IDEM 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.lN.gov

October 20, 2009

Mr. Bharat Mathur

Acting RegiOlial Administrator

U.S. Environmental Protection Agency

Region 5

77 West Jackson Boulevard

Chicago, IL 60604-3950

Re: Request for Redesignation Petition and

Maintenance Plan for Fine Particle

Attainment in the Central Indiana

Nonattainment Area

Dear Mr. Mathur:

The Indiana Department bfEnviro'nrnental Management (IDEM) submits a Redesignation

Petition and Maintenance Plan for the Central Indiana Area, consisting ofHamilton, Hendricks,

Johnson, Marion, and Morgan counties, which were designated as nonattainment ofthe annual

standard for fine particles on April 5, 2005. IDEM conducted a public hearing concerning the"

Redesignation Petition and Maintenance Plan on September 14, 2009 and the public comment

period concluded on September 18,2009.

This submittal documents the public review process, including a detailed summary of and

response to substantive comments.

The attached document consists ofthe following:

Redesignation Petition and Maintenance Plan

• A formal request that the Central Indiana Area be rede~ignated to attainment and

reclassified as maintenance. It contains and meets the requirements set forth in Section

107 ofthe Clean Air Act and in U.S. EPA Redesignation Guidance.

• A maintenance year of2020 is established and 2015 is analyzed as an interim year.

• The appendices ofthe document contain historic air quality trend data, projected emission

inventory data and thorough documentation ofthe mobile emissions analysis.

• A summary of, and response to, substantive written comments.

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Motor Vehicle Emissions Budgets

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

2010 and 2020. The Indianapolis Area Metropolitan Planning Organization's travel

demand model and MOBILE6 were used to determine emissions for the annual fine

particle nonattainrnent area.

• A conservative margin ofsafety was applied to the 2010 and 2020 projected emissions.

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

• Vehicle registration data gathered from the Indiana Bureau ofMotor Vehicles were used to

replace the MOBILE6 default vehicle age distribution.

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

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

Air Programs Branch, at (317) 233-5694.

DM/sad/skr

Attachments

Cc: John Sumrnerhays, U.S. EPA Region 5 (wi enclosures)

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

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

Sarah Raymond, IDEM (wi enclosures)

Phillip Roth, Indianapolis MPO (no enclosures)

Jerrold Bridges,MCCOG (no enclosures)
REQUEST FOR REDESIGNATION AND 

MAINTENANCE PLAN 

UNDER THE ANNUAL NATIONAL 

AMBIENT AIR QUALITY 

STANDARD FOR FINE PARTICLES 

Central Indiana Area

Prepared By: 

The Indiana Department of Environmental Management 

 October 2009
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 Particles Monitoring ..........................................................................................................3 

2.3 Emission Inventory ....................................................................................................................3 

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

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

2.6 Corrective Actions for Potential Future Violations of the Fine Particles Standard ...................4 

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

3.1 Fine Particles Monitoring Network ...........................................................................................5 

3.2 Ambient Fine Particles Monitoring Data ...................................................................................7

3.3 Quality Assurance ......................................................................................................................9 

3.4 Continued Monitoring ................................................................................................................9 

4.0 EMISSION INVENTORY ......................................................................................................9 

4.1 Emission Trends.......................................................................................................................10 

4.2 Base Year Inventory ................................................................................................................18 

4.3 Emission Projections ................................................................................................................18 

4.4 Demonstration of Maintenance ................................................................................................22 

4.5 Permanent and Enforceable Emission Reductions ..................................................................22 

4.6 Provisions for Future Updates .................................................................................................23 

5.0 TRANSPORTATION CONFORMITY BUDGETS...........................................................23 

5.1 On-Road Emission Estimates ..................................................................................................23 

5.2 Overview ..................................................................................................................................25 

5.3 Analysis Years .........................................................................................................................25 

5.4 Emission Estimates ..................................................................................................................25 

5.5 Motor Vehicle Emission Budget ..............................................................................................26 

6.0 CONTROL MEASURES AND REGULATIONS ..............................................................26 

6.1 Reasonably Available Control Technology (RACT) ...............................................................26 

6.2 Implementation of Past SIP Revisions .....................................................................................27 

6.3 Nitrogen Oxides (NOx) Rule ....................................................................................................27 

6.4 Measures Beyond Clean Air Act SIP Requirements ...............................................................28 

6.5 Controls to Remain in Effect ...................................................................................................30 

6.6 New Source Review Provisions ...............................................................................................31 

iii

7.0 MODELING AND METEOROLOGY ................................................................................31 
7.1 Summary of Modeling Results to Support Rulemakings ........................................................31 

7.2 LADCO’s Round 5 Speciated Modeled Attainment Test Results ...........................................34 

7.3 LADCO’s Round 5 Particulate Source Apportionment Results ..............................................35 

7.4 Summary of Existing Modeling Results ..................................................................................39 

7.5 Meteorological Analysis for Central Indiana...........................................................................39 

7.6 Surface Air Conditions Present During High Fine Particles Concentration Days ..................39 

7.7 Upper Air Conditions Present During High Fine Particles Concentration Days .....................40 

7.8 Analysis of Atmospheric Conditions During High Fine Particles Concentration Days ..........40 

7.9 Summary of Air Quality Index Days in Central Indiana .........................................................40 

7.10 Summary of Meteorological Analysis for Central Indiana ....................................................42 

8.0 CORRECTIVE ACTIONS ...................................................................................................42 

8.1 Commitment to Revise Plan ....................................................................................................42 

8.2 Commitment for Contingency Measures .................................................................................42 

8.3 Contingency Measures .............................................................................................................43 

9.0 PUBLIC PARTICIPATION ................................................................................................44 

10.0 CONCLUSIONS ..................................................................................................................44 

FIGURES

Figure 3.1 Central Indiana Nonattainment Area ..............................................................................6 

Figure 5.1 Central Indiana MPO Jurisdictions ..............................................................................24 

CHARTS

Chart 7.1 Regional/Emission Sector PSAT Results at E. Michigan Street PM2.5 Monitor ...........36 

Chart 7.2 Regional/Pollutant PSAT Results at E. Michigan Street PM2.5 Monitor .......................36 

Chart 7.3 Pie Charts-Species Modeled Contributions to W. 18th Street PM2.5 Monitor ...............37 

Chart 7.4 Pie Charts-Species Modeled Contributions to Washington Park PM2.5 Monitor .........37 

Chart 7.5 Pie Charts-Species Modeled Contributions to E. 75th Street PM2.5 Monitor ................38 

Chart 7.6 Pie Charts-Species Modeled Contributions to Mann Road PM2.5 Monitor ..................38 

Chart 7.7 Pie Charts-Species Modeled Contributions to E. Michigan Street PM2.5 Monitor .......38 

Chart 7.8 Distribution of PM2.5 Concentration Days on the AQI Levels of Health Concern ........41 

iv 

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

Table 3.1 Monitoring Data for the Central Indiana Area (Annual Average and 2006-2008 

Design Values) .................................................................................................................................7 

Table 4.1 Comparison of 2006 Estimated and 2020 Projected Emission Estimates Central 

Indiana Area (Annual-Tons) ..........................................................................................................21 

Table 5.1 Emissions Estimates for On-Road Mobile Sources .......................................................25 

Table 5.2 Motor Vehicle Emission Budgets in Tons Per Year ......................................................26 

Table 6.1 Trends in EGU NOx Emissions Statewide in Indiana ...................................................28 

Table 7.1 Modeling Results from U.S. EPA for the Clean Air Interstate Rule .............................32 

Table 7.2 LADCO’s Round 5 Modeling Results for the Clean Air Interstate Rule ......................34 

Table 7.3 LADCO’s Round 5 SMAT Modeling Results for Central Indiana (Percent 

Decrease from Observed to Modeled Concentrations) ..................................................................35 

Table 7.4 Ranking of Highest Number of Days at AQI Levels of Health Concern ......................41 

GRAPHS

Graph 3.1 Design Values for the Central Indiana Area for Fine Particles, 2004 

through 2008 ....................................................................................................................................8 

Graph 3.2 Central Indiana Annual Fine Particles Trends, 2004 through 2008 ...............................8 

Graph 4.1 Central Indiana Area NOx Point Source Emission Trends, 2002, 2005 

and 2006 .........................................................................................................................................11 

Graph 4.2 Central Indiana Area SO2 Point Source Emission Trends, 2002, 2005 

and 2006 .........................................................................................................................................11 

Graph 4.3 Central Indiana Area Direct PM2.5 Point Source Emission Trends, 2002, 

2005 and 2006 ................................................................................................................................12 

Graph 4.4 NOx Emission Trends, All Sources in the Central Indiana Area, 2002, 

2005 and 2006 ................................................................................................................................13 

Graph 4.5 SO2 Emission Trends, All Sources in the Central Indiana Area, 2002, 

2005 and 2006 ................................................................................................................................13 

Graph 4.6 Direct PM2.5 Emission Trends, All Sources in the Central Indiana Area, 

2002, 2005 and 2006 ......................................................................................................................14 

Graph 4.7 NOx Emissions from Electric Generating Units, Central Indiana Area, 

1999 to 2008 ..................................................................................................................................15 

Graph 4.8 SO2 Emissions from Electric Generating Units, Central Indiana Area, 

1999 to 2008 ..................................................................................................................................16 

Graph 4.9 Indiana Statewide NOx Emissions from Electric Generating Units, 1999 

to 2008 ...........................................................................................................................................17 

Graph 4.10 Indiana Statewide SO2 Emissions from Electric Generating Units, 1999 

to 2008 ...........................................................................................................................................17 

v 
Graph 4.11 Comparison of 2005 and 2006 Estimated and 2015 and 2020 Projected NOx 

Emissions for the Central Indiana Area .........................................................................................19 

Graph 4.12 Comparison of 2005 and 2006 Estimated and 2015 and 2020 Projected SO2 

Emissions for the Central Indiana Area .........................................................................................20 

Graph 4.13 Comparison of 2005 and 2006 Estimated and 2015 and 2020 Projected Direct 

PM2.5 Emissions for the Central Indiana Area ...............................................................................20 

Graph 4.14 Comparison of 2005 and 2006 Estimated and 2015 and 2020 Projected SO2, 

NOx, and Direct PM2.5 Emissions Trends for the Central Indiana Area .......................................21 

Graph 7.1 Modeling Results from U.S. EPA for the Clean Air Interstate Rule ............................33 

Graph 7.2 Modeling Results for Marion County PM2.5 Monitors for 2009, 2012, 

and 2018 .........................................................................................................................................34 

APPENDICES

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

(IDEM) Monitor Data Values for Central Indiana Area (2006-2008) 

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

Point Source Emissions (2002, 2005/2006) for Central Indiana Area 

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

Emission Trends, All Sources (2002, 2005/2006) for Central Indiana Area. 

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

Central Indiana Area 

E 2005, 2006 Base Year Emissions Inventory and 2015 and 2020 Projected Emissions 

Inventory Nitrogen Oxides (NOx), Sulfur Dioxide (SO2) and Direct Fine Particulate 

Matter (PM2.5), Central Indiana Area 

F Mobile Source Input/Output Calculation Files 

G Indiana Department of Environmental Management (IDEM) Area Source Inventory – 

Standard Operating Procedure 

H Lake Michigan Air Directors Consortium Emission Estimates Technical Support 

Document 

I Lake Michigan Air Directors Consortium Round 5 Modeling Technical Support 

Document 

J Public Participation Process Documents 

vi 
REQUEST FOR REDESIGNATION AND MAINTENANCE PLAN 

UNDER THE ANNUAL NATIONAL AMBIENT AIR 

QUALITY STANDARD FOR FINE PARTICLES 

CENTRAL INDIANA AREA 

1.0 INTRODUCTION

 

This document supports Indiana’s request that Hamilton, Hendricks, Johnson, Marion, and 

Morgan counties (Central Indiana Area), be redesignated from nonattainment to attainment of 

the 1997 annual standard for fine particles. The Central Indiana Area has recorded three years of 

quality assured ambient air quality monitoring data for the years 2006 through 2008, 

demonstrating attainment with the annual standard for fine particles, and is 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, then 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 standards were legally challenged and 

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

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

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

effective date of April 5, 2005. 

1
Table 1.1 

National Ambient Air Quality Standards for Fine Particles 

Annual 24-Hour 

1997 Fine Particles 

Standards (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 

Standards (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 Central 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 April 5, 2005, based on 2001 through 2003 monitoring data, U.S. EPA designated the Central 

Indiana Area as nonattainment of the annual standard for fine particles. The nonattainment areas 

are subject to CAA Part D, Title 1, Section 172 Subpart 1 requirements, including the 

development of a plan to reduce nitrogen oxides (NOx), sulfur dioxide (SO2) and direct PM2.5

emissions, and demonstrate that the area will meet the annual standard for fine particles by April 

5, 2010. There were no monitors in Indiana that violated the 1997 24-hour standard for fine 

particles and no monitors in Indiana currently violate the 2006 24-hour standard for fine 

particles. As a result, the Central Indiana Area was designated nonattainment solely under the 

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

fine particles. 

The Central Indiana Area, as defined in Section 1.2, has not previously been subject to 

nonattainment area rulemakings for fine particles. However, Marion County was subject to 

nonattainment area rulemakings under the 1-hour ozone standard. The 1-hour ozone standard 

was revoked on June 15, 2005. Boone, Hamilton, Hancock, Hendricks, Johnson, Madison, 

Marion, Morgan, and Shelby counties in Central Indiana had also been subject to nonattainment 

area rulemakings under the 8-hour ozone standard and all counties in Central Indiana were 

redesignated to attainment and classified as maintenance under the 8-hour ozone standard on 

October 19, 2007. 

 

 1.2 Geographical Description

The Central Indiana Area nonattainment area for annual fine particles includes Hamilton, 

Hendricks, Johnson, Marion and Morgan counties and contains such cities as Beech Grove, 

Carmel, Franklin, Greenwood, Indianapolis, Lawrence, Martinsville and Noblesville and such 

towns as Avon, Brownsburg, Fishers, Mooresville, Plainfield and Speedway. This area is 

depicted in Figure 3.1. 

 1.3 Status of Air Quality

2
Monitoring data for fine particles for the three years, 2006 through 2008, demonstrates that air 

quality has met the annual NAAQS for fine particles in the Central Indiana Area. 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 Criteria Pollutant Section of U.S. EPA Region V. The 

specific requirements for redesignation are listed below. 

2.2 Fine Particles Monitoring 

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

CFR 50.13, has been attained. Fine particles 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) A commitment that, once redesignated, the State will continue to operate an 

appropriate monitoring network to verify the maintenance of the attainment 

status. 

2.3 Emission Inventory 

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

particles completed for the base year (2006 in this case). 

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

redesignation. 

3
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, the Indiana Department of 

Environmental Management (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) 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. 

4
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 Particles Monitoring Network

There are currently four Federal Reference Method monitors measuring fine particles 

concentrations for the Central Indiana Area. Three of the monitors are located in Marion County 

at Washington Park, W. 18th Street and E. Michigan Street. The fourth monitor is located in 

Anderson in Madison County. The four monitors are operated by IDEM’s Office of Air Quality 

(OAQ). A listing of the monitor readings from 2006 through 2008, are shown in Table 3.1 and 

Appendix A and were retrieved from U.S. EPA’s Air Quality System (AQS) database. The 

locations of the monitoring sites for the Central Indiana Area are shown in Figure 3.1. 

IDEM’s OAQ also operates two monitors in the Central Indiana Area (West Street and English 

Avenue in Marion County) that are considered source oriented monitors. While these monitors 

are not used to determine attainment with the annual standard for fine particles, the monitoring 

locations are included as supporting material. Two monitors (Mann Road and E. 75th Street in 

Marion County) in the Central Indiana Area were discontinued at the end of 2007. 

5
Figure 3.1 

Central Indiana Nonattainment Area 

Washington Park

Michigan Street

W. 18th Street

English Ave

West Street

Anderson

Mann Road

E. 75th Street

Boone

Shelby

Marion

Clinton

Morgan

Madison

Hamilton

Tipton

Hendricks

Johnson

Hancock

I465 I465 N

U3

U31

I74

I70

I65

I69

I70

U36

U40

U136

U421

U31

U52

Legend

PM 2.5 Monitor

PM 2.5 Source Oriented Monitor

PM 2.5 Monitor Discontinued

Interstate Highway

US Highway

PM 2.5 Annual Standard Central Indiana Nonattainment Area

Attainment

Nonattainment

10/15/09

0 1 5 M 0 20 i

0 10 20 5 Km

6
3.2 Ambient Fine Particles Monitoring Data

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

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

fine particles 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 particles concentrations (or the 

design value) 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/m3meet the 

standard. Values equal to or greater than 15.1 μg/m3 exceed the standard. 

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 particles 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 

particles values by site and the 2006 through 2008 design values for the four active fine particles 

monitoring sites in the Central Indiana Area. Refer to Appendix A for the complete monitoring 

data summary from 2000 to 2008 for all of the Central Indiana monitors which includes the four 

active fine particles monitoring sites, the two source oriented monitoring sites and two 

discontinued monitoring sites in the Central Indiana Area. 

Table 3.1 

Monitoring Data for the Central Indiana Area 

(Annual Average and 2006-2008 Design Values) 

SITE ID COUNTY SITE NAME YEAR Annual Average 

μg/m3

2006-2008 

Average μg/m3

18-095-0009 Madison Anderson 2006 12.06 

18-095-0009 Madison Anderson 2007 13.57 

18-095-0009 Madison Anderson 2008 12.13 12.6 

18-097-0078 Marion Washington Park 2006 14.14 

18-097-0078 Marion Washington Park 2007 15.66 

18-097-0078 Marion Washington Park 2008 13.02 14.3 

18-097-0081 Marion W 18th Street 2006 14.12 

18-097-0081 Marion W 18th Street 2007 16.07 

18-097-0081 Marion W 18th Street 2008 13.75 14.6 

18-097-0083 Marion E. Michigan Street 2006 14.15 

18-097-0083 Marion E. Michigan Street 2007 15.93 

18-097-0083 Marion E. Michigan Street 2008 13.17 14.4 

7
Graph 3.1 visually demonstrates the 2004 through 2008 design values for the Central Indiana 

nonattainment area.

Graph 3.1

Design Values for the Central Indiana Area for Fine Particles, 2004 through 2008 

10.5

11.5

12.5

13.5

14.5

15.5

16.5

Anderson

Mann Road

Washington

Park

E. 75th

Street

W. 18th

Street

E. Michigan

Street

ug/m3

2004-2006 2005-2007 2006-2008 Annual PM 2.5 Standard

Note: The Mann Road and E. 75th Street monitors were discontinued December 31, 2007

Graph 3.2 

Central Indiana Annual Fine Particles Trends, 2004 through 2008 

11.00

12.00

13.00

14.00

15.00

16.00

17.00

18.00

19.00

20042005200620072008

Year

ug/m3

Anderson Mann Road Washington Park

E. 75th Street W. 18th Street E. Michigan Street

Annual PM 2.5 Standard

Note: The Mann Road and E. 75th Street monitors were discontinued December 31, 2007 

8
The design values for the Central Indiana Area demonstrate that the annual NAAQS for fine 

particles has been attained. 

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 four fine particles 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 particulate matter 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 2008 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 Clean Air Interstate Rule and/or 

Replacement Rule is implemented. 

3.3 Quality Assurance

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

the Indiana Quality Assurance Manual. IDEM has 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 concentrations of fine particles at the 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 monitoring network through the annual network review should changes 

become necessary in the future. IDEM will continue to quality assure the 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 Rule requires the submittal of a 

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

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

particles (base year). Indiana is using 2006 as the base year. The 2006 data was grown from the 

2005 emissions inventory which represents the most complete inventory available at this time. 

Indiana 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: 

9
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 federal 

implementation rule for fine particles, Indiana does not consider volatile organic compounds 

(VOCs) or ammonia 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 the trend in point source emissions of NOx, SO2 and direct PM2.5, 

respectively, that generally correspond to the years of monitored values used in this report. The 

point source data are taken from Indiana's annual emissions reporting program. The Central 

Indiana Area had a 29.84% reduction in NOx point source emissions, and a 10.73% reduction in 

SO2 point source emissions. The large decrease in SO2 point source emissions from 2005 to 

2006 is due to the shut down of the Citizens Gas and Coke plant in Indianapolis. An increase in 

direct PM2.5 point source emissions is noted, but this increase in direct PM2.5 emissions from 

2002 to 2006 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 2006 data is grown. Though a large increase in direct PM2.5 point 

source emissions is depicted, the total anthropogenic direct PM2.5 emissions have decreased by 

44.34% within this period. See Graph 4.6 depicting the trend of PM2.5 emissions from all 

anthropogenic sources. Regional NOx emission reductions affect fine particles levels in the 

Central Indiana Area far more than NOx emission reductions within the area itself. As Graph 4.7 

illustrates, Central Indiana NOx emissions from EGUs have decreased substantially during this 

time period as well. Graphs and data tables of emissions from each source category are available 

in Appendix C. 

10
Graph 4.1 

Central Indiana Area NOx Point Source Emission Trends, 2002, 2005 and 2006 

-

5,000

10,000

15,000

20,000

25,000

2002 2005 2006

Year

Tons per Year

NOX

Graph 4.2 

Central Indiana Area SO2 Point Source Emission Trends, 2002, 2005 and 2006 

50,000

52,500

55,000

57,500

60,000

62,500

65,000

67,500

70,000

72,500

75,000

2002 2005 2006 Year

Tons per Year

SO2 

11
Graph 4.3 

Central Indiana Area Direct PM2.5 Point Source Emission Trends, 2002, 2005 and 2006 

-

200

400

600

800

1,000

1,200

2002 2005 2006

Year

Tons per Year

PM 2.5

All Anthropogenic Sources

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

source), were prepared for 2002 and 2005. The 2006 data was grown from the 2005 emission 

inventory. Graphs 4.4, 4.5 and 4.6 show the trends for the total emissions for all anthropogenic 

source categories in these years, for NOx, SO2 and direct PM2.5, which also roughly follow the 

years of monitored trends discussed in Section 3.0. There is a downward trend in NOx, SO2 and 

direct PM2.5 emissions from 2002 to 2005 and 2006. The decrease in NOx can be largely 

attributed to those EGUs located within and surrounding the Central Indiana Area that have 

reduced their NOx emissions as a result of the NOx SIP Call. Graphs and data tables of 

emissions from each source category are available in Appendix C. 

12
Graph 4.4 

NOx Emission Trends, All Sources in the Central Indiana Area, 2002, 2005 and 2006 

60,000

62,000

64,000

66,000

68,000

70,000

72,000

74,000

76,000

78,000

2002 2005 2006

Year

Tons per Year

NOX

Graph 4.5 

SO2 Emission Trends, All Sources in the Central Indiana Area, 2002, 2005 and 2006

-

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

2002 2005 2006 Year

Tons per Year

SO2 

13
Graph 4.6 

Direct PM2.5 Emission Trends, All Sources in Central Indiana Area, 2002,2005 and 2006 

-

1,000

2,000

3,000

4,000

5,000

6,000

2002 2005 2006 Year

Tons per Year

PM 2.5 

EGU Sources

Graphs 4.7 and 4.8 depict the trends in NOx and SO2 emissions from Central Indiana EGUs for 

the years 1999 to 2008. There are four EGUs located in Central Indiana: Indiana Municipal 

Power Plant-Anderson (Madison County), Cinergy-Noblesville (Hamilton County), Indianapolis 

Power and Light-Harding Street (Marion County) and Indianapolis Power and Light-Eagle 

Valley (Morgan County). 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. 

These data were taken from U.S. EPA's Clean Air Markets database1

. 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 

 

1

 http://www.epa.gov/airmarkets 

14
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 

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

place through 2008, at which time the Clean Air Interstate Rule (CAIR) program superseded it. 

CAIR, issued in March 2005, adopted by the Indiana Air Pollution Control Board on November 

1, 2006 and to be implemented by 2010, will reduce regional EGU NOx emissions statewide by 

approximately another 17% by 2015. The D.C. Circuit court’s vacatur of CAIR in July of 2008 

and subsequent remand without vacatur of CAIR in December of 2008 directs U.S. EPA to 

revise the CAIR rule in the future. The future version of CAIR (Replacement Rule) will result in 

similar or greater emission reductions than assumed within the emission inventories and 

modeling (based on what the rule would address in response to the court’s opinion). 

Graph 4.7

NOx Emissions from Electric Generating Units, Central Indiana Area, 1999 to 2008 

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

1999200020012002200320042005200620072008

Year

Tons per Year

NOx

15
Graph 4.8

SO2 Emissions from Electric Generating Units, Central Indiana Area, 1999 to 2008 

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

1999200020012002200320042005200620072008

Year

Tons per Year

SO2

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

4.10, there are moderate reductions to date. Indiana does expect to see significant reductions in 

SO2 emissions from CAIR and BART (Best Available Retrofit Technology), once implemented. 

 Additional NOx control technologies have been installed on various emission units at the 

Indianapolis Power & Light Company (IPL)-Harding Street Generating Station located in 

Marion County and the IPL-Eagle Valley Generating Station, located in Morgan County, since 

the 2001-2003 monitoring period. These control technologies include Selective Non-Catalytic 

Reduction, Selective Catalytic Reduction, Neural Net Controls, Low NOx Burners, and 

Separated Overfire Air. The SO2 data from 2008 reflects the installation of a flue gas 

desulphurization system at the IPL-Harding Street Generating Station that became operational in 

2007. As IPL indicates, many control technologies have been installed voluntarily and are not 

required to be operated. Most of the major sources within the area are subject to the NOx SIP 

Call, CAIR or RACT requirements. Appendix B shows detailed emissions for the point source 

emissions, and Appendix D shows detailed emissions for the EGUs. 

16
Graph 4.9 

Indiana Statewide NOx Emissions from Electric Generating Units, 1999 to 2008 

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

1999200020012002200320042005200620072008

Year

Tons per Year

NOx

Graph 4.10 

Indiana Statewide SO2 Emissions from Electric Generating Units, 1999 to 2008 

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

1999200020012002200320042005200620072008

Year

Tons per Year

SO2

17
4.2 Base Year Inventory

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

nonroad and point sources for direct PM2.5 and precursors of fine particles (NOx and SO2) for 

2005 (the year with the most complete emissions inventory available at this time). The 2006 

data was grown from the 2005 emission inventory to represent a base year for maintenance 

purposes. The 2007 implementation rule for the annual fine particles standard states that NOx, 

SO2 and direct PM2.5 are the regulated precursors of fine particles. VOCs are not required to be 

addressed unless the State or EPA makes a technical demonstration that emissions of VOCs from 

sources in the State significantly contribute to PM2.5 concentrations in a given nonattainment 

area. U.S. EPA and Indiana do not recognize VOCs as a significant contributor to fine particles 

formation in the State of Indiana. Indiana’s 2006 base year inventory was determined by the 

following: 

• Area sources were grown from the Indiana 2002 periodic inventory submitted to U.S. 

EPA. 

• Mobile source emissions were calculated from MOBILE6 produced emission factors and 

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

interpolated as needed to determine 2006 base year values. 

• Point source information was compiled from IDEM’s annual emissions statement 

database. 

• Biogenic emissions are not included in these summaries. 

• Nonroad emissions were grown 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, the Lake Michigan Air Directors’ Consortium (LADCO) (Midwest 

Regional Planning Organization), 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. 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 the U.S. EPA and other stakeholders, IDEM selected the year 2020 as the 

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

inventories for 2015 and 20202 for the Central Indiana Area. These emission projections were 

prepared by IDEM, with assistance from LADCO and the Indianapolis Metropolitan Planning 

Organization. The detailed inventory information for the Central Indiana Area for 2015 and 

 

2

 EGU emission projections for the year 2020 are based on 2018 emission estimates. 

18
2020 is 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 (2006-grown from the 2005 emission inventory), interim year 

(2015), and maintenance year (2020) inventories for the Central Indiana Area, which are 

summarized below. 

Graphs 4.11, 4.12 and 4.13 visually compare 2006 (base year-grown from the 2005 emission 

inventory) NOx, SO2 and direct PM2.5 estimated emissions with the 2015 and 20203

 projected 

emissions for the Central 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 and 2020 (i.e. 2018) were projected utilizing the 

Department of Energy Information’s Annual Energy Outlook Supplemental tables. These tables 

were generated for the reference case of the Annual Energy Outlook 2007 (AEO 2007) using the 

National Energy Modeling System. 

Graph 4.11 

Comparison of 2005 and 2006 Estimated and 2015 and 20203

 Projected NOx Emissions for 

the Central Indiana Area 

-

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

2005 2006 2015 2020 Year

Tons per Year

NOX

 

3

 EGU emission projections for the year 2020 are based on 2018 emission estimates. 

19
Graph 4.12 

 Comparison of 2005 and 2006 Estimated and 2015 and 20204 Projected SO2 Emissions for 

the Central Indiana Area 

-

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

2005 2006 2015 2020

Year

Tons per Year

SO2

Graph 4.13 

Comparison of 2005 and 2006 Estimated and 2015 and 20204

 Projected Direct PM2.5

Emissions for the Central Indiana Area 

-

500

1,000

1,500

2,000

2,500

3,000

3,500

2005 2006 2015 2020

Year

Tons per Year

PM 2.5

 

4

 EGU emission projections for the year 2020 are based on 2018 emission estimates. 

20
Graph 4.14 

Comparison of 2005 Estimated and 2015 and 20205 Projected SO2, NOx and Direct PM2.5

Emission Trends for the Central Indiana Area 

-

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

2005 2006 2015 2020

Year

Tons per Year

NOX SO2 PM 2.5

Table 4.1 

Comparison of 2006 Estimated and 20205 Projected Emission Estimates Central Indiana 

Area (Annual-Tons) 

2006 2020 Change % Change 

NOx 66,032.06 32,340.01 -33,692.05 51.02% decrease 

SO2 68,690.10 31,962.83 -36,727.27 53.46% decrease 

Direct PM2.5 2,903.64 1,736.16 -1,167.48 40.20% decrease 

NOx emissions within the Central Indiana Area are projected to decline by 51.02% between 2006 

and 20205

. Emission reduction benefits from U.S. EPA rules covering the NOx SIP Call, Tier 2 

Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements, Heavy-Duty 

Highway Engine Rule, and Nonroad Diesel Engine Rule are factored into the changes. Further, 

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

particles levels entering Central Indiana Area will also be decreased. 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 Central Indiana Area or other upwind counties. Therefore, potential reductions are 

 

5

 EGU emission projections for the year 2020 are based on 2018 emission estimates. 

21
not included in Graph 4.14 or Table 4.1. SO2 emissions within the Central Indiana Area are 

projected to decline by 53.46% between 2006 and 20206. Direct PM2.5 emissions from 2006 to 

20206 are projected to decline by 40.20% within the Central Indiana Area, see Table 4.1. 

4.4 Demonstration of Maintenance

Ambient air quality data from all the monitoring sites indicate that air quality in the Central 

Indiana Area met the annual standard for fine particles for the three-year period ending in 2008. 

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.” Emissions 

projections outlined in Section 4.0 of this document clearly illustrate that regional NOx, SO2 and 

direct PM2.5 emissions will continue to decline leading to local reductions between 2006 (base 

year-grown from the 2005 emission inventory) and 20206 (maintenance plan horizon). Section 

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

support these conclusions. Therefore, air quality should meet the annual NAAQS for fine 

particles through the projected years of 2015 and 2020. 

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

once every three years, or annually, if the SO2 or NOx 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 2008, 2011, 2014 and 2017, as necessary, to comply with the 

inventory reporting requirements established in the CAA. Emissions information will be 

compared to the 2006 base year and the 20206 projected maintenance year inventories to assess 

emission trends, as necessary, to assure continued compliance with the annual standard for fine 

particles. 

4.5 Permanent and Enforceable Emission Reductions

Permanent and enforceable reductions of SO2, direct PM2.5 and NOx 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 Central Indiana Area, as well 

as the implementation status of each measure. 

4.6 Provisions for Future Updates 

 

6

 EGU emission projections for the year 2020 are based on 2018 emission estimates. 

22
 

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 TRANSPORTATION CONFORMITY BUDGETS 

5.1 On-Road Emissions Estimates

The Indianapolis Department of Metropolitan Development (DMD), the Madison County 

Council of Governments (MCCOG) and the Columbus Area Metropolitan Planning Organization 

are the Metropolitan Planning Organizations (MPOs), whose planning areas intersect the five 

county Central Indiana Area. In addition, significant portions of the nonattainment area are not 

under the jurisdiction of any MPO. These planning areas and the current PM2.5 nonattainment 

area are illustrated in Figure 5.1. 

An interagency consultation group consisting of representatives from the three MPOs, the 

Indiana Department of Transportation, IDEM, the Federal Highway Administration and local 

transit and environmental quality providers jointly determines regional significance. Primary 

responsibility for modeling emissions falls under the purview of DMD, which runs the 

MOBILE6 model to arrive at emission rates, and its regional travel model to develop estimates 

of vehicle miles traveled (VMT) for all areas, except for the MCCOG planning area, which 

administers its own travel model. DMD then compiles all results into a regional emissions 

analysis, which all MPOs then adopt following a public involvement period. 

23
Figure 5.1 

Central Indiana MPO Jurisdictions

These models simulate the traffic in the area and are used to predict what the traffic would be 

like in future years given growth expectations. The models are used mostly to identify where 

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

that need. They are also used to support the calculation of mobile source emissions. The travel 

demand forecast model is used to predict the total daily VMT and the U.S. EPA software 

program, MOBILE6, is used to calculate the emissions per mile. The product of these two 

outputs, once combined, is the estimated total amount of pollution emitted by the on-road 

vehicles for the area analyzed.

24
5.2 Overview 

Broadly described, MOBILE6 is used to determine “emission factors”, which are the average 

emissions per mile (grams/mile) for 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 effect on the emission factors. The facility-type on 

which the vehicles are traveling (MOBILE6 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. These data are estimated using the 

best available data to create emission factors for PM2.5 precursors including NOx and SO2. After 

emission factors are determined, they must be multiplied by the VMT to determine the quantity 

of vehicle-related emissions. This information derives from the travel demand model. 

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

and likely some additional modeling done. MOBILE6 input and output files can be found in 

Appendix F. 

5.3 Analysis Years

The travel demand model contains road networks that are time specific. The Central Indiana 

MPOs have modeled the years 2002, 2010 and 2020. Information, including emissions, has been 

interpolated from 2002 and 2010 for the year 2006. This Redesignation Petition provides 

emission inventory estimates for 2006, 2010, 2015 and 2020 to meet the requirements specified 

by the CAA and U.S. EPA. The emissions estimates outlined in Section 4.0 of this document 

reference the mobile source emissions data contained in Table 5.1. 

5.4 Emission Estimates 

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

2006, 2010 and 2020. 

Table 5.1 - Emission Estimates for On-Road Mobile Sources 

2006 2010 2020 

VMT (miles/day) 48,394,097.00 49,885,362.00 57,422,782.00 

PM2.5 (tons/year) 416.63 351.75 228.75 

NOx (tons/year) 22,734.38 18,767.25 8,118.00 

25
5.5 Motor Vehicle Emission Budget 

Table 5.2 contains the motor vehicle emissions budgets for the entire nonattainment area for the 

years 2010 and 2020. 

Table 5.2 – Motor Vehicle Emission Budgets in Tons Per Year 

Year 2010 2020 

PM2.5 369.34 251.63 

NOx 19,705.61 8,929.80

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

mobile source SO2 to be a significant contributor to fine particles for this nonattainment area, as 

mobile source SO2 constitutes less than 1.2 % of the area’s total anthropogenic emissions. 

These budgets include the emissions estimates calculated for 2010 and 2020. The emission 

estimates are derived from the MPO’s travel demand models and MOBILE6, as described above. 

Through the interagency consultation process, it was determined that an interim budget for the 

year 2010, in addition to the budget for the year 2020, would be appropriate. A reasonable 

margin of safety has been applied to the 2010 and 2020 budgets in the amount of 5% and 10% 

respectively. Margins of safety are used to accommodate the wide array of assumptions that are 

factored into the calculation process. Since assumptions change over time, it is necessary to 

have a margin of safety that will accommodate the impact of refined assumptions in the process. 

 The resulting 2010 and 2020 budgets for total PM2.5 and NOx emissions remain well below the 

2006 base year emissions referenced in Table 5.1. 

All methodologies, latest planning assumptions and margins of safety were determined to be 

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 Central 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, Indiana in the mid-1990s 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 

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 

26
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 Central Indiana Area attained the annual standard 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 Clean Air Act requirements already in the State Implementation 

Plan and provide secondary benefits for PM 2.5. 

6.2 Implementation of Past SIP Revisions

The area was only recently designated nonattainment for the annual standard for fine particles 

and the area has now 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 Central Indiana Area because of the number of affected 

units within the region. From Graphs 4.7 and 4.9, it can be seen that emissions covered by this 

program have been 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 will stay in place through 2008, at which time the caps in the CAIR 

program will supersede 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 Central Indiana 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. The Indiana Phase II NOx SIP Call Rule became effective February 26, 2006 and 

implementation began in 2007. 

Table 6.1 

27
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 

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 Standards7

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 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 Standards8

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

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

and testing procedures, that began in 2007, reduced particulate matter 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 particulate matter emissions and a 95% reduction in NOx

 

7 http://www.epa.gov/fedrgstr/EPA-AIR/2000/February/Day-10/a19a.htm 8 http://www.epa.gov/fedrgstr/EPA-AIR/1997/October/Day-21/a27494.htm

28
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 Standards9

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%. Nonroad diesel fuel currently averages approximately 3,400 

parts per million (ppm) sulfur. This rule limits nonroad diesel sulfur content to 500 ppm 

in 2006 and 15 ppm in 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 offhighway motorcycles and all-terrain vehicles, at least 50% of a manufacture’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. 

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 is to reduce interstate transport of precursors to fine particles and 

 

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

29
ozone. 

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

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

[megawatt electrical] 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 provides 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 is allowing 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 requires compliance effective January 1, 

2009. 

On March 10, 2005, the U.S. EPA finalized the Clean Air Interstate Rule (CAIR). 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 of 

2008 and subsequent remand without vacatur of CAIR in December of 2008 directs U.S. 

EPA to revise the CAIR rule in the future. The future version of CAIR (Replacement 

Rule) will result in similar or greater emission reductions than assumed within the 

emission inventories and modeling (based on what the rule would address in response to 

the court’s opinion). 

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

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

reductions in annual fine particles 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 SO2, NOx

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

the Central Indiana Area. 

30
Indiana, through IDEM’s Office of Air Quality 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 Central 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 fine particles 

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

Central Indiana region to determine the effect of emission control strategies on fine particles 

levels. Future year modeled annual fine particles concentrations are expected to be reduced by 

8% to 24% from baseline design values. 

7.1 Summary of Modeling Results to Support Rulemakings

U.S. EPA Modeling for Clean Air Interstate Rule (CAIR), 2005

Indiana will reduce SO2 emissions from the implementation of CAIR in 2009 by 222,000 tons 

from the 2009 emissions projections without CAIR, and by 2015, SO2 emissions will be reduced 

by an additional 178,000 tons from the 2015 emissions projections without CAIR. Indiana will 

reduce NOx emissions from the implementation of CAIR in 2009 by 113,000 tons from the 2009 

emissions projections without CAIR, and by 2015, NOx emissions will be reduced by 149,000 

tons from the 2015 emissions projections without CAIR. The D.C. Circuit court’s vacatur of 

CAIR in July of 2008 and subsequent remand without vacatur of CAIR in December of 2008 

directs U.S. EPA to revise the CAIR rule in the future. The future-year emission reduction 

projections listed above will change. The future version of CAIR (Replacement Rule) will result 

in similar or greater emission reductions than assumed within the emission inventories and 

modeling (based on what the rule would address in response to the court’s opinion). However, 

the large NOx and SO2 emission reductions demonstrate the photochemical model’s response to 

those reductions on modeled concentrations. 

31
U.S. EPA performed modeling to support the emission reductions associated with CAIR. U.S. 

EPA used the Community Multiscale Air Quality Model (CMAQ) applied to the 2001 

meteorology, as processed by the Mesoscale Model (MM5). Emissions input into CMAQ 

included SO2, NOx, VOC, ammonia and direct PM2.5 for 2001. The modeling was based on the 

annual fine particles design values calculated from 1999 through 2003. Future year modeling 

was conducted, which included Marion and Madison counties, and the future year design values 

for 2010 and 2015 were evaluated for attainment of the annual NAAQS for fine particles as 

shown in Table 7.1. Fine particles concentrations are accounted for by modeling both the base 

future year emissions and the emissions reductions associated with CAIR. U.S. EPA found 

model performance met suggested benchmark performance goals within the range or better than 

other comparable modeling applications. 

Table 7.1 

Modeling Results from U.S. EPA for the Clean Air Interstate Rule 

County MSA/CMSA 

Design Value 

 1999-2003 

Future Design 

Value 

2010 Base 

Future 

Design 

Value 2010 

with CAIR 

Future Design 

Value 2015 

without CAIR 

Future 

Design 

Value 2015 

with CAIR 

(μg/m3) (μg/m3) (μg/m3) (μg/m3) (μg/m3) 

Marion Co. Indianapolis, IN 16.9 16.8 15.5 16.8 15.4 

Madison Co. Indianapolis, IN 14.8 14.5 13.3 14.3 13.0 

Modeling results show that the base future year modeling without CAIR accounts for 

approximately 0.1 to 0.3 μg/m3

 decreases in concentrations for 2010 and approximately 0.1 to 

0.5 μg/m3 decreases in concentrations for 2015. The future year modeling showed that 

emissions reductions associated with CAIR would account for approximately 1.4 to 1.5 μg/m3

decreases in concentrations for 2010 and approximately 1.5 to 1.8 μg/m3

 decreases by 2015. 

Therefore, impacts from CAIR equate to modeled concentration decreases of 1.4 μg/m3 by 2010 

and 1.5 μg/m3

 by 2015 in Marion County. 

While results of U.S. EPA’s CAIR modeling show modeled concentrations above the standard, it 

should be noted that the base year design value used by U.S. EPA was taken from 1999-2003 

and is higher than current design values in the area. From Graph 7.1, the 1999-2003 design 

value can be compared to the maximum 2004-2008 design value within Marion County. The 

resulting decrease of the design value is 1.4 μg/m3. Therefore, U.S. EPA’s CAIR modeling, 

using current 2004-2008 design values, would show lower modeled concentrations below the 

annual fine particles standard of 15.0 μg/m3

 . 

Graph 7.1 

Modeling Results from U.S. EPA for the Clean Air Interstate Rule 

32
Central Indiana PM2.5 Design Values

1999 - 2008

15

15.5

16

16.5

17

1999-2003 2000-2004 2001-2005 2002-2006 2003-2007 2004-2008

Design Value Years

PM2.5 Concentrations (ug/m3)

Results of the U.S. EPA CAIR modeling show that Marion County will approach the annual fine 

particles NAAQS in 2010 with modeled impacts reduced by 8 % to 14%. With further 

reductions projected in CAIR for 2015, all design values decrease by 9% to 15% and attain the 

annual NAAQS for fine particles. If using current design values as a baseline, U.S. EPA’s CAIR 

modeling shows Marion County would attain the current annual fine particles standard. 

LADCO Modeling for Clean Air Interstate Rule 

LADCO conducted modeling to determine the impact of CAIR in the Midwest. LADCO’s 

modeling used the Comprehensive Air Quality Model with extensions (CAMx) applied to the 

year 2005 meteorology, as processed by the MM5. Emissions input into CAMx included SO2, 

NOx, VOC, ammonia and direct PM2.5 for 2005. The modeling was based on 2003 through 2007 

design values. Future year modeling for 2009, 2012, and 2018 was conducted and the future 

year design values were determined, as shown in Table 7.2. 

Table 7.2 

LADCO’s Round 5 Modeling Results for the Clean Air Interstate Rule 

Base-case Base-case Base-case 

33
Monitor ID 

Monitor 

Name County 

Design Value 

2003-2007 

with CAIR - 

2009 

with CAIR - 

2012 

with CAIR – 

2018 

(μg/m3) (μg/m3) (μg/m3) (μg/m3) 

18-097-0042 Mann Road Marion 14.2 11.9 11.7 11.2 

18-097-0078 Washington Park Marion 15.3 12.8 12.6 12.0 

18-097-0079 E. 75th St. Marion 14.7 12.4 12.2 11.6 

18-097-0081 W. 18th St. Marion 16.1 13.4 13.2 12.6 

18-097-0083 E. Michigan St. Marion 15.9 13.4 13.1 12.6 

Results of the LADCO CAIR modeling show that Marion County will attain the annual NAAQS 

for fine particles of 15 μg/m3

 by 2009. As shown in Table 7.2, future year modeled annual fine 

particles concentrations for 2009 will be 16% to 17% lower than baseline annual fine particles 

design values, 17% to 18% lower in 2012 and 21% to 22% lower in 2018 and will continue to 

decrease, thereafter. A graphical representation is shown in Graph 7.2. The Mann Road and E. 

75th Street monitors were closed at the end of 2007. However, at the time the modeling was 

conducted, the Mann Road and E. 75th Street monitors were still in operation. 

Graph 7.2 

Modeling Results for Marion County PM2.5 Monitors for 2009, 2012 and 2018 

Central Indiana Modeled PM2.5 Concentrations 

for 2009, 2012 and 2018

10

11

12

13

14

15

16

17

2005 2009 2012 2018

Modeled Year

PM2.5 Concentrations (ug/m3)

Mann Road Washington Park E. 75th St. W 18th St. E. Michigan St.

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 particles 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 five fine particles 

monitors in Central Indiana were broken down into these speciated constituents of fine particles 

34
emissions. The percent change from the observed speciated data in 2005 to the future year 

modeled results for 2009 are listed in Table 7.3. 

Table 7.3 

LADCO’s Round 5 SMAT Modeling Results for Central Indiana 

(Percent decrease from observed to modeled concentrations) 

Species of PM2.5 2009 

Sulfates 23% - 26% 

Nitrates 0% - 6% 

Organic Carbon 0% - 3% 

Elemental Carbon 17% 

Ammonium 16% - 19% 

Particle Bound Water 19% - 24% 

The results show that sulfate, ammonium, elemental carbon and particle bound water 

concentration decreases are projected to be at least 16% in the year 2009. Lesser nitrate 

reductions are projected to occur, up to 6%, with organic carbon reductions occurring up to 3%. 

LADCO modeling shows good performance for sulfates and elemental carbon predicted baseline 

concentrations, slight over-prediction 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 

Central Indiana. 

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 E. Michigan 

Street fine particles monitor in Marion County. Indiana was the biggest regional contributor to 

the E. Michigan Street fine particles monitor with Ohio, the VISTAS Regional Planning 

Organization (Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, 

Tennessee, Virginia and West Virginia) and Illinois also contributing. The PSAT modeling 

results show the majority of Indiana’s emission sector contributions come from ammonium 

emission sources, mobile, EGUs, off-road (including marine, aircraft and railroad), area and nonEGU sources. Other regional contributions result mainly from EGU emissions. Ammonia 

represents primarily the agricultural contribution. 

Chart 7.1 

Regional/Emission Sector PSAT Results at E. Michigan St. 

35
Chart 7.2 shows the modeled pollutant contributions on the E. Michigan Street fine particles 

monitor. The PSAT modeling results show the majority of Indiana’s pollutant contributions 

come from ammonium, nitrate, sulfate, elemental carbon, primary fine particulates and organic 

carbon. Pollutant contributions from other regions consist mainly of sulfates and nitrates. 

Chart 7.2 

Regional/Pollutant PSAT Results at E. Michigan St. PM2.5 Monitor 

The following pie charts depict the species contributions to fine particles concentrations at the 

Central Indiana monitors. The pie charts include both the observed 2005 contributions and year 

36
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 7.3 through 7.7 cover the five fine particles monitors in the Central Indiana area that are 

used to determine compliance with the annual NAAQS. 

Chart 7.3 

Pie Charts - Species Modeled Contributions to W. 18th St. PM2.5 Monitor 

(Base Year Modeled Concentrations = 15.6 μg/m3) (Future Year Modeled Concentrations =13.2 μg/m3) 

2005 Modeled Contributions at W. 18th St. PM2.5 Monitor

so4

33%

no3

10%

oc

22%

ec

4%

soil

3%

nh4

14%

pbw

11%

blan

3%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions at W. 18th St. 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

Chart 7.4 

Pie Charts - Species Modeled Contributions to Washington Park PM2.5 Monitor 

(Base Year Modeled Concentrations = 14.7 μg/m3) (Future Year Concentrations =12.6 μg/m3) 

2005 Modeled Contributions at Washington Park PM2.5 Monitor

so4

32%

no3

11%

oc

22%

ec

4%

soil

3%

nh4

14%

pbw

11%

blan

3%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions at Washington Park PM2.5 Monitor

so4

28%

no3

12%

oc

25%

ec

4%

soil

4%

nh4

13%

pbw

10%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

Chart 7.5

Pie Charts - Species Modeled Contributions to E. 75th St. PM2.5 Monitor 

37
(Base Year Modeled Concentrations = 14.2 μg/m3

) (Future Year Modeled Concentrations =12.3 μg/m3) 

2005 Modeled Contributions at E. 75th St. PM2.5 Monitor

so4

31%

no3

11%

oc

23%

ec

4%

soil

3%

nh4

13%

pbw

11%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions at E. 75th St. PM2.5 Monitor

so4

28%

no3

12%

oc

25%

ec

4%

soil

4%

nh4

13%

pbw

10%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

Chart 7.6 

Pie Charts of the Species Modeled Contributions to Mann Road PM2.5 Monitor 

(Base Year Modeled Concentrations = 13.7 μg/m3) (Future Year Modeled Concentrations =11.9 μg/m3) 

2005 Modeled Contributions to Mann Road PM2.5 Monitor

so4

32%

no3

10%

oc

22%

ec

4%

soil

3%

nh4

14%

pbw

11%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

2009 Modeled Contributions to Mann Road PM2.5 Monitor

so4

28%

no3

12%

oc

25%

ec

4%

soil

4%

nh4

13%

pbw

10%

blan

4%

so4

no3

oc

ec

soil

nh4

pbw

blan

Chart 7.7 

Pie Charts of the Species Modeled Contributions to E. Michigan St. PM2.5 Monitor 

(Base Year Modeled Concentrations = 15.4 μg/m3) (Future Year Modeled Concentrations =13.2 μg/m3) 

2005 Modeled Contributions at E. Michigan St. 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 E. Michigan St. 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

Results of the Round 5 PSAT modeling for Marion County 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 

38
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. Five main types of pollutants contribute to fine particles concentrations: direct 

PM2.5 emissions; sulfur dioxide; nitrogen oxides; ammonia; and volatile organic compounds. 

However, the effect of reducing emissions of each of these pollutants varies by area, depending 

on the fine particles composition, emission levels, and other area-specific factors. Therefore, for 

the Central Indiana Area, following final U.S. EPA policies, PM2.5 direct emissions (including 

organic carbon, elemental carbon and crustal material), sulfur dioxide, and nitrogen oxides must 

be evaluated for emission reduction measures. Neither Indiana nor U.S. EPA have determined 

that VOCs or ammonia contribute significantly to PM2.5 concentrations in the area and need to 

have control measures evaluated. 

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 would bring the Central 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 the Clean Air Interstate Rule 

with and without has shown that future year design values for the Central Indiana Area 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, based 

on current design values, show that the Central Indiana Area will attain the annual NAAQS for 

fine particles without additional national emission controls. Future national and local emission 

control strategies will ensure that the Central Indiana fine particles attainment area will be 

maintained with an increasing margin of safety over time. 

7.5 Meteorological Analysis for Central 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 the 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 Central Indiana Area. 

7.6 Surface Air Conditions Present During High Fine Particles Concentration Days

Higher annual concentrations of fine particles tend to correlate with warmer temperatures and 

lighter wind speeds, although high fine particles episodes can occur in the summer or winter. It 

should be noted that higher annual fine particles concentrations are driven by individual days 

with higher fine particles concentrations throughout the monitored year. Therefore, it is difficult 

to attribute higher fine particles concentrations to annualized meteorological rankings. Review 

of several of the higher fine particles concentration episodes over the past few years shows 

conditions were hot in the summer with temperatures in the middle 80o

s F 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 and humidity was higher. 

39
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. 

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 

particles concentrations to meteorological conditions from 1999 – 2004. (Donna Kenski, 2005). 

This type of analysis looks at the meteorological conditions, such as temperature, pressure, wind 

speed, wind direction, relative humidity and dewpoint temperatures at the surface, as well as 

lower 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 warmweather conditions with high dew points, southwest winds and low 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. Emission reductions of sulfates and nitrates appear 

to have the biggest impact on lower future year fine particle concentrations. 

7.9 Summary of Air Quality Index Days in Central Indiana

Another analysis was conducted to review the daily fine particle concentrations over a year to 

determine the Air Quality Index (AQI) trends. Chart 7.8 below shows by year (2001 through 

2008), the percentage number of days during which fine particles 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 7.8 

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

40
0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2001 2002 2003 2004 2005 2006 2007 2008

Good Moderate USG

Table 7.4 shows how the years ranked for the three AQI ranges. The most days in the “Good” 

concentration range during the 8-year period analyzed (2001-2008) occurred in 2006. The most 

days in the “Moderate” concentration range occurred in 2007 and 2005 had the most days in the 

“Unhealthy for Sensitive Group” concentration range with no days recorded in 2003, 2004, 2006 

and 2008. 

Table 7.4 

Ranking of Highest Number of Days at AQI Levels of Health Concern 

Ranking Good Moderate 

Unhealthy for 

Sensitive Group 

1st 2006 2007 2005 

2nd 2004 2001 2001 

3rd 2008 2002 2002 

4th 2003 2005 2007 

5th 2005 2003 

6th 2002 2008 

7th 2001 2004 

8th 2007 2006 

7.10 Summary of Meteorological Analysis for Central Indiana

41
Annual fine particle concentrations in the Central 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. Upper air weather patterns generally include ridging over the area with 

stagnant conditions at the surface caused by lower mixing heights and stable conditions. 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 above, Indiana commits to review and revise, as appropriate, its 

Maintenance Plan eight years after redesignation, as required by Section 175A of the CAA.

8.2 Commitment for Contingency Measures

Indiana will monitor fine particles concentrations to determine whether trends indicate higher 

values or whether emissions appear to be increasing. If it is determined that fine particles levels 

and emissions are increasing and action is necessary to reverse that trend, Indiana will take 

action to reverse the noted trend, prior to a violation of the standard occurring. 

Indiana 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 close of the fine particles season that prompted the 

Action Level. 

Control Measure Selection and Implementation

42
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, Indiana 

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 below 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 particles 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 outlined below is not comprehensive. Indiana anticipates that if 

contingency measures 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 controls on new minor sources (less than 100 tons). 

3) Wood stove change out program. 

4) Idle restrictions. 

5) Broader geographic applicability of existing measures. 

6) 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 affected state and local governments deem 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. 

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9.0 PUBLIC PARTICIPATION

Indiana published notification for a public hearing and solicitation for public comment 

concerning the draft Redesignation Petition and Maintenance Plan in the Indianapolis Star on 

August 14, 2009. 

A public hearing to receive comments concerning the redesignation request was conducted on 

September 14, 2009 at the Indianapolis-Marion County Library-West Indianapolis Branch in 

Indianapolis, Indiana. IDEM received one written comment. The public comment period closed 

on September 18, 2009. Appendix J includes a copy of the public notice, certifications of 

publication, the transcript from the public hearing, copies of all written comments received, and 

a summary of all comments received that includes IDEM’s responses, as applicable. 

10.0 CONCLUSIONS 

The Central Indiana Area has attained the annual NAAQS for fine particles. This petition 

demonstrates that the Central 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 reductions following 

implementation of 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 SO2 and NOx emissions will continue to decline, thus ensuring that the 

area continues to maintain compliance with the standard and provide for an increased margin of 

safety. Based on this presentation, the Central Indiana Area 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 

Central Indiana Area be redesignated to attainment for the annual fine particles standard 

simultaneously with U.S. EPA approval of this Indiana State Implementation and Maintenance 

Plan provisions contained.