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Kentucky-Indiana:

Louisville/Jefferson County

Area Designations for the 

2012 Primary Annual PM2.5 National Ambient Air Quality Standards 

Technical Support Document

1.0 Summary

In accordance with section 107(d) of the Clean Air Act (CAA), the EPA must promulgate designations for all 

areas of the country. In particular, the EPA must identify those areas that are violating a National Ambient Air 

Quality Standard (NAAQS) or contributing to a violation of the NAAQS in a nearby area. The EPA must 

complete this process within 2 years of promulgating a new or revised NAAQS, or may do so within 3 years 

under circumstances not relevant to these designations.1 This technical support document (TSD) describes the 

EPA’s intent to designate areas in Kentucky and Indiana as nonattainment for the 2012 primary annual fine 

particle NAAQS (2012 annual PM2.5 NAAQS).2

Under section 107(d), states are required to submit area designation recommendations to the EPA for the 2012 

annual PM2.5 NAAQS no later than 1 year following promulgation of the standard, or by December 13, 2013. In

December 2013, Kentucky recommended that all counties in the Commonwealth be designated as attainment or 

attainment/unclassifiable. Additionally, in December 2013, Indiana recommended that all monitored counties in 

Indiana be designated attainment and all remaining counties be designated unclassifiable. After considering 

these recommendations and based on the EPA’s technical analysis as described in this TSD, the EPA intends to 

designate the areas listed in Table 1 as nonattainment for the 2012 annual PM2.5 standard. The EPA must 

designate an area nonattainment if it has an air quality monitoring site3that is violating the standard or if it has 

sources of emissions that are contributing to a violation of the NAAQS in a nearby area. Legal descriptions 

(e.g., county boundaries, townships and ranges) of these areas are found below in the supporting technical 

analysis for each area. As provided in CAA section 188(a), the EPA will initially classify all nonattainment 

areas as “Moderate” nonattainment areas.

 

1 Section 107(d) of the CAA requires the EPA to complete the initial designation process within 2 years of promulgation of 

a new or revised NAAQS, unless the Administrator has insufficient information to make initial designation decisions in the 

2-year time frame. In such circumstances, the EPA may take up to 1 additional year to make initial area designation 

decisions (i.e., no later than 3 years after promulgation of the standard).

2 On December 14, 2012, the EPA promulgated a revised primary annual PM2.5 NAAQS (78 FR 3086, January 15, 2013). 

In that action, the EPA revised the primary annual PM2.5 standard, strengthening it from 15.0 micrograms per cubic meter 

(μg/m3) to 12.0 μg/m3.

3

In accordance with 40 CFR 50 Appendix N, PM2.5 measurements from the primary monitor and suitable collocated PM2.5 

Federal Reference Method (FRM), Federal Equivalent Method (FEM) or Approved Regional Methods (ARM) may be used 

in a “combined site data record” to establish a PM2.5 design value to determine whether the NAAQS is met or not met at a 

particular PM2.5 monitoring site.
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Table 1. Kentucky-Indiana Recommended Nonattainment Areas and the EPA’s Intended Designated 

Nonattainment Areas for the 2012 annual PM2.5 NAAQS

Area States’ Recommended 

Nonattainment Counties

The EPA’s Intended 

Nonattainment Counties

Louisville (KY side) None

Jefferson

Bullitt (partial)

Louisville (IN side) None Clark

Floyd

In their recommendation letter, Kentucky recommended that the EPA designate as “attainment” or 

“unclassifiable/attainment” all counties of the Commonwealth. With the exception of a portion of Bullitt 

County, and the entire Jefferson County in Kentucky, as identified in Table 1, and the counties in the Cincinnati 

Area, the EPA agrees with Commonwealth’s recommendation and intends to designate the remainder of

Kentucky as unclassifiable/attainment. This is based on the Commonwealth’s recommendation, ambient

monitoring data collected during the 2011-2013 period showing compliance with the 2012 annual PM2.5

NAAQS, and Kentucky’s determination/assessment that areas within the Commonwealth are not likely 

contributing to nearby violations.

4,5

In their recommendation letter, Indiana recommended that the EPA designate as “attainment” or 

“unclassifiable/attainment” all counties in Indiana. With the exception of Clark and Floyd Counties, as 

identified in Table 1, the EPA agrees with Indiana’s recommendation and intends to designate the remainder of 

Indiana as unclassifiable/attainment based on the State’s recommendation, ambient monitoring data collected 

during the 2011-2013 period showing compliance with the 2012 annual PM2.5 NAAQS, and the 

Commonwealth’s determination/assessment that areas within the Commonwealth are not likely contributing to 

nearby violations.6,7

 

4 Unless a state or tribe has specifically identified jurisdictional boundaries in their area recommendations, when 

determining “remainder of the state,” The EPA will use Federal Information Processing Standard (FIPS) codes maintained 

by the National Institute of Standards and Technology (NIST), which are used to identify counties and county equivalents 

(e.g., parishes, boroughs) of the United States and its unincorporated territories (e.g., American Samoa, Guam, Northern 

Mariana Islands, Puerto Rico, and the US Virgin Islands). Available on the EPA’s Envirofacts website at 

http://www.epa.gov/envirofw/html/codes/state.html.

5 The EPA uses a designation category of "unclassifiable/ attainment" for areas that are monitoring attainment and for areas 

that do not have monitoring sites but which the EPA believes are likely attainment and does not have emissions sources 

that are contributing to nearby violations based on the five factor analysis and other available information.

6 Unless a state or tribe has specifically identified jurisdictional boundaries in their area recommendations, when 

determining “remainder of the state,” EPA will use FIPS codes maintained by the NIST, which are used to identify 

counties and county equivalents (e.g., parishes, boroughs) of the United States and its unincorporated territories (e.g., 

American Samoa, Guam, Northern Mariana Islands, Puerto Rico, and the US Virgin Islands). Available on the EPA’s 

Envirofacts website at http://www.epa.gov/envirofw/html/codes/state.html.

7 The EPA uses a designation category of "unclassifiable/ attainment" for areas that are monitoring attainment and for areas 

that do not have monitoring sites but which the EPA believes are likely attainment and does not emissions sources that are

contributing to nearby violations based on the five factor analysis and other available information.
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2.0 Nonattainment Area Analyses and Intended Boundary Determination

The EPA evaluated and determined the intended boundaries for each nonattainment area on a case-by-case basis 

considering the specific facts and circumstances unique to the area. In accordance with the CAA section 107(d), 

the EPA intends to designate as nonattainment not only the area with the monitoring sites that violate the 2012 

annual PM2.5 NAAQS, but also those nearby areas with emissions sources that contribute to the violation in the 

violating area. As described in the EPA guidance,

8

after identifying each monitoring site indicating a violation 

of the standard in an area, the EPA analyzed those areas with emissions contributing to that violating area by 

considering those counties in the entire metropolitan area (e.g., Core Based Statistical Area (CBSA) or 

Combined Statistical Area (CSA)) in which the violating monitoring site is located. The EPA also evaluated

counties adjacent to the CBSA or CSA that have emissions sources with the potential to contribute to the 

violation. The EPA uses the CBSA or CSA as a starting point for the contribution analysis because those areas 

are nearby for purposes of the PM2.5 NAAQS. Based upon relevant facts and circumstances in each area, the 

designated nonattainment area could be larger or smaller than the CBSA or CSA. The EPA’s analytical 

approach is described in section 3 of this TSD.

3.0 Technical Analysis 

In this technical analysis, the EPA used the latest data and information available to the EPA (and to the states 

and tribes through the PM2.5 Designations Mapping Tool9and the EPA PM Designations Guidance and Data 

web page10) and/or data provided to the EPA by states or tribes. This technical analysis identifies the areas with 

monitoring sites that violate the 2012 annual PM2.5 standard. The EPA evaluated these areas and other nearby 

areas with emissions sources or activities that potentially contribute to ambient fine particle concentrations at 

the violating monitors in the area based on the weight of evidence of the five factors recommended in the EPA 

guidance and any other relevant information.

These five factors are:

Factor 1: Air Quality Data. The air quality data analysis involves examining available ambient PM2.5 air quality 

monitoring data at, and in the proximity of, the violating monitoring locations. This includes reviewing the 

design values (DV) calculated for each monitoring location in the area based on air quality data for the most 

recent complete 3 consecutive calendar years of quality-assured, certified air quality data in the EPA’s Air 

Quality System (AQS). In general, the EPA identifies violations using data from suitable FRM, FEM, and/or 

 

8 The EPA issued guidance on April 16, 2013, that identified important factors that the EPA intended to evaluate, in 

making a recommendation for area designations and nonattainment boundaries for the 2012 annual PM2.5 NAAQS. 

Available at http://www.epa.gov/pmdesignations/2012standards/docs/april2013guidance.pdf.

9 The EPA’s PM2.5 Designations Mapping Tool can be found at http://geoplatform2.epa.gov/PM_MAP/index.html.

10 The EPA’s PM Designations Guidance and Data web page can be found at 

http://www.epa.gov/pmdesignations/2012standards/techinfo.htm.
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ARM monitors sited and operated in accordance with 40 CFR Part 58.

11 Procedures for using the air quality 

data to determine whether a violation has occurred are given in 40 CFR part 50 Appendix N, as revised by a 

final action published in the Federal Register on January 15, 2013 (78 FR 3086).12 In addition to reviewing data 

from violating monitor sites, the EPA also assesses the air quality data from other monitoring locations to help 

ascertain the potential contribution of sources in areas nearby to the violating monitoring site. Examples include 

using chemical speciation data to help characterize contributing emissions sources and the determination of 

nearby contributions through analyses that differentiate local and regional source contributions.

Factor 2: Emissions and emissions-related data. The emissions analysis examines identified sources of direct 

PM2.5, the major components of direct PM2.5 (primary organic carbon (POC)/organic mass (OM), elemental 

carbon (EC), crustal material (and/or individual trace metal compounds)), primary nitrate and primary sulfate, 

and precursor gaseous pollutants (e.g., sulfur dioxide (SO2), nitrogen oxides (NOx), total volatile organic 

compounds (VOC), and ammonia (NH3). Emissions data are generally derived from the most recent National 

Emissions Inventory (NEI) (i.e., 2011 NEI version 1), and are given in tons per year. In some cases, the EPA 

may also evaluate emissions information from states, tribes, or other relevant sources that may not be reflected 

in the NEI. One example of “other information” could include an inventory or assessment of local/regional area 

sources that individually does not meet the current threshold for reporting to the NEI but collectively 

contributes to area PM2.5 concentrations. Emissions data indicate the potential for a source to contribute to 

observed violations, making it useful in assessing boundaries of nonattainment areas.

Factor 3: Meteorology. Evaluating meteorological data helps to determine the effect on the fate and transport of 

emissions contributing to PM2.5 concentrations and to identify areas potentially contributing to the violations at 

monitoring sites. The Factor 3 analysis includes assessing potential source-receptor relationships in the area 

identified for evaluation using summaries of air trajectories, wind speed, wind direction, and other 

meteorological data, as available.

Factor 4: Geography/topography. The geography/topography analysis includes examining the physical features 

of the land that might define the airshed and, therefore, affect the formation and distribution of PM2.5 over an 

area. Mountains or other physical features may influence the fate and transport of emissions and PM2.5

concentrations. Additional analyses may consider topographical features that cause local stagnation episodes via 

inversions, such as valley-type features that effectively “trap” air pollution, leading to periods of elevated PM2.5

concentrations. 

Factor 5: Jurisdictional boundaries. The analysis of jurisdictional boundaries identifies the governmental 

planning and organizational structure of an area that may be relevant for designations purposes. These 

jurisdictional boundaries provide insight into how the governing air agencies conduct or might conduct air 

 

11 Suitable monitors include all FEM and/or ARMs except those specific continuous FEMs/ARMs used in the monitoring 

agency's network where the data are not of sufficient quality such that data are not to be compared to the NAAQS in 

accordance with 40 CFR part 58.10(b)(13) and approved by the EPA Regional Administrator per 40 CFR part 58.11(e).

12 As indicated in Appendix N to 40 CFR part 50, Interpretation of the National Ambient Air Quality Standards for PM2.5, 

section 3(a) indicates “Except as otherwise provided in this appendix, all valid FRM/FEM/ARM PM2.5 mass concentration 

data produced by suitable monitors that are required to be submitted to AQS, or otherwise available to EPA, meeting the 

requirements of part 58 of this chapter including appendices A, C, and E shall be used in the DV (design value)

calculations. Generally, EPA will only use such data if they have been certified by the reporting organization (as prescribed

by § 58.15 of this chapter); however, data not certified by the reporting organization can nevertheless be used, if the 

deadline for certification has passed and EPA judges the data to be complete and accurate.”
Page 5 of 30

quality planning and enforcement in a potential nonattainment area. Examples of jurisdictional boundaries 

include counties, air districts, areas of Indian country, CBSA or CSA, metropolitan planning organizations, and 

existing nonattainment areas.

3.1 Area Background and Overview for the Louisville/Jefferson County CBSA 

Figure 1 is a map of the EPA’s intended nonattainment boundary for the Louisville/Jefferson CBSA. The map 

shows the location and design values of ambient air quality monitoring locations, county and other jurisdictional 

boundaries.

For purposes of the 1997 annual PM2.5 NAAQS, portions of this area were designated nonattainment. The 

boundary for the nonattainment area for the 1997 annual PM2.5 NAAQS included the entire counties of Jefferson 

and Bullitt in Kentucky; and Clark, Floyd and a portion of Jefferson counties in Indiana. 

Figure 1. The EPA’s Intended Nonattainment Boundaries for the Louisville, KY-IN Area
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The EPA must designate as nonattainment areas that violate the NAAQS and nearby areas that contribute to the 

violation. Clark, IN shows a violation of the 2012 PM2.5 NAAQS, therefore this county is included in the 

nonattainment area. Data in the Jefferson County, Kentucky portion of this area is invalid. The EPA evaluated 

each county without a violating monitoring site located near the county with a violating monitoring site based 

on the five factors and other relevant information and determined that Floyd County, Indiana, and Jefferson 

County and the urbanized portion of Bullitt County in Kentucky contribute to the nearby violation. The 

following sections describe this five factor analysis process. While the factors are presented individually, they 

are not independent. The five factor analysis process carefully considers their interconnections and the 

dependence of each factor on one or more of the others.

Factor 1: Air Quality Data

All data collected during the year are important when determining contributions to an annual standard such as 

the 2012 annual PM2.5 NAAQS. Compliance with an annual NAAQS is dependent upon monitor readings 

throughout the year, including days with monitored ambient concentrations below the level of the NAAQS. For

the 2012 annual PM2.5 NAAQS, the annual mean is calculated as the mean of quarterly means. A high quarter 

can drive the mean for an entire year, which, in turn, can drive an elevated 3-year DV. Although all data are 

important, seasonal or episodic emissions can provide insight as to relative contributors to measured PM2.5

concentrations. For these reasons, for the Factor 1 air quality analysis, the EPA assessed and characterized air 

quality at, and in the proximity of, the violating monitoring site locations first, by evaluating trends and the 

spatial extent of measured concentrations at monitors in the area of analysis, and then, by identifying the 

conditions most associated with high average concentration levels of PM2.5 mass in the area of analysis. 

In most cases, the EPA assessed air quality data on a seasonal, or quarterly, basis.

13 The EPA also identified the 

spatial extent of these high PM2.5 concentrations. The mass and composition at the design value location 

represents contributions from various emission sources including local, area-wide (which may comprise nearby 

urban and rural areas) and regional sources. To determine the source mix (by mass) at the design value 

monitoring site, the EPA examined the chemical composition of the monitored PM2.5 concentrations by pairing 

each violating FRM/FEM/ARM monitoring site with a collocated or nearby Chemical Speciation Network 

(CSN) monitoring site or sites. Then, the EPA contrasted the approximated mass composition at the design 

value monitoring site with data collected at IMPROVE14 and other monitoring locations whose data are 

representative of regional background. This comparison of local/area-wide chemical composition data to 

 

13 Although compliance with the annual NAAQS depends on contributions from all days of the year, examining data on a 

quarterly or seasonal basis can inform the relationship between the temporal variability of emissions and meteorology and 

the resulting PM2.5 mass and composition. In some areas of the country where there may be noticeable month-to-month 

variations in average PM2.5, the quarterly averages may not adequately represent seasonal variability. In these areas, air 

quality data may be aggregated and presented by those months that best correspond to the local “seasons” in these areas. 

14 IMPROVE stands for Interagency Monitoring for Protected Visual Environments and is an aerosol monitoring network 

in mostly rural and remote areas.
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regional chemical composition data derives an “urban increment,”

15,16 which helps differentiate the influence of 

more distant emissions sources from the influence of closer emissions sources, thus representing the portion of 

the measured violation that is associated with nearby emission contributions.17,18,19

PM2.5 Design Values and Total Mass Measurements – The EPA examined ambient PM2.5 air quality monitoring 

data represented by the DVs at the violating monitoring site and at other monitors in the area of analysis. The 

EPA calculated DVs based on air quality data for the most recent 3 consecutive calendar years of qualityassured, certified air quality data from suitable FEM/FRM/ARM monitoring sites in the EPA’s AQS. For this 

designations analysis, the EPA used data for the 2011-2013 period (i.e., the 2013 design value), which are the 

most recent years with fully-certified air quality data. A monitor’s DV is the metric or statistic that indicates 

whether that monitor attains a specified air quality standard. The 2012 annual PM2.5 NAAQS is met at a 

monitoring site when the 3-year average annual mean concentration is 12.0 (μg/m3) or less (e.g., 12.1 μg/m3 or 

greater is a violation). A DV is only valid if minimum data completeness criteria are met or when other 

regulatory data processing provisions are satisfied (See 40 CFR part 50 Appendix N). Table 2 identifies the 

current design value(s) (i.e., the 2013 DV) and the most recent two design values based on all monitoring sites

in the area of analysis for the Louisville intended nonattainment area.20

 

15 The “urban increment” analysis assesses and characterizes the increase in seasonal and annual average PM2.5 mass and 

chemical constituents observed at violating monitoring site(s) relative to monitoring sites outside the area of analysis 

(which represent background concentrations). Developing the urban increment involves pairing a violating 

FRM/FEM/ARM monitor with a collocated monitor or nearby monitor with speciation data. The EPA made every effort to 

pair these data to represent the same temporal and spatial scales. However, in some cases, the paired violating and CSN 

“urban” monitoring locations were separated by some distance such that the included urban CSN site(s) reflect(s) a 

different mixture of emissions sources, which could lead to misinterpretations. To generally account for differences in 

PM2.5 mass between the violating site and the nearby CSN site(s), the EPA determined material balance of the PM2.5

composition at the violating site by assigning the extra measured PM2.5 mass to the carbon components of PM2.5. Where the 

general urban increment approach may be misleading, or in situations where non-carbonaceous emissions are believed to 

be responsible for a local PM2.5 concentration gradient, the EPA used alternative analyses to reflect the mix of urban and 

rural sources contributing to the measured concentrations at violating monitoring sites.

16 The urban monitors were paired with any rural sites within a 150 mile radius of an urban site to calculate spatial means 

of the quarterly averages of each species. If there were no rural sites within 150 miles, then the nearest rural site was used 

alone. That rural mean was then subtracted from the quarterly mean of the urban site to get the increment. Negative values 

were simply replaced with zeros.

17 In most, but not all, cases, the violating design value monitoring site is located in an urban area. Where the violating 

monitor is not located in an urban area, the “urban increment” represents the difference between local and other nearby 

emission sources in the vicinity of the violating monitoring location and more regional sources.

18 Hand, et. al. Spatial and Seasonal Patterns and Temporal Variability of Haze and its Constituents in the United 

States: Report V, June 2011. Chapter 7 – Urban Excess in PM2.5 Speciated Aerosol Concentrations, 

http://vista.cira.colostate.edu/improve/Publications/Reports/2011/PDF/Chapter7.pdf

19 US EPA, Office of Air Quality Planning and Standards, December 2004. (2004) Area Designations for 1997 Fine 

Particle (PM2.5) Standards, Technical Support Document for State and Tribal Air Quality Fine Particle (PM2.5) 

Designations, Chapter 3, Urban Excess Methodology. Available at 

www.epa.gov/pmdesignations/1997standards/documents/final/TSD/Ch3.pdf

20 In certain circumstances, one or more monitoring locations within a monitoring network may not meet the network 

technical requirements set forth in 40 CFR 58.11(e), which states, “State and local governments must assess data from 
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Table 2. Air Quality Data collected at Regulatory Monitors (all DV levels in μg/m3)

a,b

County, State Monitor Site ID State Rec NA? 09-11 DV 10-12 DV 11-13 DV

Bullitt, KY 210290006 No Monitor shut down 2011

Clark, IN 180190006 No 13.5 13.2 12.1

Clark, IN 180190008 No 11.4 11.0 10.0

Floyd, IN 180431004 No 12.3 11.8 10.7

Jefferson, KY 211110043 No Invalid data (awaiting EPA decision)

Jefferson, KY 211110044 No Invalid data (awaiting EPA decision)

Jefferson, KY 211110051 No Invalid data (awaiting EPA decision)

Jefferson, KY 211110067 No Invalid data (awaiting EPA decision)

a Where a county has more than one monitoring location, the county design value is indicated in red type.

b This design value does not include data from Class III FEM monitors that are not eligible for comparison to the NAAQS, 

as approved by the EPA pursuant to 40 CFR 58.11(e).

The Figure 1 map, shown previously, identifies the Louisville/Jefferson CBSA intended nonattainment area, the 

CBSA boundary and monitoring locations with 2011-2013 violating DVs. As indicated on the map, there is one

violating monitoring location in Jeffersonville in Clark County. This monitor has consistently had a higher DV 

in the region including the 1997 PM2.5 designation. There is a second monitor in Clark County to the northeast 

and one monitor to the west in Floyd County, both have attaining data. There are four monitors in Jefferson 

County, KY and all have invalid data for this subject time period. 

Seasonal variation can highlight those conditions most associated with high average concentration levels of 

PM2.5. Figure 2 shows quarterly mean PM2.5 concentrations for the most recent 3-year period for the highest DV 

monitoring sites and other, non-violating, monitoring sites in each county within the area of analysis. This 

graphical representation is particularly relevant when assessing air quality data for an annual standard, such as 

the 2012 annual PM2.5 NAAQS, because, as previously stated, the annual mean is calculated as the mean of 

quarterly means and a high quarter can drive the mean for an entire year, which, in turn, can drive an elevated 3-

year DV

 

Class III PM2.5 FEM and ARM monitors operated within their network using the performance criteria described in table C4 to subpart C of part 53 of this chapter, for cases where the data are identified as not of sufficient comparability to a 

collocated FRM, and the monitoring agency requests that the FEM or ARM data should not be used in comparison to the 

NAAQS. These assessments are required in the monitoring agency's annual monitoring network plan described in 

§58.10(b) for cases where the FEM or ARM is identified as not of sufficient comparability to a collocated FRM....”
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Figure 2. Louisville PM2.5 Quarterly Means for 2010-2012

As shown, Quarterly values across the period vary by 5 μg/m3at the Clark County site, with consistent annual 

peaks occurring in Q3. 

PM2.5 Composition Measurements - To assess potential emissions contributions for each violating monitoring 

location, the EPA determined the various chemical species comprising total PM2.5 to identify the chemical 

constituents over the analysis area, which can provide insight into the types of emission sources impacting the 

monitored concentration. To best describe the PM2.5 at the violating monitoring location, the EPA first adjusted 

the chemical speciation measurement data from a monitoring location at or near the violating FRM monitoring 

site using the SANDWICH approach to account for the amount of PM2.5 mass constituents retained in the FRM 

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

'10 Q1 '10 Q2 '10 Q3 '10 Q4 '11 Q1 '11 Q2 '11 Q3 '11 Q4 '12 Q1 '12 Q2 '12 Q3 '12 Q4

PM2.5 Concentrations

μg/m3

Louisville PM2.5 Quarterly Means 2010-2012

Clark Clark Floyd
Page 10 of 30

measurement.21,22,23,24 In particular, this approach accounts for losses in fine particle nitrate and increases in 

sulfate mass associated with particle bound water. Figure 3a illustrates the fraction of each PM2.5 chemical 

constituent at the Clark County (180190006) monitoring site based on annual averages for the years 2010-2012.

Figure 3a shows the PM2.5 chemical constituent annual average for DV monitor from Clark County monitor. 

Figure 3a. Louisville Annual Average PM2.5 Chemical Constituents (2010-2012) 

Figure 3b shows annual and quarterly chemical composition profiles and illustrates seasonal and episodic

contributors to PM2.5 mass. This “increment analysis,” combined with the other factor analyses, can provide 

 

21 SANDWICH stands for measured Sulfate, Adjusted Nitrate, Derived Water, Inferred Carbonaceous mass Hybrid 

Material Balance Approach.” The SANDWICH adjustment uses an FRM mass construction methodology that results in 

reduced nitrates (relative to the amount measured by routine speciation networks), higher mass associated with sulfates 

(reflecting water included in gravimetric FRM measurements) and a measure of organic carbonaceous mass derived from 

the difference between measured PM2.5 and its non-carbon components. This characterization of PM2.5 mass also reflects 

crustal material and other minor constituents. The resulting characterization provides a complete mass closure for the 

measured FRM PM2.5 mass, which can be different than the data provided directly by the speciation measurements from 

the CSN network.

22 Frank, N. H., SANDWICH Material Balance Approach for PM2.5 Data Analysis, National Air Monitoring Conference, 

Las Vegas, Nevada, November 6-9, 2006. http://www.epa.gov/ttn/amtic/files/2006conference/frank.pdf.

23 Frank, N. H., The Chemical Composition of PM2.5 to support PM Implementation, the EPA State /Local/Tribal Training 

Workshop: PM2.5 Final Rule Implementation and 2006 PM2.5 Designation Process, Chicago IL, June 20-21, 2007,

http://www.epa.gov/ttn/naaqs/pm/presents/pm2.5_chemical_composition.pdf.

24 Frank, N. H. Retained Nitrate, Hydrated Sulfates, and Carbonaceous Mass in Federal Reference Method Fine 

Particulate Matter for Six Eastern U.S. Cities. J. Air & Waste Manage. Assoc. 2006 56:500–511.

5.01

0.85

0.88

5.36

0.93

Annual Average PM2.5 Chemical 

Constituents 2010-2012 (μg/m3)

Organic Mass Elemental Carbon Nitrates Sulfates Crustal
Page 11 of 30

additional insight as to which sources or factors may contribute at a greater level. Simply stated, this analysis 

can help identify nearby sources of emissions that contribute to the violation at the violating monitoring site. 

Figure 3b. Louisville Annual and Quarterly Average PM2.5 Species (2010-2012)

a

a Adjusted to FRM Total PM2.5 indicates that the speciation profile and total mass depicted in this figure are the result of the 

urban increment calculation for the particular FRM monitor.

Figures 3a and 3b show that sulfate and OM are the predominant species overall. Crustal and elemental carbon

comprise a small percentage in all four quarters. Sulfate peaks in quarter three. Nitrate is a relatively small 

component in all quarters, but is slightly higher in Q1 & 4. It is likely that the large sulfate component is caused 

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

Annual Q1 Q2 Q3 Q4

μg/m3

Annual and Quarterly Average PM2.5 Species 

2010-2012 Adjusted to FRM Total PM2.5

Organic Mass Elemental Carbon Nitrates Sulfates Crustal

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Annual Q1 Q2 Q3 Q4

Organic Mass Elemental Carbon Nitrates Sulfates Crustal
Page 12 of 30

by SO2 emissions from large electric generating units in the area. High levels of organic mass are typically 

associated with mobile sources, wood or biomass burning and localized combustion sources.25 

The EPA assessed seasonal and annual average PM2.5 constituents at monitoring sites within the area relative to 

monitoring sites outside of the analysis area to account for the difference between regional background 

concentrations of PM2.5, and the concentrations of PM2.5 in the area of analysis, also known as the “urban 

increment.” This analysis differentiates between the influences of emissions from sources in nearby areas and in 

more distant areas on the violating monitor. Estimating the urban increment in the area helps to illuminate the 

amount and type of particles at the violating monitor that are most likely to be the result of sources of emissions 

in nearby areas, as opposed to impacts of more distant or regional sources of emissions. Figure 4a includes pie 

charts showing the annual and quarterly chemical mass constituents of the urban increment. The quarterly pie 

charts correspond to the high-concentration quarters identified in Figure 2. Evaluating these high concentration 

quarters can help identify composition of PM2.5 during these times. Note that in these charts, sulfates and 

nitrates have been adjusted to represent their mass in measured PM2.5.

Figure 4a. Louisville/Jefferson CBSA Urban Increment Analysis for 2010-2012.

 

25 The EPA Guidance Memorandum,“Initial Area Designations for the 2012 Revised Primary Annual Fire Particulate 

National Ambient Air Quality Standard,” dated April 16, 2013, Attachment 3.

47%

13%

5%

20%

15%

Annual Average Urban Increment 

2010-2012 (μg/m3)

Organic Mass

Elemental

Carbon

Nitrates

Sulfates

Crustal
Page 13 of 30

Figure 4b. Louisville/Jefferson CBSA Average Urban Increment Analysis for 2010-2012. 

2.34

0.53

0.35

0.33

0.38

Q-1 Average Urban 

Increment 2010-2012 

(μg/m3)

Organic Mass

Elemental Carbon

Nitrates

Sulfates

Crustal

1.02

0.40

0.00

0.55

0.42

Q-2 Average Urban 

Increment 2010-2012 

(μg/m3)

Organic Mass

Elemental Carbon

Nitrates

Sulfates

Crustal

0.74

0.24

1.20 0.00

0.42

Q-3 Average Urban 

Increment 2010-2012 

(μg/m3)

Organic Mass

Elemental Carbon

Nitrates

Sulfates

1.93

0.49

0.35

0.52

0.65

Q-4 Average Urban 

Increment 2010-2012 

(μg/m3)

Organic Mass

Elemental Carbon

Nitrates

Sulfates

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

Annual Q1 Q2 Q3 Q4

Average Urban Increment 2010-2012 (μg/m3)

Organic Mass Elemental Carbon Nitrates Sulfates Crustal
Page 14 of 30

Clark County has one monitoring site with a DV exceeding the NAAQS. The urban increment calculated for 

the Clark County violating monitor reveals a seasonal peak in ambient PM2.5 concentrations in quarters 1 and 

4. 

A comparison of the average urban increment to the total measured PM2.5 for the Louisville area indicates that 

the urban increment is less than one-third of the total. This indicates a significant contribution from regional 

sources. Looking at speciated components of the urban increment for the Louisville CBSA DV monitor, the 

organic mass component appears to have the largest urban contribution for quarters 1 and 4. Sulfate is second 

highest annual urban increment component and peaks during quarter 3, showing a potential contribution from 

local SO2 sources. Elemental carbon has a large increment in quarters 1, 2, and 4. During all quarters of the 

year, there is also a relatively high organic mass to elemental carbon ratio, which potentially indicates 

contribution from wood combustion or biomass burning sources. This analysis points to contribution from both 

regional and local PM2.5 sources.

Factor 2: Emissions and emissions-related data

In this designations process, for the area with a violating monitoring site, the EPA evaluated the emissions data 

from nearby areas using emissions related data for the relevant counties to assess each county’s potential 

contribution to PM2.5 concentrations at the violating monitoring site in the area under evaluation. Similar to the 

air quality analysis, these data were examined on a seasonal basis. The EPA examined emissions of identified 

sources or source categories of direct PM2.5, the major components of direct PM2.5 (organic mass, elemental 

carbon, crustal material (and/or individual trace metal compounds)), primary nitrate and primary sulfate, and 

precursor gaseous pollutants (i.e., SO2, NOx, total VOC, and NH3). The EPA also considered the distance of 

those sources of emissions from the violating monitoring site. While direct PM2.5 emissions and its major 

carbonaceous components are generally associated with sources near violating PM2.5 monitoring sites, the 

gaseous precursors tend to have a more regional influence (although the EPA is mindful of the potential local 

NOx and VOC emissions contributions to PM2.5 from mobile and stationary sources) and transport from 

neighboring areas can contribute to higher PM2.5 levels at the violating monitoring sites. 

Emissions Data

For this factor, the EPA reviewed data from the 2011 NEI version 1 (see 

http://www.epa.gov/ttn/chief/net/2011inventory.html). For each county in the area of analysis, the EPA

examined the magnitude of county-level emissions reported in the NEI. These county-level emissions represent 

the sum of emissions from the following general source categories: point sources, non-point (i.e., area) sources, 

nonroad mobile, on-road mobile, and fires. The EPA also looked at the geographic distribution of major point 

sources of the relevant pollutants.26 Significant emissions levels from sources in a nearby area indicate the 

potential for the area to contribute to monitored violations.

 

26 For purposes of this designations effort, “major” point sources are those whose sum of PM precursor emissions (PM2.5 + 

NOx + SO2 + VOC + NH3) are greater than 500 tons per year based on NEI 2011v1.
Page 15 of 30

To further analyze area emissions data, the EPA also developed a summary of direct PM2.5, components of 

direct PM2.5, and precursor pollutants, which is available at 

http://www.epa.gov/pmdesignations/2012standards/docs/nei2011v1pointnei2008v3county.xlsx.

When considered with the urban increment analysis in Factor 1, evaluating the components of direct PM2.5 and 

precursor gases can help identify specific sources or source types contributing to elevated concentrations at 

violating monitoring sites and thus assist in identifying appropriate area boundaries. In general, directly emitted 

POC and VOCs27 contribute to PM2.5 OM; directly emitted EC contributes to PM2.5 EC; NOx, NH3 and directly 

emitted nitrate contribute to PM2.5 nitrate mass; SO2, NH3 and directly emitted sulfate contribute to PM2.5 sulfate 

mass; and directly emitted crustal material and metal oxides contribute to PM2.5 crustal matter. 28,29 The EPA 

believes that the quantities of those nearby emissions as potential contributors to the PM2.5 violating monitors

are somewhat proportional to the PM2.5 chemical constituents in the estimated urban increment. Thus, directly 

emitted POC is more important per ton than SO2, partially because POC emissions are already PM2.5 whereas 

SO2 must convert to PM2.5 and not all of the emitted SO2 undergoes this conversion. 

Table 3a provides a county-level emissions summary (i.e., the sum of emissions from the following general 

source categories: point sources, non-point (i.e., area) sources, nonroad mobile, on-road mobile, and fires) of 

directly emitted PM2.5 and precursor species for the county with the violating monitoring site and nearby 

counties considered for inclusion in the Louisville/Jefferson CBSA area. Table 3b summarizes the directly 

emitted components of PM2.5 for the same counties in the area of analysis for the Louisville/Jefferson CBSA.

This information will be paired with the Urban Increment composition previously shown in Figures 4a and 4b.

Table 3a. County-Level Emissions of Directly Emitted PM2.5 and Precursors (tons/year)

County, State Total NH3 Total NOx Total Direct 

PM2.5

Total 

SO2

Total VOC Total

Jefferson, KY 915 39315 8163 39233 26406 114,032

Jefferson, IN 468 11841 973 74124 1940 89348

Nelson, KY 1037 1414 470 247 8268 11,435

Clark, IN 824 4158 1137 1577 3260 10,956

Bullitt, KY 137 3406 590 447 4965 9,544

Floyd, IN 127 3235 375 3027 1694 8,458

Trimble, KY 129 2579 174 3155 493 6,529

Harrison, IN 1654 1760 601 29 1682 5,726

Shelby, KY 629 2539 391 16 2054 5,629

 

27 As previously mentioned, nearby VOCs are presumed to be a less important contributor to PM2.5 OM than POC. 

28 See, Seinfeld J. H. and Pandis S. N. (2006) Atmospheric Chemistry and Physics: From Air Pollution to Climate Change, 

2nd edition, J. Wiley, New York. See also, Seinfeld J. H. and Pandis S. N. (1998) Atmospheric Chemistry and Physics: 

From Air Pollution to Climate Change, 1st edition, J. Wiley, New York.

29 USEPA Report (2004), The Particle Pollution Report: Current Understanding of Air Quality and Emissions through 

2003, found at: http://www.epa.gov/airtrends/aqtrnd04/pm.html.
Page 16 of 30

County, State Total NH3 Total NOx Total Direct 

PM2.5

Total 

SO2

Total VOC Total

Washington, 

IN 1261 874 481 23 1309 3,949

Oldham, KY 179 1797 285 13 1271 3,544

Meade, KY 484 1013 291 98 1371 3,257

Henry, KY 407 1270 193 11 802 2,683

Spencer, KY 133 396 167 7 512 1,215

Table 3b. County-Level Emissions for Components of Directly Emitted PM2.5 (tons/year) 30

County, State POM EC PSO4 PNO3 Crustal Residual Total Direct

Jefferson, KY 2330 715 443 13 2091 2570 8,163

Clark, IN 406 107 51 12 291 272 1,137

Jefferson, IN 398 77 32 4 218 245 973

Harrison, IN 306 62 7 1 106 118 601

Bullitt, KY 274 107 7 1 78 122 590

Washington, IN 258 47 3 2 86 85 481

Nelson, KY 203 63 7 1 83 114 470

Shelby, KY 146 69 7 1 69 99 391

Floyd, IN 170 65 6 1 55 78 375

Meade, KY 125 36 3 1 57 69 291

Oldham, KY 134 61 3 1 38 48 285

Henry, KY 79 35 2 0 39 38 193

Trimble, KY 48 35 8 1 32 50 174

Spencer, KY 87 20 1 1 27 32 167

Table 3b breaks down the direct PM2.5 emissions value from Table 3a into its components. The data were

compared with the previously presented Urban Increment composition.

Using the previously described relationship between directly emitted and precursor gases and the measured 

mass to evaluate data presented in Tables 3a and 3b, the EPA identified the following components warranting 

additional review: NOx, POM and SO2. The EPA then looked at the contribution of these constituents of 

interest from each of the counties included in the area of analysis as shown in Tables 4 a-c.

Table 4a. County-Level [NOx] Emissions (tons/year)

Emissions in average tons/yr

County, State NOX Pct. Cumulative %

Jefferson, KY 39315 52% 52%

Jefferson, IN 11841 16% 68%

Clark, IN 4158 6% 73%

 

30 Data are based on the 2011 and 2018 Emissions Modeling Platform Data Files and Summaries

(ftp://ftp.epa.gov/EmisInventory/2011v6/v1platform) available at: http://www.epa.gov/ttn/chief/emch/index.html#2011

(accessed 02/26/14).
Page 17 of 30

Emissions in average tons/yr

County, State NOX Pct. Cumulative %

Bullitt, KY 3406 5% 78%

Floyd, IN 3235 4% 82%

Trimble, KY 2579 3% 85%

Shelby, KY 2539 3% 89%

Oldham KY 1797 2% 91%

Harrison, IN 1760 2% 93%

Nelson, KY 1414 2% 95%

Henry, KY 1270 2% 97%

Meade, KY 1013 1% 98%

Washington, IN 874 1% 99%

Spencer, KY 396 1% 100%

Table 4b. County-Level [POM] Emissions 

Emissions in average tons/yr

County, State POM Pct. Cumulative %

Jefferson, KY 2330 47% 47%

Clark, IN 406 8% 55%

Jefferson, IN 398 8% 63%

Harrison, IN 306 6% 69%

Bullitt, KY 274 6% 75%

Washington, IN 258 5% 80%

Nelson, KY 203 4% 84%

Floyd, IN 170 3% 88%

Shelby, KY 146 3% 90%

Oldham, KY 134 3% 93%

Meade, KY 125 3% 96%

Spencer, KY 87 2% 97%

Henry, KY 79 2% 99%

Trimble, KY 48 1% 100%

Table 4c. County-Level [SO2] Emissions 

Emissions in average tons/yr

County, State SO2 Pct. Cumulative %

Jefferson, IN 74124 61% 61%

Jefferson, KY 39233 32% 93%

Trimble, KY 3155 3% 95%

Floyd, IN 3027 2% 98%

Clark, IN 1577 1% 99%
Page 18 of 30

Emissions in average tons/yr

County, State SO2 Pct. Cumulative %

Bullitt, KY 447 <1% 100%

Nelson, KY 247 <1% 100%

Meade, KY 98 <1% 100%

Harrison, IN 29 <1% 100%

Washington, IN 23 <1% 100%

Shelby, KY 16 <1% 100%

Oldham, KY 13 <1% 100%

Henry, KY 11 <1% 100%

Spencer, KY 7 <1% 100%

In addition to reviewing county-wide emissions of PM2.5 and PM2.5 precursors in the area of analysis, the EPA 

also reviewed emissions from major point sources located in the area of analysis. The magnitude and location of 

these sources can help inform nonattainment boundaries. Table 5 provides facility-level emissions of direct 

PM2.5, components of direct PM2.5, and precursor pollutants (given in tons per year) from major point sources 

located in the area of analysis for the Louisville/Jefferson CBSA area. Table 5 also shows the distance from the 

facility to the DV monitor for the respective county.

Table 5. NEI 2011 v1 Point Source Emissions (tons/year) 

Distance NEI 2011 v1 Emissions - Tons/Year

County, State Facility Name (Facility ID) monitor 

(miles)

NH3 NOx PM2.5 SO2 VOC Total

Bullitt, KY Four Roses Distillery Inc (2102900004) 26 - - - - 1,216 1,216

Bullitt, KY Jim Beam Brands Co - Clermont Plant 

(2102900005) 25 - 86 6 187 1,487 1,766

Clark, IN ESSROC CEMENT CORP.( 00008) 9 0 1,153 217 1,545 60 2,974

Floyd, IN DUKE ENERGY INDIANA – GALLAGHER 

(000040 5 1 1,344 12 3,010 11 4,378

Jefferson, IN IKEC - CLIFTY CREEK STATION (00001) 36 2 10,938 281 74,086 85 85,392

Jefferson, KY Louisville Gas & Electric Co., Cane Run Station 

(0126) 10 0 5,596 420 7,824 48 13,888

Jefferson, KY Kosmos Cement Company (0060) 19 22 1,097 114 187 51 1,472

Jefferson, KY Ford Motor Company, Kentucky Truck Plant (0073) 11 2 69 17 0 698 787

Jefferson, KY Louisville Gas & Electric Co., Mill Creek Station 

(0127) 18 0 8,495 2,780 29,945 130 41,350

Jefferson, KY American Synthetic Rubber Company (0011) 7 1 549 30 137 256 973

Jefferson, KY Brown-Forman Distilleries, Early Times (0244) 6 0 80 13 258 1,416 1,767

Jefferson, KY Heaven Hill Distilleries (0243) 3 0 15 2 0 1,400 1,417

Jefferson, KY Reynolds Packaging Group, Foil Plant (0186) 4 0 14 3 0 1,306 1,323

Jefferson, KY Diageo Americas Supply, Inc. (0167) 6 0 1 0 0 1,616 1,617

Jefferson, KY Louisville Medical Center Steam Plant (148) 2 0 161 31 476 1 669

Jefferson, KY Louisville Intl-Standif 7 - 1,421 26 136 148 1,732

Nelson, KY Heaven Hill Distilleries (2117900005) 37 - 1 0 0 1,853 1,855
Page 19 of 30

Distance NEI 2011 v1 Emissions - Tons/Year

County, State Facility Name (Facility ID) monitor 

(miles)

NH3 NOx PM2.5 SO2 VOC Total

Nelson, KY Jim Beam Brands Co - Boston Nelson Co

(2117900014) 33 - 72 31 181 2,429 2,712

Nelson, KY Barton Distillery (2117900020) 36 - 17 2 45 1,403 1,467

Trimble, KY Louisville Gas & Electric Co - Trimble Co 

Generating Station (2122300002 28 26 2,088 55 3,112 132 5,413

The IKEC-Clifty Creek Station facility located in Jefferson County, Indiana, stands out in Table 5 as having a 

large level of SO2 emissions reported in the 2011 NEI (74,086 tpy). Recently, the Clifty Creek facility has 

installed both flue gas desulfurization systems, as well as selective catalytic reduction systems on multiple units 

in order to satisfy federal rules controlling SO2 for transport as well as rules for controlling mercury and air 

toxics. SO2 emissions at the facility have decreased from 2011 levels of 36,391 total tpy for units 1, 2, 3, and 

37,694 total tpy for units 4, 5, 6 to levels in 2014 of 3,745 and 3,351 total tpy, respectively. The lower levels of 

emissions in combination with the large distance to the violating monitor and a low frequency of winds blowing 

from the facility toward the monitor, led to the conclusion that the facility is not contributing to the monitor 

violation.

Figure 5 shows the major point source emissions (from the 2011 NEI in tons per year) in the area of analysis for 

the Louisville/Jefferson County CBSA and the relative distances of these sources from the violating monitoring 

location, as depicted by red dot in the center of the map. The actual distance from the point sources to the DV 

monitoring location is presented in Table 5). The distance from the violating monitoring location is particularly

important for directly emitted PM2.5. The influence of directly emitted PM2.5 on ambient PM2.5 diminishes more 

than that of gaseous precursors as a function of distance.31

As indicated in Figure 5, there are 20 major point sources located within 37 miles of the violating monitor. 

Eleven of these point sources are located in Jefferson County, KY. 

 

31 Baker, K. R. and K. M. Foley. A nonlinear regression model estimating single source concentrations of primary and 

secondarily formed PM2.5. Atmospheric Environment. 45 (2011) 3758-3767.
Page 20 of 30

Figure 5. Major Point Source Emissions in the Area of Analysis for the Louisville/Jefferson CBSA Area.

In summary, the EPA’s analysis of relevant county-level emissions and the geographic locations of the relevant 

pollutants showed both Jefferson County, Kentucky, and Clark and Floyd Counties in Indiana had the highest 

overall emissions. SO2 are the predominant pollutant emissions in the area. Three of the four largest SO2 point 

source emissions are within 18 miles of the violating monitor. With the exception of Nelson County, 

KentukyKentucky, county emissions levels for the rest of the counties in the CBSA are lower the further away 

it is from the violating monitor. Nelson County, Kentucky’s emissions consist primarily of VOCs, mostly from 

three point sources. The total VOC emissions from Nelson County are less than one-third of the VOC emissions

from Jefferson County and are less than 15 percent of the total VOC emissions in the CBSA. The large distance 

from Nelson County to the violating monitor and the low frequency of winds blowing from the southeast east, 

led to the EPA’s conclusion that Nelson County is not contributing to the violating Clark County, Indiana, 

monitor. 
Page 21 of 30

Population density and degree of urbanization

In this part of the factor analysis, the EPA evaluated the population and vehicle use characteristics and trends of 

the area as indicators of the probable location and magnitude of non-point source emissions. Rapid population 

growth in a county on the urban perimeter signifies increasing integration with the core urban area, and 

indicates that it may be appropriate to include the county associated with area source and mobile source 

emissions as part of the nonattainment area. Table 6 shows the 2000 and 2010 population, population growth 

since 2000, and population density for each county in the area.

Table 6. Population Growth and Population Density.

County, State

Population 

2000

Population 

2010

%

Change 

from 

2000

Land 

Area (Sq. 

Miles)

Population 

Density (per 

Sq. Mile) %

Cumulative

%

Jefferson, KY 693,604 742,324 7.0% 385 1,928 58 58

Clark, IN 96,472 110,555 14.6% 375 295 9 66

Floyd, IN 70,823 74,657 5.4% 148 504 6 72

Bullitt, KY 61,236 74,490 21.6% 299 249 6 78

Oldham, KY 46,178 60,420 30.8% 189 319 5 83

Nelson, KY 37,477 43,594 16.3% 423 103 3 86

Shelby, KY 33,337 42,287 26.8% 384 110 3 89

Harrison, IN 34,325 39,357 14.7% 485 81 3 92

Washington, IN 27,223 28,265 3.8% 514 55 2 95

Meade, KY 26,349 28,695 8.9% 309 93 2 97

Spencer, KY 11,766 17,114 45.5% 186 92 1 98

Henry, KY 15,060 15,398 2.2% 289 53 1 99

Trimble, KY 8,125 8,787 8.1% 149 59 1 100

Total 1,161,975 1,285,943

Source: U.S. Census Bureau population estimates for 2000 and 2010 

The most densely populated counties are in and adjacent to the county with the violating monitor. Jefferson

County, Kentucky has the highest population density, about four times larger than Floyd County, which has the 

second highest. The area around the violating monitor is highly urbanized. Bullitt County, Kentucky is the fifth 

most densely populated with an urbanized area in the north adjacent to Louisville International Airport. Bullitt’s 

population grew 21 percent to 74,490, about 6 percent of the CBSA population. 
Page 22 of 30

Figure 6. 2010 County-Level Population in the Area of Analysis for the Louisville/Jefferson CBSA Area.

Traffic and Vehicle Miles Travelled (VMT)

High VMT and/or a high number of commuters associated with a county is generally an indicator that the 

county is an integral part of an urban area. Mobile source emissions of NOx, VOC, and direct PM may 

contribute to ambient particulate matter that contributes to monitored violations of the NAAQS in the area. In 

combination with the population/population density data and the location of main transportation arteries, an 

assessment of VMT helps identify the probable location of nonpoint source emissions that contribute to 

violations in the area. Comparatively high VMT in a county outside of the CBSA or CSA signifies integration 

with the core urban area contained within the CSA or CBSA, and indicates that a county with the high VMT 

may be appropriate to include in the nonattainment area because emissions from mobile sources in that county 

contribute to violations in the area. Table 7 shows 2011 VMT while Figure 7 overlays 2011 county-level VMT 

with a map of the transportation arteries. This data is from the Federal Highway Administration. 
Page 23 of 30

Table 7. 2011 VMT for the Louisville/Jefferson CBSA Area.

County, State Total 2011 VMT Percent Cumulative %

Jefferson, KY 7,222,527,493 54% 54%

Clark, IN 1,174,901,566 9% 63%

Bullitt, KY 952,778,343 7% 70%

Floyd, IN 672,638,182 5% 75%

Shelby, KY 648,551,690 5% 80%

Harrison, IN 589,004,275 4% 84%

Nelson, KY 492,911,504 4% 88%

Oldham, KY 467,765,544 4% 92%

Washington, IN 305,724,135 2% 94%

Henry, KY 300,376,674 2% 96%

Meade, KY 287,931,054 2% 98%

Spencer, KY 153,288,071 1% 99%

Trimble, KY 81,444,339 1% 100%

Total 13,349,842,870

http://www.census.gov/hhes/commuting/data/commuting.html

Figure 7. Overlay of 2011 County-level VMT with Transportation Arteries.
Page 24 of 30

Jefferson County and Bullitt County in Kentucky, and Clark County in Indiana had the largest VMT. More than 

half of all the VMT in the CBSA is in Jefferson County, KY. It is reasonable to infer that a substantial amount 

of the traffic is due to inter-county commuters, mainly from Bullitt, Clark and Floyd Counties. Additional 

analysis for Jefferson County, KY shows that 88 percent of all commuting is from intra-county and less than 7

percent of all commuting traffic comes from Bullitt County. The northern portion of Bullitt County is part of a 

contiguous, urbanized area and while only 7 percent of the commuters are heading to Jefferson County, a large 

portion can be attributed to the population centers and VMT from that portion of the county. 

Clark and Floyd Counties in Indiana, and Jefferson County in Kentucky consistently rank highest in direct 

PM2.5/key precursor emissions attributable in large part to VMT and population. Jefferson County, KY,

contributed more than 82 percent of SO2 and 83 percent total PM2.5 from stationary sources in the CBSA. 

Bullitt County is mid-ranked in emissions and mid-ranked for population and VMT. Most of the urbanized area 

of Bullitt County is adjacent to Jefferson, KY. Oldham, Nelson, Shelby, Harrison, Washington, Meade, 

Spencer, Henry and Trimble Counties have relatively low emissions and relatively low VMT/population counts, 

and lack large singular point source contributors. 

Factor 3: Meteorology

The EPA evaluated available meteorological data to determine how meteorological conditions, including, but 

not limited to, weather, transport patterns, and stagnation conditions, could affect the fate and transport of 

directly emitted particulate matter and precursor emissions from sources in the area of analysis. The EPA used 

two primary tools for this assessment: wind roses and kernel density estimation (KDE). When considered in 

combination with area PM2.5 composition and county-level and facility emissions source location information, 

wind roses and KDE can help to identify nearby areas contributing to violations at violating monitoring sites. 

Wind roses are graphic illustrations of the frequency of wind direction and wind speed. Wind direction can 

indicate the direction from which contributing emissions are transported; wind speed can indicate the force of 

the wind and thus the distance from which those emissions are transported. The EPA constructed wind roses 

from hourly observations of wind direction and wind speed using 2009-2012 data from National Weather 

Service locations archived at the National Climate Data Center.32 When developing these wind roses, the EPA 

also used wind observations collected at meteorological sampling stations collocated at air quality monitoring 

sites, where these data were available. Figure 8 shows wind roses that the EPA generated from data relevant in 

the Louisville/Jefferson CBSA area.

 

32 ftp.ncdc.noaa.gov/pub/data/noaa or 

http://gis.ncdc.noaa.gov/map/viewer/#app=cdo&cfg=cdo&theme=hourly&layers=1&node=gis Quality assurance of the 

National Weather Service data is described here: http://www1.ncdc.noaa.gov/pub/data/inventories/ish-qc.pdf
Page 25 of 30

Figure 8. Wind Roses in the Area of Analysis for Louisville/Jefferson CBSA Area.

As shown in Figure 8, there is a pattern across the CBSA of winds blowing predominantly from the south, west

and southwest, and a smaller frequency from the north, mostly at low to mid-level speeds of 2 to 6 meters per 

second.

In addition to wind roses, the EPA also generated KDE plots to represent HYSPLIT (HYbrid Single-Particle 

Lagrangian Integrated Trajectory) backward trajectory frequency at violating monitoring sites.

33,34 These KDEs 

are graphical statistical estimations to determine the density of trajectory endpoints at a particular location 

represented by a grid cell. The EPA used KDEs to characterize and analyze the collection of individual 

HYSPLIT backward trajectories.

35 Higher density values, indicated by darker blue colors, indicate a greater 

 

33 In some past initial area designations efforts, the EPA has used HYSPLIT backward trajectories to assist in determining 

nonattainment area boundaries. A HYSPLIT backward trajectory is usually depicted on a standard map as a single line, 

representing the centerline of an air parcel’s motion, extending in two dimensional (x,y) space from a starting point and 

regressing backward in time to a point of origin. Backward trajectories may be an appropriate tool to assist in determining 

an air parcel’s point of origin on a day in which a short-term standard, such as an 8-hour standard or a 24-hour standard, 

was exceeded. However, for an annual standard, such as the 2012 annual PM2.5 NAAQS, every trajectory on every day is 

important. Plotting a mass of individual daily (e.g., 365 individual back trajectories), or more frequent, HYSPLIT 

trajectories may not be helpful as this process is likely to result in depicting air parcels originating in all directions from the 

violating monitoring site.

34 HYSPLIT - Hybrid Single Particle Lagrangian Integrated Trajectory Model, http://www.arl.noaa.gov/HYSPLIT_info.php

35 The KDEs graphically represent the aggregate of HYSPLIT backward trajectories for the years 2010-2012, run every 

third day (beginning on the first day of monitoring), four times each day, and ending at four endpoint heights. 
Page 26 of 30

frequency of observed trajectory endpoints within a particular grid cell. Figure 9 shows HYSPLIT KDE plots

for the Louisville area summarized by calendar quarter for the 2010-2012 period. The HYSPLIT KDEs are

weighted in the south to westerly direction, indicating a greater frequency of trajectories passing over grid cells 

to the south and west.

Figure 9. HYSPLIT Kernel Density Estimation Plots for the Louisville/Jefferson CBSA Area.
Page 27 of 30
Page 28 of 30

In summary, for the violating monitor, the HYPSPLIT KDE plots and wind roses suggest greatest potential 

contribution of emissions from Jefferson and Bullitt Counties in Kentucky, and Clark, Floyd and Harrison 

Counties in Indiana. Potential emission contribution from other counties is low, including Jefferson Co. IN,

whose large point source is responsible for almost all of the listed precursor emissions for that county and it has 

recently reduced those emissions by over 90 percent.

Factor 4: Geography/topography

To evaluate the geography/topography factor, the EPA assessed physical features of the area of analysis that 

might define the airshed and thus affect the formation and distribution of PM2.5 concentrations over the area. 

The major topographic feature in the area is the Ohio River which forms the boundary between the states of 

Indiana and Kentucky. The river does not form a significant valley in the area with elevation changes in the 50-

100 meter range and does not significantly limit air pollution transport within the air shed. Therefore, this factor 

did not play a significant role in this evaluation.

Factor 5: Jurisdictional boundaries

In defining the boundaries of the intended Louisville nonattainment area, the EPA considered existing 

jurisdictional boundaries, which can provide easily identifiable and recognized boundaries for purposes of 

implementing the NAAQS. Existing jurisdictional boundaries often signify the state, local governmental 

organization with the necessary legal authority for carrying out air quality planning and enforcement functions 

for the intended area. Examples of such jurisdictional boundaries include existing/prior nonattainment area 
Page 29 of 30

boundaries for particulate matter, county lines, air district boundaries, township boundaries, areas covered by a 

metropolitan planning organization, state lines, and Reservation boundaries, if applicable. Where existing 

jurisdictional boundaries were not adequate or appropriate to describe the nonattainment area, the EPA 

considered other clearly defined and permanent landmarks or geographic coordinates for purposes of 

identifying the boundaries of the intended designated areas.

The Louisville area has previously established nonattainment boundaries associated with the 1997 annual PM2.5

NAAQS. The 1997 PM2.5 nonattainment area boundary consist of Jefferson and Bullitt Counties in Kentucky, 

and Clark, Floyd and a portion of Jefferson County in Indiana. The partial county in Jefferson, Indiana utilized 

Madison Township as the nonattainment boundary. Neither Kentucky nor Indiana have recommended 

nonattainment boundaries for the 2012 annual PM2.5 NAAQS. 

Conclusion for Louisville/Jefferson CBSA Area

Speciation and urban increment data show high organic carbon and sulfate content. Organic carbon and sulfate

components are the most important portions of the total PM2.5 mass throughout the year. Organic carbon may 

indicate biogenic emissions sources or biomass combustion sources. The predominant source of SO2 emissions

is the large point sources in the area. 

Indiana

Based on the assessment of factors described above, both individually and in combination, the EPA has 

preliminarily concluded that the following counties of Indiana should be included as part of the Louisville 

nonattainment area because they are either violating the 2012 annual PM2.5 NAAQS or contributing to a 

violation in a nearby area: Clark and Floyd Counties. These are the same counties that are included in the

Louisville nonattainment area for the 1997 annual PM2.5 NAAQS, with the exception that Jefferson County 

(partial) has been removed for the reasons discussed below.

Clark County has one air quality monitoring site that indicates violation of the 2012 annual PM2.5 NAAQS 

based on the 2013 DV; therefore this county is included in the nonattainment area. Clark County also has the 

second highest level of direct PM2.5 emissions in the CBSA with 1,137 tpy.

Floyd County is a nearby county that does not have a violating monitoring site, but the EPA has concluded that 

the County contributes to the particulate matter concentrations in violation of the 2012 annual PM2.5 NAAQS 

through emissions from point sources and non-point sources (e.g., area sources) and from mobile source 

emissions. Floyd County has the fourth highest level of SO2 emissions in the CBSA with 3,027 tpy. The 

prevailing winds blow in the direction from Floyd County toward the violating monitor, and there is a source of 

SO2 emissions (3,010 tpy), Duke Energy Indiana – Gallagher, five miles north of the monitor.

A small portion of Jefferson County, Indiana, was included in the nonattainment area for the 1997 annual PM2.5

NAAQS in order to capture the emissions from the IKEC-Clifty Creek Station facility. Emissions controls have 

been installed to satisfy federal rules requiring control of SO2 for transport as well as rules for controlling 

mercury and other air toxics. These controls have resulted in SO2 emissions reductions of over 90 percent since 

2011. Additionally, the wind rose and KDE plots presented in the meteorology factor discussion indicate that 

the predominant wind directions in the area do not support contribution from the Clifty Creek facility. 
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Therefore, the EPA is not recommending that the portion of Jefferson County that was previously included in 

the nonattainment area be included for the 2012 annual PM2.5 NAAQS. 

Kentucky

Based on the assessment of factors described above, both individually and in combination, the EPA has 

preliminarily concluded that the following counties should be included as part of the Louisville nonattainment 

area because they are contributing to a violation in a nearby area: Jefferson County, and the urbanized portion 

of Bullitt County. 

Jefferson County is a nearby county that does not have valid data from its monitoring sites. The EPA has 

concluded that this area contributes to the particulate matter concentrations in violation of the 2012 annual 

PM2.5 NAAQS through emissions from point sources and non-point sources (e.g., area sources), and from 

mobile source emissions. Jefferson County has among the highest emissions of directly emitted PM2.5 and PM2.5

precursors in the area. Jefferson County ranked relatively high for total emissions levels including high direct 

PM2.5, NOx and SO2, number of point sources, high population and VMT and high urbanization throughout the 

county. Additionally, the predominant winds blowing from the south support contribution from the Jefferson 

County emissions to the violating monitor to the north in Clark County, Indiana.

Bullitt County is a nearby county that does not have a PM2.5 air quality monitor. The EPA has concluded that 

emissions from the urbanized portion of the county contribute to the particulate matter concentrations in 

violation of the 2012 annual PM2.5 NAAQS. In review of the emissions from Bullitt County in Kentucky, the 

EPA determined that these emissions were primarily population-based emissions such as mobile and nonpoint 

sources. Thus, the EPA determined it was most appropriate to capture the urbanized portion of Bullitt County 

for inclusion in this area. 36 The wind roses and KDE plots presented in the meteorology factor discussion 

indicate that the predominant wind directions in the area support inclusion of the urbanized portion of Bullitt 

County. The EPA is using census tracts to define the nonattainment boundary for Bullitt County. The 

following census tracts are being included within the nonattainment area: 201, 202, 203, 204, 205, 206, 207, 

208 and 211. Census tract 211 also includes the two point sources identified in Table 5 (Four Roses Distillery 

Inc. and Jim Beam Brands Co.). 

In the event Indiana elects to early certify the 2012-2014 air quality data and the violating Clark County monitor 

does not violate the 2012 annual NAAQS, the EPA intends to designate the Louisville Area (with the same 

boundary as the intended nonattainment boundary identified in this TSD) as unclassifiable. Invalid data in 

Jefferson, KY precludes the EPA from issuing an unclassifiable/attainment designation for the Louisville Area. 

 

36 An Urbanized Area (UZA), as defined by the Census Bureau, consists of a central core and adjacent densely settled 

territory that together contain at least 50,000 people, generally with an overall population density of at least 1,000 people 

per square mile. The EPA evaluated the 2000 Census UZA data for Bullitt County in order to help define partial county 

boundary. The EPA overlaid the UZA areas with census tracts to determine the high population census tracts in Bullitt 

County, Kentucky.