Supplement to the 

Redesignation Demonstration and Maintenance Plan 

for the 

Hickory (Catawba County) and 

Greensboro/Winston-Salem/High Point 

(Davidson and Guilford Counties) 

Fine Particulate Matter Nonattainment Areas 

Prepared by 

North Carolina Department of Environment and Natural Resources 

Division of Air Quality 

December 22, 2010 
(This page intentionally left blank) 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 1 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

INTRODUCTION 

This document is intended to supplement the Redesignation Demonstration and Maintenance 

Plan for the Hickory (Catawba County) and Greensboro/Winston-Salem/High Point (Davidson 

and Guilford Counties) Fine Particulate Matter Nonattainment Areas that was submitted to the 

United States Environmental Protection Agency (USEPA) on December 18, 2009. This 

document revises the on-road mobile source emissions and the motor vehicle emission budgets 

(MVEBs) using the new USEPA mobile model Motor Vehicle Emission Simulator (MOVES). 

In March 2010, the USEPA announced in the Federal Register (FR) that the new MOVES model 

was required for State Implementation Plan purposes and would be required for transportation 

conformity purposes starting March 2012 (40 FR 9411). The North Carolina Division of Air 

Quality (NCDAQ) committed to the transportation partners to revise the MVEBs once the new 

mobile model was released. 

REVISED SECTIONS 

Attached are the revised sections to the Redesignation Demonstration and Maintenance Plan for 

the Hickory and Greensboro/Winston-Salem/High Point Fine Particulate Matter Nonattainment 

Areas. To appropriately revise the original package, replace the pages as outlined below: 

Narrative Replacements 

Replace December 18, 2009 page 3-6 with the attached December 22, 2010 page 3-6. (Note that 

Errata December 22, 2010 page 3-7 has been included for ease of substitution.) 

Replace December 18, 2009 pages 3-13 through 3-17 with the attached December 22, 2010 

pages 3-12 through 3-17. (Note that Errata December 22, 2010 page 3-12 has been included for 

ease of substitution.) 

Replace December 18, 2009 pages 4-8 through 4-11 with the attached December 22, 2010 pages 

4-8 through 4-11. 

Appendix C Replacements 

Replace all of December 18, 2009 Appendix C.3 “On-Road Mobile Source Emission Inventory 

Documentation” with the attached December 22, 2010 Appendix C.3 “On-Road Mobile Source 

Emission Inventory Documentation”. 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 2 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Appendix E Replacements 

Replace December 18, 2009 Appendix E “Public Notice Report, Comments Received and 

Responses” page i with the attached December 22, 2010 Appendix E page i. (Note that 

December 18, 2009 Appendix E page ii has been included for ease of substitution.) 

Add December 22, 2010 Appendix E pages 15 through 23 to end of December 18, 2009 

Appendix E. 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-6 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-1 OBDII Phase-in Effective Dates 

County Date 

Catawba July 1, 2003 

Davidson July 1, 2003 

Guildford July 1, 2002 

 

These emission reductions are state enforceable. The expected NOx benefits for the maintenance 

years are listed in Table 3-2 below. 

Table 3-2 I/M NOx Benefits by County 

NOx I/M Benefit (Tons/year) 2008 2011 2014 2017 2021 

Catawba County 171 136 132 122 111 

Davidson County 180 166 139 129 114 

Guilford County 541 505 403 358 318 

NOx SIP Call Rule/CAIR

In response to the USEPA’s NOx SIP call, North Carolina adopted rules to control the emissions 

of NOx from large stationary combustion sources. These rules cover (1) fossil fuel-fired 

stationary boilers, combustion turbines, and combined cycle systems serving a generator with a 

nameplate capacity greater than 25 MW and selling any amount of electricity, (2) fossil fuelfired stationary boilers, combustion turbines, and combined cycle systems having a maximum 

design heat input greater than 250 million British thermal units per hour, and (3) reciprocating 

stationary internal combustion engines rated at equal to or greater than 2400 brake horsepower 

(3000 brake horsepower for diesel engines and 4400 brake horsepower for dual fuel engines). 

As part of the NOx SIP Call, the USEPA rules established a NOx budget for sources in North 

Carolina and other states. North Carolina has a Phase II budget (i.e., emission allowance) of 

165,022 tons NOx per ozone season. 

Besides amending existing NOx rules and adopting new NOx rules specifically to address the 

USEPA NOx SIP Call, the North Carolina rules also require new sources to control emissions of 

NOx. The objective of this requirement is (1) to aid in meeting the NOx budget for North 

Carolina for minor sources and (2) to aid in attaining and maintaining the ambient air quality 

standard for ozone in North Carolina. North Carolina’s NOx SIP Call rule was predicted to 

reduce summertime NOx emissions from power plants and other industries by 68% by 2006. In 

October 2000, the North Carolina Environmental Management Commission (EMC) adopted 

rules requiring the reductions. 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-7 

Errata to the Redesignation Demonstration and Maintenance Plan December 22, 2010 

In 2009, the NOx SIP Call program was replaced with the CAIR, a cap-and-trade program that 

will achieve reductions of emissions of SO2 and NOx in the eastern United States. NOx sources 

that were regulated under the NOx SIP Call are now regulated under the CAIR program. North 

Carolina adopted the CAIR rules in 2006 (amended in 2008). North Carolina’s CAIR rules set 

annual SO2 allowances as well as both ozone season and annual NOx allowances for coal-fired 

electric generating units and other large combustion sources. These regulations are due to a 

Federal program and thus are both State and Federally enforceable. 

Due to the Court challenges of CAIR in 2008, the USEPA will be making changes to this 

program soon. However, the existing CAIR rules will remain in place until the USEPA 

promulgates changes to the program. 

Clean Smokestacks Act

In June 2002, the North Carolina General Assembly enacted the NCCSA, which requires coalfired power plants in North Carolina to reduce annual NOx emissions by 77% by 2009. These 

power plants must also reduce annual SO2 emissions by 49% by 2009 and 73% by 2013. It is 

significant to note that this law sets a cap on NOx and SO2 emissions for the State which the 

North Carolina public utilities cannot meet by purchasing credits from sources outside of North 

Carolina. With requiring year-round NOx controls and not allowing the purchase of NOx credits 

to meet the caps, the NCCSA reduces NOx emissions beyond the requirements of the NOx SIP 

Call Rule. One of the first state laws of its kind in the nation, this legislation provides a model 

for other states in controlling multiple air pollutants from older coal-fired power plants. These 

emissions reductions are state enforceable. 

Prevention of Significant Deterioration 

All new major sources of SO2 and NOx will be evaluated under the prevention of significant 

deterioration program and are required to use best available control technology. These emissions 

reductions are state enforceable. 

Open Burning

The North Carolina open burning regulation prohibits the burning of man-made materials 

statewide. In June 2004, the EMC approved revisions to the open burning regulation banning 

open burning of yard waste and land clearing debris on forecasted Code Orange or higher "air 

quality action days," for those counties that the NCDAQ or local air programs forecast ozone or 

fine particulate matter. The following counties in the Hickory area are subject to this rule: 

Alexander, Catawba, southeastern Burke and southeastern Caldwell. The following counties in
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-12 

Errata to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-5 Point Source SO2 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 6,189 6,187 6,186 6,184 6,183 

Davidson 286 289 292 295 299 

Guilford 449 451 453 455 458 

Triad Total 735 740 745 750 757 

Table 3-6. Point Source PM2.5 Emissions (tons per year) 

County 2008 2011 2014 2017 2021 

Catawba 6,976 6,975 6,975 6,973 6,971 

Davidson 179 178 177 176 175 

Guilford 62 62 62 63 63 

Triad Total 241 240 239 239 238 

Area sources are those stationary 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.). For area sources, emissions are estimated by multiplying an emission 

factor by some known indicator of collective activity such as production, number of employees, 

or population. These types of emissions are estimated on the county level. For the projected 

year's inventory, area source emissions are changed by population growth, projected production 

growth, or when applicable, by E-GAS 5.0 growth factors. For detailed discussion on how the 

area source emission inventory was developed, see Appendix C.2. A summary of the area source 

emissions are presented in Tables 3-7 to 3-9. 

Table 3-7. Area Source NOx Emissions (tons per year) 

County 2008 2011 2014 2017 2021 

Catawba 662 614 566 520 454 

Davidson 583 551 516 486 438 

Guilford 1,243 1,210 1,177 1,146 1,099 

Triad Total 1,826 1,816 1,693 1,632 1,537 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-13 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-8. Area Source SO2 Emissions (tons per year) 

County 2008 2011 2014 2017 2021 

Catawba 2,263 2,037 1,808 1,580 1,277 

Davidson 983 838 692 548 353 

Guilford 4,129 3,905 3,683 3,460 3,164 

Triad Total 5,112 4,743 4,375 4,008 3,517 

Table 3-9. Area Source PM2.5 Emissions (tons per year) 

County 2008 2011 2014 2017 2021 

Catawba 682 658 629 606 559 

Davidson 1,071 1,028 979 937 857 

Guilford 697 663 623 590 524 

Triad Total 1,768 1,691 1,602 1,527 1,381 

For mobile sources, the USEPA’s Motor Vehicle Emission Simulator (MOVES) mobile model is 

run to generate emissions. The MOVES model includes the road class vehicle miles traveled 

(VMT) as an input file and can directly output the estimated emissions. For the projected years’ 

inventories, the on-road mobile sources emissions are calculated by running the MOVES mobile 

model for the future year with the projected VMT to generate emissions that take into 

consideration expected Federal tailpipe standards, fleet turnover and new fuels. For detailed 

discussion on how the on-road mobile emission inventory was developed, see Appendix C.3. A 

summary of the on-road mobile source emissions are presented in Tables 3-10 to 3-12. 

Table 3-10. On-road Mobile Source NOx Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 4,982 4,005 3,240 2,591 2,054 

Davidson 5,267 4,095 3,227 2,536 1,974 

Guilford 14,499 11,157 8,882 7,143 5,796 

Triad Total 19,766 15,252 12,109 9,679 7,770 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-14 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-11. On-road Mobile Source SO2 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 35 20 18 19 20 

Davidson 36 19 17 18 18 

Guilford 111 62 55 59 63 

Triad Total 147 81 72 77 81 

Table 3-12. On-road Mobile Source PM2.5 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 166 127 107 89 73 

Davidson 169 121 97 77 60 

Guilford 465 330 272 221 183 

Triad Total 634 451 369 298 243 

Nonroad mobile sources are equipment that can move but do not use the roadways, i.e., lawn 

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

category are calculated using the USEPA’s NONROAD2008a nonroad mobile model, with the 

exception of the railroad locomotives and aircraft engine. The railroad locomotive and aircraft 

engine emissions are estimated by taking activity data, such as landings and takeoffs, and 

multiply by an emission factor. These emissions are also estimated at the county level. For the 

projected years’ inventories, the emissions are estimated using the USEPA’s NONROAD2008a 

nonroad mobile model, E-GAS 5.0 growth factors or projected landing and takeoff data for 

aircraft. For detailed discussion on how the nonroad mobile emission inventory was developed, 

see Appendix C.4. A summary of the nonroad mobile source emissions are presented in 

Tables 3-13 to 3-15. 

Table 3-13. Nonroad Mobile Source NOx Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 1,173 922 700 551 453 

Davidson 1,831 1,632 1,467 1,275 1,115 

Guilford 3,864 3,371 2,816 2,350 1,980 

Triad Total 5,695 5,003 4,283 3,625 3,095 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-15 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-14. Nonroad Mobile Source SO2 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 18 6 4 3 4 

Davidson 25 17 2 2 2 

Guilford 96 51 42 42 43 

Triad Total 121 68 44 44 45 

Table 3-15. Nonroad Mobile Source PM2.5 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 70 67 57 46 38 

Davidson 71 67 58 46 40 

Guilford 264 252 220 186 157 

Triad Total 335 319 278 232 197 

3.3.3 Summary of Emissions 

The sum total of these man-made emissions for the PM2.5 nonattainment areas is tabulated in 

Tables 3-16 though 3-18. 

Table 3-16. Total Man-Made NOx Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 20,127 16,090 15,054 14,210 13,509 

Davidson 8,522 7,143 6,102 5,217 4,488 

Guilford 19,837 15,969 13,107 10,872 9,112 

Triad Total 28,359 23,112 19,209 16,089 13,600 

Table 3-17. Total Man-Made SO2 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 8,505 8,250 8,016 7,786 7,484 

Davidson 1,330 1,163 1,003 863 672 

Guilford 4,785 4,469 4,233 4,016 3,728 

Triad Total 6,115 5,632 5,236 4,879 4,400 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-16 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 3-18. Total Man-Made PM2.5 Emissions (tons per year)

County 2008 2011 2014 2017 2021 

Catawba 7,894 7,827 7,768 7,714 7,641 

Davidson 1,490 1,394 1,311 1,236 1,132 

Guilford 1,488 1,307 1,177 1,060 927 

Triad Total 2,978 2,701 2,488 2,296 2,059 

3.3.4 Maintenance Demonstration 

As discussed above, maintenance is demonstrated when the future years total man-made 

emissions are less than the 2008 baseline emissions. The following tables summarized the SO2, 

NOx, and primary PM2.5 emissions for both the Hickory and Triad nonattainment areas. The 

difference between the base year and the final year of the plan illustrates that the continued 

maintenance of the annual fine particulate matter NAAQS is expected. 

Table 3-19 Maintenance Demonstration for Hickory PM2.5 Nonattainment Area 

Year NOx 

(tons per year) 

SO2 

(tons per year) 

PM2.5 

(tons per year) 

2008 20,127 8,505 7,894 

2011 16,090 8,250 7,827 

2014 15,054 8,016 7,768 

2017 14,210 7,786 7,714 

2021 13,509 7,484 7,641 

Difference from 

2008 to 2021 -6,618 -1,021 - 253 

Table 3-20 Maintenance Demonstration for Triad PM2.5 Nonattainment Area 

Year NOx

(tons per year) 

SO2

(tons per year) 

PM2.5

(tons per year) 

2008 28,359 6,115 2,978 

2011 23,112 5,632 2,701 

2014 19,209 5,236 2,488 

2017 16,089 4,879 2,296 

2021 13,600 4,400 2,059 

Difference from 

2008 to 2021 -14,759 -1,715 - 919 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 3-17 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

The difference between the attainment level of emissions (2008) from all man-made sources and 

the projected level of emissions from all man-made sources in the nonattainment areas are 

considered the “safety margin”. The safety margin for each projected year is listed below in 

Table 3-21 and 3-22. 

Table 3-21 Safety Margin for Hickory PM2.5 Nonattainment Area 

Year NOx

(tons per year) 

SO2

(tons per year) 

PM2.5

(tons per year) 

2011 -4,037 -255 -67 

2014 -5,073 -489 -126 

2017 -5,917 -719 -180 

2021 -6,618 -1,021 -253 

Table 3-22 Safety Margin for Triad PM2.5 Nonattainment Area 

Year NOx

(tons per year) 

SO2

(tons per year) 

PM2.5

(tons per year) 

2011 -5,247 -483 -277 

2014 -9,150 -879 -490 

2017 -12,270 -1,236 -682 

2021 -14,759 -1,715 -919 

For both nonattainment areas, there are significant safety margins from 2011 to 2021. In 

addition to the above safety margins within the PM2.5 nonattainment areas, SO2 emissions from 

nearby coal-fired power plants will be significantly reduced due to the NCCSA. This effectively 

gives the PM2.5 nonattainment areas an even larger safety margin for SO2. Table 2-5 shows the 

SO2 reductions at nearby coal-fired power plants. These reductions will benefit both the Triad 

and Hickory nonattainment areas and will provide large safety margins through 2021. 

3.4 CONTINGENCY PLAN 

3.4.1 Overview 

The two main elements of the North Carolina contingency plan are tracking and triggering 

mechanisms to determine when contingency measures are needed and a process of developing 

and adopting appropriate control measures. There will be three potential triggers for the 

contingency plan. The primary trigger of the contingency plan will be a violation of the annual 

PM2.5 NAAQS at any of the monitors in either PM2.5 nonattainment area. The secondary trigger 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 4-8 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

copy of the letter can be found in Appendix B. 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 the Greensboro Urban Area Metropolitan Planning 

Organization (GUAMPO) regarding the geographic extent of the MVEBs. The GUAMPO was 

in favor of having county level MVEBs. A copy of the letter received can be found in 

Appendix B. Therefore, the NCDAQ decided to move forward with setting county-by-county 

MVEBs. 

Additionally, there was discussion through the interagency consultation process on the years to 

set MVEBs for the Hickory and Triad PM2.5 maintenance plans. According to Section 93.118 of 

the transportation conformity rule, a maintenance plan must establish MVEBs for the last year of 

the maintenance plan (in this case, 2021). Through the interagency consultation process, it was 

decided that MVEBs would be set for the year 2011 for both the Hickory and Triad PM2.5

nonattainment areas. 

Although the emissions up to this point have been expressed in terms of tons per year, the 

MVEBs will be set in terms of kilograms (kg) per year. In past conformity exercises, there have 

been some issues with conversion to tons, as well as concerns with how the MVEBs were 

rounded to the hundredth place. Setting MVEBs in kilograms will avoid these issues in future 

conformity determinations. Additionally, setting the MVEBs in kilograms was agreed to as part 

of the interagency consultation process. 

The table below shows the counties with their on-road mobile PM2.5 and NOx emissions 

expressed in kilograms per year and the corresponding tons per year values for 2011 and 2021. 

Table 4-1. On-Road Mobile Source PM2.5 Emissions 

County Kilograms/year Tons/year 

2011 2021 2011 2021 

Davidson 109,769 54,431 121 60 

Guilford 299,371 166,015 330 183 

Triad Total 409,140 220,446 451 243 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 4-9 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 4-2. On-Road Mobile Source NOx Emissions 

County Kilograms/year Tons/year 

2011 2021 2011 2021 

Catawba 3,633,274 1,863,357 4,005 2,054 

Davidson 3,714,921 1,790,782 4,095 1,974 

Guilford 10,121,459 5,258,042 11,157 5,796 

Triad Total 13,836,380 7,048,824 15,252 7,770 

The NCDAQ will set MVEB, for transportation conformity purposes, as county budgets within 

the Hickory and Triad maintenance areas for 2011 and 2021. Tables 4-3 through 4-5 below list 

out the MVEBs in kilograms per year, for transportation conformity purposes, by county for the 

years 2011 and 2021. Upon the USEPA’s affirmative adequacy finding for these county level 

sub-area MVEBs, these MVEBs will become the applicable MVEBs for each county. 

Table 4-3 Catawba County MVEB 

 2011 2021 

NOx Emissions (kg/year)

Base Emissions 3,633,274 1,863,357 

Safety Margin Allocated to MVEB 363,327 372,671 

NOx Conformity MVEB 3,996,601 2,236,028 

Table 4-4 Davidson County MVEB 

 2011 2021 

NOx Emissions (kg/year)

Base Emissions 3,714,921 1,790,782 

Safety Margin Allocated to MVEB 371,492 358,156 

NOx Conformity MVEB 4,086,413 2,148,938 

PM2.5 Emissions (kg/year)

Base Emissions 109,769 54,431 

Safety Margin Allocated to MVEB 43,544 98,882 

PM2.5 Conformity MVEB 153,313 153,313 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 4-10 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 4-5 Guilford County MVEB 

 2011 2021 

NOx Emissions (kg/year)

Base Emissions 10,121,459 5,258,042 

Safety Margin Allocated to MVEB 1,012,146 1,051,608 

NOx Conformity MVEB 11,133,605 6,309,650 

PM2.5 Emissions (kg/year)

Base Emissions 299,371 166,015 

Safety Margin Allocated to MVEB 122,470 255,826 

PM2.5 Conformity MVEB 421,841 421,841 

4.5 NEW SAFETY MARGINS 

For the Hickory nonattainment area, a total of 363,327 kg/year (400 tons/year) and 

372,671 kg/year (411 tons/year) of the 2011 and 2021 NOx safety margins, respectively, were 

added to the NOX MVEBs. 

 For the Triad nonattainment area, a total of 1,383,638 kg/year (1,525 tons/year) and 

1,409,764 kg/year (1,554 tons/year) of the 2011 and 2021 NOx safety margins, respectively, were 

added to the Triad NOX MVEBs. For PM2.5, a total of 166,014 kg/year (183 tons/year) and 

354,708 kg/year (391 tons/year) of the 2011 and 2021 PM2.5 safety margins, respectively, were 

added to the Triad PM2.5 MVEBs. 

Table 4-6 New Safety Margins for the Hickory PM2.5 nonattainment area 

Year NOx (tons/year) PM2.5 (tons/year) 

2011 -3,637 -67 

2014 -5,073 -126 

2017 -5,917 -180 

2021 -6,207 -253 
Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 4-11 

Supplement to Redesignation Demonstration and Maintenance Plan December 22, 2010 

Table 4-7 New Safety Margins for the Triad PM2.5 nonattainment area 

Year NOx (tons/year) PM2.5 (tons/year) 

2011 -3,722 -94 

2014 -9,150 -490 

2017 -12,270 -682 

2021 -13,205 -528