Appendix C.2 

Area Source Emissions 

Inventory Documentation 
(This page intentionally left blank)
Area Sources Documentation i 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

i

TABLE OF CONTENTS

1. INTRODUCTION AND SCOPE ............................................................................................... 1

2.0 OVERALL METHODOLOGY ................................................................................................ 2

2.1 Source Category Identification ............................................................................................ 2

2.2 Area Source Emission Estimation Approach ....................................................................... 2

3. QUALITY ASSURANCE OF EMISSIONS INVENTORY ..................................................... 5

4. DISCUSSION OF AREA SOURCE CATEGORIES ................................................................ 6

4.1 Forest Fires......................................................................................................................... 6

4.2 Structure Fires .................................................................................................................... 8

4.3 Open Burning – Municipal Solid Waste and Yard Trimmings ....................................... 11

4.4 On-Site Incineration ......................................................................................................... 15

4.5 Vehicle Fires .................................................................................................................... 17

4.6 Small Stationary Source Fossil Fuel Use ......................................................................... 21
Area Sources Documentation ii 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

ii

LIST OF TABLES 

Table 1-1 Hickory Nonattainment Area Source Emissions ........................................................... 1

Table 1-2 Triad Nonattainment Area Source Emissions ............................................................... 1

Table 2.2-1 Total County Population............................................................................................. 3

Table 2.2-2 2000 Census Rural Population Percentages ............................................................... 3

Table 2.2-3 2008 Rural Population ................................................................................................ 3

Table 4.1-1 Acres of Land Burned by Wild Fires ......................................................................... 6

Table 4.1-2 Emissions from Wildfires ........................................................................................... 7

Table 4.1-3 Acres and Tons Burned from the NCDFR Prescribed Fires ...................................... 8

Table 4.1-4 Emissions from Prescribed Fires ................................................................................ 8

Table 4.2-1 Growth Factors for Structure Fires ............................................................................. 9

Table 4.2-2 Emissions from Structure Fire .................................................................................. 10

Table 4.3-2 Growth Factors for Open Burning ............................................................................ 11

Table 4.3-3 Rule Effectiveness for MSW Open Burning ............................................................ 12

Table 4.3-4 Emissions from Municipal Solid Waste ................................................................... 14

Table 4.3-5 Emissions from Yard Trimmings ............................................................................. 14

Table 4.4-1 Yield of Pollutant Values for Uncontrolled Refuse Combustors ............................. 15

Table 4.4-2 Growth Factors for On-Site Incineration .................................................................. 15

Table 4.4-3 Emissions from On-Site Incineration ....................................................................... 17

Table 4.5-1 Catawba County Vehicle Miles Traveled ................................................................. 18

Table 4.5-2 Davidson County Vehicle Miles Traveled ............................................................... 19

Table 4.5-3 Guilford County Vehicle Miles Traveled ................................................................. 19

Table 4.5-4 Growth Factors for Vehicle Fires ............................................................................. 20

Table 4.5-5 Emissions from Vehicle Fires .................................................................................. 21

Table 4.6-1 2007 Fuel Use in North Carolina.............................................................................. 22

Table 4.6-2 Fuel Combustion Emission Factors ........................................................................... 23

Table 4.6-3 Residential Fuel Apportionment ............................................................................... 24

Table 4.6-4 Commercial and Industrial Fuel Apportionment ...................................................... 24

Table 4.6-5 Residential Growth Factors for Fuel Combustion .................................................... 25

Table 4.6-6 Manufacturing Employment per County .................................................................. 25

Table 4.6-7 Commercial/Industrial Growth Factors for Fuel Combustion .................................. 26
Area Sources Documentation iii 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

iii

Table 4.6-8 Residential Source Sector Fuel Oil Emissions ......................................................... 27

Table 4.6-9 Residential Source Sector LPG Emissions ............................................................... 28

Table 4.6-10 Residential Source Sector NG Emissions............................................................... 29

Table 4.6-11 Residential Source Sector Wood Emissions........................................................... 30

Table 4.6-12 Commercial Coal Combustion Emissions .............................................................. 31

Table 4.6-13 Commercial Fuel Oil Combustion Emissions ........................................................ 32

Table 4.6-14 Commercial LPG Combustion Emissions .............................................................. 33

Table 4.6-15 Commercial NG Combustion Emissions ................................................................ 34

Table 4.6-16 Industrial Fuel Oil Combustion Emissions ............................................................. 35

Table 4.6-17 Industrial LPG Combustion Emissions .................................................................. 36

Table 4.6-18 Industrial NG Combustion Emissions .................................................................... 37

Table 4.6-19 Point Source Commercial Coal Combustion Emissions ........................................ 38

Table 4.6-20 Point Source Commercial Fuel Oil Combustion Emissions ................................... 38

Table 4.6-21 Point Source Commercial Natural Gas Combustion Emissions ............................. 38

Table 4.6-22 Point Source Industrial Fuel Oil Combustion Emissions ....................................... 39

Table 4.6-23 Point Source Industrial Natural Gas Combustion Emissions ................................. 39
Area Sources Documentation iv 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

iv

List of Acronyms 

Acronym Definition 

BTS Bureau of Transportation Statistics 

BTU British Thermal Units 

CNG Compressed Natural Gas 

EF Emission Factor 

EGAS 5.0 Economic Growth Analysis System version 5.0 

EIA Energy Information Administration 

EIIP Emissions Inventory Improvement Program 

GF Growth Factor 

LPG Liquid Petroleum Gas 

MSW Municipal Solid Waste 

NAAQS National Ambient Air Quality Standards 

NCDAQ North Carolina Division of Air Quality 

NCDFR North Carolina Division of Forest Resources 

NCDOT North Carolina Department of Transportation 

NCSU North Carolina State University 

NEI National Emissions Inventory 

NG Natural Gas 

NH3 Ammonia 

NOx Nitrogen Oxides 

PM Particulate Matter 

QA Quality Assurance 

SCC Source Classification Code 

SIC Standard Industrial Classification 

SO2 Sulfur dioxide 

USEPA U.S. Environmental Protection Agency 

USFA U.S. Fire Administration 

USFWS U.S. Fish and Wildlife Service 

USFS U.S. Forest Service 

VMT Vehicle Miles Traveled 

VOC Volatile Organic Compounds 
Area Sources Documentation 1 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

1

1. INTRODUCTION AND SCOPE 

Area sources represent a collection of many small, unidentified points of air pollution emissions 

within a specified geographical area, emitting less than the minimum level prescribed for 

permitted point sources. Because these sources are too small and/or too numerous to be 

surveyed and characterized individually, all area source activities are collectively estimated. The 

county is usually the geographic area for which emissions from area sources are compiled, 

primarily because counties are the smallest areas for which data used for estimating emissions is 

readily available. 

The area source inventories detailed in this section have been developed for the Hickory and 

Greensboro/Winston-Salem/High Point (referred to as the Triad area) annual fine particulate 

matter (PM2.5) nonattainment areas as part of the process of redesignating the areas from 

nonattainment to attainment/maintenance for the annual PM2.5 standard. The Hickory 

nonattainment area consists of Catawba County and the Triad nonattainment area consists of 

Davidson and Guilford Counties. Table 1-1 and 1-2 below shows a summary of the area source 

total emissions for each nonattainment area. All emissions are calculated on a ton per year basis. 

Table 1-1 Hickory Nonattainment Area Source Emissions 

2008 2011 2014 2017 2021 

NOx 662 614 566 520 454 

SO2 2,263 2,037 1,808 1,580 1,277 

PM2.5 682 658 629 606 559 

Table 1-2 Triad Nonattainment Area Source Emissions 

2008 2011 2014 2017 2021 

NOx 1,826 1,761 1,693 1,632 1,537 

SO2 5,112 4,743 4,375 4,008 3,517 

PM2.5 1,769 1,692 1,603 1,528 1,382 

 
Area Sources Documentation 2 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

2

2.0 OVERALL METHODOLOGY 

2.1 Source Category Identification 

The area source categories were identified from U. S. Environmental Protection Agency’s 

(USEPA’s) guidance document EPA-450/4-91-016, Procedures for the Preparation of Emission 

Inventories of Carbon Monoxide and Precursors of Ozone, Vol. 1, from this point on this 

document will be referred to as the Procedures document; the USEPA guidance document EPA454/R-05-001, Emissions Inventory Guidance for Implementation of Ozone and Particulate 

Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulation; the 

Emissions Inventory Improvement Program (EIIP) Technical Reports, Volume 3, Area Sources

as of December 2002 (the most current version at the time of the inventory development), from 

this point on this document will be referred to as EIIP Tech Reports. 

2.2 Area Source Emission Estimation Approach 

Area source emissions are estimated by multiplying an emission factor by some known indicator 

of collective activity for each source category within the inventory area. An indicator is any 

parameter associated with the activity level of a source that can be correlated with the air 

pollutant emissions from that source, such as production, number of employees, or population. 

In general, one of the following emissions estimation approaches is used to calculate the area 

source emissions: per capita emission factors, employment-related emission factors, commodity 

consumption-related emission factors, and level of activity based emission factors. The emission 

factors used were obtained from the EIIP Tech. Reports, the Procedures document or the 

USEPA’s AP-42 Compilation of Air Pollutant Emission Factors, Fifth Edition, referred to as 

AP-42. 

There are several methods for estimating the activity level for a specific area source category. 

These are: treating area sources as point sources, surveying local activity levels, apportioning 

national or statewide activity totals to local inventory areas, using population or employment 

data. All of these methods were used to estimate area source emissions. For some source 

categories, 2007 activity data was the latest data available so it was used to estimate the 

emissions inventory. 

Some of the area source categories utilize population for the emissions estimation. The base year 

(2008) and future year population projections, for years 2011, 2014, 2017 and 2021, were
Area Sources Documentation 3 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

3

obtained from the NC Office of State Budget and Management (OSBM) website 

(www.osbm.state.us.nc). The population for each county is shown in Table 2.2-1 below. 

Table 2.2-1 Total County Population 

Year Catawba Davidson Guilford 

2008 154,972 158,897 468,439 

2011 161,146 166,082 493,237 

2014 167,351 173,813 518,129 

2017 173,556 181,519 543,021 

2021 181,829 191,758 576,210 

There are a few categories that utilize the rural portion of the total county population. The rural 

population was determined by multiplying the rural population percentage as reported in the 

2000 census, by the total county population (Table 2.2-1). Table 2.2-2 below shows the rural 

population percentage and Table 2.2-3 shows the rural portion of the county total. 

Table 2.2-2 2000 Census Rural Population Percentages 

COUNTY Rural Population 

Percentage 

Catawba 35.1% 

Davidson 56.9% 

Guilford 16.2% 

Table 2.2-3 2008 Rural Population 

COUNTY Rural Population 

Catawba 54,395 

Davidson 90,412 

Guilford 75,887 

There are a number of categories where emissions were calculated with emission factors based 

on employment. The employment numbers were obtained from the on-line U.S. Census Bureau 

County Business Patterns at the county level for North Carolina. 
Area Sources Documentation 4 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

4

Certain emission categories were adjusted for such things as rule effectiveness and rule 

penetration. These are discussed in the particular source categories descriptions. 

For creating future year emission estimates for many source categories, the base year emissions 

inventory was projected with a source category specific growth factor generated with the 

USEPA’s Economic Growth Analysis System version 5.0 (E-GAS 5.0) program. 

For certain categories, there can be overlap between the point source emissions and the area 

source emissions calculated with emission factors. The point source emissions in these 

categories were identified so that they could be subtracted where appropriate. 

 
Area Sources Documentation 5 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

5

3. QUALITY ASSURANCE OF EMISSIONS INVENTORY 

Many emission estimation methods are based on AP-42 factors, located on the USEPA website 

at http://www.epa.gov/ttn/chief/ap42/, factors given in the Procedures document, and factors 

given in the documents of the Emission Inventory Improvement Program website located at 

http://www.epa.gov/ttn/chief/eiip/. Sources of error would primarily be associated with 

multiplier values, data entry errors, and the accuracy of formulas. 

Under the direction of the quality assurance coordinator, emission sources whose contribution 

was either at the high or low end of the range of estimates were scrutinized more closely for 

reasonableness. The accuracy was addressed by performing independent checks of the 

calculations. In addition, the raw data used in the calculations were verified to make sure 

transference to the spreadsheets was accomplished accurately. Furthermore, the formulas used to 

calculate the emissions were reviewed and checked for correctness. Random independent checks 

of the calculations were also performed to ensure the accuracy of the inventory. 
Area Sources Documentation 6 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

6

4. DISCUSSION OF AREA SOURCE CATEGORIES 

Area sources represent a collection of many small, unidentified points of air pollution emissions 

within a specified geographical area, emitting less than the minimum level prescribed for 

permitted point sources. Because these sources are too small and/or too numerous to be 

surveyed and characterized individually, all area source activities are collectively estimated. The 

county is the geographic area for which emissions from area sources are compiled, primarily 

because counties are the smallest areas for which data used for estimating emissions is readily 

available. Volatile organic compounds (VOC) and ammonia (NH3) emissions have been deemed 

insignificant for the Hickory and Triad nonattainment areas therefore, only the source categories 

that emit PM2.5, nitrogen oxides (NOx) and sulfur dioxide (SO2) emissions were calculated. 

Emissions are calculated on an annual basis in tons per year. 

4.1 Forest Fires 

There are two types of forest fires; wild fires, which are accidental or felonious fires and 

prescribed burns, which are intentionally set for the purpose of forest and/or grassland 

management practice. The number of acres burned in 2008 for wild fires were ascertained from 

the North Carolina Division of Forest Resources (NCDFR) and are listed in Table 4.1-1. 

Table 4.1-1 Acres of Land Burned by Wild Fires 

 Total Number 

of Wild Fires 

Catawba 2,378 

Davidson 680 

Guilford 1,114 

The makeup of the plant life burned in each fire can vary from woodland to brush to grassland. 

The emission factors for the southern region of the United States from AP-42, Section 13.1, were 

used to estimate the emissions from forest burns. The emission factors are 17 pounds per ton for 

total particulate matter per unit mass of forest fuel consumed and 4 pounds per ton NOx per unit 

mass of forest fuel consumed. According to AP-42, the SO2 emissions for wild fires are 

negligible. The fuel loading consumed (mass of forest fuel per unit land are burned) for the 

southern region is 9 tons per acre. 

For the base year 2008 and future year emission inventories, it is assumed that the number of 

acres burned remains relatively constant and therefore the emissions do not change from year to 

year. 
Area Sources Documentation 7 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

7

The emissions for 2008 were calculated using Equation 4.1-1. 

EMP = (# acres burned) x EFP x L 4.1-1 

where EMP = emissions for source category for pollutant (P) 

EFP = emission factor for pollutant (P) 

L = fuel loading consumed = 9 ton/acre 

The PM2.5 and NOx emission estimates, in tons/year, from wildfires for the Hickory and Triad 

nonattainment area are listed in Table 4.1-2. 

Table 4.1-2 Emissions from Wildfires 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 43 43 43 43 43

 

Triad Area 

Davidson 12 12 12 12 12

Guilford 20 20 20 20 20

Triad Total 32 32 32 32 32

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 182 182 182 182 182

 

Triad Area 

Davidson 52 52 52 52 52

Guilford 85 85 85 85 85

Triad Total 137 137 137 137 137
Area Sources Documentation 8 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

8

The US Forest Service provided prescribed fires emissions for the federally owned lands in 

Davidson County. The U.S. Forest Service used the CONSUME 3.0 model to calculate the 

prescribed fires emissions for PM2.5 emissions. The CONSUME 3.0 model does not calculate 

NOx emissions therefore, NOx emission factor outlined in AP-42, Section 13.1 was used to 

determine the NOx emissions. 

The NCDFR had 5 prescribed burns in Davidson County and 1 prescribed burn in Guilford 

County. There were no prescribed burns in Catawba County. The NCDFR supplied the number 

of acres and tons burned in Davidson and Guilford Counties for these prescribed fires as shown 

in Table 4.1-3 below. The emissions for the prescribed burns were determined using equation 

4.1-1. The following table illustrates the number of acres and tons burned per county. 

Table 4.1-3 Acres and Tons Burned from the NCDFR Prescribed Fires 

County Acres Burned Tons Burned

Davidson 362 1,823

Guilford 25 125

The emissions for Davidson and Guilford Counties from prescribed fires are shown in 

Table 4.1-4 below. 

Table 4.1-4 Emissions from Prescribed Fires 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Triad Area 

Davidson 155 155 155 155 155

Guilford 0 0 0 0 0

Triad Total 155 155 155 155 155

Total PM2.5 Emissions (tons/year) 

Triad Area 

Davidson 380 380 380 380 380

Guilford 1 1 1 1 1

Triad Total 381 381 381 381 381

4.2 Structure Fires 

Burning fires can produce short term emissions of organic compounds and NOx. The U.S. Fire 

Administration (USFA) of the Department of Homeland Security maintains statistics on the 

number of fires nationally. The number of fires per person per year was derived from 2008 

national population statistics and 2008 USFA national fire statistics. The USFA 2008 fire 
Area Sources Documentation 9 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

9

structures statistics were obtained from the USFA website at http://www.USFA.DHS.gov/statistics/. 

A fires per person per year factor was calculated based on the number of national structure fires 

and U.S. population equating to 0.00133 fires/person/year. The 2008 county population values 

are shown in Table 2.2-1. The 0.00133 fires per person per year was applied to the 2008 

population for each county to determine the number of fires in each county for 2008. 

The emission factors and fuel loading factors were obtained from the EIIP Tech. Reports, 

Table 18.4-1 and Table 18.4-2, respectively. The emission factors are 11 pounds of VOC per ton 

burned, 1.4 pounds of NOx per ton burned, and 10.8 pounds PM2.5 per tons burned. The 

emission factor used for PM2.5 is a conservative estimate based on the total particulate matter. 

The loading factor is 1.15 tons of material burned per structural fire. 

The base year emissions were projected using E-GAS 5.0 growth factors, listed in Table 4.2-1, to 

calculate the future year inventories. 

Table 4.2-1 Growth Factors for Structure Fires 

2011 2014 2017 2120 

0.988 1.017 1.080 1.171 

The emissions for the 2008 base year emissions inventory and future emissions projections were 

calculated using Equations 4.2-1 and 4.2-2, respectively. 

EMP = (2008 County population) x (FPP) x (CF) x (EFP) 

 (2000 lb/tons) 4.2-1 

PJbEMa = EMa x GFab 4.2-2 

where EMP = emissions for structure fires for pollutant (P) 

 FPP = fires per person in 2008, 0.00133 fires/person/year 

 CF = Conversion factor, 1.15 tons burned/structure fire 

 EFP = emission factor for pollutant (P) 

 PJbEMa = projected future year (b) emissions for county in redesignation area ton/year 

 GFab = growth factor for base year (a) to future year (b) 

The NOx and PM2.5 emissions estimates, in tons/year, from structure fires are listed in 

Table 4.2-2. 
Area Sources Documentation 10 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

10

Table 4.2-2 Emissions from Structure Fire 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year)

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 1 1 1 1 1

Triad Total 1 1 1 1 1

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year)

Hickory Area 

Catawba 3 3 3 3 3

 

Triad Area 

Davidson 2 2 2 2 2

Guilford 6 6 6 6 7

Triad Total 8 8 8 8 9

 
Area Sources Documentation 11 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

11

4.3 Open Burning – Municipal Solid Waste and Yard Trimmings 

This subsection describes the combined emission inventory methodology for residential open 

burning and open burning – yard trimmings. Open burning is treated as a means of waste 

disposal in rural areas. Materials burned generally include agricultural refuse, landscaping 

refuse, or scrap wood. In North Carolina, it is illegal to burn municipal solid waste anywhere in 

the state. However, the North Carolina Division of Air Quality (NCDAQ) realizes that this type 

of burning occurs, so it is included in the emissions inventory. However, rule effectiveness, rule 

penetration and control efficiency factors are applied to the emission estimates. 

It was assumed that all municipal solid waste (MSW) and yard trimmings were burned in the 

open for solid waste generated outside the municipal corporate limits. According to the EIIP 

Tech. Reports, Table 16.5-1, it is estimated that 3.77 pounds of MSW is generated per person per 

day and 0.64 pounds of yard trimmings are generated per person per day. The 2008 rural 

population per county (see Table 2.2-3) was used to apportion the emissions to the county level. 

NOx and SO2 emission factors for open burning of MSW were obtained from EIIP Tech. 

Reports, Table 16.4-1, Open Burning of Municipal Refuse. The emission factors are 34.8 

pounds PM2.5 per ton MSW burned, 6 pounds NOx per ton MSW burned and 1 pound SO2 per 

ton MSW burned. 

The PM2.5 emission factor, 38 pounds PM2.5 per ton yard trimming, for open burning of yard 

trimmings was obtained from EIIP Tech. Reports, Chapter 16, Table 16.4-7. 

The future year emissions inventories were calculated from the base year projections using 

 E-GAS 5.0 growth factors, listed in Table 4.3-2, to calculate the future year emission 

inventories. 

Table 4.3-2 Growth Factors for Open Burning 

2011 2014 2017 2120 

1.042 1.086 1.130 1.188 

The emissions from the burning of municipal solid waste and yard trimmings for the base year 

2008 inventory were calculated using equations 4.3-1 and 4.3-2. The future year emissions 

projections were calculated using equation 4.3-3. 
Area Sources Documentation 12 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

12

EMP,MSW = (Rural Population in 2008) x (CFMSW) x (EFP) x (365 days/year)

 (2000 lb/tons) 4.3-1 

EMP,YT = (Rural Population in 2008) x (CFYT) x (EFP) x (365 days/year)

 (2000 lb/tons) 4.3-2 

PJaEM = EMP x GFa 4.3-3 

where EMP,MSW = emissions from burning MSW for pollutant (P) 

 EMP,YT = emissions from burning yard trimmings for pollutant (P) 

 CFMSW = conversion factor, 3.77 lb MSW/person/day 

 = 0.001885 ton MSW/person/day 

 CFYT = conversion factor, 0.64 lb yard trimmings/person/day 

 = 0.00032 ton yard trimmings/person/day 

 EFP = emission factor for pollutant (P) 

 PJaEM = projected future year (a) emissions for county 

 GFa = growth factor for future year (a) 

Since the NCDAQ has an open burning regulation that prohibits the burning of man-made 

materials, the emissions estimated for MSW were reduced to account for this rule. The control 

efficiency is 100% since no burning yields no emissions. The rule penetration is also 100% 

since the regulation prohibits the burning of man-made materials statewide. Finally the rule 

effectiveness was set to a conservative 50% for the base year since the NCDAQ know that 

burning of man-made materials does occur. The NCDAQ has started an aggressive campaign to 

make the public aware that it is illegal to burn man-made materials. The NCDAQ has sponsored 

radio ads as well as billboard signs in an effort to educate the public. Additionally, the NCDAQ 

has developed an educational video discussing open burning and the State’s regulation. This 

video has been distributed to the fire departments across the State. Finally, at the 2009 North 

Carolina State Fair, the NCDAQ had a booth that allowed staff to talk with the general public 

about the open burning regulations and provide hand outs that discussed what was legal to burn. 

The NCDAQ expects that as the public becomes more aware of the open burning regulations, the 

rule effective will increase to 75% by 2021. A gradual increase in the rule effectiveness for the 

interim years was applied. The table below displays the rule effective numbers used in 

calculating the emissions. 

Table 4.3-3 Rule Effectiveness for MSW Open Burning 

2008 2011 2014 2017 2120 

0.50 0.56 0.62 0.67 0.75 
Area Sources Documentation 13 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

13

The formula used to apply these factors to the emissions estimates is shown below in 

equations 4.3-4 and 4.3-5. 

EMP,MSW,Controlled = (EMP,MSW ) x (1 – (CE x RP x RE)) 4.3-4 

PJaEMControlled = PJaEM x (1 – (CE x RP x RE)) 4.3-5 

where EMP,MSW,Controlled = controlled emissions from burning MSW for pollutant (P) 

 EMP,MSW = emissions from burning MSW for pollutant (P) 

 CE = control efficiency (1) 

 RP = rule penetration 

 RE = rule effectiveness 

 PJaEMControlled = controlled projected future year (a) emissions for county 

 PJaEM = projected future year (a) emissions for county 

The open burning emissions from municipal solid waste and yard trimmings, in tons/year, are 

listed in Table 4.3-4 and Table 4.3-5, respectively. 
Area Sources Documentation 14 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

14

Table 4.3-4 Emissions from Municipal Solid Waste 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 56 51 46 42 33

 

Triad Area 

Davidson 94 86 77 70 56

Guilford 79 72 65 58 47

Triad Total 173 158 142 128 103

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 10 9 8 7 6

 

Triad Area 

Davidson 16 14 13 12 9

Guilford 13 12 11 10 8

Triad Total 29 26 24 22 17

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 326 299 269 243 194

 

Triad Area 

Davidson 541 497 447 404 322

Guilford 454 417 375 339 270

Triad Total 995 914 822 743 592

Table 4.3-5 Emissions from Yard Trimmings 

Pollutant/County 2008 2011 2014 2017 2021 

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 121 126 131 136 143

 

Triad Area 

Davidson 63 65 68 71 75

Guilford 73 76 79 82 86

Triad Total 136 141 147 153 161
Area Sources Documentation 15 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

15

4.4 On-Site Incineration 

On-site incineration is the confined burning of waste leaves, landscape refuse and other refuse or 

rubbish. In North Carolina, commercial/institutional and industrial incinerators are required to 

have an Air Quality Permit in order to operate. Therefore, all industrial incinerators are 

identified in the point source inventory. There may be small commercial/institutional 

incinerators that have not been identified in the point source inventory and as a result emissions 

were calculated for commercial on-site incinerators. 

No data was available to determine the amount of waste burned in on-site incinerators. 

Therefore, the amount of solid waste burned was estimated with the fuel loading factor given in 

Table 4.6-1 of the Procedures document. The commercial fuel loading factor is 0.023 tons of 

refuse/year. The yield for commercial incineration was obtained from several sources. The yield 

of NOx, SO2 and PM2.5 were obtained from AP-42, Table 3.4.7-1 and are listed in Table 4.4-1. 

The yield values used are from the uncontrolled emission factors for refuse combustors other 

than municipal waste. The average value is calculated from the single and multiple chambers 

combustors. 

Table 4.4-1 Yield of Pollutant Values for Uncontrolled Refuse Combustors 

Pollutant 

Multiple Chamber 

Combustor Yield Value 

Single Chamber 

Combustor Yield Value 

Average Yield Value 

(lb pollutant/ton refuse 

burned) 

(lb pollutant/ton refuse 

burned) 

(lb pollutant/ton refuse 

burned) 

NOx 3 2 2.5 

SO2 2.5 2.5 2.5 

PM2.5 7 15 11 

The future year emissions inventories were calculated from the base year projections using 

E-GAS 5.0 growth factors, listed in Table 4.4-2, to calculate the future year inventories. The 

growth factors for on-site incineration are the same as the open burning growth factors. 

Table 4.4-2 Growth Factors for On-Site Incineration 

2011 2014 2017 2120 

1.042 1.086 1.130 1.188 
Area Sources Documentation 16 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

16

The emissions for 2008 were calculated using equation 4.4-1 and the emissions for the future 

years were calculated using equation 4.4-2. 

EMP = (2008 rural population) x (LF) x (EFP) 

 (2000 lb/tons) 4.4-1 

 PJaEM = EMP x GFa 4.4-2 

where EMP = emissions for on-site incineration for pollutant (P) 

 LF = Fuel loading Factory, 0.023 tons refuse burned/person/year 

 EFP = emission factor for pollutant (P) 

 PJaEM = projected future year (a) emissions for county in nonattainment area 

 GFa = growth factor for future year (a) 

The rural population was calculated using the 2000 census data rural population percentage and 

applying the percentage to the total 2008 population, see Table 2.2-2. According to the 

Procedures document, on-site incineration occurs uniformly year round and operates 7 days per 

week. Point source emissions with SCC 5-xx-xxx-xx identified waste incineration emissions. 

The point source emissions in tons per year were subtracted from the on-site incineration source 

emissions. 

The NOx, SO2 and PM2.5 emissions estimates, in tons/year, from on-site incineration for the 

Hickory and Triad nonattainment areas are listed in Table 4.4-3 below. 

 
Area Sources Documentation 17 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

17

Table 4.4-3 Emissions from On-Site Incineration 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 2 2 2 2 2

 

Triad Area 

Davidson 3 3 3 3 3

Guilford 2 2 2 2 3

Triad Total 5 5 5 5 6

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 2 2 2 2 2

 

Triad Area 

Davidson 3 3 3 3 3

Guilford 2 2 2 2 3

Triad Total 5 5 5 5 6

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 7 7 7 8 8

 

Triad Area 

Davidson 11 12 12 13 14

Guilford 10 10 10 11 11

Triad Total 21 22 22 24 25

4.5 Vehicle Fires 

Vehicle fire emissions are estimated by considering the estimated number vehicles burned in the 

state, the amount of material burned (the fuel loading) in a vehicle fire and the emission factors 

for the open burning of automobile components. The assumptions for amount of material burned 

and the emission factors were based on the USEPA’s AP-42, Section 2.5 Open Burning. 

The estimated number of vehicle fires was determined by apportioning a national fire statistic to 

a county level. The USFA of the Department of Homeland Security maintains national-level fire 

statistics. The number of vehicle fires nationwide in 2008 was 236,000 and was available from 

the USFA website at http://www.USFA.DHS.gov/statistics. The number of national-level 

vehicle fires was then apportioned to a state-level. The ratio of North Carolina vehicle miles 
Area Sources Documentation 18 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

18

traveled (VMT) to national VMT (103,598,000,000 VMT / 3,029,822,000,000 VMT) was 

applied to the number of national-level vehicle fires to obtain the number of North Carolina 

vehicle fires. The latest VMT information available for both the U.S. and the state is 2007. The 

U.S. and state VMT statistics were obtained from the U.S. Department of Transportation, Federal 

Highway Administration website at http://www.fhwa.dot.gov/policy/ohim/hs02/vm2.htm/. The 

number of state-level vehicle fires was then apportioned to a county level based on the 2008 

VMT per county as shown in Table 4.5-1 through 4.5-3. The 2008 county level VMT was 

obtained from the NC Department of Transportation. The future year VMT was projected using 

the E-GAS 5.0 model. 

Table 4.5-1 Catawba County Vehicle Miles Traveled 

Functional Class 2008 2011 2014 2017 2021 

Urban Interstate 1,205,670 1,308,253 1,411,432 1,500,373 1,582,047

Urban Freeway or Expressway 380,969 409,388 438,016 486,265 544,270

Urban Other Principal Arterial 1,011,546 1,065,527 1,120,100 1,169,246 1,215,533

Urban Minor Arterial 1,034,709 1,091,506 1,148,770 1,203,608 1,257,116

Urban Collector 321,682 349,200 376,848 402,304 426,633

Urban Local 345,449 374,445 403,850 434,283 465,128

Rural Interstate 74,268 80,041 85,894 92,054 98,345

Rural Other Principal Arterial 237,359 259,937 282,672 305,641 328,686

Rural Minor Arterial 173,455 186,022 198,828 212,146 225,658

Rural Major Collector 124,618 136,729 148,958 160,789 172,393

Rural Minor Collector 250,040 274,203 298,590 321,380 343,315

Rural Local 112,023 120,945 129,990 139,866 150,126

County Total 5,271,788 5,656,196 6,043,948 6,427,955 6,809,250

 
Area Sources Documentation 19 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

19

Table 4.5-2 Davidson County Vehicle Miles Traveled 

Functional Class 2008 2011 2014 2017 2021 

Urban Interstate 738,564 792,268 829,522 867,483 896,320

Urban Freeway or Expressway 605,434 642,240 701,206 747,071 774,221

Urban Other Principal Arterial 672,579 702,058 717,232 746,199 775,827

Urban Minor Arterial 559,623 588,731 611,477 638,368 660,838

Urban Collector 268,511 295,687 315,138 329,927 338,628

Urban Local 359,726 380,817 400,646 418,693 433,307

Rural Interstate 461,013 472,863 495,240 517,551 532,790

Rural Other Principal Arterial 152,576 149,062 153,229 157,698 157,735

Rural Minor Arterial 408,314 422,673 443,420 476,148 508,971

Rural Major Collector 405,273 413,706 430,398 447,189 458,056

Rural Minor Collector 295,215 310,307 324,936 336,649 342,295

Rural Local 377,797 400,311 420,952 435,963 446,836

County Total 5,304,625 5,570,723 5,843,396 6,118,939 6,325,824

Table 4.5-3 Guilford County Vehicle Miles Traveled 

Functional Class 2008 2011 2014 2017 2021 

Urban Interstate 3,985,564 4,419,157 4,865,961 5,227,576 5,571,494

Urban Freeway or Expressway 2,251,352 2,452,593 2,613,197 2,905,078 3,275,829

Urban Other Principal Arterial 2,368,151 2,477,254 2,591,662 2,679,083 2,747,293

Urban Minor Arterial 2,727,044 2,837,423 3,012,805 3,147,788 3,247,375

Urban Collector 1,368,123 1,452,017 1,570,260 1,645,148 1,686,518

Urban Local 780,183 815,646 847,770 878,533 907,949

Rural Interstate 989,050 1,090,492 1,229,196 1,351,896 1,457,378

Rural Other Principal Arterial 513,834 545,289 546,548 567,373 595,658

Rural Minor Arterial 244,663 273,514 278,683 287,233 300,400

Rural Major Collector 776,249 838,619 898,783 941,639 980,181

Rural Minor Collector 360,879 393,534 420,122 448,880 480,975

Rural Local 411,379 435,206 655,193 721,391 663,260

County Total 16,776,471 18,030,744 19,530,180 20,801,618 21,914,310

The amount of vehicle material burned (the fuel loading) in a vehicle fire was estimated by 

assuming that an average vehicle has 500 pounds of components (0.25 tons) that can burn in a 

fire, based on a 3,700 pounds average vehicle weight (CARB, 1995). 
Area Sources Documentation 20 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

20

The emission factors were obtained from AP-42, Section 2.5 Open Burning, Table 2.5-1, 

Emission Factors for Open Burning of Municipal Refuse for automobile components. The 

emission factors are 100 pounds of PM2.5 per ton burned and 4 pounds of NOx per ton burned. 

The emission factor for PM2.5 is a conservative estimate based on the total particulate matter. 

The future year inventories were grown from the 2008 base year emissions using growth factors 

generated by the E-GAS 5.0 model. These growth factors are listed in Table 4.5-4 below. 

Table 4.5-4 Growth Factors for Vehicle Fires 

2011 2014 2017 2021 

0.988 1.017 1.080 1.171 

The emissions for the base inventory and future year projections were calculated using equation 

4.5-1 and 4.5-2, respectively. 

EMP = (# of Vehicle Fires per year) x (CF) x (EFP) 

 (2000 lb/tons) 4.5-1 

PJaEM = EMP x GFa 4.5-2 

where EMP = annual emissions for structure fires for pollutant (P) 

 CF = Conversion factor, 0.25 tons burned/vehicle fire 

 EFP = emission factor for pollutant (P) 

 PJaEM = projected future year (a) emissions per county 

 GFa = growth factor for future year (a) 

The PM2.5 and NOx emission estimates, in tons/year, from vehicle fires for the Hickory and 

Triad nonattainment areas are listed in Table 4.5-3. 

 
Area Sources Documentation 21 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

21

Table 4.5-5 Emissions from Vehicle Fires 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

The emissions generated from vehicle fires are negligible for both of the nonattainment areas. 

4.6 Small Stationary Source Fossil Fuel Use 

This source category covers NOx, SO2, and PM2.5, emissions from natural gas (NG) and liquid 

petroleum gas (LPG), oil, coal, and wood combustion in the residential, commercial/institutional 

(referred to as commercial) and industrial sectors. 

The “demand for energy” for these fuel types is known as fuel usage. Fuel usage data for North 

Carolina was obtained from the U.S. Department of Energy, Energy Information Administration 

(EIA) website for fuel consumption. The latest fuel usage data available from EIA is 2007. The 
Area Sources Documentation 22 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

22

emissions estimates for 2008 are conservative because of the current economic downturn 

resulting in commercial and industrial sources closing. This is further substantiated by the 

decrease in the manufacturing employment (Table 4.6-6) as reported by the U.S. Census Bureau. 

The following table shows the fuel usage for the residential, commercial and industrial sectors. 

Table 4.6-1 2007 Fuel Use in North Carolina 

Fuel Units Residential Commercial Industrial 

Natural Gas 106 ft3 58,909 45,861 89,289 

LPG gallons 239,256,678 41,811,847 184,668,990 

Oil gallons 117,527,897 66,949,824 295,999,749 

Coal tons 4,447 40,020 0 

Wood tons 1,466,667 233,333 6,633,333 

The emission factors used to calculate the fuel oil, NG, LPG and coal combustion emissions 

were obtained from the NCDAQ permits emissions calculations spreadsheets found on-line at 

http://daq.state.nc.us/permits/spreadsheets/. The emission factors used in the permits emissions 

calculations were derived from AP-42. 

For the coal combustion commercial source sector, an average for the spreader stoker, overfeed 

stoker and underfeed stoker emission factors were calculated and the average emission factor 

was used to calculate the commercial coal combustion emissions. The emissions factors used for 

commercial and industrial source categories for natural gas are for uncontrolled emissions of 

small boilers (<100 MMBtu/hr). For the residential source category for natural gas, the emission 

factors for uncontrolled residential furnaces were used for the emissions calculations. The 

emission factors for commercial propane were used for the LPG residential source category 

because the AP-42 does not list a separate emission factor for residential LPG combustion. 

Propane and butane emission factors were averaged for the LPG commercial and industrial 

source categories. 

The only source sector that contains emissions for wood combustion is residential. The emission 

factors for the residential source category were derived from EIIP Tech. Reports, Table 2.4-1. 

 
Area Sources Documentation 23 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

23

The emission factors used are shown in Table 4.6-2 below. 

Table 4.6-2 Fuel Combustion Emission Factors 

Fuel Units NOx SO2 PM2.5

Residential

NG lb/106 ft3 94 0.6 7.6 

LPG lb/gal 0.013 0.00002 0.0007 

Oil lb/gal 0.018 0.298 0.000168 

Coal lb/ton 9.1 34.1 3.8 

Wood lb/ton 2.6 0.4 0 

Commercial

NG lb/106 ft3 100 0.6 7.6 

LPG lb/gal 0.014 0.000017 0.00075 

Oil lb/gal 0.033875 0.31605 0.002761 

Coal lb/ton 9.3 39.2 3.5 

Industrial

NG lb/106 ft3 100 0.6 7.6 

LPG lb/gal 0.014 0.000017 0.00075 

Oil lb/gal 0.033875 0.31605 0.002761 

The residential source category for all of the small stationary combustion sources fuel usage for 

the Hickory and Triad nonattainment areas were calculated by apportioning the state total fuel 

usage to a county level. Fuel usage was apportioned by applying the ratio of the number of 

households heated with the appropriate fuel type in a county to the total households in the state 

heated with the appropriate fuel type, see equation 4.6-1 below. 

# gal. fuel per County = (# gal. fuel for State) x (# housing units heated by fuel per County) 4.6-1 

 (# housing units heated by fuel in State) 

The number of households heated with fuel oil, coal, NG, LPG and wood was obtained from the 

U.S. Census Bureau. The latest fuel use data available was 2007. The number of households 

heated per fuel type is shown in Table 4.6-3. 

 
Area Sources Documentation 24 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

24

Table 4.6-3 Residential Fuel Apportionment 

Number of Households per Fuel Type 

County Fuel Oil Coal Natural Gas LPG Wood 

Catawba 5,223 0 12,831 3,012 1,047 

Davidson 9,255 0 8,672 4,064 1,551 

Guilford 7,529 0 82,862 8,964 1,561 

North Carolina 271,482 406 890,790 383,823 70,715 

Commercial and industrial fuel usage was apportioned according to the number of employees in 

the commercial/industrial business establishments in the state and nonattainment counties. The 

employment data was obtained from the County Business Patterns for the source industrial 

classification (SIC) codes 31 (manufacturing), 42 (wholesale trade) and 44 (retail trade) for 

2007, the latest employment data available. The number of employees for these establishments 

was used to represent the commercial and industrial source categories. The apportionment 

numbers are shown in Table 4.6-4 below. 

Table 4.6-4 Commercial and Industrial Fuel Apportionment 

Total Employees 

Catawba 45,510 

Davidson 19,221 

Guilford 88,712 

North Carolina 1,167,586 

To yield more accurate emissions projections for these categories, the future emissions estimates 

were apportioned using county population for the residential source sector and manufacturing 

employment data for the commercial and industrial source sectors. 

For the residential source sectors, the growth factors are based upon the population for each 

county. The population for each county is shown in Table 2.2-2. The growth factors were 

developed based on the ratio of the base year (2008) population to the future years (2011, 2014, 

2017 and 2021) population, see equation 4.6-2 below. 

Residential Growth Factors = FYpop 4.6-2 

 BYpop 

where BYpop = 2008 population per county 

 FYpop = future year population per county 
Area Sources Documentation 25 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

25

Table 4.6-5 below shows the residential growth factors for each county. 

Table 4.6-5 Residential Growth Factors for Fuel Combustion 

Source Category 2011 2014 2017 2021 

Catawba 1.040 1.080 1.120 1.174 

Davidson 1.045 1.094 1.143 1.207 

Guilford 1.053 1.106 1.159 1.230 

The manufacturing (SIC 31), wholesale trade (SIC 42) and retail trade (SIC 44) establishments 

were used to represent the employment data for the commercial and industrial source sectors. 

The same methodology used to develop the future year population data, using the FORECAST 

function in Microsoft EXCEL, was employed to calculate the future year employment data. The 

table below shows the employment data. 

Table 4.6-6 Manufacturing Employment per County 

Year Catawba Davidson Guilford 

2003 52,160 22,519 93,653 

2004 49,738 22,313 94,958 

2005 48,449 20,839 91,400 

2006 48,072 19,689 89,121 

2007 45,510 19,221 88,712 

2008 44,296 18,150 86,853 

2011 39,806 15,384 82,137 

2014 35,316 12,618 77,422 

2017 30,827 9,852 72,706 

2021 24,840 6,164 66,418 

The growth factors were developed based on the ratio of the base year (2008) employment to the 

future years (2011, 2014, 2017 and 2021) employment, see equation 4.6-3 below. 

Commercial/Industrial Growth Factors = FYemp 4.6-3 

 BYemp 

where BYemp = 2008 employment per county 

 FYemp = future year employment per county 
Area Sources Documentation 26 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

26

Based on the manufacturing employment data in Table 4.6-6 above, the commercial and 

industrial growth factors for each county are shown in Table 4.6-7 below. 

Table 4.6-7 Commercial/Industrial Growth Factors for Fuel Combustion 

Source Category 2011 2014 2017 2021 

Catawba 0.8986 0.7973 0.6959 0.5608 

Davidson 0.8476 0.6952 0.5428 0.3396 

Guilford 0.9457 0.8914 0.8371 0.7647 

The emissions for the 2008 base year emissions inventory for each small stationary combustion 

source were calculated using Equations 4.6-4 – 4.6-8. 

Coal EMP = (# tons/year Coal) x EFCoal(P) 4.6-4 

 (2000 pounds/ton) 

NG EMP = (# ft3/year NG) x EFNG(P) 4.6-5 

 (2000 pounds/ton) 

LPG EMP = (# gal/year LPG) x EFLPG(P) 4.6-6 

 (2000 pounds/ton) 

Fuel Oil EMP = (# gal/year Fuel Oil) x EFOil(P) 4.6-7 

 (2000 pounds/ton) 

Wood EMP = (# ton/year Wood) x EFWood(P) 4.6-8 

 (2000 pounds/ton) 

where Coal EMP = annual emissions for coal combustion for pollutant (P) 

 NG EMP = annual emissions for NG combustion for pollutant (P) 

 LP EMP = annual emissions for LPG combustion for pollutant (P) 

 Fuel Oil EMP = annual emissions for fuel oil combustion for pollutant (P) 

 Wood EMP = annual emissions for wood combustion for pollutant (P) 

 EF(Coal)P = emission factor for coal combustion for pollutant (P) 

 EF(NG)P = emission factor for NG combustion for pollutant (P) 

 EF(LPG)P = emission factor for LPG combustion for pollutant (P) 

 EF(Oil)P = emission factor for fuel oil combustion for pollutant (P) 

 EF(Wood)P = emission factor for wood combustion for pollutant (P) 

The emissions for the future year projections for each small stationary combustion source were 

calculated using Equation 4.6-9. 
Area Sources Documentation 27 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

27

PJbEMa = EMa x GFab 4.6-9 

where PJbEM = projected future year (b) emissions per county 

 GFab = growth factor for base year (a) to future year (b) 

The NOx, SO2 and PM2.5 emissions estimates for each fuel combustion source, in tons/year, for 

the residential source sector are listed in Tables 4.6-8 through 4.6-11. Based on U.S. Census 

Bureau data, Catawba, Davidson and Guilford Counties do not use coal as a means of residential 

heating therefore, there are no emissions estimates for coal combustion in the residential source 

sector. There are no PM2.5 emissions for wood combustion because the EIIP Tech. Reports, 

Table 2.4-1 does not have an emission factor for PM2.5 for residential wood combustion. 

Table 4.6-8 Residential Source Sector Fuel Oil Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 20 21 22 23 24

 

Triad Area 

Davidson 36 38 39 41 44

Guilford 29 31 32 34 36

Triad Total 65 69 71 75 80

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 5 5 5 5 6

 

Triad Area 

Davidson 9 9 9 10 10

Guilford 7 7 8 8 9

Triad Total 16 16 17 18 19

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 2 2 2 2 2

 

Triad Area 

Davidson 3 3 3 3 3

Guilford 2 2 3 3 3

Triad Total 5 5 6 6 6
Area Sources Documentation 28 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

28

Table 4.6-9 Residential Source Sector LPG Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 9 10 10 10 11

 

Triad Area 

Davidson 15 16 17 17 18

Guilford 5 5 5 6 6

Triad Total 20 21 22 23 24

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 0 1 1 1 1

 

Triad Area 

Davidson 1 1 1 1 1

Guilford 0 0 0 0 0

Triad Total 1 1 1 1 1

 
Area Sources Documentation 29 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

29

Table 4.6-10 Residential Source Sector NG Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 40 41 43 45 47

 

Triad Area 

Davidson 27 28 29 31 33

Guilford 258 271 285 299 317

Triad Total 285 299 314 330 350

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 2 2 2 2 2

Triad Total 2 2 2 2 2

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 3 3 3 4 4

 

Triad Area 

Davidson 2 2 2 2 3

Guilford 21 22 23 24 26

Triad Total 23 24 25 26 29

 
Area Sources Documentation 30 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

30

Table 4.6-11 Residential Source Sector Wood Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 28 29 30 32 33

 

Triad Area 

Davidson 42 44 46 48 50

Guilford 42 44 47 49 52

Triad Total 84 88 93 97 102

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 4 5 5 5 5

 

Triad Area 

Davidson 6 7 7 7 8

Guilford 6 7 7 8 8

Triad Total 12 14 14 15 16

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

The NOx, SO2 and PM2.5 emissions estimates for each fuel combustion source, in tons/year, for 

the commercial and industrial source sectors are listed in Tables 4.6-12 through 4.6-18. There 

are no wood combustion emissions estimates for the commercial and industrial source sectors 

because the only emission factors for wood combustion is residential furnaces which are 

captured in the emissions estimates in the residential source sector. Additionally, there are no 

coal combustion emissions for the industrial source sector because the emissions generated from 

coal are accounted for in the point sources inventory. 

Point sources are those stationary sources that require an Air Permit to operate. In general, these 

sources have a potential to emit more than 5 tons per year of CO, NOx, PM, SO2 and/or VOC 
Area Sources Documentation 31 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

31

from a single facility. Point source emissions with SCC 1-03-002-XXX are identified as 

commercial coal combustion sources and were deducted from the commercial source sector 

emissions. Additionally, NG point sources with SCC 1-03-006-XXX and 1-02-006-XXX, 

commercial and industrial NG combustion sources, respectively, were deducted from the 

commercial and industrial source sectors emissions. The latest available point source emissions 

data is 2007. Tables 4.6-20 – 4.6-23 illustrates the point source emissions that were deducted 

from the commercial coal, commercial fuel oil and commercial NG sources as well as the 

industrial fuel oil and industrial NG sources. 

Table 4.6-12 Commercial Coal Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 6 6 5 5 4

 

Triad Area 

Davidson 3 3 2 2 1

Guilford 14 13 13 12 11

Triad Total 17 16 15 14 12

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 28 26 23 20 16

 

Triad Area 

Davidson 13 11 9 7 4

Guilford 60 56 53 50 46

Triad Total 73 67 62 57 50

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 2 2 2 2 1

 

Triad Area 

Davidson 1 1 1 1 0

Guilford 5 5 5 5 4

Triad Total 6 6 6 6 4

 
Area Sources Documentation 32 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

32

Table 4.6-13 Commercial Fuel Oil Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 43 38 34 30 24

 

Triad Area 

Davidson 16 14 11 9 5

Guilford 84 80 75 71 65

Triad Total 100 94 86 80 70

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 407 366 324 283 228

 

Triad Area 

Davidson 172 146 120 94 59

Guilford 800 756 713 669 611

Triad Total 972 902 833 763 670

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 4 3 3 2 2

 

Triad Area 

Davidson 1 1 1 1 0

Guilford 7 7 6 6 5

Triad Total 8 8 7 7 5

 
Area Sources Documentation 33 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

33

Table 4.6-14 Commercial LPG Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 2 1 1 1 1

Guilford 0 0 0 0 0

Triad Total 2 1 1 1 1

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

 
Area Sources Documentation 34 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

34

Table 4.6-15 Commercial NG Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 69 62 55 48 39

 

Triad Area 

Davidson 31 26 22 17 11

Guilford 131 124 117 110 100

Triad Total 162 150 139 127 111

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 1 1 1 1 1

Triad Total 1 1 1 1 1

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 5 5 4 4 3

 

Triad Area 

Davidson 2 2 2 1 1

Guilford 11 11 10 9 9

Triad Total 13 13 12 10 10

 
Area Sources Documentation 35 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

35

Table 4.6-16 Industrial Fuel Oil Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 190 171 152 132 107

 

Triad Area 

Davidson 81 69 56 44 27

Guilford 321 304 286 269 245

Triad Total 402 373 342 313 272

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 1,806 1,623 1,440 1,257 1,013

 

Triad Area 

Davidson 764 648 531 415 260

Guilford 3,236 3,060 2,885 2,709 2,475

Triad Total 4,000 3,708 3,416 3,124 2,735

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 15 14 12 11 9

 

Triad Area 

Davidson 7 6 5 4 2

Guilford 0 0 0 0 0

Triad Total 7 6 5 4 2

 
Area Sources Documentation 36 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

36

Table 4.6-17 Industrial LPG Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year)

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 7 6 5 4 2

Guilford 0 0 0 0 0

Triad Total 7 6 5 4 2

SO2 Emissions (tons/year)

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

PM2.5 Emissions (tons/year)

Hickory Area 

Catawba 0 0 0 0 0

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 0 0 0 0 0

Triad Total 0 0 0 0 0

 
Area Sources Documentation 37 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

37

Table 4.6-18 Industrial NG Combustion Emissions 

Pollutant/County 2008 2011 2014 2017 2021 

NOx Emissions (tons/year) 

Hickory Area 

Catawba 156 140 124 108 87

 

Triad Area 

Davidson 59 50 41 32 20

Guilford 257 243 229 215 196

Triad Total 316 293 270 247 216

SO2 Emissions (tons/year) 

Hickory Area 

Catawba 1 1 1 1 1

 

Triad Area 

Davidson 0 0 0 0 0

Guilford 2 2 1 1 1

Triad Total 2 2 1 1 1

PM2.5 Emissions (tons/year) 

Hickory Area 

Catawba 12 11 10 8 7

 

Triad Area 

Davidson 5 4 3 2 2

Guilford 22 21 20 19 17

Triad Total 27 25 23 21 19

 
Area Sources Documentation 38 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

38

Table 4.6-19 Point Source Commercial Coal Combustion Emissions 

Hickory Area NOx PM2.5 SO2

Catawba 1 0 2

 

Triad Area 

Davidson 0 0 0

Guilford 0 0 0

Triad Total 0 0 0

Total 1 0 2

Table 4.6-20 Point Source Commercial Fuel Oil Combustion Emissions 

Hickory Area NOx PM2.5 SO2

Catawba 2 0 5

 

Triad Area 

Davidson 3 0 2

Guilford 2 0 4

Triad Total 5 0 6

Total 7 0 11

Table 4.6-21 Point Source Commercial Natural Gas Combustion Emissions 

Hickory Area NOx PM2.5 SO2

Catawba 21 1 0

 

Triad Area 

Davidson 7 1 2

Guilford 43 2 0

Triad Total 50 3 2

Total 71 4 2
Area Sources Documentation 39 

Hickory and Greensboro/Winston-Salem/High Point Annual PM2.5 Appendix C.2 

Redesignation Demonstration and Maintenance Plan December 18, 2009 

39

Table 4.6-22 Point Source Industrial Fuel Oil Combustion Emissions 

Hickory Area NOx PM2.5 SO2

Catawba 5 0 17

 

Triad Area 

Davidson 2 0 6

Guilford 60 148 318

Triad Total 62 148 324

Total 67 148 341

Table 4.6-23 Point Source Industrial Natural Gas Combustion Emissions 

Hickory Area NOx PM2.5 SO2

Catawba 18 1 0

 

Triad Area 

Davidson 15 1 0

Guilford 83 3 0

Triad Total 98 4 0

Total 116 5 0