Final Technical Support Document

and Response to Comments

Final Rulemaking Action

on the South Coast 2007 AQMP for PM2.5

and the South Coast Portions of the Revised 

2007 State Strategy

Air Division

U.S. EPA Region 9

September 30, 2011
EPA- Region 9 Page 2

For further information on this technical support document, please contact:

Wienke Tax

Office of Air Planning (AIR-2)

U.S. Environmental Protection Agency – Region 9

75 Hawthorne Street

San Francisco, California 94105

(415) 947-4192

tax.wienke@epa.gov

Documents referenced in this technical support document may be found in the docket for 

this rulemaking, docket number EPA-R09-OAR-2009-0366, which may be found at 

www.regulations.gov or at the address listed above.
i

Table of Contents

I. Introduction and Background

A. The National Ambient Air Quality Standards for Fine Particulate Matter (PM2.5)

1. The PM2.5 National Ambient Air Quality Standards 

a. Level and Form of the Standard

b. Health Effects 

c. Revisions to the 24-Hour PM2.5 Standard

2. Implementing the PM2.5 NAAQS

a. Designations

b. PM2.5 Planning Requirements

B. PM2.5 Air Quality in the South Coast

1. PM2.5 Levels in the South Coast 

2. Chemical Composition of PM2.5 in the South Coast

C. California Submittals Constituting the South Coast PM2.5 State Implementation Plan

D. Public Notice and Hearing Requirements for and Completeness Determinations on SIP 

Submittals

1. Public Notice and Public Hearing Requirements for SIP Submittals

2. Completeness Determinations on SIP Submittals

II. Evaluation of the South Coast 2007 AQMP for PM2.5

A. Emissions Inventories

1. Requirements for Emissions Inventories

2. Emissions Inventories in the South Coast 2007 AQMP

3. Proposed Actions on Emissions Inventories

4. Evaluation and Conclusion

B. Air Quality Modeling

1. Requirements for Air Quality Modeling

2. Overview of the Conceptual Description, Modeling Approach, and Modeling Protocol 

in the South Coast 2007 AQMP

3. Air Quality Model Selection

4. Episode Selection

5. Domain Size and Spatial Resolution

6. Initial and Boundary Conditions
ii

7. Meteorological Model

8. Air Quality Model Performance

9. Modeled Attainment Test

10. Weight of Evidence

11. Proposed Actions on Air Quality Modeling

12. Evaluation and Conclusion

C. Attainment Plan Precursors

1. Requirements for Control of PM2.5 Precursors

2. Identification of PM2.5 Attainment Plan Precursors in the South Coast 2007 AQMP

and EPA‘s Evaluation

3. Evaluation and Conclusion

D. Reasonably Available Control Measures/Reasonably Available Control Technology

1. Requirements for RACM/RACT

2. RACM/RACT Analysis in the South Coast 2007 AQMP

3. Proposed Actions on RACM/ RACT Analysis

4. Evaluation and Conclusion

E. Attainment Date Extension

1. Requirements for Attainment Date Extensions

2. Proposed Attainment Date in the South Coast 2007 AQMP

3. Proposed Actions on Attainment Date Extension

4. Evaluation and Conclusion

F. Adopted Control Strategy and Enforceable Commitments

1. Requirements for Control Strategy and Enforceable Commitments

2. Control Strategy in the South Coast 2007 AQMP and Revised 2007 State Strategy

3. Proposed Actions on Adopted Control Strategy and Enforceable Commitments

4. Evaluation and Conclusion

G. Attainment Demonstration

1. Requirements for Attainment Demonstrations

2. Attainment Demonstration in the South Coast 2007 AQMP

3. Proposed Actions on Attainment Demonstration

4. Evaluation and Conclusion

H. Reasonable Further Progress Demonstration

1. Requirements for Reasonable Further Progress Demonstrations

2. RFP Demonstration in the South Coast 2007 AQMP
iii

3. Proposed Actions on RFP Demonstration

4. Evaluation and Conclusion

I. Contingency Measures

1. Requirements for Contingency Measures

2. Contingency Measures in the South Coast 2007 AQMP

3. Proposed Actions on Contingency Measures

4. Evaluation and Conclusion

J. Adequacy of the Motor Vehicle Emissions Budgets in the South Coast 2007 AQMP

1. Requirements for Motor Vehicle Emissions Budgets

2. Motor Vehicle Emissions Budgets in the South Coast 2007 AQMP

3. Prior Proposed and Current Final Action on the Budgets

4. Action on Trading Mechanism

III. Response to Comments

Appendix A – CARB Rules and Measures

A. Complete List of State Measures

B. State Rules That Do Not Address Direct PM2.5 or PM2.5 Attainment Plan Precursors in the 

South Coast

C. State Fuel Measures

D. State On-Road Mobile Source Measures

E. State Consumer Product Measures

F. State Vapor Recovery Measures

G. Other State Measures

Appendix B –South Coast Rules
iv

Acronyms & Terms

μ: micron (one millionth)

AB: California Assembly Bill

AERR: Air Emissions Report Rule, 40 CFR part 51, subpart A

APCD: air pollution control district

AQMD: air quality management district

AQMP: air quality management plan

AQS: Air Quality Subsystem

ARB: California Air Resources Board (also CARB)

BAR: California Bureau of Automotive Repair

BARCT: best available retrofit control technology

BC: black carbon

CAA: Federal Clean Air Act as amended in 1990

CALMET: a diagnostic 3- dimensional meteorological model

CAMx: Comprehensive Air Quality Model with extensions

CARB: California Air Resources Board (also ARB)

CCR: California Code of Regulations

CEFS: California Emissions Forecasting and Planning Inventory System

CEIDARS: California Emissions Inventory Development and Reporting System

CERR: Consolidated Emissions Reporting Rule, 40 CFR part 51, subpart A

CFR: Code of Federal Regulations

CMAQ: Congestion Mitigation and Air Quality funds

CMAQ: Community Multiscale Air Quality [model]

CMB: chemical mass balance

CO: carbon monoxide

CPM: condensable particulate matter

CTG: Control Techniques Guidelines

CSBA: California Small Business Alliance

District: South Coast Air Quality Management District

DPR: California Department of Pesticide Regulation

EC: elemental carbon

EGU: electrical generating unit

EPA: United States Environmental Protection Agency

FDDA: Four Dimensional Data Assimilation

FEM: federal equivalent method

FHWA: Federal Highway Administration

Fine particulate matter: PM2.5

FMVCP: Federal motor vehicle control program

FR: Federal Register

FRM: federal reference method

FTA: Federal Transit Administration

ICE : internal combustion engine

km: kilometer

m: meter

m

3

: cubic meter
v

MATES: Multiple Air Toxics Exposure Study

MCR: mid-course review

MM5: Mesoscale model

MMPA: meteorological model performance analysis

MPO: metropolitan planning organization

MVEB: motor vehicle emissions budget 

NAAQS: national ambient air quality standard

NCEP: National Centers for Environmental Prediction

NH3: ammonia

NO2: nitrogen dioxide

NOx: oxides of nitrogen

NYQ: not yet quantified

O3: ozone

OC :organic carbon

OTAQ: EPA‘s Office of Transportation and Air Quality

PBL: planetary boundary layer

PM: particulate matter

PM10: particulate matter with a diameter of 10 μm or less, includes PM2.5

PM2.5: particulate matter with a diameter of 2.5 μm or less

RACM: reasonably available control measures

RACT: reasonably available control technology

RAMS: Regional Atmospheric Modeling System

RFP: reasonable further progress

RH: relative humidity

RMPA: Regional Model Performance Analysis

ROG: reactive organic gases, used interchangeably with ―VOC‖

RRF: relative response factor

RTIP: regional transportation improvement program

RTP: regional transportation plan

SC: South Coast

SCAQMD: South Coast Air Quality Management District

SCE: Southern California Edison

SCOS97: Southern California Ozone Study 1997

SIP: state implementation plan

SJV: San Joaquin Valley

SJVAPCD: San Joaquin Valley Air Pollution Control District

SMAT: Speciated Modeled Attainment Test

SO2: sulfur dioxide

SOx: oxides of sulfur

SSI: Size Selective Inlet

STMPRAG: Scientific, Technical, and Modeling Peer Review Advisory Group 

TCM: transportation control measures

tpd: tons per day

TSD: technical support document

UAM: Urban Airshed Model -

UAMAERO-LT: Urban Airshed Model
vi

UFP: ultrafine particle 

UTM: Universal transverse Mercator

VMT: vehicle miles traveled

VOC: volatile organic compounds

WOE: weight of evidence

WRAP: Western Regional Air Partnership 

WRF: Weather Research and Forecasting

WSPA: Western States Petroleum Association
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Technical Support Document

and Response to Comments, Final Rulemaking Action on the

South Coast 2007 AQMP for PM2.5 and the South Coast 

Portions of the Revised 2007 State Strategy

I. Introduction and Background

This document provides supporting information and analysis for EPA‘s final rulemaking 

actions on the South Coast Air Quality Management District‘s 2007 AQMP (adopted June 1, 

2007 and revised March 4, 2011) and the related portions of the California Air Resources 

Board‘s State Strategy for California’s 2007 State Implementation Plan (adopted with 

amendments on September 27, 2007, revised and updated on April 24, 2009 and April 28, 2011). 

EPA proposed action on these plans on November 22, 2010 (75 FR 71294) and an amended 

proposal on July 14, 2011 (76 FR 41562). This TSD updates the TSDs prepared in support of the 

November 22, 2010 and July 14, 2011 proposals.1

In this TSD, we also provide our responses to the comments received on the two 

proposals.

A. The National Ambient Air Quality Standards for Fine Particulate Matter 

(PM2.5)

1. The PM2.5 National Ambient Air Quality Standards

a. Level and Form of the Standard

On July 18, 1997, EPA established new national ambient air quality standards (NAAQS) 

for PM2.5. 62 FR 38652.2 The annual standards are set at a level of 15 micrograms per cubic 

meter (μ/m3), as determined by the 3-year average of annual mean PM2.5 concentrations. The 

 

1

―Technical Support Document for the Proposed Action on the South Coast 2007 AQMP for PM2.5 and the South 

Coast Portions of the Revised 2007 State Strategy,‖ Air Division, U.S. Environmental Protection Agency, Region 9, 

November 8, 2010, referred to as the ―2010 TSD‖ in this document. ―Technical Support Document for the Revised 

Proposed Action on the South Coast 2007 AQMP for PM2.5 and the South Coast Portions of the Revised 2007 State 

Strategy,‖ June, 2011, Air Division, U.S. Environmental Protection Agency, Region 9,referred to as the ―2011 TSD‖ 

in this document.

2

The original annual and daily standards for particulate matter generally less than or equal to 10 micrometers in 

diameter (also referred to as PM10) were established in 1987. In the 1997 PM NAAQS revision, EPA also revised 

the standards for PM10 but these revised PM10 standards were later vacated by the court, and the 1987 PM10

standards remained in effect. In the 2006 NAAQS revision, the 24-hour PM10 standards were retained but the 

annual standards were revoked. The South Coast nonattainment area is designated and classified as serious 

nonattainment for the PM10 NAAQS. See 40 CFR part 81.305.
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24-hour standards were set at a level of 65 μ/m3, as determined by the 3-year average of the 98th 

percentile of 24-hour concentrations. 40 CFR § 50.13. 

b. Health Effects 

EPA established air quality standards for PM2.5 based on evidence from numerous health 

studies demonstrating that serious health effects are associated with exposures to elevated levels 

of PM2.5. Epidemiological studies have shown statistically significant correlations between 

elevated PM2.5 levels and premature mortality. Other important effects associated with PM2.5

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, as well as new 

evidence for more subtle indicators of cardiovascular health. Individuals particularly sensitive to 

PM2.5 exposure include older adults, people with heart and lung disease, and children. See, EPA,

Air Quality Criteria for Particulate Matter, No. EPA/600/P–99/002aF and EPA/600/P–

99/002bF, October 2004. 

Attainment of the 1997 PM2.5 standards is estimated to lead to reductions in health 

impacts, including tens of thousands fewer premature deaths each year, thousands fewer hospital 

admissions and emergency room visits each year, hundreds of thousands fewer absences from 

work and school, and hundreds of thousands fewer respiratory illnesses in children annually. See 

72 FR 20586, 20587 (April 25, 2007).

c. Revisions to the 24-Hour PM2.5 Standard

On October 17, 2006, EPA completed another review of the NAAQS for PM. With 

regard to the primary standards, the 24-hour PM2.5 standards were strengthened to a level of 35 

μ/m3, based on the 3-year average of the 98th percentile of 24-hour concentrations. The annual 

standards remained unchanged. 71 FR 61144 (October 17, 2006). Attainment of the 2006 PM2.5

standards is estimated to lead to additional reductions in health impacts over the 1997 standard, 

including approximately 1,200 to 13,000 fewer premature deaths each year, 1,630 fewer hospital 

admissions and 1,200 fewer emergency room visits for asthma each year, 350,000 fewer 

absences from work and school, and 155,300 fewer respiratory illnesses in children annually. 72 

FR 20586, 20587. 

On November 13, 2009, EPA designated the South Coast, along with other areas in the 

Country, as nonattainment for the 2006 24-hour PM2.5 standard. 74 FR 58688. California is now 

required to submit a plan demonstrating attainment of this standard by December 14, 2012. The 

South Coast 2007 AQMP address only the 1997 24-hour PM2.5 standards of 65 μg/m3and annual 

standards of 15 μg/m3.

2. Implementing the PM2.5 NAAQS

a. Designations

The process for designating areas either attaining or not attaining following promulgation 

of a new or revised NAAQS is contained in CAA section 107(d)(1). Under this section, each 
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State Governor or Tribal leader has an opportunity to recommend air quality designations, 

including the appropriate boundaries for areas to EPA. Under CAA section 107, State and Tribal 

recommendations are due within one year of promulgation of a new or revised NAAQS, and 

EPA has up to three years after the promulgation of a new or revised NAAQS to designate areas 

for that NAAQS. In the case of the 1997 PM2.5 standards, however, Congress amended section 

107 to extend the schedule for EPA to initiate the designations process until 3 calendar years of 

air quality data, measured at Federal Reference Method monitors, were gathered. See section 

6102(c)(1)(d) of the Transportation Equity Act for the 21st Century. EPA and State air quality 

agencies initiated the monitoring process for the PM2.5 NAAQS in 1999 and deployed all air 

quality monitors by January 2001. 

By no later than 120 days prior to promulgating designations, EPA is required to notify 

States or Tribes of any intended modifications to their boundaries that EPA deems necessary. 

States and Tribes then have an opportunity to provide a demonstration as to why the proposed 

modifications suggested by EPA are inappropriate. Whether or not a State or Tribe provides a 

recommendation, EPA must promulgate the designation that it deems appropriate. 

In April 2003, EPA requested that California to submit its designation recommendations, 

based on ambient air quality data from 2001 to 2003, and supporting documentation to EPA by 

February 15, 2004. California submitted its recommendations on February 11, 2004. See Letter, 

Catherine Witherspoon, CARB, to Wayne Nastri, EPA-Region 9, February 11, 2004. On 

December 17, 2004, EPA issued final PM2.5 designations for areas violating the 1997 standards, 

including the South Coast air basin. They were published in the Federal Register on January 5, 

2005 (70 FR 944) and became effective on April 5, 2005. The designations are codified at 40 

CFR part 83, subpart C.

The nonattainment designation for an area starts the process whereby a State must 

develop an implementation plan that includes, among other things, a demonstration showing how 

it will attain the ambient standards by the attainment dates required in the CAA. Under section 

172(b), States have up to 3 years after EPA‘s final designations to submit their SIPs to EPA. The 

SIPs demonstrating attainment of the 1997 PM2.5 standards were due on April 5, 2008, 3 years 

after the effective date of the designations. 

b. PM2.5 Planning Requirements

To assist states in developing effective plans to address their PM2.5 nonattainment 

problem, EPA issued the ―Clean Air Fine Particulate Implementation Rule,‖ also known as the 

PM2.5 implementation rule. 72 FR 20586 (April 25, 2007), codified at 40 CFR part 51, subpart 

Z. We proposed this rule on November 1, 2005 at 70 FR 65984. EPA issued this rule in 

accordance with the statutory requirements of the CAA set forth in subpart 1 of Part D of Title 1, 

i.e., sections 171–179B.

The PM2.5 implementation rule covers most CAA requirements for PM2.5 State 

implementation plans. A list of these CAA requirements, the corresponding provision in the 

PM2.5 implementation plan and preamble are given in Table IA-1 below.
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Table IA-1

CAA Requirements for PM2.5 Attainment State Implementation Plans

CAA 

Section

PM2.5 Implementation Rule Description TSD Rule Preamble

172(a)(2)(A) §51.1004 20600 Attainment date and attainment 

date extensions

II.E.

172(b) §51.1002(a) 20599 SIP submittal date I.B.3.

172(c)(1) §51.1010 20609--20633

Reasonably available control 

measures (including reasonably 

available control technology)

II.D.

172(c)(1)

§ 51.1007(a) 20601-20602

Demonstration of expeditious

attainment

II.F.

172(c)(2) § 51.1009 20633-20640 Reasonable further progress II.H.

172(c)(3) § 51.1008 20647-20651 Emission inventory II.A.

172(c)(6) § 51.1007(b)

§ 51.1010(b)

20601-20602

20658-20660

Enforceable limitation limits, other 

control measures, means or 

techniques and schedules and 

timetables for compliance as 

necessary for attainment 

II.D. & 

F.

172(c)(7) § 51.1002(b) 20600 CAA section 110(a)(2) requirements

N/A

172(c)(9) § 51.1012 20642-20645

Contingency measures for failure to 

attain or make reasonable further 

progress

II.J.

302(g) § 51.1002(c) 20589-20597 PM2.5 precursors to be evaluated for control

II.C.

172(c)(1) § 51. 1007(b) 20629 Timing of emission reductions for attainment

II.D. & 

F.

176(c) 93.118(e) 20645-20646 Motor vehicle emissions budgets I.D.

172(c)(2) & 

(6)

§ 51.1011 20640 Mid-course review II.I.

110(a)(2)(K)

§ 51.1007(a), 

§ 51.112 and 

Appendix W

20605-20609

Air Quality Modeling II.F.

In June 2007, a petition to the EPA Administrator was filed on behalf of several public 

health and environmental groups requesting reconsideration of four provisions in the PM2.5

implementation rule. See EarthJustice, ―Petition for Reconsideration in the Matter of the Final 

Clean Air Fine Particulate Implementation Rule,‖ June 25, 2008. These provisions are:
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1. Presuming that compliance with the (now remanded) Clean Air Interstate Rule satisfies the 

NOx, and SO2 and RACT requirements for electric generating units (EGUs). 72 FR 20586 (April 

25, 2007), at 20623-20628. EPA granted the petition for this provision on April 25, 2011. Letter, 

Gina McCarthy, Assistant Administrator for Air and Radiation, EPA, to David Baron and Paul 

Cort, EarthJustice, April 25, 2011.

2. Allowing States to defer establishing emission limits for condensable PM until January 1, 

2011. 72 FR 20586 (April 25, 2007), at 20652 (codified at 40 CFR § 51.1002(c)). EPA denied

the petition for this provision on April 25, 2011because the deferral period had already lapsed. 

3. Revising the criteria for analyzing the economic feasibility of RACT from a presumption that 

a given source must bear a cost similar to other sources to a consideration of whether the cost of 

a measure is reasonable for the regulated entity to bear, in light of benefits. 72 FR 20586, at 

20619- 20620. EPA granted the petition for this provision on April 25, 2011. 

4. Allowing States to use emissions reductions from outside of the nonattainment area to 

demonstration RFP. 72 FR 20586, at 20636. EPA granted the petition for this provision on May 

13, 2010. Letter, Gina McCarthy, Assistant Administrator for Air and Radiation, EPA, to David 

Baron and Paul Cort, EarthJustice, May 13, 2010.

The disputed provisions of the PM2.5 implementation rule are, for the most part, not 

relevant to today‘s action because California did not rely on them in developing the PM2.5 plan 

for the South Coast nonattainment area. We address each of these provisions later in this TSD: 

the first three in section II.D. (RACM/RACT) and the fourth in section II.H. (RFP).

B. PM2.5 Air Quality in the South Coast

The South Coast PM2.5 nonattainment area is located in the southern part of California. It 

comprises portions of Los Angeles County, all of Orange County, and the urbanized portions of 

San Bernardino and Riverside Counties. It is home to almost 18 million people and is the 

nation‘s leading area for goods movement. See Figure IB-1 for a map of the South Coast 

nonattainment area and the major sources of air pollution in the nonattainment area. The local 

air district with primary responsibility for developing a plan to attain the PM2.5 NAAQS in this 

area is the South Coast Air Quality Management District (―SCAQMD‖ or ―District‖). For a 

complete description of the PM2.5 nonattainment area, please refer to 40 CFR part 81.305.

1. PM2.5 Levels in the South Coast

Annual PM2.5 levels in South Coast are still exceeding the standard with a design value of

16.8 μg/m3for the 2008-2010 period at the Mira Loma site.

3

 See EPA, Air Quality System, 

 

3

See EPA, Air Quality System Design Value Report dated April 21, 2011 in the docket for today‘s action. A design 

value is an ambient concentration calculated using a specific methodology from monitored air quality data and is 

used to compare an area‘s air quality to a NAAQS. The methodologies for calculating design values for the annual 

and 24-hour PM2.5 NAAQS are found in 40 CFR 50, Appendix N, Sections 1(c)(1) and 1(c)(2), respectively. This 
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Design Value Report, April 21, 2011. 24-hour PM2.5 levels in the South Coast are below the 

1997 standard of 65 ug/m3; the 2008-2010 design value is 41 ug/m3.

4

See Figures IB-2 and IB-3. 

Figure IB-4 is a map of the current monitoring system in the South Coast.

Since comprehensive monitoring began for PM2.5 in the South Coast in the late 1990s, the 

area has seen a significant decline in ambient levels, especially in the 2002-2010 time period. 

Data presented in Figures IB-2 and IB-3 have been validated. All data except 2010 data have 

been certified by SCAQMD. Data for all sites exceeds 75% annual completeness but four sites 

have at least one quarter with completeness less than 75% in 2010: Azusa, Pasadena, Big Bear, 

and Reseda. 

Figure IB-1. South Coast Nonattainment Area and Location of Major Sources of Air 

Pollution

and Location of Major Sources of Air Pollution

Figure IB-1

 

value is based on 2008 and 2009 data that are complete, validated, and certified by the District and on 2010 data that 

are complete and validated but not yet certified by the District. 

4

Ibid. This value is based on 2008 and 2009 data that are complete, validated, and certified by the District and on 

2010 data that are complete and validated but not yet certified by the District. 
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Figure IB-2
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Figure IB-3 
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Figure IB-4. Ambient PM2.5 Monitoring Locations In the South Coast Air 

Basin 

From http://www.aqmd.gov/tao/AQ-Reports/AQMonitoringNetworkPlan/AppendixA.pdf
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2. Chemical Composition of PM2.5 in the South Coast

PM2.5 in the air is a complex mixture of components. Common components include: 

nitrate (NO3); sulfate (SO4); ammonium; elemental carbon; a great variety of organic 

compounds; and inorganic material (including metals, dust, sea salt, and other trace elements) 

generally referred to as ―crustal‖ material, although it may contain material from other sources. 

―Primary‖ particles are emitted directly into the air as a solid or liquid particle (e.g., elemental 

carbon from diesel engines or fire activities, or condensable organic particles from gasoline 

engines). ―Secondary‖ particles (e.g., nitrate and sulfate) form in the atmosphere as a result of 

chemical reactions between precursor pollutants such as NOx, SO2, VOC, and ammonia. The 

South Coast 2007 AQMP includes an updated ammonia inventory.5 Understanding the

compounds that impact an area‘s PM2.5 problem is necessary in order to develop control 

strategies that are effective for attaining the 1997 PM2.5 NAAQS. 72 FR 20586, at 20586.

PM2.5 in the South Coast Air Basin is overwhelmingly formed as a secondary pollutant. 

(South Coast 2007 AQMP, page ES-9). Therefore, the South Coast 2007 AQMP relies on 

reducing precursors to PM2.5 and some directly-emitted PM2.5 rather than fugitive dust (PM10). In 

general, the organic carbon (OC) mass accounts for approximately 30 percent of the total mass at 

each station. Ammonium, sulfate and nitrates account for an approximate 45 percent of the total 

mass at each location. Rubidoux and Fontana are the most heavily impacted by nitrates. Sulfate 

is highest in the near coastal or ports of Los Angeles/Long Beach areas, particularly Wilmington 

and Long Beach. Elemental carbon (EC) and metals measurements were highest at Wilmington,

accounting for almost 24 percent of the mass when combined. All sites observed measurable 

concentrations of sodium and chloride ions reflecting the influence of the marine air as it is 

transported inland. Figure IB-5 shows the annual distribution of PM2.5 species in the South Coast 

PM2.5 nonattainment area

 

5

 South Coast 2007 AQMP, Appendix III, page III-1-16, and electronic mail, Kathy Hsiao, SCAQMD, to Wienke 

Tax, EPA Region 9, dated October 29, 2010.
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Figure IB-5: MATES-III 2005 Annual Distribution of PM2.5 Species (μg/m3)6

C. California Submittals Constituting the South Coast PM2.5 State 

Implementation Plan 

Six submittals or parts of submittals comprise the South Coast PM2.5 attainment plan:

1. Final 2007 Air Quality Management Plan, SCAQMD, adopted June 1, 2007, submitted 

with the adopting resolutions and other supporting documentation by CARB on 

November 28, 2007. See South Coast Air Quality Management District Governing 

Board Resolution 07-9; CARB Resolution No. 07-41, September 27, 2007; and letter,

James N. Goldstene, Executive Officer, CARB to Wayne Nastri, Regional Administrator, 

EPA Region 9, November 28, 2007 with enclosures. This document will be referenced in 

this TSD and the Federal Register final rule as the ―2007 AQMP‖ and the ―South Coast

2007 AQMP‖. 

2. Proposed State Strategy for California’s 2007 State Implementation Plan, adopted 

September 27, 2007, submitted with the adopting resolution and other supporting 

documentation by CARB on November 16, 2007. See CARB Resolution No. 07-28, 

September 27, 2007 and letter, James N. Goldstene, Executive Officer, CARB, to Wayne 

Nastri, Regional Administrator, EPA Region 9, November 16, 2007, with enclosures.

This document will be referenced in this TSD and the Federal Register final rule as the 

―2007 State Strategy‖. 

3. Status Report on the State Strategy for California’s 2007 State Implementation Plan 

(SIP) and Proposed Revisions to the SIP Reflecting Implementation of the 2007 State 

Strategy, adopted April 24, 2009, submitted with the adopting resolution and other 

supporting documentation by CARB on August 12, 2009. See CARB Resolution No. 09-

34, April 24, 2009 and letter, James N. Goldstene, Executive Officer, CARB, to Laura 

 

6

South Coast 2007 AQMP, Appendix V, p. V-2-4.
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Yoshii, Acting Regional Administrator, EPA Region 9, August 12, 2009 with enclosures. 

This document will be referenced in this TSD and the Federal Register final rule as the 

―revised 2007 State Strategy‖.7

4. Progress Report on Implementation of PM2.5 State Implementation Plans (SIP) for the 

South Coast and San Joaquin Valley Air Basins and Proposed SIP Revisions, adopted on 

April 28, 2011 by CARB, submitted with the adopting resolution and other supporting 

documentation by CARB on May 18, 2011.

8

See CARB Board Resolution 11-24,

April 28, 2011 and letter, James N. Goldstene, Executive Officer, CARB, to Jared 

Blumenfeld, Regional Administrator, EPA Region 9, May 18, 2011 with enclosures. This 

document will be referenced in this TSD and the Federal Register final rule as the 2011 

Progress Report.

5. Revisions to the 2007 PM2.5 and Ozone State Implementation Plans for the South Coast 

Air Basin and Coachella Valley (SIP Revisions), adopted on March 4, 2011 by the 

SCAQMD Governing Board and approved by the CARB Board on April 28, 2011 and 

submitted on May 19, 2011. This SIP revision includes an update on District rule 

implementation and commitments provided by SCAQMD for the 2007 AQMP as well as 

a backstop of 1 tpd of NOx for the federal assignment. This SIP revision was included as 

Appendix F in the 2011 Progress Report and will be referred to as such.

6. 8-Hour Ozone State Implementation Plan Revisions and Technical Revisions to the 

PM2.5 State Implementation Plan Transportation Conformity Budgets for the South 

Coast and San Joaquin Valley Air Basins, June 20, 2011, with Appendices. Adopted by 

the CARB Board on July 21, 2011 and submitted on July 29, 2011.9(2011 Ozone SIP 

Revision) We are only acting on the revisions to the PM2.5 SIP transportation budgets 

from that submittal here. We will act on the ozone-related provisions of this SIP 

submittal as part of our final action on the South Coast 2007 8-Hour Ozone SIP. We 

proposed to approve these ozone-related provisions on September 16, 2011; see 76 FR 

57872.

Future references in this TSD and the Federal Register notice of final rulemaking to the 

2007 State Strategy will be to the Strategy as revised in 2009 and 2011, and the South Coast 

AQMP as revised in 2011, respectively, unless explicitly noted otherwise. We will also refer to 

the 2007 State Strategy as revised in 2009 and 2011 as the revised 2007 State Strategy.

In addition to these plan submittals, the District and CARB have provided additional 

information on the implementation status of the Plan‘s control strategy as well as supplemental 

 

7 Only pages 11-27 of the 2009 State Strategy Status Report are submitted as a SIP revision. The balance of the 

report is for informational purposes only. See Attachment A to the CARB Resolution, No. 09-34.

8

 Only Appendices B, C, and D of the 2011 Progress Report are submitted as a SIP revision. The balance of the 

report is for informational purposes only. See letter, James Goldstene, Executive Officer, CARB, to Jared 

Blumenfeld, Regional Administrator, EPA Region 9, dated May 18, 2011.

9 Only Appendix A of the 2011 Ozone SIP Revision is submitted as a SIP revision. The balance of the report is for 

informational purposes only. See Attachment A, CARB Resolution No. 11-22.
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documentation of the Plan‘s technical background and further information supporting the 2011 

Progress Report. This additional information was transmitted in a letter from Lynn Terry, Deputy 

Executive Officer, CARB, to Elizabeth Adams, Deputy Director, Air Division, USEPA Region 

9, on May 18, 2011 (CARB Progress Report Supplement).

Finally, both CARB and the District have adopted and submitted numerous rules that 

reduce emissions in the South Coast nonattainment area and contribute to progress in meeting the 

PM2.5 NAAQS in the area. See Appendices A and B of this TSD. 

D. Public Notice and Hearing Requirements for and Completeness 

Determinations on SIP Submittals 

1. Public Notice and Public Hearing Requirements for SIP Submittals

CAA sections 110(a) and (l) require a State to provide reasonable public notice and 

hearing prior to the adoption and submittal of a SIP or SIP revision. Thus, every SIP submittal

should include evidence that adequate public notice was given and a public hearing was held 

consistent with EPA‘s implementing regulations in 40 CFR § 51.102.

Both the District and CARB have satisfied applicable statutory and regulatory 

requirements for reasonable public notice and hearing prior to adoption and submittal of the 

South Coast 2007 AQMP and the 2007 State Strategy. The District conducted public workshops, 

provided public comment periods, and held a public hearing prior to the adoption of the Plan on 

June 1, 2007. Documentation accompanying the AQMP describes a public and agency outreach 

effort. See, e.g., the SCAQMD‘s Response to Comments on the Draft 2007 Air Quality 

Management Plan (February 2007), submitted by CARB on November 28, 2007 as enclosure IE, describing nine regional workshops held from October 24 through December 6, 2006 to 

discuss the draft 2007 Air Quality Management Plan (AQMP) released on October 10, 2006. The 

sequence of public meetings held to discuss the elements of the draft State Strategy for 

California‘s 2007 SIP (State Strategy) is described in the CARB staff report developed for the 

CARB Board‘s consideration prior to adoption of the State Strategy. CARB also provide the 

required public notice and opportunity for public comment prior to its September 27, 2007 public 

hearing on the South Coast 2007 AQMP. See CARB, Notice of Public Meeting to Consider 

Approval of the 2007 Air Quality Management Plan for Attaining the Federal 8-hour Ozone and 

PM2.5 Standards in the South Coast Air Basin and the Coachella Valley. See 

http://www.arb.ca.gov/board/ma/2007/ma092707.htm and 

http://www.arb.ca.gov/regact/nonreg/scsip07.pdf.

CARB conducted public workshops, provided public comment periods, and held a public 

hearing prior to its adoption of the 2007 State Strategy on September 27, 2007. See CARB, 

Notice of Public Meeting to Consider Approval of the Proposed State Strategy for California‘s 

State Implementation Plan (SIP) for the Federal 8-Hour Ozone and PM2.5 Standards, May 7, 

2007 and CARB Resolution No. 07-28, September 27, 2007.

CARB provided the required public notice, opportunity for public comment, and public 

hearing prior to its April 24, 2009 adoption of revisions to the Strategy. See CARB, Notice of 
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Public Hearing to Consider a Status Report on the State Strategy for California‘s 2007 State 

Implementation Plan and Consider Approval of a Proposed Revision to the State Implementation 

Plan Reflecting Implementation of the 2007 State Strategy, March 24, 2009 and CARB

Resolution No. 09-34, April 24, 2009.

CARB provided the required public notice, opportunity for public comment, and public 

hearing prior to its adoption of the 2011 Progress Report on April 28, 2011. See CARB, Notice 

of Public Hearing to Consider the Approval of a Progress Report and Proposed State 

Implementation Plan Revisions for PM2.5, March 29, 2011 and CARB Resolution No. 11-24,

April 28, 2011.

2. Completeness Determinations on SIP Submittals 

CAA section 110(k)(1)(B) requires EPA to determine whether a SIP submittal is 

complete within 60 days of receipt. This section also provides that any plan that we have not 

affirmatively determined to be complete or incomplete will become complete by operation of 

law six months after the day of submittal by operation of law. A completeness review allows us 

to determine if the submittal includes all the necessary items and information we need to act on 

it. 

 

We make completeness determinations using criteria we have established in 40 CFR part 

51, Appendix V. These criteria fall into two categories: administrative information and 

technical support information. The administrative information provides documentation that the 

State has followed basic administrative procedures during the SIP-adoption process and thus we 

have a legally-adopted SIP revision in front of us. The technical support information provides us 

the information we need to determine the impact of the proposed revision on attainment and 

maintenance of the air quality standards. 

We notify a state of our completeness determination by letter unless the submittal 

become complete by operation of law. A finding of completeness does not approve the submittal 

as part of the SIP nor does it indicate that the submittal is approvable. It does start the 12 month 

clock we have to act on the SIP submittal. See CAA section 110(k)(2). 

The November 28, 2007 submittal of the South Coast 2007 AQMP became complete by 

operation of law on May 28, 2008. The November 16, 2007 submittal of the 2007 State Strategy 

and the August 12, 2009 submittal of the 2009 revisions to the State Strategy became complete 

by operation of law on May 16, 2008 and February 12, 2010, respectively. We found the May 

18, 2011 submittal complete on June 13, 2011. See Letter, Deborah Jordan, Air Division 

Director, US EPA Region 9, to James Goldstene, Executive Officer, CARB, dated June 13, 

2011. We found CARB ̳s 2011 Ozone SIP Revision submittal of July 29, 2011 complete on 

August 23, 2011. See Letter, Deborah Jordan, Air Division Director, US EPA Region 9, to James 

Goldstene, Executive Officer, CARB, dated August 23, 2011.
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II. Evaluation of the South Coast 2007 AQMP for PM2.5
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A. Emissions Inventories

1. Requirements for Emissions Inventories

CAA section 172(c)(3) requires states to submit a plan provision that includes a 

―comprehensive, accurate, current inventory of actual emissions from all sources of the relevant 

pollutant.‖ Pursuant to this section, the PM2.5 implementation rule requires State to submit, 

within three years of the designation of one of its areas as nonattainment, statewide emissions

inventories for direct PM2.5 emissions and emissions of PM2.5 precursors. These inventories 

should meet the data requirements of EPA‘s Consolidated Emissions Reporting Rule (―CERR,‖ 

codified at 40 CFR part 51 subpart A). § 51.1008(a)(1).

10 Direct PM2.5 includes condensable 

PM. §51.1000 ―Direct PM2.5‖. PM2.5 precursors are NOX, SO2, VOCs, and ammonia. Id. The 

state must report inventories for each, even if it has determined that control of any of these 

precursors is not necessary for attainment. Id. and 72 FR 20586, at 20648. 

The PM2.5 implementation rule also requires states to submit a baseline emission 

inventory as part of the attainment and RFP demonstrations in their PM2.5 attainment plans. The 

base year for this inventory should be calendar year 2002 or other suitable year for areas initially 

designated nonattainment for the PM2.5 in 2004-2005. § 51.1008(b). The baseline inventory 

should be appropriate for the geographical area addressed by the PM2.5 attainment plan and 

consistent with applicable EPA guidance. 72 FR 20586 (April 25, 2007), at 20648. States are 

also required to submit any additional emission inventory information needed to support its 

attainment and RFP demonstrations. § 51.1008(a)(2).

EPA has issued the ―Emissions Inventory Guidance for Implementation of Ozone and 

Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze 

Regulations,‖ EPA–454/ R–99–006, November 2005 (available at: http://www.epa.gov/ttn/

chief/eidocs/eiguid/index.html). EPA developed this guidance document to complement the 

CERR and to provide specific guidance on how to develop emissions inventories for 8-hour 

ozone, PM2.5, and regional haze SIPs. 

The emissions inventories required under the PM2.5 implementation rule (as opposed to 

the CERR) are SIP provisions that must be approved by EPA under CAA section 110(k) and are

subject to public hearing requirements pursuant to section 110(a)(2). States should include in 

their SIP submittals documentation explaining how the emissions data were calculated. In 

estimating mobile source emissions, States should use the latest emissions models and planning 

assumptions available at the time the SIP is developed. 72 FR 20586, at 20647. For California, 

the latest emissions model means the most recently EPA approved version of EMFAC. 

Currently, this is EMFAC2007. See 73 FR 3464 (January 18, 2008).

 

10In late 2008, EPA promulgated the Air Emissions Reporting Rule (AERR) at 73 FR 76539 (December 17, 2008). 

The AERR updated the CERR reporting requirements by consolidating and harmonizing new emissions reporting 

requirements with pre-existing sets of reporting requirements under the NOX SIP Call (which does not apply to 

California). Because this AERR was not finalized until after the submittal of the South Coast 2007 AQMP, its data 

requirements, in that they differ from the CERR requirements, do not apply to the South Coast 2007 AQMP.
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2. Emissions Inventories in the South Coast 2007 AQMP

Note: We discuss the CARB‘s statewide inventory to provide background to our evaluation of 

the emission inventories in the South Coast 2007 AQMP. We are not finalizing any SIP action 

on the statewide inventory here, only on the South Coast inventories. EPA will address the 

statewide inventory in a separate rulemaking.

CARB submitted statewide inventories for direct PM2.5 and PM2.5 precursors (except for 

ammonia) as part of the 2007 State Strategy. See Appendix A for the emission inventory output 

tables and Appendix F for documentation of the emissions inventory. Inventories are provided 

for the base year of 2002 and baseline years of 2005, 2006, 2008, 2009, 2010, 2011, 2012, 2013, 

2014, 2015, 2017, 2018, 2020, and 2023.11 These statewide emissions inventories are assembled 

and maintained by CARB in the California Emission Inventory Development and Reporting 

System (CEIDARS) and the California Emission Forecasting and Planning Inventory System 

(CEFS) databases. Both systems are described in Appendix F of the 2007 State Strategy. 

The inventories in Appendix A of the 2007 State Strategy are summer season planning 

inventories on which the 2007 State Strategy is based. Baseline inventories incorporate 

reductions from control measures adopted prior to December 2006. South Coast 2007 AQMP, 

page 3-11, and 2007 State Strategy, Appendix A, p. 1. Specific adjustments for State and 

District rules adopted in the 2004 to 2006 time period, as well as adjustments to among other 

things, heavy duty truck VMT in 2005 and pesticide emissions, are described in the introductory 

section to Appendix A.

The planning inventories for direct PM2.5 and all PM2.5 precursors (including ammonia) 

for the South Coast PM2.5 nonattainment area together with additional documentation for the 

inventories are found in Appendices III and V of the South Coast 2007 AQMP and additional 

documentation from the District.12 Average annual day, winter planning day and average 

summer planning inventories are provided for PM2.5 and PM2.5 precursors for the year 2002 (the 

base year for the attainment and RFP demonstrations), 2005 (the reference year for the air quality 

modeling), and the years 2008, 2010, 2011, 2014, 2017, 2020, 2023, and 2030. The inventories 

use EMFAC2007 for estimating on-road motor vehicle emissions. See South Coast 2007 AQMP 

page 3-1.These inventories provide the basis for the control measure analysis and the RFP and 

attainment demonstrations.

As a starting point for the South Coast 2007 AQMP‘s inventories, the District used 

CARB‘s 2002 base year inventory. The 2002 Inventory was projected to 2005 and future years 

using CEFS. South Coast AQMP, Appendix III, p. III-1-1.

All inventories include emissions from point, area, on-road, and non-road engines. None 

specifically show emissions from non-anthropogenic sources (that is, natural sources) although 

 

11

 The Revised 2007 State Strategy and the 2007 South Coast AQMP address both the 8-hour ozone standard and 

the PM2.5 standards; therefore, baseline inventories are given not only for years of importance for PM2.5 plans but 

also ones of importance for 8-hour ozone plans.

12 Electronic mail from Kathy Hsiao, SCAQMD to Wienke Tax, EPA Region 9, RE: NH3 numbers for SCAB, dated 

October 29, 2010.
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inventories developed for input into the air quality modeling do include such sources. South 

Coast 2007 AQMP, p. 1-4. 

A summary of the planning inventory for the plan‘s base year of 2002 and baseline years 

of 2005, 2008, 2011, and 2014 from the South Coast 2007 AQMP is provided in Table A-1 

below.

3. Proposed Actions on Emissions Inventories

In our November 2010 proposal and July 2011 amended proposal on the South Coast 

2007 PM2.5 SIP, we proposed to find that the 2002 emissions inventory in the 2007 State 

Strategy and the South Coast 2007 AQMP met the CAA section 172(c)(3) requirement for the 

State to submit a plan provision that includes a ―comprehensive, accurate, current, inventory of 

actual emissions from all sources of the relevant pollutant.‖ We also proposed to find that the 

baseline inventories in the South Coast 2007 PM2.5 SIP provided an adequate basis for the 

reasonably available control measure, reasonable further progress and attainment demonstrations 

in the Plan. See 2010 TSD, section II.A. and 75 FR 71294, at 71298; 2011 TSD, section II.A.; 

and 76 FR 41562, at 41567.

4. Evaluation and Conclusions 

The emissions inventories were made available to the public for comment at the same 

time as the draft 2007 State Strategy and the draft 2007 South Coast 2007 AQMP, and were 

subject to public hearing as part of final version of the Strategy and AQMP. See CARB 

Resolution 07-28, p.3, and South Coast Air Quality Management District Governing Board 

Resolution 07-9: June 1, 2007, p. 2.

Consistent with the PM2.5 implementation rule, the South Coast 2007 AQMP uses a 2002 

base year inventory. When considered together with the inventory documentation in Appendix F 

of the State Strategy, Appendix III of the South Coast 2007 AQMP, and the air quality modeling 

documentation in Appendix V of the Plan, it contains all the elements required by EPA‘s 

emission inventory guidance. 

The inventories in the South Coast 2007 AQMP are based on the most current and 

accurate information available to the State and District at the time the Plan was developed and 

submitted (including using the latest EPA-approved version of California‘s mobile source 

emissions model, EMFAC2007), address comprehensively all source categories in the South 

Coast nonattainment area, and meet the applicable requirements of EPA‘s inventory guidance. 

For these reasons, EPA is approving the 2002 base year emissions inventory in the South 

Coast 2007 AQMP as meeting the requirements of CAA section 172(c)(3) and 40 CFR 

§ 51.1008(a)(1). We also find that the baseline inventories in the South Coast 2007 AQMP 

provide an adequate basis for the reasonably available control measure, reasonable further 

progress and attainment demonstrations.
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We received a number of comments on our proposed approval of the emissions 

inventory. We have reviewed these comments and provided responses to them. See section III. of 

this TSD. No issues raised in these comments changed our finding that the emissions inventories 

in the South Coast 2007 AQMP for PM2.5 are consistent with the applicable requirements of the 

CAA and EPA guidance.

Post-Submittal Revisions to the Plan’s Base Year and Projected Baseline Inventories

From late 2007 until mid-2009, California has experienced an economic recession that

greatly reduced and continues to affect the level of activity in the State‘s construction and goods 

movement sectors. 2011 Progress Report, Appendix E. As a result, current and projected 

emission levels from these categories are now substantially lower than were projected in the 

South Coast 2007AQMP. At this time, EPA will reflect these recession impacts (in combination 

with the technical corrections to the inventory discussed below) as a line-item adjustments to the 

baseline inventories.

These recession-caused decreases in emissions do not affect either the Plan‘s base year 

(2002) or modeling year (2005) inventories and thus do not change the carrying capacity 

estimates in the Plan (that is, they do not affect the target level of overall emissions needed to 

demonstrate attainment) or the starting point for the reasonable further progress demonstration. 

Their principal effect is to reduce the reductions needed from the Plan‘s control strategy to 

demonstrate RFP and attainment. 

CARB also made technical changes to the inventory for diesel trucks and buses as part of 

its December 2010 rulemaking amending its In-Use On-Road Truck and Bus Rule. These 

included updates and revisions to:

regional allocation factors

out-of-state vehicle miles traveled estimates

new vehicle inventory categories

lifetime mileage assumptions

See CARB, Staff Report: Initial State of Reasons for Proposed Rulemaking, Proposed 

Amendments to the Truck and Bus Regulations, The Drayage Truck Regulation and the TractorTrailer Greenhouse Gas Regulation, October 2010, p. 17.

CARB also comprehensively updated and revised the inventory for off-road equipment as 

part its December 2010 rulemaking amending the In-Use Off-Road Equipment Rule. These 

included updates and revisions to the:

equipment population

hours of use

load factors

future equipment sales and activity

See CARB, Staff Report: Initial State of Reasons for Proposed Rulemaking, Proposed 

Amendments to the Regulation for In-Use Off-Road Diesel-Fueled Fleets and the Off-Road 

Large Spark-Ignition Fleet Requirements, October 2010, pp. 16-17.

CARB estimates that these technical revisions reduce the total 2002 base year NOx and 

PM2.5 inventory by approximately 4 percent and 5 percent, respectively. CARB Progress Report 

Supplement, Attachment 1. We took the difference between the ―SIP‖ estimate and the ―Current 
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Estimate‖ columns in Attachment 1, Table SC-2002, to the May 18 letter and divided by the 

―SIP‖ estimate to calculate the percent change in the inventories. These change are small enough 

that we do not believe they affect the overall accuracy of the inventory given the normal and 

unavoidable uncertainties in emissions inventories. 

We have also considered the potential effects of the revisions to the truck, bus, and offroad equipment emissions inventory categories on the approvability of the attainment and RFP 

demonstrations and the contingency measure provisions in the Plan and concluded they do not 

adversely affect them. See sections II.D.1. and II.H. of this TSD. We note that the State and 

District are currently working on a revision to the South Coast PM2.5 SIP to address the 2006 24-

hour PM2.5 standard. These revisions are due to EPA in December 2012 and will, as required by 

CAA section 172(c)(3), include the latest updates to the emissions inventories.

Both the South Coast and San Joaquin Valley Districts reviewed and evaluated the 

changes to the CARB baseline inventories from changes to the emissions inventories for the 

diesel heavy duty truck, bus, and off-road equipment categories. Both Districts concluded that 

the emissions inventory changes for these categories were improvements compared to the 2007 

State Strategy inventories for these categories. See letter, Barry Wallerstein, Executive Officer, 

SCAQMD, and Seyed Sadedrin, Executive Director, SJVUAPCD, to James Goldstene, 

Executive Officer, CARB, dated December 14, 2010.
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Table A-1. Emission Inventory Summary for the South Coast PM2.5 Nonattainment Area

(tons per day)

Annual Average Day Winter Average Day

2002 2005 2008 2011 2014 2002 2005 2008 2011 2014

NOx

Stationary and Area 

Sources 93 95 87 78 76.4 100 104 96 88 86

On-Road Mobile 

Sources 628 576 435 361 292 680 620 468 387 312

Off-Road Mobile 

Sources 372 358 332 303 285 367 352 324 296 278

Total 1093 1029 854 743 654 1147 1076 889 771 677

VOC

Stationary and Area 

Sources 302 267 245 250 257 303 272 252 258 265

On-Road Mobile 

Sources 362 298 210 172 144 382 316 223 182 153

Off-Road Mobile 

Sources 180 175 153 137 127 158 158 138 125 116

844 740 608 559 528 843 746 614 565 533
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Table A-1. Emission Inventory Summary for the South Coast PM2.5 Nonattainment Area

(tons per day)

Annual Average Day Winter Average Day

2002 2005 2008 2011 2014 2002 2005 2008 2011 2014

Total

PM2.5

Stationary and

Area Sources 60.1 64.7 65.19 66.8 68.5 66.6 76.9 77.6 79.52 81.6

On-Road Mobile 

Sources 18.1 19.8 17.75 17.30 16.83 18.2 19.8 17.8 17.33 16.9

Off-Road Mobile 

Sources 20.9 21.1 18.56 17.5 16.26 19.6 19.8 17.0 15.74 14.3

Total 99 105.6 101.50 102 102 106 116 112 113 113

SOx

Stationary Sources

Area Sources 21.7 22.2 16.60 16.35 16.24 23 23 17.46 17.20 17.10

On-Road Mobile 

Sources 4.3 4.3 2.10 2.15 2.22 4.2 4.3 2.05 2.10 2.18

Off-Road Mobile 

Sources

27.3 35.2 22.2 21.51 24.4 27.3 35 22.1 21.5 24.4

Total 53.3 61.7 40.9 40.01 42.8 53.5 62.5 41.7 40.8 43.6
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Table A-1. Emission Inventory Summary for the South Coast PM2.5 Nonattainment Area

(tons per day)

Annual Average Day Winter Average Day

2002 2005 2008 2011 2014 2002 2005 2008 2011 2014

NH3

Stationary Sources

Area Sources

n/a 75 n/a n/a 68 n/a n/a n/a n/a n/a

On-Road Mobile 

Sources

n/a 29 n/a n/a 15 n/a n/a n/a n/a n/a

Off-Road Mobile 

Sources

n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a

Total 104 n/a n/a 83 n/a n/a n/a n/a n/a

Source: South Coast 2007 AQMP, Appendix III, Tables A-2, A-3, A-5, A-6, C-2, C-3, C-5, C-6 and electronic mail from Kathy Hsiao, SCAQMD to Wienke 

Tax, EPA Region 9, ―RE: NH3 numbers for SCAB,‖ dated October 29, 2010. n/a = not available
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B. Air Quality Modeling

1. Requirements for Air Quality Modeling

CAA section 172(c)(1) requires states to submit a plan which ―shall provide for 

attainment of the national primary ambient air quality standards.‖ Pursuant to this section, the 

PM2.5 implementation rule requires the State to submit, within three years of the designation of 

one of its areas as nonattainment, an attainment demonstration showing that the area will attain 

the annual and 24 – hour standards as expeditiously as practicable. 

 

The PM2.5 implementation rule requires states to submit an attainment demonstration 

based on modeling results. 40 CFR § 51.1007, Attainment demonstration and modeling 

requirements, (a) states:

For any area designated as nonattainment for the PM2.5 NAAQS, the State must submit 

an attainment demonstration showing that the area will attain the annual and 24-hour 

standards as expeditiously as practicable. The demonstration must meet the requirements 

of 40 CFR § 51.112 and Appendix W of this part and must include inventory data, 

modeling results, and emissions reduction analyses on which the State has based its 

projected attainment date. The attainment date justified by the demonstration must be 

consistent with the requirements of 40 CFR § 51.1004(a). The modeled strategies must be 

consistent with requirements in 40 CFR § 51.1009 for RFP and in 40 CFR § 51.1010 for 

RACT and RACM. The attainment demonstration and supporting air quality modeling 

should be consistent with EPA‘s PM2.5 modeling guidance.‖13

See also 72 FR 20586 at 20665. 

The procedure for modeling PM2.5 as part of an attainment SIP are contained in EPA‘s 

―Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air

Quality Goals for Ozone, PM2.5 and Regional Haze,‖ EPA -454/B-07-002, April 2007, available 

at: http://www.epa.gov/ttn/scram/guidance/guide/final-03-pm-rh-guidance.pdf (Guidance).

Overview of the EPA Recommended Modeled Attainment Test for PM2.5

A modeled attainment test is an exercise in which an air quality model is used to simulate 

current and future air quality. If future estimates PM2.5 concentrations are less than the NAAQS, 

then this element of the attainment test is satisfied. Our recommended test is one in which model 

estimates are used in a ―relative‖ rather than ―absolute‖ sense. That is, we take the ratio of the 

model‘s future to current (baseline) predictions at monitors. We call these ratios, relative 

response factors (RRF). Future PM2.5 concentrations are estimated at existing monitoring sites 

by multiplying a modeled relative response factor at locations ―near‖ each monitor by the 

 

13 EPA‘s November 9, 2005 final rule revising the ―Guideline on Air Quality Models‖ in 40 CFR part 51, Appendix 

W is available at www.epa.gov/ttn/scram/guidance/guide/appw_05.pdf.
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observation-based, monitor-specific, ―baseline‖ design value. The resulting predicted ―future 

concentrations‖ are compared to NAAQS.

The PM2.5 attainment test reflects the fact that PM2.5 is a mixture. In the test, ambient

PM2.5 is divided into major components. These are: mass associated with sulfates, nitrates, 

ammonium, organic carbon, elemental carbon, particle bound water, ―other‖ primary inorganic 

particulate matter, and passively collected mass.

A separate RRF is calculated for each of the PM2.5 components (except passive mass). 

We call each of these site-specific ratios, component-specific RRFs. Future PM2.5 design values 

are estimated at existing monitoring sites by multiplying modeled relative response factors 

―near‖ each monitor times the observed ―component specific design value‖. This latter quantity 

is estimated using measured site-specific design values for PM2.5 in concert with available 

measured composition data. Future site-specific PM2.5 design values at a site are estimated by 

adding the future year values of the seven PM2.5 components. If all future site-specific PM2.5

design values are less than or equal to the concentration specified in the NAAQS, the test is 

passed.14

2. Overview of the Conceptual Description, Modeling Approach, and Modeling 

Protocol in the South Coast 2007 AQMP

The South Coast 2007 AQMP provides information on the air quality modeling, air 

quality data, and meteorological data in Appendix V. Chapter 1 discusses the overall modeling 

approach for PM2.5 as well as other pollutants. Chapter 2 provides a discussion of the analysis 

for PM2.5. The Modeling Protocol is provided in Attachment 3 to Appendix V. The following 

description of the modeling approach is provided in Appendix V, Chapter 1, Chapter 2, and 

Attachment 3. 

a. Conceptual Description

The federal reference method (FRM) data depicted in Figure V-2-3, below, clearly 

delineates the extent of the PM2.5 problem in the Basin. PM2.5 is essentially a combustion 

generated pollutant and with the volume of traffic flow, numbers of sources (both point and area) 

located in the region, concentrations exceed the annual federal standard (15 μg/m3) throughout 

the South Coast nonattainment area. The area with the highest annual concentration includes 

southwest San Bernardino and Northwest Riverside Counties. These areas have design values 

exceeding 20 μg/m3 and encompass both the Fontana and Rubidoux air monitoring stations. It is 

important to note that the areas with the highest concentrations are directly downwind of a major 

ammonia source area associated with dairies and poultry farming. These industries are rapidly 

moving from the Basin and are expected to contribute significantly less to particulate formation 

in future years.15

 

14 Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for 

Ozone, PM2.5, and Regional Haze‖, EPA -454/B-07-002, April 2007 p. 15-16.

15 South Coast 2007 AQMP, Appendix V p. V-2-10.
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Figure V-2-3 2005 South Coast Air Basin Annual PM2.5 (μg/m3)16

Figure V-2-1: MATES-III 2005 Annual Distribution of PM2.5 Species (μg/m3)

 

16 South Coast 2007 AQMP, Appendix V, p. V-2-11.
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In general, the organic carbon mass accounts for approximately 30 percent of the total 

mass (adjusted for the negative contribution of the other category) at each station. Ammonium, 

sulfate and nitrates account for an approximate 45 percent of the total mass at each location. 

Rubidoux and Fontana are the most heavily impacted by nitrates. Sulfate is highest in the near 

coastal or ports of Los Angeles/Long Beach areas, particularly Wilmington and Long Beach. EC 

and metals measurements were highest at Wilmington accounting for almost 24 percent of the 

mass when combined. All sites observed measurable concentrations of sodium and chloride ions 

reflecting the influence of the marine air as it is transported inland.17

b. Annual PM2.5 Modeling Approach

In the Final 2007 AQMP, CAMx annual average PM2.5 modeling simulations were 

generated for 2005, 2014 and 2020 baseline emissions and 2014 and 2020 controlled emissions 

scenarios. The 2005 CAMx simulation was conducted using baseline monthly temperature and 

humidity corrected emissions, for a weekday, Saturday and Sunday activity profile. Seasonal 

boundary conditions were extracted from the Western Regional Air Partnership (WRAP) 

regional modeling simulations (initialized from global air quality model output) in support of the 

Regional Haze Rule demonstrations. The simulations were driven by MM5 meteorological 

fields; five day-simulations with a one day ―ramp-up‖ period using NCEP model initialization.18

CAMx simulations used the same region (5 km squared grid, 280 easting and 3650 

northing, 65 by 40 grid cells) as that used for the 2003 UAMAERO-LT analyses. The vertical 

structure was increased to 11 layers (compared with the 5-layer analysis of UAMAERO-LT), but 

less than the 19 layers used for the MM5 simulations in an effort to conserve computational 

resources. MM5 was used to generate the meteorological profile for each day in 2005. The MM5 

simulations were generated for the larger SCOS97 modeling domain employing a 5 km square 

grid and fit to the smaller PM2.5 grid. 

The MM5 simulations were initialized from NCEP analyses and run for 5-day increments 

without the four-dimensional-data-assimilation (FDDA) option. Speciated PM2.5 data measured 

from the District‘s Multiple Air Toxic Evaluation Program (MATES-III) during 2005 provided 

the characterization for evaluation and validation of the CAMx annual and episodic 

demonstrations.

Model performance was evaluated against monitored particulate PM2.5 air quality data for 

six species (ammonium, nitrates, sulfates, organic carbon, elemental carbon, and primary) and 

total particulate mass. Annual data from eight MATES-III monitoring sites, including Los 

Angeles, Anaheim, Wilmington, Long Beach, Compton, Burbank, Rubidoux, and Fontana, were 

used in the validation. The future year attainment demonstration was analyzed for 2014 

controlled emissions, thus enabling an annual demonstration based on a control strategy that 

would be fully implemented by January 1, 2015.

Future year PM2.5 air quality (2014 and 2020) was determined using site and species 

specific RRF‘s applied to 2005 PM2.5 design values per EPA guidance documents. The quarterly 

 

17 South Coast 2007 AQMP, Appendix V, p.V-2-5.

18 South Coast 2007 AQMP, Appendix V, p. V-1-7, V-1-8.
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RRF‘s were calculated from the controlled 2014 simulation and the 2005 baseline simulation. 

The design values were determined from the federal reference method Size Selective Inlet (SSI) 

High-Vol PM2.5 data measured at the District‘s air monitoring network from 2003-2005. The SSI 

PM2.5 design values were calculated by quarter then apportioned by species based on the 

distribution observed in the MATES-III data.

c. Episodic 24-Hr Average PM2.5 Modeling Approach

Two options are provided to determine RRFs for the future year 24- hour average PM2.5

attainment demonstration. The first option uses episodic modeling with day-specific emissions 

for representative meteorological episodes to calculate RRFs and apply the RRF to the design 

value. The second approach proposed by EPA relies on an average response to implementation 

of emissions control for the top 25 percentile of days in each quarter of the annual model 

simulation. The maximum 24-hour PM2.5 design value (based on 2003-2005 data) for the Basin 

(64.8 μg/m3) meets the current federal standard. Of great interest is how will the 24 hour PM2.5

concentration fair compared to the new standard of 35 μg/m3 when that standard become 

effective in 2010. On the basis of our initial simulations and analysis, the District staff feels that 

the future design calculation based on the top 25 percentile day, quarterly is more conservative 

than the episodic modeling. AQMD recommends the use of the 25 percentile approach. 19

Episodic Simulations

The first approach to determine future year 24-hour maximum or 98th percentile PM2.5

impacts relied on the simulation of one or more representative peak PM2.5 episodes where 

observed concentrations exceed 65 μg/m3. The peak PM2.5 24-hour average concentration 

observed in the Basin during the 2005 MATES-III monitoring program (110 μg/m3 at Rubidoux) 

occurred on October 22, 2005. Episode specific emissions for the peak and preceding days were 

temperature and humidity corrected and MM5/FDDA simulations were generated to provide the 

meteorological input.20

Quarterly Top 25 Percentile

For this approach, the 2005 observational data are sorted by quarter of year and further 

into the top 25 percent of days in each quarter. PM2.5 RRFs are calculated on a quarterly basis 

from the future and base year annual simulations for only those days in the top 25 percentile per 

quarter. The quarterly RRFs for the ―top 25 percent days‖ are then applied to the quarterly 24-

hour average PM2.5 design values to develop quarterly future year design values which are later 

aggregated into an annual 24-hour future year design value to assess attainment. (The measured

quarterly 24-hour average PM2.5 design values were comprised of the 98th percentile data in each 

quarter for the years 2003, 2004 and 2005). Several variations of the episodic and quarterly top 

25 percentile future year calculations were conducted and are presented and discussed in Chapter 

2. 21

 

19 South Coast 2007 AQMP, Appendix V, p. V-1-8

20 South Coast 2007 AQMP, Appendix V, p. V-1-9

21 South Coast 2007 AQMP, Appendix V, p. V-1-9
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d. Modeling Protocol, Peer Review, and Advisory Committee

The Modeling Protocol for Ozone and Particulate Matter Modeling in Support of the 

South Coast Air Quality Management District 2007 Air Quality Management Plan Update Draft 

Report May 9, 2006, and a Summary of Preliminary Critiques of Peer Reviewers of the 

Modeling Protocol are included in the South Coast 2007 AQMP.22

The protocol for the South Coast 2007 AQMP was reviewed by a technical and advisory group.

The Scientific, Technical, and Modeling Peer Review Advisory Group (STMPRAG) role 

expands upon that of the MWG and includes experts in socioeconomic assessment and 

human health, providing review of AQMD modeling, monitoring and related scientific 

issues. The STMPRAG assists AQMD in resolving technical issues related to air quality 

and socio-economic modeling by providing ongoing technical review and consensus of 

procedures and analyses. The STMPRAG consists of approximately 20 members 

appointed by the Governing Board, with representatives from USEPA, CARB, Southern 

California Association of Governments (SCAG), the California Small Business Alliance 

(CSBA), Southern California Edison (SCE), Western States Petroleum Association 

(WSPA), and technical experts from universities and consultant firms.23

3. Air Quality Model Selection

EPA Recommendations

A model should meet several general criteria for it to be a candidate for consideration in 

an attainment demonstration or uniform rate of progress assessment. These general criteria are 

consistent with requirements in 40 CFR 51.112 and 40 CFR part 51, Appendix W (U.S. EPA,

2005d). We are not recommending a specific model for use in attainment demonstration or 

uniform rate of progress assessment. At present, there is no single model which has been 

extensively tested and shown to be clearly superior than its alternatives. Thus, 40 CFR Part 51 

Appendix W does not identify a ―preferred model‖ for use in attainment demonstrations of the 

NAAQS for . Based on the language in 40CFR Part 51 Appendix W, models used for these 

purposes should meet requirements for ―alternative models‖. 24

States/Tribes should use a non-proprietary model, which is a model whose source code is 

available for free (or for a ―reasonable‖ cost). Furthermore, the user must be able to revise the 

code to perform diagnostic analyses and/or to improve the model‘s ability to describe 

observations in a credible manner. Several additional prerequisites should be met for a model to 

be used to support an attainment demonstration.

 

22 South Coast 2007 AQMP, Appendix V, Attachments 3 and 4.

23 South Coast 2007 AQMP, Appendix V, Attachment 3, p.20 DRAFT Modeling Protocol for Ozone And 

Particulate Matter Modeling in Support of the South Coast Air Quality Management District 2007 Air Quality 

Management Plan Update Draft Report May 9, 2006.

24 Guidance p.136.
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(1) It should have received and been revised in response to a scientific peer review.

(2) It should be appropriate for the specific application on a theoretical basis.

(3) It should be used with a data base which is adequate to support its application.

(4) It should be shown to have performed well in past ozone or PM modeling applications.

(If the application is the first for a particular model, then the State should note why it believes the 

new model is expected to perform sufficiently.)

(5) It should be applied consistently with a protocol on methods and procedures.

South Coast 2007 AQMP

The selection process, models considered, issues, and comments for the air quality and 

meteorological models are discussed in the modeling protocol on pages 25-27, and summarized 

in Table 3: Summary of Proposed 2007 AQMP Model Selection and Application, of the 

modeling protocol.25

The Final South Coast 2007 AQMP employs CAMx using the ―one atmosphere‖ 

approach comprised of the CB-IV gas phased chemistry and a static two-mode particle 

size aerosol module as the particulate modeling platform. 26

The preliminary PM2.5 modeling approach crafted for the South Coast 2007 AQMP was 

to move the empirical AERO-LT chemistry from the UAM to CAMx to take advantage 

of the advanced dispersion platform. Parallel testing was conducted to evaluate the 

CAMx/AERO-LT performance against CAMx using the ―one atmosphere‖ approach 

comprised of the CB-IV chemistry and a static two-mode particle size aerosol module. 

The results of the analysis indicated that the two model/chemistry packages were 

performing similarly and that the speed of simulating an annual average using CAMx 

―one atmosphere‖ was approximately equal to that of the AERO-LT combination. As a 

consequence, the PM2.5 modeling approach shifted to the use of the CAMx ―one 

atmosphere‖ as the primary tool.27

Discussion

EPA believes that the modeling platform selected for the 2007 was appropriate for the PM2.5

modeling which was used as a basis for the attainment demonstration in the 2007 AQMP.

4. Episode Selection

EPA Recommendations

The South Coast 2007 AQMP uses the first of the two recommended approaches, 

described below.

 

25 South Coast 2007 AQMP, Appendix V, Attachment 3, p.13-18 DRAFT Modeling Protocol for Ozone And 

Particulate Matter Modeling in Support of the South Coast Air Quality Management District 2007 Air Quality 

Management Plan Update Draft Report May 9, 2006.

26 South Coast 2007 AQMP, Appendix V, p. V-1-6.

27 South Coast 2007 AQMP, Appendix V, p. V-1-7.
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Model every day for a full year (or multiple years). This is recommended for both 

dispersion modeling of primary PM2.5 components and photochemical modeling of secondary 

and primary components. Many areas that violate the 24-hour PM2.5 NAAQS will also violate 

the annual PM2.5 NAAQS. Therefore, full year modeling may already exist or is being planned 

for the annual NAAQS attainment test. States that have nonattainment areas that violate both 

PM2.5 standards should take advantage of planning opportunities to address both standards at the 

same time. Modeling at least a full year will also help ensure that a sufficient number of days are 

included in the RRF calculations.28

South Coast 2007 AQMP

Annual PM2.5 Modeling 

In the Final 2007 AQMP, CAMx annual average PM2.5 modeling simulations were 

generated for 2005, 2014 and 2020 baseline emissions and 2014 and 2020 controlled 

emissions scenarios. The 2005 CAMx simulation was conducted using baseline monthly 

temperature and humidity corrected emissions, for a weekday, Saturday, and Sunday 

activity profile.29

Episodic Simulations

The first approach to determine future year 24-hour maximum or 98th percentile PM2.5

impacts relied on the simulation of one or more representative peak PM2.5 episodes where 

observed concentrations exceed 65 μg/m3. The peak PM2.5 24-hour average concentration 

observed in the Basin during the 2005 MATES-III monitoring program (110 μg/m3 at 

Rubidoux) occurred on October 22, 2005. Episode specific emissions for the peak and 

preceding days were temperature and humidity corrected and MM5/FDDA simulations 

were generated to provide the meteorological input. 

Discussion

EPA believes that the modeling of the full year for 2005, and along with the episode 

specific modeling meets EPA recommendations for episode selection. 

5. Domain Size and Spatial Resolution 

a. Domain Size 

EPA Recommendations

The principal determinants of model domain size are the nature PM2.5 problem and the 

scale of the emissions which impact the nonattainment area. Isolated nonattainment areas that are 

not impacted by regional transport of PM and its precursors may be able to use a relatively small 

domain. Some areas of the western U.S. may fall into this category. The modeling domain 

 

28 Guidance p. 147

29 South Coast 2007 AQMP, Appendix V, p. V-1-8.
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should be designed so that all major upwind source areas that influence the downwind 

nonattainment area are included in the modeling domain. The influence of boundary conditions 

should be minimized to the extent possible.30

South Coast 2007 AQMP

Modeling Domain

The CAMx modeling domain was defined by 2600 5 km squared grid cells a Universal 

Transverse Mercator (UTM) projection beginning at 275 easting through 3670 northing, using a 

65 by 40 grid cell structure. This is same grid specification that was used for the 2003 

UAMAERO-LT analyses. Figure V-2-4 depicts the modeling domain.

The PM2.5 domain extends approximately 80 km offshore to the west of the middle Basin. The 

domain captures the international shipping routes that extend parallel to the coast (northwest and 

southeast) and due west from the port areas. The northern boundary of the domain extends to 

Santa Barbara County and Kern County while the southern boundary resides primarily in 

Northern San Diego County. The desert portions of Riverside, San Bernardino and Imperial 

counties define the eastern31 boundary of the modeling domain. The modeling domain is smaller 

than both the ozone modeling and MM5 domain. The vertical structure for the CAMx modeling 

was increased to 8 layers of varying depth (compared with the 5-layer analysis of UAMAEROLT) but less than the 19 layers used for the MM5 simulations in effort to conserve computational 

resources. The top of the modeling domain was set at 5,000 m.

 

30 Guidance p. 152

31 South Coast AQMP, Appendix V, p. V-2-15, V-2-16.
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Figure V-2-4: PM2.5 Modeling Domain

Discussion

EPA believes that the air quality model domain size is appropriate, considering the nature 

PM2.5 problem, and the scale of the emissions which impact the nonattainment area. EPA 

believes that the modeling domain is sufficiently large so that all major upwind source areas that 

influence the downwind nonattainment area are included in the modeling domain, and the 

influence of boundary conditions are minimized to the extent possible.

b. Horizontal Resolution

EPA Recommendations

The bottom line of the preceding discussion is that we feel comfortable recommending 

that States may use grid cell sizes as large as 12 km for urban scale applications addressing 

secondary components of particulate matter. We are less sure about an acceptable upper limit for 

cell size in applications addressing primary components. We believe it is prudent to assume that, 

in some cases, cells as small as 4 km (or possibly smaller) are needed. Those implementing the 

modeling/analysis protocol may wish to perform a diagnostic test using a grid model without 

chemistry to see whether estimated RRF‘s for primary components are affected if one decreases 
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the grid cell size from 12 km to 4km. Alternatively, large sources of primary PM can be modeled 

with a dispersion model or a combination of grid and dispersion models (see Section 5.3). 32

South Coast 2007 AQMP

For the South Coast 2007 AQMP ozone, particulate and meteorological modeling, a 

horizontal grid resolution of 5 km is proposed to be used for the air quality modeling. No 

grid nesting is anticipated. This resolution is consistent with the grid resolution used in 

earlier photochemical modeling studies for the South Coast Air Basin and for San Diego. 

In addition, this will reduce resources needed to create gridded emissions, which are 

based on 5 km grid cells 33

Discussion

EPA believes the grid resolution of 5 km is meets EPA recommendations for this 

application.

c. Vertical Layers

EPA Recommendations

There is no correct minimum number of vertical layers needed in an attainment 

demonstration. The vertical resolution will vary depending on the application. Recent 

applications of one atmosphere models (with model tops at 100mb) have used anywhere from 12 

to 21 vertical layers with 8-15 layers approximately within the boundary layer (below 2500m) 

and 4-6 layers above the PBL.34

South Coast 2007 AQMP

The vertical structure for the CAMx modeling was increased to 8 layers of varying depth 

(compared with the 5-layer analysis of UAMAERO-LT) but less than the 19 layers used for the 

MM5 simulations in effort to conserve computational resources. The top of the modeling domain 

was set at 5,000 m.35 The modeling protocol includes a table which lists the Vertical Structures 

for the CAMx Ozone and PM Simulations with Corresponding MM5 Meteorological Model 

Layers.36

 

32 Guidance p. 157

33 South Coast 2007 AQMP, Appendix V, Attachment 3, Modeling protocol p.34.

34 Guidance p. 159

35 South Coast 2007 AQMP, Appendix V, p V-2-16.

36

 2007 AQMP, Appendix V, Attachment 3, p.38 DRAFT Modeling Protocol
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Discussion

EPA believes that the number of vertical layers in the 2007 AQPM meets EPA‘s 

recommendation for number of vertical layers.

6. Initial and Boundary Conditions

EPA Recommendations

If there is no larger regional model application available, then it is recommended that 

background boundary conditions be used to specify initial and boundary concentrations for the 

attainment demonstration modeling. However, concentration fields derived from a larger domain 

regional or global chemistry model (i.e. nesting approach) is considered more credible than the 
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assumption of static concentrations, since the pollutant concentration fields reflect simulated 

atmospheric chemical and physical processes driven by assimilated meteorological observations. 

Therefore, we recommend using boundary conditions derived from a regional or global scale 

model, whenever possible. Diagnostic testing which indicates a large impact on the model results 

from initial or boundary conditions may indicate that the domain is not large enough or the rampup period is too short. In either case, it should generally be assumed that initial and boundary 

conditions do not change in the future. The use of altered initial or boundary conditions in the 

future year should be documented and justified. 37

South Coast 2007 AQMP

Boundary, Top Conditions

One of the more difficult tasks of the modeling analysis was to determine a method to 

define the boundary and top conditions for the PM2.5 simulations. Three options were 

considered for the analysis: (1) assume clean conditions, (2) use the ozone modeling to 

generate concentration files at the PM2.5 grid boundary, or (3) use hemispheric or global 

chemistry model output to specify the boundaries. Option-3 with minor adjustments was 

selected for the attainment demonstration.

The Western Regional Air Partnership (WRAP) has been simulating hemispheric 

particulates with a focus on the western U.S. as part of the Regional Haze Rule 

demonstration using CAMx on a coarse grid extending into the Pacific Ocean. Model 

output from the WRAP analysis for model year 2002 was extracted and converted to 

develop hourly boundary conditions for the PM2.5 modeling analyses. For this analysis it 

is assumed that little uncertainty is introduced into the modeling using the 2002 boundary 

data. The WRAP modeling used CB-IV gaseous chemistry as does the Final 2007 AQMP 

PM2.5 CAMx modeling. The WRAP modeling was conducted on a Lambert Conformal 

grid and therefore specification of the boundary conditions required remapping to the 

UTM coordinate system. Additional vertical layer averaging and remapping to the PM2.5

grid assumed that the concentration is uniform across each vertical layer.

The boundary and top concentration input files for the PM model were created on a 

month by month basis. The files were derived by averaging the WRAP simulation 

concentrations at each boundary point, vertical layer for each hour of the day over the 

course of a month. The values of the various boundary species were averaged over the 

entire top of the modeling domain for every hour in a month to create the top 

concentration files. The CAMx top concentration file only uses one concentration value 

for the top of the model for the entire simulation. Table V-2-7 provides the representative 

results for February and August. Initial PM2.5 performance with the WRAP boundary 

conditions suggested that Sox concentrations along the western boundary in the shipping 

lanes were too low. A minimum concentration of 5 ppb SO2 was set for the southern 

boundary extending westward from the San Diego coast to approximately 20 km offshore 

after which the concentration was phased to a value less than 1 ppb at the extreme 

southwest corner of the modeling domain. A similar adjustment was made along the 

 

37 Guidance p. 154.
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north-south boundary with SO2 being set at 5 ppb from the coast of Santa Barbara south 

to approximately 15 km offshore, again being reduced to less than 1 ppb at the southwest 

corner of the domain.38

Future Boundary, Top and Initial Air Quality Conditions

For the future year scenarios, the boundary, region top and ambient air quality 

concentrations were adjusted to reflect projected emissions reductions from the 2005 

base-year.

Discussion

EPA believes that the boundary and top conditions are appropriate for this application. 

The South Coast 2007 AQMP states that the future year initial and boundary conditions were

adjusted, but does not discuss the methodology for this adjustment. The methodology should be 

discussed in the mid-course correction.

7. Meteorological Model 

EPA Recommendations

a. Meteorological Model Selection

A description of the methods used to generate the meteorological fields should be 

included in the modeling protocol. In cases in which standard meteorological modeling (e.g., 

MM5, RAMS, or WRF in a retrospective analysis mode) is not used, it is recommended that a 

detailed description of the technique that is used to generate the three-dimensional 

meteorological fields be shared with the appropriate EPA regional office(s) prior to conducting 

the air quality modeling analysis. 39

b. Meteorological Model Domain

It is expected that most attainment demonstrations will cover large areas and use nested 

grids. The outermost grid should capture all upwind areas that can reasonably be expected to 

influence local concentrations of ozone, and/or . In terms of selecting an appropriate 

meteorological modeling domain, one should extend the grid 3 to 6 cells beyond the domains of 

each air quality modeling grid to avoid boundary effects. For example, if 4 km grid cells are to 

be used in the fine portion of a nested regional air quality model, then the meteorological fields 

at this detail would need to extend 12-24 km beyond the bounds of the 4 km grid used for air 

quality predictions. In terms of grid resolution, EPA recommends that the dynamic 

meteorological models use the same grid resolution as desired for the air quality model 

applications. In some cases, however, this may not always be feasible. One possible reason for 

modeling with meteorology using a different grid resolution is in the case of unacceptable model 

performance from the meteorological model at the desired grid resolution. In other instances, the 

 

38 South Coast 2007 AQMP, Appendix V, p. V-2-17.

39 Guidance p. 161.
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need for finer resolution may be emissions-driven more than meteorologically-driven and the 

costs do not warrant the generation of additional resolution in the meteorological data. In these 

specific situations it is recommended that the air quality model application use available results 

from meteorological models on the next coarser scale (i.e., 36 km for a desired 12 km estimate, 

12 km for a desired 4 km estimate). The coarse grid meteorological fields can be mapped to the 

more finely resolved air quality modeling domain. 

c. Data Assimilation

As noted above, the use of FDDA helps to keep the model predictions from widely 

diverging from what was actually observed to occur at a particular point in time/space. However, 

if used improperly, FDDA can significantly degrade overall model performance and introduce 

computational artifacts (Tesche and McNally, 2001). Inappropriately strong nudging coefficients 

can distort the magnitude of the physical terms in the underlying atmospheric thermodynamic 

equations and result in "patchwork" meteorological fields with strong gradients between near-site 

grid cells and the remainder of the grid. Additionally, if specific meteorological features are 

expected to be important for predicting the location and amount of pollution formed, based on an 

area's conceptual model, then the meteorological modeling should be set up to ensure that FDDA 

does not prevent the model from forming these features (e.g. nocturnal low-level wind jets). In 

general, analysis nudging strengths should be no greater than 1.0 x 10-4 for winds and 

temperatures and 1.0 x 10-5 for humidity. In the case of observation nudging (i.e., FDDA based 

on individual observations as opposed to analysis fields), it is recommended that the resultant 

meteorological fields be examined to ensure that the results over the entire domain are still 

consistent. Further, based on past experience, we recommend against using FDDA below the 

boundary layer for thermodynamic variables like temperature and humidity because of the 

potential for spurious convection. If the dynamic model is applied without FDDA, it is suggested 

that the simulation durations be shorter than 24 hours.

d. Meteorological Model Performance

Operational Evaluation: The operational evaluation results should focus on the values and 

distributions of specific meteorological parameters as paired with and compared to observed 

data. It is recommended that the observation - model matching be paired as closely as possible in 

space and time. Typical statistical comparisons of the key meteorological parameters105 will 

include: comparisons of the means, mean bias, mean normalized bias, mean absolute error, mean 

absolute normalized error, root mean square error (systematic and unsystematic), and an index of 

agreement. For modeling exercises over large domains and entire ozone seasons or years, it is 

recommended that the operational evaluation be broken down into individual segments such as 

geographic subregions and/or months/seasons to allow for a more comprehensive assessment of 

the meteorological strengths and weaknesses.40

 

40 Guidance p. 163-167.
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South Coast 2007 AQMP

The selection process for the meteorological model is discussed in the Model Protocol.

41

 

The models considered are listed in Table 3: Summary of Proposed 2007 AQMP Model 

Selection and Application.42

South Coast 2007 AQMP Meteorological Modeling Approach

The SCOS97 field study generated a dataset with a relatively high spatial density of 

meteorological observations. While this dataset suggests that an objective/diagnostic 

model could be adequate to develop the meteorological parameter fields required for air 

quality modeling of the August SCOS97 episode, there are large portions of the modeling 

domain—such as over the ocean or the inland desert—where there are few observations. 

The approach for the 2007 AQMP modeling will be to use the MM5 prognostic model 

with a 5 km grid resolution. The meteorological boundary conditions for MM5 are 

generated using the output from a Global Climate Model (GCM) with a relatively coarse 

grid of 45 km. The MM5 prognostic model uses more accurate and complete physics than 

the diagnostic models used previously. The MM5 has relatively good replication of 

meteorological features of the Basin, such as the coastal eddies, Santa Ana winds, 

recirculation, & strong inversions. The recent air quality models are designed to use 

inputs from the prognostic models, such as MM5, and the use of such a model is strongly 

encouraged by USEPA. In the past, the use of MM5 meteorological fields in air quality 

models has brought limited success in the prediction of peak ozone concentrations that 

result from extreme meteorological conditions and complex distribution of precursor 

emissions. However, the prediction of ozone with MM5 meteorological fields on most 

days is comparable to the results using other models. Since the air quality model will be 

employed in more of a relative sense for the 2007 AQMP, with the use of relative 

reduction factors instead of peak concentration comparisons, the MM5 is an appropriate 

choice for the AQMP modeling. The premise is that the magnitude of RRF will reflect 

the ozone concentration resulting from the various meteorological episode classifications. 

With the use of the MM5 meteorological model, the AQMP modeling effort will move 

closer to the ―one atmosphere‖ air quality modeling perspective (i.e., ozone and fine 

particles simulated with the same model). The successful application of this prognostic 

model is critical for the development of multipollutant control strategies. Several MM5 

initialization fields and data ingest options are also being explored for the 2007 AQMP 

modeling effort:43

• MM5 model initialized with the National Centers for Environmental Prediction (NCEP) 12 km 

ETA/North American Model (NAM);

• MM5 model with Aerospace Corp 3DVAR forecast fields;

• Weather Research and Forecasting (WRF) community model using Aerospace

Corporation 3DVAR;

• MM5 model with NCEP database of upper air and surface observations and the

 

41 2007 AQMP, Appendix V, Attachment 3.

42 2007 AQMP, Appendix V, Attachment 3, p. 13.

43 2007 AQMP, Appendix V, Attachment 3, p. 24.
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1degree by 1 degree Global Tropospheric Analysis

• Above method of MM5 with NCEP database and Global Tropospheric Analysis and fourdimensional data assimilation (FDDA) of AQMD station meteorological data (this method is 

more mass consistent, but may be difficult to capture localized wind impacts (e.g., transport to 

San Fernando Valley);

• Hybrid CALMET with MM5 as background field

Meteorological Modeling Domain

Nested domains of 15 km and 5 km are defined within MM5 to simulate meteorological 

fields for the fine grid scale of the modeling domain. The modeling domain for MM5 is 

defined in a Lambert-Conformal projection with two parallels to account for curvature of 

the Earth within the modeling domain over such a large region. Figure 1 shows the nested 

MM5 domains. Figure 2 shows the finest scale (interior) MM5 domain, covering most of 

southern California. The vertical structure of MM5 is defined in a terrain-following, 

―sigma‖ coordinate system based upon a normalized pressure index. The 30 vertical 

layers defined for MM5 to approximately 15,000 m above ground level (AGL) can be 

transformed to fit the requirements of any air quality model. The MM5 meteorological 

fields are converted from Lambert-Conformal projection to UTM coordinates for input 

into the air quality models.
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Figure 1: Nested MM5 Domains44

The horizontal grid resolution of the outermost domain is 45 km, for the middle domain is 15 

km, and for the fine scale domain is 5 km.

Vertical Resolution

For the terrain-following MM5 model, the proposed vertical layer consists of 34 layers to 

a height of over 15,000 meters AGL,(as shown in Table 6, Vertical Structures for the 

CAMx Ozone and PM Simulations with Corresponding MM5 Meteorological Model 

Layers, below). For input into the air quality model, the 34 layers are reduced to match 

the vertical resolution of the ozone or particulate matter air quality.45 

 

44 South Coast 2007 AQMP, Appendix V, Attachment 3, p. 30.

45 South Coast 2007 AQMP, Appendix V, Attachment 3, p. 33.
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Qualitative and Quantitative Analyses

The South Coast 2007 AQMP indicates that Qualitative and Quantitative Analyses for the 

meteorological modeling have been performed.46

Discussion

EPA believes the meteorological model choice, domain, horizontal resolution and vertical 

resolution are appropriate for this application. The South Coast 2007 AQMP discusses 

 

46 South Coast 2007 AQMP, Appendix V, Attachment 3. p. 52
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Qualitative and Quantitative Analysis for the meteorological modeling. The results of the 

analysis should be included in the mid- course correction.

8. Air Quality Model Performance

EPA Recommendations

PM2.5 consists of many components and is typically measured with a 24-hour averaging 

time. The individual components of PM2.5 should be evaluated individually. In fact, it is more 

important to evaluate the components of PM2.5 than to evaluate total PM2.5 itself. Apparent ―good 

performance‖ for total PM2.5 does not indicate whether modeled PM2.5 is predicted for ―the right 

reasons‖ (the proper mix of components). If performance of the major components is good, then 

performance for total PM2.5 should also be good. This section contains some analyses that have 

been found to be particularly useful for PM analyses (such as fractional bias and error). We also 

show examples of some new types of display plots such as ―soccer plots‖ and ―bugle plots‖. 

Soccer plots provide a convenient way to display a summary of model performance (including 

bias and error at the same time). Bugle plots have variable bias and error goals, based on ambient 

concentrations. This allows for a higher percentage error and bias at very low concentrations. 

This recognizes the fact that models often have difficulty in accurately predicting near 

background concentrations. It may be useful to prioritize examination of model performance 

within and near the non-attainment area(s) of interest. Additionally, priority may be placed on 

examination of the days that are potentially used in the attainment test (the days > 65 ug/m3 for 

24-hour PM2.5).

Statistics: We recommend calculating statistics for components of PM2.5, and PM precursors. 

Useful metrics include mean fractional bias and mean fractional error, normalized mean bias, 

and normalized mean error. Formulas for estimating these metrics at an individual monitoring 

site, j, are given in the Guidance. 47 Other statistics such as mean bias, mean error, root mean 

square error, correlation coefficients, etc. should also be calculated to the extent that they provide 

meaningful information and defined in Appendix A of the Guidance. Appendix B provides a 

summary of recent model performance evaluations conducted by other modeling groups.

• Mean Fractional Bias (percent): Normalized bias can become very large when a minimum 

threshold is not used. Fractional bias is used as a substitute. The fractional bias for cases with 

factors of 2 under- and over-prediction are -67 and + 67 percent, respectively (as opposed to -50 

and +100 percent, when using normalized bias).Fractional bias is a useful indicator because it 

has the advantage of equally weighting positive and negative bias estimates. The single largest 

disadvantage is that the predicted concentration is found in both the numerator and denominator.

• Mean Fractional Error (percent): Normalized error can become very large when a minimum 

threshold is not used. Therefore fractional error is used as a substitute. It is similar to the 

fractional bias except the absolute value of the difference is used so that the error is always 

positive.

 

47 Guidance p. 202-207.
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• Normalized Mean Bias (percent): This performance statistic is used as a normalization to

facilitate a range of concentration magnitudes. This statistic averages the difference (model -

observed) over the sum of observed values. Normalized mean bias is a useful model performance 

indicator because it avoids over inflating the observed range of values. 

• Normalized Mean Error (percent): This performance statistic is used as a normalization of 

the mean error to facilitate a range of concentration magnitudes. This statistic averages the 

difference (model - observed) over the sum of observed values. Normalized mean error is a 

useful model performance indicator because it avoids overinflating the observed range of values.

Averaging Times: Since modeling for the PM2.5 NAAQS and regional haze will likely require 

modeling different times of year, season-specific statistics and graphic displays are helpful for 

evaluating and diagnosing model performance. Statistics and graphics can be averaged for 

various time scales. For example, statistical metrics and scatter plots can show daily averaged 

ambient modeled pairs, monthly averaged pairs, quarterly (or seasonal averaged) pairs, or annual 

average pairs. Each of these averaging times can provide useful information. We recommend a 

range of different averaging times for annual or seasonal modeling. At a minimum, States should 

examine daily averaged pairs and seasonal (or quarterly) averaged pairs. It should be noted that 

statistics and plots tend to look ―better‖ as the averaging time increases from daily to monthly to 

quarterly to annual. As such, daily pairs should always be examined to ensure a detailed look at 

model performance on the time scale of the FRM and STN measurements (24-hour average).

South Coast 2007 AQMP

Model Performance Statistics are presented in the South Coast 2007 AQMP, Appendix V, pages 

V-2-26 through V-2-47 and in Appendix V, Attachment 2. A summary of the air quality model 

performance is presented below.

PM2.5 Component Species Performance Evaluation for the MATES-III Sites

In general, nitrate and ammonium tend to be over predicted by an average 2 μg/m3 or less 

at most sites. Ammonium model performance at Rubidoux and Fontana are 

approximately within 35 percent of observations and within 20 percent or less for nitrate. 

On average, sulfate is nominally under-predicted however; OC and EC are well simulated 

at all stations. Model performance for the crustal-others category indicates an average 

over-prediction of about 1 μg/m3 or 25 percent above observations. Overall, the 

prediction of total mass reflects the model performance for ammonium, nitrate and the 

others with a tendency for over-prediction at about an average level of 4 μg/m3 or 

approximately 20 percent above observations. 48

 

48 South Coast 2007 AQMP, Appendix V, p. V-2-25.
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Table V-2-11b: CAMx 2005 Base Year Nitrate Model Predictions (μg/m3)

Table V-2-11g: CAMx 2005 Base Year Total Mass Model Predictions (μg/m3)

Annual Average SSI Mass Performance Evaluation

In general, the 2005 base year simulations over-predict observed PM2.5 measurements by 

the FRM methodology. The over prediction is greatest in the western Basin, in particular 

metropolitan Los Angeles County. Over prediction in the San Gabriel Valley and eastern 

Basin is within 60 percent of observations (with the exception of Big Bear Lake which is 

significantly under-predicted.) Southern Orange County, Ventura County and the 

northern desert stations are reasonably well simulated.49

 

49 South Coast 2007 AQMP, Appendix V, V-2-47.
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Table V-2-12: CAMx Predicted and FRM Observed 2005 Base-Year Annual Average 

PM2.5

50

Discussion

EPA believes that model performance was adequate. 

9. Modeled Attainment Test

a. PM2.5 Annual NAAQS

South Coast 2007 AQMP

SMAT Annual PM2.5 Attainment Demonstration

As previously outlined, the SMAT is conducted on a quarterly basis using the CAMx 

model output for the six species from the 2005 base-year and the 2014 controlled 

emissions. Quarterly RRFs determined from the modeling are applied to the MATESIII/Sandwich modified quarterly design value component species. Bonded water is 

calculated from the concentrations of ammonium, nitrate and sulfate using the AIM 

polynomial regression equation. Bonded water is not directly reduced by an RRF but is 

recalculated after applying the RRFs to the ammonium, sulfate and nitrate. Finally, the 

blank is added to the mass. Tables V-2-15a through V-2-15c provide the 2014 baseline 

PM2.5 air quality at the eight key sites, the predicted PM2.5 based on the CARB emissions 

reduction plan and the estimation of the 2015 controlled annual average PM2.5 adding the 

District‘s emissions reduction overlay to the CARB plan. Without implementing any 

additional controls, PM2.5 concentrations at the key sites will not meet the federal 

standard by 2015. Regional concentrations of PM2.5 will be lower with implementation 

of the CARB plan however the maximum predicted PM2.5 concentration, will continue to 

 

50 South Coast 2007 AQMP, Appendix V, p. V-2-47.
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exceed the federal standard by approximately four (4) percent. With implementation of 

the District overlay to the CARB plan, all stations will meet the federal standard of 15.0 

μg/m3. The PM2.5 annual attainment demonstration calculations using the SMAT and 

RRFs are provided in Tables V-A- 1a through V-A-1h in Attachment A. 51

2014 Predicted Baseline PM2.5

52

2014 Predicted PM2.5 with CARB Measures

2014 Predicted PM2.5 with CARB Measures and District Overlay

 

51 South Coast 2007 AQMP, Appendix V, p. V-2-52.

52 South Coast 2007 AQMP, Appendix V, p. V-2-53.
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b. 24 Hour NAAQS

South Coast 2007 AQMP

The 2007 AQMP 2005 Basin maximum design value (64.8 μg/m3) meets the federal 24-

hour average PM2.5 standard of 65 μg/m3. The SMAT for the 24-hour standard is 

presented to assure that the PM2.5 episodic levels continue to lower and that the Basin 

continues to meet the standard in 2015 and beyond. Six methods are discussed in the 

2007 AQMP and applied to the Sandwich modified MATES-III quarterly design values 

and episodic PM2.5 data to quantify future year PM2.5 reductions. 53

Episodic 24-Hr Average PM2.5 Modeling Approach

Per our PM2.5 guidance, two options are provided to determine RRFs for the future year 

24- hour average PM2.5 attainment demonstration. The first option uses episodic 

modeling with day-specific emissions for representative meteorological episodes to 

calculate RRFs and apply the RRF to the design value. The second approach proposed by 

EPA relies on an average response to implementation of emissions control for the top 25 

percentile of days in each quarter of the annual model simulation. The maximum 24-hour 

PM2.5 design value (based on 2003-2005 data) for the Basin (64.8 μg/m3) meets the 

current federal standard. Of great interest is how will the 24- hour PM2.5 concentration 

fare compared to the new standard of 35 μg/m3 when that standard become effective in 

2010. On the basis of our initial simulations and analysis, the District staff feels that the 

future design calculation based on the top 25 percentile day, quarterly is more 

 

53 South Coast 2007 AQMP, Appendix V, p. V-2-54.
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conservative than the episodic modeling. AQMD recommends the use of the 25 

percentile approach. 54

Episodic Simulations

The first approach to determine future year 24-hour maximum or 98th percentile PM2.5

impacts relied on the simulation of one or more representative peak PM2.5 episodes where 

observed concentrations exceed 65 μg/m3. The peak PM2.5 24-hour average concentration 

observed in the Basin during the 2005 MATES-III monitoring program (110 μg/m3 at 

Rubidoux) occurred on October 22, 2005. Episode specific emissions for the peak and 

preceding days were temperature and humidity corrected and MM5/FDDA simulations 

were generated to provide the meteorological input.55

Quarterly Top 25 Percentile

For this approach, the 2005 observational data are sorted by quarter of year and further 

into the top 25 percent of days in each quarter. PM2.5 RRFs are calculated on a quarterly 

basis from the future and base year annual simulations for only those days in the top 25 

percentile per quarter. The quarterly RRFs for the ―top 25 percent days‖ are then applied 

to the quarterly 24-hour average PM2.5 design values to develop quarterly future year 

design values which are later aggregated into an annual 24-hour future year design value 

to assess attainment. (The measured quarterly 24-hour average PM2.5 design values were 

comprised of the 98th percentile data in each quarter for the years 2003, 2004 and 2005). 

Several variations of the episodic and quarterly top 25 percentile future year calculations 

were conducted and are presented and discussed in Chapter 2.56

Table V-2-16: Summary of Methodologies to Calculate 2015 24-Hour Average Design Value 

(μg/m3)57 presents the results of the six tests at eight sites in the basin. The maximum value for 

any monitoring site for any method is 56.6 μg/m3at Compton. All of the tests demonstrate 

continued attainment of the 24-hour average PM2.5 standard of 65 μg/m3in 2015.

 

54 South Coast 2007 AQMP, Appendix V, p. V-1-9.

55 South Coast 2007 AQMP, Appendix V, p. V-1-9.

56 South Coast 2007 AQMP, Appendix V, p. V-1-9.

57 South Coast 2007 AQMP, Appendix V, p. V-2-58.
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c. Unmonitored area analysis

EPA Recommendations

An additional review is necessary, particularly in nonattainment areas where the ozone or 

PM2.5 monitoring network just meets or minimally exceeds the size of the network required to 

report data to Air Quality System (AQS). This review is intended to ensure that a control strategy 

leads to reductions in ozone or PM2.5 at other locations which could have baseline (and future) 

design values exceeding the NAAQS were a monitor deployed there. The test is called an 

―unmonitored area analysis‖. The purpose of the analysis is to use a combination of model output 

and ambient data to identify areas that might exceed the NAAQS if monitors were located there.

The unmonitored area analysis should identify areas where future year design values are 

predicted to be greater than the NAAQS. The unmonitored area analysis for a particular 

nonattainment area is intended to address potential problems within or near that nonattainment 

area. The analysis should include, at a minimum, all nonattainment counties and counties 

surrounding the nonattainment area (located within the State). In order to examine unmonitored 

areas in all portions of the domain, it is recommended to use interpolated spatial fields of 

ambient data combined with gridded modeled outputs.58

Gradient adjusted spatial fields are first created for the base year. Future year estimates can then 

be created by applying gridded RRFs to the gradient adjusted spatial fields. The basic steps are 

as follows:

 

58 Guidance p. 30.
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1) Interpolate base year ambient data to create a set of spatial fields.

2) Adjust the spatial fields using gridded model output gradients (base year values).

3) Apply gridded model RRFs to the gradient adjusted spatial fields.

4) Determine if any unmonitored areas are predicted to exceed the NAAQS in the future.

South Coast 2007 AQMP

2015 CAMx Grid-Cell Evaluation

Figure V-2-15 presents the grid cell extrapolated of 2005 PM2.5 annual design values. 

Only grid cells over the federal standard are darkened. Extrapolation was based on distance 

weighted interpolation scheme using design values from sites inside and outside the Basin to 

enhance the spatial representation. The pattern depicted by the grid cell design display closely 

matches the pattern of annual average PM2.5 presented in Figure V-2-3, in the AQMP.

Using a similar interpolation scheme, the relative percentage contributions of the six 

component species at the eight MATES-III sites was extrapolated to each cell in the basin. 

Predicted 2015 PM2.5 concentrations at the grid cell level (without using multi-cell averaging) 

was estimated each grid cell by multiplying the speciated RRFs from the CAMx simulations by 

the relative percentage concentrations of the six components contributing to the grid cell mass 

and the interpolated grid cell design value. Figure V-2-16 presents the 2015 baseline distribution. 

PM2.5 levels will be reduced regionally with implementing additional control measure however, 

almost 60 percent of the population of the Basin will continue to breathe air quality above the 

federal standard. With the Final South Coast 2007 AQMP control strategy in place no cells in the 

South Coast PM2.5 nonattainment area will be above the federal standard.59

Discussion

EPA believes the 2015 CAMx Grid-Cell Evaluation analysis adequately addresses the 

EPA‘s recommendation to perform a test to ensure that a control strategy leads to reductions in 

PM2.5 at other locations which could have baseline (and future) design values exceeding the 

NAAQS were a monitor deployed there. 

d. Attainment Date Extension

South Coast 2007 AQMP

Under the federal Clean Air Act, the Basin must comply with the federal PM2.5 air quality 

standards by April, 2010 [Section 172(a)(2)(A)]. An extension of up to five years could 

be granted if attainment cannot be demonstrated and several other conditions are 

satisfied. A simulation of 2010 annual average PM2.5 was conducted to substantiate the 

severity of the PM2.5 problem in the Basin. The simulation used the projected emissions 

for 2009 which included all existing and adopted control measures that will be 

implemented prior to 2010. The resulting 2010 future-year design value (17.9 μg/m3) 

failed to meet the federal standard. As a consequence and as indicated in Chapter 1, the 

 

59 South Coast 2007 AQMP, Appendix V, p. V- 2-54, V-2-55
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District is formally requesting U.S. EPA to grant the five-year extension based upon the 

severity of the problem and the modeled attainment demonstration that clearly indicates 

that significant reductions in daily emissions of PM2.5, NOx, VOC and SOx are required 

to meet the 2015 attainment date.60

Discussion

EPA believes that the South Coast 2007 AQMP modeling provided in the 2007 AQMP is 

adequate to support the District‘s conclusion that the annual PM2.5 standard will not be met in 

2010.

10. Weight of Evidence

EPA Recommendations

States/Tribes should always perform complementary analyses of air quality, emissions 

and meteorological data, and consider modeling outputs other than the results of the attainment 

test. Such analyses are instrumental in guiding the conduct of an air quality modeling 

application. Sometimes, the results of corroboratory analyses may be used in a weight of 

evidence determination to show that attainment is likely despite modeled results which may be 

inconclusive. The further the attainment test is from being passed, the more compelling contrary 

evidence produced by corroboratory analyses must be to draw a conclusion differing from that 

implied by the modeled attainment test results.61

 

60 South Coast 2007 AQMP, Appendix V, p. V-2-48.

61 Guidance p. 17.
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Discussion

The modeled attainment test predicted a 2014 annual concentration of 15.0 μg/m3

Rubidoux.

62

 Based on the table, Guidelines for a Weight of Evidence Determination, above, a 

weight of evidence determination is recommended to determine if additional analyses support the 

modeled attainment test. EPA guidance lists three types of analyses that are recommended for 

this demonstration: 1) additional modeling, 2) analyses of trends in ambient air quality and 

emissions, and 3) observational models and diagnostic analyses.63 The consistent improvement 

in ambient PM2.5 concentrations throughout the South Coast air basin and the expected 

continuing emissions decreases that are described in the South Cast Plan both indicate that the 

modeled attainment test results are reasonable.

WOE: trends in ambient air quality and emissions 

The weight of evidence from the South Coast AQMP supports the air quality modeling, 

which indicates the basin will attain the annual PM2.5 standard by 2015.

The District states that the emissions reductions expected from 2005 to 2014 are 

consistent with the reductions observed from 2002 to 2005. 64 The District argues that given 

these expected continuing emissions reductions, and the observed trend at four monitoring 

stations of 4.5 percent annual improvement rate, the basin is projected to reach attainment by 

2015. 65 The WOE in the South Coast 2007 AQMP also discusses population and industrial 

growth and re-distribution, as well as port control strategy and CARB measures.66 

Data from 2006 to 2009 reflect a smaller annual rate of improvement of ambient PM2.5

concentration than the observed rate from 1999 through 2006, as show in the table below. Note 

that only sites with complete data are presented in the table. 

 

62 South Coast 2007 AQMP, Appendix V, p. V-2-53.

64 South Coast 2007 AQMP, Appendix V, p. V-2-60-61.

65 South Coast 2007 AQMP, Appendix V, p. V-2-60-61.

66 South Coast 2007 AQMP, Appendix V, p. V-2-59.
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Annual PM2.5 design value for SCAQMD Sites (μg/m3) 
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I-710 Air Monitoring Study

The District conducted the I-710 Air Monitoring Study to investigate near roadway 

concentrations, understand trends for future control strategies, validate dispersion models, and 

understand community exposures in near roadway environments. To meet these objectives, 

SCAQMD conducted daily monitoring PM2.5 mass using federal reference methods (FRM) 

during approximately one month in the winter (February –March 2009) and approximately one 

month during the summer (July – August 2009) at three sites. 

The sites were 15m and 80m downwind of the freeway and several miles upwind of the 

freeway (as a background measurement). During the two month-long intensive study periods, the 

District also performed twenty-four-hour filter measurements of TSP lead, PM10 mass, elemental 

carbon (EC) and organic carbon (OC) in PM10 every other day. VOC Air Toxics were measured 

in four intervals starting at 5 a.m. (4, 6, 4, and 10-hr intervals) every other day and continuous 

measurements of ultrafine particle number (UFP), black carbon (BC), PM2.5mass (non-federal 

equivalent method (FEM)), NOx, and meteorological parameters were also conducted.

Preliminary results from the study indicate that during the winter monitoring period, and 

PM2.5 values at the 15 meter, 80 meter, and N Long Beach (background) sites were12.6 μg/m3, 

11.5 μg/m3, and 9.59 μg/m3, respectively. During the summer monitoring period, and PM2.5 

values at the 15 meter, 80 meter, and N Long Beach (background) sites were 15.2 μg/m3, 14.0
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μg/m3, and 12.7 μg/m3, respectively. These preliminary results in the presentation

―Preliminary Results from the AQMD I-710 Air Monitoring Study,‖ which is available at:

http://www.metro.net/projects_studies/I710/images/AQMD-I-710-Air-Monitoring-Study-toCAC-February-2010.pdf

Final study results are not yet available. It is important to note that the duration of the 

study was shorter than what is required to show NAAQS attainment and is therefore not able to 

be a direct estimate of the expected value in a near-roadway environment. However, the study 

area includes the most congested highway in the South Coast basin, and therefore, the results 

likely provide a worst case scenario and do show an incremental decrease in PM2.5

concentrations with distance to roadways. SCAQMD continues to monitor BC and NOx at the 

15m site to learn more about the interplay between air quality, meteorology and traffic emissions 

in the complex near-roadway environment. 

The current 24-hour PM2.5 design value for the South Coast Air Basin is 41 μg/m3.

67

 The 

maximum modeled future year value of 24 hour PM2.5 NAAQS in the South Coast Basin, 

discussed above, is 56.6 μg/m3at Compton.

68

 Based on current monitored and future modeled 

data, EPA believes the 24 hour PM2.5 mass will continue to be well below 65 μg/m3. 

11. Proposed Actions on Air Quality Modeling in the South Coast 2007 AQMP

In our November 2010 proposal and our July 2011 amended proposal, we proposed to 

find that the air quality modeling in the South Coast 2007 AQMP meets the requirements of the 

CAA consistent with EPA guidance, and that that the modeling provides an adequate basis for 

the PM2.5 reasonably available control measure, reasonable further progress, and attainment 

demonstrations in the South Coast 2007 AQMP. See 75 FR 71294, at 71305, and 76 FR 41562, 

at 41573.

12. Evaluation and Conclusion

The modeling used for the attainment demonstration was made available to the public for 

comment at the same time as the draft 2007 PM2.5 plan, and was subject to public hearing as part 

of final version of the Plan. 

 The air quality modeling documentation in Appendix V of the South Coast 2007 AQMP 

contains all the elements required by EPA‘s modeling guidance. The modeling is based on the 

best and most current information available at the time the South Coast 2007 AQMP was 

developed. Based on our evaluation, discussed above, we find that the modeling analysis used 

for the attainment demonstration in the South Coast 2007 AQMP for attainment of the 1997 

PM2.5 NAAQS meets the CAA section 172(c)(1) requirement that the plan ―shall provide for 

attainment of the national primary ambient air quality standards‖ at the time of their submittal in 

2007, and that the modeling in the South Coast 2007 AQMP provides an adequate basis for the 

 

67 See footnotes 3 and 4.

68South Coast 2007 AQMP, Appendix V, p. V-2-58.
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PM2.5 reasonably available control measure, reasonable further progress, and attainment 

demonstrations in the South Coast 2007 AQMP. 

We received a number of comments on our proposed finding on the air quality modeling. 

We have reviewed these comments and provided responses to them. See section III of this TSD. 

No issues raised in these comments changed our finding that the air quality modeling in the 

South Coast 2007 AQMP and revised 2007 State Strategy are consistent with the applicable 

requirements of the CAA and EPA guidance.
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C. PM2.5 Attainment Plan Precursors

1. Requirements for the Control of PM2.5 Precursors

EPA recognizes NOx , SO2,VOC, and ammonia as precursors of PM2.5 because these 

pollutants can contribute to the formation of PM2.5 in the ambient air. As discussed previously, 

states must include each in their submitted emissions inventory in order to assure the information 

on all pollutants and precursors that contribute to PM2.5 concentrations is available. 72 FR 20586 

(April 25, 2007), at 20589 and 40 CFR § 51.1008(a)(1). However, the overall contribution of 

different precursors to PM2.5 formation, and the effectiveness of alternative potential control 

measures, will vary by location. Thus, the precursors a state should regulate for attaining the 

PM2.5 NAAQS will also vary to some extent from area to area.72 FR 20586, at 20589.

As discussed previously, states must submit emissions inventories for each of the four 

PM2.5 precursor gases in order to assure the information on all pollutants and precursors that 

contribute to PM2.5 concentrations is available. 72 FR 20586, at 20589 and 40 CFR § 

51.1008(a)(1). However, the overall contribution of different precursors to PM2.5 formation, and 

the effectiveness of alternative potential control measures will vary by location. Thus the 

precursors a state should regulate for attaining the PM2.5 NAAQS will also vary to some extent 

from area to area. 72 FR 20586 at 20589.

In the PM2.5 implementation rule, EPA did not make a finding that all potential PM2.5

precursors must be controlled in each specific nonattainment area. See 72 FR 20586 at 20589. 

Instead, for reasons explained in the rule, a state must evaluate control measures for sources of 

SO2 in addition to sources of direct PM2.5 in all nonattainment areas. 40 CFR § 51.1002(c) and 

(c)(1). A state must also evaluate control measures for sources of NOx unless the state and/or 

EPA determine that controls on sources of NOx emissions would not significantly reduce PM2.5

concentrations in the specific nonattainment area. 40 CFR § 51.1002(c)(2). By contrast, EPA 

has determined in the PM2.5 implementation rule that a state does not need to address controls for 

sources of VOC and ammonia unless the state and/or EPA make a technical demonstration that 

such controls would significantly contribute to reducing PM2.5 concentrations in the 

nonattainment area. 40 CFR §51.1002(c)(3) and (4). Such a demonstration is required ―if the 

administrative record related to the development of its SIP shows that the presumption is not 

technically justified for that area.‖ 40 CFR § 51.1002(c)(5)

―Significant contributor‖ in this context means that a significant reduction in emissions of 

the precursor from sources in the area would be projected to provide a significant reduction in 

PM2.5 concentrations in the nonattainment area. 72 FR 20586, at 20590. Although EPA did not 

establish a quantitative test for determining the significance of such a change, EPA noted that 

even relatively small reductions in PM2.5 concentrations are estimated to result in worthwhile 

public health benefits. Id.

2. Identification of PM2.5 Attainment Plan Precursors in the South Coast 2007 AQMP

and EPA‘s Evaluation

The 2007 South coast AQMP does not explicitly identify the pollutants that have been 

selected as ―PM2.5 attainment plan precursors as defined in and 40 CFR § 51.1000. The plan 
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addresses NOx, direct PM2.5, SOx, and VOC in the RFP and attainment demonstrations and the 

District‘s RACM/RACT analysis and thereby implicitly identifies NOx, SOx, and VOC as 

attainment plan precursors. The South Coast PM2.5 attainment demonstration addresses 

ammonium nitrate and ammonium sulfate since they represent a dominant fraction of PM2.5

components and are formed through secondary reactions of the precursors NOx, SOx, and 

ammonia. Ammonium nitrate and ammonium sulfate are controlled through the control of NOx 

and SOx as precursors.

In the South Coast Air Basin, PM2.5 can be directly emitted, such as from road dust, 

diesel soot, combustion products, and other sources (―primary particles‖), or formed through 

atmospheric chemical reactions of precursor gases (―secondary particles‖). Examples of 

secondary particles include sulfates, nitrates, and complex carbon compounds formed from 

reactions of NOx, SOx, VOCs, and ammonia. The District‘s analysis indicates that SOx 

reductions followed by directly-emitted PM2.5 and NOx reductions provide the greatest ambient 

PM2.5 reductions. VOC reductions can also contribute to improving ambient PM2.5 concentrations 

and will occur concurrently as a result of the District‘s 8-hour ozone strategy.69

The PM2.5 Implementation Rule allows States or EPA to evaluate which PM2.5 precursors 

should be precursors for regulatory purposes in a particular nonattainment area, based on the 

facts and circumstances of such area. South Coast has elected to consider VOCs as regulatory 

precursors for the purpose of this SIP, based on their modeling analysis which considered the 

sensitivity on PM2.5 formation to VOC emission reduction. EPA agrees that the District‘s 

determination to consider VOC as a precursor for this SIP is appropriate in this nonattainment 

area.

3. Proposed Concurrences on PM2. Precursors

In our November 2010 proposal and July 2011 amended proposal, we proposed to concur 

with the State‘s election to control direct PM2.5, and NOx, SOx and VOC as attainment plan 

precursors in the South Coast 2007 AQMP to reach attainment of the 1997 PM2.5 NAAQS. See 

75 FR 71294, at 71305, and 76 FR 41562, at 41574.

4. Evaluation and Conclusion

EPA concurs with the State‘s election to control direct PM2.5, and NOx, SOx and VOC as 

attainment plan precursors in the South Coast 2007 AQMP to reach attainment of the 1997 PM2.5

NAAQS. 

We received several comments on our proposed concurrence on the State‘s election to 

control direct PM2.5, NOx, SOx, and VOCs. We have reviewed these comments and provided 

responses to them. See section III of this TSD. No issues raised in these comments changed our 

concurrence with the State‘s election to control direct PM2.5, and NOx, SOx and VOC as 

attainment plan precursors in the South Coast 2007 AQMP to reach attainment of the 1997 PM2.5

NAAQS. 

 

69 South Coast 2007 AQMP, page 5-17.
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D. Reasonably Available Control Measures/Reasonably Available Control 

Technology

1. Requirements for RACM/RACT

CAA section 172(c)(1) requires that each attainment plan ―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 [RACT]), and 

shall provide for attainment of the national primary ambient air quality standards.‖ 

We interpret reasonably available control measures (RACM) in CAA section 172(c)(1) as 

referring to measures of any type that may be applicable to a wide range of sources, whereas the 

parenthetical reference to reasonably available control technology (RACT) refers to measures 

applicable to stationary sources. Thus, RACT is a type of RACM specifically designed for 

stationary sources. 72 FR 20586 at 20610.

EPA defines RACM as any potential control measure for application to point, area, onroad and non-road emissions source categories that meets the following criteria: the control 

measure is (1) technologically feasible, (2) economically feasible, (3) does not cause ―substantial 

widespread and long-term adverse impacts‖, (4) is not ―absurd, unenforceable, or impracticable‖, 

and (5) collectively can advance the attainment date by at least one year. 72 FR 20586 at 20610 

We define RACT as the lowest emission limitation that a particular stationary source is capable 

of meeting by the application of technology (i.e., devices, systems, process modifications, or 

other apparatus or techniques that reduce air pollution) that is reasonably available considering 

technological and economic feasibility. 72 FR 20586 at 20610.

For PM2.5 attainment plans, EPA is requiring a combined approach to RACM and RACT 

under subpart 1 of Part D of the CAA. Under this approach, RACM/RACT are measures that a 

state finds are both reasonably available and contribute to attainment as expeditiously as 

practicable in its nonattainment area. Thus, what constitutes RACM/RACT in a PM2.5

attainment plan is closely tied to that plan‘s expeditious attainment demonstration.40 CFR §

51.1010; 72 FR 20586 at 20612. By definition, measures that are neither necessary for meeting 

the RFP requirement nor help an area attain the NAAQS as expeditiously as practicable are not 

required RACM/RACT. A state‘s attainment plan must include a list of measures considered 

and information sufficient to show that a state has met all requirements for determination of 

RACM/RACT. 72 FR 20586 at 20612. A state must evaluate RACM/RACT for each identified 

PM2.5 attainment plan precursor.

Under this combined approach, EPA considers RACT be part of an area's overall RACM 

obligation. Subpart 1, unlike subparts 2 and 4 of title 1, Part D of the CAA, does not identify 

specific source categories for which EPA must issue control technology documents or guidelines 

for what constitutes RACT or identify specific source categories for state evaluation during 

attainment plan development. 72 FR 20586 at 20610. Because of the variable nature of the PM2.5 

problem between nonattainment areas, which may require states to develop attainment plans that 

address widely disparate circumstances, EPA determined that a state should have flexibility with 

respect to RACT and RACM controls but also that in areas needing significant emission 
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reductions to attain the PM2.5 standards, RACM/RACT controls on smaller sources may be 

necessary to reach attainment as expeditiously as practicable. PM2.5 implementation rule 

preamble at 20612, 20615

The determination of RACM/RACT is a three-step process: (1) identifying 

technologically and economically feasible measures and associated emissions reductions, (2) 

conducting air-quality modeling and related analyses, and (3) selecting RACM/RACT. 72 FR 

20586 at 20613. Any measures that are necessary to meet these requirements which are not 

already either federally promulgated, part of the state‘s SIP, or otherwise creditable in SIPs must 

be submitted in enforceable form as part of a state‘s attainment plan for the area. 72 FR 20586 at 

20614.

The first step, identification of potential measures, should be based on an inventory of 

emissions of direct PM2.5 and PM2.5 attainment plan precursors from the range of relevant 

sources and source categories. 72 FR 20586 at 20613. A state is required to evaluate 

RACM/RACT for direct PM2.5 and SO2. A states is also required to evaluate RACM/RACT for 

NOx sources unless it finds that such sources do not significantly contribute to the PM2.5 levels in 

its nonattainment area. 72 FR 20586, at 20613. Significantly contribute in this context means 

that a significant change in emissions of the precursor from sources in the area would be 

projected to provide a significant change in PM2.5 concentrations in the area. 72 FR 20586 at 

20590.

In the preamble to the PM2.5 implementation rule, EPA provided a recommended list of 

the types of source categories and control measures that may be appropriate for evaluation given

the local source mix and attainment needs of a specific area 72 FR 20586 at 20621.

Technological feasibility refers to whether there are available measures capable of 

reducing emissions of PM2.5 or PM2.5 precursors or both. A number of factors are considered in 

this analysis, such as process and operating conditions, raw materials, physical plant layout, nonair quality and energy impacts, and the time needed to install and operate controls. 72 FR 20586

at 20618.

Economic feasibility refers to whether the cost of a measure is reasonable for the source

or source category. A number of factors are considered in this analysis, such as cost per ton of 

pollution reduced, capital costs and annualized cost. 72 FR 20586 at 20619.

2. RACM/RACT Analysis in the South Coast 2007 AQMP

The South Coast 2007 AQMP and the revised 2007 State Strategy are the latest in a 

series of air quality plans that the District and CARB have developed to provide for attainment of 

the federal air quality standards in the South Coast nonattainment area.70 These planning efforts 

have resulted in a comprehensive set of rules and programs that address the great majority of 

 

70 These plans include the 2003 PM10 Plan (approved 70 FR 69081, November 10, 2005), the 2003 AQMP 

addressing the 1-hour ozone standard (partially approved at 74 FR 10176, March 10, 2009), the 2003 State Strategy 

(portions that address the South Coast 1-hour ozone standard partially approved at 74 FR 10176, March 10, 2009)

and the South Coast 2007 AQMP (submitted November 28, 2007). 
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emissions in the South Coast nonattainment area. Many of these District and state rules are 

among the most stringent in the nation.

For the South Coast 2007 AQMP and the revised 2007 State Strategy, the District, CARB 

and the Southern California Association of Governments (SCAG), the South Coast metropolitan 

planning organization (MPO) for the area, each undertook a process to identify and evaluate 

potential RACM that could contribute to expeditious attainment of the PM2.5 standards in the 

South Coast nonattainment area. We describe each agency‘s efforts below. 

a. District RACM/RACT Analysis

The District‘s RACM/RACT analysis and its results are described in Chapter 6 and 

Appendix VI of the 2007 AQMP. The analysis focused on the stationary source and area source 

controls under direct jurisdiction of the District. Since the 1970s, the SCAQMD has adopted 

stationary source control rules that have resulted in significant improvement in air quality in the 

South Coast Air Basin. When command and control rules were no longer within the limitations 

of economic efficiency, the District began using economic inventive approaches with programs 

such as the Regional Clean Air Incentives Market (RECLAIM) and the Carl Moyer program. 

While the District still relies on command and control regulations, the District‘s control 

strategies are now supplemented by market incentives and compliance flexibility approaches 

where appropriate. These regulations and strategies have yielded significant emissions reductions 

from sources under the District‘s jurisdiction. In developing the South Coast 2007 AQMP, the 

District conducted a process to identify RACM for the South Coast which involved public 

meetings to solicit input, evaluation of EPA suggested RACM, and evaluation of other air 

agencies‘ regulations. The District conducted a five step process which is described in detail 

below.

Step 1 - AQMP Summit 

In June 2006, the District conducted a 2007 AQMP Summit. Over 125 attendees including 

experts from a variety of areas and the public provided input on new and innovative approaches

to assist the District in attaining the ambient air quality standards for PM2.5 by 2015. In total, the 

District received about 200 control measure suggestions. In general, District staff was advised to 

1) promote electrification; 2) focus on technology that improves energy efficiency and reduces 

greenhouse gases; 3) influence consumer awareness and choice on low- or zero-VOC products; 

4) incentivize low- or zero-emission control technologies; 5) promote the use of remote sensing 

to detect polluting vehicles on roads and highways, and 6) improve public participation and 

multi-agency collaboration. 

Step 2 - U.S. EPA Suggested List of Control Measures 

EPA published a list of suggested potential RACT and RACM for PM2.5 in the preamble 

to the PM2.5 Implementation Rule (see 72 FR 20586, April 25, 2007). As shown in Table 2 of 

Appendix VI, the District has adopted control measures for each PM2.5 RACT and RACM in the 

preamble to the PM2.5 Implementation Rule. Since the District regulations emissions of VOC and 

NOx for purposes of attaining both the PM2.5 as well as the 1997 8-hour ozone standard, some 

of the identified measures may not be necessary or timely for PM2.5 attainment.
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Step 3 – Control Techniques Guidelines (CTGs) Updated by U.S. EPA in September 2006 

As required in CAA section 172(c)(1) the SIP for a nonattainment area must include 

RACM, including RACT for stationary sources. EPA defines RACT as: 

―the lowest emission limitation that a particular source is capable of meeting by the 

application of control technology that is reasonably available considering 

technological and economic feasibility‖. 44 FR 53762 (September 17, 1979)

Section 182(b)(2) and (f) of the Clean Air Act provide that States must revise their SIP to 

include RACT for VOC sources covered by a Control Techniques Guidelines (CTG) document 

issued by the U.S. EPA after November 15, 1990 and prior to the area‘s date of attainment. The 

CAA requires the EPA to revise RACT, update existing CTG documents, or develop new 

documents, on a frequent basis to provide states and local agencies with most current technical 

information and assist them in determining RACT. In September 2006, EPA updated the CTGs 

for Offset Lithographic and Letterpress Printing, Flexible Packaging Printing, Industrial 

Cleaning Solvents, and Flat Wood Paneling Coatings 

Step 4 - Other Districts’ Current Rules and Regulations 

The District reviewed all rules and regulations recently adopted or amended, from 2000 

to 2006, by San Joaquin Valley, Sacramento, Ventura and San Francisco air districts, 

and compared its rules with analogous requirements in the rules of these other California air 

districts. District staff selected these districts for comparison purposes based on their ozone 

nonattainment classifications.

Table 3 in Appendix VI of the AQMP contains a brief description of the 82 source-specific 

rules that staff analyzed and a summary of more stringent requirements adopted by other 

districts. In addition, Table 3 also includes a description of the control measures adopted by 

other agencies for their own 8-hour ozone plans, and information on advanced technologies or 

U.S. EPA consent decrees that District staff is aware of that may result in additional emission 

reductions. In general, the District‘s current rules and regulations are equivalent to or more 

stringent than those developed by other California air districts, with a few exceptions shown in 

Table 3 where improvements are possible. Therefore, the District developed several control 

measures to address these areas, such as Control Measure MCS-01 – Facility Modernization, 

MCS-07 – Application of All Feasible Measures, and CMB-02 – Reduction of Emissions in 

RECLAIM. Table 3 in Appendix VI identifies these control measures. In general, the areas 

identified for potential improvements are to explore the feasibility of lowering emission limits 

and increasing level of control in order to promote cleaner technologies, lowering VOC content 

of coatings/solvents, establishing standards and test methods for generic control equipment, 

lowering release or leak thresholds, encouraging continuous wireless monitoring, improving leak 

detection, repair, inspection and maintenance, and adding best management practices. 

With respect to technological and economic feasibility, the District assumed that

technologies and measures which are available and cost-effective to implement in other 

air districts in California, would be available and cost-effective for implementation in the South 
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Coast Basin in a timely manner. Best Available Retrofit Control Technology (BARCT) is 

reevaluated every three years. The District refines emission inventory, emission reduction, and 

cost- effectiveness estimates as well as health benefits on an ongoing basis, especially during the 

rule development process. In addition, the District commits to monitor rule development in other 

air districts, and will conduct further study and reevaluate the feasibility of revising the 

requirements in existing rules if necessary. Instead of amending existing rules, new rules may be 

adopted to implement the control measures described in the South Coast 2007 AQMP in a more 

effective manner. Prioritization and schedules for adoption and implementation are discussed in 

Chapter 7 of the AQMP. 

Step 5 - Additional Studies and Analyses 

In addition to the above analyses, the District and SCAG have taken the following actions

to meet the RACM requirements of the CAA:

• Evaluation of control measures developed by other air districts for their air quality 

management plans as described in Appendix IV-A. 

• Analysis of the specific costs of each SCAQMD‘s stationary source and mobile source 

control measure, if available, as provided in Appendix IV-A and B. 

• Development of a schedule for implementing the control measures, as discussed in 

Chapter 7 of the AQMP, which demonstrates that the District will implement the control 

measures as expeditiously as practicable considering resources and budgets. 

• Completion of a SCAQMD 8-Hour Ozone RACT SIP Demonstration project which the 

District submitted to EPA in June 2006 for comment. The District concluded that 1) All 

SCAQMD rules to implement the 1-hour ozone SIP fulfill RACT for the 8-hour ozone SIP, 

and 2) All CTG sources and all major non-CTG sources in the Basin are subject to SIPapproved rules satisfying RACT requirements for the 1997 8-hour ozone standard. EPA 

fully approved the South Coast RACT SIP for the 1997 8-hour ozone standard on 

December 18, 2008 at 73 FR 76947.

District’s Conclusion Regarding RACM

Following is the summary of the District‘s findings: 

The District evaluated all potentially reasonable control measures that were available for 

implementation in the area and inclusion in South Coast 2007 AQMP. 

The control measures in the South Coast 2007 AQMP included all RACM suggested by the 

public and experts.

The control measures in the South Coast 2007 AQMP included all RACT and RACM 

recommended by EPA in the PM2.5 Implementation Rule.
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In general the District‘s rules and regulations are equivalent to, or more stringent 

than, other California districts‘ rules and regulations and their proposed control measures 

in their respective SIPs. In several areas identified in Table 3 of Appendix VI of the 

AQMP, the existing source-specific rules may be amended to lower the emissions 

standards, promote cleaner technologies, add additional best management practices, and 

improve enforceability. District staff will monitor the rule development of other air 

districts, explore all feasible control options, and conduct further analyses to refine the 

emission inventory, emission reductions, and cost-effectiveness analysis. 

The District developed 37 stationary source control measures that contained all measures 

included in other districts‘ air quality management plans. In addition, the District 

developed many innovative stationary source control measures, such as MCS-01 – Facility 

Modernization, CTS-02 - Clean Coating Certification, MCS-07 – Application of All 

Feasible Measures, and FLX-01 – Economic Incentive Programs, that were not included in 

other districts‘ air quality management plans. 

The few available control measures that District staff did not include collectively would 

not advance the attainment date or contribute to RFP for the South Coast PM2.5

nonattainment area because of the insignificant or non-quantifiable amount of emission 

reductions that they would generate. 

The RACM demonstration for transportation control measures (TCMs) is included in 

Appendix IV-C. The District is treating all mobile source control measures provided by 

CARB to SCAQMD RACM. See South Coast 2007 AQMP, Appendix VI, p.VI-7.

Since the submittal of the South Coast 2007 AQMP, the District has adopted a number of 

additional RACM that achieve a portion of the emissions reductions assigned to the District‘s 

enforceable commitments.

b. Local Jurisdiction’s RACM Analysis

The local jurisdiction‘s RACM analysis was conducted by the Southern California 

Association of Governments (SCAG) , the MPO for the Los Angeles region. This analysis, 

which focused on transportation control measures (TCMs), and its results are described in

Appendix IV-C of the South Coast 2007 AQMP. TCMs are generally measures designed to 

reduce emissions from on-road motor vehicles through reductions in vehicle miles traveled 

(VMT) or traffic congestion. 

For the South Coast 2007 AQMP, the RACM demonstration for TCMs is included in 

Appendix IV-C, The TCMs in the South Coast 2007 AQMP are derived from TCM projects in 

the 2006 SCAG Regional Transportation Improvement Program (RTIP). This evaluation, 

described beginning on page 49 of Appendix IV-C of the South Coast 2007 AQMP, resulted in 

extensive local government commitments to implement programs to reduce auto travel and 

improve traffic flow. South Coast 2007 AQMP page 6-6 and Appendix IV-C. SCAG also 

provided reasoned justifications for any measures that it did not adopt. Attachment A to 

Appendix IV-C contains an extensive list of TCMs in process and newly programmed TCMs. 
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c. State’s RACM Analysis 

CARB describes its proposed strategy to reduce emissions from sources within its 

jurisdiction – on- and off-road engines and vehicles, fuels, and consumer products- in Chapter 3 

of the 2007 State Strategy. CARB has unique authority under the CAA to adopt standards for 

most categories of on- and off-road engines and vehicles, subject in most instances to a waiver 

by EPA under CAA section 209.

CARB developed this proposed strategy after an extensive public consultation process to 

identify potential SIP measures. It included a SIP Symposium in October 2006 and a workshop 

in November 2006 to discuss development of potential control concepts for meeting the federal 

8-hour ozone and PM2.5 standards.71 CARB made a draft of the 2007 State Strategy available for 

public review in April 2007 and then conducted a series of public workshops on the draft. On 

April 26, 2007, CARB staff released a revised draft of the Proposed State Strategy that 

incorporated changes based on further staff analysis and public comments. CARB Resolution 07-

28, p. 3.

From this process, CARB identified and committed to propose 15 new defined measures. 

2007 State Strategy, p. 65 and CARB Resolution 07-28, Attachment B, p. 8. These measures 

focus on cleaning up the in-use (legacy) fleet as well as increasing the stringency of emission 

standards for a number of engine categories and further reductions from motor vehicle fuels and 

consumer products. Many if not most of these measures are being proposed and adopted for the 

first time anywhere in the nation. They build on CARB‘s already comprehensive program to 

address emissions of direct PM2.5, NOx, and VOC from all types of mobile sources through both 

regulations and incentive programs, as well as from fuels and consumer products. See 2007 

State Strategy, p. 38. Table D-1 lists these measures and includes one additional measure each 

from the California Bureau of Automotive Repair (BAR) and the California Department of 

Pesticide Regulation (DPR). Table D-2 provides the list of these measures as updated in CARB‘s 

2011 Progress Report.

Table D-1

2007 State Strategy Defined Measures Schedule for Consideration

Defined State Measure Expected Adoption Year

Smog Check Improvements 2007-2008

Expanded Vehicle Retirement 2008-2014

Modification to Reformulated Gasoline Program 2007

 

71 More information on this public process including presentations from the workshops and symposium that 

preceded the adoption of the 2007 State Strategy can be found at 

www.arb.ca.gov/planning/sip/2007sip/2007sip.htm.
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Table D-1

2007 State Strategy Defined Measures Schedule for Consideration

Defined State Measure Expected Adoption Year

Cleaner In-use Heavy Duty Trucks 2008

Auxiliary Ship Cold Ironing and Clean Technologies 2007-2008

Cleaner Main Ship Engines and Fuels Fuels: 2007

Engines: 2009

Port Truck Modernization 2007-2008

Accelerated Introduction of Cleaner Line-Haul 

Locomotives (enforceable agreement) 2007-2008

Clean Up Existing Harbor Craft 2007

Cleaner In-Use Off-Road Equipment 2007

Clearer In-Use Agricultural Equipment 2009

New Emissions Standards for Recreational Boats 2009-2010

Expanded Off-Road Recreational Vehicle Emissions 

Standards By 2010

Enhanced Vapor Recovery for Above Ground Storage 

Tanks 2007

Additional Evaporative Emissions Standards By 2010

Consumer Products Program (I & II) 2007-2008 & 2010-2012

Department of Pesticide Regulation rules 2008

Source: 2007 State Strategy
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Table D-2

Updated 2007 State Strategy: PM2.5 SIP Measures

Defined State Measure Action

Smog Check Improvements 2007-2009

Expanded Vehicle Retirement 2007

Modification to Reformulated Gasoline Program 2007

Cleaner In-Use Heavy Duty Trucks 2007, 2008, 2010

Auxiliary Ship Cold Ironing and Clean Technologies 2007-2008

Cleaner Main Ship Engines and Fuels Fuel: 2008-2011

Engines: 2008

Port Truck Modernization 2007, 2008, 2010

Accelerated Introduction of Cleaner Line-Haul 

Locomotives (enforceable agreement) 2008

Clean Up Existing Harbor Crafts 2007, 2010

Cleaner In-Use Off-Road Equipment 2007, 2010

New Emissions Standards for Recreational Boats Expected 2013

Expanded Off-Road Recreational Vehicle Emissions 

Standards Expected 2013

Enhanced Vapor Recovery for Above Ground Storage 

Tanks 2008

Additional Evaporative Emissions Standards 2009,

Expected 2013

Consumer Products Program (I & II) 2008, 2009, 2011

Department of Pesticides Regulation Pesticide Rule 2008, 2009

Source: 2011 Progress Report, p. 8, Table 1.
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3. Proposed Actions on the RACM/RACT Demonstration

In our November 2010 proposal, EPA proposed to disapprove the RACM/RACT 

demonstration in the South Coast PM2.5 SIP based on our proposed disapproval of the attainment 

demonstration and proposed denial of California‘s attainment date extension request. 

We noted in our November proposed disapproval that is appeared that the State, District, 

and local jurisdictions had identified and otherwise provided for the implementation of a 

comprehensive set of measures that are among the most stringent in the nation and should the 

District and State correct the deficiencies in the attainment demonstration, we would most likely 

be able to approve the SIP‘s RACM/RACT demonstration. 75 FR 71294 at 71304.

In our July 2011 amended proposal, we proposed to approve the RACM/RACT 

demonstration in the South Coast PM2.5 SIP based on our proposed approval of the attainment 

demonstration and proposed granting of California‘s attainment date extension request. 76 FR 

41562, at 41572.

4. EPA‘s Evaluation and Conclusion

Under the PM2.5 implementation rule, RACM/RACT are the set of measures necessary 

for expeditious attainment in a specific nonattainment area. The measures must address 

emissions of PM2.5 and all PM2.5 attainment plan precursors that are necessary for such 

expeditious attainment. Thus, in order for a PM2.5 plan to demonstrate that it provides for 

RACM/RACT, it must also demonstrate that it provides for expeditious attainment. 72 FR 20586 

at 20612-20623.

As discussed in Sections II.E and G. of this TSD, we are granting California‘s request to 

extend the attainment date for the South Coast nonattainment area until April 5, 2015 and

approving the attainment demonstration in the South Coast 2007 AQMP as providing for 

expeditious attainment of the 1997 PM2.5 standards in the South Coast nonattainment area by 

that date.

Therefore, EPA finds that the South Coast 2007 PM2.5 Plan, together with the revised 

2007 State Strategy, provides for the implementation of all RACM/RACT necessary for 

expeditious attainment of the 1997 PM2.5 standards in the South Coast nonattainment area as 

required by CAA section 172(c)(1) and 40 CFR § 51.1010 and to approve the South Coast PM2.5

SIP‘s RACM/RACT demonstration pursuant to these sections.

We received a number of comments on our proposed approval of the RACM/RACT

demonstration. We have reviewed these comments and provided responses to them. See section 

III of this TSD. No issues raised in these comments changed our finding that the RACM/RACT 

demonstration in the South Coast 2007 AQMP and revised 2007 State Strategy are consistent 

with the applicable requirements of the CAA and EPA guidance.

Petitions for reconsideration on provisions of the PM2.5 Implementation Rule related to RACT:

As discussed in section I.A.2.b., EPA received a petition for reconsideration of several 

provisions in the PM2.5 implementation rule including three provisions related to RACT. We 

describe each below and whether the provision affects our action on the RACM/RACT 
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demonstration in the South Coast 2007 AQMP.

1. The presumption that compliance with the Clean Air Interstate Rule (CAIR) satisfies the NOx

and SO2 RACT requirements for electric generating units (EGUs). 72 FR 20586, at 20623-28.

The South Coast nonattainment area was not subject to the CAIR, which was intended to 

control the interstate transport of pollutants in the eastern United States. See 70 FR 

26162 (May 12, 2005).

2. The allowance for states to defer establishing emission limits for condensable PM (CPM) 

until January 1, 2011. 72 FR 20586, at 20652 (codified at 40 CFR § 51.1002(c)).

EPA will evaluate any rule adopted or revised after January 1, 2011 to assure that it 

appropriately addresses CPM.

3. The revisions to the criteria for analyzing the economic feasibility of RACT from a 

presumption that a given source must bear a cost similar to other sources and to a consideration 

of whether the cost of a measure is reasonable for the regulated entity to bear, in light of benefits. 

72 FR 20586 at 20619-20620.

While the South Coast 2007 AQMP includes some discussion of economic feasibility that 

seem to reflect the revised criteria in the PM2.5 implementation rule (see Appendix VI p. VI-5),

we can find no example of where those criteria actually resulted in the rejection of a potential 

RACT measure. 
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E. Attainment Date Extension

1. Requirements for Attainment Date Extensions

CAA section 172(a)(2)(A) states that an area‘s attainment date ―shall be the date by 

which attainment can be achieved as expeditiously as practicable, but no later than 5 years from 

the date such area was designated nonattainment..., except that the Administrator may extend the 

attainment date to the extent the Administrator determines appropriate, for a period no greater 

than 10 years from the date of designation as nonattainment considering the severity of 

nonattainment and the availability and feasibility of pollution control measures.‖ Because the 

effective date of the initial PM2.5 designations, including the designation for the South Coast 

nonattainment area, is April 5, 2005, the initial attainment date for PM2.5 areas is as expeditiously 

as practicable but no later than April 5, 2010. For areas that EPA grants the full 5-year 

attainment date extension under section 172(a), the attainment date would be no later than April 

5, 2015. 

Section 51.1004 of the PM2.5 implementation rule addresses the attainment date 

requirement. Section 51.1004(b) requires a state to submit an attainment demonstration justifying 

its proposed attainment date and provides that EPA will approve an attainment date at the same 

time we approve the attainment demonstration. Thus, the selection of an attainment date is 

dependent upon an attainment demonstration showing expeditious attainment.

A state that requests an extension of the attainment date under CAA section 172(a)(2)(A) 

must provide sufficient information to show that attainment by the initial attainment date of April 

5, 2010 is impracticable due the severity of the nonattainment problem in the area and the lack of 

available and feasible control measures to provide for faster attainment. 40 CFR § 51.1004(b) 

The state must also demonstrate that all RACM/RACT for the area are being implemented to 

bring about attainment of the standard by the most expeditious alternative date practicable for the 

area. 72 FR 20586, at 20601. The state‘s plan will need to project the emissions reductions 

expected due to federal and state regulations and local measures such as RACT and RACM, and 

then conduct modeling to project the level of air quality improvement in accordance with EPA‘s 

modeling guidance. EPA will not grant an extension of the attainment date for an area beyond 

the initial 5 years allowed by section 172(a)(2)(A) if the state has not considered the 

implementation of all RACM and RACT local control measures for the area. 72 FR 20586, at 

20601.

2. Proposed Attainment Date in the South Coast 2007 AQMP

The attainment demonstration and the District‘s proposed attainment date are found in 

Chapter 5 of the plan and discussed in more detail in Appendix V. A discussion of the attainment 

date can be found on page V-2-48 of Appendix V. 

The Appendix states: 

A simulation of 2010 annual average PM2.5 was conducted to substantiate the 

severity of the PM2.5 problem in the Basin. The simulation used the projected 
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emissions for 2009 which included all existing and adopted control measures that 

will be implemented prior to 2010. The resulting 2010 future-year design value 

(17.9 μg/m3) failed to meet the federal standard.

Based on this analysis for the annual standard, the District and CARB requested an 

attainment date extension to April 5, 2015 for both the annual and 24-hour PM2.5 standards. See 

SCAQMD Governing Board Resolution adopting the final South Coast 2007 AQMP, June 1, 

2007, p. 4 and 5, and CARB Resolution 07-41, page 8, September 27, 2007. In its 2011 Progress 

Report, CARB continues to project April 5, 2015 as the most expeditious attainment date for the 

South Coast nonattainment area. See 2011 Progress Report, p. 1.

The South Coast 2007 AQMP does not specifically address the most expeditious date for 

attaining the 24-hour PM.2.5 standard, although it does state that all monitoring sites in the 

nonattainment area will meet the 65 ug/m3PM2.5 standard by 2015. South Coast 2007 AQMP, 

Appendix V, page V-2-48.

3. Proposed Actions on the Attainment Date Extension

In our November 2010 proposal, EPA proposed to not grant the State‘s request to extend 

the attainment date for the 1997 PM2.5 standards in the South Coast to April 5, 2015. This 

proposal was based primarily on our proposed disapproval of the RACM/RACT demonstration. 

See 75 FR 71294, at 71306. As stated in the preamble to the PM2.5 implementation rule, (72 FR 

20586, at 20601), EPA cannot grant an extension of the attainment date beyond the initial five 

years provided by section 172(a)(2)(A) if the state has not adequately considered and evaluated 

the implementation of RACM and RACT in the area. By definition, RACM/RACT are those 

controls that are necessary to demonstrate attainment as expeditiously as practicable and to meet 

any RFP requirements. 40 § CFR 51.1010(a). 

We noted in our proposed disapproval that is appeared that the State, District, and local 

jurisdictions had identified and otherwise provided for the implementation of a comprehensive 

set of measures that are among the most stringent in the nation and should the District and State 

correct the deficiencies in the attainment demonstration, we would likely be able to approve the 

SIP‘s RACM/RACT demonstration.

In our July 14, 2011 amended proposal, we proposed to grant the State‘s request to 

extend the attainment date for the 1997 PM2.5 standards in the South Coast to April 5, 2015. This 

proposed approval was based on our proposed approval of the RACM/RACT demonstration and 

the attainment demonstration. See 76 FR 41562, at 41575.

4. Evaluation and Conclusions

The PM2.5 problem in the South Coast nonattainment area is complex, caused by both 

direct and secondary PM2.5 and compounded by the area‘s topographical and meteorological 

conditions that are particularly conducive to the formation and concentration of PM2.5. See 

2007AQMP, Chapter 1.
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As discussed in section II.F. below, the District's and State‘s strategy for attaining the 

PM2.5 standard in the South Coast nonattainment area relies on significant reductions of direct

PM2.5 as well as the PM2.5 precursor pollutants NOx ,SOx and VOC. The State and District have 

already adopted and are currently implementing a comprehensive set of PM2.5, NOx, VOC and 

SOx control measures. We find that these rules and programs provide for the implementation of 

RACM/RACT as required by CAA section 172(c)(1). See section II.D. above.

Reductions in direct PM2.5 emissions are achieved primarily from control measures on 

open burning, residential wood combustion, and in-use trucks and buses. These types of control 

measures present special implementation challenges (e.g., the large number of individuals 

subject to regulation and the difficulty of applying conventional technological control solutions).

Reductions in NOx emissions come largely from District rules for fuel combustion sources and 

from the State‘s mobile source rules. Reductions in SOx emissions come primarily from controls 

on combustion sources and ocean going vessels.

Because of the necessity of obtaining additional emissions reductions from the more 

challenging-to-control source categories and the need to conduct significant public outreach if 

applicable control approaches are to be effective, EPA agrees with the District and CARB that 

the South Coast 2007 AQMP reflects expeditious implementation of these controls during the 

2007-2014 time frame. We also agree that the implementation schedule for the District‘s 

enhanced stationary source controls is expeditious, taking into account the time necessary for 

purchase and installation of the required control technologies. Finally, we believe that it is not 

feasible at this time to accelerate the emissions reduction schedule for the State and Federal 

mobile source which must rely on fleet turnover over the years to ultimately deliver the 

anticipated emissions reductions beyond what is already anticipated from the State‘s in-use 

mobile source control and incentive programs.

Given the complexity of the PM2.5 air quality in the South Coast and adoption and 

expeditious implementation of all reasonably available measures to reduce direct PM2.5 and 

PM2.5 precursors, we believe that the South Coast 2007 AQMP provides for attainment of the 

1997 PM2.5 standards as expeditiously as practicable. EPA, therefore, is granting California‘s 

request for an attainment date extension to April 5, 2015 for the South Coast PM2.5

nonattainment area pursuant to CAA section 172(b)(2).

We received several comments on our proposed approval of the attainment date 

extension. We have reviewed these comments and provided responses to them. See section III of 

this TSD. No issues raised in these comments changed our finding that the attainment date 

extension in the South Coast 2007 AQMP and revised 2007 State Strategy is consistent with the 

applicable requirements of the CAA and EPA guidance.
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F. Adopted Control Strategy and Enforceable Commitments

1. Requirements for Control Strategies and Enforceable Commitments

CAA section 172(c)(6) requires nonattainment plans to ―include enforceable emission 

limitations, and such other control measures, means or techniques (including economic 

incentives such as fees, marketable permits, and auctions of emission rights), as well as 

schedules and timetables for compliance, as may be necessary or appropriate to provide for 

attainment of such standard in such area by the applicable attainment date....‖ CAA 

section110(a)(2)(A), which applies to all SIPs, contains virtually identical language. 

The PM2.5 implementation rule requires all control measures needed for attainment to be 

implemented as expeditiously as practicable but no later than the beginning of the year prior to 

the attainment date. 40 CFR § 51.1007(b).

In most instances, a nonattainment plan should include the adopted measures it relies on 

to demonstrate attainment and RFP and/or meet any other CAA requirements or should identify 

the adopted measures it relies on that are already SIP approved, federally promulgated, or 

otherwise SIP creditable. EPA, however, recognizes that circumstances exist that warrant the

initial use of enforceable state commitments in place of these adopted measures. We believe that 

the CAA allows approval of such enforceable commitments as elements of a CAA control 

strategy requirement where they are limited in scope.

The language in CAA sections 110(a)(2)(A) and 172(c)(6) cited above is quite broad, 

allowing a SIP to contain any ―means or techniques‖ that 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 applicable attainment date. Furthermore, the express allowance 

for ―schedules and timetables‖ demonstrates that Congress understood that all required controls 

might not have to be in place before a SIP could be fully approved.

Commitments approved by EPA under CAA section 110(k)(3) are enforceable by EPA 

and citizens under, respectively, CAA sections 113 and 304. In the past, EPA has approved 

enforceable commitments and courts have enforced actions against states that failed to comply 

with them.72 Further, if a state fails to meet its commitments, EPA could 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.

Once EPA determines that circumstances warrant the use of an enforceable commitment, 

EPA considers three factors in determining whether to approve the enforceable commitment: (a) 

does the commitment address a limited portion of the statutorily-required program; (b) is the 

 

72 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). 
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state capable of fulfilling its commitment; and (c) is the commitment for a reasonable and 

appropriate period of time.73

2. Control Strategy in the South Coast 2007 AQMP and Revised 2007 State Strategy

For the purposes of evaluating the South Coast 2007 AQMP and 2007 State Strategy, we 

have divided the measures relied on in the attainment and RFP demonstrations and to meet the 

contingency measures requirement 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 October 2006 (i.e., prior to the development of the South Coast 2007 

AQMP and 2007 State Strategy) that continue to generate emissions reductions through to the 

attainment year of 2014 and beyond.74 2007 State Strategy, Appendix A, p. 1., and South Coast 

2007 AQMP, Appendix III, p. III-2-3. Reductions from these measures are incorporated into the 

baseline inventory and, for the most part, not individually quantified. These measures provide 

the majority of emissions reductions needed to attain the PM2.5 standards in the South Coast 

nonattainment area. See Table G-1 in this TSD.

Control strategy measures are the new rules, rule revisions, commitments and other 

adjustments to the inventory that provide the additional increment of emission reductions needed 

beyond the baseline measures to demonstrate RFP and attainment, meet RACM/RACT, and/or 

provide for contingency measures. 

We evaluate the control strategy measures in this section. Baseline measures are listed in 

Appendices A and B to this TSD.

a. District Control Strategy Measures and Commitments

For the South Coast 2007 AQMP, the District identified and committed to updating and 

adopting 9 control measures and newly adopting and implementing 28 new control measures to 

reduce emissions of direct PM2.5, NOx, SOx, and/or VOC. In Table F- 1 below, we list the 

anticipated timing of the expected emissions reductions from these measures; however, we note 

that the District‘s commitment is only to aggregate emissions reductions. See South Coast 2007 

AQMP, p. 4-2 and 4-73 and SCAQMD Governing Board Resolution, p. 10. 

In Table F-2, we give the current SIP submittal and approval status of the measures in the 

South Coast 2007 AQMP. In Tables F-3, we show the emissions reductions, as given in the 

South Coast 2007 AQMP and in individual rule submittals, for the measures that have been 

approved by EPA and for the measures that have been approved by or submitted to EPA, 

respectively. The reductions listed in Table F-3 are the ones anticipated to be achievable from 

 

73

 The U.S. Court of Appeals for the Fifth Circuit upheld 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 

Houston-Galveston ozone SIP. BCCA Appeal Group et al. v. EPA et al., 355 F.3d 817 (5th Cir. 2003).

74 These measures are typically rules that have compliance dates that occur after the adoption date of a plan and 

mobile source measures that generate reductions through fleet turnover.
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each rule at the time the South Coast 2007 AQMP was adopted. Actual reductions from each 

rule once adopted may be greater or less than the anticipated reductions. Finally, in Table F-4 we 

show the emissions reductions as updated in the South Coast PM2.5 Progress Report for the 

measures that have been approved or proposed for approval by EPA, and in Table F-5 we 

provide the overall control strategy for the South Coast 2007 AQMP.
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Table F-1

South Coast Air Quality Management District 

Estimated Emissions Reductions for South Coast 2007 AQMP Specific Rule Commitments

(tons per average annual day)

NOx VOC PM2.5 SOx

Based on 

Adoption Date

Based on 

Implementation 

Date

Based on 

Adoption 

Date

Based on 

Implementation 

Date

Based on 

Adoption 

Date

Based on 

Implementa

tion Date

Based on 

Adoption 

Date

Based on 

Implementati

on Date

2007 0.4 0.4 0.8 0.8 1.0 -- -- --

2008 5.6 -- 3.1 -- 0.4 1.0 3.0 --

2009 0.8 -- 4.5 -- 0.4 -- -- --

2010 -- 0.5 2.0 3.1 1.2 0.4 -- --

2011 -- -- -- 0.8 -- -- -- --

2012 -- -- -- 3.7 -- -- -- --

2013 -- -- -- -- -- -- -- --

2014 -- 3.5 -- 1.1 -- 3.0

2023 -- 2.4 -- 2.0 ---- 0.4 -- --

Commitment to Total 

Reductions 6.8 6.8 10.4 10.4 2.9 2.9 3.0 3.0

Source: South Coast 2007 AQMP, Table 4-10
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Table F-2

Approval and Submittal Status of District Rules in the South Coast 2007 AQMP

Rule 445 - Woodburning fireplaces and 

wood stoves SIP- approved 74 FR 27716, 6/11/09

Rule 461 – Gasoline transfer and 

dispensing SIP-approved 71 FR 18216, 4/11/06

Rule 1110.2 – Liquid and gaseous fuels 

– stationary ICEs SIP-approved 74 FR 18995, 4/27/09

Rule 1111 - Further NOx reductions 

from space heaters SIP-approved 75 FR 46845, 08/04/10

Rule 1127 - Livestock Waste1 Submitted to EPA on 

10/05/06

Rule 1138 – Restaurant Operations SIP-approved 66 FR 36170, 7/11/01

Rule 1143 - Consumer Paint Thinners 

and Multi-Purpose Solvents1

Proposed for SIP 

approval 76 FR 41744, 07/15/11 

Rule 1144 - Vanishing oils and rust 

inhibitors1

Proposed for SIP 

approval 76 FR 41744, 07/15/11

Rule 1145 – Plastic, Rubber, Leather 

and Glass Coatings SIP-approved 75 FR 40726, 07/14/10

Rule 1146 – NOx from industrial, 

institutional, commercial boilers, steam 

gens, and process heaters1

Proposed limited 

approval/limited 

disapproval

Proposed limited 

approval/limited disapproval 76 

FR 40303, 7/8/11

Rule 1146.1 - NOx from small 

industrial, institutional, commercial 

boilers, steam gens, and process 

heaters1

Proposed limited 

approval/limited 

disapproval

Proposed limited 

approval/limited disapproval 76 

FR 40303, 7/8/11

Rule 1147 – NOx reductions from 

miscellaneous sources SIP-approved 75 FR 46845, 08/04/10

Rule 1149- Storage Tank and Pipeline 

Cleaning and Degassing SIP- approved 74 FR 67821, 12/21/09

Rule 2002- Further SOx reductions 

from RECLAIM SIP-approved 76 FR 50128, 8/12/11

Rule 2301 – Indirect Source Review 2012

Refinery Pilot Program

Not yet adopted

N/A
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Table F-2

Approval and Submittal Status of District Rules in the South Coast 2007 AQMP

SOON program1 Submitted to EPA on 

July 18, 2008

AB923 light duty vehicle high emitter 

program

No rules associated 

with these measures N/A

AB923 medium duty vehicle high 

emitter program

No rules associated 

with these measures N/A

1These rules have been adopted by the District and submitted to EPA, but EPA has not yet 

completed a final action on them. The emissions reductions from these measures will not be 

credited until EPA takes final approval action.
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Table F-3. Status of District Short and Intermediate Term Control Measures Credited in South Coast 2007 AQMP 

Attainment Demonstration

Control 

measure

Rule 

No.

Title Emissions Reduction Commitment in 

South Coast 2007 AQMP

Emissions Reductions 

Achieveda

BCM-03 445 Woodburning fireplaces and 

woodstoves

1.0 tpd PM2.5

0.44 tpd VOC, 1.0 tpd 

PM2.5, 0.06 tpd NOx, 0.01 

tpd SOx

BCM-05 1138 Underfired charbroilers 1.1 tpd PM2.5 n/a

CTS-01 1144

Metalworking fluids and 

direct-contact lubricants 1.9 tpd VOC 3.9 tpd VOCb

CTS-04 1143

Consumer Paint Thinners and 

Multi-Purpose Solvents n/a 9.7 tpd VOCb

CMB-01 1147

NOx reductions from 

miscellaneous sources 3.5 tpd NOx 3.5 tpd NOx

CMB-02 2002

Further SOx reductions from 

RECLAIM 2.9 tpd SOx 4.0 tpd SOx

FUG - 02 461

Gasoline transfer and 

dispensing 3.7 tpd VOC 0

FUG - 04 1149

Storage Tank and Pipeline 

Cleaning and Degassing none 0.04 tpd VOC

CMB-03 1111 Further NOx reductions from 

space heaters 0.8 tpd NOx 0.1 tpd NOx

MCS-01 1110.2 Liquid and gaseous fuels –

stationary ICEs

1.6 tpd NOx

0.6 tpd NOx

0.3 tpd VOC

1146

NOx from industrial, 

institutional, & commercial 
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boilers, steam generators, and 

process heaters

0.4 tpd PM2.5

2.0 tpd VOC 

1146.1

NOx from small ind, inst, & 

comm‘l boilers, steam gens, 

and proc. htrs

MCS-05 1127 Livestock waste 0.8 tpd VOC

FLX-02 Refinery pilot program 0.7 tpd VOC, 0.4 tpd PM2.5

SOON 

program

4-8 tpd NOx

MOB-05 2251 AB923 LDV high emitter 

program

0.8 tpd VOC, 0.4 tpd NOx

MOB-06 AB923 MDV high emitter 

program

0.5 tpd VOC, 0.5 tpd NOx

SIP commitment -

PM2.5 2.9 tpd PM2.5 Total achieved PM2.5 reductions 1.0 tpd PM2.5

SIP commitmentNOx 10.8 tpd NOx Total achieved NOx reductions 4.2 tpd NOx

SIP commitment -

VOC 10.4 tpd VOC Total achieved VOC reductions 0.8 tpd VOCb

SIP commitment -

SOx 2.9 tpd SOx Total achieved SOx reductions 4.01 tpd SOx

a

From SCAQMD‘s 2011 ―Revisions to PM2.5 and Ozone State Implementation Plan for South Coast Air Basin and Coachella Valley‖ and District rule 

evaluation forms. Some emissions reduction commitments were revised from the information provided in the South Coast 2007 AQMP.

b We are not crediting the 3.9 tpd of VOC reductions from SC Rule 1144 and the 9.7 tpd of VOC reductions from SC Rule 1143 at this time. On July 15, 2011, 

we simultaneously published a direct final rule and a proposed rule approving South Coast Rules 1143 (Consumer Paint Thinners and Multi-Purpose Solvents) 

and 1144 (Metalworking Fluids and Direct-Contact Lubricants). See 76 FR 41744. We received comments on our action on Rules 1143 and 1144, and thus 

withdrew the direct final rule (see 76 FR 54384, September 1, 2011). We are responding to comments received on our proposal but have not yet finalized that 

action, and therefore are adding those reductions to the State‘s remaining enforceable commitment for VOC. See also Table G-4 for the impact on the State‘s 

remaining enforceable commitments.
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Table F-4

South Coast Air Quality Management District 

Estimated Emissions Reductions for South Coast 2007 AQMP Specific Rule Commitments, 

as Updated by 2011 Progress Report (tons per average annual day)

Pollutant

SIP Commitment by 2014

Commitment Achieved Balance

NOx 10.80 4.20 -6.6

VOC 10.40 0.8 -9.6

PM2.5 2.90 1.00 -1.90

SOx 2.90 4.01 +1.11

Source: 2011 State Strategy Progress Report, Appendix F, Table 1. The ―Achieved‖ column in this table reflects District rules 

submitted to EPA and fully approved for SIP credit. Note that a number of rules adopted by the District and submitted to EPA are 

pending final EPA approval. See Tables F-2 and F-3. 
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

Facility Modernization

MCS-01 Facility Modernization (NOx, VOC, PM2.5) SCAQMD 2008+ 2011+

Energy Efficiency/Conservation

MCS-02 Urban Heat Island [All Pollutants] SCAQMD On-going On-going

MCS-03 Energy Efficiency and Conservation [all 

Pollutants]

SCAQMD 2008-2010 Beginning 2010

Good Management Practices

FUG-01 Improved Leak Detection and Repair [VOC] SCAQMD 2008-2009 2009-2010

FUG-02 Emission Reductions from Gasoline Transfer 

and Dispensing Facilities [VOC]

SCAQMD (a)

FUG-04 Emission Reductions from Pipeline and 

Storage Tank Degassing [VOC]

SCAQMD 2008 2008

BCM-01

PM Control Devices (Baghouses, Wet 

Scrubbers, Electrostatic Precipitators, Other 

Devices)[PM]

SCAQMD

2008-2009 2010-2012

MCS-04 Emissions Reductions from Green Waste 

Composting [VOC, PM]

SCAQMD Phase 1: 2008-09

Phase 2: 2010 2012

MCS-06 Improved Start-up, Shut-Down, and 

Turnaround Procedures [All Pollutants]

SCAQMD 2010 2012

Market Incentives/Compliance Flexibility

CTS-02 Clean Coating Certification Program [VOC] SCAQMD 2009-2010 2010

CMB-02 Further SOx Reductions from RECLAIM 

(BARCT) [SOx]

SCAQMD 2010 2013-2019

FLX-01 Economic Incentive Programs [All 

Pollutants]

SCAQMD On-going On-going

FLX-02 Petroleum Refinery Pilot Program [VOC and 

PM2.5]

SCAQMD 2008
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

Area Sources

FUG-03 Emissions Reductions from Cutback Asphalts 

[VOC]

SCAQMD 2008 2010

CTS-01 Emissions Reductions from Lubricants 

[VOC]

SCAQMD 2009 2011

CTS-03

Consumer Products Certification and 

Emissions Reductions from Use of Consumer 

Products at Institutional and Commercial 

Facilities [VOC]

SCAQMD

2007-2010 2010-2020

CTS-04

Emission Reductions from the Reduction of 

VOC Content of Consumer Products not 

Regulated by the State Board [VOC]

SCAQMD

2008-2010 2010-2020

CMB-01 NOx Reductions from non-RECLAIM 

Ovens, Dryers, and Furnaces [NOx]

SCAQMD 2008 2010

CMB-03 Further NOx Reductions from Space Heaters 

[NOx]

SCAQMD 2009 2012-2043

CMB-04 Natural Gas Fuel Specifications [All 

Pollutants]

SCAQMD

2008 2009

BCM-02 PM Emission Hot Spots – Localized Control 

Program [PM2.5]

SCAQMD On-going On-going

BCM-03 Emission Reductions from Wood Burning 

Fireplaces and Wood Stoves [PM2.5]

SCAQMD 2008 2008-2014

BCM-04 Additional PM Emission Reductions from 

Rule 444 - Open Burning [PM2.5]

SCAQMD 2007 2008-2010

BCM-05 PM Emission Reductions from Underfired 

Charbroilers [PM2.5]

SCAQMD 2011-2012 2014

MCS-05 Emission Reductions from Livestock Waste 

[VOC]

SCAQMD 2009 2011

MCS-07 Application of all Feasible Measures [All 

Pollutants]

SCAQMD 2008 2008

MCS-08 Clean Air Act Emission Fees for Major SCAQMD 2009-2010 2011
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

Stationary Sources [VOC, Nox]

Emission Growth Management

EGM-01 Emission Reductions from New or 

Redevelopment Projects [NOx, VOC, PM2.5] SCAQMD 2012 Beginning 2014

EGM-02 Emission Budget and Mitigation for General 

Conformity Projects [All Pollutants] SCAQMD Beginning 2007 Beginning 2007

EGM-03 Emissions Mitigation and Federally Permitted 

Projects [All Pollutants] SCAQMD Beginning 2007 Beginning 2007

District’s Mobile Source Program

MOB-01 Mitigation Fee Program for all Federal 

Sources [All Pollutants]

SCAQMD 2007-2010 2010-2020

MOB-02 Expanded Exchange Program [All Pollutants] SCAQMD

Beginning 2007

2010-2020

MOB-03

Backstop Measure for Indirect Sources of 

Emissions at Ports and Port-Related Facilities 

[All Pollutants]

SCAQMD

2007-2010 2010-2020

MOB-04 Emission Reductions from the Carl Moyer 

Program [NOx, PM2.5]

SCAQMD On-going On-going

MOB-05 AB923 Light Duty Vehicle High Emitter 

Identification Program [NOx, VOC]

SCAQMD On-going On-going

MOB-06 AB923 Medium Duty Vehicle High Emitter 

Identification Program [NOx, VOC]

SCAQMD

Ongoing Ongoing

MOB-07 Concurrent Reductions From Global 

Warming Strategies [All Pollutants]

SCAQMD On-going On-going

SOON Surplus Off-Road Opt-In for NOx SCAQMD 2008 2008-2014

Mobile Source and Consumer Product Control Measures Developed by CARB*

ARB-ONRD01Smog Check Enhancements [VOC, NOx, 

PM] BAR 2007-2008 By 2010

ARB-ONRD- Expanded Vehicle Retirement [VOC, NOx, CARB/BAR 2008-2014
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

02 PM] 2008-2014

ARB-ONRD03Modifications to Reformulated Gasoline 

Program [VOC] CARB 2007 Beginning 2010

ARB-ONRD04Cleaner In-Use Heavy Duty Trucks [VOC 

,NOx, PM] CARB 2008 2010-2015

ARB-ONRD05 Port Truck Modernization [NOx, 

PM] CARB/ SCAQMD 2007-2008 2008-2020

ARB-OFRD01Marine Vessels – Fuel, Auxiliary 

& Main Engines [VOC, NOx] 

U.S. 

EPA/CARB/SCAQ

MD

2007-2009 Beginning 2010

ARB-OFRD02Accelerate Introduction of

Cleaner Line-Haul Locomotives

[VOC, NOx, PM]

CARB/U.S. EPA 2007-2008 Beginning 2012

ARB-OFRD03Clean Up Existing Harbor Craft

[VOC, NOx, PM] CARB 2007 2009-2018

ARB-0FRD04Cleaner In-Use Off-Road

Equipment [VOC, NOx, PM] CARB 2007 Phase in starting 2008

ARB-OFRD05New Emission Standards for

Recreational Boats [VOC, NOx] CARB 2009-2010 2012-2023

ARB-OFRD06Expanded Off-Road Recreational

Vehicle Emission Standards

[VOC]

CARB By 2010 2012-2023

ARB-CONS01 Consumer Products [VOC] CARB 2007-2012 2010-2014

Recommended Mobile Source and Clean Fuel Control Measures*

SCONRD-01 Accelerated Penetration of

Advanced Technology Partial CARB 2007-2008
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

Zero and Zero Emission Vehicles

[VOC, NOx, CO]

2010-2023

SCONRD-02 Deployment of On-Board

Diagnostics (Phase III) in Light and

Medium Duty Vehicles

[VOC, NOx, CO, PM]

CARB/BAR 2008 2012-2023

SCONRD-03

Further Emission Reductions 

From On Road Heavy-Duty 

Vehicles [NOx, PM] CARB/SCAQMD 2008 2010-2014

SCONRD-04 Further Emission Reductions 

from Heavy-Duty Trucks 

Providing Freight Drayage 

Services [NOx, PM] 

CARB/

Marine Ports/

SCAQMD 2007-2008 2008-2023

SCOFFRD-01

Construction/Industrial 

Equipment Fleet Modernization 

[VOC, NOx] 

CARB 2007 2009-2023

SCOFFRD-02

Further Emission Reductions 

from Cargo Handling Equipment 

[NOx, PM] CARB/Marine Ports 2007-2008 2010-2014

SCOFFRD-03

Further Emission Reductions 

from Locomotives [NOx, PM] U.S.EPA 2007-2008 2012-2014

SCOFFRD-04

Emission Reductions from 

Airport Ground Support 

Equipment [NOx, VOC, PM] CARB 2007-2008 2010-2014

SCOFFRD-05

Emission Reductions from 

Transport Refrigeration Units 

[NOx] 

CARB 2009

2010-2023
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

SCOFFRD-06

Accelerated Turnover and 

Catalyst Based Standards for 

Pleasure Crafts [VOC, NOx, PM] 

CARB 2007-2008 2010-2023

SCFUEL-01 Further Emission Reduction from 

Gasoline Fuels [NOx, SOx] 

CARB 2007 2010-2012

SCFUEL-02 Greater Use of Diesel Fuel 

Alternatives [NOx, SOx, PM] CARB/SCAQMD 2008 2015

Transportation Control Measures

TCM-A HOV Improvements SCAG, CTCs, 

Local Gov‘t 2007 2007-2023

TCM-B Transit & Systems Management SCAG, CTCs, 

Local Gov‘t 2007 2007-2023

TCM-C Information Based Measures SCAG, CTCs, 

Local Gov‘t 2007 2007-2023

Long-Term Mobile Source and Consumer Product Control Measures 

SCLTM-01A Further Emission Reductions 

from On-Road Mobile Sources 

[NOx] 

CARB 2009-2012 

2015-2023

SCLTM-01B Further Emission Reductions 

from On-Road Heavy-Duty CARB/BAR 2009-2012 2015-2023
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Table F-5

South Coast Air Quality Management District 2007 AQMP Control Measures, Implementing Agency, Adoption 

Date, and Implementation Period (updated April 2011)

Control Measure Implementing 

Agency 

Adoption Date Implementation period

Vehicles [NOx] 

SCLTM-02 Further Emission Reductions 

from Off-Road Mobile Sources 

[NOx] 

CARB/ U.S. EPA 2009-2012 2015-2023

SCLTM-03 Further Reductions from 

Consumer Products [VOC] CARB 2009-2012

2015-2023

From South Coast 2007 AQMP, Table 7-3, pages 7-5 to 7-9, as revised by the 2011 Progress Report, Appendix F.

(a) SCAQMD lacks the legal authority to adopt the control that was listed in the original 2007 AQMP.

* The 2007 South Coast AQMP notes that ―The recommended mobile source and clean fuel control measures listed in this table represent a menu of potential 

control strategies which could be implemented by CARB to achieve the additional 63 tons per day of NOx reductions needed for PM2.5 attainment by 2015. 

Annual rulemaking schedule to be developed by CARB within adoption date window but at earliest practicable date to achieve the necessary reductions.‖ When 

CARB adopted the South Coast 2007 AQMP, it did not adopt the measures assigned to CARB by SCAQMD in this table.
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b. CARB Measures and Commitments

The 2007 State Strategy includes a commitment by CARB to propose new defined 

measures. 2007 State Strategy, page 62, and CARB Resolution 07-28, Attachment B, page 8 and

2011 Progress Report, Appendix B.. Table F-6 below lists these defined measures and their 

current adoption and approval status. As can be seen from this table, the State has already 

adopted and EPA has approved or proposed to approve, or is in the process of granting waivers 

under CAA section 209 for most of these measures. These new measures build on the State‘s 

already extensive list of adopted measures, which can be found in the 2007 State Strategy (page 

38) and in Appendix A of this TSD.

In addition to the State‘s commitment to propose specific measures, the 2007 State 

Strategy includes an enforceable commitment for emissions reductions sufficient in combination 

with existing measures and the District‘s commitments to attain the PM2.5 NAAQS in the South 

Coast nonattainment area by the requested attainment date of April 5, 2015. For the South Coast 

PM2.5 nonattainment area, the 2007 State Strategy includes a State commitment to achieve 9 tpd 

of direct PM2.5, 46 tpd of VOC, 20 tpd of SOx and 152 tpd of NOx in the South Coast 

nonattainment area by 2014. See 2007 State Strategy, p. 63 and CARB Resolution 07-28, 

Attachment B, p. 4. The nature of this commitment is described in the State Strategy as follows:

―The total emission reductions from the new measures necessary to attain the federal

standards are an enforceable State commitment in the SIP. While the proposed State

Strategy includes estimates of the emission reductions from each of the individual new

measures, it is important to note that the commitment of the State Strategy is to 

achieve the total emission reductions necessary to attain the federal standards, which 

would be the aggregate of all existing and proposed new measures combined. 

Therefore, if a particular measure does not get its expected emission reductions, the 

State still commits to achieving the total aggregate emission reductions, whether this is 

realized through additional reductions from the new measures or from alternative 

control measures or incentive programs. If actual emission decreases occur in any air 

basin for which emission reduction commitments have been made that are greater than 

the projected emissions reductions from the adopted measures in the State Strategy, 

the actual emission decreases may be counted toward meeting ARB‘s total emission

reduction commitments.‖

CARB Resolution 07-28 (September 27, 2007), Appendix B, p. 3.

The 2011 Progress Report further discusses this commitment: 

―When ARB adopted the 2007 State Strategy as a SIP revision, the State of California

made a legal commitment, required by the Clean Air Act and enforceable in federal

court, to reduce emissions to the levels necessary for attainment. ARB specifically

identified several ways this emission reduction commitment could be achieved:

New measures as described in the SIP

Other alternative measures that ARB had not considered at the time the 

SIP was adopted

Incentive programs that support the replacement or retrofit of aging, 

higher polluting pieces of equipment
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Actual emission decreases‖

2011 Progress Report, p. 4.

As described in section II.A.3 of this TSD, CARB has adjusted baseline emissions 

estimates for source categories subject to its recently-revised in-use rules. Table F-6 reflects the 

revised implementation schedule CARB submitted in its 2011 Progress Report. Table F-7 shows 

original and adjusted baseline emissions inventories for the sources affected by each measures. 

The adjustments to the inventories show the effect of the resent economic recession and, for 

some source categories, changes to inventory methodologies. Table F-8 lists the emissions 

reductions (from the adjusted baseline emissions inventories) that the State now estimates it will 

achieve from its measures as adopted or revised and which are currently creditable towards 

CARB‘s commitment.

Table F-6 

Revised 2007 State Strategy Defined Measures Schedule for Consideration 

and Current Status

State Measures Expected Action 

Year Current Status

Defined Measures in 2007 State Strategy

Smog Check Improvements 2007-2009

Elements approved 75 FR 

38023 (July 1, 2010)75

Expanded Vehicle Retirement (AB 118) 2007

Adopted by CARB, June 

2009; by BAR, September 

2010

Modifications to Reformulated Gasoline 

Program 2007 Approved 75 FR 26653 (May 12, 2010)

Cleaner In-use Heavy Duty Trucks 2007, 2008, 2010 Proposed approval 76 FR 

40562, July 8, 2011

Auxiliary Ship Cold Ironing and Other Clean 

Technologies 2007-2008 Adopted December, 2007 

Cleaner Main Ship Engines and Fuels Fuel: 2008-2011

Engines: 2008

Proposed approval 76 FR 

40562, July 8, 2011

Port Truck Modernization 2007, 2008, 2010 Adopted December 2007 and 

December 2008

Accelerated Introduction of Cleaner 

Locomotives 2008

Prop 1B funds awarded to 

upgrade line-haul locomotive 

engines not already accounted 

for by enforceable agreements 

with the railroads. Those 

cleaner line-hauls will begin 

 

75 California Assembly Bill 2289, passed in 2010, requires the Bureau of Automotive Repair to direct older vehicles 

to high performing auto technicians and test stations for inspection and certification effective 2013. Reductions 

shown for the SmogCheck program in the 2011 Progress Report do not include reductions from AB 2289 

improvements. See CARB Progress Report Supplement, Attachment 5.
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Table F-6 

Revised 2007 State Strategy Defined Measures Schedule for Consideration 

and Current Status

State Measures Expected Action 

Year Current Status

operation by 2012.

Clean Up Existing Harbor Craft 2007, 2010 Adopted November 2007, 

revised June 2010.

Cleaner In-Use Off-Road Engines 2007 Waiver action pending 

New Emissions Standards for Recreational 

Boats 2013

Partially adopted, July, 2008; 

additional action expected 

2013.

Expanded Off-Road Recreational Vehicle 

Emissions Standards 2013

Partially adopted, July, 2008; 

additional action expected 

2013.

Enhanced Vapor Recovery for Above 

Ground Storage Tanks 2008 Adopted June, 2007

Additional Evaporative Emissions Standards By 2010 Partial adoption: September, 

2008 (outboard marine tanks)

Consumer Products Program 2009, 2011

Phase I – Approved, 74 FR

57074 (November 4, 2009).

Phase II – Approved, 76 FR

27613 (May 12, 2011).

proposed approval of 2011 

rule signed September 28, 

2011.

Sources: 2009 State Strategy Status Report, p. 23 (footnotes in original not included) and 2011 Progress Report, 

Table 1, page 9. Additional information from www.ca.arb.gov. Only defined measures with PM2.5 or NOx 

reductions in South Coast are shown here.
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Table F-7

Original and Adjusted Baseline Emissions Inventories

By State Measure

(tons per day, 2014)

State Measure

Directly-Emitted PM2.5 NOx VOC SOx

Original Adjust

ed Change Original Adjusted Change Original Adjusted Change Original Adjusted Change

Smog Check 

Improvements (BAR) 7.8 7.8 0 134

134

0 132.1 132 0

Cleaner In-Use HeavyDuty Trucks & Buses 5.8 6.0 +0.2 136

151

+15.2 10.2 8.7 -1.5 0.3 0.3 0

Cleaner In-Use Off-Road 

Equipment (>25hp) 4.9 1.3 -3.6 96.9

28.0

-68.9 13.4 2.6 -10.8

Ship Auxiliary Engine 

Cold Ironing and Clean 

Technology

0.6 0.5 -0.1 37.2 23.7 -13.5 0.7 0.9 +0.2 1.1 1.1 0

Cleaner Main Ship 

Engines and Fuel – Main 

Engines

2.6 3.9 +1.3 33.4 38.5 +5.1 0.2 1.9 +1.7 20.7 38.7 +18

Accelerated Intro. Of 

Cleaner Line-Haul 

Locomotives

0.7 0.7 0 18.3 18.3 0 2.3 2.3 0

Clean up Existing Harbor 

Craft 0.7 0.6 -0.1 15.7

15.2

-0.5 0.7 1.2 +0.5

Cargo Handling 

Equipment 0.1 0.1 0 5.2

3.2

-2.0 0.6 0.3 -0.3

New Emission Standards 

for Recreational Boats 11.0

11.0

0 37.9 37.9 0
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Table F-7

Original and Adjusted Baseline Emissions Inventories

By State Measure

(tons per day, 2014)

State Measure

Directly-Emitted PM2.5 NOx VOC SOx

Original Adjust

ed Change Original Adjusted Change Original Adjusted Change Original Adjusted Change

Expanded Off-Road Rec. 

Vehicle Emissions 

Standards

6.7 6.7 0

Consumer Products 

Program na Na na na

na

na 102.6 102.6 0 na na na

All Other State, Local and 

Federal Measures 74 165

166

221

Totals: 102 95 7 654 589 65 528 518 10 22.2 40.1 18

Source: 2011 Progress Report, Appendix E, p. 4.

1

Includes emissions from recreational boats.

2

Includes emissions from all sources categories except for those subject to the Truck & Bus and Off-Road Equipment Rules
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a

This rule was submitted by CARB on May 2, 2011, and we expect to be able to act on it and 

thus credit it in our final action.

Table F-8

Creditable Emissions Reductions from Defined Measures in the 2007 

State Strategy for the South Coast

(tons per day 2014)

State Measure

DirectlyEmitted 

PM2.5

NOx VOC SOx

Smog Check Improvements (BAR) 0.3 2.6 8.6 0

Cleaner In-Use Heavy-Duty Trucks 2.6 18.6 3.3 Na

Cleaner In-Use Off-Road Equipment (> 25 

hp) 0 0.5 0.1 Na

Ship Auxiliary Engine Cold Ironing & Clean 

Tech. 0.1 8.1 0.2 0.3

Cleaner Main Ship Engines and Fuel - Main 

Engines 3.5 17.6 0.5 37

Accelerated Intro. Of Cleaner Line-Haul 

Locomotives 0 0 0 na

Clean Up Existing Harbor Craft

0.2 4.1 0.1 na

Cargo Handling Equipment

0 0 0 na

New Emission Standards for Recreational 

Boats Na 0 0 na

Expanded Off-Road Rec. Vehicle Emissions 

Standards Na 0 na

Consumer Products 0 0 5.9 0

All other local, state, and federal measures 1 7 0.8 4

Totals: 7.7 58.5 19.5 41.3

Source: 2011 Progress Report, Appendix E, pp. 2 and 3 Only defined measures with directlyemitted PM2.5, VOC, SOx and/or NOx, reductions in the South Coast are shown here.
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3. Proposed Actions on the Control Strategy and Enforceable Commitments

In our November 2010 proposal and our July 2011 amended proposal, we found that 

circumstances warranted the consideration of enforceable commitments as part of the South 

Coast 2007 AQMP‘s attainment demonstration for the PM2.5 standards. We also found that both 

the State and the District had demonstrated the capability to meet their commitments. However, 

in our November 2010 proposal, we did not find that the commitments constituted a limited 

portion of the required emissions reductions needed for attainment. The State‘s and District‘s 

unfulfilled commitments at the time of our 2010 proposal represented 89 percent of the PM2.5

reductions, 30 percent of the NOx reductions, 18 percent of the VOC reductions and 53 percent 

of the SOx emissions reductions estimated to be needed for attainment. We also found that the 

commitments, which were for the most part to achieve the reductions by 2014, were not for an 

appropriate timeframe given that we were proposing to not grant the State‘s request to extend the 

applicable attainment date from 2010 to 2015. See 75 FR 71294, at 71309-71310. Because we 

could not make two of the necessary findings, we were unable to propose to approve the 

attainment demonstration that relied in part on these commitments. We did, however, propose to 

approve the District‘s and CARB‘s commitments to adopt and implement specific control 

measures on the schedule identified in their plans and to achieve the aggregate emissions 

reductions identified in their plans because they would strengthen the SIP.

In our July 14, 2011 amended proposal, we found that the commitments constituted a 

limited portion of the required emissions reductions needed for attainment. The State‘s and 

District‘s unfulfilled commitments at the time of our 2011 amended proposal represented 8

percent of the direct PM2.5 reductions, 11 percent of the NOx reductions, 3 percent of the VOC 

reductions and 0 percent of the SOx emissions reductions estimated to be needed for attainment.

We also found that the commitments, which were for the most part to achieve the reductions by 

2014, were for an appropriate timeframe given that we were proposing to grant the State‘s 

request to extend the applicable attainment date from 2010 to 2015. See 76 FR 41562, at 41577.

4. EPA‘s Evaluation and Conclusion

a. Baseline and Control Strategy Measures

As shown in Table F-9, the majority of the emission reductions needed to demonstrate 

attainment come from baseline measures. These reductions come from a combination of District 

and State measures as well as adjustments to the baseline that reflect revisions to the economic 

forecasts that underlie the 2007 AQMP‘s estimate of future emissions levels.

76

In the past two decades, the District has adopted or revised about 80 prohibitory rules that 

limit emissions of NOx, VOC, particulate matter and/or SOx including most of the rule 

 

76

 Reductions in the baseline also come from federal measures. These federal measures include 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 (May 16, 1998) and 73 FR 37045 

(June 30, 2008)). States are allowed to rely on reductions from federal measures in attainment and RFP 

demonstrations and for other SIP purposes.
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adoptions/revisions it committed to as part of the South Coast 2007 AQMP. See Appendix B 

and Tables F-2 and F-3. These rules include controls for boilers, fugitive dust sources, internal 

combustion engines, wood burning, and open burning. The great majority of these rules and rule 

revisions are currently SIP approved and as such their emissions reductions are fully creditable in 

attainment and RFP demonstrations and for meeting other CAA requirements, such as 

contingency measures.

Table F-9

Summary of Reductions Needed for South Coast‘s PM2.5 Attainment 

Demonstration, Updated April 2011

(tons per average annual day in 2014)

NOx VOC PM2.5 SOx

A 2002 baseline emissions level 1093 844 99 53

B 2014 attainment target level 460 474 86 20

C

Total reductions needed from 2002 baseline 

levels to attain in 2014 (A – B) 633 370 13 33

D 2014 baseline emissions level 654 528 102 43

E. Adjustment to 2014 baseline emissions level 65 10 7 -18

F Adjusted 2014 baseline emissions level (D-E) 589 518 95 61

G

Reductions from baseline measures (A-F) 504 326 4 -8 

% of reductions needed for attainment from 

baseline measures 79.6% 88.1% 30.8% n/a

Reductions needed from control strategy 

measures (C-G)

129 44 9 41

Percent of reductions needed for attainment 

from control strategy measures 20.4% 11.9% 69.2% 124%

California has adopted standards for many categories of on- and off-road vehicles and 

engines, gasoline and diesel fuels, and numerous categories of consumer products. The State‘s 

measures fall within two categories: measures for which the State has obtained or has applied to 

obtain a waiver of federal pre-emption under CAA section 209 (―section 209 waiver measure‖ or 

―waiver measure‖) and those for which the State is not required to obtain a waiver (―non-waiver 
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measure‖). See EPA‘s proposed approval and final approval of the SJV 1-Hour Ozone Plan at 

74 FR 33933, 33938, (July 14, 2009) and 75 FR 10420, 10424 (March 8, 2010).77

i. Section 209 Waiver Measures

A waiver under CAA section 209 is, in general, required for most of California‘s on- and 

nonroad vehicle or engine standards. Examples of State waiver measures are: low emission 

vehicle program, heavy duty bus standards, and small off-road engine standards. A list of 

California‘s waiver measures can be found in the Appendix A of this TSD.

California‘s motor vehicle emissions control program predates the first federal statute 

regulating motor vehicle emissions, the Motor Vehicle Air Pollution Control Act of 1965 (which 

amended the CAA of 1963). In further CAA amendments, referred to as the Air Quality Act of 

1967 (Pub. L. 90-148), Congress allowed the State of California, and only California, a waiver of 

the Air Quality Act‘s pre-emption of state emissions standards for new motor vehicles or new 

motor vehicle engines because of California‘s pioneering efforts and unique problems. This was 

not changed when the statute was amended in 1970. The 1977 amendments to the CAA 

expanded the flexibility granted to California in order ―to afford California the broadest possible 

discretion in selecting the best means to protect the health of its citizens and the public welfare.‖ 

(H.R. Rep. No. 294, 95th Congr., 1st Sess. 301-2 (1977). So long as California determines that 

its motor vehicle standards are ―in the aggregate‖ at least as protective of public health and 

welfare as applicable federal standards, title II of the CAA requires EPA, unless it makes certain 

findings, to waive the Act‘s general prohibition on state adoption and enforcement of standards 

relating to the control of emissions from new motor vehicles or new motor vehicle engines. See 

CAA section 209, subsections (a) and (b).

As part of the 1990 Amendments to the CAA, Congress enacted subsection (e) of section 

209. In nearly identical language to subsections (a) and (b) of section 209, subsection (e) sets 

forth the federal pre-emption of state emissions standards for nonroad vehicles or engines but 

allows the State of California, and only California, a waiver of pre-emption (with certain 

exceptions) under criteria that mirror the section 209(b) waiver provisions for motor vehicles.

In EPA‘s review of the California SIP and its many revisions, EPA has historically 

allowed emissions reduction credit for the motor vehicle emissions standards that are subject to a 

section 209(b) waiver without requiring California to submit the standards themselves to EPA 

for approval as part of the California SIP. In this respect, EPA treated these rules similarly to the 

federal motor vehicle control requirements, which EPA has always allowed states to credit in 

their SIPs without submitting the program as a SIP revision. Since 1990, EPA has treated 

California nonroad standards for which EPA has issued waivers in the same manner as California

motor vehicle standards, i.e., allowing credit for standards subject to the waiver process without 

requiring submittal of the standards as part of the SIP. In so doing, EPA has treated the 

California nonroad standards similarly to the Federal nonroad standards, which are relied upon,

but not included in, various SIPs.

 

77

 EPA position is also discussed in Brief of Respondents, Sierra Club, et al., And Committee for a Better Arvin, et 

al. v. United States Environmental Protection Agency, et al., United States Court of Appeals for the Ninth Circuit, 

Case Nos. 10-71457 and 10-71458, May 5, 2011, pp. 33-44.
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Credit for Federal measures, including those that establish on-road and nonroad 

standards, notwithstanding their absence in the SIP, is justified by reference to CAA section 

110(a)(2)(A), which establishes the following content requirements for SIPs: ―... enforceable 

emission limitations and other control measures, means, or techniques (including economic 

incentives such as fees, marketable permits, and auctions of emissions rights), ... , as may be 

necessary or appropriate to meet the applicable requirements of this chapter.‖ (emphasis added). 

Federal measures are permanent, independently enforceable (by EPA and citizens), and 

quantifiable without regard to whether they are approved into a SIP, and thus EPA has never 

found such measures to be ―necessary or appropriate‖ for inclusion in SIPs to meet the 

applicable requirements of the Act. Section 209 of the CAA establishes a process under which 

EPA allows California‘s waiver measures to substitute for Federal measures, and like the Federal 

measures for which they substitute, EPA has historically found, and continues to find, based on 

considerations of permanence, enforceability, and quantifiability, that such measures are not 

―necessary or appropriate‖ for California to include in its SIP to meet the applicable 

requirements of the Act. 

First, with respect to permanence, we note that, to maintain a waiver, CARB‘s on-road 

waiver measures can be relaxed only to a level of aggregate equivalence to the Federal Motor 

Vehicle Control Program (FMVCP). See section 209(b)(1). In this respect, the FMVCP acts as a 

partial backstop to California‘s on-road waiver measures (i.e., absent a waiver, the FMVCP 

would apply in California). Likewise, Federal nonroad vehicle and engine standards act as a 

partial backstop for corresponding California nonroad waiver measures. The constraints of the 

waiver process thus serve to limit the extent to which CARB can relax the waiver measures for 

which there are corresponding EPA standards, and thereby serve an anti-backsliding function 

similar in substance to those established for SIP revisions in CAA sections 110(l) and 193. 

Meanwhile, the growing convergence between California and EPA mobile source standards 

diminishes the difference in the emissions reductions reasonably attributed to the two programs 

and strengthens the role of the Federal program in serving as an effective backstop to the State 

program. In other words, with the harmonization of EPA mobile source standards with the 

corresponding State standards, the Federal program is becoming essentially a full backstop to 

most parts of the California program.

Second, as to enforceability, we note that the waiver process itself bestows enforceability 

onto California to enforce the on-road or nonroad standards for which EPA has issued the 

waiver. CARB has as long a history of enforcement of vehicle/engine emissions standards as 

EPA, and CARB‘s enforcement program is equally as rigorous as the corresponding EPA 

program. The history and rigor of CARB‘s enforcement program lends assurance to California 

SIP revisions that rely on the emissions reductions from CARB‘s rules in the same manner as 

EPA‘s mobile source enforcement program lends assurance to other state‘s SIPs in their reliance 

on emissions reductions from the FMVCP. While it is true that citizens and EPA are not 

authorized to enforce California waiver measures under the Clean Air Act (i.e., because they are 

not in the SIP), citizens and EPA are authorized to enforce EPA standards in the event that 

vehicles operate in California without either California or EPA certification,

As to quantifiability, EPA‘s historical practice has been to give SIP credit for motorvehicle-related waiver measures by allowing California to include motor vehicle emissions 

estimates made by using California‘s EMFAC (and its predecessors) motor vehicle emissions 
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factor model in SIP inventories. EPA verifies the emissions reductions from motor-vehiclerelated waiver measures through review and approval of EMFAC, which is updated from time to 

time by California to reflect updated methods and data, as well as newly-established emissions 

standards. (Emissions reductions from EPA‘s motor vehicle standards are reflected in an

analogous model known as MOVES, which replaced EPA‘s MOBILE model.) The EMFAC 

model is based on the motor vehicle emissions standards for which California has received 

waivers from EPA but accounts for vehicle deterioration and many other factors. The motor 

vehicle emissions estimates themselves combine EMFAC results with vehicle activity estimates, 

among other considerations. See the 1982 Bay Area Air Quality Plan, and the related EPA 

rulemakings approving the plan (see 48 FR 5074 (February 3, 1983) for the proposed rule and 

48 FR 57130 (December 28, 1983) for the final rule) as an example of how the waiver measures 

have been treated historically by EPA in California SIP actions.78 The South Coast 2007 AQMP

was developed using a version of the EMFAC model referred to as EMFAC2007, which EPA 

has approved for use in SIP development in California. See 73 FR 3464 (January 18, 2008). 

Thus, the emissions reductions that are from the California on-road ―waiver measures‖ and that 

are estimated through use of EMFAC are as verifiable as are the emissions reductions relied 

upon by states other than California in developing their SIPs based on estimates of motor vehicle 

emissions made through the use of the MOVES model.

Moreover, EPA‘s waiver review and approval process is analogous to the SIP approval 

process. First, CARB adopts its emissions standards following notice and comment procedures at 

the state level, and then submits the rules to EPA as part of its waiver request. When EPA 

receives new waiver requests from CARB, EPA publishes a notice of opportunity for public 

hearing and comment and then publishes a decision in the Federal Register following the public 

comment period. Once again, in substance, the process is similar to that for SIP approval and 

supports the argument that one hurdle (the waiver process) is all Congress intended for 

California standards, not two (waiver process plus SIP approval process). Second, just as SIP 

revisions are not effective until approved by EPA, changes to CARB‘s rules (for which a waiver 

has been granted) are not effective until EPA grants a new waiver, unless the changes are ―within 

the scope‖ of a prior waiver and no new waiver is needed. Third, both types of final actions by 

EPA--i.e., final actions on California requests for waivers and final actions on state submittals of 

 

78

 EPA‘s historical practice in allowing California credit for waiver measures notwithstanding the absence of the 

underlying rules in the SIP is further documented by reference to EPA‘s review and approval of a May 1979 

revision to the California SIP entitled, ―Chapter 4, California Air Quality Control Strategies.‖ In our proposed 

approval of the 1979 revision (44 FR 60758, October 22, 1979), we describe the SIP revision as outlining 

California‘s overall control strategy, which the State had divided into vehicular sources and non-vehicular 

(stationary source) controls. As to the former, the SIP revision discusses vehicular control measures as including 

technical control measures and transportation control measures. The former refers to the types of measures we refer 

to herein as waiver measures, as well as fuel content limitations, and a vehicle inspection and maintenance program. 

The 1979 SIP revision included several appendices, including appendix 4–E, which refers to ―ARB vehicle emission 

controls included in title 13, California Administrative Code, chapter 3 * * *,‖ including the types of vehicle 

emission standards we refer to herein as waiver measures; however, California did not submit the related portions of 

the California Administrative Code (CAC) to EPA as part of the 1979 SIP revision submittal. With respect to the 

CAC, the 1979 SIP revision states: ―The following appendices are portions of the California Administrative Code. 

Persons interested in these appendices should refer directly to the code.‖ Thus, the State was clearly signaling its 

intention to rely on the California motor vehicle control program but not to submit the underlying rules to EPA as 

part of the SIP. In 1980, we finalized our approval as proposed. See 45 FR 63843 (September 28, 1980).
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SIPs and SIP revisions—may be challenged under section 307(b)(1) of the CAA in the 

appropriate United States Court of Appeals.

Further statutory support for EPA‘s long-standing practice is found in CAA section 193. 

CAA section 193, enacted as part of the 1990 Amendments to the CAA, is a general savings 

clause that provides for, among other things, EPA statutory interpretations that predate those 

amendments to remain in effect so long as not inconsistent with the Act. At the time it enacted 

section 193, Congress did not insert any language into the statute rendering EPA‘s consistent 

prior treatment of California‘s motor vehicle standards inconsistent with the Act. Moreover, 

where Congress intends state control measures that are otherwise pre-empted under title II of the 

Clean Air Act to be incorporated into SIPs, it has required that explicitly. See, e.g., section 

211(c)(4)(C) (State fuels regulations), section 211(m) (oxygenated gasoline regulations), and 

section 246 (centrally fueled fleets).Thus, in section 193, Congress effectively ratified EPA‘s 

longstanding pre-1990 practice of allowing emissions reduction credit for California standards 

subject to the waiver process notwithstanding the absence of the standards in the SIP itself.

As noted above, under the CAA Amendments of 1990, Congress enacted subsection (e) 

of section 209. In nearly identical language to subsections (a) and (b) of section 209, subsection 

(e) sets forth the federal pre-emption of state emissions standards for nonroad vehicles or engines 

but allows the State of California, and only California, a waiver of pre-emption (with certain 

exceptions) under criteria that mirror the section 209(b) waiver provisions for motor vehicles. 

Congress is presumed to be aware of agency interpretations and its subsequent revision of the 

statute to add subsection (e) without overruling EPA‘s interpretation with respect to motor 

vehicle standards is further compelling evidence that the Agency correctly interpreted 

congressional intent with respect to crediting California requirements subject to a section 209 

waiver without requiring California to submit the standards themselves to EPA for approval as 

part of the California SIP.

We believe that section 193 of the CAA, the general savings clause added by Congress in 

1990, effectively ratified our long-standing practice of granting credit for the California waiver 

rules because Congress did not insert any language into the statute rendering EPA‘s treatment of 

California‘s motor vehicle standards inconsistent with the Act. Rather, Congress extended the 

California waiver provisions to most types of nonroad vehicles and engines, once again 

reflecting Congressional intent to provide California with the broadest possible discretion in 

selecting the best means to protect the health of its citizens and the public welfare. Requiring the 

waiver measures to undergo SIP review in addition to the statutory waiver process is not 

consistent with providing California with the broadest possible discretion as to on-road and 

nonroad vehicle and engine standards, but rather, would add to the regulatory burden California 

faces in establishing and modifying such standards, and thus would not be consistent with 

Congressional intent. In short, we believe that Congress intended California‘s mobile source 

rules to undergo only one EPA review process (i.e., the waiver process), not two. Even if section 

193 did not provide congressional acquiescence as to EPA‘s treatment of the standards, the Act‘s 

structure, evolution, and provision for the waiver of Federal pre-emption for California mobile 

source emissions standards, as discussed above, support EPA‘s long-standing interpretation of 

the CAA to allow California to rely on emission reductions resulting from waiver measures in 

SIPs, notwithstanding the waiver measures‘ absence from the SIP itself.
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ii. Non-waiver measures

These measures include improvements to California‘s inspection and maintenance (I/M) 

program, SmogCheck, as well as cleaner burning gasoline and diesel regulations. A list of these 

non-waiver measures, many of which have been SIP approved, can be found Appendix A.

b. Enforceable Commitments

As stated and shown in Table F-11 below, reductions in the projected baseline inventory 

resulting from the economic recession, changes to activity estimates and emission factors, and 

measures already adopted by the District and State (both prior to and pursuant to the South Coast 

2007 AQMP) and approved or proposed for approval by EPA provide the great majority of 

emission reductions needed to demonstrate attainment of the 1997 PM2.5 standards in the South 

Coast nonattainment area. The balance of the needed reductions is in the form of enforceable 

commitments by CARB and the District. 

We believe that, with respect to the South Coast 2007 AQMP and revised 2007 State 

Strategy, circumstances warrant the consideration of enforceable commitments as part of the 

attainment demonstration for the South Coast nonattainment area. As shown in Table F-10

above, the majority of emissions reductions needed to demonstrate attainment and RFP in the 

South Coast nonattainment area come from rules and regulations that were adopted prior to 

2007, i.e., they come from the baseline measures. As a result of these State and District efforts, 

most sources in the South Coast nonattainment area were already subject to stringent rules prior 

to the State Strategy‘s and the South Coast 2007 AQMP‘s development, leaving fewer and more 

technologically challenging opportunities to reduce emissions in the nonattainment area. In the 

South Coast 2007 AQMP and the 2007 State Strategy, the District and CARB identified potential 

control measures that could achieve the additional emission reductions needed for attainment. 

See South Coast 2007 AQMP, Chapter 4, and 2007 State Strategy, Chapter 5. However, the 

timeline needed to develop, adopt, and implement these measures went well beyond the April 5, 

200879 deadline to submit the PM2.5 attainment plan. As discussed above, the District and State 

have made progress meeting their commitments but have not completely filled them. Given these 

circumstances, we consider the District‘s and CARB‘s reliance in the South Coast 2007 AQMP 

and 2007 State Strategy on enforceable commitments to be warranted. 

Having concluded that the use of enforceable commitments is warranted, we now 

consider the three factors EPA uses to determine whether the use of enforceable commitments in 

lieu of adopted measures to meet a CAA planning requirements is approvable: (a) does the 

commitment address a limited portion of the statutorily-required program; (b) is the state capable 

of fulfilling its commitment; and (c) is the commitment for a reasonable and appropriate period 

of time.

 

79

 The 2007 State Strategy was developed to address both the 1997 PM2.5 NAAQS and the 1997 8-hour ozone 

NAAQS. The 8-hour ozone SIPs were due in November 2007, and the development and adoption of the State 

Strategy was timed to coordinate with this submittal date. 2007 State Strategy, p. 1. 
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Table F-10

Reductions Needed for Attainment Remaining as Commitments Based on 

Approved Measures 

Using Updated Emissions Reductions Estimates

(tons per average annual day in 2014)

NOx VOC PM2.5 SOx

A

Total reductions needed from baseline and 

control strategy measures to attain 633 370 13 33

B Reductions from baseline measures 504 326 4 -8

C

Total reductions needed from new measures and 

commitments 129 44 9 41

Total reductions from approved/waived 

measures and adjustments to baseline (from 

Table F-8)

59 20 8 41

Total reductions remaining as commitments (AB-C)a 70.5 24 1 0

% of total reductions needed remaining as 

commitmentsa, b 11% 7% 8% 0%

Total District commitments 10.8 10.4 3 3

Total reductions from approved District 

measures

4.2 0.8 1 4

Total reductions remaining as District 

commitments 6.6 9.6 2 0

Percent of District‘s commitments remaining as 

commitments compared to overall reductions 

needed

1% 3% 15% 0%

a Remaining NOx enforceable commitments include 10 tpd federal assignment. Remaining VOC enforceable 

commitments include 4 tpd VOC from CARB‘s marine tanks rule, which we have not yet acted on, and 3.9 tpd of 

VOC from SC Rule 1144 and 9.7 tpd of VOC from SC Rule 1143, because we have not completed final action on 

these District rules (see Table F-3 in this TSD) . 

b

Includes local reductions. (see 2011 Progress Report).
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Table F-11

Reductions Needed for Attainment Remaining as Commitments Based on SIPCreditable Measures (tons per average annual day in 2014), based on 2011 

Progress Report and 2011 Progress Report Supplement

NOx VOC PM2.5

SOx

Total CARB commitments 129 44 9 41

Reductions from approved/waived 

measures and adjustments to 

baseline

59 20 8 41

Reductions in excess of District‘s 

commitments 0 0 0 1

Total reductions remaining as CARB 

commitmentsa 70 24 1 0

% of CARB commitments 

remaining as commitments 11% 7% 8% 0%

a

The VOC commitment includes 4 tpd VOC from CARB‘s marine tanks rule, which we have not yet acted on. and 

3.9 tpd of VOC from SC Rule 1144 and 9.7 tpd of VOC from SC Rule 1143, because we have not completed final 

action on these rules (see Table F-3 on p. 79-80 of this TSD) . 

i. The 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 emissions reductions needed for attainment in a 

nonattainment area. 

As shown in Table F-11, the remaining portion of the enforceable commitments after 

accounting for approved and proposed for approval measures, as well as adjustments to the 

baseline that resulted from the recent economic recession are 70 tpd NOx, 24 tpd VOC, and 1

tpd direct PM2.5. When compared to the total reductions needed by 2014 for PM2.5 attainment in 

the South Coast nonattainment area on a per-pollutant basis, the remaining portion of the 

enforceable commitments represents approximately 11 percent of the needed NOx, 7 percent of 

the needed VOC, and 8 percent of the needed PM2.5 needed to attain the 1997 PM2.5 standardsin 

the South Coast. 

We believe that the reductions remaining as enforceable commitments in the South Coast 

2007 AQMP and updated 2007 State Strategy represent a limited portion of the total emissions 

reductions needed to meet the statutory requirement for attainment in the South Coast and 

therefore satisfy the first factor. The level of reductions remaining as commitments is within the 
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range of 10 percent or less that EPA has historically accepted in approving attainment 

demonstrations.80

ii. The State is Capable of Fulfilling Its Commitment

For the second factor, we consider whether the State and District are capable of fulfilling 

their commitments. 

As discussed above, CARB has adopted and submitted a 2009 State Strategy Status 

Report and a 2011 Progress Report which update and revise the 2007 State Strategy. These SIP 

revisions show that CARB has made significant progress in meeting its enforceable 

commitments for the South Coast and several other nonattainment areas in California. Additional 

ongoing programs that addresses locomotives and revisions to the SmogCheck program have yet 

to be quantified but are expected to reduce NOx and direct PM2.5 emissions in the South Coast 

by 2014. See CARB Supplement, Attachment 5. The 2009 State Strategy Status Report includes 

a table with estimates of the reductions that may fulfill the CARB‘s full commitment. See 2009 

State Strategy Status Report, p. 17.

The District has also made good progress in meeting its enforceable commitments and 

has exceeded its emissions reduction commitments for SOx and VOC. The District‘s continued 

efforts in committing to and adopting measures for sources under its jurisdiction will help the 

District fully meet its commitments. The District has also already adopted rules that are projected 

to achieve NOx reductions of 10.8 tpd in 2014. See Table F-4 above. The District is continuing 

to work to identify and adopt additional control measures to reduce emissions. 

Beyond the rules 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 several of these programs have yet to be quantified and/or credited in the attainment 

demonstration. 

Finally, the South Coast is designated nonattainment for the 2006 24-hour PM2.5

standard. The State must submit a plan to address attainment of that standard by December 14, 

2012. See 74 FR 58688, 58689, (November 13, 2009).

Given the evidence of the State's and District‘s efforts to date and their continuing efforts 

to reduce emissions, we believe that the State and District are capable of meeting their 

enforceable commitments to reduce emissions of directly-emitted PM2.5, NOx, VOC and SOx to 

the levels needed to attain the PM 2.5 standards in the South Coast nonattainment area by 2014. 

iii. The Commitment is for a Reasonable and Appropriate Timeframe

 

80 See, for example, our approval of the SJV PM10 Plan at 69 FR 30005 (May 26, 2004), the SJV 1-hour ozone plan 

at 75 FR 10420 (March 8, 2010), and the Houston-Galveston 1-hour ozone plan at 66 FR 57160 (November 14,

2001).
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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 reduce emissions to the levels needed to attain the 

1997 PM2.5 standards in the South Coast by 2014, the South Coast 2007 AQMP and 2007 State 

Strategy include ambitious rule development, adoption, and implementation schedules, which 

both the District and CARB have substantially met. EPA considers these schedules to provide 

sufficient time to achieve the committed reductions by 2014 as needed to attain by the proposed 

attainment date of April 5, 2015. See Tables F-3 and F-6 above. We therefore conclude that the 

third factor is satisfied.

iv. Summary of Finding on Enforceable Commitments in the South Coast 2007 AQMP

EPA believes circumstances warrant the consideration of enforceable commitments as 

part of the attainment demonstration in the South Coast 2007 AQMP and updated 2007 State 

Strategy. As stated above, measures already adopted by the District and State and approved or 

proposed for approval pursuant to CAA section 110(k) or waived pursuant to CAA section 209 

by EPA provide the great majority of emissions reductions needed to demonstrate attainment of 

the 1997 PM2.5 standards in the South Coast by 2015. We have found that the reductions that 

remain as enforceable commitments represent a limited portion of the overall reductions needed 

for attainment. We have also found that the State and District are capable of fulfilling their

remaining commitments and that the commitments are for a time period that is both reasonable 

and appropriate to assure that the remaining reductions are in place prior to the attainment date of 

April 5, 2015. As a result of our findings here, EPA is accepting enforceable commitments as 

part of California‘s strategy to attain the 1997 PM2.5 NAAQS in the South Coast.

v. Action on Enforceable Commitments to Reduce Emissions and Adopt Specific 

Measures

We are approving the District‘s commitments to adopt and implement specific control 

measures identified in Table 4-2A in the South Coast 2007 AQMP (as amended March 4, 2011

by Tables 1 through 5 of Appendix F in the 2011 Progress Report), to the extent that these 

commitments have not yet been fulfilled, and commitments to achieve emissions reductions 

including emissions reductions of 2.9 tpd of direct PM2.5, 10.8 tpd of NOx, 10.4 tpd of VOC, 

and 2.9 tpd of SOx by 2014. 

We are also approving CARB's commitments to propose certain defined measures, as 

given in Table B-1 in the 2011 Progress Report, Appendix B, to the extent that these

commitments have not yet been fulfilled, and to achieve the total aggregate emissions reductions

of NOx, VOC, direct PM2.5, and SOx by 2014 sufficient to provide for attainment of the 1997 

PM2.5 standards in the South Coast PM2.5 nonattainment area. See CARB Resolution 07-28 

(September 27, 2007), Appendix B, p. 3-5. We describe CARB‘s and the District‘s commitments 

in the 2007 State Strategy (revised in 2009 and 2011) and the 2007 AQMP in detail in our 

amended proposal. See 76 FR 41562, at 41575. The 2007 State Strategy includes commitments 

to propose defined new measures and an enforceable commitment for emissions reductions 

sufficient, in combination with existing measures and the District‘s commitments, to attain the 

PM2.5 NAAQS in the South Coast by April 5, 2015. See CARB Resolution 07-28, Attachment B 
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at pp. 3-5. For the South Coast, the State‘s emissions reductions commitments as submitted in 

2007 were to achieve 152 tpd NOx, 46 tpd of VOC, 20 tpd of SOx and 9 tpd of direct PM2.5 by 

2014. See 2009 State Strategy Status Report, page 20. The 2011 SIP revisions changed the total 

amount of reductions needed from control strategy measures in 2014 to 129 tpd of NOx

reductions, 44 tpd of VOC reductions, and 41 tpd of SOx reductions (the PM2.5 enforceable 

commitment stayed the same at 9 tpd of directly-emitted PM2.5). See Table F-10.

We received a number of comments on our proposed approval of the adopted control 

strategy and our proposed acceptance of enforceable commitments in the attainment 

demonstration. We have reviewed these comments and provided responses to them. See section 

III of this TSD. No issues raised in these comments changed our finding that the adopted control 

strategy and enforceable commitments in the South Coast 2007 AQMP and revised 2007 State 

Strategy are consistent with the applicable requirements of the CAA and EPA guidance.
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G. Attainment Demonstration

1. Requirement for Attainment Demonstrations

CAA section 172(b) and (c) require states to submit plans that demonstrate attainment of 

the applicable standard as expeditiously as practicable but no later than the applicable attainment 

date. Under the PM2.5 implementation rule, this demonstration should consists of four parts:

(1) technical analyses that locate, identify, and quantify sources of emissions that are 

contributing to violations of the PM2.5 NAAQS; 

(2) analyses of future year emissions reductions and air quality improvement resulting 

from already-adopted national and local programs, and from potential new local measures 

to meet the RACT, RACM, and RFP requirements in the area; 

(3) adopted emissions reduction measure with schedules for implementation; and 

(4) contingency measures required under section 172(c)(9) of the CAA.

See 72 FR 20586 (April 25, 2007), at 20605.

The requirements for parts 1 and 2 are described in the emissions inventory (II.A.), air 

quality modeling (II.B.), and RACM/RACT (II.D.) sections of this TSD. Requirements for parts 

3 and 4 are described in the control strategy (II.F.) and contingency measures (II.I.) sections of 

this TSD, respectively. In this section, we evaluate how these parts taken together provide for 

attainment of the 1997 PM2.5 NAAQS in the South Coast as expeditiously as practicable but no 

later than the attainment date required by the CAA.

2. Attainment Demonstration in the South Coast 2007 AQMP

The attainment demonstration in the South Coast 2007 AQMP is in Chapter 5, ―Future 

Air Quality,‖ with additional technical information in Appendix V of the AQMP. It is 

summarized in Table G-1 below. Table G-2 shows the contribution by the District and CARB to 

the control strategy as given in the South Coast 2007 AQMP as submitted in November 2007.

Since adoption and submittal of the 2007 State Strategy and the South Coast 2007 

AQMP, both CARB and the District have adopted most of the measures that they committed to 

adopt in their plans, and most have been approved, proposed for approval, or granted a CAA 

section 209 waiver by EPA. See Tables F-3 and F-6. In the 2011 Progress Report, CARB and 

the District have updated the emissions reductions expected from their adopted measures and 

resulting from changes to the inventory and the economic recession. Table G-3 shows the impact 

of these updates on the attainment demonstration, and Table G-4 shows the effect of these 

updates and EPA‘s proposed and final approvals on the level of commitments remaining in the 

attainment demonstration. 
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Table G-1

Summary of the Attainment Demonstration, South Coast 2007 AQMP, as 

Submitted in November 2007 (tons per average annual day in 2014)

NOx VOC

Directly 

Emitted 

PM2.5

SOx

A 2006 baseline emissions level 972 732 101 63

B 2014 attainment target level* 460 474 86 20

C

Total reductions needed from 2006 baseline 

levels to attain in 2014 (A – B) 512 258 15 43

D 2014 baseline emissions level 654 528 102 43

Reductions from baseline measures (A-D) 318 204 (-1) 20

% of reductions needed for attainment from 

baseline measures 62% 79% n/a 47%

Reductions needed from control strategy 

measures (D - B)

194 59 16 23

% of reductions needed for attainment from 

control strategy measures 38% 23% 106% 53%

*The South Coast 2007 AQMP and the 2009 State Strategy use slightly different attainment targets. The CARB 

Staff Report for the South Coast 2007 AQMP presents a slightly different emissions carrying capacity which relies 

more heavily on reductions of primary PM2.5 and less heavily on reductions of precursors to PM2.5. The Staff 

Report's emission carrying capacity estimates are PM2.5 - 86 tons/day, NOx - 460 tons/day, SOx - 20 tons/day, and 

VOC - 474 tons/day (see CARB Staff Report on the South Coast AQMP, page ES-3). Therefore, the percentage 

reductions needed for attainment in this table may not add up to 100%. In the proposed rule and this TSD, we use 

the CARB Staff Report carrying capacity numbers.
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Table G-2. Summary of Control Strategy Reductions by Agency

South Coast 2007 AQMP as Submitted November 2007

(tons per average annual day in 2014)

NOx VOC

Directly 

Emitted

PM2.5

SOx

Total reductions needed from baseline and 

control strategy measures to attain 512 258 15 43

Total reductions from control strategy measures 194 53 16 23

District commitments 32 10 4 3

Percent of total control strategy reductions from 

District commitments 17% 19% 25% 13%

State commitments* 152 46 9 20

Percent of total control strategy reductions from 

State commitments 78% 87% 56% 87%

Federal assignment**

10 (5%) -- -- --

* The 2007 State Strategy identifies 9 tpd of directly-emitted PM2.5 as the aggregate State commitment by the 2015 

attainment date (see 2009 State Strategy Status Report, page 20) but the CARB staff report for the South Coast 2007 

AQMP indicates a 12 tpd commitment. (see 2007 Staff Report, page ES-3) It is unclear whether the State‘s 

commitment is for 9 tpd direct PM2.5 or 12 tpd of direct PM2.5.

**The AQMP assigns 10 tpd of NOx reductions to the federal government. We are rejecting this assignment.
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Table G-3. Summary of the Attainment Demonstration

Updated April 2011 with Additional Adjustments

(tons per average annual day in 2014)

PM2.5 NOx VOC SO2

A 2002 baseline emissions level 99 1093 844 53

B 2014 attainment target level 86 460 474 20

C

Total reductions needed from 2002

baseline levels to attain in 2014 (A – B) 13 633 370 33

D Unadjusted 2014 baseline emissions level 102 654 528 43

E

Adjustment to 2014 baseline emissions 

level 7 65 10 -18

F

Adjusted 2014 baseline emissions level 

(D–E) 94 589 518 65

Reductions from baseline measures (A-F) 4 504 326 -8

Percent of reductions needed for 

attainment from baseline measures 30.7% 79.6% 88.1% 0

Reductions needed from control strategy 

measures (B –F) 9 129 44 41

Percent of reductions needed for 

attainment from control strategy measures

69.2% 20.3% 11.9% 124%
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Table G-4. Summary of the Attainment Remaining as Commitments based on 

Approved Measures using Updated Emissions Reductions Estimates

(tons per average annual day in 2014)

NOx VOC PM2.5 SOx

A

Total reductions needed from baseline and 

control strategy measures to attain 633 370 13 33

B

Reductions from baseline measures (Table 

F-10) 504 326 4 -8

C

Reductions needed from control strategy 

measures

129 44 9 41

D

Total reductions from approved/proposed for 

approval measures (Tables F-4 and F-9) 59 20 8 41

E

Total reductions remaining as commitments

(A-B-D)

a, b 70 24 1 0

Percent of total reductions needed remaining 

as commitmentsa, b 11% 7% 8% 0%

E Total District commitments 10.8 10.4 3 3

F Total reductions from approved/proposed for 

approval District measures 4.2 0.8 1 4

G Total reductions remaining as District 

commitments 6.6 9.6 2 0

Percent of District‘s commitments remaining 

as commitments 1% 3% 15% 0%

a Includes the District‘s and State‘s backstop for the 10 tpd NOx federal assignment.

b

The VOC commitment includes 4 tpd VOC from CARB‘s marine tanks rule, which we have not yet acted on. and 

3.9 tpd of VOC from SC Rule 1144 and 9.7 tpd of VOC from SC Rule 1143, because we have not completed final 

action on these rules (see Tables F-2 and F-3 and footnote b to Table F-3). 

3. Proposed Actions on the Attainment Demonstration in the 2007 South Coast AQMP

In November 2010, we proposed to disapprove the attainment demonstration in the 2007 

South Coast AQMP based on our proposed disapproval of the RACM/RACT demonstration and 

our proposal to deny the State‘s request to extend the attainment date for the South Coast until

April 5, 2015. EPA also proposed to disapprove the attainment demonstration because, at the 

time of the 2010 proposal, the State‘s and District‘s unfulfilled commitments represented

89 percent of the direct PM2.5 reductions, 28 percent of the NOx reductions, 18 percent of the 

VOC reductions, and 53 percent of the SOx emissions reductions required for attainment. These 

percentages were well above the roughly 10 percent figure generally acceptable in order for EPA

to approve an attainment demonstration that relies in part on enforceable commitments.

75 FR 71294, 71314 and Section II.D. of the November 2010 TSD.
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In our July 2011 amended proposal, we proposed to approve the attainment 

demonstration in the 2007 South Coast AQMP based on our proposed approval of the 

RACM/RACT demonstration and our proposal to grant the State‘s request to extend the 

attainment date to April 5, 2015. We also found in our July 2011 amended proposal that 

circumstances warranted the consideration of enforceable commitments in the attainment 

demonstration, and that the State is capable of meeting the commitments, that the commitments 

are for an appropriate time frame, and that the commitments constitute a limited portion of the 

required emissions reductions.

4. Evaluation and Conclusion

In order to approve a SIP‘s attainment demonstration, EPA must make several findings 

and approve the State‘s requested attainment date.

First, we must find that the demonstration‘s technical bases - emissions inventories and 

air quality modeling - are adequate. As discussed above in sections II.A. and II.B., we find that

the emissions inventories and the air quality modeling on which the South Coast 2007 AQMP‘s 

attainment demonstration is based meet applicable EPA regulations and guidance and are an 

acceptable basis for the demonstration.

Second, we must find that the SIP provides for expeditious attainment through the 

implementation of all RACM and RACT on direct PM2.5 and each PM2.5 attainment plan

precursor. As discussed above in section II.D., we are approving the RACM/RACT 

demonstration in the South Coast 2007 AQMP .

Third, EPA must find that the emissions reductions that are relied on for attainment are 

creditable. As discussed in section II.F., the South Coast 2007 AQMP relies principally on 

adopted and approved/waived rules to achieve the emissions reductions needed to attain the 1997 

PM2.5 standards in the South Coast by April 5, 2015. The balance of the reductions is currently 

in the form of enforceable commitments that account for 8 percent of the directly-emitted PM2.5, 

11 percent of the NOx, and 7 percent of the VOC needed from 2002 levels for attainment. See 

Table G-4.

EPA has previously accepted enforceable commitments in lieu of adopted control 

measures in attainment demonstrations when the circumstances warrant it and the commitments 

meet three criteria. As discussed above in section II.F.4, we believe that circumstances here 

warrant the consideration of enforceable commitments and that the three criteria are met: 1) the 

commitments constitute a limited portion of the required emissions reductions, 2) both the State 

and the District have demonstrated their capability to meet their commitments, and 3) the 

commitment are for an appropriate timeframe. Based on these conclusions, we are allowing the 

State to rely on these limited enforceable commitments in its attainment demonstration.

Finally, for a PM2.5 nonattainment area that cannot attain with five years of its 

designation as nonattainment, EPA must grant an extension of the attainment date in order to 

approve the attainment demonstration for the area. As discussed above in section II.E., we 

believe that an five–year extension of the attainment date is appropriate since it is supported by 
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the necessary analysis. We are therefore granting the State‘s request to extend the attainment 

date in the South Coast PM2.5 nonattainment area to April 5, 2015. For the foregoing reasons, we 

are approving the attainment demonstration in the South Coast 2007 AQMP.

We received several comments on our proposed approval of the attainment 

demonstration. We have reviewed these comments and provided responses to them. See section 

III of this TSD. No issues raised in these comments changed our finding that the attainment 

demonstration in the South Coast 2007 AQMP and revised 2007 State Strategy are consistent 

with the applicable requirements of the CAA and EPA guidance.
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H. Reasonable Further Progress Demonstration

1. Requirements for Reasonable Further Progress Demonstrations

Clean Air Act section 172(c)(2) requires that plans for nonattainment areas shall provide 

for reasonable further progress (RFP). RFP is defined in section 171(1) as ―such annual 

incremental reductions in emissions of the relevant air pollutant as are required by this part [Part 

D] or may reasonably be required by the Administrator for the purpose of ensuring attainment of 

the applicable [NAAQS] by the applicable date.‖

The PM2.5 implementation rule requires a state to submit an RFP plan at the same time as 

its attainment demonstration for any area for which the state requests an extension of the 

attainment date beyond 2010. The RFP plan must provide emission reductions such that 

emissions in 2009 represent generally linear progress from the baseline year to the attainment 

year. Where a state requests an extension of the attainment deadline to 2014 or 2015, the state 

must additionally provide emission reductions such that emissions in 2012 represent generally 

linear progress from the baseline year to the attainment year. See 40 CFR § 51.1009(c). 72 FR 

20586 at 20633

The RFP plan must describe the control measures that provide for meeting the reasonable 

further progress milestones for the area, the timing of implementation of those measures, and the 

expected reductions in emissions of direct PM2.5 and all PM2.5 attainment plan precursors. See 

40 CFR § 51.1009(c).

A state is also required to demonstrate in its RFP plan that in each applicable milestone 

year, emissions will be at a level consistent with generally linear progress in reducing emissions 

between the base year and the attainment year. See 40 CFR § 51.1009(d). A state may 

demonstration this by showing that emissions for each milestone year are either 1) roughly 

equivalent to benchmark emission levels for direct PM2.5 emission and each PM2.5 attainment

plan precursor addressed in the plan or 2) at levels included in an alternative scenario that is 

projected to result in a generally equivalent improvement in air quality by the milestone year as 

would be achieved under the first option. See 40 CFR § 51.1009(g). 72 FR 20586 at 20639.

The steps for determining the benchmark emissions levels is given in the PM2.5

implementation rule in 40 CFR § 51.1009(f):

(1) For direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the 

attainment strategy, the full implementation reduction is calculated by subtracting the full 

implementation inventory from the baseline year inventory. The full implementation 

inventory is the projected RFP emission inventory for the year preceding the attainment 

date, representing a level of emissions that demonstrates attainment. The baseline year 

inventory is the emissions inventory for the year also used as the base year for the 

attainment demonstration (see 40 CFR § 51.1000).

(2) For direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the 

attainment strategy, a benchmark emission reduction is calculated by multiplying the full 

implementation reduction by the milestone date fraction. The milestone date fraction is 
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the ratio of the number of years from the baseline year to the milestone inventory year 

divided by the number of years from the baseline year to the full implementation year.

(3) The benchmark emission level in the milestone year is calculated for direct PM2.5

emissions and each PM2.5 attainment plan precursor by subtracting the benchmark 

emission reduction from the baseline year emission level. The benchmark RFP plan is 

defined as a plan that achieves benchmark emission levels for direct PM2.5 emissions and 

each PM2.5 attainment plan precursor addressed in the attainment strategy for the area.

In comparing inventories between baseline and future years for direct PM2.5 emissions 

and each PM2.5 attainment plan precursor, the inventories must be derived from the same 

geographic area. The plan must include emissions estimates for all types of emitting sources and 

activities in the geographic area from which the emission inventories for direct PM2.5 emissions 

and each PM2.5 attainment plan precursor addressed in the plan are derived. See 40 CFR § 

51.1009(f)(5).

The equivalence of an alternative scenario to the corresponding benchmark plan must be 

determined by comparing the expected air quality changes of the two scenarios at the design 

value monitor location. This comparison should use the information developed for the attainment 

plan to assess the relationship between emissions reductions of the direct PM2.5 emissions and 

each PM2.5 attainment plan precursor addressed in the attainment strategy and the ambient air

quality improvement for the associated ambient species. See 40 CFR § 51.1009(h).

2. RFP Demonstration in the South Coast 2007 AQMP

The RFP demonstration is in Chapter 6 of the South Coast 2007 AQMP and is updated 

and revised in Appendix C of the 2011 Progress Report. The demonstration addresses NOx, 

VOC, direct PM2.5, and SOx and uses the 2002 annual average day inventory as the baseline year 

inventory and 2014 as the attainment year. The State is requesting an extension of the attainment 

date until April 5, 2015, which means 2014 is the attainment year for the purposes of the RFP 

benchmark calculation.

Table H-1 shows the calculation of full implementation reductions, the first step in 

determining the RFP benchmarks under the PM2.5 implementation rule.

Table H-2 provides the benchmark calculations from the Plan. The State is requesting an 

extension of the attainment date until April 5, 2015 which means 2014 is the attainment year for 

the purposes of the RFP benchmark calculation. The 2014 attainment year is 12 years from the 

2002 base year, making the 2009 milestone date fraction 7/12 and the 2012 milestone date 

fraction 10/12.

Table H-3 provides the updated RFP demonstration from the 2011 Progress Report.
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Table H-1

Full Implementation Reductions in 2007 AQMP

(tons per average annual day)

Direct PM2.5 NOx VOC SO2

2002 base year inventory 99 1093 844 53

2014 attainment target emissions 

level (full implementation 

inventory)

86 460 474 20

Full implementation reductions for 

attainment 13 633

370

33

Source: South Coast 2007 AQMP, page 6-11.

Table H-2

Benchmark Calculations for 2007 AQMP

(tons per average annual day)

Direct PM2.5 NOx VOC SO2

A. Full implementation reductions 13 633 370 33

B. 2009 milestone date fraction (7/12) 0.58 0.58 0.58 0.58

C. 2009 benchmark emissions 

reductions (A * B) 7.6 367 215 19

D.

2009 benchmark emissions level

(2002 baseline inventory – C)

91.4 726 629 34

E. 2012 milestone date fraction 

(10/12) 0.83 0.83 0.83 0.83

F. 2012 benchmark emissions 

reductions (A * E) 10.8 525 307 27

G. 2012 benchmark emissions level

(2002 baseline inventory – F) 88.2 568 537 26

H. Annual reductions needed for linear 

progress (1/12 *A) 1.1 52.8 30.8 2.8

I.

Percent annual reductions needed 

for linear progress (

1

/12 *A/2002

baseline inventory)

1% 4.8% 3.5% 5.4%

Source: South Coast 2007 AQMP, Page 6-11.
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Table H-3 - Revised RFP Calculations in 2011 Progress Report

(tons per average annual day)

NOx VOC PM2.5 SOx

1

2002 baseline inventory (tpd) 1093 844 99 53

2

Annual percentage change needed to show linear 

progress (%) 4.9% 3.7% 1.0% 5.4%

3 One year‘s RFP 52.8 30.8 1.1 2.8

4

2009 target needed to show linear progress (tpd)

724 628 91 34

5

2009 remaining emissions with plan (tpd) 677 563 89 43

6 Projected shortfall (tpd)a+47 +65 +2 9

7

2012 target needed to show linear progress (tpd)

566 534 88 26

8

2012 remaining emissions with plan (tpd) 582 514 89 26

9 Projected shortfall (tpd) 16 +20 +1 0

10 2014 remaining emissions with plan (tpd) 460 474 86 20

Source: 2011 Progress Report, Appendix C, Table C-2. 

aA + value in the ―projected shortfall‖ cell means excess reduction.

3. Proposed Actions on the RFP Demonstration in the South Coast 2007 AQMP

Based on our proposed disapproval of the attainment demonstration in the South Coast 

2007 AQMP in November of 2010, EPA proposed to disapprove the RFP demonstration in the 

South Coast 2007 AQMP. 

However, EPA also determined that the plan met generally linear progress, and should 

the State fix the deficiencies in the attainment demonstration, we believed we could approve the 

RFP demonstration. See 75 FR 72194, at 71310 and section II.H of the November 2010 TSD.

In our July 2011 amended proposal, based on our proposed concurrence with the State‘s 

determination that NOx, VOC, and SOx are attainment plan precursors, our proposed granting of 

the State‘s request to extend the attainment date to April 5, 2015, and our proposed approval of 

the attainment demonstration, we proposed to find that the South Coast 2007 AQMP provides for 

reasonable further progress as required by CAA section 172(c)(2) and 40 CFR 51. 1009 and that 

the South Coast nonattainment area has met its 2009 RFP benchmarks.
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4. EPA‘s Evaluation and Conclusion

Because California has requested an attainment date of April 5, 2015 for the South Coast, 

the Plan has addressed RFP for both 2009 and 2012 as required by 40 CFR § 51.1009(c)(2).

The South Coast 2007 AQMP describes in Chapter 4 (Tables 4-1, 4-2 and 4-10) and 

Chapter 7 (Table 7-3) the non-baseline control measures that are relied on to meet the reasonable 

further progress milestones for the area, the timing of implementation of these measures, and the 

expected reductions in emissions of direct PM2.5 and PM2.5 attainment plan precursors as 

required by 40 CFR § 51.1009(c).

In comparing inventories between baseline and future years for direct PM2.5 emissions 

and each PM2.5 attainment plan precursor addressed in the 2007 AQMP, the inventories are 

derived from the same geographic area. The 2007 AQMP includes emissions estimates for all 

sources and activities in the South Coast area from which the emissions inventories for direct 

PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the Plan are derived as 

required by 40 CFR § 51.1009(f).

In preparing its RFP demonstration, the State followed the procedures in by 40 CFR § 

51.1009(f) and correctly calculated the benchmark emissions levels. 

EPA has reviewed the revised RFP demonstration in the 2011 Progress Report and has 

determined that it was prepared consistent with applicable EPA regulations and policies. See 

Section II.H of the TSD. As can be seen from Table H-1 above, the RFP demonstration for 2009 

shows that the area has a shortfall of 9 tpd of SOx, while NOx, direct PM2.5 and VOC 

reductions exceed their linear targets. The RFP demonstration for 2012 indicates a slight 

shortfall in meeting the 2012 milestones for NOx (16 tpd) and direct PM2.5 (1 tpd), although the 

VOC target is not only met but surpassed. While the shortfall of 9 tpd for SOx in 2009 is 

significant, this shortfall is made up by the reductions estimated for 2012, and the area meets its 

2012 SOx milestone. We note that the shortfall in 2012 for NOx is less than 1% of the 2002 

baseline inventory, and the shortfall in PM2.5 reductions in 2012 is also about 1% of the 2002 

baseline inventory, while 2012 SOx reduction milestones are met and 2012 VOC reduction 

milestones are exceeded by 20 tpd.

Based on our evaluation summarized above, we find that the South Coast 2007 AQMP 

provides for reasonable further progress as required by CAA section 172(c)(2) and 40 CFR § 

51.1009.

We received a comment on our proposed approval of the RFP demonstration. We have 

reviewed this comment and provided our response. See section III of this TSD. No issues raised 

in this comment changed our finding that the attainment demonstration in the South Coast 2007 

AQMP and revised 2007 State Strategy are consistent with the applicable requirements of the 

CAA and EPA guidance.
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Estimated Effect of Base Year Inventory Changes on the South Coast 2007 AQMP’s RFP 

Demonstrations

As discussed in section II.A. of this TSD, CARB has updated the inventories for several 

mobile source categories including off-road equipment and heavy duty diesel trucks and 

estimates that these updates reduce the 2002 base year inventory by approximately 4 percent for 

NOx, 5 percent for PM2.5, 2 percent for VOC, and increase the SOx inventory by 23 percent . See

CARB Progress Report Supplement, Attachment 1. The State, however, did not revise the RFP 

demonstration in the South Coast 2007 AQMP to incorporate these adjustments into the base 

year inventories.

As shown in Tables H-4, and H-5 below, we have evaluated the effect on the RFP 

demonstration of making these minor adjustments to the 2002 base year inventory. As can be 

seen from these tables, the Plan still provides for RFP with these adjustments.

Table H-4. Estimated Effect of Changes to the 2002 Base Year

Inventory on the RFP Demonstration – Milestone Calculation

(tons per average annual day)

Direct

PM2.5

NOx VOC SOx

A. 2002 base year inventory 99 1093 844 53

B.

Adjusted base year inventory assuming 5% 

reduction in PM2.5, 4% reduction in NOx, 2% 

reduction in VOC, 23% increase in SOx

94 1046 827 65

C. Attainment level 86 460 464 20

D.

Adjusted full implementation reductions (BD) 8 586 363 45

E. 2009 milestone date fraction (7/12) 0.58 0.58 0.58 0.58

F. Adjusted 2009 benchmark emissions 

reductions (D * E)

4.7 340 210 26

G.

Adjusted 2009 benchmark emissions level

(B-F) 89.3 804 616 39 

H. 2012 milestone date fraction (10/12) 0.83 0.83 0.83 0.83

I.

Adjusted 2012 benchmark emissions 

reductions (D * H)

6.7 486 301 37
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J.

Adjusted 2012 benchmark emissions level 

(adjusted 2002 baseline inventory – F) 87.3 560 526 28

K.

Annual reductions needed for linear progress 

(

1

/12 *D) 0.67 48.8 30 3.8

L.

Percent annual reductions needed for linear 

progress (1/12 *D / adjusted 2002 base year

inventory)

<1% 4.7% 2.8% 5.8%

Table H-5

Estimated Effect of Changes to the 2002 Base Year

Inventory on RFP Demonstration 

(tons per annual average day)

Direct

PM2.5

NOx VOC SOx

2009

Adjusted benchmark emissions level 89.3 706 616 39

Projected controlled emissions level 89 677 563 43

Emissions below benchmark emissions level -0.3 -29 -53 +4

Percent below/above benchmark emissions 

level -<1% -3.9% -8.6% +10%

2012

Benchmark emissions level 87.3 560 526 28

Projected controlled emissions level 88 582 514 26

Emissions below/above benchmark emissions 

level +0.6 +22 -12 -2

Percent below/above benchmark emissions 

level +<1% +3.9% -2.3% -7%

+ means above the benchmark, - means below the benchmark.

EarthJustice Petition on the PM2.5 Implementation Rule

In June 2007, a petition to the EPA Administrator was filed on behalf of several public 

health and environmental groups requesting reconsideration of several provisions in the PM2.5

implementation rule. See EarthJustice, ―Petition for Reconsideration in the Matter of the Final 

Clean Air Fine Particulate Implementation Rule,‖ June 25, 2007. Among these provisions is 
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allowing states to use emissions reductions from outside of the nonattainment area to 

demonstration RFP (out-of-area RFP) as discussed in 72 FR 20586 at 20636. On May 13, 2010, 

EPA granted the petition with respect to this issue. See Letter, Gina McCarthy, Assistant 

Administrator for Air and Radiation, EPA, to David Baron and Paul Cort, EarthJustice, 

May 13, 2010. The updated South Coast 2007 AQMP does not rely on out-of-area emissions 

reductions to demonstrate RFP.
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I. Contingency Measures

1. Requirement for Contingency Measures

Under CAA section 172(c)(9), all PM2.5 attainment plans must include contingency 

measures to be implemented if an area fails to meet RFP (RFP contingency measures) and 

contingency measures to be implemented if an area fails to attain the PM2.5 NAAQS by the 

applicable attainment date (attainment contingency measures). See 40 CFR § 51.1012. The 

purpose of contingency measures is to continue progress in reducing emission while the SIP is 

being revised to meet the missed RFP milestone or correct continuing nonattainment.

The principal requirements for contingency measures are: 

Contingency measures must be fully adopted rules or control measures that are 

ready to be implemented quickly upon failure to meet RFP or failure of the area to 

meet the standard by its attainment date. 

The SIP should contain trigger mechanisms for the contingency measures, specify 

a schedule for implementation, and indicate that the measures will be 

implemented without further action by the State or by EPA. 

The contingency measures should consist of other control measures for the area 

that are not included in the control strategy for the SIP. 

The measures should provide for emission reductions equivalent to about 1 year 

of reductions needed for RFP, based on the overall level of reductions needed to 

demonstrate attainment divided by the number of years from the base year to the 

attainment year. 

See 72 FR 20586 (April 25, 2007), at 20643.

The April 16, 1992 General Preamble (57 FR 13498, 13512) provided the following 

guidance on contingency measures which continues to be applicable: 

States must show that their contingency measures can be implemented without further 

action on their part and with no additional rulemaking actions such as public hearings or 

legislative review. In general, EPA will expect all actions needed to affect full 

implementation of the measures to occur within 60 days after EPA notifies the State of its 

failure.

Contingency measures can include both Federal, state and local measures already 

scheduled for implementation or already implemented. The CAA requires contingency measures 

that provide for additional emissions reductions that are not relied on for RFP or attainment and 

are not included in these demonstrations. In other words, contingency measures are intended to 

achieve reductions over and beyond those relied on in the RFP and attainment demonstrations. 

Nothing in the CAA precludes a state from implementing such measures before they are 
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triggered. EPA has approved numerous SIPs under this interpretation. See, for example, 

62 FR 15844 (April 3, 1997) (direct final rule approving Indiana ozone SIP revision); 

62 FR 66279 (December 18, 1997) (final rule approving Illinois ozone SIP revision); 

66 FR 30811 (June 8, 2001) (direct final rule approving Rhode Island ozone SIP revision); 

66 FR 586 (January 3, 2001) (final rule approving District of Columbia, Maryland, and Virginia 

ozone SIP revisions); and 66 FR 634 (January 3, 2001) (final rule approving Connecticut ozone 

SIP revision). A court has upheld this interpretation. See LEAN v. EPA, 382 F.3d 575, 5th 

Circuit, 2004.

2. Contingency Measures in the South Coast 2007 AQMP 

The attainment plan for the South Coast includes contingency measures to be 

implemented if the area fails to meet RFP requirements or fails to attain by its attainment date. 

The South Coast contingency measures are described in Chapter 9 of the South Coast 2007 

AQMP and discussed in more detail in Appendix IV-A, section 2 of the AQMP. They are 

described below.

CARB discusses the contingency measure provision in Appendix D of the 2007 State 

Strategy. This discussion is addresses the contingency measure provisions for California‘s 8-

hour ozone plans and not the PM2.5 plans. Updated information on the attainment contingency 

measures for the South Coast 2007 AQMP is provided in the 2011 Progress Report. This 

information includes updated estimates of the reductions in 2015 from the State‘s mobile source 

control program. See 2011 Progress Report, Appendix A, p. 2, and Appendix C, Table C-2 and 

CARB Supplement, Attachment 2.

The South Coast 2007 AQMP describes the contingency measures in the following way, 

―Although implementation of these measures is expected to reduce emissions, there are issues 

that limit the viability of these measures as AQMP control measures at this time. Issues 

surrounding these measures include, but are not limited to availability of District resources to 

implement and enforce the measures, cost-effectiveness of the measure, potential adverse 

environmental impacts, potential economic impacts, effectiveness of emissions reductions, and 

availability of methods to quantify emissions reductions.‖ South Coast 2007 AQMP, page 9-1. 

The contingency measures do not meet the requirements of the CAA, namely the requirements 

for these contingency measures to be fully adopted or otherwise ready for quick implementation, 

for trigger mechanisms and an implementation schedule, and the AQMP does not provide for 

quantification of emissions reductions demonstrating the equivalent of one year of RFP for any 

of the suggested contingency measures.

CTY-01 - Offsetting potential emissions increase due to change in natural gas specifications 

This proposed contingency measure requires RECLAIM facilities that use natural gas of a 

quality that creates more emissions to offset these emissions for all pollutants. The measure is 

listed as a ―Remaining 2003 AQMP Revision Control Measure‖ and thus was relied on in the 

2003 AQMP for attainment. In addition, the reductions are not quantified, and may be zero, since 

the proposed measure may only reduce future emissions increases rather than provide net 

reductions. There is no trigger mechanism, and the AQMP does not quantify the reductions 
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associated with this measure. For these reasons, this proposed measure does not meet CAA 

requirements for contingency measures.

CTY – 02 – Clean Air Act Emission Fees for Major Stationary Sources – This proposed 

contingency measure would use fees generated from the District‘s CAA section 185 program for 

8-hour ozone, to achieve emissions reductions. See South Coast 2007 AQMP, p. 9-2. The funds 

collected through this rule would be used to implement other pollution control programs and 

reductions from these control programs would serve as contingency measures. The 

implementation of a section 185 program is triggered by a failure of the South Coast to attain the 

8-hour standard by 2024 and not by any failure to make RFP or to attain the PM2.5 NAAQS, a 

minimum requirement for contingency measures for PM2.5 SIPs. There is no implementation 

schedule provided, and the AQMP does not quantify the reductions associated with this measure. 

For these reasons, this proposed measure does not meet CAA requirements for contingency 

measures.

CTY-03 - Banning pre-Tier 3 off road diesel engines on High Pollution Advisory (HPA) days –

This proposed contingency measure would complement a CARB rule which proposed to 

establish declining fleet average emissions levels for off-road equipment over 25 horsepower 

(hp). The District proposed a complementary measure, SC-OFFRD-1, which would ban the use 

of pre-Tier 3 off-road diesel engines after 2023 on HPA days should the South Coast Air Basin 

fail to meet the 8-hour ozone standard. This proposed contingency measure would require 

additional rulemaking at the District level, as it is not currently adopted. It also would be 

implemented too late in time to provide for RFP or contingency reductions for PM2.5 RFP or 

attainment. In addition, the AQMP does not quantify the reductions associated with this measure. 

For these reasons, this proposed measure does not meet CAA requirements for contingency 

measures. 

CTY-04 - Accelerated implementation of CARB‘s mobile source measures – This proposed 

contingency measure, which could function as both an RFP and an attainment contingency 

measure, requires the District‘s Board to request that CARB accelerate the adoption and/or 

implementation of the remaining control measures that have not been adopted or fully 

implemented by one year. South Coast 2007 AQMP, page 9-3. Under CAA section 172(c)(9) 

and EPA‘s long-standing policies interpreting this section, contingency measures must require 

minimal additional rulemaking by the State and take effect within a few months of a failure to 

make RFP or to attain. This proposed contingency measure would require additional rulemaking 

at the District level and potentially substantial and lengthy additional rulemaking at the State 

level to be implemented. There is no trigger mechanism or implementation schedule provided, 

and the AQMP does not quantify the reductions associated with this measure For these reasons, 

this proposed measure does not meet CAA requirements for contingency measures.

Post-2014 Emissions Reductions. Excess reductions in 2015/2016 from CARB mobile source 

measures do not fully address the contingency measure requirement for the PM2.5 attainment 

year. The 2011 Progress Report includes the estimated incremental emissions reduction that will 

occur in 2015 from CARB‘s mobile source program, including the reductions expected from its 

In-use Truck and Bus Rule and In-use Off-road Engine Rules. See CARB Progress Report 

Supplement, Attachment 2. The updated 2015 reductions are 24 tpd NOx and 13 tpd VOC. 
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From information in the Plan, in Table I-1 we calculated one year‘s worth of RFP to be 1.1 tpd 

PM2.5, 52.8 tpd NOx, 30.8 tpd of VOC, and 2.8 tpd SO2. See TSD, section II.H, and CARB Staff 

Report on the 2007 South Coast AQMP, Appendix A. However, CARB‘s mobile source 

measures do not provide sufficient NOx reductions to meet one year‘s worth of RFP; therefore, 

post-attainment-year emissions reductions cannot be used to meet the CAA contingency measure 

requirement.

3. Proposed Actions on the Contingency Measures

In November 2010, we proposed to disapprove the RFP and attainment contingency 

measures in the South 2007 AQMP. We found that although the AQMP included suggestions for 

several contingency measures, they did not meet the CAA‘s minimum requirements for 

contingency measures (e.g., no additional rulemaking, surplus to attainment and RFP needs), the 

AQMP did not provide sufficient information to determine if the emissions reductions from the 

contingency measures are SIP creditable or to quantify the expected emissions reductions. We 

therefore were unable to determine if the suggested contingency measures provided reductions 

roughly equivalent to one year‘s worth of RFP. See 75 FR 71294 at71311-71312, and section II. 

J of the November 2010 TSD.

In our July 2011 amended proposal, we again proposed to disapprove the RFP and 

attainment contingency measures in the South 2007 AQMP. We found that although the AQMP 

included suggestions for several contingency measures, they did not meet the CAA‘s minimum 

requirements for contingency measures (e.g., no additional rulemaking, surplus to attainment and 

RFP needs), and the AQMP did not provide sufficient information to determine if the emissions 

reductions from the contingency measures are SIP creditable or to quantify the expected 

emissions reductions. We therefore were unable to determine if the suggested contingency 

measures provided reductions roughly equivalent to one year‘s worth of RFP. In CARB‘s 2011 

Progress Report, the State included calculations for the reductions associated with existing 

CARB mobile source control programs for 24 tpd of NOx and 13 tpd of VOC in the year after 

attainment. However, these measures do not provide sufficient reductions to meet one year‘s 

worth of RFP, based on the information provided in the 2011 Progress Report (see 2011 Progress 

Report, Appendix C, page 2, and CARB Progress Report Supplement, Attachment 2). Therefore, 

post-attainment year emissions reductions do not meet the CAA contingency measure 

requirement. See 76 FR 41562 at 41479-41580, and section II.I of the July 2011 TSD.

4. Evaluation and Conclusions

Under the PM2.5 implementation rule, a state must submit contingency measures that 

meet the requirements of CAA section 172(c)(9) and provide for the equivalent of roughly one

year‘s worth of RFP. One year‘s worth of RFP is determined by dividing the emissions

reductions from base year levels that are needed for attainment by the number of years between 

the base year (2002) and the attainment year (2014). 72 FR 20586 at 20643. We show this 

calculation for the South Coast 2007 AQMP in Table I-1 below.
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We are not evaluating the provisions of the updated South Coast 2007 AQMP that 

address contingency measures for failure to meet the 2009 RFP benchmarks. Information 

available to EPA and the public shows that the South Coats met its 2009 RFP benchmarks for 

2009 for directly-emitted PM2.5, NOx, and VOC. SOx emissions are higher than the linear 

benchmark but catch up to the benchmark in 2012 due to recently adopted rules controlling 

emissions of SOx. See 2011 Progress Report, Table C-2 and section II.H of this TSD. As a 

result, contingency measures for failure to meet the 2009 RFP benchmark no longer have 

meaning or effect under the CAA and therefore do not require any review or action by EPA. In 

addition, as noted above, the purpose of RFP contingency measures is to provide continued 

progress while the SIP is being revised to meet a missed RFP milestone. Failure to meet the 2009 

benchmark would have required California to revise the South Coast 2007 AQMP to assure that 

the next milestone was met and that the plan still provided for attainment. California has, in fact, 

prepared and submitted a revision to the South Coast 2007 AQMP that provides for RFP in 2012 

and for attainment by 2015. 

Under the PM2. 5 implementation rule, a State must submit contingency measures that 

meet the requirements of section 172(c)(9) and provide for the equivalent of roughly one year‘s 

worth of RFP. One year‘s worth of RFP is determined by the emissions reductions from the base 

year baseline inventory (the base year is 2002 for the South Coast 2007 AQMP) divided by the 

number of years between the base year and the attainment year (2014). 72 FR 20586 at 20643. 

These calculations were given in Table H-2 for directly emitted PM2.5 and for the attainment 

plan precursors NOx, VOC, and SOx. 

Table I-1

Reductions Needed from Contingency Measures 

(tons per average annual day)

NOx VOC PM2.5 SOx

A 2002 baseline 1093 844 99 53

B 2014 attainment 460 474 86 20

C Emissions reductions needed for 

attainment (A-B) 633 370 13 33

D One year‘s RFP (C/12) 52.8 30.8 1.1 2.8

E One year‘s RFP as percent of 

2002 baseline 4.8% 3.6% 5.2% 1.9%

Source: Table 6-3A of South Coast 2007 AQMP and EPA staff calculations.

Table I-2 summarizes reductions needed to meet 1 year‘s worth of RFP based on the 

updated emissions estimates in the 2011 Progress Report. These new calculations do not change 

our conclusion that the contingency measures in the revised 2007 AQMP are insufficient to meet 

CAA requirements. Table I-3 summarizes the approvability issues related to the contingency 

measures in the revised South Coast 2007 AQMP. Table I-4 provides CARB‘s post-attainment 

year reductions for attainment contingency measures from the 2011 Progress Report.
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Table I-2

Reductions Needed from Contingency Measures to Equal One Year‘s Worth of RFP based on 

2011 Progress Report

(tons per average annual day)

NOx VOC PM2.5 SOx

A 2002 baseline 1046 827 94 65

B 2014 attainment 460 474 86 20

C Emissions reductions needed for 

attainment (A-B) 586 353 8 45

D One year‘s RFP (C/12) 48.8 29 0.7 3.8

E One year‘s RFP as percent of 

2002 baseline 4.7% 3.5% 0.7% 5.7%

Source: 2011 Progress Report, CARB Supplement, and EPA staff calculations.

We received several comments on our proposed disapproval of the contingency 

measures. We have reviewed these comments and provided responses to them. See section III of 

this TSD. No issues raised in these comments changed our finding that the contingency measures 

in the South Coast 2007 AQMP and revised 2007 State Strategy are insufficient to meet the 

applicable requirements of the CAA and EPA guidance.
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Table I-3

Summary of Approvability of Contingency Measures from the South Coast 2007 AQMP

Measure

RFP or 

Attainment 

Contingency 

Measure?

Approvable 

as a 

Contingenc

y Measure?

Comment

Quantified Reductions 

(Tons per Average Annual Day)

NOx VOC Direct 

PM2.5 

SOx

Offsetting potential 

emissions increase due 

to change in natural 

gas specifications 

Attainment No

Not triggered by failure to 

make RFP or attain; 

reductions associated with 

this measure may only 

offset potential increases

and not provide net 

reductions; reductions not 

quantified; control measure 

in 2003 AQMP.

Not quantified

Ozone Nonattainment 

Area Fee

2012 RFP 

milestone/

Attainment

No

Not triggered by failure to 

make RFP or attain for the 

PM2.5 standard; reductions 

not quantified;.

Not quantified

Banning pre-Tier 3 off 

road diesel engines on 

High Pollution 

Advisory (HPA) days

Attainment No

Does not trigger until 2023; 

would require additional 

rulemaking; reductions not 

quantified;.

Request CARB to 

expedite 

implementation of 

mobile source controls

Both No

Would require additional 

rulemaking at District and 

State level; reductions not 

quantified;.

Not quantified

Post-Attainment year 

emissions reductions RFP No

Insufficient excess 

reductions in RFP 

demonstration to meet 1 

year of required reductions

for all pollutants.

quantified in 2011 Progress Report as 24 tpd of NOx 

and 13 tpd of VOC
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Table I-4

Summary of Reductions from Contingency Measures

(tons per average annual day)

Direct PM2.5 NOx VOC SOx

2012 RFP contingency reductions 0 0 0 0

Attainment contingency reductions 0 24 13 0

1-year‘s worth of RFP 1.1 52.8 30.8 2.8

Based on this evaluation and for the reasons stated above, we are disapproving the 

contingency measure provisions for the 2012 RFP year and the attainment year in the South 

Coast 2007 AQMP for PM2.5 as not meeting the requirements of CAA section 172(c)(9) and 40 

CFR 51. 1012. 

EPA is committed to working with the District, CARB and SCAG to resolve the 

remaining issues with the SIP that make the current PM2.5 attainment SIP for the South Coast 

nonattainment area not fully approvable under the CAA and the PM2.5 implementation rule. 

However, because we are finalizing the disapproval of the contingency measure provisions in the 

South Coast 2007 AQMP, the offset sanction in CAA section 179(b)(2) will apply in the South 

Coast PM2.5 nonattainment area 18 months after the effective date of today‘s final disapproval. 

The highway funding sanctions in CAA section 179(b)(1) will apply in the area six months after 

the offset sanction is imposed. Neither sanction will be imposed under the CAA if California 

submits and we approve prior to the implementation of sanctions, SIP revisions that correct the 

deficiencies identified in our action. In addition to the sanctions, CAA section 110(c)(1) provides 

that EPA must promulgate a federal implementation plan addressing the deficient elements in the 

PM2.5 SIP for the South Coast nonattainment area two years after the effective date of any 

disapproval, should we not approve a SIP revision correcting the deficiencies within the two 

years.

Because we are approving the RFP and attainment demonstrations and the motor vehicle 

emission budgets, we are issuing a protective finding under 40 CFR § 93.120(a)(3) to the 

disapproval of the contingency measures. Without a protective finding, final disapproval would 

result in a conformity freeze under which only projects in the first four years of the most recent 

conforming RTP and TIP can proceed. During a freeze, no new RTPs, TIPs or RTP/TIP 

amendments can be found to conform. See 40 CFR § 93.120(a)(2). Under a protective finding, 

however, final disapproval of the contingency measures will not result in a transportation 

conformity freeze in the South Coast PM2.5 nonattainment area.
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J. Adequacy of the Motor Vehicle Emissions Budgets in the Revised South Coast 2007 

AQMP 

1. Requirements for Motor Vehicle Emissions Budgets

CAA section 176(c) requires Federal actions in nonattainment and maintenance areas to 

conform to the SIP‘s goals of eliminating or reducing the severity and number of violations of 

the NAAQS and achieving expeditious attainment of the standards. Conformity to the SIP‘s 

goals means that such actions will not: (1) cause or contribute to violations of a NAAQS, (2) 

worsen the severity of an existing violation, or (3) delay timely attainment of any NAAQS or any 

interim milestone.

Actions involving Federal Highway Administration (FHWA) or Federal Transit 

Administration (FTA) funding or approval are subject to the EPA‘s transportation conformity 

rule, codified at 40 CFR part 93, subpart A. Under this rule, metropolitan planning organizations 

(MPOs) in nonattainment and maintenance areas coordinate with state and local air quality and 

transportation agencies, EPA, FHWA, and FTA to demonstrate that an area‘s regional 

transportation plans (RTP) and transportation improvement programs (TIP) conform to the 

applicable SIP. This demonstration is typically done by showing that estimated emissions from 

existing and planned highway and transit systems are less than or equal to the motor vehicle 

emissions budgets (budgets) contained in all control strategy SIPs. An attainment, maintenance, 

or RFP SIP should include budgets for the attainment year, each required RFP year or last year 

of the maintenance plan, as appropriate. Budgets are generally established for specific years and 

specific pollutants or precursors.

PM2.5 attainment and RFP plans should identify budgets for direct PM2.5 and PM2.5

attainment plan precursors. All direct PM2.5 SIP budgets should include direct PM2.5 motor 

vehicle emissions from tailpipe, brake wear, and tire wear. A state must also consider whether reentrained paved and unpaved road dust or highway and transit construction dust are significant 

contributors and should be included in the direct PM2.5 budget. See 40 CFR § 93.102(b) and

§ 93.122(f) and the conformity rule preamble at 69 FR 40004, 40031–40036 (July 1, 2004). 

MPOs may use budgets in a submitted SIP but not-yet approved SIP only if EPA has first 

determined that the budgets are adequate. To be found adequate and to be eventually approved, 

the submittal must meet the conformity adequacy requirements of 40 CFR § 93.118(e)(4) and be 

approvable under all pertinent SIP requirements. In addition, the budgets must reflect all of the 

motor vehicle control measures contained in the attainment and RFP demonstrations. See 

40 CFR § 93.118(e)(4)(v).
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2. Motor Vehicle Emissions Budgets in the South Coast 2007 AQMP

a. Budgets Submitted in South Coast 2007 AQMP (submitted November 2007)

As submitted on November 28, 2007, the 2007 South Coast AQMP included a set of 

PM2.5 budgets for RFP years 2009 and 2012, the attainment year 2014, and 2023 and 2030 for 

directly emitted PM2.5, VOC, and NOx. See CARB Resolution 07-05, which revised the budgets 

in the 2007 South Coast AQMP as adopted by the SCAQMD, and which was included in the 

November 28, 2007 submittal. We refer to these budgets as the ―original‖ budgets. The directlyemitted PM2.5 budgets included tailpipe, brake wear, and tire wear emissions and also included 

paved road, unpaved road, and road construction dust because these were considered to be 

significant contributors to PM2.5 levels in the South Coast. No budgets for SOx were included 

because on-road emissions of SOx were considered insignificant. Additionally, the submittal did 

not include any budgets for ammonia because the submitted SIP does not specify ammonia as a 

significant contributor to the area‘s PM2.5 problem.

b. Budgets Submitted in Revised South Coast 2007 AQMP (submitted April 2008)

On April 30, 2008, CARB submitted a SIP revision that replaces the original set of PM2.5

budgets with two new sets of budgets (―replacement‖ budgets). One set of the replacement 

budgets is referred to as ―SIP-based‖ budgets, and the other set is referred to as ―baseline‖ 

budgets. In its April 30, 2008 submittal, CARB requests that EPA give primary consideration to 

the ―SIP-based‖ budgets and only find the ―baseline‖ budgets to be adequate if EPA cannot find 

the ―SIP-based‖ budgets adequate in their entirety.

The replacement budgets submitted on April 30, 2008 differed from the original budgets 

in that they reflected the EPA-approved EMFAC2007 motor vehicle emission factor model (see 

73 FR 3464, January 18, 2008) rather than the District‘s CEPA emission factor model, which had 

been used for the original budgets. The ―SIP-based‖ budgets reflect emissions reductions from 

rules adopted by October 2006 and also from control measures CARB expects to adopt in 

regulatory form in the future. The ―baseline‖ budgets differed from the ―SIP-based‖ budgets by 

excluding emission reductions from control measures in the 2007 State Strategy that had not 

been adopted in regulatory form by October 2006.81 Moreover, the ―baseline‖ budgets were only 

established for RFP years 2009 and 2012 whereas the ―SIP-based‖ budgets were established for 

the RFP years, the attainment year, and 2023 and 2030..

c. Budgets Submitted in 2011Progress Report (submitted May 2011)

CARB submitted updated budgets for the South Coast in its 2011 Progress Report. See 

2011 Progress Report, Appendices D and A, respectively. Additional information associated with 

the motor vehicle emission budget calculations were provided in Attachment 4 of the CARB 

 

81With respect to the ―SIP-based‖ budget for RFP year 2009, however, CARB did exclude the 

emissions reductions from measures not adopted by October 2006. Thus, the ―SIP-based‖ PM2.5

budget for 2009 is the same as the ―baseline‖ PM2.5 budget for that year. 
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2011 Progress Report Supplement.82 Documentation of how these budgets were calculated is 

provided in Appendix A of the Progress Report and Attachment 4 of the May 18th letter. 

This submittal also includes a trading mechanism that would allow the substitution of 

excess NOx reductions for any on-road increases in directly-emitted PM2.5 emissions using a 

ratio of 10 tpd NOx to 1 tpd of PM2.5. Transportation conformity trading mechanisms are 

allowed under 40 CFR § 93.124. The basis for the trading mechanism is the SIP attainment 

modeling which established the relative contribution of each PM2.5 precursor pollutant. This 

trading mechanism would only be used, if needed, for conformity analyses for years after 2014. 

To ensure that the trading mechanism does not impact the ability to meet the NOx budget, the 

NOx emissions reductions available to supplement the PM2.5 budget would only be those 

remaining after the NOx budget has been met. See 2011 Progress Report, Appendix D, notes to 

Table D-1.

d. Revision to Budgets Submitted by CARB (July 2011)

On June 3, 2011, we received a letter from CARB indicating that they would revise the 

budgets to remove emission reductions from the AB 923 High Emitter Program and make minor 

adjustments to correct a spreadsheet error.83 The letter was in response to EPA‘s request to 

remove the reductions since EPA has not yet reviewed the program and approved it for SIP 

credit and since the program was not credited in the South Coast attainment or RFP 

demonstrations. The letter from CARB stated that they intend to revise the budgets in the 2011 

Progress Report by recalculating the budgets without reductions from the AB923 program. 

On June 20, 2011, CARB posted on its website technical revisions to the updated MVEB 

in the 2011 Progress Report that were referenced in a June 3rd letter to EPA.84 See CARB, 

―Proposed 8-Hour Ozone State Implementation Plan Revisions and Technical Revisions to the 

PM2.5 State Implementation Plan Transportation Conformity Budgets for the South Coast and 

San Joaquin Valley Air Basins,‖ Appendix C, June 20, 2011, posted at 

www.arb.ca.gov/planning/sip/2007sip/2007sip.htm. These revised updated budgets are shown in 

Table J-1 below. The technical revisions corrected data entry errors in the budget calculations 

and removed the emission reductions attributed to AB923 (the South Coast District‘s light and 

medium duty high emitter program). 

CARB adopted the 8-Hour Ozone State Implementation Plan Revisions and Technical 

Revisions to the PM2.5 State Implementation Plan Transportation Conformity Budgets for the 

South Coast and San Joaquin Valley Air Basins, June 20, 2011, with Appendices on July 21, 

2011 and submitted this SIP revision to EPA on July 29, 2011. 

 

82 See Letter from Lynn Terry, Deputy Executive Officer, CARB, to Elizabeth Adams, Deputy Director, EPA 

Region 9, dated May 18, 2011

83 See letter, James M. Goldstene, Executive Officer, CARB, to Deborah Jordan, Air Division Director, EPA Region 

9, ―RE: Changes to Motor Vehicle Emission Budgets in 2011 Progress Plan,‖ dated June 3, 2011.

84 See letter, James M. Goldstene, Executive Officer, CARB, to Deborah Jordan, Air Division Director, EPA Region 

9, June 3, 2011
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Table J-1 Calculation of the Updated PM2.5 and PM2.5 Precursor Budgets 

for the South Coast PM2.5 Nonattainment Area (tons per annual average day)

South Coast Air 

Basin

2012 2014

VOC NOx PM2.5 VOC NOx PM2.5

Baseline Inventory 162.6 350.8 17.5 146.1 305.7 17.2

Re-entrained Road 

Dust (Paved)

18.8

19.0

Re-entrained Road 

Dust (Unpaved)

1.0 1.0

Road Construction 

Dust 0.2 0.2

State Strategy 

Adjustments -8.7 -23.7 -1.4 -13.6 -15.1 -2.8

Adjustments to 

Baseline -0.4 -1.4 -0.1 -0.6 -1.4 -0.2

Budgets 154 326 37 132 290 35

Note: Budgets are rounded up to the nearest ton

Table J-1 shows how the updated budgets were calculated. The calculation begins with 

the initial SIP on-road mobile source inventory as submitted in Appendix III of the South Coast 

2007 AQMP. Two adjustments are made to the inventory to derive the final budget. The first 

adjustment, shown as the ―State Strategy Adjustment‖ in Table J-1, incorporates the impacts of 

both the recession and the Truck and Bus regulations as amended in December 2010. It also 

includes adjustments for CARB‘s adopted regulations for solid waste collection and public 

vehicle fleets, heavy-duty chip reflash, heavy duty truck idling, smog check improvements, and 

reformulated gasoline. The second adjustment, shown as ―Adjustments to Baseline‖ in Table J-1, 

consists of reductions from AB 1493 (Pavley) and benefits from the on-road portion of the Carl 

Moyer program. The updated budgets as revised in June 2011 are listed in Table J-2.

Table J-2. Summary of Updated PM2.5 and PM2.5 Precursor Budgets for the South 

Coast PM2.5 Nonattainment Area (tons per annual average day)

2012 2014

VOC NOx

Directly 

emitted

PM2.5

VOC NOx

Directly 

emitted

PM2.5

South Coast Air 

Basin

154 326 37 132 290 35

Source: ―Proposed 8-Hour Ozone State Implementation Plan Revisions and Technical Revisions to the PM2.5 State 

Implementation Plan Transportation Conformity Budgets for the South Coast and San Joaquin Valley Air Basins,‖ 

Appendix C, June 20, 2011, posted at www.arb.ca.gov/planning/sip/2007sip/2007sip.htm.
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3. Prior Proposed Actions and Current Final Action on the Budgets

a. EPA’s May 6, 2008 Adequacy/Inadequacy Finding on the Motor Vehicle Emissions Budgets

On May 6, 2008, we notified CARB that we had found the ―SIP-based‖ PM2.5 budgets for 

the 2007 South Coast AQMP, as submitted on April 30, 2008, did not meet certain adequacy 

requirements under 40 CFR 93.118(e)(4) and (5) and concluded that they were inadequate for 

transportation conformity purposes. See letter and enclosures, dated May 6, 2008 from Deborah 

Jordan, Director, Air Division, EPA Region IX, to James Goldstene, Executive Officer, CARB, a 

copy of which has been placed in the docket for this rulemaking. However, in our May 2008 

adequacy determination, we found the ―baseline‖ PM2.5 budgets for the RFP years 2009 and 2012 

to be adequate. Generally, we found the ―SIP-based‖ budgets to be inadequate because they 

reflected control measures not yet adopted in regulatory form and thus not adequately quantified 

or supported by the plan. In contrast, we found the ―baseline‖ PM2.5 budgets to be consistent with 

the plan‘s RFP demonstration and to be based on adopted mobile source regulations that have 

already been implemented. Our notice of adequacy/inadequacy was published on May 15, 2008 

at 73 FR 28110 (corrected on June 18, 2008 at 73 FR 34837) and was effective on May 30, 2008. 

The finding is available on EPA‘s transportation conformity website at 

http://www.epa.gov/otaq/stateresources/transconf/pastsips.htm.

b. EPA’s November 22, 2010 Proposed Action on the Motor Vehicle Emissions Budgets

As explained in the May 15, 2008 Federal Register notice, an adequacy review is separate 

from EPA‘s completeness and full plan review, and should not be used to prejudge EPA‘s 

ultimate approval action for the SIP. Even if we find a budget adequate, the SIP and the 

associated budget could later be disapproved. 

When we had completed a thorough review of the entire South Coast 2007 AQMP for 

CAA and EPA regulations for PM2. nonattainment area SIPs, which was described in our 

November 2010 technical support document and in our proposed action, we concluded that the 

―SIP-based‖ budgets were not precisely quantified because the new emission reductions did not 

result from adequately specified control measures, and that the plan as a whole would not ensure 

RFP and attainment of the PM2.5 NAAQS and did not show a clear relationship between the 

―SIP-based‖ budgets and the emissions inventory and control measures. We also determined that 

we had to propose to disapprove the RFP demonstration in the South Coast 2007 AQMP, and 

therefore could not propose to approve the RFP budgets. Specifically the budgets, when 

considered together with all other emissions sources, were inconsistent with the applicable 

requirements for reasonable further progress and attainment.

Thus, in November 2010 we proposed to disapprove both the ―baseline‖ and the ―SIPbased‖ PM2.5 budgets for transportation conformity purposes. SCAG and the U.S. Department of 

Transportation were not using the ―SIP-based‖ budgets in transportation conformity 

determinations due the inadequacy finding made in 2008. If the proposed disapproval of the 
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budgets had been finalized, then neither the ―baseline‖ or ―SIP-based‖ budgets could be used in 

transportation conformity determinations after the effective date of the disapproval.85

In summary, for the reasons discussed above, in November 2010 we proposed 

disapproval of the ―SIP-based‖ PM2.5 budgets that we previously had determined to be 

inadequate. Because we were proposing to disapprove the RFP demonstration, we also proposed 

to disapprove as well the ―baseline‖ PM2.5 budgets for RFP years 2009 and 2012 that we had 

previously determined to be adequate. 

c. Proposed Action on the Revised Budgets (July 2011)

As discussed in sections II.G. and II.H, in our July 2011 amended proposal, we proposed 

to approve the attainment and RFP demonstrations in the South Coast 2007 AQMP. As indicated 

above, at the time of our July amended proposal, we had received a letter from CARB indicating 

that they would revise the budgets to remove emission reductions from the AB 923 program and 

correct a minor calculation error.86 EPA could not determine adequate or approve the budgets 

included in the 2011 Progress Report since we cannot approve SIP credit for the AB 923 

program. Our approval was contingent upon our receipt of a complete SIP submittal containing 

the revised budgets. On June 20, 2011, CARB posted on its website technical revisions to the 

updated MVEB in the 2011 Progress Report that were referenced in a June 3rd letter to EPA. See 

CARB, ―Proposed 8-Hour Ozone State Implementation Plan Revisions and Technical Revisions 

to the PM2.5 State Implementation Plan Transportation Conformity Budgets for the South Coast 

and San Joaquin Valley Air Basins,‖ Appendix C, June 20, 2011, posted at 

www.arb.ca.gov/planning/sip/2007sip/2007sip.htm. These revised updated budgets are shown in 

Table J-2 above. 

d. Final Action on the Revised Updated Budgets 

EPA is not separately making an adequacy finding on the revised updated budgets in the 

2011 Progress Report but is reviewing the budgets against our adequacy criteria in 

40 CFR § 93.318(a)(4) as part of its review of the approvability of the budgets. The results of our 

adequacy review are shown in the Table J-3 below. EPA is not required under its Transportation 

Conformity rule to find budgets adequate prior to approving of them.

As discussed in sections II.G. and II.H, in our July 2011 amended proposal, we proposed 

to approve the attainment and RFP demonstrations in the South Coast 2007 AQMP. As indicated 

above, at the time of our July amended proposal, we had received a letter from CARB indicating 

that they would revise the budgets to remove emission reductions from the AB 923 program and 

 

85 Note that the RFP budgets that EPA found adequate on May 6, 2008 remain adequate for transportation 

conformity purposes unless and until a final action disapproving them becomes effective, or the State submits, and 

EPA finds adequate and/or approves, replacement budgets. 

86 See letter, James M. Goldstene, Executive Officer, CARB, to Deborah Jordan, Air Division Director, EPA Region 

9, June 3, 2011
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correct a minor calculation error.87 On June 20, 2011, CARB posted on its website technical 

revisions to the updated MVEB in the 2011 Progress Report that were referenced in a June 3rd

letter to EPA. See CARB, ―Proposed 8-Hour Ozone State Implementation Plan Revisions and 

Technical Revisions to the PM2.5 State Implementation Plan Transportation Conformity Budgets 

for the South Coast and San Joaquin Valley Air Basins,‖ Appendix C, June 20, 2011, posted at 

www.arb.ca.gov/planning/sip/2007sip/2007sip.htm. These revised updated budgets are shown in 

Table J-2 above. EPA could not determine adequate or approve the budgets included in the 2011 

Progress Report since we cannot approve SIP credit for the AB 923 program. 

We received a SIP revision from CARB on July 29, 2011 with the 8-Hour Ozone State 

Implementation Plan Revisions and Technical Revisions to the PM2.5 State Implementation Plan 

Transportation Conformity Budgets for the South Coast and San Joaquin Valley Air Basins, June 

20, 2011, with Appendices that the CARB Board had adopted on July 21, 2011. 

These revised updated budgets are now consistent with the RFP and attainment 

demonstrations in the South Coast 2007 AQMP for PM2.5 and meet all other applicable statutory 

and regulatory requirements. We posted these budgets on our adequacy website for public 

comment on July 14, 2011 for a 30-day comment period which ended on August 15, 2011 (see 

http://www.epa.gov/otaq/stateresources/transconf/currsips.htm). We received no comments on 

our adequacy posting, and have completed our adequacy review on these budgets.

EPA, therefore, finds the revised updated budgets that CARB submitted on July 29, 2011 

to be consistent with the approvable RFP and attainment demonstrations and to find that they 

meet all other applicable statutory and regulatory requirements including the adequacy criteria in 

40 CFR § 93.118(e)(4). Therefore, EPA is approving the revised updated budgets because we 

have received the revised budgets as a complete SIP revision from the State prior to our final 

action on the South Coast 2007 AQMP.

Now that the approval of the budgets is finalized, SCAG and the U.S. Department of 

Transportation are required to use the revised budgets in transportation conformity 

determinations. Due to the formatting of the budgets (combining emission changes, recession 

impacts and reductions from control measures) CARB will need to provide SCAG with emission 

reductions associated with the control measures incorporated into the budgets for the appropriate 

analysis years in future conformity determinations so that they can include these reductions per 

40 CFR § 93.122. In addition, for these conformity determinations, the motor vehicle emissions 

from implementation of the transportation plan should be projected and compared to the budgets

at the same level of accuracy as the budgets in the plan, for example emissions should be 

rounded to the whole number (e.g. 11 tpd). 

 

87 See letter, James M. Goldstene, Executive Officer, CARB, to Deborah Jordan, Air Division Director, EPA Region 

9, June 3, 2011
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4. Action on Trading Mechanism

The 2011 Progress Report also includes a proposed trading mechanism for transportation 

conformity analyses that would allow future decreases in NOx emissions from on-road mobile 

sources to offset any on-road increases in PM2.5, using a NOx:PM2.5 ratio of 10:1. Transportation 

conformity trading mechanisms are allowed under 40 CFR § 93.124. The basis for the trading 

mechanism is the SIP attainment modeling which established the relative contribution of each 

PM2.5 precursor pollutant.

EPA has reviewed the 10:1 NOx:PM2.5 ratio and has found it appropriate ratio for trading 

between NOx and direct PM2.5 for transportation conformity purpose in the South Coast Air 

Basin for the 1997 PM2.5 NAAQS. The method for determining the NOx equivalent factors is 

documented in CARB's 2011 Progress Report, Appendix C: PM2.5 Reasonable Further Progress 

Calculations. The PM2.5 attainment CMAQ modeling simulation was conducted using projected 

emission reductions for control measure implementation for 2014. The output of the simulation 

was averaged by component species for the eight validation sites that represent the Basin. This

method is adequate for purposes of assessing the effect of area-wide emissions changes, such as 

are used in conformity budgets. See July 2011 TSD. The normalized NOx-equivalent 

conversion factors were calculated for PM2.5, SOx and ROG. The NOx equivalent factor for

PM2.5 was approximately 9.9; and the factor for SOx was 15, and the factor for ROG was 0.4. 

As noted above, CARB included a trading mechanism to be used in transportation 

conformity analyses that use the proposed budgets as is allowed under 40 CFR § 93.124. This 

trading mechanism would allow future decreases in NOx emissions from on-road mobile sources 

to offset any on-road increases in PM2.5, using a NOx:PM2.5 ratio of 10:1. To ensure that the 

trading mechanism does not impact the ability of SCAG to meet the NOx budget, the NOx

emission reductions available to supplement the PM2.5 budget would only be those remaining 

after the 2014 NOx budget has been met. The trading mechanism will be implemented with the 

following criteria. The trading applies only to:

Analysis years after the 2014 attainment year.

On-road mobile emission sources.

Trades using vehicle NOX emission reductions in excess of those needed to meet 

the NOX budget.

Trades in one direction from NOX to direct PM2.5.

A trading ratio of 10 tpd NOX to 1 tpd PM2.5.

Clear documentation of the calculations used in the trading would be included in the conformity 

analysis.

EPA is approving the use of this NOx to PM2.5 interpollutant trading ratio in 

transportation conformity determinations for the 1997 PM2.5 standards in the South Coast 

nonattainment area. EPA is also approving the use of this ratio in transportation conformity 

determinations for the 2006 PM2.5 NAAQS, but only until such time as EPA finds adequate or 

approves budgets developed specifically for the 2006 standard. EPA is not approving, at this 
TSD for the Final Rulemaking

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EPA- Region 9 Page 139

time, the use of this ratio in plans for future PM standards or in the District‘s new source review 

(NSR) permitting program.

EPA believes the 2011 Progress Report includes an approvable trading mechanism for 

determining transportation conformity after 2014. EPA is approving the trading mechanism and 

all the criteria included in the footnote to Table D-1 of Appendix D in the 2011 Progress Report 

as enforceable components of the transportation conformity program for the South Coast PM2.5

nonattainment area.
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments
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EPA- Region 9 Page 141

Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(i)

The plan was endorsed by the 

Governor (or designee) and was 

subject to a public hearing.

Both the SCAQMD and CARB have satisfied applicable statutory and 

regulatory requirements for reasonable public notice and hearing prior to 

adoption and submittal of the South Coast 2007 AQMP and the 2007 State 

Strategy. The District conducted public workshops, provided public comment 

periods, and held a public hearing prior to the adoption of the Plan on June 1, 

2007. Documentation accompanying the AQMP describes a public and agency 

outreach effort. See, e.g., the SCAQMD‘s Response to Comments on the Draft

2007 Air Quality Management Plan (February 2007), submitted by CARB on 

November 28, 2007 as enclosure I-E, describing nine regional workshops held 

from October 24 through December 6, 2006 to discuss the draft 2007 Air 

Quality Management Plan (AQMP) released on October 10, 2006. The 

sequence of public meetings held to discuss the elements of the draft State 

Strategy for California‘s 2007 SIP (State Strategy) is described in the CARB 

staff report developed for the CARB Board‘s consideration prior to adoption of 

the State Strategy. CARB also provide the required public notice and 

opportunity for public comment prior to its September 27, 2007 public hearing 

on the South Coast 2007 AQMP. See CARB, Notice of Public Meeting to 

Consider Approval of the 2007 Air Quality Management Plan for Attaining the 

Federal 8-hour Ozone and PM2.5 Standards in the South Coast Air Basin and 

the Coachella Valley. See 

http://www.arb.ca.gov/board/ma/2007/ma092707.htm and

http://www.arb.ca.gov/regact/nonreg/scsip07.pdf.

CARB also conducted public workshops, provided public comment periods, 

and held a public hearing prior to its adoption of the 2007 State Strategy on 

September 27, 2007. CARB, Notice of Public Meeting to Consider Approval 

of the Proposed State Strategy for California‘s State Implementation Plan 
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(i)

(cont‘d)

CARB also provide the required public notice, opportunity for public 

comment, and public hearing prior to its April 24, 2009 adoption of revisions 

to the Strategy. See CARB, Notice of Public Hearing to Consider a Status 

Report on the State Strategy for California‘s 2007 State Implementation Plan 

and Consider Approval of a Proposed Revision to the State Implementation 

Plan Reflecting Implementation of the 2007 State Strategy, March 24, 2009. 

CARB also provided a public comment period and held a public

hearing prior to its adoption of the 2011 Progress Report on April 28, 2011. 

The SIP was made available for public review on March 29, 2011. See 

http://www.arb.ca.gov/planning/sip/planarea/2011_sip_revision_notice.pdf for 

the public hearing notice 

andhttp://www.arb.ca.gov/planning/sip/planarea/noticesworkshops.htm for the 

public hearing documentation.

Each of the four SIP submittals that comprise the South Coast PM2.5

attainment plan include proof of publication for notices of SCAQMD and 

CARB public hearings as evidence that all hearings were properly noticed.
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(ii)

The plan was developed through 

consultation with federal, state and 

local agencies; full implementation 

plan documentation was provided 

and EPA‘s stated concerns, if any, 

were addressed.

Y

Consultation with federal, state and local agencies was undertaken; this 

consultation took place with the SCAG interagency consultation working 

group Members of the consultation group include: EPA, FHWA, FTA, CARB, 

Caltrans, the South Coast Air Quality Management District (SCAQMD), and 

the area‘s Metropolitan Planning Organization (MPO), SCAG and county 

transportation agencies. EPA received a copy of the draft 2011 Progress 

Report, the South Coast 2007 AQMP and draft State Strategy but provided no 

written comments. However, in response to EPA‘s requests for additional 

information, CARB did provide Attachment A included in a May 18, 2011 

letter from Lynn Terry, Deputy Executive Officer, to Elizabeth Adams, Deputy 

Director, EPA Region 9. Furthermore, in response to EPA discussions, ARB 

also agreed to revise the MVEBs to remove AB923 credit, via a letter dated 

June 3, 2011 from Lynn Terry, Deputy Executive Officer, CARB, to Elizabeth 

Adams, Deputy Director, EPA Region 9. EPA concerns were addressed in the 

two letters. The revised budgets are posted at the following URL: 

http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm and were submitted 

to EPA on July 29, 2011 as part of the 8-Hour Ozone State Implementation 

Plan Revisions and Technical Revisions to the PM2.5 State Implementation 

Plan Transportation Conformity Budgets for the South Coast and San Joaquin 

Valley Air Basins, June 20, 2011, with Appendices.

Sec. 

93.118(e)(4)(iii)

The motor vehicle emission budgets 

are clearly identified and precisely 

quantified.

Y

The motor vehicle emissions budgets for 2012 and 2014 are clearly identified 

and precisely quantified in Appendix A (page A-5) of the 2011 Ozone SIP 

Revision. These budgets reflect control measures that were already adopted at 

the time the CARB adopted the 2011 Progress Report on April 28, 2011. 2011 

Progress Report, Appendix A, p. 3. CARB did not update the budget for 2009 

because the 2009 budgets are longer needed for any conformity determination 

in the South Coast nonattainment area. 2011 Ozone SIP Revision, Appendix 

A, p. A-5. 
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(iv)

The motor vehicle emissions 

budget(s), when considered together 

with all other emission sources, is 

consistent with applicable 

requirements for reasonable further 

progress and attainment.

Y

EPA has concluded that the budgets for the year 2012 when considered 

together with all other emission sources, are consistent with the requirement to 

demonstrate reasonable further progress for the 1997 annual and 24-hour PM2.5

standards. This finding is based on review of the revised RFP demonstrations 

in Appendix C (Table C-1) of the 2011 Progress Report. As documented in 

Section II.H. of this TSD, EPA is proposing to approve the revised RFP 

demonstration.

EPA has concluded that the budgets for the year 2014 when considered 

together with all other emission sources, are consistent with the requirement to 

demonstrate expeditious attainment of the 1997 annual and 24-hour PM2.5

standards. This finding is based on review of the revised attainment 

demonstrations in the 2011 Progress Report. As documented in Section II.G. 

of this TSD, EPA is proposing to approve the revised attainment 

demonstration.

The revised budgets for direct PM2.5 include emissionsfrom re-entrained road 

dust (paved and unpaved) and road/transit construction activities. See 2011 

Progress Report, Appendix A, Table A-1.The 2011 Progress Report does not 

include budgets for the PM2.5 precursor SOx because on-road vehicles are 

projected to be an insignificant contributor to PM2.5 levels in the South Coast 

in both 2012 and 2014. South Coast 2007 AQMP, p. 3-17. The 2011 Progress 

Report also does not include budgets for the PM2.5 precursor and ammonia 

because it is not considered an attainment PM2.5 precursor in the South Coast 

and thus is not required to be controlled for PM2.5 attainment. See South Coast 

2007 AQMP, pages 4-3 and 4-4 and section II.C of this TSD. CARB 

submitted revisions to the MVEBs removing the emission reductions 

associated with AB923 measures, on July 29, 2011 as part of the 2011 8-Hour 

Ozone SIP, the MVEBs are now consistent with the creditable RFP and 

attainment demonstrations 
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(v)

The plan shows a clear relationship 

among the emissions budget(s), 

control measures and the total 

emissions inventory.

Y

The emission inventories for all point, area, and mobile sources are contained 

in Chapter 3 of SCAQMD‘s Final 2007 Air Quality Management Plan 

(AQMP). The control strategy that is relied upon for the ―SIP-based‖ budgets 

is set out in Chapter 4 of SCAQMD‘s Final 2007 AQMP and Appendix IV-A, 

and in CARB‘s Staff report control measures and the total emissions inventory 

. (http://www.arb.ca.gov/planning/sip/2007sip/southcoast/scstaffreport.pdf) 

and appendices. The submittal dated April 30, 2008 made changes to the 

budgets to reflect the use of EMFAC2007, but the changes (relative to those 

calculated using SCAQMD‘s CEPA model) were minor and the emissions 

estimates remained consistent with the RFP demonstrations for 8-hour ozone 

or PM2.5 in the 2007 South Coast SIP, as supplemented for 8-hour ozone RFP 

on February 1, 2008. The ―offmodel‖ adjustments to the baseline inventory, as 

referenced in the footnote to the motor vehicle emissions budgets, for the 

motor vehicle emission budgets, are available on pages 73 (NOx), 76 (ROG) 

and 79 (PM2.5) of Appendix A, the Emission Inventory Output Tables, of the 

May 7, 2007 update to the Revised Statewide Strategy for California's 2007 

SIP. The relationship of the emission inventory to control measures and the 

reductions from the measures are described in Appendix A , D and E of the 

2011 Progress Report and Attachment 4 included in a May 18, 2011 letter 

from Lynn Terry, Deputy Executive Officer, CARB to Elizabeth Adams, 

Deputy Director, EPA Region 9 Air Division. 
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Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(vi)

Revisions to previously submitted 

control strategy or maintenance plans 

explain and document any changes to 

any previous submitted budgets and 

control measures; impacts on point 

and area source emissions; any 

changes to established safety margins 

(see §93.101 for definition), and 

reasons for the changes (including 

the basis for any changes to emission 

factors or estimates of vehicle miles 

traveled).

Y

CARB submitted revisions to the attainment and RFP demonstration in the 

South Coast 2007 AQMP as part of the 2011 Progress Report. See Appendices 

A – D and Attachment 4 included in a May 18, 2011 letter from Lynn Terry, 

Deputy Executive Officer, to Elizabeth Adams, Deputy Director. Attachment 

A specifically documents the changes in the planning factors, the new heavy 

duty truck inventory and the revisions to the control measures included in the 

revised budgets from the original budgets. EPA analyzed the information 

included in these reports to confirm that the MVEBs are consistent with 

previous MVEBs and revised as documented 

Note that CARB did not update the MVEB for 2009 because the 2009 budgets 

are longer needed for any conformity determination in the South Coast area. 

2011 Progress Report, Appendix D and 2011 Ozone SIP Revision, Appendix 

A.

CARB submitted revisions to the MVEBs removing the emission reductions 

associated with the AB 923 program on July 29, 2011 as part of the 8-Hour 

Ozone State Implementation Plan Revisions and Technical Revisions to the 

PM2.5 State Implementation Plan Transportation Conformity Budgets for the 

South Coast and San Joaquin Valley Air Basins, June 20, 2011, with 

Appendices. In combination, all of these reports document these changes, 

including changes to the previously submitted budgets, and the reasons for 

them. The revised budgets are posted at the following URL: 

http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm.
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EPA- Region 9 Page 147

Table J-3

Evaluation of the Motor Vehicle Emissions Budget in the 2011 Progress Report

May 2011

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(5)

EPA has reviewed the State‘s 

compilation of public comments and 

response to comments that are 

required to be submitted with any 

implementation plan.

Y

SCAQMD compiled public comments submitted during the June 1, 2007 

public hearing and during the public comment periods. These comments and 

the responses are included in the February 2007 ―Response to Comments‖ 

(http://www.aqmd.gov/aqmp/07/aqmp/modified/Response_to_Comments.pdf). 

ARB compiled public comments submitted during the September 27, 2007, 

November 15, 2007, and April 24, 2008 public hearings and during the public 

comment periods. These comments and the responses are included in adoption 

hearing transcripts (http://www.arb.ca.gov/board/meetings.htm). Additional 

written and verbal comments were received during the public comment period 

and public hearing on the 2011 Progress Report. See CARB Resolution 11-24, 

p. 3. We have reviewed the compilation of comments and responses and find 

the responses (where provided) to be acceptable. No issues that might have 

affected our adequacy finding remain unanswered.
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III. Response to Comments
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List of Comment Letters Received

We received six comment letters in response to our November 22, 2010 

proposal (75 FR 71294) and five comment letters on our July 14, 2011 supplemental 

proposal (76 FR 41562). We summarize the comments and provide responses to the 

comments in these letters in this final rule and the TSD insofar as they are relevant to this 

action.

Commenters on the November 22, 2010 proposal were:

1. [NRDC] Adrian Martinez, Project Attorney, Natural Resources Defense Council, 

January 21, 2011, ―EPA-R09-OAR-2009-0366, Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast State Implementation 

Plan for 1997 Fine Particulate Matter Standards; 2007 State Strategy; PM2.5,‖ with 

enclosures. These comments were joined by Jane Williams, Executive Director, 

California Communities Against Toxics, and Maya Golden-Krasner, Attorney, 

Communities for a Better Environment.

2. [CARB] James Goldstene, Executive Officer, California Air Resources Board, 

January 21, 2011. Attention: Docket No. EPA-R09-OAR-2009-0366.88

3. [AARR] Kirk Marckwald, Principal, California Environmental Associates, on behalf 

of the Association of American Railroads, January 20, 2011.Re: California Railroad 

Industry Comments on EPA‘s Proposed Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast State Implementation 

Plan for 1997 Fine Particulate Matter Standards; 2007 State Strategy.

4. [SCAQMD] Barry Wallerstein, Executive Officer, South Coast Air Quality 

Management District, January 20, 2011. Re: Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast State Implementation 

Plan for 1997 Fine Particulate Matter Standards; 2007 State Strategy PM2.5 (Docket 

No. EPA-R09-OAR-2009-0366)

5. [CBE] Maya Golden-Krasner, Staff Attorney, and Julia May, Senior Scientist, 

Communities for a Better Environment, January 21, 2011. Re: Docket No. EPA-R09-

OAR-2009-0366 CBE Comments on EPA‘s partial rejection of SCAQMD PM2.5 

planning

6. Email, Robin Hall, private citizen, November 24, 2010. 

Commenters on the July 14, 2011 proposal were:

1. [NRDC] Adrian Martinez, Project Attorney, Natural Resources Defense Council, 

August 15, 2011, ―EPA-R09-OAR-2009-0366, Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast State Implementation 

 

88 The majority of CARB‘s and the District‘s comments addressed the November 2010 proposed 

disapprovals and EPA‘s grounds for them. These comments were for the most part addressed by our July 

2011 amended proposal.
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Plan for 1997 Fine Particulate Matter Standards; 2007 State Strategy; PM2.5,‖ with 

enclosures. These comments were joined by Angela Johnson Meszaros, California 

Communities Against Toxics and Physicians for Social Responsibility, and Maya 

Golden-Krauser, Attorney, Communities for a Better Environment.

2. [CBE] Maya Golden-Krasner, Staff Attorney, Communities for a Better Environment, 

on behalf of California Communities Against Toxics, Communities for a Better 

Environment, Natural Resources Defense Council, and Physicians for Social 

Responsibility, August 15, 2011. Re: Docket No. EPA-R09-OAR-2009-0366,

Approval and Promulgation of Implementation Plans; State of California; 2007 South 

Coast PM2.5 Plan and 2007 State Strategy.

3. [SCAQMD] Barry Wallerstein, Executive Officer, South Coast Air Quality 

Management District, August 12, 2011. Re: Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast State Implementation 

Plan for 1997 Fine Particulate Matter Standards; 2007 State Strategy PM2.5 (Docket 

No. EPA-R09-OAR-2009-0366).

4. [CIAQC] Michael W. Lewis, Senior Vice President, Construction Industry Air 

Quality Coalition, August 15, 2011. RE: EPA-R09-OAR-2009-0366.

5. [ARTBA] Lawrence J. Joseph, on behalf of the American Road and Transportation 

Builders Association, dated August 15, 2011. RE: Approval and Promulgation of 

Implementation Plans; State of California; 2007 South Coast PM2.5 Plan and 2007 

State Strategy, 76 Fed Reg. 41,562 (July 14, 2011) (docket EPA-R09-OAR-2009-

0366)

A. Emissions Inventory 

Comment: NRDC comments that EPA proposes to approve the inventories in the South 

Coast 2007 AQMP because they were current and accurate ―at the time the Plan was 

developed and submitted,‖ citing 76 Fed. Reg. 41567. NRDC argues that such language 

is not in the CAA and the addition is not a reasonable extension of Congress‘s intent. 

NRDC argues that Congress did not mean for EPA to rely on inventory data that EPA 

knew to be incorrect on the basis that the data was thought to be accurate at the time it 

was submitted because Congress‘ goal is to ensure the adoption and approval of SIPs that 

will achieve clean air. NRDC notes that section 172(c)(3) expressly envisions that EPA 

may require revisions to the inventory ―to assure that the requirements of this part are 

met.‖ EPA‘s interpretation would suggest that the only time such revisions are needed is 

when it is found that the inventory is not current or accurate as of the date it is submitted 

and this would undermine any assurance that ―the requirements of [Part D] are met.‖ 

Response: EPA does not dispute the importance of emissions inventories. We evaluated 

the emissions inventories in the South Coast 2007 AQMP to determine whether they 

satisfy the requirements of CAA section 172(c)(3) and adequately support the PM2.5

Plan‘s RACM, RFP and attainment demonstrations. Based on this evaluation, we have 

concluded that the South Coast 2007 AQMP‘s base year emissions inventory was based 

on the most current and accurate information available to the State and District at the 

time that it was developed and submitted and comprehensively addresses all source 

categories in the South Coast area, consistent with applicable CAA requirements and 
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EPA guidance. See 76 FR 41562 at 41566-41567 and July 2011 TSD89 at section II.A.; 

see also ―General Preamble for Implementation of Title I of the Clean Air Act 

Amendments of 1990,‖ 57 FR 13498 at 13502 (April 16, 1992) (―General Preamble‖). 

We do not agree with NRDC‘s suggestion that this inventory undermines the attainment 

demonstration in the Plan, nor do we agree that revisions to an emissions inventory are 

needed only when it is found that such inventory is not current or accurate as of the date 

it is submitted. To the contrary, as discussed in the proposed rule (76 FR 41562, 41567) 

and in section II.B. below, we have concluded that the State‘s changes to its 

methodologies for estimating future emissions do not significantly affect the 2002 base 

year inventories and, consequently, do not undermine the modeling or other analyses that 

rely on those inventories. Although significant changes to a base year inventory that 

undermine the assumptions in an attainment demonstration may call for a more 

comprehensive reevaluation of the modeling and other planning analyses supporting that 

demonstration, we conclude based on our technical assessment that such a comprehensive 

reevaluation is not necessary in this case. We note that states are required to report 

comprehensive emissions inventories to EPA every three years under the Air Emissions 

Reporting Requirements in 40 CFR part 51, subpart A. See 40 CFR § 51.30(b).

CAA section 172(b) provides that ―the State containing [a nonattainment] area shall 

submit a plan or plan revision (including the plan items) meeting the applicable 

requirements of [section 172(c) and section 110]‖ on the schedule established by EPA, 

and section 172(c) contains, inter alia, the requirement that nonattainment plans ―shall 

include a comprehensive, accurate, current inventory of actual emissions from all sources 

of the relevant pollutant or pollutants in such area.‖ We believe it is reasonable to read 

these provisions together as requiring that the State submit an inventory that is 

―comprehensive, accurate, [and] current‖ at the time the State submitted it to EPA, rather 

than requiring that the State continually revise its plan as new emissions data becomes 

available. See Brief of Respondents, EPA, in Sierra Club, et al. v. U.S. EPA, et al., Case 

Nos. 10-71457 and 10-71458 (consolidated), May 5, 2011. States could never effectively 

plan for air quality improvement if they had to constantly revise their inventories as new 

data became available. Air quality planning is an iterative process and states and EPA 

must rely on the best available data at the time the plans are created.

Comment: NRDC questions EPA‘s calculations that estimated the emissions changes to 

the 2002 base year inventory (see 76 FR 41562, at 41567), noting that EPA‘s calculations 

come from a May 18, 2011 letter from CARB providing supplemental information. 

NRDC then assets that these numbers do not match with statements in staff reports on the 

diesel rules; however, NRDC does not provide the statements or data from the staff 

reports.

Response: As NRDC noted, EPA calculated the change in the 2002 base year emission 

inventory based on information provided in the 2011 Progress Report Supplement, 

 

89

 ―Technical Support Document for the Revised Proposed Rulemaking Action on the South Coast 2007 

AQMP for PM2.5 and the South Coast Portions of the 2007 State Strategy,‖ Air Division, U.S. EPA, 

Region 9, June 29, 2011, ―July 2011 TSD.‖ 
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transmitted by CARB on May 18, 2011. We took the difference between the ―SIP‖ 

estimate and the ―Current Estimate‖ columns in Attachment 1, Table SC-2002, to the 

May 18 letter and divided by the ―SIP‖ estimate to calculate the percent change in the 

inventories. We have added language to the TSD to explain these calculations. As we 

stated in our proposal, since late 2007, California has experienced an economic recession 

that has greatly reduced current levels of economic activity in the State‘s construction 

and goods movement sectors. The recession has resulted in lowered projected future 

levels of activity in this sector. 2011 Progress Report, Appendix E. As a result, projected 

emission levels from these categories are now substantially lower than the levels 

projected for 2008 and later in the Plan as submitted in 2007. At this time, California is 

addressing these recession impacts on future economic activity through adjustments to 

the baseline inventories for specific source categories. See 2011 Progress Report, 

Appendix E, page 2. There are no recession-related adjustments to the 2002 base year 

inventory in the South Coast 2007 AQMP. CARB also made technical changes to the 

inventories for diesel trucks, buses, and certain categories of off-road mobile source 

engines as part of its December 2010 rulemaking amending the In-Use On-Road Truck 

and Bus Rule and the In-Use Off-Road Engine rule. Id. The State estimates that these 

changes collectively reduce the 2002 base year total inventory in the South Coast by 4

percent for NOX and 5 percent for PM2.5. See 76 FR 41562, at 41567.

B. Credit for Baseline Measures 

Comment: NRDC asserts that EPA‘s proposed rule and TSD fail to clearly and accurately 

account for the measures that contribute to specific emission reductions, such as the 

Federal, state, and district rules adopted before October 2006 (―baseline measures‖) that 

are incorporated into the baseline inventory. NRDC argues that California and 

SCAQMD must have the data related to these emission reduction estimates, which are 

critical to the integrity of the Plan, and that an EPA approval of the emissions inventories 

in the absence of this data would be arbitrary and capricious. NRDC also argues that this

―gap in data‖ is made more problematic by the fact that EPA does not require 

California‘s mobile source control measures that have received a waiver of preemption 

under CAA section 209 (―waiver measures‖) to be approved into the SIP. Finally, NRDC 

questions why Table F-9 and Table G-1 in the TSD for our proposed rule contain 

significantly different estimates of the emission reductions attributed to baseline 

measures, and notes that these two tables also contain different 2002 baseline emissions 

levels.

Response: First, as to the difference between Tables F-9 and G-1 in the emission 

reductions attributed to baseline measures, this difference is due to the SIP revisions that 

ARB submitted in 2011 to account for CARB‘s revised emissions forecasts and other 

improvements to the emissions inventories. Table G-1 provides a summary of the 

attainment demonstration as submitted in November 2007. In this original submittal, the 

State used a 2006 base year emissions inventory.

90

 See Staff Report on 2007 State 

 

90 EPA had incorrectly labeled the baseline year as 2002 in line A of Table G-1. This error has been 

corrected. See September 2011 TSD at Table G-1.
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Strategy, September 21, 2007, p. 7, for 2006 baseline emissions estimates. Table F-9 

reflects several revisions that the State made to the SIP in 2011, including revisions to the 

projected baseline emissions inventories to account for changes in the methodologies for 

estimating emissions from the heavy duty truck and construction source categories. See

2011 Progress Report. Based on this revised SIP submission, which provided a 2002 

base year inventory (see 2011 Progress Report at 9 (Table 2)), we provided in Table F-9 

of our TSD a revised summary of the reductions needed from control strategy measures 

in the PM2.5 attainment demonstration for the South Coast. Table F-9 also identifies

adjustments that CARB made to the 2014 projected baseline inventory (see line E in 

Table F-9) based on information provided in Appendix E, Table 2 of the 2011 Progress 

Report.

Second, as to the commenter‘s assertion about the ―gap in data‖ regarding baseline 

measures and projected baseline inventories, we disagree that there is any inadequacy in 

the emissions projections that undermines the RACM, RFP or attainment demonstrations 

in the South Coast 2007 AQMP and 2007 State Strategy. We explained in our amended 

proposal (76 FR 41562 at 41566-41567) our reasons for concluding both that the 2002

base year inventory in the South Coast 2007 AQMP is comprehensive, accurate, and 

current as required by CAA section 172(c)(3) and that the projected baseline inventories 

for 2009, 2012 and 2014 provide adequate bases for the RACM, RFP and attainment 

demonstrations in the Plan. 

With respect to mobile source emissions, we believe that credit for emissions reductions 

from implementation of California mobile source rules that are subject to CAA section 

209 waivers (―waiver measures‖) is appropriate notwithstanding the fact that such rules 

are not approved as part of the California SIP. In the TSD supporting our July 14, 2011

proposal (76 FR 41562), we explained why we believe such credit is appropriate. See 

TSD at section II.F.4.a.i (pp. 97-100). Historically, EPA has granted credit for the waiver 

measures because of special Congressional recognition, in establishing the waiver 

process in the first place, of the pioneering California motor vehicle control program and 

because amendments to the CAA (in 1977) expanded the flexibility granted to California 

in order ―to afford California the broadest possible discretion in selecting the best means 

to protect the health of its citizens and the public welfare‖ (H.R. Rep. No. 294, 95th 

Congr., 1st Sess. 301-2 (1977)). In allowing California to take credit for the waiver 

measures notwithstanding the fact that the underlying rules are not part of the California 

SIP, EPA treated the waiver measures similarly to the Federal motor vehicle control 

requirements, which EPA has always allowed States to credit in their SIPs without 

submitting the program as a SIP revision. 

EPA‘s historical practice has been to give SIP credit for motor-vehicle-related waiver 

measures by allowing California to include motor vehicle emissions estimates made by 

using California‘s EMFAC (and its predecessors) motor vehicle emissions factor model 

in SIP inventories. EPA verifies the emissions reductions from motor-vehicle-related 

waiver measures through review and approval of EMFAC, which is updated from time to 

time by California to reflect updated methods and data, as well as newly-established 

emissions standards. (Emissions reductions from EPA‘s motor vehicle standards are 
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reflected in an analogous model known as MOVES.) The South Coast 2007 AQMP was 

developed using a version of the EMFAC model referred to as EMFAC2007, which EPA 

has approved for use in SIP development in California. See 73 FR 3464 (January 18, 

2008). Thus, the emissions reductions that are from the California on-road ―waiver 

measures‖ and that are estimated through use of EMFAC are as verifiable as are the 

emissions reductions relied upon by states other than California in developing their SIPs 

based on estimates of motor vehicle emissions made through the use of the MOVES

model and prior to the release of MOVES made through the use of the MOBILE model. 

All other states use the MOVES model in their baseline inventories without submitting 

the federal motor vehicle regulations for incorporation into their SIPs.

Similarly, emissions reductions that are from California‘s waiver measures for non-road 

engines and vehicles (e.g., agricultural, construction, lawn and garden and off-road 

recreation equipment) are estimated through use of CARB‘s OFFROAD emissions factor 

model.91 (Emissions reductions from EPA‘s non-road engine and vehicle standards are 

reflected in an analogous model known as NONROAD). Since 1990, EPA has treated 

California non-road standards for which EPA has issued waivers in the same manner as 

California motor vehicle standards, i.e., allowing credit for standards subject to the

waiver process without requiring submittal of the standards as part of the SIP. In so 

doing, EPA has treated the California non-road standards similarly to the Federal nonroad standards, which are relied upon, but not included in, various SIPs.

Moreover, to maintain a waiver under CAA section 209(b)(1), CARB‘s on-road waiver 

measures can be relaxed only to a level of aggregate equivalence to the Federal Motor 

Vehicle Control Program (FMVCP). See TSD at section II.F.4.a.i. In this respect, the 

FMVCP acts as a partial backstop to California‘s on-road waiver measures (i.e., absent a 

waiver, the FMVCP would apply in California). Likewise, Federal non-road vehicle and 

engine standards act as a partial backstop for corresponding California non-road waiver 

measures. The constraints of the waiver process thus serve to limit the extent to which 

CARB can relax these on-road and off- road waiver measures, thereby serving an antibacksliding function similar in substance to those established for SIP revisions in CAA 

sections 110(l) and 193.

CARB‘s EMFAC and OFFROAD models employ complex routines that predict vehicle 

fleet turnover by vehicle model years and include control algorithms that account for all 

adopted regulatory actions which, when combined with the fleet turnover algorithms, 

provide future baseline projections. See 2007 State Strategy, Appendix F at 7-8. For 

stationary sources, the California Emission Forecasting System (CEFS) projects future 

emissions from stationary and area sources (in addition to aircraft and ships) using a 

forecasting algorithm that applies growth factors and control profiles to the base year 

inventory.92 See id. at 7. The CEFS model integrates the projected inventories for both 

 

91 Information about CARB‘s emissions inventories for on-road and non-road mobile sources, and the 

EMFAC and OFFROAD models used to project changes in future inventories, is available at 

http://www.arb.ca.gov/msei/msei.htm.

92 Information on base year emissions from stationary point sources is obtained primarily from the districts, 

while CARB and the districts share responsibility for developing and updating information on emissions 
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stationary and mobile sources into a single database to provide a comprehensive 

statewide forecast inventory, from which nonattainment area inventories are extracted for 

use in establishing future baseline planning inventories. See id. The South Coast 2007 

AQMP describes how the District developed the future baseline inventories in the South 

Coast 2007 AQMP, based in part on the emissions data and baseline projections provided 

by CARB and other California agencies. See generally South Coast 2007 AQMP, 

Appendix III. The District‘s projections took into account the controls implemented 

under SCAQMD rules adopted as of June 2006, most CARB regulations adopted by June 

2005, and a specific set of growth rates from the Southern California Association of 

Governments (SCAG) for population, industry, and motor vehicle activity, among other 

factors. See id. at 2-3. In 2011, CARB updated the baseline emissions projections for 

several source categories to account for, among other things, more recent economic 

forecasts and improved methodologies for estimating emissions from the heavy duty 

truck and construction source categories. See 2011 Progress Report at Appendix E. 

These methodologies for projecting future emissions based on growth factors and 

existing Federal, State, and local controls were consistent with EPA guidance on 

developing projected baseline inventories. See TSD at section II.A; see also ―Procedures 

for Preparing Emissions Projections,‖ EPA Office of Air Quality Planning and Standards, 

EPA-450/4-91-019, July 1991; ―Emission Projections,‖ STAPPA/ALAPCO/EPA 

Emission Inventory Improvement Project, Volume X, December 1999 (available at 

http://www.epa.gov/ttnchie1/eiip/techreport/volume10/x01.pdf).

In sum, the 2002 base year and future projected baseline inventories in the South Coast 

2007 AQMP were prepared using a complex set of CARB and SCAQMD methodologies 

to estimate and project emissions from stationary sources, in addition to the most recent 

emissions factors and models and updated activity levels for emissions associated with 

mobile sources, including: (1) the latest EPA-approved California motor vehicle 

emissions factor model (EMFAC2007) and the most recent motor vehicle activity data 

from SCAG; (2) improved methodologies for estimating emissions from specific source 

categories; and (3) CARB's non-road mobile source model (the OFFROAD model). See 

TSD at Section II.A (referencing, inter alia, South Coast 2007 AQMP at Appendix III 

and 2007 State Strategy at Appendix F) and 2011 Progress Report. EPA has approved 

numerous California SIPs that rely on base year and projected baseline inventories 

including emissions estimates derived from the EMFAC, OFFROAD, and CEFS models. 

See, e.g., 65 FR 6091 (February 8, 2000) (proposed rule to approve 1-hour ozone plan for 

South Coast) and 65 FR 18903 (April 10, 2000) (final rule); 70 FR 43663 (July 28, 2005) 

(proposed rule to approve PM-10 plan for South Coast and Coachella Valley) and 70 FR 

69081 (November 14, 2005) (final rule); 74 FR 66916 (December 17, 2009) (direct final 

rule to approve ozone plan for Monterey Bay). The commenter has provided no 

information to support a claim that these methodologies for developing base year 

inventories and projecting future emissions in the South Coast are inadequate to support 

the RACM, RFP, and attainment demonstrations in the South Coast 2007 AQMP. 

 

from various area source categories. See 2007 State Strategy, Appendix F at 21; see also South Coast 2007 

AQMP, Appendix III at pp. 1-9 through 1-15 (describing the SCAQMD‘s and CARB‘s methodologies for 

developing 2002 base year emissions estimates for stationary point and area sources).
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For all of these reasons and as discussed in our amended proposal (76 FR 41562 at 

41566-41567), we have concluded that the 2002 base year inventory in the South Coast 

2007 AQMP is a ―comprehensive, accurate, current inventory of actual emissions from 

all sources of the relevant pollutant or pollutants‖ in the South Coast area, consistent with 

the requirements for emissions inventories in CAA section 172(c)(3), 40 CFR 51.1008, 

and 40 CFR part 51, subpart A. In addition, we conclude that the projected baseline 

inventories for 2009, 2012 and 2014 were prepared consistent with EPA‘s guidance on 

development of emissions inventories and attainment demonstrations and, therefore, 

provide an adequate basis for the RACM, RFP and attainment demonstrations in the Plan. 

See TSD at section II.A. 

C. PM2.5 Plan Precursors 

Comment: NRDC commented that our proposed rule does not adequately explain why 

ammonia (NH3) is not a precursor for PM2.5 formation. 

Response: Under the PM2.5 implementation rule, ammonia is not a PM2.5 plan precursor 

unless either EPA or the State provides an appropriate technical demonstration showing 

that ammonia emissions from sources in the State significantly contribute to PM2.5

concentrations in the nonattainment area. See 40 CFR § 51.1002(c)(4). Absent such a 

technical demonstration, the State is not required to address ammonia in its PM2.5

attainment plan or to evaluate sources of ammonia emissions in the State for control 

measures.

D. Air Quality Monitoring, Air Quality Modeling and Attainment 

Demonstration

Comment: NRDC states that it has provided significant comments on the 2011 Annual 

Monitoring Plan for the South Coast Air Basin. NRDC states that the issues raised in 

those comments apply here, and that they incorporate those comments by reference on 

the present plan revision. Specifically, the design flaws in the monitoring network, which 

ignores near highway areas, must be remedied prior to approval of this SIP. In particular, 

in light of EPA‘s conclusion that higher concentrations of pollutants are linked to traffic 

levels and proximity to the roadway, it is clear that a monitoring plan that fails to include 

monitors within the impact zone of highways fails to satisfy numerous criteria in 40 CFR

Part 58, including the requirement to site a monitor at the point of maximum expected 

concentration in the nonattainment area, and the requirement that the monitoring network 

be adequate to support a demonstration that the SIP will provide for attainment. 

NRDC‘s comment letter submitted to the South Coast Air Quality Management District 

during the review period of the 2011 Annual Monitoring Network Plan states that:

―For the reasons described below, the Air Monitoring Network Plan fails to meet 

the requirements established in the Clean Air Act and applicable regulations. 

Specifically, the Air Monitoring Network Plan fails to adequately monitor near 

heavily trafficked highways, especially those with a large share of diesel trucks. 

As it relates to Particulate Matter less than 2.5 micrometers in diameter (―PM 
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2.5‖), EPA‘s monitoring regulations require placement of at least one monitor in a 

population-oriented area of expected maximum concentration. The comments and 

the appended materials indicate that the Air Monitoring Network Plan has failed 

to comply with this provision because it fails to include adequate monitoring near 

major roadways.‖

Response: EPA has approved previous Annual Monitoring Network Plans (2007-2010) 

submitted by South Coast Air Quality Management District and determined that the 

PM2.5 network covered under the Annual Monitoring Network Plan meets regulatory 

requirements.

The requirements for the Annual Monitoring Network Plan are found in 40 CFR 58.10. 

The relevant parts of this regulation are listed below:

(a)(1) Beginning July 1, 2007, the State, or where applicable local, agency shall 

adopt and submit to the Regional Administrator an annual monitoring network 

plan which shall provide for the establishment and maintenance of an air 

quality surveillance system that consists of a network of SLAMS monitoring 

stations including FRM, FEM, and ARM monitors that are part of SLAMS, 

NCore stations, STN stations, State speciation stations, SPM stations, and/or, 

in serious, severe and extreme ozone nonattainment areas, PAMS stations, and 

SPM monitoring stations. The plan shall include a statement of purposes for 

each monitor and evidence that siting and operation of each monitor meets the 

requirements of appendices A, C, D, and E of this part, where applicable. The 

annual monitoring network plan must be made available for public inspection 

for at least 30 days prior to submission to EPA.

(2) Any annual monitoring network plan that proposes SLAMS network 

modifications including new monitoring sites is subject to the approval of the 

EPA Regional Administrator, who shall provide opportunity for public 

comment and shall approve or disapprove the plan and schedule within 120 

days. If the State or local agency has already provided a public comment 

opportunity on its plan and has made no changes subsequent to that comment 

opportunity, and has submitted the received comments together with the plan, 

the Regional Administrator is not required to provide a separate opportunity 

for comment.

(3) [NCore: not relevant for PM2.5].

(4) [Pb: not relevant for PM2.5]

(5) [NO2: not relevant for PM2.5]

(6) [SO2: not relevant for PM2.5]

(b) The annual monitoring network plan must contain the following information 

for each existing and proposed site:

(1) The AQS site identification number.
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(2) The location, including street address and geographical coordinates.

(3) The sampling and analysis method(s) for each measured parameter.

(4) The operating schedules for each monitor.

(5) Any proposals to remove or move a monitoring station within a period of 

18 months following plan submittal.

(6) The monitoring objective and spatial scale of representativeness for each 

monitor as defined in appendix D to this part.

(7) The identification of any sites that are suitable and sites that are not 

suitable for comparison against the annual PM2.5NAAQS as described in 

§58.30.

(8) The MSA, CBSA, CSA or other area represented by the monitor.

(9) The designation of any Pb monitors as either source-oriented or nonsource-oriented according to Appendix D to 40 CFR part 58.

(10) Any source-oriented monitors for which a waiver has been requested or 

granted by the EPA Regional Administrator as allowed for under paragraph 

4.5(a)(ii) of Appendix D to 40 CFR part 58.

(11) Any source-oriented or non-source-oriented site for which a waiver has 

been requested or granted by the EPA Regional Administrator for the use of 

Pb-PM10 monitoring in lieu of Pb-TSP monitoring as allowed for under 

paragraph 2.10 of Appendix C to 40 CFR part 58.

(12) The identification of required NO2monitors as either near-road or areawide sites in accordance with appendix D, section 4.3 of this part.

(c) The annual monitoring network plan must document how States and local 

agencies provide for the review of changes to a PM2.5monitoring network that 

impact the location of a violating PM2.5monitor or the creation/change to a 

community monitoring zone, including a description of the proposed use of 

spatial averaging for purposes of making comparisons to the annual 

PM2.5NAAQS as set forth in appendix N to part 50 of this chapter. The affected 

State or local agency must document the process for obtaining public comment 

and include any comments received through the public notification process within 

their submitted plan.

(d) [Network Assessment: not relevant for Annual Monitoring Network Plan]

(e) [Approval of discontinuations or additions: not relevant for comments]

Comments within the scope of the Annual Monitoring Network Plan, as outlined above in 

40 CFR 58.10 and Appendices referenced therein, are addressed in this response. 
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Network design requirements for PM2.5 are specified in 40 CFR 58, Appendix D, Section 

4.7.1. The relevant text is provided below:

4.7.1 General Requirements. (a) State, and where applicable local, agencies must 

operate the minimum number of required PM2.5SLAMS sites listed in Table D–5 

of this appendix. The NCore sites are expected to complement the PM2.5 data 

collection that takes place at non-NCore SLAMS sites, and both types of sites can 

be used to meet the minimum PM2.5 network requirements. Deviations from these 

PM2.5 monitoring requirements must be approved by the EPA Regional 

Administrator.

Table D–5 of Appendix D to Part 58—PM2.5 Minimum Monitoring Requirements

MSA population1,2

Most recent 3-year design value 

≥85% of any PM2.5 NAAQS3

Most recent 3-year design value 

<85% of any PM2.5 NAAQS3,4

>1,000,000 3 2

500,000–1,000,000 2 1

50,000–<500,00051 0

1Minimum monitoring requirements apply to the Metropolitan statistical area (MSA).

2

Population based on latest available census figures.

3The PM2.5 National Ambient Air Quality Standards (NAAQS) levels and forms are 

defined in 40 CFR part 50.

4These minimum monitoring requirements apply in the absence of a design value.

5Metropolitan statistical areas (MSA) must contain an urbanized area of 50,000 or more 

population.

(b) Specific Design Criteria for PM2.5. The required monitoring stations or sites 

must be sited to represent community-wide air quality. These sites can include 

sites collocated at PAMS. These monitoring stations will typically be at 

neighborhood or urban-scale; however, in certain instances where populationoriented micro-or middle-scale PM2.5 monitoring are determined by the Regional 

Administrator to represent many such locations throughout a metropolitan area, 

these smaller scales can be considered to represent community-wide air quality.

(1) At least one monitoring station is to be sited in a population-oriented area 

of expected maximum concentration.

(2) For areas with more than one required SLAMS, a monitoring station is to 

be sited in an area of poor air quality.

(3) Additional technical guidance for siting PM2.5 monitors is provided in 

references 6 and 7 of this appendix.

(c) The most important spatial scale to effectively characterize the emissions of 

particulate matter from both mobile and stationary sources is the neighborhood 

scale for PM2.5. For purposes of establishing monitoring sites to represent large 

homogenous areas other than the above scales of representativeness and to 
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characterize regional transport, urban or regional scale sites would also be needed. 

Most PM2.5 monitoring in urban areas should be representative of a neighborhood 

scale.

The South Coast Air Basin includes all of the Los Angeles-Long Beach-Santa Ana MSA 

and part of the Riverside-San Bernardino-Ontario MSA. Based on the network design 

criteria specified in 40 CFR 58, Appendix D, Section 4.7.1, the South Coast Air Quality 

Management District is required to operate six monitors between these two MSAs. There 

are 19 monitors operated by South Coast AQMD in the South Coast Air Basin (21 total in 

the two MSAs). The South Coast Air Quality Management District exceeds the number 

of required monitors. 

As stated in Section 4.7.1(c), ―The most important spatial scale to effectively characterize 

the emissions of particulate matter from both mobile and stationary sources is the 

neighborhood scale for PM2.5.‖ As stated in Section 4.7.1(b), the required monitoring 

sites must be sited to represent community-wide air quality, which will typically be at 

neighborhood or urban-scale. Neighborhood and urban-scale sites require a minimum 

distance from roadways with AADT >100,000 of 100 m and 160 m, respectively (40 

CFR 58, Appendix E, Figure E-1). Section 4.7.1(b) does allow for instances where 

―population-oriented micro-or middle-scale PM2.5 monitoring are determined by the 

Regional Administrator to represent many such locations throughout a metropolitan area, 

these smaller scales can be considered to represent community-wide air quality.‖ Such a 

determination has not been made for the South Coast Air Basin and therefore the network 

design remains focused on the neighborhood and urban-scale as directed by Section 

4.7.1(c). EPA has therefore determined that the monitoring network in the South Coast 

Air Basin meets network design criteria as specified in 40 CFR 58, Appendix D. Further, 

the Annual Monitoring Network Plans submitted to EPA have met all other requirements 

as specified in 40 CFR 58.10 and have therefore been approved. EPA has not yet 

reviewed the 2011 Annual Monitoring Network Plan but intends to do so within the 

timeframe required by 40 CFR 58.10, which allows 120 days for review of these plans.

Comment: NRDC commented that, ―When state or local agencies submit an air quality 

monitoring plan that proposes modifications or new monitoring sites, the EPA Regional 

Administrator is required to allow time for public comment.‖ 

Response: As stated above in the provisions for 40 CFR 58.10, ―If the State or local 

agency has already provided a public comment opportunity on its plan and has made no 

changes subsequent to that comment opportunity, and has submitted the received 

comments together with the plan, the Regional Administrator is not required to provide a 

separate opportunity for comment.‖ The letter from the South Coast Air Quality 

Management District with its submittal of the 2011 Annual Monitoring Network Plan 

indicates that a 30-day comment period was provided and that no changes were made to 

the plan subsequent to that comment period; therefore, the Regional Administrator is not 

required to provide a separate opportunity for comment.
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Comment: NRDC comments that monitors in the South Coast Basin are not located to 

measure PM2.5 in near-highway environment.

Response: The 1997 and 2006 Monitoring Rules impose minimum monitoring 

requirements and specify which monitors‘ data are to be compared to the annual and the 

24-hour PM2.5 NAAQS to determine whether those NAAQS have been attained. The 

PM2.5 NAAQS were promulgated in 1997 to protect the public on an average, 

community-wide basis,93 and both the PM2.5 levels to which the public could be exposed 

and the types of monitoring sites at which States could determine attainment were 

codified in the NAAQS and Monitoring Rules themselves. The 1997 annual and 24-hour 

NAAQS were set at 15 and 65 ug/m3, respectively, and States were instructed to 

determine attainment in accordance with Appendix N of 40 CFR Pt 50. See 40 CFR § 

50.7(b, c). Appendix N, in turn, requires States to compare ambient PM2.5 levels at 

those air network monitors the Monitoring Rules deem eligible for making comparisons 

with the NAAQS in order to determine whether they have been attained. 40 CFR Pt 50, 

App. N, § 2.4(a) (1997). Appendix D, which was significantly amended by the 1997 and 

2006 Monitoring Rules, imposes detailed requirements for siting network monitors, 

including PM2.5 monitors. To ensure that States collect PM2.5 exposure data comparable 

to that used in the studies on which the NAAQS were based, the 1997 Monitoring Rule 

stated that monitors collecting data for comparison to the annual PM2.5 NAAQS should 

be located in neighborhood-scale community-oriented locations. 40 CFR Pt 58, App. D, § 

2.8.1.2.2.

The most important spatial scales to effectively characterize the emissions of 

particulate matter from both mobile and stationary sources are the middle scales 

for PM10 and neighborhood scales for both PM10 and PM2.5. Most PM2.5 

monitoring in urban areas should be representative of a neighborhood scale.

In the 2006 PM2.5 Monitoring Rule, EPA retained the 1997 requirements for locating 

monitors and using their data for determining attainment of the annual PM2.5 NAAQS. 

EPA also responded to public comments seeking mandatory monitoring in 

―microenvironment or hot spot locations,‖ by expressly declining to require such 

monitoring for either the annual or the 24-hour PM2.5 NAAQS.94 Consequently, neither 

 

93 Unlike some other NAAQS, the PM2.5 NAAQS were intended to reduce aggregate population risk from 

both annual and 24-hour exposures by lowering the broad distribution of PM2.5 concentrations across the 

community to a level slightly below that associated with adverse health effects in epidemiological studies 

of the relationship between adverse health effects and average, community-wide levels of particulate 

matter. 61 Fed. Reg. at 65,641/2; see 62 Fed. Reg. at 38,655-56, 38,665/2-3, 38,671/2, 38,672/2, 38,764; 40 

C.F.R. § 50.7 (1997); id. Pt 58, App. D, § 2.8.1.2.3 (1997).

94

 In the [proposed 2006 Monitoring Rule] EPA said it believed that the 1997 rule‘s design criteria 

remained appropriate for implementation of the proposed [annual] PM2.5 NAAQS, . . . because these 

requirements effectively ensured that monitors are placed in locations that appropriately reflect the 

community-oriented area wide concentration levels used in the epidemiological studies that support the 

proposed lowering of the 24-hour PM2.5 NAAQS. 71 FR 2742. The EPA continues to believe this . . . . .

... While an implication of the final monitoring rule provisions regarding siting of PM2.5 monitors is that 

States may choose not to monitor microenvironment or middle scale locations where some people are 
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the 1997 nor the 2006 Monitoring Rule contains any requirement that States place PM2.5 

monitors in Middle Scale or Microscale areas (including those in the vicinity of highways 

or other dominating local sources of PM2.5), and both expressly limit the circumstances 

in which data from such monitors may be used to demonstrate attainment of the annual 

NAAQS. See 71 Fed. Reg. at 61,264 (2006). 

As discussed above, the South Coast Air Quality Management District exceeds the 

minimum number of required monitors and meets all other requirements of the 1997 and 

2006 monitoring rules. EPA has therefore determined that the monitoring network in the 

South Coast Air Basin meets network design criteria as specified in 40 CFR 58, 

Appendix D. 

Comment: NRDC comments that reliable scientific evidence shows elevated PM2.5 in 

the near-highway environment and that the exposed population in near-highway 

environment is significant.

Response: Regardless of the magnitude of near-highway PM2.5 gradients, the monitoring 

rules do not require placement of PM2.5 monitors in micro or middle scale locations. The 

South Coast Air Quality Management District exceeds the number of required monitors. 

As stated in Section 4.7.1(c), ―The most important spatial scale to effectively characterize 

the emissions of particulate matter from both mobile and stationary sources is the 

neighborhood scale for PM2.5.‖ As stated in Section 4.7.1(b), the required monitoring 

sites must be sited to represent community-wide air quality, which will typically be at 

neighborhood or urban-scale. Neighborhood and urban-scale sites require a minimum 

distance from roadways with AADT >100,000 of 100 m and 160 m, respectively (40 

CFR 58, Appendix E, Figure E-1). Section 4.7.1(b) does allow for instances where 

―population-oriented micro-or middle-scale PM2.5 monitoring are determined by the 

Regional Administrator to represent many such locations throughout a metropolitan area, 

these smaller scales can be considered to represent community-wide air quality.‖ EPA 

has not made such a determination for the South Coast Air Basin and therefore the 

network design remains focused on the neighborhood and urban-scale as directed by 

Section 4.7.1(c). EPA has therefore determined that the monitoring network in the South 

Coast Air Basin meets network design criteria as specified in 40 CFR 58, Appendix D.

Comment: NRDC comments that data from several highway studies were expressly 

relied upon by US EPA to decide that it must establish a transportation conformity 

program to review the localized impacts of PM2.5 emissions from highways. NRDC 

states that EPA concluded that the evidence of localized impacts from highways was 

sufficiently compelling to require that ―it is essential that a quantitative PM2.5 or PM10 

hot-spot analysis be performed for all projects of air quality concern.‖ NRDC argues that 

if the evidence of localized impacts was sufficient to justify a national regulatory 

program to protect against NAAQS violations caused by new highways, it is also 

 

exposed to 24-hour concentrations above the . . . 24-hour NAAQS, such a result remains consistent with the 

community-oriented area-wide level of protection on which the 24-hour PM2.5 NAAQS is premised. Thus 

. . . it is not appropriate to specifically require any number of monitors to be placed in microenvironment or 

hot spot locations.
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compelling enough to require a quantitative analysis to ensure that the SIP will protect 

against existing localized NAAQS violations caused by highway emissions.

NRDC also comments that EPA has developed and issued formal Guidance for the 

evaluation of highway emissions to implement the Hot Spot conformity program, 

Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and 

PM10 Nonattainment and Maintenance Areas,‖ US EPA (December 2010). 75 FR 79370 

(December 20, 2010). NRDC comments that these tools should be required for the 

determination of the concentrations expected near heavily trafficked highways in the 

parts of the nonattainment area with the highest background pollutant concentrations.

Response: EPA‘s Implementation Rule requires that states should prepare attainment 

demonstrations through modeling that is ―consistent with EPA‘s modeling guidance,‖ 

and the modeling guidance explains that future air quality should be estimated at current 

monitoring sites. 72 Fed. Reg. 20,586 (Apr. 25, 2007).; see ―Guidance on the Use of 

Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for 

Ozone, PM2.5, and Regional Haze,‖ prepared by EPA‘s Office of Air Quality Planning 

and Standards, at 15 (April 2007). The transportation conformity program is established 

to meet different statutory and regulatory programs than those that are applicable to the 

SIP action before EPA. Therefore the conformity Hot spot rule and guidance is not 

applicable to the attainment test for the South Coast PM2.5 SIP. However, it is worth 

noting that the conformity hot spot modeling rule and guidance limit the hot spot analysis 

to locations that are appropriate for siting an FRM PM2.5 monitor. In addition, the 

attainment demonstration modeling guidance recommendations specify analysis at spatial 

resolutions which are consistent with monitoring rule requirements. The SCAQMD 

attainment demonstration adequately demonstrates attainment of the PM2.5 NAAQS at 

spatial scales that are consistent with both the monitoring rule and modeling guidance 

requirements.

Comment: NRDC comments that large-scale regional modeling does not predict impact 

of reductions in highway emissions. The modeling analysis performed for the attainment 

demonstration uses the CAMx model, a regional airshed model that aggregates emissions 

and estimates ambient concentrations for a grid that is made up of cells 5 km on a side. 

NRDC argues that EPA explained in its guidance regarding PM attainment 

demonstrations that ―[d]ispersion models are better able to capture the influence of 

primary PM sources where large concentration gradients may exist. Grid models spread 

out the PM emissions to the size of the grid (typically 4 or 12 km). This makes it difficult 

to judge the benefits of control strategies that may affect primary PM sources.‖ 72 Fed. 

Reg. 20607-08.

NRDC also comments that small scale modeling tools are available, and that EPA‘s 

modeling guidance identifies the problem that NRDC has identified, and suggests 

suitable models for assessing the expected ambient impacts of primary PM emissions on 

locations that are not represented by the monitoring network. The comment indicates that 

the ―Guidance on the Use of Models and Other Analyses for Demonstrating Attainment 

of Air Quality Goals for Ozone, PM2.5, and Regional Haze,‖ p.19, warns specifically of 
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the possibility that high concentration locations affected by emissions of primary PM will 

be missed:

Focusing the modeled attainment test only at monitoring sites could result in 

control targets which are too low if the monitoring network is limited or poorly 

designed. We recommend a test which includes a review of the strategy‘s impact 

at locations without monitors. This exercise provides a supplemental test to 

determine whether there is a need for further action despite passing the modeled 

attainment test at all monitoring sites. 

Response: The Implementation Rule requires that states prepare attainment 

demonstrations through modeling that is ―consistent with EPA‘s modeling guidance,‖ 

and the modeling guidance explains that future air quality should be estimated at current 

monitoring sites. 72 Fed. Reg. 20,586 (Apr. 25, 2007).; see ―Guidance on the Use of 

Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for 

Ozone, PM2.5, and Regional Haze,‖ prepared by EPA‘s Office of Air Quality Planning 

and Standards, at 15 (April 2007). The guidance also recommends that States perform 

supplemental analyses for unmonitored areas which would support the modeled 

attainment test by identifying potential ―large-scale‖ NAAQS violations in areas with 

inadequate monitoring networks. The guidance recommends an unmonitored analysis at 

12km or finer resolution for the annual PM2.5 NAAQS, and 4 km or finer resolution for 

the 24-hr PM2.5 NAAQS. The modeling guidance recommendations are consistent with 

the requirements of the monitoring rules. The modeling guidance unmonitored area 

analysis spatial scale recommendations are intended to capture neighborhood scale and 

larger areas, since the monitoring rules do not require micro or middle scale monitors for 

either the annual or 24-hr PM2.5 NAAQS.

In addition to the attainment test which showed attainment at all grid cells with monitors, 

the SCAQMD performed an unmonitored area analysis at 5 km resolution and showed 

attainment at all grid cells without monitors. The grid resolution of the South Coast 

unmonitored area analysis is consistent with the modeling guidance recommendations 

and appropriately represents unmonitored neighborhood and larger scale areas.

Comment: NRDC comments that EPA modeling guidance specifically calls for the need 

to identify unmonitored areas where monitored concentrations are not expected to be 

representative of local air quality and to apply Gaussian dispersion models to make up for 

the limitations of regional scale grid models to determine if additional control measures 

are needed.

Response: As discussed in the previous comment, the unmonitored area analysis was 

performed by SCAQMD and shows attainment at all grid cells without monitors, in 

addition to the attainment test which also showed attainment at all grid cells with 

monitors. 

NRDC states that EPA modeling guidance specifically calls for the need to identify 

unmonitored areas where monitored concentrations are not expected to be representative 
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of local air quality and to apply Gaussian dispersion models. However, the commenter is 

confusing two distinct sections and recommendations in the modeling guidance. Section 

5.3 of the modeling guidance contains the recommended spatial resolution for the 

unmonitored area analysis. This section recommends a relatively large scale 

unmonitored area analysis at typical photochemical grid model resolutions of 12km or 

4km. Section 5.3.1 begins a discussion examining impacts from local primary PM2.5 

sources at monitoring locations. Sections 5.3.1 and 5.3.2 contain recommendations to 

potentially use a Gaussian dispersion model to estimate impacts of primary PM2.5 

sources at existing monitor locations, where data indicates that local gradients of primary 

PM2.5 exist. The guidance does not recommend the use of Gaussian dispersion models 

to examine impacts in non-monitored areas. 

Existing PM2.5 monitors may be located in areas with relatively high primary PM2.5 

gradients. In some cases these locations may be micro or middle scale areas where states 

have voluntarily sited PM2.5 monitors. Attainment of the NAAQS must be shown at 

these monitors. Using a combination of photochemical and dispersion models may be the 

most credible method of examining attainment issues in such locations. But it should be 

clear that the use of dispersion models is strictly voluntary and should be considered on a 

case-by-case basis. And the modeling guidance does not recommend a similar technique 

for unmonitored areas (at monitoring scales) where PM2.5 monitors would not be 

required.

Comment: NRDC comments that the Clean Air Act provides no authority to support 

EPA‘s contention that it may create what are in effect permanent public health sacrifice 

areas by allowing certain neighborhoods to be exposed to PM2.5 concentrations that 

exceed NAAQS by merely not monitoring pollution levels in those areas. To create such 

a public health sacrifice area would not only violate the express mandate of the Clean Air 

Act, but would also deprive the individuals and families in those neighborhoods of the 

equal protection of the laws guaranteed by the Fourteenth Amendment of the United 

States Constitution. For the government to permissibly discriminate between citizens, it 

must have a rational basis for making the distinction. Here there is no rational basis for 

the State to discriminate between families in protecting against the adverse health effects 

of fine particles based on proximity to highways. It is not permissible to adopt an air 

quality plan that denies to some families the full protection from premature death and 

disease achieved when the NAAQS is attained. Neither the Constitution nor the CAA 

makes proximity to sources or population density a factor that the EPA may rely upon to 

justify approving an implementation plan that fails to provide equal protection to all 

families from the health effects of air pollution.

Response: As discussed in greater detail in the response above, the 1997 and 2006 

Monitoring Rules impose minimum monitoring requirements and specify which 

monitors‘ data are to be compared to the annual and the 24-hour PM2.5 NAAQS to 

determine whether those NAAQS have been attained. The PM2.5 NAAQS were 

promulgated in 1997 to protect the public on an average, community-wide basis,95 and 

 

95 Unlike some other NAAQS, the PM2.5 NAAQS were intended to reduce aggregate population risk from 

both annual and 24-hour exposures by lowering the broad distribution of PM2.5 concentrations across the 
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both the PM2.5 levels to which the public could be exposed and the types of monitoring 

sites at which States could determine attainment were codified in the NAAQS and 

Monitoring Rules themselves. 

Comment: NRDC comments that until California submits an attainment demonstration 

for PM2.5 that provides for attainment in the near-highway environment, and the 

measures needed to achieve the reductions required to attain are identified, quantified and 

adopted in legally enforceable form, it is premature to establish any emission budgets for 

PM2.5 emissions from motor vehicles. We therefore ask EPA to continue its disapproval 

of the submitted motor vehicle emission budgets until these deficiencies in the South 

Coast SIP are remedied.

Response: EPA disagrees with the commenters‘ assertions that motor vehicle emissions 

budgets can only be established after the PM2.5 attainment demonstration is revised to 

address the commenters‘ concerns about near roadway concentrations and that EPA 

should disapprove the submitted budgets. 

EPA has completed its detailed and thorough review of the entire PM2.5 SIP for the 

South Coast Air Basin and, as documented in the preamble to final rulemaking, the 

technical support document and in responses to other submitted comments, concluded 

that the submitted SIP complies with Clean Air Act and PM2.5 implementation rule 

requirements and associated guidance for demonstrating that the area will attain the 

PM2.5 standard and that the area will make reasonable further progress toward attaining 

that standard. In the course of that thorough review of the entire submitted SIP, EPA 

concluded that the attainment demonstration for the 1997 PM2.5 NAAQS appropriately 

provides for attainment in all areas of the South Coast Air Basin. EPA also concluded 

that the attainment demonstration modeling and the PM2.5 monitoring data used for the 

attainment demonstration follow the appropriate EPA guidance for modeling and 

monitoring. Specifically, as described in the responses to other comments, the submitted 

attainment demonstration included demonstrations for both monitored and unmonitored 

areas that are consistent with EPA‘s attainment modeling guidance. 

As part of this thorough review of the submitted PM2.5 SIP for the area EPA reviewed

the motor vehicle emissions budgets and concluded that they are both adequate for 

transportation conformity purposes and are approvable. The motor vehicle emissions 

budgets for the RFP years and for the attainment year meet all of the adequacy criteria 

contained in the transportation conformity rule (40 CFR 93.118(e)(4) and (5)) The 

requirements of 40 CFR 93.118(e)(4)(iv) are most relevant to the concerns raised in this 

comment. Specifically, 40 CFR 93.118(e)(4)(iv) states that:

 

community to a level slightly below that associated with adverse health effects in epidemiological studies 

of the relationship between adverse health effects and average, community-wide levels of particulate 

matter. 61 Fed. Reg. at 65,641/2; see 62 Fed. Reg. at 38,655-56, 38,665/2-3, 38,671/2, 38,672/2, 38,764; 40 

CFR § 50.7 (1997); id. Pt 58, App. D, § 2.8.1.2.3 (1997).
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The motor vehicle emissions budget(s), when considered together with all other 

emissions sources, is consistent with applicable requirements for reasonable 

further progress, attainment, or maintenance (whichever is relevant to the given 

implementation plan submission).

In this case the relevant requirements are reasonable further progress and attainment. 

EPA‘s thorough review of the SIP resulted in a conclusion that the SIP provides for 

attainment throughout the entire nonattainment area and, in light of Clean Air Act and 

PM2.5 implementation rule requirements, is approvable. EPA also concluded that the 

SIP provides for reasonable further progress as required by the Clean Air Act and the 

PM2.5 implementation rule because the SIP provides for a level of emissions that will 

result in attainment of the 1997 PM2.5 NAAQS throughout the entire area and that the 

SIP documents generally linear progress toward attainment of the PM2.5 NAAQS. The 

motor vehicle emissions budgets are the on-road portions of the overall emissions 

inventories for the attainment year and the RFP years. Therefore, EPA concluded that the 

motor vehicle emissions budgets meet the requirements of 40 CFR 93.118(e)(4)(iv). 

Also, relevant to this comment are the requirements of 40 CFR 93.118(e)(4)(v) which 

states that:

The motor vehicle emissions budget(s) is consistent with and clearly related to the 

emissions inventory and the control measures in the submitted control strategy 

implementation plan revision or maintenance plan.

EPA‘s thorough review of the SIP led it to conclude that motor vehicle emissions budgets 

are consistent with the overall inventory for the area, that the budgets are budgets and the 

overall inventory are based on adopted control measures and approvable enforceable 

commitments and that the entire SIP is approvable as it provides for attainment 

throughout the area and for RFP. Therefore, the requirements of 40 CFR 93.118(e)(4)(v) 

are also satisfied.

EPA is approving and finding adequate the submitted motor vehicle emissions budgets 

for use in transportation conformity determinations because all of the transportation 

conformity rule‘s adequacy criteria have been met and the SIP is approvable as providing 

for attainment throughout the entire nonattainment area and providing for RFP.

Comment: NRDC comments that the approach of ignoring the highway emissions 

violates environmental justice principles. A pervasive example of a current flaw of 

addressing air pollution in environmental justice communities is EPA‘s approach of 

condoning the failure to monitor levels of PM2.5 near highways in the South Coast Air 

Basin.

Response: Executive Order 12898: Federal Actions To Address Environmental Justice in 

Minority Populations and Low-Income Populations Executive Order (EO) 12898 (59 FR 

7629 (Feb. 16, 1994)) establishes federal executive policy on environmental justice. Its 

main provision directs federal agencies, to the greatest extent practicable and permitted 

by law, to make environmental justice part of their mission by identifying and addressing, 

as appropriate, disproportionately high and adverse human health or environmental 
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effects of their programs, policies, and activities on minority populations and low-income 

populations in the United States. 

In reviewing SIP submissions, EPA‘s role is to approve or disapprove state choices, 

based on the criteria of the Clean Air Act, which in this case are found in section 110 and 

part D of title I of the Clean Air Act, and 40 CFR part 51 (particularly, subpart X) of 

EPA‘s regulations and which do not include environmental justice principles as a 

criterion to judge the acceptability of a SIP or SIP revision. Thus, it does not provide 

EPA with the discretionary authority to approve or disapprove a SIP revision based on 

environmental justice considerations.

However, we note that some of the most significant control measures relied upon by the 

South Coast PM2.5 Plan (such as ―cleaner in-use heavy duty trucks‖ – see table 5 of our 

July 14, 2011 proposal) that we are partially approving today anticipate significant 

reductions in emissions from heavy-duty diesel-powered trucks. Such measures, while 

they would contribute to the region-wide goal of attaining the PM2.5 NAAQS, would have 

the greatest emission reduction benefit in the near-highway environment.

Comment: NRDC comments that the attainment demonstration cannot be approved 

because of changes in the inventory. NRDC asserts that EPA‘s new proposal to approve 

the air quality modeling in the 2007 PM2.5 Plan based on the supplemental documentation 

provided by CARB does not address the fundamental problem with the modeling, which 

is that the modeling fails to provide an accurate picture of whether the region will attain, 

and that EPA ―admits that  ̳ideally, new attainment demonstration modeling would be 

performed to evaluate the effect of [the diesel rule updates]...‘‖ NRDC contends that the 

Clean Air Act does not allow EPA to approve inventories it knows to be erroneous 

because new modeling would be too hard. NRDC asserts that EPA must analyze how 

these errors in the base year inventory actually affect the attainment demonstration. 

NRDC claims that EPA attempts to do this by looking at sensitivity modeling submitted 

by CARB, which was meant to determine the ―relative effectiveness‖ on design values of 

additional reductions of NOx and PM2.5 emissions in the attainment year. NRDC asserts 

that EPA claims that the results of this sensitivity modeling support its conclusion that 

new attainment demonstration modeling would be unnecessary. NRDC contends that the 

obvious flaw in EPA‘s reasoning is that it is calculating attainment year design value 

changes, to the hundredth of a percent, from attainment year design values that it has 

already admitted are erroneous. NRDC asserts that EPA cannot justify its failure to 

require updated attainment modeling by back-calculating from the wrong 2014 design 

values to claim that the changes to the inventory would be too small to affect the design 

values. Accordingly, NRDC asserts this approach is arbitrary and capricious.

Response: While some large emission inventory changes might indeed necessitate new 

modeling, EPA does not agree that the inventory changes were large enough to 

substantially affect the modeling conclusions, or to invalidate the attainment 

demonstration. Ideally, new modeling would be performed when an area‘s emission 

inventory is changed. However, since the cost in time and resources of remodeling and 

consequent reworking of a plan is not trivial, administrative necessity requires a 
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judgement call about when changes are large enough to merit new modeling. An 

important criterion in making this judgement is whether the changes would affect the 

conclusion that the plan‘s emission reductions are adequate for attaining the NAAQS. 

Another consideration is the uncertainty inherent in modeling; although model results 

may be reported to several decimal places, model performance goals for fractional bias 

are typically in the range of 30%. (EPA Guidance Appendix B) Small changes in the 

emission inventory are likely to have a small impact on future year design values. This is 

not to discount the importance of an accurate emission inventory, but rather to make the 

point that relatively small changes in inventory estimates do not necessarily invalidate a 

model application. EPA believes that the base year emission decreases due to the 

inventory updates are small enough to leave the overall modeling conclusions unchanged. 

This is a quantitative showing that the emission updates are small enough that they do not 

invalidate the attainment demonstration.

EPA does not agree with NRDC that starting from the Plan‘s modeled design values, and 

ending with small design value changes, constitute flaws in the procedure for estimating 

the effect of the baseline inventory revisions. EPA believes that results derived from 

model sensitivity tests are a reasonable approximation to what would result from new 

modeling with the updated inventory. EPA‘s procedure based on model sensitivity does 

make a number of assumptions; however, the original modeling is basically sound in how 

it portrays South Coast Air Basin‘s atmospheric chemistry and transport. The emission 

changes are small enough that the model response is linear, model sensitivity is similar in 

the starting and ending years, and the spatial and temporal distribution of emissions is 

little changed with the inventory update. EPA believes that these assumptions hold well 

enough that the procedure provides strong evidence for the attainment demonstration‘s 

validity

For regulatory purposes, administrative necessity requires a judgement call about whether 

such problems are substantial enough to compromise regulatory decisions. Years of effort 

by modeling experts from regulatory agencies and academia went into developing the 

South Coast modeling; it underwent successful diagnostic testing; and it performs well. 

EPA believes that it should not be discarded, and that it continues to constitute an 

adequate basis for the attainment demonstration. 

As for the small magnitude of the design value changes resulting from the procedure, 

EPA does not believe this is a substantive issue. Any procedure (even new modeling) that 

starts with small emissions changes will necessarily result in small design value changes: 

within a small range, over which the chemistry does not shift fundamentally, ambient 

concentrations are approximately proportional to emissions. This is not a case of an 

overly precise tiny number being added to a large erroneous random number, but rather 

of an adjustment ratio applied to a number with a lot of solid work behind it. The 

emission inventory update, involving small NOx changes, would also yield relatively 

small design value changes. Of course, this assumes the basic soundness of the original 

modeling, as discussed above. 
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E. RACM/RACT 

Comment: CBE states that EPA should require the SCAQMD to complete a new 

RACM/RACT demonstration including assessment of all available control measures for 

direct emissions of PM2.5 as well as measures for control of secondary PM2.5 resulting 

from NOx, SOx, and VOC emissions. CBE also provides a list of potential pollution

control and energy efficiency measures that it asserts should be included ―as part of a 

new, broader, and complete RACM/RACT assessment to demonstrate attainment 

expeditiously.‖ Finally, CBE asserts that because the South Coast 2007 AQMP is several 

years old, it is important to reassess and update the control measures in the plan, 

especially given the SCAQMD‘s failure to demonstrate attainment. CBE is also opposed 

to what it characterizes as EPA proposed approval of a commitment by CARB to propose 

measures later, as a lump sum.

Response: Section 172(c)(1) of the CAA requires that each attainment plan ―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 shall provide for attainment of the national primary ambient air quality 

standards.‖ For over 30 years, EPA has consistently interpreted this provision to require 

that States adopt only those ―reasonably available‖ measures necessary for expeditious

attainment and to meet RFP requirements. 40 CFR 51.1010; see also 44 FR 20372 (April 

4, 1979) (Part D of title I of the CAA ―does not require that all sources apply RACM if 

less than all RACM will suffice for [RFP] and attainment‖); 57 FR 13498 at 13560 (April 

16, 1992) (―where measures that might in fact be available for implementation in the 

nonattainment area could not be implemented on a schedule that would advance the date 

for attainment in the area, EPA would not consider it reasonable to require 

implementation of such measures‖); ―Guidance on the Reasonably Available Control 

Measures (RACM) Requirement and Attainment Demonstration Submissions for Ozone 

Nonattainment Areas,‖ November 30, 1999 (1999 Seitz Memo) (a State may justify 

rejection of a measure as not ―reasonably available‖ for that area based on technological 

or economic grounds); and 70 FR 71612 (November 29, 2005) at 71661 (noting that 

States ―need adopt measures only if they are both economically and technologically 

feasible and will advance the attainment date or are necessary for RFP‖). EPA‘s 

interpretation of section 172(c)(1) has been upheld by several courts. See, e.g., Sierra 

Club v. EPA, et al., 294 F. 3d 155 (D.C. Cir. 2002); Sierra Club v. EPA, 314 F.3d 735 

(5th Cir. 2002). 

Under the PM2.5 Implementation Rule at 40 CFR 51.1010, a RACM demonstration must 

include ―the list of the potential measures considered by the State, and information and 

analysis sufficient to support the State‘s judgment that it has adopted all RACM, 

including RACT.‖ 40 CFR 51.1010(a). In addition, ―[p]otential measures that are 

reasonably available considering technical and economic feasibility must be adopted as 

RACM if, considered collectively, they would advance the attainment date by one year or 

more.‖ As explained in the preamble to the PM2.5 Implementation Rule, Congress 

provided EPA and States broad discretion to determine what measures to include in an 
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attainment plan, and the language in section 172(c)(1) requiring only ―reasonably 

available‖ measures and implementation of these measures ―as expeditiously as 

practicable‖ indicates that Congress intended for the RACT/RACM requirement to be 

driven by an overall requirement that the measure be ―reasonable.‖ 72 FR 20586 at 

20610 (April 25, 2007). Thus, the rule of ―reason‖ drives the decisions on what controls 

to apply, what should be controlled, by when emissions must be reduced, and finally, the 

rigor required in a State‘s RACT/RACM analysis. See id. States may, as part of a 

RACM analysis, consider the costs of potential control measures and whether the 

measures can be readily and effectively implemented without undue administrative 

burden. See id. (citing 55 FR 38327 and 66 FR 26969).

As discussed in our July 14, 2011 amended proposal, we have evaluated the collection of 

reasonably available control measures that CARB, the District, and the Southern 

California Association of Governments (SCAG) have adopted and submitted with the 

attainment demonstration in the South Coast 2007 AQMP and 2007 State Strategy to 

meet the RACM/RACT requirement in CAA section 172(c)(1) and 40 CFR 51.1010. See

76 FR 41562 at 41568-41572 and TSD at section II.D. For the reasons discussed in our 

amended proposal and as further discussed below, we conclude that the South Coast 2007 

AQMP and the 2007 State Strategy demonstrate that the State has adopted all reasonably 

available control measures (including RACT for stationary sources) necessary to 

demonstrate attainment as expeditiously as practicable and to meet any RFP 

requirements, as required by CAA section 172(c)(1) and 40 CFR 51.1010. Thus, we 

disagree with CBE‘s assertion that the additional measures it has identified are required 

RACM under CAA section 172(c)(1) for purposes of the 1997 PM2.5 NAAQS in the 

South Coast and or that it is necessary to reassess or update the control measures in the 

plan at this time. We explain more specifically below our reasons for concluding that the 

additional control options and energy efficiency measures identified by CBE are not 

required RACM for purposes of attaining the 1997 PM2.5 NAAQS in the South Coast. 

Comment: CBE objects to what it characterizes as CARB‘s ―promise to  ̳propose‘ 

measures later, in a lump sum,‖ and argues that this provides the public with no assurance 

that attainment will be achieved. CBE asserts that individual emission reduction targets 

should be attached to each separate measure and they should be individually required. 

Finally, CBE argues that ―[a]lternative control measures and emissions trading should not 

be allowed, because of deficiencies in the reliability of such programs.‖

Response: We disagree with CBE‘s contention that it is necessary for the State to commit 

to individual measures with specific emission reduction targets for each measure. For the 

reasons discussed in our proposed rule (see 76 FR 41562 at 41575-41577) and further 

below (see responses to comments on ―enforceable commitments‖), we conclude that 

CARB and the SCAQMD have satisfied the criteria that EPA has historically applied in 

approving attainment demonstrations based in part on enforceable commitments in lieu of 

adopted measures. The 2007 State Strategy includes commitments to propose defined 

new measures and an enforceable commitment for emissions reductions sufficient, in 

combination with existing measures and the District‘s commitments, to attain the PM2.5

NAAQS in the South Coast by April 5, 2015. See 76 FR 41562, at 41571 and CARB 
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Resolution 07-28 (September 27, 2007, Attachment B, p. 3). As discussed below in our 

responses to comments on ―enforceable commitments,‖ the 2011 SIP revisions changed 

the total amount of reductions needed from control strategy measures in 2014 to 44 tpd 

of VOC reductions, 129 tpd of NOx reductions, and 41 tpd of SOx reductions (the PM2.5 

enforceable commitment stayed the same at 9 tpd of directly-emitted PM2.5). See July 

2011 TSD, Table F-10. Although CARB‘s commitment provides that it may adopt 

―alternative‖ measures (i.e., measures different from the potential control options 

identified in the South Coast 2007 AQMP or 2007 State Strategy), ultimately the State is 

obligated to achieve these specific aggregate amounts of emission reductions through the 

adoption of enforceable measures no later than the beginning of 2014. See 40 CFR 

51.1007(b) (requiring implementation of all control measures needed for expeditious 

attainment no later than the beginning of the year prior to the attainment date). The 

State‘s commitments to achieve specific amounts of emission reductions by 2014 are 

enforceable by EPA and citizens under CAA sections 113 and 304, respectively. We 

note that CARB has already adopted and submitted to EPA either for SIP-approval or for 

a CAA section 209 waiver most of the measures it had committed to adopt in the 2007 

State Strategy, as revised. See 2011 Progress Report, Appendix B, Table B-1. 

It is unclear what CBE intends by stating that ―alternative control measures and 

emissions trading should not be allowed‖ because of deficiencies in their reliability.

Comment: CBE asserts that the South Coast 2007 AQMP must set Best Available 

Retrofit Control Technology (BARCT) standards for NOx and other PM2.5 precursor 

emissions from industrial boilers and heaters, and that it should require replacement of 

old and severely inefficient equipment at oil refineries and other large sources. CBE also 

asserts that the SCAQMD‘s Regional Clean Air Incentives Market (RECLAIM) program 

does not produce the emission reductions that are achievable from industrial boilers and 

heaters because it allows sources to buy and sell credits. CBE contends that a RACM 

demonstration should include evaluation of each industrial boiler and heater, including its

age, the type of fuel it uses, and its emissions of criteria pollutants, toxics and GHGs. 

Additionally, CBE claims that CARB, as part of its recent Greenhouse Gas (GHG) 

regulatory process under California‘s Assembly Bill 32 (AB32), identified numerous 

methods for increasing energy efficiency, reducing fuel use, and thus reducing emissions 

of criteria pollutants and precursors as well as GHGs statewide, and that EPA should 

require the SCAQMD to carry out the same evaluation for industrial boilers and heaters 

in the South Coast. CBE contends that such energy efficiency measures could also save 

money. Finally, CBE asserts that Ultra-Low NOx burners are cost-effective and must be 

evaluated as part of a RACM analysis for industrial boilers and heaters.

Response: The SCAQMD had adopted two regulations to control NOx emissions from 

industrial boilers, steam generators and process heaters in the South Coast: Rule 1146.1 

(for boilers with rated heat inputs between 2 and 5 MMBtu/hour) and Rule 1146 (for 

boilers with rated heat inputs above 5 MMBtu/hour, with certain exemptions). EPA has 

approved both of these rules into the SIP. See 67 FR 16640 (April 8, 2002) and 60 FR 

46220 (September 6, 1995). EPA recently proposed a limited approval and limited 

disapproval of revisions to these rules that further tighten the NOx emission limits in both 
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rules. See 76 FR 40303 (July 8, 2011).96 As part of that action, we evaluated the 

stringency of the rules‘ control requirements and proposed to conclude that the rules 

together require all control measures that are reasonably available for covered boilers, 

steam generators and process heaters. See id. and associated technical support documents 

(TSDs). We also noted that the NOx emission limits in both rules are equivalent to 

California BARCT standards for these types of boilers, steam generators and process 

heaters. See id. According to the SCAQMD‘s staff report on Rule 1146, most boilers 

subject to the rule will have to use either ultra-low NOx burners or selective catalytic 

reduction (SCR) controls to meet the rule's emission limits, depending on the size of the 

boiler. See Final Staff Report, Proposed Amended Rule 1146 - Emissions of Oxides of 

Nitrogen from Industrial, Institutional, and Commercial Boilers, Steam Generators, and 

Process Heaters, at ES-1. Boilers with rated heat inputs above 40 MMBtu/hour located at 

refineries are subject to the NOx and SOx emission caps in SCAQMD‘s RECLAIM 

program, discussed immediately below. See e-mail dated September 22, 2011, from Ken 

Mangelsdorf (SCAQMD) to Idalia Perez (EPA Region 9), re: ―question about refineries 

and RECLAIM.‖ These adopted measures require all RACM for covered industrial 

boilers, steam generators and process heaters in the South Coast and provide an adequate 

basis for approving the RACM demonstration in the South Coast 2007 AQMP with 

respect to such emission units. We therefore disagree with CBE‘s assertion that the 

SCAQMD is required to evaluate additional control measures for industrial boilers and 

heaters as part of its RACM demonstration for the 1997 PM2.5 standard. 

We also disagree with CBE‘s objections to the inclusion of RECLAIM as a RACM 

measure. RECLAIM is a market incentive program designed to provide sources 

flexibility in complying with emissions limitations. Cap and trade programs, like 

RECLAIM, can take into account emissions control technology by limiting the size of the 

emissions cap. EPA policy provides that a cap and trade program may satisfy RACT by 

ensuring that the level of emission reductions resulting from implementation of the 

program will be equal, in the aggregate, to those reductions expected from the direct 

application of RACT on affected sources within the nonattainment area. See 59 FR 

16690 (April 7, 1994) and "Improving Air Quality with Economic Incentive 

Programs," EPA-452/R-01-001 (January 2001), at Section 16.7. EPA approved the 

RECLAIM program into the California SIP in June 1998 based in part on a conclusion 

that the NOx emission caps in the program satisfied the RACT requirements of CAA 

section 182(b)(2) and (f) for covered NOx emission sources97 in the aggregate. See 61 FR 

57834 (November 8, 1996) and 63 FR 32621 (June 15, 1998). In 2005 and 2010, the 

SCAQMD tightened the NOx and SOx emissions caps in Rule 2002 to address California 

 

96 Our proposed limited disapproval was based on specific deficiencies in the compliance provisions in both 

rules. These enforceability deficiencies do not alter our proposal to conclude that the NOx emission limits 

in the rule, which are more stringent than the SIP-approved version of the rule, represent RACT-level 

controls. See TSDs at page 3. Note, however, that these measures are not eligible for SIP credit until EPA 

approves rule revisions correcting the enforceability deficiencies identified in our proposal. We expect the 

State to submit, as expeditiously as practicable, rule revisions to address these deficiencies consistent with 

its enforceable emission reduction commitments. See 76 FR 41562 at 41569, Table 3. 

97 RECLAIM generally applies to facilities that emit 4 tons or more per year of NOx or SOx in the year 

1990 or subsequent years. See Rule 2001.
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Health and Safety Code requirements for BARCT,98 to require that agricultural sources 

be subject to existing command-and-control regulations instead of RECLAIM, and to 

satisfy a NOx reduction commitment in the 2003 AQMP. See Technical Support 

Document for EPA‘s Rulemaking for the California SIP regarding SCAQMD RECLAIM 

program rules, March 27, 2006, at pp. 5, 6 and Attachment 4. EPA approved the revisions 

to the NOx and SOx emission caps in Rule 2002 on August 29, 2006 and August 12, 

2011 respectively, based in part on conclusions that the revisions continue to satisfy NOx 

RACT requirements. See 71 FR 51120 (August 29, 2006) and 76 FR 50128 (August 12, 

2011). Because RECLAIM achieves reductions of NOx emissions from covered sources 

that are equivalent, in the aggregate, to the reductions achieved by RACT-level controls, 

we conclude that it requires all RACM for covered sources. See 76 FR at 41569, Table 3.

Comment: CBE asserts that emissions of criteria pollutants, toxics, and GHGs could be 

reduced by requiring the SCAQMD to implement the findings of industrial energy use 

audits performed under California‘s AB32 program. Specifically, CBE asserts that the 

SCAQMD could supplement CARB‘s work under AB32 by: (1) requiring 

implementation of potential energy efficiency improvements identified through audits; 

(2) expanding the audit requirements to cover more industrial sources, including certain 

large sources and oil refineries exempted from CARB‘s program; and (3) improving the 

reporting requirements associated with the audits. CBE states that industrial energy 

efficiency assessments not only reduce pollution but also reduce energy costs and should 

be required RACM for purposes of the PM2.5 NAAQS and other standards. CBE 

contends, therefore, that EPA should require the SCAQMD to add such auditing 

requirements to the South Coast 2007 AQMP in strengthened form with emission 

reduction targets.

Response: Although we agree generally that improvements in energy efficiency can 

reduce emissions of criteria and other air pollutants, we disagree with CBE‘s assertion 

that the specific measures associated with energy efficiency that it has identified are 

required RACM for purposes of attaining the 1997 PM2.5 standard in the South Coast. 

Under the PM2.5 Implementation Rule at 40 CFR 51.1010(b), ―[p]otential measures that 

are reasonably available considering technical and economic feasibility must be adopted 

as RACM if, considered collectively, they would advance the attainment date by one year 

or more.‖ CBE asserts only generally that the measures it has identified are reasonably 

available for implementation in the South Coast considering technical and economic 

feasibility, and provides no information to support a conclusion that these additional 

measures would, individually or collectively with other reasonable measures, advance 

attainment of the 1997 PM2.5 standard by at least one year in the South Coast. 

We explained in the preamble to the PM2.5 Implementation Rule (72 FR 20586) that 

although States must conduct a thorough analysis of reasonably available measures, 

States are not required to analyze every conceivable measure to satisfy the RACM 

 

98 BARCT is defined as ―an emission limitation that is based on the maximum degree of reduction 

achievable taking into account environmental, energy, and economic impacts by each class or category of 

source.‖ See California Health and Safety Code, Section 40406.
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requirement in CAA section 172(c)(1). 72 FR at 20612. As long as a State‘s analysis is 

―sufficiently robust in considering potential measures to ensure selection of all 

appropriate RACT and RACM, and the State provides a reasoned justification for its 

analytical approach, we will consider approving that State's RACT/RACM strategy.‖ Id. 

As discussed in our July 14, 2011 amended proposal, CARB, the SCAQMD, and SCAG 

have conducted thorough analyses of all reasonable control measures (including RACT99

for stationary sources) that are available for implementation in the South Coast and 

provided reasoned justifications for the collection of RACM that the State has adopted or 

committed to adopt, based on these analyses. See 76 FR 41562 at 41568, 414572 and 

TSD at section II.D; see also South Coast 2007 AQMP, Appendix VI. CBE‘s comments 

do not change our conclusion that the State has adopted all RACM and RACT necessary 

to demonstrate attainment as expeditiously as practicable and to meet any RFP 

requirements, as required by CAA section 172(c)(1) and 40 CFR 51.1010.

Comment: CBE asserts that SCAQMD ―must implement measures [for additional SOx 

reduction] that were identified in the recent SOx RECLAIM regulation, but not adopted.‖

Response: This comment does not contain sufficient specificity for EPA to respond. 

Comment: CBE asserts that major flaring and smoking episodes occur regularly at 

refineries in the region100 and that the SCAQMD must require that every refinery have a 

flare minimization plan (FMP) consistent with rigorous control methods achieved by two 

specific oil refineries in Martinez, California and Flint Hills, Texas. CBE asserts that 

FMPs are reasonably available measures that could significantly reduce short-term 

emissions of particulates, SOx, NOx, and VOC, although they probably would not 

significantly affect annual emissions levels. CBE states that the SCAQMD‘s flare rule 

requires implementation of an FMP only if emissions exceed certain levels on an annual 

basis, and that the South Coast 2007 AQMP does not adequately account for emissions 

from flaring events, which are episodic. CBE asserts that EPA should require the 

SCAQMD to: (1) model the ambient PM2.5 impacts of large flaring events; (2) revise the 

SCAQMD flare regulation to require that every refinery implement an FMP consistent 

with those at Shell‘s refineries in Martinez, California and Flint Hills, Texas; and (3) add 

a provision to the SCAQMD flare regulation to prohibit all flaring (with certain 

exceptions) unless it is consistent with an approved FMP, as provided in the BAAQMD‘s 

Regulation 12-12-301 (―Flare Minimization‖). CBE contends that such measures are 

technologically and economically feasible and therefore required RACM.

Response: The SCAQMD regulates refinery flares through Rule 1118 (―Control of 

Emissions from Refinery Flares‖), which EPA approved into the SIP on August 28, 2007. 

See 72 FR 49196. Although CBE correctly notes that Rule 1118 requires FMPs only at 

refineries that exceed specific annual emissions thresholds (see Rule 1118 at subsection 

 

99 EPA has defined RACT as the lowest emission limitation that a particular source is capable of meeting 

by the application of control technology that is reasonably available considering technological and 

economic feasibility. 44 FR 53762 (September 17, 1979). 

100 CBE references several sources of SCAQMD data as the basis for its estimates of criteria pollutant 

emissions from these flaring episodes.
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(d)(3) (a) and (e)(1)), CBE appears to misunderstand several other requirements in the 

rule that apply to all petroleum refineries and that are essentially equivalent to the FMP 

requirements in the BAAQMD‘s Rule 12-12. We agree that FMPs are reasonably 

available measures and note that requirements in BAAQMD 12-12 401.1 through 401.3 

are required of all petroleum refineries under SCAQMD Rule 1118 sections (c)(2) and 

(c)(3). For example, BAAQMD 12-12 401.4 requires a description of prevention 

measures addressing specific activities that may cause flaring. SCAQMD‘s Rule 1118 

contains a requirement in section (c)(2)(C) that requires refinery owners to submit to the 

SCAQMD ―descriptions of any equipment, processes or procedures the owner or 

operators plans to install or implement to eliminate or reduce flaring,‖ including the 

scheduled year of installation or implementation. This requirement is essentially 

equivalent to the requirement in BAAQMD Rule 12-12 401.4. Thus, SCAQMD Rule 

1118 contains in sections (c)(2) and (c)(3) requirements that, although separate from the 

requirements for ―flare minimization plans‖ under section (e) of the rule, essentially 

require SCAQMD facilities to submit plans to reduce flaring events similar to those 

required under BAAQMD Rule 12-12. We disagree, therefore, with CBE‘s assertion that 

the SCAQMD is required to adopt additional control requirements for refinery flares and 

conclude that Rule 1118 requires all RACM for these emission sources in the South 

Coast.101

We note that SCAQMD's Board Resolution adopting the District's most recent revisions 

to SCAQMD Rule 1118 directs District staff to evaluate the feasibility of a daily 

emissions target and to evaluate refinements to the annual emissions targets as warranted. 

See SCAQMD Board Resolution 2005-32 (November 4, 2005). Consistent with this 

directive, we encourage the District to reevaluate the control and compliance 

requirements in Rule 1118 as new information about feasible controls becomes available, 

and to adopt any additional control measures that are reasonably available as 

expeditiously as practicable consistent with CAA requirements.

Comment: CBE asserts that methane is a reactive VOC, a smog precursor, and a potent 

GHG, and that EPA should require the SCAQMD to revise its definition of VOC in Rule 

102 to remove the exemption for methane. In support of these assertions, CBE states 

that: (1) a 2002 Harvard University modeling study102 concludes that methane reductions 

could be highly effective in reducing ambient ozone levels; (2) SCAQMD's draft 2007 

AQMP identified significantly larger amounts of Total Organic Gases (TOG) including 

methane from refineries than VOC emissions (10.1 tons per day (tpd) of TOG versus 6 

tpd of VOC); (3) the District should require control of all organic gases from oil 

refineries; and (4) the District should also review its list of other TOG compounds that 

 

101 We note that CBE‘s estimates of emissions from flaring episodes during the 2009-2011 time period are 

consistent with data provided in SCAQMD staff reports submitted to EPA, which show an overall decline 

in emissions from flaring events since 2004. See, e.g., SCAQMD 2005 Staff Report Table IV-2. 

Generally, it is difficult to develop reliable estimates of emissions from flaring events given uncertainties 

about the efficiency of a particular flare event. Flares are devices which burn anything in the stream, and

the contents of the stream may not be completely combusted, causing an unknown composition of 

emissions.

102 Fiore, et al, Harvard University, Linking ozone pollution and climate change: The case for controlling 

methane, 2002. http://www.gfdl.noaa.gov/bibliography/related_files/amf0201.pdf.
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are exempt from regulation. CBE contends that regulation of methane is a reasonably 

available control measure that should be required because additional VOC reductions are 

needed to satisfy RACT/RACM requirements. Finally, CBE claims that the SCAQMD‘s 

exemption for methane makes enforcement difficult for regulators and also ―makes VOC 

control look less cost-effective than it actually is.‖

Response: The SCAQMD‘s definition of VOC in Rule 102 is consistent with EPA‘s 

definition of VOC in 40 CFR 51.100(s), which excludes methane because it has been 

determined to have negligible photochemical reactivity. 40 CFR 51.100(s)(1); see also 

62 FR 44900 (August 25, 1997) (final rule revising definition of VOC to exclude 

methane and other compounds). EPA approved Rule 102 into the SCAQMD portion of 

the California SIP on January 8, 2007. See 72 FR 656. Accordingly, pursuant to its SIPapproved definition of VOC, SCAQMD is not required to regulate methane as a VOC for 

purposes of preparing SIPs to attain the NAAQS. To the extent that CBE intended to 

challenge the exclusion of methane from EPA‘s regulatory definition of VOC at 40 CFR 

51.100(s), such a challenge is outside the scope of today‘s action on the PM2.5 

attainment plan for the South Coast area. Likewise, CBE‘s assertions about the effect of 

methane controls on ambient ozone levels are also outside the scope of today‘s action, 

which addresses the State‘s plan for attaining the 1997 PM2.5 standard. 

As to CBE‘s claims about enforcement difficulties and making VOC control ―look less 

cost-effective than it actually is,‖ these comments do not provide enough specificity for 

EPA to respond.

Comment: CBE asserts that oil refineries, which contribute to power plant emissions by 

using substantial amounts of electricity from the grid, should be required to have backup 

power using clean/alternative energy sources. Specifically, CBE claims that electrical 

grid shutdowns cause power outages at oil refineries, which in turn cause flaring and 

significant amounts of air pollution near the refineries. CBE asserts that the SCAQMD 

should require oil refineries to use alternative energy sources (in place of fossil-fuel 

electricity generation), such as wind and solar energy, and that such measures should be 

required RACM. Based on general information about power plant emissions obtained 

from PG&E, CBE provides its own estimates of the SOx and NOx emission reductions 

that could be achieved if oil refineries were to meet some or all of their electricity 

demands with clean alternative energy sources. CBE contends that the ―large air 

emissions caused by fossil fuel generation at Power Plants due to oil refinery electricity 

demand is worthy of phaseout requirements by the AQMD as a measure in the AQMD.‖ 

Response: Although we generally agree that use of alternative (i.e., non-fossil fuel) 

energy sources to power oil refineries and other large industrial operations would reduce 

emissions of air pollutants, we disagree with CBE‘s generalized assertion that such 

measures are required RACM for purposes of attaining the 1997 PM2.5 NAAQS in the 

South Coast. Section 172(c)(1) of the CAA requires that States adopt measures that are 

―reasonably available‖ and that are necessary to demonstrate attainment as expeditiously 

as practicable and to meet any RFP requirements. 40 CFR 51.1010. As explained above, 

States are required to conduct a thorough analysis of reasonably available measures but 
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are not required to analyze every conceivable measure to satisfy the RACM requirement 

in CAA section 172(c)(1). 72 FR at 20612. 

As discussed in our July 14, 2011 amended proposal, CARB, the SCAQMD, and SCAG 

have conducted thorough analyses of all reasonable control measures that are available 

for implementation in the South Coast and provided reasoned justifications for the 

collection of RACM that the State has adopted or committed to adopt, based on these 

analyses. See 76 FR 41562 at 41568-41572 and TSD at section II.D. Electric generating 

stations and oil refineries in the South Coast are subject to numerous prohibitory rules 

and other control measures that regulate emissions of NOx, SOx, VOC, and PM2.5, 

among other air pollutants, from various emission points within each facility. See, e.g., 

76 FR at 41570, Table 3 and TSD, Appendix B (identifying, e.g., Rule 1105 for 

fluidized-bed coal combustion units (FCCUs) and Rules 1146 and 1146.1 for Industrial, 

Institutional, and Commercial Boilers, Steam Generators, and Process Heaters.) Power 

plants in the district are also subject to RECLAIM. See South Coast Rules 2011 and 

2012. CBE has provided no information to support its general assertion that requiring the 

oil refining industry to obtain electricity (backup electricity or otherwise) from alternative 

energy sources instead of from the electrical grid is a ―reasonably available‖ control 

measure within the meaning of CAA section 172(c)(1). These comments therefore do not 

change our conclusion that the State has adopted all RACM and RACT necessary to 

demonstrate attainment as expeditiously as practicable and to meet any RFP 

requirements, as required by CAA section 172(c)(1) and 40 CFR 51.1010.

Comment: CBE states that the SCAQMD is in the process of developing a regulation to 

control coke drum emissions and that EPA should ensure that this rule is included in the 

District‘s RACM/RACT control strategy. CBE also asserts that this rule has been 

repeatedly delayed due to pressure from the oil industry, and that EPA should ensure that 

the rulemaking occurs expeditiously. CBE asserts that refinery coking operations are 

increasing due to the use of increasingly heavier crude at oil refineries. 

Response: EPA does not currently have reliable information about the types and amounts 

of pollutant emissions from refinery coke drums in the South Coast, and CBE has not 

provided such information to support its assertions. Consequently we cannot conclude at 

this time that any such controls would represent RACT in the South Coast. We note that 

EPA Region 9 staff recently contacted SCAQMD staff to inquire about the status of this 

rule and learned that the District is awaiting information from EPA emission studies to 

inform the District‘s assessment of the feasibility and cost-effectiveness of regulating 

coke drum emissions.103 EPA has sent requests for information about emissions from 

coking operations to several facilities in the South Coast.104 Given the need for additional 

emission reductions in the South Coast to attain the 1997 PM2.5 standard as well as other 

standards for which the area is designated nonattainment (see 40 CFR 81.305), we 

 

103 See record of phone conversation between Nicole Law and Stanley Tong, USEPA Region 9 Air 

Division, and Eugene Teszler, SCAMQD, dated September 14, 2011.

104 See record of phone conversation between Nicole Law, USEPA Region 9 Air Division, and Brenda 

Shine, USEPA OAQPS, dated September 20, 2011.
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encourage the SCAQMD to adopt and implement this rule as expeditiously as practicable 

consistent with CAA requirements.

Comment: CBE states that it had proposed ―requiring 33% RPS for all power plants 

within the SCAQMD‖ and asserts that this is ―clearly achievable‖ since it has been 

adopted as State law.

Response: Assuming CBE intended to assert that the SCAQMD should require all 

investor-owned utilities, electric service providers, and community choice aggregators 

within the South Coast to procure 33 percent of their power from renewable sources by 

2020 as currently required by the State under California‘s Renewable Portfolio Standard 

(RPS), and that such a measure is a required RACM under CAA section 172(c)(1) for 

purposes of attaining the 1997 PM2.5 NAAQS in the South Coast, we disagree. As 

discussed above, section 172(c)(1) of the CAA requires that States adopt measures that 

are ―reasonably available‖ and that are necessary to demonstrate attainment of the 

NAAQS as expeditiously as practicable and to meet any RFP requirements. 40 CFR 

51.1010. CBE has provided no information to support either an assertion that 

California‘s 33% RPS under Senate Bill 2 is such a measure or an assertion that some 

additional RPS to be implemented by the SCAQMD within the South Coast would be 

such a measure. 

Comment: CBE claims that the RACM analysis for locomotive emissions in the South 

Coast 2007 AQMP is deficient because the SCAQMD failed to evaluate reasonably 

available technologies that could reduce locomotive and other railyard emissions. In 

support of this assertion, CBE references two September 2009 public comment letters to 

CARB and an August 2009 CARB document entitled ―Technical Options to Achieve 

Additional Emissions and Risk Reductions from California Locomotives and Railyards.‖ 

Citing Association of American Railroads v. South Coast Air Quality Management 

District, 622 F.3d 1094 (9th Cir. 2010), CBE contends that the Ninth Circuit ―has 

indicated that the SCAQMD and the State of California have the authority to reduce 

emissions from locomotive sources through its determination that [the Interstate 

Commerce Commission Termination Act of 1995] may not preempt some measures 

included in a federally approved SIP.‖ CBE asserts that EPA should therefore direct 

California and the SCAQMD to cure this defect.

Response: We disagree. SCAQMD‘s RACM Demonstration (see appendix VI to the 

2007 South Coast AQMP) does list one type of measure with the potential to reduce 

locomotive and other railyard emissions (locomotive anti-idling) as one of the measures 

the District evaluated as a potential RACM/RACT measure (see table 2 on page VI-11 of 

the 2007 South Coast AQMP, appendix VI). With reference to long duration switch yard 

locomotive idling measures, SCAQMD concluded that ―[I]f there are any additional SIP 

emission reductions that could be accounted for using these innovative technology, they 

would be addressed by CARB during the rule development of their on-road and off-road 

control measures.‖ 2007 South Coast AQMP, appendix VI, page VI-12. This is a 

reasonable conclusion in light of the legal challenge to the District‘s own locomotive 

anti-idling rules (SCAQMD Rules 3501, 3502, and 3503). Moreover, CARB has adopted 
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regulations for mobile cargo handling equipment at ports and intermodal rail yards which 

are designed to use best available control technologies to reduce public exposure to NOx 

and PM. CARB‘s mobile cargo handling equipment rules are the subject of a current 

authorization request to EPA. See 76 FR 5586 (February 1, 2011). 

We note that, while the Ninth Circuit‘s opinion in the Association of American Railroads 

v. South Coast Air Quality Management District case opens the door to District 

regulation of locomotive idling under Federal law by signaling the potential for 

harmonization between such District rules and the Interstate Commerce Commission 

Termination Act of 1995 (ICCTA) if the rules are approved into the SIP, there remains 

uncertainty as to whether the District‘s locomotive anti-idling rules would be within the 

scope of the District‘s state-law regulatory authority. The Ninth Circuit did not decide 

that issue. 622 F.3d at 1096. 

In addition, the documents and court case cited by CBE in support of the idea that there 

are a number of locomotive- and railyard-related measures that may be technologically 

and economically feasible, as well as legally enforceable, all post-date the development 

and submittal of the 2007 South Coast AQMP and 2007 State Strategy. As such, they 

cannot be used to undermine the RACM demonstration for PM2.5 submitted by 

California for the South Coast several years earlier. The cited documents and court case 

may influence the development of control measures for future air quality plans for the 

South Coast, as well as other nonattainment areas, but they do not undermine the RACM 

demonstration in the plan that we are approving in relevant part today. 

For the reasons set forth in the preceding paragraphs, these comments do not change our 

conclusion that the State has adopted all RACM and RACT necessary to demonstrate 

attainment as expeditiously as practicable and to meet any RFP requirements for the 1997 

PM2.5 standard, as required by CAA section 172(c)(1) and 40 CFR 51.1010. See 72 FR 

at 20612 (noting that although States must conduct thorough analyses of reasonably 

available measures, States are not required to analyze every conceivable measure to 

satisfy the RACM requirement in CAA section 172(c)(1)).

Comment: NRDC asserts that the South Coast 2007 AQMD does not satisfy the RACM 

requirement in CAA 172(c)(1) because it fails to identify and require implementation of 

certain reasonably available transportation control measures (TCMs) as expeditiously as 

practicable. NRDC asserts that ―EPA's Transportation Conformity Rule requires that 

TCMs either be listed in section 108(f) of the CAA, or reduce transportation emissions by 

lowering vehicle use or improving traffic flow.‖ Specifically, NRDC asserts that in the 

―illustrative list of TCMs in CAA 108(f), the EPA has acknowledged that improvements 

to bicycle paths and pedestrian walkways are RACM‖ and that the South Coast 2007 

AQMD contains very few TCMs to implement such measures. As an example, NRDC 

claims that little more than 11 percent of the 1996 Los Angeles Bicycle Plan‘s proposed 

bike lanes have been implemented since its development. Finally, NRDC asserts that 

planning agencies have used the TCM process to ―load the SIP with proposed highway 

expansion projects that will purportedly achieve emissions reductions‖ and that several of 
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the plan‘s identified TCMs, such as the SR-47 diesel truck road expansion project, should 

not be included as TCMs because they will not actually reduce emissions.

Response: We disagree with NRDC‘s contention that any of the TCMs it has identified 

are required RACM for purposes of attaining the 1997 PM2.5 standard in the South Coast 

or that the SCAQMD failed to adequately consider reasonably available TCMs as part of 

its RACM analysis. Under 40 CFR 51.1010(b), ―[p]otential measures that are reasonably 

available considering technical and economic feasibility must be adopted as RACM if, 

considered collectively, they would advance the attainment date by one year or more.‖ 

NRDC asserts only generally that the 1996 Los Angeles Bicycle Plan is reasonably 

available for implementation in the South Coast considering technical and economic 

feasibility, and provides no information to support a conclusion that this or any other 

potential TCM would, individually or collectively with other reasonable measures, 

advance attainment of the 1997 PM2.5 standard by at least one year in the South Coast.105 

As discussed in our July 14, 2011 amended proposal, CARB, the SCAQMD, and the 

Southern California Association of Governments (SCAG)106 have conducted thorough 

analyses of all reasonable control measures that are available for implementation in the 

South Coast and provided reasoned justifications for the collection of RACM that the 

State has adopted or committed to adopt, based on these analyses. See 76 FR 41562 at 

41568-41572 and TSD at section II.D. With respect to TCMs in particular, SCAG 

evaluated potential measures identified by public commenters, measures adopted in other 

nonattainment areas, and potential measures identified by EPA. Bicycle projects were 

considered along with many other TCMs as part of the RACM analysis to determine if 

they alone or in combination with other measures would advance the attainment date. See

South Coast 2007 AQMP, Appendix IV-C, p. 36-55. Attachment A to Appendix IV-C of 

the South Coast 2007 AQMP contains a list of the specific TCMs included as part of the 

South Coast 2007 AQMP. The 1996 LA Bicycle Plan is not a part of the approved SIP 

for the South Coast. When an individual bike project has funding for right of way or 

construction in the first two years of the TIP, it is included in TCM-1, SCAG's overall 

TCM program.107 NRDC‘s comments do not change our conclusion that the State has 

adopted all RACM and RACT necessary to demonstrate attainment as expeditiously as 

practicable and to meet any RFP requirements for the 1997 PM2.5 standard, as required 

by CAA section 172(c)(1) and 40 CFR 51.1010. See 72 FR at 20612 (noting that 

although States must conduct thorough analyses of reasonably available measures, States 

 

105 Appendix IV-C to the South Coast 2007 AQMP indicates that implementation of all of the TCMs in 

SCAG‘s Transportation Strategy (including transit and High Occupancy Vehicle (HOV) projects, in 

addition to bicycle and pedestrian projects) is expected to achieve the following total amounts of emission 

reductions: 0.18 tpd of direct PM2.5, 3.48 tpd of NOx, and 1.04 tpd of ROG (VOC). See South Coast 2007 

AQMP, Appendix IV-C at Table 7. Assuming the 1996 Los Angeles Bicycle Plan, if fully implemented, 

would achieve only a fraction of these amounts of emission reductions, it is highly unlikely that this 

measure would advance attainment of the 1997 PM2.5 standard in the South Coast by at least a year. See

Table I-1 in the TSD for a summary of the emission reductions that would achieve one year‘s worth of RFP 

(52.8 tpd of NOx, 30.8 tpd of VOC, 1.1 tpd of PM2.5 and 2.8 tpd of SOx).

106 SCAG is the metropolitan planning organization (MPO) responsible for the transportation strategy and 

transportation control measures in the South Coast nonattainment area.

107 See record of conversation between Wienke Tax, EPA Region 9, and Jonathan Nadler, SCAG, 

September 19, 2011.
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are not required to analyze every conceivable measure to satisfy the RACM requirement 

in CAA section 172(c)(1)). SCAG included a description of the process used to identify 

the potential RACM measures considered. See South Coast 2007 AQMP, Appendix IVC.

We also disagree with NRDC‘s characterization of EPA‘s transportation conformity 

regulations and EPA‘s position with respect to the TMCs identified in CAA section 

108(f). EPA‘s transportation conformity regulations in 40 CFR part 93 establish the 

criteria and procedures for timely implementation of TCMs approved into a SIP, 

including the specific steps and funding sources needed to fully implement each TCM, 

but do not require adoption and implementation of any particular TCM. As to CAA 

section 108(f), we note that following the 1990 CAA Amendments EPA revised its 

previous interpretation of the RACM requirement by eliminating the presumption that all 

TCMs listed in CAA section 108(f) are RACM for all areas. See 57 FR 13598 at 13560 

(April 16, 1992) (stating that ―[l]ocal circumstances relevant to the reasonableness of any 

potential control measure involve practical considerations that cannot be made through a 

national presumption‖ and that States should consider TCMs on an area-specific basis 

and ―consider groups of interacting measures, rather than individual measures‖). Thus, 

States are required to adopt only those TCMs identified in CAA section 108(f) that are 

reasonably available for implementation in the specific nonattainment area. Id. We note 

that EPA cannot require that any measure be listed in section 108(f) of the CAA, as only 

Congress is authorized to amend the CAA. 

Finally, we agree that SR-47 should not be listed as a TCM. We understand from SCAG 

staff that the SR-47 project (Project ID LA0D45) was inadvertently included as a TCM in 

the 2007 SIP in a table labeled ―System Management – Railroad Consolidation 

Programs,‖ on page A-12 of Attachment A of Appendix IV-C of the South Coast 2007 

AQMP. This error has been corrected and this project is no longer listed as a TCM in the 

2008 RTIP.108

Comment: NRDC asserts that the RACM/RACT analysis is deficient because it fails to 

provide any discussion of controls for condensable PM2.5 emissions. NRDC references 

40 CFR 51.1002(c) to support its assertion that ―[t]he transition period allowing agencies 

to ignore controls on condensable emissions expired on January 1, 2011,‖ and also quotes 

EPA‘s statement in the preamble to the PM2.5 Implementation Rule (72 FR at 20652) 

that ―[w]e expect States to address the control of direct PM2.5 emissions, including 

condensables with any new actions taken after January 1, 2011.‖ NRDC states that EPA 

should advise CARB and the District that consideration of reasonably available controls 

on condensable emissions will be required in a revised RACM/RACT submittal.

Response: EPA‘s PM2.5 implementation rule states that ―[a]fter January 1, 2011, for 

purposes of establishing emissions limits under 51.1009 and 51.1010, States must 

establish such limits taking into consideration the condensable fraction of direct PM2.5 

emissions.‖ 40 CFR 51.1002(c). Prior to this date, the rule required that nonattainment 

area SIPs identify and evaluate sources of PM2.5 direct emissions and PM2.5 attainment 

 

108 See electronic mail, Rongsheng Luo, SCAG, to Wienke Tax, US EPA Region 9, August 31, 2011.
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plan precursors as part of the RFP and RACM/RACT demonstrations but did not 

specifically require states to address condensable PM2.5. See id.109 Because the 

attainment, RFP and RACM demonstrations in the South Coast 2007 AQMP and 2007 

State Strategy were adopted on June 1, 2007 and September 27, 2007, respectively, 

California was not required to address condensable PM in establishing the emissions 

limits contained in these demonstrations as originally submitted, or in adopting any other 

PM emission limits under 40 CFR sections 51.1009 and 51.1010 prior to January 1, 2011. 

Consistent with these requirements, EPA has evaluated the reasonable further progress 

(RFP) and reasonably available control measures (RACM) demonstrations in the South 

Coast 2007 AQMP and 2007 State Strategy and concluded that these elements of the Plan 

appropriately address all sources of direct PM2.5 emissions and PM2.5 attainment plan 

precursors (SO2, NOx, and VOC) in the South Coast area. See 76 FR 41562 at 41574.110

The South Coast 2007 AQMP and 2007 State Strategy rely on several rules regulating 

direct PM emissions as part of the PM2.5 control strategy (e.g., Wood Burning Fireplaces 

(Rule 445, adopted March 7, 2008), Wood Stoves and Under-Fired Charbroilers (Rule 

1138, adopted November 14, 1997), and Particulate Matter (PM) Control Devices (Rule 

1155, adopted December 4, 2009)). See 2011 Progress Report, Appendix F, Table 4. 

EPA has not yet acted on any District rule adopted or revised after January 1, 2011 that 

regulates direct PM2.5 emissions. As part of our action on any such rule, we will 

evaluate the emission limits in the rule to ensure that they appropriately address CPM, as 

required by 40 CFR 51.1002(c). 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. See Rule 

1138 paragraph (c)(1) and (g) and SCAQMD Protocol paragraph 3.1.111 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. See Rule 1155 paragraph (e)(6).112 

 

109 See also Letter dated April 25, 2011, from Lisa P. Jackson, EPA, to Paul Cort, EarthJustice, denying 

Petition for Reconsideration with respect to the deferral of the requirement to establish emission limits for 

CPM until January 1, 2011. 

110 In our proposed rule, we noted that the SCAQMD has deferred limits for condensable particulate matter 

(CPM) in its rules but that this limited deferral does not affect the South Coast 2007 AQMP‘s 

RACM/RACT and expeditious attainment demonstrations. 76 FR 41562 at 41566, n. 13. We also noted 

that we would evaluate any PM2.5 rule adopted or revised by the District after January 1, 2011 to assure 

that it appropriately addresses CPM. See id.

111 See SCAQMD Protocol, Determination of Particulate and Volatile Organic Compound Emissions from 

Restaurant Operations, November 14, 1997 (available at 

http://yosemite.epa.gov/R9/R9Testmethod.nsf/0/3D4DEB4D21AB4AAF882570AD005DFF69/$file/SC%2

0Rest%20emiss.pdf).

112 See SCAQMD Test Method 5.1, Determination of Particulate Matter Emissions from Stationary 

Sources Using a Wet Impingement Train, March 1989 (available at http://aqmd.gov/tao/methods/stm/stm005-1.pdf); SCAQMD Test Method 5.2, Determination of Particulate Matter Emissions from Stationary 

Sources Using Heated Probe and Filter, March 1989 (available at http://aqmd.gov/tao/methods/stm/stm005-2.pdf); and SCAQMD Test Method 5.3, Determination of Particulate Matter Emissions from 

Stationary Sources Using an in-Stack Filter, October 2005 (available at 

http://aqmd.gov/tao/methods/stm/stm-005-3.pdf).
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Comment. NRDC asserts that the contingency measures in the South Coast 2007 AQMP 

should be included in the RACM/RACT demonstration.

Response: We disagree. For many of the same reasons that EPA is disapproving the

contingency measures identified in the South Coast 2007 AQMP, many of these 

measures would not be approvable elements of a RACM/RACT demonstration and in any 

case are not required RACM for purposes of the 1997 PM2.5 NAAQS in the South 

Coast. For example, for CTY-01, ―Offsetting the Potential Emission Increase Due to the 

Change in Natural Gas Specifications,‖ the District has provided neither cost 

effectiveness information nor information about the types or amounts of pollutant 

reductions this measure would achieve. Therefore, EPA cannot determine at this time 

whether such a measure is reasonably available considering technical or economic 

feasibility or whether it would contribute to advancing attainment of the 1997 PM2.5 

NAAQS in the South Coast. The District characterizes the measure as an offsetting 

measure for potential increases in emissions, so it is not even clear CTY-01 will provide 

any additional reductions of PM2.5 or PM2.5 plan precursors. See South Coast 2007 

AQMP, Appendix IV-A, page 167. The reductions associated with CTY-02, ―Clean Air 

Act Emission Fees for Major Stationary Sources,‖ do not occur until after 2023, and 

therefore clearly would not contribute to advancing attainment date of the 1997 PM2.5

NAAQS. CTY-03, ―Banning Pre-Tier 3 Off-Road Diesel Engines during High Pollution 

Days,‖ similarly lacks quantification of emissions reductions and cost-effectiveness data. 

As we noted in our July 14, 2011 proposed rulemaking, CTY-04, ―Accelerated 

Implementation of CARB‘s Mobile Source Control Measures,‖ would require additional 

rulemaking at the District level and potentially substantial and lengthy additional 

rulemaking at the State level to be implemented. See 76 FR 41562, at 41579. Therefore, 

we do not believe the reductions could occur in time to advance the attainment date for 

the 1997 PM2.5 NAAQS. In summary, we have concluded that the contingency measures 

in the South Coast 2007 AQMP are not approvable as contingency measures under CAA 

section 172(c)(9) and for many of the same reasons, these measures are not required

RACM for purposes of the 1997 PM2.5 NAAQS. Moreover, NRDC provides no 

information to support a claim that any of these measures would individually or 

collectively advance the attainment date of the South Coast area for the 1997 PM2.5 

NAAQS by at least one year. 40 CFR 51.1010.

F. Comments on State and District Control Measures 

Comment: ARTBA requests that EPA designate this rulemaking as having nationwide 

scope or effect pursuant to CAA section 307(b)(1) based on its belief that certain 

California statewide measures include in-use controls that are inconsistent with section 

209 of the CAA and that are adoptable by states outside not only California but also EPA 

Region IX. ARTBA notes that the D.C. Circuit has never addressed many of the 

preemption issues raised below. Accordingly, ARTBA concludes that the section 

307(b)(1) determination is necessary to ensure nationwide uniformity in the interpretation 

and enforcement of these important CAA preemption issues.
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Response: CAA section 307(b)(1) generally provides that judicial review of EPA action 

in approving a SIP or SIP revision may be filed only in the U.S. Court of Appeals for the 

appropriate circuit. Thus, final EPA actions on revisions to the California SIP, such as the 

South Coast PM2.5 Plan, are generally subject to timely challenges filed in the U.S. Court 

of Appeals for the Ninth Circuit. However, judicial review of an EPA SIP action may be 

filed only in the U.S. Court of Appeals for the District of Columbia if such action is 

based on a determination of nationwide scope or effect and if, in taking such action, the 

EPA finds and publishes that such action is based on such a determination. 

We do not believe that our action approving the South Coast PM2.5 Plan as a revision to 

the California SIP is based on a determination of ―nationwide scope or effect.‖ ARTBA 

does not identify which specific state in-use controls the association is referring to, but 

we assume ARTBA is referring to CARB‘s in-use truck rule and drayage truck rule, 

CARB‘s in-use nonroad equipment rule, and CARB‘s rule regarding ships at port, and 

CARB‘s commercial harbor craft rule (which are referred to in the plan as ―cleaner in-use 

heavy-duty trucks,‖―cleaner in-use off-road equipment (> 25 ph)‖), ―ship auxiliary engine 

cold ironing & clean technology,‖ and ―clean up existing harbor craft.‖). While we 

recognize that the plan relies on these state in-use controls to demonstrate attainment of 

the PM2.5 NAAQS in the South Coast, the specific in-use controls themselves are not the 

subject of today‘s action. In other words, we are not taking action to approve the in-use 

controls as a part of the action we are taking today on the plan, but anticipate final action 

on the in-use controls in other final actions. Moreover, our action today relates to only 

two regions within the state of California, and the provisions reviewed are specific to 

California. Today‘s decision does not affect any other State. Thus, our approval of the 

plan under CAA section 110 is not one of ―nationwide scope or effect.‖ 

With respect to nonroad vehicles and equipment, to the extent section 209(e) is at all 

relevant, other states are free to adopt and enforce California in-use emissions standards 

and other related requirements, but only after EPA has authorized the California 

standards under CAA section 209(e)(2)(A). See CAA section 209(e)(2)(B). EPA is not 

any taking action in this document under section 209(e), and thus the potential 

widespread effect that concerns ARTBA will not occur as a consequence of this 

rulemaking. Moreover, such State action would be a separate action by a separate State 

and would be handled separately. 

With respect to on-road engines and vehicles, California and the other states have the 

same authority, and are subject to the same limitations, in establishing in-use emissions 

standards and other related requirements and thus, even if EPA were to be approving 

California‘s on-road in-use emissions standards in this rulemaking, which it is not, the 

potential for nationwide effect would not occur as a consequence of this rulemaking. 

While any action taken by EPA in one rulemaking may have some precedential effect on 

other actions, this does not make every action taken by EPA an action one of ―nationwide 

scope or effect.‖ This action applies only in California and is relevant only to a particular 

California-specific PM2.5 plan. Therefore, we disagree that today‘s action on the South 

Coast PM2.5 Plan would be of ―nationwide scope or effect.‖
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Comment: ARTBA asserts that the lawfulness of the California and SCAQMD measures 

will hinge on litigation between ARTBA and EPA currently underway in the Ninth 

Circuit, No. 11-71897, and the D.C. Circuit, No. 11-1256, and ARTBA requests that EPA 

stay action on this proceeding pending the resolution of ARTBA‘s litigation. ARTBA 

further requests that, because ARTBA is litigating the nationwide standards under which 

EPA will decide the important preemption issues in this case and because EPA‘s decision 

on California measures would lead to other states‘ adopting (or being compelled to adopt) 

California measures as RFP for their SIPs, EPA stay consideration of nonroad rules 

pending resolution of the ARTBA litigation.

Response: In settlement of a lawsuit seeking to compel EPA action on the 2007 South 

Coast AQMP and related portions of the 2007 State Strategy [Natural Resources Defense 

Council v. EPA, No. 2:10-cv-06029 (C.D. Cal.)], which includes the South Coast PM2.5

Plan, EPA is subject to a consent decree deadline of September 30, 2011 to take final 

action on the South Coast PM2.5 Plan, and thus, any stay of the rulemaking beyond that 

date is not possible. In any event, other than the general preemption issues that ARTBA 

has raised, and that EPA has addressed in various forums, the current lawsuit cited above 

by ARTBA challenges EPA‘s approval of the San Joaquin Valley Unified Air Pollution 

Control District‘s (SJVUAPCD‘s) Rule 9510 [―Indirect Source Review (ISR‖)], which 

turns on an interpretation of CAA section 110(a)(5), which is not germane to EPA‘s 

action on the South Coast PM2.5 Plan.

Comment: ARTBA states that California has adopted a novel series of statewide 

measures that set emission standards and other requirements for in-use on-road and 

nonroad vehicles and fleets of those vehicles. In addition to seeking credit for these 

statewide measures, ARTBA notes that SCAQMD also seeks credit for that district‘s 

local implementation of the Surplus Off-Road Opt-In for NOx (―SOON‖) program under 

which large construction fleets must seek ―SOON‖ funding to acquire clean-thanrequired equipment, with the cost partially deferred by government funds and that the 

South Coast PM2.5 Plan also includes a contingency measure (CTY-03) that would ban 

pre-Tier 3 off-road diesel engines on ―high pollution advisory‖ days. 

ARTBA asserts that all of these measures share the characteristic of setting fleetwide 

standards for CAA-required vehicles that differ from – and are more stringent than – the 

various standards and other requirements that title II of the CAA applies to those 

vehicles, and concludes that the California statewide measures that rely on in-use controls 

or impose in-use fleet measures are preempted. With respect to California‘s in-use 

controls for construction and other diesel-powered equipment, ARTBA believes that 

preemption applies both for equipment above and below the 175–horsepower threshold 

and that the proposed contingency measures (CTY-03) to ban pre-Tier 3 off-road diesel 

engines on ―high pollution advisory‖ days is a preempted in-use standard – particularly 

for equipment under 175 horsepower – for the same reasons. Because these SIP and 

contingency measures are beyond California‘s and SCAQMD‘s authority, ARTBA 

believes that CAA section 110(a)(2)(E)(i) prohibits EPA‘s approving these measures as 

part of the SIP.
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Response: In relevant part, CAA section 110(a)(2)(E) requires SIPs to provide necessary 

assurances that the State will have adequate authority under State law to carry out a SIP 

and is not prohibited by any provision of Federal or State law from carrying out such SIP. 

As a general matter, we agree that States must provide such assurances for SIPs and SIP 

revisions. In the CARB Resolution approving the plan, the State of California provided 

the necessary assurances of adequate legal authority to implement the South Coast PM2.5

Plan. See CARB Resolution 07-41 (September 27, 2007). 

To the extent that ARTBA challenges EPA‘s approval of the South Coast PM2.5 Plan 

based on the plan‘s reliance on the emission standards and other requirements for in-use 

on-road measures, such as CARB‘s truck rule and drayage truck rule, we expect to 

approve the rules into the SIP prior to the effective date of this action, and no comments 

have been received on our proposed approval of the rules [76 FR 40652 (July 11, 2011)] 

that call into question the authority of the State to enforce those rules. To the extent that 

ARTBA challenges EPA‘s approval of the plan based on the plan‘s reliance on standards 

and other preempted requirements for in-use nonroad vehicles, we simply note that EPA 

authorizations under CAA section 209(e) bestow enforceability on the State of California 

as to the emissions standards and other requirements covered by the authorizations, and 

we anticipate EPA action on CARB‘s authorization requests for the in-use nonroad rules 

upon which the plan relies prior to the effective date of today‘s action.113 These rules are 

needed to support emissions reduction credit for certain State measures, including 

―cleaner in-use off-road equipment (> 25 hp),‖ ―ship auxiliary engine cold ironing & 

clean technology,‖ and ―clean up existing harbor craft.‖ See table 5 on page 41571 of the 

July 14, 2011 proposed rule. If the authorizations are issued, there will be no prohibition 

under any Federal law that we are aware of that would prevent California from enforcing 

the related standards and achieving the associated emissions reductions relied upon by the 

plan. If EPA denies CARB‘s authorization requests for the in-use nonroad rules, or if no 

decision is forthcoming, prior to the effective date of today‘s action, we will take 

appropriate remedial action to ensure that our action on the plan is fully supportable or to 

reconsider that action. 

With respect to SCAQMD‘s SOON program, EPA notes that the District implements the 

SOON program through its Rule 2449 (―Control of Oxides of Nitrogen Emissions from 

Off-Road Diesel Vehicles‖), adopted May 2, 2008. SCAQMD Rule 2449 has been 

submitted to EPA for approval into the SIP (submittal date July 18, 2008), but EPA has 

not taken any action on that submittal, nor is EPA taking action on Rule 2449 in 

connection with today‘s action on the South Coast PM2.5 Plan. We recognize that the 

South Coast PM2.5 Plan does take emissions reduction credit for the SOON program, but 

EPA has not allowed the credit in taking action on the plan, and thus the issue of the 

 

113

 The notices of opportunity for public hearing and comment on the relevant requests for authorizations 

were published at 73 FR 58585 (October 7, 2008), 73 FR 67509 (November 14, 2008), and 75 FR 11880 

(March 12, 2010) for CARB‘s in-use nonroad equipment rule; at 76 FR 38153 (June 29, 2011) for CARB‘s 

in-use commercial harbor craft rule; and at 76 FR 38155 (June 29, 2011) for CARB‘s at-berth rule that is 

intended to reduce emissions from auxiliary diesel engines on ocean-going marine vessels at-berth in 

California ports. 
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enforceability of the associated emissions reductions is not germane to our approval of 

the plan.

With respect to the contingency measure referred to as CTY-03, which ARTBA opposes, 

EPA proposed to disapprove the contingency measures, including CTY-03, see 76 FR at 

41579, and is finalizing that proposed disapproval in today‘s document. 

Comment: ARTBA provides a lengthy discussion of the principles of Federal 

preemption in the context of State regulation of emissions from mobile sources under the 

Clean Air Act and its various amendments over time. In so doing, ARTBA identifies a 

number of instances where ARTBA‘s interpretation of the CAA and relevant case history 

differs from that of EPA and offers a number of legal arguments supporting its views.

Response: Except to the extent we have discussed above, ARTBA does not tie this 

discussion of preemption to the SIP action EPA is taking today, namely, final partial 

approval and partial disapproval of the South Coast PM2.5 Plan and related portions of the 

2007 State Strategy. For this reason, and because EPA has addressed ARTBA‘s general 

comments on preemption several times in earlier proceedings, we are not addressing 

those general comments here. 

Comment: AAR asserts that CARB‘s control measure known as ARB-OFRD-02 

anticipates a 90% NOx and PM reduction from the uncontrolled baseline and projects a 

4.3 tons per day (tpd) of NOx emissions reductions in the South Coast by 2014. AAR 

further asserts that, as such, ARB-OFRD-02 is not consistent with the timeframe and 

emission reductions levels contained in EPA‘s regulations for achieving emissions 

reductions from locomotive engines and locomotive fuel.

Response: ARB-OFRD-02 is the identifier used in the 2007 South Coast AQMP to refer 

to the State measure known as ―Accelerated Introduction of Cleaner Locomotives.‖ The 

State‘s measure anticipates that EPA‘s ―tier 4‖ locomotive standards, proposed in 2007 

and promulgated in 2008 (73 FR 25098, May 6, 2008), would likely not provide 

significant additional emissions reductions of NOx and PM from locomotives in the time 

necessary to contribute to attainment of the PM2.5 NAAQS in the South Coast given an 

attainment date of 2015. Thus, the control measure calls for CARB staff ―to work with 

the railroads to bring the cleanest locomotives into California service‖ (Revised Draft 

State Strategy (April 26, 2007), page 114). As noted by AAR, the 2007 State Strategy 

estimates a reduction of NOx of 4.3 tons per day (tpd) in 2014 in the South Coast due to 

this measure. See page 61 of Revised Draft State Strategy (April 26, 2007). However, the 

State Strategy indicates that such estimates are for informational purposes only. CARB 

has not committed to achieving the 4.3 tpd reduction specifically from this measure but 

has committed to aggregate emissions reductions that would be achieved through any 

combination of measures. 

Since adoption of the 2007 State Strategy, CARB staff have been working with 

neighborhood groups, the railroads, and other interested stakeholders to, among other 

things, develop emissions reduction targets at certain rail yards in the South Coast to 
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which the railroads would commit (referred to as the ―2010 Commitments‖). See CARB 

Resolution 10-29 (June 24, 2010). Final approvals of the 2010 Commitments are still 

being negotiated, and there are no plans to submit the 2010 Commitments as a part of the 

SIP; thus, our proposed approval of the attainment demonstration for PM2.5 Plan does not 

rely on any emissions reductions from this control measure (see 76 FR 41562, July 14, 

2011, at 41571, Table 5), nor does today‘s final approval. Therefore, the difference in the 

timing of emissions reductions under ARB-OFRD-02 relative to those expected under 

EPA‘s locomotive regulations does not undermine our approval of the South Coast PM2.5

Plan. 

Comment: CIAQC briefly reviews the state rulemaking process that culminated in 

CARB rules that establish requirements for in-use off-road vehicles and in-use on-road 

diesel-fueled vehicles. CIAQC notes that, through the state rulemaking process, CARB 

modified the underlying data assumptions and modified the applicable rules accordingly. 

CIAQC believes that CARB‘s changes to the rules, while providing some relief, do not 

provide sufficient relief. In particular, CIAQC points to the reduction in resources 

available to the construction industry to meet CARB‘s requirements due to the economic 

downturn in California and asserts that the cumulative economic impact of repowering, 

replacing, retiring, and/or retrofitting offroad equipment and construction trucks is 

beyond what companies can afford, and that this point needs to be considered by EPA. 

CIAQC further requests that EPA review and analyze the compliance methods and 

technologies that are required under the CARB rules to evaluate their viability. CIAQC 

believes that the methods and technologies that are required are untenable or impractical 

and involve installation of add-on diesel technologies that do not work in the field.

Response: CIAQC‘s comments relate to CARB‘s in-use nonroad vehicles and in-use onroad diesel-powered vehicles rules, rather than the South Coast PM2.5 plan, which was the 

subject of EPA‘s proposed action published on July 14, 2011 (76 FR 41562). In today‘s 

final action, we are approving, in relevant part, a plan that relies on emissions reductions 

from these rules, but we are not taking action the rules themselves in this document. In 

any event, in reviewing and acting on state implementation plans (SIPs), it is EPA‘s role 

to determine whether the plan meets the requirements of the CAA and EPA guidance. 

EPA may not disapprove a rule submitted by a state as part of a SIP based on whether the 

requirements in the rule are too costly or may not be economically or technologically 

feasible [see Union Electric Company v. EPA;, 427 U.S. 246, 265 (1976)] so long as the 

rule otherwise meets the minimum requirements of the Clean Air Act. 

G. Comments on Enforceable Commitments 

Comment: California Communities Against Toxics, Communities for a Better 

Environment, Natural Resources Defense Council and Physicians for Social 

Responsibility – Los Angeles (commenters) assert that the South Coast PM2.5 Plan fails 

to include enforceable control measures that meet the requirements of the CAA and that 

EPA cannot rely on ―enforceable commitments‖ as a substitute for adopted control 

measures to ―close the shortfall in the control strategy.‖ Commenters claim that EPA‘s 

action ―breaks with its long-standing interpretation that an attainment SIP must include 
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currently adopted emissions limitations and other control measures‖ that achieve the 

needed emissions reductions. Specifically, commenters state that CAA sections 

110(a)(2)(A) and 172(c)(6) require SIPs to contain ―enforceable emission limitations ... 

as may be necessary or appropriate‖ to achieve attainment. Commenters note that CAA 

section 110(k)(4) allows EPA to grant ―conditional approval‖ of a SIP lacking certain 

statutory elements ―based on a commitment of the state to adopt specific enforceable 

measures‖ by a certain date, and that this provision provides that the conditional approval 

automatically becomes a disapproval if the State fails to comply with the commitment 

within one year. Commenters state that courts have rejected similar attempts to 

circumvent the statute‘s limitations on conditional approvals and cite Sierra Club v. EPA, 

356 F.3d 296, 298(D.C. Cir. 2004) as overturning EPA‘s conditional approval of SIPs 

based in part on the fact that the commitments identified no specific measures the state 

would implement. In further support of their assertions that EPA may not allow States to 

submit ―promises to develop unspecified future enforceable measures as a substitute for‖ 

enforceable control measures, the commenters reference CAA sections 107(a), 110(a)(1), 

110(a)(2)(A), 110(a)(2)(C), the nonattainment plan requirements of part D, title I of the 

Act, EPA regulations in 40 CFR part 51, and EPA‘s General Preamble for the 

Implementation of Title I of the Clean Air Act Amendments (57 FR 13498, 13567 (April 

16, 1992).

Response: As discussed in our amended proposal, the CAA allows approval of 

enforceable commitments that are limited in scope where circumstances warrant the use 

of such commitments in place of adopted control measures. See 76 FR at 41575-41577. 

As pertinent to the comment, Sierra Club involved EPA‘s conditional approval under 

section 110(k)(4) of SIPs lacking in their entirety RACM and ROP demonstrations and 

contingency measures based on letters submitted by states that committed to cure these 

deficiencies. The court rejected EPA‘s construction of section 110(k)(4) as contrary to 

the unambiguous statutory language requiring the state to commit to adopt specific

enforceable measures. Sierra Club at 302. The court found that EPA‘s construction 

turned the section 110(k)(4) conditional approval into a means of circumventing SIP 

deadlines. Id. At 303.

EPA does not dispute the holding of Sierra Club. However that case is not germane to 

EPA‘s approval of CARB‘s and the District‘s commitments here because the Agency is 

not approving those commitments under section 110(k)(4). The relevant precedent is 

instead BCCA. The facts in BCCA were very similar to those presented here. In BCCA, 

EPA approved an enforceable commitment in the Houston ozone SIP to adopt and 

implement unspecified NOx controls on a fixed schedule to achieve aggregate emission 

reductions. Petitioners claimed that EPA lacked authority under the CAA to approve a 

SIP containing an enforceable commitment to adopt unspecified control measures in the 

future. The court disagreed and found that section 110(k)(4) conditional approvals do not 

supplant EPA's practice of fully approving enforceable commitments:

Nothing in the CAA speaks directly to enforceable commitments. The 

CAA does, however, provide EPA with great flexibility in approving SIPs. 

A SIP may contain "enforceable emission limitations and other control 
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measures, means, or techniques . . . as well as schedules and timetables for 

compliance, as may be necessary or appropriate" to meet the CAA's 

requirements.... Thus, according to the plain language of the statute, SIPs 

may contain "means," "techniques" and/or "schedules and timetables for 

compliance" that the EPA considers "appropriate" for attainment so long 

as they are "enforceable." See id. § 7410(a)(2)(A). "Schedules and 

timetables" is broadly defined as "a schedule of required measures 

including an enforceable sequence of actions or operations leading to 

compliance with an emission limitation, prohibition or standard." 42 

U.S.C. § 7602(p). The remaining terms are not defined by the Act. 

Because the statute is silent on the issue of whether enforceable 

commitments are appropriate means, techniques, or schedules for 

attainment, EPA's interpretation allowing limited use of an enforceable 

commitment in the Houston SIP must be upheld if reasonable.

BCCA at 839-840. The court upheld EPA‘s approval of the commitment, finding that 

―EPA reasonably concluded that an enforceable commitment to adopt additional control 

measures on a fixed schedule was an  ̳appropriate‘ means, technique, or schedule or 

timetable for compliance‖ under sections 110(a)(2)(A) and 172(c)(6). Id. at 841. Thus 

the court recognized that sections 110(a)(2)(A) and 172(c)(6) provide a basis for EPA to 

approve enforceable commitments as distinct from the commitments contemplated by 

section 110(k)(4) ), which are not in fact enforceable but instead lead to SIP disapproval 

if not honored. See also Environmental Defense v. EPA, 369 F.3d 193, 209-210 (2nd 

Cir. 2004). (similarly upholding enforceable SIP commitments) As a result, contrary to 

commenters‘ contention, section 110(k)(4) is not a bar to EPA‘s approval of CARB‘s and 

the District‘s enforceable commitments and that approval under section 110(k)(3) is 

permissible as an appropriate means, technique or schedule or timetable for compliance 

under sections 110(a)(2)(A) and 172(c)(6).

Comment: Commenters state that EPA has not determined whether the commitments are 

in fact enforceable. Commenters state that courts ―may only enforce SIP strategies‖ and 

that ―[m]ere approval of an aspirational goal or non-specific promise into the SIP does 

not convert that goal or promise into an enforceable commitment.‖ In support of these 

assertions, commenters cite Bayview Hunters Point Community Advocates v. 

Metropolitan Transp. Comm’n, 366 F.3d 692, 701 (9th Cir. 2004) and Citizens for a 

Better Environment v. Metropolitan Tranp. Comm’n, 746 F. Supp. 976, 980 (N.D.Cal. 

1990) [known as CBE II]. In addition, commenters single out El Comite Para El 

Bienstar de Earlimart v. Warmerdam, 539 F.3d 1062, 1067 (9th Cir. 2008), stating that in 

El Comite the court explained that because an inventory in a SIP is not a ―standard or 

limitation‖ as defined by the CAA, it was not an independently enforceable aspect of the 

SIP. Thus, the commenters reason, in order to be enforceable, not only must a state‘s 

commitment to adopt additional measures to attain emission standards be specific and 

announced in plain language, but any data or rubric that will be used to determine when 

and how the state will adopt those measures must be enforceable. Commenters state that

the commitments in the South Coast SIP are so vague that they cannot possibly be 

enforced against the State and that there is no requirement that the State take any specific 
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actions. The commenters conclude that the commitments cannot be considered 

enforceable under Ninth Circuit case law, because they are not strategies based on 

enforceable emissions standards or limitations.

Response: Under CAA section 110(a)(2)(A), SIPs must include enforceable emission 

limitations and other control measures, means or techniques necessary to meet the 

requirements of the Act, as well as timetables for compliance. Similarly, section 

172(c)(6) provides that nonattainment area SIPs must include enforceable emission 

limitations and such other control measures, means or techniques "as may be necessary or 

appropriate to provide for attainment‖ of the NAAQS by the applicable attainment date.

Control measures, including commitments in SIPs, are enforced directly by EPA under 

CAA section 113 and also through CAA section 304(a) which provides for citizen suits to 

be brought against any person who is alleged ―to be in violation of ... an emission 

standard or limitation....‖ ―Emission standard or limitation‖ is defined in subsection (f) 

of section 304.114 As observed in Conservation Law Foundation, Inc. v. James Busey et 

al., 79 F.3d 1250, 1258 (1st Cir. 1996):

Courts interpreting citizen suit jurisdiction have largely focused on whether the 

particular standard or requirement plaintiffs sought to enforce was sufficiently 

specific. Thus, interpreting citizen suit jurisdiction as limited to claims "for 

violations of specific provisions of the act or specific provisions of an applicable 

implementation plan," the Second Circuit held that suits can be brought to enforce 

specific measures, strategies, or commitments designed to ensure compliance with 

the NAAQS, but not to enforce the NAAQS directly. See, e.g., Wilder, 854 F.2d 

at 613-14. Courts have repeatedly applied this test as the linchpin of citizen suit 

jurisdiction. See, e.g., Coalition Against Columbus Ctr. v. City of New York, 967 

F.2d 764, 769-71 (2d Cir. 1992); Cate v. Transcontinental Gas Pipe Line Corp., 

904 F. Supp. 526, 530-32 (W.D. Va. 1995); Citizens for a Better Env't v. 

Deukmejian, 731 F. Supp. 1448, 1454-59 (N.D. Cal.), modified, 746 F. Supp. 976 

(1990).

Thus courts have found that the citizen suit provision cannot be used to enforce the 

aspirational goal of attaining the NAAQS, but can be used to enforce specific strategies 

to achieve that goal including enforceable commitments to develop future emissions 

controls.

We describe CARB‘s and the District‘s commitments in the 2007 State Strategy (revised 

in 2009 and 2011) and the 2007 AQMP in detail in our proposal and amended proposal 

(75 FR 71294 and 76 FR 41562). The 2007 State Strategy includes commitments to 

propose defined new measures and an enforceable commitment for emissions reductions 

sufficient, in combination with existing measures and the District‘s commitments, to 

attain the PM2.5 NAAQS in the South Coast by April 5, 2015. For the South Coast, the 

State‘s emissions reductions commitments, as submitted in 2007 and revised by the 2009 

State Strategy Update were to achieve 152 tpd NOx, 46 tpd VOC, 9 tpd of direct PM2.5 

 

114

 EPA can also enforce SIP commitments pursuant to CAA section 113.
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and 20 tpd SOx in the South Coast area by 2014. See 76 FR 41562, at 41572; 2009 State 

Strategy Status Report, p. 20.115

The SCAQMD‘s commitments as submitted in 2007 (and revised in 2011) were to 

achieve 10.8 tpd NOx, 10.4 tpd VOC, 2.9 tpd direct PM2.5 and 2.9 tpd SOx by 2014. See 

76 FR 41562, Table 2, at 41569; see also 2011 Progress Report, Appendix F, Table 1, 

and SCAQMD Board Resolution 11-9, March 4, 2011. As discussed above, the 2011 SIP 

revisions revised the State‘s total emissions reduction commitments to 129 tpd of NOx, 

44 tpd of VOC, 9 tpd of PM2.5, and 41 tpd of SOx, which the State remains obligated to 

achieve through the adoption of enforceable measures by 2014. See TSD, Table F-9; see 

also CARB Resolution 07-28, Attachment B at p. 4. 

Thus, CARB‘s commitments are clearly distinguishable from the aspirational goals, i.e., 

the SIP‘s overall objectives, identified by the Bayview court and cited by the commenter. 

CARB‘s commitments here are to adopt and implement measures that will achieve 

specific reductions of NOx, VOC, direct PM2.5 and SOx emissions by 2014. These are 

not mere aspirational goals to ultimately achieve the standards. Rather, the State and 

District have committed to adopt enforceable measures no later than 2014 that will 

achieve these specific amounts of emission reductions prior to the attainment date of 

April 5, 2015. All of these control measures are subject to State and local rulemaking 

procedures and public participation requirements, through which EPA and the public may 

track the State/District‘s progress in achieving the requisite emission reductions. EPA and 

citizens may enforce these commitments under CAA sections 113 and 304(a), 

respectively, should the State/District fail to adopt measures that achieve the requisite 

amounts of emission reductions by the beginning of 2014. See 40 CFR § 51.1007(b) 

(requiring implementation of all control measures needed for expeditious attainment no 

later than the beginning of the year prior to the attainment date). We conclude that these 

enforceable commitments to adopt and implement additional control measures to achieve 

aggregate emission reductions on a fixed schedule are appropriate means, techniques, or 

schedules for compliance under sections 110(a)(2)(A) and 172(c)(6) of the Act.

Commenters cite Bayview as support for their contention that the plan‘s commitments are 

unenforceable aspirational goals. Bayview does not, however, provide any such support. 

That case involved a provision of the 1982 Bay Area 1-hour ozone SIP, known as TCM 

2, which states in pertinent part:

Support post-1983 improvements identified in transit operator‘s 5-year plans, 

after consultation with the operators adopt ridership increase target for 1983-

1987.

EMISSION REDUCTION ESTIMATES: These emission reduction estimates are 

predicated on a 15% ridership increase. The actual target would be determined 

after consultation with the transit operators.

 

115

 We note that in our proposed rule at 76 FR 41562, p. 41571 we reference the 2007 State Strategy, p. 63 

and CARB Resolution 07-28, Attachment B. p.6. Page 63 of the 2007 State Strategy was replaced with the 

information in the 2009 State Strategy Status Report.
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Following a table listing these estimates, TCM 2 provided that ―[r]idership increases 

would come from productivity improvements....‖ 

Ultimately the 15% ridership estimate was adopted by the Metropolitan Transportation 

Commission (MTC), the implementing agency, as the actual target. Plaintiffs 

subsequently attempted to enforce the 15% ridership increase. The court found that the 

15% ridership increase was an unenforceable estimate or goal. In reaching that 

conclusion, the court considered multiple factors, including the plain language of TCM 2 

(e.g., ―[a]greeing to establish a ridership  ̳target‘ is simply not the same as promising to 

attain that target,‖ Bayview at 698); the logic of TCM 2, i.e., the drafters of TCM 2 were 

careful not to characterize any given increase as an obligation because the TCM was 

contingent on a number of factors beyond MTC‘s control, id. at 699; and the fact that 

TCM 2 was an extension of TCM 1 that had as an enforceable strategy the improvement 

of transit services, specifically through productivity improvements in transit operators‘ 

five-year plans, id. at 701. As a result of all of these factors, the Ninth Circuit found that 

TCM 2 clearly designated the productivity improvements as the only enforceable 

strategy. Id. at 703.

The commitments in the 2007 State Strategy (revised in 2009 and 2011) and South Coast 

2007 AQMP are in stark contrast to the ridership target that was deemed unenforceable in 

Bayview. The language in CARB‘s and the District‘s commitments, as stated multiple 

times in multiple documents, is specific; the intent of the commitments is clear; and the 

strategy of adopting measures to achieve the required reductions is completely within 

CARB‘s and the District‘s control. Furthermore, as stated previously, CARB and the 

District identify specific emission reductions that they will achieve, how they could be 

achieved and the time by which these reductions could be achieved, i.e., by 2014.

Commenters also cites CBE II at 980 for the proposition that courts can only enforce 

―express‖ or ―specific‖ strategies. However, as discussed below, there is nothing in the 

CBE cases that supports the commenter‘s view that the CARB and District commitments 

are neither express nor specific. In fact, these cases support our interpretation of CARB‘s 

and the District‘s commitments.

Citizens for a Better Environment v. Deukmejian, 731 F.Supp.1448 (N.D. Cal. 1990), 

known as CBE I, concerned in part contingency measures for the transportation sector in 

the 1982 Bay Area 1-hour ozone SIP. The provision states: ―"If a determination is made 

that RFP is not being met for the transportation sector, MTC will adopt additional TCMs 

within 6 months of the determination. These TCMs will be designed to bring the region 

back within the RFP line." The court found that ―[o]n its face, this language is both 

specific and mandatory.‖ Id. at 1458. In CBE I, CARB and MTC argued that TCM 2 

could not constitute an enforceable strategy because the provision fails to specify exactly 

what TCMs must be adopted. The court rejected this argument, finding that ―[w]e 

discern no principled basis, consistent with the Clean Air Act, for disregarding this 

unequivocal commitment simply because the particulars of the contingency measures are 

not provided. Thus we hold that that the basic commitment to adopt and implement 

additional measures, should the identified conditions occur, constitutes a specific 
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strategy, fully enforceable in a citizens action, although the exact contours of those 

measures are not spelled out.‖ Id. at 1457.116 In concluding that the transportation and 

stationary source contingency provisions were enforceable, the court stated: ―Thus, 

while this Court is not empowered to enforce the Plan's overall objectives [footnote 

omitted; attainment of the NAAQS]--or NAAQS--directly, it can and indeed, must, 

enforce specific strategies committed to in the Plan.‖ Id. at 1454.

Commenters‘ reliance on CBE II is misplaced. It also involves in part the contingency

measures in the 1982 Bay Area Plan. In CBE II, defendants argued that RFP and the 

NAAQS are coincident because, had the plan‘s projections been accurate, then achieving 

RFP would have resulted in attainment of the NAAQS. The court rejected this argument, 

stating that:

the Court would be enforcing the contingency plan, an express strategy for 

attaining NAAQS. Although enforcement of this strategy might possibly result in 

attainment, it is distinct from simply ordering that NAAQS be achieved without 

anchoring that order on any specified strategy. Plainly, the fact that a specified 

strategy might be successful and lead to attainment does not render that strategy 

unenforceable.

(Emphasis in original). CBE II at 980.

CARB‘s commitments here are analogous to the terms of the contingency measures in 

the CBE cases. CARB and the District commit to adopt measures, which are not 

specifically identified, to achieve a specific tonnage of emission reductions. Thus, the 

commitment to a specific tonnage reduction is comparable to a commitment to achieve 

RFP. Similarly, a commitment to achieve a specific amount of emission reductions 

through adoption and implementation of unidentified measures is comparable to the 

commitments to adopt unspecified TCMs and stationary source measures. The key is that 

commitment must be clear in terms of what is required, e.g., a specified amount of 

emission reductions or the achievement of a specified amount of progress (i.e., RFP). 

CARB‘s and the District‘s commitments are thus clearly a specific enforceable strategy 

rather than an unenforceable aspirational goal.

Commenter‘s reliance on El Comite is also misplaced. The plaintiffs in the district court 

attempted to enforce a provision of the 1994 California 1-hour ozone SIP known as the 

Pesticide Element. The Pesticide Element relied on an inventory of pesticide VOC 

emissions to provide the basis to determine whether additional regulatory measures 

would be needed to meet the SIP‘s pesticides emissions target. To this end, the Pesticide 

Element provided that ―CARB will develop a baseline inventory of estimated 1990 

pesticidal VOC emissions based on 1991 pesticide use data....‖ El Comite Para El 

 

116 In this passage, the court was referring specifically to the stationary source contingency measures in the 

Bay Area plan which contained a commitment to adopt such measures if emission targets were not met. 

The Plan identified a number of potential stationary sources but did not commit to any particular one. In 

discussing the transportation contingency measures, the court applied this same reasoning. Id. at 1456-

1457.
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Bienestar de Earlimart v. Helliker, 416 F. Supp. 2d 912, 925 (E.D. Cal. 2006). CARB

subsequently employed a different methodology which it deemed more accurate to 

calculate the baseline inventory. The plaintiffs sought to enforce the commitment to use 

the original methodology, claiming that the calculation of the baseline inventory 

constitutes an ―emission standard or limitation.‖ The district court disagreed:

By its own terms, the baseline identifies emission sources and then quantifies the 

amount of emissions attributed to those sources. As defendants argue, once the 

sources of air pollution are identified, control strategies can then be formulated to 

control emissions entering the air from those sources. From all the above, I must 

conclude that the baseline is not an emission "standard" or "limitation" within the 

meaning of 42 U.S.C. § 7604 (f)(1)-(4).

Id. at 928. In its opinion, the court distinguished Bayview and CBE I, pointing out that in 

those cases ―the measures at issue were designed to reduce emissions.‖ Id.

On appeal, the plaintiffs shifted their argument to claim that the baseline inventory and 

the calculation methodology were necessary elements of the overall enforceable 

commitment to reduce emissions in nonattainment areas. The Ninth Circuit agreed with 

the district court‘s conclusion that the baseline inventory was not an emission standard or 

limitation and rejected plaintiffs‘ arguments attempting ―to transform the baseline 

inventory into an enforceable emission standard or limitation by bootstrapping it to the 

commitment to decide to adopt regulations, if necessary.‖ Id. at 1073.

While commenters cite the Ninth Circuit‘s El Comite opinion, its utility in analyzing the 

CARB and District commitments here is limited to that court‘s agreement with the 

district court‘s conclusion that neither the baseline nor the methodology qualifies as an 

independently enforceable aspect of the SIP. Rather, it is the district court‘s opinion, in 

distinguishing the commitments in CBE and Bayview, that provides insight into the 

situation at issue in our action. As the court recognized, a baseline inventory or the 

methodology used to calculate it, is not a measure to reduce emissions. It instead 

―identifies emission sources and then quantifies the amount of emissions attributed to 

those sources.‖ In contrast, as stated previously, in the 2007 State Strategy (revised 2009 

and 2011) and 2007 AQMP SIP, CARB and the District commits to adopt and implement 

measures sufficient to achieve specified emission reductions by a date certain. As 

described above, a number of courts have found commitments substantially similar to 

CARB‘s here to be enforceable under CAA section 304(a).

Comment: Commenters state that the commitments do not satisfy EPA‘s three-part test 

for enforceable commitments. First, commenters state that EPA admits that the State and 

District have no idea at all how they will achieve the remaining 11% of the NOx, 3% of 

VOC and 8% of PM2.5. Commenters state that this is hardly a ―limited‖ or minimal 

portion of the long-overdue reductions and cite BCCA Appeal Group v. EPA, 355 F.3d 

817, 840-41 (5th Cir. 2003)(commitments for only six percent of the overall reductions). 

Commenters state it is arbitrary and capricious for EPA to conclude that 11% is 

approximately within the 10% range that EPA has historically accepted in approving 
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attainment demonstrations. Commenters believe EPA‘s strategy trivializes the task of 

achieving 70 tpd of reductions over the next 3 years and believes it is even more arbitrary 

given the importance of NOx reductions for attainment.

Response: We disagree with the commenters‘ assertion that CARB and the District do 

not know how they will achieve the remaining reductions needed for attainment in the 

South Coast. As discussed in our amended proposal, the South Coast 2007 AQMD relies 

principally on adopted rules either approved into the SIP or given waivers under CAA 

section 209 to achieve the emissions reductions needed to attain the 1997 PM2.5 standard 

in the South Coast by April 5, 2015, including baseline (pre-2007) measures that continue 

to achieve emission reductions through 2014. 76 FR at 41576. The balance of the 

needed reductions is currently in the form of enforceable commitments that account for 

11% of the NOx, 7% of the VOC and 8% of the PM2.5 emission reductions needed from 

2002 levels to attain. See id.117 These SIP-approved or CAA-waived control measures 

and enforceable commitments satisfy the requirement in CAA section 110(a)(2)(A) to 

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 CAA. See id. at n. 31. 

Although CARB‘s and the District‘s enforceable commitments to additional emission 

reductions are expressed in aggregate tonnages and not tied to specific measures, both 

CARB and the District have provided a list of potential measures that may achieve the 

additional reductions needed to attain the standard, together with expeditious rule 

development, adoption, and implementation schedules consistent with EPA‘s policy on 

acceptable enforceable commitments. See id. at 41576, 41577

We also disagree with the commenters‘ assertions that these remaining amounts are not 

―limited‖ and that it is arbitrary and capricious for EPA to conclude that 11% is 

approximately within the 10% range that EPA has historically accepted as appropriate for

enforceable commitments in approving attainment demonstrations. The State of Texas‘ 

enforceable commitment for the Houston/Galveston area, the approval of which was 

upheld by the Fifth Circuit Court of Appeals in BCCA, represented 6 percent of the 

reductions needed for attainment in the area. We note that the court in BCCA did not 

conclude that any amount greater than 6 percent of the reductions needed would be 

unreasonable. We believe that the 11% of NOx, 7% of VOC and 8% of PM2.5

reductions, as stated in our amended proposal, also fit within the parameters of a 

―limited‖ amount of the reductions needed for attainment and nothing in the BCCA 

decision contravenes that. See also 76 FR 41562 at 41576, n. 34, and footnote 117 

below.

Finally, we disagree with the commenters‘ assertion that EPA‘s strategy ―trivializes‖ the 

task of achieving 70 tpd of NOx reductions over the next three years. As explained in our 

amended proposal, CARB has adopted and submitted a 2009 State Strategy Status Report 

and a 2011 Progress Report, which update and revise the 2007 State Strategy. These 

 

117 The VOC commitment was revised in our final action. See the final rulemaking, section III. ―Approval 

Status of the Control Strategy Measures and Enforceable Emissions Reduction Commitment,‖ and Table F10 above.
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reports show that CARB has made significant progress in meeting its enforceable 

commitments for the South Coast and several other nonattainment areas in California. 

Additional ongoing programs that address locomotives, recreational boats, and other 

measures have yet to be quantified but are expected to reduce NOX and direct PM2.5 

emissions in the South Coast by 2014. See 2011 Progress Report, Appendix E, page 2. 

The District has already exceeded its commitment for reducing VOC and SOx emissions 

and is working to meet the commitment to reduce NOx and directly-emitted PM2.5. See 

Tables 2 and 3. The District is also continuing to work to identify and adopt additional 

measures that will reduce emissions. Beyond the rules discussed above, both CARB and 

the District have well-funded incentive grant programs to reduce emissions from the onand offroad engine fleets. Reductions from several of these programs have yet to be 

quantified and/or credited in the attainment demonstration. Finally, we note that the 

South Coast has experienced significant improvements in its PM2.5 air quality in the past 

few years. 

Given the evidence of the State‘s and District‘s efforts to date and their continuing efforts 

to reduce emissions, we conclude that the State and District are capable of meeting their 

enforceable commitments to achieve the necessary reductions needed to attain the 1997 

PM2.5 standards in the South Coast nonattainment area by April 5, 2015. 

Comment: For the second factor, commenters state that the State has not shown that they 

are capable of achieving its reductions because they have done little more than assert that 

they are committed to meeting the requirements of federal law – but have not included 

any indication of how they will meet the requirements. Commenters assert that given the 

slow progress to date, it seems unlikely that the reductions of the magnitude remaining –

70.5 tpd NOx, 11 tpd VOC and 1.3 tpd PM2.5 – can be achieved without a plan more 

focused and robust than the vague commitment to somehow get the needed reductions. 

Response: We disagree. As explained in our amended proposal, the State‘s and 

District‘s efforts to date and their continuing efforts to reduce emissions (discussed above 

and in our proposed rule), indicate they are capable of meeting their specific enforceable 

commitments to achieve the necessary reductions by 2014. 76 FR 41562 at 41568-

41572 and 41575-41577 and July 2011 TSD at Sections II.D and II.F. 

Comment: Finally, for the third factor, commenters state that it is unclear with the 

changing landscape of many of the measures whether any of these commitments will take 

place within a reasonable and appropriate period of time. Commenters state that EPA 

fails to explain how in the context of an approval in late 2011, the state and air district 

will be able to complete even the requisite rulemaking process, much less actually 

achieve the reductions required by 2014. 

Response: Commenters assume that the only path open to the State to fulfill its 

commitments is the adoption of new measures. We disagree. The list of measures 

provided by CARB in the 2011 Progress Report, Appendix B, Table B-1. represents a 

fraction of the rules and programs adopted and implemented by the State. See TSD 

Appendix A. CARB has not provided, nor has it been required to provide, an evaluation 
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of the effectiveness of its entire control program in reducing emissions in the South Coast 

area. Given that the State has preliminarily demonstrated, based on a limited set of 

measures, that all of the needed SOx reductions, and approximately 90 percent or more of 

the reductions of NOx, VOC, and PM2.5 reductions needed for attainment of the 1997 

PM2.5 standard in the South Coast have already been achieved, we believe it is 

reasonable to conclude that the balance of the needed reductions will also be achieved by 

2014. See 76 FR 41562, p. 41575, Table 7 and September 2011 TSD, Table F-10.

Comment: Commenters assert that although EPA has previously allowed conditional 

approval of SIPs based on ―commitments to complete the adoption of specific 

enforceable measures within a short period of time,‖ EPA has never before allowed a 

five-year extension of the statutory deadline for the submission of control measures yet to 

be specified by the State. 

Response: EPA is not granting a five year extension under section 110(k)(4) of the CAA. 

Rather, EPA is granting California‘s request for an attainment date extension to April 5, 

2015 under CAA section 172(a)(2)(A). We are granting this extension of the attainment 

date for the reasons discussed in our amended proposal. 76 FR 41562 at 41577.

Comment: NRDC asserts that EPA is allowing the South Coast to ―adjust‖ the 2014 

baseline emissions inventory to account for California‘s recent slowdown in economic 

growth. NRDC states that the Act requires that improvements in air quality are the result 

of permanent and enforceable reductions in emissions.

Response: The commenters correctly note that the 2014 baseline emissions inventory in 

the South Coast 2007 AQMP have been adjusted to account for California‘s recent 

slowdown in economic growth. As explained in Section II.B (Emission Inventory) of the 

TSD, however, CARB‘s revisions to the 2014 baseline inventory took into account not 

only updates to the State‘s economic forecasts but also a variety of other factors (out-ofstate VMT estimates, cumulative mileage, equipment populations, load factors, and hours 

of use, etc.) used to calculate emissions from trucks, buses, and certain off-road 

equipment categories. See 2011 Progress Report, Appendix E.

The commenters‘ assertion that the CAA requires improvements in air quality to result 

from permanent and enforceable emissions reductions appears to be based on an incorrect 

understanding of the statutory basis for EPA‘s action. EPA is not determining that 

emission ―reductions‖ related to the economic recession are ―enforceable‖ measures 

under CAA sections 110(a)(2)(A) and 172(c)(6). Section 110(a)(2)(A) of the CAA 

requires that each implementation plan submitted by a State 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 CAA].‖ Section 172(c)(6) contains substantively 

identical requirements for all nonattainment area plans. Baseline emissions inventories, 

however, are not ―enforceable emission limitations and other control measures, means, or 

techniques‖ or ―schedules and timetables for compliance‖ that are necessary or 

appropriate to meet CAA requirements. See El Comite Para El Bienestar de Earlimart v. 

Warmerdam, 539 F.3d 1062 (9th Cir. 2008) (concluding that a baseline inventory is not 

an enforceable ―standard or limitation‖ as defined by the CAA and is not, therefore, an 
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independently enforceable aspect[] of the SIP‖). Rather, base year and baseline 

emissions inventories provide the basis for, among other things, the State‘s development 

of progress milestones and control strategies for attaining the NAAQS consistent with the 

requirements of CAA sections 172(c)(1) and 172(c)(2). See General Preamble at 13503-

13510 (discussing planning inventory requirements for ozone nonattainment areas). In 

short, emissions inventories provide estimates of current and future emissions that, in 

turn, provide the starting point for the State‘s attainment demonstration and enforceable 

control strategy. 

Nothing in the CAA precludes a State from revising a submitted plan to take into account 

revised emissions estimates and growth projections. All projections of future emissionsgenerating activity, including the projections in the South Coast 2007 AQMP as 

originally submitted, are based on projections of population, employment and other 

growth factors, all of which can increase or decrease as economic conditions change.

However, reliance on projections from reputable sources of economic behavior based on 

established methods of predicting such behavior is the historic practice for development 

of emissions inventories. CARB‘s revised projections of future emissions-generating 

activity are based on reputable sources, represent the most current understanding of 

expected economic conditions through at least 2014, and were subject to extensive public 

review and comment before CARB adopted its 2011 SIP revisions containing these 

updated projections. Given the magnitude of the economic recession‘s impact on 

emissions-generating activity in the South Coast and other parts of California, and the 

resulting impact on the State‘s assessment of the control strategy necessary to 

demonstrate attainment of the 1997 PM2.5 standard, we conclude that it is appropriate to 

take these updated emissions projections into account as part of our action on the South 

Coast 2007 AQMP and 2007 State Strategy. Other than asserting generally that CARB 

and EPA should not rely on the revised economic data to determine the reductions needed 

for attainment and that future conditions may change, the commenters provides no 

information to undermine the State‘s revised economic data or the related changes to the 

projected inventories.

For these reasons and as explained in our amended proposal (76 FR 41562, at 41567), we 

are concluding that CARB‘s 2011 SIP revisions, which updated the State‘s projected 

(―baseline‖) emissions inventories based on improved methodologies for estimating 

emissions and more recent growth factors, reduced the total amount of emission 

reductions needed for attainment and that the control strategy in the South Coast 2007 

AQMP and 2007 State Strategy, as revised in 2011, demonstrates expeditious attainment 

of the 1997 PM2.5 NAAQS in the South Coast. 

Comment: The District and CARB commented that they have adopted all feasible 

measures and for areas such as the South Coast, a higher percentage of enforceable 

commitments should be allowed. They argue that 30 percent can be a ―limited‖ amount 

given their circumstances and that EPA‘s 10 percent level is arbitrary. They also argue 

that EPA has not explained why 30% is excessive especially given that the reductions are 

coming from already adopted rules (the in-use off-road equipment and in-use truck rule). 

Finally, they argue that it is illogical for EPA to state that the State/District are capable of 

fulfilling its commitments (i.e., satisfy prong 2) but that the size of the commitments is 

too high to approve and that it is incongruous for EPA to commend the State/District on 
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EPA- Region 9 Page 201

their rulemaking schedules, stating that they are reasonable and appropriate, and then to 

find that they do not meet the appropriate timeframe (i.e., third prong) of the 

commitments criteria.

Response: The question of whether 30 percent constituted a limited amount of 

commitments is now moot given the revised commitment is now in the 10 percent range. 

Also, in our November 2010 proposal, we noted that the commitments did not meet the 

third factor (reasonable and appropriate period of time) because EPA was not proposing 

to extend the attainment date to April 5, 2015. However, as discussed in our July 2011 

amended proposal and further above, we are now approving the attainment demonstration 

and the extension of the attainment date to April 5, 2015, based in part on our conclusion 

that the State and District‘s rule adoption schedules provide sufficient time to achieve by 

2014 the few remaining reductions needed to attain by April 5, 2015. 

Comment: The District comments that there is no requirement that measures must be 

EPA approved before the SIP can be approved. They also comment that it is unfair to 

hold them having approximately 90% of their emissions reductions adopted and approved 

by EPA and compare them to Houston because Houston‘s SIP was approved 7 years after 

it was due to EPA, and South Coast‘s PM2.5 SIP is being acted on approximately 21⁄2 

years after it was due to EPA.

Response: As discussed above, CAA section 110(a)(2)(A) requires that SIPs include 

enforceable emission limitations and other control measures, means or techniques 

necessary to meet the requirements of the Act, as well as timetables for compliance. 

Similarly, section 172(c)(6) provides that nonattainment area SIPs must include 

enforceable emission limitations and such other control measures, means or techniques 

―as may be necessary or appropriate to provide for attainment‖ of the NAAQS by the 

applicable attainment date. The timing of a State‘s submittal or EPA‘s action on that 

submittal does not alter these substantive requirements of the Act. We discussed in 

responses to comments above our reasons for approving the 2007 PM2.5 Plan based in 

part on the limited amount of needed emission reductions that remain as enforceable 

commitments, consistent with EPA‘s past practice. 

H. Comments on Reasonable Further Progress 

Comment: CBE commented that the RFP demonstration is unapprovable due to shortfalls 

in SO2 in 2009 and in NOx and PM2.5 in 2012. 

Response: Under the PM2.5 implementation rule, an RFP plan must demonstrate that in 

each applicable milestone year, emissions will be at a level consistent with generally 

linear progress in reducing emissions between the base year and the attainment year. See 

40 CFR 51.1009(d). The goal of the RFP requirements is for areas to achieve generally 

linear progress toward attainment. The RFP requirements were included in the Clean Air 

Act to assure steady progress toward attaining air quality standards, as opposed to 

deferring implementation of all measures until the end date by which the standard is to be 

attained. 75 FR 20586, at 20633.
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EPA- Region 9 Page 202

As we noted in our July 14, 2011 proposed rulemaking, although the South Coast 

experienced a shortfall of 9 tpd for SOx in 2009, this shortfall is made up by the 

reductions estimated for 2012, and the area meets its 2012 SOx milestone. We note that 

the shortfall in 2012 for NOx is less than 1% of the 2002 baseline inventory, and the 

shortfall in PM2.5 reductions in 2012 is also about 1% of the 2002 baseline inventory, 

while 2012 SOx reduction milestones are met and 2012 VOC reduction milestones are 

exceeded by 20 tpd. (TSD, p. 116) In addition, we noted that we were not evaluating the 

provisions of the updated South Coast 2007 AQMP that address contingency measures 

for failure to meet the 2009 RFP benchmarks. Information available to EPA and the 

public shows that the South Coast met its 2009 RFP benchmarks for 2009 for directlyemitted PM2.5, NOx, and VOC. SOx emissions are higher than the linear benchmark but 

achieve the benchmark levels in 2012 due to recently adopted rules controlling emissions 

of SOx. See 2011 Progress Report, Table C-2 and section II.H of the TSD. Therefore, 

contingency measures for failure to meet the 2009 RFP benchmark no longer have 

meaning or effect under the CAA and therefore do not require any review or action by 

EPA. 

In addition, as noted above, the purpose of RFP contingency measures is to provide 

continued progress while the SIP is being revised to meet a missed RFP milestone. 

Failure to meet the 2009 benchmark would have required California to revise the South 

Coast 2007 AQMP to assure that the next milestone was met and that the plan still 

provided for attainment. California has, in fact, prepared and submitted a revision to the 

South Coast 2007 AQMP that provides for RFP in 2012 and for attainment by 2015. 

(TSD, p. 122) For all of these reasons we conclude that the South Coast 2007 AQMP 

provides for generally linear progress towards attainment, consistent with the 

requirements of CAA section 172(c)(2) and 40 CFR 51.1009. The State has also 

submitted a SIP revision in the form of the 2011 Progress Report to address the missed 

2009 SOx milestone which assures that the 2012 SOx milestone will be met.

I. Comments on Contingency Measures 

Comment: In their January 20, 2011 comment letter, the SCAQMD agrees that the SIP 

must contain contingency measures that should be implemented if the area fails to meet 

the NAAQS by the applicable attainment date. However, the District argues that the 

requirement for these measures to be fully adopted in rule form at time of plan submittal 

is unrealistic.

Response: EPA understands that for some areas the CAA requirement for contingency 

measures is difficult; however, the Act is clear on these requirements. Under CAA 

section 172(c)(9), all PM2.5 attainment plans must include specific contingency measures 

to be implemented if an area fails to meet RFP (RFP contingency measures) and 

contingency measures to be implemented if an area fails to attain the PM2.5 NAAQS by 

the applicable attainment date (attainment contingency measures). These contingency 

measures must be fully adopted rules or control measures that are ready to be 

implemented quickly without significant additional action by the State. 40 CFR § 

51.1012 (―contingency measures must take effect without significant further action by the 
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EPA- Region 9 Page 203

State or EPA‖); see also 57 FR 13498, at 13510-11. They must also be measures not 

relied on in the plan to demonstrate RFP or attainment and should provide SIP-creditable 

emissions reductions equivalent to one year of RFP. Finally, the SIP should contain 

trigger mechanisms for the contingency measures and specify a schedule for their 

implementation. 72 FR 20586, p. 20642. We noted that the purpose of RFP contingency 

measures is to provide continued progress while the SIP is being revised to meet a missed 

RFP milestone. See 76 FR 41562, at 41580. This timely continued progress would not be 

possible if significant additional rulemaking action needed to be taken at the District or 

State level before a measure could be fully adopted and implemented. For the reasons 

provided in both of our proposals, we are disapproving the proposed contingency 

measures in the South Coast 2007 AQMP, which include measures that are not yet fully 

adopted, because they do not meet the requirements for contingency measures in CAA 

section 172(c)(9) and 40 CFR 51.1012. See 76 FR 41562, at 41580.

Comment: In its August 12, 2011 comment letter, the SCAQMD recognizes that the SIP 

must contain contingency measures to be implemented if the area fails to meet the 

NAAQS by the applicable attainment date; however, they again state that they believe the 

requirement to have such measures adopted at the time of plan submittal is unrealistic. 

They point out that under the California Clean Air Act, the SCAQMD is required to 

evaluate all feasible measures in SIP development to achieve the maximum emissions 

reductions possible. Therefore, they believe it is unreasonable to expect that there are 

additional rules that would achieve one year‘s worth of RFP reductions beyond what is 

already adopted. Nevertheless, the SCAQMD outlines a three pronged approach to 

demonstrate that sufficient emissions reductions can be identified to meet the requirement 

for 1-year‘s worth of RFP reductions for contingency measures. The three prongs are (1) 

PM2.5 air quality improvements have significantly exceeded the RFP milestone targets 

by more than one year‘s worth of reductions, (2) relying on continued emissions 

reductions beyond 2014 based on adopted regulations for the 2007 ozone plan, and (3) 

quantifying excess emissions reductions that were not originally included in the 2007 

PM2.5 SIP. The District provides additional detailed information for each of these prongs 

in an attachment to their comments.

Response: EPA understands the unique air quality challenges in the South Coast area and 

appreciates the District‘s efforts to identify additional measures that may serve as 

contingency measures for purposes of the 1997 PM2.5 NAAQS. We note, however, that 

contingency measures should consist of available control measures beyond those required 

to attain the standards, and may go beyond those measures considered to be RACM for 

the area. See 72 FR 20586 at 20643. We commit to work with the State and District to 

identify new or existing control measures and programs not currently included in the 

South Coast 2007 AQMP that may satisfy the CAA section 172(c)(9) requirements for 

contingency measures for purposes of the 1997 PM2.5 NAAQS.

Comment: In both their January 21, 2011 and August 15, 2011 comment letters, NRDC 

supports our proposed disapproval of the contingency measures. NRDC raises two issues 

related to the contingency measures. First, it asserts that the contingency measures lack 

enforceability. Second, it notes that the District does not describe the criteria regarding 
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EPA- Region 9 Page 204

how the monies in the proposed ozone nonattainment fee contingency measure will be 

spent, and does not provide mechanisms for ensuring that emissions reductions are 

enforceable. (We address NRDC‘s third comment about contingency measures in relation 

to RACM in our responses to RACM comments above).

Response: In both our 2010 proposal and our 2011 amended proposal, we proposed to 

disapprove the Plan‘s contingency measure provisions and we are disapproving those 

provisions in today‘s action. See 75 FR 71294, 71311-71312 and 76 FR 41562, 41580. In 

particular, we stated the following: The South Coast 2007 AQMP includes suggestions 

for several measures that do not meet the CAA‘s minimum requirements (e.g., no 

additional rulemaking, surplus to attainment and RFP needs). The AQMP, however, 

indicates that the measures proposed by the District are not adopted, and does not 

quantify the expected emissions reductions in order to gauge whether they provide 

reductions equivalent to one year‘s worth of RFP. For the reasons stated above, we are 

disapproving the District‘s contingency measure provisions in the South Coast 2007 

AQMP for PM2.5. 76 FR 41562, at 415780 (July 14, 2011). 

Regarding NRDC‘s second point, we agree that for CTY-02, ―Clean Air Act Emission 

Fees for Major Stationary Sources,‖ the District does not describe how the monies for the 

CAA nonattainment fees will be spent, nor does it provide mechanisms for ensuring that 

emissions reductions are enforceable. These are among the reasons that we provided for 

disapproving this contingency measure in both our November 2010 and July 2011 

proposed rulemakings. We also noted that the 2007 AQMP does not identify the quantity 

of emissions reductions that the District intended to use to meet the contingency measure 

requirement and therefore, we are unable to determine if the proposed measures are SIP 

creditable or sufficient to provide in combination with other measures the roughly oneyear‘s worth of RFP needed. For these reasons, we determined that the measures 

submitted did not currently meet the CAA requirements for contingency measures. We 

will also continue to work with the District to assure that its incentive programs are 

designed to produce reductions that are surplus, quantifiable, enforceable, and permanent 

in accordance with EPA‘s guidance.

General Comments 

Comment: NRDC commented that the mid-course review is an inappropriate time to 

correct deficiencies. NRDC asserts that EPA‘s regulations set out the MCR as a 

mechanism to provide a check on the plan once an approvable attainment plan is set in 

place. NRDC comments that the long delays in reviewing and approving clean air plans 

in California has resulted in a situation where the mid course review is not used for its 

intended purpose. In the future, NRDC would like to work more closely with EPA to 

ensure that deadlines for actions on major clean air plans happens quickly.

Response: Under the PM2.5 implementation rule at 40 CFR 51.1011, a midcourse review 

must include: (1) A review of emissions reductions and progress made in implementing 

control measures to reduce emissions of direct PM2.5and PM2.5attainment plan precursors 
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EPA- Region 9 Page 205

contributing to PM2.5concentrations in the area; (2) An analysis of changes in ambient air 

quality data for the area; (3) Revised air quality modeling analysis to demonstrate 

attainment; and (4) Any new or revised control measures adopted by the State, as 

necessary to ensure attainment by the attainment date in the approved SIP of the 

nonattainment area. 40 CFR 51.1011(b). 

California‘s 2011 Progress Report contains updated information regarding the South 

Coast area‘s progress toward attaining the 1997 PM2.5 standard, as well as a review of the 

implementation status of control measures in the South Coast 2007 AQMP and the 2007 

State Strategy. Nothing in the CAA or EPA‘s implementing regulations prohibits a State 

from submitting SIP revisions to address deficiencies in a prior SIP submittal, as part of a 

midcourse review or otherwise. We note that we are not determining in this action that 

the South Coast 2007 AQMP and 2007 State Strategy, as revised, satisfy the 

requirements of 40 CFR 51.1011 for purposes of the 1997 PM2.5 NAAQS. We encourage 

NRDC and other public commenters to continue participating in both EPA‘s and the 

State/District‘s rulemaking processes to ensure that plans for attaining the NAAQS are 

developed and implemented in a timely manner consistent with CAA requirements.

Comment: The second NRDC comment on the MCR asserts that ―the proposed rule and 

the TSD rely upon or request significant new information from CARB and SCAQMD,‖

much of which was not provided in any of the documentation. NRDC indicates it will 

provide supplemental comments when those data are available.

Response: This comment does not contain sufficient specificity for EPA to respond.

Comment: SCAQMD contends that the denial of the five-year extension request to 2015 

for the PM2.5 attainment date should not be automatic. SCAQMD concludes that EPA 

should approve the plan fully, and if this is not possible, should approve the plan 

conditionally under Clean Air Act (CAA) section 172(c)(4) based on the commitment in 

the South Coast 2007 AQMP by CARB and the District to adopt enforceable measures to 

achieve emissions reductions to achieve the NAAQS.

Response: The PM2.5 Implementation Rule requires that EPA approve an extended 

attainment date at the time that it approves the attainment demonstration for the relevant 

area, consistent with the attainment date timing provision of CAA section 172(a)(2)(A) 

and 40 CFR 51.1004(a). See 40 CFR 51.1004(b). For the reasons discussed in our July 

2011 amended proposal and further in responses to comments above, EPA is now 

approving both the attainment demonstration in the South Coast 2007 AQMP and 2007 

State Strategy for the South Coast area and the State‘s request to extend the attainment 

date for the area to April 5, 2015. Therefore, SCAQMD‘s comments regarding EPA‘s 

proposed denial of its five-year extension request and the possibility of a conditional 

approval are now moot. 

Comment: The District notes that the 10 tpd federal assignment for NOx emissions has 

been backstopped by the State and District; however, they continue to request EPA‘s 

acceptance of the 10 ton federal assignment especially in light of new NAAQS where 
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EPA- Region 9 Page 206

more cost effective federal sources (in lieu of more costly state and local measures) could 

will allow help the area attain. 

Response: As we stated in our proposals, the CAA does not authorize a State to assign 

responsibility to the Federal government for meeting SIP requirements, and therefore we 

cannot accept the 10 tpd NOx emissions reductions the District and State had assigned to 

the Federal government in the South Coast 2007 AQMP. See 75 FR 71294 at 71309 

(November 22, 2010) and 76 FR 41562 at 41577 (July 14, 2011). In a SIP revision

adopted by CARB on April 28, 2011, and submitted on May 18, 2011, SCAQMD and 

CARB committed to achieve additional emission reductions that would serve as a 

―backstop‖ for the 10 tpd NOx federal assignment. We are approving the State's and 

District's commitments to achieve these additional emissions reductions, which were

previously attributed to the Federal government.

Comment: Robin Hall‘s comment requested that we not add a carbon tax to his state. 

Response: This comment is outside the scope of our action. EPA‘s action on California‘s

plan for attaining the 1997 PM2.5 standard in the South Coast area does not involve a 

carbon tax. 
Appendix A – CARB Rules and Measures
A. Complete List of State Measures

Appendix Table A-1 is a list of all measures adopted by CARB from 1990 until the end 

of 2006. This period covers the 18 years prior to the development of the 2007 State Strategy and 

the South Coast 2007 AQMP. The table should include any substantive rules that would still be 

generating emissions reductions in the South Coast nonattainment area during the 2002-2014 

period covered by the Plan and thus reflected in the baseline for the Plan.

This list does not include the limits on pesticide emissions adopted by the California 

Department of Pesticide Regulation nor the State‘s inspection and maintenance program adopted 

by the California Bureau of Automotive Repair.

Measures that are categorized as Not Applicable are either solely administrative (e.g., 

permit fees, state ambient air quality standards), do not address particulate matter or a PM2.5

attainment plan precursor in the South Coast nonattainment area (e.g., asbestos air toxic control 

measure), or otherwise do not affect emissions in the South Coast nonattainment area (e.g., test 

methods).

Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Antiperspirant/Deodorants. . T 17, CCR, 94500-94506 11/09/89 Consumer products

Transported Pollutants (Ozone). . T 17, CCR, 70500 12/04/89 Not applicable

Emission Control System Warranty. . T 13, CCR, 2035-

2041, 1977 12/14/89 On-road

Non-vehicular Test Methods. . T 17, CCR, 94002, 94003 

17, &26, 94146-94149, 94132, 94135, 94139, 94140 01/11/90 Not applicable

Certification Procedure for Aftermarket Parts. VC 27156 

& 38391 02/08/90 On-road

Airborne Toxic Control Measure for Asbestos in 

Surfacing Applications. . T 17, & 26, CCR, 93106 04/12/90 Not applicable

Test Method for Asbestos in Serpentine Aggregate. . T 

17, & 26, CCR, 94147, Method 435 04/12/90 Not applicable

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, 

CCR, 90700-90704, 93300-93347 05/10/90 Not applicable

Airborne Air Toxic Measure for Ethylene Oxide from 

Sterilizers & Aerators. . T 17, CCR, 93108 05/10/90 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Permit Fee Regulations for Non-vehicular Sources. . T 17, 

CCR, 90800.1, 90800, 90802-90803 05/10/90 Not applicable

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. . T 17, & 26, CCR, 93300-93347 06/14/90 Not applicable

Consumer Products Regulations for the BAAQMD. . T 

17, CCR, 94520-94526 06/14/90 Consumer products

Criteria for Area Designations for the State Ambient Air 

Quality Standard. . T 17, CCR, 70303 & 70304 06/14/90 Not applicable

Emission Standards for Medium Duty Vehicles. . T 13, 

CCR, 1900, 1956.8, 1960.1, 1968.1, 2061, 2112, 2139 06/14/90 On-road

Wintertime Limits for Sulfur in Diesel Fuel. . T 13, CCR, 

2255 06/21/90 Fuels

Dioxins Airborne Toxic Control Measure for Medical 

Waste Incinerators. . T 17, CCR, 93104 07/12/90 Not applicable

Emissions Reduction Accounting Procedures for 

California Clean Air Act. . T 17, CCR, 70700-70704 07/12/90 Not applicable

Identification of Inorganic Arsenic as a Toxic Air 

Contaminant. . T 17, & 26, CCR, 93000 07/12/90 Not applicable

Evaporative Emission Standards. . T 13, CCR, 1976 08/09/90 On-road

Transport Mitigation Regulations. . T 17, CCR, 70600-

70601 08/09/90 Not applicable

Air Toxic Fee Schedule & Emissions Inventory Criteria 

and Guidelines. . T 17, & 26, CCR, 90700-90704, 93300-

93347

09/13/90 Not applicable

California Reformulated Gasoline (CaRFG), Phase I. . T 

13, CCR, 2251.5 09/27/90 Fuels

Low Emission Vehicles and Clean Fuels. . T 13, CCR, 

1900, 1904, 1956.8, 1960.1, 1960.1.5, 1960.5 and 2111, 

2112, 2125, and 2139, 2061.

09/28/90 On-road

Identification of Trichloroethylene as a Toxic Air 

Contaminant. . T 17, & 26, CCR, 93000 10/11/90 Not applicable

Phase I - Consumer Products. . T 17, CCR, 94507-94517 10/11/90 Consumer products
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Controls for Abrasive Blasting. . T 17, CCR, 92000, 

92200, 92400, 98500, 98510, 92520, 92530 11/08/90 Not applicable

Heavy Duty Diesel Smoke Emission Testing. . T 13, 

CCR, 2180-2187 11/08/90 On-road

Revision to Designation Criteria. . T 17, CCR, 60200-

60204, 60208 11/08/90 Not applicable

Identification of Vinyl Chloride as a Toxic Air 

Contaminant. . T 17, & 26, CCR, 93000 11/13/90 Not applicable

Conflict of Interest Code. . T 17, CCR, 95001, et. seq. 12/13/90 Not applicable

Emission Standards for Utility and Lawn and Garden 

Engines. . T 17, CCR, 2400 et. seq. 12/13/90 Off-road

Identification of Chloroform as a Toxic Air Contaminant. 

. T 17, & 26, CCR, 93000 12/13/90 Not applicable

Limit on Aromatic Content of Diesel Fuel. . T 13, CCR, 

2256 12/13/90 Fuels

Permit Fee Regulations for Non-vehicular Sources. . T 17, 

CCR, 90800.2, 90801, 90803 02/24/91 Not applicable

Acid Deposition Fee Regulations. . T 17, CCR, 90621.2, 

90620, 90622 04/11/91 Not applicable

Non -Vehicular Test Methods. . T 17, CCR, 94131, 

94132, 94142 04/11/91 Not applicable

Administrative Hearing Procedures. . T 17, CCR, 

60075.1, 60075.47 05/09/91 Not applicable

Air Toxics "Hot Spots" Fee Regulation. . T 17, & 26, 

CCR, 90700 - 90705 06/13/91 Not applicable

Agricultural Burning Guidelines. T 17, 80130, 80150, 

80250, 80260, 80290 07/11/91 Not applicable

Identification of Metallic & Inorganic Nickel Compounds 

as a Toxic Air Contaminant. T 17, & 26, 93000 08/08/91 Not applicable

Onboard Diagnostics for Light-Duty Trucks and Light & 

Medium-Duty Motor Vehicles. T 13, CCR, 1977, 1968.1 09/12/91 On-road

Identification of Perchloroethylene as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 10/10/91 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

State Ambient Air Quality Standard for SO2. T 17, CCR, 

70100, 70200, 70201 10/10/91 Not applicable

Onboard Diagnostic, Phase II. T 13, CCR, 1968.1, 1977 11/12/91 On-road

Area Designations. T 17, CCR, 60200, 60209 11/14/91 Not applicable

Low Emission Vehicles amendments revising reactivity 

adjustment factor (RAF) provisions and adopting a RAF 

for M85 transitional low emission vehicles. T 13, CCR, 

1960.1

11/14/91 On-road

California Reformulated Gasoline, Phase II. T 13, CCR, 

2250, 2255.1, 2252, 2260 - 2272, 2295 11/21/91 Fuels

Wintertime Gasoline Program. T 13, CCR, 2258, 2298, 

2251.5, 2296 11/21/91 Fuels

Specifications for Alternative Motor Vehicle Fuel. T 13, 

& 26, CCR, 2290, 2291, 2292.1, 2292.2, 2292.3, 2292.5, 

2292.6, 2292.7, 1960.1(k), 1956.8(b), 1956.8(d)

12/12/91 Fuels

Heavy Duty Diesel Cycle Engines. T 13, CCR, 2420-2427 01/09/92 Off-road

Phase II - Consumer Products. T 17, CCR, 94501, 94502, 

94505, 94514, 94503.5, 94506, 94507 - 94513, 94515 01/09/92 Consumer products

Identification of Formaldehyde as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 03/12/92 Not applicable

Specifications for Alternative Motor Vehicle Fuels. T 13, 

& 26, CCR, 2290-2292.7, 1960.1(k), 1956.8(b), 1956.8(d) 03/12/92 On-road

Atmospheric Acidity Protection Fees. T 17, CCR, 

90621.3 04/09/92 Not applicable

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.3, 90803 04/09/92 Not applicable

Criteria for Area Designations. T 17, CCR, 70303, 70304 05/14/92 Not applicable

Standards and Test Procedures for Alternative Fuel 

Retrofit Systems. T 13, CCR, 2030, 2031 05/14/92 On-road

Transported Air Pollutants. T 17, CCR, 70500 05/28/92 Not applicable

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90701, 90704, 90705 07/09/92 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Identification of 1.3 Butadiene as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 07/09/92 Not applicable

Phase 2 RFG certification fuel specifications. T 13, CCR, 

1960.1, 1956.8(d) 08/13/92 On-road

CFC Refrigerants in Air Conditioning Systems. T 13, 

CCR, 2500 09/10/92 Not applicable

Substitute Fuel or Clean Fuel Incorporated Test 

Procedures. T 13, CCR, 1960.1(k), 2317 11/12/92 On-road

Notice of General Public Interest for Consumer Products. 

T 17, CCR, 94507 - 94517 11/30/92 Consumer products

Airborne Toxic Control Measure for Emission of Toxic 

Metals from Non-Ferrous Metal Melting. T 17, & 26, 

CCR, 93107

12/10/92 Not applicable

Criteria for Area Designations. T 17, CCR, 70303.5, 

60200-60203, 60205, 70303 12/10/92 Not applicable

Smoke Self Inspection Program for Heavy Duty Diesel & 

Gasoline Engines. T 13, CCR, 2190-2194, 2180-2187, 

1956.8(b)

12/10/92 On-road

Certification Requirements for Low Emission Passenger 

Cars, Light-Duty Trucks & Medium Duty Vehicles. T 13, 

CCR, 1960.1, 1976, 2061, 1900

01/14/93 On-road

Transport Mitigation Regulations. T 17, CCR, 70600, 

70601 03/11/93 Not applicable

1-year Implementation Delay in Emission Standards for 

Utility Engines. T 13, CCR, 2400, 2403-2407 04/08/93 Off-road

Acid Deposition Fee Regulations. T 17, CCR, 90622, 

90621.4 04/08/93 Not applicable

Identification of Federal Hazardous Air Pollutants as 

Toxic Air Contaminants. T 17, & 26, CCR, 93001, 39665, 

39666

04/08/93 Not applicable

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.4, 90803 04/08/93 Not applicable

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. T 17, & 26, CCR, 93300-93347 06/10/93 Not applicable

Urban Transit Buses. T 13, CCR, 1956.8, 1965, 2112 06/10/93 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700-90705 07/08/93 Not applicable

Onboard Diagnostic, Phase II. T 13, CCR, 1968.1 07/09/93 On-road

Mitigation Transport Pollutants. T 17, CCR, 70500, 

70600 08/12/93 Not applicable

Wintertime Oxygenate Program. T 13, CCR, 2258, 

2251.5, 2263(b), 2267, 2298, 2259, 2283, 2293.5 09/09/93 Fuels

Airborne Toxic Control Measure for Perchloroethylene 

Dry Cleaning. T 17, & 26, CCR, 93109, 93110 10/14/93 Not applicable

Diesel Fuel Regulations - Emergency. T 13, CCR, 

2281(h), 2282(1) 10/15/93 Fuels

Conflict of Interest. T 17, CCR, 90500 11/18/93 Not applicable

Criteria for Area Designations. T 17, CCR, 60200-60202, 

60204, 60206, 60208, 70300-70306 11/18/93 Not applicable

Off-Highway Recreational Vehicles. T 13, CCR, 2410-

2414, 2111-2140 01/03/94 Off-road

Evaporative Emission Standards and Test Procedures. T 

13, CCR, 1976 02/10/94 On-road

SCAQMD's Reclaim Consideration 03/10/94 Stationary Sources

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.5, 90803 04/14/94 Not applicable

Predictive Model for Phase II CaRFG. T 13, CCR, 2261, 

2262-2270 06/09/94 Fuels

Small Refiner Diesel. T 13, CCR, 2282(e)(1) 07/24/94 Fuels

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700-90705 07/28/94 Not applicable

Utility and Lawn and Garden Equipment Engines. T 13, 

CCR, 2403(c), 11(a)(1)(I)(ii), 4(a)(1)(I)(ii) 07/28/94 Off-road

Alternative Control Plan for Consumer Products. T 17, 

CCR, 94540-94555 09/22/94 Consumer products

Diesel Fuel Certification. T 13, CCR, 1956.8(b)&(d), 

1960.1(k), 2292.6 09/22/94 Fuels

Area Designations. T 17, CCR, 60201, 60204 11/09/94 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Self Inspection Program for Heavy Duty Diesel & 

Gasoline Engines. T 13, CCR, 2190-2194, 2180-2187, 

1956.8(b)

11/09/94 On-road

Onboard Diagnostics, Phase II. T 13, CCR,1963.1, & 

Certification Procedures 12/08/94 On-road

Periodic Smoke Inspection Program. T 13, CCR, 2190 12/08/94 On-road

Specification for Alternative Motor Vehicle Fuels 

(M100). T 13 CCR, 2292.1 12/08/94 Fuels

Aerosol Coating Products and Alternative Control Plan. T 

17, CCR, 94520-94528, 94540-94543, 94547... 03/23/95 Consumer products

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.6, 90803 04/27/95 Not applicable

Employee-Based Trip Reductions Emission Formula. T 

13, CCR, 2330, 2331, 2332 06/29/95 Not applicable

Gasoline Vapor Recovery Systems. T 17, CCR, 94010-

94015, 94150-94160, 94000-94004, 94007. 06/29/95 Vapor Recovery

Heavy Duty Vehicle Exhaust Emission Standards. T 13, 

CCR, 1956.8 and incorporate test procedures. 06/29/95 On-road

Onboard Refueling Vapor Recovery Standards. T 13, 

CCR, 1976, 1978 and incorporate test procedures 06/29/95 On-road

Test Method for Oxygen in Gasoline. T 13, CCR, 

2251.5(c), 2258(c), 2263(b) 06/29/95 Fuels

Retrofit Emission Standards. T 13, CCR, 1956.9, 2030, 

2031, and incorporate test procedures 07/27/95 On-road

Antiperspirants and Deodorants, Consumer Products, and 

Aerosol Coating Products. T 17, CCR, 94500-94506, 

94508, 94521

09/28/95 Consumer products

Low Emission Vehicle Standards 3 (LEV 3). T 13, CCR, 

1956.8, 1960.1, 1965, 2101, 2061, 2062, and incorporate 

test procedures

09/28/95 On-road

Test Methods for CaRFG 13, CCR, 2263(b) 10/26/95 Fuels
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Required Additives in Gasoline (Deposit Control 

Additives). T 13, CCR, 2257 and incorporates testing 

procedures.

11/16/95 Fuels

CaRFG Housekeeping & CARBOB. T 13, CCR, 2263.7, 

2266.5, 2260, 2262.5, 2264, 2265, 2272 12/14/95 Fuels

Exemption of Military Tactical Vehicles. T 13, CCR, 

1905, 2400, 2420 12/14/95 On Road/Off Road

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90700-90705 and Appendix A 01/25/96 Not applicable

CaRFG Variance Requirements. T 13, CCR, 2271 

(Emergency) 01/25/96 Fuels

Relaxation of Carbon Monoxide Emission Standards for 

Utility Engines. T 13, CCR, 2403 and incorporating test 

procedures

01/25/96 Off-road

Postpone Zero Emission Vehicle Requirements. T 13, 

CCR, 1900, 1960.1, 1976 03/28/96 On-road

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90803, 90800.7 04/25/96 Not applicable

Basin Boundaries for Agricultural Burning (Mojave 

Desert, South Coast & Salton Sea). T 17, CCR, 60104, 

60109, 60114, 80280, 80311

05/30/96 Not applicable

Regulation Improvement and Repeal. T 17, CCR, 93301-

93355, Appendix A-E (emissions inventory) 05/30/96 Not applicable

Regulation Improvements and Repeals (fuel additives). T 

13, CCR, 2201, 2202 05/30/96 Fuels

Emissions Inventory Criteria & Guideline Report. T 17, 

CCR, 93300.5 07/25/96 Not applicable

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90701-90705 Appendix A to §§ 90700-90705 09/26/96 Not applicable

Stationary Source Test Methods. T 17, CCR, 94105, 

94107, 94114, 94135, 94141, 94143, 94161 09/26/96 Not applicable

Wintertime Requirements for Utility Engines & OffHighway Vehicles. T 13, CCR, 2403 09/26/96 Off-road

Diesel Fuel Certification Test Methods . T 13, CCR, 

1956.8(b), 1960.1(k), 2281(c), 2282(b), (c) and (g) 10/24/96 Fuels

Diesel Fuel Test Methods. T 13, CCR, 1956.8(b), 

1960.1(k), 2281(c), 2282(b), (c) and (g) 10/24/96 Fuels
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Antiperspirants and Deodorants, Consumer Products, 

Aerosol Coating Products (ARB Test Method 310). T 17, 

CCR, 94506(a), 94515(a), 94526

11/21/96 Consumer products

Area Designations. T 17, CCR, 60201-60209 11/21/96 Not applicable

Consumer Products and Aerosol Coating Products 

Amendments. T 17, CCR, 94508-94515, 99517, 94321 11/21/96 Consumer products

Transport Pollutants. T 17, CCR, 70500, 70600 11/21/96 Not applicable

Onboard Diagnostics, Phase II, Technical Status. T 13, 

CCR, 1968.1, 2030, 2031 12/12/96 On-road

Consumer Products (Hair Spray) Amendments. T 17, 

CCR, 94509, 94513, 94514 03/27/97 Consumer products

Liquefied Petroleum Gas Propane Limit Specification 

Delay. T 13, CCR, 2292.6 03/27/97 Fuels

Portable Equipment Registration Program. T 13, CCR, 

2450-2465 03/27/97 Off-road

Identification of Inorganic Lead as Toxic Air 

Contaminant (TAC). T 17, CCR, 93000 04/24/97 Not applicable

Interchangeable Emissions Reduction Credits. T 17, CCR, 

91500 05/22/97 Not applicable

Postpone Enhanced Evaporative Emission Requirements 

for Ultra-Small Volume Vehicle Manufacturers. T 13, 

CCR, 1976 and incorporate test procedures

05/22/97 On-road

Consumer Products (Mid-Term Measures) Amendments. 

T 17, CCR, 94508, 94509, 94513 07/24/97 Consumer products

Off-Cycle Emissions Supplemental Federal Test 

Procedures (SFTPs). T 13, CCR, 1960.1, 2101 and 

incorporate test procedures

07/24/97 On-road

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR 

90701-90705 and Appendix A 11/13/97 Not applicable

Area Designations. T 17, CCR, 60201 & 60205 11/13/97 Not applicable

Consumer Products (Hairspray Credit Program). T 17, 

CCR, 94502, 94509, 94522, & 94548 11/13/97 Consumer products

Heavy Duty Vehicle Smoke Inspection Program/Periodic 

Smoke Inspection Program. T 13, CCR, 2180-2188 and 

2190-2194

12/11/97 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Permit Fee Regulations for Non-vehicular Sources. T 

17,CCR 90800.... 01/29/98 Not applicable

Small Off-Road Engines (SORE). T 13, CCR, 2400,2410-

2414 03/26/98 Off-road

Classifying Minor Violations. T 17, CCR, 60090-60095 04/23/98 Not applicable

Heavy Duty Vehicle Regulations: 2004 Standards. T 13, 

CCR, 1956.8, 1965, 2036, 2112 and test procedures 04/23/98 On-road

Airborne Toxic Control Measure for Chrome Plating. T

17, CCR, 93102 05/21/98 Not applicable

Cleaner Burning Gasoline Model Flexibility. T 13, CCR, 

Sections 2260, 2262.1, 2262.3, 2262.4, 2262.5, 2262.6, 

2262.7 and 2265

08/27/98 Fuels

Gasoline Vapor Recovery Systems. T 17, CCR, 94010-

94015 and 94150, 94156, 94157, 94158, 94159, 94160, 

94162

08/27/98 Vapor Recovery

Identification of Diesel Exhaust as a Toxic Air 

Contaminant. T 17, CCR, 93000 08/27/98 Not applicable

Gasoline Deposit Control Additive Regulation. T 13, 

CCR, 2257, and incorporating test procedures 09/24/98 Fuels

Air Toxics ―Hot Spots‖ Fee Regulations. T 17, CCR, 

90701-90705 and Appendix A 10/22/98 Not applicable

Area Designations and Criteria for the National and State 

Ambient Air Quality Standards for Ozone. T 17, CCR,

60301, 60202, 60205, 60206, 70300-70306, 70303.1

10/22/98 Not applicable

Large Off-Road Spark-Ignition Engine Regulations. T 13, 

CCR, 2430 et seq., and 2411-2414 10/22/98 Off-road

Stationary Source Test Methods. T 17, CCR, 94101 -

94104, 94106, 94108 - 94113, 941T 17 - 94124, 94137 

and revision of Method 12.

10/22/98 Not applicable

Low Emission Vehicles Standards (LEV 2) and 

Compliance Assurance Program (CAP 2000). T 13, 

CCR,1961 & 1962 (both new); 1900, 1960.1, 1965,

1968.1, 1976, 1978, 2037, 2038, 2062, 2101, 2106, 2107, 

2110, 2112, 2114, 2119, 2130, 2137-2140, 2143-2148

11/05/98 On-road

Aftermarket Parts for Off-Road Engines. T 13, CCR, 

2470-2476 11/19/98 Off-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Consumer Products - LVP-VOC Definitions And Test 

Methods. T 17, CCR, 94506, 94506.5, 94508(a)(78), 

94515 and 94526, and the amendment of ARB Method 

310

11/19/98 Consumer products

Consumer Products, Aerosol Coatings & Antiperspirants 

and Deodorants. T 17, CCR, 94501, 94508, 94521, 94522, 

and 94524

11/19/98 Consumer products

1997 & Later Model Off-Highway Recreational Vehicles 

and Engines. T 13, CCR, 2410-2414, 2415 12/10/98 Off-road

Emission Standards and Test Procedures for 2001 Marine 

Engines. T 13, CCR, 2440 et seq 12/10/98 Off-road

Exhaust Standards for (On-Road) Motorcycles. T 13, 

CCR, 1958 12/10/98 On-road

Revisions to Statewide Portable Equipment Registration 

Program. T 13, CCR, 2450-2463 12/10/98 Off-road

Voluntary Accelerated Light Duty Vehicle Retirement 

Regulations. T 13, CCR, 2600-2610 12/10/98 On-road

Cleaner Burning Gasoline (Increasing the Oxygen 

Content). T 13, CCR, sections 2262.5(b) and 2265(a)(2) 12/11/98 Fuels

Specifications for Liquid Petroleum Gas Used as a Motor 

Vehicle Fuel. T 13, CCR, 2292.6 12/11/98 Fuels

Cleaner Burning Gasoline, Oxygen Requirement for 

Wintertime In Lake Tahoe Area/Gas Pump Labeling for 

MTBE. T 13, CCR, 2262.5, and 2273

06/24/99 Fuels

Gasoline Vapor Recovery Systems. T 17, CCR, 94011, 

94153, 94155, and incorporated test procedures, CP-201, 

TP- 201.4, and TP-201.6

06/24/99 Vapor Recovery

Clean Fuels Regulation Requirements. T 13, CCR, 

sections 2300-2317, and 2303.5, 2311.5 07/22/99 On-road

Portable Container Spillage Control Measure. T 13, CCR, 

2470-2478 09/23/99 Off-road

Administrative Hearing Procedures. T 17, CCR, 60040 

and 60075.1-60075.45 10/22/99 Not applicable

California Consumer Products Regulation Mid-Term 

Measures II. T 17, CCR, 94508, 94509, and 94513 10/28/99 Consumer products

Area Designations for State Ambient Air Quality 

Standards. T 17, CCR, 60201 11/18/99 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

CaRFG Phase 3 Amendments (Phase out of MTBE, 

standards, predictive model). T 13, CCR, 2260, 2261, 

2262.1, 2262.5, 2263, 2264, 2264.2, 2265, 2266 etc...

12/09/99 Fuels

Off-Road Compression Ignition Engines. T 13, CCR, 

2111, 2112, 2137, 2139, 2140, 2141, 2144, 2400, 2401, 

2403, 2420, 2421, 2423-2427, & appendix A to article 

2.1.

01/27/00 Off-road

Transit Bus Standards. T 13, CCR, 1956.1, 1956.2, 

1956.3, 1956.4, 1956.8, 1965 02/24/00 On-road

Agricultural Burning Guidelines. T 17 Amendments 

80145, 80T 179, 80100-80102, 80110, 80120, 80130, 

80140, 80150, 80155, 80160, 80T 170, 80180, 80200, 

80210, 80230, 80240, 80250, 80260, 80270, 80280, 

80290, 80300, 80310, 80311, 80320, 80330

03/23/00 Not applicable

Enhanced Gasoline Vapor Recovery Systems (Emergency 

Filing CP-201, section 18). T 17, CCR, 94011 03/23/00 Vapor Recovery

Enhanced Gasoline Vapor Recovery Systems (In Station 

Diagnostics and Onboard Refueling Vapor Recovery). T 

17, CCR, 94011

03/23/00 Vapor Recovery

Air Toxic Control Measure for Chlorinated Toxic Air 

Contaminants from Automotive Maintenance and Repair 

Facilities. T 17, CCR, 93111

04/27/00 Other

Consumer Products Aerosol Adhesives Control Measure. 

T 17, CCR, 94508, 94509, 94512, 94513 05/25/00 Consumer products

Aerosol (Paint) Coatings Products. T 17, CCR, 94700, 

94701, 94521-94524, 94526 06/22/00 Consumer products

Air Toxic Control Measure for Asbestos Containing 

Serpentine. T 17, CCR, 93106 07/20/00 Not applicable

Conflict of Interest Code. T 17, CCR, 95001, 95002, 

95005, and subchapter 9 09/28/00 Not applicable

Rice Straw Conditional Burn Permit Program. T 17, CCR,

80101, 80156-80158 09/28/00 Not applicable

Air Toxics "Hot Spots" Fee Regulations. T 17, CCR,

90705 tables 1, 2, 3a, 3b, 3c, and 4 10/26/00 Not applicable

Antiperspirant and Deodorant Regulations. T 17, CCR, 

94502, 94504 10/26/00 Consumer products

Area Designations for the State Ambient Air Quality 

Standard for Ozone. T 17, CCR, 60201 11/16/00 Not applicable
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

CaRFG Phase 3 Follow-up Amendments. T 13, CCR, 

sections 2260, 2261, 2262.3, 2262.5, 2263, 2264, 2265, 

2266, 2266.5, 2270, 2272, 2273, 2282, 2296, 2297, 

2262.9 and incorporated test procedures

11/16/00 Fuels

CaRFG Phase 3 Test Methods. T 13, CCR, sections 

2263(b) 11/16/00 Fuels

Heavy Duty Diesel Engines "Not-to-Exceed (NTE)" Test 

Procedures. T 13 CCR, 1956.8, 2065 12/07/00 On-road

Light-and Medium Duty Low Emission Vehicle 

Alignment with Federal Standards. Exhaust Emission 

Standards for Heavy Duty Gas Engines. T 13, CCR, 

1956.8 &1961

12/07/00 On-road

Zero Emission Vehicle Regulation Update. T 13, CCR, 

1900, 1960.1(k), 1961, 1962 & incorporated Test 

Procedure

01/25/01 On-road

Ozone Transport Assessment. T 17, CCR, 70500 & 70600 04/26/01 Not applicable

Zero Emission Vehicle Infrastructure and Standardization 

of Electric Vehicle Charging Equipment. T 13, CCR, 

1900(b), 1962(b) 1962.1 

06/28/01 On-road

Airborne Toxic Control Measure for Asbestos from 

Construction, Grading, Quarrying, and Surface Mining. T 

17, CCR, 93105

07/26/01 Not applicable

Marine Inboard Engines. T 13, CCR, 2111, 2112, 2139, 

2140, 2147, 2440-2442, 2443.1-2443.3, 2444, 2445.1, 

2445.2, 2446, 2444.2 and incorporation of documents by 

reference

07/26/01 Off-road

Air Toxic Control Measures for Auto and Mobile Equip 

Refinishing Coatings containing Hexavalent Chromium 

and Cadmium Compounds. T 17, CCR, 93112

09/20/01 Not applicable

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90700-90705 10/25/01 Not applicable

Gasoline Vapor Recovery Systems Test Methods and 

Compliance Procedures. T 17, CCR, 94010, 94011, 

94153, 94155, 94163, 94164, 94165 & incorporated 

procedures

10/25/01 Vapor Recovery

Heavy Duty Diesel Engine Standards for 2007 and Later. 

T 13, CCR, 1956.8 and incorporated test procedures 10/25/01 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Distributed Generation Guidelines and Regulations. T 17, 

CCR, 94200-94214 11/15/01 Other

Gasoline Vapor Recovery Systems Defects. T 17, CCR, 

94006 and incorporated document. 11/15/01 Vapor Recovery

Low Emission Vehicle Regulations. T 13, CCR, 

1960.1,1960.5, 1961, 1962 and incorporate test 

procedures and guidelines

11/15/01 On-road

California Motor Vehicle Service Information Rule. T 

13&17, CCR, 1969 & 60060.1 - 60060.7 12/13/01 On-road

Airborne Toxic Control Measure for Outdoor Residential 

Waste Burning. T 17, CCR, 93113 02/21/02 Other

Voluntary Accelerated Light Duty Vehicle Retirement 

Regulations. T 13, CCR, 2601-2605, 2606 & appendices 

C & D, and 2607-2610

02/21/02 On-road

On-Board Diagnostic II Review Amendments. T 13, 

CCR, 1968.1, 1968.2, 1968.5 04/25/02 On-road

Diesel Retrofit Verification Procedure, Warranty and InUse Compliance Requirements. T 13, CCR, 2700-2710 05/16/02 On-road

Review of California Ambient Air Quality Standards for 

Particulate Matter and Sulfates. T 17, CCR, 70100,70200, 

and 70100.1

06/20/02 Not applicable

CaRFG Phase 3 Amendments. T 13, CCR, 2261, 2262, 

2262.4, 2262.5, 2262.6, 2262.9, 2266.5, 2269, 2271, 2272, 

2265, and 2296

07/25/02 Fuels

Revision to Transit Bus Regulations Amendments. T 13, 

CCR, 1956.1, 1956.2, 1956.4,1956.8, and 2112, & 

documents incorporated by reference

10/24/02 On-road

Administrative Civil Penalties Program. T 17, CCR,

60065.1 - 60065.45 and 60075.1 - 60075.45 12/12/02 Not applicable

Airborne Toxic Control Measure for Diesel Particulate 

from School Bus Idling. T13, CCR, 2480 12/12/02 On-road

CaRFG Phase 3 Amendments (specifications for De 

Minimis Levels of Oxygenates and MTBE Phase Out 

Issues). T 13, CCR, 2261, 2262.6, 2263, 2266.5, 2272, 

2273, 2260, 2273.5

12/12/02 Fuels
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Gasoline Vapor Recovery Systems Test Procedures. T 17, 

CCR, 94010, 94011, 94163, 94164, and 94165 and 

procedures incorporated by reference, and 94166, 94167, 

and incorporation by reference.

12/12/02 Vapor Recovery

Low Emission Vehicles II. Align Heavy Duty Gas Engine 

Standards with Federal Standards; minor administrative 

changes. T 13, CCR, 1961, 1965, 1956.8, 1956.1, 1978, 

2065 and documents incorporated by reference

12/12/02 On-road

Zero Emission Vehicle Amendments for 2003. T 13, 

CCR, 1960.1(k), 1961(a) and (d), 1900, 1962, and 

documents incorporated by reference

03/25/03 On-road

Ozone Transport Mitigation Regulations. T 17, CCR, 

70600 and 70601 05/22/03 Not applicable

Off-Highway Recreation Vehicles. T13, CCR, 2415 07/24/03 Off-road

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.75, 90800.9, 90804, 90800.8, 90801, 90802, 

and 90803

07/24/03 Not applicable

Specifications for Motor Vehicle Diesel Fuel. T 13 & T 

17, CCR, 1961, 2281, 2282, 2701, 2284, 2285, 93114, 

and incorporated test procedure

07/24/03 Fuels

Solid Waste Collection Vehicles. T 13, CCR, 2020, 2021, 

2021.1, 2021.2 09/24/03 On-road

Small Off-Road Engines (SORE). T 13, CCR, 2400-2409, 

2405.1, 2405.2, 2405.3, 2750-2754, 2754.1, 2754.2, 2755-

2767, 2767.1, 2768-2773 and the documents incorporated 

by reference

09/25/03 Off-road

Revised Tables of Maximum Incremental Reactivity 

Values. T 1, CCR, 94700. 12/03/03 Consumer products

Airborne Toxic Control Measure for Diesel Particulate for 

Transport Refrigeration Units. T 13, CCR, 2022 & 2477 12/11/03 On-road

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines. T 17, CCR 93115 & 

documents incorporate by reference

12/11/03 Other

Diesel Retrofit Verification Procedure, Warranty and InUse Compliance Requirements (Amendments). T 13, 

CCR, 2701-2707 & 2709 

12/11/03 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Area Designation Criteria and Area Designations for State 

PM2.5 and Ozone Ambient Air Quality Standards. T 17, 

CCR, 60201, 60202, 60205, 60210

01/22/04 Not applicable

CA Motor Vehicle Service Information Rule. T 13, CCR, 

1969 01/22/04 On-road

Airborne Toxic Control Measure for Diesel-Fueled 

Portable Engines. T 17, CCR,93116, 93116.1, 93116.2, 

93116.3, 93116.4, and 93116.5

02/26/04 Off-road

Modifications to the Statewide Portable Equipment 

Registration Program (PERP) Regulations . T 13, CCR 

Amendments to 2450-2465, and repeal of 2466

02/26/04 Off-road

Heavy Duty Diesel Engine-Chip Reflash. T 13, CCR, 

2011, 2180.1, 2181, 2184, 2185, 2186, 2192, and 2194 03/27/04 On-road

Engine Manufacturer Diagnostic System Requirements 

for 2007 and Subsequent Model Heavy Duty Engines. T 

13, CCR, 1971

05/20/04 On-road

Consumer Products & Methods 310/ATCM for ParaDicholorobenzene. T 17, CCR, 94501, 94506, 94507, 

94508, 94509, 94510, 94512, 94513, 94515, and 94526, 

and ARB Method 310, which is incorporated by reference 

06/24/04 Consumer products

Urban Bus Engines/Fleet Rule for Transit Agencies. T 13, 

CCR, 1956.1, 1956.2, 1956.3, and 1956.4, 06/24/04 On-road

Airborne Toxic Control Measure for Diesel Particulate 

from Diesel Fueled Commercial Vehicle Idling. T 13, 

CCR, 2485

07/22/04 On-road

Gasoline Vapor Recovery Systems at Dispensing 

Facilities. Emergency Filing. T 17, CCR, 94011 07/22/04 Vapor Recovery

Unihose Gasoline Vapor Recovery Systems. T17, CCR,

94011 07/22/04 Vapor Recovery

Gasoline Vapor Recovery System Equipment Defects 

List. T 17, CCR, 94006(b) & incorporated document 08/24/04 Vapor Recovery

Greenhouse Gas. T 13, CCR, 1961.1, 1900, 1961 and 

Incorporated Test Procedures 09/23/04 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

California Reformulated Gasoline, Phase 3. T 13, CCR, 

2260, 2262, 2262.4, 2262.5, 2262.6, 2262.9, 2263, 2265 

(and the incorporated ―California Procedures‖), and 

2266.5 

11/18/04 Fuels

Diesel Fuel Standards for Harbor Craft & Locomotives. T 

13, CCR, 2299, 2281, 2282, and 2284, and T 17, CCR, 

93117

11/18/04 Fuels

Enhanced Gasoline Vapor Recovery Systems Extension. 

T 17, CCR, 94011 and certification procedure 11/18/04 Vapor Recovery

Permit Fee Regulations for Non-vehicular Sources. T17, 

CCR 90805 and 90806; and 90800.8 and 90803 11/18/04 Not applicable

Emergency Regulation for Temporary Delay of Diesel 

Fuel Lubricity Standard. T 13, CCR, 2284 11/24/04 Fuels

Airborne Toxic Control Measure for Hexavalent 

Chromium and Nickel from Thermal Spraying. T 17, 

CCR, 93102.5

12/09/04 Not applicable

Off-Road Compression Ignition Engines. T 13, CCR, 

2420, 2421, 2423, 2424, 2425, 2427 12/09/04 Off-road

Area Designations. T 17, CCR, 60201, 60202, 60205, 

60210 01/20/05 Not applicable

Transit Fleet Rule. T 13, CCR, 2023, 2023.1, 2023.2, 

2023.3, 2023.4, 1956.1, 2020, 2021, repeal 1956.2, 

1956.3, 1956.4

02/24/05 On-road

State Ambient Air Quality Standard for Ozone. T 17, 

CCR, 70100, 70100.1, and 70200 04/28/05 Not applicable

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines (amendments). T 17, CCR,

93115

05/26/05 Other

Definition of Large Confined Animal Facility. T 17, CCR 

86500 and 86501 06/23/05 Not applicable

On-Board Diagnostic System Requirements for 2010 and 

Subsequent Model-Year Heavy-Duty Engines (HD OBD). 

T 13, CCR, 1971.1

07/21/05 On-road

Reid Vapor Pressure Limit. Emergency Rule. T 13, CCR, 

2262 and 2262.4 08/08/05 Fuels
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

2007-2009 Model-Year Heavy Duty Urban Bus Engines 

and the Fleet Rule for Transit Agencies. T 13, CCR, 

1956.1, 1956.2, and 1956.8

09/15/05 On-road

Portable Fuel Containers (PFC) [Part 2 of 2]. T 13, CCR 

2467.2, 2467.3, 2467.4, 2467.5, 2467.6, 2467.7; repeal of 

2467.8, and adoption of new 2467.8 and 2467.9. 

09/15/05 Off road

Portable Fuel Containers (PFC) [Part 1 of 2]. T 13, CCR, 

2467 and 2467.1 09/15/05 Off road

Requirements to Reduce Idling Emissions from New and 

In-Use Trucks, Beginning in 2008. T 13, CCR 

section1956.8 and the incorporated document

10/20/05 On-road

Airborne Toxic Control Measure for Cruise Ships 

Onboard Incineration. T 17, CCR, 93119 11/17/05 Off road

Marine Inboard Sterndrive Engines. T 13 CCR 2111, 

2112, 2441, 2442, 2444.2, 2445.1, 2446, 2447, and 

incorporated document

11/17/05 Off-road

Auxiliary Diesel Engines and Diesel-Electric Engines 

Operated on Ocean-Going Vessels within California 

Waters and 24 Nautical Miles of the California Baseline. 

T 13, CCR, 2299.1 and T 17, CCR, 93118

12/08/05 Off-road

Diesel Particulate Matter Control Measure for On-Road 

Heavy-Duty Diesel-Fueled Vehicles Owned or Operated 

by Public Agencies and Utilities. T 13, CCR, 2022 and 

2022.1

12/08/05 On-road

Mobile Cargo Handling Equipment at Ports and 

Intermodal Rail Yards. T 13, CCR, 2479 12/08/05 Off-road

AB1009 Heavy-Duty Vehicle Smoke Inspection Program. 

T 13, CCR, 2180, 2180.1, 2181, 2182, 2183, 2184, 2185, 

2186, 2187, and 2188, 2189

01/26/06 On-road

Identification of Tobacco Smoke as a Toxic Air 

Contaminant. T 17, CCR, 93000 01/26/06 Not applicable

Diesel Verification Procedure, Warranty & In-Use. T 13, 

CCR, 2702, 2703, 2704, 2706, 2707, and 2709. 03/23/06 On-road

Technical Amendments to Evaporative Exhaust and 

Evaporative Emissions Test Procedures. T 13, CCR, 

1961,1976 and 1978.

05/25/06 On-road
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Fork Lifts and Other Industrial Equipment. (Large OffRoad Spark Ignition Engines > 1 liter) T 13, CCR 2430, 

2433, 2434. Adopt 2775, 2775.1, 2775.2, 2780, 2781, 

2783, 2784, 2785, 2786, 2787, 2788, and 2789.

05/26/06 Off-road

California Motor Vehicle Service Information Rule. T 13, 

CCR, 1969 and incorporated documents 06/22/06 On-road

Gasoline Vapor Recovery Systems. T 17 CCR 94011 and 

incorporated certification 06/22/06 Vapor Recovery

Portable Equipment Registration Program. T 13, CCR, 

2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 

2459, 2460, 2461, 2462, 2463, 2464, and 2465

06/22/06 Off-road

Off-Highway Recreational Vehicles and Engines. T 13, 

CCR, 2411-2413, 2415 & documents incorporated by 

reference

07/20/06 Off-road

Heavy-Duty In-Use Compliance Regulation. T 13, CCR, 

1956.1, 1956.8, and documents incorporated by reference 09/28/06 On-road

On-Board Diagnostic II. T 13, CCR, 1968.2, 1968.5, 

2035, 2037 and 2038 09/28/06 On-road

Distributed Generation Guidelines and Regulations. T 17, 

CCR, 94201, 94201.1, 94203, 94204, & 94207-942142 10/19/06 Other

Zero Emission Bus Regulation. T13, CCR, 2023.1, 

2023.3, & 2023.4 10/19/06 On-road

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. T 17, CCR, 93300.5 and document 

incorporated by reference

11/16/06 Not applicable

Airborne Toxic Control Measure for Cruise Ships and 

Ocean-Going Ships Onboard Incineration (amendments). 

T 17, CCR, 93119

11/16/06 Off-road

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines (amendments, Agricultural 

Eng. Exemption removal). T 17, CCR, 93115.1-

93115.15.t.

11/16/06 Other

Area Designations for State Ambient Air Quality 

Standards. T 17, CCR, 60201, 60202, 60205, & 60210 11/16/06 Not applicable

Consumer Products. T 17, CCR, 94508, 94509, 94510, 

94513 & 94523 11/17/06 Consumer products
Appendix Table A-1

Measures Adopted by the California Air Resource Board

1990 to 2006

Measure Hearing 

Date Category

Emergency Regulation for Portable Equipment

Registration Program, Airborne Toxic Control Measures 

and Portable and Stationary diesel-Fueled Engines. T 13, 

CCR, 2452, 2455, 2456, 2461; T17 CCR 93115, 93116.2, 

93116.3

12/06/06 Off-road

Airborne Toxic Control Measure for Chrome Plating and 

Chromic Acid Anodizing Operations. T 17, CCR,

93102.1-93102.16

12/07/06 Not applicable

Voluntary Accelerated Retirement Regulation. T 13, 

CCR, 2601-2610 and appendices A-D

12/07/06 On-road
B. State Rules that Do Not Address Direct PM2.5 or PM2.5 Attainment Plan 

Precursors in the South Coast Nonattainment Area

A substantial number of the measures adopted by CARB since 1990 do not affect direct 

PM2.5 or a PM2.5 attainment plan precursor emissions in the South Coast nonattainment area. 

These types of measures include fee rules, identification of toxic air contaminants, area boundary 

designations, and controls for pollutants other than direct PM2.5 (or PM), NOx, VOC, or SO2. 

Appendix Table A-2 provides a list of these measures.

Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Transported Pollutants (Ozone). T 17, CCR, 70500 12/04/89 Not an emissions reduction 

measure

Non-vehicular Test Methods. T 17, CCR, 94002, 94003 

17, &26, 94146-94149, 94132, 94135, 94139, 94140 01/11/90 Not an emissions reduction measure

Test Method for Asbestos in Serpentine Aggregate. T 17, 

& 26, CCR, 94147, Method 435 04/12/90 Not an emissions reduction measure

Airborne Toxic Control Measure for Asbestos in 

Surfacing Applications. T 17, & 26, CCR, 93106 04/12/90 Not a PM emissions reduction measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.1, 90800, 90802-90803 05/10/90 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700-90704, 93300-93347 05/10/90 Not an emissions reduction measure

Dioxins Airborne Toxic Control Measure for Medical 

Waste Incinerators. T 17, CCR, 93104 07/12/90 Not a PM emissions reduction measure

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. T 17, & 26, CCR, 93300-93347 06/14/90 Not an emissions reduction measure

Criteria for Area Designations for the State Ambient Air 

Quality Standard. T 17, CCR, 70303 & 70304 06/14/90 Not an emissions reduction measure

Emissions Reduction Accounting Procedures for 

California Clean Air Act. T 17, CCR, 70700-70704 07/12/90 Not an emissions reduction measure

Identification of Inorganic Arsenic as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 07/12/90 Not an emissions reduction measure

Transport Mitigation Regulations. T 17, CCR, 70600-

70601 08/09/90 Not an emissions reduction measure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Air Toxic Fee Schedule & Emissions Inventory Criteria 

and Guidelines. T 17, & 26, CCR, 90700-90704, 93300-

93347

09/13/90 Not an emissions reduction 

measure

Identification of Trichloroethylene as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 10/11/90 Not an emissions reduction measure

Revision to Designation Criteria. T 17, CCR, 60200-

60204, 60208 11/08/90 Not an emissions reduction measure

Identification of Vinyl Chloride as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 11/13/90 Not an emissions reduction measure

Identification of Chloroform as a Toxic Air Contaminant. 

T 17, & 26, CCR, 93000 12/13/90 Not an emissions reduction measure

Conflict of Interest Code. T 17, CCR, 95001, et. seq. 12/13/90 Not an emissions reduction 

measure

Permit Fee Regulations for Non -Vehicular Sources. T 17, 

CCR, 90800.2, 90801, 90803 02/24/91 Not an emissions reduction measure

Non - Vehicular Test Methods. T 17, CCR, 94131, 94132, 

94142 04/11/91 Not an emissions reduction measure.

Acid Deposition Fee Regulations. T 17, CCR, 90621.2,

90620, 90622 04/11/91 Not an emissions reduction measure. Obsolete.

Administrative Hearing Procedures. T 17, CCR, 60075.1, 

60075.47 05/09/91 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700 - 90705 06/13/91 Not an emissions reduction measure

Agricultural Burning Guidelines. T 17, 80130, 80150, 

80250, 80260, 80290 07/11/91 Not an emissions reduction measure

Identification of Metallic & Inorganic Nickel Compounds 

as a Toxic Air Contaminant. T 17, & 26, 93000 08/08/91 Not an emissions reduction measure

State Ambient Air Quality Standard for SO2. T 17, CCR, 

70100, 70200, 70201 10/10/91 Not an emissions reduction measure

Identification of Perchloroethylene as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 10/10/91 Not an emissions reduction measure

Area Designations. T 17, CCR, 60200, 60209 11/14/91 Not an emissions reduction 

measure

Identification of Formaldehyde as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 03/12/92 Not an emissions reductionmeasure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Atmospheric Acidity Protection Fees. T 17, CCR, 

90621.3 04/09/92 Not an emissions reduction measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.3, 90803 04/09/92 Not an emissions reduction measure

Criteria for Area Designations. T 17, CCR, 70303, 70304 05/14/92 Not an emissions reduction 

measure

Transported Air Pollutants. T 17, CCR, 70500 05/28/92 Not an emissions reduction 

measure

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90701, 90704, 90705 07/09/92 Not an emissions reduction measure

Identification of 1.3 Butadiene as a Toxic Air 

Contaminant. T 17, & 26, CCR, 93000 07/09/92 Not an emissions reduction measure

CFC Refrigerants in Air Conditioning Systems. T 13, 

CCR, 2500 09/10/92

Not a PM or PM2.5 attainment plan 

precursors emissions reduction 

measure

Criteria for Area Designations. T 17, CCR, 70303.5, 

60200-60203, 60205, 70303 12/10/92 Not an emissions reduction measure

Transport Mitigation Regulations. T 17, CCR, 70600, 

70601 03/11/93 Not an emissions reduction measure

Identification of Federal Hazardous Air Pollutants as 

Toxic Air Contaminants. T 17, & 26, CCR, 93001, 39665, 

39666

04/08/93 Not an emissions reduction 

measure

Acid Deposition Fee Regulations. T 17, CCR, 90622, 

90621.4 04/08/93 Not an emissions reduction measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.4, 90803 04/08/93 Not an emissions reduction measure

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. T 17, & 26, CCR, 93300-93347 06/10/93 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700-90705 07/08/93 Not an emissions reduction measure

Mitigation Transport Pollutants. T 17, CCR, 70500, 

70600 08/12/93 Not an emissions reduction measure

Airborne Toxic Control Measure for Perchloroethylene 

Dry Cleaning. T 17, & 26, CCR, 93109, 93110 10/14/93

Not a PM or PM2.5 attainment plan 

precursors emissions reduction 

measure

Conflict of Interest. T 17, CCR, 90500 11/18/93 Not an emissions reduction 

measure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Criteria for Area Designations. T 17, CCR, 60200-60202, 

60204, 60206, 60208, 70300-70306 11/18/93 Not an emissions reduction measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.5, 90803 04/14/94 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, & 26, CCR, 

90700-90705 07/28/94 Not an emissions reduction measure

Area Designations. T 17, CCR, 60201, 60204 11/09/94 Not an emissions reduction 

measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.6, 90803 04/27/95 Not an emissions reduction measure

Employee-Based Trip Reductions Emission Formula. T 

13, CCR, 2330, 2331, 2332 06/29/95 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90700-90705 and Appendix A 01/25/96 Not an emissions reduction measure

Relaxation of Carbon Monoxide Emission Standards for 

Utility Engines. T 13, CCR, 2403 and incorporating test 

procedures

01/25/96 Carbon monoxide requirement

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90803, 90800.7 04/25/96 Not an emissions reduction measure

Basin Boundaries for Agricultural Burning (Mojave 

Desert, South Coast & Salton Sea). T 17, CCR, 60104, 

60109, 60114, 80280, 80311

05/30/96 Not an emissions reduction 

measure

Regulation Improvement and Repeal. T 17, CCR, 93301-

93355, Appendix A-E (emissions inventory) 05/30/96 Not an emissions reduction measure

Emissions Inventory Criteria & Guideline Report. T 17, 

CCR, 93300.5 07/25/96 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90701-90705 Appendix A to §§ 90700-90705 09/26/96 Not an emissions reduction measure

Stationary Source Test Methods. T 17, CCR, 94105, 

94107, 94114, 94135, 94141, 94143, 94161 09/26/96 Not an emissions reduction measure

Area Designations. T 17, CCR, 60201-60209 11/21/96 Not an emissions reduction 

measure

Transport Pollutants. T 17, CCR, 70500, 70600 11/21/96 Not an emissions reduction 

measure

Identification of Inorganic Lead as Toxic Air 

Contaminant (TAC). T 17, CCR, 93000 04/24/97 Not an emissions reduction measure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Interchangeable Emissions Reduction Credits. T 17, CCR, 

91500 05/22/97 Not an emissions reduction measure

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR 

90701-90705 and Appendix A §§ 90700-90705 11/13/97 Not an emissions reduction measure

Area Designations '97 . T 17, CCR, §§ 60201 & 60205 11/13/97 Not an emissions reduction 

measure

Permit Fee Regulations for Non-vehicular Sources. T 

17,CCR 90800.... 01/29/98 Not an emissions reduction measure

Classifying Minor Violations. T 17, CCR, 60090-60095 04/23/98 Not an emissions reduction 

measure

Airborne Toxic Control Measure for Chrome Plating. T

17, CCR, 93102 05/21/98 Not an emissions reduction measure

Identification of Diesel Exhaust as a Toxic Air 

Contaminant. T 17, CCR, 93000 08/27/98 Not an emissions reduction measure

Stationary Source Test Methods. T 17, CCR, 94101 -

94104, 94106, 94108 - 94113, 941T 17 - 94124, 94137 

and revision of Method 12.

10/22/98 Not an emissions reduction 

measure

Administrative Hearing Procedures. T 17, CCR, 60040 

and 60075.1-60075.45 10/22/99 Not an emissions reduction measure

Area Designations and Criteria for the National and State 

Ambient Air Quality Standards for Ozone. T 17, CCR,

60301, 60202, 60205, 60206, 70300-70306, 70303.1

10/22/98 Not an emissions reduction 

measure

Air Toxics ―Hot Spots‖ Fee Regulations. T 17, CCR, 

90701-90705 and Appendix A 10/22/98 Not an emissions reduction measure

Area Designations for State Ambient Air Quality 

Standards. T 17, CCR, 60201 11/18/99 Not an emissions reduction measure

Agricultural Burning Guidelines. T 17 Amendments 

80145, 80T 179, 80100-80102, 80110, 80120, 80130, 

80140, 80150, 80155, 80160, 80T 170, 80180, 80200, 

80210, 80230, 80240, 80250, 80260, 80270, 80280, 

80290, 80300, 80310, 80311, 80320, 80330

03/23/00 Not an emissions reduction 

measure

Air Toxic Control Measure for Asbestos Containing 

Serpentine. T 17, CCR, 93106 07/20/00

Not a PM or PM2.5 attainment plan 

precursors emissions reduction 

measure

Conflict of Interest Code. T 17, CCR, 95001, 95002, 

95005, and subchapter 9 09/28/00 Not an emissions reduction measure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Rice Straw Conditional Burn Permit Program. T 17, CCR,

80101, 80156-80158 09/28/00

Not a South Coast control measure

(Sacramento Valley air basin 

only)

Air Toxics "Hot Spots" Fee Regulations. T 17, CCR,

90705 tables 1, 2, 3a, 3b, 3c, and 4 10/26/00 Not an emissions reduction measure

Area Designations for the State Ambient Air Quality 

Standard for Ozone. T 17, CCR, 60201 11/16/00 Not an emissions reduction measure

Ozone Transport Assessment. T 17, CCR, 70500 & 70600 04/26/01 Not an emissions reduction 

measure

Air Toxics "Hot Spots" Fee Regulation. T 17, CCR, 

90700-90705 10/25/01 Not an emissions reduction measure

Review of California Ambient Air Quality Standards for 

Particulate Matter and Sulfates. T 17, CCR, 70100,70200, 

and 70100.1

06/20/02 Not an emissions reduction 

measure

Administrative Civil Penalties Program. T 17, CCR,

60065.1 - 60065.45 and 60075.1 - 60075.45 12/12/02 Not an emissions reduction measure

Ozone Transport Mitigation Regulations. T 17, CCR, 

70600 and 70601 05/22/03 Not an emissions reduction measure

Permit Fee Regulations for Non-vehicular Sources. T 17, 

CCR, 90800.75, 90800.9, 90804, 90800.8, 90801, 90802, 

and 90803

07/24/03 Not an emissions reduction 

measure

Area Designation Criteria and Area Designations for State 

PM2.5 and Ozone Ambient Air Quality Standards. T 17, 

CCR, 60201, 60202, 60205, 60210

01/22/04 Not an emissions reduction 

measure

Permit Fee Regulations for Non-vehicular Sources. T17, 

CCR 90805 and 90806; and 90800.8 and 90803 11/18/04 Not an emissions reduction measure

Area Designations. T 17, CCR, 60201, 60202, 60205, 

60210 01/20/05 Not an emissions reduction measure

State Ambient Air Quality Standard for Ozone. T 17, 

CCR, 70100, 70100.1, and 70200 04/28/05 Not an emissions reduction measure

Definition of Large Confined Animal Facility. T 17, CCR 

86500 and 86501 06/23/05 Not an emissions reduction measure

Identification of Tobacco Smoke as a Toxic Air 

Contaminant. T 17, CCR, 93000 01/26/06 Not an emissions reduction measure

Air Toxics "Hot Spots" Emissions Inventory Criteria and 

Guidelines. T 17, CCR, 93300.5 and document 

incorporated by reference

11/16/06 Not an emissions reduction 

measure
Appendix Table A-2

Measures Adopted by the California Air Resources Board

That Do Not Address PM2.5 in the South Coast Nonattainment Area

1990 to 2006

Measure Hearing 

Date Comments

Area Designations for State Ambient Air Quality 

Standards. T 17, CCR, 60201, 60202, 60205, & 60210 11/16/06 Not an emissions reduction measure
C. State Fuel Measures

CARB has adopted a number of revisions to its reformulated gasoline program and clean 

diesel program since 1990, as well as measures addressing other motor vehicle fuels and fuel 

standards for off-road sources. Appendix Table A-3 is a list of these revisions. 

Appendix Table A-3

Fuel Measures Adopted by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Wintertime Limits for Sulfur in Diesel Fuel. T 13, CCR, 

2255 06/21/90 Renumbered to section 2281. Approved 60 FR 43379 (8/21/95)

Limit on Aromatic Content of Diesel Fuel. T 13, CCR, 

2256 12/13/90

Renumbered to section 2282. 

Approved 60 FR 43379 (8/21/95) 

(listed as 4/15/01 adoption in FR)

Diesel Fuel Regulations - Emergency. T 13, CCR, 

2281(h), 2282(1) 10/15/93 Approved 60 FR 43379 (8/21/95) 

Small Refiner Diesel. T 13, CCR, 2282(e)(1) 07/24/94 Approved 60 FR 43379 (8/21/95) 

Diesel Fuel Test Methods. T 13, CCR, 1956.8(b), 

1960.1(k), 2281(c), 2282(b), (c) and (g) 10/24/96 Approved 75 FR 26653 (5/12/10)

Specifications for Motor Vehicle Diesel Fuel. T 13 & T 

17, CCR, 1961, 2281, 2282, 2701, 2284, 2285, 93114, 

and incorporated test procedure

07/24/03 Approved 75 FR 26653 (5/12/10)

Emergency Regulation for Temporary Delay of Diesel 

Fuel Lubricity Standard. T 13, CCR, 2284 11/24/04 Temporary delay of standard. Expired

Diesel Fuel Standards for Harbor Craft & Locomotives. T 

13, CCR, 2299, 2281, 2282, and 2284, and T 17, CCR, 

93117

11/18/04 See CARB 6/29/09 Letter

California Reformulated Gasoline (CaRFG), Phase I. T 

13, CCR, 2251.5 09/27/90 RVP standard for period between 1992 and 1996. Obsolete.

California Reformulated Gasoline, Phase II. T 13, CCR, 

2250, 2255.1, 2252, 2260 - 2272, 2295 11/21/91 Approved 60 FR 43379 (8/21/95)

Wintertime Gasoline Program. T 13, CCR, 2258, 2298, 

2251.5, 2296 11/21/91 Approved 60 FR 43379 (8/21/95)

Predictive Model for Phase II CaRFG. T 13, CCR, 2261, 

2262-2270 06/09/94 Superseded by 11/18/04 & 6/14/07 rules

Test Method for Oxygen in Gasoline. T 13, CCR, 

2251.5(c), 2258(c), 2263(b) 06/29/95

Section 2251.5 - obsolete; section 

2258 wintertime; section 2263, 

superseded
Appendix Table A-3

Fuel Measures Adopted by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Wintertime Oxygenate Program. T 13, CCR, 2258, 

2251.5, 2263(b), 2267, 2298, 2259, 2283, 2293.5 09/09/93 Carbon monoxide control measure

Test Methods for CaRFG 13, CCR, 2263(b) 10/26/95 Superseded by 11/18/04 & 

6/14/07 rules

Required Additives in Gasoline (Deposit Control 

Additives). T 13, CCR, 2257 and incorporates testing 

procedures.

11/16/95 Superseded by 11/18/04 & 

6/14/07 rules

CaRFG Housekeeping & CARBOB. T 13, CCR, 2263.7, 

2266.5, 2260, 2262.5, 2264, 2265, 2272 12/14/95 Superseded by 11/18/04 & 6/14/07 rules

CaRFG Variance Requirements. T 13, CCR, 2271 

(Emergency) 01/25/96 Superseded by 11/18/04 & 6/14/07 rules

Regulation Improvements and Repeals (fuel additives). T 

13, CCR, 2201, 2202 05/30/96 Repealed sections

Cleaner Burning Gasoline Model Flexibility. T 13, CCR, 

Sections 2260, 2262.1, 2262.3, 2262.4, 2262.5, 2262.6, 

2262.7 and 2265

08/27/98 Superseded by 11/18/04 & 

6/14/07 rules

Gasoline Deposit Control Additive Regulation. T 13, 

CCR, 2257, and incorporating test procedures 09/24/98 Superseded by 11/18/04 & 6/14/07 rules

Cleaner Burning Gasoline (Increasing the Oxygen 

Content). T 13, CCR, sections 2262.5(b) and 2265(a)(2) 12/11/98 Wintertime gasoline for South Coast and Imperial County. 

Cleaner Burning Gasoline, Oxygen Requirement for 

Wintertime In Lake Tahoe Area/Gas Pump Labeling for 

MTBE. T 13, CCR, 2262.5, and 2273

06/24/99 Not applicable to the SC

area/Obsolete

CaRFG Phase 3 Amendments (Phase out of MTBE, 

standards, predictive model). T 13, CCR, 2260, 2261, 

2262.1, 2262.5, 2263, 2264, 2264.2, 2265, 2266 etc...

12/09/99

2262.1 renumber to 2262.4; 2264 

(designation of alternative limits) 

not approved; otherwise 

superseded by 11/18/04 and 

6/14/07 rules

CaRFG Phase 3 Test Methods. T 13, CCR, sections 

2263(b) 11/16/00 Superseded by 11/18/04 & 6/14/07 rules

CaRFG Phase 3 Follow-up Amendments. T 13, CCR, 

sections 2260, 2261, 2262.3, 2262.5, 2263, 2264, 2265, 

2266, 2266.5, 2270, 2272, 2273, 2282, 2296, 2297, 

2262.9 and incorporated test procedures

11/16/00 Superseded by 11/18/04 & 

6/14/07 rules

CaRFG Phase 3 Amendments. T 13, CCR, 2261, 2262, 

2262.4, 2262.5, 2262.6, 2262.9, 2266.5, 2269, 2271, 2272, 

2265, and 2296

07/25/02 Superseded by 11/18/04 & 

6/14/07 rules
Appendix Table A-3

Fuel Measures Adopted by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

CaRFG Phase 3 Amendments (specifications for De 

Minimus Levels of Oxygenates and MTBE Phase Out 

Issues). T 13, CCR, 2261, 2262.6, 2263, 2266.5, 2272, 

2273, 2260, 2273.5

12/12/02

Superseded by 11/18/04 & 

6/14/07 rule. Approved 75 FR 

26653 (5/12/10) (except for 

section 2272 (CARFG3 standards 

for small refineries) and 2273.5 

(requirement to identify gasoline 

containing ethanol when delivered 

to retail station)) 

California Reformulated Gasoline, Phase 3. T 13, CCR, 

2260, 2262, 2262.4, 2262.5, 2262.6, 2262.9, 2263, 2265 

(and the incorporated ―California Procedures‖), and 

2266.5 

11/18/04 Approved 75 FR 26653 (5/12/10)

Reid Vapor Pressure Limit. Emergency Rule. T 13, CCR, 

2262 and 2262.4 08/08/05 Operative for September and October 2005 only. Obsolete.

Specifications for Liquid Petroleum Gas Used as a Motor 

Vehicle Fuel. T 13, CCR, 2292.6 12/11/98 No identifiable emissionsreductions

Liquefied Petroleum Gas Propane Limit Specification 

Delay. T 13, CCR, 2292.6 03/27/97 Expired
D. State On-Road Mobile Sources Measures

Appendix Tables A-4 and A-5 list measures adopted by CARB since 1990 for on-road 

and off-road sources.

Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Certification Procedure for Aftermarket Parts. VC 27156 & 

38391 02/08/90 Compliance provisions

Emission Standards for Medium Duty Vehicles. T 13, CCR, 

1900, 1956.8, 1960.1, 1968.1, 2061, 2112, 2139 06/14/90 Waiver granted September 16, 1994(59 FR 48625 (9/22/94))

Evaporative Emission Standards. T 13, CCR, 1976 08/09/90 Waiver granted August 25, 1994 (59 

FR 46979 (9/13/94))

Low Emission Vehicles and Clean Fuels. T 13, CCR, 1900, 

1904, 1956.8, 1960.1, 1960.1.5, 1960.5 and 2111, 2112, 

2125, and 2139, 2061.

09/28/90

Waivers granted January 7, 1993 & 

April 6, 1998 (58 FR 4166 (1/13/93) 

& 63 FR 18403 (4/15/98))

Heavy Duty Diesel Smoke Emission Testing. T 13, CCR, 

2180-2187 11/08/90 Inspection program

Onboard Diagnostics for Light-Duty Trucks and Light & 

Medium-Duty Motor Vehicles. T 13, CCR, 1977, 1968.1 09/12/91 Waiver granted October 2, 1996 (61 

FR 53371 (10/11/96))

Onboard Diagnostic, Phase II. T 13, CCR, 1968.1, 1977 11/12/91

Low Emission Vehicles amendments revising reactivity 

adjustment factor (RAF) provisions and adopting a RAF for 

M85 transitional low emission vehicles. T 13, CCR, 1960.1

11/14/91 Confirm within the scope finding 

requested February 18, 1993

Alternative Motor Vehicle Fuel Certification Fuel 

Specification. T 13 & 26, CCR, 2290-2292.7, 1960.1(k), 

1956.8(b), 1956.8(d)

3/12/92 Confirm within the scope finding 

requested February 17, 1994

Standards and Test Procedures for Alternative Fuel Retrofit 

Systems. T 13, CCR, 2030, 2031 05/14/92 Compliance provisions

Phase 2 RFG certification fuel specifications. T 13, CCR, 

1960.1, 1956.8(d) 08/13/92 Confirm within the scope finding requested February 17, 1994

Substitute Fuel or Clean Fuel Incorporated Test Procedures. 

T 13, CCR, 1960.1(k), 2317 11/12/92 Confirm within the scope finding requested February 17, 1994

Smoke Self Inspection Program for Heavy Duty Diesel & 

Gasoline Engines. T 13, CCR, 2190-2194, 2180-2187, 

1956.8(b)

12/10/92 Inspection program
Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Certification Requirements for Low Emission Passenger 

Cars, Light-Duty Trucks & Medium Duty Vehicles. T 13, 

CCR, 1960.1, 1976, 2061, 1900

01/14/93 Confirm within the scope finding 

requested February 21, 1994

Onboard Diagnostic, Phase II. T 13, CCR, 1968.1 07/09/93 Waiver granted October 2, 1996 (61 

FR 53371 (10/11/96))

Urban Transit Buses. T 13, CCR, 1956.8, 1965, 2112 06/10/93

Found within the scope September 

28, 2004 (69 FR 59920 (October 6, 

2004))

Evaporative Emission Standards and Test Procedures. T 13, 

CCR, 1976 02/10/94 Waiver granted July 28, 1999 (64 FR 42689 (8/5/99))

Diesel Fuel Certification. T 13, CCR, 1956.8(b)&(d), 

1960.1(k), 2292.6 09/22/94 Confirm within the scope finding requested September 14, 1995

Self Inspection Program for Heavy Duty Diesel Engines. T 

13, CCR, 2190-2194, 2180-2187, 1956.8(b) 11/09/94 Inspection program

Onboard Diagnostics, Phase II. T 13, CCR,1963.1, & 

Certification Procedures 12/08/94 Waiver granted October 2, 1996 (61 FR 53371 (10/11/96))

Periodic Smoke Inspection Program. T 13, CCR, 2190 12/08/94 Inspection program

Heavy Duty Vehicle Exhaust Emission Standards. T 13, 

CCR, 1956.8 and incorporate test procedures. 06/29/95 Found within the scope September 28, 2004 (69 FR 59920 (10/6/04))

Onboard Refueling Vapor Recovery Standards. T 13, CCR, 

1976, 1978 and incorporate test procedures 06/29/95 Waiver granted August 13, 2002 (67 FR 54180 (8/21/02))

Retrofit Emission Standards. T 13, CCR, 1956.9, 2030, 

2031, and incorporate test procedures 07/27/95 Compliance provision

Low Emission Vehicle Standards 3 (LEV 3). T 13, CCR, 

1956.8, 1960.1, 1965, 2101, 2061, 2062, and incorporate 

test procedures

09/28/95 Confirm within the scope finding 

requested October 8, 1996.

Postpone Zero Emission Vehicle Requirements. T 13, CCR, 

1900, 1960.1, 1976 03/28/96 Found within the scope January 18, 2001 (66 FR 7751 (1/25/01))

Diesel Fuel Certification Test Methods. T 13, CCR, 

1956.8(b), 1960.1(k), 2281(c), 2282(b), (c) and (g) 10/24/96 Confirm within the scope finding requested November 24, 1997

Onboard Diagnostics, Phase II, Technical Status. T 13, 

CCR, 1968.1, 2030, 2031 12/12/96 Initial notice 69 FR 5542 (February 5, 2004)

Postpone Enhanced Evaporative Emission Requirements for 

Ultra-Small Volume Vehicle Manufacturers. T 13, CCR, 

1976 and incorporate test procedures

05/22/97 Found within the scope July 28, 

1999 (64 FR 42689 (8/5/99))
Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Off-Cycle Emissions Supplemental Federal Test Procedures 

(SFTPs). T 13, CCR, 1960.1, 2101 and incorporate test 

procedures

07/24/97 Waiver granted September 30, 2004 

(69 FR 60996 (10/14/04))

Heavy Duty Vehicle Smoke Inspection Program/Periodic 

Smoke Inspection Program. T 13, CCR, 2180-2188 and 

2190-2194

12/11/97 Inspection program

Heavy Duty Vehicle Regulations: 2004 Standards. T 13, 

CCR, 1956.8, 1965, 2036, 2112 and test procedures 04/23/98 Confirm within the scope finding requested December 26, 2001

Low Emission Vehicles Standards (LEV 2) and Compliance 

Assurance Program (CAP 2000). T 13, CCR,1961 & 1962 

(both new); 1900, 1960.1, 1965, 1968.1, 1976, 1978, 2037, 

2038, 2062, 2101, 2106, 2107, 2110, 2112, 2114, 2119, 

2130, 2137-2140, 2143-2148

11/05/98

Waiver granted April 11, 2003 (68 

FR 19811 (4/22/03))/found within 

the scope (1999 ZEV amendments)

December 21, 2006 (71 FR 78190 

(12/28/06))

Exhaust Standards for (On-Road) Motorcycles. T 13, CCR, 

1958 12/10/98 Waiver granted July 27, 2006 (71 FR 44027 (8/3/06))

Voluntary Accelerated Light Duty Vehicle Retirement 

Regulations. T 13, CCR, 2600-2610 12/10/98

Establishes standards for a voluntary 

accelerated retirement program. 

Revised 2/21/06 and 12/7/06

Clean Fuels Regulation Requirements. T 13, CCR, sections 

2300-2317, and 2303.5, 2311.5 07/22/99

Removal of obsolete provisions, 

streamlining and other minor 

changes to 9/1990 rule.

Transit Bus Standards. T 13, CCR, 1956.1, 1956.2, 1956.3, 

1956.4, 1956.8, 1965 02/24/00

Combination of fleet requirements, 

emission standards, and zeroemission bus standards. Federal & 

state emission standards are the 

same for 2010 MY buses.

Light-and Medium Duty Low Emission Vehicle Alignment 

with Federal Standards. Exhaust Emission Standards for 

Heavy Duty Gas Engines. T 13, CCR, 1956.8 &1961

12/07/00

Waiver granted for LDV & HDV 

April 11, 2003 (68 FR 19811 

(4/22/03))

Initial notice on within-the-scope 

finding request for HDGE: 72 FR 

27114 (May 14, 2007).

Heavy Duty Diesel Engines "Not-to-Exceed (NTE)" Test 

Procedures. T 13 CCR, 1956.8, 2065 12/07/00 Confirm within the scope finding requested December 26, 2001.

Zero Emission Vehicle Regulation Update. T 13, CCR, 

1900, 1960.1(k), 1961, 1962 & incorporated Test Procedure 01/25/01 Found within the scope December 21, 2006 (71 FR 78190 (12/28/06))
Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Zero Emission Vehicle Infrastructure and Standardization of 

Electric Vehicle Charging Equipment. T 13, CCR, 1900(b), 

1962(b) 1962.1 

06/28/01 Found within the scope December 

21, 2006 (71 FR 78190 (12/28/06))

Heavy Duty Diesel Engine Standards for 2007 and Later. T 

13, CCR, 1956.8 and incorporate test procedures 10/25/01 Waiver granted August 19, 2005 (70 FR 50322 (8/26/05))

Low Emission Vehicle Regulations. T 13, CCR, 

1960.1,1960.5, 1961, 1962 and incorporate test procedures 

and guidelines

11/15/01 Found within the scope April 21, 

2005 (70 FR 22034 (4/28/05))

California Motor Vehicle Service Information Rule. T 

13&17, CCR, 1969 & 60060.1 - 60060.7 12/13/01

Compliance provision. Very similar 

to EPA regulations at 40 CFR 

86.1808.01

Voluntary Accelerated Light Duty Vehicle Retirement 

Regulations. T 13, CCR, 2601-2605, 2606 & appendices C 

& D, and 2607-2610

02/21/02

Establishes standards for a voluntary 

accelerated retirement program. 

Revised 12/7/06.

On-Board Diagnostic II Review Amendments. T 13, CCR, 

1968.1, 1968.2, 1968.5 04/25/02 Initial notice 69 FR 5542 (2/5/04)

Diesel Retrofit Verification Procedure, Warranty and In-Use 

Compliance Requirements. T 13, CCR, 2700-2710 05/16/02 Procedures to verify diesel retrofit technology. 

Revision to Transit Bus Regulations Amendments. T 13, 

CCR, 1956.1, 1956.2, 1956.4,1956.8, and 2112, & 

documents incorporated by reference

10/24/02 Slight relaxation in requirements 

over 2000 rule.

Low Emission Vehicles II. Align Heavy Duty Gas Engine 

Standards with Federal Standards; minor administrative 

changes. T 13, CCR, 1961, 1965, 1956.8, 1956.1, 1978, 

2065 and documents incorporated by reference

12/12/02

Waiver granted August 19, 2005 (70 

FR 50322 (8/26/05)) for all but 

HDGE. HDGE standards adopted to 

harmonize with EPA‘s. Initial notice 

on within-the-scope finding request 

for HDGE: 72 FR 27114 (5/14/07).

Airborne Toxic Control Measure for Diesel Particulate from 

School Bus Idling. T13, CCR, 2480 12/12/02 No emissions reductions claimed.

Zero Emission Vehicle Amendments for 2003. T 13, CCR, 

1960.1(k), 1961(a) and (d), 1900, 1962, and documents 

incorporated by reference

03/25/03 Found within the scope December 

21, 2005 (71 FR 78190 (12/28/06))
Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Solid Waste Collection Vehicles. T 13, CCR, 2020, 2021, 

2021.1, 2021.2 09/24/03

Diesel reduction program. Minimal 

reductions. See CARB, ―Staff 

Report: Initial Statement Of 

Reasons, Proposed Diesel Particulate 

Matter Control Measure for OnRoad Heavy-Duty Residential and 

Commercial Solid Waste Collection

Vehicles,‖ June 6, 2003, p. 53.

Airborne Toxic Control Measure for Diesel Particulate from 

Transport Refrigeration Units. T 13, CCR, 2022 and 2477 12/11/03 Waiver granted (non-road) January 9, 2009 (74 FR 3030 (1/16/2009))

Diesel Retrofit Verification Procedure, Warranty and In-Use 

Compliance Requirements (Amendments). T 13, CCR, 

2701-2707 & 2709 

12/11/03 Procedures to verify diesel retrofit 

technology. 

CA Motor Vehicle Service Information Rule. T 13, CCR, 

1969 01/22/04

Compliance provision. Very similar 

to EPA regulations at 40 CFR 

86.1808.01

Heavy Duty Diesel Engine-Chip Reflash. T 13, CCR, 2011, 

2180.1, 2181, 2184, 2185, 2186, 2192, and 2194 03/27/04 Compliance provision.

Engine Manufacturer Diagnostic System Requirements for 

2007 and Subsequent Model Heavy Duty Engines. T 13,

CCR, 1971

05/20/04 Waiver granted December 22, 2005

(71 FR 335 (1/4/06))

Urban Bus Engines/Fleet Rule for Transit Agencies. T 13, 

CCR, 1956.1, 1956.2, 1956.3, and 1956.4 06/24/04 Various modifications to urban/transit bus standards.

Airborne Toxic Control Measure for Diesel Particulate from 

Diesel Fueled Commercial Vehicle Idling. T 13, CCR, 2485 07/22/04 Diesel reduction program

Greenhouse Gas Standards. T 13, CCR, 1961.1, 1900, 1961 

and Incorporated Test Procedures 09/23/04 Waiver granted June 30, 2009 (74 FR 32744 (July 8, 2009)

Transit Fleet Rule. T 13, CCR, 2023, 2023.1, 2023.2, 

2023.3, 2023.4, 1956.1, 2020, 2021, repeal 1956.2, 1956.3, 

1956.4 

02/24/05 Diesel reduction program

On-Board Diagnostic System Requirements for 2010 and 

Subsequent Model-Year Heavy-Duty Engines (HD OBD). T 

13, CCR, 1971.1

07/21/05 Waiver granted August 13, 2008 (73 

FR 52042 (9/8/08))

2007-2009 Model-Year Heavy Duty Urban Bus Engines and 

the Fleet Rule for Transit Agencies. T 13, CCR, 1956.1, 

1956.2, and 1956.8

09/15/05 & 

10/20/05

Aligns State emission standards with 

federal emission standards.
Appendix Table A-4

On-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Requirements to Reduce Idling Emissions from New and InUse Trucks, Beginning in 2008. T 13, CCR section 1956.8 

and the incorporated document

10/20/05

Confirm not pre-empted or within 

the scope finding requested. Initial 

notice 75 FR 43975 (7/27/2010)

Diesel Particulate Matter Control Measure for On-Road 

Heavy-Duty Diesel-Fueled Vehicles Owned or Operated by 

Public Agencies and Utilities. T 13, CCR, 2022 and 2022.1

12/08/05

Diesel reduction program. Minimal 

reductions. See CARB, ―Staff 

Report: Initial Statement Of 

Reasons, Proposed Diesel Particulate 

Matter Control Measure for OnRoad Heavy-Duty Diesel-Fueled 

Vehicles Owned or Operated By 

Public Agencies And Utilities,‖ 

October 21, 2005, p. 55.

AB1009 Heavy-Duty Vehicle Smoke Inspection Program. T 

13, CCR, 2180, 2180.1, 2181, 2182, 2183, 2184, 2185, 

2186, 2187, and 2188, 2189

01/26/06 Requires trucks have emission 

control labels.

Diesel Verification Procedure, Warranty & In-Use. T 13, 

CCR, 2702, 2703, 2704, 2706, 2707, and 2709. 03/23/06

Procedures to verify diesel retrofit 

technology, supporting rule for inuse control measures.

Technical Amendments to Evaporative Exhaust and 

Evaporative Emissions Test Procedures. T 13, CCR, 

1961,1976 and 1978.

05/25/06 Within the scope finding July 22, 

2010 (75 FR 44948 (July 27, 2010)).

California Motor Vehicle Service Information Rule. T 13, 

CCR, 1969 and incorporated documents 06/22/06

Compliance provision. Very similar 

to EPA regulations at 40 CFR 

86.1808.01

On-Board Diagnostic II. T 13, CCR, 1968.2, 1968.5, 2035, 

2037 and 2038 09/28/06 Confirm within the scope finding requested.

Heavy-Duty In-Use Compliance Regulation. T 13, CCR, 

1956.1, 1956.8, and documents incorporated by reference 09/28/06

Compliance provision. Compliance 

program "essentially identical to 

EPA's." See Updated Information 

Digest for the Rule.

Zero Emission Bus Regulation. T13, CCR, 2023.1, 2023.3, 

& 2023.4 10/19/06

Delays ZEB requirements due to 

high bus costs and unproven 

durability, reliability and ability to 

produce the number of buses 

required by the regulation. See 

Updated Information Digest.

Voluntary Accelerated Retirement Regulation. T 13, CCR, 

2601-2610 and appendices A-D

12/07/06 Establishes standards for a voluntary 

accelerated retirement program.
Appendix Table A-5

Off-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Emission Standards for Utility and Lawn and Garden 

Engines. T 17, CCR, 2400 et. seq. 12/13/90

Waiver granted July 5, 1995 (60 

FR 37440 (7/20/95)) 1-year Implementation Delay in Emission Standards for 

Utility Engines. T 13, CCR, 2400, 2403-2407 04/08/93

Utility and Lawn and Garden Equipment Engines. T 13, 

CCR, 2403(c), 11(a)(1)(I)(ii), 4(a)(1)(I)(ii) 07/28/94

Within the scope finding 

November 9, 2000 (65 FR 69763 

(11/20/00))

Utility and Lawn and Garden Equipment Engines. CO 

Standards 1/25/96

Within the scope finding 

November 9, 2000 (65 FR 69763 

(11/20/00))

Small Off-Road Engines (SORE). T 13, CCR, 2400,

2410-2414 03/26/98

Within the scope finding

November 9, 2000 (65 FR 69767 

(11/20/00)), waiver granted 

(durability requirements), 

November 10, 2003 (65 FR 65702

(11/21/03)). 

Small Off-Road Engines (SORE). T 13, CCR, 2400-2409, 

2405.1, 2405.2, 2405.3, 2750-2754, 2754.1, 2754.2, 

2755-2767, 2767.1, 2768-2773 and the documents 

incorporated by reference

09/25/03 Waiver granted, December 11, 

2006 (71 FR 75536 (12/15/2006))

Off-Highway Recreational Vehicles. T 13, CCR, 2410-

2414, 2111-2140 01/03/94 Waiver granted December 23, 1996 (61 FR 69093 (12/31/1996))

Wintertime Requirements for Utility Engines & OffHighway Vehicles. T 13, CCR, 2403 09/26/96

Within the scope finding 

November 9, 2000 (65 FR 69763 

(11/20/00))

1997 & Later Model Off-Highway Recreational Vehicles 

and Engines. T 13, CCR, 2410-2414, 2415 12/10/98 Within the scope finding request March 4, 2000

Off-Highway Recreation Vehicles. T13, CCR, 2415 07/24/03

Addition to March 4, 2000 request 

November 19, 2004. Made 

changes to riding season 

restrictions.

Off-Highway Recreational Vehicles and Engines. T 13, 

CCR, 2411-2413, 2415 & documents incorporated by 

reference

07/20/06 Adopted evaporative emission 

standards identical to EPA's.
Appendix Table A-5

Off-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Heavy Duty Diesel Cycle Engines. T 13, CCR, 2420-

2427 01/09/92 Waiver granted May 15, 1995 (60 FR 48981 (9/21/1995))

Exemption of Military Tactical Vehicles. T 13, CCR, 

1905, 2400, 2420 12/14/95

Within the scope finding 

November 9, 2000 (65 FR 69763 

(11/20/00))

Off-Road Compression Ignition Engines. T 13, CCR, 

2111, 2112, 2137, 2139, 2140, 2141, 2144, 2400, 2401, 

2403, 2420, 2421, 2423-2427, & appendix A to article 

2.1.

01/27/00 Waiver granted, February 5, 2010 

(75 FR 8056 (2/23/2010)

Off-Road Compression Ignition Engines. T 13, CCR, 

2420, 2421, 2423, 2424, 2425, 2427 12/09/04 Waiver granted February 5, 2010 (75 FR 8056 (2/23/2010))

In-Use Off-Road Diesel Vehicles. T 13, CCR, 2449 07/26/07

Notice of opportunity for public 

hearing and comment (on waiver), 

75 FR 11880 (3/12/2010). 

Large Off-Road Spark-Ignition Engine Regulations. T 13, 

CCR, 2430 et seq., and 2411-2414 10/22/98 Waiver granted May 15, 2006 (71 FR 29623 (5/23/2006))

Fork Lifts and Other Industrial Equipment. (Large OffRoad Spark Ignition Engines > 1 liter) T 13, CCR 2430, 

2433, 2434. Adopt 2775, 2775.1, 2775.2, 2780, 2781, 

2783, 2784, 2785, 2786, 2787, 2788, and 2789.

05/26/06

Adopts EPA's Standards for 2007; 

adopts more stringent standards 

for 2010.

Emission Standards and Test Procedures for 2001 Marine 

Engines. T 13, CCR, 2440 et seq

12/10/98 Waiver granted March 22, 2007 

(59 FR 14546 (March 28, 2007))

Marine Inboard Engines. T 13, CCR, 2111, 2112, 2139, 

2140, 2147, 2440-2442, 2443.1-2443.3, 2444, 2445.1, 

2445.2, 2446, 2444.2 and incorporation of documents by 

reference

07/26/01

Waiver granted in part March 22, 

2007 (59 FR 14546 (March 28, 

2007)) 2007 standards waiver 

granted April 26, 2011 (76 FR 

24872 (5/3/11))

Marine Inboard Sterndrive Engines. T 13 CCR 2111, 

2112, 2441, 2442, 2444.2, 2445.1, 2446, 2447, and 

incorporated document

11/17/05

Revision to year 2007 standards in 

7/26/2001 marine inboard engine 

standards. Waiver requested 

February 7, 2008. 

Portable Equipment Registration Program. T 13, CCR, 

2450-2465 03/27/97

Revised by June 22, 2006 rule 

Waiver request 

withdrawn/replaced by favor of 

December 5, 2008 request

Revisions to Statewide Portable Equipment Registration 

Program. T 13, CCR, 2450-2463 12/10/98 Revised by June 22, 2006 rule
Appendix Table A-5

Off-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Modifications to the Statewide Portable Equipment 

Registration Program (PERP) Regulations . T 13, CCR 

Amendments to 2450-2465, and repeal of 2466

02/26/04 Revised by June 22, 2006 rule

Airborne Toxic Control Measure for Diesel-Fueled 

Portable Engines. T 17, CCR,93116, 93116.1, 93116.2, 

93116.3, 93116.4, and 93116.5

02/26/04

Notice of opportunity for public

hearing and comment published 

February 9, 2011 (76 FR 7196)

Within-the-scope finding/waiver 

requested March 28, 2005.

Portable Equipment Registration Program. T 13, CCR, 

2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 

2459, 2460, 2461, 2462, 2463, 2464, and 2465

06/22/06

Notice of opportunity for public

hearing and comment published 

February 9, 2011 (76 FR 7194)

Within-the-scope finding/waiver 

requested December 5, 2008.

Emergency Regulation for Portable Equipment 

Registration Program Airborne Toxic Control Measures 

and Portable and Stationary diesel-Fueled Engines. T 13, 

CCR, 2452, 2455, 2456, 2461; T17 CCR 93115, 93116.2, 

93116.3

12/06/06 Expired.

Portable Equipment Registration Program and Airborne 

Toxic Control Measure for Diesel-Fueled Portable 

Engines. T 13, CCR, 2451, 2452, 2456, 2458, 2459, 

2460, 2461, and 2462, T 17, CCR, 93116.1, 93116.2, 

93116.3 , 93116.3.1

03/22/07

Notice of opportunity for public

hearing and comment published 

February 9, 2011 (76 FR 7194)

Within-the-scope finding/waiver 

requested December 5, 2008.

Aftermarket Parts for Off-Road Engines. T 13, CCR, 

2470-2476 11/19/98 Compliance measure

Portable Container Spillage Control Measure. T 13, CCR, 

2470-2478 09/23/99 Similar federal regulation. 40 CFR part 59, subpart F.

Portable Fuel Containers (PFC) [Part 1 of 2]. T 13, CCR, 

2467 and 2467.1 09/15/05 Similar federal regulation. 40 CFR part 59, subpart F.

Portable Fuel Containers (PFC) [Part 2 of 2]. T 13, CCR 

2467.2, 2467.3, 2467.4, 2467.5, 2467.6, 2467.7; repeal of 

2467.8, and adoption of new 2467.8 and 2467.9. 

09/15/05 Similar federal regulation. 40 

CFR part 59, subpart F.

Airborne Toxic Control Measure for Diesel Particulate 

for Transport Refrigeration Units. T 13, CCR, 2022 & 

2477

12/11/03

Waiver granted (non-road) 

January 9, 2009 (74 FR 3030 

(1/16/2009))
Appendix Table A-5

Off-Road Mobile Source Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Mobile Cargo Handling Equipment at Ports and 

Intermodal Rail Yards. T 13, CCR, 2479 12/08/05

Notice of opportunity for public

hearing and comment published 

February 1, 2011 (76 FR 5586)

Within-the-scope finding and 

waiver request January 29, 2007

Airborne Toxic Control Measure for Cruise Ships 

Onboard Incineration. T 17, CCR, 93119 11/17/05 See Initial Statement of Reasons for Rule, p. II-1. 

Auxiliary Diesel Engines and Diesel-Electric Engines 

Operated on Ocean-Going Vessels within California 

Waters and 24 Nautical Miles of the California Baseline. 

T 13, CCR, 2299.1 and T 17, CCR, 93118

12/08/05

Airborne Toxic Control Measure for Cruise Ships and 

Ocean-Going Ships Onboard Incineration (amendments). 

T 17, CCR, 93119

11/16/06 Air toxics control measure

Ocean-Going Vessels At Berth (Shore Power). T 13, 

CCR, 2299.3 and T 17, CCR, 93118.3 and documents 

incorporated by reference

12/06/07 No emissions reductions claimed

Commercial Harbor Craft. T 13, CCR, 2222 and 

incorporated "California Evaluation Procedures for New 

Aftermarket Catalytic Converters"

11/15/07 No emissions reductions claimed

Cleaner Fuels in Ocean-Going Vessel Main Engines and 

Auxiliary Boiler. T 13, CCR, 2299.2 and T 17, CCR, 

section 93118.2

07/24/08 Proposed approval signed June 

29, 2011
E. State Consumer Product Measures

California has been regulating the VOC content of consumer products for 20 years and 

continues to tighten standards and regulate more products. Appendix Table A-6 is a list of 

CARB‘s rulemaking actions on consumer products since 1990.

Appendix Table A-6

Consumer Products Measures Adopted by the

California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Antiperspirant/Deodorants. T 17, CCR, 94500-94506 11/09/89 Approved 8/21/95 (60 FR 43379)

Consumer Products BAAQMD. T 17, CCR, 94520-94526 06/14/90 Not applicable to the South Coast

area

Phase I - Consumer Products. T 17, CCR, 94507-94517 10/11/90 Approved 8/21/95 (60 FR 43379)

Phase II - Consumer Products. T 17, CCR, 94501, 94502, 

94505, 94514, 94503.5, 94506, 94507 - 94513, 94515 01/09/92 Approved 8/21/95 (60 FR 43379)

Notice of General Public Interest for Consumer Products. 

T 17, CCR, 94507 - 94517 11/30/92 Not a control measure

Alternative Control Plan for Consumer Products. T 17, 

CCR, 94540-94555 09/22/94 Voluntary compliance option. No action.

Aerosol Coating Products and Alternative Control Plan. T 

17, CCR, 94520-94528, 94540-94543, 94547. 03/23/95 Superseded by 6/22/00 rule.

Antiperspirants and Deodorants, Consumer Products, and 

Aerosol Coating Products. T 17, CCR, 94500-94506, 

94508, 94521

09/28/95

Superseded by 6/24/04 rule for 

antiperspirants and deodorants;

superseded by 11/17/06 rule for 

consumer products; superseded 

by 11/17/06 rule for aerosol 

coating products.

Antiperspirants and Deodorants, Consumer Products, 

Aerosol Coating Products (ARB Test Method 310). T 17, 

CCR, 94506(a), 94515(a), 94526

11/21/96

Superseded by 6/24/04 rule for 

antiperspirants and deodorants;

superseded by 11/17/16 rule for 

consumer products; superseded 

by 11/17/06 rule for aerosol 

coating products.

Consumer Products and Aerosol Coating Products 

Amendments. T 17, CCR, 94508-94515, 99517, 94321 11/21/96 Superseded by 11/17/06 rule

Consumer Products (Hair Spray) Amendments. T 17, 

CCR, 94509, 94513, 94514 03/27/97 Voluntary compliance option. No action.
Appendix Table A-6

Consumer Products Measures Adopted by the

California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Consumer Products (Mid-Term Measures) Amendments. T 

17, CCR, 94508, 94509, 94513 07/24/97 Superseded by 11/17/06 rule

Consumer Products (Hairspray Credit Program). T 17, 

CCR, 94502, 94509, 94522, & 94548 11/13/97 Voluntary compliance option. No action.

Consumer Products, Aerosol Coatings & Antiperspirants 

and Deodorants. T 17, CCR, 94501, 94508, 94521, 94522, 

and 94524

11/19/98 Superseded by 11/17/06 rule

Consumer Products - LVP-VOC Definitions And Test 

Methods. T 17, CCR, 94506, 94506.5, 94508(a)(78), 

94515 and 94526, and the amendment of CARB Method 

310

11/19/98

Superseded by 6/24/04 rule for 

test method 310 and 11/17/06 

rule for rest.

California Consumer Products Regulation Mid-Term 

Measures II. T 17, CCR, 94508, 94509, and 94513 10/28/99 Superseded by 11/17/06 rule

Consumer Products Aerosol Adhesives Control Measure. 

T 17, CCR, 94508, 94509, 94512, 94513 05/25/00 Superseded by 11/17/06 rule

Aerosol (Paint) Coatings Products. T 17, CCR, 94700, 

94701, 94521-94524, 94526 06/22/00 Approved 9/13/05 70 FR 53920; superseded by 11/17/06 rule

Antiperspirant and Deodorant Regulations. T 17, CCR, 

94502, 94504 10/26/00 Superseded by 6/24/04 rule

Revised Tables of Maximum Incremental Reactivity 

Values. T 1, CCR, 94700. 12/03/03 Approved 9/13/05 70 FR 53920; superseded by 11/17/06 rule

Consumer Products & Methods 310/ATCM for ParaDicholorobenzene. T 17, CCR, 94501, 94506, 94507, 

94508, 94509, 94510, 94512, 94513, 94515, and 94526, 

and CARB Method 310, which is incorporated by 

reference 

06/24/04

Approved November 4, 2009 (74 

FR 57074) (EO order date of 

5/6/05)

Consumer Products. T 17, CCR, 94508, 94509, 94510, 

94513 & 94523 11/17/06

Approved November 4, 2009 (74 

FR 57074) (EO order date 

9/16/07)
F. State Vapor Recovery Measures

Under California State law (Health and Safety Code Sections 41954), CARB is required 

to adopt procedures and performance standards for controlling gasoline emissions from gasoline 

marketing operations, including transfer and storage operations. State law also authorizes CARB, 

in cooperation with the districts, to certify vapor recovery systems, identify defective equipment, 

and develop test methods. The installation and operation of CARB-certified vapor recovery 

equipment is required and enforced by District Rules 461 and 462. Appendix Table A-7 is a list 

of rulemaking actions taken by CARB since 1990 that address vapor recovery equipment 

certification, defects, and/or test methods.

Appendix Table A-7

Gasoline Vapor Recovery Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Gasoline Vapor Recovery Systems. T 17, CCR, 94010-

94015, 94150-94160, 94000-94004, 94007. 06/29/95

CARB sets requirements for and 

certifies vapor recovery 

equipment. District rules establish 

requirements for the installation of 

CARB-certified equipment. See 

SCAQMD Rules 461 & 462

Gasoline Vapor Recovery Systems. T 17, CCR, 94010-

94015 and 94150, 94156, 94157, 94158, 94159, 94160, 

94162

08/27/98

Gasoline Vapor Recovery Systems. T 17, CCR, 94011, 

94153, 94155, and incorporated test procedures, CP-201, 

TP- 201.4, and TP-201.6

06/24/99

Enhanced Gasoline Vapor Recovery Systems (In Station 

Diagnostics and Onboard Refueling Vapor Recovery). T 

17, CCR, 94011

03/23/00

Enhanced Gasoline Vapor Recovery Systems (Emergency 

Filing CP-201, section 18). T 17, CCR, 94011 03/23/00

Gasoline Vapor Recovery Systems Test Methods and 

Compliance Procedures. T 17, CCR, 94010, 94011, 

94153, 94155, 94163, 94164, 94165 & incorporated 

procedures

10/25/01

Gasoline Vapor Recovery Systems Defects. T 17, CCR, 

94006 and incorporated document. 11/15/01

Gasoline Vapor Recovery Systems Test Procedures. T 17, 

CCR, 94010, 94011, 94163, 94164, and 94165 and 

procedures incorporated by reference, and 94166, 94167, 

and incorporation by reference.

12/12/02

Unihose Gasoline Vapor Recovery Systems. T17, CCR,

94011 07/22/04
Appendix Table A-7

Gasoline Vapor Recovery Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Gasoline Vapor Recovery Systems at Dispensing 

Facilities. Emergency Filing. T 17, CCR, 94011 07/22/04

Gasoline Vapor Recovery System Equipment Defects 

List. T 17, CCR, 94006(b) & incorporated document 08/24/04

Enhanced Gasoline Vapor Recovery Systems Extension. 

T 17, CCR, 94011 and certification procedure 11/18/04

Gasoline Vapor Recovery Systems. T 17 CCR 94011 and 

incorporated certification 06/22/06

Vapor Recovery Aboveground Storage Tanks (AST). T 

17, CCR, 94010, 94011, 94016 and 94168 and 

incorporated documents

06/21/07

Gasoline Vapor Recovery System Equipment Defects 

List. T 17, CCR, 94006 N/A
G. Other State Measures

A number of CARB measures do not fall into one of the categories of measures listed in 

Appendix Tables A-2 through A-7. These measures are listed below in Appendix Table A-8.

Appendix Table A-8

Other Not Previously Listed Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Airborne Air Toxic Measure for Ethylene Oxide from 

Sterilizers & Aerators. T 17, CCR, 93108 05/10/90

Covered by District Rule 7021. 

Emissions in category are less 

than 0.01 tpd VOC

Controls for Abrasive Blasting. T 17, CCR, 92000, 

92200, 92400, 98500, 98510, 92520, 92530 11/08/90 Small source category in South Coast

Airborne Toxic Control Measure for Emission of Toxic 

Metals from Non-Ferrous Metal Melting. T 17 & 26, 

CCR, 93107

12/10/92 Adopted as District Rule 7060.

Air Toxic Control Measure for Chlorinated Toxic Air 

Contaminants from Automotive Maintenance and 

Repair Facilities. T 17, CCR, 93111

04/27/00 Mainly addresses non-VOC

Airborne Toxic Control Measure for Asbestos from 

Construction, Grading, Quarrying, and Surface Mining. 

T 17, CCR, 93105

07/26/01 Mainly addresses air toxics

Air Toxic Control Measures for Auto and Mobile 

Equipment Refinishing Coatings Containing 

Hexavalent Chromium and Cadmium Compounds. T 

17, CCR, 93112

09/20/01

Air toxic control measures 

prohibits additives with 

hexavalent chromium. Total 

emissions CA are less than 300 lb 

per year. ISOR, p. V-2.

Distributed Generation Guidelines and Regulations. T 

17, CCR, 94200-94214 11/15/01

Minimal impact, few units 

certified. See ISOR for 9/28/06 

rule amendment

Airborne Toxic Control Measure for Outdoor 

Residential Waste Burning. T 17, CCR, 93113 02/21/02

Regulated by Rules 4103 & 4106. 

Rule 4103 revised 5/17/07, 

approved 75 FR 74 FR 57907 

(11/10/09). Rule 4106 (revised 

6/21/01), approved 67 FR 8894 

(2/27/02); additional revision in 

2010.
Appendix Table A-8

Other Not Previously Listed Measures Adopted

by the California Air Resources Board

1990 to 2006

Measure Hearing 

Date Comments

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines. T 17, CCR 93115 & 

documents incorporate by reference

2/26/04

PM control measure. NOx

regulated by Rule 4702. (approved 

73 FR 1819 (1/10/08)). PM 

reductions are expected to be 

achieved primarily by replacement 

of existing engines as a result of 

District rule.

Airborne Toxic Control Measure for Hexavalent 

Chromium and Nickel from Thermal Spraying. T 17, 

CCR, 93102.5

12/09/04

Air toxic control measures. Total 

emissions (chromium & nickel in 

CA are less than 200 lb per year. 

ISOR, p. IV-6 to 8.

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines (amendments). T 17, 

CCR, 93115

05/26/053/17/05 Revisions to 2/26/04 rule. PM 

control measure. 

Airborne Toxic Control Measure for Stationary 

Compression Ignition Engines (amendments, In-Use 

Agricultural Eng. Exemption removal). T 17, CCR,

93115.1-93115.15.t.

11/16/06

PM control measure. NOx

regulated by Rule 4702. (approved 

73 FR 1819 (1/10/08)) PM 

reductions are expected to be 

achieved primarily by replacement 

of existing engines as a result of 

District rule.

Distributed Generation Guidelines and Regulations. T 

17, CCR, 94201, 94201.1, 94203, 94204, & 94207-

942142

10/19/06

Addition of 2013 standards NOx

and VOC standards for DG units 

which burn waste gas.

Airborne Toxic Control Measure for Chrome Plating 

and Chromic Acid Anodizing Operations. T 17, CCR,

93102.1-93102.16

12/07/06

Air toxic control measures. Total 

emissions in CA are 14.4 lb per 

year. ISOR, p. 49.
Appendix B – SCAQMD Rules
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

223 Large Confined Animal Feeding 

Operations 6/2/06 3/17/09 n/a n/a Baseline measure

401 Visible Emissions 11/09/01 7/10/84 1/29/85 50 FR 3907 Baseline measure

403 Fugitive Dust 6/3/05 10/20/05 03/10/08 73 FR 12639 Baseline measure

431.2. Sulfur Content Of Liquid Fuels 9/15/00 12/31/90 06/08/99 64 FR 30396 Baseline measure

442 Usage Of Solvents 12/15/00 05/08/01 05/23/02 67 FR 36105 Baseline measure

444 Open Burning 11/7/08 1/22/02 4/8/02 67 FR 16644 Baseline and control 

strategy measure

445 Wood Burning Devices 03/07/08 07/18/08 6/11/2009 74 FR 27716 Control Strategy 

measure

461 Gasoline Transfer and Dispensing 03/07/08 10/20/05 4/11/06 71 FR 18216 Baseline and control 

strategy measure

462 Organic Liquid Loading 05/14/99 06/03/99 07/21/99 64 FR 39037 Baseline measure

463 Organic Liquid Storage 05/6/05 10/20/05 01/04/07 72 FR 267 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1102 Petroleum Solvent Dry Cleaners 11/7/2000 5/08/01 7/17/02 67 FR 46876 Baseline measure

1103 Pharmaceuticals and Cosmetics 

Manufacturing 3/12/99 5/13/99 7/21/99 64 FR 39037 Baseline measure

1104 Wood Flat Stock Coating Operation 8/13/99 10/29/99 3/22/00 65 FR 15240 Baseline measure

1105 Fluid Catalytic Cracking Units - SOx 9/1/84 2/6/85 7/12/90 55 FR 28624 Baseline measure

1105.1 Reduction of PM and NH3 emissions 

from Fluid Catalytic Cracking Units 11/7/03 6/3/04 1/4/06 71 FR 241 Baseline measure

1106 Marine Coating Operations 1/13/95 2/24/95 7/14/95 60 FR 36225 Baseline measure

1106.1 Pleasure Craft Coating Operations 2/12/99 6/3/99 8/31/99 64 FR 47390 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1107 Coating of Metal Parts and Products 1/6/06 5/8/07 11/24/08 73 FR 70883 Baseline and control 

strategy measure

1108 Cutback Asphalt 2/1/85 4/12/85 7/12/90 55 FR 28624 Baseline measure

1108.1 Emulsified Asphalt 11/4/83 10/25/84 1/24/85 50 FR 3338 baseline measure

1109

NOx Emissions from Boilers and 

Process Heaters – Petroleum 

Refineries

8/5/88 3/26/90 1/13/00 65 FR 2052 Baseline measure

1110.2 Emissions from Gaseous and Liquid 

Fueled Engines 2/1/08 5/20/08 4/17/09 74 FR 18995 Control strategy measure

1111 NOx emissions from Natural-GasFired, Fan type Central Furnaces 11/6/09 5/17/10 8/4/10 75 FR 46845 Control strategy measure 

1112 NOx from Cement Kilns 6/6/86 10/10/86 6/25/90 55 FR 25832 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1112.1 PM from Cement Kilns 12/4/09 7/20/10 09/2/98 63 FR 46659 Baseline and control 

strategy measure

1113 Architectural coatings 7/13/07 3/07/08 8/17/11 76 FR 50891 Baseline and control 

strategy measure

1115 Motor Vehicle Assembly Line 

Coating Operations 5/12/95 6/16/95 7/14/95 60 FR 36225 Baseline measure

1117 NOx emissions from Glass Melting 

Furnaces 1/6/84 2/6/85 7/12/90 55 FR 28624 Baseline measure

1118 Refinery flares 11/4/05 10/5/06 8/28/07 72 FR 49196 Baseline measure

1121 Control of NOx from Residential type 

natural-gas-fired water heaters 9/3/04 7/18/08 5/6/09 74 FR 20880 Baseline and control strategy measure

1122 Solvent Degreasers 10/1/04 1/13/05 2/8/06 71 FR 6350 Baseline measure

1123 Refinery Process Turnarounds 12/7/90 5/13/91 8/11/92 57 FR 35758 Baseline measure

1124 Aerospace Assembly and Component 

Manufacturing Operations 9/21/01 1/22/02 8/13/02 67 FR 52611 Baseline measure 

1125 Metal Container, Closure, and Coil 

Coating Operations 03/7/08 4/6/09 12/21/09 74 FR 67844 Baseline and control strategy measure

1126 Magnet Wire Coating Operations 1/13/95 2/24/95 6/13/95 60 FR 31081 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1127 Emissions Reductions from Livestock 

Waste 8/6/04 10/5/06 n/a n/a Control strategy measures

1128 Paper, Fabric, and Film Coating 

Operations 3/8/96 7/23/96 5/4/99 64 FR 23774 Baseline measure

1130 Graphic Arts 10/8/99 1/21/00 9/13/00 65 FR 55201 Baseline measure

1130.1 Screen Printing Operations 12/13/96 3/3/97 8/21/98 63 FR 44792 Baseline measure

1131 Food Product Manufacturing and 

Processing Operations 6/6/03 8/11/03 1/22/04 69 FR 3018 Baseline measure

1132 Further Control of VOC from High 

Emitting Spray Booths 5/5/06 1/10/10 4/26/04 69 FR 22445 Baseline measure

1133, 1133.1, 

1133.2 Composting and Related Operations 1/10/03 6/5/03 7/21/04 69 FR 43518 Baseline measure

1134 NOx from Stationary Gas Turbines 8/8/97 3/10/98 8/1/00 65 FR 46873 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1135 NOx from Electric Power Generating 

Systems 7/9/91 1/28/92 8/11/98 63 FR 42721 Baseline measure

1136 Wood Products Coatings 6/14/96 8/28/96 8/18/98 63 FR 44132 Baseline measure

1137 PM10 Reduction from Woodworking 

Operations 2/1/02 11/9/02 1/22/04 69 FR 3018 Baseline measure

1138 Control of Emissions from Restaurant 

Operations 11/14/97 3/10/98 7/11/01 66 FR 36170 Baseline measure

1140 Abrasive Blasting 8/2/85 11/12/85 09/28/81 46 FR 47451 Baseline measure

1141 Control of VOC Emissions from 

Resin Manufacturing 11/17/00 3/14/01 8/13/02 67 FR 52611 Baseline measure

1141.1 Coatings and Ink Manufacturing 11/17/00 3/14/01 2/12/02 67 FR 6410 Baseline measure

1141.2 Surfactant Manufacturing 1/11/02 5/21/02 8/26/03 68 FR 51181 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1142 Marine Tank Vessel Operations 7/19/91 01/28/92 12/13/94 59 FR 64132 Baseline measure

1143 Consumer paint thinners and 

multipurpose solvents 12/3/10 4/5/11

proposed 

approval

7/15/11

76 FR 41744 Control strategy 

measure

1144 Metalworking fluids and direct 

contact lubricants 7/9/10 4/5/11

proposed 

approval 

7/15/11

76 FR 41744 Control strategy 

measure

1145 Plastic, Rubber, Leather and Glass 

Coatings 12/3/09 5/17/10 7/14/10 75 FR 40726 Control strategy measure

1146

NOx from Industrial, Institutional, and 

Commercial Boilers, Steam 

Generators, and Process Heaters

9/5/08 7/20/10

Proposed 

limited 

approval/limi

ted 

disapproval 

7/8/11

76 FR 40303 Control strategy 

measure

1146.1

NOx from Industrial, Institutional, and 

Commercial Boilers, Steam 

Generators, and Process Heaters

9/5/08 7/20/10

Proposed 

limited 

approval/limi

ted 

disapproval 

7/8/11

76 FR 40303 Control strategy 

measure

1146.2 NOx from Large Water Heaters and 

Small Boilers

5/5/06 3/7/08 12/5/08 73 FR 74027 Baseline measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1147 NOx Reductions from Miscellaneous 

Sources 12/5/08 5/17/10 8/4/10 75 FR 46845 Control strategy measure

1148 Thermally Enhanced Oil Recovery 

Wells 11/5/82 2/3/83 10/19/84 49 FR 41028 Baseline measure

1148.1 Oil and gas production wells 03/05/04 01/10/10 9/29/11 76 FR 60376

Baseline measure; first 

time this rule has been 

submitted to EPA

1149 Storage Tank Degassing 05/02/08 04/06/09 12/21/09 74 FR 67821 Control strategy measure

1150.1 Control of Gaseous Emissions from 

Active Landfills 03/17/00 07/26/00 07/01/02 67 FR 44062 Baseline measure

1151

Motor Vehicle and Mobile Equipment 

Non-Assembly Line Coating 

Operations

12/02/05 06/04/09 12/29/09 74 FR 68759 Baseline measure

1153 Commercial Bakery Ovens 01/13/95 02/24/95 08/08/95 60 FR 40285 Baseline measure

1156 PM10 Emissions Reductions from 

Cement Manufacturing 3/6/09 4/29/09 3/10/08 73 FR 12639 Control strategy measure

1157 PM10 Emissions Reductions from 

Aggregate and Related Operations 9/8/06 5/17/10 n/a n/a Baseline and control strategy measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1158 Storage, Handling and Transport of 

Petroleum Coke 7/11/08 12/23/08 11/10/09 74 FR 57907 Control strategy measure

1159 Nitric Acid Units - NOx- 12/6/85 2/10/86 7/12/90 55 FR 28622 Baseline measure

1162 Polyester Resin Operations 7/8/05 4/6/09 2/12/02 67 FR 6410 Baseline measure

1164 Semiconductor Manufacturing 1/13/95 2/24/95 2/1/96 61 FR 3579 Baseline measure

1166 VOC Emissions from Decontaminated 

Soil 7/14/95 10/13/95 8/17/98 63 FR 43884 Baseline measure

1168 Adhesive and Sealant Applications 1/7/05 4/29/09 12/12/03 68 FR 69320 Baseline measure

1171 Solvent Cleaning Operations 02/01/08 4/5/11 9/29/11 76 FR 60376 Baseline and control 

strategy measure
Table Appendix B -1

Status of South Coast Air Quality Management District Rules

for NOx, VOC, PM, and SOx

Rule No. Rule

Date of Most 

Recent Rule 

Adopted/ 

Revised

Date of Most 

Recent Rule 

Submitted

Date of Most 

Recent Rule 

Approved

Federal 

Register Cite Comments

1173 Fugitive VOC Emissions 2/6/09 1/10/10 5/5/10 75 FR 24406 Baseline and control 

strategy measure

1174 Control of VOC Emissions from the 

Ignition of Barbecue Charcoal 10/5/90 5/13/91 10/4/94 59 FR 50498 Baseline measure

1175

Control of Emissions from the 

Manufacture of Polymeric Cellular 

(Foam) Products

9/7/07 3/7/08 5/5/10 75 FR 24406 Baseline measure and 

control strategy measure

1176 Sumps and Wastewater Separators 9/3/96 11/26/96 10/7/02 67 FR 62376 Baseline measure

1178

Further Reductions of VOC Emissions 

From Storage Tanks at Petroleum 

Facilities

12/21/01 5/21/02 8/26/03 68 FR 51181 Baseline measure

1179 Publicly Owned Treatment Works 

Operations 3/6/92 9/14/92 10/4/94 58 FR 50498 Baseline measure

1186

PM10 Emissions from Paved and 

Unpaved Roads and Livestock 

Operations

7/11/08 12/23/08 11/14/05 70 FR 69081 Baseline and control 

strategy measure.

1189 Emission from Hydrogen Plant 

Process Vents 1/21/00 7/26/00 6/8/01 66 FR 30815 Baseline measure

2000-2015 RECLAIM 11/4/10 4/5/11 8/12/2011 76 FR 50128 Baseline and control 

strategy measure