INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT

We Protect Hoosiers and Our Environment. 

Mitchell E. Daniels Jr. 100 North Senate Avenue

Governor Indianapolis, Indiana 46204

(317) 232-8603

Thomas W. Easterly Toll Free (800) 451-6027

Commissioner www.idem.IN.gov

 Recycled Paper An Equal Opportunity Employer Please Recycle 

 January 28, 2011 

Ms. Susan Hedman 

Regional Administrator 

U.S. Environmental Protection Agency 

Region 5 

77 West Jackson Boulevard 

Chicago, IL 60604-3950 

Re: Request to Parallel Process the Draft 

Request for Redesignation Petition and 

Maintenance Plan Under the Annual 

National Ambient Air Quality Standard 

for Fine Particles for the Southwestern 

Indiana Nonattainment Area 

Dear Ms. Hedman: 

The Indiana Department of Environmental Management (IDEM) submits a draft 

Redesignation Petition and Maintenance Plan for the Southwestern Indiana Nonattainment Area, 

which was designated as nonattainment of the annual standard for fine particles on April 5, 2005. 

IDEM will conduct a public hearing concerning the Redesignation Petition and Maintenance Plan 

on March 15, 2011, and the public comment period will conclude on March 18, 2011. IDEM 

requests the United States Environmental Protection Agency (U.S. EPA) to proceed with its 

proposed approval of IDEM’s April 3, 2008 submittal and to parallel process this draft submission 

concurrently. 

The attached document consists of the following: 

Redesignation Petition and Maintenance Plan 

 A formal request that the Southwestern Indiana Nonattainment Area be redesignated to 

attainment and reclassified as maintenance. It contains and meets the requirements set 

forth in Section 107 of the Clean Air Act and in U.S. EPA Redesignation Guidance. 

 A maintenance year of 2022 is established and 2015 and 2020 are analyzed as interim 

years. 

 The appendices of the document contain historical air quality trend data, projected 

emission inventory data and thorough documentation of the mobile emissions analysis. 

Motor Vehicle Emissions Budgets 

 Contained in the Redesignation Petition is a new Motor Vehicle Emissions Budget for 

2015 and 2022. The Evansville Metropolitan Planning Organization’s (EMPO)’s travel 
Ms. Hedman, Page 2 

demand forecasting model and the U.S. EPA’s software program referred to as MOBILE6 

were used to determine emissions for the annual fine particle nonattainment area. 

 A conservative margin of safety was applied to the 2015 and 2022 projected emissions. 

 The travel demand model was updated with the best available assumptions. 

 Vehicle registration data gathered from the Indiana Bureau of Motor Vehicles were used to 

replace the MOBILE6 default vehicle age distribution. 

As noted above, IDEM will conduct a public hearing on March 15, 2011, and the public 

comment period will close on March 18, 2011. Upon completion of the public participation 

process and documentation, IDEM will forward the official transcript and a summary and response 

to substantive oral and written comments under separate cover. 

IDEM requests that the U.S. EPA proceed with review and approval of this submittal. If 

you have any questions or need additional information, please contact Scott Deloney, Chief, Air 

Programs Branch, at (317) 233-5694. 

 Sincerely, 

 Keith Baugues 

 Assistant Commissioner 

 Office of Air Quality 

KB/sad/sms 

Enclosures: 

Draft Request for Redesignation Petition and Maintenance Plan Under the Annual National 

Ambient Air Quality Standard for Fine Particles for the Southwestern Indiana 

Nonattainment Area 

Cc: John Mooney, U.S. EPA Region 5 (no enclosures) 

 Matt Rau, U.S. EPA Region 5 (w/ enclosures) 

 John Summerhays, U.S. EPA Region 5 (w/ enclosures) 

Cheryl Newton, U.S. EPA Region 5 (no enclosures) 

 Pat Morris, U.S. EPA Region 5 (no enclosures) 

 Scott Deloney, IDEM (no enclosures) 

 Christine Pedersen, IDEM (no enclosures) 

 Shawn Seals, IDEM (w/ enclosures) 
DRAFT 

REQUEST FOR REDESIGNATION AND 

MAINTENANCE PLAN 

UNDER THE ANNUAL NATIONAL 

AMBIENT AIR QUALITY 

STANDARD FOR FINE PARTICLES 

Southwestern Indiana Area

Prepared By: 

The Indiana Department of Environmental Management 

 January 2011
This page intentionally left blank 

ii
TABLE OF CONTENTS 

1.0 INTRODUCTION....................................................................................................................1 

1.1 Background ................................................................................................................................1 

1.2 Geographical Description ..........................................................................................................2 

1.3 Status of Air Quality ..................................................................................................................3 

2.0 REQUIREMENTS FOR REDESIGNATION ......................................................................3 

2.1 General .......................................................................................................................................3 

2.2 Fine Particle Monitoring ............................................................................................................3 

2.3 Emission Inventory ....................................................................................................................4 

2.4 Modeling Demonstration ...........................................................................................................4 

2.5 Controls and Regulations ...........................................................................................................4 

2.6 Corrective Actions for Potential Future Violations of the Fine Particles Standard ...................5 

3.0 FINE PARTICLES MONITORING .....................................................................................5 

3.1 Fine Particle Monitoring Network .............................................................................................5 

3.2 Ambient Fine Particle Monitoring Data ....................................................................................6

3.3 Quality Assurance ....................................................................................................................11 

3.4 Continued Monitoring ..............................................................................................................11 

4.0 EMISSION INVENTORY ....................................................................................................11 

4.1 Emission Trends .......................................................................................................................11 

4.2 Base Year Inventory ................................................................................................................20 

4.3 Emission Projections ................................................................................................................21 

4.4 Demonstration of Maintenance ................................................................................................25 

4.5 Permanent and Enforceable Emission Reductions ..................................................................26 

4.6 Provisions for Future Updates .................................................................................................26 

5.0 MOBILE SOURCE EMISSION BUDGETS ......................................................................26 

5.1 Onroad Emission Estimations ..................................................................................................26 

5.2 Overview ..................................................................................................................................27 

5.3 Analysis Years .........................................................................................................................27 

5.4 Emission Estimations ...............................................................................................................27 

5.5 Mobile Source Emission Budgets ............................................................................................28 

5.6 Commitment to Amend Motor Vehicle Emission Budgets Using MOVES ............................29 

iii 
6.0 CONTROL MEASURES AND REGULATIONS ..............................................................29 

6.1 Reasonably Available Control Technology (RACT) ...............................................................29 

6.2 Implementation of Past SIP Revisions .....................................................................................30 

6.3 Nitrogen Oxides (NOx) Rule ....................................................................................................30 

6.4 Measures Beyond Clean Air Act SIP Requirements ...............................................................31 

6.5 Controls to Remain in Effect ...................................................................................................35 

6.6 New Source Review Provisions ...............................................................................................35 

7.0 MODELING AND METEOROLOGY................................................................................35 

7.1 Summary of Modeling Results to Support Rulemakings ........................................................36 

7.2 LADCO’s Round 5 Speciated Modeled Attainment Test Results ...........................................39 

7.3 LADCO’s Round 5 Particulate Source Apportionment Results ..............................................40 

7.4 Summary of Existing Modeling Results ..................................................................................43 

7.5 Meteorological Analysis for Southwestern Indiana .................................................................43 

7.6 Surface Air Conditions Present during High Fine Particles Concentration Days ...................43 

7.7 Upper Air Conditions Present during High Fine Particles Concentration Days ......................43 

7.8 Analysis of Atmospheric Conditions during High Fine Particles Concentration Days ...........44 

7.9 Summary of Meteorological Analysis for Southwestern Indiana ............................................45 

8.0 CORRECTIVE ACTIONS ...................................................................................................45 

8.1 Commitment to Revise Plan ....................................................................................................45 

8.2 Commitment for Contingency Measures .................................................................................46 

8.3 Contingency Measures .............................................................................................................46 

9.0 PUBLIC PARTICIPATION ................................................................................................47 

10.0 CONCLUSIONS ..................................................................................................................47 

FIGURES

Figure 3.1 Southwestern Indiana Nonattainment Area ....................................................................6 

Figure 4.1 Regional NOx EGU Reductions between 2002 and 2009 ............................................18 

Figure 4.2 Regional SO2 EGU Reductions between 2002 and 2009 .............................................20 

TABLES

Table 1.1 National Ambient Air Quality Standards for Fine Particles ............................................2 

Table 3.1 Monitoring Data for the Southwestern Indiana Nonattainment Area .............................8 

Table 4.1 Comparison of 2005 Estimated and 2022 Projected Emission Estimates, 

Southwestern Indiana Area ............................................................................................................25 

iv 
Table 4.2 Comparison of 2008 Estimated and 2022 Projected Emission Estimates, 

Southwestern Indiana Area ............................................................................................................25 

Table 5.1 Emission Estimations for Onroad Mobile Sources for the Southwestern 

Indiana PM2.5 Nonattainment Area ................................................................................................28 

Table 5.2 Mobile Source Emission Budgets for the Southwestern Indiana PM2.5 

Nonattainment Area ......................................................................................................................28 

Table 6.1 Trends in EGU NOx Emissions Statewide in Indiana....................................................31 

Table 7.1 Transport Rule Modeling Results from U.S. EPA – 2010 .............................................36 

Table 7.2 LADCO’s Round 6 Modeling Results ...........................................................................38 

Table 7.3 LADCO’s Round 5 SMAT Modeling Results for Southwestern Indiana .....................40 

Table 7.4 Ranking of Highest Number of Days at AQI Levels of Health Concern ......................45 

GRAPHS

Graph 3.1 Design Values for the Southwestern Indiana Nonattainment Area for 

Fine Particles - 2000 through 2009 ..................................................................................................9 

Graph 3.2 Southwestern Indiana Annual Fine Particle Trends - 2000 through 2009 ....................10 

Graph 4.1 Southwestern Indiana Area NOx Point Source Emissions Trends – 2002, 

2005 and 2008 ................................................................................................................................12 

Graph 4.2 Southwestern Indiana Area SO2 Point Source Emissions Trends – 2002, 

2005 and 2008 ................................................................................................................................13 

Graph 4.3 Southwestern Indiana Area Direct PM2.5 Point Source Emissions 

Trends – 2002, 2005 and 2008 .......................................................................................................13 

Graph 4.4 NOx Emissions Trends, All Sources in the Southwestern Indiana 

Area – 2002, 2005 and 2008 ..........................................................................................................15 

Graph 4.5 SO2 Emissions Trends, All Sources in the Southwestern Indiana 

Area – 2002, 2005 and 2008 ..........................................................................................................15 

Graph 4.6 Direct PM2.5 Emissions Trends, All Sources in the Southwestern Indiana 

Area – 2002, 2005 and 2008 ..........................................................................................................16 

Graph 4.7 Regional NOx Emissions from Electric Generating Units - 1999 to 2009 ...................17 

Graph 4.8 Regional SO2 Emissions from Electric Generating Units - 1999 to 2009 ....................19 

Graph 4.9 Comparison of 2005, 2008, 2015, 2020 and 2022 Projected NOx

Emissions for the Southwestern Indiana Area ...............................................................................22 

Graph 4.10 Comparison of 2005, 2008, 2015, 2020 and 2022 Projected SO2

Emissions for the Southwestern Indiana Area ...............................................................................23 

Graph 4.11 Comparison of 2005, 2008, 2015, 2020 and 2022 Direct PM2.5 

Emissions for the Southwestern Indiana Area ...............................................................................23 

Graph 4.12 Comparison of 2005, 2008, 2015, 2020 and 2022 Projected SO2, NOx 

and Direct PM2.5 Emissions Trends for the Southwestern Indiana Area .......................................24 

Graph 7.1 PM2.5 Design Value Trends for the Southwestern Indiana 

Area – 2000 through 2009 

........................................................................................................................................................37 

Graph 7.2 Modeling Results for Southwestern Indiana PM2.5

Monitors – 2009, 2012 and 2018 ...................................................................................................39 

v 
CHARTS

Chart 7.1 Regional/Emission Sector PSAT Results ......................................................................41 

Chart 7.2 Pie Charts - Species Modeled Contributions to the Jasper, Dubois County 

PM2.5 Monitor .................................................................................................................................42 

Chart 7.3 Pie Charts - Species Modeled Contributions to the University of Evansville 

PM2.5 Monitor .................................................................................................................................42 

Chart 7.4 Distribution of PM2.5 Concentration Days on the AQI Levels of Health Concern ........44 

APPENDICES

A-1 Air Quality System (AQS) and Indiana Department of Environmental Management 

(IDEM) Monitor Data Values for the Southwestern Indiana Nonattainment Area (2000-

2009) 

A-2 Air Quality System (AQS) and Indiana Department of Environmental Management 

(IDEM) Monitor Data Values for the Southwestern Indiana Nonattainment Area (2010) 

B Nitrogen Oxides (NOx), Sulfur Dioxides (SO2) and Direct Fine Particulate Matter (PM2.5) 

Point Source Emissions (2002, 2005 and 2008) for the Southwestern Indiana 

Nonattainment Area 

C Nitrogen Oxides (NOx), Sulfur Dioxides (SO2) and Direct Fine Particulate Matter (PM2.5) 

(2002, 2005 and 2008) Emission Trends, All Sources, Southwestern Indiana 

Nonattainment Area 

D Nitrogen Oxides (NOx) and Sulfur Dioxide (SO2) Emissions from Electric Generating 

Units, Southwestern Indiana Nonattainment Area 

E 2005 Base Year Emissions Inventory, 2008 Secondary Validation Year Emissions 

Inventory and 2015, 2020 and 2022 Projected Emissions Inventory for Nitrogen Oxides 

(NOx), Sulfur Dioxides (SO2) and Direct Fine Particulate Matter (PM2.5) in Southwestern 

Indiana Nonattainment Area 

F Example Mobile Source 2002, 2010, 2015 and 2025 Mobile6.2 Input and Output 

 Calculation Files 

G Jasper Post Office Incomplete PM2.5 Monitoring Data Analysis 

H Area Source Standard Operating Procedure (SOP) 

I-1 LADCO Modeling Protocol 

I-2 LADCO Regional Air Quality Analyses for Ozone, PM2.5, and Regional Haze: Technical 

Support Document 

I-3 LADCO Ozone and PM2.5 Modeling Results 

J Nitrogen Oxides (NOx) and Sulfur Dioxides (SO2) Emissions from Electric Generating 

Units, Six State Region 

K PM2.5 Design Value Trends, LADCO Modeling Results for Southwest Indiana, 

Regional/Emission Sector PSAT Results for Jasper, Evansville, Dale and Knox County, 

Speciated Contributions to Jasper and Evansville PM2.5, Distribution of PM2.5 

Concentration Days using AQI Levels 

L Public Participation 

vi
1 

REQUEST FOR REDESIGNATION AND MAINTENANCE PLAN 

UNDER THE ANNUAL NATIONAL AMBIENT AIR 

QUALITY STANDARD FOR FINE PARTICLES 

SOUTHWESTERN INDIANA AREA 

1.0 INTRODUCTION

 

This document supports Indiana’s request that Dubois, Vanderburgh and Warrick counties, 

Montgomery Township in Gibson County, Ohio Township in Spencer County, and Washington 

Township in Pike County (herein referred to as the “Southwestern Indiana Area”), be 

redesignated from nonattainment to attainment of the 1997 annual standard for fine particles. All 

monitors for fine particles in the Southwestern Indiana Area have recorded three years of quality 

assured ambient air quality monitoring data for the years 2007 through 2009, demonstrating 

attainment with the annual standard for fine particles, and the Southwestern Indiana Area is 

thereby eligible for redesignation. 

Section 107 of the Clean Air Act (CAA) establishes specific requirements to be met in order for 

an area to be considered for redesignation, including: 

(a) A determination that the area has attained the annual standard for fine particles. 

(b) An approved State Implementation Plan (SIP) for the area under Section 110(k). 

(c) A determination that the improvement in air quality is due to permanent and 

enforceable reductions in emissions resulting from implementation of the SIP and 

other federal requirements.

(d) A fully approved maintenance plan under Section 175A. 

(e) A determination that all Section 110 and Part D requirements have been met. 

A maintenance plan provides for the continued attainment of the air quality standard by an area 

for a period of ten years after the United States Environmental Protection Agency (U.S. EPA) 

has formally redesignated the area to attainment. The plan also provides assurances that even if 

there is a subsequent exceedance of the air quality standard, measures in the maintenance plan 

will prevent any future occurrences through contingency measures that would be triggered. 

This document addresses each of these requirements, and provides additional information to 

support continued compliance with the annual standard for fine particles. 

1.1 Background

The CAA requires states with areas designated nonattainment of the applicable National 

Ambient Air Quality Standard (NAAQS) for particulate matter to develop SIPs to expeditiously 

attain and maintain the standard. In 1997, U.S. EPA set daily and annual air quality standards 

for fine particles (PM2.5), as shown in Table 1.1. The terms “fine particles” and “PM2.5” are used 

synonymously throughout this document. The PM2.5 standards were legally challenged and 

upheld by the U.S. Supreme Court in February of 2001. In 1999, Indiana began monitoring for 
2 

fine particle concentrations. The U.S. EPA designated areas in Indiana under the fine particle 

standards on December 17, 2004, as attainment, nonattainment or unclassifiable, with an 

effective date of April 5, 2005. 

Table 1.1 

National Ambient Air Quality Standards for Fine Particles 

Annual 24-Hour 

1997 Fine Particles 

Standard (PM2.5) 

15 μg/m3

Annual arithmetic mean, 

averaged over three years 

65 μg/m3

24-hour average, 98th percentile, 

averaged over three years 

2006 Fine Particles 

Standard (PM2.5) 

15 μg/m3

Annual arithmetic mean, 

averaged over three years 

35 μg/m3

24-hour average, 98th percentile, 

averaged over three years 

Note: The Southwestern Indiana Area meets the 1997 and 2006 24-hour NAAQS for fine particles. Since 

this area is solely designated nonattainment under the 1997 annual standard for fine particles, this 

document only addresses the annual standard. 

On December 17, 2004, based on 2001 through 2003 monitoring data, U.S. EPA designated the 

Southwestern Indiana Area as nonattainment of the annual standard for fine particles, and subject 

to Section 172 of the CAA, including the development of a plan to reduce nitrogen oxides (NOx), 

sulfur dioxide (SO2) and direct PM2.5 emissions and a demonstration that the area will meet the 

annual standard for fine particles by April 5, 2010. In order to satisfy these requirements, 

Indiana submitted a redesignation petition and maintenance plan to U.S. EPA on April 3, 2008, 

demonstrating that the Southwestern Indiana Area had met the NAAQS for fine particles by 

April 5, 2010, with an ample margin of safety. The Southwestern Indiana Area monitors have 

continued to meet the annual NAAQS for fine particles since the end of 2009. 

There were no fine particle monitors in the Southwestern Indiana Area that violated the 1997 24-

hour standard for fine particles that currently violate the 2006 24-hour standard for fine particles. 

As a result, the Southwestern Indiana Area was designated nonattainment for fine particles solely 

under the 1997 annual standard. Therefore, this document pertains only to the 1997 annual 

standard for fine particles. 

 The Southwestern Indiana Area nonattainment area for fine particles, as defined in Section 1.2, 

has not previously been subject to nonattainment area rulemakings for fine particles. However, 

the area had been subject to nonattainment area rulemakings under the 1-hour and the 8-hour 

ozone standards. The 1-hour ozone standard was revoked on June 15, 2005 and both 

Vanderburgh and Warrick counties were redesignated to attainment of the 1997 8-hour ozone 

standard on January 30, 2006. 

 

 1.2 Geographical Description

 The Southwestern Indiana nonattainment area for fine particles consists of Dubois, Vanderburgh 

and Warrick counties, Montgomery Township in Gibson County, Ohio Township in Spencer 

County and Washington Township in Pike County. The Southwestern Indiana Area includes 

cities such as Evansville, Jasper, Boonville, Huntingburg, Petersburg and Rockport and such 
3 

towns as Yankeetown, Inglefield, Owensville, Ferdinand, Chandler, Newburgh and Kasson. 

This area is depicted in Figure 3.1. 

 The agency responsible for assuring the nonattainment area for fine particles complies with the 

CAA requirements is the Indiana Department of Environmental Management (IDEM), which is 

responsible for the entire Southwestern Indiana Area. IDEM has worked cooperatively with U.S. 

EPA Region V to address attainment planning issues. 

 1.3 Status of Air Quality

 Monitoring data for fine particles for the three years, 2007 through 2009, demonstrates that air 

quality has met the annual NAAQS for fine particles in the Southwestern Indiana Area. For 

reference purposes, 2010 monitoring data will be included in Appendix A-2 once quality 

assured. This fact, accompanied by the permanent and enforceable reductions in emission levels 

discussed in Section 4.0, justifies a redesignation to attainment for the subject area based on 

Section 107(d)(3)(E) of the CAA. 

2.0 REQUIREMENTS FOR REDESIGNATION

2.1 General

Section 110 and Part D of the CAA list a number of requirements that must be met by 

nonattainment areas prior to consideration for redesignation to attainment. In addition, U.S. EPA 

has published detailed guidance in a document entitled Procedures for Processing Requests to 

Redesignate Areas to Attainment, issued September 4, 1992, to Regional Air Directors. This 

document is hereafter referred to as “Redesignation Guidance.” This Request for Redesignation 

and Maintenance Plan is based on the Redesignation Guidance, supplemented with additional 

guidance received from staff of the Attainment Planning and Maintenance Section of U.S. EPA 

Region V. The specific requirements for redesignation are listed below. 

2.2 Fine Particle Monitoring 

1) A demonstration that the annual standard for fine particles, as published in 40 

CFR 50.13, has been attained. Fine particle monitoring data must show that 

violations of the annual ambient standard are no longer occurring. 

 

2) Ambient monitoring data quality assured in accordance with 40 CFR 58.15, 

recorded in the U.S. EPA Air Quality System (AQS) database and available for 

public view. 

3) A showing that the three-year average of annual values, based on data from all 

monitoring sites in the area or its affected downwind environs, do not exceed 15.0 

micrograms per cubic meter (μg/m3

). This showing must rely on three complete, 

consecutive calendar years of quality assured data. 
4 

4) A commitment that, once redesignated, the state will continue to operate an 

appropriate monitoring network to verify the area is in compliance (maintenance) 

with the standard. 

2.3 Emission Inventory 

1) A comprehensive emission inventory of direct PM2.5 and the precursors of fine 

particles completed for the base year (2005 in this case). 

2) A projection of the emission inventory to a year at least ten years following 

redesignation. 

3) A demonstration that the projected level of emissions is sufficient to maintain the 

annual standard for fine particles. 

4) A demonstration that improvement in air quality between the year violations 

occurred and the year attainment was achieved is based on permanent and 

enforceable emission reductions and not on temporary adverse economic 

conditions or unusually favorable meteorology. 

5) Provisions for future annual updates of the inventory to enable tracking of the 

emission levels, including an annual emission statement from major sources. 

2.4 Modeling Demonstration 

While no modeling is required for redesignating nonattainment areas, IDEM has evaluated the 

results of federal control-case modeling to demonstrate that compliance with the standard will be 

maintained. 

2.5 Controls and Regulations 

1) A U.S. EPA-approved SIP control strategy that includes Reasonably Available 

Control Technology (RACT) requirements for existing stationary sources covered 

by Control Technology Guidelines (CTG) and non-CTG RACT for all major 

sources. 

2) Evidence that control measures required in past SIP revisions have been fully 

implemented. 

 

3) Acceptable provisions to provide for new source review. 

4) Assurances that existing controls will remain in effect after redesignation, unless 

the state demonstrates through photochemical modeling that the standard can be 

maintained without one or more controls. 
5 

5) If appropriate, a commitment to adopt a requirement that all transportation plans 

conform with and are consistent with the SIP. 

2.6 Corrective Actions for Potential Future Violations of the Fine Particles Standard

1) A commitment to submit a revised plan eight years after redesignation. 

2) A commitment to expeditiously enact and implement additional contingency 

control measures in response to exceeding specified predetermined levels 

(triggers) or in the event that future violations of the ambient standard occur. 

3) A list of potential contingency measures that would be implemented in such an 

event. 

4) A list of NOx, SO2 and direct PM2.5 sources potentially subject to future controls. 

3.0 FINE PARTICLES MONITORING

3.1 Fine Particle Monitoring Network

There are currently four Federal Reference Method monitors measuring fine particle 

concentrations in this nonattainment area. These monitors are located as follows: Dubois County 

(Jasper, Indiana) and Vanderburgh County (Mill Road/Buena Vista, Civic Center/Post Office 

and University of Evansville, Evansville, Indiana). The four monitors are operated by IDEM’s 

Office of Air Quality (OAQ). A listing of the monitor readings from 2007 through 2009, is 

shown in Table 3.1 and Appendix A and were retrieved from the U.S. EPA’s Air Quality System 

(AQS). The locations of the monitoring sites for this nonattainment area are shown in Figure 

3.1. 

Included as supporting material are two fine particle monitors that operated in Dubois County 

(Jasper, Indiana) from 2006 to 2008. IDEM also operates two fine particle monitors in nearby 

Spencer County (Dale, Indiana) and Gibson County (Oakland City, Indiana) that are not part of 

the Southwestern Indiana nonattainment area. 
6 

Figure 3.1 

Southwestern Indiana Nonattainment Area 

3.2 Ambient Fine Particle Monitoring Data

The following information summarizes U.S. EPA's "Guideline on Data Handling Conventions 

for the PM NAAQS," U.S. EPA-454/R-99-008, April 1999. Three complete years of fine 

particle monitoring data are required to demonstrate attainment at a monitoring site. The annual 

ambient air quality standard for fine particles is met at an ambient air quality monitoring site 

when the three-year average of the annual average of fine particle concentrations is less than or 

equal to 15.0 μg/m3

. When this occurs, the site is said to be in attainment. While calculating 

design values, three significant digits must be carried in the computations, with final values 

rounded to the nearest 0.1 μg/m3

. Decimals 0.05 or greater are rounded up, and those less than 

0.05 are rounded down, so that 15.049 μg/m3

 is the largest concentration that is less than or equal 

to 15.0 μg/m3

. Values at or below 15.0 μg/m3 meet the standard. Values equal to or greater than 

15.1 μg/m3

 exceed the standard. 
7 

Data handling procedures are applied on an individual basis at each monitor in the area. An 

individual site’s three-year average of the annual average fine particle concentration is also 

called the site’s design value. An area is in compliance with the annual NAAQS for fine 

particles only if all monitoring sites meet the NAAQS. The air quality design value for the area 

is the highest design value among all sites in the area. Table 3.1 outlines the annual fine particle 

values by site and the 2007 through 2009 design values for the 6 active fine particle monitoring 

sites in the Southwestern Indiana Area. In addition, 2 discontinued fine particles monitoring 

sites (Jasper Sport and Jasper Golf) are outlined for historical reference. 
8 

Table 3.1 

Monitoring Data for the Southwestern Indiana Area 

(Annual Average and 2007-2009 Design Values) 

SITE ID COUNTY SITE 

NAME YEAR Annual Average μg/m3 

2007-2009 

Average 

μg/m3 

18-037-0004 Dubois JasperSport1

2007 14.61 

13.45 2008 12.10 

2009 

18-037-0005 Dubois JasperGolf1

2007 14.92 

13.75 2008 12.53 

2009 

18-037-2001 Dubois Jasper-Post 

Office 

2007 14.262

13.23 2008 12.93 

2009 12.49 

18-051-0012 Gibson Oakland 

City4

2007 

11.25 2008 11.33 

2009 11.00 

18-147-0009 Spencer Dale 

2007 14.13 

2008 12.03 12.6 

2009 11.77 

18-163-0006/20 Vanderburgh 

EvansvilleCivic 

Center/Post 

Office6

2007 13.91 

12.9 2008 12.58 

2009 12.32 

18-163-0012/21 Vanderburgh 

EvansvilleMill 

Road/Buena 

Vista7

2007 14.23 

13.1 2008 12.70 

2009 12.28 

18-163-0016 Vanderburgh 

EvansvilleUniversity 

of 

Evansville 

2007 14.21 

13.1 2008 12.53 

2009 12.49 

 

1 The Jasper Sport and Jasper Golf monitors began operation February 1, 2006 and were discontinued on 

December 31, 2008. 

2 Exceptional event data removed from calculations. 

3 Incomplete data see Appendix G. 

4 The Oakland City monitor began operation on January 18, 2008. 

5 Indicates design value is based on two years of data. 

6 The Evansville Civic Center monitor was replaced by the Evansville Post Office monitor and data for 2009 as well 

as the 2007-2009 design value have been combined. 

7 The Evansville Mill Road monitor was replaced by the Evansville Buena Vista monitor and data for 2009 as well 

as the 2007-2009 design value have been combined.
9 

Graph 3.1 visually demonstrates the 2000 through 2009 design values for the Southwestern 

Indiana nonattainment area.

Graph 3.1

Design Values for the Southwestern Indiana Area for 

Fine Particles - 2000 through 2009 

 Red line represents annual PM2.5 standard of 15 μg/m3
10 

Graph 3.2 

Southwestern Indiana Annual Fine Particle Trends - 2000 through 2009 

Red line represents annual PM2.5 standard of 15 μg/m3

The design values for the Southwestern Indiana nonattainment area demonstrate that the annual 

NAAQS for fine particles has been attained. Refer to Appendix A for the complete fine particle 

monitoring data summary for the years 2000 to 2009. 

Graph 3.1 shows the trend in design values for the region, while Graph 3.2 shows the trend for 

annual fine particles. A comprehensive list of the fine particle monitoring sites design values 

over this period is outlined in Appendix A. The area's design values have recently trended 

downward, as emissions have declined due to programs such as the Acid Rain program and 

cleaner automobiles and fuels both regionally and locally. U.S. EPA’s rule to control nitrogen 

oxides from specific source categories (40 CFR Parts 51, 72, 75 and 96, published on October 

17, 1998 and referred to as the “NOx SIP Call”) has significantly reduced emissions from large 

electric generating units (EGUs), industrial boilers and cement kilns. Indiana's NOx SIP Call 

Rule was adopted into the Indiana Administrative Code on June 6, 2001 at 326 IAC 10-3 and 

326 ICA 10-4. The elevated fine particle values for 2005 are considered an abnormal 

occurrence. An analysis of meteorological conditions and monitoring values is included in 

Section 7.0 and supports the conclusion that attainment of the standard as of 2009 is not the 

result of unusually favorable meteorological conditions. It is expected that this downward trend 

will continue as the above programs continue and the U.S. EPA’s proposed Clean Air Transport 

Rule (Transport Rule) is implemented. 
11 

3.3 Quality Assurance

IDEM has quality assured all data shown in Appendix A in accordance with 40 CFR 58.10 and 

recorded the data in the AQS database and, thus, the data is available to the public. 

3.4 Continued Monitoring

Indiana commits to continue monitoring fine particle concentrations at the active sites indicated 

in Table 3.1 and Appendix A. IDEM will consult with U.S. EPA Region V staff prior to making 

changes to the existing Indiana monitoring network through the annual network review should 

changes become necessary in the future. IDEM will continue to quality assure the Indiana 

monitoring data to meet the requirements of 40 CFR 58. IDEM will enter all data into AQS on a 

timely basis in accordance with federal guidelines. 

4.0 EMISSION INVENTORY 

U.S. EPA’s Redesignation Guidance and Implementation Rules require the submittal of a 

comprehensive inventory of precursor emissions for fine particles (NOx, SO2 and direct PM2.5) 

representative of the year when the area achieved attainment of the annual NAAQS for fine 

particles (base year). Indiana is using 2005 as the base year. IDEM must also demonstrate that 

the improvement in air quality between the year that violations occurred and the year that 

attainment was achieved is based on permanent and enforceable emission reductions. Other 

requirements related to the emissions inventory include: a projection of the emission inventory to 

a year at least ten years following redesignation; a demonstration that the projected level of 

emissions is sufficient to maintain the annual standard for fine particles; and, a commitment to 

provide future updates of the inventory to enable tracking of emission levels during the ten year 

maintenance period. Consistent with the implementation rule for fine particles, IDEM and U.S. 

EPA do not consider volatile organic compounds (VOCs) or ammonia (NH3) to be significant 

contributors to fine particles. The following subsections address each of these requirements. 

4.1 Emission Trends

Point Sources

Graphs 4.1, 4.2 and 4.3 show that the trend in point source emissions of NOx, SO2 and direct 

PM2.5 for the Southwestern Indiana Area generally correspond to the years of monitored values 

used in this redesignation petition. A secondary validation year of 2008 is used in this document 

for informational purposes only. The point source data are taken from Indiana's emissions 

reporting program and are based on county point source totals, as opposed to township level 

emissions. The Southwestern Indiana Area had a 33% reduction in NOx point source emissions 

and a slight increase (4%) in SO2 point source emissions from 2002 to 2005. A moderate 

increase in direct PM2.5 point source emissions from 2002 to 2005 is noted, this increase in direct 

PM2.5 emissions is due to the fact that most companies did not submit their direct PM2.5

emissions data in 2002 but did submit direct PM2.5 data in the 2005 emissions inventory. The 

Southwestern Indiana Area had a 29% reduction in NOx point source emissions, and a 36% 
12 

reduction in SO2 point source emissions from 2005 to 2008. As Graph 4.7 illustrates, 

Southwestern Indiana NOx emissions from electric generating units have decreased substantially 

during this time period as well. Graphs and data tables of emissions for the point source 

category can be found in Appendix B. 

Graph 4.1 

Southwestern Indiana Area NOx Point Source Emission Trends - 2002, 2005 and 2008 

‐

20,000

40,000

60,000

80,000

100,000

120,000

140,000

2002 2005 2008

Tons per Year

Nitrogen Oxides Year
13 

Graph 4.2 

Southwestern Indiana Area SO2 Point Source Emission Trends - 2002, 2005 and 2008 

Graph 4.3 

Southwestern Indiana Area Direct PM2.5 Point Source 

Emission Trends - 2002, 2005 and 2008 

‐

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

2002 2005 2008

Tons per Year

Sulfur Dioxide Year

‐

2,000

4,000

6,000

8,000

10,000

12,000

14,000

2002 2005 2008

Tons per Year

Direct Fine Particulate Matter Year
14 

All Anthropogenic Sources

Periodic inventories, which include emissions from all sectors (mobile, area, nonroad and point 

sources), were prepared for 2002, 2005 and 2008. The 2008 data were extrapolated from the 

2005 emission inventory. Graphs 4.4, 4.5 and 4.6 show the trend in anthropogenic source 

emissions for the Southwestern Indiana Area. Regional NOx emission reductions affect fine 

particle levels in the Southwestern Indiana Area far more so than NOx emission reductions 

within the nonattainment area itself. These emission trends roughly follow the years of 

monitored trends discussed in Section 3. There is a downward trend in NOx emissions from 

2002 to 2005 and a further decrease through 2008. The decrease in NOx can be largely attributed 

to the impact of the NOx SIP Call. There is a general downward trend in SO2 emissions from 

2002 to 2008 as well. While an increase in direct PM2.5 anthropogenic source emissions from 

2002 to 2005 for the Southwestern Indiana Area is noted, this increase in direct PM2.5 emissions 

from 2002 to 2005 is due to previously unreported emissions from companies that did not submit 

their direct PM2.5 emissions data in 2002 but did submit direct PM2.5 data in the 2005 emissions 

inventory, from which the 2008, 2015, 2020 and 2022 data is extrapolated. Graphs and data 

tables of emissions from each source category are available in Appendix C. 

Mobile emissions inventories and projections for all counties were prepared by the Evansville 

Metropolitan Planning Organization (EMPO) and the Indiana Department of Transportation and 

are explained in further detail in Section 5.0. All 2005 data for the Southwestern Indiana Area 

are from the 2005 periodic inventory which has been identified as one of the preferred databases 

for SIP development. For the 2008 attainment year, emissions were extrapolated from the 2005 

Lake Michigan Air Directors Consortium’s (LADCO) modeling inventory, using LADCO’s 

growth factors, for all sectors except point sources (electrical generating units and non-electrical 

generating units). Point source emissions for 2008 were compiled from Indiana’s annual 

emissions inventory database. 

The emissions inventory development and emissions projection discussion below, with the 

exception of the mobile emissions inventory and projections, identify procedures used by IDEM 

and LADCO regarding emissions for the Southwestern Indiana Area. 
15 

Graph 4.4 

NOx Emission Trends, All Sources in the Southwestern Indiana Area - 

2002, 2005 and 2008 (With CAIR) 

Graph 4.5 

SO2 Emission Trends, All Sources in the Southwestern Indiana Area - 

2002, 2005 and 2008 (With CAIR) 

‐

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

2002 2005 2008

Tons per Year

Nitrogen Oxides Year

‐

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

2002 2005 2008

Tons per Year

Sulfur Dioxide Year
16 

Graph 4.6 

Direct PM2.5 Emission Trends, All Sources in the Southwestern Indiana Area – 

2002, 2005 and 2008 (With CAIR) 

EGU Sources

Graphs 4.7 and 4.8 show both NOx and SO2 emissions are decreasing substantially in response to 

national programs affecting all EGUs such as the Acid Rain program and the NOx SIP Call. 

Other sectors of the inventory also impact the formation of fine particles, but large regional 

sources such as EGUs have a substantial impact on the formation of fine particles. 

The data were taken from U.S. EPA's Clean Air Markets database located at 

http://www.epa.gov/airmarkets. Data are available sooner for these units than other point 

sources in the inventory because of the NOx SIP Call budget and trading requirements. 

Information from 2003 is significant because some EGUs started operation of their NOx SIP Call 

controls in order to generate Early Reduction Credits for their future year NOx budgets. The first 

season of the NOx SIP Call budget period began May 31, 2004. 

As part of the NOx SIP Call, the states were required to adopt into their rules a budget for all 

large EGUs. Indiana’s budget is referenced in 326 IAC 10-4. The budget represents a statewide 

cap on NOx emissions. Although each unit is allocated emissions based upon historic heat input, 

utilities can meet this budget by over-controlling certain units or purchasing credits from the 

market to account for overages at other units. To summarize, NOx emissions have dramatically 

decreased over the years represented on these graphs. 

These emissions, capped by the state rule, are expected to remain near these levels throughout 

‐

2,000

4,000

6,000

8,000

10,000

12,000

14,000

2002 2005 2008

Tons per Year

Direct Fine Particulate Matter Year
17 

the maintenance period covered by this request. The state cap for the NOx SIP Call remained in 

place through 2008, at which time the CAIR program superseded it. CAIR, issued in March 

2005, adopted by the Indiana Air Pollution Control Board on November 1, 2006, and 

implemented beginning in 2010, will continue to reduce regional EGU NOx emissions statewide 

by approximately another 17% by 2015 and 57% for EGU SO2 emissions by 2015. The D.C. 

Circuit court’s vacatur of CAIR in July of 2008 and subsequent remand without vacatur of CAIR 

in December 2008, directs U.S. EPA to revise the CAIR rule in the future. The proposed 

Transport Rule (CAIR’s replacement rule) will result in similar or greater emission reductions 

than assumed within the current emission inventories once it is implemented. 

As demonstrated by Figure 4.1 and Graph 4.7, significant reductions of NOx associated with the 

NOx SIP Call and preparation for CAIR have been achieved statewide as well as regionally. For 

the six state region (Arkansas, Indiana, Illinois, Kentucky, Missouri and Tennessee) shown in 

Figure 4.1, within the area south of latitude 38 and west of longitude -87 (the southwest quadrant 

denoted by brown lines), there has been a reduction in upwind EGU emissions of more than 

197,000 tons of NOx from 2002 to 2009. These six states are important because they represent 

the predominant upwind states most likely to affect the Southwestern Indiana Area. The specific 

EGU emissions for NOx and SO2 from the southwest quadrant, as well as the change in 

emissions from 1999 to 2009 are listed in Appendix D. 

Graph 4.7 

Regional NOx Emissions from Electric Generating Units - 1999 to 2009 

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Total Nitrogen Oxide Emissions (Tons/Year)

Tons per Year
18 

Figure 4.1 Regional NOx EGU Reductions Between 2002 and 2009 

As demonstrated by Figure 4.2, reductions of regional SO2 from upwind EGUs have also been 

achieved. For the six state region (Arkansas, Indiana, Illinois, Kentucky, Missouri and 

Tennessee) shown in Figure 4.2, in the area south of latitude 38 and west of longitude -87 (the 

southwest quadrant denoted by the brown lines), there has been a reduction of upwind EGU 

emissions of over 24,000 tons of SO2 from 2002 to 2009. The specific EGU emissions for NOx

and SO2 from the southwest quadrant, as well as the change from 1999 to 2009 are listed in 

Appendix D.

Although there are minor fluctuations in the SO2 emissions over time, as shown in Graph 4.8, 

well over 50% reductions have been realized to date. As noted by Graph 4.10 significant 

reductions are expected in SO2 emissions from the CAIR program and BART (Best Available 

Retrofit Technology), once implemented. As a result of the CAIR program, five EGU’s will 

achieve significant reductions in SO2. It is expected that this downward trend will continue as 
19 

the above programs continue and the U.S. EPA’s proposed Transport Rule is implemented. 

Alcoa and Cayuga both installed scrubbers in 2008 that will result in a 90% reduction in SO2

emissions, to meet CAIR rules. Gibson installed Flue Gas Desulfurization (FGD) systems on 

Units 1, 2 and 3 between 2006 and 2008. Clifty Creek is in the process of installing FGD 

systems which will also result in 90% reductions in SO2 at those facilities, despite some 

technology related problems. Wabash Valley was ordered to shut down Units 2, 3 and 5 and 

complied by September 30, 2009. As a result of Wabash Valley’s successful legal appeal, they 

may restart these units in the future. At this time, there is no clear indication that Wabash Valley 

will restart units 2, 3 and 5. Edwardsport is replacing all of the coal fired boilers with an 

Integrated Gasification Combined Cycle (IGCC) system which will result in a slight increase in 

NOx of 32.49 tons per year and a substantial reduction in SO2 of 9,834 tons per year. Also, as a 

result of a recent settlement agreement, American Electric Power (AEP) Rockport will install 

scrubbers to achieve a 90% reduction in SO2. Appendix B shows detailed emissions for the point 

source emissions, and Appendix D shows detailed emissions for the Electric Generating Units. 

Graph 4.8 

Regional SO2 Emissions from Electric Generating Units - 1999 to 2009 

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Total Sulfur Dioxide Emissions (Tons/Year)

Tons per Year
20 

Figure 4.2 Regional SO2 EGU Reductions Between 2002 and 2009 

4.2 Base Year Inventory

IDEM prepared a comprehensive inventory for the Southwestern Indiana Area, including area, 

mobile, nonroad and point sources for direct PM2.5 and precursors of fine particles (NOx and 

SO2) for 2005 and 2008 (the years with the most complete emissions inventories available at this 

time). The 2005 emission inventory represents a base year for maintenance purposes. The 2007 

implementation rule for the annual fine particle standard states that NOx, SO2 and direct PM2.5

are the regulated precursors of fine particles. Ammonia and VOCs are not required to be 

addressed unless the state or U.S. EPA makes a technical demonstration that emissions of these 

pollutants from sources in the state significantly contribute to PM2.5 concentrations in a given 

nonattainment area. U.S. EPA and IDEM have not determined ammonia or VOCs to be 

significant contributors to fine particles formation in the State of Indiana. Indiana’s 2005 base 

year inventory was determined by the following: 
21 

 Area sources were extrapolated from the Indiana 2005 periodic inventory submitted to 

U.S. EPA. 

 Mobile source emissions were calculated from MOBILE6.2 model-produced emission 

factors and data extracted from the region’s travel-demand model. These emissions were 

then interpolated as needed to determine 2005 base year values. 

 Point source information was compiled from IDEM’s emissions statement database and 

U.S. EPA's Clean Air Markets acid rain database. 

 Biogenic emissions are not specifically included in these summaries, but are included in 

the photochemical modeling results represented in Section 7. 

 Nonroad emissions were extrapolated from the 2002 National Emissions Inventory 

(NEI). To address concerns about the accuracy of some of the categories in U.S. EPA’s 

nonroad emissions model, LADCO contracted with two companies to review the base 

data and make recommendations. One of the contractors also estimated emissions for 

two nonroad categories not included in U.S. EPA's nonroad model. Emissions were 

estimated for commercial marine vessels and railroads. The recreational motorboat 

population and spatial surrogates (used to assign emissions to each) were significantly 

updated. The populations for the construction equipment category were reviewed and 

updated based upon surveys completed in the Midwest and the temporal allocation for 

agricultural sources was also updated. A new nonroad estimation model was provided by 

U.S. EPA for the 2002 analysis. 

Appendix C contains data tables and graphs of all these emissions. 

4.3 Emission Projections

In consultation with U.S. EPA and other stakeholders, IDEM selected the year 2022 as the 

maintenance year for this redesignation request. This document contains projected emission 

inventories for 2015, 2020 and 2022 for the Southwestern Indiana Area. These emission 

projections were prepared by IDEM, with assistance from LADCO and the Evansville 

Metropolitan Planning Organization. The projected emission inventories for 2020 and 2022 

were extrapolated from 2018 estimates developed by LADCO.

The detailed 2015, 2020 and 2022 emissions inventory for the Southwestern Indiana Area can be 

found in Appendix E. Emission trends are an important gauge for continued compliance with the 

annual standard for fine particles. Therefore, IDEM performed an initial comparison of the 

inventories for the base year of 2005, secondary validation year of 2008, interim years of 2015 

and 2020 and maintenance year of 2022 for the Southwestern Indiana Area. 

The 2005 LADCO modeling inventory was used as the basis for estimated emissions for the 

years 2008, 2015, 2020 and 2022, using LADCO’s growth factors, for all sectors except point 

sources (electrical generating units and non-electrical generating units). Point source emissions 

for 2005 and 2008 were compiled from Indiana’s annual emissions inventory databases. The 

2008 secondary validation emissions for other sectors were extrapolated from 2005 values. The 

2015 interim year emissions were interpolated based on the 2009 and 2018 LADCO modeling 

inventory, using LADCO’s growth factors, for all sectors. The 2020 interim year emissions and 

the 2022 maintenance year emissions were extrapolated from the 2018 LADCO modeling 
22 

inventory. 

Graphs 4.9, 4.10, and 4.11 visually compare 2005 (base year) and 2008 (secondary validation 

year) NOx, SO2 and direct PM2.5 county total estimated emissions with the 2015, 2020 and 2022 

projected emissions for the Southwestern Indiana Area. Mobile source emission inventories are 

further described in Section 5.0. In addition to LADCO’s estimates, point source emissions were 

projected based upon the statewide EGU NOx budgets from the Indiana NOx rule. It should be 

noted that EGU emission estimates for 2015, 2020, and 2022 were projected using the 

Department of Energy Information’s Annual Energy Outlook Supplemental tables for the year 

2018. These tables were generated for the reference case of the Annual Energy Outlook 2007 

(AEO 2007) using the National Energy Modeling System. Graphs and data tables of emissions 

from the EGU source category can be found in Appendix D. 

Graph 4.9 

Comparison of 2005, 2008, 2015, 2020 and 2022 Projected NOx Emissions 

for the Southwestern Indiana Area (With CAIR) 

‐

20,000

40,000

60,000

80,000

100,000

120,000

2005 2008 2015 2020 2022

Tons per Year

Nitrogen Oxides Year
23 

Graph 4.10 

 Comparison of 2005, 2008, 2015, 2020 and 2022 Projected SO2 Emissions 

for the Southwestern Indiana Area (With CAIR) 

Graph 4.11 

Comparison of 2005, 2008, 2015, 2020 and 2022 Projected Direct PM2.5 Emissions 

for the Southwestern Indiana Area (With CAIR) 

‐

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

2005 2008 2015 2020 2022

Tons per Year

Sulfur Dioxide Year

‐

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

2005 2008 2015 2020 2022

Tons per Year

Direct Fine Particulate Matter Year
24 

Graph 4.12 

Comparison of 2005, 2008, 2015, 2020 and 2022 Projected SO2, NOx and Direct PM2.5

Emission Trends for the Southwestern Indiana Area (With CAIR) 

NOx emissions within the Southwestern Indiana Area are projected to decline by 48% between 

2005 and 2022. Emission reduction benefits from U.S. EPA rules covering the NOx SIP Call, 

Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements, HeavyDuty Highway Engine Rule and the Nonroad Diesel Engine Rule are factored into the changes. 

Additionally, due to implementation of the NOx SIP Call across the eastern United States, NOx

and fine particle levels entering the Southwestern Indiana Area will also be decreased. SO2

emissions within the Southwestern Indiana Area are projected to decline by 74% between 2005 

and 2022. While an increase in direct PM2.5 emissions in the Southwestern Indiana Area is 

noted, this increase in emissions from 2002 to 2005 is due to previously unreported emissions 

from companies that did not submit their direct PM2.5 emissions data in 2002 but did submit 

direct PM2.5 data in the 2005 emissions inventory, from which the 2008, 2015, 2020 and 2022 

data is extrapolated. The 2015, 2020 and 2022 emission projections assume no additional 

controls will be installed. This approach over-predicts future year emissions as it is reasonable to 

assume a significant number of facilities will need to install additional controls to comply with 

CAIR and/or the proposed Transport Rule. The increase in direct PM2.5 emissions in the 

Southwestern Indiana Area is outweighed by the significant regional reductions in NOx and SO2 

that have occurred and will continue to occur in the future. 

‐

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

2005 2008 2015 2020 2022

Tons per Year

Nitrogen Oxides Sulfur Dioxide Direct Fine Particulate Matter
25 

Table 4.1 

Comparison of 2005 Estimated and 2022 Projected Emission Estimates, Southwestern 

Indiana Area (Annual-Tons) 

2005 2022 Change % Change 

NOx 99,921.66 51,884.76 -48,036.90 48.07% decrease 

SO2 365,954.11 94,626.89 -271,327.22 74.14% decrease 

Direct PM2.5 10,159.65 12,604.06 2,444.41 24.06% increase 

Table 4.2 

Comparison of 2008 Estimated and 2022 Projected Emission Estimates, Southwestern 

Indiana Area (Annual-Tons) 

2008 2022 Change % Change 

NOx 74,286.88 51,884.76 -22,402.12 30.16% decrease 

SO2 234,126.80 94,626.89 -139,499.91 59.58% decrease 

Direct PM2.5 13,045.38 12,604.06 -441.32 3.38% decrease 

4.4 Demonstration of Maintenance

Quality-assured ambient air quality data from all the monitoring sites indicate that air quality in 

the Southwestern Indiana Area met the annual NAAQS for fine particles for the three-year 

period ending in 2009. U.S. EPA’s Redesignation Guidance (Page 9) states, “A state may 

generally demonstrate maintenance of the NAAQS by either showing that future emissions of a 

pollutant or its precursors will not exceed the level of the attainment inventory, or by modeling 

to show that the future mix of sources and emissions rates will not cause a violation of the 

NAAQS.” Section 3.0 of this document shows that the Southwestern Indiana Area has in fact 

measured attainment for fine particles for the four consecutive periods ending in 2006, 2007, 

2008 and 2009. Additionally, emissions projections outlined in Section 4.0 of this document 

clearly illustrate that regional NOx and SO2 emissions in the area will continue to decline leading 

to local reductions between 2005 (base year) and 2022 (maintenance plan horizon). Section 7.0 

further discusses the implications of these emission trends and provides an analysis to support 

these conclusions. 

In Indiana, major point sources in all counties are required to submit air emissions information 

once every three years, or annually, if the NOx or SO2 potential to emit is greater than 2,500 tons 

per year in accordance with the Emission Reporting Rule, 326 IAC 2-6. IDEM prepares a new 

periodic inventory for all precursor emission sectors every three years. These precursor emission 

inventories will be prepared for 2011, 2014 and 2017, as necessary, to comply with the inventory 

reporting requirements established in the CAA. Emissions information will be compared to the 

2005 base year and the 2022 projected maintenance year inventories to assess emission trends, as 

necessary, to assure continued compliance with the annual standard for fine particles.
26 

4.5 Permanent and Enforceable Emission Reductions

Permanent and enforceable reductions of NOx and SO2 have contributed to the attainment of the 

annual standard for fine particles. Some of these reductions were due to the implementation of 

the NOx SIP Call and some were due to the application of tighter federal standards on motor 

vehicles and fuels. 

Section 6.0 identifies the emission control measures specific to the Southwestern Indiana Area, 

as well as the implementation status of each measure. 

4.6 Provisions for Future Updates 

 

As required by Section 175A(b) of the CAA, Indiana commits to submit to the Administrator, 

eight years after redesignation, an additional revision of this SIP. The revision will contain 

Indiana's plan for maintaining the national primary fine particles air quality standard for ten years 

beyond the first ten-year period after redesignation. 

5.0 MOBILE SOURCE EMISSION BUDGETS

U.S. EPA requirements outlined in 40 CFR 93.118(e)(4) stipulate that mobile source emission 

budgets for direct PM2.5 and NOx be established as part of a SIP. The mobile source emission 

budgets (MVEBs) are necessary to demonstrate conformance of transportation plans and 

improvement programs with the SIP. 

5.1 Onroad Emission Estimates

The Evansville Metropolitan Planning Organization (EMPO) is the Metropolitan Planning 

Organization (MPO) for the Evansville area. The EMPO study area contains approximately 650 

square miles in Indiana, including the City of Evansville, Vanderburgh County, Warrick County 

and a very small area of eastern Posey County. In Kentucky, the study area encompasses 

approximately 440 square miles which includes the City of Henderson and Henderson County. 

Additionally, the Indiana Department of Transportation (INDOT) and the EMPO have executed 

an agreement for the EMPO to provide planning assistance in rural Gibson County. 

The EMPO maintains a travel demand forecasting model that was updated and improved in 

2006. The model incorporates the road network of a five county area, which includes the Indiana 

counties of Vanderburgh, Warrick, Gibson and Posey, and Henderson County in Kentucky. 

Incorporated into the travel demand model is a post-processor that uses the U.S. EPA-required 

emissions estimation model MOBILE6.2 to calculate total emissions. 

 

The EMPO travel demand model is used to simulate the traffic in the area and to predict what 

traffic would be in future years given growth expectations. The model is used mostly to identify 

where travel capacity will be needed and to determine the infrastructure requirements necessary 

to meet that need. It is also used to support the calculation of mobile source emissions. The 

travel demand forecasting model is used to predict the total daily vehicle miles traveled (VMT) 

and MOBILE6.2 is used to produce emission factors to calculate the emissions per mile. The 
27 

product of these two outputs, once combined, is the total amount of pollution emitted by onroad 

vehicles for the particular analyzed area. Dubois County, Ohio Township in Spencer County and 

Washington Township in Pike County are Indiana areas included in U.S. EPA’s nonattainment 

designations for fine particles that do not fall under the jurisdiction of EMPO. In cases such as 

this, INDOT uses Highway Performance Monitoring System (HMPS) baseline data to estimate 

and project mobile source emissions. This is a national program that requires state Departments 

of Transportation to collect traffic counts throughout the state on a regular basis under a certain 

regulated method. This HPMS data was collected and provided by INDOT and was used for 

these three areas beyond Evansville MPO’s jurisdiction. 

5.2 Overview

Broadly described, MOBILE6.2 is used to generate “emission factors,” which are the average 

emissions per mile (grams/mile) for direct PM2.5 and PM2.5 precursors, including NOx and SO2. 

There are numerous variables that can affect the emission factors. The vehicle-fleet (vehicles on 

the road) age and the vehicle types have a major affect on the emission factors. The facility-type 

the vehicles are traveling on (MOBILE6.2 facility types are Freeway, Arterial, Local and Ramp) 

and the vehicle speeds also affect the emission factor values. Meteorological factors such as air 

temperature and humidity affect the emission factors, as does fuel type, such as low Reid Vapor 

Pressure gasoline. These data are estimated using the best available data to generate emission 

factors for direct PM2.5 and PM2.5 precursors, including NOx and SO2. After emission factors are 

generated, the emission factor(s) must be multiplied by the VMT to determine the quantity of 

vehicle-related emissions. This information derives from the travel demand model (TDM). 

It should be noted that each year analyzed will have different emission factors, volumes, speeds 

and likely some additional links such as roads. MOBILE6.2 input and output files can all be 

found in Appendix F. 

5.3 Analysis Years

The travel demand model contains road networks that are time specific. The EMPO has modeled 

the years 2002, 2010, 2015, 2025 and 2035. Information, including emissions, has also been 

interpolated from 2002 and 2010 for the years 2005 and 2008 and from 2015 and 2025 for the 

years 2020 and 2022. This Redesignation Petition provides emissions inventory estimates for 

2002, 2005, 2010, 2020 and 2022 to meet the requirements specified by the CAA and the U.S. 

EPA. The emissions estimates outlined in Section 4.0 of this document include the 2005, 2010, 

2020 and 2022 mobile source emissions data referenced in Table 5.1. 

5.4 Emission Estimations

Table 5.1 outlines predicted onroad emissions estimates for the entire nonattainment area for the 

years 2005 (base year), 2008 (attainment year), 2015 (interim year), 2020 and 2022 (Horizon 

Year). The following emission estimates are based on the TDM network runs for the years 2005, 

2008, 2015, 2020 and 2022. 
28 

Table 5.1 

Emission Estimations for Onroad Mobile Sources 

for the Southwestern Indiana PM2.5 Nonattainment Area 

 2005 2008 2015 2020 2022 

Direct PM2.5 (tons/year) 117.67 91.59 54.33 50.48 48.93 

NOx (tons/year) 6,528.04 5,018.06 2,503.19 1,929.38 1,699.86 

5.5 Mobile Source Emission Budgets

Table 5.2 contains the MVEBs for the entire nonattainment area for the years 2015 and 2022. 

Table 5.2 

Mobile Source Emission Budgets 

for the Southwestern Indiana PM2.5 Nonattainment Area 

2015 2022 

PM2.5 (tons/year) 57.05 53.83 

NOx (tons/year) 2,628.35 1,869.84 

Consistent with the federal implementation rule for fine particles, IDEM does not consider 

mobile source SO2 emissions to be a significant contributor to fine particles for this 

nonattainment area, as SO2 constitutes less than one percent (<1%) of the area’s total 

anthropogenic emissions for the years 2005, 2008, 2015, 2020 or 2022. 

This document creates an interim year budget for 2015 and a horizon year budget for 2022 for 

the Southwestern Indiana Area. These budgets are based on the 2005 onroad emission inventory 

used to support photochemical modeling for the same year, and has incorporated an appropriate 

safety margin as described below. 

In an effort to accommodate future variations in TDMs and VMT forecast when no change to the 

network is planned, IDEM consulted with the interagency consultation group, including U.S. 

EPA Region V, to determine a reasonable approach to address this variation. The interagency 

consultation group approved a five (5%) safety margin for PM2.5 and NOx mobile source 

emissions estimates for the year 2015 and a ten percent (10%) safety margin for PM2.5 and NOx 

mobile source emissions estimates for the year 2022. 

The safety margins are appropriate because: 1) there is an acknowledged potential variation in 

VMT forecast and potential estimated mobile source emissions due to expected modifications to 

TDM and mobile emissions models; and 2) the total decrease in emissions from all sources is 

sufficient to accommodate the safety margin allocations detailed above to mobile sources while 

still continuing to maintain total emissions in the Southwestern Indiana nonattainment area well 

below the 2008 attainment level of emissions. These safety margins were calculated by adding a 

straight-line percentage to the mobile source emission estimates for the years 2015 and 2022. 

Safety margin, as defined by the conformity rule, looks at the total emissions from all sources in 
29 

the nonattainment area. The resulting 2015 and 2022 MVEBs for PM2.5 and NOx emissions 

remain well below the 2005 base year emissions referenced in Table 5.1. 

In summary, the mobile budget safety margin allocation translates into: 

 An allocation of 2.72 tons/year for PM2.5 and 125.16 tons/year for NOx for 2015. 

 An allocation of 4.90 tons/year for PM2.5 and 169.98 tons/year for NOx for 2022. 

The rule at 40 CFR 93.101 defines safety margin as the amount by which the total projected 

emissions from all sources of a given pollutant are less than the total emissions that would satisfy 

the applicable requirement for reasonable further progress, attainment or maintenance. When 

compared to the overall safety margin as defined by 40 CFR 93.101, it is evident this allocation 

to mobile sources is significantly below the total safety margin for all sources in the 

Southwestern Indiana Area as detailed in Table 4.1. 

While IDEM believes that this is sufficient to support the requested increase, IDEM and its 

partners will be conducting additional air quality modeling which will include the adjusted 

mobile emissions, as well as any additional corrections and modifications that may be necessary 

due to the constant review and evaluation of the model inputs. 

5.6 Commitment to Amend Motor Vehicle Emission Budgets Using MOVES

On March 2, 2010, U.S. EPA published a Notice of Availability for the Motor Vehicle Emission 

Simulator (MOVES) model. Indiana is committed to submitting a revision to the MOBILE6.2 

developed MVEBs using the MOVES model as soon as possible and well in advance of the 

March 2, 2012, expiration of the transportation conformity “grace period.” IDEM recognizes 

that U.S. EPA will allow the MOBILE6.2 budgets to be replaced through an adequacy notice in 

place of a full publication to the Federal Register. 

 

All methodologies, latest planning assumptions, margins of safety and MOVES model 

commitments were determined appropriate through the interagency consultation 

process. 

6.0 CONTROL MEASURES AND REGULATIONS

This section provides specific information on the control measures that have been or will be 

implemented in the Southwestern Indiana Area, including CAA requirements and additional state 

or local measures implemented beyond CAA requirements. 

6.1 Reasonably Available Control Technology (RACT)

 As required by Section 172 of the CAA, in the mid-1990s, Indiana promulgated rules requiring 

RACT for emissions of VOCs. There were no specific rules required by the CAA, such as 

RACT for existing sources, beyond statewide rules. Statewide RACT rules have applied to all 
30 

new sources locating in Indiana since that time. The Indiana rules are found in 326 IAC 8. The 

following is a listing of applicable rules: 

 326 IAC 8-1-6 BACT for Non-Specific Sources 

326 IAC 8-2 Surface Coating Emission Limitations 

326 IAC 8-3 Solvent Degreasing Operations 

326 IAC 8-4 Petroleum Sources 

326 IAC 8-5 Miscellaneous Operation 

326 IAC 8-6 Organic Solvent Emission Limitations 

Since the Southwestern Indiana Area attained the annual NAAQS for fine particles prior to an 

Attainment SIP or RACT SIP being due, and since the Implementation Rule for fine particles 

stipulates that states are only required to draft and implement RACT rules for the precursor 

emission reductions necessary to attain the standard, no further RACT rules are required for this 

area. These Indiana rules are CAA requirements already in the SIP and provide secondary 

benefits for PM2.5. 

6.2 Implementation of Past SIP Revisions

The area was designated nonattainment for the annual standard for fine particles in 2003 and the 

area attained the standard well in advance of its attainment deadline of 2010. As a result, Indiana 

is no longer required to develop and submit an Attainment SIP or RACT SIP for this area under 

the annual NAAQS for fine particles. 

6.3 Nitrogen Oxides (NOx) Rule

The U.S. EPA NOx SIP Call required twenty-two states to adopt rules that would result in 

significant emission reductions from large EGUs, industrial boilers and cement kilns in the 

eastern United States. Indiana adopted this rule in 2001. Beginning in 2004, this rule accounts 

for a reduction of approximately thirty-one percent (31%) of all NOx emissions statewide 

compared to previous uncontrolled years. 

Twenty-one other states have also adopted these rules. The result is that significant reductions 

have occurred regionally and within the nonattainment area because of the number of affected 

units within the region. From Graph 4.7 and Figures 4.1 and 4.2, it can be seen that emissions 

covered by this program have been generally trending downward since 1999. Table 6.1, 

compiled from data taken from the U.S. EPA Clean Air Markets Web site, quantifies the gradual 

NOx reductions that have occurred in Indiana as a result of Title IV (Acid Rain) of the CAA and 

the NOx SIP Call Rule. The NOx SIP Call cap stayed in place through 2008, at which time the 

caps in the CAIR program superseded it. Since CAIR is a regional cap and trade program, it 

cannot be predicted at this time what effect this will have on EGU units located in the 

nonattainment area or other upwind counties. 

Further, U.S. EPA published Phase II of the NOx SIP Call that establishes a budget for large 

(emissions of greater than 1 ton per day) stationary internal combustion engines. In Indiana, the 

rule decreases emissions statewide from natural gas compressor stations by 4,263 tons during the 

ozone season (May through October). The Indiana Phase II NOx SIP Call Rule became effective 

February 26, 2006 and implementation began in 2007. 
31 

Table 6.1 

Trends in EGU NOx Emissions Statewide in Indiana 

Year NOx Emissions (tons /year) 

1999 347,216.5 

2000 334,522.1 

2001 315,419.7 

2002 281,146.1 

2003 260,980.0 

2004 224,311.3 

2005 207,981.6 

2006 202,728.0 

2007 196,553.1 

2008 196,134.5 

2009 110,968.9 

Budget 2009-2014 108,935 

Budget 2015 and later 90,779 

6.4 Measures Beyond Clean Air Act SIP Requirements

Reductions in fine particles precursor emissions have occurred, or are anticipated to occur, as a 

result of local and federal programs. These additional control measures include: 

Tier 2 Vehicles Standards8

Federal Tier 2 motor vehicle standards require all passenger vehicles in a manufacturer’s fleet, 

including light-duty trucks and sport utility vehicles (SUVs), to meet an average standard of 0.07 

grams of NOx per mile. Implementation began in 2004 and was completed in 2007. The Tier 2 

standards also cover passenger vehicles over 8,500 pounds gross vehicle weight rating (larger 

pickup trucks and SUVs), which are not covered by the current Tier 1 standards. For these 

vehicles, the standards were phased in beginning in 2008, with full compliance in 2009. The 

new standards require vehicles to be 77% to 95% cleaner than those on the road prior to the 

program. The Tier 2 standards also reduced the sulfur content of gasoline to 30 parts per million 

(ppm) beginning in January 2006. Most gasoline sold in Indiana prior to January 2006 had a 

sulfur content of about 500 ppm. Sulfur occurs naturally in gasoline, but interferes with the 

operation of catalytic converters on vehicles resulting in higher NOx emissions. Lower sulfur 

gasoline is necessary to achieve the Tier 2 vehicle emissions standards. 

Heavy-Duty Gasoline and Diesel Highway Vehicle Standards9

New U.S. EPA standards designed to reduce NOx and VOC emissions from heavy-duty gasoline 

 

8 http://www.epa.gov/fedrgstr/EPA-AIR/2000/February/Day-10/a19a.htm

9 http://www.epa.gov/fedrgstr/EPA-AIR/1997/October/Day-21/a27494.htm
32 

and diesel highway vehicles took effect in 2004. A second phase of standards and testing 

procedures, that began in 2007, reduced PM2.5 emissions from heavy-duty highway engines and 

also reduced highway diesel fuel sulfur content to 15 ppm since the sulfur can damage emissions 

control devices. The total program is expected to achieve a 90% reduction in direct PM2.5

emissions and a 95% reduction in NOx emissions for these new engines using low sulfur diesel, 

compared to existing engines using higher sulfur content diesel. There will also be SO2

reductions from these rules. The U.S. EPA has not quantified the expected reductions. 

Large Nonroad Diesel Engine Standards10

In May 2004, U.S. EPA promulgated new rules for large nonroad diesel engines, such as those 

used in construction, agricultural, and industrial equipment, to be phased in between 2008 and 

2014. The nonroad diesel rules also reduce the allowable sulfur in nonroad diesel fuel by over 

99%. Prior to 2006, nonroad diesel fuel averaged approximately 3,400 ppm sulfur. This rule 

limited nonroad diesel sulfur content to 500 ppm by 2006 with a further reduction to 15 ppm by 

2010. The combined engine and fuel rules will reduce NOx and PM emissions from large 

nonroad diesel engines by over 90%, compared to current nonroad engines using higher sulfur 

content diesel. 

Nonroad Spark-Ignition Engines and Recreational Engines Standards

This new standard, effective in July 2003, regulates NOx, VOCs, and carbon monoxide (CO) for 

groups of previously unregulated nonroad engines. The new standard applies to all new engines 

sold in the United States and imported after the standards went into effect. The standard applies 

to large spark-ignition engines (forklifts and airport ground service equipment), recreational 

vehicles (off-highway motorcycles and all-terrain vehicles) and recreational marine diesel 

engines. The regulation varies based upon the type of engine and vehicle. 

The large spark-ignition engines contribute to ozone formation and ambient CO and PM levels in 

urban areas. Tier 1 of this standard was implemented in 2004 and Tier 2 started in 2007. Like 

the large spark-ignition engines, recreational vehicles contribute to ozone and fine particles 

formation and ambient CO and PM levels. For Model Year 2006 off-highway motorcycles and 

all-terrain vehicles, at least 50% of a manufacturer’s fleet was required to meet the new exhaust 

emissions standard and 100% of the fleet was required to meet the standards in 2007. 

Recreational marine diesel engines over 37 kilowatts are used in yachts, cruisers and other types 

of pleasure craft. Recreational marine engines contribute to ozone formation and PM levels, 

especially surrounding marinas. 

When all of the nonroad spark-ignition engines and recreational engine standards are fully 

implemented, an overall 72% reduction in VOC, 80% reduction in NOx, and 56% reduction in 

CO emissions are expected by 2020. 

 

10 http://www.epa.gov/fedrgstr/EPA-AIR/1998/October/Day-23/a24836.htm
33 

Reciprocating Internal Combustion Engine Standards11

This new standard, effective in May 2010, regulates air toxics emissions from existing diesel 

powered stationary reciprocating internal combustion engines that meet specific site rating, age 

and size criteria. These engines are typically used at industrial facilities (e.g. power, chemical 

and manufacturing plants) to generate electricity for compressors and pumps and to produce 

electricity to pump water for flood and fire control during emergencies. 

The standard applies to stationary diesel engines: (1) used at area sources of air toxics emissions 

and constructed or reconstructed before June 12, 2006; (2) used at major sources of air toxics 

emissions, having a site rating of less than or equal to 500 horsepower, and constructed or 

reconstructed before June 12, 2006; and, (3) used at major sources of air toxics for nonemergency purposes, having a site rating of greater than 500 horsepower, and constructed or 

reconstructed before December 19, 2002. 

Operators of existing engines will be required to: (1) install emissions control equipment that 

would limit air toxics up to 70% for stationary non-emergency engines with a site rating greater 

than 300 horsepower; (2) perform emissions tests to demonstrate engine performance and 

compliance with rule requirements; and, (3) burn ultra-low sulfur fuel in station non-emergency 

engines with a site rating greater than 300 horsepower. 

When all of the reciprocating internal combustion engine standards are fully implemented in 

2013, U.S. EPA estimates that emissions from these engines will reduce air toxics by 

approximately 1,000 tons per year (tpy), PM2.5 by 2,800 tpy, CO by 14,000 tpy and VOCs by 

27,000 tpy. 

Category 3 Marine Diesel Engine Standards12

This new standard, effective in June 2010, promulgates more stringent exhaust emission 

standards for new large marine diesel engines with per-cylinder displacement at or above 30 

liters (commonly referred to as Category 3 compression-ignition marine engines) as part of a 

coordinated strategy to address emissions from all ships that affect U.S. air quality. These 

emission standards are equivalent to those adopted in the amendments to Annex VI to the 

International Convention for the Prevention of Pollution from Ships (MARPOL Annex VI). The 

emission standards apply in two stages—near-term standards for newly built engines will apply 

beginning in 2011; long-term standards requiring an 80% reduction in NOX emissions will begin 

in 2016. 

U.S. EPA is adopting changes to the diesel fuel program to allow for the production and sale of 

diesel fuel with up to 1,000 ppm sulfur for use in Category 3 marine vessels. The regulations 

generally forbid production and sale of fuels with more than 1,000 ppm sulfur for use in most 

U.S. waters, unless operators achieve equivalent emission reductions in other ways.

U.S. EPA is also adopting provisions to apply some emission and fuel standards to foreign-

 

11 http://www.epa.gov/ttn/atw/rice/fr03mr10.pdf

12 http://www.regulations.gov/search/Regs/home.html#documentDetail?R=0900006480ae43a6
34 

flagged and in-use vessels that are covered by MARPOL Annex VI. 

When this strategy is fully implemented in 2030, U.S. EPA estimates that NOx and PM 

emissions in the U.S. will be reduced by approximately 1.2 million tpy and 143,000 tpy, 

respectively. 

Clean Air Interstate Rule (CAIR)

On May 12, 2005, the U.S. EPA promulgated the “Rule to Reduce Interstate Transport of Fine 

Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program; 

Revisions to the NOx SIP Call”; Final Rule. This rule established the requirement for states to 

adopt rules limiting the emissions of NOx and SO2 and provided a model rule for the states to use 

in developing their rules to meet federal requirements. The purpose of CAIR was to reduce 

interstate transport of precursors of fine particles and ozone. 

CAIR applied to: (1) any stationary, fossil fuel-fired boiler or stationary, fossil fuel-fired 

combustion turbine, a generator with nameplate capacity of more than 25 megawatt electrical 

(MWe) producing electricity for sale; and (2) for a unit that qualifies as a cogeneration unit 

during the 12-month period starting on the date that the unit first produces electricity and 

continues to qualify as a cogeneration unit, a cogeneration unit serving at any time a generator 

with a nameplate capacity of more than 25 MWe and supplying in any calendar year more than 

one-third of the unit’s potential electric output capacity or 219,000 MWh (megawatt hours), 

whichever is greater to any utility power distribution system for sale. 

This rule provided annual state caps for NOx and SO2 in two phases, with the Phase I caps for 

NOx and SO2 starting in 2009 and 2010, respectively. Phase II caps become effective in 2015. 

The U.S. EPA allows the caps to be met through a cap and trade program if a state chooses to 

participate in the program. 

In response to U.S. EPA’s rulemaking, IDEM adopted a state rule in 2006 based on the model 

federal rule. IDEM’s rule includes an annual and seasonal NOx trading program and an annual 

SO2 trading program. This rule required compliance effective January 1, 2009. 

SO2 emissions from power plants in the 28 eastern states and the District of Columbia covered 

by CAIR will be cut by 4.3 million tons by 2009 and reduced by an additional 5.4 million tons in 

2015. NOx emissions will be cut by 1.7 million tons by 2009 and reduced by an additional 1.3 

million tons in 2015. The D.C. Circuit court’s vacatur of CAIR in July 2008 and subsequent 

remand without vacatur of CAIR in December 2008 directs U.S. EPA to revise/replace CAIR in 

order to properly address the deficiencies outlined by the court. 

Since the court’s opinion made it clear that CAIR is deficient and must be revised/replaced, the 

program cannot be defined as permanent and enforceable for SIP purposes. On July 6, 2010, 

U.S. EPA proposed the Clean Air Transport Rule to replace CAIR. The Transport Rule will 

result in even further benefits above and beyond CAIR than what is assumed within the emission 

inventories and modeling. 
35 

Together, these rules will substantially reduce local and regional sources of fine particle 

precursors. The modeling analyses discussed in Section 7.0 include these rules and show the 

reductions in annual fine particle concentrations expected to result from the implementation of 

these rules. 

6.5 Controls to Remain in Effect

Indiana commits to maintain the control measures listed above after redesignation, or submit to 

U.S. EPA, as a SIP revision, any changes to its rules or emission limits applicable to NOx, SO2 or 

direct PM2.5 sources as required for maintenance of the annual standard for fine particles in the 

Southwestern Indiana nonattainment area. 

Indiana, through IDEM’s Office of Air Quality (OAQ) and its Compliance and Enforcement 

Branch, has the legal authority and necessary resources to actively enforce any violations of its 

rules or permit provisions. After redesignation, it intends to continue enforcing all rules that 

relate to the emission of fine particles and fine particles precursors in the Southwestern Indiana 

Area. 

6.6 New Source Review Provisions

Indiana has a long standing and fully implemented New Source Review (NSR) program that is 

outlined in rule at 326 IAC 2. The rule includes provisions for the Prevention of Significant 

Deterioration (PSD) permitting program in 326 IAC 2-2. Indiana's PSD program was 

conditionally approved on March 3, 2003 (68 FR 9892) and received final approval on May 20, 

2004 (69 FR 29071) by U.S. EPA as part of the SIP. 

Any facility that is not listed in the 2005 emission inventory, or for which credit through the 

shutdown or curtailment was taken in demonstrating attainment, will not be allowed to construct, 

reopen, modify, or reconstruct without meeting all applicable permit rule requirements. The 

review process will be identical to that used for new sources. Once the area is redesignated, 

OAQ will implement NSR through the PSD program, which requires an air quality analysis to 

evaluate whether the new source will threaten the NAAQS. 

7.0 MODELING AND METEOROLOGY 

Although U.S. EPA’s Redesignation Guidance does not require modeling for nonattainment 

areas seeking redesignation, extensive modeling has been performed covering the Southwestern 

Indiana region to determine the effect of national emission control strategies on fine particle 

levels. These modeling analyses determined that the Southwestern Indiana Area, including 

Vanderburgh, Warrick, and Dubois counties and Montgomery Township in Gibson County, Ohio 

Township in Spencer County and Washington Township in Pike County, is significantly 

impacted by regional transport of fine particles and its precursors, and that regional SO2 and NOx

reductions are an effective way to attain the annual standard for fine particles in this area. Future 

year modeled annual fine particle concentrations are expected to be reduced by 2% to 9% from 

baseline design values. Examples of these modeling analyses are described in this section. 
36 

7.1 Summary of Modeling Results to Support Rulemakings

U.S. EPA Modeling for Transport Rule 201013

U.S. EPA performed modeling to support the emission reductions associated with the Proposed 

Transport Rule. U.S. EPA used the Comprehensive Air Quality Model with Extension (CAMx 

Version 5), applied to the 2005 meteorology, as processed by the Mesoscale Model (MM5), 

Version 3.7.4. Emissions input into CAMx included SO2, NOx, VOCs, NH3 and direct PM2.5 for 

2005. The modeling was based on the annual fine particle design values calculated from 2003 

through 2005, 2004 through 2006, and 2005 through 2007. Future year modeling was 

conducted, which included the Southwestern Indiana Area, and the future year design values for 

2012 and 2014 were evaluated for attainment of the annual NAAQS for fine particles of 15 

μg/m3, as shown in Table 7.1. Fine particle concentrations are accounted for by modeling both 

the base future year emissions and then the emission reductions associated with the Transport 

Rule. U.S. EPA found model performance met suggested benchmark performance goals within 

or close to the ranges found in other comparable modeling applications.

Table 7.1 

Transport Rule Modeling Results from U.S. EPA – 2010 

County Monitor ID 

Design 

Value 

2003-2007 

(μg/m3)

Future 

Design 

Value 

2012 Base 

(μg/m3)

Future 

Design 

Value 

2014 Base 

(μg/m3)

Vanderburgh Co. 18-163-0006 14.69 14.55 14.02 

Vanderburgh Co. 18-163-0012 14.82 14.64 14.09 

Vanderburgh Co. 18-163-0016 14.99 14.84 14.30 

Dubois Co. 18-037-2001 15.18 15.07 14.50 

Knox Co. 18-083-0004 14.03 13.94 13.33 

Spencer Co. 18-147-0009 14.32 14.21 13.65 

Daviess Co. – KY 21-059-0005 14.10 14.14 13.59 

Modeling results show that the base future year modeling with emission reductions from the 

Transport Rule accounts for 0.1 to 0.2 μg/m3

 decreases in concentrations for 2012 and 0.5 to 0.7 

μg/m3 decreases in concentrations for 2014 in the Southwestern Indiana Area. 

While results of U.S.EPA’s Transport Rule modeling show modeled concentrations above the 

standard using base case emissions at the Dubois Co. PM2.5 monitoring site, it should be noted 

that the base year design value used by U.S. EPA was taken from 2003 through 2007 and is 

higher than current 2005 through 2009 design values in the area. Graph 7.1 shows the downward 

trend of the design values from 2000 through 2009 for the PM2.5 monitors in the Southwestern 

Indiana Area. The resulting decrease of the 2003 through 2007 design value to the 2005 through 

2009 design value at the Dubois Co. PM2.5 monitor is 1.3 μg/m3

 with all the area’s PM2.5

 

13 http://www.epa.gov/airquality/transport/pdfs/TR_AQModeling_TSD.pdf 
37 

monitors design values decreasing from 0.9 μg/m3 to 1.3 μg/m3. Therefore, U.S.EPA’s 

Transport Rule modeling, using current 2005 through 2009 design values, shows all modeled 

concentrations below the annual fine particles standard of 15.0 μg/m3

. 

Graph 7.1 

PM2.5 Design Value Trends for the Southwestern Indiana Area - 2000 through 2009 

Results of the U.S. Transport Rule modeling show that all Southwestern Indiana counties will 

attain the annual fine particle NAAQS in 2012 with modeled impacts reduced by 1% to 2%, and 

remain below 15 μg/m3. With further reductions projected in the U.S. Transport Rule for 2014, 

all design values decrease by 4% to 5% and continue to attain the annual NAAQS for fine 

particles. 

LADCO Modeling for Clean Air Interstate Rule (CAIR)

LADCO conducted modeling to determine the impact of CAIR in the Midwest. LADCO’s 

modeling used the CAMx model applied to the year 2005 meteorology, as processed by the 

MM5. Emissions input into CAMx included SO2, NOx, VOCs, NH3 and direct PM2.5 for 2005. 

The modeling was based on 2003 through 2007 design values. Future year modeling for 2012 

and 2018 was conducted and the future year design values were determined without the emission 

reductions associated with CAIR (Round 6), as shown in Table 7.2. The U.S. Transport Rule is 

expected to provide reductions above and beyond CAIR. 

12.0

13.0

14.0

15.0

16.0

17.0

18.0

00‐04 01‐05 02‐06 03‐07 04‐08 05‐09

Concentrations(ug/m3)

Design Value Year

Civic Center W. Mill Rd. U of Evansville Spencer Co.

Dubois Co. Knox Co. Annual Standard
38 

Table 7.2 

LADCO’s Round 6 Modeling Results 

(Without the Clean Air Interstate Rule emission reductions) 

Monitor ID Monitor 

Name County 

Design Value

2003-2007 

(μg/m3) 

Base-case 

2012 

(μg/m3) 

Base-case

2018 

(μg/m3) 

18-163-0006 Civic Center Vanderburgh 14.7 13.9 13.7 

18-163-0012 W. Mill Rd. Vanderburgh 14.8 13.9 13.6 

18-163-0016 Univ. of Evansville Vanderburgh 15.0 14.2 14.0 

18-147-0009 Dale Spencer 14.3 13.2 13.0 

18-037-2001 Jasper Post Office Dubois 15.2 14.0 13.8 

18-037-0004 Sports Complex Dubois 13.9 12.8 12.6 

18-037-0005 Jasper Golf Course Dubois 14.0 12.9 12.8 

18-083-0004 SW Purdue Ag. Knox 14.0 13.1 12.9 

21-059-0005 Owensboro Daviess - KY 14.4 13.8 13.6 

21-059-0014 Wesleyan College Daviess - KY 13.0 12.6 12.5 

Results of the LADCO Round 6 modeling show that all Southwestern Indiana counties will 

attain the annual NAAQS for fine particles by 2012. As shown in Table 7.2, future year modeled 

annual fine particle concentrations for 2012 will be 3% to 8% lower than baseline annual fine 

particle design values and 4% to 9% lower in 2018 and will continue to decrease thereafter. 
39 

Graph 7.2 

Modeling Results for Southwestern Indiana PM2.5 Monitors - 2009, 2012, and 2018 

7.2 LADCO’s Round 5 Speciated Modeled Attainment Test Results

The Speciated Modeled Attainment Test (SMAT) is the attainment test for annual fine particles. 

To determine the future year annual fine particle concentrations, speciated data is calculated. 

The different species that were modeled and are associated with fine particles include sulfates, 

nitrates, organic carbon, elemental carbon, ammonium, particle bound water, “other” primary 

inorganic fine particles and passively collected mass. The SMAT results from LADCO’s Round 

5 modeling are listed below. Percent ranges of the model results from the six fine particle 

monitors in Southwestern Indiana were broken down into these speciated constituents of fine 

particles emissions. The percent decrease from the observed speciated data in 2005 to the future 

year modeled results for 2009 are listed in Table 7.3.
40 

Table 7.3 

LADCO’s Round 5 SMAT Modeling Results for Southwestern Indiana 

(Percent decrease from observed to modeled concentrations) 

Species of PM2.5 2009 

Sulfates 24% - 29% 

Nitrates 0% - 8% 

Organic Carbon 0% - 4% 

Elemental Carbon 0% - 20% 

Ammonium 16% - 26% 

Particle Bound Water 19% - 31% 

The results show that sulfate, ammonium, and particle bound water concentration decreases are 

projected to occur by at least 16% in 2009. Lesser nitrate reductions are projected to occur, up to 

8%, with organic carbon reductions occurring up to 4%. LADCO modeling shows good 

performance for sulfates and elemental carbon predicted baseline concentrations, slight overprediction for nitrate concentrations and under-predictions of organic carbon concentrations. 

Overall, model performance is adequate for SIP planning and gives a good idea of the effects of 

emissions reductions from national emission control measures on the Southwestern Indiana Area. 

7.3 LADCO’s Round 5 Particulate Source Apportionment Results

Particulate Source Apportionment (PSAT) modeling was conducted by LADCO. The results of 

the PSAT Round 5 modeling shows the regional contributions by emission sectors on each 

monitor that was modeled. Chart 7.1 shows the PSAT modeling results for the Jasper, Dubois 

County fine particles monitor; Civic Center, West Mill Road and University of Evansville fine 

particles monitors in Vanderburgh County; Dale, Spencer County fine particles monitor; and the 

Knox County fine particles monitor. Indiana was the biggest regional contributor to the Jasper, 

West Mill Road and the Dale fine particle monitors. Kentucky was the biggest regional 

contributor to the Civic Center and University of Evansville fine particle monitors. Illinois was 

the biggest regional contributor to the Knox County fine particles monitor. The PSAT Round 5 

modeling results show the majority of Indiana’s emission sector contributions to fine particle 

concentrations come from EGUs, ammonium emission sources, off-road (including marine, 

aircraft, and railroad) and non-EGU sources. These results are considered to be representative of 

the entire Southwestern Indiana Area as EGU, ammonium and non-EGU emissions impact the 

entire area. 
41 

Chart 7.1 

Regional/Emission Sector PSAT Results 

 Jasper, Dubois Co. Civic Center, Evansville 

West Mill Road, Evansville University of Evansville 

Dale, Spencer Co. Knox Co. 

 
42 

The following pie charts depict the species contributions to fine particle concentrations at the 

Southwestern Indiana monitors. The pie charts include both the observed 2005 contributions and 

2009 modeled contributions for each monitor. Since the monitors are in close proximity of each 

other, results are fairly similar in the distribution of species concentrations among the monitors. 

Charts 7.2 and 7.3 cover the fine particle monitors in the Southwestern Indiana Area with the 

highest monitored concentrations that are used to determine compliance with the annual NAAQS 

for fine particles. 

Chart 7.2 

Pie Charts - Species Modeled Contributions to Jasper, Dubois Co. PM2.5 Monitor 

(Observed Concentrations = 14.8 μg/m3) (Modeled Concentrations =14.0 μg/m3) 

Chart 7.3 

Pie Charts - Species Modeled Contributions to University of Evansville PM2.5 Monitor 

(Observed Concentrations = 15.4 μg/m3

) (Modeled Concentrations =14.1 μg/m3) 

Results of the Round 5 PSAT modeling for Southwestern Indiana fine particle monitors show the 

highest pollutant contributors to base-case and future year fine particle concentrations are sulfate, 

organic carbon, ammonium and nitrate. Future year modeling shows decreases in sulfates (due 

to the emission reductions from CAIR) and ammonium. The future year modeling did show 

slight increases in organic carbon and nitrates from the base-case modeled concentrations. 

 

Observed 2005 Contributions at Jasper PM2.5 Monitor

so4

36%

no3

9% oc

21%

ec

3%

soil

2%

nh4

14%

pbw

12%

blan

3%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions at Jasper PM2.5 Monitor

so4

31%

no3

10%

oc

25%

ec

3%

soil

3%

nh4

14%

pbw

10%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

Observed 2005 Contributions at University of Evansville PM2.5 Monitor

so4

32%

no3

11%

oc

23%

ec

4%

soil

3%

nh4

14%

pbw

10%

blan

3%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions at University of Evansville PM2.5 Monitor

so4

27%

no3

12%

oc

26%

ec

4%

soil

4%

nh4

13%

pbw

10%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan
43 

7.4 Summary of Existing Modeling Results

U.S. EPA and LADCO modeling for future year design values have consistently shown that 

existing national emission control measures will bring the Southwestern Indiana counties into 

attainment of the annual NAAQS for fine particles. Emission control measures to be 

implemented in the next several years will provide even greater assurance that air quality will 

continue to meet the standard into the future. Modeling support for CAIR has shown that future 

year design values for the Southwestern Indiana counties will continue to attain the annual 

standard for fine particles with modeled future year design values below 15 μg/m3

. U.S. EPA 

future year modeling of national emission control strategies showed the Southwestern Indiana 

counties will attain the annual NAAQS for fine particles without additional national emission 

controls. Future national and local emission control strategies will ensure that the Southwestern 

Indiana fine particle nonattainment area will maintain lower fine particle concentrations with an 

increasing margin of safety. 

7.5 Meteorological Analysis for Southwestern Indiana

Meteorological conditions are one of the most important factors that influence development and 

transport of fine particles. Stagnant surface conditions during any time of the year and upper air 

ridging provides conducive conditions for development and transport of fine particles. 

Ultimately, passage of surface cold fronts with a clean air mass change will lower fine particles 

readings in the Southwestern Indiana Area. 

7.6 Surface Air Conditions Present during High Fine Particles Concentrations Days

Higher concentrations of fine particles tend to correlate with warmer temperatures and lighter 

wind speeds, although high fine particle episodes can occur in the summer or winter. It should 

be noted that higher annual fine particle concentrations are driven by individual days with higher 

fine particle concentrations throughout the monitored year. Therefore, it is difficult to attribute 

higher fine particle concentrations to annualized meteorological rankings. Review of several of 

the higher fine particle concentration episodes over the past few years show conditions were hot 

in the summer with temperatures in the middle 80o

s Fahrenheit or higher and average wind 

speeds were fairly light. Fall and winter days with higher fine particles concentrations had near 

normal temperatures but wind speeds were very light. 

7.7 Upper Air Conditions Present during High Fine Particles Concentrations Days

Upper air ridges and more stagnant surface wind conditions predominately affect development 

and build up of fine particles. Slow moving upper air ridges can effectively suppress mixing 

within the many levels of the atmosphere and cause pollutants to build up over time. Inversions 

or increases in temperature with a rise in altitude will prevent mixing with air from the upper 

atmosphere. These conditions can occur at any time of the year and are evident in elevated fine 

particles episodes in spring, summer, fall and winter months. Review of surface and upper air 

features of higher fine particle concentration days showed stagnant surface conditions and upper 

air ridges existed on those days and helped in the buildup of fine particle concentrations. 
44 

7.8 Analyses of Atmospheric Conditions during High Fine Particles Concentration Days

Analyses have been conducted to determine the atmospheric conditions that are most prevalent 

during higher fine particle concentration days in Indiana. LADCO applied a Classification and 

Regression Tree (CART) analysis to data from Indiana that correlated different levels of fine 

particle concentrations to meteorological conditions from 1999 through 2004. (Donna Kenski, 

2005). This type of analysis looks at the meteorological conditions, such as temperature, 

pressure, wind speed, wind direction, relative humidity and dew point temperatures at the 

surface, as well as morning and evening mixing heights in the upper atmosphere which were 

present when higher concentrations of fine particles were monitored. Results of this CART 

analysis indicated factors that played a larger role in higher fine particle concentrations in 

Indiana were warm-weather conditions with high dew points, southwest winds and high evening 

mixing heights. Previous day’s concentrations of fine particles play a key role in higher impacts 

as well. 

Fine particles are made up of several constituents, including direct PM2.5, sulfates, nitrates, 

ammonium, organic carbon and elemental carbon. Depending on the time of the year, 

concentrations of particulate constituents vary, with nitrates being more prevalent in the winter 

and sulfates more prevalent in the summer. Sulfate and nitrate emission reductions have the 

biggest impact on lower future year fine particle concentrations. 

An analysis was conducted to review the daily fine particle concentrations over a year to 

determine the Air Quality Index (AQI) trends. Chart 7.4 below shows by year (2001 through 

2009), the percentage number of days during which fine particle concentrations reached the AQI 

ranges for “Good” (0 to 15.3 μg/m3), “Moderate” (15.4 μg/m3 to 40.4 μg/m3) and “Unhealthy for 

Sensitive Groups (USG)”(40.5 μg/m3

 to 65.4 μg/m3). There were no days during which fine 

particle levels reached the “Unhealthy” level of 65.5 μg/m3 to 150.4 μg/m3. 

Chart 7.4 

Distribution of PM2.5 Concentration Days on the AQI Levels of Health Concern 
45 

Table 7.4 shows how the years ranked for the three AQI ranges. The year 2009 had the most 

“Good” concentration days during the 9-year period analyzed (2001 through 2009). The year 

2005 had the most “Moderate” concentration days and the years 2002, 2005 and 2006 had the 

most “Unhealthy for Sensitive Group (USG)” concentration days with no USG days recorded in 

2004, 2007, 2008 and 2009. 

Table 7.4 

Ranking of Highest Number of Days at AQI Levels of Health Concern 

Ranking Good Moderate Unhealthy for 

Sensitive Group 

1st 2009 – 76% 2005 – 44% 2002 – 2%

2nd 2008 – 70% 2001 – 43% 2005 – 2%

3rd 2004 – 67% 2007 – 37% 2006 – 1%

4th 2006 – 65% 2003 – 36% 2001 – 1%

5th 2003 – 63% 2002 – 35% 2003 – 1%

6th 2007 – 63% 2006 – 34%

7th 2002 – 63% 2004 – 33%

8th 2001 – 56% 2008 – 30%

9th 2005 – 54% 2009 – 24%

7.9 Summary of Meteorological Analysis for Southwestern Indiana

Annual fine particle concentrations in the Southwestern Indiana Area are driven by higher fine 

particle concentration days that can occur during any time of the year. Conditions that are most 

prevalent during higher fine particle concentration days are lighter winds, higher relative 

humidity and above average temperatures in the summer and near normal temperatures in the 

fall, winter or spring. Approximately 70% of the days when PM2.5 concentrations were in the 

USG range occurred in the summer months with maximum high temperatures of 80o

 F or above. 

Weather plays a large role in fine particle concentration development and transport as 2001, 

2002, 2005 and 2006 were warmer than normal summers which translated to more days of 

moderate and unhealthy for sensitive group levels of air quality. Upper air weather patterns 

generally include ridging over the area with stagnant conditions at the surface. Surface winds 

from any direction can transport pollutants from surrounding areas into the Southwestern Indiana 

Area. Nitrates are bigger contributors to fine particle concentrations in the winter and sulfates 

are bigger contributors to fine particle concentrations in the summer. 

8.0 CORRECTIVE ACTIONS 

8.1 Commitment to Revise Plan

As noted in Section 4.6, IDEM commits to review and revise, as appropriate, its Maintenance 

Plan eight years after redesignation, as required by Section 175A of the CAA. 
46 

8.2 Commitment for Contingency Measures

IDEM will monitor fine particle concentrations to determine whether trends indicate higher 

values or whether emissions appear to be increasing. If it is determined that fine particle levels 

and emissions are increasing and action is necessary to reverse that trend, IDEM will take action 

to reverse the noted trend, prior to a violation of the standard occurring. 

IDEM commits to adopt and expeditiously implement necessary corrective action in the 

following circumstance: 

Action Level Response

An Action Level Response shall be prompted whenever a violation of the standard (three year 

average annual arithmetic mean value of 15.1 μg/m3

 or greater) occurs. In the event that the 

Action Level is triggered and is not found to be due to an atypical unfavorable meteorological 

condition, exceptional event, malfunction or noncompliance with a permit condition or rule 

requirement, IDEM will determine additional control measures needed to assure future 

attainment of the annual NAAQS for fine particles. In this case, measures that can be 

implemented in a short time will be selected in order to be in place within eighteen months from 

the end of the year that prompted the Action Level. 

Control Measure Selection and Implementation

Adoption of any additional control measures is subject to the necessary administrative and legal 

processes. This process will include publication of notices, an opportunity for public hearing and 

other measures required by Indiana law for rulemaking by state environmental boards. 

If a new measure or control is already promulgated and scheduled to be implemented at the 

federal or state level, and that measure or control is determined to be sufficient to address the 

upward trend in air quality, additional local measures may be unnecessary. Furthermore, IDEM 

will submit to U.S. EPA an analysis to demonstrate the proposed measures are adequate to return 

the area to attainment. 

8.3 Contingency Measures

Contingency measures to be considered will be selected from a comprehensive list of measures 

deemed appropriate and effective at the time the selection is made. Listed in this section are 

example measures that may be considered. The selection of measures will be based upon costeffectiveness, emission reduction potential, economic and social considerations or other factors 

that IDEM deems appropriate. IDEM will solicit input from interested and affected persons in 

the maintenance area prior to selecting appropriate contingency measures. All of the listed 

contingency measures are potentially effective or proven methods of obtaining significant 

reductions of fine particle precursor emissions. Because it is not possible at this time to 

determine what control measure will be appropriate at an unspecified time in the future, the list 

of contingency measures is not comprehensive. IDEM anticipates that if contingency measures 
47 

should ever be necessary, it is unlikely that a significant number (i.e., all those listed below) will 

be required. 

1) Alternative fuel and diesel retrofit programs for fleet vehicle operations. 

2) Require NOx or SO2 emission offsets for new and modified major sources. 

3) Require NOx or SO2 emission offsets for new and modified minor sources. 

4) Increase the ratio of emission offsets required for new sources. 

5) Require NOx or SO2 controls on new minor sources (less than 100 tons). 

6) Wood stove change-out program. 

7) Require increased recovery efficiency at sulfur recovery plants. 

8) Various emissions reduction measures or dust suppressant for unpaved roads and/or parking 

lots. 

9) Idling Restrictions. 

10) Broader geographic applicability of existing measures. 

11) One or more transportation control measures sufficient to achieve at least a half a percent 

(0.5%) reduction in actual area-wide precursor emissions. Transportation measures will be 

selected from the following, based upon the factors listed above, after consultation with 

affected local governments: 

a) Trip reduction programs, including, but not limited to, employer-based transportation 

management plans, area wide rideshare programs, work schedule changes and 

telecommuting. 

b) Transit improvements. 

c) Traffic flow improvements. 

d) Other new or innovative transportation measures not yet in widespread use that affect 

state and local governments, as deemed appropriate. 

No contingency measure shall be implemented without providing the opportunity for full public 

participation during which the relative costs and benefits of individual measures, at the time they 

are under consideration, can be fully evaluated. 

9.0 PUBLIC PARTICIPATION

This section will be finalized upon completion of the public hearing and public comment period. 

10.0 CONCLUSIONS 

The Southwestern Indiana Area has attained the annual NAAQS for fine particles. This petition 

demonstrates that the Southwestern Indiana Area has complied with the applicable provisions of 

the CAA regarding redesignation of nonattainment areas for fine particles. IDEM has prepared a 

State Implementation and Maintenance Plan that meets the requirement of Section 110(a)(1) of 

the CAA. 

Indiana has performed an analysis that shows the air quality improvements are due to permanent 

and enforceable measures and that additional significant regional NOx and SO2 reductions 
48 

following implementation of the Phase II NOx SIP Call and CAIR and/or its replacement rule or 

program will ensure continued compliance (maintenance) with the standard. Furthermore, 

emission projections indicate that NOx and SO2 emissions will continue to decline, thus ensuring 

that the area continues to maintain compliance with the standard and provide for an increasing 

margin of safety. Based on this presentation, the Southwestern Indiana nonattainment area for 

fine particles meets the requirements for redesignation under the CAA (Section 107(d)(3)) and 

U.S. EPA guidance for fine particles. 

Consistent with the authority granted to the U.S. EPA, the State of Indiana requests that the 

Southwestern Indiana nonattainment area for fine particles be redesignated to attainment for the 

annual fine particles standard simultaneously with U.S. EPA approval of this Indiana State 

Implementation and Maintenance Plan and the provisions contained herein.