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

Release Date: March 29, 2011

Hearing Date: April 28, 2011

Air Resources Board

California Environmental Protection Agency
This document has been prepared by the staff of the California Air Resources 

Board. Publication does not signify that the contents reflect the views and 

policies of the Air Resources Board.
Table of Contents

 

California Is Meeting Its Clean Air Commitments for 2014 .............................1

The Clean Air Act Set a Process to Develop and Implement SIPs ................2

U.S. EPA Can Now Approve the PM2.5 SIPs for the South Coast and the 

San Joaquin Valley ............................................................................................3

ARB’s Clean Air Commitment is Enforceable .................................................4

The Technical Foundation for the PM2.5 SIPs is Sound ................................5

ARB Is Implementing Its Rulemaking Calendar ..............................................7

ARB Accounts for the Impact of the Recession on Goods Movement .........9

Air Quality Continues to Improve ...................................................................11

California Is Moving Forward ..........................................................................12

APPENDICIES

APPENDIX A: Descriptions of the Proposed SIP Revisions 

APPENDIX B: Rulemaking Calendar

APPENDIX C: Reasonable Further Progress Tables

APPENDIX D: Transportation Conformity Budgets

APPENDIX E: Additional Documentation

APPENDIX F: Revisions to 2007 PM2.5 and Ozone State Implementation 

Plan for South Coast Air Basin and Coachella Valley, March 

2011

APPENDIX G: Analysis of Environmental Impacts 
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March 29, 2011 1

California Is Meeting Its Clean Air Commitments for 2014

For several years, California has been implementing PM2.5 (fine particulate matter) 

State Implementation Plans (SIP) for the South Coast and San Joaquin Valley Air 

Basins. As required by the federal Clean Air Act (Act), these SIPs show how California 

plans to attain the annual PM2.5 standard by the 2014 deadline, with specific emission 

targets for each region. With a few years remaining until the attainment deadline, 

California is meeting the commitments identified in the PM2.5 SIPs, and air quality 

continues to improve. 

Figures 1 and 2 illustrate California’s progress with rulemaking completed to date and 

the last three years of SIP implementation remaining. The San Joaquin Valley meets, 

and the South Coast is 94 percent of the way towards achieving the 2014 emissions 

levels identified in their respective PM2.5 SIPs. 

In 2010, the Air Resources Board (ARB) revisited key regulations to account for the 

lower emission levels resulting from the economic downturn and provided some 

economic relief to affected industries while maintaining the 2014 emissions target. This 

is reflected in Figures 1 and 2.

Figure 1
March 29, 2011 2

Figure 2

The Clean Air Act Set a Process to Develop and Implement SIPs 

California’s primary responsibility under the Clean Air Act is clear – to develop and 

implement air quality plans to attain the National Ambient Air Quality Standards 

(NAAQS) by the required deadlines. The Act mandates a specific process for 

developing and implementing the SIPs necessary for demonstrating how the NAAQS 

will be attained. The Act specifies processes for federal sanctions if states fail to 

develop or to implement required SIPs and requires states to prepare additional SIP

revisions if a standard is not met by the deadline. 

In California, ARB and the local air districts develop and adopt SIPs based on the best 

scientific data available at the time. The SIP development process takes 2-3 years, and 

involves emissions and air quality data gathering and analysis, air quality modeling and 

documentation, control strategy development, transportation conformity budget 

development, reasonable further progress analyses, and a comprehensive public 

process before the plan is ready for consideration and approval by local districts and 

ARB. Adding to the complexity, the State and local portions must be woven together to 

reflect the respective regulatory responsibilities. 
March 29, 2011 3

Key to this process, and a defining component of the State’s SIP commitment, is the air 

quality modeling results that identify the level of emissions needed in the attainment 

year to achieve the federal standard. Air quality modeling is an analytical tool that is 

used to test a scenario of future emissions, and the associated impact on air quality, in 

order to identify a target level of emissions expected to result in attainment. The SIP is 

then designed to meet this emissions target. The modeling also provides data which 

informs the selection of the most effective control strategy.

After adoption, ARB submits the SIP to U.S. EPA for review and approval. The work of 

implementation then begins, focused on achieving the SIP target level of emissions by 

the required deadline. Once the plan is adopted, emissions accounting is the 

appropriate tool to track progress, address any shortfalls, and ensure the State is 

meeting the legal commitments contained in the plan. 

In the case where a region fails to attain a federal standard by the attainment deadline, 

Section 110 of the Act sets out a separate, sequential process that would require

U.S. EPA to direct the state to develop a new SIP with a new attainment deadline.

The Act’s step-wise approach of attainment planning, SIP implementation, and 

monitoring attainment status avoids forcing states into a perpetual planning process. 

Instead, the Act directs most of the effort towards achieving attainment through rule 

adoption and SIP implementation. New plans come into play only when an air quality 

standard is not met by the applicable deadline.

U.S. EPA Can Now Approve the PM2.5 SIPs for the South Coast and 

the San Joaquin Valley 

California is following the SIP development and implementation process mandated by 

the Act, despite the delay in federal action on the PM2.5 SIPs for the South Coast and 

San Joaquin Valley. Implementation and tracking of SIP commitments began 

immediately upon State approval of the PM2.5 SIPs. This progress report documents 

both the regulatory and air quality progress that has been made in the South Coast and 

San Joaquin Valley since the PM2.5 plans were adopted in 2007 and 2008 respectively.

This report also provides targeted revisions to the South Coast and San Joaquin Valley 

PM2.5 SIPs due to recent revisions to ARB’s rules affecting in-use trucks and buses 

and off-road construction equipment. These SIP revisions are limited to an updated 

calendar of ARB rulemaking, updates to the Reasonable Further Progress tables and 

associated reductions for contingency purposes, and adjustments to the transportation 

conformity budgets. 

In a separate action on March 4, 2011, the South Coast adopted revisions to their 

PM2.5 and Ozone SIP for the South Coast Air Basin and Coachella Valley. These 

revisions are contained in Appendix F. They update the implementation status of the 
March 29, 2011 4

district’s control measures to meet the PM2.5 attainment date, revise the control 

measure adoption schedule, and modify the District’s emissions reduction commitment

to reflect improvements to the off-road emissions estimates for 2014.

Together, these submittals should provide what U.S. EPA needs to fully approve the 

PM2.5 plans for the South Coast and San Joaquin Valley.

ARB’s Clean Air Commitment is Enforceable 

While California's emissions levels have in some cases declined substantially since 

2007 as a result of the economic recession, ARB continues to fully implement the 

PM2.5 SIPs. 

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

 Actual emission decreases 

As a result of the recession, actual emission decreases moved California closer to the 

emissions levels needed for attainment in 2014. The recession has reduced economic 

activity and emissions, most notably in the goods movement sector. This has allowed 

ARB to maintain the State’s SIP commitments in the South Coast and San Joaquin 

Valley while also providing some near-term economic relief to affected industries. 

As the economy recovers, ARB will continue to track emission trends to ensure the 

2014 emission targets are met. If future emissions were to exceed the SIP target, the 

State's commitment could be made up with additional controls, incentive programs, or 

other programs to bring emissions down to the necessary levels. A discussion of how 

ARB accounted for the recession is found later in this report.

State law1assigns ARB the primary responsibility to ensure California's compliance with 

the federal Clean Air Act. Traditionally, ARB shares that responsibility with local air 

districts through defined SIP commitments at both the State and local level. In the case 

of the PM2.5 SIP, there is also an expectation on the part of the State that the federal 

government provide additional emission reductions based on the U.S. EPA’s authority 

to regulate locomotives and other national sources of air pollution. 

 

1 California Health and Safety Code section 39003.
March 29, 2011 5

However, if there is a shortfall in a SIP due to lack of federal action, California will be 

required to achieve additional emission reductions. For example, the SIP for the South 

Coast calls for reductions of 10 tons per day of oxides of nitrogen (NOx) from sources 

U.S. EPA or other federal agencies regulate. If the federal government does not 

provide the expected emission reductions, ARB still has the obligation that the 

emissions targets specified in the SIP are met by the required deadline. 

The Technical Foundation for the PM2.5 SIPs is Sound

ARB exercised its responsibility at the time of SIP development, public review, and 

Board adoption, to ensure that the PM2.5 attainment demonstrations met all applicable 

Clean Air Act requirements, used the best information available at the time, and 

identified a path to attainment that is technically achievable. ARB’s SIP commitment to 

reduce emissions to the levels necessary for PM2.5 attainment relies on the strong 

scientific foundation provided in the SIPs for both the South Coast Air Basin and the 

San Joaquin Valley. 

In a recent court decision2, the Court called upon U.S. EPA to exercise its affirmative 

duty to ensure the State’s plan is adequate for attainment of the applicable federal 

standard. Given the strong science supporting California's PM2.5 SIPs, U.S. EPA's 

assessment of SIP adequacy should focus on the State's demonstrated progress in 

implementing the adopted plan and achieving real world reductions in air pollution. 

Adopted SIPs should not be set aside unless there is compelling scientific evidence that 

the adopted attainment demonstration is substantially flawed, taking into account the 

unavoidable uncertainties in emission estimates, air quality modeling, and other 

technical elements.

In the case of the PM2.5 SIPs for the South Coast Air Basin and San Joaquin Valley, 

there has been no significant change to the fundamental science and air quality 

modeling used to set the 2014 emissions targets. The SIP modeling remains in 

accordance with U.S. EPA requirements and should be approved by U.S. EPA. 

Similarly, the overall control strategy is unchanged and in the process of being 

implemented. Initiating new air quality modeling to reassess the existing attainment 

demonstration would serve no practical purpose. The biggest change since the PM2.5 

SIPs were adopted is the unanticipated slowdown in economic growth and what it 

means for PM2.5 precursor emissions in 2014. An emissions accounting that 

incorporates the impacts of the recession, future emission changes, and the benefits of 

new SIP measures is the appropriate approach to assess the adequacy of the PM2.5 

SIPs now close to final implementation. 

 

2 U. S. Court of Appeals for the Ninth Circuit in Association of Irritated Residents, et al. v. U.S. EPA, filed 

February 2, 2011.
March 29, 2011 6

Development and adoption of the PM2.5 SIPs in the South Coast and San Joaquin 

Valley followed the mandated process, and resulted in a resource-intensive, 3-year 

technical effort with a public process that stretched over a year. The end result is a plan 

whose technical underpinnings remain sound even as new information has become 

available during SIP implementation. While new emission forecasts are included in the 

accounting for progress towards the 2014 emissions target, the target itself should not 

change. 

Air quality modeling is an analytical tool that is used to test a scenario of future 

emissions, and the associated impact on air quality, in order to identify a target level of 

emissions expected to result in attainment of an air quality standard. The air quality

modeling contained in the PM2.5 SIPs is built on the results of the multimillion dollar air 

quality studies conducted in central California, including the $50 million California 

Regional Particulate Air Quality Study (CRPAQS) and the Central California Ozone 

Study (CCOS). 

The ability of an air quality model to predict the attainment year emission targets relies 

on adequate model performance in the base year. Small changes in base year 

emissions would not substantially change the fundamental relationship between 

emissions and measured air quality in the base year modeling. The recession does not 

impact the SIP base year modeling since both regions used base years prior to the 

recession. The new emissions inventory data primarily impact current emissions and 

estimates of future emissions as the economy recovers and do not substantially change 

the total regional emissions in the base years. Therefore, the air quality modeling and 

the 2014 emissions targets should be approved by U.S. EPA. 

California’s development and implementation of the PM2.5 SIPs in the South Coast and 

San Joaquin Valley illustrates the process mandated by the Act to reach attainment in 

2014. In developing and then adopting the 2007 and 2008 PM2.5 SIPs for the South 

Coast and San Joaquin Valley, the ARB and local air districts provided a technically 

complete attainment plan. Once the plans were adopted, California's focus 

appropriately turned to SIP implementation. For its part, U.S. EPA’s sulfur in marine 

fuels rule has also advanced PM2.5 reductions in the South Coast. The SIP technical 

foundation meets U.S. EPA requirements, control measures are being implemented, 

and progress is being made. As a result, a modeling update at this juncture is neither 

necessary nor appropriate.
March 29, 2011 7

ARB Is Implementing Its Rulemaking Calendar 

A key component of SIP implementation is the rulemaking calendar. ARB adopted a 

SIP revision (the 2007 State Strategy) that mapped out the actions it would take to 

reduce PM2.5 direct and precursor emissions to levels designed to bring California 

nonattainment areas into compliance with federal health-based air quality standards. 

ARB had initiated rule development for several measures even before the Board 

adopted the State Strategy in late 2007. This work continues, with several State and 

local district measures scheduled for adoption between now and 2014. The respective 

air district plans provide information about the local efforts to adopt and implement local 

control measures. Table 1 provides an update on the status of SIP measures in the 

2007 State Strategy.

The 2007 State Strategy identifies a comprehensive set of State control strategies that 

support attainment through a combination of technologically feasible, cost-effective, and 

far reaching measures. ARB actions to date, together with rules adopted by the South 

Coast and San Joaquin Valley air districts, will bring the two regions within 94 percent 

and 100 percent of the emission levels needed to reach attainment in 2014 in the South 

Coast and San Joaquin Valley, respectively. Some of the most important adopted State

regulations include:

 Cleanup of the existing truck fleet statewide

 Repowering or replacing older, dirtier off-road construction vehicles, and 

installing exhaust retrofits

 Lower sulfur limits on fuels used by ships in California waters

 Control of emissions from goods movement sources

 Smog Check improvements
March 29, 2011 8

Table 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 

Standards

5 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

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.

5 Expected action in 2013, with implementation schedules to be determined in rulemaking process.
March 29, 2011 9

Tables 2 and 3 show the progress towards meeting the State’s enforceable SIP 

commitment in each region. The tables include the benefits of local and State controls 

for each PM2.5 precursor pollutant. To maintain consistency with how each air district 

displays progress in their documents, the South Coast table is displayed in equivalents

of nitrogen oxides (NOx), while the San Joaquin Valley table is in PM2.5 equivalents. 

NOx and PM2.5 equivalent emissions are calculated using weighting factors from the 

SIP technical analyses to arithmetically combine the precursor pollutants that form 

PM2.5. The factors are necessary since the relative effectiveness of each pollutant in 

reducing atmospheric PM2.5 varies by pollutant and region. From a technical 

perspective, it does not matter which pollutant is used as the equivalence benchmark to 

illustrate progress since the same scientific data is applied regardless of how 

equivalency is expressed.

Table 2

Table 3

San Joaquin Valley Air Basin

Progress to Date with Adopted Rules

annual average tons per day

SOx PM2.5 NOx PM2.5 eq.

2005 Inventory 26 86 575 176

2014 SIP Emissions Target 24 63 291 119

2014 Forecast with Adopted Rules 21 65 298 119

% progress 201% 90% 98% 100%

ARB Accounts for the Impact of the Recession on Goods Movement

The recession has imposed significant downward pressure on economic activity in the 

State. In order to meet their bottom line and maximize production output, many 

businesses have cut back debt, reduced employment, extended workforce hours, and 

sold assets, including part of their motor vehicle fleets. In some sectors, these 

adjustments resulting from the recession are expected to continue for some time, 

extending beyond the 2014 attainment date.

SOx PM2.5 ROG NOx NOx eq.

2002 Inventory 53 99 844 1093 3216

2014 Emissions Target 20 86 474 460 1810

2014 Forecast with Adopted Rules 20 87 485 530 1894

% progress 100% 92% 97% 89% 94%

South Coast Air Basin

Progress to Date with Adopted Rules

annual average tons per day
March 29, 2011 10

Two of the sectors hit the hardest by the recession are the construction industry and 

goods movement, including the trucking and shipping industries. These impacts, as 

well as recovery scenarios, were reflected in ARB’s 2010 amendments to the statewide 

truck and construction regulations and are reflected in the goods movement categories 

included in this report. The one exception is the locomotive emissions estimate. ARB 

staff is still in the process of incorporating the latest information on locomotive activity 

into programs for reducing regional emissions and localized impacts. 

In the 2010 assessment of the impacts of the recession, ARB staff evaluated a variety 

of sources of information including economic forecasts, fuel tax reports, highway 

performance monitoring data, equipment financial filing records, and vehicle sales 

information. The data indicated the recession impacted mobile sources in three ways. 

First, the recession reduced vehicle activity. Overall, trucking activity in California, 

measured by fuel usage, decreased by nearly 20 percent between 2007 and 2010. 

Construction-related activity declined by 50 percent between 2005 and 2010. These 

declines were dramatic, and in many cases unprecedented. 

Second, the depth of the recession, being much more severe than economic recessions 

of the past 70 years, affected the forecast rate of future economic growth. Several 

economic forecasting groups including the University of California – Los Angeles, the 

University of the Pacific, and the California Department of Finance forecast that 

economic recovery and expansion, and rising employment levels will occur relatively

slowly over the next five years. ARB used these estimates to reduce its forecasted 

vehicle activity levels from previously anticipated levels. 

Third, the recession had a major impact on new vehicle sales, which in many cases fell 

by 80-90 percent from the peak levels seen in 2005-2007. Sales volumes are projected 

to increase gradually, and are not forecast to reach previous levels for several years. 

This has also reduced the penetration of the newest, cleanest vehicles into the 

California market, leaving fleets older than they would have been without the recession. 

This economic outlook was used in the 2010 review of the statewide on-road truck 

rules, and resulted in a 2010 emissions inventory that is about 35 percent lower than 

estimated when the original rules were adopted in 2008. Similarly, the updated off-road 

inventory calculated during development of the construction rule is about 80 percent 

lower than previously estimated, with half the change attributable to the recession and 

half attributable to new emissions data and analysis. 

When ARB revised the statewide truck and off-road fleet rules in 2010, the new 

inventory projections were used to design the timetable and regulatory provisions in 

such a way that emission benefits are preserved as economic growth picks up and full 

rule implementation phases in. The revised rules provide credits for fleets that have 

downsized to account for the recession, while allowing for a delay of additional capital 

investments until 2016. The rules provide incentives for early vehicle retrofit and 

turnover to achieve emissions reductions necessary for 2014, while offering some 
March 29, 2011 11

economic relief. The revised rules will still provide the emissions reductions necessary 

to meet air quality standards, but do so at a lower cost. Concurrently, ARB retained and 

expanded the benefits of the drayage truck rule to protect communities near ports and 

rail yards.

The improvements would not significantly change the inventories for trucks, construction 

equipment, and ocean going vessels in years prior to the recession. The changes are 

small in the context of the entire emissions inventory, consequently the total regional 

SIP base year inventories need not be changed. The new information indicates that the 

2014 economic activity estimates made prior to the recession are too high. Looking 

forward, revised economic activity forecasts and improvements to future emission

estimates from these source categories are reflected in the emissions accounting to 

assess progress toward the SIP commitments, in the updated RFP demonstration, and 

in new conformity budget calculations.

Air Quality Continues to Improve

As a result of SIP implementation efforts at the local and State level, air quality is 

improving in both the South Coast and San Joaquin Valley regions. 

The South Coast has seen dramatic improvement in PM2.5 air quality, with a 37 percent 

decrease in the basin-wide annual average design value over the last eight years. This 

decrease has occurred despite the inclusion of a new high site monitor in Mira Loma 

(Riverside County) in 2006. Based on data in 2009, sites outside the Riverside area 

already meet or are close to meeting the annual standard. While final South Coast data 

for 2010 are not yet available, indications are that concentrations have continued to 

further decline and that only the site at Mira Loma now exceeds the annual standard. 

The San Joaquin Valley has also experienced an improvement in PM2.5 air quality, 

although the progress is not as uniform across the region. The biggest decreases 

occurred in the northern and central part of the Valley where the design values for 

various monitors decreased 25 to 37 percent between 2001 and 2010. Today, sites in 

the northern and central Valley meet or are close to meeting the annual standard. The 

southern San Joaquin Valley, which includes the Bakersfield area, has also shown 

improvement, with annual design values decreasing 10 to 20 percent. 

Air quality design values reflect a three-year average which is used for comparison to 

federal standards. However, evaluating multiple measures of air quality can provide a 

broader picture of overall air quality progress. For example, individual year annual 

PM2.5 values for 2009 and 2010 throughout the Valley show significant improvement. 

In 2010, only two of the twelve sites in the Valley (Corcoran and Bakersfield) recorded 

annual concentrations that exceed the federal air quality standard. Peak 24-hour PM2.5 

concentrations have also declined significantly, dropping over 30 percent since 2001. 

The Air Quality Index (AQI) is another measure that is used to evaluate daily air quality 
March 29, 2011 12

conditions. Between 2001 and 2010, the number of days considered unhealthy under 

the AQI has been cut in half.

California Is Moving Forward

California has made tremendous progress in cleaning the air over the past several 

decades, providing environmental leadership and meeting Clean Air Act requirements.

As California’s PM2.5 SIPs are being implemented to meet a 2014 deadline, additional 

SIPs will need to be developed for other air quality standards. ARB is working with local 

air districts to develop new SIPs in 2012 that are required to address the daily 24-hour 

PM2.5 federal air quality standard by 2017. U.S. EPA's anticipated promulgation of a 

more stringent ozone standard will trigger a new round of SIPs with attainment 

deadlines well beyond 2020. As these efforts proceed, ARB will use the most recent 

emissions inventory data from category-specific rules, refine existing inventory models, 

and conduct additional air quality modeling. 

As required by the federal Clean Air Act, the South Coast and San Joaquin Valley 

PM2.5 SIPs show how California plans to attain the annual PM2.5 standard by the 2014 

deadline, with specific emission targets for each region. With three years remaining 

until the attainment deadline, California is meeting the commitments identified in the 

PM2.5 SIPs, and air quality continues to improve. With California’s progress on 

rulemaking the San Joaquin Valley meets, and the South Coast is 94 percent of the way 

towards achieving the emissions levels identified in their respective PM2.5 SIPs for 

attainment in 2014. The SIPs’ technical foundation is sound, control measures are 

being implemented, and progress is being made. The targeted revisions to the South 

Coast and San Joaquin Valley PM2.5 SIPs should provide what U.S. EPA needs to fully 

approve the PM2.5 plans for the South Coast and San Joaquin Valley.
APPENDICIES
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 

March 29, 2011 Appendix A 1

APPENDIX A: Descriptions of the Proposed SIP Revisions

Updates to ARB’s Rulemaking Calendar

ARB staff is proposing updates to ARB’s Rulemaking Calendar to reflect the current 

status of adopted PM2.5 measures and changes to expected action dates for three of 

these measures: new emission standards for recreational boats, expanded off-road

recreational vehicle emission standards, and additional evaporative emission standards. 

ARB proposes to modify the action date for all three measures from the existing range 

of 2009-2010 to 2013. ARB action on these measures in this timeframe will allow

implementation to occur by the 2014 attainment date. ARB’s commitments to achieve 

emission reductions by specified dates, as identified in the 2007 State Strategy, remain 

unchanged and are not altered by the proposed changes to ARB’s rulemaking calendar. 

Appendix B provides the PM2.5 SIP revision for the updated rulemaking calendar. 

Reasonable Further Progress

The federal Clean Air Act (Act) requires that SIPs show there will be steady progress in 

reducing emissions during the years leading to the attainment date, called reasonable 

further progress (RFP). ARB staff is proposing updates to the RFP tables to reflect the 

current status of adopted measures and account for changes due to the recession. 

These revisions are necessary to reflect current forecasted emissions as a result of the 

impacts of the recession on key source categories in the SIPs. Appendix C provides the 

SIP revision for the updated RFP tables.

The Act also requires attainment plans to identify “contingency measures” to be 

implemented if nonattainment areas fail to meet RFP requirements or to attain the 

federal air quality standards on time. These contingency measures are to take effect 

without further ARB or air district action, and thus must be measures that have already 

been adopted when the SIP is submitted to U.S. EPA. 

For PM2.5, U.S. EPA requires that the RFP plan show generally linear progress for the 

precursor pollutants identified in the attainment demonstration. For the San Joaquin 

Valley this includes direct PM2.5, NOx, and SOx. For the South Coast Air Basin it also 

includes ROG. Since both the San Joaquin Valley and South Coast Air Basin show 

attainment in 2014, 2009 and 2012 are the milestone years for RFP. ARB is providing 

contingency measures for the 2012 RFP milestone and 2014 attainment years as 

appropriate. 

ARB is updating the RFP milestone emission levels to reflect the impact of the 

recession and recent changes to the in-use heavy-duty truck and off-road equipment 
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 

March 29, 2011 Appendix A 2

rules, and also the ocean-going vessels rule for the South Coast. Appendix C Tables 1 

and 2 display projected emission levels in each of the RFP years, showing continuous 

progress towards the attainment levels for the San Joaquin Valley and the South Coast 

Air Basin, respectively. The RFP levels in both areas meet U.S. EPA requirements for 

demonstrating generally linear progress. 

For the San Joaquin Valley, the estimates of emission levels in the RFP milestone years 

consider baseline emissions and emission reductions accomplished by District adopted 

rules. Approximately one year’s worth of RFP reductions are reserved from existing

emission reductions for contingency purposes for NOx and SOx in 2012. For PM2.5, 

SOx reductions that are in excess of those needed to meet RFP and contingency are 

reserved for PM2.5 contingency purposes. 

For the South Coast, emission estimates for the milestone years considered baseline 

emissions, emission reductions from ARB adopted rules, and emission reductions 

accomplished by District adopted rules. All existing emission reductions are credited 

towards meeting the RFP milestones, with no reductions withheld for contingency 

purposes. This is appropriate given recent air quality progress in the South Coast. 

For the 2014 attainment year, the additional emission reductions accrued in 2015 from 

baseline emission reductions are relied upon to meet the contingency requirements for 

both the San Joaquin Valley and the South Coast.

 

Updates to the Transportation Conformity Budgets

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

federal annual PM2.5 standard for the South Coast and San Joaquin Valley and 

establish a trading mechanism that will ensure that the impact of on-road emissions will 

be consistent with the attainment demonstration in future years. The basis for the 

trading mechanism is the SIP attainment modeling which established the relative 

contribution of each PM2.5 precursor pollutant. These updates account for the action 

taken by the Board in December to amend the truck and bus regulations to include 

better data and improvements to the emissions inventory, and reflects the current 

rulemaking calendar. Appendix D provides the SIP revision and description of the 

trading mechanism.

The Act requires metropolitan planning organizations (MPO) to demonstrate that their 

regional transportation plans (RTP) and transportation improvement programs (TIP) are 

consistent with progress toward and attainment of the NAAQS. 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, is called a "motor vehicle emissions 
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 

March 29, 2011 Appendix A 3

budget.” 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 A-1 and A-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 continues to be based on the activity data (e.g. 

vehicle miles travelled) provided by the SIPs. 

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

approach used to develop the originally submitted budgets. Following is an example of 

how the line item adjustment is calculated and used to develop the conformity budgets. 

This example reflects the derivation of the 2014 NOx budget for South Coast Air Basin.

 The combined NOx emissions from medium and heavy heavy-duty trucks, school buses 

and other buses are retrieved from the baseline EMFAC2007 SIPs inventory (145 tpd 

NOx) and the new truck inventory (132 tpd NOx). 

 The difference between these emissions is calculated (145 tpd – 132 tpd = 13 tpd NOx).

 13 tpd NOx reflects the difference between the SIPs baseline inventory and the new 

truck inventory. 

 13 tpd is then added to the emission reductions in CY 2014 that were already identified 

in the SIPs from State and local strategies, including: Smog Check improvements and 

AB 923 Light and Medium-Duty High-Emitter Identification programs (13 tpd + 0.7 tpd = 

13.7 tpd NOx)

 13.7 tpd NOx is the total “State Strategy Adjustments” and is then entered into the 

conformity worksheet 

The transportation conformity budget development worksheets are included in Tables 

A-1 and A-2 below, with the proposed SIPs budgets found in Appendix D. 

Note that the “Adjustments to Baseline” line item originally included benefits for adopted 

regulations for solid waste collection and public fleet vehicles, heavy duty chip re-flash, 

and heavy duty truck idling, since the impacts of these regulations were not included in 

EMFAC2007. The benefits of these regulations are now reflected in the new truck and 

bus inventory baseline, and, therefore, are no longer included as a line item adjustment.
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 

March 29, 2011 Appendix A 4

The remaining “Adjustments to Baseline” consist of reductions from AB 1493 (Pavley) 

and benefits from the on-road portion of the Carl Moyer program.

Table A-1

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 -3.8 -21.2 -1.2 -9.2 -13.7 -2.7

Adjustments to Baseline -0.4 -1.2 -0.1 -0.6 -1.3 -0.2

Budget 159 329 37 137 291 35

*Budgets are rounded up to the nearest ton. 
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 

March 29, 2011 Appendix A 5

Table A-2

San Joaquin Valley Air Basin

PM2.5 Transportation Conformity Emission Budget Worksheets*

(Annual Average – Tons per Day)

County 2012 2014

PM2.5 NOx PM2.5 NOx

Fresno

Baseline Inventory 1.82 47.82 1.65 40.6

State Strategy Adjustments 0.29 11.61 0.54 9.07

Adjustments to Baseline 0.01 0.35 0.02 0.29

Budget 1.6 35.9 1.1 31.3

Kern (SJV)

Baseline Inventory 2.98 81.58 2.63 70.28

State Strategy Adjustments 1.02 31.77 1.42 26.29

Adjustments to Baseline 0.01 0.57 0.01 0.40

Budget 2.0 49.3 1.3 43.6

Kings

Baseline Inventory 0.59 16.00 0.51 13.52

State Strategy Adjustments 0.18 5.33 0.25 4.20

Adjustments to Baseline 0.00 0.12 0.00 0.09

Budget 0.5 10.6 0.3 9.3

Madera

Baseline Inventory 0.50 12.30 0.46 10.62

State Strategy Adjustments 0.10 3.04 0.17 2.55

Adjustments to Baseline 0.00 0.10 0.01 0.09

Budget 0.5 9.2 0.3 8.0

Merced

Baseline Inventory 1.19 29.15 1.05 24.67

State Strategy Adjustments 0.35 9.11 0.49 7.16

Adjustments to Baseline 0.01 0.23 0.01 0.18

Budget 0.9 19.9 0.6 17.4

San Joaquin

Baseline Inventory 1.39 35.24 1.29 30.27

State Strategy Adjustments 0.32 10.51 0.45 8.58

Adjustments to Baseline 0.01 0.26 0.01 0.20

Budget 1.1 24.5 0.9 21.5

Stanislaus

Baseline Inventory 0.84 22.25 0.76 18.69

State Strategy Reductions 0.13 5.42 0.22 4.04

Adjustments to Baseline 0.00 0.15 0.00 0.10

Budget 0.8 16.7 0.6 14.6

Tulare

Baseline Inventory 0.75 20.87 0.69 17.88

State Strategy Adjustments 0.11 5.05 0.20 4.05

Adjustments to Baseline 0.00 0.16 0.01 0.14

Budget 0.7 15.7 0.5 13.7

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

March 29, 2011 Appendix B 1

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 

Standards

5 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
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 

March 29, 2011 Appendix B 2

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.
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 

March 29, 2011 Appendix C 1

APPENDIX C: Reasonable Further Progress Tables

Table C-1

San Joaquin Valley Air Basin

PM2.5 Reasonable Further Progress

Direct PM2.5

(annual average, tpd)

2005 2009 2012 2014

Linear Benchmark 86 76 68 63

Estimated Emissions 86 73 69 63

Contingency (see SOx) *NA NA 0 NA

RFP Level 86 73 69 63

NOx 

(annual average, tpd)

2005 2009 2012 2014

Linear Benchmark 575 449 354 291

Estimated Emissions 575 381 328 291

Contingency NA NA 26 NA

RFP Level 575 381 354 291

SOx 

(annual average, tpd)

2005 2009 2012 2014

Linear Benchmark 26 25 24 24

Estimated Emissions 26 23 20 21**

Contingency

(for SOx and PM2.5) NA NA 3 NA

RFP Level 26 23 23 24

*NA: Not applicable

** Note: As a result of control measures already adopted to date, the 2014 RFP 

target for SOx has already been surpassed.
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 

March 29, 2011 Appendix C 2

Table C-2

South Coast Air Basin

PM2.5 Reasonable Further Progress

Direct PM2.5

(annual average, tpd)

2002 2009 2012 2014

Linear Benchmark 99 91 88 86

Estimated Emissions 99 89 89 86

Contingency *NA NA 0 NA

RFP Level 99 89 89 86

NOx 

(annual average, tpd)

2002 2009 2012 2014

Linear Benchmark 1093 724 566 460

Estimated Emissions 1093 677 582 460

Contingency NA NA 0 NA

RFP Level 1093 677 582 460

ROG

(annual average, tpd)

2002 2009 2012 2014

Linear Benchmark 844 628 534 474

Estimated Emissions 844 563 514 474

Contingency NA NA 0 NA

RFP Level 844 563 514 474

SOx 

(annual average, tpd)

2002 2009 2012 2014

Linear Benchmark 53 34 26 20

Estimated Emissions 53 43 26 20

Contingency NA NA 0 NA

RFP Level 53 43 26 20

*NA: Not applicable
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 

March 29, 2011 Appendix D 1

APPENDIX D: Transportation Conformity Budgets

Table D-1

South Coast Air Basin

Proposed PM2.5 Transportation Conformity Emission Budgets*

(Annual Average – Tons per Day)

2012 2014

ROG NOx PM2.5 ROG NOx PM2.5

South Coast Air Basin 159 329 37 137 291 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.
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 

March 29, 2011 Appendix D 2

Table D-2

San Joaquin Valley Air Basin

Proposed PM2.5 Transportation Conformity Emission Budgets*

(Annual Average – Tons per Day)

County 2012 2014

PM2.5 NOx PM2.5 NOx

Fresno 1.6 35.9 1.1 31.3

Kern (SJV) 2.0 49.3 1.3 43.6

Kings 0.5 10.6 0.3 9.3

Madera 0.5 9.2 0.3 8.0

Merced 0.9 19.9 0.6 17.4

San Joaquin 1.1 24.5 0.9 21.5

Stanislaus 0.8 16.7 0.6 14.6

Tulare 0.7 15.7 0.5 13.7

*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.
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 

March 29, 2011 Appendix E 1

APPENDIX E: Additional Documentation

Appendix E includes additional documentation and data supporting this Progress Report 

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

methodology, supporting data for the progress Tables 2 and 3 found in the body of the

report, and information on how ARB staff accounted for the impacts of the recession

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 

emissions 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 show the impact of the recession and the benefit of 

the regulations ARB and the local air districts have approved since the PM2.5 SIPs 

were adopted. The approach looks like

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

Where: 

Emissions Inventory = Amount of PM2.5 and PM2.5 precursor 

 emissions the base line

Emission Reductions 

Achieved

= Amount of emissions that have been 

 reduce either through adopted 

 regulations or actual emission decreases 

 due to the recession

Remaining Emissions = The PM2.5 and PM2.5 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 emission target 

derived from air quality modeling. It also has the advantage of explicitly showing the 

impacts of both the regulatory actions and the recession that an emissions accounting 

that looks just at regulatory reductions does not.
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 

March 29, 2011 Appendix E 2

Progress Details

The following series of tables provide additional documentation for Tables 2 and 3,

showing progress to date for both the South Coast and San Joaquin Valley.

South Coast Air Basin

2014 Progress to Date on ARB Rules

NOx Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Smog Check Improvements (BAR) 134.2 134.2 131.6

Cleaner In-Use Heavy-Duty Trucks & Buses 136.0 151.2 132.6

Cleaner In-Use Off-Road Equipment (over 25hp) 96.9 28.0 27.5

Ship Auxiliary Engine Cold Ironing & Clean Tech. 37.2 23.7 15.6

Cleaner Main Ship Engines and Fuel - Main Engines 33.4 38.5 20.9

Accelerated Intro. Of Cleaner Line-Haul Locomotives 18.3 18.3 18.3

Clean Up Existing Harbor Craft 15.7 15.2 11.1

Cargo Handling Equipment 5.2 3.2 3.2

New Emission Standards for Recreational Boats 11.0 11.0 11.0

Co-Benefits from Greenhouse Gas Reduction 

Measures 0.0 0.0 0.0

All other local, state, and federal emissions 165 166 159

Total 2014 forecast with rules adopted to date 653 589 530

ROG Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Smog Check Improvements (BAR) 132.1 132.1 123.5

Cleaner In-Use Heavy-Duty Trucks & Buses 10.2 8.7 5.4

Cleaner In-Use Off-Road Equipment (over 25hp) 13.4 2.6 2.5

Ship Auxiliary Engine Cold Ironing & Clean Tech. 0.7 0.9 0.7

Cleaner Main Ship Engines and Fuel - Main Engines 0.2 1.9 1.4

Accelerated Intro. Of Cleaner Line-Haul Locomotives 2.3 2.3 2.3

Clean Up Existing Harbor Craft 0.7 1.2 1.1

Cargo Handling Equipment 0.6 0.3 0.3

New Emission Standards for Recreational Boats 37.9 37.9 37.9

Expanded Off-Road Rec. Vehicle Emission Standards 6.7 6.7 6.7

Consumer Products Program 102.6 102.6 96.7

All other local, state, and federal emissions 221 206

Total 2014 forecast with rules adopted to date 518 485
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 

March 29, 2011 Appendix E 3

PM2.5 Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Smog Check Improvements (BAR) 7.8 7.8 7.5

Cleaner In-Use Heavy-Duty Trucks & Buses 5.8 6.0 3.4

Cleaner In-Use Off-Road Equipment (over 25hp) 4.9 1.3 1.3

Ship Auxiliary Engine Cold Ironing & Clean Tech. 0.6 0.5 0.4

Cleaner Main Ship Engines and Fuel - Main Engines 2.6 3.9 0.4

Accelerated Intro. Of Cleaner Line-Haul Locomotives 0.7 0.7 0.7

Clean Up Existing Harbor Craft 0.7 0.6 0.4

Cargo Handling Equipment 0.1 0.1 0.1

All other local, state, and federal emissions 74 73

Total 2014 forecast with rules adopted to date 95 87

SOx Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Cleaner In-Use Heavy-Duty Trucks & Buses 0.3 0.3 0.3

Ship Auxiliary Engine Cold Ironing & Clean Tech. 1.1 1.1 0.8

Cleaner Main Ship Engines and Fuel - Main Engines 20.7 38.7 1.7

All other local, state, and federal emissions 21 17

Total 2014 forecast with rules adopted to date 61 20
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 

March 29, 2011 Appendix E 4

San Joaquin Valley Air Basin

2014 Progress to Date on ARB Rules

NOx Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Smog Check Improvements (BAR) 41 41.2 40.5

Cleaner In-Use Heavy-Duty Trucks & Buses 156.9 111.3 110.2

Cleaner In-Use Off-Road Equipment (over 25hp) 31.4 13.7 13.4

Accelerated Intro. Of Cleaner Line-Haul 

Locomotives 19.9 19.9 19.9

New Emission Standards for Recreational Boats 3.5 3.5 3.5

All other local, state, and federal emissions 123 110

Total 2014 forecast with rules adopted to date 313 298

PM2.5 Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Smog Check Improvements (BAR) 2.5 2.5 2.4

Cleaner In-Use Heavy-Duty Trucks & Buses 6.2 4.3 2.6

Cleaner In-Use Off-Road Equipment (over 25hp) 1.4 0.6 0.6

Accelerated Intro. Of Cleaner Line-Haul 

Locomotives 0.5 0.5 0.5

All other local, state, and federal emissions 64 59

Total 2014 forecast with rules adopted to date 72 65

SOx Emissions (tpd)

SIP Current

2014 

Baseline

New 2014 

Baseline

2014 

Remaining 

Emissions

Cleaner In-Use Heavy-Duty Trucks & Buses 0.3 0.2 0.2

Cleaner In-Use Off-Road Equipment (over 25hp) 0.0 0.0 0.0

All other local, state, and federal emissions 24 21

Total 2014 forecast with rules adopted to date 24 21
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 

March 29, 2011 Appendix E 5

Assessing the Impacts of the Recession on Good 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 severe 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 its 

impact.

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

a fast and slow recovery scenario to bound the recovery possibilities. 

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 by several years yielded the 2017 recovery 

date assumed for the fast recovery scenario. 

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 a reasonable bound of possible recoveries, 

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

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.
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 

March 29, 2011 Appendix E 6

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 a revised population, 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 progress report required emission estimates for years and pollutants (SOx and 

ROG) that were not needed for the 2010 rulemaking. 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. 

2006 2008 2010 2012 2014 Growth Factor

Historical Forecast

Historical Average Growth

Recession

Fast

Slow

Average

Recovery

1.0
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 

March 29, 2011 Appendix E 7

This progress report required emission estimates for years and pollutants (SOx, ROG 

and total organic gases (TOG)) that were not needed for the 2010 rulemaking. 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 PM2.5 SIP included vessel-specific data, 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 PM2.5 SIP CHE emissions inventory to 

account for the new data.

The inventory used for the 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 emissions inventories. This new 

information 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 workshop, emissions for PM and NOx emissions are approximately 20 percent 

and 27 percent lower, respectively. 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 
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 

March 29, 2011 Appendix E 8

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

20%. 

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.
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 

March 29, 2011 Appendix F 1

APPENDIX F: Revisions to 2007 PM2.5 and Ozone State 

Implementation Plan for South Coast Air Basin and Coachella Valley, 

March 2011















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 

March 29, 2011 Appendix G 1

APPENDIX G: 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 (document 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). 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. 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 progress report quantifies the emission reductions that have been achieved since 

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

emissions levels of NOx, ROG, SOx, and direct PM2.5 that the Board committed to 

achieve by specific dates when it adopted the 2007 State Strategy. 

The proposed SIP revisions include three components: (1) updates to ARB’s rulemaking 

calendar, (2) updates to reasonable further progress (RFP) tables and associated 

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

budgets. (See Appendix A for further descriptions of the revisions.) 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 action dates for three measures 

that have not yet been adopted. For these measures, the updates to the rulemaking 

calendar do not change the measures or their expected implementation dates identified 

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

these measures to the Board for proposed action by the Board. 

The updates to the RFP tables 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 emissions 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.