State of California 

AIR RESOURCES BOARD 

STAFF REPORT 

ANALYSIS OF THE WESTERN MOJAVE DESERT AND VENTURA 

COUNTY 8-HOUR OZONE ATTAINMENT PLANS 

Date of Release: 

Scheduled for Consideration: 

June 13,2008 

June 26,2008 

This report has been reviewed by the staff of the California Air Resources 

Board and approved for publication. Approval does not signify that the 

contents necessarily reflect the views and policies of the Air Resources 

Board, nor does mention of trade names or commercial products constitute 

endorsement or recornmendation for use. 

== = C.a*io thb+mUmw*hs .inw AIR RESOURCES BOARD 
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TABLE OF CONTENTS 

... EXECUI-IVE SUMMARY .......................................................................... 111 

INTRODUCTION ............................................................................................. I

WESTERN MOJAVE DESERT OZONE NONATTAINMENT AREA ................ 8 

VENPURA COUNTY OZONE NONATTAINMENT AREA ............................. 20 
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EXECUTIVE SUMMARY 

Air Resources Board (ARB) staff is proposing Board approval of the Western 

Mojave Desert and Ventura County 8-hour ozone attainment plans. These plans 

are proposed revisions to California's State Implementation Plan (SIP) for ozone. 

The Western Mojave Desert, which consists of the Antelope Valley portion of Los 

Angeles County and the southeastern portion of San Bernardino County, and 

Ventura County are currently designated by U.S. EPA as nonattainment for the 

8-hour ozone standard with moderate classification. Under the federal Clean Air 

Act Amendments of 1990 (the Act), moderate ozone nonattainment areas have a 

nominal attainment date of June 15, 2010. 

The Western Mojave Desert and Ventura planning areas are downwind of the 

South Coast Air Basin (South Coast). The Western Mojave Desert is also 

downwind of the San Joaquin Valley Air Basin (San Joaquin Valley), though to a 

lesser extent. Prior ARB transport assessments indicate that ozone transport 

froni these upwind areas contributes to high ozone levels in the downwind areas 

during the summer ozone season. Photochemical ozone modeling conducted by 

the South Coast Air Quality Management District (SCAQMD) indicates that 

emissions generated by sources within the Western Mojave Desert are not 

sufficient to cause ozone violations, indicating that South Coast emissions levels 

must decrease before the Western Mojave Desert area can attain the 8-hour 

national ambient air quality standards (NAAQS). Modeling indicates that 

err~ission reductions in the South Coast are also needed to ensure attainment in 

Ventura County. 

Due to this ozone transport, the Antelope Valley Air Quality Management District 

(AVAQMD) and Mojave Desert Air Quality Management District (MDAQNID) have 

each requested a reclassification to severe-17 for their respective portions of the 

Western Mojave Desert Ozone Nonattainment Area, which would result in an 

attainment date of 2021 for this region. The Ventura County Air Pollution Control 

District (VCAPCD) has requested that U.S. EPA reclassify Ventura County as a 

serious nonattainment area, which would result in a 2013 attainment date. 

This staff report summarizes the ozone attainment plans for both the Western 

Mojave Desert and Ventura County. The report contains discussions of air 

quality modeling and weight of evidence analyses supporting the reclassification 

request and the attainment demonstration, as well as the control strategy, 

conformity budget, reasonable further progress demonstration, and other plan 

elements. 
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I. INTRODUCTION 

A. Overview 

Air pollution levels in the Western Mojave Desert and Ventura County exceed the 

national ambient air quality standard (NAAQS) for ozone of 0.08 parts per million 

(ppm), averaged over an 8-hour period. The U.S. Environmental Protection 

Agency (U.S. EPA) has designated both the Western Mojave Desert, which 

consists of the Antelope Valley portion of Los Angeles County and the 

southeastern portion of San Bernardino County, and Ventura County as 

nonattainment for the 8-hour ozone standard with moderate classification. Under 

the federal Clean Air Act Amendments of 1990 (the Act), moderate ozone 

nonattainment areas have a June 15.2010 attainment date. 

The Antelope Valley Air Quality Management District (AVAQMD) and Mojave 

Desert Air Quality Management District (MDAQMD) have each requested a 

reclassification to severe-17 for their respective portions of the Western Mojave 

Desert Ozone Nonattainment Area, which would result in an attainment date of 

2021 for this region. The Ventura County Air Pollution Control District (VCAPCD) 

has requested that U.S. EPA reclassify Ventura County as a serious 

nonattainment area, which would result in a 2013 attainment date. Each of these 

districts has adopted a plan demonstrating attainment by the new attainment 

deadlines. Each plan includes air quality modeling and weight of evidence 

(WOE) analyses supporting the reclassification request and the attainment 

demonstration, as well as the control strategy, conformity budget, reasonable 

further progress (RFP) demonstration, and other plan elements required by the 

Act. 

Each district made its draft attainment demonstration plans available for a 30-day 

public review period prior to local adoption. State law specifies that the Air 

Resources Board (ARB or Board) must adopt the nonattainment area plans 

approved by a local district, unless ARB finds, after a public hearing, ,that the 

locally adopted plans will not meet the requirements of the Act. 

ARB staff has reviewed the 8-hour ozone attainment plans prepared by each of 

these I~cal districts, and recommends that the Board adopt these plans as 

proposed revisions to California's State Implementation Plan (SIP) for ozone. 

B. Air Quality Planning Background 

The Act establishes planning requirements for areas that routinely exceed the 

health-based NAAQS. These nonattainment areas must develop and enact SIPS 

that demonstrate how they will attain the standards by specified dates. Federal 

law holds each state responsible for implementing the provisions of the Act. 
State law' 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. State law 

further specifies that the ARB must adopt the nonattainment area plan approved 

by a local air district, unless the ARB ,finds, after a public hearing, that the locally 

adopted plan will not meet the requirements of the ~ct.~ California SIP revisions 

must be submitted to U.S. EPA by ARB. The rules and commitments in a 

U.S. EPA-approved SIP are federally enforceable. The Act 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. 

C. 8-Hour Ozone Planning Requirements 

Attainment demon strati or^ plans must include the following: 

a current, comprehensive, and accurate emissions inventory; 

air quality modeling demonstrating attainment of the NAAQS; 

con,trol strategies capable of meeting attainment, and contingency 

measures in the event the controls fall short of achieving needed 

reductions; 

RFP plans; 

demonstration that all reasonably available control technology (RACT) or 

reasonably available control measures (RACM) have been applied to 

existing sources; and 

transportation conformity budgets. 

Area Classifications 

The Act provides for ozone nonattainment areas to be 

classified according to pollution levels recorded in each 

area. Areas with lower classifications have the least 

amount of time to meet the standard. Areas with higher 

classifications are given more time to meet the 

standard and must adopt more stringent requirements 

for major new sources and modifications. Using ozone 

levels recorded from 2001 through 2004, U.S. EPA 

classified both the Western Mojave Desert and Ventura 

County as moderate nonattainment areas for the 8-hour 

ozone standard. The text box shows classifications 

and nominal attainment years for the 8-hour ozone 

standard. 

The specific attainment date for the 8-hour ozone 

NAAQS is June 1 5 of the attainment year. Because the 

ozone attainment deadlines are mid-year, guidance 

I Area Classifications reflect )i I severity of local pollution 1; 

levels and establish the area's 

attainment deadline. 8-hour 

( ozone standard deadlines for 1:; I each classification are shown 1 

Marginal 

Moderate 

I Extreme 1 2024 I 

' California Health and Safety Code (HSC) Section 39602 

HSC Section 41650(a). 
calls for the analysis of attainment to be done for the year prior to the actual 

attainment year. Therefore, emissions and emission reduction targets must be 

achieved by the year prior to the actual attainment year. In the case of a nominal 

attainment deadline of 2010, emission reduction targets must be met in 2009 to 

demonstrate 201 0 attainment. 

Reclassification 

The Act allows states to request the reclassification of any ozone nonattainment 

area to a higher classification, and requires the Administrator to grant such 

requests.' The AVAQMD and MDAQMD have requested a reclassification of the 

Western Mojave Desert from moderate to severe-17, while the VCAPCD has 

requested a reclassification from moderate to serious. ARB Executive Officer 

James Goldstene submitted these requests to U.S. EPA on February 14, 2008. 

U.S. EPA approved the Ventura County request effective June 19,2008, 

characterizing its decision to ap rove voluntary reclassification requests as 

nondiscretionary under the Act.P In its Ventura County reclassification notice, 

U.S. EPA indicated that reclassification requests for other California areas were 

pending consultation with Indian tribes in the affected areas. 

D. Emission Inventories 

An emissions inventory is a critical tool used to evaluate, control, and mitigate air 

pollution. At its core, an emissions inventory is a systematic listing of the sources 

of air pollutants along with the amount of pollutants emitted from each source or 

category over a given time period. The planning emissions inventory is divided 

into four major categories: point, area-wide, on-road mobile and other mobile 

sources. The summer season inventory is used for ozone planning because it 

reflects the activity levels and conditions present when higher ozone levels occur 

in the Southern California region. 

California's 2007-2008 SIP updates use a 2002 baseline inventory; the inventory 

was calibrated to 2002 emissions and activity levels, and inventories for other 

years are back-cast or forecast from that base inventory. The inventories reflect 

rules adopted through December 31, 2006. 

On-road motor vehicle emissions were generated using ARB's mobile source 

emissions model, EMFAC2007. Off-road mobile source emissions were 

generated using ARB's OFFROAD model. Both models were developed for use 

in the 2007-2008 SIP revisions, and represent significant improvements over 

models used in prior SIP updates. On-road motor vehicle activity data reflect 

projections provided by SCAG in February and March, 2008. 

' Clean Air Act, Section 18 1 (b)(3) 

Federal Register Volume 73 No. 98, May 20,2008, page 29074. 
E. A ir Qualitv Modeling 

The Western Mojave Desert and Ventura County ozone nonattainment areas are 

small parts of the greater Southern California region. The photochemical model 

in these plans covers the entire Southern California region and a portion of 

northern Mexico. The modeling effort has been performed as a joint project by 

all of the air districts in the region and ARB, with SCAQMD staff and resources 

providing most of the modeling and ARB staff providing WOE supplementary 

reviews. 

The modeled attainment demonstration in this plan was prepared using 

photochemical dispersion and meteorological modeling tools developed in 

response to U.S. EPA modeling guidelines, and recommendations from air 

quality modeling experts. The model predicts fut~.~re ambient ozone 

concentrations under historical conditions that led to high ambient ozone 

concentrations. These conditions are typically multi-day episodes in which the 

State and national ozone standards were exceeded. 

The meteorological fields were generated using the MM5 prognostic 

meteorological model, and district staff developed the required emissions 

inventories. The ozone air quality modeling utilized the Comprehensive Air 

Quality Model with Extensions (CAMx) model, with initial and boundary 

conditions based on estimates of clean-air concentrations. Analysis of the model 

outputs included the estimation of I-hour and 8-hour ozone concentrations for 

each ozone monitoring site within the domain, as well as statistical measures 

comparing observed and simulated ozone concentrations. These analyses were 

used to evaluate model performance by sub-region within the domain. 

The modeling domain is based on the domain defined for the 1997 Southern 

California Ozone Study (SCOS) and includes the South Coast Air Basin and the 

surrounding coastal, desert, and mountain areas. The northern boundary of the 

model extends into Santa Barbara and Kern counties, while the southern 

boundary extends into Mexico. The eastern boundary of the modeling extends to 

the California-Nevada border, while the western boundary extends into the 

Pacific Ocean. The domain horizontal grid is 116 by 80 cells, with a resolution of 

five kilometers. This large domain allows an evaluation of the impact of 

emissions generated in the region's urban core on surrounding areas such as the 

Western Mojave Desert and Ventura County. 

The emissions inventory used for photochemical modeling is consistent with the 

emissions inventories presented in the locally adopted attainment demonstration 

plans and summarized in this report. 

The photochemical modeling was conducted by staff of the South Coast Air 

Quality Management District (SCAQMD), using the models and methodologies 

described in Appendix V of the SCAQMD's 2007 Air Quality Management Plan 
(AQMP). Further information about the photochemical modeling approach is 

available from the SCAQMD, at: 

http://www.aqmd .gov/ac1mp/07aqmp/aqmp/Appendix V. pdf. 

1. Modeled Attainment Projection 

Future years are simulated twice: ,first, using the uncontrolled emissions 

inventory; and second, using a reduced err~issions inventory controlled by the 

proposed ozone control strategy. Comparing the uncontrolled and controlled 

ambient ozone concentrations identifies the effectiveness of the proposed ozone 

control strategy. The modeling demonstrates attainment if using an emissions 

inventory that reflects the proposed control strategy results in projected design 

values, in the attainment year, that achieve the ozone NAAQS. 

As required by U.S. EPA guidance, a relative reduction factor (RRF) approach 

was used in projecting future design values. The RRF reflects the ratio between 

the future year model prediction (in this case the end of 2012 for Ventura, and 

2020 for the Western Mojave Desert) and the reference year model prediction (in 

this case 2005). A reference year design value is then multiplied by the RRF to 

project a future year design value. The modeling conducted by the SCAQMD for 

use in the Western Mojave Desert and Ventura SIP submittals satisfies the 

modeled attainment test. 

2. Weight of Evidence 

Due to the uncertainties inherent in photochemical air quality modeling, U.S. EPA 

guidance provides for the use of analyses, such as air quality and emissions 

trends analyses, to supplement air quality modeling results. Under U.S. EPA's 

guidelines for the use of WOE in ozone attainment demonstrations, a WOE 

analysis may be used to support a determination that attainment will be 

achieved, despite the results of the modeled attainment test, when ,the model 

predicts a future design value of 82-87 parts per billion (ppb) at one or more sites 

or grid cells.' 

F. State Control Strategy 

ARB is responsible for controlling emissions from mobile sources, consumer 

products, and fuels. ARB'S ongoing mobile source control program will provide 

significant NOx and ROG emission reductions in the Western Mojave Desert and 

Ventura County. Under the existing control program (rules adopted in October 

2006 and earlier), vehicles and equipment operating in California are subject to 

the most stringent tailpipe emission standards in the world. Existing on-road 

vehicle emission controls will decrease ROG and NOx by approximately 36 

' Ibid, U.S. EPA (2007). 
percent in Ventura County by 2012, and by 50 to 60 percent by 2020 in the 

Western Mojave Desert. 

In September, 2007, ARB adopted a comprehensive combination of 

technologically-feasible, cost-effective, and far-reaching measures for motor 

vehicles and other statewide sources as part of the SIP for meeting the 8-hour . 

ozone and fine particulate matter (PM2.5) NAAQS. Table 1.1 lists the measures 

in the 2007 State Strategy, with expected adoption and implementation 

timeframes. 

Table 1.1 - State Strategy Control Measures 

BAR = Bureau of Automotive Repair 

DPR = Department of Pesticide Regulation 

TBD = to be determined 

r 

Proposed New SIP Measures 

Passenger Vehicles 

Smog Check Improvements 

Expanded Vehicle Retirement 

Modifications to Reformulated Gasoline Program 

Trucks 

Cleaner In-Use Heavy-Duty Trucks 

Goods Movement Sources 

Auxiliary Ship Engine Cold Ironing & Clean Technology 

Implementing 

Agency 

BAR 

ARBlBAR 

ARB 

ARB 

E PNAR BI 

Local 

EPNARBI 

Port Truck Modernization ARBlLocal 2007-2008 

Accelerated Intro. of Cleaner Line-Haul Locomotives EPNARB 2007-2008 Starting in 2012 

Off-Road Equipment 

Expected 

Action 

2007-2008 

2008-201 4 

2007 

2008 

2007-2008 

Fuel: 2007 I 

Cleaner In-Use Agricultural Equipment 

Other Off-Road Sources 

New Emission Standards for Recreational Boats 

Expected 

Implementation 

By 2010 

2008-2014 

Phase-In 

Starting 201 0 1 

2010-201 5 

Phase-In 

Starting 2010 

2007-201 0 1 

Phase-In 

ARB 

ARB 

Expanded Off-Road Rec. Vehicle Emission Standards 

Enhanced Vapor Recovery for Above Ground Storage 

Tanks 

2009-201 0 

2009-201 0 

Additional Evaporative Emission Standards 

Area-wide Sources 

TBD 

201 2-201 3 

2007-2008 I 

DPR Pesticide Regulation DPR 2008 2008 

ARB By 2010 2010-201 2 
The 2007 State Strategy includes 2014, 2020, and 2023 emission reductions 

commitments for the South Coast Air Basin, and 2014, 2017, 2020, and 2023 

emission reductions for the San Joaquin Valley Air Basin. In addition to directly 

reducing emissions in these upwind areas, these commitments will indirectly 

improve air quality in downwind areas including the Western Mojave Desert and 

Ventura County. 

G. Transport 

ARB transport assessments and air quality modeling conducted by the SCAQMD 

concur that emissions from the South Coast Air Basin and the San Joaquin 

Valley contribute to ozone exceedances in the Western Mojave Desert and, to a 

lesser extent, in Ventura County. The South Coast and San Joaquin Valley 

populations and emissions dwarf those in the downwind Ventura County and 

Western Mojave Desert ozone nonattainment areas, as shown below. 

Table 1.2 - 2006 Population and Emissions Data 

(tpd, summer planning inventory) 

The significance of pollution transport in each area is discussed in more detail 

later in this report. SIP revisions for the South Coast and San Joaquin Valley 

commit to significant decreases in ROG and NOx emission in these upwind 

areas by 2014. 

Nonattainment Area 

South Coast 

San Joaquin Valley 

Western Mojave Desert 

Ventura County 

H. Environmental Impacts 

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

agency projects be assessed for potential significant environmental impacts. Air 

quality plans are "projects" that are potentially subject to CEQA requirements. 

Both the AVAQMD and the MDAQMD have determined that the air quality plans 

are exempt from CEQA review and have prepared a Notice of Exemption for both 

plans. The VCAPCD's Negative Declaration was adopted in co~junction with the 

District Board's adoption of the 8-Hour Ozone Plan on March 13, 2008. 

I. Legal Authority 

NOx 

972 

650 

172 

68 

Population 

16,143,000 

3,719,000 

769,000 

826,000 

The Act requires states to provide for the attainment of NAAQS. The primary tool 

to be used in the effort to attain NAAQS is a plan that any state with one or more 

ROG 

781 

450 

7 1 

55 
nonattainment areas must develop, which provides for implementation, 

maintenance and enforcement of the standards in the SIP (Section 11 O(a)(l)). 

State law charges the ARB with coordinating State, regional, and local efforts to 

attain and maintain both State and national standards. The direct statutory link 

between ARB and the mandates of the Act is fo1.1nd in Section 39602 of the 

Health and Safety Code (HSC). This provision states: 

"The state board is designated the air pollution control agency for all 

purposes set forth in federal law. 

The state board is designated as the state agency responsible for the 

preparation of the state implementation plan required by the Clean Air Act 

(42 U.S.C., Sec. 7401, et seq.) and, to this end, shall coordinate the 

activities of all districts necessary to comply with that act." 

State law also limits what the ARB may submit as a SIP revision. HSC Section 

39602 goes on to state, 

"Notwithstanding any other provision of this division, the state 

implementation plan shall only include those provisions necessary to meet 

the requirements of the Clean Air Act." 

The California Clean Air Act (CCAA) requires districts to assess the progress the 

County has made toward meeting State ambient air quality standards during the 

previous three years. Ventura County incorporated the triennial assessment in 

the federal 8-hour ozone plan since the control measures implemented to attain 

the federal 8-hour standard will also help attain State air quality standards. ARB 

will exclude any provisions of the Ventura County and Western Mojave Desert 

plans that relate solely to the CCAA requirements from the SIP submittal. 

II. WESTERN MOJAVE DESERT OZONE NONATTAINMENT AREA 

A. Introduction 

The U .S. EPA com bined portions of Los Angeles and San Bernardino counties 

into the Western Mojave Desert (WMD) 8-Hour Ozone Nonattainment Area. The 

WMD includes the northeastern portion of Los Angeles County and the 

southwestern portion of San Bernardino County, both of which are in the Mojave 

Desert Air Basin (Figure 11.1). The AVAQMD has jurisdiction over the Los 

Angeles County portion of the WMD, while the MDAQMD has jurisdiction over 

the San Bernardino County portion of the WMD. The U.S. EPA has classified the 

Western Mojave Desert 8-Hour Ozone Nonattainment Area as a moderate 

nonattainment area with an attainment date of June 2010. 

The Antelope Valley and Mojave Desert AQMDs have adopted separate 

attainment demonstration plans as described in this staff report. To meet federal 
requirements, the two areas adopted identical conformity budgets and RFP plans 

covering the entire WMD nonattainment area. 

1. Mojave Desert Air Quality Management District 

i. Profile of Mojave Desert 

The MDAQMD portion of the Western Mojave Desert nonattainment area 

includes the following San Bernardino County communities: Phelan, Hesperia, 

Adelanto, Victorville, Apple Valley, Barstow, Joshua Tree, Yucca Valley and 

Twentynine Palms. This area covers more than 20,000 square miles and is 

home to over 450,000 people. The area is characterized by hot, dry summers 

and cool winters, with little precipitation. This area also includes portions of the 

National Training Center at Fort Irwin, the Marine Corps Air Ground Combat 

Center, Edwards Air Force Base, the Mojave National Preserve and Joshua Tree 

National Park. 

The primary roadways in the MDAQMD are lnterstate 15, lnterstate 40 and 

lnterstate 395. All of these highways carry a significant amount of transiting 

heavy-duty truck traffic, and lnterstate 15 carries a substantial amount of 

commute traffic into the greater Los Angeles Basin. The district includes railroad 

,track corlnecting the Ports of Los Angeles and Long Beach with the rest of the 

Figure 11.1 -Western Moiave Desert Ozone Nonattainment Area 

and Surroundinq Reqion 

,110juve Desert 

Western Mojave Desert 

-..--....- .6. . 

LC-.- ........ - - ..i-, I:-- - .... i ... 

, N EGO o MPERm couNi 
Continental United States, as well as high-pressure natural gas transmission 

pipelines that deliver most of the natural gas consumed in California. 

The MDAQMD is a growing bedroom community, but does have significant 

mining and military activity. 

ii. Historical Air Quality 

The MDAQMD has experienced a substantial reduction in maximum 8-hour 

ozone concentrations, as displayed in Figure 11.2 (Trona is not within the 

nonattainment area but is shown for comparison). The stations closest to the 

South Coast Air Basin - Phelen, Hesperia, and Victorville - have historically 

recorded the highest historical ozone concentrations. 

Fiqure 11.2 - MDAQMD 8-Hour Ozone Design Value Trend 

2. Antelope Valley Air Quality Management District 

i. Profile of Antelope Valley 

I 

Phelan I 1 \. Trona 

J +Twentynine Palms / 

1 ~V~ctowille 

The Antelope Valley is the desert portion of Los Angeles County. The AVAQMD 

has been designated nonattainment for the 8-hour ozone NAAQS by U.S. EPA 

as a portion of the Western Mojave Desert nonattainment area. The AVAQMD 
portion of the WMD covers 1,300 square miles. Most of the Antelope Valley's 

more than 400,000 residents live in or near the cities of Lancaster and Palmdale. 

The region is characterized by a wide, arid valley with little precipitation. Air 

Force Plant 42 and a portion of Edwards Air Force Base are located within the 

AVAQMD. 

The primary roadways in the Antelope Valley are State Route 14 and State 

Route 18. Both of these arterials carry substantial daily commute traffic from the 

region to the South Coast Air Basin. 

Although the Antelope Valley is largely a bedroom community, aerospace 

development and manufacturing facilities also have a significant local presence. 

ii. Historical Air Quality 

The Antelope Valley has experienced some improvement in 8-hour average 

ozone, as displayed in Figure 11.3. -The "design value" line superimposed on 

Figure 11.3 shows the three-year average value used to determine the starting 

point for air quality planning purposes; it also shows more clearly the trend in 

ozone concentration by minimizing the fluctuations that inay be influenced by 

year-to-year changes in the weather. 

B. Air Qualitv Planning 

I. Air Quality Planning Activities 

The 2008 plans adopted by both the AVAQMD and the MDAQMD were 

developed with input from local interested parties. Each district's plan was 

reviewed by an Air Pollution Advisory Committee made IJ~ of stakeholders 

appointed by the District board that recommended approval of the local plan. 

The AVAQMD published a draft of the Antelope Valley 8-Hour Ozone Plan for 

public review on April 20, 2008; the AVAQMD Board approved the plan at 

noticed public hearing on May 20, 2008. The MDAQMD released its draft plan 

for public review on April 25, 2008; the MDAQMD Board adopted the plan on 

June 9,2008. 
Figure 11.3 - AVAQMD 8-Hour Ozone Design Value Trend 

-- i 

C. Plan Evaluation 

I. MDAQMD Emissions Inventory 

The main sources of NOx emissions in the ozone nonattainment portion of the 

' MDAQMD are heavy-duty diesel trucks, mineral processes and locomotives. The ROG 

inventory is dorrlinated by off-road recreational vehicles, passenger vehicles and 

heavy-duty diesel trucks. The following two tables (Table 11.1 and Table 11.2) show the 

top ter, I4Ox and ROG emission sources in the ozone nonattainment portion of the 

MDAOMD. While NOx emissions are projected to decline through the attainment year, 

ROG errlissions are projected to increase, prirrlarily because of projected growth in offroad recreational vehicle use. 
Table 11.1 - MDAQMD NOx Emissions 

(tpd, summer planning inventory) 

TOP 10 PERCENT OF TOTAL EMISSIONS 1 97% 1 96% 1 

Table 11.2 - MDAQMD ROG Emissions 

(tpd, summer planning inventory' 

Source Category 

OFF-ROAD RECREATIONAL VEHICLES 

PASSENGER VEHICLES 

Passenger Cars 

Light Trucks, Minivans and SUVs 

Medium-Duty Trucks 

HEAVY-DUTY DIESEL TRUCKS 

1 TOTAL OF TOP 10 1 40 1 44 1 

CONSUMER PRODUCTS 

2006 

14 

10 

5 

4 

7 

4 

2. AVAQMD Emissions Inventory 

2020 

23 

4 

7 

2 

7 

2 

3 

TOTAL MDAQMD - Federal Nonattainment area 

TOP 10 PERCENT OF TOTAL EMISSIONS 

Mobile sources provide most of the AVAQMD's NOx emissions, while the 

passenger vehicles, petroleum marketing, and degreasing dominate the district's 

4 

PETROLEUM MARKETING (GASOLINE EVAPORATIVE LOSSES) 3 

LOCOMOTIVES 2 

MOTORCYCLES 

ARCHITECTURAL COATINGS (PAINTS AND THINNERS) 

MINERAL PROCESSES (MINING, CEMENT MANUFACTURING) 

DEGREASING 

Numbers may not add exactly due to rounding 

"Top 10" categories are prioritized by 2006 emissions 

48 

84% 

51 

86% 

2 

1 

1 

1 

2 

2 

1 

1 
ROG inventory. Tables 11.3 and 11.4 show the top ten NOx and ROG emission 

sources in the Antelope Valley, and indicate that total local emissions will 

continue to decline into the region's attainment year, although more slowly for 

ROG. 

Table 11.3 - AVAQMD NOx Emissions 

(tpd, summer planning inventory) 

I RESIDENTIAL FUEL COMBUSTION ]>I [>I 

Source Category 

OFF-ROAD EQUIPMENT (CONSTRUCTION ANDMEING) 

PASSENGER VEHICLES 

Passenger Cars 

Light Trucks, Minivans and SUVs 

Medium-Duty Trucks 

HEAW-DUTY DIESEL TRUCKS 

LOCOMOTIVES 

MANUFACTURING AND INDUSZAL (BOILERS, IC ENGINES) 

AIRCRAFT 

COMMERCIAL AND DELIVERY GASOLINE TRUCKS 

SERVICE AND COMMERCIAL (BOILERS, IC ENGINES) 

Table 11.4 - AVAQMD ROG Emissions 

(tpd, summer planning inventory) 

266 

11 - 

6 

2 

2 

1 

5 

2 

1 

1 

1 

>I 

SCHOOL BUSES 

-- TOTALOFTOP 10 

TOTAL AVAQMD 

TOP 10 PERCENT OF TOTAL EMISSIONS - 

/ Source Category - [ 2006 1 2020 1 

2020 

5 

2 

1 

1 

1 

2 

2 

1 

1 

> 1 

>1 

>I 

26 

28 

94% 

>I 

14 - 

16 

89% 

Passenger Cars 

Light - Trucks, Minivans and SUVs 

Medium-Duty Trucks 

PETROLEUM MARKETING (GASOLINE EVAPORATIVE LOSSES) 

4 

3 

1 

3 

2' 

2 

1 

3 

3 

3 

1 

1 

1 

1 

1 

1 

19 

22 

85% 

DEGREASING 12 

CONSUMERPRODUCTS 12 

OFF-ROAD EQUIPMENT (CONSTRUCTION AND MINING) / - 1 

Numbers may not add exactly due to round~ng 

"Top 10" categories are prioritized by 2006 emissions 

ARCHITECTURAL COATINGS (PAINTS AND THINNERS) - 

COATINGS (PAINTS AND THINNERS - NON ARCHITECTURAL) 

AIRCRAFT 

MOTORCSLES 

OFF-ROAD EQUIPMENT (LAWN AND GARDEN) 

TOTALOFTOP 10 

TOTALAVAQMD 

TOP 10 PERCENT OF TOTAL EMISSIONS 

' 1 

1 

1 

1 

1 

20 

23 

84% 
3. Control Measures 

i. Mojave Desert Air Quality Management District 

a) Existing Control Measures 

The MDAQNID has in place Reasonably Available Control Technology (RACT) 

requirements for the majority of sources (including gasoline dispensing vapor 

control), as well as a New Source Review program with a 25 ton per year major 

source level and a 1.3:l offset ratio requirement. The MDAQMD recently 

adopted federal RACT rules for ship surface coating,' glass man~facturing,~ and 

polyester resin operation^.^ Table 11.5 shows the emission trends for the Mojave 

Desert. 

Table 11.5 - MDAQMD Baseline Emission Trends 

(tpd, summer planning inventory) 

Numbers may not add due to rounding 

b) Proposed Control Measures 

The MDAQMD is not proposing to adopt additional control measures for direct 

ozone precursor reduction purposes. With MDAQMD's proposed adoption of the 

three federal RACT rules shown below, the district will fulfill the Act's RACT 

adoption requirements. The MDAQMD is also analyzing the feasibility of 

adopt; 19 or amending 18 additional rules under the CCAA's "all feasible 

measl;;esn mandate. 

Table 11.6 - MDAQMD RACT Adoption Schedule 

I Publiclv Owned Treatment Works I Federal RACT I 312009 

Rule Title 

Residential S~ace Heaters 

-~ - ~ ~~ ~ I - ~- I Graphic Arts Amendment I Federal RACT 1 9/22/2008 

' "Rule 11 06 - Marine Coating Operations." amended October 23, 2006 

"Rule 1165 - Glass Melting Furnaces," amended January 28,2008 

"Rule 1162 - Polyester Resin Operations," August 27, 2007 

Rule Nature 

Federal RACT 

Adoption Date 

112009 
ii. Antelope Valley Air Quality Management District 

a) Existing Control Measures 

The AVAQMD has in place RACT requirements for the majority of sources 

(including gasoline dispensing vapor control), as well as a New Source Review 

program with a 25 ton per year major source level and a 1.3:l offset ratio 

requirement. Table 11.7 shows the emission trends for the Antelope Valley. 

Table 11.7 - AVAQMD Baseline Emission Trends 

(tpd, summer planning inventory) 

Numbers may not add exactly due to rounding 

TOTAL 

c) Proposed Control Measures 

The AVAQMD is not proposing to adopt additional control measures for direct 

ozone precursor reduction purposes. With AVAQMD1s proposed adoption of the 

three federal RACT rules shown below, the district will fulfill the Act's RACT 

adoption requirements. The AVAQMD is also is reviewing rules for 13 source 

categories under ,the CCAA1s "all feasible measures" mandate. 

23 

Table 11.8 - AVAQMD RACT Adoption Schedule 

I Rule Title I Rule Nature I Ado~tion Date 1 

22 

4. State Strategy 

4% 

Internal Combustion Engines 

Fugitive Dust 

Aaricultural Operations 

The 2007 State Strategy is expected to reduce combined ROG and NOx 

emissions in the Western Mojave Desert by approximately 43 tons per day in 

2020. It is already reducing emissions in the South Coast and San Joaquin 

Valley. In the 2007 State Strategy, ARB has committed to achieve specified 

emission reductions in the South Coast and San Joaquin Valley in 2014, 2020, 

28 

Federal RACT 

Federal RACT 

Federal RACT 

112009 

312009 

1211 612008 

16 -43% 
and 2023, as well as a 2017 emission reduction goal specific to the San Joaquin 

Valley. 

5. Contingency Measures 

The 2007 State Strategy is projected to continue to reduce emissions beyond the 

Desert's 2020 attainment year. Statewide, the strategy is projected to reduce 

NOx emissions by an additional 40 percent, and ROG emissions by an additional 

20 percent, from 2020 through 2023. In addition, the State has committed, with 

the SCAQMD and SCAG, to develop additional, far-reaching strategies needed 

to bring the South Coast Air Basin into attainment with the 8-hour ozone standard 

by 2023. The emission commitments in the 2007 State Strategy, and the 

controls that will be developed to ensure attainment of the ozone standard in the 

State's extreme areas, will provide both direct and indirect reductions beyond 

those included in the Western Mojave Desert's projection of attainment in 2020. 

Formally, the MDAQMD has committed to request implementation of the 

Enhanced Smog Check Program should a contingency measure be triggered. 

Implementation is estimated to occur within one year once the contingency 

measure is triggered. The Enhanced Smog Check Program is already being 

irr~pleniented in the AVAQMD. 

6. Reasonable Further Progress Demonstration 

The Act requires areas classified as moderate or greater to demonstrate that 

their plans will result in steady progress towards attainirlg ,the federal standard. 

This RFP requirement ensures that areas will not delay implementation of 

emission control programs until immediately before the attainment date. As a 

serious nonattainment area, the Western Mojave Desert must demonstrate an 

average three percent per year reduction in ozone precursors, relative to the 

2002 base year, on each milestone year through the attainment year. 

Where both ROG and NOx err~issions have been shown to contribute to high 

ozone levels, the Act allows NOx emission reductions to be used to augment 

ROG emission reductions in order to demonstrate RFP. In transport-impacted 

areas, the Act also allows upwind emissions to be taken into account when 

assessing RFP. 

The locally adopted plan includes a demonstration that the rate of progress 

projected for the Western Mojave Desert meets the Act's requirements. The 

RFP demonstration takes into account projected emissions for upwind areas 

within 100 kilometers of the Western Mojave Desert - specifically, emissions 

generated in Orange County, and in the South Coast Air Basin portions of Los 

Angeles and San Bernardino counties - as allowed by U.S. EPA guidance. As 

required by the Act, emission reductions attributable to the federal Motor Vehicle 
Control Program (MVCP) as it existed in 1990 have been excluded from the RFP 

calculations. This adjustment is shown as the "CA MVCPIRVP" adjustment. The 

RFP demonstration uses baseline emissions only; it does not rely on any 

emission reductions from the 2007 State Strategy. 

7. Transportation Conformity Budgets 

A transportation conformity emissions budget is the level of emissions from 

on-road motor vehicles that ensures an area makes progress toward clean air 

and ultimately meets air quality standards by the mandated deadline. Under the 

Act, transportation activities that receive federal funding or approval must be 

found to be fully consistent with a SIP that demonstrates attainment of the 

NAAQS. The MDAQMD and AVAQMD each adopted identical transportation 

conformity budgets for the Western Mojave Desert Ozone Nonattainment Area. 

The emission budgets established in this plan fulfill the requirements of the Act 

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

with progress towards, and attainment of, the 8-hour ozone NAAQS. 

Table 11.9 - Western Mojave Desert Transportation Conformity Budget 

(tpd, summer planning inventory) 

-- 1 On-Road Mobile* ( 22.7 1 82.0 [ 19.8-1 705 1 16.6-1 549 1 14.57 43.1 ( 13.2 1 35.4 1 

Using EMFAC2007 " Reductions from adopted rules not reflected in EMFAC 

"' Budget is obtained by rounding up to the nearest ton 

State Strategy Reductions 

Conformity Budget*** 

D. Attainment Demonstration 

1. Modeling Results 

-- 

23 

The Southern California regional photochemical modeling used to assess 

attainment of the 8-hour ozone standard in both Ventura County and the Western 

Mojave Desert is summarized in Part I of this report. The following table 

(Table 11.10) shows the design value for each monitoring site in the Western 

Mojave Desert, based on 2001-2003 air quality data, and the projected future 

values with implementation of the 2007 State Strategy and local emission 

reduction commitments included in the SCAQMD1s 2007 Air Quality Maintenance 

Plan. 

-- 

78 

-- -- 

20 1 67 

-3.4 

14 

-15.3 

36 

-2.5 

12 

-14.1 

26 

-1.7 -7.4 

12 25 
Table 11.10 - Ozone Attainment Demonstration 

Projected Design 

Baseline (2001 -2003) Value 

Monitor Location Design Value 201 2 / 2017 / 2020 

Lancaster 100.7 86.5 1 79.7 1 74.0 

Phelan 

Hesperia 106.3 1 

Barstow 87.6 79.7 73.2 79.5 

Twentynine Palms 86.7 77.3 65.8 82.2 

The modeling results indicate that it will not be possible to attain the 8-hour 

ozone NAAQS by 2010, the moderate area attainment deadline. The 201 7 

design values projected for Phelan and Hesperia exceed the standard, and the 

projected 88.7 ppb value in Hesperia exceeds the 87 ppb WOE attainment 

demonstration cutoff. The photochemical modeling projects attainment in 2020, 

which is consistent with the June 15, 2021 attainment deadline for severe-17 

nonattainment areas. 

2. Weight of Evidence Analysis 

ARB staffs detailed WOE assessments for the Western Mojave Desert support 

the determination that this area will attain the 8-hour ozone NAAQS by the 2020 

deadline for severe-17 areas. The ARB WOE assessments for the Mojave 

Desert and Antelope Valley AQMDs include the following analyses: 

a. Photocherr~ical modeling; 

b. Air quality trends analyses; 

c. Emissions and meteorological data; 

d. Evaluation of other air quality indicators; and 

e. Additional air quality modeling. 

E. Staff Recommendations 

As described in this report, ARB staff has reviewed the 2008 8-Hour Ozone 

Attainment Plan for the Western Mojave Desert Nonattainment Area (2008 

Ozone Plan), and consulted with District staff during this review. 

ARB staff finds that the 2008 Ozone Plan meets applicable requirements and 

concludes that implementation of this plan would reduce ozone levels throughout 

the Western Mojave Desert, thereby resulting in attainment of the 8-hour ozone 

NAAQS by June 2021. Therefore, we recommend that the Board take the 

following actions: 
1) Adopt the 2008 Ozone Plan as a revision to the California SIP, including 

the control strategy, emission inventories, attainment demonstration, and 

motor vehicle emission budgets. 

2) Direct the Executive Officer to submit the plans to U.S. EPA as a revision 

to the California SIP. 

Ill. VENTURA COUNTY OZONE NONATTAINMENT AREA 

A. Introduction 

On June 15, 2004, U.S. EPA designated Ventura County a moderate 

nonattainment area based on monitored ozone values from the previous 

three years. Moderate ozone nonattainment areas are required to attain federal 

8-hour ozone NAAQS by June 15,2010. On January 23,2008, the VCAPCD 

requested a reclassification to a serious nonattainment area since the results of 

photochemical modeling indicated that Ventura County would not attain the 

standard by 201 0, and would need additional time to achieve the necessary 

emission reductions. U.S. EPA approved the VCAPCD request effective 

June 19,2008. 

On May 13,2008, the VCAPCD adopted the 2007 8-Hour Ozone Plan. ARB 

staff reviewed the 2007 Ozone Plan and is recommending that the Board 

approve the 2007 Ozone Plan and submit it to U.S. EPA as a revision to 

California's SIP. 

1. Profile of Ventura County 

Ventura County is located west of Los Angeles County and is bordered by Kern 

County to the north, Santa Barbara County to the west, and the Pacific Ocean to 

the southwest. It includes the Channel Islands National Park and serves as a 

gateway to this five-island marine sanctuary. Ventura County's economic base 

includes agriculture, biotechnology, telecommunications, and manufacturing 

activities, as well as tourism, military testing, and development. Port Hueneme 

serves as the western U.S. distribution network for many imported vehicles, and 

houses the largest refrigerated fruit terminal on the West Coast. 

Ventura County has a combination of undeveloped and agricultural lands, as well 

as developed urban areas. The Los Padres National Forest accounts for 860 

square miles of the northern portion of the County (46 percent of the County's 

land mass). The County's mountains, valleys and seashore give the area six 

different microclimates, more than any other county in the nation. 
Elevated smog occurs in Ventura County from May through October, when high 

temperatures and stable atmospheric conditions favor ozone formation. Ozone 

generally reaches peak levels by mid-afternoon and, along with ozone 

precursors, is often blown inland by the prevailing winds. As a result, inland 

areas such as Sirr~i Valley, Thousand Oaks, Ojai, Fillmore, and Piru continually 

have higher ozone levels and more days in exceedance of the federal ozone 

standard than the County's coastal areas. 

Ozone in the Ventura County Nonattainment Area is caused by bath locally 

generated emissions and transport from the South Coast; the Los Angeles 

County portion of the South Coast Air Basin lies directly east of Ventura County. 

In-port and offshore emissions from shipping-related operations also impact 

Ventura County's air quality. The federal 8-hour ozone nonattainment area 

includes all of Ventura County except the Channel Islands. 

2. Historical Air Quality 

All indicators reviewed in the locally adopted plan show significant improvement 

in Ventura County's air quality over the last two decades. The number of days 

over the 8-hour ozone NAAQS decreased by 85 percent, while other key 

indicators including the design value (an average of the fourth highest value in 

each of three consecutive years) declined by approximately 30 percent. 

As recently as ten years ago, the County's design value was approximately 

40 percent above the standard, and design values at each of the County's seven 

monitoring sites exceeded the federal standard. By 2006, five Ventura County 

monitoring sites met the federal standard: El Rio, Emma Wood State Beach, 

Thousand Oaks, Ventura County (West Casitas Pass Road), and Piru. At 

0.09 ppm, the 2006 design values at the remaining nonattainment sites, Ojai and 

Simi Valley, are less than ten percent above the standard, as shown in 

Figure 111.1. 
Finure 111.1 - 8-Hour Ozone Values for Simi Valley and Oiai Valley 

0.16 

1 -cSim~ Vallev +Oiai 

Three Year Average of Fourth Highest Ozone Concentration, Truncated at 

Three Decimal Places. (Source: California Air Resources Board) 

" " " 

Federal Eight-hour Ozone Standard 

State Eight-hour Ozone Standam' 

Oo7 rC. Air Qualitv Planning 

1. Recent Air Quality Planning Activities 

The VCAPCD held a public workshop and provided two public review periods in 

the development of its current 8-hour ozone plan. The first draft was available for 

public comment from March I, 2007 to April 6, 2007, and a second draft was 

available for public comment from March 25, 2008 to April 24, 2008. On 

May 13,2008, the VCAPCD approved the 2007 8-hour ozone plan and negative 

declaration for the plan at a duly noticed local heal-ing. 

D. Plan Evaluation 

1. Emissions Inventory 

Mobile sources form the bulk of Ventura County's NOx inventory, with ships and 

boats vying with on-road mobile sources for the top spot (Table Ill. 1). With ROG 

emissions from mobile sources projected to decline, area sources are becoming 

an increasingly significant portion of the ROG inventory (Table 111.2). 
Table 111.1 - Ventura County NOx Emissions 

(tpd, summer planning inventory) 

Numbers may not add due to rounding 

"Top 10" categories are prioritized by 2006 emissions 

Source Category 

SHIPS AND COMMERCIAL BOATS 

Commercial Harbor Craft 

Ocean Going Vessels 

PASSENGER VEHICLES 

Passenger Cars -- 

AND MINING) 

TOTALVCAPCD 

TOP 10 AS A PERCENT OF TOTAL EMISSIONS 

Table 111.2 - Ventura County ROG Emissions 

(tpd, summer planning inventory) 

TOTALOFTOP 10 1 61 1 50 1 

2006 

16 

3 

13 

12 

4 

1 

68 1 58 

90% 1 87% 

2012 

20 

3 

17 

7 

2 

OFF-ROAD EQUIPMENT (OTHER) 

1 FARM EQUIPMENT (COMBINES AND TRACTORS) 

COMMERCIAL AND DELIVERY GASOLINE TRUCKS 

AGRICULTURAL IRRIGATION PUMPS 

LOCOMOTIVES 

ELECTRIC UTILITIES 

Source Category 

PASSENGER VEHICLES 

Passenger Cars 

Light Trucks, Minivans and SUVs 

Medium-Duty Trucks 

CONSUMER PRODUCTS 

Numbers may not add exactly due to rounding 

"Top 10" categories are prioritized by 2006 emissions 

5 

2 

8 

8 

ARCHITECTURAL COATINGS (PAINTS AND 'THINNERS) 

OFF-ROAD EQUIPMENT (LAWN AND GARDEN) 

OFF-ROAD RECREATIONAL VEHICLES 

DEGREASING 

COATINGS (PAINTS AND THINNERS - NON ARCHITECTURAL) 

OIL AND GAS PRODUCTION (EVAPORATIVE LOSSESIFLARING) 

TOTAL OF TOP 10 

TOTAL VCAPCD 

TOP 10 AS A PERCENT OF TOTAL EMISSIONS 

5 

3 

3 

2 

2 

2 

PESTICIDES 5 

RECREATIONAL BOATS 4 

2006 

13 

7 

4 

2 

5 

4 

2 

2 

0 

1 

2 

2012 

8 

4 

3 

1 

5 

3 

3 

3 

2 

2 

2 

42 

54 

77% 

3 

2 

3 

2 

2 

2 

35 

48 

73% 
The SIP must provide for sufficient emission reductions in 2012 in order to 

demonstrate attainment in 201 3. -The following table (Table 111.3) summarizes 

emission reductions between 2006 and 2012. Emissions of ROG are predicted 

to decline by 12 percent and NOx by 15 percent, with the largest reductions 

coming from on-road mobile sources. 

Table 111.3 - Ventura County Baseline Emissions 

with Measures Adopted as of 2006 

(tpd, summer planning inventory) 

Numbers may not add due to rounding 

i. Emission Reduction Credits 

Source Category 

Stationary and 

Area-wide 

On-Road Motor 

Vehicles 

- 

Off-Road Vehicles and 

Equipment 

, TOTAL 

Federal New Source Review (NSR) rules require new and modified major 

stationary sources that increase emissions in amounts exceeding specified 

thresholds to provide emission reduction offsets to mitigate the emissions growth. 

Emission reduction offsets represent either on-site emission reductions or the 

use of banked emission reduction credits (ERCs). Table 111.4 shows the ERCs 

registered with the VCAPCD for future use as offsets. 

NOx 

Table 111.4 - Ventura County Emissiorr Reduction Credits 

ROG 

2006 

7.7 

23 

37 

68, 

ERCs Issued 2002 and Earlier, tpd 

2006 

24 

15 

15 

, 54 

Pollutant 1 ERCTO~~I 

2012 

7.6 

14 

35 

58 

1 NOx 1 0.51 1 

Change 

2% 

-36% 

-4 % 

, -15% 

2012 

25 

10 

13 

, 48 

Change 

3% 

-36% 

-12% 

, -12% , 

2. Control Measures 

I ROG 

Currently adopted controls under district, State, and federal jurisdiction will 

provide continued reductions in ozone precursors for the 201 3 attainment 

deadline. VCAPCD's 2007 Plan also commits to the development of four local 

control measures. 

1.67 
i. Existing Control Measures 

Stationary Source Control Measures 

The Act requires nonattainment areas to demonstrate that they have adopted 

rules at least equivalent to RACT. The VCAPCD adopted its RACT SIP in June 

2006. The RACT SIP found that all VCAPCD rules that apply to ozone precursor 

emissions fulfill RACT requirements for the 8-hour ozone NAAQS. The RACT 

SIP also found that all sources subject to Control Technology Guidelines (CTG) 

meet RACT. 

Local air districts are responsible for controlling emissions from most stationary 

and area-wide sources. Most of the VCAPCD rules were fully implemented by 

2005 and are reflected in the base year inventory used to develop this plan. The 

VCAPCD's NSR cutoffs of five tons per year for both NOx and ROG are already 

below the serious nonattainment area threshold of 50 tons per year as specified 

in the Act, and the County's 1.3:l offset ratio exceeds the required minimum 

1.2: 1 offset ratio. 

Transportation Source Measures 

U.S. EPA identified 16 transportation co~itrol measures (TCM) categories that 

must be evaluated as part of a RACM demonstration. TCMs include options for 

reducing vehicle use or conditions that ,lead to higher vehicle emissions. The 

VCAPCD, along with SCAG and the Ventura County Transportation Commission, 

reviewed the measures to determine their feasibility. 

ii. Proposed Control Measures 

As part of its plan, the VCAPCD committed to consider the adoption of four 

additional measures, three of which are proposed to be implemented by the 201 2 

attainment year. If adopted, these measures will provide reductions that were 

not included in the photochemical modeling. 

Table 111.5 - Ventura Countv Proposed District Control Measures 

District Rule 

74.18 

74.12 

74.2 

74.29 

Control Measure 

Motor Vehicle and Mobile 

Equipment Coating Operations 

Surface Coating of Metal Parts 

TBD = to be determined 

- 

and Products 

Architectural Coatings 

Soil Decontamination Operations 

Adoption 

2008 

2008 

Implementation 

201 0 

2009 

TBD 

2008 

TBD 

2009 
3. State Control Strategy 

ARB'S emission reduction commitments in the 2007 State Strategy specify total 

reductions to be achieved in the South Coast and San Joaquin Valley Air Basins 

in 2014, 2020, and 2023 and, for the San Joaquin Valley only, in 2017. The 

irr~plementation of the measures identified to meet these commitments is 

expected to reduce combined ROG and NOx err~issions in Ventura County by an 

approximately eight tons per day in 2012. These expected emission reductions 

were not included in the attainment demonstration modeling. 

4. Contingency Measures 

ARB'S ongoing mobile source control program will provide emission reductions 

beyond Ventura County's attainment year that will serve as a contingency 

measure should the County fail to attain the ozone NAAQS in 2012, as shown 

below in Table 111.6. Emissions in upwind areas are also expected to decrease 

during this period: baseline ROG and NOx emissions from all sources are 

expected to decrease by three and eight percent, respectively, from 2012 

through 2014. 

Table 111.6 - Ventura County Mobile Source Emissions 

'Off-road emissions extend to 100 nautical miles offshore. 

Source Category 

On-Road Mobile 

Off-Road Mobile* 

Total 

5. Reasonable Further Progress Demonstration 

Federal law specifies that each ozone nonattainment area must demonstrate 

ongoing emission redl~ctions relative to the base year (2002). Federal law 

requires a three percent per year reduction in VOC emissions, and does not 

allow credit to be taken for pre-1990 federal motor vehicle control programs. 

Where both VOC and NOx emissions have been shown to contribute to high 

ozone levels, the Act allows NOx emission reductions to augment VOC emission 

reductions in order to demonstrate RFP. 

ROG 

2012 

10 

13 

23 

NOx 

2012 

15 

35 

50 

2013 

8 

13 

21 

2014 

7 

13 

20 

2013 

13 

35 

48 

2014 

11 

35 

47 
The Ventura County plan includes an RFP demonstration that meets the Act's 

requirements. The analysis indicates that the adopted measures from ARB's 

mobile source program will provide emissions reductions beyond those needed 

for Ventura County's RFP demonstration. Emissions generated in the South 

Coast Air Basin portion of Los Angeles County were included in Ventura 

County's RFP demonstration as allowed by U.S. EPA guidance. As part of the 

RFP demonstration, the VCAPCD will rely on a portion (three percent) of surplus 

NOx reductions set aside in 2008 for RFP contingency purposes for all milestone 

years. 

In September, 2007 the Board adopted revisions to the Pesticide Element of the 

1994 Ozone SIP for the Ventura County Nonattainment Area. The revisions 

provided a limited-term substitution of surplus ROG reductions from other 

measures in ARB's strategy as a substitution for part of the 1994 Department of 

Pesticide Regulation (DPR) pesticide emission reduction commitments. DPR 

recently adopted fumigant regulations that will make up the shortfall by 2012. 

Since the regulations were or~ly recently approved, and are still in litigation, the 

benefits are not included in the inventory. The Ventura County RFP calculations 

do not include any reductions from the DPR regulations. Consequently, the 

pesticide reductions are not needed to meet RFP or attainment. We expect that 

future updates to the inventory will include the benefits of the regulations as DPR 

reports it actual emissions with the regulations in place. 

6. Transportation Conformity Budgets 

Normally, conformity budgets are set with RFP Plans. However, U.S. EPA is 

revising its RFP regulations for areas such as Ventura County where air quality is 

impacted by air pollution transported from upwind regions. Until those revisions 

are complete, U.S. EPA will not approve conformity budgets for such areas. 

To keep the transportation planning process moving, ARB staff prepared early 

progress plans (EPP) for the sole purpose of establishing transportation 

conformity emission budgets for nonattainment areas affected by U.S. EPA's 

revisions. ARB held a public 30-day comment period for the EPPs which were 

approved by the Board in February, 2008 and deemed adequate by U.S. EPA in 

April, 2008. 

Ventura County's 2007 AQMP includes the following conformity budget for a 

serious 8-hour ozone nonattainment area. Table 111.7 summarizes the motor 

vehicle emissions budget for transportation conformity purposes under a serious 

federal 8-hour ozone classification. Once U.S. EPA approves the budget, it will 

supersede the EPP's conformity budget and serve as the conformity emissions 

budget for future transportation conformity determinations in Ventura County. 
Table 111.7 - On-Road Motor Vehicle Emission Budgets 

(tpd, summer planning inventory) 

Using EMFAC2007 ** Reductions from adopted rules not reflected in EMFAC 

"' Budget is obtained by rounding up to the nearest ton 

On-Road Mobile* 

Adjustments to Baseline** 

State Strategy Reductions 

Conformity Budget*** 

E. A ttainment Demonstration 

The Southern California regional photochemical modeling used to assess 

attainment of the 8-hour ozone standard in Ventura County is summarized in 

Part I of this report. The plan provides a comprehensive description of the 

modeling approach and inputs used in the model. 

12.7 

0.0 

13 

1. Modeling Results 

Using the emissions inventory reflecting a controlled emissions scenario for the 

projected year 2012, the simulation results were used to calculate 8-hour ozone 

design values. Table 111.8 shows the design value for each monitoring site in 

Ventura County, based on 2001-2003 air quality data, and the projected future 

values with implementation of the 2007 State Strategy and local emission 

reduction commitments made by the SCAQMD included in its 2007 AQMP. 

20.0 

-0.4 

20 

Table 111.8 - Ozone Attainment Demonstration 

(PPm) 

10.6 

0.0 

11 

I Ojai I .094 I .087 . I 

I Site 

Baseline Design Value / (2001 -2003) 

1 ~iru* I .088 I .076 1. 

16.3 

-0.4 

16 

Projected Design Value 

(201 2) 

2. Weight of Evidence Analysis 

10.0 

0.0 

-1.2 

9 

Simi Valley 

In Table 111.8, the high value of .087 ppm at Ojai in 2012 is within the range of 

values for which U.S. EPA guidelines allow the use of supplemental analyses to 

demonstrate attainment. ARB staff prepared a WOE analysis for Ventura County 

that assessed air quality trends, emission trends, the special distribution of ozone 

15.21 

-0.4 

-2.5 

13 

* The Piru monitoring site attained the standard in 2006 

.092 .084 
concentrations througho~~t the County, and precursor concentrations measured 

at the two Photochemical Assessment Monitoring Stations (PAMS) in Ventura 

County. The WOE concluded that Ventura County would attain the federal 

8-hour ozone standard by 201 2. 

F. Staff Recommendations 

As described in this report, ARB staff has reviewed the 2007 Ventura County 

8-Hour Ozone Plan, and consulted extensively with VCAPCD staff during this 

review. ARB staff finds that the plan meets applicable requirements and 

concludes that implementation of this plan would reduce ozone levels throughout 

Ventura County, thereby resulting in attainment of the 8-hour ozone standard by 

June, 2013. Therefore, we recommend that the Board take the following actions: 

(1) Adopt the 2007 Ventura County 8-Hour Ozone Plan as a revision to the 

California SIP, including the control strategy, emission inventories, 

attainment demonstration, and motor vehicle emission budgets. 

(2) Direct the Executive Officer to submit the plan to U.S. EPA as a revision to 

the California SIP.