Attachment 1

Indiana Area Designations For the 

24-Hour Fine Particle National Ambient Air Quality Standard

The table below identifies the counties in Indiana that EPA has
designated as not attaining the 2006 24-hour fine particle (PM2.5)
standard.  A county or part thereof is designated as nonattainment if it
has an air quality monitor that is violating the standard or if the
county is determined to be contributing to the violation of the
standard.

 

Area 	Indiana Recommended Nonattainment Counties	EPA’s Designated
Nonattainment Counties

Chicago, IL-IN	Lake	Lake

Porter

Cincinnati, OH-KY-IN	None	Dearborn* (partial)

Evansville, IN-KY	Vanderburgh	Gibson* (partial)

Pike* (partial)

Spencer* (partial)

Vanderburgh

Warrick

Indianapolis, IN	Marion	Hamilton

Hendricks

Johnson

Marion

Morgan

Lafayette, IN	Tippecanoe	Tippecanoe

Louisville, KY-IN	Clark	Clark

Floyd

Jefferson* (partial)

Vincennes, IN	Knox	Knox

* The Indiana partial county boundaries are Dearborn- Lawrenceburg
Township, Gibson- Montgomery Township, Pike- Washington Township,
Spencer- Ohio Township, and Jefferson- Madison Township. 

 

EPA has designated the remaining counties in the state as
“attainment/unclassifiable.”  

General Comments on Size of Nonattainment Areas

Indiana recommended that each county measuring a violation be designated
as a single county nonattainment area.  In EPA’s letter to Indiana
dated August 18, 2008, EPA provided its rationale for designating
multi-county nonattainment areas in many cases.  Indiana provided
further comments on this issue in its letter to EPA dated October 20,
2008, and EPA has provided detailed responses to these comments in its
response to comments document.  For the reasons EPA has given in those
two documents, EPA continues to believe that many counties in Indiana
that do not themselves have monitored violations must nevertheless be
designated as contributing to nearby violations.

Review for Chicago-Gary-Kenosha, IL-IN-WI 

EPA reviewed the relevant information for the ten counties including two
counties in Indiana within the area designated nonattainment for the
1997 standards as well as for surrounding counties.  There are violating
monitors in Lake County, Indiana as well as in Cook and Will Counties in
Illinois.  Indiana recommended that Lake County be designated as a
single county nonattainment area, and Indiana recommended that Porter
County and other counties in and near the Chicago area be designated
attainment.

EPA believes that two Indiana counties, namely Lake and Porter Counties,
should be included in the Chicago nonattainment area.  Lake County not
only violates the standard, it also contributes to violations in Cook
and Will Counties, Illinois.  Porter County also has substantial
emissions that contribute to violations elsewhere in the Chicago
metropolitan area on a high percentage of days.  Both Lake and Porter
Counties have high numbers of commuters that drive into other parts of
the Chicago metropolitan area.  In addition, establishment of a
nonattainment area for the 2006 standards that matches the existing
nonattainment area boundaries set for the 1997 standards will simplify
planning by assuring that the corresponding requirements for the two
sets of air quality standards apply to the same area.

EPA reviewed the relevant information for other counties within the
combined statistical area as well as counties adjacent to the combined
statistical area in order to determine the appropriate nonattainment
area.  Jasper County has moderate emission levels, but was excluded from
the nonattainment area because the other factors indicated it does not
contribute to the violations in the Chicago area.  Other Indiana
counties in or near the combined statistical area have relatively low
emissions, and no other factor warranted inclusion of the counties in
the nonattainment area.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

For this area, EPA previously established PM2.5 nonattainment boundaries
for the 1997 PM2.5 NAAQS that included ten full and partial counties,
with eight being located in Illinois and two in Indiana.

In its December 18, 2007 letter, Illinois recommended that the same full
and partial counties in the Chicago area be designated as
“nonattainment” for the 2006 24-hour PM2.5 standard based on air
quality data from 2004-2006.  These data are from Federal Reference
Method (FRM) monitors located in the state.  Indiana recommended Lake
County be designated as “nonattainment” for the 2006 24-hour PM2.5
standard based on air quality data in its May 30, 2008 letter.

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  Indiana provided
information on planned controls throughout the state, but this
information did not indicate any significant differences between current
emissions and emission estimates from the 2005 inventory for this area. 
Indiana also provided lengthy additional comments, including a review of
information pertinent to EPA’s nine factors reflecting information
generally quite similar to EPA’s information.  EPA discusses these
comments below and in the Response to Comments document.

Based on EPA's technical analysis described below, EPA has designated
six full and two partial counties in Illinois and two Indiana counties
as nonattainment for the 24-hour PM2.5 air-quality standard as the
Chicago nonattainment area, based upon currently available information. 
These counties are listed in the table below.

The following is a review of data for relevant factors for the Chicago
area.

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Chicago area.  Counties that are part of
the Chicago nonattainment area for the 1997 PM2.5 NAAQS are shown in
boldface.  Counties are listed in descending order by CES.

Table 1.  PM2.5 24-hour Component Emissions, and CESs. 

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx	VOCs	NH3

Cook, IL	Yes	100	10,081	5,407	4,674	35,354	175,267	152,288	4,550

Lake, IN	No	100	7,079	1,219	5,861	39,500	54,203	24,679	3,784

Will, IL	Yes	95	5,432	1,236	4,195	78,792	46,028	19,886	1,407

Porter, IN	No	41	3,901	719	3,183	24,458	29,930	9,795	909

DuPage, IL	Yes	16	2,075	1,259	816	2,013	36,880	29,541	1,385

Jasper, IN	No	14	2,641	280	2,360	40,723	20,104	3,367	2,929

Kankakee, IL	No	9	1,660	419	1,242	366	7,351	6,830	1,699

Kane, IL	Yes	4	1,997	733	1,263	1,037	16,528	15,578	1,293

Grundy, IL	Partial	3	1,105	248	857	362	4,057	4,223	1,027

Lake, IL	Yes	3	2,657	1,070	1,587	14,719	29,478	32,778	747

Kendall, IL	Partial	2	811	230	581	351	3,697	3,693	753

McHenry, IL	Yes	1	2,102	634	1,468	592	9,493	10,596	1,224

Kenosha, WI	No	1	1,489	460	1,030	33,988	15,967	7,857	647



In the Indiana portion of the area, emissions are highest in Lake and
Porter Counties.  Emissions are lower in Jasper County, but still high
enough to merit consideration for nonattainment under this factor.  Lake
and Porter Counties are the best candidates in Indiana for a 24-hour
PM2.5 nonattainment designation.

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Cook, IL	100	97	72	15.8

Lake, IN	100	100	100	32.5

Will, IL	95	92	68	25.0

Porter, IN	41	84	87	42.4

DuPage, IL	16	81	50	17.5

Jasper, IN	14	58	69	64.9

Kankakee, IL	9	72	60	46.6

Kane, IL	4	42	17	36.1

Grundy, IL	3	56	28	50.1

Lake, IL	3	35	8	37.9

Kendall, IL	2	58	28	38.1

McHenry, IL	1	19	4	50.5

Kenosha, WI	1	15	1	55.4



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Chicago area based on data for
the 2005-2007 period.  A monitor’s design value indicates whether that
monitor attains a specified air quality standard.  The 24-hour PM2.5
standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met. 

The 24-hour PM2.5 design values for counties in the Chicago area are
shown in Table 3.

	Table 3.  Air Quality Data

County	State 

Recommended

Nonattainment?	Design Values

2004-2006	Design Values

2005-2007

Cook, IL	Yes	42	40

Lake, IN	No	38	37

Will, IL	Yes	36	37

Porter, IN	No	31	32

DuPage, IL	Yes	33	35

Kane, IL	Yes	32	35

Grundy, IL	Partial



Lake, IL	Yes	33	35

Kendall, IL	Partial



McHenry, IL	Yes	31	31



Three counties, Cook and Will in Illinois and Lake in Indiana, show
violations of the 24-hour PM2.5 standard.  Therefore, these counties are
included in the Chicago nonattainment area.  However, the absence of a
violating monitor alone is not a sufficient reason to eliminate counties
as candidates for nonattainment status.  Each county has been evaluated
based on the weight of evidence of the nine factors and other relevant
information.

For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Chicago area occur about 47% in the warm
season and 53% in the cool season.  In the warm season, the average
chemical composition of the highest days is 72% sulfate, no nitrate, 25%
carbon, and 3% crustal.  In the cool season, the average chemical
composition of the highest days is 21% sulfate, 39% nitrate, 38% carbon,
and 2% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards. 

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/mi2)

Cook, IL	Yes	 5,303,943 	5545

Lake, IN	No	    491,706 	980

Will, IL	Yes	    642,625 	758

Porter, IN	No	    157,408 	375

DuPage, IL	Yes	    931,219 	2769

Kane, IL	Yes	    483,208 	923

Grundy, IL	Partial	     43,736 	102

Lake, IL	Yes	    704,086 	1504

Kendall, IL	Partial	     79,597 	247

McHenry, IL	Yes	    304,701 	499

Kankakee, IL	No	    107,824	158



In the Indiana portion of the Chicago area, Lake County has a sizable
population and population density.  Both are more moderate in Porter
County, but still larger that other area counties designated as
nonattainment.  Jasper County has a small population of 31,761 and a low
population density of 57 people per mile squared suggesting it is a
mostly rural area.

Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Chicago area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.  

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating county 	Percent

Commuting to any violating county 	Number Commuting within statistical
area 	Percent

Commuting within statistical area 

Cook, IL	Yes	    35,294 	2,113,930 	89	  2,352,120 	99

Lake, IN	No	     4,588 	193,610 	93	    206,350 	99

Will, IL	Yes	     4,605 	185,690 	77	    239,340 	99

Porter, IN	No	     1,677 	25,470 	35	      70,940 	98

DuPage, IL	Yes	     8,802 	161,940 	35	    464,630 	99

Kane, IL	Yes	     3,517 	36,290 	19	    190,780 	99

Grundy, IL	Partial	        623 	6,990 	38	      17,310 	95

Lake, IL	Yes	     6,016 	83,930 	26	    313,250 	99

Kendall, IL	Partial	        678 	4,230 	15	      27,860 	99

McHenry, IL	Yes	     2,104 	31,680 	24	    130,520 	98



The listing of counties on Table 5 reflects a ranking based on the
number of people commuting to other counties.  The counties that are in
the nonattainment area for the 1997 PM2.5 NAAQS are shown in boldface. 
All counties in this table are highly integrated into the Chicago area. 
Therefore, Lake and Porter Counties, Indiana are good candidates for the
nonattainment area when considering the commuting factor.  EPA also
examined data for Jasper County.  Its annual VMT is 757 million miles
and the number of workers commuting to violating counties is 2,920. 
These very low commuting figures indicate that Jasper County is a poor
candidate for nonattainment based on this factor. 

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Chicago area, as
well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Chicago area.  Counties are listed
in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Growth and Percent Change.

County	Population (2005)	Population % change (2000-05)	2005 VMT

(106 mi)	VMT % change

(1996-2005)

Kane, IL	    483,208 	18 	     3,517 	        364 

McHenry, IL	    304,701 	16 	     2,104 	        196 

Kendall, IL	     79,597 	44 	        678 	        166 

Will, IL	    642,625 	26 	     4,605 	        135 

Lake, IL	    704,086 	9 	     6,016 	          82 

DuPage, IL	    931,219 	3 	     8,802 	          43 

Grundy, IL	     43,736 	16 	        623 	          30 

Porter, IN	    157,408 	7 	     1,677 	          10  

Lake, IN	    491,706 	1 	     4,588 	            0

Cook, IL	 5,303,943 	-1	    35,294 	         -14



Lake and Porter Counties, Indiana experienced little population and VMT
growth.  The growth rates are not expected to yield significant changes
in the distribution of population in the area, so this factor did not
significantly influence the decision-making process.

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for the Chicago area is provided in Figure 2.  Winds
on high concentration days predominantly come from the southwest and
southeast, thus suggesting that winds on many days would bring Lake and
Porter County emissions into Illinois and, on many other days, would
bring Illinois emissions into Lake and Porter Counties.  Thus, this
factor supports designation of a joint Illinois-Indiana nonattainment
area.

 Figure 2

 

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area.

The Chicago area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  Analysis of
chemical composition data in these areas indicates that the same
components that make up most of the PM2.5 mass in the area on an annual
average basis such as sulfate and direct PM2.5 carbon in many eastern
areas also are key contributors to the PM2.5 mass on days exceeding the
24-hour PM2.5 standard.  These data indicate that in many cities, the
same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

EPA has generally concluded that counties that were designated as having
emissions sources contributing to fine particle concentrations which
exceeded the 1997 standards (all areas violated the annual standard, two
also violated the previous 24-hour standard) also contribute to fine
particle concentrations on the highest days.  For this reason, EPA
believes that for most existing nonattainment areas, the nonattainment
area for the 2006 24-hour standard should be the same.  Consideration
also should be given to existing boundaries and organizations as they
may facilitate air quality planning and the implementation of control
measures to attain the standard.  Areas already designated as
nonattainment represent important boundaries for state air quality
planning.

The Chicago ozone nonattainment area consists of the following counties:
 Cook, Du Page, Kane, Lake, Mc Henry, Will, Aux Sable and Goose Lake
Townships in Grundy County, and Oswego Township in Kendall County in
Illinois and Lake and Porter Counties in Indiana.  The fine particulate
nonattainment area matches these boundaries, which will facilitate
planning.  It is also identical to the fine particulate nonattainment
area designed under the 1997 standards.

The Chicago Area Transportation Study (CATS) Policy Committee is the
Metropolitan Planning Organization (MPO) for the northeastern Illinois
region.  CATS webpage:   HYPERLINK "http://www.catsmpo.com/" 
http://www.catsmpo.com/ .  Northwest Indiana has a separate MPO called
the Northwest Indiana Regional Planning Commission (NIRPC), serving
Lake, Porter, and LaPorte Counties, with a web site at:   HYPERLINK
"http://www.nirpc.org/"  http://www.nirpc.org/ .

Jasper County was not included in any of previous nonattainment areas
and not in the NIRPC.  This factor suggests Lake and Porter Counties for
nonattainment in the Indiana portion of the Chicago area.  It also
suggests against including Jasper County.

 

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Chicago area before 2005 on stationary, mobile, and area sources.
 Data are presented for PM2.5 components that are directly emitted,
carbonaceous PM2.5 and crustal PM2.5, and for pollutants which react in
the atmosphere to form fine particles such as SO2, NOx, VOC, and
ammonia.  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational. 

Wisconsin provided information on a power plant in Kenosha County,
Wisconsin.  This is immediately north of the Chicago nonattainment area.
 EPA determined that the Kenosha County facility is well controlled. 
The emission controls are federally enforceable.  Kenosha County is not
considered to contribute to violations in the Chicago area with the
updated emissions information and the information on the other eight
factors.  Therefore, EPA determined that including Kenosha County in the
Chicago nonattainment area is not warranted.  Further information on
Kenosha County emissions is provided in discussion of the Milwaukee
area.  

Indiana provided information on planned controls throughout the state,
but this information did not indicate any significant differences
between current emissions and emission estimates from the 2005 inventory
for this area.

Note: EPA has provided a thorough response to each of the specific
comments raised by the State in the Response to Comments document. 
Additional information regarding responses to specific State comments
can be found in EPA’s Response to Comments document at   HYPERLINK
"http://www.epa.gov/pmdesignations/2006standards/tech.htm" 
http://www.epa.gov/pmdesignations/2006standards/tech.htm .

EPA Technical Analysis for Cincinnati, OH-KY-IN 

EPA reviewed the relevant information for the eight counties, including
a portion of one county in Indiana, partly or fully within the area
designated nonattainment for the 1997 standards as well as for
surrounding counties.  There are violating monitors in Hamilton and
Butler Counties in Ohio and in Kenton County in Kentucky.  While EPA
designated Lawrenceburg Township of Dearborn County as nonattainment for
the 1997 standards, Indiana recommended that this entire county be
designated as attainment.

EPA believes that Lawrenceburg Township of Dearborn County contributes
to violations elsewhere in the Cincinnati Combined Statistical Area. 
The county has high emissions relatively close to the locations of
violations and is commonly upwind on days with high concentrations.  In
addition, establishment of a nonattainment area for the 2006 standards
that matches the existing nonattainment area boundaries set for the 1997
standards will simplify planning by assuring that the corresponding
requirements for the two sets of air quality standards apply to the same
area.

The information supplied by Indiana indicates that the power plant in
Lawrenceburg Township is planning to install selective noncatalytic
reduction control equipment to reduce NOx emissions in 2010, and no
significant SO2 emission controls are expected in the near future.  EPA
is promulgating designations based on current air quality and current
emission levels, and EPA has concluded that the power plant in
Lawrenceburg Township contributes to the violations in the
Cincinnati-Middletown area.  Therefore, EPA is including Lawrenceburg
Township of Dearborn County in the Cincinnati-Middletown nonattainment
area.

EPA reviewed the relevant information for other counties within the
combined statistical area as well as counties adjacent to the combined
statistical area in order to determine the appropriate nonattainment
area.  Jefferson County was not considered as a possible candidate for
nonattainment in the Cincinnati area because it is considered part of
the Louisville area for purposes of nonattainment designations.  Other
Indiana counties in or near the combined statistical area and other
portions of Dearborn County have relatively low emissions, and no other
factor warranted inclusion of these other areas in the nonattainment
area.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

For this area, EPA previously established PM2.5 nonattainment boundaries
for the 1997 PM2.5 NAAQS that included eight full and partial counties,
with one being located in Indiana.  

In its December 17, 2007 letter, Indiana recommended that no Indiana
areas be designated as “nonattainment” for the 2006 24-hour PM2.5
standard based on air quality data from 2004-2006.  These data are from
Federal Reference Method (FRM) monitors located in the state.

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  

Based on EPA's technical analysis described below, EPA has designated a
partial county in Indiana as nonattainment for the 24-hour PM2.5
air-quality standard as part of the Cincinnati nonattainment area, based
upon currently available information.  These counties are listed in the
table below.

The following is a review of data for relevant factors for the Indiana
portion of the Cincinnati, Ohio-Kentucky-Indiana area. 

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Cincinnati area.  Counties that are part of
the Cincinnati nonattainment area for the 1997 PM2.5 NAAQS are shown in
boldface.  Counties are listed in descending order by CES.

Table 1.  PM2.5 24-hour Component Emissions, and CESs. 

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2	NOx	VOCs	NH3

Hamilton, OH	Yes	100	6,489	1,244	5,245	88,139	50,060	38,552	2,359

Clermont, OH	Yes	36	5,399	733	4,665	90,341	35,748	6,982	407

Butler, OH	Yes	24	2,269	563	1,706	10,636	16,661	12,734	1,105

Dearborn, IN	No	22	2,780	288	2,492	47,908	12,881	3,268	229

Jefferson, IN	No	7	1,265	168	1,097	75,319	25,214	2,272	341

Boone, KY	No	6	1,629	615	1,014	5,383	10,852	5,883	286

Adams, OH	No	6	5,970	494	5,476	126,316	33,822	1,918	837

Warren, OH	Yes	5	1,304	535	768	568	7,244	7,278	792

Kenton, KY	No	3	537	269	268	1,300	6,316	5,606	266

Campbell, KY	No	2	412	179	233	731	4,231	2,923	196



Dearborn County has similar emissions to Butler and Clermont Counties,
Ohio.  There is a power plant in Lawrenceburg Township which accounts
for most of Dearborn County’s emissions.  Jefferson County, Indiana
has a moderate CES in the Cincinnati area even though it has similar
emissions to Dearborn County.  Analysis showed that Jefferson County is
more a part of the Louisville area.

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Hamilton, OH	100	100	100	10.6

Clermont, OH	36	77	71	23.2

Butler, OH	24	90	64	19

Dearborn, IN	22	73	61	21.8

Jefferson, IN	7	30	25	55.6

Boone, KY	6	77	78	16.6

Adams, OH	6	32	21	62.6

Warren, OH	5	80	57	27.4

Kenton, KY	3	79	82	15.4

Campbell, KY	2	82	84	17.4



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Cincinnati area based on data
for the 2005-2007 period.  A monitor’s design value indicates whether
that monitor attains a specified air quality standard.  The 24-hour
PM2.5 standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met.

The 24-hour PM2.5 design values for counties in the Cincinnati area are
shown in Table 3.

	Table 3.  Air Quality Data

County	State

Recommended

Nonattainment?	Design Values 2004-2006

	Design Values 2005-2007



Hamilton, OH	Yes	40	41

Clermont, OH	Yes

34

Butler, OH	Yes	38	38

Dearborn, IN	No



Boone, KY	No



Warren, OH	Yes



Kenton, KY	No	35	36

Campbell, KY	No





In EPA Region 5, Hamilton and Butler Counties in Ohio show violations of
the 24-hour PM2.5 standard.  There is no monitoring data for Dearborn
County.  However, the absence of a violating monitor alone does not
eliminate counties from nonattainment status.  Each county has been
evaluated based on the weight of evidence of the nine factors and other
relevant information.

For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Cincinnati area occur about 86% in the
warm season and 14% in the cool season.  In the warm season, the average
chemical composition of the highest days is 82% sulfate, no nitrate, 17%
carbon, and 2% crustal.  In the cool season, the average chemical
composition of the highest days is 50% sulfate, 25% nitrate, 23% carbon,
and 2% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards. 

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/mi2)

Hamilton, OH	Yes	   828,487 	2007

Clermont, OH	Yes	190,329 	417

Butler, OH	Yes	   349,966 	745

Dearborn, IN	No	     48,930 	160

Boone, KY	No	   106,278 	414

Warren, OH	Yes	   196,793 	484

Kenton, KY	No	   153,314 	930

Campbell, KY	No	     87,048 	547



The population and population density of Dearborn County are both the
lowest of the area counties listed on Table 4.  Having a relatively low
population and population density suggests that designating only a
portion of Dearborn County as nonattainment may be warranted. 

Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Cincinnati area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.  

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties 	Percent

Commuting to any violating counties 	Number Commuting within statistical
area 	Percent

Commuting within statistical area 

Hamilton, OH	Yes	    8,132 	364,380 	92 	    391,410 	          98 

Butler, OH	Yes	    3,059 	143,800 	90 	    153,070 	          96 

Clermont, OH	Yes	    1,799 	45,070 	51 	      86,620 	          98 

Kenton, KY	No	    1,647 	51,980 	68 	      74,830 	          99 

Warren, OH	Yes	    1,692 	41,510 	54 	      62,590 	          82 

Boone, KY	No	    1,074 	17,300 	39 	      43,420 	          98 

Campbell, KY	No	    1,000 	21,460 	50 	      42,160 	          99 

Dearborn, IN	No	       708 	8,920 	40 	      20,700 	          92 



The listing of counties on Table 5 reflects a ranking based on the
number of people commuting within the Cincinnati area.  The listed
counties are all in the Cincinnati nonattainment area for the 1997 PM2.5
NAAQS.  

The VMT figure for Dearborn County is much lower than the other listed
counties, but 92% commuting within the statistical area suggests a tie
to the Cincinnati area.

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Cincinnati area, as
well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Cincinnati area.  Counties are
listed in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Growth and Percent Change.

County	Population (2005)	Population % change (2000-05)	2005 VMT

(106 mi)	VMT

% change

(1996-05)

Boone, KY	    106,278 	22 	     1,074 	          48 

Warren, OH	    196,793 	22 	     1,692 	          34 

Dearborn, IN	     48,930 	6 	        708 	          30 

Butler, OH	    349,966 	5 	     3,059 	          28 

Clermont, OH	    190,329 	7 	     1,799 	          16 

Campbell, KY	     87,048 	-2	     1,000 	            4 

Hamilton, OH	    828,487 	-2	     8,132 	            3 

Kenton, KY	    153,314 	1 	     1,647 	            3 



The low VMT of Dearborn County, Indiana is growing at a fair rate from
1996 to 2005.  Its low population is also growing, though not nearly as
fast as Boone County, Kentucky and Warren County, Ohio are growing.

 

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for the Cincinnati area is provided as Figure 2. 
Winds on high concentration days show a preference to come from the
Northeast or Southwest.  Dearborn County is in the western portion of
the Cincinnati area, so these data support a finding that Dearborn
County contributes to violations in Hamilton and Butler Counties, Ohio. 


 

Figure 2

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area.

The Cincinnati area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  Analysis of
chemical composition data in these areas indicates that the same
components that make up most of the PM2.5 mass in the area on an annual
average basis such as sulfate and direct PM2.5 carbon in many eastern
areas also are key contributors to the PM2.5 mass on days exceeding the
24-hour PM2.5 standard.  These data indicate that in many cities, the
same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

Most areas that were originally designated nonattainment for the PM2.5
standards still have not attained the air quality standards.  Thus, EPA
has generally concluded that counties that were designated as having
emissions sources contributing to fine particle concentrations which
continue to exceed the 1997 standards (all areas violated the annual
standard, two also violated the previous 24-hour standard) also
contribute to fine particle concentrations on the highest days.  For
this reason, EPA believes that for most existing nonattainment areas,
the nonattainment area for the 2006 24-hour standard should be the same.
 Consideration also should be given to existing boundaries and
organizations as they may facilitate air quality planning and the
implementation of control measures to attain the standard.  Areas
already designated as nonattainment represent important boundaries for
state air quality planning.

The Ohio-Kentucky-Indiana Regional Council of Governments (OKI) is the
Metropolitan Planning Organization (MPO) for Butler, Warren, Clermont,
and Hamilton Counties in Ohio; Campbell, Kenton, and Boone Counties in
Kentucky; and Dearborn County, Indiana.  OKI webpage:   HYPERLINK
"http://www.oki.org/"  http://www.oki.org/ .

The Cincinnati ozone nonattainment area consists of the following
counties: in Ohio- Butler, Clermont, Clinton, Hamilton, and Warren; in
Indiana- Lawrenceburg Township in Dearborn; in Kentucky- Boone, Kenton,
and Campbell.

The inclusion of Dearborn County in these particular jurisdictions is
not a significant factor in EPA’s decision to designate part of the
county as nonattainment, but does suggest that its inclusion in the
Cincinnati nonattainment area makes sense from an air quality management
perspective.

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Cincinnati area before 2005 on stationary, mobile, and area
sources.  Data are presented for PM2.5 components that are directly
emitted, carbonaceous PM2.5 and crustal PM2.5, and for pollutants which
react in the atmosphere to form fine particles such as SO2, NOx, VOC,
and ammonia.  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational. 

The information supplied by Indiana indicates that the power plant in
Lawrenceburg Township is planning to install selective noncatalytic
reduction control equipment to reduce NOx emissions in 2010, and no
significant SO2 emission controls are expected in the near future. 
Thus, current emissions from this plant remain relatively high.

EPA Technical Analysis for Evansville, IN 

EPA reviewed the relevant information for the six counties partly or
fully within the area designated nonattainment for the 1997 PM2.5
standards in Evansville, as well as for surrounding counties.  There are
monitors in Vanderburgh and Dubois Counties showing violations of the
2006 PM2.5 standards, in particular the 24-hour standard.  In 2005, EPA
designated a nonattainment area for the 1997 standards that included the
entirety of Dubois, Vanderburgh, and Warrick Counties and a township in
each of Gibson, Pike and Spencer Counties.  Indiana has requested
redesignation of this area with respect to the 1997 standards. 
Nevertheless, EPA’s designations in 2005 reflect EPA’s determination
at that time that those six counties contributed to the violations of
the annual standard that were then being observed in Vanderburgh and
Dubois Counties.  EPA finds in general that violations of the 24-hour
PM2.5 standard reflect the same combination of local scale, metropolitan
scale, and regional scale contributions as contribute to violations of
the annual standard, and EPA believes in particular that this
combination of scales of contribution are responsible for the violations
of the 24-hour standard in the Evansville area.

Indiana submitted information to suggest that a number of observations
of high concentrations, most notably in Dubois County, would not have
been high but for exceptional events.  The review of this information is
provided separately.  In some cases, EPA is concurring with Indiana’s
claim that high concentrations would not have occurred but for an
exceptional event, and in other cases, EPA is not concurring with
Indiana’s claim.  In the Evansville area, the net result of EPA’s
findings is a conclusion that Vanderburgh County is violating the
24-hour standard for the 2005 to 2007 period and Dubois County is
attaining the standard for the same period.  

EPA has concluded that the Evansville nonattainment area for the 2006
standards should include Vanderburgh County, Warrick County, Montgomery
Township in Gibson County, Washington Township in Pike County, and Ohio
Township in Spencer County.  Vanderburgh County is recording a
violation, is contributing to its violation, and was recommended as
nonattainment by the State.  Warrick County has relatively high
emissions that are commonly upwind of the violating monitors and thus is
contributing to violations in the Evansville area.  Warrick County is
also part of the Evansville Metropolitan Statistical Area, in part
reflecting the substantial commuting between Warrick and Vanderburgh
Counties.

Gibson, Pike, and Spencer Counties all have substantial emissions that
are commonly upwind and contribute to the violations in Vanderburgh
County.  These emissions in each case predominantly arise from power
plants located in the townships named above.  As part of its evaluation
of final designations, EPA undertook a careful review of the degree to
which these power plants are controlled, the enforceability of these
controls (i.e., whether EPA can be assured that the controls will remain
in place), and the quantity of emissions that remain after these
controls.  

In Gibson County, Gibson Station has in place some longstanding SO2
emission controls installed to address acid rain program requirements
and some more recently installed SO2 emission controls, as well as NOx
emission controls installed to address the NOx budget trading program
that operated during the ozone season.  Nevertheless, even with these
controls, emissions from this facility remain sufficiently high to be
judged still to be contributing to the violations.  Furthermore, given
the uncertain status of the Clean Air Interstate Rule (CAIR) as a result
of an adverse opinion by the D.C. Circuit Court of Appeals, the
operation of the recent SO2 controls and wintertime operation of the NOx
controls is in doubt.

In Pike County, Petersburg Station has longstanding SO2 emission
controls and has installed NOx emission controls on two of the four
units.  In the absence of CAIR, the owner would not be required to
operate the NOx emission controls in the winter.  Even with these
controls, emissions from this facility remain sufficiently high to be
judged still to be contributing to the violations.  In addition, no
supplemental emission controls have been installed on Frank E. Ratts
Station.  

In Spencer County, Rockport Station has not installed supplemental
emission controls for either SO2 or NOx, and emissions from this
facility remain sufficiently high to be judged still to be contributing
to the violations.  

The Evansville nonattainment area as defined for the 1997 standards
included Dubois County.  At the time EPA promulgated those designations,
Dubois County was violating the applicable standards.  Dubois County was
not and is not part of the Evansville Metropolitan Statistical Area, few
people commute from Dubois County into the Evansville area, and EPA did
not identify Dubois County as contributing to violations in the
Evansville area.  Nevertheless, EPA recognized that the violations in
Dubois and Vanderburgh County had common origins, so that it was most
appropriate to define a single nonattainment area creating a single
planning area in which the two counties’ violations that sources in
the area contribute to would be addressed jointly.

However, as noted above, EPA finds that Dubois County is now attaining
the standards based on 2005 to 2007 data (for planning purposes, based
on exclusion of values that would have been significantly lower but for
exceptional events).  EPA also finds that Dubois County is not
contributing to violations in Vanderburgh County.  Therefore, EPA finds
that consideration of relevant factors suggests a different
nonattainment area for the 2006 standards than was identified for the
1997 standards, specifically that Dubois County should be excluded from
the Evansville nonattainment area for the 2006 standards.  EPA’s
rationale for concurring on the values caused by exceptional events is
explained in the attachment to this TSD.

Violations are also being recorded in Knox County, which is in the
Vincennes Micropolitan Statistical Area, an area that adjoins the
Evansville Metropolitan Statistical Area.  As is true in many areas in
the Eastern United States, emissions in the Evansville area have some
impact on the adjoining Vincennes area.  Clean Air Act Section 107
instructs EPA to designate as nonattainment any area “that contributes
to ambient air quality in a nearby area that does not meet” the
standard.  While the transport of fine particulate matter in the Eastern
United States is such that sources even 1000 kilometers away can
influence air quality, suggesting the possibility of defining a single
nonattainment area including large parts of the Eastern United States,
Section 107 instructs EPA to define multiple separate nonattainment
areas that are limited to particular areas with violations and the
nearby source areas that contribute to those violations.  In
implementing this provision, EPA generally defines separate metropolitan
areas as separate nonattainment areas, even if as here the metropolitan
areas are contiguous.  That is, in judging what areas influencing air
quality at a violating monitor can be considered to be “nearby,” EPA
commonly views separate metropolitan areas as insufficiently nearby to
include in the same nonattainment area.

The Evansville area as defined for the 1997 standards reflects an
exception to this general approach, with the inclusion of portions of
the Jasper micropolitan statistical area (which includes Dubois and Pike
Counties) along with portions of the Evansville metropolitan statistical
area in a combined Evansville nonattainment area.  However, in 2005,
when EPA defined the Evansville nonattainment area, the Office of
Management and Budget had not defined any micropolitan statistical
areas, and Dubois and Pike Counties were not included in any
metropolitan area and were implicitly defined as rural.  Under those
circumstances, EPA concluded that the violation in Dubois County,
reflecting substantial contributions from various parts of the
Evansville area, was best addressed jointly with the Evansville area. 
EPA believes that Vincennes/Knox County presents a different situation,
and EPA is designating a separate Vincennes nonattainment area in light
of the separate micropolitan statistical area which now exists for
Vincennes.

EPA reviewed the relevant information for other counties within the
Evansville metropolitan statistical area as well as other counties
adjacent to the combined statistical area in order to determine the
appropriate nonattainment area boundary.  Other Indiana counties in or
near the combined statistical area have relatively low emissions, and no
other factor warranted inclusion of any of the counties in the
nonattainment area.  Similarly, portions of Gibson, Pike, and Spencer
Counties other than the townships identified above also have relatively
low emissions and do not warrant including in the nonattainment area. 
Consequently, EPA is including only partial counties representing the
townships that contain the large power plants.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

For this area, EPA previously established PM2.5 nonattainment boundaries
for the 1997 PM2.5 NAAQS that included six full and partial counties,
with all being located in Indiana.  

In its May 30, 2008 letter, Indiana recommended that one county be
designated as “nonattainment” for the 2006 24-hour PM2.5 standard
based on air quality data from 2005-2007.  These data are from Federal
Reference Method (FRM) monitors located in the state. 

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  

Based on EPA's technical analysis described below, EPA has designated
five full or partial Indiana counties as nonattainment for the 24-hour
PM2.5 air-quality standard as part of the Evansville nonattainment area,
based upon currently available information.  

The following is a review of data for relevant factors for the
Evansville, Indiana area.

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Evansville area.  Counties that are part of
the Evansville nonattainment area for the 1997 PM2.5 NAAQS are shown in
boldface.  Counties are listed in descending order by CES.

Table 1.  PM2.5 Related Emissions and Contributing Emissions Score

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx

	VOCs

	NH3

Warrick, IN	No	100	8,412	540	7,872	92,222	18,291	3,856	735

Gibson, IN	No	76	6,642	420	6,223	154,782	32,655	3,679	1,921

Spencer, IN	No	73	1,568	201	1,367	67,705	24,104	2,223	1,297

Vanderburgh, IN	Yes	61	1,558	308	1,250	2,029	7,048	8,405	469

Pike, IN	No	53	2,412	163	2,249	52,836	18,990	1,206	487

Henderson, KY	No	33	1,202	267	936	8,612	5,525	3,068	670

Posey, IN	No	19	1,602	193	1,409	14,531	12,161	3,443	1,343

Dubois, IN	No	15	1,204	228	977	2,131	3,438	5,792	3,917

Daviess, KY	No	15	1,413	367	1,046	7,605	11,880	6,322	1,547



The emissions from Gibson, Spencer, Pike, Vanderburgh, and Warrick
Counties are all relatively high, which indicates that based on this
factor these counties should be included in the nonattainment area.  The
emissions from Dubois and Posey Counties in Indiana and Daviess and
Henderson Counties in Kentucky are modest.

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Warrick	100	93	100	30.5

Gibson	76	84	53	37.5

Spencer	73	81	87	26.7

Vanderburgh	61	100	96	45.7

Pike	53	72	53	19.8

Henderson	33	93	93	54.3

Posey	19	89	52	59.1

Dubois	15	61	49	11.7

Daviess	15	79	85	44.1



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Evansville area based on data
for the 2005-2007 period.  A monitor’s design value indicates whether
that monitor attains a specified air quality standard.  The 24-hour
PM2.5 standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met. 

The 24-hour PM2.5 design values for counties in the Evansville area are
shown in Table 3.

	Table 3.  Air Quality Data

County	State 

Recommended

 Nonattainment?	Design Values

2004-2006

	Design Values

2005-2007

Warrick, IN	No	0	0

Gibson, IN	No	0	0

Spencer, IN	No	31	33

Vanderburgh, IN	Yes	34	36

Pike, IN	No	0	0

Dubois, IN	No	34	35

Henderson, KY	No	30	32

Posey, IN	No	0	0

Daviess, KY	No

34



Vanderburgh Counties has a design values that exceed the air quality
standards based on 2005-2007 data.  Therefore, it must be designated
nonattainment.  Dubois County had a design value above the 2006
standards, so it was previously designated as nonattainment.  The air
quality in Dubois County now meets the standards (for planning purposes)
after consideration of exceptional events as described in the
attachment.  The absence of a violating monitor alone is not sufficient
reason to eliminate counties as candidates for nonattainment status. 
EPA must also evaluate whether Dubois County contributes to violations
in Vanderburgh County.

For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Evansville area occur about 94% in the
warm season and 6% in the cool season.  In the warm season, the average
chemical composition of the highest days is 83% sulfate, no nitrate, 16%
carbon, and 1% crustal.  In the cool season, the average chemical
composition of the highest days is 60% sulfate, 32% nitrate, 7% carbon,
and 1% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards.  Vanderburgh County, Indiana with the City of
Evansville has the largest population in the area indicating that for
this factor it should be included in the nonattainment area.  The other
area counties all have modest populations.

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/sq mi)

Warrick, IN	No	     56,435 	144

Gibson, IN	No	     33,347 	67

Spencer, IN	No	     20,476 	51

Vanderburgh, IN	Yes	   172,774 	734

Pike, IN	No	     12,766 	37

Dubois, IN	No	     40,922 	94

Henderson, KY	No	     45,563 	98

Posey, IN	No	     26,834 	64

Daviess, KY	No	     92,837 	195



Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Evansville area, the percent of total
commuters in each county who commute to other counties within the
statistical area, as well as the total Vehicle Miles Traveled (VMT) for
each county in millions of miles (see Table 5).  A county with numerous
commuters is generally an integral part of an urban area and is likely
contributing to fine particle concentrations in the area.  

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties 	Percent

Commuting to any violating counties 	Number Commuting within/to
statistical area 	Percent

Commuting within/to statistical area 

Vanderburgh, IN	Yes	    1,452 	75,290 	90 	      81,640 	          98 

Warrick, IN	No	       797 	14,890 	56 	      24,950 	          95 

Henderson, KY	No	       508 	3,570 	17 	      19,430 	          94 

Gibson, IN	No	       469 	4,330 	28 	      13,880 	          90 

Posey, IN	No	       553 	5,600 	44 	      12,520 	          98 

Spencer, IN	No	       430 	3,020 	31 	        2,200 	          22 

Daviess, KY	No	       782 	660 	2 	        1,740 	            4 

Pike, IN	No	       169 	2,310 	41 	           920 	          16 

Dubois, IN	No	       539 	19,030 	93 	           450 	            2 



The listing of counties on Table 4 reflects a ranking based on the
number of people commuting to other counties.  The counties that are in
the nonattainment area for the 1997 PM2.5 NAAQS are shown in boldface. 
Vanderburgh County stands out with its VMT being well above the other
area counties indicating that for this factor it should be included in
the nonattainment area.  Daviess County, Kentucky and Dubois County,
Indiana show limited commuting into the MSA.  Note that the Dubois
County figures were calculated when Dubois County was considered a
violating county.  So, the commuting within or to violating counties
figures for Dubois County are erroneously high.  Indiana provided 2005
commuting data showing that 27,867 people lived and worked in Dubois
County and just 198 people commuted from Dubois to Vanderburgh County. 
In fact, just 6.5% of Dubois County residents commute outside the
county.

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
atftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002
_mobile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in the Evansville
area, as well as patterns of population and VMT growth.  A county with
rapid population or VMT growth is generally an integral part of an urban
area and likely to be contributing to fine particle concentrations in
the area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Evansville area.  Counties are
listed in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Values and Percent Change.

County	Population (2005)	Population % change (2000-2005)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Posey, IN	     26,834 	-1	        553 	          22 

Dubois, IN	     40,922 	3 	        539 	          21 

Spencer, IN	     20,476 	0 	        430 	          20 

Gibson, IN	     33,347 	2 	        469 	          19 

Warrick, IN	     56,435 	7 	        797 	            9 

Henderson, KY	     45,563 	2 	        508 	            1 

Pike, IN	     12,766 	0 	        169 	            0 

Daviess, KY	     92,837 	1 	        782 	            0

Vanderburgh, IN	    172,774 	1 	     1,452 	           -7 



Dubois, Gibson, Posey, and Spencer Counties all have VMT growth of
around 20% though their annual VMT remains modest.  The VMT growth is
lower in the other counties.  The population growth is limited across
the area, so that this factor was not significant in determining the
nonattainment area boundary.

Factor 6:  Meteorology (weather/transport patterns) 

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

 

Figure 2.

As shown in the pollution rose in Figure 2, on high PM2.5 days
prevailing surface winds come from a variety of directions.  So, it was
appropriate to consider counties in all directions from the violation.

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the Evansville area.

The Evansville area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries (e.g., existing PM2.5 areas) 

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  Analysis of
chemical composition data in these areas indicates that the same
components that make up most of the PM2.5 mass in the area on an annual
average basis such as sulfate and direct PM2.5 carbon in many eastern
areas also are key contributors to the PM2.5 mass on days exceeding the
24-hour PM2.5 standard.  These data indicate that in many cities, the
same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

Most areas that were originally designated nonattainment for the PM2.5
standards still have not attained the air quality standards.  Thus, EPA
has generally concluded that counties that were designated as having
emissions sources contributing to fine particle concentrations which
continue to exceed the 1997 standards (all areas violated the annual
standard, two also violated the previous 24-hour standard) also
contribute to fine particle concentrations on the highest days.  For
this reason, EPA believes that for most existing nonattainment areas,
the nonattainment area for the 2006 24-hour standard should be the same.
 Consideration also should be given to existing boundaries and
organizations as they may facilitate air quality planning and the
implementation of control measures to attain the standard.  Areas
already designated as nonattainment represent important boundaries for
state air quality planning.

The MPO for Vanderburgh and Warrick Counties is the Evansville Urban
Transportation Study.

Vanderburgh and Warrick Counties are in the Evansville ozone maintenance
area.  All other area counties were designated as
attainment/unclassified for 8-hour ozone.

In addition to Vanderburgh and Warrick Counties, Dubois and Pike
Counties are also included in the PM2.5 Evansville nonattainment area
designated under the 1997 standards.  These counties are not in the
Evansville Metropolitan Statistical Area.  Dubois County was included in
the 1997 standards Evansville area because it was violating the
standards, although it is currently attaining the 2006 standards
excluding the influence of  exceptional events.  Pike County was
included due to its contributing emissions.  Dubois and Pike Counties
are now in a separate area, the Jasper Micropolitan Area.  The fact that
Dubois County is in a separate area from the Evansville metropolitan
area lends support to the view that Dubois County sources, especially
commuting vehicles, do not contribute to violations in Vanderburgh
County.  Pike County was in the 1997 standards Evansville area and it is
adjacent to Evansville Metropolitan Statistical Area, so it belongs with
the Evansville nonattainment area.  

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Evansville area before 2005 on stationary, mobile, and area
sources.  Data are presented for PM2.5 components that are directly
emitted (carbonaceous PM2.5 and crustal PM2.5) and for pollutants which
react in the atmosphere to form fine particles (e.g. SO2, NOx, VOC, and
ammonia).  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational. 

Indiana provided information on the controls in place at power plants in
Gibson, Pike, Posey, Spencer, and Warrick Counties.  No major reductions
have occurred since 2005, so the emissions data used to analyze the
Evansville area were appropriate.  EPA concluded based on that data that
the five counties or partial counties of Vanderburgh County, Warrick
County, Montgomery Township in Gibson County, Washington Township in
Pike County, and Ohio Township in Spencer County should be included in
the Evansville 24 hour PM2.5 nonattainment area.

EPA Technical Analysis for Indianapolis, IN 

EPA reviewed the relevant information for the five counties in the area
designated nonattainment for the 1997 standards as well as for
surrounding counties.  There are violating monitors in Marion County. 
While EPA designated Hamilton, Hendricks, Johnson, Marion, and Morgan
Counties as nonattainment with respect to the 1997 standards, Indiana
recommended that only Marion County be designated nonattainment.

EPA believes that all of the areas designated nonattainment for the 1997
standards also contribute to violations of the 2006 standards.  While
Marion County likely makes the greatest contribution to violations
within Marion County, the other four counties designated nonattainment
for the 1997 all have substantial emissions, are commonly upwind of the
violating monitors on high concentration days, and are relatively nearby
to the violating monitor.  

EPA reviewed the relevant information for other counties within the
combined statistical area as well as counties adjacent to the combined
statistical area in order to determine the appropriate nonattainment
area.  Other Indiana counties in or near the combined statistical area
have relatively low emissions, and no other factor warranted inclusion
of the counties in the nonattainment area.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

For this area, EPA previously established PM2.5 nonattainment boundaries
for the 1997 PM2.5 NAAQS that included five counties, with all being
located in Indiana. 

In it December 17, 2007 letter, Indiana recommended that one county be
designated as “nonattainment” for the 2006 24-hour PM2.5 standard
based on air quality data from 2004-2006.  These data are from Federal
Reference Method (FRM) monitors located in the state.

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  Indiana provided
information on pollution controls recently added to a Marion County
power plant.

Based on EPA's technical analysis described below, EPA has designated
the same counties as previously designated for PM2.5 as nonattainment
for the 24-hour PM2.5 air-quality standard as part of the Indianapolis
nonattainment area, based upon currently available information.  These
counties are listed in the table below.

The following is a review of data for relevant factors for the
Indianapolis nonattainment area. 

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes:   “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Indianapolis area.  Counties that are part
of the Indianapolis nonattainment area for the 1997 PM2.5 NAAQS are
shown in boldface.  Counties are listed in descending order by CES.

Table 1.  PM2.5 Related Emissions and Contributing Emissions Score

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx

	VOCs

	NH3



Marion, IN	Yes	100	6,606	1,245	5,361	60,898	37,673	37,017	1,876

Morgan, IN	No	10	1,617	240	1,376	19,016	6,643	3,881	413

Hamilton, IN	No	4	1,801	432	1,369	1,226	7,988	9,210	754

Hendricks, IN	No	4	1,342	319	1,022	602	5,799	4,898	685

Johnson, IN	No	4	1,108	221	887	944	4,704	6,593	1,276

Shelby, IN	No	3	1,346	238	1,107	768	4,511	3,571	964

Hancock, IN	No	2	948	169	777	430	3,144	3,308	763

Boone, IN	No	1	1,041	189	852	401	3,507	3,378	1,353



Marion County stands out with its emission figures being well above the
other area counties.  The sulfur dioxide emissions in Morgan County push
its CES above the remaining area counties.  The other counties all have
similar emissions.  Marion County is a good candidate for nonattainment
based on emissions data.  Hamilton, Hendricks, Johnson, Morgan, and
Shelby Counties are possible candidates for nonattainment.  Boone and
Hancock Counties have low emissions which makes the counties weak
nonattainment candidates based on this factor. 

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Marion	100	100	97	11.3

Morgan	10	83	86	26.8

Hamilton	4	70	43	20.8

Hendricks	4	80	70	19.6

Johnson	4	89	100	20.1

Shelby	3	73	87	25.7

Hancock	2	81	74	19.6

Boone	1	59	35	25.7



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Indianapolis area based on data
for the 2005-2007 period.  A monitor’s design value indicates whether
that monitor attains a specified air quality standard.  The 24-hour
PM2.5 standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met. 

The 24-hour PM2.5 design values for counties in the Indianapolis area
are shown in Table 3.  Marion County is the only area county with
monitoring data.  Marion County has a design value above the standard in
both 2004-2006 and 2005-2007.  However, the absence of a violating
monitor alone is not a sufficient reason to eliminate counties as
candidates for nonattainment status.  Each county has been evaluated
based on the weight of evidence of the nine factors and other relevant
information.

	Table 3.  Air Quality Data

County	State 

Recommended

 Nonattainment?	Design Values

2004-2006

	Design Values

2005-2007

Marion, IN	Yes	38	40

Morgan, IN	No	0	0

Hamilton, IN	No	0	0

Hendricks, IN	No	0	0

Johnson, IN	No	0	0

Shelby, IN	No	0	0

Hancock, IN	No	0	0

Boone, IN	No	0	0



For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Indianapolis area occur about 70% in the
warm season and 30% in the cool season.  In the warm season, the average
chemical composition of the highest days is 74% sulfate, no nitrate, 24%
carbon, and 2% crustal.  In the cool season, the average chemical
composition of the highest days is 55% sulfate, 25% nitrate, 18% carbon,
and 2% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards. 

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/sq mi)

Marion, IN	Yes	   861,760 	2140

Morgan, IN	No	     69,751 	171

Hamilton, IN	No	   240,732 	598

Hendricks, IN	No	   127,261 	312

Johnson, IN	No	   129,823 	404

Shelby, IN	No	     43,775 	106

Hancock, IN	No	     62,972 	205

Boone, IN	No	     51,918 	123



Marion County has the highest population in the area.  Hamilton,
Hendricks, and Johnson have the next largest populations.  The other
counties have much smaller populations.

Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Indianapolis area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.  

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties 	Percent

Commuting to any violating counties 	Number Commuting within statistical
area 	Percent

Commuting within statistical area 

Marion, IN	Yes	     7,913 	368,840 	87 	    417,860 	          99 

Hamilton, IN	No	     2,035 	43,360 	46 	      90,100 	          96 

Johnson, IN	No	     1,359 	28,610 	49 	      57,810 	          99 

Hendricks, IN	No	     1,373 	28,500 	54 	      52,030 	          98 

Morgan, IN	No	        932 	13,780 	42 	      31,680 	          96 

Hancock, IN	No	        813 	14,000 	50 	      27,440 	          98 

Boone, IN	No	        844 	8,970 	40 	      21,490 	          95 

Shelby, IN	No	        698 	5,560 	26 	      20,940 	          97 



The listing of counties on Table 5 reflects a ranking based on the
number of people commuting to other counties.  The counties that are in
the nonattainment area for the 1997 PM2.5 NAAQS are shown in boldface. 
Marion County stands out again in the area.  Its VMT is well higher that
the other Indianapolis area counties.  The commuting into the
statistical area figures suggests an integration of all the counties
into the Indianapolis area.  About half of workers commute into the
violating county, Marion, from the other area counties except for Shelby
County.  The commuting data for Hamilton, Hendricks, Johnson, and Morgan
Counties makes them good candidates to be included with Marion County in
the Indianapolis nonattainment area.  The number of commuters, fewer
than 10,000, from Boone and Shelby Counties makes these counties a
weaker case for being considered for a nonattainment designation under
this factor.  

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Indianapolis area,
as well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Indianapolis area.  Counties are
listed in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Growth and Percent Change.

County	Population (2005)	Population % change (2000-05)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Boone, IN	     51,918 	12 	        844 	          28 

Hamilton, IN	    240,732 	30 	     2,035 	          24 

Hancock, IN	     62,972 	13 	        813 	          23 

Shelby, IN	     43,775 	0 	        698 	          22 

Hendricks, IN	    127,261 	21 	     1,373 	          22 

Johnson, IN	    129,823 	12 	     1,359 	          11

Morgan, IN	     69,751 	4 	        932 	          10 

Marion, IN	    861,760 	0 	     7,913 	         -10



There is solid growth in VMT in the counties that ring the central
county, Marion.  Five of the counties have VMT growth that exceeds 20%. 
The other two counties, Johnson and Morgan, have seen VMT increase by
about 10% from 1996 to 2005.  Marion County has seen its VMT decrease
during this period.  The population growth appears sporadic with some
counties experiencing no growth, while other saw moderate growth, and
two counties experienced strong growth.  Hamilton County grew by 30%
while Hendricks County saw 21% growth.   The growth in counties
surrounding Marion County enhances the importance of having an
Indianapolis area nonattainment plan that addresses these outer
counties.

Factor 6:  Meteorology (weather/transport patterns) 

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for the Indianapolis area is provided in Figure 2. 
Winds on the highest concentration days in the warm season tend to come
from the southwest to southeast.  The wind was a variety of directions
on the highest cool season days and on days year round with low or
moderate concentrations.  It is appropriate to consider counties in all
directions from Marion County.

 

Figure 2

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the Indianapolis area. 

The Indianapolis area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries (e.g., existing PM2.5 areas) 

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  Analysis of
chemical composition data in these areas indicates that the same
components that make up most of the PM2.5 mass in the area on an annual
average basis such as sulfate and direct PM2.5 carbon in many eastern
areas also are key contributors to the PM2.5 mass on days exceeding the
24-hour PM2.5 standard.  These data indicate that in many cities, the
same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

EPA has generally concluded that counties that were designated as having
emissions sources contributing to fine particle concentrations which
exceeded the 1997 standards (all areas violated the annual standard, two
also violated the previous 24-hour standard) also contribute to fine
particle concentrations on the highest days.  For this reason, EPA
believes that for most existing nonattainment areas, the nonattainment
area for the 2006 24-hour standard should be the same.  Consideration
also should be given to existing boundaries and organizations as they
may facilitate air quality planning and the implementation of control
measures to attain the standard.  Areas already designated as
nonattainment represent important boundaries for state air quality
planning.

The Indianapolis Metropolitan Planning Organization (MPO) serves Boone,
Hamilton, Hancock, Hendricks, Johnson, Marion, Morgan, and Shelby
Counties.

The Indianapolis ozone maintenance area is composed of Boone, Hamilton,
Hancock, Hendricks, Johnson, Madison, Marion, Morgan, and Shelby
Counties in Indiana. 

The Indianapolis nonattainment area is identical to the nonattainment
area designated under the 1997 PM2.5 standard.  The nonattainment area
consists of Hamilton, Hendricks, Johnson, Marion, and Morgan Counties.

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Indianapolis area before 2005 on stationary, mobile, and area
sources.  Data are presented for PM2.5 components that are directly
emitted, carbonaceous PM2.5 and crustal PM2.5, and for pollutants which
react in the atmosphere to form fine particles such as SO2, NOx, VOC,
and ammonia.  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational.

Indiana informed EPA of pollution controls recently added to a Marion
County power plant.  Emission reductions should help Marion County air
quality.  Still, the design value for Marion County is above the
standards.  Changes in this plant’s emissions, regardless of
enforceability, do not alter EPA’s view agreeing with the state that
Marion County contributes to its own violations.

Note: EPA has provided a thorough response to each of the specific
comments raised by the State in the Response to Comments document. 
Additional information regarding responses to specific State comments
can be found in EPA’s Response to Comments document at   HYPERLINK
"http://www.epa.gov/pmdesignations/2006standards/tech.htm" 
http://www.epa.gov/pmdesignations/2006standards/tech.htm .

EPA Technical Analysis for Lafayette-Frankfort, IN 

The Lafayette Metropolitan Statistical Area consists of Benton, Carroll,
and Tippecanoe Counties.  EPA reviewed the relevant information for
these counties as well as for surrounding counties.  There is a
violating monitor in Tippecanoe County.  These counties were designated
as attaining the 1997 standards.  Indiana recommended that the Lafayette
nonattainment area include only Tippecanoe County.

EPA agrees with Indiana’s recommendation.  Tippecanoe County violates
the standard and contributes to its own violations.  The other counties
in and around the metropolitan area have relatively low emissions, and
no other factor warranted inclusion of the counties in the nonattainment
area.  These counties are not considered to contribute to the violation
in Tippecanoe County after EPA analyzed the nine factors.  

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

In April 2008, EPA also notified Indiana that a monitor in the Lafayette
area was violating based on 2005-2007 data.  Indiana provided EPA with a
recommendation for this area in May 2008.  Indiana recommended one
county be designated as “nonattainment” for the 2006 24-hour PM2.5
standard based on 2005-2007 air quality data.  These data are from
Federal Reference Method (FRM) monitors located in the state.

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  Indiana did not provide
additional information on large sources in the Lafayette area.

Based on EPA's technical analysis described below, EPA has designated
one county in Indiana as nonattainment for the 24-hour PM2.5 air-quality
standard as the Lafayette nonattainment area, based upon currently
available information.  The county is listed in the table below.

The following is a review of data for relevant factors for the
Lafayette, Indiana area.

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Lafayette, Indiana area.  Counties are
listed in descending order by CES.

Table 1.  PM2.5 24-hour Component Emissions, and CESs 

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx

	VOCs

	NH3

Tippecanoe, IN	Yes	100	2,341	425	1,917	8,286	8,566	9,370	1,492

Jasper, IN	No	26	2,641	280	2,360	40,723	20,104	3,367	2,929

Montgomery, IN	No	18	1,306	252	1,052	1,287	3,656	3,626	1,534

Vermilion, IL	No	15	2,278	358	1,920	12,462	6,427	7,751	1,694

Clinton, IN	No	10	1,044	130	914	743	2,334	2,776	2,162

Carroll, IN	No	6	894	112	782	293	1,391	2,016	2,654

Benton, IN	No	3	828	88	740	119	827	1,203	1,203



Tippecanoe County has the highest CES, well ahead of the other counties
in the area.  Jasper County has the next highest score, a moderate 26,
but it is not adjacent to Tippecanoe County.  Jasper County is adjacent
to Lake and Porter Counties of the Chicago nonattainment area.  The
other counties have even lower emissions.  Tippecanoe County is the only
nonattainment candidate in the area from the emissions factor.

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Tippecanoe, IN	100	100	93	12.6

Jasper, IN	26	55	16	44.4

Montgomery, IN	18	89	100	24.1

Vermilion, IL	15	64	36	46.6

Clinton, IN	10	78	91	23.1

Carroll, IN	6	82	66	21.6

Benton, IN	3	83	48	26.6



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Lafayette area based on data for
the 2005-2007 period.  A monitor’s design value indicates whether that
monitor attains a specified air quality standard.  The 24-hour PM2.5
standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met.

The 24-hour PM2.5 design values for counties in the Lafayette, Indiana
area are shown in Table 3.

	Table 3.  Air Quality Data

County	State 

Recommended

 Nonattainment?	Design Values

2004-2006	Design Values

2005-2007

Tippecanoe, IN	Yes	34	37

Clinton, IN	No	0	0

Carroll, IN	No	0	0

Benton, IN	No	0	0

Jasper, IN	No	0	0

Montgomery, IN	No	0	0

Vermilion, IL	No	0	0



Tippecanoe County is the only county with a violating design value.  Its
2005-2007 design value exceeds the air quality standards.  The
surrounding counties do not have fine particulate monitoring data. 
However, the absence of a violating monitor alone is not a sufficient
reason to eliminate counties as candidates for nonattainment status. 
Each county has been evaluated based on the weight of evidence of the
nine factors and other relevant information.

For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Lafayette area occur about 75% in the
warm season and 25% in the cool season.  In the warm season, the average
chemical composition of the highest days is 72% sulfate, no nitrate, 24%
carbon, and 3% crustal.  In the cool season, the average chemical
composition of the highest days is 34% sulfate, 34% nitrate, 29% carbon,
and 3% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards.  The population and population density of Tippecanoe
County are much higher that any of the other counties in the area.

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/mi2)

Tippecanoe, IN	Yes	    154,024 	307

Clinton, IN	No	     34,073 	84

Carroll, IN	No	     20,446 	55

Benton, IN	No	       9,023 	22

Jasper, IN	No	     31,761 	57

Montgomery, IN	No	     38,189 	76

Vermilion, IL	No	     82,178 	91



Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Lafayette area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties	Percent

Commuting to any violating counties 	Number Commuting within/to
statistical area 	Percent

Commuting within/to statistical area 

Tippecanoe, IN	Yes	    1,332 	67,730 	93 	      69,120 	          95 

Clinton, IN	No	       526 	2,750 	18 	      12,380 	          83 

Carroll, IN	No	       272 	2,500 	26 	        7,410 	          76 

Benton, IN	No	       146 	1,650 	36 	        3,970 	          87 

Montgomery, IN	No	       751 	1,250 	7 	        1,330 	            7 

Jasper, IN	No	       757 	280 	2 	           310 	            2 

Vermilion, IL	No	       838 	50 	0 	            70 	            0 



The listing of counties on Table 5 reflects a ranking based on the
number of people commuting to other counties.  Tippecanoe County has a
much higher VMT that the other area counties do.  The commuting into any
violating county data suggests that not many people commute from Carroll
and Clinton Counties into Tippecanoe County.  When compared with
commuting into the statistical area figures, no strong connection
between these counties is suggested.  Benton, Carroll, Clinton, and
Tippecanoe Counties are all in the Lafayette statistical area. 
Tippecanoe County is the strongest candidate for nonattainment
considering this factor.  Benton, Carroll, and Clinton Counties are
weaker nonattainment candidates.

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Lafayette area, as
well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Lafayette, Indiana area.  Counties
are listed in descending order based on VMT growth between 1996 and
2005.

Table 6.  Population and VMT Growth and Percent Change.

Location	Population (2005)	Population % change (2000-2005)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Montgomery, IN	     38,189 	2 	        751 	          25 

Clinton, IN	     34,073 	0 	        526 	          24 

Jasper, IN	     31,761 	5 	        757 	          20 

Carroll, IN	     20,446 	1 	        272 	          19 

Vermilion, IL	     82,178 	-2	        838 	          17 

Benton, IN	       9,023 	-4	        146 	          15 

Tippecanoe, IN	    154,024 	3 	     1,332 	            6 



The VMT growth for Tippecanoe County is low.  It is higher in other area
counties, but the VMT remains well below Tippecanoe County’s level. 
Population change is low for all area counties.  The growth rates are
not expected to yield significant changes in the distribution of
population in the area, so this factor did not significantly influence
the decision-making process.

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for the Lafayette area is provided as Figure 2. 
Winds on high concentration days show a slight preference to come from
the South to Southeast, but the winds come from a variety of directions.
 So, it is appropriate to consider counties in all directions from the
violations.

 Figure 2

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area.

The Lafayette area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  However, this area
was designated attainment for the 1997 standards, so nonattainment area
boundaries for the 1997 standards were not a factor in determining this
area’s boundaries.

The metropolitan planning organization for the Lafayette area is the
Tippecanoe County Area Plan Commission (TCAPC).  

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Lafayette area before 2005 on stationary, mobile, and area
sources.  Data are presented for PM2.5 components that are directly
emitted, carbonaceous PM2.5 and crustal PM2.5, and for pollutants which
react in the atmosphere to form fine particles such as SO2, NOx, VOC,
and ammonia.  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational. 

Indiana did not provide any additional information on power plants or
other large sources in the Lafayette area.

Note: EPA has provided a thorough response to each of the specific
comments raised by the State in the Response to Comments document. 
Additional information regarding responses to specific State comments
can be found in EPA’s Response to Comments document at   HYPERLINK
"http://www.epa.gov/pmdesignations/2006standards/tech.htm" 
http://www.epa.gov/pmdesignations/2006standards/tech.htm .

EPA Technical Analysis for Louisville, KY-IN

EPA reviewed the relevant information for the five counties, including
three counties in Indiana, partly or fully within the area in Louisville
designated nonattainment for the 1997 PM 2.5 standards as well as for
surrounding counties.  There are violating monitors in Jefferson County,
Kentucky, and Clark County, Indiana.  While EPA designated Clark, Floyd,
and Madison Township of Jefferson County as part of the Louisville
nonattainment area with respect to the 1997 standards, Indiana
recommended that no portion of this area be designated nonattainment for
the 24 hour standard.

Indiana submitted information to indicate that some occurrences of high
concentration in Clark County should be attributed to exceptional
events.  EPA has evaluated this information, and is providing
documentation of its evaluation in a separate attachment to this TSD. 
While EPA concurs with some of these attributions, EPA nevertheless
concludes that the area is violating the 2006 standards based on
remaining exceedances.

EPA believes that all of the areas designated as nonattainment under the
1997 standards also contribute to violations of the 2006 standards, as
part of a single Louisville nonattainment area.  Given the range of
distance scales over which PM2.5 forms and transports, it is clear that
the violations in Jefferson County, Kentucky and Clark County, Indiana
are interrelated and must be addressed in a combined planning effort
that fully addresses the interrelationships.  Floyd County has
relatively high emissions as well as substantial population, a
significant fraction of which commutes into counties with violations. 
Emissions in Madison Township of Jefferson County, Indiana are also
relatively high, and the wind blows with sufficient frequency on high
concentration days from Jefferson County, Indiana toward the violating
monitors for these emissions to be judged to contribute to those
violations.  EPA found that Jefferson County, Indiana has a modest
population and it shows limited commuting to the Louisville area.  The
meteorological data indicates that the wind has a slight tendency to
come from the Northeast, where Jefferson County, Indiana is located. 
Jefferson County, Indiana was designated as a partial county
nonattainment area under the 1997 standards.  EPA determined that the
factors indicate the emissions concentrated in one township of Jefferson
County, Indiana contribution to the Louisville area violations, so EPA
is designating a partial county nonattainment area just as it did under
the 1997 standards.      

Indiana submitted information on the status of controls of Clifty Creek
Station in Jefferson County, Indiana.  This information indicates that
flue gas desulfurization will be installed on all units at this facility
in 2010, selective catalytic reduction is in place on 5 of 6 units, and
this equipment will be operated on a full year basis in the future. 
However, this information also indicates that current emissions are
relatively high.  Since EPA is promulgating designations based on
current air quality and current emissions contributing to existing
violations as required by the Act, EPA concludes that Madison Township
(including Clifty Creek Station) has relatively high emissions that
contribute to violations of the air quality standard in the Louisville
area and must be included in the Louisville nonattainment area
notwithstanding the fact that additional controls are planned for this
facility at a future date.

EPA reviewed the relevant information for other counties within the
metropolitan statistical area as well as counties adjacent to the
combined statistical area in order to determine the appropriate
nonattainment area.  Other Indiana counties in or near the combined
statistical area have relatively low emissions, and no other factor
warranted inclusion of the counties in the nonattainment area.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the metropolitan area boundary. 

 

Figure 1

For this area, EPA previously established PM2.5 nonattainment boundaries
for the 1997 PM2.5 NAAQS that included five full and partial counties,
with three in Indiana and two in Kentucky.

In August 2008, EPA notified Indiana and Kentucky of its intended
designations.  In this letter, EPA also requested that if the State
wished to provide comments on EPA’s intended designation, it should do
so by October 20, 2008.  EPA stated that it would consider any
additional information (e.g., on power plants or partial county areas)
provided by the state in making final decisions on the designations.  

Based on EPA's technical analysis described below, EPA has designated
three full or partial counties in Indiana and two Kentucky counties as
nonattainment for the 24-hour PM2.5 air-quality standard as the
Louisville nonattainment area, based upon currently available
information.

The following is a review of data for relevant factors for the Indiana
portion of the Louisville area.

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Louisville area.  Counties that are part of
the Louisville nonattainment area for the 1997 PM2.5 NAAQS are shown in
boldface.  Counties are listed in descending order by CES.

Table 1.  PM2.5 24-hour Component Emissions, and CESs. 

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx

	VOCs

	NH3



Jefferson, KY	No	100	5,941	2,726	3,215	53,066	58,643	38,095	1,628

Floyd, IN	No	33	3,206	285	2,920	57,498	8,169	3,462	258

Clark, IN	No	16	1,398	338	1,060	4,043	5,749	6,049	800

Bullitt, KY	No	6	659	283	376	857	3,140	5,816	182

Oldham, KY	No	6	579	220	359	504	3,306	1,821	254

Harrison, IN	No	5	746	238	507	672	3,423	2,379	1,208

Jefferson, IN	No	3	1,265	168	1,097	75,319	25,214	2,272	341



Clark and Floyd Counties in Indiana both have sizable emissions.  Their
CES ranks them second and third in the area following Jefferson County,
Kentucky.  They rank ahead of Bullitt County.  Jefferson County, Indiana
has a low CES, but it has the largest sulfur dioxide emissions and the
second largest NOx emissions in the area.  Harrison County has a low a
CES and emissions.  Considering the emissions factor, Clark, Floyd, and
Jefferson Counties are good nonattainment candidates in the Indiana
portion of the area.

 

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Jefferson, KY	100	100	100	18.9

Floyd, IN	33	98	88	10.8

Clark, IN	16	85	52	9.3

Bullitt, KY	6	89	91	33.2

Oldham, KY	6	88	63	17.7

Harrison, IN	5	85	81	24.8

Jefferson, IN	3	49	13	29.1



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Louisville area based on data
for the 2005-2007 period.  A monitor’s design value indicates whether
that monitor attains a specified air quality standard.  The 24-hour
PM2.5 standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met. 

The 24-hour PM2.5 design values for counties in the Louisville area are
shown in Table 3.

Table 3.  Air Quality Data

County	State 

Recommended

 Nonattainment?	Design Values

2004-2006	Design Values

2005-2007

Jefferson, KY	No	36	39

Floyd, IN	No	32	35

Clark, IN	No	37	40

Bullitt, KY	No	34	36

Jefferson, IN	No	0	0

Oldham, KY	No	0	0

Harrison, IN	No	0	0



In Indiana, Clark County has a violating design value and therefore must
be designated nonattainment.  Floyd County monitors attainment of the
2006 PM2.5 air quality standards.  There is no monitoring data for
Jefferson County, Indiana.  There are also violations in the Kentucky
portion of the Louisville area.  However, the absence of a violating
monitor alone is not a sufficient reason to eliminate counties as
candidates for nonattainment status.  Each county has been evaluated
based on the weight of evidence of the nine factors and other relevant
information.

For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Louisville area occur about 82% in the
warm season and 18% in the cool season.  In the warm season, the average
chemical composition of the highest days is 67% sulfate, no nitrate, 30%
carbon, and 3% crustal.  In the cool season, the average chemical
composition of the highest days is 50% sulfate, 23% nitrate, 25% carbon,
and 2% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM  monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards. 

Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/sq mi)

Jefferson, KY	No	   699,051 	1755

Floyd, IN	No	     72,025 	485

Clark, IN	No	   101,625 	270

Bullitt, KY	No	     71,440 	238

Jefferson, IN	No	     32,379 	90

Oldham, KY	No	     53,459 	273

Harrison, IN	No	     36,729 	76



Jefferson County, Kentucky stands out in the Louisville area as having a
much larger population and higher population density that the other
counties.  Clark and Floyd Counties, Indiana and Bullitt County,
Kentucky all have similarly moderate populations.  Jefferson County,
Indiana has a low population and population density.  Factor 3 indicates
that Clark and Floyd Counties are good candidates for being designated
nonattainment in the Indiana portion of Louisville. 

Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Louisville area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.  

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties 	Percent

Commuting to any violating counties 	Number Commuting within/to
statistical area 	Percent

Commuting within/to statistical area 

Jefferson, KY	No	    9,030 	312,660 	95 	    322,950 	          98 

Clark, IN	No	    1,218 	41,100 	85 	      47,410 	          98 

Bullitt, KY	No	       852 	28,570 	94 	      30,160 	          99 

Floyd, IN	No	       768 	18,380 	52 	      34,590 	          99 

Oldham, KY	No	       526 	13,050 	61 	      21,020 	          98 

Harrison, IN	No	       585 	6,200 	36 	      16,550 	          96 

Jefferson, IN	No	       382 	660 	4 	        1,130 	            8 



The listing of counties on Table 4 reflects a ranking based on the
number of people commuting to other counties.  The counties that are in
the nonattainment area for the 1997 PM2.5 NAAQS are shown in boldface. 
The number and percent of commuting to any violating county figures are
all high for Clark County, Indiana along with Jefferson and Bullitt
Counties, Kentucky.  Floyd County, Indiana and Oldham County, Kentucky
show more modest commuting figures.  Harrison County has a modest number
of commuters.  The percent of commuting within the Louisville
statistical area is large for the MSA counties.  A small number and
percent of Jefferson County, Indiana workers commute into the
statistical area.  The VMT and commuting into violating counties data
for Jefferson County, Indiana is also low.  In Indiana, Clark County is
strong candidate for nonattainment and Floyd County is a potential
candidate based on this factor.  Harrison County is a weak candidate. 

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Louisville area, as
well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Louisville area.  Counties are
listed in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Growth and Percent Change.

County	Population (2005)	Population % change (2000-2005)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Jefferson, IN	     32,379 	2 	        382 	          24 

Harrison, IN	     36,729 	6 	        585 	          23 

Oldham, KY	     53,459 	14 	        526 	          19

Jefferson, KY	    699,051 	1 	     9,030 	          18 

Bullitt, KY	     71,440 	16 	        852 	          13 

Clark, IN	    101,625 	5 	     1,218 	          10 

Floyd, IN	     72,025 	2 	        768 	            3 



The Indiana counties showed limited population growth.  Jefferson
County, Indiana has the largest VMT percent expansion.  Yet, it still
has the lowest VMT.  Table 6 shows the VMT growth for other area
counties follows closely behind Jefferson County, Indiana.  The growth
rates are not expected to yield significant changes in the distribution
of population in the area, so this factor did not significantly
influence the decision-making process.

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for Louisville is provided as Figure 2.  The winds on
high concentration days during the warm season show a slight tendency to
be from the Northeast or Southwest.  That is along the Ohio River. 
Still, the wind direction varies frequently and air quality data showed
violations in several area counties.  In particular, winds on occasion
bring emissions from Jefferson County, Indiana, to the Louisville area,
just as on various occasions winds bring emissions from Clark and Floyd
Counties to the violating monitors in Clark County, Indiana, and
Jefferson and Bullitt Counties, Kentucky.  So, it is appropriate under
this factor to include counties in all directions from Louisville.

 

Figure 2

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area.

The Louisville area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  Analysis of
chemical composition data in these areas indicates that the same
components that make up most of the PM2.5 mass in the area on an annual
average basis such as sulfate and direct PM2.5 carbon in many eastern
areas also are key contributors to the PM2.5 mass on days exceeding the
24-hour PM2.5 standard.  These data indicate that in many cities, the
same source categories that contribute to violations of the annual
standard also contribute to exceedances of the 24-hour standard.  

Most areas that were originally designated nonattainment for the PM2.5
standards still have not attained the air quality standards.  Thus, EPA
has generally concluded that counties that were designated as having
emissions sources contributing to fine particle concentrations which
continue to exceed the 1997 standards (all areas violated the annual
standard, two also violated the previous 24-hour standard) also
contribute to fine particle concentrations on the highest days.  For
this reason, EPA believes that for most existing nonattainment areas,
the nonattainment area for the 2006 24-hour standard should be the same.
 Consideration also should be given to existing boundaries and
organizations as they may facilitate air quality planning and the
implementation of control measures to attain the standard.  Areas
already designated as nonattainment represent important boundaries for
state air quality planning.

The Kentuckiana Regional Planning and Development Agency serves as the
Metropolitan Planning Organization (MPO) for Clark and Floyd Counties in
Indiana.

The Louisville ozone maintenance area is made up of Clark and Floyd
Counties in Indiana and Bullitt, Jefferson, and Oldham Counties in
Kentucky.  The fine particulate nonattainment area designed under the
1997 standards is composed of Clark, Floyd, and a portion of Jefferson
County in Indiana along with Bullitt and Jefferson County, Kentucky. 
Thus, under this factor it would be appropriate to include Clark, Floyd,
and a portion of Jefferson County (Madison Township) in Indiana in the
nonattainment area.

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the area before 2005 on stationary, mobile, and area sources.  Data
are presented for PM2.5 components that are directly emitted,
carbonaceous PM2.5 and crustal PM2.5, and for pollutants which react in
the atmosphere to form fine particles such as SO2, NOx, VOC, and
ammonia.  

In considering county-level emissions, EPA used data from the 2005
National Emissions Inventory, the most updated version of the national
inventory available at the beginning of the designations process in late
2007.  However, EPA recognized that for certain counties, emissions may
have changed since 2005.  For example, certain power plants or large
sources of emissions in or near this area may have installed emission
controls or otherwise significantly reduced emissions since 2005.  Some
States provided updated information on emissions and emission controls
in their comments to EPA.  EPA considered such additional information in
making final designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute.

Indiana submitted information on the status of controls of Clifty Creek
Station in Jefferson County, Indiana.  This information indicates that
flue gas desulfurization will be installed on all units at this facility
in 2010, selective catalytic reduction is in place on 5 of 6 units, and
this equipment will be operated on a full year basis in the future. 
However, this information also indicates that current emissions are
relatively high.  Since EPA is promulgating designations based on
current air quality and current emissions contributing to existing
violations as required by the Act, EPA concludes that Madison Township
(including Clifty Creek Station) has relatively high emissions that
contribute to violations of the air quality standard in the Louisville
area and must be included in the Louisville nonattainment area
notwithstanding the fact that additional controls are planned for this
facility at a future date.

EPA has designated three full or partial counties in Indiana and two
Kentucky counties as nonattainment for the 24-hour PM2.5 air-quality
standard as the Louisville nonattainment area based on the technical
analysis.  In Indiana, EPA is designating Clark and Floyd Counties and
Madison Township of Jefferson County as nonattainment.

EPA Technical Analysis for Vincennes, IN 

The Vincennes Micropolitan Statistical Area consists of Knox County. 
EPA reviewed the relevant information for this county as well as for
surrounding counties.  There is a violating monitor in Knox County. 
Knox County was designated as attaining the 1997 standards.  Indiana
recommended that the Vincennes nonattainment area include only Knox
County.

EPA agrees with Indiana’s recommendation.  Knox County is adjacent to
the Evansville area, an area that includes several counties with high
emissions.  Nevertheless, as discussed in the review of the Evansville
nonattainment area, EPA believes that Vincennes warrants being
designated as a separate nonattainment area from Evansville.  Other
Indiana counties near Knox County have relatively low emissions, and no
other factor warranted inclusion of the counties in the Vincennes
nonattainment area.

Figure 1 is a map of the counties in the nonattainment area and other
relevant information such as the locations and design values of air
quality monitors, and the micropolitan area boundary. 

 

Figure 1

In April 2008, EPA also notified Indiana that a monitor in the Vincennes
area was violating based on 2005-2007 data.  Indiana provided EPA with a
recommendation for this area in May 2008.  Indiana recommended that one
county be designated as “nonattainment” for the 2006 24-hour PM2.5
standard based on air quality data from 2005-2007.  These data are from
Federal Reference Method (FRM) monitors located in the state.

In August 2008, EPA notified Indiana of its intended designations.  In
this letter, EPA also requested that if the State wished to provide
comments on EPA’s intended designation, it should do so by October 20,
2008.  EPA stated that it would consider any additional information
(e.g., on power plants or partial county areas) provided by the state in
making final decisions on the designations.  Indiana provided no
information on emission controls in Knox County.

Based on EPA's technical analysis described below, EPA has designated
one county in the Indiana as nonattainment for the 24-hour PM2.5
air-quality standard as part of the Vincennes nonattainment area, based
upon currently available information.  These counties are listed in the
table below.

The following is a review of data for relevant factors for the Vincennes
area. 

Factor 1:  Emissions data

For this factor, EPA evaluated county level emission data for the
following PM2.5 components and precursor pollutants:  “PM2.5 emissions
total,” “PM2.5 emissions carbon,” “PM2.5 emissions other,”
“SO2,” “NOx,” “VOCs,” and “NH3.”  “PM2.5 emissions
total” represents direct emissions of PM2.5 and includes: “PM2.5
emissions carbon,” “PM2.5 emissions other”, primary sulfate (SO4),
and primary nitrate.  (Although primary sulfate and primary nitrate,
which are emitted directly from stacks rather than forming in
atmospheric reactions with SO2 and NOx, are part of “PM2.5 emissions
total,” they are not shown in Table 1 as separate items).  “PM2.5
emissions carbon” represents the sum of organic carbon (OC) and
elemental carbon (EC) emissions, and “PM2.5 emissions other”
represents other inorganic particles (crustal).  Emissions of SO2 and
NOx, which are precursors of the secondary PM2.5 components sulfate and
nitrate, are also considered.  VOCs (volatile organic compounds) and NH3
(ammonia) are also potential PM2.5 precursors and are included for
consideration. 

Emissions data were derived from the 2005 National Emissions Inventory
(NEI), version 1.  See
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.

EPA also considered the Contributing Emissions Score (CES) for each
county.  The CES is a metric that takes into consideration emissions
data, meteorological data, and air quality monitoring information to
provide a relative ranking of counties in and near an area.  Note that
this metric is not the exclusive manner for considering data for these
factors.  A more detailed description can be found at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html#C.

Table 1 shows emissions of PM2.5 and precursor pollutants components
(given in tons per year) and the CES for violating and potentially
contributing counties in the Vincennes area.  Counties are listed in
descending order by CES.

Table 1.  PM2.5 Related Emissions and Contributing Emissions Score

County	State Recommended Nonattainment?	CES	PM2.5

emissions 

total	PM2.5

emissions 

carbon	PM2.5

emissions 

other	SO2

	NOx

	VOCs

	NH3

Gibson, IN	No	100	6,642	420	6,223	154,782	32,655	3,679	1,921

Pike, IN	No	45	2,412	163	2,249	52,836	18,990	1,206	487

Knox, IN	Yes	19	1,250	178	1,073	7,422	3,793	3,270	1,429

Sullivan, IN	No	10	1,572	189	1,383	20,971	11,354	1,851	643



Gibson and Pike Counties were considered with the Evansville area.  The
emissions from Knox County are modest.  Sullivan County has lower
emissions.  With Gibson and Pike Counties being in the Evansville
nonattainment area, Knox County is the only nonattainment candidate in
the Vincennes area from the emissions factor.    

Table 2 provides the data for CES weighting factors.  The trajectory
factors are used in CES calculations to account for seasonal
meteorology.  For the top 10% of days in both the cold and warm seasons,
wind trajectories were run for a 48 hour period preceding the high
monitor reading.  The amount of time the air mass was over a county
within the mixing height was calculated.  The values were scaled so that
the maximum value is 100.  Thus, the county that is most likely to be
upwind of a monitor on a high concentration day in a season is given a
score of 100.  The scores for the other counties will reflect the
relative likelihood of being upwind.  As the concentration of a
pollutant will decrease as it goes further downwind, a distance
weighting factor is also used in calculating the CES.  The distance
factor listed on Table 2 provides the distance from the center of a
county to the center of the violating county.  If a county is violating,
the distance used is the average distance from the center to the county
line.

  Table 2.  CES Factor Data.

County	CES	Trajectory Factor- Cold	Trajectory Factor- Warm	Distance (mi)

Gibson	100	77	85	22.8

Pike	45	82	100	21.2

Knox	19	100	100	12.8

Sullivan	10	89	41	29



Factor 2:  Air quality data 

This factor considers the 24-hour PM2.5 design values (in µg/m3) for
air quality monitors in counties in the Vincennes area based on data for
the 2005-2007 period.  A monitor’s design value indicates whether that
monitor attains a specified air quality standard.  The 24-hour PM2.5
standards are met when the 3-year average of a monitor’s 98th
percentile values are 35 µg/m3 or less.  A design value is only valid
if minimum data completeness criteria are met.

The 24-hour PM2.5 design values for counties in the Vincennes area are
shown in Table 3.  Knox County is the only county with air quality data.
 Its design value is above the air quality standards.  However, the
absence of a violating monitor alone is not a sufficient reason to
eliminate counties as candidates for nonattainment status.  Each county
has been evaluated based on the weight of evidence of the nine factors
and other relevant information.

	Table 3.  Air Quality Data

County	State 

Recommended

Nonattainment?	Design Values

2004-2006

	Design Values

2005-2007

Knox, IN	Yes	36	36

Gibson, IN	No	0	0

Pike, IN	No	0	0

Sullivan, IN	No	0	0



For purposes of its review, EPA used data available from the Chemical
Speciation Network and the Interagency Monitoring of Protected Visual
Environments (IMPROVE) network to estimate the composition of fine
particle mass on days with the highest fine particle concentrations. 
Analysis of these data indicates that the days with the highest fine
particle concentrations in the Vincennes area occur about 80% in the
warm season and 20% in the cool season.  In the warm season, the average
chemical composition of the highest days is 72% sulfate, no nitrate, 24%
carbon, and 3% crustal.  In the cool season, the average chemical
composition of the highest days is 34% sulfate, 34% nitrate, 29% carbon,
and 3% crustal.  These data indicate that sources of SO2, NOx, and
direct PM2.5 emissions contribute to violations in the area.

Note:  Eligible monitors for providing design value data generally
include State and Local Air Monitoring Stations (SLAMS) at
population-oriented locations with an FRM monitor.  All data from
Special Purpose Monitors (SPM) using an FRM is eligible for comparison
to the relevant NAAQS, subject to the requirements given in the October
17, 2006 Revision to Ambient Air Monitoring Regulations (71 FR 61236). 
All monitors used to provide data must meet the monitor siting and
eligibility requirements given in 71 FR 61236 to 61328 in order to be
acceptable for comparison to the 24-hr PM2.5 NAAQS for designation
purposes.

Factor 3: Population density and degree of urbanization (including
commercial development)

Table 4 shows the 2005 population for each county in the area being
evaluated, as well as the population density for each county in that
area.  Population data gives an indication of whether it is likely that
population-based emissions might contribute to violations of the 24-hour
PM2.5 standards.  Knox County along with the other area counties all
have low population figures.  This appears to be a mostly rural county. 


Table 4.  Population

County	State Recommended Nonattainment?	2005 Population	2005 Population
Density (pop/sq mi)

Knox, IN	Yes	     38,298 	73

Gibson, IN	No	     33,347 	67

Pike, IN	No	     12,766 	37

Sullivan, IN	No	     21,675 	48



Factor 4: Traffic and commuting patterns 

This factor considers the number of commuters in each county who drive
to another county within the Vincennes area, the percent of total
commuters in each county who commute within the area, as well as the
total Vehicle Miles Traveled (VMT) for each county in millions of miles
(see Table 5).  A county with numerous commuters is generally an
integral part of an urban area and is likely contributing to fine
particle concentrations in the area.

Table 5.  Traffic and Commuting Patterns

County	State Recommended Nonattainment?	2005 VMT

(106 mi)	Number Commuting to any violating counties	Percent

Commuting to any violating counties 	Number Commuting into statistical
area 	Percent

Commuting into statistical area 

Knox, IN	Yes	       448 	15,020 	85 	      14,910 	          84 

Gibson, IN	No	       469 	640 	4 	           300 	            2 

Sullivan, IN	No	       245 	280 	3 	           280 	            3 

Pike, IN	No	       169 	1,920 	34 	           130 	            2 



The listing of counties on Table 5 reflects a ranking based on the
number of people commuting to other counties.  The commuting data
suggests the Knox County is separate from the other counties.  Indiana
supplied 2005 commuting data.  About 1,400 workers commute from Illinois
into Knox County.  Only a few hundred people commute into Knox County
from each of the adjacent Indiana counties.  Similarly there is modest
commuting from Knox County into other counties.  This factor suggests
there is not a strong link between Knox County and the Evansville area
counties.  Thus, the commuting data suggests Knox County is separate
from the Evansville area.

Note:  The 2005 VMT data used for table 5 and 6 of the 9-factor analysis
has been derived using methodology similar to that described in
“Documentation for the final 2002 Mobile National Emissions Inventory,
Version 3, September 2007, prepared for the Emission Inventory Group,
U.S. EPA.  This document may be found at:
ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/mobile/2002_m
obile_nei_version_3_report_092807.pdf.  The 2005 VMT data were taken
from documentation which is still draft, but which should be released in
2008.

Factor 5:  Growth rates and patterns  

This factor considers population growth for 2000-2005 and growth in
vehicle miles traveled for 1996-2005 for counties in Vincennes area, as
well as patterns of population and VMT growth.  A county with rapid
population or VMT growth is generally an integral part of an urban area
and likely to be contributing to fine particle concentrations in the
area.

Table 6 below shows population, population growth, VMT, and VMT growth
for counties that are included in the Vincennes area.  Counties are
listed in descending order based on VMT growth between 1996 and 2005.

Table 6.  Population and VMT Growth and Percent Change.

County	Population (2005)	Population % change (2000-2005)	2005 VMT

(106 mi)	VMT

% change

(1996-2005)

Gibson, IN	     33,347 	2 	        469 	          19 

Knox, IN	     38,298 	-2	        448 	          15 

Sullivan, IN	     21,675 	0 	        245 	          12 

Pike, IN	     12,766 	0 	        169 	            0



Gibson, Knox, and Sullivan Counties have experienced some VMT growth. 
All these counties still have low VMT.  The populations of all the
counties kept stable.

The growth rates are not expected to yield significant changes in the
distribution of population in the area, so this factor did not
significantly influence the decision-making process.

Factor 6:  Meteorology (weather/transport patterns)

For this factor, EPA considered data from National Weather Service
instruments and other meteorological monitoring sites in the area.  Wind
direction and wind speed data for 2005-2007 were analyzed, with an
emphasis on “high PM2.5 days” for each of two seasons, an
October-April “cold” season and a May-September “warm” season. 
These high days are defined as days where any FRM or FEM air quality
monitors had 24-hour PM2.5 concentrations above 95% on a frequency
distribution curve of PM2.5 24-hour values. 

μg/m3 are denoted with a red or black icon.  A dot indicates the day
occurred in the warm season; a triangle indicates the day occurred in
the cool season.  The center of the figure indicates the location of the
air quality monitoring site, and the location of the icon in relation to
the center indicates the direction from which the wind was blowing on
that day.  An icon that is close to the center indicates a low average
wind speed on that day.  Higher wind speeds are indicated when the icon
is further away from the center.

The pollution rose for the Vincennes area is provided in Figure 2. 
Winds come from a variety of directions.  So, it was appropriate to
analyze counties in all directions from Knox County.

 

Figure 2

Note:  the meteorology factor is also considered in each county’s
Contributing Emissions Score because the method for deriving this metric
included an analysis of trajectories of air masses for high PM2.5 days.

Factor 7:  Geography/topography (mountain ranges or other air basin
boundaries)

The geography/topography analysis evaluates the physical features of the
land that might have an effect on the air shed and, therefore, on the
distribution of PM2.5 over the area.

The Vincennes area does not have any geographical or topographical
barriers significantly limiting air-pollution transport within its air
shed.  Therefore, this factor did not play a significant role in the
decision-making process.

Factor 8:  Jurisdictional boundaries

In evaluating the jurisdictional boundary factor, EPA gave special
consideration to areas that were already designated nonattainment in
2005 for violating the 1997 fine particle standards.  However, this area
was designated attainment for the 1997 standards, so nonattainment area
boundaries for the 1997 standards were not a factor in determining this
area’s boundaries.

Knox County is not in any current or former nonattainment areas.  There
is not a metropolitan planning organization for Vincennes.

The Vincennes Micropolitan Statistical area, consisting of Knox County,
is immediately adjacent to the Evansville Metropolitan Statistical Area.
 EPA commonly finds that adjoining metropolitan areas influence their
neighbor’s air quality.  On the other hand, such influences occur
across broad distances in the Eastern United States.  EPA interprets the
instruction in the Clean Air Act to designate areas nearby that
contribute to violations as providing that EPA shall not designate a
single Eastern United States nonattainment area.  Instead, EPA generally
designates adjoining urban areas as separate nonattainment areas.

Factor 9:  Level of control of emission sources 

Under this factor, the existing level of control of emission sources is
taken into consideration.  The emissions data used by EPA in this
technical analysis and provided in Table 1 under Factor 1 represent
emissions levels taking into account any control strategies implemented
in the Vincennes area before 2005 on stationary, mobile, and area
sources.  Data are presented for PM2.5 components that are directly
emitted, carbonaceous PM2.5 and crustal PM2.5, and for pollutants which
react in the atmosphere to form fine particles such as SO2, NOx, VOC,
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 to EPA.  EPA considered such additional information in making final
designation decisions.  

With regard to nearby power plants, EPA considered information about
whether a specific plant installed federally enforceable emission
controls by December 2008 resulting in significant emissions reductions.
 A control requirement is considered to be federally-enforceable if it
is required by a State regulation adopted in a State implementation
plan, if it is included in a federally-enforceable Title V operating
permit, or if it is required by a consent decree which also requires the
controls to be included in federally enforceable permit upon termination
of the consent decree.  In making final decisions, EPA also considered
whether a facility would continue to emit pollutants which contribute to
PM2.5 exceedances even after emission controls are operational. 

There are no large emission sources in Knox County.  Emissions from
large sources outside the Knox County may be controlled by national
control programs or by local measures.  EPA has several national
emission control program reducing the emissions of fine particulate
precursors across the country.  These programs will help lower regional
background levels of fine particulate, helping nonattainment areas
around the nation.  Local control measures put in place to bring other
Midwestern nonattainment areas meet the air quality standards will also
reduce fine particulate and precursor pollution that is transported
beyond the nonattainment area. 

Note: EPA has provided a thorough response to each of the specific
comments raised by the State in the Response to Comments document. 
Additional information regarding responses to specific State comments
can be found in EPA’s Response to Comments document at   HYPERLINK
"http://www.epa.gov/pmdesignations/2006standards/tech.htm" 
http://www.epa.gov/pmdesignations/2006standards/tech.htm .

 EPA designated nonattainment areas for the 1997 fine particle standards
in 2005.  In 2006, the 24-hour PM2.5 standard was revised from 65
micrograms per cubic meter (average of 98th percentile values for 3
consecutive years) to 35 micrograms per cubic meter; the level of the
annual standard for PM2.5 remained unchanged at 15 micrograms per cubic
meter (average of annual averages for 3 consecutive years).  

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