# Attachment Q NO X 

# Addendum

# Addendum to Attainment Demonstration

Knoxville, Tennessee PM 2.5 

# Nonattainment Area

(Anderson, Blount, Knox, Loudon, and Roane Counties)

Prepared by:

Tennessee Department of Envi ronment and Conservation Division of Air Pollution Control 9th Floor L&C Annex 401 Church Street Nashville, TN 37243i TABLE OF CONTENTS

Page List of Tables ii List of Figures ii List of Appendices ii

PREFACE ....................................................................................................................... .... 1

1.0 NO X EMISSION INVENTORIES .......................................................................... 2

2.0 NO X CONTROL MEASURES ................................................................................ 6

3.0 NO X RACT/RACM ANALYSIS .......................................................................... 10

4.0 WEIGHT OF EVIDENCE FOR NO X ................................................................... 18

5.0 CONTINGENCY MEASURES ............................................................................ 21

6.0 PROPOSED NO X MOTOR VEHICLE EMISSIONS BUDGET ......................... 24

LIST OF TABLES

Table 1- 1: 2002 NO X Emissions ....................................................................................... 2

Table 1- 2: 2002 NO X Emissions by Category (Actual Emissions Basis) ......................... 2

Table 1- 3: 2002 NO X Emissions by Category (Typical Emissions Basis) ....................... 3

Table 1- 4: Point Source Ca tegories with > 100 tons/year NO X Emissions, ..................... 3

Table 1- 5: 2009 NO X Emissions ....................................................................................... 4

Table 1- 6: 2009 NO X Emissions by Category .................................................................. 5

Table 1- 7: Proj ected Reduction in NO X Emissions, 2002-2009 ....................................... 5

Table 2- 1: NO X Emissions 2000-2006 (Acid Rain Program Data) 7

Table 2- 2: CAIR Annual NO X State Trading Budgets, Tennessee and Surrounding States ........................................................................................................................ ........... 9

Table 2- 3: CAIR NO X Controls at Tennessee Valley Authority EGUs ........................... 9

Table 3- 1: NO X Emissions from Coal-Fired Bo ilers (non-EGU, > 100 tons/year) 11

Table 3- 2: AP -42 List of NO X Control Options for Stoker Coal-Fired Boilers ............. 12ii Table 3- 3: NO X Emissions from Other Boilers (non-EGU, > 100 tons/year) ................ 13

Table 3- 4: NO X Control Options for Biomass Boilers (RBLC) ..................................... 13

Table 3- 5: NO X Emissions from Industrial Point Sources (> 100 Tons per Year) ......... 13

Table 3- 6: Tate & Lyle Emissions Reductions ............................................................... 14

Table 3- 7: RACT Analysis for Knox County Sources ................................................... 15

Table 4- 1: NO X Reductions by Category ....................................................................... 19

Table 4- 2: Summary of Weight of Evidence for NO X .................................................... 20

Table 5- 1: Continge ncy Requirements for SO 2 and NO X ............................................... 23

LIST OF FIGURES

Figure 2- 1: Tenne ssee and Regional NO X Emissions, 2000-2006 ................................... 7

Figure 2- 2: NO X Emissions at TVA Bull Run and Kingston, 2000-2006 ........................ 81 PREFACE

This document is an addendum to the PM 2.5 attainment demonstration and State Implementation Plan (PM 2.5 SIP) for the Knoxville, Tennessee PM 2.5 nonattainment area (Anderson, Blount, Knox, Loudon, and Roane Counties). The pr ehearing draft of the Knoxville-area PM 2.5 SIP includes a statement that emissions of nitrogen oxides (NO X ) from sources within the State do not contribute significantly to PM 2.5 nonattainment in the Knoxville area. This document includes additional NO X -related information on emission inventories, control measures, RACT/RACM, weight of evidence, and continge ncy measures. If Tennessee or U. S. EPA determines that NO X emissions contribute significantly to PM 2.5 nonattainment in the Knoxville area, the information contained in this document shall be incorporated into the Knoxville-area State Implementation Plan.2 1.0 NO X EMISSION INVENTORIES

NO X emission inventories were developed using th e same methods described in Section 4.0 of the PM 2.5 Attainment Demonstration for the Knoxville area. As indicated for SO 2 and direct PM 2.5 , a 2002 typical year inventory was developed for EGUs using the average heat inputs from 2000 to 2004. For the entire ASIP region, actual 2002 NO X emissions were about 0.1 percent lower than the typical year emissions. The di fferences on a State-by-St ate basis ranged from actual emissions being 9.6 percen t lower in Florida to 6.3 per cent higher in Mississippi. Tennessee’s 2002 actual NO X emissions from EGUs were 3.3% higher than typical year emissions.

NO X emissions inventories for the 2002 baseline year are summarized in Table 1- 1. As indicated previously for SO 2 and direct PM 2.5 , the 2002 baseline inventory in cludes inventories for actual and typical emissions. Countie s with the highest total NO X emissions were, in descending order: Knox, the nonattainment portion of Roane, Anderson, Loudon, and Blount.

Table 1- 1: 2002 NO X Emissions

County 2002 NO X Emissions (tons/year)

Area Nonroad Onroad Point (Actual Emissions) Point (Typical Emissions) Total (with Actual Point) Total (with Typical Point) Anderson 252 1,128 3,267 19,571 17,253 24,218 21,900 Blount 164 1,301 2,720 387 387 4,572 4,572 Knox 175 4,845 19,059 2,183 2,183 26,262 26,262 Loudon 57 1,231 4,273 2,309 2,309 7,869 7,869 Roane* 2 17 235 26,089 25,679 26,343 25,933 Totals 650 8,521 29,555 50,538 47,811 89,264 86,536 * Nonattainment portion only

The 2002 NO X emission inventory indicates that onroad mobile and point sources are responsible for most of the total NO X emitted in the nonattainment area (33.1% and 56.6%, respectively, Table 1- 2). On a c ounty-by-county basis, the fraction of NO X emissions from each category varies widely: 72.6% of NO X emissions in Knox County were emitted from onroad mobile sources, while point s ources were responsible for 80.8% of NO X in Anderson County. Use of typical emissions for the 2002 point source inventory does not significantly change the percentages (Table 1- 3).

Table 1- 2: 2002 NO X Emissions by Category (A ctual Emissions Basis)

County 2002 NO X Emissions, % of Totals Area Nonroad Onroad Point** Total** Anderson 1.0% 4.7% 13.5% 80.8% 100.0% Blount 3.6% 28.5% 59.5% 8.5% 100.0% Knox 0.7% 18.4% 72.6% 8.3% 100.0% Loudon 0.7% 15.6% 54.3% 29.3% 100.0%
Roane* 0.0% 0.1% 0.9% 99.0% 100.0% All Counties 0.7% 9.5% 33.1% 56.6% 100.0% * Nonattainment portion only. ** Actual emissions basis for poi nt sources and total emissions.3 Table 1- 3: 2002 NO X Emissions by Category (Typical Emissions Basis)

County 2002 NO X Emissions, % of Totals Area Nonroad Onroad Point** Total** Anderson 1.2% 5.2% 14.9% 78.8% 100.0% Blount 3.6% 28.5% 59.5% 8.5% 100.0% Knox 0.7% 18.4% 72.6% 8.3% 100.0% Loudon 0.7% 15.6% 54.3% 29.3% 100.0%
Roane* 0.0% 0.1% 0.9% 99.0% 100.0% All Counties 0.8% 9.8% 34.2% 55.2% 100.0% * Nonattainment portion only. ** Typical emissions basis for poi nt sources and total emissions.
Point sources with more than 100 tons per year of NO X emissions (actual emissions basis) are shown in Table 1- 4. These sources accounted for about 98% of point source emissions and 55.7% of the nonattainment area’s total NO X emissions in 2002 (actual emissions basis). TVA’s Bull Run and Kingston Fossil Plants were the largest point source emitters of NO X , with 87.1% of total point source emissions.

Table 1- 4: Point Source Categories with > 100 tons/year NO X Emissions, Sorted by Rank (2002 Ac tual Emissions Basis)

NAME SCC SCC Description NO X Emissions (tons/year) % of Total Point Source

Emissions Cumulative %

Roane 10100202 External Combustion Boilers - Electric Generation - Bituminous/Subbituminous Coal - Pulverized Coal: Dry Bottom (Bituminous Coal) 26,089 51.6% 51.6%

Anderson 10100212 External Combustion Boilers - Electric Generation - Bituminous/Subbituminous Coal - Pulverized Coal: Dry Bottom (Tangential) (Bituminous Coal) 17,909 35.4% 87.1%

Loudon 10200204 External Combustion Boilers - Industrial - Bituminous/Subbituminous Coal - Spreader Stoker 1,740 3.4% 90.5%

Knox 30500606 Industrial Processes - Mineral Products - Cement Manufacturing (Dry Process) - Kilns 1,529 3.0% 93.5%

Anderson 10200201 External Combustion Boilers - Industrial - Bituminous/Subbituminous Coal - Pulverized Coal: Wet Bottom 1,148 2.3% 95.8%

Knox 10300209 External Combustion Boilers - Commercial/Institutional - Bituminous/Subbituminous Coal - Spreader Stoker (Bituminous Coal) 375 0.7% 96.5%4 NAME SCC SCC Description NO X Emissions (tons/year) % of Total Point Source

Emissions Cumulative %

Loudon 30200768 Industrial Processes - Food and Agriculture - Grain Millings - Gluten Drying: Direct-fired Dryer - Produces Corn 232 0.5% 97.0%

Anderson 30999999 Industrial Processes - Fabricated Metal Products - Other Not Classified - Other Not Classified 204 0.4% 97.4%

Knox 30300908 Industrial Processes - Primary Metal Production - Steel Manufacturing (See 3-03-015 for Integrated I - Electric Arc Furnace: Carbon Steel (Stack) 163 0.3% 97.7%

Loudon 10200903 External Combustion Boilers - Industrial - Wood/Bark Waste - Wood-fired Boiler - Wet Wood (>=20% moisture) 109 0.2% 97.9%

Anderson 20100802 Internal Combustion Engines - Electric Generation - Landfill Gas - Reciprocating 107 0.2% 98.2%

Blount 30300105 Industrial Processes - Primary Metal Production - Aluminum Ore (Electro-reduction) - Anode Baking Furnace 101 0.2% 98.4% Grand Total (All Point Sources in Nonattainment Area) 50,538 100.0%

Projected NO X emissions inventories for 2009 are su mmarized in Table 1- 5. The 2009 emissions inventories assume that affected source s will install controls re quired to comply with existing Federal measures that become eff ective between 2002 and 2 009. Additional Statespecific measures were not assumed. Onroad mob ile sources will the largest fraction of total NO X emissions in 2009, relative to point source and total emissions, while point source emissions will decrease in relative importance (5 Table 1- 6 ).

Table 1- 5: 2009 NO X Emissions

County 2009 NO X Emissions (tons/year) Area Nonroad Onroad Point Total Anderson 259 921 2,168 3,178 6,525 Blount 168 1,149 1,964 421 3,702 Knox 208 4,377 11,042 2,204 17,831 Loudon 59 1,101 2,633 1,321 5,115 Roane* 2 16 137 3,238 3,393 Totals 696 7,563 17,945 10,362 36,567
* Nonattainment portion only6 Table 1- 6: 2009 NO X Emissions by Category

County 2009 NO X Emissions, % of Totals Area Nonroad Onroad Point Total Anderson 4.0% 14.1% 33.2% 48.7% 100.0% Blount 4.5% 31.0% 53.1% 11.4% 100.0% Knox 1.2% 24.5% 61.9% 12.4% 100.0% Loudon 1.1% 21.5% 51.5% 25.8% 100.0%
Roane** 0.1% 0.5% 4.0% 95.4% 100.0% All Counties 1.9% 20.7% 49.1% 28.3% 100.0%

Table 1- 7 shows the projected reduction in sulfur dioxide emissions between 2002 and 2009. Most of the reduction in point sour ce emissions results from the in stallation of controls at TVA’s Bull Run and Kingston Fossil Plants, as the facilities implement additional NO X reductions to comply with the Clean Air Inters tate Rule (see Section 5.0 of the SIP and Section 2.0 of this document for further discussion of this rule). Significant reductions are also achieved from the onroad and nonroad mobile source sector s, and the growth in area source NO X emissions is offset by reductions from other categories.

Table 1- 7: Project ed Reduction in NO X Emissions, 2002-2009

County 2002-2009 %Change in NO X Emissions Area Nonroad Onroad Point** All Categories Anderson 2.6% -18.4% -33.6% -83.8% -73.1% Blount 2.6% -11.7% -27.8% 8.9% -19.0% Knox 19.0% -9.7% -42.1% 1.0% -32.1% Loudon 3.2% -10.5% -38.4% -42.8% -35.0%
Roane* 4.0% -8.2% -41.6% -87.6% -87.1% All Counties 7.1% -11.2% -39.3% -79.5% -59.0% * Nonattainment portion only. ** 2002 actual emissions inventory used for point sources. % Change = (2009 Emissions - 2002 Emissions)/(2002 Emissions)7 2.0 NO X CONTROL MEASURES

Point Sources - Clean Air Interstate Rule 1

In a rulemaking action published in the Fe deral Register on May 12, 2005, EPA found that certain States must reduce emissions of SO 2 and/or NO X because those emissions contributed significantly to downwind areas in other St ates that are not meeting the annual PM 2.5 NAAQS or the 8-hour ozone NAAQS. The resulting Clean Air In terstate Rule (CAIR) required 28 States and the District of Columbia to revise their St ate Implementation Plans (SIPs) to reduce specified amounts of SO 2 and/or NO X emissions. The following paragraphs summarize trends in SO 2 emissions prior to the CAIR rulemaking, EPA’s a ssessment of the contri bution of interstate transport to PM 2.5 nonattainment, and the development of emissions budgets to reduce SO 2 emissions from EGUs.

Between 2000 and 2006, NO X emissions from electricity gene rating units (EGUs) decreased by about 883,000 tons (38.2% reduction based on 2000 emissions) in Tennessee and surrounding States 2 , 3 (Table 2- 1), while heat input from the same States grew by 2.7% during the same period 4 . The greatest reductions occurring be tween 2003 and 2005, as utilities reduced NO X emissions to comply with emission budgets under the NO X SIP Call (Figure 2- 1). A similar downward trend is observed for TVA’s Bull Run and Kingston Fossil Plants (Figure 2- 2). Emissions from Tennessee EGUs increased sl ightly between 2000 a nd 2001 and between 2005 and 2006, with declines in all other periods. Overall, NO X emissions from Tennessee utilities declined by 51,200 tons (32.8%) between 2000 and 2006.

Currently, the NO X SIP Call and Tennessee’s NO X Budget Trading Progr am require electric utilities and some other fuel-burning s ources to comply with a Statewide NO X budget during the summer ozone season only. Electric util ities are subject to some additional NO X control requirements under the Acid Rain Program. NO X Budgets established pur suant to the Clean Air Interstate Rule will become effective in 2009 and will require substantial additional NO X reductions.

1 Substantial portions of this section were taken from the Federal Register Notice: Rule to Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule); Revisi ons to Acid Rain Program; Revisions to the NO X SIP Call; Final Rule. Federal Register/Vol. 70, No. 91/Thursday, May 12, 2005/pp 25162 – 25405.

2 NO X emissions are presented for Alabama, Georgia, Illinois, Indian a, Kentucky, Louisiana, North Carolina, Ohio, South Carolina, Te nnessee, and West Virginia, for the reasons expl ained in Section 5.0 of the SIP.

3 All Acid Rain Program data presented in this section was obtained from U.S. EPA’s Clean Air Markets Data and Maps website ( http://camddataandmaps.epa.gov/gdm/ ).

4 See Section 5.0 of the SIP for a ta ble of EGU heat inputs by State.8 Table 2- 1: NO X Emissions 2000-2006 (Acid Rain Program Data)

State NO X Emissions in Tons 2000 2001 2002 2003 2004 2005 2006 Alabama 181,102 134,658 161,559 155,057 136,681 133,472 123,171 Georgia 184,552 162,378 146,456 104,433 100,654 111,365 112,143 Illinois 227,287 199,861 174,247 145,783 141,315 126,026 118,697 Indiana 334,522 315,420 281,146 260,980 224,311 207,982 202,728 Kentucky 246,632 232,272 198,599 185,071 164,101 165,563 171,787 Louisiana 98,590 81,288 80, 365 68,675 66,685 63,459 53,385 North Carolina 160,858 144,339 145,706 132,664 117,722 107,749 103,054 Ohio 375,155 334,206 370,497 355,063 266,792 254,452 238,587 South Carolina 87,775 81,623 82 ,900 77,391 65,126 51,235 48,342 Tennessee 156,010 156,365 155,996 134,356 109,782 101,442 104,810 West Virginia 259,229 205,137 225,371 203,142 172,339 159,481 151,673

Totals 2,311,709 2,047,546 2,022,842 1,822,617 1,565,509 1,482,225 1,428,376

80,000 100,000 120,000 140,000 160,000 180,000 200,000

1,000,000 1,250,000 1,500,000 1,750,000 2,000,000 2,250,000 2,500,000

2000 2001 2002 2003 2004 2005 2006Tennessee NOXEmissions (tons)Regional NOXEmissions (tons)

Regional Tennessee Regional NO X emissions include Alabama, Georgia, Illinois, Indiana, Kentucky, Louisiana, North Carolina, Ohio, South Carolina, Tennessee, and West Virginia

Figure 2- 1: Tennessee and Regional NO X Emissions, 2000-20069 Figure 2- 2: NO X Emissions at TVA Bull Run and Kingston, 2000-2006

PM 2.5 precursors may be transported for long distan ces, the collective contribution from multiple upwind States is a pr onounced feature of PM 2.5 nonattainment. EPA established 2009-2014 CAIR emission budgets for annual NO X emissions (10 Table 2- 2 ) by multiplying the fuel-adjusted heat input 5 of each individual State by 0.15 lb NO X /MMBtu. A second emission budget was es tablished for 2015 and beyond, based on the fuel-adjusted heat input and 0.125 lb NO X /MMBtu.

5 Fuel-adjusted heat inputs were used to better reflect actual NO X emissions for individual States in the CAIR region. EPA calculated fueladjusted heat inputs by multiplying a State’s historic heat input data for various fuel types (coal, fuel oil, natural gas, etc .) by different adjustment factors for each individual fuel. Additional info rmation on the calculation of heat inputs and NO X emissions budgets is available in the final CAIR rulemaking and supporting materials.11 Table 2- 2: CAIR Annual NO X State Trading Budgets, Tennessee and Surrounding States

State CAIR Annual NO X State Trading Budget for 2009- 2014 (tons) CAIR Annual NO X State Trading Budget for 2015 and thereafter (tons) 2009-2014 Budget, % Reduction from 2006 Emissions Alabama 69,020 57,517 44.0% Georgia 66,321 55,268 40.9% Illinois 76,230 63,525 35.8% Indiana 108,935 90,779 46.3% Kentucky 83,205 69,337 51.6% Louisiana 35,512 29,593 33.5% North Carolina 62,183 51,819 39.7% Ohio 108,667 90,556 54.5% South Carolina 32,662 27,219 32.4% Tennessee 50,973 42,478 51.4% West Virginia 74,220 61,850 51.1% Total 767,928 639,941 46.2% Tennessee and States found to contribute significantly to at leas t one nonattainment county in 201 0 base case, based on EPA CAI R air quality modeling results. CAIR NO X emission budgets are based on fuel-adjusted heat input and 0.15 lb NO X /MMBtu for 2009-2014 (0.125 lb NO X /MMBtu for 2015 and thereafter).

The Clean Air Interstate Rule does not mandate the use of any specific control technology, and affected sources may comply by installing contro ls or purchasing emi ssion allowances. The Tennessee Valley Authority currently operates existing NO X controls for Acid Rain Program and NO X Budget compliance (Table 2- 3), and these c ontrols will be available for CAIR compliance in 2009.

Table 2- 3: CAIR NO X Controls at Tennessee Valley Authority EGUs

Facility Name 2006 NO X Emissions

(tons) 2006 NO X Emission Rate

(lb/MMBtu) Existing NO X Controls Allen 13,265 0.47 SCR and overfire air Bull Run 8,352 0.37 SCR and boiler optimization Cumberland 34,360 0.37 SCR and low-NO X burners Gallatin 6,949 0.18 Low-NO X burners and overfire air John Sevier 9,690 0.39 Low-NO X burners and overfire air Johnsonville 18,156 0.41 Low-NO X burners and boiler optimization Kingston 13,953 0.26 SCR and low-NO X burners12 3.0 NO X RACT/RACM ANALYSIS

40 CFR 51 Subpart Z states that SIPs must include provisions fo r reasonably available control measures (RACM), reasonably available contro l technology (RACT), and reasonable further progress (RFP), as necessary to demonstrate attainme nt. States must demonstrate that they have adopted all reasonably available control measur es (including RACT fo r stationary sources) necessary to demonstrate attainment as exped itiously as practicable and to meet any RFP requirements. The SIP revision must contain the list of control meas ures considered by the State, and information and analysis sufficient to suppor t the State's judgment that it has adopted all RACM, including RACT. In determining whether sp ecific control measures must be adopted as RACM, States must consider the cumulative imp act of implementing the available measures. Potential measures that are reasonably availabl e considering technical and economic feasibility must be adopted as RACM if, considered collec tively, they would advan ce the attainment date by one year or more.

The PM 2.5 Implementation Rule provides additional guidance for the identification of appropriate RACT and RACM. The guidance states that a St ate must consider RACT and RACM for all of its nonattainment areas, but that if the State projects that an ar ea will attain the standard within five years of designation as a result of existi ng national measures, then the State may conduct a limited RACT and RACM analysis that does not involve additional air quality modeling. A limited analysis of this type would involve:

• Review of reasonably available measures;

• Estimation of potential emissions reductions; and

• Evaluation of the time needed to implement these measures.

If the State cannot achieve sign ificant emissions reduc tions during 2008, due to time needed to implement the potential measures or other relevant factors, then the State may conclude that there are no further reasonably available contro l measures that would advance the attainment date by one year or more.

To assist in the evaluation of various RA CT options, Tennessee re viewed the list of NO X point sources that were located within the nonattainme nt area. To narrow the range of RACT options, electric utilities were removed from the list 6 . NO X reductions from the following stationary sources were evaluated as potential RACT/RACM:

6 Electric utilities were removed from the list because significant NO X reductions are projected for the tw o coal-fired power plants in the nonattainment area, as follows (based on 2002 actual and 2009 ASIP emission inventories):

Facility 2002 NO X Emissions (tons) 2009 NO X Emissions (tons) % Reduction TVA Bull Run 17,909 2,078 88.4% TVA Kingston 26,089 3,238 87.6%

Tennessee’s CAIR NO X Annual Trading Program includes provisions that allow these f acilities to received surplus NO X allowances from Tennessee’s compliance supplement pool for NO X reductions achieved in 2007 and 2008. This measure allows for voluntary NOX reductions and could be considered as a voluntary RACT.13 1. Coal-fired boilers (non-EGU) with more than 100 tons/year of NO X emissions. 2. Other boilers (non-EGU) with more than 100 tons/year of NO X emissions. 3. Industrial point sour ces with more than 100 tons/year of NO X emissions. 4. Sources with less than 100 tons/year of NO X emissions.

NO X Reductions from non-EGU Coal-F ired Boilers (> 100 tons/year NO X ) : NO X emissions from stationary source coal combustion (non- EGU) are summarized in Table 3- 1. Total NO X emissions from these sources are 33.3% of projected 2009 NO X point source emissions. One of the three coal-fired boilers listed in Table 3- 1 (U. S. Department of En ergy Y-12) is scheduled to be replaced by 2009, and NO X emissions from the new boilers will be significantly lower 7

. NO X control options for the remaining coal-fired boilers are based upon the AP-42 list of NO X control technologies 8 and are listed in Table 3- 2. These options are rejected as potential RACT because it would not be possible to complete the required modifi cations in 2008 for most of the listed control options. The remaining option (load reduction) is likely to have a minimal effect on NO X emissions.

Table 3- 1: NO X Emissions from Coal-Fired Bo ilers (non-EGU, > 100 tons/year)

County SCC SCC Description 2009 NO X Emissions (tons)

Loudon 10200204 External Combustion Boilers - Industrial - Bituminous/Subbituminous Coal - Spreader Stoker 723

Anderson 10200201 External Combustion Boilers - Industrial - Bituminous/Subbituminous Coal - Pulverized Coal: Wet Bottom 557

Knox 10300209 External Combustion Boilers - Commercial/Institutional - Bituminous/Subbituminous Coal - Spreader Stoker (Bituminous Coal) 398
Total Emissions 1,678

7 The NO X emission limit for DOE’s natural gas-fi red replacement boilers is 81 tons/year.

8 See AP-42 emission factors, Chapter 1, Section 1.1 (Externa l Combustion Sources, Bituminous and Subbituminous Coal Combustion ), pages 14-15 for the full list of NO X control options for coal-fired boilers. This list was narro wed by selecting only the options that were listed as viable for stoker boilers.14 Table 3- 2: AP-42 List of NO X Control Options for Stok er Coal-Fired Boilers

Control Technique Description Potential NO X Reduction Comments

Load Reduction Reduction of coal and air Minimal Applicable to stokers that can reduce load without increasing excess air. May cause reduction in boiler efficiency. NO X reduction varies with % load reduction. Operational Modifications Rearrangement of air or fuel in the main combustion

zone 10-20% Low excess air only for stoker boilers. Must have sufficient operational flexibility to achieve NO X reduction without sacrificing boiler performance.

Overfire air Injection of air above main combustion zone 20-30% Must have su fficient furnace height above top row of burners in order to retrofit this technology to existing boilers. SNCR Injection of NH 3 or urea in the convective pass. 30-60% Applicable to new boilers or as retrofit technology; must have sufficient residence time at correct temperature (1750° F ± 90° F); elaborate reagent injection system; possible load restrictions on boiler; possible air preheater fouling by ammonium bisulfate.

NO X Reductions from Other Boilers (> 100 tons/year NO X ) : The inventory lists one wood-fired boiler (Kimberly Clark in Loudon, TN) w ith more than 100 tons/year of NO X emissions (15 Table 3- 3 ). Total NO X emissions from this sour ce are 2.4% of projected 2009 NO X point source emissions. A review of the Title V operating permit for this facility indicates that NO X emissions are limited to 52.5 pounds per hour and 230 tons per year (about 0.42 lb/MMBtu, based on 125.66 MMBtu/hr design heat input). The T itle V permit also indicates that this boiler is permitted to burn paper sludge. NO X control options for biomass-fi red boilers were not listed in AP-42, so RACT options were devel oped from the RACT-BACT-LAER Clearinghouse (RBLC) and are listed in Table 3- 4.

Table 3- 4 indicates that add-on contro ls are typically necessary to reduce NO X emissions below the range of 0.35 – 0.44 lb/MMBtu. These options are not feasible as RA CT, since it would be difficult to install add-on controls in less th an twelve months. The RBLC indicates that NO X emissions from two facilities are 0.2-0.22 lb/MMB tu. One of these sources burns a biomass other than wood, and is not cons idered as pote ntial RACT. NO X controls for the remaining source (RBLC ID: LA-0218) are listed as “g ood combustion practices, boiler design and operation.” The RBLC determin ation suggests that low NO X emissions for this source are a result of the boiler design, and redesign of the existing boiler woul d not be a feasible option for RACT.16 Table 3- 3: NO X Emissions from Other Boilers (non-EGU, > 100 tons/year)

County SCC SCC Description 2009 NO X Emissions (tons)

Loudon 10200903 External Combustion Boilers - Industrial - Wood/Bark Waste - Wood-fired Boiler - Wet W ood (>=20% moisture) 120

Table 3- 4: NO X Control Options for Biomass Boilers (RBLC)

Facility and RBLC ID RBLC ID Allowable NO X Emission Rate Controls Comments

Biomass Energy, LLC OH-0269 0.44 lb/MMBtu SCR Thermal Ventures VA-0268 0.4 lb/MMBtu Good combustion practice International Paper NC-0092 0.35 lb/MMBtu Good combustion practice Sierra Pacific Industries CA-0930 0.23 lb/MMBtu SNCR Boise Building Solutions LA-0218 0.22 lb/MMBtu Good combustion practice, boiler design and operation Draft determination

Archer Daniels Midland ND-0018 0.2 lb/MMBtu None listed Burns a biomass fuel other than wood. Virginia Dept. of Public Utilities MN-0058 0.15 lb/MMBtu SNCR Hibbing Public Utilities MN-0059 0.15 lb/MMBtu SNCR

NO X Reductions from Industrial Point Sources : Other industrial NO X sources with more than 100 tons per year of emissions are listed in Table 3- 5.

Table 3- 5: NO X Emissions from Industrial Point Sources (> 100 Tons per Year)

County SCC SCC Description 2009 NO X Emissions (tons)

Knox 30500606 Industrial Processes - Mineral Products - Cement Manufacturing (Dry Process) - Kilns 1,529

Loudon 30200768 Industrial Processes - Food and Agriculture - Grain Millings - Gluten Drying: Direct-fired Dryer - Produces Corn 247

Anderson 30999999 Industrial Processes - Fabricated Metal Products - Other Not Classified - Other Not Classified 222

Knox 30300908 Industrial Processes - Primary Metal Production - Steel Manufacturing (See 3-03-015 for Integrated I - Electric Arc Furnace: Carbon Steel (Stack) 156

Blount 30300105 Industrial Processes - Primary Metal Production - Aluminum Ore (Electro-reduction) - Anode Baking Furnace 113

Anderson 20100802 Internal Combustion Engines - Electric Generation - Landfill Gas - Reciprocating 104
Total Emissions 2,37117 Alcoa: NO X emissions from anode baking depend on operating practices and burner controls. The traditional methods of preventing NO X formation using staged combustion or low NO X burners are not applicable becaus e of the unique configuration of an anode baking ring furnace, with fuel injected at several points in narrow flues. Use of post-combustion controls (SCR or SNCR) is not feasible due to the relatively low temperature within the furnaces. However, advanced firing systems that precisely measure and regulate fuel flow using a computerized control system may reduce NO X emissions by reducing total fuel usage. Prevention of NO X formation using advanced firing co ntrol is technically feasible for anode baking, but retrofit of the existing firing system would probabl y require more than one year.

Tate and Lyle: No additional control measures were considered as RACT for this facility, since the facility is subject to an agreed order to reduce emissions , as indicated in Table 3- 6.

Table 3- 6: Tate & Ly le Emissions Reductions

Pollutant Allowable Emissions from Title V Operating Permit (tons/year) Post-Project Allowable Emissions (tons/year) PM/PM 10 466.8 305.2 Sulfur Dioxide 3,881 1,690 Nitrogen Oxides 1,733 932 Carbon Monoxide 450 392 Volatile Organic Compounds 694 335 Agreed order 04-0202 was issued August 10, 20 05, by the Tennessee Air Pollution Control Bo ard to resolve a citizens’ appeal of a construction permit issued for this facility (constructi on permit number 956292P, issued April 16, 2004). The facility is required to compl y with the postproject allowable emissions upon completion of the construction project expanding th e facility’s milling and alcohol finishing capacity. Startup of the expansion project occurred in October 2006.

Knox County Sources: A RACT analysis for Knox County s ources was prepared by the Knox County Department of Air Quality Management (Table 3- 7), which shows various control measures for the two Knox County sources listed in Table 3- 5. For Ameristeel, the listed options typically could not be implemented in 2008 and would not result in significant NO X reductions. These options are ther efore not suitable as RACT.

Most of the options listed for CEMEX are not su itable as RACT for the same reason. The use of low-NO X burners might be a feasible control option for CEMEX, but at least one year would be necessary to implement the required rule chan ge. CEMEX currently uses a mixture of tirederived fuel, mid-kiln fi ring, and SNCR to reduce NO X emissions, and NO X emissions from this facility are continuously monitored and recorded.18Table 3- 7: RACT Analysis for Knox County SourcesSource CategoryEmissions ReductionMeasureEstimatedControlEfficiencyTime toImplement(Months)Estimated Dateof CompletedActionEmissionReduction(tons/year)Cement Kilns- Cemex Biosolids injection 23% 12 1/16/2009 375Cement Kilns- Cemex Low NOXBurners 27-40% 6-12 7/16/2008 500Cement Kilns- Cemex Selective Catalytic Reduction 31-95% 12 1/16/2009 945Cement Kilns- Cemex SNCR-ammonia based 50% 12 1/16/2009 750Cement Kilns- Cemex SNCR-urea based 50% 12 1/16/2009 750Iron & Steel Mills - Annealing,Galvanizing, Reheating - Ameristeel Low NOXBurners 50-65% 6-12 1/16/2009 17Iron & Steel Mills - Annealing,Galvanizing, Reheating - AmeristeelLow NOXBurners + FlueGas Recirculation 60-77% 12 1/16/2009 20Iron & Steel Mills - Reheating -Ameristeel Low Excess Air 13% 12 1/16/2009 419 NO X RACT/RACM for Mobile Sources

The statutory RACM requirement can be found in Section 172(c)(1 ) of the Clean Air Act, which directs states to “provide for implementation of all reasonably available control measures as expeditiously as practicable.” The re gulatory RACT/RACM requirement for a PM 2.5 SIP revision can be found at 40 C.F.R. Section 51.1010:

(a) For each PM 2.5 nonattainment area, the State sh all submit with the attainment demonstration a SIP revision demonstrati ng that it has adopted all reasonably available control measures (including RACT for stationary sources) necessary to demonstrate attainment as expeditious ly as practicable and to meet any RFP requirements. The SIP revision shall cont ain the list of the potential measures considered by the State, and informati on and analysis sufficient to support the State's judgment that it has a dopted all RACM, including RACT.

(b) In determining whether a particular emission reduction measure or set of measures must be adopted as RACM under section 172(c)(1) of the Act, the State must consider the cumulative im pact of implementing the available measures. Potential measures that are reasonably available considering technical and economic feas ibility must be adopted as RACM if, considered collectively, they would advance the a ttainment date by one year or more.

NO X RACT/RACM Discussion for Mobile Sources

With regard to RACT/RACM evaluation on the nonroad and onroad mobile sectors, Tennessee believes that measures to reduce NO X from onroad and nonroad engi nes would not be achievable in a timely fashion to expedite attainment of the PM 2.5 NAAQS in the Knoxville PM 2.5 Nonattainment Area. Significant NO X reductions from these sectors are expected to result from existing Federal measures affecting both fuels a nd engines. In addition, an I/M program for onroad Heavy-Duty Diesel Vehi cles (HDDV) is not viable si nce a large proportion of HeavyDuty diesel trucks (tractor-tra iler type) travel through the Knoxv ille Region from other States. Tennessee is limited in its ability to affect an enforcement program on vehicles which are registered outside of the nonattainm ent area. A majority of the NO X emissions from HDDVs comes from those out-of-State trucks which w ould not be subject to a HDDV I/M program. For onroad Light-Duty vehicles, implementing an I/M program is not practical since the implementation of such a program would take at least a year. Reductions form a Light-Duty vehicle I/M program would not be realized until all applicable vehicles subject to the I/M program have been tested, which would take an additional year.

If implemented collectively, a ny group of potential RACM woul d need to provide sufficient reductions of NO X by 2009. The State has considered likel y control measures to determine if collectively they could meet these criteria. Se veral mandatory programs are available that can provide moderate levels of emi ssion reductions, but none of these measures can provide benefits by 2009, and the total overall reducti on that could be provided by th ese measures is likely below any threshold which could advance the attainment date by an entire year. While there are potential voluntary measures th at can be implemented before 2009, together these voluntary20 measures will not provide sufficient creditable emission reductions to advance the attainment date by one year. Therefore, there ar e no RACM appropriate for the Knoxville PM 2.5 Nonattainment Area. Further, existing measur es scheduled to be implementation by 2009 are expected to bring the region to attainment with the PM 2.5 NAAQS. As such, no further actions on RACT/RACM are warranted.21 4.0 WEIGHT OF EVIDENCE FOR NO X

Section 2.3 of EPA’s Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals For Ozone, PM 2.5 , and Regional Haze discusses basic requirements for weight of evidence analyses. This guidance states that St ates should review the results of the modeled attainment test and of seve ral different types of air quality analyses. Each analysis should be weighed according to its credib ility and its ability to assess the adequacy of the proposed attainment strategy, and the conclu sions should be combined into an overall assessment of whether the area is likely to meet the air quality goals. For areas in which the predicted future design values are greater than 14.5 μg/m 3 at one or more monitoring sites, the guidance states that a weight of evidence de monstration should be conducted to determine whether the aggregate supplemental analyses suppor t the modeled attainment test. As indicated in Section 8.0 of the PM 2.5 SIP, the predicted future design va lue at one monitor in the Knoxville nonattainment area is greater than 14.5 μg/m 3 , and Tennessee is conducting a weight of evidence analysis in support of the modeled attainment test.

EPA’s modeling guidance states that each analysis in a weight of evidence argument must be weighted qualitatively, depending upon: 1) the cap acity of the analysis to address the adequacy of a control strategy; and 2) the technical credibility of the analysis. If the overall weight of evidence produced by the combination of the primary modeling analysis and the various supplemental analyses supports the attainment hypothesis, then attainment of the NAAQS is demonstrated with the proposed strategy.

The end product of a weight of evidence determina tion is a document that describes the analyses performed, databases used, key assumptions and outcomes of each analysis, and why a State/Tribe believes that the eviden ce, viewed as a whole, supports a conclusion that the area will attain the NAAQS. This section provides additional NO X -related weight of evidence information for the PM 2.5 SIP.

The weight of evidence analysis for the Knoxv ille area is summarized in Table 4- 2, with additional supporting comments in the following paragraphs.

Emissions Inventory: Changes in Direct PM 2.5 and Precursor Emissions

The Knoxville-area emission inventory was revi ewed to determine wh ether the predicted emission reductions are: 1) significant (i. e., ar e the reductions a sizeable fraction of the total emissions inventory); and 2) likely to occur by 2009.

NO X emissions from all sources in the nonattai nment area will decline by 59% between 2002 and 2009 (see Table 1- 7). The most significant reductions will occur at point sources in Anderson and Roane County (39,244 tons, Tabl e 4- 1), as electric utilit ies begin year-round operation of existing NO X controls to comply with the provisions of the Clean Air Interstate Rule. Point source reductions from these countie s account for about 74% of total NO X reductions between 2002 and 2009. These reductions are considered hi ghly likely to occur, si nce they are required for compliance with Federal re gulations, and since existing NO X control equipment will be used for compliance.22 Table 4- 1: NO X Reductions by Category

County 2002-2009 Change in NO X Emissions (tons/year)

Area Nonroad Onroad Point** Total Anderson 7 -207 -1,099 -16,393 -17,693
Blount 4 -152 -756 34 -870 Knox 33 -468 -8,017 21 -8,431 Loudon 2 -130 -1,640 -988 -2,754 Roane* 0 -1 -98 -22,851 -22,950 Totals 46 -958 -11,610 -40,176 -52,697 * Nonattainment portion only. ** 2002 actual emissions inventory used for point sources. Change = 2009 Emissions - 2002 Emissions

Table 4- 1 also indicates si gnificant (22% of total) NO X reductions from onroad mobile sources. These reductions will occur as more strict emission requirements are implemented for motor vehicles. However, the timing of these redu ctions depends upon the turnover rates of the existing fleet of motor vehicles, and thes e reductions are given less weight than contemporaneous reductions from electric utilities.23Table 4- 2: Summary ofWeight of Evidence for NOXAnalysisData SourceKey Assumptions andOutcomesQualitative WeightingSupports Attainment in2009?Point Source NOXReductionsVISTAS/ASIP BaseG/G2 EmissionInventorySignificant NOXreductions fromelectric utilities by 2009.High weighting – reductions arerequired by Federal rules andutilize existing controlequipment. Yes.Onroad Mobile Source NOXReductionsVISTAS/ASIP BaseG/G2 EmissionInventorySignificant NOXreductions by2009, but of lesser magnitudethan projected utility reductions.Medium to high weighting –Federal regulations require lowerNOXemissions from onroadmobile sources, but timing of thereductions is dependent uponfleet turnover rate. Yes.Other NOXreductionsVISTAS/ASIP BaseG/G2 EmissionInventory and facilityconstruction permitapplication.Slight increase in area sourceemissions is offset by modestdecrease from nonroad mobilesources.Low weighting – emissionschanges from area sources andnonroad mobile sources aremodest compared to onroad andpoint source reductions. Yes. Slight positive impact.24 5.0 CONTINGENCY MEASURES

Consistent with section 172(c)(9) of the Act and 40 CFR §51.1012, the State must submit in each attainment plan specific contingency measures to be undertaken if the area fails to make reasonable further progress, or fails to attain the PM 2.5 NAAQS by its attainment date. As discussed in the preamble to the PM 2.5 implementation rule, the key re quirements associated with contingency measures are:

• Contingency measures must be fully adopted ru les or control measures that are ready to be implemented quickly upon failure to meet RFP or failure of the area to meet the standard by its attainment date.

• The SIP should contain trigger mechanisms for the contingency measures, specify a schedule for implementation, and indicate that the measures will be implemented without further action by the State or by EPA.

• The contingency measures should consist of ot her control measures for the area that are not included in the control strategy for the SIP.

• The measures should provide for emission redu ctions equivalent to about one year of reductions needed for RFP, based on the ove rall level of reductions needed to demonstrate attainment divided by the number of years from the 2002 base year to the attainment year.

Contingency measures are those m easures that would not be incl uded in the attainment strategy for various reasons; for example, they may not be as economically feasible as other measures that are considered to be RACM, or it may not be possible to implement the measures soon enough to advance the attainment date (e.g. fe deral mobile source measures based on the incremental turnover of the motor vehicle fleet each year).

Tennessee has elected to use a portion of the SO 2 emission reductions obtai ned pursuant to the Clean Air Interstate Rule (40 CFR 96 S ubparts AAA through III and TAPCR 1200-3-14-.04) to comply with the contingency plan requirements of the PM 2.5 Implementation Rule. Specifically, Tennessee will use the reductions at Units 1 th rough 4 of Tennessee Valley Authority’s Kingston Fossil Plant to comply with th e contingency plan requirements 9

.

• The CAIR rules were adopted by Tennessee a nd filed with the Secretary of State on August 10, 2006. Tennessee’s request to inco rporate this rule into the State Implementation Plan 10 is pending, and the CAIR Federal Implementation Plan (40 CFR 97 Subparts AAA through III) and abbreviated SIP provisions until the full SIP is

9 TVA’s Bull Run Fossil Plant is also located within the nonattainment area. However, Tennessee is not claiming the reductions at Bull Run as a contingency measure. Construction of the wet scrubber at Bull R un is projected to be complete by the end of 2008, and the scru bber is projected to be operational throughout 2009. The AS IP attainment modeling for the Knoxville nona ttainment area assumed that the scrubber at Bull Run would be operational. Since Tennessee used Bull Run’s projected reductions to demons trate attainment in 2009, the State may no t use the same reductions as a contingency measure. The situation for TVA’ s Kingston Fossil Plant is different, as explained below.

10 Tennessee requested adoption of the CAIR ru les into the SIP on September 8, 2006.25 approved. Tennessee has fully adopted the CAIR rules 11 and implementation of the rules is currently underway. The emission reduc tions required by CAIR will occur without further action by the State.

• The Implementation Rule states that the SIP should contain trigger mechanisms for the contingency measures, specify a schedule for implementation, and indicate that the measures will be implemented without furthe r action by the State or by EPA. For the SO 2 reductions at TVA Kingston, th e requirement to include a trigger mechanism does not apply, since the emission reductions will occur regardless of the attainment status in 2009.

• The attainment modeling for Knoxville indicated that the PM 2.5 design value for 2009 would attain the NAAQS, but th is modeling assumed that we t scrubber controls for the Kingston facility would not be in place during the attainment year. The SO 2 reductions at Kingston comply with the requirement that c ontingency measures should consist of other control measures for the area that are not incl uded in the control strategy for the SIP.

• The emission reductions in the contingency pl an provide for greater than one year of reductions needed for RFP, based on the ove rall level of reductions needed to demonstrate attainment divided by the number of years from the 2002 base year to the attainment year. The proposed contingency measures will exceed this requirement by an ample margin, as indicated in Table 5- 1.

• Table 5- 1 shows that the SO 2 reductions from the proposed contingency measure are sufficient to account for one year of SO 2 reductions between 2002 and 2009, plus one year of NO X reductions over the same period. This approach conservatively assumes that one ton of SO 2 reductions will have the same impact on ambient PM 2.5 concentrations as one ton of NO X reductions. 12

• Direct PM 2.5 emissions will increase by 66 tons/year between 2002 and 2009, based on the 2002 actual emission inventory. Because the air quality modeling demonstrates attainment with no reduction in direct PM 2.5 emissions, no contingency measures are proposed for this pollutant.

11 With some revisions pending.

12 Tennessee believes that, for the reasons outlined in the SIP, NO X emissions do not significantly impact ambient PM 2.5 concentrations in the Knoxville area, and that the positive impact of one ton of SO 2 reductions will actually be far greater than the impact of equivalent NO X reductions. The contingency plan conser vatively assumes that, if additional SO 2 reductions are to be used in lieu of NO X reductions, one ton of additional SO 2 reduction must be obtained to substitute for each ton of NO X reductions.26 Table 5- 1: Contingency Requirements for SO 2 and NO X

Actual SO 2 emissions from all source categories (area, nonroad, onroad, and point sources) in 2002 baseline year 134,218 tons

Projected SO 2 emissions from all source categories (area, nonroad, onroad, and point sources) in 2009 attainment year 93,155 tons

SO 2 reductions required from proposed contingency measures 5,866 tons 13
Actual NO X emissions from all source categories (area, nonroad, onroad, and point sources) in 2002 baseline year 89,264 tons

Projected NO X emissions from all source categories (area, nonroad, onroad, and point sources) in 2009 attainment year 36,567 tons

NO X reductions required from proposed contingency measures 7,528 tons 14 Total emission reductions (SO 2 plus NO X ) required from proposed contingency measures 13,394 tons 15

Projected SO 2 reductions from TVA Kingst on Units 6-9 after scrubber installation 30,224 tons 16

Tennessee notes that the SO 2 emission reductions relied upon for contingency planning will be of greater magnitude than SO 2 , NO X , or direct PM 2.5 emission reductions that could be obtained from any other source category. Tennessee also notes that these reductions will be achieved more quickly than reductions from other source categories, since contingency rulemaking would need to allow a schedule of three years or mo re for implementation of equivalent measures (assuming that such equivalent reductions could be obtained from other sources).

13 (134,893 tons – 93,852 tons)/(7 years) = 5,863 tons
14 (89,264 tons – 36,567 tons)/(7 years) = 7,528 tons

15 5,863 tons + 7,528 tons = 13,394 tons
16 Projected SO 2 reductions from Units 6-9 of TVA’s Kingston Fossil Plant we re calculated from the ASIP emission inventories by (1) comparing 2002 actual emissions and 2009 emi ssions from TVA’s Bull Run Fossil Plant; (2) estimating a control efficiency for TV A Bull Run based on 2002 and 2009 emissions; (3) assuming the same control e fficiency for TVA Kingston Units 6-9 upon installation and sta rtup of the scrubber (TVA’s Kingston and Bull Run Fossil Plants will have th e same control equipment); and (4) using the TVA Kingston’s 200 2 actual emissions and the assumed control efficiency to project the 2009 emissions for Units 6-9. The results are summarized in the fo llowing table:

Actual SO 2 Emissions for TVA Bull Run in 2002 (tons) 36,729 Projected SO 2 Emissions for TVA Bull Run in 2009 (tons) 8,657 Projected SO 2 Control Efficiency for TVA Bull Run in 2009 76.4% Actual SO 2 Emissions for TVA Kingston in 2002 (tons) 76,055 Heat Input for TVA Kingston (Units 1-9) 106,727,181 Heat Input for TVA Kingston (Units 6-9) 54,427,415 2002 Heat Inputs for Units 6-9, % of Total 51.0% Estimated Actual 2002 SO 2 Emissions for TVA Kingston Units 6-9 (tons) 39,559 Projected SO 2 Control Efficiency for TVA Kingston (based on TVA Bull Run) 76.4% Projected SO 2 Emissions for TVA Kingston After Scrubber Installation (tons) 9,335 Projected SO 2 Reduction for TVA Kingston Units 6-9 After Scrubber Installation (tons) 30,22427 6.0 NO X MOTOR VEHICLE EMISSIONS BUDGET

Tennessee believes that NO X emissions from all anthropoge nic sources do not significantly contribute to PM 2.5 nonattainment in the Knoxville area. If EPA does not ag ree with this demonstration, the following Motor Vehicle Emi ssion Budget (MVEB) is proposed for use in transportation conformity determinations. Tennessee is seeking public comment on both alternatives: a Motor Vehicle Emis sion Budget (MVEB) for direct PM 2.5 only, or alternatively, MVEBs for both direct PM 2.5 and for NO X , as outlined below. Tennessee will include one or both MVEB’s in the SIP after cons idering EPA and public comments.

NO X Motor Vehicle Emissions Budget

The NO X MVEB was developed in the same manner, with the same assumptions, (temperature, humidity, etc.) as the PM 2.5 budget; all assumptions and information used in developing the following NO X budget are the same as those used in developing the PM 2.5 budget. As part of the consultation process on setting MVEBs, the c onsultation partners di scussed the geographic extent of the MVEB. It was decided through In teragency Consultation (IAC) that a regional emissions budget would be the most appropria te for the Knoxville nonattainment area.

The mobile inputs used to develop the attainme nt demonstration modeling as well as the MVEB were developed through interagenc y consultation with the transportation partners for this area. Emissions developed through the attainment demons tration modeling were us ed in evaluating the various precursors, since precursor informa tion was available and extensive modeling and sensitivity analysis was conducted on this i nventory. The MVEB is developed from modeling conducted by the Knoxville Transportation Pla nning Organization (TPO) so that the MVEB development is as consistent as possible with th e methods used to determine conformity. Note, however, the Onroad Mobile emissions estimate s from the attainment demonstration do not exactly match those numbers used to develop the MVEB which comes from the TPO's most recent conformity determination. The treatment of the emissions by the photochemical model, and the way emissions are developed through the di fferent models, inherent ly leads to different results. These small differences are a product of the different modeling approaches, and do not hinder timely attainment of the NAAQS.

Pursuant to EPA’s transporta tion conformity rule in 40 CFR 93, specific emission budgets are hereby defined for the onroad mobile sources po rtion of the emissions inventory. The MVEB, for transportation conformity purposes for the Knoxville PM 2.5 nonattainment area for 2009 is contained in Table 6- 1. This budget is to be used by the transportation aut horities to assure that transportation plans, programs, and projects are consistent with, and conform to, the attainment and maintenance of acceptable ai r quality in the Knoxville area. This MVEB applies to the entire Knoxville PM 2.5 nonattainment area, including the don ut area contained in Roane County.

Table 6- 1: NO X MVEB for 2009

Pollutant: 2009 MVEB (tons/year) NO X 18,024.9