United States
                           Environmental Protection
                             Office Of Air Quality
                             Planning And Standards
                             Research Triangle Park, NC 27711
Volume VI, No. 3
Summer 1995
                           THE  CHIEF
                           THE LONG-AWAITED FIFTH EDITION
                 The Fifth Edition of the EPA's all time "best
   seller" is now available. The 2,050-page Compilation Of
Air Pollutant Emission Factors, Vol. I:  Stationary Point
And Area Sources, AP-42, comes after months of work incor-
porating, revising and expanding all previous editions and
supplements of a document  series older than the  Agency
itself. This series is so familiar in air pollution work that it is
usually called just AP-42, its document number. It is a valu-
able technical resource for inventorying air pollutant emis-
sions, developing control regulations, and other source as-
sessment activities. Its wide array of users includes federal,
state and local agencies; business and industry; and engi-
neering consultants, lawyers, and academics.
    A paper copy of this book canbe ordered from the Gov-
ernment Printing Office (GPO), Box 371954, Pittsburgh, PA
15250-7954, Stock no. 055-000-00500-1, $56.00 total. Foreign
orders add 25%. Telephone orders to (202) 512-1800, fax or-
ders to (202) 512-2250.
    CHIEF Newsletter readers know that this document has
been on our CHIEF bulletin board system (BBS) for some
weeks, and during this time it has set new records for down-
loads, averaging 3,700 per week!  It is by far the most popular
item on the Office Of Air Quality Planning And Standards
(OAQPS) Technology Transfer Network (TTN). AP-42 is also
available from our quick-response automated facsimile ma-
                         chine, the Fax CHIEF, (being accessed now
                         about 250 times per week!).  To register for the CHIEFBBS,
                         phone through your modem (919) 541-5742. To use the Fax
                         CHIEF device, phone through yourfax handset (919) 541- 5626
                         or -0548. For assistance, call the Info CHIEFhelp desk, (919)
                             AP-42 is available from GPO on a compact disc (CD-ROM),
                         Air CHIEF, with other air pollution control guidance and data
                         bases, at the above address/phone numbers, Stock no. 055-000-
                         00501-0, $18.00 total. Foreign orders add 25%.
                             The Emission  Factor  And Inventory Group (EFIG), in
                         OAQPS, develops and maintains the AP-42  series and other
                         useful emission estimation tools.  Although the Compilation
                         Of Air Pollutant Emission  Factors has been in use for about 30
                         years, it has been especially important in meeting requirements
                         of the 1990 Clean Air Act Amendments and the 1986 Emer-
                         gency Planning And Community Right-To-KnowAct.
                             The compilation provides detailed information on hundreds
                         of processes that produce criteria, toxic, or greenhouse pollut-
                         ants. For all these activities, from gasoline tankers, steel mills,
                         and forest fires to potato chip frying and dry cleaners, AP-42
                         tabulates emission factors, which are representative values used
                         to estimate the quantities  of pollutants those processes will
                         release into the air.  AP-42 contains over 10,000 such factors,
                         with references and factor quality ratings.
                                       ADOPT-A-FACTOR UPDATE

    It made it! A $4.5 million budget item for section 105 Grants to the states made it through the process and will be included in
the FY 96 grant negotiations. States will share in this "pot" of funds according to a fairly standard allocation process and will be
provided these funds on thebasis of their agreement, need, abilities, etc. to develop emission factors that they need.  We envision
states pooling their funds, getting assistance from their academic institutions, contractors, etc., to undertake testing and/or
emission factor development for sources where there is a high priority and need. Ideally, a few "centers of excellence" could be
established in three or four areas of the country to focus on development of factors, with the grant funds being channeled to them
for this work by the states in those areas. Additional guidance and information of this program will be coming from the EPA
Headquarters and from Regional Offices, in the next several weeks. Keep tuned to the CHIEFBBS for any late developments.
The success of the program in the first year may be essential to continuing the work as the "strings" to these monies will likely
loosen in FY97 and beyond with "block grants" (or "performance partnerships" as they may be called).

       Here are some hot topics with information on each.
Q: What is the latest hard copy of the AIRS SCC listing, and
how can I get it?

     A: Good timing! This information is in the new FIRE
Version 5.0 Source Classification Codes And Emission
Factor Listing For Criteria Air Pollutants, EPA-454/
R-95-012, August 1995. Paper copies of this book will be
available, and it will be on the CHIEFBBS, very shortly,
perhaps by the time you read this.
    If you need to get only SCCs without the emission factors,
you can search directly on the 'CHIEF BBS by selecting "SCC
Lists" (letter "Q") from the main menu and then typing in a
keyword phrase. This is a quick and easy way to get the SCC
that you need. You can also  search by SCC to find the SCC
name associated with it. In addition, under this same section,
there is a downloadable list of SCCs and SCC names which may
be imported into a database or word-processing program and
then printed out.

Q: I thought the Fifth Edition of AP-42 was supposed to be
completely revised, but there are sections that are listed as
"not yet available" on Fax CHIEF wA "work in progress" on
the CHIEF BBS.  When will these sections be available to the
                                 A: These sections of AP-42 are either undergoing major revi-
                                 sion or will be brand new sections added to the document. Sec-
                                 tion numbers have been reserved and these sections will ap-
                                 pear in the AP-42 supplements which are generally published
                                 annually. The first Fifth Edition supplement is expected to be
                                 available by January 1995, but not all  of these "in progress"
                                 sections will appear in the first supplement.  Contact/w/o CHIEF
                                 if you have questions regarding the status of any particular "in
                                 progress" AP-42 section.

                                 Q: When will the Locating & Estimating (L & E) document
                                 for dioxins and furans be available? How can I get it?

                                 A: Locating & Estimating Air Emissions From Sources Of
                                 Diaxins And Furans is currently available in
                                  SULFUR DIOXIDE EMISSION TRENDS"
    A Report To Congresson national annual industrial sulfur dioxide (SO2) emission trends was released in June. This report
is the first ina series entitled "National Annual Industrial Sulfur Dioxide Emission Trends, 1995-2015," to be published every 5
years beginning in 1995. This report is required under Title IV, section 406, 42 USC 765 l(note), of the 1990 Clean Air Act
Amendments (CAAA).
    Section 406 of the Act requires the Administrator to transmit to the Congress a report containing an inventory of national
annual industrial sulfur dioxide emissions for all years for which data are available, as well as the likely trend in suchemissions
over the following 20-year period. Industrial source is defined in Title IV of the Act to be a unit that does not serve a generator
that produces electricity, a unit other than a utility unit, or a process source, which is any source that emits SO2 as the result of
the production or manufacturing process and not as the result of any type of fuel combustion.  The report shall also contain
estimates of the actual emission reduction each year resulting from promulgation of the diesel fuel desulfurization regulations
under section 21 l(i).
    Section 406 also provides that whenever the required inventory indicates that SO2 emissions from industrial sources,
including units subject to section 405(g)(6) of the CAAA, may reasonably be expected to reach levels greater than 5.60 million
tons per year, the Administrator shall take such actions under the CAAA as may be appropriate to ensure that such emissions
do not exceed 5.60 million tons per year.  Such actions may include the promulgation of new and revised standards of perfor-
mance for new sources, including units subject to section 405(g)(6) of the CAAA, under section 11 l(b) of the CAAA, as well as
promulgation of standards of performance forexisting sources, including units subject to section 405(g)(5) of the CAAA.
    This document reports an estimated 15 percent decrease from the 5.6 million ton cap over the period 1985 to the present, and
it projects approximately a 2 percent increase for the 20-year period between 1995 and 2015 (from 4.77 to 4.86 million tons). This
analysis demonstrates that the 5.6 million ton cap for industrial sources of SO2 will not be violated through 2015, thus no further
regulatory action is needed.
    The following chart chronicles the trends from 1990 to 2010.  For copies of this report, contact the National Technical
Information Service, (800) 553-6847, or/w/o CHIEFat( 919) 541-5285.
    Estimates (million short ton
       1 900
                             HM&MM                  I    I                  I    I

    At its September 1991 semiannual meeting, the joint EPA/
STAPPA/ALAPCO/SAEWG group requested that EPA pursue
a program to improve and refine the emission inventory prepa-
ration process.  The resulting program, the Emission Inventory
Improvement Program (EIIP), is a cooperative effort among state
and local agencies, industry, and EPA to improve estimates of
emissions from various sources.  The effort, funded by state
and local agencies, began in 1993. EIIP is organized  into a
steering committee and seven working committees. Each work-
ing committee, comprising state and local agency members,
industry association representatives, and EPA, is developing
standard procedures for estimating emissions.
    Based on experiences gained during compilation  of the
1990 inventory, it was recognized that interpretation of existing
procedures and guidance allowed too much variation in most
aspects of data compilation (e. g., formats and data accuracy).
This leeway in selecting approaches led to the use of data sets
of unknown quality and varying degrees of completeness in
making decisions. Deficiencies and inconsistencies in present
compilation processes emphasize the need fordeveloping and
implementing more uniform and systematic approaches  to col-
lecting and reporting data.
    The EIIP effort to develop standard procedures supports
this goal. EIIP (defined as the development and use of stan-
dard procedures for collecting, calculating, storing, and report-
ing of emissions data) has been designed to increase the  likeli-
hood that acceptable quality emission inventory data will re-
sult. These data will be made available to state and local agen-
cies, the regulated community, the public, and EPA. The use of
 EIIP procedures will promote consistency in these activities
among the emission inventory reporting groups.
    The overall intent of the EIIP is to provide cost-effective,
reliable inventories by improving the quality of collected emis-
sion data and by providing for uniform reporting of this infor-
mation.  The effort is to develop a systematic mechanism for
compiling emission  inventories patterned after successes
achieved by similar national programs.
    EIIP has made significant progress since its inception in
1993. Standardized procedures have been developed for point
and area sources. Final drafts for many of the documents are
available for external review, and the new biogenic model has
been documented and inputs described. A comprehensive Q A/
QC document is also in preparation. Additionally, a core data
model is being developed to facilitate data exchange between
all members  of the inventory community. The model will de-
scribe data elements and their relationship to each other.  This
model, the resulting data formats, and the use of electronic data
transfer will all enable easy exchange of data.
    EIIP is always seeking qualified reviewers to examine draft
documents for accuracy and consistency. These drafts can be
obtained from the authors or can be downloaded from CHIEF
    It is the vision of EIIP that all governmental agencies and
all industries will adopt EIIP procedures for collecting and re-
porting emissions data. As the draft procedures are completed,
reviewed, and approved by EIIP, everyone is encouraged to
begin using the procedures.
    (See accompanying article on page 5.)
    EPA's Office Of Mobile Sources (OMS) has issued Highway Vehicle Emission Estimates — II, May 1995, in response to
concerns that highway vehicle emission factor models, such as EPA's MOBILE series, were underestimating emissions. Tunnel
studies, roadside measurements, and ambient concentration analyses have provided "suggestive but not definitive" evidence
that existing emission factor models and inventory development procedures have led to understatement of the actual total
emissions contribution of highway vehicles.
    This publication continues the correction efforts begun in the companion book of July 1992, Highway Vehicle Emission
    OMS has been aware that several parts of existing practice needed improvement.  Some of these were dealt with in 1993 in
the MOBILESa modeling program, while others will take longer to address. The two publications discuss the
Agency's pre-1990 approach to estimating vehicle emissions, the known limitations of that approach,
other possibly contributing issues, and what EPA has done and will do to address the problem.
    Highway Vehicle Emission Estimates — II provides new information on a number of
problems dealing with emission factors and inventory procedures.  It is intended to pro-
vide an overview of the subject and to facilitate discussion. It is not a statement of
EPA policy.
     Copies of the paper are available from, and comments welcomed by, Terry
Newell (AQAB), EPA Office Of Mobile Sources, National Vehicle And Fuels Emis-
sion Laboratory,  2565 Plymouth Road, Ann Arbor, MI 48105. This issue paper is
also on the OMS portion of the OAQPS TTN.

                                            EIIP DATA MODEL

         (Information on the Emission Inventory Improvement Program - its mission, its scope, and its membership - can
     be found on the CHIEF BBS, under the EIIP Section. Also available are monthly progress reports from each subcom-
     mittee.  See the general EIIP article on page 4.)

    The EIIP Data Management Committee is developing a data model that will result in a standard data format for exchanging
emission inventory data. The data model is being constructed based on input provided by the EIIP, point, area, mobile, biogenic,
and quality assurance subcommittees.
    The approach taken with the EIIP data model includes some provision for flexible data entities and attributes, thereby making
the model amenable to updates in an efficient, timely, and cost-effective manner. It is expected that this approach will fit well with
state/local users who convert to the data format from relational databases. The data model is being developed in three phases.
The current Phase 1 will result in a core data model and data format that are adequate for use in regional modeling and that will
facilitate transfer of those data from state/local agencies to EPA, or among state/local agencies. Phase 2 is to further enhance the
core model to include data from program areas that overlap the emission inventory area, such as Title 5 permits, Title 3 toxics, and
compliance related data. Some Phase 2 input is occurring concurrently with Phase 1. Phase 3 is envisioned to enhance the core
model to reflect a more complete and integrated transfer of emissions inventory data from facilities to state/local agencies. State
and local agency support/direction will be emphasized and confirmed through STAPPA/AL APCO before completing Phase 2 and
before starting Phase 3.
    The Phase 1 core data model is scheduled for external distribution and review in August. That external review will focus on
the larger EIIP community (which most likely includes everybody reading this article) to validate that the coverage is adequate to
conduct regional modeling and that the resulting data format is practical as a standard for exchanging emissions data within the
community.  Anyone who would like to be involved inthis valuable peer review, please consult the EIIP section of the CHIEF
BBS during August for a notice of its availability and the review logistics.
    Numerous state, local, and industrial EIIP representatives are to be commended for their participation and perseverance in
making this data model happen. There are the typical "rough spots" that come with trying to get work done by committee, but the
strength of the project appears founded in the participants' unified motivation and their belief that improvements in data transfer
can be demonstrated and recommended for the benefit of the emission inventory community. The EIIP Steering Committee, which
is representative of the STAPPA/AL APCO emissions inventory work group, plans to launch a campaign to inform the inventory
community of the recommended dataformat, of datatransfertechniques, and other EIIP advancements in the EIIP. In support of
this momentum, the FY96 distribution of section 105 grant funds to the regions includes allocation for an emission inventory data
delivery project. These are funds intended to improve the sharing of emissions inventory data among  states and EPA, with
STAPPA/AL APCO providing guidance and direction through EIIP and focusing on EIIP data sharing objectives and techniques.

        Recently, John Seitz, OAQPS Director, was pre-
     sented with his own autographed copy of the  Fifth
     Edition of the Compilation of Air Pollutant Emission
     Factors, AP-42. He was astonished at the sheer vol-
     ume of the 2,050-page document and expressed his
     appreciation for all the work that it represents. The
     Fifth Edition is available on the CHIEFBBS (and has
     been the major source of activity on the OAQPS Tech-
     nology Transfer Network for several weeks), on the
     Fax CHIEF, and in paper from the Government Print-
     ing Office (GPO) for $56.00. It will also be part of the
     new version 4.0 Air CHIEF CD-ROM, to be available
     from GPO in Augustfor $18.00. Call GPO, (202)512-
     1800, to order or Info CHIEF, (919) 541-5285, formore

    Four reports related to the development and comple-
tion of the surface coal mine study required by Section
234 of the Clean Air Act have recently been printed. The
fourth, and major, report is on the field studies foremis-
sion factor development, which took place in Wyoming
over several months. Although this report contains pre-
liminary revised emission factors, the emission factors
from the study will not be final until validation of the
factors and modeling work are validated. We continue to
work with the mining interests and others to refine the
results. A work assignment with Midwest Research In-
stitute is currently active to finalize these factors in the
form of an AP-42 section revision, hoped for by the end
of September of this year. Jim Southerland is the work
assignment manager forthis effort.

        OTC  ESTABLISHES  1990 NO

    On September 27,1994, the 13 states composing the Ozone
Transport Commission (OTC) created the foundationfora re-
gion-wide market-based program of NOX emissions trading by
agreeing to control NOX emissions from those boilers and other
indirect heat exchangers with a maximum gross heat input rate
of at least 250 million BTU per hour.  Since NOxreductions will
be calculated as a percent decrease from a baseline year (1990),
the first step for meeting the national standard for Ozone is to
establish an accurate baseline NOX emission inventory for the
period of May - September 1990.  Emissions for this period
have been compiled and will be used as a basis for emission
reduction targeting and trading.  OTC produced a procedures
document in December of 1994 that described the process for
completing the inventory, including quality assurance, calcula-
tion of five-month emissions, selection of emission factors, and
determining exceptional circumstances (an exceptional circum-
stances data base was developed in 1990 to cover atypical
    The 13 OTC states faced much work to do in a very tight
time frame (the final inventory was due March 1,1995) and no
central authority in a loose group of 13 states.  Facing these
constraints, EPA's strategy was to provide structure to the pro-
cess and facilitate the task by
    (1) making EPA technical expertise available to the OTC
       states to expedite the development of the baseline
    (2) coordinating weekly conference calls among EPA and
       the states,
    (3) communicating quickly, frequently, and freely along
      the way with states, industry, and the environmental
      community (using the OAQPS TTN and overnight
    (4) facilitating data quality assurance by assimilating and
       sorting state data bases quickly, and
    (5) letting the states make decisions.
    The commission voted on June 13,1995, to accept the final
baseline inventory and to forward it to EPA for approval. This
inventory is not perfect, but it is an agreed-upon (by both in-
dustry and states) starting point on which the NOX emission
reductions can be calculated.
    The CHIEFBBS contains the QA document describing
the  criteria for accepting and quality assuring the data, the
OTC NOXbaseline  inventory (in a database format), and a
spreadsheet summary of the NOX inventory.
    For more information on this topic, contact Roy Huntley,
of EFIG, (919) 541-1060.
                                            EMISSION ESTIMATION TOOLS COURSE
                                                        IN SAN ANTONIO

                                               Anne Pope and Jim Southerland (EPA) and An-
                                           gela Andrews (Lockheed Martin) presented a one-
                                           day course to 18 students at the Air & Waste Man-
                                           agement Association's (AWMA) annual meeting in
                                           San Antonio on June 16. About one third of the stu-
                                           dents were from state and local agencies, while the
                                           remainder were primarily from industry, academia and
                                           consulting firms. Foreign attendees  included indi-
                                           viduals from Mexico, South Africa and Taiwan.  Most
                                           of the course time was spent working on the FIRE
                                           database onaprototype of theAir CHIEFCD-ROM,
                                           version 4.0.  This opportunity allowed students to
                                           have hands-on experience with  these systems and
                                           other emission estimation tools from EFIG. A similar
                                           presentation is planned for the Emission Inventory
                                           Conference this October 10-13 at Research Triangle
                                           Park, NC. If interested in attending, either respond to
                                           the AWMA flyer when it is mailed in July or contact
                                           AWMA at (412) 232-3444.
                                             NEW INTERNATIONAL GUIDANCE ON
                                           GREENHOUSE GAS INVENTORIES ISSUED

                                              The Intergovernmental Panel On Climate Change
                                          (IPCC) has issued a three-volume final guidance on
                                          greenhouse gas inventories.  The requirement for a
                                          greenhouse gas inventory was agreed to by about 150
                                          countries at June 1992 summit in Rio de Janeiro. Vol-
                                          ume 1 consists of the reporting instructions, Volume 2
                                          is a workbook, with emission estimation methodology,
                                          and Volume 3 is the reference manual. The U. S. Green-
                                          house Gas Inventory is being prepared by EPA's Office
                                          Of Policy, Planning And Evaluation.  The approved
                                          emission estimation methodology is aimed at countries
                                          without sophisticated emission inventory programs in
                                          place, although other countries may use them.  These
                                          documents are currently available in English and are
                                          being translated into French, Spanish, and Russian.
                                          Plans include future translations into Chinese and Ara-
                                          bic. Copies of the guidance material may be obtained
                                          by contacting IPCC WGI Technical Support Unit, The
                                          Hadley Centre, Meteorological Office, London Road,
                                          BracknellRG12 2SY, United Kingdom.

                                                             ANNE POPE WILL RETURN TO EFIG
    We have been enjoying working this summer with Chris-
tina Lee, a native of Hong Kong and a rising junior in chemical
engineering at North Carolina A. & T. State University. Chris
joined us on May 22 and will stay until August 11, tracking
down emission factor gaps, testing the FIRE program, and
identifying hazardous air pollutant factor needs. She has been
able, also, to handle the usual "other duties, as assigned".
                                                           Anne Pope has been away from the Emission Factor And
                                                       Inventory Group since the OAQPS reorganization several
                                                       months ago, working on development of teacher training infor-
                                                       mation and other environmental education topics. She expects
                                                       to be returning to the Group in the next few weeks.  Welcome
                                                       back, Anne!

        The Task Force On Emission Inventories, chartered under the United Nations Economic Commission For Europe (UNECE),
met in Oslo, Norway, June 12-16. David Mobley represented the United States and the Environmental Protection Agency (EPA).
The 80 meeting attendees represented 22 countries and seyejaj international organizations.  The participants are very congenial
and are dedicated to improving emission inve|f ories,,,;;E|lglS§ \tas®|j|g.nly common language (a great benefit to Mobley!).
                                                                           of Norway and Gordon Mclnnes of the
                                                                    t^j^eveloping Emission Inventories In The
                                                                    w1!§g0he preparation, were accomplished by the
                                                                      ,%j!pr Plants and Industry
        The primary purpose of the mejiifig;
European Environment Agency, was
UNECE, which should be completed w
following Expert Panels:
                Ammonia (NH3)
                Volatile Organic Comp|Siijtids:J
                Heavy Metals and Pe||i||f nt
                Mobile Sources     ";W:f?il,  :'^''«sv?-?^ '"    /5>--''•;!?''  JK Strategic Overview
                Marine Sources      ''Ifeifl •-. ' '%ii?*8i Si3*'  >ijlj>'  ,L.' la*|¥''
David Mobley, leader of the Verification Ex^^'|^eCl^|ii^:ie^brJ?|^tBl: topic that is available for review by interested
parties.                                "''•Ilitlttl,,              siHiSIf'*"'
        The Europeans are still trying to finalizeilhiiElpKEjtis^teiatentory for member countries under the CORINAIR
program. Canada is still trying to finalize the 1990 emissit^eftnveniory for their Provinces, and EPA is still trying to integrate 1990
emission inventory data from the U. S.  Thus, the timeliness of a worldwide emission inventory data compilation is generally
unacceptable. The need for major overhaul of data management approaches was noted, and such activities are under way in
Canada, Europe, and the U.  S. The Task Force On Emission Inventories has largely met its original mandate, but its value and
necessity in the UNECE context have been recognized, and extension of the Task Force for another three years has been
        In summary, the meeting was very productive as it is worthwhile for all parties to exchange information on standardized
emission estimation approaches. The next meeting is targeted for June 1996 in the United Kingdom.
                  AP-42 UNITS
                                                                   STONE EMISSION FACTORS
        The AP-42 team has revisited the question of En-
glish vs. metric units in AP-42. As you know, the country is
committed to metrification on a somewhat uncertain sched-
ule. AP-42 currently contains dual tables that take up a very
large amount of space. The presumption of our deliberations
was that most of our clients currently still use English units,
our data systems are still in English units, but we also need to
comply with directives in an efficient way.  Therefore, in the
future, we plan to omit the metric data and to provide conver-
sion information in footnotes and/or another easily accessible
and understood format. If you have any comments on this,
please send them to us via the CHIEFBBS or e-mail.
                                                           A great deal of concern has arisen over any emission fac-
                                                       tors for the crushed stone industry beyond those for PM-10.
                                                       We are currently deliberating with various interests and inputs
                                                       on the best technical factors to use, if any, for anything larger
                                                       than PM-10. Our permits and policy folks are deliberating over
                                                       options for definition of the "regulated pollutant" for this indus-
                                                       try. We hope the results of these deliberations will be available
                                                       soon, at which time we will publish any update of the factors on
                                                       the CHIEF BBS and Fax CHIEF (with appropriate alerts and
                                                       explanations). We appreciate your patience on this, as we know
                                                       there  are many people interested in the outcome.
                                                    » >"



                                                      FIRST CLASS MAIL
                                                      POSTAGE AND FEES PAID
                                CORRECTING OUR CORRECTIONS!
                   In the Spring 1995 CHIEF Newsletter, we made a correction in the spelling of the
               Region X contact name, Rindy Ramos, but the area code was misprinted. Rindy
               Ramos's real phone number is (206) 553-6510. We apologize for the mistake.
  Emission Factor And Inventory Group
    The CHIEF Newsletter is produced quarterly by the Emission Factor And Inventory
Group, Emissions Monitoring And Analysis Division, of EPA's Office Of Air Quality
Planning And Standards. Its purpose is to enhance communication within the emission
factor and inventory community by providing new anduseful information and by allowing
for the exchange of information between and among its readers.  Comments on the
Newsletter and articles for inclusion in it are welcome and should be directed to Emission
Factor And Inventory Group (MD-14), US EPA, Research Triangle Park, NC  27711;
telephone (919) 541-5493.
    The contents o/The CHIEF Newsletter do not necessarily reflect the views and
policies of the Agency, neither does the mention of trade names or commercial products
constitute endorsement or recommendation for use.
                                      The CHIEF Newsletter
                                          Volume VI, No. 3
                                            Summer 1995