# Fine Particulate Matter (**PM 2.5** 

# ) **NAAQS**

**S tate**  **I mplementation**  **P lan** 

**For** 

## The Tennessee Portion of the **Chattanooga, Tennessee -**  **Georgia PM 2.5**  

## Nonattainm **ent Area**

Prepared b y: Chattanooga - Hamilton County Air Pollution Control Bureau 6125 Pres ervation Drive Chattanooga, Tennessee 37416 - 3638 September 28 , 2009Page i **TABLE OF CONTENTS** List of Tables ................................ ................................ ................................ ................................ iii List of Figures ................................ ................................ ................................ ................................ iv List of Appendices ................................ ................................ ................................ ........................... v Acknowledgements ................................ ................................ ................................ ........................ vi 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 1.3 Chattanooga, Tennessee - Georgia PM 2.5 Nonattainment Area ................................ ....... 3 1.4 State Implementation Plan Requirements for PM 2.5 Nonattainment Areas ................... 9 2.0 Attainment Modeling ................................ ................................ ................................ ............ 10 2.1 Emissions Inventory ................................ ................................ ................................ ..... 10 2.1.1 2002 Emis sions Inventory Development ................................ ........................... 11 2.1.2 Controls Applied ................................ ................................ ................................ 15 2.1.3 2009 Emissions Inventory Development ................................ ........................... 17 2.2 Model Selection ................................ ................................ ................................ ........... 2 2 2.2.1 Selection of Photochemical Grid Model ................................ ............................ 2 3 2.2.2 Selection of Meteorological Model ................................ ................................ ... 24 2.2.3 Selection of Emiss ions Processing S ystem ................................ ........................ 2 5 2.2.4 Selection of Modeling Year ................................ ................................ ............... 2 7 2.3 Modeling Domains ................................ ................................ ................................ ....... 2 8 2.4 Boundary

Conditions ................................ ................................ ................................ ... 3 2 2.5 Initial Conditions ................................ ................................ ................................ ......... 3 2 2.6 Model Performance Evaluation ................................ ................................ ................... 32 3.0 Attainment Demonstration ................................ ................................ ................................ .... 34 3.1 Speciated Modeled Attainment Test ................................ ................................ ............ 34 3.2 Attainment Test Results ................................ ................................ ............................... 35 3.3 Supplemental Analyses/Weight of Evidence ................................ ............................... 36Page ii 3.3 .1 Emissions Reductions Not Modeled ................................ ................................ .. 37 3.3.2 Status of Modeled Emissions Reductions ................................ .......................... 43 3.3.3 Status of Attainment for Surrounding Counties ................................ ................. 4 3 4.0 PM 2.5 RACT/RACM ................................ ................................ ................................ ............. 4 4 4.1 Permitted Stationary Sources ................................ ................................ ....................... 45 4.1.1 Local Regulations ................................ ................................ .............................. 46 4.1.2 Sensitivity

Modeling ................................ ................................ .......................... 4 7 4.2 G asoline Dispensing Facilities ................................ ................................ ..................... 49 4.3 On- Road Mobile Sources ................................ ................................ ............................. 4 9 4.4 Non- Road and Stationary Internal Combustion Engines ................................ ............. 49 4.5 Open Burning ................................ ................................ ................................ ............... 50 4. 6 Home Heating with Wood ................................ ................................ ........................... 50 5.0 Motor Vehicle Emissions Budgets ................................ ................................ ........................ 51 5.1 Transportation Conformity ................................ ................................ .......................... 51 5.2 Transportati on Budget for Hamilton County ................................ ............................... 51 5. 3 Pollutants to Be Considered ................................ ................................ ......................... 51 5.3.1 Sulfur Dioxide (SO 2 ) ................................ ................................ .......................... 51 5.3.2 Nitrogen Oxides (NO X) ................................ ................................ ...................... 51 5.3.3 Volatile Organic Compounds (VOCs ) ................................ ............................... 52 5.3.4 Ammonia ................................ ................................ ................................ ............ 52 5.3. 5 Road and Construction Dust ................................ ................................ .............. 52 6.0 Contingency

Measures ................................ ................................ ................................ .......... 53 7 .0 Reasonable Further Progress ................................ ................................ ................................ . 54Page iii **LIST OF TABLES** Table 1 - 1 Annual PM 2.5 Design Values ................................ ................................ ....................... 4 Table 1 - 2 Components of Speciated PM 2.5 Monitored at the Siskin Drive/UTC Site ................. 6 Table 2 - 1 Summary

Emissions Inventory

for 2002 for Hamilton County, Tennessee .............. 12 Table 2 - 2 Summary

Emissions Inventory

for 2002 for Catoosa County, Georgia .................... 12 Table 2 - 3 Summary

Emissions Inventory

for 2002 for Walker County, Georgia ..................... 13 Table 2 - 4 Summary

Emissions Inventory

for 2002 for Jackson County, Alabama ................... 13 Table 2 - 5 PM 2.5 Emissions for 2002 by Emission Source Category ................................ .......... 14 Table 2 - 6 Sulfur Dioxide (SO 2 ) Emissions for 2002 by Emission Source Category ................. 14 Tabl e 2 - 7 Nitrogen Oxides (NO X) Emissions for 2002 by Emission Source Category ............. 14 Table 2 - 8 Ammonia Emissions for 2002 by Emission Source Category ................................ ... 15 Table 2 - 9 Summary

Emissions Inventory

for 200 9 for Hamilton County, Tennessee .............. 1 9 Table 2 - 10 Summary

Emissions Inventory

for 200 9 for Catoosa County, Georgia .................... 19 Table 2 - 11 Summary

Emissions Inventory

for 200 9 for Walker County, Georgia ..................... 20 Table 2 - 12 Summary

Emissions Inventory

for 200 9 for Jackson County, Alabama ................... 20 Table 2 - 13 PM 2.5 Emissions for 200 9 by Emission S ource Category ................................ .......... 2 1 Table 2 - 14 Sulfur Dioxide (SO 2 ) Emissions for 2009 by Emission Source Category ................. 2 1 Table 2 - 15 Nitrogen Oxides (NO X) Emissions for 2009 by Emission Source Category ............. 21 Table 2 - 16 Ammonia Emissions for 2009 by Emission Source Category ................................ ... 2 2 Tabl e 2 - 17 Vertical Layer Definition for MM5 and CMAQ ................................ ....................... 3 1 Table 2 - 18 MFE and MFB for the Siskin Drive/UTC FRM (470654002) ................................ .. 3 3 Table 3 - 1 2009 Quarterl y M ean and Annual PM 2.5 Design Values ................................ ........... 3 6 Table 3 - 2 2009 Modeled Species and PM 2.5 Annual Design Values ................................ ......... 3 6 Table 3 - 3 Surrounding Area 2009 Modeled Annual PM 2.5 Design Values ............................... 4 3 Table 4 - 1 Maximum PM 2.5 Concentration Reductions from Sensitivity Modeling ................... 4 8Page iv **LIST OF FIGURES** Figure 1 - 1 Locations of Federal Reference Monitors in the Chattanooga, Tennessee Georgia PM 2.5 Nonattainment Area ................................ ................................ .............. 5 Figure 1 - 2 Continuous PM2.5 Monitor Frontal Passage Trace ................................ ....................... 8 Figure 2 - 1 MM5 Horizontal Domain (Blue) with Nested CMAQ 36 -km Domain ..................... 2 9 Figure 2 - 2 ASIP/VISTAS Region 12 -km Grid ................................ ................................ ............ 30 Figure 3 - 1 Hamilton County Emissions of PM 2.5 ................................ ................................ ......... 3 9 Figure 3 - 2 Hamilton County Emissions of PM 10 ................................ ................................ ......... 3 9 Figure 3 - 3 Hamilton County Emissions of Sulfur Dioxide (SO 2 ) ................................ ................ 40 Figure 3 - 4 Hamilton County Emissions of Nitrogen Oxides (NO X) ................................ ............ 40 Figure 3 - 5 Hamilton County Emissions of Toluene ................................ ................................ ..... 41 Figure 3 - 6 Hamilton County Emissions of Xylenes ................................ ................................ ..... 4 1 Figure 3 - 7 Hamilton County Emissions of Ammonia ................................ ................................ .. 4 2Page v **LIST OF APPENDICES**  Appendix 1 PM 2.5 Conceptual Description Appendix 2 Draft Documentation of the Base G2 and Best & Final 2002 Base Year, 2009 and

2018 Emission Inventories for VI STAS Appendix 3 Methodology f or Augmenting State/Local/Tribal 1999 Point Source Emissions Inventories with PM 10 and PM 2.5 Emissions for the 1999 National Emissions Inventory Appendix 4 VI STAS/ASIP Technical Support Documents Appendix 5 Modeling Protocol for Association for Southeastern Integrated Planning (ASIP) Appendix 6 Application of GEOS CHEM for 2002 Boundary C onditions for CMAQ Modeling of the VISTAS Region Appendix 7 Local Area Modeling Performance Appendix 8 Hamilton County SMAT Process Appendix 9 Letter from Bowater Newsprint

– Calhoun Operations Appendix 10 Chattanooga - Hamilton County Air Pollution Control Industrial Point Source Emissions Appendix 11 EPA NEI PM 2.5 Document Appendix 12 RACT Industrial Point Source Review Appendix 13 House Heating Fuel

– 2000 U.S. Census Appendix 14 Planning Assumptions for Development of 2009 CHCNGA TPO TransCAD

Model 2009 Emissions Results Appendix 15 NO X Insignificance DemonstrationPage vi **ACKNOWLEDGEMENTS : VISTAS**  **CONTRACTORS VISTAS Technical Coordinator**  , Pat Brewer, NO X Insignificance Evaluation **Air Resource Specialists** : Monitoring Data Analysis **Alpine Geophysics** : Emissions AND Air Quality Modeling, Technical Advisor for Emissions Inventory **Atmospheric Research and Analysis, Inc** .: Operation of continuous monitors - Millbrook, NC **Baron Applied Meteorology** : Meteorological Modeling **Desert Research Institute** : Carbon Source Attribution including sample filter preparation, sample anal ys is using Gas Chromatography and Mass Spectrometry, source attribution using Chemical Mass Balance analys es and Positive Matrix Factorization **Earth Tech, Inc** : BART Modeling, CALPUFF Training **ENVIRON** : Emissions and Air Quality Modeling **Georgia Institute of Technology** : Emissions and Air Quality modeling sensitivities **Harvard University** : GE OS - Chem global model **ICF Consulting** : Integrated Planning Model for future electric utility generation **MACTEC** : 2002, 2009, and 2018 Emissions Inventory and Projections, CALPUFF training **E.H. Pechan and Associates** : 2002 Mobile Inventory **Research Trian gle Institute**  : Chemical Analys is of Monitoring Samples **System Applications International** : Meteorological Characterization **Tennessee Valley Authority** : Operation of continuous monitors at Great Smoky Mountain National Park and preparation of final proj ect report and draft manuscript **TRC, Inc** : BART Modeling **University of California, Riverside** : Emissions and Air Quality Modeling **Woods Hole** : Analysis of Carbon 14 isotope in carbon samples as part of carbon source attribution projectC - HCAPCB - 1 - PM 2.5 SIP **EXECUTIVE SUMMA RY**  On January

5 , 2005, the United States Environmental Protection Agency (EPA) published the fine particulate matter (PM 2.5 ) nonattainment designation for the Chattanooga, Tennessee Georgia area. This area consists of Hamilton County in Tennessee, Catoos a 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. Between 2001 and 2003, air quality monitoring within this area indicated that the annual average PM 2 .5 concentrations (design values) exce eded the 15.0 μg/m 3 National Ambient Air Quality S tandard (NAAQS). The Chattanooga - Hamilton County Air Pollution Control Bureau, the Tennessee Division of Air Pollution Control, the Georgia Air Protection Branch, and the Alabama Department of Environmental Management have collaborated to develop a PM 2.5 NAAQS State Implementation Plan (SIP) for each jurisdiction . This document contains the SIP for the Hamilton County, Tennessee portion of the nonattainment area. Air quality

modeling conducted for Hamilton County b y the Association for Southeastern Integrated Planning (ASIP) indicates that the nonattainment area will attain the annual NAAQS 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. Hamilton County expects to 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. **2009 Modeled Annual PM 2.5**  **Design Values**  Federal Reference Monitor PM 2.5 Design Value ( μg/m 3 ) Siskin Drive/UTC (470654002) 13.6 Maxwell Road/East Ridge (470650031) 14.4 Soddy- Daisy

High School (470651011) 12.3 Walker County, Georgia (132950002) 13.9 As required by

the EPA Clean Air Fine Particle Implementation Rule , sources of PM 2.5 and its precursors within Hamilton County were evaluated to verify that they

were meeting at least reasonabl y available control measures (RACM) levels of emission controls. This evaluation and the results of sensitivity

modeling that was performed indicate that no additional reductions are available from local sources that would result in advancement of the attainment date to earlier than 2009.C - HCAPCB - 2 - PM 2.5 SIP

**1.0 INTRODUCTION 1.1**  **F ine**  **P articulate**  **M atter**  **(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 (μm) 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. PM2.5 exposure adversely affects human health, especially respiratory

and cardiovascular systems. Individuals particularly sensitive to PM2.5 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 l iquid. P M 2.5 can include material produced by

c ombustion, photochemical reactions, and can contain salt from sea spray and soil like particles. P articles are distinguish ed 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, hydroxylradical, 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 (usuall y 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, alumin um, 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 power plants, indu strial 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.C - HCAPCB - 3 - PM 2.5 SIP

A variety of meteorolo gical and geographic factors influence s the concentration levels of fine p articles, 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 N ational Ambient Air Quality S tandards (NAAQS) at any time of the ye ar, the United States Environmental Protection Agency (EPA) mandates the ye ar round monitoring of the pollutant throughout the country (40 CFR 58 , App. D). **1.2 PM** **2.5 National Ambient Air Quality Standard**  In July 1 997, the EPA established both annual and 24 -hour fine particulate primary (healthbased) and secondary

NAAQS for annual and 24 -hour fine particulate. The secondary P M 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 - ye ar average of a monitoring site 's annual 98th percentile value is 35 micrograms per cubic meter ( μg/m 3 ) or less. The annual standard is met when the 3 - ye ar average of a monitoring site's annual mean concentration is 15.0 μg/m 3 or less. The 3 - ye ar averages at each monitoring site (of annual means or 98 th percentiles) are called design values. The des ign 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 f ormally 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 (S ubpart 1) have five years from designation to attain the standard. **1.3 Chattanooga, Tennessee** **- Georgia PM** **2.5 Nonattainment Area**  The EPA does not plan to designate geographic areas as attainment or nonattainment for the 2006 24 -hour PM 2.5 standard until December 2008 or later. Therefore, this State Implementation Plan (S IP ) does not address attainment and/or nonattainment issues with the 24 -hour standard. 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. Although Jackson County is not contiguous to the rest of the nonattainment area, a coal - fired power plant located in this census tract is a major contributor to the PM 2.5 problem. The effective date of the nonattainment designation was April 5, 2005, and was based on air quality monitoring for the ye ars 2001, 2002, and 2003. Four PM 2.5 federal reference monitors are located in the nonattainment area – three in Hamilton County and one in Walker County . F ederal reference monitors (FRM) collect samples that are used to determine if an area is in attainment with the PM 2.5 NAAQS. Al ist of the monitors andC - HCAPCB - 4 - PM 2.5 SIP

associated design values is provided below in Table 1 - 1 . The FRM located at Soddy- Dais y High School is at the most rural site of the three Hamilton County F RMs and has always shown attainment. The other three monitors show exceedances of the annual standard for the 2001 - 2003 averaging period, which is the period the EPA used in the designation of the nonattainment area. The locations of the four FRMs in the nonattainment area are shown in Figure 1 - 1 , which follows. **Table 1 -**  **1 .**  **Annual PM** **2.5 Design Values**  Federal Reference Monitor PM 2.5 Design Value ( μg/m 3 ) 2001 - 2003* 2002 - 2004 2003 - 2005 2004 - 2006 Siskin Drive/UTC (470654002) 15.2 14.7 15.0 15.1 Maxwell Road/East Ridge (470650031) 16.1 15.7 16.1 15.5 Soddy- Daisy

High School (470651011) 14.1 13.8 13.8 13.5 Walker County, Georgia (132950002) 15.5 1 5.2 15.8 15.2 * Averaging period used by the EPA in the nonattainment area designationC - HCAPCB - 5 - PM 2.5 SIP **Figure 1**  **- 1**  **. Locations of Federal Reference Monitors in the**  **Chattanooga, Tennessee -**  **Georgia PM** **2.5 Nonattainment Area** C - HCAPCB - 6 - PM 2.5 SIP

As mentioned in Section 1.1 of this document, PM 2 .5 is composed of many species from varying sources. In order to fully understand the nature of the problem in Hamilton County and to ascertain an appropriate response, the PM 2.5 components must be determined. F ine particulate speciation monitors are col located with the FRM s at the Siskin Drive/UTC and Walker County, Georgia , sites. The speciation monitor located at the Siskin Drive/UTC site is part of the EPA Speciation Trends Network (STN) . S peciation monitors provide concentrations of total PM 2.5 , ammonium, potassium, sodium, nitrates, sulfates, elemental carbon, organic carbon, and fortyseven metals. M ajor components of PM2.5 from the Siskin Drive/UTC speciation monitor are shown below in Table 1 - 2. **Table 1**  **- 2. Components of Speciated PM** **2.5 Monito**  **red at the**  **Siskin Drive/UTC S**  **ite**

Year Concentration ( μg/m 3 )

**Total PM** **2.5** Organic

Carbon Sulfates Nitrates Ammonium Elemental Carbon 2002 **16.90** 5.34 4.99 0.95 1.65 0.66 2003 **17.55** 5.46 5.11 1.26 1.85 0.75 2004 **15.26** 4.40 4.85 1.18 1.63 0.65 2005 **17.84** 4.94 5.39 1.10 1.88 0.68 Air emissions from both regional and local sources contribute to the nonattainment problem in Hamilton County. The two major components of the speciated total PM 2.5 are organic carbon and sulfates. Organic carbon makes up approximately thirty percent of the speciated PM 2.5 . The organic carbon is composed of both primary P M 2.5 , such as direct emissions from engines, and secondary P M 2.5 that result s from atmospheric reactions of precursors . The organic carbon from diesel engine s includes unburned fuel and engine lubrication oil. M any diesel engines vent crankcase emissions to the atmosphere. Two cycle engines have lubricating oil mixed with their fuel resulting in emissions of unburned lubricating oil. Aromatic compounds, bio genic compounds, and organic products of incomplete combustion are examples of secondary P M 2.5 precursors. Aromatic compounds include toluene, xylenes, and trimethylbenzenes that are emitted from industrial sources and form secondary organic aerosols . B i ogenic compounds include terpenes and sesquiterpenes that are emitted by trees and other vegetation. As shown by the EPA’s Biogenic Emission Inventory S ystem (BE IS 3.09 ) model, organic carbon from biogenic precursors accounts for a significant portion of the organic carbon in the nonattainment area between March and December. F orest fires, prescribed burning, and home heating with wood are all sources of organic products of incomplete combustion . Prescribed burns in Hamilton County are normally c onducted in the spring and fall. Significant home heating in this area is performed for five months of the year. Sulfates are formed from atmospheric reactions of SO 2 and also make up approximately thirty percent of the total PM 2.5 at the monitor. S ome of these reactions also involve ammonia. The primary sources of SO 2 in Hamilton County include industrial combustion equipment and mobile sources. M ost industrial sources in Hamilton County u se natural gas as the primary f uel. S inceC - HCAPCB - 7 - PM 2.5 SIP

natural gas contains a negligible amount of sulfur, minimal SO 2 emissions result from its combustion. When natural gas is curtailed, some industrial sources use fuel oil as a backup. Number 2 fuel oil ty

pically c ontains no more than 0.2 % sulfur, but Number 6 fuel oil could contain u p to two percent sulfur. There is also some industrial use of coal as a fuel in Hamilton County . The combustion of Number 2 and Number 6 fuel oils and coal result s in increasingl y higher levels of SO 2 emissions than those from natural gas . H owever, the SO 2 emissions from combined industrial and mobile sources within Hamilton County are significantly

less than those from regional coal - fired electric utilities, none of which are located in the county . In 2002, the combined SO 2 emissions from all sources within Hamilton County w ere less than ten percent of the SO 2 emissions from the TVA Widows Creek Fossil Plant in Jackson County, Alabama, which is the closest of four regional coal - fired power plants located within 75 miles of the county . Nitrates, which make up less than ten percent of the speciated PM 2.5 , are formed from atmospheric reactions of NO X with ammonia. C ombustion processes are the primary s ource of NO X emissions both inside and outside the county . These processes include on- road mobile source s; non-road mobile sources; space heating; industrial processes; forest fires; and burning of vegetation. Regional coal - fired electric generation plants located outside the county also contribute NO X emissions. The ammonia that reacts with NO X and SO 2 to form ammonium nitrate and ammonium sulfate, respectivel y, is produced primarily f rom automobile catal ysts, sewage treatment, and agriculture sources both locall y and regionally . E lemental carbon, or soot, makes up a small portion of the total PM 2.5 and i s usually f ormed by incomplete combustion of fuels such as gasoline or diesel fuel. Once PM 2.5 is emitted to or formed in the atmosphere, it may remain suspended for weeks, but is eventually removed by

e ither dry

or wet deposition. The concentration in the air is dependent on wind and weather conditions. If there is no wind, the PM 2.5 remains in the vicinity, and the concentration continues to rise until reaching a state of equilibrium in which the rate of deposition is equal to the rate of development o f fine particulate. When weather front s pass through the Hamilton County area, monitored increase s in PM 2.5 are observed followed by rapid decreases with the frontal passage. One example of this phenomenon is charted in Figure 1 - 2 , which follows . The profile is for a day d uring which the National Oceanic and Atmospheric Administration weather records for February 1 3, 2007 , indicate the passage of a front between 10:53 AM and 11:53 AM. The characteristic rapid drop in PM 2.5 is shown beginning at that time by the green line labeled RIV, which is the output of a continuous PM 2.5 monitor located at the Siskin Drive/UTC site.C - HCAPCB - 8 - PM 2.5 SIP **Figure 1**  **- 2**  **. Continuous PM 2.5**  **Monitor Frontal Passage Trace**  A study p erformed for the Visibility Improvement State and Tribal Assoc iation of the Southeast (VI STAS ) , Characterization of Meteorology and its Relationship to Fine Particulate Mass and Visibility in the VISTAS Region , was completed on December 8, 2006. The anal ys is was conducted over the VI STAS sites and included specific information for Hamilton County . The study showed that high PM 2.5 concentrations in the area are associated with the following:

 Moderate temperatures  Low surface or aloft wind speeds  South surface winds  East aloft winds  Stable atmospheric conditions  Very high PM 2.5 concentrations on the previous day A local surface wind study u sing Chattanooga/Lovell Field data conducted by the Southern Regional Climate Center showed calm winds 26.27 % of the time with a mean wind of 6.28 knots. The most common direction for surface winds was from the south. This study used wind data from 1984 through 1992. Appendix 1 provides further conceptual information on ambient PM 2.5 concentrations in Hamilton County.C - HCAPCB - 9 - PM 2.5 SIP

**1.4 State Implementation Plan R** **equirements for PM** **2.5 N**  **onatta inment**  **A reas**  The April 5, 2007 , EPA Clean Air Fine Particle Implementation Rule (PM 2.5 Implementation Rule) requires that a State Implementation Plan ( SIP ) be developed and submitted to the EPA no later than three ye ars from the date of nonattainment desi gnation. A SIP documents how and when an area will be brought into attainment with a national air quality standard. There are several required elements in the PM2.5 SIP. These include an emissions inventory, a modeled attainment demonstration, an anal ys is of reasonably available control technologies (RACT) and reasonabl y available control measures (RACM), and the adoption of the RACT/RACM levels of emission controls if the addition of those controls could move up the attainment date b y a ye ar. The PM 2.5 Implementation Rule establishes a hierarchy of precursor pollutants for PM2.5 : SO 2 is always considered a precursor, NO X is presumptively aprecursor, and VOCs and ammonia are presumed not to be precursors. The rule allows States to exempt NO X by demonstrating that NO X emissions are not a significant contributor to an area’s PM 2.5 nonattainment problem and that the area is not a source of a PM 2.5 transport problem. The rule also requires that contingency measures be included in the SIP for areas design ated nonattainment for PM 2.5 . The contingency measures are to be implemented in the event the nonattainment area does not meet attainment by the date specified in the SIP.C - HCAPCB - 10 - PM 2.5 SIP

**2 .0 ATTAINMENT**  **MODELING** In 2001, the southeastern states formed the Visibility Improvement State and Tribal Association of the Southeast (VI STAS ) 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. As required by

the EPA’s Apri l 2007 Guidance on the Use of Models and Other Analyses for Demonstrating Attainment Goals for Ozone, PM 2.5, and Regional H

aze (Attainment Modeling Guidance), modeling data files are archived and will be maintained by Tennessee Division of Air Pollution Control at 615 - 532 - 0554. **2 .1 Emission**  **s I**  **nventory** An emissions inventory

i s a comprehensive quantification of all emissions in a region that cause or contribute to a nonattainment area failing to meet an air standard. In modeled attainment demonstrations, the emission inventory i s developed for a past ye ar so that emissions can be quantified as accuratel y as possible. F or the annual PM 2.5 standard, the EPA provided guidance for selecting the past (base) ye ar. The base ye ar was recommended to be 2002 as p er a November 18, 2002, letter titled “2002 Base Year Emission Inventory SIP Planning: 8 -hr Ozone, PM 2.5 , and Regional Haze Programs” signed by Lydia N. Wegman. B oth National Emission Inventory (NE I) data and monitored PM 2.5 values were available for the 2002 base year. VI STAS developed a regional emissions inventory, which included input from each member state air agency

as well as input from the local agencies in Davidson County, TN, Hamilton County, TN, Shelby

C ounty, TN, Knox County, TN, Jefferson County, AL , Jefferson County, KY, Buncombe County, NC, Fors yth County, NC and Mecklenburg County, NC. Adetailed discussion of the inventory development is provided in the Documentation of the Base G 2002 Base Year, 2009 and 2018 Emission Inventories for VISTAS located in Appendix 2 . There are five different emission inventory s ource classifications: stationary p oint sources, area sources (including stationary area sources), off

- road and on-road mobile sources, and biogenic sources. In Hamilton County, stationary p oint sources have a fixed location and require permits to operate unless they

h ave been defined as “insignificant activities” in the local air pollution control regulations. Industrial sources make up the bulk of stationary point sources in the county, and their emissions are inventoried annually . E lectric generating units (EGUs) are the single largest contributor to PM 2.5 from point source emissions in the region. No EGUs are located in Hamilton County . Area sources in Hamilton County include stationary

area sources, fires, animal husbandry, and paved and unpaved roads. S tationary area sources are those sources whose individual emissionsC - HCAPCB - 11 - PM 2.5 SIP

are relativel y small, but due to the large number of these sources, the collective emissions from the source category

c ould be significant. F or example, dry c leaners and service stations are stationary area sources found in Hamilton County . Non-road (or off

-road) mobile sources are equipment that move but do not use the roadways, such as construction equipment , aircraft, railroad locomotives, lawn and garden equipment, etc. On-road mobile sources are automobiles, buses, trucks, and motorcycles that use the roadway system. Emissions from on-road sources are estimated by v ehicle ty

pe and road ty

pe. Biogenic sources are natural sources like trees, crops, grasses, and the natural decay of plants. Emissions from non-road, on -road, and biogenic sources are estimated county wide. **2 .1.1 2002 Emissions Inventory Development**  The starting point of the 2002 emissions inventory was EPA’s 1999 NEI . Several agencies provided more recent inventories. S elected large ammonia sources were updated, 2002 continuous emissions monitoring based SO 2 and NO X emissions were added for electric utilities, emissions of PM2.5 and PM 10 (particulate matter less than or equal to 10 μm in diameter) were added if not in the submittal, and quality assurance/quality

control checks were performed. The “Base G” emissions inventory was released in August 2006 and, where appropriate, incorporate d 2002 NEI submittals (including Hamilton County ’s NEI submittal). H owever it was still necessary, in finalizing the inventory, to augment stationary p oint source emissions in accordance with Appendix C of EPA’s Documentation of the Final 1999 National Em issions Inventory (V

ersion 3) for Criteria Polluta nts and Ammonia

– Point Sources , which can be found in Appendix 3. For EGUs, normalization factors were developed for producing a 2002 ty pical ye ar inventory . The normalization factor is derived by averaging the 2000 to 2004 heat input and then dividing the result by the actual 2002 heat input. If the unit did not operate all five ye ars, then the average heat input was only c alculated for the ye ars it operated. The final version of the emissions inventory is Base G4, which was used for the modeled attainment demonstration. Stationary

area source emissions, which were submitted to comply with the Consolidated Emissions Reporting Rule (CERR), were obtained from the EPA. The emissions were evaluated and mi ssing data added. A“ty pical” fire ye ar inventory was developed covering wildfires, prescribed burning, agricultural fires, and land clearing fires. Ammonia emissions from livestock and fertilizers were calculated using Version 3.6 of the Carnegie Mellon University ammonia model. P aved and unpaved road emissions were estimated using EPA approved methodology . Most non-road emissions were estimated using the EPA’s NONROAD2005c model. Aircraft engines, railroad locomotives, and commercial marine emissions were not included in the NONROAD model and were estimated separately . These “other non- road” emissions were based on emissions estimates developed for the EPA’s 1999 NEI Version 2. Mobile6.2 was used to estimate emissions from on-road mobile sources. B iogenic emissions were estimated using the BEIS3 .09 model . Table s 2 - 1 through 2 - 8 summarize the emissions inventory u sed in theC - HCAPCB - 12 - PM 2.5 SIP

2002 model. This data reflects best data available with some data from modeling, some calculated and some CEM data. **Table 2**  **- 1**  **. Summary Emissions Inventory for 2002 for**  **Hamilton County, Tennessee**

**Table 2 -** **2 .**  **Summary Emissions Inventory for 2002 for Catoosa County, Georgia** C - HCAPCB - 13 - PM 2.5 SIP

**Table 2 -** **3 .**  **Summary Emissions Inventory for 2002 for Walker County, Georgia** 

**Table 2 -** **4 .**  **Summar y Emissions Inventory for 2002 for**  **Jackson County, Alabama**C - HCAPCB - 14 - PM 2.5 SIP **Table 2 -**  **5 . PM** **2.5 Emissions for 2002 by Emission Source Category**  County PM 2.5 Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 567 1,000 292 183 **2,042** Catoosa, GA 0 675 37 3 7 **750** Walker, GA 2 920 19 29 **970** Jackson, AL 963 1,209 88 41 **2,301 Total**  **1,532 3,804**  **437 291**  **6,064 Table 2**  **- 6**  **. Sulfur Dioxide (SO 2**  **) Emissions for 2002 by Emission Source Category** County Sulfur Dioxide (SO 2 ) Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 1,721 507 539 461 **3,228** Catoosa, GA 0 272 51 92 **415** Walker, GA 203 761 21 71 **1,056** Jackson, AL 45,357 576 167 99 **46,199 Total**  **47,281 2,115**  **778 723**  **50,898 Table 2**  **- 7**  **. Nitrogen Oxides (NO X** **) Emissions for 2002 by Emission Source Category**  County Nitrogen Oxides (NO X) Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 2,856 639 6,428 11,610 **21,532** Catoosa, GA 0 162 671 2,377 **3,211** Walker, GA 46 384 269 1,699 **2,398** Jackson, AL 26,862 310 1,418 2,195 **30,785 Total**  **29,763 1,495**  **8,787 17,881**  **57,926**C - HCAPCB - 15 - PM 2.5 SIP **Table 2 -**  **8 . Ammonia Emissions for 2002 by Emission Source Category**  County Ammonia Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 17 172 2.1 357 **549** Catoosa, GA 0 468 0.2 74 **542** Walker, GA 0 763 0.3 56 **819** Jackson, AL 2 1,280 0.6 77 **1,361 Total**  **20 2,684**  **3.2 563**  **3,270 2**  **.1.2 C**  **ontrols Applied** Several control measures already in place or being implemented over the next few ye ars will reduce stationary

p oint, highway

mobile, and non-road mobile sourc es emissions. The Federal control measures that have impacts on air quality in Hamilton County w ere incorporated into the Base G4 emissions inventory and are discussed in the following sections . Tier 2 Vehicle Standards Federal Tier 2 vehicle standards will require all passenger vehicles in a manufacturer’s fleet, including light- duty

trucks and sport utility

v ehicles (SUVs), to meet an average standard of 0.07 grams of NO X per mile. Implementation began in 2004, and was to be completely phased in by 20 07. 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. F or these vehicles, the standards will be phased in be ginning in 2008, with full compliance in 2009. The new standards require vehicles to be seventy- seven percent to ninetyfive percent cleaner than those on the road today . The Tier 2 rule also reduced the sulfur content of gasoline to thirty

p arts per mil lion (ppm) starting in January o f 2006. M ost gasoline sold in Hamilton County

prior to January

2 006 had a sulfur content of about 300 ppm. Sulfur occurs naturally in gasoline, but interferes with the operation of catal ytic converters on vehicles resulting in higher NO X emissions. Lower- sulfur gasoline is necessary to achieve the Tier 2 vehicle emission standards. Heavy-Duty Diesel Highway Vehicles Standards New EPA standards designed to reduce NO X and volatile organic compound (VOC ) emissions from heavy- duty gasoline and diesel highway v ehicles began to take effect in 2004. As econd phase of standards and testing procedures, which began in 2007, will reduce particulate matter emissions from heavy- duty highway engines and will also reduce highway diesel fuel sulfur content to fifteen ppm since the sulfur damages the particulate filters that are required to meet the new standard. The total pro gram is expected to achieve a ninety percent reduction in particulateC - HCAPCB - 16 - PM 2.5 SIP

matter emissions and a ninety- five percent reduction in NO X emissions for these new engines using low- sulfur diesel fuel , compared to existing engines using higher- sulfur content diesel fuel . Large Non - road Diesel Engines Rule In May 2 004, the EPA promulgated new rules for large non -road diesel engines, such as those used in construction, agricultural, and industrial equipment, to be phased in between 2008 and 2014. The non-road diesel rules also reduce the allowable sulfur in non-road diesel fuel by over ninety-nine percent . Non-road diesel fue l currently averages 3,400 ppm sulfur. The rule limits non-road diesel sulfur content to 500 ppm in 2006 and 15 ppm in 2010. The combined engine and fuel rules would reduce NO X and particulate matter emissions from large non-road diesel engines by

over ninety

p ercent , compared to current engines using higher- sulfur content diesel fuel . Non - road Spark

-Ignition Engines and Recreational Engines Standard The new standard, effective in July 2003, regulates emissions of NO X , hydrocarbons, and carbon monoxide for groups of previously unregulated non-road engines. The new standard will appl y to all new engines sold in the United States and imported after these standards began and will apply to large spark- ignition engines (forklifts and airport ground service e quipment), recreational vehicles (off -highway motorcycles and all -terrain -vehicles), and recreational marine diesel engines. The regulation varies based upon the ty pe of engine or vehicle. The large spark- ignition engines contribute to ozone formation and ambient carbon monoxide and particulate matter levels in urban areas. Tier 1 of this standard was implemented in 2004 and Tier 2 started in 2007. Like the large spark- ignition, recreational vehicles contribute to ozone formation and ambient carbon mono xide and particulate matter levels. F or the model ye ar 2006 off -highway motorcycles and all -terrain-vehicles, the new exhaust emissions standard was phased- in by fifty percent and for model ye ars 2007 and late, by one hundred percent . Recreational marine diesel engines over thirty- seven kilowatts are used in yachts, cruisers, and other ty pes of pleasure craft. Recreational marine engines contribute to ozone formation and particulate matter levels, especiall y in marinas. D epending on the size of the engine, the standard began phasing - in in 2006. When all of the non-road spark- ignition engines and recreational engines standards are fully implemented, an overall seventy-two percent reduction in emissions of hydrocarbons, eighty percent reduction in NO X emi ssions, and fifty- six percent reduction in carbon monoxide emissions are expected by 2 020. These controls will help reduce ambient concentrations of ozone, carbon monoxide , and PM 2.5 . NO X SIP Call InO ctober 1998, the EPA made a finding of significant c ontribution of NO X emissions from certain states and published a rule that set ozone season NO X budgets for the purpose of reducing regional transport of ozone (63 FR 57356). This rule, referred to as the “NO X SIP Call , ” called for ozone season controls to be put on utility and industrial boilers, as well as internal combustion engines in twenty-two states in the eastern United States. ANO X emissions budgetC - HCAPCB - 17 - PM 2.5 SIP

was set for each state, and the states were required to develop rules that would allow the state to meet their budget. The emission budgets were to be met by the beginning of 2004 . The NO X SIP Call resulted in regional reductions pf PM 2.5 and PM 2.5 precursors that reduced PM 2.5 in this nonattainment area. Clean Air Interstate Rule On May 1 2, 2005 , the EPA promulgated the “Rule to Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program; Revisions to the NO X SIP Call,” referred to as CAIR. This rule established the requirement for States to adopt rules limiting NO X and SO 2 emissions and a model rule for the states to use in developing their rules. The purpose of the CAIR is to reduce interstate transport of precursors to fine particulate and ozone. The CAIR applies to certain large fossil - fuel fired boilers and turbine s that serve electricity generators . This rule provides annual state caps for NO X and SO 2 in two phases, with the Phase I caps for NO X and SO 2 starting in 2009 and 2010, respectively. Phase II caps become effective in 2015. The EPA is allowing the caps to be met through a cap and trade program if a state chooses to participate in the program. When fully implemented, the CAIR will reduce SO 2 emissions in the eastern United States by over seventy percent and NO X emi ssions by o ver sixty

p ercent from 2003 levels. Though the rule was remanded to EPA by the U.S. Court of Appeals for the District of Columbia, TVA is continuing to operate their controls set forth in the CAIR rule pending a new rule being developed. These controls have resulted in regional reductions of both nitrates and sulfates in the area. **2 .1.3**  **2009 E**  **missions I**  **nventory D**  **evelopment** A regional emissions inventory was developed for the 2009 modeling. Projections for EGUs, non- EGU point sources, area s ources, non- road, and on- road mobile sources were used to produce a 2009 emission inventory . Future EGU emissions were estimated using the EPA Integrated Planning Model, which is used to examine air pollution control policies for various pollutants for the entire electric power system throughout the contiguous United States. The general approach for future ye ar non - EGU point source emissions projections was to use growth and control data consistent with the data used in EPA’s Clean Air Interstate Rule analysis, and supplement these data with stakeholder input. The following activities were performed for nonEGU point sources.

 Obtained, reviewed, and applied the most current growth factors developed by EPA  Obtained, reviewed and applied any state - specific , or sector specific growth factors submitted by

stakeholders  Obtained and incorporated information on sources that shutdown after 2002 and set their emissions to zero in the projection inventoriesC - HCAPCB - 18 - PM 2.5 SIP

 Obtained, reviewed, and applied control assumptions for programs that are presently adopted and controls that have future compliance dates. S ince the modeling dealt with controls that are presently required to be operated and controls that will be operated in a future ye ar as the future year modeling was conducted for 2009 and 2018. For area source categories, except fires, VISTAS/ASIP generated future emissions were based on the 2002 inventory

year. Growth factors supplied by the states or the CAIR emission projections were applied to project the controlled emissions to the appropriate ye ar. In some cases, the EPA’s Economic Growth and Anal ys is System Version 5 growth factors were used if no growth factor was available from either the states or the CAIR growth factor files. F or fires, the “ty pical” year inventory

developed in 2002 was used. For source categories with emissions estimated using the EPA’s NONROAD model, the model growth assumptions were used to create the 2009 future ye ar inventory . The NONROAD model takes into consideration regulations affecting emissions from these categories. F or the commercial marine, railroad locomotives, and airport emissions, VI STAS calculated the future growth in emissions using detailed inventory data (both before and after controls) for 1996 and 2010, obtained from the CAIR Technical Support Document. When available, state - specific growth factors were used. MOBILE6.2, which takes into consideration regulations that affect emissions from this source category, was used to estimate emissions for on-road mobile source emissions in the 2009 inventory . The vehicle miles traveled (VMT) input from the MOBILE6.2 2002 base year inventory provided the basis for the initial 2009 VMT input. The 2009 VMT estimate assumed a linear growth rate for each state, county, and vehicle ty pe as derived from the VMT data assembled by

the EPA for their most recent heavy- duty diesel rulemaking. In the final 2009 VMT input estimate for MOBILE6.2, s everal states provided independent forecast data to either replace or augment the forecast data b ased on the heavy- duty diesel rule. Table s 2 - 9 through 2 - 16 summarize the emissions inventory that was used for the 2009 model.C - HCAPCB - 19 - PM 2.5 SIP

**Table 2**  **- 9**  **. Summary Emissions Inventory for 200**  **9 for**  **Hamilton County, Tennessee**

**Table 2**  **- 10**  **. Summary Emissions Inventory**  **for 200 9**  **for Catoosa County, Georgia** C - HCAPCB - 20 - PM 2.5 SIP

**Table 2**  **- 11**  **. Summary Emissions Inventory for 200**  **9 for**  **Walker County, Georgia**

**Table 2 -**  **12 .**  **Summary Emissions Inventory for 200 9**  **for Jackson County, Alabama** C - HCAPCB - 21 - PM 2.5 SIP **Table 2 -**  **13 . PM** **2.5 Emissions for 2009 by Emission**  **Source Category** County PM 2.5 Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 504 1,073 243 131 **1,951** Catoosa, GA 0 731 33 27 **792** Walker, GA 1 988 15 21 **1,025** Jackson, AL 1,156 1,252 70 30 **2,507 Total**  **1,661 4,044**  **360 209**  **6,274 Tabl**  **e 2 -**  **14 . Sulfur Dioxide (SO**  **2 ) Emissions for 2009 by Emission Source Category**  County Sulfur Dioxide (SO 2 ) Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 1,700 541 223 54 **2,517** Catoosa, GA 0 273 9 11 **292** Walker, GA 195 762 4 8 **969** Jackson, AL 46,578 532 79 12 **47,200 Total**  **48,473 2,107**  **314 85**  **50,978 Table 2**  **- 15**  **. Nitrogen Oxides (NO X** **) Emissions for 2009 by Emission Source Category** County Nitrogen Oxides (NO X) Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 2,949 64 5 5,602 7,514 **16,710** Catoosa, GA 0 169 584 1,621 **2,374** Walker, GA 46 398 200 1,194 **1,838** Jackson, AL 5,663 317 1,287 1,437 **8,704 Total**  **29,764 1,495**  **8,786 17,881**  **57,926**C - HCAPCB - 22 - PM 2.5 SIP **Table 2 -**  **16 . Ammonia Emissions for 2009 by Emission Source Category**  County Ammonia Emissions (tons)

Point Area Non-road On-road **Total** Hamilton, TN 17 173 2.4 415 **608** Catoosa, GA 0 521 0.3 87 **608** Walker, GA 0 844 0.3 66 **910** Jackson, AL 8 1,408 0.6 88 **1,504 Total**  **25 2,944**  **3.6 656**  **3,629 2**  **.2 Model Selection** To ensure that a mo deling study i s defensible, care must be taken in the selection of the models to be used. The models selected must be “scientifically a ppropriate” for the intended application and be “freel y accessible” to all stakeholders. S cientifically a ppropriate means that the models address important physical and chemical phenomena in sufficient detail, using peer- reviewed methods. Freel y accessible means that model formulations and coding are freel y available for review and that the models are available to stakeho lders, and their consultants, for execution and verification at no or low cost. The following models were selected b y AS IP for use in PM 2.5 modeling .  Air Quality

M odel: The EPA’s Models - 3/Community Multiscale Air Quality

( CMAQ) modeling system is a “ o ne - atmosphere” photochemical grid model capable of addressing ozone , particulate matter, visibility, and acid deposition at regional scale for periods up to one year.  Meteorological Model: The Penns ylvania State University /National Center for Atmospheric Re search Mesoscale Meteorological Model (MM5) is a nonhydrostatic, prognostic meteorological model routinely u sed for urban- scale and regional - scale photochemical, fine particulate matter, and regional haze regulatory modeling studies.  Emissions Model: The Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system is an emissions modeling system that generates hourl y gridded speciated emission inputs of mobile, non-road mobile, area, point, fire and biogenic emission sources for photochemical grid model s. The following sections outline the criteria for selecting a modeling system that is both defensible and capable of meeting the study's goals. These criteria were used in selecting the modeling system used for this modeling attainment demonstration.C - HCAPCB - 23 - PM 2.5 SIP

**2 .2.1 Selection of Photochemical Grid Model**  Criteria For a photochemical grid model to qualify as a candidate for use in a SIP, a State needs to show that it meets the following general criteria for a NAAQS attainment demonstration .  The model has received a scientific peer review .  The model can be demonstrated applicable to the problem on a theoretical basis .  Data bases needed to perform the analys is are available and adequate .  Available past appropriate performance evaluations have shown the model is not biased toward underestimates or overestimates .  A protocol on methods and procedures to be followed has been established .  The developer of the model must be willing to make the source code available to users for free or for a reasonable cost, and the mode l cannot otherwise be proprietary . Overview of CMAQ The photochemical model selected for this study was CMAQ Version 4.5. During the course of the modeling, VI STAS updated the secondary organic aerosol module in CMAQ to include important processes missing in the standard CMAQ model. S econdary o rganic aerosol module improvements are detailed in Section 1.3.3.3.1 of the Technical Support Document for VISTAS Emissions and Air Quality Modeling to Support Fine Particulate State Implementation Plans (Technical Support Document for VI STAS) , which can be found in Appendix 4. For more than a decade, the EPA has been developing the Models - 3 CMAQ modeling system with the overarching aim of producing a “One -Atmosphere” air quality modeling system capable of address ing ozone, fine particulate matter, visibility and acid deposition within a common platform. The original justification for the Models - 3 development emerged from the challenges posed by the 1990 CAAA and the EPA’s desire to develop an advanced modeling framework for “holistic” environmental modeling utilizing state - of - science representations of atmospheric processes in a high performance computing environment. The EPA completed the initial stage of development with Models - 3 and released the CMAQ model in mid- 1999 as the initial operating science model under the Models - 3 framework. The most recent rendition is CMAQ version 4.4, which was released in October 2004. Another reason for choosing CMAQ as the atmospheric model is the ability to do one atmospheri c modeling. S ince the same modeling exercise is required for the ozone and PM 2.5 attainment demonstrations SIPs, as well as the regional haze SIP, having a model that can handle both ozone and particulate matter is essential. Anumber of features in the theoretical formulation and technical implementation of CMAQ make the model well suited for annual particulate matter modeling.C - HCAPCB - 24 - PM 2.5 SIP

The configuration used for this modeling demonstration, as well as a more detailed description of the CMAQ model, can be found in the VISTAS Modeling Protocol (Appendix 5 ). **2 .2.2 Selection of Meteorological Model**  Criteria Meteorological models, either through objective, diagnostic, or prognostic anal ys is, extend available information about the state of the atmosphere to the grid upon which photochemical grid modeling is to be carried out. The criteria for selecting a meteorological model are based on both the models ability

to accurately

replicate important meteorological phenomena in the region of study, and the model's ability to interface with the rest of the modeling systems, particularly the air quality

model. With these issues in mind, the following criteria were established for the meteorological model to be used in this study .  Non-hydrostatic f

ormulation  Reasonabl y current, peer reviewed formulation  Simulates c loud physics  Publicly

available at no or low cost  Output available in I/O APIformat  Supports f

our dimensional data assimilation  Enhanced treatment of p lanetary b oundary l ayer heights for air quality modelingC - HCAPCB - 25 - PM 2.5 SIP

Overview of MM5 The non-hydrostatic MM5 model is a three - dimensional, limited- area, primitive equation, prognostic model that has been used widel y in regional air quality model applications. The basic model has been under continuous development, improvement, testing and open peer-review for more than 20 ye ars and has been used worldwide by hundreds of scientists for a variety of mesoscale studies. MM5 uses a terrain- following non - dimensionalized pressure, or “sigma,” vertical coordinate similar to that use d in many operational and research models. In the non -hydrostatic MM5, the sigma levels are defined according to the initial hydrostatically-balanced reference state so that the sigma levels are also time - invariant. The gridded meteorological fields prod uced by MM5 are directly compatible with the input requirements of “one atmosphere” air- quality models using this coordinate. MM5 fields can be easily used in other regional air quality models with different coordinate systems by

p erforming a vertical interpolation, followed by a mass - conservation re adjustment. D istinct planetary boundary- layer parameterizations are available for air- quality applications, both of which represent sub - grid- scale turbulent fluxes of heat, moisture, and momentum. One scheme uses a first- order eddy diffusivity f ormulation for stable and neutral environments and a modified first- order scheme for unstable regimes. The other scheme uses a prognostic equation for the second- order turbulent kinetic energy, while diagnosing the other key boundary layer terms. Initial and lateral boundary c onditions are specified for real - data cases from mesoscale three dimensional analyses performed at 12 -hour intervals on the outermost grid mesh selected by the user. Surface fields are analyzed at three -hour intervals. ACressman-based technique is used to anal yz e standard surface and radiosonde observations, using the National Meteorological Center’s spectral anal ys is, as a first guess. The lateral boundary data are introduced using a relaxati on technique applied in the outermost five rows and columns of the coarsest grid domain. The configuration used for this modeling demonstration, as well as a more detailed description of the MM5 model, can be found in the modeling protocol (Appendix 5 ) . **2 .2.3**  **Selection of Emissions Processing System** Criteria The principal criterion for an emissions processing system is that it accurately p repares emissions files in a format suitable for the photochemical grid model being used. The following list includes clarification of this criterion and additional desirable criteria for effective use of the system.

 File s ystem c ompatibility with the I/O API  File p ortability  Ability

to grid emissions on a Lambert c onformal projection  Report c apabilityC - HCAPCB - 26 - PM 2.5 SIP

 Graphical anal ys is c apability  MOBILE6 mobile s ource emissions  Biogenic Emissions Inventory S ystem (BEIS3 ) m odel  Ability

to process emissions for the proposed domain in a reasonable amount of time  Ability

to process control strategies  No or low cost for acquisition and maintenance  Expandable to support other species and mechanisms Overview of SMOKE The Sparse Matrix Operator Kernel Emissions (SMOKE) Processing System Prototy pe was originall y developed at the Micro - computing Center of North Carolina. A s with most emissi ons models, SMOKE is principally an emission processing system and not a true emissions modeling system in which emissions estimates are simulated from “first principles.” This means that, with the exception of mobile and biogenic sources, its purpose is to provide an efficient, modern tool for converting emissions inventory data into the formatted emission files required by an air quality simulation model. For mobile sources, SMOKE actually s imulates emissions rates based on input mobile - source activity data, emission factors, and outputs from transportation travel demand models. SMOKE was originally

designed to allow emissions data processing methods to utilize emergent high-performance - computing as applied to sparse -matrix algorithms. Indeed, SMOKE is the fastest emissions processing tool currentl y available to the air quality modeling community . The sparse matrix approach utilized throughout SMOKE permits both rapid and flexible processing of emissions data. The processing is rapid because SMOKE uti lizes a series of matrix calculations instead of less efficient algorithms used in previous systems. The processing is flexible because the processing steps of temporal projection, controls, chemical speciation, temporal allocation, and spatial allocation have been separated into independent operations wherever possible. The results from these steps are merged together at a final stage of processing. SMOKE contains a number of major features that make it an attractive component of the modeling system. The model supports a variety o f input formats from other emissions processing systems and models. It supports both gridded and county total land use scheme for biogenic emissions modeling. S MOKE can accommodate emissions files from up to 10 countries and any pollutant can be processed by the system. For additional information about the SMOKE model please refer to the modeling protocol (Appendix 5 ).C - HCAPCB - 27 - PM 2.5 SIP

**2 .2.4 Selection of Modeling Year**  A crucial step to SIP modeling is the selection of the period of time to model to represent current air quality

c onditions and to project changes in air quality in response to changes in emissions. The year 2002 was selected as the base year for several reasons. The Attainment Modeling Guidance identifies specific goals to c onsider when selecting one or more episodes for use in demonstrating reasonable progress in attaining the regional haze air quality goals. The EPA recommends that episode selection derive from the following four principal criteria .  Simulate a variety of meteorological conditions  Model time periods in which observed concentrations are close to the appropriate baseline design value or visibility impairment  Model periods for which extensive air quality /meteorological data bases exist  Model a sufficient number of days so that the modeled attainment test applied at each monitor violating the NAAQS is based on multiple days VI STAS adopted a logical, stepwise approach in implementing the Attainment Modeling Guidance in order to identify the most preferable, representative modeling ye ar. This approach included the following steps .  Representativeness of Meteorological Conditions : The VI STAS identified important meteorological characteristics and data sets in the VI STAS region directly relevant to the evaluation of candidate annual modeling episodes.  Initial Episode Ty

ping : At the time of selection in 2003, meteorological and air quality data were available for 2002 for model inputs and model performance evaluation. VI STAS used Classification and Regression Tree (CART) anal ys es to evaluate the candidate modeling years. The ye ar 2002 was found to be representative of conditions in the other ye ars. Subsequently, these anal ys es were repeated with the meteorological and air quality

monitoring data for 2000 to 2004 to evaluate how well the 2002 modeling year represented the full 2000 - 2004 baseline period. This anal ys is confirmed that visibility and PM 2.5 concentrations in 2002 were representative of the five - year baseline period. This analysis is discussed in more detail in Appendix 5.  Data Availability : In parallel with the CART analys e s, episode characterization analyses, collaborative investigations by V IS TAS states (e.g., North Carolina Department of Air Quality, Ge orgia Department of Natural Resources, and Florida Department of Environmental Protection) intensively studied the availability

o f PM 2.5, meteorological and emissions data , and representativeness of alternative baseline modeling periods from a regulatory

standpoint. Additionally, 2002 was the year that the EPA was requiring states to provide emissions inventory data for the Comprehensive Emissions Reporting Rule, it was appropriate to use 2002 as the modeling ye ar to take advantage of the 2002 inventory .C - HCAPCB - 28 - PM 2.5 SIP

 Years to be used by

other Regional Planning Organization s : VI STAS also considered what years other regional planning organizations would be modeling, and several had already chosen calendar year 2002 as the modeling year. After a lengthy

process of integrated studies, the episode selection process culminated in the selection of calendar year 2002 (January 1 through December 31 ) as the most current, representative, and pragmatic choice for modeling. All of the EPA criteria for model ye ar selection were directl y considered in this process together with many other considerations (e.g., timing of new emissions or aerometric data deliveries by the EPA or the states to the modeling teams). **2 .3**  **Modeling Domains** H orizontal Modeling Domain The CMAQ model was run in the one - way n ested grid mode. This allowed the larger outer domains to feed concentration data to the inner nested domain. One -way nesting is believed to be appropriate for the generall y stagnant or near stagnant conditions experienced in the region. Two -way nesting was not considered due to numerical and computational uncertainty associated with the technique. The horizontal coarse grid modeling domain boundaries were determined through a national effort to develop a common grid projection and boundary . S ince this national modeling domain was used in the VI STAS regional haze modeling, it was used for the attainment demonstration as well. Asmaller 12 -km grid, modeling domain was selected in an attempt to balance location of areas of interest, such as ozone and fine particulate matter nonattainment areas, as well as Class 1 and wilderness areas for regional haze. Processing time was also a factor in choosing a smaller 12 -km grid, modeling domain. The coarse 36 -km horizontal grid domain covers the continental United States. This domain was u sed as the outer grid domain for MM5 modeling with the CMAQ domain nested within the MM5 domain. F igure 2 - 1 shows the MM5 horizontal domain as the outer most, blue grid with the CMAQ 36 -km domain nested in the MM5 domain.C - HCAPCB - 29 - PM 2.5 SIP

**Figure 2**  **- 1**  **. MM5**  **H orizontal**  **D om**  **ain (Blue) with Nested**  **CMAQ 36 -**  **km D**  **om ain**  To achieve finer spatial resolution in the VI STAS states, a one -way n ested high resolution (12 -km grid resolution) was used. F igure 2 - 2 shows the 12 -km grid, modeling domain for the VI STAS region. This is the modeling domain for which the attainment test results are based. VI STAS conducted a study to determine if using a finer grid resolution provided different modeling results. S ince the EPA attainment test uses the modeling results to determine the relative re ductions in PM 2.5 , it was determined that effectively the same attainment test results are obtained from 12 -km grid modeling or 4 -km grid modeling. Since 4 -km grid modeling takes significantl y more time and resources to run, the ASIP decided to use the VI STAS 12 -km grid modeling results for this attainment demonstration. This is in accordance with the Attainment Modeling Guidance. According to EPA, “are as without strong gradients in primary particulate matter will likely

have little benefit from fine scale resolution.” Primary particulate matter is not a significant contributor to this area’s nonattainment problem as shown in the monitored data.C - HCAPCB - 30 - PM 2.5 SIP **Figure 2**  **- 2**  **. ASIP/VISTAS Region 12**  **- km Grid**  Vertical Modeling Domain The CMAQ vertical structure is primari ly defined by

the vertical grid used in the MM5 modeling. The MM5 model employed a terrain following coordinate system defined by pressure, using thirty- four layers that extend from the surface to 100 mb. T able 2 - 17 , which follows, lists the layer definitions for both MM5 and for CMAQ. Al ayer- averaging scheme is adopted for CMAQ to reduce the computational cost of the CMAQ simulations. The effects of layer averaging were evaluated in conjunction with the VI STAS modeling effort and were found to have a relatively

minor effect on the model perf ormance metrics when both the thirty- four layer and nineteen layer CMAQ models were compared to ambient monitoring data.C - HCAPCB - 31 - PM 2.5 SIP **Table 2**  **- 17**  **. Vertical Layer Definition**  **f or MM5 and CMAQ**  MM5 Layers CMAQ Layers Layer Sigma Pressure

(mb) Height

(m) Depth (m) Layer Sigma Pressure (mb) Height

(m) Depth (m) **34 0.000**  **100 14,662**  **1,841 19**  **0.000 100**  **14,662 6,536**  33 0.050 145 12,822 1,466

– 0.050 145

– – 32 0.100 190 11,356 1,228

– 0.100 190

– – 31 0.150 235 10,127 1,062

– 0.150 235

– – 30 0.200 280 9,066 939

– 0.200 280

– – **29 0.250**  **325 8,127**  **843 18**  **0.250 325**  **8,127 2,966**  28 0.300 370 7,284 767

– 0.300 370

– – 27 0.350 415 6,517 704

– 0.350 415

– – 26 0.400 460 5,812 652

– 0.400 460

– – **25 0.450**  **505 5,160**  **607 17**  **0.450 505**  **5, 160**  **1,712** 24 0.500 550 4,553 569

– 0.500 550

– – 23 0.550 595 3,984 536

– 0.550 595

– – **22 0.600**  **640 3,448**  **506 16**  **0.600 640**  **3,448 986**  21 0.650 685 2,942 480

– 0.650 685

– – **20 0.700**  **730 2,462**  **367 15**  **0.700 730**  **2,462 633**  19 0.740 766 2,095 266

– 0.740 766

– – **18 0.770**  **793 1,828**  **259 14**  **0.770 793**  **1,828 428**  17 0.800 820 1,569 169

– 0.800 820

– – **16 0.820**  **838 1,400**  **166 13**  **0.820 838**  **1,400 329**  15 0.840 856 1,235 163

– 0.840 856

– – **14 0.860**  **874 1,071**  **160 12**  **0.860 874**  **1,071 160**  **13 0.880**  **892 911**  **158 11**  **0. 880**  **892 911**  **158 12**  **0.900 910**  **753 78**  **10 0.900**  **910 753**  **155** 11 0.910 919 675 77

– 0.910 919

– – **10 0.920**  **928 598**  **77 9**  **0.920 928**  **598 153**  9 0.930 937 521 76

– 0.930 937

– – **8 0.940**  **946 445**  **76 8**  **0.940 946**  **445 76**  **7 0.950**  **955 369**  **75 7**  **0.950 955**  **369 75**  **6 0.9**  **60 964**  **294 74**  **6 0.960**  **964 294**  **74 5**  **0.970 973**  **220 74**  **5 0.970**  **973 220**  **74 4**  **0.980 982**  **146 37**  **4 0.980**  **982 146**  **37 3**  **0.985 986.5**  **109 37**  **3 0.985**  **986.5 109**  **37 2**  **0.990 991**  **73 36**  **2 0.990**  **991 73**  **36 1**  **0.995 995.5**  **36 36**  **1 0.995**  **995.5 36**  **36 0**  **1.000 1,000**  **0 0**  **0 1.0**  **00 1,000**  **0 0** C - HCAPCB - 32 - PM 2.5 SIP

**2 .4**  **Boundary Conditions** The GEOS - CHEM global chemical transport model , which is managed and supported by the Atmospheric Chemistry Modeling Group at Harvard University, was used to develop the boundary c onditions of the modeling domain . Appendix 6 contains a report titled Application of GEOS CHEMfor 2002 Boundary Conditions for CMAQ Modeling of the VISTAS Region by Ivar Tombach dated October 5, 2007 , which details the process. The following three full -ye ar 2002 simulations were run.

 A b aseline simulation with best estimates of 2002 emissions  A background simulation modified from the baseline by shutting off U.S. anthropogenic emissions which included fuel, industrial, and agricultural sources but not biomass burning  A natural simulation modified by shutting off anthropogenic emissions worldwide. Three dimensional concentration fields with three -hour temporal resolution were archived from each simulation to serve as boundary c onditions for CMAQ. Amodel performance evaluation was conducted through comparisons of the baseline simulation to Interagency M onitoring of Protected Visual Environments (IMPROVE) and Clean Air Status and Trends Network (CASTNET) observations in the United States. **2 .5**  **Initial Conditions** CMAQ default initial concentrations were used with a spin up period of approximately f ifteen days to eliminate any

significant influence of the initial conditions. **2 .6**  **M odel Performance Evaluation**  A model performance evaluation was accomplished for VI STAS as part of the Regional Haze SIP process . A detailed evaluation of the model performance is included in Section 7 .0 of the modeling protocol (Appendix 5 ) , in Chapter 3 and Appendix B of the Technical Support Document for ASIP Emissions and Air Quality Modeling to Support Fine Particulate State Implementation Plans (Appendix 4) and in the Technical Support Document for VI STAS (Appendix 4) . ASIP , as discussed previously, utilized the modeling for regional haze to also demonstrate that the area will attain the PM 2.5 standard b y the end of 2009 as required. Though there are no EPA designated metrics, there are metrics that have been used in several studies. Appendix B of the Attainment Modeling Guidance provides examples of the metrics and the goals and criteria for their use in other modeling studies. The following metrics and performance measures are presented to demonstrate adequate model performance .C - HCAPCB - 33 - PM 2.5 SIP

Mean fractional bias (MFB) and mean fractional error (MFE) are the performance metrics used for the evaluation. The goal for MFB is within thirty percent . The goal for the MFE is less than or equal to fifty percent . The criterion for the MFB is within ± sixty percent . As stated in Appendix B of the Attainment Modeling Guidance,

“ . . .proposed to use asymptotically a pproaching and criteria when data are greater than 2.5 μm, approaching +200% MFE and ±20 0% MFB for extreme small model and observed data (formula of logarithmic MFB and MFE are proposed) . Based on combined modeling studies ... for more abundant conditions MFE and MF B are typical in the range of : Sulfates : MFE = 30%

– 77% MFB = –45%

– +51% (> 2 μg/m 3 ) Nitrates : MFE = 55%

– 125% MFB = +3%

– +82% (> 1 μg/m 3 ) Organic carbon : MFE = 35%

– 95% MFB = –70%

– +35% (> 1.5 μg/m 3 ) Elemental carbon : MFE = 50%

– 95% MFB = –45%

– +50% (> 0.5 μg/m 3 ) PM 2.5 : MFE = 50%

– 85% MFB = –55%

– +60% (> 5 μg/m 3 ) ” Bugle plots and time series plots for each of the components of particulate matter show MFE and MFB. The bugle plots are shaped as shown because the goal and criteria lines are adjusted based on the average concentration of the observed species. The bugle plots and time series plots are located in Appendix 7 entitled Local Area Model Performance . Modeling some components resulted in better model performance than others. Elemental c arbon, sulfates, and ammonium all met the criteria for both MFB and MFE . Nitrates did not meet fractional bias criteria at low concentrations. Organic carbon met the criteria but did not meet the goal . Though not all values are in the desired range , the performance at the Siskin Drive/UTC FRM (470654002) in Hamilton County, which is critical for the modeled attainment demonstration , is satisfactory . Table 2 - 18 shows the MFEs and MFBs for the Siskin Drive FRM.

**Table 2 -**  **18 . MFE and MFB for**  **the Siski n Drive/UTC FRM (470654002)**  Pollutant Mean Fractional Error (MFE) Mean Fractional Bias (MFB) Sulfates 37.55%

– 17.00% Nitrates 118.07%

– 86.17% Organic Carbon 59.81%

–55.52% Elemental Carbon 40.15%

–23.46% PM 2.5 40.63%

–31.56%C - HCAPCB - 34 - PM 2.5 SIP

**3 .0 ATTAINMENT DEMONST**  **RATION** An attainment demonstration consists of anal ys es that estimate whether selected emissions reductions will result in ambient concentrations that meet the NAAQS and an identified set of control measures which will result in the required emissions reductions. The necessary emission reductions for both of these attainment demonstration components may be determined by

rel ying on results obtained with air quality models. Section 3.0 of the Attainment Modeling Guidance recommends applying both a modeled attainment test and a subsequent screening test (or unmonitored area analysis) to the air quality modeling results to determine if the annual PM 2.5 NAAQS will be met. Additional technical or corroboratory

analyses may

also be used as part of a “supplemental anal ys is” or a more stringent “weight of evidence” determination to supplement the modeled attainment test and to further support a demonstration of attainment of the NAAQS. **3 .1 Speciated Modeled Attainment Test**  The purpose of a modeling assessment i s to determine if control strategies currentl y being implemented and proposed control strategies will lead to attainment of the annual PM 2.5 NAAQS by the attainment ye ar of 2009. The modeling is applied in a relative sense, similar to the 8 -hour ozone attainment test. H owever, the PM 2.5 attainment test is more complicated and reflects the fact that PM 2.5 is a mixture. In the test, ambient PM 2.5 is divided into major components, with a separate relative response factor (RRF) and future design value (DVF) calculated for each of the PM 2.5 components. S ince the attainment test is calculated on a per species basis, the attainment test for PM 2.5 is referred to as the Speciated Modeled Attainment Test (SMAT). In its entirety, SMAT consists of four basic steps. First, the observed quarterly mean PM 2.5 and quarterl y mean composition for each monitor is calculated. This is achieved by multiplying the monitored quarterl y mean concentration of PM 2.5 from FRMs by

the monitored fractional composition of PM 2.5 specie s for each quarter [ e.g., (20% sulfate) × (15.0 μg/m 3 PM2.5 mass) = 3.0 μg/m 3 sulfate mass) ] . The monitored quarterl y mean concentration of PM 2.5 from FRM s are the five - ye ar baseline design values that are the result of averaging the three current design values that straddle the modeling base ye ar. The fractional composition of PM 2.5 species is derived from speciation monitoring site data that has been processed by

the “sulfate, adjusted nitrate, derived water, inferred carbonaceous material balance appro ach , ” or SANDWICH method, so that speciation and FRM masses are equivalent. The mean composition derived from the SANDWICH method includes the percent of PM 2.5 that can be attributed to sulfates , nitrates , organic carbon , elemental carbon , other primary inorganic particulate matter (or crustal material), ammonium , and particle bound water. Data from the STN monitor at the Siskin Drive/UTC site was used in conjunction with all four FRMs in the nonattainment area. The second step is to use model results to derive component specific RRFs for each monitor for each quarter. The RRF is the ratio of the model’s future projections to the baseline current projections for each component.C - HCAPCB - 35 - PM 2.5 SIP

For the third step, the component specific RRFs are applied to the observed air quality concentrations to project quarterl y species estimates. F or each quarter, the current quarterl y mean component concentrations from the first step are multiplied by the component- specific RRFs obtained in the second step. This leads to an estimated future quarterl y mean concentration for each component. The fourth step sums the quarterly c omponents to get a quarterly m ean PM 2.5 value. These quarterl y mean values are then averaged to produce a future ye ar annual average PM 2.5 estimate, or DVF, for each FRM site. This final value is then compared to the NAAQS (15.0 μg/m 3 ) to determine if attainment is reached. Documentation of the SMAT methodology and results are detailed in Sections 8.2 through 8.2.2 of the Modeling Protocol, which can be found in Appendix 5, and in the Hamilton County SMAT Process, which can be found in Appendix 8 . **3 .2 Attainment Test Results**  The 2008 annual average data and the three - ye ar average data is as follows for all of the PM 2.5 FRM monitors in this nonattainment area. The area monitors show that the annual average concentrations currently are at a level that demonstrates attainment. The 2008 annual average concentrations are 12.7 micrograms per cubic meter at the Siskin Drive/UTC site (470654002), 12.9 microgram s per cubic meter at the Soddy- Daisy

s ite (470651011), 13.9 micrograms per cubic meter at the East Ridge site (470650031), and 12.5 micrograms per cubic meter at the Walker County, Georgia site (1329540002). Three - ye ar annual averages (Design Value) for 2 006 - 2008 are as follows :

Federal Reference Monitor 2008 Annual 2006 - 2008

Average Siskin Drive/UTC (470654002) 12.7 14.2 East Ridge (470650031) 12.3 13.8 Soddy- Daisy

(470651011) 11.4 12.9 Walker County, Georgia (132950002) 12.5 * *Incomplete Data for 2007 The 2009 future design values for the four FRM sites in the nonattainment area are provided in Table s 3 - 1 and 3 - 2 , which follow . Since the 2009 design value at each site is less than the annual PM 2.5 NAAQS of 15.0 μ g/m 3 , the area has passed the attainment test portion of the attainment demonstration.C - HCAPCB - 36 - PM 2.5 SIP **Table 3 -**  **1 .**  **2009 Quarterly Mean and Annual PM 2.5**  **Design Values**

Federal Reference Monitor PM 2.5 Design Value ( μg/m 3 ) Quarter **Annual** 1st 2nd 3rd 4th Siskin Drive/UTC (470654002) 12.2 13. 7 15.3 13.0 **13.6** Maxwell Road/East Ridge (470650031) 13.8 14.8 15.6 13.4 **14.4** Soddy- Daisy

High School (470651011) 12.2 13.2 14.7 9.3 **12.3** Walker County, Georgia (132950002) 12.6 14.9 16.0 12.2 **13.9**

**Table 3**  **- 2**  **. 2009 Modeled Species and**  **Annual PM** **2.5 Design Values** 

Federal Reference Monitor Modeled Concentrations ( μg/m 3 ) * Average Crustal Material Average

Elemental Carbon Average

Organic Carbon Average

Sulfates Average

Nitrates Average

Ammonium Average

Particle Bound Water Blank Filter Mass **PM 2.5**  **Design Value**  Siskin Drive/UTC (470654002) 0.970 0.498 5.230 3.845 0.178 1.207 1.135 0.5 **13.6** Maxwell Road/East Ridge (470650031) 1.023 0.522 5.614 4.068 0.190 1.277 1.201 0.5 **14.4** Soddy- Daisy

High School (470651011) 0.902 0.448 4.795 3.458 0.146 1.080 1.020 0.5 **12.3** Walker County, Georgia (132950002) 0.978 0.509 5.446 3.914 0.188 1.230 1.153 0.5 **13.9** * Passively collected mass, or the mass of the blank filter, has a constant value of 0.5 μg/m 3 for each FRM. **3 .3**  **Supplemental Analyses/Weight of Evidence** The Attainment M odeling Guidance asserts that all attainment demonstrations should be accompanied by

supplemental analysis that further supports the modeling conclusions. This su pplemental anal ys is can include additional analyses of air quality, emissions , and meteorological data and may c onsider modeling outputs other than the results of the attainment test. I f the attainment test results fall short of the standard, the results of corroboratory anal ys es may b e used in a weight of evidence determination to show that attainment is likely despite modeled results, which may be inconclusive.C - HCAPCB - 37 - PM 2.5 SIP

The Attainment Modeling Guidance defines the guideline for supplemental anal ys is/weight of evidence for the annual PM 2.5 standard as follows:

 Sites with a DVF less than 14.5 μ g/m 3 should submit basic supplemental anal ys is to confirm the outcome of the model attainment test.  Sites with a DVF between 14.5 μ g/m 3 and 15.5 μ g/m 3 should submit a weight of evidence demonstration to aggregate supplemental anal ys is to support the model attainment demonstration.  Sites with a DVF greater than or equal to 15.5 μ g/m 3 should consider additional control measures to ensure attainment, as more qualitative anal ys is is unlikel y to support a conclusion differing from the outcome of the modeled attainment test. All monitoring sites in the nonattainment area have DVFs lower than 14.5 μ g/m 3 . Therefore, the following section is a supplemental anal ys is to corroborate modeling results, rather than a weight of evidence anal ys is to show attainment. **3 .**  **3 .1**  **Emissions Reductions Not Modeled**  Electric Utilities Georgia Rules for Air Quality C ontrol Chapter 391 - 3 - 1 Rule (sss) “Multipollutant Control of Electric Steam Generating Units” requires additional SO 2 reductions that were not included in the 2009 Emissions Inventory f or the attainment model. By June 1, 2009, the Bowen Plant Unit 2 must operate selective catal ytic reduction and flue gas desulfurization. The changes will result in 19,328 tons reduction in SO 2 emissions between June and December 2009. Bowater Newsprin t

– Calhoun Operations Bowater Newsprint

– Calhoun Operations (Bowater) is a paper manufacturing plant located thirty miles from the Maxwell Road/East Ridge monitoring site. This source is not in the nonattainment area and the permits for this source are not within the jurisdiction of the Chattanooga - Hamilton County Air Pollution Control Bureau. The facility provided the State of Tennessee with updated emi ssions that contained weight of evidence information showing emissions reductions near this nonattainment area that were less than the modeled emissions. In an October 31, 2007, letter (Appendix 9 ) from Bowater’s Director of Environmental Affairs, Mr. J. W . O’Grady, the company reports the SO 2 emissions were overestimated in the 2009 emissions inventory u sed in the ASIP model. The error was due to overestimates of coal sulfur content by approximately thirty- four percent and future coal firing by a pproximately sixteen percent. The ASIP modeling showed that the emissions of SO 2 were 5,379 tons in 2009. In their letter, Bowater indicates that using the correct coal sulfur content and future coal firing would lower the SO 2 emissions used as model input by forty percent. In addition to the correction of SO 2 emissions input, Bowater provided clarification of the company’s seasonal coal - firing rates. The ASIP model inventories assumed that SO 2 emissionsC - HCAPCB - 38 - PM 2.5 SIP

were equall y distributed throughout the year. The company ’s boilers are used primarily to heat river water. During the summer months when the river is warmer, monthly coal usage is almost half that of the winter months. According to the Georgia Institute of Technology s ensitivity modeling, which will be detail ed in Section 4.1.2 of this document, the conversion of non- EGU sources’ SO 2 emissions to sulfates is ten times higher in the summer than the winter. Thus Bowater’s actual fuel use profile, with less coal burning in the summer results in decreased sulfate s. **3 .3**  **.2 Status of**  **Modeled Emissions Reductions**  Fuel Changes On-road and non- road diesel fuel and gasoline will contain far less sulfur in 2009 than in 2002. Despite expected growth of on-road and non-road vehicle uses, federal fuel sulfur reductions result in SO 2 emission reductions of 317 tons per ye ar from non-road vehicles and 402 tons per ye ar from on- road mobile sources. As of November 21, 2007, three of the four fuel terminals for diesel fuel in Hamilton County stock only

ultra- low sulfur diese l fuel. The local sulfur levels in gasoline are about 30 ppm at this time. One hundred eighty- five diesel school buses are operated by a c ontractor in the Chattanooga urban area. One hundred eighty-two of these were built in 2007, and the remaining three were built in 2008. All of these buses are equipped with diesel particulate filters. The contractor reported, in November 2007, that they had not experienced any difficulties with the performance of the school buses. The City o f Chattanooga also operates diesel -powered garbage trucks that were all built in 2007. They too report no problems with the diesel particulate filters. Industrial Sources Hamilton County

s ources make up a small portion of the sources in the modeling domain. Emissions of PM 2. 5 and precursors have continued to decrease. Traditional heavy manufacturing industries continue their long term decrease in Hamilton County. In this jurisdiction, there were 243 industrial point sources in 1999. O f these, twenty-two were Title V major sources and eighty- eight were sy

nthetic minor sources. T oday there are 20 7 industrial point sources, which include nineteen Title V sources and seventy- five sy nthetic minor sources. Industrial source emissions for the period have trended downward as well . Figures 3 - 1 through 3 - 7 , which follow, chart these emissions trends as reported in the Chattanooga- Hamilton County Air Pollution Control Bureau emission s inventories between 1999 and 2007. Individual industrial point source emissions from the inventori es are provided in Appendix 10. Emissions of PM2.5 were not inventoried prior to 2002 . With greater availability o f emission factors, the PM2.5 emissions inventory has improved.C - HCAPCB - 39 - PM 2.5 SIP 

### PM **2. 5** 

### E **MI SSI**  **ONS**

0 50 100 150 200

2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 1 . Hamilton County Emissions of PM 2.5 

### PM **10**

### E **MI SSI**  **ON S** 

0 200 400 600 800 1000 1200 1400 1600

1999 2001 2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 2 . Hamilton County Emissions of PM 10C - HCAPCB - 40 - PM 2.5 SIP 

### SU **LFU R**  **DI OXI**  **DE (S**  **O 2**  

### ) E **MI SSI**  **ONS**

0 1000 2000 3000 4000 5000

1999 2001 2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 3 . Hamilton County Emissions of Sulfur Dioxide (SO 2 ) 

### NI **TRO GE**  **N OXI**  **DE S**  **(N O**  **X** 

### ) E **MI SSI**  **ONS**

0 1000 2000 3000 4000 5000

1999 2001 2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 4 . Hamilton County Emissions of Nitrogen Oxides (NO X)C - HCAPCB - 41 - PM 2.5 SIP 

### TO **LU EN**  **E EM**  **IS SI**  **ON S** 

0 10 20 30 40 50 60 70

1999 2001 2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 5 . Hamilton County Emissions of Toluene 

### XY **LE NE**  **S EM**  **IS SI**  **ON S** 

0 20 40 60 80 100

1999 2001 2003 2005 2007 **Ye ar** **T o** **n s** 

Figure 3 - 6 . Hamilton County Emissions of XylenesC - HCAPCB - 42 - PM 2.5 SIP 

### AM **MO NI**  **A EMI**  **SSI ONS** 

0 5 10 15 20 25 30 35

1999 2001 2003 2005 2007 **Ye ar** **s T** **o n** **s**

Figure 3 - 7 . Hamilton County Emissions of Ammonia Electric Utilities The CAIR is in place, and electric utilities are complying with the rule. G eorgia Rules for Air Quality C ontrol Chapter 391 - 3 - 1 Rule (sss) “Multipollutant Control of Electric Steam Generating Units” has been adopted. Under this rule, the Hammond Plant near Rome, Georgia is required to have desulfurization equipment installed and operating by D ecember 31, 2008. The Bowen Plant in Bartow County i s required to have operational desulfurization equipment installed and operating on Units 3 and 4 by D ecember 31, 2008. The combined SO 2 emissions from the two plants are estimated to be reduced by 9 2,104 tons per ye ar by

the end of 2008. A wind from 184 ° carries the emissions from the Hammond Plant directly to the Maxwell Road/East Ridge monitor (470650031). Awind from 161 ° carries emissions from the Bowen plant to the Maxwell Road/East Ridge Monitor (470650031). Miscellaneous Sources In2 005, a seasonal open burning ban was put in place in Hamilton County . One small city has closed its air curtain destructor, and the City o f Chattanooga no longer burns brush in their air curtain destructor. The air curtain destructor is maintained for use only f or major storm brush cleanup as allowed by

F ederal rules. C itizen open burning has also decreased. F or example, in 1994, there were 7,131 open burning permits issued in Hamilton County. F or the 2006 - 2007 burning season, 5,510 permits were issued. D ecreased open burning is known to re duce elemental carbon, organic carbon, and direct PM2.5 emissions.C - HCAPCB - 43 - PM 2.5 SIP

Chattanooga has continued to encourage bicycle use. B oth the City and major employers have installed bicycle racks in the downtown area. All Chattanooga Regional Transportation Authority mainline buses are equipped with bike racks. Approximately three thousand riders use the bike racks on the buses. **3 .3**  **.3 Status of Attainment for Surrounding Counties**  In addition to the modeling results for the nonattainment area, all monitors in the c ounties surrounding this nonattainment area also show attainment in 2009. Table 3 - 3 lists the 2009 DVFs for FRMs located in counties that surround Hamilton County . **Ta ble 3**  **- 3**  **. Surrounding Area 2009 Modeled Annual PM 2.5**  **Design Values** Federal Reference Monitor PM 2.5 Design Value ( μg/m 3 ) DeKalb County, Alabama (010491003) 13.3 Madison County, Alabama (010890014) 12.8 Floyd County, Georgia (131150005) 14.0 McMinn County, Tennessee (471071002) 13.2C - HCAPCB - 44 - PM 2.5 SIP

**4.0 PM 2.5**  **RACT/RACM** The PM 2.5 Implementation Rule (40 CFR 51.1010) requires that “For each PM 2.5 nonattainment area, the state shall submit with the attainment demonstration a SIP revision demon strating that it has adopted all reasonably available control measures (including RACT for stationary s ources) nece ssary to demonstrate attainment as expeditiously as practical and to meet any reasonable further progress requirements. The SIP revision shall contain the list of potential measures considered by

the state and information and analysis sufficient to support the state’s judgment that it has adopted all RACM including RACT.” RACM can appl y to industrial sources, mobile sources, open burning, heating, etc. RACT is a subset of RACM that applies to industrial sources, and it is defined as “the lowest emissions limitation that a particular source is capable of meeting by

the application of control technology that is reasonabl y available considering technological and economic feasibility .” The PM 2.5 Implementation Rule further states, “In determining whether a p articular emission reduction measure or set of measures must be adopted as RACM under S ection 172(c)(1) of the Act, the state must consider the cumulative impact of implementing the available measures. Potential measures that are reasonabl y available cons idering technical and economic feasibility must be adopted as RACM if, considered collectively, they

would advance the attainment date b y one ye ar or more. ” Speciated data from the STN monitor at the Siskin Drive/UTC site was used help identify principle sources of emissions of PM2.5 and its precursors to be considered for emission controls or reductions. According to this monitoring data, other primary particulate matter and elemental carbon each make up less than five percent of the total PM 2.5 mass. Existing local regulations already address the primary l ocal sources of elemental carbon

– on- road mobile sources, industrial boilers, process heaters, and open burning. Additional regulation of local sources of direct PM 2.5 emissions is unlikely to result in a measurable reduction of PM 2.5 due to their small contribution to the total, the emission and opacity limitations that are in place for all permitted stationary sources of particulate matter emissions in Hamilton County, and the uncertainty o f some of the PM 2.5 emission factors. The EPA has determined that their emission factors for PM 2.5 from natural gas combustion are overestimated. A s a result, the EPA reduced such emissions in the 2002 NEI by a bout ninety- five percent. D ocumentation to support this reduction is found in Appendix 11 . Monitoring data reveals that sulfates are one of the largest components of PM2.5 in this area. Depending on the specific ye ar, sulfates account for twenty- five percent to thirty-two percent of the total PM 2.5 mass. As stated previously, sulfates are pollutants caused by S O 2 emissions, primarily f rom coal - fired power plants outside of Hamilton County . In 2002, combined SO 2 emissions from all sources within Hamilton County were 3,222 tons per year compared to 44,206 tons per ye ar from the TVA Widows Creek Fossil Plant in Jackson County, Alabama, which is the closest of four regional coal - fired power plants located within 75 miles of the county. Primary l ocal sources of SO 2 emissions are motor vehicles (both on- road and non-road) and industrial boilers that use a fuel other than natural gas. Ultra- low sulfur transportation fuels are being phased in for both on-road and non-road vehicles. The primary f uel that is used by

most industrial combustion sources in Hamilton County i s natural gas, which contains a negligible amount of sulfur.C - HCAPCB - 45 - PM 2.5 SIP

Organic carbon is also one of the largest components of PM 2.5 in this area. The portion of PM2.5 that is organic carbon ranges from twenty- eight percent to thirty-two percent. O rganic carbon is produced from condensation of high molecular-weight VOCs; reactions in the atmosphere of toluene, xylenes, and trimethylbenzenes that form secondary organic aerosols; atmospheric reactions of biogenic compounds; open burning; home heating with wo od; on-road and non -road vehicles; and stationary

internal combustion engines. Approximately

24 tons of high molecular- weight VOCs are emitted annually in the county, all of which are generated by

one Title V industrial source. S crubbers, demisters, and electrostatic precipitators are used to control these emissions to RACT levels in accordance with Section 4 - 41, Rule 26 of the Chattanooga - Hamilton County Air Pollution Control Ordinance (the Ordinance). There are currentl y 34 tons per ye ar of toluene and 41 tons per ye ar of xylenes emitted annually

f rom permitted industrial sources in Hamilton County . These emissions are regulated under Section 4 - 41, Rule 25 of the Ordinance, which requires BACT for VOCs. No emissions of trimethylbenzenes are reported in the local emissions inventory. Reactive biogenic emissions from the nonattainment area and the surrounding counties were estimated by the EPA BEIS 3.09 model to be 94,358 tons per ye ar in 2002. Reactive biogenic VOCs produced in the nonattainment area alone in 2002 totaled 13,141 tons per year. Nitrates are generated in the atmosphere from NO X , which is a product of combustion. Nitrates constitute between six percent and eight percent of the monitored PM 2.5 . Seventy-three industrial sources emit NO X within Hamilton County . O nly two of these have NO X emissions that are greater than one hundred tons per year. An additional twenty s ources have NO X emissions greater than twenty tons per ye ar but less than one hundred tons per ye ar. All other sources hav e NO X emissions of less than twenty tons per ye ar. The largest industrial NO X source is a cement kiln that is subject to and meeting the NO X RACT requirements of the NO X SIP call. These requirements are in effect for the entire ye ar rather than just applying during the ozone season. Ammonia emissions are the source of the ammonium component of the PM 2.5 total mass. Onroad mobile sources are the largest contributor to ammonia emissions in Hamilton County. Current emissions of ammonia from permitted stationary sources in the county

are inventoried at 17 tons per year. **4 .1.**  **Permitted Stationary Sources**  Section 4 - 8 of the Ordinance requires that all stationary sources that emit regulated air pollutants above insignificant levels be permitted. There are 207 permitted stationary sources in Hamilton County . Nineteen of these are Title V sources, seventy- five are sy nthetic minor sources, and 113 are a minor sources. T itle V sources have potential emissions of greater than one hundred tons per ye ar of parti culate matter, SO 2 , NO X , VOCs, or carbon monoxide; twenty- five tons per ye ar of all hazardous air pollutants (HAPs) combined; or ten tons per ye ar of any individual HAP. Sy nthetic minor sources have accepted federally enforceable permit conditions that limit their emissions to below the Title V applicability thresholds. S emi - annual compliance reports and annual compliance certifications are required to be submitted by all Title V sources. In addition, most sy nthetic minor sources and several minor source s are required to submit periodic reports showing compliance with permit requirements.C - HCAPCB - 46 - PM 2.5 SIP

The permitting process that each source goes through requires an analysis of the pollutant emissions and emission controls. In addition, all permitted sources are evaluated annuall y for compliance with all applicable regulations. This evaluation consists of an on- site inspection and review of required records and reports. S ources inspections are also conducted in conjunction with complaint investigations and routine p atrols. Atotal of seven staff members maintain certification to perform visible emission evaluations. **4.1.1 Local Regulations** The Ordinance includes rules that regulate emissions from both new and existing stationary sources. The following Federal rules and standards have been incorporated by reference in the Ordinance.

 Federal New Source Performance Standards are adopted by reference into the Ordinance. They provide for emissions control based on the installation date of specific components.  National Emissions Standards for Hazardous Air Pollutants were promulgated as required by the 1990 Clean Air Act Amendments and are also adopted by reference into the Ordinance. These standards have resulted in reductions of both particulate matter emissions and emissions of certain aromatic compounds, such as toluene and xylenes, which react in the atmosphere to produce secondary organic aerosols. S ome standards use particulate matter as a surrogate for certain HAPs. Hamilton County

w as a nonattainment area f or total suspended particulate matter (TSP) and for the one -hour ozone standard. The community c ame into attainment for TSP in 1979 and for the one -hour ozone standard in 1989. The area has successfull y completed the requirements of an Earl y Action Compact for the eight-hour ozone standard. A s a result, the area is being designated as an attainment area for this standard. In addition, the largest source of NO X emissions in the nonattainment was subject to the NO X SIP call. These earlier nonattainment experiences and the Earl y Action Compact resulted in the adoption of rules that have significantly reduced direct PM 2.5 emissions, emissions of VOCs that result in secondary organic aerosols, and emissions that result from fuel combustion. Various local rules and regulations were adopted to bring the area into attainment with the TSP, one -hour ozone, and eight-hour ozone standards. Local rules and regulations of the Ordinance that are in effect include the following.

 Section 4 - 8(e)(2) requires best availa ble control technology

(BACT) for sources of particulate emissions that impact the former nonattainment area and that were constructed or modified after September 16, 1980.  Section 4 - 41, Rule 2 regulates emissions of NO X .  Section 4 - 41, Rule 3 regulates the opacity of visible emissions.  Section 4 - 41, Rule 4 limits fuel sulfur content.C - HCAPCB - 47 - PM 2.5 SIP

 Section 4 - 41, Rule 6 regulates and restricts open burning. This includes a county-wide ban on open burning during ozone season.  Section 4 - 41, Rule 8 regulates particulate matter emissions from fuel burning equipment.  Section 4 - 41, Rule 10 regulates particulate matter emissions from process equipment.  Section 4 - 41, Rule 11 regulates handling, processing, and storing of material in the open air and requires that measures be taken to prevent particulate matter from becoming airborne. This includes particulate matter emissions from roads, parking areas, open fields, etc.  Section 4 - 41, Rule 13 regulates emissions of SO 2 .  Section 4 - 41, Rule 25 regulates emissions of VOCs such as toluene and xylenes that react in the atmosphere to form secondary organic aerosols. R

ule 25.3 requires BACT or lowest achievable emission rate (LAER) levels of emissions control, depending on potential emission rates, for sources of VOC emissions that were c onstructed or modified after December 26, 1979. R ule 25.10 requires gasoline dispensing facilities to utilize Stage 1 vapor recovery. 1 80 gasoline dispensing facilities in Hamilton County are subject to this requirement. The use of Stage 1 vapor recovery minimizes fugitive emissions of gasoline. Although toluene and xylenes combined comprise only a bout 1.7 percent b y weight of gasoline emissions, the large quantity of gasoline dispensed contains a considerable amount of these compounds.  Section 4 - 41, Rule 26 requires RACT for sources of particulate matter emissions that were in existence before 1978. Three coal - fired boilers at one industrial source in Hamilton County

c omply with this rule by

the use of baghouses to control particulate matter emissions and the use of continuous opacity monitors.  Section 4 - 41, Rule 27 requires BACT or “reasonable and proper emissions limitations,” depending on potential emission rates, for sources of particulate matter emissions that were constructed or modified after August 29, 1995. **4.1.2 Sensitivity Modeling** The Georgia Institute of Technology c onducted sensitivity

modeling for each of the ASIP states. Seasonal sensitivities were determined from modeled PM 2.5 concentration responses to uniform emission reductions throughout Tennessee. S ensitivities were determined for emissions of NO X from point sources , SO 2 from non- EGU sources , and PM 2.5 from point sources for both summer and winter seasons. S ince these sensitivities are for statewide reductions in emissions and are not county

specific, the theoretical maximum reductions in PM2.5 concentrations that could be realized in Hamilton County are arrived at by

appl ying the sensitivities to the statewide emissions of each pollutant and assuming that all of these emissions are concentrated in Hamilton County . The resulting absolute maximum reductions that result from completely eliminating all emissions of each specified pollutant, in turn, from Hamilton County are small, ranging from PM 2.5 concentration reductions of 0.05 54 μg/m 3 for NO X point source emissions to 0.249 μg/m 3 for SO 2 non- EGU source emissions. These calculated PM 2.5 concentration reductions for Hamilton County are given below in Table 4 - 1 .C - HCAPCB - 48 - PM 2.5 SIP

**Table 4 -**  **1 .**  **Maxim um** **PM 2.5**  **Concentration Reductions from Sensitivity Modeling** 

Pollutant Emissions (tons/day) Season Sensitivity (ng/m 3 )/ (ton/day) PM 2.5 Reduction from

Total Elimination of Each Pollutant Hamilton County Tennessee

(Statewide) **NO X**  from point sources 7.501 275.6 Summer - 0.174 0.0479 μ g/m 3 577.8 Winter - 0.0958 **0.0554 μ**  **g/m 3**  **SO 2**  from nonEGU sources 8.786 230.5 Summer - 1.08 **0.249 μ**  **g/m 3**  226.7 Winter - 0.0958 0.0217 μ g/m 3 **PM 2.5**  from point sources 1.899 29.8 Summer - 5.25 **0.157 μ**  **g/m 3**  31.7 Winter - 3.51 0.111 μ g/m 3 Even though potential PM 2.5 reducti ons that are available from local sources are insufficient to bring the area into attainment before 2009, a further review was conducted as described in the PM 2.5 Implementation Rule (page 20612): “A state must consider RACT and RACM for all its nonattainment areas. H owever EPA believes that if the state projects that an area will attain the standard within 5 years of designation as a result of existing measures (i.e. projected to have a design value of 14.5 or lower), then the state may conduct a limited RACT and RACM analysis that does not involve additional air quality modeling. Al imited analysis of this ty pe would involve reasonabl y available measures, the estimate of potential emissions reductions, and the time needed to implement these measures.” S eventeen permitted sources in Hamilton County emit greater than 10 tons per ye ar of TSP, as reported in the local emissions inventory f or 2007. B ased on available emission factors, two sources emit greater than 10 tons per year of direct PM2.5 . Nineteen sources emit greater than 10 tons per ye ar of NO X . T en sources emit greater than 10 tons per ye ar of SO 2 . Thirteen sources emit more than 40 tons per ye ar of TSP, NO X , and SO 2 combined. The permits of each of these thirteen sources were examined in detail and were all found to require at least RACT levels of emissions control. The results of this review are given in Appendix 12 . This review and the results of the sensitivity

modeling indicate that no additional reductions are available from local permitted stationary

sources that would result in attainment in 2008 rather than 2009.C - HCAPCB - 49 - PM 2.5 SIP

**4 .**  **2 Gasoline**  **Dispensing Facilities** 180 gasoline dispensing facilities are permitted in Hamilton County. S tage 1 vapor recovery became a requirement in the county in 2005. Each dispensing facility receives an annual inspection. S tage 1 vapor recovery results in a reduction of fugitive aromatic compound emissions of toluene and xylenes of approximately 2 0 tons per ye ar. The use of Stage 1 vapor recover is a RACT level of emissions control. No additional reductions of aromatic compound emissions from gasoline dispensing facilities are practical. **4.3 On -** **Road Mobile Sources** Automobiles and light trucks registered in Hamilton County are subject to annual inspection and maintenance requirements of Tennessee State Rule 1200 - 3 - 29. This rule requires a successful vehicle inspection prior to registration renewal for 1975 model ye ar and newer vehicles. Inspection and maintenance of on- road mobile sources results in reductions in fugitive emissions of aromatic compounds, emissions of VOCs from incomplete combustion, and NO X emissions. The resulting reduction in emissions of aromatic compounds, such as toluene and xylenes, is approximately

2 0 tons per year. The existing inspecti on and maintenance program constitutes RACM for on-road mobile sources. No additional emissions reductions from on- road mobile sources are planned. Highway vehicles in Hamilton County emit 352 tons of ammonia per ye ar. Ammonia is produced by

vehicle cataly

tic converters, which are regulated at the federal level. The preamble of the PM 2.5 Implementation Rule states, “The NARSTO Fine Particulate Assessment indicates that reducing ammonia emissions where sulfates concentrations are high may reduce PM 2.5 mass concentrations, but may

also increase the acidity of particles and precipitation.” B ased on the high sulfates in this area and previous experience with acid rain, reductions of ammonia emissions are not practical. **4 .**  **4 Non**  **- Road and Stationary Internal**  **Combustion Engines** Non-road and stationary

internal combustion engines result in organic carbon and other primary particulate matter. This category o f engines includes a wide variety of non-road diesel engines without controls, railroad and barge diesel engines, two cycle engines where lubricating oil is mixed with gasoline, and numerous small gasoline engines. All of these engines are regulated at the federal level. H owever, state and local governments could institute voluntary p rograms to retrofit af ter market controls on existing non-road sources. A previous retrofit program had resulted in the installation of 105 diesel oxidation catalysts on local school buses. This program was completed in approximately three ye ars. About one ye ar was required to contract and install the catalysts. It is unlikely that another retrofit program generating sufficient reductions could be instituted in time to result in early attainment. Section 4 - 41, Rule 2 of the Ordinance limits industrial process NO X emissions to 300 ppm. Because many stationary internal combustion engines cannot meet this requirement, their use isC - HCAPCB - 50 - PM 2.5 SIP

limited. The Ordinance does allow for the use of stationary internal combustion engines to power emergency

g enerators. No emissions reductions beyond federal requirements for non road internal combustions engines are planned. **4.5 Open Burning** Open burning is regulated by S ection 4 - 41, Rule 6 of the Ordinance. This rule requires open burning permits, bans open burning from May 1 through September 30, and prohibits the burning of brush cleared for road building and trash in Hamilton County. In addition, open burning is only allowed within the City o f Chattanooga if no alternative is available. The City o f Chattanooga provides a brush pickup servi ce, and the collected brush is chipped. Existing restrictions constitute RACM for open burning and will remain in effect. **4.6 Home Heating with Wood** In formation from the 2000 US Census (Appendix 13 ) showed that 2.2 % of the households in twenty c ounties in and around the nonattainment area used wood as the primary heating fuel. Within Hamilton County, only 7 12 households, or 0.6 % of the total number, heat primarily with wood. Heating requirements are ty picall y designated in degree days. According to the American Gas Association, a degree day accrues for every

degree the average outside temperature is below 65 ° F during a 24 -hour period. June, July, August, and September require no heating in this area. InChattanooga, 3,384 degree days comprise the de sign heating requirements. This compares with design heating requirements of 6,282 degree days in Chicago and 7,966 degree days in Minneapolis. The Federal New Source Performance Standards for Residential Wood Heaters (40 CFR Part 60 Subpart AAA) applies to residential wood heaters manufactured after July 1, 1988, and sold after July 1 , 1990. In the last seventeen ye ars, it would be expected that a considerable portion of wood burning stoves have been replaced and that new stoves have been installed in new construction. Replacing remaining older stoves would result in some particulate matter and VOC emissions reductions. P articulate matter emission factors are 83 pounds per ton for conventional stoves and from 26.6 to 28 pounds per ton for stoves manufactured in accordance with Subpart AAA. VOC emission factors are 28 pounds per ton and 17.2 pounds per ton for conventional stoves and Subpart AAA compliant stoves, respectively. The small portion of households using wood heating, the mild local climate, and the normal purchases of Subpart AAA compliant wood burning stoves in the nonattainment area indicate that accelerated replacement of the remaining older stoves will not be able to advance the attainment date. No short term efforts to upgrade or further regulate home heating are planned.C - HCAPCB - 51 - PM 2.5 SIP

**5 .0 MOTOR VEHICLE EMISSIONS BUDGETS**  **5 .1 Transportation**  **Conformity** The purpose of transportation conformity is to ensure that Federal Transportation actions occurring in nonattainment and maintenance areas do not hinder the area from attaining and maintaining the NAAQS. This means that the level of emissions estimated for the Transportation Improvement Program and Long Range Transportation Plan must not exceed the motor vehicle emission budgets (MVEB) defined in thi s attainment demonstration. The MVEB for Hamilton County

w as developed through consultation with the Interagency C onsultation Partners and the Chattanooga Hamilton County North Georgia Transportation Planning Organization . G eorgia and Alabama are address ing transportation budgets for their portions of the nonattainment area. **5 .2 Transportation Budget for Hamilton County**  The budget was developed following the 2005 EPA Guidance for Creating On -Road Mobile Source Emission Inventories for PM 2.5 . Mobile source inventories were developed using the latest planning assumptions, the most recent recalibrated travel demand model, and EPA’s latest motor vehicle model, Mobile 6.2.03. Average annual activity and meteorology

was used in modeling. Planning Assumptio ns for Development of 2009 CHCNGA TPO TransCAD Model 2009 Emissions Results are contained in Appendix 1 4 . The transportation budget for PM 2.5 is 125.56 tons per year for Hamilton County. **5 .3 Pollutants**  **to B**  **e Considered 5**  **.3.1 Sulfur Dioxide (SO**  **2 )**  The PM 2.5 Implementation Rule provides that SO 2 must be addressed as a significant PM 2.5 precursor, and sources of SO 2 emissions must be evaluated for control measures. The rule further states that sulfur oxides are mostly emitted from fossil fuel combustion with a smaller portion of emissions from other industrial processes. According to the EPA, SO 2 emissions from motor vehicles would not require a budget due to the current de minimis levels of those emissions from on-road vehicles and further considering the projected decline in SO 2 emissions from vehicles due to low - sulfur gasoline and low - sulfur diesel fuel. H amilton County agrees with the EPA, and therefore no motor vehicle budget was developed for SO 2 on-road mobile sources. **5 .3**  **.2 Nitrogen Oxides (NO X** **)** The PM 2.5 Implementation Rule provides that NO X be addressed as a significant PM 2.5 precursor unless demonstrated otherwise by the State. The insignificance demonstration for NO X as a PM 2.5 precursor is found in Appendix 15. Modeling for seventy perc ent and one hundred percent reductions of NO X shows minimal changes in PM 2.5.C - HCAPCB - 52 - PM 2.5 SIP

**5 .3.3**  **Volatile Organic Compounds (VOCs)** The PM 2.5 Implementation Rule explains that the State is not required to address VOCs as a PM 2.5 attainment plan precursor unless the State or EPA provides an appropriate technical demonstration for a specific area showing that VOC emissions from sources in the State significantl y contribute to PM 2.5 concentrations in a given nonattainment area. No demonstration is being submitted. **5 .3.4**  **Ammonia** The EPA’s policy

on ammonia presumes that ammonia is not a PM 2.5 attainment plan precursor. The State is not required to address ammonia unless the State or EPA provides an appropriate technical demonstration showing that ammonia emissions from sources in the State significantl y contribute to PM 2.5 concentrations in the nonattainment area. No demonstration is being submitted. **5 .3.5**  **Road and Construction Dust** The PM 2.5 Implementation Rule states that crustal material is onl y a minor part of P M 2.5 annual average concentrations, and that construction dust will not be significant in all areas. Construction dust is not a significant concern in Hamilton County. The temperate climate and few unpaved roads in this primarily urban county

leave littl e opportunity

f or road or construction dust to become significant contributors to PM 2.5 . In addition, regular rainfall removes dust from paved roads and helps keep unpaved roads from becoming a source of significant PM 2.5 crustal material. No demonstrati on is being submitted.C - HCAPCB - 53 - PM 2.5 SIP

**6 .0**  **CONTINGENCY MEASURES** The PM 2.5 Implementation Rule requires contingency measures that would take effect in the event a nonattainment area fails to meet the PM2.5 NAAQS. These contingency m easures must be fully adopted rules or control measures that are ready to be implemented quickly u pon failure of an area to meet the standard b y the attainment date. There are no available contingency measures in Hamilton County that can result in significant PM 2.5 reductions from industrial sources as indicated by Table 4 - 1 in Section 4 . 1. 2 of this document . The table shows that elimination of all of the industrial emissions in the county will have little effect on the PM 2.5 concentration. Georgia Rules for Air Quality C ontrol 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. B owen 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 ye ar or 19,328 tons reduction in the last seven months of 2010. These reductions were not modeled for 2009. The reductions are not require d to demonstrate attainment of the annual PM 2.5 standard, but constitute contingency measures.C - HCAPCB - 54 - PM 2.5 SIP

**7 .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

b e 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 l inear 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 b y 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 p lan 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. C ompliance with the emission reduction measures in the attainment demonstration and State implementation p lan will meet the requirements for achieving reasonable further progress for the area.” C onsistent with the provisions of §51.1009(b), Hamilton County h as submitted a SIP that demonstrates that the Hamilton County p ortion of the nonattainment area will attain the annual PM 2.5 NAAQS within five years of designation. Therefore, no additional provisions for RFP are required. C ompliance with the emission reduction measures in this attainment demonstration and SIP will meet the requirements for achieving reasonable further pro gress for the Hamilton County, Tennessee area.