1

MEMORANDUM

TO: Docket No. EPA

- HQ

- OAR

- 2012

- 0918

Air Quality Designations for the 2012 Fine Particulate ( PM 2.5 ) Standard

FROM: Beth W. Palma

Air Quality Policy Division, OAQPS

SUBJECT: Tennessee Deferred Area Air Quality Designations for the 2012 PM 2.5 National

Ambient Air Quality Standard (SAN 5 706 )

This memorandum provides the rationale for the U.S. Environmental Protection Agency’s

decision to use the additional time available to it under section 107(d)(1)(B) of the Clean Air Act ( CAA) to obtain additional information and further evaluate air quality monitoring data before promulgat ing initial area designations for the 2012 primary annual fine particle National Ambient Air Quality Standard (2012 annual PM 2.5 NAAQS) 1 in certain areas in Tennessee

.

Upon promulgation of a NAAQS, section 107(d) of the CAA requires the EPA to subsequently promulgate area designations based on that NAAQS

. Specifically, EPA must designate as

“nonattainment” those areas that are violating a NA AQS, or that are contributing to a violation of the NAAQS in a nearby area. By contrast, the EPA designates as “unclassifiable/attainment” those areas where air quality monitoring data indicate attainment of the NAAQS, and for areas

that do not have monito rs but which the EPA has reason to believe are likely to be in attainment and are not contributing to nearby violations. Finally, t he EPA reserves the category of

“ unclassifiable ” for areas where the EPA cannot determine based on available information

whet her an area is meeting the NAAQS or contribut ing to a nearby violation.

As described in more detail in the memorandum titled “ Initial Area Designations for the 2012 Revised Primary Annual Final Particle National Ambient Air Quality Standard: Tennessee Dat a Issues

, ” Tennessee ’s monitoring program has experienced data completeness issues for several

areas across the s tate. 2 Given these data completeness issues, for several counties the EPA

cannot calculate a valid design value for the 2011

- 2013 time period ( the data that the EPA is using to determine areas that violate the 2012 annual PM 2.5 NAAQS). Without a valid design value, the EPA has insufficient information to determine whether these areas are meeting or are not meeting the NAAQS. However, t he EPA believes that forthcoming monitoring data will likely result in the three years of complete and valid data needed to assess compliance with the standard and promulgate designations for the areas identified below. Accordingly, the EPA is

defer ring de signation s for these areas, and us ing the additional time available under section

1 On December 14, 2012, the EPA promulgated a revised primary annual PM 2.5 NAAQS (78 FR 3086, January 15, 2013). In that action, the EPA revised the primary annual PM 2.5 standard, strengthening it from 15.0 micrograms per cubic meter (μg/m 3 ) to 12.0 μg/m 3

.

2 Memorandum from Liz Naess, Group Leader, Air Quality Analysis Group, U S EPA Office of Air Quality Planning and Standards , to EPA Docket EPA

- HQ

- OAR

- 2012

- 0918

, Air Quality Designations for the 2012 PM 2.5 Standards

, titled, “ Initial Area Designations for the 2012 Revised Primary Annual Final Particle National Ambient

Air Quality Standard : Tennessee Data Issues

. ”2

107(d)(1)(B) of the C AA to asses s that forthcoming data

, and to promulgate initial area designation s for the identified areas.

The EPA is defer ring designations for all count ies in the s tate of Tennessee with the exception of Hamilton, Marion and Sequatchie counties in the Chattanooga area. Figure 1 displays a map of

the areas. These areas include the listed counties in Tennessee with incomplete monitoring data

that are within these areas, and counties nearby to these Tennessee counties that the EPA believes should be evaluated for potential contribution to the counties with affected data. The

E PA is deferring the designations for all counties in the s tate of Tennessee wi th the exception of Hamilton, Marion and Sequatchie Counties in the Chattanooga area for the 2012 annual PM 2.5 NAAQS to allow the EPA to collect and assess additional information, including air quality monitoring data, before providing the EPA’s intended i nitial area designations for these areas

. There is already sufficient data in the Chattanooga area. The EPA is designating Hamilton, Marion and Sequatchie counties in the Chattanooga area as unclassifiable/attainment.

Figure 1. Map of Tennessee Counties that the EPA is Defer ring

The EPA will work with Tennessee to finalize the designations for these counties as soon as complete certified PM 2.5 monitoring data are available, which the EPA anticipates will allow for3

prompt promulgation of these d esignations . When complete air quality monitoring data are

available and have been certified , the EPA invites the affected states to submit revised designation and boundary recommendations, as appropriate. If at that time the EPA believes that

it is necess ary to modify a state’s recommendation and to promulgate a designation different from the state’s recommendation, then the EPA will notify the state at least 120 days prior to promulgating the final designation and the EPA will provide the state an opportu nity to comment on the potential modification. Each state will then have an opportunity to respond to the EPA’s proposed designations and boundaries. Pursuant to section 107(d), the EPA cannot promulgate the designation for these areas less than 120 days f rom the date of the EPA ’s announced intention to modify the recommendation. The EPA will promulgate the designations for these

deferred areas at a later date, in a separate final rule.

Approach

In determining the appropriate set of neighboring counties to include with the set of monitored counties for which the EPA is deferring designations, the EPA conducted a hypothetical analysis assuming that the monitors with the incomplete data were violati ng the 2012 standard of 12.0 μg/m 3

. The EPA is proceeding under this assumption under the precautionary principle that

because it is unclear whether there is a violation in this area due to data incompleteness, then for purposes of conducting the contribut ion analysis the EPA will presume that there may be such a

violation. The EPA’s contribution analysis for these hypothetical violations focused on counties within the same CBSA as the affected monitor because these counties would be most likely to

contain nearby sources that contribute to any violations. Specifically, the EPA evaluated all

counties in the same C BSA as the county with the monitors in question, in order to determine

whether these presumptively “nearby” counties ( beyond the county with the inc omplete monitoring data) contain emissions sources that would be relatively likely to contribute to any hypothetical violation of the standard in the area with those monitors. Using information similar to the information used for determining nonattainment area boundaries, 3 the EPA e valuated the information available for these CBSAs, including Air Quality Data; Emissions and E missions

related D ata; M eteorology; and G eography/ T opography. 4 One of the EPA’s p rimary boundary

consideration s for determining whethe r to defer a final designation decision for these counties is

whether the agency believes the emissions in those nearby counties are highly likely to

contribute to the potential violations, and whether the meteorological data support a case that

those emis sions could significantly impact the affected monitor. Where available evidence indicates that emissions in adjacent counties could likely have the potential to contribute to monitors with data incompleteness, the EPA is deferring the designation for those counties as well as for the county with the affected monitor.

3 Memorandum dated April 16, 2013

, from Gina McCarthy, Assistant Administrator, to Regional Administrators, Regions 1

- 10, titled “Initial Area Designations for the 2012 Revised Primary Annual Fine Particle National Ambient Air Quality Standard.”

4 The EPA did not consider jurisdictional boundaries for purposes of deferred designations because jurisdictional boundaries are most helpful for nonattainment planning purposes, and this analysis concerns the preliminary dividing line between deferred and unclassifiable/attainment counties. No counties in Tennessee are being designated nonattainment pursuant to this analysis, although that could change in the future if forthcoming data reveal a NAAQS violation.4



### Clarksville TN

- KY Area

Clarksville is located in a bi

- state CBSA that includes four counties: two counties in Tennessee and two counties in Kentucky. Most of the urbanized portion of Clarksvil le is contained within Montgomery County, Tennessee. None of the counties in the CBSA have ever been designated

nonattainment for the 1997 or the 2006 PM 2.5 NAAQS

. The Clarksville CBSA and surrounding counties are shown in Figure 2 , along with the location of point sources and air quality monitors.

Figure 2 . Clarksville CBSA with Point Sources and Air Quality Monitor Locations

There is an attaining monitor in Christian County, Kentucky with a valid design value of 10.3

μ g/m 3 for the 2011

- 2013 timeframe. Also, the PM 2.5 air quality in the area has been steadily improving since the early 2000’s as evidenced by the downward trend of PM 2.5 values measured

at the monitors in the Clarksville area. This downward trend is shown in Fi gure 3 . The Montgomery County, Tennessee monitor has an incomplete de s ign value of 9.6 μ g/m 3 for the

2011

- 2013 timeframe.

Figure 3 . Clarksville Area Air Monitor Design Value (DV) Trends5

The EPA evaluated PM 2.5 and PM 2.5

- precursor emissions 5 and related data from the counties in

the Clarksville area. Table 1 provides a summary of this data. Montgomery and Stewart Counties have the majority of PM 2.5 and precursor emissions, population and VMT. Montgomery County

has a monitor with invalid data and an urbanized core around the City of Clarksville. Stewart County has a large point source (TVA Cumberland Fossil Plant) with over 2,500 tons per year (t py ) of PM 2.5 emissions and over 7,600 tpy of sulfur dioxide ( SO 2 ) emissions in the upwind

direction of the Montgomery County monitor.

In Kentucky, Christian County and Trigg County are outlying areas that are located primarily downwind from the Montgomery County PM 2.5 monitoring site. Christian County has an attaining PM 2.5 monitor, and while the county population is nearly half that of Montgomery County, current growth is only about 3 percent. Trigg County has very low emissions of all pollutants (e.g., 28 tpy of SO 2 and 389 tpy of PM 2.5 ), and the County’s population is rel atively small at about 5 percent for the area.

Table 1 . Summary S tatistics for the Clarksville, TN

- KY CBSA

5 C ounty

- l evel nitrogen oxide, volatile organic compound and ammonia emissions are not shown in the tables with

in this memorandum because ambient PM 2.5 concentrations in the southeastern U.S. tend to be impacted most significantly by emissions of direct PM 2.5 emissions and SO 2 emissions. 0 2 4 6 8 10 12 14 16

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 

### Clarksville DVs

Christian Cty, KY Montgomery Cty, TN - 471251009 2012 PM2.5 NAAQS6 Montgomery Stewart Christian Trigg

State Tennessee Tennessee Kentucky Kentucky

Core urbanized county or outlying? Core Outlying Outlying Outlying

SO2 Emissions (tpy) 1,529 7,740 77 28

PM 2.5 emissions (tpy) 1,018 2,452 947 389

Population 173,375 13,340 74,138 14,355

Population (% of CBSA) 63% 5% 27% 5%

VMT (Millions) 1,467 166 912 218

VMT (% of CBSA) 53% 6% 33% 8%

The EPA also evaluated the meteorology in the area by evaluating wind data collected at the Fort Campbell Airport. Figure 4 provides a wind rose created with five years of data from 2009

- 2013. The predominant winds blow from the southwest and south directi ons. Additionally, there is a low frequency of winds blowing from the northerly directions which limits the potential for transport of emissions from the Kentucky counties into Tennessee

. These wind patterns do not support contribution of emissions from th e Kentucky counties to the PM 2.5 air quality in the

Tennessee areas. Emissions from Montgomery and Stewart counties in Tennessee are most likely to impact the monitor in Montgomery County.7

Figure 4 . Wind Rose Data for the Clarksville TN

- KY Area8

Clarksville Area Conclusion:

As a result of our technical analysis of the Clarksville CBSA, the EPA is deferring the designation s for the Tennessee counties of Montgomery and Stewart along with most of the s tate of Tennessee due to the ambient monitoring data quality issues, including an invalid 2013 design value at the Montgomery County monitor. The EPA agrees with the recommendation from Kentucky for Christian and Trigg Counties in the Clarksville Area and is designating these

counties as unclassifiable /attainment

.



### Kingsport

- Bristol, TN

- VA Area

Kingsport

- Bristol is located in a bi

- state CBSA that includes four counties and a city: two counties in Tennessee and two counties in Virginia, along with Bristol City which straddles the Tennessee and Virginia state line. Most of the urbanized portion of Kingsport

- Bristol is

contained within Sullivan and Hawkins Counties in Tennessee. None of the counties in the CBSA have ever been designated nonattainment for the 1997 or the 2006 PM 2.5 NAAQS. The Kingsport

- Bri stol CBSA and surrounding counties are shown in Figure 5 , along with the location of point sources and air quality monitors.

Figure 5 . Kingsport

- Bristol CBSA with Point Sources and Air Quality Monitor Locations

There is an attaining monitor in Bristol City on the Virginia side of the state line with a valid design value of 9.0 μ g/m 3 for the 2011

- 2013 timeframe. Also, the PM 2.5 air quality in the area9

has been steadily improving since the early 2000’s as evidenced by the downward trend of PM 2.5 values measured at the monitors in the Kingsport

- Bristol area. This downward trend is shown in Figure 6 . The Sullivan County, Tennessee monitor has an incomplete deign value of 9.3 ug/m 3

for the 2011

- 2013 timeframe.

Figure 6 . Kingsport

- Bristol Area Air Monitor DV Trends

The EPA evaluated PM 2.5 and PM 2.5

- precursor emissions and related data from the counties in the Kingsport

- Bristol area. Table 2 provides a summary of this data. Sullivan and Hawkins

Counties have the majority of PM 2.5 and precursor emissions, population and VMT. Hawkins County also has four large point sources in the upwind direction of the Sullivan County monitor, two of which, TVA John Sevier Fossil Plant and Holston Army Ammunition Plant, have signi ficant SO 2 emissions of over 15,000 tpy and over 1,500 tpy, respectively.

In Virginia, Scott and Washington Counties and Bristol City have low emissions, population and VMT relative to Sullivan and Hawkins Counties. These are outlying areas that are locat ed in the primarily downwind direction from the Sullivan County PM 2.5 monitoring site. Bristol City has an attaining PM 2.5 monitor and low population and population growth of about 3 percent. Scott County has very low SO 2 emissions of about 40 tpy and rel atively low PM 2.5 emissions of 306 tpy. Although Scott County has 18 percent of the area’s population, the recent growth trend is negative. Washington County has very low emissions of all pollutants (e.g., 88 tpy of SO 2 and 104 tpy of PM 2.5 ), and the Count y’s population is relatively small at about 6 percent for the area. 0 2 4 6 8 10 12 14 16

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 

### Kingsport DVs

Bristol City, VA Sullivan Cty., TN 2012 PM2.5 NAAQS10

Table 2 . Summary S tatistics for the Kingsport

- Bristol, TN

- VA CBSA

Hawkins Sullivan Bristol City Scott Washington

State Tennessee Tennessee Virginia Virginia Virginia

Core urbanized
county or outlying? Outlying Core Outlying Outlying Outlying

SO2 Emissions (tpy) 17,819 24,937 26 40 88

PM 2.5 emissions (tpy) 892 3,036 946 306 104

Population 56,842 156,866 17,849 23,111 54,879

Population (% of CBSA) 18% 51% 6% 18% 6%

VMT (Millions) 537 1,748 225 275 741

VMT (% of CBSA) 15% 50% 6% 21% 8%

The EPA also evaluated the meteorology in the area by evaluating wind data collected at the Tri

Cities Regional Airport. Figure 7 is a wind rose created from five years of data from 2009

- 2013. The predominant winds blow from the west and southwest directions. Additionally, there is a low frequency of winds blowing from the northerly directions which limits the potential for

transport of emissions from the Virginia counties into Tennessee. These wind patterns do not support contribution of emissions from the Virginia areas to the PM 2.5 air quality in the

Tennessee areas. Emissions from Sullivan and Hawkins counties in Tennessee are mos t likely to impact the monitor in Sullivan County.11

Figure 7 . Wind Rose Data for the Kingsport

- Bristol TN

- VA Area12

Kingsport

- Bristol Area Conclusion:

As a result of our technical analysis of the Kingsport

- Bristol CBSA, the EPA is deferring the desig nations for the Tennessee counties of Sullivan and Hawkins along with most of the State of Tennessee due to the ambient monitoring data quality issues, including an invalid 2013 design value at the Sullivan County monitor. The EPA agrees with the recommendation from Virginia for Scott and Washington Counties and Bristol City in Virginia, and is designating these areas as attainment/unclassifiable. As discussed above, any potential violation at the Sullivan County monitor would be strongly influenced by the point sources in Sullivan and Hawkins County,

Tennessee.



### Memphis TN

- MS

- AR Area

Memphis is located in a tri

- state CBSA that includes nine counties: three counties in Tennessee, five counties in Mississippi, and one county in Arkansas. Most of the urbanized portion of Memphis is contained within Shelby County, Tennessee, although there are pockets of urbanization that stretch into DeSoto County, Mississippi, and Crittenden County, Arkansas.

None of the counties in the CBSA have ever bee n designated nonattainment for either the 1997

or the 2006 PM 2.5 NAAQS. The Memphis CBSA and surrounding counties are shown in Figure

8 , along with the location of point sources and air quality monitors.

Figure 8 . Memphis TN

- MS

- AR CBSA with Point Sources and Air Quality Monitor Locations13

There are attaining monitors in both DeSoto County and Crittenden County with valid design

values for the 2011

- 2013 timeframe of 9.6 μg/m 3 and 10.6 μg/m 3 , respectively. Also, the PM 2.5 air quality in the area has been steadily improving since the early 2000’s as evidenced by the

downward trend of PM 2.5 values measured at all of the monitors in the Memphis area, including the monitors in Shelby County prior to the time when data quality issues caused that data to be unreliable for final regulatory determinations (approximately 2008). This downward trend is shown in Figure 9 . The Shelby County, Tennessee monitor has an incomplete de s ign value of 9.7 ug/m 3 for the 2011

- 2013 timeframe.

Figu re 9 . Memphis Area Air Monitor DV Trends

The EPA evaluated PM 2.5 and PM 2.5

- precursor emissions and related data from the counties in the Memphis area. Table 3 provides a summary of this data. Shelby County has the majority of

PM 2.5 and precursor emissions, population and VMT. Shelby County also has four large sources just 8

- 12 miles upwind of the Shelby County monitor, including Cargill Corn Milling (330 tpy

PM 2.5 and 3,000 tpy SO 2 ) and Allen Fossil Plant (415 tpy PM 2.5 and 11,000 t py SO 2 ) as can be seen in the map of the Memphis area provided in Figure 8

. 0 2 4 6 8 10 12 14 16

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 

### Memphis Area Design Values

PM2.5 NAAQS Shelby, TN-0047 (N.V. since 2008)

Shelby, TN-0014 Shelby, TN-0038

Shelby, TN-1004 Crittenden, AR-0004

Crittenden, AR-0005 DeSoto, MS-000214

Table 3 . Summary S tatistics for the Memphis, TN

- MS

- AR CBSA

Fayette Shelby Tipton Benton Desoto Marshall Tate Tunica Crittenden

State TN TN TN MS MS MS MS MS AR

Core

urbanized
county or outlying? Outlying Core Outlying Outlying Core Outlying Out

lying Outlying Core

SO2

Emissions (tpy) 429 20,010 308 36 52 63 58 107 125

Primary

Sulfate

Emissions (tpy) 10 140 8 10 29 6 6 8 11

PM 2.5 emissions (tpy) 790 4,042 874 475 1,419 1,064 651 1,471 1,854

Population 38,413 928,792 61,160 8,712 161,732 37,098 28,970 10,741 50,952

Population (% of CBSA) 3% 70% 5% 1% 12% 3% 2% 1% 4%

Population growth (2000

– 2010) 33% 4% 19% 9% 51% 6% 14% 16% 0.2%

VMT (Millions) 540 8,562 417 190 1,798 683 365 237 866

VMT (% of CBSA) 4% 63% 3% 1% 13% 5% 3% 2% 6%

The EPA also evaluated the meteorology in the area by evaluating wind data collected at the Memphis International Airport. Figure 10 is a wind rose created from five years of data from

2009

- 2013. The predominant winds blow from the south and southwesterly directions, with a smaller component of winds blowing from the north to the south. These wind patterns suggest the Shelby County moni tor would be impacted by emissions from these large point sources in Shelby County.15

Figure 10 . Wind Rose Data for the Memphis TN

- MS

- AR Area16

In addition, the EPA evaluated speciated PM 2.5 information collected at the Chemical Speciation

Network monito r in the area (Figure 1 1 ). The PM 2.5 speciation data and the derived urban

increment analysis indicate the dominance of different contributing species in each quarter. The peak PM 2.5 concentrations occur during the 3 rd quarter of the calendar year (July

- Se ptember) when sulfate and primary organic matter are the major urban increment components of the PM 2.5 mass. Largely responsible for these peak concentrations are the emissions from Shelby County, which include 20,010 tpy of SO 2 and 140 tpy direct sulfate. By comparison, the Mississippi and Arkansas counties of the CBSA have low overall emissions, and in particular they have

emissions of SO 2 and direct sulfate in the range of just 36 to 125 tpy and 6 to 29 tpy, respectively.

Figure 1 1 . Quarterly Speciated Monitoring and Urban Increment Data for the Memphis Area

Memphis Area Conclusion:

As a result of our technical analysis of the Memphis CBSA, the EPA is deferring designations

for the Tennessee counties of Shelby, Fayette and Tipton along with most of the State of Tennessee due to the ambient monitoring data quality issues, including an invalid 2013 design value at the Shelby County monitor. The EPA is designating Crittenden County , Arkansas, and Benton, DeSoto, Marshall, Tate and Tunica Counties in Mississippi as unclassifiable/attainment, which agrees with the recommendations from Mississippi and represents a slight modification 6 to
the recommendation from Arkansas of attainment f or Crittenden County. As discussed above,

6 In its recommendation letter, Arkansas recommended Crittenden County be designated “attainment.” The EPA is designating Crittenden County “unclassifiable/attainment.”17

any potential violation at the Shelby County monitor would be influenced by the point sources within Shelby County, Tennessee, particularly the much higher level of SO 2 and direct sulfate

emissions relative to the rest of the CBSA.