# Attainment Demonstration
Jackson County, Alabama Chattanooga PM 2.5 

# Nonattainment Area

Prepared by Alabama Department of Environmental Management Air Division
August 2009

## Table of Contents

Table of Contents.............................................................................................................. ............... i List of Figures................................................................................................................ ................. ii List of Tables ................................................................................................................. ................. ii EXECUTIVE SUMMARY ............................................................................................................ 1 1.0 Introduction............................................................................................................... .......... 2 1.1 Fine Particulate Matter (PM 2.5 

### )....................................................................................... 2 1.2 PM 2.5 

### National Ambient Air Quality Standard ............................................................... 3 2.0 Chattanooga, Tennessee-Georgia PM 2.5 

### Nonattainment Area............................................ 4 2.1 Nonattainment Area Designations .................................................................................. 4 2.2 PM 2.5 

### Monitoring Stations .............................................................................................. 5 2.3 Trends Analysis ............................................................................................................ .. 6 3.0 Attainment Modeling........................................................................................................ .. 7 4.0 Development of Emission Inventories................................................................................ 8 4.1 Point Source Emissions................................................................................................... 8 4.1.1 2002 Base Case....................................................................................................... 8 4.1.2 2009 Future Year .................................................................................................... 8 4.2 Area Source Emissions ................................................................................................... 9 4.2.1 2002 Base Case....................................................................................................... 9 4.2.2 2009 Future Year .................................................................................................... 9 4.3 Onroad Mobile Source Emissions ................................................................................ 10 4.3.1 2002 Base Case..................................................................................................... 10 4.3.2 2009 Future Year .................................................................................................. 10 4.4 Nonroad Mobile Source Emissions .............................................................................. 11 4.4.1 2002 Base Case..................................................................................................... 11 4.4.2 2009 Future Year .................................................................................................. 11 4.5 Biogenic Source Emissions........................................................................................... 11 4.6 Emissions Summary for the Par tial Area of Jackson County....................................... 12 5.0 Significance of Precursors Contribu ting to Fine Particulate Matter................................. 13 5.1 Nitrogen Dioxides......................................................................................................... 1 3 5.2 Sulfur Dioxides ............................................................................................................ . 13 5.3 Ammonia and Volatile Organic Compounds................................................................ 13 6.0 RACT and RACM ............................................................................................................ 14 7.0 Contingency Measures...................................................................................................... 1 6 8.0 Reasonable Further Progress............................................................................................. 17 9.0 Permanent and Enforceable Improvements in Air Quality............................................... 18 10.0 Insignificance Determination fo r Transportation Conformity.......................................... 19 10.1 Nitrogen Oxides (NO X 

### )................................................................................................. 19 10.1.1 Analysis of motor vehicle NO X 

### emissions in the Jackson County portion of the Chattanooga nonattainment area........................................................................................... 19 10.1.2 The current state of the ai r quality in Jackson County.......................................... 20 10.1.3 The absence of SIP motor vehi cle controls for the area. ...................................... 20 10.1.4 Historical trends and futu re projections of the growth of motor vehicle emissions. 20

iii 

### 10.2 Direct PM 2.5 

### : ................................................................................................................. 21 10.2.1 Analysis of motor vehicle PM 2.5 

### emissions in the Jackson County portion of the Chattanooga nonattainment area........................................................................................... 21 10.2.2 The current state of the ai r quality in Jackson County.......................................... 22 10.2.3 The absence of SIP motor vehi cle controls for the area. ...................................... 22 10.2.4 Historical trends and futu re projections of the growth of motor vehicle emissions. 22 11.0 Summary and Conclusion................................................................................................. 23 

## List of Figures
Figure 2-1 Chattanooga PM 2.5 

### Nonattainment Area....................................................................... 4 Figure 2.2-1 Locations of PM 2.5 

### Monitors in the Chattanooga Nonattainment Area .................... 6 Figure 6-1 Response to 30% reduction in 2009 Base D Emissions.............................................. 15



## List of Tables

Table 1 2009 Modeled Annual PM 2.5 

### Design Values..................................................................... 1 Table 1.2-1 24-Hour PM 2.5 

### Design Values for the Chattanooga NAA.......................................... 3 Table 2.2-1 PM 2.5 

### Annual PM 2.5 

### Design Values............................................................................ 5 Table 3-1 2009 Modeled Annual PM 2.5 

### Design Values................................................................. 7 Table 4.6-1 2002 Emissions for the Partial Nonattainment Area of Jackson County ................. 12 Table 4.6-2 2009 Emissions for the Partial Nonattainment Area of Jackson County ................. 12 Table 6-1 Controls at TVA Widows Creek .................................................................................. 14 Table 10.1.1-1 2002 NO X 

### (TPY) Emissions in the Nonattainment porti on of Jackson County by Source Type .................................................................................................................................. 20 Table 10.1.1-2 2002 NO X 

### (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson County Compared to Total On -road Mobile Source Emissions in the entire Chattanooga NAA......................................................................................................................... 20 Table 10.1.4-1 Historical a nd Future Projections of NO X 

### emissions from On-Road Mobile Sources in Jackson County ........................................................................................................... 21 Table 10.2.1-1 2002 Direct PM 2.5 

### (TPY) Emissions in the Nona ttainment Portion of Jackson County by Source Type ................................................................................................................ 21 Table 10.3.1-2 2002 Direct PM 2.5 

### (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson County Compar ed to Total On-road Mobile Source Emissions in the Entire Chattanooga NAA.................................................................................................... 22 Table 10.2.4-1 Historical a nd Future Projections of PM 2.5 

### emissions from On-Road Mobile Sources in Jackson County ........................................................................................................... 22 Table 11-1 2001 – 2003 PM 2.5 

### Design Values for Chattanooga Nonattainment Area Monitors 23 Table 11-2 PM2.5 2009 Future (Modeled) Design Values.......................................................... 24

## EXECUTIVE SUMMARY
On January 5, 2005, the United States Environmental Protection Agency (EPA) published the fine particulate matter (PM 2.5 ) nonattainment designation for the Chattanooga nonattainment area (NAA). This area consists of Hamilton County in Tennessee, Catoosa and Walker Counties in Georgia, and the portion of Jackson County in Alabama that is described as U.S. Census 2000 block group identifier 01–071-9503–1. There are no PM 2.5 monitors located in the Jackson County, Alabama, portion of the nonattainment area; however, the air quality monitoring data for 2001-2003 from monitors located in the Georgia and Tennessee portions of the nonattainment area indicated that the annual average PM 2.5 concentrations (design values) exceeded the 15.0 μ g/m 3 National Ambient Air Quality Standard (NAAQS). EPA included the above-mentioned portion of Jackson County, Alabam a, in the Chattanooga nonattainment area because they concluded that the TVA Widows Creek Fossil Plant located in the county contributes to the nonattainment situation in the Chattanooga NAA. Subsequently, the Alabama Department of Environmental Management, the Chattanooga-Hamilton County Air Pollution Control Bureau, the Tennessee Division of Air Pollution Control and the Georgia Air Protection Branch have collaborated to develop a PM 2.5 NAAQS State Implementation Plan (SIP) for each jurisdiction. This document contains the SIP for the Jackson County, Alabama, portion of the nonattainment area, which demonstrates attainment of the annual PM 2.5 NAAQS, promulgated in 1997, in the Chattanooga NAA by April 5, 2010. Air quality modeling conducted for the State of Alabama, Hamilton County, Tennessee, and the State of Georgia by the Association for Southeastern Integrated Planning (ASIP) indicates that the nonattainment area will attain the annual PM 2.5 NAAQS beginning in 2009. The model results are based upon projected 2002-2009 emissions reductions from sources within the area and are supported by downward trends in actual emissions. It is expected that the area will attain the PM 2.5 NAAQS based upon implementation of Federal and regional measures. The 2009 modeled PM 2.5 design values are provided below.
Table 1 2009 Modeled Annual PM2.5 Design Values



### Federal Reference Monitor PM 2.5 

### Design Value (μg/m 3 

### )
Siskin Drive/UTC (470654002), TN 13.6 Maxwell Road/East Ridge (470650031), TN 14.4 Soddy-Daisy High School (470651011), TN 12.3 Walker County, GA (132950002) 13.9

1

## 1.0 Introduction

1.1 Fine Particulate Matter (PM 2.5 

### ) Fine particulate matter, also known as fine particles and PM 2.5 , refers to airborne particles less than or equal to 2.5 micrometers ( μ m) in diameter. Fine particles are treated as though they are a single pollutant, but they come from many different sources and are composed of many different compounds. PM 2.5 exposure adversely affects hum an health, especially respiratory and cardiovascular systems. Individuals particularly sensitive to PM 2.5 exposure include children, people with heart and lung disease, and older adults.
PM 2.5 can be liquid, solid, or can have a solid core surrounded by liquid. PM 2.5 can include material produced by combustion, photochemical r eactions, and can contain salt from sea spray and soil like particles. Particles are distinguished based on the method of formation. Primary particles are particles directly emitted into the atmosphere and retain the same chemical composition as when they were released. Secondary particles are those formed through chemical reactions involving atmospheric oxygen, water vapor, hydroxyl radical, nitrates, sulfur dioxide (SO 2 ), nitrogen oxides (NO X ), and organic gases from natural and anthropogenic sources. PM 2.5 can therefore be composed of varying amount of different species, including:

• Sulfates

• Nitrates (usually found in the form of ammonium nitrate)

• Ammonium

• Hydrogen ion

• Particle bound water

• Elemental carbon

• Organic compounds

o Primary organic species (from cooking and combustion)

o Secondary organic compounds

• Crustal material (includes calcium, aluminum, silicon, magnesium, and iron)

• Sea salt (generally only found at coastal monitoring sites)

• Transitional metals

• Potassium (generally from wood burning or cooking) The most significant sources of PM 2.5 and its precursors are coal-fired utilities, industrial boilers, and other combustion sources. These emissions are often transported over large distances. Other sources of PM 2.5 emissions include mobile sources, area sources, biogenic sources, fires, wind blown dust, and oceans. A variety of meteorological and geographic factors influence the concentration levels of fine particles, including both the regional and local distribution of urbanized areas, primary and precursor emissions sources, and natural features such as oceans and forests. Since PM 2.5 concentrations can exceed the National Ambient Air Quality Standards (NAAQS) at any time of the year, the United States Environmental Protection Agency (EPA) mandates the year round monitoring of the pollutant throughout the country (40 CFR 58, App. D).

2

### 1.2 PM 2.5 

### National Ambient Ai r Quality StandardIn July 1997, the EPA established both annual and 24-hour fine particulate primary (healthbased) and secondary NAAQS for annual and 24-hour fine particulate (62 FR 38711 and 40 CFR 50.7). The secondary PM 2.5 standards, established for the protection of public welfare and the environment, were established at the same levels as the primary standards. After review, the EPA revised the 24-hour standard in October 2006, but the annual standard remained the same. The 24-hour standard (as revised in 2006) is met when the 3-year average of a monitoring site's annual 98th percentile value is 35 micrograms per cubic meter ( μ g/m 3 ) or less. The annual standard is met when the 3-year average of a monitoring site's annual mean concentration is 15.0 μ g/m 3 or less. The 3-year averages at each monitoring site (of annual means or 98 th percentiles) are called design values. The design value for an entire area is the single highest design value among the monitoring sites located in the area. Since the 1977 amendments to the Clean Air Act (CAA), areas of the country that violated the ambient standard for a particular pollutant were formally designated as nonattainment for that pollutant. This formal designation concept was retained in the 1990 Amendments (CAAA). With the implementation of the PM 2.5 standard, areas designated nonattainment under Section 172 of the CAAA (Subpart 1) have five years from designation to attain the standard. Federal regulations require that in “any area designated as nonattainment for the PM 2.5 NAAQS, the State must submit an attainment demonstration showing that the area will attain the annual and 24-hour standards as expeditiously as practicable.” [40 CFR 51.1007(a)] As seen in table 1.2-1 below, all monitors in the Chattanooga NAA attain the 1997 24-hour PM 2.5 standard of 65 μ g/m 3 . While the Chattanooga area is in compliance with the 1997 24-hour PM 2.5 NAAQS, measures implemented through this SIP for achieving attainment with the annual standard will have a co-benefit for the 24-hour standard.
Table 1.2-1 24-Hour PM2.5 Design Values for the Chattanooga NAA



### PM2.5 Design Value ( μ g/m3) Federal Reference Monitor 2001-2003* 2002-2004 2003-2005 2004-2006 

### Siskin Drive/UTC (470654002), TN 35 33 34 32 Maxwell Road/East Ridge (470650031), TN 37 34 35 32 Soddy-Daisy High School (470651011), TN 34 30 31 28 Walker County, GA (132950002) 33 32 33 29

* Averaging period used by the EPA in the nonattainment area designation

3

## 2.0 Chattanooga, Tennessee-Georgi a PM2.5 Nonattainment Area
On January 5, 2005, EPA published the annual PM 2.5 nonattainment designation for the Chattanooga, Tennessee-Georgia area. This area consists of Hamilton County in Tennessee, Catoosa and Walker Counties in Georgia, and the portion of Jackson County in Alabama that is described as U.S. Census 2000 block group identifier 01–071-9503–1. Figure 2-1 illustrates the nonattainment area boundaries. Although Jackson County is not contiguous to the rest of the nonattainment area, EPA concluded that a coal-fired power plant located in this census tract contributed to the PM 2.5 problem in the Chattanooga area. The effective date of the nonattainment designation was April 5, 2005, and was based on air quality monitoring for the years 2001, 2002, and 2003.

Figure 2-1 Chattanooga PM2.5 Nonattainment Area



### 2.1 Nonattainment Area Designations EPA, based on monitoring data submissions from states and tribes, designates a county as attainment/unclassifiable or nonattainment. In addition, a county is designated as nonattainment if it is deemed to contain sources that contribute to the nonattainment status of a county.

4Nonattainment counties are initially gr ouped based on presumptive boundaries. These boundaries are based metropolitan statistical areas (MSAs) or combined statistical areas (CSAs). If a county within a MSA or CSA possesses a violating monitor, the entire area is presumed to be in nonattainment of the NAAQS. The state(s) is given the opportunity to provide EPA with evidence indicating that certain counties in the CSA should be omitted from the nonattainment area using 9-factors specifie d by EPA. EPA made the initial nonattainment designation of the Chattanooga NAA for the annual PM 2.5 NAAQS on January 5, 2005 (70 FR 944), and amended the designations on April 5, 2005 (70 FR 19844). The Alabama portion of the Chattanooga NAA is made up of a single census block located in Jackson County. The designation of a portion of Jackson County as a part of the Chattanooga nonattainment area was based upon EPA’s conclusion that a power plant located in the county was contributing to the PM 2.5 violations occurring in the Chattanooga NAA.



### 2.2 PM 2.5 

### Monitoring Stations While there are no monitors currently located in Jackson County, AL, the observed annual PM 2.5 design values at three of the four nonattainment area monitors located in Georgia and Tennessee violated the annual standard for 2001 – 2003; the period on which nonattainment designations were based. Three of the monitors are located in Hamilton County, Tennessee, and one is located in Walker County, Georgia. Georgia currently has one ambient PM 2.5 monitoring site in the Chattanooga, TennesseeGeorgia nonattainment area, as shown in Ta ble 2.2-1 and Figure 2.2-1. The Rossville-Maple Street site is in Walker County, GA.

Table 2.2-1 Annual PM 2.5 Design Values 

### PM2.5 Design Value ( μ g/m3) Federal Reference Monitor 2001-2003* 2002-2004 2003-2005 2004-2006 

### Siskin Drive/UTC (470654002), TN 15.2 14.7 15.0 15.1 Maxwell Road/East Ridge (470650031), TN 16.1 15.7 16.1 15.5 Soddy-Daisy High School (470651011), TN 14.1 13.8 13.8 13.5 Walker County, GA (1 32950002) 15.5 15.2 15.8 15.2

* Averaging period used by the EPA in the nonattainment area designation
For a full discussion of PM 2.5 monitoring performed in the Georgia portion of the NAA, please see Section 2.2 of the Georgia SIP located in Appendix 2. For a full discussion of the PM 2.5 monitoring performed in the Tennessee portion of the NAA, please see Section 1.3 of the Tennessee SIP located in Appendix 1.

5Figure 2.2-1 

### Locations of PM 2.5 

### Monitors in the Chattanooga Nonattainment Area



### 2.3 Trends Analysis Overall, there has been a general downward long-term trend in PM 2.5 concentrations at most monitors in the Chattanooga NAA. Detailed information regarding these trends can be found in Section 2.3.1 of the GA SIP located in Appendix 2.

6

## 3.0 Attainment Modeling
In 2001, the southeastern states formed the Visibility Improvement State and Tribal Association of the Southeast (VISTAS) to address compliance with the Regional Haze Rule that was published in 1999 (64 FR 35714). The member states are Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia. VISTAS found that the modeling requirements for the Regional Haze Rule were similar to the requirements for the modeled attainment demonstration for PM 2.5 nonattainment areas. The member states formed a new organization, the Association for Southeastern Integrated Planning (ASIP), in order to conduct modeled attainment demonstrations for the PM 2.5 nonattainment areas. VISTAS and ASIP used the same emissions inventory and model. A detailed description of the attainment modeling methodology used by Alabama, Georgia and Tennessee to evaluate the Chattanooga annual PM 2.5 nonattainment area and the resulting conclusions can be found in Sections 2 and 3 of the TN SIP and Sections 3, 4 and 6 of the GA SIP located in Appendices 1 and 2, respectively. The results of the attainment demonstration modeling for the Chattanooga NAA are shown in the Table 3-1 below. All PM 2.5 monitors in the NAA are expected to meet the annual PM 2.5 NAAQS beginning in 2009.

Table 3-1 2009 Modeled Annual PM2.5 Design Values

Federal Reference Monitor PM 2.5 Design Value (μg/m 3 ) Siskin Drive/UTC (470654002), TN 13.6 Maxwell Road/East Ridge (470650031), TN 14.4 Soddy-Daisy High School (470651011), TN 12.3 Walker County, GA (132950002) 13.9

Control measures for attainment focus on control of SO 2 (and therefore sulfates) from utilities. The most significant state-specific measure is the Georgia multi-pollutant rule. Federal measures include the following:

• Clean Air Interstate Rule

• Tier 2 Vehicle Standards

• Heavy-duty Gasoline and Diesel Highway Vehicles Standards

• Ultra Low Sulfur Diesel Fuel Rule

• Large Non-road Diesel Engine and Fuel Standards

• Non-road Spark Ignition Engines and Recreational Engines Standards

• NO X SIP Call in Surrounding States

7

## 4.0 Development of Emis sion Inventories
This section describes the methodologies and data used to prepare the 2002 base case, and the 2009 and 2012 future year emissions inventories.



### 4.1 Point Source Emissions

4.1.1 2002 Base Case

4.1.1.1 Non-EGU Point Sources The starting point for the 2002 Base G2 emission inventory was EPA’s 1999 National Emission Inventory (NEI). The 1999 data was supplemented with more recent inventories submitted by state and local agencies and was ultimately replaced with data submitted by VISTAS/ASIP States pursuant to the Consolidated Emissions Reporting Rule (CERR) and included in the 2002 NEI. The 2002 Base G2 emission inventory was released in August 2006 and incorporated updates and corrections to the 2002 NEI inventory. Changes for Alabama included the correction of latitude and longitude values; identification of closed facilities with non-zero emissions reported in the NEI; and updating emissions for several facilities, based on the most recently reported information.

4.1.1.2 EGU Point Sources For point sources, the 2002 base year inventory includes both actual emissions for coal-fired electric utilities and a “typical” year inventory. Actual emissions from 2002 were obtained from EPA’s Clean Air Markets Division (CAMD). The “t ypical year” point source inventory was developed to smooth out any anomalies in utilit y emissions due to meteorological, economic, and outage factors in 2002. The 2002 “typical” base year emissions inventory for EGUs was developed using CAMD data to develop normalizat ion factors for the 2002 typical emissions inventory. VISTAS/ASIP used the actual 2002 heat input and the average heat input for the 5- year period from 2000-2004 as the normalization factor, as follows: Normalization Factor = (2000-2004 average heat input) 2002 actual heat input If the unit did not operate for all five years from 2000-2004, then the average heat input was calculated for the years in which the unit did operate. Actual emissions for 2002 were multiplied by the normalization factor to determine t he typical emissions for 2002, as follows: Typical Emissions = (2002 actual emissions)(Normalization Factor) For the entire VISTAS/ASIP region, actual 2002 SO 2 emissions were about 0.5 percent higher than the typical year emissions.

4.1.2 2009 Future Year Different approaches were used to develop the point source inventory for EGUs and non-EGUs. For EGUs, Integrated Planning Model ® (IPM ® ) results were used to project future generation and to calculate the impact of future emission c ontrol programs. IPM results were adjusted as necessary to account for planned emission controls at specific EGUs. For non-EGUs, the 2009 inventory was based on updated growth and control data, supplemented with State/Localagency input and updated fuel use forecast data from the U.S. Department of Energy. Post2002 facility shutdowns were also noted in the 2009 inventory.

8For both sectors, 2009 inventories were generated using a combined on-the-books (OTB) and on-the-way (OTW) control scenario. The OTB/OTW control scenario accounted for post-2002 emission reductions from promulgated and proposed Federal, State, local and site specific control programs as of July 1, 2004.



### 4.2 Area Source Emissions

4.2.1 2002 Base Case
The area source sector of the emissions invent ory consisted of three components: development of a typical-year fire inventory; incorporation of data submitted by states to EPA pursuant to the CERR; and development of NH 3 emission estimates for livestock and fertilizers and paved road PM emissions. Development of a typical-year fire inventory provided the capability of using a comparable data set for both the base year and future years. Since fire emissions are not easily grown or projected, VISTAS determined that a typical-year fire inventory was needed to effectively represent fires in the base and future year inventories. Development of the typical-year fireinventory covered wildfire, prescribed burning, agricultural fires and land clearing fires. Typicalyear fire emissions were developed from actual fire acreage data and emissions were calculated for each state in the VISTAS/ASIP region. The second component of the area source inventory was the incorporation of CERR data submitted by states to EPA. The CERR data work involved: 1) obtaining data from EPA; 2) evaluating reported pollutants and emissions to avoid double-counting; and 3) adding missing sources/pollutants, as necessary. The final component of the area source inventory was related to the development of ammonia emission estimates for livestock and fertilizers and the estimate(s) of paved road PM emissions. Version 3.6 of the Carnegie Mellon University (CMU) ammonia model was used to estimate livestock and fertilizer emissions. For paved road PM estimates, VISTAS/ASIP used the most recent EPA estimates developed in the 2002 NEI.

4.2.2 2009 Future YearThe 2002 base year inventory was used as the starting point for projections. For nonagricultural sources, the VISTAS/ASIP contractor worked with states to obtain state-specific growth factors and future control requirements. Uncontrolled emissions were obtained from the 2002 inventory and control requirements were then added to calculate controlled emissions. Growth factors were obtained from states or from EPA’s CAIR 1 emission projections, and these factors were applied to project the controlled emissions to the future year. If no state or CAIR growth factor was available, then EGAS Version 5 growth factors were used. The final inventory was then submitted to the VISTAS/ASIP States for review and comment. To calculate projected emissions for agricultural area sources (predominantly ammonia), VISTAS/ASIP used the 2002 base year inventory data and obtained state-specific growth factors from individual states. Since base year emissions were uncontrolled, and no future controls were identified for agricultural sources, VISTAS/ASIP projected the agricultural

1 On December 23, 2008, the United States Court of Appeals for the District of Columbia Circuit remanded CAIR to EPA without vacatur, directing the Agency to remedy the rule ’s flaws in accordance with the Court’s July 11, 2008, opinion in the case of North Carolina v. EPA, 531 F. 3d 896, 901 (D.C. Cir. 2008). When EPA responds to the Court’s remand, the SIP may need to be revised to be consistent with the Agency’s new final action.

9emissions using state-specific growth or U.S. EPA’s Interstate Air Quality Transport Rule (IAQTR) ammonia inventory. The final inventory was submitted to the VISTAS/ASIP States for review and comment. The 2009 emissions inventory for fires was updated to account for increased prescribed fire burning by federal agencies in future years. VISTAS/ASIP developed an updated Base G2 fire inventory for 2009 to capture the projected increases.



### 4.3 Onroad Mobile Source Emissions

4.3.1 2002 Base Case The MOBILE6 module of the Sparse Matrix Oper ator Kernel Emissions (SMOKE) model was used to develop the onroad mobile source emissions estimates for CO, NO X , NH 3 , SO 2 , PM, and VOC emissions. The MOBILE6 parameters, vehicle fleet descriptions, and Vehicle Miles Traveled (VMT) estimates were combined with gridded, episode-specific temperature data to calculate the gridded, temporalized emission estimates. The emission factors model included the following variables: • Hourly and daily minimum/maximum temperatures; • Facility speeds; • Inspection/maintenance (I/M) control programs, if any; • Adjustments for running losses; • Splitting of evaporative and exhaust emissions into separate source categories; • VMT, fleet turnover, and changes in fuel composition and Reid Vapor Pressure. The primary input to MOBILE6 was the MOBILE shell file, which contained the various options to direct the calculation of the MOBILE6 emissions factors (e.g., type of inspection and maintenance program, oxygenated fuel program in effect, alternative vehicle mix profiles, Reid Vapor Pressure of in-use fuel, operating mode). Onroad mobile source emissions were produced using selected weeks (seven days) of each month and using these days as representative of the entire month. This selectio n criterion allowed for the representation of dayof-the-week variability in the onroad motor vehicles, and models a representation of the meteorological variability in each month. The modeled weeks were selected from mid-month, avoiding inclusion of major holidays.

4.3.2 2009 Future Year To develop the future year projections, VISTAS/ASIP assembled data to develop 2009 future year inventories from: 1) an inventory that included all OTB control programs; and 2) an inventory that included controls that were likely to be OTW. For the 2009 emission forecasts to the mobile source sector, OTB and OTW were defined with the same strategies; therefore, only a single projection scenario was developed for the forecast year. To ensure consistency across evaluation years, the 2009 inventory was developed, to the maximum extent practical, using methodologies identical to those employed in developing the 2002 onroad portion of the revised 2002 base year inventory. The methodology used to generate the 2009 VMT for use in estimating onroad mobile source emissions was as follows:
1. All estimates started from the final VMT estimates used for the 2002 revised base year inventory;

102. Initial 2009 VMT estimates were based on linear growth rates for each state, county, and vehicle type, as derived from the VMT dat a assembled by EPA for the most recent HDD (heavy duty diesel) rulemaking.



### 4.4 Nonroad Mobile Source Emissions

4.4.1 2002 Base Case Emissions from nonroad sources were estimated in two steps. First, emissions for nonroad sources that were included in the NONROAD model were developed. Second, emissions from sources not included in the NONROAD model were estimated. An initial 2002 base year emissions inventory for nonroad engines and equi pment covered by the EPA NONROAD model was prepared for VISTAS in early 2004. Revisions to the emissions inventory were implemented to ensure that the latest state and local data were considered and to accurately reflect gasoline sulfur contents for 2002.

4.4.2 2009 Future Year Nonroad mobile source emissions were developed for 2009 in the same fashion as they were developed for 2002. The final version of the NONROAD2005 model was used for the 2009 projections. Other specific updates for the projection years for NONROAD model sources consisted of: 1. Changes to the emissions inventory year in the model to be reflective of the projection year; 2. Revisions to the fuel sulfur content for gasoline- and diesel-powered equipment; and 3. Implementation of a limited number of local control program changes (most national control program changes are handled internally within the NONROAD model, so explicit input file changes are not required). All equipment, population growth and fleet turnover impacts are also handled internally within the NONROAD model, so that explicit changes to the input files are not required. To correctly account for diesel fuel sulfur content differences between the base and projection years, two sets of input and output files were prepared for each forecast year, one set for land-based equipment and one set for marine equipment. To correctly account for the national reduction in gasoline sulfur content (a national control not explicitly handled by the NONROAD model), all NONROAD input files for 2009 were revised to reflect a gasoline fuel sulfur content of 30 ppm. Those sources requiring emissions estimate d outside the NONROAD model (locomotives, airplanes and commercial marine vessels) were projected through a combination of applied technological reductions and growth due to increased demand on these sectors. Further details are contained in Appendices G and H of Georgia’s SIP, located in Appendix 2.



### 4.5 Biogenic Source Emissions Biogenic emissions were prepared with the SM OKE-BEIS3 (Biogenic Emission Inventory System 3 version 0.9) preprocessor. SMOKE-BEIS3 is a modified version of the Urban Airshed Model (UAM)-BEIS3 model. Modifications include use of MM5 data, gridded land-use data, and improved emissions characterization. The emission factors that were used in SMOKE-BEIS3 were the same as the emission factors in UAM-BEIS3. The basis for the gridded land-use data used by BEIS3 is the county land-use data in the Biogenic Emissions Landcover Database

11version 3 (BELD3) provided by EPA. A sepa rate land classification scheme, based upon satellite (AVHRR, 1 km spatial resolution) and census information, aided in defining the forest, agriculture and urban portions of each county.



### 4.6 Emissions Summary for the Part ial Area of Jackson County

Table 4.6-1 2002 Emissions for the Partial Nonattainment Area of Jackson County 2002 Jackson County -Partial (TPY) Sector VOC NO X SO 2 PM 2.5 NH 3 Point 144 26,337 44,080 933 2 Area 33 3 17 12 14 Non-road 16 14 5 1 0 Mobile 18 7 6 0 0 Total 211 26,361 44,108 946 16

Table 4.6-2 2009 Emissions for the Partial Nonattainment Area of Jackson County 2009 Jackson County -Partial (TPY) Sector VOC NO X SO 2 PM 2.5 NH 3 Point 177 5,157 45,356 1,124 8 Area 24 3 16 12 14 Non-road 13 13 2 2 0 Mobile 11 5 1 0 1 Total 252 5,178 45,375 1,138 23

12

## 5.0 Significance of Precursors Contributi ng to Fine Particulate Matter
EPA, in 72 FR 20586, requires states to “evaluate and consider control strategies for sources of SO 2 , direct PM 2.5 and NO X emissions in all nonattainment areas.” However, the rule does allow states to make technical demonstrations to reverse the inclusion of NO X as precursor of PM 2.5 , or deem the precursor insignificant, based on geographical regions, emissions, etc. The two remaining precursor species that contribute to PM 2.5 formation, ammonia (NH 3 ) and volatile organic carbons (VOCs), have been deemed as insignificant contributors to the total mass of PM 2.5 by EPA. With regards to NH 3 , 72 FR 20586 states NH 3 “is presumed not to be a PM 2.5 attainment plan precursor, meaning that the State is not required to address [NH 3 ] in its attainment plan or evaluate sources of [NH 3 ] emissions for reduction measures.” Likewise, the final rule for VOCs states that “States are not required to address VOC in PM 2.5 implementation plans and evaluate control measures for such pollutants unless the State or EPA makes a technical demonstration that emissions of VO Cs from sources in the State significantly contribute to PM 2.5 concentrations in a given nonattainment area.”



### 5.1 Nitrogen Dioxides Analysis performed by both the Chattanooga-Ha milton County Air Pollution Control Bureau and Georgia Department of Natural Resources Environmental Protection Division indicate that control of NO X in the Chattanooga nonattainment area would be expected to result in an insignificant reduction in PM 2.5 levels. Please see Appendices 1 and 2 for the analyses performed by these agencies. These analyses further support ADEM’s conclusion that no additional reductions in NO X emissions in the Jackson County, Alabama, partial NAA are warranted or reasonable beyond the reductions result ing from national programs such as CAIR and mobile source control programs. Additional information concerning NO X emissions can be found in the RACT analyses in Section 6.



### 5.2 Sulfur Dioxides As discussed previously, SO 2 is an important precursor to the formation of PM 2.5 and has a strong regional impact on PM 2.5 concentrations. The RACT/RACM analysis for SO 2 can be found in Section 6.



### 5.3 Ammonia and Volatile Organic Compounds The State of Alabama agrees with EPA’s presumptive exclusion of NH 3 and VOC with regards to this PM 2.5 SIP. Therefore, emission controls for NH 3 and VOC were not considered part of Alabama’s PM 2.5 attainment demonstration plan.

13

## 6.0 RACT and RACM
Section 172 (c)(1) of the CAA requires SIPS to provide for the implementation of all reasonably available control measures (RACM) that cont ribute to attainment as “expeditiously as practicable” in the specific nonattainment area. The EPA has consistently interpreted RACM as a collection of measures that would advance t he attainment date by at least 1 year. This requirement also applies to emissions reductions from existing stationary sources through the adoption of reasonably available control technology (RACT). “Reasonably available” allows the state to consider both the cost and benefits of applying the measure and whether the measure can be readily and effectively implemented without undue administrative burden. EPA included one Jackson County, Alabama, cens us block in the Chattanooga NAA because they concluded that the TVA Widows Creek utility contributes to nonattainment of the annual PM 2.5 NAAQS in the Chattanooga NAA. The TVA Widows Creek facility is subject to CAIR. Table 6-1 lists the controls as well as installation dates of current control equipment for the TVA Widows Creek facility. SCRs were installed on the two largest units in 2003 and 2004. Also, since 2002, FGD was upgraded in efficiency on one of the two largest units.

Table 6-1 Controls at TVA Widows Creek

Rated Initial Initial Initial Capacity NOx Service SO2 Service PM Service

(MW) Strategy Year Strategy Year Strategy Year Tennessee Valley Authority

Widows Creek WCF U1-6 141 each LLNB 2004 FS CS- ESPs

WCF U7 575 SCR (LNB) 2003 FGD 1984 CS-ESP

WCF U8 550 SCR (LNB) 2004 FGD 1977*
*-The FGD installed on unit 8 was upgraded in efficiency in 2004.

Units 7 and 8 are base load units and units 1-6 are peaking units. As shown in the table, 100% of the base load generating capacity of this facility has SCR and FGD controls. The attainment demonstrations that have been prepared by the State of Georgia and the Chattanooga local program indicate that the area will attain the annual fine particle NAAQS at the 2009 emissions levels projected from Widows Creek and all other sources in the area. Since the 2009 emissions levels reflect the implementation of the Clean Air Interstate Rule and other National emissions reductions programs, ADEM concludes that currently no additional controls are needed at the Widows Creek facility and that CAIR equals RACT for SO 2 and NO X
. In the CAIR rule, EPA determined "that the earliest reasonable deadline for compliance with the final highly cost effective control levels for reducing emissions was 2015..." (70 FR 25197- 25198, May 12, 2005). ADEM believes the cost of compliance and the time necessary for compliance are the dominant factors for determining if additional reductions would be reasonable from CAIR-subject EGUs. Based on the detailed analyses in the May 12, 2005, CAIR rule, ADEM concludes that CAIR controls satisfy RACT for SO 2 and NO X for utilities. Sensitivity modeling performed by ASIP indicates that if ground-level and point source emissions of particulate in Alabama are reduced by 30%, annual PM 2.5 concentrations in the Chattanooga NAA would not be significantly affected (See Figure 6-1). Therefore, ADEM

14concludes that no additional reductions in emissions of particulate are needed to attain the annual PM2.5 NAAQS in the Chattanooga NAA.

Figure 6-1 Response to 30% reduction in 2009 Base D Emissions

15

## 7.0 Contingency Measures

The PM 2.5 Implementation Rule requires contingency measures that would take effect in the event that a nonattainment area fails to meet the PM 2.5 NAAQS. These contingency measures must be fully adopted rules or control measures that are ready to be implemented quickly upon failure of an area to meet the standard by the attainment date. Georgia Rules for Air Quality Control Chapter 391-3-1 Rule (sss) “Multipollutant Control of Electric Steam Generating Units” requires additional power plant SO 2 emission reductions after the end of 2008. Bowen Plant Unit 1 is required to be equipped with flue gas desulfurization by June 1, 2010. The SO 2 emissions reductions expected from this unit are 33,135 tons per year or 19,328 tons reduction in the last seven months of 2010. These reductions were not modeled for 2009. The reductions are not required to demonstrate attainment of the annual PM 2.5 standard, but constitute contingency measures.

16

## 8.0 Reasonable Further Progress
Clean Air Act §172(c)(2) requires plans for nonattainment areas to require “reasonable further progress,’’ (RFP) as defined in CAA §171(1). The Act requires nonattainment areas to make “such annual incremental reductions in emissions of the relevant air pollutant as are required by this part or may reasonably be required by the Administrator for the purpose of ensuring attainment of the applicable national ambient air quality standard by the applicable date.” In general terms, the goal of RFP is to allow areas to achieve generally linear progress toward attainment. The RFP requirements were included in the CAA to assure steady progress toward attaining air quality standards, as opposed to deferring implementation of all measures until the end date by which the standard is to be attained. 40 CFR §51.1009 states that, consistent with CAA §172(c)(2), SIPs for PM 2.5 nonattainment areas must demonstrate reasonable further progress as provided in §51.1009(b) through (h). Paragraph (b) of that section states that “If the State submits to EPA an attainment demonstration and State implementation plan for an area which demonstrates that it will attain the PM NAAQS within five years of the date of designation, the State is not required to submit a separate RFP plan. Compliance with the emission reduction measures in the attainment demonstration and State implementation plan will meet the requirements for achieving reasonable further progress for the area.” Consistent with the provisions of §51.1009(b), Hamilton County, TN, the State of Georgia and ADEM have submitted SIPs that demonstrate that the Chattanooga nonattainment area will attain the annual PM 2.5 NAAQS within five years of designation. Therefore, no additional provisions for RFP are required. Compliance with the emission reduction measures in the AL, TN and GA SIPs will meet the requirements for achieving reasonable further progress for the Chattanooga nonattainment area.

17

## 9.0 Permanent and Enforceable Impr ovements in Air Quality
Since 2000, there have been several major federal programs enacted that have led to significant actual, enforceable PM 2.5 and PM 2.5 precursor emission reductions. These programs were established to provide reductions in emissions from the mobile source and industrial sectors. These programs are listed below. A more detailed discussion can be found in Section 5.1 of the Georgia SIP located in Appendix 2.
1. Tier II Motor Vehicle Emissions Standards
2. Federal Onroad Diesel Engine Standards
3. Federal Nonroad Diesel Engine Standards
4. Federal Marine Engine Requirements
5. Federal Locomotive Requirements
6. The New Source Performance Standards under Section 111 (42 U.S.C 7411)
7. The National Emission Standards for Hazardous Air Pollutants (NESHAP) under Section 112 (42 U.S.C. 7412)
8. The NO X SIP Call
9. The Clean Air Interstate Rule (CAIR) After December 1, 2014, all onroad, nonroad, locomotive and marine diesel fuel produced and imported will be Ultra-Low Sulfur Diesel (ULSD-15 ppm).

18

## 10.0 Insignificance Determination for Transportation Conformity
This section demonstrates that emissions of nitrogen oxides (NO X ), and direct fine particles (PM 2.5 ) from mobile sources in the small portion of Jackson County designated by EPA as nonattainment for the annual fine particle NAAQS, are an insignificant contributor to nonattainment of the annual PM 2.5 NAAQS. EPA designated a small portion of Jackson County, Alabama, as nonattainment for the annual PM 2.5 NAAQS on December 17, 2004. Jackson County was designated as part of the Chattanooga, Tennessee, annual PM 2.5 nonattainment area. According to EPA, the small portion of Jackson County, which includes the Widows Creek Steam Plant, was included in the Chattanooga nonattainment area because they belie ved that emissions from this utility contribute to nonattainment in Chattanooga. The technical support document for the December 17, 2004, designations states “Additionally we have included in our recommended nonattainment area Jackson County, AL, that is adjacent to the Chattanooga MSA, that is generally rural in character, and that contains an identifiable large emitting facility or facilities (e.g., power plants) which we believe contribute to the nearby nonattainment problem.” Therefore, it should be noted that the small portion of Jackson County was included in the Chattanooga nonattainment area because of EPA concerns related to utility emissions and not because of concerns related to mobile source emissions in the county. According to 40 CFR 93.109(k), there are several factors that are used to support a finding of insignificance for these transportation-related PM 2.5 precursor pollutants. The first factor is the percentage of motor vehicle emissions in the cont ext of the total SIP inventory. The second factor is the current state of the air quality in the area. The third factor is the absence of SIP motor vehicle emission control measures. Lastly, historical trends and future projections of the growth of motor vehicle emissions are reviewed. These factors are discussed in detail in the sections to follow. Each section supports the insignificance of NO X and direct PM 2.5 emissions from mobile sources in the Jackson County portion of the nonattainment area under the transportation conformity rule for the PM 2.5 NAAQS.



### 10.1 Nitrogen Oxides (NO X



### )

10.1.1 Analysis of motor vehicle NO X

emissions in the Jackson County portion of the Chattanooga nonattainment area. Only a small portion of Jackson County, Alabama, was included in the Chattanooga PM 2.5 nonattainment area. The small portion of the county designated nonattainment contains a limited number of roads. In order to determine the on-road emissions of NO X from motor vehicles in that portion of Jackson County, the document titled “Chattanooga Nonattainment Area Year 2030 Conformity Determination Report for Particulate Matter (PM 2.5 )” was used to determine how emissions were calculated for Jackson County and the same methodology was applied in this analysis. In order to estimate on-road mobile source emissions for the nonattainment portion of Jackson County, a ratio of the size of the nonattainment portion of Jackson County in square miles to the size of the entire county in square miles was calculated. The nonattainment portion of Jackson County was determined to be only about one percent of the total area of the entire county. The same ratio was applied to obtain area and non-road mobile source emissions for the nonattainment portion of the county. The following table shows the small percentage of NO X emissions from on-road mobile sources as compared to NO X emissions from all other sources in the Ja ckson County portion of the nonattainment area. Emission data were obtained from the VISTAS 2002 “best and final” emissions inventory.

19Table 10.1.1-1 2002 NO X (TPY) Emissions in the Nonattainment portion of Jackson County by Source Type 

### Source Emissions (TPY) Percentage of Total

Area 3.1 <1% Point 26337.4 99.9% Non-Road Mobile 14.18 <1% On-Road Mobile 6.97 <1% Total 26361.65

As the above table demonstrates, NO X emissions from on-road mobile sources in the nonattainment portion of Jackson County are less than 1% of the total NO X emissions from all source categories in the same area. In the table below, a comparison is made of the mobile source NO X emissions from the nonattainment portion of Jackson County to total mobile source NO X emissions for the entire Chattanooga nonattainment area.

Table 10.1.1-2 2002 NO X (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson County Compared to Total On-road Mobile Source Emissions in the entire Chattanooga NAA 

### Emissions (TPY) Percentage of Total Jackson County NAA Portion 6.97 <1%
Chattanooga NAA 13977.73 As the table above demonstrates, NO X emissions from on-road mob ile sources in the Jackson County portion of the nonattainment area are less than 1% of the total NO X emissions from onroad mobile sources in the entire Chattanooga nonattainment area.

10.1.2 The current state of the air quality in Jackson County. As stated earlier in this document, the small portion of Jackson County, Alabama, was included in the Chattanooga PM 2.5 nonattainment area due to the fact that a power plant is located in that area and it was thought by EPA to contribute to the PM 2.5 problem in Chattanooga. There are no PM 2.5 monitors located in Jackson County. Monitors in Alabama near Jackson County have monitored values below the annual PM 2.5 NAAQS. Other counties surrounding the county are either in attainment or unclassifiable.

10.1.3 The absence of SIP motor vehicle controls for the area. There are no SIP motor vehicle controls for Jackson County.

10.1.4 Historical trends and future projections of the growth of motor vehicle emissions. The “Chattanooga Non-Attainment Area Year 2030 Conformity Determination Report for Particulate Matter (PM 2.5 )” was used to obtain past and future projections of the growth in NO X emissions from on-road mobile sources. As dem onstrated in the table below, future emissions of NO X are expected to decrease.

20Table 10.1.4-1 Historical and Future Projections of NO X emissions from On-Road Mobile Sources in Jackson County


### Year Emissions (TPY) 2002 6.97 2010 3.40 2020 1.35 2030 0.96

10.2 Direct PM 2.5 

### :

10.2.1 Analysis of motor vehicle PM 2.5 emissions in the Jackson County portion of the Chattanooga nonattainment area Only a small portion of Jackson County, Alabama, was included in the Chattanooga PM 2.5 nonattainment area. The portion designated as nonattainment contains a limited number of roads. In order to determine the on-road emissions of PM 2.5 from motor vehicles in that portion of Jackson County, the document titled “Chattanooga Non-Attainment Area Year 2030 Conformity Determination Report for Particulate Matter (PM 2.5 )” was used to determine how emissions were calculated for Jackson County and the same methodology was applied in this analysis. In order to estimate on-road mobile source emissions for the nonattainment portion of Jackson County, a ratio of the size of the nonattainment portion of Jackson County in square miles to the size of the entire county in square miles was calculated. The nonattainment portion of Jackson County was determined to be only about one percent of the total area of Jackson County. The same ratio was applied to obtain area and non-road mobile source emissions for the nonattainment portion of the county. The following table shows the small percentage of PM 2.5 emissions from on-road mobile sources as compared to PM 2.5 emissions from all other sources in the nonattainment portion of Jackson County. Emission data were obtained from the VISTAS 2002 best and final inventory.

Table 10.2.1-1 2002 Direct PM 2.5 (TPY) Emissions in the Nonattainment Portion of Jackson County by Source Type 

### Source Emissions (TPY) Percentage of Total

Area 12.09 <1% Point 932.51 98.6% Non-Road Mobile 0.882 <1% On-Road Mobile 0.145 <1% Total 945.63

As the above table demonstrates, direct PM 2.5 emissions from on-road mobile sources in the nonattainment portion of Jackson County are less than 1% of the total direct PM 2.5 emissions from all source categories in the same area. In the table below, a comparison is made of the mobile source direct PM 2.5 emissions from the nonattainment portion of Jackson County to total mobile source PM 2.5 emissions for the entire Chattanooga nonattainment area.

21Table 10.2.1-2 2002 Direct PM 2.5 (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson County Compared to Total On-road Mobile Source Emissions in the Entire Chattanooga NAA 

### Jackson County NAA Portion 0.145 <1%
Chattanooga NAA 264.97 As the table above demonstrates, direct PM 2.5 emissions from on-road mobile sources in the Jackson County portion of the nonattainment area are less than 1% of the total direct PM 2.5 emissions from on-road mobiles sources in the entire Chattanooga NAA.

10.2.2 The current state of the air quality in Jackson County. The small portion of Jackson County, Alabama, was included in the Chattanooga PM 2.5 nonattainment area due to the fact that a power plant is located in that area and it was thought by EPA to contribute to the PM 2.5 problem in Chattanooga. There are no PM 2.5 monitors located in Jackson County. Monitors in Alabama near Jackson County have monitored values below the annual PM 2.5 NAAQS. Other counties surrounding the county are either in attainment or unclassifiable.

10.2.3 The absence of SIP motor vehicle controls for the area. There are no SIP motor vehicle controls for Jackson County.

10.2.4 Historical trends and future projections of the growth of motor vehicle emissions. The “Chattanooga Non-Attainment Area Year 2030 Conformity Determination Report for Particulate Matter (PM 2.5 )” was used to obtain past and future projections of the growth in direct PM 2.5 emissions from on-road mobile sources. As demonstrated in the table below, future emissions of direct PM 2.5 are expected to decrease. Table 10.2.4-1 Historical and Future Projections of PM 2.5 emissions from On-Road Mobile Sources in Jackson County


### 2002 0.145 2010 0.072 2020 0.041 2030 0.039

Each of the factors set forth in 40 CFR 93.109(k) were reviewed for the transportation-related PM 2.5 precursor pollutants NO X , SO X , and direct PM 2.5 . These reviews support the conclusion that mobile source emissions of NO X , SO X , and direct PM 2.5 in the Jackson County portion of the Chattanooga annual PM 2.5 nonattainment area are insignificant under the transportation conformity rule for the annual PM 2.5 NAAQS.

22

## 11.0 Summary and Conclusion

This section summarizes and concludes the results of the modeled attainment test referenced in this SIP, which covers the Jackson County, AL, portion of the Chattanooga annual PM 2.5 nonattainment area. EPA designated the Chattanooga area as nonattainment for the PM 2.5 NAAQS on January 5, 2005, and confirmed the designation on April 5, 2005. The Chattanooga PM 2.5 nonattainment area is made up of Catoosa and Walker Counties in Georgia, Hamilton County in Tennessee, and the portion of Jackson County in Alabama that is described as U.S. Census 2000 block group identifier 01–071-9503–1. While there are currently no monitors in Jackson County, AL, the observed PM 2.5 design value at three of the four nonattainment area monitors in TN and GA violated the annual standard from 2001- 2003, as shown in Table 11-1 below.

Table 11-1 2001 – 2003 PM 2.5 Design Values for Chattanooga Nonattainment Area Monitors



### Site name Monitor ID PM 2.5 

### Design Value
( μ g/m 3 

### ) PM 2.5 

### Standard
( μ g/m 3 

### ) Siskin Drive/UTC, Tennessee 470654002 15.2 15.0

Maxwell Road/East Ridge, Tennessee 470650031 16.1 15.0 Soddy-Daisy High School, Tennessee 470651011 14.1 15.0 Rossville-Maple St., Georgia 132950002 15.5 15.0

Speciated monitoring data from the Rossville -Maple St. site in Georgia and the Siskin Drive/UTC site in Tennessee have shown that the most significant components of PM 2.5 are sulfates and organic carbon. Sulfates are formed primarily from sulfur dioxide emissions from coal-fired electric generating units (EGUs), including EGUs located inside the nonattainment area and EGUs located outside the nonattainment area boundary. Control measures that may be credited in the SIP toward attainment are those that have been or will be implemented after 2002 but before 2009 (the modeled attainment year). Because of the large contribution of sulfates to the ambient PM 2.5 problem in the nonattainment area, the most important measures for achieving attainment are those that reduce SO 2 emissions from coal-fired EGUs. Georgia’s Multipollutant Rule (391-3-1-.02 (2) (sss)), enacted in 2007, is expected to achieve most of the needed reductions by reducing SO 2 emissions from EGUs. Other modeled state and federal control measures such as CAIR, as well as unmodeled measures, will contribute to PM 2.5 reduction to a smaller extent.
Models were used to demonstrate attainment of the PM 2.5 standard and the modeling was performed per EPA guidance. The modeling was performed in conjunction with the regional haze modeling being done by VISTAS and the PM 2.5 and ozone modeling being done by ASIP. The models used were as follows: • Meteorology: MM5
• Emissions: SMOKE • Air Quality: CMAQ

2324 An emissions inventory for the modeling was developed for the baseline year 2002 and projected to 2009. The pollutants inventoried include VOC, NO X , PM 2.5 , coarse particulate (PM 10 ), NH 3 , and SO 2 . The projection to 2009 accounted for control measures expected to be implemented. The CMAQ modeling performance was measured by accepted methods. Overall, it is believed that the model predictions can be used to form the scientific foundation for proposed control options because its performance is well within the limits of acceptable performance criteria established in the Attainment Modeling Guidance. To demonstrate attainment, the models were used to perform the SMAT test at both of the federal reference monitor sites. The SMAT test projects future concentrations of individual PM species and then sums the results to project total PM 2.5 . The 2009-modeled PM 2.5 design values are provided in Table 11-2. Since each of the modeled design values is less than 15.0 μ g/m 3

, modeled attainment is demonstrated.

Table 11-2 PM 2.5 2009 Future (Modeled) Design Values



### Federal Reference Monitor Monitor ID 2009 Annual Design Value (DVF) ( μ g/m 3 

### ) PM 2.5 

### Standard
( μ g/m 3 

### )

Siskin Drive/UTC, Tennessee 470654002 13.6 15.0
Maxwell Road/East Ridge, Tennessee 470650031 14.4 15.0
Soddy-Daisy High School, Tennessee 470651011 12.3 15.0
Rossville-Maple St., Georgia 132950002 13.9 15.0

In conclusion, this SIP, which covers the Jackson County, AL, portion of the Chattanooga annual PM 2.5 nonattainment area, is in accordance with regulatory requirements and guidance provided by EPA. It provides a comprehensive technical analysis that demonstrates that the Chattanooga PM 2.5 nonattainment area will attain the annual PM 2.5 NAAQS beginning in 2009. This demonstration is based upon implementation of the control measures described previously in this narrative, and will demonstrate attainment at the FRM monitors located in the Chattanooga nonattainment area.