UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IV

Technical Support Document 

EPA’s Notice of Proposed Rulemaking 

For 

Approval and Promulgation of Air Quality Implementation Plans; Ohio, Kentucky, 

and Indiana; Cincinnati-Hamilton Nonattainment Area; Determination of 

Attainment of the 1997 Annual Fine Particulate Standards

May 2011
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A. BACKGROUND

On July 18, 1997 (62 FR 36852), EPA established an annual PM2.5 NAAQS at 15.0 

μg/m3based on a 3-year average of annual mean PM2.5 concentrations. At that time, EPA also 

established a 24-hour standard of 65 μg/m3(today’s action does not address the 24-hour 

standard). See 40 CFR 50.7. On January 5, 2005 (70 FR 944), EPA published its air quality

designations and classifications for the 1997 PM2.5 NAAQS based upon air quality monitoring 

data from those monitors for calendar years 2001–2003. These designations became effective on 

April 5, 2005. The Cincinnati Area was designated nonattainment for the 1997 PM2.5 NAAQS. 

See 40 CFR 81.336 (Ohio), 40 CFR 81.318 (Kentucky), and 40 CFR 81.315 (Indiana).

On October 17, 2006 (71 FR 61144), EPA retained the annual PM2.5 NAAQS at 15.0 

micrograms per cubic meter (μg/m3) based on a 3-year average of annual mean PM2.5

concentrations. On November 13, 2009, EPA clarified the designations for the NAAQS 

promulgated in 1997, stating that the Cincinnati Area was designated as nonattainment for the 

annual standard. 

B. EPA REQUIREMENTS

A nonattainment area for the 1997 PM2.5 NAAQS is determined to have attaining data 

when the design value1for the annual standard meets the requirements stipulated in 40 CFR Part 

50, section 50.13 as follows:

The annual primary and secondary PM2.5standards are met when the annual arithmetic 

mean concentration, as determined in accordance with appendix N of this part, is less 

than or equal to 15.0 μg/m3.

Upon determination by EPA that an area designated nonattainment for the PM2.5 NAAQS 

has attained the standard, 40 CFR section 51.1004(c) provides that the requirement for such area 

to submit attainment demonstrations and associated reasonably available control measures, 

reasonable further progress plans, contingency measures, and other planning SIPs related to 

attainment of the PM2.5 NAAQS shall be suspended until the area is redesignated to attainment, 

at which time the requirement no longer applies. However, if EPA subsequently determines that 

the area has violated the PM2.5 NAAQS, the requirement to submit such plans is reinstated.

C. EPA’S ANALYSIS OF MONITORED DATA

 

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Design values are the metrics that are compared to the NAAQS levels to determine attainment. The 

annual design value is calculated as the 3-year average of annual means (referred to as the “annual standard design 

value ”). (See 40 CFR part 50 Appendix N.)
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EPA’s determination that the Cincinnati nonattainment Area is attaining the 1997 PM2.5

NAAQS is based upon complete, quality assured, quality controlled and certified ambient air 

monitoring data for the 2007-2009 period, as measured by Federal reference method, Federal 

equivalent method, or Approved Regional Method monitors described in 40 CFR Part 50,

Appendix N. The monitors and data used to determine the 2007-2009 annual PM2.5 design value

for the Cincinnati nonattainment area are included in the table below.

Annual PM2.5 Design Values for Monitors in the Cincinnati Nonattainment Area

Location AQS site ID

2007

98th

Percentile

2008

98

th

Percentile

2009

98th

Percentile

2007-2009

Design 

Value

Verity 39-017-0003 15.4 13.8 12.8 14.0

Sacred Heart School 39-017-0016 14.9 13.8 13.1 13.9

Batavia 39-025-0022 14.0 11.7 11.0 12.3

Sycamore 39-061-0006 14.6 12.5 12.1 13.1

Carthage 39-061-0014 16.6 15.1 13.4 15.0

Taft 39-061-0040 15.1 12.6 12.7 13.5

Lower Price Hill 39-061-0042 15.9 14.4 13.7 14.7

Norwood 39-061-7001 15.1 13.7 13.0 13.9

Murray Rd 39-061-8001 16.1 14.4 13.4 14.6

Lebanon 39-165-0007 14.0 11.9 11.7 12.5

NKU 21-037-3002 14.4 11.8 11.3 12.5

Covington 21-117-0007 14.2 12.0 11.0 12.4

In addition to the sites listed in the table above, two sites, Scarlet Oaks School (39-061-0043) 

and Hook Field Airport (39-017-1004), did not operate for the entire three-year period from 

2007-2009. The first of these two sites, Scarlet Oaks School, discontinued operation after the 

fourth quarter of 2008. The letter approving the Ohio Monitoring Network, dated January 5, 

2010, approved the discontinuation of this monitor and stated that Ohio’s monitoring network 

satisfies the applicable monitoring network requirements for PM2.5. The Scarlet Oaks School site 

monitored an average concentration of 14.8 μg/m3in 2007, and an annual average concentration 

in 2008 of 13.3 μg/m3. The average concentration for the most recent three years of available 

data, i.e., 2006-2008, was 14.2 μg/m3. This average concentration is consistent with attainment 

of the NAAQS. 

The second site, Hook Field Airport, discontinued operation after the fourth quarter of 

2007. Region 5 documented the approval of the closure of the Hook Field Airport site in early

2010 in a letter dated December 21, 2010, to the Hamilton County Department of Environmental 

Services. The site was shut-down due to safety issues in which the monitor was located. The 

Hook Field Airport site monitored an annual average concentration of 14.6 μg/m3for 2007. The 

average concentration for the most recent three years of available data, i.e., 2005-2007, was 15.0

μg/m3. This average concentration is consistent with attainment of the NAAQS.
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The other monitor in the Cincinnati Area that did not collect complete data for 2007-2009

began sampling well after the beginning of this period. The NKU site, site number 21-037-3002, 

was not operational until August 1, 2007. For this site, the average of concentrations in the last 

quarter of 2007 was 14.4 μg/m3, the annual average of concentrations in 2008 was 11.8 μg/m3, 

and the annual average of concentrations in 2009 was 11.3 μg/m3. The average concentration 

using available data in 2007 to indicate 2007 concentrations and using complete data in 2008 and 

2009 is 12.5 μg/m3.

The monitors in the Cincinnati Area that collected complete data for 2007-2009 have average 

concentrations that are all consistent with attainment of the 1997 annual PM2.5 NAAQS. 

Determinations of attainment are based on three years of complete, quality-assured data. 

Nevertheless, any such assessment should consider additional quality-assured data, to the extent 

that quality-assured data exist. In accordance with Appendix N and standard EPA practice, the

review of data is based on the three most recent years of complete data, generally 2007-2009. 

Appendix N does not provide for examining partial years of data, because various seasons of the 

year reflect various influences on PM2.5 concentrations, and a partial year’s data may not be 

representative of values that would be determined from a full year’s data set. Nevertheless, EPA 

examined data from the first half of 2010. The complete year has not been certified; therefore, 

the data are not considered complete for 2010. All of the 2008-2010 design values are below the 

15.0 μg/m3, except for the Murray Road site in Cincinnati. The Murray Road site has a 

preliminary 2008-2010 design value of 15.1 μg/m3; however, the site was shut down in February

of the first quarter of 2010 due to safety issues. Region 5 approved the shut down in a letter 

dated December 21, 2010. The partial first quarter of 2010 data before the monitor shut down

showed the only data above the NAAQS for the 2008-2010 period. The 2008 design value was 

14.4 μg/m3and the 2009 design value was 13.4 μg/m3. Approval was granted for the site to be 

shut down because the Carthage Fire site registered a higher design value and is located 

approximately a mile from the Murray Road site. A comparison of the 2007-2009 data showed 

the sites were well correlated with each other.

The available data for 2010 are consistent with the finding, based on 2007 - 2009 data, 

that the Cincinnati Area is attaining the 1997 annual PM2.5 NAAQS. On the basis of this review, 

EPA has concluded that this area has met and continues to meet the 1997 PM2.5 NAAQS. 

D. CONCLUSIONS AND RECOMMENDED AGENCY ACTION

Quality assured, quality controlled, and certified ambient air monitoring data for 2007-

2009 shows that the design value for the Cincinnati PM2.5 nonattainment Area is 15.0 μg/m3.

Because this value is less than or equal the 1997 annual PM2.5 NAAQS of 15 μg/m3, the area has 

monitored attainment for this NAAQS. I recommend the Cincinnati Area be determined to have 

attaining data for the 1997 annual PM2.5 NAAQS.