The North Carolina 8-Hour Ozone 

Reasonable Further Progress Demonstration 

for the 

Charlotte-Gastonia-Rock Hill, NC-SC 

8-Hour Ozone Nonattainment Area 

(Cabarrus, Gaston, Lincoln, 

Mecklenburg, Rowan, Union Counties and 

Coddle Creek and Davidson Townships in Iredell County) 

Prepared by: 

North Carolina Department of Environment and Natural Resources 

Division of Air Quality 

November 30, 2009
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The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone i 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

TABLE OF CONTENTS 

1 INTRODUCTION ....................................................................................................................... 1

2 CALCULATION METHOD FOR THE RFP TARGET............................................................. 1

3 EMISSIONS INVENTORY ........................................................................................................ 2

3.1 Stationary Point Sources ...................................................................................................... 3

3.2 Stationary Area Sources ....................................................................................................... 4

3.3 Off-Road Mobile Sources .................................................................................................... 4

3.4 Highway Mobile Sources ..................................................................................................... 5

3.5 Emissions Inventory Summary ............................................................................................ 5

4 ESTIMATION OF NON-CREDITABLE REDUCTIONS ......................................................... 6

5 REASONABLE FURTHER PROGRESS DEMONSTRATION ............................................. 10

6 MOTOR VEHICLE EMISSION BUDGETS ............................................................................ 11

6.1 Transportation Conformity ................................................................................................ 11

6.2 Motor Vehicle Emission Budgets ....................................................................................... 12

7 CONCLUSIONS........................................................................................................................ 14

LIST OF TABLES 

Table 3-1 Metrolina Nonattainment Area 2002 Baseline VOC Emissions (tons/day) .................. 5

Table 3-2 Metrolina Nonattainment Area 2008 Baseline VOC Emissions (tons/day) .................. 6

Table 4-1 Cabarrus County Non-Creditable VOC Emission Estimates ........................................ 7

Table 4-2 Gaston County Non-Creditable VOC Emission Estimates ........................................... 7

Table 4-3 Nonattainment Portion of Iredell County Non-Creditable VOC Emission Estimates .. 8

Table 4-4 Lincoln County Non-Creditable VOC Emission Estimates .......................................... 8

Table 4-5 Mecklenburg County Non-Creditable VOC Emission Estimates ................................. 9

Table 4-6 Rowan County Non-Creditable VOC Emission Estimates ........................................... 9

Table 4-7 Union County Non-Creditable VOC Emission Estimates ........................................... 10

Table 4-8 Total Metrolina Nonattainment Area Non-Creditable VOC Emission Estimates ....... 10

Table 5-1 Metrolina Nonattainment Area 15 Percent RFP Analysis ........................................... 11

Table 6-1 Metrolina Nonattainment Area 2008 NOx Emissions (tons/day) ............................... 12

Table 6-2 On-Road Mobile Source 2008 Emissions Metrolina Nonattainment Area ................. 13

Table 6-3 County Level MVEB for 2008 .................................................................................... 14
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone ii 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

APPENDICES 

Appendix A – MOBILE Files for Non-Creditable Emissions 

Appendix B – Point Source Emissions Inventory Documentation 

Appendix C – Area Source Emissions Inventory Documentation 

Appendix D – Nonroad Mobile Source Emissions Inventory Documentation 

Appendix E – On-Road Mobile Source Emissions Inventory Documentation 

Appendix F – Correspondence and Guidance 

Appendix G – VISTAS Supporting Documentation 

Appendix H – Public Hearing Record 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 1 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

1 INTRODUCTION 

Section 182(b)(1) of the Clean Air Act Amendments (CAAA) mandates a 15 percent volatile 

organic compounds (VOC) emission reduction, accounting for growth, in the first six years after 

the baseline year (2002) for Moderate and above ozone nonattainment areas. Thus, for the 

Charlotte-Gastonia-Rock Hill, NC-SC 8-hour ozone nonattainment area (referred to as the 

Metrolina area), a reasonable further progress (RFP) analysis between 2002 and 2008 is required. 

Although the Charlotte-Gastonia 1-hour ozone nonattainment area (comprised of Mecklenburg 

and Gaston Counties) was designated as Moderate following the 1990 CAAA, the area had 

measured attainment of the 1-hour standard prior to the 15 percent Rate of Progress (ROP) 

requirement coming due on November 15, 1993. Therefore, this area did not implement a 15 

percent ROP plan under the 1-hour standard, and the RFP requirement must be met through 

VOC reductions only, consistent with the CAAA. 

2 CALCULATION METHOD FOR THE RFP TARGET 

The methodology the North Carolina Division of Air Quality (NCDAQ) used to calculate the 

RFP target levels of VOC emissions is based on the method developed in the CAAA, while 

taking into account the restrictions on creditable emissions and the need to use the 2002 

inventory as a baseline. The CAAA specified four types of measures that were not creditable 

toward the 15 percent RFP requirement. These were: 

(1) Any measure relating to motor vehicle exhaust or evaporative emissions promulgated by 

the Administrator by January 1, 1990. 

(2) Regulations concerning Reid Vapor Pressure (RVP) promulgated after 1990 or required 

under section 211(h). 

(3) Measures required under section 182(a)(2)(A) to correct deficiencies in State 

Implementation Plans (SIPs) regarding VOC Reasonably Available Control Technology 

(RACT) regulations required prior to enactment of the CAAA. 

(4) State regulations submitted to correct deficiencies in vehicle inspection and maintenance 

(I/M) existing or required programs. 

These four types of measures were all expected to result in a decrease in emissions between 1990 

and 1996. Of these four types of measures, RACT and I/M program corrections and the 1992 

RVP requirements were completely in place by 1996 and therefore are already accounted for in 

the 2002 baseline. As a result, these measures would produce no additional reductions between 

2002 and 2008 or later milestone years. 

However, the pre-1990 Federal Motor Vehicle Control Program (FMVCP) will continue to 

provide additional benefits during the first two decades of the 21st century until all remaining 

vehicles meeting pre-1990 standards are removed from the vehicle fleet. Since these benefits are 

not creditable for RFP demonstration purposes, the reductions that would occur over these future 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 2 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

years as a result of the pre-1990 FMVCP must be calculated so that the target level of emissions 

for future RFP milestone year can be determined. The United States Environmental Protection 

Agency (USEPA) provided guidance on calculating the RFP targets for several kinds of areas in 

Appendix A (70 FR 71696) of the Phase 2 8-hour ozone implementation rule. Four methods 

were outlined in this guidance. 

The NCDAQ used Method 1 to account for non-creditable reductions when calculating RFP 

targets for the 2008 milestone year. It is consistent with requirements of Sections 182(b)(1)(C) 

and (D) and 182(c)(2)(B) of the CAAA. Only the on-road mobile source sector required an 

estimation of non-creditable emissions since all other controls would have been in place by 2002 

and no further reductions would have been expected between 2002 and 2008. 

Method 1: For areas that must meet a 15 percent VOC reduction requirement by 2008: 

(A) Estimate the actual anthropogenic base year VOC inventory in 2002 with all 2002 

control programs in place for all sources. 

(B) Using the same highway vehicle activity inputs used to calculate the actual 2002 

inventory, run the appropriate motor vehicle emissions model for 2002 and for 2008 

with all post-1990 Clean Air Act (CAA) measures turned off. Any other local inputs 

for vehicle I/M programs should be set according to the program that was required to 

be in place in 1990. Fuel RVP should be set at 9.0 or 7.8 pounds per square inch 

depending on the level required in the local area as a result of fuel RVP regulations 

promulgated in June 1990. 

(C) Calculate the difference between the 2002 and 2008 VOC emission factors calculated 

in Step B and multiply by 2002 vehicle miles traveled (VMT). The result is the VOC 

emissions reductions that will occur between 2002 and 2008 without the benefits of 

any post-1990 CAA measures. These are the non-creditable reductions that occur 

over this period. 

(D) Subtract the non-creditable reductions calculated in Step C from the actual 

anthropogenic 2002 inventory estimated in Step A. This adjusted VOC inventory is 

the basis for calculating the target level of emissions in 2008. 

(E) Reduce the adjusted VOC inventory calculated in Step D by 15 percent. The result is 

the target level of VOC emissions in 2008 in order to meet the 2008 RFP 

requirement. The actual projected 2008 inventory for all sources with all control 

measures in place and including projected 2008 growth in activity must be at or 

lower than this target level of emissions. 

3 EMISSIONS INVENTORY 

There are four different anthropogenic emission inventory source classifications: stationary point 

and area sources, and off-road and on-road mobile sources. Stationary point sources are those 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 3 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

sources that emit greater than a specified tonnage per year and the data is provided at the facility 

level. Stationary area sources are those sources whose emissions are relatively small but due to 

the large number of these sources, the collective emissions could be significant (i.e., dry 

cleaners, service stations, etc.). These types of emissions are estimated at the county level. Offroad mobile sources include equipment that can move but do not use the roadways, i.e., lawn 

mowers, construction equipment, railroad locomotives, aircraft, etc. The emissions from these 

sources, like stationary area sources, are estimated at the county level. On-road mobile sources 

are automobiles, trucks, and motorcycles that use the roadway system. The emissions from these 

sources are estimated by vehicle type and road type and are summed to the county level. 

For these sources of emissions, the 2002 base year and the 2008 milestone year emission 

inventories were developed. The 2002 base year emissions were from the 2002 modeling 

attainment demonstration. The 2008 milestone year emissions were either developed by 

applying growth and control factors to the 2002 base year emissions or using 2008 specific data. 

The 2008 inventory was processed through the Sparse Matrix Operator Kernel Emissions 

(SMOKE) pre-processing model so that the emissions would be comparable to the 2002 

attainment demonstration emissions inventory. 

In the sections that follow, a synopsis of the inventories used for each source classification is 

discussed. The detailed discussions of the emissions inventory development can be found in 

Appendices B through E. 

3.1 Stationary Point Sources 

Point source emissions are emissions from individual sources having a fixed location. Generally, 

these sources must have permits to operate and their emissions are inventoried on a regular 

schedule. Large sources having emissions of 100 tons per year (tpy) of a criteria pollutant, 

10 tpy of a single hazardous air pollutant (HAP), or 25 tpy total HAP are inventoried annually. 

Smaller sources have been inventoried less frequently. The point source emissions data can be 

grouped into the electric generating unit (EGU) sources and the other point sources, i.e., 

non-EGUs. Appendix B documents the point source inventory development in more detail. 

The 2002 base year inventory for the EGU sources used 2002 continuous emissions monitoring 

(CEM) data reported to the USEPA’s Acid Rain program. This data provides hourly emissions 

profiles that can be used in the modeling of these large sources of nitrogen oxides (NOx) 

emissions and helps to provide more accurate modeling of these sources. The 2008 milestone 

year EGU emissions inventory was provided by Duke Power. This inventory provided the 

company’s estimated emissions taking into consideration their compliance plan for the North 

Carolina Clean Smokestacks Act. 

For the non-EGU sources, the annual emissions as reported for the Consolidated Emissions 

Reporting Rule (CERR) for the year 2002 were used. These emissions were temporally 

allocated to month, day, and hour using source category code (SCC) based allocation factors 

using the SMOKE emissions pre-processing model. For the 2008 inventory, the general 

approach was to use recently updated growth and control data consistent with the USEPA’s 

Clean Air Interstate Rule (CAIR) analyses. The growth and control factors were applied 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 4 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

utilizing the SMOKE emissions pre-processing model, which also temporally allocated the 

emissions similar to the base year emissions inventory. 

3.2 Stationary Area Sources 

Stationary area sources include sources whose emissions are relatively small but due to the large 

number of these sources, the collective emissions could be significant (i.e., combustion of fuels 

for heating, structure fires, service stations, etc.). Emissions are estimated by multiplying an 

emission factor by some known indicator of collective activity, such as fuel usage, number of 

households, number of employees, or population. Stationary area source emissions are estimated 

on the county level. 

The NCDAQ developed the 2002 base year emissions inventory by collecting 2002 activity data 

for the various source subcategories and applying the USEPA developed emission factors. 

Growth factors supplied from the USEPA’s CAIR emission projections were applied to project 

the controlled emissions to the 2008 milestone year. In some cases, the USEPA’s Economic 

Growth and Analysis System Version 5 growth factors were used if no growth factor was 

available from the CAIR growth factor files. The growth and control factors were applied 

utilizing the SMOKE emissions pre-processing model, which also temporally allocated the 

emissions similar to the base year emissions inventory. 

Appendix C provides a detailed discussion of the area source inventory. 

3.3 Off-Road Mobile Sources 

Off-road mobile sources, also referred to as non-road mobile sources, include equipment that can 

move but does not use the roadways, such as construction equipment, aircraft, railroad 

locomotives, lawn and garden equipment, etc. For the majority of the non-road mobile sources, 

the emissions were estimated using the USEPA’s NONROAD2005c model. For two of the three 

source categories not included in the NONROAD model, i.e., aircraft engines and railroad 

locomotives, more traditional methods of estimating the emissions were used. There are no 

emissions in the Metrolina area for commercial marine emissions, the third category not included 

in the NONROAD model. 

For the source categories estimated using the USEPA’s NONROAD model, the model was used 

to create the 2008 milestone year inventory. The NONROAD model takes into consideration 

rules that are in effect that could impact the emissions from these source categories. For the 

large airport in the Metrolina area, the Federal Aviation Administration’s (FAA’s) Terminal 

Area Forecast was used to project growth in aircraft emissions. For the railroad locomotives and 

the remaining airport emissions, the 2008 emissions were grown using detailed inventory data 

(both before and after controls) for 1996 and 2010 obtained from the USEPA’s CAIR Technical 

Support Document. 

Appendix D provides a detailed discussion of the non-road mobile source inventory. 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 5 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

3.4 Highway Mobile Sources 

In order to accurately model the mobile source emissions in the Metrolina nonattainment area, 

the latest version of the MOBILE model, MOBILE6.2, was used. Key inputs for the MOBILE 

model include information on the age of vehicles on the roads, the average speed on the roads, 

the mix of vehicles on the roads, any control technologies in place in an area to reduce emissions 

for motor vehicles (e.g., emissions inspection programs), and temperature. The MOBILE model 

inputs were developed through interagency consultation with the transportation partners for this 

area. 

The MOBILE model takes into consideration rules in effect that impact the emissions from this 

source sector. The same model then is run for the milestone year emissions inventory using 

input data reflective of 2008. The 2002 and 2008 vehicle age and vehicle mix data were 

obtained from the North Carolina Department of Transportation (NCDOT). The vehicle miles 

traveled and speed data were provided by the Charlotte Department of Transportation (CDOT) 

and came from the Metrolina regional travel demand model. 

For a detailed discussion about the on-road mobile source inventory development and the data 

used in the RFP demonstration, please refer to Appendix E. 

3.5 Emissions Inventory Summary 

The NCDAQ’s 2002 baseline VOC emissions for the Metrolina area are presented in Table 3-1. 

The 2008 VOC emission estimates are presented in Table 3-2. Since the only portion of Iredell 

County designated as nonattainment are the townships of Coddle Creek and Davidson, the 

emissions for Iredell County have been adjusted to reflect this. For point sources, only the 

facilities located within the nonattainment area were used to estimate the emissions. For area 

sources and non-road mobile sources, these emissions are estimated at the county level. To 

estimate the emissions for the nonattainment area, the fraction of the County’s population in the 

two nonattainment townships (32.6% based upon the U.S. Census data) was used to apportion 

the emissions. For on-road mobile sources, the VMT and speeds for the nonattainment portion 

of the County were used to estimate the emissions. This information was provided by CDOT. 

Table 3-1 Metrolina Nonattainment Area 2002 Baseline VOC Emissions (tons/day) 

County Point Area Non-Road 

Mobile 

On-Road 

Mobile Total 

Cabarrus 2.2 6.0 2.7 20.5 31.4 

Gaston 2.5 8.9 2.9 13.3 27.6 

Iredell (partial) 0.9 1.9 0.9 6.6 10.3 

Lincoln 2.1 3.1 1.3 6.7 13.2 

Mecklenburg 5.7 29.4 24.1 66.1 125.3 

Rowan 6.3 5.6 2.3 14.2 28.4 

Union 1.0 6.4 4.7 12.3 24.4 

Total 20.7 61.3 38.9 139.7 260.6 
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North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 3-2 Metrolina Nonattainment Area 2008 Baseline VOC Emissions (tons/day) 

County Point Area Non-Road 

Mobile 

On-Road 

Mobile Total 

Cabarrus 2.3 5.9 1.5 10.4 20.1 

Gaston 2.7 9.4 2.0 7.5 21.6 

Iredell (partial) 0.7 1.8 0.5 5.4 8.4 

Lincoln 2.1 2.9 0.8 4.2 10.0 

Mecklenburg 5.9 30.1 13.0 38.0 87.0 

Rowan 6.0 5.6 1.5 9.2 22.3 

Union 1.2 5.7 1.7 9.9 18.5 

Total 20.9 61.4 21.0 84.6 187.9 

4 ESTIMATION OF NON-CREDITABLE REDUCTIONS 

As discussed in Section 2, the non-creditable emissions must be estimated and subtracted from 

the 2002 base year inventory. To calculate these emissions the USEPA’s MOBILE6.2 model is 

run for both years with the “NO CLEAN AIR ACT” flag set. 

The average daily speeds for 2002 and 2008 were used for the purpose of estimating the 

non-creditable emissions. The year specific vehicle age distribution and vehicle mix data were 

used as well. The fuel RVPs were set to the appropriate June 1990 requirements. Since the 

Metrolina area did not have an ozone I/M program in place in 1990, no I/M program was 

modeled in accordance with the USEPA guidance for determining non-creditable emissions. 

There were two instances in Iredell County where road types were reclassified between 2002 and 

2008, resulting in a mismatch between 2002 and 2008 emission factors. The NCDAQ needed to 

make some adjustments so that the non-creditable emissions could be calculated correctly. First, 

the 2008 urban principal arterial emission factor was used for the rural principal arterial emission 

factor since there were no longer any rural principal arterial road classes in the 2008 data. 

Similarly, there were no longer any rural interstate road classes in the 2008 data for the 

nonattainment portion of Iredell County. In this case, the urban interstate emission factor was 

used in place of the rural interstate emission factor. 

The difference between the 2002 and 2008 VOC emission factors was multiplied by the 2002 

VMT. The result is the VOC emission reductions that occurred between 2002 and 2008 without 

the benefits of any post-1990 CAA measures. These are the non-creditable emission reductions 

that have occurred over this period. 

The following table displays the results from the non-creditable emission estimates including the 

emission factors established through the MOBILE6.2 runs. The input and output files from these 

runs can be found in Appendix A. 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 7 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 4-1 Cabarrus County Non-Creditable VOC Emission Estimates 

Cabarrus County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate 0.000 0.000

 Rural principle arterial 324,349 2.093 1.734 0.359 0.128

 Rural minor arterial 211,964 2.118 1.741 0.377 0.088

 Rural major collector 385,957 2.184 1.889 0.295 0.126

 Rural minor collector 299,131 2.235 1.901 0.334 0.110

 Rural local 488,675 2.413 2.136 0.277 0.149

 Urban interstate 1,246,972 2.049 1.719 0.33 0.454

 Urban freeway - 0.000 0.000

 Urban principle arterial 670,359 2.445 2.123 0.322 0.238

 Urban minor arterial 583,244 2.416 2.148 0.268 0.172

 Urban collector 298,966 2.367 2.151 0.216 0.071

 Urban local 805,910 2.449 2.278 0.171 0.152

1.688

Table 4-2 Gaston County Non-Creditable VOC Emission Estimates 

Gaston County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate 202,517 1.506 1.185 0.321 0.072

 Rural principle arterial 227,278 1.364 1.292 0.072 0.018

 Rural minor arterial 317,040 1.537 1.382 0.155 0.054

 Rural major collector 460,235 1.523 1.423 0.100 0.051

 Rural minor collector 219,603 1.517 1.447 0.070 0.017

 Rural local 413,826 1.684 1.578 0.106 0.048

 Urban interstate 2,020,626 1.404 1.29 0.114 0.254

 Urban freeway 102,101 1.398 1.321 0.077 0.009

 Urban principle arterial 1,091,841 1.749 1.543 0.206 0.248

 Urban minor arterial 778,751 1.674 1.529 0.145 0.124

 Urban collector 75,464 1.768 1.686 0.082 0.007

 Urban local 801,096 1.713 1.702 0.011 0.010

0.912
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 8 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 4-3 Nonattainment Portion of Iredell County Non-Creditable VOC Emission 

Estimates 

Iredell County (NA portion)

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate 968,000 1.8 1.541 0.259 0.276

 Rural principle arterial 5,000 1.96 2.252 -0.292 -0.002

 Rural minor arterial 176,000 2.978 2.348 0.63 0.122

 Rural major collector 194,000 2.364 2.039 0.325 0.07

 Rural minor collector 143,000 2.5 2.255 0.245 0.039

 Rural local 354,000 2.5 2.193 0.307 0.12

 Urban interstate 8,000 1.914 1.541 0.373 0.003

 Urban freeway - 0 0

 Urban principle arterial 78,000 2.679 2.252 0.427 0.037

 Urban minor arterial 130,000 2.53 2.224 0.306 0.044

 Urban collector 43,000 2.567 2.361 0.206 0.01

 Urban local 153,000 2.922 2.314 0.608 0.103

0.822

Table 4-4 Lincoln County Non-Creditable VOC Emission Estimates 

Lincoln County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate - 0.000 0.000

 Rural principle arterial 252,752 1.897 1.688 0.209 0.058

 Rural minor arterial 556,376 2.242 1.94 0.302 0.185

 Rural major collector 175,958 2.065 1.782 0.283 0.055

 Rural minor collector 214,940 2.101 1.878 0.223 0.053

 Rural local 487,396 2.413 2.111 0.302 0.162

 Urban interstate - 0.000 0.000

 Urban freeway - 0.000 0.000

 Urban principle arterial 127,620 2.188 1.931 0.257 0.036

 Urban minor arterial 50,780 2.726 2.32 0.406 0.023

 Urban collector 24,699 2.641 2.151 0.490 0.013

 Urban local 254,959 2.449 2.278 0.171 0.048

0.633
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 9 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 4-5 Mecklenburg County Non-Creditable VOC Emission Estimates 

Mecklenburg County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate 0.000 0.000

 Rural principle arterial 862,659 1.583 1.379 0.204 0.194

 Rural minor arterial 889,625 1.716 1.568 0.148 0.145

 Rural major collector 102,926 1.473 1.576 -0.103 -0.012

 Rural minor collector 676,325 1.579 1.447 0.132 0.098

 Rural local 1,407,138 1.684 1.543 0.141 0.219

 Urban interstate 6,526,862 1.449 1.302 0.147 1.058

 Urban freeway 2,601,924 1.51 1.326 0.184 0.528

 Urban principle arterial 4,120,914 1.79 1.643 0.147 0.668

 Urban minor arterial 3,836,035 1.788 1.642 0.146 0.617

 Urban collector 1,675,106 1.813 1.686 0.127 0.235

 Urban local 2,961,152 1.713 1.825 -0.112 -0.366

3.384

Table 4-6 Rowan County Non-Creditable VOC Emission Estimates 

Rowan County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate 0.000 0.000

 Rural principle arterial 301,122 2.106 1.806 0.300 0.100

 Rural minor arterial 138,870 2.04 1.741 0.299 0.046

 Rural major collector 557,888 2.055 1.806 0.249 0.153

 Rural minor collector 230,904 2.058 1.844 0.214 0.054

 Rural local 647,760 2.413 2.136 0.277 0.198

 Urban interstate 1,365,153 1.907 1.649 0.258 0.388

 Urban freeway - 0.000 0.000

 Urban principle arterial 290,314 2.242 2.009 0.233 0.075

 Urban minor arterial 443,688 2.24 1.981 0.259 0.127

 Urban collector 196,149 2.321 2.127 0.194 0.042

 Urban local 698,343 2.449 2.278 0.171 0.132

1.315
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North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 4-7 Union County Non-Creditable VOC Emission Estimates 

Union County

2002 

Average 

Daily VMT

2002 w/o CAA 

(gram/mile)

2008 w/o CAA 

(gram/mile)

2002w/o CAA EF2008w/o CAA EF 

(gram/mile)

Non 

Creditable 

Emissions 

(tons/day)

 Rural Interstate - 0.000 0.000

 Rural principle arterial 879,771 2.068 1.794 0.274 0.266

 Rural minor arterial 225,913 2.082 1.781 0.301 0.075

 Rural major collector 723,540 2.133 1.877 0.256 0.204

 Rural minor collector 247,019 2.125 1.878 0.247 0.067

 Rural local 1,267,433 2.413 2.087 0.326 0.455

 Urban interstate - 0.000 0.000

 Urban freeway - 0.000 0.000

 Urban principle arterial 85,523 2.341 2.009 0.332 0.031

 Urban minor arterial 221,132 2.318 2.123 0.195 0.048

 Urban collector 44,271 2.272 2.026 0.246 0.012

 Urban local 279,986 2.449 2.217 0.232 0.072

1.230

The total non-creditable emissions for the Metrolina RFP demonstration are summarized in 

Table 4-8. 

Table 4-8 Total Metrolina Nonattainment Area Non-Creditable VOC Emission Estimates 

County Non-Creditable VOC 

Emissions (tons/day) 

Cabarrus 1.688 

Gaston 0.912 

Iredell 0.822 

Lincoln 0.633 

Mecklenburg 3.384 

Rowan 1.315 

Union 1.230 

Total 9.984 

5 REASONABLE FURTHER PROGRESS DEMONSTRATION 

To determine if reasonable further progress is demonstrated, the steps as outlined in Method 1 of 

the USEPA’s guidance are followed. 

• Step A is the actual anthropogenic base year VOC emissions inventory in 2002. This 

value comes from Table 3-1. 
The Charlotte-Gastonia-Rock Hill, NC-SC 8-Hour Ozone 11 

North Carolina Reasonable Further Progress Demonstration November 30, 2009 

• Step C are the non-creditable emissions which can be found in Table 4-8. 

• Step D is the 2002 base year emissions (Step A) minus the non-creditable emissions 

(Step C). 

• Step E is the 2008 target level VOC emissions which is calculated by reducing the 

emissions from Step D by 15 percent. 

• Finally, the estimated 2008 VOC emissions (Table 3-2) are compared to the 2008 target 

level VOC emissions (Step E). 

Since the 2008 VOC emissions are well below the target level, RFP is demonstrated for the 

Metrolina nonattainment area. Table 5-1 below provides the summary 15 percent RFP analysis 

showing the projected 2008 VOC emissions for the area, 187.9 tons/day, are well below the 

target level of emissions, 213.0 tons/day, as calculated using Method 1. 

Table 5-1 Metrolina Nonattainment Area 15 Percent RFP Analysis 

Metrolina 15% RFP Analysis VOC 

(tons/day) Step from Method 1 

Total 2002 Base year anthropogenic VOC emissions 260.6 Step A 

Non-creditable VOC reductions 10.0 Step C 

2002 base year minus the non-creditable emissions 250.6 Step D 

2008 target level of VOC emissions 213.0 Step E 

2008 projected VOC emissions 187.9 Projection < Target RFP goal met 

The NCDAQ must show continued progress from 2008 through the attainment date. To do so, 

the NCDAQ calculated the expected benefits from the fleet turnover for the on-road and off-road 

mobile sectors. Based on modeling emissions for 2009 and 2011, the NCDAQ expects 

approximately 14 tons per day of nitrogen oxides (NOx) emissions reductions from fleet 

turnover. Since the CAAA allows an area to focus on NOx emission reductions once the first 

RFP demonstration is approved, the NCDAQ did not calculate future expected VOC emissions 

reductions in these years due to the region being NOx limited. However, additional VOC 

reductions are expected from the fleet turnover of the on-road mobile sector. The NCDAQ 

believes these additional reductions demonstrate continued reasonable further progress toward 

attainment beyond 2008. 

6 MOTOR VEHICLE EMISSION BUDGETS 

6.1 Transportation Conformity 

Another requirement of the RFP demonstration is that VOC motor vehicle emission budgets 

(MVEBs), for transportation conformity purposes, need to be set for the RFP milestone year 

2008. The purpose of transportation conformity is to ensure that Federal transportation actions 
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North Carolina Reasonable Further Progress Demonstration November 30, 2009 

occurring in nonattainment and maintenance areas do not hinder the area from attaining and 

maintaining the 8-hour ozone standard. This means that the level of emissions estimated by the 

NCDOT or the metropolitan planning organizations for the Transportation Improvement 

Program and Long Range Transportation Plan must not exceed the MVEBs as defined in this 

RFP demonstration. 

Since the State is NOx limited with respect to ozone formation, as a SIP strengthening measure 

the NCDAQ has elected to also set NOx MVEBs. In order to establish NOx MVEBs, the 

USEPA requires the SIP to include the NOx emissions from all source sectors. Table 6-1 

summarizes the 2008 NOx emissions from all source sectors. The development of these 

emissions is discussed in Appendices B through E. 

Table 6-1 Metrolina Nonattainment Area 2008 NOx Emissions (tons/day) 

County Point Area Non-Road 

Mobile 

On-Road 

Mobile Total 

Cabarrus 2.6 1.5 4.1 9.6 17.8 

Gaston 32.8 2.2 4.8 10.0 49.8 

Iredell (partial) 0.5 0.4 0.9 6.9 8.7 

Lincoln 9.3 0.7 1.4 3.7 15.1 

Mecklenburg 2.0 11.3 20.9 45.6 79.8 

Rowan 22.4 1.3 4.6 9.5 37.8 

Union 0.2 1.5 3.3 7.4 12.4 

Total 69.8 18.9 40.0 92.7 221.4 

6.2 Motor Vehicle Emission Budgets 

As part of the consultation process on setting MVEBs, the NCDAQ sent out a request for 

comment on setting the geographic extent of the MVEBs to all of the transportation partners. A 

copy of the letter can be found in Appendix F. In the letter, the NCDAQ expressed its preference 

for setting county level budgets and the reasons why the NCDAQ believed county level budgets 

were appropriate. 

The NCDAQ received comments from several of the transportation partners regarding the 

geographic extent of the MVEBs. Some of the partners wanted county-by-county budgets; 

others wanted regional budgets. Those transportation partners preferring a regional budget stated 

in their letter that they would agree to county-by-county MVEBs for those areas wanting county 

level MVEBs and a single budget for the remainder of the North Carolina portion of the 

Metrolina nonattainment area. Copies of the letters received can be found in Appendix F. Upon 

careful consideration of all arguments, the NCDAQ decided to move forward with setting county 

level MVEBs. The NCDAQ believes that since mobile source NOx emissions play a significant 

role in the ozone formation in the Metrolina area, it is important that the large counties in the 

area meet the county level MVEBs that closely represent the emissions that were modeled for the 

attainment demonstration. 
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North Carolina Reasonable Further Progress Demonstration November 30, 2009 

The MVEBs will be set for the RFP milestone year 2008. Although the emissions are usually 

expressed in terms of tons per day, the MVEBs will be set in terms of kilograms (kg) per day. 

The reason for the change is because the MOBILE model generates the emissions factors in 

grams per mile. In past conformity exercises, there have been some issues with conversion to 

tons per day, as well as concerns with how the MVEBs were rounded to the hundredth place. 

Setting MVEBs in kilograms per day will avoid these issues in future conformity determinations. 

The mobile inputs used to develop the MVEBs were developed through interagency consultation 

with the transportation partners for this area. These inputs were consistent with what was used in 

the RFP demonstration, and do not represent a significant change to the emissions. 

The table below shows the North Carolina counties with their on-road mobile source emissions 

expressed in kilograms per day and the corresponding tons per day values for 2008. 

Table 6-2 On-Road Mobile Source 2008 Emissions Metrolina Nonattainment Area 

County 

NOx VOC 

Kg/day Tons/day Kg/day Tons/day 

Cabarrus 7,324 8.07 6,941 7.65 

Gaston 7,647 8.43 5,132 5.66 

Iredell* 5,637 6.21 3,601 3.97 

Lincoln 2,948 3.25 2,726 3.01 

Mecklenburg 34,526 38.06 26,368 29.07 

Rowan 7,193 7.93 6,149 6.78 

Union 5,660 6.24 6,299 6.94 

Total 70,935 78.19 57,216 63.08 

* Iredell County emissions for nonattainment area only. 

The NCDAQ is setting MVEB, for transportation conformity purposes, as county budgets within 

the Metrolina nonattainment area for 2008. Table 6-3 below lists out the MVEBs in kilograms 

per day, for transportation conformity purposes, by county. Upon the USEPA’s affirmative 

adequacy finding for these county level sub-area MVEBs, these MVEBs will become the 

applicable MVEBs for each county. 
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North Carolina Reasonable Further Progress Demonstration November 30, 2009 

Table 6-3 County Level MVEB for 2008 

County NOx MVEB 

(Kilograms/day) 

VOC MVEB 

(Kilograms/day) 

Cabarrus 7,324 6,941 

Gaston 7,647 5,132 

Iredell* 5,637 3,601 

Lincoln 2,948 2,726 

Mecklenburg 34,526 26,368 

Rowan 7,193 6,149 

Union 5,660 6,299 

* Iredell County MVEB for nonattainment area only 

7 CONCLUSIONS 

The NCDAQ has demonstrated that reasonable further progress has been made from the base 

year 2002 to the milestone year 2008. For purposes of SIP strengthening, the NCDAQ has 

established NOx MVEBs in addition to the required VOC MVEBs for 2008.