United States
Environmental Protection
Agency
EPA-600-R-92-001
January 1992
Research and
Development
DOCUMENTATION
OF AIRS AMS
NATIONAL METHODOLOGIES
Prepared for
Prepared by
Air and Energy Engineering Research
Laboratory
Research Triangle Park NC 27711
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EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600-R-92-001
January 1992
DOCUMENTATION OF AIRS AMS
NATIONAL METHODOLOGIES
Final Report
by
E. Sue Kimbrough
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Prepared for:
U. S. Environmental Protection Agency U.S Environmental Protection Agency
Office of Air Quality Planning and Standards Office of Research and Development
Research Triangle Park, North Carolina 27711 Washington, D.C. 20460
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FOREWORD
The document describes the area and mobile source emission estimation procedures that will be
used by the national component of the Aerometric Information Retrieval System (AIRS) Area and
Mobile Source Subsystem (AMS) to generate emissions estimates for area and mobile source
categories for all areas of the U.S. - non-attainment and attainment. While this document is not one of
the official State Implementation Plan (SIP) emission inventory guidance documents being disseminated
by EPA's Office of Air Quality Planning and Standards, this does not preclude State and local air
agencies from using these methods to estimate their area and mobile source emissions. However,
State and local air agencies that wish to use the methods described in this document for purposes of
meeting their non-attainment area inventory requirements should first consult with the Chief, Inventory
Guidance and Evaluation Section, Emission Inventory Branch, MD-14, Office of Air Quality Planning
and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
ABSTRACT
The purpose of this report is to provide States and other participants (e.g., Regional Offices,
Headquarters, other Federal agencies) and users of the Area and Mobile Source Subsystem (AMS)
with an understanding of the estimation procedures that will be used by the national component of AMS
to generate emissions estimates for area and mobile source categories. General methodology and
assumptions are discussed as well as the original source of algorithms, activity levels, and emission
factors necessary to calculate emissions for each area and mobile source in AMS. This report presents
methodologies for all identified sources not defined as point sources. Area and mobile sources are
divided into seven major groups, namely, stationary source fuel combustion, mobile sources, industrial
processes, solvent utilization, solid waste disposal, natural sources, and miscellaneous area sources.
Historically, these methodologies have been referred to as the "National Emissions Data System
(NEDS)" methods and to some extent were previously documented in Area Source Documentation for
the 1985 National Acid Precipitation Assessment Program Inventory (EPA-600/8-88-106); however, this
report did not include certain initial data calculations. In addition, over the years numerous changes
have occurred to the sources of the data that "feed" these methodologies. These initial data
calculations and source data changes are included in this document.
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TABLE OF CONTENTS
Page
FOREWORD ii
ABSTRACT ii
LIST OF TABLES v
ACRONYMS vi
ACKNOWLEDGEMENT vrji
METRIC CONVERSION FACTORS vii
1. INTRODUCTION 1-1
2. BACKGROUND 2-1
3. STATIONARY SOURCE FUEL COMBUSTION 3-1
RESIDENTIAL FUEL 3-1
Anthracite Coal 3-2
Bituminous Coal 3-3
Distillate Oil 3-5
Natural Gas 3-6
LPG 3-9
Wood 3-10
COMMERCIAL AND INSTITUTIONAL FUEL 3-12
Anthracite Coal 3-12
Bituminous Coal 3-14
Distillate Oil 3-15
Residual Oil 3-16
Natural Gas 3-18
LPG 3-19
Wood 3-20
INDUSTRIAL FUEL 3-20
Anthracite Coal 3-20
Bituminous Coal 3-24
Distillate Oil 3-28
Residual Oil 3-32
Natural Gas 3-37
LPG 3-44
Wood 3-48
Industrial Coke 3-48
Process Gas 3-48
SULFUR CONTENT 3-48
Anthracite Coal 3-48
Bituminous Coal 3-48
Distillate Oil 3-54
Residual Oil 3-54
iii
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ASH CONTENT 3'54
Anthracite Coal 3'54
Bituminous Coal 3"54
4. MOBILE SOURCES 4-1
HIGHWAY VEHICLES 4-1
Development of Fractional Distribution of VMT by Road Class and Vehicle Type
(Speed Class File) 4-2
County VMT by Vehicle Type 4-5
Gasoline-Powered Vehicles: Fuel Consumption Methodology 4-10
Diesel-Powered Vehicles: Fuel Consumption Methodology 4-11
Motorcycle Registration Estimates by Vehicle Age 4-12
OFF-HIGHWAY SOURCES 4-13
Farm Equipment 4-13
Construction Equipment 4-15
Industrial Equipment 4-16
Lawn and Garden Equipment 4-18
Recreational Vehicles 4-20
AIRCRAFT 4-23
Commercial Aircraft 4-24
Military Aircraft 4-24
Civilian Aircraft 4-25
Unpaved Airstrips 4-26
MARINE VESSELS 4-26
Diesel (Distillate) Oil Vessels 4-26
Residual Oil Vessels 4-27
Gasoline Vessels 4-28
RAILROAD LOCOMOTIVES 4-29
GASOLINE MARKETING 4-30
Retail Gasoline Sales: Gasoline Marketing - Stage I, Stage II, and Spillage 4-31
UNPAVED ROADS 4-32
Unpaved Roads: VMT 4-32
5. INDUSTRIAL PROCESSES 5-1
CONSTRUCTION 5-1
6. SOLVENT UTILIZATION 6-1
SURFACE COATING 6-6
DECREASING (SIC 34 through 39) 6-10
DRY CLEANING (SIC 7215, 7216 and 7218) : 6-12
GRAPHIC ARTS (SIC 264, 265. and 27) 6-14
RUBBER/PLASTICS (SIC 30) 6-16
MISCELLANEOUS INDUSTRIAL (SIC 20-39) 6-18
MISCELLANEOUS NONINDUSTRIAL 6-20
SOLVENT UTILIZATION EMISSION FACTORS 6-21
7. SOLID WASTE DISPOSAL 7-1
ON-SITE INCINERATION 7-1
Solid Waste: Residential On-Site Incineration 7-2
Solid Waste: Industrial On-Site Incineration 7-3
Solid Waste: Commercial/Institutional On-Site Incineration 7-4
IV
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OPEN BURNING 7-5
Solid Waste: Residential Open Burning 7-5
Solid Waste: Industrial Open Burning 7-6
Solid Waste: Commercial/Institutional Open Burning 7-7
8. NATURAL SOURCES 8-1
MISCELLANEOUS WIND EROSION 8-1
9. MISCELLANEOUS AREA SOURCES 9-1
AGRICULTURE PRODUCTION - CROPS 9-1
Acres Under Cultivation (Land Tilling) 9-1
Agricultural Burning : 9-2
OTHER COMBUSTION 9-3
Forest Wildfires 9-4
Managed Burning (Slash/Prescribed Burning) 9-5
Structural Fires 9-6
10. REFERENCES 10-1
LIST OF TABLES
Table No. Title
1. User Categories 6-2
2. Organic Solvents 6-2
3. Percentage End Use of Solvents by Major Solvent Category 6-3
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ACRONYMS
A
AIRS
AMS
AP-42
CO
DOE
DOT
EPA
FAA
FAR
FHWA
FS
HDDV
HDGV
I/M
1C
LDDT
LDDV
LDGT1
LDGT2
LDGV
LPG
LTOs
MC
NEDS
NOAA
NO,
OAQPS
PAD
Pb
PM10
SIC
SCC
S
SO2
so,
TIUS
TSP
VMP
VMT
VOC
ash
Aerometric Information Retrieval System
Area and Mobile Source Subsystem
Compilation of Air Pollutant Emission Factors Vols I & II
carbon monoxide
United States Department of Energy
United States Department of Transportation
United States Environmental Protection Agency
Federal Aviation Administration
Federal Aid Primary System
Federal Highway Administration
Facility Subsystem
Heavy Duty Diesel Vehicles
Heavy Duty Gasoline Vehicles
Inspection/maintenance
internal combustion
Light Duty Diesel Trucks
Light Duty Diesel Vehicles
Light Duty Gasoline Trucks 1
Light Duty Gasoline Trucks 2
Light Duty Gasoline Vehicles
liquefied petroleum gas
landing and takeoff cycles
motorcycles
National Emissions Data System
National Oceanic and Atmospheric Administration
nitrogen oxides
Office of Air Quality Planning and Standards
Petroleum Administration for Defense District
lead
paniculate matter < 10 micrometers
Standard Industrial Classification code
Source Classification Code
sulfur
sulfur dioxide
sulfur oxides
Truck Inventory and Use Survey
total suspended particulates
Varnish Makers and Painters
vehicle miles travelled
volatile organic compounds
VI
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ACKNOWLEDGEM ENT
This report was prepared by the U.S. Environmental Protection Agency's (EPA's) Air and Energy
Engineering Research Laboratory through a cooperative effort with EPA's Office of Air Quality Planning
and Standards. This document was prepared with the assistance of E.H. Pechan & Associates under
EPA Contract No. 68-D9-0168, Work Assignment No. 2/036.
METRIC CONVERSION FACTORS
Non Metric
Acre
Barrels (petroleum, US)
Btu
Cubic Feet
Fahrenheit (°F)
Gallons (US, liquid)
Miles
Miles / Gallon
Miles / Hour
Pounds
Pounds /106 Cubic Feet
Pounds/1000 Gallons
Pounds / Ton
Square Miles
Therms
Tons (short)
Tons / Acre
Multiplied by
4.0469 x 103
158.98
251.83
0.028317
5 / 9 x (°F - 32)
3.7854
1.6093
0.4251
1.6093
453.59
16.015
0.1200
0.500
2.590
251.83X105
0.9072
224.172
Yields Metric
Square Meters
Liters
Calories, Grams
Cubic Meters
Celsius (°C)
Liters
Kilometers
Kilometers / Liter
Kilometers / Hour
Grams
Kilograms /106 Cubic Meters
Kilograms /1000 Liters
Kilograms / Metric Ton
Square Kilometers
Calories, Grams
Tons
Tons (metric) / Square Mile
VII
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SECTION 1
INTRODUCTION
The U.S. Environmental Protection Agency's (EPA's) Office of Air Quality Planning and
Standards (OAQPS) in Research Triangle Park, North Carolina, is in the process of developing a
nationwide data base of estimated air pollutant emissions from area and mobile sources known as the
Aerometric Information Retrieval System (AIRS) Area and Mobile Source Subsystem (AMS).
The purpose of this document is to provide States and other participants and users of AMS
(e.g., Regional Offices, Headquarters, other Federal agencies) with an understanding of the estimation
procedures that will be used by the national component of AMS to generate emissions estimates for
area and mobile source categories. General methodology and assumptions are discussed, as well as
the original source of algorithms, activity levels, and emission factors necessary to calculate emissions
for each area and mobile source in AMS.
This document presents emission estimation methods for all identified sources not defined as
point sources in a specific geographic region. Area sources include all mobile sources, and stationary
sources too small, difficult, or numerous to classify as point sources. Area and mobile sources are
divided into seven major groups: Stationary Source Fuel Combustion, Mobile Sources, Industrial
Processes, Solvent Utilization, Solid Waste Disposal, Natural Sources, and Miscellaneous Area
Sources.
Activity levels are derived primarily from related information published by other Federal
agencies, supplemented by special data developed by EPA for the purpose of developing AMS
emission inventories. Published data such as fuel use by State, motor vehicle miles of travel by State
and county, and forest fire acres burned by State are used with related data such as employment,
population, and miscellaneous geographic and economic data to derive annual county estimates of the
activity levels for each of the AIRS/AMS area source categories. The activity levels derived are
adjusted to account for point source activity (such as fuel use by point sources) so that the area source
data reflect only the activity levels (and resulting calculated emissions) that are not accounted for by
point sources. The source of this point source data is the AIRS Facility Subsystem (FS). Point source
emissions data are submitted annually by each State to EPA for inclusion into the AIRS/FS.
Area and mobile source emissions are estimated for the seven criteria pollutants. The seven
criteria pollutants are Paniculate Matter < 10 micrometers (PM10), Total Suspended Paniculate (TSP),
Sulfur Dioxide (SO2), Nitrogen Oxides (NO,), reactive Volatile Organic Compounds (VOCs), Carbon
Monoxide (CO), and Lead (Pb). Emissions are calculated for each area and mobile source category
utilizing the appropriate emission factors, which are contained in the AMS emission factor file. For
many categories, the same emission factors are used for all counties; for some source categories,
however, State- or county-specific emission factors account for local variables that affect emissions.
The more specific emission factors are used in AMS calculations for all highway motor vehicle
categories, fugitive dust categories, and for selected other categories in a few counties where data are
available to develop more applicable emission factors than the national emission factors.
Emissions estimates, updated annually by AMS, are conducted by first estimating activity levels
for each county and then applying the appropriate emission factor and any applicable control efficiency.
County emissions estimates are then summed to produce national emissions estimates.
1-1
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SECTION 2
BACKGROUND
Historically, the National Emissions Data System (NEDS) has been the computer system the
U.S. Environmental Protection Agency (EPA) has used to calculate, store, and retrieve area and mobile
source emissions for the following criteria pollutants: TSP, sulfur dioxide (SO2), NO,, VOC, and CO.
EPA is in the process of designing and developing a new data subsystem in the Aerometric Information
and Retrieval System (AIRS) called the Area and Mobile Source Subsystem (AMS) which will replace
NEDS.1
AMS will use state-of-the-art data base management software with user-friendly menus and
screens. The goals of AMS are: 1) provide storage and reporting capabilities for area and mobile
source emissions and related data required by EPA regulations and the Clean Air Act; 2) replace the
existing system used to store and report these data with a state-of-the-art system; 3) promote
information sharing among EPA offices and State and local air agencies; 4) provide the ability to
interact with other EPA data bases; and 5) provide enhanced data processing services to the EPA and
State and local user community.1
With the passage of the Clean Air Act Amendments (CAAA) of 1990 in November 1990, a data
system that tracks area and mobile source emissions inventory data becomes critical to the needs of
the Agency. In particular, an area and mobile source data system will be needed to support
implementation of Title I of the CAAA. This takes the form of 1) storing area and mobile source
emissions data as reported by State and local air agencies; and 2) developing comprehensive
capabilities to support CAAA regulatory reporting, tracking, and analytical requirements.1
Emissions inventory data reported to AMS by State and local air agencies for purposes of
supporting Title I of the CAAA involve the reporting of emissions inventory data for nonattainment areas
only. AMS, in addition to supporting Title I requirements, will include a "national component" that will
include emissions inventory data that may be used for regional modeling purposes. Since regional
models require data for both nonattainment and attainment areas and generally require consistent
emission estimation methodologies throughout the modeling domain, this "national component" will
generate emission estimates using a consistent methodology for area and mobile source categories for
all areas of the U.S. - nonattainment and attainment areas.1
In order to accommodate the need to support Title I activities and regional modeling needs, a
basic decision has been made to develop AMS using what may be described as a "parallel approach"
in that EPA would prepare area and mobile source data for all counties in the U.S. Any State data
submitted would reside in "parallel" with the EPA prepared data. As a result of this "parallel approach,"
AMS will consist of two components - a national component and a State component.1
Ideally, a more integrated or "hybrid" approach would be best. (In the "hybrid approach," EPA
would prepare area and mobile source data for all counties in the U.S. Any State data submitted would
replace EPA prepared data for source categories in those counties.) However, implementation of the
hybrid approach will not be attempted in the base system until: 1) better methodologies are available
from emissions inventory research projects currently underway and the States become familiar with an
AMS system, and 2) a "plug-in methodology" capability is fully introduced. The emission estimation
2-1
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procedures that are described in the following sections are the methodologies that will be used within
the "national component" of AMS.1
Historically, these methodologies have been referred to as the "NEDS" methods and are
documented in the following report: Area Source Documentation for the 1985 National Acid
Precipitation Assessment Program Inventory.2 Much of the narrative from that report has been used in
the preparation of this document, since the basic concepts for the estimation of the emissions has
remained comparable to the methods described in the previous report. Currently, a number of
emissions inventory research projects are underway and should provide improved emission estimation
procedures. When these new procedures are available, they will be implemented in AMS.
2-2
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SECTION 3
STATIONARY SOURCE FUEL COMBUSTION
Stationary fuel combustion sources which contribute to area source emissions have been
divided into three major categories: Residential Fuel, Commercial and Institutional Fuel, and Industrial
Fuel. Collectively, these categories account for all stationary fuel combustion activity not usually
reported as point sources. Each category is further subdivided into the following fuel types if
appropriate: anthracite coal, bituminous coal, distillate oil, residual oil, natural gas, liquefied petroleum
gas (LPG), wood, industrial coke, and process gas. Methodologies for activity level estimation and
emission factor derivation are discussed for each category and fuel type.
In the following methodologies for the calculation of activity levels, consumption is determined
for each type of fuel using two general steps.
1) County consumption is calculated using an algorithm based on significant variables for
which county-specific data are available (e.g., degree days, number of rooms per
dwelling, number of dwellings).
2) Resulting county consumption estimates are normalized to reflect published State
consumption data by the following equation:
NCC= ECC
PSC
ESC
where: NCC
ECC
PSC
ESC
Normalized county consumption
Estimated county consumption
Published State consumption
Estimated State consumption (summation of estimated county
consumption)
RESIDENTIAL FUEL
The residential fuel category estimates emissions for residential activities which utilize fuel for
water heating, space heating, and cooking. Emissions contributed by residential fuel consumption are
broken down into six fuel categories including anthracite coal, bituminous coal, distillate oil, natural gas,
LPG, and wood. Emissions from the residential residual oil consumption category are considered to be
negligible; therefore, no method exists for this category. For each of the listed fuel types, activity levels
measured by fuel quantity consumed in weight or volume units are multiplied by emission factors to
obtain emissions estimates. Methodologies for activity levels and emission factors are presented
below.
3-1
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Anthracite Coal
The basic methodology for allocating residential consumption of anthracite coal to individual
counties involves the use of an algorithm which relates coal consumption to the number of dwelling
units and heating degree days. Adjustments are made to housing data to account for secular trends in
the number of coal-heated dwelling units, then the results are normalized as necessary in the steps
below.
1) Variables found to be significant by regression analyses were the number of occupied
dwelling units in the county using coal for space heating and the annual heating degree
days for the county. Dwelling unit data from the latest census are updated using a
regional growth factor which reflects the number of dwellings currently using coal for
space heating purposes.3
2) The number of dwelling units is obtained from the Census Bureau's decennial Census
of Housing.4 Estimates of dwelling units by census region using a particular type of fuel
for space heating purposes for years between the decennial census are found in the
Census Bureau's biennial American Housing Survey.5 The number of annual heating
degree days per county is taken from National Oceanic and Atmospheric
Administration's (NOAA's) Climatological Data.6 Published State residential anthracite
coal consumption is determined from the U.S. Department of Energy's (DOE's) State
Energy Data Report.7
Anthracite Coal Equations -
A normalized estimate of County Residential Anthracite Consumption (NCRA) (in short tons) is
produced by the execution of the following equations:
NCRA = ECA - SRA
where: NCRA = Normalized county anthracite coal consumption by residential
sources
EGA = Estimated county residential anthracite coal consumption
SRA = Published State total of residential anthracite coal consumption
in short tons
c = Number of counties in State
ECA is computed using the formula:
7.64
ECA = 0.00387 - UCH
3-2
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where: UCH = Number of occupied dwelling units in county using coal heat in
current year (computed below)
DD = Annual heating degree days in county
UCH is computed using the formula:
RCH
UCH= CCH
n=1
where: CCH = County housing units using coal heat in census year
RCH = Regional housing units using coal heat in current year
s = Number of States in census region
SCH = State housing units using coal heat in census year
Anthracite Coal Emission Factors ~
Emission factors for anthracite use in hand-fired boilers are taken directly from AP-42, Table
1.2-1 .e For the purposes of this calculation, ash content value and sulfur content value are assumed to
be 11 percent and 0.7 percent, respectively.9 Since there is only one anthracite coal producing district
in the U.S. and the sulfur and ash contents are relatively uniform, this assumption appears reasonable.
Bituminous Coal
The basic methodology for allocating residential consumption of bituminous coal to individual
counties involves the use of an algorithm which relates coal consumption to the number of dwelling
units and heating degree days. Adjustments are made to housing data to account for secular trends in
the number of coal-heated dwelling units. The results are then normalized as necessary in the steps
below.
1) Variables found to be significant by regression analyses were the number of occupied
dwelling units in the county using coal for space heating and the annual heating degree
days for the county. Dwelling unit data from the latest census are updated using a
regional growth factor which reflects the number of dwellings currently using coal for
space heating purposes.3
2) The number of dwelling units is obtained the Census Bureau's decennial Census of
Housing.4 Estimates of dwelling units by census region using a particular type of fuel
for space heating purposes for years between the decennial census are found in the
Census Bureau's biennial American Housing Survey.8 The number of annual heating
degree days per county is taken from NOAA's Climatological Data.6 Published State
residential bituminous coal consumption is determined from the DOE State Energy Data
Report.7
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Bituminous Coal Equations -
A normalized estimate of County Residential Bituminous Consumption (NCRB) (in short tons) is
produced by the execution of the following equations:
NCRB = £CB • SRB
where: NCRB = Normalized county bituminous coal consumption by residential
sources
ECB = Estimated county residential bituminous coal consumption
SRB = Published State total of residential bituminous coal consumption
in short tons
c = Number of counties in State
7.64 - 100°
ECB is computed using the formula:
ECB = 0.00387 • UCH
where: UCH = Number of occupied dwelling units in county using coal heat in
current year (computed below)
DD = Annual heating degree days in county
UCH is computed using the formula:
RCH
UCH = CCH -
n=1
where: CCH = County housing units using coal heat in census year
RCH = Regional housing units using coal heat in current year
s -= Number of States in census region
SCH «= State housing units using coal heat in census year
Bituminous Coal Emission Factors -
The emission factors for hand-fired units are obtained from AP-42, Table 1.1-1.8 For SO2, the
average sulfur content is the weighted average of the sulfur content of each production district from
Coal Production.9 District averages are then weighted according to shipment data for each 'district to
destination1 ("Other Consumers") contained in the DOE document Coal Distribution.10 This
methodology is described in detail in the section on Sulfur Content.
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Distillate Oil
Consumption of distillate oil by residential sources is determined by allocating State
consumption to the county level using housing data. Total county residential consumption is calculated
as the sum of distillate oil used for space heating and other purposes for the most recent census year
and then normalized with total State consumption.
Incorporation of EPA factors along with other variables and performance of a regression
analysis yields an algorithm which determines county consumption of fuel for space and water heating
using the annual heating degree days and the median number of rooms of occupied dwelling units for
each county.11 Distillate oil not used for space heating purposes is estimated by assuming that each
housing unit utilizes 250 gallons of oil per year for hot water heating purposes.
The number of annual heating degree days in each county is found in NOAA's Climatotogical
Data.6 The median number of rooms per dwelling unit in each county is obtained from the Census
Bureau's decennial Census of Housing.4 State distillate oil delivery data (adjusted sales) are available
in DOE's Fuel Oil and Kerosene Sales report.12 Though the Fuel Oil and Kerosene Sales publication
does not report consumption, the AMS methodology assumes the adjusted sales (delivery) data equate
to consumption.
Distillate Oil Equations -
A normalized estimate of County Residential Distillate Oil Consumption (NCO) (in 1 000 gallons)
is produced by the execution of the following equations:
NCO = • STRD
£
CRDOn
where: NCO = Normalized county distillate oil consumption by residential
sources
CRDO = Estimated county residential distillate oil consumption
STRD = Published State total of residential distillate oil consumption in
1000 gallons (computed below)
c = Number of counties in State
CRDO is computed using the formula:
0.01288
.DD+30.14.M/? -79.54^ . ^ + 250 . uow
°-14 _ I _
where: DD «= Annual heating degree days in county
MR = Median number of rooms per dwelling units in the county
UOH = Number of occupied dwelling units in county using oil heat in
current year (computed below)
UOW = Number of occupied dwelling units in county using oil for water
heating in census year
3-5
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STRD is computed using the formula:
STRD = State Residential Distillate # 1 +
State Residential Distillate #2 +
State Residential Kerosene
UOH is computed using the formula:
ROM
UOH = COM -
where: COM = County housing units using oil heat in census year
ROM = Regional housing units using oil heat in current year
s = Number of States in census region
SOH = State housing units using oil heat in census year
Distillate Oil Emission Factors -
Emission factors are taken directly from AP-42, Table 1.3-1.8 For the SO2 factor, average sulfur
content values for No. 1 and No. 2 fuel oils reported in Heating Oils13 are weighted by corresponding
deliveries to residential users found in the DOE report Fuel Oil and Kerosene Sales.12
Natural Gas
In the AMS inventory, residential natural gas consumption is defined as the sum of natural gas
consumption for the purposes of cooking, water heating, and space heating. In general, the
methodology is designed to produce county consumption estimates for each use by fuel type and to
normalize the county estimates with published data. More detailed descriptions of the methodologies
used for the estimation of natural gas consumption are discussed below.
The methodology for determining residential natural gas consumption consists of performing a
series of calculations to update census data so that they can be input into an algorithm which computes
consumption. The final result is then normalized by comparing it to published State data.
Regression analysis was utilized to develop an algorithm which calculated natural gas
consumption based on annual heating degree days, the number of occupied dwelling units using gas
for cooking or water heating fuel, and the median number of rooms per dwelling.3
The number of occupied dwelling units in the county using gas for space heating in the current
year is determined using the number of dwellings with gas heat in the census year, updated to include
the increase in the number of gas heating dwellings since the census year. The increase in the
number of gas heated dwellings per county is estimated by summing (1) the number of additional gas
heated dwellings in the State due to new housing starts - distributed to the county level by population -
- and (2) the number of conversions to gas space heating in the State since the census year,
distributed to the county level by the proportion of dwelling units using gas heat in the census year.
An estimate of the number of occupied dwelling units in the county using gas for all purposes in
3-6
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the current year is computed by dividing the updated number of gas heated dwellings by the
percentage of residential gas customers known to have gas heat from gas utility statistics.
The number of dwellings using gas for all purposes is input with heating degree days and the
median number of rooms per dwelling into an algorithm which yields county estimates of natural gas
consumption. County estimates are then totalled and compared with published State residential
consumption figures.
Annual heating degree days are taken from NOAA's Climatological Data.6 The number of
dwellings using natural gas for space heating and water heating per county is available in the Census
of Housing.4 The median number of rooms per dwelling is obtained from the Census Bureau's
decennial Census of Housing.4 The percentage of residential customers using gas for space heating,
and residential gas heat conversions and heating unit additions data are found in the Gas House
Heating Survey.14 The current county population is found in the Census Bureau's Current Population
Reports.15 The average regional natural gas consumption is obtained from Gas Facts16, and residential
natural gas consumption data are taken from the Natural Gas Annual.17
Natural Gas Equations -
A normalized estimate of County Residential Natural Gas Consumption (NCG) (millions of cubic
feet) is produced by the execution of the following equations:
NCG —BCG • SNG
E
ECGa
where: NCG = Normalized county natural gas consumption by residential
sources
ECG = Estimated county residential natural gas consumption
(computed below)
SNG = Published State total of residential natural gas consumption
(million cubic feet)
c = Number of counties in State
ECG is computed using the formula:
ECG = 47.5 • UG • DD03*7 -
UGH
10.588
ux
MR0
.125
where: UG = Number of occupied dwelling units in county using piped gas in
current year
DD = Annual heating degree days in county
UGH = Number of occupied dwelling units in county using gas heat in
census year
UX = Number of occupied dwelling units in county using gas for
cooking or hot water fuel in census year, whichever is larger
MR = Median number of rooms per dwelling units in the county
3-7
-------
UG is computed using the formula:
CGH
UG =
RPH
where: CGH = Number of occupied dwelling units in county using gas heat in
current year (computed below)
RPH = Percentage of residential gas customers in State with gas heat
CGH is computed using the equation:
CGH = UGH + IGH
where: UGH = Number of occupied dwelling units in county using gas heat in
census year
IGH = Total increase since census year in county dwelling units using
gas for space heating (computed below)
IGH is computed using the equation:
IGH =
CPC
\
c
E
n=1
J<*2.
where: CPC = Growth in county population since census year (computed
below)
A = Number of additional gas-heated dwelling units in State due to
new housing starts since census year
UGH = Number of occupied dwelling units in county using gas heat in
census year
SGH = Number of occupied dwelling units in State using gas heat in
census year
C = Number of conversions to gas space heating in the State since
census year
c = Number of counties in State
CPC is computed using the equation:
CPC = CP - CCP
NOTE: If CP - CCP < 0, then CPC = 0.
where: CP = Current county population
CCP = County population in most recent census year
3-8
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Natural Gas Emission Factors -
Emission factors for natural gas consumption are obtained from AP-42, Table 1.4-1.8
LPG
In the AMS inventory, residential LPG consumption is defined as the LPG consumption for the
purposes of cooking, water heating, and space heating. In general, the methodology is designed to
produce county consumption estimates for each use by fuel type, and normalize the county estimates
with published LPG consumption data. More detailed descriptions of the methodologies used for the
estimation of LPG consumption are discussed below.
County residential consumption of LPG is approximated by an algorithm using county annual
heating degree days, the number of occupied dwelling units in the county using LPG for space heating,
water heating and cooking fuel in the county, and the average regional consumption by water heaters
and cooking ranges.3
Annual heating degree days are taken from NOAA's Climatological Data.6 The number of
occupied dwelling units in the county using LPG for space heating and water heating is available from
the Census of Housing.4 Average regional consumption data are obtained from Gas Facts.16
Residential LPG consumption information is found in the State Energy Data Report.7
LPG Equations -
A normalized estimate of County Residential LPG Consumption (NCL) (in 1000 gallons) is
produced by the execution of the following equations:
NCL - ECL • SfJL • 42
where: NCL = Normalized county LPG consumption by residential sources
ECL = Estimated county residential LPG consumption (computed
below)
SRL = Published State total of residential LPG consumption in 1000
barrels
42 = Factor to convert barrels to gallons
c = Number of counties in State
ECL is computed using the formula:
ECL = 0.00105 - CLT
where: CLT = Estimated county residential LPG consumption in therms
(computed below)
NOTE: 0.00105 is the factor used to convert therms to thousands of gallons of LPG
3-9
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CLT is computed using the formula:
CLT = (376 + 0.209DD) • ULH + (RAW • ULW) + (RAC • ULQ
where: DD = Annual heating degree days in county
ULH = Number of occupied dwelling units in county using LPG for
space heating in current year (computed below)
RAW = Average regional consumption (therms/year) of gas by water
heaters
ULW = Number of occupied dwelling units in county using LPG for
water heating in census year
RAC = Average regional consumption (therms/year) of gas by cooking
ranges
ULC = Number of occupied dwelling units in county using LPG as
cooking fuel in census year
ULH is computed using the equation:
RLH
ULH = CLH
5
E
/7=1
where: CLH = Number of occupied dwelling units in county using LPG for
space heating in census year
RLH = Number of occupied dwelling units in census region using LPG
for space heating in current year
s = Number of States in census region
SLH = Number of occupied dwelling units in State using LPG for
space heating in census year
Census publications report housing units using bottled gas for space heating. For purposes of
AMS calculations, bottled gas is assumed to equate to LPG.
LPG Emission Factors -
Emission factors for LPG combustion are obtained from AP-42, Table 1.5-1."
Wood
In the AMS inventory, residential wood consumption is defined as the wood consumption for the
purposes of space heating. In general, the methodology is designed to produce county consumption
estimates and normalize the county estimates with published wood consumption data. More detailed
descriptions of the methodologies used for the estimation of wood consumption are discussed below.
County residential consumption of wood is allocated to counties by an algorithm using county
annual heating degree days and the number of occupied dwelling units in the county using wood for
space heating.
3-10
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Annual heating degree days are taken from NOAA's Climatological Data.6 The number of
occupied dwelling units in the county using wood for space heating is available from the Census of
Housing.4 Residential wood consumption information is found in the Estimates of U.S. Wood Energy
Consumption18 and the Household Energy Consumption and Expenditures.19
The original State estimates presented in DOE's Estimates of U.S. Wood Energy
Consumption18 are updated annually using regional wood consumption estimates reported in the
Household Energy Consumption and Expenditures19 and regional estimates of dwelling units using
wood for space heating purposes as reported in the American Housing Survey.5
Wood Equations -
An estimate of County Residential Wood Consumption (CRW) (in short tons) is calculated using
the following equations:
If State data exist, then use the following equation:
( UWH DD \
CRW =
(SWH SDD
UWH
SRW
SWHn SDDnj
If regional data exist, then use the following equation:
DD\
(SWH + SDD)
DD
n
SDD
n
SRW
RRW
£ SRW.
pn
where: CRW
UWH
SWH
DD
SDD
SRW
SRWP
RRW
c
s
Normalized county residential wood consumption
Number of occupied housing units in county using wood for
space heating in current year (computed below)
Number of occupied housing units in county using wood for
space heating
Annual heating degree days in county
Annual heating degree days in State
Reported State residential wood consumption in current year
Reported State residential wood consumption in previous year
Reported regional residential wood consumption in current year
Number of counties in the State
Number of States in the region
3-11
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UWH is computed using the equation:
RWH
UWH = CWH
/7=1
where: CWH = Number of occupied dwelling units in county using wood for
space heating in census year
RWH = Number of occupied dwelling units in census region using wood
for space heating in current year
s = Number of States in region
SWH = Number of occupied dwelling units in State using wood for
space heating in census year
Wood Emission Factors ~
Emission factors for woodstoves and fireplaces from AP-42, Tables 1.9-1 and 1.10-18 are
weighted based on the proportions of wood burned in woodstoves and in fireplaces.
Weighting is accomplished by performing a series of calculations on computed wood
consumption estimates which includes: (1) estimating the number of stoves based on shipments and
imports from Estimates of U.S. Wood Energy Consumption.16 (2) calculating an obsolescence rate to
determine the total stove inventory in current use, and (3) determining the stove population in primary
and secondary use based on the number of dwellings units using wood heat as found in the American
Housing Survey.5 Stove efficiency is also taken into account.
COMMERCIAL AND INSTITUTIONAL FUEL
Area source emissions from fuel use by commercial and institutional sources consist of
emissions from all fuel burned in stationary sources that are not included under residential sources,
industrial sources, power plants, or commercial point sources. Examples of commercial/institutional
area sources are hospitals, hotels, laundries, schools, and universities. Fuel types included in the
discussion of activity levels and emission factors are anthracite coal, bituminous coal, distillate oil,
residual oil, natural gas, LPG, and wood.
Activity levels are estimated for anthracite coal, bituminous coal, distillate oil, residual oil,
natural gas, LPG and wood. Currently, AMS does not employ a methodology to estimate wood fuel
consumption by commercial/institutional sources. Emissions from this source are considered negligible
compared to those from other sources.
Anthracite Coal
The county commercial/institutional area source activity level of anthracite coal is calculated by
first determining State total commercial/institutional area source anthracite coal consumption and
allocating this area source coal consumption to counties via county and State commercial employment
figures.
3-12
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Commercial/institutional anthracite coal consumption is found in DOE's State Energy Data
Report.7 Consumption of anthracite coal by commercial/institutional point sources is obtained from
AIRS/FS Point Source Data Files. Employment data are obtained from either the Census Bureau's
Census of Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
Anthracite Coal Equations -
An estimate of County Commercial Anthracite Coal (CAC) (in short tons) is calculated as
follows:
CCE
CAC = SACAC
SCE
where: CAC = Estimated county anthracite coal consumption by commercial
sources
SACAC = State commercial area source anthracite coal consumption
(computed below)
CCE = County employment for SICs 50 through 97
SCE = State employment for SICs 50 through 97
SACAC is computed as follows:
SACAC = STCAC - PTCAC
NOTE: If SACAC < 0. then set SACAC = 0.
where: STCAC = Published State total commercial anthracite coal consumption
PTCAC = State commercial point source anthracite coal consumption
(computed below)
PTCAC is computed as follows:
PTCAC = £ APCSn
where: s = AIRS Facility points for SCC 1-03-001-"
APCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
NOTE: The double asterisk "**" indicates a series of SCCs belonging to a general
group. For example, the general group represented by 1-03-001-** indicates that
several different boiler types may be found within this series.
3-13
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Anthracite Coal Emission Factors -
Emission factors are obtained from AP-42, Table 1.2-18 for the boiler types listed for SCC
1-03-001-" in the AIRS/FS Point Source Data Files.20 The emission factors are then combined by
weighting each factor in proportion to the total AIRS/FS anthracite coal consumption of each boiler type.
For the purpose of this calculation, it is assumed that ash content is 11 percent and that sulfur content
is 0.7 percent.9
Bituminous Coal
The county commercial/institutional area source activity level of bituminous coal is calculated by
first determining State total commercial/institutional area source bituminous coal consumption and then
allocating this area source coal consumption to counties via county and State commercial employment
figures.
Commercial/institutional bituminous coal consumption is found in DOE'S State Energy Data
Report7. Consumption of bituminous coal by commercial/institutional point sources is obtained from
AIRS/FS Point Source Data Files.20 Employment data are obtained from either the Census Bureau's
Census of Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
Bituminous Coal Equations -
An estimate of County Commercial Bituminous Coal Consumption (CBC) (in short tons) is
calculated as follows:
CBC = SACBC - -^
SCE
where: CBC = Estimated county bituminous coal consumption by commercial
sources
SACBC = State commercial area source bituminous coal consumption
(computed below)
CCE = County employment for SICs 50 through 97
SCE = State employment for SICs 50 through 97
SACBC is computed as follows:
SACBC = STCBC - PTCBC
NOTE: If SACBC < 0, then set SACBC = 0.
where: STCBC = Published State total commercial bituminous coal consumption
PTCBC = State commercial point source bituminous coal consumption
(computed below)
3-14
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PTCBC is computed as follows:
PTCBC = £ BPCSn
where: s = AIRS Facility points for source classification codes
1 -03-002-"
1 -03-003-"
BPCS = Annual throughput at commercial point source classification
codes in the AIRS/FS Point Source Data Files20 summed by
State
Bituminous Coal Emission Factors -
Weighted emission factors for boilers are obtained using emission factors from AP-42, Table
1.1-18 and coal consumption from AIRS/FS Point Source Data Files20 for SCC 1 -03-002-** and
1 -03-003-". Average sulfur content value is determined by weighted average of the sulfur content of
each production district found in Coal Production.9 District averages are then weighted according to
shipment data for each 'district to destination' ("Other Consumers") contained in DOE's Coal
Distribution.10
Distillate Oil
The county commercial/institutional area source activity level of distillate oil is calculated by first
determining State total commercial/institutional area source distillate oil consumption and allocating this
area source oil consumption to counties via county and State commercial employment figures.
Commercial/institutional distillate oil deliveries (adjusted sales) are found in DOE's Fuel Oil and
Kerosene Sales report.12 The Fuel Oil and Kerosene Sales publication does not report consumption.
However, the AMS methodology assumes that the delivery (adjusted sales) data equate to
consumption. Consumption of distillate oil by commercial/institutional point sources is obtained from
AIRS/FS Point Source Data Files20. Employment data are obtained from either the Census Bureau's
Census of Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
Distillate Oil Equations -
An estimate of County Commercial Distillate Oil Consumption (CDO) (in 1 000 gallons) is
calculated as follows:
CDO = SACDO
SCE
where: CDO = Estimated county distillate oil consumption by commercial
sources
SACDO = State commercial area source distillate oil consumption
(computed below)
CCE = County employment for SICs 50 through 97
3-15
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SCE = State employment for SICs 50 through 97
SACDO is computed as follows:
SACDO = STCDO - PTCDO
NOTE: If SACDO < 0, then set SACDO - 0.
where: STCDO
PTCDO
Published State total commercial distillate oil consumption
State commercial point source distillate oil consumption
STCDO is computed as follows:
STCDO
State Commercial Distillate # 1
State Commercial Distillate # 2
State Commercial Distillate # 4
State Commercial Kerosene
State Farm Use: Other Distillate
State Farm Use: Kerosene
State Military: Other Distillate
PTCDO is computed as follows:
sec
PTCDO =
DPCS
n
where:
SCC
DPCS
AIRS Facility points for SCCs 1-03-005-** and
2-03-001-**
Annual throughput at commercial point sources in the
AIRS/FS Point Source Data Files20 summed by State
Distillate Oil Emission Factors -
Emission factors are taken directly from AP-42, Table 1.3-1." For SO2, average sulfur content
values for No, 1, No. 2, and No. 4 oils from Heating Oils13 are weighted using commercial deliveries
(adjusted sales) by oil type as reported in the Fuel Oil and Kerosene Sales12 report.
Residual Oil
The county commercial/institutional area source activity level of residual oil is calculated by first
determining State total commercial/institutional area source residual oil consumption and then allocating
this area source oil consumption to counties via county and State commercial employment figures.
Commercial/institutional residual oil deliveries (adjusted sales) are found in DOE's Fuel Oil and
Kerosene Sales18 report. The Fuel Oil and Kerosene Sales publication does not report consumption.
However, the AMS methodology assumes that the delivery (adjusted sales) data equate to
consumption. Consumption of residual oil by commercial/institutional point sources is obtained from
3-16
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AIRS/FS Point Source Data Files20. Employment data are obtained from either the Census Bureau's
Census of Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
Residual Oil Equations -
An estimate of County Commercial Residual Oil Consumption (CRO) (in 1000 gallons) is
calculated as follows:
CRO = SACRO •
SCE
where: CRO = Estimated county residual oil consumption by commercial
sources
SACRO = State commercial area source residual oil consumption
(computed below)
CCE = County employment for SICs 50 through 97
SCE = State employment for SICs 50 through 97
SACRO is computed as follows:
SACRO = STCRO - PTCRO
NOTE: If SACRO < 0, then set SACRO = 0.
where: STCRO = Published State total commercial residual oil consumption
PTCRO = State commercial point source residual oil consumption
(computed below)
STCRO is computed as follows:
STCRO = State Commercial Residual Oil +
State Military Residual Oil
PTCRC is computed as follows:
PTCRO = £ RPCSn
where: s = AIRS Facility points for SCC 1-03-004-"
RPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
3-17
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Residual Oil Emission Factors -
Emission factors are taken directly from AP-42, Table 1.3-1.8 Sulfur content values are
obtained for No. 5 light, No. 5 heavy, and No. 6 fuel oils in Heating Oils.13 A weighted average is
calculated using No. 6 sulfur content and for the mean of No. 5 oil sulfur contents, assuming 13 percent
and 87 percent of the fuel oil used is No. 5 and No. 6, respectively.
Natural Gas
The county commercial/institutional area source activity level of natural gas is calculated by first
determining State total commercial/institutional area source natural gas consumption and allocating this
area source oil consumption to counties via county and State commercial employment figures.
Commercial/institutional natural gas consumption is found in DOE's report entitled Natural Gas
Annual.17 Consumption of natural gas by commercial/institutional point sources is obtained from
AIRS/FS Point Source Data Files.20 Employment data are obtained from either the Census Bureau's
Census of Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
Natural Gas Equations -
An estimate of County Commercial Natural Gas Consumption (CNG) (million cubic feet) is
calculated as follows:
CNG = SACNG
SCE
where: CNG = Estimated county natural gas consumption by commercial
sources
SACNG = State commercial area source natural gas consumption
(computed below)
CCE = County employment for SICs 50 through 97
SCE = State employment for SICs 50 through 97
SACNG is computed as follows:
SACNG = STCNG - PTCNG
NOTE: If SACNG < 0, then set SACNG = 0.
where: STCNG = Published State total commercial natural gas consumption
PTCNG = State commercial point source natural gas consumption
(computed below)
3-18
-------
PTCNG is computed as follows:
PTCNG = £ NGPCSn
where: s = AIRS Facility points for SCCs
1-03-006-"
2-03-002-"
NGPCS = Annual throughput at commercial point sources in the AIRS/PS
Point Source Data Files20 summed by State
Natural Gas Emission Factors -
Emission factors for natural gas are obtained directly from AP-42, Table 1.4-1."
LPG
The county commercial/institutional area source activity level of LPG is calculated by first
determining State total commercial/institutional area source LPG consumption and allocating this area
source oil consumption to counties via county and State commercial employment figures.
Commercial/institutional LPG consumption is found in DOE's State Energy Data Report.7
Consumption of LPG by commercial/institutional point sources is obtained from AIRS/FS Point Source
Data Files.20 Employment data are obtained from either the Census Bureau's Census of
Manufacturers21 (quinquennial) or the Census Bureau's County Business Patterns22 (annual).
LPG Equations -
An estimate of County Commercial LPG Consumption (CLG) (1000 gallons) is calculated as
follows:
CCE
CLG = SACLP
SCE
where: CLG = Estimated county LPG consumption by commercial sources
SACLP = State commercial area source LPG consumption (computed
below)
CCE = County employment for SICs 50 through 97
SCE = State employment for SICs 50 through 97
The formula to compute (SACLP) is:
SACLP = [STCLP - 42] - PTCLP
NOTE: If SACLP < 0, then set SACLP = 0.
3-19
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where: STCLP = Published State total commercial LPG consumption
PTCLP = State commercial point source LPG consumption (computed
below)
PTCLP is computed using the equation:
PTCLP = £ LPPCSn
/7=1
where: s = AIRS Facility points for source classification codes
1-03-010-"
2-03-010-"
LPPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
LPG Emission Factors -
Emission factors for LPG are obtained directly from AP-42, Table 1.5-1.8
Wood
No methodology has been developed for commercial/institutional wood use. Emissions from
this source are considered negligible compared to those from other area sources.
INDUSTRIAL FUEL
Area source emissions generated by the industrial fuel consumption sector which are not
accounted for by point source categories are discussed for the following fuel types: anthracite coal,
bituminous coal, distillate oil, residual oil, natural gas, LPG, wood, industrial coke, and process gas.
Methodologies for consumption and emission factor computation are presented as available.
A procedure was developed for the allocation of State industrial area source consumption of
bituminous coal, distillate oil, residual oil, natural gas, and LPG.3-11 The procedure for estimating
industrial bituminous coal area source consumption has been adjusted and applied to estimating
industrial anthracite coal area source consumption. Originally, the procedure for industrial natural gas
consumption called for the inclusion of industrial LPG consumption. LPG will now be estimated on a
separate basis. In addition, industrial natural gas consumption at boilers and industrial natural gas
consumption at internal combustion (1C) engines will be estimated on a separate basis.
Procedures for estimating coke, wood, and process gas activity levels have not been
developed. Industrial area source consumption of these fuels is assumed to be negligible.
Anthracite Coal
The methodology for determining anthracite coal consumption by industrial area sources
consists of two steps. County industrial fuel consumption for anthracite coal is calculated on a county
basis, where county values are summed and then normalized with the State published value.3 Sources
of inputs and normalization are discussed below.
3-20
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The first step in the methodology is to determine industrial anthracite coal consumption by
county. This is accomplished by adjusting county area source employment figures for SIC categories
20 through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel » in this case anthracite coal
-- for each SIC category by the respective State employment. (If State data are not available, regional
data are used. If regional data are not available, national data are used.) County area source
consumption is then summed for all counties to obtain State area source consumption for anthracite
coal.
County consumption values are then normalized to agree with the State level calculated
industrial area source consumption values for anthracite coal. Reported industrial area source
consumption is calculated by subtracting the point source industrial anthracite coal consumption as
reported to AIRS/FS from the published State total anthracite coal consumption.
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial coal
consumption for States for each year is found in DOE's State Energy Data Report7 and industrial coal
shipments for States for each year are found in DOE's Coal Distribution: January-December report.10
Information concerning consumption of bituminous coal by SIC category is found in DOE's
Manufacturing Energy Consumption Survey23 and is used to calculate fuel intensity factors. State
industrial point source data are taken directly from AIRS/FS Point Source Data Files.20
Anthracite Coal Equations -
A normalized estimate of County Industrial Anthracite Coal Consumption (NCIA) (in short tons)
is computed using the formula:
NCIA = GIF. • ^—
** r>
where: NCIA = Normalized county industrial anthracite coal consumption
CIF4 = Estimated county anthracite consumption by industrial sources
(computed below)
SIA = Reported State industrial area source anthracite coal
consumption (computed below)
c = Number of counties in State
SIA is computed using the formula:
SIA = SOI A - SPA
If SIA < 0, then set SIA = 0.
where: SOIA = Total State industrial anthracite coal consumption (computed
below)
3-21
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SPA = State industrial point source anthracite coal consumption
(computed below)
SPA is computed using the formula:
sec
SPA = £ APISn
where: SCC = AIRS Facility points for SCCs 1-02-001-" and 3-90-001-"
APIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
SOIA is computed using the formula:
SSIA
SO/A = TSA
SSIA + SSCA
where: TSA = Published State total industrial anthracite coal consumption
SSIA = Published total of anthracite shipments to "other industrial"
users by State
SSCA = Published total of anthracite shipments to coke plants by State
An estimate of County Industrial Anthracite Fuel consumption (CIF4) is derived with the
following formula:
SIC
C/F4 = £ CAEj - FIR4J
where: CIF4 = Estimated county industrial anthracite fuel consumption
SIC = SIC codes 20 through 39
CAEj = County area source employment for SICj
FIR4) = State fuel intensity ratio - a measure of fuel use intensity per
employee for anthracite coal by SIC category j
is computed using the formula:
CAEj = TCEj - CPEj
where: TCE, = Total employment in county for SIC category j
CPEj = Point source employment in county for SIC category j
3-22
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State fuel intensity ratio (FIR4j) is computed using the formula:
where: F4j = State consumption of anthracite coal by SIC category j
Ej = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
NOTE: If input data are not available to compute State fuel intensity ratios, then RFR4j
is substituted for FIR^ in the formula used to compute estimates of county
industrial anthracite fuel consumption CIF4. In this case the formula used is:
SIC
CIFAJ = £ OAEj - RFR4J
where: RFR^ = Regional fuel intensity ratio for anthracite coal by SIC category j
(computed below)
is computed using the formula:
where: RF^ = Regional consumption of anthracite coal by SIC category j
REj = Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFR4j is substituted for RFR4j in the formula used to compute estimates of
county industrial anthracite fuel consumption CIF4. In this case the formula
used is:
SIC
CAEJ ' NFRAt
where: NFR4j = National fuel intensity ratio for anthracite coal by SIC category
(computed below)
3-23
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NFR4j is computed using the formula:
where: NF^ = National consumption of anthracite coal by SIC category j
NE, = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
Anthracite Coal Emission Factors -
Emission factors are obtained from AP-42, Table 1.2-18 for the boiler types listed for SCCs
1-02-001-" and 3-90-001-" in the AIRS/FS Point Source Data Files20 files. The emission factors are
then combined by weighting each factor in proportion to the total AIRS/FS anthracite coal consumption
of each boiler type. For the purpose of this calculation, it is assumed that ash content is 11 percent,
and that sulfur content is 0.7 percent.9
Bituminous Coal
The methodology for determining bituminous coal consumption by industrial area sources
consists of two steps. County industrial fuel consumption for bituminous coal is calculated on a county
basis, county values are summed, and then normalized with the State published value.3 Sources of
inputs and normalization are discussed below.
The first step in the methodology is to determine industrial bituminous coal consumption by
county. This is accomplished by adjusting county area source employment figures for SIC categories
20 through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel ~ in this case bituminous coal
- for each SIC category by the respective State employment. (If State data are not available, regional
data are used. If regional data are not available, national data are used.) County area source
consumption is then summed for all counties to obtain State area source consumption for bituminous
coal.
County consumption values are then normalized to agree with the State level calculated
industrial area source consumption values for bituminous coal. Reported industrial area source
consumption is calculated by subtracting the point source industrial bituminous coal consumption as
reported to AIRS/FS from the published State total bituminous coal consumption.
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial coal
consumption for States for each year is found in DOE's State Energy Data Report7 and industrial coal
shipments for States for each year are found in DOE's Coal Distribution: January-December report.10
Information concerning consumption of bituminous coal by SIC category is found in DOE's
Manufacturing Energy Consumption Survey23 and is used to calculate fuel intensity factors. State
industrial point source data are taken directly from AIRS/FS Point Source Data Files.20
3-24
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Bituminous Coal Equations -
A normalized estimate of County Industrial Bituminous Coal Consumption (NCB) (in short tons)
is computed using the formula:
NCB = CIF4 • ——
" **
n--
where: NCB = Normalized county industrial bituminous coal consumption
CIF4 = Estimated county bituminous consumption by industrial sources
(computed below)
SIB = Reported State industrial area source bituminous coal
consumption (computed below)
c = Number of counties in State
SIB is computed using the formula:
SIB = SOIB - SPB
If SIB < 0, then set SIB = 0.
where: SOIB = Total State industrial bituminous coal consumption (computed
below)
SPB = State industrial point source bituminous coal consumption
(computed below)
SOIB is computed using the formula:
SSIB
SOIB = TSB •
SSIB + SSCB
where: TSB = Published State total industrial bituminous coal consumption
SSIB = Published total of bituminous shipments to "other industrial"
users by State
SSCB = Published total of bituminous shipments to coke plants by State
SPB is computed using the formula:
sec
SPB = £ IPBSn
3-25
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where: SCC = AIRS Facility points for SCCs
1-02-002-"
1-02-003-"
3-90-002-"
3-90-003-"
BPCS = Annual throughput at the commercial point sources in the
AIRS/FS Point Source Data Files20 summed by State
An estimate of County Industrial Bituminous Fuel consumption (CIF4) is derived with the
following formula:
SIC
CIF* = £ C*Ej ' Flf*4j
where: CIF4 = Estimated county industrial consumption of bituminous coal
SIC = SIC codes 20 through 39.
CAEj = County area source employment for SICj
FIR^ = Fuel intensity ratio - a measure of fuel use intensity per
employee for bituminous coal by SIC category j
is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
CPE, = Point source employment in county for SIC category j
State fuel intensity factor (FIR^) is computed using the formula:
where: F4j = State consumption of bituminous coal by SIC category j
EJ = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
3-26
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NOTE: If input data are not available to compute State fuel intensity ratios, then RFR4j
is substituted for FIR4j in the formula used to compute estimates of county
industrial bituminous fuel consumption CIF4. In this case the formula used is:
SIC
CIFAJ = £ CAEj • RFRAJ
where: RFR4j = Regional fuel intensity ratio for bituminous coal by SIC category
j (computed below)
RFR4j is computed using the formula:
where: RF^ = Regional consumption of bituminous coal by SIC category j
REj = Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFR4j is substituted for FIR^ in the formula used to compute estimates of
county industrial anthracite fuel consumption CIF4. In this case the formula
used is:
SIC
OIFAJ - £
7=1
where: NFR4j = National fuel intensity ratio for bituminous coal by SIC category
j (computed below)
is computed using the formula:
where: NF4j = National consumption of bituminous coal by SIC category j
NEj = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
3-27
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Bituminous Coal Emission Factors -
Weighted emission factors are taken from AIRS/FS Point Source Data Files20 for SCC
1-02-002-".
In order to obtain weighted emission factors for this category, the amount of coal consumption
must be first obtained from AIRS FS for SCC 1-02-002-". (The double asterisk """ indicates a series
of SCCs belonging to the general group 1-02-002.) The following general equation is then used to
compute weighted emissions factors:
where: EFW = Weighted emission factor for a given pollutant
EFgcc, = AP-42 emission factor for the first SCC in the series
FCscci = Fuel consumption from AIRS/FS for the first SCC in the series
The average sulfur content for shipments from each coal producing State to other industrial
users is taken from Coal Production8 and weighted for each production district. District averages are
weighted by shipments data from each 'district to a destination,' as found in Coal Distribution.10 The
control efficiency for particulates is calculated by projecting the previous year's control efficiency.
Distillate Oil
The methodology for determining distillate oil consumption by industrial area sources consists
of two steps. County industrial fuel consumption for distillate oil is calculated on a county basis, county
values are summed, and then normalized with the State published value.11 Sources of inputs and
normalization are discussed below.
The first step in the methodology is to determine industrial distillate oil consumption by county.
This is accomplished by adjusting county area source employment figures for SIC categories 20
through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel - in this case distillate oil ~
for each SIC category by the respective State employment. (If State data are not available, regional
data are used. If regional data are not available, national data are used.) County area source
consumption is then summed for all counties to obtain State area source consumption for distillate oil.
County consumption values are then normalized to agree with the State-level calculated
industrial-area source consumption values for distillate oil. Reported industrial-area source
consumption is calculated by subtracting the point source industrial distillate oil consumption as
reported to AIRS/FS from the adjusted State total distillate oil consumption. The adjusted State total of
distillate oil consumption is obtained by subtracting the distillate oil consumed at petroleum refinery
process heaters from the published State total distillate oil deliveries (adjusted sales).
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial
3-28
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distillate oil consumption for States for each year is found in DOE's Fuel Oil and Kerosene Sales12
report. The Fuel Oil and Kerosene Sales publication does not report consumption. However, the AMS
methodology assumes that delivery (adjusted sales) data equate to consumption. Information
concerning the amount of distillate oil consumed at petroleum refineries is found in DOE's Petroleum
Supply Annual.24 Information concerning consumption of distillate oil by SIC category is found in DOE's
Manufacturing Energy Consumption Survey23 and is used to calculate fuel intensity factors. State
industrial point source data are taken directly from AIRS/FS Point Source Data Files.20
Distillate Oil Equations -
A normalized estimate of County Industrial Distillate Oil Consumption (NCD) (1000 gallons) is
computed using the formula:
NCD = C/F2 - —
*• f
where: NCD = Normalized county industrial distillate oil consumption
CIF2 = Estimated county distillate oil consumption by industrial sources
(computed below)
SID = Reported State industrial area source distillate oil consumption
c = Number of counties in State
SID is computed using the formula:
SID = TSD - SPD
If SID < 0. then set SID = 0.
where: TSD = Total State industrial distillate oil consumption (computed
below)
SPD = State industrial point source distillate oil consumption
(computed below)
SPD is computed using the formula:
sec
£
n-1
SPD = £ DPISn
where* SCC = AIRS Facility points for SCCs
1-02-005-"
3-90-005-"
2-02-001-"
2-02-004-"
2-02-009-"
3-29
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DPIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
TSD is computed using the formula:
TSD = SOCD + SDI
where: SOCD = State distillate oil consumption at oil companies (computed
below)
SDI = State distillate oil deliveries to industry (computed below)
SDI is computed using the equation:
SDI = State Industrial Distillate # 1 +
State Industrial Distillate #2 +
State Industrial Diesel #2 +
State Industrial Distillate #4 +
State Industrial Kerosene +
State All Other Distillate +
State All Other Kerosene
SOCD is computed using the formula:
SOCD = SDO - SPHD
If SOCD < 0, then set SOCD = 0.
where: SDO = State distillate oil deliveries to oil companies
SPHD = State distillate oil used for process heating at oil companies
(computed below)
SPHD is computed using the formula:
SDO
SPHD = DRO •
where: DRO = Distillate oil consumed at refineries by Petroleum Administration
for Defense (PAD) district
SDO = State distillate oil deliveries to oil companies
s = Number of States in a PAD district
3-30
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An estimate of County Industrial Distillate Fuel consumption (CIF^ is derived with the following
formula:
SIC
y=i
CIF2 = £ CAEj
where: CIF2 = Estimated county industrial consumption of distillate oil
SIC = SIC codes 20 through 39.
County area source employment for SICj
State fuel intensity ratio: a measure of fuel use intensity per
employee for distillate oil by SIC category j
is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
CPEj = Point source employment in county for SIC category j
State fuel intensity ratio (FIR^ is computed using the formula:
where: F2j = State consumption of distillate oil by SIC category j
Ej = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
NOTE: If input data are not available to compute State fuel intensity ratios, then
is substituted for FIR^ in the formula used to compute estimates of county
industrial distillate oil fuel consumption CIF2. In this case the formula used is
SIC
:2J = £ CAE1 ' RFR't
>2J
where: RFR^ = Regional fuel intensity ratio for distillate oil by SIC category j
(computed below)
3-31
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is computed using the formula:
where: RF^ = Regional consumption of distillate oil by SIC category j
REj = Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFR^j is substituted for FIR^ in the formula used to compute estimates of
county industrial distillate oil fuel consumption CIF2. In this case the formula
used is:
SIC
CAEJ ' NFR2J
where: NFR^ = National fuel intensity ratio for distillate oil by SIC category j
(computed below)
is computed using the formula:
where: NF^ = National consumption of distillate oil by SIC category j
NEj = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
Distillate Oil Emission Factors -
Emission factors are found in AP-42, Table 1.3-1.8 For SO2, the average sulfur contents for No.
1, No. 2, and No. 4 fuel oils are taken from Heating Oils.13
Residual Oil
The methodology for determining residual oil consumption by industrial area sources consists of
two steps. County industrial fuel consumption for residual oil is calculated on a county basis, county
values are summed, and then the figures are normalized with the State published value.11 Sources of
inputs and normalization are discussed below.
3-32
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The first step in the methodology is to determine industrial residual oil consumption by county.
This is accomplished by adjusting county area source employment figures for SIC categories 20
through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel -- in this case residual oil - for
each SIC category by the respective State employment. (If State data are not available, regional data
are used. If regional data are not available, national data are used.) County area source consumption
is then summed for all counties to obtain State area source consumption for residual oil.
County consumption values are then normalized to agree with the State level calculated
industrial area source consumption values for residual oil. Reported industrial area source consumption
is calculated by subtracting the point source industrial residual oil consumption as reported to AIRS/FS
from the adjusted State total residual oil consumption. The adjusted State total residual oil
consumption is obtained by subtracting the residual oil consumed at petroleum refinery process heaters
from the published State total residual oil deliveries (adjusted sales).
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial
residual oil consumption for States for each year is found in DOE's Fuel Oil and Kerosene Sales.12 The
Fuel Oil and Kerosene Sales publication does not report consumption. However, the AMS methodology
assumes that delivery (adjusted sales) data equate to consumption. Information concerning the amount
of residual oil consumed at petroleum refineries is found in DOE's Petroleum Supply Annual.24
Information concerning consumption of residual oil by SIC category is found in DOE's Manufacturing
Energy Consumption Survey23 and is used to calculate fuel intensity factors. State industrial point
source data are taken directly from AIRS/FS Point Source Data Files.20
Residual Oil Equations -
A normalized estimate of County Industrial Residual Oil Consumption (NCR) (1000 gallons) is
computed using the formula:
NCR = C/F, • SIR—
£
n=1
where: NCR = Normalized county industrial residual oil consumption
CIF, = Estimated county residual oil consumption by industrial sources
(computed below)
SIR = Reported State industrial area source residual oil consumption
(computed below)
c «= Number of counties in State
SIR is computed using the equation:
SIR = TSR - SPR
If SIR < 0, then set SIR = 0.
3-33
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where: TSR = Total State industrial residual oil consumption (computed below)
SPR = State industrial point source residual oil consumption (computed
below)
SPR is computed using the formula:
SCC
SPR = £ RPISn
where: SCC = AIRS Facility points for SCCs
1-02-004-"
3-90-004-"
2-02-005-"
RPIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
TSR is computed using the equation:
TSR = SOCR + SRI
where: SOCR = State residual oil consumption at oil companies (computed
below)
SRI = State residual oil deliveries to industry (computed below)
SRI is computed using the equation:
SRI = State Industrial Residual Oil +
State All Other Residual Oil
SOCR is computed using the equation:
SOCR = SRO + SPHR
If SOCR < 0, then set SOCR = 0.
where: SRO = State residual oil deliveries to oil companies
SPHR = State residual oil used for process heating at oil companies
(computed below)
3-34
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SPRH is computed using the equation:
SRO
SPHR = RRO •
where: RRO = Residual oil consumed at refineries by PAD district
SRO = State residual oil deliveries to oil companies
s = Number of States in a PAD district
An estimate of County Industrial Residual Fuel Oil consumption (GIF,) is derived with the
following formula:
SIC
= £
7=1
where: GIF, = Estimated county industrial consumption of residual oil
SIC = SIC codes 20 through 39
CAEj = County area source employment for SICj
FIR,j = State fuel intensity ratio: a measure of fuel use intensity per
employee for residual oil by SIC category j
is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
CPEj = Point source employment in county for SIC category
State fuel intensity ratio (FIR^ is computed using the formula:
E,
where: F, = State consumption of residual oil by SIC category j
E.' = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
3-35
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NOTE: If input data are not available to compute State fuel intensity ratios, then RFR,j
is substituted for FIR^ in the formula used to compute estimates of county
industrial residual oil fuel consumption CIFV In this case the formula used is:
SIC
V = £ CAEJ '
where: RFR,, = Regional fuel intensity ratio for residual oil by SIC category j
(computed below)
RFR,: is computed using the formula:
where: RF,j = Regional consumption of residual oil by SIC category j
REj = Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFR1( is substituted for FIR,, in the formula used to compute estimates of
county industrial residual oil fuel consumption GIF,. In this case the formula
used is:
SIC
£
CAEj - NFRy
where: NFR,j = National fuel intensity ratio for residual oil by SIC category j
(computed below)
is computed using the formula:
HFR -
where: NF1{ = National consumption of residual oil by SIC category j
NEj = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
3-36
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Residual Oil Emission Factors -
Emission factors are found in AP-42, Table 1.3-1.8 For SO2, the average sulfur content for No.
6 fuel oil is obtained from Heating Oils.13
Natural Gas
Originally, the method used for determining natural gas consumption by industrial area sources
combined natural gas use at boilers and natural gas use at 1C engines. However, the AMS
methodology has been modified so that these two uses of natural gas are considered separately. In
addition, LPG was also included in the natural gas estimate. The AMS methodology will estimate LPG
consumption as a separate entity. The following sections describe the steps used to estimate natural
gas consumption for boilers and 1C engines.
Natural Gas Consumed at Boilers -
The methodology for determining natural gas consumption by industrial area sources at boilers
consists of two steps. County industrial fuel consumption for natural gas is calculated on a county
basis, county values are summed, and then normalized with the State published value.3 Sources of
inputs and normalization are discussed below.
The first step in the methodology is to determine industrial natural gas consumption by county.
This is accomplished by adjusting county area source employment figures for SIC categories 20
through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel -- in this case natural gas -
for each SIC category by the respective State employment. (If State data are not available, regional
data are used. If regional data are not available, national data are used.) County area source
consumption is then summed for all counties to obtain State area source consumption for natural gas.
County consumption values are then normalized to agree with the State-level calculated
industrial area source consumption values for natural gas. Reported industrial area source
consumption is calculated by subtracting the point source industrial natural gas consumption as
reported to AIRS/FS from the adjusted State total natural gas consumption. The adjusted State total
natural gas consumption is obtained by subtracting the natural gas used for chemical feedstock
purposes from the published State total industrial natural gas consumption. The AMS methodology
considers four chemicals to be the most important for chemical feedstock purposes. These are:
acetylene, ammonia, carbon black, and methanol.
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial
natural gas consumption for States for each year is found in DOE's Natural Gas Annual.17 Information
concerning the use of natural gas as a chemical feedstock te found in the Directory of Chemical
Producers25 and information concerning the amounts of the four chemicals produced in a given year is
found in the Chemical & Engineering News26 and Synthetic Organic Chemicals.27 Information
concerning consumption of natural gas by SIC category is found in DOE's Manufacturing Energy
Consumption Survey23 and is used to calculate fuel intensity factors. State industrial point source data
are taken directly from AIRS/FS Point Source Data Files.20
3-37
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Natural Gas Equations (Boilers) -
A normalized estimate of County Industrial Natural Gas Consumption in Boilers (NCGB) (million
cubic feet) is computed using the formula:
NCGB = C/F3 - SIGB
n=1
where: NCGB = Normalized county industrial natural gas consumption in boilers
CIF3 = Estimated county natural gas consumption by industrial sources
(computed below)
SIGB = Reported State industrial area source natural gas consumption
in boilers (computed below)
c = Number of counties in State
SIGB is computed using the formula:
SIGB = TSGB - SPGB
If SIGB < 0, then set SIGB = 0.
where: TSGB = Total State industrial natural gas consumption in boilers
(computed below)
SPGB = State industrial point source natural gas consumption in boilers
(computed below)
The equation to compute SPGB is as follows:
sec
£
n=i
SPGB = £ GBPISn
where: SCC = AIRS Facility points for SCCs
1-02-006-"
3-90-006-"
GBPIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
TSGB is computed using the equation:
TSGB = TSPG - TSFG
where: TSPG = Published State total industrial natural gas
3-38
-------
TSFG = Total State natural gas used for feedstock purposes (computed
below)
TSFG is computed using the equation:
TSFG =
TAC-TCP'PNG^
n ' *" n
1,000,000
PCC,
n
where: ch = 1 for Acetylene; 2 for Ammonia; 3 for Carbon Black; 4 for
Methanol
TAG = Typical amounts of natural gas required to produce a given
chemical (cubic feet)
TCP = Amount of chemical produced in current year (short tons)
PNG = Percent (%) production capacity using natural gas process
PCC = Percent (%) production capacity for a State by chemical
An estimate of County Industrial Natural Gas Fuel consumption (CIF3) is derived with the
following formula:
SIC
£
7=1
CIF3 = £ CAEj - FIR3J
where: CIF3 = Estimated county industrial consumption of natural gas
SIC = SICs 20 through 39
= County area source employment for SICj
= State intensity ratio: a measure of fuel use intensity per
employee for natural gas by SIC category j
is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
= Point source employment in county for SIC category j
State fuel intensity factor (FIR^) is computed using the formula:
- f
3-39
-------
where: F,
3j
State consumption of natural gas by SIC category j
Total employment in State for SIC category j in year of most
recent Census of Manufacturers
NOTE: If input data are not available to compute State fuel intensity ratios, then
is substituted for FIR^ in the formula used to compute estimates of county
industrial natural gas fuel consumption CIF3. In this case the formula used is
SIC
C/F^ =
CAEj - RFR3J
where:
Regional fuel intensity ratio for natural gas by SIC category j
(computed below)
RFR.JJ is computed using the formula:
RE,
where: RF.
RE
3j
Regional consumption of natural gas by SIC category j
Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFRgj is substituted for FIR^ in the formula used to compute estimates of
county industrial natural gas fuel consumption CIF3. In this case the formula
used is:
SIC
CAEj - NFR3J
where:
National fuel intensity ratio for natural gas by SIC category j
(computed below)
is computed using the formula:
NFRy =
NE,
3-40
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where: NF^ = National consumption of natural gas by SIC category j
NEj = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
Natural Gas Emission Factors (Boilers) -
Boiler emission factors are obtained from AP-42, Table 1.4-1" for natural-gas-fired industrial
boilers of the 10 to 100 million Btu range.
Natural Gas Consumed at 1C Engines -
The methodology for determining natural gas consumption by industrial area sources 1C
engines consists of two steps. County industrial fuel consumption for natural gas is calculated on a
county basis, county values are summed, and then the figures are normalized with the State published
value.3 Sources of inputs and normalization are discussed below.
The first step in the methodology is to determine industrial natural gas consumption by county.
This is accomplished by adjusting county area source employment figures for SIC categories 20
through 39 by a fuel intensity factor. For the purpose of this calculation, county area source
employment is defined as the difference between total county employment and point source
employment for each SIC category. The fuel intensity ratio is a measure of fuel use intensity per
employee, which is determined by dividing the State consumption of fuel - in this case natural gas -
for each SIC category by the respective State employment. If State data are not available, regional
data are used. If regional data are not available, national data are used. County area source
consumption is then summed for all counties to obtain State area source consumption for natural gas.
County consumption values are then normalized to agree with the State-level calculated
industrial area source consumption values for natural gas. Reported industrial area source
consumption is calculated by subtracting the point source industrial natural gas consumption as
reported to AIRS/FS from the published State total natural gas consumption for two categories:
pipeline fuel, and lease and plant fuel.
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial
natural gas consumption for States for each year is found in DOE's Natural Gas Annual.17 Information
concerning consumption of natural gas by SIC category is found in DOE's Manufacturing Energy
Consumption Survey23 and is used to calculate fuel intensity factors. State industrial point source data
are taken directly from AIRS/FS Point Source Data Files.20
Natural Gas Equations (1C Engines) -
A normalized estimate of County Industrial Natural Gas Consumption in 1C Engines (NCGE)
(million cubic feet) is computed using the formula:
NCGE = C/F3 • SIGE
3-41
-------
where: NCGE = Normalized county industrial natural gas consumption in 1C
engines
CIF3 = Estimated county natural gas consumption by industrial sources
(computed below)
SIGE = Reported State industrial area source natural gas consumption
in 1C engines (computed below)
c = Number of counties in State
SIGE is computed using the formula:
SIGE = TSLP + TSPF - SPGE
If SIGE < 0, then set SIGE = 0.
where: TSLP = Published State total lease and plant fuel natural gas
consumption
TSPF = Published State total pipeline fuel natural gas consumption
SPGE = Reported State industrial point source natural gas consumption
for 1C engines (computed below)
SPGE is computed using the formula:
sec
£
77 = 1
SPGE = £ GEP/Sn
where: SCC = AIRS Facility points for SCC 2-02-002-"
GEPIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
An estimate of County Industrial Natural Gas Fuel consumption (CIF-j) is derived with the
following formula:
SIC
CIF3 = £ CAEj - HR3J
y=i
where: CIF3 = Estimated county industrial consumption of natural gas
SIC = SIC codes 20 through 39
= County area source employment for SIC{
= State fuel intensity ratio: a measure of fuel use intensity per
employee for natural gas by SIC category j
3-42
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CAEj is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
= Point source employment in county for SIC category j
State fuel intensity factor (FIR^) is computed using the formula:
FIR3I =
where: F^ = State consumption of natural gas by SIC category j
Ej = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
NOTE: If input data are not available to compute State fuel intensity ratios, then
is substituted for FIR^ in the formula used to compute estimates of county
industrial natural gas fuel consumption CIF3. In this case the formula used is
SIC
CAEI
where: RFR, = Regional fuel intensity ratio for natural gas by SIC category j
(computed below)
is computed using the formula:
where: RF^ = Regional consumption of natural gas by SIC category j
RE, * Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
3-43
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NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFRgj is substituted for FIR^ in the formula used to compute estimates of
county industrial natural gas fuel consumption CIF3. In this case the formula
used is:
SIC
CIF3J = £ CAEj -
where: NFR^ = National fuel intensity ratio for natural gas by SIC category j
(computed below)
j is computed using the formula:
where: NF^ = National consumption of natural gas by SIC category j
NE, = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
Natural Gas Emission Factors (1C Engines) -
For gas pipelines and plants, emission factors are obtained for SCC 2-02-002-01 (Turbines)
and SCC 2-02-002-02 (1C Engines) from AIRS/FS Point Source Data Files.20 Emission factors are
weighted according to the total AIRS/FS fuel consumed by each type.
In order to obtain weighted emission factors for this category, the amount of natural gas
consumption must be first obtained from AIRS/FS for SCC 2-02-002-01 and 2-02-002-02. The following
general equation is then used to compute weighted emission factors:
(EFSCC1 ' F^SCCl) + (EFSCC2
w
(FCSCC1 + FC
SCC1 SCC2
where: EFW = Weighted Emission factor for a given pollutant
EFscci = AP-42 emission factor for the first SCC in the series
FCscci « Fuel consumption from AIRS/FS for the first SCC in the series
LPG
Originally, the method used for determining natural gas consumption by industrial area sources
combined natural gas and LPG. However, the AMS methodology has been modified so that these two
types of fuels are considered separately.
3-44
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The methodology for determining LPG consumption by industrial area sources consists of two
steps. County industrial fuel consumption for LPG is calculated on a county basis, county values are
summed, and then normalized with the State published value.3 Sources of inputs and normalization are
discussed below.
The first step in the methodology is to determine industrial LPG consumption by county. This is
accomplished by adjusting county area source employment figures for SIC categories 20 through 39 by
a fuel intensity factor. For the purpose of this calculation, county area source employment is defined as
the difference between total county employment and point source employment for each SIC category.
The fuel intensity ratio is a measure of fuel use intensity per employee, which is determined by dividing
the State consumption of fuel - in this case LPG - for each SIC category by the respective State
employment. (If State data are not available, regional data are used. If regional data are not available,
national data are used.) County area source consumption is then summed for all counties to obtain
State area source consumption for LPG.
County consumption values are then normalized to agree with the State-level calculated
industrial area source consumption values for LPG. Reported industrial area source consumption is
calculated by subtracting the point source industrial LPG consumption as reported to AIRS/FS20 from
the published State total LPG consumption.
Sources of information on county total and point source employment figures for SIC categories
20 through 39 are obtained from the Census Bureau's County Business Patterns.22 Total industrial
LPG consumption for States for each year is found in DOE's State Energy Data Report.7 Information
concerning consumption of LPG by SIC category is found in DOE's Manufacturing Energy Consumption
Survey23 and is used to calculate fuel intensity factors. State industrial point source data are taken
directly from AIRS/FS Point Source Data Files.20
LPG Equations -
A normalized estimate of County Industrial LPG Consumption (NCLP) (in 1000 gallons) is
computed using the formula:
NCLP = GIF* - —SILP
where: NCLP = Normalized county industrial LPG consumption
CIF5 = Estimated county LPG consumption by industrial sources
(computed below)
SILP = Reported State industrial area source LPG consumption
(computed below)
c = Number of counties in State
SILP is computed using the formula:
SILP = TSLP + TSPF - SPGE
If SILP < 0, then set SILP = 0.
3-45
-------
where: TSLP = Published State total lease and plant fuel LPG consumption
TSPF = Published State total pipeline fuel LPG consumption
SPGE = Reported State industrial point source natural gas consumption
for 1C engines (computed below)
SPGE is computed as follows:
sec
SPGE = £ LPPISn
where: SCO = AIRS Facility points for SCCs
1 -02-010-"
2-02-0 10-"
3-90-01 0-"
LPPIS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
An estimate of County Industrial LPG Fuel consumption (CIF5) is derived with the following
formula:
SIC
£
CIF = CAEj • FIR5J
where: CIF6 = Estimated county industrial consumption of LPG
SIC = SIC codes 20 through 39
= County area source employment for SICj
= State fuel intensity ratio: a measure of fuel use intensity per
employee for LPG by SIC category j
CAEj is computed using the formula:
CAEj = TCEj - CPEj
where: TCEj = Total employment in county for SIC category j
= Point source employment in county for SIC category j
State fuel intensity ratio (FIR^ is computed using the formula:
FIR,, =
3-46
-------
where: F^ = State consumption of LPG by SIC category j
EJ = Total employment in State for SIC category j in year of most
recent Census of Manufacturers
NOTE: If input data are not available to compute State fuel intensity ratios, then RFR5j
is substituted for FIR^ in the formula used to compute estimates of county
industrial LPG fuel consumption CIF6. In this case the formula used is:
SIC
£
CIFS = £ CAEj • RFR5J
where: RFR^ = Regional fuel intensity ratio for LPG by SIC category j
(computed below)
is computed using the formula:
where: RF^ = Regional consumption of LPG by SIC category j
RE, = Total employment in census region for SIC category j in year of
most recent Census of Manufacturers
NOTE: If input data are not available to compute regional fuel intensity ratios, then
NFRgj is substituted for FIR^ in the formula used to compute estimates of
county industrial LPG fuel consumption CIFS. In this case the formula used is:
SIC
CIF5 = £ CAEj - NFR5J
where: NFR^ = National fuel intensity ratio for LPG by SIC category j
(computed below)
is computed using the formula:
3-47
-------
where: NF^ = National consumption of LPG by SIC category j
NEj = Total employment in nation for SIC category j in year of most
recent Census of Manufacturers
LPG Emission Factors -
Emission factors are found in AP-42, Table 1.5-1.8
Wood
A method to estimate area source emissions from industrial wood combustion sources may be
developed in the future.
Industrial Coke
A method to estimate area source emissions from industrial wood combustion sources may be
developed in the future.
Process Gas
A method to estimate area source emissions from industrial wood combustion sources may be
developed in the future.
SULFUR CONTENT
Anthracite Coal
Sulfur content of anthracite coal for each county is not computed. A national value is input and
used without any manipulation.3 For the purpose of this calculation the sulfur content of anthracite coal
is assumed to be 0.7 percent."
AS = NIV
where: AS = County anthracite coal sulfur content for all consumer
categories
NIV = National input value for sulfur content of anthracite coal
Bituminous Coal
Residential/Commercial -
The original methodology called for estimating a weighted average sulfur content for all source
categories, namely, residential coal combustion, commercial/institutional coal combustion, and industrial
coal combustion3. However, the AMS methodology has been modified to estimate weighted average
sulfur contents for residential and commercial/institutional separately from the industrial sector. The
average sulfur content for the appropriate sector is taken from Coal Production.8 District averages are
then weighted by coal shipment data from the Coal Distribution: January-December10 report. Weight of
sulfur from commercial point sources is obtained from AIRS/FS20.
3-48
-------
A weighted average sulfur content of bituminous coal consumed at residential and commercial
sources is calculated as follows:
CWRCS = SSRC
NOTE: If SSRC > 7 percent, then set SSRC = 3 percent
where: CWRCS
SSRC
County weighted sulfur content of bituminous coal consumed at
residential and commercial sources [% sulfur (S)]
State weighted sulfur content of bituminous coal consumed at
residential and commercial sources (computed below)
SSRC is computed using the formula:
P
SSRC =
RCSd • SRBd - BPS
SRBd- BPC
where: RCS
SRB
BPS
BPC
NOTE:
Average sulfur content (% S) of bituminous coal shipped from
production district/district grouping p for use by residential and
commercial sources (computed below)
Bituminous shipments to State from production district/district
grouping p for residential and commercial use
Weight of sulfur in bituminous coal consumed in State by
commercial point sources (computed below)
Bituminous coal consumed in the State by commercial point
sources (computed below)
BPC >
SRB
OR
BPS > £ RCSd • SRBd
3-49
-------
then use the following equation:
RCS is computed as follows:
RCSd-SRBd
SSRC = -^
E SRBd
SRBd-RCSCd
RCSd = -^
E
where: p
RCSC
1 for production district # 1
2 for production district # 2
3 for production district # 3 and 6
4 for production district # 4
5 for production district # 7
6 for production district # 8
7 for production district # 9
8 for production district # 10
9 for production district #11
10 for production district # 12
11 for production district # 13
12 for production district # 14
13 for production district #15
14 for production district #16 and 17
15 for production district #18
16 for production district #19
17 for production district # 20
18 for production district # 21
19 for production district # 22 and 23
Sulfur content (% S) of bituminous coal shipped from
production district/district grouping p for use by residential and
commercial sources
3-50
-------
BPS is computed using the formula:
sec
BPS = £ FSCCn - BPCSn
where: SCC = AIRS Facility points for SCCs 1 -03-002-" and 1 -03-003-"
FSCC = Sulfur content of bituminous coal at commercial point sources
in the AIRS/FS Point Source Data Files20 summed by State
BPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
BPC is computed using the formula:
SCC
£
/7=1
BPC = £ BPCSn
where: SCC = AIRS Facility points for SCCs 1-03-002-" and 1-03-003-"
BPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
Industrial -
The original methodology called for estimating a weighted average sulfur content for all source
categories, namely, residential coal combustion, commercial/institutional coal combustion, and industrial
coal combustion3. However, the AMS methodology has been modified to estimate weighted average
sulfur contents for residential and commercial/institutional separately from the industrial sector. The
average sulfur content for the appropriate sector is taken from Coal Production.9 District averages are
then weighted by coal shipment data from the Coal Distribution: January-December10 report. The
weight of sulfur from commercial point sources is obtained from AIRS/FS20.
A weighted average sulfur content of bituminous coal consumed at industrial sources is
calculated as follows:
CWIS = SSI
NOTE: If SSI > 7 percent, then set SSI = 3 percent
where: CWIS = County weighted sulfur content of bituminous coal consumed at
industrial sources (% S)
SSI = State weighted sulfur content of bituminous coal consumed at
industrial sources (computed below)
3-51
-------
SSI is computed using the formula:
( P
£ /s^-s/aj - IPS
ssi = *'
where: IS
SIB
IPS
IPB
NOTE:
£ &Bd-IPB
Average sulfur content (% S) of bituminous coal shipped from
production district/district grouping p for use by industrial
sources (computed below)
Bituminous shipments to State from production district/district
grouping p for industrial use
Weight of sulfur in bituminous coal consumed in State by
industrial point sources (computed below)
Bituminous coal consumed in the State by industrial point
sources (computed below)
If IPB > £ SIBd
OR
// IPS > £ IS
-------
ISd is computed using the formula:
SIBd - ISCd
where: p 1 for production district # 1
2 for production district # 2
3 for production district # 3 and 6
= 4 for production district # 4
5 for production district # 7
6 for production district # 8
7 for production district # 9
8 for production district #10
9 for production district # 11
10 for production district #12
11 for production district #13
12 for production district # 14
13 for production district # 15
= 14 for production district* 16 and 17
= 15 for production district #18
16 for production district # 19
= 17 for production district #20
18 for production district # 21
19 for production district # 22 and 23
ISC = Sulfur content (% S) of bituminous coal shipped from
production district/district grouping p for use by industrial
sources
IPS is computed using the formula:
sec
IPS = £ FSCIn - IPBSn
where: SCC = AIRS Facility points for SCCs
1-02-002-"
1-02-003-"
3-90-002-"
3-90-003-"
PSCI = Sulfur content of bituminous coal at industrial point sources in
the AIRS/FS Point Source Data Files20 summed by State
I PBS = Annual throughput of bituminous coal at industrial point sources
in the AIRS/FS Point Source Data Files20 summed by State
3-53
-------
IPB is computed using the formula:
sec
IPB = £ IPBSn
where: SCC = AIRS Facility points for SCCs
1-02-002-"
1-02-003-"
3-90-002-"
3-90-003-"
IPBS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
Distillate Oil
Sulfur content of distillate oil is a county statistical value. This value is not computed or
manipulated at the present time. Average sulfur contents for No. 1, No. 2, and No. 4 fuel oils are taken
from Heating Oils.13
CDS = SDS
where: CDS = County distillate oil for all fuel categories
SDS = State input value for sulfur content of distillate oil
Residual Oil
Sulfur content of residual oil is a county statistical value. This value is not computed or
manipulated at the present time. Average sulfur content for No. 6 fuel oil is taken from Heating Oils13.
CRS = SRS
where: CRS = County residual oil for all fuel categories
SRS = State input value for sulfur content of residual oil
ASH CONTENT
Anthracite Coal
Ash content of anthracite coal for each county is not computed. A national value is input and
used without any manipulation.9 For the purpose of this calculation ash content is assumed to be 11.0
percent.
AA = NIV
where: AA = County anthracite coal ash content for all consumer categories
3-54
-------
NIV = National input value for ash content of anthracite coal
Bituminous Coal
Residential/Commercial -
The original methodology called from estimating a weighted average ash content for all source
categories, namely, residential coal combustion, commercial/institutional coal combustion, and industrial
coal combustion3. However, the AMS methodology has been modified to estimate weighted average
ash contents for residential and commercial/institutional separately from the industrial sector. The
average ash content for the appropriate sector is taken from Coal Production.9 District averages are
then weighted by coal shipment data from the Coal Distribution: January-December10 report. Weight of
ash from commercial point sources is obtained from AIRS/FS20.
A weighted average ash content of bituminous coal consumed at residential and commercial
sources is calculated as follows:
CWRCA = ASRC
NOTE: If ASRC > 25 percent, then set ASRC = 15 percent
where: CWRCA
ASRC
County weighted ash content of bituminous coal consumed at
residential and commercial sources [% ash (A)]
State weighted ash content of bituminous coal consumed at
residential and commercial sources (computed below)
ASRC is computed using the formula:
ASRC =
RCA
- BPA
SRB - BPC
where: RCA
SRB
BPA
BPC
Average ash content (% A) of bituminous coal shipped from
production district/district grouping p for use by residential and
commercial sources (computed below)
Bituminous shipments to State from production district/district
grouping p for residential and commercial use
Weight of ash in bituminous coal consumed in State by
commercial point sources (computed below)
Bituminous coal consumed in the State by commercial point
sources (computed below)
3-55
-------
NOTE:
If BPC >
SRB
OR
If BPA > £ RCAd - SRBd
then use the equation:
£ RCAd-SRBd
ASRC = £1
p
E
RCA is computed as follows:
£ SRBd-RCACd
RCA = -^
£ SRBd
where: p
1 for production district # 1
2 for production district # 2
3 for production district # 3 and 6
4 for production district # 4
5 for production district # 7
6 for production district # 8
7 for production district # 9
8 for production district #10
9 for production district #11
10 for production district #12
11 for production district #13
12 for production district #14
13 for production district #15
3-56
-------
14 for production district # 16 and 17
15 for production district # 18
16 for production district # 19
1 7 for production district # 20
= 18 for production district #21
19 for production district # 22 and 23
RCAC = Ash content (% A) of bituminous coal shipped from production
district/district grouping p for use by residential and commercial
sources
BPA is computed using the formula:
sec
£
n=1
BPA = £ FACCn • BPCSn
where: SCC = AIRS Facility points for SCCs
1-03-002-"
1-03-003-"
FACC = Ash content of bituminous coal at commercial point sources in
the AIRS/FS Point Source Data Files20 summed by State
BPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
BPC is computed using the formula:
SCC
BPC = £ BPCSn
where: SCC = AIRS Facility points for SCCs 1-03-002-" and 1-03-003-"
BPCS = Annual throughput at commercial point sources in the AIRS/FS
Point Source Data Files20 summed by State
Industrial -
The original methodology called for estimating a weighted average ash content for all source
categories, namely, residential coal combustion, commercial/institutional coal combustion, and industrial
coal combustion3. However, the AMS methodology has been modified to estimate weighted average
ash contents for residential and commercial/institutional separately from the industrial sector. The
average ash content for the appropriate sector is taken from Coal Production." District averages are
then weighted by coal shipment data from the Coal Distribution: January-December10 report. Weight of
ash from industrial point sources is obtained from AIRS/FS20.
3-57
-------
A weighted average ash content of bituminous coal consumed at industrial sources is
calculated as follows:
CWIA = ASI
NOTE: If ASI > 25 percent, then set ASI = 15 percent.
where: CWIA
ASI
County weighted ash content of bituminous coal consumed at
industrial sources (% A)
State weighted ash content of bituminous coal consumed at
industrial sources (computed below)
ASI is computed using the formula:
P
where: IA
SIB
IPA
IPB
IA - SIB - IPA
SIBd - IPB
Average ash content (% A) of bituminous coal shipped from
production district/district grouping for use by industrial sources
(computed below)
Bituminous shipments to State from production district/district
grouping p for industrial use
Weight of ash in bituminous coal consumed in State by
industrial point sources
Bituminous coal consumed in the State by industrial point
sources
NOTE:
If IPB >
SIB
OR
If IPA >
IA - SIB
3-58
-------
then use the equation:
P
E
ASI = £1
E
IA is computed using the formula:
P
SIBd - IACd
E
where: p 1 for production district # 1
2 for production district # 2
3 for production district # 3 and 6
4 for production district # 4
5 for production district # 7
6 for production district # 8
= 7 for production district # 9
8 for production district # 10
= 9 for production district #11
10 for production district #12
= 11 for production district #13
= 12 for production district #14
13 for production district # 15
14 for production district # 16 and 17
15 for production district # 18
16 for production district # 19
= 17 for production district # 20
18 for production district # 21
19 for production district # 22 and 23
IAC = Ash content (% A) of bituminous coal shipped from production
district/district grouping p for use by industrial sources
I PA is computed using the formula:
SCC
IPA = £ FACIn • IPBSa
3-59
-------
where: SCC = AIRS Facility points for SCCs 1 -03-002-" and 1-03-003-**
FACI = Ash content of bituminous coal at industrial point sources in the
AIRS/FS Point Source Data Files20 summed by State
IPBS = Annual throughput of bituminous coal at industrial point sources
in the AIRS/FS Point Source Data Files20 summed by State
IPB is computed as follows:
SCC
IPB = £ IPBSn
where: SCC = AIRS Facility points for SCCs
1-02-002-"
1-02-003-"
3-90-002-"
3-90-003-"
IPBS = Annual throughput at industrial point sources in the AIRS/FS
Point Source Data Files20 summed by State
3-60
-------
SECTION 4
MOBILE SOURCES
Mobile sources which contribute to area source emissions are divided into the following five
major categories: Highway Vehicles, Off-Highway Vehicles, Railroad Locomotives, Aircraft, and Marine
Vessels. For each of the above categories, methodologies for activity level and emission factor
estimation are discussed.
HIGHWAY VEHICLES
AMS segregates motor vehicles into the following eight EPA vehicle categories on the basis of
use and gross vehicle weight for the purpose of calculating emissions:
• Light-Duty Gasoline Vehicles (< 8,500 Ib) LDGV
• Light-Duty Gasoline Trucks -1 (:£ 6,000 Ib) LDGT1
- Light-Duty Gasoline Trucks - 2 (> 6,000 & <, 8,500 Ib) LDGT2
• Heavy-Duty Gasoline Vehicles (> 8,500 Ib) HDGV
• Motorcycles (3 wheels or less and < 1,500 Ib) MC
• Light-Duty Diesel Vehicles (5 8,500 Ib) LDDV
• Light-Duty Diesel Trucks (<, 8,500 Ib) LDDT
• Heavy-Duty Diesel Vehicles (> 8,500 Ib) HDDV
LDGV are defined as gasoline powered passenger vehicles weighing 8,500 pounds or less.
LDGT1 include gasoline cargo vehicles weighing 6,000 pounds or less. LDGT2 include gasoline cargo
vehicles weighing between 6,001 and 8,500 pounds. Heavy-duty vehicle categories separate diesel
and gasoline powered trucks and buses weighing more than 8,500 pounds. Motorcycles are defined as
any motor vehicle designed to travel with not more than three wheels in contact with the ground, and
weighing less than 1,500 pounds. LDDV are defined as diesel powered passenger vehicles weighing
8,500 pounds or less. LDDT include diesel cargo vehicles weighing 8,500 pounds or less.
While vehicle miles travelled (VMT) are determined for each vehicle class and road class, fuel
consumption is determined only for each vehicle class. Emission factors in grams per mile obtained
from the execution of the MOBILE28 model are applied so as to determine emissions for vehicle type
and speed class. VMT is determined for the following road classes:
4-1
-------
Assumed Speed (mph)
Road Class
55
55
55
55
55
55
55
45
45
45
19.6
19.6
Urban Interstate
Rural Interstate
Urban Other Freeways and Expressways
Urban Other Principal Arterials
Rural Other Principal Arterials
Urban Minor Arterials
Rural Minor Arterials
Rural Major Collector
Rural Minor Collector
Rural Local
Urban Collector
Urban Local
Development of Fractional Distribution of VMT by Road Class and Vehicle Type (Speed Class
File)
The algorithm used to compute the fractional distribution of VMT by road class assumes that
the VMT by functional class for a given county is proportional to that county's road miles by functional
class. These fractional distributions are applied to the normalized VMT by county (discussed in the
next section) to calculate the VMT by vehicle type and functional road class used to estimate vehicle
emissions.29 The methodology to calculate the fractional distribution of county VMT differs for HDDV
since much of the VMT of these vehicles is accrued outside the county of registration.
County road miles by functional class may be obtained from the Federal Highway
Administration (FHWA).30 State VMT by functional class is reported in Highway Statistics.31
In order to compute the Fractional Distribution of County VMT by road class/speed class i
(FCVMTiT) for all vehicle types other than HDDV, the following equations are used:
SVMT,
CRM.
i
FCVMTliT =
SRM,
E E SVMTn,
/n=1 n=1
CRM.
n,m
n,m
SRM,
n.m
where: FCVMTt
SVMT,
Estimated fractional distribution of county VMT by road
class/speed class i
Published total of State VMT by functional class (from Highway
Statistics31)
Functional Road Class
(Interstate Rural
Other Principal Arterial Rural
Minor Arterial Rural
4-2
-------
Major Collector Rural
Minor Collector Rural
Local Rural
Interstate Urban
Other Freeways and Expressways Urban
Other Principal Arterial Urban
Minor Arterial Urban
Collector Urban
Local Urban)
1 for LDGV
2forLDGT 1
3forLDGT 2
4 for HDGV
5 for MC
6 for LDDV
7 for LDDT
= Road mileage by county for functional road class iw
SRM, = Road mileage by State for functional road class i x
c = number of counties in the State
Since HDDV behavior is often characterized by cross-country travel, many of the VMT of these
vehicles are accrued outside the county of registration. To account for this behavior, VMT (and fuel
consumption) estimates are calculated separately for long-range travel and short-range travel.29
The annual miles travelled and percentage of the miles travelled outside the State for all diesel
trucks weighing at least 8,500 pounds (gross vehicle weight) are extracted from the data in the Truck
Inventory and Use Survey (TIUS)32. VMT categories are estimated using the above data and the
following equations:
Total VMT = annual miles • stratum expansion factor
Long Range VMT = annual miles • percent of travel outside State • stratum
expansion factor
Short Range VMT = Total VMT - Long Range VMT
The stratum expansion factor is a ratio used to expand the vehicle data from the sample size in
TIUS to each State's vehicle populations. State long range totals are summed to form the national
HDDV long range VMT pool.
The national long range VMT pool is then allocated to the county level according to the fraction
of the total State mileage of the National Network located within each county line. The National
Network is a set of highways on which large trucks are ensured travel rights. Since data are available
on county roadway mileage by functional class, and the National Network is a subset of Federal Aid
Primary (FAP) System, State totals of National Network mileages are allocated to counties on the basis
of county mileage of each of the major FAP functional classes: Interstate, Major Arterials, and
Freeways.31
Short range VMT is allocated to the county level on the basis of truck registrations. Short
range VMT and long range VMT are then totalled for each county.
4-3
-------
Since the behavior of HDDV differs significantly from that of other vehicle types, VMT is
allocated to speed classes (limited access, urban, and rural) in a different manner. Each county's
HDDV long range VMT is assumed to occur on limited access roads; short range HDDV VMT is divided
equally between rural and urban roads.
Registration data and National Network mileage are taken from FHWA Highway Statistics.31
County roadway mileages by functional class are also obtained from FHWA.30 VMT measurements are
obtained from the TIUS.32
The fraction of HDDV (vehicle type 8) county VMT due to long range travel for functional road
class i (FCVMT,8lr) is computed below:
FCVMT,
/»8'*' c /
n.m
where: FCVMT
,8lr
SLRVMT
8
Ir
CLRMj
SLRM
Estimated fraction of HDDV county VMT for functional road
class i
Sum of functional class road miles (i) within a State considered
to be long range *
Functional Road Class
(Interstate Rural
Other Principal Arterial Rural
Minor Arterial Rural
Interstate Urban
Other Freeways and Expressways Urban
Other Principal Arterial Urban)
HDDV
1 = Long Range
Road mileage by county for functional road class (i) considered
to be long range "
Road mileage by State for functional road class (i) considered
to be long range x
The fraction of HDDV county VMT due to short range travel for functional road class
J is computed below:
SSVMT, • °SRM>
FCVMT
IBsr
"
E E SSVMT,
CSRM.
n,m
4-4
-------
where: SSVMT, = Sum of functional class road miles (i) within a State considered
to be short range K
i = Functional Road Class
(Major Collector Rural
Minor Collector Rural
Local Rural
Minor Arterial Urban
Collector Urban
Local Urban)
8 = HDDV
sr 2 = Short Range
CSRM, = Road mileage by county for functional road class (i) considered
to be short range x
SSRMj = Road mileage by State for functional road class (i) considered
to be short range M
County VMT by Vehicle Type-
The original methodology for computing VMT and fuel consumption for highway vehicles was
very complex and very difficult to utilize11. However, the methodology used for AMS has been
simplified without abandoning the basic concept altogether. That is, VMT and fuel consumption are
interrelated. Currently, the basic concept for computing VMT and fuel consumption for highway
vehicles is adapted from the MOBILES Fuel Consumption Model33. While the MOBILE3 Fuel
Consumption Model uses a moderately complex methodology to compute VMT and fuel consumption
for highway vehicles, the AMS methodology uses the same basic concept while maintaining a certain
simplicity. AMS attempts to use published data as benchmarks for the methodology whenever possible
(e.g., VMT and fuel consumption data as reported in Highway Statistics31. VMT as reported by State
Departments of Transportation).
VMT by vehicle type is obtained by multiplying the number of vehicles by vehicle type by model
year in each county by a mileage accumulation rate by model year. This estimated county VMT by
vehicle type is then normalized. The methodology for normalizing this VMT differs depending on the
availability of county-level measured-VMT from the State Department of Transportation (DOT). If this is
available, the VMT estimates are normalized based on these data. If State DOT VMT is not available,
the VMT is normalized for the appropriate State based on the State-by-State VMT reported in Highway
Statistics.31
Total State annual VMT estimates are found in Federal Highway Administration Highway
Statistics.31 County-level registrations are obtained from the R. L. Polk Company.34 Mileage
accumulation rates for each vehicle type by age are obtained from the latest version of the MOBILE28
model.
An estimate of county VMT by functional road class i and vehicle type T (ALLCVMTIT) (1000
VMT) is computed as follows:
ALLCVMT,T = FCVMTjj • NCVMTT
where: ALLCVMTiT - Estimated county VMT by functional road class i and
vehicle type T
4-5
-------
FCVMTIT = Fractional distribution of county VMT by road
class/speed class i,T (see previous section
"Development of Fractional Distribution of VMT by
Road Class and Vehicle Type")
NCVMTT = Normalized estimate of the county VMT by vehicle type
T (computed below)
T 1 for LDGV
2 for LDGT 1
3 for LDGT 2
4 for HDGV
5 for MC
6 for LDDV
7 for LDDT
The allocation of HDDV VMT to speed classes is different, and an estimate of county VMT by
functional road class i and vehicle type 8 (HDDV) (ALLCVMTJ8) (1000 VMT) is computed as follows:
ALLCVMTp = FCVMTIBr - NCVMTBr - CDFRACT,
where: FCVMT,8f = Fractional distribution of VMT to road class/speed class
(i) for vehicle type (T) -- HDDV (see "Development of
Fractional Distribution of VMT by Road Class and
Vehicle Type")
NCVMTg, = Normalized estimate of county VMT for HDDV
(computed below)
CDFRACTr = Fraction of heavy-duty diesel VMT by county for range
(0
r 1 = Long Range
2 = Short Range
The fraction of short range HDDV VMT by county (CDFRACT2) is calculated as follows:
CDFRACT2 = 1 - CDFRACT,
The fraction of long range HDDV VMT by county (CDFRACT,) is calculated as follows:
-- (CAWF • NLRVMT)
- • SSRVMT + (CAWF - NLRVMT}
where: CNNF = Fraction of national network truck miles by county (computed
below)
NLRVMT = National total of HDDV VMT outside of the State of
registration32
CT = Number of trucks in county > 26,000 Ib
4-6
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ST = Number of trucks in State > 26,000 Ib
SSRVMT = HDDV VMT within the State of registration32
Normalized Estimates of County VMT by Vehicle Type with State DOT VMT - Normalized county
estimates of VMT by highway vehicle type T (NCVMTT) (1000 VMT) is computed by the following
equation if county-level VMT are obtained from the State DOT:
NCVMT =
T
£ BCVMTn
n=-\
where: NCVMTT = Normalized estimated county VMT by highway vehicle type T
ECVMTT = Estimated county VMT for vehicle type T (computed below)
T 1 for LDGV
2forLDGT 1
3forLDGT 2
4 for HDGV
5 for MC
6 for LDDV
7 for LDDT
8 for HDDV
CVM = Annual VMT in county as reported by the State DOT
The equation to compute an estimate of county VMT (ECVMTT) for vehicle types other than
HDDV (T=8) is as follows:
ECVMTT -
E E E
/n=1 p=
where: T 1 for LDGV
2 for LDGT 1
3 for LDGT 2
4 for HDGV
5 for MC (See Motorcycle Section)
6 for LDDV
7 for LDDT
= Vehicle registrations for vehicle age (A) 1 through 20, vehicle
type (T), and county (c)
•= Mileage accumulation rate for vehicle age (A) 1 through 20 and
vehicle type (T)
4-7
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An estimate of county HDDV VMT (ECVMTg) is calculated using the equation:
ECVMTB = (— • SSRVMT\ + (CNNF - NLRVMT)
ST
where: CT = Number of trucks in county > 26,000 Ib34
ST = Number of trucks in State > 26,000 Ib M
SSRVMT = HDDV VMT within the State of registration32
CNNF = Fraction of national network truck miles by county (computed
below)
NLRVMT = National total of HDDV VMT outside of the State of
registration32
CNNF is calculated using the formula:
CFPM
SNN
£ CFPM,
CNNF = -?^-
NNM
where: CFPM = Miles of FAP road by county (computed below)
SNN = Amount of national network truck mileage in a State31
NNM = National total national network truck mileage31
The equation to compute CFPM is as follows:
CFPM = Interstate Rural +
Interstate Urban +
Other Principal Arterial Rural +
Other Principal Arterial Urban +
Other Freeways & Expressways Urban30
Normalized Estimates of County VMT by Vehicle Type without State DOT VMT - Normalized
county estimates of VMT by highway vehicle type T (NCVMTT) (1000 VMT) is estimated by the
following equation if county-level VMT is NOT obtained from the State DOT:
NCVMTf = -— ! • SVM
£ £ ECVM7m.n
11=1 OT=1
where: ECVMTT = Estimated county VMT for vehicle type T (computed below)
T 1 for LDGV
4-8
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SVM
2forLDGT 1
3forLDGT 2
4 for HDGV
5 for MC
6 for LDDV
7 for LDDT
8 for HDDV
Published total of State VMT31
The equation to compute an estimate of county VMT (ECVMTT) for vehicles other than HDDV
(T=8) is as follows:
W?n.r,c - MARnJ
ECVMTT- - T A
EEE
m=1 p=1 n=1
where: T
MAI
T
1 for LDGV
2forLDGT 1
3forLDGT 2
4 for HDGV
5 for MC (see Motorcycle Section)
6 for LDDV
7 for LDDT
Vehicle registrations for vehicle age (A) 1 through 20, vehicle
type (T), and county (c)
Mileage accumulation rate for vehicle age (A) 1 through 20 and
vehicle type (T)
An estimate of county HDDV VMT (ECVMTg) is calculated using the equation:
ECVMT6 = (— • SSRVMT\ + (CNNF • NLRVMT)
\ST )
where: CT
ST
SSRVMT
CNNF
NLRVMT
Number of trucks in county > 26,000 Ib34
Number of trucks in State > 26,000 Ib34
HDDV VMT within the State of registration32
Fraction of national network truck miles by county (computed
below)
National total of HDDV VMT outside of the State of
registration32
4-9
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CNNF is computed using the formula:
CFPM
•SNN
c
CNNF = -£!
NNM
where: CFPM = Miles of FAR road by county (computed below)
SNN = Amount of national network truck mileage in a State31
NNM = Total national network truck mileage
CFPM is computed using the equation:
CFPM = Interstate Rural +
Interstate Urban +
Other Principal Arterial Rural +
Other Principal Arterial Urban +
Other Freeways and Expressways Urban
Gasoline-Powered Vehicles: Fuel Consumption Methodology
Gasoline consumption of LDQV, LDGT1, LDGT2, HDGV, and MC is determined by allocating
total State highway gasoline consumption to the county level, based on VMT and miles per gallon
(mpg) values for the appropriate vehicle types.31
Total gasoline consumption reported for each State is allocated to counties using the
normalized VMT by vehicle type (NCVMTT) as discussed in the previous section. The normalized VMT
by vehicle type was calculated by one of two methods depending on the availability of State-submitted
data for VMT in each county. VMT is normalized using State DOT VMT estimates where available (see
previous section). For States where data were not available, the VMT is normalized based on the
State-by-State VMT reported in Highway Statistics31 (see previous section). A miles per gallon value is
applied to the normalized VMT by vehicle type, and this value is used to distribute total State highway
gasoline consumption to counties.31
Total State highway gasoline consumption, State annual VMT, and fuel efficiency estimates are
found in Federal Highway Administration Highway Statistics.31 County-level registrations are obtained
from the R. L. Polk Company.34 Mileage accumulation rates for each vehicle type by age are obtained
from the latest version of the MOBILE28 model.
4-10
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County gasoline consumption by highway vehicle type T (CHGCT) (1000 gallons) is estimated
by the following equation:
CHGC =
NCVMTT - MPGT
T - T
(NCVMTnn • MPGmJ
n=1 /n=1
TSH
where: CHGCj = Estimated county gasoline consumption by highway vehicle
typeT
NCVMTT = Normalized estimate of county-level VMT for vehicle type T
MPGr = Average mpg of fuel consumed31
TSH = Published total State highway gasoline consumption31
T 1 for LDGV
2forLDGT 1
SforLDGT 2
4 for HDGV
5 for MC
c = number of counties in State
The normalized estimate of county VMT is as previously calculated in "County VMT by Vehicle
Type."
Diesel-Powered Vehicles: Fuel Consumption Methodology
In general, diesel consumption of LDDV, LDDT, and HDDV is determined by allocating total
State highway diesel consumption to the county level based on VMT and miles per gallon values for the
appropriate vehicle types. Since HDDV behavior is often characterized by cross-country travel, much of
the fuel consumption of these vehicles is accrued outside the county of registration. This is accounted
for in the methodology used to calculate the HDDV VMT as discussed in the previous sections.
The VMT estimates used to calculate fuel consumption are estimated in one of two ways
depending on the availability of county-level measured VMT data. If this is available, the VMT is
normalized based on the State DOT VMT as discussed in subsection "Normalized Estimates of County
VMT by Vehicle Type with State DOT VMT." Otherwise, VMT is normalized based on the appropriate
State VMT reported in Highway Statistics31, as discussed in subsection "Normalized Estimates of
County VMT by Vehicle Type without State DOT VMT." A miles per gallon value is applied to the
normalized VMT by vehicle type and this value is used to distribute total State highway diesel
consumption to counties.31
Total State highway diesel consumption and fuel efficiency estimates are found in Federal
Highway Administration Highway Statistics.31
4-11
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County diesel consumption by highway vehicle type T (CHDCT) (1000 gallons) is estimated by
the following equation:
CHDCT=
NCVMTT • MPGT
n=1 /n=6
(NCVM Tmin - MPGmJ
SHD
where: CHOCT = County diesel consumption by highway vehicle type T
NCVMTT = Normalized estimate of county-level VMT for diesel vehicles
(see "County VMT by Vehicle Type")
MPGT = Average mpg of fuel consumed31
SHD = Published total State highway diesel consumption31
T 6 for LDDV
7 for LDDT
8 for HDDV
Motorcycle Registration Estimates by Vehicle Age
An estimate of motorcycle registrations by county by age (VR5>) is estimated with the following
equation:
= SMH • - MRM
where: VR5> = Estimated county motorcycle registrations by age
SMH - State motorcycle population for highway use [from Motorcycle
Statistical Annual35]
CP = Current county population
SP = Current State population
MRMA = Motorcycle registration mix by age [from MOBILE28 model]
Emission Factors
Emission factors for highway vehicles are computed using EPA's MOBILE28 model. The model
is run with the following standard inputs to compute county-specific emission factors for each vehicle
class:
1. County-specific vehicle registrations by model year and vehicle class, as obtained from
R. L. Polk Company;34
2. MOBILE28 default values for mileage accumulation distributions;
3. No use of special correction factors for air conditioning, vehicle load, trailer towing, or
humidity;
4. VOC emission factors computed on a non-methane basis;
4-12
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5. No modification of MOBILE standard trips/day or miles/day data;
6. MOBILE default values for tampering rates (no credits for anti-tampering programs are
considered).
For each county, MOBILE scenario records are input to specify:
1. The location of the county in a low altitude or high altitude region. (For California, the
model is run for "low attitude" with modified basic exhaust emission rates by model year
to correspond to California emission standards. These data are provided by the
California Air Resources Board.)36
2. Average vehicle speeds of 55, 45, and 19.6 mph, corresponding to the road categories
for which VMT have been estimated for each county. (For 19.6 mph roads, standard
values of 20.6 percent of VMT accumulated in cold-start mode and 27.3 percent of
VMT accumulated in hot-start mode are used. For 55 mph roads, the percent of VMT
accumulated in both cold- and hot-start modes are assumed to be zero. For 45 mph
roads, percentages for the most current year will be calculated when data become
available, by assuming the standard values for 19.6 mph roads for local rural roads and
zero for rural collector roads.)
3. An annual average ambient temperature typical of a weather station near the centroid
of a State. (The same temperature is used for all counties in a State.)
4. The impact of county inspection/maintenance (I/M) programs. (For counties where I/M
programs are in effect, data to estimate the impact of such programs are supplied by
the EPA Office of Mobile Sources.28)
OFF-HIGHWAY SOURCES
Emissions from off-highway vehicles are generated by activities of gasoline and diesel vehicles
which do not utilize road systems. Vehicles contributing to off-highway emissions are divided into five
general categories: farm equipment, construction equipment, industrial equipment, lawn and garden
equipment, and recreational vehicles which include off-highway motorcycles and snowmobiles. While
gasoline is consumed by all five categories, diesel fuel is utilized only by farm equipment, construction
equipment, and industrial equipment.
In general, consumption is estimated by one of the following methods:
1. Apportionment of national fuel consumption to counties on the basis of employment,
population, etc.
2. Calculation of county or State totals by applying fuel consumption rates to average
usage figures and equipment populations.
Consumption estimation methodologies are described below for each category by fuel type.
Farm Equipment
State consumption of gasoline and diesel fuel by farm equipment is apportioned to individual
counties based on county tractor population data. To estimate State fuel consumption by farm
4-13
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equipment, consumption values are calculated separately for each of five subcategories: farm tractors,
combines, motorized balers, forage harvesters, and general purpose large utility engines. Consumption
by fuel type is calculated using subcategory State population, average annual usage (hours per year),
and average hourly consumption by fuel type per unit (gallons per hour).11-35 For diesel fuel, the sum of
the estimated fuel use for all subcategories is normalized to agree with published State totals for
agricultural diesel fuel use found in DOE Fuel Oil and Kerosene Sales.12 Total State consumption is
then allocated to the county level according to the ratio of county tractor population to State tractor
population.
Average annual usage and average hourly consumption are extracted from Exhaust Emissions
from Uncontrolled Vehicles and Related Equipment Using Internal Combustion Engines.37 With the
exception of general purpose large utility engines, State and county equipment populations are
obtained from Census of Agriculture-State and County Data.36 Large utility engine populations are
estimated in an algorithm which uses State tractor population and the number of irrigated and
non-irrigated farms obtained from Census of Agriculture-Summary and State Data.39
For all gasoline-consuming categories, it is assumed that 91.8 percent of total hydrocarbon is
reactive VOC. This fraction is based on the VOC Species Data Manual. Profile 90-6021D.40 For all
diesel consuming categories, a value of 95.2 percent of total hydrocarbon is assumed to be reactive
VOC based on Profile 90-7021.
Off-Highway Gasoline: Farm Equipment Equations -
A normalized estimate of County Gasoline Consumption by Farm Equipment (NCFG) (1000
gallons) is computed as follows:
NCFG = ECFG
SGF
c
E
n=1
where: NCFG
ECFG
SGF
c
Normalized estimated county gasoline consumption by farm
equipment
Estimated county gasoline consumption by farm equipment
(computed below)
Reported State agricultural gasoline consumption
Number of counties in the State
£ fn'CEn'An-FRn
ECFG =
1000
where: f
k
Fraction of farm equipment that is powered by gasoline
Equipment type
(1 for tractors
2 for combines
3 for balers
4-14
-------
4 for large general purpose engines)
CE = County population of farm equipment
A = Average annual usage (hours/year) of farm equipment
FR = Average consumption (gallons/hour) of gasoline per unit of
equipment
The formula used to compute county population of large general purpose engines (CE4) is:
FC-IFC\
CE. = 0.03 - TC
U 0.05 • TC •
FC )
where: TC = County tractor population
IFC = Number of farms in State in irrigated areas
FC = Number of farms in State with market value of crops sold >
$2500
Off-Highway Diesel: Farm Equipment Equations -
An estimate of County Diesel Consumption by Farm Equipment (ECFD) (in 1000 gallons) is
calculated as follows:
ECFD = — • SDF
TS
where: ECFD = Estimated county diesel consumption by farm equipment
TC = County tractor population
TS = State tractor population
SDF = Reported State farm use of diesel
Off-Highway: Farm Equipment Emission Factors -
Emission factors for gasoline and diesel farm tractors and other farm equipment are obtained
separately from AP-42, Table II-6-2.8 Large utility equipment emission factors are also taken from
AP-42.Table3.1-2.
Construction Equipment
The method used to determine consumption of gasoline and diesel fuel by construction
equipment distributes State gasoline and diesel fuel consumption to the county level based on
employment. For the purposes of this algorithm, total non-building construction employment is the sum
of the employment of heavy construction (SIC category 16) and special trade (SIC category 17)
industries. County consumption of fuel is then allocated from State construction consumption based on
the ratio of county employment of heavy construction (SIC category 16) and special trade (SIC category
17) industries to State employment for those same SIC categories.
4-15
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Estimates of State gasoline consumption are obtained from the DOT publication Highway
Statistics.31 For diesel fuel, published State totals are reported by DOE in the Fuel Oil and Kerosene
Sales report.12 Annual employment data are extracted from the Census Bureau's County Business
Patterns.22
Off-Highway Gasoline: Construction Equipment Equations -
An estimate of County Gasoline Consumption by Construction Equipment (CGCE) (in 1000
gallons) is calculated as follows:
CGCE =
CCE
SCE
SCG
where: CGCE
CCE
SCE
SCG
Estimated county gasoline consumption by construction
equipment
County employment in heavy construction
State employment in heavy construction
Reported State construction use of gasoline
Off-Highway Diesel: Construction Equipment Equations -
An estimate of County Diesel Consumption by Construction Equipment (ECCD) (in 1000
gallons) is calculated as follows:
ECCD =
SCE
SCO
where: ECCD
CCE
SCE
SCO
Estimated county diesel consumption by construction
equipment
County employment in heavy construction
State employment in heavy construction
Reported State construction use of diesel
Off-Highway: Construction Equipment Emission Factors -
Emission factors from AP-428 are weighted separately for diesel fuel (Table 11-7.1) and gasoline
(Table II-7.2) equipment using consumption data from the Procedures Document. Table 3.5-1.41
Industrial Equipment
The methodology involves apportioning national industrial fuel consumption according to relative
differences in labor productivity of three industries.11 The algorithm compares combined county
employment to the combined State employment of manufacturing (SIC categories 20 through 39),
mining (SIC 10 through 14), and wholesale trade industries (SIC 50).
Estimates of State gasoline consumption due to industrial equipment are obtained from DOT'S
Highway Statistics31, and estimates of State diesel consumption due to industrial equipment are
obtained from DOE's Fuel Oil and Kerosene Sales report.12 Total employment in manufacturing,
4-16
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mining, and wholesale trade is the sum ot figures reported in Bureau of Census County Business
Patterns22 for SIC categories 20 through 39, 10 through 14, and 50, respectively.
Off-Highway Gasoline: Industrial/Commercial Equipment Equations -
An estimate of County Gasoline Consumption by Industrial/Commercial Equipment (CGIC) (in
1000 gallons) is calculated as follows:
CGIC - SICG • (CMF + CME + CWE)
(SMF + SME + SWE)
where: CGIC = Estimated county gasoline consumption by
industrial/commercial equipment
SICG = State gasoline consumption due to industrial/commercial
equipment
CMF = Total county employment in manufacturing (SIC 20 through 39)
CME = Total county employment in mining (SIC 10 through 14)
CWE = Total county employment in wholesale trade (SIC 50)
SMF = Total State employment in manufacturing (SIC 20 through 39)
SME = Total State employment in mining (SIC 10 through 14)
SWE = Total State employment in wholesale trade (SIC 50)
Off-Highway Diesel: Industrial/Commercial Equipment Equations -
An estimate of County Diesel Consumption by Industrial/Commercial Equipment (ECDIC) (in
1000 gallons) is calculated as follows:
ECDIC = SICD • (CMF * CME * CWE>
(SMF + SME + SWE)
where: ECDIC = Estimated county diesel consumption by industrial/commercial
equipment
SICD = State diesel consumption due to industrial/commercial
equipment - (computed betow)
CMF = Total county employment in manufacturing (SIC 20 through 39)
CME = Total county employment in mining (SIC 10 through 14)
CWE = Total county employment in wholesale trade (SIC 50)
SMF = Total State employment in manufacturing (SIC 20 through 39)
SME = Total State employment in mining (SIC 10 through 14)
SWE = Total State employment in wholesale trade (SIC 50)
SICD = OFFHIGHWAY DIESEL: OTHER + MILITARY USE: DIESEL
4-17
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Off-Highway: Industrial/Commercial Equipment Emission Factors -
Emission factors for industrial equipment are taken directly from AP-42, Table 3.1-2.8
Lawn and Garden Equipment
The original methodology involves allocation of national consumption of gasoline by lawn and
garden equipment to individual counties.37 Regression analyses yielded an algorithm in which county
apportionment is based on the number of single-unit dwelling structures, the number of freeze-free days
(i.e., minimum average temperature higher than 32°F), the fraction of national snow zone population in
the county (all areas with an annual snowfall greater than 30 inches), snowthrower fuel consumption
rate, average snow removal rate, and county snowfall.
Annual weather data including freeze-free days and county snowfall are reported monthly for
selected representative weather stations in each county in NOAA's Climatological Data.6 The number
of dwelling units in single structures is available in the Census Bureau's decennial Census of Housing.4
Current county population is available from the Bureau of Census Current Population Reports.15
National gasoline consumption is estimated by using calculations based on Exhaust Emissions from
Uncontrolled Vehicles and Related Equipment Using Internal Combustion Engines.37
Off-Highway Gasoline: Lawn & Garden Equipment Equations -
A normalized estimate of the County Gasoline Consumption by Lawn and Garden Equipment
(NCGLG) (in 1000 gallons) is computed as follows:
NCGLG = ECGLG
TNLG
£ ECGLGn
where: NCGLG
ECGLG
TNLG
x
Normalized estimated county gasoline consumption by lawn
and garden equipment
Estimated county gasoline consumption by lawn and garden
equipment (computed below)
Total national gasoline consumption by lawn and garden
equipment (computed below)
Number of counties in nation
TNLG = NLG + NSG
where: NLG
NSG
National gasoline consumption by lawn and garden equipment
other than snowthrowers (computed below)
National gasoline consumption by snowthrowers (computed
below)
4-18
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The formula used to compute (NLG) is:
NLG = 553 -10*Gallons • ———
58,255,000
where: NSU = number of dwelling units in single unit structures
The formula used to compute (NSG) is:
NSG = NLG - 0.05
The formula used to compute (ECGLG) is:
ECGLG = CNLG + CNSG
where: CNLG = Estimated county gasoline consumption by lawn and garden
equipment other than snowthrowers
CNSG = Estimated county gasoline consumption by snowthrowers
The formula used to compute (CNLG) is:
CSU CFF-3174
CNLG = NLG
NSU NFF
where: CSU = Number of dwelling units in single unit structures in county
NSU - Number of dwelling units in single unit structures in nation
CFF = Number of freeze-free days in county
NFF = Number of freeze-free days in nation
The formula used to compute (CNSG) is:
where: CP = Current county population
SZP = Snow-zone population
CS «= County snowfall
SZS = Snow-zone snowfall
K = 0 if CS S 30 inches
1 if CS > 30 inches
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Off-Highway Gasoline: Lawn and Garden Equipment Emission Factors -
Emission factors for gasoline powered lawn and garden equipment are taken directly from the
small general utility engines section of AP-42, Table 11-5-1."
Recreational Vehicles
Emissions from recreational vehicles are generated by activities of gasoline vehicles which do
not generally utilize road systems. Recreational vehicles contributing to off-highway emissions are
currently divided into two categories: motorcycles and snowmobiles. The following discussions
describe how AMS develops emission estimates for the individual components of this category and
combines the results to obtain a total for the category of recreational vehicles.
Off-Highway Motorcycles -
The original algorithm estimated county level gasoline consumption based on population, State
motorcycle registrations, average annual usage (miles per year), and average fuel consumption rate
(gallons per mile).37 A later refinement to this method involved separating off-road and combined use
motorcycles and weighting the distribution of the two types according to regional variations for
allocation.3
State motorcycle vehicle registration data, national usage rate, factors for the two types of
motorcycles, and national fuel consumption rate for both off-road and combination use motorcycles are
available from FHWA Highway Statistics31 and the Motorcycle Statistical Annual.35 Current county
population statistics are obtained from the Bureau of Census Current Population Reports.15
Snowmobiles -
County consumption of gasoline by snowmobiles is derived from the national snowmobile
gasoline consumption total allocated on the basis of county snowmobile population. To estimate county
level snowmobile population, a set of regression formulations is used to relate the percent of State
snowmobiles used in the county to population and snowfall.37 To reflect the impact of population
density on snowmobile usage, different algorithms are used to calculate usage in counties with
population densities greater and less than 1000 per square mile. A factor reflecting the ratio of average
county snowfall to snowfall received in the center of the State is included in these algorithms due to its
significance in the regression analyses.
State snowmobile registration data are available by contacting the International Snowmobile
Association.42 Snowfall statistics for each county and the county centroid for each State are compiled
by NOAA.6 County population statistics are recorded in the Bureau of Census Current Population
Reports.15
Off-Highway Gasoline: Recreational Vehicle Equations -
An estimate of the County Gasoline Consumption by Recreational Vehicles (CGRV) (1000
gallons) is computed as follows:
CGRV = CGM + CGSM
where: CGRV = Estimated county gasoline consumption by recreational vehicles
4-20
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CGM = Estimated county gasoline consumption due to motorcycles
(computed below)
CGSM = Estimated county gasoline consumption due to snowmobiles
(computed below)
The formula used to compute (CGM) is:
. SM .
MFR
1000
where: CP = Current county population
SP = Current State population
SM = State motorcycle population
f, = Fraction of motorcycles that are off-road (computed below)
u, = Average usage (miles/year) of off-road motorcycles
f2 = Fraction of motorcycles that are combination (computed below)
uz = Average usage (miles/year) of combination motorcycles
MFR = Motorcycle fuel consumption rate (miles/gallon)
The formula used to compute (f,) is:
sr
E ORM.
f _
'
'1
(ORMn + CBMn + HWMJ
where: sr = Number of States in census region
ORM = State population of off-road motorcycles
CBM = State population of combination motorcycles
HWM = State population of highway motorcycles
The formula used to compute (fz) is:
E CBMn
4 ~
sr
(ORMn + CBMn + HWMJ
where: sr = Number of States in census region
CBM = State population of combination motorcycles
4-21
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ORM = State population of off-road motorcycles
HWM = State population of highway motorcycles
The formula used to compute (CGSM) is:
CGSM = NGS - ^-
NSM
where: NGS = National gasoline consumption by snowmobiles (computed
below)
CSM = County snowmobile population (computed below)
NSM = National snowmobile population
The formula used to compute (NGS) is:
NGS = 83-106 Gallons • NSM
1,715,000
where: NSM = National snowmobile population
The formula used to compute (CSM) is:
CSM = — — - SSM
c=1
where: f = Fraction of State's snowmobiles that are located in the county
(computed below)
n = Number of counties in State
SSM = State snowmobile population
The formula used to compute the fraction of the State's snowmobiles that are located in the
county (f) is determined by the county's population density and the amount of snowfall the county
receives in a given year:
For counties with population densities of less than 1000 per square mile, the formula is:
• ('- I
o.0321 • -. - 0.0234
CCS
where: CP = Current county population
SP -= Current State population
CS « County snowfall
4-22
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CCS = Snowfall in State's centroid county
For counties with population densities of more than 1000 per square mile, the formula is:
f = X - - + [1.5 - (0.0005 • CPD)]
where: X 0 if CPD > 3,000
X 1 if 3,000 Z CPD £ 1,000
CP = Current county population
SP = Current State population
CPD = County population density
Off-Highway Motorcycle Emission Factors -
Emission factors for gasoline motorcycles are determined utilizing the MOBILE28 program with
the following conditions:
1. County Altitude -- Low
2. Vehicle Speed --19.6 mph
3. Ambient Temp. -- 57°F
4. Hot Start/Cold Start Percentage -- Zero
5. All other variables - Default values
Resulting emission factors in grams per VMT are converted to pounds per 1000 gallons using a
unit conversion factor of 20.8.
Snowmobile Emission Factors -
Emission factors for gasoline powered snowmobiles are taken from AP-42, Table 11-8-1.8
AIRCRAFT
Emissions estimates for aircraft are divided into three categories: commercial aircraft, military
aircraft, and civil aircraft. Activity levels and emission factors, measured relative to units of aircraft
landing and takeoff cycles (LTOs) by county, are multiplied by emission factors to obtain emissions
estimates.
Activity level is measured by LTOs using either operation records from county airports or
aircraft registration data, depending on the location of Federal Aviation Administration (FAA) airports.
For the purpose of these calculations, an operation, as defined by the FAA, constitutes either a takeoff
or landing.
Weighted average emission factors are computed for each type of aircraft within each aviation
category. In some categories, flying hours are used as a unit of measure assuming that the number of
flying hours is proportional to the number of LTOs. Emission factors are then combined using aircraft
type population data from Jane's43 and FAA Aviation Forecasts44 to form one factor for each pollutant.
4-23
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Commercial Aircraft
For counties with FAA regulated airports LTOs are derived separately from reported operations
for air carrier and air taxi categories. Locations of FAA regulated airports are obtained from the FAA
Air Traffic Activity.45
Air Carrier -
County estimates of air carrier LTOs (LTO^) are calculated using the following formula:
LTOM = 0.5 •
where: LTOAC = Estimated county number of air carrier LTOs
OAC = Total operations in county for air carrier
Emission Factors -
Commercial service aircraft emission factors from AP-42,Table 11-1-98 are updated and
weighted from the previous year's data on LTOs from the Procedures Document. Table 3.2.4.41 and the
FAA's Census of U.S. Civil Aircraft.46 The number of operations in the update year is estimated using
the number of aircraft in service for each of the following plane types: BAC 111, Boeing-707, Boeing
727, Boeing 737, Boeing 747, L1011, DCS, DC9, and DC10. The resultant value is compared with the
reported update year value obtained from FAA Air Traffic Activity.45 The weighting factors are applied
to the emission factors to produce an average for all plane types.
Air Taxi -
County estimates of air taxi LTOs (LTOAT) are calculated using the following formula:
LTOAT = 0.5 • 0AT
where: LTOAT = County estimates of air taxi LTOs
OAT * Total operations in county for air taxi
Emission Factors -
Air taxi emission factors are weighted averages for emission factors for turbojets, turboprops,
and piston planes taken from AP-42, Table 11-1 -9." Weighting is based on the number of aircraft from
FAA's Census of U.S. Civil Aircraft.48
Military Aircraft
For counties with FAA regulated airports, LTOs are derived from reported operations for the
military aircraft category. In addition, an accounting must be made of military aircraft operations at
non-FAA regulated airports. These data, previously published in the FAA's Military Air Traffic Activity47
report, are still available from the FAA although not in a published report format.
4-24
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Military -
County estimates of military LTOs (LTOM) are calculated using the following formula:
LTOU = 0.5 • Ou
where: LTOM = County estimates of military LTOs
OM = Total operations in county for military
Emission Factors -
Emission factors for each aircraft type are taken from AP- 42, Table 11-1-10.8 Initial emission
factors are averaged and weighted by usage and population data. The number of flying hours for
single-engine piston planes, multi-engine piston planes, turboprops, turbojets, rotocraft piston planes,
and rotocraft turbine planes is obtained from FAA Aviation Forecasts.44 Average emission factors are
weighted by aircraft population data found in Jane's43 and FAA Aviation Forecasts.44
Civilian Aircraft
For counties with no FAA regulated airports or military airports, all operations are assumed to
involve civil aircraft only. The number of LTOs are derived using county aircraft registration data. It is
assumed each aircraft performs 250 LTOs per year.
The number of active civil aircraft registrations is found in the FAA's Census of U.S. Civil
Aircraft.46
Civil -
County estimates of civil LTOs (LTOCT) are calculated using the following formula:
= 0.5 •
where: LTO^ = County estimates of civil LTOs
OCR = Total operations in county for civil aircraft
For counties with no FAA-regulated airports or military airports, all operations in the county are
assumed to involve civil aircraft only. The number of LTOs for civil aircraft is calculated using county
aircraft registrations. The equation is the following:
LTOCR = 250 • N
where: N = Number of aircraft registered in county
4-25
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Emission Factors -
Emission factors are determined by the same procedure as in Military Aircraft.
Unpaved Airstrips
Unpaved airstrip emissions are affected by the same primary factors as unpaved roads.
Fugitive emissions from unpaved airstrip use are measured by annual LTO cycles on unpaved airstrips
in each county. The activity level estimate derived for each county in the AMS is multiplied by an
adjusted emission factor to obtain a paniculate emissions estimate.
A methodology to measure the activity level by LTO cycles at unpaved airstrips within the
county is determined by identifying all airports which have airstrips made of dirt, sand, gravel, or gravel
pavement, excluding airports with no based aircraft, airports no longer in operation, heliports, and
seaplane bases. The number of aircraft based in each airport is tallied for each county and then
multiplied by 250. Local FAA officials estimated the typical number of LTOs of a based aircraft at small
airport facilities is 250 per year.48
Emission Factors -
The paniculate emission factor was obtained from Emissions Inventory of Agricultural Tilling.
Unpaved Roads and Airstrips, and Construction Sites.48 For the purposes of these calculations,
average LTO speed is estimated at 40 miles per hour, the length of the runway to complete one LTO is
1 mile, and the wind-erosion multiplier is 2. Surface texture is determined for each State based on the
number and type of non-surfaced airstrips and average soil silt content for each county.
MARINE VESSELS
Marine vessel categories for which emissions estimates are discussed include distillate oil
vessels, residual oil vessels, and gasoline vessels. Emissions from coal vessels have not been
estimated because emissions from this source are considered negligible compared to other area
sources. Consumption methodologies and emission factor derivation are presented below for each
category. The methods for generating activity level estimates are discussed, and final estimates are
presented in gallons of fuel consumed.
Diesel (Distillate) Oil Vessels
Emissions are estimated for marine vessels which use distillate oil (diesel fuel). This category
includes large cargo and passenger ships, oil tankers, tugboats, and other steamships and motorships
that are known to consume distillate oil. The activity level, measured in thousands of gallons, is
multiplied by emission factors to obtain emissions estimates. The methodology requires the updating of
the most recent year's estimate with fuel data obtained from "Fuel Use by Vessels Bunkering" in the
Fuel Oil and Kerosene Sales report12 excluding fuel used by ships outside the U.S. continental limits.
The original methodology estimated county level consumption based on number, type, and size
of ship, and time spent in port and underway. Consumption by vessels at ports for which consumption
data were available was assigned to the port county. The remaining fuel consumption was distributed
to ports and waterways according to tonnage handled. Information on fuel sales to vessels was taken
from Fuel Oil and Kerosene Sales12 and ship characteristics were obtained from Waterborne Commerce
of the United States.49
4-26
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Diesel (Distillate) Oil Vessel Equations -
County consumption of diesel fuel by marine vessels (MVD) (1000 gallons) is computed using
the formula:
MVD = PIPD -
£ CMVDn
where: MVD = County consumption of diesel fuel by marine vessels
PIPD = Percent of diesel fuel consumed within the Continental U.S.
CMVD = County consumption of diesel fuel by marine vessels on AIRS
AMS statistical file
c = Number of counties in State
SMD = State deliveries of diesel fuel for use by marine vessels
Diesel (Distillate) Oil Vessel Emission Factors -
Emission factors used for all pollutants except for VOC are the weighted averages of emission
factors for commercial diesel motorships and steamships. Reactive VOC is determined to be a
percentage of total VOC as taken from Profile 9-07-021 of the VOC Species Data Manual.40 Each
emission factor is derived in a series of calculations using emission factor data presented in AP-42,
Tables 11-3-1, II-3-2 and II-3-4.8 For the purposes of these calculations the following assumptions are
made:
1. Commercial vessel population is comprised of 75 percent motorships and 25 percent
steamships.
2. Commercial steamships spend 80 percent of the time hotelling and 20 percent
underway.
3. Diesel steamships spend 20 percent of the time under auxiliary power and 80 percent
underway.
Efforts are made to exclude operations conducted outside the Continental U.S.
Residual Oil Vessels
Emissions are estimated for marine vessels which use residual oil. This category includes
large cargo and passenger ships, oil tankers, tugboats, and all other steamships and motorships that
are known to consume residual oil. The activity level, measured in thousands of gallons, is multiplied
by emission factors to obtain emissions estimates.
The original methodology estimated county level residual oil consumption based on 1975 data
concerning the number, type, and size of ship, and time spent in port and underway. Consumption by
vessels at ports for which consumption data were available was assigned to the port county. The
remaining fuel consumption was distributed to ports and waterways according to tonnage handled. The
original methodology was based on fuel sales to vessels from Fuel Oil and Kerosene Sales12, and ship
characteristics from Waterbome Commerce of the United States.49
4-27
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The methodology currently used to determine the consumption of residual oil by marine vessels
requires the updating of the most recent year's estimate with fuel data obtained from "Fuel Use by
Vessels Bunkering" in the Fuel Oil and Kerosene Sales report12 excluding fuel used by ships outside
the U.S. continental limits.
Residual Oil Vessel Equations -
County consumption of residual fuel by marine vessels (MVR) (1000 gallons) is computed using
the formula:
MVR = PIPR - c - SMR
E OMVRn
where: MVR = County consumption of residual fuel by marine vessels
PIPR = Percent of residual fuel consumed within the Continental U.S.
CMVR = County consumption of residual fuel by marine vessels on AIRS
AMS statistical file
SMR = State deliveries of residual fuel for use by marine vessels
c = Number of counties in State
Residual Oil Vessel Emission Factors -
Emission factors used for all pollutants except for VOC are the weighted average of the
emission factors for commercial residual oil motorships and steamships. Reactive VOC is determined
as a percentage of the total VOC as taken from Profile 1-01-004 of the VOC Species Data Manual.40
Each emission factor is determined with AP-42, Tables 11-3-1 and II-3-28 by the same procedure as in
Distillate Oil Vessels using assumptions 1 and 2.
Gasoline Vessels
County marine consumption of gasoline is calculated using an algorithm that accounts
separately for inboard and outboard motor use.11'35 Using this method, State gasoline consumption
figures are derived from State boat registration (inboard and outboard), and average fuel consumption
for each boat type (gallons per hour). State consumption is then allocated to counties according to
county inland water area, coastline, and the number of warm months which are suitable for recreational
boating activities. The number of warm months is assumed to be the number of months during which
the monthly normal temperatures exceed 45°F for counties north of 43° latitude, 48°F for counties
between 37° and 43° latitude, and 55°F for counties south of 37° latitude. Coastline is converted to
inland water area using a factor which is the ratio of coastline and open water boating density to inland
water area and inland boating density.
Boat registration data are obtained from National Marine Manufacturing Association's Boating
Registration Statistics.50 Average fuel consumption for inboard and outboard motors is assumed to be
3.0 and 1.5 gallons per hour, respectively. County inland water and coastline areas are available in
Bureau of Census Area Measurement Report: U.S. Summary.51 Weather data are found in NOAA's
Climatological Data.6
4-28
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Gasoline Vessel Equations -
A normalized estimate of gasoline consumption by Marine Vessels (NMVG) (1000 gallons) is
computed using the formula:
NMVG = MVG
SMVG
n=1
where: NMVG
MVG
SMVG
c
Normalized estimate of gasoline consumption by marine
vessels
Estimate of county gasoline consumption by marine vessels
(computed below)
Reported State consumption of gasoline use by marine vessels
Number of counties in State
The formula used to compute (MVG) is:
°IW + (/**°^ 10 '
MVG =
S/W + (frSQ
(SIB • IFC + SOB - OFC)
1000
where: CIW
f.
CC
SIW
SC
CWM
SIB
IFC
SOB
OFC
County inland water area
State factor for converting coastline to inland water area
County coastline
State inland water area
State coastline
Number of "warm" months in county
State inboard boat population
Average gasoline consumption rate (gallons/hour) of inboard
boats
State outboard boat population
Average gasoline consumption rate (gallons/hour) of outboard
boats
Gasoline Vessel Emission Factors -
Average weighted emission factors are based on the inboard and outboard motorboat
registrations. Weighting accounts for higher fuel consumption per hour operation by inboard motors.
For VOC, it is assumed that the reactive fraction is 0.91 72 based on VOC Species Data Manual. Profile
9-06-021 B.40
RAILROAD LOCOMOTIVES
This category includes fuel utilized by railroad locomotives and fuel used by railroad stations
and workshops for space heating. The latter fuel consumption has been included primarily because it
is difficult to separate from total railroad fuel use and is considered insignificant compared to locomotive
4-29
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consumption. The primary fuel consumed by railroad locomotives is distillate oil (diesel fuel). The
activity level, measured in thousands of gallons, is multiplied by emission factors to produce emissions
estimates.
The methodology used to estimate distillate oil consumption involves the allocation of published
State consumption of distillate oil by railroad locomotives to the county level on the basis of current
population distribution.
Data on the use of distillate oil by railroads for each State are obtained from DOE's Fuel Oil
and Kerosene Sales report.12 Population statistics are available from the Current Population Reports.15
Railroad Locomotive Equation
County consumption of diesel fuel by railroads (RRD) (1000 gallons) is computed using the
formula:
CP
RRD= 3RD •
SP
where: RRD = County consumption of diesel fuel by railroads
SRD = State fuel oil deliveries to railroads
CP = Current county population
SP = Current State population
Railroad Locomotive Emission Factors
The emission factors for railroad use are taken from AP- 42, Table II-2-2.8
GASOLINE MARKETING
This source category covers evaporative losses of volatile organic compounds from gasoline
marketing operations such as filling losses from loading underground storage tanks at service stations,
and spillage and filling losses from filling automobile tanks. Gasoline evaporative losses at refineries or
bulk distribution terminals are not included. Emissions from refineries are assumed to be accounted for
in point source categories.
The activity level for this category, measured by retail gas sales in thousands of gallons, is
multiplied by emission factors to generate emissions.
Retail sales of gasoline include all sales of gasoline for highway use, aviation use, and for use
by the construction equipment, industrial equipment, and farm equipment off-highway subcategories.
Sales to the above user categories are estimated separately and summed to generate total county
sales.
State retail sales of gasoline for highway and marine use are allocated to each county
according to the county's proportion of the Statewide gross dollar receipts from gasoline service
stations. Published State aviation retail sales of gasoline are allocated to the county according to the
total LTO cycles in the county for each of the military, civilian, and commercial aircraft categories.
4-30
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County retail sales of gasoline for off-highway sources are assumed to be the same as
consumption derived in the activity levels section of Farm Equipment, Construction Equipment, and
Industrial Equipment in Off-highway sources.11
Retail sales of gasoline for each category are obtained from the Census Bureau's quinquennial
Census of Retail Trade.52
Retail Gasoline Sales: Gasoline Marketing - Stage I. Stage II, and Splllaae Equations
formula:
A county estimate of Retail Gasoline Sales (CGS) (1000 gallons) is computed using the
CGS = SHG
—— + NCFG + CGCE + CGIC + SAG • -^
SG/? s/.r
where: CGS
SHG
CGR
SGR
NCFG
CGCE
CGIC
SAG
CLT
SLT
County estimate of retail gasoline sales
State retail sales of gasoline for highway and marine use
(computed below)
Gross receipts of gasoline service stations in county
Gross receipts of gasoline service stations in State
Normalized estimate of county gasoline consumption by farm
equipment (See Off-Highway Gasoline: Farm Equipment
Equations)
Estimate of county gasoline consumption by construction
equipment (See Off-Highway Gasoline: Construction
Equipment Equations)
Estimate of county gasoline consumption by industrial and
commercial equipment (See Off-Highway Gasoline: Industrial
and Commercial Equipment Equations)
State aviation gasoline consumption
Total LTO cycles in county for military, civil, and commercial
aircraft (see Aircraft Category Calculations)
Total LTO cycles in State for aircraft categories
The formula used to compute (CLT) is:
CLT = LTOAC + LTOAT + LTOM + LTOCR
The formula used to compute (SLT) is:
SLT = CLT
n
where: c
number of counties in the State
4-31
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The formula used to compute (SHG) is:
SHG = TSO + TSH - SGC + SGI + SGF + SAG
where: TSO = Reported total State off-highway consumption
TSH = Reported total State highway gasoline consumption
SGC = Reported State gasoline consumption by construction
equipment
SGI = Reported State industrial/commercial gasoline consumption
SGF = Reported State agricultural gasoline consumption
SAG = Reported State aviation gasoline consumption
Retail Gasoline Sales: Gasoline Marketing - Stage I. Stage II. and Spillage Emission Factors
Emission factors are obtained from AP-42, Table 4.4-7.8
UNPAVED ROADS
Vehicle traffic over unpaved roads, parking areas, and recreational areas generates fugitive
dust emissions which are estimated in AMS. Primary factors which affect the amount of dust generated
are vehicle speed, surface type, wind speed, surface moisture, and type of vehicle. Methodologies for
the estimation of activity level measured in VMT and for emission factor derivation are described below.
The methodology to determine county VMT on unpaved roads is based on regression analysis
of data collected for VMT per county and mileage of unpaved roads per county. County road mileages
for this study were obtained from State transportation or highway departments. VMT was found to be
dependent on the county population and mileage of unpaved roads in the county.
County population statistics are taken from Current Population Reports.15 State road mileage
for surface types A through E are published annually by FHWA's Highway Statistics.31
Unpaved Roads: VMT Equations
County estimates of unpaved road VMT (UPR) are computed using the following equation:
CUPM
UPR = CUPR
SUPM
where: UPR «= County estimate of unpaved road VMT
CUPR - County estimate of unpaved road VMT on AIRS AMS statistical
file
CUPM - Reported unpaved road miles by State in current year
SUPM - Reported unpaved road miles by State in previous year
4-32
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If CUPM is not available, then the following equation is used:
CRUPM
UPR = CUPR
RUPM
where: CRUPM = Reported unpaved road miles by Census Region in current
year
RUPM = Reported unpaved road miles by Census Region in previous
year
If CRUPM is not available, then the following equation is used:
CNUPM
UPR = CUPR
NUPM
where: CNUPM = Reported unpaved road miles for the nation in current year
NUPM = Reported unpaved road miles for the nation in previous year
Unpaved Roads: VMT Emission Factors
Emission factors are computed using the equation in AP-42, section 11.2.1.8 The aerodynamic
particle size multiplier corresponding to the inclusion of particles less than or equal to 30 micrometers
was used. Average vehicle speed is assumed to be 40 miles per hour. Road surface material, silt
content, and the number of days with precipitation are taken from Emissions Inventory of Agricultural
Tilling. Unpaved Roads and Airstrips, and Construction Sites.4* Mean vehicle weight for four-wheeled
vehicles is assumed to be 3.69 tons.
4-33
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SECTION 5
INDUSTRIAL PROCESSES
Industrial processes are very properly considered as point sources in most emission inventories
and in the recent past have not been considered to be significant contributors to area source emissions.
However, there may be many industrial processes that are too small to be considered point sources,
but collectively may contribute substantially to the overall total. At the present time, no methodologies
are available to estimate activity levels on a county basis.
CONSTRUCTION
Road and building construction activities generate paniculate emissions. Principal activities in
construction which cause dust emissions are land clearing, excavation, and vehicle traffic around the
construction site. Variables known to affect emissions are soil type, moisture, wind speed, and type of
on-site operations. At present, no methodology is available to estimate activity level at the county level.
However, emission factors are available from AP-42 (Section 11.2.4).8
5-1
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SECTION 6
SOLVENT UTILIZATION
The following discussion documents the estimation procedures for evaporative losses of VOC
from solvent usage by area sources. Organic solvent usage is divided into seven major categories:
surface coating operations, decreasing, dry cleaning, graphic arts, rubber and plastic manufacturing,
miscellaneous industrial operations, and miscellaneous nonindustrial operations. Surface coating is
further divided into the following subcategories: architectural coatings, auto refinishing, textile products
flatwood products, wood furniture, metal furniture, paper, plastic products, cans, metal coils,
miscellaneous finished metals, electrical, large appliances, magnet wire, motor vehicles, aircraft,
marine, railroad, and miscellaneous manufacturing operations. In each category, usage of specific
solvents is identified and enumerated to compute total solvent usage in short tons per year.
The methodology for allocating organic solvent consumption by county consists of apportioning
national consumption of 20 primary solvent groups by major user category according to county
population or employment data.3 User categories are listed in Table 1. Table 2 contains a list of the
primary solvent groups used to determine losses from organic solvent consumption. The category
"special naphthas" includes the aliphatic naphthas such as varnish makers' and painters' (VMP)
naphthas, Stoddard solvent, rubber solvents, and mineral spirits.
In the algorithm, national consumption of the primary solvent groups is distributed to each of
the user categories according to the percentage of total solvent consumption used by the user
category.3 Percentage usage obtained from published sources is compiled for each user category
shown in Table 3. National area source solvent use estimates are determined by subtracting point
source solvent use or emissions for each user category from total solvent use for each user category.
County consumption for each solvent and user category is then computed by allocating
calculated national area source consumption on the basis of applicable county SIC area source
employment or population, as shown in Table 1. For example, in the degreasing processes user
category, total solvent use is allocated to each county in proportion to the county area source
employment for SICs 34 through 39. Area source employment is determined by subtracting point
source employment from total county employment for each SIC category. For dry cleaning applications,
the county wide allocation is made on the basis of total employment in SICs 7215, 7216, and 7218. To
reflect the unequal solvent use in particular establishments within SIC groups, consumption is multiplied
by a factor, which compares the number of individuals in the county in each area source user category
to the number of individuals in the nation in each area source user category. County consumption of
each solvent type is then summed for each county to yield a total county consumption.
The reported national consumption of each solvent is extracted from DOE Petroleum Supply
Annuaf* and ITC's Synthetic Organic Chemicals.27 The percentage of each solvent consumed by each
solvent user category is obtained from Chemical Products Synopsis53 and Chemical Profiles.5* Total
employment is obtained from County Business Patterns.22 Point source employment is estimated using
plant data from the AIRS/FS20 and employment data from County Business Patterns.22 Solvent
consumption amounts used for surface coating are taken from the annual Trends" report.55 County
population is obtained from Current Population Reports.16
6-1
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TABLE 1: USER CATEGORIES
User Categories
Population or Employment Data by SIC Used for
County Allocation
Surface Coating
Architectural Coatings (AC)
Auto Refinishing (AR)
Textile Products (TP)
Flatwood Products (FP)
Wood Furniture (WF)
Metal Furniture (MF)
Paper (PA)
Plastic Products (PP)
Cans (CN)
Metal Coils (MC)
Misc. Finished Metals (MM)
Electrical (EC)
Large Appliances (LA)
Magnet Wire (MW)
Motor Vehicles (MV)
Aircraft (Al)
Marine (MA)
Railroad (RR)
Miscellaneous Manufacturing (MS)
County Population
SIC 7535
SIC 22
SIC 243 + 244
SIC 25 partial
SIC 25 partial
SIC 26
SIC 308
SIC 341
SIC 3498
SIC 34-(341+3498)
SIC 35
SIC 363
SIC 36 - 363
SIC 371
SIC 372
SIC 373
SIC 374
Total Mfg. - Above SIC employment
Degreasing (DG)
Dry Cleaning (DC)
Graphic Arts (GA)
Rubber & Plastics (RP)
Miscellaneous Industrial (Ml)
Miscellaneous Nonlndustrial (MN)
SIC 34 - 39
SIC (7216x2)+ 7215+ 7218
SIC 264 + 265 + 27
SIC 30
SIC 20 - 39
County Population
TABLE 2: ORGANIC SOLVENTS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Special Naphthas
Perchloroethylene
Ethanol
Trichloroethylene
Isopropanol
Acetone
Glycol Ethers
Cyclohexanone
Methyl Ethyl Ketone
Ethyl Benzene
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Propylene Glycol
Methanol
Butyl Acetate
Ethyl Acetate
Butyl Alcohols
Methyl Isobutyl Ketone
Monochlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
All Other Solvents'
6-2
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TABLE 3: PERCENTAGE END USE OF SOLVENTS BY MAJOR SOLVENT CATEGORY
Solvent Type
Special Naphthas
Perchloroethylene
Ethanol
Trichloroethytene
Isopropanol
Acetone
Glycol Ethers
Cydohexanone
Methyl Ethyl Ketone
Ethyl Benzene
Propylene Glycol
Methanol
Butyl Acetate
Ethyl Acetate
Butyl Alcohols
Methyl Isobutyl Ketone
Monochlorobenzene
o-Dichlorobenzene
p-Dchkxobenzene
All Other Solvents'
Surface
Coating
48.7
15.0
17.0
43.0
69.4
65.0
41.0
15.5
65.5
Degreasing
6.7
10.0
80.0
21.0
Dry
Cleaning
2.0
53.0
Graphic
Arts
6.4
5.0
Rubber &
Plastics
9.6
54.0
8.0
23.0
Miscellaneous
Industrial
7.1
26.0
9.0
10.0
5.0
10.0
4.0
8.0
1.8
8.0
21.0
25.0
Miscellaneous
Non-Industrial
10.7
4.0
5.0
37.0
11.5
0.5
6.0
15.0
3.0
13.0
1.3
18.0
11.0
5.0
46.0
6-3
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* All Other Solvents (AOS) is calculated in the following manner:
AOS = 0.0018 (NTSCSC + NTSC^ + NTSCMI + NTSCMN)
where: AOS = All other solvents
= National solvent consumption due to surface coating (computed
below)
= National solvent consumption due to graphic arts (computed
below)
NTSCMI = National solvent consumption due to miscellaneous industrial
applications (computed below)
NTSCMN = National solvent consumption due to miscellaneous
nonindustrial applications (computed below)
is computed as follows:
NTSC .
2000
where: CST. = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
= National percent of solvent due to surface coating for each of
20 solvent types
is computed as follows:
where: CST, = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
NSPG/U = National percent of solvent due to the graphic arts trades for
each of 20 solvent types
NTSCM, is computed as follows:
6-4
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where: CST, = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
NSPMU = National percent of solvent due to the miscellaneous industrial
trades for each of 20 solvent types
NTSCMN is computed as follows:
CST
NTSCm - >
MN 2000
where: CST. = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
NSPMNt, = National percent of solvent due to the miscellaneous
nonindustrial trades for each of 20 solvent types
The term 's', used throughout Section 6, indicates the list of primary solvent groups used to
determine losses from organic solvent consumption. The category "special naphthas" includes the
aliphatic naphthas such as VMP naphthas, Stoddard solvent, rubber solvents, and mineral spirits.
where: s = Solvents listed in Table 2
6-5
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SURFACE COATING
An estimate of County Organic Solvent Consumption for Surface Coating at each of 19 different
user categories (COS.J (in short tons) is computed as follows:
20
T
*
s=l
wosu.
where: COS,,,, - Estimated county organic solvent consumption for surface
coating - architectural uses
uc =1 for Architectural Coating (County Population)
2 for Auto Refinishing (SIC 7535)
3 for Textile Products (SIC 22)
4 for Flatwood Products (SIC 243 + 244)
5 for Wood Furniture (SIC 25 partial)
6 for Metal Furniture (SIC 25 partial)
7 for Paper (SIC 26)
8 for Plastic Products (SIC 308)
9 for Cans (SIC 341)
10 for Metal Coils (SIC 3498)
11 for Miscellaneous Finished Metals (SIC 34 except 341 &
3498)
12 for Electrical (SIC 35)
13 for Large Appliances (SIC 363)
14 for Magnet Wire (SIC 36 - 363)
15 for Motor Vehicles (SIC 371)
16 for Aircraft (SIC 372)
17 for Marine (SIC 373)
18 for Railroad (SIC 374)
19 for Miscellaneous Manufacturing (Total Mfg. - Above SIC
employment)
CE^ = Total current county area source employment or population for
a given surface coating user category
= Total point source county employment for a given surface
coating user category
= Total national employment or population for a given surface
coating user category
= Total point source employment for a given surface coating user
category
= National organic solvent consumption for 20 different solvent
types for use in architectural coatings (computed below)
NOTE: For the architectural surface coating category, the terms "CPE" and "NPE" equal zero.
6-6
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NOS is computed as follows:
NOS,
CST
UC,3
2000
where: CST.
PSU..
PSU.
uc,s
Published total of national consumption of solvent type s
(pounds)
Percent of solvent type s that is consumed by architectural
uses at area sources (computed below)
is computed as follows:
™«-
17
E
t/c=3
NPE
UC
NE.
uc
NPE,
uc
uc
NE.
uc
ASCU,
sc
TUSC
'SC
PSCA
SC,s
where:
uc
Reference 55 - amount of solvent consumption due to a given
surface coating user category (uc)
National point source employment in a given SIC group
National employment in a given SIC group
3 for Textile Products (SIC 22)
4 for Flatwood Products (SIC 243 + 244)
5 for Wood Furniture (SIC 25 partial)
6 for Metal Furniture (SIC 25 partial)
7 for Paper (SIC 26)
8 for Plastic Products (SIC 308)
9 for Cans (SIC 341)
10 for Metal Coils (SIC 3498)
11 for Miscellaneous Finished Metals (SIC 34 except 341 &
3498)
12 for Electrical (SIC 35)
13 for Large Appliances (SIC 363)
14 for Magnet Wire (SIC 36 - 363)
15 for Motor Vehicles (SIC 371)
16 for Aircraft (SIC 372)
17 for Marine (SIC 373)
18 for Railroad (SIC 374)
19 for Miscellaneous Manufacturing (Total Mfg. - Above SIC
employment)
Area source solvent consumption at surface coating operations
- uncontrolled (computed below)
Total area source solvent consumption due to surface coating
operations at area sources - uncontrolled (computed below)
Percentage of solvent consumption at area sources due to
6-7
-------
surface coatings (SC) for 20 solvent types (computed below)
NOTE: PSU^,. is computed differently for architectural coatings and auto refinishing. The
equations to compute PSU for these two surface coating categories are as follows:
Architectural Coatings: PSU
where: TRAC
TUSCSC
Auto Refinishing: PSU
Reference 55 - amount of solvent consumption due to
architectural coating
Total area source solvent consumption due to surface coating
operations at area sources - uncontrolled (computed below)
Percentage of solvent consumption at area sources due to
surface coatings (SC) for 20 solvent types (computed below)
where: TRAR
Reference 55 -- amount of solvent consumption due to auto
refinishing
Total area source solvent consumption due to surface coating
operations at area sources - uncontrolled (computed below)
Percentage of solvent consumption at area sources due to
surface coatings (SC) for 20 solvent types (computed below)
's computed as follows:
+ TRAC + TRAR
where: ASCUgc
TRAC
TRAR
Area source solvent consumption at surface coating operations
- uncontrolled (computed below)
Reference 55 ~ amount of solvent consumption due to
architectural coating
Reference 55 ~ amount of solvent consumption due to auto
refinishing
6-8
-------
is computed as follows:
TSC
NTSC
SC
where: TSC
SC
NTSC
'SC
NSP,
SC,.
Total area source solvent consumption due to surface coating -
controlled (computed below)
National solvent consumption due to surface coating (computed
below)
National percent of solvent due to surface coating for each of
20 solvent types
is computed as follows:
100 - SCCc
ASCU,
sc
100
+ TRAC + TRAR
where:
Area source solvent consumption due to surface coating -
uncontrolled (computed below)
Percent of control at surface coating operations at area sources
x is computed as follows:
[NTSCSC - (TRAC + TRAR)] -
PTSC,
sc
100 - PTSCC,
sc
100
where:
Point source solvent consumption/emissions from surface
coating - actual (Reference 20)
Percent of control at surface coating operations at point
sources
is computed as follows:
NTSC
~
2000
where: CST.
NSP,
SCj
Published solvent consumption for the nation for each of 20
different solvent types (pounds)
National percent of solvent due to surface coating for each of
20 solvent types
6-9
-------
DEGREASING (SIC 34 through 39)
An estimate of County Organic Solvent Consumption for Degreasing (COS^) (in short tons) is
computed as follows:
DG,s
where: COSoQ = Estimated county organic solvent consumption for degreasing
= Current county employment in the degreasing trades - SICs 34
through 39
= Current county point source employment in the degreasing
trades - SICs 34 through 39
= Current national employment in the degreasing trades -- SICs
34 through 39
= Current national point source employment in the degreasing
trades - SICs 34 through 39
= National organic solvent consumption by the degreasing trades
(computed below)
is computed as follows:
NOSDe. - OST>
0018 2000
where: CST, = Published total of national consumption of solvent type s
(pounds)
PSUDG,» = Percent of solvent type s that is consumed by the degreasing
trades at area sources (computed below)
is computed as follows:
where: PSCA,^ = Percent solvent consumption at area sources due to the
degreasing trade for 20 solvent types (computed below)
is computed as follows:
TSCt
6-10
-------
where:
NSP
DG..
Total area source solvent consumption due to the degreasing
trades - controlled (computed below)
National solvent consumption due to the degreasing trades
(computed below)
National percent of solvent due to the degreasing trade for
each of 20 solvent types
is computed as follows:
TSC -ASCU
I^ ~ A^U
10°-SCC
°s
where: ASCll
^
Area source solvent consumption due to the degreasing trades
- uncontrolled (computed below)
Percent of control at degreasing trades at area sources
is computed as follows:
PTSC,
'DG
100 -
100
where:
Point source solvent consumption/emissions from degreasing
operations - actual (Reference 20)
Percent of control at degreasing operations at point sources
is computed as follows:
s=1
where: CST,
Published solvent consumption for the nation for each of 20
different solvent types (pounds)
National percent of solvent due to the degreasing trades for
each of 20 solvent types
6-11
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DRY CLEANING (SIC 7215, 7216 and 7218)
An estimate of County Organic Solvent Consumption for Dry Cleaning (COSDC) (in short tons) is
computed as follows:
COS.* =
DC
20
where:
Estimated county organic solvent consumption for dry cleaning
Current county employment in the dry cleaning trades -- SICs
7215 + 7218 + (2 * 7216)
Current county point source employment in the dry cleaning
trades -- SICs 7215 + 7218 + (2 * 7216)
Current national employment in the dry cleaning trades - SICs
7215 + 7218 + (2 - 7216)
Current national point source employment in the dry cleaning
trades - SICs 7215 + 7218 + (2 * 7216)
National organic solvent consumption by the dry cleaning
trades for 20 different solvent types (computed below)
is computed as follows:
NOS
CST
2000
where: CST.
PSU
DC,.
Published total of national consumption of solvent type s
(pounds)
Percent of solvent type s that is consumed by the dry cleaning
trade at area sources (computed below)
^ is computed as follows:
where:
Percent solvent consumption at area sources due to the dry
cleaning trade for 20 solvent types (computed below)
is computed as follows:
TSC
NSP
°°->
6-12
-------
where:
NTSC
DC
Total area source solvent consumption due to the dry cleaning
trades - controlled (computed below)
National solvent consumption due to the dry cleaning trades
(computed below)
National percent of solvent due to the dry cleaning trade for
each of 20 solvent types
is computed as follows:
= ASCU
100 - SCCt
'DC
DC
100
where: ASCII
'DC
sec,
DC
Area source solvent consumption due to the dry cleaning trades
- uncontrolled (computed below)
Percent of control at dry cleaning trades at area sources
is computed as follows:
PTSCt
'DC
100 -
oo
where:
Point source solvent consumption/emissions from dry cleaning
operations - actual (Reference 20)
Percent of control at dry cleaning operations at point sources
is computed as follows:
where: CST
Published solvent consumption for the nation for each of 20
different solvent types (pounds)
National percent of solvent due to the dry cleaning trades for
each of 20 solvent types
6-13
-------
GRAPHIC ARTS (SIC 264, 265, and 27)
An estimate of County Organic Solvent Consumption for Graphic Arts (COSGA) (in short tons) is
computed as follows:
20 "^ , - CPE,
GA
where: COS^ = Estimated county organic solvent consumption for graphic arts
Current county employment in the graphic arts trades -- SICs
264 + 265 + 27
Current county point source employment in the graphic arts
trades - SICs 264 + 265 + 27
Current national employment in the graphic arts trades -- SICs
264 + 265 + 27
= Current national point source employment in the graphic arts
trades - SICs 264 + 265 + 27
= National organic solvent consumption by the graphic arts trades
for 20 different solvent types (computed below)
is computed as follows:
CST.
NOS*> - ^looo
where: CST, = Published total of national consumption of solvent type s
(pounds)
PSLW, = Percent of solvent type s that is consumed by the graphic arts
trades at area sources (computed below)
PSUGA.. is computed as follows:
where: PSCA^ *= Percent solvent consumption at area sources due to the
graphic arts trades for 20 solvent types (computed below)
is computed as follows:
6-14
-------
where: TSC
GA
NTSC
QA
NSP
GA..
Total area source solvent consumption due to the graphic arts
trades - controlled (computed below)
National solvent consumption due to the graphic arts trades
(computed below)
National percent of solvent due to the graphic arts trades for
each of 20 solvent types
is computed as follows:
- AsoU
sA
where: ASCU^
SCC
GA
Area source solvent consumption due to the graphic arts trades
- uncontrolled (computed below)
Percent of control at graphic arts trades at area sources
is computed as follows:
ASCUu =
PTSC,
GA
100 -
100
where: PTSC
^
Point source solvent consumption/emissions from graphic arts
operations - actual (Reference 20)
Percent of control at graphic arts operations at point sources
NTSCGA is computed as follows:
^ = * (CST, - NSP^
s=1 I
2000
where: CST.
Published solvent consumption for the nation for each of 20
different solvent types (pounds)
National percent of solvent due to the graphic arts trades for
each of 20 solvent types
6-15
-------
RUBBER/PLASTICS (SIC 30)
An estimate of County Organic Solvent Consumption for Rubber/Plastics (COSRP) (in short tons)
is computed as follows:
20
NE -
RP - RP
where: COSRP = Estimated county organic solvent consumption for
rubber/plastics
CERP = Current county employment in the rubber/plastics trades - SIC
30
CPEpp = Current county point source employment in the rubber/plastics
trades - SIC 30
NERP = Current national employment in the rubber/plastics trades - SIC
30
NPERP = Current national point source employment in the rubber/plastics
trades - SIC 30
NOSflp,. = National organic solvent consumption by the rubber/plastics
trades for 20 different solvent types (computed below)
NOSRP, is computed as follows:
2000
where: CST. = Published total of national consumption of solvent type s
(pounds)
PSURP3 = Percent of solvent type s that is consumed by the
rubber/plastics trades at area sources (computed below)
PSURP, is computed as follows:
where: PSCA^ = Percentage of solvent consumption at area sources due to the
rubber/plastics trades for 20 solvent types (computed below)
6-16
-------
is computed as follows:
TSC>
where: TSCRP = Total area source solvent consumption due to the
rubber/plastics trades - controlled (computed below)
NTSCRP = National solvent consumption due to the rubber/plastics trades
(computed below)
NSPRP* = National percent of solvent due to the rubber/plastics trades for
each of 20 solvent types
TSCnp is computed as follows:
TSCRP - ASCURP
where: ASCURP = Area source solvent consumption due to the rubber/plastics
trades - uncontrolled (computed below)
= Percent of control at rubber/plastics trades at area sources
is computed as follows:
ASCURp =
PTSCRP
100 - PTSca
RP
100
where: PTSCRP = Point source solvent consumption/emissions from
rubber/plastics operations - actual (Reference 20)
PTSCCRP = Percent of control at rubber/plastics operations at point sources
NTSCRP is computed as follows:
CST • NSP
NTSCRP =
where: CST. = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
^ = National percent of solvent due to the rubber/plastics trades for
each of 20 solvent types
6-17
-------
MISCELLANEOUS INDUSTRIAL (SIC 20-39)
An estimate of County Organic Solvent Consumption for Miscellaneous Industrial Trades
(COSMI) (in short tons) is computed as follows:
where: COSM, = Estimated county organic solvent consumption for
miscellaneous industrial trades
CEMI = Current county employment in the miscellaneous industrial
trades •- SICs 20 through 39
NEMI = Current national employment in the miscellaneous industrial
trades -- SICs 20 through 39
NOSMI,s = National organic solvent consumption by the miscellaneous
industrial trades for each of 20 solvent types (computed below)
NOSMU is computed as follows:
NOS - °ST>
NOS«'-' 2000
where: CST, = Published total of national consumption of solvent type s
(pounds)
PSUMU = Percent of solvent type s that is consumed by the
miscellaneous industrial trades at area sources (computed
below)
PSUMU is computed as follows:
where: PSCAu,. = Percent solvent consumption at area sources due to the
miscellaneous industrial trades for 20 solvent types (computed
below)
PSCAMU is computed as follows:
TSC
PSCA"'-
6-18
-------
where: TSCM, = Total area source solvent consumption due to the
miscellaneous industrial trades - controlled (computed below)
NTSCMI = National solvent consumption due to the miscellaneous
industrial trades (computed below)
NSPMU = National percent of solvent due to the miscellaneous industrial
trades for each of 20 solvent types
TSCMI is computed as follows:
TSCU/ - ASCUMI
where: ASCUMI = Area source solvent consumption due to the miscellaneous
industrial trades - uncontrolled (computed below)
SCCM{ = Percent of control at miscellaneous industrial trades at area
sources
ASCUMI is computed as follows:
ASCUMI = NTSCMI -
Ml
100 - PTSCCMI
100
where: PTSCM, = Point source solvent consumption/emissions from
miscellaneous industrial operations - actual (Reference 20)
PTSCCMI = Percent of control at miscellaneous industrial operations at
point sources
NTSCMI is computed as follows:
„_-- ^ , 9 NSPMl.s
NTSC»' ' £ ( 2000
where: CST. = Published solvent consumption for the nation for each of 20
different solvent types (pounds)
NSPMI = National percent of solvent due to the miscellaneous industrial
trades for each of 20 solvent types
6-19
-------
MISCELLANEOUS NONINDUSTRIAL
An estimate of County Organic Solvent Consumption for Miscellaneous Nonindustrial Trades
(COSMN) (in short tons) is computed as follows:
20
MN , D~~ MN,S\
S=1
where: COSMN = Estimated county organic solvent consumption for
miscellaneous nonindustrial trades
CPMN = Current county population
NPMN = Current national population
NOSMN,I = National organic solvent consumption by the miscellaneous
nonindustrial trades for each of 20 solvent types (computed
below)
NOSMN. is computed as follows:
CST*
where: CST. * Published total of national consumption of solvent type s
(pounds)
pSUMN>t = Percent of solvent type s that is consumed by the
miscellaneous nonindustrial trades at area sources (computed
below)
PSUMN. is computed as follows:
where: PSCA^ = Percent solvent consumption at area sources due to the
miscellaneous nonindustrial trades for 20 solvent types
(computed below)
is computed as follows:
TSC
NSP
6-20
-------
where: TSC
MN
NTSC
MN
NSP
MN..
Total area source solvent consumption due to the
miscellaneous nonindustrial trades - controlled (computed
below)
National solvent consumption due to the miscellaneous
nonindustrial trades (computed below)
National percent of solvent due to the miscellaneous
nonindustrial trades for each of 20 solvent types
TSCMN is computed as follows:
100 - SCC
MN
100
where: ASCU
MN
SCCMN =
ASCUMN is computed as follows:
Area source solvent consumption due to the miscellaneous
nonindustrial trades - uncontrolled (computed below)
Percent of control at miscellaneous nonindustrial trades at area
sources
ASCU = NTSC
MN
MN
PTSCt
MN
100 - PTSCC
MN
100
where: PTSCMN
PTSCCMN
Point source solvent consumption/emissions from
miscellaneous nonindustrial operations - actual (Reference 20)
Percent of control at miscellaneous nonindustrial operations at
point sources
NTSCMN is computed as follows:
20
5=1
where: CST,
NSPMNit
Published solvent consumption for the nation for each of 20
different solvent types (pounds)
National percent of solvent due to the miscellaneous
nonindustrial trades for each of 20 solvent types
SOLVENT UTILIZATION EMISSION FACTORS
Emission factors for release of VOC assume complete evaporation of all organic solvents (2000
pounds per ton of solvent used).
6-21
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SECTION 7
SOLID WASTE DISPOSAL
The area source category for solid waste disposal includes on-site refuse disposal activities by
residential, commercial/institutional, and industrial sectors. In this section, emissions from the disposal
practices of open burning and on-site incineration are discussed separately. Solid waste generation in
short tons is used as a measure of activity level.
ON-SITE INCINERATION
For the purposes of determining the amount of solid waste generated, on-site incineration is
defined as disposal in a small incinerator. Using this definition, incineration encompasses the following
types of disposal units: backyard burners (residential), industrial incinerators (industrial), and
incinerators used by food and department stores, hospitals, and schools (commercial/institutional).
Since large municipal incinerators are usually classified as point sources, emissions resulting from
disposal in this type of incinerator have not been included in this category.
The quantity of solid waste generated by each sector was estimated for the base year 1976
using population statistics and per capita generation factors for each EPA region. The regional factors
were derived from the 1968 National Survey of Community Solid Waste Practices. Interim Report56 and
the Preliminary Data Analysis.57 Allocation was based on county population.15
Since 1976, the previous year's estimates of waste generated by each sector have been
updated each year by the same percentage as the relative national percentage increase or decrease in
the amount of waste generated (or incinerated) by point sources in each respective sector. For the
commercial/institutional and industrial sectors, the annual increase or decrease in waste incinerated by
the point source (Reference 55) categories within each sector is used. The annual residential update
factor is based on engineering judgement and calculations by the EPA.
Adjustments are made to county estimates, based on information about specific point sources
and data submitted by States. If a number of on-site incinerators have been identified as point sources,
it may be appropriate to reduce or eliminate area source estimates. Also, it is important to note that
estimates of waste generated that are submitted by the States replace the extrapolated data for the
year they are submitted. Submitted data are then annually updated by the above method using the
relative percentage increase in waste generated.
Previous estimates of waste generated are available from the NEDS point source data -
currently AIRS/FS Point Source Data Files.20 Annual national update factors are calculated using
incineration data from National Air Pollutant Emission Estimates 1940-1
7-1
-------
Solid Waste: Residential On-Slte Incineration
Solid Waste: Residential On-Slte Incineration Equations -
County estimates of Residential On-Site Incineration (ROSI) (in short tons) are computed using
the following equation:
ROSI = cCROSI • SROSI
E CROSIn
n=1
where: ROSI = Estimated county residential on-site incineration
CROSI = County estimate of residential on-site incineration on AIRS AMS
statistical file
SROSI = Reported residential on-site incineration by State
c = Number of counties in State
If SROSI is not available, then the following equation is used:
ROSI = ^ROSI - RROSI
E CROSIn
where: RROSI = Reported residential on-site incineration by Census Region
cr = Number of counties in Census Region
If RROSI is not available, then the following equation is used:
ROSI = nc°ROSI ' NROSI
E CROSIn
where: NROSI = Reported residential on-site incineration for the nation
nc = Number of counties in nation
Solid Waste: Residential On-Slte Emission Factors
Emission factors taken from AP-42, Table 2.1-48 are used with data from the Inventory of
Intermediate Size Incinerators in the United States.56
7-2
-------
Solid Waste: Industrial On-Slte Incineration
Solid Waste: Industrial On-Slte Incineration Equations -
County estimates of Industrial On-Site Incineration (IOSI) (in short tons) are computed using the
following equation:
iosi = closl • siosi
where: IOSI = Estimated county industrial on-site incineration
CIOSI = County estimate of industrial on-site incineration on AIRS AMS
statistical file
SIOSI = Reported industrial on-site incineration by State
c = Number of counties in State
If SIOSI is not available, then the following equation is used:
IOSI = fIOSI - RIOSI
£ ciosin
/7=1
where: RIOSI = Reported industrial on-site incineration by Census Region
cr = Number of counties in Census Region
If RIOSI is not available, then the following equation is used:
IOSI = CIOSI • NIOSI
where: NIOSI = Reported industrial on-site incineration for the nation
nc = Number of counties in nation
Solid Waste: Industrial On-Slte Incineration Emission Factors
Emission factors taken from AP-42, Table 2.1-4B are used with data from the Inventory of
intermediate Size Incinerators in the United States."
7-3
-------
Solid Waste: Commercial/Institutional On-Slte Incineration
Solid Waste: Commercial/Institutional On-Slte Incineration Equations -
County estimates of Commercial/Institutional On-Site Incineration (CIOSI) (in short tons) are
computed using the following equation:
ciosi = ccciosi - sciosi
co/os/n
where: CIOSI = Estimated commercial/institutional on-site incineration
CCIOSI = County estimate of commercial/institutional on-site incineration
on AIRS AMS statistical file
SCIOSI = Reported commercial/institutional on-site incineration by State
c = Number of counties in State
If SCIOSI is not available, then the following equation is used:
ciosi = crccios/ . RCIOSI
E cciosi„
f?=1
where: RCIOSI = Reported commercial/institutional on-site incineration by Census
Region
cr = Number of counties in Census Region
If RCIOSI is not available, then the following equation is used:
CIOSI = ^CIOSI . NCIOSI
£ cciosin
where: NCIOSI = Reported commercial/institutional on-site incineration for the
nation
nc = Number of counties in nation
Solid Waste: Commercial/Institutional On-Slte Incineration Emission Factors -
Emission factors taken from AP-42, Table 2.1-3s are used with data from the Inventory of
Intermediate Size Incinerators in the United States.68
7-4
-------
OPEN BURNING
For the purposes of estimating emissions from open burning practices, open burning refers to
uncombined burning of wastes such as leaves, landscape refuse, and other rubbish. Large open
burning dumps are usually included under point sources.
The quantity of solid waste burned is computed by updating the previous year's waste
generation for each sector. The update factor is determined by engineering judgement. Estimates of
the quantity of solid waste burned in the most recent year are obtained from the AIRS/FS Point Source
Data Files.20 Generation factors were originally obtained from data in the 1968 National Survey of
Community Solid Waste Practices. Interim Report.66 and the Preliminary Data Analysis.57 Allocation
was based on county population.
Solid Waste: Residential Open Burning
Solid Waste: Residential Open Burning Equations -
County estimates of Residential Open Burning (ROB) (in short tons) are computed using the
following equation:
ROB = CROB - SROB
E CROBn
where: ROB «= Estimated residential open burning
CROB - County estimate of residential open burning on AIRS AMS
statistical file
SROB - Reported residential open burning by State
c = Number of counties in State
If SROB is not available, then the following equation is used:
BOB = ^ROB • RROB
CROBn
where: RROB - Reported residential open burning by Census Region
cr e Number of counties in Census Region
7-5
-------
If RROB is not available, then the following equation is used:
ROB = J:ROB • NROB
E
c=1
where: NROB = Reported residential open burning for the nation
nc = Number of counties in nation
Solid Waste: Residential Open Burning Emission Factors -
The emission factors for open burning of refuse and organic materials are taken directly from
AP-42, Table 2.4-1 and 2.4-2."
Solid Waste: Industrial Open Burning
Solid Waste: Industrial Open Burning Equations -
County estimates of Industrial Open Burning (IOB) (in short tons) are computed using the
following equation:
IOB = CIOB • SIOB
where: IOB = County estimate of industrial open burning
CIOB = County estimate of industrial open burning on AIRS AMS
statistical file
SIOB = Reported industrial open burning by State
c = Number of counties in State
If SIOB is not available, then the following equation is used:
IOB = CIOB • RIOB
CIOBn
where: RIOB = Reported industrial open burning by Census Region
cr = Number of counties in Census Region
7-6
-------
If RIOB is not available, then the following equation is used:
IOB = CIOB - NIOB
nc
where: NIOB = Reported industrial open burning for the nation
nc = Number of counties in nation
Solid Waste: Industrial Open Burning Emission Factors -
The emission factors for open burning of refuse and organic materials are taken directly from
AP-42, Table 2.4-2."
Solid Waste: Commercial/Institutional Open Burning
Solid Waste: Commercial/Institutional Open Burning Equations -
County estimates of Commercial/Institutional Open Burning (CIOB) (in short tons) are computed
using the following equation:
CIOB = COIOB - SCIOB
E OCIOBn
where: CIOB = County estimate of commercial/institutional open burning
CCIOB = County estimate of commercial/institutional open burning on
AIRS AMS statistical file
SCIOB = Reported commercial/institutional open burning by State
c = Number of counties in State
If SCIOB is not available, then the following equation is used:
CCIOB
E CCIOBn
n=1
RCIOB
where: RCIOB = Reported commercial/institutional open burning by Census
Region
cr = Number of counties in Census Region
7-7
-------
If RCIOB is not available, then the following equation is used:
CIOB = °°IOB
£ «*».
n=1
where: NCIOB = Reported commercial/institutional open burning for the nation
nc = Number of counties in nation
Solid Waste: Commercial/Institutional Open Burning Emission Factors ~
The emission factors for open burning of refuse and organic materials are taken directly from
AP-42, Table 2.4-1 .•
7-8
-------
SECTION 8
NATURAL SOURCES
Natural sources are known to be significant contributors to area source emissions. Natural
sources may include the following: biogenic sources, wind erosion, lightning, geothermal sources, and
open-water sources. However, while there are numerous methodologies for estimating emissions from
natural sources, experts disagree on the most appropriate methodology to use for estimating emissions
from this category.
MISCELLANEOUS WIND EROSION
In some areas, large dust emissions are generated as a result of windblown dust. At present,
no methodology to estimate activity levels on a county basis is available. No emission factors are
available.
8-1
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SECTION 9
MISCELLANEOUS AREA SOURCES
Area sources which are not defined by Stationary Source Fuel Combustion, Mobile Sources,
Industrial Processes, Solvent Utilization, Solid Waste Disposal, or Natural Sources categories are
compiled in the Miscellaneous Area Sources category. The importance of these area categories is that,
while total emissions from each source are relatively small compared to the major categories, emissions
at a particular time may be significant.
As presented, identified miscellaneous area sources are Agricultural Production and Other
Combustion. Agricultural Production includes Acres Under Cultivation (Land Tilling) and Agricultural
Burning. Other Combustion includes Forest Wildfires, Managed Burning, and Structural Fires.
AGRICULTURE PRODUCTION - CROPS
Acres Under Cultivation (Land Tilling)
Fugitive dust emissions result from various soil preparation operations, which include rough
plowing, mulch plowing, and the cutting of narrow slits into the sod for seed and/or fertilizer. Variables
known to affect the quantity of dust generated are soil type, surface moisture, resulting tool speed, type
of equipment, and wind speed. Activity levels are estimated using the number of acres tilled as
obtained from the Census of Agriculture.39 It was assumed that each acre of harvested cropland is
tilled three times per year. The resultant activity levels are reported in thousands of acres.48
Acres Under Cultivation Equations -
County estimates of Acres Under Cultivation (AUC) (acres) are computed using the following
equation:
AUC =
CAHC
SAHC
E CAHC,,]
where: AUC
CAHC
SAHC
C
County estimate of acres under cultivation
County estimate of harvested cropland as reported by Census
of Agriculture (Reference 38)
Reported acres under cultivation by State
Number of counties in State
9-1
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If SAHC is not available, then the following equation is used:
CAHC
£ CAHC]
1/7=1 )
RAHC
where: RAHC
cr
Reported acres under cultivation by Census Region
Number of counties in Census Region
If RAHC is not available, then the following equation is used:
CAHC
AUC =
NAHC
where: NAHC
nc
Reported acres under cultivation for the nation
Number of counties in nation
Acres Under Cultivation Emission Factors -
The paniculate emission factor is found in AP-42, Section 11.2.2.8
Agricultural Burning
This miscellaneous area source category estimates emissions from agricultural burning
practices routinely used to clear and/or prepare land for planting. Specific operations include grass
stubble burning, burning of agricultural crop residues, and burning of standing field crops as part of
harvesting (e.g., sugar cane). Emissions estimates are generated by multiplying the number of acres
burned in each county by a fuel loading factor and the emission factor for each pollutant.
The original methodology estimated the 1974 activity level in terms of acres burned per State.59
It is assumed that the total quantity of agricultural products burned in 1974 is the same quantity which
will be consumed by fire each year. If no specific crop data were available, it was assumed that the
number of acres burned annually are divided equally between sugar cane and field crops. For the
purposes of these calculations, fuel loadings for grass burning are 1 to 2 short tons per acre; for sugar
cane burning, 6 to 12 short tons per acre.
If new State, regional, or national estimates are available, the existing county data will be
updated by the same percentage as the relative State, regional, or national percentage increase or
decrease.
9-2
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Agricultural Field Burning Equations -
County estimates of Agricultural Field Burning (AFB) (acres) are computed using the following
equation:
AFB = —CAFB - SAFE
where: AFB = County estimate of agricultural field burning
CAFB = County estimate of agricultural field burning on AIRS AMS
statistical file
SAFB = Reported agricultural field burning by State
c = Number of counties in State
If SAFB is not available, then the following equation is used:
AFB CAFB • RAFB
where: RAFB = Reported agricultural field burning by Census Region
cr = Number of counties in Census Region
If RAFB is not available, then the following equation is used:
AFB = —CAFB • NAFB
where: NAFB = Reported agricultural field burning for the nation
nc = Number of counties in nation
Agricultural Field Burning Emission Factors -
Emission factors are taken from the "Trends" Procedures Document41 and AP-42, Table 2.4-2."
OTHER COMBUSTION
Area sources which are defined as "Other Combustion'' include such categories as forest
wildfires, managed burning, and structural fires. The importance of these area categories is that while
total emissions from each source are relatively small compared to the major categories, emissions at a
particular time may be significant.
9-3
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Forest Wildfires
Each year emissions are generated by forest wildfires covering large tracts of forested land.
For this category, emission estimates are generated by multiplying the number of acres burned per
county by a fuel loading factor and then the emission factor.
In the original methodology, State estimates of wildfire activity were allocated to the county level
on the basis of forest acreage per county.59 Wildfire statistics, reported in number of acres burned,
were obtained from contact with State forestry officials and from State land use maps for the base year
of 1974. Since 1974, the wildfire activity level for each county from the previous year has been
updated with wildfire statistics from the U.S. Forest Service.60 Regional fuel loading factors in short
tons per acre for each EPA region from AP-428 are applied to State averages within each region to
yield short tons consumed.
Forest Wildfire Equations -
County estimates of Forest Acres Burned (FAB) (acres) are computed using the following
equation:
FAB = —CFAB • SFAB
where: FAB = County estimate of forest acres burned
CFAB = County estimate of forest acres burned on AIRS AMS statistical
file
SFAB = Reported forest acres burned by State
c = Number of counties in State
If SFAB is not available, then the following equation is used:
FAB = —CFAB - RFAB
where: RFAB = Reported forest acres burned by Census Region
cr = Number of counties in Census Region
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If RFAB is not available, then the following equation is used:
FAB = —CFAB - NFAB
where: NFAB = Reported forest acres burned for the nation
nc = Number of counties in nation
Forest Wildfire Emission Factors -
All emission factors except VOC are taken directly from AP-42, Tables 11.1-1 and 11.1-2.8
Emission factors are applied to a fuel loading parameter, used as a conversion from acres of land
burned to short tons of material burned per acre.
Managed Burning (Slash/Prescribed Burning)
Managed burning activities included in this area source category are slash burning and
prescribed burning. In slash burning operations, wastes from logging operations are burned under
controlled conditions to reduce fire hazard and remove brush considered to serve host to destructive
insects. Prescribed burning is used as a forest management practice to establish favorable seedbeds,
remove competing underbrush, accelerate nutrient cycling, control tree pests, and contribute other
ecological benefits.
For this category, emissions estimates are generated by multiplying the number of acres
burned in each county by a fuel loading factor and the emission factor for each pollutant.
Original State estimates of acreage consumed by both managed burning techniques were
determined for the inventory year of 1974.58 Individual State officials and the U.S. Forest Service were
contacted to provide estimates of acreage burned, burning technique, and fuel loading ratios. AMS
utilizes State data generated for 1974 which were allocated to the county level according to forest
acreage per county as obtained from contact with local officials or State land use maps. If not
provided, fuel loadings for slash burning and prescribed burning are 75 and 3 short tons per acre,
respectively.
If new State, regional, or national estimates are available, the existing county data will be
updated by the same percentage as the relative State, regional, or national percentage increase or
decrease.
9-5
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Managed Burning (Slash/Prescribed Burning) Equations -
County estimates of Managed Burning (MB) (acres) are computed using the following equation:
MB = —CMB • 8MB
where: MB = County estimate of managed burning
CMB = County estimate of managed burning on AIRS AMS statistical
file
8MB » Reported managed burning by State
c = Number of counties in State
If SMB is not available, then the following equation is used:
MB = —CMB • RMB
where: RMB = Reported managed burning by Census Region
cr = Number of counties in Census Region
If RMB is not available, then the following equation is used:
MB = —CMB - NMB
where: NMB = Reported managed burning for the nation
nc = Number of counties in nation
Managed Burning (Slash/Prescribed Burning) Emission Factors -
Paniculate and CO emission factors are obtained from the Source Assessment.61 SO2 and NO,
emission factors are taken directly from AP-42, Table 11.1-3.8
Structural Fires
Structural fires have been included in AMS because building fires have been identified in the
production of short-term emissions of air contaminants. Activity level for this category, measured by the
total number of fires per county, is multiplied by a loading factor and the emission factor to obtain
emissions estimates.
9-6
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The total number of building fires is obtained from the most recent statistics from the National
Fire Protection Association.62 In absence of county-level allocation data, it is assumed, based on the
nationwide figures (Reference 62), that an average of four fires per 1,000 population occur each year.
Estimates of the material burned are obtained by multiplying the number of structural fires by a fuel
factor of 6.8 short tons of material per fire.
If new State, regional, or national estimates are available, the existing county data will be
updated by the same percentage as the relative State, regional, or national percentage increase or
decrease.
Structural Fire Equations -
County estimates of Structural Fires (SF) (number of fires) are computed using the following
equation:
CSF - SSF
where: SF = County estimate of structural fires
CSF = County estimate of structural fires on AIRS AMS statistical file
SSF = Reported structural fires by State
c = Number of counties in State
If SSF is not available, then the following equation is used:
CSF
where: RSF = Reported structural fires by Census Region
cr = Number of counties in Census Region
If RSF is not available, then the following equation is used:
SF = —CSF - NSF
where: NSF = Reported structural fires for the nation
nc «= Number of counties in nation
9-7
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Structural Fire Emission Factors -
Emission factors are based on engineering judgement and background data relating to the
National Air Pollutant Emission Estimates. 1940-1989 (Trends).55
9-8
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SECTION 10
REFERENCES
1. E. S. Kimbrough and A. T. Kelsey, Design and Development of AIRS: Area and Mobile Source
Subsystems. Paper presented at 84th Air & Waste Management Conference, Vancouver,
British Columbia, Canada. June 16-21,1991.
2. J. L. Demmy, W. M. Tax, and T. E. Warn, Area Source Documentation for the 1985 National
Acid Precipitation Assessment Program Inventory. EPA-600/8-88-106 (NTIS PB89-151427),
U.S. EPA, Air and Energy Engineering Research Laboratory, Research Triangle Park, NC,
December 1988.
3. J. P. Myers and F. Benesh, Methodologies for Countywide Estimation of Coal, Gas, and
Organic Solvent Consumption. EPA-450/3-75-086 (NTIS PB259909), U.S. EPA, Office of Air
Quality Planning and Standards, Research Triangle Park, NC, December 1975.
4. Census of Housing: Characteristics of Housing Units: Detailed Housing Characteristics (by
State) (Decennial). U.S. Department of Commerce, Bureau of the Census, Washington, DC.
5. American Housing Survey for the United States. (Biennial) Current Housing Reports, U.S.
Department of Commerce, Bureau of Census, Washington, DC, and U.S. Department of
Housing and Urban Development, Office of Policy Development and Research.
6. Climatological Data. U.S. Department of Commerce, National Oceanic and Atmospheric
Administration, Washington, DC.
7. State Energy Data Report: January-December (Annual). DOE/EIA-0214, U.S. Department of
Energy, Energy Information Administration, Washington, DC.
8. Compilation of Air Pollutant Emission Factors - Volume I: Stationary Point and Area Sources,
Fourth Edition, AP-42 (GPO 055-000-00251-7), U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, NC, 1985 and Volume II: Mobile Sources, Fourth Edition,
AP-42 (GPO 055-000-00252-5), Office of Mobile Sources, Ann Arbor, Ml. 1985.
9. Coal Production (Annual). DOE/EIA-0118. U.S. Department of Energy, Energy Information
Administration, Washington, DC.
10. Coal Distribution: January-December (Annual). DOE/EIA-0125, U.S. Department of Energy,
Energy Information Administration, Washington, DC.
11. J.C. Goldish et al., Development of a Methodology to Allocate Liquid Fossil Fuel Consumption
by County. EPA-450/3-74-021 (NTIS PB232209), U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, NC, March 1974.
12. Fuel Oil and Kerosene Sales (Annual). DOE/EIA-0535, U.S. Department of Energy, Energy
Information Administration, Washington, DC.
13. Heating Oils (Annual). National Institute for Petroleum and Energy Research, Bartlesville, OK.
14. Gas House Heating Survey (Annual). American Gas Association, Arlington, VA.
10-1
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15. Current Population Reports: Local Populations Estimates (Annual). U.S. Department of
Commerce, Bureau of the Census, Washington, DC.
16. Gas Facts: A Statistical Record of the Gas Utility Industry (Annual). American Gas
Association, Arlington, VA.
17. Natural Gas Annual. DOE/EIA-0131, U.S. Department of Energy, Energy Information
Administration, Washington, DC.
18. Estimates of U.S. Wood Energy Consumption, 1949-1981. DOE/EIA-0341, U.S. Department of
Energy, Energy Information Administration, Washington, DC, August 1982.
19. Household Energy Consumption and Expenditures (Triennial). DOE/EIA-0321, U.S.
Department of Energy, Energy Information Administration, Washington, DC.
20. AIRS/FS Point Source Data Files, Office of Air Quality Planning and Standards, U.S. EPA,
Research Triangle Park, NC.
21. Census of Manufacturers: Geographic Area Series (Decennial). U.S. Department of
Commerce, Bureau of Census, Washington, DC.
22. County Business Patterns (Annual). U.S. Department of Commerce, Bureau of Census,
Washington, DC.
23. Manufacturing Energy Consumption Survey (Triennial). DOE/EIA-0512, U.S. Department of
Energy, Energy Information Administration, Washington, DC.
24. Petroleum Supply Annual. DOE/EIA-0340, U.S. Department of Energy, Energy Information
Administration, Washington, DC.
25. Directory of Chemical Producers (Annual). SRI International, Menlo Park, CA.
26. Chemical and Engineering News, Annual June Issue.
27. Synthetic Organic Chemicals, United States Production and Sales (Annual). USITC Publication
1745, U.S. International Trade Commission, Washington, DC.
28. User's Guide to MOBILE4 (Mobile Source Emission Factor Model). EPA-AA-TEB-89-01 (NTIS
PB89-164271), U.S. EPA, Office of Mobile Sources, Ann Arbor, Ml, February 1989.
29. Complete Development and Documentation of NEDS Area Source Methods: Modification of
NE099 and NEB77A. U.S. EPA, Office of Air Quality Planning and Standards, Research
Triangle Park, NC, April 1987.
30. Federal Highway Administration (FHWA). U.S. Department of Transportation, Data on tape
available from FHWA.
31. Highway Statistics (Annual). U.S. Department of Transportation, Federal Highway
Administration, Washington, DC.
32. Census of Transportation: Truck Inventory and Use Survey Microdata-United States
(Quinquennial). U.S. Department of Commerce, Bureau of Census, Washington, DC.
10-2
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33. MOBILES Fuel Consumption Model, EPA-AA-TEB-85-2, U.S. EPA, Office of Mobile Sources,
Ann Arbor, Ml, February 1985.
34. National Vehicle Population Profile Data Tape (Annual). R. L. Polk Company, Detroit, Ml.
35. Motorcycle Statistical Annual. Motorcycle Industry Council, Inc., Research and Statistics
Department, Costa Mesa, CA.
36. Procedure and Basis for Estimating On-Road Motor Vehicle Emissions, Supplement 4.
California Air Resources Board, June 1983.
37. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using Internal
Combustion Engines, Final Report - Part 5: Heavy-Duty Farm, Construction, and Industrial
Engines. EHS-70-108, Southwest Research Institute, San Antonio, TX, October 1973.
38. Census of Agriculture - State and County Data (Quinquennial). U.S. Department of Commerce,
Bureau of Census, Washington, DC.
39. Census of Agriculture - Summary and State Data: United States. Volume I, Part 51. U.S.
Department of Commerce Bureau of Census, Washington, DC.
40. Volatile Organic Compound (VOC) Species Data Manual. EPA-450/4-80-015 (NTIS PB81-
119455), U.S. EPA, Office of Air Quality Planning and Standards, Research Triangle Park, NC,
July 1980.
41. Procedures Document for Development of National Air Pollutant Emissions Trends Report.
Prepared by Pacific Environmental Services for U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, NC, December 1985.
42. North American Snowmobile Registration Survey. Personal communication with Catherine A.
Ahem, International Snowmobile Association, 3975 University Drive, Fairfax, VA 22030.
43. Jane's All the World's Aircraft. Jane's British Publishing Co., London, Great Britain.
44. FAA Aviation Forecasts (Annual). U.S. Department of Transportation, Federal Aviation
Administration, Washington, DC.
45. FAA Air Traffic Activity (Annual). U.S. Department of Transportation, Federal Aviation
Administration, Washington, DC.
46. Census of U.S. Civil Aircraft (Annual). U.S. Department of Transportation, Federal Aviation
Administration, Washington, DC.
47. Military Air Traffic Activity, data obtained from Gene Mercer, U.S. Department of Transportation,
Federal Aviation Administration, Washington, DC.
48. C.C. Cowherd Jr., C.M. Guenther, and D.D. Wallace, Emissions Inventory of Agricultural Tilling,
Unpaved Roads and Airstrips, and Construction Sites. EPA-450/3-74-085 (NTIS PB238919),
U.S. EPA, Office of Air Quality Planning and Standards, Research Triangle Park, NC,
November 1974.
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49. Waterbome Commerce of the United States (Annual). U.S. Department of the Army, Corps of
Engineers, New Orleans, LA.
50. Boating Registration Statistics (Annual). National Marine Manufacturers Association, New York,
NY.
51. Area Measurement Reports: U.S. Summary. GE 20, No. 1, U.S. Department of Commerce,
Bureau of Census, Washington, DC.
52. Census of Retail Trade: Geographic Area Series (Quinquennial). U.S. Department of
Commerce, Bureau of Census, Washington, DC.
53. Chemical Products Synopsis. Mannsville Chemical Products Corporation, Cortland, NY.
54. "Chemical Profiles" in Chemical Marketing Reporter (Weekly). Schnell Publishing Company,
New York, NY.
55. National Air Pollutant Emission Estimates. 1940-1989 (Annual). EPA-450/4-91-004 (NTIS
PB91-168559), U.S. EPA, Office of Air Quality Planning and Standards, Research Triangle
Park, NC, March 1991.
56. 1968 National Survey of Community Solid Waste Practices, Interim Report. U.S. Department of
Health, Education and Welfare, Public Health Services, Cincinnati, OH, 1968.
57. 1968 National Survey of Community Solid Waste Preliminary Data Analysis. U.S. Department
of Health, Education and Welfare, Public Health Services, Cincinnati OH, 1968.
58. Inventory of Intermediate Size Incinerators in the United States 1972. Pollution Engineering,
November 1973.
59. G. Yamate, Emissions Inventory from Forest Wildfires, Forest Managed Bums, and Agricultural
Bums. EPA-450/3-74-062 (NTIS PB238766), U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, NC, November 1974.
60. Wildfire Statistics. U.S. Department of Agriculture, Forest Service, Washington, DC.
61. C.T. Chi et al., Source Assessment: Prescribed Burning, State-of-the-Art. EPA-600/2-79-019h
(NTIS PB80-181472), U.S. EPA, Industrial Environmental Research Laboratory, Research
Triangle Park, NC, November 1979.
62. Structural Fire Statistics. National Fire Protection Association, Boston, MA.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600-R-92-001
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Documentation of AIRS AMS National Methodologies
5. REPORT DATE
January 1992
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
E. Sue Kimb rough
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
See Block 12
11. CONTRACT/GRANT NO.
NA (Inhouse)
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 1-5/91
14..SPONSORING AGENCY CODE
EPA 7600/13
is.SUPPLEMENTARY NOTES Author Kimbrough's Mail Drop is 62; her phone is 919/541-2612.
is.ABSTRACT-phe report provides an understanding of the estimation procedures that will
be used by the national component of the Area and Mobile Source Subsystem (AMS)
to generate emissions estimates for area and mobile source categories. General
methodology and assumptions are discussed as well as the original source of algo-
rithms, activity levels, and emission factors necessary to calculate emissions for
each area and mobile source in AMS. The report presents methodologies for all
identified sources not defined as point sources. Area and mobile sources are divi-
ded into seven major groups: stationary source fuel combustion, mobile sources,
industrial processes, solvent utilization, solid waste disposal, natural sources, and
miscellaneous area sources. Historically, these methodologies have been referred
to as the National Emissions Data System (NEDS) methods and to some extent were
described in area source documentation for the 1985 National Acid Precipitation
Assessment Program (NAPAP) inventory; however, the NAPAP documentation did
not include certain initial data calculations. In addition, over the years many chan-
ges have occurred to the sources of the data that feed these methodologies. These
initial data calculations and source data changes are included in the report.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Emission
Estimating
Fuels
Combustion
Industrial Processes
Solvents
Waste Disposal
Pollution Control
Stationary Sources
Mobile Sources
Emission Factors
13 B
14G
21D
21B
13H
11K
15E
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
147
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
10-5
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