United States

Environmental Protection

Agency

Air and Radiation EPA420-P-02-013

December 2002

User’s Guide for the

EPA Nonroad Emissions

Model Draft NONROAD 2002

 Printed on Recycled Paper
EPA420-P-02-013

December 2002

User’s Guide for the EPA Nonroad

Emissions Model Draft NONROAD 2002

Assessment and Standards Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency

Prepared for EPA by

ENVIRON International Corporation

EPA Contract No. DW47926801

NOTICE

This technical report does not necessarily represent final EPA decisions or positions.

It is intended to present technical analysis of issues using data that are currently available.

The purpose in the release of such reports is to facilitate the exchange of

technical information and to inform the public of technical developments which

may form the basis for a final EPA decision, position, or regulatory action.
December 2002

EPA NONROAD Emissions Model User’s Guide i

TABLE OF CONTENTS

Page

1. INTRODUCTION ....................................................... 1-1

Overview of the EPA Nonroad Emissions Model ................................ 1-2

Equipment Types ...................................................... 1-2

Pollutants Reported .................................................... 1-2

Geographic and Temporal Coverage ....................................... 1-2

Model Components .................................................... 1-3

Model Inputs ......................................................... 1-5

Output Options ........................................................ 1-6

Technical Documentation .................................................. 1-7

 Future Model Updates ..................................................... 1-8

To Stay Informed ......................................................... 1-8

Conventions Used in the User's Guide ......................................... 1-8

Organization of the User’s Guide ........................................... 1-10

2. GETTING STARTED .................................................... 2-1

Quick Start .............................................................. 2-1

System Requirements for Running the NONROAD Model ........................ 2-1

Installing the NONROAD Model ............................................ 2-2

Attaching the Reporting Utility Databases .................................. 2-2

Reinstalling the NONROAD Model .......................................... 2-3

3. GRAPHICAL USER INTERFACE ......................................... 3-1

Quick Start .............................................................. 3-1

General Description ....................................................... 3-2

Moving Around in the Graphical User Interface ................................. 3-3

Creating an Option File .................................................... 3-5

Opening and Naming an Option File ....................................... 3-5

Defining a Report Title ................................................. 3-6

Defining Fuel Specifications, and Ambient Temperatures and Stage II Effectiveness . 3-7

Defining the Modeling Period ............................................ 3-9

Defining the Modeling Region .......................................... 3-10

Defining Source Categories ............................................. 3-12

Saving an Option File ................................................. 3-15

Running and Viewing a Modeling Scenario ................................... 3-15

Advanced Options ....................................................... 3-17
December 2002

EPA NONROAD Emissions Model User’s Guide ii

Examples of Changing Geographic Allocation ................................. 3-17

Exiting the Graphical User Interface ......................................... 3-19

4. CORE MODEL ......................................................... 4-1

Quick Start .............................................................. 4-1

General Description ....................................................... 4-2

Creating an Option File .................................................... 4-2

Modifying /RUNFILES/ ................................................ 4-4

Modifying /OPTIONS/ .................................................. 4-5

Modifying /PERIOD/ ................................................... 4-7

Modifying /REGION/ .................................................. 4-9

Modifying /SOURCE CATEGORY/ ...................................... 4-11

Modifying the /POP FILES/ and /ALLOC Files/ Packet ....................... 4-12

Saving an Option File ................................................. 4-15

Running the Core Model .................................................. 4-15

Error Stop Feature .................................................... 4-16

5. REPORTING UTILITY .................................................. 5-1

Quick Start .............................................................. 5-1

General Description ....................................................... 5-2

The Reporting Utility Menus ................................................ 5-2

Import, Delete, and Re-Attach ............................................... 5-4

Importing Core Model Output ............................................ 5-4

Removing a Simulation ................................................. 5-6

Attaching the Reporting Utility Databases .................................. 5-7

Report Types ............................................................ 5-8

User Specifications ....................................................... 5-9

Generating Reports ...................................................... 5-12

Running a Report ..................................................... 5-12

Viewing a Report in Print Preview ....................................... 5-12

Exporting to Excel .................................................... 5-14

Comparing Model Runs ................................................... 5-15

Compacting and Repairing Databases ........................................ 5-17
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EPA NONROAD Emissions Model User’s Guide iii

6. ADVANCED TOPICS .................................................... 6-1

Introduction ............................................................. 6-1

How Data Are Grouped in the Nonroad Model .................................. 6-2

Input Data Packets and Data Files ............................................ 6-4

Review of Previously Described Packets .................................... 6-4

Runfiles Packet ....................................................... 6-5

Activity ........................................................... 6-5

Alloc XREF ....................................................... 6-7

Regions ......................................................... 6-10

Seasonality ....................................................... 6-11

Technology ....................................................... 6-12

Population Files Packet ................................................ 6-15

Growth Files Packet ................................................... 6-18

Allocation Files Packet ................................................ 6-22

Modifying Inputs for Subcounty Runs .................................. 6-24

Emissions Factors Files Packet .......................................... 6-28

Data Files in the /EMFAC FILES/ Packet ............................... 6-29

Deterioration Factors Files Packet ........................................ 6-32

Data Files in the /DETERIORATE FILES/ Packet ........................ 6-33

PM Base Sulfur Packet ............................................. 6-34

Editing Input Data Packets and Files ......................................... 6-34

Making Multiple Model Runs .............................................. 6-35

7. TROUBLE SHOOTING .................................................. 7-1

Message File ............................................................ 7-1

Data File Relationships .................................................... 7-4

Allocation Files ....................................................... 7-4

Population Data ....................................................... 7-4

APPENDICES

Appendix A: FIPS Codes

Appendix B: Source Classification Codes (SCC) and Definitions

Appendix C: Examples of Standard Reports

Appendix D: Examples of Model Comparison Reports
December 2002

EPA NONROAD Emissions Model User’s Guide iv

FIGURES

Figure 1-1. Nonroad Model Flowchart ......................................... 1-4

Figure 3-1. Graphical User Interface icon. ...................................... 3-3

Figure 3-2. Initial graphical user interface screen ................................. 3-3

Figure 3-3. Options screen .................................................. 3-7

Figure 3-4. Period screen ................................................... 3-9

Figure 3-5. Region screen .................................................. 3-11

Figure 3-6. Sources screen ................................................. 3-13

Figure 3-7. Model submenu screen .......................................... 3-16

Figure 3-8. Geographic allocation screen ...................................... 3-18

Figure 4-1. Portion of the TEMPLATE.OPT file ................................. 4-4

Figure 4-2. TRAVIS.OPT/RUNFILES/ packet .................................. 4-5

Figure 4-3. Modified /OPTIONS/ packet ....................................... 4-7

Figure 4-4. Modified /PERIOD/ packet ........................................ 4-8

Figure 4-5. Modified /REGION/ packet ....................................... 4-10

Figure 4-6. Modified /SOURCE CATEGORY/ packet ........................... 4-12

Figure 4-7. Modified /POP FILES/ packet ..................................... 4-13

Figure 4-8. Modified /ALLOC FILES/ packet .................................. 4-14

Figure 4-9. DOS window showing successful model run ......................... 4-16

Figure 5-1. Initial report utility screen ......................................... 5-3

Figure 5-2. Import core model data screen ...................................... 5-5

Figure 5-3. User-specified report options screen ................................ 5-10

Figure 5-4. Report title area ................................................ 5-13

Figure 5-5. Report options for comparing two model runs ........................ 5-16

Figure 5-6. Report options for comparing two model runs by population and fuel ...... 5-17

Figure 5-7. Identify a directory for temporary storage screen ...................... 5-19

Figure 6-1. Option file showing packet identifiers and terminators ................... 6-3

Figure 6-2. /ALLOC FILES/ packet .......................................... 6-23

Figure 6-3. Modified TX.pop file with population estimates for 2-stroke 

residential lawn mowers in Travis County ........................... 6-26

Figure 6-4. Modified TX_house.alo file showing housing of Austin. ................ 6-26

Figure 6-5. Modified /REGION/ packet showing subcounty region ................. 6-27

Figure 6-6. /EMFAC FILES/ packet .......................................... 6-29

Figure 6-7. /DETERIORATION FILES/ packet ................................ 6-32

Figure 6-8. Batch file milg.bat. .............................................. 6-35

Figure 7-1. Output message file .............................................. 7-2
December 2002

1

EPA, Nonroad Engine and Vehicle Emission Study, EPA-21A-2001, November 1991.

EPA NONROAD Emissions Model User’s Guide 1-1

Chapter 1 Introduction

Air pollution in the United States results from the emission of a wide variety of manmade and

natural pollutants such as volatile organic compounds (VOC) , nitrogen oxides (NOX), air toxics,

and particulate matter (PM). Under the Clean Air Act, the U.S. Environmental Protection

Agency (EPA) is given specific responsibilities to reduce the emissions of pollutants from a

range of sources in order to provide clean and healthy air in the United States.

Generally speaking, the EPA classifies anthropogenic (manmade) emissions into three broad

categories, mobile, stationary (point), and area sources. Mobile source emissions are further

disaggregated into on-road (e.g., cars, trucks, and motorcycles) and nonroad emission categories. 

Because of the significant contribution of nonroad emission sources to the total mobile source

emission inventory, it has become critical over the past several years for the EPA to provide state

and local pollution control agencies with the ability to easily create and project accurate,

reproducible inventories of nonroad emissions to satisfy the specific requirements of the Clean

Air Act Amendments of 1990.

Nonroad emissions result from the use of fuel in a diverse collection of vehicles and equipment,

including vehicles and equipment in the following categories:

• recreational vehicles, such as all-terrain vehicles and off-road motorcycles;

• logging equipment, such as chain saws;

• agricultural equipment, such as tractors;

• construction equipment, such as graders and back hoes;

• industrial equipment, such as fork lifts and sweepers;

• residential and commercial lawn and garden equipment, such as leaf and snow blowers;

• recreational and commercial marine vessels, such as power boats and oil tankers;

• locomotive equipment, such as train engines; and

• aircraft, such as jets and prop planes.

With the exception of aircraft, all categories of nonroad vehicles and equipment were

unregulated by the EPA prior to the mid-1990s.

In a report issued by the EPA in 19911

, the agency reported that nonroad vehicles and equipment

were a significant source of VOC, NOx , and PM emissions. The report showed that in some 
December 2002

EPA NONROAD Emissions Model User’s Guide 1-2

areas of the country, nonroad emissions contributed to as much as a third of the total mobile

source NOx and VOC inventory and over two-thirds of the mobile source PM inventory. 

To assist states and local regulatory agencies in the creation of accurate nonroad emission

inventories, the EPA has developed a nonroad emissions model which covers all areas of the

nation. This document describes the 2002 limited release version of the model.

OVERVIEW OF THE EPA NONROAD EMISSIONS MODEL

Equipment Types

This version of the nonroad emissions model predicts emissions for all nonroad equipment

categories listed above with the exception of commercial marine, locomotive, and aircraft

emissions. The model includes more than 80 basic and 260 specific types of nonroad equipment,

and further stratifies equipment types by horsepower rating. Fuel types include gasoline, diesel,

compressed natural gas (CNG), and liquefied petroleum gas (LPG). 

Pollutants Reported

The NONROAD model estimates emissions for six exhaust pollutants: hydrocarbons (HC), NOX,

carbon monoxide (CO), carbon dioxide (CO2), sulfur oxides (SOX), and PM. The user selects

among five different types for reporting HC — as total hydrocarbons (THC), total organic gases

(TOG), non-methane organic gases (NMOG), non-methane hydrocarbons (NMHC), or volatile

organic compounds (VOC). Particulate matter can be reported as PM of 10 or less (PM10) or

PM of 2.5 or less (PM2.5). The model also estimates emissions of non-exhaust HC for four

modes — diurnal, refueling spillage, vapor displacement, and crankcase emissions. All

emissions are reported as short tons (i.e., 2000 lbs).

Geographic and Temporal Coverage

In each run of the model, the user selects what geographic area(s) are to be included. At the

broadest level, the model estimates national total emissions. More commonly users will specify

emissions by state, or for one or more counties within a state. At the most detailed level, the user

can estimate sub-county emissions; however, this is an advanced feature and the user must

supply sub-county input data. Thus the model is capable of estimating emissions for

nonattainment areas which may consist of multiple counties or sub-counties in one or more

states.
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EPA NONROAD Emissions Model User’s Guide 1-3

The NONROAD model can estimate current year emissions for the specified geographic area as

well as project future year emissions and backcast past year emissions for calendar years 1970

through 2050. In estimating future year projections and in backcasting, the model includes

growth and scrappage rates for equipment in addition to a variety of control program options. 

The model can calculate emissions for a variety of time periods — an entire year, one of four

seasons, or any particular month. Emissions for the period selected are estimated either for the

total period or for a typical day (weekday or weekend) in that period.

Model Components

As shown in Figure 1-1, the NONROAD model consists of three separate components: a

graphical user interface written in Visual Basic, the core model written in Fortran, and a

reporting utility written in Microsoft ACCESS. The install utility supplied easily installs all

three components of the model onto a personal computer. 

The primary purpose of the user interface is to provide the user with an easy method to specify

the options for a model run. With simple Windows-type screens and pull-down menus, the user

can quickly set up, execute, and view a modeling scenario. Once the model options are specified,

the user can then run the Fortran core model from within the interface, and then can move

directly to the reporting utility to view and summarize the modeling results.

The core model of NONROAD, written in Fortran, contains all of the algorithms used by the

model for calculating emissions estimates. The core model can be operated as a stand-alone

application; however, as a stand-alone application it requires some basic knowledge of the DOS

operating system. Also, note that while the user interface runs the core model for one specified

set of conditions, it cannot run multiple runs in batch mode. Multiple runs can be performed by

creating and running a batch file in DOS or in a DOS window in a Windows 3.1 or 95

environment.

The reporting utility, written using Microsoft’s ACCESS database software, is used to create

standardized reports using output data generated in the core model. Like the graphical user

interface, the reporting utility is a fully operational Windows program, with pull-down menus,

designed as a separate module in order to take advantage of the many reporting and formatting

options available when using a database application. Although the reporting utility is written in

ACCESS, it is a stand-alone application, and you do not need to know how to use ACCESS to

generate reports. 
December 2002

EPA NONROAD Emissions Model User’s Guide 1-4

Figure 1-1. NONROAD MODEL FLOWCHART

GUI: Visual Basic program used

to easily modify core model input

options file, launch the core

model, and open the reporting

utility.

Core Model: Fortran program

which computes nonroad

emissions. Reads numerous data

files and writes ASCII output

files.

RU: Microsoft ACCESS

program with pull down menus to

allow easy reporting of core

model results.
December 2002

EPA NONROAD Emissions Model User’s Guide 1-5

The reporting utility provides the user with the following standard reports: 

• Emissions Totals by County

• Emissions Totals by Equipment Type

• Emissions Totals by Horsepower

• Emissions Totals by SCC (source category code)

• Emissions Totals by Source Classification and Horsepower

• Emissions Totals by Source Classification

• Population and Fuel Consumption by SCC

• Population and Fuel Consumption by Source Classification and Horsepower

For most reports, emissions can be reported for either all counties or for a single, user-specified

county and for all fuels or for a single user-specified fuel type. Reports that include emissions

estimates by equipment types or by SCC are separated by major source classification (e.g.,

agricultural, lawn and garden), with subtotals provided for each classification. For those reports,

equipment type descriptions are also included (e.g., “2-wheel tractors”, “asphalt pavers”, etc.). 

Where appropriate, reports also include a grand total by pollutant.

In addition to generating and viewing standardized reports from single model runs, the reporting

utility provides the user the ability to compare the results of two separate model runs. The

current version of the reporting utility has standardized reports for comparing two model runs by

• Emissions Totals by SCC,

• Emissions Totals by Source Classification,

• Emissions Totals by Horsepower and Source Classification, and

• Population and Fuel Consumption by SCC.

For the emissions totals comparisons, the report displays the results of the two model runs, and

the absolute and percent difference between the two model runs. For the population and fuel

comparisons, the report displays only the results of the two model runs side by side. The

comparison reports are useful, for example, to compare emissions from present and future year

projections, or to compare emissions with two different future year control programs.

Model Inputs

The NONROAD model estimates emissions for each specific type of nonroad equipment by

multiplying the following input data estimates:

• Equipment population for base year (or base year population grown to a future year),

distributed by age, power, fuel type, and application;

• Average load factor expressed as average fraction of available power ;
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EPA NONROAD Emissions Model User’s Guide 1-6

• Available power in horsepower; 

• Activity in hours of use per year; and

• Emission factor with deterioration and/or new standards.

The emissions are then temporally and geographically allocated using appropriate allocation

factors.

There are several input files that provide necessary information to calculate and allocate

emissions estimates. These input files correspond to the basic data needed to provide the

calculations: emission factors, base year equipment population, activity, load factor, average

lifetime, scrappage function, growth estimates, and geographic and temporal allocation. Default

values are provided for all input files. The user can replace the default data files when better

information becomes available, either from EPA for national defaults or from local sources for

locality-specific data. The input files are also modifiable to test control strategies. 

Output Options

Output from the core model is an ASCII file, which can be imported directly into the reporting

utility by simply specifying the file name. The reporting utility can then be used to generate the

standardized reports; users with ACCESS can generate their own reports or query the emissions

estimates and other output from the model. The ASCII file can also easily be imported into an

Excel or Lotus spreadsheet for those users who prefer spreadsheet applications, or wish to

generate graphs of model output. In addition, the reporting utility has a feature that allows users

to easily output an Excel file of data in a tabulated report; Excel can then be used to graph the

tabled results.

Lastly, the user also has the option to generate an Emission Pre-Processor System 2 (EPS-2)

input file. EPS-2 is a program, available on EPA’s Web site or bulletin board, that can take the

county-level output from the NONROAD core model and create gridded emissions files ready for

input to the Urban Airshed Model (UAM), a photochemical grid model.
December 2002

EPA NONROAD Emissions Model User’s Guide 1-7

TECHNICAL DOCUMENTATION

Technical documentation of the default model inputs may be found at the EPA's Office of Mobile

Sources (OMS) web site for nonroad modeling:

http://www.epa.gov/otaq/nonrdmdl.htm

The documents can be downloaded as either Adobe Acrobat PDF files or as WordPerfect files. 

If you obtained the model from a CD-ROM rather than downloading it from the web site, the

technical documents are included on the CD-ROM. 

As of the release date for this version of the model, the following technical documents are

available:

• Weekday and Weekend Day Temporal Allocation of Activity in the NONROAD Model

(NR-015)

• Geographic Allocation of State Level Nonroad Engine Population Data to the County

Level (NR-014b)

• Emission Deterioration Factors For Spark-Ignition (NR-011a)

• Refueling Emissions for Nonroad Engine Modeling (NR-013a)

• Average Life, Annual Activity, and Load Factor Values (NR-005b)

• Nonroad Engine Population Estimates (NR-006b)

• Exhaust Emission Factors -- Compression-Ignition (NR-009b)

• Exhaust Emission Factors -- Spark-Ignition (NR-010c)

• Nonroad Engine Growth Estimates (NR-008b) 

• Calculation of Age Distributions -- Growth and Scrappage (NR-007a)

• Basic Evaporative and Crankcase Emission Rates (NR-012a)

• Seasonal and Monthly Activity Allocation Fractions (NR-004)

• HC Conversion Factors: VOC/TOG/ROG/etc (NR-002)

• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines

(NR-003)

• RVP and Temperature Corrections (NR-001a)

Any additional technical documents will be posted on the web site when they are completed. 

Also currently available on the web site are numerous review documents, papers, and

presentation materials.

For answers to specific questions on the NONROAD model and model inputs, or to make

comments or suggestions, email the nonroad inventory model team at:

 nonroad@epa.gov 

FUTURE MODEL UPDATES
December 2002

EPA NONROAD Emissions Model User’s Guide 1-8

The EPA NONROAD modeling team is very interested in receiving comments on this version of

the model and suggestions for future model revisions and enhancements. E-mail your comments

and suggestions to the team at nonroad@epa.gov 

All updates to the model will be announced on and available from the OTAQ nonroad modeling

web site.

TO STAY INFORMED 

For the latest news on the NONROAD inventory model, subscribe to EPA-MOBILENEWS.

EPA will use this listserver as the primary means of communication on the NONROAD model to

distribute technical memos for review, to answer commonly asked questions, and to announce

future model updates. The list is also used for EPA's other mobile source inventory models, so if

you use the MOBILE series of models, you may already be a subscriber. 

To subscribe to the EPA-MOBILENEWS listserver, send the following message to the EPA

Listserver address:

 subscribe EPA-MOBILENEWS FIRSTNAME LASTNAME

where FIRSTNAME and LASTNAME is your name (for example: subscribe epa-mobilenews

George Jetson). The listserver email address is:

 listserver@unixmail.rtpnc.epa.gov

Your email address will then be added to the list of subscribers and a confirmation message will

be sent to your email address. Whenever EPA posts a message to the listserver, a copy of that

message will be sent to all subscribers.

CONVENTIONS USED IN THE USER’S GUIDE

The following conventions are used in this User's Guide:

• “Click” when used in reference to commands means to carry out the command by

clicking it with the left button on the mouse or using keyboard equivalents -- for example,

the Enter key used in place of the Enter command.

• “Enter OK” means to click the OK button with the mouse or press the Enter key to carry

out the action.
December 2002

EPA NONROAD Emissions Model User’s Guide 1-9

• A dialog box option is enabled when its button contains a black dot. The absence of a

black dot means the option is disabled.

• Key strokes are printed in bold and bracketed. For example <R> means to press the R

key on the keyboard.

• Carrying out commands or procedures with keys frequently involves pressing two or

more keys together. For example, <Alt-F> means to hold down the Alt key while

simultaneously pressing F.

• “Arrow keys” or “Cursor keys” are collective terms for the Up, Down, Left, and Right

arrow keys.

• A selection from a windows menu bar is illustrated by bold type and the full name of the

pull-down menu. For example, Reports from the Reporting Utility menu bar. To

demonstrate the selection of an item in a pull-down menu both the main menu selection

and the submenu selection are in bold type connected with a “”. For example, Reports

 Emission Totals by SCC, indicates you should pull-down the Reports submenu and

select the Emission Totals by SCC report.

• Files names are italicized. For example, the default option file provided with the

NONROAD model is template.opt.

Both the Graphical User Interface and the Reporting Utility are standard WINDOWS

applications. They use pull-down menus, dialog boxes, and message boxes. This document

assumes that an individual setting up and running the NONROAD model has experience in a

Windows environment. If you find yourself bogged down in either the graphical user interface or

the reporting utility perhaps you would benefit from one of the many books available that discuss

in great detail the windows environment.

A very brief summary of pull-down menus follows using the example Reports  Emission

Totals by SCC from the Reporting Utility:
December 2002

EPA NONROAD Emissions Model User’s Guide 1-10

Note: For reference, each chapter begins with

a “Quick Start” section that summarizes the

steps explained in the chapter. The chapters

then continue with a more detailed guide to

the model. As the detailed descriptions

include some important notes on the proper

use of the model, we recommend that you

read the chapters completely before using the

model for any official purposes.

You can activate the Reports submenu using the mouse or with keyboard strokes. With the

mouse, you move the mouse pointer over Reports and click with the left mouse button. This

displays the reports submenu list. To select an item from the pull-down list click on the item

with the left mouse button. You can also click on the Reports menu and then drag the mouse

to the item of interest (Emission Totals by SCC) while holding down the left mouse button. 

When you release the button the item is selected.

Alternatively, using the keyboard you can activate the Reports submenu by typing <Alt-R>,

where R is the underlined character of the menu selection (usually the first character of the

word if there are no conflicts). You can also use the arrow keys to move to a different menu

selection or within the submenu list. To select a pull-down menu option type the underlined

letter in the item name. For the above example, <S> will select the Emissions Totals by SCC

report.

ORGANIZATION OF THE USER’S GUIDE

To assist you in the set-up and operation of the

nonroad emissions model, this document

guides you in the process of installing the

model, provides information on system

requirements to operate the model, and

provides detailed information on each

component of the model. In addition, a chapter

is provided to assist you on more advanced

topics.

The user’s guide is organized in the following

manner:

Chapter 2 - Getting Started: This chapter provides information on model hardware and

software requirements. In addition, instructions are provided on installing the model on the

your computer.

Chapter 3 - Graphical User Interface: This chapter discusses the graphical user interface

in detail, and how to specify and change model inputs for most model runs.

Chapter 4 - The Core Model: This chapter describes how to edit options using a text editor

and how to run the core model. Step by step examples are provided.

Chapter 5 - Reporting Utility: This chapter describes the reporting utility and provides you

with information on how to import data from a model run and generate standardized reports.
December 2002

EPA NONROAD Emissions Model User’s Guide 1-11

Chapter 6 - Advanced Topics - This chapter provides detailed information to assist more

advanced users of the model. This detailed information includes:

• a description of the core model inputs;

• a description of required and optional input file packets;

• how to incorporate local data by editing input tables;

• how to perform additional model runs by editing input tables;

• a description of core model output options, such as the generation of EPS-2 input files

and the creation of spreadsheet files; and 

• how to model more advanced scenarios.

Chapter 7 - Trouble Shooting - This chapter describes possible solutions to troubles you

may have running the model.

Several appendices are included that document FIPS and SCC codes used by the NONROAD

model and provide examples of reporting utility standardized reports.
December 2002

EPA NONROAD Emissions Model User’s Guide 2-1

Chapter 2 Getting Started

In this chapter of the User’s Guide, the following topics are discussed:

• the minimum system requirements for installing and running the model; and

• the steps involved in installing the NONROAD model on your computer.

QUICK START

The process of installing the NONROAD model on your computer is quite simple; there is only

one file required for installation, and it works for Windows 3.1, 95, 98, 2000, and NT. It is

named setup.exe, and it is included on the NONROAD CD-ROM or can be downloaded from the

nonroad modeling web site. In addition, the CD includes electronic copies of this NONROAD

User’s Guide, all currently available technical reports, and the source code for the FORTRAN

core model.

In brief, the steps involved in installing and setting up the NONROAD model are as follows (in

this example drive D is used for the CD drive and you should substitute the appropriate letter for

the CD drive on your system):

1. Insert the NONROAD CD-ROM in drive D.

Windows 3.1: File  Run and then type d:\setup.exe

Windows 95, 98, 2000, NT: Start  Run and then type d:\setup.exe

2. The NONROAD model installation program will prompt you for information as

required during the installation process. Once you have supplied the necessary

information, the program will install the NONROAD model on your computer. When

the process is complete, a message box will appear indicating that the installation was

completed successfully.

SYSTEM REQUIREMENTS FOR RUNNING THE NONROAD MODEL

The following are the minimum system requirements for running the NONROAD model:

• Processor 486

• RAM 8 megabytes

• Drive CD-ROM (or access by network)

• Operating System Windows 3.1, Windows 95, or Windows NT

• Mouse
December 2002

EPA NONROAD Emissions Model User’s Guide 2-2

It is recommended that you have at least 30 megabytes of free disk space for installation of the

NONROAD model. The installation itself requires approximately 25 megabytes of disk space,

and additional disk space is needed for the output files that are generated when running the

model and for importing those output files into the reporting utility. The 25 megabytes of

installed files consist of approximately 1 megabyte for the core model, 10 megabytes for the data

files, 10 megabytes for the reporting utility, and 4 megabytes for the graphical user interface. 

INSTALLING THE NONROAD MODEL

To install the NONROAD model, follow these steps:

1. Insert the NONROAD CD-ROM in drive D (substitute the appropriate letter for the

CD drive on your system).

2. Begin the installation procedure.

Windows 3.1: Specify File  Run and enter d:\setup.exe. Specify OK.

Windows 95, 98, 2000, NT: Specify Start  Run and enter d:\setup.exe. 

Specify OK.

3. During the installation process, a number of dialog screens will appear that request

information from you to assist in installing and setting up the program. Once you

have provided all required information, the installation program will set-up a

directory on your computer and copy the necessary files to that directory.

4. The installation program will create a program group on your computer called

Nonroad. This program group will contain icons for four components of the model --

the graphical user interface, the core model, the reporting utility, and the compact

utility. For information on the operation of each of these components, see Chapter 3

(graphical user interface), Chapter 4 (core model), and Chapter 5 (reporting and

compact utilities).

Attaching the Reporting Utility Databases

When the NONROAD model is installed, a subdirectory called Reports is created. Within this

subdirectory are two databases, Nrdata.mdb and Reports.mdb, required to run the reporting

utility. To operate the reporting utility, Reports.mdb must have the path of NRdata.mdb in order

to properly connect to it. This connection is done automatically the first time the Reporting

Utility is opened.

If the Reporting Utility cannot find Nrdata.mdb (for example, the file was moved to another

directory) then a message is displayed. You must attach the tables in order to successfully
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EPA NONROAD Emissions Model User’s Guide 2-3

generate reports. Refer to the section in Chapter 5 titled Attaching the Reporting Utility

Databases.

REINSTALLING THE NONROAD MODEL

The NONROAD model can be completely reinstalled on your computer by following the steps

outlined above. During reinstallation, the program will search for a current installation of the

program. If any current NONROAD files are found, the program will ask you whether you want

to overwrite the files. Indicate Yes or No.
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EPA NONROAD Emissions Model User’s Guide 3-1

Chapter 3 Graphical User Interface

In this chapter of the user’s guide, the following topics are discussed after the Quick Start

description:

• a general description of the graphical user interface,

• moving around in the user interface,

• creating an option file and specifying model parameters,

• running and viewing a model scenario, and

• some advanced options.

QUICK START

The process of setting up an option file that contains a scenario that you are interested in

modeling, and running and viewing the modeling results, is quite simple with the graphical user

interface. Each of the steps involved is discussed in detail in this chapter. In summary, the steps

involved in setting up, running, and viewing a modeling scenario are as follows:

1. Start the Graphical User Interface using the icon created when the EPA NONROAD

Emissions Model was installed on your computer. (For more information, see General

Description below.)

2. Define the parameters that you are interested in modeling. When you first run the

interface, the modeling parameters are contained in the default option file

TEMPLATE.OPT which is automatically read by the interface. Select Scenario on

the main menu. A submenu will appear that contains the various options that you can

specify. These options include the title of your model run, fuel specifications, the

period of time and geographical region over which you want to estimate emissions,

and the source categories that you want to model. (For more information, see the

section below on Creating an Option File.)

3. Save the modified option file, File  Save (or Save As). (For more information,

see the section below on Creating an Option File.)

4. Submit your option file to the core model to run, Model  Run. Once the run has

been completed, a message will appear in a DOS screen notifying you that the run
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EPA NONROAD Emissions Model User’s Guide 3-2

was successful. (For more information, see the section below on Running and

Viewing a Modeling Scenario.)

5. To view the results of this model run, specify Model  Reports. This will move

you to the reporting utility. (For more information, see the section below on Running

and Viewing a Modeling Scenario.)

6. Exit the interface when you are finished with File  Exit. (For more information,

see the section below Exiting the Graphical User Interface.)

GENERAL DESCRIPTION

The NONROAD user interface provides you with an easy method for designing the nonroad

emissions simulations that you are interested in modeling. In addition, the interface provides you

with an easy means for accessing the reporting utility to view the results of your modeling run. 

With simple Windows-type screens and pull-down menus, you can quickly set up, execute, and

view a modeling scenario without any computer programming experience.

When the NONROAD emissions model is installed on your computer, an icon for each

component of the model is created. While this allows you to access each component of the

model individually, through the interface you can operate most of the functions of the EPA

NONROAD Emissions Model -- from the creation of a scenario, to the running of the core

model, to the development of reports -- without exiting one program and executing another.

Note: In this chapter of the user’s guide, information is provided to assist you in setting up an

emissions scenario to model using the default data provided in the model. If you are

interested in modifying the data files to reflect alternatives to the default data, please see

Chapter 6 on Advanced Topics.
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EPA NONROAD Emissions Model User’s Guide 3-3

Figure 3-1:

Graphical User 

Interface icon.

Figure 3-2: Initial graphical user interface screen. 

MOVING AROUND IN THE GRAPHICAL USER INTERFACE

Begin the Graphical User Interface denoted by the icon displayed in Figure 3-1. If your

computer operates with Windows 95, the icon can be found in a program group called

Nonroad Model accessed from the Start menu. If you are operating with Windows 3.1,

the icon can be found through Program Manager.

When launched, the main menu screen of the interface appears (Figure 3-2). The title

bar of the screen displays the NONROAD name followed by the currently opened option file in

parentheses. The default is (template.opt). Below the title bar is the main menu bar, followed by

the EPA banner, and the model run title, message file name, and output file name which are

extracted from the opened option file.

From this screen you can access submenus that make up the graphical interface module, as listed

at the top of the window in the menu bar:

 File - open an existing option file, save a modified option file with the old or a new

name, or exit the interface.
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EPA NONROAD Emissions Model User’s Guide 3-4

• Scenario - define the various parameters that you want in your modeling run.

• Model - run the core model and access the reporting utility.

• Advanced Options - select your own data files to replace the default files provided

with the model and to specify optional output.

• Batch - this option is unavailable. Multiple runs must be done manually.

• Help - general information is provided on the version and status of the model.

Once a main menu item is selected, a list of submenu items will be displayed. The following

shows the list of submenu items for each of the main menu choices:

File Open

Save

Save As

Exit

Scenario Options

Period

Region

Sources

Model Run

Reports

Advanced Options Geographical Allocation

Temporal Allocation

Growth

Equip. Population

Phase In

Emission Factors

Deterioration Factors

Activity

Optional Output

Help Help

About

Current
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EPA NONROAD Emissions Model User’s Guide 3-5

In most instances, after selecting a submenu item a form is displayed for user inputs or selections. 

When an input error occurs, an appropriate message (dialog box) is displayed. If a dialog box

appears, specify OK, make the corrections needed and continue.

CREATING AN OPTION FILE

The first step involved in operating the EPA NONROAD Emissions Model is to setup an option

file which defines the parameters that you are interested in modeling. Once this file has been set

up, it can be submitted directly to the core model from the interface, and then following the

model run the estimated emissions output can be imported into the reporting utility and standard

reports generated.

An option file (*.opt) contains all of the parameters that specify your modeling run. This file is

opened, read, and updated from the interface. To more easily explain the process of setting up an

option file, the following example is provided:

You have been given an assignment to estimate the total emissions from

all lawn and garden equipment in Travis County (Austin), Texas. You

are interested in estimating these emissions for the summertime of 1998.

Throughout this chapter, we will refer to the above example.

Opening and Naming an Option File

When you first run the interface, the default option file TEMPLATE.OPT is automatically opened

and the file name is displayed on the title bar of the main screen. Also displayed in the main

menu screen is the run title, the message file name, and the output file name extracted from the

currently opened option file. You can modify the default option file to define a modeling scenario

of interest. Alternatively, if you want to use or modify a different option file (*.opt) that you

have previously created, follow these steps:

1. From the Main Menu, select File  Open.

2. An open file dialog box appears that requests you to select a new option file. Specify

the option file you are interested in using. This loads the option file into the interface

and updates the main screen.

Before beginning to modify the scenario options in the option file, you should save the option file

with a different name to prevent yourself from accidentally overwriting data in a previously

created option file or in TEMPLATE.OPT. To do this, select File  Save As and indicate the

new file name. For our example, you would specify the file TRAVIS.OPT. The main menu

screen title bar is updated with the new file name. In addition, when you specify a new file name

the message file and output file names are set to the same name as the specified option file with
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EPA NONROAD Emissions Model User’s Guide 3-6

the file name extensions .msg and .out respectively. For our example, you see the files

TRAVIS.MSG and TRAVIS.OUT.

Note: The name of the option file must be no longer than eight characters as a result of DOS

conventions. It is recommended that the extension .OPT be used for all option files.

If the message file specified in the opened option file exists then the button “View Message File”

will appear in the middle of the main menu window. Click on this button to open Windows

Notepad and review the indicated message file.

 

Defining a Report Title

The interface allows you to easily title your model run. This title will be used on any reports you

might generate for this particular scenario.

To provide a descriptive title for your model run, follow these steps:

1. From the main menu select Scenario  Options. 

2. Update the Options screen (Figure 3-3). When the Options screen first appears, it will

contain the title and any options previously defined for this option file. Specify a

descriptive title for your scenario in the field below Title 1. If you want to add a

subtitle, you can do so in the field below Title 2.

3. Specify Done or OK to return to the main menu.

Note: The two title lines of your modeling run must be no longer than 80 characters each. In

addition, the titles should not include single or double quotation marks (i.e., “ or ’), or

periods.
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EPA NONROAD Emissions Model User’s Guide 3-7

Figure 3-3: Options screen.

Defining Fuel Specifications, Ambient Temperatures, and Stage II Control Effectiveness

Nonroad emissions result from the combustion, evaporation, and spillage of fuel in equipment

and vehicles designed primarily for off-road use. The emissions that come from nonroad

equipment and vehicles are dependent, in part, on the composition of the fuel used. Similarly,

the ambient temperature will also affect the emissions from nonroad sources. Finally,

implemented controls act to decrease emissions. As a result, it is important to define the

composition of the fuel, the ambient temperature for the period of time that you are interested in

modeling, and the effectiveness of any existing controls.

The minimum temperature that you define for your modeling scenario is the average low for the

time period selected. For example, when modeling a typical summer day, the minimum

temperature should be the average low temperature in Fahrenheit for the summer season. 

Moreover, when modeling an entire year, the minimum temperature should be the average daily

low for the year and not the lowest temperature ever recorded. Other modeling parameters, such

as RVP, sulfur, and oxygen content, depend on local fuel characteristics. Data for an area should

be available from the state or local air agency.

Stage II controls are designed to reduce emissions during refueling due to vapor displacement. 

They are generally mounted on the pumps at gasoline stations. With regards to nonroad
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2

 Altitude adjustment is not in this version of the model. Hence, this selection is currently disabled in the user

interface.

EPA NONROAD Emissions Model User’s Guide 3-8

equipment, their benefits only apply to equipment that are refueled directly via the pumps (rather

than with refuel tanks). Where present, the effectiveness of this control is also affected by the

design of the filler opening of the equipment. 

Note: EPA currently has no data on the effectiveness of Stage II for nonroad equipment. 

The value should be left at 0% unless local data exist on which a value can be based.

To specify fuel characteristics, temperature, and Stage II control effectiveness, follow these

steps:

1. From the main menu select Scenario  Options.

2. Modify the required parameters. For our example, indicate the gasoline specifications

and ambient temperatures that will be in effect in Travis County during the summer of

1998. Next, identify whether the modeling region is at high or low altitude2. High

should be specified where the average altitude is greater than 5000 feet; this is

consistent with the MOBILE program.

3. Specify Done or OK to return to the main menu.

The acceptable range of values for each of the fuel specification and ambient temperature

options are as follows:

Parameter Minimum Maximum

Fuel RVP (psi) 616

Oxygen (wt.%) 0 5

Fuel Sulfur (wt %) 0 0.5

Temperature (F) -40 120

Stage II control

effectiveness (%)

0 100

Note: The percent effectiveness value must be followed by a decimal point.
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EPA NONROAD Emissions Model User’s Guide 3-9

Figure 3-4: Period screen.

Defining the Modeling Period

The modeling period is simply the period of time for which you want to estimate emissions. To

define the modeling period, follow these steps:

1. From the main menu select Scenario  Period.

2. Indicate the modeling period of interest in the displayed screen (Figure 3-4). 

The interface makes it easy to define the modeling period through a series of select

buttons. The following options are available to you:

• Year - You can define any year between 1970 and 2050 that you are interested

in modeling.

• Period - You can define the modeling period as annual, monthly, or seasonal.

• Month - If you select the modeling period to be monthly, the list of months

will become active and you can select the appropriate month of the year.
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EPA NONROAD Emissions Model User’s Guide 3-10

• Season - If you select the modeling period to be seasonal, the list of seasons

will become active and you can select the appropriate season of the year.

• Type - For any period that you select, you can estimate the emissions as the

total for a 24-hour period (typical day) or for the total period.

• Day - If you select the type to be a typical day, days will become active and

you can select a weekday or weekend day.

Note: While the model allows you to define any model year from 1970 to 2050, it actually

forecasts and backcasts based primarily on 1998 data. For this reason, its estimates

become less accurate as you move further into the past or the future.

Since we are interested in estimating the total emissions during the summertime of

1998 in our example specify Seasonal (under Period), Summer (under Season),

Period Total (under Type), and type in 1998 in the year field.

3. Specify Done or OK to return to the main menu.

Defining the Modeling Region

The interface makes it relatively easy to define the geographical region -- from one county to

multiple counties to an entire state or the nation -- that you are interested in modeling. To do

this, follow these steps:

1. Specify Scenario  Region. The Region screen will appear (Figure 3-5).

2. The first step in defining the modeling region is to remove any regions that have been

specified in a previous scenario that are not applicable to the current scenario. To do

this, highlight the regions in the Current selection list and click on Del.
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EPA NONROAD Emissions Model User’s Guide 3-11

Figure 3-5: Region screen.

3. Specify a region. Several options are available, the methods for selecting them are as

follows:

• 50 States - This option selects all 50 states, you will obtain the state totals for all

50 states individually. When selected, the “Current selection” list is cleared, as no

individual states or counties need be specified.

Tip: Since selecting 50 States as a region clears the current selection list this is a quick and

easy way to delete all of specified states or counties before starting a new region

definition.

• State - This option allows you to select any one, or multiple, of the 50 states. 

When a state is selected, the model will compute total emissions for the entire

state, but will not allocate emissions among counties in the state. Specify State

(under region), scroll through the list of states or type the first letter to jump in the

list. Once found, highlight the state and then Add. The state will appear in the

current selection field.

• County - This option allows you to select one or more counties. To select an

individual county, specify County (under region) and highlight the state of

interest. When you highlight the state a list of counties for that state will be

displayed. Move through the list of counties until you find the one that you want,
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EPA NONROAD Emissions Model User’s Guide 3-12

highlight the county, and then Add. The county name and state abbreviation are

written to the Current selection list.

To specify all counties within a state, indicate County (under region), highlight the

state of interest, and then Add. The Current selection list will display the state

name (e.g., Michigan) with “All of ...” (e.g., “All of Michigan”). The core model 

will compute emission estimates for all of the counties in the named state.

Note: To create a modeling region that is larger than a single state or county, continue to add

new regions to the list of currently selected regions by repeating the process for selecting

states or counties. For example, if a metropolitan area covered four counties, simply

select the first county and then each additional county one at a time.

• US Total - This option allows you to estimate national total emissions, no state

detail is generated. When selected, the “Current selection” list is cleared, as no

individual states or counties need be specified.

Note: The NONROAD model also allows you to define a sub-county region. However, this

option requires that you provide a significant amount of data beyond that furnished with

the model. For information on how to input this additional data, please see Chapter 6,

Advanced Topics.

For our example scenario, indicate County (under Region), highlight Texas from the

list of states, highlight Travis from the list of counties, and Add.

5. Specify Done or OK to return to the main menu.

Defining Source Categories

The EPA NONROAD Emissions Model allows you to estimate emissions from many different

types of equipment and vehicles. Each source category in the NONROAD model is uniquely

identified with a source category code (SCC), which is a ten-digit number. The first two digits,

22, represent mobile sources. For most categories, the next two digits represent the engine or

fuel type (60, 65, 67, 68, and 70, represent 2-stroke gasoline, 4-stroke gasoline, LPG, CNG, and

diesel respectively). The next three digits represent the segment type (for example, recreational

or construction). And the last three digits represent the kind of equipment (for example, golf

carts or snowmobiles). Refer to Appendix B for a complete list of NONROAD SCCs.

When selecting source categories to process in a NONROAD simulation you can specify ‘global’

source category codes instead of each individual SCC. For example, instead of listing all lawn
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EPA NONROAD Emissions Model User’s Guide 3-13

Figure 3-6: Sources screen.

and garden equipment types individually, when you specify Add segment the SCCs are listed

with the last three digits (equipment type) as zero. It is implied that all equipment types will be

processed.

 To define the source categories that you want to model, follow these steps:

1. From the main menu specify Scenario  Sources. The Sources screen will appear

(Figure 3-6).
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EPA NONROAD Emissions Model User’s Guide 3-14

The following options are available:

• Active - Choose either ‘Selected sources’ to specify a subset of sources to model or

‘All Sources’ which will model all SCCs with valid equipment population data. If

‘All Sources’ is selected then the ability to select specific SCCs is removed (i.e. the

Add buttons become deactivated).

• Fuel - Choose between ‘All Fuels’, ‘Diesel’, or ‘SI’ (spark ignition engines).

• Segment - Choose one of the segments listed.

• List of selected sources - Each selected SCC and a brief description is displayed in

the lower portion of the window.

• Add Segment - The SCCs which represent the specified segment and fuel type will

be added to the list of selected SCCs.

• Add Equipment - The SCCs which represent the specified equipment within a

segment will be added to the list of selected SCCs.

• OK - Return to the main menu.

• Remove Selection - This will remove any highlighted SCCs from the list of selected

sources.

2. Similar to defining a region, you must first remove any source segments or equipment

that you do not want to model. Highlight the segments and/or equipment in the list of

selected sources and specify Remove Selection. Multiple sources may be highlighted

by using the <Shift> or <Control> keys. The <Delete> key may also be used to

remove the highlighted sources from the list of selected sources.

3. Select the fuel type. For our example scenario we are interested in all lawn and

garden equipment so we will specify All fuels.

4. Select the segment type. For our example, we are interested in all lawn and garden

equipment and select Lawn & Garden. 
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EPA NONROAD Emissions Model User’s Guide 3-15

5. Specify Add Segment to add a list of SCCs for the specified segment/fuel to the

current list of selected sources. Alternatively, if you are interested in specific

equipment within a source segment then Add Equipment. All of the equipment that

falls under the specified segment/fuel type will appear in the list of selected sources. 

Highlight the equipment that you do not want to model and remove them from the

selection list (see 2 above).

Note: If you are interested in estimating emissions from more than one segment or fuel type,

add the first segment/fuel type and then continue adding segment/fuel types as desired.

6. When you have finished defining sources, specify OK to return to the main menu.

Saving an Option File

Once you have created an option file by defining all of the parameters that you want, you should

save this file. To do this, follow these steps:

1. From the main menu File  Save.

RUNNING AND VIEWING A MODELING SCENARIO

Once you have set up an option file, the interface allows you to easily submit the option file to

the core model to run. Similarly, the interface allows you to access the reporting utility to view

the results of your run and prepare printed reports.

To submit an option file to the core model, follow these steps:

1. From the Main Menu, specify File Open.

2. Specify the option file you want to model in the open file dialog box. This loads the

option file into the interface and the file name is displayed on the main menu title bar. 

If the option file is already loaded, you can skip steps 1 and 2.

3. From the main menu, specify Model  Run (Figure 3-7).

4. A DOS window will appear. After the run has been completed, a message will appear

notifying you that the run was successful.

If the DOS window disappears after the core model completes and you wish to view

the DOS screen, then you need to change the default 'close on exit' in your Windows
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EPA NONROAD Emissions Model User’s Guide 3-16

Figure 3-7: Model submenu screen.

application. If you are running Windows 3.1, this can be accomplished by using the

PIF Editor (from Windows Main group) to edit the NONROAD.PIF file and disable

the 'Close Window on Exit' box. If you are running Windows NT or Windows 95 and

later versions, right click on the nonroad.exe file name, select Properties, select the

Program tab, and disable the 'Close on exit' box. You will then need to manually

close the DOS window when the core model completes.

5. To return to the interface, press <Enter>.

6. It is important to review the output message file produced by the core model. In

addition to any warning or error messages that are generated during execution the

message file will indicate all of the parameters specified in the option file and all of

the input files used in processing. These should be reviewed in order to verify that the

simulation performed was what you intended. Specify View Message File from the

main menu in order to open Windows Notepad and examine the message file.

7. If you are interested in modeling several scenarios prior to viewing and printing a

report, repeat the above steps for each of your option files.
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EPA NONROAD Emissions Model User’s Guide 3-17

Note: The core model runs in DOS under a windows environment which allows you to

multitask activities while the model is running. However, multitasking may lengthen the

amount of time it takes for the model to run, particularly if you are using a 486 computer

with less than 16 megabytes of RAM. If this describes your computer, you should

consider closing all other applications prior to running the model.

To access the reporting utility, follow these steps:

1. From the main menu, specify Model  Report. Refer to Chapter 5 for a complete

description of the Reporting Utility.

ADVANCED OPTIONS

The Advanced Options menu allows you to specify your own data files to replace the default files

provided with the NONROAD model and to specify alternate output file formats. Each submenu

selection allows you to specify a different file to use. In some cases, more than one file may be

applicable to a selection.

Optional outputs include emissions files in either Emissions Processor System (EPS) AMS or

National Emissions Trend (NET) format. (The latter format is currently unavailable.) These

outputs are generated only if a filename is provided for the desired format. 

If your modeling region is outside the state you specified during the NONROAD model

installation then the default Geographic Allocation and Equipment Population file names will

have to be changed. These files have been provided by state to reduce the size of the files. 

EXAMPLE OF CHANGING GEOGRAPHIC ALLOCATION 

The Geographic Allocation selection allows you to identify the allocation look-up table (the

default is “allocate.xrf”) and allocation data files that you want to use. The allocation look-up

table is an assignment of equipment type to an allocation indicator (e.g., construction equipment

assigned to employees in the construction industry). The allocation files contain the actual

estimates of indicator values (e.g., the actual number of employees in the construction industry

by county and year).

To change the look-up table or allocation data files, follow these steps:

1. From the main menu, select Advanced options Geographic Allocation. The

Geographic Allocation screen is displayed (Figure 3-8).
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EPA NONROAD Emissions Model User’s Guide 3-18

Figure 3-8: Geographic Allocation screen.

2. The first step in defining the geographic allocation data files is to remove any

previous data files. Highlight the current files and Delete one at a time.

3. Click Add to specify a new list of allocation files. An open file dialog box appears

that requests you to select a new allocation file. Locate the directory where the

allocation files are saved (when installed: \nonroad\data\allocate) and specify the data

file that you want. Repeat this until all necessary files have been added.

4. To change a specific allocation file, select that file from the list. Then enter the path

 and name of the new file in the text box directly above the list. Click Replace.

 5. Specify Change Look up to change the allocation look-up table. Again, an open file

dialog box appears that requests you to select a new allocation file (this time with the

extension .xrf). Locate the directory where the allocation files are saved and specify

the data file that you want.

6. Specify Done or OK to return to the main menu.
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EPA NONROAD Emissions Model User’s Guide 3-19

EXITING THE GRAPHICAL USER INTERFACE

To exit the interface, follow these steps:

1. From the main menu, specify File Quit.
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EPA NONROAD Emissions Model User’s Guide 4-1

Chapter 4 Core Model

In this chapter of the user’s guide, the following topics are discussed:

• a general description of the core model,

• the process of modifying an option file and

• running the core model.

QUICK START

The process of modifying an option file and running the core model using data provided in the

NONROAD model is straightforward. In summary, the steps involved in running the core model

with existing data are as follows:

1. Modify the core model input option file. To modify an option file, either use the

graphical user interface as discussed in Chapter 3 or a text editor, such as Microsoft’s

Notepad or WordPad, to access the *.opt file that you are interested in changing. 

Alternatively, you can edit the file through DOS. (For more information, see the

section below on Creating an Option File.)

2. Once you have an option file defining the scenario that you are interested in modeling,

you can run the scenario from the graphical user interface as discussed in Chapter 3,

or from DOS by typing “nonroad (the name of your option file).opt” from the nonroad

directory. (For more information, see the section below on Running the Core Model.)

3. After the model has finished, a message will appear in a DOS window notifying you

of the successful completion of the run or of any errors that have occurred.
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EPA NONROAD Emissions Model User’s Guide 4-2

GENERAL DESCRIPTION

The core NONROAD model contains all of the algorithms used by the model for calculating

emissions estimates. The model includes standard data files and tables that allow you to easily

estimate the emissions from a wide variety of nonroad equipment and vehicles for any region of

the country. The information used by the core model for estimating emissions, including userspecified options, data files, and data tables, are input through an option file.

The core model can be operated as a stand-alone application; however, as a stand-alone

application it requires some basic knowledge of the DOS operating system. In addition, in order

to create/modify an input option file you must be familiar with the use of a text editor. If you

prefer you can easily modify the input option file and access the core model from the GUI

(Graphical User Interface), which is described in detail in Chapter 3.

When the NONROAD model is installed on your computer, a directory for the model is created. 

The standard installation creates the NONROAD directory on the c drive; i.e. c:\Nonroad. The

core model is executed with the file NONROAD.EXE.

Note: In this chapter of the user’s guide, information is provided to assist you in setting up an

emissions scenario and running the model using the default data provided in the model. 

If you are interested in modifying the data files to reflect alternatives to the default data,

please see Chapter 6 on Advanced Topics.

For more technical information on the core model, please refer to the technical support

documents, or the core model source code.

CREATING AN OPTION FILE

Before running the core model, you must define the scenario you are interested in modeling by

creating an option file. All model input files and scenario specific parameters are specified in the

input option file. The information contained in each option file is separated into “packets” based

on common information. For example, all data items related to the period of time for which you

are interested in estimating emissions is grouped in a single packet, as are data files related to the

population of equipment for a modeling region. You can quickly set up an option file specifying

the parameters that are applicable to your modeling scenario using default data.

You can view and modify an option file using a text editor such as Microsoft’s Notepad or

WordPad or by using the DOS command edit. When viewing an option file through a text editor,

the keyword that identifies a packet is surrounded by forward slashes (“/”) and can appear in

upper case, lower case, or mixed case. For example, the packet identifier for all of the data files
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EPA NONROAD Emissions Model User’s Guide 4-3

related to the population of equipment is /POP FILES/. To designate the end, or terminator, of a

packet, the keyword END is used, also surrounded by forward slashes (i.e., /END/).

One convenient aspect resulting from the use of a packet input structure is that packets can

appear in any order in an option file. Furthermore, any type of notes or descriptions that aid in

describing the packet can be placed between the individual packets. When executed, the core

model searches for packet identifiers and reads the data between the identifier and the packet

terminator. All other lines in the file are ignored. The file TEMPLATE.OPT is provided with the

NONROAD model and contains a complete description of the packet parameters and formats.

In a fashion similar to that followed in Chapter 3, the following example is provided to more

easily explain the process of creating and setting up an option file:

You have been given an assignment to estimate the total emissions from

all lawn and garden equipment in Travis County (Austin), Texas. You

are interested in estimating these emissions for the summertime of 1998. 

This example will be referred to throughout this chapter.

To create an option file using a text editor, follow these steps:

1. Start the text editor of your choice. Notepad and WordPad are possibilities.

Note: The use of a word processor such as WordPerfect or Microsoft Word is not

recommended unless you are experienced in dealing with ASCII files in those

applications.

2. Open the option file of interest.

Note: If this is the first option file that you are creating, use TEMPLATE.OPT. The

template.opt file, installed with the model, is initially located in the \nonroad

directory. If you have previously created an option file, you can select any *.opt file

for modification.

3. Save the opened option file with a new name in order to prevent the accidental loss of

data resulting from overwriting an existing file. For our example, save template.opt

file as travis.opt. Figure 4-1 shows a portion of the file template.opt.
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EPA NONROAD Emissions Model User’s Guide 4-4

This is the options file for the NONROAD program.

The data is separated into "packets" based on common

information. Each packet is specified by an

identifier and a terminator. Any notes or descriptions

can be placed between the data packets.

------------------------------------------------------

 PERIOD PACKET 

This is the packet that defines the period for 

which emissions are to be estimated. The order of the

records matter. The selection of certain parameters

will cause some of the record that follow to be ignored.

The order of the records is as follows:

1 - Char 10 - Period type for this simulation.

 Valid responses are: ANNUAL, SEASONAL, and MONTHLY

2 - Char 10 - Type of inventory produced.

 Valid responses are: TYPICAL DAY and PERIOD TOTAL

3 - Integer - year of episode (4 digit year)

4 - Char 10 - Month of episode (use complete name of month)

5 - Char 10 - Type of day

 Valid responses are: WEEKDAY and WEEKEND

------------------------------------------------------

/PERIOD/

Period type : Annual

Summation type : Period Total

Year of episode : 1996

Season of year : 

Month of year : 

Weekday or weekend : 

/END/

Figure 4-1: Portion of the TEMPLATE.OPT file.

4. Modify the option file. For our modeling example, we want to modify travis.opt by

specifying the parameters required to estimate summertime emissions in 1998 from

lawn and garden engines in Travis County, Texas.

For a simple modeling run, using the data provided with the model, five packets of information

will most frequently be modified. These five packets are the /RUNFILES/, /OPTIONS/,

/PERIOD/, /REGION/, and /SOURCE CATEGORY/ packets which are described in the

following sections. In addition, the /POP FILES/ and /ALLOC FILES/ packets will be modified

if the region is changed to another state.

Modifying /RUNFILES/

In the /RUNFILES/ packet, some of the data files read by the model are defined. The first 20

characters of each line contains the keyword(s) which identify the kind of file specified. For our

simple example, we are only interested in changing the name of the message file and the output

data file. In Figure 4-2, the message and output data files have been changed (travis.*).
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EPA NONROAD Emissions Model User’s Guide 4-5

This is the packet that lists the names of output files

 and some of the input data files read by the model. If

 a drive:\path\ is not given, the location of the 

 NONROAD.EXE file itself is assumed. You will probably

 want to change the names of the Output and Message files

 to match that of the OPTion file, e.g., MICH-97.OPT,

 MICH-97.OUT, MICH-97.MSG, and if used MICH-97.AMS.

------------------------------------------------------

/RUNFILES/

ALLOC XREF : c:\nonroad\data\allocate\allocate.xrf

ACTIVITY : c:\nonroad\data\activity\activity.dat

TECHNOLOGY : c:\nonroad\data\tech\tech.dat

SEASONALITY : c:\nonroad\data\season\season.dat

REGIONS : c:\nonroad\data\season\season.dat

MESSAGE : travis.msg

OUTPUT DATA : travis.out

EPS2 AMS :

/END

Figure 4-2: TRAVIS.OPT /RUNFILES/ packet.

Note: The core model creates two output files. The first is a message file (*.msg) that can be

read with a text editor or through DOS and identifies relevant information on the model

run such as time and date of the run, files processed, and any error or warnings which

occurred during the run. The second is a data file (*.out) that can be opened and viewed

in the reporting utility.

To do this, follow these steps:

1. Locate the /RUNFILES/ packet in travis.opt.

2. Move to the “Message file”. Type in the name that you want to call the new message

file (in our example travis.msg).

3. Move to the “Output data file”. Type in the name that you want to call the new

output file (in our example, travis.out). 

Modifying /OPTIONS/

The options packet, /OPTIONS/, defines some of the parameters that make episode-specific

emission factor adjustments. These options include fuel specifications that will be in effect

during the modeling period and ambient temperatures that are typical during the same period. In

addition, you can define the title that describes your modeling scenario and which will appear on

your model reports.
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EPA NONROAD Emissions Model User’s Guide 4-6

The order of the records is fixed. The order is as follows:

1 - Char 80: First title on reports

2 - Char 80: Second title on reports

3 - Real 10: Fuel RVP of gasoline for this simulation

4 - Real 10: Oxygen weight percent of gasoline for simulation

5 - Real 10: Percent sulfur for gasoline

6 - Real 10: Percent sulfur for diesel

7 - Real 10: Percent sulfur for LPG/CNG

8 - Real 10: Minimum daily temperature (deg. F)

9 - Real 10: Maximum daily temperature (deg. F)

10 - Real 10: Representative average daily temperature (deg. F)

11 - Char 10: Flag to determine if region is high altitude (LOW or HIGH)

The acceptable range of values for each of the fuel specification and ambient temperature options

are as follows:

Fuel RVP 6 to 16

Oxygen (wt.%) 0 to 5

Fuel Sulfur (%) 0 to 0.5

Temperature (°F) -40 to 120

Altitude* Low or High (Specify high where average

altitude > 5000 ft)

*High altitude adjustments are not included in this version of the model.

The minimum temperature that you define for your modeling scenario is the average low for the

time period selected. For example, when modeling a typical summer day, the minimum

temperature should be the average low temperature in Fahrenheit for the summer season. 

Moreover, when modeling an entire year, the minimum temperature should be the average daily

low for the year and not the lowest temperature ever recorded. Other modeling parameters, such

as RVP, sulfur, and oxygen content, depend on local fuel characteristics. Data for an area should

be available from the state or local air agency.

To modify the options packet, follow these steps:
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EPA NONROAD Emissions Model User’s Guide 4-7

1. Locate the /OPTIONS/ packet.

2. Locate Title 1. Type in a description of your scenario. If you are interested in adding

a subtitle, type that on the line Title 2. If you do not want a title to appear on your

report, leave these fields blank.

3. For the remaining information in the /OPTIONS/ packet, change any existing

information that is relevant for your run. Figure 4-3 shows the /OPTIONS/ packet

with modifications for our model example.

------------------------------------------------------

1 - Char 80 - First title on reports

2 - Char 80 - Second title on reports

3 - Real 10 - Fuel RVP of gasoline for this simulation

4 - Real 10 - Oxygen weight percent of gasoline for simulation

5 - Real 10 - Percent sulfur for gasoline

6 - Real 10 - Percent sulfur for diesel

7 - Real 10 - Percent sulfur for LPG/CNG

8 - Real 10 - Minimum daily temperature (deg. F)

9 - Real 10 - maximum daily temperature (deg. F)

10 - Real 10 - Representative average daily temperature (deg. F)

11 - Char 10 - Flag to determine if region is high altitude

 Valid responses are: HIGH and LOW

12 - Char 10 - Flag to determine if RFG adjustments are made

 Valid responses are: YES and NO

------------------------------------------------------

/OPTIONS/

Title 1 : Lawn and Garden Equipment

Title 2 : Travis County, Summertime 1998

Fuel RVP for gas : 9.0

Oxygen Weight % : 0.0

Gas sulfur % : 0.034

Diesel sulfur % : 0.33

CNG/LPG sulfur % : 0.003

Minimum temper. (F): 60

Maximum temper. (F): 84

Average temper. (F): 75

Altitude of region : LOW

/END/

Figure 4-3: Modified /OPTIONS/ packet.

Modifying /PERIOD/

The packet /PERIOD/ defines the period of time for which emissions are to be estimated. The

valid responses for the /PERIOD/ packet are as follows:
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EPA NONROAD Emissions Model User’s Guide 4-8

Period type Annual, seasonal, or monthly

Summation Type Typical day or period total

Year of Episode A four-digit year between 1970 and 2050 

Season of year Winter, spring, summer, autumn

Month of year Complete month name

Weekday or Weekend Weekday or Weekend

The season is ignored if the period type is not seasonal. Similarly, the month is ignored if the

period type is not monthly. Also, weekday/weekend is ignored if summation type is period total.

To modify the /PERIOD/ packet, follow these steps:

1. Locate the /PERIOD/ packet.

2. Modify the information that is appropriate for your scenario. Figure 4-4 shows the

/PERIOD/ packet with the changes required for our example. 

1 - Char 10 - Period type for this simulation.

 Valid responses are: ANNUAL, SEASONAL, and MONTHLY

2 - Char 10 - Type of inventory produced.

 Valid responses are: TYPICAL DAY and PERIOD TOTAL

3 - Integer - year of episode (4 digit year)

4 - Char 10 - Month of episode (use complete name of month)

5 - Char 10 - Type of day

 Valid responses are: WEEKDAY and WEEKEND

------------------------------------------------------

/PERIOD/

Period type : seasonal

Summation type : Period Total

Year of episode : 1998

Season of year : Summer

Month of year : 

Weekday or weekend : 

/END/

Figure 4-4: Modified /PERIOD/ packet.
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EPA NONROAD Emissions Model User’s Guide 4-9

Modifying /REGION/

The packet /REGION/ defines the geographic region that you are interested in modeling. In the

NONROAD model, regions are defined by using two types of parameters. The first specifies the

type of region. The acceptable responses for the region level are US TOTAL, 50 STATE,

STATE, COUNTY, and SUBCOUNTY. The second type of parameter identifies the region

codes or FIPS codes to be modeled. You can specify a global FIPS code to indicate an entire

group of counties or states. For example, by entering “06000" as the FIPS code, you are

specifying all of the counties in the State of California. Similarly a FIPS code of “00000"

indicates all states in the United States. The first two pages of FIPS codes used in the model are

listed in Appendix A; an electronic file containing all FIPS codes is contained on the

NONROAD compact disc (file fipslist.asc) and can also be downloaded from the nonroad

modeling web page.

The following table shows how the model’s definition of the modeling region depends on the

combination of the level and FIPS code(s) specified:

Level FIPS Code

US TOTAL The “FIPS code” is ignored and national estimates are

calculated. This run is substantially faster than 50 STATE since

no state detail or allocation is required.

50 STATE The “FIPS code” is ignored and state-level estimates are

calculated for all 50 states.

STATE If a list of specific state FIPS codes is supplied [e.g., 06000 (for

California) and 48000 (for Texas)], state-wide emissions for the

defined states are produced.

COUNTY If the global code for a state is specified (e.g., 06000), countylevel estimates are calculated for all counties within the state. If

a list of specific county FIPS codes is supplied, county-level

estimates for just those counties will be produced. 
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EPA NONROAD Emissions Model User’s Guide 4-10

SUBCOUNTY To estimate subcounty emissions, the codes must be a

combination of a single county FIPS code and a subcounty code. 

For example, if you were interested in modeling the Northwest

portion of Washtenaw County in Michigan, you would combine

the FIPS code for the county (26161) with a subcounty code

(NW) to form the code 26161NW. Estimates for the sub-county

level will be calculated. If this option is specified, appropriate

data for subcounty resolution must also be supplied in the data

files. Refer to the section on Modifying Inputs for Subcounty

Runs in Chapter 6.

To modify the /REGION/ packet, follow these steps:

1. Locate the /REGION/ packet.

2. Remove, add, or change any existing information that is not relevant for your

scenario. For our example, the FIPS code for Travis County, Texas is 48453 (48

designates the State of Texas; 453 is the code for Travis County). Figure 4-5 shows

the /REGION/ packet with the changes required for our example.

US TOTAL - Nothing needs to be specified. The FIPS

 code 00000 is used automatically.

50STATE - Nothing needs to be specified. The FIPS

 code 00000 is used automatically.

STATE - state FIPS codes

COUNTY - state or county FIPS codes. State FIPS

 code means include all counties in the 

 state.

SUBCOUNTY - county FIPS code and subregion code.

------------------------------------------------------

/REGION/

Region Level :COUNTY

 :48453

/END/

------------------------------------------------------

Figure 4-5: Modified /REGION/ packet.
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EPA NONROAD Emissions Model User’s Guide 4-11

Modifying /SOURCE CATEGORY/

The packet /SOURCE CATEGORY/ tells the model which source category codes (SCC) are to

be processed. This is an optional packet. If the /SOURCE CATEGORY/ packet is omitted, all

SCCs are processed. If you would like to model only a subset of equipment types then include

the packet and your preferred list of SCCs. Running the model with only the desired equipment

types can reduce model run time and help focus reports on data of particular interest.

Tip: Some packets in the core model, such as /SOURCE CATEGORY/, are optional and can

be removed from processing by simply placing any non-blank character in the first

column of the line containing the packet identifier. For example, if you wanted to

“comment out” the /SOURCE CATEGORY/ packet, the first column of the packet could

look like this: ,/SOURCE CATEGORY/ with the comma (,) as the non-blank character.

Each source category in the NONROAD model is uniquely identified with a source category

code (SCC), which is a ten-digit number. The first two digits, 22, represent mobile sources. For

most categories, the next two digits represent the engine or fuel type (60, 65, 67, 68, and 70,

represent 2-stroke gasoline, 4-stroke gasoline, LPG, CNG, and diesel respectively). The next

three digits represent the segment type (for example, recreational or construction). And the last

three digits represent the kind of equipment (for example, golf carts or snowmobiles). For our

example, the SCCs for lawn and garden equipment are 22xx004000, where xx = 60, 65, 67, 68,

and 70, ‘004' signifies lawn and garden, and ‘000' indicates all types of equipment in the lawn

and garden category. The SCC 2265000000 refers to all 4-stroke gasoline sources. Refer to

Appendix B for a complete list of NONROAD SCCs. 

To modify the /SOURCE CATEGORY/ packet, follow these steps.

1. Locate the /SOURCE CATEGORY/ packet.

2. Remove or change any existing information that is not relevant for your scenario

(Figure 4-6).
December 2002

EPA NONROAD Emissions Model User’s Guide 4-12

 SOURCE CATEGORY PACKET

This packet is used to tell the model which source

categories are to be processed. It is optional.

If used, only those source categories list will

appear in the output data file. If the packet is

not found, the model will process all source 

categories in the population files.

------------------------------------------------------

/SOURCE CATEGORY/

 :2260004010

 :2265004010

 :2267004010

 :2268004010

 :2270004010

/END/

Figure 4-6: Modified /SOURCE CATEGORY/ packet.

Modifying the /POP FILES/ and /ALLOC FILES/ Packet

In the NONROAD model, there are several packets found in an option file that list the names of

files that contain data used by the model to estimate emissions. To make these data files more

manageable, some of the data is separated into files by state. In most cases, these files do not

require any modifications if you are running the model with the default data provided.

When you modify the /REGION/ packet, specifying a different or additional state to model, then

two types of data files may be affected by this modification. These two types of files are the

population data files and the allocation data files and are located in the /POP FILES/ packet and

the /ALLOC FILES/ packet, respectively. The /POP FILES/ packet defines the equipment

population files read by the model. You can identify any number of files for a run; typically each

file represents one state. The /ALLOC FILES/ packet defines the spatial allocation files read by

the model. These files contain the surrogate indicators typically used to allocate from the statelevel to county-level. These files are separated by state and by type of allocation indicator.

When you initially install the NONROAD model, you are prompted to identify the state where

you are located. This step sets up the population and allocation factor data files for your state. If

during the process of creating an option file you define a region outside of your originally defined

state, you must change the state identification code of the population and allocation data files to

the new state.
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EPA NONROAD Emissions Model User’s Guide 4-13

To modify the /POP FILES/ packet, follow these steps.

1. Locate the /POP FILES/ packet .

2. Check to see that the population data files contain the name of the state that you are

interested in modeling. If not, modify the name of the population file to identify the

state you want. For our example, the population file should be changed to the file for

the state of Texas, “\NONROAD\DATA\POP\TX.POP”, as shown in Figure 4-7. 

(Since we are only interested in a county in one state in our example, only the

population file for that state is required. If you were interested in multiple states, the

population files for each state would be required.)

Note: Population data files are named using the two character state abbreviation.

------------------------------------------------------

This is the packet that defines the equipment population

files read by the model.

------------------------------------------------------

/POP FILES/

 :c:\nonroad\data\pop\tx.pop

/END/

Figure 4-7: Modified /POP FILES/ packet.

To modify the /ALLOC FILES/ packet, follow these steps:

1. Locate the /ALLOC FILES/ packet.

2. As you can see in Figure 4-8, in addition to being separated by state, the allocation data

files are further stratified by a series of allocation factors. Once you locate /ALLOC

FILES/, check to see that the allocation data files contain the name of the state that you

are interested in modeling. If not, modify the name of the allocation data files to

identify the state you want. For our example, the files containing the allocation data

should be changed to identify the state of Texas.
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EPA NONROAD Emissions Model User’s Guide 4-14

------------------------------------------------------

This is the packet that defines the spatial 

allocation files read by the model.

------------------------------------------------------

/ALLOC FILES/

RV Park employees :c:\nonroad\data\allocate\tx_rvprk.alo

Golf Course estab. :c:\nonroad\data\allocate\tx_golf.alo

Air Transportation :c:\nonroad\data\allocate\tx_airtr.alo

Contruction value :c:\nonroad\data\allocate\tx_const.alo

Havested cropland :c:\nonroad\data\allocate\tx_farms.alo

Wholesale establis.:c:\nonroad\data\allocate\tx_holsl.alo

Family housing :c:\nonroad\data\allocate\tx_house.alo

Logging empl. :c:\nonroad\data\allocate\tx_loggn.alo

Landscape empl. :c:\nonroad\data\allocate\tx_lscap.alo

Manufacturing empl.:c:\nonroad\data\allocate\tx_mnfg.alo

Oil & gas employees:c:\nonroad\data\allocate\tx_oil.alo

Census population :c:\nonroad\data\allocate\tx_pop.alo

Resid. snowblower :c:\nonroad\data\allocate\tx_sbr.alo

Comm. snowblower :c:\nonroad\data\allocate\tx_sbc.alo

Snowmobile :c:\nonroad\data\allocate\tx_snowm.alo

Outboard water :c:\nonroad\data\allocate\tx_wob.alo

Inboard water :c:\nonroad\data\allocate\tx_wib.alo

Coal mining empl. :c:\nonroad\data\allocate\tx_coal.alo

/END/

Figure 4-8: Modified /ALLOC FILES/ packet.

To modify the /STAGE II/ packet, follow these steps:

1. Locate the /STAGE II / packet.

2. Once you locate /STAGE II/, check to see that the percentage reduction in refueling

emissions under Stage II control reflects that of the area you are interested in

modeling. If the area does not have Stage II control at the fuel pump, the effectiveness

should be zero. Otherwise, enter a control effectiveness between 0 and 100 percent. 

Note: A decimal point must be used after the percent effectiveness. 

Note: EPA currently has no data on the effectiveness of Stage II for nonroad equipment. The

value should be left at 0% unless local data exist on which a value can be based.
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EPA NONROAD Emissions Model User’s Guide 4-15

Saving an Option File

After you have completed the modification of an option file to reflect the scenario that you are

interested in modeling, save the file and exit the text editor.

RUNNING THE CORE MODEL

After you have created an option file that defines the scenarios you are interested in modeling, the

process of running the core model is quite simple. In Chapter 3, the steps necessary to run the

core model through the graphical user interface were described. In this chapter, the steps required

to run the core model through a DOS window are described.

To run the core model through a DOS window, follow these steps:

1. Open a DOS window.

2. Change to the Nonroad directory.

3. Type “nonroad (the name of your option file).opt” to run the core model. For

example, if you were interested in running the example option file travis.opt, type 

“nonroad travis.opt”.

4. The model will now run with your option file. The first step that the model goes

through is an initialization. During this step, the core model is reading in the option

and data files and checking to ensure that all data files required to complete the run

are available. After the model has initialized, it will begin the process of calculating

emissions estimates based on the parameters that you set. A line on the screen will

inform you of the progress of your run. When the run has finished, a message will

appear indicating that the run was successfully completed (Figure 4-9).

Note: Most of the errors that may occur during the running of a scenario will occur during the

initialization stage. If an error occurs, a message will appear on the screen notifying you

of the error. Make the appropriate correction and rerun the model.
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EPA NONROAD Emissions Model User’s Guide 4-16

Figure 4-9: DOS window showing successful model run.

5. Review the message file associated with this run. Either type “edit (the name of your

file).msg” or you can open the message file through a Windows text editor.

Error Stop Feature

When an error occurs in the core model, an informative message is displayed in the window and

written to the output message file, and the program stops. In addition to error checking, a number

of conditions are checked that will produce a warning message. Warning messages are meant to

inform you that a condition exists which you may want to review and correct. An example is

“WARNING: Monthly seasonality factors do not add to 1. Renormalizing...” If you have

included new seasonality data and thought it should sum to one, then this message would indicate

either a data format problem or a typo. There are conditions which could produce many warning

messages and still run to completion. In order to avoid this situation, the model will stop if 50 of

the same kind of warning message is generated.
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EPA NONROAD Emissions Model User’s Guide 5-1

Chapter 5 Reporting Utility

In this chapter of the user’s guide, the following topics are discussed:

• a general description of the NONROAD model Reporting Utility,

• how to import core model outputs, 

• the different report types,

• how to generate and view reports, and

• how to compact databases, and how to repair corrupted databases. 

QUICK START

Each step involved in the creation of NONROAD model reports is explained in this chapter. 

However, to quickly create reports and view core model output data, follow these simple steps.

1. Start the reporting utility from the Reports icon created when the NONROAD model

was installed on your computer, or by selecting Model  Reports from the graphical

user interface main menu. (For more information, see General Description below.)

2. Import the core model output file that you are interested in viewing by selecting Data

 Import Data from the main menu of the reporting utility. (For more information,

see Importing Core Model Output below.)

3. Select the report type. From the main menu select Reports  “report name”. Once

you have selected the report that you want, specify the report options. (For more

information, see Report Types and Generating Reports below.)

4. You can print the displayed report by selecting File  Print. (For more information,

see Viewing a Report in Print Preview below.)
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EPA NONROAD Emissions Model User’s Guide 5-2

GENERAL DESCRIPTION

The reporting utility is used to create standardized reports using output data generated in the core

model. Like the graphical user interface, the reporting utility is a fully operational Windows

program designed as a separate module in order to take advantage of the many reporting and

formatting options available when using a database application. Although the reporting utility is

written in Microsoft Access database software, you do not need to know how to use Access to

generate reports. Microsoft Access 2.0 allows users operating Windows 3.1 and Windows 95 to

run the reporting module. If you do not have Access 2.0 (i.e., if you do not have any version of

Access installed on your computer or you are using Access 97 for other database applications), the

reporting utility will operate as a standalone application. 

Warning: If you are using Access 97, do not convert the reporting utility from Access 2.0 to 97. 

The two versions are significantly different and would require major rewriting of the

reporting utility modules. If you want to use Access 97 on the NONROAD reporting

utility tables then make a copy of nrdata.mdb and convert/import the copied database

into Access 97. This will preserve the reporting utility integrity and allow you the

power to create custom reports.

When the NONROAD model is installed on your computer, an icon for the reporting utility is

created. To start the reporting utility, double click on the reporting utility icon. Alternatively,

selecting Model  Reports while running the graphical user interface will also start the

reporting utility.

THE REPORTING UTILITY MENUS

Figure 5-1 shows the initial screen when the reporting utility is executed. From this screen you

can access the pull down menus that make up the reporting utility.

• File - setup and preview a window for printing, print a window, and exit the database.

• Reports - select a standard report for viewing data. 

• Compare - select a report for comparing the results of two separate modeling runs.

• Data - import data, remove a simulation from the database, and reattach files.
December 2002

EPA NONROAD Emissions Model User’s Guide 5-3

Figure 5-1: Initial report utility screen.

Once a main menu item is selected, a list of submenu items will be displayed. The following

shows the list of submenu items for each of the main menu choices:

File Print Setup...

Print Preview

Print...

Exit

Reports Emissions Totals by County

Emissions Totals by Equipment Type

Emissions Totals by Horsepower

Emissions Totals by HP and Source Classification

Emissions Totals by SCC

Emissions Totals by Source Classification

Population and Fuel Consumption by HP and Source Classification

Population and Fuel Consumption by SCC
December 2002

EPA NONROAD Emissions Model User’s Guide 5-4

Compare Compare Two Model Runs by HP and Source Classification

Compare Two Model Runs by Pop and Fuel

Compare Two Model Runs by SCC

Compare Two Model Runs by Source Classification

Data Import Data

Remove Simulation

Re-Attach Tables

Each submenu item opens a window where you must provide additional information. When an

input error occurs, an appropriate message (dialog box) is displayed. Make the corrections

needed, and continue.

IMPORT, DELETE, AND RE-ATTACH

The reporting utility has been designed to run cohesively with the graphical user interface and the

core model to simplify the use of the NONROAD model; if you operate the model with the

default inputs provided, the process of running a simulation and generating reports is

straightforward.

Importing Core Model Output

In order to generate model summary reports, the reporting utility must import the output from the

core model. As discussed in Chapters 3 and 4, the core model output file will have the name you

assigned to it.

Follow these steps to import a core model output data file:

1. From the Main Menu, select Data  Import Data.

2. Specify the core model output file in the open file dialog box.

3. A screen will appear requesting you to enter the new database table name (Figure 5-2). 

Type in the appropriate name of the database table. The database table name that you

enter is the name that the reporting utility will recognize for all further processing of

the data.
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EPA NONROAD Emissions Model User’s Guide 5-5

Figure 5-2: Import core model data screen.

Tip: Because the core model was developed in Fortran, the name of the output file must be no

longer than eight characters with a three character extension as a result of DOS

conventions. The reporting utility allows you to name the database table using up to 30

characters. The name you give the database table can be the same as the output data file

(but without the .extension since a period is not a valid table name character in Access, nor

is the apostrophe). However, to help in differentiating one core model run from others, it

is recommended that a more descriptive name be used.

4. After you have entered a name, Import the data. The bottom of the window will

display a line indicating the percent completion of the import. This process may take

several minutes or longer depending on the size of the database that you are processing

and the speed of your computer. When the import is complete, a message box will

appear indicating that the process is done. Enter OK.

Note: If you enter a name that is invalid (e.g., contains punctuation marks or has already been

used), a message will appear notifying you of the problem and return you to the table name

field. If this happens, simply rename the table and Import again.
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EPA NONROAD Emissions Model User’s Guide 5-6

5. Following the data import and message screen you will be requested to specify another

core model output file in the open file dialog box (Step 2). You can repeat steps 2 - 4

and continue to import core model output files. When you are finished importing files

select Cancel in the open file dialogue box to return to the main menu.

Removing a Simulation

When an imported database table is no longer of use it can be deleted. This should only be done

with the reporting utility submenu option Remove Simulation. In addition to deleting the table,

the reporting utility removes records from tables it uses for processing.

Warning: Simulation tables should never be deleted in the NRdata database except through 

Data  Remove Simulation in the reporting utility.

Follow these steps to delete an imported database table:

1. From the Main Menu, select Data  Remove Simulation.

2. A screen appears allowing you to indicate which table you want to delete. Select the

table name from the available list or type the table name in the field. When you type

the table name it will automatically be expanded to match a name in the list.

3. Specify Remove. When the table has been successfully deleted a message box will

appear indicating that the process is done. Enter OK.

4. Repeat steps 2 and 3 until all database tables you want to delete have been removed. 

Until you return to the main menu, the list of table names will show “#Deleted” for

those tables which you have deleted.

5. Specify Done. The message, “It is advisable to compact Nrdata.mdb through the

Nonroad Compact and Repair Utility after deleting simulations. You can do this after

you close the Reporting Utility.” is displayed. Enter OK.

Tip: Following the removal of database tables, particularly large tables, it is beneficial to

compact the database. Refer to the section Compacting and Repairing Databases at the

end of this chapter for more details.
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EPA NONROAD Emissions Model User’s Guide 5-7

Attaching the Reporting Utility Databases

When the NONROAD model is installed, a subdirectory called Reports is created. Within this

subdirectory are two databases required to run the reporting utility. These databases and the

information contained in each are as follows:

• NRdata.mdb - This database contains the example data supplied with the model and

any core model output data you import.

• Reports.mdb - This database contains the reporting utility code and requisite data

tables (such as the SCC table and FIPs county code).

Warning: The NRdata and Reports databases are essential to run the reporting utility. In

addition, there are two tables in the NRdata database called Table Headers and Table

Counties that also are essential to the operation of the reporting utility. These

databases and tables should never be deleted.

To operate the reporting utility, Reports.mdb must have the path of NRdata.mdb in order to

properly connect to it. The first time the reporting utility is started a screen will be displayed with

the message “Attaching Tables...”. When the Nrdata tables have been successfully attached to the

Reports database a message box will appear indicating that the operation is complete.

If you move the database tables to a new directory you will have to connect Nrdata.mdb to the

Reports database. Follow these steps:

1. Select Data  Re-Attach Tables. 

2. If the databases reside in the same subdirectory as the reporting utility, a message box

will appear indicating that tables were successfully attached. Enter OK. If

NRdata.mdb resides in a different directory than Reports.mdb, an open file dialog box

will appear. Locate the directory where the NRdata.mdb database resides. When

NRdata.mdb is attached, a message box will appear indicating that the operation is

done.
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EPA NONROAD Emissions Model User’s Guide 5-8

REPORT TYPES

The reporting utility provides you with a set of standard reports. With the exception of the first

report listed below, Emissions Totals by County, each of the reports displays the report data for

either all states or counties or for a single, user-specified state or county. In addition, each of the

emissions reports displays emissions for either all fuel types or for a single, user-specified fuel

type. A summary of each of these reports is as follows:

Emissions Totals by County - This report lists emissions by pollutant and county.

Note: If the output file generated in the core model contains data for multiple counties in a state

the Emissions Totals by County report will be reported for all of these counties. If you

want a separate Emissions Totals by County report for each county, then the core model

must be run for each individual county. Once the core model has been run, you must

import the output files and run the Emissions Totals by County using each ‘county’

database table.

Emissions Totals by Equipment Type - This report lists emissions by pollutant for each

equipment type. It is separated by major source classification (e.g., agricultural, lawn &

garden, etc.) with subtotals provided for each classification. Equipment type descriptions

are also included (e.g., “2-wheel tractors”, “asphalt pavers”, etc.). The report includes a

grand total by pollutant.

Emissions Totals by Horsepower - This report lists emissions by pollutant and

horsepower ranges. The report includes total across all horsepower ratings by pollutant.

Emissions Totals by HP and Source Classification - This report lists emissions by

pollutant for each Source Classification and horsepower range. The report is separated by

major equipment classification and subtotals are provided. The report includes a grand

total by pollutant.

Emissions Totals by SCC - This report lists emissions by pollutant for each SCC code. 

The report is separated by major equipment classification and subtotals are provided. In

addition to the SCC code, the equipment description and engine type is provided. The

report includes a grand total by pollutant.

Emissions Totals by Source Classification - This report lists emissions by pollutant for

each major equipment category. The report includes a grand total by pollutant.

Population and Fuel Consumption by HP and Source Classification - This report lists

equipment population and fuel consumption for each fuel type, source classification and

horsepower range. The report is separated by fuel type and major equipment

classification, and subtotals are provided. The report includes a grand total of population.
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EPA NONROAD Emissions Model User’s Guide 5-9

Population and Fuel Consumption by SCC - This report lists equipment population and

fuel consumption for each SCC code. The report is separated by fuel type and major

equipment classification, and subtotals are provided. In addition to the SCC code, the

equipment description and engine type is provided. The report includes a grand total of

population.

Note: Fuel consumption values are output as zero for all CNG and LPG sources.

USER SPECIFICATIONS

To provide flexibility in designing a report, the report utility offers several report options. When

you select a report type, a window appears requesting specific inputs and your choice of display

options. Figure 5-3, used by most of the different report types, sets all of the report options

available. The other windows used to set report options contain a subset of these options.

Note: Because there are different types of hydrocarbon and particulate matter emissions, the

reporting utility is designed to allow you to identify the type of reporting units that you

want. For hydrocarbon emissions, the core model calculates and outputs these emissions

as THC (total hydrocarbon). The reporting utility has the capability to report hydrocarbons

as THC, TOG (total organic gas), NMOG (non-methane organic gas), NMHC (nonmethane hydrocarbon), or VOC (volatile organic compound). THC is converted to the

other designations by applying appropriate factors.

For particulate matter, the core model calculates and outputs these emissions as PM10. The

reporting utility allows you to report particulates as PM10 (particulate size of 10 microns or

less), or PM2.5 (particulate size of 2.5 microns or less). PM10 is converted to PM2.5 by

applying an appropriate factor.
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EPA NONROAD Emissions Model User’s Guide 5-10

Figure 5-3: User-specified report options screen.

A brief description of the report options is provided in the table below.

User-Specified

Report Option Description

Database table to use Enter the table name that you want to use for the report (this

is the name you gave the database table when you imported

the file into the reporting utility as described previously in

Importing Core Model Output). Select the table name from

the available list or type the table name in the field. When

you type the table name it will automatically be expanded to

match a name in the list.

Decimal places to use The default is two decimal places for most reports. You can

specify a number between 0 and 5.

Report all states/counties? If you want to report emissions for all states or counties

included in the core model output file, click in this field to

specify yes. If you select all, the next report option (Report

one state/county) is removed from the window.

Report one state/county Select a state or county from the list or type the name of the

state/county directly into the field. When you type the

state/county name it will automatically be expanded to

match a name in the list. 
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EPA NONROAD Emissions Model User’s Guide 5-11

Pollutants to report The “pollutants to report” option allows you to select a

grouping of pollutants to report. Designate the group of

pollutants to report from the list of pollutant choices and

descriptions. Depending on your selection, the “Select the

HC” field and/or the “Select the PM size” field may be

removed from the window. For example, by choosing all

PM, it is no longer necessary to specify a hydrocarbon type

or a particulate matter size.

Fuel Type This option allows you to report all fuels or to specify a

single fuel to report. The options are All fuels, CNG,

Diesel, Gasoline, and LPG. All equipment types which have

lumped fuels (HP < 25) are reported as gasoline.

Select the HC When you select a group of pollutants that include

hydrocarbon emissions, you need to specify the hydrocarbon

species that you want to report. Select the hydrocarbon to

report (i.e, THC, TOG, NMOG, NMHC, VOC).

Select the PM When you select a group of pollutants that include

particulate emissions (with the exception of All PM) , you

need to specify the particulate species that you want to

report. Select the size of particulates to report (i.e., PM10, or

PM2.5).

Note: Total hydrocarbons is also reported when reporting non-exhaust hydrocarbon emissions. 

This occurs for the pollutant groups: All Pollutants, Non-Exhaust, and All HC.

If a single fuel is reported, other than diesel, it is important to remember that all sources

with HP < 25 have been lumped into one category and will be reported as gasoline.
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EPA NONROAD Emissions Model User’s Guide 5-12

GENERATING REPORTS

Note: All emissions are reported as short tons (i.e., 2000 lbs).

Once you have imported the necessary output files from the core model, reports can easily be

generated with the reporting utility. When a report is generated, a window opens and the report is

displayed in a Print Preview window.

Running a Report

To run a report, follow these steps:

1. From the Main Menu, select Reports  “Report Name”

2. Enter the report options. A message box is displayed when an error is detected

informing you of the problem encountered. Make the necessary changes and continue.

3. After all required options have been specified, select Run. If a required field is left

blank or an incorrect entry has been made, a message box will be displayed. You must

correct the detected error and attempt to Run again. Once the report has been

generated, it will appear in a window.

4. To return to the main menu without running the report select Cancel.

Tip: User specified report options will remain in the window until closed (Cancel). If you want

to run more than one report which uses the same options window then leave the report

options window open and select another report from the Reports submenu. The report

title will be changed in the options window. Specify RUN. The same options (database

table, decimal places, pollutants, etc.) will be used for the report. This can save you a lot

of selecting/specifying report options.

Viewing a Report in Print Preview

For easier viewing maximize the report window. As you move the cursor across the report, it

changes from an arrow icon to a magnifying glass icon. To alternately zoom in or out of the

report, click the mouse while the cursor is on the report.

To view a specific portion of the report:

1. Locate the desired section of the report in Zoom Out mode.
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EPA NONROAD Emissions Model User’s Guide 5-13

Figure 5-4: Report title area.

2. Zoom In to the area of interest for detailed viewing.

3. To page up or down through a multipage report, press <PgUp> or <PgDn> while in

the Zoom Out mode. In either the Zoom In or Zoom Out modes, clicking on the

arrows in the lower left corner of the report window or typing the page number at the

bottom of the Print Preview window and pressing <Enter> will also move you to the

desired page.

To provide a consistent look for all reports, the report title area for each standard report in the

reporting utility is similar in design (Figure 5-4). The first two lines identify the report name and

attributes which include the user-specified fuel type, report units, and the state/county

specification. Following these lines are the user title lines which come from the core model

output file. The next line, also coming from the core model output file, designates the period of 

emissions estimates. The final line of the report title area indicates the date and time that the core

model run was generated and the date that the report was created.
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EPA NONROAD Emissions Model User’s Guide 5-14

The Reporting Utility menu bar has only one option, File, when viewing a report. A displayed

report can be printed by selecting File  Print. By selecting File  Print Setup you can also

modify the print setup to adjust the margins, the page orientation, and the printer selection This

may be necessary if you have pagination problems printing a report (primarily due to different

printer font sizes).

Note: The abbreviation NA (not available) is printed in a report for entries of missing data. If a

column of data contains one or more NA entries, then the subtotals and totals for that

column will also be listed as NA.

Also, only sources with nonzero emissions are shown in a report. For example, if the core

model output file was generated for only lawn and garden source categories, then only

lawn and garden SCC codes with nonzero emissions for at least one pollutant will be

reported.

Warning: If the format of the value to be displayed in a report column exceeds the column width

then the value will be wrapped to the following line. For example, 

123,456.789 might be written as 123,456.7

 89

This should only occur when you have specified more than the default number of

decimal places to display. You can avoid this problem by specifying fewer decimal

places to display and rerunning the report.

Appendix C contains examples of all standard reports for a core model run of Travis County,

Texas emissions.

Exporting to Excel

An option to export the line item report data to an Excel spreadsheet is available by selecting File

 Export to Excel. When selected, a dialogue box is opened to specify the Excel output file

name. After the name is specified it is displayed in a window where you can select Export

Report to create the file. When completed a message is displayed.

The spreadsheet file will contain the line item information from the report with appropriate

column headings. It will not contain subtotals, grand totals, or report title information. The

spreadsheet will have columns for all species and modes even though for example, you selected 
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EPA NONROAD Emissions Model User’s Guide 5-15

to report only exhaust particulate matter. In addition, there are fields labeled “Missing species”

which are used by the reporting utility for totaling purposes. The numerous additional columns

can be deleted in Excel if you do not want or need them.

COMPARING MODEL RUNS

In addition to allowing you to generate and view reports from single model runs, the reporting

utility provides you with the ability to compare the results of two separate model runs. When you

select Compare from the reporting utility main menu the comparison reports include:

• Compare Two Model Runs by HP and Source Classification

• Compare Two Model Runs by Pop and Fuel

• Compare Two Model Runs by SCC

• Compare Two Model Runs by Source Classification.

When comparing two runs, the report only shows the records that the two runs have in common. 

For example, it you select a report that lists information by source classification code, only that

information pertaining to source classification codes that the two model runs have in common will

be shown in the comparison report. Similarly, if you are interested in comparing two model runs

by horsepower and source classification, you will get horsepower ranges within source

classifications that the two runs have in common. If there are no common records between the

two runs, you will get a message that there is nothing to report.

In order to reasonably compare values between two model runs the simulations must contain the

same units. Since emissions are always output as short tons the period type must be the same

between the two simulations. For example, a tons/year simulation compared to a tons/season will

cause an informative message to be displayed and request you to select different tables to

compare.

For the comparison reports by HP and Source Classification, SCC, and Source Classification, the

report displays the results of model run 1, model run 2, the difference between model run 2 and

model run 1, and the percent difference for a single user-specified pollutant. For the Pop and Fuel

comparison report, the report displays only the results of model run 1 and model run 2 side by

side.
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EPA NONROAD Emissions Model User’s Guide 5-16

Figure 5-5: Report options for comparing two model runs.

To compare the results of two separate model runs, follow these steps:

1. From the Main Menu, select Compare  “Report Name”

2. Enter the report options. For the comparison reports Compare Two Model Runs by

Source Classification, Compare Two Model Runs by SCC, and Compare Two Model

Runs by HP and Source Classification, the report options are shown in Figure 5-5. For

the comparison report Compare Two Model Runs by Pop and Fuel, the report options

are shown in Figure 5-6. A message box is displayed when an error is detected

informing you of the problem encountered. Make the necessary changes and continue.
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EPA NONROAD Emissions Model User’s Guide 5-17

Figure 5-6: Report options for comparing two model runs by population and fuel.

3. After all required options have been specified, select Run. If a required field is left

blank or an incorrect entry has been made, a message box will be displayed. You must

correct the detected error and attempt to Run again. Once the report has been

generated, it will appear in a window.

4. To return to the main menu without running the comparison, select Cancel.

Refer to the previous section on Viewing a Report in Print Preview for a discussion of viewing

and printing the generated report. Examples of all comparison reports are provided in 

Appendix D.

COMPACTING AND REPAIRING DATABASES

If a database contains many large tables, it may slow the operation of the reporting utility and take

up substantial space on the hard drive. This is particularly true if you remove large simulations. 

Furthermore, a computer crash may corrupt a database. For these reasons, the model installation

includes a utility that allows you to compress and repair databases. To start the Compact and

Repair Utility double click on the Compact Utility icon.
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EPA NONROAD Emissions Model User’s Guide 5-18

Note: The Reporting Utility must be closed before running the Compact and Repair Utility.

The Compact and Repair Utility menu items are:

File  Exit Exit the utility.

Utilities

 Compact Database Compact a selected database.

 Repair Database Repair a selected database.

To compact a database follow these steps:

1. Select Utilities  Compact Database.

Note: To compact a database, you will need temporary storage space on your disk that is as

much as the size of the *.mdb file that you are compressing.

2. An open file dialog box appears that requests you to select the database that you want

to compact. Specify the location of the Nrdata.mdb file.

3. A screen will appear requesting you to enter a directory for temporary storage of the

compacted database (Figure 5-7). Type in the appropriate directory and path.
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EPA NONROAD Emissions Model User’s Guide 5-19

Figure 5-7: Identify a directory for temporary storage screen. 

4. Select Compact to begin the compression process. Depending on the size of the

database, this process may take several seconds or a few minutes. When the process is

complete, a message box will be displayed indicating that the process was completed

successfully and notifying you that the DOS window used to execute the move

command can now be closed. 

Note: If you are running the compact utility on a computer operating under Windows 95, activate

the DOS window if it is not the active window, and click on the X in the upper right

corner of the DOS window to return to the compact utility. For those operating under

Windows 3.1, you must press <Alt-Tab> to get from the DOS window to the compact

utility.

To repair a database that has become corrupted, follow these steps:

1. Select Utilities  Repair Database.

2. An open file dialog box appears that requests you to select the database that you want

to repair. Depending on the size of the database, this process may take several seconds

or a few minutes. When the repair is complete, a message box will appear indicating

that the process is done. 
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ADVICE: To prevent the accidental loss of data resulting from a damaged or corrupted database,

it is strongly recommended that you routinely back-up your database
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EPA NONROAD Emissions Model User’s Guide 6-1

Chapter 6 Advanced Topics

In this chapter of the user’s guide, the following topics are discussed:

• a description of how data are grouped for use in estimating emissions,

• a description of the option file packets,

• a description of all input data files,

• information on how to incorporate local data by editing data files, and

• steps involved in running multiple model runs in a batch file.

INTRODUCTION

The NONROAD model includes standard data files and tables that allow you to easily estimate

the emissions from a wide variety of nonroad equipment and vehicles for any region of the

country. As discussed in Chapters 3 and 4, you can quickly set up an option file specifying the

parameters that are applicable to your modeling scenario using default data.

The NONROAD model was also designed, however, to provide you with the flexibility to create

accurate emissions estimates based on locally specific data that may be available to you. For

example, you may have developed more up-to-date information for equipment populations in a

particular region than the default data available in the model. Similarly, you might want to

estimate the emissions for a particular category of nonroad equipment at a subcounty regional

level. The steps involved in modifying the default data input files and tables are provided in this

chapter of the User’s Guide. In addition, an example is provided for modifying inputs for

subcounty runs.

While editing input files lets you adapt the model to specific local conditions, it also lets you

change the model in ways that lead to invalid results. In particular, the interdependency between

some inputs means that changes can affect outputs in surprising ways. The NONROAD model is

designed to warn you about the most obvious input errors, but avoiding more subtle, but serious,

errors requires understanding how the core model works.

You must be certain that any added data records are uniquely identified. Results will be

unpredictable if there are multiple records with matching key fields that have different data

values. For example, the file that contains monthly adjustment factors used to calculate the

fraction of annual activity in a given month is identified by a regional and a SCC code. If you add

a record to this file with the same regional and SCC code as an existing record, with differences in
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EPA NONROAD Emissions Model User’s Guide 6-2

the monthly distributions, then the output may not be what you intend. Searches are performed

differently depending on the data file and processing routine. Do not assume that the first record

matching the key fields will be used. Some searches stop at the first match, others find the last

match, and still others sort the data before searching and the order of input data records is no

longer significant.

Note: The notes in this chapter offer guidance, but EPA’s technical support documents provide

more detail. A list of the NONROAD technical support documents can be found in the

Technical Documentation section of Chapter 1. If you have questions, e-mail EPA

nonroad modeling staff at nonroad@epa.gov

Warning: While editing input files lets you adapt the model to specific local conditions, there is

the possibility of changing the model in ways that lead to invalid results. An

understanding of data relationships is recommended before changes are made to the

data files.

HOW DATA ARE GROUPED IN THE NONROAD MODEL

As discussed briefly in Chapter 4, information used by the NONROAD model for estimating

emissions, including user-specified options, data files, and data tables, are input into the core

model through an option file. The information contained in each option file is separated into

“packets” based on common information. For example, all data files related to the population of

equipment for a modeling region is grouped in a single packet as is information related to the

period of time for which you are interested in estimating emissions.

When viewing an option file through a text editor, the keyword that identifies a packet is

surrounded by forward slashes (“/”) and can appear in upper case, lower case, or mixed case. For

example, the packet identifier for all of the data files related to the population of equipment is

/POP FILES/. To designate the end, or terminator, of a packet, the keyword END is used, also

surrounded by forward slashes (i.e., /END/). The /RUNFILES/, /POP FILES/, and /GROWTH

FILES/ packets in an option file can be seen in Figure 6-1.
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EPA NONROAD Emissions Model User’s Guide 6-3

------------------------------------------------------

 This is the packet that lists the names of output files

 and some of the input data files read by the model.

------------------------------------------------------

/RUNFILES/

ALLOC XREF : c:\nonroad\data\allocate\allocate.xrf

ACTIVITY : c:\nonroad\data\activity\activity.dat

TECHNOLOGY : c:\nonroad\data\tech\tech.dat

SEASONALITY : c:\nonroad\data\season\season.dat

REGIONS : c:\nonroad\data\season\season.dat

MESSAGE : travis.msg

OUTPUT DATA : travis.out

EPS2 AMS : travis.ams

/END/

------------------------------------------------------

This is the packet that defines the equipment population

files read by the model.

------------------------------------------------------

/POP FILES/

 :c:\nonroad\data\pop\tx.pop

/END/

------------------------------------------------------

This is the packet that defines the growth files

read by the model.

------------------------------------------------------

/GROWTH FILES/

National defaults :c:\nonroad\data\growth\nation.grw

/END/

Figure 6-1: Option file showing packet identifiers and terminators.

The following packets make up the NONROAD model option file:

Packet Identifier Required Description

/PERIOD/ Yes Period of time to model

/OPTIONS/ Yes Run title, fuel specs, temperatures

/REGION/ Yes Region to model

/RUNFILES/ Yes A set of input and output file names

/SOURCE CATEGORY/ No Source categories to process

/POP FILES/ Yes Equipment population file names

/GROWTH FILES/ Yes Projection/backcast data file names

/ALLOC FILES/ Yes Spatial allocation file names

/EMFAC FILES/ Yes Emission factors file names

/DETERIORATE FILES/ No Deterioration factors file names

/MODEL YEAR OUT/ No By-model-year output file name

/PM BASE SULFUR/ No Diesel sulfur content corresponding to base

emission factors 

/STAGE II/ No Percent reduction due to Stage II control
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EPA NONROAD Emissions Model User’s Guide 6-4

If a packet is required by the core model to estimate emissions and is not found during a run then

an error message will appear and the program will stop. Each line within an option file packet

begins with a 20 character label. In most cases, the core model does not read these first 20

characters as they exist simply for the purpose of identifying the information provided. For

example, the line in the /OPTIONS/ packet that indicates minimum temperature ignores the

‘Minimum temper. (F):’ label. A few packets use these first 20 characters to specify a keyword

which identifies the type of data file. For example, the /RUNFILES/ packet identifies the output

message file with the keyword ‘Message’.

One convenient aspect resulting from the use of a packet input structure is that packets can appear

in any order in an option file. Furthermore, any type of notes or descriptions that aid in describing

the packet can be placed between the individual packets. When executed, the core model searches

for packet identifiers and reads the data between the identifier and the packet terminator. All

other lines in the file are ignored. The file, template.opt, provided with the NONROAD model

contains a complete description of each packet including format requirements.

INPUT DATA PACKETS AND DATA FILES 

As indicated above, all data input packets with the exception of that containing source category

data and deterioration factor files are required for the model to accurately estimate emissions from

nonroad sources. In many of these packets, data are supplied in a series of input data files. In

other packets, information relevant to any scenario you are interested in modeling is supplied

through user-specified options.

Note: To assist in better understanding the format of information in data files, it is suggested that

you open each data file through a text editor as you read the information in this chapter. 

The data files are in a subdirectory called Data under the Nonroad directory. Each of the

data files provided with the NONROAD model follows the ‘packet’ structure of the input

option file. All files contain descriptive information including format specifications.

Review of Previously Described Packets

Some of the NONROAD model input packets from the options file have already been discussed in

Chapters 3 and 4. They are briefly reviewed here for completeness. Please refer to the previous

chapters for a more complete discussion of the /OPTIONS/, /REGIONS/, /PERIOD/, and

/SOURCE CATEGORY/ packets.

The /OPTIONS/ packet defines several of the user-specified options that make up a modeling

scenario. /OPTIONS/ include descriptive titles, fuel specifications that will be in effect during the

modeling period, and typical ambient temperatures for the period. The order of the records in this

packet are fixed.
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EPA NONROAD Emissions Model User’s Guide 6-5

The period packet, identified as /PERIOD/, defines the period of time that you are interested in

modeling. The order of the records in this packet are fixed. Furthermore, the selection of certain

parameters will cause some of the records in /PERIOD/ to be ignored.

The /REGION/ packet, defines the region that you are interested in modeling. Regions are

defined using two types of parameters. The first specifies the type of region and the second the

region codes to be included.

The source category packet, identified as /SOURCE CATEGORY/, is used to identify which

source categories are to be processed. This is an optional packet; if you do not specify a list of

SCC codes, the model will calculate emissions estimates based on all source categories equipment

in the population files.

Runfiles Packet

The runfiles packet, identified as /RUNFILES/, defines input data file types required by the model

and output files created (see previously referenced Figure 6-1). These data file types contain

information that is universal to all regions and emissions species. Each file type is identified by a

keyword(s) which appears in columns 1 to 20 of the /RUNFILES/ packet. The names for these

file types may appear in any order within the packet but each must be preceded by a valid

keyword. 

Keywords Input Output Required Description

ACTIVITY   Defines equipment use per year

ALLOC XREF   Allocation indicator lookup table

REGIONS   Geographic region definitions

SEASONALITY   Temporal adjustment data

TECHNOLOGY   Technology type distributions

MESSAGE   Output message file

OUTPUT DATA   Emission estimates (for RU)

EPS2 AMS  Emission estimates (EPS2 format)

Each of the input data files contained in the /RUNFILES/ packet, along with their format, are

described below.

ACTIVITY

The file identified by the keyword ACTIVITY, contains the activity data for the core

model. Activity.dat is the data file provided with the NONROAD model and these default

values are described in the EPA documentation report NR-005b. The activity is defined as

how often a piece of equipment is used in a year. This file also contains other information

about the equipment, such as average load factor and gas tank volume. Global SCC codes
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EPA NONROAD Emissions Model User’s Guide 6-6

can be used to indicate entire groups of equipment types. A sample of the text of the

activity file shown is shown below to illustrate the look of the input file.

..............

..............

------------------------------------- Regio chType HPmn HPmx LFac Units Hours/Yr AgeAdj

/ACTIVITY/

2260002006 2-Stroke Tampers/Rammers ALL 0 9999 0.55 Hrs/Yr 160 DEFAULT

2260002009 2-Stroke Plate Compactors ALL 0 9999 0.55 Hrs/Yr 166 DEFAULT

..............

..............

The load factor (“LFac”) and annual usage (“Hours/Yr”) are both directly used to calculate the

exhaust emissions. The age adjustment (AgeAdj) allows annual usage to vary with age; however,

this feature is not functional in this version of the model.

In addition to providing the input data by SCC, they can be specified by region, technology type,

and power level. The default NONROAD files use the same estimates for all regions (“Regio”),

technology types (“TchType”), and power levels. 

If alternative data exists, separate input data can be used either by modifying the entire file or

including separate estimates in the same file as the default national estimates using the Region

Code, which is a code defined in the temporal allocation file (“season.dat”).

Different activity by technology type was allowed with the original intention being that different

technologies represented different power ranges within each application. (For example, electric

lawnmowers could have been included with a zero emissions rate but with less activity than

gasoline powered lawnmowers.) However because technology type is currently used to represent

the emission standards, the activity for a given SCC should be the same for ALL technology types.

The activity can be a function of the power level for a given piece of equipment. For instance, a

survey method produced alternative annual activity (“Hours/Yr”) for large (>25 hp) diesel

construction equipment for Houston, so the alternative activity can be used along with the default

information for the smaller equipment as shown in the example below.

...........

...........

SCC Code SCC Equipment Description Regio TchType HPmn HPmx LFac Units Hours/Yr AgeAdj

/ACTIVITY/

2270002003 Diesel Pavers ALL 0 9999 0.59 Hrs/Yr 821 DEFAULT

2270002003 Diesel Pavers SW ALL 0 25 0.59 Hrs/Yr 821 DEFAULT

2270002003 Diesel Pavers SW ALL 25 9999 0.59 Hrs/Yr 719 DEFAULT

...........

The exhaust emissions estimates are directly related to the load factor and activity (hours/year), so

a change in those estimates will proportionately affect the emissions calculated. Also, because the

load factor and activity (hours/year) are used to determine the life of the equipment in years, the

age distribution is affected by modifying these estimates. For instance, if activity and load factor

are reduced, then the equipment will be expected to last longer in years, so the age distribution

shifts to older equipment.
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EPA NONROAD Emissions Model User’s Guide 6-7

The format for this data is as follows:

Packet Identifier: /ACTIVITY/

Column Description

Line: 1 - 10 Equipment code (SCC)

12 - 51 Equipment description (not used)

52 - 56 Region code (refer to description of

REGIONS section below)

57 - 66 Technology type

67 - 71 Minimum horsepower

72 - 76 Maximum horsepower

77 - 81 Load factor

82 - 86 (not used)

87 - 96 Activity level units (Options: Hrs/Yr,

Hrs/Day, Gal/Yr, and Gal/Day)

97 - 106 Activity level

107 - 116 Identifier for age adjustment curve

(DEFAULT=no adjustment)

Warning: The EPA does not recommend changing the activity files. This is because the activity,

equipment population, load factor, and average life are all linked and changes can have

surprising results. For details, see EPA’s technical documents or talk to EPA nonroad

modeling staff.

ALLOC XREF

The file identified by the keyword ALLOC XREF is the allocation indicator lookup table

used by the core model. Allocate.xrf is the data file provided with the NONROAD model. 

These data are used to allocate equipment type populations from one regional level to

another. For each SCC in the file, the code is cross referenced to a list of indicator codes

and their associated coefficients. The model will retrieve the indicator data identified by

the indicator codes and calculate a linear combination. Global SCC codes can be used to

indicate entire groups of equipment types.

To calculate the allocation factors, the model first calculates a linear combination of

allocation indicator values. The linear combinations are defined in this file. For instance,

if an SCC were discovered to be a function of two codes, then the indicator could be a

combination of the two codes (e.g., RVP and POP) as shown below for a given county,

and the calculation would be as follows. (This is a hypothetical example only and not an

accurate reflection of in-use allocation.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-8

Indicator = 0.6 * (County RVP)/(State RVP) + 0.4 * (County POP)/(State POP)

County equipment population = Indicator * State equipment population

In the current version of the model, there is one indicator code assigned to each SCC. In

the example below, the allocate cross reference file was modified for recreational vehicle

use to reproduce the hypothetical example above.

Current Version

..........

..........

/ALLOC XREF/

2260001000 1.0

2260001000 RVP

..........

..........

Sample Alteration (this is not an accurate reflection of the allocation)

..........

..........

/ALLOC XREF/

2260001000 0.6 0.4

2260001000 RVP POP

..........

..........
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-9

The indicator codes are arbitrary. The codes in this file are:

POP

LSC

CON

MFG

COM

LOG

FRM

HOU

RVP

AIR

OIL

GC

MIN

SNM

SBR

SBC

WIB

WOB

Human population

Employees in landscape and horticulture services

Dollar value of construction 

Employees in manufacturing industry

Number of wholesale establishments

Employees in lumber and wood products industry

Harvested cropland

Number of single and double family homes

Number of recreational vehicle parks

Employees in air transportation industry

Employees in oil and gas extraction industry

Number of public golf courses

Employees engaged in coal mining

Snowmobiles: state registration, snowfall, inverse

human population

Snowblowers residential

Snowblowers commercial 

Recreational marine state fuel consumption, county

water surface area- Inboard

Recreational marine state fuel consumption, county

water surface area- Outboard 

The format for this data is as follows:

Packet Identifier: /ALLOC XREF/

Column Description

Line 1: 1 - 10 Equipment code (SCC)

11 - 20 Coefficient for indicator 1

21 - 30 Coefficient for indicator 2

31 - 40 Coefficient for indicator 3

Line 2: 1 - 10 Equipment code (must match the code in Line 1)

11 - 20 Indicator code of indicator 1

21 - 30 Indicator code of indicator 2

31 - 40 Indicator code of indicator 3
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-10

Note: If you add additional indicator codes and factors to the allocate.xrf file, you must also add

corresponding data files. For example, if you add forest land as an allocation factor for

recreational vehicles, you must provide the model with data files on forest land per county. 

Refer to the section Allocation Files Packet. Furthermore, the input option file must list

the appropriate data file names.

REGIONS

The file identified by the keyword REGIONS, defines the states/counties in each

geographic region. Season.dat is the data file provided with the NONROAD model. The

region packet within the season file associates the region definition with the FIPS code for

a State or County as shown in the example below. New regions can be defined here, but

inputs for the monthly allocation (described below) must be described for any new region

defined here.

........

........

/REGIONS/

SW Southwest 48000 Texas

US National 00000 Nation

........

........

Identification by the region code is arbitrary (SE for Southeast or SW for Southwest) but

the FIPS code must be a valid state or county FIPS code. If a state code is supplied, all

counties in that state are included in the indicated region, unless overridden by a countyspecific record.

Warning: Changing the region does not change altitude or temperatures, but it does change

which activity factor is applied and the allocation of activity throughout the year. In

particular, if you define a new region, you must add the new region to the activity.dat

and the season.dat files.

The format for this data is as follows:

Packet Identifier: /REGIONS/

Column Description

Line: 1 - 5 User-defined region code

6 - 45 Region description (not used)

46 - 50 State or county FIPS code 

51 - 70 State or county name (not used)
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-11

SEASONALITY

The file identified by the keyword SEASONALITY, contains the seasonality (temporal

adjustment data) used by the core model. Season.dat is the data file provided with the

NONROAD model. Two specific types of information are contained in this file, each

identified by a different packet keyword.

The first, identified by the packet identifier /MONTHLY/, provides the monthly

adjustment factors used by the model to calculate the fraction of annual activity occurring

in the given month. For periods longer than a single month (e.g. season), the factors from

each month spanned by the period are summed. The second, identified as /DAILY/,

provides the day-of-the-week adjustments.

If no monthly or daily data for an equipment type is found in season.dat, a warning

message is written to the output message file and the model default values will be used for

temporal allocation. The default values represent an equal distribution of temporal activity

throughout each month of the year. If you change the monthly allocations, you should

check to make sure the allocations sum to one. Likewise, the weekend and weekday

allocations should sum to one for an entire week (i.e. 1 = 5 × weekday fraction + 2 ×

weekend fraction).

The format for the monthly data is as follows:

Packet Identifier: /MONTHLY/

Column Description

Line: 1 - 5 Subregion code (blank = match all)

7 - 16 SCC code (global codes are acceptable)

18 - 51 Equipment description (not used) 

52 - 61 Fraction of annual activity in January 

62 - 71 Fraction of annual activity in February

72 - 81 Fraction of annual activity in March

82 - 91 Fraction of annual activity in April

92 - 101 Fraction of annual activity in May

102 - 111 Fraction of annual activity in June

112 - 121 Fraction of annual activity in July

122 - 131 Fraction of annual activity in August

132 - 141 Fraction of annual activity in September

142 - 151 Fraction of annual activity in October

152 - 161 Fraction of annual activity in November

162 - 171 Fraction of annual activity in December
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-12

The format for the day-of-the-week data is as follows:

Packet Identifier: /DAILY/

Column Description

Line: 1 - 5 Subregion code (blank = match all)

7 - 16 SCC code (global codes are acceptable)

18 - 51 Equipment description (not used)

52 - 61 Fraction of weekly activity in typical weekday day

62 - 71 Fraction of weekly activity in typical weekend day

TECHNOLOGY

The file identified by the keyword TECHNOLOGY, defines the technology type

distributions for the core model. Tech.dat is the data file provided with the NONROAD

model. The technology types are specified by SCC and horsepower range. Global SCC

codes can be used to indicate entire groups of equipment types. The data in these files is

separated into two lines. The first line has the identification information and a list of up to

10 technology types which make up the specified equipment population. The second line

identifies the year and the fraction of population in each technology type. Multiple second

lines may be provided if data is available for different years as shown in the example

below. From the “tech.dat” input file (up to 10 tech types may be defined).

 SCCodes HPminHPmax Tech1 Tech2 Tech3 Tech4 (more>)

Year Fract Fract Fract Fract 

/TECH FRAC/

..........

..........

 2270000000 750 9999 Base T0 T1 T2

1900 1.000 0.000 0.000 0.000

1988 0.000 1.000 0.000 0.000

2000 0.000 0.000 1.000 0.000

2006 0.000 0.000 0.200 0.800

2007 0.000 0.000 0.100 0.900

2013 0.000 0.000 0.000 1.000

..........

..........

The fractions of population by technology type for each year should sum to 1. If the sum

differs from 1.0 by more than +/- 0.002 then the fractions are normalized and a warning

message is generated and displayed. The model will use the distribution beginning with

the specified year, until a new distribution is provided.

The NONROAD model uses the tech types primarily to determine phase-in of emissions

standards. The tech type defines the zero-hour (brand new) exhaust emission factor

(derived from the emission factor files described below) and the deterioration rate. In the

example above, diesel engines (SCC 227000000) of power levels between 750 and 9999
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-13

horsepower can potentially be one of 4 tech types (Base, T0, T1, T2). Older engines

(starting with the 1900 model year) were exclusively the ‘Base’ tech type while new

engines were produced with tech type ‘T0’ beginning with the 1988 model year. The first

emission standard, Tier 1 (tech type ‘T1’) for all equipment types began with the 2000

model year. However, the Tier 2 standard is to be phased-in starting with the 2006 model

year where only 80% (0.800 entry) of the new engines are expected to be Tier 2 (tech type

‘T2’) with the remainder still Tier 1. 

The tech types in NONROAD have meanings that relate to the type of engine and which

emission standard applies to that engine. Other tech types may appear in the default input

files but have zero entries, so are not currently used. The representative tech types are as

follows:

Descriptions for representative tech types.

Tech Type Description

G2H3 Gasoline 2-stroke handheld Class 3

G2H31 Gasoline 2-stroke handheld Class 3 meeting Phase 1 Standards

G2H3C1 Gasoline 2-stroke handheld Class 3 meeting Phase 1 Standards with a catalyst

G2H32 Gasoline 2-stroke handheld Class 3 meeting Phase 2 Standards

G2H3C2 Gasoline 2-stroke handheld Class 3 meeting Phase 2 Standards with a catalyst

G2H4 Gasoline 2-stroke handheld Class 4

G2H41 Gasoline 2-stroke handheld Class 4 meeting Phase 1 Standards

G2H4C1 Gasoline 2-stroke handheld Class 4 meeting Phase 1 Standards with a catalyst

G4H41 Gasoline 4-stroke handheld Class 4 meeting Phase 1 Standards

G2H42 Gasoline 2-stroke handheld Class 4 meeting Phase 2 Standards

G2H4C2 Gasoline 2-stroke handheld Class 4 meeting Phase 2 Standards with a catalyst

G4H42 Gasoline 4-stroke handheld Class 4 meeting Phase 2 Standards

G2H5 Gasoline 2-stroke handheld Class 5

G2H51 Gasoline 2-stroke handheld Class 5 meeting Phase 1 Standards

G2H5C1 Gasoline 2-stroke handheld Class 5 meeting Phase 1 Standards with a catalyst

G2H52 Gasoline 2-stroke handheld Class 5 meeting Phase 2 Standards

G2H5C2 Gasoline 2-stroke handheld Class 5 meeting Phase 2 Standards with a catalyst

G4N1S Gasoline 4-stroke nonhandheld Class 1 side-valve carburetor

G4N1O Gasoline 4-stroke nonhandheld Class 1 overhead-valve carburetor

G2N1 Gasoline 2-stroke nonhandheld Class 1

G2N11 Gasoline 2-stroke nonhandheld Class 1 meeting Phase 1 Standards

G4N1S1 Gasoline 4-stroke nonhandheld Class 1 side-valve carburetor meeting Phase 1 Standards

G4N1O1 Gasoline 4-stroke nonhandheld Class 1 overhead-valve carburetor meeting Phase 1 Standards

G4N1SC1 Gasoline 4-stroke nonhandheld Class 1 side-valve carburetor meeting Phase 1 Standards with a catalyst

G4N1S2 Gasoline 4-stroke nonhandheld Class 1 side-valve carburetor meeting Phase 2 Standards

G4N1O2 Gasoline 4-stroke nonhandheld Class 1 overhead-valve carburetor meeting Phase 2 Standards

G2N2 Gasoline 2-stroke nonhandheld Class 2

G4N2S Gasoline 4-stroke nonhandheld Class 2 side-valve carburetor

G4N2O Gasoline 4-stroke nonhandheld Class 2 overhead-valve carburetor

G4N2S1 Gasoline 4-stroke nonhandheld Class 2 side-valve carburetor meeting Phase 1 Standards

G4N2O1 Gasoline 4-stroke nonhandheld Class 2 overhead-valve carburetor meeting Phase 1 Standards

G4N2S2 Gasoline 4-stroke nonhandheld Class 2 side-valve carburetor meeting Phase 2 Standards

G4N2O2 Gasoline 4-stroke nonhandheld Class 2 overhead-valve carburetor meeting Phase 2 Standards

G4GT25 Gasoline 4-stroke greater than 25 horsepower
December 2002 December 2002

Tech Type Description

EPA NONROAD Emissions Model User’s Guide 6-14

G2GT25 Gasoline 2-stroke greater than 25 horsepower

R12S Gasoline Recreational 2-stroke

R14S Gasoline Recreational 4-stroke

LGT25 LPG greater than 25 horsepower

NGT25 CNG greater than 25 horsepower

Base Early uncontrolled diesel engines (pre-1988 model year engines)

T0 Late model (1988 and later model year) uncontrolled diesel engines

T1 Diesel engine meeting Tier 1 Standards

T2 Diesel engine meeting Tier 2 Standards

T3 Diesel engine meeting Tier 3 Standards

M1 2-stroke gasoline outboard uncontrolled

M2 2-stroke gasoline personal watercraft uncontrolled

M3 4-stroke gasoline in-board uncontrolled

M4 4-stroke gasoline outboard uncontrolled

M5 2-stroke outboard with carburetor and ignition modifications

M6 2-stroke outboard with modifications and catalyst 

M8 2-stroke outboard with electronic fuel injection

M9 Direct-injection type A outboard

M10 Inboard with electronic fuel injection

M13 4-stroke gasoline personal watercraft 

M14 2-stroke gasoline personal watercraft with major modifications

New tech types may be defined for any SCC as long as the emission factors and

deterioration rates are also provided for those new tech types. In many cases above, EPA

has estimated what tech type of engines will be used for future year standards so the tech

type descriptions and relative sales fractions may change as manufacturers introduce

engines meeting the emission standards. 

Note: Proposed regulations are estimated to reduce the number of 2-stroke engines sold in the

future in favor of 4-stroke engines. Therefore, spark ignition engines of less than 25

horsepower are lumped into one SCC category, eliminating the SCC distinction between

2- and 4-stroke gasoline, LPG, and CNG engines.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-15

The format for the data in this file is as follows:

Packet Identifier: /TECH FRAC/

Column Description

Line 1: 6 - 15 SCC code (globals can be used)

21 - 25 Minimum horsepower range 

26 - 30 Maximum horsepower range

35 - ? List of tech type codes (each in field of 10

characters)

Line 2 +: 1 - 5 Year

35 - ? Fractions for each tech type (each in field of 10

characters)

Warning: The technology type data are generally used with the emission factor data to model

changes in control strategies. While users may wish to change the technology type

data to experiment with various phase-in strategies, they should use the default values

for official submittals to EPA.

Population Files Packet

The population files packet, identified as /POP FILES/, lists all of the files containing equipment

population data. The data in these files ultimately determines which equipment types will be

processed in the core model. If population estimates for a given equipment type are included in

any of these files, and you do not exclude the equipment from processing by user-specified

options (i.e., with the /SOURCE CATEGORY/ packet in the option file), the model will use all of

these population estimates to calculate emissions. The entire equipment population file will be

processed and estimated emissions written to the output data file unless you specify a subset of

equipment types.

For convenience and ease of data management, the population data have been disaggregated into

separate files by state and a file for national totals. The /POP FILES/ packet in an option file was

shown earlier in Figure 6-1.

The *.pop files, one for each state, contain the equipment population estimates for the

NONROAD model. The “*” refers to the two character state abbreviation (us for the national total

file). These data drive the rest of the model in terms of which equipment types will be processed. 

The model uses the closest year which comes before the episode year. Population estimates for an

entire state may be allocated to county level (refer to the Allocation Files Packet section below). 

The sum of all county equipment populations within a state is equal to the state population values.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-16

The input data are defined by the region (“FIPS” defining State or County) and year in which the

estimates are valid (“Year”), SCC, and by power level grouping (“HPmin” and “Hpmax”). 

Subregion codes (“SUBR”)can be used to provide inputs for partial counties. 

The horsepower range (HP) is lower bound exclusive and upper bound inclusive. For example, a

range identified by a minimum HP of 3 and a maximum HP of 6 is the range 3 < HP  6.

The acceptable ranges are:

0 to 1 25 to 40 600 to 750

1 to 3 40 to 50 750 to 1000

3 to 6 50 to 100 1000 to 1500

6 to 11 100 to 175 1500 to 2000

11 to 16 175 to 300 2000 to 3000

16 to 25 300 to 600 Greater than 3000

The average of the horsepower range is used frequently in NONROAD model calculations. The

option to specify a single weighted average horsepower is provided in the population file format. 

If the weighted average horsepower field is blank then the average is computed from the specified

range.

Note: It is expected that in the future equipment populations will shift from 2-stroke to 4-stroke

spark ignition engines. In order to allow for these predicted shifts of equipment, spark

ignition engines have been grouped into single SCCs with 2-stroke, 4-stroke, CNG and

LPG engines in separate technology groups. Therefore, some SCCs are missing from the

population file while others have the combined populations for all spark ignition engines.

When modifying the equipment populations with local information, usually available is the total

population of the equipment type, or populations within a power range. The NONROAD model

needs the equipment population distributed by power level, so the revised information must be

mapped into each power level range. The most widely used method for this mapping procedure is

to distribute the revised population according to the default national distribution by power level

range.

EPA has designed an Excel Program file that allows manipulation of the population files allowing

the user to save a text file that can be used in NONROAD. With the Excel file, a column of data

can replace the default data more easily than using a text editor. This file makes the redistribution

method described above straight-forward. 

The population file also provides the median life estimates (“Life”) and directs the model to the

type of scrappage function (“ScrapFlag”) to determine the age distribution for each SCC and

power level grouping. The scrappage function is defined in the growth file (named “Nation.grw”). 
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-17

A change in the “Life” estimate will proportionally affect the median life in years. If the median

life in years is known, then the life in hours at full load needs to be modified and can be calculated

using the equation below.

Median Life (hours at full load) = Median life (years) * (A * LF)

where

LF = Load Factor (fraction of available power) (from Activity File)

A = Activity (hrs/yr) (from Activity File)

Median Life = Median life in hours at full load (from Population File)

The median life in years is not the same value as the average age of equipment in use. The median

life is the typical age when the engine is scrapped, while the average age of equipment in-use

depends upon the historic sales and the rate of scrappage. Typically the average age of equipment

in-use is lower than the median life of the equipment. 

The format for this data is as follows:

Packet Identifier: /POPULATION/

Column Description

1 - 5 FIPS code

7 - 11 Subregion code (used for subcounty estimates)

13 - 16 Year of population estimates 

18 - 27 SCC code (no globals accepted)

29 - 68 Equipment description (ignored)

70 - 74 Minimum horsepower range

76 - 80 Maximum horsepower range (ranges must match

those internal to model)

82 - 86 Weighted average horsepower (optional)

88 - 92 Average life (in hours of use)

93 - 102 Flag for scrappage distribution curve (DEFAULT

= standard curve)

106 - 122 Population estimate

Warning: The EPA does not recommend changing the equipment population files. This is

because the activity, equipment population, load factor, and average life are all linked

and incomplete changes can lead to surprising results. For details, see EPA’s

technical documents or talk to EPA nonroad modeling staff.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-18

Growth Files Packet

The growth files packet, identified as /GROWTH FILES/, lists the names of all of the files

containing future year projection or backcasting data (see previously referenced Figure 6-1). The

growth data provided with the NONROAD model is in a single file called “nation.grw” and is

separated into data packets. Similar to population files, growth data can be placed in separate

files, such as by state or county, to simplify data management. 

The packets that make up the growth files are:

Packet Identifier Required Description

/INDICATORS/  Cross reference between SCC and growth

indicator code.

/GROWTH/  Growth values by FIPS, indictor code, and

year.

/SCRAPPAGE/  Default scrappage curve used for model year

distribution calculations.

/ALTERNATE SCRAPPAGE/ Alternate scrappage curve.

Note: For more information concerning how NONROAD handles growth and scrappage, consult

Technical Reports NR-007a and NR-008b.

The /INDICATORS/ packet, provides a cross reference of equipment code (SCC) to growth

indicator. The indicator code is an arbitrary code that identifies an actual predicted value such as

human population or employment. The indicator codes may be defined by SCC (or SCC grouping

following the hierarchy), power level range, and technology type. However the default values in

the model only define codes applicable to all power and technology types and for general

categories (construction, lawn and garden, etc.) as described in EPA’s NONROAD documentation

report NR-008. Below is a sample of lines from the /INDICATORS/ packet.

.........

.........

FIPS Ind SCCodes HPminHPmax Tech Description (not used)

/INDICATORS/

00000 010 2267008000 0 9999 ALL LPG Airport Service Equipment

00000 010 2268008000 0 9999 ALL CNG Airport Service Equipment

00000 011 2270008000 0 9999 ALL Diesel Airport Service Equipment

.........

.........
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-19

The indicator codes found in the nation.grw file are:

010 -- Airport Service - Total

011 -- Airport Service - Diesel

012 -- Airport Service - Gasoline

013 -- Airport Service - LPG

014 -- Airport Service - CNG

020 -- Construction- Total

021 -- Construction - Diesel

022 -- Construction - Gasoline

023 -- Construction - LPG

024 -- Construction - CNG

030 -- Farm - Total

031 -- Farm - Diesel

032 -- Farm - Gasoline

033 -- Farm - LPG

034 -- Farm - CNG

040 -- Industrial - Total

041 -- Industrial - Diesel

042 -- Industrial - Gasoline

043 -- Industrial - LPG

044 -- Industrial - CNG

050 -- Lawn & Garden -Total

051 -- Lawn & Garden - Diesel

052 -- Lawn & Garden - Gasoline

053 -- Lawn & Garden - LPG

054 -- Lawn & Garden - CNG

060 -- Light Commercial - Total

061 -- Light Commercial - Diesel 

062 -- Light Commercial - Gasoline

063 -- Light Commercial - LPG

064 -- Light Commercial - CNG

070 -- Logging - Total

071 -- Logging - Diesel

072 -- Logging - Gasoline

073 -- Logging - LPG

074 -- Logging -CNG

080 -- Railway - Total

081 -- Railway - Diesel

082 -- Railway - Gasoline

083 -- Railway - LPG

084 -- Railway - CNG

090 -- Recreational - Total

091 -- Recreational - Diesel

092 -- Recreational - Gasoline

093 -- Recreational - LPG

094 -- Recreational - CNG

095 -- Recreational - 2sATV

096 -- Recreational - 4sATV

100 -- Oil Field - Total

101 -- Oil Field - Diesel

102 -- Oil Field - Gasoline

103 -- Oil Field - LPG

104 -- Oil Field - CNG

The format for this data is as follows:

Packet Identifier: /INDICATOR/

Column Description

1 - 5 State/county code (FIPS)

7 - 10 Indicator code (arbitrary alphanumeric code)

12 - 21 Equipment code (SCC)

23 - 27 Minimum HP range

28 - 32 Maximum HP range

34 - 43 Technology type

The /GROWTH/ packet contains the estimated values used to compute growth factors for each of

the indicator codes. The /GROWTH/ data packet specifies an estimated value by state/county

code (FIPS), a growth indicator code, and year. The model will use the estimated values from the

two years which are closest to the base year (the year of the equipment population estimate) and

the projection year (the specified episode year). It then calculates an annual growth factor based

on the increase in the estimated values. The growth may be defined by State or County through

the FIPS code. At least two years need to be provided to indicate a growth rate, but more may be

included to provide for a variable rate over certain periods as shown in the example below. 
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-20

........

........

FIPS SUBR Year Code Indicator Value

/GROWTH/

00000 1996 010 1000

00000 1996 011 1000

........

........

00000 2000 010 1240

00000 2000 011 1277

........

........

00000 2005 010 1553

00000 2005 011 1622

........

........

The data is easily modified by editing the text file. The growth rate is determined from the ratio of

indicator values in one year compared to another, so the choice of value for the base year (1000 in

the example above) is not restricted (except for zero). The indicator may be actual estimates (e.g.

number of employees) or any other kind of indicator as long as it is understood that future years

will be compared with the base year, so the units for the indicator must be consistent. 

The resulting annual growth rate is applied to base year populations to obtain future-year

predictions (or prior year backcasting) of equipment populations. Global FIPS codes can be used

to provide estimated values for an entire state or even the entire country. The model will use the

most refined data; county-specific where it is available. 

The format for this data is as follows:

Packet Identifier: /GROWTH/

Column Description

1 - 5 State/county code (FIPS)

6 - 10 Subregion code (blank = applies to all subregions

11 - 15 Year of estimate (4-digit year)

17 - 20 Indicator code (arbitrary alphanumeric code)

26 - 45 Estimated value

An additional packet that must appear in the growth files is the /SCRAPPAGE/ packet. This

packet contains the definition of the default scrappage curve used for the model year distribution

calculations. All equipment types in which the scrappage flag in the population file is set to

DEFAULT will use this scrappage curve. The scrappage curve is the percentage of equipment

scrapped as a function of the fraction of useful life consumed. For example, the default scrappage

curve has 9 percent of equipment scrapped when the equipment has reached 45 percent of its

useful life.

The format for this data is as follows:
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-21

Packet Identifier: /SCRAPPAGE/

Column Description

1 - 10 Fraction of useful life already consumed

11 - 20 Percentage of equipment scrapped

An optional packet of the growth data file is the /ALTERNATE SCRAPPAGE/ packet. This

optional packet can be used to define scrappage curves that are used in place of the default

scrappage curve for selected equipment types. To apply the /ALTERNATE SCRAPPAGE/ curve

to an equipment type, you must first modify the records of the population file for the selected

equipment type by changing the scrappage flag from DEFAULT to some user-defined name. The

name can be any alpha-numeric string up to 10 characters in length (e.g., “chain saw” or

“motorcycle”). The next step is the creation of the /ALTERNATE SCRAPPAGE/ packet. The

packet is similar to the /SCRAPPAGE/ packet in form, but allows for multiple columns for

defining up to 10 alternate scrappage curves for various equipment groups. The first field is the

fraction of useful life consumed. The remaining columns, one for each alternate scrappage curve,

contain the percentage of units scrapped. Another significant difference between this packet and

the /SCRAPPAGE/ curve is that the first record is used to identify the name of the scrappage

curves. These names must match the name used to replace the DEFAULT value of the scrappage

flag in the population files. An example of an alternate scrappage curve is provided in

nation.grw. These data are not referenced in the NONROAD model population files, but simply

provided as an example of an alternate scrappage curve.

The format for this data is as follows:

Packet Identifier: /ALTERNATE SCRAPPAGE/

Column Description

Line 1: 1 - 10 not used

11 - 20 Name used to identify scrappage curve 1

21 - 30 Name used to identify scrappage curve 2

x1 - x0 up to 10 curves

Line 2+: 1 - 10 Fraction of useful life already consumed

11 - 20 Percentage of equipment scrapped in scrappage curve 1

21 - 30 Percentage of equipment scrapped in scrappage curve 2

x1 - x0 up to 10 curves
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-22

Allocation Files Packet 

A list of spatial allocation files used by the core model is contained in the packet identified as

/ALLOC FILES/. Specifically, the data in this packet is used to allocate from state-level 

equipment populations to county-level equipment populations. It could also be used to allocate

national-level equipment populations to state-level. Alternatively, you can include additional data

to allocate from county-level to subcounty-level ( an example of subcounty allocation follows the

description of the allocation file data format).

As seen in Figure 6-2, the /ALLOC FILES/ packet contains numerous data files; one for each of

the indicators found in the allocate.xrf file. Similar to the population files found in the /POP

FILES/ packet, the spatial allocation data files have been segregated into separate files by state

and by indicator type for convenience and ease of data management. The first 20 characters of

each line are ignored and contain a description of the file. These files contain surrogate indicators

used by the model for allocating equipment populations from a larger region type to a smaller

region type (e.g., national-level to state-level or state-level to county-level).

Values for each indicator code are supplied both for the state total and for each county to facilitate

the calculation of allocation fractions for the state equipment population. Below is a sample of the

indicator values for one of the codes. 

..........

..........

Column Format

1-3 Indicator code

6-10 FIPS code (can be global FIPS codes e.g. 06000 = all of CA)

11-15 Subregion code (blank means is entire nation, state or county)

16-20 Year of estimate or prediction

21-40 Indicator value

------------------------------------------------------------------------

/INDICATORS/

CON 48000 1997 27110368

CON 48001 1997 21118

CON 48003 1997 5919

..........

..........
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-23

------------------------------------------------------

This is the packet that defines the spatial 

allocation files read by the model.

------------------------------------------------------

/ALLOC FILES/

RV Park employees :c:\nonroad\data\allocate\tx_rvprk.alo

Golf Course estab. :c:\nonroad\data\allocate\tx_golf.alo

Air Transportation :c:\nonroad\data\allocate\tx_airtr.alo

Contruction empl. :c:\nonroad\data\allocate\tx_const.alo

Havested Cropland :c:\nonroad\data\allocate\tx_farms.alo

Wholesale establis.:c:\nonroad\data\allocate\tx_holsl.alo

Family housing :c:\nonroad\data\allocate\tx_house.alo

Logging empl. :c:\nonroad\data\allocate\tx_loggn.alo

Landscape empl. :c:\nonroad\data\allocate\tx_lscap.alo

Manufacturing empl.:c:\nonroad\data\allocate\tx_mnfg.alo

Oil & Gas employees:c:\nonroad\data\allocate\tx_oil.alo

Census population :c:\nonroad\data\allocate\tx_pop.alo

Resid. snowblower :c:\nonroad\data\allocate\tx_sbr.alo

Comm. snowblower :c:\nonroad\data\allocate\tx_sbc.alo

Snowmobile :c:\nonroad\data\allocate\tx_snowm.alo

Outboard water :c:\nonroad\data\allocate\tx_wob.alo

Inboard water :c:\nonroad\data\allocate\tx_wib.alo

Coal mining empl. :c:\nonroad\data\allocate\tx_coal.alo

/END/

Figure 6-2: /ALLOC FILES/ packet.

The files provided with the NONROAD model are:

Filename Indicator Description

*_pop.alo Human population

*_lscap.alo Employees in landscape and horticulture services

*_const.alo Dollar value of construction 

*_mnfg.alo Employees in the manufacturing industry

*_holsl.alo Number of wholesale establishments

*_loggn.alo Employees in lumber and wood products industry

*_farms.alo Harvested cropland

*_house.alo Number of single and double family homes

*_rvprk.alo Number of recreational vehicle parks

*_airtr.alo Employees in air transportation industry

*_oil.alo Employees in oil and gas extraction industry

*_golf.alo Number of public golf courses

*_coal.alo Employees in coal mining

*_sbc.alo Number of commercial snowblowers

*_sbr.alo Number of residential snowblowers

*_snowm.alo Relative number of snowmobiles

*_wob.alo Water surface area for outboard recreational marine craft 

*_wib.alo Water surface area for inboard recreational marine craft

* Represents the two character state name abbreviation.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-24

The format for these data is as follows:

Packet Identifier: /INDICATORS/

Column Description

1 - 3 Indicator code

6 - 10 FIPS code (can be global)

11 - 15 Subregion code (blank means entire nation, state, or county)

16 - 20 Year of estimation or prediction

21 - 40 Indicator value

Modifying Inputs for Subcounty Runs

The NONROAD model has the capability of estimating emissions at a subcounty level provided

that data for the subcounty level is supplied. To demonstrate how you can modify model inputs to

estimate emissions at a subcounty level, we will again use the example found in Chapters 3 and 4

with the following revision:

You have been given an assignment to estimate the total emissions from residential lawn

mowers with a horsepower range of 1 to 6 in the city of Austin, Texas for summertime,

1998.

In simple terms, the methodology that the model will use to calculate emissions from lawn

mowers with a horsepower range of 1 to 6 in Austin will be to first determine the number of lawn

mowers (1 to 6 HP range) in Travis County (where Austin resides) based on an allocation

indicator from the state-level to the county-level, and then in the Austin metropolitan area based

on an allocation indicator from the county-level to the subregion-level. The allocation indicator

that will be used for this example will be housing. Once the number of lawn mowers in Travis

County has been supplied (either through a separate model run or locally available data), the

model will then estimate the emissions from these sources in Austin (based on the ratio of the

allocation indicator value from county-level to subregion-level).

To modify the input files for this scenario, follow these steps:

1. Create a subregion code for the county which, together with the state/county code in

which the subcounty is contained, will be used to identify the data applied to the

subcounty. Since the Austin metropolitan area is within Travis County, Texas, a

region code could be identified as ‘48453 Austn’ where 48453 is the FIPS code for

Travis County, Texas and ‘Austn’ is the subregion identifier for the Austin

metropolitan area. The subregion identifier can only be up to five characters in

length.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-25

2. Estimate county-level equipment populations for each equipment type of interest. The

most straightforward method for determining this estimate is to have the NONROAD

model produce a county-level estimate using state-to-county allocation. For our

example, the model would be run with the regional inputs set to 

Region level : COUNTY

FIPS code : 48453

and the /SOURCE CATEGORY/ packet modified to include Lawn and Garden

residential lawn mowers.

res 2-stk mowers :2260004010

res 4-stk mowers :2265004010

res LPG mowers :2267004010

res CNG mowers :2268004010

res diesel mowers :2270004010

3. Once the core model run is completed, use the reporting utility to generate a

Population and Fuel Consumption by HP and Source Classification report. This will

provide an estimate of the population of residential lawn mowers in Travis County. 

Next, you must enter the county-level population data into the population files using

the FIPS code for the county where your subregion is located. For our example, the

population file for the state of Texas (nonroad\data\pop\TX.pop) would be modified

as shown in Figure 6-3 where:

• 48000 is the FIPS code for the state of Texas;

• 48453 is the FIPS code for Travis County;

• 1996 is the year of population estimates;

• 2265004010 is the SCC for 2-stroke residential lawn mowers (all engine types

have been lumped into this SCC);

• 1 and 3, and 3 and 6 are the minimum and maximum horsepower ranges,

respectively;

• 47.9 is the expected useful life in number of hours;

• DEFAULT is the flag for scrappage distribution curve with default representing

the standard curve; and

• 1737 (1<HP  3) and 86314 (3<HP  6) represent the population estimates.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-26

48000 1996 2265004010 ... 1 3 47.9 DEFAULT 48649

48000 1996 2265004010 ... 3 6 47.9 DEFAULT 2417769

48453 1996 2265004010 ... 1 3 47.9 DEFAULT 1737

48453 1996 2265004010 ... 3 6 47.9 DEFAULT 86314

48000 1996 2265004010 ... 6 11 400 DEFAULT 797

48000 1996 2265004011 ... 1 3 268 DEFAULT 1997

48000 1996 2265004011 ... 3 6 268 DEFAULT 99244

48000 1996 2265004011 ... 6 11 400 DEFAULT 33

Figure 6-3: Modified TX.pop file with population estimates for 2-stroke residential lawn mowers in Travis

County (the SCC description, represented with three dots, has been removed from the display for

readability).

With the exception of the FIPS code and the population estimate fields, the additional

population county-level records will be identical to the corresponding state-level

population records.

Note: The county-level equipment populations can be defined in a file other than the (state

name).pop file. However, you must make sure that the name of this new file is listed in

the /POP FILES/ packet of the options file.

4. For each of the allocation indicators that are used, you must next estimate the value of

the indicator within the subcounty of interest. This value should be added to the

appropriate allocation file, using the county FIPS code and the subregion code as the

identifier.

For our example, the allocation indicator that we will use is housing of the Austin

metropolitan area which is estimated to be 112,970. To reflect this for our modeling

scenario, the /INDICATOR/ packet of the housing allocation file for the state of Texas

(nonroad\data\allocate\TX_house.alo) would be modified as shown in Figure 6-4.

HOU 48449 1997 7400

HOU 48451 1997 29554

HOU 48453 1997 159111

HOU 48453Austn 1997 112970

HOU 48455 1997 4576

HOU 48479 1997 27878

HOU 48481 1997 12806

HOU 48483 1997 2609

HOU 48485 1997 40452

Figure 6-4: Modified TX_house.alo file showing housing of Austin.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-27

5. Next, you must modify the /REGION/ packet of the options file to indicate a

subcounty run. Specify Subcounty for the region level and include the list of partial

counties by listing their FIPS code/subregion code pair. Figure 6-5 shows the

/REGION/ packet modified for our example.

The remaining records define the regions to be included.

The type of data which must be specified depends on the

region level.

US TOTAL - Nothing needs to be specified. The FIPS

 code 00000 is used automatically.

50STATE - Nothing needs to be specified. The FIPS

 code 00000 is used automatically.

STATE - state FIPS codes

COUNTY - state or county FIPS codes. State FIPS

 code means include all counties in the 

 state.

SUBCOUNTY - county FIPS code and subregion code.

------------------------------------------------------

/REGION/

Region Level :SUBCOUNTY

 :48453Austn

/END/

------------------------------------------------------

Figure 6-5: Modified /REGION/ packet showing subcounty region.

Note: Before running your subcounty modeling scenario, make sure that the /POP FILES/ and

/ALLOC FILES/ packets of the option file lists the file names of the data files containing

the newly created subcounty data.

6. Once you have completed steps 1 through 5 described above, create an options file

incorporating the modified packets that reflect the subregion data, save the file under

an appropriate name, and run the modeling scenario.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-28

Emission Factors Files Packet

Simply put, emission factors are the rate at which emissions are produced for a particular process. 

In the NONROAD model, the names of the emission factors files for a variety of species and

engine operating modes are contained in the packet identified as /EMFAC FILES/. Similar to the

/RUNFILES/ packet, each filename must be preceded by a keyword. The keyword identifies the

species or operating mode that is contained in the associated data file.

Note: The EPA does not expect users to have local data on emission factors. If you know of a

study on emission factors that was not incorporated into the model inputs, please e-mail

the nonroad modeling team at nonroad@epa.gov

The valid species/modes (keywords) are as follow:

BSFC

THC EXHAUST

CO EXHAUST

NOX EXHAUST

PM EXHAUST

SPILLAGE

DIURNAL

CRANKCASE

HOT SOAKS

RUNNING LOSS

RESTING LOSS

Note: SOX and CO2 emissions are computed as a function of the BSFC factors and adjusted

exhaust hydrocarbons, therefore there is no emission factor file for these species. Vapor

displacement is computed as a function of temperature, RVP, and refueling mode (pump

vs. container) so no emission factor file is required.

As seen in Figure 6-6, these species/modes are contained in separate data files. The file names

can appear in any order in the packet and are identified by the keyword(s). If a species/mode is

not included in an option file, all data for that species/mode will be reported as missing. For

example, if there is no data file for PM emission factors, the PM field of the output data file will

contain all missing values. The exception is BSFC which is a required file. In this version of the

NONROAD, model hot soak emissions, running losses, and resting losses are set to zero in the

output file.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-29

------------------------------------------------------

This is the packet that defines the emissions factors

files read by the model.

------------------------------------------------------

/EMFAC FILES/

BSFC : c:\nonroad\data\emsfac\bsfc.emf

THC EXHAUST : c:\nonroad\data\emsfac\exhthc.emf

CO EXHAUST : c:\nonroad\data\emsfac\exhco.emf

NOX EXHAUST : c:\nonroad\data\emsfac\exhnox.emf

PM EXHAUST : c:\nonroad\data\emsfac\exhpm.emf

CRANKCASE : c:\nonroad\data\emsfac\crank.emf

DIURNAL : c;\nonroad\data\emsfac\diurnal.emf

SPILLAGE : c:\nonroad\data\emsfac\spillage.emf

/END/

Figure 6-6: /EMFAC FILES/ packet.

The spillage data file does not contain emission factors. It simply indicates if a source is a

gasoline pump or a portable container and provides the inputs for tank volume. The equations for

computing spillage and vapor displacement emissions differ for portable containers and gasoline

pumps. Therefore, if the spillage file is not included in the option file then both spillage and

vapor displacement emissions will be reported as missing.

Data Files in the /EMFAC FILES/ Packet

Data files provided with the NONROAD model include:

Filename Description

Bsfc.emf Brake specific fuel consumption factors

Crank.emf Emission factors data for crankcase emissions

Diurnal.emf Emission factors data for diurnal emissions

Exhco.emf Emission factors data for exhaust CO emissions

Exhnox.emf Emission factors data for exhaust NOx emissions

Exhpm.emf Emission factors data for exhaust PM emissions

Exhthc.emf Emission factors data for exhaust THC emissions

Spillage.emf Pump or container specification and tank sizes for gasoline equipment

types

The emission factors files provide the NONROAD model the zero-hour (brand new) engine

exhaust emissions rates and adjustments used to determine evaporative emissions. The emission

factors used in the model are described in EPA’s NONROAD documentation reports NR-009b for

diesel and NR-010c for spark-ignition engines.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-30

The exhaust emission factors files are adjusted for in-use emission rates within the NONROAD

model using the information provided by the deterioration input files. The emission factors are

defined by SCC, power level range, and tech type. The tech types must correspond to those

provided in the tech type files so that the sales fractions of the equipment are matched to an

emission factor. 

Emission factor input file example (up to 10 tech types);

..........

..........

 2200000000 HpminHpmax techtyT1 techtyT2 techtyT3 techtyp4 g/hp-hr NOx

1900 37.7 0 37.7 999.99 /EMSFAC/

..........

..........

 2270002003 750 9999 Base T0 T1 T2 g/hp-hr NOx

1900 9.63 7.94 5.83 3.83

..........

..........

The units of the emission factor and the type of pollutant modeled must be specified. All exhaust

emission factors currently are given in units of grams per horsepower-hour (g/hp-hr) or grams per

mile (g/mile), but there is an option to use grams per hour (g/hr) or grams per gallon (g/gallon)

and the activity rates in the activity file must be altered to match these units. The pollutants

addressed by the exhaust emission factor files may be THC, CO, NOx, or PM, and the file labeled

BSFC.emf provides the fuel consumption factors. (For the fuel consumption file no option is

available for the units and must be in units of pounds per horsepower-hour.) 

In calculating emissions using these files, the model will use the emission factor for the closest

year that is less than or equal to the current model year. The actual emission factors could have

been given specifically for the year in which they are valid, but EPA has chosen to incorporate the

phase-in of emission standards through the use of the tech types rather than in the emission factor

file because it is easier to incorporate phase-in and different deterioration rates using tech types

for new emission standards. In the example above, while the emission factor for Tier 2 diesel

pavers is valid starting in the year 1900, the fraction of Tier 2 engines is nonzero only when the

technology type file shows the phase-in of this standard beginning with the 2006 model year.

The diurnal emission factor input file supplies the NONROAD model the factors in grams/tank

gallon/day for use with the tank volume. The latter is calculated from the average power level

supplied in the population input file multiplied by the tank volume factor supplied in the spillage

input file. The diurnal input file uses the unit (g/tank) to represent the gram per tank volume

gallon per day. The pollutant for diurnal emissions is, of course, THC but it still must be

specified. Multiple tech types may be specified but are not currently used in the current

NONROAD model, which specifies one rate for “ALL” tech types, as seen in the example below.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-31

.............

............. 

 2200000000 HPmn HPmx techtyp1 techtyp2 g/hp-hr THC

/EMSFAC/

 2260000000 0 25 ALL g/tank THC

1900 1.00

 2260000000 25 9999 ALL g/tank THC

1900 1.00

.............

.............

The format for the data in the BSFC and the emission factors files is as follows:

Packet Identifier: /EMSFAC/

Column Description

Line 1: 6 - 15 SCC code (globals can be used)

21 - 25 Beginning of horsepower range

26 - 30 End of horsepower range

35 - 44 Technology type 1

x5 - x4 Technology type 2 ... (repeating field)

x5 - x4 Units 

options: g/hr of equipment use

 g/hp-hr of equipment use

 g/gallon of fuel use

 g/tank per day per gallon of tank volume

 g/day per calendar day

 mult

x5 - x4 Pollutant

Line 2: 1 - 5 Year

35 - 44 Emission factors for technology type 1

x5 - x4 Emission factors for technology type 2 ... (repeating)

Note: The units field is ignored in the BSFC file; the units are lbs of fuel/hp-hr. The units field is

'MULT' in the crankcase file where the emission factor is treated as a multiplier.

The format for the data in the spillage data files is as follows:
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-32

Packet Identifier: /EMSFAC/

Column Description

Line 1: 1 - 10 SCC code (globals can be used)

12 - 20 Refueling mode (PUMP or CONTAINER)

22 - 25 Range indicator (HP or TANK)

27 - 31 Beginning of horsepower range or tank volume range

33 - 37 End of horsepower range or tank volume range

39 - 48 Technology type

 50 - 59 Units (Gallons or Gal/HP)

 61 - 70 Tank size estimate

Deterioration Factors Files Packet

Generally speaking, as a piece of equipment or vehicle ages over time, the rate at which pollutants

are emitted increases. The data in the deterioration input files are used to adjust the emission

factors for in-use deterioration, and the data used in the default files is discussed in EPA’s

NONROAD documentation reports NR-009b and NR-011a. The names of the files which contain

the deterioration factors used by the core model to estimate this increase in emissions are

contained in a packet identified as /DETERIORATE FILES/ (Figure 6-7). Similar to the

/EMFAC FILES/ packet, each filename must be preceded by a keyword. The valid species/modes

are the same as for the /EMFAC FILES/, with the exception that BSFC and SPILLAGE are not

recognized.

------------------------------------------------------

This is the packet that defines the deterioration factors

files read by the model.

------------------------------------------------------

/DETERIORATE FILES/

THC EXHAUST : c:\nonroad\data\detfac\exhthc.det

CO EXHAUST : c:\nonroad\data\detfac\exhco.det

NOX EXHAUST : c:\nonroad\data\detfac\exhnox.det

PM EXHAUST : c:\nonroad\data\detfac\exhpm.det

/END/

Figure 6-7: /DETERIORATION FILES/ packet.

Note: The EPA does not expect users to have local data on deterioration factors. If you know of

a study on deterioration factors that was not incorporated into the model inputs, please email the nonroad modeling team at nonroad@epa.gov
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-33

Data Files in the /DETERIORATE FILES/ Packet

The deterioration factors are specified by technology type. An “ALL” in the technology type field

indicates that the deterioration factors apply to all technology types. The values are actually the

coefficients of the deterioration equation 

DF = 1 + A × engine ageb ,

where A and b are provided in the file. The input file also provides a cap on the deterioration, to

prevent further deterioration past a certain relative age. A sample of the look and estimates in a

deterioration file is shown in the example below.

.........

.........

Tech Type A coeff b coeff Age Cap Pollutant

/DETFAC/

.........

.........

Base 0.024 1.0 1.0 NOx

T0 0.024 1.0 1.0 NOx

T1 0.024 1.0 1.0 NOx

T2 0.009 1.0 1.0 NOx

T3 0.008 1.0 1.0 NOx

.........

.........

Data provided with the NONROAD model include:

Filename Description

Exhco.det Deterioration factors data for exhaust CO emissions

Exhnox.det Deterioration factors data for exhaust NOx emissions

Exhpm.det Deterioration factors data for exhaust PM emissions

Exhthc.det Deterioration factors data for exhaust THC emissions

The format for the data in deterioration factors files is as follows:

Packet Identifier: /DETFAC/

Column Description

1 - 10 Technology type

21 - 30 A coefficient of equation

31 - 40 b coefficient of equation

41 - 50 Emission Cap (in median life units)

51 - 60 Pollutant
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-34

PM Base Sulfur Packet

The /PM BASE SULFUR/ packet contains diesel sulfur weight percents corresponding to the

input diesel PM emission factors for each diesel technology type. The default is 0.3300 (3300

ppm), but Tier 2 and later diesel emission factors are based on lower sulfur fuel. These values are

used by the model to adjust the calculated diesel PM emissions for in-use sulfur levels that differ

from these base sulfur levels. For the details of this adjustment refer to technical report NR-009b,

"Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling -- CompressionIgnition." As with the emission factor inputs, EPA does not expect users to have local data, and

users are not expected to change anything in this packet.

The format for this data is as follows:

Packet Identifier: /PM BASE SULFUR/ 

Column Description

1 - 10 Diesel technology type

11 - 20 Base sulfur wt percent; or '1.0' means no-adjustment

The default values contained in this packet are as follows:

/PM BASE SULFUR/ 

T2 0.2000 

T3 0.2000 

T4 0.0015 

T4N 0.0015 

/END/

The technology types, “T4" and “T4N,” are placeholders for potential future standards and are not

used in this version of the model.

EDITING INPUT DATA PACKETS AND FILES

For an advanced user of the NONROAD model, the process of incorporating locally-derived data

into the core model is relatively straightforward. To make changes to the data files, simply use a

text editor such as Microsoft’s Notepad or WordPad, or the Edit command in DOS, to access the

data file. Once you have accessed the data file that you want to change, type the revised data in

the appropriate field. Once complete, save the modified file under a new name to prevent the

overwriting of default data.

Note: When the NONROAD model is initially installed, all data files are in a subdirectory called

Data in the Nonroad directory.
December 2002 December 2002

EPA NONROAD Emissions Model User’s Guide 6-35

There are two methods for indicating that you want to use new data files in an option file. The

first is through the Advanced Options menu in the graphical user interface which is described in

Chapter 3. The second is by modifying the appropriate packets in the option file through a text

editor.

MAKING MULTIPLE MODEL RUNS

Through a text editor or DOS, you can create a batch file that allows you to run the core model

with many different scenarios. This capability provides you with the flexibility of setting up and

running these scenarios when you have available computer time, such as in the evening. Figure 6-

8 shows the batch file milg.bat (for Michigan lawn and garden run).

nonroad milg95.opt

nonroad milg96.opt

nonroad milg97.opt

nonroad milg98.opt

Figure 6-8: Batch file milg.bat.

A batch file can be easily created with a text editor. Open a text editor and simply type “nonroad

(option file).opt” on consecutive lines for each of the option files you want to run. Save the batch

file and close the editor. It is recommended that you name the file with a relevant name and the

extension .bat.

To run a batch file in DOS, type “(name of your batch file).bat”. From Windows 3.1, use File 

Run. Type the name of your batch file in the dialog box and specify OK. From Windows 95,

drag the mouse to the menu bar and Start  Run. Type the name of your batch file in the

dialog box and specify OK.
December 2002

EPA NONROAD Emissions Model User’s Guide 7-1

Chapter 7 Trouble Shooting

The NONROAD model does extensive validation of input data. Data initialization includes

checking that each required input packet exists in the input option file and that the specified data

values are within acceptable ranges. If the model detects unreasonable data, an error message is

written and the program terminates. Specified data files must exist and include the necessary data

elements. The messages written by the model are generally sufficient in determining where a

problem exist.

MESSAGE FILE

The output message file should be reviewed after each model run. An example of an output

message file is shown in Figure 7-1.

This file includes the NONROAD model title and version number, date and time of execution,

and a summary of each packet in the input option file. In addition, warning messages may be seen

informing you of possible problems. Consider the message, “WARNING: Cannot find

/DETERIORATE FILES/ packet of the options file. Factors for all species will be set to 1.0 (no

deterioration).” You may determine that this is acceptable to you for your application. However,

you may also want to review your data to determine if you can provide additional information.

In general, warning messages allow the model to make generalizations and provide a default

action if a data item is not found; this includes skipping some records. It is important to note that

although default action can occur it is meant to be the exception. Therefore, if the model issues

the same warning message more than 50 times it will terminate processing. This ensures that

lengthy runs will not process invalid data (remember, defaults are the exception).
December 2002

EPA NONROAD Emissions Model User’s Guide 7-2

 EPA`s NONROAD Emissions Model, Core Model Ver 2.1d, Mar 2002 May 23 10:29:20:

2002 

 *** Output Files ***

 Output data file :c:\nonroad\outputs\travis.out

 *** Input Files ***

 Options file :C:\EUDORA\ATTACH\TRAVIS.OPT

 Allocation XREF file:c:\nonroad\data\allocate\allocate.xrf

 Activity file :c:\nonroad\data\activity\activity.dat

 State/Regions file :c:\nonroad\data\season\season.dat

 Seasonality file :c:\nonroad\data\season\season.dat

 Tech fractions file :c:\nonroad\data\tech\tech.dat

 *** Population Files ***

 :c:\nonroad\data\pop\tx.pop

 *** Emission Factors Files ***

 BSFC file :c:\nonroad\data\emsfac\bsfc.emf

 THC EXHAUST file :c:\nonroad\data\emsfac\exhthc.emf

 CO EXHAUST file :c:\nonroad\data\emsfac\exhco.emf

 NOX EXHAUST file :c:\nonroad\data\emsfac\exhnox.emf

 CO2 EXHAUST file : Not Supplied.

 SOX EXHAUST file : Not Supplied.

 PM EXHAUST file :c:\nonroad\data\emsfac\exhpm.emf

 CRANKCASE file :c:\nonroad\data\emsfac\crank.emf

 HOT SOAKS file : Not Supplied.

 DIURNAL file :c:\nonroad\data\emsfac\diurnal.emf

 REFUELING file : Not Supplied.

 SPILLAGE file :c:\nonroad\data\emsfac\spillage.emf

 RUNINGLOSS file : Not Supplied.

 RESTNGLOSS file : Not Supplied.

 *** Deterioration Factors Files ***

 THC EXHAUST file :c:\nonroad\data\detfac\exhthc.det

 CO EXHAUST file :c:\nonroad\data\detfac\exhco.det

 NOX EXHAUST file :c:\nonroad\data\detfac\exhnox.det

 CO2 EXHAUST file : Not Supplied.

 SOX EXHAUST file : Not Supplied.

 PM EXHAUST file :c:\nonroad\data\detfac\exhpm.det

 CRANKCASE file : Not Supplied.

 HOT SOAKS file : Not Supplied.

 DIURNAL file : Not Supplied.

 REFUELING file : Not Supplied.

 SPILLAGE file : Not Supplied.

 RUNINGLOSS file : Not Supplied.

 RESTNGLOSS file : Not Supplied.

 *** Spatial Allocation Files ***

 :c:\nonroad\data\allocate\tx_rvprk.alo

 :c:\nonroad\data\allocate\tx_golf.alo
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EPA NONROAD Emissions Model User’s Guide 7-3

 :c:\nonroad\data\allocate\tx_airtr.alo

 :c:\nonroad\data\allocate\tx_const.alo

 :c:\nonroad\data\allocate\tx_farms.alo

 :c:\nonroad\data\allocate\tx_holsl.alo

 :c:\nonroad\data\allocate\tx_house.alo

 :c:\nonroad\data\allocate\tx_loggn.alo

 :c:\nonroad\data\allocate\tx_lscap.alo

 :c:\nonroad\data\allocate\tx_mnfg.alo

 :c:\nonroad\data\allocate\tx_oil.alo

 :c:\nonroad\data\allocate\tx_pop.alo

 :c:\nonroad\data\allocate\tx_sbr.alo

 :c:\nonroad\data\allocate\tx_sbc.alo

 :c:\nonroad\data\allocate\tx_snowm.alo

 :c:\nonroad\data\allocate\tx_wob.alo

 :c:\nonroad\data\allocate\tx_wib.alo

 :c:\nonroad\data\allocate\tx_coal.alo

 *** Growth Indicator Files ***

 :C:\nonroad\data\growth\nation.grw

 *** Scenario Specific Parameters ***

 First Title line :LAWN AND GARDEN EQUIPMENT

 Second Title line :TRAVIS COUNTY SUMMERTIME

 Fuel RVP (psi) : 8.00

 Fuel Oxygen weight %: 0.00

 Gasoline Sulfur % : 0.0340

 Diesel Sulfur % : 0.3300

 LPG/CNG Sulfur % : 0.0030

 Minimum Temperature : 60.00

 Maximum Temperature : 80.00

 Average Ambient Temp: 75.00

 Altitude of region :LOW 

 Stage II Control % : 0.00

 *** Period Parameters ***

 Year of Inventory :1998

 Inventory for :SEASONAL period

 Emissions summed for:PERIOD TOTAL

 Season :SUMMER

 *** Region of Interest ***

 Region level : County-level estimates

 Counties of Interest

 :48453 - Travis County, Texas

 *** Equipment Types ***

 SCC codes Selected

 :2260004010

 :2265004010

 :2267004010

 :2268004010

 :2270004010
December 2002

EPA NONROAD Emissions Model User’s Guide 7-4

   Number of Population Records Found ** **

 48000 Texas : 3

Figure 7-1: Output message file.

DATA FILE RELATIONSHIPS

One of the difficulties a novice user may have is understanding the relationships between different

input files. The following is an example of possible problems as a result of providing some new

data but not enough.

Allocation Files

The allocation cross reference file defines for each source category the allocation indicator and a

corresponding coefficient to be used to allocate equipment population. If you have local data on

the use of snowmobiles in your modeling domain you can specify a new indicator code and then

provide the allocation data for the new code. For example, by adding 2260001020, recreational

snowmobiles, with an indicator code of SNO to the allocation cross reference file means you

must provide an allocation file for the SNO indicator.

In addition, you must remember to update the options file to reference the new files and data

which you have created. The packet /ALLOC FILES/ must include the new allocation filename

for the SNO indicator data. And if you made changes to a copy of the cross reference file you

must be sure to specify the new cross reference file name in the /RUNFILES/ packet of the

options file (perhaps alloupd.xrf).

Population Data

The equipment population data can contain records of any or mixed region levels and the model

will use the most detailed provided. If you want to estimate county total emissions, then you can

either provide state level equipment populations and state-to-county allocation data or you can

provide county equipment populations. If equipment population is provided at the level for which

emissions are being reported then, no allocation is needed. Only when equipment populations are

provided at a coarser level of detail than the level you are estimating will allocation data be

required. 

In addition to defining equipment populations and corresponding allocation data you must also

include the data file names in the /POP FILES/ and /ALLOC FILES/ packets of the input option

file.