Georgia's Redesignation Request and 

Maintenance Plan for the Macon Nonattainment 

Area for the 1997 PM2.5 NAAQS 

May 31, 2012 

Prepared by:

Georgia Department of Natural Resources 

Environmental Protection Division 

Air Protection Branch 
Executive Summary 

This document contains Georgia's request under the Clean Air Act Amendments of (CAA) of 1990 that 

the Macon nonattainment area be redesignated to attainment with respect to the annual National Ambient 

Air Quality Standard (NAAQS) for PM2.5 (1997 fine particulate matter standard, retained in 2006). The 

document also includes Georgia’s plan to maintain attainment of the PM2.5 standard in the Macon area. 

This request is based on three years, 2007-2009, of ambient monitoring data showing attainment of the 

standard (15.0 μg/m3

) consistent with the clean data policy memo (Stephen Page 12/14/2004); the 

implementation of permanent and enforceable reductions in PM2.5 and PM2.5 precursor emissions; 

compliance with all applicable requirements; and the Macon Maintenance Plan with projections 

demonstrating maintenance of the standard through the year 2023. 
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TABLE OF CONTENTS 

1.0 Introduction ................................................................................................................. 1

1.1 Nonattainment Designation and Attainment Demonstration .......................................... 1

1.2 Redesignation Request ........................................................................................................ 2

1.3 Maintenance Plan ................................................................................................................ 3

2.0 Redesignation Request ................................................................................................. 4

2.1 Attainment of the Annual PM2.5 NAAQS .......................................................................... 4

2.1.1 Monitoring Network ........................................................................................................................ 4

2.1.2 Ambient PM2.5 Data ........................................................................................................................ 7

2.1.3 Clean Data Determination ............................................................................................................... 7

2.2 Implementation Plan Under Section 110(k) ...................................................................... 7

2.3 Permanent and Enforceable and Other Reductions in Emissions .................................. 8

2.3.1 Source Apportionment of Ambient PM2.5 ....................................................................................... 8

2.3.2 State Control Measures - Georgia ................................................................................................. 10

2.3.2.1 SO2 and NOx Controls and SO2 Limits ................................................................................. 11

2.3.2.2 Smoke Management Plan ..................................................................................................... 16

2.3.3 Federal Control Measures ............................................................................................................. 18

2.3.3.1 Clean Air Interstate Rule ...................................................................................................... 19

2.3.3.2 Tier 2 Vehicle Standards and low-sulfur gasoline ................................................................ 19

2.3.3.3 Heavy-Duty Gasoline and Diesel Highway Vehicles Standards & Ultra Low-Sulfur Diesel 

Rule ........................................................................................................................................ 20

2.3.3.4 Large Nonroad Diesel Engines Rule & Ultra Low-Sulfur Diesel Rule ................................ 20

2.3.3.5 Nonroad Large Spark-Ignition Engines and Recreational Engines Standard ....................... 20

2.3.3.6 NOx SIP Call in Surrounding States ..................................................................................... 21

2.3.4 SO2 Emissions Reductions in Upwind States ................................................................................ 21

2.4 Section 110 and Part D Requirements ............................................................................. 23

3.0 Maintenance Plan ...................................................................................................... 24

3.1 Maintenance Demonstration ............................................................................................ 24

3.1.1 Attainment Year Emissions Inventory .......................................................................................... 24

3.1.1.1 Point Sources ........................................................................................................................ 26

3.1.1.2 Nonpoint Sources ................................................................................................................. 27

3.1.1.3 Onroad Mobile Sources ........................................................................................................ 28

3.1.1.4 Nonroad Mobile Sources ...................................................................................................... 29

3.1.1.5 Summary of 2007 Emissions Inventory ............................................................................... 29

3.1.2 Projected Emissions Inventories ................................................................................................... 30

3.1.2.1 Methods and Projected Inventories ...................................................................................... 30

3.1.2.2 Point Sources ........................................................................................................................ 31

3.1.2.3 Nonpoint Sources ................................................................................................................. 33

3.1.2.4 Onroad Mobile Sources ........................................................................................................ 35

3.1.2.5 Nonroad Mobile Sources ...................................................................................................... 36

3.1.3 Emissions Projections Summary and Demonstration of Maintenance of Attainment ................... 37

3.1.4 Emissions Decreases ..................................................................................................................... 37

3.1.5 Verification of Continued Attainment ........................................................................................... 38

3.2 Contingency Provisions ..................................................................................................... 38

3.2.1 Contingency Measure Triggers ..................................................................................................... 38

3.2.2 Schedule and Procedure for Adoption and Implementation of Contingency Measures ............... 39
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3.2.3 Contingency Measures .................................................................................................................. 40

4.0 Motor Vehicle Emissions Budget ............................................................................... 42

4.1 Pollutants ........................................................................................................................... 42

4.2 Methodology ...................................................................................................................... 43

4.3 Motor Vehicle Emissions Budgets and Safety Margins.................................................. 44

5.0 Conclusion ................................................................................................................. 45

6.0 References .................................................................................................................. 48
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LIST OF FIGURES 

Figure 1-1. PM2.5 Nonattainment Areas in Georgia ........................................................................ 1

Figure 2-1. Locations of PM2.5 Monitors in the Macon Nonattainment Area ............................... 6

Figure 2-2: Average factor contributions for 2003-04 at the Atlanta, Floyd County, and Macon 

STN sites using PMF ................................................................................................................... 9

Figure 2-3. Locations and 2007 Energy Production of Coal-fired EGU Facilities in North 

Georgia ....................................................................................................................................... 13

Figure 2-4. SO2 Emissions and Generation from North Georgia Coal-fired EGU Facilities, 

2003 - 2009 ................................................................................................................................. 16

Figure 2-5. Trend of Aggregated Annual SO2 Emissions in States With Downwind 

Contributions to Georgia PM2.5 Exceeding 0.15 μg/m3

 .......................................................... 23
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LIST OF TABLES 

Table 1-1. PM2.5 Design Values for Macon ....................................................................................... 2

Table 2-1. Macon PM2.5 Data Collection Sites ................................................................................. 5

Table 2-2. Annual and Three-year Average Ambient PM2.5 Concentrations................................. 7

Table 2-3. Average factor contributions to PM2.5 (g/m3

) for 2003-04 at the Atlanta, Floyd 

County, and Macon STN sites using PMF .............................................................................. 10

Table 2-4. Timetable of State Measure Implementation ............................................................... 11

Table 2-5. Annual SO2 Emissions and Generation (106 MWh) from North Georgia Coal-fired 

EGU Facilities, 2003 – 2009 ...................................................................................................... 15

Table 2-6. Timetable of Federal Measure Implementation .......................................................... 18

Table 2-7. Annual SO2 Emissions in States With Downwind Contributions to Georgia PM2.5

Exceeding 0.15 μg/m3

 ................................................................................................................ 22

Table 3-1. 2007 Emissions Inventory Sources ................................................................................ 25

Table 3-2. Point Source Emissions for 2007 (tons, annual) ........................................................... 26

Table 3-3. Non-EGU Point Source Emissions for 2007 (tons, annual) ......................................... 26

Table 3-4. Nonpoint Source Emissions for 2007 (tons, annual) .................................................... 27

Table 3-5. Largest Nonpoint PM2.5 Emissions by Source Classification ...................................... 28

Table 3-6. Onroad Mobile Source Emissions for 2007 (tons, annual) .......................................... 28

Table 3-7. Nonroad Mobile Source Emissions for 2007 (tons, annual) ....................................... 29

Table 3-8. Attainment-year (2007) Emissions Inventory (tons, annual) ...................................... 30

Table 3-9. Bases of Control and Growth Factors for 2017 and 2023 Inventories ....................... 31

Table 3-10. Projected Point Source Emissions (tons) .................................................................... 32

Table 3-11. Non-EGU Point Source Emissions for 2023 (tons, annual) ....................................... 33

Table 3-12. Projected Nonpoint Source Emissions (tons) ............................................................. 34

Table 3-13. Largest Nonpoint PM2.5 Emissions by Source Classification, Year 2023 ................. 34

Table 3-14. Projected Onroad Mobile Source Emissions (tons) ................................................... 35

Table 3-15. Projected Nonroad Mobile Source Emissions (tons) ................................................. 36

Table 3-16. Projected Emissions – Total of All Sectors (tons) ....................................................... 37

Table 3-17. Emissions Decrease ....................................................................................................... 37

Table 4-1. 2023 Motor Vehicle Emissions, Emissions Budgets, and Safety Margins .................. 44

Table 5-1. Summary of Projected SO2 Emissions – Total of All Sectors (tons) ........................... 45

Table 5-2. Summary of Projected NOx Emissions – Total of All Sectors (tons) .......................... 46

Table 5-3. Summary of Projected PM2.5 Emissions – Total of All Sectors (tons) ........................ 46
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LIST of APPENDICES 

Appendix A Source Apportionment of PM2.5 in Georgia 

Appendix B Georgia’s Basic Smoke Management Plan and Memorandum of Understanding 

Appendix C Emissions Inventory Development for the Macon Area 

Appendix C-1 Development of the Point Source Emissions Inventory for 2007 in the SESARM 

Region (Version 1.8), January 26, 2011 

Appendix C-2 Area and Nonroad 2007 Base Year Inventories, Final Report, June 2010 

Appendix C-3 Mobile Source Emissions Modeling for Macon Nonattainment Area PM2.5

Maintenance Plan Motor Vehicle Emissions Budget 

Appendix C-4 The Travel Demand Model for the Macon Area 

Appendix C-5 Growth and Control Factors for Aircraft, Commercial Marine Vessel, and 

Locomotive Emissions (includes memorandum from K. Thesing and two 

spreadsheets) 

 

Appendix C-6 Documentation of the 2012 Projection Emission Inventory (VISTAS) 

Appendix C-7 Growth Factors for Nonpoint Sources and Non-EGU Point Sources 

Appendix C-8 MACTEC, August 2009. Point Source, On-road, and Fire Base Year, Future Year, 

and Control Strategy Emissions Inventories Draft Quality Assurance Project Plan. 

 

Appendix C-9 E.H. Pechan and Associates, July 29, 2009. Quality Assurance Project Plan for Nonroad and Area Source Base Year and Future Year Emissions Inventories. 
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List of Acronyms 

Acronym Meaning Acronym Meaning 

AEO Annual Energy Outlook FGD Flue Gas Desulfurization 

AERR Annual Emissions Reporting 

Requirements 

FR Federal Register 

AIRS Aerometric Information Retrieval 

System 

FRM Federal Reference Method 

AQS Air Quality Subsystem GDOT Georgia Department of 

Transportation 

CAA Clean Air Act GFC Georgia Forestry Commission 

CAIR Clean Air Interstate Rule HC Hydrocarbon 

CARB California Air Resources Board HPMS Highway Performance Monitoring 

System 

CERR Consolidated Emissions Reporting 

Rule 

ICI Industrial and 

Commercial/Institutional 

CFR Code of Federal Regulations MATS Macon Area Transportation Study 

CO Carbon Monoxide MOU Memorandum of Understanding 

CSAPR Cross-state Air Pollution Rule MOVES Motor Vehicle Emissions Simulator 

DNR Department of Natural Resources MPO Metropolitan Planning Organization 

DOT Department of Transportation MVEB Motor Vehicle Emissions Budget 

EGAS Economic Growth Analysis System MWe Megawatt Electrical 

EGU Electric Generating Unit MWh Megawatt Hours 

EPA Environmental Protection Agency NAA Nonattainment Area 

EPD Environmental Protection Division NAAQS National Ambient Air Quality 

Standard 

ERTAC Eastern Regional Technical Advisory 

Committee 

NCD NMIM County Database 
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Acronym Meaning Acronym Meaning 

NEI National Emissions Inventory SCR Selective Catalytic Reduction 

NMIM National Mobile Inventory 

Model 

SEMAP Southeastern Modeling Analysis Plan 

NTE Not-To-Exceed SIP State Implementation Plan 

NOx Nitrogen Oxides SMP Smoke Management Plan 

OAQPS Office of Air Quality 

Planning and Standards 

SO2 Sulfur Dioxide 

PM Particulate Matter SOA Secondary Organic Aerosols 

PM2.5 Fine Particulate Matter STN Speciated Trends Network 

PMF Positive Matrix Factorization tpy tons per year 

Ppm parts per million SUV Sport Utility Vehicle 

RACM Reasonably Available Control 

Measures 

ULSD Ultra-Low Sulfur Diesel 

RACT Reasonably Available Control 

Technology 

VISTAS Visibility Improvement State and Tribal 

Association of the Southeast 

RFP Reasonable Further Progress VMT Vehicle Miles Traveled 

SCC Source Classification Code WRD Wildlife Resources Division 
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1.0 Introduction 

This document contains the technical support for the Georgia Environmental Protection Division's 

(EPD) request that the Macon nonattainment area be redesignated as an area attaining the 1997 

annual fine particulate matter (PM2.5) National Ambient Air Quality Standard (NAAQS) pursuant to 

Sections 107(d)(3)(D) and (E) of the Clean Air Act (CAA), as amended. This redesignation request 

was prepared in accordance with U.S. EPA Guidance issued in 1992 (memorandum dated September 

4 of that year from John Calcagni1

). 

1.1 Nonattainment Designation and Attainment Demonstration 

In 2005 EPA designated four PM2.5 nonattainment areas in Georgia: Chattanooga (which also 

includes parts of Alabama and Tennessee), Floyd County, Atlanta, and Macon. Figure 1-1 shows 

their locations. The Macon nonattainment area is located in the central portion of the state and 

Figure 1-1. PM2.5 Nonattainment Areas in Georgia 

 

1

 “Procedures for Processing Requests to Redesignate Areas to Attainment,” September 4, 1992. John 

Calcagni, Director, Air Quality Management Division, OAQPS, USEPA. 
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southeast of the Atlanta Nonattainment Area. The nonattainment area consists of Bibb County in its 

entirety and a small portion of Monroe County, on its east side. 

EPA made initial designations of nonattainment areas, including the Macon nonattainment area, for 

the 1997 annual PM2.5 NAAQS on January 5, 2005 (70FR944), and amended the designations on 

April 5, 2005 (70FR19844). The observed PM2.5 design value at Macon’s Allied Chemical monitor 

violated the annual standard, as shown in Table 1-1 below. 

Table 1-1. PM2.5 Design Values for Macon 

Site name Monitor ID PM2.5 Design Value 

2001-2003 (μg/m3) 

Allied Chemical (Bibb Co.) 13-021-0007 15.2 

Georgia Forestry (Bibb Co.) 13-021-0012 13.3 

The State of Georgia prepared and submitted a PM2.5 attainment demonstration plan for the Macon 

Nonattainment Area to EPA Region IV on August 17, 2009 (cover date is June 12, 2009). The plan 

was based on modeling of the effects of existing and planned control measures on air quality in 

Macon and demonstrated attainment of the standard by April 5, 2010. Since EPA has determined 

that the area has met the clean data requirements (76FR 31858) and attained the standard prior to the 

attainment date (76FR 55774) (see Section 2), the SIP requirements that the August 17, 2009, 

attainment demonstration was required to fulfill are suspended. The attainment demonstration plan 

has been withdrawn and will be replaced with this maintenance plan. Relief from the requirement to 

submit an attainment demonstration as well as Reasonable Further Progress (RFP), associated 

RACM, and contingency requirements upon clean data determination is specified in 40 CFR 1004(c) 

and also in a December 14, 2004, memo from Stephen D. Page of U.S. EPA. 

1.2 Redesignation Request 

This document contains Georgia's request that the Macon nonattainment area be redesignated to 

attainment with respect to the annual NAAQS for PM2.5 (1997 fine particulate matter standard, 

retained in 2006). Section 107(d) of the CAA states that an area can be redesignated to attainment if 

the following conditions are met: 

1. The EPA has determined that the NAAQS has been attained. 

2. The applicable implementation plan has been fully approved by EPA under Section 110(k). 

3. The EPA has determined that the improvement in air quality is due to permanent and 

enforceable reductions in emissions. 

4. The state has met all applicable requirements for the area under Section 110 and Part D. 

5. The EPA has fully approved a maintenance plan, including a contingency plan, for the area 

as required by CAA Section 175A. 
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The supporting documentation to show that the above conditions have been met is contained in 

Sections 2 and 3. EPA’s approval of this document will satisfy the 5th condition. 

1.3 Maintenance Plan 

The maintenance plan (see above) has two required components under Section 175A: 

 A demonstration of maintenance of the standard for at least ten years after redesignation 

 Contingency provisions for prompt correction of any future violations 

Per EPA guidance2

, the Macon PM2.5 maintenance plan also includes the following elements: 

 An attainment year emissions inventory (to support the maintenance demonstration) 

 A commitment to continued operation of ambient monitoring equipment in the area 

 Verification of continued attainment 

 

The maintenance plan is presented in Section 3. 

 

2

 “Procedures for Processing Requests to Redesignate Areas to Attainment,” September 4, 1992. John 

Calcagni, Director, Air Quality Management Division, OAQPS, USEPA. 
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2.0 Redesignation Request 

As noted in Section 1.2 of this document, Section 107(d) of the CAA states that an area can be 

redesignated to attainment if the following conditions are met: 

1. The EPA has determined that the NAAQS has been attained. 

2. The applicable implementation plan has been fully approved by EPA under Section 110(k). 

3. The EPA has determined that the improvement in air quality is due to permanent and 

enforceable reductions in emissions. 

4. The state has met all applicable requirements for the area under Section 110 and Part D. 

5. The EPA has fully approved a maintenance plan, including a contingency plan, for the area 

under CAA Section 175A. 

This section of the document includes supporting documentation for the following: 

 Attainment of the annual PM2.5 NAAQS based on ambient data from 2007 through 2009 

 Approval by EPA of the implementation plan under Section 110(k). 

 Improvement of air quality with respect to PM2.5 is due to permanent and enforceable 

reductions in emissions. 

 The state has met all applicable requirements for the area under Section 110 and Part D. 

2.1 Attainment of the Annual PM2.5 NAAQS 

A monitoring site is in attainment of the annual PM2.5 standard when the annual standard design 

value is less than or equal to 15.0 micrograms per cubic meter (μg/m3

) per Appendix N of 40 CFR 

Part 50. The annual standard design value is the 3-year average of the annual mean, which is, in 

turn, the average of one year’s 4-calendar-quarter averages. The data must be complete and qualityassured, consistent with 40 CFR part 58 requirements, and other relevant EPA guidance. Therefore, 

for a single site to meet the standard, the annual design value calculated from the previous three 

calendar years must be less than or equal to the standard. For a nonattainment area to achieve 

attainment, all monitoring sites in the nonattainment area must be in attainment. 

 

The Macon design value based on data from 2007 through 2009 is 13.7 μg/m3

, which demonstrates 

attainment of the standard. The monitoring network and ambient PM2.5 data are presented below. 

2.1.1 Monitoring Network 

There are currently two ambient PM2.5 monitoring sites in the Macon nonattainment area, as shown 

in Table 2-1 and Figure 2.1. The Macon-Allied Chemical and Macon-Forestry sites are in Bibb 

County. Providing adequate coverage of the nonattainment area, data from both sites represent a 

neighborhood scale, which extends up to 4.0 kilometers from each monitor. Both of the sites are 

considered to be part of the State and Local Air Monitoring Stations (SLAMS) monitoring network, 

with the monitoring objective of sampling for population exposure. 

 

Two Federal Reference Method (FRM) monitors and one speciation monitor are located at the 

Macon-Allied Chemical site (13-021-0007). The FRM monitors were installed in accordance with 

40 CFR 58. The first FRM monitor has been collecting data since February 2, 1999. Its sampling 

schedule was every three days until March 1, 2007, when the schedule was changed to daily 

sampling. The second FRM monitor has been collecting data since January 5, 2006. The sampling 

schedule of the second FRM monitor was every six days until July 1, 2009, when it changed to every 

twelve days. The speciation monitor has been collecting data since March 3, 2002. The sampling 
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schedule of the speciation monitor is every six days. Speciated data is useful for determining the 

composition of the particulate matter but cannot be used for the purpose of determining attainment 

with the NAAQS. 

One FRM monitor, which has been collecting data since February 11, 1999, is located at the MaconForestry site (13-021-0012). Its sampling schedule has been and remains every three days. There is 

no speciation monitor at the Macon-Forestry site. 

 

Table 2-1. Macon PM2.5 Data Collection Sites 

Site 

Name 

AQS* 

Site 

ID 

Start Date– 

FRM Data 

Collection 

End DateFRM Data 

Collection 

Start Date – 

Speciation Data 

Collection 

End DateSpeciation 

Data 

Collection 

MaconAllied 

Chemical 

13-

021-

0007 

Monitor 1 – Feb. 2, 

1999 

Monitor 2 – Jan. 5, 

2006 

NA March 3, 2002 NA 

MaconForestry 

13-

021-

0012 

February 11, 1999 NA NA NA 

* EPA’s Air Quality System 

NA – not applicable 
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Figure 2-1. Locations of PM2.5 Monitors in the Macon Nonattainment Area 
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2.1.2 Ambient PM2.5 Data 

Table 2-2 shows the annual average PM2.5 concentrations and the associated three-year average that 

demonstrate attainment of the standard in Macon. Data are presented for the Macon-Allied 

Chemical site (0007) and the Macon-Forestry site (0012). The 2007 – 2009 three-year design value 

is 13.7 μg/m3

, which is below the standard of 15.0 μg/m3. The table includes annual averages from 

2003 through 2010, demonstrating the downward trend in the measured ambient PM2.5 level in the 

nonattainment area. The annual average PM2.5 concentration for 2010 at the Allied Chemical site 

was 13.7 μg/m3

. This provides continued evidence that the area is meeting the standard. To date the 

quality-assured annual average for 2011 is not available. 

Table 2-2. Annual and Three-year Average Ambient PM2.5 Concentrations 

Site Ambient PM2.5 Concentration (μg/m3)

2003 2004 2005 2006 2007 2008 2009 2010 2007 – 

2009

0007 14.8 16.8 16.7 16.9 16.7 12.3 12.2 13.7 13.7 

0012 12.9 14.3 14.3 14.1 13.2 12.1 10.6 11.4 12.0 

* Source of 2007 through 2009 data is USEPA’s Technical Support Document, March 2011, Docket 

No. EPA-R04-OAR-2011-0055 

2.1.3 Clean Data Determination 

On June 2, 2011, EPA promulgated its determination (76 FR 31858) that the Macon nonattainment 

area had attained the 1997 annual average PM2.5 National Ambient Air Quality Standard (NAAQS). 

This determination was based upon quality-assured and certified ambient air monitoring data for the 

2007-2009 period which showed a design value of 13.7 μg/m3 [FR lists design value as 13.3 μg/m3

, 

which appears to be an error]. With the clean data determination, EPA suspended the requirements 

for the nonattainment area to submit an attainment demonstration, a reasonable further progress 

(RFP) plan, associated RACM, and contingency measures. These requirements are suspended as 

long as the area continues to attain the standard. This final rule became effective on July 5, 2011. 

2.2 Implementation Plan Under Section 110(k) 

Section 110(k) of the CAA addresses EPA’s actions on state implementation plan submittals 

(completeness, deadline for action by EPA, etc.). A September 4, 1992, memo from John Calcagni 

of EPA states the following: 

“The SIP for the area must be fully approved under section 110(k), and must satisfy all requirements 

that apply to the area. It should be noted that approval action on SIP elements and the redesignation 

request may occur simultaneously.” 

The State of Georgia has prepared and submitted a PM2.5 attainment demonstration plan for the 

Macon Nonattainment Area. The plan was submitted for approval to EPA Region IV on August 17, 

2009. As discussed in section 1.2 of this redesignation request and maintenance plan, the 

attainment demonstration, RFP, associated RACM, and contingency requirements that the August 17, 

2009, SIP revision was required to fulfill have been suspended. Therefore the attainment 

demonstration has been withdrawn and substituted with submittal of this maintenance plan. 

Therefore there are no longer any Section 110(k) requirements to be met. 
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2.3 Permanent and Enforceable and Other Reductions in Emissions 

In order for the nonattainment area to be redesignated to attainment, the State must demonstrate (and 

EPA must determine) that the improvement of ambient PM2.5 concentrations during the years 2007 

through 2009 is due to permanent and enforceable reductions in emissions that were implemented 

following the nonattainment design value period (2001–2003). This subsection contains Georgia 

EPD’s demonstration that the improved air quality is due to permanent and enforceable emissions 

reductions. The elements of the demonstration described below are as follows: 

 Source apportionment, which links individual observed ambient PM2.5 species to specific 

emissions sources 

 State control measures and associated emissions reductions 

 Federal control measures and associated emissions reductions 

 Reductions in SO2 emissions from upwind states 

2.3.1 Source Apportionment of Ambient PM2.5 

Source apportionment of speciated ambient pollutant measurements is an important tool for the 

prioritization of pollutant control strategies. Presented here are source-apportionment results for 

2003-2004 speciated PM2.5 measurements in the Atlanta, Floyd County, and Macon areas (Figure 2-2 

and Table 2-3). The source-apportionment results are based on Positive Matrix Factorization (PMF), 

a factor analytic method that distinguishes correlation patterns among speciated PM2.5 measurements 

in a given location. More detailed information on source apportionment is presented in Appendix A. 

The similarities between the PMF results for the three sites show the regional nature of PM2.5. The 

major impacting factors at all sites are secondary sulfates, secondary organic aerosols (SOA), mobile 

sources, and biomass burning. The Atlanta area, as expected, has higher levels of mobile-source 

PM2.5, compared to Floyd County and Macon. On the other hand, these latter two sites exhibit 

higher levels of soil dust, and the Macon site exhibits a relatively high contribution of Lime/Minerals 

PM2.5. This is likely due to local sources in the industrial area where the site is located. 
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0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

Atlanta Floyd county Macon

ug/m3

Unspec.

SOA

Sec. Nitrate

Sec. Sulfate

Zn-rich

Cu-rich

Road-dust

Oil burning

Na-rich

Lime/Minerals

Soil

Biomass burning

Mobile-sources

Figure 2-2: Average factor contributions for 2003-04 at the Atlanta, Floyd County, and 

Macon STN sites using PMF 

These results are useful for an assessment of control strategies. Secondary sulfate at the Macon site 

makes up approximately 4.7 μg/m3

 (28 %) of ambient PM2.5, the largest contribution of all of the 

factors. SOAs make up the next largest contribution at 23 %. The contribution of secondary nitrate 

is only one-sixth of the contribution of sulfate. Contributions from all other source-categories were 

small in general, though the Macon and Rome sites seem to be affected by local sources related to 

lime/minerals processing and soil dust re-suspension. 

Secondary sulfates are formed in the atmosphere from SO2 emissions. As the sulfate fraction is the 

largest fraction of ambient PM2.5, it is evident that controlling SO2 emissions (generated primarily by 

coal-burning EGUs) would reduce PM2.5 levels throughout the state. Secondary nitrates are 

associated with NOx emissions from combustion, primarily combustion in EGUs and in on-road 

mobile sources. SOAs are associated with biogenic emissions (natural emissions from living trees 

and other vegetation). It is not practical to control biogenic emissions. Biomass burning generates 

elemental carbon (soot) and is associated with wildfires, prescribed burning, and wood-fired boilers. 

In addition to NOx, mobile sources generate elemental carbon. 
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Table 2-3. Average factor contributions to PM2.5 (g/m3) for 2003-04 at the Atlanta, 

Floyd County, and Macon STN sites using PMF 

Factor Atlanta Floyd County Macon 

Unspecified 2.32 2.97 1.81 

SOA 2.55 3.46 3.81 

Sec. Nitrate 0.99 1.05 0.74 

Sec. Sulfate 4.82 5.10 4.67 

Zn-rich 0.03 0.03 0.03 

Cu-rich 0.07 0.03 0.02 

Road-dust 0.12 0.13 0.11 

Oil burning 0.03 0.04 0.04 

Na-rich 0.43 0.42 0.33 

Lime/Minerals 0.05 0.24 0.59 

Soil 0.29 0.61 0.67 

Biomass burning 1.06 1.31 1.50 

Mobile sources 2.78 1.61 2.12 

TOTAL 15.5 17.0 16.4 

2.3.2 State Control Measures - Georgia 

Based on source factor analysis, Georgia’s control strategy is focused on the reduction of emissions 

associated with secondary sulfates and nitrates, biomass burning, and mobile sources. Control of 

SO2 is the most important component of the strategy, as secondary sulfates make up the largest 

controllable contribution to ambient PM2.5. State measures that target reduction of these emissions 

are: 

 SO2 and NOx controls on EGUs (rule (sss)) 

 SO2 limits on EGUs (Rule (uuu)) 

 Smoke Management Plan 
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Table 2-4 shows the timetable of implementation of these measures as well as the species controlled 

by each. The correlation between the drop in PM2.5 annual averages and the implementation of the 

control measures, particularly Georgia Rule 391-3-1-.02(2)(sss), lends strong evidence that the 

improvements in air quality are a result of reduction in emissions and not a meteorological 

influenced phenomenon. Detailed discussions of the measures are presented in the following 

subsections. 

Table 2-4. Timetable of State Measure Implementation 

Measure Species 

controlled 

2001 ‘02 ‘03 ‘04 ‘05 ‘06 ‘07 ‘08 ‘09 ‘10 

PM2.5 ann. 

avg. (μg/m3), 

Macon – 

Allied 

Chemical 

 16.1 14.8 14.8 16.8 16.7 16.9 16.7 12.3 12.2 13.7 

Rule (sss) SO2, NOx * 

Smoke 

Management 

Plan 

PM, NOx 

Rule (uuu) SO2 

* Controls were required on December 31, 2008, but were actually started up in the first half of the 

year. 

2.3.2.1 SO2 and NOx Controls and SO2 Limits 

Atmospheric secondary sulfate is formed from emissions of SO2. Coal-fired EGUs are by far the 

most significant source of SO2 emissions in Georgia and in the Southeast. Georgia’s Multipollutant 

Rule (391-3-1-.02(2)(sss)) requires flue gas desulfurization (FGD) and selective catalytic reduction 

(SCR) controls on the majority of coal-fired EGUs in Georgia. This state enforceable rule was 

promulgated in 2007 for the purposes of lowering ozone and PM2.5 concentrations by controlling 

precursor emissions and reducing mercury deposition. The FGD controls reduced SO2 emissions 

rates from the affected emissions units by at least 95 percent and the SCR controls reduced NOx

emissions rates by approximately 85 percent. The SO2 and NOx controls were required in support of 

EPA’s CAIR rule, which was promulgated in 2005 and required state-wide caps for NOx and SO2

beginning in 2009 and 2010, respectively. The CAIR rule is discussed further in Section 2.3.3. 

Georgia Rule (uuu), SO2 Emissions from Electric Utility Steam Generating Units, is a companion 

rule to Rule (sss) and is both state and federally enforceable upon approval by EPA. Both of these 

rules were implemented in response to CAIR and require emissions reductions consistent with 

CAIR’s original schedule starting in 2009. The rule requires 95% reduction of SO2 emissions from 
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the majority of Georgia’s coal-fired EGUs, with the requirement being phased in from 2010 through 

2016. It requires 95% reduction of SO2 emissions from all four EGUs at Plant Scherer and will be 

phased in on individual units between 2011 and 2015. 

It has been well demonstrated that ambient secondary sulfate in a given location can be significantly 

affected by SO2 emissions from distant sources. Therefore, secondary sulfate in Macon is due not 

only to SO2 emissions from Plant Scherer, located inside the nonattainment area, but also to SO2

emissions from other coal-fired EGUs in north Georgia. Figure 2-3 shows the locations of the coalfired EGU facilities in the northern half of Georgia as well as their respective energy production (in 

million megawatt-hours) in the year 2007. Plant Bowen, located in Bartow County, was a close 

second to Plant Scherer in energy production and historically has been by far the highest SO2-

emitting facility in the state. The facilities shown in the figure comprise seven of the ten coal-fired 

EGU facilities that were operated in Georgia in 2007. In 2007, the energy produced by the seven 

facilities made up 97 percent of the state-wide energy production from coal-fired facilities. 
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Figure 2-3. Locations and 2007 Energy Production of Coal-fired EGU Facilities 

in North Georgia 

The required FGD control implementation date varies by EGU, starting on December 31, 2008. SO2

controls were actually started on five units in May 2008. SO2 controls were operating for the entire 

year of 2009 as follows: 

 Plant Hammond – controls on 4 of 4 units 

 Plant Bowen – controls on 2 of 4 units 

 Plant Wansley – controls on 1 of 2 units 
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SO2 controls on a third unit at Plant Bowen and the second unit at Plant Wansley began operation on 

April 1, 2009. 

Rule (sss) requires SCR controls to be operated year-round, starting at six EGUs in 2008 and 2009 

(Bowen Units 2, 3, and 4; Wansley Units 1 and 2; Hammond Unit 4). However, these NOx controls 

were already in place and operating during the ozone season by the end of 2003. The Title V permit 

of each of the above facilities has been amended to permit operation of the FGD and SCR controls. 

Table 2-5 shows the annual SO2 emissions for Plant Scherer and the other six coal-fired facilities in 

north Georgia for the period 2003 through 2009. The table also includes the electrical generation, a 

measure of production, for the facilities for the same time period. This data is presented in graphical 

form in Figure 2-4. 

For the seven facilities, SO2 emissions were reduced by 50.4 percent and generation was down by 

only 4.5 percent. These statistics provide clear evidence that the reduction in PM2.5 concentration is 

due to permanent and enforceable controls rather than to reduced generation. 

Plant Scherer operates four coal-fired EGUs. All four of the EGUs burn Powder River Basin (PRB) 

coal, which is lower in both sulfur and BTU value than Appalachian coal. The sulfur levels in the 

PRB coal, as measured in 2007, were 0.285%, whereas the Georgia Power system-wide average was 

1.12% over the same time period. Rule (sss) requires operation of SO2 and NOx controls on all four 

of Scherer’s EGUs, but the timing of the requirement is after the 2007 – 2009 attainment 

demonstration period. It should be noted, however, that the average annual SO2 emissions from 

Plant Scherer for the period 2007 through 2009 was 74,600 tons, a 9 percent decrease from the 

average for the period 2003 through 2005 (average of 82,200 tons). Power generation from the plant 

was higher during the 2007-to-2009 period. 
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Table 2-5. Annual SO2 Emissions and Generation (106 MWh) from North Georgia 

Coal-fired EGU Facilities, 2003 – 2009 

Facility 2003 2004 2005 2006 2007 2008 2009 

Hammond SO2 (tpy) 35900 37700 39500 40600 47800 12500* 900*

 generation 4.79 4.11 4.64 4.27 5.09 4.32 3.73

Bowen SO2 (tpy) 164900 165900 186500 206400 196800 148100* 54800*

 generation 21.9 21.9 23.3 23.7 24.0 23.4 22.9

Branch SO2 (tpy) 64800 70100 90500 96000 98400 94000 60100

 generation 8.28 7.97 10.3 10.8 10.9 10.7 6.82

McDonough SO2 (tpy) 23900 22700 27700 28800 28500 24300 15900

 generation 3.75 3.52 3.92 4.07 4.07 3.43 2.34

Scherer SO2 (tpy) 83900 79700 82900 74200 76500 77700 69500

 generation 21.3 24.6 25.5 24.5 26.5 25.7 24.3

Wansley** SO2 (tpy) 94000 99000 101500 96200 93900 74300* 7400*

 generation 13.7 14 15.1 14.8 16.1 15.5 11.8

Yates SO2 (tpy) 44900 50600 66500 75500 77200 68200 45500

generation 6.73 6.22 7.37 7.49 8.10 7.37 4.90

TOTAL 

SO2 Tons/yr 512300 525700 595100 617700 619100 499100 254100

TOTAL 

Generation 106

 MWh 80.45 82.32 90.13 89.6 94.76 90.42 76.79

Ambient 

PM2.5, 

Macon area 

annual 

avg 

(ug/m3)

14.8 16.8 16.7 16.9 16.7 12.3 12.2 

Source: EPA Clean Air Markets Division 

* SO2 control, required by Georgia Rule (sss), was operational on one or more EGUs for partial or 

full year 

** does not include emissions from facility’s gas-fired units 
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0

100000

200000

300000

400000

500000

600000

700000

2003 2004 2005 2006 2007 2008 2009

0

10

20

30

40

50

60

70

80

90

100

SO2 (tpy)

gen (million MWh)

Figure 2-4. SO2 Emissions and Generation from North Georgia 

Coal-fired EGU Facilities, 2003 - 2009 

2.3.2.2 Smoke Management Plan 

Forestry and agriculture, two of the Georgia’s most significant industries, utilize prescribed burning 

practices to support production. Prescribed burning is the controlled application of fire to existing 

vegetative fuels to accomplish planned land management objectives or to mitigate catastrophic 

wildfires. In addition to managing forests and agricultural resources, prescribed burning helps 

protect lives and property by reducing accumulations of forest fuels and helps to sustain imperiled 

species and ecosystems. The Georgia General Assembly enacted the Georgia Prescribed Burning 

Act to authorize and promote the use of prescribed burning for community protection and for 

silvicultural, environmental, and wildlife purposes. 

Large prescribed burns can produce significant PM2.5 emissions. These emissions, if not properly 

managed, can reach smoke-sensitive areas and have significant negative impacts on the air quality in 

these areas. Smoke-sensitive areas include Georgia’s heavily populated areas and PM2.5

nonattainment areas. Without a prescribed burning program, there is a higher probability of 

catastrophic wildfires, which can threaten personal property and can have even higher negative 

impacts on air quality. 

To prevent negative air quality impacts from prescribed burning, Georgia DNR and the Georgia 

Forestry Commission formulated and adopted Georgia’s Basic Smoke Management Plan (SMP) 

dated April 16, 2008. The plan was developed in accordance with EPA’s “The Interim Air Quality 

Policy on Wildland and Prescribed Fires” and the draft EPA guidance document, “Elements of a 

Smoke Management Program”. The purpose of the SMP is to allow fire to function in its natural role 

in maintaining healthy wildland ecosystems while protecting public health and welfare by mitigating 
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the impacts of air pollutants from wildland and prescribed fires on air quality and visibility. The plan 

is a necessary component in determining Exceptional Events related to prescribed burning and is an 

element of Georgia’s Regional Haze SIP. The Georgia Forestry Commission (GFC), Georgia 

DNR’s EPD, and Georgia DNR’s Wildlife Resources Division (WRD) signed a Memorandum Of 

Understanding (MOU) to implement the SMP on April 16, 2008. The SMP and the MOU are 

included as Appendix B. 

The SMP identifies the following components that should be considered in the planning of 

prescribed burns: 

 smoke mitigation 

 smoke dispersion evaluation 

 public notification 

 air quality monitoring 

Smoke mitigation, smoke dispersion evaluation, and air quality monitoring are important to 

mitigating the effects of prescribed burns on air quality in smoke-sensitive areas. Smoke mitigation 

is accomplished by avoiding smoke-sensitive areas, performing burns under favorable smoke 

dispersion conditions, and managing the generation and release of emissions over time. Smoke 

dispersion evaluations are performed by GFC-certified prescribed fire managers and are supported 

by the GFC’s full-time fire weather meteorologist. Air quality monitoring and forecasting, 

performed by Georgia EPD, provides important air quality data to assist fire managers with their 

decisions on when to schedule prescribed burns. 

In addition to mitigating the impacts of prescribed burns on air quality, the implementation of a SMP 

has benefits with regard to the computation of air quality design values. Design values are statistical 

measures of historical ambient pollutant concentrations that are compared to EPA’s air quality 

standards to determine if attainment of the standard has been achieved. An atypical event, such as an 

unusually large forest fire, can produce PM2.5 emissions that will significantly increase ambient 

concentration measurements, and therefore design value computations, in a nonattainment area. EPA 

will allow the atypical ambient measurements to be excluded from the design value computation if 

the fire event is deemed to be an “exceptional event”. In order for a large fire to qualify as an 

exceptional event, the EPA has stated that a state must demonstrate that a certified SMP was in place 

at the time of the event, or that the state must ensure that the burner employs basic smoke 

management practices. 

All outdoor burning is subject to enforcement through law enforcement officers of GFC, DNR and 

local law enforcement. The enforcement authority is the Georgia Forest Fire Protection Act, as well 

as EPD’s authority to enforce Federal and State air quality regulations and laws. In addition, GFC 

has the authority to void certification of certified prescribed burners if investigation reveals that 

disregard for basic smoke management practices contributed to smoke intrusion into a smokesensitive area. This measure is State enforceable. It is not necessary for the continued maintenance 

of attainment in the Macon area. However, implementation of the SMP will support the maintenance 

of the annual PM 2.5 NAAQS. 
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2.3.3 Federal Control Measures 

Federal control measures related to ambient PM2.5 are focused on the reduction of emissions 

associated with sulfates, nitrates, and direct PM. Federal measures that targeted reduction of these 

emissions between nonattainment designation and the clean data period are as follows: 

 Clean Air Interstate Rule/Cross State Air Pollution Rule 

 Tier 2 Vehicle Standards 

 Heavy-duty Gasoline and Diesel Highway Vehicles Standards, and Ultra-Low Sulfur 

Diesel (ULSD) Rule; 

 Large Nonroad Diesel Engines Rule, and ULSD Rule; 

 Non-Road Spark Ignition Engines and Recreational Engines Standard; and 

 NOx SIP Call in Surrounding States. 

All of the measures were in place prior to 2007, with the exception of the large nonroad diesel rule 

(effective in 2008) and CAIR. Reductions associated with vehicles and engines will increase during 

the maintenance period as older engines are removed from service and replaced by new engines. 

Table 2-6 shows the timetable of implementation of these measures as well as the species controlled 

by each. The continuous drop in PM2.5 concentration from 2005 through 2009 demonstrates that the 

improvement of air quality is due to the implementation of the control measures. Detailed 

discussions of the measures are presented in the following subsections. 

Table 2-6. Timetable of Federal Measure Implementation 

 

Species 

controlled

2001 ‘02 ‘03 ‘04 ‘05 ‘06 ‘07 ‘08 2009

PM2.5 ann. avg. (μg/m3) 16.1 14.8 14.8 16.8 16.7 16.9 16.7 12.3 12.2 

Clean Air Interstate Rule 

(CAIR) 

NOx * 

Tier 2 vehicle standards NOx 

Heavy Duty Engine 

Standard, first phase 

NOx, 

VOC 

 

Heavy Duty Engine 

Standard, second phase, 

and ULSD 

PM, SO2 

Large Nonroad Diesel 

Rule and ULSD 

PM, NOx, 

SO2

 
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Nonroad Spark Ignition 

and Recreational Vehicle 

NOx, 

VOC, CO 

 

NO x SIP Call in 

Surrounding States 

NOx 

* also requires SO2 controls after 2009 

2.3.3.1 Clean Air Interstate Rule 

On May 12, 2005, the US EPA promulgated the “Rule To Reduce Interstate Transport of Fine 

Particulate Matter and Ozone (Clean Air Interstate Rule),” referred to as CAIR. This rule established 

the requirement for States to adopt rules limiting the emissions of NOx and sulfur dioxide (SO2) and 

a model rule for the states to use in developing their rules. The purpose of the CAIR was to reduce 

interstate transport of precursors to fine particulate and ozone. 

The CAIR rule applied to fossil-fuel-fired electric generation units (EGUs), including certain 

cogeneration units, with nameplate capacities of greater than 25 MWe. This rule set annual state 

caps for NOx and SO2 in two phases, with the Phase I caps starting in 2009 and 2010, respectively. 

Phase II caps for NOx and SO2 were to become effective in 2015. 

As part of the CAIR rule, EPA determined that Georgia contributed significantly to downwind PM2.5

nonattainment areas and/or interfered with maintenance of the PM2.5 NAAQS (70 FR 25246-25250). 

Accordingly, a State CAIR rule [Georgia rule 391-3-1-.02(13)] was promulgated that, for the most 

part, mirrors the provisions of the federal rule. 

On July 11, 2008, the U.S. District Court of Appeals in the District of Columbia vacated the Clean 

Air Interstate Rule and remanded it to EPA. A rehearing of the Court’s decision was requested and 

granted. On December 23, 2008, the court remanded CAIR to EPA without vacatur (i.e., the rule 

was still in place). EPA was directed to correct the deficiencies in CAIR that were identified in the 

court’s decision. 

To replace CAIR, EPA promulgated the final Cross-State Air Pollution Rule (76 FR 48208) on 

August 8, 2011. The Cross-state rule imposes restrictions on emissions of NOx and SO2 from states 

identified as having significant impacts on ozone and/or PM2.5 NAAQS attainment or as interfering 

with maintenance of these same standards in downwind states. The requirements of the Cross-state 

Rule were to become effective in 2012 and 2014, which is beyond the 2007-to-2009 clean data 

period for the Macon area. However, on December 30, 2011, the U.S. Court of Appeals for the D.C 

Circuit Court issued a ruling to stay CSAPR pending judicial review. Regardless of the timing of the 

transition from CAIR to CSAPR, or the resulting court-ordered interstate transport remedy, 

emissions of NOx and SO2 have declined significantly and are expected to continue to decrease in the 

future due to the continuation of CAIR and Georgia’s own EGU emission rules. 

2.3.3.2 Tier 2 Vehicle Standards and low-sulfur gasoline 

Federal Tier 2 vehicle standards will reduce NOx emissions from passenger vehicles. The standards 

require all passenger vehicles in a manufacturer’s fleet, including light-duty trucks and sport utility 
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vehicles (SUVs), to meet an average standard of 0.07 grams of NOx per mile. Implementation began 

in 2004 and was completely phased in by 2007. The Tier 2 standards will also cover passenger 

vehicles over 8,500 pounds gross vehicle weight rating (the larger pickup trucks and SUVs), which 

are not covered by the current Tier 1 regulations. 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 implementation of Tier 2. The Tier 2 rule also reduced 

the sulfur content of gasoline to 30 parts per million (ppm) starting in January of 2006. Sulfur occurs 

naturally in gasoline, but interferes with the operation of catalytic converters on vehicles resulting in 

higher emissions. Lower-sulfur gasoline is necessary to achieve the Tier 2 vehicle emission 

standards. 

2.3.3.3 Heavy-Duty Gasoline and Diesel Highway Vehicles Standards & Ultra Low-Sulfur Diesel 

Rule 

New US EPA standards designed to reduce NOx and VOC emissions from heavy-duty gasoline and 

diesel highway vehicles (14001 pounds or more) began to take effect in 2004. A second phase of 

standards and testing procedures, which began in 2007, will reduce particulate matter from heavyduty highway engines and will also reduce highway diesel fuel sulfur content to 15 ppm to prevent 

damage to the emission control devices. The total program is expected to achieve a 90% reduction in 

particulate matter (PM) emissions and a 95% reduction in NOx emissions for these new engines 

using low sulfur diesel, compared to older engines using diesel with higher sulfur content. SO2

emissions will also be reduced due to the lower fuel sulfur content. 

2.3.3.4 Large Nonroad Diesel Engines Rule & Ultra Low-Sulfur Diesel Rule 

In May 2004, the US EPA promulgated new rules for large nonroad diesel engines, such as those 

used in construction, agricultural, and industrial equipment, to be phased in between 2008 and 2014. 

The nonroad diesel rules also reduce the allowable sulfur in nonroad diesel fuel by over 99%. Prior 

to 2006, nonroad diesel fuel averaged about 3,400 ppm sulfur. The rule limits nonroad diesel sulfur 

content to 500 ppm in 2006 and 15 ppm in 2010. The combined engine and fuel rules would reduce 

NOx and PM emissions from large nonroad diesel engines by over 90%, compared to older engines 

using diesel with higher sulfur content. SO2 emissions will also be reduced due to the lower fuel 

sulfur content. 

2.3.3.5 Nonroad Large Spark-Ignition Engines and Recreational Engines Standard 

This standard, effective in July 2003, regulates NOx, hydrocarbons (HC) and carbon monoxide (CO) 

for groups of previously unregulated nonroad engines. The new standard will apply to all new 

engines sold in the United States and imported after these standards began and apply to large sparkignition 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 or 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 formation and ambient CO and 

PM levels. For the off-highway motorcycles and all-terrain-vehicles, model year 2006, the new 
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exhaust emissions standard was phased-in by 50% and for model years 2007 and later at 100%. 

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 

in marinas. Depending on the size of the engine, the standard began phasing in during 2006. 

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

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

emissions are expected by 2020. These controls will help reduce ambient concentrations of ozone, 

CO, and fine PM. 

2.3.3.6 NOx SIP Call in Surrounding States 

In October 1998, the US EPA made a finding of significant contribution of NOx emissions from 

certain states and published a rule that set ozone season NOx budgets for the purpose of reducing 

regional transport of ozone (63 FR 57356). This rule, referred to as the NOx SIP Call, called for 

ozone season controls to be put on utility and industrial boilers, as well as internal combustion 

engines in 22 states in the Eastern United States. A NOx emissions budget was set for each state and 

the states were required to develop rules that would allow the state to meet their budget. A NOx

trading program was established, allowing sources to buy credits to meet their NOx budget as 

opposed to actually installing controls. The emission budgets were to be met by the beginning of 

2004. 

2.3.4 SO2 Emissions Reductions in Upwind States 

As noted previously, secondary sulfate concentrations in a given location can be significantly 

affected by SO2 emissions from distant sources. During the period of 2003 through 2009, SO2

emissions from coal-fired electric generation facilities upwind of Georgia have been significantly 

reduced. 

EPA promulgated the Cross-State Air Pollution Rule (76 FR 48208) on August 8, 2011, and projected 

future emissions to support the rule-making. Modeling in support of the Cross-State Rule has 

established linkages between emissions from upwind states and ambient PM2.5 concentrations in 

downwind receptor states. EPA’s projections indicate that 2012 emissions for the base case (which 

disallows reductions from existing or future CAIR controls) from ten upwind states will contribute 

0.15 μg/m3

 (1 % of the 1997 annual PM 2.5 standard) or more to ambient PM2.5 concentrations in 

Georgia’s 2012 projected nonattainment area (Atlanta). The ten states are Alabama, Illinois, Indiana, 

Kentucky, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, and West Virginia. 

[Source: Appendix D of the Air Quality Modeling Final Rule Technical Support Document, June 

2011, docket item EPA-HQ-OAR-2009-0491-4140]. 

Table 2-7 shows the SO2 emissions trends from coal-fired EGU facilities in the ten upwind states 

during the period 2003 through 2009. The total SO2 emissions from the ten states dropped 

approximately 15 percent from 2003 to 2007 and over 50 percent from 2003 to 2009. The trend of 

aggregated SO2 emissions from these states is presented in Figure 2-5. 
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Table 2-7. Annual SO2 Emissions in States With Downwind Contributions to Georgia 

PM2.5 Exceeding 0.15 μg/m3

State 2003 2005 2007 2009 

AL 458,622 460,072 447,189 277,972 

IL 365,333 326,632 272,571 229,364 

IN 804,829 870,812 714,529 413,726 

KY 529,559 500,224 379,837 252,002 

NC 462,041 500,936 370,826 110,948 

OH 1,175,905 1,085,485 954,646 600,687 

PA 967,185 985,508 951,186 573,618 

SC 203,956 217,386 172,726 97,941 

TN 339,536 266,081 237,231 108,042 

WV 539,858 467,082 371,996 174,583 

 

TOTAL 5,846,824 5,680,218 4,872,738 2,838,883 

Source: EPA Clean Air Markets Division, Acid Rain Program 

EPD understands that the emissions reductions in the upwind states are not permanent and 

enforceable reductions in GA. However, we believe that the reductions provide further evidence that 

the reduced PM2.5 levels in GA during the period 2007 - 2009 are due to SO2 emissions reductions 

achieved both within and outside Georgia. The majority of the upwind reductions are due to state 

rules or consent orders requiring reduced SO2 emissions. With the promulgation of the Cross-State 

Air Pollution Rule, it is highly unlikely that these reductions will be reversed in the future. (It should 

be noted that on December 30, 2011, the U.S. Court of Appeals for the D.C Circuit Court issued a 

ruling to stay CSAPR pending judicial review. Regardless of the timing of the transition from CAIR 

to CSAPR, or the resulting court-ordered interstate transport remedy, emissions of SO2 from upwind 

states have declined significantly and are expected to continue to decrease in the future.)
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0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

2003 2005 2007 2009

SO2 (tons)

Upwind States

Figure 2-5. Trend of Aggregated Annual SO2 Emissions in States With Downwind 

Contributions to Georgia PM2.5 Exceeding 0.15 μg/m3

2.4 Section 110 and Part D Requirements 

Section 110 of the CAA contains the requirements for state implementation plans (SIPs). The 

purpose of a SIP is to provide for the implementation, maintenance, and enforcement of national 

primary ambient air quality standards. Part D, Subpart 1, of CAA Title I (Sections 171 to 179) 

contains general requirements for areas that have been designated nonattainment. As stated in 

Section 1.1 of this maintenance plan, the Macon area was designated as nonattainment for the 1997 

annual fine PM standard in April of 2005. The Macon area was also classified as nonattainment for 

the eight-hour ozone standard, but was redesignated to attainment for this standard in September 

2007 (72FR53432). 

Georgia EPD submitted a PM2.5 nonattainment plan for the Macon area per Title I Part D. With the 

determination that the Macon nonattainment area has attained the 1997 annual fine PM standard 

(Section 2.1.3), the area is no longer subject to the CAA Section 110 and Part D requirements for 

demonstrating attainment, RFP, associated RACM, and contingency for areas designated as 

nonattainment with the NAAQS. Therefore, the nonattainment plan was subsequently withdrawn. 

All other Section 110 and Part D requirements pertaining to the Macon area have previously been 

approved or are currently subject to approval by EPA. 

 
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3.0 Maintenance Plan 

Section 175A of the Clean Air Act Amendments of 1990 defines the general framework of a 

maintenance plan. The core provisions of Section 175A are a quantitative demonstration of 

maintenance of the standard (PM2.5 in this case) and contingency provisions for prompt adoption of 

corrective measures if attainment is not maintained. Per guidance from EPA3

, this maintenance plan 

includes a method to verify continued attainment to support the maintenance demonstration. Per the 

same guidance, this plan also includes a plan to use the ambient monitoring network for verification 

of continued attainment or, if applicable, for triggering contingency provisions. 

3.1 Maintenance Demonstration 

Section 175A of the CAA requires a state that is requesting redesignation to submit a revision to its 

SIP which provides for maintenance of the applicable standard for a minimum of 10 years after the 

redesignation date. Section 107(d)(3)(D) provides EPA up to 18 months from receipt of a complete 

submittal to process a redesignation request. Therefore Georgia EPD is providing a demonstration of 

maintenance through the year 2023. 

There are two generally accepted methodologies for demonstrating maintenance. Under the first 

method, an emissions inventory is compiled for one of the three years which are used to show clean 

(i.e., attaining) ambient data (see Section 2.1). This year is the baseline or attainment year. 

Emissions projections are formulated for the final year of the maintenance period and for 

intermediate years. If each of the projected emission levels is less than the emission level for the 

attainment year, maintenance of the standard is demonstrated. This assumes that ambient 

concentrations will remain below the standard if future annual emissions are kept below the 

inventoried emissions in the chosen attainment year. Under the second maintenance demonstration 

method, air quality modeling is used to project ambient pollutant concentrations and annual design 

values for the final year and intermediate years. If all of the modeled rolling three-year averages of 

the annual design values are below the standard, maintenance is demonstrated. 

Georgia EPD has adopted the method of comparing attainment year emissions to projected emissions 

for this maintenance plan. This approach has been used in the previous maintenance plans submitted 

by EPD and approved by EPA. The following sections discuss the attainment year inventory, the 

projected inventories, and verification of continued attainment. 

3.1.1 Attainment Year Emissions Inventory 

Georgia EPD has selected 2007 as the year for the attainment year emissions inventory. 2007 is one 

of the three years (2007–2009) on which the Macon area’s clean data determination is based. The 

pollutants inventoried and addressed in this maintenance plan are direct PM2.5, SO2, and NOx. The 

following emissions sectors are included in the inventory: 

 Point sources (EGU and non-EGU); 

 Nonpoint sources (including fire); 

 

3

 “Procedures for Processing Requests to Redesignate Areas to Attainment,” September 4, 1992. John 

Calcagni, Director, Air Quality Management Division, OAQPS, USEPA. 
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 Onroad mobile sources; and 

 Nonroad mobile sources (including marine vessels, aircraft, and rail). 

The 2007 inventory, with the exception of on-road mobile emissions, was prepared for Georgia by 

the contractors for the Southeastern Modeling, Analysis, and Planning (SEMAP) project. SEMAP is 

funded by the same ten states that participated in the Visibility Improvement – State and Tribal 

Association of the Southeast (VISTAS) project. Under the SEMAP project, emissions estimates are 

reported by county and source classification code (SCC). The SEMAP emissions inventories were 

developed using data from a number of sources, including state and local agencies and EPA’s 

National Emissions Inventory (NEI). Georgia DOT developed the 2007 inventory of on-road mobile 

emissions. 

The data sources for the attainment-year emissions inventories are summarized in Table 3-1. 

Additional details on the data sources and inventory methods are presented in the following 

subsections and in Appendix C. 

Table 3-1. 2007 Emissions Inventory Sources 

Emissions Source 

Sector 

Inventory Source Version / Year 

Generated 

Basis 

Point – EGU SEMAP 

Georgia Power Co. 

Version 1.8, 2011 EPA’s NEI 

Point – non-EGU SEMAP Version 1.8, 2011 EPA’s NEI 

Nonpoint SEMAP Version 1.1, 2010 EPA’s NEI 

Onroad Mobile GDOT 2011 Georgia DOT (travel demand 

model and Highway 

Performance Monitoring 

System (HPMS)) and 

MOVES2010a 

Nonroad Mobile SEMAP Final Report, 2010 NMIM2008, 2007 NMIM 

County Database, 2008 NEI, 

ERTAC 
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3.1.1.1 Point Sources 

Point sources captured in the inventory include stationary sources whose actual emissions equal or 

exceed 100 tons per year of SO2, NOx, or particulate matter. Emissions from point sources have been 

calculated for EGU and non-EGU sources. 

Plant Scherer, which includes four EGUs, is the lone electric generation facility inside the 

nonattainment area. The plant is located in Monroe County. The non-EGU point sources in the 

Macon area are as follows: 

 Graphic Packaging International 

 Southern Natural Gas Company, Ocmulgee 

 Armstrong World Industries 

 Cherokee Brick and Tile Company 

All four sources are located in Bibb County. 2007 emissions of SO2, NOx, and PM2.5 from EGU and 

non-EGU facilities are presented in Table 3-2. Graphic Packaging International is the largest source 

of emissions from non-EGU point sources. Emissions from the individual non-EGU point sources 

are shown in Table 3-3. 

Table 3-2. Point Source Emissions for 2007 (tons, annual) 

Pollutant EGU (Plant 

Scherer) 

Non-EGU Total Point 

SO2 76,456 447 76,903 

NOx 18,849 1,737 20,586 

PM2.5 1,166 373 1,539 

Table 3-3. Non-EGU Point Source Emissions for 2007 (tons, annual) 

Pollutant Graphic 

Packaging

Southern 

Natural Gas 

Armstrong 

World Ind. 

Cherokee Brick 

and Tile 

SO2 243 0 0 204 

NOx 1259 367 55 56 

PM2.5 272 10 47 44 

The 2007 point source inventory is based on the National Emissions Inventory (NEI) reports for 

reporting years 2005, 2007, and 2008. Emissions from sources that reported for 2007 were generally 

used as reported. For facilities with 2005 and 2008 emissions (but no 2007 emissions), 2007 

emissions were estimated based on a linear interpolation between facility level 2005 and 2008 

emissions on a pollutant-by-pollutant basis to calculate facility level 2007 emissions. For facilities 
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with only 2008 data (no 2007 or 2005 data available), the SIC growth factors from the VISTAS 

Best&Final inventory were used to backcast 2008 reported emissions to 2007. For facilities with 

only 2005 data (no 2007 or 2008 data available), the SIC growth factors from the VISTAS 

Best&Final inventory were used to project 2005 reported emissions to 2007. After the above 

backcasting and projecting was performed, additional adjustments were made for facilities where 

only 2005 data were available and the facility did not operate in 2007 or operated for only part of 

2007. In addition, PM augmentation was performed to generate missing emissions estimates for 

filterable and primary PM2.5, filterable and primary PM10, and condensable PM. See Appendices C 

and C-1 for more details on the development of the 2007 point source emissions inventory. 

3.1.1.2 Nonpoint Sources 

Nonpoint sources captured in the inventory include stationary sources whose emissions levels of 

SO2, NOx, and particulate matter are each less than 100 tons per year. Emissions from nonpoint 

sources in 2007 were obtained from the SEMAP nonpoint source inventory Version 1.1, which was 

developed by Pechan. A default 2007 nonpoint source inventory was created that includes all of the 

source categories covered by the 2008 nonpoint source NEI. 

For all source categories except industrial and commercial/institutional (ICI) fuel combustion, 

emissions data from the 2008 nonpoint source NEI were directly incorporated when the NEI 

emissions were based on 2007 emissions activity data. The NEI emissions estimates were 

recalculated to reflect 2007 activity levels when the NEI emissions reflected 2006 or 2008 activity 

levels. Emissions associated with activity reflected in the point source inventory were removed from 

the nonpoint inventory. 

For ICI fuel combustion, the 2008 nonpoint source NEI developed emissions activity estimates 

rather than emission estimates. Because of the potential importance of these source categories and 

the availability of methodological improvements, Pechan utilized an emissions estimation method 

for ICI fuel combustion that incorporates a few refinements to the NEI method. These emissions 

were supplemented with carry-forward categories from Georgia’s 2005 CERR submission grown 

using EPA’s Economic Growth Analysis System (EGAS). For more information regarding the 

SEMAP nonpoint inventory, please refer to Appendices C and C-2. 

The 2007 nonpoint source emissions for the Macon area are presented in Table 3-4. The largest 

contributors to SO2 emissions were coal-fired and residual-oil-fired industrial boilers. The largest 

contributors to NOx emissions were industrial wood-fired and coal-fired boilers. Emissions from 

fires in 2007 were obtained from the SEMAP final “actual” fire emissions inventory and are shown 

in Table 3-4. This inventory was developed using 2007 burned area data submitted by Georgia, as 

well as updated fuel consumption and emissions factors. 

Table 3-4. Nonpoint Source Emissions for 2007 (tons, annual) 

Pollutant Nonpoint 

(excluding fire) 

Fire Total 

Nonpoint 

SO2 752 1 753 

NOx 955 3 958 

PM2.5 1505 11 1516 
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The 2007 level of PM2.5 emissions from nonpoint sources, excluding fire, was 1505 tons. This 

quantity accounted for 44 percent of total PM2.5 emissions in the Macon area. The top three nonpoint 

source classifications for PM2.5 emissions were industrial wood-fired boilers, dust from unpaved 

roads, and construction activities. 

Table 3-5. Largest Nonpoint PM2.5 Emissions by Source Classification 

SCC Description 2007 

PM2.5

(tons) 

2102008000 Stationary Fuel Comb /Industrial /Wood /Total: All Boiler Types 807 

2296000000 Unpaved Roads /All Unpaved Roads /Total: Fugitives 361 

2311020000 Construction SIC 15 – 17/Industrial, Commercial, and 

Institutional/All (e.g., land clearing, demolition, excavation) 

52 

3.1.1.3 Onroad Mobile Sources 

USEPA’s MOVES2010a mobile source emissions model was run in inventory mode to generate 2007 

on-road mobile source emissions of SO2, NOx, and PM2.5. The 2007 onroad mobile source emissions 

for The Macon Area are presented in Table 3-6. 

Table 3-6. Onroad Mobile Source Emissions for 2007 (tons, annual) 

Pollutant Onroad 

Emissions 

SO2 54

NOx 7539

PM2.5 266

The following non-default inputs to the MOVES model were used: 

• registration distribution by age 

• vehicle population 

• vehicle miles traveled (VMT) 

• hourly temperature and relative humidity 
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The age distribution and vehicle population inputs were based on 2002 vehicle counts by MOBILE6 

vehicle type obtained from R.L. Polk & Company. The vehicle population was grown to 2007 using 

a combination of Georgia Department of Revenue registration data (for buses and motorcycles) and 

the change in person population estimates from the U.S. Census (for the other MOBILE6 vehicle 

types). VMT fractions were based on MOVES defaults by source type and adjusted using GDOT 

count data. 

Actual 2007 temperature and humidity data extracted from the "NCD20090531" version of the 

county database in EPA's National Mobile Inventory Model were used as meteorological inputs to 

MOVES2010a for 2007. For a detailed discussion on how the on-road mobile emission inventory 

was developed, see Appendices C, C-3, and C-4. 

3.1.1.4 Nonroad Mobile Sources 

The nonroad sector is comprised of nonroad engines included in EPA’s NONROAD model, such as 

recreational marine and land-based vehicles, farm, construction and industrial machinery, and lawn 

and garden equipment. This sector also includes engines not modeled in NONROAD, specifically 

aircraft, commercial marine vessels, and locomotives. There are no commercial marine vessel 

emissions sources in the Macon area. 2007 nonroad mobile emissions are presented in Table 3-7. 

Emissions from NONROAD model source categories in 2007 were obtained from the SEMAP final 

nonroad mobile sources emissions inventory. These emissions were calculated using EPA’s latest 

National Mobile Inventory Model, NMIM2008, which incorporates EPA’s latest NONROAD model 

(NONROAD2008) and reflects all of EPA’s final nonroad standards to date. The county/monthly 

gasoline profile assignments in the CountyYearMonth table and the gasoline fuel profiles in the 

Gasoline table of the 2007 NMIM county-level database (NCD) were updated with data provided by 

the state of Georgia. For more information regarding the SEMAP nonroad inventory, please refer to 

Appendices C and C-2. 

2007 emissions from aircraft and locomotives were obtained from the SEMAP final nonroad mobile 

source emissions inventory. For more information regarding the SEMAP marine, aircraft, and 

locomotives inventory, please refer to Appendices C and C-5. 

Table 3-7. Nonroad Mobile Source Emissions for 2007 (tons, annual) 

Pollutant 

(tons) 

Nonroad - 

except air and 

rail

Aircraft Locomotive Total 

Nonroad

SO2 40 1 7 48 

NOx 684 4 740 1428 

PM2.5 71 3 24 98 

3.1.1.5 Summary of 2007 Emissions Inventory 

The total 2007 The Macon Area emissions of SO2, NOx, and PM2.5 are presented for each source 

sector in Table 3-8. The majority of SO2 emissions, by far, are from point sources. The majority of 
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NOx emissions is from point and onroad mobile sources. The majority of PM2.5 emissions are from 

nonpoint and point sources. 

Table 3-8. Attainment-year (2007) Emissions Inventory (tons, annual)

Pollutant 

(tons) 

Point 

Total 

Point 

EGU 

Point 

NonEGU 

Nonpoint Onroad 

Mobile 

Nonroad 

Mobile 

Total 

SO2 76,903 76,456 447 753 53 48 77,757

NOx 20,586 18,849 1,737 958 7,539 1,428 30,511

PM2.5 1,539 1,166 373 1,516 266 98 3,419

3.1.2 Projected Emissions Inventories 

As discussed previously, Georgia EPD is providing a demonstration of maintenance through the year 

2023 (the maintenance year). Emissions projections to support maintenance through 2023 have been 

prepared for the years 2017 and 2023. In addition, emissions have been calculated by interpolation 

for the years 2014 and 2020. Emissions for these additional years provide additional reference 

points for periodic assessment of maintenance of the standard. Maintenance period emissions 

controls, projection methods, and projected inventories are discussed in the remainder of this 

subsection. 

3.1.2.1 Methods and Projected Inventories 

Projected emissions inventories are calculated by applying applicable control and growth factors to 

the 2007 emissions of individual sources or source categories. The control and growth factors may 

apply for some or all of the years 2008 (year following attainment inventory) through 2023 (out 

year). The bases used to determine these factors are summarized in Table 3-9. 
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Table 3-9. Bases of Control and Growth Factors for 2017 and 2023 Inventories 

Source 

Category 

Control Basis Growth Factor Basis 

Point – EGU Implementation of GA rule (sss) 

for SO2 and NOx controls; VISTAS 

2012 projection inventory 

Coal consumption forecasts in 2010 

Annual Energy Outlook (AEO) 

Point – non-EGU Regulatory review - no additional 

controls defined at this time 

EGAS growth factors by SCC and county 

for 2017 and 2023. 

Nonpoint Regulatory review - no additional 

controls defined at this time 

EGAS growth factors by SCC for 2017 

and 2023. 

Nonpoint – fire No additional controls anticipated No growth anticipated 

Onroad Mobile MOVES inventory mode (PM2.5, 

NOx, SO2) for 2023. All known 

Federal controls. 

MOVES inventory mode (PM2.5, NOx, 

SO2) for 2023. Vehicle population growth 

from human population projections. 

Vehicle miles traveled (VMT) growth 

from Georgia DOT. 

Nonroad Mobile NMIM 2008 NMIM 2008 

Nonroad Mobile 

– marine, 

aircraft, and rail 

SEMAP (Pechan) control factors 

by SCC for 2017 and 2023 

SEMAP (Pechan) growth factors by SCC 

for 2017 and 2023 

The pollutants whose emissions are projected are SO2, NOx, and direct PM2.5. As with the attainment 

inventory, emissions from the following sectors are projected: 

 Point sources (EGU and non-EGU) 

 Nonpoint sources (including fire) 

 Onroad mobile sources 

 Nonroad mobile sources (including marine vessels, aircraft, and rail) 

The projected inventories are presented in the following subsections. The methods used to develop 

the emissions projections are presented in more detail in Appendix C. 

3.1.2.2 Point Sources 

EGU point source emissions in 2017 and 2023 were estimated using growth factors and control 

factors. Growth factors were calculated based on coal consumption for the southeastern region in the 
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Energy Information Administration’s AEO2010 report. The SO2 control factor due to Flue Gas 

Desulfurization (FGD) was assumed to be 95% according to the VISTAS 2012 Projection Emissions 

Inventory (see Appendices C and C-6). Georgia’s rule (sss) requires SO2 controls on all four of Plant 

Scherer’s EGUs, with the controls being phased in from July 1, 2011, through December 31, 2014. 

In addition, Georgia Rule (uuu) requires 95% reduction of SO2 for all four of Plant Scherer’s EGUs 

by January 1, 2015. The NOx control factor due to Selective Catalytic Reduction (SCR) was 

assumed to be 82.5% according to the VISTAS 2012 Projection Emissions Inventory. Georgia’s rule 

(sss) requires NOx controls on all four EGUs on the same schedule as the SO2 controls. Operation of 

the NOx controls is required only during the months of May through September. The PM2.5 control 

factor associated (as a cobenefit) with the new SO2 controls was assumed to be 50% based on Table 

5.4-1 on page 5.4-24 of EPA’s document "Stationary Source Control Techniques Document for Fine 

Particulate Matter" (EC/R Incorporated, 1998). 

As noted in subsection 2.3.3, EPA promulgated CSAPR in 2011 but the rule was stayed later in the 

year. When the rule was promulgated, Georgia was identified as a covered state and therefore would 

have been required to comply with state-wide allocations of SO2 and/or NOx emissions from covered 

EGUs starting in 2012. The future of the rule is not known at this time and therefore the rule’s 

requirements have not been incorporated into the emissions projections presented here. Any further 

reductions that may ultimately be required by the Cross-State Rule will only strengthen the case for 

maintenance of the NAAQS as documented in this plan. 

Projected EGU point source emissions are presented in Table 3-10. The projections show a dramatic 

reduction in SO2 emissions as well as significant reductions in NOx and PM2.5 emissions. Emissions 

levels for 2014 were calculated by linear interpolation between 2007 and 2017. Emissions levels for 

2020 were calculated by linear interpolation between 2017 and 2023. 

Table 3-10. Projected Point Source Emissions (tons) 

Pollutant 2007 

(attainment)

2014 2017 2020 2023 

EGU 

SO2 76,456 25,649 3,874 3,943 4,012 

NOx 18,849 14,368 12,448 12,670 12,892 

PM2.5 1,166 763 591 601 612 

Non-EGU 

SO2 447 488 505 528 551 

NOx 1,737 1,861 1,914 2,001 2,089 

PM2.5 373 424 446 472 498 

Total Point 

SO2 76,903 26,137 4,739 4,471 4,563 

NOx 20,586 16,229 14,362 14,671 14,981 

PM2.5 1,539 1,187 1,037 1,073 1,110 

Projected non-EGU point source emissions are shown in Table 3-10 (area totals) and in Table 3-11 

(by facility, 2023 only). The emissions for 2017 and 2023 were estimated using SCC-specific and 

county-specific growth factors generated with EPA’s Economic Growth Analysis System version 5.0 

(EGAS 5.0). Appendix C-7 contains the SCC-specific growth factors for the Macon area. The 
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projections show moderate increases in emissions of all three pollutants. No additional future 

controls can be defined for non-EGU point sources at this time. Emissions levels for 2014 and 2020 

were calculated by interpolation as described above. 

Table 3-11. Non-EGU Point Source Emissions for 2023 (tons, annual) 

Pollutant Graphic 

Packaging

Southern 

Natural Gas 

Armstrong 

World Ind. 

Cherokee 

Brick and Tile 

SO2 263 0 0 288

NOx 1,493 445 71 79

PM2.5 343 12 80 63

Projected total point source emissions (sum of EGU and non-EGU) are shown in Table 3-10. The 

projections show dramatic decreases in emissions of SO2 as well as moderate decreases in emissions 

of NOx and PM2.5. 

3.1.2.3 Nonpoint Sources 

Nonpoint source emissions, excluding fire, in future years 2017 and 2023 were estimated using SCCand county-specific growth factors generated with EGAS 5.0. Appendix C-7 contains the SCCspecific growth factors for The Macon Area. No additional future controls can be defined for these 

sources at this time. 

Projections of nonpoint source emissions are presented in Table 3-12. Emissions from fire in future 

years 2017 and 2023 were assumed to be the same as 2007 emissions. The projections show a small 

increase in emissions of SO2 as well as moderate increases in emissions of NOx and PM2.5. The 

largest contributors to projected SO2 emissions are coal-fired and residual-oil-fired industrial boilers. 

The largest contributors to projected NOx emissions are industrial wood-fired boilers and industrial 

natural-gas-fired boilers and internal combustion engines. 
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Table 3-12. Projected Nonpoint Source Emissions (tons) 

Pollutant 2007 

(attainment)

2014 2017 2020 2023 

 

Nonpoint 

(excluding fire) 

 

SO2 752 778 789 801 814

NOx 955 1057 1100 1144 1189

PM2.5 1505 1704 1790 1867 1943

 

Fire 

SO2 1 1 1 1 1

NOx 3 3 3 3 3

PM2.5 11 11 11 11 11

 

Total Nonpoint 

SO2 753 779 790 802 815

NOx 958 1060 1103 1147 1192

PM2.5 1516 1715 1801 1878 1954

The top three nonpoint source classifications for 2023 PM2.5 emissions are industrial wood-fired 

boilers, dust from unpaved roads, and construction activities (see Table 3-13). Projected PM2.5

emissions from these three source classifications make up over 80 percent of total projected PM2.5

emissions. 

Table 3-13. Largest Nonpoint PM2.5 Emissions by Source Classification, Year 2023 

SCC Description 2023 PM2.5

(tons) 

2102008000 Stationary Fuel Comb /Industrial /Wood /Total: 

All Boiler Types 

1056

2296000000 Unpaved Roads /All Unpaved Roads /Total: 

Fugitives 

468

2311020000 Construction SIC 15 – 17/Industrial, 

Commercial, and Institutional/All (e.g., land 

clearing, demolition, excavation) 

71
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3.1.2.4 Onroad Mobile Sources 

EPD ran USEPA’s MOVES2010a mobile source emissions model in inventory mode to generate 

2023 onroad mobile source emissions of SO2, NOx, and PM2.5. Intermediate year emissions were 

generated by interpolating between 2007 and 2023. The following non-default inputs to the model 

were used: 

 Vehicle age distribution 

 average speed distribution 

 vehicle population 

 vehicle miles traveled (VMT) 

 road type distribution 

 ramp fraction 

 hourly temperature and relative humidity 

The vehicle age distribution was based on R.L. Polk & Co. registration data. MOVES2010a defaults 

were used for Heavy-Duty Diesel Vehicle Class 8B. Person population growth projections for the 

Macon Area Metropolitan Planning Organization (MPO) area were used to calculate the 2023 

vehicle population. The 2023 annual VMT were calculated by Georgia DOT using travel demand 

model outputs and HPMS counts, as well as speed distribution, road type distribution, and ramp 

fraction. Temperature and humidity inputs were assumed to be the same as year 2007. 

The projected onroad mobile source emissions levels are presented in Table 3-14. Onroad emissions 

of all three pollutants trend downward significantly during the maintenance period. The trend in SO2

is of less importance since onroad mobile sources emit very little SO2. For a detailed discussion on 

how the onroad mobile emission inventory was developed, see Appendices C, C-3, and C-4. 

Table 3-14. Projected Onroad Mobile Source Emissions (tons) 

Pollutant 

(tons) 

2007 

(attainment)

2014 2017 2020 2023 

 

SO2 53 44 31 25 18 

NOx 7,539 6,022 4,072 3,031 1,991 

PM2.5 266 213 144 107 70 
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3.1.2.5 Nonroad Mobile Sources 

Projections of nonroad emissions in 2017 and 2023, excluding air and rail sources, were calculated 

using NMIM2008 with the same meteorological inputs as for 2007. Defaults in NMIM 2008 were 

used for other inputs. 

Growth factors for all aircraft engine and airport-related SCCs were based on landing and take-off 

operation (LTO) projections available from the Federal Aviation Administration’s Terminal Area 

Forecasts (FAA, 2010). Growth rates for military aircraft were held constant at 2007 levels. No 

control factors were applied to aircraft emissions. 

Growth factors for freight rail sector emissions were based on fuel consumption forecasts. For 

passenger and commuter rail, growth factors were developed from national forecasts of intercity rail 

diesel consumption and commuter rail diesel consumption. Control factors were based on US EPA’s 

locomotive engine regulatory impact analysis and associated emission factor guidance. 

The nonroad mobile source emissions projections are presented in Table 3-15. Total emissions of all 

three pollutants trend downward significantly during the maintenance period. As with onroad 

sources, the downward trend in SO2 is of less importance since nonroad sources emit very little SO2. 

For a detailed discussion on how the nonroad mobile emissions projections were developed, see 

Appendix C. 

 

Table 3-15. Projected Nonroad Mobile Source Emissions (tons) 

Pollutant 

(tons) 

2007 

(attainment) 

2014 2017 2020 2023 

Nonroad* 

SO2 40 13 1 1 1 

NOx 684 453 354 307 261 

PM2.5 71 53 46 40 34 

 

Aircraft 

SO2 1 0 0 0 0 

NOx 4 3 2 2 2 

PM2.5 3 3 3 3 3 

 

Locomotive 

SO2 7 2 0 0 0 

NOx 740 615 561 519 476 

PM2.5 24 17 14 12 11 

 

Tot. Nonroad 

SO2 48 15 1 1 1 

NOx 1,428 1,071 917 828 739 

PM2.5 98 73 63 55 48 

* excluding aircraft and locomotive emissions 
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3.1.3 Emissions Projections Summary and Demonstration of Maintenance of Attainment 

The consolidated emissions projections for all Macon area sources are presented in Table 3-16. 

Emissions of SO2 and NOx drop significantly from 2007 to 2023. This is a reflection of the 

implementation of the majority of state and federal controls during the first half of the maintenance 

period. Overall, emissions of SO2 and NOx are projected to decline by 93 percent and 38 percent, 

respectively, over the course of the maintenance period. Emissions of PM2.5 are projected to decline 

by 7 percent. Due to the significant projected decreases in emissions of SO2 and NOx and to the 

small decrease in projected PM2.5 emissions, GA EPD believes that maintenance of the annual PM2.5

standard is demonstrated. 

 

Table 3-16. Projected Emissions – Total of All Sectors (tons) 

Pollutant 

(tons) 

2007 

(attainment)

2014 2017 2020 2023 % change, 

2007- 2023 

 

SO2 77,757 26,975 5,201 5,299 5,397 - 93

NOx 30,511 24,382 20,454 19,677 18,903 -38

PM2.5 3,419 3,188 3,045 3,113 3,182 -7

3.1.4 Emissions Decreases 

An emissions surplus represents the degree of improvement (reduction) in 2023 emissions compared 

to the attainment year (2007) emissions. The surpluses are shown in Table 3-17 for each pollutant. 

A positive surplus reflects an emissions decrease from the attainment year to 2023. Portions of the 

NOx and PM2.5 surpluses will be allotted to the Motor Vehicle Emissions Budget as a safety margin 

(see Section 4). 

 

Table 3-17. Emissions Decrease 

Pollutant Surplus Emissions* 

2007 to 2023 (tons) 

 

SO2 72,363

NOx ** 11,608

PM2.5 ** 237

* Surplus = (2007 emissions level) – (2023 emissions level) 

** These quantities do not reflect allotment to Motor Vehicle Emissions Budget 
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3.1.5 Verification of Continued Attainment 

Items 5.c and 5.d of the September 4, 1992, EPA guidance memo outline requirements for 

verification of continued attainment. Verification of continued attainment is accomplished through 

operation of the ambient PM2.5 monitoring network and through periodic updates of the area's 

emissions inventory. 

The location and operation of EPD’s FRM monitors in the Macon Area are described in Section 2.1 

of this plan. During the maintenance period EPD will continue to operate a federal reference 

monitor in the Macon Area per the requirements of 40 CFR Part 58. 

The Consolidated Emissions Reporting Rule (CERR) was promulgated by EPA on June 10, 2002. 

The CERR was replaced by the Annual Emissions Reporting Requirements (AERR) rule on 

December 17, 2008. The most recent triennial inventory for Georgia was compiled for 2008. The 

larger point sources of air pollution will continue to submit data on their emissions on an annual 

basis as required by the AERR. Emissions from the rest of the point sources, the nonpoint source 

portion, and the onroad and nonroad mobile sources continue to be quantified on a three-year cycle. 

The inventory will be updated and maintained on a three-year cycle. As required by the AERR, the 

next overall emissions inventory will be compiled for 2011. 

3.2 Contingency Provisions 

Section 175A(d) of the Clean Air Act requires that the maintenance plan include provisions for 

contingency measures that would promptly be implemented to correct a violation of the standard, 

should this occur, after redesignation of an area as an attainment area. The measures may include 

rules or other measures that are not yet effective, but EPD agrees to adopt and implement, as 

expeditiously as practicable, when required by this plan. The minimum requirement for contingency 

provisions is the implementation of all measures that were contained in the SIP for the area (i.e., the 

nonattainment plan) before the redesignation. In addition, EPA guidance (John Calcagni memo 

dated September 4, 1992) specifies the following pertaining to contingency provisions in the 

maintenance plan: 

 identification of additional measures that would be considered for implementation 

should a violation occur 

 identification of triggers for the implementation of additional contingency measures 

 a schedule and procedure for adoption and implementation of additional measures (with 

time limit) 

3.2.1 Contingency Measure Triggers 

Section 175A(d) of the Clean Air Act Amendments requires that the maintenance plan include 

provisions for contingency measures that would promptly be implemented by the state to correct any 

violation of the annual PM2.5 NAAQS after redesignation of an area as an attainment area. A list of 

potential contingency measures that could be considered for future implementation in such an event 

should also be included in the maintenance plan. 

EPD has developed a contingency plan for the Macon PM2.5 maintenance area. Contingency 

measures are intended to provide further emission reductions in the event that violations of the 

NAAQS occur after redesignation to attainment. Consistent with this plan, EPD agrees to adopt and 

implement, as expeditiously as practicable, the necessary corrective actions in the event that 

violations of the standard occur within the maintenance area after redesignation to attainment. 
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Contingency measures as described below would be adopted and implemented within 24 months of a 

contingency trigger unless EPD has demonstrated that technical or economic feasibility warranted a 

period longer than 24 months. 

EPD will use actual ambient monitoring and emissions inventory data as the indicators to determine 

whether contingency measures would be implemented. In accordance with 40 CFR Part 58, ambient 

monitoring data that indicates a violation of the annual PM2.5 NAAQS will begin the process to 

implement these contingency measures according to the protocols identified below. The contingency 

plan provides for corrective responses should the NAAQS be violated, or if emissions in the Macon 

maintenance area increase significantly above current levels. 

Tier I. A Tier 1 trigger is activated when any one of the following conditions occurs: 

 the previous calendar year’s annual average PM2.5 concentration exceeds the standard by 

1.5 ug/m3

 or more 

 the annual average PM2.5 concentration in each of the previous two consecutive calendar 

years exceeds the standard by 0.5 ug/m3

 or more 

 the total maintenance area SO2 emissions in the most recent NEI exceeds the 

corresponding attainment-year inventory by more than 10.0 percent 

 the total maintenance area PM2.5 emissions in the most recent NEI exceeds the 

corresponding attainment-year inventory by more than 30.0 percent 

 

EPD will conduct an evaluation as expeditiously as practicable to determine if the trend is likely to 

continue. If it is determined that additional emission reductions are necessary, EPD will adopt and 

implement any required measures in accordance with section 3.2.2. 

The PM2.5 trigger concentrations described above apply to the PM2.5 federal reference monitors in the 

maintenance area. EPD will evaluate a Tier I condition, if it occurs, as expeditiously as practicable 

to determine the cause(s) of the ambient PM2.5 or emissions inventory increase and to determine if a 

Tier II condition (see below) is likely to occur. 

Tier II. A Tier II trigger is activated when any violation of the annual PM2.5 NAAQS at any FRM in 

the Macon maintenance area is recorded, based on quality-assured monitoring data. In this event, 

EPD will conduct a comprehensive study to determine the cause(s) of the ambient PM2.5 increase and 

to determine if the increase is likely to continue and will implement any required measures as 

expeditiously as practicable, taking into consideration the ease of implementation and the technical 

and economic feasibility of selected measures. 

3.2.2 Schedule and Procedure for Adoption and Implementation of Contingency Measures 

EPD will, in the event of 1) a Tier II trigger condition or 2) a Tier I condition in which EPD has 

determined that a Tier II condition is likely to occur, conduct a comprehensive study to determine 

whether or not contingency measures are required for the maintenance of the PM2.5 standard. Since 

the Macon area may be influenced by emissions from outside the maintenance area, the study will 

attempt to determine whether the trigger condition is due to local emissions, emissions from 

elsewhere, or a combination of the previous. The comprehensive analysis, based on quality-assured 

ambient data, will examine: 
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 the severity of the trigger condition; 

 the meteorological conditions (in the case of an ambient concentration trigger) 

associated with the trigger condition; 

 potential contributing local emissions sources; 

 potential contributing emissions resulting from regional or long-range transport; 

 the geographic applicability of possible contingency measures; 

 emission trends, including implementation timelines of potential control measures; 

 timelines of “on-the-books” (adopted) measures that are not yet fully implemented 

(e.g., Georgia Rule (sss) and Rule (uuu) SO2 controls); and 

 current and recently identified control technologies. 

The comprehensive study will be completed and submitted to EPA as expeditiously as practical but 

no later than nine months after the Tier I or Tier II trigger is activated. If EPD determines, through 

the comprehensive study, that contingency measures are required for maintenance of the standard, 

the appropriate corrective measures will be adopted and implemented within 18 to 24 months after 

the Tier I or II trigger occurs. These control measures, which will continue to produce substantial 

reductions in fine particulate matter and its precursors in excess of what is relied upon in this 

maintenance plan, include the Georgia Multipollutant Rule, which is described in section 2.3.2.1 of 

this maintenance plan, as well as diesel engine retrofit, replacement, and repowering programs and 

truck stop electrification programs which are currently being implemented by Georgia EPD. 

If the study determines that additional measures are required, rules will be adopted no later than 18 

months following the date on which the Tier I or Tier II trigger is activated. Selection of measures 

will take into consideration the ease of implementation as well as technical and economic feasibility. 

If it is determined that adoption and implementation of a rule will take longer than 24 months 

following the trigger date, EPD will submit for EPA’s approval a revised schedule for the 

development and adoption of contingency measures. 

3.2.3 Contingency Measures 

If the analysis required above determines that emissions from the local area are contributing to the 

trigger condition, EPD will evaluate those measures as specified in Section 172 of the CAA for 

control options as well as other available measures. If a new measure/control is already promulgated 

and scheduled to be implemented at the federal or state level, and that measure/control is determined 

to be adequate, additional local controls may be unnecessary. Under Section 175A(d), the minimum 

requirement for contingency measures is the implementation of all measures that were contained in 

the SIP before the redesignation. Currently all such measures are in effect for the Macon NAA; 

however, an evaluation of those measures, such as RACT, can be performed to determine those 

measures are adequate or up-to-date. In addition to those identified in section 3.2.2, contingency 

measure(s) will be selected from the following types of measures or from any other measure deemed 

appropriate and effective at the time the selection is made: 

 Reasonably Available Control Measures (RACM) for sources of SO2 and PM2.5; 

 Reasonably Available Control Technology (RACT) for point sources of SO2 and PM2.5; 

 Expansion of RACM/RACT to area(s) of transport within the State; 
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 Mobile source measures; and 

 Additional SO2 and/or PM2.5 reduction measures yet to be identified. 

Any resulting contingency measure(s) will be based upon cost effectiveness, emission reduction 

potential, economic and social considerations, ease and timing of implementation, and other 

appropriate factors. The maintenance area is located adjacent to the Atlanta metropolitan area, which 

is currently subject to PM2.5 nonattainment SIP provisions. 

Adoption of additional control measures is subject to necessary administrative and legal processes. 

EPD will solicit input from interested and affected persons (stakeholders) in the area prior to 

selecting appropriate contingency measures. No contingency measure will be implemented without 

providing the opportunity for full public participation. This process will include issuance of notices, 

an opportunity for public hearing, and other measures required by Georgia law. 
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4.0 Motor Vehicle Emissions Budget 

The transportation conformity rule (40CFR93.100 - 40CFR93.129) ensures that projects and plans 

funded by the Federal Highway Administration and the Federal Transit Administration conform to air 

quality SIPs and maintenance plans. In the case of a NAAQS maintenance plan, the rule requires a 

motor vehicle emissions budget (MVEB) to be established for the last year of the plan’s maintenance 

period. The rule, at 40CFR93.124(a), describes a motor vehicle emissions budget as "...the 

implementation plan's estimate of future [motor vehicle] emissions." Such budgets establish caps on 

motor vehicle emissions; projected emissions from transportation plans and programs must be equal 

to or less than these caps for a positive conformity determination to be made. Transportation 

conformity determinations are required for non-exempt federally funded highway and transit projects 

before they are funded and approved and for transportation plans and transportation improvement 

programs. 

4.1 Pollutants 

For the Macon Area, MVEBs will be set for direct PM2.5 and NOx only. 40 CFR Parts 93.119(f)(7) 

through (10) identify the PM2.5 pollutants which must be analyzed for transportation conformity 

purposes. These parts of the rule are listed below: 

§119(f)(7) - PM2.5 in PM2.5 areas; 

§119(f)(8) - Reentrained road dust in PM2.5 areas only if the EPA [Environmental Protection Agency] 

Regional Administrator or the director of the State air agency has made a finding that emissions 

from reentrained road dust within the area are a significant contributor to the PM2.5 nonattainment 

problem and has so notified the MPO and DOT [Department of Transportation]; 

§119(f)(9) - NOx [nitrogen oxides] in PM2.5 areas, unless the EPA Regional Administrator and the 

director of the State air agency have made a finding that emissions of NOx from within the area are 

not a significant contributor to the PM2.5 nonattainment problem and has so notified the MPO and 

DOT; and 

§119(f)(10) - VOC, SO2 and/or ammonia in PM2.5 areas if the EPA Regional Administrator or the 

director of the State air agency has made a finding that any of such precursor emissions from within 

the area are a significant contributor to the PM2.5 nonattainment problem and has so notified the 

MPO and DOT. 

Primary, or direct, PM2.5 emissions must be considered for all transportation conformity regional 

emissions analyses. For the Macon Area, NOx must also be considered since EPA has not approved 

Georgia EPD’s finding that NOx is not a significant contributor to the PM2.5 nonattainment problem 

in the Macon area. None of the other pollutants identified above have been determined to be 

significant contributors to PM nonattainment in the Macon area. SO2 from coal combustion is 

significant but levels of SO2 emissions from mobile sources are very low and therefore not 

significant for transportation conformity purposes. 
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4.2 Methodology 

In preparation of this Macon PM2.5 Maintenance Plan, EPD worked closely with the Georgia 

Department of Transportation (GDOT) and the Macon Area Transportation Study (MATS) to 

develop the estimates of mobile source emissions for the Macon nonattainment area. MATS is the 

metropolitan planning organization (MPO) for the Macon area. Mobile source inventories for 2023 

were developed using the latest available planning assumptions, the most recent travel demand 

model, EPA's latest motor vehicle emission factor model, and vehicle population and age 

distributions developed from registration data obtained from R.L. Polk & Company. The 

methodology used to calculate the highway mobile source emissions on which the 2023 MVEBs are 

based is discussed below. 

Emissions from motor vehicles were estimated as a sum of products of vehicle activity measures and 

vehicle emissions factors. Vehicle activity measures (e.g. vehicle miles traveled, or VMT) are 

determined from a county-specific travel demand model. Vehicle emissions factors are determined 

from a motor vehicle emissions model. See Appendices C, C-3, and C-4 for more details on the 

development of the travel demand model and the determination of emissions factors. 

The MOVES2010a motor vehicle emission model was used to calculate 2023 emission factors with 

all currently known 2023 mobile source control rules in place. The MOVES model was run in 

Inventory Mode. The emission factors reflect all federal controls, e.g., the Federal Motor Vehicle 

Control Program including Tier 1 and (beginning with 2006 models) Tier 2 tailpipe standards; and 

the National Low Emission Vehicle program. MOVES2010a produces three sets of emission factors 

per run: 

 rate per distance; 

 rate per vehicle; and 

 rate per profile 

Of these three types of emission factors, the first is multiplied by VMT and the second two by 

vehicle population. Note that rate per profile emissions (i.e., vapor venting) are not applicable to 

PM2.5 modeling. 

The MATS travel demand model is developed and maintained by GDOT. Inputs to the model are 

socioeconomic data and the highway network that consists of roadway segments (links) and 

intersections (nodes). Outputs include vehicle activity, number of trips, vehicle population, and other 

data. The use of a county-specific travel demand model for transportation conformity calculations is 

consistent with the transportation conformity rule at 40CFR93.122(b) and (d), which requires a 

network-based travel model emissions estimation methodology if the use of such procedures has 

been the previous practice of the MPO. The use of such a methodology has been the previous 

practice of MATS. 

Section 93.105(b) of the Transportation Conformity Rule and Sections 106(g) and 106(h) of 

Georgia's transportation conformity SIP require interagency consultation for SIP development. 

Accordingly, a detailed listing of the procedures and planning assumptions used for the regional 

emissions analysis supporting development of the MVEB was presented to the Macon interagency 

consultation committee for review in October, 2011. The assumptions used to develop Macon's 

conforming Long Range Transportation Plan and Transportation Improvement Program were also 

used to develop the network and emissions for this maintenance plan MVEB. 
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4.3 Motor Vehicle Emissions Budgets and Safety Margins 

The projected 2023 on-road motor vehicle emissions for direct PM2.5 and NOx are 70.2 and 1,991 

tons, respectively. A budget for SO2 is not required. On-road emissions of SO2 are considered to be 

“de-minimus” (70FR 24283), and therefore no budget is necessary. The on-road mobile emissions, 

emissions budgets, and safety margins are presented in Table 4-1. A safety margin is necessary to 

accommodate the variabilities, or worst-case scenarios that can occur due to future planning 

assumptions. 

The worst-case daily motor vehicle emissions projection for PM2.5 is 14.7 percent above the 

projected 2023 on-road emissions. In a worst-case scenario, the needed annual safety margin for the 

MVEB would be 10.3 tons resulting in an overall MVEB of 80.5 tons per year. 

The worst-case daily motor vehicle emissions projection for NOx is 9.8 percent above the projected 

2023 on-road emissions. In a worst-case scenario, the needed annual safety margin for the MVEB 

would be 196 tons resulting in an overall MVEB of 2,187 tons per year. 

Table 4-1. 2023 Motor Vehicle Emissions, Emissions Budgets, and Safety Margins 

Pollutant Projected 2023 

On-Road 

Emissions 

(tons) 

Safety Margin 

Allotted to MVEB 

(%) 

Safety Margin 

Allotted to 

MVEB (tons) 

MVEB with Safety 

Margin (tons) 

PM2.5 70.2 14.7 10.3 80.5

NOx 1,991 9.8 196 2,187
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5.0 Conclusion 

Section 107(d) of the CAA states that an area can be redesignated to attainment if the following 

conditions are met: 

1. The EPA has determined that the NAAQS has been attained. 

2. The applicable implementation plan has been fully approved by EPA under Section 110(k). 

3. The EPA has determined that the improvement in air quality is due to permanent and 

enforceable reductions in emissions. 

4. The state has met all applicable requirements for the area under Section 110 and Part D. 

5. The EPA has fully approved a maintenance plan, including a contingency plan, for the area 

as required by CAA Section 175A. 

Table 5-1. Summary of Projected SO2 Emissions – Total of All Sectors (tons) 

Source 

2007 

attainment 

(tons) 

2014 

(tons) 

2017 

(tons) 

2020 

(tons) 

2023 

(tons) 

Point - total 76,903 26,137 4,379 4,471 4,563

Area - total 753 779 790 802 815

Non-road - total 48 15 1 1 1

Onroad 53 44 31 25 18

Total 77,757 26,975 5,201 5,299 5,397
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Table 5-2. Summary of Projected NOx Emissions – Total of All Sectors (tons) 

Source 

2007 

attainment 

(tons) 

2014 

(tons) 

2017 

(tons) 

2020 

(tons) 

2023 

(tons) 

Point - total 20,586 16,229 14,362 14,671 14,981

Nonpoint - total 958 1,060 1,103 1,147 1,192

Non-road - total 1,428 1,071 917 828 739

Onroad 7,539 6,022 4,072 3,031 1,991

2023 Onroad 

Safety Margin - - - - 196

Total 30,511 24,382 20,454 19,677 19,099

 

Table 5-3. Summary of Projected PM2.5 Emissions – Total of All Sectors (tons) 

Source 

2007 

attainment

(tons) 

2014 

(tons) 

2017 

(tons) 

2020 

(tons) 

2023

(tons) 

Point - total 1,539 1,187 1,037 1,073 1,110

Nonpoint - total 1,516 1,715 1,801 1,878 1,954

Non-road - total 98 73 63 55 48

Onroad 266 213 144 107 70

2023 Onroad 

Safety Margin - - - - 10.3

Total 3,419 3,188 3,045 3,113 3,192

 

The supporting documentation to show that the above conditions have been met for the Macon Area 

is contained in this document. Based on the 2007-2009 monitored design value for the Macon 

nonattainment area, EPA has published in the Federal Register its final rule that the nonattainment 

area has attained the 1997 annual average PM2.5 National Ambient Air Quality Standard (NAAQS). 
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The maintenance demonstration in this document shows that, based on comparison of projected 

emissions to attainment year emissions, emissions are expected to stay at or below levels 

commensurate with attaining air quality through the year 2023 as illustrated by Tables 5-1, 5-2 and 

5-3 above. Analysis was presented to demonstrate that the standard will be maintained despite a 

small projected increase in direct PM2.5 emissions. This document also contains provisions for 

contingency measures should emissions levels or ambient concentrations rise unexpectedly. EPA’s 

concurrence that the improvement in the Macon area’s air quality is due to permanent and 

enforceable reductions in emissions and EPA’s approval of this document will satisfy items 3 and 5 

above. Therefore, Georgia EPD requests that the Macon area be redesignated from nonattainment to 

attainment with respect to the 1997 NAAQS for annual fine particulate matter. In addition, 2023 

MVEBs have been presented for onroad mobile emissions of direct PM2.5 and NOx. These emissions 

budgets are required by EPA’s transportation conformity rule as tools for ensuring conformance of 

highway and transit plans with air quality SIPs and maintenance plans. 
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6.0 References 

State of Georgia, Rules for Air Quality Control, Chapter 391-3-1, Effective September 13, 2011 

US Energy Information Administration, Annual Energy Outlook 2010, April 2010 

USEPA, Air Quality Modeling Final [Cross-state Air Pollution] Rule Technical Support Document, 

June 2011, Docket ID No. EPA-HQ-OAR-2009-0491-4140 

USEPA, “Approval, and Promulgation of Air Quality Implementation Plans; Indiana; Redesignation 

of the Evansville Area to Attainment of the Fine Particulate Matter Standard’; proposed rule, 76 FR 

29695 

USEPA, “Clean Data Policy for the Fine Particle National Ambient Air Quality Standards,” 

Memorandum from Stephen Page, December 14, 2004 

USEPA, “Approval and Promulgation of Implementation Plans and Designations of Areas for Air 

Quality Planning Purposes; Georgia: Macon; Determination of Attaining Data for the 1997 Annual 

Fine Particulate Standard”; final rule; 76 FR 31858 – 31860. 

USEPA, “Federal Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone 

and Correction of SIP Approvals” [a.k.a. “Cross-State Air Pollution Rule”]; final rule, 76 FR 48208 

USEPA, National Emissions Inventory: inventory years 2005, 2007, and 2008 

USEPA, “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum 

from John Calcagni, September 4, 1992