Eight–Hour Ozone Redesignation Request and 

Maintenance Plan for the Knoxville, Tennessee 

Eight-Hour Ozone Nonattainment Area 

(1997 Ozone NAAQS) 

July 2010 

Prepared by: 

Tennessee Department of Environment and Conservation 

Division of Air Pollution Control 

9th Floor L&C Annex 

401 Church Street 

Nashville, TN 37243

TABLE OF CONTENTS 

Page

LIST OF TABLES ii

LIST OF FIGURES iii

LIST OF ATTACHMENTS iv

LIST OF ACRONYMS v

ACKNOWLDEDGEMENTS vi

EXECUTIVE SUMMARY 1

1.0 INTRODUCTION 2

2.0 AIR QUALITY 5

3.0 PERMANENT AND ENFORCEABLE REDUCTIONS 25

4.0 MAINTENANCE DEMONSTRATION AND EMISSION INVENTORY 31

5.0 CONTINGENCY MEASURES 41

6.0 CONCLUSIONS 44

i 
LIST OF TABLES 

Table 2-1: Knoxville MSA Fourth Highest Values by Year 

Table 2-2: Knoxville MSA Ozone 3-Year Design Values 

Table 2-3: Knoxville MSA Ozone Design Value Projections for 2010 

Table 2-4: Summary of Knoxville Area Temperature, 1999-2009 

Table 2-5: Summary of Knoxville Area Wind Speed, 1999-2009 

Table 2-6: Summary of Knoxville Area Precipitation, 1999-2009 

Table 2-7: 2002-2008 Knoxville Region Ozone Forecasting Results 

Table 2-8: Ozone Data Capture 2003-2008 (March 1 to October 31) 

Table 2-9: Relationship of Temperature and Ozone Exceedances by Year 

Table 2-10: Summary of Emissions and 8-Hour Ozone Concentrations, 1996-2007 

Table 2-11: Region 4 Ozone Summary, Average of All Monitors 

Table 2-12: Region 4 Ozone Summary, Individual Monitors 

Table 3-1: Comparison of Emission Budgets for NOX SIP Call and CAIR Ozone Season 

NOX Trading Program

Table 3-2 Bull Run Fossil Plant NOX Emission Reductions Under the NOX Budget Trading 

Program and CAIR NOX Ozone Season Trading Program

Table 3-3 Kingston Fossil Plant NOX Emission Reductions Under the NOX Budget Trading 

Program and CAIR NOX Ozone Season Trading Program

Table 3-4 Table 3- 4: NOX Budget Trading Program – Regional Reductions Statewide NOX

Reductions from 2000-2008 (Ranked by % Reduction) 

Table 4-1: Point Source NOX Emissions for a Typical Summer Day 

Table 4-2: Point Source VOC Emissions for a Typical Summer Day 

Table 4-3: Top Five NOX Sources in 2007 

Table 4-4: Top Five VOC Sources in 2007 

Table 4-5: Area Source NOX Emissions 

Table 4-6: Area Source VOC Emissions 

Table 4-7: Seasonally Adjusted Summer Daily Vehicle Miles Traveled 

Table 4-8: Onroad NOX Emissions Summary for the Knoxville 8-hour Ozone Nonattainment 

Area 

Table 4-9: Onroad VOC Emissions Summary for the Knoxville 8-hour Ozone Nonattainment 

Area 

Table 4-10: Emission Projections for the Knoxville Area 

Table 4-11: Motor Vehicle Emissions Budgets for NOX and VOC for 2024 

Table 4-12: NOX Emissions from Nonroad Sources (excluding Commercial Marine, 

Locomotive and Aircraft) 

Table 4-13: VOC Emissions from Nonroad Sources (excluding Commercial Marine, 

Locomotive and Aircraft) 

Table 4-14: NOX Emissions from Locomotive, Commercial Marine, and Aircraft 

Table 4-15: VOC Emissions from Locomotive, Commercial Marine, and Aircraft 

LIST OF FIGURES 

ii 
Figure 1-1: Knoxville Area Geologic Regions 

Figure 2-1: Knoxville, Tennessee Ozone Nonattainment Area 

Figure 2-2: Knoxville MSA Ozone Trends, 4th Highest 8-Hour Ozone Concentration by Year

Figure 2-3: Knoxville MSA Ozone Design Value Trends, Low Elevation Monitoring Sites 

Figure 2-4: Knoxville MSA Ozone Design Value Trends, High Elevation Monitoring Sites 

Figure 2-5: Trajectory Analyses, 2006/2007-2009 

Figure 2-6: Relationship of High Temperature Days and Ozone NAAQS Exceedances in the 

Knoxville Region 

Figure 2-7: Scatter Plot of Temperature and Ozone Exceedances, 1999-2009 

Figure 2-8: July/August Mean Daily Maximum Temperature and Ozone Exceedances, 1999-

2009 

Figure 2-9: Comparison of Temperature and Ozone Exceedances with 1999 Baseline 

Figure 2-10: July/August Precipitation and Ozone Exceedances, 1999-2009 

Figure 2-11: July/August Wind Speed and Ozone Exceedances, 1999-2009 

Figure 2-12: Emission and 8-Hour Ozone Trends, 1996-2005 

Figure 2-13: Scatter Plots of Emissions and Ozone Exceedances 

Figure 2-14: Scatter Plot of NOX Emissions and Ozone Exceedances (1999 Data Omitted) 

Figure 2-15: National Ozone Trends, 2004 – 2008 

Figure 2-16: Seasonal Ozone Concentrations Adjusted for Weather 

Figure 2-17: 2007 Georgia Wildfires 

iii 
LIST OF ATTACHMENTS 

ATTACHMENT A: Emission Inventory

ATTACHMENT B: Public Hearing Notice 

ATTACHMENT C: Public Comments and Response 

ATTACHMENT D: Air Pollution Control Board Order 

iv 
LIST OF ACRONYMS 

Acronym Definition 

AIRS Aerometric Information Retrieval System

ALM Aircraft, Locomotive, and Marine 

APC Division of Air Pollution Control, Tennessee Department & Conservation 

AQS Air Quality System

CAA Clean Air Act 

CAIR Clean Air Interstate Rule 

CERR Consolidated Emissions Reporting Rule 

CFR Code of Federal Regulations 

CHIEF Clearinghouse for Emission Inventories and Emission Factors 

CMV Commercial Marine Vessel 

CO Carbon Monoxide 

DAQM Knoxville Department of Air Quality Management 

DV Design Value 

DVMT Daily Vehicle Miles Traveled 

EGAS 5.0 Economic Growth Analysis System version 5.0 

EPA U.S. Environmental Protection Agency 

oF Degrees Fahrenheit 

FR Federal Register 

GSMNP Great Smoky Mountains National Park 

HC Hydrocarbons 

HYSPLIT Hybrid Single Particle Lagrangian Integrated Trajectory Model 

IAC Interagency Consultation 

lb/MMBtu Pounds per Million British Thermal Units 

MLA Marine, Locomotive and Aircraft 

MSA Metropolitan Statistical Area 

MVEB Motor Vehicle Emissions Budget 

NAAQS National Ambient Air Quality Standard 

NEI National Emission Inventory 

NOAA National Oceanic and Atmospheric Administration 

NOx Nitrogen Oxides 

ppm Parts per million 

QA/QC Quality Assure/Quality Controlled 

RACT Reasonably Available Control Technology 

REMI Regional Economic Model, Inc. 

SCC Source Classification Code 

SIP State Implementation Plan 

TDEC Tennessee Department of Environment and Conservation 

TDOT Tennessee Department of Transportation 

tpd tons/day 

TPO Knoxville Transportation Planning Organization 

VMT Vehicle Miles Traveled 

VOC Volatile Organic Compounds 

v 

EXECUTIVE SUMMARY 

The Knoxville, Tennessee ozone nonattainment area includes Anderson, Blount, Jefferson, Knox, 

Loudon and Sevier Counties in their entirety, as well as the portion of Cocke County that falls within 

the boundaries of the Great Smoky Mountains National Park. Between 1999 and 2003, air quality 

monitoring at several sites within this region indicated that the highest 8-hour average ozone 

concentrations exceeded the 0.08 parts per million National Ambient Air Quality Standard 

(NAAQS), and EPA designated the area as nonattainment for the 8-hour ozone NAAQS, effective 

June 15, 2004. More recently, air quality monitoring data for 2007 through 2009 indicates declining 

ozone concentrations in the Knoxville area, and the design value at the controlling monitor shows 

attainment of the NAAQS. 

Tennessee is petitioning EPA for redesignation of the Knoxville 8-hour ozone nonattainment area to 

attainment for the 1997 8-hour ozone NAAQS, based on an attaining three-year design value for the 

period 2007-2009. This petition is submitted pursuant to §107(d)(3) of the Clean Air Act, which 

specifies the requirements for redesignation of nonattainment areas. 

This petition will show that the Knoxville nonattainment area has attained the National Ambient Air 

Quality Standard and that the observed reduction in ozone levels is due to permanent and 

enforceable emission reductions at the Federal, State, and local levels. In addition, an emissions 

inventory is included, which indicates declining emissions of NOX and VOC between 2007 and 

2024. As emissions of these ozone precursors continue to decline, the region is likely to remain in 

attainment of the NAAQS in the future. However, this petition includes contingency measures that 

may be put into place, if necessary, to correct NAAQS violations that may occur after redesignation 

of the area to attainment. 

1 
1.0 INTRODUCTION 

This petition is submitted to the United States Environmental Protection Agency (EPA) to request 

redesignation of the Knoxville, Tennessee ozone nonattainment area from nonattainment to 

attainment for the 8–hour ozone National Ambient Air Quality Standard (NAAQS), pursuant to 

§107(d)(3) of the Clean Air Act (CAA). The Act specifies the following requirements for 

redesignation of nonattainment areas: 

1. The Administrator determines that the area has attained the national ambient air quality 

standard; 

2. The Administrator has fully approved the applicable implementation plan for the area under 

section 110(k); 

3. The Administrator determines that the improvement in air quality is due to permanent and 

enforceable reductions in emissions resulting from implementation of the applicable 

implementation plan and applicable Federal air pollutant control regulations and other 

permanent and enforceable reductions; 

4. The Administrator has fully approved a maintenance plan for the area as meeting the 

requirements of section 175A; and 

5. The State containing such area has met all requirements applicable to the area under section 

110 and part D. 

Tennessee is petitioning EPA for redesignation of the Knoxville 8-hour ozone nonattainment area to 

attainment based on an attaining three-year design value for the period 2007-2009. This document 

demonstrates that the Knoxville 8-hour ozone nonattainment area meets the above requirements, and 

can petition the EPA for redesignation in lieu of an attainment demonstration. Submission of an 

attainment demonstration in place of this redesignation request would not necessarily result in 

additional controls, since ambient air quality data indicates that the area is attaining the NAAQS, 

and since attainment has been achieved using existing controls (see Section 3.0 for additional 

information). This petition does not preclude Tennessee from implementing additional controls in 

the Knoxville area in order to avoid future designations resulting from future revisions of the 8-hour 

ozone NAAQS. 

Knoxville Geologic Region

Ridge and Valley 

The city of Knoxville is located within the Ridge and Valley region of Tennessee, which is located 

between the Cumberland Plateau to the west and the Blue Ridge Mountains to the east (Figure 1-1). 

The width of the region ranges from 30 to 70 miles, with an average width of 45 miles. The 

topography of the Ridge and Valley consists of long linear ridges and parallel lowland valleys that 

trend in a northeast to southwest direction. The ridges usually have high elevations of 1,100 to 

2 
1,500 feet1

 while the adjacent valley floors vary from 700 to 1,000 feet. The ridges and valleys 

generally have high elevations in the northern part of the region, with slightly lower elevations to the 

south. 

Blue Ridge and Great Smoky Mountains 

The Blue Ridge and Great Smoky Mountains2

 extend along the Tennessee-North Carolina border 

and is the easternmost physiographic province in Tennessee. This region consists of high peaks and 

heavily forested terrain, broken by deeply carved stream valleys. The Great Smoky Mountains 

includes the highest point in the State at Clingman’s Dome (6,643 ft) in Sevier County. In addition 

to Clingman’s Dome, there are 13 other mountain peaks in the Blue Ridge with heights of over 

6,000 feet and 33 peaks of more than 5,000 feet. A large percentage of those peaks are situated 

directly on the Tennessee/North Carolina border, with the greatest concentration found in Sevier 

County. Narrow lowland valleys and isolated coves, ranging from 1,000 to 2,000 feet in elevation, 

are also a part of the region’s topography. 

Figure 1-1: Knoxville Area Geologic Regions 

Climate Synopsis for East Tennessee3

Tennessee’s topography is highly varied and has a significant impact on the state's climate. The 

landscape varies generally from west to east, starting with the gently rolling lowlands in the west, 

and dominated by the Blue Ridge Mountains in the east. Average annual temperatures across the 

State range from about 55° F to 60° F, with mean winter temperatures of about 35° F and summer 

temperatures 75° to 80° F. These general patterns are affected by topography, and the mountain 

areas tend to have milder summers and colder, more blustery winters. In the Ridge and Valley 

region of east Tennessee, annual precipitation ranges from 40 inches in the north to over 50 inches in 

 

1 All elevations are relative to sea level. 

2 The Great Smoky Mountains are part of the Blue Ridge Mountains, which run from northern Georgia to Pennsylvania. 

“Great Smoky Mountains” typically refers to the portion of the Blue Ridge located in Blount, Cocke, and Sevier Counties 

in Tennessee, and within the adjacent North Carolina counties. 

3 Adapted from: Climatography of the United States, No. 60, National Climatic Center 

3 
the south. The Blue Ridge region is the wettest part of the State, with annual totals of up to 80 inches 

in the higher elevations. In general, the greatest precipitation occurs in winter and early spring4

, 

with a secondary maximum of precipitation from midsummer thunderstorms. 

Knoxville MSA Meteorology

The climate of the Knoxville MSA is strongly influenced by the surrounding mountains. July is 

usually the warmest month of the year, and the coldest weather typically occurs during January. 

Sudden temperature changes are infrequent, mainly due to the retarding effect of the mountains. The 

average high temperature for the year is 69.3 degrees, but during the ozone season, the average high 

temperature rises to 77.8 degrees. Daytime winds usually have a southwesterly component, while 

nighttime winds usually move from the northeast. The winds are relatively light, averaging 6.9 mph 

for the year, and during ozone season, the average wind speed decreases to 6.6 mph. 

Rainfall is favorably distributed during the year. Precipitation is greatest in the winter, with a 

secondary peak during the late spring and summer months. The period of lowest rainfall occurs 

during the fall. The surrounding mountains serve as a fixed incline plane, which lifts the warm, 

moist air flowing northward from the Gulf of Mexico and increases the frequency of afternoon 

thunderstorms. These thunderstorms reduce the number of extremely warm days in the valley and 

provide relief from extremely high temperatures. 

 

4 The higher rainfall totals in winter and early spring are primarily due to the more frequent passage of large-scale 

(frontal) storms. 

4 
2.0 AIR QUALITY 

Tropospheric ozone is a secondary pollutant that is formed in the ambient air by the photochemical 

reaction of nitrogen oxides (NOx) and reactive volatile organic compounds (VOC). This pollutant is 

associated with a number of health and environmental impacts, including respiratory impairment and 

damage to crops and forests. High ozone concentrations tend to occur in the eastern United States 

during the hot summer months under hot, stagnant conditions. EPA mandates seasonal monitoring 

of ambient ozone concentrations in Tennessee and other States from March 1 through October 31 

(40 CFR 58 Appendix. D). 

Because ozone is formed in the ambient air, control of ozone focuses upon reduction of precursor 

emissions. Nitrogen oxides (NOX) are formed from the high-temperature reaction of nitrogen and 

oxygen during combustion processes, such as electric utility boilers, industrial fuel-burning sources, 

and motor vehicles. VOC includes many industrial solvents and coatings, as well as the 

hydrocarbons (HC) that are emitted by motor vehicles as evaporative losses from gasoline, and 

tailpipe emissions of unburned hydrocarbon. Past efforts at control of ground-level ozone have 

focused primarily upon reduction of VOC emissions at a local level, through control of automotive 

emissions and industrial solvent/coating reasonably available control technology (RACT). In recent 

years, control of NOX emissions has increased in importance, both at the local and regional levels. 

The Knoxville Tennessee ozone nonattainment area includes Anderson, Blount, Jefferson, Knox, 

Loudon and Sevier Counties in their entirety, as well as the portion of Cocke County that falls within 

the boundaries of the Great Smoky Mountains National Park (Figure 2-1). Between 1999 and 2003, 

air quality monitoring at several sites within this region indicated that the highest 8-hour average 

ozone concentrations exceeded the 0.085 parts per million NAAQS (Table 2-1, Table 2-2). EPA 

subsequently designated the area as nonattainment for the 8-hour ozone NAAQS, effective June 15, 

20045

. The area was designated as a Basic nonattainment area, pursuant to Subpart 1 of the 1990 

Clean Air Act Amendments. The Subpart 1 designation was vacated by the U. S. Court of Appeals 

for the District of Columbia Circuit in 20066

, and EPA published a proposed rule on January 16, 

2009, to designate the area as a Subpart 2 Moderate nonattainment area for ozone7

. More recently, 

air quality monitoring data for 2007 through 2009 indicates declining ozone concentrations in the 

Knoxville area, and the design value at the controlling monitor is now 0.082 ppm. 

 

5 Federal Register Notice published April 30, 2004 

6 South Coast Air Quality Management District vs. EPA, December 22, 2006. 

7 Federal Register, January 16, 2009, pp 2936 – 2945. 

5 
Figure 2-1: Knoxville, Tennessee Ozone Nonattainment Area 

Table 2-1: Knoxville MSA Fourth Highest Values by Year 

Fourth-Highest Value (ppm) 

County Site Name Monitor ID 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 

Anderson 

Freels Bend Study

Area 470010101-1 0.094 0.093 0.085 0.099 0.078 0.069 0.081 0.080 0.080 0.073 0.066

Blount Look Rock, GSMNP 470090101-1 0.106 0.096 0.086 0.102 0.090 0.082 0.086 0.085 0.088 0.082 0.068

Cades Cove, GSMNP 470090102-1 0.088 0.081 0.075 0.082 0.071 0.066 0.066 0.071 0.074 0.071 0.062

Jefferson 

1188 Lost Creek 

Road 470890002-1 0.103 0.095 0.091 0.099 0.085 0.078 0.084 0.083 0.085 0.075 0.068

Knox 9315 Rutledge Pike 470930021-1 0.098 0.096 0.086 0.095 0.085 0.072 0.081 0.077 0.087 0.079 0.065

4625 Mildred Drive* 470931020-1 0.099 0.100 0.090 0.098 0.090 0.078 0.086 0.086 0.092 0.086 0.068

Loudon 130 Webb Drive 47105108-1 N/A N/A N/A N/A N/A 0.077 0.085 0.082 0.088 0.077 0.067

Cove Mountain,

GSMNP 47155101-1 0.101 0.096 0.091 0.103 0.082 0.074 0.079 0.080 0.088 0.079 0.069

Sevier Clingman’s Dome,

GSMNP 471550102-1 0.101 0.100 0.093 0.101 0.084 0.076 0.078 0.086 0.087 0.08 0.071

* Controlling monitor.

6 
Table 2-2: Knoxville MSA Ozone 3-Year Design Values 

Eight-Hour Design Values (ppm) 

County Site Name Monitor ID 

2001-

2003 

2002-

2004 

2003-

2005 

 2004-

2006 

2005-

2007 

2006-

2008 

2007-

2009 

Anderson 

Freels Bend 

Study Area 470010101-1 0.087 0.082 0.076 0.076 0.080 0.078 0.073 

Look Rock, 

GSMNP 470090101-1 0.092 0.091 0.086 0.084 0.086 0.085 0.079 

Blount Cades Cove, 

GSMNP 470090102-1 0.076 0.073 0.067 0.067 0.070 0.072 0.069 

Jefferson 

1188 Lost 

Creek Road 470890002-1 0.091 0.087 0.082 0.081 0.084 0.081 0.076 

9315 Rutledge 

Pike 470930021-1 0.088 0.084 0.079 0.076 0.082 0.081 0.077 

Knox 4625 Mildred 

Drive 470931020-1 0.092 0.088 0.084 0.083 0.088 0.088 0.082 

Loudon 

130 Webb 

Drive 47105108-1 N/A N/A N/A 0.081 0.085 0.082 0.077 

Cove Mountain, 

GSMNP 47155101-1 0.092 0.086 0.078 0.077 0.082 0.082 0.079 

Sevier Clingman’s 

Dome, GSMNP 471550102-1 0.092 0.087 0.079 0.080 0.083 0.084 0.079

In accordance with CAA §110 (k), Tennessee’s request to amend the State Implementation Plan is 

based on the most recent three years of data, which show no additional violations of the ozone 

NAAQS for the 2007, 2008, and 2009 ozone seasons. Data collected from the monitoring networks8

were extracted from the EPA AIRS-AQS database and used to perform an evaluation into the 

possible future ozone trend for this area. The fourth highest 8-hour ozone concentrations were 

plotted for each successive year from 2001 through 2006, grouping the air quality monitoring 

stations into high elevation (more than 2,500 feet above sea level) and low elevation sites (Figure 2-

2). The 8-hour ozone design values (DVs) were also plotted (Figure 2-3, Figure 2-4) to observe 

trends of individual monitoring sites. Figure 2-2 indicates that, between 1999 and 2009, ozone 

concentrations declined noticeably at both high and low elevations. More importantly, the data 

indicates that the 8-hour ozone design values (2007 – 2009) are attaining the NAAQS at all 

monitored locations. While ozone concentrations may be affected by a variety of factors, the most 

likely explanation for this decline is the reduction in local and regional NOX emissions that have 

occurred since 2004 (see Section 3.0 for additional discussion of emission reductions). 

 

8 The following air quality monitors are operated in the Knoxville nonattainment area: a) monitors located in Knox 

county are operated by the local air pollution control program; b) monitors in Blount and Sevier counties are operated by 

the National Park Service; and c) monitors located in Anderson, Jefferson, and Loudon counties are operated by TDEC. 

7 
Figure 2-2: Knoxville MSA Ozone Trends 

4th Highest 8-Hour Ozone Concentration by Year 

0.060

0.065

0.070

0.075

0.080

0.085

0.090

0.095

0.100

0.105

1999 2000 2001 2002 2003 2004 2005 2006* 2007 2008 2009

4th Highest Value (ppm)

High Elevation Sites Low Elevation Sites NAAQS

TVA Bull Run SCR 

online

TVA Kingston Units 1-8

SCRs online

Liberty Fibers shutdown

TVA Kingston Unit 9

SCR online

8 
Figure 2-3: Knoxville MSA Ozone Design Value Trends 

Low Elevation Monitoring Sites 

0.06

0.065

0.07

0.075

0.08

0.085

0.09

0.095

2001-2003 2002-2004 2003-2005 2004-2006 2005-2007 2006-2008 2007-2009

8-hour Design Value

(ppm)

Mildred Drive Lost Creek Road Rutledge Pike Freels Bend Cades Cove

9 
Figure 2-4: Knoxville MSA Ozone Design Value Trends 

High Elevation Monitoring Sites 

0.06

0.065

0.07

0.075

0.08

0.085

0.09

0.095

2001-2003 2002-2004 2003-2005 2004-2006 2005-2007 2006-2008 2007-2009

8-hour Design Value 

(ppm)

Look Rock Cove Mountain Clingman’s Dome

Ozone formation is influenced by a variety of factors, including meteorology and precursor 

emissions. Although the longer-range trend indicates declining ozone concentrations, some

fluctuation may be observed from year to year at different monitoring sites. 

To assess the allowable extent of year-to-year variation at each monitoring site, a hypothetical 

fourth-highest 8-hour ozone concentration was calculated for each monitor for 2010, to determine 

the ozone concentrations that would result in a NAAQS violation (Table 2-3). At the controlling 

low-elevation monitor (Mildred Drive), the NAAQS would be exceeded in 2010 if the fourth highest 

8-hour ozone concentration was at least 0.101 ppm. A slightly higher value of 0.104 ppm would be 

required to result in a NAAQS violation at the controlling high elevation monitor (Clingman’s 

Dome). 

10 
Table 2-3: Knoxville MSA Ozone Design Value Projections for 2010

County Site Name Monitor ID 

 2008 4th

Max. 

 2009 4th

Max. 

2010 4th Max 

Needed for 8-hr 

DV Violation 

Anderson Freels Bend Study Area 470010101-1 0.073 0.066 0.117

Look Rock, GSMNP 470090101-1 0.082 0.068 0.104 

Blount Cades Cove, GSMNP 470090102-1 0.071 0.062 0.122

Jefferson 1188 Lost Creek Road 470890002-1 0.075 0.068 0.112

9315 Rutledge Pike 470930021-1 0.079 0.065 0.110

Knox 4625 Mildred Drive 470931020-1 0.086 0.068 0.101

Loudon 130 Webb Drive 47105108-1 0.077 0.067 0.111

Cove Mountain, 

GSMNP 47155101-1 0.079 0.069 0.106 

Sevier 

Clingman’s Dome, 

GSMNP 471550102-1 0.08 0.071 0.104 

High-elevation monitoring site 

Prevalence of Ozone in the Knoxville Region

Trajectory Analysis 

The overall wind patterns for a number of high ozone days in the Knoxville region, including the 

periods from 2006-2009 (highest days) and 2007-2009 (days with more than one exceedance), were 

evaluated using NOAA HYSPLIT trajectory analysis. The results of this analysis indicate that a 

limited number of exceedances were observed on days with significant local recirculation. This 

analysis also suggests that ozone transport into the Knoxville region was a significant contributor to

ozone levels on a number of high ozone days, with the potential to impact both low and high 

elevation monitoring sites. The composite data is presented in Figure 2-5: 

11 
Figure 2-5: Trajectory Analyses, 2006/2007-2009 

1,500 Meter Analysis

2,500 Meter Analysis

2006 to 2009 Highest Days 2007 to 2009 Days with More Than 1 Exceedance 

2006 to 2009 Highest Days 2007 to 2009 Days with More Than 1 Exceedance 

12 
13 

Influences of Meteorology on Ozone Formation

Meteorological data for the Knoxville area are summarized in Tables 2-4, 2-5, and 2-6. The 

influence of these parameters on ambient ozone concentrations will be discussed on following pages. 

Ozone Forecasting Activities in the Knoxville Region 

The Division of Air Pollution Control (APC) began forecasting for ozone in 2004, with forecasts 

issued for the Knoxville area and the Great Smoky Mountains National Park (GSMNP). Current 

forecasts are based on a mathematical forecast model that incorporates current and historic ozone 

measurements with meteorology. The forecast is also dependent upon the intuition and skill of the 

forecast meteorologist. 

The results of APC’s forecasting efforts are summarized in Table 2-7. The low percentage of missed 

action days indicates that the program has been very effective. During the summer ozone season, 

these forecasts can assist in reduction of precursor emissions in the Knoxville region. 

Data Capture for the Knoxville Region Ozone Monitoring Sites 

The ozone monitoring sites in the Knoxville region exhibited excellent data capture rates during the 

2003 through 2008 monitoring period, with an overall average data capture of 93.8% (Table 2-8). 

This includes the three monitoring sites located at high elevations in the GSMNP. Typically, 

Clingman’s Dome has lower data capture rates, because it is started up two months later in the ozone 

monitoring season (the Clingman’s Dome site is inaccessible during March and April). 

Data Validation and Quality Assurance 

All data used in this evaluation have been processed and validated by the respective reporting 

agencies responsible for the final data validation. Data for the years 2003 through 2006 were 

extracted from the certified data in the AIRS AQS subsystem. Data accuracy and precision results 

are also available from AIRS AQS, however, these data are not included in this summary. 
Table 2-4: Summary of Knoxville Area Temperature, 1999-2009 

Mea

n Daily Ma

ximum Temperature (°F) 

Year March April May June July August September October 

Seas

Aver

19

9

9 55.6

71.5 78.0 85.3 87.2 88.8 83.3 7

0.8 7

7.

2

0

0

0

6

4.7

6

6.2 80.0 84.2 86.7 86.5 80.7

73.9

7

7.

2

0

01 55.5 7

2.4

78.9 83.0 86.9 86.3 78.0

6

9.9

7

6.

2

0

0

2

61.8 73.9

7

6.4 87.7 88.0 89.8 84.8 7

0.2

7

9.

2

0

03 6

4.4

7

0.8 7

6.4 81.6 84.9 86.9

7

9.5 6

9.5 7

6.

2

0

0

4

6

4.2

6

9.7 81.7 82.8 85.9 82.9

7

9.6

7

2.7

7

7.

2

0

05 59.5 6

9.9

75.5 84.5 86.9 88.7 86.5 7

2.4

78.

2

0

0

6

61.7

75.0

7

6.0 86.6

9

0.1 89.8 7

7.6

6

7.3 78.

2

0

0

7

6

9.1 6

7.4 82.5 88.5 87.1 9

4.7 86.4

7

7.0 81.

2

0

08 6

0.6

6

9.7

7

7.2 87.6 88.5 87.6 83.2

7

0.9

78.

2

0

0

9

61.2

7

0.1 7

7.1 85.8 83.4 85.5 7

9.4

6

7.4

7

6.

Table 2-5: Summary of Knoxville Area Wind Speed, 1999-2009 

Mean Wind Speed (mph) 

Year March April May June July August September October 

Seas

Aver

19

9

9

7.4 8.7 5.7

6.3 5.0 5.6

4.7

4.4

6.0 

2

0

0

0

6.8 7.7

7.4 5.4 5.0 5.1 5.5 3.4 5.8 

2

0

01 7.7

7.2

6.5 5.6 5.9 5.4

4.8 5.6

6.

2

0

0

2 8.2

7.4

6.9 5.9 5.3 5.0 5.2

4.7

6.

2

0

03 6.5 7.2

7.5 6.0

6.3 4.3 4.6

4.3 5.8 

2

0

0

4

7.8 7.0

6.6 5.1 5.5 5.2 5.5 5.6

6.0 

2

0

05 8.6

7.2 5.3 4.8 5.9

4.7

4.4

4.9 5.7 

2

0

0

6 8.7

7.6

7.0 5.7 5.8 4.7 5.2 5.6

6.3 

2

0

0

7

6.9

7.2

4.5 5.1 5.8 4.3 3.8 4.4 5.3 

2

0

08 7.9

6.1 7.3 5.7 5.0

4.0

4.4

4.5 5.6

2

0

0

9

7.4

7.1 6.4 5.0 5.6

4.4

4.0 5.0 5.6 

14 
Table 2-6: Summary of Knoxville Area Precipitation, 1999-2009 

Precipitation (inches) 

Year March April May June July August September October 

Seas

Tot

19

9

9

4.9 3.4

4.9 5.6 12.7

0.9

0.8 2.8 36.

2

0

0

0

4.4

6.7 5.9 3.4

6.1 1.4 3.8 0.1 31.

2

0

01 2.6

2.8 3.5 3.9

4.1 3.7 3.6

0.9

25.

2

0

0

2 10.6 1.4

4.7 3.9 5.7 1.4 5.2 5.6 38.

2

0

03 2.1 6.0 8.1 2.5 8.3 5.5 5.1 1.2 38.

2

0

0

4

4.6

2.7 5.4

7.9

7.6

2.2

4.8 3.1 38.

2

0

05 3.5 4.8 3.2 3.1 5.0 3.8 1.7 1.1 2

6.

2

0

0

6 3.2

7.6

2.1 2.4 3.9

6.4

6.2

4.1 35.

2

0

0

7

2.6 5.1 1.5 1.3 4.7

4.1 1.5 1.2

2

2.

2

0

08 4.3 3.7 3.4

2.2

7.0 1.9 3.2 1.7

2

7.

2

0

0

9 3.5 2.9 8.1 4.9

7.0

6.2

4.6

4.3 41.

15 
Table 2-7: 2002-2008 Knoxville Region Ozone Forecasting Results 

2002 2003 2004 

Overall Knoxville Great Smoky 

Mountains 

Knoxville Great Smoky 

Mountains 

Knoxville Great Smoky 

Mountains 

Kn

Forecast Accuracy/Color Code Accuracy 

66% 69% 73% 65% 74% 68% 7

Forecast Accuracy/Action/No Action 

83% 82% 95% 93% 99% 99% 9

False Alarm Rate 46% 27% 60% 71% 100% 33% 7Missed Action Days 1% 9% 3% 4% 1% 1% 

2006 2007 2008 

Overall Knoxville Great Smoky 

Mountains 

Knoxville Great Smoky 

Mountains 

Knoxville Grea

Mou

Forecast Accuracy/Color Code Accuracy 

73% 73% 77% 80% 78% 7

Forecast Accuracy/Action/No Action 

94% 93% 93% 92% 94% 9

False Alarm Rate 69% 80% 53% 63% 56% 5Missed Action Days 1% 2% 2% 3% 1% 

16 
17 

Table 2-8: Ozone Data Capture 2003-2008 (March 1 to October 31) 

County Site Name Monitor ID 

Avg. Valid Days 

Reported 

Avg. % D

Report

Anderson Freels Bend Study Area 470010101-1 240 96.7 

Look Rock, GSMNP 470090101-1 241 98.5 Blount Cades Cove, GSMNP 470090102-1 226 90.7 

Jefferson 1188 Lost Creek Road 470890002-1 241 98.2 

9315 Rutledge Pike 470930021-1 239 97.5 Knox 4625 Mildred Drive 470931020-1 233 94.8 

Loudon **130 Webb Drive/Roberts Rd. 471050108/0109 - 1 242 98.7 

Cove Mountain, GSMNP 47155101-1 238 97.2 Sevier *Clingman’s Dome, GSMNP 471550102-1 180 72.3 

Overall 231 93.8

* Monitoring site operated on shorter ozone schedule due to weather extremes. **2004 to 2008 data. 
Effect of Temperature

For any given day, ambient temperature is a key meteorological factor in ozone formation, and the 

temperature/ozone concentration relationship is a useful metric for assessing the effect of emission 

reductions on air quality. In Tennessee, most exceedances of the 8-hour ozone standard have 

occurred when the maximum daily temperature is 89 ̊ F or greater (Figure 2-6). 

Figure 2-6: Relationship of High Temperature Days 

and Ozone NAAQS Exceedances in the Knoxville Region 

y p

0

5

10

15

20

25

30

707172737475767778798081828384858687888990919293949596979899

10

0

Da i l y M a x Te mpe r a t ur e ( De g F)

N

u

m

b

er of E

x

ceed

a

nces at I

n

dic

ate

d

T

e

m

perat

ure

Table 2-9 shows the number of days above 89° F and the number of exceedances measured during 

each ozone season from 1999 to 2009. For each day over 89 ̊ F, the average number of exceedances 

declined from 1.25 in 1999 to 0.22 in 2006, increased slightly in 2007, and declined to new lows of 

0.09 and 0.00, respectively, in 2008 and 2009. These data are shown as a scatter plot in Figure 2-7, 

and a correlation coefficient is calculated to assess the relationship between the variables9

. Similar 

correlations are observed when the number of ozone exceedances is plotted against the average daily

maximum temperature (Figure 2-8). Although fewer exceedances are observed during cool 

summers, the data indicate that the number of monitored exceedances remained low in 2006 and 

2008, despite the relatively hot weather (this trend is plotted relative to a baseline year 1999 in 

 

9 The scatter plots used in this section plot the number of ozone exceedances for a given year against various 

independent variables (emissions, temperature, precipitation, and wind speed), and a correlation coefficient (R2

) is 

calculated to estimate the degree of linearity between the two variables. A correlation coefficient of 1.0 indicates a 

perfect linear relationship between the independent and dependent variables, and a correlation coefficient of zero 

indicates that there is no linear relationship. For all scatter plots shown in this document, a higher correlation coefficient

indicates that ambient ozone concentrations are more strongly affected by a given independent variable. However, since 

ambient ozone concentrations are affected by all of these variables (emissions, temperature, precipitation, and wind 

speed), we would not expect to observe a perfect linear relationship of ambient ozone with any single variable. The 

correlations shown on these plots may also be decreased because for a given year, the total number of ozone exceedances 

is shown, rather than the number of exceedances for specific months. 

18 
Figure 2-9). The data demonstrate that declining ozone concentrations are attributable to real 

emission reductions, rather than year-to-year temperature variations, in the Knoxville region and 

across the State of Tennessee. 

Table 2-9: Relationship of Temperature and Ozone Exceedances by Year 

Year Number of Days 

Above 89° F 

Number of NAAQS 

Exceedances 

Average 

Exceedances/Day 

1999 51 64 1.25

2000 47 36 0.77

2001 49 19 0.39

2002 77 47 0.61

2003 32 14 0.44

2004 25 3 0.12

2005 61 18 0.30

2006 65 14 0.22

2007 81 29 0.36

2008 66 6 0.09

2009 24 0 0.00

Figure 2-7: Scatter Plot of Temperature and Ozone Exceedances, 1999-2009 

19 
Figure 2-8: July/August Mean Daily Maximum Temperature and Ozone Exceedances, 

1999-2009 

20 
Figure 2-9: Comparison of Temperature and Ozone Exceedances with 1999 Baseline 

-110.0%

-90.0%

-70.0%

-50.0%

-30.0%

-10.0%

10.0%

30.0%

50.0%

70.0%

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

% Change from

Baseline Year (1999)

Days Above 89 Deg. F Avg. Exceedances/Day Baseline (1999)

Effect of Precipitation and Wind Movement

Elevated ozone concentrations in the Knoxville area are affected by precipitation, especially during

the months of July and August. Scatter plots comparing ozone exceedances with precipitation 

(Figure 2-10) indicate that elevated ozone concentrations are more likely to be observed during 

periods of low precipitation. A plot of wind speed against exceedances (Figure 2-11) indicates 

conflicting trends for July and August, in which higher July wind speeds are associated with fewer 

exceedances, while August wind speeds are correlated with a higher number of exceedances. 

21 
Figure 2-10: July/August Precipitation10 and Ozone Exceedances, 1999-2009 

 

10 July 1999 precipitation data was omitted from this chart due to an unusually large rain event. 

22 
Figure 2-11: July/August Wind Speed and Ozone Exceedances, 1999-2009 

NOX and VOC Emission Trends 1996-2007

Figure 2-9 illustrates the overall downward trend in ozone exceedances. This downward trend is 

primarily due to decreased emissions of nitrogen oxides and volatile organic compounds throughout 

the region. These emission trends are shown for the period 1996-2007 in Table 2-10 and Figure 2-

12. In general, these data indicate declining NOX and VOC emissions during this period. The 

exception to this trend is the year 2002, during which NOX emissions increased by over 12,000 

tons/year. 

This anomaly is explained by Tennessee’s efforts to improve the quality of the State’s emission 

23 
inventory as part of the Early Action Compact (EAC) process. As a result of this work, the emission 

inventory for 2002 was more complete and accurate than had been available for previous years. 

Improvements in the quality of emissions data were observed in all sectors of the inventory, with the

most significant improvements observed in the Mobile sector. The improvements to the emission 

inventory allowed Tennessee to provide more accurate MOBILE Model inputs (e.g., vehicle 

distribution profiles) to the regional modeling effort. 

A detailed examination of the emission inventories for 1999 and 2002 indicates that essentially all of 

the emissions increase over this period can be attributed to the Mobile sector. However, the reported 

“increase” should be considered a one-time correction, which resulted from a more accurate 

characterization of emissions. The emission inventory for 2005 indicates that NOX emissions are 

continuing to trend downward. It is expected that this trend will continue in subsequent emission 

inventory cycles. 

Table 2-10 and Figure 2-12 also show the trends in eight-hour ozone concentrations across the 

Knoxville region. The data show that peak and average ozone concentrations have declined since 

1999, with greater decreases between 2002 and 2005. This trend did not hold for 2007, as discussed 

on following pages. 

Table 2-10: Summary of Emissions and 8-Hour Ozone Concentrations, 1996-2007 

Year 

NOX

Emissions 

(tons/year)A

VOC 

Emissions 

(tons/year)A

4th Highest 8-hr Max, 

Highest Observed for 

Any Single Monitor 

(ppm)B

4th Highest 8-hr 

Max, Average of 

all Monitors 

(ppm)B

1996 64,500 59,287 0.098 0.088

1999 61,094 58,623 0.106 0.099

2002 73,222 55,110 0.103 0.097

2005 55,981 50,154 0.086 0.08

2007 49,382 41,018 0.092 0.085

Notes to Table 2-7: 

Data Sources: 1996 & 1999 - EPA's AirData Website; 2002 - EPA Final 2002 NEI; 2005 - TN and Knox County 2005 Emission Inventory; 2007 – 

TN and Knox County 2007 Emission Inventory 

A. NOX and VOC emissions indicated above are the total emissions in tons per year for all counties in the Knoxville ozone 

nonattainment area (Knoxville and surrounding counties). NOX and VOC emissions include point, area, onroad mobile, and 

nonroad mobile source categories.

B. Monitoring data includes all monitors in the Knoxville ozone nonattainment area (Knoxville and surrounding counties). 

24 
Figure 2-12: Emission and 8-Hour Ozone Trends, 1996-2007 

When VOC and NOX emissions from Table 2-7 are plotted against the number of ozone exceedances 

in corresponding years, a strong correlation is observed for both pollutants (Figure 2-13). Although 

ambient ozone appears to be more strongly correlated with VOC than NOX in these graphs, the 

difference appears to result from the one-time correction in NOX emissions for 2002. When 1999 

data are omitted (Figure 2-14) ambient ozone concentrations are more strongly correlated with NOX

emissions than any other variable.

Summary: Influence of Meteorology and Emissions

Based on the available data and the scatter plots presented in this section, ambient ozone 

concentrations in the Knoxville area are most strongly affected by NOX and VOC emissions, with 

temperature, precipitation, and wind speed playing an important secondary role. 

25 
Figure 2-13: Scatter Plots of Emissions and Ozone Exceedances 

26 
Figure 2-14: Scatter Plot of NOX Emissions and Ozone Exceedances 

(1999 Data Omitted) 

2007 Ozone Season

As indicated above, the trend of declining ozone concentrations did not hold true for the Knoxville 

area during the 2007 ozone season. Ozone concentrations increased during 2007 both at the national 

level (Figure 2-15) and for multiple States in the southeast. Substantial increases11 in monitored 

ozone levels, measured as the average value for all monitors, were noted in Kentucky, North 

Carolina, Tennessee, and Alabama (Table 2-11). In two additional States, Florida and South 

Carolina, year-to-year increases in ozone concentrations of at least 10% were observed at one or 

more monitors between 2006 and 2007 (Table 2-12). Higher ozone concentrations in 2007 resulted 

in part from unusually hot, dry weather across the region (Figure 2-16)12, and the wildfires that 

occurred across southern Georgia and northern Florida between May and June (Figure 2-13) may 

have contributed to higher ozone concentrations across the region. 

 

11 Measured as the year-to-year change from 2006 to 2007. 

12 EPA uses a statistical model to account for the weather-related variability of seasonal ozone concentrations to provide 

a more accurate assessment of the underlying trend in the precursor emissions that cause ozone. Figure 2-14 shows 8-

hour ozone concentrations for the 1997-2008 ozone seasons, including the trend in observed values at monitoring sites, 

and the underlying ozone trend after removing the effects of weather. The adjusted trend represents ozone levels 

anticipated under typical weather conditions and serves as a more accurate ozone trend for assessing changes in 

emissions. Adapted from U. S. EPA, “Trends in Ozone Adjusted for Weather Conditions” 

 (http://www.epa.gov/airtrends/weather.html). 

27 
Figure 2-15: National Ozone Trends, 2004 – 2008 

Table 2-11: Region 4 Ozone Summary, Average of All Monitors 

 4th Max, Average of All Monitors % Change 

State 2006 2007 2008 2006-2007 2006-2008 

Alabama 0.079 0.082 0.072 3.8% -12.2% 

Florida 0.075 0.072 0.070 -4.0% -2.78% 

Georgia 0.084 0.084 0.076 0.0% -9.5%

Kentucky 0.072 0.080 0.070 11.1% -12.5%

Mississippi 0.080 0.076 0.070 -5.0% -7.9%

North Carolina 0.076 0.081 0.077 6.6% -4.9%

South Carolina 0.075 0.075 0.075 0.0% 0.0% 

Tennessee 0.081 0.084 0.075 3.7% -10.7%

28 
Table 2-12: Region 4 Ozone Summary, Individual Monitors 

 4th Max, Highest Monitored Value for 

any Single Monitor (see Note) 

Highest Year-to-Year 

Change for any Single 

Monitor (see Note) 

State 2006 2007 2008 2006-2007 2006-2008 

Alabama 0.089 0.095 0.082 11.1% 1.3%

Florida 0.083 0.083 0.082 18.6% 5.6%

Georgia 0.099 0.102 0.089 9.6% 2.7%

Kentucky 0.083 0.089 0.077 25.4% 12.7%

Mississippi 0.087 0.084 0.078 -2.5% -7.1%

North Carolina 0.093 0.096 0.093 13.4% 14.9% 

South Carolina 0.085 0.084 0.085 16.9% 10.8% 

Tennessee 0.088 0.092 0.086 20.3% 2.6%

Note: The highest monitored value may occur at different ozone monitors within the multi-year period. The highest year-to-year change 

for a single monitor does not necessarily occur at the location with the highest-monitored ozone concentration.

Figure 2-16: Seasonal Ozone Concentrations Adjusted for Weather 

29 
Figure 2-17: 2007 Georgia Wildfires 

Photo of smoke Shaded graphic of plume 

30 
3.0 PERMANENT AND ENFORCEABLE REDUCTIONS 

Measured reductions in the ozone National Ambient Air Quality Standards (NAAQS) in the 

Knoxville MSA are largely attributable to permanent and enforceable reductions from emission 

sources. These reductions, reflected in part by the emissions inventories, are attributable to both 

federal and state measures. The significant permanent and enforceable measures implemented 

around the region will continue to lower emissions levels in the region. Additionally, new emissions

control programs for fuels and motor vehicles will help to ensure a continued decrease in emissions 

throughout the region. 

Federal Measures

NOX Budget Trading Program and Clean Air Interstate Rule

Emissions reductions from the Tennessee Valley Authority’s Bull Run and Kingston Fossil Plants, 

located in Anderson and Roane Counties, respectively, have contributed to the region’s reduction in 

emissions and significant improvement in air quality13. The emissions reductions at these facilities 

result from Tennessee’s implementation of the emissions budgets specified in the NOX Budget 

Trading Program, beginning with the 2004 ozone season, and ending with the 2008 ozone season, 

when the NOX Budget Trading Program was superseded by the Clean Air Interstate Rule (CAIR). 

EPA’s Clean Air Interstate Rule (CAIR)14, 15 updated and expanded the NOX Budget Trading 

Program, and requires additional NOX reductions in 2009 and beyond. CAIR NOX ozone season 

budgets are shown in Table 3-116. Under CAIR, the NOX emission budgets of these States were 

reduced by an average of 13.9% in 2009. The additional NOX reductions required by CAIR are 

expected to aid in the maintenance of the 8-hour ozone NAAQS in the Knoxville MSA, and may 

result in additional reductions in ozone concentrations. 

 

13 It is likely that ozone concentrations in the Knoxville MSA are affected by multiple electricity generating units in 

Tennessee and the surrounding States. However, TVA’s Bull Run and Kingston facilities are located in close proximity

to Knoxville, and it is expected that emissions reductions from these two facilities would have the most immediate and 

noticeable effects on ozone concentrations in the area around Knoxville. 

14 CAIR was remanded to EPA for further rulemaking by the U. S. Court of Appeals for the District of Columbia Circuit 

on December 23, 2008, and EPA is currently working to promulgate a CAIR replacement rule. Tennessee expects the 

replacement rule to be at least as stringent as CAIR, and does not expand the remand and replacement of CAIR to 

substantially alter the analysis presented here. 

15 Due to the remand of the Clean Air Interstate Rule (CAIR) NOX Ozone Season Trading Program and other CAIR 

rules, there have been questions regarding whether or not CAIR constitutes a “permanent and enforceable” measure for 

ozone attainment. Tennessee notes that, while CAIR will ultimately be replaced by a new Federal transport rule, the 

NOX reductions established under the NOX SIP Call remain in effect and are “permanent and enforceable”, regardless of 

whether the NOX Budget Trading Program, CAIR, or other applicable requirements are used to attain those reductions. 

16 For clarity, Table 3- 4 shows the same States that were designated in 1998 (Federal Register, Vol. 63, No. 207, 

October 27, 1998, p 57395, Table II-6) as contributing significantly to ozone nonattainment in Tennessee. Following the 

implementation of the NOX Budget Trading Program, some of these States may no longer contribute significantly to 

ozone nonattainment in Tennessee. 

31 
Table 3-1: Comparison of Emission Budgets for NOX SIP Call 

and CAIR Ozone Season NOX Trading Program 

State 

2005 NOX

Budget – NOX

Budget Trading 

Program (tons) 

CAIR Ozone 

Season NOX

Budget for 2009-

2014 (tons) 

2009 CAIR 

Budget, % 

Reduction from 

2005 NOX

Budget 

CAIR Ozone 

Season NOX

Budget for 2015 

and Beyond 

(tons) 

2015 CAIR 

Budget, % 

Reduction from 

2005 NOX

Budget 

Alabama 25,497 32,182 -26.2% 26,818 -5.2%

Delaware 5,227 2,226 57.4% 1,855 64.5%

District of Columbia 233 112 51.9% 94 59.7% 

Illinois 35,557 30,701 13.7% 28,981 18.5%

Indiana 55,729 45,952 17.5% 39,273 29.5%

Kentucky 36,224 36,045 0.5% 30,587 15.6%

Maryland 15,466 12,834 17.0% 10,695 30.8%

Michigan 31,247 28,971 7.3% 24,142 22.7%

North Carolina 41,547 28,392 31.7% 23,660 43.1% 

Ohio 49,499 45,664 7.7% 39,945 19.3%

Pennsylvania 50,843 42,171 17.1% 35,143 30.9%

South Carolina 19,678 15,249 22.5% 12,707 35.4% 

Tennessee 31,333 22,842 27.1% 19,035 39.2%

Virginia 21,195 15,994 24.5% 13,328 37.1%

West Virginia 29,043 26,859 7.5% 26,525 8.7% 

Totals 448,318 386,194 N/A 332,788 N/A

Reduction from 2005 NOX SIP Call to 2009 CAIR: 13.9% 

Reduction from 2005 NOX SIP Call to 2015 CAIR: 25.8% 

Data source for CAIR budgets: Federal Register, Vol. 70, No. 91, May 12, 2005, pp 25162-25405. See table V-4, page 

25233.

TVA’s Bull Run Fossil Plant is a single-generator coal-fired power plant located in Anderson 

County near Oak Ridge. TVA’s Kingston Fossil Plant consists of nine coal-fired boilers and is 

located on Watts Bar Reservoir in Roane County. TVA began operating selective catalytic reduction 

(SCR) control units in 2004 at Bull Run and at eight of nine boilers at Kingston. TVA began 

operation of an SCR at Kingston’s Unit 9 in 2006. 

Table 3-2 and Table 3-3 show the NOX emissions at Bull Run and Kingston fossil plants, as 

determined by monitoring data submitted to EPA for NOX Budget Trading Program compliance. As 

these tables indicate, emissions have declined significantly for both facilities. Between 2003 and 

200817, emissions at Bull Run declined from 7,416 tons to 1,087 tons (85% reduction). Similar 

 

17 Final 2009 emissions data from EPA’s Clean Air Markets Division (CAMD) were not available as of April 20, 2010. 

The preliminary 2009 data were not included because substantial changes in preliminary and final numbers have been 

noted in previous years. 

32 
reductions were observed at the Kingston Fossil Plant, where emissions declined by 90% during the 

same period. The average NOX emission rate at each facility (pounds of NOX emitted per million 

Btu of heat input) also declined, indicating that the emissions reduction generally did not result from

reduced heat input at either source. The NOX emissions reductions at the Bull Run and Kingston 

Fossil Plants will contribute to decreased ozone pollution throughout the region, and continued 

maintenance of the 8-hour ozone standard in the Knoxville MSA. 

Table 3-2: Bull Run Fossil Plant NOX Emission Reductions 

Under the NOX Budget Trading Program and CAIR NOX Ozone Season Trading Program 

Ozone Season Heat Input (MMBtu) NOX Emissions (tons)

Avg. NOX Emission 

Rate (lb/MMBtu) 

2003 25,874,627 7,416 0.57

2004 23,481,627 1,462 0.12

2005 29,773,981 927 0.06

2006 21,737,416 686 0.06

2007 29,497,599 1,008 0.07

2008 23,779,279 1,087 0.09

Data Source: EPA Clean Air Markets website, NOX SIP Call emissions data and compliance reports (and Clean Air 

Markets Data and Maps (http://camddataandmaps.epa.gov/gdm/). 

Table 3-3: Kingston Fossil Plant NOX Emission Reductions 

Under the NOX Budget Trading Program and CAIR NOX Ozone Season Trading Program 

Ozone Season Heat Input (MMBtu)

NOX Emissions 

(tons) 

Avg. NOX Emission Rate 

(lb/MMBtu) 

2003 45,745,007 11,327 0.50

2004 43,261,864 3,855 0.18

2005 44,360,986 2,070 0.09

2006 47,620,787 1,155 0.049

2007 47,920,325 1,196 0.05

2008 45,942,444 1,153 0.05

Data Source: EPA Clean Air Markets website, NOX SIP Call emissions data and compliance reports () and Clean 

Air Markets Data and Maps (http://camddataandmaps.epa.gov/gdm/). 

NOX Reductions in Upwind States 

EPA’s “Finding of Significant Contribution and Rulemaking for Certain States in the Ozone 

Transport Assessment Group Region for Purposes of Reducing Regional Transport of Ozone” (NOX

SIP Call)18 indicated that Tennessee’s 8-hour ozone nonattainment areas received significant 

 

18 Federal Register Volume 63, No. 207, Tuesday, October 27, 1998, 57356 – 57538. 

33 
contributions from several upwind States19. Tennessee expects that NOX emission reductions from

neighboring states will contribute to attainment of the 8-hour ozone standard (Table 3-4). 

Table 3-4 indicates that most NOX Budget States have made significant emission reductions between 

2000 and 2008. For the States that EPA listed as contributing significantly to ozone nonattainment 

in Tennessee, EPA’s 2008 report on the NOX Budget Trading Program20 indicates that emissions 

have been reduced by 645,265 tons, for an average reduction of 60.8%. 

Table 3-4: NOX Budget Trading Program – Regional Reductions 

Statewide NOX Reductions from 2000-2008 (Ranked by % Reduction) 

Ozone Season NOX Emissions (tons)

State 2000 2005 2008 

% Reduction from 

2000 - 2008

DC 109,198 30,401 27,089 75.2%

DE 69,641 25,718 21,711 68.8%

MD 159,578 54,335 54,644 65.8%

MO 84,560 33,632 30,221 64.3%

SC 28,954 20,989 10,667 63.2%

VA 73,082 32,888 27,105 62.9%

TN 34,058 18,809 12,777 62.5%

WV 101,601 36,730 39,386 61.2%

NC 145,722 57,249 57,838 60.3%

AL 80,425 42,157 34,358 57.3%

IL 39,674 18,193 17,552 55.8%

MI 40,043 22,309 19,596 51.1%

KY 288 253 161 44.1%

OH 87,329 51,125 56,747 35.0%

PA 5,256 6,538 4,285 18.5%

IN 134 279 133 0.7%

All States 1,059,543 451,605 414,270 52.9% 

Notes to Table 3-4:

1. Data Source: EPA report, The NOX Budget Trading Program: 2008 Highlights. Available online at EPA Clean Air Markets website 

(http://www.epa.gov/airmarkets/progress/NBP_4.html). 

Onroad Mobile Sources 

A significant amount of pollution is expected to be reduced from onroad mobile sources (mobile 

sources). Federal requirements for cleaner cars and trucks, and cleaner fuels, have contributed to 

 

19 These States included Alabama, District of Columbia, Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, 

Michigan, Missouri, North Carolina, Ohio, Pennsylvania, South Carolina, Virginia, West Virginia, and Wisconsin. 

Wisconsin was later removed from the list of States subject to the NOX SIP Call, and is not required to participate in the 

NOX Budget Trading Program. Missouri became subject to the NOX Budget Trading Program in 2007. 

20 NOX Budget Trading Program: 2005 Compliance and Environmental Results. Available online at EPA Clean Air 

Markets website (http://www.epa.gov/airmarkt/progress/docs/2005-NBP-Compliance-Report.pdf). 

34 
substantial decreases in emissions from these sources. Federal standards for National Low Emission 

Vehicles (NLEV) began in 1999, and implemented through 2001 for new light duty cars and trucks. 

Tier 2 vehicle standards began in 2004 and will result in additional reductions from the passenger 

vehicle fleet. As the fleet of vehicles nationally, and in the Knoxville area, is replaced with newer 

and cleaner vehicles, the emissions from these vehicles should reduce on a grams per mile basis. 

 

New federal emissions standards for onroad heavy-duty diesel engines and vehicles, beginning in 

2004, will contribute significantly to reductions in NOx and VOC emissions from diesel powered 

vehicles. Additionally, the effects of other national programs, like the new standards for gasoline 

and diesel fuel sulfur content, will also contribute to decreased emissions. EPA’s programs for 

onroad heavy-duty diesel engines is expected to result in NOx and particulate matter reductions of 

around 90%. 

 

Non-road Mobile Sources 

A variety of Federal non-road mobile source emissions reduction initiatives will result in reduced 

emissions from non-road sources. A wide variety of equipment will be affected by these regulations,

including lawnmowers and garden equipment, farm equipment and construction equipment. 

In 1994, EPA adopted the first set of emission standards (Tier 1) for all new nonroad diesel engines 

greater than 37 kilowatts (50 horsepower), except those used in locomotives and marine vessels. 

EPA also phased in more stringent “Tier 2” emission standards from 2001 to 2006 for all engine 

sizes and added more stringent “Tier 3” standards for engines between 37 and 560 kW (50 and 750 

horsepower) from 2006 to 2008. The EPA estimates these standards will further reduce nonroad 

diesel engine emissions by 60% for NOx and 40% for particulate matter from the 1994 Tier 1 

emission levels21. 

 

In addition to controls on nonroad diesel engines, EPA is phasing in a set of controls for nonroad 

spark ignition engines. Starting in 2007, manufacturers were required to meet more stringent 

standards which will result in a 90% reduction in NOx, HC, and CO emissions22. Additional controls 

will reduce evaporative hydrocarbon emissions from gasoline fuel tanks.

State and Local Measures

The following measures have been implemented at the State and local level and are expected to 

contribute to the reduction of ground-level ozone in the Knoxville nonattainment area. With the 

exception of Stage I vapor recovery, the measures listed below were not accounted for in the 

emissions inventory. 

Stage I Vapor Recovery 

Tennessee has promulgated rules for Stage I Gasoline Vapor Recovery for several counties 

 

21 U. S. EPA. Program Update Reducing Air Pollution from Nonroad Engines. April 2003. US EPA EPA420-F-03-011. 

22 Ibid.

35 
throughout Tennessee, including Anderson, Blount, Jefferson, Knox, Loudon, and Sevier Counties. 

Gasoline dispensing stations in these counties that were existing sources on December 29, 2004, 

were required to comply with this rule by May 1, 2006. 

Onroad Mobile Sources 

 

Effective in 2005, the Tennessee Air Pollution Control Board promulgated a statewide motor vehicle 

anti-tampering rule. This rule, defined in Chapter 1200-3-36, Motor Vehicle Tampering, was 

promulgated to reduce the air pollution caused by tampering with a motor vehicle’s emissions 

control system. The area of applicability for this rule is statewide. Chapter 1200-3-36 defines 

tampering as modifying, removing or rendering inoperative any air pollution emission control 

device, which results in an increase in emissions beyond established federal motor vehicle standards. 

Additionally, the rule identifies what is specifically prohibited (example: removing a catalytic 

converter). 

Air Quality Alert Programs in the Knoxville Region 

With respect to ozone, air quality alerts are typically called on hot, muggy days with little wind, 

when ground-level ozone concentrations are predicted to approach unhealthy levels and the ozone 

NAAQS could be exceeded23. Once the air quality forecast is issued, the media is able to release 

these alerts in a timely fashion, and air quality alert days are announced to the public through 

television and radio. Citizens can also receive e-mail notification of air quality alerts via 

EnviroFlash and AirNOW. Many businesses subscribe to the alerts and conduct their own activities 

within their individual structures. 

Smart Boards located on Knoxville interstates have been used to notify drivers of program

recommendations on air quality alert days. Efforts are underway to continue the use of this medium

for 2010, in conjunction with the State’s TDOT 511 information program. Knoxville Area Transit 

(KAT) offers free bus rides on alert days, and senior citizens may ride the buses year-round for no 

charge. The Knoxville region has a nationally recognized Smart Trips program in effect in 

Anderson, Blount and Knox counties. 

 

23 http://www.epa.gov/reg3artd/airquality/actdays.htm. 

36 
4.0 MAINTENANCE DEMONSTRATION AND EMISSION INVENTORY 

An emission inventory was prepared to estimate base year (2007) NOX and VOC emissions in the 

Knoxville nonattainment area, with emissions projections for the years 2010, 2013, 2016, 2020 and 

2024 (Attachment A). This emission inventory includes all anthropogenic VOC and NOX sources 

for Anderson, Blount, Jefferson, Loudon, Knox, and Sevier Counties. The portion of the 

nonattainment area located in Cocke County is within the boundaries of the Great Smoky Mountains 

National Park. With the exception of onroad sources, emissions in the Cocke County portion of the 

nonattainment area are insignificant. Further discussion of Cocke County emissions is included in 

Appendix G of Attachment A. 

An attainment year inventory can be developed for any of the three years in which an attaining 

design value is computed. For the Knoxville nonattainment area, 2007 was chosen as the attainment 

year inventory. Use of 2007 as the attainment year is believed to be representative of the emissions 

during the attainment period. 

Point Sources

The State of Tennessee’s 2007 emissions inventory, prepared by the Division of Air Pollution 

Control and Knox County Division of Air Quality Management, was used as a source of base year 

emissions for Anderson, Blount, Jefferson, Loudon, Knox, and Sevier Counties. NOX and VOC 

emissions were calculated for a typical summer July day, taking into account the seasonal 

adjustment factor for summer operations of facilities. 

An information request was sent via e-mail to the designated company contact. A typical request 

included required pollutants, division rule to furnish information, and contact information. Each 

facility was required to update the previous Emission Database Layout (EDL) file with information 

for the requested year24 and return the updated EDL to the APC emission inventory mailbox. For 

this redesignation request, point source emissions were obtained from the EDL for companies in the 

desired counties. 

Future-year emissions were projected for 2010, 2013, 2016, 2020, and 2024, using 2007 emissions 

and economic growth factors from EPA’s Economic Growth and Analysis System (EGAS 5.0). 

Growth factors were determined using the Default REMI 5.5 SCC Configuration and user-selected 

base and future years25. Growth factors were obtained from EGAS 5.0, and multiplied by the 2007 

emission values to calculate emissions for future years. The Knox County Health Department, Air 

Quality Management Division, provided local data for Knox County. The point source inventory for 

five counties (Anderson, Blount, Jefferson, Knox, and Loudon) shows that 2007 NOX emissions 

 

24 The Emission Database Layout file includes emissions units, emission release points, emission process and period, 

and emissions control equipment. 

25 The Default REMI 5.5 SCC Configuration allows the calculation of future emission factors based on Source 

Classification Category (SCC). The EGAS 5.0 provides economic growth factors by industry type on a statewide basis 

(not on county basis). It allows the user to enter the base year and select future years for which economic growth factors 

are needed. The model outputs growth factors based on economic growth projections by industry by SCC source 

classification codes. 

37 
equaled 42.69 tons/day, for a typical July day (Table 4-1). The highest NOX emissions were 

observed in Anderson County, with 34.46 tons/day in 2007. Point source NOX emissions in this 

county are expected to grow to 45.11 tons/day by 2024 (1.8% increase). 

Table 4-1: Point Source NOX Emissions for a Typical Summer Day 

NOx, Typical Summer Day with SAF, July, (ton/day) 

County 2007 2010 2013 2016 2020 2024

Anderson 34.46 34.48 34.52 34.64 34.69 34.79

Blount 0.85 0.83 0.83 0.90 0.98 1.06

Jefferson 0.00 0.00 0.00 0.00 0.00 0.00

Knox 5.45 5.38 5.58 5.96 6.50 7.07

Loudon 1.90 1.93 1.98 2.03 2.09 2.15

Sevier 0.03 0.03 0.03 0.03 0.04 0.04

Total Emissions 42.69 42.65 42.94 43.56 44.30 45.11

 % Change in Emissions 

from 2007 -0.1% 0.59% 2.1% 3.2% 3.6%

Total VOC emissions from point sources were 7.32 tons/day in 2007 (Table 4-2). Blount County 

was the largest point source emitter, with 2.43 tons/day of VOC emissions. VOC emissions for the 

five counties are projected to increase to 9.53 tons/day in 2024 (30% increase). 

Table 4-2: Point Source VOC Emissions for a Typical Summer Day 

VOC, Typical Summer Day with SAF, July, (ton/day) 

County 2007 2010 2013 2016 2020 2024 

Anderson 0.63 0.66 0.68 0.72 0.83 0.96

Blount 2.43 2.06 2.05 2.22 2.46 2.75

Jefferson 0.01 0.01 0.01 0.01 0.01 0.02

Knox 2.13 2.21 2.29 2.47 2.74 3.04

Loudon 2.12 2.23 2.34 2.46 2.60 2.76

Sevier 0.001 0.001 0.002 0.002 0.002 0.002

Total Emissions 7.32 7.17 7.37 7.88 8.64 9.53

 % Change in Emissions 

from 2007 -2.0% 0.7% 7.7% 18.0% 30.2%

The top five NOX emission sources (Table 4-3) account for 40.91 tons/day (95.8%) of total NOX

emissions. TVA Bull Run Fossil Plant in Anderson County is the largest single emitter of NOx with 

32.7 tons/day (76.5%), followed by Cemex, Inc., of Knox County with 10.8% of total NOX

emissions in the region (4.61 tons/day). 

38 
Table 4-3: Top Five NOX Sources in 2007 

Facility Name County 

2007 NOX Emissions 

(tons/day) 

% of Total NOX 

Emissions 

TVA Bull Run Anderson 32.69 76.5% 

CEMEX Knox 4.61 10.8%

Tate & Lyle Loudon 1.56 3.7% 

DOE Y-12 Anderson 1.47 3.4% 

ALCOA - South Plant Blount 0.58 1.4% 

The top five VOC sources (Table 4-4) contributed 4.89 tons/day (66.7%) of point source VOC in 

2007. The largest single VOC source is Tate & Lyle in Loudon County (1.83 tons/day). 

Table 4-4: Top Five VOC Sources in 2007 

Facility Name County 

2007 VOC 

Emissions (tons/day) 

% of Total VOC 

Emissions 

Tate & Lyle Loudon 1.83 25.0% 

ALCOA - North Plant Blount 1.31 17.8% 

Sea Ray Island River Dr Knox 0.68 9.3% 

USI, INC Blount 0.57 7.8% 

Republic Plastics Knox 0.50 6.8% 

Area Sources

The area source emission inventory was developed using EPA Nonpoint files located on EPA’s 

CHIEF Emission Inventory website for the 2008 NEI and from the documentation for the Final 2002 

Nonpoint Sector (February 2006 version) National Emission Inventory for Criteria and Hazardous 

Air Pollutants26. Area source emission estimates were developed for 56 different source 

classification codes (SCC). Area source emissions for Knox County were provided by the Knox 

County Department of Health, Air Quality Management Division. Annual emission estimates were 

adjusted as necessary to estimate tons/day emissions for July. 

Future-year emissions were projected for 2010, 2013, 2016, 2020, and 2024, using 2007 emissions 

and EGAS 5.0 growth factors. Growth factors obtained from EGAS 5.0 were multiplied by the 2007 

emission values to calculate emissions for future years. Table 4-5 and Table 4-6 show the total area 

source NOX and VOC emissions for the selected years between 2007 and 2024 in July. NOX 

emissions are expected to increase by 30% by 2024, while VOC emissions are expected to increase 

by 21% by 2024. 

 

26 See Appendix C of Attachment A for additional information. 

39 
Table 4-5: Area Source NOX Emissions

NOx, Typical Summer Day with SAF, July, (ton/day) 

County 2007 2010 2013 2016 2020 2024 

Anderson 0.46 0.48 0.50 0.52 0.54 0.57

Blount 0.30 0.30 0.31 0.32 0.33 0.35

Jefferson 0.23 0.24 0.24 0.25 0.26 0.28

Knox 0.65 0.68 0.77 0.93 0.96 0.95

Loudon 0.22 0.23 0.24 0.24 0.26 0.27

Sevier 0.21 0.22 0.23 0.24 0.25 0.26

Total Emissions 2.07 2.15 2.29 2.50 2.60 2.68

 % Change in 

Emissions from 2007 3.9% 10.6% 20.8% 25.6% 29.5%

Table 4-6: Area Source VOC Emissions 

VOC, Typical Summer Day with SAF, July, (ton/day) 

County 2007 2010 2013 2016 2020 2024 

Anderson 3.83 3.94 4.06 4.21 4.39 4.58

Blount 6.50 6.65 6.87 7.15 7.51 7.89

Jefferson 3.65 3.74 3.83 3.99 4.19 4.39

Knox 12.57 12.91 13.27 13.90 14.71 15.56

Loudon 2.55 2.66 2.75 2.84 2.94 3.05

Sevier 4.15 4.31 4.45 4.55 4.66 4.77

Total Emissions 33.25 34.21 35.23 36.64 38.40 40.24

 % Change in 

Emissions from 2007 2.9% 5.9% 10.2% 15.5% 21.0%

Onroad Mobile Sources

Onroad Mobile source emissions were projected using a combination of output from computer 

programs that predict mobile emission factors and traffic volumes. These traffic volume projections 

and emission factors are discussed in more detail in Appendix D. 

The daily vehicle miles traveled (DVMT) projections, based on data provided by the Knoxville 

Transportation Planning Organization (TPO), are presented in Table 4-7. Further discussion is 

included in Appendix D. The 2007 DVMT were determined from traffic counts made by the 

Tennessee Department of Transportation. The DVMT for 2014 and 2024 were determined from a 

travel demand model, with linear interpolation used for the years not projected by the travel demand 

model (2010, 2013, 2016 and 2020). Future vehicle activity for the nonattainment area of Cocke 

County is described in Appendix G. 

Detailed information on MOBILE6.2 inputs are contained in Appendix D. The MOBILE6.2 input 

40 
and output files are included in Appendix H. Onroad emissions totals by county are summarized in 

Tables 4-8 and 4-9. Discussion on the development of onroad emissions for Cocke County are 

contained in Appendix G. Tables 4-8 and 4-9 illustrate significant reductions in NOx and VOC 

emissions from onroad mobile sources projected to occur between 2007 and 2024. 

Between 2007 and 2024 onroad emissions of Oxides of Nitrogen (NOx) are projected to decrease 

approximately 69%. Onroad emissions of NOx in 2007 are 71.83 tons/day, which decrease over time 

to 22.29 tons/day in 2024. Similarly, substantial reductions in Volatile Organic Compounds (VOCs) 

are projected to occur between 2007 and 2024. VOCs are expected to decrease from onroad motor 

vehicles from 36.77 tons/day in 2007 to 18.39 tons/day in 2024. This substantial reduction in oxides 

of nitrogen (NOx) is largely attributable to the Environmental Protection Agency’s (EPA) Federal 

Motor Vehicle Control Program. 

Table 4-7: Seasonally Adjusted Summer Daily Vehicle Miles Traveled 

Year 2007 2010 2013 2014 2016 2020 2024 

County Daily Vehicle Miles Traveled1, 2

Anderson 2,382,982 2,521,316 2,659,649 2,705,760 2,789,674 2,957,503 3,125,332

Blount 3,099,644 3,458,761 3,817,879 3,937,585 4,152,278 4,581,665 5,011,051

Cocke3 17,538 18,970 20,403 20,880 21,718 23,395 25,072

Jefferson 2,428,378 2,590,626 2,752,873 2,806,956 2,921,987 3,152,050 3,382,113

Knox 14,640,148 15,582,752 16,525,356 16,839,557 17,323,544 18,291,519 19,259,493

Loudon 2,353,782 2,505,623 2,657,464 2,708,078 2,767,226 2,885,523 3,003,819

Sevier 3,540,719 3,715,372 3,890,024 3,948,242 4,108,906 4,430,235 4,751,564

Total 28,463,191 30,393,420 32,323,648 32,967,058 34,085,333 36,321,890 38,558,444 

1 Data for 2007 is TDOT HPMS Data; that for 2014 and 2024 was produced by the Knoxville TPO’s Travel Demand Model (except Cocke County).

2 DVMT for 2010, 2013, 2016, and 2020 are interpolated 

3 DVMT is for the nonattainment portion of Cocke County consisting only of the area in the GSMNP.

41 
Table 4-8: Onroad NOx Emissions Summary for the 

Knoxville 8-hour Ozone Nonattainment Area 

County NOX Emissions in tons/day 

2007 2010 2013 2016 2020 2024 

Anderson 6.24 5.47 4.70 3.93 2.90 1.87

Blount 4.58 4.19 3.79 3.39 2.85 2.32

Cocke* 0.02 0.02 0.02 0.02 0.02 0.01

Jefferson 10.87 9.42 7.96 6.51 4.57 2.63

Knox 33.81 29.76 25.71 21.66 16.27 10.87

Loudon 9.99 8.62 7.25 5.88 4.05 2.22

Sevier 6.32 5.62 4.93 4.23 3.30 2.37

Totals 71.83 63.10 54.36 45.62 33.96 22.29 

% Change from 2007 -12% -24% -36% -53% -69% 

* GSMNP only. 

Table 4-9: Onroad VOC Emissions Summary for the 

Knoxville 8-hour Ozone Nonattainment Area 

County VOC Emissions in tons/day 

2007 2010 2013 2016 2020 2024 

Anderson 2.93 2.66 2.39 2.12 1.75 1.39

Blount 4.24 3.94 3.63 3.33 2.92 2.52

Cocke* 0.02 0.02 0.02 0.02 0.02 0.01

Jefferson 2.74 2.49 2.25 2.00 1.68 1.35

Knox 19.32 17.61 15.90 14.19 11.91 9.63

Loudon 2.65 2.40 2.15 1.90 1.56 1.22

Sevier 4.87 4.41 3.95 3.49 2.88 2.27

Totals 36.77 33.53 30.29 27.05 22.72 18.39 

% Change from 2007 -9% -18% -26% -38% -50% 

* GSMNP only. 

MOTOR VEHICLE EMISSIONS BUDGET 

Transportation Conformity, as established in the Clean Air Act, is intended to ensure that federally 

funded or approved transportation projects, plans or programs conform to the applicable State 

Implementation Plan (SIP). This requirement is achieved through the establishment of a motor 

vehicle emissions budget for the applicable pollutants. 

Pursuant to the EPA’s transportation conformity rule in 40 CFR Part 93, specific emission budgets 

are hereby defined for the onroad mobile sources portion of the emissions inventory. These budgets 

are to be used by the transportation authorities to assure that transportation plans, programs, and 

projects are consistent with, and conform to, the maintenance of acceptable air quality in the 

Knoxville area. The last year of this maintenance plan is 2024. Specific Motor Vehicle Emissions 

Budgets (MVEB) for NOx and VOC for 2024 are contained in Table 4-11. 

The MVEB reflects the total onroad emissions for 2024, plus an allocation from the available NOx

and VOC safety margins. This allocation from the safety margin accounts for uncertainty in the 

42 
projections and is available due to reductions in NOx and VOC that are projected to occur primarily 

from onroad mobile sources. The MVEB is constrained to assure that the total emissions (i.e., all 

source categories) do not exceed the 2007 attainment year emissions. The available safety margin is 

illustrated in Table 4-10. 

Table 4-10: Emission Projections for the Knoxville Area 

Summary of NOX Emissions (tons/day) 

Year Point Area Onroad Nonroad 

(excluding 

MLA) 

Nonroad 

(MLA) 

Total Safety 

Margin 

Change 

from 

2007 

2007 42.69 2.07 71.83 13.16 5.44 135.19

2010 42.65 2.15 63.10 12.17 5.03 125.10 10.09 -7.5%

2013 42.94 2.29 54.36 10.51 4.34 114.44 20.75 -15.3%

2016 43.56 2.50 45.62 8.74 3.61 104.03 31.16 -23.0%

2020 44.30 2.60 33.96 7.21 2.98 91.05 44.14 -32.7%

2024 45.11 2.68 22.29 6.37 2.63 79.08 56.11 -41.5%

Note: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevier and onroad emissions for Cocke County.

MLA = Commercial Marine Vessels, Locomotives and Aircraft.

Summary of VOC Emissions (tons/day) 

Year Point Area Onroad Nonroad 

(excluding 

MLA) 

Nonroad 

(MLA) 

Total Safety 

Margin 

Change 

from 

2007 

2007 7.32 33.25 36.77 34.26 0.68 112.28

2010 7.17 34.21 33.53 31.05 0.62 106.58 5.7 -5.1%

2013 7.37 35.23 30.29 26.47 0.52 99.88 12.40 -11.0%

2016 7.88 36.64 27.05 22.07 0.44 94.08 18.20 -16.2%

2020 8.64 38.40 22.72 18.04 0.35 88.15 24.13 -21.5%

2024 9.53 40.24 18.39 16.62 0.33 85.11 27.17 -24.2%

Note: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevier and onroad emissions for Cocke County.

MLA = Commercial Marine Vessels, Locomotives and Aircraft.

Under 40 CFR 93.101, the term safety margin is the difference between the attainment level (from

all sources) and the projected level of emissions (from all sources) in the maintenance plan. The 

attainment level of the emission is the level of emissions during one of the years in which the area 

met the NAAQS for the pollutant of concern. The safety margin, or portion of the safety margin, 

can be allocated to the transportation sector; however, the total emissions must remain at or below 

the attainment level. A portion of the available 2024 safety margin is allocated to the MVEB. 

Specifically, 14.03 tons/day of the available NOx safety margin is allocated to the 2024 MVEB, the 

remaining safety margin for NOx for 2024 is 42.08 tons/day. Also, 6.8 tons/day of the available 

VOC safety margin is allocated to the 2024 MVEB, the remaining safety margin for VOC for 2024 

is 21.09 tons/day. The Motor Vehicle Emissions Budgets including safety margins for the Greater 

Knoxville 1997 8-hour Ozone Nonattainment Area (Anderson, Blount, Jefferson, Knox, Loudon 

and Sevier Counties and the portion of Cocke County that falls within the boundaries of the Great 

Smoky Mountains National Park) are contained in Table 4-11. 

43 
Table 4-11: Motor Vehicle Emissions Budgets for NOx and VOC for 2024 

 

2024 

(tons/day

) 

NOx 36.32 

VOC 25.19 

The MVEB is consistent with the plan for maintaining total emissions from all source categories at 

or below the 2007 NOx and VOC emissions levels through the year 2024. For future conformity 

determinations, transportation authorities should rely on the above MVEB unless this maintenance 

plan is revised. 

Nonroad Mobile Sources

The emission inventory for nonroad mobile sources was obtained from E. H. Pechan & Associates27, 

Inc., the contractor for the Southeastern Modeling, Analysis, and Planning (SEMAP) project. The 

SEMAP Project is funded by ten States28 and addresses ozone, fine particle, and regional haze 

obligations through grants awarded by EPA. The SEMAP project and the in-kind services of the 

participating agencies are designed to produce technical analyses to aid the participating agencies in 

developing SIPs required by the Clean Air Act. SEMAP is currently developing future-year 

modeling for ozone, fine particle, and regional haze based on the same base year (2007) that was 

used for this emission inventory. 

Emission estimates from nonroad mobile sources are based on EPA’s NONROAD2008 model, 

which includes estimates for growth based on expected future economic conditions and other factors

as well as any national controls that apply to these sources in future years (Table 4-12, Table 4-13). 

EPA’s National Mobile Inventory Model (NMIM), which incorporates EPA’s latest NONROAD 

model, was used for the NONROAD model portion of the inventory. Using the 2007 base year and 

corresponding year NMIM county-level database (NCD) was used to develop the most 

representative NONROAD model inventory, and NMIM was used to generate annual emission 

estimates for the required pollutants. 

Estimates of aircraft, locomotive, and commercial marine (ALM) emissions are not produced by the 

NONROAD model. ALM emissions for 2007 were primarily based on EPA’s 2008 National 

Emissions Inventory (NEI), as described in EPA’s 2008 NEI documentation. The SEMAP 

contractor’s methodology for developing the ALM emissions inventory is included in Appendix F of

Attachment A. 

 

27 Portions of the nonroad inventory discussion are taken from the document Non-road and Area Source Base Year and 

Future Year Emissions Inventories Final Work Plan, E. H. Pechan & Associates, Inc., July 13, 2009. A copy of this 

work plan is included in Attachment A. 

28 The SEMAP States are: Alabama, Kentucky, Florida, Georgia, Mississippi, North Carolina, South Carolina, 

Tennessee, Virginia, and West Virginia. SEMAP was developed and is managed through the Southeastern States Air 

Resource Managers (SESARM). 

44 
Future-year emissions were projected for 2010, 2013, 2016, 2020, and 2024, using 2007 emissions 

and EGAS 5.0 growth factors. Growth factors obtained from EGAS 5.0 were multiplied by the 2007 

emission values to calculate emissions for future years. 

Overall, projected emissions from nonroad sources appear to be decreasing between 2007 and 2024. 

Most segments show a reduction in nonroad emissions except for NOX emissions from “Pleasure 

Craft” and “Recreational Equipment”. Detailed emissions estimates by equipment category are 

contained in Appendix F of Attachment A. 

Table 4-12: NOX Emissions from Nonroad Sources (excluding Commercial Marine, 

Locomotive and Aircraft) 

NOX, Typical Summer Day, July (tons/day) 

County 2007 2010 2013 2016 2020 2024 

Anderson 1.34 1.13 0.91 0.72 0.58 0.52

Blount 1.69 1.52 1.28 1.05 0.86 0.75

Jefferson 1.20 1.24 1.21 1.10 0.99 0.91

Knox 6.82 6.24 5.26 4.26 3.40 2.95

Loudon 1.00 0.96 0.87 0.76 0.66 0.59

Sevier 1.11 1.08 0.99 0.85 0.72 0.64

Totals 13.16 12.17 10.52 8.74 7.21 6.36 

 

Table 4-13: VOC Emissions from Nonroad Sources (excluding Commercial Marine, 

Locomotive and Aircraft) 

VOC, Typical Summer Day, July (ton/day) 

County 2007 2010 2013 2016 2020 2024 

Anderson 2.92 2.66 2.27 1.87 1.49 1.35

Blount 4.12 3.75 3.22 2.70 2.22 2.07

Jefferson 5.34 4.65 3.75 2.96 2.18 1.77

Knox 9.34 8.04 6.60 5.70 5.26 5.22

Loudon 3.31 2.95 2.44 1.97 1.51 1.30

Sevier 9.24 9.01 8.18 6.87 5.39 4.92

Totals 34.27 31.06 26.46 22.07 18.05 16.63

For this assessment of nonroad sources, future-year emissions for aircraft, commercial marine 

vessels, and locomotives were based on 2007 information projected to future years using EGAS-5.0 

growth factors. Table 4-14 and Table 4-15 summarize the emissions from locomotive, commercial 

marine and aircraft by county. 

45 
Table 4-14: NOX Emissions from Locomotive, Commercial Marine, and Aircraft 

Table 4-14(a): NOX Emissions from Aircraft 

Typical Summer Day (tons) 

FIPS County 2007 2010 2013 2016 2020 2024 

47001 Anderson 0.00 0.00 0.00 0.00 0.00 0.00

47009 Blount 0.38 0.34 0.28 0.23 0.19 0.17

47089 Jefferson 0.00 0.00 0.00 0.00 0.00 0.00

47093 Knox 0.01 0.01 0.01 0.00 0.00 0.00

47105 Loudon 0.00 0.00 0.00 0.00 0.00 0.00

47155 Sevier 0.00 0.00 0.00 0.00 0.00 0.00

Totals: 0.39 0.35 0.29 0.23 0.19 0.17

Table 4-14(b): NOX Typical Summer Day Locomotive & Commercial Marine 

Totals by SCC Category, All Counties (tons) 

SCC Description 2007 2010 2013 2016 2020 2024 

2280002200 CMV, UNDERWAY EMISSIONS: 

DIESEL 0.02 0.01 0.01 0.01 0.01 0.01

2285002006 RAILROAD EQUIPMENT, 

DIESEL LINE HAUL: CLASS I 4.89 4.52 3.91 3.25 2.68 2.37 

2285002007 

RAILROAD EQUIPMENT, 

DIESEL LINE HAUL 

LOCOMOTIVES: CLASS II/III 

OPERATIONS 0.14 0.13 0.11 0.10 0.08 0.07

Totals 5.05 4.66 4.03 3.36 2.77 2.45

Table 4-15: VOC Emissions from Locomotive, Commercial Marine, and Aircraft 

Table 4-15(a): VOC Emissions from Aircraft 

Typical Summer Day, July (tons/day) 

FIPS County 2007 2010 2013 2016 2020 2024 

47001 Anderson 0.01 0.01 0.01 0.01 0.01 0.01

47009 Blount 0.17 0.15 0.13 0.10 0.10 0.17

47089 Jefferson 0.00 0.00 0.00 0.00 0.00 0.00

47093 Knox 0.10 0.08 0.07 0.07 0.06 0.10

47105 Loudon 0.02 0.02 0.01 0.01 0.01 0.02

47155 Sevier 0.07 0.06 0.05 0.04 0.04 0.07

Totals: 0.37 0.32 0.27 0.23 0.22 0.37

46 
Table 4-15(b): VOC Typical Summer Day Locomotive & Commercial Marine 

Totals by SCC Category, All Counties (tons) 

SCC Description 2007 2010 2013 2016 2020 2024 

2280002200 CMV, UNDERWAY EMISSIONS: 

DIESEL 0.00 0.00 0.00 0.00 0.00 0.00

2285002006 RAILROAD EQUIPMENT, 

DIESEL LINE HAUL: CLASS I 0.27 0.24 0.21 0.17 0.14 0.13 

2285002007 

RAILROAD EQUIPMENT, 

DIESEL LINE HAUL 

LOCOMOTIVES: CLASS II/III 

OPERATIONS 0.01 0.01 0.00 0.00 0.00 0.00

Totals 0.28 0.25 0.21 0.17 0.14 0.13 

Biogenic Sources

VOC emissions from biogenic sources are expected to remain relatively constant between 2007 and 

2024, and were not considered in the maintenance plan’s inventory. 

Commitment to Continued Monitoring, §175A(d) Requirements

Tennessee will continue air quality monitoring in accordance with 40 CFR 58. In accordance with 

§175A(d) of the Clean Air Act, Tennessee will implement any measures which exist in the current 

State Implementation Plan for ozone. No measures in the State Implementation Plan have been 

discontinued or moved to the maintenance plan. 

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5.0 CONTINGENCY MEASURES 

The contingency plan provisions of the CAA are designed to result in prompt correction or 

prevention of NAAQS violations that might occur after redesignation of an area to attainment of the 

NAAQS. Section 175A of the CAA requires that a maintenance plan include such contingency 

measures as EPA deems necessary to assure that the State will promptly correct a NAAQS violation 

that might occur after redesignation. The maintenance plan must identify the contingency measures 

to be considered for possible adoption, a schedule for adoption and implementation of the selected 

contingency measures, and a time limit for action by the State. 

The two main elements of the contingency plan are triggering mechanisms to determine when 

contingency measures are needed and a process of developing and adopting appropriate control 

measures. The primary trigger of the contingency plan will be a quality assured/quality controlled 

violating design value (DV) of the 8-hour ozone NAAQS at any monitor. Upon activation of the 

trigger, the State of Tennessee, in conjunction with the Knox County Department of Air Quality 

Management (DAQM), will commence an analysis to determine what additional measures will be 

necessary to attain or maintain the 8-hour ozone standard. Since transport from outside the region 

often impacts the local monitors, an evaluation to determine the amount of local emission 

contribution to the high ozone days may be conducted. In addition to the primary trigger indicated 

above, Tennessee and Knox County DAQM will monitor regional emissions through the CERR. If 

the CERR results indicate that the projected emissions in this maintenance plan are significantly less 

than the CERR reveals (more than 10 percent), Tennessee and Knox County DAQM will investigate 

the differences and develop an appropriate strategy for addressing these differences. In addition, if 

ambient monitoring data indicates that a violation of the three-year design value may be imminent, 

Tennessee and Knox County DAQM will evaluate existing control measures to determine whether 

further emission reduction measures should be implemented. 

A trigger level response will consist of a study to determine whether the ozone value indicates a 

trend toward higher ozone concentrations or whether emissions appear to be increasing. The study 

will evaluate whether the trend, if any, is likely to continue and, if so, the control measures 

necessary to reverse the trend, taking into consideration ease and timing for implementation, as well 

as economic and social considerations. If new emission control measures are already promulgated 

and scheduled to be implemented at the Federal or State level, and if those measures are determined

to be sufficient to address the increase in peak ozone concentrations, additional local measures may

be unnecessary. The State will submit to the EPA an analysis to assess whether the proposed 

emission control measures are adequate to reverse the increase in peak ozone concentrations and to 

maintain the 8- hour ozone standard in the area. 

If additional controls are necessary, Tennessee and the Knox County DAQM will implement the 

appropriate contingency measures needed to assure future attainment of the ozone NAAQS. TDEC 

and the Knox County Department of Air Quality Management will complete sufficient analyses and 

provide those to the EPA. If determined necessary, the adoption of rules for ensuring attainment and 

maintenance of the 8-hour ozone NAAQS will begin. Contingency measures would be adopted and 

implemented as expeditiously as possible, but no later than eighteen to twenty-four months after the 

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triggering event29. The proposed schedule for these actions would be as follows: 

• Six months to identify appropriate contingency measures, including identification of 

emission sources and appropriate control technologies; 

• Between three and six months to initiate a stakeholder process; and 

• Between nine and twelve months to implement the contingency measures. This step would 

include the time required to draft rules or SIP amendments, complete the rulemaking 

process, and submit the final plans to EPA. 

If it is determined that a longer schedule is required to implement specific contingency measures, 

then, upon selection of the appropriate measures, Tennessee will notify EPA of the proposed 

schedule and will provide sufficient information to EPA to demonstrate that the proposed measures 

are a prompt correction of the triggering event. 

The selection of emission control measures will be based on cost-effectiveness, emission reduction 

potential, economic and social considerations, or other factors that the State deems to be appropriate. 

Selected emission control measures will be subject to public review, and the State will seek public 

input prior to selecting new emission control measures. 

The measures that will be considered for adoption upon a trigger of the contingency plan include the 

following: 

• Implementation of diesel retrofit programs, including incentives for performing retrofits 

• Reasonable Available Control Technology (RACT) for NOX sources in nonattainment 

counties 

• Programs or incentives to decrease motor vehicle use, including employer-based programs, 

additional park and ride services, enhanced transit service and encouragement of flexible 

work hours/compressed work week/telecommuting. 

• Trip reduction ordinances 

• Additional emissions reductions on stationary sources 

• Enhanced stationary source inspection to ensure that emissions control equipment is 

functioning properly 

• Voluntary fuel programs, including incentives for alternative fuels 

 

29 If quality assured/quality controlled data indicates a violating design value for the 8-hour ozone NAAQS, then the 

triggering event will be the date of the design value violation, and not the final QA/QC date. However, if initial 

monitoring data indicates a possible design value violation but later QA/QC indicates that a NAAQS violation did not 

occur, then a triggering event will not have occurred, and contingency measures will not need to be implemented. 

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• Construction of high-occupancy vehicle (HOV) lanes, or restriction of certain roads or lanes 

for high-occupancy vehicles 

• Programs for new construction and major reconstruction of bicycle and pedestrian facilities, 

including shared use paths, sidewalks and bicycle lanes. 

• Expand Air Quality Action Day activities/Clean Air Partners public education outreach 

• Expansion of E-government services at State and local level 

• Additional enforcement or outreach on driver observance of reduced speed limits 

• Land use/transportation policies 

• Promote non-motorized transportation 

• Promote tree-planting standards that favor trees with low VOC biogenic emissions 

• Promote energy saving plans for local government 

• Gas can and lawnmower replacement programs 

• Seasonal open burning ban in nonattainment counties 

• Evaluate anti-idling rules and/or policy 

• Additional controls in upwind areas, if necessary 

Other control measures, not included in the above list, will be considered if new control programs 

are deemed more advantageous for this area. 

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6.0 CONCLUSIONS 

As the preceding document has shown, air quality monitoring data for the Knoxville nonattainment 

area indicates that ozone levels have declined between 2007 through 2009, and the area now shows 

attainment of the NAAQS at the controlling monitor. The decrease in ozone concentrations is a 

result of permanent and enforceable emissions reductions, and the emission inventory indicates 

further emissions reductions between 2007 and 2024. Tennessee is petitioning EPA for 

redesignation of the Knoxville 8-hour ozone Nonattainment area to attainment based on an attaining 

three-year design value for the period 2007-2009. 

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