Appendix N 

Conceptual Description 
Kentucky Conceptual Description April 15, 2008 1

PM2.5 Conceptual Description 

Kentucky PM2.5 Non-Attainment Areas 

First Draft April 15, 2008 

1.0 Objective 

This conceptual description provides a summary of the causes of PM2.5 non-attainment 

for counties in KY designated by EPA as not attaining the annual PM2.5 standard. The 

conceptual description includes summaries of the following analyses: 

• Non-attainment areas counties in KY and trends in overall PM2.5 mass for 

available monitoring record 1999-2006. 

• PM2.5 components that contribute to fine particle loadings in the PM2.5 nonattainment areas. 

• Meteorological conditions under which PM2.5 mass is elevated 

• Emissions contributions and emissions sensitivity analyses using the CMAQ 

regional air quality model to project changes in PM2.5 mass loadings in response 

to changes in 2009 emissions from specific source and pollutant categories 

The conceptual description concludes with a recommendation for major pollutants and 

source categories to consider in demonstrating attainment of the PM2.5 standard. 

2.0 PM2.5 Monitoring Data for Kentucky Non-Attainment Areas 

There are three PM2.5 non-attainment areas in Kentucky. All three areas are multi-state 

areas with counties and partial counties in more than one state as listed below: 

Louisville, KY-IN: KY - Bullitt and Jefferson Counties; IN - Clark, Floyd, and 

Jefferson Counties

Cincinnati-Hamilton, KY-IN-OH: OH- Butler, Clermont, Hamilton, and Warren 

Counties; IN - Dearborn County; KY - Boone, Campbell, and Kenton Counties 

Huntington-Ashland, KY-OH-WV: WV - Cabell and Wayne Counties, and the 

Graham Tax District in Mason County; Ky - Boyd County and the area in Lawrence 

County described by the US Census 2000 block group identifier 21-27-9901-6; OH - 

Lawrence and Scioto Counties, Monroe and Sprigg Townships in Adams County, and 

Addison and Cheshire Townships in Gallia County 

 

These nonattainment areas are illustrated in Figure 2.0-1. 
Kentucky Conceptual Description April 15, 2008 2

Figure 2.0-1. Counties in the Louisville, KY-IN, Cincinnati-Hamilton, KY-IN-OH, and 

Huntingon-Ashland, KY-OH-WV PM2.5 nonattainment areas. 

 

2.1 PM2.5 Federal Reference Method (FRM) Monitors 

EPA’s Federal Reference Method (FRM) PM2.5 monitors collect filter-based 24-hr 

samples every third or sixth day; total PM2.5 mass is reported. The FRM PM2.5 values 

are the basis for the designation of PM2.5 non-attainment areas listed above. Consistent 

with EPA modeling guidance1

, design values are calculated based on quarterly averages 

for the period 2000-2004. Annual average PM2.5 trends over the period 1999-2006 are 

illustrated for the Louisville, KY-IN non-attainment area in Figure 2.1-1, for the 

Cincinnati-Hamilton, KY-IN-OH area in Figure 2.1-2 and the for Huntington-Ashland, 

KY-OH-WV non-attainment area in Figure 2.1-3. Annual average PM2.5 values 

generally declined over the period 1999-2004, increased in 2005 and declined again in 

2006. In 2006, the highest annual average PM2.5 in the Louisville, KY-IN nonattainment area was 15.11 μg/m3 at the FRM monitor in Wyandotte Park, Jefferson 

County, KY (21-111-0044). In the Cincinnati-Hamilton, KY-IN-OH nonattainment area 

the highest 2006 annual average PM2.5 value was 15.80 μg/m3 at the Hamilton County, 

OH monitor at St. Bernard (39-061-8001). In the Huntington-Ashland, KY-IN-OH 

 

1

 Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals 

for Ozone, PM2.5, and Regional Haze. EPA–454/B-07-002. April 2007. 
Kentucky Conceptual Description April 15, 2008 3

nonattainment area the highest 2006 annual average PM2.5 value was 15.02 μg/m3 at the 

Cabell County, WV monitor (54-011-0006). 

Annual Average PM2.5 - Louisville, KY-IN 

0

2

4

6

8

10

12

14

16

18

20

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 

μg/m3

21-029-0006

21-111-0043

21-111-0044

21-111-0048

21-111-0051

18-019-0005

18-019-0006

18-043-1004

Figure 2.1-1. Annual Average PM2.5 mass for Federal Reference Method (FRM) 

monitors in Louisville, KY-IN non-attainment area for 1999-2006. 

Annual Average PM2.5 Cincinnati, KY-IN-OH

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 

μg/m3

21-037-0003

21-117-0007

39-061-0014

39-061-0040

39-061-0042

39-061-7001

39-061-8001

Figure 2.1-2. Annual Average PM2.5 mass for Federal Reference Method (FRM) 

monitors in the Cincinnati-Hamilton, KY-IN-OH non-attainment area for 1999-2006.
Kentucky Conceptual Description April 15, 2008 4

Annual Averge PM2.5 Huntington-Ashland, KY-OH-WV

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 

μg/m3

21-019-0017

39-087-0010

39-145-0013

54-011-0006

Figure 2.1-3. Annual Average PM2.5 mass for Federal Reference Method (FRM) 

monitors in the Huntington-Ashland, KY-OH-WV non-attainment area for 1999-2006.

Quarterly and annual average PM2.5 concentrations for the FRM monitors in the 

Louisville, KY-IN nonattainment area are illustrated in Figure 2.1-4, for the HuntingtonAshland, KY-OH-WV nonattainment area in Figure 2.1.5 and for the CincinnatiHamilton, KY-IN-OH nonattainment area in Figure 2.1.6. Quarterly trends are similar 

across the FRM monitors in the three nonattainment areas. For all these sites, the third 

quarter has the highest PM2.5 averages and the fourth quarter generally has the lowest 

averages. In the Cincinnati, OH nonattainment area, the Hamilton County, OH FRM 

monitors have consistently had higher PM2.5 averages than the Campbell and Kenton 

County, KY monitors. 

 

Regionally, PM2.5 concentrations are near the annual standard for the period 1999-2006 

in KY, IN, OH, and WV. The Louisville, Cincinnati, and Huntington-Ashland 

nonattainment areas have levels that are incremental higher than the regional averages do 

to local contributions.
Kentucky Conceptual Description April 15, 2008 5

Figure 2.1-4. Quarterly and Annual Average PM2.5 mass for Federal Reference Method 

(FRM) monitors in Louisville, KY-IN non-attainment area for 1999-2006. 

Louisville (37-Southern Ave.)/Jefferson Co., KY (21-111-0043) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3)

Louisville (Wyandotte Park)/Jefferson Co., KY (21-111-0044) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3)

Louisville (Barret Ave.)/Jefferson Co., KY (21-111-0048) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3)

Shepherdsville/Bullitt Co., KY (21-029-0006) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3)

Quarterly Averages Annual Average
Kentucky Conceptual Description April 15, 2008 6

Figure 2.1-4 (continued). Quarterly and Annual Average PM2.5 mass for Federal 

Reference Method (FRM) monitors in Louisville, KY-IN area for 1999-2006. 

Jeffersonville (Spring St.)/Clark County, IN (18-019-0005) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Jeffersonville (Walnut St.)/Clark County, IN (18-019-0006) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

New Albany/Floyd County, IN (18-043-1004) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Quarterly Averages Annual Average

Louisville (Watson Lane)/Jefferson County, KY (21-111-0051) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)
Kentucky Conceptual Description April 15, 2008 7

Figure 2.1-4. Quarterly and Annual Average PM2.5 mass for selected Federal Reference 

Method (FRM) monitors in the Cincinnati-Hamilton, KY-IN-OH area for 1999-2006. 

Cincinnati (Seymour)/Hamilton County, OH (39-061-0014) FRM Mass

0

5

10

15

20

25

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Fort Thomas/Campbell County, KY (21-037-0003) FRM Mass

0

5

10

15

20

25

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Covington/Kenton County, KY (21-117-0007) FRM Mass

0

5

10

15

20

25

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

St. Bernard/Hamilton County, OH (39-061-8001) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Quarterly Averages Annual Average
Kentucky Conceptual Description April 15, 2008 8

Figure 2.1-6. Quarterly and Annual Average PM2.5 mass for Federal Reference Method 

(FRM) monitors in the Huntington-Ashland, KY-OH-WV area for 1999-2006. 

Ironton/Lawrence County, OH (39-087-0010) FRM Mass

0

5

10

15

20

25

1999 4 2 2001 4 2 2003 4 2 2005 4 2

PM2.5 (μg/m3

)

New Boston/Scioto County, OH (39-145-0013) FRM Mass

0

5

10

15

20

25

30

1999 4 2 2001 4 2 2003 4 2 2005 4 2

PM2.5 (μg/m3

)

Quarterly Averages Annual Average

Cabell Co, WV (54-011-0006) FRM Mass

0

5

10

15

20

25

30

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)

Ashland/Boyd County, KY (21-019-0017) FRM Mass

0

5

10

15

20

25

1234 1234 1234 1234 1234 1234 1234 1234

1999 2000 2001 2002 2003 2004 2005 2006

PM2.5 (μg/m3

)
Kentucky Conceptual Description April 15, 2008 9

2.2 Speciated PM2.5 Data for Kentucky Non-attainment Areas 

EPA’s Speciated Trend Network (STN) PM2.5 monitors collect filter-based 24-hr 

samples every third or sixth day; filters are analyzed to provide total PM2.5 mass and 

mass of individual. Quarterly average speciated PM2.5 data for STN monitors in the 

Kentucky non-attainment areas are illustrated in Figure 2.2-1. PM2.5 composition is 

similar for other STN sites in these nonattainment areas. PM2.5 measurements are 

separated into several components: sulfate (SO4), nitrate (NO3), ammonium (NH4), 

particulate organic matter (POM), elemental carbon (EC), and crustal materials. Sulfate 

(SO4) and particulate organic matter (POM, also called Organic Carbon, OC) are the 

dominant contributors to PM2.5 mass in these nonattainment areas. Sulfate peaks in the 

third quarter are primarily responsible for the peak PM2.5 values in the third quarter. 

Sulfate levels are highest in the third quarter and lowest in the first and fourth quarters, 

ranging spatially and seasonally from 3-10 μg/m3. 

In contrast, organic carbon levels are fairly constant across the quarters, varying spatially 

and seasonally from 3-7 μg/m3. Organic carbon speciation data from Mammoth Cave, 

KY indicate greater contributions from primary carbon (combustion of fossil fuels, 

biomass burning, vegetative detritus, and cooking) in the winter months and greater 

contributions from secondary organic aerosol (from biogenic and anthropogenic 

emissions) during the summer months. Organic carbon speciation in urban areas 

suggests higher contributions from fuel combustion from mobile sources and primary 

carbon sources than in the Class I areas. Spatial variation in OC can be seen on the local 

scale by comparing quarterly averages across the Jefferson County STN monitors (21-

111-0043 and -0048 illustrated in Figure2.2-1). 

Nitrate (NO3) has a significant contribution to PM2.5 in the KY nonattainment areas, 

particularly in the first quarter. Ammonium (NH4) is associated with sulfate or nitrate. 

Higher amounts of NO3 are present in the cooler months, with very low concentrations in 

the third quarter. Ammonium nitrate (NH4NO3) formation is a temperature-limited 

process with particle formation favored at lower temperatures. At higher temperatures 

nitrogen oxides remain in gaseous form as nitric acid. NH4NO3 levels are higher in KY 

than in other nonattainment areas in the southeastern US, in part due to cooler winter time 

temperatures and in part due to closer proximity to the large source region for ammonia 

in the midwestern and central states. The EC and crustal components of PM2.5 are 

generally small contributors to the total PM2.5 mass. The difference between total 

measured PM2.5 and reconstructed PM2.5 is attributed to other components such as 

metals or particle bound water. 

Secondary pollutants (SO4, NO3, and OC) are the major contributors to PM2.5. Primary 

components (EC, soil) are relatively minor contributors. Thus precursors of secondary 

components (e.g. SO2, NOx, biogenic VOC) are more important contributors to PM2.5 

mass than primary PM2.5 sources. The exception is seen when a local source of primary 

PM is located in close proximity to the monitor. 

 
Kentucky Conceptual Description April 15, 2008 10

Figure 2.2-1. Quarterly and Annual Average Contributions to total measured PM2.5 

mass at representative STN sites in the Louisville, KY, Cincinnati, OH-KY and 

Huntington-Ashland, KY-OH-WV nonattainment areas. 

Louisville (37th and Southern Ave.)/Jefferson County, KY (21-111-0043)

0

5

10

15

20

25

30

123412341234123412341234

2001 2002 2003 2004 2005 2006

STN Mass (μg/m3)

Other

Soil

LAC

POM

NO3

NH4

SO4

Ann. Avg.

Louisville (Barret Ave.)/Jefferson County, KY (21-111-0048)

0

5

10

15

20

25

30

123412341234123412341234

2001 2002 2003 2004 2005 2006

STN Mass (μg/m3)

Other

Soil

LAC

POM

NO3

NH4

SO4

Ann. Avg.

Covington/Kenton County, KY (21-117-0007)

0

5

10

15

20

25

30

123412341234123412341234

2001 2002 2003 2004 2005 2006

STN Mass (μg/m3)

Other

Soil

LAC

POM

NO3

NH4

SO4

Ann. Avg.

Ashland/Boyd County, KY (21-019-0017)

0

5

10

15

20

25

30

123412341234123412341234

2001 2002 2003 2004 2005 2006

STN Mass (μg/m3)

Other

Soil

LAC

POM

NO3

NH4

SO4

Ann. Avg.
Kentucky Conceptual Description April 15, 2008 11

Air quality model projections using the Community Model of Air Quality (CMAQ) for 

2002 for the VISTAS 12-km domain (reference VISTAS Modeling Technical Support 

Document, 2007, ENVIRON) provide insight into the spatial variability across the KYIN-OH-WV nonattainment areas. Spatial plots show that annual average PM2.5 levels 

are higher along the Ohio River and north into OH and IN than in the rest of the state of 

Kentucky (Figures 2.2-2). The annual average sulfate spatial plot shows higher spatial 

variability than PM2.5 with high sulfate concentrations in the vicinity of major point 

source regions along the Ohio River and the WV Panhandle (Figure 2.2-3). In contrast, 

annual average organic carbon levels are fairly constant across Kentucky with locally 

elevated levels in the Louisville and Huntington-Ashland nonattainment areas (Figure 

2.2-4). 

Figure 2.2-2. 2002 Annual average PM2.5 concentrations modeled by CMAQ for 

VISTAS 12 km modeling domain. 
Kentucky Conceptual Description April 15, 2008 12

Figures 2.2-3 and 2.2-4. 2002 Annual average sulfate and organic carbon concentrations 

modeled by CMAQ for VISTAS 12 km modeling domain. 
Kentucky Conceptual Description April 15, 2008 13

The CMAQ model can also be used to evaluate source contributions to organic carbon in 

the Kentucky nonattainment areas. For example, at the Louisville monitor (21-111-

0043), the majority of carbon in the first and fourth quarters is primary carbon with 

smaller contributions from primary carbon in the second and fourth quarters. Secondary 

organic carbon from biogenic sources is most important in the second and third quarters. 

The model suggests that there is little secondary organic carbon formed from 

anthropogenic emissions. The model also suggests that the contributions of organic 

carbon to PM2.5 are little changed between 2002 and 2009. 

Collectively, these monitoring and modeling results confirm the conclusion that 

emissions control strategies to reduce emissions of SO2 contributing to sulfate would be 

most effective in reducing PM2.5 in Kentucky nonattainment areas. Reducing 

anthropogenic emissions of primary PM2.5 contributing to particulate organic matter and 

of nitrous oxides and ammonia contributing to ammonium nitrate would likely reduce 

PM2.5 concentrations more on winter days than summer days. 

3.0 Meteorological Contributions to PM2.5 Concentrations 

Classification and Regression Tree Analyses were used to characterize the relationship 

between meteorological conditions and elevated PM2.5 concentrations for the period 

2000-2004 for several STN sites in the southeastern states. Days were assigned to one of 

four classes based on PM2.5 concentration (Class 1 days with PM2.5 mass less than 20 

μg/m3; Class 4 days with PM2.5 mass greater than 37.5 μg/m3). Days in each class were 

CMAQ Modeled Organic Matter- Jefferson County, KY (21-111-0043)

0

0.5

1

1.5

2

2.5

3

3.5

2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2

Q1 Q2 Q3 Q4 Ann

μg/m3

POM

PSOM

SOMB

SOMA

POM: Primary OM, PSOM: Polymerized Secondary OM

SOMB: Biogenic Secondary OM, SOMA: Anthropogenic Secondary OM

CMAQ Modeled Organic Matter- Jefferson County, KY (21-111-0043)

0

0.5

1

1.5

2

2.5

3

3.5

2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2 2002gt2 2009gt2

Q1 Q2 Q3 Q4 Ann

μg/m3

POM

PSOM

SOMB

SOMA

POM: Primary OM, PSOM: Polymerized Secondary OM

SOMB: Biogenic Secondary OM, SOMA: Anthropogenic Secondary OM
Kentucky Conceptual Description April 15, 2008 14

then assigned to bins based on meteorological conditions, with days in the same bin 

sharing similar meteorological characteristics. Across the southeastern US, days with 

elevated PM2.5 concentrations most frequently occurred on days with high temperatures, 

high relative humidity, low wind speeds, and elevated PM2.5 mass on the previous day at 

upwind urban areas. This is illustrated for the Louisville and the Huntington-Ashland 

areas in Figures 3.1-1 and 3.1-2. On high PM2.5 mass days (Class 3 and 4), sulfate and 

organic carbon are elevated compared to days with lower PM2.5 mass (Class 1) as 

illustrated in Figures 3.3-3 and 3.3-4. Elevated nitrate on some Class 2 days indicates 

winter days for which nitrate is elevated but overall PM2.5 mass is comparatively low. 

Elemental carbon is a small fraction of fine mass on all days. 

Figure 3.1-1. Results of Classification and Regression Tree analyses demonstrating the 

influence of meteorological conditions on PM2.5 mass concentrations for the Louisville 

non-attainment area. YFM=yesterday fine mass. 

CATEGORICAL COMPARISONS FOR 

PM2.5: LOUISVILLE

0

5

10

15

20

25

30

35

40

T (deg C) YFM (μgm-3)

<20 20-27.5 27.5-37.5 >=37.5

0

1

2

3

4

WS (m/s)

<20 20-27.5 27.5-37.5 >=37.5

0

90

180

270

360

WD (deg)

<20 20-27.5 27.5-37.5 >=37.5

0

20

40

60

80

100

RH (%)

<20 20-27.5 27.5-37.5 >=37.5

*

Surface Characteristics: All Days (2000-2004)/4 PM2.5 Conc. Categories (μgm-3)
Kentucky Conceptual Description April 15, 2008 15

Figure 3.1-2. Results of Classification and Regression Tree analyses demonstrating the 

influence of meteorological conditions on PM2.5 mass concentrations for the 

Huntington/Ashland non-attainment area. YFM=yesterday fine mass. 

Figure 3.1-3. Contributions of PM2.5 components in key bins for 4 classes of days 

defined by PM2.5 total mass at Louisville, KY (Class 1 =<17.5, Class 2 =17.5-25, Class 

3 = 25-32.5, Class 4 = >32.5 μg/m3) 

CATEGORICAL COMPARISONS FOR 

PM2.5: HUNTINGTON/ASHLAND

0

5

10

15

20

25

30

35

T (deg C) YFM (μgm-3)

<17.5 17.5-25 25-32.5 >=32.5

0

1

2

3

4

WS (m/s)

<17.5 17.5-25 25-32.5 >=32.5

0

90

180

270

360

WD (deg)

<17.5 17.5-25 25-32.5 >=32.5

0

20

40

60

80

100

RH (%)

<17.5 17.5-25 25-32.5 >=32.5

*Cincinnati

*

Surface Characteristics: All Days (2000-2004)/4 PM2.5 Conc. Categories (μgm-3)

Louisville Key PM Bins: Component Averages

0.00

4.00

8.00

12.00

16.00

20.00

24.00

1 (724) 3 (153) 10 (104) 12 (79) 2 (31) 4 (28) 15 (12) 30 (13) 17 (15) 24 (26) 25 (7) 29 (6)

Class 1 Class 2 Class 3 Class 4

Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3)

EC

NO3

OM

SO4
Kentucky Conceptual Description April 15, 2008 16

Figure 3.1-4. Contributions of PM2.5 components in key bins for 4 classes of days 

defined by PM2.5 total mass at Huntington-Ashland, KY-WV (Class 1 =<17.5, Class 2 

=17.5-25, Class 3 = 25-32.5, Class 4 = >32.5 μg/m3) 

4.0 Emissions Contributing to PM2.5 Concentrations 

Point source (electric utility and industry) SO2 emissions are the predominant precursors 

for ammonium sulfate, accounting for 96-98% of the total SO2 emissions in 2002 in the 

Kentucky nonattainment areas. (See Appendix E, Emissions Inventory Summary Tables) 

Ground level and point sources of nitrogen oxides and agricultural emissions of ammonia 

are the primary precursors for ammonium nitrate. Fossil fuel combustion and wood 

burning are the most important contributors to elemental carbon. Fine soil might be from 

construction or agricultural activities or windblown dust. 

A combination of sources contribute to organic carbon mass, including wood burning, 

vegetative emissions, and fossil fuel combustion by industrial point sources, on road 

vehicles, and non road engines, and meat cooking. Carbon isotope studies indicated that 

modern sources of carbon, e.g. wood burning and vegetative emissions, are larger 

contributors to measured carbon than fossil (anthropogenic) sources of carbon (e.g. 

gasoline, diesel, coal). Elevated levels of carbon in the winter are likely due to wood 

burning (from forest fires, prescribed fires, land clearing, agricultural burning, or 

residential, commercial or industrial wood use). Elevated levels in summer are likely due 

to vegetative carbon emissions. Contributions from fossil fuel combustion (gasoline and 

diesel) are greater in urban areas than in rural areas. 

4.1 Emissions Sensitivity Analyses 

To evaluate changes in PM2.5 mass loadings in response to changes in 2009 emissions 

from specific source and pollutant categories, emissions sensitivities were run using the 

CMAQ regional air quality model, the ASIP 2009 Base D inventory, and episodes 

selected in summer (Jun 1-Jul 10) and late fall (Nov 19-Dec 19) 2002. These episodes 

Huntington-Ashland Key PM Bins: Component Averages

0.00

4.00

8.00

12.00

16.00

20.00

8 (243) 7 (40) 5 (22) 29 (20) 28 (20) 1 (14) 6 (11) 13 (10) 14 (10) 12 (8) 23 (9)

Class 1 Class 2 Class 3 Class 4

Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3)

EC

NO3

OM

SO4
Kentucky Conceptual Description April 15, 2008 17

were selected using CART analyses (see section 3) to represent the annual 2002 baseyear 

conditions. Emissions in 2009 for several combinations of pollutants and source sectors 

were reduced by 30 percent in separate sensitivity runs for each state in the VISTAS 

region and for the other RPOs in the VISTAS 12 km modeling grid. The pollutant 

contributions that were evaluated were: 

• SO2 from Electric Generating Units (EGU) sources in each VISTAS state, other 

RPOs in the VISTAS 12 km grid, and Boundary Conditions from outside the 12 

km domain. 

• SO2 from non-EGU point sources in each VISTAS state, other RPOs, and 

Boundary Conditions 

• NOx from ground level (on-road plus non-road plus area) sources in each 

VISTAS state and other RPOs 

• NOx from point (EGU plus non-EGU) sources in each VISTAS state and other 

RPOs 

• NH3 from all sources in VISTAS and other RPOs 

• Volatile Organic Compounds from anthropogenic and biogenic sources in the 12 

km modeling domain 

• Primary Carbon from all ground level sources in each VISTAS state and other 

RPOs 

• Primary Carbon from all point sources in each VISTAS state and other RPOs 

• Primary Carbon from all fires in each VISTAS state and other RPOs 

Sensitivity results for the summer and winter episodes and for annual average PM2.5 

(calculated using CART weighting factors for representative days in the modeled 

episodes) are illustrated in Figures 4.1-1 through 4.1-3 for Louisville, KY, in Figures 4.1-

4 through 4.1-6 for Cincinnati (Kenton County, KY), and in Figures 4.1-7 through 4.1-9 

for Huntington-Ashland. Contributions modeled for these sites are very similar to 

contributions projected for other monitoring site in the same nonattainment area. 

The first observation from these data is that the responses to emissions reductions are 

larger in the summer than in the winter. The greatest reductions in PM2.5 mass would be 

accomplished by further reducing SO2 emissions from electric utilities and industrial 

point sources beyond 2009 levels. For the Louisville and Cincinnati nonattainment areas, 

SO2 reductions from EGU in KY and the MRPO states would have the greatest benefits. 

For the Huntington-Ashland area, SO2 reductions from KY, TN, and WV would have the 

greatest benefits. SO2 reductions from EGU and non-EGU in other southeastern states 

would also be beneficial in reducing PM2.5 in the KY nonattainment areas. The largest 

response to SO2 emissions reductions in the winter is projected from SO2 emissions 

outside the ASIP 12 km modeling domain (Boundary Conditions). SO2 emissions from 

outside the 12 km domain are a significant, but smaller contribution in the summer 

episode. This suggests that continental and/or intercontinental transport of SO2 emissions 

can have impacts comparable to or greater than impacts from local sources of NOx or 

primary carbon. 
Kentucky Conceptual Description April 15, 2008 18

The model projects very little benefit to total PM2.5 of reducing emissions of nitrogen 

oxides from either ground or point sources in Kentucky in either winter or summer. In 

the Southeast, ammonium nitrate levels are generally limited by availability of ammonia, 

so reducing ammonia emissions would be a more effective strategy to reduce ammonium 

nitrate than reducing nitrogen oxide emissions. 

In both summer and winter the model projects some benefits from reducing local sources 

of primary carbon from ground (on road vehicles, off road engines, area sources) and 

point (industrial and electric utility) sources and from fire emissions. Ground sources of 

primary PM are more important in Louisville and Cincinnati than in Huntington-Ashland 

and more important than point sources in all areas. Because biogenic emissions dominate 

Volatile Organic Carbon (VOC) emissions, the model indicates little reduction in total 

PM2.5 in winter and no reduction in summer from reducing anthropogenic VOC 

emissions. 

In summary, SO2 reductions from electric utilities and industrial point sources are likely 

to be most effective in reducing PM2.5 in Kentucky nonattainment areas. From the 

mobile sector, reductions of primary carbon from local sources would be more effective 

than reductions of either VOC or NOx. 

 
Kentucky Conceptual Description April 15, 2008 19

Figures 4.1-1 and 4.1-2. CMAQ modeled responses to 30% reductions in 2009 emissions 

of SO2, NOx, NH3, VOC, and Primary Carbon from VISTAS states, neighboring 

Regional Planning Organizations, and boundary conditions for Summer and Winter 

episodes in 2002 for Louisville, KY. 

Louisville, KY (21-111-0043) Summer

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Louisville, KY (21-111-0043) Summer

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Louisville, KY (21-111-0043) Winter

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Louisville, KY (21-111-0043) Winter

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL
Kentucky Conceptual Description April 15, 2008 20

Figures 4.1-3 and 4.1-4. CMAQ modeled responses to 30% reductions in 2009 emissions 

of SO2, NOx, NH3, VOC, and Primary Carbon from VISTAS states, neighboring RPOs, 

and boundary conditions for Annual Average PM2.5 for Louisville, KY and Summer 

episode for Kenton Co, KY (Cincinnati nonattainment area). 

Louisville, KY (2-1111-0043) Annual

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Louisville, KY (2-1111-0043) Annual

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

ΔPM2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Kenton Co., KY (Cincinnati) (21-117-0007) Summer

-1.40

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Kenton Co., KY (Cincinnati) (21-117-0007) Summer

-1.40

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

) -1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL
Kentucky Conceptual Description April 15, 2008 21

Figures 4.1-5 and 4.1-6. CMAQ modeled responses to 30% reductions in 2009 emissions 

of SO2, NOx, NH3, VOC, and Primary Carbon from VISTAS states, neighboring RPOs, 

and boundary conditions for Winter 2002 for Kenton Co, KY (Cincinnati nonattainment 

area) and Summer 2002 for Boyd Co, KY (Huntington-Ashland nonattainment area). 

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Kenton Co., KY (Cincinnati) (21-117-0007) Winter

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

) -1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Kenton Co., KY (Cincinnati) (21-117-0007) Winter

Huntington-Ashland, KY-OH-WV (21-019-0017) Summer

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Huntington-Ashland, KY-OH-WV (21-019-0017) Summer

0.20

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

) -1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL
Kentucky Conceptual Description April 15, 2008 22

Figures 4.1-7 and 4.1-8. CMAQ modeled responses to 30% reductions in 2009 emissions 

of SO2, NOx, NH3, VOC, and Primary Carbon from VISTAS states, neighboring RPOs, 

and boundary conditions for Winter 2002 and Annual Average PM2.5 for Boyd Co, KY 

(Huntington-Ashland nonattainment area). 

Huntington-Ashland, KY-OH-WV (21-019-0017) Winter

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Huntington-Ashland, KY-OH-WV (21-019-0017) Winter

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m3

) -1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Huntington-Ashland, KY-OH-WV (21-019-0017) Annual

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL

Huntington-Ashland, KY-OH-WV (21-019-0017) Annual

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC_Fires

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

) -1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

ΔPM 2.5 (μg/m 3

)

Bio. VOC

Anthro. VOC

BCs

MRPO

MANE-VU

CENRAP

VISTAS

WV

VA

TN

SC

NC

MS

KY

GA

FL

AL
Kentucky Conceptual Description April 15, 2008 23

5.0 Summary 

In summary, sulfate and particulate organic matter are the most important contributors to 

PM2.5 in the Kentucky nonattainment areas. PM2.5 composition and mass are similar 

across the monitoring sites. Sulfate and carbon can be elevated due to contributions from 

local sources. Emissions sensitivity results demonstrate the greatest benefits in reducing 

PM2.5 from further reducing SO2 emissions from electric utilities and industrial point 

sources. Benefits of reducing primary carbon emissions from ground sources are 

projected to be greater than reducing primary carbon from point sources, however this 

does not consider the difficulty in implementing controls for mobile versus point sources. 

Reducing regional emissions of ammonia is projected to reduce wintertime nitrate levels.