Draft of June 3, 1998 Federal Register Notice


                ENVIRONMENTAL PROTECTION AGENCY
                                                
                    [AMS - FRL - _____ - __]
                                                
                     Air Pollution Control;
       Nonroad Vehicle and Equipment Emission Inventories
                                

AGENCY:   Environmental Protection Agency (EPA)

ACTION:   Notice of Public Workshop

SUMMARY:  The Environmental Protection Agency is now in the
process of developing a nonroad mobile source emissions inventory
model (the NONROAD model). This notice announces a public
workshop for the purpose of discussing the various issues
involved in creating a model for this diverse collection of
vehicles and equipment that comprise the nonroad mobile source
sector, and provides a formal opportunity for comment and
reaction to the release of the draft NONROAD model and its
associated technical documentation.  This notice also announces a
hands-on demonstration of the model immediately following the
public workshop. 

DATES:  The workshop will be held Thursday, June 25, 1998.  The
times are from 8:30 am to 4 pm.  A demonstration of the NONROAD
model will be held on the same day from approximately 4:30 pm to
5:30 pm.  All times are Central Daylight Time.

ADDRESSES:  The workshop will be held in the Metcalf Federal
Building, 17 West Jackson Blvd., Chicago, IL, Lake Michigan and
Lake Ontario Room- 12th, Great Lakes Conference and Training
Center.  The Metcalf building is located in the heart of the
downtown area.  The model demonstration will be held at the same
location.  Directions to the workshop and model demonstration can
be obtained through the EPA OMS World Wide Web (WWW) site, or
otherwise requested from the EPA contact person.  Information on
how to electronically access the web site or on the EPA contact
person appears immediately below.

FOR FURTHER INFORMATION CONTACT:  Ms. Gertrude Venlet, U. S. EPA
Office of Mobile Sources, Assessment and Modeling Division,
Scientific Assessment Group, 2000 Traverwood Drive, Ann Arbor MI
48105. 
Telephone:   (734) 214-4892; fax (743) 214-4939.
Email:  nonroad@epa.gov

This notice, as well as related information concerning the
workshop, may be found at the EPA OMS web site.  The electronic
address for this site is:

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


Workshop-related files, including a copy of this notice,
additional information on the location of the workshop and model
demonstration, hotels, technical reports, the draft NONROAD
model, and later additional information that may become available
as described in the body of this announcement, will be found at
the wet site location or may otherwise be obtained from the EPA
contract person.

SUPPLEMENTARY INFORMATION:

Background

Nonroad mobile sources are a significant source of air pollutants
in many areas of the United States.  This broad category is
comprised of a diverse collection of vehicles and equipment,
including vehicles and equipment in the following nine
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.

Current nonroad inventory development practices are based on
EPA's Nonroad Engine and Vehicle Emissions Study (NEVES), done
under the 1990 Clean Air Act Amendment requirements, and
"Procedures for Emission Inventory Preparation, Volume IV: Mobile
Sources (EPA-450/4-81-026d (revised), 1992). In consideration of
the increased recognition of the importance of emissions from
nonroad sources in terms of overall emissions and air quality,
and the considerable practical difficulty of implementing the
current guidance, EPA is developing a nonroad emissions inventory
model (NONROAD) to meet the needs of the modeling audience.  

NONROAD Emission Inventory Model

EPA has completed a draft version of NONROAD, an accompanying
detailed user's guide, and a number of technical reports
describing the model's data inputs and assumptions.  This version
of the model covers all nonroad vehicle and equipment types,
except aircraft, locomotives, and commercial marine.  The Agency
will develop modeling modules for aircraft and locomotives
sometime in the future.  As for commercial marine, a module for
this source category is under construction and will be released
for public review later this year.  

The draft model is intended to easily create and project
accurate, reproducible inventories of nonroad emissions.  It has
a number of uses, but should be especially important to state and
local pollution control agencies in satisfying the State
Implementation Plan (SIP) requirements of the Clean Air Act
Amendments of 1990. 

Structurally, the model is made up of three specific components:
a graphical user interface (GUI) which allows the user to easily
input model parameters, the core model which contains all
computational algorithms, and a reporting utility for viewing and
summarizing modeled emissions estimates.  The model has been
designed to allow the user a high degree of flexibility.  As
such, the model will:

     -    Calculate and report emissions in total for the United
     States, and for individual states and counties.

     -    Calculate emissions for a variety of time periods (e.g., an
     entire year, any particular month, any combination of
     months, or daily weekday or weekend day).

      -   Report emissions of six pollutants:  hydrocarbons (HC),
     carbon monoxide (CO), NOx, sulfur oxides (SOx ), and PM.  The
     model will report both exhaust and non-exhaust HC emissions,
     the latter of which includes crankcase, diurnal, refueling,
     etc.

     -    Estimate current and future year emissions in a specified
     geographic.  In estimating future year emissions, the model
     includes growth and scrappage and can accommodate a variety
     of control program options.

     -    View model results in different formats such as an Emission
     Pre-Processor System 2 (EPS-2) input file, spreadsheet, and
     preformatted reports.

The public workshop being announced today provides a valuable
opportunity for EPA to receive assistance in developing the final
NONROAD model through review and comment by all interested
user's.  The workshop will focus on all aspects of the model
including user convenience, data inputs and modeling assumptions,
computational structure, and reporting options and formats. 
Presentations on each subject will be followed by a short
discussion/question and answer period, and there should be some
time left at the end of the day for more general open discussion
of the material that has been presented.  A more detailed draft
agenda for the workshop will be posted on the EPA OMS web site or
may be obtained by from the EPA contact person (see FOR FURTHER
INFORMATION CONTACT).  

Availability of Technical Reports and NONROAD

EPA anticipates the workshop will be highly interactive.  To
facilitate this goal, all participants are encouraged to review
the draft technical reports on data inputs and assumptions, as
well as the draft NONROAD model and accompanying user's guide. 
These documents and the model are posted on the EPA OMS web site
or are otherwise available on CD ROM from the EPA contact person 
(see FOR FURTHER INFORMATION CONTACT).  Please visit this site
often to check for additional information or model documentation
which may be posted between now and the workshop date.

Comment Period

The Agency is providing a 60-day public comment period on the
draft model and associated documents.  This period should be
adequate for interested parties to thoroughly review the
available information, and is consistent with the guidelines for
public review of EPA emission models the Mobile Sources Technical
Review Subcommittee of the Clean Air Act Advisory Committee
established under the Federal Advisory Committee Act.  The
comment period will be initiated at the time the draft NONROAD
model is posted on the EPA OMS web site.  

Model Demonstration

The Agency will hold a hands-on demonstration of the model on the
same day, at the same location immediately after the public
workshop.  The facility is capable of seating approximately 20
people at individual personal computers.  This demonstration will
be held on a first come, first serve basis.  Please contact EPA
via the NONROAD E-mail box or the EPA contact person (see FOR
FURTHER INFORMATION CONTACT).

Additional Information

To the extent possible, EPA will post material at the EPA OMS web
site, as described under "FOR FURTHER INFORMATION CONTACT," in
advance of the workshop.  Those planning to attend, and those
interested in following the progress of workshop planning more
closely, should periodically visit the EPA OMS web site. 


______________     __________________________________________
    Dated                      Richard D. Wilson, 
                        Acting Assistant Administrator
                         Office of Air and Radiation
