United States
                 Environmental Protection
                 Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
                 Research and Development
EPA/600/SR-93/045  May 1993
*? EPA       Project Summary

                 Identification  and
                 Characterization of Five
                 Non-traditional Source
                 Categories:  Catastrophic/
                 Accidental  Releases,  Vehicle
                 Repair Facilities,  Recycling,
                 Pesticide Applications, and
                 Agricultural Operations
                 Stanley Sleva, J.A. Pendola, John McCutcheon, Ken Jones, and S.L Kersteter
                  This report presents the results of
                 work that is part of EPA's program to
                 identify  and characterize emissions
                 sources not currently accounted for
                 by either the existing Aerometric In-
                 formation Retrieval System (AIRS) or
                 State  Implementation Plan (SIP) area
                 source methodologies and to develop
                 appropriate emissions estimation
                 methodologies and emission factors
                 for a  group of these source catego-
                 ries. Based on the results of the iden-
                 tification and characterization portions
                 of this research, five source catego-
                 ries were selected for methodology
                 and emission factor development:
                 catastrophic/accidental  releases, ve-
                 hicle repair facilities,  recycling, pesti-
                 cide  application,  and agricultural
                 operations. This report presents emis-
                 sions  estimation methodologies and
                 emission factor data for these source
                 categories.
                  The discussions of each category in-
                 clude  general background information,
                 emissions generation  activities, pollut-
                 ants emitted, sources of activity and
                 pollutant data, emissions estimation
                 methodologies, issues to be consid-
                 ered, and recommendations. The .infor-
                 mation used in these discussions was
                 derived from various sources includ-
                 ing available literature, industrial and
                 trade association publications and con-
tracts, experts on the category and ac-
tivity, and knowledgeable federal and
state personnel.
   This Project Summary was devel-
oped by EPA's Air and Energy Engi-
neering Research Laboratory, Research
Triangle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).

Introduction
  Area source emissions of particulate
matter (PM or TSP), sulfur dioxide (SO ),
oxides of nitrogen (NO), reactive volatile
organic compounds  (VOCs) and carbon
monoxide (CO) are estimated annually by
the National Air Data Branch (NADB) of
the U.S. Environmental Protection Agency
(EPA). Area sources are typically aggre-
gations of individual  sources that are too
small to be defined as point sources in a
specific geographic  area. Area sources
usually include all mobile sources and any
stationary sources that are too small, diffi-
cult, or numerous to be inventoried as
point  sources. The  National Emissions
Data System (NEDS) is the data manage-
ment and processing system that has his-
torically been used to  maintain these
annual emissions data. The statutory re-
quirement for  annual inventories defines
an area source as an anthropogenic mo-
                                                            Printed on Recycled Paper

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bile or stationary source that emits less
than 100 tons* per year (TRY) of TSP,
SO, NO or VOCs, or 1,000 TPY of CO.
  "The original NEDS  area  source  meth-
odology and algorithms were developed
in 1973 and 1974 using 1960 census data
(e.g., population, housing, manufacturing).
The NEDS methodology,  relatively  un-
changed over the past 17 years,  forms
the basis for the AIRS' Area and Mobile
Source Subsystem (AMS) methods. The
Joint Emissions Inventory Oversight Group
(JEIOG) is currently updating and revising
estimation and allocation methods, using
more recent data.
  While emissions  sources included in
current inventory methodologies do cover
a large portion of anthropogenic emissions,
many small source categories are not in-
cluded in the inventory. Identification, char-
acterization, and  inclusion  of  these
categories  and their emissions in the in-
ventory will result in a more thorough  and
complete emissions inventory.
  This report more fully characterizes five
source categories not  currently accounted
for in the NEDS area source and AIRS/
AMS methodologies:  Catastrophic/Acci-
dental Releases, Vehicle Repair Facilities,
Recycling Processes, Farming Operations,
and Crop Dusting/Pesticide Application. To
the extent that data and information are
available, the following topics are included
in the categorization:
       Definition and description of the cat-
       egory and activity
   •   Process identification and definition
   •   Pollutants emitted from each identi-
       fied process
       Estimate of the pollutant levels
       Source activity  data availability
       Level of detail required by user
       Emission factors available/required
       for each identified process
       Regional, seasonal, or other tem-
       poral characteristics
       Potential methodology
       Additional data requirements  criti-
       cal to methodology development
 Catastrophic/Accidental  Re-
 leases—Rail Car.TankTruck, and
 Industrial Accidents
   Catastrophic releases, which  often in-
 volve the  release of large quantities  of
 substances  over a very short period  of
 time,  potentially represent a significant
 portion of an area's total emissions. How-
 ever, these emissions are not represented
 in  the current area source emissions in-
 ventory methodology.
    For this discussion, catastrophic/acci-
 dental releases refer to the unintentional
and unexpected, sudden release of pollut-
ants to the atmosphere  from rail cars,
tank trucks, and industrial facilities. Natu-
rally occurring releases like the Mount St.
Helens volcanic eruption in  1980 are not
covered in this definition. The accident or
catastrophe may be caused by equipment
failure, roadway conditions,  human error,
or by natural conditions  (i.e., hurricane,
lightning, earthquake, or flash flood). These
two types of releases differ in their sever-
ity. Because accidental releases are con-
sidered not as severe as  catastrophic
releases, minor accidental releases often
go unreported,  whereas catastrophic re-
leases are reported.  Examples  of  acci-
dental releases are the overloading of an
underground  storage  tank and chemical
spill resulting from a highway truck  acci-
dent. A catastrophic release would be the
Chernobyl disaster.
   Catastrophic  releases from rail car, tank
truck, and industrial accidents are usually
chemical spills, with  or without combus-
tion.  The  types and  quantities of emis-
sions  depend  on factors  such  as the
material released, remediation efforts, and
weather conditions.
   The nature  of  catastrophic releases
makes precisely describing the released
materials  difficult.  A  material may be in
one form for storage or transportation but
may form a different substance when re-
leased. A compilation of common hazard-
ous materials from the U.S.  Department
of Transportation's (DOT's)  National Re-
sponse Center (NRC) that could be sub-
ject to accidental  release is also included
in EPA's  List of Hazardous Substances,
Section 302.4(a)  of  the  Comprehensive
Environmental  Response, Compensation,
and Liability Act (CERCLA). VOC species
emitted are  dependent on  the material
released.  VOC, NO, and CO emissions
are possible if combustion  takes place.
Air toxics may also be emitted.
   Levels  of  pollutants vary  widely from
year to year and from area to area. Due
to the nature of catastrophic/accidental re-
 leases, it is very difficult to estimate an-
 nual  emissions for any  particular
 hazardous material.  Using national haz-
 ardous material databases, information on
various spills  can be collected. For in-
 stance, using information from the Emer-
 gency Response Notification System
 (ERNS)—a database run by EPA and sup-
 ported by the U.S. Coast Guard (USCG)—
 estimates  for  the reported  quantities of
 released hazardous substances were ob-
 tained. In  1989, an  estimated 219.8 mil-
 lion  Ib*  of hazardous substances  were
   1 TPY • 0.907 metric ton (tonne)
   1 Ib = 0.454 kg
catastrophically/accidentally released in the
U.S. and  its  territories.  This  number  is
probably low  because it covers only re-
ported occurrences.
  40  CFR Part  302.6 requires that re-
leases of hazardous chemicals be reported
to the NRC. The NRC maintains a data-
base  on oil spills, hazardous  materials,
and other releases. Data reported for each
accident include, but are not restricted to,
      Date of release
      Material released
      Media affected (water, air, etc.)
      Mode (train, ship, truck, etc.)
      Location
      Quantity released
  Another source of information on cata-
strophic emissions is  ERNS. ERNS is a
national computer database and retrieval
system  that is run by the EPA and  sup-
ported by the USCG.  ERNS stores infor-
mation on releases of oil and  hazardous
substances, and provides a direct source
of easily accessible data that can be  used
to analyze spills and to support emer-
gency planning efforts by federal, state,
and local governments. The database con-
tains the following types of information:
      Material released
      Amount released
      Source of release
      Incident location
      Response actions taken
      Environmental  medium  into which
      the release occurred
  Information from ERNS is made avail-
able to  the public in periodic reports pub-
lished by EPA's  Emergency  Response
Division. These  reports  can be obtained
by calling the Resource Conservation and
Recovery Act (RCRA)/Superfund  Hotline
at  1-800-424-9346 (in  the Washington,
D.C. metropolitan area, call   1-202-382-
3000).
  A future source of information on acci-
dental releases will be the Toxic  Chemi-
cal Release Inventory (TRI). TRI contains
files on the annual estimated releases of
toxic chemicals to the environment from
 point sources complying with Title  III of
the Superfund Amendments and Reau-
thorization Act (SARA) of 1986. EPA col-
 lects the information,  and it becomes
 accessible through the National  Library
 of  Medicine's (NLM) Toxicology  Data
 Network  (TOXNET).  Data submitted to
 EPA include names and  addresses of
 facilities  that manufacture, process, or
 otherwise use these chemicals,  as well
 as amounts released to the environment
 or transferred to waste sites.

 Vehicle Repair Facilities
   Vehicle repair facilities are  defined as
 locations that service or repair light-duty

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 vehicles with predominantly gasoline en-
 gines. This category includes the general
 service station or garage, as well as facili-
 ties offering more specialized services
 (e.g., oil change, tune-up, muffler/exhaust
 repair, radiator repair). This category does
 not include exterior-related services such
 as car washing/detailing shops and paint
 and body repair shops. Many repair activi-
 ties that generate emissions are also per-
 formed by individual vehicle owners. These
 do-it-yourselfers  (DIYers) could account
 for a large percentage of the  emissions
 related to this category. Due to the broad
 scope of this category, several  subcat-
 egories were identified. The following sub-
 categories represent the fluids or classes
 of fluids identified  as sources of emis-
 sions:
   Maintenance
         Antifreeze/engine coolants
     •   Brake fluids
         Crankcase oils
         Lubricants & silicones
     •   Steering fluids
     •   Transmission fluids
         Windshield washer fluids
   Cleaning
         Brake cleaners
         Carburetor and choke cleaners
         Engine/parts cleaners/degreasers
   Specialty
         Belt dressings
         Engine  starting fluids
     •   Tire repair products
   .  •   Windshield deicers
   Additives
         Crankcase
         Fuel system
         Radiator
         Transmission
   Automotive repair products are used by
 professional mechanics and vehicle own-
 ers. VOC emissions from  automotive flu-
 ids are associated with  draining, refilling,
 overfilling, or replacing fluids and from run-
 ning and standing losses. Vehicle repair
 facilities  generate emissions through  the
 use of products containing solvents and
 aerosol propellants. Propellants are used
to propel aerosol products from contain-
 ers, solubilize active ingredients, and serve
 as part of the diluting system. Solvents
 solubilize the product ingredients  and af-
fect the  evaporation rate of the product.
 Many of these products are composed of
 VOCs. In addition, some of the compounds
 in automotive fluids are considered haz-
ardous, composed of toxic and ignitable
chemicals.
  Some categories and  product types
were found to be more fully defined than
others, particularly with regard to the speci-
ficity of the terminology for various dis-
 crete product types and the variability of
 formulations for a specific type of product.
 For example; the basic functional fluids
 used in  vehicles (antifreeze, brake fluid,
 transmission fluid, etc.) tend to have the
 same  basic formulation and principal  in-
 gredients. However, the term "carburetor
 cleaner" can apply to products designed
 to be sprayed into the carburetor as well
 as buckets  of solvent used to soak par-
 tially disassembled carburetors. There are
 also numerous other examples of multi-
 use products, such as dressings, and other
 product  categories  such  as lubricants,
 where descriptions and designations may
 overlap.  With the available information on
 product types and formulations, it can be
 difficult to distinguish between formula-
 tions for distinct product types (i.e., prod-
 ucts with different intended applications)
 and different formulations for products in-
 tended for the same basic use. In some
 cases, varying formulations may be due
 to differences in product form (e.g., aero-
 sol, liquid, or solid),  while some products
 in the same category may use different
 ingredients  for the  same  function (e.g.,
 different solvents) or even operate on dif-
 ferent  basic principles (solvent versus al-
 kaline  cleaning).
   Almost without exception, the products
 discussed in the report are designed and
 labeled for use in general automotive ap-
 plications, which include cars, trucks, and
 motorcycles. Specific products for trucks
 or motorcycles are mentioned where they
 have been identified.
   The EPA report, "Compilation of Air Pol-
 lutant Emission Factors," AP-42, contains
 national  evaporative emissions and per
 capita  emission factors  for  commercial/
 consumer solvent use. The only automo-
 tive product categorized, however, is wind-
 shield  washing. The windshield washing
 per capita emission factor listed is 0.63 Ib/
 yr. Use  of this factor and assuming an
 annual growth  rate  of 1.8%  results  in a
 VOC emissions national total of 81,900
 TPY. National VOC estimates for solvents
 used in  automotive repair  in  1986 are
 37,143 TPY. In a study of New York State
 emissions, the total emissions of VOCs
 for 49  consumer product categories are
 estimated as 26,979 TPY. Of  this total,
 2,766 TPY are attributed to seven auto-
 motive categories: auto antifreeze,  carbu-
 retor and choke cleaners, brake cleaners,
 engine degreasers,  engine  starting fluids,
 lubricants and  silicones, and windshield
deicers. In addition to these data, the Cali-
fornia Air Resources Board (GARB) has
an extensive program underway to reduce
VOC emission  from consumer products.
This effort includes data on average an-
 nual day VOC emissions from aerosol con-
 sumer products in California. For the cat-
 egory automotive and industrial consumer
 products, GARB estimates a total of 3.96
 VOC tons per  day (TPD) of propellant
 emissions and 27.37 TPD of solvent emis-
 sions for a combined total of 31.33 TPD.

 Recycling
   Recycling may be defined as the recla-
 mation  of materials from waste.  For this
 report, the definition includes all activities
 or processes  related to the recycling ef-
 fort, beginning with the removal of  mate-
 rial from the waste stream and extending
 to where recycled  material is essentially
 identical to products derived from  virgin
 materials or may be acceptable as a sub-
 stitute for virgin  materials. This distinction
 is made to concentrate on the air  emis-
 sions which are attributable to recycling
 processes to  the  identified point.  In re-
 porting emissions, however, care is needed
 to ensure that emissions associated with
 a recycling  process  are  not  double
 counted. For  example vehicle emissions
 resulting from the collection of recyclable
 materials should be reported as part of a
 mobile source inventory and not as part of
 a recycling emissions inventory. Air emis-
 sions data are  currently available from
 several  information sources, such as AP-
 42 and EPA's AIRS, for a number of manu-
 facturing  processes which  incorporate
 recycled materials. Presented in the re-
 port are findings from research on the air
 emissions generated during recycling pro-
 cesses involving  five materials: paper, plas-
 tic, glass, metals  from Municipal  Solid
 Waste (MSW), and solvents. Recycling of
 the first four  materials  involves  one  or
 more energy-intensive  steps. Emissions
 resulting from associated energy  produc-
 tion, however, are not addressed as part
 of this section.  This section focuses on
 emissions from actual recycling processes.
  The  fifth category of  materials  re-
 searched  for air emissions resulting from
 recycling was solvents. Unlike the  other
 four recyclable material categories in this
 study which originate in homes or  com-
 mercial establishments, spent solvents are
 generated  primarily by industry.  As the
 point of origination and the recycling path
 of spent solvents are significantly different
 from the other materials,  the findings on
 this subject are presented separately.
  A limited amount of statistical informa-
tion is provided  to describe the extent  of
 recycling activities.  Sections of the  recy-
cling  industry  are  experiencing  rapid
change. As evidence of this change, perti-
 nent historical data are  provided along
with projections. The flow of recyclable

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material is traced from the post-consumer
waste stream through  the production of
materials suitable for secondary markets.
Descriptions of the various collection and
sorting methods are provided, followed by
a detailed description of material-specific
processing activities. Information  which
considers potential  to  emit air contami-
nants is presented  for  each of the four
materials in the study.
  Historically, recycling  has been  prac-
ticed primarily by the manufacturing sec-
tor to reduce waste stream volumes, the
resulting disposal costs,  and also as a
means of cost recovery by selling  scrap
materials.  Recycling of  post-consumer
wastes was primarily limited to paper and
rags until the 1970s. The environmental
movement was partially  responsible for
educating the general  population on the
potential benefits of recycling, but mar-
kets for recycled materials remained lim-
ited. One of the driving forces behind an
increased interest in recycling is the dwin-
dling  number of available landfills in the
more densely populated areas of the U.S.
The MSW Landfill Survey conducted by
EPA projects that the number of landfills
is expected  to decrease from  approxi-
mately  5500  in 1988  to about 1000  in
2013.
  Three disposal methods are used for
MSW: landfilling, incineration, and recy-
cling. Incineration and  recycling  are be-
coming increasingly popular. In 1984,85%
of MSW was disposed  of in landfills, 5%
was incinerated, and 10% was recycled.
Statistics from 1988 show the incineration
and recycling proportions to have grown
to  14.2 and 13.1%,  respectively, with
72.7% disposed of in landfills.
   In 1986,17 million tons of material was
recycled, a 13% increase over the 1984
level. This amount is primarily due to vol-
untary efforts. However, most states have
adopted recycling initiatives with recycling
targets of  15% or higher. EPA has set a
national recycling goal of 25% of the MSW
by 1995. It is estimated that 63% of MSW
generated in 1988 was  recyclable. Fur-
ther, disposal of these materials accounted
 for 68% of landfill volume.
   Several criteria pollutants would be re-
 leased by vehicles involved in the collec-
tion  and  transportation of recyclable
 materials. CO, NO,, PM, and VOCs are
 emitted by vehicles. However, such emis-
 sions should  not be counted as part of an
 agency's  recycling  emissions inventory.
 Their proper place is the mobile source
 Inventory.
   When assessing  emissions quantities,
 factors to be considered would  include
 the type  of  recycling  program  and the
extent  of  public participation.  Many
curbside recycling programs attempt to
minimize additional  vehicle  (and man-
power)  requirements by collecting recy-
clable  materials  concurrently  with
non-recyclables. Given  that many munici-
palities collect refuse weekly, vehicle miles
travelled (VMT)  by refuse  collection ve-
hicles should represent a negligible por-
tion of total VMT in most areas.
  Programs that require a second pickup
would result in additional VMT during col-
lection.  Some  municipalities  have gone
from weekly  pickup of MSW to  biweekly
alternating  pickups of both  MSW and re-
cyclable materials. This approach was de-
signed  to minimize additional VMT. For
programs  resulting  in increased VMT,
emissions may be estimated by obtaining
the VMT attributable to  recycling and other
vehicle  information.
  Regardless of the type of recycling pro-
gram, the result of waste segregation pro-
duces one or more  reclaimed  materials,
and remaining  wastes which require dis-
posal by landfilling or  incineration. Incin-
eration  achieves significant waste volume
reductions,  lending to  increased landfill
lifetimes. As of 1988, nearly 160 MWC
facilities were on-line,  accounting for ap-
proximately 320 incinerators. Air emissions
resulting from waste combustion must be
addressed along with  potential problems
associated with the disposal of incinerator
ash. Over  95% of the  municipal combus-
tors brought on-line since 1980 have heat
recovery boilers. These facilities represent
78% of the  total incinerator capacity of
68,000 TPD. Although energy is "recov-
ered" at some facilities, incineration is not
considered to be a recycling process for
the purposes of this report.
   Automated systems  are often employed
in separating waste types in either of these
facility  types. A  number of different pro-
cesses may be employed to remove ma-
terials  from the waste stream. Upon
arriving at a processing facility,  collection
vehicles usually dump their contents on a
tipping floor. Equipment, such as a front-
end loader, is used to  transfer the materi-
als  to  a  conveyor  system. The waste
 moves between one or more stations within
the facility where specific components are
targeted for removal from the total stream.
The waste is treated by a  number of pro-
cesses to achieve material-specific segre-
 gation. Some  recyclables may also  be
 subjected to compaction and/or baling prior
 to shipping.
   A number of facilities may use manual
 extraction  of specific  materials from the
 waste  in place of any or all  of the afore-
mentioned mechanical  means.  This is
more common in smaller scale facilities.
  The  methods of separation  used  by a
given facility depend on  a number of fac-
tors, including waste stream composition,
throughput rates,  workers' wages, health
and  safety considerations, alternate dis-
posal  methods, and secondary  market
material specifications and prices.
  After separation and consolidation, pa-
per,  plastic, glass, and metals are all sub-
ject  to a  unique  series  of  additional
processes  in preparation  for sale in the
secondary market. The  path followed by
each material is presented separately.

Pesticide Application
  Under the Federal Insecticide, Fungi-
cide and Rodenticide Act (FIFRA), a pes-
ticide (or economic poison) includes any
substance or mixture of  substances in-
tended for preventing, destroying, repel-
ling, or  mitigating  any pest, and  any
substance or mixture of  substances in-
tended for use as a plant regulator, defoli-
ant, or desiccant. The general  category of
pesticide  can be further  defined by  the
following terms which identify the target of
the pesticide:
       Acaricide (miticide) - used to con-
       trol  plant-feeding mites  (acarids)
       Algicide - used to control algae
       Aphicide - used  to  control aphids
       (plant lice)
       Avicide - used to control pest birds
       Bactericide - used to control bacte-
       ria
       Biocide - when absorbed by eating,
       drinking, breathing, or other means
       in  relatively  small  quantities, may
       cause illness or death,  or even re-
       tardation of growth or shortening of
       life
       Fungicide - used to protect against
       fungi
       Gameticlde - used to prevent polli-
       nation
       Herbicide - used to control weeds
       Insecticide - used to control insects
       Larvicide - used to kill insect larvae
       Molluscicide - used to control slugs
       and snails (mollusks)
       Nematicide - used to control nema-
       todes
       Ovicide - used to kill  eggs  of in-
       sects and mites
       Piscicide - used to control fish
       Predacide - used to control  verte-
       brates
       Rodenticide - used  to control  ro-
       dents (rats,  mice, etc.)  and related
       animals (such as rabbits)
       Slimicide  -  used to control  slime
       and molds

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   Of the total pesticides currently used in
 the U.S.,  approximately  60% are herbi-
 cides, 25 to 30% are insecticides and 10
 to 15% are fungicides.
   Several additional terms  are used  to
 describe the actions or purposes, rather
 than the target, of certain pesticides.
       Defoliant - a preparation  intended
       for causing leaves to drop from crop
       plants such as cotton, soybeans,
       or tomatoes, usually  to  facilitate
       harvest
       Fumigant - a substance or mixture
       of substances which produce gas,
       vapor, fume, or smoke intended to
       destroy insects, bacteria, or rodents
       Plant growth regulator - a prepara-
       tion which, in minute  amounts, al-
       ters the behavior of ornamental  or
       crop plants or the produce thereof
       through physiological (hormonal)
       rather than physical action
       Repellant - a material used prima-
       rily for the control of insects, birds,
       and other vertebrates
   Pesticides fall into three basic chemical
 categories: synthetics, non-synthetics (pe-
 troleum products), and inorganics. Formu-
 lations are commonly made by combining
 synthetic materials with various petroleum
 products. The  synthetic  pest-killing com-
 pounds in  such formulations are labeled
 active ingredients; the petroleum product
 solvents acting as carriers or diluents  for
 the active ingredients are labeled inert.
 Pesticides  are  regulated primarily on the
 basis of active ingredients. (The terms
 active and inert in this application refer to
 toxicological action in pesticides and are
 not to be confused with the common use
 of these terms to indicate photochemical
 activity.)
  Carriers  are  inert materials added to a
 technical (or economic) poison to facilitate
 later dilution to field strength in simple
 blending equipment. (A technical poison
 or technical material is defined  as. the
 pesticide chemical  in pure form,  usually
 95 to 100% active ingredient, as it is manu-
factured by a chemical  company prior to
 being formulated into wettable  powders,
dusts, emulsifiable concentrates,  granules,
 etc.) Certain kaolin clays,  attapulgites,
diatomites, and several highly absorbent
synthetic pigments are  used as carriers.
 Diluents are material liquids or solids serv-
ing to dilute the technical material to field
strength for adequate plant coverage,
maximum  effectiveness,  and economy.
They may be used directly with  technical
materials to dilute to field strength sprays
or dusts, but usually  are blended  with
wettable powders and  dust concentrates
previously  prepared with  carriers.  The
 most widely used solid diluents  are ka-
 olin clays, pyrophyllites,  and  talcs, al-
 though attapulgites and diatomites, local
 clays, limestone products, and other min-
 erals are also  used. Although solid carri-
 ers and diluents are generally considered
 to  be  inert, certain attapulgites, kaolin
 clays,  and diatomites aid in increasing
 toxic effectiveness, probably due to physi-
 cal properties  which  induce starvation,
 desiccation, and abrasion. Most formula-
 tions of dusts  and sprays contain from
 80 to 99% carrier-diluent.
   Adjuvants are materials which are added
 to a pesticide mixture  in the spray tank to
 improve mixing and application or enhance
 pesticide  performance. An adjuvant  cus-
 tomizes the formulation to meet  specific
 needs or to compensate for  local condi-
 tions. By  using the proper adjuvant, it is
 often possible to use certain chemical pes-
 ticides  in  a tank  mixture  that otherwise
 would present  compatibility problems. (A
 tank  mix   is a  mixture  of two or  more
 pesticides in the spray tank at the time of
 application. Non-compatibility of the ingre-
 dients can be  a problem.) The term in-
 cludes  such   materials  as  buffers,
 defoaming agents, spreaders, stickers, and
 surfactants. Often, a single adjuvant will
 accomplish more than one adjuvant func-
 tion, such  as a spreader-sticker or
 spreader-sticker-drift retardant.
  The "process breakdown" depends on
 several factors including the user, the pes-
 ticide formulation,  the  type of equipment,
 the crop or area to be treated, the appli-
 cation,  and treatment. These factors are
 often closely interrelated and not easily
 separated from one another. For example,
 while the formulation of the pesticide helps
 to determine the type of equipment to be
 used, the  type of equipment available de-
 termines the type  of formulation that can
 be  used.  The  specific pest  to be  con-
 trolled determines the type of pesticides
 used. Particular pesticides may  not  be
 available in all formulations.
  Pesticide application  may  be  broken
 down into  several  user  categories:  con-
 sumer,  agricultural,  commercial, munici-
 pal, and industrial. Consumer application
 refers to individual home and garden pes-
 ticide use. These  products are generally
 applied  as  sprays or  baits and include
 disinfectants, fungicides, insecticides, mol-
 luscicides,  rodenticides,  herbicides, and
 repellents.  Agricultural pesticide applica-
tion refers  to farm chemical usage, other
than fertilizers,  for soil and site prepara-
tion, pest control, and harvesting aids. Ag-
 ricultural pesticides can  be applied in a
variety of formulations (sprays, dusts, pel-
  lets, fogs, etc.) from the ground or from
  the air (aerial application).
    Commercial  pesticide application  in-
  cludes professional treatment  of homes,
  buildings, and lawns for fleas,  cock-
  roaches, termites, nematodes,  crabgrass,
  etc.  Municipal pesticide application refers
  to governmental use of pesticides for mos-
  quito control, roadsides, aquatic pests, etc.,
  and  includes both ground and aerial appli-
  cations. Industrial application refers to use
  for power line and  gas line right-of-ways,
.  etc.
    Approximately 68 to 75% of pesticides
  used in the U.S. are applied to agricultural
  lands, both cropland and pasture. Between
  8  and 17%  of pesticides are used pri-
  vately  for home and garden pests, and
  the  remainder,  8  to 24%,  are used  for
  industrial, commercial, and governmental
  purposes.

  Agricultural Operations
    Agricultural (farming) operations include
  plowing, disking, fertilizing, applying pesti-
  cides, preparing seed beds, planting, cul-
  tivating,  and  harvesting.  All  these
  operations can  be  generically classified
  as soil preparation, soil maintenance, and
  crop harvesting. For the  purposes of this
  discussion,  agricultural operations have
  been divided into  two major categories:
  tilling and harvesting. Tilling includes plow-
  ing,  disking,  fertilizing, pesticide applica-
  tion, seed bed preparation,  planting, and
  cultivating, (i.e., soil/site  preparation and
  soil maintenance).  (Cultivation  is defined
  as shallow tillage operations performed to
  create  soil conditions conducive  to  im-
  proved aeration, infiltration, and water con-
  servation, or to control weeds.)
   Tilling and harvesting can result in emis-
 sions of  PM, as well  as VOCs and air
 toxics from the disturbed  soil and organic
 matter (weeds, crop residue). Dust emis-
 sions from tilling are greatest during peri-
 ods of dry soil and during final seedbed
 preparation, and depend  on surface soil
 texture, surface soil moisture content, and
 other conditions of a particular field being
 tilled. In addition, PM emissions are also
 generated by wind  erosion of bare or par-
 tially vegetated soil.
   Tilling and  harvesting activities can be
 broken down by crop  (e.g., sugar cane,
 cotton, wheat), soil type  (e.g., clay, silt,
 loam), site characteristics, and activity type
 (e.g., manual versus machine harvesting).
   All tilling and harvesting operations can
 result in PM, VOC,  and  air toxics emis-
 sions. The type of tilling operation affects
 the rate of emissions. In addition, the crop
 being harvested and the crop residue that
 is tilled under after  harvest can also add

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organic particles to  the  dust emissions.
PM emissions also result from wind ero-
sion of the tilled soil.
  The National Acid  Precipitation Assess-
ment  Program (NAPAP) developed esti-
mates of  wind erosion from natural and
agricultural lands. National TSP emissions
from  this  category  for 1985 were esti-
mated at 4,711,540 tons. PM-10  emis-
sions  were estimated to be 1,130,769 tons.
No estimates  of VOC or air toxics  emis-
sions from tilling  and harvesting opera-
tions  are available.
  Most emissions from agricultural opera-
tions  occur in  rural areas. Seasonally, till-
ing emissions will occur  primarily  in the
spring,  especially around final seedbed
preparation time. Harvesting  emissions
occur primarily at the end of the growing
season, in the  fall. Wind erosion  emis-
sions occur primarily when soils are dry
and not protected by a vegetative  cover,
primarily during the winter and spring.
                                                                                         •U.S. Government Printing Office: 1993— 750-071/60233

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S. Sleva, J. Pendola, J. McCutcheon, and K. Jones are with TRC Environmental
  Corp., Chapel Hill, NC 27514; and S.  Kersteter is with Science Applications
  International Corp., Durham, NC 27707.
E. Sue Klmbrough Is the EPA Project Officer (see below).
The complete report, entitled "Identification and Characterization of Five Non-
  traditional Source Categories: Catastrophic/Accidental Releases, Vehicle Repair
  Facilities, Recycling, Pesticide Applications, and Agricultural Operations," (Order
  No. PB93-166973; Cost: $36.50), will be available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Air and Energy Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Research Triangle Park, NC27711
 United States
 Environmental Protection Agency
 Center for Environmental Research Information
 Cincinnati, OH 45268

 Official Business
 Penalty for Private Use
 $300
      BULK RATE
POSTAGE & FEES PAID
         EPA
   PERMIT No. G-35
 EPA/600/SR-93/045

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