State of California 

Staff Report 

Analysis of the San Joaquin Valley 

2008 PM2.5 Plan 

Release Date: May 7, 2008 

Scheduled for Consideration: May 22-23, 2008 

 

California Environmental Protection Agency 

AIR RESOURCES BOARD 
 

This document has been reviewed by the staff of the California Air Resources Board 

and approved for publication. Approval does not signify that the contents necessarily 

reflect the views and policies of the Air Resources Board, nor does the mention of trade 

names or commercial products constitute endorsement or recommendation for use. 

Electronic copies from this document are available for download from the Air Resources 

Board’s Internet site at: http://www.arb.ca.gov/planning/sip/sjvpm25/sjvpm25.htm. 

In addition, written copies may be obtained from the Public Information Office, Air 

Resources Board, 1001 I Street, 1st Floor, Visitors and Environmental Services Center, 

Sacramento, California 95814, (916) 322-2990. 

For individuals with sensory disabilities, this document is available in Braille, large print, 

audiocassette or computer disk. Please contact ARB's Disability Coordinator at 

(916) 323-4916 by voice or through the California Relay Services at 711, to place your 

request for disability services. If you are a person with limited English and would like to 

request interpreter services, please contact ARB's Bilingual Manager at 

(916) 323-7053. 

 

For questions, contact: 

Ms. Sylvia Zulawnick or Patricia Velasco, Ph.D. 

Manager, PM Analysis Section Project Lead 

Phone: (916) 324-7163 Phone: (916) 323-7560 

Email: szulawni@arb.ca.gov Email: pvelasco@arb.ca.gov

 P.O. Box 2815 

 Sacramento, California 95812 
PRINCIPAL AUTHOR 

Patricia Velasco, Ph.D., Project Lead 

PROJECT MANAGERS 

Sylvia Zulawnick, Manager, Particulate Matter Analysis Section 

Karen Magliano, Chief, Air Quality Data Branch 

CONTRIBUTORS 

Air Quality and Transportation Planning

Kurt Karperos, P.E., Chief, Air Quality and Transportation Planning Branch 

Ravi Ramalingam, P.E., Manager, Transportation Strategies Section 

Jeff Lindberg, Planning Liaison to the San Joaquin Valley Air Pollution Control District 

Kyriacos Kyriacou, Ph.D., Air Resources Engineer 

Air Quality Data Branch

Katazyna Turkiewicz, Air Pollution Specialist 

Eugene Kim, Ph.D., Air Resources Engineer 

Air Quality Modeling

John DaMassa, Chief, Modeling and Meteorology Branch 

Vernon Hughes, Manager, Atmospheric Modeling and Support Section 

Ajith Kaduwela, Ph.D., Manager, Regional Air Quality Modeling Section 

Kathleen Fahey, Ph.D., Air Pollution Specialist 

Cheryl Taylor, Air Resources Engineer 

Emission Inventory

Karen Buckley, Manager, Emission Inventory Systems Section 

Martin Johnson, P.E., Staff Air Pollution Specialist 
ACKNOWLEDGMENT 

ARB staff thanks the staff of the San Joaquin Valley Unified Air Pollution Control District 

for the high level of coordination between the agencies in the development of the 

technical elements of this plan. 
TABLE OF CONTENTS 

EXECUTIVE SUMMARY ................................................................................................ 1

I. BACKGROUND...................................................................................................... 1

A. Profile of the San Joaquin Valley ............................................................... 1

B. PM2.5 Health Effects and Federal Air Quality Standards......................... 3

C. Air Quality .................................................................................................... 3

D. California Regional Particulate Matter Air Quality Study (CRPAQS) ...... 6

II. AIR QUALITY PLANNING ..................................................................................... 8

A. Air Quality Planning Background .............................................................. 8

B. Recent Air Quality Planning ....................................................................... 8

C. General Planning Requirements ................................................................ 9

III. PLAN EVALUATION............................................................................................ 10

A. Overview of the San Joaquin Valley PM2.5 Plan .................................... 10

B. Emission Inventory ................................................................................... 11

1. Estimating Emissions ............................................................................... 11

2. Summary of Baseline Emissions ............................................................. 12

C. Air Quality Modeling.................................................................................. 15

1. Grid-based Photochemical Modeling....................................................... 15

2. Weight of Evidence.................................................................................... 16

3. Demonstrating Attainment........................................................................ 17

4. Attainment Date ......................................................................................... 19

D. Control Strategy ........................................................................................ 20

1. New District Measures .............................................................................. 21

a. Rule Development Commitment .................................................................. 21

b. Incentive-based Strategies........................................................................... 25

2. Adopted State Strategy............................................................................. 26

E. Reasonable Further Progress .................................................................. 28

F. Contingency Measures ............................................................................. 28

G. Reasonably Available Control Measure Analysis................................... 29

1. District RACM ............................................................................................ 29

2. Metropolitan Planning Organizations RACM .......................................... 29

H. Transportation Conformity Budgets........................................................ 30

I. Environmental Impacts ............................................................................. 31

IV. STAFF RECOMMENDATION .............................................................................. 31

APPENDIX A - Regional Air Quality Modeling 

APPENDIX B - Weight of Evidence 
 

ES-1 

EXECUTIVE SUMMARY 

On April 30, 2008, the San Joaquin Valley Air Pollution Control District (District) adopted 

a PM2.5 Attainment Plan showing how the region will comply with the federal PM2.5 air 

quality standards set by the U.S. Environmental Protection Agency (U.S. EPA) in 1997. 

The staff of the Air Resources Board (ARB or Board) has reviewed the Plan and 

recommends that the Board approve it as a State Implementation Plan (SIP) revision to 

be submitted to U.S. EPA. The Plan shows that the region now meets the daily 

(24-hour) standard, and demonstrates how the more challenging annual standard will 

be met by 2014. The Plan documents that emissions of PM2.5 particles, and the 

pollutants that form PM2.5, are decreasing each year. A mid-course review of plan 

implementation will be done in 2011 as required by U.S. EPA 

The Plan consists of adopted measures that provide increasing benefits each year, 

along with new emission reduction commitments from both ARB and the District. The 

Valley’s particle pollution problem is well studied as a result of the $27 million invested 

in the California Regional Particulate Matter Study. This study provides the scientific 

foundation for the PM2.5 SIP by identifying the pollutants most important to formation of 

PM2.5 pollution. The results indicate that the key pollutants to reduce are NOx, SOx, 

and directly emitted PM2.5 particles. The Plan addresses these three pollutants 

consistent with U.S. EPA guidance. Emissions of VOC are also being reduced in the 

region as part of the ozone attainment strategy but are not required to be included in 

this SIP. 

Overall, between 2005 and 2014, NOx emissions will decrease by almost 300 tons per 

day (tpd), direct PM2.5 emissions by over 20 tpd, and SOx by almost 3 tpd. Two thirds 

of the NOx and SOx reductions and one half of the PM2.5 reductions come from 

already adopted measures. A significant portion of the new commitments come from 

the ARB’s State Strategy that was adopted in September 2007. The State Strategy 

provides an additional 76 tons of NOx reductions and 5 tons of PM2.5 reductions in 

2014. The District has accelerated several measures in its 2007 Ozone Plan that are 

also part of the PM2.5 attainment strategy, and targeted a number of categories of 

PM2.5 for additional emission reductions, including residential wood burning and 

commercial cooking. Past District efforts to reduce impacts from residential wood 

burning have proven to be very effective, and continued reductions in this source 

category are expected to contribute significantly to further progress. 

As emissions have decreased each year, parts of the Valley are already meeting the 

annual standard. The air quality modeling indicates that attaining the annual standard 

in the southern Valley is the biggest challenge, but all areas are projected to attain the 

standard by 2014. The Plan will also bring the region much closer to meeting a new 

federal PM2.5 standard that will apply to future SIP planning efforts. SIP planning for 

the newer standard will occur after U.S. EPA designates nonattainment areas and 

develops implementation rules. 
 

ES-2 

The Plan demonstrates the rate of emission reductions that will occur between now and 

the attainment year. As shown below 307 tons per day of reductions are needed 

between 2005 and 2014. The Plan outlines how these reductions will be achieved. 

While the majority of the reductions are NOx, it is important to recognize that the PM2.5 

reductions are also essential because air quality modeling shows each ton of direct 

PM2.5 is approximately nine times more effective ton per ton in the attainment year. 

Staff’s review indicates that the Plan meets the requirements of the Clean Air Act (Act) 

and U.S. EPA’s PM2.5 implementation rule. The SJV 2008 PM2.5 Plan demonstrates 

attainment as expeditiously as practicable, no later than 2014, as required by the Act. 

The Plan also includes reasonable further progress calculations, reasonably available 

control measures and technologies, contingency measures, emission inventories, 

transportation conformity budgets, and a commitment for a SIP update in 2011. 

Additional reductions from adopted ARB measures will provide NOx reductions for 

contingency purposes should the region not attain in 2014. 

The PM2.5 Plan is the result of a two year effort to update the emission inventories for 

each mobile, stationary, and area source category, conduct air quality modeling and 

data analysis, and to develop new control strategies. The 2011 SIP update will provide 

an important opportunity to assess air quality progress, update emission inventories, 

and check on the progress in achieving emission reductions. 

Recommendations: Staff recommends that the Board approve the District’s 2008 

PM2.5 attainment Plan. 

Countdown to Attainment Levels

0

50

100

150

200

250

300

350

2005 2009 2012 2014

Emission Reduction Needed (tpd)

NOx PM2.5

All SIP reductions 

achieved 
 

1 

I. BACKGROUND 

A. Profile of the San Joaquin Valley 

Covering nearly 25,000 square miles, the San Joaquin Valley is one of the dominant 

features in California’s landscape. One of the fastest growing regions in the State, the 

Valley is home to more than 3.6 million people. The Valley has four large cities, 

Stockton, Modesto, Fresno, and Bakersfield, each with a population greater than 

200,000. Numerous smaller cities and towns in the Valley are separated by large 

expanses of agricultural lands. With urbanization, agricultural lands continue to be 

converted to non-agricultural uses. 

The San Joaquin Valley Air Basin is a lowland area bordered by the Sierra Nevada 

Mountains to the east, the Pacific Coast range to the west, and the Tehachapi 

Mountains to the south. The mountains act as air flow barriers, with the resulting 

stagnant conditions favoring the accumulation of emissions and pollutants. As a result, 

PM2.5 concentrations are higher in the southern and central portions of the Valley, 

where geography, emissions, and climate pose significant challenges to air quality 

progress. 

PM2.5 is a complex mixture of many different species generated from a wide array of 

sources. PM2.5 can be either emitted directly into the air (primary particles) in forms 

such as soot, smoke, and the tiniest specs of dust, or it can be formed in the 

atmosphere (secondary particles or aerosol droplets) from the reactions of precursor 

gases, nitrogen oxides (NOx), sulfur oxides (SOx), reactive organic gases (ROG), and 

ammonia. NOx and ROG are also precursors of ozone pollution. Understanding the 

nature of the PM2.5 problem is key to designing an effective control strategy. 

In the Valley, the levels and nature of PM2.5 concentrations typically differ by season 

(Figure 1). Higher PM2.5 concentrations occur during the winter, between late 

November and February during extended periods of stagnant weather with cold, damp, 

foggy conditions, which are conducive to the formation of secondary ammonium nitrate 

particulates. At these times, PM2.5 is dominated by ammonium nitrate formed from 

NOx and ammonia emissions, and directly emitted particles, such as wood smoke and 

other combustion sources. 
 

2 

Figure 1. Seasonal Variation in PM2.5 Concentrations in the San Joaquin Valley. 

The elevated winter PM2.5 concentrations drive the annual average PM2.5 levels. On 

an annual basis, PM2.5 in the Valley consists mostly of ammonium nitrate, organic 

carbon, and ammonium sulfate (Figure 2). Ammonium nitrate is formed from chemical 

reactions of NOx emitted from motor vehicles and stationary combustion sources with 

ammonia. Burning activities, such as residential wood combustion, cooking, and direct 

tailpipe emissions from mobile sources are major sources of organic carbon. 

Ammonium sulfate is also formed in the atmosphere from chemical reactions of SOx 

emitted from combustion sources and ammonia. To a lesser extent, elemental carbon 

resulting from mobile and stationary combustion sources, and geological material from 

roads and other dust producing activities also contribute to PM2.5. 

Figure 2. PM2.5 Composition in the San Joaquin Valley 

Seasonal Variation in PM2.5 

San Joaquin Valley (2006)

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12

Month

Concentrations (ug/m3)

Fresno-1st Bakersfield-California

2004-2006 Average Composition

Bakersfield

Geological

6%

Ammonium 

Sulfate

13%

Organic 

Carbon

35%

Ammonium 

Nitrate

39%

Elemental 

Carbon

5%

Elements

2%

2004-2006 Average Composition

Fresno

Geological

4%

Organic 

Carbon

41%

Ammonium 

Sulfate

11%

Ammonium 

Nitrate

37%

Elemental 

Carbon

5%

Elements

2%
 

3 

B. PM2.5 Health Effects and Federal Air Quality Standards 

Extensive research over the last two decades has investigated the effects that breathing 

PM2.5 has on people’s health. Research studies have consistently found a link 

between PM2.5 exposure and premature death in people with existing cardiac or 

respiratory disease. Studies of large populations have found that exposure to PM2.5 is 

associated with increased hospital admissions and emergency room visits due to 

frequent and severe asthma attacks, pneumonia, and acute and chronic bronchitis, 

primarily in people with chronic heart or lung diseases. Long-term exposure to PM2.5 

has also been linked to an increase in lung cancer mortality risk. Those most at risk of 

experiencing adverse effects with PM2.5 exposure include infants, children, the elderly, 

and persons with pre-existing cardiopulmonary disease. 

U.S. Environmental Protection Agency (U.S. EPA) adopted national ambient air quality 

standards (NAAQS) for PM2.5 in 1997, with a 24-hour PM2.5 standard of 

65 micrograms per cubic meter (μg/m3

) and an annual standard of 15 μg/m3. State 

Implementation Plans (SIPs) for areas designated nonattainment for these standards 

are due to U.S. EPA in 2008. The San Joaquin Valley is currently designated as 

nonattainment for the 1997 PM2.5 standards and the 2008 SJV PM2.5 Plan addresses 

these standards. In 2006, U.S. EPA adopted a new 24-hour PM2.5 standard that will 

apply to future SIP planning efforts. SIP planning for the newer standard will occur after 

U.S. EPA designates nonattainment areas and develops implementation rules

C. Air Quality 

While the San Joaquin Valley has one of the most severe PM2.5 problems in the nation, 

PM2.5 air quality has shown considerable improvement. Initial efforts to monitor PM2.5 

began in 1990. Annual average PM2.5 concentrations decreased between 20 to 

30 percent during the period of 1990 through 2001. Due to the marked and complex 

variability in the Valley’s meteorological conditions, some years are far more conducive 

to PM2.5 formation and accumulation than others. However, overall concentrations 

show a downward long-term trend (Figure 3). 
 

4 

Figure 3. Long-term Trends in PM2.5 Concentrations in the San Joaquin Valley 

Since 1999, when monitoring for compliance with the federal PM2.5 standards began, 

PM2.5 annual average concentrations have dropped a further 19 to 29 percent. When 

the San Joaquin Valley was first designated nonattainment for the federal PM2.5 

standards, the basin exceeded both the annual and the 24-hour PM2.5 standards. 

However, based on 2004-2006 data, the San Joaquin Valley now meets the federal 

24-hour PM2.5 standard of 65 ug/m3. Thus, this SIP focuses on what more is needed 

to attain the annual standard. 

For planning purposes, U.S. EPA recommends using the average of the mean annual 

PM2.5 concentrations measured over a three year period. This is referred to as the 

“design value” and reduces the year to year variability. Table 1 provides the 2006 

annual standard design values and the annual average values for 2004, 2005, and 2006 

for each monitoring site with complete data. The northern portion of the Valley meets 

the annual PM2.5 standard, as indicated by the design values at Stockton, Modesto, 

and Merced. The highest PM2.5 annual design values are located in the southern and 

central portions of the basin, including Bakersfield and Visalia. 

Three-Year Average PM2.5 Trend

0

5

10

15

20

25

30

35

199019911992199319941995199619971998199920002001

Concentrations (ug/m3)

Bakersfield

Fresno-1st Street

Stockton

Visalia
 

5 

Table 1. PM2.5 Annual Average Concentrations and 2006 Design Values 

 Annual Average 

(ug/m3

) 

Monitor 2004 2005 2006 

2006 

3-year Annual Average 

Design Value (ug/m3

) 

Clovis-N Villa Avenue 15.8 16.0 16.8 16.2 

Bakersfield-410 E Planz Road 17.4 19.9 19.3 18.9 

Bakersfield-5558 California Avenue 19.0 17.9 18.7 18.5 

Bakersfield-Golden State Highway 18.1 18.9 18.6 18.5 

Corcoran-Patterson Avenue 17.3 17.6 16.7 17.2 

Fresno-1st Street 16.4 16.9 16.8 16.7 

Fresno-Hamilton and Winery 17.0 16.9 17.6 17.2 

Merced-2334 M Street 15.3 14.1 14.8 14.7 

Modesto-14th Street 13.6 13.9 14.8 14.1 

Stockton-Hazelton Street 13.2 12.5 13.1 12.9 

Visalia-N Church Street 17.0 18.8 18.8 18.2 

Trends in annual PM2.5 design values show that considerable progress has occurred in 

the San Joaquin Valley over the last five years (Figure 4). In 2001, all monitoring sites 

in the Valley had annual design values greater than 16 ug/m3, with the Visalia site at 

approximately one and a half times the level of the standard. By 2006, design values 

decreased throughout the Valley, and only those sites in the southern and central 

portions of the Valley still have design values greater than 16 ug/m3

. Bakersfield–Planz 

is the current high site, with a design value which is 26 percent above the standard. 

The greatest rate of progress has occurred in the northern and central basin. These 

trends underscore the challenge the Valley faces in attaining the annual standard in the 

southern portions of the Valley. The surrounding mountains combined with the Valley’s 

prevalent cold, damp, stagnant winters, create an environment very conducive to PM2.5 

formation and buildup, especially in the southern end of the Valley. 

Figure 4. Trends in Annual PM2.5 Design Values in the San Joaquin Valley 

Three-Year Annual Average PM2.5 Design Values

0

5

10

15

20

25

30

2001 2002 2003 2004 2005 2006

Year

Concentrations (ug/m3)

Bakersfield-410 E Planz

Bakersfield-5558 California

Bakersfield-Golden

Modesto-14th Street

Stockton-Hazelton

Visalia-N Church

Fresno-1st Street
 

6 

In addition to looking at trends in average concentrations of PM2.5, it is also useful to 

look at the trends of the different components that make up PM2.5. As stated earlier, 

PM2.5 is a complex mixture dominated by ammonium nitrate, organic carbon, and 

ammonium sulfate. Analysis of the trends in the different components of PM2.5 shows 

that over the last five years, decreases in carbonaceous aerosols and ammonium 

nitrate have had the greatest impact on declining PM2.5 levels. In Fresno, 

carbonaceous aerosols have declined by 37 percent and ammonium nitrate 

concentrations by 24 percent (Figure 5), while in Bakersfield, carbonaceous aerosols 

(organic plus elemental carbon) have declined by 16 percent and ammonium nitrate 

concentrations by 23 percent. During this same period, PM2.5 and NOx emissions, as 

well as NOx levels measured in the air also decreased. Longer-term records show 

concomitant decreases between ambient NOx and ammonium nitrate as well as 

between ambient SOx and ammonium sulfate. The combined downward trends in 

PM2.5 components, precursor concentrations, and emissions all indicate that the 

ongoing control program has had substantial benefits in improving air quality and that 

the reductions from measures in this Plan will provide continuing progress towards and 

attainment of the federal PM2.5 standards. 

Figure 5. Trends in PM2.5 Key Chemical Components. 

D. California Regional Particulate Matter Air Quality Study (CRPAQS)1

The California Regional Particulate Air Quality Study (CRPAQS) provides the scientific 

foundation upon which the PM2.5 SIP planning efforts are built. CRPAQS is a 

collaborative effort between the public and private sector designed to: 1) develop an 

improved understanding of particulate matter in central California; and, 2) provide 

 

1 http://www.arb.ca.gov/airways/ccaqs.htm

Trends in PM2.5 Chemical Components 

Fresno-1st

0

2

4

6

8

10

12

14

2001* 2002* 2003 2004 2005 2006

Concentrations (ug/m3)

Ammonium

Nitrate

Ammonium

Sulfate

Carbonaceous

Aerosols
 

7 

decision-makers with the tools needed to identify equitable and efficient control 

methods. The study is a comprehensive multi-year effort of meteorological and air 

quality monitoring, emission inventory development, data analysis, and air quality 

simulation modeling. The study reflects an investment of nearly 27 million dollars, 

coupled with extensive in-kind support from study sponsors, extending over a 15-year 

period. The resulting data and analytical tools are providing the most advanced 

scientific understanding available for SIP development. 

CRPAQS is intended to evaluate the Valley’s particulate matter challenges with respect 

to both the federal and State air quality standards for particulate matter smaller 

than 10 micrometers in diameter (PM10) and PM2.5. CRPAQS was designed to 

address annual particulate levels as well as fall and winter episodic conditions. 

Numerous teams of experts participated in the study. Data was collected for 14 months 

(December 1999 through February 2001) throughout the Valley and surrounding 

regions. The extensive field monitoring program collected data at the surface from 

hundreds of monitoring sites located throughout the study domain, and aloft with 

appropriately equipped air planes, blimp, specialized balloons, and towers (Figure 6). 

The effort resulted in millions of data records which have been housed in a world class 

data base. Focused efforts have also improved the emission inventory for the region. 

Finally, state-of–the-science air quality models have been tested with the extensive 

CRPAQS data base and are used in the CRPAQS and SIP modeling tasks. 

Figure 6. CRAPQS Monitoring Program 
 

8 

II. AIR QUALITY PLANNING 

A. Air Quality Planning Background 

The federal Clean Air Act Amendments of 1990 (Act) establish the planning 

requirements for those areas that routinely exceed the health-based NAAQS. These 

nonattainment areas must adopt and implement a State Implementation Plan (SIP) that 

demonstrates how they will attain the standards by specified dates. Federal law holds 

each state responsible for implementing the provisions of the Act. California law 

assigns air quality planning responsibilities within the State. In the San Joaquin Valley, 

those responsibilities are shared among the San Joaquin Valley Air Pollution Control 

District (District), the Valley’s metropolitan planning organizations, and the 

Air Resources Board (ARB). 

In the air quality management process, many regulatory agencies in California work 

together to reduce air pollution levels. Each of these agencies is responsible for 

achieving emission reductions from a part of the inventory. ARB has primary regulatory 

authority over California’s mobile sources, fuels, and consumer products. U.S. EPA 

sets new engine standards for sources including large farm and construction equipment 

and locomotives. Air districts have primary authority over stationary emission sources, 

including industrial and commercial equipment and area sources. The metropolitan 

planning organizations are responsible for developing the regional transportation plans 

that are used to estimate mobile source emissions. These transportation plans can also 

impact land use patterns, and the availability and attractiveness of transit alternatives. 

The air districts develop and adopt local air quality plans. In this case, the District 

approved the SJV 2008 PM2.5 Plan on April 30, 2008. Upon approval by the ARB, 

SIPs are submitted to U.S.EPA for approval. Once approved by U.S. EPA, SIPs 

become enforceable. 

B. Recent Air Quality Planning 

Over the past decade, the District and ARB have adopted a series of regulations and 

measures to improve air quality in the Valley. New mobile source requirements, cleaner 

fuels, and multiple consumer products regulations have been adopted and are being 

implemented today. And, while California continues to face serious air quality 

challenges, it is important to recognize the progress made as a result of California’s 

landmark air pollution control programs. 

The District has implemented a successful PM10 attainment plan which has resulted in 

the Valley coming into attainment of the federal PM10 standard. U.S. EPA concurred 

with the District’s attainment assessment, and on March 19, 2008, published a final 

affirmation of attainment of the PM10 standard for the Valley2

. In addition, on 

 

2

 Federal Register: March 19, 2008 (Volume 73, Number 54, pages 14687-14713) 
 

9 

April 25, 20083, U.S. EPA proposed approval of the District’s plan to maintain the PM10 

standard. 

On April 2007, the District adopted the 2007 Ozone Plan. The ozone plan charts the 

course to attainment of the federal 8-hour ozone NAAQS in the Valley. ARB approved 

the ozone plan and submitted it to U.S. EPA as a SIP revision. Many of the measures 

in the PM10 and ozone plans are providing progress towards attainment of the PM2.5 

standards. 

On September 27, 2007, ARB adopted the 2007 State Strategy to achieve new 

emission reductions needed to bring areas of the State into attainment of both the 

federal PM2.5 and ozone air quality standards. The commitment for 2014 in the State 

Strategy includes reductions needed to attain the PM2.5 standards and provide 

progress towards meeting the ozone standard. 

C. General Planning Requirements 

On April 25, 2007, U.S. EPA finalized it’s implementation rule for PM2.54

. The rule 

outlines the planning elements that the PM2.5 SIP must address. These include: 

• base year and future year emission inventories for manmade sources of air 

pollution in the nonattainment area; 

• air quality modeling that demonstrates attainment of the PM2.5 standards as 

expeditiously as practicable; 

• weight of evidence - supplemental analysis of air quality, emission data, and 

trends supporting the primary modeled attainment demonstration; 

• control strategies capable of meeting attainment; 

• reasonable further progress (RFP) plan; 

• contingency measures in the event the controls fall short of achieving needed 

reductions; 

• demonstration that all reasonably available control technology (RACT) and 

reasonably available control measures (RACM) have been applied to existing 

sources; 

• transportation conformity emission budgets to ensure transportation plans and 

projects are consistent with the SIP; and 

• commitment for mid-course review. 

 

3

 Federal Register: April 25, 2008 (Volume 73, Number 81, pages 22307-22318 4

 Federal Register: April 25, 2007 (Volume 72, Number 79, pages 20586-20587) 
 

10 

III. PLAN EVALUATION 

A. Overview of the San Joaquin Valley PM2.5 Plan 

The SJV 2008 PM2.5 Plan provides the technical foundation and control strategy for 

attaining the federal PM2.5 standards. The Plan demonstrates the Valley will attain the 

standards as expeditiously as practicable, no later than the 2014 deadline. 

The Plan consists of adopted measures that provide increasing benefits each year, 

along with new emission reduction commitments from both ARB and the District. The 

Valley’s particle pollution problem is well studied as a result of the $27 million invested 

in the California Regional Particulate Matter Study. This study provides the scientific 

foundation for the PM2.5 SIP by identifying the pollutants most important to formation of 

PM2.5 pollution. The results indicate that the key pollutants to reduce are NOx, SOx, 

and directly emitted PM2.5 particles. The Plan addresses these three pollutants 

consistent with U.S. EPA guidance. Emissions of VOC are also being reduced in the 

region as part of the ozone attainment strategy but are not required to be included in 

this SIP. 

Overall, between 2005 and 2014, NOx emissions will decrease by almost 300 tons per 

day (tpd), direct PM2.5 emissions by over 20 tpd, and SOx by almost 3 tpd. Two thirds 

of the NOx and SOx reductions and one half of the PM2.5 reductions come from 

already adopted measures. A significant portion of the new commitments come from 

the ARB’s State Strategy that was adopted in September 2007. The State Strategy 

provides an additional 76 tons of NOx reductions and 5 tons of PM2.5 reductions in 

2014. The District has accelerated several measures in its 2007 Ozone Plan that are 

also part of the PM2.5 attainment strategy, and targeted a number of categories of 

PM2.5 for additional emission reductions, including residential wood burning and 

commercial cooking. Past District efforts to reduce impacts from residential wood 

burning have proven to be very effective, and continued reductions in this source 

category are expected to contribute significantly to further progress. 

As emissions have decreased each year, the entire Valley already meets the daily 

standard and parts of the Valley are already attaining the annual standard. The air 

quality modeling indicates that attaining the annual standard in the southern Valley is 

the biggest challenge, but all areas are projected to attain the standard by 2014. The 

Plan will also bring the region much closer to meeting a new federal PM2.5 standard 

that will apply to future SIP planning efforts. SIP planning for the newer standard will 

occur after U.S. EPA designates nonattainment areas and develops implementation 

rules. 

ARB staff has reviewed the 2008 PM2.5 Plan and the District’s technical analysis and 

agrees that the Plan meets federal requirements. The following sections describe the 

major elements of the Plan. 
 

11 

B. Emission Inventory 

An emission inventory consists of a systematic list of the sources of air pollutants with 

an estimate of amount of pollutants from each source or source category over a given 

period of time. The inventories used in this Plan were developed using the most recent 

planning assumptions and the best available technical information. 

Air quality plans rely on emission inventories to help identify sources to control and as 

inputs to the photochemical models required for attainment demonstrations. Planning 

inventories which are aggregated by source type and inventory sector focus on 

anthropogenic sources and are expressed as annual average day and average 

seasonal day. In the case of PM2.5, ambient concentrations are highest in the winter 

so the planning inventory includes an estimate of average winter day emissions. This 

helps planners identify what source categories have the highest emissions during those 

periods when the PM2.5 ambient values are highest. Modeling inventories include both 

emissions from human activities (anthropogenic sources) and from natural sources 

(non-anthropogenic sources). Emissions are both spatially distributed geographically 

and represent hourly estimates for each grid cell in the modeling domain. The emission 

estimates also include the effects of climatic factors such as temperature and humidity. 

The models relate current air quality to current emissions levels of PM2.5 and its 

precursors, and simulate future air quality based on changes to the emissions as the 

result of new control measures. The current or baseline inventories used in the Plan 

reflect District and ARB controls adopted through 2006 and assume an estimated 24 

percent growth in population and 14 percent growth in vehicle miles traveled in the 

estimated future year inventories. Baseline inventories do not include potential 

reductions from the new District measures identified in the SJV 2008 PM2.5 Plan or 

ARB measures in the adopted 2007 State Strategy. 

1. Estimating Emissions 

In California, computer models developed by ARB are used to estimate the emissions 

from on- and off-road mobile sources. Stationary source emissions estimates are 

developed by the Districts and derived from permit data. Area-wide emissions are 

estimated based on emission factors and information on expected activity from these 

diverse sources. Area-wide and off-road source emissions are estimated by ARB and 

the District. Emission inventories undergo routine reevaluation to ensure that they 

remain up to date and accurate. 

Emission estimates used in the SJV PM2.5 2008 Plan take into account emission data, 

expected growth in activity, and ARB regulations and District rules adopted by 

December 2006. Mobile source emission inventories used in the Plan were developed 

using EMFAC2007, California's on-road motor vehicle emission factor model and 

OFFROAD2007 for emissions from mobile off-road vehicles and equipment. 

Transportation activity data was provided by the eight Valley Councils of Government 

(COGs) from their Regional Transportation Plans. 
 

12 

The District worked with ARB staff to update emission estimates from stationary and 

area source categories for which new and improved data became available. 

Improvements targeted the day-specific modeling inventory as well as the annual and 

winter planning inventories. Annual and winter planning inventory adjustments included 

District methodology revisions and impacts of adopted rules (e.g., open burning, wood 

burning fireplaces and heaters, cooking, manufacturing and industrial fuel combustion). 

A summary of a major District revision, as well as ARB updates follows: 

 Non-point source manufacturing and industrial natural gas combustion. 

District staff refined the methodology for estimating emissions from industrial natural 

gas combustion sources that are too small to fall into the District’s permitting 

program. Using data from the California Energy Commission on natural gas 

deliveries, District staff estimates 2005 NOx emissions are 25 tpd less that 

previously estimated and in 2014 they are 29 tpd less. 

 PM2.5 size fractions for fugitive dust sources. 

ARB staff updated the estimates of dust in the PM2.5 size fraction based on PM size 

fraction profiles developed by the Western Regional Air Partnership (WRAP)5,6 and 

PM2.5/PM10 ratios obtained from air quality measurements in California. Previously 

used profiles for dust emitting categories (e.g., paved and unpaved roads, 

construction and demolition, agricultural tilling) overestimated the amount of dust in 

the PM2.5 size fraction. 

 Paved Road Dust

ARB staff refined PM2.5 emission estimates from paved road dust by subtracting 

PM2.5 emissions from vehicle exhaust, tire wear, and brake wear to avoid double 

counting. These emissions are already accounted for in the on-road motor vehicle 

emission inventory. In addition, ARB staff revised the rate at which emissions are 

grown from the base year to a future year to reflect projected lane miles of new road. 

2. Summary of Baseline Emissions 

Emission sources in the San Joaquin Valley are diverse. The San Joaquin Valley is an 

important transportation corridor for moving goods and people inside the State and 

beyond. In addition, it is one of the most productive agricultural regions in the world, as 

well as home to industrial and commercial activities. All of these sources contribute to 

the concentrations of pollutants in the Valley. 

The following discussion focuses on the annual planning inventory used in the 

SJV 2008 PM2.5 Plan. Appendix B of the SJV 2008 PM2.5 Plan includes detailed 

 

5

 Cowherd, C. Analysis of the Fine Fraction of Particulate Matter in Fugitive Dust, Final Report. 

October 12, 2005. Midwest Research Institute. MRI Project No. 110397. 

phttp://www.wrapair.org/forums/dejf/documents/fffd/Final_Fractions_Dust_Report.pdf 6

 Cowherd, C., Proposed Revisions to Fine Fraction Ratios Used for AP-42 Fugitive Dust Emission 

Factors. November 7, 2005. Midwest Research Institute. MRI Project No. 110397 
 

13 

annual average and winter average daily planning inventories for directly emitted 

PM2.5, and the precursors NOx and SOx for 2005 and for each year from 2009 to 2014. 

Table 2 lists the baseline annual planning inventory for 2005 and 2014 for directly 

emitted PM2.5, NOx, and SOx precursors in the San Joaquin Valley in 2005 and 

emissions projected for the 2014 attainment year split by source category. 
 

14 

Table 2. San Joaquin Valley Air Basin 

Baseline Emission Trendsa,b 

(Annual Planning Inventory in tons per day, tpd) 

Source Category

Pollutant Emissions Stationary 

and AreaWide

On-Road 

Vehicles

Off-Road 

Vehicles 

and 

Equipment

Totalb 

2005 

(tpd) 64.9 12.1 9.0 86.0 

2014 

(tpd) 59.5 8.9 6.6 75.0 

Change 

(tpd) -5.4 -3.2 -2.4 -11.0 

PM2.5 

Change 

(%) -8% -26% -27% -13% 

2005 

(tpd) 93.6 327.9 153.9 575.4 

2014 

(tpd) 67.3 206.7 102.2 376.2 

Change 

(tpd) -26.3 -121.2 -51.7 -199.2 

NOx 

Change 

(%) -28% -37% -34% -35% 

2005 

(tpd) 21.3 2.6 2.4 26.4 

2014 

(tpd) 22.9 0.7 0.8 24.5 

Change 

(tpd) +1.6 -1.9 -1.6 -1.9 

SOx 

Change 

(%) +7% -73% -67% -7% 

a. Baseline emissions include State control measures and District controls adopted through 2006. 

b. Numbers may not add up exactly due to rounding. 
 

15 

In summary, baseline PM2.5, NOx, and SOx emissions from all sources in the Valley 

show an overall downward trend due to already adopted regulations and programs. 

The slight increase in SOx from stationary sources is addressed in the Plan. Although 

motor vehicle miles traveled in the basin continue to increase, on-road vehicle 

emissions are dropping because of more stringent vehicle emission standards and fleet 

turnover. This trend will be strengthened between 2005 and 2014 as newer, loweremitting vehicles become part of the fleet. 

C. Air Quality Modeling 

Air quality modeling guides the selection of the most effective pollutants to control and 

the magnitude of emission reductions needed from each of the pollutants. U.S. EPA’s 

modeling guidance requires the use of air quality modeling to relate current PM2.5 

levels to emissions (of PM2.5 and PM2.5 precursors) and meteorology in a region, and 

to simulate future air quality based on changes in emissions. PM2.5 air quality 

modeling uses day-specific grid-based emission inventories and meteorological 

measurements to establish this relationship. Model predictions combined with observed 

concentrations of PM2.5 and its individual components provide the foundation for the 

U.S. EPA-recommended attainment demonstration (Speciated Modeled Attainment 

Test). Rather than using air quality model predicted PM2.5 concentrations results 

directly, U.S. EPA Guidance calls for using models in a relative sense to develop 

relative response factors (RRFs) for each of the PM2.5 chemical species. The RRFs 

are calculated as the ratios of the future-year to reference-year model-simulated 

concentrations of PM2.5 species at a specific location. The impact that emission 

reductions have on the future-year modeled PM2.5 species is assumed to be 

proportional to the impact on the base-year PM2.5 design value. The attainment test 

provides reconciliation between speciated and bulk mass concentration measurements, 

and is the basis for a connection between observations, modeled PM2.5 concentrations, 

and the air quality standard. 

ARB staff conducted the grid-based photochemical modeling used in the 

SJV 2008 PM2.5 Plan with input from the District. The modeling analysis is based on 

data acquired from the $27 million state-of-the-science CPRAQS study. Modeling 

procedures followed U.S. EPA guidelines. A brief summary is provided below with more 

information on the air quality modeling conducted by ARB staff in Appendix A to this 

report and Appendix F of the SJV 2008 PM2.5 Plan. 

1. Grid-based Photochemical Modeling 

Grid-based photochemical modeling supports attainment demonstrations of the annual 

and the 24-hour PM2.5 standards in the San Joaquin Valley. The modeling platforms 

and chemical mechanism used in the photochemical modeling are summarized below. 

U.S. EPA’s Community Multiscale Air Quality Modeling System (CMAQ) was selected to 

simulate air quality in the San Joaquin Valley. CMAQ is a state-of-the-science “oneatmosphere” system that treats major atmospheric and land processes and a range of 
 

16 

species in a comprehensive framework. CMAQ has been extensively peer-reviewed 

and is well documented. A meteorological model, the Mesoscale Model version 5 

(MM5), was used to generate the meteorological fields for the CMAQ model. Modelers 

chose the most up-to-date and comprehensive chemical mechanism (SAPRC99) along 

with CMAQ aerosol code version 4 and aqueous phase chemistry to simulate the 

complex mixture of PM2.5 species in the San Joaquin Valley. 

CMAQ was run for the year 2000 to provide the basis for the model performance 

evaluation. It was during 2000 that the CRPAQS took place. The study resulted in a 

wealth of data with which to evaluate model performance. As it is necessary to execute 

simulations for a model reference year and a future year to perform the recommended 

modeled attainment demonstration, 2005 and 2014 were also simulated. Simulations 

for all years were driven by the meteorological inputs for 2000, while emissions varied 

from year to year. Meteorological conditions during 2000 were very conducive to the 

formation and accumulation of PM2.5. 

As recommended by U.S. EPA, the SMAT procedure was applied to Federal Reference 

Monitors (FRM) operating in the San Joaquin Valley. The 2006 design value (average 

of the 2004, 2005, and 2006 annual average PM2.5 concentrations) was used as a 

basis from which to project estimated future year design values for the year 2014 

(average of the 2012, 2013, 2014 annual average PM2.5 concentrations). Speciation of 

the FRM mass was based on data from the Speciated Trends Network (STN) sites in 

the Valley and on analysis of CRPAQS data. 

The attainment demonstration for the annual standard required modeling PM2.5 

concentrations for each day of the reference year (2005) and future year (2014). The 

attainment demonstration for the 24-hour PM2.5 standard used only the top 25% of the 

measured and modeled days for each quarter instead of all available days. 

ARB staff evaluated air quality model and meteorological model performance based on 

U.S. EPA guidance and other related methods in the published academic literature. As 

noted above, model performance evaluation benefited from use of the extensive 

CRPAQS data set, ensuring a robust modeling simulation. 

2. Weight of Evidence 

The Weight of Evidence (WOE) analysis provides a set of complementary analyses that 

supplement the SIP-required photochemical modeling. A WOE approach looks at the 

entirety of the information at hand to provide a more informed basis for the attainment 

strategy. Because all methods have inherent strengths and weaknesses, examining an 

air quality problem in a variety of ways offsets the limitations and uncertainty that are 

inherent in photochemical modeling. This approach also provides a better 

understanding of the overall problem and the level and mix of emissions controls 

needed for attainment. 
 

17 

Appendix H of the SJV 2008 PM2.5 Plan includes the initial draft of the WOE analysis. 

Appendix B of this staff report updates this analysis and summarizes the analyses that 

comprise the WOE assessment for the San Joaquin Valley. ARB staff evaluated air 

quality and emission trends; observational model results, including those of source 

receptor models, such as chemical mass balance (CMB) and positive matrix 

factorization (PMF); and evaluated diagnostic indicator species results. Along with the 

results from the photochemical modeling, District staff conducted a rollback modeling 

analysis to estimate the impacts of future emission reductions on resulting air quality. 

Rollback modeling combines source receptor model results with predicted emission 

inventory data that include emission reductions from adopted and proposed control 

measures to estimate future PM2.5 concentrations. Source receptor models use data 

on the concentrations of chemical species measured in ambient PM2.5 to identify the 

contributing sources. An extensive discussion of the rollback methodology and the 

results are provided in Chapter 3 of the SJV 2008 PM2.5 Plan. 

3. Demonstrating Attainment 

Modeling was used to establish emission reduction targets for developing the control 

strategy in the Plan. ARB staff used photochemical modeling to verify that the proposed 

control strategy would result in attainment of the PM2.5 standards throughout the basin 

in 2014. The emission reductions needed from new control measures to reach 

attainment throughout the Valley in 2014 are summarized in Table 3: 

Table 3. Emissions and Emission Reductionsa 

(annual average emissions in tpd) 

Direct PM2.5 NOx SOx 

2014 Baseline Emissions 75.0 376.2 25.6 

2014 Control Measure Emission 

Reduction Commitments 12.7 85.0 0.9 

2014 Attainment Emissions 63.3 291.2 24.5 

a. Numbers may not add up exactly due to rounding. 

As mentioned earlier, based on 2004-2006 data, the Valley already meets the federal 

24-hour standard. Modeling results for the five sites with highest 2006 design values 

show that further emission controls will result in even lower 24-hour design values in 

2014 (Table 4), ensuring continued progress towards the strengthened 24-hour 

standard which will be addressed in future planning efforts. 
 

18 

Table 4. Reference and Future Year 24-hour Design Values (DV)a 

(micrograms per cubic meter, μg/m3) 

Site 2006 DV 2014 "Controlled" DV 

Bakersfield - California 62.4 46.2 

Bakersfield - Planz 65.2 45.9 

Bakersfield - Golden 64.4 45.3 

Fresno - 1st Street 58.0 41.2 

Fresno - Hamilton 58.5 41.7 

a. Design values equal to or below 65.4 μg/m3

 meet the annual PM2.5 NAAQS. 

Modeled design values demonstrate the San Joaquin Valley will attain the annual 

PM2.5 federal standard in 2014 at all monitoring sites (Table 5). The 2014 design value 

is the three-year average of modeled 2012, 2013, and 2014 values. For comparison, 

Table 5 also lists the 2006 design values calculated from measured PM2.5 

concentrations and the impact of baseline emission reductions on modeled 2014 design 

values. Baseline emission reductions due to already adopted rules provide from 58 to 

63 percent of progress towards attainment. Sites in the northern and central Valley 

would be expected to attain the standard in 2014 with baseline emission reductions. 

With the addition of the new State and local measures, the sites with the most severe 

problem – Visalia and Bakersfield – would also attain in 2014, with a maximum design 

value of 14.7 in Bakersfield. The linear rollback analyses showed similar results, 

providing a consistent assessment of attainment prospects. Modeling analyses also 

show that annual PM2.5 concentrations are more sensitive to reductions in directly 

emitted PM2.5 as compared to NOx in 2014. On average, reducing 1 tpd in PM2.5 

emitted from combustion activities is approximately 9 times more effective than reducing 

1 tpd of NOx. 
 

19 

Table 5. Reference and Future Year Annual Design Valuesa

(μg/m3) 

Site 2006 DV 2014 Baseline DV 2014 "Controlled" DV 

Bakersfield - California 18.51 15.86 14.28 

Bakersfield - Planz 18.86 16.26 14.70 

Bakersfield - Golden 18.64 15.98 14.39 

Clovis 16.39 14.10 12.72 

Corcoran 17.24 14.75 13.27 

Fresno - 1st Street 16.68 14.43 13.01 

Fresno - Hamilton 17.16 14.93 13.47 

Merced 14.69 12.85 11.76 

Modesto 14.10 12.52 11.44 

Stockton 12.93 11.77 10.87 

Visalia 18.20 16.05 14.47 

a. Design values equal to or below 15.04 μg/m3 meet the annual PM2.5 NAAQS. 

The weight-of-evidence analyses provide a consistent assessment that the San Joaquin 

Valley will attain the annual average PM2.5 standard throughout the Valley in 2014. 

Significant progress has already occurred, a 6 ug/m3 drop in annual average design 

value between 2001 and 2006, which represents two-thirds of the progress needed to 

attain the annual standard by 2014. Ammonium nitrate, ammonium sulfate, and carbon 

concentrations have responded positively to past reductions in NOx, SOx, and primary 

PM2.5 emissions. Substantial future emission reductions will occur due to both 

baseline commitments as well as new measures from NOx, and primary PM2.5 

emissions that have worked in the past. Linear rollback analysis indicates attainment in 

2014. Grid-based aerosol modeling also indicates attainment in 2014 at all sites in the 

District. However, attainment is expected to phase in starting in the northern portion of 

the Valley and spreading south, with more and more areas reaching attainment as we 

move towards 2014. As mentioned earlier, the mountains surrounding the Valley act as 

air flow barriers, with the resulting stagnant conditions favoring the accumulation of 

emissions and pollutants, making it harder for the southern portion of the Valley to reach 

attainment sooner. 

4. Attainment Date 

The Act requires nonattainment areas to attain the PM2.5 standards as expeditiously as 

practicable beginning in 2010, but no later than 2015. U.S. EPA guidance sets 2014 as 

the practical deadline for SIP planning purposes by requiring that the necessary 

emission reductions be achieved one year earlier. As required, the Plan identifies the 

proposed attainment date based on the severity of the PM2.5 problem and the 

availability and feasibility of control measures in the region. The District determined that 

feasible controls were not available to attain achieve the necessary emission reductions 

earlier than 2014. The State requests U.S. EPA approve April 5, 2015 as the deadline 
 

20 

consistent with its guidance that the SIP must provide for the necessary emission 

reductions by 2014. The request is based on: 

 the magnitude of the remaining PM2.5 challenge in the San Joaquin Valley, as 

reflected by monitoring data; 

 the significant amount of emission reductions required for reaching attainment 

o by 2014, on-going control programs will reduce direct PM2.5 emission by 

13% from 2005 emission levels. To reach attainment, new measures 

need to reduce direct PM2.5 emissions by an additional 15%, plus 

o on-going control programs will reduce NOx emission by 35 % from 2005 

emission levels. New measures need to reduce NOx emissions by an 

additional 15% to reach attainment; and 

 the control strategy in the SJV 2008 PM2.5 Plan includes the District and State 

control measures that are available and feasible within the proposed attainment 

timeframe. 

Considering the following factors, 2015 is identified as the earliest feasible attainment 

date: 1) baseline emission reductions that occur during the period up to 2014 are not 

sufficient alone to provide for attainment at all sites, and 2) the additional emission 

reductions resulting from the State Strategy will not phase in prior to 2014 due to the 

extraordinarily complex and innovative nature of developing and implementing these 

new measures. 

ARB staff concurs with the District’s assessment of the most expeditious and 

practicable attainment date for the San Joaquin Valley. As mentioned in the previous 

section, the results of the modeling and weight-of-evidence analyses, which include the 

impacts of control measures available and feasible at the District and State levels show 

the San Joaquin Valley will attain the PM2.5 standards in 2014. 

D. Control Strategy 

The SJV 2008 PM2.5 Plan integrates the NOx strategies adopted as part of the 

2007 Ozone Plan. Among the guiding principles for developing the control strategy, the 

District gives precedence to NOx, which is also an ozone precursor. However, 

recognizing the importance of directly emitted PM2.5, additional measures to address 

this component have also been included. Directly emitted PM2.5 emission reductions 

are approximately nine times more effective than NOx reductions in the attainment year

Overall, between 2005 and 2014, NOx emissions will decrease by almost 300 tons per 

day, direct PM2.5 emissions by over 20 tons per day, and SOx by almost 3 tons per 

day. Two thirds of the NOx and SOx reductions, and one half of the PM2.5 reductions 

come from already adopted measures. Figure 7 below illustrates the continuous 

progress in reducing NOx and PM2.5 emissions on the path towards attainment by 

2014. 
 

21 

Figure 7 

1. New District Measures 

a. Rule Development Commitment 

The Valley’s approved PM2.5 Plan contains the District’s commitment to develop and 

implement a suite of control measures for NOx, direct PM2.5, and SOx that in 

aggregate will achieve the total emission reductions specified in Table 6. Table 6 lists 

the 8 quantified measures, emission reductions in each reasonable further progress and 

attainment milestone years (2009, 2012, and 2014), and rule adoption timelines. By 

2014, the District measures will reduce emissions by 9.0 tons per day of NOx, 

6.7 tons per day of PM2.5, and 0.9 tons per day of SOx. Some of these measures may 

provide for additional emission reductions from other pollutants which are not quantified 

at this time. In addition, Table 7 lists 5 control measures for which the District has not 

specified emission reductions because work is currently underway to due to refine the 

emission inventory and assess current control efficiency. The District expects these 

measures to realize further emission reductions. All measures are to be developed by 

2010, with implementation no later than 2012. The Plan shows attainment without the 

potential benefits of the measures. 

The SJV 2008 PM2.5 Plan includes the 6 NOx control rules previously approved in the 

2007 Ozone Plan. The District has accelerated adoption and implementation of one of 

the control measures. In addition, the District has added a new NOx control measure 

based on equipment attrition. The District has also made progress on two of the 

feasibility study measures from the Ozone Plan so that these are now control measures 

in this Plan. 

Countdown to Attainment Levels

0

50

100

150

200

250

300

350

2005 2009 2012 2014

Emission Reduction Needed (tpd)

NOx PM2.5

All SIP reductions 

achieved 
22 

Table 6 

Summary of District Emission Reduction Commitments in the 2008 PM2.5 Plan 

(Annual Average Planning tons per day) 

Projected Redu

CM# Measure Name Completion Date Compliance Date Reduction Start 2009 2010 2011 

S-COM-5 Stationary Gas Turbines 2007 3Q 2012 2012 NOx 0 0 0 

NOx 0 0 0 

S-COM-1 PM2.5 0 0 0 

Boilers, Steam Generators and Process Heaters (>5 MM Btu/hr) 

2008 3Q 2012 2012 

SOx 0 0 0 

S-COM-7 Glass Melting Furnaces 2008 3Q 2009 2009 NOx 1.22 1.25 1.18 S-COM-9 Residential Water Heaters 2009 1Q Attrition 2011 NOx 0 0 0.20 S-IND-9 Commercial Charbroiling 2009 2Q 2011 2011 PM2.5 0 0 2.17 

NOx 0 0.04 0.08 

PM2.5 0 0.39 0.76 

S-COM-14 

Wood Burning Fireplaces and Wood Burning Heaters 

2009 3Q 2010 2010 

SOx 0 0.01 0.02 

S-COM-3 

Boilers, Steam Generators and Process Heaters (0.075 to <2 MMBtu/hr) 

2009 4Q 2011 2011 NOx 0 0 0.12 

NOx 1.21 1.95 2.68 

S-AGR-1 Open Burning 2010 2Q 2010 2009 PM2.5 1.60 2.57 3.53 

SOx 0.06 0.10 0.14 

TOTAL NOx REDUCTIONS 2.43 3.24 4.26 

TOTAL PM2.5 REDUCTIONS 1.60 2.96 4.46 

TOTAL SOx REDUCTIONS 0.06 0.11 0.16 
 

23 

Table 7. Implementation Schedule of Additional District Control Measures 

CM# Measure Name Completion 

Date 

Compliance 

Date 

Reduction 

Start 

S-COM-2 

Boilers, Steam Generators 

and Process Heaters 

(2 to 5 MMBtu/hr) 

2008 3Q 2012 2012 

S-IND-21 Flares 2009 2Q 2010 2010 

M-TRAN-1 Employer Based Trip 

Reduction Programs 2009 4Q 2012 2011 

S-COM-10 Natural Gas-Fired, Fan Type 

Residential Central Furnace 2010 2Q Attrition 2012 

S-COM-6 Reciprocating Internal 

Combustion Engines 2010 4Q 2012 2012 

The SJV 2008 PM2.5 Plan also identifies 11 future study measures, which upon 

completion, could result in opportunities for additional emission reductions. These study 

measures seek to explore where and how additional reductions may be achieved in the 

future. The District is committing to release study reports by the dates listed in Table 8 

and to incorporate additional measures identified as fruitful in future PM2.5 plans. The 

Plan shows attainment without the potential benefits of these measures. 

Table 8. District Stationary Source Feasibility Study Implementation Schedule 

CM# Measure Name Completion 

Date 

S-AGR-2 Conservation Management Practices 2010 

S-COM-4 Solid Fuel Boilers Steam Generators, Process Heaters 2009 

S-COM-6A Small Spark-Ignited Engines and Agricultural Spark-Ignited 

Engines 2008 

S-COM-8 Lime Kilns 2011 

S-COM-11 Dryers 2011 

S-GOV-6 Prescribed Burning 2008 

S-IND-8 Cotton Gins 2009 

S-IND-4 Fugitive PM10 Prohibitions (Regulation VIII) 2009 

M-OTH-8 Indirect Source Review (ISR) Enhancement 2010 

M-OTH-9 Healthy Air Living TBD 

M-OTH-10 Fireworks 2012 
 

24 

ARB staff reviewed the District’s rule development commitments and considered 

comments received regarding further opportunities for emission reductions. On a 

case-by-case basis, staff considered emission sources, their distribution in the 

San Joaquin Valley, and the applicability of emission control approaches to the different 

types of sources. A summary of staff’s findings for specific source categories follows: 

Glass Melting Furnaces 

The Plan includes rule development commitment S-COM-7 with adoption scheduled in 

the third quarter of 2008. The District has already released a draft rule for public 

comment and held a public workshop on February 8, 2008. As currently proposed, the 

rule would result in greater NOx reductions than those estimated in the Plan for 

S-COM-7, as well as those cited in public comments. 

Internal Combustion (IC) Engines 

The District’s current rule for IC engines is comparable to other IC engine rules in 

California. The Plan includes rule development commitment S-COM-6 for 

non-agricultural (non-ag) IC engines, with adoption scheduled in the fourth quarter of 

2010. In the ozone plan, S-COM-6 was listed as a feasibility study to be completed in 

2012. In addition, the Plan includes feasibility study S-COM-6A for agricultural (ag) IC 

engines to be conducted in 2008. The District is considering the more stringent South 

Coast IC Engine Rule 1110.2 which sets requirements in common for both ag and nonag IC engines, but applies to very few ag IC engines. The cost-effectiveness and 

feasibility of electrifying all engines will need to be carefully evaluated with consideration 

of the availability of electricity in some of the more rural areas in the Valley. 

Dryers 

The District recently adopted a rule for large dryers. In the Plan, the District commits to 

further studying control options for small dryers in 2011 (feasibility study S-COM-11). 

Existing control technology may not be applicable to all small dryers. The South Coast 

Ozone/PM2.5 Plan includes a proposed control measure for small dryers, but considers 

that pursuing emission reductions as part of a measure requiring facilities to modernize 

equipment and processes with materials complying with the best available controls 

would be a better fit. 

Large Boilers - rated 5 MMBTU/HR and above 

The Plan includes rule development commitment S-COM-1 with adoption in the third 

quarter of 2008. The District has already released a draft rule for public comment and 

held a public workshop on March 1, 2008. The draft rule sets NOx emission limits 

which can be met with Selective Catalytic Reduction or ultra-low NOx burners. As 

proposed, rule implementation would result in greater reductions than those estimated 

in the Plan. 

Medium Boilers-rated 2-5 MMBTU/HR 

The Plan includes rule development commitment S-COM-2 with adoption scheduled in 

the third quarter of 2008. The District has already released a draft rule for public 

comment and held a public workshop on March 17, 2008. The draft rule proposes 
 

25 

removing the exemption for school boilers by initially controlling them through an 

incentive funding program. 

Small Boilers-rated 0.75-2 MMBTU/HR 

The Plan includes rule development commitment S-COM-3 with adoption scheduled in 

the fourth quarter of 2009. The District is considering accelerating the replacement of 

old units by 5 percent and exploring electrification. In the ozone plan, S-COM-3 was 

listed as a feasibility study to be completed in 2010. 

Solid Fueled Boilers 

The Plan includes feasibility study S-COM-4 to be conducted in 2009. The Valley 

sources currently operate with selective non-catalytic reduction with ammonia injection. 

The District will consider emission limits in the Sacramento AQMD rule, as previously 

recommended by ARB staff, and will evaluate the applicability of Selective Catalytic 

Reduction. 

Prescribed Burning 

The San Joaquin Valley’s existing Smoke Management Program does not allow 

agricultural field burns to occur when air quality is forecasted to be unhealthy. The Plan

includes feasibility study S-GOV-6 to be completed in 2008. As part of the study, the 

District will analyze incentive options and will examine alternatives to burning. 

Wood Burning Fireplaces and Wood Burning Heaters 

The Plan includes rule development commitment S-COM-14 with adoption scheduled in 

the third quarter of 2009. The District is considering strengthening the rule by lowering 

the threshold of their mandatory curtailment program. The current rule has been pivotal 

in reducing the PM2.5 impacts of residential burning and key to the Valley attaining the 

federal PM10 standard. 

Other suggestions were to also address VOCs and fugitive dust control measures. 

However, reductions in VOC emissions are not effective in reducing PM2.5 

concentrations in the Valley. Photochemical modeling analyses conducted in support of 

the Plan show that the secondary organic component contributes less than 0.5 percent 

to the organic carbon fraction of PM2.5. In addition, more recent precursor sensitivity 

analyses show that ammonium nitrate formation is not VOC, but rather NOx limited. As 

mentioned earlier, chemical composition analyses of ambient air quality monitoring 

samples show that dust is a small component of measured PM2.5 and therefore, dust 

controls would not be effective in accelerating PM2.5 attainment. However, it remains 

useful to conduct feasibility studies to gather better information on dust emitting 

sources. 

b. Incentive-based Strategies 

In the attainment demonstration, the SJV 2008 PM2.5 Plan also includes emission 

reduction benefits of District incentive programs for which funding has been secured. 

As part of the 2007 Ozone Plan, the District committed to specific incentive-based NOx 

reductions in 2012, 2020 and 2023. The SJV 2008 PM2.5 Plan takes credit for the 
 

26 

2012 emission reduction commitment of 1.4 tpd NOx. These emission reductions are 

funded through a combination of Indirect Source Review fees, Developer Mitigation 

Contract fees, and Department of Motor Vehicle Surcharge fees. Carl Moyer Program 

reductions are not credited here, as they are included in the ARB baseline emission 

adjustments. 

In addition, the District lists potential future incentive funding that can be used for air 

quality programs and may lead to “SIP creditable” emission reductions. Among these is 

the Proposition 1B: Goods Movement Emission Reduction Program. On 

February 28, 2008, ARB approved the first distribution of the funds under this program. 

2. Adopted State Strategy 

Cleaning up the mobile source NOx and PM2.5 sources is the most critical component 

of the State’s emission control effort to reduce PM2.5 concentrations in the Valley. 

Vehicles and equipment operating in California are subject to the most stringent tailpipe 

emission standards in the world. ARB has a long history of adopting successful 

programs to reduce emissions from mobile sources. These regulations will result in 

fewer emissions as vehicles and equipment units meeting the cleanest emission 

standards enter into service. However, the benefits of these cleanest engines are only 

realized as new engines enter service and older engines are retired, and diesel engines 

have very long useful lives. 

On September 27, 2007, ARB adopted the 2007 State Strategy to achieve new 

emission reductions needed to bring areas of the State into attainment of both the 

federal PM2.5 and ozone air quality standards. The commitment for 2014 in the State 

Strategy includes reductions needed to attain the PM2.5 standards and provide 

progress towards meeting the ozone standard. The San Joaquin Valley is relying on 

NOx, SOx, and direct PM2.5 emission reductions for PM2.5 attainment. 

Table 9 summarizes the estimated benefits for 2014 in the San Joaquin Valley from the 

mix of concepts in the 2007 State Strategy. The potential emission reduction benefits of 

individual measures are provided for informational purposes only. Additional details on 

the individual measures are available in the 2007 State Strategy, which is available online at: http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm 
 

27 

Table 9. Expected Emission Reductions from 2007 SIP State Strategy 

(tons per day) 

San Joaquin Valley -- 2014 

Proposed New State SIP Measures NOx ROG Direct 

PM2.5 SOx 

Passenger Vehicles 3.8 6.5 0.1 -- 

 Smog Check Improvements (BAR) 3.3 2.9 0.05 -- 

 Expanded Vehicle Retirement 0.5 0.7 0.01 -- 

 Modifications to Reformulated Gasoline Program -- 2.9 -- -- 

Heavy-Duty Trucks 61.4 6.4 3.6 -- 

 Cleaner In-Use Heavy-Duty Trucks 61.4 6.4 3.6 -- 

Goods Movement Sources 7.2 0.5 0.2 -- 

 Ship Auxiliary Engine Cold Ironing & Clean Technology -- -- -- -- 

 Cleaner Main Ship Engines and Fuel -- -- -- -- 

 Port Truck Modernization -- -- -- -- 

 Accelerated Introduction of Cleaner Line-Haul Locomotives 7.2 0.5 0.2 -- 

 Clean Up Existing Harbor Craft -- NYQ -- -- 

Off-Road Equipment 3.7 0.9 0.8 -- 

 Cleaner In-Use Off-Road Equipment (over 25hp) 3.7 0.9 0.8 -- 

 Cleaner In-Use Agricultural Equipment NYQ NYQ NYQ -- 

Other Off-Road Sources 0.1 3.5 -- -- 

 New Emission Standards for Recreational Boats 0.1 1.3 -- -- 

 Expanded Off-Road Rec. Vehicle Emission Standards -- 2.2 -- -- 

 Additional Evaporative Emission Standards -- NYQ -- NYQ 

 Vapor Recovery for Above Ground Storage Tanks -- NYQ -- NYQ 

Areawide Sources -- 5.7 -- -- 

 Consumer Products Program -- 3.2 -- -- 

 Pesticides: DPR Regulation -- 2.5 -- -- 

 Reductions from Proposed New State Measures 76 23 5 0 

 Reductions from Adopted State Measures 211 49 7 0 

 Total Emission Reductions from State Strategy 287 72 12 0 

NYQ = Not Yet Quantified. BAR = Bureau of Automotive Repair. DPR = Dept. of Pesticide Regulation 

Locomotives measure relies on U.S. EPA’s rulemaking and industry agreement to accelerate fleet 

turnover. 

Note: Emission reductions reflect the combined impact of regulations and supportive incentive programs. 

Emission reduction estimates for each proposed measure are shown for informational purposes only. 

Actual emission reductions from any particular measure may be greater than or less than the amounts 

shown. 
 

28 

E. Reasonable Further Progress 

The Act requires SIPs to provide for steady progress in reducing emissions during the 

years leading to the attainment date. This requirement provides a way to ensure 

continuous reductions prior to the attainment date. For PM2.5, U.S. EPA requires that 

the RFP plan show generally linear progress7 for the precursor pollutants identified in 

the attainment demonstration, in this case, direct PM2.5, NOx, and SOx. Since the 

Valley will be in attainment in 2014, 2009 and 2012 are milestone years for RFP. 

Table 10 shows projected emission levels, showing continuous progress towards the 

attainment levels. 

Table 10. Projected Emission Levels in Milestone Years 

(in tpd) 

Milestone 

Year Direct PM2.5 NOx SOx 

2005 86.0 575.4 26.4 

2009 78.2 498.5 22.9 

2012 70.3 415.8 22.9 

2014 63.3 291.2 23.6 

The SJV 2008 PM2.5 Plan meets RFP by achieving generally linear emission 

reductions towards attainment in 2014 for direct PM2.5 and NOx from the 2005 baseline 

year through the milestone years 2009 and 2012. Percent year decreases in PM2.5 

emissions range from 2 to 3 percent and in NOx emissions from 3 to 5 percent. SOx 

emissions in both milestone years are below the attainment level. 

F. Contingency Measures 

The Act requires attainment plans to provide for contingency measures in the event the 

nonattainment area fails to make RFP or fails to attain the PM2.5 standard by its 

attainment date. These contingency measures are to take effect without further ARB or 

District action. U.S. EPA has interpreted this to mean that the contingency measures 

must be from the pool of already adopted measures. The PM2.5 implementation rule 

language does not require any set percent of emission reductions for contingencies8

. 

ARB’s on-going mobile source program and the new measures in the State Strategy will 

achieve the bulk of the emission reductions needed to attain the standards in the 

San Joaquin Valley. Historically, ARB’s mobile source program has been very 

successful in reducing emissions in the Valley and throughout California. In addition, 

ARB has a well established record of adopting and implementing mobile source 

regulations on time. The methods used in the SJV 2008 PM2.5 Plan to calculate 

emission reductions needed to meet the RFP goals withheld reductions from the 

 

7

 72 FR 20633 

8

 72 FR 20667 
 

29 

on-going mobile source control program as contingencies (SJV 2008 PM2.5 Plan, 

Chapter 8). For 2009 and 2012 RFP, 1 percent of PM2.5 and 3 percent of NOx 

baseline emissions are being reserved as contingencies, which result in reductions of 

about 1 tpd of PM2.5 and about 17 tpd of NOx. For attainment, the 2015 baseline 

emission reductions are relied upon to meet the contingency requirements. For NOx, 

baseline emission reductions provide for an additional 21 tpd in 2015. Between 2015 

and 2017, an additional 60 tpd of additional NOx reductions will be achieved for 

contingency purposes. 

The District supplements these contingency reductions with two additional contingency 

measures. These measures rely on fee- and incentive-based funding that the District 

will spend to achieve emission reductions. Funding sources include the federallymandated 1-hour ozone nonattainment fee and incentive programs such as the Carl 

Moyer Program and Proposition 1B. 

G. Reasonably Available Control Measure Analysis 

Section 172 (c) of the Act requires each nonattainment area to demonstrate that it has 

adopted all reasonably available control measures (RACM), including reasonably 

available control technologies (RACT) for stationary sources, necessary to show that it 

will attain the federal standards as expeditiously as practicable and to meet RFP 

requirements. RACM and RACT are those measures that are technologically and 

economically feasible within the nonattainment area. As part of the RACM/RACT 

demonstration, the District must show that there are no additional reasonable measures 

available to the District that, when considered in aggregate, would advance the 

attainment date by at least one year. In PM2.5 plans, the RACM/RACT analysis must 

address direct PM2.5, NOx and SOx. 

1. District RACM 

The SJV 2008 PM2.5 Plan includes the District’s RACM and RACT demonstration for 

direct PM2.5, NOx and SOx. The District followed U.S. EPA guidance for evaluating 

potential control measures as RACM. This RACM demonstration includes a 

comparison of stationary source measures the District has implemented or plans to 

implement with U.S. EPA’s list of suggested PM2.5 control measures. A detailed 

description of the District’s RACM analysis is found in Chapter 6 of the Plan. ARB staff 

has reviewed the analysis and concurs that the federal RACM/RACT requirement is 

met. 

2. Metropolitan Planning Organizations RACM 

Following U.S. EPA guidance in their RACM analysis, the Valley’s Metropolitan 

Planning Organizations (MPO’s) conducted a review of Transportation Control 

Measures (TCMs) for possible consideration as local RACM. The analysis built on the 

MPO’s previous RACM analysis for the 2007 Ozone Plan and focused on NOx. The 

analysis found that the potential TCMs identified will not advance PM2.5 attainment by a 
 

30 

full year, thus the SJV 2008 PM2.5 Plan does not include commitments to adopt any 

TCM. 

H. Transportation Conformity Budgets 

Under section 176(c) of the Act, transportation activities that receive federal funding or 

approval must be fully consistent with the SIP. U.S. EPA’s transportation conformity 

rule9

 details requirements for establishing motor vehicle emission budgets (budgets) in 

SIPs for the purpose of ensuring the conformity of transportation plans and programs 

with the SIP. The budgets act as a “ceiling” for future on-road mobile source emissions. 

Exceedances of the budgets indicate an inconsistency with the SIP, and could 

jeopardize the flow of federal funds for transportation improvements in the region. 

Transportation agencies compare projected regional on-road mobile source emissions 

to these budgets during the periodic updates of regional transportation plans and 

programs. 

The SJV 2008 PM2.5 Plan establishes county-level on-road motor vehicle emission 

budgets for each milestone year, as well as for the attainment year (Table 11). 

Emission budgets for direct PM2.5 and the PM2.5 precursor NOx, were calculated using 

EMFAC2007 and reflect annual average emissions. Detailed calculations used to 

derive the transportation conformity budgets can be found in Chapter 7 and Appendix C 

of the SJV 2008 PM2.5 Plan. The emission budgets established in the SJV 2008 

PM2.5 Plan fulfill the requirements of the Act and U.S. EPA regulations to ensure that 

transportation projects will not interfere with progress and attainment of the annual 

PM2.5 standard. 

 

9

 U.S. EPA maintains online information on its transportation conformity program, including access to 

relevant rulemakings, policy guidance, and reports at: http://www.epa.gov/otaq/transp/traqconf.htm
 

31 

Table 11. Transportation Conformity Budgets 

(tons per annual average day) 

2009 2012 2014 

County PM2.5 

(tpd) 

NOx 

(tpd) 

PM2.5 

(tpd) 

NOx 

(tpd) 

PM2.5 

(tpd) 

NOx 

(tpd) 

Fresno 2.2 56.5 1.9 44.2 1.1 26.0 

Kern 

(SJV) 

3.4 87.7 3.0 74.2 1.4 41.6 

Kings 0.7 17.9 0.6 14.6 0.3 8.1 

Madera 0.6 14.1 0.5 11.4 0.3 6.7 

Merced 1.5 33.6 1.2 26.7 0.6 14.8 

San 

Joaquin 

1.6 39.1 1.4 32.8 0.9 20.3 

Stanislaus 1.0 25.8 0.9 20.8 0.5 12.4 

Tulare 0.9 23.3 0.8 19.5 0.5 12.2 

I. Environmental Impacts 

The California Environmental Quality Act (CEQA) requires that State and local agency 

projects be assessed for potential significant environmental impacts. Air quality plans 

are “projects” that are potentially subject to CEQA requirements. The District staff found 

that the Plan would not have a significant effect on the environment and prepared an 

Initial Study/Negative Declaration. The District Governing Board approved this Initial 

Study/Negative Declaration on April 30, 2008. 

IV. STAFF RECOMMENDATION 

We recommend that the Board take the following actions: 

1. Adopt the SJV 2008 PM2.5 Plan, including the emission inventory, local control 

strategy, attainment demonstration, attainment deadline request, reasonable 

further progress plan, contingency measures, RACT/RACM demonstration, 

transportation conformity emission budgets, and the commitment to conduct a 

mid-course review, as a revision to the California SIP 

2. Direct the Executive Officer to submit the SJV 2008 PM2.5 Plan to U.S. EPA as a 

revision to the California SIP.