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

Release Date: June 20, 2011

Hearing Date: July 21, 2011

Air Resources Board

California Environmental Protection Agency
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Introduction

On April 28, 2011, the Air Resources Board (ARB or Board) considered revisions to the South 

Coast and San Joaquin Valley State Implementation Plans (SIPs) for PM2.5 that accounted 

for reductions of emissions that contributes to PM2.5 levels. The revisions were formally 

adopted by the Board’s Executive Officer on May 18, 2011 when Executive Order S-11-010

was signed. The April 2011 PM2.5 SIP revisions accounted for recent regulatory actions and 

recessionary impacts on emissions that occurred after the South Coast and 

San Joaquin Valley PM2.5 SIPs were adopted in 2007 and 2008, respectively. Those 

revisions accounted for the impact the recession has had on emissions and the benefits of 

ARB’s in-use diesel truck and off-road equipment regulations. The revisions updated the

PM2.5 SIP’s reasonable further progress (RFP) calculations, transportation conformity 

budgets, and ARB’s rulemaking calendar. 

ARB staff is now proposing corresponding revisions to the 8-hour ozone SIPs adopted by the

South Coast and San Joaquin Valley Air Districts (Districts) in 2007. The same technical 

procedures used for the April 2011 PM2.5 SIP revisions were applied to estimate future 

emissions in 8-hour ozone SIP milestone years. Appendix A identifies the specific SIP 

revisions. Appendix B provides ARB staff's current estimate of remaining emissions after 

accounting for the impacts of the regulations and the recession and contains documentation 

for these estimates. Appendix C includes a description of the methodology used to calculate 

the proposed updated transportation conformity budgets for both the South Coast and San 

Joaquin Valley Air Basins. Appendix D provides the updated ARB rulemaking calendar, as 

adopted by ARB on May 18, 2011. Finally, Appendix E contains ARB staff’s analysis of 

environmental impacts of the proposed SIP revisions.

Description of Proposed Revisions to the 8-Hour Ozone SIPs

Appendix A contains the proposed SIP revisions and is intended for submittal to U.S. EPA. 

The proposed 8-hour ozone SIP revisions update the RFP calculations and the transportation 

conformity budgets. Staff is also proposing to update ARB’s rulemaking calendar for one 

measure, a revision to the calendar for cleaner in-use agricultural equipment. Appendix A 

also contains additional information on ARB actions to identify advanced emission control 

technologies in the South Coast and San Joaquin Valley.

Proposed Revisions to the 8-Hour Ozone SIP Reasonable Further Progress 

Calculations

ARB staff is proposing revisions to reflect the current estimate of remaining emissions 

in the RFP demonstrations for the South Coast and San Joaquin Valley. When ARB 

adopted the 2007 8-hour ozone SIPs for the South Coast and San Joaquin Valley, both 

regions demonstrated RFP in accordance with the Clean Air Act requirements. This 

continues to be true based on ARB staff’s current estimate of remaining emissions in 

both the South Coast and San Joaquin Valley. In order to make this demonstration 

available to U.S. EPA for inclusion in the 8-hour ozone SIPs, ARB staff has recalculated 

the RFP demonstrations and contingency measure accounting using the current 

estimate of remaining emissions. 
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Proposed Revisions to the 8-Hour Ozone SIP Transportation Conformity Budgets

ARB is proposing to update the transportation conformity budgets applicable to the 

federal 8-hour ozone standard for the South Coast and San Joaquin Valley Air Basins 

that will ensure that on-road emissions will be consistent with the attainment 

demonstration in future years. These updates account for the action taken by the 

Board in December 2010 to amend the truck and bus regulations, new data, and to

reflect the current rulemaking calendar. 

ARB staff is also proposing to make minor technical revisions to the South Coast and 

San Joaquin Valley PM2.5 SIP transportation conformity budgets adopted by the Board 

in April of 2011. 

Proposed Update to the 8-Hour Ozone SIP Rulemaking Calendar for Agricultural 

Equipment

When ARB adopted the recent revisions to the rulemaking calendar for California’s 

PM2.5 SIPs, ARB only adopted revisions as they related to the PM2.5 SIPs. The 

updated rulemaking calendar now needs to be adopted for inclusion in the South Coast 

and San Joaquin Valley 8-hour ozone SIPs, with the following addition: ARB staff is 

proposing to revise the rulemaking calendar for the cleaner in-use agricultural 

equipment measure consistent with the updated calendar for the other remaining 

ozone measures identified in the 2007 SIP. This measure is included in the 

San Joaquin Valley 8-hour ozone SIP but not the PM2.5 SIP. The ARB adopted

2011 PM2.5 rulemaking calendar submitted to U.S. EPA is included in Appendix D.

 

An incentive program is also being implemented to achieve early reductions in ozone 

precursors from agricultural equipment, primarily tractors. To date, about $70 million 

has been allocated by the San Joaquin Valley Air District and federal agencies to 

modernize off-road agricultural equipment. Benefits from this incentive program will be 

incorporated into the 8-hour ozone SIP for the San Joaquin Valley as emission 

reductions are achieved and accounting is completed.

ARB staff proposes to bring an agricultural equipment measure to the Board for 

consideration in 2013. The final implementation schedule would be determined in the 

rulemaking process as described in the 2007 SIP. The specific revision to the 

rulemaking calendar for agricultural equipment is included in Appendix A.

Actions to Identify and Implement Advanced Technologies to Reduce Ozone-forming 

Emissions 

While ozone air quality continues to improve in both the South Coast and 

San Joaquin Valley air basins, full attainment in these regions will require additional 

emission reductions. Advanced technologies are necessary in order to fully realize the 

emission reductions needed to attain the federal ozone standard by the attainment year 

of 2023. Appendix A summarizes ARB staff’s proposal to augment the discussion
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contained in the South Coast and San Joaquin Valley 8-hour ozone SIPs regarding

actions ARB will take to identify and implement the advanced technology provisions in 

accordance with the requirements of section 182(e)(5) of the federal Clean Air Act.

Complete List of Appendices

 Appendix A: Proposed State Implementation Plan Revision

o A-1: Proposed Revisions to the 8-hour Ozone SIP Reasonable Further Progress 

Calculations

o A-2: Proposed Revisions to the 8-hour Ozone and PM2.5 SIP Transportation 

Conformity Budgets

o A-3: Proposed Revisions to the 8-hour Ozone SIP Rulemaking Calendar for 

Agricultural Equipment

o A-4: Actions for Identifying and Implementing Advanced Technology Measures

 Appendix B: Current Estimates of Remaining Emissions, Documentation and 

Methodology

 Appendix C: Description of Technical Revisions to the 8-hour Ozone and PM2.5 SIP 

Transportation Conformity Budgets

 Appendix D: Adopted PM2.5 Rulemaking Calendar

 Appendix E: Analysis of Environmental Impacts
Appendix A

State Implementation Plan Revision

o A-1: Proposed Revisions to the 8-hour Ozone SIP Reasonable Further Progress 

Calculations

o A-2: Proposed Revisions to the 8-hour Ozone and PM2.5 SIP Transportation 

Conformity Budgets

o A-3: Proposed Revisions to the 8-hour Ozone SIP Rulemaking Calendar for 

Agricultural Equipment

o A-4: Actions for Identifying and Implementing Advanced Technology Measures
Appendix A - State Implementation Plan Revision

Appendix A-2 June 20, 2011

A-1

Revisions to the 8-hour Ozone SIP

Reasonable Further Progress Calculations

South Coast

(Summer Season, tons per day)

2002 2008 2011 2014 2017 2020 2023

Baseline ROG 880.5 632.0 579.9 535.2 519.8 513.9 513.4

CA MVCP/RVP Adjustment 0.0 56.1 73.0 86.6 93.7 98.3 101.6

RACT Corrections 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Adjusted 2002 Baseline ROG in milestone year 880.5 824.5 807.6 793.9 786.8 782.3 778.9

RFP commitment for ROG reductions from new 

measures

0.0 0.0 0.0 0.0 0.0 0.0 0.0

Future Year ROG with existing and proposed 

measures

632.0 579.9 535.2 519.8 513.9 513.4

Required % change since previous milestone 

year (ROG or NOx) compared to 2002 18% 9% 9% 9% 9% 9%

Required % change since 2002 (ROG or NOx) 18% 27% 36% 45% 54% 63%

Target ROG levels 676.1 599.8 533.4 479.0 431.7 389.8

Apparent shortfall in ROG -44.1 -19.9 1.7 40.8 82.2 123.6

Apparent shortfall in ROG, % -5.3% -2.5% 0.2% 5.2% 10.5% 15.9%

ROG shortfall previously provided by NOx 

substitution, % 0% 0.0% 0.0% 0.2% 5.2% 10.5%

Actual ROG shortfall, % -5.3% -2.5% 0.2% 5.0% 5.3% 5.4%

Baseline NOx 1024.1 728.3 591.2 532.1 478.8 428.2 378.4

CA MVCP Adjustment 0.0 64.7 80.6 93.0 98.3 102.4 105.9

Adjusted 2002 Baseline NOx in milestone year 1024.1 959.4 943.4 931.1 925.8 921.7 918.2

RFP commitment for NOx reductions from new 

measures

0.0 0.0 0.0 0.0 0.0 0.0 0.0

Change in NOx since 2002 231.1 352.3 398.9 447.0 493.5 539.7

Change in NOx since 2002, % 24.1% 37.3% 42.8% 48.3% 53.5% 58.8%

NOx reductions since 2002 already used for 

RFP substitution and contingency through last 

milestone year, %

0.0% 3.0% 3.0% 3.2% 8.2% 13.5%

NOx reductions since 2002 available for RFP 

substitution and contingency in this milestone 

year, %

24.1% 34.3% 39.8% 45.1% 45.4% 45.3%

Change in NOx since 2002 used for ROG 

substitution in this milestone year, % 0.0% 0.0% 0.2% 5.0% 5.3% 5.4%

Change in NOx since 2002 available for 

contingency in this milestone year, % 3.0% 3.0% 3.0% 3.0% 3.0% 3.0%

Change in NOx since 2002 surplus after 

meeting substitution and contingency needs in 

this milestone year, %

21.1% 34.3% 39.6% 40.1% 40.0% 39.9%

RFP Met? YES YES YES YES YES YES

Contingency Met? YES YES YES YES YES YES
Appendix A - State Implementation Plan Revision

Appendix A-3 June 20, 2011

A-1

Revisions to the 8-hour Ozone SIP 

Reasonable Further Progress Calculations

San Joaquin Valley

(Summer Season, tons per day)

2002 2008 2011 2014 2017 2020 2023

Baseline ROG 457.5 407.6 354.1 331.0 328.9 330.5 339.0

CA MVCP/RVP Adjustment 0.0 12.4 17.8 22.4 25.4 26.4 26.5

RACT Corrections 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Adjusted 2002 Baseline ROG in milestone year 457.5 445.1 439.7 435.0 432.0 431.0 431.0

RFP commitment for ROG reductions from new 

measures

0.0 0.0 0.0 0.0 0.0 0.0 0.0

Future Year ROG with existing and proposed 

measures

407.6 354.1 331.0 328.9 330.5 339.0

Required % change since previous milestone 

year (ROG or NOx) compared to 2002 18% 9% 9% 9% 9% 9%

Required % change since 2002 (ROG or NOx) 18% 27% 36% 45% 54% 63%

Target ROG levels 365.0 327.2 293.5 264.4 239.7 218.1

Apparent shortfall in ROG 42.6 26.9 37.5 64.5 90.9 121.0

Apparent shortfall in ROG, % 9.6% 6.1% 8.6% 14.9% 21.1% 28.1%

ROG shortfall previously provided by NOx 

substitution, % 0% 9.6% 9.6% 9.6% 14.9% 21.1%

Actual ROG shortfall, % 9.6% -3.4% -0.9% 5.4% 6.1% 7.0%

Baseline NOx 565.2 425.4 359.0 307.4 258.8 224.9 194.6

CA MVCP Adjustment 0.0 16.8 21.2 24.8 26.9 27.8 28.2

Adjusted 2002 Baseline NOx in milestone year 565.2 548.5 544.1 540.4 538.4 537.4 537.1

RFP commitment for NOx reductions from new 

measures

0.0 0.0 0.0 0.0 0.0 0.0 0.0

Change in NOx since 2002 123.1 185.1 233.0 279.5 312.5 342.5

Change in NOx since 2002, % 22.4% 34.0% 43.1% 51.9% 58.1% 63.8%

NOx reductions since 2002 already used for 

RFP substitution and contingency through last 

milestone year, %

0.0% 12.6% 12.6% 12.6% 17.9% 24.1%

NOx reductions since 2002 available for RFP 

substitution and contingency in this milestone 

year, %

22.4% 21.4% 30.6% 39.4% 40.2% 39.7%

Change in NOx since 2002 used for ROG 

substitution in this milestone year, % 9.6% 0.0% 0.0% 5.4% 6.1% 7.0%

Change in NOx since 2002 available for 

contingency in this milestone year, % 3.0% 3.0% 3.0% 3.0% 3.0% 3.0%

Change in NOx since 2002 surplus after 

meeting substitution and contingency needs in 

this milestone year, %

9.9% 21.4% 30.6% 34.0% 34.1% 32.7%

RFP Met? YES YES YES YES YES YES

Contingency Met? YES YES YES YES YES YES
Appendix A - State Implementation Plan Revision

Appendix A-4 June 20, 2011

A-2

Revisions to the 8-hour Ozone and PM2.5 SIP

Transportation Conformity Budgets

South Coast

8-hour Ozone SIP Transportation Conformity Budgets*

(Summer Season, tons per day)

2011 2014 2017 2020 2023

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

South Coast Air Basin 172 328 136 277 119 224 108 185 99 140

*Budgets are rounded up to the nearest ton.

In addition, at the time the 2007 SIP was adopted, a 2008 budget year was a necessary MPO analysis year for 

federal transportation conformity purposes. Since 2008 has passed, it is no longer applicable as a conformity 

analysis year, and was therefore not included in these budgets.

San Joaquin Valley

8-hour Ozone SIP Transportation Conformity Budgets**

(Summer Season, tons per day)

County 

Subarea

2011 2014 2017 2020 2023

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Fresno 14.3 36.2 10.7 30.0 9.3 22.6 8.3 17.7 8.0 13.5

Kern (SJV) 12.7 50.3 9.7 42.7 8.7 31.7 8.2 25.1 7.9 18.6

Kings 2.8 10.7 2.1 8.9 1.8 6.7 1.7 5.3 1.6 4.0

Madera 3.4 9.3 2.5 7.7 2.2 5.8 2.0 4.7 1.9 3.6

Merced 5.1 19.9 3.7 16.7 3.2 12.4 2.9 9.9 2.8 7.4

San Joaquin 11.1 24.6 8.4 20.5 7.2 15.6 6.4 12.4 6.3 10.0

Stanislaus 8.5 16.9 6.4 13.9 5.6 10.6 5.0 8.4 4.7 6.4

Tulare 8.8 16.0 6.7 13.2 5.8 10.1 5.3 8.1 4.9 6.2

** Budgets are rounded up to the nearest tenth ton (0.1).

In addition, at the time the 2007 SIP was adopted, a 2008 budget year was a necessary MPO analysis year for 

federal transportation conformity purposes. Since 2008 has passed, it is no longer applicable as a conformity 

analysis year, and was therefore not included in these budgets.
Appendix A - State Implementation Plan Revision

Appendix A-5 June 20, 2011

South Coast

PM2.5 SIP Transportation Conformity Budgets*

(Annual Average, tons per day)

2012 2014

ROG NOx PM2.5 ROG NOx PM2.5

South Coast Air 

Basin 154 326 37 132 290 35

*Budgets are rounded up to the nearest ton.

Per Section 93.124 of the conformity regulations, for transportation conformity analyses using 

these budgets in analysis years beyond 2014, a trading mechanism is established to 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. This trading mechanism will 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 emission reductions available to supplement the 

PM2.5 budget shall only be those remaining after the 2014 NOx budget has been met. Clear 

documentation of the calculations used in the trading should be included in the conformity 

analysis. 

In addition, at the time the 2007 SIP was adopted, a 2009 budget year was a necessary MPO 

analysis year for federal transportation conformity purposes. Since 2009 has passed, it is no 

longer applicable as a conformity analysis year, and was therefore not included in these budgets.
Appendix A - State Implementation Plan Revision

Appendix A-6 June 20, 2011

San Joaquin Valley

PM2.5 SIP Transportation Conformity Budgets**

(Annual Average, tons per day)

County 

Subarea

2012 2014

PM2.5 NOx PM2.5 NOx

Fresno 1.5 35.7 1.1 31.4

Kern (SJV) 1.9 48.9 1.2 43.8

Kings 0.4 10.5 0.3 9.3

Madera 0.4 9.2 0.3 8.1

Merced 0.8 19.7 0.6 17.4

San Joaquin 1.1 24.5 0.9 21.6

Stanislaus 0.7 16.7 0.6 14.6

Tulare 0.7 15.7 0.5 13.8

** Budgets are rounded up to the nearest tenth ton (0.1).

Per Section 93.124 of the conformity regulations, for transportation conformity analyses using 

these budgets in analysis years beyond 2014, a trading mechanism is established to 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 9:1. This trading mechanism will 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 emission reductions available to supplement the 

PM2.5 budget shall only be those remaining after the 2014 NOx budget has been met. Clear 

documentation of the calculations used in the trading should be included in the conformity 

analysis.

In addition, at the time the 2007 SIP was adopted, a 2009 budget year was a necessary MPO 

analysis year for federal transportation conformity purposes. Since 2009 has passed, it is no 

longer applicable as a conformity analysis year, and was therefore not included in these budgets.
Appendix A - State Implementation Plan Revision

Appendix A-7 June 20, 2011

A-3

Revisions to the 8-hour Ozone SIP 

Rulemaking Calendar for Agricultural Equipment

ARB adopted revisions to the rulemaking calendar for California’s PM2.5 SIPs on 

May 18, 2011. The updated rulemaking calendar is also intended for inclusion in the South 

Coast and San Joaquin Valley 8-hour ozone SIPs, with the following addition: the rulemaking 

calendar for the cleaner in-use agricultural equipment measure, has an action date of 2013 

consistent with the updated calendar for the remaining ozone measures identified in the 

2007 SIP. This measure is included in the San Joaquin Valley 8-hour ozone SIP but not the 

PM2.5 SIP. A copy of the PM2.5 SIP Rulemaking Calendar is included in Appendix D to this 

report for reference.

An incentive program is also being implemented to achieve early reductions in ozone 

precursors from agricultural equipment, primarily tractors. To date, about $70 million has 

been allocated by the San Joaquin Valley Air District and federal agencies to modernize offroad agricultural equipment. Benefits from this incentive program will be incorporated into the

8-hour ozone SIP for the San Joaquin Valley as emission reductions are achieved and 

accounting is completed.

Revisions to the 

8-hour Ozone SIP Rulemaking Calendar 

for Agricultural Tractors

Agency Actions Implementation

Off-Road Equipment

Cleaner In-use Agricultural Equipment1ARB 2013 See note

1

The final implementation schedule would be determined in the rulemaking process as described in the currently 

adopted ozone SIP. This measure is included in the San Joaquin Valley 8-hour ozone SIP and not the PM2.5

SIP.
Appendix A - State Implementation Plan Revision

Appendix A-8 June 20, 2011

A-4

Actions for Identifying and Implementing Advanced Technology Measures

Commitment to Reduce Emissions via Long-Term Strategy

Consistent with section 182(e)(5) of the federal Clean Air Act, this SIP includes long-term 

commitments to achieve the last increment of emission reductions necessary to fully meet 

attainment goals in the South Coast and San Joaquin Valley. As the State agency charged 

with ensuring California’s SIP compliance, the ARB is ultimately responsible for ensuring that

measures are identified no later than 2020 (three years prior to the attainment year) and the 

emission reductions achieved by 2023.

No later than 2020, ARB and the two air districts will prepare a revision to the 8-hour ozone 

SIP that: (1) reflects any modifications to the 2023 emission reduction target based on 

updated science, and (2) identifies any additional strategies, including the implementing 

agencies, needed to achieve the necessary emissions reductions by 2023. In accordance 

with section 182(e)(5)(B) of the Clean Air Act, ARB will submit enforceable commitments to 

develop and adopt contingency measures if the advanced technology measures do not 

achieve planned reductions. 

To implement the Long-term Strategy, ARB:

a) commits to share the results of its efforts to identify emerging emission reduction 

opportunities, promising technologies, and the progress made in developing long-term 

emission reduction measures with the public through periodic briefings to the Board,

workshops, conferences, symposia, website postings, and other means; 

b) commits to work to secure resources in the future for continuing research and 

development of new technologies; and

c) commits to develop schedules for moving from control technology research to 

implementation. 

While the Clean Air Act establishes timelines well into the future, ARB recognizes the 

challenges presented are near enough that action is needed in order to bridge the attainment 

gap in the South Coast and San Joaquin Valley. While not exhaustive, the following section 

describes on-going activities to identify and deploy the technologies needed to attain the 

ozone standard in the South Coast and San Joaquin Valley and to fulfill ARB’s commitment 

under section 182(e)(5) of the Clean Air Act. 

Clean Air Technology Initiative

U.S. EPA, along with ARB, the South Coast and San Joaquin Valley Air Districts and the 

California Environmental Protection Agency, signed a memorandum of agreement (MOA) to 

commit to developing and testing new technologies to accelerate progress in meeting current 

and future national air quality standards. The goal of the MOA is to improve air quality by 

aligning agency research resources, where possible and appropriate, to evaluate innovative 
Appendix A - State Implementation Plan Revision

Appendix A-9 June 20, 2011

technologies that have the potential to reduce emissions of pollutants and pollutant 

precursors, and to develop and assess new monitoring equipment that could improve the 

measurement of emissions from mobile and stationary sources of pollution. 

As part of this agreement, the agencies intend to coordinate research efforts with other public 

and private stakeholders, including other federal departments and agencies and other State 

and local entities, in order to utilize the resources and capacities of a wide sector of 

government and the business community in projects to develop, demonstrate, and assess 

new technologies that can help achieve clean air goals. 

A key element of the MOA was the creation of the Clean Air Technology Initiative, through 

which the partner agencies identify regionally important emission sources contributing to the 

region’s attainment challenges. Both the South Coast and San Joaquin Valley Air Districts

selected focus areas that are impacted by a mixture of mobile and stationary sources, 

especially sources representing major contributors to the SIP inventories and key air toxic

exposures in the community. The partner agencies then coordinate actions to align local, 

State, and federal resources to accelerate the identification and implementation of advanced 

clean technologies. The technologies demonstrated are intended to achieve significant 

reductions for SIP purposes as well as reduce local air toxics exposure. Below is a brief 

description of the focus areas for the two regions.

South Coast Air Basin Focus Area 

The City of San Bernardino has a large intermodal railyard with the highest health risk 

of all railyards in Southern California. This city is also impacted by goods movement 

activities that originate at the ports and move east via trucks and trains through 

San Bernardino and out of the State, as well as triggering new warehouse and 

distribution projects in inland areas. In addition, there are more than 1,000 stationary 

sources in the area holding South Coast Air District permits, such as autobody and 

automotive repair shops; transportation facilities; concrete and aggregate operations; 

military installations; printing and coating operations; and manufacturing facilities. 

San Joaquin Valley Air Basin Focus Area

The southern San Joaquin Valley focus area houses 1.2 million residents, and 

frequently exceeds health-based air standards when regional pollutants are trapped by 

surrounding mountains and atmospheric inversion layers. The focus area straddles 

Kern and Tulare counties, with mobile source emissions from the goods movement 

corridor of Highway 99 and Interstate 5, and stationary source emissions from a variety 

of energy production facilities, farms, and agricultural processing operations. The 

focus area includes the city of Bakersfield with the Valley’s highest wintertime 

particulate matter concentrations, and the city of Arvin, with some of the Valley’s 

highest 8-hour ozone concentrations in the summer.
Appendix A - State Implementation Plan Revision

Appendix A-10 June 20, 2011

Co-Benefits of Climate Change Programs

California is committed to reducing the State’s impacts on global climate change. California's 

major initiatives for reducing climate change or greenhouse gas (GHG) emissions are outlined 

in Assembly Bill 32 – the Global Warming Solutions Act of 2006 (AB 32). These efforts aim at 

reducing GHG emissions to 1990 levels by 2020 – a reduction of approximately 30 percent.

Reducing emissions from combustion sources is at the core of California’s program to meet 

the federal ozone standard and is also central to the AB 32 Scoping Plan for meeting the 

2020 greenhouse gas emissions target. California’s climate and criteria pollutant programs 

are complementary, and the AB 32 regulations ARB is adopting will provide emission 

reductions that will be incorporated into future air quality plans for ozone and fine particles.

Air Quality Improvement Program (AQIP)

The California Alternative and Renewable Fuel, Vehicle Technology, Clean Air, and Carbon 

Reduction Act of 2007 (Assembly Bill (AB) 118, Statutes of 2007, Chapter 750) creates the 

Air Quality Improvement Program (AQIP). This incentive program is administered by ARB to 

fund clean vehicle and equipment projects, research on biofuels production and the air quality 

impacts of alternative fuels, and workforce training. The AQIP expands California’s portfolio 

of air quality incentives, providing the opportunity to fund projects that do not fit within the 

statutory framework of existing incentive programs such as the Carl Moyer Air Quality 

Standards Attainment Program (Carl Moyer Program), Goods Movement Emission Reduction 

Program, and Lower-Emission School Bus Program.

AQIP is ARB’s only incentive program structured to allow for investments in technology 

advancing projects which also provide immediate emission reductions, and ARB is using 

AQIP funds for this purpose. AQIP investments support the deployment of hybrid-electric 

vehicles, zero-emission vehicles (ZEV), and other advanced technologies critical to meeting 

California’s post-2020 SIP and climate change emission reduction goals. California must start 

placing these zero- and near-zero emission vehicles on its roadways today to achieve largescale emission reductions in future decades because of the time it takes for significant fleet 

turnover. The cornerstone of the AQIP for FY 2009-10 is the $20.4 million Hybrid Truck and 

Bus Voucher Incentive Project (HVIP), aimed at accelerating California deployment of new 

hybrid medium- and heavy-duty vehicles. California’s large funding commitment for hybrid 

truck technology not only provides emission benefits today, but is likely to enable heavy-duty 

hybrids to become commonplace in the near future, much the way hybrid cars have become 

commonplace in the light-duty sector. Hybrid technology for trucks is near a tipping point, and 

the State’s investment over several years should help it become self-sustaining through 

production economies of scale.

AQIP is also funding vehicle purchaser incentives for other cleaner technologies – ZEV’s and 

plug-in hybrid cars, electric lawnmowers, and demonstration projects for cleaner marine and 

locomotive engines. These projects are on track as well. In nearly all cases, demand for 

funding is meeting or exceeding ARB’s expectations.
Appendix A - State Implementation Plan Revision

Appendix A-11 June 20, 2011

Annual Research Program

Annually, ARB adopts a research plan intended to provide timely scientific and technical 

information that will help the Board and local air pollution control districts to most effectively 

implement air pollution control programs in California. Specifically, this plan supports ARB’s 

mission to protect public health based on a strong scientific understanding of health effects 

and exposures; continue developing and implementing strategies to reduce GHG emissions 

and energy consumption; develop effective strategies to safeguard health and welfare against 

adverse impacts of ambient air pollution; and support development of technologies and nontechnological strategies that address multiple priorities related to air quality. The 2010/2011 

research program identified 25 projects to receive more than $6.5 million dollars in research 

funding. Cumulatively, California has granted nearly $24 million dollars in research funds 

since the 2007 8-hour ozone SIPs were adopted.

South Coast and San Joaquin Valley Air District Efforts

South Coast

The South Coast Air District has been a leader in identifying and implementing 

strategies to improve air quality through the use of innovative strategies and advanced 

technologies. In order to meet the region’s 2023 attainment goal, emissions of nitrogen 

oxides (NOx) will need to decline by an additional two-thirds by 2023. Achieving this 

goal will require a fundamental shift in business-as-usual to a clean-energy future. The 

South Coast Air District has identified a clean energy vision of the future that would 

guide the way as the region begins to recover from the economic recession that has 

affected the entire nation. 

This vision would have local, State and federal government and business leaders focus 

on utilizing the cleanest, greenest technologies in their planned growth. In order to fully 

realize the vision, the region would need to change how people and freight are moved 

– using electrification and hybridization technologies to convert existing infrastructure 

to near-zero emissions. Land-use decisions would put people closer to their 

destinations and would empower people to choose energy efficient mass transit. 

Energy generation and use would be cleaner. Solar and fuel cell distributed generation 

would play a significant role in meeting the region’s energy needs. Old inefficient 

power plants would be modernized with more efficient equipment. Building energy use 

would be improved and energy consumers would be given the tools needed to use 

energy more wisely.

San Joaquin Valley

The San Joaquin Valley Air District is also pursuing innovative strategies to reduce 

ozone-forming emissions, through the local “Fast Track” strategy. The Fast Track 

strategy focuses on using innovative strategies to reduce emissions from sources that 

cannot be regulated or have already been well controlled at the local level. Key long-
Appendix A - State Implementation Plan Revision

Appendix A-12 June 20, 2011

term elements of the Fast Track strategy include opportunities to reduce emissions 

from heavy-duty trucks by shifting goods movement to lower-emission alternatives. 

The San Joaquin Valley Air District has explored and advocated for the use of short 

sea shipping opportunities to shift goods movement from trucks to waterways. In 2010, 

the U.S. Department of Transportation awarded the Ports of Stockton, West 

Sacramento, and Oakland with a $30 million grant to move goods between Oakland 

and the two inland ports over the San Joaquin-Sacramento Delta.

The San Joaquin Valley Air District also recognizes the need for transformational 

changes in technology, and has adopted a Technology Advancement Program to 

support technological advancements through partnerships with universities, State 

agencies, and the federal government. The San Joaquin Valley Air District also 

established a Regional Energy Efficiency Strategy to support technology development 

and deployment in the Valley. The Regional Energy Efficiency Program lays out goals 

and measures that will guide the District’s actions to reduce emissions caused by 

electricity and natural gas consumption in residential, industrial, and institutional 

organizations in the Valley.

Conclusion

Achieving the emission reductions needed to fully attain the federal 8-hour ozone standard in 

the South Coast and the San Joaquin Valley will require significant penetration of the cleanest 

technologies. ARB, the South Coast Air District and the San Joaquin Valley Air District have a 

long history of pursuing innovative strategies to bring low and ultra-low emission technologies 

into use. ARB staff will periodically update the Board on these efforts and will revise the SIP 

as appropriate when advanced technologies become viable emission control strategies. 

Additionally, ARB will revise the SIP if needed, as California addresses future air quality 

standards. 
Appendix B

Current Estimates of Remaining Emissions, 

Documentation and Methodology
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-2 June 20, 2011

Appendix B includes additional documentation and data supporting this proposed SIP 

Revision. It includes additional detail regarding the emissions accounting methodology and 

information on how ARB staff accounted for the impacts of the recession. This methodology 

is consistent with the methodology described in Appendix A and Appendix E of the ARB staff 

report “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” which was 

released to the public on March 29, 2011. 

Current Estimates of Remaining Emissions

South Coast Air Basin

Remaining NOx Emissions

(Summer Season, tpd)

Category 2002 2008 2011 2014 2017 2020 2023

Stationary & Areawide 89 82 73 71 68 68 68

On-road Mobile 652 422 327 276 224 185 140

Off-road Mobile 283 225 191 185 187 176 170

Total Inventory 1024 728 591 532 479 428 378

South Coast Air Basin

Remaining ROG Emissions

(Summer Season, tpd)

Category 2002 2008 2011 2014 2017 2020 2023

Stationary & Areawide 318 247 252 254 260 267 273

On-road Mobile 361 211 171 135 119 107 98

Off-road Mobile 202 174 156 146 141 140 142

Total Inventory 881 632 580 535 520 514 513
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-3 June 20, 2011

Current Estimates of Remaining Emissions

San Joaquin Valley

Remaining NOx Emissions

(Summer Season, tpd)

Category 2002 2008 2011 2014 2017 2020 2023

Stationary & Areawide 101 76 68 57 55 53 53

On-road Mobile 312 229 183 153 115 91 69

Off-road Mobile 152 120 108 98 89 80 73

Total Inventory 565 425 359 307 259 225 195

San Joaquin Valley

Remaining ROG Emissions

(Summer Season, tpd)

Category 2002 2008 2011 2014 2017 2020 2023

Stationary & Areawide 276 263 226 223 229 235 244

On-road Mobile 110 78 66 50 43 39 37

Off-road Mobile 71 67 62 59 57 57 57

Total Inventory 457 408 354 331 329 331 339

SIP Accounting

The Clean Air Act requires the use of air quality modeling to determine the “carrying capacity” 

or “SIP emissions target”; that is, the maximum allowable emission levels that the 

nonattainment area can accommodate while attaining the standard.

While the adopted SIP contains a list of category-specific measures with regulatory timelines 

and expected reductions, ARB’s enforceable commitment is to meet the emission levels 

needed for attainment with sufficient aggregate emission reductions, including any from actual 

changes in emissions.

To track progress toward the emissions target, this report uses a simple emissions accounting 

approach that explicitly shows the impact of the recession and the benefit of the regulations 

ARB and the local air districts have approved since the ozone SIPs were adopted. The 

approach looks like:
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-4 June 20, 2011

(Emissions Inventory) – (Emission Reductions Achieved) = (Remaining Emissions)

Where: 

Emissions Inventory = Amount of ozone precursor emissions

in the SIP baseline

Emission Reductions 

Achieved

= Amount of emissions that have been

reduced either through adopted

regulations or actual emission

decreases due to the recession

Remaining Emissions = The ozone precursor emissions level

that is forecast to be

remaining in the attainment year with

the impacts of both regulations and the

recession.

This approach keeps the focus on meeting the ultimate goal of the emissions target derived 

from air quality modeling. This approach also has the advantage of explicitly showing the 

impacts of both the regulatory actions and the recession.

Assessing the Impacts of the Recession on Goods Movement Related Emissions

This section documents the methodologies used to account for the impacts of the economic 

recession on the emission inventories for trucks, in-use off-road equipment, ocean-going 

vessels, and cargo handling equipment. Links to more detailed information are provided.

General Methodology 

The economic recession officially started in December of 2007 and ended in June 2009. It 

was the most severe since the Great Depression and had a substantial impact on California 

industries. The emission inventories for trucks, in-use off-road equipment, ocean-going 

vessels, and cargo handling equipment have all been adjusted to reflect the recession’s 

impact.

To adequately understand the impact of reduced activity on future emissions, staff developed 

both fast and slow recovery scenarios. 

The fast recovery scenario assumes that total activity would return to projected historically 

average levels in 2017 and then grow at the historical average rate after that. This scenario is 

based on the Congressional Budget Office forecast which indicated that real gross domestic 

product at a nationwide level will converge with potential gross domestic product trends no 

later than 2015. Coupling this forecast with the assumption that California’s recovery will lag 

the nation’s by several years yielded the 2017 recovery date assumed for the fast recovery 

scenario. 
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-5 June 20, 2011

In the slow recovery scenario, staff assumed that activity would be permanently depressed 

relative to historical levels, but continue to grow at the average historical growth rate 

beginning in 2011.

While the fast and slow scenarios provide reasonable bounds of possible recoveries, for 

rulemaking purposes and for this SIP update, a single forecast is needed. For that forecast, 

staff assumed an average recovery midway between the fast and slow recoveries. The chart 

below illustrates the two bounding scenarios and the assumed average used in this report. 

This is the same approach developed to provide economic relief through last year’s regulatory 

amendments to the diesel trucks, buses, and off-road equipment rules.

2006 2008 2010 2012 2014 Growth Factor

Historical Forecast

Historical Average Growth

Recession

Fast

Slow

Average

Recovery

1.0

In-Use On-Road Trucks & Buses 

Staff updated the inventory for diesel trucks and buses to support ARB consideration of 

regulatory amendments to provide economic relief last December 2010. The update was 

comprehensive and included revised population estimates, new regional allocation factors, 

lifetime odometer assumptions, revised growth rates, forecasted vehicle age distributions to 

reflect the impact of the economic recession, and updated out-of-state vehicle activity. These 

changes are described in detail at: 

http://www.arb.ca.gov/regact/2010/truckbus10/truckbus10.htm 

This report required emission estimates for years and pollutants (ROG) that were not needed 
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-6 June 20, 2011

for the 2010 rulemaking staff report. Staff used the same methodologies and principles used 

for the December 2010 regulatory inventory to develop estimates for the other years and 

pollutants in this report.

In-Use Off-Road Equipment

Just as for trucks and buses, staff completed a comprehensive revision to the inventory for 

off-road equipment to support ARB consideration in December 2010 of regulatory 

amendments to provide economic relief. Updates were made to the population of equipment, 

annual activity, load, and future equipment sales. These changes are described in detail at:

http://www.arb.ca.gov/regact/2010/offroadlsi10/offroadlsi10.htm 

This report required emission estimates for years and pollutants (ROG) that were not needed

for the 2010 rulemaking staff report. Staff used the same methodologies and principles used 

for the December 2010 regulatory inventory to develop estimates for the other years and 

pollutants in this report.

Ocean-Going Vessels (OGV)

The OGV inventory in the ozone SIP included vessel-specific data, an improved vessel traffic 

network, vessel-specific hoteling and anchorage times, and improved vessel speeds. Staff 

has refined that inventory since then to support rulemaking in 2008 on the sulfur content in

fuel. Staff has further updated that 2008 inventory in anticipation of amendments to the same 

fuel rule later this year. That information is used in this report. In general, the updates 

include improved algorithms for vessel speed reduction (VSR), auxiliary engine power, and 

estimating low load adjustment factors. Recession impacts are based on container 

throughput statistics for the Ports of Los Angeles, Long Beach and Oakland. OGV activity 

was down about 25% for the combined Ports of Los Angeles and Long Beach and about 15% 

for the Port of Oakland between 2006 and 2009. More information is available at:

http://www.arb.ca.gov/ports/marinevess/ogv.htm

Cargo Handling Equipment (CHE)

An update to the cargo handling equipment (CHE) inventory is currently underway using new 

information about the population, equipment usage, impacts of the recession and fleet 

turnover. The new model is still under development and not available for use in this report; 

therefore, staff scaled the existing ozone SIP CHE emissions inventory to account for the new 

data.

The inventory used for the ozone SIP was based on population and activity values from a 

2001 to 2004 survey. As part of the adopted regulation, equipment owners were required to 

report the population of their equipment to ARB. Additionally, between 2005 and 2009 the 

ports and rail yards have conducted their own emission inventories. This new information 
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-7 June 20, 2011

indicates that the total State population is slightly higher than originally assumed. These 

same data sources include updates to activity and load factor. However, changes in activity 

and load factors offset these increases in the population.

To account for these changes, staff compared baseline 2006 emissions from the original 

inventory to the draft updated inventory baseline. As discussed in a recent February 2011 

workshop, emissions for NOx are approximately 27 percent lower. For this report, staff 

assumed 2006 emissions were 27 percent lower than in the SIP. To forecast emissions 

forward from 2006, staff compared the original growth assumptions for CHE to the growth in 

port truck activity in the 2010 Truck and Bus Rule inventory model. Assuming that the CHE 

activity relates chiefly to the movement of shipping containers, staff reduced growth by 

approximately 20 percent. More information is available at:

http://www.arb.ca.gov/ports/cargo/cargo.htm

Commercial Harbor Craft

In 2007, ARB adopted a commercial harbor craft regulation and adopted amendments to the 

original rule in 2010. Updates were made to the population of equipment, annual activity, and 

regional allocation. These changes are described in detail at:

http://www.arb.ca.gov/ports/marinevess/harborcraft/hcdocuments.htm#regulatory

Emission Inventory Improvements for the San Joaquin Valley

Nature of Emissions Update

The San Joaquin Valley Air Pollution Control District (Valley Air District) initially adopted the 

2007 8-hour ozone SIP in April 2007. At that time, the SIP reflected the best available 

emissions inventory estimates, technical calculations, and air quality modeling used to meet 

federal air quality planning requirements. 

Since the San Joaquin Valley 2007 8-hour ozone SIP was adopted, both ARB and the Valley 

Air District have continued to evaluate and update emission inventory categories under their 

respective authority. As described earlier in this Appendix, ARB has identified emissions 

inventory improvements through the recent rulemaking process for trucks, in-use off-road 

equipment, ocean-going vessels, and cargo handling equipment. These ARB emission

inventory improvements were submitted to U.S. EPA on May 18, 2011 as an update to the 

PM2.5 SIPs for the San Joaquin Valley and South Coast. The Valley Air District also identified 

emissions inventory and forecasting method improvements subsequent to the adoption of the 

2007 8-hour ozone SIP that were incorporated into the San Joaquin Valley 2008 PM2.5 SIP. 

ARB staff briefed the Board on the improvements in November 2007, when staff presented 

the Board with the report entitled “ARB Staff Report to the Air Resources Board: Accelerating 

San Joaquin Valley Air Quality Progress.” 
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-8 June 20, 2011

The San Joaquin Valley Air District improvements included using the most recent 

transportation activity data provided by Valley Metropolitan Planning Organizations and 

updates to several categories subject to recent District rulemaking (including agricultural 

burning and residential wood combustion). Revisions were also made to an emissions 

inventory methodology from the early 1990’s for a category identified as “unspecified” natural 

gas sources. This emissions inventory category labeled was “unspecified” because it was 

designed to estimate small emission sources potentially not identified in other emissions 

categories. A review of the methodology used to estimate and forecast this emission category 

showed that emissions were incorrectly calculated in the base year and a growth surrogate 

was applied which further increased the future year forecast. In the 2008 PM2.5 SIP, the San 

Joaquin Valley District revised this methodology to correct the inventory error. The 2008 

methodology is also being used in this ozone SIP update. 

In aggregate, the emission estimates based on ARB and San Joaquin Valley Air District 

improvements show a 12 percent reduction in baseline NOx emissions for 2002. The change 

in 2023 is relatively greater primarily because the “unspecified” natural gas emissions 

estimate was greater in 2023 than in 2002. The revised emission estimates are shown in 

Table B-1. 

Relationship to SIP Emissions Target

The SIP attainment demonstration shows how the 2023 emissions target will be met through 

a combination of adopted measures, new SIP measures, and 182(e)(5) emission reductions. 

The SIP emissions target represents the maximum allowable emissions level that the 

nonattainment area can accommodate while attaining the standard. The attainment 

demonstration in the San Joaquin Valley 8-hour ozone SIP was based on air quality modeling 

which used procedures set by U.S. EPA. To assess whether the emissions inventory 

improvements would affect the 2007 attainment demonstration, a qualitative review of the SIP 

modeling results was conducted. This review relied on the previous modeling results because 

in the near term it is not feasible to conduct new SIP modeling. Developing new SIP modeling 

and revisiting the adopted attainment demonstration would be a multi-year process. 

However, as part of the planning effort to address the expected revision to the federal 8-hour 

ozone standard, ARB will include 2023 attainment modeling for the current standard along 

with the attainment demonstration for the revised standard. If new modeling for 2023 shows 

that the emissions target has changed to require additional reductions, ARB will submit a 

revised commitment to provide the reductions needed to meet the emission target. 

Review of SIP Modeling Results

In accordance with U.S. EPA procedures, air quality models are used to predict the relative 

response to reductions in ozone-forming emissions for each site in the region. Two model 

runs are conducted. The first model run is for the reference year (in this case 2002) using a 

corresponding estimate of ozone-forming emissions in that year. The second model run is for 

a future year (in this case 2023) using forecasted emissions, including adopted controls, but 

no new SIP measures. This provides modeled ozone concentrations for 2002 and 2023. The 
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-9 June 20, 2011

ratio of these two concentrations is termed a relative reduction factor (RRF). The RRF 

reflects the modeled decrease in ozone levels between 2002 and 2023. The RRF is then

applied to an observed baseline ozone level calculated according to U.S. EPA guidance to 

project the expected ozone level in the attainment year. In the San Joaquin Valley this 

projected ozone level was above the federal 8-hour ozone standard, indicating additional 

emission reductions were needed.

To determine how many additional reductions were needed an ozone response diagram was 

developed. The modeling analyses showed that Arvin was the most restrictive site in the San 

Joaquin Valley for attainment of the federal 8-hour ozone standard. The ozone response 

diagram for Arvin is shown in Figure B-1. To develop this diagram, further modeling 

simulations were conducted, each using incremental reductions of 20, 40, and 60 percent

from the 2023 emissions forecast. From this information, the diagram provides the percent 

reduction needed to achieve an ozone concentration that meets the standard. This procedure 

established the SIP emissions target for the 2007 San Joaquin Valley ozone SIP. It is also 

apparent from Figure B-1 that the response to the NOx emission reductions is not linear. For 

example as you move down the diagram to greater NOx reductions, the rate of ozone

improvement gets larger. 

Determining an emission target based on revised emissions would require extensive new SIP 

modeling, following the process described above. However, to qualitatively assess the 

viability of the current attainment target, two pieces of information were key. First, as shown 

in Table B-1 the greater percent emission reductions resulting from the revised inventory 

would likely result in lower future ozone levels (a more responsive RRF). The diagram shows 

also that NOx reductions are the most effective precursor to control. Therefore, increasing 

amounts of NOx reductions result in a greater rate of air quality improvement. Taken together, 

these two pieces of information suggest that the existing emission targets are appropriate. 

The commitment to revisit the ozone modeling in the next San Joaquin Valley ozone SIP 

process will provide a timely review of the 2023 emissions target. 

Table B-1

Comparison of Original and Revised NOx Emission Estimates 

in the San Joaquin Valley

2007 SIP NOx

Emissions (tpd)

2011 NOx 

Emissions (tpd)

2002 Baseline 642 565

2023 Forecasted 

without SIP

295 225

Percent Change 

Between 2002 and 

2023

54% 60%
Appendix B - Current Estimates of Remaining Emissions, Documentation and Methodology

Appendix B-10 June 20, 2011

Figure B-1

Arvin 2023 Ozone Response Diagram
Appendix C

Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-1 June 20, 2011

8-hour Ozone SIP Transportation Conformity Budgets Methodology

ARB is proposing to update the transportation conformity budgets applicable to the federal 

8-hour ozone standard for the South Coast and San Joaquin Valley that will ensure that the 

impact of on-road emissions will be consistent with the attainment demonstration in future 

years. These updates account for the action taken by the Board in December 2010 to amend 

the truck and bus regulations to include better data and improvements to the emissions 

inventory, and reflect the current rulemaking calendar. Appendix A provides the SIP revision.

The federal Clean Air Act requires metropolitan planning organizations (MPOs) to 

demonstrate that their regional transportation plans (RTPs) and transportation improvement 

programs (TIP) are consistent with progress toward and attainment of federal air quality 

standards. MPOs use modeling to estimate regional emissions based on projected motor 

vehicle travel on the region’s road and transit facilities.

The level of emissions for on-road motor vehicles, such as cars, trucks, and buses, consistent 

with SIP progress and attainment, are called "Transportation Conformity Budgets.” For 

conformity, projected emissions from highway and transit use must be less than or equal to 

the budget. Budgets are developed during the air quality planning process in consultation 

with ARB, regional air districts, U.S. EPA, the U.S. Department of Transportation, and MPOs 

and provide for public review and comment.

The conformity budgets use the SIP on-road mobile source inventory which includes an 

updated heavy duty diesel truck and bus inventory that reflects the 2010 truck and bus 

regulatory amendments. This adjustment reflects the difference between the baseline SIP 

on-road motor vehicle emissions inventory from EMFAC2007 and the new truck and bus 

inventory that incorporates the impacts of both the recession and final regulations. The ton 

per day change in emissions is incorporated as a line item adjustment to the updated 

transportation conformity budgets (see “State Strategy Adjustments” line item in Tables C-1 

and C-2 below). 

Methodologically, the State Strategy Adjustments line item is then subtracted from the 

baseline SIP on-road motor vehicle emissions inventory from EMFAC2007. Importantly, the 

SIP baseline emissions inventory used to develop the transportation conformity budgets 

continues to be based on the activity data (e.g. vehicle miles travelled) provided by the MPOs 

included in the SIPs. 

This line item approach to account for State Strategy reductions is consistent with the 

approach used to develop the originally submitted budgets. The transportation conformity 

budget development worksheets are included in Tables C-1 and C-2 below, with the proposed 

SIP budgets found in Appendix A. 
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-2 June 20, 2011

Line-Item Adjustments in 8-hour Ozone Conformity Budgets for South Coast and 

San Joaquin Valley

The following section describes the line-item adjustments used in the existing transportation 

conformity budgets (as adopted in 2007) as well as those in the revised budgets ARB staff is 

proposing today. 

Line-Item Adjustments in the Existing 8-hour Ozone SIP Budgets

(Adopted 2007)

EMFAC2007 Baseline, covering 2008, 2011, 2014, 2017, 2020, and 2023 for South Coast 

and San Joaquin Valley

Line-Item Adjustments To Baseline For Measures 

Adopted Prior To December 2006

(Referred to as “Adjustments to Baseline” in Budgets, 

adjustments included in applicable years)

South Coast and San Joaquin Valley

 Heavy Duty Diesel Truck (HDDT) Chip Reflash

 HDDT Public Fleet and Solid Waste Rules

 HDDT Idling Rule

 AB 1493 GHG Standards

 On-Road Portion of Carl Moyer Program

San Joaquin Valley Only

 District Rule 9310 – School Buses
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-3 June 20, 2011

Line-Item Adjustments for Proposed SIP Measures

(Referred to as “State Strategy Reductions” in Budgets, 

adjustments included in applicable years)

South Coast and San Joaquin Valley

 All Smog Check Improvements (Low Pressure Evap, Cutpoints, 

Annual Insp. for Older, Annual Insp. for High Mileage, 

Motorcycles, Lt. Duty Diesels)

 HDDT In-Use Rule

 Reformulated Gasoline

 Expanded Vehicle Retirement

South Coast Only

 AB 923 High Emitter

San Joaquin Valley Only

 Indirect Source Rule

Line-Item Adjustments in the Proposed New Budgets

EMFAC2007 Baseline, covering 2011, 2014, 2017, 2020, and 2023 for South Coast and 

San Joaquin Valley

Line-Item Adjustments to Baseline for Measures

Adopted Prior to December 2006

(Referred to as “Adjustments to Baseline” in Budgets,

adjustments included in applicable years)

South Coast and San Joaquin Valley

 AB 1493 GHG Standards

 On-Road Portion of Carl Moyer Program

San Joaquin Valley Only

 District Rule 9310 – School Buses
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-4 June 20, 2011

Adjustments Now Included in New Heavy Duty Diesel Truck Model

(Included in “State Strategy Adjustments” in Budgets,

adjustments included in applicable years)

South Coast and San Joaquin Valley

 New HDDT Inventory

 HDDT Recession Impacts

 HDDT In-Use Rule

 HDDT Chip Re-flash

 HDDT Public Fleet and Solid Waste Rules

 HDDT Idling Rule

Line-Item Adjustments for Adopted SIP Measures

(Included in “State Strategy Adjustments” in Budgets, 

adjustments included in applicable years)

South Coast and San Joaquin Valley

 Smog Check Improvements (Low Pressure Evap, Cutpoints, 

Lt. Duty Diesels, Smoke Test)

 Reformulated Gasoline

San Joaquin Valley

 Employee Based Trip Reduction Rule
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-5 June 20, 2011

Table C-1

South Coast Air Basin

Ozone Transportation Conformity Emission Budget Worksheets*

(Summer Season – tpd)

South Coast Air Basin ROG NOx

2011 2014 2017 2020 2023 2011 2014 2017 2020 2023

Baseline Emissions (EMFAC 2007 Default) 176.0 150.1 131.1 117.0 106.1 367.7 299.9 243.5 200.2 171.8

Adjustments for Adopted State and Local On-road Measures -0.3 -0.6 -0.9 -1.1 -1.5 -1.4 -1.4 -1.0 -0.1 -0.1

State Strategy - On-road Reductions -4.5 -14.2 -11.5 -8.5 -6.2 -38.9 -22.3 -18.8 -15.6 -31.9

SUM 171.2 135.2 118.8 107.4 98.4 327.5 276.3 223.6 184.5 139.8

Proposed Budget 172 136 119 108 99 328 277 224 185 140

*Budgets are rounded up to the nearest ton. 
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-6 June 20, 2011

Table C-2

San Joaquin Valley Air Basin

Ozone Transportation Conformity Emission Budget Worksheets*

(Summer Season – tpd)

Proposed 2011 Transportation Conformity Budgets

County Subarea Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Baseline EMFAC2007 15.62 51.87 15.76 86.69 3.34 17.28 3.68 13.11 6.20 31.38 12.13 37.28 9.00 24.06 9.26 22.41

Existing Measures: 

Local Reductions 0.00 0.03 0.00 0.02 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.03 0.00 0.02 0.00 0.02

State Reductions 0.01 0.10 0.01 0.12 0.00 0.03 0.00 0.02 0.01 0.05 0.01 0.08 0.01 0.05 0.01 0.04

New/Proposed Measures:

Local Reductions 0.15 0.05 0.10 0.04 0.02 0.01 0.02 0.01 0.04 0.02 0.12 0.04 0.09 0.03 0.07 0.03

State Reductions 1.20 15.51 3.01 36.29 0.57 6.62 0.36 3.85 1.14 11.45 0.95 12.57 0.46 7.15 0.41 6.42

Total 14.27 36.17 12.63 50.22 2.74 10.62 3.30 9.23 5.01 19.85 11.06 24.56 8.45 16.81 8.77 15.90

Budget* 14.3 36.2 12.7 50.3 2.8 10.7 3.4 9.3 5.1 19.9 11.1 24.6 8.5 16.9 8.8 16.0

*Budgets are rounded up to the nearest tenth ton (0.1). 
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-7 June 20, 2011

Proposed 2014 Transportation Conformity Budgets

County Subarea Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Baseline EMFAC2007 13.04 40.67 13.56 70.77 2.75 13.53 3.04 10.53 5.07 24.61 10.19 30.08 7.54 18.71 7.76 17.84

Existing Measures: 

Local Reductions 0.00 0.05 0.00 0.04 0.00 0.01 0.00 0.01 0.00 0.02 0.00 0.05 0.00 0.03 0.00 0.03

State Reductions 0.01 0.10 0.01 0.12 0.00 0.03 0.00 0.02 0.01 0.05 0.01 0.08 0.01 0.05 0.01 0.04

New/Proposed Measures:

Local Reductions 0.29 0.27 0.21 0.19 0.05 0.04 0.05 0.04 0.09 0.08 0.24 0.23 0.17 0.16 0.14 0.13

State Reductions 2.10 10.30 3.68 27.76 0.69 4.56 0.56 2.80 1.33 7.84 1.63 9.31 1.02 4.60 0.99 4.48

Total 10.64 29.95 9.66 42.65 2.00 8.89 2.43 7.66 3.64 16.62 8.31 20.42 6.34 13.86 6.62 13.16

Budget* 10.7 30.0 9.7 42.7 2.1 8.9 2.5 7.7 3.7 16.7 8.4 20.5 6.4 13.9 6.7 13.2

*Budgets are rounded up to the nearest tenth ton (0.1).

Proposed 2017 Transportation Conformity Budgets

County Subarea Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Baseline EMFAC2007 11.18 32.41 11.67 55.71 2.31 10.52 2.59 8.54 4.21 19.24 8.64 23.57 6.50 14.76 6.70 14.35

Existing Measures: 

Local Reductions 0.00 0.13 0.00 0.09 0.00 0.02 0.00 0.02 0.00 0.04 0.00 0.11 0.00 0.08 0.00 0.06

State Reductions 0.01 0.07 0.01 0.09 0.00 0.02 0.00 0.02 0.00 0.03 0.01 0.06 0.01 0.03 0.01 0.03

New/Proposed Measures:

Local Reductions 0.20 0.22 0.14 0.16 0.03 0.04 0.03 0.04 0.06 0.07 0.18 0.19 0.12 0.13 0.10 0.11

State Reductions 1.68 9.42 2.85 23.78 0.51 3.83 0.45 2.68 1.01 6.72 1.27 7.70 0.81 4.01 0.81 4.09

Total 9.29 22.57 8.66 31.60 1.76 6.62 2.10 5.79 3.13 12.38 7.18 15.51 5.56 10.51 5.79 10.06

Budget* 9.3 22.6 8.7 31.7 1.8 6.7 2.2 5.8 3.2 12.4 7.2 15.6 5.6 10.6 5.8 10.1

*Budgets are rounded up to the nearest tenth ton (0.1).
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-8 June 20, 2011

Proposed 2020 Transportation Conformity Budgets

County Subarea Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Baseline EMFAC2007 9.64 25.94 10.36 44.65 2.00 8.49 2.28 7.22 3.63 15.70 7.49 18.57 5.70 11.86 5.96 11.88

Existing Measures: 

Local Reductions 0.00 0.11 0.00 0.08 0.00 0.02 0.00 0.02 0.00 0.04 0.00 0.10 0.00 0.06 0.00 0.05

State Reductions 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

New/Proposed Measures:

Local Reductions 0.27 0.18 0.19 0.13 0.04 0.03 0.04 0.03 0.09 0.06 0.24 0.16 0.16 0.10 0.13 0.09

State Reductions 1.15 7.96 2.01 19.39 0.36 3.20 0.34 2.55 0.70 5.79 0.89 5.94 0.58 3.34 0.60 3.68

Total 8.21 17.69 8.16 25.06 1.60 5.24 1.90 4.62 2.84 9.82 6.36 12.38 4.96 8.35 5.23 8.05

Budget* 8.3 17.7 8.2 25.1 1.7 5.3 2.0 4.7 2.9 9.9 6.4 12.4 5.0 8.4 5.3 8.1

*Budgets are rounded up to the nearest tenth ton (0.1).

Proposed 2023 Transportation Conformity Budgets

County Subarea Fresno Kern Kings Madera Merced San Joaquin Stanislaus Tulare

ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx ROG NOx

Baseline EMFAC2007 9.08 22.89 9.44 37.62 1.81 7.29 2.13 6.49 3.32 13.80 7.20 16.67 5.23 10.19 5.44 10.24

Existing Measures: 

Local Reductions 0.00 0.10 0.00 0.07 0.00 0.02 0.00 0.02 0.00 0.03 0.00 0.09 0.00 0.06 0.00 0.05

State Reductions 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0.00

New/Proposed Measures:

Local Reductions 0.25 0.15 0.18 0.10 0.04 0.02 0.04 0.02 0.08 0.05 0.22 0.13 0.15 0.09 0.12 0.07

State Reductions 0.88 9.15 1.43 18.86 0.26 3.34 0.27 2.92 0.53 6.33 0.71 6.52 0.43 3.65 0.46 3.93

Total 7.95 13.49 7.83 18.58 1.51 3.91 1.81 3.53 2.71 7.38 6.26 9.92 4.65 6.39 4.85 6.19

Budget* 8.0 13.5 7.9 18.6 1.6 4.0 1.9 3.6 2.8 7.4 6.3 10.0 4.7 6.4 4.9 6.2

*Budgets are rounded up to the nearest tenth ton (0.1).
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-9 June 20, 2011

Minor Technical Revisions to the PM2.5 SIP Transportation Conformity Budgets

ARB has adopted the April 2011 revisions to the PM2.5 SIP transportation conformity budgets 

for the South Coast and San Joaquin Valley. ARB staff is now proposing the following minor 

technical revisions to the PM2.5 SIP transportation conformity budgets:

 Remove the benefits for indirect source review (ISR) from the adjustments to the San 

Joaquin Valley PM2.5 conformity budgets based on U.S. EPA’s recent May 9, 2011 

action regarding Rule 9510 in the San Joaquin Valley. The San Joaquin Valley Air 

Pollution Control District adopted Rule 9510 ISR, which was intended to regulate 

facilities which attract or may attract mobile sources of air pollution. The benefit that 

the Air District included from the rule in the 2008 PM2.5 SIP will be removed for the 

conformity budget calculation.

 Remove the benefits for AB 923 (Firebaugh, 2004) from the adjustments to the South 

Coast PM2.5 conformity budgets. AB 923 expanded the types of emissions covered 

by the Carl Moyer program to include additional emissions of particulate matter and 

reactive organic gases from defined covered sources in the State. The South Coast 

Air Quality Management District included benefits from AB 923 as one of the SIP 

strategy reductions in its 2007 Air Quality Management Plan. The Air District’s latest 

SIP revision in April 2011 did not include the benefits from AB 923. ARB is adjusting 

the conformity budgets to be consistent with the Air District action.

 Correct data entry errors in the budget calculations for the South Coast and 

San Joaquin Valley.

The transportation conformity budget development worksheets are included in Tables C-3 and 

C-4, below. 
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-10 June 20, 2011

Table C-3

South Coast Air Basin

PM2.5 Transportation Conformity Emission Budget Worksheets*

(Annual Average – Tons per Day)

South Coast Air Basin

2012 2014

ROG NOx PM2.5 ROG 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

*Budgets are rounded up to the nearest ton. 
Appendix C – Description of Technical Revisions to the 

8-hour Ozone and PM2.5 SIP Transportation Conformity Budgets

Appendix C-11 June 20, 2011

Table C-4

San Joaquin Valley Air Basin

PM2.5 Transportation Conformity Emission Budget Worksheets*

(Annual Average – tpd)

County Subarea 2012 2014

PM2.5 NOx PM2.5 NOx

Fresno

Baseline Inventory 1.82 47.82 1.65 40.60

State Strategy Adjustments 0.36 11.99 0.56 9.07

Adjustments to Baseline 0.01 0.16 0.02 0.22

Budgets 1.5 35.7 1.1 31.4

Kern (SJV)

Baseline Inventory 2.98 81.58 2.63 70.28

State Strategy Adjustments 1.14 32.46 1.44 26.29

Adjustments to Baseline 0.01 0.23 0.01 0.28

Budgets 1.9 48.9 1.2 43.8

Kings

Baseline Inventory 0.59 16 0.51 13.52

State Strategy Adjustments 0.20 5.47 0.26 4.20

Adjustments to Baseline 0.00 0.05 0.00 0.06

Budgets 0.4 10.5 0.3 9.3

Madera

Baseline Inventory 0.5 12.30 0.46 10.62

State Strategy Adjustments 0.12 3.14 0.17 2.55

Adjustments to Baseline 0.00 0.05 0.01 0.07

Budgets 0.4 9.2 0.3 8.1

Merced

Baseline Inventory 1.19 29.15 1.05 24.67

State Strategy Adjustments 0.40 9.37 0.50 7.16

Adjustments to Baseline 0.01 0.11 0.01 0.14

Budgets 0.8 19.7 0.6 17.4

San Joaquin

Baseline Inventory 1.39 35.24 1.29 30.27

State Strategy Adjustments 0.36 10.73 0.46 8.58

Adjustments to Baseline 0.01 0.11 0.01 0.14

Budgets 1.1 24.5 0.9 21.6

Stanislaus

Baseline Inventory 0.84 22.25 0.76 18.69

State Strategy Adjustments 0.16 5.58 0.23 4.04

Adjustments to Baseline 0.00 0.06 0.00 0.07

Budgets 0.7 16.7 0.6 14.6

Tulare

Baseline Inventory 0.75 20.87 0.69 17.88

State Strategy Adjustments 0.13 5.19 0.21 4.05

Adjustments to Baseline 0.00 0.07 0.01 0.10

Budgets 0.7 15.7 0.5 13.8

*Budgets are rounded up to the nearest tenth ton (0.1). 
Appendix D

Adopted Rulemaking Calendar

(Note: This rulemaking calendar was included as Appendix D to the ARB staff report entitled, 

“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” and is included 

here unchanged for informational purposes.)
March 29, 2011 Appendix B 1

(Note: This rulemaking calendar was adopted in April 2011 as Appendix D to the ARB staff report entitled, 

“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” and is included here unchanged for 

informational purposes.)

APPENDIX B: Rulemaking Calendar

Table B-1

Proposed Update to 2007 State Strategy: PM2.5 SIP Measures

Agency Actions Implementation

Passenger Vehicles

Smog Check Improvements BAR 2007-2009 2008-2010; 

20131

Expanded Vehicle Retirement (AB 118) ARB/BAR 2007 2009

Modifications to Reformulated Gasoline Program ARB 2007 2010

Trucks

Cleaner In-Use Heavy-Duty Trucks ARB 2007, 2008, 

2010 2011-2015

Goods Movement Sources

Auxiliary Ship Engine Cold Ironing & Other Clean Tech

EPA/ARB/

Local

2007, 2008 2010

Cleaner Main Ship Engines and Fuel2

Fuel: 2008-

2011 2009-2015

Engines: 2008 2011

Port Truck Modernization ARB, Local 2007,2008,

2010 2008-2020

Accelerated Intro. of Cleaner Line-Haul Locomotives3EPA/ARB 2008 2012

Clean Up Existing Harbor Craft ARB 2007, 2010 2009-2018

Off-Road Equipment

Cleaner In-Use Off-Road Equipment4ARB 2007, 2010 2009

Other Off-Road Sources

New Emission Standards for Recreational Boats5ARB See notes See notes

Expanded Off-Road Recreational Vehicle Emission 

Standards5 ARB See notes See notes

Enhanced Vapor Recovery for Above-Ground Storage 

Tanks ARB 2008 2009-2016

Additional Evaporative Emission Standards5

2009 2010-2012

See notes See notes

Areawide Sources

Consumer Products Program ARB

2008 2010

2009 2013-2014

2011 2014

Pesticide Regulation DPR 2008, 2009 2009
March 29, 2011 Appendix B 2

(Note: This rulemaking calendar was adopted in April 2011 as Appendix D to the ARB staff report entitled, 

“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” and is included here unchanged for 

informational purposes.)

1

In 2010, the State Legislature improved the effectiveness of the Smog Check program 

(AB 2289), requiring the Bureau of Automotive Repair to direct older vehicles to high 

performing auto technicians and test stations for inspection and certification. This new 

program will be effective in 2013.

2 In July 2008, ARB adopted a regulation that applies to ships operating within 24 

nautical miles (nm) of the California Coastline and visiting California ports. These 

vessels must use less polluting marine distillate fuel for their main engines, auxiliary 

engines, and boilers instead of heavy fuel oil. The first phase of cleaner fuel for ship 

main engines took effect in 2009, with a second phase currently scheduled in 2012. By 

2015, the International Maritime Organization's fuel sulfur requirements for the North 

American Emission Control Area will match ARB’s phase 2 standards and extend out to 

200 miles from California Coastline.

3

In 2008, ARB awarded Prop 1B bond funds to upgrade line-haul locomotive engines 

not already accounted for by enforceable agreements with the railroads. Those cleaner 

line-hauls will begin operation by 2012. 

4Reductions begin in 2014.

5Expected action in 2013, with implementation schedules to be determined in 

rulemaking process.
(Page intentionally blank.)
Appendix E

Analysis of Environmental Impacts
Appendix E-1 June 20, 2011

Analysis of Environmental Impacts

ARB prepared an environmental analysis for the State Strategy for California's State 

Implementation Plan (SIP) for the New Federal PM2.5 and 8-Hour Ozone Standards

prior to its approval by the Board in September 2007 (State Strategy). The State Strategy 

mapped out the actions ARB would take to reduce emissions to levels designed to bring 

California into compliance with federal air quality standards. The State Strategy is available 

for review at:

http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm

and at ARB’s offices at:

1001 I Street, Sacramento, California, Room 7-45

Various measures identified in the 2007 State Strategy have been adopted by the Board since 

that time, and separate, additional environmental analyses were also prepared by ARB prior

to the adoption of each of these measures. As part of tracking the implementation of the State 

Strategy, this report quantifies the emission reductions that have been achieved since 

adoption of the 2007 State Strategy. The proposed SIP revisions do not change the emission 

levels of NOx and ROG that the Board committed to achieve by specific dates when it 

adopted the 2007 State Strategy. 

The proposed SIP revisions include four components: (1) an update to ARB’s rulemaking 

calendar for one measure, (2) updates to reasonable further progress (RFP) tables and 

associated reductions for contingency purposes, (3) updates to the transportation conformity 

budgets, and (4) updates to the actions ARB would take to identify and implement advanced 

technology control measures as allowed under section 182(e)(5) of the federal Clean Air 

Act (Act). The proposed revisions do not cause any change that has the potential to result in 

a direct physical change in the environment or a reasonably foreseeable indirect physical

change in the environment, for the following reasons. 

The updates to the rulemaking calendar reflect the current status of measures that have 

already been adopted, and changes to the expected dates by which emission reductions 

would be achieved for the agricultural tractor emission control measure. The update to the 

rulemaking calendar does not change the measure or its expected emission reductions

identified in the 2007 State Strategy. They merely change the dates by which ARB staff will 

bring this measure to the Board for proposed action by the Board. 

The updates to the RFP tables, contingency measure reductions and transportation 

conformity budgets are proposed accounting changes made to reflect the current status of 

adopted measures, better data, changes due to the recession, and methodological 

improvements to the emission inventory. These accounting changes do not change the 

strategies or commitments identified in the 2007 State Strategy to achieve specific emission

reductions by specified dates. Because no changes have been made to the strategies or the 

underlying emission reduction commitments in the 2007 State Strategy, there is no potential 

for any of the proposed SIP revisions to cause any significant adverse environmental impacts. 

The revisions to the advanced technology discussion do not alter ARB’s commitment to 

identify and implement emission reductions as required by section 182(e)(5) of the Act.