# MDAQMD 

# Federal 8-Hour Ozone Attainment Plan (Western Mojave Desert Non-attainment Area)

Adopted on: June 9, 2008

Mojave Desert Air Quality Management District

14306 Park Avenue Victorville, CA 92392-23102 This document was prepared by the MDAQMD Pla nning, Rule-making and Grants section, with input from the entire MDAQMD staff. Significan t portions of this document were prepared by, or are based on work done by, the California Air Resources Board and the South Coast Air Quality Management District staffs. The MDAQ MD staff greatly appreciates the assistance of those agencies in the prep aration of this document.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 i Table of Contents List of Tables................................................................................................................. .......... ii List of Figures................................................................................................................ ......... ii Abbreviations and Acronyms ................................................................................................. iii Executive Summary.............................................................................................................. ........ 1 CHAPTER 1 – Introduction and Background........................................................................... 3

Introduction................................................................................................................... .............. 5 Purpose ........................................................................................................................ ............5 Background..................................................................................................................... ............ 5 Regulatory History............................................................................................................. ......5 Regional Ozone Planning Chronology ....................................................................................6 Statement of Issues............................................................................................................ .......6 Federal Legal Requirements....................................................................................................6 Pollutant Description and Health Effects................................................................................7 Setting ........................................................................................................................ ..............8 Ozone Trend.................................................................................................................... .........8

CHAPTER 2 – Emission Inventories ........................................................................................ 11

General ........................................................................................................................ ..........13 Modeled Emission Inventory and Sub-Region Inventory.......................................................13 Federal Ozone Non-Attainment Area Base Year Emission Inventory...................................14 Future Year Emission Inventories .........................................................................................14 CHAPTER 3 – Control and Contingency Measures ............................................................... 17 Existing Control Measures ....................................................................................................19 Proposed Control Measures ..................................................................................................19 State Control Measures......................................................................................................... .19 Local Rule Adoption Schedule...............................................................................................23 Contingency Measures........................................................................................................... 24 Required Progress .............................................................................................................. ...24 Controlled Emission Inventories............................................................................................25 Conformity Budgets ............................................................................................................. ..25

CHAPTER 4 – Attainment Demonstration.............................................................................. 27

Attainment Demonstration....................................................................................................... . 29 Modeling Approach Overview ...............................................................................................29 Modeling Domain ................................................................................................................ ..30 Model Inputs ................................................................................................................... .......30 Modeling Results............................................................................................................... .....30 ARB Weight of Evidence Assessment.....................................................................................31 Appendices..................................................................................................................... .............. 33 Appendix A - Base Year Emission Inventory....................................................................... A - 1 Appendix B - Future Year Emission Inventories.................................................................. B - 1 Appendix C –Transportation Conformity Budgets............................................................... C - 1 Appendix D - Annual Ambient Mon itoring Data Summary ................................................ D - 1ii MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Appendix E – ARB Weight of Evidence Assessment ...........................................................E - 1



### List of Tables Table 1 – 2002 Base Year Summary ............................................................................................ 14 Table 2 – Expected Emission Reductions from Proposed New SIP Measures ............................ 23 Table 3 - Reasonable Further Progress for the WMDONA.......................................................... 25 Table 4 - Transportation Conformity Budget (FONA)................................................................. 26 Table 5 - 2020 Federal Ozone A ttainment Demonstration........................................................... 31



### List of Figures Figure 1 - Federal 8-Hour Oz one Design Value Trend .................................................................. 9 Figure 2 - 2002 Base Year Pie Charts (FONA) ............................................................................ 14 Figure 3 - Forecasted VOC Emission Inventories (FONA).......................................................... 15 Figure 4 - Forecasted NO x Emission Inventories (FONA)........................................................... 16MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 iii 

### Abbreviations and Acronyms AQAP................. Air Quality Attainment Plan AQMA ............... Air Quality Management Area AQMP................ Air Quality Management Plan CALGRID.......... California Photochemical Grid Model CARB................. California Air Resources Board CCAA ................ California Clean Air Act CO...................... Carbon Monoxide ERC.................... Emission Reduction Credit FCAA................. Federal Clean Air Act FMVCP.............. Federal Motor Vehicle Control Program FONA................. Federal Ozone Non-attainment Area MDAQMD......... Mojave Desert Air Qu ality Management District MPR ................... Model Performance Ratio NAAQS.............. National Ambient Air Quality Standard NO X .................... Oxides of Nitrogen NSR.................... New Source Review O 3 ....................... Ozone RACT................. Reasonably Availa ble Control Technology ROG ................... Reactive Organic Gases ROP.................... Rate of Progress RRF.................... Relative Reduction Factor SAAQS .............. State Ambient Air Quality Standard SBCAPCD ......... San Bernardino County Ai r Pollution Control District SCAB ................. South Coast Air Basin SCAG................. Southern California Association of Governments SCAQMD .......... South Coast Air Qual ity Management District SCAQS87........... 1987 Southern California Air Quality Study SCOS97.............. 1997 Southern California Ozone Study SDMAQMA....... Southeast Desert Modifi ed Air Quality Management Area SSAB.................. Salton Sea Air Basin tpaad................... Tons per Annual Average Day tposd................... Tons per Ozone Seasonal Day UAM .................. Urban Airshed Model USEPA............... United States Environmental Protection Agency VMT................... Vehicle Miles Traveled VOC ................... Volatile Organic Compounds WMDONA......... Western Mojave Desert Ozone Non-attainment Areaiv MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 1 

## Executive Summary The United States Environmental Protection Ag ency (USEPA) designated the Western Mojave Desert non-attainment area as non-attainment fo r the 8-hour ozone National Ambient Air Quality Standard (NAAQS) pursuant to the provisions of the Federal Clean Air Act (FCAA). A portion of the Mojave Desert Air Quality Management District (MDAQMD) is in cluded in the Western Mojave Desert non-attainment ar ea. The MDAQMD has adopted State and Federal attainment plans for the region within its jurisdiction. Th e most recent such plan that was approved by USEPA is the MDAQMD 2004 Ozone Attainment Plan adopted in 2004. The most recently adopted State plan is the 1996 Triennial Revi sion to the 1991 Air Quality Attainment Plan.

The MDAQMD has reviewed and updated all elemen ts of the ozone plan. The portion of the MDAQMD designated as a Federal 8-hour ozone non-attainment area (FONA) will be in attainment of the 8-hour NAAQS for ozone by 2021.

This document includes the latest planning a ssumptions regarding popul ation, vehicle activity and industrial activity. This document addre sses all existing and forecast ozone precursorproducing activities within the MDAQMD through the year 2020. This document includes all necessary information to allow general and transp ortation conformity findings to be made within the MDAQMD.2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 3 

## CHAPTER 1 – Introduction and Background

Purpose Regulatory History Statement of Issues Federal Legal Requirements State Legal Requirements Pollutant Descriptions Health Effects Setting Ozone Trend4 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 5 

### INTRODUCTION

Purpose The Western Mojave Desert non -attainment area (as defined in 40 CFR 81.305) was designated non-attainment for the NAAQS for ozone by USEPA on April 15, 2004. The Western Mojave Desert Ozone Non-attainment Area (WMDONA) includes part of the San Bernardino County portion of the MDAQMD, as well as the Antelope Valley portion of Los Angeles County. The MDAQMD has experienced ambient ozone concen trations in excess of the 8-hour ozone NAAQS. This document: (1) demonstrates that the MDAQMD will meet the primary required Federal ozone planning milestones, attainment of the 8-hour ozone NAAQS by June 2021; (2) presents the progress the MDAQMD will make towards meeting all required ozone planning milestones; and (3) discusses the newest 0.075 part per million 8-hour ozone NAAQS, preparatory to an expected non-attainment de signation for the new NAAQS. This document satisfies 42 U.S.C. §§7410, 7502, 7504 and 7511a (FCAA §§110, 172, 174, and 182) regarding implementation plans, non-attainment plan pr ovisions, planning procedures, and ozone plan submissions and requirements for the 8-hour NAAQS.



### BACKGROUND

Regulatory History The USEPA designated a portion of the southweste rn desert part of Sa n Bernardino County as non-attainment and classified it as Moderate for the 8-hour standard. This area was classified based on an ozone design value calculated from 2001 through 2003 concentrations in the region. The Moderate classification re quires attainment of the 8- hour ozone NAAQS by June 2010, six years after the date of designation.

The MDAQMD was established on July 1, 1993, pursuant to H&SC §41200 et seq (Statutes 1992 ch. 642). The MDAQMD was a successor ag ency to the San Bernardino County Air Pollution Control District (SBCAPCD), which had jurisdiction over the dese rt portions of San Bernardino County commencing in February 19 77 through the formation of the MDAQMD. The Palo Verde Valley portion of eastern Ri verside County was annexed by the MDAQMD from the South Coast Air Quality Management District (SCAQMD) effective July 1, 1994, pursuant to provisions of H&SC 41210(c) and MDAQMD Resolution 94-03.

Initial air quality planning for the region wa s the 1991 Air Quality Attainment Plan (AQAP) which was adopted by the SBCAPCD on August 26, 1991 in response to the State of California ozone planning requirements. Additional oz one plans were adopted by the MDAQMD to address Federal ozone planning requiremen ts, most recently the MDAQMD 2004 Ozone Attainment Plan adopted on April 26, 2004. This document replaces or updates all previously submitted federal ozone plans.6 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 

### Regional Ozone Planning Chronology 1989 - CARB designates SEDAB as non-attainment for ozone SAAQS 1990 - CARB classifies the SEDAB as moderate ozone non-attainment November, 1990 - Adoption of Federal Clean Air Act Amendments August 26, 1991 - Adoption of the 1991 Air Qua lity Attainment Plan (State) by SBCAPCD July 1, 1993 - Formation of Mojave Desert Air Quality Management District July 1, 1994 - Annexation of Palo Verde Valley portion of Riverside County March 24, 1994 - Adoption of Rate-Of- Progress Plan (Federal) by MDAQMD October 26, 1994 - Adoption of Attainment De monstration Plan (F ederal) by MDAQMD 1996 - SEDAB is subdivided into the Mojave De sert Air Basin (MDAB) and the Salton Sea Air Basin (SSAB) January 22, 1996 - Adoption of Triennial Re vision to 1991 AQAP (State) by MDAQMD April 26, 2004 - Adoption of MDAQM D 2004 Ozone Attainment Plan



### Statement of Issues The MDAQMD is downwind of the Los Angeles ba sin, and to a lesser ex tent, is downwind of the San Joaquin Valley. Prevailing winds tran sport ozone and ozone precursors from both regions into and through the MDAB during the summer ozone season. These transport couplings have been officially recognized by CARB. 1 Local MDAQMD emissions contribute to exceedances of both the NAAQS and SAAQS fo r ozone, but photochemical ozone modeling conducted by the SCAQMD and CARB indicates that the MDAB would be inattainment of both standards without the influence of this tr ansported air pollution from upwind regions.



### Federal Legal Requirements The MDAQMD must adopt a plan that provid es for the implementation, maintenance and enforcement of the NAAQS within three years afte r promulgation of the NAAQS. The plan is to include enforceable emission limitations, provide for a monitoring program, provide for a permit program (including a new source review program), contingency measures, and air quality modeling (42 U.S.C. §7410(a); FCAA §110(a)). The MDAQMD most recently met this requirement with the MDAQMD 2004 Ozone Attainment Plan. This document represents an update to that plan. The MDAQMD has adopt ed enforceable emission limitations, has a monitoring system in place throughout the popu lated portions of the Federal Ozone NonAttainment Area (FONA), maintains a permit program (including a New Source Review program with an ambient air quality modeling re quirement), and has performed an attainment demonstration using air quality modeling. This document identifies a contingency measure – see chapter 3.

This document incorporates all reasonably available control me asures (all such measures have already been adopted for the FONA or are being committed to adoption in this plan). This

1 “Ozone Transport: 2001 Review,” April 2001, CARB identifies the South Coast Air Basin as having an overwhelming and significant impact on the Mojave Desert Air Basin (which includes the Mojave Desert) and the San Joaquin Valley as having an overwhelming impact on the MDAB.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 7 document includes a comprehensive, accurate an d current inventory of actual emissions (42 U.S.C. §7502(c)(3), 7511a(a)(1); FCAA §§172(c)(3), 182(a)(1)).

This document discusses reasonable further progress (42 U.S.C. §§7502(c)(2), 7511a(b)(1); FCAA §§172(c)(2), 182(b)(1)) for the appli cable periodic milestone dates (2008, 2011, 2014, 2017 and 2020) (42 U.S.C. §7511a(g); FCAA §182(g)). The FONA is not capable of meeting the reasonable further progress milestones on its ow n; the target levels would require reductions in source categories that are not under the jurisdiction of th e MDAQMD (specifically mobile sources).

This document has been coordinated with the transportation planning pr ocess (42 U.S.C. §7504; FCAA §174). The document includes an emission budget for the FONA, and also includes the on-road mobile source emission budget for the West ern Mojave Desert non-attainment area as an appendix.

This document updates the MDAQMD emission s inventory (42 U.S. C. 7511a(a)(1); FCAA §182(a)(1)).

The MDAQMD has an enhanced non-attainmen t pollutant monitoring program, requires reasonably available control tec hnology (RACT) within the FONA, has a ve hicle inspection and maintenance program, a De Minimis rule, and a gasoline vapor recovery rule. The District participates in the State’s Clean-Fuel Vehicle Program, and performs periodic transportation activity consistency demonstrations (including a review of vehicle miles traveled growth) in conjunction with the Southern California Asso ciation of Governments (SCAG). The MDAQMD controls oxides of nitrogen (NO x ) in addition to Volatile Orga nic Compounds (VOC) within the FONA, and is addressing both pollutants in th is document. The MDAQMD New Source Review (NSR) program defines sources emitting 25 tons per ye ar or more as major and requires offsets at a 1.3 to 1 ratio (42 U.S.C. §§7511a(d), 7511a(d)(2 ); FCAA §§182(d) 182(d)(2)). Employer trip rules (42 U.S.C. §7511a(d)(1); FCAA §182(d)(1)) have been shown to be not cost-effective for the FONA due to low population density.



### Pollutant Description and Health Effects Ozone (or O 3 ) is a colorless gas that is a highly reactive form of oxygen. It has a strong odor when highly concentrated. Ozone can occur na turally but can also be formed from other compounds through photochemistry, a complex system of reactions with hydrocarbons and oxides of nitrogen in the presen ce of sunlight (ultraviolet). The MDAB experiences ozone concentrations in excess of the State a nd Federal ambient ai r quality standards.

Ozone can cause respiratory irri tation and discomfort, making breathing more difficult during exercise. Ozone can reduce the respiratory system’s ability to remove inhaled particles, increase pulse rate, decrease blood pressure and reduce the body’s ability to fight infection. After six hours of exposure a healthy person can have signif icant reduction of lung function. It is an irritant towards the skin, ey es, upper respiratory system, and mucous membranes, although symptoms disappear after exposure. It may also be a carcinogen.8 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 

### Setting The MDAQMD includes the desert portion of Sa n Bernardino County and a portion of eastern Riverside County commonly known as the Palo Verde Valley. A portion of the MDAQMD (herein referred to as the FONA) has been designated non-attainment for the 8-hour ozone NAAQS by USEPA as a portion of the Western Mojave Desert non-attainment area in 40 CFR 81.305. The ozone design value classifies the ar ea as a Moderate non-attainment area with 2010 as the required attainment year (42 U.S.C. 7511(a)(2); FCAA §181(a)(2)). The FONA includes the communities of Phelan, Hesperia, Adelanto, Vi ctorville, Apple Valley, Barstow, Joshua Tree, Yucca Valley and Twentynine Palms (the southwestern portion of the MDAQMD).

The MDAQMD covers more than 20,000 square miles and included 359,551 persons as of the 1990 census (approximately 445,000 in 2002). The re gion is characterize d by hot, dry summers and cool winters, with little precipitation. The National Training Cent er at Fort Irwin, the Marine Corps Air Ground Combat Center, and portions of Edwards Ai r Force Base and the China Lake Naval Air Weapons Station are in the MDAQMD. The MDAQMD also includes the Mojave National Preserve and portions of Death Valley National Park and Joshua Tree National Park

The primary roadways in the MDAQMD are Inte rstate 15, Interstate 40, State Route 58 and United States Route 395. All of these highways ca rry a significant amount of transiting heavy duty truck traffic, and Interstate 15 carries a substantial amount of commute traffic into the greater Los Angeles Basin.

The MDAQMD includes railroad track connectin g the Ports of Los Angeles and Long Beach with the rest of the continental United States, as well as large diameter high pressure natural gas transmission pipelines delivering the majority of the natural gas consumed within the State of California.

The MDAQMD is a growing bedr oom community, but does have si gnificant mining and military activity.



### Ozone Trend The MDAQMD has experienced a substant ial reduction in maximum 8-hour ozone concentrations, as displayed in Figure 1 (Trona is not with in the FONA but is shown for comparison). Note that the three stations closest to the South Coast Air Basin (the source of the majority of transported ozone and ozone precu rsors) have the highe st historical ozone concentrations: Phelan, Hesperia and Victorville. The more distant or isol ated stations (Barstow and Twentynine Palms) have much lower concen trations, and are in fact recently experiencing concentrations in atta inment of the NAAQS.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 9 Figure 1 - Federal 8-Hour Ozone Design Value Trend

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160 0.180

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 20068-Hour Averages (3 Year Average 4th Highest)

Barstow Hesperia
Phelan
Trona Twentynine Palms
Victorville 84 ppb (NAAQS)10 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blankMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 11 

## CHAPTER 2 – Emission Inventories

General Modeled Emission Inventory and Sub-Region Inventory Base Year Future Years12 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blankMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 13 

### General Ozone planning requirements call for the use of seasonal inventories representing emissions during a typical summer day (since ozone con centrations are typically highest under summer weather conditions). This document includes ozone seasonal day inventories, in units of tons per ozone seasonal day (or tons per os day, or t posd), unless otherwise indicated. All emissions presented in this document have been adjusted or calculated in term s of ozone seasonal day emissions.

Federal ozone planning requirements call for emi ssions in terms of Volatile Organic Compounds (VOC), while State ozone planni ng requirements call for emissions in terms of Reactive Organic Gases (ROG). Due to changes in each definiti on, there is no effective difference between the two terms (for example, ethane is now excluded from both definitions). For purposes of this document and attainment planning, the Distri ct considers these te rms interchangeable.



### Modeled Emission Inventory and Sub-Region Inventory The emission inventory for the FONA sub-regi on of the MDAQMD is provided in Appendix A of this document. Complete documentation for San Bernardino Count ry emissions, including emission inventory calculation methodologies, are available fro m the following web address:

http://www.arb.ca.gov/ei/maps/basins/abmdmap.htm

ARB developed a list of the stationary source facilities in the 2002 CEID ARS inventory for San Bernardino County and submitted the list to MDAQMD staff for review to determine whether the facilities are located in the FONA. MDAQMD made this assessment and submitted the FONA facility list to ARB.

Stationary aggregated, areawide, on-road and othe r mobile sources emission sector types are all treated like area sources when assessing em issions in the FONA portion of San Bernardino County. MDAQMD evaluated the San Bernardino County area source inventory to determine the relative fractions that should be assigned to the San Bernardino FONA for these sectors. In most cases, the fractions span major emissi on category groups (as de fined by EIC Summary Code). For a few categories, the fractions are specific to the Emission Inventory Code (EIC).

The California Emission Forecasting System (CEFS) was used to generate future year emission estimates for Stationary Point, Stationary A ggregated, and Areawide category sectors. These future year estimates are based on anticipated so cioeconomic growth rates, and control factors that estimate the impacts of local and state cont rol regulations. For stationary point sources, CEFS projections were run based on the 2002 emission inventory only for the facilities located in the FONA as previously determined. For St ationary Aggregated a nd Areawide sources, the fractions described above were applied to the San Bernardino County inventory developed for CEFSv1.06 and saved as part of the FONA inventory.

Emissions for On-Road sources (for all calendar years) were imported to CEFS directly from EMFAC2007v2.3. Emissions for off-road mobile sour ces (for all calendar years) were imported to CEFS directly from OFFROAD2007. To calculate the FONA portion, the appropriate14 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 fractions were applied to CEFSv1.06 and saved as part of the FONA inventory as described above.



### Federal Ozone Non-Attainment Area Base Year Emission Inventory The initial Federal base year for emission invent ory purposes is 2002. 2002 is used as the base year inventory for all growth scenarios in this document. The base year emission inventory is presented in Appendix A; a summary is presented in Table 1 below. Figure 2 presents the base year source category contribu tions in basic pie chart fo rmat (VOC on the left, NO x on the right). Mobile sources were the primar y emitters in the FONA in 2002.

Table 1 – 2002 Base Year Summary

2002 VOC 2002 NOx Point 5.97 42.18 Area 6.55 0.62 Other mobile 15.98 35.15 On-Road Mobile 18.20 74.24 Totals: 46.69 152.19 (tons per ozone seasonal day)

Figure 2 - 2002 Base Year Pie Charts (FONA)

Point VOC

13%

Area VOC

14%

Other Mobile VOC 34% On-Road Mobile VOC 39% Point NOx 28%

Area NOx

0%

Other Mobile NOx 23% On-Road Mobile NOx 49%



### Future Year Emission Inventories Future year or forecasted emission inventories ar e estimated by multiplying a base year value for each category by a ‘growth code’ for a given future year. The ‘growth code’ is indexed to the base year (2002 for this document), so that its va lue for the base year is 1.00. This allows the growth code to estimate future activity in term s of emissions; if the gr owth code for the year 2007 is 1.50, activity in that cate gory (and resulting emissions) is expected to be 50 percent greater than in 2002. The growth codes used to forecast point sources are available from CARB. Forecasted FONA VOC and NO x inventory summaries for each year of interest are presented in Figures 3 and 4 respectively (the base year is in cluded in each figure for reference). Future year emission inventories are pr esented in Appendix B.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 15 Figure 3 - Forecasted VOC Emission Inventories (FONA)

0.00 10.00 20.00 30.00 40.00 50.00 60.00

2002 2008 2011 2014 2017 2020Tons per Ozone Seasonal Day

Point VOC
Area VOC
Other Mobile VOC
On-Road Mobile VOC
FONA VOC16 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Figure 4 - Forecasted NO x Emission Inventories (FONA)

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00

2002 2008 2011 2014 2017 2020Tons per Ozone Seasonal Day

Point NOx
Area NOx
Other Mobile NOx
On-Road NOx
FONA NOxMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 17 

## CHAPTER 3 – Control and Contingency Measures

Existing Control Measures Proposed Control Measures Rule Adoption Schedule Contingency Measures Required Progress Controlled Emission Inventories Conformity Budgets18 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 19 

### Existing Control Measures The current MDAQMD set of rules and regulations represents a br oad set of control measures for MDAQMD sources. The MDAQMD has in place Reasonably Available Control Technology (RACT) requirements for the majority of sources (including gasoline disp ensing vapor control), as well as an NSR program with a 25 ton per ye ar major source level and a 1.3:1 offset ratio requirement. In 2006, the MDAQMD committed to taking action on several Federal RACT categories. 2 The MDAQMD has recently adopted Federal RACT rules for ship surface coating, 3 glass manufacturing 4 and polyester resin operations. 5 The MDAQMD had committed to adopting three additional RACT rules by th e end of 2007 – the MDAQMD will update the adoption schedule for these actions.



### Proposed Control Measures The MDAQMD is not proposing to adopt any additional control measures for direct ozone precursor reduction purposes. However, the MDAQMD is committed to having all applicable Federal RACT rules, and is currently performi ng analyses on the feasibility of adopting additional rules under the State of California “all feasible measures” mandate. In addition, the MDAQMD will experience additional future emissi on reductions resulting from existing and proposed Federal and State control measures af fecting mobile and area sources (see below).



### State Control Measures
The California Air Resources Bo ard (CARB or ARB) is the St ate agency responsible for ensuring clean air in California. Under State la w, ARB has the responsibility to develop SIP strategies for mobile sources and consumer pr oducts, to coordinate SIP strategies with the Bureau of Automotive Repair (BAR) and Depart ment of Pesticide Regu lation (DPR), and to review local plans for attaining the State a nd Federal ambient air quality standards.

ARB adopted a State Strategy for California’s 20 07 SIP in September, 2007. The State Strategy is comprehensive; it is designed to enable local districts attain federa l air quality standards through a combination of technologically feasible, cost-effective, and far reaching measures for motor vehicles and other statewid e sources. The 2007 State Strategy is also the first to address the federal 8-hour ozone standard – it represents a transition from the less stringent 1-hour standard that was the benchmark for previous SI Ps. The State Strategy also includes measures that will contribute to attainment of the federa l standard for fine part iculates (PM2.5) by the 2014 PM2.5 deadline. The South Coast Air Basin (S CAB) and the San Joaquin Valley are designated nonattainment for the federal PM2.5 standard.

California first enacted passenger car exhaust st andards in 1973. Today the State’s mobile source control program addresses a wide variet y of on- and off-road vehicles and engines,

2 “8-Hour Reasonably Available Control Technology – Stat e Implementation Plan Anal ysis (RACT SIP Analysis),” August, 2006
3 “Rule 1106 – Marine Coating Operations ,” amended October 23, 2006
4 “Rule 1165 – Glass Melting Furnaces ,” amended January 28, 2008
5 “Rule 1162 – Polyester Resin Operations ,” adopted August 27, 200720 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 gasoline and diesel fuel standard s, and engine maintenance require ments. The existing program is projected to reduce emissions from pa ssenger vehicles and heavy-duty trucks by approximately 1/3 between 2006 and 2014. The Stat e Strategy ARB adopted in 2007 will result in a greater than 50 percent reduction in emissions from all mobile sources in the South Coast Air Basin by 2014. Most of the controls in the State Strategy will be impl emented statewide, and directly benefit the entire state. Some will uniquely target the South Coast and San Joaquin Valley Air Basins, directly reducin g emissions in the State’s most polluted areas, and indirectly improving air quality in downwind areas including Ventura, Antelope Valley, the Mojave Desert area, and the Coachella Valley.

The State Strategy addresses thr ee key mobile source is sues: the need to clean up the legacy diesel fleets, the national and international natu re of many diesel flee ts, and limitations on SIP credit for unsecured funding.

The total emission reductions a nd the obligation to propose sp ecific measures for Board consideration would become enforceable upon approval by U.S. EPA of the State Strategy and each district’s attainment plan. While the State Strategy includes estimates of the emission reductions from each of the individual new measures , it is important to note that the State’s commitment is to achieve the aggregate emissi on reductions identified for the adopted State Strategy, from the baseline emissions identified in the SIP. Therefore, if a particular measure does not achieve its expected emission reductions , the State still commits to achieving the total aggregate emission reductions, whet her this is realized through additional re ductions from the new measures, or from alternative control measur es or incentive programs. If actual emission decreases occur that exceed the projections refl ected in the emission i nventories and the State Strategy, the actual emission decreases may be counted toward meeting ARB’s total emission reduction commitments.

ARB’s emission reduction commitments may be achieved through a combination of actions including but not limited to the implementation of control measures; th e expenditure of local, state or federal incentive funds; or through other enforceable measures.

Because ARB scientists determined that reducing emissions of one pollutant, oxides of nitrogen (NO x ), is the most beneficial in reducing levels of both ozone and PM2.5, the state plan focuses on curbing pollution from the sources that pr oduce nearly 90 percen t of the state's NO x . These sources include cars, heavy duty trucks, large o ff-road equipment, ships and locomotives. The baseline emission inventories used to deve lop the 2007 and 2008 federal plans throughout the state incorporate reduc tions from control measures adopt ed through 2006. The State Strategy identifies new measures to be adopted through 2014; ARB has already ac ted on some of these

measures.

The 2007 State Strategy includes the control measures identified be low. Table 2 identifies the timeframes for adoption and implementation of these programs.

Smog Check Improvements The following changes are being developed to improve the effectiveness of the smog check program:MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 21 o A new low pressure evaporative test to examin e passenger vehicles for leaks in fuel tanks and vapor lines that cause smog-forming emissions;

o More stringent inspection standa rds (cutpoints), which are used to determine if a vehicle passes or fails;

o Annual inspections for older and high use vehicles to shorten the time they are emitting excess emissions prior to being repaired;

o The addition of a visible smoke test; and,

o The addition of inspection requirements for diesel passenger cars and trucks and motorcycles, which are currently exempt from Smog Check.

Expanded Passenger Vehicle RetirementIncentives and other programs retire more highemitting passenger vehicles, especially “off-cycle” vehicles – cars and light trucks that are between smog checks inspections.

Reformulated Gasoline Modifications Modifications to Califo rnia’s reformulated gasoline program will eliminate or offset permeation emi ssions resulting from the addition of ethanol to gasoline blends.

Cleaner In-Use Heavy-Duty Trucks Modernize diesel trucks and reduce emissions by requiring replacement or cleanup of the dirtiest trucks on the road. This critical regulation, which is expected to be considered for adoption in 2008, will also include a program for out-of-state trucks doing business in California.

Goods Movement Sources The 2007 State Strategy takes aim at emissions from ships, trucks, harbor craft and other sources associated with the growing g oods movement sector. ARB has already adopted several goods moveme nt emission reduction controls.

o Harborcraft In November 2007 ARB approved a m easure that requires owners of commercial harbor craft to eith er replace old engines with newer, cleaner versions or add control technologies to clean up exhaust.

o Cold Ironing In December 2007, ARB approved a regul ation to provide alternative power supplies at ports so that ships can use clean fu els, including electrici ty, instead of dieselfueled auxiliary engines while at dock.

o Port Trucks In December 2007 ARB approved a measur e requiring retrofit or replacement of older heavy-duty diesel trucks th at service ports or deliver co ntainers from ports to nearby transfer facilities.

o Ship Engines ARB staff is developing a regulation that would require oc ean-going vessels to use cleaner fuels in ship main and auxiliar y engines when they are operating near the California coast.

o Locomotives The State Strategy also calls fo r reducing emissions from line-haul locomotives by replacing and rebuilding existin g engines beginning in 2012. This measure relies in part on U.S. EPA action to ensure th at clean engines are available to meet this schedule.

Construction and Mining Equipment In July 2007, the Board approved a measure which regulates existing construction a nd other industrial equipment. The regulation establishes fleet average emission limits and requires older, dirtie r engines to be replaced by current models or retrofitted with emission control devices. Accelerated clean-up pr ovisions are available to local22 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 districts that provide financial a ssistance to sources that would be subject to the more stringent requirements.

Agricultural Equipment ARB staff is evaluating the opt ions for modernizing and reducing emissions from agricultural equipment, and ARB is expected to consid er a regulation in 2009.

Recreational Boats Existing ARB regulations establis h new emission limits for recreational boats beginning in 2009. The 2007 State Strategy calls for a more stringent, catalyst-based exhaust standard to be phased in by 2013.

Off-Road Recreational Vehicles The State Strategy includes expanded emission standards for off-road recreational vehicles that would re duce exhaust emissions from new vehicles by 50 percent beginning in 2012, using proven automo tive and on-road motorcycle exhaust emission reduction technologies.

Fuel Storage ARB adopted enhanced vapor recovery for above ground storage tanks in June 2007. Additional evaporative emission standards are proposed for portable outboard marine tank engines and refueling gasoline tanks that are us ually mounted on a vehicle and used to refuel other vehicles.

Consumer Products ARB staff will consider new approaches such as alternative, market-based mechanisms, multi-media labeling programs, and public education as it develops ways to meet the State Strategy commitment to further redu ce ROG emissions from consumer products.

Greenhouse Gas Reduction Co-Benefits The California Global Warming Solutions Act of 2006 (AB 32) requires the adoption of a comprehens ive program to reduce greenhouse gas emissions. ARB has already started to adopt regulations in response to this requirement. Although the AB 32 regulations will not directly reduce ozone precursors, many of these regulations are expected to have criteria pollutant “co-benefits.”

Pesticides The Department of Pesticide Regulation’ s 2008 Pesticide Plan includes strategies to reduce ROG emissions from pesticides through regul ation of fumigant pes ticide use, regulatory standards for registration of liquid pesticides, and strategic partnership agreements implementing pest management practices and technologi es that use less pesticide product.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 23 Table 2 – Expected Emission Reducti ons from Proposed New SIP Measures

Mojave Desert Non Attainment Area -- 2020

Direct PM2.5 Passenger Vehicles 0.5 0.5 0 -- Smog Check Improvements (BAR) 0.4 0.3 0 -- Expanded Vehicle Retirement 0.1 0 0 -- Modifications to Reformulated Gasoline Program -- 0.2 -- -- Heavy-Duty Trucks 6.0 0.9 0.6 -- Cleaner In-Use Heavy-Duty Trucks 6.0 0.9 0.6 -- Goods Movement Sources 16.6 2.1 0.6 -- Auxiliary Ship Engine Cold Ironing & Clean Technology -- -- -- -- Cleaner Main Ship Engines and Fuel -- -- -- -- Port Truck Modernization -- -- -- -- Accelerated Intro. of Cleaner Line-Haul Locomotives 16.6 2.1 0.6 -- Clean Up Existing Harbor Craft -- -- -- -- Off-Road Equipment 0.5 0.1 0 -- Cleaner In-Use Off-Road Equipment (over 25hp) 0.5 0.1 0 -- Cleaner In-Use Agricultural Equipment NYQ NYQ NYQ -- Other Off-Road Sources 0 10.6 -- -- New Emission Standards for Recreational Boats 0 0.1 -- -- Expanded Off-Road Rec. Vehicle Emission Standards -- 10.5 -- -- Additional Evaporative Emission Standards -- NYQ -- -- Vapor Recovery for Above Ground Storage Tanks -- NYQ -- -- Areaswide Sources -- 0.5 -- -- Consumer Products Program -- 0.5 -- -- Pesticides: DPR 2008 Pesticide Plan -- NYQ -- -- Emission Reductions from Proposed New Measures 23.6 14.7 1.2 --

NYQ = Not Yet Quantified. BAR = Bureau of Automotive Repair. DPR = Dept. of Pesticide Regulation Locomotives measure relies on U.S. EPA rulemaking and industry agreement to accelerate fleet turnover. Note: Emission reductions reflect the combination impact of regulations and supportive incentive programs. (tons per day) Proposed New SIP Measures NOx ROG SOx



### Local Rule Adoption Schedule
The rule actions identified in Table 3 below are expected to have some (currently unquantified) positive effect on ozone precursor emissions. Th e State all feasible measures actions are analyses that may result in a rule adoption ac tion depending on the outcome of the feasibility analysis – the specified date is for completion of the feasibility analysis.

Table 3 – MDAQMD Rule Adoption Schedule Rule Title Rule Nature Adoption Date Residential Space Heaters Federal RACT 1/2009 Publicly Owned Treatment Works Federal RACT 3/2009 Graphic Arts Amendment Federal RACT 9/22/2008 Solvent Cleaning and Degreasing Stat e All Feasible Measures 10/27/2008 Gas Turbines State All Feasible Measures 10/27/2008 Boilers, Generators and Process Heater s State All Feasible Measures 10/27/2008 Internal Combustion Engines Stat e All Feasible Measures 10/27/2008 Cement Kilns State All Feasible Measures 10/27/2008 Commercial Charbroilers State All Feasible Measures 10/27/2008 Residential Gas Furnaces State All Feasible Measures 10/27/200824 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Rule Title Rule Nature Adoption Date Residential Water Heaters State All Feasible Measures 10/27/2008 Soil Decontamination State All Feasible Measures 10/27/2008 Landfill Gas State All Feasible Measures 10/27/2008 Adhesives and Sealants State All Feasible Measures 10/27/2008 Woodworking Operations State Al l Feasible Measures 10/27/2008 Lawnmower Buyback State All Feasible Measures 10/27/2008 Metal Parts and Products Coating St ate All Feasible Measures 10/27/2008 Spray Booths State All Feasible Measures 10/27/2008 Wood Flat Stock Coating State All Feasible Measures 10/27/2008 Composting Operations State Al l Feasible Measures 10/27/2008 Residential Wood Burning State All Feasible Measures 10/27/2008



### Contingency Measures The MDAQMD reaffirms the use of the State E nhanced Inspection and Maintenance Program as a contingency measure. The MDAQMD would im plement the State of California’s version of Enhanced I&M should a contingency measure be tri ggered by failure to attain the Federal 8-hour standard.



### Required Progress Federal law specifies that each ozone non-atta inment area must demonstrate ongoing emission reductions relative to the base year (2002). Federal law requires a three percent (3%) per year reduction in VOC emissions, and does not allow cr edit to be taken for certain federal motor vehicle control programs (FMV CP). Where both VOC and NO x emissions have been shown to contribute to high ozone levels , the Clean Air Act allows NO x emission reductions to be used to augment VOC emission reductions in order to de monstrate reasonable further progress. In nonattainment areas that are impacted by transport from other regions, the Federal Clear Air Act also allows emissions and emission reduction from t hose regions to be taken into account when assessing reasonable further progress. Ai r quality modeling, described in Chapter 4, demonstrates that emissions from the SCAB c ontribute to violations of the NAAQS in both the Antelope Valley and Mojave Desert portions of the federal non- attainment area (the WMDONA)

Table 4 demonstrates that the rate of progress projected for the WMDONA meets Federal Clean Air Act requirements. The required rate of progress is met in part by substituting NO x reductions for VOC reductions at the rate of 1.6 tons of NO x per ton of VOC shortfall. The WMDONA consists of the Antelope Valley in Los Ange les County and the Mojave and Victor Valley portions of San Bernardino Count y. The reasonable further pr ogress assessment takes into account projected emissions for upwind areas within 100 kilometers of the WMDONA (specifically Orange County and the SCAB portions of Los Angeles and San Bernardino Counties) as allowed by USEPA guidance.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 25 Table 4 - Reasonable Furth er Progress for the WMDONA

2002 2008 2011 2014 2017 2020 Baseline ROG 882.5 651.1 601.9 570.3 551.9 543.5 CA MVCP/RVP Adjustment 0.0 54.4 71.0 84.5 91.5 96.0 RACT Corrections 000000 Adjusted 2002 Baseline ROG in milestone year 882.5 828.1 811.4 798.0 791.0 786.5 RFP commitment for ROG reductions from new measures 00000 Required % change since previous milestone year (ROG or NOx) compared to 2002 15% 9% 9% 9% 9%

Required % change since 2002 (ROG or NOx) 1 15% 24% 33% 42% 51% Target ROG levels 703.9 616.7 534.6 458.8 385.4 Apparent shortfall in ROG -52.78 -14.73 35.68 93.17 158.17 Apparent shortfall in ROG, % -6.4% -1.8% 4.5% 11.8% 20.1% ROG shortfall previously provided by NOx substitution, % 0.0% 0.0% 0.0% 4.5% 11.8% Actual ROG shortfall, % -6.4% -1.8% 4.5% 7.3% 8.3%

Baseline NOx 1123.7 905.0 789.0 696.9 622.9 574.2 CA MVCP Adjustment 0.0 64.8 80.8 93.2 98.7 102.8 Adjusted 2002 Baseline NOx in milestone year 1123.7 1058.8 1042.9 1030.4 1025.0 1020.8 RFP commitment for NOx reductions from new measures 000000 Change in NOx since 2002 153.8 253.8 333.6 402.1 446.6 Change in NOx since 2002, % 14.5% 24.3% 32.4% 39.2% 43.8% NOx reductions since 2002 already used for RFP substitution and contingency through last milestone year, % 0.0% 3.0% 3.0% 7.5% 14.8% NOx reductions since 2002 available for RFP substitution and contingency in this milestone year, % 14.5% 21.3% 29.4% 31.8% 29.0%

Change in NOx since 2002 used for ROG substitution in this milestone year, % 0.0% 0.0% 4.5% 7.3% 8.3% Change in NOx since 2002 available for contingency in this milestone year, % 3.0% 3.0% 3.0% 3.0% 3.0% Change in NOx since 2002 surplus after meeting substitution and contingency needs in this milestone year, % 11.5% 21.3% 24.9% 24.4% 20.6%

RFP shortfall, if an y 0.0% 0.0% 0.0% 0.0% 0.0% RFP Met? YES YES YES YES YES Contingency Met? YES YES YES YES YES

1 15% ROG only reduction required from 2002-2008 Western Mojave Desert & Antelope Valley (with transport from Orange, San Bernardino-SCAB and LA-SCAB), summer planning, tons per day



### Controlled Emission Inventories As the MDAQMD is not proposing any additional local control measures with quantified emission reductions, the controlled emission inve ntory is identical to the forecasted emission inventory.



### Conformity Budgets The forecasted emission inventories presented in this document are the emission budgets for general conformity purposes, as no additional control measures with quantified emission reductions are proposed. A project subject to the general conformity test must be demonstrated to conform with the applicable portion of the forecasted emission inventory. For a project that falls between forecasted years, a linearly interpolated inventory may be calculated. For a project that falls after 2020, use 2020.

The forecasted on-road mobile source inve ntory represents the emission budget for transportation conformity purposes, as no tran sportation control meas ures are proposed. A26 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 project subject to the transporta tion conformity test must be demonstrated to conform with the forecasted on-road mobile source inventory. The FONA on-road mobile source inventory is presented below, in addition to the appendices . The portion presented in Table 5 is for information only - the MDAQMD is officially ad opting the transportation budget for the entire Western Mojave Desert oz one non-attainment area as presented in Appendix C.

Table 5 - Transportation Conformity Budget (FONA) (tons per ozone seasonal day) 2002 2008 2011 2014 2017 2020 On-Road Mobile VOC 18.20 14.67 12.42 10.18 8.70 7.75 On-Road NOx 74.24 66.88 56.86 43.37 33.12 26.57MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 27 

## CHAPTER 4 – Attainment Demonstration

Modeling Approach Overview Modeling Domain Model Inputs Modeling Results ARB Weight of Evidence Assessment28 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 29 

### ATTAINMENT DEMONSTRATION This chapter paraphrases and reiterates in formation from the most recent SCAQMD/CARB ozone model runs, the runs performed for th e 2007 SCAQMD AQMP. For further information, please refer to Appendix V of that document. 6

The Federal Clean Air Act (FCAA) required the use of photochemical air quality modeling to evaluate whether a proposed cont rol strategy will result in attain ment of the applicable ozone standard. Recognizing the uncertain ty inherent in large-scale air quality models, recent federal guidance has also required an evaluation of suppl ementary data, known as a weight of evidence analysis. A weight of evidence analysis can also be used to support an attainment demonstration if photochemical modeling indicates that the co ntrol strategy will result in future ozone concentration that will approach but not quite reach the standard.



### Modeling Approach Overview The Western Mojave Desert ozone non-attainme nt area, which includes the MDAQMD, is a small portion of the complex grea ter Southern Califor nia airshed. Ozone and ozone precursors are known to flow (or be transported), under the influence of winds, throughout Southern California. The most technically accurate me thod of evaluating ozone concentrations, ozone emissions, and future ozone behavior is through a large modeling project th at includes all of the affected areas in Southern Calif ornia (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 CARB, with SCAQMD and CARB staff and resources doing the pr imary work. This regional modeling effort has allowed the most accurate understanding and pr ediction of future ozone concentrations for Southern California.

The modeled attainment demonstration in this pl an was prepared using photochemical dispersion and meteorological tools developed in re sponse to USEPA modeling guidelines, and recommendations from air quality modeling expe rts. The Urban Airshed Model (UAM) is the regional modeling system preferred by USEPA a nd CARB for analyzing ozone non-attainment areas. The UAM predicts future 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 Federal ozone standards we re exceeded. The UAM also evaluates ozone precursor emissions, local and regional meteorol ogy, and regional topography to calculate ozone concentrations. These calculations are perf ormed on an hourly basi s throughout the modeled episode, thus allowing the UAM to stimulate changing conditions (i.e . night, day and wind).

Meteorological fields were generated using th e MM5 prognostic meteorological model, and the required modeling emissions inventories were developed by CARB and SCAQMD staff. The ozone air quality modeling utilized the Compre hensive Air Quality Model with Extensions (CAMx) model, with initial and boundary c onditions based on estimates of clean-air concentrations. Analysis of the model outpu ts included the estimation of 1-hour and 8-hour ozone concentrations for each ozone monitoring s ite within the domain, as well as statistical

6 “Final 2007 Appendix V - Modeling and Attainment Demonstrations,” SCAQMD, June 200730 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 measures comparing observed and stimulated ozone concentrations. These analyses were used to evaluate model performance by sub-region within the domain.



### Modeling Domain The modeling domain is based on the domain de fined for the 1997 Southern California Ozone Study and includes the South Coast Air Basin and the surrounding coastal, desert and mountain areas, including the MDAQMD. This model domain includes the upwind sources within SCAQMD, which are responsible for the overwhelming ozone transport into the MDAQMD. The northern boundary of the model extends into Santa Barbara and Kern counties, while the southern boundary extends in Mexico. The eastern boundary of the modeling domain extends into the desert portions of San Bernardino and Riverside counties, while the western boundary extends into the Pacific Ocean. The domain horizontal grid is 116 by 80 cells, with a cell resolution of five kilometers.



### Model Inputs SCAQMD performed the UAM attainment demons tration using data maintained by CARB and MDAQMD. The emissions inventory used for the UAM is consistent with the emissions inventory presented in the appendices to this document.



### Modeling Results Future years are simulated twice using the UAM: first, using the uncontrolled emissions inventory; and second, using a reduced emissions inventory controlled by the proposed ozone control strategy. Comparing the uncontrolled and controlled ambient ozone concentrations identifies the effectiveness of the proposed oz one control strategy. At tainment year ambient ozone concentrations using the reduced emissi ons inventory controlled by the proposed ozone control strategy should achieve the ozone standard.

As required by federal guidance, a relative re duction factor (RRF) approach was used in projecting future design values. The RRF refl ects the ratio between the future year model prediction (in this case the end of 2020) and the reference year model prediction (in this case 2002). A reference or base year design value is then multiplied by the RRF to project a future year design value. The modeling satisfies the minimum five episode requirement for use in developing a site-specific RRF for most site s, as recommended by the USEPA guidance for modeling 8-hour ozone design values.

Table 6 presents the photochemical ozone modeling results for the FONA, including sites within the MDAQMD.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 31 Table 6 - 2020 Federal Ozone Attainment Demonstration

Baseline (2001-2003) 2012 2017 2020 Lancaster 100.7 86.5 79.7 74.0 Phelan 104.7 92.6 86.7 80.5 Victorville 98.3 88.0 77.0 74.4 Hesperia 106.3 95.7 88.7 76.5 Barstow 87.6 79.7 73.2 79.5 Twentynine Palms 86.7 77.3 65.8 82.2 Modeled (all values ozone in ppb)

The modeling results show that the MDAQMD will not attain the 8-hour ozone NAAQS (84 ppb) by the 2012 attainment deadline for Seriou s ozone non-attainment areas, or the 2017 deadline for Severe-15 non-attainment areas, but that the MDAQMD will attain by the 2020 deadline for Severe-17 non-attainment areas.



### ARB Weight of Evidence Assessment Federal modeling guidelines also require non-at tainment areas to determine whether other evidence, such as evaluations of air quality a nd emission trends, support the modeled attainment demonstration. USEPA’s ozone modeling guidan ce also indicates that when photochemical modeling projects attainment y ear concentrations of between 0.082 and 0.087 ppm, the State may conduct further analyses of the model out comes and consider other evidence such as emissions and air quality trends data. If the we ight of this evidence s upports a finding that the proposed control program will result in attain ment by the statutory deadline, the State may consider this evidence in determining whethe r the proposed control program will result in attainment.

CARB has performed a detailed weight of eviden ce assessment for the attainment demonstration of the MDAQMD portion of the Western Mojave Desert federa l ozone nonattainment area. This analysis supports the determination that th e MDAQMD portion will attain the Federal 8-hour ozone standard by the 2020 deadline for Severe-17 areas on the basis of reduced transported air pollution from upwind areas. Because the photoc hemical modeling projected a high value of 88.7 ppm in 2017, the weight of evidence analysis cannot be used to support a projection of attainment by 2017. The ARB Weight of Eviden ce assessment is presented in Appendix F.32 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 33 

## Appendices A - Base Year Emission Inventory B - Future Year Emission Inventories C - Transportation Conformity Budgets D - Annual Ambient Monitoring Data Summary E - ARB Weight of Evidence Assessment34 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 A-1 

### APPENDIX A - BASE YEAR EMISSION INVENTORY

All emissions are presented in tons per oz one seasonal day (except where noted) for the 2002 base year

NOx VOC Stationary ELECTRIC UTILITIES 4.65 0.14 COGENERATION 0.10 0.00 MANUFACTURING AND INDUSTRIAL 2.49 0.15 SERVICE AND COMMERCIAL 2.56 0.21 OTHER (FUEL COMBUSTION) 0.22 0.02 SEWAGE TREATMENT 0.00 0.00 LANDFILLS 0.00 0.11 INCINERATORS 0.06 0.00 OTHER (WASTE DISPOSAL) 0.00 0.02 LAUNDERING 0.00 0.00 DEGREASING 0.00 1.00 COATINGS AND RELATED PROCESS SOLVENTS 0.00 0.57 PRINTING 0.00 0.01 ADHESIVES AND SEALANTS 0.00 0.03 OTHER (CLEANING AND SURFACE COATINGS) 0.00 0.00 PETROLEUM MARKETING 0.02 2.34 CHEMICAL 0.00 0.21 FOOD AND AGRICULTURE 0.00 0.00 MINERAL PROCESSES 29.95 0.95 METAL PROCESSES 0.50 0.00 WOOD AND PAPER 0.00 0.00 GLASS AND RELATED PRODUCTS 1.58 0.00 OTHER (INDUSTRIAL PROCESSES) 0.06 0.21 Stationary Subtotal 42.18 5.97 Area-Wide CONSUMER PRODUCTS 0.00 2.78 ARCHITECTURAL COATINGS AND RELATED PROCESS S O 0.00 1.53 PESTICIDES/FERTILIZERS 0.00 0.02 ASPHALT PAVING / ROOFING 0.00 0.31 RESIDENTIAL FUEL COMBUSTION 0.45 0.15 FARMING OPERATIONS 0.00 0.72 CONSTRUCTION AND DEMOLITION 0.00 0.00 PAVED ROAD DUST 0.00 0.00 UNPAVED ROAD DUST 0.00 0.00 FUGITIVE WINDBLOWN DUST 0.00 0.00 FIRES 0.00 0.01 MANAGED BURNING AND DISPOSAL 0.17 0.42 COOKING 0.00 0.61 Area-Wide Subtotal 0.62 6.55 On-Road Mobile LIGHT DUTY PASSENGER (LDA) 6.28 6.11 LIGHT DUTY TRUCKS - 1 (LDT1) 4.12 3.31 LIGHT DUTY TRUCKS - 2 (LDT2) 4.20 2.35 MEDIUM DUTY TRUCKS (MDV) 1.60 0.80 LIGHT HEAVY DUTY GAS TRUCKS - 1 (LHDV1) 0.34 0.25 LIGHT HEAVY DUTY GAS TRUCKS - 2 (LHDV2) 0.21 0.16 MEDIUM HEAVY DUTY GAS TRUCKS (MHDV) 0.20 0.23 HEAVY HEAVY DUTY GAS TRUCKS (HHDV) 0.53 0.14 LIGHT HEAVY DUTY DIESEL TRUCKS - 1 (LHDV1) 0.02 0.00 LIGHT HEAVY DUTY DIESEL TRUCKS - 2 (LHDV2) 0.46 0.01 MEDIUM HEAVY DUTY DIESEL TRUCKS (MHDV) 1.58 0.02 HEAVY HEAVY DUTY DIESEL TRUCKS (HHDV) 53.57 3.75 MOTORCYCLES (MCY) 0.19 0.93 HEAVY DUTY DIESEL URBAN BUSES (UB) 0.07 0.00 HEAVY DUTY GAS URBAN BUSES (UB) 0.05 0.02 SCHOOL BUSES (SB) 0.41 0.03 OTHER BUSES (OB) 0.12 0.02 MOTOR HOMES (MH) 0.29 0.07 On-Road Subtotal 74.24 18.20 Other Mobile AIRCRAFT 0.16 0.13 TRAINS 29.20 2.19 RECREATIONAL BOATS 0.07 0.46 OFF-ROAD RECREATIONAL VEHICLES 0.23 10.61 OFF-ROAD EQUIPMENT 5.02 1.90 FARM EQUIPMENT 0.48 0.10 FUEL STORAGE AND HANDLING 0.00 0.58 Other Mobile Subtotal 35.15 15.98

FONA Totals: 152.19 46.69A-2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 FONA Point Sources for 2002 (all em issions in tons per year)
ROG NOx Aerochem Inc Aerospace El Mirage 0.9 176.7 Lockheed Martin Aerospace Helendale 0.3 0.2 SCLA Aerospace Victorville 0.0 0.5 Aerospace Totals: 1.2 177.4 Agcon Inc Batch Plant Helendale 0.0 0.0 Blue Diamond Materials Batch Plant Victorville 0.0 0.0 Calmat Vulcan Batch Plant Oro Grande 2.0 6.3 Cornerstone C&M Batch Plant Victorville 0.0 0.0 Dan Copp Crushing Batch Plant Barstow 0.0 1.2 Diversified Materials Batch Plant Hesperia 0.0 0.0 Diversified Materials Batch Plant Lucerne Valley 0.0 0.5 Granite Construction Batch Plant Twentynine Palms 0.0 0.0 Hanson Aggregate Batch Plant Newberry Springs 25.4 168.4 Hi-Grade Materials Batch Plant Hesperia 0.0 0.0 Hi-Grade Materials Batch Plant Lucerne Valley 0.9 13.7 Kinne Limestone Batch Plant Lucerne Valley 0.2 2.6 Robertson's Readymix Batch Plant Adelanto 0.1 0.8 Service Rock Products Batch Plant Barstow 0.0 0.0 Sierra Aggregate Batch Plant Lucerne Valley 0.6 6.9 Batch Plant Totals: 29.2 200.4 Cemex Black Mountain Quarry Cement Manufacturing Apple Valley 63.3 5383.0 Cemex River Plant Cement Manufacturing Victorville 0.0 0.0 Mitsubishi Cement Cement Manufacturing Lucerne Valley 17.1 2244.8 TXI Riverside Cement Cement Manufacturing Oro Grande 77.4 4186.0 Cement Manufacturing Totals: 157.8 11813.8 California Cogeneration Electric Generation Victorville 0.0 5.5 Daggett Leasing Electric Generation Daggett 6.3 13.0 Harper Lake Electric Generation Harper Lake 17.5 23.5 Kramer Junction Electric Generation Boron 15.3 62.0 Reliant Energy Electric Generation Daggett 15.8 909.5 SCE Victorville Electric Generation Victorville 0.0 0.4 US West Financing Electric Generation Oro Grande 0.7 35.8 Electric Generation Totals: 55.6 1049.7 Cabo Yachts Fiberglass Adelanto 18.9 0.0 Hawaiian Fiberglass Fiberglass Adelanto 5.6 0.0 Kormil Industries Fiberglass Hesperia 1.8 0.0 May Manufacturing Fiberglass Victorville 7.1 0.0 Molded Fiber Glass Fiberglass Adelanto 16.1 0.0 Pacific Tank Fiberglass Adelanto 4.0 0.0 Rainbow Fiberglass Fiberglass Adelanto 18.4 0.0 Fiberglass Totals: 71.9 0.0

AFG Industries Glass Manufacturing Victorville 0.1 578.5 Desert Valley Hospital Institution Victorville 0.3 0.7 Hi Desert Medical Institution Joshua Tree 0.0 0.7 St. Mary Hospital Institution Apple Valley 0.3 4.7 Veterans Home of Barstow Institution Barstow 0.1 1.1 Victor Valley Community Hospital Institution Victorville 0.1 3.2 Victor Valley Memorial Institution Victorville 0.1 0.0 Institution Totals: 0.9 10.4MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 A-3 AFFTC Edwards Military Edwards 0.0 0.1 US Army Dagget Airfield Military Daggett 1.1 1.3 USMC Logistics Base Nebo Military Barstow 5.4 11.5 USMC Logistics Base Yermo Military Barstow 20.2 35.3 USMCAGCC Military Twentynine Palms 3.5 17.3 Military Totals: 30.2 65.5 Brubaker-Mann Mining Barstow 0.0 0.0 Calico Rock Mining Barstow 0.0 0.0 OMYA Mining Lucerne Valley 0.1 1.1 Rheox Mining Newberry Springs 0.2 9.1 Specialty Minerals Mining Lucerne Valley 0.1 1.5 Victorville Industrial Minerals Mining Oro Grande 0.0 0.0 Mining Totals: 0.4 11.7 Advance Disposal Misc Coating/Manuf Hesperia 0.3 0.0 Alrayco Misc Coating/Manuf Adelanto 0.0 4.7 Daily Press Misc Coating/Manuf Victorville 1.5 0.0 Ennis Paint Misc Coating/Manuf Adelanto 0.0 0.0 Fast Tops Misc Coating/Manuf Hesperia 15.1 0.0 Induction Technology Misc Coating/Manuf Adelanto 0.4 0.0 Jack B. Kelly Misc Coating/Manuf Adelanto 0.7 0.0 JPM Product Misc Coating/Manuf Hesperia 0.5 0.1 Labelhouse Misc Coating/Manuf Adelanto 2.1 0.0 Lead Masters Misc Coating/Manuf Hesperia 0.0 0.0 McWelco Products Misc Coating/Manuf Hesperia 2.9 0.0 Mobile Pipe Wrap Misc Coating/Manuf Adelanto 14.6 0.2 National Arnold Magnetics Misc Coating/Manuf Adelanto 13.5 0.8 Northwest Pipe & Casing Misc Coating/Manuf Adelanto 11.5 0.0 Sherwin-Williams Misc Coating/Manuf Victorville 32.5 0.0 Simtec Misc Coating/Manuf Hesperia 0.1 0.0 Spede Tool Mfg Misc Coating/Manuf Adelanto 0.9 0.8 Spede Tool Mfg Misc Coating/Manuf Adelanto 4.6 0.0 Technique Design Misc Coating/Manuf Morongo Valley 0.2 0.0 TPS Technologies Misc Coating/Manuf Adelanto 0.2 15.7 World of Leisure Misc Coating/Manuf Adelanto 6.9 0.1 Misc Coating/Manuf Totals: 108.5 22.4 PG&E Hinkley Natural Gas Transmission Hinkley 70.1 578.7 SCG Adelanto Natural Gas Transmission Adelanto 0.5 32.8 SCG Kelso Natural Gas Transmission Kelso 0.5 80.4 SCG Newberry Springs Natural Gas Transmission Newberry Springs 3.0 171.5 SCG Victorville Natural Gas Transmission Victorville 0.1 0.0 Natural Gas Transmission Totals: 74.2 863.4 Accent Auto Body Paint & Body Hesperia 0.6 0.0 Best Auto Body Paint & Body Hesperia 0.1 0.0 Daves Auto Body Paint & Body Lenwood 0.1 0.0 Doman Auto Body Paint & Body Hesperia 0.2 0.0 Mc Geez Auto Body Paint & Body Twentynine Palms 1.4 0.0 Monty's Chevrolet Paint & Body Victorville 1.0 0.0 Pacific Paint Paint & Body Hesperia 0.2 0.0 Rancho Motors Paint & Body Victorville 0.3 0.0 Sonshine Auto Body Paint & Body Victorville 1.0 0.0 Sunland Ford Paint & Body Victorville 0.2 0.0 Sunset Paint and Body Paint & Body Hesperia 1.7 0.0 Yucca Auto Body Paint & Body Yucca Valley 1.0 0.0 Yucca Valley Ford Paint & Body Yucca Valley 0.3 0.0 Paint & Body Totals: 8.1 0.0A-4 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Beck Oil Petroleum Pipeline & Terminal Victorville 0.6 0.0 CalNev Bulk Plant Petroleum Pipeline & Terminal Daggett 35.1 0.0 Petroleum Pipeline & Terminal Totals: 35.7 0.0 Barstow Railyard Railroad Switching Barstow 6.4 0.9 City of Barstow Wastewater/Landfill/Water Barstow 0.2 37.8 Lenwood Hinkley Wastewater/Landfill/Water Hinkley 0.1 0.8 Victor Valley Wastewater Treatment Wastewater/Landfill/Water Victorville 0.0 1.5 Wastewater/Landfill/Water Totals: 0.3 40.1 C&M Wood Industries Wood Coating Hesperia 6.9 1.2 Commercial Wood Products Wood Coating Adelanto 7.9 0.0 Hacker Wallsystems Wood Coating Yucca Valley 0.1 0.0 Inland Panel Coatings Wood Coating Adelanto 20.9 0.0 Mueller Turner Wood Coating Morongo Valley 1.3 0.0 Terrell Industries Wood Coating Hesperia 13.3 0.0 Walnut Valley Finishing Wood Coating Adelanto 26.7 1.9 Wood Coating Totals: 77.1 3.1

FONA Totals (tpy): 657.6 14837.3 Totals (tpaad): 1.80 40.65MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 B-1 

### APPENDIX B - FUTURE YEAR EMISSION INVENTORIES (all emissions in tons per ozone se asonal day unless othe rwise indicated) VOC:

SUBCATEGORY 2002 2008 2011 2014 2017 2020 Stationar y ELECTRIC UTILITIES 0.14 0.20 0.21 0.21 0.23 0.27 COGENERATION 0.00 0.00 0.00 0.00 0.00 0.00 MANUFACTURING AND INDUSTRIAL 0.15 0.16 0.17 0.18 0.19 0.19 SERVICE AND COMMERCIAL 0.21 0.21 0.21 0.21 0.21 0.21 OTHER (FUEL COMBUSTION) 0.02 0.02 0.02 0.02 0.02 0.02 SEWAGE TREATMENT 0.00 0.00 0.00 0.00 0.00 0.00 LANDFILLS 0.11 0.13 0.13 0.14 0.15 0.15 INCINERATORS 0.00 0.00 0.00 0.00 0.01 0.01 OTHER (WASTE DISPOSAL) 0.02 0.02 0.02 0.02 0.03 0.03 LAUNDERING 0.00 0.00 0.00 0.00 0.00 0.00 DEGREASING 1.00 1.00 1.04 1.08 1.11 1.15 COATINGS AND RELATED PROCESS SOLVENTS 0.57 0.62 0.65 0.69 0.72 0.75 PRINTING 0.01 0.01 0.01 0.01 0.01 0.01 ADHESIVES AND SEALANTS 0.03 0.03 0.04 0.04 0.04 0.05 OTHER (CLEANING AND SURFACE COATINGS) 0.00 0.00 0.00 0.00 0.00 0.00 PETROLEUM MARKETING 2.34 2.59 2.72 2.85 2.99 3.13 CHEMICAL 0.21 0.25 0.27 0.29 0.30 0.32 FOOD AND AGRICULTURE 0.00 0.00 0.00 0.00 0.00 0.00 MINERAL PROCESSES 0.95 1.05 1.11 1.17 1.23 1.29 METAL PROCESSES 0.00 0.00 0.00 0.00 0.00 0.00 WOOD AND PAPER 0.00 0.00 0.00 0.00 0.00 0.00 GLASS AND RELATED PRODUCTS 0.00 0.00 0.00 0.00 0.00 0.00 OTHER (INDUSTRIAL PROCESSES) 0.21 0.22 0.25 0.25 0.28 0.31 Stationary Subtotal 5.97 6.53 6.85 7.18 7.52 7.89 Area-Wide CONSUMER PRODUCTS 2.78 2.80 3.01 3.22 3.43 3.64 ARCHITECTURAL COATINGS AND RELATED PROCES 1.53 1.37 1.41 1.46 1.51 1.57 PESTICIDES/FERTILIZERS 0.02 0.02 0.02 0.02 0.02 0.02 ASPHALT PAVING / ROOFING 0.31 0.32 0.32 0.32 0.33 0.33 RESIDENTIAL FUEL COMBUSTION 0.15 0.16 0.17 0.17 0.18 0.18 FARMING OPERATIONS 0.72 0.72 0.72 0.72 0.72 0.72 CONSTRUCTION AND DEMOLITION 0.00 0.00 0.00 0.00 0.00 0.00 PAVED ROAD DUST 0.00 0.00 0.00 0.00 0.00 0.00 UNPAVED ROAD DUST 0.00 0.00 0.00 0.00 0.00 0.00 FUGITIVE WINDBLOWN DUST 0.00 0.00 0.00 0.00 0.00 0.00 FIRES 0.01 0.01 0.01 0.01 0.01 0.01 MANAGED BURNING AND DISPOSAL 0.42 0.37 0.35 0.33 0.31 0.28 COOKING 0.61 0.68 0.72 0.75 0.79 0.82 Area-Wide Subtotal 6.55 6.46 6.74 7.01 7.30 7.58 On-Road Mobile LIGHT DUTY PASSENGER (LDA) 6.11 3.75 2.84 2.07 1.63 1.34 LIGHT DUTY TRUCKS - 1 (LDT1) 3.31 2.06 1.68 1.31 1.00 0.79 LIGHT DUTY TRUCKS - 2 (LDT2) 2.35 1.77 1.54 1.29 1.14 1.03 MEDIUM DUTY TRUCKS (MDV) 0.80 0.77 0.69 0.64 0.59 0.56 LIGHT HEAVY DUTY GAS TRUCKS - 1 (LHDV1) 0.25 0.18 0.15 0.13 0.14 0.15 LIGHT HEAVY DUTY GAS TRUCKS - 2 (LHDV2) 0.16 0.10 0.09 0.07 0.07 0.06 MEDIUM HEAVY DUTY GAS TRUCKS (MHDV) 0.23 0.11 0.08 0.06 0.04 0.03 HEAVY HEAVY DUTY GAS TRUCKS (HHDV) 0.14 0.09 0.08 0.07 0.05 0.05 LIGHT HEAVY DUTY DIESEL TRUCKS - 1 (LHDV1) 0.00 0.01 0.01 0.01 0.01 0.01 LIGHT HEAVY DUTY DIESEL TRUCKS - 2 (LHDV2) 0.01 0.01 0.01 0.01 0.01 0.01 MEDIUM HEAVY DUTY DIESEL TRUCKS (MHDV) 0.02 0.02 0.02 0.02 0.02 0.02 HEAVY HEAVY DUTY DIESEL TRUCKS (HHDV) 3.75 3.80 3.28 2.52 1.92 1.54 MOTORCYCLES (MCY) 0.93 1.88 1.84 1.88 1.98 2.08 HEAVY DUTY DIESEL URBAN BUSES (UB) 0.00 0.00 0.00 0.00 0.00 0.00 HEAVY DUTY GAS URBAN BUSES (UB) 0.02 0.02 0.02 0.02 0.02 0.02 SCHOOL BUSES (SB) 0.03 0.03 0.03 0.03 0.03 0.03 OTHER BUSES (OB) 0.02 0.02 0.02 0.02 0.02 0.01 MOTOR HOMES (MH) 0.07 0.05 0.04 0.03 0.02 0.01 On-Road Subtotal 18.20 14.67 12.42 10.18 8.70 7.75 Other Mobile AIRCRAFT 0.13 0.16 0.17 0.19 0.20 0.21 TRAINS 2.19 2.24 2.29 2.35 2.43 2.52 RECREATIONAL BOATS 0.46 0.39 0.35 0.33 0.31 0.30 OFF-ROAD RECREATIONAL VEHICLES 10.61 15.28 16.82 18.61 20.65 22.94 OFF-ROAD EQUIPMENT 1.90 1.67 1.48 1.32 1.21 1.15 FARM EQUIPMENT 0.10 0.08 0.06 0.05 0.04 0.03 FUEL STORAGE AND HANDLING 0.58 0.40 0.33 0.28 0.24 0.22 Other Mobile Subtotal 15.98 20.23 21.50 23.12 25.07 27.37

Grand Total 46.69 47.89 47.51 47.50 48.60 50.58B-2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 NOx:

SUBCATEGORY 2002 2008 2011 2014 2017 2020 Stationar y ELECTRIC UTILITIES 4.65 6.75 7.00 7.00 7.79 8.98 COGENERATION 0.10 0.10 0.10 0.10 0.10 0.09 MANUFACTURING AND INDUSTRIAL 2.49 2.76 2.88 3.03 3.16 3.28 SERVICE AND COMMERCIAL 2.56 2.59 2.58 2.57 2.54 2.50 OTHER (FUEL COMBUSTION) 0.22 0.24 0.24 0.24 0.24 0.24 SEWAGE TREATMENT 0.00 0.00 0.00 0.00 0.00 0.00 LANDFILLS 0.00 0.00 0.00 0.00 0.00 0.00 INCINERATORS 0.06 0.06 0.07 0.07 0.07 0.08 OTHER (WASTE DISPOSAL) 0.00 0.00 0.00 0.00 0.00 0.00 LAUNDERING 0.00 0.00 0.00 0.00 0.00 0.00 DEGREASING 0.00 0.00 0.00 0.00 0.00 0.00 COATINGS AND RELATED PROCESS SOLVENTS 0.00 0.00 0.00 0.00 0.00 0.00 PRINTING 0.00 0.00 0.00 0.00 0.00 0.00 ADHESIVES AND SEALANTS 0.00 0.00 0.00 0.00 0.00 0.00 OTHER (CLEANING AND SURFACE COATINGS) 0.00 0.00 0.00 0.00 0.00 0.00 PETROLEUM MARKETING 0.02 0.02 0.02 0.02 0.02 0.02 CHEMICAL 0.00 0.00 0.00 0.00 0.00 0.00 FOOD AND AGRICULTURE 0.00 0.00 0.00 0.00 0.00 0.00 MINERAL PROCESSES 29.95 32.74 34.35 36.11 37.78 39.36 METAL PROCESSES 0.50 0.49 0.52 0.55 0.58 0.61 WOOD AND PAPER 0.00 0.00 0.00 0.00 0.00 0.00 GLASS AND RELATED PRODUCTS 1.58 1.72 1.90 2.08 2.19 2.33 OTHER (INDUSTRIAL PROCESSES) 0.06 0.06 0.06 0.06 0.07 0.08 Stationary Subtotal 42.18 47.53 49.72 51.84 54.55 57.56
Area-Wide CONSUMER PRODUCTS 0.00 0.00 0.00 0.00 0.00 0.00 ARCHITECTURAL COATINGS AND RELATED PROCESS SOLVE N 0.00 0.00 0.00 0.00 0.00 0.00 PESTICIDES/FERTILIZERS 0.00 0.00 0.00 0.00 0.00 0.00 ASPHALT PAVING / ROOFING 0.00 0.00 0.00 0.00 0.00 0.00 RESIDENTIAL FUEL COMBUSTION 0.45 0.48 0.49 0.50 0.52 0.53 FARMING OPERATIONS 0.00 0.00 0.00 0.00 0.00 0.00 CONSTRUCTION AND DEMOLITION 0.00 0.00 0.00 0.00 0.00 0.00 PAVED ROAD DUST 0.00 0.00 0.00 0.00 0.00 0.00 UNPAVED ROAD DUST 0.00 0.00 0.00 0.00 0.00 0.00 FUGITIVE WINDBLOWN DUST 0.00 0.00 0.00 0.00 0.00 0.00 FIRES 0.00 0.00 0.00 0.00 0.00 0.00 MANAGED BURNING AND DISPOSAL 0.17 0.15 0.14 0.14 0.13 0.12 COOKING 0.00 0.00 0.00 0.00 0.00 0.00
Area-Wide Subtotal 0.62 0.63 0.64 0.64 0.65 0.65

On-Road Mobile LIGHT DUTY PASSENGER (LDA) 6.28 3.81 2.99 2.23 1.76 1.42 LIGHT DUTY TRUCKS - 1 (LDT1) 4.12 2.38 2.00 1.59 1.24 0.97 LIGHT DUTY TRUCKS - 2 (LDT2) 4.20 3.12 2.65 2.15 1.79 1.50 MEDIUM DUTY TRUCKS (MDV) 1.60 1.57 1.35 1.15 0.99 0.84 LIGHT HEAVY DUTY GAS TRUCKS - 1 (LHDV1) 0.34 0.36 0.37 0.36 0.36 0.38 LIGHT HEAVY DUTY GAS TRUCKS - 2 (LHDV2) 0.21 0.13 0.13 0.12 0.12 0.12 MEDIUM HEAVY DUTY GAS TRUCKS (MHDV) 0.20 0.14 0.11 0.09 0.07 0.06 HEAVY HEAVY DUTY GAS TRUCKS (HHDV) 0.53 0.35 0.35 0.34 0.35 0.36 LIGHT HEAVY DUTY DIESEL TRUCKS - 1 (LHDV1) 0.02 0.59 0.46 0.36 0.30 0.26 LIGHT HEAVY DUTY DIESEL TRUCKS - 2 (LHDV2) 0.46 0.57 0.49 0.40 0.32 0.27 MEDIUM HEAVY DUTY DIESEL TRUCKS (MHDV) 1.58 1.92 1.68 1.29 0.99 0.78 HEAVY HEAVY DUTY DIESEL TRUCKS (HHDV) 53.57 50.49 42.82 31.83 23.39 18.22 MOTORCYCLES (MCY) 0.19 0.50 0.51 0.54 0.58 0.62 HEAVY DUTY DIESEL URBAN BUSES (UB) 0.07 0.06 0.05 0.05 0.05 0.05 HEAVY DUTY GAS URBAN BUSES (UB) 0.05 0.04 0.04 0.04 0.04 0.04 SCHOOL BUSES (SB) 0.41 0.44 0.47 0.49 0.49 0.48 OTHER BUSES (OB) 0.12 0.14 0.13 0.11 0.09 0.07 MOTOR HOMES (MH) 0.29 0.28 0.26 0.22 0.18 0.14
On-Road Subtotal 74.24 66.88 56.86 43.37 33.12 26.57
Other Mobile AIRCRAFT 0.16 0.20 0.21 0.23 0.25 0.26 TRAINS 29.20 22.25 17.07 18.16 19.42 20.85 RECREATIONAL BOATS 0.07 0.10 0.10 0.10 0.11 0.11 OFF-ROAD RECREATIONAL VEHICLES 0.23 0.33 0.37 0.41 0.46 0.51 OFF-ROAD EQUIPMENT 5.02 4.27 3.73 3.18 2.61 2.17 FARM EQUIPMENT 0.48 0.37 0.32 0.26 0.20 0.15 FUEL STORAGE AND HANDLING 0.00 0.00 0.00 0.00 0.00 0.00
Other Mobile Subtotal 35.15 27.52 21.81 22.35 23.04 24.05

Grand Total 152.19 142.56 129.03 118.20 111.35 108.83MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 C-1 

### APPENDIX C –TRANSPORTAT ION CONFORMITY BUDGETS



### Antelope Valley - Western Mojave Desert Nonattainment Area Transportation Conformity Budgets Summer Planning Emissions in Tons per Day*

2008 ROG NOx

On-Road Emissions from EMFAC2007 22.7 82.0

Adjustments to Baseline* 0.0 -4.4

Net Inventory 22.63 77.56

Conformity Budget** 23 78

* Reductions from adopted rules not reflected in EMFAC ** Budget is obtained by rounding up to the nearest ton.


### Antelope Valley - Western Mojave Desert Nonattainment Area Transportation Conformity Budgets Summer Planning Emissions in Tons per Day*

2011 ROG NOx

On-Road Emissions from EMFAC2007 19.8 70.5

Adjustments to Baseline* -0.1 -4.4

Net Inventory 19.7 66.1

Conformity Budget** 20 67

* Reductions from adopted rules not reflected in EMFAC ** Budget is obtained by rounding up from two significant figures to the nearest ton.C-2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 

### Antelope Valley - Western Mojave Desert Nonattainment Area Transportation Conformity Budgets Summer Planning Emissions in Tons per Day*

2014 ROG NOx

On-Road Emissions from EMFAC2007 16.6 54.9

Adjustments to Baseline* -0.1 -4.1

State Strategy Reductions -3.4 -15.3

Net Inventory 13.0 35.5

Conformity Budget** 14 36

* Reductions from adopted rules not reflected in EMFAC ** Budget is obtained by rounding up from two significant figures to the nearest ton.


### Antelope Valley - Western Mojave Desert Nonattainment Area Transportation Conformity Budgets Summer Planning Emissions in Tons per Day*

2017 ROG NOx

On-Road Emissions from EMFAC2007 14.5 43.1

Adjustments to Baseline* -0.1 -3.9

State Strategy Reductions -2.5 -14.1

Net Inventory 11.9 25.1

Conformity Budget** 12 26

* Reductions from adopted rules not reflected in EMFAC ** Budget is obtained by rounding up from two significant figures to the nearest ton.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 C-3 

### Antelope Valley - Western Mojave Desert Nonattainment Area Transportation Conformity Budgets Summer Planning Emissions in Tons per Day*

2020 ROG NOx

On-Road Emissions from EMFAC2007 13.2 35.4

Adjustments to Baseline* -0.1 -3.7

State Strategy Reductions -1.7 -7.4

Net Inventory 11.4 24.2

Conformity Budget** 12 25

* Reductions from adopted rules not reflected in EMFAC ** Budget is obtained by rounding up from two significant figures to the nearest ton.C-4 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 D-1 

### APPENDIX D - ANNUAL AMBIEN T MONITORING DATA SUMMARY

Maximum One Hour Ozone (ppm) Barstow Hesperia Phelan Trona Twentynine Palms Victorville 1988 0.15 0.27 0.19 0.12 0.15 0.18 1989 0.14 0.21 0.22 0.10 0.13 0.17 1990 0.13 0.27 0.24 0.11 0.14 0.18 1991 0.13 0.19 0.24 0.12 0.14 0.19 1992 0.13 0.23 0.19 0.10 0.12 0.19 1993 0.13 0.17 0.20 0.10 0.13 0.16 1994 0.13 0.18 0.19 0.10 0.12 0.16 1995 0.12 0.17 0.24 0.09 0.11 0.15 1996 0.13 0.17 0.18 0.10 0.12 0.16 1997 0.12 0.18 0.19 0.10 0.12 0.15 1998 0.11 0.16 0.20 0.11 0.12 0.16 1999 0.12 0.13 0.14 0.10 0.11 0.12 2000 0.11 0.16 0.14 0.09 0.11 0.14 2001 0.10 0.12 0.15 0.09 0.12 0.11 2002 0.11 0.15 0.15 0.11 0.10 0.13 2003 0.11 0.16 0.14 0.10 0.10 0.15 2004 0.10 0.14 0.12 0.11 0.10 0.11 2005 0.10 0.14 0.15 0.09 0.11 0.13 2006 0.11 0.15 0.14 0.09 0.14

Maximum 3-Yr Av 4th H 1986 0.225 0.168 1987 0.161 0.163 1988 0.167 0.165 1989 0.161 0.153 1990 0.198 0.151 1991 0.173 0.151 1992 0.165 0.147 1993 0.147 0.139 1994 0.155 0.138 1995 0.170 0.137 1996 0.146 0.131 1997 0.133 0.124 1998 0.144 0.127 1999 0.122 0.118 2000 0.132 0.110 2001 0.117 0.102 2002 0.123 0.106 2003 0.13 0.106 2004 0.119 0.107 2005 0.123 0.105 2006 0.124 0.103 8-Hour Trend (FONA)E-2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-1 

### APPENDIX E – ARB WEIGHT OF EVIDENCE ASSESSMENT (prepared by CARB staff)E-2 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 This page intentionally left blank.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-3 

### Western Mojave Desert Weight of Evidence Assessment

Introduction

For ozone planning purposes, the U.S. EPA has combined portions of Los Angeles and San Bernardino counties and designated them as the Western Mojave 8-Hour Ozone Nonattainment Area. The Nonattainment Area includes the nor theast portion of Los Angeles County and the southwest portion of San Bernardino County, both of which are in the Mojave Desert Ai r Basin (refer to Figure 1). These two areas are managed by two separate jurisdictions. The Antelope Va lley Air Quality Management District has jurisdiction over the Los Angeles County por tion of the Nonattainment Area, while the Mojave Desert Air Quality M anagement District has jurisdiction over the San Bernardino County portion of the Nonattainm ent Area. This Weight of Evidence (WOE) evaluation covers the San Bernardino County portion of the Nonattainment Area which is referred to as the Western Mojave Desert Planning Area in this document.

Figure 1: Western Mojave Desert Planning Area and Surrounding RegionE-4 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 The Western Mojave Desert Planning Area (W estern Mojave Desert or Planning Area) is currently classified as a Moderate nona ttainment area for the federal 8-hour ozone standard and has a nominal attainment deadline of June 15, 2010. However, air quality analyses, as well as photochemical modeling completed by the South Coast Air Quality Management District (South Coast District), indicate it is unlikely the Desert will attain by 2010, as required for Moderate areas. Ozone air quality in the Western Mojave Desert is impacted by transport fr om both the South Coast Air Basin (South Coast) and the San Joaquin Valley Air Basin (San Joaquin Valley ). As a result, attainment projections for Western Mojave Desert must consider not only local emissions, but also the impact of transported emission s and pollutants.

Although the proposed South Coast, San Joaquin Valley, and statewide emissions reduction strategies will lower ozone concentrati ons in the Western Mojave Desert over the next several years, the expected level of emissions reductions will fall short of those needed to attain by 2010. However, the mo deling results do show that the Planning Area could attain by the 2021 deadline for a Severe-17 nonattainment area. Therefore, the Mojave Desert Air Qua lity Management District has requested a reclassification to Severe-17, with an attainment date of J une 15, 2021. The followi ng sections describe the air quality and emissions analyses needed to justify re classifying the Western Mojave Desert Planning Area as Severe-17 and to support the overall conclusion that the Planning Area will attain the federal standard by 2021.

U.S. EPA Attainment Demonstration Requirements

The attainment demonstration portion of a SIP consists of the analyses used to determine whether a proposed control strat egy provides the emissions reductions needed to meet the federal st andard by the attainment year. This attainment demonstration includes photochemical mode ling which predicts that projected emissions controls will result in an 8- hour ozone design value of 0.082 parts per million (ppm) by the end of 2020 (note: because the design value is based on a three-year average, an area mu st have a design value that meets the standard at the end of the year prior to the attainment y ear; for example, an ar ea with a June 15, 2021 attainment date must have a design value that meets the standard at the end of 2020). Because of the uncertainties inherent in photochemical modeling, the U.S. EPA allows states to supplement the modeling resu lts with a “Weight of Evidence” (WOE) demonstration when the model predicts ozon e levels of 0.082 ppm to 0.087 ppm.

The WOE assessment may include considerati on of measured air quality, emissions, and meteorological data, eval uation of other air quality indicators, and additional air quality modeling. Because all analysis methods have strengths and weaknesses, examining an air quality problem in a variet y of ways helps offset the limitations and uncertainties that are inherent in each particular method. The scope of the WOE analysis is different fo r each nonattainment area. The level of detail appropriate for a particular area depends upon the complexity of the air quality problem, how far into the fu ture the attainment deadline is, and the amount of data andMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-5 modeling available. This document summa rizes the analyses that comprise the WOE assessment for the Western Mojave Dese rt Planning Area as of March 2008.

Physical Context

The Western Mojave Desert Planning Area (refer to Figure 1) is located in southwestern San Bernardino County, within the Mojave Desert Air Basin and falls under the jurisdiction of the Mojave Desert Air Quality Management District. Although the Western Mojave Desert Pl anning Area is the focus of this WOE Evaluation, on the federal level, the West ern Mojave Desert Planning Area is included with the Antelope Valley Plann ing Area as a single federa l 8-hour ozone nonattainment

area.

The Western Mojave Desert area extends about 90 miles north to south and 120 miles east to west. The Planning Area is classifi ed as high desert with elevations ranging from 2,000 to 5,000 feet and annual precipitation averaging 4 to 6 inches. Average daily maximum temperatures are highest dur ing July, ranging from 100 to 105 degrees Fahrenheit. In contrast, winte r daily maximum temperatures average in the low 60s.

The Western Mojave Desert is a recreationa l area and given its proximity to the South Coast, provides a transportation link to the ur banized area. Major ci ties in the Planning Area include Victorville, Hesperia, Apple Va lley, and Twentynine Palm s. Overall, the Planning Area comprises about 9200 square mile s and has a total population of more than 350,000 (2006 estimate). The major highways traveling through the Western Mojave Desert are Interstate 15 , Interstate 40 , U.S. Highway 395 , and California State Highway 58. These roadways carry signific ant commuter and truck traffic in and out of the South Coast region.

Transport Impacts

As mentioned earlier, ozone concentrations in the Western Mojave Desert are impacted by transport from both the S outh Coast and San Joaquin Valle y. Therefore, transport must be considered in evaluat ing the prospects for attainment. Several mountain passes provide transport routes into the West ern Mojave Desert from the South Coast. Soledad Canyon on the eastern edge of the San Gabriel Mountains and Cajon Pass between the San Gabriel and San Bernardino mountains are the two major transport corridors from the South Coast to the Western Mojave Desert. A third transport corridor runs through the Tehachapi Pass in the Tehac hapi Mountains and provides an outlet for emissions and pollutants from the southern S an Joaquin Valley to the Western Mojave Desert.

Previous ARB transport assessments conc luded that during 1- hour State ozone exceedances, the transport contri bution from the South Coast to ozone in the Western Mojave Desert could be overwhelming. The transport assessments also found thereE-6 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 could be a shared impact between the Sout h Coast and Western Mojave Desert, meaning ozone exceedances could be caused by a combination of transport and local emissi ons (ARB 1990; ARB 1996) 7, 8 . In addition to the South Coast impact, the ARB transport assessments found an overwhelming transport impact from the San Joaquin Valley to t he Western Mojave Desert.

Although the impact of transport on ozone air qua lity in the Western Mojave Desert can be overwhelming, the frequency of the impacts has not been determined. However, more recent analyses indicate that ozone ex ceedances in the Western Mojave Desert continue to be impacted by transported pollu tants. Areas impac ted by transport generally show ozone concentrations peaking in the late afternoon or evening hours. The 24-hour ozone profile for Hesperia, which is located in the southwestern portion of the Planning Area, just north of the Sout h Coast (refer to Fi gure 2), shows this characteristic later peak, indicating that tr ansport is an important contributor to high ozone concentrations in this area.

The impact of transport is also seen in the southeastern portion of the Planning Area. Figure 3 shows diurnal plots of hourly av erage ozone concentrations at Banning in the South Coast, Palm Springs in the C oachella Valley Planning Area, and Joshua Tree in the Western Mojave Dese rt Planning Area (refe r to Figure 1 for relative locations). These three sites reflect a general west -to-east transport of emissions and pollutants. As shown in Figure 3, the daily peak ozone concentration occurs at a progressively later hour with distance downwind of the major South Coast emissions source areas. This progressively later peak hour with distance suggests that transport is the primary cause of high ozone at the downwind locations. Therefore, as emi ssions are reduced in the upwind source areas, ozone air quality in the downwind transpor t impacted areas should also improve. Recent photochemical modeling completed for the Western Mojave Desert also evaluated the impact of transported emission s on air quality in the Western Mojave Desert. In general, the results showed t hat without transport, emissions within the Western Mojave Desert would likely not be sufficient to generate a violation of the federal 8-hour ozone standard in future years.

7 Air Resources Board, 1990: Assessment and Mitigat ion of the Impacts of Transported Pollutants on Ozone Concentrations within California . ARB Staff Report prepared by the Technical Support Division and the Office of Air Quality Planning and Liaison, June 1990.

8 Air Resources Board, 1996: Second Triennial Review of the Assessment of the Impacts of Transported Pollutants on Ozone Concentrations in California (Revised) . ARB Staff Report prepared by the Technical Support Division, November 1996.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-7 Figure 2: Hourly Average Ozone on the Top Ten Days During 2006 at Hesperia

Hourly Ozone on the Top Ten Days During 2006 at Hesperia

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Hour (PST)Concentration (ppm)

Figure 3: Hourly Average Ozone on the Top Ten Days During 2006 at Banning, Palm Springs, and Joshua Tree

Hourly Average Ozone on Top Ten Days During 2006 at Downwind Sites

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Hour (PST)Concentration (ppm)

Joshua Tree Palm Springs Banning Airport

Ozone Air Quality Trends

The following discussion is based on ozone air quality data collected at sites in the Western Mojave Desert from 1995 to the pr esent. During this time period, five monitoring sites have complete data: Bars tow, Hesperia-Olive Street, Joshua TreeNational Monument, Phelan-Beekley Road & Phelan Road, and Victorville-14306 ParkE-8 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Avenue. In addition, a sixth site operated at Twentynine Palms, but data are available only through 2005. Of the six long-term si tes, Hesperia, Joshua Tree, and Phelan are the high sites with respect to ozone.

Ozone indicator values for the Western Mojave Desert are shown in Figure 4. As seen in the figure, all indicators have decreased since 1995, indicating overall improvements in the various measures of ozone air quality. As in many other areas of the State, the largest drop is seen in the number of exceedance days – an overall decrease of 35 percent from 1995 to 2006 (from 74 days to 47 days). The value for 2007 is slightly less than that for 2006, with 45 e xceedance days during the year.

Figure 4: Western Mojave Desert Planning Area Ozone Trends 1995 to 2006

Western Mojave Desert Planning Area Ozone Statistics

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
YearOzone (ppm)

0 20 40 60 80 100 120 140 160 180 200Number of Days

Maximum Concentration Design Value Mean Top 30 Exceedance Days

While not quite as high, the improvement in the other indicators has also been fairly substantial. Overall, the maximum c oncentration and design value decreased 20 and 25 percent, respectively. The decrease in the mean Top 30 was a bit less, at 15 percent between 1995 and 2006. Bas ed on complete data, the 2007 maximum concentration was lower (0.109 ppm in 2007 compared with 0.124 ppm in 2006), while the mean Top 30 concentration was compar able (0.096 ppm in 2007 compared with 0.095 ppm in 2006). The 2007 design value s howed no change from the previous year (0.103 ppm in 2007 and 2006). Although the 2007 design value for Western Mojave Desert is still more than 20 percent above t he federal standard, it compares with a design value nearly 60 percent above the standard in 1995 (0 .133 ppm). Thus, the area has already achieved two-thirds of t he progress needed to attain the standard.

It is interesting to note that the Western Mojave Desert trend lines for all four indicators show little or no progress between 2001 and 2006. A similar trend is seen in ozone statistics for the South Coast (refer to Figure 5). As discussed earlier in this document,MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-9 emissions and pollutants trans ported from the S outh Coast can have an overwhelming impact on ozone in the Western Mojave Desert. Therefore, it is not unexpected that the shapes of the trend lines fo r the Western Mojave Dese rt and the South Coast are similar. However, while the South Coas t shows a slight decrease from 2001 to 2006, the Western Mojave Desert trend is essent ially flat, because of the trend at Joshua Tree.

Figure 5: Federal 8-Hour Ozone Design Values for Western Mojave Desert Planning Area and South Coast Air Basin 1995 to 2006

Federal 8-Hour Design Values for Mojave Desert & South Coast

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
YearOzone (ppm)

South Coast Air Basin Western Mojave Desert Planning Area

Looking at the design values for individual si tes in the Western Mojave Desert gives some insight as to how ozone air quality is changing within the Planning Area and how Joshua Tree compares with other sites. Figure 6 shows the trend lines for Hesperia and Joshua Tree (note: although not shown, t he trend line for Phelan is similar to that for Hesperia). The trend line for Hesperia shows an overall reduction in design value, although the decrease since 2001 is slight. In contrast, Joshua Tr ee shows an overall increase in design value, with the increase being es pecially apparent since 2001, although the trend has flattened out ov er the last several years.

While the Joshua Tree and Phelan trends diff er, both the trend and level of the design value for Joshua Tree are similar to those for Palm Springs in the Coachella Valley Planning Area. As mentioned previously, both of these si tes are located downwind of the South Coast Air Basin. Previous ARB transport assessments show that Palm Springs is overwhelmed by trans port from the South Coast. It is likely that Joshua Tree is also impacted by transport, although ARB has not completed a formal assessment.E-10 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Given the likelihood of a trans port impact, a portion of th e increase in the trend at Joshua Tree may be attributable to changi ng emissions in the South Coast.

Figure 6: Federal 8-Hour Ozone Design Values for Hesperia and Joshua Tree 1995 to 2006

Federal 8-Hour Design Values for Mojave Desert Sites

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
YearOzone (ppm)

Hesperia Joshua Tree

Over time, emissions reductions in the South Coast have reduced the reactivity of the hydrocarbon mix. Because the mix is le ss reactive now, it takes longer for the photochemical reactions that form ozone to o ccur. With the reduction in reactivity, ozone concentrations in areas closer to the major South Coast emissions source areas have improved more rapidly than those in downw ind areas. Because of the slower rate of improvement, it will take these downwi nd areas longer to reach attainment. Photochemical modeling analyses indicate that Palm Springs will reach attainment for the federal 8-hour ozone standard by 2018. Be cause the design value concentrations and trends for Palm Springs and the Western Mo jave Desert are so similar, it is reasonable to assume that the Desert will reach attainment in approximately the same timeframe as Palm Springs. Therefore, re classifying the Western Mojave Desert as Severe-17 with a June 15, 2021 a ttainment date is appropriate.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-11 Spatial Ozone Trends

Another way to look at t he improvement in air quality is to map the change in the number of exceedance days. The maps in Figure 7 are based on monitoring data and show the reduction in the number of days exceeding the federal 8-hour standard over the last decade (1995 to 2005). This approach provides an estimate of the change in the spatial extent of t he ozone problem. Ten years ago (1995 map, based on 1993 to 1995 means), about a quarter of the Western Mojave Desert experienced 51 to 100 exceedance days per year, while most of

Figure 7: Western Mojave Desert Planning Area Change in Federal 8-Hour Exceedance Days 1995 to 2005



### Western Mojave Desert Planning Area Federal 8-Hour Exceedance DaysE-12 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 the remaining areas experienced 21 to 50 da ys per year. Today (2005 map, based on 2003 to 2005 means), about half of the Desert falls into the 21 to 50 days per year category, with the other half having 11 to 20 days and 6 to 10 days per year. The exceedance day maps clearly illustrate the influence of the South Coast on Western Mojave Desert. The highest number of ex ceedance days is found in the southwestern portion of the Planning Area, adjacent to th e South Coast Air Basin. However, as shown on the maps, air quality in these areas has improved over time, and it should continue to improve with impl ementation of the South C oast and Statewide emissions control strategies.

Additional Air Quality Analyses

ARB staff conducted additional air quality analyses and also reviewed photochemical modeling for the Western Mojave Desert to assess whether t he rate of progress historically, as well as the more modes t progress in recent years, supports a 2021 attainment date.

Mean of the Top 30 Analysis

The mean of the Top 30 repr esents the mean or average of the 30 highest daily maximum 8-hour ozone concentrations measur ed at a site during each year. Changes in this indicator over time reflect the change in the av erage ozone concentration on the 30 worst days. Because this indicator is based on a relatively large number of observations, it is more robust than other i ndicators, such as maximum concentration. Although the mean of the Top 30 is not directly related to the federal standard, it does provide a stable indicator that is not hi ghly influenced by year-to-year changes in meteorology.

Figure 8 shows the trend of the mean of t he Top 30 8-hour ozone concentrations for the three high sites in Western Mojave Dese rt. Since 1995, t he mean of the Top 30 declined 10 and 20 percent, respectively, at He speria and Phelan. In contrast, the mean Top 30 values increased about 5 percent at Joshua Tree. As a way of gaining further insight into how the mean of t he Top 30 has changed over time, ARB staff evaluated the rate of change, relative to the st art year (1995) at t he same three sites. For this evaluation, three-year averages of the annual mean Top 30 values were normalized to the start year by calcul ating the ratio of the averaged Top 30 concentration for each year to the 1995 averaged Top 30 concentration. The normalized rate of progress values are plotted in Figure 9.

Hesperia and Phelan both show overall prog ress during the 12-year period. Although progress has slowed over the last 5 to 6 year s, the recent trend is downward, and the 2006 values for both sites are slightly lower than the 2001 values. In contrast, the Joshua Tree site shows an upward trend since 2001. As mentioned earlier (refer to Ozone Air Quality Trends section), the la ck of progress at Joshua Tree may be attributable to transport from the South Coast. Because em issions reductions in theMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-13 South Coast have reduced the reactivity of the hydrocarbon mix, it now takes longer for ozone to form. As a result, ozone air qualit y has improved faster in the upwind areas located closer to South Coast emissions source areas than it has in the downwind transport impacted areas. The impact of tr ansport is discussed further in the next section.

Figure 8: Mean of the Top 30 Daily Ma ximum 8-Hour Ozone Concentrations for Phelan, Hesperia, and Joshua Tree 1995 to 2006

Western Mojave Desert Planning Area Sites Mean of the Top 30 8-Hour Ozone Concentrations

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

YearConcentration (ppm)

Phelan Hesperia Joshua Tree

Figure 9: Mean of Top 30 8-Hour Oz one Concentrations at Western Mojave Desert Sites Normalized to 1995 Start Year

Western Mojave Desert Planning Area Sites Normalized 3-Year Average Rate of Change of Mean Top 30 8-Hour Ozone Concentrations

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

YearConcentration (ppm)

Joshua Tree Phelan Hesperia Modeling Evaluations and Regression AnalysesE-14 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 As part of the photochemical modeling analys es, South Coast District staff evaluated the impacts of transport on attainment in th e Western Mojave Dese rt. Using a gridded domain, South Coast District staff modeled se veral emissions reduction scenarios using the two 2005 modeling episodes. The scenario s included (1) removing emissions from the local planning area (Western Mojave De sert and Antelope Valley planning areas); (2) removing emissions from Ventura and Santa Barbara counties, and (3) removing emissions from the South Coast. The resu lts demonstrated that em issions within the Western Mojave Desert Planning Area were not sufficient to generate federal 8-hour ozone exceedances and that the impact of South Coast emi ssions was overwhelming. Therefore, emissions reducti ons in the upwind area are cr itical to the attainment demonstration. Given the results of the mo deling evaluations, the current trends at Joshua Tree are not expected to delay the 2021 attainment date for Western Mojave Desert.

As additional analyses, ARB staff completed regression analyses of design values for the South Coast versus Western Mojave Desert, as well as the San Joaquin Valley

versus Western Mojave Desert. Although t here are a number of uncertainties associated with these analyses, the result s suggest that the design value for the Western Mojave Desert, including the Jo shua Tree area, will reach the level of attainment before either the South Coast or San Joaquin Valley, both of which have a 2024 attainment date. This lends further support to the 2021 attainment date for Western Mojave Desert.

Emissions Trends

In 2006, ROG emissions in the Western Mo jave Desert were dominated by off-road recreational vehicles, light duty passenger vehicles, heavy duty diesel trucks, and petroleum marketing. The main contributor s of NOx emissions were heavy duty diesel trucks, mineral processing, trains, and off-road equipment. Statewide and local emissions control measures have signific antly reduced the amounts of both ROG and NOx emitted by various sources throughout Cali fornia. However, these reductions have not resulted in the same rate of decline in emissions in all areas. Furthermore, emissions in the Western Mojave Desert continue to be overshadowed by emissions from the South Coast and San Joaquin Valley. Figure 10 shows the estimated trend in the Western Mojave Desert ozone precursor emissions from 1995 to 2006. The totals reflect estimates for the summer season in tons per day and do not include emissions from natural biogenic sources.

ROG emissions show a small decline over the ent ire period. In contrast, there has been a fairly consistent increase in NOx emissi ons. The overall decrease in ROG emissions is about 15 percent from 1995 to 2006, compared with a 5 per cent overall increase in NOx emissions during the same time period. Despite these chang es, the levels of emissions in the Western Mojave Desert ar e less than levels in the upwind areas. For comparison, 2005 ROG and NOx emissions in the South Coast were about 10 andMDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-15 5 times the level, respectively, of those in the Western Mojave Desert, while ROG and NOx emissions in the San Joaquin Valley were both about 5 times the level of those in the Desert. As emissions in these upwin d areas are reduced, ozone air quality in the downwind Western Mojave Dese rt should also improve.

Figure 10: Western Mojave Desert Estimated ROG and NOx Emissions 1995 to 2006

Western Mojave Desert Planning Area ROG and NOx Emissions Summer SIP Inventory without Biogenics - Ver 1.06

0 50 100 150 200 250

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

YearEmissions (tons/day)

NOx ROG

Photochemical Modeling Results

The U.S. EPA (2005) provided criteria for ca lculating future year 8-hour ozone design values using air quality simulation results. Among these criteria were recommendations for air quality model performance, obser ved and simulated ozone concentration thresholds, and the number of simulated days used to calculate the relative response factor (RRF) used to scale reference year des ign values for future years. To meet these criteria, the South Coast District staff evaluated the re sults from the simulation of six high ozone episode periods occurring during the years 2004 and 2005.

Of the six episodes, the simulation result s for the July 15 through 19, 2005 and the August 3 through 9, 2005 episode periods showed high concentrations and acceptable air quality model performance fo r ozone monitoring sites in t he Western Mojave Desert and Antelope Valley planning areas. Ther efore, subsequent analysis focused on these two periods. To evaluate future year ozone design values, the Sout h Coast District staff simulated these episodes using emissions inventories developed for the years 2002 (the reference year for design values), 2005 (to evaluate ozone model performance), 2012, 2017 (for an attainment year of 2018), and 2020 (for an attainm ent year of 2021). Emissions totals were based on projections from the South Coast District’s 2007 Air Quality Management Plan.E-16 MDAQMD Federal 8-hour Ozone Attainment Plan June 9, 2008 Based on the results, Phelan and Hesperia have the highest design values in 2017, but do not meet the federal 8-hour standard by then. Theref ore, a 2018 attainment date, similar to that for the Coachella Valley Pl anning Area, is not appropriate. However, modeling predicted a design va lue at Phelan of 0.080 pp m by the end of 2020, which does show attainment and is consistent wit h a June 15, 2021 attainment deadline. The Joshua Tree site shows a 2020 design value of 0.060 ppm, while Twentynine Palms, the highest site in 2020, shows a design value of 0.082 ppm. These sites, as well as all others in the Western Mojave Desert and Antelope Valley planning areas, therefore show attainment by the end of 2020, as r equired for a Severe-17 nonattainment area and are consistent with a June 15, 2021 attainment deadline.

Summary

The Weight of Evidence package comprises a set of analyses that provide support for the attainment demonstration. Currently, th e Western Mojave Desert is classified as Moderate with respect to the federal 8-hour ozone standard, wit h attainment required by 2010. Because of the transport impact of emissions and polluta nts from the South Coast and San Joaquin Valley and the expected timing of emissions reductions in these upwind areas, the Mojave Desert Air Q uality Management District has requested reclassification of the Western Mojave Desert Planning Area as Severe-17, with an attainment date of June 15, 2021. Bas ed on the air quality and emissions analyses completed for the WOE assessment, attainment in the Western Mojave Desert can be projected by 2021, based on the following factors:

• Since 1995, there has been a 35 percent decrease in exceedance days, 20 and 25 percent decreases in maximum concentration and design value, and a 15 percent decreas e in the mean Top 30 value. Although progress has slowed over the last five to six years, the ozone indicators, taken together, continue to show some improvement, albeit at a slower rate. Because of the continued improvement, the design value for Western Mojave Desert is now about 20 percent above the level of the standard, compared wit h a design value nearly 60 percent above the standard in 1995.

• Transport and air quality analyses support a link between the South Coast and Western Mojave Desert, as well as the San Joaquin Valley and Western Mojave Desert, with res pect to ozone air quality. ROG and NOx emissions in the upwind areas are 5 to 10 times the level of those in the Western Mojave De sert. Furthermore, the transport impact from the upwind areas is overwhelming on some days. Modeling analyses show that attainment in the Western Mojave Desert will be dependent on emissions reduc tions in the upwind areas.MDAQMD Federal 8-hour Oz one Attainment Plan June 9, 2008 E-17 • The South Coast, San Joaquin Valley, and statewide emissions control strategies are expected to result in massive emissions reductions over the next 15 years, with both upwin d areas expecting attainment by 2024. These emissions reductions wil l help facilitate attainment in downwind areas such as the Wester n Mojave Desert. Because ozone levels in the Western Mojave Desert are not as high as levels in the South Coast or the San Joaquin Va lley, the emissions reductions needed for attainment in the Western Mo jave Desert are not as high. Therefore, attainment is expected earlier than 2024.

• Although there is a great deal of unc ertainty in the regression analyses completed for the Western Mojave Desert, they do suggest that the Western Mojave Desert will reach a ttainment before either the South Coast or San Joaquin Valley air basins.

• Photochemical modeling shows t he Western Mojave Desert will not attain by 2010, or even by 2018. Ho wever, results show the area will attain by the end of 2020, with all sites having a design value of 0.082 ppm or less.

Taken together, the results from all of these analyses in dicate the Western Mojave Desert Planning Area will not attain the federal 8-hour ozone standard by 2010, the area’s a current deadline as a Moderate ozone nonattainment area. However, given the recent trends, the transport impact from the South Coast and S an Joaquin Valley, and the expected level and timing of emissions reductions in these upwind areas, the Western Mojave Desert can expect to reach attainment by the end of 2020, consistent with the June 15, 2021 attainment deadli ne for Severe-17 nonattainment areas.