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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 

### September29,2010 Technical SupportDocument for Notice of Proposed Rulemaking -Rome, Georgia nonattainmentArea: Determination of Attaining Data for the 1997 Annual Fine Particulate Matter Standard Sara Waterson, Environmental Scientist 

### ju3 Regulatory DevelopmentSection File Lynorae Benjamin Chief, Regulatory Development Section



### A. 

### BACKGROUND On July 18, 1997(62FR 36852),EPA established an annual fineparticulate 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 (referredto as the 1997 PM2.s NAAQS)


## . At that time, EPA alsoestablished a 24-hourPM2.5 standard of 65 pg/m3. See 40 CFR 50.7. OnJanuary 5,2005 (70FR 944),EPA published its air 

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

### quality monitoring data from those monitors for calendar years 2001-2003. These designations became effectiveon April 5,2005. The Rome Area (comprised of Floyd County in Georgia) was designated nonattainment for the 1997PM2.5 NAAQS. See 40 CFR 81.311.
On October 17,2006(71FR 61144),EPA retained the 1997annual PM2.5NAAQS at 15.0 pg/m3based on a 3-year average of annual mean PM2.5 concentrations, and established a new 24-hourPM2.5 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 attainmentfor the new 24-hourPM2.5 standard. 

### B. EPA REQUIREMENTS A nonattainment area for the 1997PM2.5NAAQS is determined to have attaining data when the design value1for the annual standardmeets 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 (referredto as the "annualstandard design value "). 

### (See40 CFR part 50 Appendix N.)

Internet Address (URL) http:llww.epa.gov RecycledlRecyclable Pr~nted wlth Vegetable 011 Based Inks on Recycled Paper (Minlrnum 30% Postconsumer)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 secondaryPM2.5 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 determinationby 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 furtherprogress plans, contingency measures, and other planning state implementation plan (SIPS)related to attainment of the PMz.5NAAQS 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 requirementto submit suchplans is reinstated. 

### C. EPA'S ANALYSIS OF MONITOREDDATA This technical support document provides information in support of EPA's proposed rulemaking which preliminarilymakes the determination that the Rome Area has attained the 1997PMz.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 measuredby 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 PM25Design 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
14.6The first and second quarters of 2008 were incomplete with around 73percent 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 substituted42.9 @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, 13-115-0005was relocated to site 13-115-0003. 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 1997PM2.5 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. CONCLUSIONSAND 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 15pg/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.