 13498 (April 16, 1992).

16
Id. at 13538.

To implement the PM
2.5
NAAQS, the EPA has also promulgated the “Fine Particle Matter National Ambient Air Quality Standard: State Implementation Plan Requirements; Final Rule” (hereinafter, the “PM
2.5
SIP Requirements Rule”).
17

The PM
2.5
SIP Requirements Rule establishes regulatory requirements and provides additional guidance applicable to attainment plan submissions for the PM
2.5
NAAQS, including the 2006 24-hour and 2012 annual PM
2.5
NAAQS at issue in this action.

17
81 FR 58010 (August 24, 2016).

The general subpart 1 statutory requirements for attainment plans include: (i) The section 172(c)(1) requirement for reasonably available control measures (RACM)/reasonably available control technology (RACT) and attainment demonstrations; (ii) the section 172(c)(2) requirement to demonstrate reasonable further progress (RFP); (iii) the section 172(c)(3) requirement for emissions inventories; (iv) the section 172(c)(5) requirement for a nonattainment new source review (NNSR) permitting program; and (v) the section 172(c)(9) requirement for contingency measures.

The more specific subpart 4 statutory requirements for Moderate PM
2.5
nonattainment areas include: (i) The section 189(a)(1)(A) and 189(e) NNSR permit program requirements; (ii) the section 189(a)(1)(B) requirement for attainment demonstrations; (iii) the section 189(a)(1)(C) requirement for RACM; and (iv) the section 189(c) requirements for RFP and quantitative milestones. Under subpart 4, states with Moderate PM
2.5
nonattainment areas must provide for attainment in the area as expeditiously as practicable but no later than the latest permissible attainment date under CAA section 188(c),
i.e.,
December 31, 2021 for the 2012 PM
2.5
NAAQS in the South Coast.
18

In addition, under subpart 4, direct PM
2.5
and all precursors to the formation of PM
2.5
are subject to control unless the EPA approves a demonstration from the State establishing that a given precursor does not contribute significantly to PM
2.5
levels that exceed the PM
2.5
NAAQS in the area.
19

18
Generally, under CAA section 188(c), the latest permissible attainment date for a Moderate nonattainment area is the end of the sixth calendar year after the area's designation as nonattainment. Because the EPA designated and classified the South Coast as a Moderate nonattainment area for the 2012 PM
2.5
NAAQS effective April 15, 2015 (80 FR 2206, 2215), the latest permissible attainment date for these NAAQS in the South Coast is December 31, 2021.

19
40 CFR 51.1006 and 51.1009.

IV. Completeness Review of the South Coast PM
2.5
Plan

CAA sections 110(a)(1) and (2) and 110(l) require each state to provide reasonable public notice and an opportunity for a public hearing prior to the adoption and submittal of a SIP or SIP revision to the EPA. To meet this requirement, every SIP submission should include evidence that adequate public notice was given and an opportunity for a public hearing was provided consistent with the EPA's implementing regulations in 40 CFR 51.102.

Both the District and CARB satisfied applicable statutory and regulatory requirements for reasonable public notice and hearing prior to adoption and

submission of the 2016 PM
2.5
Plan. The District conducted numerous public workshops, provided public comment periods, and held a public hearing prior to its adoption of the Plan on March 3, 2017.
20

CARB also provided the required public notice and opportunity for public comment prior to its March 23, 2017 public hearing and adoption of the Plan.
21

Each submission includes proof of publication of notices for the respective public hearings, and transcripts for the public hearings.
22

We find, therefore, that the 2016 PM
2.5
Plan meets the requirements for reasonable notice and public hearings in CAA sections 110(a) and 110(l).

20
SCAQMD, Notice of Public Hearing, “Proposed 2016 Air Quality Management Plan for the South Coast Air Quality Management District and Report on the Health Impacts of Particulate Matter Air Pollution in the South Coast Air Basin,” December 14, 2016.

21
CARB, “Notice of Public Meeting to Consider Adopting the 2016 Air Quality Management Plan for Ozone and PM
2.5
for the South Coast Air Basin and the Coachella Valley,” March 6, 2017.

22
Memorandum dated March 6, 2017, from Denise Garzaro, Clerk of the Board, SCAQMD, to Arlene Martinez, Administrative Secretary, Planning, Rule Development, and Area Sources, Subject: “SIP Documentation, January 24, 2017; and California Air Resources Board, Notice of Public Meeting to Consider Adopting the 2016 Air Quality Management Plan for Ozone and PM
2.5
for the South Coast Air Basin and the Coachella Valley.”

CAA section 110(k)(1)(B) requires the EPA to determine whether a SIP submittal is complete within 60 days of receipt. This section also provides that any plan that the EPA has not affirmatively determined to be complete or incomplete will become complete by operation of law six months after the date of submission. The EPA's SIP completeness criteria are found in 40 CFR part 51, Appendix V. The 2016 PM
2.5
Plan, which CARB submitted on April 27, 2017, became complete by operation of law on October 27, 2017.

V. Review of the South Coast PM
2.5
Plan

A. Emissions Inventory

1. Requirements for Emissions Inventories

CAA section 172(c)(3) requires that each SIP include a comprehensive, accurate, current inventory of actual emissions from all sources of the relevant pollutant or pollutants in the nonattainment area. We refer to this inventory as the “base year inventory.” The EPA has established regulatory requirements for base year and other emissions inventories in the PM
2.5
SIP Requirements Rule
23

and issued guidance concerning emissions inventories for PM
2.5
nonattainment areas.
24

23
40 CFR 51.1008.

24
81 FR 58010, 58078-58079 and “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” EPA, May 2017 (“Emissions Inventory Guidance”), available at
https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate.

The base year emissions inventory should provide a state's best estimate of actual emissions from all sources of the relevant pollutants in the area,
i.e.,
all emissions that contribute to the formation of a particular NAAQS pollutant. For the PM
2.5
NAAQS, the base year emissions inventory must include direct PM
2.5
emissions, separately reported filterable and condensable PM
2.5
emissions,
25

and emissions of all chemical precursors to the formation of secondary PM
2.5
: NO
X
, SO
2
, VOC, and ammonia.
26

In addition, the emissions inventory base year for a Moderate PM
2.5
nonattainment area must be one of the three years for which monitored data were used to designate the area as nonattainment, or another technically appropriate year justified by the state in its Moderate area SIP submission.
27

25
The Emissions Inventory Guidance identifies the types of sources for which the EPA expects states to provide condensable PM emissions inventories. Emissions Inventory Guidance, section 4.2.1 (“Condensable PM Emissions”), 63-65.

26
40 CFR 51.1008.

27
40 CFR 51.1008(a)(1)(i).

A state must include in its SIP submission documentation explaining how the emissions data were calculated. In estimating mobile source emissions, a state should use the latest emissions models and planning assumptions available at the time it develops the SIP submission. States are also required to use the EPA's “Compilation of Air Pollutant Emission Factors” (AP-42) road dust method for calculating re-entrained road dust emissions from paved roads.
28 29

At the time the 2016 PM
2.5
Plan was developed, California was required to use EMFAC2014 to estimate tailpipe and brake and tire wear emissions of PM
2.5
, NO
X
, SO
2
, and VOC from on-road mobile sources.
30

28
The EPA released an update to AP-42 in January 2011 that revised the equation for estimating paved road dust emissions based on an updated data regression that included new emissions tests results. (76 FR 6328, February 4, 2011). CARB used the revised 2011 AP-42 methodology in developing on-road mobile source emissions; see
http://www.arb.ca.gov/ei/areasrc/fullpdf/full7-9_2016.pdf.

29
AP-42 has been published since 1972 as the primary source of the EPA's emission factor information. It contains emission factors and process information for more than 200 air pollution source categories. A source category is a specific industry sector or group of similar emitting sources. The emission factors have been developed and compiled from source test data, material balance studies, and engineering estimates.

30
The EMFAC model (short for EMission FACtor) is a computer model developed by CARB. The EPA approved and announced the availability of EMFAC2014 for use in SIP development and transportation conformity in California on December 14, 2015 (80 FR 77337). The EPA's approval of the EMFAC2014 emissions model for SIP and conformity purposes was effective on the date of publication in the
Federal Register
. On August 15, 2019, the EPA approved and announced the availability of EMFAC2017, the latest update to the EMFAC model for use by state and local governments to meet CAA requirements (84 FR 41717). EMFAC2017 was not available to the State and District at the time they were developing the 2016 PM
2.5
Plan.

In addition to the base year inventory submitted to meet the requirements of CAA section 172(c)(3), a state must also submit future “baseline inventories” for the projected attainment year, each RFP milestone year, and any other year of significance for meeting applicable CAA requirements.
31

By “baseline inventories” (referred to in the 2016 PM
2.5
Plan as “baseline inventories” or “future baseline inventories”), we mean projected emissions inventories for future years that account for, among other things, the ongoing effects of economic growth and adopted emission control requirements. The SIP submission should include documentation to explain how the state calculated the emissions projections.

31
40 CFR 51.1008(a)(2) and 51.1012(a)(2); see also EPA, “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” May 2017, available at
https://www.epa.gov/sites/production/files/2017-07/documents/ei_guidance_may_2017_final_rev.pdf.

2. Emissions Inventories in the 2016 PM
2.5
Plan

The annual average planning inventories for direct PM
2.5
and all PM
2.5
precursors (NO
X
, SO
X
,
32

VOC, and ammonia) for the South Coast PM
2.5
nonattainment area, together with documentation for the inventories, are found in Chapter 3, Appendix III, and Appendix V of the Plan. Appendix V also contains additional inventory documentation specific to the air quality modeling inventories. These portions of the Plan contain annual average daily inventories of actual emissions for the 2012 base year, and projected inventories for the future 2019 RFP baseline year, the 2021 Moderate area attainment year, and the 2022 post-attainment RFP year.
33

The annual

average daily inventory is used to evaluate sources of emissions for attainment of the 2012 PM
2.5
NAAQS.

32
The 2016 PM
2.5
Plan generally uses “sulfur oxides” or “SO
X
” in reference to SO
2
as a precursor to the formation of PM
2.5
. We use SO
X
and SO
2
interchangeably throughout this notice.

33
The 2016 PM
2.5
Plan includes summer day inventories for ozone planning purposes, and inventories for Serious area planning purposes for

both the 2006 and 2012 PM
2.5
NAAQS. The 2016 PM
2.5
Plan therefore includes annual average and summer day inventories for all years between 2017 and 2031, except 2029. 2016 PM
2.5
Plan, Appendix III, Attachment A.

Future emissions forecasts are primarily based on demographic and economic growth projections provided by SCAG. Baseline inventories reflect all District control measures adopted by December 2015 and CARB rules adopted by November 2015. Growth factors used to project these baseline inventories are derived mainly from data obtained from SCAG.
34

34
Id. at III-2-6.

Each emissions inventory is divided into two source classifications: Stationary sources (
i.e.,
point sources and area sources) and mobile sources (
i.e.,
on-road and non-road sources of emissions). Point sources in the South Coast air basin that emit four tons per year (tpy) or more of PM, NO
X
, SO
X
, or VOC report annual emissions to the District. Point source emissions for the 2012 base year emissions inventory are generally based on reported data from facilities using the District's Annual Emissions Reporting program.
35

Area sources include smaller emission sources distributed across the nonattainment area. CARB and the District estimate emissions for about 400 area source categories using established inventory methods, including publicly available emission factors and activity information. Activity data may come from national survey data such as from the Energy Information Administration or from local sources such as the Southern California Gas Company, paint suppliers, and District databases. Emission factors can be based on a number of sources including source tests, compliance reports, and the EPA's AP-42.

35
Information about the SCAQMD's Annual Emissions Reporting program is available at
http://www.aqmd.gov/home/rules-compliance/compliance/annual-emission-reporting.

Emissions inventories are constantly being revised and improved. Between the finalization of the South Coast 2012 Air Quality Management Plan (“2012 AQMP”) and the development of the 2016 PM
2.5
Plan, the District improved and updated its emissions estimation methodologies for liquified petroleum gas combustion sources, natural gas combustion sources, Regional Clean Air Incentives Market (RECLAIM) NO
X
emissions sources (based on 2015 program amendments), livestock waste management operations, gasoline dispensing facilities, composting operations, oil and gas production, and architectural coatings.

On-road emissions inventories are calculated using CARB's EMFAC2014 model and the travel activity data provided by SCAG in “The 2016-2040 Regional Transportation Plan/Sustainable Communities Strategy.”
36

Re-entrained paved road dust emissions are calculated using the EPA's AP-42 road dust methodology.
37

36
SCAG's “The 2016-2040 Regional Transportation Plan/Sustainable Communities Strategy” is available at
http://scagrtpscs.net/Pages/FINAL2016RTPSCS.aspx.

37
CARB, Miscellaneous Process Methodology 7.9 Entrained Road Travel, Paved Road Dust, (Revised and updated, November 2016) available at
https://www.arb.ca.gov/ei/areasrc/fullpdf/full7-9_2016.pdf.

CARB provided emissions inventories for off-road equipment, including construction and mining equipment, industrial and commercial equipment, lawn and garden equipment, agricultural equipment, ocean-going vessels, commercial harbor craft, locomotives, cargo handling equipment, pleasure craft, and recreational vehicles. CARB uses several models to estimate emissions for more than one hundred off-road equipment categories.
38

Aircraft emissions are developed in conjunction with the airports in the region.

38
2016 PM
2.5
Plan, III-1-24.

Table 1 provides a summary of the District's 2012 base year annual average emissions estimates for direct PM
2.5
and all PM
2.5
precursors. These inventories provide the basis for the control measure analysis and the RFP and impracticability demonstrations in the 2016 PM
2.5
Plan. For a more detailed discussion of the inventories, see Appendix III of the Plan.

Table 1—South Coast 2012 Base Year Emissions
[Annual average, tons per day]

Direct PM
2.5

NO
X

SO
X

VOC
Ammonia

Stationary Sources
44
70
10
212
63

On-Road Mobile Sources
14
317
2
158
18

Off-Road Mobile Sources
8
153
6
100
0

Total
66
540
18
470
81

Source: 2016 PM
2.5
Plan, Table 3-2. Values may not be precise due to rounding.

Condensable Particulate Matter

The PM
2.5
SIP Requirements Rule states that “[t]he inventory shall include direct PM
2.5
emissions, separately reported PM
2.5
filterable and condensable emissions, and emissions of the scientific PM
2.5
precursors, including precursors that are not PM
2.5
plan precursors pursuant to a precursor demonstration under § 51.1006.”
39

On June 15, 2018, the SCAQMD submitted a technical supplement to the SIP containing emissions estimates for both condensable and filterable PM
2.5
emissions from specified sources of direct PM
2.5
in the South Coast area.
40

The supplement provides filterable and condensable emissions estimates, expressed as annual average PM
2.5
emissions, for all of the identified source categories for the 2012 base year, the 2019 RFP year, the 2021 Moderate area attainment year, and the 2022 RFP year, as well as subsequent years.
41

39
40 CFR 51.1008(a)(1)(iv).

40
Letter dated June 15, 2018, from Philip Fine, Deputy Executive Officer, SCAQMD, to Amy Zimpfer, Associate Director, EPA Region IX, Subject: “Condensable and Filterable Portions of PM
2.5
emissions in the 2016 AQMP.”

41
Id., Appendix A.

The 2016 PM
2.5
Plan relies on several SIP-approved rules that regulate direct PM emissions as part of the PM
2.5
control strategy, including Rule 445 (“Wood-Burning Devices”), as amended May 3, 2013; Rule 1138 (“Control of Emissions from Restaurant Operations”), adopted November 14, 1997; and Rule 1155 (“Particulate Matter (PM) Control Devices”), as amended May 2, 2014. As part of our action on any rules that regulate direct PM
2.5
emissions, we evaluate the emission limits in the rule to ensure that they appropriately address condensable PM, as required by 40 CFR 51.1008(a)(1)(iv). We note that the SIP-

approved version of Rule 1138 requires testing according to the District's protocol, which requires measurement of both condensable and filterable PM in accordance with SCAQMD Test Method 5.1.
42

We also note that the SIP-approved version of Rule 1155 requires measurement of both condensable and filterable PM in accordance with SCAQMD Test Methods 5.1, 5.2, or 5.3 as applicable.
43 44

42
Rule 1138 (adopted November 14, 1997), paragraph (c)(1) and (g), SCAQMD Protocol paragraph 3.1, and SCAQMD Protocol, “Determination of Particulate and Volatile Organic Compound Emissions from Restaurant Operations,
”
November 14, 1997 (available at
https://www.regulations.gov/contentStreamer?documentId=EPA-R09-OAR-2017-0490-0068&contentType=pdf
). The EPA approved Rule 1138 into the SIP on July 11, 2011 (66 FR 36170).

43
Rule 1155 (as amended May 2, 2014), paragraph (e)(6). The EPA approved Rule 1155 into the SIP on March 16, 2015 (80 FR 13495).

44
SCAQMD Test Method 5.1, “Determination of Particulate Matter Emissions from Stationary Sources Using a Wet Impingement Train,” March 1989; SCAQMD Test Method 5.2, “Determination of Particulate Matter Emissions from Stationary Sources Using Heated Probe and Filter,” March 1989; and SCAQMD Test Method 5.3, “Determination of Particulate Matter Emissions from Stationary Sources Using an in-Stack Filter,” October 2005.

3. The EPA's Evaluation and Proposed Action

The emissions inventories in the 2016 PM
2.5
Plan were made available to the public for comment and were subject to public hearing at both the District and State levels.
45

45
SCAQMD Board Resolution 17-2, 3 and CARB Resolution 17-8, 4.

The inventories in the 2016 PM
2.5
Plan are based on the most current and accurate information available to the State and District at the time the Plan and its inventories were being developed, including the latest EPA-approved version of California's mobile source emissions model that was available to the State and District at the time they were developing the Plan, EMFAC2014, and the EPA's most recent AP-42 methodology for paved road dust.
46

The inventories comprehensively address all source categories in the South Coast and were developed consistent with the EPA's regulations and inventory guidance. In accordance with 40 CFR 51.1008(a), the 2012 base year is one of the three years for which monitored data were used for designating the area, and it represents actual annual average emissions of all sources within the nonattainment area. Direct PM
2.5
and all PM
2.5
precursors are included in the inventories, and filterable and condensable direct PM
2.5
emissions are identified separately. For these reasons, we are proposing to approve the 2012 base year emissions inventory in the 2016 PM
2.5
Plan as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008. We are also proposing to find that the future year baseline inventories in the Plan satisfy the requirements of 40 CFR 51.1008(a)(2) and 51.1012(a)(2) and provide an adequate basis for the RACM, RFP, and impracticability demonstrations in the 2016 PM
2.5
Plan.
47

46
SCAG's on-road emissions inventory includes power take off (PTO) as part of the heavy-duty truck category, whereas CARB's motor vehicle emissions budgets (MVEB) includes PTO as a standalone vehicle category. See email dated July 9, 2019, from Nesamani Kalandiyur, CARB, to Karina O'Connor, EPA. As a result, SCAG's on-road emissions estimates used in the air quality modeling are slightly lower than CARB's MVEBs and the modeled air quality concentrations in the 2016 PM
2.5
Plan are biased slightly low. Thus, the modeled concentrations are conservative and consistent with the District's conclusion that attainment by the Moderate area attainment date of December 31, 2021 is impracticable.

47
The baseline emissions projections in the 2016 PM
2.5
Plan assume implementation of CARB's Zero Emissions Vehicle (ZEV) sales mandate and greenhouse gas (GHG) standards, based on the approved EMFAC2014 model and assumptions that were available at the time of the SIP's development. On September 27, 2019, the U.S. Department of Transportation and the EPA (the Agencies) issued a notice of final rulemaking for the
Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule Part One: One National Program
(SAFE I) that, among other things, withdrew the EPA's 2013 waiver of preemption of CARB's ZEV sales mandate and vehicle GHG standards. 84 FR 51310 (September 27, 2019). See also proposed SAFE rule at 83 FR 42986 (August 24, 2018). In response to SAFE I, CARB developed EMFAC off-model adjustment factors to account for anticipated changes in on-road emissions. On March 12, 2020, the EPA informed CARB that the EPA considers these adjustment factors to be acceptable for future use. See letter dated March 12, 2020 from Elizabeth J. Adams, EPA Region IX, to Steven Cliff, CARB. On April 30, 2020 (85 FR 24174), the Agencies issued a notice of final rulemaking titled:
The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule for Model Years 2021-2026 Passenger Cars and Light Trucks
(SAFE II), establishing the federal fuel economy and GHG vehicle emissions standards based on the August 2018 SAFE proposal. The effect of both SAFE final rules (SAFE I and SAFE II) on the on-road vehicle mix in the South Coast nonattainment area and on the resulting vehicular emissions is expected to be minimal during the timeframe addressed in this SIP revision. Therefore, we anticipate the SAFE final rules would not materially change the demonstration that it is impracticable for the South Coast 2012 PM
2.5
Moderate area to attain by the Moderate area attainment date of December 31, 2021.

B. PM
2.5
Precursors

1. Requirements for the Control of PM
2.5
Precursors

The provisions of subpart 4 of part D, title I of the CAA do not define the term “precursor” for purposes of PM
2.5
, nor do they explicitly require the control of any specifically identified PM precursor. The statutory definition of “air pollutant” in CAA section 302(g), however, provides that the term “includes any precursors to the formation of any air pollutant, to the extent the Administrator has identified such precursor or precursors for the particular purpose for which the term `air pollutant' is used.” The EPA has identified NO
X
, SO
2
, VOC, and ammonia as precursors to the formation of PM
2.5
. Accordingly, the attainment plan requirements of subpart 4 apply to emissions of all four precursor pollutants and direct PM
2.5
from all types of stationary, area, and mobile sources, except as otherwise provided in the Act (
e.g.,
in CAA section 189(e)).

Section 189(e) of the Act requires that the control requirements for major stationary sources of direct PM
10
(which includes PM
2.5
) also apply to major stationary sources of PM
10
precursors, except where the Administrator determines that such sources do not contribute significantly to PM
10
levels that exceed the standard in the area. Section 189(e) contains the only express exception to the control requirements under subpart 4 (
e.g.,
requirements for RACM, RACT, best available control measures (BACM) and best available control technology (BACT), most stringent measures (MSM), and new source review (NSR)) for sources of direct PM
2.5
and PM
2.5
precursor emissions. Although section 189(e) explicitly addresses only major stationary sources, the EPA interprets the Act as authorizing it also to determine, under appropriate circumstances, that regulation of specific PM
2.5
precursors from other source categories in a given nonattainment area is not necessary. For example, under the EPA's longstanding interpretation of the control requirements that apply to stationary and mobile sources of PM
10
precursors in the nonattainment area under CAA section 172(c)(1) and subpart 4,
48

a state may demonstrate in a SIP submission that control of a certain precursor pollutant is not necessary in light of its insignificant contribution to ambient PM
10
levels in the nonattainment area.
49

48
General Preamble, 13539-13542.

49
Courts have upheld this approach to the requirements of subpart 4 for PM
10
. See,
e.g., Assoc. of Irritated Residents
v.
EPA, et al.,
423 F.3d 989 (9th Cir. 2005).

Under the PM
2.5
SIP Requirements Rule, a state may elect to submit to the EPA a “comprehensive precursor demonstration” for a specific nonattainment area to show that emissions of a particular precursor from all existing sources located in the nonattainment area do not contribute

significantly to PM
2.5
levels that exceed the standard in the area.
50

If the EPA determines that the contribution of the precursor to PM
2.5
levels in the area is not significant and approves the demonstration, the state is not required to control emissions of the relevant precursor from existing sources in the attainment plan.
51

50
40 CFR 51.1006(a)(1).

51
Id.

We are evaluating the 2016 PM
2.5
Plan in accordance with the presumption embodied within subpart 4 that all PM
2.5
precursors must be addressed in the State's evaluation of potential control measures, unless the State adequately demonstrates that emissions of a particular precursor or precursors do not contribute significantly to ambient PM
2.5
levels that exceed the PM
2.5
NAAQS in the nonattainment area. In reviewing any determination by the State to exclude a PM
2.5
precursor from the required evaluation of potential control measures, we consider both the magnitude of the precursor's contribution to ambient PM
2.5
concentrations in the nonattainment area and the sensitivity of ambient PM
2.5
concentrations in the area to reductions in emissions of that precursor.

2. Control of PM
2.5
Precursors in the 2016 PM
2.5
Plan

The 2016 PM
2.5
Plan discusses the five primary pollutants that contribute to the mass of the ambient aerosol (
i.e.,
directly emitted PM
2.5
, NO
X
, SO
X
, VOC, and ammonia), and states that various combinations of reductions in these pollutants could all provide a path to clean air.
52

The Plan assesses and presents the relative value of each ton of precursor emission reductions, considering the resulting ambient improvements in PM
2.5
air quality expressed in micrograms per cubic meter.
53

As presented in the weight of evidence discussion, trends in PM
2.5
and NO
X
emissions suggest a direct response between lower emissions and improved air quality. The Community Multiscale Air Quality (CMAQ) model simulations in the 2016 PM
2.5
Plan provide a set of response factors for direct PM
2.5
, NO
X
, SO
X
, and VOCs, based on improvements to ambient PM
2.5
levels resulting from reductions of each pollutant. The contribution of ammonia emissions is embedded as a component of the NO
X
and SO
X
factors because ammonium nitrate and ammonium sulfate are the resultant particulate species formed in the atmosphere.

52
2016 PM
2.5
Plan, VI-F-1 and V-6-61.

53
Id. at VI-A-15.

The 2016 PM
2.5
Plan describes how reductions in NO
X
, SO
X
, VOC, and ammonia emissions contribute to attainment of the PM
2.5
standard in the South Coast area and contains the District's evaluation of available control measures for all four of these PM
2.5
precursor pollutants, in addition to direct PM
2.5
, consistent with the regulatory presumptions under subpart 4. The 2016 PM
2.5
Plan also contains a discussion of the control requirements applicable to major stationary sources under CAA section 189(e).
54

54
Id., Appendix VI-F. In a separate rulemaking to approve revisions to SCAQMD's NNSR program, the EPA determined that the control requirements applicable under the SCAQMD SIP to major stationary sources of direct PM
2.5
also apply to major stationary sources of NO
X
, SO
X
, and VOC, and that major stationary sources of ammonia do not contribute significantly to PM
2.5
levels that exceed the PM
2.5
standards in the area. (80 FR 24821, May 1, 2015). This rulemaking addressed the control requirements of CAA section 189(e) only for NNSR purposes and not for attainment planning purposes under subparts 1 and 4 of part D, title I of the Act.

3. The EPA's Evaluation and Proposed Action

Based on a review of the information provided in the 2016 PM
2.5
Plan and other information available to the EPA, we agree with the State's conclusion that all four chemical precursors to the formation of PM
2.5
must be regulated for purposes of attaining the 2012 PM
2.5
NAAQS in the South Coast area. We discuss the State's evaluation of potential control measures for direct PM
2.5
, NO
X
, SO
X
, VOC, and ammonia in section V.D.

C. Air Quality Modeling

1. Requirements for Air Quality Modeling

Section 189(a)(1)(B) of the CAA requires each state in which a Moderate area is located to submit a plan that includes a demonstration (including air quality modeling) either (i) that the plan will provide for attainment of the PM
2.5
NAAQS by the applicable attainment date, or (ii) that attainment by that date is impracticable. The 2016 PM
2.5
Plan includes a demonstration that attainment by the Moderate attainment date is impracticable.

The EPA's PM
2.5
modeling guidance
55

(“Modeling Guidance” and “Modeling Guidance Update”) recommends that a photochemical model, such as the Comprehensive Air Quality Model with Extensions (CAMx) or Community Multiscale Air Quality Model (CMAQ), be used to simulate a base case, with meteorological and emissions inputs reflecting a base case year, to replicate concentrations monitored in that year. The model application to the base year undergoes a performance evaluation to ensure that it satisfactorily corroborates the concentrations monitored in that year. The model may then be used to simulate emissions occurring in other years required for a plan, namely the base year (which may differ from the base case year) and future year.
56

The modeled response to the emission changes between those years is used to calculate relative response factors (RRFs) that are applied to the design value in the base year to estimate the projected design value in the future year for comparison against the NAAQS. Separate RRFs are estimated for each chemical species component of PM
2.5
, and for each quarter of the year, to reflect their differing responses to seasonal meteorological conditions and emissions. Because each species is handled separately, before applying an RRF, the base year design value must be speciated using available chemical species measurements—that is, each day's measured PM
2.5
design value must be split into its species components. The Modeling Guidance provides additional detail on the recommended approach.
57

55
Memorandum dated November 29, 2018, from Richard Wayland, Air Quality Assessment Division, Office of Air Quality Planning and Standards, EPA, to Regional Air Division Directors, EPA, Subject: “Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM
2.5
, and Regional Haze,” (“Modeling Guidance”), and Memorandum dated June 28, 2011 from Tyler Fox, Air Quality Modeling Group, OAQPS, EPA, to Regional Air Program Managers, EPA, Subject: “Update to the 24 Hour PM
2.5
NAAQS Modeled Attainment Test,” (“Modeling Guidance Update”).

56
In this section, we use the terms “base case,” “base year” or “baseline,” and “future year” as described in section 2.3 of the EPA's Modeling Guidance. The “base case” modeling simulates measured concentrations for a given time period, using emissions and meteorology for that same year. The modeling “base year” (which can be the same as the base case year) is the emissions starting point for the plan and for projections to the future year, both of which are modeled for the attainment demonstration. Modeling Guidance, 37-38. Note that CARB sometimes uses “base year” synonymously with “base case” and “reference year” instead of “base year.”

57
Modeling Guidance, section 4.4, “What is the Modeled Attainment Tests for the Annual Average PM
2.5
NAAQS.”

The EPA has not issued modeling guidance specific to impracticability demonstrations but believes that a state seeking to make such a demonstration generally should provide air quality modeling similar to that required for an attainment demonstration.
58

The main difference is that for an impracticability demonstration, the implementation of the SIP control strategy (including

RACM) does not result in attainment of the standard by the Moderate area attainment date.

58
81 FR 58010, 58048.

For an attainment demonstration, a thorough review of all modeling inputs and assumptions (including consistency with EPA guidance) is especially important because the modeling must ultimately support a conclusion that the plan (including its control strategy) will provide for timely attainment of the applicable NAAQS. In contrast, for an impracticability demonstration, the end point is a reclassification to Serious, which triggers the requirement for a new Serious area attainment plan with a new air quality modeling analysis, and a new control strategy.
59

Thus, the Serious area planning process would provide an opportunity to refine the modeling analysis and/or correct any technical shortcomings in the impracticability demonstration. Therefore, the burden of proof will generally be lower for an impracticability demonstration compared to an attainment demonstration.
60

59
CAA section 189(b)(1).

60
81 FR 58010, 58049.

2. Air Quality Modeling in the 2016 PM
2.5
Plan

Air quality modeling is discussed in Chapter 5 and Appendix V of the 2016 PM
2.5
Plan. A brief description of the modeling and our evaluation of it follows. More detailed information about the modeling in the Plan is available in section III of our technical support document (TSD) for this proposed action.
61

61
EPA, Region IX, Air Division, “Technical Support Document, Proposed Action on the South Coast Moderate Area State Implementation Plan and Proposed Reclassification as Serious Nonattainment for the 2012 PM
2.5
Standard,” April 2020.

Annual PM
2.5
Modeling Approach

The District conducted CMAQ
62

simulations for each day in the 2012 base year. It generated site- and species-specific RRFs for the ammonium ion, nitrate ion, sulfate ion, organic carbon, elemental carbon, sea salt, and a combined grouping of other primary PM
2.5
material for each future year simulation, and calculated future year design values by multiplying the species- and site-specific RRFs by the corresponding quarterly mean component concentration. The District summed the quarterly mean components to determine quarterly mean PM
2.5
concentrations, which it subsequently averaged to determine the annual design values. The future year design values reflect the weighted quarterly average concentration from the projections of five years of data. The District projected future year annual PM
2.5
design values for the 2021 Moderate area attainment year and the 2025 Serious area attainment year, for the 2012 PM
2.5
standard of 12 µg/m
3
.
63

62
CMAQ Version 5.0.2.

63
The District also projected future year annual PM
2.5
design values for 2023.

Future Air Quality

Simulations of 2021 baseline emissions (no additional controls) and 2021 control emissions were conducted to assess future annual PM
2.5
levels in the South Coast air basin. The 2021 baseline simulation used emission levels projected from the 2012 base year that reflect all adopted control measures to be implemented by December 31, 2021. The 2021 control simulation reflects the effects of the control strategy on future PM
2.5
design values. Simulations of both the 2021 baseline and 2021 control emissions indicate that the 2012 annual PM
2.5
standard will not be met in the South Coast in 2021, even when all controls for direct PM
2.5
and PM
2.5
precursors are implemented. The projected 2021 control scenario design value is 12.3 µg/m
3
at Mira Loma, which is typically the monitoring site that records the highest PM
2.5
levels in the South Coast air basin.

Table 2 shows future annual PM
2.5
air quality projections at the Mira Loma monitoring site and the four other PM
2.5
monitoring sites equipped with comprehensive particulate species characterization. Shown in the table are the base year design values for 2012 along with projections for 2021.

Table 2—Future Annual PM
2.5
Air Quality Projections at Selected Monitoring Sites in the South Coast Air Basin

[µg/m
3
]

Monitoring site location
2012
2021 Control

Anaheim
10.6
9.1

Fontana
12.6
10.4

Los Angeles
12.4
10.6

Mira Loma
14.9
12.3

Rubidoux
13.2
10.9

Source: 2016 PM
2.5
Plan, Table 5-5 and Table V-6-6.

3. The EPA's Evaluation and Conclusion

The EPA evaluated the District's choice of model for the impracticability demonstration and the extensive discussion in the Plan about modeling procedures, tests, and performance analyses. We find the District's analyses consistent with EPA guidance on modeling for PM
2.5
attainment planning purposes. Based on these reviews, we find that the modeling in the Plan is adequate for the purposes of supporting the RFP demonstration and the demonstration of impracticability in the 2016 PM
2.5
Plan.

D. Reasonably Available Control Measures and Control Strategy

1. Requirements for RACM/RACT and Control Strategies

The general subpart 1 attainment plan requirement for RACM/RACT is described in CAA section 172(c)(1), which requires that attainment plan submissions “provide for the implementation of all reasonably available control measures as expeditiously as practicable (including such reductions in emissions from existing sources in the area as may be obtained through the adoption, at a minimum, of reasonably available control technology)” and provide for attainment of the NAAQS.

The attainment planning requirements specific to PM
2.5
under subpart 4 likewise impose upon states with nonattainment areas classified as Moderate an obligation to develop attainment plans that require RACM/RACT on sources of direct PM
2.5
and all PM
2.5
plan precursors. CAA section 189(a)(1)(C) requires that Moderate area PM
2.5
SIPs contain provisions to assure that RACM/RACT are implemented no later than four years after designation of the area. The EPA reads CAA section 172(c)(1) and 189(a)(1)(C) together to require that attainment plans for Moderate nonattainment areas provide for the implementation of RACM/RACT for existing sources of PM
2.5
and those PM
2.5
precursors subject to control in the nonattainment area as expeditiously as practicable but no later than four years after designation.
64

64
This interpretation is consistent with guidance provided in the General Preamble, 13540.

The PM
2.5
SIP Requirements Rule defines RACM as “any technologically and economically feasible measure that can be implemented in whole or in part within 4 years after the effective date of designation of a PM
2.5
nonattainment area and that achieves permanent and enforceable reductions in direct PM
2.5
emissions and/or PM
2.5
plan precursor emissions from sources in the area. RACM includes reasonably available control technology (RACT).”
65

The EPA has historically defined RACT as the lowest emission limitation that a particular stationary source is capable of meeting by the application of control

technology (
e.g.,
devices, systems, process modifications, or other apparatus or techniques that reduce air pollution) that is reasonably available considering technological and economic feasibility.
66

65
81 FR 58010, 58035.

66
General Preamble, 13541, and 57 FR 18070, 18073-18074.

Under the PM
2.5
SIP Requirements Rule, those control measures that otherwise meet the definition of RACM but “can only be implemented in whole or in part during the period beginning 4 years after the effective date of designation of a nonattainment area and no later than the end of the sixth calendar year following the effective date of designation of the area” must be adopted and implemented as “additional reasonable measures.”
67

67
40 CFR 51.1000, 51.1009(a)(4)(i)(B), and 51.1009(a)(4)(ii)(B).

States must provide written justification in a SIP submission for eliminating potential control options from further review on the basis of technological or economic infeasibility.
68

An evaluation of technological feasibility may include consideration of factors such as a source's process and operating conditions, raw materials, physical plant layout, and non-air quality and energy impacts (
e.g.,
increased water pollution, waste disposal, and energy requirements).
69

An evaluation of economic feasibility may include consideration of factors such as cost per ton of pollution reduced (cost-effectiveness), capital costs, and operating and maintenance costs.
70

Absent other indications, the EPA presumes that it is reasonable for similar sources to bear similar costs of emission reductions. Economic feasibility of RACM/RACT is thus largely informed by evidence that other sources in a source category have in fact applied the control technology, process change, or measure in question in similar circumstances.
71

68
40 CFR 51.1009(a)(3).

69
40 CFR 51.1009(a)(3); see also 57 FR 18070, 18073-18074.

70
Id.

71
57 FR 18070, 18074.

Consistent with these requirements, SCAQMD must implement RACM, including RACT, for direct PM
2.5
emission sources no later than April 15, 2019, and must implement additional reasonable measures for these sources no later than December 31, 2021.

The CAA allows for approval of enforceable commitments that are limited in scope where circumstances exist that warrant the use of such commitments in place of adopted measures.
72

Specifically, section 110(a)(2)(A) of the CAA provides that each SIP “shall include enforceable emission limitations and other control measures, means or techniques . . . as well as schedules and timetables for compliance, as may be necessary or appropriate to meet the applicable requirements of the Act.” Section 172(c)(6) of the Act, which applies to nonattainment area SIPs, is virtually identical to section 110(a)(2)(A).
73

Commitments approved by the EPA under CAA section 110(k)(3) are enforceable by the EPA and citizens under CAA sections 113 and 304, respectively. Additionally, if a state fails to meet its commitments, the EPA may make a finding of failure to implement the SIP under CAA section 179(a)(4), which starts an 18-month period for the state to correct the non-implementation before mandatory sanctions are imposed.

72
In the past, the EPA has approved enforceable commitments and courts have enforced these actions against states that failed to comply with those commitments. See,
e.g., American Lung Ass'n of N.J.
v.
Kean,
670 F. Supp. 1285 (D.N.J. 1987), aff'd, 871 F.2d 319 (3rd Cir. 1989);
NRDC, Inc.
v.
N.Y. State Dept. of Env. Cons.,
668 F. Supp. 848 (S.D.N.Y. 1987);
Citizens for a Better Env't
v.
Deukmejian,
731 F. Supp. 1448, recon. granted in par, 746 F. Supp. 976 (N.D. Cal. 1990);
Coalition for Clean Air
v.
South Coast Air Quality Mgt. Dist.,
No. CV 97-6916-HLH, (C.D. Cal. Aug. 27, 1999).

73
The language in sections 110(a)(2)(A) and 172(c)(6) is quite broad, allowing a SIP to contain any enforceable “means or techniques” that the EPA determines are “necessary or appropriate” to meet CAA requirements, such that the area will attain as expeditiously as practicable, but no later than the designated date. Furthermore, the express allowance for “schedules and timetables” demonstrates that Congress understood that all required controls might not be in place when a SIP is approved.

Once the EPA determines that circumstances warrant consideration of an enforceable commitment to satisfy a CAA requirement, it considers three factors in determining whether to approve the enforceable commitment: (a) Does the commitment address a limited portion of the CAA requirement; (b) is the state capable of fulfilling its commitment; and (c) is the commitment for a reasonable and appropriate period of time.
74

74
The Fifth Circuit Court of Appeals upheld the EPA's interpretation of CAA sections 110(a)(2)(A) and 172(c)(6) and the Agency's use and application of the three-factor test in approving enforceable commitments in the 1-hour ozone SIP for Houston-Galveston.
BCCA Appeal Group et al.
v.
EPA et al.,
355 F.3d 817 (5th Cir. 2003). More recently, the Ninth Circuit Court of Appeals upheld the EPA's approval of enforceable commitments in ozone and PM
2.5
SIPs for the San Joaquin Valley, based on the same three factor test.
Committee for a Better Arvin, et al.
v.
EPA,
786 F.3d 1169 (9th Cir. 2015).

2. Control Strategy in the 2016 PM
2.5
Plan

For purposes of evaluating the 2016 PM
2.5
Plan, we have divided the measures relied on to satisfy the applicable control requirements into two categories: Baseline measures and control strategy measures.

As the term is used here, baseline measures are federal, State, and District rules and regulations adopted prior to December 2015 for District rules, and prior to November 2015 for CARB rules (
i.e.,
prior to the development of the 2016 PM
2.5
Plan) that continue to achieve emission reductions through the Moderate area attainment year of 2021 and beyond.
75

The Plan describes many of these measures in Chapter 4, Appendix III, Appendix IV-B, Appendix IV-C, and Appendix VI.
76

Reductions from these baseline measures are incorporated into the baseline inventory and reductions from the District measures in the plan are individually quantified in Appendix III, Table III-2-2B. According to the Plan, baseline measures provide most of the emission reductions projected to occur between the 2012 base year and the 2022 post-attainment milestone year.
77

75
These measures are typically rules that have compliance dates occuring after the adoption date of a plan and mobile source measures that achieve reductions as older engines are replaced through attrition (
e.g.,
through fleet turnover).

76
See also, email dated September 12, 2019 from Kalam Cheung, SCAQMD, to Ashley Graham, EPA Region IX, attaching spreadsheet entitled “Draft Rule Adoption since 2016 AQMP 20190809.xlsx.”

77
2016 PM
2.5
Plan, Chapter 4 and Appendix V.

Control strategy measures are the new rules, rule revisions, commitments, and other measures that provide the additional increment of emission reductions needed beyond the baseline measures to provide for attainment, to demonstrate RFP, to meet the RACM/RACT requirement, or to provide for contingency measures. Beyond the reductions from the Plan's baseline measures as discussed above, the remaining reductions needed for RFP and attainment
78

are to be achieved through the District's enforceable commitments to achieve emission reductions in the South Coast nonattainment area. The Plan identifies the control measures that are expected to achieve those emission reductions, several of which are identified as “additional reasonable measures” because they are to be implemented

after the RACM deadline (
i.e.,
after the four-year period following designation but before the Moderate area attainment date). Below we discuss the District's RACM/RACT evaluation, additional reasonable measures identified in the plan, and the District's commitments to achieve emission reductions through new control measures to attain the 2012 PM
2.5
NAAQS by the December 31, 2025 Serious area attainment date.

78
The 2016 PM
2.5
Plan contains a demonstration that attainment of the 2012 PM
2.5
NAAQS by the December 31, 2021 Moderate area attainment date is impracticable and identifies December 31, 2025 as the most expeditious date by which the South Coast area can attain this standard. 2016 PM
2.5
Plan, Chapter 5 and Appendix V.

a. RACM/RACT Analysis in the 2016 PM
2.5
Plan

The 2016 PM
2.5
Plan's RACM/RACT evaluation for direct PM
2.5
, NO
X
, SO
X
, VOC, and ammonia sources is presented in Appendix VI. The District, CARB, and SCAG, the local metropolitan planning organization (MPO), each undertook a process to identify and evaluate potential measures that could contribute to expeditious attainment of the 2012 PM
2.5
standard in the South Coast nonattainment area. We describe each of these processes below.

i. The District's RACM Analysis

The District's RACM demonstration for the 2012 PM
2.5
NAAQS focuses on stationary and area source controls and is described in Appendix VI-A of the 2016 PM
2.5
Plan.

In the years prior to the adoption of the 2016 PM
2.5
Plan, the District developed and implemented comprehensive plans (
e.g.,
the 2012 Air Quality Management Plan) to provide for attainment of the PM
2.5
and ozone NAAQS. These plans have resulted in the District's adoption of many new rules and amendments to existing rules for stationary and area sources. In addition, although the District does not have authority to directly regulate emissions from mobile sources, the District has implemented control strategies to indirectly reduce emissions from mobile sources. These regulations and strategies have yielded significant emission reductions from sources under the District's jurisdiction.

In the 2016 PM
2.5
Plan, the District conducted a multi-step process to identify additional candidate RACM measures that are technologically and economically feasible. As a first step in the RACM analysis, the District developed a detailed emissions inventory of the sources of direct PM
2.5
and PM
2.5
precursors. An up-to-date and comprehensive emissions inventory is essential to develop control measures that effectively reduce air pollution. Details on the methodology and development of the emissions inventory are discussed in Chapter 3 and Appendix III of the 2016 PM
2.5
Plan. A total of 75 major source categories are included in the base year emissions inventory.
79

79
2016 PM
2.5
Plan, Table VI-A-3.

Based on these inventories, the District identified several source categories as key emission sources in the South Coast nonattainment area for the 2012 PM
2.5
NAAQS, including consumer products, livestock wastes, and numerous mobile source categories.
80

For the key stationary source categories under SCAQMD's jurisdiction, the District compared existing control measures with requirements in federal and state regulations and guidance, as well as with analogous rules in other air districts to identify potential control measures. Furthermore, to demonstrate that the SCAQMD considered all additional candidate measures that are available and technologically and economically feasible, the District conducted the following seven-step analysis:

80
Id., Table VI-A-8.

(1) Held an Air Quality Technology Symposium to solicit new ideas for feasible control measures in the South Coast air basin;

(2) conducted a RACT analysis to identify SCAQMD rules that are less stringent than the EPA control technique guidelines (CTGs) or analogous rules in other air districts;

(3) reviewed EPA technical support documents for previously adopted/amended rules submitted for approval into the California SIP;

(4) reviewed control measures adopted during 2012-2015 in other areas (
i.e.,
Ventura County, San Francisco Bay Area, San Joaquin Valley, Sacramento Metropolitan, Dallas Fort-Worth, Houston-Galveston-Brazoria, New York, and New Jersey) to evaluate whether control technologies deemed available and cost-effective in those areas would be feasible for use in the South Coast air basin;

(5) reevaluated control measures that the District had found to be technologically or economically infeasible as part of the RACM analysis for the 2012 AQMP;

(6) reviewed the EPA's Menu of Control Measures (MCM);
81

and

81
EPA, Menu of Control Measures,

http://www3.epa.gov/ttn/naaqs/pdfs/MenuOfControlMeasures.pdf,
as of December 1, 2015.

(7) reviewed the EPA's March 2013
“
Strategies for Reducing Wood Smoke
”
guidance document to identify regulatory options for reducing residential wood smoke.

Based on its RACM/RACT evaluation for stationary and area sources under its jurisdiction as described above, the District found that its current rules and regulations are generally equivalent to, or more stringent than, those developed by other air districts with respect to emissions of PM
2.5
and PM
2.5
precursors.
82

The District identified a list of potential control measures for reducing emissions further,
83

and evaluated these potential additional control measures to determine whether implementation of the measures would be technologically and economically feasible in the South Coast. In addition, the District considered other available control options that can only be implemented after the four-year deadline for RACM/RACT, but before the end of the sixth calendar year following designation,
i.e.,
additional reasonable measures.

82
2016 PM
2.5
Plan, VI-A-36 to VI-A-37.

83
Id., Table VI-A-11.

The District identified four additional control measures with quantifiable emission reductions to be implemented for the purpose of meeting the 2012 PM
2.5
NAAQS. The Plan contains a commitment by the District to adopt and implement these or substitute measures as additional reasonable measures in 2020.
84

We discuss the District's commitment in further detail in section V.D.2.b.

84
SCAQMD, Governing Board Resolution No. 17-2 (March 3, 2017), 9, and 2016 PM
2.5
Plan, Table 4-7 and Table 4-8 (identifying BCM-04, BCM-10, CMB-02 and CMB-03 as new control measures to be implemented by 2020 for PM
2.5
purposes).

The District has also included new commitments in the 2016 PM
2.5
Plan to achieve specific amounts of emission reductions from NO
X
and ammonia sources in the South Coast area. Specifically, the District has committed to adopt and submit measures that will achieve 2.5 tons per day (tpd) of reductions in NO
X
emissions and 0.3 tpd of reductions in ammonia emissions by 2020, and 20.5 tpd of reductions in NO
X
emissions by 2022, as part of the control strategy for attaining the PM
2.5
NAAQS by 2025.
85

The District expects

to meet these emission reduction commitments by adopting new control measures and programs and strengthening existing control measures, such as those identified in Table 4-7 and Table 4-8 of the Plan and in a supplemental update to the control strategy submitted September 12, 2019 (“Control Strategy Updates”).
86

More information about the District's enforceable commitments and the specific control measures anticipated to meet them is included in section V.D.2.c of this proposed rule.

85
SCAQMD, Governing Board Resolution No. 17-2 (March 3, 2017), 9; 2016 PM
2.5
Plan, Table 4-8; and email dated September 12, 2019 from Kalam Cheung, SCAQMD, to Ashley Graham, EPA Region IX, attaching spreadsheet entitled “Draft Rule Adoption since 2016 AQMP 20190809.xlsx” (“Control Strategy Updates”). Table 4-8 of the Plan identifies 5.8 tpd of NO
X
reductions to be achieved by 2022 but is supplemented by the Control Strategy Updates, which identify 20.5 tpd of NO
X
reductions to be achieved by 2022 as part of the District's aggregate tonnage commitment. Control Strategy Updates, “Summary” tab (“South Coast AQMD Reasonable Further Progress for 2012 Annual PM
2.5
Standard”). Table 4-8 of the Plan also identifies 0.3 tpd ammonia reductions and 28 tpd NO
X
reductions to be achieved for purposes of attaining the PM
2.5
NAAQS by 2025 and 3.3 tpd PM
2.5
reductions to be achieved for contingency measure purposes in 2025.

86
Control Strategy Updates, “Summary” tab (“South Coast AQMD Reasonable Further Progress for 2012 Annual PM
2.5
Standard”).

We provide below an evaluation of several State and District measures for key stationary and area source categories. We provide a more detailed evaluation of the District's regulations in our TSD,
87

together with recommendations for future improvements to these rules.

87
EPA, Region IX, Air Division, “Technical Support Document, Proposed Action on the South Coast Moderate Area State Implementation Plan and Proposed Reclassification as Serious Nonattainment for the 2012 PM
2.5
Standard,” April 2020.

ii. State and District Measures for Stationary and Area Sources

Consumer Products

CARB and the SCAQMD both have well-established programs to regulate VOC emissions from consumer products used by both household and institutional consumers, including detergents; cleaning compounds; polishes; floor finishes; cosmetics; personal care products; home, lawn, and garden products; disinfectants; sanitizers; aerosol paints; and automotive specialty products. Specifically, CARB has adopted three regulations that establish VOC and reactivity limits for 129 consumer product categories.
88

The first regulation (Article 1) covers the categories of antiperspirants and deodorants. The second regulation (Article 2) covers numerous categories and is simply called the “General Consumer Products Regulation.” The third regulation (Article 3) covers categories of aerosol coatings. The EPA approved amendments to these regulations into the California SIP on October 17, 2014.
89

88
These regulations are codified in the California Code of Regulations, Title 17, Division 3, Chapter 1, Subchapter 8.5—Consumer Products; Article 2—Consumer Products.

89
79 FR 62346.

The SCAQMD also regulates certain categories of consumer products, including architectural coatings, wood products, solvents and degreasers, consumer paint thinners, and inks.
90

As an example, we discuss South Coast's implementation of Rule 1113 (“Architectural Coatings”) below.

90
See,
e.g.,
South Coast Rule 1107 (“Coating of Metal Parts and Products”), approved into the SIP on November 24, 2008 (73 FR 70883); South Coast Rule 1122 (“Solvent Degreasers”), approved into the SIP on February 8, 2006 (71 FR 6350); and South Coast Rule 1130 (“Graphic Arts”), approved into the SIP on July 14, 2015 (80 FR 40915).

Based on our evaluation of the information about these programs in the 2016 PM
2.5
Plan, we agree with the State's and District's conclusion that these SIP-approved regulations implement RACM for the control of VOCs from consumer products.

Architectural Coatings

SCAQMD Rule 1113 (“Architectural Coatings”), amended February 5, 2016, establishes VOC content limits for paints and other architectural coating products and establishes workplace standards for architectural coating operations. The EPA approved Rule 1113, as amended, into the California SIP on November 29, 2018.
91

91
83 FR 61326.

In the 2016 PM
2.5
Plan, the District compared the requirements of Rule 1113, as amended September 6, 2013,
92

to analogous requirements implemented in other California air districts between 2000 and 2015. The District's evaluation included the requirements of Sacramento Metropolitan Air Quality Management District's Rule 442, as amended September 24, 2015. Based on this evaluation, the District concluded that Rule 1113, as amended September 6, 2013, is generally equivalent to the requirements in other air districts.

92
The EPA approved Rule 1113, as amended June 3, 2011, into the SIP on March 26, 2013. 78 FR 18244. Since then, the EPA has approved a more stringent version of Rule 1113, as amended February 5, 2016, into the SIP. 83 FR 61326 (November 29, 2018).

The District's February 5, 2016 amendment to Rule 1113 strengthened the rule by eliminating its exemption for small containers. According to a SCAQMD staff report, the small container exemption represented one percent of sales and an estimated twenty percent of total VOC emissions.
93

According to this report, the 2016 rule revision was expected to achieve an estimated VOC reduction of 0.88 tpd by January 1, 2019. The EPA approved this amended rule into the California SIP on November 29, 2018.
94

93
SCAQMD Final Staff Report, “Proposed Amended Rule 1113—Architectural Coatings,” February 2016, 22.

94
83 FR 61326.

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan and additional information obtained during our review of the Plan, we agree with the SCAQMD's conclusion that Rule 1113 implements RACM for the control of VOCs from architectural coatings.

Confined Animal Facilities and Livestock Waste

SCAQMD Rule 1127 (“Emission Reductions from Livestock Waste”), adopted August 6, 2004, and Rule 223 (“Emission Reduction Permits for Large Confined Animal Facilities”), adopted June 2, 2006, together establish requirements to reduce emissions of ammonia, VOCs, and other pollutants emitted from confined animal facilities and related operations. The EPA approved Rule 1127 and Rule 223 into the California SIP on May 23, 2013 and July 13, 2015, respectively.
95

95
78 FR 30768 (May 23, 2013) and 80 FR 39966 (July 13, 2015).

Rule 1127 applies to dairy farms with 50 or more cows, heifers, and/or calves and to manure processing operations, such as composting operations and anaerobic digesters. The rule requires operators of dairy farms and manure processing operations to use specified best management practices to reduce pollutant emissions during the removal and disposal of manure from corrals, among other things. Rule 223 applies to large confined animal facilities (LCAFs) and prohibits owners/operators of such facilities from building, altering, replacing, or operating an LCAF without first obtaining a permit from the District. The permit application must include, among other things, an emissions mitigation plan that identifies the mitigation measures to be implemented at the facility. For each source category covered by the rule, owners/operators must implement a prescribed number of mitigation measures among a list of options or as approved by the District, CARB, and the EPA.

The District compared the key requirements of Rule 1127 and Rule 223 to analogous requirements implemented in other parts of California and in Idaho. Based on this evaluation, the District concludes that Rule 1127 and Rule 223 together establish requirements for confined animal facilities and related operations that are generally equivalent to the requirements in these other areas. The District also considered several additional control methods to further reduce ammonia emissions from livestock waste, including application of acidifiers (sodium bisulfate), dietary manipulation, feed additives, manure slurry injection, and microbial/manure additives. The 2016 PM
2.5
Plan contains a commitment by the District to adopt

an ammonia control measure for livestock waste in 2019.
96

The proposed measure is identified in the Plan as BCM-04.
97

96
SCAQMD, Governing Board Resolution No. 17-2 (March 3, 2017), 9 and 2016 PM
2.5
Plan, Table 4-7.

97
2016 PM
2.5
Plan, Table 4-7 and IV-A-202 to IV-A-209 (describing BCM-04).

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan, we agree with the SCAQMD's conclusion that Rule 1127 and Rule 223 together implement RACM for the control of ammonia and VOCs from confined animal facilities and related operations.

Residential Wood-Burning Devices

SCAQMD Rule 445 (“Wood-Burning Devices”), amended May 3, 2013, establishes requirements for the sale, operation, and installation of wood-burning devices within the South Coast air basin that are designed to reduce PM emissions from such devices. The EPA approved Rule 445, as amended, into the California SIP on September 26, 2013.
98

98
78 FR 59249.

Under Rule 445, persons who manufacture, sell, or install wood-burning devices, commercial firewood sellers, and property owners or tenants who operate wood-burning devices are subject to specific requirements concerning the types of wood-burning devices that may be manufactured, sold, or installed, the types of fuels that may be burned in such devices, and labeling requirements. Rule 445 also establishes a mandatory winter wood-burning curtailment whenever the Executive Officer declares that ambient PM
2.5
levels are forecasted to exceed 30 µg/m
3
at specified source receptor areas.
99

99
The District has committed to adopt and submit revisions to Rule 445 to expand the geographic scope of the mandatory wood-burning curtailment provisions and to lower the curtailment threshold if the EPA makes any of the findings listed in 40 CFR 51.1014(a). Letter dated March 3, 2020, from Michael Benjamin, CARB, to Amy Zimpfer, EPA (enclosing letter dated February 12, 2020, from Wayne Nastri, SCAQMD, to Richard Corey, CARB). For more detail on the District's commitment, see section V.H of this proposed rule (“Contingency Measures”).

The District compared the requirements of Rule 445 to several rules implemented elsewhere in California that are designed to limit PM emissions from residential wood-burning devices. Based on this review, the District concludes that Rule 445 is generally equivalent to these other rules. Rule 445 does not require the removal of old wood stoves upon resale of a home, as do rules implemented in several other areas, but it does contain a prohibition on the installation of any wood-burning device in new residential developments, except in developments where there is no existing infrastructure for natural gas service within 150 feet of the property line or those 3,000 or more feet above mean sea level. Several other air districts prohibit or limit the installation of non-certified wood-burning devices but allow for installation of EPA-certified devices in new developments.

The EPA approved Rule 445 as implementing BACM for the 2006 24-hour PM
2.5
NAAQS on February 12, 2019.
100

Since that time, at least two other California air districts have revised their wood-burning rules to incorporate more stringent requirements.
101

Given that these rules were amended well after both the date of CARB's submission of the Plan, April 27, 2017, and the statutory deadline for this plan submission, October 15, 2016,
102

we find it reasonable that the SCAQMD did not evaluate these additional control requirements as part of its RACM analysis in the 2016 PM
2.5
Plan. Full evaluation of the additional control requirements in these revised rules will, however, be required as part of the State/District's BACM demonstration for the 2012 PM
2.5
NAAQS, which will be due within 18 months after the effective date of a final rule reclassifying the South Coast area as Serious nonattainment for the 2012 PM
2.5
NAAQS.

100
84 FR 3305.

101
San Joaquin Valley Unified Air Pollution Control District Rule 4901, amended June 20, 2019, and Bay Area Air Quality Management District Rule 6-3, amended November 20, 2019.

102
Section 189(a)(2) of the CAA requires submission of Moderate area plans within 18 months after nonattainment designations. Because the EPA designated the South Coast as a nonattainment area for the 2012 PM
2.5
NAAQS effective April 15, 2015 (80 FR 2206), California was required to submit a Moderate area plan for this area by October 15, 2016.

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan, we agree with the SCAQMD's conclusion that Rule 445 implements RACM for the control of PM
2.5
from residential wood-burning devices.

Paved and Unpaved Roads and Livestock Operations

Rule 1186 (“PM
10
Emissions from Paved and Unpaved Roads, and Livestock Operations”), amended July 11, 2008, establishes requirements to reduce the entrainment of PM as a result of vehicular travel on paved and unpaved public roads and livestock operations. The EPA approved Rule 1186, as amended, into the California SIP on March 7, 2012.
103

103
77 FR 13495.

Under Rule 1186, owners and operators of paved roads with average daily vehicle trips exceeding certain thresholds must remove visible roadway accumulation within specified periods of time and provide curbing or paved shoulders of certain widths when constructing new or widened roads. Rule 1186 also requires local government agencies that own or maintain paved roads to procure only certified street sweeping equipment for routine street sweeping; establishes requirements for owners and operators of certain unpaved roads to pave, apply chemical stabilization, or install signs to reduce vehicular speeds; and requires owners and operators of livestock operations to cease hay grinding activities during certain times of day, if visible emissions extend more than 50 feet from a hay grinding source.

The District compared the key requirements of Rule 1186 to analogous requirements implemented in other parts of California and in Nevada. Based on this evaluation, the District concludes that Rule 1186 is generally equivalent to the requirements in these other areas. To further reduce PM
2.5
emissions in areas with high vehicular activity, the District also considered several additional control techniques, such as increasing the frequency of street sweeping with certified equipment and specifying the most effective track out prevention measures. The District concludes that an increase in the required frequency of street sweeping is not economically feasible at this time because most areas in the South Coast air basin already require regular street sweeping and a requirement to conduct more frequent street sweeping would achieve only minimal emission reductions.

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan, we agree with the SCAQMD's conclusion that Rule 1186 implements RACM for the control of PM
2.5
from paved and unpaved roads and livestock operations.

Commercial Charbroiling

SCAQMD Rule 1138 (“Control of Emissions from Restaurant Operations”), adopted November 14, 1997, establishes control requirements to reduce PM and VOC emissions from chain-driven charbroilers at commercial cooking operations. The rule does not apply to under-fired charbroilers (UFCs). The EPA approved Rule 1138 into the California SIP on July 11, 2001.
104

104
66 FR 36170.

Under Rule 1138, chain-driven charbroilers that cook 875 pounds of meat or more per week are required to be equipped and operated with a catalytic oxidizer control device, and the combination charbroiler/catalyst must be tested and certified by the Executive Officer to reduce PM and VOC emissions. The District compared the requirements of Rule 1138 to several rules implemented in other parts of California and in other states that are designed to limit PM and/or VOC emissions from commercial charbroilers. Based on its review of analogous regulations implemented in these other areas, the District concludes that Rule 1138 is generally equivalent to those regulations.

Several times over the past 20 years and most recently in 2009, the District considered amending Rule 1138 to regulate PM emissions from UFCs, but to date the District has not identified control measures for UFCs that are both technologically and economically feasible for implementation in the South Coast. Although the Bay Area Air Quality Management District (BAAQMD) and New York City Department of Environmental Protection (NYDEP) have adopted rules that require controls for UFCs, neither agency has yet confirmed that any regulated sources that are subject to its rules have successfully installed and operated certified UFC control technologies.
105

Staff at the BAAQMD recently noted that electrostatic precipitators have been installed in commercial kitchens in San Francisco and San Jose but that the BAAQMD has not yet enforced control requirements for UFCs because no control technologies have yet been certified.
106

The 2016 PM
2.5
Plan contains a commitment by the District to adopt a control measure that requires controls on UFCs by 2025.
107

The proposed measure is identified in the Plan as BCM-01.
108

105
Email dated July 11, 2019, from Stanley Tong, EPA Region IX, to Krishnan Balakrishnan, BAAQMD, Subject: “Underfired charbroiler updates” and email dated June 17, 2019, from Ronald Vaughn, NYDEP, to Stanley Tong, EPA Region IX, Subject: “RE New Charbroiler Registrations NYC.” See also 2016 PM
2.5
Plan, IV-A-186 to IV-A-190.

106
Email dated January 9, 2020, from Virginia Lau, BAAQMD, to Stanley Tong, EPA Region IX, Subject: “RE: Underfired charbroiler—Q: SJ discussion about BA rule.”

107
SCAQMD, Governing Board Resolution No. 17-2 (March 3, 2017), 9 and 2016 PM
2.5
Plan, Table 4-7.

108
2016 PM
2.5
Plan, Table 4-7 and IV-A-186 to IV-A-192 (describing BCM-01).

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan and additional information obtained during our review of the Plan, we agree with the SCAQMD's conclusion that Rule 1138 implements RACM for the control of PM
2.5
from commercial charbroilers.

Boilers, Steam Generators, and Process Heaters

SCAQMD Rule 1146 (“Emissions of NO
X
from Industrial, Institutional, and Commercial Boilers, Steam Generators, and Process Heaters”), Rule 1146.1 (“Emissions of NO
X
from Small Industrial, Institutional, and Commercial Boilers, Steam Generators, and Process Heaters”), and Rule 1146.2 (“Emissions of NO
X
from Large Water Heaters and Small Boilers and Process Heaters) establish NO
X
emission limits for boilers, steam generators, and process heaters. The EPA approved Rule 1146 and Rule 1146.1, as amended November 1, 2013, into the California SIP on September 25, 2014,
109

and approved Rule 1146.2, as amended May 5, 2006, into the California SIP on December 5, 2008.
110

109
79 FR 57442.

110
73 FR 74027.

Rule 1146 applies to boilers, steam generators, and process heating units with ratings of more than 5 million British thermal units per hour (mmbtu/hr); Rule 1146.1 applies to units with ratings ranging from 2 to 5 mmbtu/hr; and Rule 1146.2 applies to units with ratings less than 2 mmbtu/hr. Each rule sets NO
X
emission limits for different fuel types (
e.g.,
digester gas, landfill gas, refinery gas). Rule 1146 and Rule 1146.1 also establish CO emission limits.

The District compared the requirements of the SIP-approved versions of Rule 1146, Rule 1146.1, and Rule 1146.2 to several rules implemented elsewhere in California (
i.e.,
Sacramento, the San Joaquin Valley, and the San Francisco Bay Area) that limit NO
X
and/or CO emissions from boilers, steam generators, process heaters and found that the SCAQMD rules are generally as stringent as or more stringent than other California air district rules for this source category. As part of the EPA's rulemakings to approve these rules into the SIP, the EPA concluded that the rules meet CAA requirements for enforceability, RACT, and SIP revisions.
111

111
79 FR 57442 (September 25, 2014) and 73 FR 74027 (December 5, 2008).

SCAQMD amended Rule 1146, Rule 1146.1, and Rule 1146.2 on December 7, 2018, to initiate the transition of the NO
X
RECLAIM program to a command-and-control regulatory structure. Although these amended rules have not yet been approved into the California SIP, the rule amendments are estimated to achieve an additional 0.27 tpd of NO
X
emission reductions by January 1, 2023.
112

112
SCAQMD Final Staff Report, “Proposed Amended Rule 1146—Emissions of Oxides of Nitrogen from Industrial, Institutional, and Commercial Boilers, Steam Generators, and Process Heaters; Proposed Amended Rule 1146.1—Emissions of Oxides of Nitrogen from Small Industrial, Institutional, and Commercial Boilers, Steam Generators, and Process Heaters; Proposed Amended Rule 1146.2—Emissions of Oxides of Nitrogen from Large Water Heaters and Small Boilers and Process Heaters; and Proposed Rule 1100—Implementation Schedule for NOx Facilities,” December 2018, EX-2, available at
http://www.aqmd.gov/docs/default-source/Agendas/Governing-Board/2018/2018-dec7-028.pdf?sfvrsn=6.

Based on our evaluation of the information provided in the 2016 PM
2.5
Plan and additional information obtained during our review of the Plan, we agree with the SCAQMD's conclusion that Rule 1146, Rule 1146.1, and Rule 1146.2 implement RACM for the control of NO
X
from boilers, steam generators, and process heaters.

iii. State Measures for Mobile Sources

CARB's RACM analysis is contained in Attachment VI-A-3 (“California Mobile Source Control Program Best Available Control Measures/Reasonably Available Control Measures Assessment”) (“BACM/RACM assessment”) to Appendix VI-A of the 2016 PM
2.5
Plan.

CARB's BACM/RACM assessment provides a general description of CARB's existing mobile source programs. A more detailed description of CARB's mobile source control program, including a comprehensive table listing on- and off-road mobile source regulatory actions taken by CARB since 1985, is contained in Attachment VI-C-1 to Appendix VI-C of the 2016 PM
2.5
Plan. The BACM/RACM assessment contains CARB's evaluation of mobile source and other statewide control measures that reduce emissions of PM
2.5
and PM
2.5
precursors in California, including the South Coast air basin.

Mobile source categories for which CARB has primary responsibility for reducing emissions in California include most new and existing on- and off-road engines and vehicles and motor vehicle fuels. Given the need for significant emission reductions from mobile sources to meet the NAAQS in California nonattainment areas, CARB has established stringent control measures for on-road and off-road mobile sources and the fuels that power them.
113

California has unique authority

under CAA section 209 (subject to a waiver by the EPA) to adopt and implement new emission standards for many categories of on-road vehicles and engines, and new and in-use off-road vehicles and engines. The EPA has approved such mobile source regulations for which waiver authorizations have been issued as revisions to the California SIP.
114

113
California regulations use the term “off-road” to refer to “nonroad” vehicles and engines.

114
See,
e.g.,
81 FR 39424 (June 16, 2016), 82 FR 14446 (March 21, 2017), and 83 FR 23232 (May 18, 2018).

CARB's mobile source program extends beyond regulations that are subject to the waiver or authorization process set forth in CAA section 209 to include standards and other requirements to control emissions from in-use heavy-duty trucks and buses, gasoline and diesel fuel specifications, and many other types of mobile sources. Generally, these regulations have also been submitted and approved as revisions to the California SIP.
115

115
See,
e.g.,
the EPA's approval of standards and other requirements to control emissions from in-use heavy-duty diesel-powered trucks at 77 FR 20308 (April 4, 2012), revisions to the California on-road reformulated gasoline and diesel fuel regulations at 75 FR 26653 (May 12, 2010), and revisions to the California motor vehicle I/M program at 75 FR 38023 (July 1, 2010).

iv. Local Jurisdiction Transportation Control Measures

Transportation control measures (TCMs) are, in general, measures designed to reduce emissions from on-road motor vehicles through reductions in vehicle miles traveled (VMT) or traffic congestion. TCMs can reduce PM
2.5
emissions in both the on-road motor vehicle exhaust and paved road dust source categories by reducing VMT and vehicle trips. They can also reduce vehicle exhaust emissions by relieving congestion. EPA guidance states that where mobile sources contribute significantly to PM
2.5
violations, “the state must, at a minimum, address the transportation control measures listed in CAA section 108(f) to determine whether such measures are achievable in the area considering energy, environmental, and economic impacts and other costs.”
116

116
Addendum to General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” 59 FR 41998 (August 16, 1994) (hereafter “Addendum”), 42013.

Appendix IV-C, “Regional Transportation Strategy and Control Measures,” contains SCAG's RACM analysis for TCMs. Consistent with EPA guidance, SCAG addressed the TCMs listed in CAA section 108(f) following a four-step process: (1) SCAG described the process by which they and the applicable transportation agencies in the South Coast air basin identify, review, and make enforceable commitments to implement TCMs; (2) SCAG assembled and reviewed control measures implemented in other ozone nonattainment areas (both in California and in other states); (3) SCAG compared candidate measures with measures implemented in the South Coast air basin to date, as well as new TCMs in the current Plan; and (4) SCAG provided reasoned justification for any available measures that have yet to be implemented. Based on their review, SCAG determined that the TCMs currently being implemented in the South Coast air basin include all RACM and that none of the identified candidate measures are both technically and economically feasible and would advance the attainment date in the South Coast. Attachment B of Appendix IV-C of the Plan contains a complete listing of all candidate measures evaluated as potential RACM, including a description of each measure, an indication of whether the measure is currently being implemented in the SCAG region, and a reasoned justification for SCAG's rejection of any measures that it has not adopted.

b. Additional Reasonable Measures

As discussed above, the PM
2.5
SIP Requirements Rule defines control measures that otherwise meet the definition of RACM but can only be implemented during the period beginning four years after the effective date of designation but before the Moderate area attainment date as “additional reasonable measures.”
117

117
40 CFR 51.1000, 51.1009(a)(4)(i)(B), and 51.1009(a)(4)(ii)(B).

The 2016 PM
2.5
Plan identifies four cost effective and technologically feasible control measures to be implemented in the year 2020.
118

These measures are BCM-04, BCM-10, CMB-03, and CMB-02. Because each of these measures is to be implemented in 2020, after the April 15, 2019 deadline for implementation of RACM/RACT but before the Moderate area attainment date of December 31, 2021, the District identifies these measures as “additional reasonable measures” for purposes of providing progress towards attainment of the 2012 PM
2.5
NAAQS.
119

Details regarding the cost effectiveness analysis and the schedule for implementation of each of these four measures are provided in Chapter 4, Appendix IV-A, and Appendix IV-B of the 2016 PM
2.5
Plan.

118
2016 PM
2.5
Plan, Table 4-8.

119
Id., Table VI-A-13.

c. Enforceable Commitments

The 2016 PM
2.5
Plan includes commitments by the District to adopt and implement certain measures and to achieve specific emission reductions in the South Coast area for purposes of attaining the 2012 PM
2.5
NAAQS by 2025. Specifically, the SCAQMD has committed to (1) adopt, submit, and implement the control measures listed in Table 4-7 of the Plan by specified dates to achieve the total tonnages of emission reductions identified in Table 4-8 of the Plan, or substitute other measures as necessary to achieve those emission reductions, and (2) achieve the total tonnages of reductions of each pollutant by the dates specified in Table 4-8 of the Plan.
120

If the SCAQMD determines that a particular measure listed in Table 4-7 of the Plan is infeasible, in whole or in part, the SCAQMD's commitment is to substitute other measures that will achieve equivalent emission reductions in the same adoption or implementation timeframes.
121

The 2016 PM
2.5
Plan relies on these emission reduction commitments (also referred to as “aggregate tonnage commitments”) as part of the control strategy for meeting the 2022 RFP milestones in the Plan and attaining the 2012 PM
2.5
NAAQS by the December 31, 2025 Serious area attainment date.
122

120
SCAQMD Governing Board Resolution No. 17-2 (March 3, 2017), 9. The District clarified its aggregate tonnage commitments for the 2022 RFP milestone year in its Control Strategy Updates, “Summary” tab (“South Coast AQMD Reasonable Further Progress for 2012 Annual PM
2.5
Standard”).

121
2016 PM
2.5
Plan, Chapter 4, 4-53 and 4-54.

122
Id. at 4-53 to 4-54 and Table 4-8.

The District expects to meet its emission reduction commitments by adopting new control measures and programs and by strengthening existing control measures, as identified in Table 4-7 and Table 4-8 of the Plan. These new or revised control measures include rules to regulate appliances in commercial and residential applications, livestock wastes, non-refinery flares, greenwaste composting, and restaurant burners and residential cooking.

3. The EPA's Evaluation and Proposed Action

a. RACM/RACT and Additional Reasonable Measures

We have reviewed the District's determination in the 2016 PM
2.5
Plan that its stationary and area source control measures represent RACM for PM
2.5
and PM
2.5
precursors. In our review, we also considered our previous evaluations of the District's rules in

connection with our approval of the SCAQMD's RACT SIP demonstration for the 2008 ozone NAAQS.
123

Based on this review, we believe the District's rules provide for the implementation of RACM for stationary and area sources of PM
2.5
and PM
2.5
precursors.

123
82 FR 43850 (September 20, 2017).

With respect to mobile sources, CARB's current program addresses the full range of mobile sources in the South Coast through regulatory programs for both new and in-use vehicles. With respect to transportation controls, we find that SCAG has a well-established TCM development program in which TCMs are continuously identified, reviewed, and evaluated throughout the transportation planning process. Overall, we believe that the programs developed and administered by CARB and SCAG provide for the implementation of RACM for PM
2.5
and PM
2.5
precursors in the South Coast nonattainment area.

Finally, the 2016 PM
2.5
Plan contains enforceable commitments to adopt and implement a number of additional reasonable measures by 2020, for purposes of meeting the 2022 RFP milestones in the Plan and attaining the 2012 PM
2.5
NAAQS by the December 31, 2025 Serious area attainment date.

For all of these reasons, we propose to find that the 2016 PM
2.5
Plan provides for the implementation of RACM and additional reasonable measures for all sources of direct PM
2.5
and PM
2.5
precursors as expeditiously as practicable, for purposes of the 2012 PM
2.5
NAAQS in the South Coast area, in accordance with the requirements of CAA section 189(a)(1)(C) and 40 CFR 51.1009.

b. Enforceable Commitments

In addition, we are proposing to approve the District's enforceable commitments to adopt and implement certain measures by specific dates and to achieve specific tonnages of emission reductions from these or appropriate substitute measures, by 2022, as part of the control strategy and RFP demonstration in the 2016 PM
2.5
Plan. These commitments to adopt and implement control measures and to achieve emission reductions, in the aggregate, by specified dates satisfy the EPA's 3-factor test for approval of such enforceable commitments.

The 2016 PM
2.5
Plan provides for the majority of the emission reductions necessary for making progress towards attainment to be achieved from baseline measures. These reductions come from a combination of District, State, and federal stationary and mobile source measures.
124

Over the past four decades, the District has adopted or revised almost 100 prohibitory rules that limit emissions of direct PM, NO
X
, SO
2
, VOC, and ammonia from stationary sources. The vast majority of these rules are currently SIP-approved and as such, their emission reductions are fully creditable in attainment-related SIPs. California has also adopted standards for many categories of on- and off-road vehicles and engines as well as standards for gasoline and diesel fuels. The State's mobile source measures are discussed in Section V.D.2.a.iii of this proposed rule. The remaining reductions needed for attainment are to be achieved through the District's enforceable commitments to achieve emission reductions in the South Coast through the anticipated defined control measures listed in Table 4-7 and Table 4-8 of the Plan.

124
Federal measures include the EPA's national emission standards for heavy duty diesel trucks (66 FR 5001 (January 18, 2001)), certain new construction and farm equipment (Tier 2 and 3 non-road engines standards (63 FR 56968 (October 23, 1998), and Tier 4 diesel non-road engine standards (69 FR 38958 (June 29, 2004)), and locomotives (63 FR 18978 (April 16, 1998) and 73 FR 37096 (June 30, 2008)). States are allowed to rely on reductions from federal measures in attainment and RFP demonstrations and for other SIP purposes.

With respect to the 2016 PM
2.5
Plan, circumstances warrant the consideration of enforceable commitments as part of the control strategy and RFP demonstration for the South Coast nonattainment area. As discussed below, a majority of the emission reductions that are needed to demonstrate RFP in the South Coast nonattainment area come from rules and regulations that were adopted prior the submittal of the Plan in April 2017 (
i.e.,
baseline measures). As a result of these already-adopted State and District measures, most sources in the South Coast nonattainment area were already subject to stringent rules prior to the development of the Plan, leaving fewer and more technologically challenging opportunities to reduce emissions. In the 2016 PM
2.5
Plan, the District identified potential control measures that could achieve the additional emission reductions needed to demonstrate RFP toward attainment by the Serious area attainment date. However, the timeline needed to develop, adopt, and implement these measures went beyond the October 15, 2016 statutory deadline for submitting the Plan. The District has made progress in adopting measures to meet its commitments but has not yet completely fulfilled them. Given these circumstances, the 2016 PM
2.5
Plan's reliance on enforceable commitments is warranted. We now consider the three factors the EPA uses to determine whether the use of enforceable commitments in lieu of adopted measures satisfies CAA planning requirements.

i. Commitments Are a Limited Portion of Required Reductions

For the first factor, we look to see if the commitment addresses a limited portion of a statutory requirement, such as the amount of emission reductions needed to demonstrate RFP in a nonattainment area. As discussed in greater detail in section V.G, the Plan demonstrates RFP for the 2019 RFP milestone year and 2022 post-attainment milestone year for purposes of the 2012 PM
2.5
Moderate area plan. For the 2019 milestone year, the plan demonstrates that RFP is achieved by emission reductions from baseline measures alone, whereas the RFP demonstration for the 2022 milestone year relies on emission reductions from new control measures committed to in the 2016 PM
2.5
Plan.
125

As shown in Table 3, of the emission reductions needed to meet the 2022 RFP milestone for the 2012 PM
2.5
NAAQS in the South Coast nonattainment area, 7 tpd of NO
X
emission reductions need to be achieved by new or revised control strategy measures —that is, State and District baseline measures achieve all but 7 tpd of the NO
X
emission reductions necessary to meet the RFP milestone for 2022. This represents approximately 3 percent of the NO
X
reductions needed to meet the 2022 RFP milestone. Historically, the EPA has approved SIPs with enforceable commitments in the range of approximately 10 to 13 percent of the total reductions needed for attainment.
126

We find that the District's NO
X
commitment addresses a limited proportion of the required emission reductions.

125
2016 PM
2.5
Plan, Table VI-C-5A.

126
See,
e.g.,
our approvals of the SJV PM
10
plan at 69 FR 30005 (May 26, 2004), the SJV 1-hour ozone plan at 75 FR 10420 (March 8, 2010), the Houston-Galveston 1-hour ozone plan at 66 FR 57160 (November 14, 2001), the SJV PM
2.5
plan at 76 FR 69896 (November 9, 2011), and the South Coast PM
2.5
plan at 76 FR 69928 (November 9, 2011).

Table 3—Reductions Needed for RFP Remaining as Commitments Based on SIP-Creditable Measures

PM
2.5

NO
X

SO
X

VOC
Ammonia

A. 2012 baseline emissions level
66.4
540
18.4
470
81.1

B. 2022 RFP target level
64.6
283
17.6
367
74.4

C. Total reductions needed from 2012 baseline levels to demonstrate RFP (A-B)
1.8
257
0.8
103
6.7

D. 2022 RFP baseline emissions level
64
290
17
362
73

E. Reductions from baseline measures (A-D)
2.4
250
1.4
108
8.1

F. Reductions needed from new/revised control strategy measures (D-B)
0
7
0
0
0

G. Percent of reductions needed to meet RFP from new control measures (F/C)
0
2.7%
0
0
0

Data Source: 2016 PM
2.5
Plan, Table 3-4B and Table VI-C-5A.

ii. The State Is Capable of Fulfilling Its Commitment

For the second factor, we consider whether the District is capable of fulfilling its commitments.

The District has made significant progress in meeting its enforceable commitments for the 2022 post-attainment RFP milestone year. It has adopted numerous baseline measures that are projected to achieve additional reductions of NO
X
in future years as shown in Table 4. In addition to the measures discussed above, both CARB and the District have well-funded incentive grant programs to reduce emissions from the on- and off-road engine fleets. Reductions from these programs have yet to be quantified and/or credited in the RFP demonstration.

Table 4—SCAQMD Control Measure Updates Since the 2016 Air Quality Management Plan

Control measure
Rule

Adoption
date

Final
implementation
date(s)

NO
X

reduction
(tpd)

VOC
reduction
(tpd)

CMB-02
Rule 1111—“Natural-Gas-Fired, Fan-Type Central Furnaces”
* 3/2/2018
1/1/2046
0.017

CTS-01 (2012 AQMP)
Rule 1113—“Architectural Coatings”
2/5/2016
1/1/2019

0.88

CMB-03
Rule 1118.1—“Non-Refinery Flares”
1/4/2019
7/1/2024
0.2

CMB-01, CMB-05
Rule 1134—“Stationary Gas Turbines”
4/5/2019
12/31/2023
2.8

CMB-01, CMB-05
Rule 1135—“Electricity Generating Facilities”
11/2/2018
1/1/2024
1.8
0.014

CMB-01, CMB-05
Rule 1146, Rule 1146.1, Rule 1146.2—“Non-Refinery Boilers and Heaters”
12/7/2018
1/1/2023
0.27

CTS-01
Rule 1168—“Adhesive and Sealant Applications”
10/6/2017
2017, 2019, 2023

1.4

Source: Email dated September 12, 2019 from Kalam Cheung, SCAQMD, to Ashley Graham, EPA Region IX, attaching spreadsheet entitled “Draft Rule Adoption since 2016 AQMP 20190809.xlsx.”
* SCAQMD further amended Rule 1111 on July 6, 2018 and December 6, 2019.

Given the District's efforts to date and its continuing efforts to reduce emissions, we believe it is capable of meeting its enforceable commitments to achieve the reductions needed to meet its 2022 RFP milestones for the 2012 PM
2.5
NAAQS.

iii. The Commitment Is for a Reasonable and Appropriate Timeframe

For the third and last factor, we consider whether the commitment is for a reasonable and appropriate period of time.

In order to meet the commitments to adopt measures and reduce emissions to the levels needed to meet the area's 2022 RFP milestones for the 2012 PM
2.5
NAAQS in the South Coast nonattainment area, the 2016 PM
2.5
Plan includes ambitious rule development, adoption, and implementation schedules for a number of defined control measures. The District has committed to achieve 20.5 tpd of NO
X
emission reductions by 2022 through adoption and implementation of these defined measures or substitute measures that achieve equivalent emission reductions. We believe that these timeframes are appropriate given the technological and economic challenges associated with the control measures that will be needed to achieve these reductions and the State's and District's required procedures for development and adoption of these measures. In addition, these reductions are not needed to meet the earlier 2019 RFP milestones. Thus, the commitment is for a reasonable and appropriate period of time.

Based on our consideration of these three factors, we are proposing to approve the District's commitments to adopt and implement specific control measures on the schedule identified in Table 4-7 and Table 4-8 of the 2016 PM
2.5
Plan to the extent that these commitments have not yet been fulfilled, and to achieve specific emission reductions by 2022, as given in these tables and in the Control Strategy Updates.

E. Major Stationary Source Control Requirements Under CAA Section 189(e)

CAA section 189(e) specifically requires that the control requirements applicable to major stationary sources of direct PM
2.5
also apply to major stationary sources of PM
2.5
precursors, except where the Administrator determines that such sources do not contribute significantly to PM
2.5
levels that exceed the standards in the area.
127

The control requirements applicable to major stationary sources of direct PM
2.5
in a Moderate PM
2.5
nonattainment area include, at a minimum, the requirements of a NNSR permit program meeting the requirements of CAA sections 172(c)(5) and 189(a)(1)(A). In the PM
2.5
SIP Requirements Rule, we established a deadline for states to

submit NNSR plan revisions to implement the PM
2.5
NAAQS 18 months after an area is initially designated and classified as a Moderate nonattainment area.
128

127
General Preamble, 13539 and 13541-13542.

128
81 FR 58010, 58115.

California submitted NNSR SIP revisions for the South Coast to address the subpart 4 requirements for Moderate PM
2.5
nonattainment areas on December 29, 2014.
129

The EPA fully approved these SIP revisions on May 1, 2015.
130

California also submitted NNSR SIP revisions for the South Coast to address the subpart 4 requirements for Serious PM
2.5
nonattainment areas on May 8, 2017, and the EPA conditionally approved these SIP revisions on November 30, 2018.
131

The basis for the November 30, 2018 conditional approval was a commitment by CARB and the SCAQMD to submit a revised version of Rule 1325 by December 30, 2019. CARB submitted a revised version of Rule 1325 to the EPA on April 24, 2019, fulfilling this commitment.
132

Accordingly, in this action, the EPA is not addressing the NNSR control requirements that apply to major stationary sources of direct PM
2.5
and PM
2.5
precursors in the South Coast area under CAA section 189(e).

129
Letter dated December 29, 2014, from Richard W. Corey, Executive Officer, CARB, to Jared Blumenfeld, Regional Administrator, EPA Region 9.

130
80 FR 24821.

131
83 FR 61551.

132
Letter dated April 24, 2019, from Richard W. Corey, Executive Officer, CARB, to Mike Stoker, Regional Administrator, EPA Region 9.

F. Demonstra

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2020-12690. Public record. Not legal advice.
