Second 10-Year Maintenance Plan for the 

Truckee Meadows 8-Hour Carbon Monoxide 

Attainment Area 

August 28, 2014

Washoe County Health District 

Air Quality Management Division 

P.O. Box 11130 

Reno, Nevada 89520-0027 

(775) 784-7200 

www.OurCleanAir.com
i 

TABLE OF CONTENTS

 Page

Acknowledgements .................................................................................................................. iv 

Chapter 1: Introduction ..............................................................................................................1 

Chapter 2: Maintenance Plan .....................................................................................................3 

Attainment Inventory .....................................................................................................3 

 Point Sources .....................................................................................................4 

 Nonpoint Sources ...............................................................................................4 

 Non-Road Mobile Sources .................................................................................4 

 On-Road Mobile Sources ...................................................................................4 

Maintenance Demonstration ..........................................................................................4 

 Truckee Meadows Maintenance Emissions Limit .............................................5 

 Maintenance of the NAAQS ..............................................................................6 

1. Baseline Emission Projections ..............................................................6 

2. EPA Models ..........................................................................................6 

3. Emission Category Surveys ..................................................................7 

 Summary ............................................................................................................7 

 Motor Vehicle Emissions Budget ..................................................................................7 

 Monitoring Network ......................................................................................................8 

 Verification of Continued Attainment ...........................................................................9 

1. Periodic Emissions Inventories ....................................................................9 

2. Consolidated Emissions Reporting Rule (CERR) and

Air Emissions Reporting Rule (AERR) .......................................................9 

3. Residential Wood Use Survey ...................................................................10 

 Contingency Plan .........................................................................................................10 

 Contingency Plan - Tier 1 ................................................................................11 

 Trigger Mechanism - Tier 1 .......................................................................11 

 Contingency Measure - Tier 1 ...................................................................11 

 Implementation Schedule - Tier 1 ..............................................................11 

 Contingency Plan - Tier 2 ................................................................................11 

 Trigger Mechanism - Tier 2 .......................................................................11 

 Contingency Measure - Tier 2 ...................................................................11 

 Implementation Schedule - Tier 2 ..............................................................12 

List of Tables ............................................................................................................................ ii 

List of Figures ........................................................................................................................... ii

Appendices ................................................................................................................................ ii

Acronyms ................................................................................................................................. iii
ii

LIST OF TABLES

Table Page

 1-1 2008-2013 Truckee Meadows 8-hour CO Concentrations (ppm) ...........................2 

 2-1 2011 CO Attainment Inventory (lbs/day) ................................................................3 

 2-2 Historic Truckee Meadows CO Wildfire Emission Inventories (lbs/day) ...............5 

 2-3 Truckee Meadows CO Emission Inventories (lbs/day) ...........................................6 

 2-4 Truckee Meadows CO Maintenance Emission Inventories (lbs/day) ......................7 

 2-5 Truckee Meadows CO Safety Margin (lbs/day) ......................................................8 

 2-6 Truckee Meadows CO MVEB (lbs/day)..................................................................8 

 2-7 Active Washoe County CO Monitoring Sites ..........................................................9 

 2-8 Potential CO Contingency Measures .....................................................................11 

LIST OF FIGURES

Figure Page

 1-1 Washoe County, Nevada ..........................................................................................1 

 2-1 South Reno Monitoring Site ....................................................................................9 

APPENDICES

 Appendix 

A. Growth Factors for 2015, 2020, 2025, and 2030 Projections 

B. Truckee Meadows Projected CO Seasonal Emissions 
iii

ACRONYMS

AERR Air Emissions Reporting Requirements

AQMD Washoe County Health District - Air Quality Management Division

AQS Air Quality System

CO Carbon Monoxide 

CAA Clean Air Act

CERR Consolidated Emissions Reporting Rule 

CFR Code of Federal Regulations

EI Emissions Inventory

EPA United States Environmental Protection Agency 

FR Federal Register

HA Hydrographic Area

MA Maintenance Area

MPO Metropolitan Planning Organization 

MVEB Motor Vehicle Emissions Budget 

NAA Non-Attainment Area

NAAQS National Ambient Air Quality Standard

NCore National Core Multi-Pollutant Monitoring Station

RTC Regional Transportation Commission 

RWC Residential Wood Combustion 

SIP State Implementation Plan

SLAMS State and Local Air Monitoring Station

SPM Special Purpose Monitoring 

VMT Vehicle Miles Traveled

WCDBOH Washoe County District Board of Health 
iv 

ACKNOWLEDGEMENTS 

Washoe County District Board of Health 

Matt Smith, Chair 

Kitty Jung, Vice Chair 

George Hess, MD 

Denis Humphreys, OD 

Julia Ratti 

David Silverman 

Neoma Jardon 

Washoe County Health District 

Kevin Dick, District Health Officer 

Washoe County Health District, Air Quality Management Division 

Charlene Albee, Director 

Daniel Inouye, Branch Chief 

Yann Ling-Barnes, P.E., Environmental Engineer II, Project leader 

Julie D. Hunter, Senior Air Quality Specialist 

Brendan Schnieder, Air Quality Specialist II 
CO Maintenance Plan August 28, 2014 

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CHAPTER 1

INTRODUCTION

The Truckee Meadows1 has attained the 8-hour Carbon Monoxide (CO) National Ambient Air 

Quality Standards (NAAQS) since 1991. A Redesignation Request and Maintenance Plan for 

the Truckee Meadows Carbon Monoxide Non-Attainment Area (NAA) was submitted to the 

Environmental Protection Agency (EPA) in September 2005, and the Truckee Meadows was 

redesignated to attainment status effective August 4, 2008.2 This State Implementation Plan 

(SIP) revision is to address the completion of the second 10-year CO maintenance plan

demonstrating continued attainment through 2030. 

Washoe County is located in the northwest portion of Nevada 

and is bounded by the states of California, Oregon, and the 

counties of Humboldt, Pershing, Storey, Churchill, Lyon, and 

Carson City (Figure 1-1). The Truckee Meadows is 

approximately 200 square miles in size and situated in the 

southern portion of Washoe County. It is geographically 

identified as Hydrographic Area (HA) 87 as defined by the 

State of Nevada, Division of Water Resources. It is 

surrounded by mountain ranges, which can lead to wintertime 

temperature inversions, where a layer of cold air is trapped in 

the valley. Warmer air above the inversion acts as a lid, 

containing and concentrating air pollutants. Much of Washoe 

County’s urban population lives in the Truckee Meadows. 

Anthropogenic activities, such as automobile use and 

residential wood combustion (RWC), are also concentrated 

here.

The Truckee Meadows covers an area governed by three political entities - the County of 

Washoe, the City of Reno, and the City of Sparks. The AQMD is the designated agency 

responsible for air quality management throughout the entire county. 

There have been no exceedances or violations of the 8-hour CO standard since 1991. The 

AQMD Redesignation Request and Maintenance Plan submitted to the EPA in 2005 

demonstrated attainment and maintenance of the CO standards through 2016. On July 3, 2008, 

EPA published a final rule redesignating the Truckee Meadows to attainment of the CO 

NAAQS.3

 Since 2008, monitored CO concentrations have been consistently more than 65% 

below the NAAQS. Table 1-1 lists the first and second highest 8-hour CO concentrations from 

2008 to 2013. 

 

1 Identified as the “Reno Planning Area” in 40 CFR 81.329.

2 73 FR 38124 (July 3, 2008).

3 73 FR 38124 (July 3, 2008).

Figure 1-1

Washoe County, Nevada 
CO Maintenance Plan August 28, 2014 

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Table 1-1 

2008-2013 Truckee Meadows 8-hour CO Concentrations (ppm) 

Year 2008 2009 2010 2011 2012 2013

1st High 2.9 2.9 2.8 3.3 2.4 2.6

2nd High 2.9 2.6 2.6 2.9 2.3 2.4

This Maintenance Plan was prepared in accordance with Section 175A of the Clean Air Act 

(CAA). It is being submitted four years prior to the expiration of the first ten year period in 

order to coordinate milestone years of the PM10 Motor Vehicle Emission Budget (MVEB). A 

PM10 Redesignation Request and Maintenance Plan is expected to be submitted to EPA along 

with this CO Maintenance Plan. This plan demonstrates continued maintenance of the CO 

standard in the Truckee Meadows through 2030 and establishes MVEBs for 2015, 2020, 2025, 

and 2030. 
CO Maintenance Plan August 28, 2014 

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CHAPTER 2 

MAINTENANCE PLAN

In accordance with Section 175A of the CAA, the AQMD has prepared and is submitting this

second 10-year maintenance plan. The purpose of this SIP revision is to provide for maintenance 

of the 8-hour CO NAAQS for an additional ten years following the first 10-year period. This 

maintenance plan meets Section 107(d)(3)(E) requirements by including the following core 

provisions to ensure continued maintenance of the 8-hour CO NAAQS. 

• Attainment Inventory;

• Maintenance Demonstration;

• Motor Vehicle Emissions Budget;

• Monitoring Network; 

• Verification of Continued Attainment; and 

• Contingency Plan. 

Attainment Inventory

The AQMD developed a 1990 baseline emissions inventory as part of the “Moderate” CO NAA

State Implementation Plan (SIP). Since 1990, periodic emission inventories have been compiled 

on a triennial schedule with the most recent inventory prepared for 2011. The 2011 emissions 

inventory (Table 2-1)4 is identified as the attainment inventory because it used the best and 

updated methodologies for all sources, and it has the most comprehensive and current emission 

inventory that is sufficient to continue to attain the NAAQS. 

Table 2-1 

2011 CO Attainment Inventory (lbs/day) 

Source Category 2011

Attainment Inventory

Point 3,361

Nonpoint 154,956

Non-road 50,706

On-road 163,500

Total* 372,522

* Totals may not add up due to rounding.

Below is a summary of procedures used to ensure that CO emissions were calculated and 

apportioned accurately for the Truckee Meadows. Complete documentation is included in 

“Washoe County, Nevada 2011 Periodic Emissions Inventory”. 

 

4 Washoe County, Nevada; 2011 Periodic Emissions Inventory; modified to reflect new onroad emissions from new VMT.
CO Maintenance Plan August 28, 2014 

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Point Sources: Latitude/Longitude coordinates are maintained for each point source. 

Geographic Information Systems (GIS) software was used to overlay HA 87 onto all 

point sources to determine if it was to be included in the Truckee Meadows CO emissions 

inventory. 

Nonpoint Sources: Nonpoint sources with an AQMD operating permit are managed in the 

emissions inventory as if it were a point source (see above). Other nonpoint sources are 

grouped by Source Classification Code (SCC) and assigned a surrogate, which is 

spatially representative of that process. Typical surrogates are population, dwelling units, 

employment, and VMT. Surrogates are spatially disaggregated into a variety of 

geographies such as census areas (blocks, block groups, and tracts), Transportation 

Analysis Zones (TAZ), and ZIP codes. GIS is used to determine what portion of each 

surrogate is included in HA 87. This fraction is applied to county-level emissions for 

each SCC emissions to determine Truckee Meadows CO emissions.

Non-Road Mobile Sources: Non-Road Mobile Sources are grouped by SCCs and 

assigned a surrogate which is spatially representative of that process. Surrogate fractions 

are applied to county-level emissions for each SCC emissions to determine Truckee 

Meadows CO emissions. 

On-Road Mobile Sources: The Metropolitan Planning Organization (MPO) manages the 

regional transportation demand model. The model includes planning assumptions, such 

as population and VMT, for each TAZ in the county. GIS software was used to overlay 

HA 87 onto all TAZs to determine if it was to be included in the Truckee Meadows CO

emissions inventory. Data from TAZs within HA 87 were combined and incorporated 

into the MOVES model to calculate on-road mobile source CO emissions. 

Maintenance Demonstration 

Maintaining the CO NAAQS may be demonstrated by showing that future emissions will not 

exceed the level of the attainment inventory. Also, attainment must be demonstrated for the 10-

year period following EPA’s approval action on the redesignation request. In November 2005, 

the NDEP submitted AQMD’s “Redesignation Request and Maintenance Plan for the Truckee 

Meadows Carbon Monoxide Non-Attainment Area” to EPA. EPA approved the Redesignation 

Request and Maintenance Plan in July 2008. This maintenance plan demonstrates attainment for 

the remainder of the first maintenance period (through 2018) as well as the second 10-year 

period (2018-2028). Since a state may go beyond the minimum requirements of the CAA, the 

horizon year of this maintenance plan will be 2030 to eliminate the requirement for the MPO to 

perform additional conformity findings for in-between analysis years. 

Although the first maintenance period is scheduled to end in 2018, the 2015 projected emissions 

calculated in this maintenance plan will replace the 2016 emission projection from the first 

maintenance plan. The rationale for this stems from the availability of better planning 

assumptions and improved emission calculation methodologies, which were not available 10 

years ago. The updated methodologies include the change from using MOBILE6 modeling 
CO Maintenance Plan August 28, 2014 

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software to model on-road emissions 10 years ago, to the MOVES model used in this report. In 

addition, more detailed data are available now that made emission projections and control 

calculations more representative of the region. 

 

Truckee Meadows Maintenance Emissions Limit

The 2011 periodic emissions inventory5 was used as a baseline to develop a maintenance 

emissions limit for the Truckee Meadows. Growth and control factors were applied to 

the emission categories of the 2011 inventory to generate a 2030 Truckee Meadows

maintenance emissions limit. The growth factors were based on demographic, economic, 

VMT, and meteorological data (Appendix A). Control factors were based on planned 

emission reduction strategies.

2011 was an unusually active year for wildfires during the CO season. To approximate a 

more normal wildfire emission during the CO season, an average of the four previous 

inventory years’ (1999, 2002, 2005, and 2008) wildfire emissions were used for planning 

year projections (Table 2-2). The rationale is that wildfire emissions alone should not 

drive future year planning purposes. Future large scale wildfires during CO season will 

be treated as exceptional events and will be submitted to the EPA for exclusion when 

they occur.

Table 2-2 

Historic Truckee Meadows CO Wildfire Emission Inventories (lbs/day)

Inventory Year CO Emissions 

1999 197

2002 412

2005 103

2008 156

2011 105,092

Average (1999-2008) 217

Average (1999-2011) 21,192

Based on these methodologies, the 2011 Truckee Meadows CO emissions limit was established 

at 267,648 lbs/day (Table 2-3).

 

5

Washoe County, Nevada; 2011 Periodic Emissions Inventory and Appendices A, B, C
CO Maintenance Plan August 28, 2014 

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Table 2-3 

Truckee Meadows CO Emission Inventories (lbs/day) 

2011 2011

Source Category Periodic Inventory Maintenance Emission Limit

Point 3,361 3,361

Nonpoint 154,956 50,081

Non-Road Mobile 50,706 50,706

On-Road Mobile 163,500 163,500

Total* 372,522 267,648

* Totals may not add up due to rounding.

The 2011 Truckee Meadows CO maintenance emissions limit will be identified as the attainment 

inventory because it:

• Uses the most accurate emissions inventory methodologies; 

• Is a comprehensive and current emissions inventory; 

• Identifies the level of emissions in the Truckee Meadows sufficient to maintain the 

NAAQS; and 

• Will be the emissions inventory most consistent with the 2030 projected inventory 

required for demonstrating maintenance of the NAAQS.

Maintenance of the NAAQS

The projected 2030 emissions inventory used the 2011 Truckee Meadows emissions 

inventory as its baseline, except for the wildfire category, which is explained in the 

previous section. Each of the emission categories in the 2011 Truckee Meadows 

emissions inventory (Appendix B) was projected to 2030 level using one of the following 

EPA emission methodologies or models.6

1. Baseline Emission Projections: Washoe County’s 2030 population, employment, and 

VMT forecasts (Appendix A) were used as surrogates to project the 2030 emissions. 

These forecasts were consistent with those used by the local MPO. 

2. EPA Models: The non-road and on-road motor vehicle categories accounted for 

approximately 59% of the 2011 Truckee Meadows emissions inventory. To ensure 

consistency throughout the maintenance demonstration period, the same non-road and 

on-road models (NONROAD2008a and MOVES2010b) were used to estimate the 

2030 inventory. 

 The 2030 on-road vehicles category incorporated the latest planning assumptions for 

the transportation network including VMT, vehicle speeds, and vehicle population for 

 

6 “Procedures for Preparing Emissions Projections” (EPA-450/4-91-019).
CO Maintenance Plan August 28, 2014 

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passenger cars and trucks. As with previous periodic emission inventories, these 

planning assumptions were consistent with those used by the MPO for their 

transportation plans. 

3. Emission Category Surveys: Residential wood combustion is a significant source of 

CO emissions. The RWC category is updated on a regular basis via an emission 

category survey. As part of the CO maintenance plan SIP, the AQMD is committed 

to conducting this survey at least once every three years.

7

Table 2-4 lists the 2011 Truckee Meadows Maintenance Emissions Limit and the 

2015, 2020, 2025, and 2030 projected emissions for the four major CO emission 

categories. A more detailed inventory can be found in Appendix B. 

Table 2-4 

Truckee Meadows CO Maintenance Emission Inventories (lbs/day) 

Source Category 2011* 2015 2020 2025 2030

Point 3,361 3,768 4,357 4,974 5,678 

Nonpoint 50,081 47,820 45,236 42,845 40,355

Non-road 50,706 43,725 45,385 48,320 51,656

On-road 163,500 150,330 140,129 138,938 142,686 

Total** 267,648 245,642 235,107 235,077 240,375

* Truckee Meadows Maintenance Emissions Limit.

** Totals may not add up due to rounding.

Summary

Population, households, employment, and VMT are projected to increase through 2030 

and beyond. Federally enforceable CO control programs targeting gasoline-powered 

motor vehicles, RWC, and diesel-powered motor vehicles will help offset this growth. 

Because future emissions are not projected to exceed the level of the 2011 Truckee 

Meadows maintenance emissions inventory, the 8-hour CO NAAQS will be maintained 

through the attainment demonstration period. 

Motor Vehicle Emissions Budget 

Transportation conformity is required by Section 176(c) of the CAA. Under EPA’s 

transportation conformity regulations,8

 transportation plans and improvement programs must be 

consistent with, or conform to, the motor vehicle emissions budget (MVEB) defined in the 

applicable SIP. These budgets specify the level of on-road motor vehicle emissions that are 

 

7 73 FR 38124 (July 3, 2008).

8 40 CFR 93.
CO Maintenance Plan August 28, 2014 

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consistent with attainment and maintenance of air quality standards and should include an 

adequate safety margin.9

Emissions inventory data for the years 2015 through 2030 were used to establish the MVEB. 

The MVEB includes on-road vehicles, heavy duty diesel vehicle (HDDV) idling, and a safety 

margin. The safety margin is the excess emissions between the total projected emissions for a 

specific year and the 2011 maintenance emissions limit (Table 2-5). 

Table 2-5 

Truckee Meadows CO Safety Margin (lbs/day)

Category 2015 2020 2025 2030

2011 Maintenance Emissions Limit 267,648 267,648 267,648 267,648

CO Maintenance Emissions Inventory 245,642 235,107 235,077 240,375

Safety Margin 22,006 32,540 32,571 27,272

The MVEB is set at a level that keeps the intermediate (2020 and 2025) and horizon (2030) year 

Truckee Meadows CO emissions less than the 2011 Truckee Meadows maintenance emissions 

limit. For years beyond 2030, the MVEB will remain at the 2030 level of 169,959 lbs/day (Table 

2-6). Because of significant updates to emission models, emission methodologies, and planning 

assumptions, this MVEB will replace the budgets that EPA approved in 2008.10

Table 2-6 

Truckee Meadows CO MVEB (lbs/day) 

Category 2015 2020 2025 2030 

On-Road Vehicles 149,794 139,529 138,288 141,961

HDDV Diesel Idling 536 600 649 7,250 

Safety Margin 22,006 32,540 32,571 27,272 

Motor Vehicle Emissions Budget 172,336 172,670 171,509 169,959 

Monitoring Network 

The Truckee Meadows is currently a CO maintenance area. The AQMD will continue to operate 

an appropriate CO monitoring network, in accordance with 40 CFR 58, to verify the attainment 

status of the area. In addition, Washoe County’s CO monitoring network will be reviewed 

annually pursuant to 40 CFR 58.10 to ensure the network meets the monitoring objectives 

defined in 40 CFR 58, Appendix D. Funding to meet these objectives has been, and will be, 

 

9 Safety margin means the amount by which the total projected emissions from all sources of a given pollutant are less than the total emissions

that would satisfy the applicable requirement for reasonable further progress, attainment, or maintenance. (40 CFR 93.101)

10 73 FR 38128 (July 3, 2008).
CO Maintenance Plan August 28, 2014 

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primarily obtained from: 1) EPA Section 105 grants, and 2) 

Nevada Department of Motor Vehicles funds. 

Ambient CO monitoring data will continue to be collected and 

quality assured in accordance with 40 CFR 58, recorded in the 

Air Quality System (AQS), and available for public review. 

Table 2-6 lists the CO monitoring sites and Figure 2-1 features 

the South Reno Monitoring station as an example.

Table 2-7 

Active Washoe County CO Monitoring Sites

Site ID Site Name Site Address City

32-031-0016 Reno3 301 “A” State Street Reno

32-031-0020 South Reno 4110 DeLucchi Lane Reno

32-031-0022 Galletti 305 Galletti Way Reno

32-031-0025 Toll 684 “A” SR 341 Reno

32-031-1005 Sparks 750 4th Street Sparks 

32-031-2009 Lemmon Valley 325 W. Patrician Drive Reno

Verification of Continued Attainment 

As described in the previous section, the AQMD will continue to operate and maintain an 

appropriate CO monitoring network. Ambient air monitoring data will be used to verify 

continued attainment and maintenance of the 8-hour CO NAAQS.

Tracking actual emissions can identify potential increases in ambient CO levels. The AQMD 

has three existing mechanisms to track emissions. These mechanisms, listed below, will remain 

in place and be used to screen for significant increases in actual CO emissions.

1. Periodic Emissions Inventories: The AQMD will continue to prepare, and submit to EPA, 

comprehensive periodic CO emissions inventories on a triennial schedule. The last 

periodic emissions inventory was prepared for calendar year 2011. 

2. Consolidated Emissions Reporting Rule (CERR) and Air Emissions Reporting Rule 

(AERR): The CERR and AERR simplify and streamline emissions reporting 

Figure 2-1

South Reno Monitoring Site
CO Maintenance Plan August 28, 2014 

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requirements. It requires regular updates of point and area sources within Washoe 

County. The AQMD will continue to meet the requirements of the CERR and AERR. 

3. Residential Wood Use Survey: Residential wood combustion is a significant CO source 

during the winter season. The AQMD has completed nine residential wood use surveys 

between 1993 and 2013. These surveys estimated the device (fireplaces, woodstoves, 

and pellet stoves) population, amount of wood burned, and CO emissions in Washoe 

County. As part of this maintenance plan,

11 the AQMD is committed to conducting this 

survey at least once every three years.

Furthermore, AQMD’s Enforcement Branch is staffed with five inspectors to ensure compliance 

with local air quality regulations. They inspect for permit conditions, respond to complaints, 

patrol and enforce no-burn days during the burn season, and issue warnings and citations for any 

violations found. 

When no-burn days are issued, the enforcement staff will patrol neighborhoods for visible smoke 

from chimneys. They also respond to complaints from neighbors of the home owners who are 

burning their wood burning devices during a no-burn day. They will order the home owner to 

stop burning immediately and issue the home owner a warning for the first offense. Then they 

will return three to four hours later to ensure that the smoke has ceased to be emitted from the 

chimney. If the smoke continues, the home owner would then be issued a citation. 

Continued ambient air monitoring and emissions tracking will ensure verification of continued 

attainment and maintenance of the 8-hour CO NAAQS.

Contingency Plan 

Section 175A of the CAA requires that a maintenance plan include contingency provisions, as 

necessary, to promptly correct any violation of the CO NAAQS that occurs after redesignation of 

the area. The plan should clearly identify: 

• Specific indicators, or triggers, which will be used to determine when contingency 

measures need to be implemented;

• The contingency measures to be adopted; 

• A schedule and procedure for adoption and implementation; and 

• A specific time limit for action.

The typical CO season in the Truckee Meadows is November, December, and January. This is 

when the highest ambient CO concentrations, and possible exceedances, are most likely to occur. 

The contingency measures in this plan target sources that significantly contribute to the CO 

season emissions inventory. The AQMD will establish a two-tiered contingency plan based on 

ambient air monitoring data.

 

11 73 FR 38124 (July 3, 2008).
CO Maintenance Plan August 28, 2014 

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Contingency Plan - Tier 1

Trigger Mechanism - Tier 1: An exceedance (greater than or equal to 9.5 ppm to adjust for 

rounding) of the 8-hour CO NAAQS verified from any State and Local Air Monitoring Station 

(SLAMS), Special Purpose Monitoring (SPM) or National Core Multi-Pollutant Monitoring 

Station (NCore) site operated within Washoe County. 

Contingency Measure - Tier 1: Begin the rulemaking process to redefine “Carbon Monoxide; 

Stage 1 (Alert) Episode” in Washoe County District Board of Health (WCDBOH) Regulation 

050.001.12 The “Stage 1 (Alert) Episode” level shall be reduced from 9.4 ppm to 9.0 ppm. This 

measure will activate “Stage 1 (Alert) Episode” procedures at pre-exceedance CO levels. These 

procedures will reduce CO emissions by: 

• Terminating open burning;13

• Terminating the use of incinerators subject to AQMD operating permits;14

• Curtailment of unnecessary motor vehicle use through AQMD’s public outreach 

program;15

• Prohibiting burning of solid fuel in any commercial or residential stoves and/or fireplaces 

within the Truckee Meadows;16 and

• Curtailment of all AQMD permitted sources that have the potential to emit 50 tons or 

more of CO per year within the Truckee Meadows.17 

In addition, within 45 days of reaching the first trigger mechanism, the EPA Regional Office will 

be notified that this contingency measure has been implemented. 

Implementation Schedule - Tier 1: Rulemaking process to begin promptly. The rule revision 

shall be adopted by the WCDBOH and implemented before the next CO season (November, 

December, and January). Prompt action and implementation of this contingency measure may 

prevent future exceedances and violations of the CO NAAQS. 

Contingency Plan - Tier 2

Trigger Mechanism - Tier 2: A second non-overlapping exceedance (9.5 ppm or greater) of the 

8-hour CO NAAQS in the same calendar year from any SLAMS, SPM, or NCore site operated 

within Washoe County. A second non-overlapping exceedance occurring at the same site as the 

first exceedance in the same calendar year is a violation of the NAAQS.

Contingency Measure - Tier 2: The AQMD will maintain a list of potential contingency 

measures and provide recommendations for implementation to the WCDBOH. The 

recommendations will also include a timeline for adoption and implementation to promptly 

 

12 Emergency Episode Plan (Adopted 03/23/06). 13 WCDBOH Regulations 040.035 and 050.001. 14 WCDBOH Regulation 050.001. 15 WCDBOH Regulation 050.001. 16 WCDBOH Regulations 040.051 and 050.001. 17 WCDBOH Regulations 050.001.
CO Maintenance Plan August 28, 2014 

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correct any violation of the NAAQS. The list of potential contingency measures will concentrate 

on the two significant emission categories that impact CO season emissions. Table 2-8 

summarizes the current list.

Table 2-8 

Potential CO Contingency Measures

Emission Category Potential Contingency Measure 

Residential Wood 

Combustion 

• Increase one acre lot size exemption

• Mandatory curtailment at lower CO concentrations

• Change out program to cleaner burning devices

Mobile Sources • Strengthen inspection & maintenance (smog check) 

program 

• Reinstate oxygenated fuels program

• Non-road & on-road diesel engine repowers and rebuilds 

• Truck Stop Electrification systems

• Fleet modernization

• Strengthen maximum idling time for diesel vehicles

In addition, within 45 days of reaching the second trigger mechanism, the EPA Regional Office 

will be notified that this contingency measure has been implemented. 

Implementation Schedule - Tier 2: Recommendations to the WCDBOH shall occur at their next 

regularly scheduled meeting, but no later than 45 days after triggering the contingency measures. 

The list of potential measures will be reviewed and updated at least once every three years. The 

WCDBOH is the governing body for the AQMD and currently meets on the fourth Thursday 

each month. Because of changes in growth and technology, the effectiveness of each measure 

may vary over time. A triennial review and reprioritization of the measures in coordination with 

the periodic CO emissions inventory should be adequate to anticipate the need for additional 

emission reductions. Contingency measures recommended to the WCDBOH shall be adopted 

and implemented as promptly and expediently as possible. Any adopted measure shall remain in 

effect regardless of changes to Washoe County’s CO attainment status. 

The AQMD two-tiered contingency plan meets Condition 5.e of the Calcagni Memorandum by 

promptly and expediently addressing future exceedances of the CO NAAQS with trigger 

mechanisms, contingency measures, adoption schedules, and implementation schedules. 
Appendix A 

Growth Factors for Emission Projections
Appendix A.1 - Growth Factors for 2015, 2020, 2025, and 2030 Projections

Appropriate and reasonable growth and control assumptions ensure that planning emissions for 

2015 through 2030 are realistically projected. Control factors were developed based on historic 

data and reasonable assumptions. 

Growth and control factors for each emission category are listed in Table A-1. Detailed data for 

the growth factors are further listed in Table A-2. 

Portions of the growth factors are based on various data from the Washoe County Consensus 

Forecast, used by the MPO in the development of its 2035 Regional Transportation Plan (RTP). 

These data are provided in 5-year increment.

The historic climatic data were obtained from the National Oceanic and Atmospheric Agency, 

with future data based on 30-year normal averages between 1980 and 2010.
Table A-1 – Grow & Control Factors used for Truckee Meadows CO Emissions Projection

Major Category Sub-Category

Growth 

Surrogate(s) Control Factor(s)

POINT SOURCES

Geothermal POP None

Printing EMP None

Airports & Heliports

GSE AP None

Military Aircraft UNI None

Commericial Aircraft AP None

Gen Aviation - piston AP None

Gen Aviation - turbine AP None

Air Taxi - piston AP None

Air Taxi - turbine AP None

APU AP None

Buffer Zone POP&EMP None

NONPOINT SOURCES

Stationary Source Fuel Combustion

Industrial Fuel Combustion EMP None

Com/Inst Fuel Combustion EMP None

Res. Fuel Combustion HH&HDD None

Res. Wood Combustion

Fireplaces HDD No new solid fuel device is allowed w/in HA87, unless 

the property has ≥ 1 acre. Since not many parcels 

w/in HA87 are ≥ 1 acre, assumed that no new FPs will 

be installed. Also assumed that 1%/year of wood FPs 

will be replaced with gas FPs.

Woodstoves/Inserts

Non-certified HDD No new non-certified WS allowed. Older stoves being 

removed upon real estate transaction. Assumed 

future replacement apportionment of 75% Phase II 

WS, 20% Pellet stoves, and 5% gas FPs. 

Replacement % derived from historic data for Ph II 

WS & PS.

Certified, Phase 1 HDD No new Phase I WS allowed. Older stoves gradually 

being removed due to age. Assumed 5% reduction 

per year.

Certified, Phase 2 Growth&HDD 

Pellet Stoves Growth&HDD 

Industrial Processes

Chemical Manufacturing EMP None

Commercial Cooking POP None

Food & Kindred Products - Manufacturing EMP None

Mineral Processes EMP None

Rubber/Plastic Processes EMP None

Fabricated Metals EMP None

Construction - Stationary

Road Construction PGR None

Residential Dust Projects (Non-Road 

Const.) PGR None

Commercial Dust Projects (Non-Road 

Const.) EGR None

Asphalt, Sand and Gravel, Abrasive 

Blasting EGR None

Machinery EMP None

Mining and Quarrying - Stationary EMP None

Miscellaneous Industrial Processes EMP None

Solvent Utilization

Architectural Coatings HH None

Auto Refinishing EMP None

Wood Furniture EMP None

Paper EMP None

Plastic Products EMP None

Machinery & Equipment EMP None
Electronic & Other Electrical EMP None

Misc. Manufacturing EMP None

Other Solvent Utilization

Degreasing EMP None

Dry Cleaning EMP None

Graphic Arts EMP None

Misc. Industrial Processes EMP None

Misc. Commercial Processes EMP None

Misc. Consumer/ Com. Solv. EMP None

Cutback Asphalt Application EMP None

Emulsified Asphalt Appl. EMP None

Pesticide, Fungicide & Rodenticide EMP None

Storage and Transport

Gas Service Station EMP None

Organic Chemical Storage EMP None

Waste Disp/Treat/Recovery

Commercial/Industrial Incineration EMP None

Publicly Owned Treatment Works POP/HH None

Remediation/Reclamation/ Recycle EMP None

Misc. Non-Point Sources

Paved Road Fugitive Emissions VMT(RTP)

Paved Road Fugitive Emissions, Sanding & 

Salting

SNO Sand:Salt ratio shifted over the years. Based on 

historic data, anticipate 15% reduction in sand usage 

per year.

Unpaved Road Fugitive Emissions LVMT Assumed 2.6% per year of all future unpaved roads to 

be paved based on WC historic averages from 1985 - 

2011 and past EI unpaved:paved road ratio.

Dirt Road Fugitive Emissions - -

Wildfires UNI None

Structure Fires UNI None

Motor Vehicle Fires UNI None

Firefighting Training UNI None

Open/Permit Burning UNI None

Prescribed Burning UNI None

Refuse Fires UNI None

Auto & Misc. Repair Shops POP None

Health Services, Hospitals POP None

Essay Labs EMP None

Human & Animal Cremation POP None

NON-ROAD MOBILE SOURCES

CNG Engines NR2008a None

Diesel Engines NR2008a None

Gasoline Engines NR2008a None

LPG Engines NR2008a None

Locomotives EMP None

ON-ROAD MOBILE SOURCES

On-Road Vehicles* MOVES2010b None

HDDV Diesel Idling* MOVES2010b None

 * Sub-Category included in MVEB
Table A-2– Growth Factors for 2015-2030 Projections for the Truckee Meadows Hydrographic 

Area

Growth Factors 2010 2011 2015 2020 2025 2030 Reference

Uniform (UNI) 1.000 1.000 1.000 1.000 1.000 1.000 ---

Daily Vehicle Miles Traveled (VMT) 5,773,560 6,080,990 6,157,848 6,596,915 7,040,489 7,390,867

Ratio using 2011 Baseline 1.000 1.013 1.085 1.158 1.215

Local Vehicle Miles Traveled (LVMT) 472,725 497,198 503,316 539,802 585,265 634,418

Ratio using 2011 Baseline 1.000 1.012 1.086 1.177 1.276

Population (POP) 280,881 283,288 292,914 313,771 328,272 341,696

Ratio using 2011 Baseline 1.000 1.034 1.108 1.159 1.206

Population Growth Rate (PGR) 1.000 1.009 1.034 1.071 1.046 1.016

Ratio using 2011 Baseline 1.000 1.025 1.062 1.037 1.007

Households (HH) 113,418 114,468 118,666 127,912 134,278 140,216

Ratio using 2011 Baseline 1.000 1.037 1.117 1.173 1.225

Household Growth Rate (HHGR) 1.000 1.009 1.037 1.078 1.050 1.017

Ratio using 2011 Baseline 1.000 1.027 1.068 1.040 1.008

Employment (EMP) 211,596 215,663 231,931 252,698 274,153 297,252

Ratio using 2011 Baseline 1.000 1.075 1.172 1.271 1.378

Employment Growth Rate (EGR) 1.000 1.019 1.075 1.090 1.085 1.032

Ratio using 2011 Baseline 1.000 1.055 1.069 1.064 1.013

Ag/Mining/Constr Employment (AMC) 14,869 15,114 16,096 17,439 18,847 20,348

Ratio using 2011 Baseline 1.000 1.065 1.154 1.247 1.346

AMC Emp Growth Rate (AMCGR) 1.000 1.017 1.065 1.083 1.081 1.030

Ratio using 2011 Baseline 1.000 1.048 1.066 1.063 1.014

Mfg/Trans/Com/Util/wholesale (MTCUW) 29,049 29,531 31,457 34,059 36,803 39,768

Ratio using 2011 Baseline 1.000 1.065 1.153 1.246 1.347

MTCUW Emp Growth Rate (MTCUWGR) 1.000 1.017 1.065 1.083 1.081 1.031

Ratio using 2011 Baseline 1.000 1.048 1.065 1.063 1.014

Service & Office Emp (SVCOF) 61,942 63,181 68,139 74,567 81,173 88,221

Ratio using 2011 Baseline 1.000 1.078 1.180 1.285 1.396

SVCOF Emp Growth Rate (SVCOGR) 1.000 1.020 1.078 1.094 1.089 1.033

Ratio using 2011 Baseline 1.000 1.057 1.073 1.067 1.013

RNO Airport Passenger (AP) 3,823,393 3,945,186 4,432,360 5,138,320 5,876,196 6,720,031

Ratio using 2011 Baseline 1.000 1.123 1.302 1.489 1.703

2010 is actual data, the rest projected.

Airport Passenger Growth Rate (APGR) 1.000 1.032 1.123 1.159 1.144 1.053

Ratio using 2011 Baseline 1.000 1.089 1.123 1.108 1.020

2010 is actual data, the rest projected.

Heating Degree Days (HDD)* 2,368 2,499 2,501 2,501 2,501 2,501 National Climatic Data Center.

Ratio using 2011 Baseline 1.000 1.001 1.001 1.001 1.001 Normal, Means and Extremes; Reno, NV (RNO)

30-year Normals (1980-2010) for 2015 forward.

Rainfall >= 0.01 inch (Rain)* 34.0 5.0 18.3 18.3 18.3 18.3 National Climatic Data Center.

Ratio using 2011 Baseline 1.000 3.660 3.660 3.660 3.660 Normal, Means and Extremes; Reno, NV (RNO)

30-year Normals (1980-2010) for 2015 forward.

Snowfall >= 1 inch (SNO)* 3.0 1.0 3.8 3.8 3.8 3.8 National Climatic Data Center.

Ratio using 2011 Baseline 1.000 3.800 3.800 3.800 3.800 Normal, Means and Extremes; Reno, NV (RNO)

30-year Normals (1980-2010) for 2015 forward.

Episodic RWC EI Factors:

Rule Penetration 0.85 0.85 0.88 0.88 0.88 0.88

Rule Effectiveness 0.86 0.86 0.74 0.74 0.74 0.74

Control Efficiency 1.00 1.00 1.00 1.00 1.00 1.00

Note: 2011 data is from Washoe County's Emissions Inventory compilation.

* Includes Jan, Nov, & Dec., 2015 - 2030 data are 30-year normal from 1981-2010, from 2013 NOAA Weather Summary file.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

RTC of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

Note: The population and employment data are not specifically included in the main body of the RTP, but were used 

as inputs for the transportation model that generates VMT data. These data (2010, 15, 20, 25, 30) came from 2012 

Washoe County Consensu Forecast, as provided by Judy Althoff/RTC. Airport passenger data, which was also 

used in the RTP, were provided by Peter Bang/RTC.

Washoe County Residential Wood Use Survey 

Reports compiled by InfoSearch for 2009-2010 

(May 2010) & 2012-2013 (May 2013).

RTC of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

RTC of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

RTC of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.

2012 WC Consensus data, as interpreted by RTC 

of Washoe County; "2035 Regional 

Transportation Plan", April 19, 2013.
Appendix A.1 – Residential Wood Combustion 

The 2009-2010 winter season survey was used to estimate the 2011 emission for RWC. An 

adjustment factor of 0.921 based on heating degree days and households was applied to the 

2009-2010 survey to estimate the 2011 emission. This factor accounts for the colder 2009-2010 

winter season and higher population as compared to the 2011-2012 winter season and 

population. 

The most recent survey was completed for the 2012-2013 winter season. Likewise, adjustment 

factor based on heating degree days (HDD) was applied to the 2012-2013 survey to calculate the 

emissions from 2015 through 2030. Since non-certified woodstoves are not allowed within the 

Truckee Meadows, and new installation of certified phase II or fireplaces are only allowed on a 

property with greater or equal to one acre in size, the growth factors for the various RWC 

devices vary. Table A-3 is a summary of the adjustment methodologies used to project future 

RWC emissions. This factor accounts for the milder 2011-2012 winter season (2,499 heating 

degree days) compared to the historic normal (2,501 heating degree days) (Appendix A). This 

estimate is conservative and assumes that projected CO emissions stay consistent with the 

heating degree days and allowable future RWC devices within the Truckee Meadows. It is used 

because RWC in the Truckee Meadows is controlled by a regulation that: 1) is permanent and 

enforceable, 2) does not allow non-EPA certified devices in new dwelling units, and 3) requires 

non-EPA certified devices to be upgraded or removed upon real estate transactions. 

Table A-3 – Truckee Meadows CO Emission Projection Calculation Methodologies for RWC 

RWC Device Future Emission Projection 

Methodology

Rationale

Fireplaces Device number set at 2011 EI level, 

adjusted by HDD.

No new fireplaces can be installed within the 

Truckee Meadows unless the property is greater or 

equal to 1 acre in size.

Also assumed when aging fireplaces are replaced 

with newer ones, 1% per year will be replaced by 

gas fireplaces.

Non-certified 

woodstoves

Device number decreases by 128 per 

annum from 2011 EI level, based on 

the average number of devices 

removed from 2006 - 2012, adjusted 

by HDD.

Non-certified woodstoves are prohibited from 

installation within the Truckee Meadows.

Assumed 100% of the non-certified woodstoves are 

replaced by 75% Phase II woodstoves, 20% pellet 

stoves, and 5% gas fireplaces.

EPA Certified 

Phase I 

woodstoves

Device number is capped at the 2011 

EI level, adjusted by HDD and 5% 

replacement per year.

Since these Phase I devices were replaced by Phase 

II devices in 1990, no new Phase I devices are 

allowed within the Truckee Meadows.

EPA Certified 

Phase II 

woodstoves

Device number increases by 96 per 

annum from 2011 EI level, which is 

75% of the average non-certified 

stoves being removed annually, 

adjusted by HDD.

Assumed that 75% of the non-certified woodstoves 

are replaced with EPA certified phase II devices. 

This is a more conservative estimate, not accounting 

for some of the non-certified woodstoves that could 

have been removed without being replaced.

Pellet stoves Device number increases by 26 per 

annum from 2011 EI level, which is 

20% of the average non-certified 

stoves being removed annually, 

adjusted by HDD.

Assumed that 20% of the non-certified woodstoves 

are replaced with pellet stoves. This is a more 

conservative estimate, not accounting for some of 

the non-certified woodstoves that could have been 

removed without being replaced.
Appendix B 

Truckee Meadows Projected CO Seasonal Emissions 
Table B-1 – Truckee Meadows Projected CO Seasonal Emissions (lbs/day) 

Major Category Sub-Category

2011 

Attain EI 

2011

Maint Em Limit 

Projected CO Emissions (lbs/day)

2015 2020 2025 2030

POINT SOURCES

Geothermal N/A N/A N/A N/A N/A N/A 

Printing N/A N/A N/A N/A N/A N/A 

Airports & Heliports

GSE 1,280 1,280 1,438 1,668 1,907 2,181 

Military Aircraft 65 65 65 65 65 65 

Commericial Aircraft 767 767 861 998 1,142 1,306 

Gen Aviation - piston 860 860 966 1,120 1,280 1,464 

Gen Aviation - turbine 163 163 183 212 243 278 

Air Taxi - piston 108 108 121 140 160 183 

Air Taxi - turbine 63 63 70 82 93 107 

APU 55 55 62 72 82 94 

Buffer Zone N/A N/A N/A N/A N/A N/A 

Subtotal 3,361 3,361 3,768 4,357 4,974 5,678 

NONPOINT SOURCES

Stationary Source Fuel Combustion

Industrial Fuel Combustion 419 419 451 491 533 578 

Com/Inst Fuel Combustion 1,672 1,672 1,798 1,959 2,125 2,304 

Res. Fuel Combustion 1,300 1,300 1,349 1,454 1,527 1,594 

Res. Wood Combustion

Fireplaces 25,804 25,804 24,772 23,552 22,392 21,290 

Woodstoves/Inserts

Non-certified 9,547 9,547 8,007 6,073 4,139 2,205 

Certified, Phase 1 4,952 4,952 4,002 3,002 2,251 1,266 

Certified, Phase 2 4,333 4,333 5,310 6,467 7,547 8,699 

Pellet Stoves 826 826 868 920 973 1,025 

Subtotal 48,853 48,853 46,557 43,918 41,487 38,961 

Industrial Processes

Chemical Manufacturing - - - - - -

Commercial Cooking 507 507 524 562 588 612 

Food & Kindred Products - Manufacturing 3 3 3 3 3 4 

Mineral Processes 37 37 40 44 47 51 

Rubber/Plastic Processes - - - - - -

Fabricated Metals 1 1 1 1 1 1 

Construction - Stationary

Road Construction - - - - - -

Residential Dust Projects (Non-Road Const.) - - - - - -

Commercial Dust Projects (Non-Road Const.) - - - - - -

Asphalt, Sand and Gravel, Abrasive Blasting 111 111 117 119 118 113 

Machinery 4 4 4 5 5 6 

Mining and Quarrying - Stationary 0 0 0 0 0 0 

Miscellaneous Industrial Processes 93 93 100 109 118 128 

Subtotal 756 756 790 842 881 914 

Solvent Utilization

Architectural Coatings - - - - - -

Auto Refinishing - - - - - -

Wood Furniture - - - - - -

Paper - - - - - -

Plastic Products - - - - - -

Machinery & Equipment - - - - - -

Electronic & Other Electrical - - - - - -

Misc. Manufacturing - - - - - -

Subtotal - - - - - -

Other Solvent Utilization

Degreasing - - - - - -

Dry Cleaning - - - - - -

Graphic Arts - - - - - -

Misc. Industrial Processes - - - - - -

Misc. Commercial Processes - - - - - -

Misc. Consumer/ Com. Solv. - - - - - -

Cutback Asphalt Application - - - - - -

Emulsified Asphalt Appl. - - - - - -

Pesticide, Fungicide & Rodenticide - - - - - -

Subtotal - - - - - -

Storage and Transport

Gas Service Station - - - - - -

Organic Chemical Storage 18 18 20 22 23 25 

Subtotal 18 18 20 22 23 25 

Waste Disp/Treat/Recovery

Commercial/Industrial Incineration - - - - - -

Publicly Owned Treatment Works N/A N/A N/A N/A N/A N/A 

Remediation/Reclamation/ Recycle 1 1 1 1 1 1 

Subtotal 1 1 1 1 1 1 
Misc. Non-Point Sources

Paved Road Fugitive Emissions - - - - - -

Paved Road Fugitive Emissions, Sanding & Salting - - - - - -

Unpaved Road Fugitive Emissions - - - - - -

Dirt Road Fugitive Emissions - - - - - -

Wildfires 105,092 217 217 217 217 217 

Structure Fires 86 86 86 86 86 86 

Motor Vehicle Fires 5 5 5 5 5 5 

Firefighting Training - - - - - -

Open/Permit Burning 105 105 105 105 105 105 

Prescribed Burning - - - - - -

Refuse Fires 37 37 37 37 37 37 

Auto & Misc. Repair Shops 0 0 0 0 0 0 

Health Services, Hospitals - - - - - -

Essay Labs N/A N/A N/A N/A N/A N/A 

Human & Animal Cremation 4 4 4 4 4 4 

Subtotal 105,328 453 453 453 454 454 

TOTAL NONPOINT SOURCES 154,956 50,081 47,820 45,236 42,845 40,355 

NON-ROAD MOBILE SOURCES

CNG Engines 196 196 134 106 101 100 

Diesel Engines 2,427 2,427 1,986 1,236 824 626 

Gasoline Engines 45,010 45,010 40,320 43,149 46,535 50,040 

LPG Engines 2,985 2,985 1,191 792 747 769 

Locomotives 88 88 94 103 112 121 

Subtotal 50,706 50,706 43,725 45,385 48,320 51,656 

ON-ROAD MOBILE SOURCES

On-Road Vehicles* 162,988 162,988 149,794 139,529 138,288 141,961 

HDDV Diesel Idling* 512 512 536 600 649 725 

Subtotal 163,500 163,500 150,330 140,129 138,938 142,686 

Grand Total 372,522 267,648 245,642 235,107 235,077 240,375 

Safety Margin 22,006 32,540 32,571 27,272 

 * Sub-Category included in MVEB 172,336 172,670 171,509 169,959