nEQ ST+ d B 

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DATE: 

SUBJECT: 

FROM: 

TO: 

THRU: 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 4 

ATLANTA FEDERAL CENTER 

61 FORSYTH STREET 

ATLANTA, GEORGIA 30303-8960 

September 29,2010 

Technical Support Document for Notice of Proposed Rulemaking -Rome, 

Georgia nonattainment Area: Determination of Attaining Data for the 1997 

Annual Fine Particulate Matter Standard 

Sara Waterson, Environmental Scientist ju3 

Regulatory Development Section 

File 

Lynorae Benjamin 

Chief, Regulatory Development Section 

A. BACKGROUND 

On July 18, 1997 (62 FR 36852), EPA established an annual fine particulate matter 

(PM2.5) national ambient air quality standard (NAAQS) at 15.0 micrograms per cubic meter 

(pg/m3) based on a 3-year average of annual mean PM2.5 concentrations (referred to as the 1997 

PM2.s NAAQS) . At that time, EPA also established a 24-hour PM2.5 standard of 65 pg/m3. 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 Rome Area (comprised of Floyd County in Georgia) was designated nonattainment for the 

1997 PM2.5 NAAQS. See 40 CFR 8 1.3 1 1. 

On October 17,2006 (71 FR 61 144), EPA retained the 1997 annual PM2.5 NAAQS at 

15.0 pg/m3 based on a 3-year average of annual mean PM2.5 concentrations, and established a 

new 24-hour PM2.5 standard of 35 pg/m3. On November 13,2009, EPA clarified the 

designations for the NAAQS promulgated in 1997, stating that the Rome Area was designated as 

nonattainment for the annual standard but attainment for the new 24-hour PM2.5 standard. 

B. EPA REQUIREMENTS 

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

when the design value1 for the annual standard meets the requirements stipulated in 40 CFR Part 

' 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 for a 

single monitoring site or a group of monitoring sites (referred to as the "annual standard design 

value "). (See 40 CFR part 50 Appendix N.) 

Internet Address (URL) http:llww.epa.gov 

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when the design value' for the annual standard meets the requirements stipulated in 40 CFR Part 

50, section 50.13 as follows: 

The annual primary and secondary PM2.5 standards 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 Clg/m3. 

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

has attained the standard, 40 CFR section 5 1.1004(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 state 

implementation plan (SIPS) related to attainment of the PMz.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 

This technical support document provides information in support of EPA's proposed 

rulemaking which preliminarily makes the determination that the Rome Area has attained the 

1997 PMz.5 NAAQS. EPA's determination that the Rome Area has attaining data for the 1997 

PMz.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 monitor and data used to determine the 2007-2009 annual PMz.5 design value 

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

' 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 for a 

single monitoring site or a group of monitoring sites (referred to as the "annual standard design 

value "). (See 40 CFR part 50 Appendix N.) 

2 

Annual PM25 Design Values for the Monitor in the Rome Nonattainment Area 

Location 

Without data 

substitution 

With data 

substitution 

2007 

Average 

@dm3) 

15.7 

15.7 

AQS site ID 

13- 115-0003 

13-1 15-0003 

2008 

Average 

(pg/m3) 

13.0 

16.7 

2009 

Average 

@dm3) 

11.3 

11.3 

2007-2009 

Design 

Value 

(clg1m3> 

13.3 

14.6 
The first and second quarters of 2008 were incomplete with around 73 percent 

completeness each. Data substitution, as described in 40 CFR part 50, Appendix N, was used to 

make a complete record. Data substitution is performed by taking the quarterly maximum 

concentration for the corresponding quarter, using years 2007 - 2009, and substituting that max 

value for the missing concentration. The first quarter of 2008 substituted 42.9 @m3 for the 

missing concentrations. This maximum concentration was recorded in the first quarter of 2009. 

The second quarter of 2008 substituted 37 pg/m3 for the missing concentrations. This maximum 

concentration was recorded in the second quarter of 2007. 

In March 2009, 13-1 15-0005 was relocated to site 13-1 15-0003. The design value is a 

combined monitor record. In the 2009 Ambient Air Monitoring Plan, Georgia Environmental 

Protection Division (GA EPD) stated that the monitor was consolidated with 13-1 15-0003. The 

plan was approved by Region 4 on October 7,2009. The average concentration for the most 

recent three years of available data, i.e., 2007 through 2009, with data substitution was 14.6 

pg/m3. This average concentration is consistent with attainment of the 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, this 

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 that is available to date. For the site, the average of available 2010 data is below 

the NAAQS. Therefore, the available data for 2010 are consistent with the finding, based on 

2007-2009 data, that the Rome 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. EPA is soliciting public comments on the issues discussed in this document through a 

proposed rulemaking. Any comments, if any are received, will be considered before final action 

is taken. 

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 Rome PM2.5 nonattainment Area is 14.6 yg/m3. 

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

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

attaining data for the 1997 annual PM2.5 NAAQS.