# NA NCDENR North Carolina Department of Environment and Natural Resources Beverly Eaves Perdue, Governor 

### Dee Freeman, Secretary

October 28, 2011 Gwendolyn Keyes Fleming Regional Administrator USEPA, Region 4 Sam NunnFederal Center 61 Forsyth Street, SW Atlanta, Georgia 30303-8960
Dear Ms. Fleming:
Pursuant to the requirements ofthe federal Clean Air Act and onbehalfofGovernor Beverly E. Perdue, I am submitting to you and your colleagues at the U.S. Environmental Protection Agency (EPA) the State ofNorth Carolina's revised recommendations for boundaries delineating the areas inthe**S~te** that either attain or do not attain the March 12,2008 8-hour standard for ozone. We believe the boundaries described in the enclosed package are the most effective way to achieve the goals ofthe CleanAirAct. We look forward to discussing these recommendations with you after EPA has had the opportunity to review and comment onthem.
The federal CleanAirActrequires EPA to designate areas as attainment 

### Ofnonattainment following promulgation ofa new national ambient air quality standard. The EPA has asked states for their recommendations for nonattainment boundaries by October 28, 2011. Please note that North Carolinaplans to certify its 2011 ambient air quality datafor ozone by the end of2011 so that this data may be used in determining nonattainment boundaries for the March 12,2008 8-hour standard for ozone.
Based onextensive public discussion ofour initial boundary recommendations for the 2008 ozone standard submitted in March 2009 and analysis ofthe current ambient air quality datathrough 2011, we are recommending that six entire counties and one partial county inthe CharlotteGastonia-Salisbury metropolitan areabe designated as nonattainment for the 2008 8-hour ozone standard and all remaining areas be designated as attainment. The proposed nonattainment areais consistent with the areathat was designated nonattainment for the 1997 8-hour ozone standard. North Carolina was able to attainthe 1997 8-hour ozone standard using this recommended nonattainment boundary area.
North Carolina learned ofthe need to update the boundary recommendations in a call with EPA Region 4 staffon September 29, 2011. As a result, the state has not had sufficienttime to consult with local elected officials and other partners priorto this submittal. North Carolinareserves the right to further amend these recommendations as we have the opportunity to do that overthe

1601 Mail Service Center, Raleigh, North Carolina 27699-1601 Phone: 919-733-4984/ FAX: 919-715-3060/lntemet: www.enr.state.nc.us/ENR

# N~rthCarohnaMs. Fleming October 28,2011 Page 2
coming weeks. Any changes in the state's recommendations will be communicated during the 120 day process that will follow EPA's response to these initial recommendations.
North Carolina has been working hard to address ozone pollution in conjunction with ourmany local, state, and national partners. Overthe past decade, North Carolinahas implemented substantial, progressive emissions reductions that have resulted in attainment ofthe 1997 8-hour ozone standard statewide. Underthe North Carolina legislature's Clean Air Bill of 1999, the State's vehicle inspection and maintenance programwas changed to an on-board diagnostic (OBD) program that now covers 48 counties. In addition to implementation ofthe NOx SIP Call rules, in 2002 North Carolina's General Assembly also enacted the landmark multi-pollutant legislation known as the Clean Smokestacks Act which continues to result in significant sulfur dioxide and nitrogen oxides (NOx) emissions reductions from the State'stwo largest electric utility companies. As demonstrated bythese and other actions, North Carolina is committedto improving air quality.
North Carolina believes that good air quality is vital to the health of our citizens, the state's environment, and future economic growth and quality oflife. We look forward to continuing to work with EPA and our other partners to develop strategies to attain the 2008 8-hour ozone standard. More detailed information and supporting data are included in the enclosed recommendation package. Thank you for your consideration ofthese recommendations. Sincerely,

# ?~e~~---"/) Secretary
DF:lab
Enclosure

c: The Honorable Beverly E. Perdue The Honorable Steve Troxler The Honorable Gene Conti The Honorable J. Keith Crisco Sheila C. Holman

# Supplement to the
State 

# ofNorth Carolina's
Recommendation on Boundaries
For the 2008 8-Hour Ozone Standard

March 12, 2009 Revised October 28, 2011 Governor Beverly Perdue(This Page Is Intentionally Blank)

# Table ofContents
Introduction 1 Background 1 Summary ofRecommendations 3 Area Specific Recommendations on Boundaries for 8-hour Ozone Nonattainment 7

I Charlotte-Gastonia'-Salisbury Metropolitan Area Discussion 7

EPA's

### Presumpti~e 8-Hour Ozone Nonattainment Boundary: ; 7 North Carolina's R.ecommended 8-Hour Ozone Nonattainment Boundary: 7 Charlotte-Gastonia-Salisbury CSA 8-Hour Ozone Design Values: 7 Anson County 8 Cleveland County 11 Iredell County 12 Stanly County 14



# Table ofFigures
Figure 1: North Carolina's 2009-2011 8-Hour Ozone Design Values Map 2 Figure 2: North Carolina's Revised Recommendation For 8-Hour OzoneNonattainmentArea Boundaries 3 Figure 3: Charlotte-Gastonia-Salisbury Regional 2009-2011 8-Hour Ozone Design Values 8 Figure 4. Population Density Map for the Charlotte-Gastonia-Salisbury CSA based onthe 2010 Census 10 Figure 5. Percent Growth Between 2000 and 2010 for Iredell County 13



# table ofTables

Table 1: North CarolinaBoundary Recommendation for 8-Hour Ozone Standard 3 Table 2: Charlotte-Gastonia-Salisbury Regional Ozone DesignValue Table 7



# Table ofAppendices
Appendix A: North Carolina's 2009-2011 8-Hour Ozone Design Values Map & Table(I'his Page Is IntentionallyBlank)

### Introduction
The purpose ofthis document is to provide the State ofNorth Carolina's revised recommendations onboundaries for the 2008 8-hour ozone standard.
OnMarch 12,2008, the United States Environmental Protection Agency (EPA) promulgated
a revised 8-hour ozone National Ambient Air Quality Standard (NAAQS) of75 parts perbillion (Ppb). OnMarch 12, 2009, the State ofNorth Carolina submitted its boundary recommendation for nonattainment areas based onthe ambient air quality data for 2006-2008. However, in September 2009, the EPA announced that they were going to reconsiderthe 2008 ozone standard and postponed implementation ofthis standard. Itwas announced thatthe reconsideration ofthe 2008 ozone standard wouldbe withdrawn on September 2, 2011.
The EPA is now moving forward withthe implementation ofthe 2008 ozone standard. Since most states had submittedboundary recommendations in 2009, the EPAhas advised states thatthey will use the boundary recommendations previously submitted and update them based on the 2008-2010 ambient airquality data. The EPA has requested states wishing to revise their boundaryrecommendations to submitthemby October 28, 2011. The EPA also agreed to use 2009-2011 ambient air quality data for the designationprocess ifa state planned to certifytheir 2011 data early.
North Carolina has elected to certifythe 2011 ambient airquality dataearly and has made its revised boundaryrecommendations based onthe 2009-2011 data. 

### Background
The Clean Air Act (CAA) requitesthe EPAto designate areas as attainment or nonattainmeilt following the promulgation ofa newNAAQS. The nonattainment boundaries are to be based onthe data collected atthe ambient air monitoring stations. The State and local air programs operate the ozone monitoring sites. The data is quality assured, and then submitted to the EPA where it becomes part ofa national database. The CAA requires thatthe monitoring databe evaluatedto determine which monitors meetthe standard and whichmonitors violate the standard. Forthe 8-hourozone standard, three years worth ofdata for each monitor is evaluated. The fourth highest daily maximUIi1 8-holir average ozone value for each ofthe three years is averaged together, and the resulting average is then compared to the standard. The**three~year** average is referred to as the design value. Withtheir action onMarch 12, 2008, the EPA revised the 8-houfozone standard to 75 ppb. Therefore, a monitoredthree-year average of75 ppb is considered to meet or attain the standard, while a three-year average of76 ppb or greater is consideredto violate the ambient standard.
North Carolina has evaluatedthe ozone monitoring data for the State for the three-year period of2009-201 1, and has determinedthat a total of4 out of40 monitors currentlyviolate the 2008 8-hour ozone standard based onthe pre-certified data for 2011. Figure 1 displays a map ofthe 2009-2011 8-hour ozone design values for North Carolina. This map and a table used for calculating the respective design values are included inAppendixA. The four violating monitors are all located inthe Charlotte-Gastonia-Salisbury metropolitan area.

1

# Statewide 8-Hour Ozone Design Values 2009-201!1 8-Hour Ozone Design Values

o Attaining (75 ppb or less)

@ Nonattaining (76 ppb or gre,ater)



### Figure 1: North Carolina's 2009-2011 8-HourOzone Design Values Map (Please Note That All DesignValue Concentrations Presented Above Are In Parts Per Billion (Ppb) and that the 2011 ambient air quality data has not been certified)

2

### Summary ofRecommendations
The State ofNorth Carolina's revised recommendations for the designation ofareas ofthe state for the 2008 8-hour ozone standard is nonattainment for Cabarrus, Gaston, Lincoln, Mecklenburg, Rowan, Union Counties, a partial county nonattainment recommendation for Iredell County; and attainment designation for the remaining areas in North Carolina. The nonattainment area boundaryrecommendation for the CharlotteGastonia-Salisbury metropolitan area is displayed inFigure 2. This is the same areainNorth Carolinathat was designated nonattainment for the 1997 8-hour ozone standard for the Charlotte-Gastonia-Salisbury metropolitan area. Table 1 summarizes North Carolina's recommendation ofareas as nonattainment or attainment for the 2008 8-hour ozone NAAQS.

Figure 2: North Carolina's Revised Recommendation For 8-Hour Ozone Nonattainment Area Boundaries

Table 1 is North Carolina's revised recommendation ofareas as nonattainment or attainment underthe revised 8-hour ozone standard.

Table 1: North Carolina Boundary Recommendation for 8-Hour Ozone Standard Designated Area DesignationType Charlotte-Gastonia-SalisburyArea: Cabarrus County Gaston County Iredell County (part) Davidson Township Coddle Creek Township Lincoln County Mecklenburg County Rowan County Union County Rest ofState Alamance County

. Nonattainment

Attainment 3Table 1: North Carolina Boundary Recommendation for 8-Hour Ozone Standard Designated Area Designation Type Alexander County Attainment Alleghany County Attainment Anson County Attainment Ashe County Attainment Avery County Attainment Beaufort County Attainment Bertie County Attainment Bladen County Attainment Brunswick County Attainment Buncombe County Attainment Burke County Attainment Caldwell County Attainment Camden County Attainment Carteret County Attainment Caswell County Attainment Catawba County Attainment Chatham County Attainment Cherokee County Attainment Chowan County Attainment Clay County Attainment Cleveland County Attainment Columbus County Attainment Craven County Attainment Cumberland County Attainment Currituck County Attainment Dare County Attainment Davidson County Attainment Davie County Attainment Duplin County Attainment Durham County Attainment Edgecombe County Attainment Forsyth County Attainment Franklin County Attainment Gates County Attainment Graham County Attainment Granville County Attainment Greene County Attainment Guilford County Attainment Halifax County Attainment Harnett County Attainment Haywood County Attainment Henderson County Attainment Hertford County Attainment Hoke County Attainment Hyde County Attainment 4Table 1: North Carolina Boundary Recommendation for 8-Hour Ozone Standard Designated Area Designation Type Iredell County (part) Attainment Barringer Township Attainment Bethany Township Attainment Chambersburg Township Attainment Concord Township Attainment Cool Springs Township Attainment Eagle Mills Township Attainment Fallstown Township Attainment NewHope Township Attainment Olin Township Attainment Sharpesburg Township Attainment Shiloh Township Attainment Statesville Township Attainment Turnersburg Township Attainment Union Grove Township Attainment Jackson County Attainment Johnston County Attainment Jones County Attainment Lee County Attainment Lenoir County Attainment Macon County Attainment Madison County Attainment Martin County Attainment McDowell County Attainment Mitchell County Attainment Montgomery County Attainment Moore County Attainment Nash County Attainment NewHanover County Attainment Northampton County Attainment Onslow County Attainment Orange County Attainment Pamlico County Attainment Pasquotank County Attainment Pender County Attainment Perquimans County Attainment Person County Attainment Pitt County Attainment Polk County Attainment Randolph County Attainment Richmond County Attainment Robeson County Attainment Rockingham County Attainment Rutherford County Attainment Sampson County Attainment 5Table 1: North Carolina Boundary Recommendation for 8-Hour Ozone Standard Designated Area Designation Type Scotland County Attainment Stanly County Attainment Stokes County Attainment Surry County Attainment Swain County Attainment Transylvania County Attainment Tyrrell County Attainment Vance County Attainment Wake County Attainment Warren County Attajnment Washington County Attainment Watauga County Attainment Wayne County Attainment Wilkes County Attainment Wilson County Attainment Yadkin County Attainment Yancey County Attainment

6

### Area Specific Recommendations on Boundaries for 8-hourOzone Nonattainment
The revised recommendations address the designation areaboundary criteria laid out inthe December4, 2008 memo from Robert 

### J. Meyers, Principal Deputy Assistant Administrator entitled, "AreaDesignations for the 2008 Revised OzoneNational AmbientAir Quality Standards". The designation recommendations are also consistentwiththe methodology behind the establishment ofall existing andprevious 8-hour ozone nonattainment area boundaries inNorth Carolina.
The purpose ofthe remainder ofthis document is to address the criteriathat EPA established for considering boundaries less thanthe full Core Based Statistical Area (CBSA) orCombined Statistical Area (CSA) for nonattainment designation. The remaining documentation only addresses in detail those areas where North Carolina's revised recommendation is less thanthe full CBSA orCSA. 

### Charlotte-Gastonia-SalisburyMetropolitan Area Discussion

EPA's Presumptive 8-Hour OzoneNonattainmentBoundary: The EPA'spresumptive nonattainmentboundary would include Anson, Cabarrus, Cleveland, Gaston, Iredell, Lincoln, Mecklenburg, Rowan, Stanly, and Union Counties.


### North Carolina's Recommended 8-Hour OzoneNonattainmentBoundary: ' North Carolina's recommended nonattainment boundary includes Cabarrus, Gaston, Lincoln, Mecklenburg, Rowan and Union Counties and the Townships ofDavidson and Coddle Creek

### in Iredell County. 

### Charlotte-Gastonia-Salisbury CSA 8-Hour Ozone Design Values: Table 2 below contains the design values for the monitors located 

### in the Chadotte-Gastonia-Salisbury CSA, along with the fourth highest 8-hour average ozone concentrations for 2009 through 2011 which are used to calculate the design values. Figure 3 displays the design values inthe monitor locations.
bl 2 

### Ch I 

### tte-G t . S

### a

## r ISb 

### ee;lona10 

### DeSlgn . V I Tabl T

### a e : 

### ar 0 

### as onla- ury R' 

### zone a ue e Annual4tn Highest 8-hr Average 

# I Design Value 

### Monitoring Sites County 

# 1,1 

# i.' • 2009**~-** "-" .-- ....... " .

.. Lincoln 0.065 Mecklenburg 0.068 

# III Mecklenburg 0.071 Crouse Arrowood County Line Garinger (Plaza) Enochville Rockwell Monroe l . 

# I.

Mecklenburg 0.069 Ij 

# JI Rowan 

## Ii. 0.073 Rowan 0.071 Union 0.067 

# • ..' 

# '. 2010 2011 2009-2011

, .-.,. .. ._.­

. . .- .
_ .. ._. - . 0.072 0.077 0.071 0.078 0.082 0.076 

# :.

0.082 0.083 

# f. 0.078 0.082 0.088 0.079 

# i. 

# :. 0.078 0.078 0.076 0.077 0.077 0.075 0.071 0.073 0.070

7Cleveland

Regional 8-Hour Ozone Design Values Unim 70 

### • Anson

2009-2011 9-Hour Ozone Oooign Values

• Altaining (75 ppb or less)

• Nonattalning (76 ppb orrrcre) 

### o Metrolina County Borders Figure 

### 3: Charlotte-Gastonia-Salisbury Regional 2009-2011 8-Hour Ozone Design Values

Four ofthe monitors in the Charlotte-Gastonia-Salisbury metropolitan area currently measure the highest ozone values inthe State. North Carolinarecommends that the whole counties ofCabarrus, Gaston, Lincoln, Mecklenburg, Rowan and Union and the partial county ofIredell be designated as nonattainment. This is the same area inNorth Carolinathat was designated nonattainment for the 1997 8-hour ozone standard for the Charlotte-Gastonia-Salisbury metropolitan area. Additionally, North Carolina effectively attained the 19978­ hourozone standard with this recommended nonattainment boundary area.
The counties not recommended and the partial county recommendation are discussed below, along with the 9 criteriathe EPA identified in their nonattainment boundary guidance that should be addressed.
Anson County This is a Micropolitan Statistical Area county within the Charlotte-Gastonia-Salisbury CSA, and it does not have a monitor located in the county. This is a mostly rural county with a low impact from commuting traffic into the urbanized core ofthe CSA. Therefore, North Carolina is recomniending no portion ofthe county be designated as nonattainment.
Air Quality Data: As shown in Figure 3 above, this area has 7 monitors with design values ranging from 70 to 79 ppb. The monitor located nearest Anson County is inneighboring Union County in Monroe with a design value of70 ppb. Ondays when this monitor has the highest readings, the winds generally are out ofthe southwest. Since Anson County is east ofthis monitor, the emissions from this county are not expected to impact the air quality on days when this monitor would observe an exceedance ofthe 2008 ozone standard.

8Emissions Data: Based on 2009 emissions inventories, Anson County has annual point source emissions of 129 tons and 66 tons ofnitrogen oxides (NOx) and volatile organic compounds (VOCs), respectively. There are no majorpoint sources located within the county. Population Density and Degree ofUrbanization: 26,948 people live in Anson County. The northernportion ofAnson County is a largely rural county withno census tracts having a population density greater than 250 people per square mile. Figure 4 below displays the population density map for the Charlotte-Gastonia-Salisbury CSA.
Traffic and CommutingPatterns: Anson County has 828,400 Daily VMT, according to 2009 data. Anson County contributes less than halfof 1 percent ofthe commuters who drive into Mecklenburg County to work each day. Based upon historic trends overthe lastten years, the VMT are not expectedto change significantly overthe nextten years. Growth Rates and Patterns: The population inAnson County increased by 6.6% from 2000 to 2010, contrary to the 2000 census predictionthat the population would decrease by 1.7% during this time period. However, even withthe population increase, this is a very modest growth rate compared to the more urban areas ofNorth Carolina and Anson County remains a very rural area. The population is expected to slightly increase from 2010 to 2020 by 1.9%. This county is not expected to grow enoughto become a significant contributorto ozone exceedances inthe Charlotte-Gastonia-Salisbury CSA. Meteorology: Winds across Anson County are climatologically from the southwest. Withthis climatological wind pattern, the emissions inthe county are not expected to impact the ambient air quality inthe CSA. Geographyffopography: There are no special geography ortopography issues to consider in this region.
Jurisdictional Boundaries: The existing 1997 8-hour ozone standard nonattainment area does not include Anson County and it is not included inNorth Carolina's recommendations for nonattainment areas under the 2008 8-hour ozone standard.
Level ofcontrol ofemissions sources: There are no majorpoint sources to consider controls withinthe county. Mobile sources are another source ofNOx emissions. The combinedFederal and state control programs for mobile sources address these emissions. Anson County does not currently have an on-board diagnostic (OBD) based inspection and maintenance (lIM) program, but requires an annual visual inspection ofemissions equipment. Lowsulfur gasoline is required statewide.

.



### 9"

" legeod 

# t:J Metrolina countyBorders, MetroUl1a Populatiori20:1(). 'Density (per SCiuaremlfeJ, D(}-50

- 

### ,0 50

-100 

# o 10()c25O , 

## CJ 25(}-500' " ' • " 

# o 5O(}-1000'" 

### 0 1000-2500 02500-5000' C:]'5000+ ,Anson. ,J.

..... 

### '1**<._-".,-~** ...>

Population DataSouTce,: U.S. Census Bureau (2010) Figure 4. Population-Density 

### Map for the Charlotte-Gastonia-Salisbury CSA based on the 2010 Census

10

### Cleveland County This is a Micropolitan Statistical Area county withinthe Charlotte-Gastonia-Salisbury CSA, and it does nothave a monitor located inthe county. This is a mostlyrural county with a lowimpactfrom commuting traffic into the urbanized core ofthe CSA. Therefore, North Carolinais recommending no portion ofthe county be designated as nonattainment.


### Air Quality Data: As showninFigure 3 above, this CSA has 7 monitors with design values ranging from 70 to 79 ppb. The monitor located nearest Cleveland County is inneighboring Lincoln County in Crouse with a design value of7l ppb. On days when this monitorhas the highest readings, the winds generally are out ofthe southwest. Portions ofCleveland County are located southwest ofthis monitor, however, sincethere are no majorNOx sources located in Cleveland County andthis monitor is attaining the 2008 ozone standard, it is not likely that emissions from this county would contribute to a violation ofthe 2008 standard inthe CSA.


### Emissions Data: Based on 2009 emissions inventories, Cleveland Countyhas annual point source emissions of 150 tons and 412 tons ofNOx and VOC,respectively. There is one majorVOC point source in the county andno major sources ofNOx. 

### Population Density and DegreeofUrbanization: 98, 078 people live in Cleveland County. Cleveland County is predominantly a rural county with eleven large census tracks with 250people orless per square mile. In Shelby, located in central Cleveland County, the population density ranges from 250to 2500 people per square mile. InKings Mountain, located in southeast Cleveland County, the population density is 500 to 1000people per square mile. (See Figure 4)


### Traffic and CommutingPatterns: Cleveland County has 2,709,540 Daily VMT, according to 2009 data. Cleveland County contributes less than 1percentofthe commuters who drive into Mecklenburg Countyto work each day. Basedon the historic trends, the VMT are expectedto increase by less than onepercent annually over the next ten years. 

### Growth Rates and Patterns: The population ofCleveland Country grewby 1.9%between 2000 and 2010. Thepopulation in Cleveland County is expected to grow slightly between 2010 and2020, with an increase of3.2%. These
are very small growth rates comparedto otherparts ofNorth Carolina. This county is not expectedto grow enoughto become a significant contributorto ozone exceedances inthe Charlotte-Gastonia­ Salisbury CSA. 

### Meteorology: Winds across Cleveland County are climatologically from the southwest, which is inthe direction ofthe closest monitor located inLincoln County. However, the Lincoln County monitoris attaining the 2008
ozone standard and there are no majorNOx sources located in Cleveland Co.unty. Therefore, it is not likelythat emissions from Cleveland County would contribute to a violation ofthe 2008 ozone standard.

11

### Geographyffopography: There are no special geography ortopography issues to consider inthis region.


### Jurisdictional Boundaries: The existing 1997 8-hour ozone standardnonattainment area does not include Cleveland County and it is not included inNorth Carolina's recommendations for nonattainment areas underthe 2008 8-hour ozone standard.


### Level ofcontrol ofemissions sources: Cleveland County currently has one majorVOC point source and no majorNOx sources. Since North Carolina is NOx limited with respect to ozone formation, controlling man-made VOC sources does not reduce ozone concentrations. Therefore, the level ofcontrol for this VOC source shouldnot be of consideration for nonattainment boundary designation. Mobile sources are another source ofNO

### x emissions. The combined Federal and state control programs for mobile sources address these emissions. Cleveland County currently has an OBD based I/M program and low-sulfur gasoline is required statewide.


### Iredell County This is a Micropolitan Statistical Area county withinthe Charlotte-Gastonia-Salisbury CSA, and it does not have a monitor located inthe county. This is a high commuter county into the Charlotte area along the 1-77 corridor. The northernportion ofthe county is rural, so the recommendation is for a smaller areathanthe entire county.
The recommendation is thatthe two townships inthe southernportion ofIredell County, Coddle Creek and Davidson Townships, be designated as nonattainment.


### Air Quality Data: As shown inFigure 3 above, this CSAhas 7 monitors with design values ranging from 70 ppb to 79 ppb. The monitor located closest to Iredell County is in neighboring Rowan County in Enochville with a design value of76ppb. However, on days whenthis monitorhas the highest readings, the winds are generally out ofthe southwest, indicatingthat the emissions from the northern portion ofIredell County are not likelyto contribute to the Enochville monitor's high ozone levels since this area is north and east this monitor. Since a significant amount ofcommutertraffic from the southerntwo townships travel into Mecklenburg County, the lowertwo townships may be impacting the ambient airquality data inthis CSA. Therefore, North Carolina is recommendingjustthe two lowertownships be designated nonattainment.


### Emissions Data: Based on 2009 emissions inventories, Iredell County has annual point source emissions of2,087 tons and 927 tons ofNOx and VOC, respectively. There are some industrial sources inthe county, including a natural gas pumping station, which is subjectto the NOx SIP call. 

### Population Density and Degree ofUrbanization: 159,437 people live inIredell County and 65,385 people live in the two townships recommended as nonattainment, which is 41 

### % ofthe County's population. The northern, eastern and western portions of Iredell County have lowpopulation density with 16 census tracks containing 250 people orless per square mile. Statesville, located incentral Iredell County, has population density ranging from 250 to 2500 people per square mile. The southernportion ofIredell County, where Mooresville is located, is 12more densely populated. Mooresville'spopulation density ranges from 1000 to 2500 people per square mile (see Figure 4). This more densely populated area is located in the two townships being recommended for nonattainment.


### Traffic and CommutingPatterns: Iredell CoUnty has 5,762,800 average daily vehicle milestraveled (VMT), according to 2009 data. Iredell County contributes 2.02 percent ofthe commuters who drive into Mecklenburg County to work each day. Iredell ranks number 5 inthe commuting counties into Mecklenburg. These VMT are expected to increase to approximately 7,300,000 by 2020.


### Growth Rates and Patterns: The population in Iredell County grew considerably from 2000 to 2010, increasing by 30%, and an additional growth of 17.2% is expected between 2010 and 2020. The majority ofthis growth occurred in the two southerntownships beingrecommended for nonattainment. Figure 5 displays the percent growth between2000 and 2010 for eachtownship. Davidson Township's population growth was 90 percent and Coddle Creek Township's growth was 43 percent. All othertownships were less than 40 percentwith most being lessthan 20 percent.

Legend Iredell Townships Population growth in percent, 2000-2010 10% or less 0 10-20% 0 20-40% 0 40-50% CJ More than 60% 

### Figure 5. Percent Growth Between 2000 and 2010 for Iredell County
Meteorology: Winds across Iredell County are climatologically from the southwest. Withthis climatological wind pattern, the emissions inthe county are more likely to impact areas outside ofthe CSA. However, the
13commutertraffic emissions from the southerntwo townships would still impact the air quality in the CSA evenwith southwest winds. Therefore, North Carolina is recommendingjustthe two lower townships be designated nonattainment. Ondays when the winds are from the north, the emissions will add to the Charlotte area'spollution. Geographyffopography: There are no special geography ortopography issues to consider in this region.
Jurisdictional Boundaries: The existing 1997 8-hour ozone standard nonattainment area includes the southernportion ofIredell County, and is consistent with North Carolina's recommendations for nonattainment areas under the 2008 8-hour ozone standard.
Level ofcontrol ofemissions sources: Iredell County currently has 2 majorpoint sources for NOx and one major point source for VOCs. The natural gas pumping station, located in Davidson Township, is subject to the NOx SIP Call and has taken permit limits to address the requirements ofthe NOx SIP Call. The other large NOx source is a glass manufacturer locatedjust outside ofthe recommended nonattainment area, which bums only natural gas, a lower emitting fossil fuel. Mobile sources are another source ofNOx emissions. The combined Federal and state control programs for mobile sources address these emissions. Iredell County currently has an OBD based liMprogram and low-sulfur gasoline is required statewide. Stanly County This is a Micropolitan Statistical Area county withinthe Charlotte-Gastonia-Salisbury CSA, and it does not have a monitor located in the county. This is a mostly rural county with a low impact oncommuting traffic into the urbanized core ofthe CSA. Therefore, North Carolina is recommending no portion ofthe county be designated as nonattainment.
Air Quality Data: As shown in Figure 3 above, this CSA has 7 monitors with design values ranging from 70 to 79 ppb. The monitor located nearest Stanly County is inneighboring Rowan County in Rockwell with a design value of75 ppb. On days when this monitor has the highest readings, the winds are generally out ofthe southwest. Since Stanly County is located south and east ofthis monitor and there are no large NOx sources located inthis county, 

### it is not likely that the emissions from this county would impact the air quality inthe CSA when this monitor observes an exceedance ofthe 2008 ozone standard.
Emissions Data: Based on 2009 emissions inventories, Stanly County has annual point source emissions of269 tons and 371 tons ofNOx and VOC, respectively. There is one majorVOC point source and no major sources of NOx emissions in Stanly County. Population Density and Degree ofUrbanization: 60,585 people live in Stanly County. Stanly County is a predominantly rural areawithmost ofthe county having a population density of250 people or less per square mile. Albemarle, located in northeast Stanly County, is the onlypopulous area with a population density of 1000 to 2500 people per square mile (Figure 4).

14Traffic and CommutingPatterns: Stanly County has 1,342,620 Daily VMT, according to 2009 data. Stanly County contributes less than 1 percent ofthe commuters who drive into Mecklenburg County to work each day. Based onhistoric trends, the VMTare expected to increase by less than 0.5% annually overthe next tenyears. Growth Rates and Patterns: The population in Stanly County increased slightly from 2000 to 2010 by a rate of4.3%, with a further population increase of7.3% expected from 2010 to 2020. This is a very modest growth rate compared to the more urban areas ofNorth Carolina and Stanly County remains predominantly a rural area. This county is not expected to grow enoughto become a significant contributor to ozone exceedances in the Charlotte-Gastonia-Salisbury CSA. Meteorology: Winds across Stanly County are climatologically from the southwest. Withthis climatological wind pattern, the emissions inthe county are not expected to impact the air quality inthe CSA. Geographyffopography: There are no special geography ortopography issues to consider inthis region.
Jurisdictional Boundaries: The existing 1997 8-hour ozone standard nonattainment area does not include Stanly County and it is not included inNorth Carolina's recommendations for nonattainment areas under the 2008 8-hour ozone standard.
Level ofcontrol ofemissions sources: Stanly County currently has one major VOC point source and no majorNOx sources. SinceNorth Carolinais NOx limited with respect to ozone formation, controlling man-made VOC sources does not reduce ozone concentrations. Therefore, the level ofcontrol for this VOC source should not be of consideration for nonattainment boundary designation. Mobile sources are another source ofNOx emissions. The combined Federal and state control programs for mobile sources address these emissions. Stanly CoUnty does not currently have an OBD based 11M program, but requires an annual visual inspection ofemissions equipment. Low-sulfur gasoline is required statewide.

15