State of California

 California Environmental Protection Agency

 AIR RESOURCES BOARD

Staff Report

San Joaquin Valley 2013 Plan for the Federal 

1-Hour Ozone Standard

Release Date: November 8, 2013

Meeting Date: November 21, 2013
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/planarea/sanjqnvllysip.htm

In addition, written copies may be obtained from the Public Information Officer, 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:

Mr. Webster Tasat

Manager, Central Valley Air Quality Planning Section

Phone: (916) 323-4950

Email: wtasat@arb.ca.govU4 T

Or

Ms. Elizabeth Melgoza

Project Lead

Phone: (916) 322-6161

Email: emelgoza@arb.ca.govU4T
TABLE OF CONTENTS

I. INTRODUCTION ......................................................................................... 1

II. NATURE OF THE OZONE PROBLEM IN THE SAN JOAQUIN VALLEY ... 2

A. Ozone Health Effects.............................................................................. 2

B. Geography and Population..................................................................... 2

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

III. CLEAN AIR ACT REQUIREMENTS............................................................ 6

A. Emissions Inventory................................................................................ 6

B. Reasonably Available Control Measure Analysis and Control Strategy.. 6

C. Demonstrating Attainment ...................................................................... 7

1. Modeling Approach and Results........................................................ 8

2. Weight of Evidence ........................................................................... 9

D. Rate of Progress Demonstration............................................................. 9

E. Contingency Measures........................................................................... 10

F. Clean Fuels and Clean Technologies for Boilers.................................... 11

G. VMT Offset Demonstration ..................................................................... 11

IV. ENVIRONMENTAL IMPACTS ..................................................................... 12

V. STAFF RECOMMENDATION...................................................................... 12

APPENDICES

Appendix A - District submittal letter and Governing Board Resolution

Appendix B - Link to District 2013 1-hour Ozone Plan
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I. INTRODUCTION

The San Joaquin Valley Air Pollution Control District (District) adopted the 2013 Plan for 

the 1-Hour Ozone Standard (2013 Plan) on September 19, 2013. The 2013 Plan 

demonstrates that the San Joaquin Valley will attain the federal 1-hour ozone standard 

by 2017. The Air Resources Board (ARB or Board) will consider approval of the 2013 

Plan at a public meeting on November 21, 2013, and, if adopted, the 2013 Plan will be

submitted to the U.S. Environmental Protection Agency (U.S. EPA) for approval as a 

revision to California’s State Implementation Plan (SIP).

U.S. EPA established the 1-hour ozone standard and originally classified the San 

Joaquin Valley as a serious nonattainment area. Due to the severity of the air quality 

problem, U.S. EPA subsequently reclassified the Valley as extreme nonattainment and 

set 2010 as the deadline for attainment. In 2004, the District prepared the Extreme 

Ozone Attainment Demonstration Plan (2004 Plan), which identified a comprehensive 

emission reduction strategy aimed at bringing the Valley into attainment by 2010. 

In 2005, U.S. EPA revoked the 1-hour ozone standard due to promulgation of the more 

health protective 8-hour ozone standard. However, certain planning obligations 

associated with the 1-hour ozone standard still remain and court action in 2011 led to a 

finding that the San Joaquin Valley did not attain by the 2010 deadline. U.S. EPA 

subsequently withdrew approval of the 2004 Plan in 2012. To meet its extreme area 

SIP obligations, the District has now prepared the 2013 Plan, demonstrating attainment 

of the 1-hour ozone standard by 2017.

Since development of the 2004 Plan, ARB and the District have adopted comprehensive 

new control strategies focused on meeting the more stringent 8-hour ozone standard. 

These strategies will result in significant reductions of ozone forming precursors and 

establish the basis for bringing the Valley into attainment for the 1-hour ozone standard. 

Emissions of oxides of nitrogen (NOx) and volatile organic compounds (VOC) are 

expected to decrease 49 and 20 percent, respectively, between 2007, the base year of 

the 2013 Plan, and 2017 as a result of ARB and District measures designed to meet the 

8-hour ozone standard. 

The 2013 Plan addresses all applicable Clean Air Act (CAA) requirements for an 

extreme nonattainment area:

• Summer season emission inventory; 

• Reasonably available control measures (RACM) demonstration for existing sources;

• Attainment demonstration for 2017; 

• Rate-of-progress demonstration; 

• Contingency measures;

• Provisions for clean fuels/technologies for boilers; and,

• Vehicle Miles Traveled (VMT) offset demonstration.

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II. NATURE OF THE OZONE PROBLEM IN THE SAN JOAQUIN VALLEY

This chapter provides a brief overview of ozone health impacts, the geography and

meteorology which contribute to ozone formation, and a summary of ozone air quality 

progress.

A. Ozone Health Effects

Ozone is a highly reactive gaseous pollutant formed by the photochemical reaction of 

VOCs with NOx and other reactive species. Exposure to levels of ozone above the 

standard can have deleterious effects on human health and typically include symptoms 

such as coughing, chest tightness, shortness of breath, and the worsening of asthma. 

U.S. EPA originally established a 1-hour ozone standard in 1979, setting the level at 

120 parts per billion (ppb). In 1997, U.S. EPA promulgated a more health protective 

8-hour ozone standard, and subsequently revoked the 1-hour ozone standard in 2005. 

B. Geography and Population

The San Joaquin Valley Air Basin includes San Joaquin, Stanislaus, Merced, Madera, 

Fresno, Kings, Tulare, and Western Kern Counties (Figure 1) and is approximately

25,000 square miles or about 16 percent of the area of California. It is a continuous valley

approximately 250 miles long and averaging 80 miles wide. Mountains bound the area on

the west (Coastal Mountain range), the east (Sierra Nevada range), and the south

(Tehachapi Mountains). 

The major urban centers in the San Joaquin Valley are Bakersfield, Fresno, Modesto,

and Stockton. Emissions associated with large urban areas, coupled with the Valley’s 

geography and meteorology, are conducive to the formation and retention of high levels 

of ozone. The surrounding mountain ranges and stagnant weather patterns typically 

prevent the dispersal of air pollutants. During the summer when low winds, lack of 

precipitation, and high temperatures are prevalent elevated ozone levels are common. 

The current population of the San Joaquin Valley is four million. Based on the latest 

data from the California Department of Finance, the region’s population is expected to 

increase to 4.4 million by 2017. This anticipated increase in Valley residents adds to

the complexity of the ozone problem. Population growth leads to an increase in

automobile and truck travel as well as an increase in the use of consumer products. 

Total vehicle miles traveled (VMT) for example, is expected to increase about 

21 percent between 2010 and 2020. 

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Figure 1. San Joaquin Valley

C. Air Quality Progress

The San Joaquin Valley has one of the most challenging ozone problems in the nation. 

In the early 1990s, much of the Valley exceeded the 1-hour ozone standard, and 

exceedances of the standard occurred somewhere in the Valley 50 days each summer. 

However, ozone air quality has improved throughout the region, with the basinwide

design value declining by 21 percent between 1995 and 2012, and the number of 

exceedance days declining by more than 90 percent. 

Figure 2 illustrates the trend in the basinwide design value, the statistic used to 

determine compliance with the standard. The annual values represent four different 

monitoring sites, as the highest design value in the Valley has occurred at different 

locations from year to year. Over the last 18 years, the high site has alternated 

between the central Valley (Clovis or Parlier or Fresno-Drummand), and the southern 

Valley (Edison or Arvin-Bear Mountain). 

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Exceedances are now limited to a smaller window of time than in the past. In the 

1990s, exceedance days typically occurred between April and October. In recent years,

the few remaining days over the 1-hour ozone standard occur predominantly during the

months of June to September. 

Figure 3 also illustrates the progress that has been made in reducing the spatial extent of 

exceedance days in the Valley. In 1993-1995, portions of the central and southern Valley 

experienced 15 to 25 exceedance days. As of 2010-2012, only a few areas in the central 

and southern Valley recorded exceedance days, and only two sites, Fresno-Drummond

and Clovis, had design values above the standard. In 2013, no site in the Valley recorded 

an exceedance of the 1-hour ozone standard. As a result, the Clovis site now meets the 

standard. With just one exceedance beyond the three allowed under the form of the 

standard, the Fresno-Drummond site is now the only remaining site violating the standard. 

In 2010, the Arvin-Bear Mountain monitoring site was relocated to the nearby Di Giorgio 

Elementary School as ARB was unable to renew the lease at this location. 

Concentrations at the Di Giorgio Elementary School during monitoring site comparison 

work conducted in 2010 were lower than those measured at Arvin-Bear Mountain. 

To further evaluate the variability in concentrations in the Arvin region, the District 

conducted a saturation monitoring study during the summer of 2013. The results of this 

study will provide the information necessary for ARB, the District, and U.S. EPA to 

assess approaches for evaluating the near-term attainment status related to the 1-hour 

ozone standard, as well as determine longer-term needs for the 8-hour ozone standard.

0.110

0.120

0.130

0.140

0.150

0.160

0.170

1995199619971998199920002001200220032004200520062007200820092010201120122013

Highest Design Value for the Year (ppm)

Figure 2. Design Value Trend for the San Joaquin Valley Air Basin

Basinwide Design Value Level of Standard

*2013 value is preliminary

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Figure 3. Reductions in Exceedance Days in the San Joaquin Valley Air Basin (1993-1995 vs. 2010-2012)

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III. CLEAN AIR ACT REQUIREMENTS

The CAA requires California to submit the following documentation specific to the 

San Joaquin Valley to address the 1-hour ozone standard:

• Base year emission inventories and future year forecasts for manmade sources 

of air pollution in the nonattainment area; 

• Reasonably available control measures (RACM) demonstration for existing sources;

• Attainment demonstration; 

• Rate-of-progress demonstration; 

• Contingency measures;

• Provisions for clean fuels/technologies for boilers; and,

• VMT offset demonstration.

A. Emission Inventory

California’s emission inventory is an estimate of the amounts and types of pollutants 

emitted over a given time period from industrial and commercial facilities, mobile 

sources, and area-wide sources, including emissions from the application of paint and 

consumer products. The development and maintenance of California’s emission 

inventory is a multi-agency effort involving ARB, 35 local air pollution control and air 

quality management districts, metropolitan planning organizations (MPOs), councils of 

governments (COGs), and the California Department of Transportation (Caltrans). The 

emission inventory compiled by ARB staff reflects the best information available about 

the emission rate and activity for each category of emission sources and includes the 

projected growth in emissions into the future.

The 2013 Plan uses the latest estimates of VOC and NOx emissions for stationary, 

area-wide, and on-road/off-road mobile sources. SIPs demonstrating attainment of the 

1-hour ozone standard must contain base-year emission inventories and future year

forecasts for NOx and VOC. ARB and District staff worked jointly to develop a

comprehensive emission inventory for the 2013 Plan. 

The Valley’s attainment challenges under the 1-hour ozone standard occur in the

summer months. For this reason, the 2013 Plan focuses on summer average daily 

emission inventories, with emissions presented in tons per day (tpd). Based on the 

most updated forecasting methodology, including the use of category-specific growth 

profiles, NOx emissions are expected to decrease by 49 percent and VOC emissions by 

20 percent between 2007, the base year for the 2013 Plan, and 2017. 

B. Reasonably Available Control Measure Analysis and Control Strategy

As specified in the CAA, SIPs shall provide for the implementation of all RACM as

expeditiously as practicable. 

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The District has adopted hundreds of new rules and rule amendments over the last two 

decades. Many of these rules were adopted since the 2004 Plan and are included in 

more recent air quality planning to address the 8-hour standard. Consistent with its 

regulatory authority, the District has adopted rules focused on controlling emissions from 

stationary and area sources, such as boilers, steam generators, process heaters, flares, 

open burning, architectural coatings, commercial charbroiling, and confined animal 

facilities. ARB has adopted stringent regulations to reduce emissions from heavy-duty 

trucks, off-road equipment, and other mobile sources. Collectively, these control 

measures adopted by the District and ARB will continue to provide benefits by reducing

ozone-forming precursor emissions through 2017 and beyond. 

Given the significant emission reductions needed for attainment in California, ARB has 

adopted the most stringent control measures nationwide for on-road and off-road mobile

sources and the fuels that power them. These measures, all of which are considered 

RACM, provide a significant amount of emission reductions needed for the Valley to

attain the 1-hour ozone standard. 

The District is also required to implement reasonably available control technology

(RACT) for sources that are subject to control techniques guidelines issued by U.S. EPA

and for major sources of VOCs and NOx. U.S. EPA has approved District rules 

contained in the 2009 RACT SIP and has concurred that District rules are at least as

stringent as RACT levels. The District has included an updated RACT demonstration for 

the 2013 Plan. 

The District is evaluating potential control measure opportunities to continue ozone air 

quality progress. Additional information and studies regarding current emission 

inventories, the effectiveness of the current controls, and future technologies are all 

efforts the District is pursuing. The District identified commitments for further study 

measures in the 2012 PM2.5 Plan and continued that commitment in the 2013 Plan. 

These further study measures include: open burning, prescribed burning, flares, 

architectural coatings, storage of organic liquids, transfer of organic solids, bakery 

ovens, lawn care equipment, asphalt and concrete operations and ongoing study and 

research. 

C. Demonstrating Attainment

The CAA requires the use of air quality modeling to relate ozone levels to emissions in a 

region and simulate future air quality based on changes in emissions. Modeling uses 

emission inventories, with measurements of meteorology and air quality, to establish 

this relationship. The performance of the model is assessed by comparing the modeled 

or predicted ozone value to the monitored or observed ozone level in a base year. 

This modeling is used to identify the benefits of controlling different ozone precursor 

pollutants and the most expeditious attainment date. 

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1. Modeling Approach and Results

Consistent with U.S. EPA guidelines, ARB modeled air quality to predict future 1-hour 

ozone concentrations at each monitoring site in the Valley. The modeling results meet 

the performance criteria established by U.S. EPA. The modeling used a base year of

2007, and a future year of 2017. The 2017 attainment year is consistent with the

attainment timeframe specified in the CAA, which allows up to five years to attain after a 

finding of nonattainment. 

Following U.S. EPA guidance for the 8-hour ozone standard, ARB used Relative

Response Factors (RRFs) to demonstrate attainment of the 1-hour ozone standard. 

The RRFs are calculated as the ratio of future-year and base-year ozone concentrations

for each site. The RRF is then multiplied by a site-specific design value to estimate the 

future-year design value. The traditional RRF-based approach is to multiply each site’s 

design value by an average RRF to determine the future design value for demonstrating

attainment. 

However, because higher ozone values (greater than 100 ppb) are more responsive to

emission controls than lower values, a modified approach was developed to construct

RRF’s for bands of concentrations and to apply this information in the determination of

future design values. These “band-RRFs” represent the model’s response to similar 

concentrations averaged over different meteorological and emission conditions. The

future design values calculated based on the band-RRFs are compared with the 1-hour 

ozone standard to determine the attainment status for each monitor. The benchmark for 

attainment is a design value that is equal to or less than 124 ppb.

This modeling shows that all sites in the Valley will attain the 1-hour ozone standard by

2017 based on implementation of the ongoing control program (Table 1) including the 

Arvin-Bear Mountain site. The highest predicted future site, Edison, is 4.7 ppb below the

standard, and other sites are 20.3 to 41.6 ppb below the standard. Therefore, the air 

quality simulations predict that the entire Valley attains the standard by 2017. 

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Table 1. Base Year and Future Year 1-Hour Ozone Design Values (ppb)

Monitoring Station DV (2005 -2007) DV (2017)

Edison 135 119.3

Fresno-1st 130 103.7

Arvin-Bear Mountain 131 107.4

Clovis 125 104.1

Fresno-Sierra 124 98.8

Parlier 121 97.4

Sequoia- Kings 118 102.4

Modesto 109 95.9

Bakersfield-California 117 98

Fresno-Drummond 110 93

Sequoia Natl Park 113 98.5

Hanford 110 92.6

Oildale 112 95.2

Bakersfield-Golden 108 96.3

Visalia 112 94.5

Turlock 104 91.8

Stockton 101 86.3

Shafter-Walker 105 87.7

Merced 102 85.4

Maricopa 100 83.5

Madera 95 82.4

2. Weight of Evidence

U.S. EPA modeling guidance requires that the modeled attainment demonstration be 

accompanied by a weight of evidence analysis to provide a set of complementary 

analyses. Examining an air quality problem in a variety of ways provides a more 

informed basis for the attainment strategy as well as a better understanding of the 

overall problem and the level and mix of emissions controls needed for attainment.

Appendix G of the District’s 2013 Plan provides the full weight of evidence analysis 

conducted by ARB staff. Following U.S. EPA guidance, this includes assessment of 

trends in air quality and emissions, source-receptor models and other diagnostic 

analyses, additional modeling evaluations, and description of a conceptual model of 

ozone in the Valley.

D. Rate of Progress Demonstration

The purpose of the rate-of-progress (ROP) demonstration is to ensure that

nonattainment areas make steady progress reducing emissions toward their attainment

goals. The 2013 Plan must show an average of three percent annual reductions of VOC 

9
or NOx in milestone years (every three years) after the baseline year until the attainment

year. Since the baseline year for this Plan is 2007; the milestone years are 2010, 2013,

2016, and 2017, the attainment year. The ROP demonstration in the District 2013 Plan 

shows that VOC and NOx emission reductions are more than sufficient to meet the 

required ROP in all milestone years. 

Figure 6 shows the percentage reductions in creditable VOC and NOx along with the 

required percent reduction targets relative to 2007. The combined VOC and NOx 

percent reductions far exceed the required ROP percent change targets. 

Figure 6. Creditable Emissions Reductions Relative to ROP Targets

E. Contingency Measures

Contingency measures are commitments for extra measures to reduce emissions that

go into effect without further regulatory action. In an attainment plan, the measures

must be extra in the sense that the reductions are not accounted for in the ROP or in the 

attainment demonstration. ROP contingency reductions are used if the planned 

emissions controls fail to reach the emissions targets specified in the attainment plan for

ROP. The attainment year contingency reductions are required if a region fails to attain 

a federal standard by the attainment date and must be implemented automatically. 

The 2013 Plan meets the required ROP and attainment contingency requirements due 

to emission reductions from already adopted regulations and incentive programs. The 

District adopted Rule 9610 (State Implementation Plan Credit for Emission Reductions

Generated through Incentive Programs) to provide the District with a mechanism to 

10
claim credit for SIP-creditable incentive-based emission reductions achieved in the 

San Joaquin Valley. 

The ROP demonstration in the District 2013 Plan shows that the San Joaquin Valley

meets the ROP milestone year contingency requirement. The required three percent

contingency was secured by the first milestone year (2010) and carried through to the 

attainment year (2017). Also, based on reductions already available through adopted 

regulations, and 3.5 tpd of NOx emission reductions from incentive programs, the 2013 

Plan satisfies the attainment year contingency requirement. 

F. Clean Fuels and Clean Technologies for Boilers

The CAA directs extreme nonattainment areas to require each new, modified, or existing 

electric utility, industrial, or commercial boiler that emits more than 25 tons per year of

NOx to use natural gas, methanol, or ethanol (or comparably low polluting fuel) as its 

primary fuel; or use advanced control technology, such as catalytic control technology or

other comparably effective control methods, for reduction of NOx emissions.

District Rules 4306 and 4352 address NOx emissions limits for the boilers in this

category. These boilers generally use natural gas and therefore satisfy the first

requirement of this section in the CAA. Liquid-fuel fired boilers are also addressed by

these rules and the applicable NOx emission limits satisfy the second requirement of

this section in the CAA. Solid-fuel fired boilers are addressed by Rule 4352 and the 

applicable NOx emissions limit satisfies the second requirement as well. Therefore, the 

District currently complies with the CAA requirement for clean fuels and technologies for 

boilers.

G. VMT Offset Demonstration

The CAA requires areas classified as severe or extreme nonattainment of the ozone

standard to submit a vehicle miles traveled offset demonstration. The San Joaquin 

Valley Air Basin is currently designated as extreme and is therefore subject to this 

requirement. For areas classified as extreme, Section 182(d)(1)(A) of the CAA requires 

that SIPs include a demonstration that “identifies specific enforceable transportation

control strategies and transportation control measures to offset any growth in emissions 

from growth in such area....” 

The 2013 Plan includes a VMT offset demonstration for both the 1-hour and 8-hour 

ozone standards with analysis provided by ARB. This demonstration was prepared 

pursuant to the requirements of the CAA and is consistent with August 2012 U.S. EPA 

guidance entitled “Implementing Clean Air Act Section 182(d)(1)(A): Transportation 

Control Measures and Transportation Control Strategies to Offset Growth in Emissions 

Due to Growth in Vehicle Miles Traveled.” The 2013 Plan demonstrates that the VMT 

offset demonstration is satisfied for the San Joaquin Valley for both the 1-hour and 

8-hour ozone standards, and is described further in Appendix D of the District 2013 

Plan.

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IV. ENVIRONMENTAL IMPACTS

To meet the requirements of the California Environmental Quality Act (CEQA), the 

District prepared a Notice of Exemption because the Initial Study showed there is no 

substantial evidence, in light of the whole record, that the 2013 Plan may have a 

significant effect on the environment. The Final Notice of Exemption and approval of 

the 2013 Plan occurred at a public meeting held on September 19, 2013.

V. STAFF RECOMMENDATION

ARB staff recommends that the Board:

1. Approve the San Joaquin Valley 2013 Plan, including the emission inventory,

local control strategy, attainment demonstration, rate of progress 

demonstration, contingency measures, RACT/RACM demonstration, and VMT

offset demonstrations, as revisions to the California SIP.

2. Direct the Executive Officer to submit the San Joaquin Valley 2013 Plan to

U.S. EPA for approval.

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Appendix A

District Submittal Letter and

Governing Board Resolution

13
Appendix B

Link to District 2013 1-Hour Ozone Plan

http://www.valleyair.org/Air_Quality_Plans/Ozone_Plans.htm

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