State of California

AIR RESOURCES BOARD

STAFF REPORT

PROPOSED 2003 STATE IMPLEMENTATION PLAN

REVISIONS FOR THE SOUTH COAST AIR BASIN

 AND COACHELLA VALLEY 

Release Date: August 25, 2003

Meeting Date: September 24-25, 2003

The energy challenge facing California is real. Every Californian needs to take immediate action to

reduce energy consumption. For a list of simple ways you can reduce demand and cut your energy

costs, see our Website: http://www.arb.ca.gov.
State of California

California Environmental Protection Agency

AIR RESOURCES BOARD

STAFF REPORT

PUBLIC HEARING TO CONSIDER APPROVAL OF 

PROPOSED 2003 STATE IMPLEMENTATION PLAN REVISIONS FOR 

THE SOUTH COAST AIR BASIN AND COACHELLA VALLEY

Air Resources Board Hearing

Begins September 24, 2003 at 10:00 a.m. 

and may continue September 25, 2003 at 8:30 a.m.

South Coast Air Quality Management District Auditorium

21865 E. Copley Drive

Diamond Bar, California 91765

Hearing notice available at http://www.arb.ca.gov/planning/sip/scsip03/scsip03.htm

Prior to the hearing, the public may submit written comments through regular mail,

e-mail or fax. To be considered by the Board, written comments not physically

submitted at the hearing must be received no later than 12:00 noon,

September 23, 2003 and sent to:

Clerk of the Board

Air Resources Board

1001 I Street, 23rd Floor

Sacramento, California 95814

or by e-mail to: 2003sip@listserv.arb.ca.gov

or by facsimile transmission to the Clerk of the Board at (916) 322-3928

This report has been reviewed by the staff of the 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 mention of trade names or

commercial products constitute endorsement or recommendation for use. 
This report and related materials are available for downloading from the Air Resources

Board’s Internet site at http://www.arb.ca.gov/planning/sip/sip.htm. In addition, written

copies may be obtained from the Board’s Public Information Office, 1001 I Street, 1st

Floor, Environmental Services Center, Sacramento, California 95814, (916) 322-2990. 

If you are a person with a disability and desire to obtain this document in an alternative

format, please contact the Americans with Disabilities Act Coordinator at

(916) 323-4916, or TDD (916) 324-9531, or (800) 700-8326 for TDD calls from outside

the Sacramento area.

QUESTIONS 

Ms. Sylvia Oey, Manager

Liaison Section

Phone: (916) 322-8279

Email: soey@arb.ca.gov

Mr. Joe Calavita, Air Pollution Specialist

ARB Staff Liaison to the South Coast District

Phone: (916) 327-5783

Email: jcalavit@arb.ca.gov

ACKNOWLEDGEMENTS

ARB staff thanks the South Coast Air Quality Management District staff for the high

level of coordination between the agencies in developing the technical elements of this

plan and presenting the draft strategies to the public in joint workshops. We would like

to recognize Dr. Elaine Chang, Dr. Laki Tisopulos, Mr. Zorik Pirveysian, and

Mr. Joe Cassmassi, who each dedicated many hours to this interagency cooperation. 
Table of Contents

EXECUTIVE SUMMARY ............................................................ ES-1

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

A. Profile of the South Coast Air Basin ............................ 1

B. Historical Emissions and Air Quality............................. 1

1. Ozone ......................................................... 2

2. Particulate Matter ........................................... 3

3. Carbon Monoxide .......................................... 3

4. Nitrogen Dioxide ............................................ 3

II. AIR QUALITY PLANNING ................................................. 4

A. Federal Planning Requirements ................................. 4

1. Ozone ......................................................... 4

2. PM10 .......................................................... 5

B. 1994 Ozone SIP ..................................................... 5

C. 1997 Ozone, PM10, CO, and NO2 SIPs ...................... 5

D. 1999 Ozone SIP ..................................................... 6

E. 2002 PM10 SIPs ..................................................... 6

F. 2003 Ozone, PM10, CO, NO2 SIPs ............................ 7

III. 2003 OZONE SIP FOR SOUTH COAST AIR BASIN ............... 8

A. Emission Inventory .................................................. 8

 1. Mobile Sources .............................................. 9

a. On-Road ............................................. 9

b. Off-Road ............................................. 10

2. Stationary and Areawide Sources ...................... 10

B. Modeled Ozone Attainment Demonstration .................. 11

1. Air Quality Model ........................................... 12

2. Ozone Episode .............................................. 13

3. Peer Review ................................................. 14

4. Fallback Approach Based on U.S. EPA Action ..... 14

C. Control Strategy ...................................................... 15

1. Local Control Strategy .................................... 16

a. District Progress since 1997/1999 SIP ....... 16

b. Proposed District Measures ..................... 18

c. Structure of District Commitment .............. 25

d. Transportation Strategy ......................... 27

2. State Control Strategy ..................................... 28

a. Progress Since 1994 SIP ........................ 28

b. Proposed State Measures ....................... 30

c. Structure of Proposed State Commitment ... 32
3. Federal Responsibility ..................................... 33

a. Progress Since 1994 SIP ........................ 33

b. Emissions Contribution ........................... 34

c. New Federal Actions to Reduce Emissions 35

4. Long-Term Strategy ....................................... 35

a. Primary Attainment Strategy .................... 35

b. Alternative Attainment Strategy ................ 38

IV. 2003 PARTICULATE MATTER SIP FOR SOUTH COAST AIR

BASIN .............................................................................. 39

A. Emission Inventory .................................................. 39

1. Inventory Updates ........................................... 40

B. Attainment Demonstration ......................................... 42

C. Control Strategy ...................................................... 44

1. District Control Measures ................................. 44

2. Structure of District Commitment ....................... 48

V. 2003 CARBON MONOXIDE SIP FOR SOUTH COAST AIR

BASIN ........................................................................... 49

A. Emission Inventory .................................................. 49

B. Attainment Demonstration ......................................... 50

 C. Control Strategy ...................................................... 50

VI. 2003 NITROGEN DIOXIDE SIP FOR THE SOUTH COAST ..... 51

VII. 2003 PARTICULATE MATTER SIP FOR COACHELLA

VALLEY ......................................................................... 52

A. 2003 Coachella Valley PM10 Plan .............................. 52

1. Emission Inventory ......................................... 52

2. Attainment Demonstration ................................ 52

VIII. ON-ROAD MOTOR VEHICLE EMISSION BUDGETS ..............

54

IX. STAFF RECOMMENDATIONS ........................................... 59
ES-1

EXECUTIVE SUMMARY

The Air Resources Board (ARB or Board) will consider approval of a revised State

Implementation Plan (SIP) for the South Coast Air Basin at a public hearing on

September 24, 2003. This new air quality plan, adopted by the South Coast Air Quality

Management District (District), identifies new clean air strategies needed to bring the

region into attainment with federal air quality standards for ozone, particulate matter

(PM10), and carbon monoxide. As a separate item, the Board will also consider

approval of the proposed 2003 State and Federal Strategy that is an essential element

of the South Coast SIP. If the Board approves these two items both will be submitted to

the U.S. Environmental Protection Agency (U.S. EPA) for federal approval. ARB staff is

recommending Board approval of the South Coast SIP and the State and Federal

Strategy as a strengthening of the existing SIP needed to comply with federal Clean Air

Act requirements.

Solving the South Coast’s air quality problem, as evidenced by the severity of the 2003

ozone season, requires new actions by air quality agencies to ensure the region’s

historical clean air progress continues. The South Coast SIP reflects important new

near-term commitments by the District and ARB to achieve emission reductions from air

pollution sources under the respective air agency jurisdictions. The SIP also recognizes

that action by the federal government is essential to address national and international

sources that California can not practically or legally regulate.

In addition to establishing the near-term actions to be taken by each agency, the SIP

identifies the long-term emission reduction target for ozone that must be achieved by

2010. The long-term target represents 30 percent of the overall reductions needed.

The other 70 percent of the necessary reductions will be achieved through adopted

regulations and near-term measures to be adopted between 2003 and 2006. In the

proposed State and Federal Strategy, ARB staff has outlined a concurrent process for

identifying the long-term measures by 2007 as required by the Clean Air Act. These

measures will then be incorporated into the next SIP update. 

The South Coast SIP is based on updated air quality modeling that is used to establish

a 2010 emission target that demonstrates attainment of the federal one-hour ozone

standard. Like the other elements of the SIP, the air quality modeling has undergone

substantial public review as well as scientific peer review. Emission estimates have

been improved since adoption of the 1999 South Coast SIP, including substantial

revisions to the motor vehicle emission inventory. The updates to motor vehicle

emissions have triggered a federal requirement to update the “emissions budgets” for

purposes of federal transportation conformity requirements. New transportation

conformity budgets are included in the SIP and must be approved by U.S. EPA in early

2004 to keep transportation funds flowing. In addition, the South Coast SIP includes a

revised attainment demonstration for PM10 by 2006 and update to the attainment

demonstration for carbon monoxide. 
ES-2

The South Coast SIP represents significant progress on many fronts. The SIP:

• Includes near-term measures to achieve new emission reductions of 87 tons per day

(tpd) of volatile organic compounds (VOC) and 50 tpd oxides of nitrogen (NOx). 

• Provides an enforceable commitment to identify and implement long-term measures

needed to attain the federal one-hour ozone standard by 2010.

• Demonstrates attainment of the federal PM10 standard in the South Coast Air Basin

and Coachella Valley by the 2006 deadline. 

• Uses improved air quality modeling and emission estimates, and incorporates new

growth projections and adopted controls into planning baselines.

The ozone attainment demonstration in the SIP is summarized in Table ES-1. The table

indicates that existing controls will provide over 60 percent of the emissions reductions

needed for attainment in 2010. The SIP includes a District commitment and, if

approved by the Board, a State commitment for the adoption of additional near-term,

“defined” measures that will provide over 70 percent of the needed emission reductions,

when combined with already adopted controls. 

Table ES-1

Summary of Attainment Demonstration for 2003 Ozone SIP

(South Coast Air Basin, tons per day)

VOC NOx VOC + NOx

1997 Baseline Emissions 1222 1165 2381

2010 Attainment Emissions Target 310 530 840

Total Reductions Needed 912 635 1547

Reductions from Adopted Measures 560 404 964

Reductions from Near-Term Measures 87 50 137

Reductions from Long-Term Commitments 265 183 448

The SIP acknowledges that the adopted measures, together with the local and State

near-term measures, will not reduce emissions enough to result in attainment of the

federal one-hour ozone standard by 2010. Like prior SIPs for this Basin, the

2003 District Plan includes a commitment to achieve additional reductions from longterm measures to be identified by 2007. The federal Clean Air Act recognizes that

extreme ozone nonattainment areas, such as the South Coast, must rely on evolving

technologies to meet attainment goals. The South Coast SIP is consistent with this

provision of the Clean Air Act, section 182(e)(5). 
ES-3

The primary issues raised in the process of development and District adoption of the

SIP relate to the long-term measures – both the magnitude of the reductions needed

and how the responsibility for achieving these reductions is allocated. A key related

issue is the uncertainty about what actions the federal government will take to achieve

reductions from national and international sources. Sources requiring federal action

account for 33 percent of the NOx emissions remaining in 2010 after taking into account

existing requirements and the new near-term measures. 

In absolute terms, the magnitude of the reductions needed from long-term measures is

greater than in the 1999 South Coast SIP for two reasons. One, the 2010 emissions

target is tighter based on more stringent air quality modeling results. Second, our

improved understanding of motor vehicle emissions has led to increased emission

estimates, which translates into an increased emission reduction target. It’s important

to note that an increased emission estimate is not an increase in measured air quality.

However, this does trigger a recalibration of air quality modeling and the resulting

emission reduction target -- in this case, making the emission reduction target greater

than in the 1999 SIP. And, given the severity of the 2003 ozone season, it is clear that

substantial additional emission reductions will be needed in coming years in order to

attain the ozone standard in 2010. 

ARB staff believes that taking the additional time allowed by the Clean Air Act to

develop long-term measures is both necessary and appropriate. We are committed to

initiating that process in early 2004 concurrent with the ARB rulemaking efforts outlined

in the proposed State and Federal Strategy. We envision that process as a cooperative

multi-agency effort that should focus on identifying available and cost-effective longterm strategies. We don’t see a practical basis for allocating emission reduction

responsibilities to specific agencies until that process is complete – which should be as

soon as possible but no later than 2007. 

While the District plan includes an assignment of responsibility for long-term reductions

by agency, primarily to ARB, we view this as a placeholder between now and 2007

when long-term measures must be defined. However, as the State agency charged

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

the necessary measures are identified by 2007, and the emission reductions are

achieved by 2010. On that basis, we recommend approval of the SIP as proposed by

the District. 

In terms of the District measures, we propose approval of that plan element which

would achieve 22 tons per days of VOC reductions and 5 tons per day of NOx

reductions from new near-term measures and 31 tons per day from long-term

measures. Section III of this report discusses the District measures and identifies areas

where we think further assessment is warranted as we work with other agencies to

identify long-term emission reduction opportunities. 
ES-4

We also propose approval of the emission reduction commitment by the Southern

California Association of Governments (SCAG) – 16 tons per day of VOC and 8 tons

per day of NOx. This represents a carrying forward of SCAG’s commitment in the 1999

SIP but no additional reductions. Given the challenging long-term emission reduction

target for the region, we expect SCAG to actively participate in the process of

identifying the innovative long-term strategies that will be needed by 2010. 

The ARB’s proposed near-term measures would achieve an additional 49 tons per day

of VOC reductions and 37 tons per day of NOx reductions. This Board commitment is

being considered separately for approval as part of the 2003 State and Federal

Strategy. The Strategy also discusses measures that we believe U.S. EPA should

pursue in order to meet its obligation to reduce emissions from sources under its

jurisdiction, as well as to address international sources.

The District has proposed a new federal obligation of 18 tons per day of VOC reductions

and 68 tons per day of NOx reductions. However, given the lack of an explicit federal

commitment to achieve additional emission reductions, the District includes a proposal

to increase the long-term State emission reduction target correspondingly if the federal

government does not meet this obligation. As part of the State and Federal Strategy,

ARB staff is proposing that the Board allow the federal reductions to be added to the

overall State long-term commitment if needed, with no modifications to the control target

at this time. However, as the process of developing the long-term measures proceeds,

we will use every possible means to press our federal counterparts to act where the

State and local air agencies cannot.

The District also included in its SIP an option for an alternative, less stringent, NOx

emission target for 2010. ARB staff does not propose pursuing this option since

additional NOx reductions are needed to meet the State and federal PM2.5 standards.

If the Board approves the backstop to a federal commitment described above, this

option would not be triggered. Table ES-2 shows the SIP’s ozone attainment

demonstration by local, State, and federal jurisdiction.

In summary, ARB staff recommends Board approval of the South Coast’s 2003 State

Implementation Plan for submittal to U.S. EPA. The SIP meets Clean Air Act

requirements, includes new near-term State and local clean air measures, and

recognizes the urgent need to identify and implement the long-term measures needed

to attain the federal one-hour ozone standard by 2010. 
ES-5

Table ES-2

2010 Attainment Demonstration for the 2003 Ozone SIP by Jurisdiction

(South Coast Air Basin, tons per day)

VOC NOx

Percent of

Combined

VOC+NOx by

Jurisdiction

1997 Baseline Emissions

 State

 Local 

 Federal

 Total 

835

298

89

1222

758

128

279

1165

67%

18%

15%

Emission Reductions from Adopted Measures

 State

 Local 

 Federal

 Total 

-418

-105

-37

-560

-317

-43

-44

-404

76%

15%

 8%

2010 Baseline Emissions

 State

 Local

 Federal

 Total

417

193

52

662

441

85

235

761

60%

20%

20%

Emission Reductions from New Near-Term Measures

 State 

 District

 Southern California Association of Governments 

 Federal

 Total

-49

-22

-16

0

-87

-37

-5

-8

0

-50

63%

20%

17%

0

Emission Reductions from New Long-Term Measures

 Proposed State Commitment for Multi-Agency Effort

 Local Commitment

 Federal Obligation

 Total

-216*

-31

-18

-265

-113*

0

-68

-181

74%

 7%

19%

2010 Attainment Emissions Target 310 530

*The SIP proposes to increase this commitment to 234 TPD VOC and 181 TPD NOx reductions

if U.S. EPA does not carry out its legal responsibilities to achieve new emission reductions. 
1

I. BACKGROUND

A. Profile of the South Coast Air Basin

The South Coast Air Basin (South Coast or Basin) includes the southern two-thirds of

Los Angeles County, all of Orange County, and the western, more urbanized portions of

Riverside and San Bernardino Counties. The area generally forms a lowland plain,

bounded by the Pacific Ocean on the west and by mountains on the other three sides.

The South Coast is California's largest metropolitan region. With a population of over

15 million, it is home to about forty percent of the State’s residents. 

The South Coast Air Quality Management District (District) is the local air quality agency

responsible for the Basin. The District also has jurisdiction over the Riverside County

portion of the Salton Sea Air Basin (Coachella Valley) and the western portion of the

Mojave Desert Air Basin in Riverside County. The Southern California Association of

Governments (SCAG) is the transportation planning agency for the region. Figure I-1

shows the boundaries of the District, the Basin, and Coachella Valley. 

Figure I-1

South Coast Air Quality Management District Boundaries

B. Historical Emissions and Air Quality

Despite rapid increases in population and vehicle miles traveled (VMT), air pollution

controls in the Basin have reduced emissions of volatile organic compounds (VOC)1

and nitrogen oxides (NOx) -- the pollutants that form ozone in the presence of sunlight --

 

1 ARB generally classifies reactive hydrocarbons as reactive organic gases (ROG). The State’s legal

commitments for emission reductions are expressed in terms of ROG. But this report uses the

classification of volatile organic compounds (VOC), a subset of ROG, for consistency with the District’s

terminology in the 2003 Plan. VOC and ROG are functionally equivalent for the purposes of this report.
2

by about 45 percent from 1990 to 2003. Direct emissions of particulate matter less than

or equal to ten microns in diameter (PM10) have declined by about 15 percent in the

same period, and carbon monoxide emissions have fallen by over 55 percent. 

The emission decreases have significantly improved ozone air quality in the Basin.

Since the 1980s, the number of days exceeding the federal one-hour standard has

decreased over 70 percent, and the maximum ozone concentration has decreased over

50 percent. Population exposure to unhealthy air has declined by 80 percent during this

same time period. 

1. Ozone

The long-term improvement in South Coast ozone air quality, as measured by the

maximum one-hour ozone concentration in parts per billion (ppb) and the number of

days over the federal one-hour ozone standard, is shown in Figure 1-2. 

Figure I-2

Maximum One-Hour Ozone Concentration and 

Days Over Federal One-Hour Ozone Standard in South Coast Air Basin

(through August 20, 2003)

However, the last few years do not appear to show the same improvements as seen in

the early 1990s, despite continued emission reductions. The Summer of 2003 has been

particularly conducive to ozone formation. By the end of July 2003, the South Coast Air

Basin had experience 44 exceedances of the federal one-hour standard, more than

were recorded during each of the prior three years. Furthermore, on July 11, 2003, the

South Coast experienced its first Stage 1 ozone alert since 1998. A Stage 1 alert is

called when ozone concentrations reach or exceed 200 ppb. The alert warns even

healthy residents to curtail their outdoor activities. 

0

100

200

300

400

500

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

Maximum One-Hour Ozone Concentration (ppb)

Days Over Federal One Hour Ozone Standard
3

The variation in ozone air quality is strongly influenced by differences in weather

conditions. Years having more days with severe weather conditions that are conducive

to ozone formation have a greater chance of having more days that exceed the

standards and higher peak concentrations. These severe weather conditions include

hot temperatures, strong inversion layers, and calm conditions.

Our meteorologists have reviewed meteorological data from 1980 through July 2003.

Their analysis indicates that the total number of days with high ozone forming potential

during 2003 were greater for a comparable period of the year (May 1 through July 21)

than any other year during the analyzed time period (1980- 2003). This may help

explain the large number of exceedance days in 2003 relative to the past few years.

Furthermore, the weather conditions present during the July 11, 2003 episode had not

been seen since a similar episode in 1998. It is interesting to note that the 1998

episode had higher peak concentrations than the 2003 episode and was more

widespread throughout the Basin than the 2003 episode. Emission reductions

achieved since 1998 have resulted in lower ozone levels on days with severe weather

conditions. However, this year’s peak values are a clear indication that substantial

further emission reductions are needed. 

The Basin also exceeds U.S. EPA’s new eight-hour ozone standard. 

2. Particulate Matter 

Annual average concentrations of PM10 have declined by over a third in the Basin since

the 1980s. However, the Basin continues to exceed the federal 24-hour and annual

average PM10 standards of 150 μg/m3 and 50 μg/m3, respectively. In 2002, the

maximum 24-hour PM10 concentration was 130 μg/m3, while the annual average PM10

concentration was 60.2 μg/m3.

The Basin also exceeds U.S. EPA’s new fine particulate (PM2.5) 24-hour and annual

standards. 

3. Carbon Monoxide 

Peak eight-hour carbon monoxide (CO) levels in the South Coast Basin have declined

by over fifty percent since the early 1980s, due largely to cleaner motor vehicles and

fuels. Because the South Coast exceeded the federal carbon monoxide standard only

once during 2001 and 2002, it now meets the criteria for attainment. The District has

chosen to update the CO attainment demonstration now and accumulate a third year of

air quality meeting the standard before preparing a maintenance plan and seeking an

official redesignation to attainment.

4. Nitrogen Dioxide

The Basin has attained the federal nitrogen dioxide (NO2) standard since 1991.
4

II. AIR QUALITY PLANNING

This chapter briefly reviews the relevant planning provisions in the federal Clean Air Act

(CAA or Act) and describes recent South Coast plans. 

A. Federal Planning Requirements

The CAA establishes planning requirements for those areas that routinely exceed the

health-based National Ambient Air Quality Standards (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 Health and Safety Code (HSC) section 39602 designates the ARB as the

State's air pollution control agency for all purposes set forth in federal law, including the

preparation of the SIP. The HSC further specifies that the ARB must adopt the

nonattainment area plan approved by a local district, unless the ARB finds, after a

public hearing, that the locally adopted plan will not meet the requirements of the CAA

(HSC Section 41650(a)). All California SIP revisions must be submitted to U.S. EPA by

ARB. The provisions and commitments in a U.S. EPA-approved SIP are federally

enforceable. The CAA also allows interested parties to sue U.S. EPA, the state, or local

agencies to compel implementation of an approved SIP and other provisions of the Act.

The South Coast District customarily prepares a comprehensive plan, approximately

every three years, to address both federal and State air quality planning requirements

and multiple air pollutants. The District’s Air Quality Management Plan (AQMP)

includes elements that are beyond the scope of the federal requirements. Thus, SIP

revisions for this region are typically based on a subset of the AQMP -- the technical

foundation (monitoring data, emissions, modeling) and the local control strategy that

addresses progress, attainment, or maintenance of a federal air quality standard. Once

approved by ARB, the SIP revision sent to U.S. EPA includes only the elements needed

to meet federal requirements, as directed by State law. 

1. Ozone

The CAA requires the South Coast Air Basin, as an "extreme" ozone nonattainment

area, to provide for attainment of the federal one-hour ozone standard by

November 15, 2010. Coachella Valley is part of the Southeast Desert Modified Air

Quality Management Area, a “severe-17” federal one-hour ozone nonattainment area

with an attainment date of November 15, 2007. 

Section 182(c)(2) of the Act requires that the SIP establish ozone rate-of-progress

milestones for VOC and NOx and demonstrate how the control strategy meets those

interim year targets. In addition, the Act requires the establishment of conformity

emission budgets for specific sources like on-road motor vehicles for milestone years.

These budgets are used to determine if planned projects that will require federal
5

approval or funding, such as freeway improvements or airport expansions, are

consistent with the emissions targets in the approved SIP. Other Act requirements

include transportation control measures to address growth in vehicle travel, and

contingency measures to be triggered if progress milestones are not achieved. 

2. PM10 

As "serious" PM10 nonattainment areas, the South Coast Air Basin and Coachella

Valley were required by the CAA to attain the federal PM10 standard by December

2001. These areas did not attain the standard by the deadline. U.S. EPA granted each

area a five-year extension to December 2006, as allowed by the Act. The Act also

requires that "serious" PM10 nonattainment areas adopt Best Available Control

Measures (BACM) for fugitive dust sources, and that PM10 plans include motor vehicle

emission budgets, reasonable further progress milestones, and contingency measures.

B. 1994 Ozone SIP

In November 1994, California submitted comprehensive ozone SIP for the South Coast

and five other nonattainment areas in California. The control strategy in the 1994 SIP

included local commitments to adopt rules and transportation control measures, as well

as a statewide element to reduce emissions from mobile sources, fuels, consumer

products, and pesticides. In addition to its own commitments, ARB identified emission

reduction strategies for sources under federal authority and credited the expected

benefits in the attainment demonstration. In the Federal Register notice approving the

1994 SIP, U.S. EPA argued that the State did not have the authority to assign

reductions to the federal government.1 U.S. EPA instead participated in a public

consultative process to identify potential strategies to reduce emissions from sources

subject to federal authority. 

The District’s 1994 AQMP was the basis for the local element of the 1994 Ozone SIP for

the South Coast Air Basin and Coachella Valley.

C. 1997 Ozone, PM10, CO, and NO2 SIPs 

In 1996, the District developed and adopted the 1997 AQMP, which included:

 An ozone attainment plan for the South Coast Air Basin and Coachella Valley

 A PM10 attainment plan, and attainment date extension request for the South Coast

Air Basin from 2001 to 2006

 A carbon monoxide attainment plan for the South Coast Air Basin

 A nitrogen dioxide maintenance plan and redesignation request for the South Coast

Air Basin

ARB approved all of these elements and submitted them to U.S. EPA as SIP revisions. 

 

1 Federal Register, January 8, 1997 (Volume 62, Number 5); Approval and Promulgation of

Implementation Plans; California - Ozone; Final Rules.
6

The 1997 Ozone SIP modified the local element of the 1994 Ozone SIP attainment

strategy. The plan used new growth projections, emission inventories, and modeling

analyses to demonstrate that the ozone standard could be attained in 2010 with fewer

emission reductions. As a result, the District deleted or delayed several of the local

ozone control measures in the 1994 SIP. ARB did not change the State and federal

strategy from the 1994 SIP, but the resulting emission reductions were updated based

on the new inventory. U.S. EPA subsequently proposed a partial disapproval of the

proposed 1997 Ozone SIP revision, due to the delay or deletion of local control

measures and the federal emission reduction assignment.1 U.S. EPA approved the

carbon monoxide and nitrogen dioxide elements of the 1997 AQMP in 1998, 2 3 but did

not act on the 1997 PM10 SIP for the South Coast Air Basin at that time. 

 

D. 1999 Ozone SIP

In September 1997, three environmental groups filed a citizens’ suit to compel

implementation of the federally approved 1994 Ozone SIP. As part of a settlement

agreement between the District and the plaintiffs, the District amended the 1997 AQMP

in 1999 to accelerate implementation of some of the stationary short-term control

measures. The District submitted the 1999 SIP revision to ARB; ARB approved it and

submitted it to U.S. EPA. In 2000, U.S. EPA approved the 1997 SIP as amended in

1999 (1997/1999 SIP) as a revision to the 1994 Ozone SIP.4

E. 2002 PM10 SIPs

The South Coast Air Basin and Coachella Valley both failed to meet the federal PM10

attainment deadline of 2001. In June 2002, the District updated the emission budgets

and control measure implementation status for the South Coast Air Basin’s 1997 PM10

SIP to facilitate federal approval of the plan and attainment date extension request.

That same month, the District also adopted the 2002 Coachella Valley PM10 Plan, and

requested a five-year PM10 attainment date extension for the Coachella Valley. The

District also committed to update the PM10 plans for the Basin and Coachella Valley in

2003 utilizing the latest approved motor vehicle emissions model and planning

assumptions. ARB approved these revisions and submitted them to U.S. EPA. In April

2003, U.S. EPA approved the 1997 PM10 Plan, 2002 Coachella Valley PM10 Plan, and

attainment date extension requests for both areas.5

 

1 Federal Register; January 12, 1999 (Volume 64, Number 7); Approval and Promulgation of State

Implementation Plans -- South Coast.

2 Federal Register; April 21, 1998 (Volume 63, Number 76); Approval and Promulgation of State

Implementation Plans -- South Coast Air Quality Management District. 3 Federal Register; July 24, 1998 (Volume 63, Number 124); Approval and Promulgation of State

Implementation Plans and Redesignation of the South Coast Air Basin in California to Attainment for

Nitrogen Dioxide.

4 Federal Register; April 10, 2000 (Volume 65, Number 69); Approval and Promulgation of State

Implementation Plans -- South Coast.

5 Federal Register; April 18, 2003 (Volume 68, Number 75); Approval and Promulgation of State

Implementation Plans -- South Coast.
7

F. 2003 Ozone, PM10, CO, NO2 SIPs 

On August 1, 2003, the District Governing Board adopted its 2003 AQMP that included

elements intended to revise the South Coast Air Basin SIPs for ozone, PM10, CO, and

NO2, as well the Coachella Valley SIPs for ozone and PM10. The District submitted all

of these plans to ARB with a request for approval and forwarding to U.S. EPA as SIP

revisions. We are proposing that the Board consider approval of each element,

collectively referred to as the 2003 Plan in this document, with the exception of the

Coachella Valley Ozone SIP revision. 

Just prior to publication of this report, we found that the Coachella ozone plan does not

contain the required motor vehicle emission budgets for transportation conformity.

Without the updated budgets, the Coachella ozone plan is incomplete and we could not

recommend Board approval. We expect that the District will adopt and transmit the

needed budgets to ARB for subsequent submittal to U.S. EPA. 

Because Coachella Valley is one of three subregions in the Southeast Desert ozone

nonattainment area, the other subregions (Antelope Valley and Mojave Desert) must

also adopt and submit a revised attainment demonstration, including vehicle emissions

budgets, before we can provide U.S. EPA with a complete package for the

nonattainment area. These other areas are working on SIP revisions for local adoption

in early 2004. As long as ARB receives adopted ozone budgets for Coachella Valley by

then, we do not expect this issue to delay U.S. EPA action on the comprehensive

Southeast Desert budgets or SCAG’s ability to make conformity findings for the

upcoming 2004 Regional Transportation Plan. 
8

III. 2003 OZONE SIP FOR SOUTH COAST AIR BASIN

To demonstrate attainment of the one-hour ozone standard, the 2003 Plan relies on

new emission reductions to be achieved at the local, State, and federal level. ARB staff

provided the draft State and federal strategy to the District so the public could see all

the elements of the control strategy in one place. As a separate item, the Board will

consider approval of the proposed 2003 State and Federal Strategy that is an essential

element of the South Coast Ozone SIP.

The District submitted the 2003 Plan to ARB for its consideration on August 7, 2003. If

ARB approves both the State and local elements, the overall plan can be submitted to

U.S. EPA as a SIP revision. If approved by U.S. EPA, the 2003 Ozone SIP would

replace the existing 1997/1999 Ozone SIP, and the State commitments that were

originally made as part of the 1994 Ozone SIP. This chapter provides staff's evaluation

of the 2003 Ozone SIP emission inventory, attainment demonstration, and control

strategy for the Basin.

A. Emission Inventory

Emission inventories are fundamental elements of any air quality plan. They combine

data about existing emissions with growth forecasts and the impact of adopted

regulations to project emission levels in future years. The 2003 Plan utilizes the latest

emission estimates for stationary, area-wide, and on- and off-road mobile sources. This

updated inventory reflects improved methodologies for estimating emissions, recently

adopted controls, the latest growth projections, previously uninventoried sources, and

other improvements.

VOC and NOx emissions are projected to decline by about 40 percent between the

2003 Plan’s 1997 base year, and the and the 2010 ozone attainment year, as a result of

controls that have already been adopted. This reflects a 30 percent decline in

emissions from stationary and area-wide sources, a 49 percent decline in emissions

from on-road motor vehicles, and a 32 percent decline in emissions from off-road

vehicles and equipment. Tables III-1 shows the breakdown of VOC and NOx emissions

by broad source category in 1997 and 2010, with the benefit of adopted controls. 

The rapid decline in on-road motor vehicles emissions is due to regulations to reduce

emissions from new cars and trucks and fuels. By 2010, new cars will be 99 percent

controlled, while new trucks will be at 98 percent control. Pre-1998 passenger cars will

account for just 23 percent of vehicle miles traveled by cars in the South Coast in 2010,

but will contribute 82 percent and 67 percent of the passenger car VOC and NOx,

respectively. 
9

Table III-1

2003 Plan Baseline Emissions Trends

(South Coast Air Basin Summer inventory in tons per day)

VOC NOx VOC + NOx

Source Category 1997 2010 1997 2010 1997 2010 % Change

Stationary & 

Area-wide

443 315* 128 85** 571 400 -30%

On-Road Motor

Vehicles 506 208 717 411 1223 619 -49%

Off-Road

Vehicles/Equipment 273 139 320 265 593 404 -32%

TOTAL 1222 662 1165 761 2387 1423 -40

* Includes 5.0 tpd VOC added to the stationary source baseline emission inventory -- 3.0 tpd for

future technology assessments, and 2.0 tpd for the phase-out of toxics and ozone depleting

compounds. Future technology assessments to occur prior to implementation of adopted District

rules may scale back emission reductions achieved by 2010. The phase-out of toxics and ozone

depleting compounds may result in increased VOC emissions from substitute products. 

** Includes 3.0 tpd NOx added to stationary source baseline emission inventory -- 2.0 tpd for

technology assessments and 1.0 tpd for the District "growth set-aside". See section entitled "Growth

Set Aside" (below) for more information.

The following sections discuss updates to the mobile, stationary and area-wide source

inventories since the 1997/1999 SIP, and provide ARB staff's analysis of the VOC and

NOx 2003 Plan inventory.

1. Mobile Sources

The mobile source emission inventories used in the 2003 Plan represent many

improvements in the models that are used to estimate emissions from both on-road and

off-road sources. As a result, our estimates of the emissions generated by mobile

sources have increased significantly relative to those used in the 1997/1999 SIP. These

higher estimates do not indicate that emissions are increasing over time – on the

contrary, actual emissions from cars and trucks have declined and will continue to

decline rapidly over time. This progress comes in response to State and federal

requirements for cleaner engines and fuels, and despite significant growth in population

and vehicle usage. 

a. On-Road

California's new on-road motor vehicle emission factor model (EMFAC2002) has been

used to generate the on-road mobile source emission inventory for the 2003 Plan.

EMFAC2002 represents a comprehensive review and revision of the on-road inventory

when compared to EMFAC7G, which was used in the 1997/1999 SIP. The major

changes reflected in EMFAC2002 include:
10

 New passenger vehicle and truck standards

 Updated light-duty vehicle emission estimates based on additional vehicle testing

 County-specific light-duty fleet information

 Updated light-duty fleet age distribution derived from new Department of Motor

Vehicle data

 Improvement of evaporative emission estimates for light-duty vehicles

 Updated estimates of Smog Check benefits

 Heavy-duty truck emissions from new cycle-based chassis dynamometer testing

 Heavy-duty truck "off-cycle" emissions due to emission control defeat devices

 New estimates of truck idling emissions

The 1997/1999 SIP utilized EMFAC to calculate the benefits of mobile source controls,

and CalTrans' Demand Travel Impact Model (DTIM) to generate the mobile source

planning and modeling inventories, and mobile source emission budgets. The 2003

Plan utilizes EMFAC2002 as the primary tool for all of these purposes. Because the

EMFAC model does not spatially distribute emissions below the county level, DTIM is

used in the 2003 Plan to allocate each county's EMFAC-based inventory into grid cells

for air quality modeling. This new approach to mobile source emissions will provide

greater consistency among the inventories used for planning, modeling, control

measure quantification, rate-of-progress determinations, vehicle emission budgets, and

transportation conformity analyses. ARB staff appreciates the cooperation of the

District and SCAG in making this transition.

b. Off-Road

The 2003 Plan is also the first South Coast plan to use ARB's OFFROAD model to

generate off-road mobile source emissions. The OFFROAD model represents a step

forward from the inventory methodologies used in the 1997/1999 SIP. The OFFROAD

model utilizes improved estimates of equipment population, usage, emission rates,

deterioration rates, and other information to provide seasonal and annual emissions for

most categories of off-road mobile sources. The OFFROAD model has also been

updated to include evaporative emission estimates for the first time. Emissions from

ships, aircraft, trains, and recreational vehicles are still estimated outside this model.

2. Stationary and Areawide Sources

Stationary and area-wide sources include industrial sources like factories, refineries,

power plants, and smelters; commercial sources like gas stations, dry cleaners, and

paint spray booth operations; and residential sources like fireplaces, water heaters and

house paints. Responsibility for reducing emissions from these sources rests with the

District, except for consumer products and aerosol paints (under ARB jurisdiction), and

gas stations (responsibility shared by ARB and District).

Growth Projections The growth assumptions used to estimate future emissions are a

critical element in any attainment demonstration plan -- they directly impact the amount

of emission reductions needed to reach the emissions target. 
11

State law requires the District to utilize population growth and economic projections

developed by SCAG in its plans and emission projections. Emission projections for

stationary and area-wide sources in the 2003 Plan are based on source-specific "growth

factors" from the SCAG Growth Forecast. The SCAG growth factors are generally a

function of growth in each sector's output, as determined by employment and

productivity forecasts. A "control factor" is applied to the grown emissions to account

for the application of adopted emission controls. 

ARB staff used an ARB-contracted report prepared by E.H. Pechan & Associates1

(Pechan) to provide an independent check on the SCAG growth projections that

underlie the 2003 Plan. The Pechan report includes comprehensive growth data for

stationary and area-wide sources, based on regression analysis and other analytical

assessments. This independent data was used to generate a 2010 emission inventory

for comparison to the inventory in the 2003 Plan. While there was some variation in

emissions for specific source categories, the overall 2010 projections differed by only

one percent for ROG and less than five percent for NOx.2

Growth Set-Aside The District's New Source Review (NSR) program requires that all

emission increases from new or modified large stationary sources be fully offset, and

that these sources install the Best Available Control Technology (BACT). The 2003

Plan establishes a "growth set-aside" of 1 tpd NOx, SOx, CO and PM10 in the 2010

baseline inventory to address a projected shortage in the stationary source emission

offsets needed to accommodate economic growth. The overall control strategy must

compensate by reducing each of these pollutants by an extra ton per day. Since these

emissions were accounted for in the attainment demonstration, ARB concurs that they

are available for use in the District's NSR program. 

B. Modeled Ozone Attainment Demonstration 

The Act requires the use of air quality modeling to assess whether the control strategy

in a proposed SIP, and the resulting emission reductions, will lead to attainment of the

ozone standard. The attainment demonstration determines the optimal "carrying

capacity" or attainment emissions target -- the combination of VOC and NOx emission

levels that the Basin can accommodate while attaining the standard. 

ARB and South Coast staff have worked together closely on the ozone modeling for this

Plan, including development of the modeling inventory and other inputs, analysis of

model performance, and validation of the ozone attainment demonstration. Attainment

of the ozone standard was demonstrated through an iterative process. First, emissions

and meteorological inputs for the August 5-6, 1997 episode were fed into the model,

 

1 E. H. Pechan & Associates, Development of Emission Growth Surrogates and Activity Projections Used

in Forecasting Point and Area Source Emissions, Final Report, February 26, 2001.

2 NOx sources in the District's Regional Clean Air Incentives Program (RECLAIM) were not included in

this analysis.
12

and the model's ability to replicate observed ozone concentrations was analyzed. The

model was then run using a "baseline" 2010 inventory to generate isopleth (or contour)

lines delineating the combinations of across-the-board VOC and NOx reductions that

are predicted to result in attainment. Finally, emission reductions from the specific

sources and commitments proposed in the Plan were incorporated into the modeling to

demonstrate attainment. The 2003 Plan also addresses transport of ozone and ozone

precursors from the Basin to Coachella Valley, Mojave Desert, and Antelope Valley, and

demonstrates that these downwind areas attain the federal one-hour ozone standard by

their 2007 deadline.

The 2003 Plan utilizes the Urban Airshed Model (UAM) used in the 1994 and 1997/1999

SIPs with a new August 5-6, 1997 ozone episode to demonstrate attainment in both the

Basin and the downwind areas. An August 27-28, 1987 episode, evaluated in the 1994

and 1997/1999 SIPs, was also assessed to provide a link to previous modeling

evaluations. Table III-2 provides a comparison of the 2003 Plan carrying capacity and

other modeling parameters with those of previous South Coast SIPs.

Table III-2

Modeling Results for Recent South Coast Ozone SIPs

Attainment

Emissions

Target

(tpd)

Plan Primary Episode 

3-Year

Design

Value*

(ppb)

Peak

Concentration

Observed in

Episode

(ppb)

Peak

Concentration

Predicted by

Model**

(ppb) VOC NOx

1994 SIP June 5-7, 1985 360 360 223 323 553

1997/1999 SIP June 23-25, 1987 350 240 211 413 530

2003 Plan August 5-6, 1997 215 187 199 310 530

* The design value reflects the fourth highest observed ozone level in an area over the three year period up to

and including the year of the primary episode day. A design value of 124 ppb or less equals attainment.

* The peak observed and predicted concentrations do not necessarily occur at the same location. 

1. Air Quality Model

ARB staff concurs with the use of the UAM as the primary air quality model for the

attainment demonstration. ARB and District staff conducted extensive model

performance evaluations with three air quality models -- the UAM, the California

Photochemical Grid Model (CALGRID), and the Comprehensive Air Quality Model with

Extensions (CAMx). While each of these models met U.S. EPA model performance

guidelines to varying degrees on different episode days, UAM was best able to simulate

the unpaired peak concentration during the August 5, 1997 episode. The District also

conducted a "mid-course evaluation" of UAM performance, validating the ability of the

model to replicate peak ozone concentrations observed during the Summer of 2002. 
13

While CALGRID and CAMx are considered the more state-of-the-art models, CALGRID

tended to underestimate peak ozone concentrations in the Basin. However, when the

CALGRID modeling results for August 5, 1997 are adjusted to reflect model

underprediction, CALGRID and UAM produce similar carrying capacity estimates.

CAMx was not utilized in the attainment demonstration as model performance in the

Basin was inferior to that of both UAM and CALGRID. However, CAMx continues to be

a robust model that has performed well in Northern California simulations. ARB staff

will continue working with both CAMx and CALGRID with the expectation that these

may be used in future South Coast plans. 

2. Ozone Episode

ARB staff also concurs with selection of August 5-6, 1997 as the primary ozone episode

to define the ozone attainment targets. This episode allowed for the use of detailed

meteorological, air quality, and emissions data collected during the 1997 Southern

California Ozone Study (SCOS97). SCOS97 was an intensive field study co-sponsored

by ARB, U.S. EPA, the U.S. Navy, South Coast District, and other air districts to better

understand how ozone is formed in Southern California, and to support the

development of effective strategies to reduce ozone. With the help of this detailed data,

the August 1997 episode provides for the best overall air quality model performance, as

judged by its ability to simulate the peak ozone concentration and other parameters. 

Three other ozone episodes were considered but not selected for the attainment

demonstration in the 2003 Plan. 

 A July 14-18, 1998 ozone episode was excluded from the attainment demonstration,

as it represents severe and infrequent meteorological conditions. ARB staff's

analysis indicates this level of ozone-forming potential occurs once every four to five

years. Because attainment of the federal ozone standard is based upon the fourth

highest ozone level over a three-year period, the federal standard does not require

modeling for attainment during the most severe meteorological events. The peak

measured one-hour ozone concentration of 244 ppb on July 14-18, 1998 also

exceeds the area's design value for that year. ARB and District staff agree that this

episode is not appropriate for use in the attainment demonstration.

 A September 28-29, 1997 weekend episode was also evaluated, but did not meet

U.S. EPA model performance criteria and was therefore also excluded. ARB staff

will continue working to better understand weekend emissions and ozone formation,

with the goal that a weekend episode can be used in a future South Coast SIP.

 

 Finally, an August 27-28, 1987 episode -- also included in the existing 1997/1999

SIP -- was retained as part of the 2003 Plan modeling analysis to supplement the

1997 episode and provide a link to the previous SIP. 
14

3. Peer Review

The South Coast District retained seven technical experts to help determine which air

quality model and episode day provide the most technically sound foundation for the

Plan.1

 Overall, the peer reviewers concurred that the technical approach for the air

quality modeling used by District and ARB staff was reasonable. The reviewers

generally supported use of August 5-6, 1997 as the primary modeling episode, as long

as model under-prediction of peak ozone concentrations (which occurs with use of the

CALGRID and CAMx models) is addressed. The reviewers were divided as to whether

UAM or CALGRID would provide the most sound attainment demonstration. While they

generally acknowledged CAMx to be a state-of-the-art air quality model, none of the

peer reviewers recommended its use for this Plan. 

4. Fallback Approach Based on U.S. EPA Action

The 2003 Plan includes an "Option 1" carrying capacity of 310 tpd VOC and 530 tpd

NOx, and an "Option 2" carrying capacity of 310 tpd VOC and 598 tpd NOx. The

530 tpd NOx emissions target in Option 1 was selected to ensure no backsliding from

the 1997/1999 SIP NOx target, and to ensure steady progress towards PM2.5

standards that will require additional NOx control. Option 2 includes 68 tpd of NOx

reductions that, under Option 1, would be achieved from sources under federal control.

U.S.EPA has indicated that it will not accept a plan that assigns emission reductions to

federal sources. Because the model response is insensitive to NOx reductions in the

range between 598 tpd and 530 tpd, both the Option 1 and Option 2 emission targets

demonstrate attainment in combination with 310 tpd VOC emissions. Table III-3 shows

the maximum projected concentration in 2010 for each of the modeled episode days,

using both Option 1 and Option 2 NOx emission levels.

Table III-3

Attainment Demonstration Options for 2003 Ozone SIP

(South Coast Air Basin, 2010)

UAM Predictions of Maximum Ozone Levels in ppb

Episode Day With Baseline

Emissions 

With Controlled

Emissions-Option 1

Federal Reductions

With Controlled

Emissions-Option 2

No Federal Reductions

August 5, 1997 153 123 123

August 6, 1997 146 120 124

August 27,1987 120 98 98

August 28, 1987 136 111 112

 

1 Peer reviewers were: Dr. C.S. Burton (retired); Dr. Judith Chow, Desert Research Institute; Dr. Robert

Harley, University of California at Berkeley; Mr. Frederick Lurmann (Sonoma Technology, Inc.); Dr. Edwin

Meyer (retired); Dr. John Seinfeld, California Institute of Technology; and Dr. Mel Zeldin (retired).
15

C. Control Strategy

If approved, the 2003 Plan will commit the District, SCAG, ARB, and BAR to achieve an

additional 87 tpd VOC and 50 tpd NOx reductions from new near-term control measures

for State and local implementation. These new measures represent the next iteration of

controls needed to attain the federal one-hour ozone standard in 2010, and continue

progress towards the more health-protective State standards and new federal

standards. Due to concerns expressed by U.S. EPA, no near-term federal control

measures are included in the 2003 Plan.

The 2003 Plan also benefits from nearly 1,000 tpd of combined VOC and NOx emission

reductions that will be realized between 1997 and 2010 as a result of controls that are

already on the books. Adopted controls and proposed new measures together account

for over 70 percent of the emission reductions needed to attain the federal one-hour

ozone standard over the course of this plan. As allowed by CAA Section 182(e)(5), the

2003 Plan also relies on long-term new technology measures, to be identified by 2007,

to achieve the remaining 30 percent of needed reductions. 

Upon approval by ARB and U.S. EPA, the State and local VOC and NOx emission

reduction commitment in the 2003 Plan would replace the control strategy in the

1997/1999 SIP. This section includes ARB staff's evaluation of the control elements,

including clarifications to the State and federal strategy, and suggestions for District

evaluation that may help achieve additional benefits to meet the region’s long-term

emission reduction needs. 
16

Table III-4

Control Strategy for 2003 Ozone SIP

(South Coast Air Basin, Summer Planning, tons per day)

VOC NOx

Emissions

1997 baseline emissions 1222 1165

2010 attainment emissions target 310 530

Reductions

Total emission reductions needed for attainment 912 635

Emission reductions from adopted measures 560 404

Percent of needed reductions from adopted measures 61% 64%

Emission reductions from near-term defined measures

 State 

 District

 SCAG

 TOTAL

49

22

16

87

37

5

8

50

Total emission reductions from adopted and near-term measures 647 454

Percent of needed reductions from adopted/near-term measures 71% 71%

Reductions from long-term measures

 District commitment

 Federal responsibility

 Proposed State overall commitment for multi-agency effort

 TOTAL

31

18

216

265

0

68

113

181

1. Local Control Strategy

The District is primarily responsible for controlling emissions from stationary and areawide sources (with the exception of consumer products). The District can also require

cleaner local vehicle fleets, but not set engine standards. In coordination with local

agencies, SCAG is responsible for designing the region’s transportation system,

including measures to reduce motor vehicle activity and emissions. The District, the

Mobile Source Air Pollution Reduction Review Committee, and SCAG also control

extensive public funding to mitigate the air quality impact of vehicle emissions. 

a. District Progress since 1997/1999 SIP

The District adopted measures to achieve about seventy percent of its commitments

from the 1997/1999 SIP. In the 1997/1999 SIP, the District committed to achieve 48.1

tpd VOC reductions from short- and intermediate term measures and 28 tpd VOC

reductions from long-term measures. Between October 1999 and October 2002, the

District adopted measures achieving 50 tpd VOC reductions by 2010, and has a

remaining long-term SIP commitment of 26.1 tpd VOC. The District met its 7.6 tpd NOx

commitment by adopting measures to achieve 7.8 tpd NOx reductions. Table III-5

shows the District's 1997/1999 SIP measure commitments and reductions achieved.
17

Table III-5

District Progress on 1997/1999 Ozone SIP Commitments

(As of October 2002, based on 1997/1999 SIP inventory, Summer planning, tons per day in 2010)

Control VOC Reductions NOx Reductions

Measure/Rule Title AdoptionDate Planned Actual Planned Actual 

CTS-02C(P2)

(Rule 1171) Solvent Cleaning Operations 1999 11.0 11.0* -- --

CTS-02E

(Rule 1168) Adhesives 2000 1.3 8.3 -- --

CTS-02O

(Rule 442) Solvent Usage 2000 1.0 1.9 -- --

CTS-07(P3)

(Rule 1113)

Architectural Coatings and Cleanup

Solvents -- 9.8 -- -- --

CTS-08(P1)

(Rule 1130) Industrial Coatings and Solvents 2002 2.0 1.9 -- --

CTS-08(P2)

(Rule 1122) Solvent Degreasing 2001 3.0 6.2 -- --

CTS-09(P1)

(Rule1132)

High Emitting Spray Booth

Facilities 2000 4.0 5.4 -- --

CTS-09(P2)

(Rule 1162) Polyester Resins 2002 3.0 1.6 -- --

FUG-05(P1)

(Rule 1178) Large Fugitive Sources 2001 1.0 1.7 -- --

FUG-05(P2) Large Fugitive Sources 2002 1.0 -- -- --

FUG-05(P3) Large Fugitive Sources -- 1.0 -- -- --

FUG-06

(Rule 1189) Hydrogen Plants 2000 0.8 1.6 -- --

RFL-02(P2)

(Rule 461) Gasoline Service Stations 2000 2.0 6.2 -- --

PRC-03(P2)

(Rule 1138) Restaurant Operations -- 0.9 -- -- --

PRC-06

(Rule 1131)

Industrial Processes – Food

Flavoring 2001 3.0 3.0 -- --

WST-01

(PR 1127) Livestock Waste -- 3.3 -- -- --

WST-04

(Rule 1150.1)

Disposal of VOC-Containing

Materials 2000 0.8 0.8 -- --

ADV-CLNG Solvent Cleaning and Degreasing -- 16.0 -- -- --

ADV-CTS Miscellaneous Industrial Coating

and Solvent Operations -- 6.0 -- -- --

ADV-FUG Fugitive Emissions -- 5.0 -- -- --

ADV-PRC Industrial Process Operations -- 1.0 -- -- --

Rule 1102 Non-Perc Dry Cleaners 2000 -- 0.3 -- --

Rule 1104 Wood Flat Stock Coating 1999 -- 0.1 -- --

CMB-06 Residential Type Natural Gas Fired

Water Heaters 1999 0.0 -- 7.6 7.6

Rule 1146 Boilers, Steam Generators, and

Process Heaters 2000 0.0 -- -- 0.2

TOTAL 76.1 50 7.6 7.8

REMAINING COMMITMENT FROM 1997/1999 SIP 26.1 (0.2)

* An additional 16 tons of VOC reductions from Rule 1171 are subject to technology assessments prior to rule

implementation in 2005 and are not included in this value, but are included in the 2010 baseline.
18

b. Proposed District Measures

The 2003 Plan indicates that the District's strategy in developing the proposed local

control measures was to: "1) meet, at a minimum, the same remaining emission

reductions committed to in the 1997/1999 SIP for the District portion; 2) replace the

long-term measures with more specific short-term measures, where feasible; and

3) identify new control measures to implement all feasible measures." 

The 2003 Plan includes a District commitment to achieve 52.5 tpd VOC and 5.1 tpd

NOx reductions from new measures or approved inventory changes. This includes a

near-term commitment for 21.5 tpd VOC reductions from defined measures and a

31 tpd VOC long-term commitment. Table III-6 lists the emissions inventory and

expected reductions for the District's near-term VOC and NOx control measures. 

The District's defined measures will continue progress in the near-term. Because of the

need for an additional 265 tpd VOC and 181 tpd NOx from long-term measures, ARB

staff has identified some opportunities that may allow the District to achieve additional

emission reductions to meet the region’s long-term attainment target. These

suggestions are generally based on development efforts in other districts and published

information on possible rule effectiveness improvements. Given the magnitude of the

long-term emission reduction needed, staff believes these opportunities should be

assessed as potential long-term strategies, along with additional strategies for sources

under State and federal jurisdiction. 
19

Table III-6

District Near-Term Control Measures for 2003 Ozone SIP

(South Coast Air Basin, Summer planning, tons per day in 2010)

Measure VOC NOx

Inventory Reductions Inventory Reductions

REMAINING 1997/1999 SIP CONTROL MEASURES

CTS-07: Architectural Coatings and Cleanup Solvents

(VOC) 28.3 8.5 -- --

CTS-10: Miscellaneous Industrial Coatings & Solvent

Operations (VOC) 16.3 3.0 -- --

FUG-05: Fugitive Sources (VOC) 15.0 2.0 -- --

MSC-01: Promotion of Lighter Color Roofing & Road

Materials & Tree Planting Programs (All Pollutants) -- TBD -- --

MSC-03: Promotion of Catalyst-Surface Coating

Technology (All Pollutants) -- TBD -- --

PRC-07: Industrial Process Operations (VOC) 16.9 2.0 -- --

WST-01: Livestock Waste (VOC) 11.0 4.8 -- --

WST-02: Composting (VOC) 6.8 1.2 -- --

FSS-04: Emission Charges of $5,000 per Ton for Large

Stationary Sources (VOC) -- TBD -- --

FLX-01: Economic Incentive Programs (All Pollutants) -- TBD -- --

NEW SIP CONTROL MEASURES

CMB-10: NOx RECLAIM (NOx) -- -- 35.7 3.0

MSC-05: Truck Stop Electrification (NOx) 0.14 -- 2.5 2.1

MSC-07: Natural Gas Fuel Specifications (NOx) -- TBD -- --

MSC-08: Large VOC Sources (VOC) -- TBD -- --

FSS-05: Mitigation Fee Program for Federal Sources (All

Pollutants) -- TBD -- --

FSS-06: In-Use Off-Road Vehicles and Equipment (All

Pollutants) -- TBD -- --

FSS-07: Emission Fee Program for Port-Related Mobile

Sources (All Pollutants) -- TBD -- --

TOTAL 94.3 21.5 38.2 5.1

CTS-07: Architectural Coatings and Cleanup Solvents This measure would

achieve additional emission reductions from District Rule 1113 by establishing lower

VOC limits for cleanup and thinning solvents, and for specified categories of

architectural coatings including clear wood finishes, exterior opaque stains, semitransparent stains, sanding sealers, and waterproofing sealers.
20

CTS-10: Miscellaneous Industrial Coating and Solvent Operations This measure

would require a further assessment of emissions from miscellaneous industrial coating

and solvent operations, and a technical assessment of further emission reduction

opportunities. The measure could utilize reformulation, control equipment, or other

strategies to reduce emissions from various industrial coatings and from aerospace

handwipe operations, alcohols used in manufacturing and clean room operations,

lubricants, and other solvent operation categories. 

ARB staff suggests that the District review the following rules for further emission

reduction potential in the assessment phase of CTS-10: Rule 481 (Spray Coating

Operations); Rule 1104 (Wood Flat Stock Coating Operations); Rule 1107 (Coating of

Metal Parts and Products); Rule 1122 (Solvent Degreasers); Rule 1125 (Metal

Container, Closure, and Coil Coating Operations); Rule 1126 (Magnet Wire Coating

Operations); Rule 1130 (Graphic Arts); Rule 1132 (High-Emitting Spray Booth

Facilities); Rule 1145 (Plastic, Rubber, and Glass Coating); Rule 1171 (Solvent

Cleaning Operations). Further emission reductions may be possible by eliminating

exemptions in these rules, increasing control efficiency requirements, or by reducing

VOC limits. 

FUG-05: Emission Reductions from Fugitive Sources This measure combines

three remaining commitments from the 1997/1999 SIP. It focuses on sources such as

oil and gas production facilities, petroleum and chemical products processing and

transfer facilities, refineries, and other fugitive sources. Implementation of this measure

would require development of a detailed emission inventory for these sources, and an

assessment of potential control technologies. 

The 2003 Plan includes a proposal to consider a pilot program that would establish a

cap for refinery emissions. Refineries that meet this target would be exempt from

further controls. The 2003 Plan indicates that the pilot program would provide refineries

with flexibility to achieve an overall emission reduction target in the most efficient and

cost-effective means, in lieu of complying with District prohibitory rules. It may be useful

to explore a cap approach for flexibility as emission reductions from these sources

become more technically difficult and expensive. If the District considers an approach

that would allow these facilities to meet a cap by obtaining emission reductions from

other sources (like vehicles and equipment), it is essential that emission reductions

surplus to the SIP are identified. 

MSC-01: Promotion of Lighter Color Roofing and Road Materials and Tree

Planting Programs The control measure would develop a program to promote the use

of light colored roofing and pavement, as well as tree planting to reduce temperatures

and improve air quality. The District proposes that these activities could be a required

element for new sources, included as recommendations through the District's California

Environmental Quality Act (CEQA) Air Quality Handbook, or eligible for generation of

emission reduction credits. Given the magnitude of reductions required to attain, we

recommend that the District consider applying any reductions to the region’s overall

attainment targets.
21

MSC-03: Promotion of Catalyst-Surface Coating Technology This measure would

encourage use of catalyst-surface coating technologies in residential and commercial

air conditioners to promote conversion of ground-level ozone and carbon monoxide into

oxygen and carbon dioxide. The District proposes that this technology could be a

required element for new sources, included as a recommendation through the District's

California CEQA Air Quality Handbook, or eligible for generation of emission reduction

credits. Given the magnitude of reductions required to attain, we recommend that the

District consider applying any reductions to the region’s overall attainment targets.

PRC-07: Industrial Process Operations The sources under this control measure are

permitted and unpermitted VOC sources involved in manufacturing or fabrication of

rubber, plastic, fiberglass or chemical compounds, and those involved in the processing,

handling or storage of VOC-containing materials. Potential control methods include

process modifications, add-on controls, enhanced inspection, or modifications to work

practices.

WST-01: Livestock Waste This measure from the 1997/1999 SIP focuses on

ammonia reductions to reduce the associated PM10 formation, and also has the

potential to reduce VOC emissions. The 2003 Plan indicates that the emission

inventory is decreasing because of dairies relocating outside the District (to the San

Joaquin Valley and eastern desert), updated population estimates, and Regional Water

Quality Control Board regulations. The District has not adopted a prohibitory rule to

reduce emissions from livestock waste. 

The District believes that additional VOC reductions could potentially be achieved

through use of anaerobic digesters and enclosed composting for animal waste, and

increased disposal of waste outside the District. The measure also commits to

decrease ammonia emissions through livestock relocation and/or potential controls. If

sufficient livestock relocation has occurred by January 1, 2004 to achieve a 50 percent

ammonia emission reduction from 1993 levels, the District proposes no action. If

ammonia controls are needed, the District will evaluate a number of approaches,

including enclosed composting, and increased out-of-Basin manure disposal. 

ARB staff encourages the District to focus on approaches that seek to reduce and

control emissions from livestock and their wastes in place. ARB staff is involved in

university studies examining VOC reactivity and emission factors for livestock waste, in

order to better understand the magnitude of livestock waste VOC emissions and the

benefits of potential controls. We will share the results with the District staff to aid

development of this measure. The San Joaquin Valley District staff is also looking at

ways to reduce livestock emissions. We encourage the South Coast District staff to

coordinate its efforts with the Valley. A common set of strategies could help ensure that

these operations reduce emissions as much as feasible, regardless of their location. 

WST-02: Composting This measure, adopted by the District in January 2003,

achieves 1.2 tpd VOC and 1.9 tpd ammonia reductions in 2010 by requiring: 1) existing

co-composting facilities that produce compost from sewage sludge or livestock manure
22

and bulking agents such as green waste to reduce VOC and ammonia emissions by 70

percent; 2) new co-composting facilities to apply specific controls or achieve 80 percent

emission reductions; and 3) chipping and grinding businesses, which process green

waste for use as a landfill cover, biomass fuel or composting feedstock, to limit the time

they hold or process green waste to prevent unintentional decomposition.

FSS-04: Emission Charges of $5,000 per Ton for Large Stationary Sources The

CAA requires that the District adopt a rule that provides for all stationary VOC sources

emitting more than 10 tons per year (tpy) in an extreme nonattainment area to pay a

$5,000 per ton emission fee, if U.S. EPA makes a formal finding that the area has failed

to attain the federal one-hour ozone standard by 2010. The fee (adjusted for inflation

since 1990) would be assessed on each ton of VOC emissions in excess of 80 percent

of each source’s 2010 emissions. 

FLX-01: Economic Incentive Programs This measure is intended to increase

compliance flexibility through activities such as trading of stationary and mobile source

emission credits, development of pilot credit trading rules between mobile and

stationary sources, and other market incentive approaches. Mobile source projects

used to subsidize growth in stationary source emissions should promote the early

introduction of new pollution control technologies. We encourage the District to

continue seeking additional feasible reductions from improved control technologies on

stationary facilities as well to help meet the region’s long-term attainment target. If the

District considers an approach that would allow these facilities to obtain emission

reductions from other sources (like vehicles and equipment), it is essential that emission

reductions surplus to the SIP are identified. 

CMB-10: NOx RECLAIM Under the District's Regional Clean Air Incentives Market

(RECLAIM) program, stationary sources emitting 4 tons per year or more of NOx or

SOx have the option of meeting control requirements for NOx or SOx through a facilitywide emissions allocation, or "cap." This facility cap can be met by either installing

controls, or by purchasing RECLAIM Trading Credits. Under the current SIP, emissions

allocated to RECLAIM sources were allowed to remain constant between 2003 and

2010. This measure would reduce the NOx allocation for RECLAIM facilities from 35.7

tpd to 32.7 tpd, or about eight percent, by 2010. 

District staff reported that many power plants achieved over 90 percent control when

they were temporarily removed from the RECLAIM program and required to comply with

District prohibitory rules. The power plants generated emission reductions of 0.5 to

2.5 tpd (annual average) in 2003, and up to 3.8 tpd in 2010, beyond those needed to

meet the RECLAIM cap.1 If these reductions are returned to the RECLAIM program as

RECLAIM credits, they will more than fulfill the District's proposed CMB-10 commitment

without any new controls. During rule development, we encourage the District staff to

evaluate whether a similarly effective overall level of control on the non-power plant

 

1 South Coast Air Quality Management District, Board letter, Recommendations Regarding Reentry of

Power Producing Facilities into RECLAIM Program, June 6, 2003 
23

sources in RECLAIM could achieve more NOx reductions to help meet the region’s

long-term needs. 

MSC-05: Truck Stop Electrification Many diesel-powered trucks must idle their

engines in order to provide power for heat, air conditioning, appliances, and other onboard systems, and must operate auxiliary engines to power trailer refrigeration units.

In order to eliminate excess idling at truck stops, this measure would require installation

of electric systems to provide power for the truck cab, and external power supplies for

transport refrigeration units on trucks. ARB staff is developing statewide measures to

reduce emissions from the engines used on transport refrigeration units and from truck

idling. ARB staff intends to work with the District staff developing this infrastructure

measure to ensure that the local rule for truck stops compliments ARB's requirements

for trucks and auxiliary engines.

MSC-07: Natural Gas Fuel Specifications Elevated higher heating values of hot gas

relative to normal gas results in higher combustion temperature and increased NOx

emissions. This measure would establish a maximum heating value limit for natural gas

sold in the District.

MSC-08: Large VOC Sources This measure would require facilities to submit a plan

outlining measures they would implement to achieve a specific emission reduction

target beyond that achieved by existing regulations. Mechanisms to achieve additional

reductions could include add-on controls, process controls, product reformulations,

mitigation fees, or other measures. Since all District sources of VOC account for 30

percent of emissions in 2010, we encourage the effort to challenge sources to identify

the most effective way to achieve further emission reductions.

FSS-05: Mitigation Fee Program for Federal Sources This measure would establish

a fee program for sources under federal jurisdiction that operate in the Basin. The

District envisions that U.S. EPA would adopt the proposed program, with the funds

provided to the District through U.S. EPA rulemaking and/or grants. FSS-05 is

structured to reduce local emissions from federal sources without requiring the

imposition of national controls. The District proposes to solicit and fund projects with

the collected fees to reduce emissions from either federal or non-federal sources. The

2003 Plan does not quantify or credit emission reductions from this measure in the

attainment demonstration.

ARB staff concurs that significant emission reductions are needed from sources under

federal jurisdiction, and supports the concept of requiring that these sources contribute

(directly or indirectly) to meeting the region's emission reduction targets. U.S. EPA has

the authority to promulgate regional regulations, whether control requirements or

mitigation fees, in lieu of controls. If funding can be secured, the District will need to

address issues such as: the enforceability and quantification of emission reductions,

project selection criteria, location of emission reduction projects relative to mitigated

sources, and program oversight. ARB staff will provide additional comments on this

measure as these details emerge. 
24

FSS-06: In-Use Off-Road Vehicles and Equipment The District is pursuing the legal

authority to regulate existing mobile sources through strategies such as retrofit controls

or mitigation fees. Under this measure, the District would develop regulations to require

the retrofit of existing off-road engines, or to accelerate engine turnover. 

ARB and U.S. EPA have primary authority to establish broad-based emission reduction

programs for mobile sources. However, the District fleet rules (which are already

authorized under State law) and various mobile source incentive programs have

demonstrated that there are options that can be implemented locally to help accelerate

the reductions from existing mobile sources. ARB staff is supportive of District actions

that are consistent with State law and fully coordinated with the statewide program to

achieve additional feasible and cost-effective emission reductions. 

FSS-07: Emission Fee Program for Port-Related Mobile Sources The District

proposes an emissions fee program for in-use port-related mobile sources such as

ships, trains, trucks, off-road equipment, and other vehicles and equipment. The District

would use funds collected from the program to achieve additional emission reductions

from on- and off-road mobile sources. ARB staff supports efforts to reduce emissions

from the ports, especially in the absence of more stringent emission standards for

federal and international sources. However, as with FSS-05, details about program

implementation and oversight have not yet been resolved. We will provide additional

comments on this measure as these details emerge.

Contingency Measures Section 172(c)(9) of the Clean Air Act requires the SIP

provide for contingency measures. In measure CTY-01: Accelerated Implementation of

Control Measures, the District proposes to move up implementation of all District

controls with a post-2003 implementation date if contingency provisions are triggered.

This measure would not affect the total reductions achieved. The District has listed

ARB as an implementing agency for CTY-01. ARB staff is not proposing a State

commitment for this measure because the adopted mobile source controls generate

increasing benefits over time and provide contingency reductions after the attainment

date.

Additional Opportunities for Further Reductions To meet the ozone attainment

targets, all agencies are seeking opportunities for further VOC and NOx reductions. In

addition to the suggestions described above, we offer the following preliminary ideas for

the District staff to consider as possible long-term mechanisms to achieve additional

VOC and NOx reductions, along with additional strategies for sources under State and

federal jurisdiction, to help meet the region’s attainment target.

 Petroleum Refinery Flares -- The District has included CMB-07: Emission

Reductions from Petroleum Refinery Flares, as a commitment in the proposed

revisions to the PM10 SIP to reduce SOx emissions. The measure will be fully

implemented by the PM10 attainment deadline of 2006. The District anticipates
25

concurrent reductions in VOC, NOx, CO, and PM10 emissions, but does not include

them in its near-term control strategy. 

Because District Rule 1118 requires refineries to monitor refinery flare emissions, we

believe the District will be in a good position to estimate the VOC and NOx benefits

that would accrue from this measure as rule development progresses. We

encourage the District to apply any resulting benefits to help meet the region’s

overall VOC and NOx reduction needs.

The Bay Area Air Quality Management District (Bay Area) is actively developing a

refinery flare rule as part of its Ozone Plan. We encourage the District staff to

coordinate with Bay Area staff to maximize the results of these efforts.

 Wood Products Coatings – We encourage the District to evaluate the potential

benefits of amending Rule 1136 to eliminate the exemption for residential

noncommercial applications or implement a usage cap for this exemption. The

requirements of Sacramento District Rule 463 may provide opportunities for

additional reductions.

 Metal Container, Closure, and Coil Coating Operations -- We encourage the District

to evaluate the potential benefits of amending Rule 1125 to eliminate the one gallon

per day low use exemption and lower the VOC limits for certain can and coil

products. The requirements of San Diego District Rule 67.4 may provide

opportunities for additional reductions.

 Marine Coating Operations -- We encourage the District to evaluate the potential

benefits of amending Rule 1106 to lower the product VOC limits for specific marine

coating products. The requirements in place in San Diego may provide opportunities

for additional reductions. 

 Fleet Rules -- The District is reducing both toxic and criteria pollutants with its fleet

rules for sources like school buses, trash trucks, and street sweepers. The benefits

of the District fleet rules are not reflected in the 2003 Plan. We encourage the

District to revisit the emission reductions from local fleet programs by 2007 so those

benefits can be included when we reassess the emission reductions needed from

long-term measures. 

c. Structure of District Commitment

The structure of the District's commitment in the 2003 SIP is similar to the approach

used in the 1997/1999 SIP, with the addition of a proposal to credit emission decreases

that result from changes in the inventory methodology or growth assumptions towards

the District's emission reduction obligations. The District includes an enforceable

commitment to bring each of its control measures to the District Governing Board and to

meet a residual emissions target that would be achieved via emission controls or

inventory adjustments. If a particular SIP measure does not achieve the anticipated
26

emission reductions, the District must adopt alternate strategies to fulfill the overall SIP

commitment on time. Table III-7 shows the District's proposed schedule for emissions

reductions through adoption and implementation of near-term measures or inventory

changes.

Table III-7

District Near-Term Emission Reduction Commitments

(South Coast Air Basin, Summer planning, tons per day in 2010)

VOC NOx

Year Based on

Adoption

Date

Based on

Implementation

Date

Based on

Adoption

Date

Based on

Implementation

Date

2002 0.6 -- -- --

2003 16.9 0.6 -- --

2004 2.0 -- 3.0 --

2005 2.0 -- 2.1 --

2006 -- 4.8 -- --

2007 -- 2.0 -- 2.1

2008 -- 12.1 -- --

2009 -- -- -- --

2010 -- 2.0 -- 3.0

TOTAL 21.5 21.5 5.1 5.1

The District proposes to measure its compliance based on remaining emissions in 2010,

allowing emission decreases that result from changes in the inventory methodology or

growth assumptions to be credited towards its emission reduction commitment shown in

Table III-7. Such inventory changes would have to be peer reviewed and approved by

the District Governing Board to be eligible for SIP credit. The 2003 Plan does not

indicate whether inventory methodology changes that result in emission increases

would increase the District's control responsibilities under the new commitments. The

District’s approach could result in a different net change in emissions from local sources

over time than anticipated in the 2003 Plan. The 2007 SIP revision will need to

reconcile any changes in inventory or control effectiveness from the District’s near-term

measures with an updated attainment demonstration to reassess the long-term

emission reduction needs. 

ARB has assessed State and federal SIP progress based on emission reductions

achieved relative to the approved SIP inventory, consistent with the modeled attainment

demonstration. We believe this approach allows an accurate assessment of the control

effectiveness achieved versus the effectiveness anticipated in a plan. ARB will continue

to track State and federal progress using this SIP inventory currency approach. 
27

d. Transportation Strategy

The 2003 Plan includes a VOC, NOx, and carbon monoxide emission reduction

commitment from SCAG, resulting from implementation of its Regional Transportation

Plan (RTP) and Transportation Control Measures (TCMs). SCAG's commitment to

achieve emission reductions in the Basin is shown in Table III-8.

Table III-8

SCAG 2010 Emission Reduction Commitment 

(South Coast Air Basin, Summer planning, tons per day)

Pollutant Entire RTP

(includes TCMs)

Subset of

TCMs Only

VOC 15.7 5.6

NOx 7.8 1.0

CO 161.8 60.8

Emission reductions from the RTP are from an expected lower rate of growth in motor

vehicle activity due to an improved regional balance between the location of jobs and

housing, as well as increased average vehicle speeds and reduced vehicle trips due to

transportation measures. The TCMs in the 2003 Plan fall in the following categories:

 High Occupancy Vehicle (HOV) Measures: Construction and dedication of new

HOV lanes, and differential tolls for HOVs.

 Transit System and Management Measures: Bus, rail, and shuttle transit expansion

and improvements; park and ride lots and inter-modal transfer facilities; bicycle and

pedestrian facilities; railroad consolidation programs, such as grade separation

projects; intersection improvements; and traffic signalization.

 Information-Based Strategies: Programs that promote alternatives to single

occupancy vehicle commutes, and improve congestion management strategies.

Since the transportation sector is the largest contributor to air pollution in Southern

California, it must also be the primary source of emission reductions as well. The

magnitude of long-term emission reductions needed for attainment require not only a

commitment to cleaner vehicles, but also to a lower-emitting transportation system. The

work currently being done in many SCAG task forces on the development of the 2004

RTP includes draft policies, actions, and growth scenarios that could help produce

sustainable emission reductions through reduced vehicle trips and trip lengths. We

encourage SCAG to bring these "green" planning measures before its committees and

Regional Council to provide an opportunity for the RTP not only to meet the

transportation needs of the region but also to provide the maximum air quality benefits

possible. ARB staff expects that SCAG will be an active partner in the process to

identify and implement the new long-term strategies needed to attain our air quality

goals.
28

2. State Control Strategy

The 2003 Plan for ozone, PM10, carbon monoxide, and nitrogen dioxide relies on the

significant benefits of the existing State control program. The State will continue leading

the effort to improve air quality in the South Coast and statewide, providing a greater

share of the emission reductions than contributed by sources under its jurisdiction. This

is essential since these sources are major contributors to the overall emissions. State

actions to date are delivering three-fourths of all emission reductions adopted between

the 1997 baseline and 2010 to reduce ozone in the South Coast. The ozone SIP

element of the 2003 Plan depends on further State reductions based on ARB staff’s

draft proposal for new near-term and long-term measures. 

ARB is responsible for controlling emissions from mobile sources (except where federal

law preempts ARB's authority) and consumer products, developing fuel specifications,

establishing gasoline vapor recovery standards and certifying vapor recovery systems.

The Bureau of Automotive Repair (BAR) administers California's vehicle inspection and

maintenance program, known as "Smog Check", while the Department of Pesticide

Regulation (DPR) is responsible for regulating pesticides for commercial/structural and

agricultural uses.

(Note: although the State’s emission reduction commitments are expressed in terms of

reactive organic gases or ROG, we use the VOC label here for consistency with the

local elements of the 2003 Plan.)

a. Progress Since 1994 SIP

Most of the existing near-term State measures from the 1994 SIP have been adopted,

along with additional measures to reduce emissions. These include strategies to

reduce emissions from cars, trucks, buses, motorcycles, marine pleasurecraft, off-road

engines and equipment, fuels and fuel dispensing, consumer products, pesticides, and

other sources. Table III-9 shows that these measures fulfill most of the existing nearterm VOC reduction commitment and exceed the total State commitment for near-term

and long-term NOx reductions. The 1997/1999 SIP did not alter the State or federal

strategy but updated the SIP commitment based on that Plan's new inventory. The

benefits of State measures adopted through October 2002 are reflected in the 2003

Plan baseline.
29

Table III-9

State Measures Adopted Since 1994 SIP

(As of October 2002, based on South Coast 1997/1999 SIP inventory, tons per day in 2010)

VOC Reductions NOx Reductions

Near-Term Measures Adopted CommitmentAchieved

in 2010

CommitmentAchieved

in 2010

M1: Light-duty vehicle scrappage 1998 0 0

M2: Low Emission Vehicle II program 1998 19 4 17 43

M3: Medium-duty vehicles 1995 Baseline1 - Baseline1 -

M4: Incentives for clean engines (Moyer Program) 2 1999 0 0 1 3

M5: California heavy-duty diesel vehicle standards2 1998 6 5 42 44

M7: Heavy-duty vehicle scrappage2 Replaced

with M17 1 NA 7 NA

M17: In-use reductions from heavy-duty vehicles No 0 0

M8: Heavy-duty gasoline vehicle standards 1995 Baseline1 - Baseline1 -

M9: CA heavy-duty off-road diesel engine

standards2 2000 1 4 20 18

M11: CA large off-road gas/LPG engine standards2 1998 15 16 8 5

CP2: Consumer products mid-term measures 1997/1999 34 15 0 0

CP3: Aerosol paint standards 1995/1998 Baseline1 - - -

Enhanced I/M (Smog Check II) (BAR) 1995 Baseline1 (6) Baseline1 -

DPR-1: Emission reductions from pesticides (DPR) Voluntary 1 1 0 0

Adopted measures not originally included in SIP

Clean fuels measures Multiple 13 12

Marine pleasurecraft (reductions beyond M16) 1998/2001 7 0

Motorcycle Standards 1998 1 0

Urban transit buses 2000 0 1

Enhanced vapor recovery program 2000 6 0

Medium/heavy-duty gasoline standards (beyond M8) 2000 0 1

2007 heavy-duty diesel truck standards 

(beyond M5 and M6) 2001 1 12

Small off-road engine standard revisions 1998 (1) 0

NEAR-TERM TOTAL 77 66 95 139

Long-Term Measures (Section 182(e)(5))

Advanced technology on-road mobile measures No 37 0 6 -

3

Advanced technology off-road mobile measures No 18 0 3 -

3

CP4: Long-term measure for consumer products No 43 0 0 0

LONG-TERM TOTAL 98 0 9 -

3

GRAND TOTAL (near-term + long-term) 177 66 105 139

Emission reductions from individual measures may not add to total due to rounding. 

( ) = Emission increase relative to baseline.

1

 Measures M3, M8, CP3, and the Smog Check II program from the 1994 SIP had already been adopted

when the SIP was revised in 1997. The reductions from these measures are included in the 1997/1999 SIP

baseline. Although the Smog Check II program is achieving significant benefits, the emission reductions are

less than anticipated in the 1997/1999 SIP as indicated by the negative number under reductions achieved. 2

 The 1997/1999 SIP combined the ARB/U.S. EPA commitment for measures M-4 through M-7, M-9 and 

M-10, and M-11 and M-12. The emission reduction commitment for the grouped measures have been

disaggregated based upon the relative commitment for each measure in the 1994 SIP.

3

 The NOx reductions anticipated from the long-term mobile source commitment have already been achieved

from adopted measures.
30

b. Proposed State Measures

ARB staff is proposing that the State commit to additional reductions of 49 tpd VOC and

37 tpd NOx in South Coast in 2010 through new measures to be adopted between

2003-2006. The State’s strategy includes 19 near-term defined measures that ARB

staff would develop, plus BAR’s planned improvements to the Smog Check program

and continuation of DPR’s existing commitment to reduce volatile emissions from

pesticides. The ARB measures cover on-road vehicles, off-road equipment, marine

vessels/ports, fuels and refueling, and consumer products. Lower emission standards

for new engines and consumer products are complemented by measures to clean up

the existing fleet of mobile sources. Other measures would reduce gasoline vapor

emissions from storage tanks, service stations, and fuel tanker trucks. Tighter limits on

fuel properties are also proposed. Table III-10 summarizes the measures and the

expected emission reductions. 

Process As the Board neared adoption of all the defined measures in the 1994 SIP,

ARB staff began to outline the next generation of State and federal control measures.

In 2001, we initiated a public process to identify new emission reduction strategies for

California. In January 2003, ARB staff released a draft document focused on potential

measures for sources under State and federal authority that would help reduce ozone

and PM10 by 2010. Following twelve public workshops, we issued the Proposed State

and Federal Strategy for the California SIP on May 12, 2003. The 2003 Plan for the

South Coast Air Basin anticipates the new near-term measures and proposed State

commitment for emission reductions in 2010 that are described in the May document.

The Air Resources Board will consider adoption of the State Strategy prior to the 2003

South Coast Ozone SIP since the State commitment is essential to complete the SIP’s

attainment demonstration. 

On August 25, 2003, we released the Revised Proposed State and Federal Strategy for

the California SIP (State and Federal Strategy) based on subsequent information. This

revision retains the same near-term emission reduction commitments for the South

Coast. The measures and strategies are largely unchanged except for consolidation of

two measures proposed for large spark-ignited equipment like forklifts. The new

consolidated strategy is contained in OFF-RD LSI-2: Clean Up Off-Road Gas

Equipment Fleet Through Retrofit Controls and New Emission Standards (Spark Ignition

Engines 25 hp and Greater). 

The August version also reflects the Board’s June 26, 2003 approval of the State

commitments for the San Joaquin Valley PM10 SIP, and its July 24, 2003 adoption of

low-sulfur requirements for on-road and off-road diesel fuel throughout California.

Another significant addition is the proposed State long-term strategy for the South

Coast, including staff’s proposal if U.S. EPA does not carry out its responsibilities for

new emission reductions. We also included minor updates to the range of anticipated

reductions and timing for a few near-term measures without changing the overall

benefits of the proposed State commitment. The Revised State Strategy is available at:

http://www.arb.ca.gov/planning/sip/sip.htm.
31

 

Table III-10

Proposed State Near-Term Measures for 2003 Ozone SIP

(South Coast Air Basin, Summer planning, tons per day)

Expected

Reductions

(South Coast 2010)*

Strategy

(Agency) Name

Final

Action

Date

Implementation

Date

VOC NOx

DEFINED STATE MEASURES TO BE DEVELOPED AND PROPOSED

LT/MEDDUTY-1

(ARB)

Replace or Upgrade Emission Control

Systems on Existing Passenger Vehicles

– Pilot Program

2005 2007-2008 0-19 0-18

LT/MEDDUTY-2

(BAR)

Improve Smog Check to Reduce

Emissions from Existing Passenger and

Cargo Vehicles

2002-2005 2002-2006 5.6-5.8 8.0-8.4

ON-RD 

HVY-DUTY-1

(ARB)

Augment Truck and Bus Highway

Inspections with Community-Based

Inspections

2003 2005 0-0.1 0

ON-RD 

HVY-DUTY-2

(ARB)

Capture and Control Vapors from

Gasoline Cargo Tankers 2005 2006-2007 4-5 0

ON-RD 

HVY-DUTY-3

(ARB)

Pursue Approaches to Clean Up the

Existing and New Truck/Bus Fleet 2003-2006 2004-2010 1.4-4.5 8-11

OFF-RD CI-1

(ARB)

Pursue Approaches to Clean Up the

Existing Heavy-Duty Off-Road Equipment

Fleet (Compression Ignition Engines) –

Retrofit Controls

2004-2008 2006-2010 2.3-7.8 NQ

OFF-RD CI-2

(ARB)

Implement Registration and Inspection

Program for Existing Heavy-Duty OffRoad Equipment to Detect Excess

Emissions (Compression Ignition

Engines) 

2006-2009 2010 NQ NQ

OFF-RD 

LSI-1

(ARB)

Set Lower Emission Standards for New

Off-Road Gas Engines (Spark Ignited

Engines 25 hp and Greater)

2004-2005 2007 0 0.8

OFF-RD 

LSI-2**

(ARB)

Clean Up Off-Road Gas Equipment

Through Retrofit Controls and New

Emission Standards (Spark-Ignition

Engines 25 hp and Greater)

2004 2006-2012 0.8-2.0 2-4

SMALL 

OFF-RD-1

(ARB)

Set Lower Emission Standards for New

Handheld Small Engines and Equipment

(Spark Ignited Engines Under 25 hp such

as Weed Trimmers, Leaf Blowers, and

Chainsaws) 

2003 2005 1.9 0.2

SMALL

OFF-RD-2

(ARB)

Set Lower Emission Standards for New

Non-Handheld Small Engines and

Equipment (Spark Ignited Engines Under

25 hp such as Lawnmowers)

2003 2007 6.3-7.4 0.6-1.9
32

Expected

Reductions

(South Coast 2010)*

Strategy

(Agency) Name

Final

Action

Date

Implementation

Date

VOC NOx

MARINE-1

(ARB)

Pursue Approaches to Clean Up the

Existing Harbor Craft Fleet – Cleaner

Engines and Fuels

2003-2005 2005 0.1 2.7

MARINE-2

(ARB)

Pursue Approaches to Reduce LandBased Port Emissions – Alternative

Fuels, Cleaner Engines, Retrofit Controls,

Electrification, Education Programs,

Operational Controls

2003-2005 2003-2010 0.1 0.1

FUEL-1

(ARB)

Set Additives Standards for Diesel Fuel to

Control Engine Deposits 2006-2009 2006-2010 NQ NQ

FUEL-2

(ARB)

Set Low-Sulfur Standards for Diesel Fuel

for Trucks/Buses, Off-Road Equipment,

and Stationary Engines

2003 2006 Enabling Enabling

CONS-1

(ARB)

Set New Consumer Products Limits for

2006 2003-2004 2006 2.3 0

CONS-2

(ARB)

Set New Consumer Products Limits for

2008-2010 2006-2008 2008-2010 8.5-15 0

FVR-1

(ARB)

Increase Recovery of Fuel Vapors from

Aboveground Storage Tanks 2003 2007 0-0.1 0

FVR-2

(ARB)

Recover Fuel Vapors from Gasoline

Dispensing at Marinas 2006-2009 2006-2010 0-0.1 0

FVR-3

(ARB)

Reduce Fuel Permeation Through

Gasoline Dispenser Hoses 2004 2007 0-0.7 0

PEST-1

(DPR) Implement Existing Pesticide Strategy --- 1996-2010 Baseline N/A

Potential Range for Defined Near-Term State Measures 33.3-71.9 22.4-47.1

Minimum Commitment via Adoption 2003-2006 49 37

c. Structure of Proposed State Commitment

ARB staff is proposing a three-tiered commitment, as detailed in the State Strategy

document. The foundation is a near-term commitment to develop and propose for

Board consideration 19 defined statewide control measures listed for ARB in

Table III-10. The Board could take any action within its discretion in response to these

proposals. The next element is an annual commitment to adopt measures through

2006 to achieve specified further emission reductions in the South Coast as shown in

Table III-11. The final tier is a long-term commitment to identify additional measures by

2007. These measures would be adopted between 2007 and 2009 in order to reach

attainment targets for the federal one-hour ozone standard in the South Coast by 2010. 
33

Table III-11 

Proposed State Annual Adoption Commitments for Near-Term Measures

2003 Ozone SIP

(South Coast Air Basin, Summer planning, Emission reductions in tons per day)

2003 2004 2005 2006 Total State Reductions from

Near-Term Measures

VOC 10 4 21 14 49

NOx 11 5 21 0 37

3. Federal Responsibility

Sources of emissions under exclusive federal jurisdiction include cars and trucks

registered outside of California which travel within the State, new pre-empt farm

equipment and construction equipment, locomotives, marine vessels and aircraft, as

well as fuel sold outside California for these engines. Federal agencies also have the

lead role representing the United States in the process of developing standards for

international aircraft and marine vessels.

Like State and local agencies, the federal government has a responsibility to further

control emissions. The federal Clean Air Act directs U.S. EPA to continue reducing

mobile source emissions that cause or contribute to air pollution that endangers public

health. The ozone and particulate levels in the South Coast clearly meet this test.

U.S. EPA needs to pursue new requirements for national and international sources, and

complement them with incentives to speed turnover of the diesel fleet to cleaner

engines. Federal action is essential to meet health-based air quality goals in this region

and other parts of the State. 

While U.S. EPA is proposing several initiatives that would help reduce emissions, the

agency has stated its unwillingness to make a legal commitment for any new emission

reductions to be credited in the 2003 Ozone SIP for the South Coast Air Basin.

U.S. EPA has also stated its intention to disapprove the 2003 Ozone SIP if it explicitly

relies on federal action to achieve any further reductions in the attainment

demonstration. As a result, there are no near-term federal control measures in the 2003

Plan. 

This section briefly identifies what federal agencies have done to reduce ozone-forming

emissions in the South Coast Air Basin since adoption of the 1994 Ozone SIP and

describes the expected emissions contribution from federal sources in 2010 after

implementation of the adopted controls. We cover potential concepts for additional

federal actions under the Long-Term Strategy discussion. 

a. Progress Since 1994 SIP

U.S. EPA and ARB have partnered effectively, sharing technical resources to develop

new emission standards and other approaches to reduce emissions from source
34

categories under shared authority. For example, parallel regulations will require 98

percent control on new heavy-duty trucks, when fully implemented by 2010. The

national emission standards for these vehicles are vital to reducing NOx and particulate

emissions to meet health-based air quality standards and reduce the cancer risk from

exposure to diesel particulate matter. The NOx and VOC benefits of U.S. EPA

measures adopted since the 1994 SIP are shown in Table III-12. These emission

reductions are reflected in the Plan baseline inventory.

Table III-13

Federal Measures Adopted Since 1994 SIP

(As of October 2002, based on South Coast 1997/1999 SIP inventory, tons per day in 2010)

VOC Reductions NOx Reductions

Near-Term Measures Adopted CommitmentAchieved

in 2010

CommitmentAchieved

in 2010

M6: National heavy-duty diesel vehicle standards1 1998 2 1 12 11

M10: National heavy-duty off-road diesel engine

stds1

1998 3 6 26 25

M12: National large off-road gas/LPG engine stds1 2002 17 14 9 5

M13: Marine vessel standards 1999 0 0 15 2

M14: Locomotive engine standards 1997 0 0 17 17

M15: Aircraft standards No 3 0 6 0

M16: Marine pleasurecraft standards 1996 21 17 0 0

Adopted measures not originally included in SIP

2007 heavy-duty diesel truck standards (beyond M5

and M6)

2001 0 4

NEAR-TERM TOTAL 46 39 85 64

 

Emission reductions from individual measures may not add to total due to rounding. 1

 The 1997/1999 SIP combined the ARB/U.S. EPA commitment for measures M-4 through M-7, M-9 and

M-10, and M-11 and M-12. The emission reduction commitment for the grouped measures have been

disaggregated based upon the relative commitment for each measure in the 1994 SIP.

b. Emissions Contribution

The emission sources under the exclusive legal or practical control of the federal

government account for over 30 percent of NOx emissions and 60 percent of diesel

particulate emissions in the South Coast in 2010. Federal sources will contribute

approximately eight percent of the 2010 ROG emissions. 

Despite continued population and travel growth, ozone-forming emissions from most

sources are declining over time due to the effectiveness of adopted controls. However,

net emissions from marine and aircraft categories are rising. Between 2000 and 2010

in the South Coast, the total NOx emissions from marine vessels are projected to

increase over 20 percent because the effects of activity growth are greater than the

benefits of current controls. In contrast, total NOx emissions will drop by 60 percent for

passenger vehicles and 30 percent for trucks over the same period in that region. As
35

State and local agencies continue to make commitments and adopt new measures, the

relative contribution of emissions from sources under federal control will increase even

faster. 

c. New Federal Actions to Reduce Emissions 

As U.S. EPA and ARB continue to coordinate on future rulemaking, U.S. EPA is

developing three specific proposals to reduce emissions from federal sources. First,

U.S. EPA has proposed more stringent emission standards for new off-road diesel

equipment based on the transfer of emission control technology for on-road engines.

The benefits will be critical in the post-2010 timeframe, both to offset growth and to

make progress toward the new, more stringent federal ambient air quality standards.

Second, U.S. EPA proposes to phase in the use of low sulfur diesel fuel in off-road

applications nationwide. This will enable the use of more sophisticated control

technology on off-road diesel engines. Third, U.S. EPA is working in parallel with

California to develop on-board diagnostics and to strengthen manufacturers’ in-use

testing to ensure that new heavy-duty trucks and buses maintain expected emission

levels throughout their useful lives. However, U.S. EPA has not proposed to take any

legal responsibility for achieving additional reductions needed for ozone attainment in

the South Coast.

4. Long-Term Strategy

The federal Clean Air Act recognizes that extreme ozone nonattainment areas, such as

the South Coast, must rely on evolving technologies to meet attainment goals.

Consistent with section 182(e)(5) of the Act, prior SIPs for South Coast have included a

long-term commitment to achieve the last increment of emission reductions, with the

remaining measures to be defined by 2007. 

After accounting for the anticipated benefits of both adopted and new near-term defined

State and local measures, the 2003 SIP demonstrates a need for another 265 tpd ROG

reductions and 181 tpd NOx reductions from long-term measures. This represents 30

percent of the total reductions needed by 2010. 

We believe that this gap can be bridged through a cooperative effort by the local, State

and federal agencies responsible for specific emission sources. This effort should

focus on how to most effectively achieve the additional reductions, considering the

availability and cost of potential controls. As the State agency charged with ensuring

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

measures are identified by 2007 and the emission reductions are achieved by 2010.

a. Primary Attainment Strategy

State ARB staff has proposed to lead a multi-agency (State, federal, local) effort with

the public to assess potential control concepts for every type of emission source and

develop the full scope of strategies needed to achieve these reductions. In the
36

Proposed State and Federal Strategy, we identify potential long-term emission reduction

concepts to explore for mobile sources, fuels, consumer products, and pesticides, as

well as programs to inform consumer choices. We have also received suggestions from

others. In early 2004, ARB staff plans to initiate a public process to solicit further ideas

to begin development of the long-term measures. 

Federal Based on the emissions from sources under federal jurisdiction, the 2003 Plan

identifies a federal responsibility for additional reductions of 68 tpd NOx and 18 tpd VOC

by 2010 to help attain the federal one-hour ozone standard in the South Coast. Longterm strategies for new engines in locomotives, ocean-going ships, harborcraft, and

commercial and non-tactical military aircraft are feasible and effective means to cut

emissions and will be critical to make progress toward all of the national air quality

standards. Because of the extended life of these engines, we believe the long-term

strategy will need to rely heavily on programs to replace existing engines with cleaner

models or to add emission control equipment. Given the volume of equipment in

operation and the public health impact of the emissions, it is important that U.S. EPA

and its federal partners take early action in this regard. The State and Federal Strategy

document includes concepts that the federal government should consider to achieve

these reductions, as summarized in Table III-13.

Table III-13

ARB Staff Concepts for Federal Action

On-Board Diagnostics for New Truck/Bus Fleet and In-Use Testing for Existing

Truck/Bus Fleet

Lower Emission Standards for New Off-Road Compression Ignition Engines

Low-Sulfur Standards for Diesel Fuel for Off-Road Equipment, Locomotives, and Marine

Vessels

More Stringent Emission Standards for New Harbor Craft and Ocean-Going Ships

Clean Up the Existing Ocean-Going Ship Fleet through Approaches such as Cleaner

Fuels, Incentives for Cleaner Ships, Smoke (Opacity) Limits

Reduce Emissions from Jet Aircraft through Approaches such as More Stringent Engine

Standards, Retrofit Controls, Cleaner Fuel, and Applying Standards to Non-Tactical

Military Aircraft

More Stringent Emission Standards for New and Remanufactured Locomotive Engines

Incentives to Accelerate Clean Up of Existing Diesel Engines

Local The District adopted a two-part commitment for long-term VOC measures:

(a) Tier I with 11 tpd VOC reductions to be adopted 2005-2007 and implemented 2007-

2009; and (b) Tier II with 20 tpd VOC reductions to be adopted 2006-2008 and

implemented 2008-2010. Although sources under District jurisdiction contribute over

ten percent of NOx emissions in 2010, the District did not propose any long-term NOx

commitment. 
37

The District identified several mechanisms to develop the strategies to achieve the VOC

reductions, including: working with the public via advisory groups and technical forums,

updating the emission inventory assumptions (see discussion under Structure of District

Commitment), considering reactivity-based approaches, and conducting periodic

technology evaluations. As potential new measures are defined, the District staff will

update the District Governing Board each December. 

Over the next four years, the District will also evaluate the legal, technical, and

economic feasibility of 12 strategies suggested by stakeholders – ten are for mobile

sources, primarily at ports. In 2004-2008, District staff will propose for District

Governing Board consideration any of these measures that it has found to be feasible

and within the District’s legal authority.

Recommendation In the 2003 Plan, the District assigned responsibility for all of the

long-term emission reductions by agency -- 31 tons of VOC to itself and the remaining

234 tons of ROG and all 181 tons of NOx reductions to be achieved by ARB and U.S.

EPA. We view this as a placeholder between now and 2007, when the long-term

measures must be defined. Until that process is complete, the relative long-term

emission reduction split among agencies can’t realistically be defined. Nonetheless, it’s

clear that ARB, U.S. EPA, the District and local government need to obtain additional

reductions and we acknowledge ARB’s responsibility to ensure that measures to

achieve those reductions are ultimately identified and implemented.

To reconcile the District’s adopted strategy with ARB staff’s recommendations, we have

proposed that: (1) the Board approve the District commitment for 31 tpd long-term VOC

reductions and the targets for the federal government of 18 tpd ROG and 68 tpd NOx

reductions, and (2) the State assume overall responsibility to assure that measures are

identified by 2007 and implemented by 2010 to achieve the remaining 216 tpd ROG and

113 tpd NOx reductions needed for ozone attainment in the South Coast. 

We believe that all agencies must actively seek to identify additional cost-effective

control strategies to achieve the maximum feasible reductions from all source

categories. Part of this evaluation will include a discussion of which agency or agencies

can most effectively obtain the emission reductions in practice. We expect that the

appropriate agency will begin development as soon as practicable. Once all of the

specific long-term measures are identified, the resulting reductions to be achieved by

each agency may be different than envisioned by the District. 

By 2007, the District and ARB will prepare a revision to the Ozone SIP that (1) reflects

any modifications to the carrying capacity based on updated science, and (2) identifies

the additional strategies, including the implementing agencies, needed to achieve the

necessary emission reductions by 2010. 
38

b. Alternative Attainment Strategy

ARB intends to continue working with the U.S. EPA and other federal agencies on both

near-term activities and the long-term strategy. However, we do not yet have

assurance that the federal government will achieve the emissions targets in the needed

timeframe.

If U.S. EPA does not accept the primary attainment strategy (called Option 1) that sets

emission targets based on reductions from local, State, and federal elements, the

District created an alternative strategy (Option 2) that excludes reductions from federal

sources and modifies the attainment emission targets. If Option 2 is triggered, the

District proposes to relax the NOx control target by 68 tpd (the federal responsibility)

and assign the federal 18 tpd VOC reductions to ARB. As discussed in section III.B, the

modeling shows that the South Coast Air Basin could demonstrate attainment with the

Option 2 strategy. 

However, the attainment emission targets in Option 1 provide the greatest protection for

public health and the best foundation for meeting the upcoming federal fine particulate

and eight-hour ozone standards. (NOx is the dominant contributor to PM2.5 in the

Basin.) Achieving federal PM2.5 standards will require aggressive action over the next

decade to demonstrate attainment by the 2014 federal target. 

Because stringent NOx control is essential for addressing the health threat from fine

particulate pollution, ARB staff is proposing that the Board allow the federal reductions

of 18 tpd ROG and 68 tpd NOx to be added to the overall State long-term commitment if

U.S. EPA does not agree to carry out its legal responsibility. The State would provide

this backstop as part of the Option 1 attainment strategy, maintaining the primary

attainment emission targets without modification at this time. As part of the process of

developing the long-term measures, we will continue to use every possible means to

press our federal counterparts to act where the State and local air agencies cannot. 
39

IV. 2003 PARTICULATE MATTER SIP FOR SOUTH COAST AIR BASIN

The 2003 Plan includes a PM10 emission inventory, attainment demonstration, control

strategy, and other elements required by the CAA. If approved by ARB and U.S. EPA,

the PM10 element of 2003 Plan would replace the existing 1997 PM10 Plan. The

following sections provide ARB staff's analysis of the PM10 element of the 2003 Plan. 

A. Emission Inventory

PM10 is a complex mixture of primary or directly emitted particles (from soot and

geologic dust), and secondary particles formed in the atmosphere from PM10

precursors such as NOx, sulfur dioxides (SOx), and VOC. VOC acts as a catalyst in the

atmosphere, reacting with NOx to form nitric acid, and with SOx to form sulfuric acid.

Both nitric acid and sulfuric acid react with ammonia to form ammonium nitrate or

ammonium sulfate particles. 

The largest source of direct PM10 emissions is paved and unpaved road dust entrained

to the atmosphere during vehicle travel. Construction and demolition activities, waste

burning and disposal, and windblown dust are also major contributors to direct PM10.

Entrained road dust and PM10 from construction activities will decline through 2006 due

to adopted local controls, but are projected to increase thereafter due to increased

vehicle travel and growth in the region.

The largest ammonia sources in the Basin include livestock waste, fertilizers, and

domestic sources. About 50 percent of SOx emissions in the Basin are emitted from

commercial ships and boats, while facilities in the District's RECLAIM program

contribute another 20 percent. Table IV-1 shows trends in PM10 and PM10 precursor

emissions between the 1995 base year for the PM10 Plan and the 2006 attainment

year. 
40

Table IV-1

PM10 and PM10 Precursor Emission Trends

(South Coast Air Basin, Annual Average, tons per day)

Source Category PM10 NOx SOx VOC

1995 2006 1995 2006 1995 2006 1995 2006

Paved and Unpaved 

 Road Dust

180 143 0 0 0 0 0 0

Construction 

 and Demolition 29 44 0 0 0 0 0 0

Fugitive 

 Windblown Dust 23 14 0 0 0 0 0 0

Other Stationary 

 And Area-wide 43 51 164 95 36 19 427 292

On-Road 

 Mobile Sources 19 20 869 563 17 5 623 266

Off-Road 

 Vehicles/Equip. 20 21 311 292 29 36 257 139

TOTAL 314 293 1344 950 82 60 1307 697

The relative contribution of precursor and direct PM10 to ambient PM10 levels varies

throughout the South Coast, based upon the local geography, human activities, and

other factors. In the eastern part of the Basin, direct PM10 from windblown dust,

construction, and entrained road dust are the greatest contributors to ambient PM10. In

the more urbanized western part of the Basin, industrial activities, road dust, and vehicle

exhaust play a greater role in PM10 concentrations. Figure IV-1 shows the relative

contribution of direct and secondary PM10 emissions to measured PM10 concentrations

at key monitoring sites in the Basin.

1. Inventory Updates

The 2003 Plan updates the 1997 PM10 Plan inventory for several sources of PM10 and

PM10 precursors. The 2003 Plan utilizes EMFAC2002 rather than EMFAC7G to

generate on-road mobile source emissions, and the OFF-ROAD model to generate

most of the off-road emission inventory (See Section III-A, above). Methodologies for

estimating stationary and area-wide source emissions of PM10 and PM10 precursors

have also been updated using the latest available information. Key inventory

methodology updates to the PM10 element of the 2003 Plan are described below.
41

Figure IV-1

Relative Contribution of Primary PM10 and Precursors to Measured Annual

Average PM10 Concentrations

(1995, μg/m3 in South Coast Air Basin)

0

20

40

60

80

Anaheim Diamond Bar Fontana Los Angleles Rubidoux

Primary PM10 Nitrate Ammonium Sulfate

Fugitive Dust PM10 emissions estimates for paved and unpaved road dust,

construction operations, windblown dust, and farming operations have all declined due

to updated emission factors and activity data. The updated emission factors incorporate

information that is more specific and representative of the Southern California region.

For example, large decreases in the windblown dust category are due to an updated

methodology that now uses climate, wind speed, and soil data specific to Southern

California. Although estimates of vehicle miles traveled have increased slightly since

the 1997 PM10 Plan, the overall entrained paved road dust emissions have declined.

This is due to better allocation of traffic on each road type and emission factor

refinements, which lowered the effective overall emissions per mile traveled. Similar

updates, using the most current emission factor and activity information, were also

applied to the unpaved road dust, construction, and farming operation categories. 

Residential Wood Combustion The 2003 Plan utilizes the District's methodology to

estimate emissions from residential wood combustion. Residential wood combustion

includes emissions from both fireplaces used for primary home heating and those used

for aesthetic purposes. The South Coast methodology assumes that 50 pounds of

wood is burned by 70 to 90 percent of fireplaces for aesthetic purposes, while the

remaining 10 to 30 percent of fireplaces burn 800 pounds of wood per year for primary

home heating. With this methodology, wood-burning fireplaces in the Basin were

estimated to emit 3.6 tpd PM10 in 1997. ARB staff believes the District PM10

emissions estimate for fireplaces may be low. However, additional survey data is

needed to more fully understand the extent of residential wood-burning in the Basin.

The 2003 Plan indicates the District will work with ARB and other stakeholders to

reevaluate the inventory, if necessary, prior to adopting a control measure for this

source category. 

61.0 69.0

43.5 42.8 46.0
42

Ammonia Sources The District conducted a comprehensive revision to the ammonia

inventory, based on a report by AeroVironment Environmental Services Inc. (AVES),

which updated emission levels and activity factors for ammonia sources in the Basin.1

Relative to the 1997/99 SIP, overall ammonia emission estimates for the Basin

remained relatively unchanged. Estimated emissions from dairy cows increased due to

higher population estimates and emission factors, while the inventory decreased for

poultry (lower emission factor) and horses (lower population estimates and emission

factor). Estimates for domestic ammonia sources have also risen. ARB staff concurs

with this inventory methodology update and believes these emission updates reflect the

latest scientific data.

Composting Operations As part of the overall ammonia emissions inventory update,

ammonia emissions from composting operations were quantified for the first time. VOC

emissions from this source are estimated to be 6.8 tpd in the Basin. 

B. Attainment Demonstration

The 2003 Plan includes two modeling approaches to demonstrate attainment of the 24-

hour and annual average PM10 standards. The District uses a linear rollback method to

model the 24-hour average, and the Urban Airshed Model for Aerosols - Long-Term

(UAMAERO-LT) to model the annual average. UAMAERO-LT is based on the annual

average PM10 and PM10 precursor inventory, with adjustments made for weekly and

monthly variation. Both the 24-hour and annual average modeling approaches use data

from the 1995 PM10 Technical Enhancement Program (PTEP). This intensive

monitoring program provides the most robust data set for modeling in the South Coast

in terms of sampling frequency and information about the chemical components of

PM10. The five PTEP monitoring sites were operated at Anaheim, Diamond Bar, Los

Angeles, Fontana, and Rubidoux.

24-Hour Standard The plan demonstrates attainment of the 24-hour standard at the

five PTEP intensive monitoring sites for an exceedance of the PM10 24-hour standard

that occurred in November 1995. This data reflects the highest PM10 concentrations

observed in the air basin over the last eight years that are not windblown dust events.

The District further notes that since 1997, the only 24-hour PM10 exceedances that

have occurred have been associated with high winds. The linear rollback method is

considered preferable to UAMAERO-LT for demonstrating attainment of the short-term

24-hour standard due to difficulty in adequately representing day-specific spatial

variability in emissions, particularly fugitive dust emission categories. The linear

rollback approach apportions the PM10 concentration at a monitoring site into its

chemical components. The rollback method assumes that future PM10 levels above

background concentrations will decrease in proportion to projected emission reductions

associated with each chemical component. With projected controls, PM10

 

1 1997 Gridded Ammonia Emission Inventory Update for the South Coast Air Basin, AeroVironment

Environmental Services Inc., August 2001.
43

concentrations in 2006 are predicted to be below the level of the 24-hour standard at all

five PTEP monitoring sites. 

Annual Average Standard While the 1997 PM10 Plan modeling focused on

demonstrating attainment of the annual average at the five PTEP intensive monitoring

sites, the 2003 Plan evaluates attainment at each modeling grid cell basin-wide.

However, data from the five PTEP monitoring sites is used to evaluate the performance

of the model. The District established model performance goals and compared model

predictions by chemical component to the ambient data at each of the five PTEP

monitoring sites. Overall, the performance of UAMAERO-LT averaged over the five

monitoring sites is within or near the performance goals. With projected controls, PM10

concentrations in 2006 are predicted to be below the level of the annual average

standard at all five PTEP monitoring sites. Table IV-2 shows the projected

concentrations at each of the five sites for comparison to the federal 24-hour standard

of 150 μg/m3 and the federal annual average standard of 50 μg/m3. 

Table IV-2

Projected 2006 24-Hour and Annual Average PM10 Concentrations 

with 2003 PM10 SIP Controls

(South Coast Air Basin)

Site

Projected 24-Hour

Concentration

(μg/m3)

Projected Annual

Average

Concentration

(μg/m3)

Anaheim 137.5 49.9

Diamond Bar 123.3 39.9

Fontana 128.4 47.2

Los Angeles 116.7 38.0

Rubidoux 150 47.6

The UAMAERO-LT model also indicates that, with projected controls, all but thirteen

grid cells attain the federal annual average PM10 standard in 2006. These "hot spot"

grid cells are located in Los Angeles and Orange counties in areas that experience

heavy traffic and are impacted by paved road dust, as well as in parts of San

Bernardino and Riverside Counties heavily impacted by fugitive windblown dust,

construction dust, and paved road dust. The District utilizes a weight-of-evidence

analysis to demonstrate that the annual average PM10 standard will be attained in

these thirteen grid cells and throughout the Basin. Citing studies suggesting paved road

dust emissions do not continue increasing once a certain vehicle traffic threshold has

been reached, the Plan indicates that these emissions are likely to be overstated by a

factor of two in Los Angeles and Orange Counties. The District also presents evidence

that unpaved road dust, fugitive windblown dust and construction dust emissions are

likely misallocated, and that these factors are likely to directly impact the thirteen "hot
44

spot" grid cells. ARB staff has examined the weight-of-evidence analysis for the annual

average PM10 attainment demonstration and has found it to be credible.

C. Control Strategy

The PM10 control strategy in the 2003 Plan benefits from about 400 tpd NOx, 600 tpd

VOC, and 20 tpd PM10 emission reductions between 1995 and 2006 from adopted

local, State, and federal measures. To support the PM10 attainment demonstration, the

District will adopt additional measures achieving 1.02 tpd PM10, 2.1 tpd SOx, and 10.6

tpd ammonia by 2006. The District will achieve additional PM10 and ammonia emission

reductions by 2010, to help mitigate projected increases in paved road dust and

construction operation emissions. 

1. District Control Measures

Table IV-3 shows emission reductions for the new control measures which address

PM10, SOx, and ammonia (NH3). An additional 5.4 tpd VOC emission reductions will

be achieved by 2006 from new District ozone control measures described in

Section III.C.1.

CMB-07: Refinery Flares District Rule 1118, adopted in 1998, requires petroleum

refinery operators to monitor, record, and report data on gas flaring operations.

CMB-07 would require a District evaluation of this data to determine the source and

extent of emissions and, if the data indicates emissions are significant, implementation

of controls to reduce SOx. Potential control options include physical modifications,

implementation of flaring minimization plans, and improvements to operation and

maintenance procedures to reduce emergency venting of liquids or gases. See

Section III.C.1 for additional discussion.

CMB-09: Petroleum Refinery Fluid Catalytic Cracking Units Six petroleum

refineries in the Basin operate fluid catalytic cracking units to convert heavy oils into

gasoline and lighter petroleum products. District Proposed Rule 1105.1 - Reduction of

PM10 and Ammonia Emissions from Fluid Catalytic Cracking Units, scheduled to be

considered for adoption by the District Governing Board on September 5, 2003, would

implement control measure CMB-09. The proposed rule establishes emission limits for

filterable PM10 and ammonia and requires periodic source testing to ensure

compliance. 

WST-01: Livestock Waste See Section III.C.1.

WST-02: Composting See Section III.C.1.
45

Table IV-3

Additional 2003 Plan District Control Measures 

(South Coast Air Basin, 2006 annual average emission reductions)

Measure PM10 SOx NH3

Remaining 1997/1999 SIP Control Measures

CMB-07: Refinery Flares (SOx) -- 2.1 --

CMB-09: Petroleum Refinery Fluid Catalytic

Cracking Units (PM10/NH3)* 0.0 -- 0.0

WST-01: Livestock Waste (NH3) -- -- 8.7

WST-02: Composting (NH3) -- -- 1.9

PRC-03: Restaurant Operations (PM10) 0.2 -- --

New Control Measures

BCM-07: Further PM10 Reductions from Fugitive

Dust Sources (PM10) tbd -- --

BCM-08: Further Emission Reductions from

Aggregate and Cement Plant Manufacturing

Operations (PM10)

0.6 -- --

MSC-04: Miscellaneous Ammonia Sources (NH3) -- -- tbd

MSC-06: Wood-Burning Fireplaces and Wood

Stoves (PM10) tbd -- --

TCB-01: Transportation Conformity Backstop

Measure (PM10)*

0.0 -- --

TOTAL REDUCTIONS IN 2006 1.02** 2.1 10.6

* Measures intended to achieve post-2006 emission reductions.

** This total reflects 0.8 tpd PM10 reductions intended to be achieved from PRC-03 and BCM-08, and

0.22 tpd additional PM10 reductions to be achieved through a combination of the above control

strategies.

PRC-03: Restaurant Operations This control measure would target under-fired

charbroilers, which are responsible for 84 percent of PM10 emissions and 71 percent of

VOC emissions from all restaurant operations. The District has a contract with the

University of California, College of Engineering, Center for Environmental Research and

Technology (CE-CERT) to examine potential cost-effective controls for this source

category. Potential emission reduction strategies include use of a cyclonic air scrubbing

device, which employs water and filters to reduce PM10, and replacement of under-fired

charbroilers with a SmokelessTM Broiler. The Plan indicates PRC-03 targets PM10

emission reductions only, due to the projected high cost of VOC reduction technologies

BCM-07: Further Emission Reductions from Fugitive Dust Sources Section

189(b)(1)(B) of the Act requires the District to implement BACM for major sources of

fugitive dust. Upon local adoption, the 1997 PM10 Plan included fugitive dust

regulations at least as stringent as controls achieved in other areas or included in other

PM10 SIPs. However, other areas have since developed and adopted controls more

stringent than District requirements. BCM-07 would require the District to review its
46

BACM requirements and consider updates to achieve additional fugitive dust emission

reductions. Potential control strategies include watering of dust sources, chemical

stabilization, paving, and track-out controls for roads, and revegetation of vacant lands.

ARB encourages the District evaluate strategies adopted in Las Vegas, Nevada and

Mariposa County (Phoenix), Arizona during its BACM analysis.

BCM-08: Further Emission Reductions from Aggregate and Cement Plant

Manufacturing Operations Aggregate plants produce sand, gravel, and crushed stone

used in the construction of housing, commercial buildings, highways, bridges, airports,

and other projects. PM10 emissions occur from quarrying, crushing, and grinding

operations at aggregate plants, as well as from wind-blown storage piles, and unpaved

haul road traffic. Additional PM10 emissions can occur during the cement kiln process

which processes raw materials such as limestone and silica into cement. While existing

rules control these sources based on visible emissions and other criteria, additional

controls may be feasible and cost-effective. Potential controls for aggregate plants

include application of water prior to material extraction, application of chemical dust

suppressants or ground cover to disturbed areas, chemical stabilization or paving of

internal haul roads, and other strategies. Potential controls for cement kilns include

electrostatic precipitators, high efficient baghouses, and improved maintenance

practices.

MSC-04: Miscellaneous Ammonia Sources This measure would reevaluate potential

control strategies for ammonia sources, based upon the updated ammonia inventory.

Potential control strategies include expansion of rules to reduce ammonia emissions

from livestock waste and composting, and changing fertilizer formulation and application

procedures. 

MSC-06: Wood-Burning Fireplaces and Wood Stoves The South Coast does not

currently regulate residential wood burning. This measure identifies several potential

strategies for evaluation and possible implementation to reduce PM10 emissions from

new and existing residential fireplaces and wood stoves. U.S EPA has particulate

emission standards for wood stoves and fireplace inserts that are manufactured and

sold in the U.S. and ARB has developed a suggested control strategy for emissions

from residential wood combustion. 

Several air districts have also developed residential wood burning rules. These rules

range from programs to discourage burning on days with poor air quality, to mandatory

installation of lower-emitting wood stoves, to limiting the installation of wood burning

devices in new buildings.

In July 2003, the San Joaquin Valley District amended its Rule 4901 - Wood Burning

Fireplaces and Wood Heaters, to:

 require existing wood stoves be U.S. EPA-certified, removed from the residence, or

made inoperable upon sale of a residence;

 set a limit on the number of wood burning devices allowed in new subdivisions; and
47

 prohibit burning in residential wood fireplaces on days with unhealthy air quality (as

indicated by a U.S. EPA Air Quality Index > 150).

ARB staff encourages the District to consider strategies for residential wood burning as

effective as those in the San Joaquin Valley in developing MSC-06.

TCB-01: Transportation Conformity Backstop Measure The attainment year

emission budgets for PM10 also serve as the budgets for future years to ensure that

emissions from the transportation sector are consistent with continued attainment of the

standard. However, by 2020 and 2030 increased vehicle travel on paved and unpaved

roads may result in PM10 emissions from the transportation sector which exceed then

2006 budget. The District has committed to achieve additional emission reductions of

up to 9 and 16 tons per day of PM10 by 2020 and 2030, respectively, if necessary to

assist SCAG in its future year conformity determinations. These reductions could be

achieved through dust controls, vehicle travel reduction strategies, or other local

measures. 

The District identified ARB as an implementing agency for this measure. ARB staff is

not proposing a State commitment for this measure. However, staff believes it is

appropriate for PM10 reductions from regulations adopted by the Board be creditable in

transportation conformity determinations.

Contingency Measures The 2003 Plan includes the following contingency measures

for PM10:

 CTY-01: Accelerated Implementation of Control Measures -- See Section III.C.1. 

 CTY-14: Control of Emissions from Miscellaneous Sources -- This contingency

measure would reduce PM10 emissions from weed abatement operations. Potential

controls include requiring mowing instead of discing (which churns up the soil), weed

abatement vehicle speed limits, limiting weed abatement to morning hours when

winds are lower, and requiring pre-treatment of the site with a watering truck.

Low Sulfur Diesel Fuel In September 2000, the District adopted a rule prohibiting the

use of diesel fuel with a sulfur content greater than 15 ppm by January 1, 2005, unless

ARB adopted a similar rule to be implemented by June 1, 2006. In July 2003, the Board

adopted a 15 ppm low-sulfur diesel fuel regulation. The rule will enable the use of

advanced exhaust aftertreatment devices, and achieve significant decreases in diesel

particulate matter, NOx, and SOx emissions statewide. The ARB limits will achieve

2006 emission reductions in the South Coast Air Basin beyond those from the District

rule. The statewide regulation will also reduce emissions from trucks and off-road

equipment that are fueled in other areas of California but travel through the Basin. 

District staff has expressed concerns that the implementation schedule for the ARB

regulation (2006 rather than 2005 under the District rule) would leave a shortfall in the

progress and attainment demonstrations for the PM10 SIP element of the 2003 Plan. 
48

The District Board Resolution adopting the 2003 Plan requests that ARB offset 6 tpd

SOx and PM10 emission reductions that the 2003 Plan had assumed would occur by

2006. This reduction estimate seems to reflect the projected benefits described in the

September 2000 South Coast staff report on the District's proposed 15 ppm low sulfur

diesel rule. 1 However, the benefits credited in the 2003 Plan for low-sulfur fuel use are

more modest. The 2003 Plan assumes 15 ppm sulfur diesel fuel use for off-road

sources beginning on January 1, 2005, but does not assume 15 ppm sulfur diesel for

on-road sources until January 1, 2007, six months after the ARB (and national)

implementation date. The on-road benefits of the low-sulfur fuel rule far exceed the offroad benefits in 2006. 

We conclude that the regulation adopted by the Board will achieve the emission

reductions credited in the 2003 PM10 SIP for progress and attainment. There is no

shortfall.

2. Structure of District Commitment

The 2003 Plan includes an enforceable commitment to bring each District PM10 control

measure to the District Board and meet an emissions reduction target in a certain

timeframe. The District Board does not commit to adopt each specific control measure

or achieve the anticipated emission reductions from each measure. However, if a plan

measure does not achieve the anticipated emission reductions, the District must adopt

and implement alternate strategies to fulfill the overall Plan commitment on time. The

plan commits the District to achieve 2.2 tpd PM10 emission reductions from measures

to be adopted in 2003 and 2004, with the reductions to be achieved between 2005 and

2010. The 2003 Plan also commits the District to adopt measures achieving 2.1 tpd

SOx reductions by 2004, with implementation by 2005. Section III describes the

District's enforceable commitment to reduce NOx and VOC emissions. While the

District does not explicitly define a SIP commitment for ammonia reductions, measures

achieving 10.8 tpd ammonia emission reductions by 2006 were included in the PM10

attainment demonstration and are therefore enforceable.

 

1 Staff Report - Proposed Amended Rule 431.2: Sulfur Content of Liquid Fuels, South Coast Air Quality

Management District, September 6, 2000.
49

V. 2003 CARBON MONOXIDE SIP FOR SOUTH COAST AIR BASIN

The CAA requires an area not exceed the federal carbon monoxide standard more than

once in a two-year period. The Basin has achieved this air quality milestone by

recording no violations of the federal carbon monoxide standard in 2001 and only one

violation in 2002. This occurred during stagnant air conditions on January 8, 2002,

when the Lynnwood monitoring station near downtown Los Angeles recorded an eighthour carbon monoxide concentration of 10.1 ppb, exceeding the standard of 9.5 ppb. 

Although the South Coast Air Basin meets the criteria for attainment, the District has not

yet chosen to request redesignation and prepare a maintenance plan. Meanwhile, the

2003 Plan revises the existing attainment demonstration. 

A. Emission Inventory

The 2003 Plan uses EMFAC2002 to generate the on-road mobile source carbon

monoxide inventory. In 2003, cars, trucks, and other on-road mobile sources emitted

two-thirds of the total wintertime carbon monoxide emissions in the Basin. Off-road

equipment such as lawn mowers, forklifts and generators are the primary off-road

mobile source of carbon monoxide, while residential fuel combustion and waste burning

and disposal contribute the majority of carbon monoxide from stationary and area-wide

sources. ARB motor vehicle regulations have helped reduce overall carbon monoxide

emissions by almost sixty percent between 1990 and 2003. Emissions are projected to

continue declining significantly due to fleet turnover. Figure V-1 shows carbon

monoxide trends for the Basin by major source category from 1990 to 2020.

Figure V-1

Carbon Monoxide Emission Trends 

(South Coast Air Basin, Winter planning inventory, tons per day)

B. Attainment Demonstration

0

2000

4000

6000

8000

10000

12000

1990 1995 2000 2005 2010 2015 2020

On-road

light-duty vehicles

On-road heavy-duty vehicles

Off-road vehicles & equipment

Stationary & area-wide sources
50

B. Attainment Demonstration

In 2003, South Coast Air Basin air quality met the criteria specified in the CAA for

attainment of the federal CO standard. The 2003 Plan also uses an October 31-

November 1, 1997 episode day and the CAMx air quality model to project attainment of

the federal carbon monoxide standard beginning in 2003. This episode had an eighthour maximum carbon monoxide concentration of 17 ppb, which was the highest

observed carbon monoxide concentration since 1996. The projected maximum eighthour carbon monoxide concentration in the Basin in 2002 was 10.0 ppb, similar to the

observed concentration at Lynnwood during the January 8, 2002 exceedance. The

maximum eight-hour carbon monoxide concentration for 2003 through 2005 is projected

through linear rollback, whereby the projected CO concentration is reduced in

proportion to projected CO emission reductions. With this approach, the maximum

predicted eight-hour CO concentration is 9.4 ppm in 2003, 8.9 ppm in 2004, and 8.4

ppm in 2005. Continued CO emission reductions should ensure the region remains in

attainment of the federal CO standard after 2005.

C. Control Strategy

The District assigned a contingency measure to ARB and U.S. EPA -- CTY-04:

Enhanced Oxygenated Fuels Content -- to reduce carbon monoxide emissions by

increasing the oxygen content of gasoline in the winter. ARB staff is not proposing a

State commitment for this measure. ARB staff believes the increasing CO reductions

that will be achieved with adopted motor vehicle and equipment controls as the fleet

turns over to cleaner engines provide sufficient contingency for the 2003 CO SIP. 

 

Regardless of authority, we don’t think the District’s proposal would be advisable. While

increasing fuel oxygen content may tend to decrease CO emissions, it also tends to

increase NOx emissions. 
51

VI. 2003 NITROGEN DIOXIDE SIP FOR THE SOUTH COAST

The South Coast Air Basin was redesignated to attainment for the federal nitrogen

dioxide (NO2) standard on July 24, 1998.1 The 2003 Plan revises the approved 1997

NO2 Maintenance Plan with updated conformity budgets based upon the latest

emission inventory and planning assumptions. The 1997 NO2 maintenance plan

demonstrated continued maintenance of the standard through 2010. The 2003 Plan

demonstrates that NOx emissions will continue to decline through 2010 as a result of

adopted controls, and that the rate of decline will accelerate after 2006 if the proposed

ozone strategy is implemented. 

 

1 Federal Register, July 24, 1998, Volume 68, No. 142.
52

VII. 2003 PARTICULATE MATTER SIP FOR COACHELLA VALLEY 

The 2003 Coachella Valley PM10 Plan updates the region's emission inventory and

PM10 attainment demonstration. 

A. 2003 Coachella Valley PM10 Plan

On August 1, 2003, the District Governing Board adopted the 2003 Coachella Valley

PM10 Plan, which updates the 2002 Coachella Valley PM10 Plan emission inventory,

attainment demonstration, and conformity emission budgets. The 2003 Coachella

Valley PM10 Plan does not alter the 2002 plan control strategy. 

1. Emission Inventory

The 2003 Coachella Valley PM10 Plan updates the on-road mobile source inventory

used in the 2002 Coachella Valley PM10 Plan with an EMFAC2002-based inventory.

The 2003 Coachella Valley PM10 Plan also updates the fugitive dust inventory based

on the methodology improvements described in Section IV. As a result, windblown dust

estimates for the Coachella Valley have decreased, from about 31 tpd to about 9 tpd in

the year 2000. Paved and unpaved road dust, and PM10 from construction operations

are also about 4 tpd lower.

2. Attainment Demonstration

The Coachella Valley attainment demonstration utilizes a linear rollback approach to

model attainment of the 24-hour standard and UAMAERO-LT for the annual average

PM10 standard. The 2003 Coachella Valley PM10 Plan utilizes a 1995 base year, an

updated emission inventory, and the benefits of the 2002 Coachella Valley PM10 Plan

controls, to demonstrate attainment by 2006. Table VII-1 includes a summary of the

contribution of various PM10 constituents to PM10 levels in 1995, and in 2006 with and

without new plan controls.
53

Table VII-1

Base-Year and 2006 Modeled PM10 Concentrations 

 (Coachella Valley, μg/m3)

1995 Design

Value

2006 Without

New Controls

2006 With 

New Controls

Source Category

Annual 24-Hour Annual 24-Hour Annual 24-Hour

Background 3.0 3.0 3.0 3.0 3.0 3.0

Transport 8.8 14.2 6.4 14.2 6.3 14.2

Mobile Sources 1.3 3.6 1.3 3.8 1.3 3.8

Construction Dust 0.8 2.7 5.0 18.4 4.5 16.6

Paved Road Dust 4.4 15.8 4.6 16.7 3.6 13.2

Unpaved Road Dust 3.2 11.6 3.2 11.6 2.8 10.1

Agriculture 0.6 2.2 0.5 1.9 0.5 1.9

Windblown Dust 18.3 67.7 18.2 66.7 18.2 66.7

Vegetation Burning 5.9 10.4 4.9 8.7 4.9 8.7

Other 3.4 2.8 4.4 3.6 4.4 3.6

TOTAL 49.7 134.0 51.5 148.5 49.6 141.6

Federal annual standard is 50 μg/m3; 24-hour standard is 150 μg/m3
54

IX. ON-ROAD MOTOR VEHICLE EMISSION BUDGETS

The 2003 Plan sets forth the strategy for achieving the federal one-hour ozone, PM10,

and CO standards, and maintaining the federal NO2 standard. For on-road mobile

sources, Section 176(c) of the CAA requires that transportation plans and programs do

not cause or contribute to any new violation of a standard, increase the frequency or

severity of any existing violation, or delay the timely attainment of the air quality

standards. In other words, emissions from on-road mobile sources must "conform" to

the attainment demonstration contained in the SIP.

U.S. EPA's transportation conformity rule, found in 40 CFR parts 51 and 93, details the

requirements for establishing motor vehicle emissions budgets in SIPs for the purpose

of ensuring the conformity of transportation plans and programs with the SIP attainment

and progress demonstration. The on-road motor vehicle emissions budgets act as a

"ceiling" for future on-road mobile source emissions. 

Emissions resulting from regional transportation plans and projects must fit within the

budgets established in the SIP. A positive conformity finding is required for federal

approval and funding of transportation improvements. 

The on-road motor vehicle emissions estimates for the 2003 Plan were developed using

ARB's on-road mobile source emission factor model, EMFAC2002, in conjunction with

the most recent motor vehicle activity data from SCAG. Emissions forecasts were

generated for the summer, winter, and annual average planning inventory using

EMFAC2002 for each milestone and attainment or maintenance year. The model

outputs were then adjusted to account for existing emission reduction programs not

reflected in the model. These include: Smog Check improvements in place as of Fall

2002; the benefits of the District’s employer rideshare program, and the emission

reductions attributable to SCAG's Regional Transportation Plan. 

The ozone emissions budgets for VOC and NOx are derived from the adjusted summer

planning inventory and the 2010 reductions from near-term defined measures. The

PM10 emissions budgets for PM10 and the PM10 precursors VOC and NOx are derived

from the adjusted annual average planning inventory. The CO and NO2 emissions

budgets for CO and NOx, respectively, are both derived from the adjusted winter

planning inventory. The District and ARB request that U.S. EPA replace the existing

emission budgets with the 2003 Plan budgets once the new budgets are determined to

be adequate. Tables VIII-1 through VIII-4 include the 2003 Plan motor vehicle emission

budgets for ozone, PM10, carbon monoxide, and nitrogen dioxide for the South Coast

Air Basin. Table VIII-5 shows the PM10 budgets for Coachella Valley.
55

Table VIII-1

Ozone Budgets -- South Coast Air Basin

(Summer planning, tons per day)

VOC 2005 2008 2010

Baseline EMFAC2002 267.5 233.6 208.6

SCAG TCM Benefits 0.0 -13.7 -15.7

Adjusted EMFAC2002 267.5 219.9 192.8

District Rule 2202 -2.7 -2.1 -1.7

I/M Improvements -2.7 -2.2 -1.9

Adjusted Inventory 262.1 215.6 189.2

New Defined State Measures 0.0 0.0 -34.2

New Local Measures 0.0 0.0 0.0

Mobile Source Emission Budgets* 263 216 156

NOx 2005 2008 2010

Baseline EMFAC2002 522.9 474.9 413.9

SCAG TCM Benefits 0.0 -5.5 -7.8

Adjusted EMFAC2002 522.9 469.4 406.0

District Rule 2202 -2.9 -2.3 -1.8

I/M Improvements -4.2 -3.7 -3.4

Adjusted Inventory 545.8 463.4 400.9

New Defined State Measures 0.0 0.0 -37.4

New Local Measures 0.0 0.0 0.0

Mobile Source Emission Budgets* 546 464 364

* Rounded up to the nearest ton.

The ozone budgets for the South Coast Air Basin reflect the reductions from adopted

measures and the near-term defined measures. When the strategies to achieve the

needed long-term emission reductions are identified, the District, SCAG, and ARB have

agreed to modify the budgets to incorporate any additional reductions expected from

on-road motor vehicles. This approach is consistent with U.S. EPA's transportation

conformity rule. 
56

Table VIII-2

PM10 Budgets-- South Coast Air Basin

(Annual average, tons per day)

VOC 2003 2006

Baseline EMFAC2002 315.8 363.8

SCAG TCM Benefits 0.0 -8.5

Adjusted EMFAC2002 315.8 255.3

District Rule 2202 -3.5 -2.6

I/M Improvements -1.9 -2.6

Adjusted Inventory 310.4 250.1

New Defined State Measures 0.0 0.0

New Local Measures 0.0 0.0

Mobile Source Emission Budgets* 311 251

NOx 2003 2006

Baseline EMFAC2002 641.8 562.9

SCAG TCM Benefits 0.0 -7.0

Adjusted EMFAC2002 641.8 555.9

District Rule 2202 -4.1 -2.9

I/M Improvements -2.8 -4.1

Adjusted Inventory 634.9 548.9

New Defined State Measures 0.0 0.0

New Local Measures 0.0 0.0

Mobile Source Emission Budgets* 635 549

PM10 2003 2006

Baseline EMFAC2002 18.9 19.9

SCAG TCM Benefits 0.0 -0.6

Adjusted EMFAC2002 18.9 19.3

District Rule 2202 -0.1 -0.1

I/M Improvements 0.0 0.0

Reentrained Road Dust (paved) 136.8 134.9

Reentrained Road Dust (unpaved) 9.7 8.7

Road Construction Dust 2.2 2.2

Adjusted Inventory 167.6 165.0

New Defined State Measures 0.0 0.0

New Local Measures 0.0 0.0

Mobile Source Emission Budgets* 168 166

* Rounded up to the nearest ton.
57

Table VIII-3

Carbon Monoxide Budget-- South Coast Air Basin

(Winter planning, tons per day)

CO 2002

Baseline EMFAC2002 3402.4

SCAG TCM Benefits 0.0

Adjusted EMFAC2002 3402.4

District Rule 2202 -41.9

I/M Improvements 0.0

Adjusted Inventory 3360.5

New Defined State Measures 0.0

New Local Measures 0.0

Mobile Source Emission Budgets* 3361

*Rounded up to the nearest ton.

Table VIII-4

Nitrogen Dioxide Budgets-- South Coast Air Basin

(Winter planning, tons per day)

NOx 2003

Baseline EMFAC2002 692.3

SCAG TCM Benefits 0.0

Adjusted EMFAC2002 692.3

District Rule 2202 -4.4

I/M Improvements -2.8

Adjusted Inventory 685.0

New Defined State Measures 0.0

New Local Measures 0.0

Mobile Source Emission Budgets* 686

* Rounded up to the nearest ton.
58

Table VIII-5

PM10 Budgets-- Coachella Valley

(Annual average, tons per day)

PM10 2003 2006

Baseline EMFAC2002 0.39 0.42

Reentrained Road Dust (paved) 7.64 5.80

Reentrained Road Dust (unpaved) 4.23 3.68

Road Construction Dust 0.06 0.06

Additional Margin (based on modeling) 0.0 0.97*

Mobile Source Emission Budgets 12.3** 10.9***

* Additional margin based on over-attainment of the PM10 standard.

** Represents remaining emissions at the end of 2003.

*** Non-transportation emissions represent an additional 19.1 tpd, 0.37 tpd of

which are from off-road sources. Non-transportation emissions are shown in case

a future SIP revision provides for budget trading between transportation and

non-transportation sectors.
59

IX. STAFF RECOMMENDATIONS

The 2003 Plan reflects significant progress towards cleaner air for the residents of the

South Coast Air Basin and Coachella Valley. Approval of the SIP elements will

incorporate existing measures into the baseline and make enforceable the new

commitments for actions to achieve the federal one-hour ozone standard by 2010 in the

South Coast Basin, and by 2007 in the Coachella Valley. Approval of the SIP will also

update the strategy to attain the federal PM10 standards in the Basin and in the

Coachella Valley by 2006. 

ARB staff recommends that the Board take the following actions and direct the

Executive Officer to submit these elements to U.S. EPA as revisions to the California

SIP:

 Contingent upon the Board’s approval of the Proposed State and Federal Strategy,

approve the ozone element of the 2003 Plan for the South Coast Air Basin intended

to attain the federal one-hour ozone standard, including the local control strategy,

emission inventories, attainment demonstration, and motor vehicle emission

budgets. The final State and Federal Strategy entirely replaces the draft State and

federal elements in the 2003 Plan. 

 Approve the PM10 element of the 2003 Plan for the South Coast Air Basin intended

to attain the federal 24-hour and annual standards for PM10, including the local

control strategy, emission inventories, attainment demonstration, and motor vehicle

emissions budgets.

 Approve the carbon monoxide element of the 2003 Plan for the South Coast Air

Basin intended to attain the federal eight-hour carbon monoxide standard, including

the local control strategy, emission inventories, attainment demonstration, and motor

vehicle emissions budgets.

 Approve the nitrogen dioxide element of the 2003 Plan for the South Coast Air Basin

intended to maintain the federal nitrogen dioxide standard, including emission

inventories and motor vehicle emissions budgets.

 Approve the 2003 PM10 Plan for the Coachella Valley intended to attain the federal

24-hour and annual PM10 standards, including the emission inventories, attainment

demonstration, and motor vehicle emissions budgets.