Georgia's State Implementation Plan 

for the 

Atlanta 8-Hour Ozone Nonattainment Area 

September 8, 2009 

Prepared by: 

Georgia Department of Natural Resources 

Environmental Protection Division 

Air Protection Branch 
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The Atlanta Eight-Hour Ozone Attainment Demonstration 

PREFACE 

This document contains Georgia's modeling demonstration that the metro Atlanta region 

8-hour ozone nonattainment area will meet the National Ambient Air Quality Standard 

for 8-hour ozone by June 15, 2010. This area includes the entire counties of Barrow, 

Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, 

Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and Walton.

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

EXECUTIVE SUMMARY 

INTRODUCTION 

Ozone, a strong chemical oxidant, adversely impacts human health through effects on 

respiratory function and can also damage forests and crops. Ozone is not emitted directly 

but instead is formed in the lower atmosphere (the troposphere) by a complex series of 

chemical reactions involving nitrogen oxides (NOx) and reactive volatile organic 

compounds (VOCs). NOx emissions are the result of combustion processes at electric 

utilities, industrial sources, motor vehicles, and other non-road and area sources. VOCs 

include many industrial solvents as well as the various hydrocarbons (HC) that are 

evaporated from the gasoline used by motor vehicles or emitted through the tailpipe 

following combustion. Additionally, VOCs are emitted by natural sources such as trees 

and crops. 

Ozone formation is promoted by strong sunlight, warm temperatures and light winds. 

High concentrations tend to be a problem in the eastern United States only during the hot 

summer months when these conditions frequently occur. Therefore, the U.S. 

Environmental Protection Agency (USEPA) mandates seasonal monitoring of ambient 

ozone concentrations in Georgia from March 1 through October 31 (40 CFR 58 App. D, 

Table D-3). 

NATIONAL AMBIENT AIR QUALITY STANDARD (NAAQS) 

The Clean Air Act (CAA) establishes a process for air quality management through the 

National Ambient Air Quality Standards (NAAQS). Area designations are required after 

promulgation of a new or revised NAAQS. In 1979, EPA promulgated the 0.12 parts per 

million (ppm) 1-hour ozone standard (44 FR 8202, February 8, 1979). On July 18, 1997, 

EPA promulgated a revised ozone standard of 0.08 ppm, measured over an 8-hour period, 

i.e., the 8-hour standard (62 FR 38856). The 1997 NAAQS rule was challenged by 

numerous litigants and the legal challenges were resolved by March of 2002. 

A violation of the NAAQS occurs when the average of the annual fourth highest daily 

maximum 8-hour ozone values over three consecutive years is equal to or greater than 

0.085 ppm. This three-year average is termed the design value for the monitor. The 

design value for a nonattainment area is the highest monitor's design value in the area. 

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

REGULATORY HISTORY OF OZONE PROBLEM IN ATLANTA, GEORGIA 

Pursuant to the Clean Air Act Amendments of 1990 (CAAA), the Atlanta area was 

designated as nonattainment for the pollutant ozone by U.S. EPA and was classified as a 

serious 1-hour ozone nonattainment area on November 6, 1991. The 1-hour ozone 

nonattainment area (NAA) was at that time geographically defined as the following 13 

Georgia counties: Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, 

Fulton, Gwinnett, Henry, Paulding, and Rockdale. Because Atlanta failed to attain the 1-

hour ozone NAAQS by November 15, 1999, EPA issued a final rulemaking action in the 

September 26, 2003, Federal Register (68 FR 55469) determining that, by operation of 

law, the Atlanta area was being reclassified as a "severe" ozone nonattainment area 

effective January 1, 2004. In addition to having been required to submit state 

implementation plan (SIP) revisions meeting requirements for marginal, moderate, and 

serious ozone nonattainment areas, Georgia was required to submit plans meeting the 

additional requirements for areas classified as severe. As a result of EPA's 

implementation of the original federal Clean Air Act of 1970, the Clean Air Act 

Amendments of 1977, and the Clean Air Act Amendments of 1990, EPD has completed, 

and EPA has approved (67 FR 30574), SIP revisions to address the Atlanta one hour 

ozone nonattainment area. 

On February 1, 2005, EPD requested that the Atlanta area be redesignated from 

nonattainment to attainment with respect to the 1-hour ozone NAAQS in accordance with 

section 107(d) of the Clean Air Act. This request was based on three years, 2002 through 

2004, of ambient monitoring data at all 11 ozone monitors in the Atlanta NAA showing 

no violation of the 1-hour ozone NAAQS; the implementation of permanent and 

enforceable reductions in ozone precursor emissions; compliance with all applicable 

requirements; and the Atlanta Maintenance Plan with projections demonstrating that the 

2002 emission levels in this area will not be exceeded through at least the year 2015. 

EPD also petitioned EPA to make a determination that the Atlanta area was eligible for 

application of EPA's Clean Data Policy, based on the Atlanta area's attainment of the 1-

hour ozone NAAQS. EPA approved the plan and redesignation request effective June 

14, 2005 (70 FR 34660). 

Ozone design-values (DV; three year average of the 4th highest reading per year) for the 

2001-2003 period, which was used in designating the Atlanta 20 county area as 

nonattainment, show that 10 out of the 11 sites exceed the 8-hour ozone NAAQS (0.08 

ppm). The highest design value for these 11 sites was 0.091 ppm. Therefore, on April 30, 

2004, EPA designated 20 metropolitan Atlanta counties as a "marginal" nonattainment 

area under the 8-hour ozone standard. The eight-hour ozone nonattainment area 

encompasses the 13 counties of the former 1-hour ozone nonattainment area plus seven 

additional "ring" counties: Barrow, Bartow, Carroll, Hall, Newton, Spalding, and 

Walton. With an attainment deadline of June 15, 2007, marginal areas were required to 

attain the National Ambient Air Quality Standard (NAAQS) by the 2006 ozone season. 

Because monitoring data from the 2006 ozone season indicates that Atlanta has not 

attained the NAAQS, the area was reclassified to a higher classification (i.e., 

"moderate"). On October 16, 2007, EPA proposed to find that the Atlanta, Georgia 

5 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

"marginal" 8-hour nonattainment ozone area had failed to attainment the 8-hour ozone 

NAAQS by June 15, 2007, and to reclassify the Atlanta, Georgia nonattainment area as a 

“moderate” 8-hour ozone nonattainment area. This finding and reclassification was 

finalized on March 6, 2008 [73 FR 12013-12017]. The "moderate" area attainment date 

for the Atlanta, Georgia area would then be "as expeditiously as practicable," but no later 

than June 15, 2010. As part of this reclassification, EPA required the submittal of an 8-

hour ozone SIP revision to be submitted "as expeditiously as practicable" but not later 

than December 31, 2008. 

This submittal represents an attainment demonstration (40 CFR 51.908) for the Atlanta 

metro 8-hour ozone nonattainment area that consists of the following counties: Barrow, 

Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, 

Fulton, Gwinnett, Henry, Newton, Paulding, Pickens, Rockdale, Spalding, and Walton 

counties. 

CONTROLS APPLIED 

Attaining the federal 8-hour ozone NAAQS will require the involvement of all sectors of 

Georgia's economy and population. Significant reductions in man-made sources of VOC 

and NOx were achieved via state and federal regulatory and voluntary control measures 

for attainment of the 1-hour ozone NAAQS. This set of existing requirements and 

voluntary efforts serve as the basis for considering further control measures. Since the 

metro Atlanta region is also designated nonattainment for the federal PM2.5 standards, 

control strategies for PM2.5 and the 8-hour ozone NAAQS will be integrated and 

harmonized to the extent possible. 

Control measures already in place or being implemented over the next few years will 

reduce stationary point, highway mobile, and nonroad mobile sources emissions. The 

expected Federal and State control measures were modeled for the attainment year of 

2009. 

The Federal control measures that were modeled included the Clean Air Interstate Rule, 

Federal Ozone Measures (CAA Section 183(e)), motor vehicle emission and fuel 

standards (e.g., Tier 0, 1, and 2 emission standards; gasoline volatility requirements; and 

fuel sulfur requirements), and nonroad engines and vehicles emission standards. The 

State control measures that were modeled include the vehicle emissions inspection and 

maintenance program; Georgia's 45-county Gasoline Marketing Rule, 391-3-1-

.02(2)(bbb); existing VOC and NOx RACT measures; and new Georgia Rule 391-3-1-

.02(2)(sss) Multipollutant Control for Electric Utility Generating Units which establishes 

a schedule for the installation and operation of NOx and sulfur dioxide pollution control 

systems on many of the coal-fired power plants in and around the Atlanta metro area. 

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

ATTAINMENT RESULTS 

Georgia EPD conducted an attainment demonstration in accordance with the US EPA's 

September 2006 draft final Guidance On The Use Of Models And Other Analyses for 

Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze 

("Attainment Guidance"). Section 3.0 of the Attainment Guidance recommends applying 

both a modeled attainment test and a subsequent unmonitored area analysis to the air 

quality modeling results to determine if the 8-hour ozone NAAQS will be met. 

Additional technical or corroboratory analyses may also be used as part of a "weight of 

evidence" determination to supplement the modeled attainment test and to further support 

a demonstration of attainment of the NAAQS. 

The EPD has evaluated future ozone design values using a combination of two methods 

for calculating modeling baseline design values (DVBs) (2001-2003 and weighted 2000-

2004), and two methods for calculating the relative response factors (RRFs) ("maximum 

in array" and "monitor grid cell"). A summary of future design values (DVFs) based on 

these four test configurations is given in Table E-1. DVFs for ten out of the eleven 

monitors show attainment of the 8-hour ozone NAAQS using the 2000-04 DVB and 

"maximum in array" method. However, all eleven sites show attainment of the NAAQS 

when using the "monitor grid cell" approach or when using the 2001-03 DVB. 

Table E-1: Atlanta attainment test results for 2009 based on four different test 

configurations. 

Bold red numbers indicate DVF at or above 85 ppb; Bold, underlined green numbers 

indicate DVF below 85 ppb but within weight-of-evidence range; Standard-font green 

numbers indicate DVF below 82 ppb. 

Site name AIRS ID 

2000-04 DVB; 

"max in 

array" 

2000-04 DVB; 

"monitor 

grid cell" 

2001-03 DVB; 

"max in 

array" 

2001-03 DVB; 

"monitor 

grid cell" 

Conf. Ave. 13-121-0055 86 84 83 82

McDonough 13-151-0002 80 80 77 77 

Douglasville 13-097-0004 80 80 80 80 

Kennesaw 13-067-0003 81 81 80 80 

Tucker 13-089-3001 82 82 81 80 

Conyers 13-247-0001 79 79 77 77 

S. DeKalb 13-089-0002 82 80 80 78 

Newnan 13-077-0002 77 76 76 74 

Lawrenceville 13-135-0002 79 79 76 77 

Yorkville 13-223-0003 75 75 76 76 

Fayetteville 13-113-0001 75 75 73 73 

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

The modeled attainment demonstration performed according to EPA guidance results in a 

single monitor in the Atlanta NAA exceeding the 8-hour ozone NAAQS (DVF of 86 ppb 

at the Confederate Avenue monitoring site). However, the weight of evidence analysis 

demonstrated in Section 6.2 of this document provides strong evidence that the Atlanta 8-

Hour Ozone NAA will demonstrate attainment of the ozone NAAQS by 2009. The 

attainment demonstration with the weight of evidence analysis is effective since the 

unmonitored area analysis showed no modeling grid cell greater than 86 ppb. 

Furthermore, the additional emission control or reduction measures identified in Section 

5.3 of this document as well as those contingency measures that will be implemented, 

regardless of attainment status, will provide additional emission reductions beyond those 

quantified and modeled for this attainment demonstration. Therefore Georgia EPD 

concludes that this document provides an adequate demonstration of compliance with the 

8-Hour Ozone NAAQS for the Atlanta 8-Hour Ozone NAA by the year 2009. 

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

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9 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

TABLE OF CONTENTS 

PREFACE.......................................................................................................................... 3

EXECUTIVE SUMMARY .............................................................................................. 4

INTRODUCTION.............................................................................................................. 4

NATIONAL AMBIENT AIR QUALITY STANDARD (NAAQS)................................... 4

REGULATORY HISTORY OF OZONE PROBLEM IN ATLANTA, GEORGIA......... 5

CONTROLS APPLIED ..................................................................................................... 6

ATTAINMENT RESULTS................................................................................................ 7

1.0 INTRODUCTION............................................................................................... 20

1.1 Ozone as an Air Pollutant................................................................................. 20

1.2 Ozone as a National Ambient Air Quality Standard......................................... 22

1.3 Regulatory History of Atlanta's Smog Problem................................................ 23

1.4 Nonattainment Area Designation for 8-Hour Ozone in Atlanta....................... 23

1.5 8-Hour Ozone Design Values in Atlanta .......................................................... 27

1.6 SIP Requirements for Moderate Nonattainment Areas .................................... 28

2.0 CONCEPTUAL DESCRIPTION OF 8-HOUR OZONE LEVELS IN 

ATLANTA AND GEORGIA......................................................................................... 34

2.1 Conditions Leading to Elevated Ozone in the Atlanta Area............................. 40

2.1.1 Analysis of PAMS data in Atlanta using Ozone M.A.P.P.E.R................. 43 

2.2 Weekday/weekend trends in ozone concentrations........................................... 46

2.3 Conclusions....................................................................................................... 47

3.0 ATTAINMENT DEMONSTRATION METHODS AND INPUTS............... 49

3.1 Analysis Method................................................................................................ 49

3.2 Model Selection................................................................................................. 50

3.2.1 Selection of Photochemical Grid Model................................................... 50 

3.2.2 Selection of Meteorological Model .......................................................... 51 

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

3.2.3 Selection of Emissions Processing System............................................... 54 

3.3 Episode Selection.............................................................................................. 55

3.3.1 Overview of U.S.EPA Guidance on Ozone.............................................. 55 

3.3.2 Episode Selection...................................................................................... 56 

3.4 Modeling Domains............................................................................................ 56

3.4.1 Horizontal Modeling Domain................................................................... 56 

3.4.2 Vertical Modeling Domain ....................................................................... 58 

3.5 Emission Inventory............................................................................................ 59

3.5.1 Types of Emission Inventories.................................................................. 59 

3.5.2 Emission Inventory Source Classification................................................ 60 

3.5.3 Stationary Point Sources........................................................................... 64 

3.5.4 Stationary Area Sources............................................................................ 66 

3.5.5 Off-Road Mobile Sources......................................................................... 67 

3.5.6 Highway Mobile Sources.......................................................................... 67 

3.5.7 Biogenic Emission Sources....................................................................... 68 

3.5.8 Emission Inventory Summary for Atlanta Nonattainment Area............... 69 

4.0 MODEL PERFORMANCE EVALUATION................................................... 72

4.1 MM5 Model Performance Evaluation ................................................................... 72

4.2 CMAQ Air Quality Model Performance Evaluation ............................................. 78

4.2.1 Air Quality Modeling Evaluation Methodology.............................................. 78 

4.2.2 Air Quality Modeling Evaluation Results....................................................... 81 

5.0 CONTROLS APPLIED.................................................................................... 103

5.1 Control Measures Analyses for Stationary Point and Area Sources.............. 104

5.2 Control Measures Analyses for On-Road Mobile Sources............................. 111

5.3 Control Measures Analyses for Off-Road Mobile Sources............................. 114

5.4 Action Plan for Reducing Emissions with Voluntary Control Measures........ 120

5.4.1 Emission Reductions from Transportation Measures............................. 121 

5.4.2 Retrofits/Use of Alternative Fuels.......................................................... 124 

5.4.3 Energy Demand Reduction..................................................................... 126 

5.4.4 Activities at Hartsfield-Jackson Atlanta International Airport............... 128 

6.0 ATTAINMENT DEMONSTRATION............................................................ 130

6.1 Modeled Attainment Test ................................................................................ 130

6.2 Weight of Evidence ......................................................................................... 132

6.2.1 Use of Monitor Grid to Calculate RRFs................................................. 133 

6.2.2 Use of Alternative DVB to Calculate DVF ............................................ 134 

6.3 Local Measures not Modeled.......................................................................... 136

6.4 Unmonitored Area Analysis............................................................................ 136

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

6.5 Summary ......................................................................................................... 141

6.6 Attainment Conclusion.................................................................................... 142

7.0 SENSITIVITY OF OZONE IN ATLANTA TO NOx AND VOC 

EMISSIONS .................................................................................................................. 143

7.1 Cases Modeled................................................................................................ 143

7.2 Results............................................................................................................. 144

7.3 Discussion....................................................................................................... 146

8.0 OTHER CLEAN AIR ACT REQUIREMENTS ........................................... 147

8.1 RACT/RACM Requirements............................................................................ 147

8.2 Reasonable Further Progress......................................................................... 147

8.3 Actual Emissions Inventory............................................................................. 147

8.4 Emissions Inventory Statement ....................................................................... 148

8.5 Periodic Emissions Inventory ......................................................................... 148

8.6 Permit Program Requirements....................................................................... 148

8.7 Inspection and Maintenance Program............................................................ 148

8.8 Other Measures............................................................................................... 149

8.9 Compliance with Section 110(a)(2) ................................................................ 149

8.10 Equivalent Techniques.................................................................................... 149

8.11 Contingency .................................................................................................... 149

8.11.1 Contingency Overview ........................................................................... 149 

8.11.2 Contingency Measures............................................................................ 149 

8.11.3 Contingency Emission Reductions for Failure to Attain ........................ 150 

9.0 MOTOR VEHICLE EMISSIONS BUDGETS .............................................. 152

9.1 Background..................................................................................................... 152

9.2 Establishment of 2009 Motor Vehicle Emissions Budgets for the Atlanta 8-Hour 

Ozone Nonattainment Area......................................................................................... 152

10.0 REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT) 

ANALYSIS .................................................................................................................... 155

11.0 INFRASTRUCTURE SIP ELEMENTS......................................................... 196

12.0 REFERENCES.................................................................................................. 207

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

LIST OF FIGURES 

Figure 1-1: Diagram Illustrating Ozone Formation................................................... 21

Figure 1-2: Location of ozone monitors within the Atlanta 20-county nonattainment 

area ........................................................................................................................... 26

Figure 2-1: (a) Area-average and (b) single-site area-maximum ozone DVs for 2001-

2006........................................................................................................................... 37

Figure 2-2: (a) Area-average and (b) single-site area-maximum number of 

exceedances of the ozone NAAQS level (expressed as 85 ppb) in 2001-2006. ... 38

Figure 2-3: Inter-annual trends in NOx emissions (total Georgia EGU and 13-county 

Atlanta on-road mobile-source emissions) and count of "ozone conducive days" 

for 1996-2005. .......................................................................................................... 40

Figure 2-4: Average diurnal pattern in extent of reaction for the four PAMS sites 

for 1997-2005 ........................................................................................................... 44

Figure 2-5: Average diurnal pattern in extent of reaction for 1997-2005 binned by 

the daily maximum 8-hour ozone concentration (<65ppb, 65-85ppb, 85-105ppb, 

>105ppb) for (a) Yorkville, (b) Tucker, (c) South-DeKalb, and (d) Conyers.... 45

Figure 2-6: Weekdays/weekend differences in ozone concentrations at the 

Confederate Avenue site and the four Atlanta PAMS sites for (a) 1997-2005, (b) 

1997-1999, (c) 2000-2002, and (d) 2003-2005........................................................ 47

Figure 3-1: The MM5 horizontal domain is the outer most, blue grid, with the 

CMAQ 36-km domain nested in the MM5 domain. ............................................ 57

Figure 3-2: A more detailed view of the 12-km grid over the VISTAS region.......... 58

Figure 3-3: Ozone season daily NOX and VOC emissions by source categories for 20 

counties in Atlanta. ................................................................................................. 70

Figure 3-4: Ozone season daily NOX and VOC Emissions by source categories and 

metro Atlanta 8-hour ozone nonattainment counties. ......................................... 71

Figure 4-1: Monthly averaged Bias statistics for 2-m temperature and humidity ... 76

Figure 4-2(a): Mean Normalized Bias for 1-hour and 8-hour ozone concentrations of 

CMAQ 12 km simulation at 11 monitor sites in 20 counties around Atlanta. .. 85

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-2(b): Mean Normalized Gross Error for 1-hour and 8-hour ozone 

concentrations of CMAQ 12 km simulation at 11 monitor sites in 20 counties 

around Atlanta. ....................................................................................................... 86

Figure 4-3: Daily Mean Normalized Bias over 20 counties around Atlanta for 

observed 1-hour O3 > 60 ppb. ................................................................................ 87

Figure 4-4: Daily Mean Normalized Gross Error over 20 counties around Atlanta 

for observed 1-hour O3 > 60 ppb. .......................................................................... 88

Figure 4-5: Daily Mean Normalized Bias over 20 counties around Atlanta for 

observed 8-hour O3 > 60 ppb. ................................................................................ 89

Figure 4-6: Daily Mean Normalized Gross Error over 20 counties around Atlanta 

for observed 8-hour O3 > 60 ppb. .......................................................................... 90

Figure 4-7(a): Mean Normalized Bias for daily maximum 1-hour and 8-hour ozone 

concentrations of CMAQ 12 km simulation at 11 monitor sites in 20 counties 

around Atlanta. ....................................................................................................... 91

Figure 4-7(b): Mean Normalized Gross Error for daily maximum 1-hour and 8-

hour ozone concentrations of CMAQ 12 km simulation at 11 monitor sites in 20 

counties around Atlanta. ........................................................................................ 92

Figure 4-8: Daily Mean Normalized Bias over 20 counties around Atlanta for daily 

maximum 1-hour O3 (paired in space).................................................................. 93

Figure 4-9: Daily Mean Normalized Gross Error over 20 counties around Atlanta 

for daily maximum 1-hour O3 (paired in space). ................................................. 94

Figure 4-10: Daily Mean Normalized Bias over 20 counties around Atlanta for daily 

maximum 8-hour O3 (paired in space).................................................................. 95

Figure 4-11: Daily Mean Normalized Gross Error over 20 counties around Atlanta 

for daily maximum 8-hour O3 (paired in space). ................................................. 96

Figure 4-12: Tile plot of daily 8-hour maximum ozone concentrations on June 12, 

2002........................................................................................................................... 97

Figure 4-13(a): Bar plots for daily maximum concentrations of 8-hour ozone......... 98

Figure 4-13(b): Bar plots for daily maximum concentrations of 1-hour ozone. ....... 99

Figure 4-13(c): Bar plots for daily maximum concentrations of nitrogen dioxides.100

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-14: Weekly time series plot for hourly ozone concentration at the 

Confederate Avenue site....................................................................................... 101

Figure 4-15: Scatter plot of 8-hour ozone concentrations at the Confederate Avenue 

site........................................................................................................................... 103

Data points are from observed and modeled 8-hour concentrations in June 2002. 103

Figure 6-1: Demonstration of EPD's MATS operation............................................. 138

Figure 6-2: Results of MATS when 21 days were used for spatial gradient 

calculations. ........................................................................................................... 139

Figure 6-3: Detail visualization of MATS outputs when 21 days were used. ......... 140

Figure 6-4: Detail visualization of MATS outputs when 153 days were used. ........ 141

Figure 7-1: Modeled 2009 daily maximum 8-hr ozone at the Confederate Avenue 

site,.......................................................................................................................... 145

Figure 7-2: Modeled 2009 daily maximum 8-hr ozone at the Confederate Avenue146

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

LIST OF TABLES 

Table E-1: Atlanta attainment test results for 2009 based on four different test 

configurations........................................................................................................................ 7

Table 1-1: Subpart 2 Classifications and Attainment Dates.................................................. 22

Table 1-2: Georgia Counties Considered in this Analysis....................................................... 24

Table 1-3: 2001-2003 ozone design values for Atlanta nonattainment area sites ................. 28

Table 1-4: SIP Infrastructure Elements .................................................................................. 28

Table 1-5: SIP Requirements for Moderate Nonattainment Areas ...................................... 29

Table 2-1: Yearly 4th highest 8-hour ozone concentrations (ppm) at the 11 Atlanta 

nonattainment area sites during 1996-2006...................................................................... 34

Table 2-2: Number of exceedances of the ozone NAAQS at the 11 Atlanta nonattainment 

area sites during 1996-2006................................................................................................ 35

Table 2-3: Ending year 8-hour ozone design-values (ppm) .................................................... 35

Table 2-4: Concentrations of NOx, VOCs and meteorological conditions associated with 

various ozone levels at the Tucker PAMS site.................................................................. 41

Table 2-5: Concentrations of NOx, VOCs and meteorological conditions associated with 

various ozone levels at the South-DeKalb PAMS site...................................................... 41

Table 2-6: Concentrations of NOx, VOCs and meteorological conditions............................. 42

Table 2-7: Concentrations of NOx, VOCs and meteorological condition .............................. 42

Table 2-8: Interpretation of Extent of Reaction....................................................................... 43

Table 2-9: Weekday/weekend differences in daytime (6am-7pm) NOx and VOC (TNMOC) 

concentrations at the four Atlanta PAMS sites during 1997-2005 ................................. 46

Table 3-1: Vertical Layer Definition For MM5 and CMAQ.................................................. 59

Table 3-2: Summary of ozone season daily NOX emissions in 2002 and 2009 by source 

categories for 20 counties in Atlanta. ................................................................................ 62

Table 3-3: Summary of ozone season daily VOC emissions in 2002 and 2009 by source 

categories for 20 counties in Atlanta. ................................................................................ 63

Table 3-4: Summary of ozone season daily NOX emissions (tons/day) in 2002 and 2009 for 

major EGU point sources in and around the Atlanta nonattainment counties ............ 65

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 3-5: Major non-EGU point sources in the Atlanta nonattainment counties with NOx 

emissions larger than 100 tons/year .................................................................................. 66

Table 3-6: Summary of ozone season daily NOX and VOC emissions (tons/day) in 2002 and 

2009 by onroad mobile sources in Atlanta 20 counties.................................................... 68

Table 4-1: Mathematical Formulation of Statistical Metrics Used for Evaluating Mesoscale 

Meteorological Model Performance.................................................................................. 74

Table 4-2: Statistical Benchmarks for Mesoscale Meteorological Models............................ 74

Table 4-3: Monthly averaged statistics for the region of the 12-km modeling domain in and 

around Georgia. .................................................................................................................. 77

Table 4-4: Performance Statistics.............................................................................................. 80

Table 4-5: Mean Normalized Bias and Mean Normalized Gross Error for 8-hour ozone 

from CMAQ 12km simulations temporally averaged from May 1, 2002 to September 

30, 2002 (8-hour O3 > 0 ppb and 8-hour O3 > 60 ppb)..................................................... 82

Table 4-6: Mean Normalized Bias and Mean Normalized Gross Error for 1-hour ozone 

from CMAQ 12km simulations temporally averaged from May 1, 2002 to September 

30, 2002 (O3 > 0 ppb and O3 > 60 ppb).............................................................................. 83

Table 4-7: Mean Normalized Bias and Mean Normalized Gross Error of daily maximum 1-

hour ozone from CMAQ 12km simulations temporally averaged from May 1, 2002 to 

September 30, 2002 (1-hour O3 > 60 ppb and 8-hour O3 > 60 ppb). .............................. 83

Table 4-8: Mean Observation (MO), Mean Prediction (MP), Ratio of the Means (RATIO), 

Mean Bias (BIAS), Normalized Mean Bias (NMB), Mean Fractional Bias (FBIAS), 

Mean Error (ERR), Normalized Mean Error (NME), Mean Fractional Error 

(FERROR), and Correlation Coefficient (r) of 8-hour ozone from CMAQ 12km 

simulation temporally averaged from May 1, 2002 to September 30, 2002 (8-hour O3 > 

60 ppb).................................................................................................................................. 84

Table 5-1: NOx Emissions for 20 County Nonattainment Area – Part 1 ............................ 103

Table 5-2: NOx Emissions for 20 County Nonattainment Area – Part 2 ........................... 103

Table 5-3: VOC Emissions for 20 County Nonattainment Area – Part 1........................... 104

Table 5-4: VOC Emissions from for 20 County Nonattainment Area – Part 2 ................. 104

Table 5-5: Georgia Rule 391-3-1-.02(2) Stationary Source VOC Standards for Point, Area, 

and Mobile Sources........................................................................................................... 105

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The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 5-6: Georgia Rule 391-3-1-.02(2) Stationary Source NOx Standards for Point and 

Area Sources...................................................................................................................... 107

Table 5-7: Specific Large Point Source Control Measure – Lafarge Building Materials, 

Inc. ...................................................................................................................................... 108

Table 5-8: Specific Large Point Source Control Measure – Transco Compressor Station 

120....................................................................................................................................... 108

Table 5-9: Specific Large Point Source Control Measure – Caraustar Industries, Inc.... 109

Table 5-10: Federal Control Measures for On-Road Mobile Sources................................ 111

Table 5-11: State Authority to Implement Federal Control Measures for On-Road Mobile 

Sources............................................................................................................................... 112

Table 5-12: Federal Control Measures for On-Road Mobile Sources................................ 114

Table 5-13: Clean Air Campaign in Metro Atlanta Region................................................. 123

Table 6-1: Atlanta attainment test results for 2009, using the maximum value in the 3x3 

array surrounding each site ............................................................................................. 132

Table 6-2: Atlanta attainment test results for 2009 using the monitor grid cell value....... 134

Table 6-3: Atlanta attainment test results for 2009, using a three-year DVB and the 

maximum value in the 3x3 array surrounding each site ............................................... 135

Table 6-4: Atlanta attainment test results for 2009 using a three-year DVB and the monitor 

grid cell value..................................................................................................................... 135

Table 6-5: Atlanta attainment test results for 2009 ............................................................... 142

Table 7-1: Summary of sensitivity analysis results for the Atlanta Confederate Avenue site 

(AIRS ID 13-121-0055) ..................................................................................................... 145

Table 8-1: Multipollutant Control Requirements for Certain Coal-Fired Boilers............ 151

Table 9-1: Total 20-County 2009 Motor Vehicle Emissions Budgets.................................. 154

Table 9-2: 2009 20-County Atlanta Nonattainment Area Projected Emissions ................ 154

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act.......... 159

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act.......... 166

Table 10-3: Source Categories Covered Section 182(b)(2)(C) of the Clean Air Act.......... 172

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or 

Exceed 100 tons per year.................................................................................................. 174

18 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

LIST OF APPENDICES

Appendix Title 

A County-Level Emission Summary Tables for Georgia 

B Observed and Modeled Spatial Distribution of Daily 8-Hour 

Maximum Ozone 

C Daily Maximum 8-Hour Ozone, 1-Hour Ozone, NO, and NO2 

Barplots 

D Scatter Plots of Hourly 8-Hour Ozone, 1-Hour Ozone, NO, and 

NO2 

E Time Series Plots of Hourly 8-Hour Ozone, 1-Hour Ozone, and 

Precursor Species 

F Sensitivity of Ozone in Atlanta to Reductions in NOx and VOC 

Emissions 

G Clean Air Markets - EGU NOx Data 

H Sensitivity of Ozone in Macon to Reductions in NOx Emissions 

from Various Sources in Georgia 

I Protocol for Annual MM5 Modeling in Support of VISTAS 

J MM5 2002 Modeling in Support of VISTAS 

K Documentation of VISTAS Inventories and Georgia 2002 CERR 

Inventory 

L Guidance on the Use of Models and Other Analysis for 

Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, 

and Regional Haze 

M Comments on Guidance on the Use of Models and Other Analysis 

for Demonstrating Attainment of Air Quality Goals for Ozone, 

PM2.5, and Regional Haze 

N Modeling Protocol for the Atlanta, GA 

8-hour Ozone Nonattainment Area 

O VISTAS CEM Emission Rate Memo 

P Quality Assurance Project Plan (Draft) For Association for 

Southeastern Integrated Planning (ASIP) 

Q Hartsfield-Jackson Atlanta International Airport, Reduction in 

Emissions of Ozone Precursors 

R Georgia MM5 Meteorological Model Performance Evaluation 

S.1 May 11, 2006 Letter to EPA Requesting Concurrence of I/M 

Applicability 

S.2 May 31, 2006 Letter from EPA Concurring 

T Voluntary Reduction of Emissions from Railyards in Metro 

Atlanta Region 

U Mobile Source Emissions Modeling 

for Atlanta Ozone Attainment Demonstration 

Motor Vehicle Emissions Budgets 

V MATS Input/Output Files 

19 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

1.0 INTRODUCTION 

This document, entitled Georgia's State Implementation Plan for the Atlanta 8-Hour 

Ozone Nonattainment Area, presents the Georgia Environmental Protection Division’s 

(EPD) plan for attaining the 8-hour ozone standard by June 15, 2010 in the Atlanta 

metropolitan area. This document presents Georgia EPD’s regulatory requirements and 

supporting information in accordance with section 110 of the 1990 Clean Air Act 

Amendments (CAAA) and Title 1 Subpart D of the CAAA. 

1.1 Ozone as an Air Pollutant 

Ozone is a colorless gas. Ground level ozone, unlike the other gaseous air pollutants 

(such as oxides of nitrogen, sulfur dioxide, carbon monoxide) is not a primary pollutant. 

This means that ozone is not directly emitted by any sources, mobile or stationary. 

Ozone forms through a complex series of chemical reactions, which take place in the 

presence of strong sunlight (photochemical reactions). For these reactions to take place, 

certain ingredients (precursors) must be available. Since the reactions must take place in 

the presence of strong sunlight, ozone concentrations have a strong diurnal pattern. 

As shown in Figure 1-1, the precursors to ozone formation are oxides of nitrogen (NOx) 

and reactive organic substances (sometimes referred to as volatile organic compounds 

(VOCs) or hydrocarbons. Examples of such reactive organic substances include 

hydrocarbons found in automobile exhaust (like benzene and propane), vapors from 

cleaning solvents (like toluene), and biogenic emissions (like terpenes). Ozone, when 

mixed with particles and other pollutants, such as NO2 forms smog, a brownish, acrid 

mixture. This type of pollution first gained attention in the 1940's as Los Angeles 

photochemical "smog." Since then, photochemical smog has been observed frequently in 

many other cities. 

20 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 1-1: Diagram Illustrating Ozone Formation 

Historically, the official “ozone season” is Georgia is March 1 through October 31 for 

each calendar year for ambient monitoring requirements. Implementation of some ozone 

control measures are required May 1 through September 30 for each calendar year. The 

reason for the shorter season is that long periods of strong sunlight and warm 

temperatures are needed for ozone formation. Most urban areas experience high levels of 

ground level ozone during the summer months (generally May through September for 

Georgia). With that in mind, ozone is predominantly a summertime air pollutant. 

Changing weather patterns contribute to yearly differences in ozone concentrations from 

region to region. Ozone and the pollutants that form ozone also can be transported into 

an area from pollution sources found hundred of miles upwind. 

Breathing ozone can trigger a variety of health problems including chest pain, coughing, 

throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. 

Ground-level ozone can also reduce lung function and inflame the linings of the lungs. 

Repeated exposure may permanently scar lung tissue. 

Ground-level ozone also damages vegetation and ecosystems. Ground-level ozone is 

absorbed by the leaves of plants, where it can 1) interfere with the ability of sensitive 

plants to store and produce food (which can lead to reduced growth, biomass production 

and/or yields), 2) make sensitive plants more susceptible to certain diseases, insects, or 

harsh weather, other pollutants, and competition, 3) reduce or change the diversity of 

plant species (which can lead to damage to ecosystems dependent on those species, 4) 

visibly injure the leaves of plants, affecting the appearance of vegetation in national 

parks, recreation areas, and cities. 

21 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

1.2 Ozone as a National Ambient Air Quality Standard 

The Clean Air Act (CAA) establishes a process for air quality management through the 

National Ambient Air Quality Standards (NAAQS). Area designations are required after 

promulgation of a new or revised NAAQS. In 1979, the U.S. Environmental Protection 

Agency (EPA) promulgated the 0.12 parts per million (ppm) 1-hour ozone standard (44 

FR 8202, February 8, 1979). On July 18, 1997, EPA promulgated a revised ozone 

standard of 0.08 ppm, measured over an 8-hour period, i.e., the 8-hour standard (62 FR 

38856). The 1997 NAAQS rule was challenged by numerous litigants and in May 1999, 

the U.S. Court of Appeals for the D.C. Circuit issued a decision remanding, but not 

vacating, the 8-hour ozone standard. Among other things, the Court recognized that the 

U.S. EPA is required to designate areas for any new or revised NAAQS in accordance 

with the CAA. The U.S. EPA sought review of two aspects of that decision in the U.S. 

Supreme Court. In February 2001, the Supreme Court upheld EPA's authority to set the 

NAAQS and remanded the case back to the D.C. Circuit for disposition of issues the 

Court did not address in its initial decision. The Supreme Court also remanded the 8-

hour implementation strategy to EPA. In March 2002, the D.C. Circuit rejected all 

remaining challenges to the 8-hour ozone standard. 

The process of designations following promulgation of a NAAQS is contained in section 

107(d) of the CAA. For the 8-hour ozone NAAQS, the Transportation Equity Act for the 

21st Century (TEA-21) extended by 1 year the time for EPA to designate areas for the 8-

hour ozone NAAQS. Thus, EPA was required to designate areas for the 8-hour NAAQS 

by July 2000. However, U.S. House Bill HR3645 (EPA's appropriation bill in 2000) 

restricted EPA's authority to spend money to designate areas until June 2001 or the date 

of the Supreme Court ruling on the standard, whichever came first. As noted earlier, the 

Supreme Court decision was issued in February 2001. In 2003, several environmental 

groups filed suit in district court claiming the U.S. EPA had not met its statutory 

obligation to designate areas for the 8-hour ozone NAAQS. The U.S. EPA entered into a 

consent decree, which required EPA to issue designations by April 15, 2004. 

EPA promulgated designations on April 30, 2004 (69 FR 23858 through 23951), and 

EPA created six classifications of nonattainment for the 8-hour ozone standard as 

specified in Table 1-1. 

Table 1-1: Subpart 2 Classifications and Attainment Dates 

Classification Ozone Design Value Range 

(ppm) 

Attainment Date 

Marginal 0.085 up to 0.092 June 15, 2007 

Moderate 0.092 up to 0.107 June 15, 2010 

Serious 0.107 up to 0.120 June 15, 2013 

Severe 15 0.120 up to 0.127 June 15, 2019 

Severe 17 0.127 up to 0.187 June 15, 2021 

Extreme 0.187 and above June 15, 2024 

22 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

1.3 Regulatory History of Atlanta's Smog Problem 

Pursuant to the Clean Air Act Amendments of 1990 (CAAA), the Atlanta area was 

designated as nonattainment for the 1-hour ozone NAAQS by U.S. EPA and was 

classified as a serious nonattainment area on November 6, 1991. The nonattainment area 

(NAA) was at that time geographically defined as the following 13 Georgia counties: 

Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, 

Henry, Paulding, and Rockdale. Because Atlanta failed to attain the 1-hour ozone 

NAAQS by November 15, 1999, EPA issued a final rulemaking action in the September 

26, 2003, Federal Register (68 FR 55469) determining that, by operation of law, the 

Atlanta area was being reclassified as a "severe" ozone nonattainment area effective 

January 1, 2004. In addition to having been required to submit state implementation plan 

(SIP) revisions meeting requirements for marginal, moderate, and serious ozone 

nonattainment areas, Georgia was required to submit plans meeting the additional 

requirements for areas classified as severe. As a result of EPA's implementation of the 

original federal Clean Air Act of 1970, the Clean Air Act Amendments of 1977, and the 

Clean Air Act Amendments of 1990, EPD has completed, and EPA has approved (67 FR 

30574), SIP revisions to address the 1-hour ozone Atlanta NAA. 

On February 1, 2005, EPD requested under the CAAA of 1990 that the Atlanta area be 

redesignated from nonattainment to attainment with respect to the 1-hour ozone NAAQS. 

This request was based on three years, 2002 through 2004, of ambient monitoring data at 

all 11 ozone monitors in the Atlanta NAA showing no violation of the 1-hour ozone 

NAAQS; the implementation of permanent and enforceable reductions in ozone precursor 

emissions; compliance with all applicable requirements; and the Atlanta Maintenance 

Plan with projections demonstrating that the 2002 emission levels in this area will not be 

exceeded through at least the year 2015. EPD also petitioned EPA to make a 

determination that the Atlanta area was eligible for application of EPA's Clean Data 

Policy, based on the Atlanta area's attainment of the 1-hour ozone NAAQS. EPA 

approved the plan and redesignation request effective June 14, 2005 (70 FR 34660). 

1.4 Nonattainment Area Designation for 8-Hour Ozone in Atlanta 

The process for designations following promulgation of a NAAQS is contained in CAA 

Section 107(d)(1). This section of the Act provides each State Governor an opportunity 

to recommend attainment/unclassifiable or nonattainment designations including 

appropriate boundaries to EPA and for EPA to make modifications to these designations 

and boundaries as it deems necessary. EPD reviewed guidance provided by the EPA as 

well as pertinent, available data to develop criteria for assigning area designations and 

boundaries. The EPA's March 28, 2000, memorandum "Boundary Guidance on Air 

Quality Designations for the 8-Hour Ozone National Ambient Air Quality Standard 

(NAAQS)" delineates the EPA's position that any monitored violation of the standard 

within a Metropolitan Statistical Area (MSA)1

 should, as an initial presumption, cause 

that entire MSA to be considered for designation as nonattainment. 

 

1

(based on Census 1990, http://www.census.gov/population/estimates/metro-city/99mfips.txt) 

23 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

The CAA defines a nonattainment area as any area that does not meet (or that contributes 

to ambient air quality in a nearby area that does not meet) the primary or secondary 

NAAQS. EPA guidance indicates that Georgia should use the larger of the MSA or the 

1-hour ozone NAA as the presumptive boundary for the 8-hour ozone NAAQS. Table 1-

2 specifies the Georgia counties considered in this analysis. Figure 1-2 illustrates the 

location of ozone ambient monitors within the Atlanta nonattainment area. 

Table 1-2: Georgia Counties Considered in this Analysis 

County 

Atlanta 

MSA? 1-hour Ozone 

NAA 

Contributing to 

1-hour ozone 

NAA 

Considered for 

8-hour Ozone 

NAA? 

Banks No No Yes Yes 

Barrow Yes No Yes Yes 

Bartow Yes No Yes Yes 

Butts No No Yes Yes 

Carroll Yes No Yes Yes 

Chattooga No No Yes Yes 

Cherokee Yes Yes Yes Yes 

Clarke No No No Yes 

Clayton Yes Yes NA Yes 

Cobb Yes Yes NA Yes 

Coweta Yes Yes NA Yes 

Dawson No No Yes Yes 

DeKalb Yes Yes NA Yes 

Douglas Yes Yes NA Yes 

Fayette Yes Yes NA Yes 

Floyd No No Yes Yes 

Forsyth Yes Yes NA Yes 

Fulton Yes Yes NA Yes 

Gordon No No Yes Yes 

Gwinnett Yes Yes NA Yes 

Hall No No Yes Yes 

Haralson No No Yes Yes 

Heard No No Yes Yes 

Henry Yes Yes NA Yes 

Jackson No No Yes Yes 

Jasper No No Yes Yes 

Jones No No Yes Yes 

Lamar No No Yes Yes 

Lumpkin No No Yes Yes 

Madison No No Yes Yes 

Meriwether No No Yes Yes 

Morgan No No Yes Yes 

Monroe No No Yes Yes 

24 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-2: Georgia Counties Considered in this Analysis 

County 

Atlanta 

MSA? 1-hour Ozone 

NAA 

Contributing to 

1-hour ozone 

NAA 

Considered for 

8-hour Ozone 

NAA? 

Newton Yes No Yes Yes 

Oconee No No Yes Yes 

Paulding Yes Yes NA Yes 

Pickens Yes No Yes Yes 

Pike No No Yes Yes 

Polk No No Yes Yes 

Putnam No No Yes Yes 

Rockdale Yes Yes NA Yes 

Spalding Yes No Yes Yes 

Troup No No Yes Yes 

Upson No No Yes Yes 

Walton Yes No Yes Yes 

25 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Cherokee

13-121-0055 

(Conf. Ave)

13-089-3001 

(Tucker)

13-089-0002 

(S.DeKalb)

13-223-0003 

(Yorkville)

13-067-0003 

(Kennesaw)

13-247-0001 

(Conyers)

13-077-0002 

(Newnan)

13-113-0001 

(Fayetville ) 13-151-0002 

(McDonough )

13-097-0004 

(Douglasville)

13-135-0002 

(Lawrenceville )

13-121-0055 

(Conf. Ave)

13-089-3001 

(Tucker)

13-089-0002 

(S.DeKalb)

13-223-0003 

(Yorkville)

13-067-0003 

(Kennesaw)

13-247-0001 

(Conyers)

13-077-0002 

(Newnan)

13-113-0001 

(Fayetville ) 13-151-0002 

(McDonough )

13-097-0004 

(Douglasville)

13-135-0002 

(Lawrenceville )

13-121-0055 

(Conf. Ave)

13-089-3001 

(Tucker)

13-089-0002 

(S.DeKalb)

13-223-0003 

(Yorkville)

13-067-0003 

(Kennesaw)

13-247-0001 

(Conyers)

13-077-0002 

(Newnan)

13-113-0001 

(Fayetville ) 13-151-0002 

(McDonough )

13-097-0004 

(Douglasville)

13-135-0002 

(Lawrenceville )

Cherokee

Figure 1-2: Location of ozone monitors within the Atlanta 20-county nonattainment 

area 

Georgia EPD utilized existing EPA guidance (as specified in EPA's March 28, 2000 

memorandum) to exclude, or include, counties in the presumptive nonattainment area, 

i.e., the MSA. Georgia's methodology used to arrive at their recommendations was based 

on a set of criteria based on EPA's 11 factors (as specified in EPA's March 28 

memorandum) and input received from other State agencies. The process of specifying 

the nonattainment boundary for Atlanta was explained in detail in Georgia EPD's letter of 

July 17, 2003 in which EPD supplied additional information regarding the selection 

methodology used to arrive at the June 15, 2003, recommendations. The screening 

criteria were: (1) projected 2007 population density exceeding the minimum value that 

corresponds to a monitored violation within an MSA; (2) Projected 2007 nitrogen oxides 

26 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

(NOx) or volatile organic compounds (VOC) emissions density exceeding the minimum 

value that corresponds to a known monitored violation within an MSA; (3) Daily 

commuting trips (year 2000) basis from a county into the nonattainment area exceeding 

the minimum number of daily in-commutes for an existing nonattainment county; and (4) 

Summer daily non-interstate vehicle miles traveled (VMT) exceeding the minimum 

summer daily non-interstate VMT for an existing nonattainment county (year 2001 

basis). 

Georgia EPD submitted its nonattainment area designation recommendations under the 8-

hour ozone standard to EPA on July 15, 2003. Georgia recommended the following 

counties be designated nonattainment for the 8-hour ozone standard: Barrow, Bartow, 

Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, 

Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and Walton. Georgia 

recommended that Pickens County be excluded from the nonattainment designation even 

though the county is part of the Atlanta MSA. Georgia based this exclusion, in part, on 

the fact that the county did not exceed any of the State's criteria for inclusion into a 

nonattainment area. Other parameters used in the analysis included the county's 

population and annual NOx and VOC emissions. EPA concurred with Georgia's 

recommendations in a letter dated December 3, 2003. 

 On April 30, 2004, EPA designated 20 metropolitan Atlanta counties as a "marginal" 

nonattainment area under the 8-hour ozone standard. The eight-hour ozone 

nonattainment area encompasses the 13 counties of the former 1-hour ozone 

nonattainment area plus seven additional "ring" counties: Barrow, Bartow, Carroll, Hall, 

Newton, Spalding, and Walton. With an attainment deadline of June 15, 2007, marginal 

areas were required to attain the National Ambient Air Quality Standard (NAAQS) by the 

2006 ozone season. On October 16, 2007, the U.S.EPA published a rulemaking 

proposing its determination that the Atlanta Area did not attain the 8-hour ozone NAAQS 

by June 15, 2007, the applicable attainment date for marginal nonattainment areas. The 

proposed finding was based on ambient air quality data from years 2004, 2005, and 2006. 

The U.S.EPA explained that, consistent with Section 181(b)(2) of the Clean Air Act 

(CAA), when EPA finalizes its determination that the Atlanta Area failed to attain, and 

that requirement becomes effective, the Atlanta Area would be reclassified by operation 

of law to the next highest classification, or “moderate” nonattainment. The U.S.EPA 

further proposed that the State submit the SIP revisions meeting the new moderate area 

requirements as expeditiously as practicable, but no later than June 15, 2010. The 

U.S.EPA finalized this finding on March 6, 2008 [73FR 12013-12017]. 

1.5 8-Hour Ozone Design Values in Atlanta

Ozone design-values (DV; three year average of the 4th highest reading per year) for the 

2001-2003 period, which was used in designating the Atlanta 20 county area as 

nonattainment, show that 10 out of the 11 sites exceed the 8-hour ozone NAAQS (0.08 

ppm) (Table 1-3). Due to EPA's rounding and truncation convention, any DV less than 

or equal to 0.084 ppm is considered attaining the NAAQS while any DV greater than or 

equal to 0.085 ppm is considered not attaining the NAAQS. 

27 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-3: 2001-2003 ozone design values for Atlanta nonattainment area sites 

Site name AIRS ID 2001-2003 DV (ppm) 

Confederate Ave. 13-121-0055 0.091 

Conyers 13-247-0001 0.089 

Douglasville 13-097-0004 0.091 

Fayetteville 13-113-0001 0.083 

Kennesaw 13-067-0003 0.090 

Lawrenceville 13-135-0002 0.085 

McDonough 13-151-0002 0.089 

Newnan 13-077-0002 0.087 

South-DeKalb 13-089-0002 0.087 

Tucker 13-089-3001 0.089 

Yorkville 13-223-0003 0.089 

1.6 SIP Requirements for Moderate Nonattainment Areas 

Section 110(a) of the CAA requires states to submit an implementation plan to the 

U.SEPA that provides for implementation, maintenance, and enforcement of NAAQS. 

Section 110(a)(2) lists the elements that are to comprise the implementation plan. 

Several of the elements in section 110(a)(2) specifically address the need for state to 

demonstrate the ability to implement, maintain, and enforce the air quality standards. 

These elements are sometimes referenced as “infrastructure” elements. 

The elements of section 110(a)(2) are listed below: 

Table 1-4: SIP Infrastructure Elements 

Federal CAA Description Found Where in Plan? 

110(a)(2)(A) Enforceable emission limitations 

and other control measures 

Chapters 5, 10, and 11 

110(a)(2)(B) Air quality monitoring, 

compilation, data analysis, and 

reporting 

Chapter 11 

110(a)(2)(C) Enforcement and Stationary 

Source Permitting 

Chapter 11 

110(a)(2)(D) Interstate Transport Chapter 11 

110(a)(2)(E) Resources, conflict of interest, 

and emergency backstop 

Chapter 11 

110(a)(2)(F) Stationary source emissions 

monitoring and reporting 

Chapter 11 

110(a)(2)(G) Emergency powers and 

contingency plans 

Chapter 11 

110(a)(2)(H) SIP revision for revised air 

quality standards or new 

attainment methods 

Chapter 11 

110(a)(2)(I) SIP revisions for new 

nonattainment areas 

See Table 1.5 

110(a)(2)(J) Consultation and public Chapter 11 

28 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-4: SIP Infrastructure Elements 

notification 

110(a)(2)(K) Air quality modeling and 

reporting 

Chapters 2, 3, 4, 6, and 7 

110(a)(2)(L) Major stationary source 

permitting fees 

Chapter 11 

110(a)(2)(M) Consultation with local entities Chapter 11 

Section 110(a)(2)(I) of the CAA pertains to a required SIP revision for an area designated 

as a nonattainment area and this section required that the SIP revision meet the applicable 

requirements of part D of the CAA as it relates to nonattainment areas. The applicable 

requirements of part D of the CAA, in this case, are specified in sections 172(c), 182(a), 

and 182(b). The applicable part D requirements are specified in Table 1-5. 

Table 1-5: SIP Requirements for Moderate Nonattainment Areas 

Requirements Federal 

CAA Description Found Where in Plan? 

172(c)(1) Provide for the implementation of 

RACM as expeditiously as practicable 

(including such reductions in 

emissions from existing sources in the 

area as may be obtained through the 

adoption, at a minimum, of RACT) 

and shall provide for attainment of the 

primary NAAQS 

Chapter 10 

172(c)(2) Provide for Reasonable Further 

Progress 

Chapter 8.2 

172(c)(3) Provisions shall include a 

comprehensive current inventory of 

actual emissions from all sources of 

the relevant pollutant or pollutants in 

such area, including periods revisions 

as determined necessary. 

Chapter 8.3 

172(c)(4) Plan shall expressly identify and 

quantify the emissions of any such 

pollutant(s) which will be allowed in 

accordance from section 172(a)(1)(B) 

from the construction and operation of 

major new or modified stationary 

sources in each such area. Emissions 

quantified for this purpose will be 

consistent with the achievement of 

RFP and will not interfere with 

attainment of the applicable NAAQS. 

Chapter 8.6 and 11 

Nonattainment 

Area (NAA) 

Plan: General 

Requirements 

172(c)(5) Plan shall require permits for the 

construction of new or modified major 

stationary sources as applicable. 

Chapters 8.6 and 11 

29 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-5: SIP Requirements for Moderate Nonattainment Areas 

Requirements Federal 

CAA Description Found Where in Plan? 

172(c)(6) Plan shall include enforceable 

emission limitations and such other 

control measures, means or techniques 

as well as schedules and timetables for 

compliance as deemed necessary to 

provide for attainment of the 

applicable NAAQS. 

Chapters 5 and 10 

172(c)(7) Shall meet the applicable provisions of 

section 110(a)(2). 

Chapters 8.9 and 11 

172(c)(8) Administrator may allow the use of 

equivalent modeling, emission 

inventory, and planning procedures. 

Chapter 8.10 

172(c)(9) Plan shall provide for the 

implementation of specific measures 

to be undertaken if the area fails to 

make RFP or to attain the applicable 

NAAQS. Such measures shall be 

included in the plan revision as 

contingency measures to take effect in 

any such case without further action 

by the State/Administrator. 

Chapter 8.11 

182(a)(1) Within 2 years after the date of 

enactment of the 1990 CAAA, (in this 

case designation)the plan shall provide 

for a comprehensive current inventory 

of actual emissions from all sources as 

described in section 172(c)(3). 

Chapter 8.3 

[see 6/15/2006 letter] 

182(a)(2)(A) Plan shall provide corrections to the 

state implementation plan to correct 

requirements in (or add requirements 

to) the plan for reasonable available 

control technology (RACT) as 

required under section 172(b) as in 

effect immediately before the date of 

enactment of the CAAA’s of 1990) as 

interpreted in guidance issued by the 

Administrator under section 108 

before the date of enactment of the 

CAAA’s of 1990. 

Chapter 10 

182(a)(2)(B) Plan shall provide corrections to the 

state implementation plan to include a 

savings clause implementation of a 

vehicle emission control inspection 

and maintenance (I/M) program no 

less stringent that that already 

included I the plan. 

Chapter 8.7 

NAA Plan: 

Marginal Area 

Requirements 

182(a)(2)(C) Plan shall provide for a permit 

program in accordance with sections 

172(c)(5) and 173. 

Chapters 8.6 and 11 

30 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-5: SIP Requirements for Moderate Nonattainment Areas 

Requirements Federal 

CAA Description Found Where in Plan? 

182(a)(3) Plan shall provide for a general 

periodic emissions inventory every 

three years until area is redesignated 

to attainment. Plan shall also provide 

for an annual emissions inventory for 

sources 25 tpy or greater of VOC or 

NOx. 

Chapter 8.5 

NAA Plan: 

Moderate Area 

Requirements 

182(b)(1) Mandates a 15% VOC emission 

reduction, accounting for growth, in 

the first 6 years after the baseline year 

(2002) for moderate and above ozone 

NAAs. 

Chapter 8.2 

31 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-5: SIP Requirements for Moderate Nonattainment Areas 

Requirements Federal 

CAA Description Found Where in Plan? 

182(b)(2) 

(A) 

(B) 

(C) 

The State shall submit a revision to the 

applicable implementation plan to 

include provisions to require the 

implementation of RACT under 

section 172(c)(1) with respect to each 

of the following: (A), (B) and (C). 

Each category of VOC sources in the 

area covered by a CTG document 

issued by the Administrator between 

the date of the enactment of the 

CAAA’s of 1990 and the date of 

attainment. Each revision described in 

subparagraph (A) shall be submitted 

within the period set forth by the 

Administrator in issuing the relevant 

CTG document. 

All VOC sources in the area covered 

by any CTG issued before the date of 

the enactment of the CAAA’s of 1990. 

The revision with respect to sources 

described in subparagraph (B) shall be 

submitted by 2 years after the date of 

enactment of the CAAA’s of 1990, 

and shall provide for the 

implementation of the required 

measures as expeditiously as 

practicable but no later than May 31, 

1995. 

All other major stationary sources of 

VOCs that are located in the area. The 

revision with respect to sources 

described in subparagraph (C) shall be 

submitted by 2 years after the date of 

enactment of the CAAA’s of 1990, 

and shall provide for the 

implementation of the required 

measures as expeditiously as 

practicable but no later than May 31, 

1995. 

Chapter 5 and Chapter 10 

32 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 1-5: SIP Requirements for Moderate Nonattainment Areas 

Requirements Federal 

CAA Description Found Where in Plan? 

182(b)(3) Plan shall provide requirements for 

applicable owners/operators of 

gasoline dispensing systems to install 

and operate a system for gasoline 

vapor recovery of emissions from the 

fueling of motor vehicles. 

Not required for moderate 

ozone nonattainment areas 

as per section 202(a)(6). 

182(b)(4) Plan shall provide for a vehicle 

inspection and maintenance program 

(I/M) as required by section 

182(a)(2)(B). 

Chapter 8.7 

182(b)(5) The emission offset requirements are 

the ratio of total emission reductions 

of VOCs to total increase of emissions 

of VOCs shall be at least 1.15 to 1. 

8.6 

33 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

2.0 CONCEPTUAL DESCRIPTION OF 8-HOUR OZONE 

LEVELS IN ATLANTA AND GEORGIA 

To analyze the spatial patterns in ozone concentrations throughout the Atlanta 

nonattainment area, the yearly 4th highest 8-hour ozone concentration and number of 

exceedances of the NAAQS from 1996-2006 were investigated (Table 2-1, 2-2). These 

data indicate that peak 8-hour ozone concentrations typically occur at the center (urban 

core) of the nonattainment area, represented here by the Confederate Avenue site. This 

site exhibited the highest ozone concentration (4th highest value) in six out of the eleven 

years analyzed, and recorded the highest number of exceedances in seven out of the 

eleven years. Other sites in which peak concentrations and number of exceedances were 

recorded are the Conyers, Douglasville, Lawrenceville, and McDonough sites, all 

representing suburban sites, downwind of peak precursor emissions. Analyzing ozone 

DVs (three year average of the 4th highest reading per year) (Table 2-3), also indicates 

that the Confederate Avenue site consistently exhibits the highest DV within the 

nonattainment area. However, despite most violations occurring at the Confederate 

Avenue site near downtown Atlanta, it is important to note that all of the 11 sites within 

the nonattainment area continuously record violations of the ozone NAAQS, hence the 

problem is not limited to a specific site or subset of sites within the nonattainment area. 

Table 2-1: Yearly 4th highest 8-hour ozone concentrations (ppm) at the 11 Atlanta 

nonattainment area sites during 1996-2006. 

Bold red numbers indicate maximum per year. 

Site name 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 

Conf. Ave. 0.110 0.104 0.126 0.124 0.113 0.084 0.100 0.091 0.089 0.092 0.092 

Conyers 0.098 0.110 0.113 0.123 0.099 0.091 0.099 0.078 0.087 0.088 0.099

Douglasville N/A 0.090 0.110 0.105 0.097 0.092 0.098 0.085 0.080 0.089 0.095 

Fayetteville N/A N/A 0.111 0.113 0.100 0.084 0.088 0.077 0.084 0.086 0.090 

Kennesaw N/A N/A N/A 0.095 0.107 0.088 0.100 0.084 0.073 0.081 0.093 

Lawrenceville 0.089 0.086 0.111 0.103 0.100 0.080 0.089 0.088 0.092 0.082 0.096 

McDonough N/A N/A N/A 0.126 0.111 0.086 0.099 0.082 0.085 0.089 0.095 

Newnan N/A N/A N/A 0.108 0.096 0.085 0.099 0.077 0.083 0.078 0.086 

South DeKalb 0.102 0.092 0.112 0.112 0.107 0.085 0.095 0.083 0.084 0.087 0.096 

Tucker 0.100 0.085 0.111 0.111 0.107 0.088 0.090 0.091 0.088 0.084 0.094 

Yorkville 0.092 0.086 0.104 0.103 0.088 0.085 0.099 0.083 0.073 0.082 0.084 

34 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 2-2: Number of exceedances of the ozone NAAQS at the 11 Atlanta 

nonattainment area sites during 1996-2006. 

Bold red numbers indicate maximum per year. 

Site name 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 

Conf. Ave. 21 24 41 54 22 3 15 4 7 7 11

Conyers 15 24 38 43 11 6 12 1 6 4 10 

Douglasville N/A 9 36 37 13 6 21 4 1 8 8 

Fayetteville N/A N/A 34 30 9 3 6 0 3 4 6 

Kennesaw N/A N/A N/A 8 17 5 12 3 0 2 11 

Lawrenceville 9 6 27 16 12 2 7 6 4 1 8 

McDonough N/A N/A N/A 34 22 4 11 0 5 6 9 

Newnan N/A N/A N/A 33 11 4 9 0 2 0 4 

South DeKalb 15 8 21 28 16 4 10 2 3 7 10 

Tucker 15 4 19 27 16 7 11 5 4 3 8 

Yorkville 10 5 26 23 6 4 11 2 0 2 3 

Table 2-3: Ending year 8-hour ozone design-values (ppm) 

for the 11 Atlanta nonattainment area sites during 1998-2006 (e.g., the 1998 DV is 

based on data from 1996-1998). 

Bold red numbers indicate maximum per year. Bold black (and red) numbers 

indicate an exceedance of the NAAQS (expresses as 0.084 ppm). 

Site name 1998 1999 2000 2001 2002 2003 2004 2005 2006 

Conf. Ave. 0.113 0.118 0.121 0.107 0.099 0.091 0.093 0.090 0.091 

Conyers 0.107 0.115 0.111 0.104 0.096 0.089 0.088 0.084 0.091 

Douglasville N/A 0.101 0.104 0.098 0.095 0.091 0.087 0.084 0.088 

Fayetteville N/A N/A 0.108 0.099 0.090 0.083 0.083 0.082 0.086 

Kennesaw N/A N/A N/A 0.096 0.098 0.090 0.085 0.079 0.082 

Lawrenceville 0.095 0.100 0.104 0.094 0.089 0.085 0.089 0.087 0.090 

McDonough N/A N/A N/A 0.107 0.098 0.089 0.088 0.085 0.089 

Newnan N/A N/A N/A 0.096 0.093 0.087 0.086 0.079 0.082 

South DeKalb 0.102 0.105 0.110 0.101 0.095 0.087 0.087 0.084 0.089 

Tucker 0.098 0.102 0.109 0.102 0.095 0.089 0.089 0.087 0.088 

Yorkville 0.094 0.097 0.098 0.092 0.090 0.089 0.085 0.079 0.079 

Spatial patterns in ozone DVs outside of the Atlanta nonattainment area were also 

investigated, to assess whether ozone levels are impacted by regional factors (such as 

emissions, meteorology), or exhibit a local phenomenon to Atlanta. For this purpose, 

1999-2006 ozone DVs from all monitoring-sites throughout Georgia were grouped to the 

following regions (only sites with continuous ozone records for 1999-2006 were used): 

35 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

1. Atlanta: 11 sites listed in Table 1-3 

2. Macon: Macon south-east monitor (AIRS ID 13-021-0012) 

3. Columbus: Columbus Airport (13-215-0008) and Columbus Crime lab (13-215-

1003) monitors 

4. Augusta: Augusta 13-245-0091 monitor 

5. Athens: Athens 13-059-00002 monitor 

6. Savannah: Savannah 12-051-0021 monitor 

7. South Coastal Georgia: Brunswick monitor (12-127-0006) 

8. South Central Georgia: Leslie monitor (13-261-1001) 

9. North Georgia Mountains: Fort mountain (13-213-0003) and Dawsonville (13-

085-0001) monitors 

The area-average and area-maximum (single site) DVs for the period of 2001-2006 are 

shown in Figure 2-1. Area-average and area-maximum (single site) count of daily 

exceedances of the NAAQS (expressed as 85 ppb) are shown in Figure 2-2. These data 

seem to exhibit both regional and local patterns in ozone levels in Georgia. A sharp 

decline in both ozone levels and the number of exceedances are observed at all areas 

from 2001 to 2005, followed by a slight increase in the 2006 DV. In addition to this 

regional pattern, a local one is evident in Atlanta, as expressed by higher ozone levels and 

more frequent exceedances compared to any other area of the state. The relatively minor 

differences in ozone levels between Atlanta and Macon as observed in Figure 2-1(a) are 

due to the comparison between an average of 11 monitor for the Atlanta area and a single 

site in Macon. However, when the maximum DV and number of exceedances in the 

Atlanta area are compared to the Macon monitor, larger differences are observed. The 

increment in ozone levels in Atlanta, compared to other areas in the state, can be 

interpreted as a local contribution caused by emissions of ozone precursors in the Atlanta 

area. In fact, previous work has demonstrated that emissions of ozone precursors in 

Atlanta also contribute to ozone formation at Macon and other regions of the state 

(Appendix H). 

36 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

60.0

65.0

70.0

75.0

80.0

85.0

90.0

95.0

100.0

Atlanta

Macon

Columbus

Augusta

Athens

Savannah

S. Coastal GA

S. Central GA

N. GA Mountains

Average O3 DV per geographical area (ppb)

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006

60.0

70.0

80.0

90.0

100.0

110.0

Atlanta

Macon

Columbus

Augusta

Athens

Savannah

S. Coastal GA

S. Central GA

N. GA Mountains 

Highest O3 DV per geographical area (ppb)

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006

(a) 

(b) 

Figure 2-1: (a) Area-average and (b) single-site area-maximum ozone DVs for 2001-

2006. 

37 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

Atlanta

Macon

Columbus

Augusta

Athens

Savannah

S. Coastal GA

S. Central GA

N. GA Mountains

Days per year in which max 8-hr O3 >= 85ppb 

(average per area)

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006

0.0

5.0

10.0

15.0

20.0

25.0

30.0

Atlanta

Macon

Columbus

Augusta

Athens

Savannah

S. Coastal GA

S. Central GA

N. GA Mountains 

Days per year in which max 8-hr O3 >= 85ppb 

(maximum in single site per area)

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006

(a) 

(b) 

Figure 2-2: (a) Area-average and (b) single-site area-maximum number of exceedances of 

the ozone NAAQS level (expressed as 85 ppb) in 2001-2006. 

38 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

The strong (generally) downward trend in ozone DVs throughout the state is of interest, 

and is likely due to a combination of both a decrease in emissions and variations in 

meteorological conditions leading to ozone formation. This can be inferred from Figure 

2-3, in which variations in NOx emissions (both EGU and mobile-sources) and in the 

number of "ozone conducive days" are presented for 1996-2005 (2006 meteorological 

and vehicle miles traveled data were not available at the time of this analysis). State total 

EGU NOx emissions were obtained from the Clean Air Markets Division (CAMD) 

website (http://www.epa.gov/airmarkets/; see also Appendix G). Approximate 13-county 

highway mobile source emissions inventories were calculated by EPD using a modified 

draft version of EPA's National Mobile Inventory Model (NMIM20050311) into which 

"historic" 1994 through 2004 average annual daily vehicle miles traveled (VMT) from 

Georgia Department of Transportation were imported. The 2005 VMT were projected 

through linear regression. The MOBILE6.2.03 emission factors produced by NMIM 

reflect default MOBILE6 speed distributions. Trends in meteorology were quantified 

based on the count of "ozone conducive days" per ozone season. An "ozone conducive 

day" was defined here as a day in which the maximum daily temperature was above the 

75th percentile, and both the average relative-humidity and average wind-speed were 

below the 50th percentile for the period studied (1996-2005, using data from the National 

weather Service station in Atlanta). These parameters were chosen to represent 

meteorological conditions conducive to ozone formation, i.e. hot, dry and stagnant 

conditions. The use of relative (percentile based) rather than absolute thresholds (e.g., 

temperature above 90°F) allows for an easy inter-annual comparison incorporating 

several meteorological parameters. Different thresholds were investigated, resulting in a 

change in the actual number of ozone conducive days per year, but this had little effect on 

the observed trend. Emissions data show a strong decline in EGU NOx emissions in 

Georgia (60% decrease from 1998 to 2005) due to the installation of Selective Catalytic 

Reduction (SCR) devices at several power plants (Bowen Units 1-4, Hammond Unit 4, 

and Wansley Units 1-2) and other controls (such as the use of Powder River Basin coal at 

Scherer Units 1-4, co-firing of natural gas at Plant McDonough and Plant Yates, over-fire 

air at several other units, and low-NOx burners on almost all units). On-road mobile 

source emissions also exhibit a downward trend (32% decrease from 1998 to 2005), 

mainly due to fleet turnover. In addition, there seems to be a substantial amount of 

variability in the meteorological condition between years, with an overall decrease in the 

count of "ozone conducive days" in the last several ozone seasons. The combination of 

these reductions in emissions and more-favorable meteorology in the last several years 

can help in explaining the downward trend in ozone design values. 

39 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

0

100

200

300

400

500

600

700

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

NOx emissions (TPD)

0

5

10

15

20

25

30

35

Number of "ozone conducive" days

EGU NOx (TPD) Mobile-source NOx (TPD) Count of "O3 conducive" days

Figure 2-3: Inter-annual trends in NOx emissions (total Georgia EGU and 13-county 

Atlanta on-road mobile-source emissions) and count of "ozone conducive days" for 

1996-2005. 

2.1 Conditions Leading to Elevated Ozone in the Atlanta Area 

To further study the factors contributing to ozone formation in Atlanta and to the 

occurrence of exceedances of the ozone NAAQS, data from the Photochemical 

Assessment Monitoring Stations (PAMS) network was used. The Atlanta PAMS network 

consists of four sites: Yorkville (type 1, upwind/background site), Tucker (type 2, 

maximum precursor location), South-DeKalb (type 2, maximum precursor location) and 

Conyers (type 3, maximum ozone site). Data from the four PAMS sites were binned, 

according to the daily maximum 8-hour ozone concentration, into the following bins: <65 

ppb, 65-85 ppb, 85-105 ppb, and >105 ppb. Parameters investigated were morning (6-

10am), midday (10am-4pm), and evening (4-7pm) NOx and VOC (sum of 56 PAMS 

VOC species) concentrations, previous day ozone concentrations, and meteorological 

conditions (maximum daily temperature, average daytime wind speed and relative 

humidity). Data from 1997-2003 were analyzed, for days in which the above-mentioned 

parameters were available (Tables 2-4, 2-5, 2-6, and 2-7). Elevated ozone at both the 

'type 2' sites (Tucker and South-DeKalb) and the 'type 3' site (Conyers) are associated 

with elevated previous day ozone, indicating a buildup of ozone during episodes. As 

expected, elevated ozone is also associated with elevated temperatures, low wind speeds 

and low relative humidity, as these meteorological conditions are known to be conducive 

of ozone formation. 

40 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 2-4: Concentrations of NOx, VOCs and meteorological conditions associated 

with various ozone levels at the Tucker PAMS site 

(ozone concentrations reported as daily maximum 8-hour ozone; VOC reported are 

the sum of 56 PAMS target species; morning refers to 6-10am; midday refers to 

10am-4pm; evening refers to 4-7pm; daytime referred to as 6am-7pm) 

Parameter O3

<65ppb 

65ppb ≤ O3

< 85ppb 

85ppb ≤ O3 < 

105ppb 

O3 ≥

105ppb 

Number of days 155 112 36 13 

O3 (ppb) 48.3 73.1 90.8 116.2 

Previous day O3 (ppb) 54.7 70.8 79.4 85.2 

Morning NOx (ppb) 17.7 20.9 34.0 32.7 

Mid-day NOx (ppb) 7.5 6.0 8.0 10.7 

Evening NOx (ppb) 11.5 10.7 13.5 15.9 

Morning VOC (ppbC) 58.8 70.9 95.6 107.0 

Midday VOC (ppbC) 35.5 34.0 36.6 47.0 

Evening VOC (ppbC) 49.5 45.9 59.8 63.1 

Morning VOC/NOx (ppbC/ppb) 4.6 4.2 5.3 3.6 

Midday VOC/NOx (ppbC/ppb) 7.6 8.0 5.1 5.4 

Evening VOC/NOx (ppbC/ppb) 5.4 5.3 4.5 4.7 

Daytime wind speed (m/s) 1.52 1.44 1.21 1.15 

Max. Temperature (°C) 28.5 31.1 32.2 33.1 

Daytime relative humidity (%) 73.5 58.7 53.9 48.5 

Table 2-5: Concentrations of NOx, VOCs and meteorological conditions associated 

with various ozone levels at the South-DeKalb PAMS site 

(ozone concentrations reported as daily maximum 8-hour ozone; VOC reported are 

the sum of 56 PAMS target species; morning refers to 6-10am; midday refers to 

10am-4pm; evening refers to 4-7pm; daytime referred to as 6am-7pm) 

Parameter O3

<65ppb 

65ppb ≤ O3

< 85ppb 

85ppb ≤ O3 < 

105ppb 

O3 ≥

105ppb 

Number of days 272 146 43 15 

O3 (ppb) 45.5 73.3 91.9 113.7 

Previous day O3 (ppb) 51.7 69.0 80.0 88.2 

Morning NOx (ppb) 26.4 45.3 71.5 75.4 

Mid-day NOx (ppb) 5.7 5.2 5.1 6.5 

Evening NOx (ppb) 10.5 14.1 13.8 16.8 

Morning VOC (ppbC) 52.0 83.9 117.7 108.7 

Midday VOC (ppbC) 25.6 25.5 28.8 34.0 

Evening VOC (ppbC) 40.4 43.4 47.6 55.6 

Morning VOC/NOx (ppbC/ppb) 3.9 2.9 2.0 1.9 

Midday VOC/NOx (ppbC/ppb) 7.9 8.2 8.3 7.4 

Evening VOC/NOx (ppbC/ppb) 9.0 7.2 7.5 7.8 

Daytime wind speed (m/s) 1.44 1.26 1.12 1.07 

Max. Temperature (°C) 29.3 31.7 32.9 34.8 

Daytime relative humidity (%) 74.4 61.2 58.2 54.6 

41 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 2-6: Concentrations of NOx, VOCs and meteorological conditions 

associated with various ozone levels at the Conyers PAMS site (ozone concentrations 

reported as daily maximum 8-hour ozone; VOC reported are the sum of 56 PAMS 

target species; morning refers to 6-10am; midday refers to 10am-4pm; evening 

refers to 4-7pm; daytime referred to as 6am-7pm) 

Parameter O3

<65ppb 

65ppb ≤ O3

< 85ppb 

85ppb ≤ O3 < 

105ppb 

O3 ≥

105ppb 

Number of days 146 64 29 11 

O3 (ppb) 47.4 72.9 91.9 110.0 

Previous day O3 (ppb) 52.5 69.6 78.8 98.9 

Morning NOx (ppb) 6.7 10.7 17.1 25.4 

Mid-day NOx (ppb) 2.5 3.4 4.6 5.9 

Evening NOx (ppb) 3.0 3.5 5.6 6.9 

Morning VOC (ppbC) 27.8 44.6 56.2 100.8 

Midday VOC (ppbC) 17.6 22.7 27.5 31.6 

Evening VOC (ppbC) 24.9 32.8 37.3 52.8 

Morning VOC/NOx (ppbC/ppb) 6.6 6.0 4.8 4.5 

Midday VOC/NOx (ppbC/ppb) 10.1 10.5 9.7 8.2 

Evening VOC/NOx (ppbC/ppb) 13.2 16.5 12.2 13.0 

Daytime wind speed (m/s) 1.21 1.39 1.43 1.03 

Max. Temperature (°C) 29.2 31.1 32.8 33.2 

Daytime relative humidity (%) 73.5 62.0 59.4 60.7 

Table 2-7: Concentrations of NOx, VOCs and meteorological condition 

associated with various ozone levels at the Yorkville PAMS site (ozone 

concentrations reported as daily maximum 8-hour ozone; VOC reported are the 

sum of 56 PAMS target species; morning refers to 6-10am; midday refers to 10am4pm; evening refers to 4-7pm; daytime referred to as 6am-7pm) 

Parameter O3

<65ppb 

65ppb ≤ O3

< 85ppb 

85ppb ≤ O3 < 

105ppb 

O3 ≥

105ppb 

Number of days 58 39 2 0 

O3 (ppb) 48.6 73.7 86.0 - 

Previous day O3 (ppb) 50.4 66.3 71.0 - 

Morning NOx (ppb) 2.0 2.4 2.0 - 

Mid-day NOx (ppb) 1.4 1.5 1.0 - 

Evening NOx (ppb) 1.8 1.9 1.2 - 

Morning VOC (ppbC) 16.7 19.8 14.3 - 

Midday VOC (ppbC) 16.7 14.1 12.2 - 

Evening VOC (ppbC) 21.0 25.0 26.4 - 

Morning VOC/NOx (ppbC/ppb) 11.0 13.0 6.9 - 

Midday VOC/NOx (ppbC/ppb) 14.5 11.8 12.2 - 

Evening VOC/NOx (ppbC/ppb) 15.9 19.7 24.3 - 

Daytime wind speed (m/s) 2.65 2.38 3.13 - 

Max. Temperature (°C) 28.4 30.0 31.4 - 

Daytime relative humidity (%) 77.3 63.7 73.0 - 

42 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

To examine the relative importance of precursors of ozone (NOx and VOCs) to ozone 

formations, trends in these precursors were analyzed. Elevated ozone at the SouthDeKalb, Tucker and Conyers are typically associated with elevated levels of both NOx

and VOCs. However, lower ratios of VOC/NOx are typically associated with elevated 

ozone, possibly indicating 'NOx-limited' conditions (ozone formation is limited by the 

amount of available NOx). However, this analysis is a descriptive one, and it is difficult to 

conclude on the relative importance on NOx or VOC based on these data alone. 

2.1.1 Analysis of PAMS data in Atlanta using Ozone M.A.P.P.E.R. 

To further examine the relative importance of NOx and VOC to ozone formation, EPD 

used the Ozone M.A.P.P.E.R. program (Blanchard et al., 1995, 1996). Ozone 

M.A.P.P.E.R. (Measurement-based Analysis of Preferences in Planned Emission 

Reductions) is a Windows-based program that analyzes ozone and other air-quality 

measurements to determine if ground-level ozone formation is limited by the availability 

of the pre-cursor pollutants: VOCs or NOx. Ozone M.A.P.P.E.R. can be used to: (1) 

qualitatively assess the preferential effectiveness of controlling VOC or NOx emissions, 

(2) compare control strategy assessments obtained from the application of grid-based 

photochemical air quality models, and (3) evaluate trends in the relative effectiveness of 

VOC vs. NOx controls. The calculations are carried out according to the equations of the 

Integrated Empirical Rate (IER) model or the Smog Production (SP) algorithm 

(Blanchard et al., 1995, 1996). These equations use measurements of ozone, nitric oxide 

(NO), and either NOx (NO + NO2) or NOy (the sum of all oxidized nitrogen species) to 

compute the extent of reaction. The extent of reaction is a dimensionless parameter 

ranging from zero to one. As the extent of reaction approaches one, ozone production 

ceases because virtually all of the NOx has reacted. Table 2-8 contains a summary of 

how the extent of reaction is typically interpreted. 

Table 2-8: Interpretation of Extent of Reaction 

Extent of Reaction Interpretation 

0.0 – 0.6 Strongly indicative of VOC limitation 

0.6 – 0.9 Transitional to NOx limitation 

0.9 – 1.0 Strongly indicative of NOx limitation 

Ozone M.A.P.P.E.R. should be used as a qualitative indicator of control preferences, 

rather than quantitatively as an estimator of control requirements because: (1) the 

computational algorithms are simple representations of ozone formation in smog 

chambers and do not incorporate many physical processes that are important in affecting 

ozone concentrations in the ambient environment, and (2) bias and imprecision of 

measurements typically result in uncertainties on the order of 0.1 in the extent of reaction. 

43 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

2.1.1.1 Application to Atlanta 

PAMS data was available for four PAMS sites in Atlanta for the ozone seasons (MaySeptember) of 1997-2005. Ozone M.A.P.P.E.R. was applied to each of these PAMS sites 

using the Smog Production (SP) algorithm. The Smog Production algorithm was chosen 

over the Integrated Empirical Rate (IER) model to calculate extent of reaction because it 

is considered to be more advanced and comprehensive. 

NOx data were available at all four PAMS sites (along with ozone and NO), however 

NOy data were only partially available (for 2000-2005 at South DeKalb and Tucker, 1998 

at Conyers, not available for Yorkville). For consistency across sites and years, NOx data 

(rather than NOy) were used in the analysis. 

2.1.1.2 Summary of Ozone M.A.P.P.E.R. Results 

Average diurnal patterns in the extent of reaction (EOR) for the four PAMS sites for the 

period of 1997-2005 are shown in Figure 2-4. The extent of reaction clearly follows a 

diurnal pattern similar to ozone, with peak values in the afternoon and values 

approaching zero during the nighttime. Based on the average diurnal patterns of the 

EOR, formation of ozone during the afternoon (peak ozone) hours is in the 'transitional' 

range (EOR in the range of 0.6-0.9), indicating that both NOx and VOC controls may be 

efficient for reducing ozone levels. Also evident is that the Yorkville and Conyers sites 

are more NOx-limited compared to the two 'type 2' (maximum precursor) sites, Tucker 

and South-DeKalb. 

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

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

Time of day

Extent of reaction

Conyers South-DeKalb Tucker Yorkville

Figure 2-4: Average diurnal pattern in extent of reaction for the four PAMS sites for 

1997-2005 

To further analyze the relative importance of NOx and VOCs to the formation of ozone, 

EOR results were binned according to daily maximum 8-hour ozone concentrations (in 

the ranges of <65 ppb, 65-85 ppb, 85-105 ppb, and >105 ppb). The average diurnal 

patterns associated with each bin at each site were calculated, and are presented in 

44 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figures 2-5. These figures clearly demonstrate that ozone formation becomes more NOxlimited with elevated daily maximum 8-hour ozone concentrations. This is of special 

importance, as the 8-hour ozone NAAQS is a percentile/maximum based standard (4 

highest concentration per year), hence in order to bring the region into attainment of the 

NAAQS, controls that are most efficient in reducing peak ozone concentrations should be 

adopted and implemented. While the data in Figure 2-4 seem to indicate that Atlanta 

ozone is 'transitional' to NOx-limitation, data in Figures 2-5 clearly indicate that days of 

high-ozone are NOx-limited. Hence, NOx controls are likely to be substantially more 

efficient than VOC controls in reducing maximum 8-hour ozone concentrations. The 

apparent discrepancy between the trends in Figure 2-4 and 2-5 are due to the distribution 

of days between the four ozone bins. In all four PAMS sites, the vast majority of days 

(72%-75%) are categorized in the low ozone bin (<65 ppb), while only 4.4%-8.6% of 

days are categorized in the top two bins (>85 ppb). 

a) Yorkville

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Time of day

Extent of reaction

O3<65ppb 65ppb<O3<85ppb

85ppb<O3<105ppb O3>105ppb

b) Tucker

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Time of day

Extent of reaction

O3<65ppb 65ppb<O3<85ppb

85ppb<O3<105ppb O3>105ppb

c) South-DeKalb

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Time of day

Extent of reaction

O3<65ppb 65ppb<O3<85ppb

85ppb<O3<105ppb O3>105ppb

d) Conyers

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Time of day

Extent of reaction

O3<65ppb 65ppb<O3<85ppb

85ppb<O3<105ppb O3>105ppb

Figure 2-5: Average diurnal pattern in extent of reaction for 1997-2005 binned by the 

daily maximum 8-hour ozone concentration (<65ppb, 65-85ppb, 85-105ppb, >105ppb) 

for (a) Yorkville, (b) Tucker, (c) South-DeKalb, and (d) Conyers. 

2.1.1.3 Ozone M.A.P.P.E.R. Conclusions 

The application of Ozone M.A.P.P.E.R. to the four PAMS sites in Atlanta clearly 

indicates that the control of NOx emissions is preferred to VOC emission controls. This 

is especially true for the days of elevated 8-hour ozone concentrations. These results are 

consistent with results from an air-quality model based sensitivity analysis (Appendix F), 

45 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

showing a much greater sensitivity of elevated 8-hour ozone concentrations to NOx

controls than VOC controls, both at core-urban and suburban/rural sites. 

2.2 Weekday/weekend trends in ozone concentrations 

The weekly cycles of ozone are of interest because they provide information about the 

response of ozone to changes in anthropogenic emissions from weekdays to weekends. 

While it is not feasible to conduct ambient experiments with long-term changes in 

precursor emissions, the response of ozone to changes in precursor emissions that occur 

on weekends has ramifications toward its response to long-term strategies to control 

ozone through reductions in precursor emissions. During weekends, the emissions of 

anthropogenic precursors are lower compared to weekdays, because major sources of 

ozone precursors, such as mobile sources and industrial sources, are less active on 

weekends. Data collected at the four Atlanta PAMS sites (Table 2-9) indicate that NOx

concentrations are substantially lower on weekends relative to weekdays, while 

differences in VOC concentrations (expressed here as total non-methane organic 

compounds, TMNOC) are less pronounced. This is due to the fact that some major VOC 

sources, such as biogenic emissions and fuel evaporation, remain constant irrespective of 

the day of the week. For both precursors, the weekend/weekday differences are more 

evident at the maximum precursor sites (Tucker and South-DeKalb) than at the upwind 

(Yorkville) and downwind (Conyers) sites. 

Table 2-9: Weekday/weekend differences in daytime (6am-7pm) NOx and VOC 

(TNMOC) concentrations at the four Atlanta PAMS sites during 1997-2005 

(only days in which both NOx and TNMOC measurements were available are 

included) 

NOx (ppb) VOC (TNMOC, ppbC) Site Weekday Weekend % change Weekday Weekend % change

South-DeKalb 18.9 10.6 -43.8 65.1 49.3 -24.2 

Tucker 15.4 7.6 -50.5 72.6 51.6 -28.9 

Conyers 6.2 4.1 -34.7 34.5 31.3 -9.3 

Yorkville 3.1 2.1 -31.3 24.5 24.6 0.3 

Changes in weekdays/weekend daily maximum 8-hour ozone concentrations are 

presented in Figure 2-6, for all four Atlanta PAMS sites, as well as the Atlanta 

Confederate Avenue site, for the period of 1997-2005, as well as for 3-year periods 

within that range. The Confederate Avenue site is of special interest as its DV has 

consistently been the highest of all the Atlanta monitors throughout the 1998-2005 

period, and due to its location in the center of the nonattainment area (about 2 miles 

south-east of downtown Atlanta). These results indicate that ozone in Atlanta is typically 

lower on the weekends compared to weekdays, which can serve as an additional 

indication to Atlanta ozone being NOx-limited. Of the five sites investigated, Confederate 

Avenue and South-DeKalb seem the least NOx-limited, which is expected given their 

location in the middle of the core urban area (Confederate Avenue) and adjacent to a 

major highway (South-DeKalb, located about 0.8 miles away from I-285). Splitting the 

dataset of ozone concentrations into three 3-year periods (1997-1999, 2000-2002, 2002-

46 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

2005) seems to indicate that Atlanta ozone may have shifted from being VOClimited/NOx-inhibited in the earlier period (1997-1999), as expressed by higher ozone 

concentrations during the weekends (especially in the Confederate Avenue and SouthDeKalb sites) to NOx-limited in the latter period (2003-2005), as expressed by lower 

ozone concentrations during the weekends. These results are consistent with the overall 

trend of reduction in NOx emissions in the region (Figure 2-3), and hence the decline in 

availability of NOx for ozone formation. 

b) 1997-1999

52.0

54.0

56.0

58.0

60.0

62.0

64.0

66.0

68.0

70.0

72.0

Conf.

Ave.

SouthDeKalbTucker Conyers Yorkville

Average of max 8-hr O3 

(ppb)

Weekdays Weekend

d) 2003-2005

44.0

46.0

48.0

50.0

52.0

54.0

56.0

Conf.

Ave.

SouthDeKalbTucker Conyers Yorkville

Average of max 8-hr O3 

(ppb)

Weekdays Weekend

a) 1997-2005

51.0

52.0

53.0

54.0

55.0

56.0

57.0

58.0

59.0

60.0

61.0

Conf.

Ave.

SouthDeKalbTucker Conyers Yorkville

Average of max 8-hr O3 

(ppb)

Weekdays Weekend

c) 2000-2002

48.0

50.0

52.0

54.0

56.0

58.0

60.0

Conf.

Ave.

SouthDeKalbTucker Conyers Yorkville

Average of max 8-hr O3 

(ppb)

Weekdays Weekend

Figure 2-6: Weekdays/weekend differences in ozone concentrations at the Confederate 

Avenue site and the four Atlanta PAMS sites for (a) 1997-2005, (b) 1997-1999, (c) 2000-

2002, and (d) 2003-2005. 

2.3 Conclusions 

Various analyses presented in this section suggest that despite a regional trend in ozone 

levels throughout the state of Georgia, there is a local pattern of ozone formation in the 

Atlanta area and that reductions in emissions of ozone precursors in the Atlanta 

nonattainment area are likely to introduce a change in (local) ozone concentrations. In 

addition, it has been shown that the Atlanta nonattainment area is generally NOx-limited, 

though may be VOC-limited or transitional in some cases. Analysis of data collected at 

the four PAMS sites throughout Atlanta indicates that lower VOC/NOx ratios are 

associated with elevated daily maximum 8-hour ozone concentrations. Analysis of ozone, 

NO and NOx data using the ozone M.A.P.P.E.R. program indicated that ozone formation 

in Atlanta is generally transitional to NOx-limited, but when the results were binned 

according to the daily maximum 8-hour ozone, ozone formation seemed strongly NOxlimited on days of elevated ozone. An analysis of weekend/weekday differences in ozone 

47 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

concentration also indicate a generally NOx-limited regime, with ozone formation 

becoming more NOx-limited in recent years compared to the late 1990's. 

These findings are generally in agreement with several studies of the trends and limiting 

factors for ozone formation in Atlanta. Pun et al. (2003) investigated the weekly patterns 

of ozone in Atlanta and found elevated midweek concentrations compared to weekends, 

with stronger weekly patterns in later years (1995-1999 compared to 1986-1990), 

concluding that the availability of NOx drives the weekly ozone cycle in Atlanta. 

Analyzing various aircraft measurements, Sillman et al. (1997) conclude that Atlanta 

ozone is mostly NOx-limited, using various indicator ratios. 

The findings presented here are also consistent with results from an air-quality model 

based sensitivity analysis (Appendix F). The integration of these various analyses 

support the control of NOx emissions as part of a state strategy for reducing ozone levels 

in the Atlanta area. 

48 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

49 

3.0 ATTAINMENT DEMONSTRATION METHODS AND 

INPUTS 

The attainment modeling for the Atlanta nonattainment area was performed in 

conjunction with the regional haze modeling being done by the Southeast Regional 

Planning Organization, Visibility Improvement State and Tribal Association of the 

Southeast (VISTAS) and the fine particulate matter (PM2.5) and ozone modeling being 

done by the Association of Southeastern Integrated Planning (ASIP). VISTAS and ASIP 

are run by the ten Southeast states (Alabama, Florida, Georgia, Kentucky, Mississippi, 

North Carolina, South Carolina, Tennessee, Virginia and West Virginia). Since the 

regional haze and PM2.5 modeling uses annual simulations and includes an intermediate 

year that is the attainment year required for the Atlanta nonattainment area, the EPD 

decided to use the this modeling for its attainment demonstration. The sections below 

outline the methods and inputs used by VISTAS/ASIP for the regional modeling. 

3.1 Analysis Method 

The modeling analysis is a complex technical evaluation that begins by selection of the 

modeling system. VISTAS decided to use the following modeling system: 

• Meteorological Model: The Pennsylvania State University/National Center for 

Atmospheric Research (PSU/NCAR) Mesoscale Meteorological Model (MM5) is 

a nonhydrostatic, prognostic meteorological model routinely used for urban- and 

regional-scale photochemical, fine particulate matter, and regional haze regulatory 

modeling studies. 

• Emissions Model: The Sparse Matrix Operator Kernel Emissions (SMOKE) 

modeling system is an emissions modeling system that generates hourly gridded 

speciated emission inputs of mobile, nonroad mobile, area, point, fire and 

biogenic emission sources for photochemical grid models. 

• Air Quality Model: USEPA's Models-3/ Community Multiscale Air Quality 

(CMAQ) modeling system is an 'One-Atmosphere' photochemical grid model 

capable of addressing ozone, particulate matter (PM), visibility and acid 

deposition at regional scale for periods up to one year. 

Additionally, a historical year is selected to model that represent typical meteorological 

conditions in the Southeast when high ozone, PM2.5 and poor visibility are observed 

throughout the Region. Once the historical year is selected, meteorological inputs are 

developed using the meteorological model. Emission inventories are also developed for 

the historical year and processed through the emissions model. These inputs are used in 

the air quality model to predict ozone, PM2.5 and visibility, with the results compared to 

the historic data. The model performance is evaluated by comparing the modeled 

predicted data to the historic air quality data. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

50 

Once model performance is deemed adequate, typical baseline and future year emissions 

are processed through the emissions model. For this demonstration, the baseline year 

was 2002, which corresponds with the same year as the historic meteorology used in the 

modeling. The attainment future year EPD is using for this demonstration is 2009, since 

the mandatory attainment date for Atlanta as a moderate nonattainment area is June 15, 

2010. The attainment date is set prior to the completion of the 2010 ozone season, 

therefore the attainment of the NAAQS would have to be met by the end of the 2009 

ozone season. These emissions are processed through the air quality model with the 

meteorological inputs. The air quality modeling results are used to determine a relative 

reduction in future ozone, which is used in the attainment demonstration. The complete 

modeling protocol and the quality assurance project plan used for this analysis can be 

found in Appendix N and Appendix P, respectively. 

3.2 Model Selection 

To ensure that a modeling study is defensible, care must be taken in the selection of the 

models to be used. The models selected must be scientifically appropriate for the 

intended application and be freely accessible to all stakeholders. Scientifically 

appropriate means that the models address important physical and chemical phenomena 

in sufficient detail, using peer-reviewed methods. Freely accessible means that model 

formulations and coding are freely available for review and that the models are available 

to stakeholders, and their consultants, for execution and verification at no or low cost. 

The following sections outline the criteria for selecting a modeling system that is both 

defensible and capable of meeting the study's goals. These criteria were used in selecting 

the modeling system used for this modeling attainment demonstration. 

3.2.1 Selection of Photochemical Grid Model 

Criteria 

For a photochemical grid model to qualify as a candidate for use in an attainment 

demonstration of the 8-hour ozone NAAQS, a State needs to show that it meets several 

general criteria: 

• The model has received a scientific peer review 

• The model can be demonstrated applicable to the problem on a theoretical basis 

• Data bases needed to perform the analysis are available and adequate 

• Available past appropriate performance evaluations have shown the model is not 

biased toward underestimates or overestimates 

• A protocol on methods and procedures to be followed has been established 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

51 

• The developer of the model must be willing to make the source code available to 

users for free or for a reasonable cost, and the model cannot otherwise be 

proprietary. 

Overview of CMAQ 

The photochemical model selected for this study was CMAQ version 4.5. For more than 

a decade, the U.S.EPA has been developing the Models-3 CMAQ modeling system with 

the overarching aim of producing a 'One-Atmosphere' air quality modeling system 

capable of addressing ozone, fine particulate matter, visibility and acid deposition within 

a common platform. The original justification for the Models-3 development emerged 

from the challenges posed by the 1990 CAAA and the USEPA's desire to develop an 

advanced modeling framework for 'holistic' environmental modeling utilizing state-ofscience representations of atmospheric processes in a high performance computing 

environment. The U.S.EPA completed the initial stage of development with Models-3 

and released the CMAQ model in mid 1999 as the initial operating science model under 

the Models-3 framework. The most recent rendition is CMAQ version 4.5, which was 

released in October 2004. 

Another reason for choosing CMAQ as the atmospheric model is the ability to do oneatmospheric modeling. Since EPD will be using the same modeling exercise for the 

ozone and PM2.5 attainment demonstrations SIPs, as well as the regional haze SIP, having 

a model that can handle both ozone and particulate matter is essential. A number of 

features in CMAQ's theoretical formulation and technical implementation make the 

model well suited for annual PM modeling. 

The configuration used for this modeling demonstration, as well as a more detailed 

description of the CMAQ model, can be found in the Modeling Protocol (Appendix N). 

3.2.2 Selection of Meteorological Model 

Criteria 

Meteorological models, either through objective, diagnostic, or prognostic analysis, 

extend available information about the state of the atmosphere to the grid upon which 

photochemical grid modeling is to be carried out. The criteria for selecting a 

meteorological model are based on both the model's ability to accurately replicate 

important meteorological phenomena in the region of study, and the model's ability to 

interface with the rest of the modeling systems -- particularly the photochemical grid 

model. With these issues in mind, the following criteria were established for the 

meteorological model to be used in this study: 

• Non-Hydrostatic Formulation 

• Reasonably current, peer reviewed formulation 

• Simulates Cloud Physics 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

52 

• Publicly available at no or low cost 

• Output available in I/O API format 

• Supports Four Dimensional Data Assimilation (FDDA) 

• Enhanced treatment of Planetary Boundary Layer heights for AQ modeling 

Overview of MM5 

The non-hydrostatic MM5 model is a three-dimensional, limited-area, primitive equation, 

prognostic model that has been used widely in regional air quality model applications. 

The basic model has been under continuous development, improvement, testing and open 

peer-review for more than 20 years and has been used worldwide by hundreds of 

scientists for a variety of mesoscale studies. 

MM5 uses a terrain-following non-dimensionalized pressure, or "sigma," vertical 

coordinate similar to that used in many operational and research models. In the nonhydrostatic MM5, the sigma levels are defined according to the initial hydrostaticallybalanced reference state so that the sigma levels are also time-invariant. The gridded 

meteorological fields produced by MM5 are directly compatible with the input 

requirements of "one atmosphere" air-quality models using this coordinate. MM5 fields 

can be easily used in other regional air quality models with different coordinate systems 

by performing a vertical interpolation, followed by a mass-conservation re-adjustment. 

Distinct planetary boundary layer (PBL) parameterizations are available for air-quality 

applications, both of which represent sub-grid-scale turbulent fluxes of heat, moisture and 

momentum. One scheme uses a first-order eddy diffusivity formulation for stable and 

neutral environments and a modified first-order scheme for unstable regimes. The other 

scheme uses a prognostic equation for the second-order turbulent kinetic energy, while 

diagnosing the other key boundary layer terms. 

Initial and lateral boundary conditions are specified for real-data cases from mesoscale 

three-dimensional analyses performed at 12-hour intervals on the outermost grid mesh 

selected by the user. Surface fields are analyzed at three-hour intervals. A Cressmanbased technique is used to analyze standard surface and radiosonde observations, using 

the National Meteorological Center's spectral analysis, as a first guess. The lateral 

boundary data are introduced using a relaxation technique applied in the outermost five 

rows and columns of the coarsest grid domain. 

Results of detailed performance evaluations of the MM5 modeling system in regulatory 

air quality application studies have been widely reported in the literature (e.g., Emery et 

al., 1999; Tesche et al., 2000, 2003) and many have involved comparisons with other 

prognostic models such as the Regional Atmospheric Modeling System (RAMS) and the 

Systems Application International Mesoscale Model. The MM5 enjoys a far richer 

application history in regulatory modeling studies compared with RAMS or other models. 

Furthermore, in evaluations of these models in over 60 recent regional scale air quality 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

53 

application studies since 1995, it has generally been found that the MM5 model tends to 

produce somewhat better photochemical model inputs than alternative models. 

The configuration used for this modeling demonstration, as well as a more detailed 

description of the MM5 model, can be found in the Modeling Protocol (Appendix N). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

54 

3.2.3 Selection of Emissions Processing System 

Criteria 

The principal criterion for an emissions processing system is that it accurately prepares 

emissions files in a format suitable for the photochemical grid model being used. The 

following list includes clarification of this criterion and additional desirable criteria for 

effective use of the system. 

• File System Compatibility with the I/O API 

• File Portability 

• Ability to grid emissions on a Lambert Conformal projection 

• Report Capability 

• Graphical Analysis Capability 

• MOBILE6 Mobile Source Emissions 

• Biogenic Emissions Inventory System version 2 (BEIS-3) 

• Ability to process emissions for the proposed domain in a reasonable amount of 

time. 

• Ability to process control strategies 

• No or low cost for acquisition and maintenance 

• Expandable to support other species and mechanisms 

Overview of SMOKE 

The SMOKE Emissions Processing System Prototype was originally developed at the 

Micro-computing Center of North Carolina. As with most "emissions models," SMOKE 

is principally an emission processing system and not a true emissions modeling system in 

which emissions estimates are simulated from "first principles." This means that, with 

the exception of mobile and biogenic sources, its purpose is to provide an efficient, 

modern tool for converting emissions inventory data into the formatted emission files 

required by an air quality simulation model. For mobile sources, SMOKE actually 

simulates emissions rates based on input mobile-source activity data, emission factors 

and outputs from transportation travel-demand models. SMOKE was originally designed 

to allow emissions data processing methods to utilize emergent high-performancecomputing as applied to sparse-matrix algorithms. Indeed, SMOKE is the fastest 

emissions processing tool currently available to the air quality modeling community. The 

sparse matrix approach utilized throughout SMOKE permits both rapid and flexible 

processing of emissions data. The processing is rapid because SMOKE utilizes a series 

of matrix calculations instead of less efficient algorithms used in previous systems. The 

processing is flexible because the processing steps of temporal projection, controls, 

chemical speciation, temporal allocation, and spatial allocation have been separated into 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

55 

independent operations wherever possible. The results from these steps are merged 

together at a final stage of processing. 

SMOKE contains a number of major features that make it an attractive component of the 

modeling system. The model supports a variety of input formats from other emissions 

processing systems and models. It supports both gridded and county total land use 

scheme for biogenic emissions modeling. SMOKE can accommodate emissions files 

from up to 10 countries and any pollutant can be processed by the system. 

For additional information about the SMOKE model please refer to Georgia EPD’s 

Modeling Protocol found in Appendix N. 

3.3 Episode Selection 

A crucial step to SIP modeling is the selection of episodes to model. Several 

considerations need to be weighed before settling on not only which days to model, but 

how many days for each episode. This section details the guidance and process by which 

episodes were selected for the 8-hour Ozone SIP modeling package. The time frame for 

the ozone season considered in this episode selection is May through September even 

though the ambient monitoring for ozone is required from March through October. 

3.3.1 Overview of U.S.EPA Guidance on Ozone 

The USEPA's September 2006 draft final guidance (referred to as Attainment Guidance), 

Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air 

Quality Goals for Ozone, PM2.5 and Regional Haze (see Appendix L), sets out specific 

criteria for the selection of episodes to model for attainment of the 8-hour ozone 

NAAQS. First, episodes should include days encompassing a variety of meteorological 

conditions, including varying wind directions, for days exceeding 0.084 ppm. 

Additionally, episodes should be selected that contain days close (within ± 0.010 ppm) to 

the current design value (DVC). Episodes should also be chosen around days for which 

there are extensive air quality and meteorology measurements, including measurements 

aloft, measurements of indicator species and/or precursor measurements. Finally, a 

sufficient number of days should be selected to ensure robust attainment tests at violating 

monitoring sites. 

In addition to these primary criteria, the U.S.EPA also suggests a set of secondary criteria 

that may be used in the selection of episodes. This set of criteria allows states to give 

preference to previously modeled episodes. This is a very valuable consideration, as the 

U.S.EPA points out, since it can save modeling resources and effort. Additional 

considerations include selecting episodes maximizing the number of days and sites 

observing a violation, selecting episodes which include weekends, and the selection of 

episodes meeting primary and secondary criteria in other nonattainment areas, when 

participating in regional modeling. Using these criteria laid out by the U.S.EPA, the data 

available was systematically examined to determine the best episodes for modeling. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

56 

3.3.2 Episode Selection 

With the advances in computing and storage technologies, and aided by regional 

modeling efforts, EPD will use modeling for the 2002 ozone season (May through 

September) for the 8-hour ozone attainment demonstration SIP. By modeling this season, 

several criteria are covered, including the modeling of weekends and a sufficient number 

of days to ensure a robust modeled attainment test. Modeling the 2002 ozone season will 

also accomplish the goal of encompassing a myriad of meteorological conditions that 

influence ozone concentrations. Details of the episode selection process can be found in 

Appendix N. 

3.4 Modeling Domains 

3.4.1 Horizontal Modeling Domain 

The CMAQ model was run in one-way nested grid mode. This allowed the larger outer 

domains to feed concentration data to the inner nested domain. One-way nesting is 

believed to be appropriate for the generally stagnant conditions experienced during 

Georgia ozone episodes. Two-way nesting was not considered due to numerical and 

computational uncertainty associated with the technique. 

The horizontal coarse grid modeling domain boundaries were determined through a 

national effort to develop a common grid projection and boundary. Since this national 

modeling domain was used in the VISTAS regional haze modeling, it was used for the 

attainment demonstration as well. A smaller 12-km grid, modeling domain was selected 

in an attempt to balance location of areas of interest, such as ozone and fine particulate 

matter nonattainment areas, as well as Class I and wilderness areas for regional haze. 

Processing time was also a factor in choosing a smaller 12-km grid, modeling domain. 

The coarse 36-km horizontal grid domain covers the continental United States. This 

domain was used as the outer grid domain for MM5 modeling with the CMAQ domain 

nested within the MM5 domain. Figure 3-1 shows the MM5 horizontal domain as the 

outer most, blue grid with the CMAQ 36-km domain nested in the MM5 domain. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 3-1: The MM5 horizontal domain is the outer most, blue grid, with the CMAQ 36-

km domain nested in the MM5 domain. 

To achieve finer spatial resolution in the VISTAS states, a one-way nested high 

resolution (12-km grid resolution) was used. Figure 3-2 shows the 12-km grid, modeling 

domain for the VISTAS region. This is the modeling domain on which the attainment 

test results are based. The North Carolina Division of Air Quality (NCDAQ) did a study 

(Arunachalam et al., 2006) to determine if using a finer grid resolution provided different 

modeling results. Since the USEPA's attainment test uses the modeling results to 

determine the relative reductions in ozone between the base year and the future year, the 

NCDAQ determined that effectively the same attainment test results are obtained from 

12-km grid modeling or 4-km grid modeling. Since 4-km grid modeling takes 

significantly more time and resources to run, the EPD decided to use the VISTAS 12-km 

grid modeling results for this attainment demonstration. 

57 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 3-2: A more detailed view of the 12-km grid over the VISTAS region. 

3.4.2 Vertical Modeling Domain 

The CMAQ vertical structure is primarily defined by the vertical grid used in the MM5 

modeling. The MM5 model employed a terrain following coordinate system defined by 

pressure, using 34 layers that extend from the surface to the 100 mb. Table 3-1 lists the 

layer definitions for both MM5 and for CMAQ. A layer-averaging scheme is adopted for 

CMAQ to reduce the computational cost of the CMAQ simulations. The effects of layer 

averaging were evaluated in conjunction with the VISTAS modeling effort and was 

found to have a relatively minor effect on the model performance metrics when both the 

34 layer and a 19 layer CMAQ models were compared to ambient monitoring data. 

58 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

59 

Table 3-1: Vertical Layer Definition For MM5 and CMAQ 

MM5 Simulation CMAQ 19 Layers

Layer Sigma Pressure 

(mb) 

Height 

(m) 

Depth 

(m) 

Layer Sigma Pressure 

(mb) 

Height 

(m) 

Depth 

(m) 

34 0.000 100 14662 1841 19 0.000 100 14662 6536

33 0.050 145 12822 1466 0.050 145 

32 0.100 190 11356 1228 0.100 190 

31 0.150 235 10127 1062 0.150 235 

30 0.200 280 9066 939 0.200 280 

29 0.250 325 8127 843 18 0.250 325 8127 2966

28 0.300 370 7284 767 0.300 370 

27 0.350 415 6517 704 0.350 415 

26 0.400 460 5812 652 0.400 460 

25 0.450 505 5160 607 17 0.450 505 5160 1712

24 0.500 550 4553 569 0.500 550 

23 0.550 595 3984 536 0.550 595 

22 0.600 640 3448 506 16 0.600 640 3448 986

21 0.650 685 2942 480 0.650 685 

20 0.700 730 2462 367 15 0.700 730 2462 633

19 0.740 766 2095 266 0.740 766 

18 0.770 793 1828 259 14 0.770 793 1828 428

17 0.800 820 1569 169 0.800 820 

16 0.820 838 1400 166 13 0.820 838 1400 329

15 0.840 856 1235 163 0.840 856 

14 0.860 874 1071 160 12 0.860 874 1071 160

13 0.880 892 911 158 11 0.880 892 911 158

12 0.900 910 753 78 10 0.900 910 753 155

11 0.910 919 675 77 0.910 919 

10 0.920 928 598 77 9 0.920 928 598 153

9 0.930 937 521 76 0.930 937 

8 0.940 946 445 76 8 0.940 946 445 76

7 0.950 955 369 75 7 0.950 955 369 75

6 0.960 964 294 74 6 0.960 964 294 74

5 0.970 973 220 74 5 0.970 973 220 74

4 0.980 982 146 37 4 0.980 982 146 37

3 0.985 986.5 109 37 3 0.985 986.5 109 37

2 0.990 991 73 36 2 0.990 991 73 36

1 0.995 995.5 36 36 1 0.995 995.5 36 36

0 1.000 1000 0 0 0 1.000 1000 0 0 

3.5 Emission Inventory 

3.5.1 Types of Emission Inventories 

In addition to the various source classifications, there are also various types of emission 

inventories. The first is the "actual" base year inventory. This inventory is the base year 

emissions that correspond to the meteorological data, for this modeling effort is 2002. 

These emissions are used for evaluating the air quality model performance. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

60 

The second type of inventory is the "typical" base year inventory. This inventory is 

similar to the actual base year, however for sources that may have significant changes 

from year-to-year, a more typical emission value is used. In this modeling effort, typical 

emissions were developed for the electric generating units (EGUs) and the wildland fire 

emissions. The air quality modeling results using these emissions are used in calculating 

the relative response factors used in the attainment demonstration test. 

The “future” year base inventory is an inventory developed for some future year for 

which attainment of the ozone standard is needed. For this modeling project, the future 

year inventory will be 2009, the last complete year for which the standard must be 

attained. It is the future base year inventory that control strategies and sensitivities are 

applied to determine what controls beyond those measures already included in the future 

year base inventory, to which source classifications must be made in order to attain and 

maintain the ozone standard. 

Lastly, ozone season averages were computed based on emissions from May through 

September which makes up a portion of the ozone season of March through October. 

3.5.2 Emission Inventory Source Classification 

There are five different emission inventory source classifications, stationary point and 

area sources, off-road and on-road mobile sources, and biogenic sources. Stationary 

point sources are those sources that emit greater than a specified tonnage per year and the 

data is provided at the facility level. EPA has established certain minimum point source 

thresholds for both pollutant nonattainment areas and attainment areas. According to the 

Consolidated Emissions Reporting Rule (CERR), States are required to report data for 

larger point sources, or Type A point sources, on an annual basis. Type B sources refer 

to all point sources, including Type A sources. The reporting frequency for Type B 

sources has been established as once every 3 years. Area (or nonpoint sources) are 

sources that do not qualify as point sources under the relevant emissions cutoffs. Area 

sources encompass more widespread sources that may be abundant, but that, individually, 

release small amounts of a given pollutant and collectively could be significant. 

Examples of area sources include dry cleaners, residential wood heating, autobody 

painting, fires, and consumer solvent use. These types of emissions are estimated on the 

county level. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

61 

Georgia EPD used the 2002 CERR, in part, to build its 2002 base year inventory for this 

analysis. Stationary sources located in the 13-county metro Atlanta area [1-hour ozone 

nonattainment area] in 2002 were located in a “serious” nonattainment area and the 

annual reporting threshold for such sources was 50 tons per year for VOC and NOx. In 

the additional seven additional counties that make up the 20-county metro Atlanta ozone 

nonattainment area in 2002 were located in an attainment area and the annual reporting 

threshold for such sources was 100 tons per year for VOC and NOx. Off-road mobile 

sources include equipment that can move, but do not use the roadways, i.e., lawn 

mowers, construction equipment, railroad locomotives, aircraft, etc. The emissions from 

these sources, like stationary area sources, are estimated on the county level. On-road 

mobile sources are automobiles, trucks, and motorcycles that use the roadway system. 

The emissions from these sources are estimated by vehicle type and road type and are 

summed to the county level. Biogenic sources are the natural sources like trees, crops, 

grasses and natural decay of plants. The emissions from these sources are estimated on a 

county level. 

In the sections that follow, a synopsis of the inventories used for each source 

classifications are discussed. The detailed discussions of the emissions inventory 

development can be found in Appendix K. Emission summaries by county for the 

Atlanta nonattainment area can be found in Tables 3-2 and 3-3, and the state-wide 

emission summaries are in Appendix A. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 3-2: Summary of ozone season daily NOX emissions in 2002 and 2009 by source categories for 20 coun

Point Area On-Road N

Counties FIPs 2002 2009 Diff % 2002 2009 Diff % 2002 2009 Diff % 2002 20Barrow Co 013013 0.06 0.07 0.01 9.42 0.45 0.46 0.01 2.52 5.69 4.69 -1.00 -17.51 1.41 1.Bartow Co 013015 69.92 17.60 -52.32 -74.83 1.30 1.35 0.05 4.03 15.76 11.46 -4.29 -27.26 3.89 3.Carroll Co 013045 0.06 0.07 0.01 10.49 1.30 1.35 0.05 3.88 10.91 7.92 -2.99 -27.44 2.39 1.Cherokee Co 013057 0.20 0.22 0.02 8.73 0.72 0.76 0.04 5.09 10.25 6.77 -3.49 -34.00 3.59 3.Clayton Co 013063 0.30 0.35 0.05 17.36 1.08 1.12 0.04 3.53 19.96 11.64 -8.31 -41.66 19.21 20Cobb Co 013067 12.62 11.54 -1.08 -8.57 4.12 4.26 0.14 3.42 50.66 29.03 -21.62 -42.68 12.67 10Coweta Co 013077 23.08 31.06 7.98 34.57 0.89 0.92 0.03 3.82 7.86 5.11 -2.74 -34.90 3.30 2.DeKalb Co 013089 0.49 0.53 0.04 7.92 4.06 4.19 0.14 3.37 63.33 36.25 -27.09 -42.77 9.98 8.Douglas Co 013097 0.06 0.06 0.01 8.87 0.48 0.50 0.02 4.06 9.70 6.35 -3.35 -34.52 1.87 1.Fayette Co 013113 - - - - 0.77 0.80 0.03 4.33 5.20 3.18 -2.02 -38.80 2.18 1.Forsyth Co 013117 0.12 0.12 0.00 0.82 0.84 0.88 0.04 4.63 8.41 6.16 -2.25 -26.72 3.11 2.Fulton Co 013121 5.46 4.19 -1.27 -23.28 6.59 6.79 0.20 3.09 91.42 52.06 -39.37 -43.06 20.02 17Gwinnett Co 013135 0.09 0.09 0.00 1.30 4.55 4.70 0.16 3.48 49.26 30.32 -18.94 -38.45 15.36 12Hall Co 013139 0.29 0.29 0.00 0.29 2.79 2.89 0.10 3.61 15.12 10.89 -4.23 -27.98 3.80 3.Henry Co 013151 6.44 2.78 -3.67 -56.89 0.60 0.63 0.03 5.31 13.40 8.48 -4.92 -36.70 4.68 4.Newton Co 013217 0.00 0.00 0.00 5.43 0.79 0.80 0.01 1.42 6.72 4.99 -1.73 -25.76 1.95 1.Paulding Co 013223 - - - - 0.26 0.31 0.05 17.63 4.76 3.33 -1.43 -30.01 2.66 2.Rockdale Co 013247 0.08 0.09 0.01 6.94 1.00 1.04 0.04 4.49 5.70 3.49 -2.21 -38.81 1.59 1.Spalding Co 013255 0.00 0.01 0.00 9.14 0.79 0.82 0.03 3.85 5.25 3.96 -1.29 -24.55 0.87 0.Walton Co 013297 0.01 0.40 0.39 3589.33 0.47 0.46 -0.01 -1.19 5.72 4.35 -1.37 -23.95 1.70 1.Total 119.31 69.47 -49.84 -41.77 33.85 35.07 1.21 3.59 405.06 250.43 -154.63 -38.17 116.23 103

62 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 3-3: Summary of ozone season daily VOC emissions in 2002 and 2009 by source categories for 20 coun

Point Area On-Road N

Counties FIPs 2002 2009 Diff % 2002 2009 Diff % 2002 2009 Diff % 2002 200Barrow Co 013013 0.02 0.01 -0.02 -71.59 3.74 3.57 -0.17 -4.54 4.30 3.65 -0.65 -15.04 0.75 0.5Bartow Co 013015 1.31 1.41 0.10 7.87 8.05 7.39 -0.66 -8.22 10.56 8.00 -2.56 -24.27 2.54 2.1Carroll Co 013045 0.85 0.91 0.06 7.49 9.54 9.20 -0.34 -3.60 8.10 5.89 -2.21 -27.27 1.87 1.6Cherokee Co 013057 0.13 0.14 0.01 6.81 6.30 5.71 -0.58 -9.27 5.17 3.92 -1.25 -24.19 5.30 4.1Clayton Co 013063 1.29 1.14 -0.15 -11.92 9.53 8.49 -1.04 -10.92 9.90 6.53 -3.37 -34.03 3.83 3.1Cobb Co 013067 0.89 0.91 0.03 2.88 28.18 25.91 -2.27 -8.06 26.84 17.46 -9.38 -34.94 18.82 13.3Coweta Co 013077 0.62 0.52 -0.10 -16.39 3.94 3.53 -0.41 -10.34 3.75 2.70 -1.04 -27.84 2.49 1.6DeKalb Co 013089 4.66 3.88 -0.78 -16.74 44.67 39.56 -22.34 -15.63 31.21 20.56 -10.65 -34.13 16.76 11.7Douglas Co 013097 0.08 0.09 0.01 11.71 3.93 3.52 -0.41 -10.36 4.54 3.46 -1.08 -23.75 1.26 0.8Fayette Co 013113 - - - - 4.69 4.31 -0.37 -7.92 2.84 1.93 -0.92 -32.21 1.91 1.2Forsyth Co 013117 0.48 0.51 0.03 6.20 4.82 4.43 -0.39 -8.14 4.28 3.61 -0.67 -15.63 5.36 3.5Fulton Co 013121 5.42 4.32 -1.10 -20.36 49.47 46.45 -3.02 -6.10 46.10 30.33 -15.77 -34.21 17.19 13.8Gwinnett Co 013135 0.13 0.17 0.04 28.29 32.02 29.74 -2.28 -7.12 25.20 17.72 -7.48 -29.69 23.85 15.1Hall Co 013139 0.69 0.45 -0.24 -34.89 13.69 13.20 -0.49 -3.61 11.59 8.48 -3.11 -26.82 6.47 5.4Henry Co 013151 1.34 1.44 0.11 8.15 5.26 4.81 -0.45 -8.59 6.40 4.73 -1.67 -26.07 2.75 2.1Newton Co 013217 2.01 2.57 0.55 27.40 5.21 5.03 -0.17 -3.34 4.95 3.71 -1.25 -25.20 1.29 0.8Paulding Co 013223 - - - - 3.51 3.17 -0.34 -9.75 2.57 2.04 -0.53 -20.57 1.43 0.9Rockdale Co 013247 0.44 0.53 0.09 20.05 4.28 4.06 -0.22 -5.13 2.88 1.99 -0.89 -30.88 1.42 0.9Spalding Co 013255 0.18 0.17 -0.01 -7.06 5.95 5.90 -0.05 -0.85 4.14 3.10 -1.04 -25.08 1.21 1.1Walton Co 013297 0.32 0.25 -0.07 -20.82 4.92 4.72 -0.20 -4.14 4.66 3.52 -1.14 -24.50 1.53 0.9Total 20.86 19.41 -1.45 -6.95 251.69 232.7 -18.99 -7.54 219.98 153.33 -66.65 -30.30 118.03 85.4

63 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

64 

3.5.3 Stationary Point Sources 

Point source emissions are emissions from individual sources having a fixed location. 

Generally, these sources must have permits to operate and their emissions are inventoried 

on a regular schedule. Point source emissions data can be grouped into the EGU sources 

and the other point sources, i.e., non-EGUs. Stationary point NOx emissions comprise 

approximately 17.7% of total NOx emissions in the metro Atlanta nonattainment area for 

2002. Stationary point VOC emissions comprise approximately 3.4% of total VOC 

emission in the metro Atlanta nonattainment area for 2002. 

Electric Generating Units 

The actual base year inventory for the EGU sources used 2002 continuous emissions 

monitoring (CEM) data reported to the USEPA's Acid Rain program or 2002 hourly 

emissions data provided by stakeholders. This data provides hourly emissions profiles 

that can be used in the modeling of these large sources of NOx and helps to provide more 

accurate modeling of these sources (Appendix O). 

Since the NOx emissions from EGU sources are a significant part of the emissions 

inventory, a typical base year emissions inventory was developed for these sources to 

avoid anomalies in emissions due to variability in meteorology, economic and outage 

factors in 2002. This approach is consistent with the USEPA's modeling guidance. To 

develop a typical year 2002 emissions inventory for EGU sources, for each unit the 

average CEM heat input for 2000 through 2004 was divided by the 2002 actual heat input 

to generate a unit specific normalizing factor. This normalizing factor was then 

multiplied by the 2002 actual emissions. The heat inputs for the period 2000 through 

2004 were used since the modeling current design values use monitoring data from this 

same 5-year period. If a unit was shutdown for an entire year during the 2000 through 

2004 period, the average of the years the unit was operational was used. If a unit was 

shutdown in 2002, but not permanently shutdown, the emissions and heat inputs for 2001 

(or 2000) were used in the normalizing calculations. 

As part of the VISTAS modeling, VISTAS and the Midwest Regional Planning 

Organization contracted with ICF Resources, L.L.C., to generate future year emission 

inventory for the electric generating sector of the contiguous United States using the 

Integrated Planning Model (IPM). IPM is a dynamic linear optimization model that can 

be used to examine air pollution control policies for various pollutants throughout the 

contiguous United States for the entire electric power system. The dynamic nature of 

IPM enables the projection of the behavior of the power system over a specified future 

period. The optimization logic determines the least-cost means of meeting electric 

generation and capacity requirements while complying with specified constraints 

including air pollution regulations, transmission bottlenecks, and plant-specific 

operational constraints. The versatility of IPM allows users to specify which constraints 

to exercise and populate IPM with their own datasets. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

65 

The IPM modeling runs took into consideration the USEPA's Clean Air Interstate Rule 

(CAIR) implementation and Clean Air Mercury Rule (CAMR) and North Carolina's 

Clean Smokestacks Act compliance plans for Duke Power and Progress Energy. 

Table 3-4 lists EGU point sources in and near the Atlanta nonattainment area and the 

average daily ozone season NOx emissions. 

Table 3-4: Summary of ozone season daily NOX emissions (tons/day) in 2002 and 

2009 for major EGU point sources in and around the Atlanta nonattainment 

counties 

County FIPS Plant ID Plant Name 2002 2009 

Electrical Generating Units (EGU) 

Bartow 013015 01500011 GEORGIA POWER COMPANY, PLANT BOWEN 69.24 16.92 

Cobb 013067 06700003 GEORGIA POWER COMPANY, PLANT 

MCDONOUGH 11.28 10.21 

Coweta 013077 07700001 GEORGIA POWER COMPANY, PLANT YATES 22.93 30.89 

Monroe 013207 20700008 GEORGIA POWER COMPANY, PLANT SCHERER 77.41 52.55 

Putnam 013237 23700008 GEORGIA POWER COMPANY, PLANT BRANCH 62.59 58.31 

Heard 013149 14900001 GEORGIA POWER COMPANY, PLANT WANSLEY 44.59 10.24 

Floyd 013115 11500003 GEORGIA POWER COMPANY, PLANT HAMMOND 22.77 17.81 

NOx Emissions - Other Point Sources 

For the non-EGU sources, the same inventory will be used for both the actual and typical 

base year emissions inventories. The non-EGU category will use annual emissions as 

reported for the Consolidated Emissions Reporting Rule (CERR) for the year 2002. 

These emissions were temporally allocated to month, day, and hour using source category 

code (SCC) based allocation factors using the SMOKE emissions model. 

The general approach for assembling future year data was to use recently updated growth 

and control data consistent with USEPA's CAIR analyses. This data was supplemented 

with state specific growth factors and stakeholder input on growth assumptions. 

Table 3-5 lists non-EGU point sources in the Atlanta nonattainment counties with NOx 

emissions larger than 100 tons/year. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

66 

Table 3-5: Major non-EGU point sources in the Atlanta nonattainment counties with 

NOx emissions larger than 100 tons/year 

County FIPS Plant ID Plant Name 2002 2009 

Henry 013151 15100025 TRANSCONTINENTAL GAS PIPE LINE - STATION 6.43 2.76 

Fulton 013121 12100020 OWENS-BROCKWAY GLASS CONTAINER INC. 1.93 2.11 

Fulton 013121 12100021 OWENS CORNING - FAIRBURN PLANT 1.65 1.81 

Fulton 013121 12100401 LAFARGE BUILDING MATERIALS 1.63 0.00 

Cobb 013067 06700022 CARAUSTAR MILL GROUP, INC. 1.00 0.80 

Bartow 013015 01500061 ANHEUSER-BUSCH INC - CARTERSVILLE 0.41 0.41 

Hall 013139 13900002 CARGILL INC 0.29 0.29 

Clayton 013063 06300105 DELTA AIR LINES, INC. TOC 0.28 0.33 

3.5.4 Stationary Area Sources 

Stationary area sources include sources whose emissions are relatively small but due to 

the large number of these sources, the collective emissions could be significant (i.e., 

combustion of fuels for heating, structure fires, service stations, etc.). Emissions are 

estimated by multiplying an emission factor by some known indicator of collective 

activity, such as fuel usage, number of households, or population. Stationary area source 

emissions are estimated on the county level. A portion of the area source 2002 base year 

inventory for Georgia was developed by the EPD and provided to the VISTAS/ASIP 

contractor. The VISTAS/ASIP contractor calculated the remaining portion of the area 

source inventory. The sources estimated by the contractor include emissions from animal 

husbandry, wildland fires, and particulate matter from paved and unpaved roads. For the 

other states within the modeling domain, the state supplied data or the CERR data for 

2002 was used. 

The actual base year inventory will serve as the typical base year inventory for all area 

source categories except for wildland fires. For this source category, development of a 

typical year fire inventory provided the capability of using a comparable data set for both 

the base year and future years. Thus, fire emissions would remain the same for air 

quality modeling in both the base and any future years. The VISTAS Fire Special 

Interest Work Group was consulted and decided to use State level ratios of acres over a 

longer term record (three or more years) developed for each fire type relative to 2002. 

The 2002 acreage was then scaled up or down based on these ratios to develop a typical 

year inventory. 

For categories other than wildland fires, the VISTAS/ASIP contractor generated the 

future base year emissions inventory used in the attainment demonstration modeling. 

Growth factors supplied from the states or the USEPA's CAIR emission projections were 

applied to project the controlled emissions to the appropriate year. In some cases, the 

USEPA's Economic Growth and Analysis System Version 5 growth factors were used if 

no growth factor was available from either the states or the CAIR growth factor files. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

67 

Area source NOx emissions comprise approximately 5.0% of total NOx emissions in the 

metro Atlanta nonattainment area in 2002. Area source VOC emissions comprise 

approximately 41.2% of total VOC emissions in the metro Atlanta nonattainment area in 

2002. 

Appendix K provides a detailed discussion of the area source inventory. Appendix A 

provides emission summaries by county for average ozone season day area source 

emissions. 

3.5.5 Off-Road Mobile Sources 

Non-road mobile sources include equipment that can move, but do not use the roadways, 

such as construction equipment, aircraft, railroad locomotives, lawn and garden 

equipment, etc. For the majority of the non-road mobile sources, the emissions were 

estimated using the USEPA's NONROAD2005c model. For the three source categories 

not included in the NONROAD model, i.e., aircraft engines, railroad locomotives and 

commercial marine, more traditional methods of estimating the emissions were used. 

The same inventory will be used for both the actual and typical base year emissions 

inventories for the non-road mobile sources. For the source categories estimated using 

the USEPA's NONROAD model, the model was used to create a future base year 

inventory. The NONROAD model takes into consideration rules that are in effect that 

could impact the emissions from these source categories. The FAA's Terminal Area 

Forecast was used to project growth in aircraft emissions. For the commercial marine, 

railroad locomotives and the remaining airport emissions, the VISTAS/ASIP contractor 

calculated the future base year emissions using detailed inventory data (both before and 

after controls) for 1996 and 2010 obtained from the USEPA's Clean Air Interstate Rule 

Technical Support Document. When available, state specific growth factors were used. 

Off-road NOx emissions comprise approximately 17.2% of total NOx emissions in the 

metro Atlanta nonattainment area in 2002. Off-road VOC emissions comprise 

approximately 19.4% of total VOC emissions in the metro Atlanta nonattainment area in 

2002. 

Appendix K provides a detailed discussion of the non-road mobile source inventory. 

Appendix A provides emission summaries by county for average ozone season day nonroad emissions. 

3.5.6 Highway Mobile Sources 

In order to accurately model the mobile source emissions in the Atlanta nonattainment 

area, the newest version of the MOBILE model, MOBILE6.2, was used. Key inputs for 

the MOBILE model include information on the age of vehicles on the roads, the average 

speed on the roads, the mix of vehicles on the roads, any control technologies in place in 

an area to reduce emissions for motor vehicles (e.g., emissions inspection programs), and 

temperature. 

The MOBILE model takes into consideration rules that are in effect that impact the 

emissions from this source sector. For highway mobile sources, the actual and typical 

year emissions were the same and the MOBILE model was run using input data reflective 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

68 

of 2002. The same model then is run for the future year emissions inventory using input 

data reflective of 2009. Area-specific vehicle age distributions were modeled. For the 

Atlanta nonattainment area, 2002 and 2009 vehicle miles traveled (VMT) and speeds data 

from the Atlanta Regional Commission's travel demand model were used. Elsewhere in 

the state, emissions were modeled using 2002 VMT obtained from the Georgia 

Department of Transportation (GDOT) with emission factors based on MOBILE6 default 

speeds. For 2009 emissions modeling, 2009 VMT were projected by the VISTAS 

contractors based on linear growth as derived from the VMT data assembled by the U.S. 

EPA for their most recent heavy-duty diesel rulemaking. MOBILE6 default speeds were 

used for 2009 emissions modeling outside the Atlanta nonattainment area. 

For a detailed discussion about the mobile source inventory development used in the 

attainment demonstration modeling, please refer to Appendix K. Emission summaries by 

county for the mobile source sector can be found in Appendix A. Table 3-6 summarizes 

onroad mobile source emissions in the Atlanta area. On-road NOx emissions comprise 

approximately 60% of total NOx emissions in the metro Atlanta nonattainment area in 

2002. On-road VOC emissions comprise approximately 36% of total VOC emissions in 

the metro Atlanta nonattainment area in 2002. 

Table 3-6: Summary of ozone season daily NOX and VOC emissions (tons/day) in 

2002 and 2009 by onroad mobile sources in Atlanta 20 counties 

NOX VOC 

Category 2002 2009 2002 2009 

Heavy duty diesel vehicles 213.79 121.25 8.58 6.39 

Light duty diesel trucks 0.61 0.25 0.35 0.14 

Light duty diesel vehicles 0.20 0.04 0.09 0.02 

Heavy-Duty Gas Vehicles 29.98 16.02 7.73 4.93 

Light-Duty Gas Trucks 1 & 2 55.21 52.35 78.58 70.65 

Light-Duty Gas Trucks 3 & 4 24.36 22.57 21.73 18.04 

Light-Duty Gas Vehicles 80.01 37.01 100.81 51.00 

Light-Duty Gas Motorcycles 0.90 0.94 2.11 2.17 

Total 405.06 250.43 219.98 153.33 

3.5.7 Biogenic Emission Sources 

Biogenic sources are natural (i.e., non-anthropogenic) emissions sources. Biogenic 

sources are biological sources of ozone precursor emissions such as trees, agricultural 

crops, or microbial activity in soils or water. Biogenic emissions were prepared with the 

SMOKE-BEIS3 (Biogenic Emission Inventory System 3 version 0.9) preprocessor. 

SMOKE-BEIS3 is basically the Urban Airshed Model (UAM)-BEIS3 model, but also 

includes modifications to use MM5 data, gridded land use data, and science updates. The 

emission factors that are used in SMOKE-BEIS3 are the same as the emission factors in 

UAM-BEIS3. 

The basis for the gridded land use data used by BEIS3 is the county land use data in the 

Biogenic Emissions Landcover Database version 3 (BELD3) provided by the U.S.EPA. 

A separate land classification scheme, based upon satellite (AVHRR, 1 km spatial 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

69 

resolution) and census information, aided in defining the forest, agriculture and urban 

portions of each county. This emission inventory source sector introduces VOC 

emissions in a magnitude that exceeds all of the other categories combined. 

3.5.8 Emission Inventory Summary for Atlanta Nonattainment Area 

Daily NOx and VOC emissions during ozone seasons (May-September) are averaged to 

calculate ozone season daily emissions. In the 20 Atlanta nonattainment counties during 

2002, NOx emissions from on-road mobile sources are the largest contributing 57% of 

total NOx emissions, followed by non-road mobile source (19%), point source (19%) and 

area source (5%) (Figure 3-3). From 2002 to 2009, NOx emissions from point and onroad mobile sources are reduced by 42% and 33% respectively, leading to a 29% 

reduction in total NOx emissions. Emissions by source categories in each Atlanta County 

during both 2002 and 2009 are listed in Figure 3-3. NOx emissions from mobile source 

are highest in Fulton, DeKalb, Cobb, and Gwinnett counties, and such emissions from 

point source are highest in Bartow, Coweta, and Cobb counties (each of which contain 

Electric Generating Units). NOx emissions from major point sources in the 20 Atlanta 

nonattainment counties, including both EGU and non-EGU are listed in Table 3-4 for 

both 2002 and 2009. The NOx emission from Georgia Power, Bowen Plant is reduced the 

most by 76% among all facilities. Heavy-duty diesel vehicles and light-duty gas vehicles 

contribute 76% of NOx emissions from on-road mobile source category, and their 

emissions have been reduced by 34% and 50%, respectively, from 2002 to 2009. 

VOC emissions from biogenic sources are the largest (contributing 62% of the total VOC 

emissions) in the 20 Atlanta nonattainment counties, followed by area source, on-road 

and non-road mobile source and point source. VOC emissions are high in DeKalb, 

Fulton, Gwinnett, and Cobb counties. Total anthropogenic VOC emissions are reduced 

by 20% in the 20 counties from 2002 to 2009, mainly contributed by emission reduction 

in on-road and non-road mobile source (29% of reduction) and area sources (10% of 

reduction). Light-duty gas vehicles have the largest emissions and such emissions have 

been controlled the most from 2002 to 2009. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

NOx Ozone Season Daily Emissions

0

50

100

150

200

250

300

350

400

450

point area onroad nonroad

Sources

Emissions (tpd)

2002 2009

VOC Ozone Season Daily Emissions

0

200

400

600

800

1000

1200

1400

biog point area onroad nonroad

Sources

Emissions (tpd)

2002 2009

Figure 3-3: Ozone season daily NOX and VOC emissions by source categories for 20 

counties in Atlanta. 

70 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

NOx Ozone Season Daily Emissions 140

0

20406080

100120

Barrow Bartow Carroll Cherokee Clayton Cobb Coweta DeKalb Douglas Fayette Forsyth Fulton Gwinnett Hall Henry Newton Paulding 

Emissions (tpd)

VOC Ozone Season Daily Emissions

0

4080

120160200

Barrow Bartow Carroll Cherokee Clayton Cobb Coweta DeKalb Douglas Fayette Forsyth Fulton Gwinnett Hall Henry Newton Paulding 

Emissions (tpd)

Figure 3-4: Ozone season daily NO

X and VOC Emissions by source categories and metro Atlanta 8-hour ozon

counties. 

71 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

72 

4.0 MODEL PERFORMANCE EVALUATION 

The performance evaluation of the MM5 meteorological model and CMAQ air quality 

model is critical for determining if the modeling system can be used to accurately predict 

future ozone concentrations. The following section describes these evaluations. 

4.1 MM5 Model Performance Evaluation 

U.S. EPA guidance (EPA, 2007) recognizes the complexity and importance of evaluating 

meteorological modeling results for air quality applications. Since MM5 algorithms and 

modules have undergone significant peer review and testing, an “operational” evaluation 

of the modeling system is sufficient to serve as the basis of evaluating if the system is 

operating with sufficient reliability to be used in support of SIP development. An 

operational evaluation can be defined as the process of evaluating how accurately a 

modeling simulation estimates observed quantities. In the case of a prognostic 

meteorological model, this amounts to a statistical analysis of model predictions and 

surface observations. 

The 2002 annual MM5 simulation used in this attainment demonstration was performed 

by VISTAS. The VISTAS MM5 modeling protocol and the VISTAS model performance 

evaluation are contained in Appendix I and Appendix J, respectively. Additional model 

performance evaluations were performed by GA EPD to look at the model performance 

at Georgia sites. GA EPD used the software package METSTAT developed by 

ENVIRON corporation for calculating model performance statistics. METSTAT 

computes domain wide surface statistics for temperature, wind speed and direction, and 

humidity. The metrics include: Bias Error (B), Gross Error (E) and Root Mean Square 

Error (RMSE), Systematic Root Mean Square Error (RMSEs), Unsystematic Root Mean 

Square Error (RMSEu) and Index Of Agreement (IOA). Mathematical formulation of 

these variables is provided in Table 4-1. The surface meteorological data for this analysis 

was obtained from http://dss.ucar.edu/datasets/ds472.0. 

While reviewing statistics, the reader is cautioned that summary statistics are useful in 

making only a general assessment about the adequacy of meteorological fields. For 

example, daily-mean performance statistics are likely to conceal important hour-to-hour 

variations. Also, summary statistics depend upon the number of observation-prediction 

pairs and generally improve with larger sampling sizes and longer averaging periods. 

This is because the probability of statistics being affected by extreme values is high in 

smaller sample sizes. These and other concerns have lead U.S. EPA to recommend that 

benchmarks proposed in Table 4-2 (Emery et al., 2001) should not be used in a 

“pass/fail” model, but only as a means of assessing general confidence in meteorological 

model output. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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A graphical summary of the daily and hourly mean performance statistics for the 12-km 

grid resolution modeling simulation is provided in Appendix R. Monthly averaged 

statistics have also been provided in Figure 4-1 and Table 4-3. Statistics have been 

computed at monitoring stations that are located in and around Georgia. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 4-1: Mathematical Formulation of Statistical Metrics Used for Evaluating 

Mesoscale Meteorological Model Performance 

Metrics Formulation 

Bias ∑∑( ) = =

= −

J

j

I

i

i

j

i

j OP

IJ

B

1 1

1

Gross Error ∑∑= =

= −

J

j

I

i

i

j

i

j OP

IJ

E

1 1

1

Root Mean Square Error ( )

2/1

1 1

1 2

⎥

⎦

⎤ ⎢

⎣

⎡ = ∑∑ − = =

J

j

I

i

i

j

i

j OP

IJ

RMSE

Systematic Root Mean Square Error ( )

2/1

1 1

2 ˆ 1 ⎥

⎦

⎤ ⎢

⎣

⎡ = ∑∑ − = =

J

j

I

i

i

j

i

S j OP

IJ

RMSE

Unsystematic Root Mean Square Error ( )

2/1

1 1

2 ˆ 1 ⎥

⎦

⎤ ⎢

⎣

⎡ = ∑∑ − = =

J

j

I

i

i

j

i

u j PP

IJ

RMSE

Index of Agreement 

⎥

⎥

⎥

⎥

⎦

⎤

⎢

⎢

⎢

⎢

⎣

⎡

−+−

−=

∑∑= =

J

j

I

i

o

i

jo

i

j MOMP

RMSEIJ IOA

1 1

2 . 1 

Table 4-2: Statistical Benchmarks for Mesoscale Meteorological Models 

Statistical Measure Benchmark 

Wind Speed Bias (m/s) <±0.5 

Wind Speed Total RMSE (m/s) 2.0 

Wind Speed Index of Agreement 0.6 

Wind Direction Gross Error (degree) 30.0 

Wind Direction Bias (degree) <±10.0 

Temperature Bias (Kelvin) <±0.5 

Temperature Gross Error (degree) 2.0 

Temperature Index of Agreement 0.8 

Humidity Bias (g/kg) <±1.0 

Humidity Gross Error (g/kg) 2.0 

Humidity Index of Agreement 0.6 

Overall, the simulation is able to capture meteorological conditions observed during the 

study period with the adequate level of accuracy. Performance statistics for most days are 

within the benchmarks proposed by Emery (2001). Monthly average statistics reveal 

under prediction in humidity from May through November, and an over prediction in 

temperature during the summer months (May through September). The simulation tends 

to over predict day-time and night-time temperature, and consistently over-predicts nighttime wind speed. However, the magnitude of these under/over predictions remains small. 

Deficiencies in physical parameterization (planetary boundary layer, surface heat, and 

74 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

75 

moisture budgets) at smaller scales, together with the issue of data scarcity and 

representatives might produce verification scores that do not adequately represent the 

quality of meteorological modeling simulation (Mass, 2002). It should also be pointed out 

that air quality model performance evaluation serves as an additional check on how 

accurately the meteorological model was able to capture the observed atmospheric 

dynamics during a particular time period. In an unlikely event of an unusually poor air 

quality model performance, it is reasonable to further investigate the performance of 

meteorological model. 

A more detailed description of the meteorological model performance can be found in 

Appendix R. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Monthly Average Temperature Bias

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

0.60

January

Feburary

March

April

May

June

July

August

September

October

November

December

Bias (degree K)

Monthly Average Humidity Bias

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

January

Feburary

March

April

May

June

July

August

September

October

November

December

Bias (g/kg)

Figure 4-1: Monthly averaged Bias statistics for 2-m temperature and humidity 

76 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 4-3: Monthly averaged statistics for the region of the 12-km modeling domain in and around G

77 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

78 

4.2 CMAQ Air Quality Model Performance Evaluation 

The model performance methodology outlined in EPA's modeling guidance (EPA, 2007) 

is used as a guide for evaluating air quality model performance. EPD has evaluated the 

model performance of 1-hr and 8-hr average ozone concentrations as well as other 

important precursor concentrations. It should be noted that model performance evaluated 

against observational data recorded at the finest temporal resolution at which air quality 

predictions are available (i.e., 1-hour average concentrations) provides a more stringent 

test of the model's ability to replicate pollutant concentrations compared to an evaluation 

that uses temporal averages (e.g., 8-hour average concentrations). EPD believes that the 

comparison of observed and predicted concentration from the grid cell that "contains" the 

monitoring station is a more rigorous test (i.e., finest spatial resolution at which air 

quality concentrations are available) than a test that utilizes predicted concentrations from 

"nearby" grid cells. Therefore, all statistics described below utilize the predicted 

concentration from the grid cell that "contains" the monitoring station. In addition, the 

model performance evaluation presented here will focuses on the model's ability to 

capture pollutant dynamics during the episode. The following sections describe the 

methodology used in evaluating the adequacy of the air quality model results for 

regulatory purposes and the results of the model performance evaluation. Summary of 

evaluation results are presented here for the purpose of brevity and the full model 

performance statistics and graphics for the 1-hour and 8-hour metric have been provided 

in Appendix B, C, D, and E. The spatial coverage of the performance evaluation contains 

monitors in the 20 nonattainment counties around Atlanta. The temporal coverage is 

from May 1, 2002 to September 30, 2002 EST. Since our modeling started April 27, 

2002 UTC, our evaluation excluded 3 days and 5 hours in the modeling outputs as the 

spin-up periods. 

4.2.1 Air Quality Modeling Evaluation Methodology 

The traditional statistical performance metrics are the Mean Normalized Bias (MNB) and 

Mean Normalized Gross Error (MNGE). These statistics were estimated for hourly 

ozone, 8-hour averaged ozone, daily peak hourly ozone, and daily peak 8-hour ozone 

predictions at the monitoring station. In addition, we adopted 10 other statistical metrics 

for hourly observation-prediction pairs suggested by the EPA modeling guidance. The 

mathematical formulation of these metrics is provided in Table 4-4. As the EPA 

modeling guidance recommends, two observation based cut-off values (0 ppb and 60 

ppb) were used for 1-hr and 8-hr MNB and MNGE. For the 60 ppb cut-off case, 

whenever the observation is smaller than the cut-off value, the prediction-observation 

pair is excluded from the calculation. For daily peak hourly ozone MNB and MNGE, 

daily peak 8-hour ozone MNB and MNGE, and the 10 additional metrics that were 

looked at, only a 60 ppb cut-off was used. All metrics were estimated for daily averages 

over 11 monitoring stations in the 20 counties near Atlanta. Also, the daily MNB and 

MNGE averaged over the entire evaluation period were calculated at each monitor. The 

EPA guidance recommends no "bright line" performance goals and encourages states to 

use a "Weight of Evidence" approach to assess the validity of a specific model 

application and to compare their evaluation results with the results from similar modeling 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

79 

exercises. Since the modeling guidance has only two evaluation result examples for 

ozone modeling in its reference modeling exercises, EPD used the previous 1-hour ozone 

performance criteria as a reference: ± 5-15% for MNB and 30-35% for MNGE. 

The above-mentioned statistical analysis is followed by graphical analyses of daily 8-

hour maximum ozone concentrations to visualize the predicted ozone fields against 

observations. Spatial performance analysis was conducted with a series of PAVE tile 

plots with observations overlaid. This helps to understand the dynamics of pollutant 

plumes in the region and helps to diagnose performance issues related to individual 

monitors. For example, poor model performance at a monitoring station might be related 

to the displacement of a plume due to an error in wind direction. In this analysis, the 

spatial coverage included all monitors in Georgia and some monitors in neighboring 

states. 

In addition to the spatial analysis, graphical analyses were performed at each monitor 

site. Graphical measures include daily peak concentration bar plots of predicted and 

observed hourly concentrations, time series plots, and scatter plots. These analyses help 

to evaluate how well the model replicates the observed hourly concentration at the same 

time and location as the observed value. Problems with diurnal variation in predicted 

concentrations are readily apparent in a time series plot. In these graphical analyses, we 

extended our spatial coverage to all Georgia monitors to include monitors outside of the 

Atlanta 20 county nonattainment area. Since an accurate prediction of ozone precursor 

species is as important as ozone itself, model performance for nitrogen monoxide (NO), 

nitrogen dioxide (NO2), carbon monoxide (CO) and selected VOC species including 

isoprene was also conducted. The CB-IV chemical mechanism used in the modeling, 

lumps individual VOCs species into modeled VOC species. Often, it is very difficult to 

properly evaluate the modeled VOCs species because one lumped VOC species represent 

several individual VOC species. Therefore, this evaluation focuses on explicit species 

plus some proxy species. Following is the list of VOCs that were examined: ISOP 

(isoprene), ETH (ethylene), FORM (formaldehyde), OLE (double bonds in hydrocarbon), 

TOL (toluene), XYL (xylene), CO (carbon monoxide). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 4-4: Performance Statistics 

Metrics Formulation 

Mean Normalized Bias (%) ( ) %100 1

1

× − ∑=

N

i Obs

Model Obs

N

Mean Normalized Gross Error (%) %100 1

1

× − ∑=

N

i Obs

Model Obs

N

Mean Observation (ppb) ∑=

N

i

Obs

N 1

1

Mean Prediction (ppb) ∑=

N

i

Model

N 1

1

Ratio of the Means ∑=

N

i Obs

Model

N 1

1

Mean Bias (ppb) ∑=

−

N

i

Model Obs

N 1

( ) 1

Normalized Mean Bias (%) %100

( )

1

1 ×

−

∑

∑

=

=

N

i

N

i

Obs

Model Obs

Mean Fractional Bias (%) %100

( )

(2 )

1

×⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

+

− ∑=

N

i Model Obs

Model Obs

N

Mean Error (ppb) ∑=

−

N

i

Model Obs

N 1

1

Normalized Mean Error (%) %100

1

1 ×

−

∑

∑

=

=

N

i

N

i

Obs

Model Obs

Mean Fractional Error (%) %100

( )

2

1

×⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

+

− ∑=

N

i Model Obs

Model Obs

N

Correlation Coefficient 

∑ ∑

∑

= =

=

− −

− −

N

i

N

i

N

i

Model Model ObsObs

Model ObsObsModel

1 1

2 2

1

( )()

( )( )

80 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

81 

4.2.2 Air Quality Modeling Evaluation Results 

A total of 11 monitors are located within the 20 counties around Atlanta and the 

maximum number of observation-prediction pairs to estimate statistical performance 

measures was 3672 pairs per monitor. The percentage of valid 1-hour ozone observation 

out of this maximum possible number of pairs was over 97 % for all monitors and EPD 

believes this should be sufficient to make the statistical/graphical evaluation meaningful. 

MNB and MNGE for 8-hour ozone and 1-hour ozone with 0 ppb and 60 ppb cutoff are 

shown in Table 4-5 and Table 4-6. For quick graphical examination, these metrics with a 

60 ppb cutoff are also depicted in Figure 4-2. Time series of daily MNB and MNGE (60 

ppb cutoff) averaged over the 11 Atlanta monitors are shown in Figure 4-3 through 

Figure 4-6. During the modeling period, the model showed good performance with most 

days showing MNB less than ±15% and MNGE less than 30%. Days with poor 

performance were typically days with low ozone concentrations. 

The daily maximum 1-hour and 8-hour ozone is captured reasonably well by the model. 

As shown in Table 4-7, Figure 4-7(a), and Figure 7(b), the MNB for the daily maximum 

1-hour and daily maximum 8-hour ozone range from [–4.9% to +5.1%] and [–2.5% to 

+10.7%] across the 11 Atlanta monitors. The MNGE for daily maximum 1-hour and 

daily maximum 8-hour ozone range from [10.4% to 12.2%] and [8.6% to 13.1%] across 

the 11 Atlanta monitors. Time series of spatially averaged MNB and MNGE for daily 

peak 1-hour and 8-hour ozone concentrations are shown in Figure 4-8 through Figure 4-

11. Overall, the model captures daily peak ozone concentrations reasonably well except 

for a few low ozone days. 

Table 4-8 summarizes the additional 10 statistical metrics for observation-prediction pairs 

with observed 8-hour ozone concentrations over 60 ppb. In terms of these additional 

metrics, the model showed reasonable performance at each monitor sites. For example, 

FBIAS ranged from [-5.3% to 10.6%] and FERROR ranged from [9.9% to 14.5%] across 

the 11 Atlanta monitors. Since the Confederate Avenue monitor (GA-Fulton-0055) is of 

particular concern, additional metrics were examined. For example, the RATIO (1.07) 

and BIAS (-3.3 ppb) is considered to be good model performance. Other metrics were 

also close to values found at the other monitors. 

 

All the graphical measures that were examined are included in Appendix B, C, D, and E. 

A brief summary of the findings is presented here. Since the Confederate Avenue 

monitor had the highest 2002 design value, the site-specific summary will focus on this 

site. 

Figure 4-12 contains an example plot showing the spatial distribution of modeled ozone 

concentrations with observations overlaid. This particular day was chosen since June 12, 

2002 was the day when the Confederate Avenue monitor showed its highest ozone 

concentrations in 2002. As shown in the figure, the simulation captures the high ozone 

concentration distribution around Atlanta reasonably well. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

82 

Figure 4-13 is an example of the daily peak concentration analyses. Daily peak 

concentrations of 8-hour ozone, 1-hour ozone, and NO2 are listed from top to bottom of 

Figure 4-13. The x-axis contains monitor sites and all monitors are sorted from west to 

east to capture any geographical biases in our simulation. The simulation showed good 

performance at monitors in counties near Atlanta while it showed a noticeably low bias in 

ozone at monitors downwind of Fulton and DeKalb counties. 

Figure 4-14 is an example of a weekly time series plot for hourly ozone concentration at 

the Confederate Avenue site. In general, the simulation replicated the diurnal ozone 

pattern reasonably well. However, there were hours when the model showed high biases, 

especially during the nighttime hours. To examine possible precursor biases associated 

with these nighttime ozone biases, we created additional time series analyses for 

precursors species at sites near the Confederate Avenue site. 

Figure 4-15 is an example of a monthly scatter plot for 8-hour ozone concentrations at the 

Confederate Avenue site. This plot shows that the model predicted the higher 8-hour 

ozone concentrations in June 2002 reasonably well. The lower ozone concentrations tend 

to be over-predicted, but these predictions typically occur during the nighttime hours. 

Based on the statistics and graphics presented in this document and the Appendix, EPD 

has concluded that the CMAQ modeling used in the attainment demonstration is able to 

captures the peak 8-hour ozone concentrations and is acceptable for regulatory purposes. 

Table 4-5: Mean Normalized Bias and Mean Normalized Gross Error for 8-hour 

ozone from CMAQ 12km simulations temporally averaged from May 1, 2002 to 

September 30, 2002 (8-hour O3 > 0 ppb and 8-hour O3 > 60 ppb). 

8-hour O3 > 0 ppb 8-hour O3 > 60 ppb 

SITE MNB MNGE 

Number of 

observationprediction 

pairs used 

MNB MNGE 

Number of 

observationprediction 

pairs used 

GA-Fulton-0055 95.2 102.6 3636 -4.2 11.0 428

GA-Rockdale-0001 126.8 129.4 3558 -2.3 9.8 419

GA-Douglas-0004 52.8 57.6 3672 -2.6 11.0 559

GA-Fayette-0001 167.5 168.1 3672 12.5 16.1 263

GA-Cobb-0003 97.0 102.5 3672 -2.5 12.9 463

GA-Gwinnett-0002 128.0 132.1 3666 -3.0 10.1 406

GA-Henry-0002 111.1 113.5 3666 -0.2 11.5 373

GA-Coweta-0002 135.1 136.7 3666 0.7 11.7 335

GA-DeKalb-0002 187.4 190.4 3627 0.3 11.1 328

GA-DeKalb-3001 64.0 72.0 3672 -3.1 12.3 436

GA-Paulding-0003 28.7 34.4 3651 -2.1 11.6 576
The Atlanta Eight-Hour Ozone Attainment Demonstration 

83 

Table 4-6: Mean Normalized Bias and Mean Normalized Gross Error for 1-hour 

ozone from CMAQ 12km simulations temporally averaged from May 1, 2002 to 

September 30, 2002 (O3 > 0 ppb and O3 > 60 ppb). 

1-hour O3 > 0 ppb 1-hour O3 > 60 ppb 

SITE MNB MNGE 

Number of 

observationprediction 

pairs used 

MNB MNGE 

Number of 

observationprediction 

pairs used 

GA-Fulton-0055 185.7 200.0 3619 -5.1 14.3 591

GA-Rockdale-0001 247.7 252.6 3549 -4.1 12.4 559

GA-Douglas-0004 99.2 107.1 3641 -3.0 13.6 656

GA-Fayette-0001 300.5 302.4 3643 7.2 13.9 405

GA-Cobb-0003 187.2 196.7 3646 -2.0 15.1 619

GA-Gwinnett-0002 243.4 250.9 3643 -2.5 11.9 616

GA-Henry-0002 225.0 229.6 3641 -1.8 12.4 522

GA-Coweta-0002 261.3 264.6 3645 -0.7 12.7 507

GA-DeKalb-0002 349.2 356.9 3597 -1.0 13.3 501

GA-DeKalb-3001 122.3 136.7 3645 -2.1 14.2 616

GA-Paulding-0003 38.7 46.7 3625 -3.3 13.4 643

Table 4-7: Mean Normalized Bias and Mean Normalized Gross Error of daily 

maximum 1-hour ozone from CMAQ 12km simulations temporally averaged from 

May 1, 2002 to September 30, 2002 (1-hour O3 > 60 ppb and 8-hour O3 > 60 ppb). 

1-hour O3 > 60 ppb 8-hour O3 > 60 ppb 

SITE MNB MNGE MNB MNGE 

GA-Fulton-0055 -1.8 11.4 -2.5 9.1

GA-Rockdale-0001 -4.6 11.6 -2.4 9.2

GA-Douglas-0004 -2.0 12.1 0.2 9.4

GA-Fayette-0001 5.6 11.0 10.7 13.1

GA-Cobb-0003 0.2 11.7 0.7 11.0

GA-Gwinnett-0002 0.7 10.5 -0.6 8.6

GA-Henry-0002 -2.9 10.9 0.0 10.0

GA-Coweta-0002 -0.4 12.2 2.0 11.6

GA-DeKalb-0002 0.5 10.4 1.9 9.4

GA-DeKalb-3001 -0.4 10.4 1.1 9.9

GA-Paulding-0003 -4.9 11.6 -1.1 9.4
The Atlanta Eight-Hour Ozone Attainment Demonstration 

84 

Table 4-8: Mean Observation (MO), Mean Prediction (MP), Ratio of the Means 

(RATIO), Mean Bias (BIAS), Normalized Mean Bias (NMB), Mean Fractional Bias 

(FBIAS), Mean Error (ERR), Normalized Mean Error (NME), Mean Fractional 

Error (FERROR), and Correlation Coefficient (r) of 8-hour ozone from CMAQ 

12km simulation temporally averaged from May 1, 2002 to September 30, 2002 (8-

hour O3 > 60 ppb). 

SITE MO MP RATIO BIAS NMB FBIAS ERR NME FERROR r 

GA-Fulton-0055 73.2 70.0 1.07 -3.3 -4.5 -5.3 8.0 11.0 11.6 0.48

GA-Rockdale-0001 72.7 70.7 1.04 -2.0 -2.8 -3.0 7.1 9.8 9.9 0.49

GA-Douglas-0004 73.7 71.4 1.05 -2.2 -3.0 -3.6 8.1 11.0 11.3 0.37

GA-Fayette-0001 70.3 79.0 0.91 8.8 12.5 10.6 11.3 16.1 14.5 0.43

GA-Cobb-0003 72.7 70.6 1.05 -2.2 -3.0 -3.9 9.2 12.7 13.2 0.31

GA-Gwinnett-0002 69.9 67.6 1.05 -2.3 -3.3 -3.8 7.0 10.0 10.4 0.30

GA-Henry-0002 72.9 72.5 1.02 -0.4 -0.6 -1.3 8.4 11.5 11.6 0.50

GA-Coweta-0002 71.7 71.5 1.01 -0.2 -0.2 -0.3 8.4 11.8 11.6 0.22

GA-DeKalb-0002 71.8 71.9 1.02 0.1 0.1 -0.7 7.8 10.9 11.0 0.43

GA-DeKalb-3001 71.6 69.1 1.06 -2.5 -3.5 -4.5 8.8 12.2 12.8 0.27

GA-Paulding-0003 72.6 70.6 1.05 -2.0 -2.7 -3.3 8.5 11.6 12.0 0.30
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-2(a): Mean Normalized Bias for 1-hour and 8-hour ozone concentrations of CMAQ 12 km simulation at 11 

counties around Atlanta. 

85 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-2(b): Mean Normalized Gross Error for 1-hour and 8-hour ozone concentrations of CMAQ 12 km simulation 

20 counties around Atlanta. 

86 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-3: Daily Mean Normalized Bias over 20 counties around Atlanta for observed 1-hour O3 > 60 

MO stands for mean observation. Red dash line indicates performance reference, 

±15 %. 

87 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-4: Daily Mean Normalized Gross Error over 20 counties around Atlanta for observed 1-hour O3 > 

MO stands for mean observation. Red dash line indicates performance reference, 

±35 %. 

88 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-5: Daily Mean Normalized Bias over 20 counties around Atlanta for observed 8-hour O3 > 60 

MO stands for mean observation. 

89 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-6: Daily Mean Normalized Gross Error over 20 counties around Atlanta for observed 8-hour O3 > 

MO stands for mean observation. 

90 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-7(a): Mean Normalized Bias for daily maximum 1-hour and 8-hour ozone concentrations of CMAQ 12 km sim

sites in 20 counties around Atlanta. 

91 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-7(b): Mean Normalized Gross Error for daily maximum 1-hour and 8-hour ozone concentrations of CMAQ 12 

monitor sites in 20 counties around Atlanta. 

92 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-8: Daily Mean Normalized Bias over 20 counties around Atlanta for daily maximum 1-hour O3 (paire

MO stands for mean observation. 

93 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-9: Daily Mean Normalized Gross Error over 20 counties around Atlanta for daily maximum 1-hour O3 (p

MO stands for mean observation. 

94 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-10: Daily Mean Normalized Bias over 20 counties around Atlanta for daily maximum 8-hour O3 (pair

MO stands for mean observation. 

95 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-11: Daily Mean Normalized Gross Error over 20 counties around Atlanta for daily maximum 8-hour O3 (

MO stands for mean observation. 

96 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Confederate 

Avenue 

Monitor 

Figure 4-12: Tile plot of daily 8-hour maximum ozone concentrations on June 12, 2002. 

97 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-13(a): Bar plots for daily maximum concentrations of 8-hour ozone. 

All monitors were sorted from west to east to capture any spatial biases. Red bars indicate observed concentra

indicate predicted concentrations. Data points for this figure were sampled from 6 AM to 5 PM on Jun

98 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-13(b): Bar plots for daily maximum concentrations of 1-hour ozone. 

All monitors were sorted from west to east to capture any spatial biases. Red bars indicate observed concentra

indicate predicted concentrations. Data points for this figure were sampled from 6 AM to 5 PM on Jun

99 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-13(c): Bar plots for daily maximum concentrations of nitrogen dioxides. 

All monitors were sorted from west to east to capture any spatial biases. Red bars indicate observed concentra

indicate predicted concentrations. Data points for this figure were sampled from 6 AM to 5 PM on Jun

100 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-14: Weekly time series plot for hourly ozone concentration at the Confederate Avenue 

The red line represent observed ozone concentrations and the blue line represents the modeled ozone concentr

shows hours from midnight of June 10, 2002 (Monday) to midnight of June 17, 2002 (Monday

101 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 4-15: Scatter plot of 8-hour ozone concentrations at the Confederate Avenue site. 

Data points are from observed and modeled 8-hour concentrations in June 2002. 

102 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

103 

5.0 CONTROLS APPLIED 

This chapter presents an analysis of NOx and VOC emissions control measures 

considered in this attainment demonstration. As discussed in Chapter 3, ozone precursors 

of VOC and NOx can come from man-made (anthropogenic) sources as well as naturally 

occurring sources. Significant reductions in man-made sources of VOC and NOx were 

achieved via state and federal regulatory and voluntary control measures for attainment of 

the 1-hour ozone NAAQS. This set of existing requirements and voluntary efforts served 

as the basis for considering further control measures. 

Since the metro Atlanta region is also designated nonattainment for the federal PM2.5 

standards, control strategies for PM2.5 and the 8-hour ozone NAAQS will be integrated 

and harmonized to the extent possible. 

Attaining the federal 8-hour ozone NAAQS will require the involvement of all sectors of 

Georgia's economy and population. Tables 5-1 and 5-2 summarize NOx emissions for 

the 20 county nonattainment area for the base year of 2002 and future year 2009. 

Table 5-1: NOx Emissions for 20 County Nonattainment Area – Part 1 

Inventory 2002 2009 

Category tpd % of total tpd % of total 

Point 119.31 17.7 69.47 15.2 

Area 33.85 5.0 35.07 7.7 

On-Road 405.06 60.1 250.43 54.7 

Non-Road 116.23 17.3 103.25 22.5 

Table 5-2: NOx Emissions for 20 County Nonattainment Area – Part 2 

2002 

(tpd) 

2009 

(tpd) Inventory 

Category 

SubCategory 

(See table 3-6 for 

acronyms) 

Category Contributions

from subcategory 

Category Contributions 

from subcategory 

On-Road 405.06 250.43 

HDDV 213.79 121.25 

LDGV 80.01 37.01 

LDGT 1&2 55.21 52.35 

HDGV 29.98 16.02 

LDGT 3&4 24.36 22.57 

LDGM 0.90 0.94 

LDDT 0.61 0.25 

LDDV 0.20 0.04 

Point 119.31 69.47 

EGUs 104.13 58.02 

Non-EGUs 15.18 11.45 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

104 

Tables 5-3 and 5-4 summarize anthropogenic VOC emissions for the 20 county 

nonattainment area for the base year of 2002 and future year 2009. 

Table 5-3: VOC Emissions for 20 County Nonattainment Area – Part 1 

Inventory 2002 2009 

Category tpd % of total Tpd % of total 

Point 20.86 3.4 19.41 4 

Area 251.69 41.2 232.7 47 

On-Road 219.98 36.0 153.33 31 

Non-Road 118.03 19.4 85.46 18 

Table 5-4: VOC Emissions from for 20 County Nonattainment Area – Part 2 

2002 

(tpd) 

2009 

(tpd) Inventory 

Category 

SubCategory 

(See table 3-6 for 

acronyms)

Category Contribution 

from subcategory 

Category Contribution 

from subcategory 

Area 251.69 232.7 

On-Road 219.98 153.33 

LD Gas Veh 100.81 51.00 

LDGT 1 &2 78.58 70.65 

LDGT 3&4 21.73 18.04 

HDDV 8.58 6.39 

HDGV 7.73 4.93 

LDGM 2.11 2.17 

LDDT 0.35 0.14 

LDDV 0.09 0.02 

This control measures analysis focuses on identifying possible modifications to existing 

control measures (i.e., 2002 base year emissions) in order to help the metro Atlanta area 

attain the ozone standard by June 15, 2010. This analysis draws heavily on the RACT 

analysis described in Chapter 10. 

5.1 Control Measures Analyses for Stationary Point and Area Sources 

The federal government has promulgated regulations, in accordance with Clean Air Act 

requirements, to reduce emissions of NOx and VOC from stationary point and area 

sources. In most cases Georgia EPD has been granted delegation of authority to 

implement and enforce such regulations for stationary sources. 

The legal authority to regulate NOx and VOC emissions from stationary point and area 

sources comes from sections 111, 112, 172(c), 182(a), 182(b)(2), and 182(f) of the CAA. 

Section 111 emission standards are referred to as New Source Performance Standards 

[NSPSs] and Georgia EPD has been delegated authority to implement and enforce such 

standards per Georgia Rule 391-3-1-.02(8). The NSPSs specify emission standards 

and/or work practice standards from equipment whose date of construction (or 

manufacture) meets the specific timelines for most criteria air pollutants including VOC 

and NOx. Section 112 establishes, in part, National Emission Standards for Hazardous 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

105 

Air Pollutants [NESHAPs] and Georgia EPD has been delegated authority to implement 

and enforce such standards per Georgia Rule 391-3-1-.02(9) for major sources of 

hazardous air pollutants [HAPs]. EPA has promulgated NESHAPs for area sources. 

Georgia EPD has taken delegation of some of these standards. Decisions are still 

pending as to who, Georgia EPD or U.S. EPA, will implement and enforce the remaining 

standards. The Section 112 standards cover HAPs and many VOCs are also HAPs. 

Sections 172(c), 182(a), 182(b)(2), and 182(f) require implementation of control 

measures that satisfy Reasonably Available Control Measures [RACM] and Reasonably 

Available Control Technology requirements for VOC and NOx emissions. Control 

measures for VOC and NOx emissions that satisfy these requirements are promulgated in 

Georgia Rule 391-3-1-.02(2). Chapter 10 provides a detailed discussion of the 

relationship between provisions in Georgia Rule 391-3-1-.02(2) and sections 172(c), 

182(a), 182(b)(2), and 182(f). 

VOC emission limitation and standard provisions in Georgia Rule 391-3-1-.02(2) are 

established for various industry sectors and consist of emission limits, work practice 

standards, compliant coating limits, and/or air pollution control requirements. The 

majority of these provisions apply statewide based on county-specific VOC emission 

thresholds. The VOC provisions that do not apply statewide apply in the 20 counties that 

make up the metro Atlanta non-attainment area. These VOC provisions apply yearround. 

Table 5-5: Georgia Rule 391-3-1-.02(2) Stationary Source VOC Standards for 

Point, Area, and Mobile Sources 

Subparagraph Category Industry Sector 

Is this sector 

included in 2002 

Base Year 

Inventory? 

(t) Surface Coating Automobile and LightDuty Truck Mfg Yes – Point 

(u) Surface Coating Can Coating Yes – Point 

Yes-Area 

(v) Surface Coating Coil Coating Yes – Point 

Yes-Area 

(w) Surface Coating Paper Coating Yes – Point 

Yes-Area 

(x) Surface Coating Fabric Vinyl Coating Yes – Point 

(y) Surface Coating Metal Furniture Coating Yes – Point 

Yes-Area 

(z) Surface Coating Large Appliance Surface 

Coating 

Yes-Area 

(aa) Surface Coating Wire Coating No 

(bb) Petroleum Liquid Storage Yes – Point 

Yes-Area 

(cc) Bulk Gasoline Terminals Yes-Area 

(dd) Cutback Asphalt No 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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Subparagraph Category Industry Sector 

Is this sector 

included in 2002 

Base Year 

Inventory? 

(ee) Refinery Petroleum Refinery No 

(ff) Degreasing Solvent Metal Cleaning Yes – Point 

Yes-Area 

(hh) Refinery Petroleum Refinery 

Equipment Leaks 

No 

(ii) Surface Coating Miscellaneous Metal Parts 

and Products 

Yes – Point 

(jj) Surface Coating Flat Wood Paneling No 

(kk) Pharmaceutical Synthesized 

Pharmaceutical Mfg 

Yes-Area 

(ll) Surface Coating Manufacture of Pneumatic 

Rubber Tires 

Yes – Point 

(mm) Printing Graphic Arts Systems Yes – Point 

Yes-Area 

(nn) Storage Tanks External Floating Roof 

Tanks 

Yes – Point 

(pp) Bulk Terminals Bulk Gasoline Plants No 

(qq) Dry Cleaning Large Petroleum Dry 

Cleaners 

Yes-Area 

(rr) Gasoline 

Dispensing 

Gasoline Dispensing 

Facility – Stage I 

Yes-Area 

(ss) Gasoline Transport Gasoline Transport 

Vehicles and Vapor 

Collection Systems 

Yes – Point 

(tt) NA Case-by-Case for Major 

Sources 

No 

(vv) Breathing Losses Volatile Organic Liquid 

Handling and Storage 

Yes – Point 

(zz) Gasoline 

Dispensing 

Gasoline Dispensing 

Facilities – Stage II 

Yes – Point 

(aaa) Windshield Wiper 

Fluid 

Consumer and Commercial 

Products 

No 

(bbb) Gasoline Marketing No 

(ccc) General-Industry Bulk Mixing Tanks No 

(ddd) Printing Offset Lithography Yes – Point 

(eee) Polystyrene 

Production 

Expanded Polystyrene 

Products Mfg 

Yes – Point 

(hhh) Surface Coating Wood Furniture Finishing 

and Cleaning Operations 

Yes-Area 

(kkk) Surface Coating Aerospace Mfg and 

Rework Facilities 

Yes – Point 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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NOx emission limitation and standard provisions in Georgia Rule 391-3-1-.02(2) are 

established for various external and internal combustion devices and consist of emission 

standards and work practice requirements. All of these provisions, except for Rules 391-

3-1-.02(2)(yy) and (rrr) already applied to the 20-county 8-hour ozone metro Atlanta area 

in 2002. Applicability of Rules (yy) and (rrr) were expanded from 19 (all but Barrow 

County) to all 20 nonattainment counties in 2008. Coal-fired external combustion 

devices that generate steam for electricity generation are regulated under Georgia Rule 

391-3-1-.02(2)(jjj) for NOx emissions. These devices are also classified as “affected 

units” under regional control measures discussed later in this chapter. Georgia Rule (jjj) 

establishes a more stringent NOx emission standard beginning May 1, 2003. Georgia 

EPD estimated that NOx emissions from point sources would be reduced by 

approximately 42% as a whole between 2002 and 2009. As illustrated earlier, the 

majority of NOx emissions from point sources comes from coal-fired external 

combustion devices that generate steam for electricity generation. There are three such 

plants in the 20-county metro Atlanta area under analysis and 4 such plants near this area. 

The plant in Cobb County [i.e., Georgia Power Plant McDonough] will be converted to a 

natural gas combined-cycle plant which will result in a major decrease in NOx emissions. 

Table 5-6: Georgia Rule 391-3-1-.02(2) Stationary Source NOx Standards for Point 

and Area Sources 

Subparagraph Category Industry Sector 

Is this sector 

included in 2002 

Base Year 

Inventory? 

(yy) Case-by-Case RACT for 

Major Sources 

No 

(jjj) Electricity 

Generation 

Electric Utility Steam 

Generating Units 

Yes-Point 

(lll) Fuel-Burning Fuel-Burning Equipment Yes-Point 

Yes-Area 

(mmm) Electricity 

Generation 

Stationary Gas Turbines 

and Stationary Engines 

Used to Generate 

Electricity 

Yes – Point 

Yes - Area 

(nnn) Electricity 

Generation 

Large Stationary Gas 

Turbines 

Yes-Point 

(rrr) Fuel-Burning Small Fuel-Burning 

Equipment 

Yes - Area 

EPD had determined that several large point sources were significant contributors and 

that additional controls and NOx reductions were deemed available. The negotiated 

controls and associated NOx reductions are specified for the following facilities in their 

Title V air quality permits. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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Table 5-7: Specific Large Point Source Control Measure – Lafarge Building 

Materials, Inc. 

Plant Name and Location AIRS No. 

Lafarge Building Materials, Inc. – Atlanta 

Plant (formerly Blue Circle Cement) 

Atlanta (Fulton County) 

04-13-121-00401 

Effective May 1, 2003, in addition to any existing emission limits which apply to Rotary 

Kiln No. 1 (Source Code EU303), the Permittee shall comply with the limits on 

emissions of nitrogen oxides (NOx) in the following table during the period May 1 

through September 30 of each year: 

NOx Emission Limit During Which No Clinker is Produced for Special Products (tires 

continuously injected into kiln) = 235 lb/hr rolling 30-day average 

NOx Emission Limit During Which Clinker is Produced for Special Products (no tires 

injected into kiln) = 268 lb/hr rolling 30-day average 

The averaging periods shall consist of thirty consecutive operating days. 

CONDITION: Effective May 1, 2003, during the period May 1 through September 30 of 

each year: 

• Except as provided below, the Permittee shall burn tires, as supplemental fuel, in kiln 

No. 1 at all times that the kiln is in operation. 

• While the kiln is in operation, periods during which tires are not burned in kiln No. 1 

shall not exceed 10 days per 30-day averaging period. The averaging periods shall 

consist of thirty consecutive operating days. 

Lafarge Building Materials has ceased to operate as of December 31, 2006 and is 

reflected in the 2009 inventory. 

Table 5-8: Specific Large Point Source Control Measure – Transco Compressor 

Station 120 

Plant Name and Location AIRS No. 

Transco Compressor Station 120 

Stockbridge (Henry County) 

04-13-151-00025 

Their Title V Permit specifies an ozone season NOx limit, effective May 1, 2003, of 6.0 

grams per horsepower-hour for all fifteen of its mainline internal combustion engines 

(Source Codes: ML01, ML02, ML03, ML04, ML05, ML06, ML07, ML08, ML09, 

ML10, ML11, ML12, ML13, ML14, and ML15). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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Table 5-9: Specific Large Point Source Control Measure – Caraustar Industries, 

Inc. 

Plant Name and Location AIRS No. 

Caraustar Industries, Inc. (formerly Austell 

Box Board) 

Austell (Cobb County) 

04-13-067-00022 

CONDITION: The Permittee shall not discharge or cause the discharge into the 

atmosphere from the Coal-Fired Boiler (Source Code: CB01), any gases which contain 

NOx emissions in excess of the following: 

• 0.38 pounds NOx per million BTU heat input during the period from May 1 through 

September 30 of each year, determined on a thirty day rolling average. 

• Compliance date was as early as 1999. 

NOx emissions have been reduced because the Acid Rain Program set NOx emission 

standards for certain coal-fired utility boilers across the U.S., including Georgia. The 

Acid Rain NOx program was implemented in two phases, beginning in 1996 and 2000. 

Phase I of the NOx program began on January 1, 1996 and applied to two types of boilers 

(which were already targeted for Phase I SO2 reductions): dry-bottom wall-fired boilers 

and tangentially fired boilers. Dry-bottom wall-fired boilers had to meet a limitation of 

0.50 pounds of NOx per million BTU averaged over the year, and tangentially fired 

boilers had to achieve a limitation of 0.45 pounds of NOx per million BTU, again, 

averaged over the year. 

Phase II of the NOx program began in 2000. These regulations: 

• Set lower emission limits for Group 1 boilers first subject to an acid rain emissions 

limitation in Phase II, and 

• Established initial NOx emission limitations for Group 2 boilers, which include 

boilers applying cell-burner technology, cyclone boilers, wet bottom boilers, and 

other types of coal-fired boilers. 

Most of the affected units in Georgia were also subject to a state NOx emission standard 

(Georgia Rule 391-3-1-.02(2)(jjj)) which in some cases imposed a more stringent NOx 

emission standard during the same time frame. 

Regional transport of NOx and VOC emissions (and ozone) contribute to a certain degree 

to the ozone problem in the metro Atlanta area. Regional transport [a.k.a. interstate 

transport] is covered under section 110(a)(2)(D) of the CAA. The NOx SIP Call is a 

NOx budget trading program using a market-based cap and trade program created to 

reduce emissions of nitrogen oxides (NOx) from power plants and other large combustion 

sources in the eastern United States in an effort to mitigate significant transport of NOx

from those affected facilities that contribute to ozone nonattainment areas in other states. 

EPA has promulgated these control measures to address ozone season NOx emissions in 

40 CFR Part 96 Subpart A through I. The NOx SIP Call control measures aided states in 

addressing interstate transport under the 1-hour ozone NAAQS. Georgia is not subject to 

the NOx SIP Call; however, upwind areas outside of the state are subject to these control 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

110 

measures. Georgia EPD included NOx SIP Call control measures in upwind areas 

(located out of the state) in its ozone modeling. 

EPA adopted the Clean Air Interstate Rule (CAIR) in order to reduce interstate transport 

of ozone and PM2.5 precursors from states that significantly contributed to downwind 8-

hour ozone and PM2.5 nonattainment areas. CAIR is a market-based cap and trade 

program that consisted of both a seasonal NOx program (for states that significantly 

contributed to downwind 8-hour ozone nonattainment areas) and annual NOx and SO2 

program (for states that significantly contributed to PM2.5 nonattainment areas. The 

seasonal NOx program replaced the NOx SIP Call. EPA promulgated CAIR control 

measures to address annual NOx emissions in 40 CFR Part 96. EPA required that 

Georgia submit a CAA Section 110(a)(2)(D)(i) [referred to as "interstate transport"] SIP 

revision to address its need to eliminate significant contribution to North Carolina and 

other applicable downwind states [and/or its need to eliminate interference] as it relates to 

the new PM2.5 NAAQS. EPD submitted this SIP revision to EPA on March 30, 2007, 

and in this SIP revision EPD adopted by referenced (with allowed flexibility) the CAIR 

Rule (40 CFR Part 96 Subparts AA-II for NOx Program and 40 CFR Parts 96 Subparts 

AAA-III for SO2 Program) as the control strategy for eliminating significant contribution

to applicable downwind states as it relates to the PM2.5 NAAQS. One aspect of this 

control strategy is the need to meet a state annual NOx allowance via a nation-wide capand-trade program. 

The CAIR Rule will require certain states, whose ozone season NOx emissions are 

considered to significantly contribute to the 8-hour ozone attainment problem in Atlanta, 

to reduce their ozone season NOx emissions. Georgia is not subject to the seasonal NOx 

program, but compliance by affected units in Georgia with the annual NOx allowance for 

the PM2.5 NAAQS should also contribute to reductions in local emissions of NOx during 

the ozone season. 

The CAIR applies to (1) any stationary, fossil-fuel-fired boiler or stationary, fossil-fuelfired combustion turbine serving at any time, since the start-up of a unit's combustion 

chamber, a generator with a nameplate capacity of more than 25 MWe producing 

electricity for sale and (2) for a unit that qualifies as a cogeneration unit during the 12-

month period starting on the date that the unit first produces electricity and continues to 

qualify as a cogeneration unit, a cogeneration unit serving at any time a generator with 

nameplate capacity of more than 25 MWe and supplying in any calendar year more than 

one-third of the unit's potential electric output capacity of 219,000 MWh, whichever is 

greater, to any utility power distribution system for sale. 

This rule provide annual state caps for NOx and SO2 in two phases, with the Phase I caps 

for NOx and SO2 starting in 2009 and 2010, respectively. Phase II caps become 

effective in 2015. The U.S.EPA is allowing the caps to be met through a cap and trade 

program if a state so chooses to participate in the program. 

Georgia EPD included local and upwind CAIR control measures in its ozone modeling. 

Georgia EPD implements the CAIR rule in Georgia Rules 391-3-1-.02(12) and 391-3-1-

.02(13). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

111 

5.2 Control Measures Analyses for On-Road Mobile Sources 

On-road mobile sources in the metro Atlanta account for the largest percent of NOx and 

anthropogenic VOC emissions. Air pollution from cars and light-duty trucks comes from 

by-products of the combustion process (exhaust) and from evaporation of the fuel itself. 

Hydrocarbon pollutants escape into the air through fuel evaporation. With today’s 

efficient exhaust emission controls and today’s gasoline formulations, evaporative losses 

can account for a majority of the total hydrocarbon pollution from current model cars on 

hot days when ozone levels are highest. Evaporative emissions occur several ways: 

• Diurnal: Gasoline evaporation increases as the temperature rises during the day, 

heating the fuel tank and venting gasoline vapors. 

• Running Losses: The hot engine and exhaust system can vaporize gasoline when 

the car is running. 

• Hot Soak: The engine remains hot for a period of time after the car is turned off, 

and gasoline evaporation continues when the car is parked. 

• Refueling: Gasoline vapors are always present in fuel tanks. These vapors are 

forced out when the tank is filled with liquid fuel. 

The federal government has promulgated regulations, in accordance with Clean Air Act 

requirements, to reduce emissions of NOx and VOC from on-road mobile sources. States 

(other than California) are pre-empted from implementing and enforcing these regulation. 

In addition, this preemption also prevents states from implementing and enforcing more 

stringent standards or regulating the operation of on-road sources. 

The 1990 Clean Air Act Amendments further reduce vehicle emissions. Mobile source 

provisions include even tighter tailpipe standards, increased durability, improved control 

of evaporative emissions, and computerized diagnostic systems that identify 

malfunctioning emission controls. 

Table 5-10: Federal Control Measures for On-Road Mobile Sources 

Statutory Requirement Federal Regulation Description of Control 

Measure 

Sections 182(b)(3) and 

202(a)(6) 

40 CFR Part 86 New Vehicle On-Board 

Vapor Recovery System 

Title II Part A – Sections 

202 through 219 that pertain 

to on-road mobile sources. 

Includes certain portions of 

40 CFR Parts 85 and 86. 

Motor Vehicle Emission 

and Fuel Standards: 

Includes Tier 0, 1, and 2 

emission standards. Tier 2 

standards begin 2004. 

Includes RVP requirements; 

Includes fuel sulfur content 

requirements 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

112 

Table 5-10: Federal Control Measures for On-Road Mobile Sources 

Statutory Requirement Federal Regulation Description of Control 

Measure 

Includes lead substitute 

gasoline additives 

Section 211(l) 40 CFR Part 86 Subpart G Regulation of Fuels – 

Detergents. 

Table 5-11: State Authority to Implement Federal Control Measures for On-Road 

Mobile Sources 

Statutory Requirement State Rule Description of Control 

Measure 

Title II Part A 391-3-20 Rules for Enhanced 

Inspection and Maintenance 

Title II Part A 391-3-22 Clean Fuel Fleet Program 

Title II Part A 391-3-1-.02(2) Heavy-Duty Diesel Engine 

Requirements 

Tighter Tailpipe Standards: Tighter tailpipe standards for total hydrocarbons, carbon 

monoxide and NOx were phased in by the 1996 model year fleet. U.S. EPA determined 

that lower standards were warranted in 1999 and the U.S. EPA further tightened the 

tailpipe standards beginning with the 2004 model year vehicles. Because of continued 

growth in the number of vehicles and miles traveled, tailpipe emissions from 

conventional gasoline engines will eventually begin to increase despite improvements in 

emission control systems, unless EPA adopts tighter tailpipe standards for future model 

years. 

Evaporating Gasoline: As a complement to stricter tailpipe standards, the U.S.EPA has 

introduced programs to minimize air pollution from evaporating gasoline. Evaporative 

emissions are a major source of the hydrocarbon compounds that form ground-level 

ozone. To that end the U.S.EPA has established more stringent limits on gasoline 

volatility and the control of hydrocarbon vapors that evaporate during vehicle refueling. 

For example, Section 182(b)(3) of the CAA requires moderate areas to implement Stage 

II gasoline vapor recovery systems unless and until the U.S.EPA promulgates an onboard 

vapor recovery system regulation. On January 24, 1994 EPA promulgated the onboard 

rule. As section 202(a)(6) of the CAA provides that once the rule is promulgated, 

moderate areas are no longer required to implement Stage II. Thus, the Stage II vapor 

recovery requirement is not an applicable requirement for the Atlanta ozone 

nonattainment area. This measure required the installation of onboard refueling 

emissions controls for new passenger cars and light trucks beginning in the 1998 model 

year. The onboard refueling vapor recovery (ORVR) system was required for new 

passenger cars and light trucks beginning in model year 1998. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

113 

Gasoline Deposit Control Program: The accumulation of deposits in the engine and fuel 

supply systems of gasoline motor vehicles can significantly increase emissions of NOx, 

hydrocarbons, and carbon monoxide. Pursuant to the requirements of Section 211(l) of 

the CAA, EPA implemented a gasoline deposit control program which requires that all 

gasoline sold for use in motor vehicles in the US contain additives that are effective in 

limiting the formation of such deposits. Specifically, EPA requires that deposit control 

additives be certified for their ability to control fuel injector deposits and intake valve 

deposits in EPA-specified test procedures. Section 211(l) of the CAA requires that, by 

January 1, 1995, all gasoline must contain detergent additives to prevent the 

accumulation of deposits in motor vehicle engines and fuel supply systems. This CAA 

section also requires EPA to promulgate specifications for the detergent additives. 

Detergent additives prevent the accumulation of engine and fuel supply system deposits 

that have adverse effects on vehicle emissions as well as on fuel economy and drivability. 

In response to section 211(l)'s requirements, EPA published a Notice of Proposed 

Rulemaking (NPRM) on December 6, 1993 (59 FR 64213) proposing a detergent 

additives regulatory program. The detergent program was finalized in two parts. Final 

regulations for the interim detergent program, requiring the use of detergent additives in 

gasoline but not mandating specific detergent efficiency testing,, were published on 

October 14, 1994 (59 FR 54678). Final regulations for the detergent certification 

program, mandating the use of certified detergents with specified detergent efficiency 

testing, were published on July 5, 1996 (61 FR 35310) with an effective date of August 1, 

1997. 

Reformulated Gasoline: By 1995, all gasoline sold in the country’s worst ozone areas 

were required to meet reformulation specifications. EPA estimated that using 

reformulated gasoline would result in reductions in hydrocarbon and air toxic emissions 

as well as NOx emissions. Reformulated gasoline is currently not required for the 

Atlanta ozone nonattainment area. 

Inspection and Maintenance: Georgia EPD is implementing an Enhanced Motor Vehicle 

Inspection and Maintenance Program in accordance with Georgia Rule 391-3-20 in the 

13 counties that make up the former 1-hour ozone Atlanta nonattainment area. This 

action is being taken under section 110 of the CAA and section 348 of the National 

Highway Systems Designation Act. Georgia’s 13-county Inspection and Maintenance 

Program satisfies the Inspection and Maintenance requirement for the 20-county ozone 

nonattainment area. 

Clean Fuel Fleet Program: Georgia EPD is implementing this program in accordance 

with the Clean Air Act; however, this program no longer provides emission reductions 

because the current fleets in use must meet stricter tailpipe standards via 40 CFR Part 86. 

Heavy-Duty Diesel Engine Requirements: These specifications are established in Georgia 

Rule 391-3-1-.02(2)(ooo). This rule requires heavy duty diesel engines (vehicle weight 

of 14001 lbs or more) to meet the California Air Resources Board (CARB) emissions 

standards by 2005. These standards are essentially the same as the federal heavy duty 

engine standards (40 CFR 86, Subpart A) described in the federal control measures 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

114 

section. The CARB heavy duty diesel engine standards were adopted to ensure that the 

emission reductions would be achieved in the event that U.S. EPA relaxed the federal 

requirements and did not require 2005 and 2006 model year engines to meet the Not-ToExceed (NTE) test requirements. The CARB standards and Georgia’s rule (ooo) were 

promulgated prior to the federal standards. The rule was expected to reduce NOx by 13 

tons per day statewide and 8 tons per day in the 45 county Atlanta ozone control area in 

2005. These emissions benefits would potentially have doubled in 2006 if the 

manufacturers continued to not meet the NTE test requirements. Manufacturers were 

required federally to begin testing the engines to the NTE requirements with the 2007 

model year. Georgia has kept the CARB standards in place to prevent a delay in the state 

receiving cleaner engines in the event that EPA were to relax or delay the federal 2007 or 

2010 engine standards. Also, the CARB engine requirements differ from EPA’s in that 

CARB requires a 5 minute idle shutdown or the use of a clean-idle engine beginning with 

the 2008 model year. The benefit of this 5-minute idle limit has not been quantified for 

Georgia. However, it is expected to reduce NOx and PM emissions. 

5.3 Control Measures Analyses for Off-Road Mobile Sources 

The off-road (or nonroad) category covers a diverse collection of engines, equipment, 

vehicles, and vessels. Examples of off-road equipment include outdoor power 

equipment, recreational vehicles, farm and construction machinery, lawn and garden 

equipment, marine vessels, and locomotives. Until the mid-1990s, emissions from these 

engines were largely uncontrolled according to the U.S.EPA. The 1990 amendments to 

the Clean Air Act directed the U.S.EPA to study the contribution of nonroad engines to 

urban air pollution, and regulate them if they contributed to air quality problems. In 

1991, the U.S.EPA published a report showing that nonroad equipment emitted large 

amounts of NOx, hydrocarbons, carbon monoxide and particulate matter. In general, the 

U.S.EPA noted that nonroad engines had total emissions almost as high as highway 

motor vehicles. In addition, diesel particulate matter emissions were significantly higher 

from nonroad equipment than from highway emissions. In response, the U.S.EPA 

adopted emissions standards for most categories of new nonroad engines, and these are 

specified in Table 5-12. 

The federal government has promulgated regulations, in accordance with Clean Air Act 

requirements, to reduce emissions of NOx and VOC from off-road mobile sources. 

States (other than California) are pre-empted from implementing and enforcing these 

regulations. In addition, this pre-emption also prevents states from implementing and 

enforcing more stringent standards or regulate the operation of off-road sources. 

Table 5-12: Federal Control Measures for On-Road Mobile Sources 

Statutory Requirement Federal Regulation Description of Control 

Measure 

Section 231 40 CFR Part 87 Aircraft Engine Standards 

Effective 1974 through 

2005 

Section 213 40 CFR Part 89 Non-Road Diesel Engines 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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Table 5-12: Federal Control Measures for On-Road Mobile Sources 

Statutory Requirement Federal Regulation Description of Control 

Measure 

(Land Based) 

Tier 2 Standards – Effective 

2001 through 2006 

Tier 3 Standards – Effective 

2006 through 2008 

Section 213 40 CFR Part 90 Land-Based Spark Ignition 

Engines 

Phase II – Effective date 

depends on engine class and 

model year. Model years 

covered in Phase II are 

2001 through 2007 

depending on engine class. 

Section 213 40 CFR Part 91 Marine Spark Ignition 

Engines – Effective date 

depends on engine class and 

model year. Model years 

covered are 1998 through 

2006 depending on engine 

class. 

Section 213 40 CFR Part 92 Locomotive and Engines – 

Effective date depends on 

original manufacture date 

and date of remanufacture. 

Effective dates for original 

manufacture range from 

1973 to 2005. 

Tier 1: 2002 through 2004 

Tier 2: 2005 and after 

Section 213 40 CFR Part 94 Diesel Marine Engines 

Tier 1 – 2004 Model Year 

and after. 

Tier 2 – Model Years 2004 

through 2009. 

Section 213 40 CFR Part 1039 Nonroad Diesel Engines 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

116 

Table 5-12: Federal Control Measures for On-Road Mobile Sources 

Statutory Requirement Federal Regulation Description of Control 

Measure 

Model year beginning in 

2008 with other effective 

dates of 2011 and 2012. 

Section 213 40 CFR Part 1048 Large Spark Ignition 

Engines 

January 1, 2004 

Section 213 40 CFR Part 1051 Recreational Vehicles – 

Model year 2006 with 

certain exceptions 

Land-Based Diesel Engines: Equipment included in this category includes: diesel 

engines up to 750 horsepower (hp) used in agriculture, construction, and industry. 

Equipment examples include: asphalt pavers, rollers, scrapers, rubber-tired dozers, 

agricultural tractors, combines, balers, harvesters, and backhoes. Diesel-fueled engines 

in aircrafts, marine vessels, and locomotives are not included in this category. Federal 

regulation 40 CFR Part 89 specifies, in part, NOx emission standards from these engines. 

Federal regulation 40 CFR Part 1039 specifies, in part, fuel sulfur content requirements 

for diesel fuel used in these engines. 

The federal engine NOx exhaust standards were first promulgated in 1994 and again in 

1998. The 1994 NOx exhaust standards are referenced as “Tier 1” standards and these 

standards were phased in years 1996 through 2000. The 1998 NOx exhaust standards 

revised “Tier 1” standards and introduced “Tier 2” and “Tier 3” standards. NOx exhaust 

standards for applicable diesel engines less than 50 hp were phased in from 1999 through 

2006. NOx exhaust standards for applicable diesel engines equal to or greater than 50 hp 

(and less than 750 hp) were phased in from 2001 through 2008. The U.S.EPA estimated 

that nationwide NOx reductions from implementation of Part 89 would be approximately 

60%. 

The federal government introduced fuel sulfur standards for this type of equipment on 

June 29, 2004 in new federal regulation 40 CFR Part 1039. Part 1039 covers large 

nonroad diesel engines, such as those used in construction, agricultural, and industrial 

equipment, to be phased in between 2008 and 2014. The nonroad diesel rule also reduces 

 the allowable sulfur in nonroad diesel fuel by over 99%. Nonroad diesel fuel currently 

averages about 3,400 ppm sulfur. The rule limits nonroad diesel sulfur content to 500 

ppm in 2006 and 25 ppm in 2010. 

Land-Based Spark-Ignition Engines: The U.S.EPA divided land-based spark-ignition 

engines into three board categories – (1) small engines typically used for lawn and garden 

applications, (2) large engines used in industrial applications, and (3) specialty engines 

used in recreational applications. 
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Small SI Engines: This category is covered in 40 CFR Parts 90. Nonroad spark-ignition 

engines below 19 kW (25 horsepower), which usually run on gasoline, are primarily in 

lawn and garden equipment. The U.S.EPA defines lawn and garden equipment as 

handheld and non-handheld. Examples of applicable lawn and garden equipment include 

lawnmowers, string trimmers, leaf blowers, chain saws, commercial turf equipment, and 

lawn and garden tractors fall within this category, but engines used for marine 

propulsion, recreational vehicles, or hobby applications (such as remote-control 

airplanes) are treated separately. 

Under Phase 1 regulations, new small SI engines have been meeting exhaust engine 

standards for HC, CO, and NOx emissions since 1997. According to the U.S.EPA, these 

Phase 1 standards have resulted in a 32 percent reduction in nationwide HC levels from 

these engines. 

The U.S.EPA adopted Phase 2 standards for small SI engines in two separate 

rulemakings. The U.S.EPA adopted new exhaust standards for non-handheld lawn and 

garden equipment in March 1999 that were phased in between 2001 and 2007. The 

U.S.EPA adopted new exhaust standards for handheld lawn and garden equipment (such 

as trimmers, leaf blowers and chainsaws) in April 2000 that were phased in between 2002 

and 2007. 

Standards requiring control of evaporative emissions do not yet apply to Small SI 

engines. 

Large SI Engines: This category is covered in 40 CFR Part 1048. Nonroad SI engines 

above 19 kW (25 hp), which are usually car and truck engines installed in industrial 

equipment, are used in many different applications, including forklifts, airport service 

equipment, generators, compressors, welders, aerial lifts, and ice-grooming machines. 

These engines – which may operate on liquefied petroleum gas, gasoline, or natural gas – 

currently contribute about 2 percent of NOx emissions, and 3 percent of HC and CO 

emissions from mobile sources nationwide in 2003 according to EPA. 

EPA has adopted emission standards for Large SI engines that take effect for new engines 

starting in 2004. Manufacturers will rely on emission-control technologies from 

automotive engines, including three-way catalysts and electronic fueling systems, to meet 

these emissions standards. Starting in 2007, manufacturers have need to use optimized 

engines, including new diagnostic systems, to meet more stringent standards calling for a 

90-percent reduction in NOx, HC, and CO emissions. 

Recreational Vehicles: This category is covered in 40 CFR Part 1051. This category 

includes off-highway motorcycles, all-terrain vehicles, and snowmobiles that operate on 

gasoline. According to EPA, this category may also include some motorized scooters, 

mini-bikes, and mopeds. EPA noted that in 2003 this category contributed about 5 

percent of HC emissions and 2 percent of CO emissions from mobile sources nationwide. 

In November 2002, EPA adopted emission standards for new recreational vehicles that 

was phased in starting in 2006. Those standards were estimated to reduce HC emissions 

from these vehicles by 67 percent and CO emissions by 28 percent nationwide. 
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Gasoline Marine Engines (40 CFR Part 91): The U.S.EPA promulgated emission control 

requirements for gasoline marine engines under Part 91. Examples of gasoline marine 

engines includes gasoline outboards, personal watercraft engines and jet boat engines. 

The effective date for the introduction of such exhaust standards was July 1996 and Part 

91 imposes increasingly stringent standards for new engines for model years beginning in 

1998 through 2006. The U.S.EPA projected a nationwide reduction of 75 percent for 

hydrocarbons over the course of 1996 through 1998. 

Diesel Marine Engines (40 CFR Part 94): The U.S.EPA promulgated emission control 

requirements for diesel marine engines under Part 94. Examples of diesel engines 

includes recreational yachts, fishing boats, tug and towboats, dredgers, and coastal and 

ocean-going vessels. Internationally, emissions from marine diesel engines are controlled 

by Annex VI of the International Convention for the Prevention of Pollution from Ships 

(known as the MARPOL convention). The NOx limits, contained in Regulation 13 of 

Annex VI apply to marine diesel engines rated above 130 kW and are similar in 

stringency to the first tier of emission standards adopted for land-based nonroad diesel 

engines. The Regulation 13 standards are also triggered if an engine is substantially 

modified on or after January 1, 2000. The international standards went into effect in 

2005. 

In 2003, EPA adopted requirements to make the Regulation 13 standards enforceable 

beginning January 2004 for engines above 2.5 liters per cylinder installed on vessels 

flagged in the U.S. EPA has also adopted more stringent national standards for certain 

categories of marine diesel engines installed on vessels flagged in the U.S. The levels of 

the standards and their application dates vary depending on engine size. (Note that EPA 

has not finalized Tier 2 standards for engines greater than or equal to 30.0 liters per 

cylinder but is required to do so on or before December 17, 2009, in accordance with 

federal regulations.) 

40 CFR Part 87: Aircraft Engine Standards: Section 231 of the CAA directs the EPA 

Administrator to issue proposed emission standards applicable to the emissions of any 

air pollutant from any class or classes of aircraft or aircraft engines which in his 

judgment causes, or contributes to, air pollution which may reasonably endanger public 

health or welfare. Under this authority EPA has conducted several rulemakings 

establishing emission standards and related requirements for several classes (commercial 

and general aviation engines) of aircraft and aircraft engines. 

3⁄4 1973: EPA promulgated emission regulations for vented fuel, smoke and exhaust 

emissions (HC, NOx, and CO) [see 38 FR 19088, July 17, 1973] 

3⁄4 1976: EPA promulgated standards for supersonic aircraft engines. [see 41 FR 34722, 

August 16, 1976] 

3⁄4 1980: EPA rescinded all gaseous emission requirements for piston engines and 

auxiliary power units. [see 45 FR 1419, January 7, 1980] 

3⁄4 1981: The International Civil Aviation Organization (ICAO) issued its first 

international standards and recommended practices covering aircraft engine 

emissions. These provisions applied to many of the same classes of engines to which 

the U.S. standards in force at the time applied. 
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3⁄4 1982: EPA withdrew HC, CO, NOx, and smoke emission standards for various 

aircraft (and engine) categories. 

3⁄4 1993: ICAO issued an amendment to existing NOx emission standards and test 

procedures for aircraft engine emissions. These standards took effect in the year 1996 

through 2000 and represented a 20 percent reduction over the 1981 ICAO NOx 

standards. 

3⁄4 1997: EPA adopted the ICAO's 1993 amendments, ICAO's existing NOx and CO 

emission standards issued in 1981 and other technical amendments to further align 

EPA and ICAO requirements. These standards and test procedures apply to 

commercial aircraft engines; no general aviation or military engines are covered in 

this rule. 

EPA noted that in 1997, aircraft engines contributed about 2 percent of the total U.S. 

mobile source NOx and CO emissions. In addition, EPA noted that in some U.S. airport 

areas, aircraft can contribute up to 4 percent of mobile source NOx emissions. Emissions 

of NOx from aircraft are increasing (due in part to an increase in LTOs) and this growth 

is occurring at a time when other significant mobile and stationary sources are drastically 

reducing emissions, thereby accentuating the growth in aircraft emissions. 

Under the authority of Section 231 of the CAA, EPA adopted standards equivalent to 

ICAO's February 1999 NOx standards and March 1997 test procedure amendments [see

70 FR 69664-69687]. These standards only apply to certain commercial aircraft engines 

whose date of manufacture of the first individual production model was after December 

31, 2003. The effective date of this rule is December 19, 2005. 

40 CFR Part 92: Railroad Engine Standards: Locomotives contribute about 7 percent of 

NOx emissions and 5 percent of diesel PM emissions from mobile sources nationwide 

according to the U.S.EPA in 2003. These engines are usually larger than any land-based 

nonroad diesel engines in displacement volume and total power and may last for 40 years 

or longer. The U.S.EPA adopted three separate sets of emission standards, with the 

standards taking effect depending on the date a locomotive is first manufactured. 

Tier 0 Standards: These first set of standards apply to locomotives and locomotive 

engines originally manufactured from 1973 through 2001 any time they are manufactured 

or remanufactured. Locomotives are generally remanufactured five to ten times during 

their total service lives of 40 years or more according to the U.S. EPA in 2003. 

Tier 1 Standards: This set of standards apply to locomotives and locomotive engines 

originally manufactured from 2002 through 2004. These locomotives and locomotive 

engines must meet the Tier 1 standards at the time of original manufacture and at each 

subsequent remanufacture. 

Tier 2 Standards: This set of standards apply to locomotives and locomotive engines 

originally manufactured in 2005 and later. These locomotives and locomotive engines 

must meet the Tier 2 standards at the time of original manufacture and at each subsequent 

remanufacture. 
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Tier 3 Standards: This set of standards apply to locomotives and locomotive engines 

originally manufactured in 2009 and later. These locomotives and locomotive engines 

must meet the Tier 3 standards at the time of original manufacture and at each subsequent 

remanufacture. 

Tier 4 Standards: This set of standards apply to locomotives and locomotive engines 

originally manufactured in 2015 and later. These locomotives and locomotive engines 

must meet the Tier 4 standards at the time of original manufacture and at each subsequent 

remanufacture. 

5.4 Action Plan for Reducing Emissions with Voluntary Control 

Measures 

Georgia EPD recognizes that every sector, from the public through all levels of 

government, business, and industry, must reduce emissions in order to bring the metro 

Atlanta area into attainment with the 8-hour ozone standard. The Atlanta 1-hour ozone 

plans contained aggressive regulatory components that have resulted in substantial 

reductions in ozone precursors, but EPD recognizes that regulations alone cannot bring 

about all the reductions that are necessary to reach attainment. Stationary sources are 

already heavily controlled, and although reductions from additional stationary source 

controls, to be installed in accordance with Georgia Rule 391-3-1-.02(2)(sss),2

 will 

reduce future ozone formation, those controls won't be in place before the attainment 

date. Similarly, more stringent tail-pipe standards for new vehicles will not produce 

emissions reductions until the old engines are replaced with cleaner new engines. 

EPD, through its participation in The Clean Air Campaign, actively promotes emission 

reductions from voluntary programs, and also supports the development and 

implementation of innovative programs that partner with local jurisdictions, businesses 

and private citizens to implement emission-reducing behaviors at the local level. 

Inclusion of the following programs in the control measures portion of this attainment 

plan is not intended to create an enforceable commitment by EPD to implement the 

programs or to achieve any specific emission reductions projected as a result of 

implementation of the programs, and EPD does not make any such commitment. In 

addition, EPD does not rely on any emission reductions projected as a result of 

implementation of these programs to demonstrate attainment. While the emission 

reduction from these programs is potentially substantial, leading to significant regional 

air quality benefits, actual air quality benefits are uncertain and the reductions are not 

federally enforceable. Consequently, projected emission reductions from these programs 

are not included in the emission inventory, the attainment modeling, the reasonable 

further progress calculation, or any other area of the SIP where specific projected 

emission reductions are identified. 

2

 see Section 8.12.3 
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5.4.1 Emission Reductions from Transportation Measures 

Substantial funding commitments have come from State and local agencies and private 

employers for promotion of strategies to reduce on-road mobile emissions. Examples of 

these measures include idling reduction; ridesharing; teleworking; transit use; vehicle 

replacement and retrofit measures; and bicycle and pedestrian programs. 

These programs are working to reduce emissions from mobile sources, and they play an 

important role in the transportation sector's contribution to cleaner air. EPD is not 

including their effects in this SIP, but any emission reductions projected as a result of 

implementing these directionally correct programs could be used outside of the SIP for 

transportation planning purposes if needed. 

The following are descriptions of selected emission reduction strategies and organizations 

that promote these strategies in Georgia. 

The Clean Air Campaign

When air quality in Georgia becomes unhealthy, elevated pollution levels pose significant 

health and economic impacts to its citizens. Traffic congestion is a major problem in the 

Atlanta region, where individuals waste hundreds of hours every year stuck in traffic on 

congested roadways. The traffic congestion contributes to air quality problems; 

numerous studies have demonstrated that reducing ground level emissions of NOx and 

VOC from mobile sources such as cars and trucks is advantageous in addressing smog 

problems. 

Reduced commuter road miles decrease air polluting vehicle emissions, gasoline 

consumption, traffic congestion, and highway maintenance costs for Georgia's citizens. 

With 4.2 million people in the metro Atlanta region today, and another 2.5 million 

expected in the next 25 years, Georgia must take action now to address these traffic and 

air quality challenges. 

The Clean Air Campaign (CAC) is a 501(c)3 nonprofit corporation that works 

collaboratively with a number of organizations as part of a regional, and increasingly 

statewide, public-private partnership. This partnership uses transportation demand 

management activities – such as carpool and transit programs – to reduce traffic 

congestion and improve air quality. The mission of the Clean Air Campaign is to 

motivate Georgians to take action to improve air quality and reduce traffic congestion. 

The Clean Air Campaign motivates individuals to change their commuting habits and live 

a clean air lifestyle; it also partners with employers to promote clean commuting in the 

workplace and works with schools to empower children to get involved in cleaning the 

air. Some of the recent results of the efforts of the Clean Air Campaign are noted in 

Table 5.10. 
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Transportation Demand Management (TDM) in Atlanta

The rapid population increase in the Atlanta region in recent years has caused community 

leaders to address concerns over increased traffic congestion and poor air quality. As a 

result, Atlanta's Transportation Demand Management (TDM) community continues to 

expand its efforts in three major program areas: media campaigns, employer and 

individual outreach services, and regional supporting programs and services. In addition 

to The Clean Air Campaign, TDM practitioners and Transportation Management 

Associations (TMAs) in the Atlanta region aim to change individual and employer 

attitudes and behaviors about the voluntary use of alternative forms of transportation in 

an effort to reduce traffic congestion and improve air quality. The participating 

organizations include but are not limited to the following: 

3⁄4 Atlanta Regional Commission's 187RIDEFIND program 

3⁄4 Buckhead Area TMA (BATMA) 

3⁄4 Central Atlanta Progress/Downtown Atlanta TMA 

3⁄4 The Clean Air Campaign 

3⁄4 Clifton Corridor TMA (CCTMA) 

3⁄4 CobbRides TMA (CobbRides) 

3⁄4 Commuter Club (formerly Cumberland Transportation Network TMA) 

3⁄4 Hartsfield Area TMA (HATMA) 

3⁄4 Midtown Transportation Solutions TMA (MTS) 

3⁄4 Perimeter Transportation Coalition TMA (PTC) 

Other supporting partners and programs include but are not limited to the following: 

Metropolitan Atlanta Rapid Transit Authority (MARTA), Douglas County Rideshare, 

Georgia Regional Transportation Authority (GRTA), GDOT, EPD, Georgia 

Environmental Facilities Authority, and MetroVanpool. 
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Table 5-13: Clean Air Campaign in Metro Atlanta Region 

Employer Services 

• Provides one-on-one assistance to 500 

employers and property management 

companies. In 2006, these employers 

started 870 new programs, such as 

teleworking and carpooling. 

• Outreach team provides approximately 

30,000 hours of consulting time to 

employers across the region 

• Partners represent more than 300,000 

employees. 

Incentives for Commuters & Employers 

• In 2006, 21,000 commuters participated 

in Commuter Rewards, an innovative 

regional incentive program. 

• Cash for Commuters, which rewards new 

users of commute alternatives, has 

eliminated 62 million miles since its 2002 

launch. Sixty-four percent of 

participants are still clean commuting

nine months to one year after the incentive 

ends. 

• The 2006 Metro Atlanta Walk There! 

Challenge succeeded in getting 6,100 

participants to walk more and drive less. 

• Almost 3,500 new teleworkers have 

started working from home because of the 

Telework Leadership Initiative. Fifty 

employers have started or greatly expanded 

telework programs with the help of this 

initiative. 

Regionally, 72 new vanpools hit the road in 

2006 using the Vanpool Incentive Program, 

reducing 4.4 million vehicle miles. Overall, 

the region's 349 vanpools reduced 40 million 

miles from our roadways.

Public Education & Awareness 

• Radio spots supporting a call to "Give 

Your Car a Day Off," espousing the 

financial and quality of life benefits to 

commuters. 

• Radio spots featuring representations of 

UPS, Cox Enterprises, GE Energy and the 

State of Georgia tout the business benefits 

of commute alternative programs. 

• Public relations raised awareness and 

program participation through more than 

475 news stories in 2006, including 

national exposure for innovative programs 

by the Associated Press, The New York 

Times, Good Morning America, and XM 

Radio. 

• In 2006, The Clean Air Campaign Web site 

averaged 6,500 unique visitors each month.

Better Air Schools 

• Eighteen elementary and middle schools in 

metro Atlanta participate as Better Air 

Schools, helping reach more than 17,000 

children and 2,000 staff members.

• Ride There! helped schools realize 

increases in bus ridership of six to 11 

percent. 

• BAIR, the Better Air Bear, performs at 

more than 70 schools, events and 

organizations each year, teaching children 

about air quality and its solutions. 

• In 2006, The Clean Air Campaign's air 

quality lesson plans were downloaded 

more than 25,000 times. 

Pedestrian Walkways and Bikeways Projects

A number of communities are creating walkways and bikeways in order to provide safe 

pathways for pedestrians and bicyclists to move about busy traffic areas. These types of 

projects provide safe alternatives to driving in the city. For example, the Atlanta 

Regional Commission has produced bicycle suitability maps for every county in the 

Atlanta region as well as the City of Atlanta to assist the cycling community in 

determining the safest and most logical paths. The maps identify existing on –road 

bicycle facilities, off-road paths, transit stations, bus routes, and various points of interest. 
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Traffic Signal System Retiming

A goal of traffic signal system retiming is to improve the flow of traffic through a 

corridor or system and thereby reduce emissions of NOx and VOC. There are numerous 

studies underway by the various metro Atlanta Transportation Management Associations 

to analyze existing and proposed intersections to determine the need for traffic signal 

installation or upgrades to existing signals as well upgrades to existing traffic signalsinterconnect-signal coordination plans. 

High Occupancy Vehicle (HOV) Lanes

High Occupancy Vehicle (HOV) lanes were introduced to metro Atlanta on December 

14, 1994, along an 18-mile section of I-20, east of I-75/85. An additional 60 lane miles 

opened on I-75 and I-85 inside I-285 in 1996. They are an integral part of the Georgia 

NAVIGATOR system, designed to help reduce air pollution, improve traffic congestion 

and ensure a substantial time savings for commuters who rideshare (two or more 

occupants per vehicle). 

HOV lanes, identified by diamond-shaped pavement markings and overhead signs, are 

located on I-20, I-75, and I-85. They are designated only for vehicles carrying two or 

more occupants, certified alternative fuel vehicles, motorcycles and emergency vehicles. 

HOV lanes have been extended in the metro Atlanta region since January 1, 2003, as 

follows: 

3⁄4 Approximately 11.8 miles on I-85 northbound and southbound from ChambleeTucker Road to State Route 316. As part of this project, the Georgia NAVIGATOR

System has also been expanded along I-85 to State Route 316 with the installation of 

cameras, fiber optic cable and changeable message signs. 

Income Tax Credits for Teleworking

In January 2008 the Georgia Department of Revenue announced that 135 employers have 

been approved to take tax credits in 2008 for creating and expanding telework programs. 

These credits will provide in part fewer cars on Atlanta’s roads during the work week. 

Georgia Code O.C.G.A. §48-7-29.11 provides authority for this program and Georgia is 

the first in the nation to offer a tax credit of this kind [Atlanta Journal Constitution 

February 26, 2008]. In 2008, the Georgia General Assembly extended this tax credit 

through 2011. 

5.4.2 Retrofits/Use of Alternative Fuels 

Georgia Adopt-A-School Bus Program
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Georgia EPD has initiated a school bus retrofit program, also referred to as the Adopt-ASchool Bus Program. It focuses on retrofitting school buses with diesel oxidation 

catalysts, diesel particulate filters, catalyzed wire-mesh filters, and crank case filters and 

using cleaner fuels such as ultra low sulfur diesel. Georgia EPD has established 

agreements with seven school systems, which has resulted in 699 school buses retrofitted. 

In addition, another 360 school bus retrofits have been completed by school systems 

seeking funding directly. EPA and CMAQ grants and supplemental environmental 

projects have provided the bulk of the funding for these projects. At this time, additional 

CMAQ funds are available for retrofitting school buses and other diesel vehicles and 

equipment. The CMAQ funds require a 20% match from the school systems or other 

project partners. The Georgia Regional Transportation Authority has stepped up as a 

project partner and is contributing $40,000 to leverage up to $160,000 in federal CMAQ 

funds for the Adopt-A-School Bus Program. 

Georgia Diesel Working Group

The Georgia Diesel Working Group, with members from EPD, U.S. EPA, and public and 

private entities throughout Georgia, formed in 2004 to develop mechanisms and solutions 

to address and reduce the contribution of diesel engines to Georgia's air quality problems. 

Ultra-Low Sulfur Diesel Fuel (ULSD)

The federal ULSD fuel program, when fully implemented and combined with heavy-duty 

diesel engine controls phased in through 2010, is expected to reduce PM and NOx 

emissions by 90% and 95%, respectively. Georgia EPD established a statewide contract 

in 2005 through which state and local agencies could purchase ULSD over a year sooner 

than it would otherwise be available under the federal program. Several agencies are 

utilizing this contract, including GRTA's Xpress regional express commuter coach 

system. 

Low Emission Vehicle Certification Program

The Low Emissions Vehicle Certification Program allows for tax credits for the purchase 

of dedicated alternative fuel low emission vehicles, for electric vehicle chargers 

purchased by businesses, for the purchase of zero emission vehicles, and for the 

conversion of conventional fueled vehicles to low emission alternative fueled vehicles. 

Georgia Diesel Emissions Reduction Technology Tax Credit

The State of Georgia offers a 10% tax credit diesel particulate emissions reduction 

equipment, including equipment for alternative power during idling. The tax credit 

applies to 10% of the total cost of equipment and installation costs (Georgia Code 48-7-

40.16). 

Congestion Mitigation and Air Quality Improvement Program (CMAQ) Retrofit Projects

A total of $2.5 million (2005$) in federal CMAQ funds were programmed for fiscal years 

2005 and 2006 in the Atlanta Transportation Improvement Program for retrofitting school 

buses in the area with emissions control devices. Another $4.7 million were programmed 

for the same period to help offset the incremental costs of ultra-low sulfur diesel fuel 

which must be used for some diesel retrofit technologies. Georgia EPD is the sponsor of 

these two projects. 
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Truck Stop Electrification (TSE)

Historically truck drivers idle their engines about eight hours a day, or as much as 1,800 

hours annually. Under federal law, truckers must rest 8 hours for every 10 hours of 

driving. During this rest period, truck drivers often idle their engines to operate air 

conditioning or heat in their sleeper cabs, or on-board appliances such as television or 

microwave. Idling also keeps engines and fuel warm in cold weather. 

Truck Stop Electrification (TSE) is a technology solution with two ways to reduce 

extended truck idling: on-board and off-board. On-board TSE combines battery storage 

on the truck with recharging at truck stops to power truck electric appliances. These 

applications include electric heaters and air conditioning units. Off-board technologies 

provide heating and air conditioning infrastructure at truck stops. An overhead unit 

supplies cool or warm air to the truck cab by a hose connection. In addition to basic 

heating and cooling services, TSE users can purchase Internet access, movies, and 

satellite programming. Both on-board and off-board technologies allow the trucks to turn 

off their engines, thus saving fuel and reducing air pollution (emissions of both NOx and 

VOC). TSE is taking place in the following counties: 

• Bartow County: 72 spaces at a truck stop in Cartersville were converted with IdleAire 

technology. 

• Butts County: 63 spaces at a truck stop in Jackson were converted with IdleAire 

technology 

• Coweta County: 51 spaces at a truck stop in Newnan were converted with IdleAire 

technology. 

• Fulton County: 96 spaces at a truck stop in Atlanta were converted with IdleAire 

technology. 

5.4.3 Energy Demand Reduction 

Georgia relies on a variety of energy sources. Petroleum products provide energy for 

transportation; natural gas, coal and other electricity fuels are used for heating, cooling, 

lighting and industrial production. This energy use affects the quality of life of all 

Georgians, creating jobs, providing mobility and sustaining the state’s prosperity. 

However, by-products of energy use and high energy costs can erode this quality of life. 

Without reducing demand as the population and economic activity increase, Georgians 

may face more price volatility, supply constraints, security threats and health and 

environmental stress. The Governor’s Energy Policy Council addressed the topic of 

energy demand as part of their State Energy Strategy (December 14, 2006). As part of 

this Strategy, the Council explored opportunities to treat energy efficiency as a 

“resource” equal in value to new energy supplies. The Council noted “Energy efficiency 

is one of the most cost effective and rapidly deployable resources available to Georgians, 

and has the added benefit of reducing the health and environmental impact of energy 

consumption. 

Policies and strategies to sustain Georgia’s quality of life and productivity while reducing 

the state’s energy consumption through conservation and efficiency are documented as 
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part of Chapter 3 of the Strategy. Chapter 3 of the Strategy is organized around six 

policy objectives, which are programs or policies intended to move Georgia toward 

affordable, reliable and environmentally responsible energy. Each policy objective is 

followed by associated implementation strategies, which are designed to achieve or 

implement the policy. The following table highlights the Council’s recommendations 

regarding energy demand reduction. 

Sector Policy Objective Implementation Strategy 

Reduce Energy Demand in 

Transportation 

Increase the Use of 

Technologies that Make the 

Vehicle-Based 

Transportation System 

More Fuel Efficient 

3.1: Create incentives to 

increase the adoption of 

efficient vehicles and 

vehicle technologies. 

3.2: Establish purchasing 

criteria for the State to 

increase the use of efficient 

vehicles in its fleet. 

3.3: Use and support idle 

reduction technologies. 

3.4: Increase the use of 

“smart” traffic control 

technologies and practices. 

Support Transportation 

Demand Management 

Efforts 

3.5: Maximize the use of 

telecommunication 

technology and egovernment to provide 

government services to the 

public. 

3.6: Encourage continued 

or expanded funding for 

proven TDM programs. 

Increase the Availability of 

and Access to Public 

Transportation and Transit 

Options 

3.7: Continued support and 

funding for public transit 

systems. 

Reduce Energy Demand for 

Electricity and Natural Gas 

Support the Use of Efficient 

Building Technologies and 

Practices 

3.8: Create incentives to 

increase the adoption of 

efficient building 

technologies and practices. 

3.9: Establish energy 

reduction goals for public 

facilities. 
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Sector Policy Objective Implementation Strategy 

3.10: Encourage the use of 

energy savings performance 

contracting to finance 

energy efficiency projects. 

3.11: Develop more 

effective building energy 

code enforcement 

strategies. 

Increase the Use of 

Efficient Appliances and 

Equipment 

3.12: Continue incentives 

to increase the adoption of 

efficient appliances and 

products. 

3.13: Establish minimum 

energy performance criteria 

for all appliance and 

equipment purchases by the 

State. 

Support the Increased 

Involvement of Electric and 

Natural Gas Utilities in 

Promoting and 

Implementing Energy 

Efficiency 

3.14: Encourage 

achievement of a voluntary 

energy efficiency target for 

electric and natural gas 

utilities. 

3.15: Consider alternative 

utility regulation strategies 

that allow utilities to 

recover investments in 

energy efficiency. 

5.4.4 Activities at Hartsfield-Jackson Atlanta International Airport 

The Hartsfield-Jackson Atlanta International Airport (HJAIA) is one of the world's 

busiest airports, and a source of emissions of ozone precursors in the Atlanta metro area. 

HJAIA has taken numerous steps to minimize emissions of ozone precursors in light of 

the fact that the activity generating the emissions is not expected to decrease. Georgia 

EPD does not have authority to impose equipment-specific emission standards or 

operational standards due to federal preemption law. Therefore, minimization of 

emissions at HJAIA must take place on a voluntary basis as well as be an inherent portion 

of future HJAIA facility management plans. 
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Sources of emissions of ozone precursors include aircraft, auxiliary power units (APUs), 

ground support equipment (GSE), passenger-related motor vehicles, construction, 

deicing, aircraft refueling, engine testing, fire training, boilers, generators, fuel storage 

tanks, and emergency generators. 

HJAIA has undertaken the following projects to either reduce negative environmental 

effects associated with operating the airport or to enhance customer service and provide 

an environmental benefit. Further discussion of HJAIA efforts to minimize air emissions 

is located in Appendix Q. 

• Reduced Traffic to and from Airport: This category of projects includes: MARTA 

rail access to airport; Delta Air Line Ticket Counters in MARTA terminal; the City of 

Atlanta Department of Aviation provides real time airport status and parking lot 

availability via radio station and web site; local and intercity bus service; and 

activities coordinated by the Hartsfield Airport Transportation Management 

Association. 

• Reduced Idling Emissions: This category of projects includes: Expansion of 

Concourse E to eliminate (or reduce) the need for remote parking of planes; taxiway 

and intersection upgrades; expediting of critical airfield construction; use of super 

tugs; upgrading of some portion of the ground service equipment population from 

traditional diesel engine to electric engine; and equipping a majority of the gates with 

fueling carts. 

• Miscellaneous: This category of projects includes: Use of light colors on surfaces of 

new construction to reduce heat island effects; and commissioning of a compressed 

natural gas fueling station. 

The following projects are either under construction or are anticipated to be under 

construction in the near future. 

• Reduced Traffic to and from Airport: This category of future projects includes the 

Consolidated Rental Car Facility equipped with automatic people mover. 

• Reducing Idling Emissions: This category of future projects includes: Taxiway, 

runway and intersection upgrades; parking pay-on-foot option; use of two departure 

headings; optimize fleet mixes; expand the number of ramp charging stations for 

electric ground service equipment; use of single engine taxi; use of automated billing 

system for various users of the Ground Transportation Center (GTC) that use 

automatic vehicle identification to track the number of times the GTC is accessed as 

well as the amount of time spent at the GTC; and the addition of more gates to 

Concourse E to reduce the occurrence of remote parking of planes. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

130 

6.0 ATTAINMENT DEMONSTRATION 

This section summarizes the procedures that were used to demonstrate attainment of the 

8-hour ozone National Ambient Air Quality Standard (NAAQS) in this State 

Implementation Plan (SIP) package. As described in the US Environmental Protection 

Agency's (USEPA's) September 2006 draft final Guidance On The Use Of Models And 

Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, 

and Regional Haze ("Attainment Guidance"), an attainment demonstration consists of (a) 

analyses which estimate whether selected emissions reductions will result in ambient 

concentrations that meet the NAAQS, and (b) an identified set of control measures which 

will result in the required emissions reductions. The necessary emission reductions for 

both of these attainment demonstration components may be determined by relying on 

results obtained with air quality models. 

Section 3.0 of the Attainment Guidance recommends applying both a modeled attainment 

test and a subsequent screening test to the air quality modeling results to determine if the 

8-hour ozone NAAQS will be met. Additional technical or corroboratory analyses may 

also be used as part of a "weight of evidence" determination to supplement the modeled 

attainment test and to further support a demonstration of attainment of the NAAQS. 

6.1 Modeled Attainment Test 

The modeled attainment test is the practice of using an air quality model to simulate 

baseline (i.e., current) and future air quality. For the 8-hour ozone NAAQS, the baseline 

and future model estimates are used in a "relative" rather than "absolute" sense. 

Specifically, the ratio of the air quality model's future to baseline predictions is calculated 

at each ozone monitoring site. These monitoring site-specific ratios are called relative 

response factors (RRF). Future ozone design values (DVF) are then estimated at each 

monitor by multiplying the monitor-specific baseline ozone design value (DVB) by the 

modeled relative response factor for each monitor. If the resulting predicted site-specific 

DVFs are < 82 parts per billion (ppb), a clear demonstration of predicted attainment is 

shown. If the predicted DVFs is > 82 ppb and < 87 ppb, then a weight of evidence 

(WOE) demonstration must be submitted that supports a demonstration of attainment. 

For DVFs > 87 ppb, the Attainment Guidance states that more qualitative results are less 

likely to support a conclusion differing from the outcome of the modeled attainment test. 

Equation 4-1 presents the modeled attainment test, applied at monitoring site "x" as 

described in Section 4.0 of the Attainment Guidance. 

 (DVF) = (RRF) x (DVB) Equation 6-1 

Where (DVB) = the baseline design value monitored at site "x," ppb 

= the average (of the three) design value periods which include the 

baseline inventory year (i.e. the average of the 2000-2002, 2001-2003, 

and 2002-2004 design value periods for the 2002 baseline inventory 

year). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

131 

 (RRF) = the ratio of the future 8-hr daily maximum concentration predicted 

"nearby" a monitor (averaged over each day of the episode) to the 

current 8-hr daily maximum concentration predicted "nearby" the 

monitor (averaged over each day of the episode). 

 (DVF) = the estimated future design value, ppb. 

The Attainment Guidance recommends considering an array of cells "nearby" a monitor 

rather than focusing on the individual cell containing the monitor, in order to allow for 

variations in the model performance where the peak ozone may not occur in the grid cell 

that contains the monitor but rather nearby the monitor. Since the attainment 

demonstration modeling was performed using a 12-kilometer grid resolution, the size of 

the array for "nearby" cells was 3x3. According to the recommended procedure, the 

maximum value within the 3x3 matrix is used for RRF calculations, for both the future 

and baseline cases, even if these occur in different cells. 

Section 14.1.1 of USEPA's Attainment Guidance outlines the process for determining 

which days are used in the RRF calculation. The day selection process starts by 

identifying all the days in the baseline modeling that has a modeled daily maximum 8-

hour average ozone equal to or greater than 85 ppb. If there are 10 or more days greater 

than 85 ppb, then 85 ppb is used as the cutoff with those days used in the RRF 

calculation. If there are fewer than 10 days with a modeled daily maximum 8-hour 

average ozone equal to or greater than 85 ppb, then the threshold is reduced by 1 ppb 

until there are at least 10 days identified for use. If there are fewer than 10 days with a 

modeled daily maximum 8-hour average ozone equal to greater than 70 ppb, then all days 

at 70 ppb and higher are used in the RRF calculation and consideration of modeling 

another episode should be explored. 

The DVB, for purposes of the modeled attainment test, is defined in the Attainment 

Guidance by one of four methods: 

1. The design value period (i.e. the average 4th highest value for the 3-yr period 

used to designate an area "nonattainment," here the period from 2001 to 2003). 

2. The average 4th highest value for the 3-yr period straddling the baseline inventory 

year (e.g., the 2001-2003 design value period for the 2002 baseline inventory 

year). 

3. The highest of the three design value periods which include the baseline inventory 

year (e.g., the 2000-2002, 2001-2003, 2002-2004 design value periods for a 2002 

baseline inventory year). 

4. The average of the three design value periods which straddle the baseline 

inventory year (e.g., the average of the 2000-2002, 2001-2003, and 2002-2004 

design value periods for a 2002 baseline inventory year). 

The U.S.EPA recommends the fourth method (average of the three design value periods 

straddling the baseline year), which is the method presented in this section. Attainment 

test results for all monitors within the Atlanta nonattainment area are shown in Table 6-1. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

132 

The bold italicized DVFs are values that fall within the range where additional WOE is 

needed to demonstrate attainment. Eight out of the eleven monitors in the Atlanta 

nonattainment area have predicted DVFs that fall below 82 ppb, and the remaining three 

monitors (Confederate Avenue, Tucker, and South-DeKalb) fall within the WOE range 

(82 to 87 ppb), with Confederate Avenue being the only site with a DVF above 85 ppb. 

Table 6-1: Atlanta attainment test results for 2009, using the maximum value in the 

3x3 array surrounding each site 

Site name AIRS ID DVB 

(ppb) 

Number 

of Days 

used in 

RRF 

Ozone 

Threshold

(ppb) 

RRF DVF 

(ppb) 

Confederate Ave. 13-121-0055 94.6 21 85 0.913 86 

McDonough 13-151-0002 92.1 23 85 0.872 80 

Douglasville 13-097-0004 91.6 33 85 0.875 80 

Kennesaw 13-067-0003 91.5 25 85 0.891 81 

Tucker 13-089-3001 91.4 22 85 0.905 82 

Conyers 13-247-0001 91.2 19 85 0.872 79 

South-DeKalb 13-089-0002 90.2 21 85 0.913 82 

Newnan 13-077-0002 88.8 21 85 0.874 77 

Lawrenceville 13-135-0002 88.3 17 85 0.897 79 

Yorkville 13-223-0003 88.2 25 85 0.858 75 

Fayetteville 13-113-0001 85.5 28 85 0.886 75 

6.2 Weight of Evidence 

The Attainment Guidance recommends the use of the predicted or modeled 8-hour daily 

maximum concentration within the 3x3 matrix for all relevant days used in the RRF 

calculations, for both the future and baseline cases, even if these occur in different cells. 

The guidance also recommends the use of the average of the three design value periods 

which straddle the baseline inventory year (e.g., the average of the 2000-2002, 2001-

2003, and 2002-2004 design value periods for a 2002 baseline inventory year). However, 

EPD believes it is more appropriate to use the grid-cell in which each monitor is located 

instead of the maximum value within the 3x3 matrix. EPD has also looked at the 

resulting DVFs based on the first two methods for defining the DVB listed in the 

Attainment Guidance (the average 4th highest value for the 3-yr period used to designate 

an area "nonattainment" and the average 4th highest value for the 3-yr period straddling 

the baseline inventory year). In both these cases, the DVB will be based on the 2001-

2003 design value period. EPD thinks that the third method listed by EPA (highest of the 

three design value periods which include the baseline inventory year) would be a "worst 

case scenario" and considered too conservative since major NOx emission controls were 

implemented between 2000 and 2002. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

133 

6.2.1 Use of Monitor Grid to Calculate RRFs 

EPD previously commented to EPA (Appendix M) that the use of the maximum value 

within the 3x3 matrix for the RRF calculations might not be the best approach for 

determining the impact of precursor emission reductions on ozone concentrations. EPD 

believes and that analyzing the modeling results for the actual grid-cell where the monitor 

is located would be a better approach. 

The Attainment Guidance describes the use of cells "near" a monitor rather than the cell 

containing the monitor in the modeled attainment test. Although three reasons are listed 

why this is appropriate, EPD feels that the use of the cell containing the monitor is more 

appropriate and will lead to more realistic future DVFs at the monitor locations. EPD 

finds it hard to justify using unmonitored grid cells near the monitor to describe what is 

happening at the monitor. Model performance evaluations (MPE) are only conducted for 

the grid cells containing monitors; therefore, we feel that the model attainment test should 

remain consistent with the MPE and only use these grid cells. In addition, calculating 

RRFs based on nearby cells that change locations between the baseline simulation and 

future simulation (not paired in space) can lead to erroneous and misleading conclusions. 

 

To address any potential issues arising from predicted peak "migration," EPD proposes 

that the cells "near" the monitor undergo the "unmonitored area analysis" described in 

Attainment Guidance. Although these grid cells will not be used in the actual modeled 

attainment test to project future design values, they could still be examined along with the 

other unmonitored areas. 

Uncertainty in the formulation of the model and the model inputs is not a good reason to 

use an array of nearby grid cells instead of the cell containing the monitor. There can be 

very large (and very real) differences in precursor emissions, pollutant 

formation/deposition processes, and resulting pollutant concentrations between 

neighboring grid cells within the array. Arbitrarily taking the maximum value or the 

average value is not an accurate way to characterize the changes occurring at the monitor. 

If the model performance at the grid cell with the monitor is extremely poor on a specific 

day, consideration should be given to removing this day from the RRF calculation. 

The use of nearby grid cells is especially inappropriate in situations where there are major 

emission reductions from large point sources or significant area/mobile sources located 

within the array of nearby cells. For example, if the model simulates the installation of 

SCRs at a large utility located one grid cells to the west of the monitor, the model might 

predict lower future ozone concentrations in the array even when the wind is blowing 

perpendicular or even in the completely opposite direction from the monitor. 

As part of EPD's weight of evidence demonstration, RRFs and DVFs have been 

calculated based on the grid-cell in which each monitor is located (Table 6-2). This 

approach results in DVFs for all sites that are below 85 ppb and only two monitors 

(Confederate Avenue and Tucker) that would fall within the WOE range. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

134 

Table 6-2: Atlanta attainment test results for 2009 using the monitor grid cell value.

Site name AIRS ID DVB 

(ppb) 

Number 

of Days 

used in 

RRF 

Ozone 

Threshold

(ppb) 

RRF DVF 

(ppb) 

Confederate Ave. 13-121-0055 94.6 12 85 0.895 84 

McDonough 13-151-0002 92.1 12 85 0.871 80 

Douglasville 13-097-0004 91.6 22 85 0.873 80 

Kennesaw 13-067-0003 91.5 15 85 0.886 81 

Tucker 13-089-3001 91.4 10 84 0.901 82 

Conyers 13-247-0001 91.2 14 85 0.872 79 

South-DeKalb 13-089-0002 90.2 12 85 0.895 80 

Newnan 13-077-0002 88.8 10 85 0.860 76 

Lawrenceville 13-135-0002 88.3 10 79 0.899 79 

Yorkville 13-223-0003 88.2 12 85 0.859 75 

Fayetteville 13-113-0001 85.5 16 85 0.881 75 

6.2.2 Use of Alternative DVB to Calculate DVF 

EPD has also looked at the resulting DVFs based on the first two methods for defining 

the DVB listed in the Attainment Guidance (the average 4th highest value for the 3-yr 

period used to designate an area "nonattainment" and the average 4th highest value for 

the 3-yr period straddling the baseline inventory year). In both these cases, the DVB will 

be based on the 2001-2003 design value period, resulting in area-maximum DVB of 91.6 

ppb (at Confederate Avenue). As part of EPD's weight of evidence demonstration, DVFs 

have been calculated based on these revised DVB using the maximum value within the 

3x3 matrix and the actual grid-cell containing the monitor for the RRF calculations 

(Tables 6-3 and 6-4). This approach results in DVFs for all sites that are below 85 ppb, 

with the Confederate Avenue's DVF being the only one within WOE range (83 ppb based 

on the "maximum in array" method; 82 ppb based on the "monitor grid cell" method). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

135 

Table 6-3: Atlanta attainment test results for 2009, using a three-year DVB and the 

maximum value in the 3x3 array surrounding each site 

Site name AIRS ID DVB 

(ppb) 

Number 

of Days 

used in 

RRF 

Ozone 

Threshold

(ppb) 

RRF DVF 

(ppb) 

Confederate Ave. 13-121-0055 91.6 21 85 0.913 83 

McDonough 13-151-0002 89.0 23 85 0.872 77 

Douglasville 13-097-0004 91.6 33 85 0.875 80 

Kennesaw 13-067-0003 90.6 25 85 0.891 80 

Tucker 13-089-3001 89.6 22 85 0.905 81 

Conyers 13-247-0001 89.3 19 85 0.872 77 

South-DeKalb 13-089-0002 87.6 21 85 0.913 80 

Newnan 13-077-0002 87.0 21 85 0.874 76 

Lawrenceville 13-135-0002 85.6 17 85 0.897 76 

Yorkville 13-223-0003 89.0 25 85 0.858 76 

Fayetteville 13-113-0001 83.0 28 85 0.886 73 

Table 6-4: Atlanta attainment test results for 2009 using a three-year DVB and the 

monitor grid cell value. 

Site name AIRS ID DVB 

(ppb) 

Number 

of Days 

used in 

RRF 

Ozone 

Threshold

(ppb) 

RRF DVF 

(ppb) 

Confederate Ave. 13-121-0055 91.6 12 85 0.895 82 

McDonough 13-151-0002 89.0 12 85 0.871 77 

Douglasville 13-097-0004 91.6 22 85 0.873 80 

Kennesaw 13-067-0003 90.6 15 85 0.886 80 

Tucker 13-089-3001 89.6 10 84 0.901 80 

Conyers 13-247-0001 89.3 14 85 0.872 77 

South-DeKalb 13-089-0002 87.6 12 85 0.895 78 

Newnan 13-077-0002 87.0 10 85 0.860 74 

Lawrenceville 13-135-0002 85.6 10 79 0.899 77 

Yorkville 13-223-0003 89.0 12 85 0.859 76 

Fayetteville 13-113-0001 83.0 16 85 0.881 73 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

136 

6.3 Local Measures not Modeled 

The metro Atlanta area has a number of groups that are working towards decreasing 

emissions. These measures are voluntary measures that, although may not result in large 

emission reductions, are directionally correct. A few of the known measures that are 

under way in the metro Atlanta area include: The Clean Air Campaign, truck stop 

electrification, traffic signal system retiming, High Occupancy Vehicle (HOV) lanes, 

pedestrian walkways and bikeways projects, idle reduction policies, biodiesel use and 

diesel retrofit projects. Discussions of these measures can be found in Section 5.3. 

6.4 Unmonitored Area Analysis 

The modeled attainment test does not address future air quality at locations where there is 

not an ozone monitor nearby. To guard against the possibility that air quality levels could 

exceed the standard in areas with limited monitoring, Section 3.4 of the Attainment 

Guidance suggest that additional review is "necessary, particularly in nonattainment areas 

where the ozone or PM2.5 monitoring network just meets or minimally exceeds the size of 

the network required to report data to Air Quality System (AQS)." This review is 

intended to ensure that a control strategy leads to reductions in ozone at other locations 

that could have baseline (and future) design values exceeding the NAAQS if a monitor 

was deployed there. The test is called an "unmonitored area analysis" (UAA). The 

purpose of the analysis is to use a combination of model output and ambient data to 

identify areas that might exceed the NAAQS if monitors were located there. 

For UAA, EPD adopted the Modeled Attainment Test Software (MATS) tool that was 

developed by the U.S.EPA to spatially interpolate data, adjust the spatial fields based on 

model output gradients, and multiply the fields by model calculated RRFs for analysis of 

unmonitored areas. The version of MATS that EPD used is 1.1.2 (Build 123) and it can 

be found on EPA's MATS website: 

http://www.epa.gov/scram001/modelingapps_mats.htm

 

Details of EPD's MATS operations are demonstrated in Figure 6-1. It shows the 

operational choices that EPD made for the UAA by capturing computer screens of MATS 

operations. These four steps are mandatory to get DVFs. Of the required input 

parameters needed to run MATS, the number of days used to calculate spatial gradients 

from the modeling outputs is one of the most critical inputs. As shown in Table 6-1, the 

number of days EPD included in the RRF calculation for the Confederate Avenue 

monitor was 21 days. Given that the Confederate Avenue monitor observed high ozone 

concentrations and the CMAQ 12km modeling predicted similar trends, EPD chose to 

use 21 days for the UAA. In addition, EPD used 153 days to analyze "average" ozone 

seasonal gradient of predicted daily maximum 8-hour ozone concentration fields. Input 

and output files used in the application of MATS are located in Appendix V. The results 

of UAA from MATS are shown in Figure 6-2 through Figure 6-4. Circles denote 

monitors and squares represent model grid cells in the CMAQ 12 km modeling domain. 

Red symbols indicate DVF values greater than or equal to 85 ppb. Orange and yellow 

symbols are for DVF of 80-84 ppb and 75-79 ppb, respectively. White symbols depict 

locations where the DVF is less than or equal to 74 ppb. Figure 6-3 and Figure 6-4 

shows details of the MATS outputs around Atlanta areas when 21 days and 153 days 

were used for the UAA. No modeling grid cells showed DVFs greater than 86 ppb when 

21 days were used. If 153 day were used, all modeling cells showed DVFs less than 85 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

137 

ppb. In general, all Georgia modeling grid cells showed predicted DVFs close to or equal 

to those of the nearby monitors. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 6-1: Demonstration of EPD's MATS operation. 

138 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

 

Figure 6-2: Results of MATS when 21 days were used for spatial gradient calculations. 

Circles denote monitors and squares represent model grid cells in the CMAQ 12 km 

modeling domain. Red symbols indicate DVF values greater than or equal to 85 ppb. 

Orange and yellow symbols are for DVF of 80-84 ppb and 75-79 ppb, respectively. 

White symbols depict locations where the DVF is less than or equal to 74 ppb. 

139 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 6-3: Detail visualization of MATS outputs when 21 days were used. 

The first line of labels indicates AIRS ID and the second line of labels are DVF at 

each monitor. Numbers in red colored cells show DVFs. Other color schemes are 

the same as Figure 6-2. 

140 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Figure 6-4: Detail visualization of MATS outputs when 153 days were used. 

The first line of labels indicates AIRS ID and the second line of labels are DVF at each 

monitor. Numbers in red colored cells show DVFs. Other color schemes are the same as 

Figure 6-2. 

6.5 Summary 

The EPD has evaluated future ozone design values using a combination of two methods 

for calculating baseline DVBs (2001-2003 and weighted 2000-2004), and two methods 

for calculating RRFs ("maximum in array" and "monitor grid cell"). A summary of DVFs 

based on these four test configurations is given in Table 6-5. DVFs for ten out of the 

eleven monitors show attainment of the 8-hour ozone NAAQS using the 2000-04 DVB 

and "maximum in array" method. However, all eleven sites show attainment of the 

NAAQS when using the "monitor grid cell" approach or when using the 2001-03 DVB. 

141 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

142 

Table 6-5: Atlanta attainment test results for 2009 

based on four different test configurations. Bold red numbers indicate DVF above 

85 ppb; Bold, underlined green numbers indicate DVF below 85 ppb but within 

weight-of-evidence range; Standard-font green numbers indicate DVF below 82 

ppb. 

Site name AIRS ID 

2000-04 DVB; 

"max in 

array" 

2000-04 DVB; 

"monitor 

grid cell" 

2001-03 DVB; 

"max in 

array" 

2001-03 DVB; 

"monitor 

grid cell" 

Conf. Ave. 13-121-0055 86 84 83 82

McDonough 13-151-0002 80 80 77 77 

Douglasville 13-097-0004 80 80 80 80 

Kennesaw 13-067-0003 81 81 80 80 

Tucker 13-089-3001 82 82 81 80 

Conyers 13-247-0001 79 79 77 77 

S. DeKalb 13-089-0002 82 80 80 78 

Newnan 13-077-0002 77 76 76 74 

Lawrencevill 13-135-0002 79 79 76 77 

Yorkville 13-223-0003 75 75 76 76 

Fayetteville 13-113-0001 75 75 73 73 

6.6 Attainment Conclusion 

The modeled attainment demonstration performed according to EPA guidance results in a 

single monitor in the Atlanta NAA exceeding the 8-hour ozone NAAQS (DVF of 86 ppb 

at the Confederate Avenue monitoring site). However, the weight of evidence analysis 

demonstrated in Section 6.2 provides strong evidence that the Atlanta 8-Hour Ozone 

NAA will demonstrate attainment of the ozone NAAQS by 2009. The attainment 

demonstration with the weight of evidence analysis is effective since the unmonitored 

area analysis showed EPD's modeling showed no modeling grid greater than 86 ppb. 

Additionally, the additional emission control or reduction measures identified in Section 

5.3 as well as those contingency measures that will be implemented, regardless of 

attainment status, will provide additional emission reductions beyond those quantified 

and modeled for this attainment demonstration. Therefore Georgia EPD concludes that 

this document provides an adequate demonstration of compliance with the 8-Hour Ozone 

NAAQS for the Atlanta 8-Hour Ozone NAA by the year 2009. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

143 

7.0 SENSITIVITY OF OZONE IN ATLANTA TO NOx AND 

VOC EMISSIONS 

EPD performed an analysis of the sensitivity of ozone concentrations in the Atlanta 

nonattainment area to reductions in emissions of both nitrogen oxides (NOx) and volatile 

organic compounds (VOCs). The analysis was based off of the Visibility Improvement 

State and Tribal Association of the Southeast (VISTAS) modeling, using the emissions 

inventories for both 2002 and 2009, and CMAQ version 4.5 with the CB-IV chemical 

mechanism. The entire "ozone season" was modeled (May 1 – September 30), using a 12-

km modeling grid, covering the state of Georgia and parts of the neighboring states 

(boundary conditions were obtained from simulations using a larger domain). Given the 

relatively flat terrain of the Atlanta area and the distance from the coastline, a 12-km 

modeling grid should be sufficient for characterizing the spatial patterns in ozone 

response to control measures. This is also supported in Cohan et al. (2006), in which the 

effect of grid resolution of sensitivity analyses results was investigated. 

7.1 Cases Modeled 

Sensitivities were modeled relative to 2009 emissions, to evaluate the efficiency of 

various control strategies to be implemented by the start of the 2009 ozone season. 

Sensitivities to both ground-level emissions (e.g., mobile, area) and elevated emissions 

(e.g., major power plants) were modeled. Five ground-level cases and five major pointsources were modeled. Note that Plant Bowen, Plant Wansley, and Plant Hammond Unit 

4 were not included in the analysis since they currently have selective catalytic reduction 

devices installed on all their major units. The following is a detailed list of the 10 cases 

that were modeled: 

1. 10% Atlanta ground-level NOx: a reduction of 10% in anthropogenic groundlevel NOx emissions in the Atlanta 20 county nonattainment area (average 

reduction of 37.1 tons-per-day compared to 2009 emissions). 

2. 10% Atlanta ground-level VOC: a reduction of 10% in anthropogenic groundlevel VOC emissions in the Atlanta 20 county nonattainment area (average 

reduction of 52.1 tons-per-day compared to 2009 emissions). 

3. 10% Atlanta on-road NOx: a reduction of 10% in anthropogenic ground-level 

on-road NOx emissions in the Atlanta 20 county nonattainment area (average 

reduction of 23.2 tons-per-day compared to 2009 emissions).

4. 10% Atlanta non-road NOx: a reduction of 10% in anthropogenic ground-level 

non-road NOx emissions in the Atlanta 20 county nonattainment area (average 

reduction of 8.9 tons-per-day compared to 2009 emissions).

5. 10% Atlanta area NOx: a reduction of 10% in anthropogenic ground-level areasource NOx emissions in the Atlanta 20 county nonattainment area (average 

reduction of 3.8 tons-per-day compared to 2009 emissions).
The Atlanta Eight-Hour Ozone Attainment Demonstration 

144 

6. SCRs at Branch: Installation of selective catalytic reduction devices (SCRs) on 

Plant Branch units 1-4 (average reduction of 50.9 tons-per-day compared to preinstallation emissions; assuming a decrease in emissions rate from 0.42 

lb/MMBtu to 0.07 lb/MMBtu).

7. SCRs at Hammond: Installation of selective catalytic reduction devices (SCRs) 

on Plant Hammond units 1-3 (average reduction of 11.8 tons-per-day compared to 

pre-installation emissions; assuming a decrease in emissions rate from 0.20 

lb/MMBtu to 0.07 lb/MMBtu).

8. SCRs at McDonough: Installation of selective catalytic reduction devices (SCRs) 

on Plant McDonough units 1-2 (average reduction of 7.5 tons-per-day compared 

to pre-installation emissions; assuming a decrease in emissions rate from 0.23 

lb/MMBtu to 0.07 lb/MMBtu).

9. SCRs at Scherer: Installation of selective catalytic reduction devices (SCRs) on 

Plant Scherer units 1-4 (average reduction of 26.8 tons-per-day compared to preinstallation emissions; assuming a decrease in emissions rate from 0.14 

lb/MMBtu to 0.07 lb/MMBtu).

10. SCRs at Yates: Installation of selective catalytic reduction devices (SCRs) on 

Plant Yates units 1-7 (average reduction of 24.0 tons-per-day compared to preinstallation emissions; assuming a decrease in emissions rate from 0.21 

lb/MMBtu to 0.07 lb/MMBtu). 

7.2 Results 

The results of the sensitivity analysis are reported in terms of the average reduction in 

daily maximum 8-hour ozone at model grid-cells corresponding to monitoring sites, for 

days in which the 2002 base-case modeled daily maximum 8-hour ozone was above 85 

ppb (or a minimum of 10 days, using a lower threshold), following the approach 

recommended in the EPA modeling guidance (EPA, 2007). Both absolute reductions 

(ppb) and reductions normalized per ton-per-day of precursor controlled (ppt/TPD) are 

reported. Modeled reductions at each site were scaled by the 2002 5-year ozone design 

value (DV) used for attainment demonstrations. 

Sensitivity analysis results for the Confederate Avenue site in Atlanta are reported in 

Table 7-1, and Figures 7-1 and 7-2. This site was chosen since its DV is the highest of all 

the Atlanta nonattainment area sites. Sensitivity results for other sites in the Atlanta 

nonattainment area are reported in Appendix F, and generally show similar patterns. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 7-1: Summary of sensitivity analysis results for the Atlanta Confederate 

Avenue site (AIRS ID 13-121-0055) 

Sensitivity TPD 

reduction 

Average1

Reduction in 

O3 (ppb) 

Normalized average1

reduction in O3

(ppt/TPD) 

10% Atlanta ground-level NOx 37.1 1.41 38.1 

10% Atlanta ground-level VOC 52.1 0.09 1.7 

10% Atlanta on-road NOx 23.2 0.92 39.5 

10% Atlanta non-road NOx 8.9 0.28 31.7 

10% Atlanta area NOx 3.8 0.14 36.5 

SCRs at Branch 50.9 0.22 4.4 

SCRs at Hammond 11.8 0.04 3.4 

SCRs at McDonough 7.5 0.27 35.7 

SCRs at Scherer 26.8 0.17 6.2 

SCRs at Yates 24.0 0.21 9.0 

1

Using modeled days in which the 2002 modeled 8-hr ozone concentration was above 85 

ppb. 

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

6/1

6/8

6/15

6/22

6/29

7/6

7/13

7/20

7/27

8/3

8/10

8/17

8/24

8/31

9/7

Reduction in max 8-hr ozone (ppb)

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

110.0

Daily max 8-hr ozone (ppb)

10% NOx 10% VOC 2009 base-case

Figure 7-1: Modeled 2009 daily maximum 8-hr ozone at the Confederate Avenue site, 

along with the modeled reductions in ozone for a 10% control of ground level, 

anthropogenic, non-EGU NOx and VOC emissions. Red diamonds denote days in which 

the 2002 model results were above 85 ppb, and such days were included calculation of 

the average reductions reported in Table 7-1. 

145 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

6/16/8

6/156/226/29

7/6

7/137/207/27

8/3

8/108/178/248/31

Reduction in max 8-hr ozone (ppb)

9/7

0.0

20.0

40.0

60.0

80.0

100.0

120.0

Branch Hammond McDonough Scherer Yates 2009 base-case

Figure 7-2: Modeled 2009 daily maximum 8-hr ozone at the Confederate Avenue 

site, along with the modeled reductions in ozone associated with the installation of SCRs 

at plants Bowen, Hammond, McDonough, Scherer and Yates. Red diamonds denote days 

in which the 2002 model results were above 85 ppb, and such days were included 

calculation of the average reductions reported in Table 7-1. 

7.3 Discussion 

Results from the sensitivity analysis clearly indicate that NOx controls are substantially 

more efficient in reducing peak ozone concentrations compared to VOC controls (38.1 

vs. 1.7 ppt/TPD, respectively), indicating to NOx limited conditions. Relatively minor 

differences in control efficiency are observed for the various ground-level NOx sources 

(39.5, 31.7, 36.5 ppt/TPD for on-road, non-road and area NOx, respectively), likely due to 

both atmospheric turbulence resulting in mixing of emissions prior to peak ozone and to 

"artificial" dilution of emissions using in model grids. 

NOx controls at Plant McDonough are more efficient in controlling ozone than at other 

power plants in Georgia (35.7 vs. 3.4-9.0 ppt/TPD, respectively), due to its location 

within the Atlanta nonattainment area, but its absolute reduction is fairly similar to that of 

plants Branch, Scherer and Yates (0.27, 0.22, 0.17, 0.19 ppb, respectively). 

Results for other sites within the nonattainment area (shown in Appendix F) typically 

show a similar pattern, with a tendency to increased efficiency of ground-level NOx

controls over VOC controls outside of the core urban area (as represented here by the 

Confederate Avenue site).

146 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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8.0 OTHER CLEAN AIR ACT REQUIREMENTS 

Sections 172(c), 182(a) and 182(b) of the CAA, as amended, contain the requirements for 

ozone nonattainment areas. As a subpart 2 moderate ozone nonattainment area, the 

Atlanta area must meet the requirements for both a marginal and moderate area, as well 

as the general requirements contained in Section 172(c). These requirements were listed 

in Table 1-4. 

8.1 RACT/RACM Requirements 

Section 172(c)(1) of the CAA requires SIPs to provide for the implementation of all 

reasonably available control measures (RACM) to demonstrate attainment as 

expeditiously as practicable. A subset of RACM is RACT, which relates specifically to 

stationary point sources. All available RACM measures that are not considered RACT 

have been exhausted through nearly three decades of ozone nonattainment planning for 

Atlanta and have been included in previous SIPs. Section 182(b)(2) of the CAA, for 

areas classified as moderate nonattainment status for ozone, requires RACT rules to be 

adopted for all point sources of VOC and NOx emissions with potential to emit at least 

100 tons per year or greater. As a portion of the 8-hour ozone metro Atlanta region is 

subject to RACT rules for the 1-hour ozone maintenance plan, RACT requirements apply 

for some sources of VOC and NOx emissions which have lower emission thresholds. 

Georgia’s RACT demonstration is contained in Chapter 10 of this document. 

8.2 Reasonable Further Progress 

Section 182(b)(1) of the CAA mandates a 15 percent VOC emission reduction, 

accounting for growth, in the first 6 years after the baseline year (2002) for moderate and 

above ozone nonattainment areas. Thus for the metro Atlanta nonattainment area, a 

reasonable further progress (RFP) analysis between 2002 and 2008 is required. 

Georgia EPD is submitting an RFP SIP under separate cover. 

8.3 Actual Emissions Inventory 

Section 182(a)(1) and Section 172(c)(3) require the development of a comprehensive, 

accurate current inventory of actual emissions from all sources of VOC and NOx in the 

nonattainment area. Such inventory was due two years after designation of the 8-hour 

ozone nonattainment areas, or by June 15, 2006. The Georgia EPD met this requirement 

through the submittal of the 2002 emission inventories under the Consolidated Emission 

Reporting Rule (CERR) for the metro Atlanta counties in this nonattainment area. 

The final 2002 emission inventories used in the attainment demonstration will go through 

the public hearing process with the full attainment demonstration, which will include any 

updates or revisions that are necessary since the CERR submittal. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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8.4 Emissions Inventory Statement 

Section 182(a)(3)(B) requires the SIP to contain a requirement for all owners or operators 

of stationary sources located in the nonattainment area and that emit either VOC or NOx 

to submit a statement of actual emissions annually. The State may waive the requirement 

for sources that emit less than 25 tons per year of NOx or VOC emissions. The 

requirement for such emissions statements was previously required by Rule 391-3-1-

.02(6)(a)4 for the original 13 counties for stationary sources, defined as those which emit 

more than 25 tons per year of NOx or VOC emissions subject to the previous old 1-hour 

ozone nonattainment SIP. Emission statement for stationary sources that emit more than 

25 tons per year of NOx or VOC emissions were required by an amendment to that same 

rule effective March 12, 2007 for the additional 7 counties. 

8.5 Periodic Emissions Inventory 

Section 172(c)(3) and 182(a)(3)(A) require periodic inventory submittals. Specifically, 

Section 182(a)(3)(A) requires the inventory be submitted every three years until the area 

is redesignated to attainment. The Georgia EPD met this requirement by submitting the 

CERR inventory to EPA on June 1, 2007. 

8.6 Permit Program Requirements 

Sections 172(c)(5) and 182(a)(2)(C) require a permit program consistent with the 

requirements of Section 173. Additionally, Section 182(b)(5) requires an offset 

requirement of 1.15 to 1. Georgia EPD updated rules for nonattainment new source 

review (NNSR) effective July 25, 2007, including updating the new offset requirement. 

The Georgia EPD has met the permit program requirements for a moderate nonattainment 

area. 

8.7 Inspection and Maintenance Program 

Section 182(b)(4) requires moderate and above ozone nonattainment areas to implement 

a vehicle inspection and maintenance (I/M) program. To meet this requirement for the 

Atlanta 1-hour ozone nonattainment area, a decentralized idle test was implemented as 

part of the previous Atlanta 1-hour ozone SIP. In the 13 counties3

 of the former Atlanta 

1-hour ozone nonattainment area there is an annual enhanced I/M program, with onboard 

diagnostics system checks on 1996 and newer model year cars and light trucks; 2-mode 

ASM tests on 25-year-old through 1995 model year vehicles; a check for catalytic 

converter tampering on 25-year-old through 1995 model year vehicles; a gas cap pressure 

test on all subject vehicles; and technician training and certification. The existing 13-

county I/M program has been determined to be sufficient to meet the requirements of 

section 182(b)(4) for the 20-county nonattainment area (see Appendix S). 

3

 Cherokee (13057), Clayton (13063), Cobb (13067), Coweta (13077), DeKalb (13089), Douglas (13097), 

Fayette (13113), Forsyth (13117), Fulton (13121), Gwinnett (13135), Henry (13151), Paulding (13223), 

and Rockdale (13247) 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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8.8 Other Measures 

Section 172(c)(6) requires the nonattainment SIPs to include enforceable limitation and 

other control measures, along with schedules for compliance as needed to demonstrate 

attainment. Chapters 5 and 10 provide a discussion of state and federal control measures 

that help the metro Atlanta area make progress in attaining the ozone standard. 

8.9 Compliance with Section 110(a)(2) 

Section 172(c)(7) requires nonattainment SIPs to meet the applicable provisions of 

Section 110(a)(2). The Georgia EPD has reviewed the requirements of Section 110(a)(2) 

and has concluded that, except for the provisions of 110(a)(2)(G), the prior rule 

submittals, along with this attainment demonstration plan address the relevant 

requirements. On March 27, 2008, EPA published a finding that the state of Georgia has 

failed to submit a SIP addressing the emergency episode plan requirements of section 

110(a)(2)(g). EPD intends to comply with the requirements published in this Federal 

Register notice in order correct this deficiency. 

8.10 Equivalent Techniques 

The Georgia EPD believes that the procedures for modeling, emissions inventory and 

planning follow the USEPA guidance and is not requesting approval for equivalent 

techniques, as envisioned under Section 172(c)(8). 

8.11 Contingency 

8.11.1 Contingency Overview 

The Clean Air Act requires States containing nonattainment areas to adopt contingency 

measures that will take effect without further action by the State or USEPA upon a 

determination by the USEPA that an area failed to demonstrate Reasonable Further 

Progress (RFP) or to timely attain the applicable NAAQS, as described in section 

172(c)(9). 

8.11.2 Contingency Measures 

Section 172(c)(9) of the Clean Air Act requires states to identify and include contingency 

measures in their attainment demonstration plans. Contingency measures must take 

effect without significant further action by the State or USEPA upon a determination by 

EPA that an area has either failed to demonstrate Reasonable Further Progress (RFP) 

toward attainment or attainment of the applicable NAAQS. Contingency measures are 

additional control measures to be implemented in the event that an area fails to meet RFP 

or fails to attain the standards by its attainment date. These contingency measures must 

be fully adopted rules or control measures that are ready to be implemented quickly upon 

failure to meet RFP or failure of the area to meet the standard by its attainment date. 

These measures should consist of other control measures for the area that are not included 

in the control strategy for the SIP.” 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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8.11.3 Contingency Emission Reductions for Failure to Attain 

The Clean Air Act requires nonattainment areas to implement control measures necessary 

to meet the federal air quality standards. Through analysis and modeling a state 

demonstrates attainment based in the implementation of a State Implementation Plan. If 

a nonattainment area does not attain the federal standard by the prescribed attainment 

date then the nonattainment area is required to implement contingency measures within a 

year of a federal register notice that the area did not meet its attainment date. The 

contingency measures, if needed, must be measures that will take effect without further 

action by the State or the Administrator. 

The attainment date for Atlanta as a moderate nonattainment area is June 15, 2010, under 

the 8-hour ozone NAAQS. However, attainment of the standard is based on the threeyear design value that averages the ozone seasons of 2007, 2008 and 2009. Therefore, 

the 2009 design value is the marker by which attainment will be judged. States will be 

notified if they did not meet the 8-hour ozone NAAQS in 2010 based on a review of the 

2009 design value. One year from the date of notification the identified contingency 

measures must be fully implemented. This means that contingency measure must 

provide emission reductions in the 2011 timeframe to meet the contingency requirements. 

The attainment contingency requirements can be met by demonstrating that significant 

emission reduction will occur from specific measures implemented after 2009. 

Georgia's state only contingency measures for this attainment demonstration SIP are as 

follows: 

• NOx controls on Coal-Fired Power Plants; 

• Voluntary Initiative to Reduce Railyard Emissions; 

Except for the voluntary initiative to reduce railyard emissions, these measures are 

controls that are either currently required by an adopted state rule or are currently 

undergoing the rulemaking process to be adopted at a later date, but prior to the 

attainment date required of this SIP revision. The measures and their scheduled 

implementation dates are described in the following paragraphs. 

NOx Controls on Coal-Fired Power Plants

Georgia Rule 391-3-1-.02(2)(sss), Multipollutant Control for Electric Utility Steam 

Generating Units, requires owners/operators of specific coal-fired electric steam 

generating units to install additional controls for one or more pollutants. The units are 

required to be equipped with NOx controls after May 1, 2009. At this time the 

owners/operators anticipate using selective catalytic reduction for emission reductions of 

NOx. The affected units and the required installation dates are specified in Table 8.1. 

Because these controls are required by an existing Georgia rule, they will take effect 

without further action by Georgia or EPA. 

While the table below demonstrates that state rule requires NOx reductions to be 

implemented in the near future, only Georgia Power Plant Scherer Unit 3 and Georgia 

Power Plant McDonough Unit 2 may specifically qualify to be a contingency measure in 

the requisite time period. 
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Table 8-1: Multipollutant Control Requirements for Certain Coal-Fired Boilers 

AIRS No. Plant/Unit County Capacity 

(MW) 

Fuel Type Deadline for 

Installation and 

Operation of 

NOx Control 

04-13-207-00008 Georgia Power Plant 

Scherer Unit 3 

Monroe 891 Subbitumino

us Coal 

12/31/2011 

04-13-067-00003 Georgia Power Plant 

McDonough Unit 2 

Cobb 299 Bituminous 

Coal 

12/31/2011 

04-13-067-00003 Georgia Power Plant 

McDonough Unit 1 

Cobb 299 Bituminous 

Coal 

4/30/2012 

04-13-207-00008 Georgia Power Plant 

Scherer Unit 4 

Monroe 891 Subbitumino

us Coal 

12/31/2012 

04-13-237-00008 Georgia Power Plant 

Branch Unit 3 

Putnam 544 Bituminous 

Coal 

12/31/2013 

04-13-207-00008 Georgia Power Plant 

Scherer Unit 2 

Monroe 891 Subbitumino

us Coal 

12/31/2013 

04-13-237-00008 Georgia Power Plant 

Branch Unit 4 

Putnam 544 Bituminous 

Coal 

06/01/2014 

04-13-237-00008 Georgia Power Plant 

Branch Unit 1 

Putnam 299 Bituminous 

Coal 

12/31/2014 

04-13-237-00008 Georgia Power Plant 

Branch Unit 2 

Putnam 359 Bituminous 

Coal 

12/31/2014 

04-13-207-00008 Georgia Power Plant 

Scherer Unit 1 

Monroe 891 Subbitumino

us Coal 

12/31/2014 

04-13-077-00001 Georgia Power Plant 

Yates Unit 6 

Coweta 403 Bituminous 

Coal 

06/01/2015 

04-13-077-00001 Georgia Power Plant 

Yates Unit 7 

Coweta 403 Bituminous 

Coal 

06/01/2015 

Voluntary Reduction of Emissions from Railyards in the Metro Atlanta Region

Railroad-related emissions of NOx are a major contributor to ozone concentrations in 

many of Georgia's nonattainment counties. Cost-effective options are available to 

significantly reduce NOx emissions from locomotive engines, however federal 

regulations do not currently require or allow states to require their use. In addition, 

recent federal regulations for these engines would not significantly reduce their emissions 

to the level possible for many years. EPD is pursuing a voluntary emissions reduction 

program and has been awarded a $36,200,000 grant from Georgia Department of 

Transportation under the Congestion Mitigation and Air Quality improvement program 

(CMAQ) to negotiate the use of emission reduction technologies and techniques with 

railroad companies operating in the Atlanta area. EPD anticipates emission reductions 

based on this contingency measure after 2010. A detailed discussion of voluntary 

emission reduction measures is discussed further in Appendix T. EPD will amend this 

SIP upon completion of the contractual obligation with the Class I railroads that operate 

in the Atlanta NAA. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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9.0 MOTOR VEHICLE EMISSIONS BUDGETS 

9.1 Background 

Attainment demonstrations are control strategy SIP revisions. As such, they establish 

motor vehicle emissions budgets (MVEBs). A motor vehicle emissions budget is 

described in EPA's transportation conformity rule4

 as "...the implementation plan's 

estimate of future [motor vehicle] emissions." Such budgets establish caps on motor 

vehicle emissions; projected emissions from transportation plans and programs must be 

equal to or less than these caps for a positive conformity determination to be made. 

9.2 Establishment of 2009 Motor Vehicle Emissions Budgets for the 

Atlanta 8-Hour Ozone Nonattainment Area 

Note that the motor vehicle emissions budgets being established with this Attainment 

Demonstration are essentially the 2009 mobile5

 source emission inventories for the 

Atlanta nonattainment area and do not include emissions from outside the nonattainment 

area. 

 

In preparation for establishing budgets with this Attainment Demonstration, EPD worked 

closely with the Atlanta Regional Commission (ARC) to develop the best possible 

estimates of mobile source emissions for the 20-county Atlanta nonattainment area, using 

the MOBILE6 emission factor model6

 and ARC's link-based emissions estimation 

procedure. The projected mobile source emissions inventories reflect all federal and state 

mobile source control rules, including federal tailpipe standards, low-sulfur and low-Reid 

vapor pressure (RVP) gasoline,7

 and, in the 13 counties of the former 1-hour ozone 

standard nonattainment area, enhanced I/M and Stage II refueling vapor recovery. See 

Appendix U for details of the mobile source emissions modeling used for MVEB 

development. 

One adjustment had to be made to the calculated tons per day emissions inventories to 

arrive at the final motor vehicle emissions inventories. This adjustment accounts for the 

loss of credit from a state rule allowing exemption from vehicle inspection and 

maintenance (I/M) for cars 10 years old or older driven fewer than 5,000 miles per year 

and owned by persons 65 years old or older. It was estimated that this senior I/M 

exemption increased VOC and NOx emissions by 0.05 and 0.03 tons per day, 

respectively, in 2002. This senior I/M exemption emissions debit for 2002 is 

conservatively high and was also added to the 2009 budget year inventories. See "Effect 

of Senior Exemption on 2002 Highway Mobile Source Emissions" in Appendix U, 

Exhibit 6, for details of the senior exemption credit loss calculations. 

4

 40 CFR Part 93.124(a) 

5

 The term "mobile" is used to describe emissions from on-road motor vehicles. The term "nonroad" is 

used to describe emissions from off-road equipment and vehicles. 6 http://www.epa.gov/otaq/m6.htm#m60

7

 The MVEB inventories reflect a later planning assumption than do the air quality modeling inventories: a 

100% market share of 10% ethanol-blend gasoline (E10) is assumed, with a volatility waiver that, per 

Georgia's Gasoline Marketing Rule, allows RVP for E10 allows to rise from 7.0 to 8.0 pounds per square 

inch. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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As noted above, the 2009 mobile source VOC and NOx emissions inventories were 

developed using the ARC's link-based emissions estimation procedure (see Appendix U). 

These inventories reflect the most recent planning assumptions and emission factor 

model8

 available, and the use of updated travel demand and emissions calculation 

models. The methodology used to calculate the highway mobile source emissions on 

which the updated 2009 MVEBs are based is discussed below and, in greater detail, in 

Appendix U. 

The MOBILE6.2 motor vehicle emission factor model was used to calculate 2009 VOC 

and NOx emission factors with all 2009 mobile source control rules in place. Two sets of 

emission factors were produced to properly reflect different fleet characteristics9

 and 

mobile source emissions controls in the 13-county and 7-county parts of the 20-county 

nonattainment area. 

The 13-county controls include: annual enhanced I/M with onboard diagnostics system 

checks on 1996 and newer model year vehicles; 2-mode ASM tests on 25-model-year-old 

through 1995 vehicles; a check for catalytic converter tampering on 25-model-year-old 

through 1995 vehicles; a gas cap pressure test on all subject vehicles; low-sulfur and lowRVP gasoline; Stage II gasoline refueling vapor recovery; the Federal Motor Vehicle 

Control Program (FMVCP), including Tier 1 and (beginning with 2004 models) Tier 2 

tailpipe standards; the National Low Emission Vehicle (NLEV) program; and technician 

training and certification. 

For the 7-county part of the nonattainment area, the emission factors reflect Georgia's 

low-sulfur/low-RVP gasoline and all federal controls (e.g., FMVCP, NLEV). 

The emission factors resulting from the separate MOBILE6.2 runs for the 13-county and 

7-county parts of the 20-county nonattainment area were used with ARC's link-based 

emissions estimation procedure to calculate 2009 tons per day emissions in the following 

manner: 

• For each of four times of day (a.m. peak, midday, p.m. peak, and night), the HPMSadjusted10 and summer-adjusted 2009 VMT and speeds from each link in ARC's 

travel demand model were multiplied by the 2009 MOBILE6.2 emission factor at the 

average speed closest to the congested-flow speed on that link. 

• Emissions from all the links and all four time periods were summed together to get 

grams per day inventories, which were divided by 907,180 to convert from grams per 

day to tons per day. 

These mobile source inventories reflect the most up-to-date mobile modeling 

assumptions, including 2009 VMT projected from a state-of-the-art travel demand model 

8

 MOBILE6.2.03 

9

 Separate registration distributions by age were modeled for the 13-county and 7-county parts of the 20-

county nonattainment area. 

10 The VMT from the travel demand model were adjusted based on the VMT estimates that GDOT 

develops for the Highway Performance Monitoring System (HPMS). 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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for the 20 counties and July 2009 emission factors from EPA's latest mobile source 

emission factor model, MOBILE6.2.03. 

Details of the mobile source emissions modeling methodology used for MVEB 

development, along with the MOBILE6.2 input files and other documentation, are in 

Appendix U (Mobile Source Emissions Modeling for Atlanta Ozone Attainment 

Demonstration Motor Vehicle Emissions Budgets). 

Table 9-1 sums the calculated mobile source emissions inventories for the 20-county 

Atlanta ozone nonattainment area and the 13-county senior exemption emissions 

increases. 

Table 9-1: Total 20-County 2009 Motor Vehicle Emissions Budgets 

VOC (tons/day) NOx (tons/day)

2009 Mobile Emissions Subtotal (MOBILE6.2 results) 163.82 252.24

Senior I/M Exemption Increases + 0.05 + 0.03

Total 2009 Motor Vehicle Emissions Budgets 163.87 252.27

This Attainment Demonstration hereby establishes 2009 motor vehicle emissions budgets 

of 163.87 and 252.27 tons per day, VOC and NOx, respectively, for the 20-county 

Atlanta 8-hour ozone nonattainment area. Interagency consultation among the relevant 

agencies occurred during the development of these MVEBs and prior to the submittal of 

this Attainment Demonstration. Full implementation plan documentation was provided 

to EPA, and EPA's stated concerns have been addressed. 

The MVEBs established by this Attainment Demonstration are based on new estimates of 

VMT and speeds from an updated, state-of-the-art travel demand model; on the latest 

version of EPA's motor vehicle emission factor model (MOBILE6.2.03); and on 

registration distributions by age developed using registration data11 obtained from R.L. 

Polk & Company. 

To show the MVEB "together with all other emissions sources12," point, area, and nonroad emissions from 2009 modeling inventories developed by the VISTAS/ASIP 

contractors were used.13 Table 9-2 below shows the 2009 nonattainment area emissions 

inventories for all sectors: 

Table 9-2: 2009 20-County Atlanta Nonattainment Area Projected Emissions 

Point Area Nonroad Mobile Total 

VOC (tons/summer day) 19.41 313.72 85.46 163.87 582.46 

NOx (tons/summer day) 69.47 35.07 103.25 252.27 460.06 

 

11 Registration data was from R. L. Polk & Co.'s National Vehicle Population Profile ® current as of 

October 2002 and from R. L. Polk & Co.'s TIPNet ® current as of March 2003. See Appendix U, Exhibit 

2, for more details on the registration distribution by age. 

12 Section 93.118(e)(4)(iv) of the transportation conformity rule requires that the "motor vehicle emissions 

budget(s), when considered together with all other emissions sources, is consistent with applicable 

requirements for...attainment...." 

13 See Tables 3-2 and 3-3. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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10.0 REASONABLY AVAILABLE CONTROL 

TECHNOLOGY (RACT) ANALYSIS 

10.1 Introduction 

Under the former 1-hr ozone NAAQS, the 13-county Atlanta non-attainment area, 

consisting of Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, 

Fulton, Gwinnett, Henry, Paulding and Rockdale Counties, was classified as a severe 

non-attainment area. Georgia EPD implemented RACT for ozone precursors VOC and 

NOx in accordance with applicable provisions of the CAA. These RACT provisions are 

still in place as part of the 1-hour ozone metro Atlanta maintenance plan. The 1997 

eight-hour ozone NAAQS classifies the 20-county Atlanta non-attainment area consisting 

of Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, 

Fayette, Forsyth, Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding 

and Walton, as a moderate nonattainment area. According to the EPA’s Final Rule to 

Implement the 8-Hour Ozone NAAQS – Phase 2 (40 CFR§51.912, November 29, 2005), 

for each subpart 2 are classified moderate or above, the State shall submit a SIP revision 

that meets the VOC and NOx RACT requirements in sections 182(b)(2) and 182(f) of the 

CAA, respectively. The deadline for submittal of a SIP revision fulfilling the 

requirements of 40 CFR Part 51.912 is December 31, 2008. In addition, the State shall 

provide for implementation of RACT as expeditiously as practicable but no later than the 

first ozone season or portion thereof which occurs 30 months after the RACT SIP is due. 

10.1.1 RACT 

RACT is defined as the lowest emissions limitation, that a particular source is capable of 

meeting, by the application of control technology that is reasonably available considering 

technological and economical feasibility (44 FR 53762; September 17, 1979). 

Documents useful in establishing RACT include Control Techniques Guidelines (CTGs), 

Alternative Control Technique guidance (ACT), Maximum Achievable Control 

Technology (MACT) standards, New Source Performance Standards (NSPS), and Best 

Available Control Technology (BACT) standards. RACT requirements are included in 

the CAA to assure that significant source categories at major sources of ozone precursor 

emissions are controlled to a “reasonable” extent, but not necessarily to best available 

control technology (BACT) levels expected of new major sources major modifications to 

existing major sources or to maximum achievable control technology (MACT) required 

for major sources of hazardous air pollutants. 

10.1.2 Clean Air Act Section 182(b)(2) Requirements 

Section 182(b)(2) requires that areas classified as moderate for ozone nonattainment 

include provisions to require the implementation of Reasonably Available Control 

Technology under section 172(c)(1) with respect to three VOC categories. Section 

182(b)(2)(A) covers the VOC CTG categories updated or created between November 15, 

1990 and the particular date of attainment. Section 182(b)(2)(B) covers the VOC CTG 

categories for which a CTG was issued prior to November 15, 1990. Section 

182(b)(2)(C) covers all other major stationary sources of VOCs that are located in the 

area [metro Atlanta eight-hour ozone non-attainment area]. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

156

The abbreviation CTG stands for Control Techniques Guidelines and sections 108 and 

183 of the CAA provide more background into the role CTGs play in helping States meet 

section 182(b)(2) requirements as they relate to VOC emissions. The EPA has issued 

CTG documents defining presumptive RACT levels for existing facilities that emit large 

amounts of air pollutants The CAA [section 183(e)] requires the EPA to revise RACT, 

update existing CTG documents, or develop new documents, on a frequent basis to 

provide states and local agencies with the most current technical information and assist 

them in determining RACT. The EPA has issued updates to existing CTG documents 

and CTGs for several new categories beginning in 2006. Each of these CTG updates (or 

new CTGs) come with the requirement to state and local agencies to submit a SIP 

revision that either certifies or demonstrates that the existing or proposed RACT 

represents RACT in light of the updated or new CTGs. 

Pursuant to section 183(c), EPA has issued technical documents which identify 

alternative controls for certain categories of stationary sources of VOC [and/or NOx] 

emissions which have a potential to emit 25 tons per year or more of each air pollutant. 

The alternative controls are documented in an Alternative Control Technology (ACT) 

document and ACTs do not define presumptive RACT levels. 

Under the former 1-hour ozone NAAQS, Georgia EPD implemented VOC emission 

reductions that met section 182(b)(2) RACT requirements for Cherokee, Clayton, Cobb, 

Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding and 

Rockdale Counties. The VOC emission threshold for implementing Section 182(b)(2) 

VOC RACT requirements in the former 1-hour ozone NAAQS area ranged from 15 

pounds of VOC emissions per day up to 25 tons per year. The section 182(b)(2) VOC 

RACT requirements are specified in Georgia Rule 391-3-1-.02(2) under Emission 

Limitations and Standards. 

Section 182(b)(2) of the CAA, in this case, specifies additional deadlines for SIP 

revisions pertaining to VOC RACT. The submittal deadline for SIP revisions pursuant to 

sections 182(b)(2)(B) and 182(b)(2)(C) of the CAA are equivalent to 40 CFR Part 

51.912. Submittal deadlines for SIP revisions pursuant to section 182(b)(2)(A) are 

specified in CTG’s issued between November 15, 1990 and the attainment date. 

Submittal deadlines for SIP revisions pursuant to section 182(b)(2)(A) are October 5, 

2007, October 9, 2008, and September 30, 2009 depending on the VOC source category. 

This SIP revision will address the need to demonstrate that existing and/or updated VOC 

emission standards in Chapter 391-3-1-.02(2) fulfill eight-hour RACT requirements for 

all VOC sources in the metro Atlanta that are covered by a CTG document, excluding the 

CTG categories promulgated on September 30, 2008 [i.e., SIP deadline is September 30, 

2009]. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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10.1.3 Clean Air Act Section 182(f) Requirements

SIP revisions required under section 182(b) for major stationary sources of VOCs shall 

also apply to major stationary sources of NOx pursuant to section 182(f) of the CAA. 

Major stationary sources of VOC and NOx is defined in section 302 and section 302 

defines a major stationary source of either air pollutant as one which has a potential to 

emit of 100 tons per year or greater. 

Under the former 1-hour ozone NAAQS, Georgia EPD implemented NOx emission 

reductions that met section 182(f) requirements for Cherokee, Clayton, Cobb, Coweta, 

DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding and Rockdale 

Counties. The NOx emission threshold for implementing Section 182(f) NOx emission 

reductions in the former 1-hour ozone NAAQS area ranged from 1 ton per year of NOx 

emissions per day up to 25 tons per year. In fact, some NOx emission limitations and 

standards applied if certain equipment was constructed and operated in the applicable 

county irregardless of NOx emissions. The section 182(f) NOx emission reductions are 

specified in Georgia Rule 391-3-1-.02(2) under Emission Limitations and Standards. 

As noted earlier, the EPA has issued CTG documents defining presumptive VOC RACT 

levels for existing facilities. EPA has also issued several CTGs and ACTs for source 

categories emitting NOx. There are no additional deadlines for SIP revisions pertaining 

to NOx RACT. 

This SIP revision will address the need to demonstrate that existing and/or updated NOx 

emission standards in Chapter 391-3-1-.02(2) fulfill eight-hour RACT requirements for 

all NOx sources in the metro Atlanta are covered by a CTG document. 

10.1.4 8-Hour Ozone RACT SIP Analysis Elements

Georgia EPD reviewed RACT SIP analysis elements provided in various out of state SIP 

submittals including Baltimore, Charlotte, Dallas-Fort Worth (DFW), and the San 

Joaquin Valley Unified Air Pollution Control District (SJVUAPCD). Georgia EPD is 

developing its SIP analysis in a manner very similar to DFW and SJVUAPCD. Georgia 

EPD’s 8-hour ozone RACT SIP analysis includes the following elements: 

3⁄4 RACT demonstration for source categories covered under section 182(b)(2)(A) 

of the CAA as they relate to VOC and NOx emissions. 

3⁄4 RACT demonstration for source categories covered under section 182(b)(2)(B) of 

the CAA as they relate to VOC and NOx emissions. 

3⁄4 RACT demonstration for non-CTG source categories covered under section 

182(b)(2)(C) of the CAA as they relate to VOC and NOx emissions. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

158

10.2.1 RACT Demonstration for Source Categories Covered Section 182(b)(2)(A) of 

the Clean Air Act 

Section 182(b)(2)(A) of the CAA pertains to each category of VOC and/or NOx sources 

in the area covered by a CTG document issued by the Administrator between the date of 

the enactment of the CAAA of 1990 [November 15, 1990] and the date of attainment. 

The Georgia EPD reviewed CTG and ACT documents issued between November 15, 

1990 and the present moment which includes Groups II, III, and IV CTGs. Table 10-1 

specifies the applicable CTG and/or ACT source categories that fall under this section of 

the CAAA of 1990 for NOx and VOC emissions. 

The Georgia EPD examined the applicable state rules mentioned in Table 10-1 to verify 

that they satisfy the corresponding RACT requirements for the applicable CTG source 

categories. To determine if the control technologies associated with the existing state 

emission specifications fulfill RACT requirements for the relevant unit types, the Georgia 

EPD compared the existing state regulations to the controls contained in the CTG and 

ACT guidance documents. State regulations that implement the controls suggested in 

CTG and ACT documents or that implement equivalent emission control strategies were 

determined to fulfill RACT requirements. 

Because EPA must evaluate SIP-related rules prior to approval to determine if those rules 

fulfill all applicable U.S.EPA guidelines and policies, any U.S.EPA 1-hour ozone SIPapproved rules were determined to meet the RACT requirements at the time of federal 

approval. Each of the federally approved state rules mentioned in Table 10-1 were 

evaluated to determine if they fulfilled the RACT requirements for the 8-hour ozone 

standard. Georgia EPD is not aware of any significant changes in control technology that 

affect original RACT determinations approved for the 1-hour ozone NAAQS. As such, 

Georgia EPD is certifying through this SIP revision, that the VOC state rules mentioned 

in Table 10-1 satisfy the RACT requirements of 100 tons per year or more for the 

applicable CTG sourced categories. Negative declarations have been made for VOC 

source categories where there are no major emission sources within the metro Atlanta 

nonattainment area. 

The emission specifications in the Georgia Rules that regulate all major sources of NOx 

emissions in the area consistently contain lower NOx emission limits than those 

established by ACT documents, EPA guidelines and policies, and those technologies and 

methodologies currently considered RACT by the EPA and other affected states. These 

rules include Georgia Rules 391-3-1-.02(2)(yy), (jjj), (lll), (mmm), and (nnn) which are 

mentioned in Table 10-1. Therefore, EPD is certifying through this SIP revision that 

these NOx emission standards satisfy the RACT requirements of 100 ton per year or 

more. Negative declarations have been made for NOx source categories where there are 

no major emission sources within the metro Atlanta nonattainment area. 

A majority of VOC provisions in Georgia Rule 391-3-1-.02(2) apply statewide based on 

county-specific VOC emission thresholds. The applicability of the VOC provisions that 

do not apply statewide have been extended to the additional 7 counties that make up the 

metro Atlanta non-attainment area. In addition, these VOC provisions apply year-round. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

159

The applicable NOx rules already applied to the 7 additional counties and no change is 

being implemented at this time and they apply May 1 through September 31. 

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

VOC ACT Alternative Control Technology 

Document – Organic Waste Process 

Vents, EPA-450/3-91-007, 

December 1990. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

NOx ACT NOx Emissions from Nitric and 

Adipic Acid Manufacturing Plants, 

EPA-453/3-91-026, December 

1991. 

Georgia Rule 391-3-1-

.02(2)(i): Emission 

Limitations and Standards, 

Nitric Acid Plants. 

VOC ACT Control of Volatile Organic 

Compound Emissions from 

Industrial Wastewater CTG (draft), 

EPA-453/D-93-056, September 

1992. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

CTG not finalized but issued 

as ACT in 1994. 

VOC ACT Bakery Ovens ACT, EPA-453/R92-017, December 1992. No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

NA NA Control Techniques for Volatile 

Organic Compound Emissions from 

Stationary Sources, EPA-453/R-92-

018, December 1992. 

This document is often listed 

with CTGs, but it does not 

define RACT for any 

particular source. 

NOx ACT NOx Emissions from Stationary 

Combustion Turbines, EPA-453/R93-007, January 1993. 

Georgia Rule 391-3-1-

.02(2)(mmm): Emission 

Limitations and Standards, 

NOx Emissions from 

Stationary Gas Turbines and 

Stationary Engines used to 

Generate Electricity; and 

 

Georgia Rule 391-3-1-

.02(2)(nnn): Emission 

Limitations and Standards, 

NOx Emissions from Large 

Stationary Gas Turbines. 

VOC ACT Control of VOC Emissions from the 

Application of Agricultural 

Pesticides, EPA-453/R-92-011, 

March 1993. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

160

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

NOx ACT NOx Emissions from Stationary 

Internal Combustion Engines, EPA453/R-93-032, July 1993. 

Georgia Rule 391-3-1-

.02(2)(mmm): Emission 

Limitations and Standards, 

NOx Emissions from 

Stationary Gas Turbines and 

Stationary Engines used to 

Generate Electricity. 

Updated September 2000. 

VOC CTG Control of Volatile Organic 

Compound Emissions from 

Reactor Processes and Distillation 

Operations in Synthetic Organic 

Chemical Manufacturing Industry 

EPA-450/4-91-031 

August 1993 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Control of Volatile Organic 

Compound Emissions from Offset 

Lithographic Printing, EPA-453/D95-001, September 1993. 

CTG created and issued in October 

2006. 

Georgia Rule 391-3-1-

.02(2)(ddd): Emission 

Limitations and Standards, 

VOC Emissions from Offset 

Lithography. 

NOx ACT NOx Emissions from Process 

Heaters, EPA-453/R-93-034, 

September 1993. 

The ACT appears to be focused on 

petroleum refining industry. 

Revised September 1993. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Alternative Control Techniques 

Document – Volatile Organic 

Liquid Storage In Floating and 

Fixed Roof Tanks, EPA-453/R-94-

001, January 1994. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Control of Volatile Organic 

Compound Emissions from Batch 

Processes ACT, EPA-453/R-93-

020, February 1994. 

 

Document also released under the 

Report ID of EPA-453/R-93-017. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Alternative Control Techniques 

Document – Industrial Cleaning 

Solvents, EPA-453/R-94-015, 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

161

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

February 1994. 

VOC ACT Alternative Control Techniques 

Document – Surface Coating of 

Automotive/Transportation and 

Business Machine Plastic Parts, 

EPA-453/R-94-017, February 1994. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

NOx ACT NOx Emissions from Cement 

Manufacturing, EPA-453/R-94-004, 

March 1994. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

Updated September 2000. 

NOx ACT NOx Emissions from Industrial, 

Commercial & Institutional Boilers, 

EPA-453/R-94-022, March 1994. 

Georgia Rule 391-3-1-

.02(2)(lll): Emission 

Limitations and Standards, 

NOx Emissions from FuelBurning Equipment; and 

Georgia Rule 391-3-1-

.02(2)(rrr): Emission 

Limitations and Standards, 

NOx Emissions from Small 

Fuel-Burning Equipment. 

NOx ACT Alternative Control Techniques 

Document – NOx Emissions from 

Utility Boilers, EPA-453/R-94-023, 

March 1994. 

Georgia Rule 391-3-1-

.02(2)(jjj): Emission 

Limitations and Standards, 

NOx Emissions from 

Electric Utility Steam 

Generating Units. 

Rule (jjj) applies to only coal 

combustion, but all Georgia 

Utilities are covered by this 

rule. 

VOC ACT Alternative Control Technology 

Document – Surface Coating 

Operations at Shipbuilding and Ship 

Repair Facilities, EPA-453/R-94-

032, April 1994. 

For CTG, see 61 FR-44050, August 

27,1996. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area.
The Atlanta Eight-Hour Ozone Attainment Demonstration 

162

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

VOC ACT Industrial Wastewater Alternative 

Control Technology, (No Report 

ID), April 1994. 

ACT consists of cover memo with 

option tables + CTG (draft) EPA453/D-93-056. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Alternative Control Techniques 

Document – Automotive 

Refinishing, EPA-453/R-94-031, 

April 1994. 

A national rule for autobody 

refinishing was issued in 

1998 after the ACT. 

VOC ACT Alternative Control Techniques 

Document – Surface Coating 

Operations at Shipbuilding and Ship 

Repair Facilities, EPA-453/R-94-

032, April 1994. 

This ACT was superseded by the 

Ship Building CTG issued in 

August 1996. 

Not applicable. 

NOx ACT Alternative Control Techniques 

Document – NOx Emissions from 

Glass Manufacturing, EPA-453/R94-037, June 1994 

Only one major source in the 

Atlanta 8-hr ozone nonattainment area (Owens 

Brockway, AIRS No. 

12100020). 

This source is subject to 

Georgia Rule 391-3-1-

.02(2)(yy): Emission 

Limitations and Standards, 

Emissions of Nitrogen 

Oxides from Major Sources, 

and underwent a case-bycase RACT analysis. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

163

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

NOx ACT Alternative Control Techniques 

Document – NOx Emissions from 

Iron and Steel Mills, EPA 453/R94-065, September 1994. 

Only one major source in the 

Atlanta 8-hr ozone nonattainment area (Gerdau 

Ameristeel, AIRS No. 

1500032). 

This source is subject to 

Georgia Rule 391-3-1-

.02(2)(yy): Emission 

Limitations and Standards, 

Emissions of Nitrogen 

Oxides from Major Sources, 

and underwent a case-bycase RACT analysis. 

VOC CTG Control of Volatile Organic 

Compound Emissions from Coating 

Operations at Aerospace 

Manufacturing and Rework 

Operations 

EPA-453/R-97-004 

EPA-68/D1-00115 

EPA-453/D-96-016, December 

1997 

MACT see 59 FR 29216, June 6, 

1994 

Georgia Rule 391-3-1-

.02(2)(kkk): Emission 

Limitations and Standards, 

VOC Emissions from 

Aerospace Manufacturing 

and Rework Facilities 

VOC CTG Control of Volatile Organic 

Compound Emissions from Wood 

Furniture Manufacturing Operations 

EPA-453/D-95-002 

EPA-453/R-96-007, April 1996 

Draft MACT out: May 1994 

61 FR 25223 – May 20, 1996 

61 FR 50823 – September 27, 1996 

Georgia Rule 391-3-1-

.02(2)(hhh):Emission 

Limitations and Standards, 

Wood Furniture Finishing 

and Cleaning Operations 

VOC CTG Group II: Control Techniques 

Guidelines for Flexible Packaging 

Printing 

EPA-453/R-06-003 

September 2006 

Georgia Rule 391-3-1-

.02(2)(mm): Emission 

Limitations and Standards, 

VOC Emissions from 

Graphic Arts Systems 

VOC CTG Group II: Control Techniques 

Guidelines for Offset Lithographic 

Printing and Letterpress Printing, 

EPA-453/R-06-002 

September 2006 

Georgia Rule 391-3-1-

.02(2)(ddd): Emission 

Limitations and Standards, 

VOC Emissions from Offset 

Lithography 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

164

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

VOC CTG Group II: Control Techniques 

Guidelines for Industrial Cleaning 

Solvents 

EPA-453/R-06-001 

September 2006 

Reduction in VOC emissions 

from the use of industrial 

cleaning solvents is covered 

under a majority of the VOC 

emission provisions in 

Georgia Rule 391-3-1-.02(2).

VOC CTG Group II: Control Techniques 

Guidelines for Flat Wood Paneling 

Coatings 

EPA-453/R-06-004 

September 2006 

Georgia Rule 391-3-1-

.02(2)(jj): Emission 

Limitations and Standards, 

VOC Emissions from 

Surface Coating of Flat 

Wood Paneling 

VOC CTG Group III: Control Techniques 

Guideline for Paper, Film, and Foil 

Coatings 

EPA-453/R-07-003 

September 2007 

Georgia Rule 391-3-1-

.02(2)(w): Emission 

Limitations and Standards, 

VOC Emissions from Paper 

Coating 

VOC CTG Group III: Control Techniques 

Guidelines for Metal Furniture 

Coatings 

EPA-453/R-07-005 

September 2007 

Georgia Rule 391-3-1-

.02(2)(y): Emission 

Limitations and Standards, 

VOC Emissions from Metal 

Furniture Coating 

VOC CTG Group III: Control Techniques 

Guidelines for Large Appliance 

Coatings 

EPA-453/R-07-004 

September 2007 

Georgia Rule 391-3-1-

.02(2)(z): Emission 

Limitations and Standards, 

VOC Emissions from Large 

Appliance Surface Coating 

VOC CTG Group IV: Control Techniques 

Guidelines for Miscellaneous Metal 

and Plastic Parts Coatings 

EPA-453/R-08-003 

September 2008 

To be determined. Update 

will be submitted in separate 

SIP revision. 

VOC CTG Group IV: Control Techniques 

Guidelines for Automobile and 

Light-Duty Truck Assembly 

Coatings 

EPA-453/R-08-002 and –006 

September 2008 

To be determined. Update 

will be submitted in separate 

SIP revision. 

VOC CTG Group IV: Control Techniques 

Guidelines for Fiberglass Boat 

Manufacturing Materials 

EPA-453/R-08-004 

September 2008 

To be determined. Update 

will be submitted in separate 

SIP revision. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

165

Table 10-1: Source Categories Covered Section 182(b)(2)(A) of the Clean Air Act 

Air 

Pollutant 

CTG 

and/or 

ACT? 

Source Category State Regulations Fulfilling 

RACT Requirements 

VOC CTG Group IV: Control Techniques 

Guidelines for Miscellaneous 

Industrial Adhesives 

EPA-453/R-08-005 

To be determined. Update 

will be submitted in separate 

SIP revision. 

Table 10-4 specifies the metro Atlanta area facilities whose operations have potential 

VOC or NOx emissions greater than 100 tons per year and have process equipment 

covered under a CTG and/or ACT covered under this chapter. 

10.2.2 RACT Demonstration for Source Categories Covered Section 182(b)(2)(B) of 

the Clean Air Act 

Section 182(b)(2)(B) of the CAA pertains to each category of VOC and/or NOx sources 

in the area covered by a CTG document issued by the Administrator prior to the date of 

the enactment of the CAAA of 1990, namely November 15, 1990. Table 10-2 specifies 

the applicable CTG and/or ACT source categories that fall under this section of the 

CAAA of 1990 for VOC emissions. Note that there are no applicable CTGs or ACTs 

that fall under this section of the CAA. 

The Georgia EPD examined the applicable state rules mentioned in Table 10-2 to verify 

that they satisfy the corresponding RACT requirements for the applicable CTG source 

categories. To determine if the control technologies associated with the existing state 

emission specifications fulfill RACT requirements for the relevant unit types, the Georgia 

EPD compared the existing state regulations to the controls contained in the CTG and 

ACT guidance documents. State regulations that implement the controls suggested in 

CTG and ACT documents or that implement equivalent emission control strategies were 

determined to fulfill RACT requirements. 

Because EPA must evaluate SIP-related rules prior to approval to determine if those rules 

fulfill all applicable U.S.EPA guidelines and policies, any U.S.EPA 1-hour ozone SIPapproved rules were determined to meet the RACT requirements at the time of federal 

approval. Each of the federally approved state rules mentioned in Table 10-1 were 

evaluated to determine if they fulfilled the RACT requirements for the 8-hour ozone 

standard. Georgia EPD is not aware of any significant changes in control technology that 

affect original RACT determinations approved for the 1-hour ozone NAAQS. As such, 

Georgia EPD is certifying through this SIP revision, that the VOC state rules mentioned 

in Table 10-2 satisfy the RACT requirements of 100 tons per year or more for the 

applicable CTG sourced categories. Negative declarations have been made for VOC 

source categories where there are no major emission sources within the metro Atlanta 

nonattainment area. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

166

Georgia EPD has updated these VOC state rules to be applicable in the 7 additional 

counties that make up the 8-hour ozone metro Atlanta nonattainment area on March 1, 

2009 at a potential VOC emissions threshold of 100 tons per year. 

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

VOC CTG Design Criteria for Stage I Vapor 

Control Systems – Gasoline Service 

Stations 

EPA-450/R-75-102 

Georgia Rule 391-3-1-

.02(2)(rr): Emission 

Limitations and Standards, 

Gasoline Dispensing Facility 

– Stage I; 

This reference document is 

regarded as a CTG although 

it was never published with 

an EPA document number. 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume I: Control 

Methods for Surface Coating 

Operations, 

EPA-450/2-76-028 

November 1976 

Although often listed with 

the CTGs for historical 

reasons, this reference 

document does not define 

RACT for any source. It is a 

compilation of control 

techniques. 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume II: Surface 

Coating of Cans, Coils, Paper, 

Fabrics, Automobiles, and LightDuty Trucks 

EPA-450/2-77-008 

May 1977 

Georgia Rule 391-3-1-

.02(2)(t): Emission 

Limitations and Standards, 

VOC Emissions from 

Automobile and Light-Duty 

Truck Manufacturing 

Georgia Rule 391-3-1-

.02(2)(u): Emission 

Limitations and Standards, 

VOC Emissions from Can 

Coating; 

Georgia Rule 391-3-1-

.02(2)(v): Emission 

Limitations and Standards, 

VOC Emissions from Coil 

Coating; 

Georgia Rule 391-3-1-

.02(2)(w): Emission 

Limitations and Standards, 

VOC Emissions from Paper 

Coating; and 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

167

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

Georgia Rule 391-3-1-

.02(2)(x): Emission 

Limitations and Standards, 

VOC Emissions from Fabric 

and Vinyl Coating. 

VOC CTG Control of Volatile Organic 

Emissions from Solvent Metal 

Cleaning 

EPA-450/2-77-022 

November 1977 

Georgia Rule 391-3-1-

.02(2)(ff): Emission 

Limitations and Standards, 

Solvent Metal Cleaning. 

VOC CTG Control of Refinery Vacuum 

Producing Systems, Wastewater 

Separators, and Process Unit 

Turnarounds 

EPA-450/2-77-026 

October 1977 

Georgia Rule 391-3-1-

.02(2)(ee): Emission 

Limitations and Standards, 

Petroleum Refinery 

VOC CTG Control of Hydrocarbons from Tank 

Truck Gasoline Loading Terminals 

EPA-450/2-77-026 

October 1977 

Georgia Rule 391-3-1-

.02(2)(cc): Emission 

Limitations and Standards, 

Bulk Gasoline Terminals 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume III: Surface 

Coating of Metal Furniture, 

EPA-450/2-77-032 

December 1977 

Georgia Rule 391-3-1-

.02(2)(y): Emission 

Limitations and Standards, 

VOC Emissions from Metal 

Furniture Coating 

VOC CTG Control of Volatile Organic 

Emissions Stationary Sources – 

Volume IV: Surface Coating of 

Insulation of Magnet Wire 

EPA-450/2-77-033 

December 1977 

Georgia Rule 391-3-1-

.02(2)(aa): Emission 

Limitations and Standards, 

VOC Emissions from Wire 

Coating 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume V: Surface 

Coating of Large Appliances 

EPA-450/2-77-034 

December 1977 

Georgia Rule 391-3-1-

.02(2)(z): Emission 

Limitations and Standards, 

VOC Emissions from Large 

Appliance Surface Coating 

VOC CTG Control of Volatile Organic Georgia Rule 391-3-1-
The Atlanta Eight-Hour Ozone Attainment Demonstration 

168

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

Emissions from Bulk Gasoline 

Plants 

EPA-450/2-77-035 

December 1977 

.02(2)(pp): Emission 

Limitations and Standards, 

Bulk Gasoline Plants. 

VOC CTG Control of Volatile Organic 

Emissions from Use of Cutback 

Asphalt 

EPA-450/2-77-037 

December 1977 

Georgia Rule 391-3-1-

.02(2)(dd): Emission 

Limitations and Standards, 

Cutback Asphalt 

VOC CTG Control Techniques for Volatile 

Organic Emissions from Stationary 

Sources 

EPA-450/2-78-015 

May 1978 

This document is often listed 

with CTGs, but it does not 

define RACT for any 

particular source. 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume VI: Surface 

Coating of Miscellaneous Metal 

Parts and Products 

EPA-450/2-78-015 

June 1978 

Georgia Rule 391-3-1-

.02(2)(ii): Emission 

Limitations and Standards, 

VOC Emissions from 

Surface Coating of Flat 

Wood Paneling 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume VII: Factory 

Surface Coating of Flat Wood 

Paneling 

EPA-450/2-78-032 

June 1978 

Georgia rule 391-3-1-

.02(2)(jj): Emission 

Limitations and Standards, 

VOC Emissions from 

Surface Coating of Flat 

Wood Paneling 

VOC CTG Control of Volatile Organic 

Compound Leaks from Petroleum 

Refinery Equipment 

EPA-450/2-78-036 

June 1978 

Georgia Rule 391-3-1-

.02(2)(hh): Emission 

Limitation and Standards, 

Petroleum Refinery 

Equipment Leaks 

VOC CTG Control of Volatile Organic 

Emissions from Manufacture of 

Synthesized Pharmaceutical 

Products 

EPA-450/2-78-029 

December 1978 

Georgia Rule 391-3-1-

.02(2)(kk): Emission 

Limitations and Standards, 

VOC Emissions from 

Synthesized Pharmaceutical 

Manufacturing 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

169

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

VOC CTG Control of Volatile Organic 

Emissions from Manufacture of 

Pneumatic Rubber Tires, 

EPA 450/2-78-030 

December 1978 

Georgia Rule 391-3-1-

.02(2)(ll): Emission 

Limitations and Standards, 

VOC Emissions from the 

Manufacture of Pneumatic 

Rubber Tires 

VOC CTG Control of Volatile Organic 

Emissions from Existing Stationary 

Sources – Volume VIII: Graphic 

Arts-Rotogravure and Flexography 

EPA-450/2-78-033 

December 1978 

Georgia Rule 391-3-1-

.02(2)(mm): Emission 

Limitations and Standards, 

VOC Emissions from 

Graphic Arts Systems. 

VOC CTG Control of Volatile Organic 

Emissions from Petroleum Liquid 

Storage in External Floating Roof 

Tanks 

EPA-450/2-78-047 

December 1978 

Georgia Rule 391-3-1-

.02(2)(nn): Emission 

Limitations and Standards, 

VOC Emissions from 

External Floating Roof 

Tanks 

VOC CTG Control of Volatile Organic 

Emissions from Perchloroethylene 

Dry Cleaning Systems 

EPA-450/2-78-050 

December 1978 

Perchloroethylene has been 

exempted as a VOC, so this 

CTG is no longer relevant. 

However, there is a MACT 

standard for 

perchloroethylene dry 

cleaners. 

VOC CTG Control of Volatile Organic 

Compound Leaks from Gasoline 

Tank Trucks and Vapor Collection 

Systems 

EPA-450/3-78-051 

December 1978 

Georgia Rule 391-3-1-

.02(2)(ss): Emission 

Limitations and Standards, 

Gasoline Transport Vehicles 

and Vapor Collection 

Systems. 

VOC CTG Control of Volatile Organic 

Compound Emissions from Large 

Petroleum Dry Cleaners 

EPA-450/3-82-009 

September 1982 

Georgia Rule 391-3-1-

.02(2)(qq): Emission 

Limitations and Standards, 

Large Petroleum Dry 

Cleaners. 

VOC ACT Control Techniques for Organic 

Emissions from Plywood Veneer 

Dryers, EPA-450/3-83-012, May 

1983. 

Georgia Rule 391-3-1-

.02(2)(jj): Emission 

Limitations and Standards, 

VOC Emissions from 

Surface Coating of Flat 

Wood Paneling. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

170

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

This document is labeled as 

a control technique 

document (CTD) rather than 

an ACT. However, the 

information is similar to that 

in an ACT. 

VOC CTG Control of Volatile Organic 

Compound Emissions from 

Manufacture of High-Density 

Polyethylene, Polypropylene, and 

Polystyrene Resins 

EPA-450/3-83-008 

November 1983 

Georgia Rule 391-3-1-

.02(2)(qq): Emission 

Limitations and Standards, 

VOC Emissions from 

Extruded Polystyrene 

Products Manufacturing 

Utilizing a Blowing Agent. 

VOC CTG Control of Volatile Organic 

Compound Emissions from 

Equipment Leaks from Natural 

Gas/Gasoline Processing Plants 

EPA-450/3-83-007 

December 1983 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC CTG Control of Volatile Organic 

Compound Leaks from Synthetic 

Organic Chemical Polymer and 

Resin Manufacturing Equipment 

EPA-450/3-83-006 

March 1984 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC CTG Control of Volatile Organic 

Compound Emissions from Air 

Oxidation Processes in Synthetic 

Organic Chemical Manufacturing 

Industry 

EPA-450/3-84-015 

December 1984 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Reduction of Volatile Organic 

Compound Emissions from the 

Application of Traffic Markings, 

EPA-450/3-88-007, August 1988. 

The Architectural and 

Industrial Maintenance 

coatings (AIM) national rule 

issued in 1998 includes 

limits for traffic coatings and 

superseded the ACT. 

VOC ACT Reduction of Volatile Organic No existing major sources in 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

171

Table 10-2: Source Categories Covered Section 182(b)(2)(B) of the Clean Air Act 

Air 

Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT and Notes 

Concerning the ACT. 

Compound Emissions from 

Automobile Refinishing, EPA450/3-88-009, October 1988. 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Alternative Control Technology 

Document – Ethylene Oxide 

Sterilization / Fumigation 

Operations, EPA 450/3-89-007, 

March 1989. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Alternative Control Technology 

Document – Halogenated Solvent 

Cleaners, EPA-450/3-89-030, 

August 1989. 

No existing major sources in 

the Atlanta 8-hour ozone 

non-attainment area. 

VOC ACT Control of VOC Emissions from 

Polystyrene Foam Manufacturing, 

EPA-450/3-90-020, September 

1990. 

Georgia Rule 391-3-1-

.02(2)(eee): Emission 

Limitations and Standards, 

VOC Emissions from 

Expanded Polystyrene 

Products Manufacturing; and 

Georgia Rule 391-3-1-

.02(2)(qqq): Emission 

Limitations and Standards, 

VOC Emissions from 

Extruded Polystyrene 

Products Manufacturing 

Utilizing a Blowing Agent. 

Table 10-4 specifies the metro Atlanta area facilities whose operations have potential 

VOC or NOx emissions greater than 100 tons per year and have process equipment 

covered under a CTG and/or ACT covered under this chapter. 

10.2.3 RACT Demonstration for Non-CTG Source Categories Covered Section 

182(b)(2)(C) of the Clean Air Act 

Section 182(b)(2)(C) of the CAA pertains to non-CTG [and non-ACT] major stationary 

sources of VOCs and NOx located in the metro Atlanta area. Identification of applicable 

sources came by reviewing the state results of the Consolidated Emissions Reporting 

Rule (CERR) and Georgia EPD’s permitting database. 

The major source thresholds used in this analysis is 100 tons per year for VOC and/or 

NOx emissions in accordance with the 8-hour ozone implementation rule. Georgia EPD 

reviewed the 2002 emission inventory database required by the Consolidated Emissions 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

172

Reporting Rule (CERR) for emission sources that reported 100 tons per year of VOC 

emissions. These sources were reviewed in order to determine if there are major sources 

of VOC emissions not covered by a CTG. Since any major source of VOC emissions are 

required to have a Title V operating permit, Georgia EPD also reviewed the Title V 

database to ensure there were no additional sources of VOC emissions that might have 

Title V permits or applications pending. Georgia EPD followed the same procedure to 

find major sources of NOx emissions as was used to find major sources of VOC 

emissions. 

Table 10-3: Source Categories Covered Section 182(b)(2)(C) of the Clean Air Act 

Air Pollutant Alternative Control Technology 

(ACT) Reference Document 

Corresponding State Rule 

Fulfilling RACT 

VOC Volatile Organic Liquid and 

Handling and Storage 

Georgia Rule 391-3-1-

.02(2)(vv): Emission 

Limitations and Standards: 

Volatile Organic Liquid and 

Handling and Storage. 

VOC Consumer and Commercial 

Products – Windshield Wiper 

Fluids 

Georgia Rule 391-3-1-

.02(2)(aaa): Emission 

Limitations and Standards: 

Consumer and Commercial 

Products 

VOC Gasoline Marketing Georgia Rule 391-3-1-

.02(2)(bbb): Emission 

Limitations and Standards: 

Gasoline Marketing 

VOC Bulk Mixing Georgia Rule 391-3-1-

.02(2)(ccc): Emission 

Limitations and Standards: 

VOC Emissions from Bulk 

Mixing Tanks 

VOC Case-by-Case Georgia Rule 391-3-1-

.02(2)(tt): Emission 

Limitations and Standards: 

VOC Emissions from Major 

Sources 

NOx Case-by-Case Georgia Rule 391-3-1-

.02(2)(yy): Emissions of 

Nitrogen Oxides from Major 

Sources 

The Georgia EPD stationary source permitting program conducted a case-by-case RACT 

review as part of permit application processing for the applicable sources. The case-bycase RACT reviews were all conducted as part of Georgia EPD’s Title V permit 

application review. The results of these case-by-case RACT reviews were also examined 

by the permitting program at EPA Region 4 as part of its Title V permitting program. 

These case-by-case RACT reviews are contained within EPA Region 4 approved Title V 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

173

air quality permits issued by Georgia EPD. The regulatory authority given for case-bycase RACT reviews is specified by Georgia Rules 391-3-1-.02(2)(tt) and (yy) for VOC 

and NOx emissions, respectively. 

Georgia EPD believes that the existing Georgia Rule (tt) and Georgia Rule (yy) permit 

conditions satisfy RACT for purposes of sections 172(c), 182(a), and 182(b) of the CAA. 

Therefore, Georgia EPD is certifying through this SIP revision, that the Georgia Rule (tt) 

and (yy) permit conditions satisfy RACT requirements of 100 tons per year of more. 

Table 10-4 specifies the Georgia air quality permit conditions for metro Atlanta facilities 

whose potential VOC and/or NOx emissions equal to or are greater than 100 tons per 

year that satisfy RACT requirements for non-CTG [and non-ACT] source categories (i.e., 

case-by-case RACT. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

Case-by-case RACT plan for VOincorporated as a whole into air qplan to be supplied to EPA upon 

1300005 Barrow 

JOHNS MANVILLE CORP 

Fiberglass insulation products manufacturing facility 

VOC NOx 

1500011 Bartow 

GEORGIA POWER COMPANY – PLANT BOWEN 

Electric utility VOC 

NOx 

Georgia Rule 391-3-1-.02(2)(tt) dcontrols for VOC emissions. Electric utility steam generating uNOx emission standards specified 391-3-1-.02(2)(jjj) . Combustion turbines are subject standards specified by Georgia R.02(2)(nnn). 

1500032 Bartow 

GERDAU AMERISTEEL CORP/Birmingham SE 

Steel Mill VOC 

NOx 

Georgia Rule 391-3-1-.02(2)(tt) dadditional controls for VOC emisNOx emissions minimized by reqnatural gas be burned in the reheaand tundish nozzle preheaters, tunpreheaters, rolling mill cutting toand ladle heater in accordance wiNOx emissions from the reheat fu

174
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

pounds of NOx per million Btu in Georgia Rule (yy) for PSD AvoidNOx emissions from the electric 0.15 pounds of NOx per ton of staccordance with Georgia Rule (y

1500061 Bartow 

ANHEUSER-BUSCH COMPANIES INC 

Beer Brewery VOC 

NOx 

Georgia Rules 391-3-1-.02(2)(tt) no controls for VOC emissions. Boilers limited to burning natural during the period May 1 through during periods of natural gas curtminimization of NOx emissions p391-3-1-.02(2)(yy). Permittee must perform annual tuminimize NOx emissions per Geo.02(2)(yy). 

175
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

4500008 Carroll 

SOUTHWIRE COMPANY - COPPER DIVISION 

Copper rod production facility. 

VOC Rod mill quenching and cooling 

to the vapor recovery system to memissions in accordance with GeThe vapor recovery system (VRSrod mill shaft furnace during opeminimize VOC emissions in accoRule (tt). No additional controls are require391-3-1-.02(2)(tt) to minimize V

4500012 Carroll 

SOUTHWIRE COMPANY – CARROLLTON BUILDING WIRE PLANT 

Insulated and noninsulated wire production facility. 

VOC 

4500038 Carroll 

SOUTHWIRE COMPANY-MACHINE SERVICES 

Operation of a wire manufacturing facility along with machining equipment. 

VOC VOC emissions from the paint bo

accordance with Georgia Rule (ttcoatings with no more than 3.5 lbcoating minus water. If that limit Permittee must comply with the sof 6.67 lbs VOC/gallon of coatinthe coating applicator. 

4500043 Carroll 

SOUTHWIRE COMPANY - COFER TECHNOLOGY CENTER 

Research and Development for Southwire Company 

VOC No additional controls are require

391-3-1-.02(2)(tt) to minimize V

176
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

4500051 Carroll 

SOUTHWIRE COMPANY-CORPORATE ENERGY MGMT 

Provides emergency and peaking power to coowned and co-located Southwire Company 

VOC NOx 

No additional controls are require391-3-1-.02(2)(tt) to minimize VIC engines listed at 1,552 hp are Rule (mmm) to minimize NOx emIC engines are subject to Part 63 MACT). 

4500052 Carroll 

SOUTHWIRE COMPANY – CARROLLTON UTILITY PRODUCTS 

Insulated and noninsulated wire production facility. 

VOC VOC emissions from the paint bo

accordance with Georgia Rule (ttcoatings with no more than 3.5 lbcoating minus water. If that limit Permittee must comply with the sof 6.67 lbs VOC/gallon of coatinthe coating applicator. 

177
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

5700036 Cherokee 

ATLANTA GAS LIGHT CO LNG PLANT/Cherokee LNG 

Liquefied Natural Gas Plant. 

NOx Turbine T1 is subject to a NOx em

ppmv @ 15% oxygen in accordanRule (yy). This turbine is subject RACT due to age and/or size. 

IC engines with source codes C1G4 are subject to a NOx emission ppmv @ 15% oxygen in accordanRule (yy). These IC engines are Georgia Rule (mmm); however, taccepted a more stringent NOx empurposes of NSR avoidance. Vaporizer Boilers with sources coVB9 are subject to Georgia Rule emissions. 

6300059 Clayton 

DELTA AIR LINES INCATLANTA STATION Operation of a facility that services airports and 

flying vehicles. 

VOC Surface coating operations are su

(kkk) and the Aerospace MACT emissions. Petroleum storage tanks are subje(bb) to minimize VOC emissionsGasoline dispensing facility is suRules (rr) and (zz) to minimize V

178
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

NOx and VOC 

Solvent metal cleaning operationGeorgia Rule (ff) to minimize VOIC engines can only be used to gewhen electric power is not availautility or during test runs conductpurposes for no more than 200 hoconsecutive 12-month period. 

6300105 Clayton 

DELTA AIR LINES TECHNICAL OPERATIONS CTR 

Operation of a facility that services airplanes. 

VOC NOx and VOC 

Aerospace surface coating and/or operations are subject to Georgia Aerospace MACT, Part 63 SubpaVOC emissions. Non-aerospace surface coating anoperations are subject to Georgia and work practice standards of Gminimize VOC emissions. IC engines can only be used to gewhen electric power is not availautility or during test runs conductpurposes for no more than 200 hoconsecutive 12-month period. 

179
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

Perform annual tune-ups in accormanufacturer’s recommendations combustion equipment. Only fire natural gas in IC enginecombustion equipment except dunatural gas curtailment. Boiler rated at or near 61 MMBtuGeorgia Rule (lll) to minimize NO

12100807 Clayton 

DELTA AIRLINES – GENERAL OFFICE 

Operation of a facility that services airplanes. 

VOC NOx and VOC 

Non-aerospace surface coating anoperations are subject to the work of Georgia Rule (kkk) to minimizNon-aerospace solvent cleaning ocomply with Georgia Rule (ff). Cleaning of non-aerospace spray with the cleaning provisions of Gnamely subparagraph 7. Gasoline dispensing facility operwith Georgia Rules (rr) and (zz). IC engines in the following equip

180
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

NOx 

under hours of operation limits in consecutive months to minimize emissions under Georgia Rules (tEquipment Group IC 21: 4000 hEquipment Group IC22: 2256 hoEquipment Group IC23: 1500 hoEquipment Group IC24: 3500 hoIC engines in Equipment Groups and IC24 shall comply with Georminimize NOx emissions. 

6700022 Cobb 

AUSTELL BOX BOARD CORP/Caraustar Industries 

Facility produces paper from recycled wastepaper. 

NOx Subject to Georgia Rule 391-3-1-

Diesel Fueled Emergency Firefigonly 380 hrs per any 12-month peCoal-fired boiler is subject to a Nstandard of 0.38lbs/MMBTU herolling average) from May 1 thro

Coal-fired boiler is subject to a Nstandard of 0.65lbs/MMBTU heyear – 30 day rolling average. Coal-fired boiler: Annual inspec

181
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

air pre-heater and boiler burners, throat repairs and combustion air maintenance. Every 1000 hrs premaintenance on 3 pulverizers and coal to boiler. Tune-ups on standby boilers at apmonth intervals. 

6700003 Cobb 

GA POWER CO PLANT MCDONOUGH 

Georgia Rule 391-3-1-.02(2)(tt) dcontrols for VOC emissions. Electric utility steam generating uNOx emission standards specified 391-3-1-.02(2)(jjj) . 

Electric utility VOC 

NOx 

Combustion turbines are subject standards specified by Georgia R.02(2)(nnn). 

6700074 Cobb 

COLONIAL PIPELINE COMPANY– ATLANTA JUNCTION 

Pipeline breakout facility for refined petroleum products 

VOC Gasoline storage tanks are subjec

391-3-1-.02(2)(bb) and (bbb) to memissions. 

7700001 GA POWER CO PLANT 

YATES 

Electric utility VOC 

Coweta 

Georgia Rule 391-3-1-.02(2)(tt) dcontrols for VOC emissions. 

182
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

NOx Electric utility steam generating u

NOx emission standards specified 391-3-1-.02(2)(jjj) . 

Combustion turbines are subject standards specified by Georgia R.02(2)(nnn). 

7700010 Coweta 

Nos. 5 and 6 furnaces subject to 4Subpart RRR for VOC emissionsWet paint coating operation is su391-3-1-.02(2)(ii) to minimize V

BON L. MANUFACTURING COMPANY, INC. 

Aluminum Extrusion Facility 

VOC 

NOx emissions from the furnacesare subject to Georgia Rule 391-3Boiler can only combust natural gaccordance with Georgia Rule 39

NOx 

No. 5 Furnace shall only burn natmonths of May through Septembused as an alternative if natural gAnnual tuneup required to optimi

183
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

performance as it relates to NOx No. 6 Furnace shall only burn natmonths of May through Septembused as an alternative if natural gPermittee shall not operate furnacpercentage of greater than 10%. NOx emissions from brite dip opminimized by the use of a caustic must provide at least 25% NOx roperation of brite dip system. Subject to Georgia Rule 391-3-1-only natural gas and propane in bnatural gas on other equipment duexcept during times of curtailmenas alternative. Operate caustic scoperation to provide 25% remova5 furnace burners to optimize fueoperating point with least NOx em3% oxygen) and safe CO levels iin No. 6 furnace less than 10%. 

184
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

8900086 DeKalb 

GENERAL MOTORS MIDSIZE CAR DIV. - DORAVILLE 

Automobile and lightduty truck assembly plant VOC 

NOx 

Plant is closed and their air qualitrevoked. Georgia EPD is awardiNOx emission credits. 

8900100\ DeKalb 

CHEVRON PRODUCTS CO 

Bulk Gasoline Terminal VOC Gasoline storage tanks subject to 

3-1-.02(2)(bb), (cc), (nn) (ss), and VOC emissions. 

Gasoline transport vehicles are suRule (ss) to minimize VOC emisLoading rack for gasoline terminVOC emission standard of 0.67 p1000 gallons of gasoline transferr(cc). 

8900121 DeKalb 

MAGELLAN TERMINALS HOLDINGS LP #2/Conoco 

Operation of a bulk gasoline terminal. 

VOC VOC emissions minimized facilit

accordance with Georgia Rule 39and 40 CFR part 63 Subpart R. 

185
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

VOC emissions from internal flominimized in accordance with Ge.02(2)(bb) and (vv) as well as 40 Subparts K and Kb. VOC emissions from external flominimized in accordance with Ge.02(2)(bb) and (nn). VOC emissions from gasoline loaminimized in accordance with Ge.02(2)(cc) and (ss). 

8900128 DeKalb 

TRANSMONTAIGNE TERMINALING, INC. 

Operation of a bulk gasoline terminal. 

VOC VOC emissions minimized facilit

accordance with Georgia Rule 39

VOC emissions from internal flominimized in accordance with Ge.02(2)(bb)as well as 40 CFR Part VOC emissions from external flominimized in accordance with Ge.02(2)(nn). 

186
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

VOC emissions from gasoline loaminimized in accordance with Ge.02(2)(cc) and (ss). 

8900224 DeKalb 

DART CONTAINER CORPORATION OF GEORGIA 

Operation of an expandable polystyrene container manufacturing plant. 

VOC NOx 

Solvent metal cleaning operationGeorgia Rule (ff). 

Storage tanks with a capacity equ20,000 gallons are subject to GeoEPS process is subject to Georgia NOx emissions from the boilers aRule (rrr), namely annual tune-upmanufacturer recommendations anatural gas, pentane, LPG, or proSeptember. 

8900005 DeKalb 

CENTERS FOR DISEASE CONTROL (CDC) 

Public health research NOx Subject to Georgia Rules 391-3-1

(mmm). 

08900131 DeKalb 

MOTIVA ENTERPRISES DORAVILLE COMPLEX 

Operation of a bulk petroleum, marketing terminal 

VOC Subject to Georgia Rules 391-3-1

(ss). 

11700005 Forsyth 

AMERICAN PROTEINS INC CUMMING DIV 

Poultry Rendering Facility 

VOC Case-by-case RACT plan for VO

incorporated as a whole into air qplan to be supplied to EPA upon 

187
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

Cumming NOx 

NOx emissions from boilers subj(rrr) – do not fire No. 2 fuel oil dMay 1 through September 30, exof natural gas curtailment. 

12100021 Fulton 

OWENS CORNING INSULATING SYSTEMS, LLC 

Operation of a wool fiberglass insulation manufacturing facility 

VOC NOx 

VOC emissions from furnaces, focuring ovens, and cooling sectionaccordance with 40 CFR Part 63 Subpart NNN requirements detersufficient to meet requirements o3-1-.02(2)(tt). VOC emissions from flexographiin accordance with Georgia Rule NOx emissions from glass meltinminimized in accordance with Ge.02(2)(yy) through the use of cuswith a NOx emission limit per fuof NOx per ton of molten glass pNOx emissions from risers, forehoperations, and curing ovens minwith Georgia Rule 391-3-1-.02(2of customized burners and low N

188
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

12100070 Fulton 

MEADWESTVACO PACKAGING SYSTEMS LLC 

Operation of a printed paperboard carton manufacturing plant. 

VOC VOC emissions from storage tank 

accordance with Georgia Rule 39

VOC emissions from flexographiprinting operations minimized in Georgia Rule 391-3-1-.02(2)(mm

04500039 Carroll 

PRINTPACK INC Manufacturing of flexible 

packaging materials 

VOC VOC emissions from flexographi

in accordance with Georgia Rule 

VOC emissions from extrusion lain accordance with Georgia Rule VOC emissions from solvent storin accordance with Georgia Rule VOC emissions from solvent metminimized in accordance with Ge.02(2)(ff). 

12100221 Fulton 

Chattahoochee BP Terminal 

Operation of a bulk gasoline terminal 

VOC Facility-wide VOC emissions mi

accordance with Georgia Rule 39

VOC emissions from internal flominimized in accordance with Ge.02(2)(nn). On internal floating rsubject to 40 CFR Part 60 Subpar

189
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

VOC emissions from external flominimized in accordance with Ge.02(2)(bb). VOC emissions from gasoline loain accordance with Georgia Ruleand (ss). 

12100334 Fulton 

OWENS CORNING ROOFING AND ASPHALT, LLC 

Operation of an asphalt roofing and asphalt processing and storage facility. 

VOC NOx 

VOC emissions from applicable bminimized in accordance with Ge.02(2)(ccc). VOC emissions from applicable sminimized in accordance with Ge.02(2)(vv). NOx emissions from asphalt blowin accordance with Georgia Ruleand (rrr). Georgia Rule (yy) estaemission limit per still of 0.08 poof asphalt charged. Georgia Rule case, annual tune-ups in accordanmanufacturers recommendations 

190
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

natural gas, LPG, or propane duriSeptember of each year. NOx emissions from “small” piecequipment minimized in accordanRule 391-3-1-.02(2)(rrr) – annual accordance with manufacturers rethe burning of natural gas, LPG, May through September of each y

12100020 Fulton 

OWENS-BROCKWAY GLASS CONTAINER INC. 

Operation of a glass container manufacturing plant. 

NOx Subject to Georgia Rule 391-3-1-

emissions from the glass melting than 5.50 lbs per ton of glass prodmelting furnaces are not idling (nthan 25% of production capacity) Furnace E at less than 3.5 lbs/ton 

12100705 Fulton 

SPURLIN INDUSTRIES, INC. 

Operation of a reinforced fiberglass bath products manufacturing facility 

VOC Subject to Georgia Rule 391-3-1-

12100254 Fulton 

PPG ARCHITECTURAL FINISHES, INC. 

Operation of a coating manufacturing facility 

VOC Subject to Georgia Rules 391-3-1

(ccc). 

13900002 Hall 

CARGILL INC.- CARGILL’S GAINESVILLE VEGETABLE OIL MILL 

Operation of a vegetable/soy oil mill and an edible oil refinery. 

VOC Subject to Georgia Rule 391-3-1-

RACT determined to be implemerequirements for all isomers of hegallons of hexane (all isomers) pe

191
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

& REFINERY 

NOx 

processed during any12-month peand recordkeeping requirements oNo reductions of HAP as a result implementation since the facility HAP isomer of hexane in 1998. Applicable storage tanks are subj(vv) for minimization of VOC emSubject to Georgia Rule 391-3-1-emission limit for the coal-fired blb/MMBtu and annual tune-ups freformer, and dryer. 

13900075 Hall 

INDALEX AMERICA INC Operation of an 

aluminum building products manufacturing and coating facility. 

VOC VOC emissions from surface coa

minimized in accordance with Ge.02(2)(ii) and 40 CFR Part 63 Sub

15100025 Henry Stockbridge 

TRANSCONTINENTAL GAS PIPE LINE STA 120 

Operation of a natural gas compressor station 

VOC VOC emissions from IC engines 

accordance with Georgia Rule 39through the use of “Good CombuPractices” which includes fire onstationary engines and turbines. engines must have maintained elecontrollers. Preventative maintenequipment including recordkeepi

192
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

NOx 

maintenance. NOx emissions from IC engines maccordance with Georgia Rule 39with an ozone season limit of 6.0 horsepower-hour. 

21700024 Newton 

PACTIVE CORPCovington Polystyrene Foam Products 

Operation of a polystyrene foam packaging manufacturing facility. 

VOC Subject to Georgia Rule 391-3-1-

21700033 GENERAL MILLS 

OPERATIONS INC 

Operation of a dry cereal manufacturing facility. 

NOx NOx emissions from boiler minim

with Georgia Rule 391-3-1-.02(2

25500047 Spalding 

EXOPACK LLC Operation of a 

polyethylene film production and printing facility. 

VOC VOC emissions from flexographi

in accordance with Georgia Rule 

VOC emissions from chemical stminimized in accordance with Ge.02(2)(vv). 

193
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Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

25500049 Spalding 

COOPER-STANDARD AUTOMOTIVE, INC 

Operation of an extruded rubber gasket and seal manufacturing facility 

VOC Spray coating booth on the plasti

limited to 5.0 pounds of VOC per minus water in accordance with G

All other operations deemed to reVOC control in accordance with 

29700036 Walton Social Circle 

THE GOODYEAR TIRE & RUBBER 

Operation of a rubber tread manufacturing facility 

VOC VOC emissions from banbury mi

finish mills, extruders, tread presminimized in accordance with Ge.02(2)(tt) which in this case was dadditional VOC control. VOC emprocess units also minimized in aCFR Part 63 Subpart XXXX. 

VOC emissions from platen tread 1 and 2 to be minimized in accordRule 391-3-1-.02(2)(tt) which in operation of regenerative thermal minimum VOC removal efficiencVOC emissions from platen tread and 2 to be minimized in accordaRule 391-3-1-.02(2)(tt) which in operation of regenerative thermal 

194
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Table 10-4: Metro Atlanta Permitted Sources whose VOC and/or NOx Emissions Equal or Exceed 100 t

AIRS 

Number 

Georgia 

County 

Name 

Company Name 

Source Description For Which 

Ozone 

Precursor? RACT Determin

minimum VOC removal efficiencVOC emissions from ring tread cbe minimized in accordance with 1-.02(2)(tt) which in this case is tregenerative thermal oxidizer witremoval efficiency of 97.0%. 

29700037 TRANSCONTINENTAL 

GAS PIPE LINE STA 125 

Operation of a natural gas pumping station 

NOx NOx emissions minimized from c

in accordance with Georgia Rule with a NOx limit of 15.2 pounds 

29700040 MPC Generating, LLC Electric utility NOx 

Subject to Georgia Rule 391-3-1-

29700041 DOYLE GENERATING 

FACILITY 

Electric utility NOx Subject to Georgia Rule 391-3-1-

29700042 WALTON COUNTY 

POWER LLC/LG&E Power/Monroe LLC 

Electric utility NOx Subject to Georgia Rule 391-3-1-

195
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196

11.0 INFRASTRUCTURE SIP ELEMENTS 

Section 110(a) of the Clean Air Act (CAA) requires states to submit an implementation 

plan to the U.S. EPA Administrator that provides for implementation, maintenance, and 

enforcement of national ambient air quality standards (NAAQS). Section 110(a)(2) lists 

the elements that are to comprise the implementation plan. Several of the elements in 

§110(a)(2) specifically address the need for states to demonstrate the ability to 

implement, maintain, and enforce the air quality standards. These elements are 

sometimes compiled and submitted separately in what is referred to as an “infrastructure” 

SIP. This document is the Georgia EPD infrastructure SIP for the 1997 ozone NAAQS. 

The elements of §110(a)(2) are listed below. 

• Enforceable Emission Limitations and Other Control Measures [§110(a)(2)(A)] 

• Air Quality Monitoring, Compilation, Data Analysis, and Reporting 

[§110(a)(2)(B)] 

• Enforcement and Stationary Source Permitting [§110(a)(2)(C)] 

• Interstate Transport (§110(a)(2)(D)) 

• Resources, Conflict of Interest, and Emergency Backstop [§110(a)(2)(E)] 

• Stationary Source Emissions Monitoring and Reporting [§110(a)(2)(F)] 

• Emergency Powers and Contingency Plans [§110(a)(2)(G)] 

• SIP Revision for Revised Air Quality Standards or New Attainment Methods 

[§110(a)(2)(H)] 

• SIP Revisions for New Nonattainment Areas [§110(a)(2)(I)] 

• Consultation and Public Notification [§110(a)(2)(J)] 

• Air Quality Modeling and Reporting [§110(a)(2)(K)] 

• Major Stationary Source Permitting Fees [§110(a)(2)(L)] 

• Consultation with Local Entities [§110(a)(2)(M)] 

Most of these elements are addressed in the comprehensive §110(a)(2) SIP submitted by 

the state of Georgia in response to the CAA of 1970 and approved by U.S. EPA as noted 

in 40 CFR Parts 52 Subpart L. This submittal continues to affirm Georgia EPD’s 

commitment to comply with §110(a)(2) requirements and incorporated by reference into 

this submittal. 

The purpose of this document is to examine Georgia’s State Implementation Plan (SIP) 

and determine if all necessary implementation, maintenance, and enforcement measures 

for the 1997 ozone National Ambient Air Quality Standard (NAAQS) are in place. 
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197

GEORGIA’S APPROACH

Section 110(a)(2) of the Clean Air Act Amendments of 1990 provides a detailed listing of 

various requirements for Georgia’s SIP regarding the NAAQS. Below, each 

subparagraph from (A) through (M) is broken down, with various provisions supporting 

the requirements. 

______________________________________________________________________ 

§110(a)(2) of the Clean Air Act (Subparagraphs A-M) 

EPA and Georgia Requirements 

_______________________________________________________________________ 

(A) EPA Requirement:

Include enforceable emission limitations and other control measures, means, or 

techniques (including economic incentives such as fees, marketable permits, and 

auctions of emissions rights), as well as schedules and timetables for compliance. 

Georgia Requirements 

• Georgia Rules for Air Quality 391-3-1-.01 – “Definitions. Amended”’ 

• Georgia Rules for Air Quality 391-3-1-.02 – “Provisions. Amended”; and 

• Georgia Rules for Air Quality 391-3-1-.03 – “Permits. Amended”. 

________________________________________________________________________ 

(B) EPA Requirement – Air Quality Monitoring, Compilation, Data Analysis, 

and Reporting: 

Provide for establishment and operation of devices, methods, systems, and 

procedures to: (i) monitor, compile, and analyze data on ambient air quality, and 

(ii) make such data available to EPA. 

Georgia Requirement:

As early as 1957, the state of Georgia has monitored air pollutants. Prior to the 

CAA of 1970, the state health department conducted air monitoring. In the early 

1970’s the Georgia EPD assumed responsibilities for ambient air monitoring to 

facilitate the identification and control of air contaminants in Georgia. 

Georgia EPD produces an annual ambient monitoring network plan and periodic 

network assessment in accordance with 40 CFR 58.10. The purpose of the annual 

ambient monitoring network plan is two-fold. First, the plan confirms that the 

network continues to meet the State and Local Air Monitoring Stations (SLAMS) 

criteria established by federal regulations, and that the information in the state and 

federal monitoring records properly classify each monitoring station. Second, the 
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198

plan serves as a directory of existing State and Local Air Monitoring Stations 

(SLAMS), Photochemical Assessment Monitoring Stations (PAMS), Speciation 

Trends Network (STN) and Supplemental Speciation sites, National Air Toxics 

Trends Station (NATTS), Special Purpose Monitoring (SPM), Georgia Air Toxics 

Network, Acid Rain sites, and the meteorological parameters performed at each 

location. 

Georgia’s authority to monitor ambient air quality is found in Georgia Air Quality 

Article 1: Air Quality O.C.G.A. Section 12-9, et seq. 

Performance Partnership Agreement (PPA) between EPA and the State of 

Georgia establish the obligation to operate an ambient monitoring network that 

complies with applicable federal regulation(s). 

No specific statutory or regulatory authority is necessary to authorize data 

analysis or the submission of such data to EPA. Federal grant requirements 

establish the obligation to provide data to EPA. 

Georgia has and will continue to submit data to EPA’s Air Quality System. 

________________________________________________________________________ 

(C) EPA Requirement – Enforcement and Stationary Source Permits: 

Include a program to provide for enforcement of measures in (A), and regulation 

of the modification and construction of any stationary source within the areas 

covered by the plan as necessary to assure that NAAQS are achieved, including a 

permit program as required in parts C and D. 

Georgia Requirement - Enforcement: Georgia EPD’s Enforcement Program 

covers mobile and stationary sources, consumer products, and fuels. 

Georgia’s enforcement authority is found in Georgia Air Quality Article 1: Air 

Quality O.C.G.A. Section 12-9, et seq. 

Memorandum of Agreement between Georgia EPD and the U.S. EPA. 

Performance Partnership Agreement. 

Georgia Rule 391-3-1-.07 – “Inspections and Investigations. Amended” 

Georgia Rule 391-3-1-.09 – “Enforcement. Amended” 

Georgia Requirement – Stationary Source Permitting: 

Georgia Air Quality Article 1: Air Quality O.C.G.A. Section 12-9, et seq. 

Georgia Rules for Air Quality 391-3-1-.02. - “Provisions. Amended” including: 
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199

PSD requirements under Georgia Rules for Air Quality 391-3-1-.02(7). 

Georgia Rules for Air Quality 391-3-1-.03. – “Permits. Amended” including: 

NSR requirements under Georgia Rules for Air Quality 391-3-1-.03(8). 

________________________________________________________________________ 

(D) EPA Requirement – Interstate Transport:

(i) Contain adequate provisions prohibiting any source or other type of 

emissions activity from emitting any air pollutant in amounts which 

will: 

(I) contribute significantly to nonattainment in, or interfere with 

maintenance by, any other State with respect to any such national 

primary or secondary ambient air quality standard. 

Georgia Requirement: 

• Permitting requirements under Georgia Rule 391-3-1-.03 and 

Nonattainment New Source Review regulations under Georgia Rule 391-

3-1-.03(8).

• Interstate transport requirements under Georgia Rules 391-3-1-.02(12) and 

391-3-1-.02(13) per the Clean Air Interstate Rule.

EPA Requirement: 

(i) Contain adequate provisions prohibiting any source or other type of 

emissions activity from emitting any air pollutant in amounts which 

will: 

(II) interfere with measures required to be included in the applicable 

implementation plan for any other State under part C to prevent 

significant deterioration of air quality or to protect visibility. 

Georgia Requirement:

• PSD requirements under Georgia Rule for Air Quality 391-3-1-.02(7). 

• Georgia is required to develop and implement a Regional Haze State 

Implementation Plan to protect visibility. In addition, Georgia is 

developing and implementing a PM2.5 SIP that will assist with reducing 

visibility-reducing pollutants. 
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200

EPA Requirement:

(ii) Insure compliance with the applicable requirements of sections 126 and 

115 of the Clean Air Act (interstate and international pollution abatement). 

Georgia Requirement:

• Georgia Air Quality Article 1: Air Quality O.C.G.A. Section 12-9, et seq. 

• PSD regulation under Georgia Rule for Air Quality 391-3-1-.02(7). 

• Permitting regulations under Georgia Rule for Air Quality 391-3-1-.03. 

• In addition, nothing in Georgia’s statutory or regulatory authority 

prohibits or otherwise interferes with Georgia’s ability to exercise 

sections 126 and 115 of the CAA.

________________________________________________________________________ 

(E) EPA Requirement – Resources, Conflict of Interest, and Emergency Backstop: 

Provide: 

(i) necessary assurances that the State will have adequate personnel, 

funding, and authority under State law to carry out such 

implementation plan (and is not prohibited by any provision of Federal 

or State law from carrying out such plan). 

Georgia Requirement:

• This is accomplished through the CAA section 105 grant process , Georgia 

Air Quality Act Article 1: Air Quality O.C.G.A. 12-9-10, and Georgia 

Rule for Air Quality 391-3-1-.03(9) [Georgia Air Permit Fee System]. 

EPA Requirement:

(ii) Requirements that the State comply with the requirements respecting State 

boards under section 128 of the Clean Air Act. 

Georgia Requirement: 

• Georgia’s authority is found in Georgia Air Quality Article 1: Air Quality 

O.C.G.A. Section 12-9, et seq. 
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EPA Requirement:

(iii) Necessary assurance that, where the State has relied on a local or regional 

government, agency, or instrumentality for the implementation of any plan 

provision, the State has responsibility for ensuring adequate of 

implementation of such plan provision. 

Georgia Requirement:

• Georgia does not rely on localities for specific SIP implementation. 

______________________________________________________________________ 

(F) EPA Requirement – Stationary Source Emissions Monitoring and Reporting:

Require, as may be prescribed by EPA: 

(i) installation, maintenance, and replacement of equipment, and 

implementation of other necessary steps, by owners or operators of 

stationary sources to monitor emissions. 

(ii) Periodic reports on the nature and amounts of emissions and emissionsrelated data. 

(iii) Correlation of such reports by the State agency with any emission 

limitations or standards established pursuant to CAA, which reports shall 

be available at reasonable times for public inspection. 

Georgia Requirement: 40 CFR Part 51.214 requires every SIP to include 

requirements for the monitoring of emissions from major stationary sources as 

specified in 40 CFR Part 51 Appendix P. Georgia EPD has adopted regulations to 

implement these requirements. 

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Georgia Rule for Air Quality 391-3-1-.02(3) – “Sampling”. 

• Georgia Rule for Air Quality 391-3-1-.02(6) – “Source Monitoring”. 

• Georgia Rule for Air Quality 391-3-1-.02(11) – “Compliance Assurance 

Monitoring.” 

• Georgia Rule for Air Quality 391-3-1-.03 – “Permits. Amended”. 

______________________________________________________________________ 
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202

(G) EPA Requirement – Emergency Powers and Contingency Plans:

Provide for authority comparable to that in §303 and adequate contingency plans 

to implement such authority. Section 303 provides legal authority to the U.S. 

EPA to halt the emission of air pollutants causing or contributing to injury to 

public or welfare. U.S. EPA is authorized to either bring a lawsuit in federal court 

or, if such civil action cannot assure prompt protection of public health or welfare, 

to issue such orders as may be necessary to protect public health or welfare or the 

environment. 

The requirement for states to provide adequate contingency plans to implement 

such authority is intended to establish emergency episode plans for responding to 

elevated pollutant levels in urban areas. Emergency episode plans are required in 

areas that record ambient pollutant concentrations in excess of threshold levels 

specified in 40 CFR Part 51.150. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Georgia Rule for Air Quality 391-3-1-.04 – “Air Pollution Episodes.” 

• January 1972 SIP: “Implementation Plan for Attainment of State and 

National Ambient Air Standards” – Air Quality Control Branch, Georgia 

Department of Public Health (primary pages are 169-266). 

_____________________________________________________________________ 

(H) EPA Requirement – SIP Revisions for Revised Air Quality Standards or New 

Attainment Methods: 

Provide for revision of such plan: 

(i) from time to time as necessary to take account of revisions of such 

national primary or secondary ambient air quality standard or the 

availability of improved or more expeditious methods of attaining such 

standard. 

(ii) except as provided in (3)(C), whenever EPA finds on the basis of 

information available to EPA that the plan is substantially inadequate 

to attain the NAAQS which it implements or to otherwise comply with 

any additional CAA requirements. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 
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• Performance Partnership Agreement 

• Georgia EPD commits to submit SIP revisions whenever revised air 

quality standards are promulgated by U.S. EPA. 

____________________________________________________________________ 

(I) EPA Requirement – SIP Revisions for New Nonattainment Areas:

In the case of a plan or plan revision for an area designated as a nonattainment 

area, meet the applicable requirements of part D (relating to nonattainment areas). 

States are to submit SIP revisions for newly designated nonattainment areas to 

meet the requirements of Part D – Plan Requirements for Nonattainment Areas 

under Clean Air Act Title I – Air Pollution Prevention and Control. Part D of the 

Clean Air Act specifies both general requirements for all SIPs and specific 

requirements for different criteria pollutants. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Georgia Rule for Air Quality 391-3-1-.02 – “Provisions. Amended” 

• Georgia Rule for Air Quality 391-3-1-.03 – “Permits. Amended” 

• Georgia EPD commits to submit SIP revisions whenever areas of the state 

are newly designated nonattainment for any federal ambient air quality 

standard. 

___________________________________________________________________ 

(J) EPA Requirement – Consultation and Public Notification:

Meet applicable requirements of §121 (consultation). Section 121 requires that 

states provide a satisfactory process of consultation with general purpose local 

governments, designated organizations of elected officials of local governments, 

and any affected federal land manager in carrying out CAA requirements. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Georgia Administrative Procedures Act (O.C.G.A. §50-13-4) 

• Georgia Rule 391-3-1-.02(7) as it relates to Class I areas. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

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• Transportation Conformity SIP Revision dated April 7, 2000 and approved 

in 65 FR 18245. This SIP takes the form of a Memorandum of Agreement 

(MOA) between the agencies involved including but not limited to the 

Atlanta Regional Commission, Georgia Department of Transportation, the 

Metropolitan Atlanta Rapid Transit Authority, and Georgia EPD. 

• Ozone SIP contains equivalent consultation and participation for PM2.5 

requirements. 

• Georgia EPD commits to maintaining a process of consultation with 

parties designated under Section 121. 

EPA Requirement:

Meet applicable requirements of §127 (public notification). Section 127 requires 

the states to provide measures which will be effective to notify the public on a 

regular basis of instances or areas in which any air quality standard is exceeded 

during the preceding calendar year, to advise the public of the health hazards 

associated with such pollution, and to enhance public awareness of measures that 

can be taken to prevent such standards from being exceeded. 

• Georgia EPD forecasts daily ozone and particle levels and issues e-mails 

to the public, businesses and the media. 

• Daily air quality forecasts may be disseminated to the public in Atlanta via 

electronic Georgia DOT billboards. 

• Non-profit organization “Clean Air Campaign” disseminates statewide air 

quality information as well as ways to reduce air pollution. 

• In addition, air quality calendars display past air quality information and 

dynamic graphs provide summaries of unhealthy air quality experienced 

throughout the region. This feature of the web site allows the public to 

monitor long term air quality and see how one year compares to previous 

years. 

• Georgia EPD commits to maintaining a public information and education 

program that satisfies the requirements of Section 127. 

EPA Requirement:

Meet applicable requirements of Part C (PSD and visibility protection). 

Georgia Requirement: 

• Georgia Rule for Air Quality 391-3-1-.02(1) – “General Requirements”. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

205

• Georgia Rule for Air Quality 391-3-1-.02(7) – “Prevention of Significant 

Deterioration”. 

• Georgia EPD intends to comply with the recently promulgated NSR rules 

for PM2.5. Per that rule, for PSD, Georgia EPD has up to 3 years to 

incorporate such changes, until which time Georgia EPD uses PM10 as a 

surrogate. For Nonattainment NSR, the federal rule requires that Georgia 

EPD use PM2.5 effective July 15, 2008 under the authority of 40 CFR 

Part 51 Appendix S. The federal rule does not allow the use of PM10 as a 

surrogate for PM2.5 in nonattainment NSR after July 15, 2008. 

___________________________________________________________________ 

(K) EPA Requirement – Air Quality Modeling and Reporting:

(i) Provide for performance of air quality modeling as EPA may prescribe for 

the purpose of predicting the effect on ambient air quality of any 

emissions of any air pollutant for which EPA has established a NAAQS. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Inherent in the obligation to meet the NAAQS is the authority for Georgia 

EPD to perform modeling as required under the CAA to demonstrate 

attainment. 

EPA Requirement:

(ii) Provide for the submission, upon request, of data related to such air 

quality modeling to EPA. 

Georgia Requirement: 

• Air quality modeling data is submitted as part of Georgia’s relevant SIP 

submissions and through federal grant commitments. 

______________________________________________________________ 

(L) EPA Requirement – Major Stationary Source Permitting Fees:

Require owner of a major stationary source to pay, as a condition of any permit 

required under CAA, a fee sufficient to cover: (i) reasonable cost of reviewing 

and acting upon any permit application, and (ii) if the owner receives a permit, the 

reasonable costs of implementing and enforcing the terms and conditions of the 

permit (not including court costs or costs associated with enforcement), until fee 

requirement is superseded by EPA approval of a Title V fee program. 
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Georgia Requirement:

• Georgia Rule for Air Quality 391-3-1-.03(9) – “Permit Fees.” 

• Calendar year 2002 was submitted as a SIP revision on June 25, 2003 – 

appears to be SIP approved. 

• Calendar years 2003, 2004, and 2005 were submitted as part of one SIP 

submittal in July 2006. 

• Calendar year 2006 was submitted as a SIP revision on August 22, 2007. 

• Georgia EPD commits to implementing a permit fee system in accordance 

with section 110(a)(2)(M) of the Clean Air Act. 

______________________________________________________________ 

(M) EPA Requirement – Consultation with Local Entities:

Provide for consultation and participation by local political subdivisions 

affected by the plan. 

Georgia Requirement:

• The Georgia Air Quality Act: Article I: Air Quality (O.C.G.A. Section 

12-9, et. Seq.) 

• Transportation Conformity SIP Revision dated April 7, 2000 and approved 

in 65 FR 18245. This SIP takes the form of a Memorandum of Agreement 

(MOA) between the agencies involved including but not limited to the 

Atlanta Regional Commission, Georgia Department of Transportation, the 

Metropolitan Atlanta Rapid Transit Authority, and Georgia EPD. 

• Ozone SIP contains equivalent consultation and participation for the 1997 

ozone standard. 

______________________________________________________________ 
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Wegman, Director, Air Quality Strategies & Standards. August 2004. 

US EPA, OAQPS. 1995. Memorandum. Fifteen Percent rate-of-Progress Plans – 

Additional Guidance. J.S. Seitz, Director. May 5. 

US EPA, OAQPS. Memorandum. Incorporating Voluntary Stationary Source Emission 

Reduction Programs Into State Implementation Plans – FINAL POLICY. J.S. Seitz, 

Director. (no date) 

US EPA, OAQPS. 2006. Memorandum. Supporting Innovative Strategies to Keep 

Communities' Air Clean 8-Hour Ozone Flex (8-O3 Flex) Program. S.D. Page, Director. 

May 18. 

US EPA. AQPD. 2006. Note. RACT Qs & As – Reasonably Available Control 

Technology Questions and Answers. W.T. Harnett, Director. May 18. 

US EPA. 2006. Memorandum. To Dr. G. Gray, Assistant Administrator, ORD, Bill 

Wehrum, Acting Assistant Administrator, OAR. Process for Reviewing National 

Ambient Air Quality Standards. M. Peacock Deputy Administrator. December 7. 

US EPA. OAQPS and OTAQ. 2006. Memorandum. Removal of Stage II Vapor 

Recovery in Situations Where Widespread Use of Onboard Refueling Vapor Recovery is 

Demonstrated. S.D. Page, Director, OAQPS and M.T. Oge, Director, OTAQ. December 

12. 

US EPA. OAR. 2004. Incorporating Emerging and Voluntary Measures in a State 

Implementation Plan. September. 

US EPA. OAP and OAQPS. 2004. Memorandum. Guidance on SIP Credits for Emission 

Reductions from Electric-Sector Energy Efficiency and Renewable Energy Measures. B. 

McLean, Director, OAP, and S. Page, Director, OAQPS. August. 

National Resources Defense Council. Flying Off Course Environmental Impacts of 

America's Airports, October 1996. 

US EPA. OAQPS. 2008. Presentation. March 2008 Final National Ambient Air Quality 

Standards for Ground-level Ozone, General Overview. 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix A 

County-Level Emission Summary 

Tables for Georgia 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix B 

Observed and Modeled Spatial 

Distribution of Daily 8-Hour 

Maximum Ozone
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix C 

Daily Maximum 8-Hour Ozone, 1-

Hour Ozone, NO, and NO2 Barplots 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix D 

Scatter Plots of Hourly 8-Hour Ozone, 

1-Hour Ozone, NO, and NO2 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix E 

Time Series Plots of Hourly 8-Hour 

Ozone, 1-Hour Ozone, and Precursor 

Species 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix F 

Sensitivity of Ozone in Atlanta to 

Reductions in NOx and VOC 

Emissions 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix G 

Clean Air Markets - EGU NOx Data 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix H 

Sensitivity of Ozone in Macon to 

Reductions in NOx Emissions from 

Various Sources in Georgia 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix I 

Protocol for Annual MM5 Modeling in 

Support of VISTAS 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix J 

MM5 2002 Modeling in Support of 

VISTAS 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix K 

Documentation of VISTAS Inventories 

and Georgia 2002 CERR Inventory
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix L 

Guidance on the Use of Models and 

Other Analysis for Demonstrating 

Attainment of Air Quality Goals for 

Ozone, PM2.5, and Regional Haze
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix M 

Georgia Environmental Protection 

Division Comments on: 

"Guidance on the Use of Models and 

Other Analyses for Demonstrating 

Attainment of Air Quality Goals for 

Ozone, PM2.5 and Regional Haze" 

October 27, 2006 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix N 

Modeling Protocol for the Atlanta, GA 

8-hour Ozone Nonattainment Area 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix O 

VISTAS CEM Emission Rate Memo 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix P 

Quality Assurance Project Plan 

(Draft) for Association for 

Southeastern Integrated Planning 

(ASIP) Emissions and Air Quality 

Modeling to Address 8-Hour Ozone 

and PM2.5 Nonattainment in 

Southeastern States
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix Q 

Hartsfield-Jackson Atlanta 

International Airport 

Reduction in Emissions of Ozone 

Precursors 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix R 

MM5 Meteorological Model 

Performance Evaluation
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix S 

May 11, 2006, Letter to EPA 

Requesting Concurrence on I/M 

Applicability 

May 31, 2006, Letter from EPA 

Concurring 
The Atlanta Eight-Hour Ozone Attainment Demonstration 

Appendix T 

Voluntary Reduction of Emissions 

from Railyards in 

 Metro Atlanta Region
Appendix U 

Mobile Source Emissions Modeling 

for Atlanta 

Ozone Attainment Demonstration 

Motor Vehicle Emissions Budgets