1 

### Atlanta, Georgia Area Designations f or the

20 08 Ozone National Ambient Air Quality Standard s

The t able below identifies the counties in Georgia that EPA is designating as “ no n attain ment ” for the

2008 o zone national ambient air quality standard s (20 08 ozo ne 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 analys i s supporting the boundar y for th is

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

Atla nta

, GA Cobb

DeKalb

Fulton Henry Bartow

Cherokee Clayton

Cobb

Coweta

DeKalb

Dou glas Fayette Forsyth

Fulton

Gwinnett Henry

Newton

P aulding

Rockdale

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

“ unclassifi able/ attainment ” for the 20 08 ozone NAAQS

.

The analysis below provides the basis for the Atlanta nonattainment area boundar y . It relies on EPA’s analysis of whether and which monitors are violating the 20 08 o zone NAAQS

, based on certified air quality m onitoring data from 200 9

- 201 1

, and an evaluation of whether nearby areas are contributing to

such violations. EPA has evaluated contribution s from nearby areas based on a weight of evidence analysis considering the factors identified below. EPA issued gu idance 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 (i ncluding 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. According ly, 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/CBSA s 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 n earby area is contributing to a violation of the 20 08 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

199 7 o zone NAAQS. Where a violating monitor is not located in a CSA or C BS A, 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 geo graphic 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 th e most recent update, based on 2008 population estimates, issued on December 1, 2009 (OMB Bulletin No. 10

- 02).3 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 b e designated as “nonattainment” for the 2008 ozone NAAQS based on air quality data from 2006

- 2008. Georgia p rovided an update to the original recommendation in October 2011 based on preliminary air quality data from 200 9

- 201 1

. In its updated recommendati on, 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 F E M monitors sited and operated in accordance with 40 CFR Part 58. (Georgia Department of Natu ral Resources (GDNR) letters dated March 12, 2009

, and October 25, 2011).4 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 Spring s

- Gainesville C SA, EPA intend ed 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 pr ovide 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 No nattainment 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

Dou glas Fayette Forsyth

Fulton

Gwinnett Henry

Newton

P aulding

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 the ir October 2011 recomm endation . 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 Spring s

- Gainesville CSA

. After considering Georgia’s recommendation and additiona l technical information, and based on EPA's reevaluation of the

18 counties as described below, EPA is designating 1 5 counties in Georgia as “nonattainment” for the 2008 ozone NAAQS as part of the Atlanta , GA nonattainment area.

EPA originally started wit h 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 t he recommendation s 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 oz one NAAQS as part of the Atlanta, GA nonattainment area.5 Factor Assessment



### Factor 1: Air Quality Data

For this factor

, EPA considered 8

- hour o zone design values (in p arts per billion (p p b) ) for air quality

monitors in counties in the Atlanta

- Sandy Springs

- Gainesville CSA, based on da ta for the 200 9

- 201 1 period (i.e., the 201 1 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

- 20 10 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 o zone NAAQS are met at a monitor when the annual f ourth

- 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 App endix 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 201 1 design values for the o zone NAAQS for counties with monitors in the Atlanta

- Sandy Springs

Gainesville CSA are shown in Table 3

. (Counties not identifi ed do not have monitors)

Table 3 . Air Quality Data

.

County * State Recommended

Nonattainment? 200 9

- 201 1 Design Value (ppb) Cobb, GA Yes 7 8
Coweta, GA No 6 7 DeKalb, GA Yes 7 7 Douglas, GA No 7 4 Fulton, GA Yes 80 Gwinnett, GA No 7 5 Henry, GA Yes 7 8 Paulding, GA No 7 1
Rockdale, GA No 7 5 *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 th e 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 desi gn 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 viola ting

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

.6 

### Factor 2: Emissions and Emissions

- Related Data

EPA evaluated emissions of ozone precursors (i.e, NOx a nd VOC emissions), and other emissions

related data that provide information on areas contributing to violating monitors.

Emissions Data

EPA evalua ted 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 consider ed any additional information we receive d on changes to emissions levels tha t 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 Stat e used the same data source for emissions

related 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

determin ation, Georgia also considered: (1) NOx and VOC emission density (tons/mile 2 ) ; 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 d ata from the 2008 NEI version 1.5 referenced above. Table 4 shows emissions

of NO x 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 NO x and VOC Emissions.

County * State Recommended

Nonattainment? NO x (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 24,5067 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, Clayto n, Cobb, Coweta, DeK alb, 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

- Jackso n Atlanta International Airport.

Barrow, Carroll, Cherokee, Douglas, Fayette, F orsyth, Hall, Henry, Newton, Pauldin g, Rockdale

, Spalding, Troup, and Walton Counties each have between 1,7 00 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, Po l k,

Rockdale , Spalding, Troup, Up son 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, Po l k, Rockdale, Spalding, Troup, Upson and Walton Counties have over 30 percent of VOC emissions from area sources.8 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

- poi nt 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 ar ea 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 co re 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 A rea.

Table 5 . Population and Growth.

County * State

Recommended

Nonattainment? 20 10 Population 20 10 Population Density ( p eople /sq mi) Absolute change in population (2000

- 2010) Population % change (2000

- 20 10 )
Barrow No 69,367 42 6 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

Cowet a 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 1,8 44 208,978 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 37,07 4 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 8,121 149 Upson No 27,153 83

- 462

- 2

Wa lton 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.

Source s : U.S. Census Bureau population estimates for 20 10 as of August 4, 2011 ( http://factfinder2.census.gov/face s/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 Coun ties 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 20 10. 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 5 0 percent between

2000 and 2010. Barr ow, 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 VM T and/or a high num b er 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 n umber of c ounty w orkers for each county in the area.10 Table 6 . Traffic and Commuting Patterns

.

County State

Recommended

Nonattainment? 200 8 Annual

VMT * (million miles) Number of County

Workers ** (2009 data) Percent of County

Workers that Wo rk 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 N o 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 fo rce 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.11 Cobb, DeKalb and Fulton Counties had over six billion annual VMT in 2008. Ba rtow, 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 200 9

- 201 1 “ozone season” (March through October) in the Atlanta

- Sandy Springs

- Gainesville , G A

- 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 ea st, northwest and west direction, component for the Atlanta, G A area

.

The predominant winds in the Atlanta

- Sandy Springs

- Gainesville , G A

- 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 A tlanta

Sandy

- Springs

- Gain e sville , 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 contribut ing ozone exceedances

. EPA evaluated Georgia’s meteorological information and found that all of the counties that EPA is consider ing for inclusion in the nonattainment area boundary are upwind of a monitor with measured exceedances at some point during

th e 2009

- 2011 timeframe. These data help ed 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 consider ed existin g 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

b oundaries include existing/prior nonattainment area boundarie s for ozone or other urban

- scale pollutants, county lin es, air district boundarie s, township boundarie s, area covered by a n 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 c oordinates were considered.

The Atlanta, GA area has previously established nonattai nment boundaries associated with both the 1

- hour and the 1997 8

- hour ozone N AAQS. 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, Fay ette, Fo rsyth, 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, Spal ding, 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 NAAQ S 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 e xclusion of Barrow, Carroll

, Hall

, Spalding and Wa lton 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 co unties currently included in Atlanta’s 1997 ozone NAAQS nonattainment boundary minus two counties, Carroll and Hall Counties. E PA is not recommending including these two counties in the nonattainment area because both counties: had over 30 percent reduct ion 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 moni tors 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 D ecember 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 cons idered; 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 analys is 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 desig nation for Carro l l 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 u nlikely that emissions in these counties contribute to the

violations at those monitors

. L ocal meteorological conditions and the existence of several attaining monitors between each of those counties and the nearest violating monitor further support that impact s from these counties are unlikely

. Second, o f 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

violati ng 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 Sp alding 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 Springs

Gainesville CSA , a nd 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 vio lating the 2008 ozone NAAQS or contributing to a violation in a nearby area : Bartow, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hen ry, 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,

Gwinn ett, 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 po pulation 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 emitt ed 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

source s 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 per cent 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

sour ces 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 wor k 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 perc ent 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 count ies 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 emi ssions 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; ha d 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 em issions by mobile

sources and 47 percent of VOC emissions by area sources; had a 2010 population of 8 5,215 ; has a population density of 645 people per square mile; 44 percent of workers work in counties with violating

monitors.