Attachment Q 

NOX Addendum 
Addendum to 

Attainment Demonstration 

Knoxville, Tennessee 

PM2.5 Nonattainment Area 

(Anderson, Blount, Knox, Loudon, and Roane 

Counties) 

Prepared by: 

Tennessee Department of Environment and Conservation 

Division of Air Pollution Control 

9th Floor L&C Annex 

401 Church Street 

Nashville, TN 37243
i 

TABLE OF CONTENTS 

 Page

 List of Tables ii

 List of Figures ii

 List of Appendices ii

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

1.0 NOX EMISSION INVENTORIES .......................................................................... 2

2.0 NOX CONTROL MEASURES ................................................................................ 6

3.0 NOX RACT/RACM ANALYSIS .......................................................................... 10

4.0 WEIGHT OF EVIDENCE FOR NOX ................................................................... 18

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

6.0 PROPOSED NOX MOTOR VEHICLE EMISSIONS BUDGET ......................... 24

LIST OF TABLES 

Table 1- 1: 2002 NOX Emissions ....................................................................................... 2 

Table 1- 2: 2002 NOX Emissions by Category (Actual Emissions Basis) ......................... 2 

Table 1- 3: 2002 NOX Emissions by Category (Typical Emissions Basis) ....................... 3 

Table 1- 4: Point Source Categories with > 100 tons/year NOX Emissions, ..................... 3 

Table 1- 5: 2009 NOX Emissions ....................................................................................... 4 

Table 1- 6: 2009 NOX Emissions by Category .................................................................. 5 

Table 1- 7: Projected Reduction in NOX Emissions, 2002-2009 ....................................... 5 

Table 2- 1: NOX Emissions 2000-2006 (Acid Rain Program Data) 7 

Table 2- 2: CAIR Annual NOX State Trading Budgets, Tennessee and Surrounding 

States ................................................................................................................................... 9 

Table 2- 3: CAIR NOX Controls at Tennessee Valley Authority EGUs ........................... 9 

Table 3- 1: NOX Emissions from Coal-Fired Boilers (non-EGU, > 100 tons/year) 11 

Table 3- 2: AP-42 List of NOX Control Options for Stoker Coal-Fired Boilers ............. 12 
ii 

Table 3- 3: NOX Emissions from Other Boilers (non-EGU, > 100 tons/year) ................ 13 

Table 3- 4: NOX Control Options for Biomass Boilers (RBLC) ..................................... 13 

Table 3- 5: NOX 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: NOX Reductions by Category ....................................................................... 19

Table 4- 2: Summary of Weight of Evidence for NOX .................................................... 20

Table 5- 1: Contingency Requirements for SO2 and NOX ............................................... 23

LIST OF FIGURES 

Figure 2- 1: Tennessee and Regional NOX Emissions, 2000-2006 ................................... 7

Figure 2- 2: NOX Emissions at TVA Bull Run and Kingston, 2000-2006 ........................ 8
1 

PREFACE 

This document is an addendum to the PM2.5 attainment demonstration and State Implementation 

Plan (PM2.5 SIP) for the Knoxville, Tennessee PM2.5 nonattainment area (Anderson, Blount, 

Knox, Loudon, and Roane Counties). The prehearing draft of the Knoxville-area PM2.5 SIP 

includes a statement that emissions of nitrogen oxides (NOX) from sources within the State do 

not contribute significantly to PM2.5 nonattainment in the Knoxville area. This document 

includes additional NOX-related information on emission inventories, control measures, 

RACT/RACM, weight of evidence, and contingency measures. If Tennessee or U. S. EPA 

determines that NOX emissions contribute significantly to PM2.5 nonattainment in the Knoxville 

area, the information contained in this document shall be incorporated into the Knoxville-area 

State Implementation Plan. 
2 

1.0 NOX EMISSION INVENTORIES 

NOX emission inventories were developed using the same methods described in Section 4.0 of 

the PM2.5 Attainment Demonstration for the Knoxville area. As indicated for SO2 and direct 

PM2.5, 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 NOX emissions were about 0.1 percent 

lower than the typical year emissions. The differences on a State-by-State basis ranged from 

actual emissions being 9.6 percent lower in Florida to 6.3 percent higher in Mississippi. 

Tennessee’s 2002 actual NOX emissions from EGUs were 3.3% higher than typical year 

emissions. 

NOX emissions inventories for the 2002 baseline year are summarized in Table 1- 1. As indicated 

previously for SO2 and direct PM2.5, the 2002 baseline inventory includes inventories for actual 

and typical emissions. Counties with the highest total NOX emissions were, in descending order: 

Knox, the nonattainment portion of Roane, Anderson, Loudon, and Blount. 

Table 1- 1: 2002 NOX Emissions 

County 

2002 NOX 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 NOX emission inventory indicates that onroad mobile and point sources are 

responsible for most of the total NOX emitted in the nonattainment area (33.1% and 56.6%, 

respectively, Table 1- 2). On a county-by-county basis, the fraction of NOX emissions from 

each category varies widely: 72.6% of NOX emissions in Knox County were emitted from 

onroad mobile sources, while point sources were responsible for 80.8% of NOX 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 NOX Emissions by Category (Actual Emissions Basis) 

County 

2002 NOX 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 point sources and total emissions. 
3 

Table 1- 3: 2002 NOX Emissions by Category (Typical Emissions Basis) 

County 

2002 NOX 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 point sources and total emissions. 

Point sources with more than 100 tons per year of NOX 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 NOX emissions in 2002 (actual emissions basis). TVA’s 

Bull Run and Kingston Fossil Plants were the largest point source emitters of NOX, with 87.1% 

of total point source emissions. 

Table 1- 4: Point Source Categories with > 100 tons/year NOX Emissions, 

Sorted by Rank (2002 Actual Emissions Basis) 

NAME SCC SCC Description 

NOX 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 

NOX 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 NOX emissions inventories for 2009 are summarized in Table 1- 5. The 2009 

emissions inventories assume that affected sources will install controls required to comply with 

existing Federal measures that become effective between 2002 and 2009. Additional Statespecific measures were not assumed. Onroad mobile sources will the largest fraction of total 

NOX 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 NOX Emissions 

County 

2009 NOX 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 only
6 

Table 1- 6: 2009 NOX Emissions by Category 

County 

2009 NOX 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 source emissions results from the installation of controls at TVA’s 

Bull Run and Kingston Fossil Plants, as the facilities implement additional NOX reductions to 

comply with the Clean Air Interstate 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 sectors, and the growth in area source NOX emissions is 

offset by reductions from other categories. 

Table 1- 7: Projected Reduction in NOX Emissions, 2002-2009 

County 

2002-2009 %Change in NOX 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 NOX CONTROL MEASURES 

Point Sources - Clean Air Interstate Rule1

In a rulemaking action published in the Federal Register on May 12, 2005, EPA found that 

certain States must reduce emissions of SO2 and/or NOX because those emissions contributed 

significantly to downwind areas in other States that are not meeting the annual PM2.5 NAAQS or 

the 8-hour ozone NAAQS. The resulting Clean Air Interstate Rule (CAIR) required 28 States 

and the District of Columbia to revise their State Implementation Plans (SIPs) to reduce specified 

amounts of SO2 and/or NOX emissions. The following paragraphs summarize trends in SO2

emissions prior to the CAIR rulemaking, EPA’s assessment of the contribution of interstate 

transport to PM2.5 nonattainment, and the development of emissions budgets to reduce SO2

emissions from EGUs. 

Between 2000 and 2006, NOX emissions from electricity generating units (EGUs) decreased by 

about 883,000 tons (38.2% reduction based on 2000 emissions) in Tennessee and surrounding 

States2,3 (Table 2- 1), while heat input from the same States grew by 2.7% during the same 

period4. The greatest reductions occurring between 2003 and 2005, as utilities reduced NOX

emissions to comply with emission budgets under the NOX 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 slightly between 2000 and 2001 and between 2005 

and 2006, with declines in all other periods. Overall, NOX emissions from Tennessee utilities 

declined by 51,200 tons (32.8%) between 2000 and 2006. 

Currently, the NOX SIP Call and Tennessee’s NOX Budget Trading Program require electric 

utilities and some other fuel-burning sources to comply with a Statewide NOX budget during the 

summer ozone season only. Electric utilities are subject to some additional NOX control 

requirements under the Acid Rain Program. NOX Budgets established pursuant to the Clean Air 

Interstate Rule will become effective in 2009 and will require substantial additional NOX

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); Revisions to Acid Rain Program; Revisions to the NOX SIP Call; Final Rule. Federal 

Register/Vol. 70, No. 91/Thursday, May 12, 2005/pp 25162 – 25405. 

2 NOX emissions are presented for Alabama, Georgia, Illinois, Indiana, Kentucky, Louisiana, North Carolina, Ohio, South Carolina, Tennessee, 

and West Virginia, for the reasons explained 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 table of EGU heat inputs by State. 
8 

Table 2- 1: NOX Emissions 2000-2006 (Acid Rain Program Data) 

 

State

NOX 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 2006

Tennessee NOX Emissions (tons)

Regional NOX Emissions (tons)

Regional Tennessee

Regional NOX emissions include Alabama, Georgia, 

Illinois, Indiana, Kentucky, Louisiana, North Carolina, 

Ohio, South Carolina, Tennessee, and West Virginia

Figure 2- 1: Tennessee and Regional NOX Emissions, 2000-2006 
9 

Figure 2- 2: NOX Emissions at TVA Bull Run and Kingston, 2000-2006 

PM2.5 precursors may be transported for long distances, the collective contribution from multiple 

upwind States is a pronounced feature of PM2.5 nonattainment. EPA established 2009-2014 

CAIR emission budgets for annual NOX emissions (
10 

Table 2- 2) by multiplying the fuel-adjusted heat input5 of each individual State by 0.15 lb 

NOX/MMBtu. A second emission budget was established for 2015 and beyond, based on the 

fuel-adjusted heat input and 0.125 lb NOX/MMBtu. 

 

5 Fuel-adjusted heat inputs were used to better reflect actual NOX 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 information on the calculation of heat inputs and NOX emissions budgets is available in the final 

CAIR rulemaking and supporting materials. 
11 

Table 2- 2: CAIR Annual NOX State Trading Budgets, Tennessee and Surrounding States 

 State 

CAIR Annual NOX State 

Trading Budget for 2009-

2014 (tons) 

CAIR Annual NOX

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 least one nonattainment county in 2010 base case, based on EPA CAIR air quality 

modeling results. CAIR NOX emission budgets are based on fuel-adjusted heat input and 0.15 lb NOX/MMBtu for 2009-2014 (0.125 lb 

NOX/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 controls or purchasing emission allowances. The 

Tennessee Valley Authority currently operates existing NOX controls for Acid Rain Program and 

NOX Budget compliance (Table 2- 3), and these controls will be available for CAIR compliance 

in 2009. 

Table 2- 3: CAIR NOX Controls at Tennessee Valley Authority EGUs 

Facility Name 

2006 NOX

Emissions 

(tons) 

2006 NOX

Emission Rate 

(lb/MMBtu) Existing NOX 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-NOX burners 

Gallatin 6,949 0.18 Low-NOX burners and overfire air 

John Sevier 9,690 0.39 Low-NOX burners and overfire air 

Johnsonville 18,156 0.41 Low-NOX burners and boiler optimization 

Kingston 13,953 0.26 SCR and low-NOX burners 
12 

3.0 NOX RACT/RACM ANALYSIS 

40 CFR 51 Subpart Z states that SIPs must include provisions for reasonably available control 

measures (RACM), reasonably available control technology (RACT), and reasonable further 

progress (RFP), as necessary to demonstrate attainment. States must demonstrate that they have 

adopted all reasonably available control measures (including RACT for stationary sources) 

necessary to demonstrate attainment as expeditiously as practicable and to meet any RFP 

requirements. The SIP revision must contain the list of control measures considered by the State, 

and information and analysis sufficient to support the State's judgment that it has adopted all 

RACM, including RACT. In determining whether specific control measures must be adopted as 

RACM, States must consider the cumulative impact of implementing the available measures. 

Potential measures that are reasonably available considering technical and economic feasibility 

must be adopted as RACM if, considered collectively, they would advance the attainment date 

by one year or more. 

The PM2.5 Implementation Rule provides additional guidance for the identification of appropriate 

RACT and RACM. The guidance states that a State must consider RACT and RACM for all of 

its nonattainment areas, but that if the State projects that an area will attain the standard within 

five years of designation as a result of existing 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 significant emissions reductions 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 control measures that would advance the attainment 

date by one year or more. 

To assist in the evaluation of various RACT options, Tennessee reviewed the list of NOX point 

sources that were located within the nonattainment area. To narrow the range of RACT options, 

electric utilities were removed from the list6

. NOX reductions from the following stationary 

sources were evaluated as potential RACT/RACM: 

 

6 Electric utilities were removed from the list because significant NOX reductions are projected for the two coal-fired power plants in the 

nonattainment area, as follows (based on 2002 actual and 2009 ASIP emission inventories): 

Facility 

2002 NOX Emissions 

(tons) 

2009 NOX Emissions 

(tons) % Reduction 

TVA Bull Run 17,909 2,078 88.4% 

TVA Kingston 26,089 3,238 87.6% 

Tennessee’s CAIR NOX Annual Trading Program includes provisions that allow these facilities to received surplus NOX allowances from 

Tennessee’s compliance supplement pool for NOX 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 NOX emissions. 

2. Other boilers (non-EGU) with more than 100 tons/year of NOX emissions. 

3. Industrial point sources with more than 100 tons/year of NOX emissions. 

4. Sources with less than 100 tons/year of NOX emissions. 

NOX Reductions from non-EGU Coal-Fired Boilers (> 100 tons/year NOX): NOX emissions 

from stationary source coal combustion (non-EGU) are summarized in Table 3- 1. Total NOX

emissions from these sources are 33.3% of projected 2009 NOX point source emissions. One of 

the three coal-fired boilers listed in Table 3- 1 (U. S. Department of Energy Y-12) is scheduled 

to be replaced by 2009, and NOX emissions from the new boilers will be significantly lower7. 

NOX control options for the remaining coal-fired boilers are based upon the AP-42 list of NOX

control technologies8

 and are listed in Table 3- 2. These options are rejected as potential RACT 

because it would not be possible to complete the required modifications in 2008 for most of the 

listed control options. The remaining option (load reduction) is likely to have a minimal effect 

on NOX emissions. 

Table 3- 1: NOX Emissions from Coal-Fired Boilers (non-EGU, > 100 tons/year) 

County SCC SCC Description 

2009 NOX

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 NOX emission limit for DOE’s natural gas-fired replacement boilers is 81 tons/year. 

8 See AP-42 emission factors, Chapter 1, Section 1.1 (External Combustion Sources, Bituminous and Subbituminous Coal Combustion), pages 

14-15 for the full list of NOX control options for coal-fired boilers. This list was narrowed by selecting only the options that were listed as viable 

for stoker boilers. 
14 

Table 3- 2: AP-42 List of NOX Control Options for Stoker Coal-Fired Boilers 

Control 

Technique 

Description Potential 

NOX

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. NOX 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 NOX

reduction without sacrificing boiler performance. 

Overfire air Injection of air 

above main 

combustion zone 

20-30% Must have sufficient furnace height above top row of 

burners in order to retrofit this technology to existing 

boilers. 

SNCR Injection of NH3 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. 

NOX Reductions from Other Boilers (> 100 tons/year NOX): The inventory lists one wood-fired 

boiler (Kimberly Clark in Loudon, TN) with more than 100 tons/year of NOX emissions (
15 

Table 3- 3). Total NOX emissions from this source are 2.4% of projected 2009 NOX point source 

emissions. A review of the Title V operating permit for this facility indicates that NOX

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 Title V permit also indicates that this boiler 

is permitted to burn paper sludge. NOX control options for biomass-fired boilers were not listed 

in AP-42, so RACT options were developed from the RACT-BACT-LAER Clearinghouse 

(RBLC) and are listed in Table 3- 4. 

Table 3- 4 indicates that add-on controls are typically necessary to reduce NOX emissions below 

the range of 0.35 – 0.44 lb/MMBtu. These options are not feasible as RACT, since it would be 

difficult to install add-on controls in less than twelve months. The RBLC indicates that NOX

emissions from two facilities are 0.2-0.22 lb/MMBtu. One of these sources burns a biomass 

other than wood, and is not considered as potential RACT. NOX controls for the remaining 

source (RBLC ID: LA-0218) are listed as “good combustion practices, boiler design and 

operation.” The RBLC determination suggests that low NOX emissions for this source are a 

result of the boiler design, and redesign of the existing boiler would not be a feasible option for 

RACT. 
16 

Table 3- 3: NOX Emissions from Other Boilers (non-EGU, > 100 tons/year) 

County SCC SCC Description 

2009 NOX

Emissions 

(tons) 

Loudon 10200903 

External Combustion Boilers - Industrial - Wood/Bark Waste - 

Wood-fired Boiler - Wet Wood (>=20% moisture) 120 

Table 3- 4: NOX Control Options for Biomass Boilers (RBLC) 

Facility and RBLC ID RBLC ID Allowable NOX

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 

NOX Reductions from Industrial Point Sources: Other industrial NOX sources with more than 

100 tons per year of emissions are listed in Table 3- 5. 

Table 3- 5: NOX Emissions from Industrial Point Sources (> 100 Tons per Year) 

County SCC SCC Description 

2009 NOX

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 2,371 
17 

Alcoa: NOX emissions from anode baking depend on operating practices and burner controls. 

The traditional methods of preventing NOX formation using staged combustion or low NOX 

burners are not applicable because 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 NOX emissions by reducing total fuel usage. Prevention of NOX

formation using advanced firing control is technically feasible for anode baking, but retrofit of 

the existing firing system would probably 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 & Lyle Emissions Reductions 

Pollutant Allowable Emissions from Title V 

Operating Permit (tons/year) 

Post-Project Allowable Emissions 

(tons/year) 

PM/PM10 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, 2005, by the Tennessee Air Pollution Control Board to resolve a citizens’ appeal of a construction 

permit issued for this facility (construction permit number 956292P, issued April 16, 2004). The facility is required to comply with the postproject allowable emissions upon completion of the construction project expanding the 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 sources 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 NOX

reductions. These options are therefore not suitable as RACT. 

Most of the options listed for CEMEX are not suitable as RACT for the same reason. The use of 

low-NOX burners might be a feasible control option for CEMEX, but at least one year would be 

necessary to implement the required rule change. CEMEX currently uses a mixture of tirederived fuel, mid-kiln firing, and SNCR to reduce NOX emissions, and NOX emissions from this 

facility are continuously monitored and recorded. 
18 

Table 3- 7: RACT Analysis for Knox County Sources 

Source Category 

Emissions Reduction Measure 

Estimated 

Control 

Efficiency 

Time to 

Implement 

(Months) 

Estimated Dat

of Completed 

Action 

Cement Kilns- Cemex Biosolids injection 23% 12 1/16/2009 Cement Kilns- Cemex Low NOX Burners 27-40% 6-12 7/16/2008 Cement Kilns- Cemex Selective Catalytic Reduction 31-95% 12 1/16/2009 Cement Kilns- Cemex SNCR-ammonia based 50% 12 1/16/2009 Cement Kilns- Cemex SNCR-urea based 50% 12 1/16/2009 Iron & Steel Mills - Annealing, Galvanizing, Reheating - Ameristeel Low NOX Burners 50-65% 6-12 1/16/2009 Iron & Steel Mills - Annealing, Galvanizing, Reheating - Ameristeel 

Low NOX Burners + Flue 

Gas Recirculation 60-77% 12 1/16/2009 

Iron & Steel Mills - Reheating - Ameristeel Low Excess Air 13% 12 1/16/2009 
19 

NOX 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 regulatory RACT/RACM requirement for a PM2.5 SIP 

revision can be found at 40 C.F.R. Section 51.1010: 

(a) For each PM2.5 nonattainment area, the State shall submit with the attainment 

demonstration a SIP revision demonstrating that it has adopted all reasonably 

available control measures (including RACT for stationary sources) necessary 

to demonstrate attainment as expeditiously as practicable and to meet any RFP 

requirements. The SIP revision shall contain the list of the 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. 

(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 impact of implementing the available 

measures. Potential measures that are reasonably available considering 

technical and economic feasibility must be adopted as RACM if, considered 

collectively, they would advance the attainment date by one year or more. 

NOX 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 NOX from onroad and nonroad engines would not be achievable 

in a timely fashion to expedite attainment of the PM2.5 NAAQS in the Knoxville PM2.5

Nonattainment Area. Significant NOX reductions from these sectors are expected to result from 

existing Federal measures affecting both fuels and engines. In addition, an I/M program for 

onroad Heavy-Duty Diesel Vehicles (HDDV) is not viable since a large proportion of HeavyDuty diesel trucks (tractor-trailer type) travel through the Knoxville Region from other States. 

Tennessee is limited in its ability to affect an enforcement program on vehicles which are 

registered outside of the nonattainment area. A majority of the NOX emissions from HDDVs 

comes from those out-of-State trucks which would 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, any group of potential RACM would need to provide sufficient 

reductions of NOX by 2009. The State has considered likely control measures to determine if 

collectively they could meet these criteria. Several mandatory programs are available that can 

provide moderate levels of emission reductions, but none of these measures can provide benefits 

by 2009, and the total overall reduction that could be provided by these measures is likely below 

any threshold which could advance the attainment date by an entire year. While there are 

potential voluntary measures that can be implemented before 2009, together these voluntary 
20 

measures will not provide sufficient creditable emission reductions to advance the attainment 

date by one year. Therefore, there are no RACM appropriate for the Knoxville PM2.5

Nonattainment Area. Further, existing measures scheduled to be implementation by 2009 are 

expected to bring the region to attainment with the PM2.5 NAAQS. As such, no further actions 

on RACT/RACM are warranted. 
21 

4.0 WEIGHT OF EVIDENCE FOR NOX

Section 2.3 of EPA’s Guidance on the Use of Models and Other Analyses for Demonstrating 

Attainment of Air Quality Goals For Ozone, PM2.5, and Regional Haze discusses basic 

requirements for weight of evidence analyses. This guidance states that States should review the 

results of the modeled attainment test and of several different types of air quality analyses. Each 

analysis should be weighed according to its credibility and its ability to assess the adequacy of 

the proposed attainment strategy, and the conclusions 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/m3 at one or more monitoring sites, the 

guidance states that a weight of evidence demonstration should be conducted to determine 

whether the aggregate supplemental analyses support the modeled attainment test. As indicated 

in Section 8.0 of the PM2.5 SIP, the predicted future design value at one monitor in the Knoxville 

nonattainment area is greater than 14.5 μg/m3

, 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 capacity 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 determination 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 evidence, viewed as a whole, supports a conclusion that the area will 

attain the NAAQS. This section provides additional NOX-related weight of evidence information 

for the PM2.5 SIP. 

The weight of evidence analysis for the Knoxville area is summarized in Table 4- 2, with 

additional supporting comments in the following paragraphs. 

Emissions Inventory: Changes in Direct PM2.5 and Precursor Emissions 

The Knoxville-area emission inventory was reviewed to determine whether the predicted 

emission reductions are: 1) significant (i. e., are the reductions a sizeable fraction of the total 

emissions inventory); and 2) likely to occur by 2009. 

NOX emissions from all sources in the nonattainment 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, Table 4- 1), as electric utilities begin year-round operation of 

existing NOX controls to comply with the provisions of the Clean Air Interstate Rule. Point 

source reductions from these counties account for about 74% of total NOX reductions between 

2002 and 2009. These reductions are considered highly likely to occur, since they are required 

for compliance with Federal regulations, and since existing NOX control equipment will be used 

for compliance. 
22 

Table 4- 1: NOX Reductions by Category 

County 

2002-2009 Change in NOX 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 significant (22% of total) NOX reductions from onroad mobile sources. 

These reductions will occur as more strict emission requirements are implemented for motor 

vehicles. However, the timing of these reductions depends upon the turnover rates of the 

existing fleet of motor vehicles, and these reductions are given less weight than 

contemporaneous reductions from electric utilities. 
23 

Table 4- 2: Summary of Weight of Evidence for NOX

Analysis Data Source 

Key Assumptions and Outcomes Qualitative Weighting 

Point Source NOX Reductions 

VISTAS/ASIP Base G/G2 Emission Inventory 

Significant NOX reductions from 

electric utilities by 2009. 

High weighting – reductions are required by Federal rules and utilize existing control equipment. 

Onroad Mobile Source NOX

Reductions 

VISTAS/ASIP Base G/G2 Emission Inventory 

Significant NOX reductions by 

2009, but of lesser magnitude than projected utility reductions. 

Medium to high weighting – Federal regulations require lower NOX emissions from onroad 

mobile sources, but timing of the reductions is dependent upon fleet turnover rate. 

Other NOX reductions 

VISTAS/ASIP Base G/G2 Emission Inventory and facility construction permit application. 

Slight increase in area source emissions is offset by modest decrease from nonroad mobile sources. 

Low weighting – emissions changes from area sources and nonroad mobile sources are modest compared to onroad and point source reductions. 
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 PM2.5 NAAQS by its attainment date. As 

discussed in the preamble to the PM2.5 implementation rule, the key requirements associated with 

contingency measures are: 

• Contingency measures must be fully adopted rules 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 other control measures for the area that are 

not included in the control strategy for the SIP. 

• The measures should provide for emission reductions equivalent to about one year of 

reductions needed for RFP, based on the overall 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 measures that would not be included 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. federal mobile source measures based on the 

incremental turnover of the motor vehicle fleet each year). 

Tennessee has elected to use a portion of the SO2 emission reductions obtained pursuant to the 

Clean Air Interstate Rule (40 CFR 96 Subparts AAA through III and TAPCR 1200-3-14-.04) to 

comply with the contingency plan requirements of the PM2.5 Implementation Rule. Specifically, 

Tennessee will use the reductions at Units 1 through 4 of Tennessee Valley Authority’s Kingston 

Fossil Plant to comply with the contingency plan requirements9

. 

• The CAIR rules were adopted by Tennessee and filed with the Secretary of State on 

August 10, 2006. Tennessee’s request to incorporate this rule into the State 

Implementation Plan10 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 Run is projected to be complete by the end of 2008, and the scrubber is projected 

to be operational throughout 2009. The ASIP attainment modeling for the Knoxville nonattainment area assumed that the scrubber at Bull Run 

would be operational. Since Tennessee used Bull Run’s projected reductions to demonstrate attainment in 2009, the State may not 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 rules into the SIP on September 8, 2006. 
25 

approved. Tennessee has fully adopted the CAIR rules11 and implementation of the rules 

is currently underway. The emission reductions 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 further action by the State or by EPA. For the SO2

reductions at TVA Kingston, the 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 PM2.5 design value for 2009 

would attain the NAAQS, but this modeling assumed that wet scrubber controls for the 

Kingston facility would not be in place during the attainment year. The SO2 reductions at 

Kingston comply with the requirement that contingency measures should consist of other 

control measures for the area that are not included in the control strategy for the SIP. 

• The emission reductions in the contingency plan provide for greater than one year of 

reductions needed for RFP, based on the overall 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 SO2 reductions from the proposed contingency measure are 

sufficient to account for one year of SO2 reductions between 2002 and 2009, plus one 

year of NOX reductions over the same period. This approach conservatively assumes that 

one ton of SO2 reductions will have the same impact on ambient PM2.5 concentrations as 

one ton of NOX reductions.12

• Direct PM2.5 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 PM2.5 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, NOX emissions do not significantly impact ambient PM2.5 concentrations in the 

Knoxville area, and that the positive impact of one ton of SO2 reductions will actually be far greater than the impact of equivalent NOX

reductions. The contingency plan conservatively assumes that, if additional SO2 reductions are to be used in lieu of NOX reductions, one ton of 

additional SO2 reduction must be obtained to substitute for each ton of NOX reductions. 
26 

Table 5- 1: Contingency Requirements for SO2 and NOX

Actual SO2 emissions from all source categories (area, nonroad, onroad, and point 

sources) in 2002 baseline year 

134,218 tons 

Projected SO2 emissions from all source categories (area, nonroad, onroad, and 

point sources) in 2009 attainment year 

93,155 tons 

SO2 reductions required from proposed contingency measures 5,866 tons13

Actual NOX emissions from all source categories (area, nonroad, onroad, and point 

sources) in 2002 baseline year 

89,264 tons 

Projected NOX emissions from all source categories (area, nonroad, onroad, and 

point sources) in 2009 attainment year 

36,567 tons 

NOX reductions required from proposed contingency measures 7,528 tons14

Total emission reductions (SO2 plus NOX) required from proposed 

contingency measures 

13,394 tons15

Projected SO2 reductions from TVA Kingston Units 6-9 after scrubber 

installation 

30,224 tons16

Tennessee notes that the SO2 emission reductions relied upon for contingency planning will be of 

greater magnitude than SO2, NOX, or direct PM2.5 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 more 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 SO2 reductions from Units 6-9 of TVA’s Kingston Fossil Plant were calculated from the ASIP emission inventories by (1) 

comparing 2002 actual emissions and 2009 emissions from TVA’s Bull Run Fossil Plant; (2) estimating a control efficiency for TVA Bull Run 

based on 2002 and 2009 emissions; (3) assuming the same control efficiency for TVA Kingston Units 6-9 upon installation and startup of the 

scrubber (TVA’s Kingston and Bull Run Fossil Plants will have the same control equipment); and (4) using the TVA Kingston’s 2002 actual 

emissions and the assumed control efficiency to project the 2009 emissions for Units 6-9. The results are summarized in the following table: 

Actual SO2 Emissions for TVA Bull Run in 2002 (tons) 36,729 

Projected SO2 Emissions for TVA Bull Run in 2009 (tons) 8,657 

Projected SO2 Control Efficiency for TVA Bull Run in 2009 76.4% 

Actual SO2 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 SO2 Emissions for TVA Kingston Units 6-9 (tons) 39,559 

Projected SO2 Control Efficiency for TVA Kingston (based on TVA Bull Run) 76.4% 

Projected SO2 Emissions for TVA Kingston After Scrubber Installation (tons) 9,335 

Projected SO2 Reduction for TVA Kingston Units 6-9 After Scrubber 

Installation (tons) 30,224 
27 

6.0 NOX MOTOR VEHICLE EMISSIONS BUDGET 

Tennessee believes that NOX emissions from all anthropogenic sources do not significantly 

contribute to PM2.5 nonattainment in the Knoxville area. If EPA does not agree with this 

demonstration, the following Motor Vehicle Emission Budget (MVEB) is proposed for use in 

transportation conformity determinations. Tennessee is seeking public comment on both 

alternatives: a Motor Vehicle Emission Budget (MVEB) for direct PM2.5 only, or alternatively, 

MVEBs for both direct PM2.5 and for NOX, as outlined below. Tennessee will include one or 

both MVEB’s in the SIP after considering EPA and public comments. 

NOX Motor Vehicle Emissions Budget 

The NOX MVEB was developed in the same manner, with the same assumptions, (temperature, 

humidity, etc.) as the PM2.5 budget; all assumptions and information used in developing the 

following NOX budget are the same as those used in developing the PM2.5 budget. As part of the 

consultation process on setting MVEBs, the consultation partners discussed the geographic 

extent of the MVEB. It was decided through Interagency Consultation (IAC) that a regional 

emissions budget would be the most appropriate for the Knoxville nonattainment area. 

The mobile inputs used to develop the attainment demonstration modeling as well as the MVEB 

were developed through interagency consultation with the transportation partners for this area. 

Emissions developed through the attainment demonstration modeling were used in evaluating the 

various precursors, since precursor information was available and extensive modeling and 

sensitivity analysis was conducted on this inventory. The MVEB is developed from modeling 

conducted by the Knoxville Transportation Planning Organization (TPO) so that the MVEB 

development is as consistent as possible with the methods used to determine conformity. Note, 

however, the Onroad Mobile emissions estimates 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 different models, inherently 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 transportation conformity rule in 40 CFR 93, specific emission budgets are 

hereby defined for the onroad mobile sources portion of the emissions inventory. The MVEB, 

for transportation conformity purposes for the Knoxville PM2.5 nonattainment area for 2009 is 

contained in Table 6- 1. This budget is to be used by the transportation authorities to assure that 

transportation plans, programs, and projects are consistent with, and conform to, the attainment 

and maintenance of acceptable air quality in the Knoxville area. This MVEB applies to the 

entire Knoxville PM2.5 nonattainment area, including the donut area contained in Roane County. 

Table 6- 1: NOX MVEB for 2009 

Pollutant: 2009 MVEB (tons/year) 

NOX 18,024.9