# Ozone Redesignation Request and
Maintenance Plan

Clark County, Nevada

March 2011Ozone Request for Redesignation and Maintenance Plan

March 2011 ii ACKNOWLEDGMENTS

CLARK COUNTY BOARD OF COMMISSIONERS Susan Brager, Chair Steve Sisolak, Vice-Chair Larry Brown
Tom Collins Chris Giunchigliani

Mary Beth Scow Lawrence Weekly

OFFICE OF THE COUNTY MANAGER Don Burnette, County Manager Edward Finger, Assistant County Manager

Randy Tarr, Assistant County Manager Jeff Wells, Assistant County Manager

DEPARTMENT OF AIR QUALITY AND ENVIRONMENTAL MANAGEMENT Lewis Wallenmeyer, Director Tina Gingras, Assi stant Director Dennis Ransel, Planning Manager Stephen Deyo, Assistant Planning Manager Robert Tekniepe, Princi pal Management Analyst Zheng Li, Sr. Air Quality Modeler Will Cates, Principal Planner Jean Paul Huys, Air Quality Specialist II Melissa Hamner, Technical WriterOzone Request for Redesignation and Maintenance Plan

March 2011 iii EXECUTIVE SUMMARY

This Ozone Redesignation Request and Maintenance Plan is a formal request by Clark County to the U.S. Environmental Protection Agency (E PA) to redesignate the Clark County ozone
nonattainment area to attainment for the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). The plan summarizes th e progress in attaining the ozone standard, demonstrates that all Clean Air Act (CAA) as amended requirements for attainment have been met, and presents a plan to assure conti nued attainment over th e next ten years.

Clark County was designated nonattainment of the 8-hour ozone NAAQS in April 2004. The Phase 1 Implementation Rule issued by EPA on June 15, 2004 classified Clark County as a
“basic” nonattainment area under Subpart 1 of the Clean Air Act. Following the April 2004 designation, the state of Nevada submitted to EPA a request to reconsider the boundaries of the nonattainment designation for Clark County. EPA accepted the Nevada recommendations and issued a final rule in Septem ber 2004 delineating those boundaries.

On December 22, 2006, the United States Court of A ppeals for the District of Columbia Circuit vacated the Phase 1 Implementation Rule. EPA and other entities petitioned for a rehearing. On June 8, 2007, the court reviewed its decision and decided to vacate only certain portions of the rule, including the classification determinations for areas designated under Subpart 1 of the CAA. Following the court’s decision, EPA issued a memorandum (dated 6/15/2007) stating that nonattainment areas classified under “Subpart 1 ar e not currently subjec t to the June 15, 2007
submission date for their attainment demonstrati ons” and established a transportation conformity rule allowing states in nonattainment to subm it an Early Progress Plan (EPP). The EPP was to
allow nonattainment areas to establish motor ve hicle emission budgets (MVEB) that address the ozone NAAQS in advance of a complete attainme nt demonstration. Th ese actions obligated Clark County to develop the Eight Hour Early Progress Plan for Clark County. . The Board of County Commissioners adopted and approve d the Plan on June 17, 2008 which was subsequently submitted to the EPA. In May 2009, EPA formally approved the Plan.

This plan provides an ozone attainment demons tration that makes use of the most recently adopted planning variables, (e.g., vehicle miles traveled projections and population forecasts) approved by the designated Metropolitan Planni ng Organization for the Las Vegas urban area, (i.e., the Regional Transportatio n Commission of Southe rn Nevada). The plan also provides, among other things, revised emissi on inventories and updated MVEBs.

After EPA approval, the plan will become a federa lly enforceable plan that identifies how Clark County will maintain the 1997 ozone NA AQS through 2022. Once approved, the MVEBs contained in the plan will become the proj ected budgets that the Regional Transportation Commission will use for transportation conformity determinations in future regional transportation plans.Ozone Request for Redesignation and Maintenance Plan

March 2011 iv TABLE OF CONTENTS

1.0 PLAN OVERVIEW ....................................................................................................... 1-1

1.1 Introduction .......................................................................................................... 1-1

1.2 Characteristics and Health Effects of Ozone ....................................................... 1-1

1.3 National Ambient Air Quality Standards for Ozone ............................................ 1-2

1.4 History of the Clark County Nonattainment Area ............................................... 1-2
1.5 Required Components of a Redesignation Request ............................................. 1-5
1.5.1 Attainment of the Standard ...................................................................... 1-5
1.5.2 Approved Implementation Plan under Section 110(k) ............................ 1-5
1.5.3 Permanent and Enforceable Improvements in Air Quality ...................... 1-5
1.5.4 Requirements under Section 110 and Part D ........................................... 1-5
1.5.5 Approvable Maintenance Plan under Section 175(a) .............................. 1-5

2.0 ATTAINMENT OF THE OZONE STANDARD ....................................................... 2-1

2.1 Introduction .......................................................................................................... 2-1

2.2 Monitoring Network ............................................................................................ 2-1

2.3 Monitoring Results and Attainment Demonstration ............................................ 2-3

2.4 Quality Assurance Program ................................................................................. 2-4

3.0 STATE IMPLEMENTATION PLAN APPROVAL .................................................. 3-1

3.1 Introduction .......................................................................................................... 3-1

3.2 Previous Ozone State Implemen tation Plan Approvals ....................................... 3-1

4.0 PERMANENT AND ENFORCEABLE IMPROV EMENT IN AIR QUALITY ..... 4-1

4.1 Introduction .......................................................................................................... 4-1

4.2 Economic Conditions ........................................................................................... 4-1

4.2.1 Development Patterns .............................................................................. 4-1

4.2.2 Population Trends .................................................................................... 4-1
4.3 Meteorological Conditions................................................................................... 4-2

4.4 Attainment and Maintenance Control Measures .................................................. 4-3

4.4.1 Permanent and Enforceable Emission Reduction Control Measures ...... 4-4

4.4.1.1 Federal Tier 2 Vehicle Emission Standards ........................... 4-4

4.4.1.2 Federal Highway Diesel Rule ................................................ 4-4

4.4.1.3 Federal Large Nonroad Diesel Engines Rule ......................... 4-4

4.4.1.4 Federal Nonroad Spark-Igniti on Engines and Recreational Engines Standards .................................................................. 4-5
4.4.1.5 Federal Nonroad Spark-Igni tion Engines and Equipment
Standard ................................................................................. 4-5

4.4.1.6 State Vehicle Inspection and Maintenance Program ............. 4-5

4.4.1.7 Clark County Stationary Point and Nonpoint Source Regulations ............................................................................ 4-6

4.4.2 Additional Emission Reduction Control Measures .................................. 4-6

4.4.2.1 Regional Haze Rule ............................................................... 4-6

4.4.2.2 Actions by California Local Air Agencies ............................. 4-6

4.4.2.3 Alternative Fuels for Govern ment Fleets Program ................ 4-6Ozone Request for Redesignation and Maintenance Plan

March 2011 v 4.4.2.4 Transportation Control Measures/Transportation Demand Management Program ............................................................ 4-7
4.4.2.5 Ozone Action Days ................................................................ 4-7

4.4.2.6 Transportation Conformity .................................................... 4-7
4.5 Air Quality Trend Analysis: Weight of Evidence ................................................ 4-7

5.0 REQUIREMENTS FROM SECTION 110 AND PART D OF THE CLEAN AIR
ACT AMENDMENTS ................................................................................................... 5-1
5.1 Introduction .......................................................................................................... 5-1
5.2 Section 110 Requirements ................................................................................... 5-1
5.2.1 Section 110(a)(2) ..................................................................................... 5-1
5.2.2 Section 110(l) ........................................................................................... 5-2
5.3 Part D Requirements ............................................................................................ 5-2
5.3.1 Section 172(c) .......................................................................................... 5-2
5.3.2 Section 176(c) .......................................................................................... 5-2

6.0 MAINTENANCE PLAN ............................................................................................... 6-1

6.1 Introduction .......................................................................................................... 6-1

6.2 Transporation Input Data ..................................................................................... 6-1

6.3 efficiency and Effectiveness Factors ................................................................... 6-1

6.4 Emission Inventory Type Categories ................................................................... 6-2

6.4.1 Point Sources ........................................................................................... 6-2

6.4.2 Nonpoint Sources ..................................................................................... 6-2

6.4.3 Private and Commerci al Aviation ............................................................ 6-3

6.4.4 Federal Aviation....................................................................................... 6-3
6.4.5 Railway .................................................................................................... 6-3

6.4.6 On-Road Mobile ...................................................................................... 6-3

6.4.7 Nonroad Mobile ....................................................................................... 6-4
6.4.8 Biogenic ................................................................................................... 6-4
6.4.9 Banked Emission Reduction Credits ....................................................... 6-4
6.5 Summary of Emission Inventories ....................................................................... 6-5

6.6 Maintenance Demonstration ................................................................................ 6-9

6.7 Monitoring Network AND Verification of Continued Attainment ................... 6-11

6.8 Contingency Plan ............................................................................................... 6-11

6.8.1 Potential Contingency Measures ............................................................ 6-12

6.8.1.1 Reid Vapor Pressure Reduction ........................................... 6-12

6.8.1.2 Inspection/Maintenance Program Changes and Additions .. 6-12

6.8.1.3 Consumer and Commercial Products................................... 6-12

6.8.1.4 Architectural Surface Coatings ............................................ 6-12
6.8.1.5 Lawn and Garden Equipment Use ....................................... 6-12

6.8.1.6 Establish/Enhance Trip Reduction Programs ...................... 6-12

6.8.2 Tracking and Triggering Mechanisms ................................................... 6-13

6.8.3 Action Resulting from Trigger Activation ............................................. 6-13

6.9 Subsequent Maintenance Plan Revisions ........................................................... 6-13

7.0 MOTOR VEHICLE EMISSIONS BUDGETS ........................................................... 7-1Ozone Request for Redesignation and Maintenance Plan

March 2011 vi 8.0 REFERENCES ............................................................................................................... 8-1

APPENDICES

APPENDIX A: Clark County Ozone Redesignati on Request and Maintenance Plan Technical Support Document, December 2010 ................................................................ A-1

APPENDIX B: EPA Air Quality System , Design Value Report, 2006-2009 ............................B-1

APPENDIX C: Documentation of th e Public Review Process......................................C-1Ozone Request for Redesignation and Maintenance Plan

March 2011 vii LIST OF FIGURES

Figure 1-1. Areas in Clark C ounty Designated Nonattainment fo r the 8-hour Ozone NAAQS 1-4 Figure 2-1. Clark County Ozone Monitoring Stations ................................................................ 2-2 Figure 4-1. Actual and Linear (OLS) Ozone Trends .................................................................. 4-8 Figure 6-1. VOC Emission Inventory for 2008 .......................................................................... 6-6 Figure 6-2. VOC Emission Inventory for 2015 .......................................................................... 6-6 Figure 6-3. VOC Emission Inventory for 2022 .......................................................................... 6-7 Figure 6-4. NO

x Emission Inventory for 2008............................................................................ 6-8 Figure 6-5. NO

x Emission Inventory for 2015............................................................................ 6-8 Figure 6-6. NO

x Emission Inventory for 2022............................................................................ 6-9 Figure 6-7. Comparis on of 2008, 2015, and 2022 NO

x Emissions .......................................... 6-10 Figure 6-8. Comparison of 2008, 20 15, and 2022 VOC Emissions ......................................... 6-11

LIST OF TABLES

Table 2-1. Clark County Oz one Monitoring Sites ...................................................................... 2-1 Table 2-2. Three Year Average (ppm) of the 4th Highest Ozone Concentra tions (2006-2008) . 2-3 Table 2-3. Three Year Average (ppm) of the 4th Highest Ozone Concentra tions (2007-2009) . 2-3 Table 4-1. Clark County Popula tion History (1990-2009) .......................................................... 4-2 Table 4-2. Monthly Averages for Temperat ure and Rainfall (1937 to 2009) .............................. 4-3 Table 6-1. Demographic Data Used to Develop Emission Inventories ....................................... 6-1 Table 6-2. Summary of Total Da ily VOC Emissions (tpd) ......................................................... 6-5 Table 6-3. Summary of Total Daily NO

x Emissions (tpd) ........................................................... 6-7
Table 7-1. VOC and NO

x MVEBs for Clark County .................................................................. 7-1Ozone Request for Redesignation and Maintenance Plan

March 2011 viii ACRONYMS AND ABBREVIATIONS

Acronyms AQR Clark County Air Quality Regulation

BCC Clark County Board of County Commissioners

CAA Clean Air Act

CFR Code of Federal Regulations DAQEM Clark County Department of Air Quality & Environmental Management

DRI Desert Research Institute
EI Emission Inventory

EPA U.S. Environmental Protection Agency EQM Environmental Quality Management, Inc

ERC Emission Reduction Credit HPMS Highway Performance Monitoring System
I/M Nevada Vehicle Inspecti on and Maintenance Program MVEB Motor Vehicle Emission Budget NAAQS National Ambient Air Quality Standards
NAC Nevada Administrative Code
NDEP Nevada Division of Environmental Protection

NRS Nevada Revised Statues

RTC Regional Transportation Comm ission of Southern Nevada

SIP state implementation plan SLAMS State and Local Air Monitoring System TDM Transportation Demand Model

TSD Technical Support Document

VMT vehicle miles traveled

Abbreviations
CO carbon monoxide

NO

x nitrogen oxides PM particulate matter

ppm parts per million tpd tons per day
tpy tons per year VOCs volatile organic compoundsOzone Redesignation Request and Maintenance Plan

March 2011 1-1 1.0 

### PLAN OVERVIEW

1.1 INTRODUCTION

Clark County, in conjunction with the Nevada Division of Environmen tal Protection (NDEP), requests that the U.S. Environmental Protectio n Agency (EPA) redesignate the Clark County
ozone nonattainment area to attainment status for the 1997 8-hour National Ambient Air Quality Standards (NAAQS) for ozone.

To comply with EPA guidance, Clark County inventoried emissions of volatile organic compounds (VOCs) and nitrogen oxides (NO

x ) for the 2008 attainment year and projected those
emissions outward to 2015 and 2022. The inventories were then adjusted to reflect federal, state,
and local rules on VOC and NO

x emissions already adopted or im plemented; these controls were
shown to reduce overall ozone emissi ons through 2022, the maintenance year.

1.2 CHARACTERISTICS AND HEA LTH EFFECTS OF OZONE

Ozone is a gas composed of three oxygen atoms th at occurs both in Ea rth’s upper atmosphere (stratosphere) and at ground level (troposphere). Ozone in the stratosphere, which extends upward from 6 to 30 miles, occurs naturally and protects life from harmful ultraviolet rays. In the troposphere, ozone is a pollutant th at poses a significant health ri sk, especially for children, the elderly, and people with chronic il lnesses. It may also damage cr ops, trees, and other vegetation.

Ground-level ozone is not usually emitted directly into the air, but formed through chemical
reactions between NO

x and VOCs in the presence of sunlight . Vehicle exhaust, emissions from commercial and industrial sources, gasoline vapors, chemical solvents, and natural sources emit

NO

x and VOCs. Since sunlight is an important formative factor, ozone pollution is usually a summertime problem.

Ozone can irritate lung airways and cause an inflammation that rese mbles sunburn. Symptoms include wheezing, coughing, pain when taking a deep breath, and difficulty breathing during
exercise or outdoor activities. Ch ildren and those with respirat ory problems are particularly susceptible, but even healthy people who are active outdoors can be affected. Repeated exposure to ozone pollution over many months may cause permanent lung damage. Even when concentrations are low, ozone pollution ma y aggravate asthma, reduce lung capacity, and increase susceptibility to respiratory illnesses like pneum onia and bronchitis.

Ground-level ozone may also affect plants and ecosys tems. It interferes with the ability of plants to produce and store food, which makes them more su sceptible to disease, insects, harsh weather, and other pollutants. This in turn can impact crop and forest yields. In addition, ozone can damage the leaves of trees and other plants.

Ozone and its precursor pollutants may be tran sported hundreds of miles downwind from their original sources. Transport of po llutants from California into so uthern Nevada contributes to
ozone concentrations in Clark County during the summer months.Ozone Redesignation Request and Maintenance Plan

March 2011 1-2 1.3 NATIONAL AMBIENT AIR QUAL ITY STANDARDS FOR OZONE

There are two federal standards for ozone: a primar y standard that establishes limits to protect public health, including the health of sensitive populations such as asthmatics, children, and the elderly, and a secondary standard that sets limits to protect public welfare, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings. Both standards are identical for the 1997 ozone NAAQS: 0.08 parts per million (ppm).

1.4 HISTORY OF THE CLARK COUNTY NONATTAINMENT AREA

On March 3, 1978, EPA designated the Las Vegas Valley a nonattainment area for the ozone NAAQS in volume 43, page 8962 of the Federal Register (43 FR 8962). Air quality monitoring data for calendar years 1975 thr ough 1977 show violations of the 1-hour ozone NAAQS in effect at the time. That same month, Nevada’s gover nor designated the Clark County Board of County Commissioners (BCC) the responsi ble entity for preparing State Implementation Plans (SIPs) for Clark County; the BCC then delegated that respon sibility to the agency that is now DAQEM.

On February 8, 1979, the EPA established a prim ary 1-hour ozone NAAQS of 0.12 ppm (44 FR 8220). After EPA determined the Las Vegas Va lley was a nonattainment area for ozone, the county began requiring targeted industries to implement improve d control technologies that curbed precursor pollutants because research ha d shown that industrial processes within Clark County were contributing to elev ated ozone levels. By the end of 1984, control technologies had been fully implemented and Clark County had comp leted a SIP demonstrating attainment of the ozone NAAQS.

In January 1985, the Nevada governor submitted the Clark County ozone SIP to EPA for review and approval. This SIP demonstrated attainme nt of the 1-hour ozone NAAQS, in accordance with EPA requirements and federal law. In Apri l 1986, the state of Nevada requested that EPA redesignate the Las Vegas Valley as an attainme nt area, providing documentation that showed how control measures and technologies had resulted in improved air quality and compliance with the ozone NAAQS. EPA approved the SIP in August 1986, and on November 19, 1986, it redesignated the Las Vegas Valley as an attain ment area for the 1-hour ozone NAAQS effective January 20, 1987 (51 FR 41788).

On July 18, 1997, EPA revised the ozone NAAQS (62 FR 38856), replacing the 1-hour 0.12- ppm primary standard with an 8-hour 0.08 ppm standard that was based on the three-year average of the annual fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within a given area. This rule became effective September 16, 1997.

On June 27, 2003, Clark County submitted a re commendation to NDEP on the designation of Clark County under the 1997 8-hour ozone NAAQS. At th e time, the data for the past three years (2000, 2001, and 2002) indicated that Clark County wa s in compliance with the 8-hour standard. On July 10, 2003, pursuant to Section 107(d) of the 1990 CAA, the state of Nevada submitted the recommended designations to EPA’s Region 9 office.Ozone Redesignation Request and Maintenance Plan

March 2011 1-3 In its response to the governor on Decembe r 3, 2003, EPA agreed with the state’s recommendation but noted that it was tracking 2003 ozone monitoring data. That data indicated that the standard was exceeded, if barely, at one location. Basing its final designation on 2001, 2002, and 2003 monitoring data, EPA designated Clark County in nonattainment of the 8-hour ozone NAAQS on April 15, 2004 (69 FR 23858) under the Title 1, Part D, Subpart 1 of the Clean Air Act (CAA).

On May 21, 2004, the Nevada governor requested that EPA delay the effective date of its nonattainment designation for Clark County until October 15, 2004, and on June 18, EPA promulgated a final rule defe rring the effective date to Se ptember 13, 2004 (69 FR 34076). The agency agreed that relevant factors for defi ning a nonattainment area might support a different
recommendation than the one the state had submitted on April 12, 2004. On August 2, 2004, the state submitted a revised recommendation that encompassed the following areas in Clark County:

 Ivanpah Valley (Hydrographic Areas 164A, 164B, 165, and 166).

 Eldorado Valley (Hydr ographic Area 167).

 Las Vegas Valley (Hydrographic Area 212).

 Colorado River Valley (Hydrographic Area 213).

 Paiute Valley (Hydrographic Area 214).

 Apex Valley (Hydrographic Areas 216 and 217).

 A portion of Moapa Valley (Hydrographic Area 218).

Figure 1-1 shows the areas within Clark County designated as basic nonattainment for the 8-hour ozone standard. EPA accepted the state’s recomme ndations and issued a final rule in September 2004 delineating the revised boundaries.

On December 22, 2006, a three-judge panel from th e U.S Court of Appeals for the District of Columbia Circuit vacated the Phase 1 Implem entation Rule (472 F. 3d 882 (D.C. Cir. 2006)). EPA and other organizations filed petitions fo r a rehearing. On June 8, 2007, the entire court
reviewed the decision to vacate the rule and d ecided to vacate only certain portions, including the classification determinations for areas designated under Title I, Part D, Subpart 1 of the CAA. Following the court’s decision, EPA issued a memorandum (dated 6/ 15/2007) stating that nonattainment areas classified under “Subpart 1 ar e not currently subjec t to the June 15, 2007
submission date for their attainment demonstrat ions.” These actions obligated Clark County to develop and submit to EPA in 2008 the 8-Hour Ozone Early Progress Plan for Clark County,
Nevada (DAQEM 2008a) to establish motor vehicle emission budgets (MVEBs) for maintaining transportation conformity. The Board of Count y Commissioners adopted and approved the EPP on June 17, 2008. EPA formally approved these MVEBs on May 14, 2009 (74 FR 22738)

.Ozone Redesignation Request and Maintenance Plan

March 2011 1-4 Figure 1-1. Areas in Clark County Designa ted Nonattainment for the 8-hour Ozone NAAQSOzone Redesignation Request and Maintenance Plan

March 2011 1-5 1.5 REQUIRED COMPONENTS OF A REDESIGNATION REQUEST

CAA Section 107(d)(3)(E) defines the five cond itions that must be met before EPA can redesignate a nonattainment area to attain ment. With the submittal of this plan

, Clark County
meets these five conditions.

1.5.1 Attainment of the Standard

Clark County must show that the area is attaini ng the applicable NAAQS. Redesignation of
ozone nonattainment areas to attainment is based solely on ambient air quality data. Section 2 presents the data that demonstrate Clark County’s attainment of the 1997 ozone NAAQS.

1.5.2 Approved Implementation Plan under Section 110(k)

Clark County must have a SIP fully approved und er CAA Section 110(k) and must satisfy all requirements that apply to the nonattainment area . Section 3 discusses Clark County’s ozone SIP development. Section 110(k) addresses complete ness findings, deadlines for EPA actions, types of EPA actions, and sanctions th at may be applied to areas failing to meet Clean Air Act requirements.

1.5.3 Permanent and Enforceable Im provements in Air Quality

Clark County must be able to reasonably attrib ute the improvement in air quality to emission reductions that are permanent and federally en forceable. Section 4 shows that improved air quality in the Clark County area is the result of permanent and enforceable emission reduction control measures, as opposed to adverse economic or meteorological conditions.

1.5.4 Requirements under Section 110 and Part D

Clark County must meet all requi rements of CAA Section 110 and Pa rt D that applied before the submittal of the redesignation request. Section 5 describes how this SIP does not interfere with any requirements for attainment of the oz one NAAQS, reasonable fu rther progress towards
attainment of all othe r criteria pollutant NAAQS, or any other applicab le CAA requirement.

1.5.5 Approvable Maintenance Plan under Section 175(a)

CAA Section 107(d)(3)(E) stipulates that EPA must fully approve a maintenance plan that meets the requirements of Section 175(a) before it can redesignate an area to attain ment. Section 6 provides a plan to maintain compliance with the ozone NAAQS for at least ten years after redesignation.Ozone Redesignation Request and Maintenance Plan

March 2011 2-1 

### 2.0 ATTAINMENT OF THE OZONE STANDARD

2.1 INTRODUCTION

The first required component of an area’s redesignation request is a demonstration that it has attained the NAAQS. Attainment of the 1997 ozone standard is demonstrated through the establishment of a design value, which is based on the three-year average of the annual fourthhighest daily maximum 8-hour average ozone con centrations measured at each monitor. The fourth-highest daily maximum 8-hour average ozone concentration may not exceed 0.084 ppm.

This section demonstrates, as required by CA A Section 107(d)(3)(E), that Clark County has attained the 1997 ozone NAAQS. The attainment demonstration is based on quality-assured monitoring data representative of the Clark County ozone nonattainment area.

2.2 MONITORING NETWORK

Title 40, Part 58 of the Code of Federal Regulations (40 CFR 58) defines the requirements for the ambient air quality monito ring programs mandated by the C AA. The current Clark County ozone monitoring network consists of 8 State and Local Air Moni toring Stations (SLAMS). As Table 2-1 shows, the monitoring objective of most sites is “population exposure.” The exceptions are Jean, which monitors regional tr ansportation, and Joe Neal, whose monitoring objective is “highest concentration.” Clark C ounty’s monitoring system is governed by quality assurance and quality contro l procedures approved by EPA and subject to periodic EPA performance audits.

Table 2-1. Clark County Ozone Monitoring Sites

Site Name Site Code Address Monitoring Objective

Paul Meyer 32-002-0043 4525 New Forest Dr., Las Vegas 89147 Population exposure

Walter Johnson 32-002-0071 7701 Ducharme Ave., Las Vegas 89145 Population exposure

Palo Verde 32-003-0073 333 Pavilion Center Dr., Las Vegas 89144 Population exposure

Joe Neal 32-003-0075 6651 Azure Way, La s Vegas 89130 Highest concentration

Winterwood 32-0030-538 5483 Club House Dr., Las Vegas 89142 Population exposure

Boulder City 32-003-0601 1005 Industrial, Boulder City 89005 Population exposure

Jean 32-003-1019 1965 State Highway 161, Jean 89019 Regional transportation

J.D. Smith 32-003-2002 1301B Tonopah Ave., No rth Las Vegas 89030 Population exposure

Figure 2-1 shows the locations of Clark County ozone monitoring stations . Tables 2-2 and 2-3 show the three-year averages of the fourth-highest ozone concentrations measured at these stations during 2006–2008 and 2007–2009, respectively.Ozone Redesignation Request and Maintenance Plan

March 2011 2-2 Figure 2-1. Clark County Ozone Monitoring StationsOzone Redesignation Request and Maintenance Plan

March 2011 2-3 Thirteen ozone monitoring stations were in operation during the time period 2006-2009. Monitoring data from 2006-2008 and 2007-2009 is used to show that Clark County is in attainment of the 1997 ozone NAAQS.

Table 2-2. Three Year Average (ppm) of the 4t h Highest Ozone Concentrations (2006-2008)

Site Name Site Code 2006 2007 2008 Design V alue
2006-2008
Craig Road 32-003-0020 0. 079 0.075 0.071 0.075
Apex 32-003-0022 0.079 0.081 0.071 0.077
Mesquite 32-003-0023 0.069 0.065 0.069 0.067
Paul Meyer 32-002-0043 0. 083 0.083 0.077 0.081

Walter Johnson 32-002-0071 0.085 0.085 0.076 0.082

Lone Mountain 32-003-0072 0.085 0.080 0.078 0.081

Palo Verde 32-003-0073 0.084 0.081 0.074 0.079

Joe Neal 32-003-0075 0. 083 0.081 0.080 0.081

Winterwood 32-0030-538 0. 078 0.076 0.071 0.075
Boulder City 32-003-0601 0. 074 0.076 0.071 0.073

Jean 32-003-1019 0.079 0.083 0.074 0.078

Orr 32-003-1021 0.085 0.077 0.074 0.078

J.D. Smith 32-003-2002 0. 081 0.080 0.068 0.076

Source: EPA Air Quality System, 2006-2008 (Appendix B).

Table 2-3. Three Year Average (ppm) of the 4t h Highest Ozone Concentrations (2007-2009)

Site Name Site Code 2007 2008 2009 Design Value
2007-2009
Craig Road 32-003-0020 0. 075 0.071 0.072 0.072
Apex 32-003-0022 0.081 0.071 0.070 0.074
Mesquite 32-003-0023 0.065 0.069 0.062 0.065
Paul Meyer 32-002-0043 0. 083 0.077 0.071 0.077

Walter Johnson 32-002-0071 0.085 0.076 0.074 0.078

Lone Mountain 32-003-0072 0.080 0.078 0.072 0.076

Palo Verde 32-003-0073 0.081 0.074 0.072 0.075

Joe Neal 32-003-0075 0. 081 0.080 0.074 0.078

Winterwood 32-0030-538 0. 076 0.071 0.070 0.072
Boulder City 32-003-0601 0. 076 0.071 0.071 0.072

Jean 32-003-1019 0.083 0.074 0.072 0.076

Orr 32-003-1021 0.077 0.074 0.071 0.074

J.D. Smith 32-003-2002 0. 080 0.068 0.072 0.073

Source: EPA Air Quality System, 2007–2009 (Appendix C).

2.3 MONITORING RESULTS AND ATTAINMENT DEMONSTRATION

The monitoring data presented in Tables 2-2 and 2-3 verify that the Cl ark County nonattainment
area has been in attainment with the ozone NAA QS since 2008, including the most recent threeyear period of 2007–2009, in accordance with the fe deral requirements of 40 CFR 58. The data also depict a downward trend in ozone concentr ations in the Clark County nonattainment area.Ozone Redesignation Request and Maintenance Plan

March 2011 2-4 2.4 QUALITY ASSURANCE PROGRAM

Ozone data have been collected and verifi ed in accordance with 40 CFR 58, Appendix A, “Quality Assurance Handbook for Air Pollution Meas urement Systems, Volume II: Ambient Air Monitoring Program,” and the DAQEM Quality Control and Assu rance System for Criteria
Gaseous Pollutants (DAQEM 2008b).

Ozone data are submitted to EPA’s Air Quality System database and are available for public review in the annual network plan Clark County submits to EPA. The data are also posted on the Air Quality Index page of Cl ark County’s Web site and ar e reported in local media.Ozone Redesignation Request and Maintenance Plan

March 2011 3-1 

### 3.0 STATE IMPLEMENTATION PLAN APPROVAL

3.1 INTRODUCTION

The second required component of an area’s redesignation request is a fully approved SIP satisfying all the requirements that apply to the nonattainment area under CAA Section 110(k), which addresses completeness findings, deadlines for EPA actio ns, types of EPA actions, and sanctions that may be applied to areas failing to meet CAA requirements.

3.2 PREVIOUS OZONE STATE IMP LEMENTATION PLAN APPROVALS

The Phase 1 Implementation Rule issued by EPA in April 30, 2004, classified Clark County as a “basic” nonattainment area under Subpart 1 of th e CAA, effective June 15, 2004 (69 FR 23858). Following this designation, the state of Nevada submitted to EPA a request to reconsider the boundaries of the Clark County nonattainment ar ea. EPA accepted the Nevada recommendations and issued a final rule in September 2004 delineating those bounda ries (Section 1.3).

In December 2006, the U. S. Court of Appeals for th e District of Columbia Circuit (D.C. Circuit) vacated the Phase 1 Implementation Rule. EPA i ssued a memorandum in June 2007 stating that nonattainment areas previously classified under S ubpart 1 were no longer subject to the June
2007 submittal date for their attainment demonstr ations. EPA then established a transportation conformity rule allowing nonattainment areas to submit early progress plans containing early MVEBs that addressed the ozone NAAQS be fore submitting a complete attainment demonstration. Clark County developed the 8-Hour Ozone Early Progress Plan for Clark County, Nevada (DAQEM 2008a) and submitted it to EPA in June 2008 to establish MVEBs, and EPA formally approved the MVEBs on May 14, 2009 (74 FR 22738)

.

In nonattainment areas where monitored data demonstrate the NAAQS have already been achieved, EPA has determined that certain requirem ents of Part D, Subparts 1 and 2 of the CAA do not apply. Therefore, Clark County does not requi re certain submissions for an area that has attained the NAAQS. These include reasonable fu rther progress (RFP) requirements, attainment demonstrations, reasonably available control measures (RACM), and contingency measures, because these provisions have the purpose of helping achieve attainment of the NAAQS.

This interpretation of the CAA is known as the Clean Data Policy and is the subject of two EPA memoranda. EPA also finalized the statutory interpretation set forth in the policy in its final rule, 40 CFR 51.918, as part of its “Final Rule to Implement the 8-hour Ozone NAAQS—Phase 2” (Phase 2 Final Rule) – see discussion in the preamble to the rule at 70 FR 71612, 71645-46 (November 29, 2005). The D.C. Circ uit (2009) upheld this Clean Data regulation as a valid interpretation of the CAA in NR DC v. EPA, 571 F. 3d 1245. EPA also finalized its interpretation in a regulation that was part of it s Implementation Rulemaking for the PM 2.5 NAAQS (40 CFR 51.1004(c)). Thus, EPA has codified the policy when it established final rules governing implementation of new or revised NAAQS for the pollutants (70 FR 71612, 71644-46 (November 29, 2005) (ozone); 72 FR 20585, 20665 (April 25, 2007) (PM 2.5 )). Otherwise, it applies the policy in indi vidual rulemakings related to specific nonattainmen t areas, (i.e., 75 FR 6571 (February 10, 2010)). EPA believes that the legal bases set forth in detail in EPA’s Phase 2Ozone Redesignation Request and Maintenance Plan

March 2011 3-2 Final rule, (i.e., May 10, 1995 memorandum from John S. Seitz, entitled “Reasonable Further Progress, Attainment Demonstration, and Rela ted Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard,” the PM 2.5 implementation rule, and the December 14, 2004 memorandum from Stephen D. Page entitled “Clean Data Policy for the Fine Particle National Ambient Air Quality Standards”), are equally pertinent to the interpretation of provisions of S ubparts 1 and 4 applicable to PM 10 . Our interpretation that an area that is attaining the standard s is relieved of obligations to demonstrate RFP and to provide an attainment demonstration, RACM and continge ncy measures pursuant to Part D of the CAA, pertains whether the standard is PM 10 , ozone or PM 2.5

.

The monitoring data presented in Tables 2-2 an d 2-3 of Section 2.2 verify the Clark County
nonattainment area has been in attainment with the ozone NAAQS since 2008, including the most recent three-year period of 2007–2009.Ozone Redesignation Request and Maintenance Plan

March 2011 4-1 

### 4.0 PERMANENT AND ENFORCEABL E IMPROVEMENT IN AIR QUALITY

4.1 INTRODUCTION

The third required component of an area’s rede signation request is a demonstration that the improvement in air quality is reasonably attributed to emission reductions that are permanent and federally enforceable. This section demonstrates that improved air quality in the Clark County ozone nonattainment area is the result of perm anent and enforceable emission reduction control measures, as opposed to adverse econo mic or meteorological conditions.

4.2 ECONOMIC CONDITIONS

Clark County, formed in 1909, totals more than 8,000 square miles in area and is located at the southern tip of the state. Most residents live in the Las Vegas Valley, a 600-square-mile basin in the middle of the county. In addition to hosting up to 40 million visitors a year, Las Vegas has been one of the fastest growing cities in the nation for 25 year s. This rapid population growth and accompanying development led to increased em issions of pollutants and, beginning in 2001, ozone concentrations in Clark County approach ed (and sometimes exceeded) the 8-hour ozone NAAQS.

4.2.1 Development Patterns

More than 90 percent of the la nd in Clark County is owned by fe deral agencies and restricted from public use. The U.S. Bureau of Land Management (BLM) has the largest holdings, including the Red Rock National Conservation Area west of Las Vegas. Most of the Spring Mountain Range, including Mt. Charle ston, is administered by the U.S. Forest Service as part of the Toiyabe National Forest.

Urbanized land is concentrated in the Las Vegas Valley and incl udes the cities of Las Vegas, Henderson, and North Las Vegas, as well as unincorporated areas of Clark County. These communities contain the highest population densities and corresponding roadway networks. Traffic volumes are increasing every year beca use of population growth and development.

Although emissions from mobile and nonpoint sources in Clark County originate primarily in the Las Vegas Valley, nearby areas co ntain significant industrial s ources of pollution. The Apex Industrial Park, 20 miles nor theast of Las Vegas, is home to many sources of NO

x . Power plants such as the Reid Gardner facility ne ar Moapa are a significant source of NO

x .

4.2.2 Population Trends

More than 95 percent of Clark County’s popul ation resides in the Las Vegas Valley. But communities outside the valley have also experi enced significant growth in the past 20 years, including Mesquite, on the county’ s northeastern edge, and Laughli n, at the county’s southern end. Table 4-1 provides population data in Clark County from 1990 to 2009, and Appendix A contains Clark County population projections for future years. Clark County experienced aOzone Redesignation Request and Maintenance Plan

March 2011 4-2 population decrease of less than one per cent between 2008 and 2009, but this likely has not had
an effect on overall ozone c oncentrations in the county.

Table 4-1. Clark County P opulation History (1990-2009)

Year Population Annual Population Change Annual Percent Increase

1990 770,280 — — 1991 835,080 64,800 8%

1992 873,730 38,650 5%

1993 916,837 43,107 5%

1994 990,564 73,727 8%

1995 1,055,435 64,871 7%

1996 1,119,052 63,617 6%

1997 1,193,388 74,336 7%

1998 1,261,150 67,762 6%

1999 1,327,145 65,995 5%

2000 1,394,440 67,295 5%

2001 1,485,855 91,415 7%

2002 1,549,657 63,802 4%

2003 1,620,748 71,091 5%

2004 1,715,337 94,589 6%

2005 1,796,380 81,043 5%

2006 1,874,837 78,457 4%

2007 1,954,319 79,482 4%

2008 1,967,716 13,397 <1%

2009 1,952,040 -15,676 - <1%

Source: Center for Business and Economic Research, UNLV (2010).

4.3 METEOROLOGICAL CONDITIONS

Located in the Mojave Desert, Clark County has four well-defined seasons. Summers display the
classic characteristics of the desert Southwest: da ily high temperatures in the lower elevations often exceed 100oF, with lows in the 70s. There ha s been no change in weather patterns over the
last decade.

The summer heat is usually tempered by low relative humidity, which may increase for several weeks during July and August in association with moist monsoonal wind flows from the south. This is the most common period for thundersto rms in the valley, which can result in flash flooding. Temperatures during the spring and fall are generally m oderate. Strong winds are the most persistent weather hazard: although winds higher than 50 miles per hour are infrequent, they often happen during vigorous storms.

Winters are generally mild and pleasant. After noon temperatures average 60oF, and the sky is normally clear and sunny. Snow accumulation on valley floors is rare; however, higher elevations, such as the Spring Mountains, typica lly receive 5–10 feet of snowfall annually. Based
on measurements from McCarran International Air port over the past thirty years, temperatures fall below 32oF an average of 24 days a year.Ozone Redesignation Request and Maintenance Plan

March 2011 4-3 Average annual rainfall in the valley, measur ed at McCarran Intern ational Airport, is approximately 4.16 inches. Table 4- 2 lists temperature and rainfa ll averages in Clark County
over the last seven decades.

Table 4-2. Monthly Averages for Temperature and Rainfall (1937 to 2009)

Month Maximum (  F) Minimum (  F) Average (  F) Rainfall (inches)

January 57.1 34.5 47.0 0.52
February 62.5 38.9 52.2 0.58

March 69.5 44.3 58.3 0.45
April 78.2 51.7 66.0 0.20
May 88.5 61.1 75.4 0.15

June 98.6 69.9 85.6 0.07
July 104.6 76.5 91.2 0.43
August 102.2 74.8 89.3 0.44
September 94.7 66.6 81.3 0.32

October 81.3 54.3 68.7 0.25

November 66.5 42.0 55.0 0.36

December 57.2 34.7 47.0 0.40
Annual Average 80.1 54.1 68.1 4.16

Source: Western Regional Climate Center (2010).

Local meteorology and general weather patterns in the Southwest have a significant effect on the valley’s air quality. Stagnant c onditions and low wind speeds can build up concentrations of ozone and precursor pollutants in the valley; wi nds from the southwest or west can transport ozone and other pollutants into Clark County. Wind speed and direction affect ozone levels in different areas at different times, and complex terra in features influence local flows within, into, and out of neighboring basins. Ozone concentrations in the Las Vegas Valley can therefore differ significantly, depending on lo cation and time of day.

4.4 ATTAINMENT AND MAINTENANCE CONTROL MEASURES

This plan demonstrates maintenance of the 1997 ozone NAAQS through 2022 using seven permanent and enforceable emissi ons reduction control measures:

1. Federal Tier 2 vehicle emissions standards (65 FR 6822).

2. Federal highway diesel rule (66 FR 5001).

3. Federal large nonroad diesel engines rule (69 FR 38958).

4. Nonroad spark-ignition engines and recr eational engines stan dards (65 FR 76789).

5. Federal nonroad spark-ignition engines and equipment standards (73 FR 59034).

6. Nevada vehicle inspection and maintenance (I/M) program (Nevada Revised Statutes (NRS) 445B and Nevada Administ rative Code (NAC) 445B).Ozone Redesignation Request and Maintenance Plan

March 2011 4-4 7. Clark County stationary point and nonpoint source air qu ality regulations (AQRs).

Section 4.4.1 discusses each of th ese seven measures. Section 4.4.2 describes additional emission reduction control measures that provide further ozone reductions, but are not quantified in the emission inventories (EIs).

4.4.1 Permanent and Enforceable Emission Reduction Control Measures

The seven emission reduction control measures us ed for quantitative emission reductions in the ozone maintenance plan are described below. These measures, which are permanent and enforceable, will remain in place through the maintenance ye ar of 2022 and will ensure continued ozone emission reductions throughout the nonattainment area, as demonstrated in
Section 6.6.

4.4.1.1 Federal Tier 2 Vehicle Emission Standards

The Tier 2 standards require all passenger vehicles in a manufacturer’s fl eet, including light-duty trucks and sport utility vehi cles, to meet an average standard of 0.07 grams of NO

x per mile. Implementation of Tier 2 standards began in 20 04, and most vehicles had been phased in by
2007. Federal Tier 2 standards also cover passenger vehicles over 8,500 pounds gross vehicle weight rating (e.g., large pickup trucks, sport utility vehicles), which were not covered by the previous Tier 1 regulations. Ph ase-in for these vehicles bega n in 2008, with full compliance
achieved in 2009.

The Tier 2 rule also reduced the sulfur conten t of gasoline from major refineries to 30 ppm starting in January 2006; before then, most su mmertime gasoline sold in Clark County had a sulfur content of about 300 ppm. Emission reducti ons from the federal Tier 2 standards have been primarily responsible for a large decrease in ozone concentrati ons in Clark County.

4.4.1.2 Federal Highway Diesel Rule

Beginning with the 2007 model y ear, this rule reduced emi ssions from heavy-duty diesel vehicles by more than 90 percen t. Additionally, the rule led to a 97 percent reduction in the sulfur content of highway diesel fuel. Previous levels were between 500 pp m (low sulfur diesel) and 15 ppm (ultra-low sulfur diesel). Advanced pollution control technology for cars, trucks, and buses allowed engine manufacturers to meet 2007 emission standards. EPA estimated this rule
would eliminate 2.6 million tons of NO

x emissions from heavy-duty ve hicles each year once the program was fully implemented, equivale nt to a 95 percen t reduction in NO

x emissions when compared to older diesel engines us ing higher-content sulfur diesel.

4.4.1.3 Federal Large Nonroad Diesel Engines Rule

This rule, promulgated in 2004, applies to larg e nonroad diesel engines like those used in construction, agricultural, and industrial equipment. EPA began phasing in the program in 2008,
and is scheduled to finish in 2014. The rule reduces the allowable sulfur in nonroad diesel fuel to 15 ppm by 2010. The combined engine and fuel rules should reduce NO

x emissions from largeOzone Redesignation Request and Maintenance Plan

March 2011 4-5 nonroad diesel engines by over 90 percent when compared to older nonroad engines using higher-content sulfur diesel.

4.4.1.4 Federal Nonroad Spark-Ignition Engine s and Recreational Engines Standards

In 2003, this standard began regulating NO

x and VOCs for groups of previously unregulated nonroad engines, including larg e spark-ignition engines (e.g., forklifts, airport ground service equipment), recreational vehicles (e.g., off-highway motorcycles), and recreational marine diesel engines. In Clark County, the st andards on large spark-ignition e ngines and recreational vehicles
have contributed the most to reducing local ozone concentrations. EPA estimates that by 2020,
the standard will reduce NO

x emissions from these types of equipment by 80 percent and VOC emissions by 72 percent.

4.4.1.5 Federal Nonroad Spark-Ignition Engines and Equipment Standard

In 2011, this standard will start regulating NO

x , VOCs, and carbon monoxide (CO) from all new land-based spark-ignition engine s running at or below 19 kilo watts (e.g., lawn and garden equipment, utility vehicles, generators) and from spark-ignition engines used in marine vessels (e.g., outboard engines, personal watercraft, ster n drive/inboard engines) . The standard also adopts new evaporative emissions standards to control permeation from these engines. In Clark County, the standards on small engi nes used in lawn and garden e quipment, utility vehicles, and generators will contribute the most to reducing lo cal ozone concentrations. EPA estimates that by 2020, the standard will reduce NO

x emissions from these types of equipment by 46 percent and VOC emissions by 33 percent.

4.4.1.6 State Vehicle Inspection and Maintenance Program

Chapter 445B in the NRS and the NAC set forth the regulations governing motor vehicles in Clark County. Adopted in 1978 and administered by the Nevada Department of Motor Vehicles, these regulations establish a nnual testing procedures for 1968 or newer gasoline-powered vehicles, regardless of size, an d for diesel-powered vehicles w ith a manufacturer’s gross vehicle weight rating of up to 10,000 pounds. The Nevada I/M program allows exemptions from emission testing for new vehicles on their firs t and second registration, new hybrid-electric vehicles during their first five model years, alte rnative fuel vehicles, vehicles registered as Classic Rods or Classic Vehicles and driven 2,500 miles or less per year, a nd vehicles registered as Replica Vehicles.

On-board diagnostic testing pr ocedures are used for 1996 a nd newer vehicles, while older vehicles are tested with a two-speed idle test . The I/M program also includes waiver provisions for motorists who spend $450 on emission-related re pairs. No waivers are allowed for vehicles
that emit visible smoke.Ozone Redesignation Request and Maintenance Plan

March 2011 4-6 4.4.1.7 Clark County Stationary Point and Nonpoint Source Regulations

Stationary sources in the Clark County nonattainm ent area are generally industrial, commercial, or institutional sources that emit 10 tons per year (tpy) or more of VOCs, 25 tpy of NO

x , and 100 tpy of any other criteria pollutant . Any source that generates, or ha s the potential to generate, at least 10 tpy of any single hazardous air pollutant (HAP) or 25 tpy of aggregate HAPs must report emissions. Nonpoint sources are commercial, sm all-scale industrial a nd residential sources whose emissions fall below poi nt source reporting levels, and which are too numerous or too small to identify individually.

Clark County has numerous regulations in place for stationary and nonpoint sources, notably AQR Sections 12.0 through 12.13, and Sections 13, 14, 16, 19 and 21. Clark County also regulates nonpoint sources, incl uding gasoline-dispensing facil ities, through the Stage II vapor recovery requirements in AQR Section 52, “Gas oline Dispensing Facilities.” Clark County enforces several federal regulations, such as 40 CFR Part 60, “Standards of Performance for New Stationary Sources, 40 CFR Part 61, “National Emission St andards for Hazardous Pollutants,” and 40 CFR Part 63, “National Emission Standa rds for Hazardous Air Pollutants for Source Categories,” to control emissions.

4.4.2 Additional Emission Re duction Control Measures

The Las Vegas Valley also benefits from the regi onal, state, and local ozone control programs listed below. Although these programs are not quantif ied in the EIs of this plan, they play an important role in reducing oz one levels in Clark County.

4.4.2.1 Regional Haze Rule

This rule, promulgated in July 1999, mandates emi ssion reductions to achieve natural visibility levels in mandatory Class I areas by 2064. Emi ssion reduction control measures principally address light-scattering and -a bsorbing aerosols, such as NO

x and VOC emissions. Several control measures will be implem ented throughout the western states : for example, Best Available Retrofit Technologies will be installed on older units to significantly reduce NO

x and VOCs. These controls will be operating by January 1, 2015, or no later than five years after approval of state regional haze SIPs, whichever comes firs t. Most western states , including Nevada, have submitted regional haze SIPs and are awaiting EPA approval.

4.4.2.2 Actions by California Local Air Agencies

Several local air agencies in California, such as the South Coast and San Joaquin Air Pollution Control Districts, are implementing control meas ures in conjunction w ith their SIPs. These control measures will likely reduce ozone transport into Clark County.

4.4.2.3 Alternative Fuels for G overnment Fleets Program

This program is designed to reduce motor vehicle emissions, including NO

x and VOCs, by regulating state and local governme nt fleets of more than 24 vehicles based in Clark County.Ozone Redesignation Request and Maintenance Plan

March 2011 4-7 Alternative fuels accepted by the program include methanol, ethanol or other alcohol 85 percent or greater by volume (E-85), compressed natural gas, liquefied petroleum gas, hydrogen, federal reformulated gasoline or its equi valent, ultra-low sulfur diesel, electricity, certain ethanol-diesel blends (e.g., O2DieselTM), and biodiesel from B5 to B100. Hybrid el ectric vehicles are
considered alternative fuel vehi cles if the electric motor is used as a propulsion device during parts of the vehicle’s drive cycle. As of fiscal year 2000, government fleets had to ensure that 90 percent of new vehicle purchases were alternative-fuel vehicles.

4.4.2.4 Transportation Control Measures/Tra nsportation Demand Management Program

In 1999, after adoption of the Transportation Improvement Plan FY 1998-2000 (RTC 1999), the Regional Transportation Commission of Southern Nevada (RTC) created Club Ride, a employerbased commuter services program. Major com ponents include employer/community outreach and marketing efforts, employer rideshare progra m incentives, preferential parking for carpoolers and vanpoolers, emergency rides home for Club Ride members, travel assi stance information on the Internet and at public kiosks, transit passe s to subsidize employees’ transit expenses, and partnerships with vanpool leasing companies. Although voluntary, this and other RTC programs play an important role in Clark C ounty’s efforts to reduce ozone levels.

4.4.2.5 Ozone Action Days

This public outreach and education program is a vol untary initiative asking local residents to take additional preventive actions when high ozone leve ls are predicted. Under certain meteorological conditions, Clark County meteorologists can fo recast when ground-level ozone may exceed health standards. On those days, Clark County faxes an air quality message to media outlets, government agencies, and other Ozone Action Da y participants. The department also makes Ozone Action Day messages and daily forecasts available to the public on its Web site. Preventive actions to reduce air pollution on thes e days include refueling vehicles after dusk, avoiding excessive driving, using pub lic transportation, and telecommuting.

4.4.2.6 Transportation Conformity

Clark County will continue to work closely with the RTC to assure that Regional Transportation Plans and Transportation Improvement Programs in the Clark County oz one nonattainment area
are consistent with and conform to Clark County’s air quality pr ogram, including the ozone SIP.

4.5 AIR QUALITY TREND ANALYSIS: WEIGHT OF EVIDENCE

Forecasting ozone concentrations in future year s carries some level of uncertainty, so Clark County performed an air quality trend anal ysis for the period between 2003 and 2009 using quality-assured data from the EPA Air Quality Syst em database (Figure 4-1) . The trend analysis would contribute to a weight-of-evidence approach to support the attainment demonstration of the ozone NAAQS with future-year VOC and NO

x MVEBs. This trend analysis also supports Section 4.4.1 – Permanent and Enforceable Emission Reduction Control Measures. Declining design values started with the implementation of the first Federal emission standard for engines in 2003. The 2007 design value went slightly up due to 3 consecutive intensive wildfire seasonsOzone Redesignation Request and Maintenance Plan

March 2011 4-8 in 2005, 2006 and 2007. The significant drop of the DV in 2009 can be contribu ted, in part, to the implementation of the Large Nonroad Engine rule; the source apportionment of the nonroad emissions category in 2008 was 33% for NOx and 20% for VOC.

This linear analysis, based on th e ordinary least squares, showed a continued downward trend of the design values. Clark County is confident that future ozone concentrati ons will continue to
trend downward with the maintenance control measures described in Section 4.4 in place.

Source: EPA Air Quality System, 2003-2010 (Appendix D).

Figure 4-1. Actual and Linear (OLS) Ozone Trends 86
85 85

83 86

82

78 y = ‐ 1.0357x + 87.714
R2 = 0.6042

70 72 74 76 78 80 82 84 86 88 90

2003 2004 2005 2006 2007 2008 2009OzoneConcentrations(ppb)

Years 

## Ozone Trend

Design Values Linear (Design Values) Tier II

Rule Heavy Duty Highway Rule

Nonroad Spark

Ingnition &

Recreational Large

Nonroad Engine

Rule Ultra Low

Sulfur Diesel

RuleOzone Redesignation Request and Maintenance Plan

March 2011 5-1 

### 5.0 REQUIREMENTS FROM SECT ION 110 AND PART D OF THE
CLEAN AIR ACT AMENDMENTS

5.1 INTRODUCTION

The fourth required component of a redesignation request is verification that Clark County meets CAA Section 110 and Part D requirements. Th is section provides that verification.

5.2 SECTION 110 REQUIREMENTS

Before EPA can redesignate the Clark County oz one nonattainment area, th e provisions of CAA Section 110(a)(2) and C AA Section 110(l) must be satisfie d. Section 110(a)(2) addresses the general requirements for SIPs; Section 110(l) pr events approval of SIP revisions if components of the plan would interfere w ith any applicable requirement concerning attainment, with reasonable further progress towards attainment of a NAAQS, or with any other applicable CAA requirement.

5.2.1 Section 110(a)(2)

This CAA section contains th e following SIP requirements:

1. Establishment and implementation of enforceable emission limitations.

2. Monitoring, compilation, and analysis of ambient air quality data.

3. Preconstruction review and permitting of new and modified major stationary sources.

4. Consultation with, and provisions for, the pa rticipation of affected local governments.

5. Assurance the state has adequate funds and au thority to enforce the SIP and associated regulations.

6. Establishment of permit fees for stationary sources.

NRS 445B.500 addresses the establishment, admi nistration, and enforcement of programs for controlling air pollution in Nevada. In Clar k County, these programs are administered and enforced by Clark County. The department ha s more than 100 staff members and an annual budget of approximately $28 million to administer , implement and enforce the CAA, including air quality plans and regulations applicable to the Clark County ozone nonattainment area.

Clark County’s current air program meets all provisions required by CAA Section 110(a)(2). If Clark County becomes unable to meet any of the provisions, NRS 445B.520 and 445B.530 allow
the State Environmental Comm ission to assume jurisdiction over the local air quality management program to ensure that CAA requi rements are met. EPA al so has authority to impose sanctions on a state if it “... finds that any requirement of an approved plan (or approved part of a plan) is not being implemented” (CAA, Section 179).Ozone Redesignation Request and Maintenance Plan

March 2011 5-2 5.2.2 Section 110(l)

CAA Section 110(l) requires that SIP revisions not interfere with requirements for attainment or reasonable further progress rega rding other criteria pollutant s, or with any other CAA requirements. Since this plan proposes no ch anges to current emissi on reductions control measures, it poses no interference with Clark Count y’s progress towards continued attainment of the CO or particulate matter NAAQS. Ne vada is currently designated as attainment/unclassifiable for particulate matter less than 2.5 microns in diameter under Section 107(d) of the CAA.

5.3 PART D REQUIREMENTS

Sections 172(c) and 176(c) in Part D of the CAA lay out require ments applicable to all areas designated as nonattainment because of a NAAQ S violation. Clark County was not classified under CAA Part D, so it is only subject to the general provisions of CAA Subpart 1,
“Nonattainment Areas in General.”

5.3.1 Section 172(c)

This section contains general requireme nts for maintenance plans, including:

1. Implementation of reasonably available cont rol measures, including reasonably available control technologies, for existing sources.

2. Reasonable further progre ss for existing sources.

3. A current EI, and periodic EIs every three years until attainment.

4. Identification and quantification of allowable emissions for new and modified stationary

sources.

5. Stationary source permitting program.

6. Other measures, including enforceable emission limitations, additional control measures, and a schedule for compliance.

7. Compliance with Section 110 provisions.

8. Contingency measures.

Clark County’s current air program , in conjunction with the components of this plan, meets all Section 172(c) provisions.

5.3.2 Section 176(c)

This section contains transportation and general conformity provisions app licable in maintenance areas. The transportation conformity process ensure s transportation plans, programs, and projects
in maintenance areas do not create new viola tions of the NAAQS, do not increase the frequencyOzone Redesignation Request and Maintenance Plan

March 2011 5-3 or severity of NAAQS violations, and do not de lay timely attainment of the NAAQS. It does not allow federal agencies to engage in, support, or provide financial assistance for licensing, permitting, or approving any project unle ss the project conforms to the SIP.

In approving the Clark County Transportation Conformity Plan (DAQEM 2008c) and the transportation conformity budgets in the 8-Hour Ozone Early Progress Plan for Clark County

, Nevada (DAQEM 2008a), EPA determined that Clark County met the Section 176(c) requirements of the transportation conform ity rule, 40 CFR 93, Subpart A (73 FR 66183). Additionally, Clark County’s commitment to submit a maintenance plan to EPA that incorporates all emissions from a conformity determination for the force beddown of the F-35 Force Development Evaluation and Weapons School at Nellis Air Force Base is consistent with the general conformity requirements of CAA Section 176(c) and 40 CF R 93.158(a)(5)(i)(B).Ozone Redesignation Request and Maintenance Plan

March 2011 6-1 

### 6.0 MAINTENANCE PLAN

6.1 INTRODUCTION

The fifth required component of an area’s rede signation request is fulf illment of CAA Section 107(d)(3)(E) requirements. These specify that for an area to be redesigna ted to attainment, EPA must approve a maintenance plan that meets al l the conditions of CAA Section 175(a), including a comprehensive and accurate demonstration of continued maintenance of the ozone NAAQS for ten years after redesignation.

Two approaches are acceptable for demonstra ting maintenance of the NAAQS (Calcagni, 1992). The first, the emissions projecti ons approach, compares a projected EI with an attainment EI. The second is a complex analysis using gridde d dispersion modeling. Clark County used the emissions projection approach, comparing an EI fo r the attainment year ( 2008) to an EI for the maintenance year (2022). The maintenance year was chosen to allow EPA 18 months after receipt of a complete su bmittal to process Clark C ounty’s redesignation request.

The attainment EI represents an emission level that would not cause a NAAQS violation. If the projected maintenance year EI remains at orbelow the attainment year EI, continued maintenance is demonstrated. In addition, the ma intenance demonstration includes a comparison between an interim year EI (2015) and the attainment year EI to show definitive maintenance throughout the 10-year period after redesignation, not just in the maintenance year.

6.2 TRANSPORATION INPUT DATA

Table 6-1 summarizes the transpor tation data (daily VMT) used to develop the EIs in Section
6.4. The information was obtained from the Regional Transportation Plan 2009-2030 , approved in November 2008 (RTC 2008). All other input data used in developing the EIs, such as vehicle fleet mix, seasonal/day-of-the-week adjustment f actors, and hourly activit y profiles, has also been updated with the most current data available.

Table 6-1. Demographic Data Used to Develop Emission Inventories

Yea r V ehicle Miles Traveled

2008 - attainment 45,259,209

2015 - interim 56,903,109

2022 - maintenance 73,731,008

6.3 EFFICIENCY AND EFFECTIVENESS FACTORS

Control efficiency, rule effectiveness and rule pe netration factors were applied to the attainment emissions of point and nonpoint source categor ies affected by Clark County AQRs, when applicable. The term control efficiency includ es capture efficiency for point sources which defines the percentage of emissi ons from a source that is capture d by a control device. Rule effectiveness reflects the actual capability of a regulatory program to achieve the emission reductions required by regulation. Rule pe netration, on the other hand, are the assumedOzone Redesignation Request and Maintenance Plan

March 2011 6-2 percentage of emissions of th e targeted Source Classificati on Code (SCC) subject to the requirements of a rule.

6.4 EMISSION INVENTORY TYPE CATEGORIES

The inventories for NO

x and VOC emissions for the Clark County nonattainment area was derived from estimates developed for nine EI type categories: poi nt sources, nonp oint sources, private and commercial aviation, Federal aviation, railway, on -road mobile, nonroad mobile, biogenic, and banked emission reduction credits . The following sections provide a brief discussion of each category and its estimated em issions; more detailed explanations of EI estimates can be found in Appendix A, the Clark County Ozone Redesignation Request and Maintenance Plan Technical Support Document (TSD).

6.4.1 Point Sources

Point source inventories include all Title V major stationary sources, minor stationary sources that emit at least 10 tpy of VOCs or 25 tpy of NO

x per year

, and clustered minor stationary
sources that could be consider ed emission hot spots. The sour ce emissions are tabulated from data collected by direct on-site measurements or calculated using emission factors and activities data. When a single facility has multiple sources, emission data is collected for each source and entered into a database that organizes it and a llocates the emissions to a geographic location. To calculate projected EIs, point sources are adjusted by growth f actors based on Source Classification Codes using vers ion 5.0 of EPA’s Economic Growth Analysis System program.

6.4.2 Nonpoint Sources

Nonpoint sources of emissions are those that fall below point source reporting levels and are too numerous or small to identify individually. Ge nerally, they are small-scale industrial or residential operations that use emission-generating materials or processes. Nonpoint sources are generally divided into two groups, according to the emission mechanism: (1) hydrocarbon evaporative emissions, considered primarily as VOCs, or (2) fuel combustion emissions, considered primarily as NO

x . Hydrocarbon evaporative emi ssion sources include printing presses, industrial coatings, degreasing solven ts, house paints, and the filling of underground gasoline tanks. Fuel combustion emission sources include stationary source fossil fuel combustion at residences and businesses, ve hicle/equipment operations, materials burning outdoors, and structural fires.

Nonpoint source emission calculations are estimated as county-wide totals rather than as individual source emissions. With some excep tions, these emissions may be calculated by multiplying an EPA-approved factor (emissions pe r unit of activity) by the appropriate activity or activity surrogate responsible for generating emi ssions. When available, ac tual activity data is used; when unavailable, surrogates are used, including county population or employment data by industry type (and, when applicable, by growth f actors from EPA’s Economic Growth Analysis System model).Ozone Redesignation Request and Maintenance Plan

March 2011 6-3 6.4.3 Private and Commercial Aviation

Private and commercial aviation in Clark County is ove rseen by the Clark County Department of Aviation and served by five airports: (1) McCa rran International Airport; (2) North Las Vegas Airport; (3) Henderson Executive Ai rport; (4) Jean Airport; and (5 ) Perkins Field Airport. The Aviation Department provided Clark County with the 2008 actual and 2022 estimated EIs for each of these five facilities, along with emission estimates for the proposed Ivanpah Airport and Sloan Heliport (Ricondo and Associates Inc. 2008) in the southern part of the county. Emission estimates for 2015 were interpolated using the 2008 and 2022 EIs, minus the estimates for Ivanpah and Sloan. The Ivanpah Airport will not be completed until 2020, and the Sloan Heliport will not be operational until 2017.

6.4.4 Federal Aviation

Federal aviation in Clark County centers around Nellis Air Force Ba se, a major aircraft training facility seven miles northeast of Las Vegas. Although most emi ssions at Nellis come from aircraft operations, the base holds a Title V permit to cover stationary source emissions that also permeate the area. Both emission types were included in the overall EIs Nellis provided to Clark County for 2008 and 2022.

The 2022 EI included emissions from the beddown of F-35 aircraft, which will be used to train instructor pilots and support the Air Force W eapons School’s mission of testing and evaluation. Emission estimates for 2015 were interpolated us ing the 2008 and 2022 EIs, minus the emissions
from the F-35 beddown. Once the 2015 EI was cal culated, F-35 beddown emissions were added back in because Nellis expects the wing to be fully operational between 2012 and 2013.

6.4.5 Railway

The sole proprietor of railroad track in Clark County is Union Pacific Railroad; in 2008, it operated roughly 148 miles of track in the county and consumed about 3.9 million gallons of diesel while hauling approximately 3.2 billion gross tons. Emissions from locomotives are assumed to be uniform throughout the year, and ar e based on activity throughput data in the form of gross tonnage hauled and emission factors.

To project activity throughput, Clark County incor porated an average annua l growth rate of one and a half percent into the 2008 EI, based on average domestic freight demand forecasts from the Federal Highway Administrati on. EIs for 2015 and 2022 included future emissions associated with proposed high-speed passenger train service between Las Vegas and southern California, for which Clark County obtained estimates from the draft environmental impact statement (Federal Railroad Administration 2008).

6.4.6 On-Road Mobile

On-road mobile sources consist of cars, trucks, motorcycles, and other mo tor vehicles traveling on public roadways. Combustion-related emissions (NO

x and CO) were estimated for vehicle engine exhaust; evaporative hydro carbon emissions (VOCs) were estimated for the fuel tank andOzone Redesignation Request and Maintenance Plan

March 2011 6-4 other evaporative leak sources on the vehicle. Clark County then developed emission factors for 2008, 2015, and 2022 using the CONCEPT MV model; the MOBILE6 emissions factor model; Vehicle Miles Travelled (VMT) from the RT C’s transportation demand model (TDM); and federal Highway Performance Monitoring System (HPMS) data from the Nevada Department of Transportation (NDOT). Every effo rt was made to use parameters reflective of local conditions. Local parameters include vehicle speeds by road way type, vehicle regist ration by vehicle type and age, percentage of vehicles in cold-start mo de, percentage of miles traveled by vehicle type, type of I/M program in place, and gasoline vapor pressure.

6.4.7 Nonroad Mobile

Nonroad mobile sources consist of a wide vari ety of equipment types that either move under their own power or can be moved from site to si te, with the exception of locomotive, aircraft, and airport ground support equipment. Nonroad EI s for 2008, 2015, and 2022, which were estimated using the EPA’s NONROAD model, included more than 80 ba sic and 260 specific types of nonroad equipment. The model further stratifie d equipment types into ten categories by horsepower rating and fuel type, th en incorporated the effects of recent federal regulatory actions (i.e., emission standards for nonroad compression i gnition engines and ultra- low sulfur diesel). The model also accounted for fleet turnover, wh en older engines are replaced by newer engines that comply with stricter federal emission controls.

6.4.8 Biogenic

Biogenic sources include agricu ltural crops; lawn grass; fo rests that produce isoprene, monoterpene, alpha-pinene, and other VOC emissi ons; and soils that generate trace amounts of

NO

x . Like emissions from man-made sources (a nthropogenic emissions), biogenic emissions react with oxidants in the atmosphere to produc e ozone; they can even dominate anthropogenic emissions in some areas. A comparison of biogeni c emissions estimates to emissions estimates for other categories (e.g., mobile sources) show ed that biogenic emissions represent a large portion of overall VOC emissi ons in Clark County. Clark County assumed these emissions would remain constant over time because bioge nic emissions are beyond the scope of reasonable
emission reduction measures. The EIs for 200 8, 2015, and 2022 were based on the Model of
Emissions of Gasses and Aerosols from Nature (MEGAN) estimates, measured emission factors, and species information from completed surveys.

6.4.9 Banked Emission Reduction Credits

Under strict guidelines, Emissi on Reduction Credits (ERCs) may be granted, if requested, to a source that voluntarily reduces em issions beyond required levels of control. ERCs may be sold, leased, banked for future use, or traded in accordance with applicable regulations. Both NDEP and Clark County have authority to bank ERCs in Clark C ounty. NDEP has jurisdiction over permitting, compliance, and ERC banking for plants that burn fossil fuels in a boiler to produce steam for the production of electricity (NRS 445B.500) in Clark County; all other emission units in Clark County are under the ju risdiction of Clark County. While developing this plan, Clark County verified NDEP’s bank of VOCs and NO

x and the two facilities from which the relatedOzone Redesignation Request and Maintenance Plan

March 2011 6-5 ERCs originated. At this time, neither Clark County nor NDEP has any pending ERC applications.

Clark County chose to account for all ERCs in the maintenance year 2022 because ERCs can be
used in nonattainment areas to offset emissions of new major sources and major modifications at existing major sources. Therefore, ERC emissions are already accounted for in the point source emissions growth estimated fo r 2022, i.e., point source emissions growth and ERCs largely overlap. To be conservative, how ever, Clark County is not consid ering the potential overlap of these emissions in this plan.

6.5 SUMMARY OF EMISSION INVENTORIES

Table 6-2 summarizes the 2008, 2015, a nd 2022 VOC EIs for nine source type categories in tons per day (tpd). Figures 6-1 through 6-3 s how the VOC EIs for 5 source categories 1 for each of those three years. Detailed information on the me thodologies used to estimate EIs can be found in the TSD (Appendix A).

Table 6-2. Summary of Total Daily VOC Emissions (tpd)

Source Category 2008 VOC 2015 VOC 2022 VOC

Point source 1.32 1.61 1.74
Nonpoint source 57.07 66.21 76.15

Commercial Aviation 2.6 2.83 4.14

Federal Aviation 0.79 0.9 0.95

On-road mobile 65.08 45.32 36.71

Nonroad mobile 42.91 32.29 29.73
Biogenic 132 132 132

ERC 0 0.43 0.43

Total 301.77 281.59 281.85

1 Airports are considered point sources; therefore, the commercia l and federal aviation emissions are accounted for in the Point Source category. Only five source categories are shown in the graphs.

.Ozone Redesignation Request and Maintenance Plan

March 2011 6-6 Point source 1% Nonpoint source 19% Mobile

36%

Biogenic

44%

ERC

0% 

### 2008 VOC

Figure 6-1. VOC Emission Inventory for 2008

Point source 2% Nonpoint source 23% Mobile

28%

Biogenic

47%

ERC

0% 

### 2015 VOC

Figure 6-2. VOC Emission Inventory for 2015Ozone Redesignation Request and Maintenance Plan

March 2011 6-7 Point source 2% Nonpoint source 27% Mobile

24%

Biogenic

47%

ERC

0% 

### 2022 VOC

Figure 6-3. VOC Emission Inventory for 2022

Table 6-3 summarizes the 2008, 2015, and 2022 NO

x EIs for all nine sour ce type categories. Figures 6-4 through 6-6 show the NO

x EIs for 5 source categories 2 for each of those three years. Detailed information on the methodologies used to estimate EIs can be found in the TSD (Appendix A).

Table 6-3. Summary of Total Daily NO
x Emissions (tpd)

Source Category 2008 NOx 2015 Nox 2022 Nox

Point source 28.73 31.54 31.73
Nonpoint source 5.41 5.64 5.9

Commercial Aviation 11.41 14.78 28.82

Federal Aviation 1.27 1.87 2.26

On-road mobile 68.46 34.69 23.15

Nonroad mobile 43.28 30.1 19.51
Biogenic 5 5 5

ERC 0 22.23 22.23

Total 163.56 145.85 138.6

2 Airports are considered point sources; therefore, commercial and federal aviation emissions ar e accounted for in the Point Source category. Only five source categories are shown in the graphs.Ozone Redesignation Request and Maintenance Plan

March 2011 6-8 Point source
25%

Nonpoint source
3%

Mobile

69% Biogenic

3% ERC

0% 

### 2008 NOx

Figure 6-4. NO
x Emission Inventory for 2008

Point source
33%

Nonpoint source
4%

Mobile

44% Biogenic

4% ERC

15% 

### 2015 NOx

Figure 6-5. NO
x Emission Inventory for 2015Ozone Redesignation Request and Maintenance Plan

March 2011 6-9 Point source
45%

Nonpoint source
4% Mobile

31% Biogenic

4% ERC

16% 

### 2022 NOx

Figure 6-6. NO
x Emission Inventory for 2022

In summary, total VOC emissions decrease by 19.9 percent between 2008 and 2022 with the
maintenance control measures described in Section 4.4, or from 301.77 tpd to 281.85 tpd. Total

NO

x emissions follow a similar downtrend, decr easing 24.9 percent between 2008 and 2022, or from 163.5 tpd to 138.6 tpd.

6.6 MAINTENANCE DEMONSTRATION

CAA Section 175(a) requires each request for rede signation to be accompanied by a SIP revision that provides for maintenance of the NAAQS for at least ten years after redesignation. Following EPA guidance (Calcagni, 1992), Clark County dem onstrated maintenance of the ozone NAAQS by comparing projected 2015 and 20 22 EIs with the attainment ye ar EI (2008). If the 2015 and 2022 EIs are less than the 2008 EI, then mainte nance of the NAAQS is demonstrated. As illustrated in Tables 6-2 and 6-3, projected future year VOC and NO

x emissions in the Clark County nonattainment area are less than 2008 emissions . Figure 6-7 illustrate s the differences in the attainment, interim, and maintenance year EIs for VOC and NO

x .Ozone Redesignation Request and Maintenance Plan

March 2011 6-10 Figure 6-7. Comparison of 2008, 2015, and 2022 NO
x Emissions 0 20 40 60 80 100 120 140 160 180

2008 NOx 2015 NOx 2022 NOx 

### NOx Emissions ( tpd )

Point source Nonpoint source Mobile Biogenic ERC ` Attainment = 163.5 tpdOzone Redesignation Request and Maintenance Plan

March 2011 6-11 Figure 6-8. Comparison of 200 8, 2015, and 2022 VOC Emissions

The EIs show a downward trend in both VOC and NO

x emissions, due mainly to the control
measures described in Section 4.4. No increase s in emissions are expect ed in the intervening years that will threaten the demonstration of at tainment because this downward trend, and the fact that future EIs in the maintenance y ear are considerably below the 2008 levels.

6.7 MONITORING NETWORK AND VE RIFICATION OF CONTINUED
ATTAINMENT

After EPA redesignates the Clark County nonattainme nt area to attainment status, Clark County will continue to operate the air qua lity monitoring network to verify the continued attainment of the 1977 8-hour ozone NAAQS. Annua l review of the SLAMS air quality surveillance system will be conducted in accordance with 40 CFR 58.20(d) to determine whether the system
continues to meet monitoring objectives.

6.8 CONTINGENCY PLAN

CAA Section 175A(d) requires that a maintenance pl an contain contingency provisions to assure prompt correction of any violation of the 8- hour ozone NAAQS. Contingency plans must also
describe the methods that will be used to ensure the measures in the plan are adopted expeditiously once the need is triggered. While EPA guidance states that a contingency plan does

not have to contain fully adopted contingency meas ures (Calcagni, 1992), it should at least have three primary elements: 0 50 100 150 200 250 300 350

2008 VOC 2015 VOC 2022 VOC 

### VOC Emissions (tpd)

Point source Nonpoint source Mobile Biogenic ERC ` Attainment = 301.8 tpdOzone Redesignation Request and Maintenance Plan

March 2011 6-12 1. A list of potential contingency measures.

2. An explanation of the tracking and triggeri ng mechanisms that will determine when contingency measures are needed.

3. A description of the process for recommendi ng and implementing contingency measures, with specific timelines for action.

6.8.1 Potential Contingency Measures

In addition to the six potential contingency measures outlined below, Clark County may evaluate other strategies to address any future ozone NAAQS violations in th e most appropriate and effective manner possible.

6.8.1.1 Reid Vapor Pressure Reduction

In conjunction with the Nevada Department of Agriculture, Clark County may consider requiring the reduction of gasoline Reid vapor pressure to below 9.0 psi within the nonattainment area during the summer ozone season.

6.8.1.2 Inspection/Maintenance Program Changes and Additions

In conjunction with the Nevada Department of Transportation, Clark County may consider changing the cutpoints for VOCs and NO

x applicable to pre-1996 vehi cles and/or increase the I/M waiver repair ra te in Clark County.

6.8.1.3 Consumer and Commercial Products

Clark County may consider regulations to restrict the sale, offer for sale, or manufacture for sale of any consumer product, such as personal care products, automo tive and industrial maintenance products, and pesticides that cont ain VOCs above specified limits.

6.8.1.4 Architectural Surface Coatings

Clark County may consider regulati ons to restrict the sale, supply, offer for sale, or solicitation of the application of architect ural coatings that contai n VOCs above specified limits.

6.8.1.5 Lawn and Garden Equipment Use

Clark County may consider regulations to restrict the use of gasoline-powered lawn mowers on announced ozone action days in the Clark County nonattainment area.

6.8.1.6 Establish/Enhance Trip Reduction Programs

In conjunction with the RTC, Clark County may establish and/or enhance employer-based community outreach and marketing efforts, employer rideshare program incentives, preferential parking for carpoolers and vanpoolers, emergency rides home for Club Ride members, travelOzone Redesignation Request and Maintenance Plan

March 2011 6-13 assistance information on the Internet and at publi c kiosks, transit passes to subsidize employees’ transit expenses, and partnerships with vanpool leasing companies.

6.8.2 Tracking and Triggering Mechanisms

The primary tracking mechanism will be Clar k County’s continuous ozone monitoring, as
described in Section 6.7. Clark C ounty will examine ambient air qua lity monitoring data within 30 days of collection to determine if the oz one NAAQS has been exceeded. The RTCs ongoing regional transportation planning pr ocess will serve as another means of tracking mobile source
VOC and NO

x precursor emissions. RTC revises its tran sportation improvement plan every three years, and these revisions are subject to a trans portation conformity finding; that process will serve as a periodic check on maintaining the VM T and mobile source emissions projections of this plan.

The primary trigger mechanism will be a conf irmed violation of th e 1997 8-hour ozone NAAQS, or a three-year average of the fourth highest va lues that is equal to or greater than 0.085 ppm. The trigger date will be 60 days from the date Clark County observes a fourth highest value that, would result in a design value equa l to or greater than 0.085 ppm.

The triggering of the contingency plan does not automatically require a revision of the Clark County ozone SIP, nor would Clark County necessarily be redesignated to nonattainment. Instead, Clark County will have a period of time to correct the violation by implementing one or more contingency measures. If ozone violations continue after contingency measures have been implemented, additional measures will be implemented until the violations are corrected.

6.8.3 Action Resulting from Trigger Activation

Within 45 days of the trigger da te, Clark County will notify EPA that an internal review process will begin to evaluate potential contingency meas ures. Within 90 days of that notification, Clark County will send EPA an information report ou tlining recommended acti ons. Clark County will
then solicit stakeholder involveme nt through public forums (i.e., oz one working groups) to refine the process of implementing the recommende d actions. The BCC, Nevada State Board of Agriculture, and/or Nevada State Environmen tal Commission will hold a public hearing(s) to consider the recommended contingency measures , along with any other contingency measures that may address the confirmed violation. The n ecessary contingency measures will be adopted and implemented within 18 mont hs after submittal of the information report to EPA.

6.9 SUBSEQUENT MAINTENANCE PLAN REVISIONS

Section 175A(b) requires that eight years afte r redesignation of any ar ea to attainment under Section 107(d), the state shall submit an additional revision of the applicable SIP that shows how the NAAQS will be maintained for 10 years after th e expiration of the first 10-year period. Clark County commits to the submittal of a revised main tenance plan eight years after Clark County is redesignated to attainment.Ozone Redesignation Request and Maintenance Plan

March 2011 7-1 

### 7.0 MOTOR VEHICLE EMISSIONS BUDGETS

Under CAA Section 176(c), transportation plans, programs, and projects in maintenance areas that are funded or approved under Title 23 of the U.S. Code or the Federal Transit Act must conform to the on-road MVEBs sp ecified in the applicable SI P. In this case, 40 CFR 93.118 provides the criteria and procedures for MVEBs.

The MVEB establishes a cap on motor vehicle-re lated emissions that cannot be exceeded by predicted transportation system emissions. The emissions budget applies as a ceiling on emissions in the year for which it is defined, an d for all subsequent year s until a different budget is defined for another year or a SIP revision modifies the budget. Unless the SIP clearly indicates otherwise, the estimate of future transportati on network emissions used in the milestone or
attainment demonstration acts as the MVEB.

Table 7-1 provides 201 5 and 2022 VOC and NO

x MVEBs for the area of Clark County that comprises the 1997 8-hour ozone maintenance ar ea. Upon an EPA affirmative adequacy finding and approval of the MVEBs, these budgets will be used for confor mity determinations in future regional transportation plans.

Table 7-1. VOC and NO
x MVEBs for Clark County

Yea r V OC MVEBs (tpd) NO x MVEBs (tpd)

2008 – attainment 65.08 68.46

2015 – interim 45.32 34.69

2022 – maintenance 36.71 23.15Ozone Redesignation Request and Maintenance Plan

March 2011 8-1 

### 8.0 REFERENCES

43 FR (Federal Register) 8962.” National Ambien t Air Quality Standards: State Attainment

Status.”

44 FR 8220. Revision of primary a nd secondary ozone standards.

51 FR 41788. “Designations of Areas for Air Qual ity Planning Purposes; Las Vegas Valley, NV, Redesignation for Ozone.”

62 FR 38856. “National Ambient Air Qualit y Standards for Ozone; Final Rule.”

65 FR 6822. “Control of Air Pollution From New Motor Vehicles: Tier 2 Motor Vehicle
Emissions Standards and Gasoline Sulfur C ontrol Requirements; Final Rule. Part 80— Regulation of Fuels and Fuel Additives.”

65 FR 76789. “Control of Emissions from New Nonroad Spark-Ignition Engines Rated Above
19 Kilowatts and New Land-Based Recr eational Spark-Ignition Engines.”

69 FR 23858. “8-Hour Ozone National Ambient Air Qu ality Standards; Fina l Rules. Air Quality Designations and Classifications for the 8-Hour Ozone National Ambient Ai r Quality Standards; Early Action Compact Areas w ith Deferred Effective Dates.”

69 FR 34076. “Air Quality Designations and Cl assifications for the 8-Hour Ozone National Ambient Air Quality Standards; Deferral of Effective Date.”

69 FR 38958. “Control of Emissions of Air Pollu tion from Nonroad Diesel Engines and Fuel;
Final Rule.”

70 FR 20665. “Clean Air Fine Pa rticle Implementation Rule.”

70 FR 71612. “Final Rule To Implement the 8-Hour Ozone National Ambient Air Quality Standard-Phase 2; Final Rule To Implement Certain Aspects of the 1990 Amendments Relating to New Source Review and Prevention of Signi ficant Deterioration as They Apply in Carbon Monoxide, Particulate Matter and Ozone NAAQS; Final Rule for Reformulated Gasoline.”

73 FR 59034. “Control of Emissions from Nonr oad Spark-Ignition Engines and Equipment;
Final Rule.”

73 FR 66182. “Approval and Promulgation of Implem entation Plans; Revisions to the Nevada State Implementation Plan; Clark County.”

74 FR 22738. “Adequacy Status of Motor Vehi cle Emissions Budgets in Submitted Early Progress Plan for Clark County 8-hour Ozone for Transportation Conformity Purposes; Nevada.”Ozone Redesignation Request and Maintenance Plan

March 2011 8-2 75 FR 6571. “Approval and Promulgation of Air Quality Implementation Plans; Louisiana; Baton Rouge 1-Hour Ozone Nonattainment Area; Determination of Attain ment of the 1-Hour
Ozone Standard.”

Calcagni, J. 1992. “Procedures for Processing Reque sts to Redesignate Areas to Attainment.” Memorandum from John Calcagni, Air Quality Ma nagement Division Dir ector, to EPA Regional Division Directors, dated 9/4/1992.

Center for Business and Economic Research. 201 0. “Historical Economic Data for Metropolitan Las Vegas.” Las Vegas, Nevada: Un iversity of Nevada, Las Vegas. http://cber.unlv.edu/snoutlk.html.

DAQEM (Clark County Department of Air Qua lity and Environmental Management). 2008a. Eight Hour Early Progress Plan for Clark County . Las Vegas, Nevada: Clark County Department of Air Quality and Environmental Management.

DAQEM. 2008b. Quality Control and Assurance Syst em for Criteria Gaseous Pollutant. Las Vegas, Nevada: Clark County Department of Air Quality and Environmental Management.

DAQEM. 2008c. Clark County Transportation Conformity Plan . Las Vegas, Nevada: Clark County Department of Air Quality and Environmental Management.

DAQEM. 2010a. Clark County Air Quality Regulation, Section 12. Preconstruction Review for New or Modified Stationary Sources . Las Vegas, Nevada: Clark County Department of Air Quality and Environmental Management.

DAQEM. 2010b. Clark County Air Qu ality Regulation, Section 52. Gasoline Dispensing
Facilities . Las Vegas, Nevada: Clark County Depart ment of Air Quality and Environmental Management.

Desert Research Institute. 2006. Biogenic Volatile Organic Compound Emission Inventory Improvement Project . Prepared for the Clark County Department of Air Quality and Environmental Management.

Environ, Inc. 2007. Clark County Consolidated Emissions Inventory Report. Prepared for Clark County Department of Air Quality and Environmental Management.

Environmental Quality Management, Inc. 2006. Biogenic Emission Inventory for Clark County,
Nevada . Prepared for Clark County Department of Air Quality and Environmental Management.

Ricondo & Associates, Inc. 2008. Emission Inventories Clark Count y Airport System Airports. Prepared for Clark County Department of Air Quality and Environmental Management.

RTC (Regional Transportation Comm ission of Southern Nevada). 1999. Transportation Improvement Plan 1998-2000 . Las Vegas, Nevada: Regional Transportation Commission of
Southern Nevada.Ozone Redesignation Request and Maintenance Plan

March 2011 8-3 RTC. 2008. Regional Transportation Plan 2006-2030 . Las Vegas, Nevada: Regional Transportation Commission of Southern Nevada.

Western Regional Climate Center. 2010. “Western Regional Climate Center / Historical Climate Information.” Las Vegas, Nevada: Desert Research Institute.
www.wrcc.dri.edu/CLIMATEDATA.html.