1

---------------------------------------------------------------------------------------------------------------------------

Technical Support Document (TSD)

Indiana

Area Designations For the 

2010 SO2 Primary National Ambient Air Quality Standard

Summary

Pursuant to section 107(d) of the Clean Air Act (CAA), EPA must designate areas as either 

“nonattainment,” “attainment,” or “unclassifiable” for the 2010 one-hour sulfur dioxide (SO2) primary 

national ambient air quality standard (NAAQS). The CAA defines a nonattainment area as one that 

does not meet the NAAQS or that contributes to poor air quality in a nearby area that does not meet the 

NAAQS. Table 1 below identifies the counties or portions of counties (or tribal areas) in Indiana that 

EPA intends to designate “nonattainment” for the primary 2010 SO2 NAAQS.

Indiana submitted designation recommendations on May 11, 2011 with supplemental 

recommendations on January 6, 2012 and April 26, 2012. On February 6, 2013, EPA sent a letter with 

intended designations for Indiana. Indiana responded with March 11, 2013 and March 28, 2013 

recommendations. Table 1 below lists Indiana’s final recommendations and identifies the counties or 

portions of counties in Indiana that EPA is initially designating “nonattainment” based on monitored 

violations. EPA is not yet prepared to designate other areas in Indiana, and will address such areas and 

their sources in a subsequent round of final designations.

Table 1. Nonattainment Area Designations for Indiana

Area Indiana’s Recommended 

Designation of Areas/Counties

EPA’s Nonattainment 

Designation of Areas/Counties

Indianapolis, IN 

 Marion County (partial)

 -Wayne, Center and Perry Townships

Nonattainment Nonattainment 

Morgan County, IN

 Morgan County (partial)

 -Clay and Washington Townships

Nonattainment Nonattainment 

Southwest Indiana, IN

 Daviess County (partial)

 -Veale Township

 Pike County (partial)

 -Washington Township

Nonattainment

Nonattainment

Nonattainment 

Nonattainment

Terre Haute, IN

 Vigo County (partial)

 -Fayette and Harrison Township

Nonattainment Nonattainment 

Background

On June 3, 2010, EPA revised the primary SO2 NAAQS (75 FR 35520, June 22, 2010) by establishing 

a new 1-hour standard at a level of 75 parts per billion (ppb), which is met at an ambient air quality 

monitoring site when the 3-year average of the annual 99th percentile of the daily maximum 1-hour 

average concentration at each monitor in an area does not exceed 75 ppb, as determined in accordance 

with Appendix T of 40 CFR part 50. 40 CFR 50.17(a)-(b). EPA has determined that this is the level 

necessary to provide protection of public health with an adequate margin of safety, especially for 
2

children, the elderly and those with asthma. These groups are particularly susceptible to the health 

effects associated with breathing SO2. The Agency is revoking the two prior primary standards of 140 

ppb evaluated over 24-hours, and 30 ppb evaluated over an entire year because the standards will not 

add additional public health protection given a 1-hour standard at 75 ppb. Accordingly, EPA is not 

designating areas in this process on the basis of either of these two prior primary standards. Similarly, 

the secondary standard for SO2 has not been revised, so EPA is not designating areas in this process on 

the basis of the secondary standard.

EPA’s SO2 Designation Approach

Section 107(d) of the CAA provides that not later than 1 year after promulgation of a new or revised 

NAAQS, state Governors may submit their recommendations for designations and boundaries to EPA. 

For the 2010 SO2 NAAQS, this deadline was June 3, 2011. Section 107(d) also requires EPA to

provide a notification to states of no less than 120-days prior to promulgating an initial area 

designation that is a modification of a state’s recommendation. EPA has reviewed the State’s 

recommendations and has notified the State Commissioner through letter signed by the Regional 

Administrator of any intended modifications. [While language in section 107 specifically addresses 

states, we intend to follow the same process for tribes, pursuant to section 301(d) of the CAA and 

Tribal Authority Rule (40 CFR Part 49). Therefore, we intend to designate tribal areas, in consultation 

with the tribes, on the same schedule as state designations.] If a State or Tribe did not submit 

designation recommendations, EPA is to promulgate the designations that it deems appropriate. If a 

state or tribal government disagrees with EPA’s intended area designations, it had an opportunity to 

demonstrate why any proposed modification is inappropriate. 

Designations guidance was issued by EPA through a March 24, 2011, memorandum from Stephen D. 

Page, Director, U.S. EPA, Office of Air Quality Planning and Standards, to Air Division Directors, 

U.S. EPA Regions I-X. This memorandum identifies factors EPA intends to evaluate in determining 

boundaries for areas designated nonattainment. These 5 factors include: 1) Air quality data; 2) 

Emissions and emissions-related data (location of sources and potential contribution to ambient SO2

concentrations); 3) Meteorology (weather/transport patterns); 4) Geography/topography (mountain 

ranges or other air basin boundaries); and 5) Jurisdictional boundaries (e.g., counties, air districts, preexisting nonattainment areas, reservations, metropolitan planning organization), among any other 

information deemed relevant to establishing appropriate area designations and boundaries for the 1-

hour SO2 NAAQS.

The March 24, 2011, designations guidance memo recommended that area boundaries be defaulted to 

the county boundary unless additional provided information justifies a larger or smaller boundary than 

that of the county. EPA believes it is appropriate to evaluate each potential area on a case-by-case 

basis, and to recognize that area-specific analyses conducted by states, tribes and/or EPA may support 

a different boundary than a default county boundary.

In this TSD, EPA discusses its review and technical analysis of the recommendations submitted by 

Indiana for designations of the 1-hour SO2 standard and any modifications from these 

recommendations.

Definition of important terms used in this document:
3

1) Designated nonattainment area – an area which EPA has determined, based on a state 

recommendation and/or on the technical analysis included in this document, has violated the 2010 SO2

NAAQS, based on the most recent three years of air quality monitoring data from 2009-2011, or 

contributes to a violation in a nearby area. 

2) Recommended nonattainment area – an area that a state or tribal government has recommended 

to EPA to be designated as nonattainment.

3) Violating monitor – an ambient air monitor meeting all methods, quality assurance and citing 

criteria and requirements whose valid design value exceeds 75 ppb, as described in Appendix T of 40 

CFR part 50.

4) 2010 SO2 NAAQS - 75 ppb, national ambient air quality standard for SO2 promulgated in 2010. 

Based on the 3-year average of the 99th percentile of the annual distribution of daily maximum 1-hour 

average concentrations

5) Design Value – a statistic computed according to the data handling procedures of the NAAQS (in 

40 CFR 50 Appendix T) that, by comparison to the level of the NAAQS, indicates whether the area is 

violating the NAAQS.

Technical analysis for the Indianapolis, IN Area

Introduction 

This technical analysis for the Indianapolis, IN Area identifies Marion County with a monitor that 

violates the 2010 SO2 NAAQS, and evaluates nearby counties for contributions to SO2 concentrations 

in the area. EPA has evaluated this county and nearby counties based on a review of the evidence for 

the factors recommended in the March 24, 2011 EPA designations guidance. 

Figure 1 is a map of the area showing the locations and design values of air quality monitors in the 

area, and the counties surrounding any violating air quality monitors.
4

Figure 1. Map of Indianapolis, IN area sources and monitors

For the Indianapolis, IN area, Indiana recommended that a portion of Marion County consisting of 

Center, Perry, and Wayne Townships be designated nonattainment.

Based on EPA's technical analysis described below, EPA agrees with the State’s recommendation. 

Thus, EPA is initially designating the three recommended townships in Marion County in Indiana as 

nonattainment for the 2010 SO2 NAAQS to define the Indianapolis nonattainment area. Areas and 

sources that we are not prepared to conclude are contributing to the monitored violations or to possible 

other violations are not included in this initial nonattainment area. Such areas and sources will be 

further addressed in a subsequent round of final designations.

Detailed Assessment

Air Quality Data 

This factor considers the SO2 air quality monitoring data, including the design values (in ppb) 

calculated for all air quality monitors in Marion County in the Indianapolis area and the surrounding 

area based on data for the 2009 to 2011 period.

The 2010 SO2 NAAQS design values for Marion County, Indiana in the Indianapolis, IN area is shown

in Table 2.
5

Table 2. Air Quality Data for Monitors in Marion County

County State Recommended

Nonattainment?

Monitor Air Quality 

System ID

Monitor Location SO2 Design Value, 

2009-2011 (ppb)

Marion Yes 18-097-0057 39.749, -86.1836 80

Marion No 18-097-0073 39.7895, -86.0608 56

Marion No 18-097-0078 39.8111, -86.1145 40*

* Data are incomplete.

Monitor in Bold has the highest 2009-2011 design value in the respective county.

Center Township in Marion County shows a monitored violation of the 2010 SO2 NAAQS. Therefore,

some area in this county and possibly additional areas in surrounding counties must be designated 

nonattainment. The absence of a violating monitor alone is not a sufficient reason to eliminate nearby 

counties as candidates for nonattainment status. Each area has been evaluated based on the evidence 

for the five factors and other relevant information. 

Emissions and Emissions-Related Data

Evidence of SO2 emissions sources in the vicinity of a violating monitor is an important factor for 

determining whether a nearby area is contributing to a monitored violation. For this factor, EPA 

evaluated county level emission data for SO2 and any growth in SO2 emitting activities since the date 

represented by those emissions data.

Emissions 

EPA recognizes that there might be no new information on any changes in emissions that may have 

occurred after 2008, but would consider more recent years if available. Indiana did not provide 

updated emissions information, therefore EPA relied on the 2008 National Emissions Inventory (NEI)

emissions data (NEI08V3). 

Table 3 shows total emissions of SO2 (given in tons per year) for violating and potentially contributing 

counties in and around the Indianapolis area and sources emitting greater than 100 tons per year of SO2

according to the 2008 NEI. 

Table 3. SO2 Emissions (NEI08V3)

County Facility Located in 

State 

Recommended 

Nonattainment Area?

Facility – Total SO2 Air 

Emissions NEI08V3 

(tons per year)

Facility Location Total County 

SO2 Emissions 

(tons per year)

Marion, IN Yes IPL Harding Street Station19,57839.7119, -86.1975 26,544

Yes C C Perry K Steam Plant4,493

39.7622, -86.1667

Yes Rolls-Royce Corporation 

Plant 5 & 8- 142

39.7245, -86.2696

Yes Covanta Indianapolis Inc110 

39.7337, -86.1888

Partial Indianapolis Intl Airport10239.7066, -86.321

The four sources that are fully in the nonattainment area recommended by the state are relatively near 

the violating monitor. The Indianapolis International Airport has relatively low emissions and is 
6

located approximately 13 kilometers from the violating monitor. However, Indiana recommended 

boundaries for administrative convenience that include some but not all of this airport.

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 3 represent emissions 

levels taking into account any control strategies implemented on stationary sources in the Indianapolis

area up to and including 2008. EPA has not received any additional information on emissions 

reductions resulting from controls put into place after 2008.

Meteorology (weather/transport patterns)

Evidence of source-receptor relationships between specific emissions sources and high SO2 values at 

violating monitors is another important factor in determining the appropriate contributing areas and the 

appropriate extent of the nonattainment area. Figure 2 shows the prevalent wind direction for the 

Indianapolis area. 

Figure 2: Wind Rose for Indianapolis, IN

Source: IDNR Software: WRPLOT-Lakes Environmental Software

The wind rose above shows that winds are most likely to come from the southwest but occasionally 

come from the northeast and other directions. This shows that a source from any direction could 

contribute to the violation at the monitor. The wind blows more frequently from the IPL Harding 

Street Station southwest of the monitor, but also blows past the C C Perry K Steam Plant to the 

northeast. 
7

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

The Indianapolis area does not have any geographical or topographical barriers significantly limiting 

air-pollution transport within its airshed. Therefore, this factor did not play a significant role in 

determining the nonattainment boundary.

Jurisdictional boundaries 

Once the geographic area associated with the area violating the SO2 standard and the nearby areas 

contributing to the violations are determined, we considered existing jurisdictional boundaries for the 

purpose of providing a clearly defined legal boundary for carrying out the air quality planning and 

enforcement functions of the area. Indiana did not have any nonattainment areas under the prior SO2

NAAQS. EPA finds that county or township boundaries in Indiana provide a suitable administrative 

basis for formulating nonattainment area boundaries. 

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for 

this area.

Conclusion

After considering the factors described above, EPA is initially designating, based on monitored 

violations, Wayne, Center, and Perry Townships in Marion County as the Indianapolis, IN

nonattainment area for the 2010 SO2 NAAQS. An air quality monitor in Center Township within 

Marion County shows a violation of the 2010 SO2 NAAQS, based on 2009 to 2011 air quality data. 

EPA finds these three townships include the sources that contribute to this monitored violation. Based 

on the consideration of all the relevant and available information, as described above, EPA believes 

that the boundaries described herein encompass the appropriate initial nonattainment area addressing 

the monitored violation. EPA is not ready to conclude that the emissions from sources located outside 

the boundary recommended by Indiana contribute to the monitored violation or to other possible 

violations. In a subsequent round of designations, we will make final initial designation decisions for 

areas in Indiana not included in the nonattainment area designations addressed in this TSD.

Technical analysis for Morgan County, IN

Introduction 

This technical analysis for Morgan County, IN identifies Morgan County with a monitor that violates

the 2010 SO2 NAAQS, and evaluates nearby counties for contributions to SO2 concentrations in the 

area. EPA has evaluated this county and nearby counties based on the evidence for the factors 

recommended in the March 24, 2011 EPA designations guidance. 

Figure 3 is a map of the area showing the locations and design values of air quality monitors in the 

area, and the counties surrounding any violating air quality monitors.
8

Figure 3. Map of Morgan County, IN area sources and monitors

For the Morgan County, IN area, Indiana recommended that a portion of Morgan County consisting of 

Clay and Washington Townships be designated nonattainment.

Based on EPA's technical analysis described below, EPA agrees with the State’s recommendation for

the Morgan County nonattainment area, based upon currently available information. Thus, EPA is 

initially designating the recommended townships as nonattainment for the 2010 SO2 NAAQS as the 

Morgan County, IN area. These townships are listed above in Table 1. Areas and sources that we are 

not prepared to conclude are contributing to the monitored violations are not included in this initial 

nonattainment area, and will be addressed in a subsequent round of final designations.

Detailed Assessment

Air Quality Data 

This factor considers the SO2 air quality monitoring data, including the design values (in ppb) 

calculated for all air quality monitors in Morgan County in the Morgan County area and the 

surrounding area based on data for the 2009 to 2011 period.

The 2010 SO2 NAAQS design values for Morgan County, Indiana in the Morgan County area are 

shown in Table 4.
9

Table 4. Air Quality Data for Nonattainment Designations in Morgan County

County State Recommended

Nonattainment?

Monitor Air Quality 

System ID

Monitor Location SO2 Design Value, 

2009-2011 (ppb)

Morgan Yes 18-109-1001 39.515, -86.3917 100

Monitors in Bold have the highest 2009 to 2011 design value in the respective county.

Clay Township in Morgan County shows a violation of the 2010 SO2 NAAQS. Therefore, some area 

in this county and possibly additional areas in surrounding counties must be designated nonattainment. 

The absence of a violating monitor alone is not a sufficient reason to eliminate nearby counties as 

candidates for nonattainment status. 

Emissions and Emissions-Related Data

Evidence of SO2 emissions sources in the vicinity of a violating monitor is an important factor for 

determining whether a nearby area is contributing to a monitored violation. For this factor, EPA 

evaluated county level emission data for SO2 and any growth in SO2 emitting activities since the date 

represented by those emissions data.

Emissions 

EPA recognizes that there might be no new information on any changes in emissions that may have 

occurred after 2008, but would consider more recent years if available. Indiana did not provide 

updated emissions information, therefore EPA relied on the 2008 National Emissions Inventory (NEI)

emissions data (NEI08V3). 

Table 5 shows total emissions of SO2 (given in tons per year) for violating and potentially contributing 

counties in and around the Morgan County area and sources emitting greater than 100 tons per year of 

SO2 according to the 2008 NEI. 

Table 5. SO2 Emissions (NEI08V3)

County Facility Located in 

State 

Recommended 

Nonattainment Area?

Facility – Total SO2 Air

Emissions NEI08V3

(tons per year)

Facility Location Total County 

SO2 Emissions 

(tons per year)

Morgan, IN Yes IPALCO- Pritchard Station13,102

39.4867, -86.4165 13,819

Yes Hydraulic Press Brick Co.-

515

39.538744, -86.370648

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 5 represent emissions 

levels taking into account any control strategies implemented on stationary sources in the Morgan 

County area up to and including 2008. EPA has not received any additional information on emissions 

reductions resulting from controls put into place after 2008.
10

Meteorology (weather/transport patterns)

Evidence of source-receptor relationships between specific emissions sources and high SO2 values at 

violating monitors is another important factor in determining the appropriate contributing areas and the 

appropriate extent of the nonattainment area. Due to the proximity of the areas, the wind rose in 

Figure 2 for the Indianapolis Area is still an appropriate representation of the wind patterns for the 

Morgan County Area. Therefore, given that the wind is likely from any direction, the wind is most 

frequently from the southwest near the IPALCO- Pritchard Station, but is still possible from the 

northeast past the Hydraulic Press Brick Company.

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

The Morgan County area does not have any geographical or topographical barriers significantly 

limiting air-pollution transport within its airshed. Therefore, this factor did not play a significant role 

in determining the nonattainment boundary.

Jurisdictional boundaries 

Once the geographic area associated with the area violating the SO2 standard and the nearby areas 

contributing to the violations are determined, we considered existing jurisdictional boundaries for the 

purpose of providing a clearly defined legal boundary for carrying out the air quality planning and 

enforcement functions of the area. Indiana did not have any nonattainment areas under the prior SO2

NAAQS standard. EPA finds that county and township boundaries are a suitable administrative basis 

for defining a nonattainment area.

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for 

this area.

Conclusion

After considering the factors described above, EPA is initially designating Clay and Washington 

Townships within Morgan County (as listed in Table 1) to comprise the Morgan County, IN

nonattainment area for the 2010 SO2 NAAQS, based on a monitored violation in the county.

The air quality monitor in Morgan County shows a violation of the 2010 SO2 NAAQS, based on 2009 

to 2011 air quality data. EPA finds these two townships include the sources that contribute to this 

monitored violation. Based on the consideration of all the relevant and available information, as

described above, EPA believes that the boundaries described herein encompass the appropriate initial 

nonattainment area for the 2010 SO2 NAAQS. EPA is not ready to conclude that the emissions from 

sources located outside this boundary contribute to the monitored violation or to other possible 

violations. In a subsequent round of designations, we will make final initial designation decisions for 

areas in Indiana not included in the nonattainment area designations addressed in this TSD.
11

Technical analysis for Southwest Indiana, IN

Introduction 

This technical analysis for Southwest Indiana, IN identifies Daviess and Pike Counties with monitors

that violate the 2010 SO2 NAAQS, and evaluates nearby counties for contributions to SO2

concentrations in the area. EPA has evaluated this county and nearby counties based on the evidence 

for the factors recommended in the March 24, 2011 EPA designations guidance.

Figure 4 is a map of the area analyzed showing the locations and design values of air quality monitors 

in the area, and the counties surrounding any violating air quality monitors.

Figure 4. Map of Southwest Indiana area sources and monitors

For the Southwest Indiana, IN area, Indiana recommended that Veale Township within Daviess 

County and Washington Township within Pike County be designated nonattainment. 

Based on EPA's technical analysis described below, EPA agrees with the state’s recommendation for 

the boundaries of the Morgan County nonattainment area for the 2010 SO2 NAAQS. Thus, EPA is 

initially designating the two recommended townships in Morgan County as nonattainment for the 2010

SO2 NAAQS to define the Morgan County, IN nonattainment area. The townships included in the 

nonattainment area are listed above in Table 1. Areas and sources that we are not yet prepared to 

conclude are contributing to the monitored violations are not included in this initial nonattainment 

area, and will be addressed in a subsequent round of final designations.
12

Detailed Assessment

Air Quality Data 

This factor considers the SO2 air quality monitoring data, including the design values (in ppb) 

calculated for all air quality monitors in Daviess and Pike counties in the Southwest Indiana area and 

the surrounding area based on data for the 2009 to 2011 period.

The 2010 SO2 NAAQS design values for Daviess and Pike Counties, Indiana in the Southwest Indiana

area are shown in Table 6.

Table 6. Air Quality Data for Nonattainment Designations in Southwest Indiana

County State Recommended

Nonattainment?

Monitor Air Quality 

System ID

Monitor Location SO2 Design Value, 

2009-2011 (ppb)

Daviess Yes 180270002 38.5728, -87.2147 118

Pike Yes 181250005 38.5192, -87.2497 175

Monitors in Bold have the highest 2009 to 2011 design value in the respective county.

Veale Township within Daviess County and Washington Township within Pike County show

monitored violations of the 2010 SO2 NAAQS. Therefore, some area in these counties and possibly 

additional areas in surrounding counties must be designated nonattainment. The absence of a violating 

monitor alone is not a sufficient reason to eliminate nearby counties as candidates for nonattainment 

status. 

Emissions and Emissions-Related Data

Evidence of SO2 emissions sources in the vicinity of a violating monitor is an important factor for 

determining whether a nearby area is contributing to a monitored violation. For this factor, EPA 

evaluated county level emission data for SO2 and any growth in SO2 emitting activities since the date 

represented by those emissions data.

Emissions 

EPA recognizes that there might be no new information on any changes in emissions that may have 

occurred after 2008, but would consider more recent years if available. Indiana did not provide 

updated emissions information, therefore EPA relied on the 2008 National Emissions Inventory (NEI)

emissions data (NEI08V3). 

Table 7 shows total emissions of SO2 (given in tons per year) for violating and potentially contributing 

counties in and around the Southwest Indiana area and sources emitting greater than 100 tons per year 

of SO2 according to the 2008 NEI. The counties that contain the Southwest Indiana nonattainment 

area for the 2010 SO2 NAAQS are shown in bold. Both sources in Pike County are located in 

Washington Township.
13

Table 7. SO2 Emissions (NEI08V3)

County Facility Located in State 

Recommended 

Nonattainment Area?

Facility – Total SO2 Air 

Emissions NEI08V3

(tons per year)

Facility Location Total County 

SO2 Emissions 

(tons per year)

Pike Yes Hoosier Energy - Ratts 

Station- 27,334

38.5183, -87.2722 49,846

Yes IPL Petersburg Generating 

Station - 22,494

38.5267, -87.2525

Daviess None 142

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 7 represent emissions 

levels taking into account any control strategies implemented on stationary sources in the Southwest

Indiana area up to and including 2008. EPA has not received any additional information on emissions 

reductions resulting from controls put into place after 2008.

Meteorology (weather/transport patterns)

Evidence of source-receptor relationships between specific emissions sources and high SO2 values at 

violating monitors is another important factor in determining the appropriate contributing areas and the 

appropriate extent of the nonattainment area. Below, in Figure 5, is a wind rose depicting the wind 

patterns for Southwest Indiana. The wind data is based out of Evansville, Indiana, which is not in the 

nonattainment area, but has close enough proximity to show representative data for the southwest 

Indiana Area. 

Figure 5: Wind Rose for Southwest Indiana

Source: IDNR Software: WRPLOT-Lakes Environmental Software
14

Figure 5 shows that winds are most prevalent from the south to southwest, northwest, and northeast. 

However, wind appears likely from any direction. Therefore, both sources are likely to contribute to 

both violating monitors despite varied proximity. 

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

The Southwest Indiana area does not have any geographical or topographical barriers significantly 

limiting air-pollution transport within its airshed. Therefore, this factor did not play a significant role 

in determining the nonattainment boundary.

Jurisdictional boundaries 

Once the geographic area associated with the area violating the SO2 standard and the nearby areas 

contributing to the violations are determined, we considered existing jurisdictional boundaries for the 

purpose of providing a clearly defined legal boundary for carrying out the air quality planning and 

enforcement functions of the area. Indiana did not have any nonattainment areas under the prior SO2

NAAQS. EPA finds that township and county boundaries provide a suitable administrative basis for 

defining a nonattainment area. 

Other Relevant Information

EPA did not receive additional information relevant to establishing a nonattainment area boundary for 

this area.

Conclusion

After considering the factors described above, EPA is initially designating Veale Township within 

Daviess County and Washington Township within Pike County as the Southwest Indiana, IN

nonattainment area for the 2010 SO2 NAAQS. 

The air quality monitors in Veale Township within Daviess County and Washington Township within 

Pike County show violations of the 2010 SO2 NAAQS, based on 2009 to 2011 air quality data. EPA 

finds Washington Township in Pike County include the sources that contribute to this monitored 

violation. Based on the consideration of all the relevant and available information, as described above, 

EPA is initially designating these two townships nonattainment for the 2010 SO2 NAAQS. EPA is not 

ready to conclude that the emissions from sources located outside the boundary recommended by 

Indiana contribute to the monitored violation or to other possible violations. In a subsequent round of 

designations, we will make final initial designation decisions for areas in Indiana not included in the 

nonattainment area designations addressed in this TSD.
15

Technical analysis for Terre Haute, IN

Introduction 

This technical analysis for Terre Haute, IN identifies Vigo County with monitors that violate the 2010 

SO2 NAAQS and evaluates nearby counties for contributions to SO2 concentrations in the area. EPA 

has evaluated this county and nearby counties based on the evidence for the factors recommended in 

the March 24, 2011 EPA designations guidance.

Figure 6 is a map of the area showing the locations and design values of air quality monitors in the 

area, and the counties surrounding any violating air quality monitors.

Figure 6. Map of Terre Haute, IN area sources and monitors

For the Terre Haute, IN area, Indiana initially recommended that a portion of Vigo County consisting 

of Harrison Township be designated nonattainment. In EPA’s February 6, 2013 letter, EPA stated the 

intention to designate Fayette and Otter Creek Townships in addition to Harrison Township. Indiana 

responded in a March 11, 2013 letter stating that Indiana agrees with the inclusion of Fayette 

Township to encompass the PSI Energy’s Wabash River plant, but does not agree with the inclusion of 

Otter Creek Township for continuity purposes because there are no sources and low population. EPA 

agrees with the assessment of Otter Creek Township and is not including that township in the area 

initially being designated nonattainment. 

Based on EPA's technical analysis described below, EPA is initially designating Harrison and Fayette

townships in Vigo County in Indiana as nonattainment for the 2010 SO2 NAAQS as the Terre Haute

nonattainment area, based upon currently available information. These townships are listed above in 
16

Table 1. Areas and sources that we are not prepared to conclude are contributing to the monitored 

violations are not included in this initial nonattainment area, and will be addressed in a subsequent 

round of final designations.

Detailed Assessment

Air Quality Data 

This factor considers the SO2 air quality monitoring data, including the design values (in ppb) 

calculated for all air quality monitors in Vigo County in the Terre Haute, IN Area and the surrounding 

area based on data for the 2009 to 2011 period.

The 2010 SO2 NAAQS design values for county in the Terre Haute area is shown in Table 8.

Table 8. Air Quality Data for Nonattainment Designations in Vigo County, Indiana

County State Recommended

Nonattainment?

Monitor Air Quality 

System ID

Monitor Location SO2 Design Value, 

2009-2011 (ppb)

Vigo, IN Yes 181671014 39.5147, -87.4078 150

Yes 181670018 39.4861, -87.4014 90

Monitor in Bold has the highest 2009-2011 design value in the county.

Fayette Township in Vigo County shows monitored violations of the 2010 SO2 NAAQS. Therefore,

some area in this county and possibly additional areas in surrounding counties must be designated 

nonattainment. The absence of a violating monitor alone is not a sufficient reason to eliminate nearby 

counties as candidates for nonattainment status. 

Emissions and Emissions-Related Data

Evidence of SO2 emissions sources in the vicinity of a violating monitor is an important factor for 

determining whether a nearby area is contributing to a monitored violation. For this factor, EPA 

evaluated county level emission data for SO2 and any growth in SO2 emitting activities since the date 

represented by those emissions data.

Emissions 

EPA recognizes that there might be no new information on any changes in emissions that may have 

occurred after 2008, but would consider more recent years if available. Indiana did not provide 

updated emissions information, therefore EPA relied on the 2008 National Emissions Inventory (NEI)

emissions data (NEI08V3). 

Table 9 shows total emissions of SO2 (given in tons per year) for the violating and contributing county

in and around the Terre Haute Area and sources emitting greater than 100 tons per year of SO2

according to the 2008 NEI. The county that contains all of the Terre Haute nonattainment area for the 

2010 SO2 NAAQS is shown in bold. 
17

Table 9. SO2 Emissions NEI08V3

County Facility Located in 

State Recommended 

NA Area?

Facility – Total SO2 Air

Emissions NEI08V3

(tons per year)

Facility Location Total County 

SO2 Emissions 

(tons per year)

Vigo, IN Yes PSI Energy - Wabash River75,823

39.53, -87.4247 78,287

Yes International Paper Co- 1,215 39.4408, -87.42295

Yes Wabash River Combined Cycle

Plant- 414

39.530785, -87.424787

No Danisco Sweeteners- 370 39.361448, -87.413742

The most significant source in the area, the PSI Energy – Wabash River facility, is located in Fayette 

Township, just northwest of Harrison Township. Considering the meteorology of the area, discussed 

below, this facility clearly contributes to the violation in Vigo County and must be included in the 

nonattainment area.

Emissions Controls

The emissions data used by EPA in this technical analysis and provided in Table 9 represent emissions 

levels taking into account any control strategies implemented on stationary sources in the Terre Haute

area up to and including 2008. EPA has not received any additional information on emissions 

reductions resulting from controls put into place after 2008.

Meteorology (weather/transport patterns)

Evidence of source-receptor relationships between specific emissions sources and high SO2 values at 

violating monitors is another important factor in determining the appropriate contributing areas and the 

appropriate extent of the nonattainment area. Due to the proximity of the areas, the wind rose in 

Figure 2 for the Indianapolis Area is also an appropriate representation of the wind patterns for the 

Terre Haute, IN Area. Therefore, given that the wind is likely from any direction, the wind is most 

frequently from the southwest near the International Paper Co, but is still possible from the northwest 

past the larger emitter, PSI Energy - Wabash River. 

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

The Terre Haute Area does not have any geographical or topographical barriers significantly limiting 

air-pollution transport within its airshed. Therefore, this factor did not play a significant role in 

determining the nonattainment boundary.

Jurisdictional boundaries 

Once the geographic area associated with the area violating the SO2 standard and the nearby areas 

contributing to the violations are determined, we considered existing jurisdictional boundaries for the 

purpose of providing a clearly defined legal boundary for carrying out the air quality planning and 

enforcement functions of the area. Indiana did not have any nonattainment areas under the prior SO2

NAAQS. EPA finds that township and county boundaries provide a suitable administrative basis for 

defining a nonattainment area.
18

Conclusion

After considering the factors described above, EPA is initially designating Harrison and Fayette 

Townships within Vigo County as the Terre Haute, IN nonattainment area for the 2010 SO2 NAAQS. 

The air quality monitors in Harrison Township within Vigo County show violations of the 2010 SO2

NAAQS, based on 2009 to 2011 air quality data. EPA finds these two townships include the sources 

that contribute to this monitored violation. Based on the consideration of all the relevant and available 

information, as described above, EPA believes that the boundaries described herein encompass the 

appropriate initial nonattainment area for the 2010 SO2 NAAQS. EPA is not ready to conclude that the 

emissions from sources located outside the boundary recommended by Indiana contribute to the 

monitored violation or to other possible violations. In a subsequent round of designations, we will 

make final initial designation decisions for areas in Indiana not included in the nonattainment area 

designations addressed in this TSD.