Staff Report

on

Proposed Revisions to the PM2.5 and Ozone 

State Implementation Plans for the South Coast Air Basin 

Release Date: January 11, 2013

Scheduled for Consideration: January 25, 2013

Air Resources Board

California Environmental Protection Agency
Electronic copies of this document can be found on ARB’s website at 

http://www.arb.ca.gov/planning/sip/sip.htm. Alternatively, paper copies may be 

obtained from the Public Information Office, Air Resources Board, 1001 I Street, 

Visitors and Environmental Services Center, 1st Floor, Sacramento, California 

95814, (916) 322-2990.

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

large print, audiocassette, or computer disk. Please contact ARB’s Disability 

Coordinator at (916) 323-4916 by voice or through the California Relay Services 

at 711, to place your request for disability services. If you are a person with 

limited English and would like to request interpreter services, please contact 

ARB’s Bilingual Manager at (916) 323-7053.

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

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

policies of the Air Resources Board, nor does a reference to trade names or 

commercial products constitute endorsement or recommendation for use.
Table of Contents

I. Introduction ........................................................................................................1

A. South Coast PM2.5 SIP .............................................................................2

B. South Coast Ozone SIP .............................................................................4

II. Implementing the 2007 SIP Strategy ................................................................5

A. Clean New and In-Use Heavy-Duty Trucks................................................7

B. Cleaner In-Use Off-Road Equipment .........................................................9

C. Passenger Cars .......................................................................................11

D. Reducing Emissions from Ocean-going Vessels......................................12

III. Control Strategy and Attainment Demonstrations..........................................13

A. 2007 SIP Emission Reduction Commitments...........................................14

B. Attainment Demonstrations for PM2.5 and Ozone ...................................15

C. Actions to Achieve Reductions from Advanced Technologies..................15

IV. Other Clean Air Act Planning Requirements .................................................17

A. Emission Inventory....................................................................................17

B. Contingency Measures .............................................................................18

C. Transportation Conformity Budgets ..........................................................19

D. Ozone VMT Offset Demonstration ............................................................19

E. Reasonably Available Control Measures Analysis ....................................19

F. Environmental Impacts..............................................................................20

V. Staff Recommendations .................................................................................21

APPENDICES

Appendix A: SCAQMD Submittal Letter to ARB

Appendix B: SCAQMD 2012 Board Resolution

Appendix C: Link to South Coast 2012 AQMP

Appendix D: Link to U.S. EPA Approval and Promulgation of Implementation 

Plans; California; 2007 South Coast PM2.5 Plan and 2007 State Strategy

Appendix E: Link to U.S. EPA Approval of Air Quality Implementation Plans; 

California; South Coast; Attainment Plan for 1997 8-Hour Ozone Standards
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1

I. Introduction 

The South Coast 2012 Air Quality Management Plan (AQMP) is a multi-pollutant 

strategy to improve the air quality in the South Coast. The 2012 AQMP amends 

the South Coast Air Quality Management District (District) State Implementation 

Plan (SIP) to address three health-based National Ambient Air Quality Standards 

(NAAQS or standards): the 24-hour PM2.5 standard, the 8-hour ozone standard, 

and the 1-hour ozone standard. 

Specifically, the 2012 AQMP: 

 Demonstrates attainment of the 24-hour PM2.5 standard of 35 

micrograms per cubic meter (ug/m3) by 2014.

 Identifies measures and actions to fulfill 8-hour ozone SIP commitments 

approved by U.S. EPA to achieve emission reductions from advanced 

technologies.

 Demonstrates attainment of the 1-hour ozone standard by 2022.

In 2011 and 2012, the U.S. Environmental Protection Agency (U.S. EPA)

approved South Coast SIP amendments for the annual average PM2.51and the 

8-hour ozone2standards, respectively, see Appendices D and E. The attainment

strategies were developed and adopted by the District and ARB and submitted to 

U.S. EPA in 2007 (2007 SIP). The approved strategies target NOx for ozone 

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

The strategies in the 2007 SIP achieve most of the reductions necessary for the 

South Coast Air Basin to meet the 24-hour PM2.5 standard by the attainment 

year of 2014. To achieve the additional reductions needed for attainment, the 

District is proposing enhanced control measures to reduce emissions from wood 

burning and open burning on days when high PM2.5 levels are expected, in 

addition to reductions from char-broiler and livestock measures.

U.S. EPA has approved commitments by the District and ARB to adopt measures 

and achieve emission reductions needed for ozone attainment, including 

commitments to achieve emission reductions from advanced technologies as 

provided by Clean Air Act (CAA), section 182(e)(5). Technology has long been 

key to the State’s air quality progress. The 2012 AQMP includes specific actions

for the South Coast District and ARB to develop advanced technologies to 

achieve emission reductions through regulations, incentives, and other

mechanisms to implement the federally approved commitments. 

 

1

76 FR 41562 (July 14, 2011)

2

77 FR 12674 (March 1, 2012)
2

The 2012 AQMP also includes a 1-hour ozone SIP revision with an attainment 

demonstration for 2022 that relies upon reductions from implementation of the 

2007 8-hour ozone SIP, along with new District 8-hour ozone measures. The

1-hour ozone attainment demonstration in the 2012 AQMP includes emission 

reductions to be achieved through the same advanced technology measures and 

actions identified for the purposes of compliance with the 8-hour ozone standard. 

Finally, the 2012 AQMP addresses other federal planning requirements including 

requirements for emissions inventories, contingency measures, transportation 

conformity budgets, VMT offset demonstrations, and Reasonably Available 

Control Measure analysis.

A. South Coast PM2.5 SIP

PM2.5 air quality in the South Coast air basin is steadily improving with 

attainment of both the annual and 24-hr PM2.5 standards projected by 2014. 

The SIP for the annual standard was approved by U.S. EPA in 2011. The 2012 

AQMP includes the required attainment demonstration for the 24-hour PM2.5 

standard of 35 ug/m3. 

The air quality trend from 2001 through 2011 shows sharp reductions in PM2.5 

concentrations over that ten-year period. The three year averages or design 

values, dropped from 76 ug/m3 to 38 ug/m3. Without additional controls, the air 

quality modeling in the AQMP shows attainment by 2019. With the new SIP 

measures, the modeling projects that the 2014 design value will be 34.3 ug/m3, 

advancing the attainment date from 2019 to 2014. 

All of the sites in the South Coast with the exception of Mira Loma meet the 

24-hour PM2.5 standard by 2014 with the current control program. The new 

measures are necessary to bring this last site into attainment by 2014. The 

PM2.5 attainment strategy is primarily focused on directly-emitted PM2.5 and 

NOx reductions that can be feasibility achieved by the attainment date of 2014.

The District’s new PM2.5 control measures include stationary source controls, 

episodic controls, technology assessments, and educational programs. The key 

measures will reduce directly-emitted PM2.5 are: 

 enhancing the residential wood burning curtailment program;

 enhancing open burning restrictions.

The air quality modeling done for the AQMP was performed according to 

U.S. EPA guidelines, producing the results needed to develop the attainment 

demonstration. The first modeling exercise demonstrated that the region would 

attain the standard by 2019 with implementation of current control programs. 

The next step was to focus on controls that would be most effective in reducing 
3

PM2.5 to accelerate attainment. This effort involves determining the relative 

value of PM2.5 precursor reductions. 

The modeling done for the federally approved South Coast SIP for the annual 

PM2.5 standard established a set of factors to relate regional precursor per ton 

reductions to PM2.5 air quality improvements. The modeling for the 2012 AQMP 

provided a similar set of factors. Directly emitted PM2.5 reductions were the 

most effective, about 15 times more effective than NOx. Reductions in SOx were 

about eight times more effective than NOx. The contribution of ammonia 

emissions is imbedded as a component of the SOx and NOx factors since 

ammonium nitrate and ammonium sulfate are the particles formed in the 

atmosphere and contribute to PM2.5 concentrations. The analysis showed that 

reductions in VOC are the least effective per ton reduction, about one-third the 

benefit of NOx reductions. 

Further attainment modeling was done to project a 2014 future year design value 

based on adopted control measures that will be implemented by 2014. The 

result was a predicted design value of 37.3 ug/m3 which fails to meet the federal 

standard. New SIP measures were then developed bringing the modeled design 

value for 2014 to below 35.4 ug/m3 which meets the federal standard. 

U.S. EPA’s modeling guidance recommends the use of corroborating evidence to 

support the SIP attainment demonstration. The weight of evidence 

demonstration in the AQMP includes discussions of PM2.5 levels, emission 

trends, and future year PM2.5 predictions. The PM2.5 trend shows about a 50 

percent decrease in PM2.5 concentrations between 2001 and 2011. The rate of 

improvement is just under four ug/m3 per year. If that trend is extended beyond 

2011, the projection suggests attainment in 2013. This is corroborative evidence 

to support the modeling projection of attainment by 2014. 

The AQMP weight of evidence discussion also shows the relationship between 

reductions in emissions of PM2.5 and NOx, and the downward trend in PM2.5 

concentrations. Between 2002 and 2008, NOx emissions declined 31 percent 

and directly emitted PM2.5 was reduced 19 percent. During this same 

timeframe, the 24-hour average PM2.5 concentrations declined 27 percent 

showing the effectiveness of current control strategies. 

Since the attainment demonstration need only show an attainment year 

concentration below 35.4 ug/m3, any measures leading to improvement in air 

quality beyond this level can serve to meet contingency measure requirements. 

The AQMP shows that with the new SIP measures, the 2014 design value is 

34.28 ug/m3 providing an excess air quality improvement of 1.2 ug/m3 which can 

be used for contingency purposes. 

The excess air quality improvements beyond those needed to demonstrate 

attainment are also expressed in terms of emission reductions. The AQMP 
4

includes a calculation showing that a portion of the new PM2.5 and NOx 

reductions are reserved for contingency purposes. 

B. South Coast Ozone SIP

Ozone air quality in the South Coast air basin is improving with attainment of 

both the 1-hour and 8-hour ozone standards projected by 2022 and 2023

respectively. The SIP for the 8-hour ozone standard was approved by U.S. EPA 

in 2011. While the 1-hour ozone standard was revoked once the more health 

protective 8-hour standard3 was adopted, U.S. EPA recently took action to 

require the submittal of an attainment demonstration for the 1-hour ozone

standard of 0.125 parts per million (ppm). The 2012 AQMP includes an 

attainment demonstration for the 1-hour ozone standard showing attainment by 

the deadline of 2022. 

South Coast ozone air quality continues to improve, with the number of days 

exceeding ozone standards dramatically reduced in portions of the basin. The 

number of exceedances is lowest in the coastal areas, increasing towards the 

Riverside and San Bernardino valleys and adjacent mountain areas. The highest 

concentrations are also declining as emissions are reduced throughout the air 

basin. The central San Bernardino mountains recorded the greatest number of 

exceedances of ozone standards, with 8 days over the 1-hour standard and 84 

days over the 8-hour standard. Peak 1-hour ozone concentrations are also much 

lower than a decade ago. The three-year average, or design value, used in 

1-hour ozone attainment demonstration is 0.142 ppm for 2011 compared to a 

design value of 0.170 ppm in 2001. 

The ozone portions of the 2012 AQMP share a common strategy to attain both 

the 1-hour and 8-hour ozone standards. The attainment deadlines are nearly 

aligned, with a 2022 deadline for the 1-hour standard and 2023 for the 8-hour 

standard. The amount of reductions needed is different, but substantial new 

emissions reductions are needed to meet both ozone standards in the same 

general timeframe. 

As in previous AQMPs, the strategy to reduce ozone is a dual NOx/VOC 

approach. While the strategy is more heavily weighted toward reducing NOx 

emissions, continuing VOC reductions remain important. The emphasis on NOx 

reductions is two-fold, one, because the science shows that generally in the 

South Coast NOx reductions currently provide greater benefit to reducing ozone, 

and two, because NOx is also a precursor for PM2.5. 

The ozone strategy in the 2012 AQMP includes near-term NOx and VOC 

measures that rely on currently available and feasible technologies. New District 

short-term measures in the AQMP include: 

 

3

62 FR 38856
5

 VOC reductions from coatings, solvents, adhesives, lubricants and fugitive

emissions;

 NOx reductions from RECLAIM facilities, commercial heating and biogas 

Flares.

However, reductions from existing District and ARB programs, including stringent 

controls on diesel engines, plus these new near-term measures, are not sufficient 

to bring the air basin into attainment for ozone standards. The necessary 

reductions beyond what the near-term measures will accomplish are large, 150 

tons per day (tpd) of NOx for the 1-hour ozone attainment demonstration and 241

tpd of NOx for the 8-hour ozone attainment demonstration.

The control strategy to attain both the 1-hour ozone and 8-hour ozone standards 

includes the approved commitment to achieve emission reductions from 

advanced technologies approved in the 2007 SIP. Collaborative work by District 

and ARB staff, led to the inclusion in the 2012 AQMP of a number of actions

intended to increase the penetration of zero-emission and near zero-emission 

technologies into a variety of applications including:

 Passenger cars, medium-duty and heavy-duty trucks

 Off-road equipment

 Freight and passenger locomotives

 Marine vessels

 Cargo handling equipment

Implementing these actions will take the combined efforts of the District, ARB, 

and U.S. EPA, in cooperation with many stakeholders including the ports and 

regulated industries. The availability of funds to support technology 

development, demonstration and pilot projects and larger-scale implementation

will be critical to successful implementation of the identified actions.

During development of the AQMP, U.S. EPA commented that the State needs to 

provide periodic reports on the efforts to achieve emission reductions from 

advanced technologies relied upon under CAA section 182(e)(5). In its 

resolution adopting the 2012 AQMP, the District Board directed staff to work with 

ARB to provide annual reports to U.S. EPA describing progress towards meeting 

Section 182(e)(5) emission reduction commitments. ARB and District staff are 

collaborating on activities to research, develop, and deploy advanced 

technologies and will include the annual report in the joint staff work effort. 

II. Implementing the 2007 SIP Strategy

The control strategy in the AQMP relies on reductions of NOx and VOC to meet 

the 1-hour and 8-hour ozone standards. PM2.5 pollution is more complex, 

requiring reductions in directly-emitted PM2.5 as well as the PM2.5 precursors 
6

NOx, SOx, and VOC. Because mobile sources are the largest contributors to 

PM2.5 and ozone-forming emissions, reducing emissions from passenger 

vehicles, trucks, and a variety of off-road engines is key to attaining the PM2.5 

and ozone standards. In developing the 2007 SIP for meeting the annual PM2.5 

standard by 2014 and the 8-hour standard by 2023, the biggest challenge was 

cleaning up the existing fleets of diesel engines. The mobile source strategy 

includes two distinct components – more stringent standards for new engines, 

and cleaning up fleets through accelerated introduction of cleaner engines or by 

retrofitting existing engines. This core strategy is carried forward in the 2012 

SIP. 

Over the past five years, ARB adopted a number of regulations aimed at 

reducing emissions of diesel particulate matter and oxides of nitrogen from 

freight transport sources like heavy-duty diesel trucks, and off-road sources like 

large construction equipment. Phased implementation of these regulations will 

produce increasing emission reduction benefits over time, as the regulated fleets 

are retrofitted, and as older and dirtier portions of the fleets are replaced with 

newer and cleaner models at an accelerated pace. 

ARB’s longstanding programs to reduce emissions from passenger vehicles,

along with the smog check program, provide continuing benefits needed for 

attainment of the 24-hour PM2.5 standard and both ozone standards. 

Implementation of the ARB 2007 State Strategy approved by U.S. EPA4is 

providing new reductions included in the AQMP. Since development of the 2007 

State Strategy, the ARB measures listed in Table 1 have been adopted and 

improvements to California’s smog check and vehicle retirement programs have 

been made. 

Table 1:

Measures in the 2007 State Strategy

Passenger Vehicles

Smog Check Improvements

Expanded Vehicle Retirement (AB 118)

Modifications to Reformulated Gasoline Program

Trucks

Cleaner In-Use Heavy-Duty Trucks

Goods Movement Sources

Auxiliary Ship Engine Cold Ironing & Other Clean Tech

Cleaner Main Ship Engines and Fuel

 

4

76 FR 41562 (July 14, 2011)
7

Port Truck Modernization

Accelerated Intro. of Cleaner Line Haul Locomotives

Clean Up Existing Harbor Craft

Off-Road Equipment

Cleaner In-Use Off-Road Equipment

Other Off-Road Sources

Enhanced Vapor Recovery for Above-Ground Storage 

Tanks

Additional Evaporative Emission Standards

Areawide Sources

Consumer Products Program

A. Clean New and In-Use Heavy-Duty Trucks 

The central element of ARB’s 2007 State Strategy is increasingly stringent 

standards for new trucks as shown in the Table 2. New heavy-duty trucks sold 

since 2010 must emit 98 percent less NOx and PM2.5 than new trucks sold in 

1986. 

Table 2:

Phase-in of truck engine standards

Model Year Applicable Standard

g/bhp-hr

NOx PM

1986 and older 10.7 0.60

1987-2006 From 6.0 to 2.0 From 0.6 to 0.10

2007-2009 1.1 0.01

2010 0.2 0.01

However, older, higher-emitting trucks with long service lives would stay on the 

road for many years to come. With attainment of the PM2.5 standards required 

soon after the cleanest trucks were introduced, the typically slow replacement of 

older trucks on the road with the latest models would not provide emission 

reduction benefits soon enough. 

To address this, ARB developed the Cleaner In-use Heavy-duty Truck SIP 

measure. This measure leverages the benefits provided by new truck emission 

standards by accelerating introduction of the cleanest trucks. The Truck and Bus 

Regulation was adopted in December 2008, and amended in December 2010 to 

account for the reduced emissions resulting from the economic effects of the 
8

recession. This rule represents a multi-year effort to turn over the legacy fleet of 

engines and replace them with the cleanest technology available. 

Starting in 2012, the Truck and Bus Regulation phases in requirements so that 

by 2023 nearly all vehicles will meet 2010 model year engine emissions levels. 

The regulation applies to nearly all diesel fueled trucks and buses with a gross 

vehicle weight rating greater than 14,000 pounds that are privately or federally 

owned, including on-road and off-road yard goats, and privately and publicly

owned school buses. Moreover, the regulation applies to any person, business, 

school district, or federal government agency that owns, operates, leases or 

rents affected vehicles. The regulation also establishes requirements for any instate or out-of-state motor carrier, California-based broker, or any California 

resident who directs or dispatches vehicles subject to the regulation. Finally, 

California sellers of a vehicle subject to the regulation would have to disclose the 

regulation’s potential applicability to buyers of the vehicles. 

Figures 1 and 2 below portray reductions in NOx and PM2.5 emissions from 

in-use trucks within the South Coast, and show the benefits of ARB’s mobile 

strategy.

Figure 1:

South Coast Heavy-duty Diesel Truck NOx Emissions

0

30

60

90

120

150

180

210

2008 2011 2014 2017 2020 2023

NOx (TPD)

Year

Anti-Idling 

Requirements

Public Transit Fleet 

Rule Requirements

In-Use Truck and Bus Rule 

Requirements Begin
9

Figure 2:

South Coast Heavy-duty Diesel Truck PM2.5 Emissions

In addition to the Truck and Bus Regulation, separate regulations reduce 

emissions from other public fleets, solid waste collection trucks and transit buses. 

Trucks that transport marine containers must comply with the drayage truck 

regulation.

B. Cleaner In-Use Off-Road Equipment

As with trucks, the strategy for off-road equipment is based on increasingly 

stringent new off-road diesel engines. As a result of these standards for new 

engines, new construction, mining, industrial and oil drilling equipment will 

become progressively cleaner. The requirements vary according to the power 

rating of engines. Table 3 shows the schedule for phasing in tiered requirements 

for new off-road engines with a power rating between 175 and 300 horsepower 

(hp). Beginning in 2014, new Tier 4 construction equipment with the power rating 

shown below must emit about 96 percent less NOx and PM than new Tier 1 

equipment sold in the year 2000.

0

1

2

3

4

5

6

7

8

9

10

2008 2011 2014 2017 2020 2023

PM2.5 (TPD)

Year

Anti-Idling 

Requirements

Transit, Public, Utilities, and 

Waste Collection Fleet Rules 

In-Use Truck and Bus Rule 

Requirements Begin

Drayage Truck Requirements
10

Table 3:

Phase-in of off-road engine standards

Model year Level of Control Applicable Emission Standard for

New Off-road Engines 175<hp<300

g/bhp-hr

NOx PM

1996-2002 Tier 1 6.9 0.4

2003-2005 Tier 2 4.9* 0.15

2006-2010 Tier 3 3.0* 0.15

2011-2013 Tier 4 interim 1.5 0.015

2014+ Tier 4 final 0.3 0.015

*Reflects combined limit for non-methane hydrocarbons and NOx

However, large diesel off-road equipment typically remains in use for long 

periods of time. As with heavy-duty trucks, this long life means that newer, 

lower-emitting engines would be introduced into fleets relatively slowly. The 

impact of this is that emission reductions and associated health benefits from 

these cleaner engines would also be fairly slow to materialize. To address this, 

the 2007 SIP included the Cleaner In-use Off-road Equipment measure.

First approved in 2007, the Off-Road Regulation was amended in 2010 in light of 

the impacts of the economic recession. Affected off-road equipment is used in 

construction, manufacturing, the rental industry, road maintenance, airport 

ground support and landscaping. In December 2011, the Off-Road Regulation 

was modified to include on-road trucks with two diesel engines.

The Off-Road Regulation will significantly reduce emissions of diesel PM and 

NOx from the over 150,000 in-use off-road diesel vehicles that operate in 

California by requiring their owners to modernize their fleets and install exhaust 

retrofits. The regulation affects dozens of vehicle types used in thousands of 

fleets by requiring owners to modernize their fleets by replacing older engines or 

vehicles with newer, cleaner models, retiring older vehicles or using them less 

often, or by applying retrofit exhaust controls. 

The Off-Road Regulation imposes idling limits on off-road diesel vehicles, 

requires a written idling policy, and requires a disclosure when selling vehicles. 

The regulation also requires that all vehicles be reported to ARB and labeled, 

restricts the addition of older vehicles into fleets, and requires fleets to reduce 

their emissions by retiring, replacing, or repowering older engines, or installing 

verified exhaust retrofits. The requirements and compliance dates of the 

Off-Road Regulation vary by fleet size.

Figure 3 below portrays reductions in NOx emissions from off-road equipment 

within the South Coast, and shows the benefits of ARB’s mobile strategy.
11

Figure 3:

South Coast Off-Road Equipment NOx Emissions

C. Passenger Cars

The Board established California’s Low Emission Vehicle (LEV) program in 1990, 

and the LEV2 program in 1998. Additionally, ARB’s Zero Emission Vehicle 

(ZEV) regulation which affects passenger cars and light-duty trucks, has spurred 

movement towards commercialization of advanced clean cars and light-duty 

trucks. As a result, many new gasoline engines now emit at extremely low

emission levels of smog forming emissions. Conventional hybrid electric vehicles 

have been commercialized, and the number of models offered for sale is quickly 

expanding. Recently, battery electric vehicles and plug-in hybrid electric vehicles 

have been introduced for sale, and fuel cell electric vehicles are expected to 

follow. 

ARB’s Advanced Clean Cars (ACC) Program, approved in January 2012, is a 

pioneering approach of a ‘package’ of regulations, that although separate in 

construction, are related in terms of the synergy developed to address both 

ambient air quality needs and climate change. The ACC program combines the 

control of smog, soot causing pollutants and greenhouse gas emissions into a 

single coordinated package of requirements for model years 2015 through 2025. 

The program assures the development of environmentally superior cars that will 

continue to deliver the performance, utility, and safety vehicle owners have come 

to expect. 
12

The ACC program approved by ARB in January 2012 included amendments 

affecting the current ZEV regulation through the 2017 model year in order to 

enable manufacturers to successfully meet 2018 and subsequent model year 

requirements. The ZEV amendments for 2018 and subsequent model years in 

the ACC program approved by ARB in January 2012 are intended to achieve 

commercialization through simplifying the regulation and pushing technology to 

higher volume production in order to achieve cost reductions.

The ACC Program will produce increasing benefits over time as new cleaner cars 

enter the fleet displacing older and dirtier vehicles. In this manner, the benefits in 

2023 will be realized through the cumulative reduction in emissions achieved by 

new cars entering the fleet in 2017 through 2023. This program will continue to 

provide benefits well after 2025 as vehicles meeting the new standards replace 

older, higher-emitting vehicles.

Many additional programs are currently in place to reduce emissions from the 

passenger car legacy fleets and accelerate fleet turn over. The Smog Check 

Program ensures that passenger vehicles stay clean as they age and on-board 

diagnostic systems identify smog control problems. The Smog Check Program is 

continuously being improved to provide additional emission reductions such as 

requiring stricter inspection standards and annual inspection of older vehicles. 

ARB is also active in encouraging consumers with older dirtier vehicles to retire 

them early. Replacing older dirtier vehicles with cleaner new vehicles provides 

permanent emission reductions.

D. Reducing Emissions from Ocean-going Vessels 

Emissions from ocean-going vessels (OGV) impact coastal areas, especially 

densely populated regions hosting ports for international trade. The 2007 SIP 

relied on a suite of state, local, national, and international programs to reduce 

OGV emissions, which are summarized below. 

The two major regulations adopted by ARB to reduce emissions from OGVs 

address shorepower and cleaner fuels. In December 2007, the Board adopted 

the OGV Shorepower Regulation. This rule reduces emissions from diesel 

auxiliary engines on container ships, passenger ships, and refrigerated-cargo 

ships while berthing at a California port. 

In 2008, the Board adopted a comprehensive OGV Clean Fuel Regulation which

requires vessel operators to use cleaner distillate fuels in their main engines, 

auxiliary engines, and auxiliary boilers within 24 nautical miles (nm) of the 

California coastline and islands. The regulation also includes a “Phase II” fuel 

standard requiring the use of 0.1 percent sulfur fuel in 2014. The use of these 

cleaner fuels is resulting in dramatic reductions in diesel PM and SOx emissions, 

as well modest reductions in NOx emissions. 
13

Port authorities in California have also developed a number of measures for 

OGVs visiting their ports, which are typically implemented through incentive 

programs or lease agreements. The Ports of Los Angeles and Long Beach 

(Ports) have the most comprehensive program. In 2006, the Ports adopted the 

San Pedro Bay Ports Clean Air Action Plan, designed to reduce the emissions 

from a variety of port sources, including OGVs. The plan was updated in 2010. 

Currently, the Ports are working on developing the infrastructure and lease 

agreements to support the statewide shorepower regulation, implementing 

voluntary vessel speed reduction, and supporting the demonstration and 

deployment of advanced OGV emission control technologies. While the Ports 

handle most of the local programs for OGVs, the District also has rules to control 

VOC emissions from tankers during loading and lightering operations. 

The 2007 SIP includes, as part of the U.S. EPA approved annual PM2.5 and 8 

hour SIPs, a “backstop” measure for sources of pollutants at the ports, MOB-03. 

That measure is to be implemented through district rulemaking, which would 

include the setting of appropriate emissions targets that would trigger 

implementation were those targets to be exceeded. No District rulemaking or 

further SIP revisions happened between 2007 and 2012 to implement MOB-03 

for either the PM annual or 8-hour standards.

In the 2012 SIP, the District proposed to include a backstop measure, IND-01, 

that would ensure that emissions targets assumed for port-related sources, 

intended to help attain and maintain the 24-hour PM2.5 standard, are actually 

achieved. Responding to concerns raised during the public AQMP development 

process and testimony at its December 7, 2012, meeting, the District Board did 

not include the proposed measure in the SIP revision. It directed the issue to an 

existing committee of the District Board that deals with port-related issues. As a 

result, there is currently no inclusion of the port backstop measure at this time for 

the 24-hour PM2.5 SIP. The District Board is considering the adoption of IND-01 

at its February meeting, and if the District Board decides to include measure IND01 in the 24-hour PM2.5 SIP, it would be forwarded to CARB at a later date for 

inclusion in the SIP.

III. Control Strategy and Attainment Demonstrations 

The control strategies and SIP measures in the 2007 SIP are carried forward in 

the 2012 AQMP, and included in the attainment demonstrations for the 24-hour 

PM2.5 standard and the 1-hour ozone standard. In addition to the 2007 SIP 

measures, the AQMP includes several new District control measures needed for 

attainment of the PM2.5 standard by 2014, and to make progress on the meeting 

the 1-hour and 8-hour ozone standards. 
14

A. 2007 SIP Emission Reduction Commitments

The control strategy to attain the 24-hour PM2.5 standard in 2014 and the 1-hour 

ozone standard in 2022 rely on the U.S. EPA approved commitments for 

emission reductions made by ARB for sources under its regulatory authority.

U.S. EPA acknowledged in the Federal Register Notice approving the South 

Coast 8-hour ozone SIP that ARB made enforceable commitments to achieve 

aggregate emissions reductions in the South Coast for the years of 2014, 2020 

and 2023. Table 4 taken from the Federal Register shows the ARB commitment 

reductions in those years.5 

Table 4:

Emission Reductions (TPD) in 2014, 2020 and 2023

Year NOx VOC

2014 152 46

2020 144 52

2023 141 54

2023 CAA 182(e)(5) 241 40

While the 2007 SIP strategy included estimates of the emission reductions from 

each of the individual new measures, the commitment in the 2007 SIP was to 

achieve the aggregate emission reductions identified from the existing strategy 

and adopted SIP. Therefore, if a particular measure does not get its expected 

emission reductions, the State is still committed to achieving the total aggregate 

emission reductions, whether this is realized through additional reductions from 

the new measures, or from alternative control measures or incentive programs. 

If actual emission decreases occur that exceed the projections reflected in the 

emission inventories and the 2007 SIP, the actual emission decreases may be 

counted toward meeting ARB’s total emission reduction commitments.

In the 2012 AQMP, the District quantified reductions for 1-hour ozone attainment 

in 2022 from measures included in the 2007 SIP. The District calculated 

reductions from seven of these approved control measures (four on-road mobile 

source measures and three off-road measures) carried forward from the 2007 

8-hour ozone SIP. The expected benefits from these seven measures in 2022 

were calculated by interpolating between their expected reductions in 2020 and 

2023. The quantified reductions from these measures are part of the already 

approved commitment for aggregate emission reductions in 2020 (see table 4) 

two years prior to 2022 attainment deadline. The commitment to achieve 

aggregate reductions is consistent with the 2007 SIP adopted in September 2007

and revised in April 20095. While expected reductions were calculated for each 

measure, the enforceable commitment is for the aggregate reductions,

 

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recognizing the reality that individual measures may result in more or less 

reductions than expected. 

The 182(e)(5) advanced technology actions identified for the 1-hour ozone 

attainment demonstration are also proposed in the AQMP to advance

commitments made in the 2007 8-hour ozone SIP.

B. Attainment Demonstrations for PM2.5 and Ozone

The 2012 AQMP demonstrates attainment of the 24-hour PM2.5 standard by 

2014 and the 1-hour ozone standard by 2022, the applicable deadlines for each 

pollutant. The 2012 AQMP attainment demonstrations for both the 24-hour 

PM2.5 and 1-hour ozone were conducted using photochemical dispersion and 

meteorological modeling tools and procedures developed according to U.S. EPA 

modeling guidelines. Air quality modeling is used to establish a "carrying 

capacity" – a combination of precursor emissions that the air basin can 

accommodate without exceeding the health-based standard – thus setting 

targets that the control strategy must meet to attain the federal standards. 

The air quality modeling performed for the 2012 AQMP has undergone scientific 

peer review and was made available for public review. ARB and South Coast 

District staffs worked together on the modeling for this plan, including 

development of a gridded modeling inventory and meteorological and geological 

data inputs, model performance analysis, and validation of the attainment 

demonstrations.

U.S. EPA’s PM2.5 modeling guidance recommends the use of corroborating 

evidence to support the future year attainment demonstration. The weight of 

evidence demonstration for the 2012 AQMP includes brief discussions of the 

observed 24-hour PM2.5 levels, emissions trends, and future year PM2.5 

predictions. The weight of evidence discussion in Chapter 5 of the 2012 AQMP 

focuses on the trends of 24-hour PM2.5 and key precursor emissions to provide 

justification and confidence that the Basin will meet the federal standard by 2014.

No specific modeling guidance applies to the 1-hour ozone analysis since the 

standard has been revoked. The 1-hour ozone attainment demonstration is 

based on the deterministic modeling approach to directly predict future year 

concentrations. The alternate relative reduction factor approach, applied using a 

stratified or tiered approach to develop station specific projections of 2022 1-hr 

ozone concentrations, is used as part of the weight of evidence discussion in 

Section 5 of Appendix VII of the 2012 AQMP.

C. Actions to Achieve Reductions from Advanced Technologies

The 2007 SIP included a commitment to achieve reductions form the use of 

advanced zero and near-zero emission technologies in the on-road and off-road 
16

fleets to meet emission reductions needed for the federal ozone standard in 

2023. This provision of the Act, section 182(e)(5), reflects the need for new 

development and deployment of new technologies in regions with the most 

severity ozone air quality problems. 

The CAA section 182(e)(5) provision is available to areas classified as extreme, if 

feasible technology does not exist for areas to meet the ozone standard by the 

applicable deadline. In its approval of the South Coast 2007 8-hour ozone SIP, 

U.S. EPA stated that:

“EPA interprets this provision to mean that the measures approved 

under section 182(e)(5) may include those that anticipate future 

technological developments as well as those that require complex 

analyses, decision making and coordination among a number of 

government agencies.” 6

The 2012 AQMP identifies actions to reduce mobile source emissions through 

programs to accelerate the penetration and deployment of partial zero-emission 

and zero-emission vehicles and to accelerate retirement of older gasoline and 

diesel powered vehicles. The 2012 AQMP also lays out actions for the 

deployment of zero and near-zero technologies for goods movement related 

sources, including on- and off-road vehicles and equipment, locomotives, cargo 

handling equipment, commercial harbor craft, OGVs, and aircraft engines. The 

actions implement and do not amend the existing U.S. EPA approved SIP 

commitment.

Specifically, these actions include:

 accelerating the penetration of on-road partial zero-emission and 

zero-emission light and heavy-duty electric, hybrid and other clean 

alternative fuel vehicles;

 accelerating the retirement of older light, medium, and heavy-duty vehicles 

through financial incentives; 

 repowering or replacing older Tier 0 and Tier 1 off-road equipment; 

 targeting emission reductions from heavy-duty vehicles serving near-dock 

railyards;

 reducing emissions from locomotives by accelerated use of Tier 4 

locomotives for freight, the replacement of existing Tier 0 passenger 

locomotives with Tier 4 locomotives, and the development and 

deployment of zero-emission and near-zero emission technologies for 

locomotives;

 reducing emissions from ships, by reducing emissions from ocean-going 

marine vessels while at berth, initiating an incentives program for cleaner 

ocean-going vessels to call at the ports, demonstrating control 

technologies that could be deployed on commercial harbor craft, and 

 

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77 FR 12674 at 12686 (March 1, 2012)
17

demonstrating control technologies to further reduce emissions from 

ocean-going vessels;

 advancing the development and deployment of zero- and near-zero 

emission technologies for cargo handling equipment;

 advancing the development of retrofit technologies to further reduce 

emissions from older off-road equipment; and

 developing cleaner aircraft engines through the Federal Aviation 

Administration’s Continuous Lower Energy, Emissions and Noise 

Program, and mechanisms to route the cleanest aircraft to serve the 

South Coast Air Basin.

D. Consumer Products

Under State law, ARB has regulatory responsibility for reducing VOC emissions 

from consumer products. Currently, ARB’s Consumer Products Regulation 

exempts low vapor pressure (LVP) substances when determining compliance 

with VOC limits. During AQMP development, the District considered a measure 

proposing that research be done to determine if the exemption should be 

modified. This proposal was based on testing conducted by the District 

indicating that some LVP-VOCs may readily evaporate and available to 

participate in ozone or organic aerosol formation. 

At its December 7, 2012, meeting, the District Board removed the proposed 

measure regarding LVP research from the AQMP. Instead, the District Board 

directed District staff to request that ARB undertake research to determine 

whether some of the exempt substances contribute to ozone and should be 

further controlled for ozone attainment. ARB staff has already begun to design a 

research effort. Potential research tasks include laboratory chamber studies to 

further evaluate ozone and aerosol impacts, quantification of volatilization rates 

under ambient conditions, and evaluation of the environmental fate of LVP-VOCs 

emissions.

IV. Other Clean Air Act Planning Requirements

In addition to the core requirement for a control strategy and an attainment 

demonstration, the CAA specifies submittal of an emission inventory, 

contingency measures, transportation control conformity budgets, a VMT offset 

demonstration, and a Reasonably Available Control Measure (RACM) analysis.

A. Emission Inventory

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

with an estimate of amount of pollutants from each source or source category 

over a given period of time. The inventories used in the South Coast 2012 

AQMP were developed using the most recent planning assumptions and the best 
18

available technical information and meet the requirements of the Act following 

U.S. EPA guidance. The 2008 and 2014 baseline annual and summer 

inventories can be found in Chapter 3 of the South Coast 2012 AQMP. The 2022 

baseline summer planning inventory can be found in Appendix VII of the South 

Coast 2012 AQMP.

ARB and District staff worked jointly over a two-year period to develop the 

emission inventory for the South Coast 2012 AQMP. This included efforts to 

ensure that the growth projections reflected the economic recession and the 

emissions reflected the unique nature of the 24-hour PM2.5 problem. The 

inventory includes updated growth profile data using sector specific forecasts, 

new methodologies and adopted rules, along with updated on-road mobile 

source activity from SCAG. 

B. Contingency Measures

The Act requires that the SIP provide for contingency measures in the event of a 

failure to attain the 24-hour PM2.5 or the 1-hour ozone standard by the

applicable attainment date. Additionally, extreme ozone nonattainment areas 

relying on CAA section 182(e)(5) provisions must provide contingency reductions 

should associated advanced technology reductions fail to materialize. These 

contingency measures must be already be adopted, take effect without further 

ARB or air district action, not be relied upon to demonstrate attainment for the 

time in which they serve as contingency measures, and should contain trigger 

mechanisms for implementation. U.S. EPA guidance states that the contingency 

measure requirements can be satisfied with an already adopted control measure 

provided those controls will achieve emission reductions above and beyond what 

is needed to demonstrate attainment. 

The attainment contingency measure demonstration for the 24-hour PM2.5 

standard is included in Chapter 6 of the 2012 AQMP and represents a sufficient 

margin of “about one year’s of progress” and “generally linear” progress to satisfy 

federal contingency measure requirements. Control Measure CMB-01 Phase I 

seeks to achieve an additional two tons per day of NOx emissions reductions 

from the RECLAIM market if the 24-hour PM2.5 standard is not attained by 2014. 

The CMB-01 Phase I measure is scheduled for near-term adoption and includes 

the appropriate automatic trigger mechanism and implementation schedule 

consistent with CAA contingency measure requirements. 

In order to rely on CAA section 182(e)(5), federal law requires that a State 

commit to submit no later than three years before the attainment deadline, SIP 

revisions containing contingency measures. The contingency measures are to 

be implemented should the anticipated technology measures approved under 

section 182(e)(5) not achieve the planned reductions. Under section 172(c)(9), 

the CAA also requires that a State commit to submit contingency measures three 
19

years before the attainment deadline that would be triggered should the State fail 

to attain the standard on time.

As a result, in compliance with the CAA for the South Coast 8-hour SIP, ARB has 

made an enforceable commitment to submit, no later than 2020, contingency 

measures that meet the contingency requirements for both attainment and 

advanced technologies. For the 1-hour ozone standard with a 2022 attainment 

date, ARB will also submit the required contingency measures by the deadline of 

2019.

C. Transportation Conformity Budgets

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

funding or approval must be fully consistent with the SIP. U.S. EPA’s 

transportation conformity rule details requirements for establishing motor vehicle 

emission budgets (budgets) in SIPs for the purpose of ensuring the conformity of 

transportation plans and programs with the SIP. 

The 2012 AQMP establishes on-road motor vehicle emission budgets and a 

trading mechanism for the 24-hour PM2.5 standard. Emission budgets for direct 

PM2.5 and the PM2.5 precursors VOC and NOx, were calculated for the 2014 

attainment year using EMFAC2011 and reflect annual average emissions. The 

emission budgets established in the 2012 AQMP fulfill the requirements of the 

Act and U.S. EPA regulations to ensure that transportation projects will not 

interfere with progress and attainment of the 24-hour PM2.5 standard. Additional 

detail on the on-road motor vehicle budgets can be found in chapter 6 of the 

2012 AQMP.

D. Ozone VMT Offset Demonstration

The 2012 AQMP includes a VMT offset demonstration that fully addresses the 

CAA requirements under section 182(d)(1)(A), and is responsive to U.S. EPA 

guidance developed in response to a 2011 Ninth Circuit Court of Appeals ruling 

on this section of the Act. Appendix VIII of the 2012 AQMP demonstrates that 

emissions due to VMT growth are appropriately offset by transportation control 

strategies and transportation control measures in the attainment years of 2022 

for the 1-hour ozone demonstration in the 2012 AQMP, and 2023 for the 

approved 8-hour ozone SIP. The 2012 AQMP also includes an additional 

demonstration that VMT emission reductions for the 8-hour ozone meet an 

alternative VMT offsets methodology proposed by U.S. EPA.

E. Reasonably Available Control Measures Analysis

As specified in the Act, SIPs shall provide for the implementation of all 

Reasonably Available Control Measures (RACM) as expeditiously as practicable, 

including at minimum Reasonably Available Control Technology (RACT), and 
20

shall provide for attainment of the standards. U.S. EPA has decided to interpret 

this as those measures that are technologically and economically feasible and 

when considered in aggregate, would advance the attainment date by at least 

one year.

The District RACM/RACT demonstration includes a comparison of stationary 

source measures the District has implemented or plans to implement with 

measures implemented by other agencies within and outside of the State. For 

the majority of stationary and area source categories, the District rules are the 

most stringent in California. Where necessary, the District identified for adoption 

by the district additional measures in the 2012 AQMP.

Based U.S. EPA guidance, the District concluded the 2012 AQMP meets the 

RACM/RACT requirements of the CAA, and the U.S. EPA’s PM2.5 

Implementation Rule7. These requirements include a demonstration that 

no additional feasible measures could be identified that could, in aggregate,

accelerate attainment by one year. The complete RACM and RACT assessment 

is provided in Appendix VI of the 2012 AQMP.

In addition, U.S. EPA’s RACM guidelines call for an analysis of transportation 

control measures proposed in the plan. Consequently, the Southern California 

Association of Governments (SCAG) has completed a RACM determination for 

transportation control measures that can be found in Appendix IV-C of the 

2012 AQMP.

California’s comprehensive mobile source program continues to be RACM as it 

expands and further reduces emissions. Given the significant emission 

reductions needed for attainment in California, ARB has adopted the most 

stringent control measures nationwide for on-road and off-road mobile sources 

and the fuels that power them. These measures provide a significant amount of 

emission reductions needed for the South Coast Air Basin to attain the PM2.5 

standard.

For 1-hour the RACM demonstration, the District staff’s analysis, found in

Attachment 2 of Appendix VII, concluded that it has developed effective controls 

to meet the 1-hour ozone attainment date as expeditiously as possible.

F. Environmental Impacts

The South Coast Air Quality Management District prepared a Draft Program 

Environmental Impact Report (Draft Program EIR) for the 2012 AQMP. The Draft 

Program EIR was released for a 45-day public review and comment period from 

September 7, 2012 to October 23, 2012. The Draft Program EIR concluded that 

the 2012 AQMP has the potential to generate significant adverse environmental 

 

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impacts to the following environmental topic areas: construction air quality, 

energy (increased electricity and natural gas demand), hazards and hazardous 

materials, water demand, construction noise, and transportation and traffic. 

Measures were identified to mitigate to the maximum extent feasible potentially 

significant adverse impacts to all environmental topics identified above. In spite 

of implementing all feasible mitigation measures, impacts to all environmental 

topics remained significant. In addition, the Draft Program EIR included an 

analysis of potentially significant adverse cumulative environmental impacts and 

identified and evaluated the relative merits of four project alternatives, including a 

No Project Alternative. The District included the comment letters received on the 

Draft Program EIR and written responses in Appendix G of the Final Program 

EIR. 

At the December 7, 2012 public hearing when the District Governing Board 

adopted the 2012 AQMP, it also the certified and adopted the Final Program EIR, 

and adopted a Statements of Findings and Overriding Considerations and a 

Mitigation Monitoring Plan.

V. Staff Recommendations

ARB staff recommends that the Board:

1. Approve the South Coast Air District Air Quality Management Plan as a 

revision to the California SIP with attainment demonstrations for the

24-hour 35 PM2.5 standard by 2014 and the 1-hour ozone standard by 

2022;

2. Direct staff to work with the District staff on implementation of the actions 

identified in the AQMP to accelerate use of advanced technologies to fulfill

the existing 182(e)(5) SIP commitments;

3. Direct staff to work with the District to staff to provide annual reports to 

U.S. EPA describing progress toward meeting section 182(e)(5) emission 

reduction commitments;

4. Direct the Executive Officer to submit the South Coast 2012 AQMP to 

U.S. EPA as a revision to the California SIP.