JULY 1975
  Office of Air and Waste Management
Office of Air Quality Planning and Standards
  Control Programs Development Division
  Research Triangle Park, North Carolina

U. S. Environmental Protection Agency
Office of Air and Waste Manaqement
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina
July 1975

Introduction and Purpose
This paper has been prepared to define the differences between,
and discuss pertinent facts concerning two separate, but in some cases,
strikingly similar air pollution problems, i.e., fugitive emissions
and fugitive dust emissions.
Fugitive emissions include both gaseous
and particulate emissions that result from industrial related operations
and which escape to the atmosphere through windows, doors, vents, etc.,
but not through a primary exhaust system, such as a stack, flue or
control system.
Fugitive emissions may result from metallurgical furnace
operations, materials handling, transfer and storage operations, and
other industrial processes where emissions escape to the atmosphere.
Fugi:tive-dust emissions, on the other hand, are generally related to
natural or man-associated dusts (particulate only) that become airborne
due~ to tn.~ force.s of wind, man J s activity, or both.
Fugiti ve dus t
emfssi.ons may include windblown particulate matter from unpaved dirt
roads:, tilled farm lands, exposed surface areas at construction sites,
etc.. Natural dusts: that De-come airDorne during dust storms are also
fncl uded as fugitive dusts.
The. afiove terms are deHoed as used in the context of th is report.
Tlle- reader is: advised, however, that there are no universa,lly accepted
definitions to characterize and differentiate between the two separate
"fugitive" emissi.on categories.
In fact, some use the terms interchange-
ably, and others include all fugitive sources in a single definition.
It should be noted that the EPA has recently identified a number
of Air Quality Control Regions (AQCR's) that probably may not attain

national -primary particulate matter standards due to fugitive dust
It has been found that windblown dusts from tilled farm
lands, unpaved roads, and construction sites, as well as windblown
natural particulate emissions from arid lands (desert) during dust
storms and other meteorological conditions cause ambient concentrations
above national particulate matter standards, particularly in the Western
and Southwestern States.
Fugitive emissions from industrial sources
may also contribute to non-attainment of national standards in some
industrial areas.
At this time, however, fugitive industrial emissions .--
have not been fully evaluated as a general cause of elevated levels of
pollutants and especially of non-attainment of national ambient air
quality standards.
Fugitive Emissions (Industrial)
Fugitive emissions are generated during various industrial,
manufacturing and/or materials crushing, grinding, transfer or storage
Fugitive emissions generally escape to the atmosphere at
various points, such as through windows, doors, roof ventilators, etc.,
but not through a primary exhaust system, such as a stack, flue, or
. ,
a control device.
In other cases, fugitive emissions are more directly
emitted to t~e atmosphere from those industrial processes that operate
out-of-doors-, suc~ as coke ovens and .:ock-crushing operations at quarries.
Fugftfve emissi.ons also result from poor maintenance of process equipment
and from environmentally careless process operations.
For example, fugitive
emi.ssions can result in leakage from oven doors at coke ovens because
s-uchdoors cannot be properly sealed due to excessive warpage.
some operators may begin process operations that will result in fugitive
~missions without the proper placement of available moveable hoods and
vents over the process area, because the time required to properly

align such equipment may cause production schedules to lag.
Emissions which escape from the processes are termed IIfugitiveli
because of the difficulties associated with their capture, which in
many cases require innovative and unique equipment design.
(,(V.skJ J~
captured, fugitive emissions can be ducted to available emission
c.ontrol systems, such as baQholJC:;pc; for particulates ;Inn c:;crubbers for
gaseous pollutants, where they can be effectively collected.. Because
fugitive emissions are relatively dilute
(when compared to emissions
ducted to the primary stack), more energy is generally required to
process the larger volume of air that results from an effective capture
In some cases, air from entire buildings which enclose metal-
lurgical furnaces 15- exhausted to a particulate control device to
prevent such materials from becoming airborne.
Fugitive emissions may include any pollutant that is emitted from
the. associ.ated process.
For example, particulates are primarily emitted
from materials handling operations; particulate matter and carbon monoxide
emissions may escape from blast furnaces, while fugitive sulfur dioxide
and particulate emissions may be emitted from various process operations
at non-ferrous smelters.
Fugitive emissions often have a greater effect
on air quality in the immediate vicinity of a source than do stack
Stack emissions are released above ground level, often
with a significant upward velocity and buoyancy that aids dispersion
and dilution, thereby decreasing the impact of pollution on nearby
Fuqitive emissions, by their very nature, occur at
or near ground level and rpm;l;n thprp, wher-e the j~e
workinq and living in the area is greatest. For example, the fugi-
tive particulate emissions from two non-ferrous smelters, which are
comprised of very toxic components such as lead and arsenic, have been

suspected of causing .thenoted concentration build-ups of these elements
in the soils surrounding the smelters.
Because fugitive emissions may be more "dilute" than stack emissions
(i .e., their mass concentration is not as great as stack emissions)
does not mean.- they. have, an ins i gni fi cant impact on. ambi ent. ai r qua'l-ity.
While measurements of process and non-process "fugitive emissions have
proven arduous, a few suchestimate-s.. have .been.. made thatindi cate- that
fugitive emissions may comprise a large portion of nationwide emissions.
For example, the Agency has estimated that total fugitive emissions of
particulate from electric arc furnace charging can be from 5 to 50 times
total emission during the normal operating period of the furnace when
f.itted with emission controls.
Further, a recent technical paper reported
that maximum ambient 24-hour particulate measurements observed around
three fugitive emission sources in the Pittsburgh area (i.e., a wood
oroducts process, a new steel mill, and an old steel mill) were 655 ug/m3,
447 ug/m3, and 421 ug/m3 respectively. Each of these concentrations is
well above the .24-hour primary (health) standard for parti cul ate matter
(i .e., 260 ug/m3) and is also above other observed concentrations at
background sampling sites in the area of the sources, but which were not
directly impacted by the fugitive emissions from such sources.
In addition to their impact on ambient air quality, fuqitive emissions
must in some cases be controlled to provide for effective requlatory
control of total emissions from some sources.
In some cases, source
operators could circumvent the' intent of a regulation designed to minimize
the primary (stack) emissions from the source by allowing more' than the
normal amount of emissions to escape as fugitive emissions~
In other words,

without a total regulatory approach to minimize both primary..and fugitive
emissions, a loophole exists in the regulatory scheme that may allow unlimi-
ted fugitive emissions to be emitted.
Regulatory Approaches to Control of Fugitive Emission Sources.
Genera'lly.,it is d.ifficult to quantify emissions from.fug.itive
emi ssi ons . sources.. .. Becausefugi ti ve emissions are not rel eased at a
common point,'stlch .as'.astack., .they.cannot..be.eas.ily. mea$ured to provide
control officials with estimates of the relative magnitude of emissions
from such sources.
Because of this difficulty, the potential improvement
in air quality that may result from control of such sources cannot be
estimated. This deficiency has perhaps resulted in a lack of attention
given to fugitive emissions sources in the past.
For example, under the air resources management concept of air pollu-
tion control, which is the conceptual basis of the State Implementation
Planning (SIP) process for the control of existing sources, ambient air
quality goals (standards) are established, existing source emissions are
quantified and plans (regulations) adopted to reduce emissions from
such sources to levels that will achieve ambient goals.
During the develop-
ment of SIP's, States quantified emissions from all sources using the
best available information to determine such emissions.
Primarily due
to the magnitude of stack emissions from poorly controlled sources, (i.e.,
emissions from stacks of power plants and other industrial sources),
but also because of the lack of available emission 'estimates for fugitive
emission sources, few such sources- were included in source 'emission
. . .
Hence, the emission control regulations that were 'ultimately
adopted by the State and local air pollution control agency under the
SIP's primarily addressed control of non-fugitive emission sources.

other words, the mass emission limitations (i .e., those that limit emissions
to "no more than X pounds per hour") adopted by States are not directly
applicable to fugitive emission sources.
This is because compliance
with such regulations can only be determined by measuring the total emis-
sions from the process, generally through a stack.
As previously indicated,
this is extremely difficult for process sources with fugitive emissions.
In cases\ where fugitive emissions can I)e measured it is generally
too expensive for source operators to rely upon the measurement technique
to determine source compliance.
Some States did, however, adopt general regulations to address the
fugitive emissions problem.
Four general techniques have been used to
minimize fugitive emissions, two of which are of limited value.
first involves the general, nuisa:nce'provisfonwhich most pollution control
agencies have included within their regulatory scheme. Under the nuisance
provisions, emissions from a source are not allowed if they cause any
person to suffer health or welfare effects.
Nuisance regulations can be
useful in some cases when the responsible sources can be specifically
identified, and when such source is agreeable to minimize emissions.
Generally, comprehensive source emission control programs do not result
from action taken under nuisance regulations.
The second regulato~y
approach which also has limited value requires source operations with
fugitive emissions to take "reasonable precautions to prevent fugitive
emissions from becoming airborne".
These regulations are generally
di ffi cult to enforce si nce reasonable precauti ons are not specifi ca lly
defined. The difficulties associa.ted with use of this
general require-
ment have lead to the development of the third and more successful
regulatory approach for the control of fugitive emissions, i.e., the
. ,..", .
requirement for the source operator to install, operate and maintain

specified equipment to capture and control fugitive emissions from
becoming airborne.
"Equipment standards II , as they are termed, are
enforceable and are believed to be effective for the control of
fugitive emissions.
The fourth regulatory technique used by control
agencies is the visible emissions regulation.
Such regulations generally
do not permit the presence of visible emissions greater than a speci-
fied intensity in the atmosphere for more than a few minutes of each
In some cases, sources have probably installed fugitive emissions
control systems to minimize violation of such visible emissions regula-
In general, the visible emissions approach is enforceable and
relatively easy to implement.
A regulatory approach which requires the
use of specified equipment and which uses visible emissions as an
enforcement tool is the recommended control strategy for control of
fugitive emissions (particulate) at the present time.
The difficulties States have had in developing fugitive emission
control regulations under the SIP process are shared by EPA in developing
a control program for some fugitive emission sources affected by
New Source Performance Standards (i.e., sources affected by Section 111
of the Clean Air Act).
This section of the Act requires the Agency to
set forth "a standard of performance" which is defined as a standard for
emissions of air pollutants which reflects the degree of emission limita-
tion achievable through the application of the best system (considering
cost) of emission reduction.
This has been interpreted to mean that the
Agency must develop mass emission standards, and does not have the lati-
tude of adopting regulations that solely specify the use of equipment (e.g.,
ducts, hoods, vents).
EPA believes that flexibility is needed to allow
the Agency to establish emissions standards and/or equipment requirements

depending upon the nature of emissions at the source.
For that reasons
the Agency has recommended an amendment to the Clean Air Act whichs
if adopted by the Congress s wi 11 provi de the necessary 1 ega 1 base for
EPA to manage a flexible emission control regulatory program.
An example of the current lack of regulatory flexibility for fugi-
tive emission control is illustrated in relation to the Agency's current
investigations of the grain handling industry under the NSPS regulatory
For this particular industrys dust becomes airborne at various
transfer points throughout the terminal as grain is transferred from
point of deliverys usually along conveyor beltss to hoppers for c1eanings
then to silos for storage where it is kept until shipment.
There are no
primary stack emissions at a grain terminals only the dusts that become
airborne at the various transfer points. The most reasonable regulatory
approach identified by the Agency to minimize emissions for the sources
is to require the installation of equipment such as hoods to capture the
dusts that become airborne and ducts to channel the captive emissions to
emission removal equipment. The regulatory alternative of specifying
equipment standardss howevers is currently not consistent with the present
language of Section 111 of the Act.
Despite the present limitations of the Acts it should be noted that
the Agency has implemented a fugitive emission control program for some
sources affected by NSPS and has proposed or is developing such controls
for other sources.
For examples at aluminum plants where it is possible
to measure total flouride emissions from the plants [i.e.s both fugitive
and primary (stack) emissions], an allowable emission standard for total
plant emissions has been proposed.
In order to achieve compliance with

the emission standard, the source operator must control not only
the primary emissions but also the fugitive emissions.
fu a similar
manner, the Agency has effectively regulated fugitive emissions from
cement plants, asp~alt plants and basic oxygen furnaces.
In these
cases, the Agency has established an opacity regulation in addition to
the emissions standard.
While not directly limiting fugitive emissions,
the regulatory combination of an emission standard and an opacity regu-
lation inddrectly requires these sources to capture and control some
fugitive emissions in order to comply with the opacity requirements.
each of these cases, the Agency has developed specific test techniques
to assure the enforceability of the promulgated regulations.
opacity provisions have been proposed for electric arc furnaces.
In addition, the Agency has set forth fugitive emission controls
for sources regulated under Section 112 of the Act, i.e., sources affected
by hazardous emission standards.
For example, requirements on sources
which emit hazardous pollutants, such as mercury and asbestos have been
promulgated which generally require the installation of prescribed
emission limiting equipment and/or the implementation of certain operating
and maintenance practices.
Fugitive asbestos emissions are controlled
by specifying allowable operating practices, such as the controlled venti-
lation (filtration) of air within buildings in which the material is used,
such as in textile mills.
Also, asbestos has now been prohibited from
use in building construction as a fire preventative measure, to prevent
fugitive asbestos from becoming airborne when buildings are demolished.
Fugitive mercury emissions which can be emitted in cell rooms at chlor-
alkali plants have been regulated by specifying good housekeeping measures

(e.g., daily inspection to detect leaks, etc.).
These measures
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~; ~ ~ .~:
effectively minimize emissions of mercury vapor to the atmosphere.
The Agency has under consideration the control of other fugitive
p"ll utant emi ss ions.
For example, the Agency is presently considering
fugitive emissions control of vinyl chloride emissions.
These can be
minimized by requiring the use of II leak-free" pumps, valves and seals
at numerous potential emission sources.
Control measures under consider-
ation would also require the maintenance of these devices in a leak-
free. condition and further require peri odi c moni tori ng of the premi ses
with.. 1 eak. detectors.
In addition to the development of regulations, the Agency has
various investigi:itions underway to identify and quantify' the importance
of fugitive emissions from numerous sources.
For example,studies
are in process that will document the impact of fugitive emissions for
the iron and steel industry and for copper and lead smelters. Preliminary
result!; from one such. i.nvesti:gati:on indi.cate that fugitive lead emissions
from a lead !;melter may' be. two to three ti:mes the process (stack) emissions.
As information becomes available, NSPS for such fuqitive emissions sources
will be considered.
It should be noted that existing sources in source
categories for which NSPS are promulgated shall be controlled by use of
Section lll(d) of the Act.
For example, if the Agency promulgates a'
fugitive lead emission standard for new smelters ,under NSPS, the existing
smelters with fugitive lead emissions shall be.controlled according to
the provisions of Section lll(d).
While effective action to minimize fugitive emissions has been taken
for some sources (and work is underway on others), the Agency believes

that the additional flexibility requested by the Administration is
needed to allow the Agency to specify equipment standards under the
NSPS r~gulatory proc~ss, when needed.
Fugitive Dust (Windblown dust),
For the most part, fugitive dust emissions are found in the Western
half of the nation, generally in the more arid areas such as the Southwest,
but also where farming operations and unpaved roads are prevalent.
Emi s-
sions from fugitive dust sources have been known to exist for some time,
however no quantifiable estimates of the impact of such sources on air
quality wer~ available at the time of State Implementation Plan (SIP)
Hence many States did not adopt regulations to minimize
emissions from such sources.
Because some of the SIP's were inadequate
to attain national particulate matter standards, EPA conducted an inves-
tigation of fugitive dust sources in five AQCR's in the Southwest in the
1972-1973 time period.
The results of the study (and additional studies
subsequently conducted in other areas of the West) indicated that wind-
blown dust (both natural dust and soil exposed by man, e.g., farms, roads),
and dust generated directly by man's activity (e.g., driving on unpaved
roads), created high ambient concentrations of particulate matter.
example, approximately 90% of the particulate emissions in the Phoenix
AQCR are estimated to result from fuqitive dust sources.
Measured annual
average particulate matter concentrations at some locations in the Phoenix
AQCR exceed 200 ug/m3 compared to a primary standard of 75 ug/m3.
Control of fugitive dust sources was also explored in the 1972 study.
The control strategies determined necessary to attain national standards

in each of the five AQCR's generally indicated that unconventional air ,)'
pollution control techniques were required.
Specifically the study indi':
cated that each of the following controls is probably necessary to attain
primary standards in these AQCRls.
Chemical stabilization (i.e.t the addition to the soil of a
cohesive chemical compound to bind loose particles from becoming airborne)
of a total of lt160tOOO acres of selected farm lands in the San Joaquin
ValleYt Californiat Phoenix-Tucsont Arizonat and Dona Ana CountYt New
Mexicot at an approximate cost of $50/acre/application (total yearly cost
of $50 million).' The cos-t of this control (which may also cause water
po 11 uti on and otn.er environmenta 1 problems) may equal or exceed that of
tfte cash value. of the crop and't therefore t H imposed t woul d essenti ally
result in the, cessation of farming operations in some areas.
Implementation of soil management control programst including
such measures as continuous croppingt mulch covert windbreakst strip
cropping and other soil erosion prevention techniques.
Paving of a total of 600 miles at a cost of $15.6 million of
more heavily traveled unpaved roads in generally urbanized portions of
the 5 AQCR!',S.
Speed oontrol t generally 25 mph on all unpaved roads outside
the city limits and 20 mph inside city limits for those areas with high
measured particulate matter concentrations.
If this control measure
proved to'D~ ineffective due to problems of enforceabilitXt additional
mi 1 es of roa'd. pav'i n'9' wou 1 d be needed.
Stabilization or watering of construction sitest material storage
pilest tailing piles (smelter) and animal feedlots.

Table 1 lists the specific controls and costs of implementing these
controls for each of the individual AQCR's. The costs associated with
chemical stabilization only reflect the cost of application of the material,
and not the costs associated with possible termination of active farm
lands due to the excessive costs of chemical stabilization;
The Agency has not implemented these fugi.tive dust control strategies
for tl:1e five AQCR's oecause they include controls that are considered to
be socially di:sruptive and unreasonable.
Further, even with the application
of these controls, national standards would probably be violated due to the
existence of natural wind-blown dust from dust storms.
Also the Act does not
allow the Agency to adopt a control strategy that is not adequate to attain
national standards (such as a strategy to implement only Ireasonab1e"
control s).
For these reasons, the Agency has sought an Amendment
from the Congress that would provide tbe Agency with flexibility in
dealing with AQCR's with fugitive dust problems.
Specifically, the
recommended Act amendment seeks additional time (generally 5 years but.
in some cases up to 10 years) for attainment of the national standards
for particulate matter in these areas and would require only the applica-
tion of reasonable and achievable controls on an as-expeditious-as-practicab1e
Such an amendment would eliminate the requirement of applying
unreasonable controls, such as chemical stabilization of farm lands.
It is anticipated that reasonable and achievable controls would be
determi ned on an area-by-area' basi s, dependi ng upon the degree of the
problem and the reasonableness of the controls needed to attain mationa1

SpeciaJ Study Cost Estimates of Attaining
Particulate Matter Standard in Southwest

Ca 1 i forni a/
San Joaqui n
Ari zonal
Phoeni x-Tucson.
New Mexico
El Paso
Measures Necessary to Achieve
Primary Standards

Speed control
Pave 281 mi les road.
Soil management1 4
Chemical stabilization3~
(820,400 acres) .
Construction contro12
Materials storage control
Feedlots contro13
1 ,914,000
$ NEG.
a. Speed control
b. Pave 138 miles road
c. Soil management
~. Chemical stabilization3~4
(301,700 acres) .
e. Construction contro12
f. Tailings control
$ NEG.

$ NEG.
Speed control
Pave 98 miles road
Soil management
Construction contro12
Chemical stabilization3~4
( 40 , 185 acres)

Speed control
Pave 84 miles road
Tailings control

Speed control
Tailings control
$ NEG.
IMay actually realize some profit if the cover crop can be sold.
2~ost would depend upon the amount of current "co",struction per year.
3Cost per year. ,
4Does not include cost of possible termination of farming operations.
due to cost of chemical stabilization. .

This paper has pointed out the various aspects of two similar but
indeed different air pollution problems.
Both fugitive emissions
(industrial) and fugitive dust emissions represent problems affecting
attainment of national standards. Both are difficult to quantify so as
to determine the relative magnitude of the problem.
Both have been
.generally overlooked in the past in relation to developing an effective
and widespread air pollution control program.
Both problems will gener-
ally require the use of non-conventional air pollution control measures.
Both are also becoming the subject of more intensive investigation as
more knowledge is. being gathered to implicate such emissions as signifi-
cant air pollution problems.
More specifically~ the Agency's Control Systems Laboratory has
numerous studies underway to investigate various fugitive emissions and
fugitive dust sources.
For example~ a $l~OOO~OOO four-year investiga-
tion of numerous "fugitive" type sources is presently under contract.
Such diffuse fugitive sources that will be investigated include combus-
tion sources~ organic and inorganic process operations~ materials storage~
rock crushing, strip mining~ grain harvesting and loading~ etc.
other contract investigations such as those examining the fugitive
emissions at the iron and steel industry~ iron foundries, copper and
lead smelters~ are currently being negotiated.
The information collected from these studies will assist this Agency,
as wefl~\. as the State and local agencies in controll ing II fugitive" sources
o"t"air 1tollution. The recommended amendments to the Clean Air Act which
EPA seeks from the Congress will provide the flexibility to establish
'. ,="
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an effective control program for fugitive dust and fugitive emission