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Cleveland-Akron-Lorain, Ohio

Area Designations for the 

2008 Ozone National Ambient Air Quality Standards

Summary

The table below identifies the areas in Ohio that EPA is designating as “nonattainment” for the 

2008 8-hour ozone National Ambient Air Quality Standard (NAAQS)1as part of the ClevelandAkron-Lorain, Ohio (OH) nonattainment area. In accordance with section 107(d) of the Clean 

Air Act (CAA), EPA must designate an area (county or part of a county) as “nonattainment” if it 

is violating the 2008 8-hour ozone NAAQS, or if it is contributing to a violation of the 2008 

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

nonattainment area is provided below.

Table 1. Areas in Ohio Included in the Cleveland-Akron-Lorain, OH Ozone 

Nonattainment Area

Area Ohio Recommended 

Nonattainment Counties

EPA’s Nonattainment 

Counties

Cleveland-Akron-Lorain, OH Ashtabula

Cuyahoga

Geauga

Lake

Lorrain

Medina

Portage

Summit

Ashtabula

Cuyahoga

Geauga

Lake

Lorrain

Medina

Portage

Summit

EPA is designating as “unclassifiable/attainment” for the 2008 8-hour ozone NAAQS the 

remaining counties in Ohio that are not included in the table above or in the Cincinnati, OH-KYIN or Columbus, OH nonattainment areas (see separate Technical Support Documents for these 

areas).

The analysis below provides the basis for the Cleveland-Akron-Lorain, OH nonattainment area 

boundary. 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. 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 The primary 8-hour ozone standard, set to protect human health was revised on March 27, 2008 (73 FR 16436) 

from 0.08 parts per million (ppm) to 0.075 ppm. The secondary ozone standard, set to protect human welfare and 

the environment, was revised to be consistent with the primary ozone standard.

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 
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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.

Technical Analysis for Cleveland-Akron-Lorain, OH

Figure 1 is a map of the Cleveland-Akron-Lorain, OH ozone nonattainment area for the 2008 

ozone NAAQS. The map provides other relevant information, including the locations and ozone 

design values of air quality monitors recording violations of the 2008 ozone NAAQS, county and 

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

Cleveland-Akron-Elyria, OH CSA boundary and major transportation arteries.

 

emissions-related 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).
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Figure 1. Cleveland-Akron-Lorain, OH 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 all Ohio counties in 

the Cleveland-Akron-Elyria, OH CSA. In March 2009, Ohio recommended that the same 

counties in Ohio be designated as nonattainment for the 2008 ozone NAAQS based on air quality 

data from 2006-2008. These data are from 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 is designating the same 8 counties in Ohio (identified in Table 9 below) as 

“nonattainment” for the 2008 ozone NAAQS for the Cleveland-Akron-Lorain, OH 

nonattainment area.

Factor Assessment

Factor 1: Air Quality Data
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For this factor, we considered 8-hour ozone design values for air quality monitors in counties in 

the Cleveland-Akron-Elyria, OH CSA based on data for the 2008-2010 period, which are the 

most recent years with fully-certified air quality data. As discussed above, a monitor’s design 

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

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 value 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.

The 2008-2010 ozone design values for ozone monitors in the Cleveland-Akron-Elyria, OH CSA 

are shown in Table 2.

Table 2. Ozone Air Quality Data for the Cleveland-Akron-Elyria, OH CSA

County Site Number 2008-2010 8-

Hour Ozone 

Design 

Values 

(ppm)

Ashtabula 390071001 0.077†

Cuyahoga 390350064 0.068

Cuyahoga 390350034 0.075

Cuyahoga 390355002 0.075

Geauga 390550004 0.077†

Lake 390850003 0.076†

Lorain 390930018 0.070

Medina 391030004 0.070

Portage 391331001 0.067

Summit 391530020 0.075

† Monitored violation of the 2008 ozone NAAQS.

From Table 2, it can be seen that Ashtabula, Geauga, and Lake Counties in Ohio show violations 

of the 2008 ozone NAAQS for the period of 2008-2010. Therefore, these counties must be 

included in the ozone nonattainment area. As noted above, a county (or partial county) must also 

be designated nonattainment if it contributes to an air quality standard violation in a nearby area. 

Each county in the Cleveland-Akron-Elyria, OH CSA has been evaluated, as discussed below, 

based on the five factors summarized above and other relevant information to determine whether 

it contributed to the violations of the 2008 ozone NAAQS in Ashtabula, Geauga, and Lake 

Counties.

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

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

ozone data. Since these data no longer cover the most recent 3-year period with quality-assured, 
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state-certified 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 VOC and NOx and other emissions-related data (primarily county 

population, population density, and traffic levels, and projected growth rates for county 

populations) that provide information on area contributions to local ozone standard violations.

Emissions Data

EPA evaluated county-level emission data for NOx and VOC derived from the 2008 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 3 shows the 2008 emissions of NOx and VOC (tons per year) for all counties in the 

Cleveland-Akron-Elyria, OH CSA. This table also indicates which of the counties were 

recommended to be nonattainment for the 2008 ozone NAAQS by the State of Ohio.

Table 3. Total 2008 VOC and NOx Emissions (tons/year) in the Cleveland-Akron-Elyria, 

OH CSA

State/County State Recommended 

Nonattainment?

VOC Emissions

(tpy)

NOx Emissions

(tpy)

Ohio:

Ashtabula Yes 10,411 9,860

Cuyahoga Yes 42,981 38,698

Geauga Yes 3,891 2,237

Lake Yes 10,382 19,286

Lorain Yes 11,646 15,261

Medina Yes 5,918 5,101

Portage Yes 6,137 5,656

Summit Yes 18,699 14,924

CSA Total 110,065 111,022

From the emissions data in Table 3, it can be seen that comparatively high 2008 VOC and NOx 

emissions in the vicinity of the violating counties originate in the following counties: Ashtabula, 

Cuyahoga, Lake, Lorain, and Summit. Emissions from these counties in 2008 account for 85.5 

percent of the VOC emissions and 88.3 percent of NOx emissions for the entire ClevelandAkron-Elyria, OH CSA.

The VOC and NOx emissions from Geauga, Medina, and Portage Counties are significantly 

smaller than those originating in the higher emitting counties within the Cleveland-Akron-Elyria, 
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OH CSA. Note, however, that the collective emissions from these “lower emission” counties 

does constitute 12 to 15 percent of the CSA total emissions. So, even though individual VOC 

and NOx emissions are relatively low in the low emissions counties, their collective emission 

levels are equivalent to the emission levels for counties we are including in the nonattainment 

area for the 2008 ozone NAAQS. On this basis, we conclude that these counties may have the 

potential to contribute to ozone standard violations in the Cleveland-Akron-Lorain, OH 

nonattainment area. 

Population, Population Density, and Degree of Urbanizaion

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 emission 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, which 

can contribute to local and downwind high ozone concentrations. Rapid population or 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 4 shows the 2010 population, population density, and population growth information for 

each county in the Cleveland-Akron-Elyria, OH CSA.

Table 4. Population and Population Growth in the Cleveland-Akron-Elyria, OH 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)

Ohio:

Ashtabula Yes 101,497 0.14 -1,249 -1

Cuyahoga Yes 1,280,122 2.79 -111,989 -8

Geauga Yes 93,389 0.23 2,180 2

Lake Yes 230,041 0.99 2,385 1

Lorain Yes 301,356 0.61 16,224 6

Medina Yes 172,332 0.41 20,496 13

Portage Yes 161,419 0.32 9,036 6

Summit Yes 541,781 1.29 -1,797 0

Area Totals 2,881,937 0.79 -64,714 -2

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&proType=table)
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The population data show that Cuyahoga, Lake, Lorain, Medina, Portage, and Summit Counties 

have comparatively high populations and population densities. This implies that these counties 

are generally urbanized and relatively integrated with the urban core of the Cleveland-AkronElyria, OH CSA. It also implies that the population-related VOC and NOx emissions in these 

counties are comparatively high and contribute to the ozone standard violations in the ClevelandAkron-Lorain, OH ozone nonattainment area. 

The counties that experienced the largest population growth for the 2000-2010 period are Lorain 

and Medina. As noted above, this implies an increasing integration of these counties with the 

urban core of the Cleveland-Akron-Elyria, OH CSA, and favors the inclusion of these counties in 

the ozone nonattainment area.

Although some counties, to the contrary are experiencing population declines (Cuyahoga and 

Summit Counties), their base populations remain high, implying that they should not be excluded 

from the ozone nonattainment area.

Traffic and Commuting Patterns

EPA evaluated the total VMT for each county in the Cleveland-Akron-Elyria, OH CSA. In 

combination with the county-specific population/population density data and the locations of the 

main transportation arteries (see above), this information helps identify the probable locations 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 ozone standard violations in or 

downwind of the urban area. Rapid population or VMT growth in a county on the urban 

perimeter signifies increasing integration with the urban core area, and indicates 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 5 show the traffic levels, 2008 VMT, in each county in the Cleveland-Akron-Elyria, OH 

CSA. 

Table 5. Traffic Levels in the Cleveland-Akron-Elyria, OH CSA

State/County State Recommended 

Nonattainment?

2008 VMT (million miles)

Ohio:

Ashtabula Yes 1,039

Cuyahoga Yes 10,148

Geauga Yes 736

Lake Yes 2,111

Lorain Yes 2,359

Medina Yes 1,532

Portage Yes 1,651

Summit Yes 5,471

Area Total 25,048
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The VMT data show that VMT levels in all counties, with the exception of Geauga County, are 

relatively high. This implies that mobile source emissions in these counties are comparatively 

high and contribute to ozone standard violations in the Cleveland-Akron-Lorain, OH ozone 

nonattainment area.

VMT in Geauga County are comparatively lower than those in other counties in this area. This, 

however, does not imply that this county should be excluded from the ozone nonattainment area 

since this county has a monitored violation of the 2008 ozone NAAQS.

Additional Emissions-Related Data Discussed in Ohio’s March 9, 2009 Designation 

Recommendation Submittal

OEPA has provided typical daily, county-specific total VOC and NOx emissions for 2005 and 

2009 for each of the counties in the Cleveland-Akron-Elyria, OH CSA. These data confirm the 

conclusions we have drawn above using county-specific annual emissions. 

OEPA has provided population projections through 2030 for each of the counties in the CSA. 

These data show significant population growth trends in Geauga, Lake, Lorain, Medina, Portage, 

and Wayne Counties. Populations are projected to be substantially unchanged in Ashtabula and 

Summit Counties through 2030. Populations are projected to decline over time in Cuyahoga 

County, however, the population in this county is projected to remain above 1 million through 

2030.

OEPA provided graphs of daily VMT levels plotted for the period of 1990-2007 for each of the 

counties in the CSA. This visual VMT trend information shows that daily VMT grew 

moderately during the 1990-2007 period for Ashtabula, Cuyahoga, Geauga, Lake, Lorain, 

Medina, Portage, and Summit Counties.

OEPA provided inter-county commuter numbers and percentages for each of the counties in the 

Cleveland-Akron-Elyria, OH CSA. These numbers show a strong inter-county commuting 

pattern throughout the CSA.

Collectively, the OEPA-supplied population and traffic data support the conclusion that all of the 

counties in the Cleveland-Akron-Elyria, OH CSA, with the exception of Ashtabula County, are 

relatively integrated with the urban, industrial core of this area. Therefore, these data support 

including Cuyahoga, Geauga, Lake, Lorain, Medina, Portage, and Summit Counties in the 

Cleveland-Akron-Lorain, OH ozone nonattainment area. As noted elsewhere in this technical 

review, Ashtabula County must be included in this ozone nonattainment area as the result of its 

monitored violation of the 2008 ozone NAAQS.

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 
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contributing to ozone formation in the Cleveland-Akron-Elyria, OH CSA. EPA examined the 

frequency distribution of wind directions for the four seasons of the year by averaging National 

Weather Service direction-sorted wind directions for each county for a 30 year period. To apply 

the results of this data analysis to the Cleveland-Akron-Elyria, OH CSA, we have considered the 

wind direction (direction from which winds are blowing, reflecting directions to potential source 

areas) frequencies during the summer months (June-August) for the three Ohio counties with 

recorded violations of the 2008 ozone NAAQS (See Table 10). Therefore, we have considered 

wind direction distributions for Ashtabula, Cuyahoga, and Geauga Counties in Ohio.

Table 6 shows the summertime 30-year averaged percentages of wind directions (winds blowing 

into the subject county from the specified wind direction sector) for the three ozone standard 

violation counties in the Cleveland-Akron-Elyria, OH CSA.

Table 6. Averaged Summertime Wind Direction Percentages for Ozone Standard 

Violation Counties in the Cleveland-Akron-Elyria, OH CSA

Wind Direction Ashtabula County Geauga County Lake County

North-Northeast 10.1 13.4 14.8

East-Northeast 7.1 6.1 5.5

East-Southeast 8.5 8.3 6.9

South-Southeast 10.1 9.5 9.7

South-Southwest 25.1 24.8 26.8

West-Southwest 15.8 16.6 16.2

West-Northwest 13.2 10.9 10.2

North-Northwest 10.1 10.3 10.0

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

summertime, when the highest ozone concentrations are generally monitored. Transport winds 

can and do blow from all directions in the counties with the recorded violations of the 2008 

ozone NAAQS. There is, however, an indication that winds from the south-southwest and westsouthwest 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 Cleveland-Akron-Elyria, OH 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.

Factor 5: Jurisdictional Boundaries
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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 portion of the Cleveland-Akron-Elyria, OH CSA that we are considering as designating as 

nonattainment for the 2008 ozone NAAQS has a previously established nonattainment boundary 

associated with the 1997 8-hour ozone NAAQS. The State of Ohio has recommended the same 

counties (as included in the 1997 8-hour ozone nonattainment area) in Ohio to be included in the 

boundary of the nonattainment area for the 2008 ozone NAAQS. The prior inclusion of these 

counties in the ozone nonattainment area for the 1997 ozone NAAQS forms the primary 

jurisdictional basis for the inclusion of these counties in the nonattainment area for the 2008 

ozone NAAQS.

Conclusion

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

counties should be included in the Cleveland-Akron-Lorain, OH ozone nonattainment area 

because they are either violating the 2008 ozone NAAQS or are contributing to a violation of the 

2008 ozone NAAQS within this preliminary nonattainment area: Ashtabula; Cuyahoga; Geauga; 

Lake; Lorain; Medina; Portage; and, Summit.

The results in the factor analysis above show that all counties in the Cleveland-Akron-Elyria, OH 

CSA should be included in the Cleveland-Akron-Lorain, OH nonattainment area for the 2008 

ozone NAAQS. Ashtabula, Geauga, and Lake Counties have monitored violations of the 2008 

ozone NAAQS. All counties, except Geauga County, have high emissions or emissions-related 

data (population, population growth, and/or traffic levels) that support inclusion in the 

nonattainment area. Finally, all of these counties are recommended for inclusion in the ozone 

nonattainment area by the State of Ohio and were included in the ozone nonattainment area for 

the 1997 ozone NAAQS.

Based on these factors, we conclude that the entire Cleveland-Akron-Elyria, OH CSA should be 

included in the Cleveland-Akron-Lorain, OH nonattainment area for the 2008 ozone NAAQS.