1

Atlanta, Georgia

Area Designations for the 

2008 Ozone National Ambient Air Quality Standards

The table below identifies the counties in Georgia that EPA is designating as “nonattainment” for the 

2008 ozone national ambient air quality standards (2008 ozone NAAQS) as part of the Atlanta, Georgia 

area. In accordance with section 107(d) of the Clean Air Act, EPA must designate an area 

“nonattainment” if it is violating the 2008 ozone NAAQS or if it is contributing to a violation of the 

2008 ozone NAAQS in a nearby area. The technical analysis supporting the boundary for this

nonattainment area is provided below.

Table 1: Final Nonattainment Area for the Atlanta, GA Area

Area 

Georgia’s Recommended 

Nonattainment Counties EPA’s Nonattainment Counties

Atlanta, GA Cobb

DeKalb

Fulton

Henry

Bartow

Cherokee

Clayton

Cobb

Coweta

DeKalb

Douglas

Fayette

Forsyth

Fulton

Gwinnett

Henry

Newton

Paulding 

Rockdale

EPA is designating the remaining counties in Georgia that are not listed in the table above as 

“unclassifiable/attainment” for the 2008 ozone NAAQS. 

The analysis below provides the basis for the Atlanta nonattainment area boundary. It relies on EPA’s

analysis of whether and which monitors are violating the 2008 ozone NAAQS, based on certified air 

quality monitoring data from 2009-2011, and an evaluation of whether nearby areas are contributing to 

such violations. EPA has evaluated contributions from nearby areas based on a weight of evidence 

analysis considering the factors identified below. EPA issued guidance on December 4, 2008 that 

identified these factors as ones EPA would consider in determining nonattainment area boundaries and 

recommended that states consider these factors in making their designations recommendations to EPA.1

 

1. Air quality data (including the design value calculated for each Federal Reference Method or 

Federal Equivalent Method (FEM) monitors in the area); See 40 CFR part 58

2. Emissions and emissions-related data (including location of sources and population, amount of 

emissions and emissions controls, and urban growth patterns);

 1 The December 4, 2008, guidance memorandum “Area Designations for the 2008 Revised Ozone National Ambient Air 

Quality Standards” refers to 9 factors. In this technical support document we have grouped the emissions-related factors 

together under the heading of “Emissions and Emissions-Related Data,” which results in 5 categories of factors.
2

3. Meteorology (weather/transport patterns);

4. Geography and topography (mountain ranges or other basin boundaries);

5. Jurisdictional boundaries (e.g., counties, air districts, existing nonattainment areas, Indian 

country, metropolitan planning organizations (MPOs))

Ground-level ozone generally is not emitted directly into the air, but is created by chemical reactions 

between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. 

Because NOx and VOC emissions from a broad range of sources over a wide area typically contribute to 

violations of the ozone NAAQS, EPA believes it is important to consider whether there are contributing 

emissions from a broad geographic area. Accordingly, EPA chose to examine the 5 factors with respect 

to the larger of the Combined Statistical Area (CSA) or Core Based Statistical Area (CBSA) associated 

with the violating monitor(s).

2 All data and information used by EPA in this evaluation are the latest

available to EPA.

In EPA’s designations guidance for the 2008 ozone NAAQS, EPA recommended examining 

CSA/CBSAs because certain factors used to establish CSAs and CBSAs are similar to the factors EPA is 

using in this technical analysis to determine if a nearby area is contributing to a violation of the 2008 

ozone NAAQS. Congress required a similar approach in 1990 for areas classified as serious or above 

for the 1-hour ozone NAAQS and EPA used the same basic approach in the designation process for the 

1997 ozone NAAQS. Where a violating monitor is not located in a CSA or CBSA, EPA’s guidance 

recommended using the boundary of the county containing the violating monitor as the starting point for 

considering the nonattainment area’s boundary. 

 2 Lists of CBSAs and CSAs and their geographic components are provided at 

www.census.gov/population/www/metroareas/metrodef.html . The lists are periodically updated by the Office of 

Management and Budget. EPA used the most recent update, based on 2008 population estimates, issued on December 1, 

2009 (OMB Bulletin No. 10-02).
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Technical Analysis for Atlanta, GA

Figure 1 is a map of the Atlanta, GA nonattainment area. The map identifies the locations and design 

values of air quality monitors, county and other jurisdictional boundaries, the nonattainment boundary 

for the 1997 8-hour ozone NAAQS and major transportation arteries.

For purposes of the 1997 8-hour ozone NAAQS, EPA designated the following 20 counties

nonattainment in their entirety: Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, 

Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and 

Walton.

In March 2009, Georgia recommended that the 20 counties previously designated nonattainment for the 

1997 8-hour ozone NAAQS and a portion of Heard County be designated as “nonattainment” for the 

2008 ozone NAAQS based on air quality data from 2006-2008. Georgia provided an update to the 

original recommendation in October 2011 based on preliminary air quality data from 2009-2011. In its 

updated recommendation, Georgia recommended that only 4 counties (i.e., Cobb, DeKalb, Fulton and 

Henry) be designated “nonattainment” for the 2008 ozone NAAQS. These data are from FEM monitors 

sited and operated in accordance with 40 CFR Part 58. (Georgia Department of Natural Resources 

(GDNR) letters dated March 12, 2009, and October 25, 2011).
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On December 9, 2011, EPA initiated the 120 day consultation process by notifying Georgia that based 

on EPA’s technical analysis of the 33-county Atlanta-Sandy Springs-Gainesville CSA, EPA intended to 

designate 18 counties in Georgia (identified in Table 2 below) as “nonattainment” for the 2008 ozone 

NAAQS as part of the Atlanta, GA nonattainment area. In this December 2011 letter, EPA also 

requested that if the Georgia wished to provide additional information on EPA’s intended designation or 

to use early certified 2011 monitoring data for designation, they should provide comments or early 

certify by February 29, 2012. 

Table 2. State's Recommended and EPA’s Intended Designated Nonattainment Counties for the Atlanta,

GA from December 9, 2011.

Atlanta, GA State-Recommended 

Nonattainment Counties

EPA Intended Nonattainment 

Counties*

Georgia Cobb

DeKalb

Fulton

Henry

Barrow

Bartow

Cherokee

Clayton

Cobb

Coweta

DeKalb

Douglas

Fayette

Forsyth

Fulton

Gwinnett

Henry

Newton

Paulding 

Rockdale

Spalding

Walton

*bold italics represent counties that were not included in the final boundary for nonattainment area. 

On February 29, 2012, Georgia provided an update to their October 2011 recommendation. This update 

was based on certified air quality data from 2009-2011, and was provided in response to EPA’s 

preliminary boundary determination for the Atlanta-Sandy Springs-Gainesville CSA. After considering 

Georgia’s recommendation and additional technical information, and based on EPA's reevaluation of the 

18 counties as described below, EPA is designating 15 counties in Georgia as “nonattainment” for the 

2008 ozone NAAQS as part of the Atlanta, GA nonattainment area.

EPA originally started with the CSA or CBSA areas for evaluating what areas violate and contribute to 

violations of the ozone NAAQS, and for final determinations refined its evaluation based on additional 

technical information provided by the states and tribes. After considering the recommendations and 

additional technical information for the Atlanta, GA Area, and based on EPA's reevaluation of the 18 

counties as described below, EPA is designating 15 counties as “nonattainment” for the 2008 ozone 

NAAQS as part of the Atlanta, GA nonattainment area. 
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Factor Assessment

Factor 1: Air Quality Data 

For this factor, EPA considered 8-hour ozone design values (in parts per billion (ppb)) for air quality 

monitors in counties in the Atlanta-Sandy Springs-Gainesville CSA, based on data for the 2009-2011

period (i.e., the 2011 design value), which are the most recent years with fully-certified air quality data.

It should be noted that for EPA’s December 9, 2011, technical analysis EPA only had certified 

monitoring data for the 2008-2010 period for the Atlanta-Sandy Springs-Gainesville CSA to consider. 

The 2008-2010 monitor data indicated one additional violating monitor which EPA considered for the 

development of the preliminary boundary determination for the Atlanta, GA nonattainment area. 

A monitor’s design value is the metric or statistic that indicates whether that monitor attains a specified 

air quality standard. The 2008 ozone NAAQS are met at a monitor when the annual fourth-highest daily 

maximum 8-hour average concentration, averaged over 3 years is 75 ppb or less. A design value is only 

valid if minimum data completeness criteria are met. See 40 CFR part 50 Appendix P. Where several 

monitors are located in a county (or a designated nonattainment area or maintenance area), the design 

value for the county or area is determined by the monitor with the highest level.

The 2011 design values for the ozone NAAQS for counties with monitors in the Atlanta-Sandy SpringsGainesville CSA are shown in Table 3. (Counties not identified do not have monitors)

Table 3. Air Quality Data.

County* State Recommended 

Nonattainment?

2009-2011 Design Value 

(ppb)

Cobb, GA Yes 78

Coweta, GA No 67

DeKalb, GA Yes 77

Douglas, GA No 74

Fulton, GA Yes 80

Gwinnett, GA No 75

Henry, GA Yes 78

Paulding, GA No 71

Rockdale, GA No 75

*Counties with violating monitors are shown in bold.

Based on 2009-2011 monitoring data, Cobb, DeKalb, Fulton and Henry Counties show a violation of the 

2008 ozone NAAQS, therefore these counties are included in the Atlanta, GA nonattainment area. 

Rockdale County showed a violation based on 2008-2010 monitoring data with a design value of 78 

ppb, however, as indicated in Table 3 above the Rockdale County monitoring is attaining the 2008 8-

hour ozone NAAQS at a design value of 75 based on more recent 2009-2011 data. 

A county (or partial county) must also be designated nonattainment if it contributes to a violation in a 

nearby area. Each county without a violating monitor that is located near a county with a violating

monitor has been evaluated, as discussed below, based on the five factors to determine whether it 

contributes to the nearby violation. EPA started with the CSA or CBSA for evaluating what areas 

violate and contribute to violations of the ozone NAAQS. 
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Factor 2: Emissions and Emissions-Related Data

EPA evaluated emissions of ozone precursors (i.e, NOx and VOC emissions), and other emissionsrelated data that provide information on areas contributing to violating monitors.

Emissions Data

EPA evaluated county-level emission data for NOx and VOC derived from the 2008 National Emissions 

Inventory (NEI), version 1.5. This is the most recently available NEI. (See 

http://www.epa.gov/ttn/chief/net/2008inventory.html). Significant emissions levels in a nearby area 

indicate the potential for the area to contribute to observed violations. EPA also considered any 

additional information we received on changes to emissions levels that are not reflected in recent 

inventories. 

As mentioned above, EPA received additional information from the State of Georgia for the preliminary 

boundary determination for the Atlanta, GA nonattainment area, and this information was considered for 

this final designations. While additional information was provided for meteorological data (and is 

discussed below), Georgia did not provide any additional emissions-related data for EPA to consider. 

Georgia noted in its supplemental information that the State used the same data source for emissionsrelated information but that the State took a slightly different approach for use of this information. In 

summary, in addition to the factors that EPA identified that the Agency would use to make boundary 

determination, Georgia also considered: (1) NOx and VOC emission density (tons/mile2

); and (2) 

county percent contribution to the total CSA. 

The precursor emission source-category percentages used below and throughout the document were 

derived from emissions data from the 2008 NEI version 1.5 referenced above. Table 4 shows emissions 

of NOx and VOC (given in tons per year (tpy)) for Atlanta-Sandy Springs-Gainesville, GA-AL CSA

that EPA considered for inclusion in the Atlanta, GA nonattainment area. 

Table 4. Total 2008 NOx and VOC Emissions.

County* State Recommended

Nonattainment? NOx (tpy) VOC (tpy)

Barrow No 1,765 2,291

Bartow No 31,560 6,165

Butts No 1,231 1,200

Carroll No 3,757 4,617

Chambers, AL No 1,408 1,644

Cherokee No 4,908 6,189

Clayton No 16,105 9,528

Cobb Yes 20,874 22,494

Coweta No 15,852 3,723

Dawson No 626 1,058

DeKalb Yes 17,356 22,937

Douglas No 3,368 3,968

Fayette No 2,732 3,556

Forsyth No 3,823 5,753

Fulton Yes 28,630 31,707

Gwinnett No 18,569 24,506
7

Hall No 5,756 8,815

Haralson No 1,116 2,118

Heard No 15,093 1,177

Henry Yes 7,584 6,015

Jasper No 526 850

Lamar No 656 858

Meriwether No 1,481 1,369

Newton No 3,307 4,248

Paulding No 2,780 3,037

Pickens No 888 1,366

Pike No 412 661

Polk No 1,429 2,279

Rockdale No 2,483 2,961

Spalding No 1,828 2,862

Troup No 2,966 4,232

Upson No 926 1,897

Walton No 2,245 3,137

Areawide: 224,040 199,218

*Counties that EPA intends to designate as nonattainment are shown in bold.

NOx Emissions: Bartow, Clayton, Cobb, Coweta, DeKalb, Fulton, Gwinnett and Heard Counties each

have over 15,000 tons of NOx emissions annually. Bartow, Clayton, Coweta and Heard Counties have 

over 60 percent of NOx emissions coming from point sources, however, it should be noted that the 

majority of NOx emissions in Clayton County are from Hartsfield-Jackson Atlanta International Airport.

Barrow, Carroll, Cherokee, Douglas, Fayette, Forsyth, Hall, Henry, Newton, Paulding, Rockdale, 

Spalding, Troup, and Walton Counties each have between 1,700 and 8,000 tons of NOx emissions 

annually. 

Barrow, Butts, Carroll, Chambers, Cherokee, Cobb, DeKalb, Douglas, Fayette, Forsyth, Fulton, 

Gwinnett, Hall, Haralson, Henry, Jasper, Lamar, Meriwether, Newton, Paulding, Pickens, Pike, Polk,

Rockdale, Spalding, Troup, Upson and Walton Counties have over 30 percent of NOx emissions from

mobile sources. 

VOC Emissions: Cobb, DeKalb, Fulton and Gwinnett Counties each have over 20,000 tons of VOC 

emissions annually. Barrow, Bartow, Butts, Carroll, Cherokee, Clayton, Cobb, Coweta, Dawson, 

DeKalb, Douglas, Fayette, Fulton, Gwinnett, Hall, Henry, Lamar, Meriwether, Newton, Paulding, 

Pickens, Pike, Rockdale, Spalding, Troup, and Walton Counties have over 30 percent of VOC emissions 

from mobile sources. 

Barrow, Bartow, Butts, Carroll, Chambers, Cherokee, Clayton, Cobb, Coweta, Dawson, DeKalb, 

Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hall, Haralson, Henry, Jasper, Lamar, Meriwether, 

Newton, Paulding, Pickens, Pike, Polk, Rockdale, Spalding, Troup, Upson and Walton Counties have 

over 30 percent of VOC emissions from area sources. 
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Population density and degree of urbanization

EPA evaluated the population and vehicle use characteristics and trends of the area as indicators of the 

probable location and magnitude of non-point source emissions. These include ozone precursor

emissions from on-road and off-road vehicles and engines, consumer products, residential fuel 

combustion, and consumer services. Areas of dense population or commercial development are an 

indicator of area source and mobile source NOx and VOC emissions that may contribute to counties 

with violating monitors. Rapid population or vehicle miles travelled (VMT) growth (see below) in a 

county on the urban perimeter signifies increasing integration with the core urban area, and indicates 

that it may be appropriate to include the area associated with the area source and mobile source 

emissions as part of the nonattainment area. Table 5 shows the population, population density, and 

population growth information for each county in the Area.

Table 5. Population and Growth.

County*

State 

Recommended 

Nonattainment?

2010 Population

2010 Population 

Density

(people/sq mi)

Absolute change

in population

(2000-2010)

Population % 

change

(2000-2010)

Barrow No 69,367 426 22,806 49

Bartow No 100,157 213 23,456 31

Butts No 23,655 125 3,926 20

Carroll No 110,527 219 22,526 26

Chambers, AL No 34,215 57 -2,347 -6

Cherokee No 214,346 493 70,603 49

Clayton No 259,424 1,797 21,056 9

Cobb Yes 688,078 1,996 75,436 12

Coweta No 127,317 285 37,168 41

Dawson No 22,330 104 6,031 37

DeKalb Yes 691,893 2,546 23,078 3

Douglas No 132,403 661 39,700 43

Fayette No 106,567 536 14,494 16

Forsyth No 175,511 709 75,013 75

Fulton Yes 920,581 1,721 103,429 13

Gwinnett No 805,321 1,844 208,978 35

Hall No 179,684 419 38,805 28

Haralson No 28,780 102 2,947 11

Heard No 11,834 39 749 7

Henry Yes 203,922 627 82,342 68

Jasper No 13,900 37 2,413 21

Lamar No 18,317 99 2,347 15

Meriwether No 21,992 43 -535 -2

Newton No 99,958 358 37,074 59

Paulding No 142,324 452 59,329 71

Pickens No 29,431 127 6,072 26

Pike No 17,869 81 4,071 30

Polk No 41,475 133 3,226 8

Rockdale No 85,215 645 14,657 21

Spalding No 64,073 320 5,591 10

Troup No 67,044 150 8,121 14
9

Upson No 27,153 83 -462 -2

Walton No 83,768 254 22,207 36

Areawide: 5,618,431 Average 536

*Counties that EPA intends to designate as nonattainment are shown in bold.

Sources: U.S. Census Bureau population estimates for 2010 as of August 4, 2011 

(http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=DEC_10_PL_GCTPL2.ST05&

prodType=table%20as%20of%208/4/11%20and%20estimation%20of%20the%20area%20of%20U.S.%20Countie

s%20based%20on%20County%20Land%20Area%20(line%2019)).

Cobb, DeKalb, Fulton and Gwinnett Counties are the most populated with each county having over 

650,000 people and a population density of over 1,700 people per square mile. Bartow, Carroll, 

Cherokee, Clayton, Coweta, Douglas, Fayette, Forsyth, Hall, Henry and Paulding Counties have over a 

100,000 population. Barrow, Cherokee, Douglas, Fayette, Forsyth, Hall, Henry, Newton, Paulding, 

Rockdale and Spalding Counties have between 300 and 750 people per square mile. 

Gwinnett County had a population growth over 200,000 people between 2000 and 2010. Cherokee, 

Cobb, Forsyth, Fulton, Henry and Paulding Counties had growth in population of over 59,000 people

between 2000 and 2010. 

Forsyth, Henry, Newton and Paulding Counties had a population growth rate over 50 percent between 

2000 and 2010. Barrow, Cherokee, Coweta, Dawson, Douglas, Gwinnett and Walton Counties had a 

population growth rate over 30 percent between 2000 and 2010.

Traffic VMT data and commuting patterns

EPA evaluated the commuting patterns of residents in the area, as well as the total VMT for each 

county. In combination with the population/population density data and the location of main 

transportation arteries (see above), this information helps identify the probable location of non-point 

source emissions. A county with high VMT and/or a high number of commuters is generally an integral 

part of an urban area and indicates the presence of motor vehicle emissions that may contribute to ozone 

formation that contributes to nonattainment in the area. Rapid population or VMT growth in a county on 

the urban perimeter signifies increasing integration with the core urban area, and indicates that the 

associated area source and mobile source emissions may be appropriate to include in the nonattainment 

area. Table 6 shows total 2008 VMT and number of county workers for each county in the area.
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Table 6. Traffic and Commuting Patterns.

County

State 

Recommended 

Nonattainment?

2008 Annual 

VMT*

(million miles)

Number of County 

Workers** (2009 

data)

Percent of County 

Workers that Work in 

Counties with 

Violating Monitors**

Barrow No 552 27,984 18.45%

Bartow No 1,663 40,442 32.13%

Butts No 302 8,600 29.3%

Carroll No 1,117 44,866 26.4%

Chambers, AL No 419 13,683 NA

Cherokee No 1,813 90,016 54.11%

Clayton No 2,600 102,824 50.99%

Cobb Yes 6,601 299,994 76.70%

Coweta No 1,297 49,840 29.66%

Dawson No 190 8,651 26.4%

DeKalb Yes 7,410 284,581 73.95%

Douglas No 1,520 51,578 52.33%

Fayette No 1,028 48,773 34.91%

Forsyth No 1,310 66,136 42.94%

Fulton Yes 11,414 365,927 75.01%

Gwinnett No 7,064 313,622 41.30%

Hall No 1,507 66,551 13.9%

Haralson No 339 10,279 18.0%

Heard No 105 4,254 13.2%

Henry Yes 2,153 80,649 57.91%

Jasper No 129 4,299 9.3%

Lamar No 232 6,794 16.7%

Meriwether No 290 8,316 14.5%

Newton No 1,021 37,693 35.43%

Paulding No 1,112 56,066 56.97%

Pickens No 297 12,295 27.2%

Pike No 145 6,355 14.8%

Polk No 365 15,875 16.9%

Rockdale No 960 34,865 44.18%

Spalding No 588 26,889 30.16%

Troup No 879 26,708 10.0%

Upson No 252 11,742 11.9%

Walton No 720 33,112 21.93%

Areawide 57,394 2,260,259

*MOBILE model VMTs are those inputs into the NEI version 1.5. 

**Source: U.S. Census Bureau http://onthemap.ces.census.gov/

Cherokee, Clayton, Douglas and Paulding Counties have over 50 percent of work force working in 

counties with violating monitors. Bartow, Fayette, Forsyth, Gwinnett and Rockdale have over 30 

percent of work force working in counties with violating monitors.
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Cobb, DeKalb and Fulton Counties had over six billion annual VMT in 2008. Bartow, Carroll, 

Cherokee, Clayton, Coweta, Douglas, Fayette, Forsyth, Gwinnett, Hall, Henry, Newton and Paulding 

Counties had over a billion annual VMT in 2008.

Factor 3: Meteorology (weather/transport patterns)

For this factor, EPA analyzed 30-years of National Weather Service (NWS) wind speed and wind 

direction data collected at the Atlanta International Airport to help determine transport patterns and 

source contributions. EPA assessed wind direction and speed for the 2009-2011 “ozone season” (March 

through October) in the Atlanta-Sandy Springs-Gainesville, GA-AL CSA. These analyses were 

conducted to better understand the fate and transport of precursor emissions contributing to ozone 

formation. EPA’s analysis of the NWS data indicate predominate east, northwest and west direction,

component for the Atlanta, GA area.

The predominant winds in the Atlanta-Sandy Springs-Gainesville, GA-AL CSA blow from the east, 

northwest and west direction, indicating counties from east , northwest and west direction could not be 

excluded for contributing to violations at the monitors in Cobb, DeKalb, Fulton and Henry Counties. 

EPA received additional meteorological information from the State of Georgia for the preliminary 

boundary determination for the Atlanta, GA nonattainment area, and this information was considered for 

this final designation. Georgia provided a supplemental meteorological analysis to correlate wind speed 

and wind direction with monitored ozone exceedances at the four violating monitors in the AtlantaSandy-Springs-Gainesville, GA-AL CSA, plus the Conyers monitor (i.e., located in Rockdale County) 

which was no longer violating based on 2009-2011 monitoring data. Georgia used this analysis to 

identify counties that are upwind and may be contributing ozone exceedances. EPA evaluated Georgia’s 

meteorological information and found that all of the counties that EPA is considering for inclusion in the 

nonattainment area boundary are upwind of a monitor with measured exceedances at some point during 

the 2009-2011 timeframe. These data helped inform the final nonattainment area designation. 

Factor 4: Geography/topography (mountain ranges or other air basin boundaries)

The geography/topography analysis evaluates the physical features of the land that might affect the air

shed and, therefore, the distribution of ozone over the area.

The Atlanta-Sandy Springs-Gainesville, GA-AL CSA does not have any geographical or topographical 

barriers significantly limiting air pollution transport within its air shed. Therefore, this factor did not 

play a significant role in this evaluation.
12

Factor 5: Jurisdictional boundaries

Once EPA identified the general areas that the Agency anticipated would be included in the 

nonattainment area, EPA then considered existing jurisdictional boundaries for the purposes of 

providing a clearly defined legal boundary and to help identify the areas appropriate for carrying out the 

air quality planning and enforcement functions for nonattainment areas. Examples of jurisdictional 

boundaries include existing/prior nonattainment area boundaries for ozone or other urban-scale 

pollutants, county lines, air district boundaries, township boundaries, area covered by an MPO, state 

lines, Areas of Indian Country, and urban growth boundary. Where existing jurisdictional boundaries 

were not adequate or appropriate to describe the nonattainment area, other clearly defined and 

permanent landmarks or geographic coordinates were considered.

The Atlanta, GA area has previously established nonattainment boundaries associated with both the 1-

hour and the 1997 8-hour ozone NAAQS. The Atlanta, GA nonattainment boundary for the 1-hour 

ozone NAAQS included 13 counties in Georgia in their entireties: Cherokee, Clayton, Cobb, Coweta, 

DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, and Rockdale. Whereas the 

Atlanta, GA nonattainment boundary for the 1997 8-hour ozone NAAQS included 20 counties in 

Georgia in their entireties: Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, 

Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and 

Walton. EPA concluded based on the factors mentioned above that a different boundary from that used 

for the 1-hour ozone and 1997 8-hour ozone NAAQS was warranted. EPA’s final boundary for the 

2008 8-hour ozone NAAQS is based on county boundary lines, and differs from the 1997 8-hour ozone 

boundary for the Atlanta, Georgia nonattainment area by the exclusion of Barrow, Carroll, Hall, 

Spalding and Walton Counties. 

Conclusion

On December 9, 2011, EPA notified Georgia that EPA intended to designate 18 counties in Georgia as 

nonattainment for the 2008 ozone NAAQS as part of the Atlanta, GA nonattainment area. These 18 

counties consisted of the 20 counties currently included in Atlanta’s 1997 ozone NAAQS nonattainment 

boundary minus two counties, Carroll and Hall Counties. EPA is not recommending including these 

two counties in the nonattainment area because both counties: had over 30 percent reduction in NOx 

and VOC emissions; less than 30 percent population growth between 2000 and 2010. Carroll County 

has a small portion connecting to a county with a violating monitor; however, Carroll County is adjacent 

to three other counties with attaining monitors of closer proximity. Hall County is not adjacent to any 

county with a violating monitor but is adjacent to two counties with attaining monitors.

Georgia’s February 29, 2012, supplemental technical analysis was submitted to EPA in response to 

EPA’s December 9, 2011, notification that it intended to designate 18 counties in Georgia as 

nonattainment for the 2008 ozone NAAQS as part of the Atlanta, GA nonattainment area. In their 

February 29, 2012, response Georgia provided a detailed analysis that considered; certified air quality 

monitoring data for 2009-2011, a review of factors similar to EPA’s and a robust meteorological 

analysis of wind patterns occurring during ozone exceedance events in the 2009-2011 timeframe. After 

considering Georgia’s analysis and based on EPA's reevaluation, EPA is designating 15 counties in the 

33-county Atlanta-Sandy Springs-Gainesville CSA as nonattainment for the 2008 ozone NAAQS as part 

of the Atlanta, GA nonattainment area. 
13

EPA is not finalizing a nonattainment designation for Carroll and Hall counties, mentioned above, and 

three additional counties (i.e., Barrow, Spalding and Walton) which EPA originally listed in its 

December 9, 2011, notification of the intended nonattainment boundary for the Atlanta, GA area. EPA

is not including these three counties in the nonattainment area for the following reasons. First, Barrow 

and Walton Counties are of sufficient distance from the nearest counties with violating monitors (based 

on 2009-2011 design values) such that it is unlikely that emissions in these counties contribute to the 

violations at those monitors. Local meteorological conditions and the existence of several attaining 

monitors between each of those counties and the nearest violating monitor further support that impacts 

from these counties are unlikely. Second, of the 18 counties identified in EPA's December 9, 2011, 

letter to Georgia, Barrow, Spalding, and Walton Counties are the least populated, among the four with 

the lowest population densities and lowest VMT. Third, the number of workers residing in Barrow, 

Spalding, and Walton Counties that work in counties with violating monitors range from 38 to 61 

percent below the next highest county with workers who residing in an attaining county but work in a 

violating county. Finally, Georgia's February 29, 2012, response shows that for all exceedances at the 

McDonough monitor in Henry County, which is the closest violating monitor to Spalding County, the 

wind direction was from the northwest which indicates that Spalding County emissions likely did not 

contribute to the violations at the McDonough monitor. Therefore, EPA has determined that Barrow, 

Spalding, and Walton Counties are unlikely to contribute to violations in the Atlanta-Sandy SpringsGainesville CSA, and should not be included in the Atlanta, GA nonattainment area.

Based on the assessment of factors described above, EPA has concluded that the following counties 

should be included as part of the Atlanta, GA nonattainment area because they are either violating the 

2008 ozone NAAQS or contributing to a violation in a nearby area: Bartow, Cherokee, Clayton, Cobb, 

Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Newton, Paulding and Rockdale 

in Georgia. The air quality monitors in Cobb, DeKalb, Fulton and Henry Counties in Georgia indicate 

violations of the 2008 ozone NAAQS based on 2009-2011 design values, therefore these counties are 

included in the nonattainment area. Bartow, Cherokee, Clayton, Coweta, Douglas, Fayette, Forsyth, 

Gwinnett, Newton, Paulding and Rockdale Counties in Georgia are nearby counties that do not have 

violating monitors, but EPA has concluded that these areas contribute to the ozone concentrations in 

violation of the 2008 ozone NAAQS as summarized below.

Bartow County: has 31,560 tons of NOx emissions and 6,165 tons of VOC emissions annually; 81 

percent of NOx emissions are being emitted by point sources, 45 percent of VOC emissions by mobile 

sources and 37 percent of VOC emissions by area sources; has a 2010 population over 100,000; has over 

a billion VMT in 2008; 32 percent of workers work in counties with violating monitors.

Cherokee County: has 4,908 tons of NOx emissions and 6,189 tons of VOC emissions annually; 65 

percent of NOx emissions are being emitted by mobile sources, 35 percent of VOC emissions by mobile 

sources and 42 percent of VOC emissions by area sources; has a 2010 population of 214,346; there are 

493 people per square mile; had a 57 percent population growth between 2000 and 2010; had over a 

billion VMT in 2008; 54 percent of workers work in counties with violating monitors.

Clayton County: has 16,105 tons of NOx emissions and 9,528 tons of VOC emissions annually; 63 

percent of NOx emissions are being emitted by point sources (the majority are from Hartsfield-Jackson 

Atlanta International Airport), 32 percent of VOC emissions by mobile sources and 34 percent of VOC 

emissions by area sources; has a 2010 population of 259,424; there are 1,797 people per square mile 

with a county size of only 144 square miles; had over two billion VMT in 2008; 51 percent of workers 

work in counties with violating monitors. 
14

Coweta County: has 15,852 tons of NOx emissions and 3,723 tons of VOC emissions annually; 79 

percent of NOx emissions are being emitted by point sources, 37 percent of VOC emissions by mobile 

sources and 45 percent of VOC emissions by area sources; had a 2010 population of 127,317; had a 

population growth rate of 41 percent between 2000 and 2010; had over a billion VMT in 2008; 30 

percent of workers work in counties with violating monitors.

Douglas County: has 3,368 tons of NOx emissions and 3,968 tons of VOC emissions annually; 75 

percent of NOx emissions are being emitted by mobile sources, 45 percent of VOC emissions by mobile 

sources and 49 percent of VOC emissions by area sources; had a 2010 population of 132,403; has a 

population density of 661 people per square mile with a county size of only 200 square miles; had a 43 

percent population growth rate between 2000 and 2010; over a billion VMT in 2008; 52 percent of 

workers work in counties with violating monitors.

Fayette County: has 2,732 tons of NOx emissions and 3,556 tons of VOC emissions annually; 64 

percent of NOx emissions are being emitted by mobile sources, 37 percent of VOC emissions by mobile 

sources and 50 percent of VOC emissions by area sources; has a 2010 population of over a 106,567; has 

a population density of 536 people per square mile with a county size of only 199 square miles; over a 

billion VMT in 2008; 35 percent of workers work in counties with violating monitors.

Forsyth County: has 3,823 tons of NOx emissions and 5,753 tons of VOC emissions annually; 60 

percent of NOx emissions are being emitted by mobile sources, 50 percent of VOC emissions by area 

sources and 29 percent of VOC emissions by mobile sources; had a 2010 population of 175,511; has a 

population density of 709 people per square mile; had a 75 percent population growth between 2000 and 

2010; over a billion VMT in 2008; 43 percent of workers work in counties with violating monitors.

Gwinnett County: has 18,569 tons of NOx emissions and 24,506 tons of VOC emissions annually; 60 

percent of NOx emissions are being emitted by mobile sources, 34 percent of VOC emissions by mobile 

sources and 47 percent of VOC emissions by area sources; had a 2010 population of 805,321; has a 

population density of 1,844 people per square mile; population growth rate of 35 percent between 2000 

and 2010; had seven billion VMT in 2008; 41 percent of workers work in counties with violating 

monitors.

Newton County: has 3,307 tons of NOx emissions and 4,248 tons of VOC emissions annually; 67 

percent of NOx emissions are being emitted by mobile sources, 49 percent of VOC emissions by mobile 

sources and 37 percent of VOC emissions by area sources; had a 2010 population of 99,958; has a 

population density of 358 people per square mile; 59 percent population growth between 2000 and 2010; 

over a billion VMT in 2008; 35 percent of workers work in counties with violating monitors.

Paulding County: has 2,780 tons of NOx emissions and 3,037 tons of VOC emissions annually; 66 

percent of NOx emissions are being emitted by mobile sources, 47 percent of VOC emissions by mobile 

sources and 44 percent of VOC emissions by area sources; had a 2010 population of 142,324; has a 

population density of 452 people per square mile; 71 percent population growth between 2000 and 2010; 

over a billion VMT in 2008; 57 percent of workers work in counties with violating monitors.

Rockdale County: has 2,483 tons of NOx emissions and 2,961 tons of VOC emissions annually; 64 

percent of NOx emissions are being emitted by mobile sources, 39 percent of VOC emissions by mobile 

sources and 47 percent of VOC emissions by area sources; had a 2010 population of 85,215; has a 

population density of 645 people per square mile; 44 percent of workers work in counties with violating 

monitors.