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Indiana

Area Designations for the

2008 Ozone National Ambient Air Quality Standards

SUMMARY

EPA has revised the levels of the 8-hour ozone primary (health-based) and secondary 

(environment/welfare-based) National Ambient Air Quality Standards (NAAQS or standards). 

The primary 8-hour ozone standard has been revised from 0.08 parts per million (ppm) to 0.075 

ppm (the 2008 ozone NAAQS). EPA has also revised the secondary ozone standard to be 

consistent with the primary ozone standard in all respects.

 

The table below identifies the areas and associated county in Indiana that EPA intends to 

designate as nonattainment for the 2008 ozone NAAQS.1 In accordance with section 107(d) of 

the CAA, EPA must designate an area (county or part of a county) as “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 the individual 

nonattainment area is provided below.

Table 1. Intended Ozone Nonattainment Areas in Indiana

Area Indiana Recommended 

Nonattainment Counties

EPA’s Intended Nonattainment 

Counties

Nonattainment Area †

Cincinnati-Middletown-Wilmington, 

OH-KY-IN 

None Lawrenceburg Township, Dearborn 

County

† Nonattainment for both primary and secondary 2008 8-hour ozone standards.

Cincinnati-Middletown, OH-KY-IN is a multi-state nonattainment area. Table 2 below identifies 

the counties in other states that EPA intends to designate as part of the nonattainment area.

EPA intends to designate the remaining counties in Indiana that are not listed in the table 

above as “unclassifiable/attainment” for the 2008 ozone NAAQS. 

The analysis below provides the basis for the intended nonattainment area boundaries. It relies 

on our analysis of whether and which monitors are recording violations of the 2008 ozone 

NAAQS, based on certified air quality monitoring data from 2008-2010 and on 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 and 

 1 All other counties in Indiana would be designated as “unclassifiable/attainment” for the 2008 ozone 

NAAQS.
2

other relevant analyses. 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 designation recommendations to EPA.2

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

Method (FRM) or Federal Equivalent Method (FEM) monitor in the area);

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

of emissions and emission controls, and growth patterns);

3. Meteorology (weather/transport patterns);

4. Geography and topography (mountain ranges and other basin boundaries affecting ozone 

levels and ozone precursor transport); and,

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

Indian country, Metropolitan Planning Organization (MPOs) and their covered area).

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

reactions involving Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOC) in the 

presence of sunlight.3 Because NOx and VOC emissions from a broad range of sources over a 

wide area typically contribute to violations of the ozone standards, 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).4 All data 

and information used by EPA in this evaluation are the latest available to EPA and/or provided to 

EPA by states or tribes.

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 and above for the 1-hour ozone standard and EPA used the same approach in the 

designation process for the 1997 ozone NAAQS. Where a violating monitor is not located in a 

CSA or CBSA, EPA’s September 4, 2008 guidance recommends using the boundary of the 

county containing the violating monitor as the starting point for considering the nonattainment 

area’s boundary.

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

3 Peak ozone concentrations generally occur downwind of source areas on relatively sunny days with high 

temperatures and relatively low wind speeds.

4 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).
3

Technical Analysis for Cincinnati-Middletown-Wilmington, OH-KY-IN

Figure 1 is a map of the Cincinnati-Middletown-Wilmington, OH-KY-IN intended 

nonattainment area. The map provides other relevant information, including the locations and 

ozone design values (violating monitors only) of air quality monitors, county and other 

jurisdictional boundaries, existing maintenance boundary for the 1997 ozone NAAQS, 

Cincinnati-Middletown-Wilmington, OH-KY-IN CSA boundary, and major transportation 

arteries. 

Figure 1. Cincinnati-Middletown-Wilmington, OH-KY-IN Area

For purposes of the 1997 ozone NAAQS, as noted in Figure 1, portions of this area were 

designated nonattainment and subsequently redesignated to attainment (maintenance). The 

boundary for the nonattainment area for the 1997 ozone NAAQS included the entire counties of 

Butler, Clermont, Clinton, Hamilton, and Warren in Ohio and Boone, Campbell, and Kenton in 

Kentucky and part of Dearborn County (Lawrenceburg Township) in Indiana.

In March 2009, Ohio recommended that Butler, Clermont, Clinton, Hamilton, and Warren 

Counties be designated as “nonattainment” for the 2008 ozone NAAQS based on air quality data 
4

from 2006-2008. In March 2009, Kentucky recommended that Boone, Campbell, and Kenton 

Counties be designated as nonattainment for the 2008 ozone NAAQS based on air quality data 

from 2006-2008. Additionally, Indiana, in March 2009, recommended that each county in the 

Indiana portion of the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA be designated as 

“attainment” for the 2008 ozone NAAQS. In October 2011, Kentucky submitted an update to 

their 2009 recommendation, and revised their recommendation to “attainment” designations for 

each county in the State.5

The ozone data reflected in Figure 1 and summarized below are from FEM monitors sited and 

operated in accordance with 40 CFR part 58.

After considering these recommendations and based on EPA’s technical analysis described 

below, EPA intends to designate the counties in Ohio and Kentucky and the partial county in 

Indiana identified in Table 2 below as “nonattainment” for the 2008 ozone NAAQS as part of the 

Cincinnati-Middletown-Wilmington, OH-KY-IN nonattainment area.

Table 2. EPA’s Intended Nonattainment Counties for the Cincinnati-MiddletownWilmington, OH-KY-IN Ozone Nonattainment Area

Cincinnati-Middletown-Wilmington, 

OH-KY-IN

State-Recommended Nonattainment 

Counties

EPA Intended Nonattainment 

Counties

Indiana None Dearborn-Partial

Kentucky None Boone

Campbell

Kenton

Ohio Butler

Clermont

Clinton

Hamilton

Warren

Butler

Clermont

Clinton

Hamilton

Warren

Factor Assessment

Factor 1: Air Quality Data

For this factor, we considered 8-hour ozone design values (in ppm) for air quality monitors in 

counties in the Cincinnati-Middleton-Wilmington, OH-KY-IN CSA based on data for the 2008-

2010 period, which are the most recent years with fully-certified air quality data. A monitor’s 

design value is the metric or statistic that indicates whether that monitor attains a specified air 

 5 Letters from Leonard K, Peters, Kentucky Energy and Environmental Cabinet Secretary to A. Stanley Meiburg 

and Gwendolyn Keyes Fleming regarding the initial and updated nonattainment boundary recommendations for the 

2008 8-hour ozone standard for Kentucky(October 13, 2011 and March 12, 2009, respectively); Letter from Chris 

Korleski, Director, State of Ohio Environmental Protection Agency, to Lynn Buhl, Regional Administrator, U.S. 

Environmental Protection Agency, Region 5, regarding initial nonattainment boundary recommendations for Ohio 

for the 2008 ozone NAAQS (March 9, 2009); Letter from Thomas W. Easterly, Commissioner, Indiana Department 

of Environmental Management, to Bharat Mathur, Deputy Regional Administrator, U.S. Environmental Protection 

Agency, Region 5, regarding the initial nonattainment boundary recommendations for the 2008 ozone NAAQS for 

Indiana. 
5

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

daily maximum 8-hour ozone concentrations, averaged over 3 years is 0.075 ppm or less. A 

design values is valid only if minimum data completeness requirements 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 individual design value.

Note: Monitors that are eligible for providing design value data generally include State and Local 

Air Monitoring Stations (SLAMS) that are sited in accordance with 40 CFR Part 58, Appendix D 

(Section 4.1) and operating with a Federal Reference Method (FRM) or Federal Equivalent 

Method (FEM) monitor that meets the requirements of 40 CFR Part 58, Appendix A. All data 

from a Special Purpose Monitor (SPM) using an FRM or FEM which has operated for more than 

24 months is eligible for comparison to the NAAQS unless the monitoring agency demonstrates 

that the data came from a particular period during which the requirements of Appendix A 

(quality assurance requirements) or Appendix E (probe and monitoring path siting criteria) were 

not met.

The 2008-2010 ozone design values for monitors and counties in the Cincinnati-MiddletownWilmington, OH-KY-IN CSA are shown in Table 3.

Table 3. Ozone Air Quality Data for the Cincinnati-Middletown-Wilmington, OHKY-IN CSA

State/County Site Number 2008-2010 8-

hour Ozone 

Design Values 

(ppm)

Ohio:

Butler 390170018 0.078†

Butler 390170004 0.073

Clermont 390250022 0.071

Clinton 390271002 0.074

Hamilton 390610040 0.076†

Hamilton 390610010 0.073

Hamilton 390610006 0.079†

Warren 391650007 0.078†

Kentucky:

Boone 210150003 0.065

Campbell 210373002 0.072

† Monitored violation of the 2008 ozone NAAQS.

Butler, Hamilton, and Warren Counties in Ohio show violations of the 2008 ozone NAAQS. 

Therefore, these counties are included in the intended ozone nonattainment area. 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 based on the weight-of-evidence of the five factors and other 

relevant information to determine whether it contributes to the nearby violation.
6

Please note that the state of Ohio, in its March 9, 2009 area designation recommendations and 

accompanying technical support documentation, based its recommendations on 2006-2008 ozone 

data. Since these data no longer cover the most recent 3-year period with quality-assured, statecertified data and have been supplanted by the more current 2008-2010 ozone data, we are not 

reviewing the older ozone data covered by the state of Ohio.

Factor 2: Emissions and Emissions-Related Data

EPA evaluated emissions for ozone precursors (VOC and NOx) and other emissions-related data 

that provide information on area contributions to ozone standard violations.

Emissions Data

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

Emissions Inventory (NEI), version 1.5. These are the most recently available NEI emissions 

data. (See http://www.epa.gov/ttn/chief/net/2008inventory.html) Significant emission levels in 

a nearby area indicate the potential for the area to contribute to the observed ozone standard 

violation. 

Table 4 shows the 2008 emissions of VOC and NOx (tons per year (tpy)) for all counties in the 

Cincinnati-Middletown-Wilmington, OH-KY-IN CSA. This table also indicates which of the 

counties were recommended to be nonattainment for the 2008 ozone NAAQS by their respective 

states.

Table 4. Total 2008 VOC and NOx Emissions (tons/year) in the Cincinnati-MiddletownWilmington, OH-KY-IN CSA

State/County State Recommended 

Nonattainment?

VOC Emissions

(tpy)

NOx Emissions

(tpy)

Indiana:

Dearborn No 3,572 11,637

Franklin No 1,097 862

Ohio No 210 259

Kentucky:

Boone No 4,332 8,848

Bracken No 361 760

Campbell No 2,260 2,697

Gallatin No 671 1,634

Grant No 1,148 1,623

Kenton No 3,901 4,095

Pendleton No 608 1,394

Ohio:

Brown No 1,720 1,430

Butler Yes 10,813 12,600

Clermont Yes 5,809 28,461

Clinton Yes 2,618 2,941

Hamilton Yes 26,816 38,664

Warren Yes 5,618 6,027

CSA Total 71,554 123,933
7

Emissions Observations by State

Ohio:

From the Ohio emissions data in Table 4, it can be seen that comparatively high 2008 VOC and 

NOx emissions in the vicinity of the violating counties originate in the following counties: 

Butler, Clermont, Hamilton, and Warren. Emissions from these counties in 2008 account for 

68.6 percent of the VOC emissions and 69.2 percent of the NOx emissions for the entire 

Cincinnati-Middletown-Wilmington, OH-KY-IN CSA. 

The VOC and NOx emissions from Brown and Clinton Counties, Ohio are significantly smaller 

than those originating in the higher emitting counties elsewhere in the Cincinnati-MiddletownWilmington, OH-KY-IN CSA. This supports the exclusion of Brown County from the 

recommended ozone nonattainment area for the 2008 8-hour ozone NAAQS, but not the 

exclusion of Clinton County based on consideration of jurisdictional boundaries (see the 

discussion of Factor 5 below).

Indiana:

From the Indiana emissions data in Table 4, it can be seen that comparatively high 2008 VOC 

and NOx emissions in the vicinity of the violating counties originate from Dearborn County. 

Emissions from this county in 2008 account for 5.0 percent of the VOC emissions and 9.4 

percent of the NOx emissions for the entire Cincinnati-Middletown-Wilmington, OH-KY-IN 

CSA. The majority of these emissions come from the American Electric Power (AEP) -

Tanner’s Creek Generating Station located in the Lawrenceburg Township, adjacent to the 

recommended nonattainment area. 

The VOC and NOx emissions from Franklin and Ohio Counties in Indiana are comparatively 

smaller than those originating in the higher emitting counties elsewhere in the CincinnatiMiddletown-Wilmington, OH-KY-IN CSA. This supports the exclusion of these counties from 

the recommended ozone nonattainment area for the 2008 8-hour ozone NAAQS.

Kentucky:

Based on the 2008 NEI, 62 percent of Boone County’s NOx emissions are from point sources, 

and 21 percent of Boone County’s NOx emissions from mobile sources. Less than 5 percent of 

Campbell County’s NOx emissions are from point sources, and 57 percent of Campbell County’s 

NOX emissions are from mobile sources. Kenton County also has less than 5 percent of its NOx 

emission from point sources, but 63 percent of Kenton County’s NOX emissions are from 

mobile sources. Boone County has 29 percent of its VOC emission coming from area sources 

and 23 percent of its VOC emissions from mobile sources. Campbell County has 35 percent of 

its VOC emissions coming from area sources and 43 percent of VOC emissions from mobile 

sources. Kenton County has 38 percent of its VOC emission coming from area sources and 41 

percent of its VOC emissions from mobile sources. 
8

The VOC and NOx emissions from Bracken, Gallatin, Grant, and Pendleton Counties, Kentucky 

are considerably less than those originating in the higher emitting counties elsewhere in the 

Cincinnati-Middletown-Wilmington, OH-KY-IN CSA. This would support the exclusion of 

these counties from the recommended ozone nonattainment area for the 2008 8-hour ozone 

NAAQS.

Population, Population Density, and Degree of Urbanization

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

indicators of the probable location and magnitude of non-point source emissions. These include 

ozone-creating 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 violating ozone monitors. Rapid population or Vehicle Miles Traveled (VMT) 

growth in a county on the urban perimeter signifies increasing integration with the urban core 

area, and indicates that it may be appropriate to include this county in the ozone nonattainment 

area, particularly if this county already has moderate or higher VOC and/or NOx emissions. 

Table 5 shows the 2010 population, population density, and population growth information for 

each county in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA.

Table 5. Population and Population Growth in the Cincinnati-Middletown-Wilmington, 

OH-KY-IN CSA

State/County State 

Recommended 

Nonattainment

2010 

Population

2010 

Population 

Density

(1,000 per 

square mile)

Change in 

Population 

(2000-2010)

Population 

Percent 

Change (2000-

2010)

Indiana:

Dearborn No 50,047 0.16 3,702 +8

Franklin No 23,087 0.06 866 +4

Ohio No 6,128 0.07 492 +9

Kentucky:

Boone No 118,811 0.46 31,811 +37

Bracken No 8,488 0.04 211 +3

Campbell No 90,336 0.57 1,680 +2

Gallatin No 8,589 0.08 705 +9

Grant No 24,662 0.09 2,115 +9

Kenton No 159,720 0.97 8,032 +5

Pendleton No 14,877 0.05 389 +3

Ohio:

Brown No 44,846 0.09 2,263 +5

Butler Yes 368,130 0.78 34,447 +10

Clermont Yes 197,363 0.43 18,733 +10

Clinton Yes 42,040 0.10 1,378 +3

Hamilton Yes 802,374 1.94 -41,916 -5

Warren Yes 212,693 0.52 52,006 +32

Area-wide 2,172,191 0.45 116,914 +6
9

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.STO5&prodType=table)

Population Observations by State

Ohio:

For Ohio, the population data show that Butler, Clermont, Hamilton, and Warren Counties have 

comparatively large populations and population densities and are densely populated. This 

implies that the population-related VOC and NOx emissions in these counties are relatively high. 

In addition, the population change percentages in Butler, Clermont, and Warren Counties 

between 2000 and 2010 exceed the population change percentage for the entire CincinnatiMiddletown-Wilmington, OH-KY-IN area, implying that the population-related emission 

contributions from these counties are increasing compared to those from other counties in the 

Cincinnati-Middletown-Wilmington, OH-KY-IN area.

Indiana:

The populations of the Indiana counties in the Cincinnati-Middletown-Wilmington, OH-KY-IN 

CSA are smaller than those of the Ohio counties and larger Kentucky counties in this CSA, but 

Dearborn County has a moderate population implying moderate population-related VOC and 

NOx emissions. In addition, the population change percentage change from 2000 to 2010 in 

Dearborn County is greater than the population change percentage for the entire CincinnatiMiddletown-Wilmington, OH-KY-IN CSA, implying that the population-related emission 

contribution from this county may be increasing relative to those from other counties in the 

Cincinnati-Middletown-Wilmington, OH-KY-IN area. Ohio County, Indiana also has a greater 

population change percentage as well, but the lower population in this county causes this change 

to be less significant.

Kentucky:

For Kentucky, Boone, Campbell, and Kenton Counties have relatively high populations and 

population densities when compared to the rest of the CSA. Bracken, Gallatin, Grant and 

Pendleton Counties are smaller when compared to the counties included in the non-attainment 

recommendation. Boone County at 37 percent growth and Warren County at 32 percent growth 

had the highest percentage of population growth for any of the counties in the CincinnatiMiddletown-Wilmington CSA. Other counties in this CSA did not have as large of a population 

percentage change, with their growth rates ranging from a 2 to 10 percent increase. Hamilton

County population decreased by 5 percent from 2000-2010.

Traffic and Commuting Patterns

EPA evaluated the total VMT for each county in the Cincinnati-Middletown-Wilmington, OHKY-IN CSA. In combination with the population/population density data and the location of 

main transportation arteries (see above area map), this information helps identify the probable 
10

location of non-point source emissions. A county with high VMT is generally an integral part of 

an urban area and indicates the presence of relatively high motor vehicle emissions that may 

significantly contribute to ozone formation and transport that contributes to nonattainment in the 

urban area. Rapid population or VMT growth in a county on the urban perimeter signifies 

increasing integration with the core urban area, and suggests that this county should be included 

in the ozone nonattainment area, particularly if the VOC and/or NOx emissions in this county are 

a significant portion of the total emissions in the nonattainment area.

Table 6 shows the traffic levels, total 2008 VMT, in each county in the Cincinnati-MiddletownWilmington, OH-KY-IN CSA.

Table 6. Traffic Levels in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA

State/County State 

Recommended 

Nonattainment

2008 VMT*

(million miles)

Indiana:

Dearborn No 904

Franklin No 316

Ohio No 63

Kentucky:

Boone No 1,095

Bracken No 89

Campbell No 1,005

Gallatin No 278

Grant No 432

Kenton No 1,669

Pendleton No 182

Ohio:

Brown No 413

Butler Yes 2,469

Clermont Yes 1,464

Clinton Yes 655

Hamilton Yes 7,391

Warren Yes 1,640

Area-wide 20,063 * MOBILE model VMT are those input into the NEI version 1.5 use to compute the mobile 

source portion of the NEI emissions summarized above in Table 4.

VMT Observations by State

Ohio:

For Ohio, the VMT data show that VMT levels in Butler, Clermont, Hamilton, and Warren 

Counties are comparatively higher than those in Brown and Clinton Counties and, 

accumulatively, are a significant portion of the total VMT for the Cincinnati-MiddletownWilmington, OH-KY-IN CSA.
11

Indiana:

For Indiana, the data show that VMT level in Dearborn County is a comparatively high portion 

of the total VMT for the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA.

Kentucky:

The VMT data show that VMT levels in Boone, Campbell, and Kenton Counties are larger than 

those in Bracken, Gallatin, Grant, and Pendleton Counties and, accumulatively, are a large 

portion of the total VMT for the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA.

Additional Emissions-Related Data Discussed in Indiana’s March 11, 2009 Designation 

Recommendation Submittal

Indiana provided additional information about the controls for the American Electric Power 

(AEP) - Tanner’s Creek Generating Station. Due to a consent decree, three of the four electric 

generating units have applied non-catalytic reduction systems. The plant as a whole is also 

controlled by low NOx burner technology. This shows that there are some controls in place for 

the facility. Indiana provided emissions date from point sources for 2005 by county. Of the 

three counties in Indiana considered in this area, Dearborn County contributed 100% of the point 

source emissions for NOx and VOC. Indiana also provided additional information about 

commuter data that should 13.9% of the Dearborn County workforce was from outside counties 

(3,178 workers in 2006) and 39.8% of the Dearborn County labor force works outside of the 

county, mostly in Ohio (8,895 workers in 2006) and Kentucky (2,111 workers in 2006). 

Factor 3: Meteorology (Weather/Transport Patterns)

EPA evaluated available meteorological data to help determine how meteorological conditions, 

particularly transport conditions, affect the fate and transport of ozone and ozone precursors 

contributing to ozone formation in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA. 

The wind direction percentages show that there is no “preferred” wind direction during the 

summertime. Transport winds can and do blow from all directions into the counties with the 

recorded violations of the 2008 ozone NAAQS. There is, however, an indication that winds 

from south-southwest and west-southwest (collectively, the southwest quadrant) may be more 

prevalent than winds from other wind directions during the summertime in all three ozone 

standard violation counties.

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

The Cincinnati-Middletown-Wilmington, OH-KY-IN 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 we identified the general area that we anticipated we would recommend as nonattainment 

for the 2008 ozone NAAQS, we then considered existing jurisdictional boundaries for the 

purposes of providing a clearly defined legal boundary and to help identify the area appropriate 

for carrying out the air quality planning and enforcement functions for an ozone nonattainment 

area. Examples of jurisdictional boundaries include existing/prior nonattainment boundaries for 

ozone or other urban-scale pollutants, county boundaries, air district boundaries, township 

boundaries, areas covered by metropolitan planning organizations, state lines, and Reservation 

boundaries. Where existing jurisdictional boundaries are not adequate or appropriate to describe 

the nonattainment area, other clearly defined and permanent landmarks or geographic 

coordinates may be considered.

The Cincinnati-Middletown-Wilmington, OH-KY-IN area has previously established 

nonattainment boundaries associated with the both the 1-hour ozone and 1997 8-hour ozone 

NAAQS. The Cincinnati nonattainment boundary for the 1-hour ozone NAAQS included 

Boone, Campbell and Kenton Counties in their entireties in Kentucky; Butler, Clermont, 

Hamilton and Warren Counties in their entireties in Ohio. Whereas the Cincinnati nonattainment 

boundary for the 1997 8-hour ozone NAAQS included Boone, Campbell and Kenton Counties in 

their entireties in Kentucky, Butler, Clermont, Clinton, Hamilton and Warren Counties in their 

entireties in Ohio, and a portion of Dearborn County (Lawrenceburg Township) in Indiana. 

Kentucky and Indiana have recommended a different nonattainment boundary for the 2008 

ozone NAAQS for their portion of this area. Ohio recommended the same boundary as the 1997 

ozone NAAQS nonattainment boundary for their portion of this area. With the exception of 

those counties (and partial county) that comprise the 1997 8-hour ozone boundary for this area, 

we believe that the remainder of the counties in the CSA do not contribute to the violations at the 

monitors in this area and, therefore, are not necessary for consideration as part of the 

nonattainment area.

Conclusion

Ohio:

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

following Ohio counties should be included in the Cincinnati-Middletown-Wilmington, OH-KYIN ozone nonattainment area because they are either violating the 2008 ozone NAAQS or 

contributing to a violation of the 2008 ozone NAAQS within this preliminary nonattainment 

area: Butler; Clermont; Clinton; Hamilton; and, Warren.

Table 8a summarizes which factors, discussed above, support the inclusion of each Ohio county 

in the intended nonattainment area for the 2008 ozone NAAQS. Note that Table 8a covers all 

Ohio counties in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA, but that not all of 

these counties are included in the preliminary nonattainment area for the 2008 ozone NAAQS.
13

Table 8a. Factors Supporting Inclusion of Ohio Counties in the Cincinnati-MiddletownWilmington, OH-KY-IN Ozone Nonattainment Area for the 2008 Ozone NAAQS

County Violates Ozone 

Standard

High Emissions 

Population and 

Traffic Levels 

Meteorology

Favors 

Emissions 

Impact on 

Violating 

Monitor

Geography 

Favors High 

Ozone or 

Emissions

Impact on 

Violating 

Monitor

Jurisdictional

Basis for Inclusion 

In 

Nonattainment 

Area

Butler X X X NA X

Clermont X X NA X

Clinton X NA X

Hamilton X X X NA X

Warren X X X NA X

The results in the above table show that Butler, Hamilton, and Warren Counties, at minimum, 

should be included in the ozone nonattainment area based on air quality data. In addition, these 

counties also have comparatively high VOC and NOx emissions, populations (high populationrelated emissions), and traffic levels (traffic-related emissions), which favor their inclusion in the 

ozone nonattainment area.

Clermont County has comparatively high VOC and NOx emissions and relatively high 

populations and traffic levels, which, based on meteorological considerations, can also contribute 

to the monitored ozone standard violations in EPA’s intended ozone nonattainment area. 

Therefore, Clermont County should also be included in the preliminary ozone nonattainment 

area.

Clinton County has no monitored ozone standard violations and generally lacks the higher VOC 

and NOx emissions and high population and traffic levels of the other Ohio counties discussed 

above. Therefore, these factors do not favor the inclusion of Clinton County in the intended 

ozone nonattainment area. However, it is noted that Clinton County has historically been 

included in the Cincinnati ozone nonattainment area for the 1997 ozone NAAQS. In addition, 

the State of Ohio, in its March 9, 2009 ozone designation submittal, has recommended that 

Clinton County should be included in the ozone nonattainment area for the 2008 ozone NAAQS. 

Based on the jurisdictional factor and the State’s recommendation, we are including Clinton 

County in the intended, preliminary Cincinnati-Middletown-Wilmington, OH-KY-IN ozone 

nonattainment area for the 2008 ozone NAAQS.

Finally, it is noted Brown County lacks ozone standard violations, and the comparatively high 

emissions, populations, and traffic levels of other Ohio counties in the Cincinnati-MiddletownWilmington, OH-KY-IN CSA. In addition, this county was not included in the nonattainment 

area for the 1997 ozone NAAQS and Ohio has not recommended the inclusion of this county in 

the ozone nonattainment area for the 2008 ozone NAAQS. Based on all of these factors and 

facts, we are not including Brown County in the intended Cincinnati-Middletown-Wilmington, 

OH-KY-IN ozone nonattainment area for the 2008 ozone NAAQS.
14

Indiana:

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

following Indiana county should be included in the Cincinnati-Middletown-Wilmington, OHKY-IN ozone nonattainment area because they are either violating the 2008 ozone NAAQS or 

contributing to a violation of the 2008 ozone NAAQS within this preliminary nonattainment 

area: Lawrence Township in Dearborn County.

Table 8b summarizes which factors, discussed above, support the inclusion of each Indiana 

county in the intended nonattainment area for the 2008 ozone NAAQS. Note that Table 8b 

covers all Indiana counties in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA, but that 

not all of these counties are included in the preliminary nonattainment area for the 2008 ozone 

NAAQS.

Table 8b. Factors Supporting Inclusion of Indiana Counties in the Cincinnati-MiddletownWilmington, OH-KY-IN Ozone Nonattainment Area for the 2008 Ozone NAAQS

County Monitored 

Violation for 

Ozone 

Standard

High 

Emissions 

Population and 

Traffic Levels 

Meteorology 

Favors Emissions 

Impact on 

Violating Monitor

Geography Favors 

High Ozone or 

Emissions Impact on 

Violating Monitor

Jurisdictional 

Basis for Inclusion 

In Nonattainment 

Area

Dearborn 

- Partial X X NA X

EPA has preliminarily concluded that Franklin and Ohio Counties are not expected to contribute 

to the ozone standard violations in the recommended Cincinnati-Middletown-Wilmington, OHKY-IN ozone nonattainment area. The areas are mostly rural with no point source emissions and 

minimal amounts of nonpoint source and mobile emissions. Franklin and Ohio Counties were 

not included in the Cincinnati ozone nonattainment area for the 1997 ozone NAAQS. EPA has 

preliminarily concluded that Franklin and Ohio Counties are to be excluded from the proposed 

nonattainment area. 

Lawrenceburg Township in Dearborn County contains the American Electric Power (AEP) –

Tanner’s Creek Generating Station and has high NOx and VOC emissions. Dearborn County 

also has the potential to have moderate mobile source and population related VOC and NOx 

emissions. The inclusion of Lawrenceburg Township in the Cincinnati-MiddletownWilmington, OH-KY-IN ozone nonattainment area would be consistent with the ozone 

nonattainment area for the 1997 ozone NAAQS. Lawrenceburg Township contains the only 

major stationary source in the Indiana portion of Cincinnati-Middletown-Wilmington, OH-KYIN CSA and accounts for the majority of the VOC and NOx emissions in the Indiana portion of 

this area. The remainder of Dearborn County is fairly rural and is similar to Franklin and Ohio 

Counties. The inclusion of the Lawrenceburg Township portion of Dearborn County, Indiana in 

the intended Cincinnati-Middletown-Wilmington, OH-KY-IN nonattainment area for the 2008 

ozone NAAQS is sufficient to account for the contribution of this county.
15

Kentucky:

Table 8c summarizes which factors discussed above support the inclusion of Kentucky counties 

in the intended nonattainment area for the 2008 ozone NAAQS. Note that Table 8c covers all 

Kentucky counties in the Cincinnati-Middletown-Wilmington, OH-KY-IN CSA, but that not all 

of these counties are included in the preliminary nonattainment area for the 2008 ozone NAAQS.

Table 8c. Factors Supporting Inclusion of Kentucky Counties in the CincinnatiMiddletown-Wilmington, OH-KY-IN Ozone Nonattainment Area for the 2008 Ozone 

NAAQS

County Monitored 

Violation 

for Ozone 

Standard

High 

Emissions 

Population and 

Traffic Levels 

Meteorology 

Favors Emissions 

Impact on 

Violating Monitor

Geography Favors 

High Ozone or 

Emissions Impact on 

Violating Monitor

Jurisdictional 

Basis for Inclusion 

In Nonattainment 

Area

Boone X X NA X

Campbell X X NA X

Kenton X X NA X

For Kentucky, based on the assessment of factors described above, EPA has preliminarily 

concluded that the following counties, Boone, Campbell and Kenton, should be included as part 

of the Cincinnati-Middletown-Wilmington nonattainment area because they are contributing to a 

violation in a nearby area. Source category emissions data indicate that mobile sources and area 

sources are not the primary contributors of NOx to ozone formation in the CincinnatiMiddletown -Wilmington area. The analysis reveals that mobile emissions make up 

approximately 28 percent of the total NOx in the Cincinnati-Middletown-Wilmington area, and 

area sources make up approximately 12 percent of the total NOx emissions in the CincinnatiMiddletown -Wilmington area. The total of mobile sources and area sources make up 

approximately 40 percent of the total NOx emissions in the Cincinnati area. However, VOC 

emissions in Cincinnati-Middletown-Wilmington area are high for area and mobile sources. The 

analysis reveals that mobile emissions make up approximately 37 percent of the total VOC in the 

Cincinnati-Middletown-Wilmington area, and area sources make up approximately 38 percent of 

the total VOC emissions in the Cincinnati area. The total of mobile sources and area sources 

make up approximately 75 percent of the total VOC emissions in the Cincinnati-MiddletownWilmington area. Point sources in the area make up approximately 50 percent of the total NOx 

emissions and approximatley10 percent of the total VOC emissions in the CincinnatiMiddletown-Wilmington Area.

Boone, Campbell, and Kenton counties’ NOx and VOC precursor emissions, high VMT along 

with population growth suggest that these counties should be considered for inclusion in the 

Cincinnati-Middletown-Wilmington, OH-KY-IN ozone nonattainment area.