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
                                             3-3

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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.
                                           3-4

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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

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       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

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             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

-------
              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

-------
        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

-------
              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

-------
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

-------
       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

-------
       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

-------
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

-------
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

-------
       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

-------
       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

-------
                     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

-------
       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

-------
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

-------
              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

-------
       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

-------
 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

-------
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

-------
        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

-------
       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

-------
              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

-------
       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

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                                         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

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               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

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                                    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

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       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

-------
             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

-------
      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

-------
       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

-------
              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

-------
       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

-------
        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

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                                   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
                                 4-19

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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

-------
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

-------
       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

-------
       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

-------
       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

-------
                         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

-------
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

-------
* 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

-------
       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

-------
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

-------
       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

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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

-------
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

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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

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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

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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

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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

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                                        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

-------
               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

-------
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
                                            9-4

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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.
                                            10-3

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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.
                                            10-4

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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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