Background Document for Revisions to Fine
Fraction Ratios Used for AP-42 Fugitive Dust
Emission Factors
Prepared by
Midwest Research Institute
(Chatten Cowherd, MRI Project Leader)
For
Western Governors' Association
Western Regional Air Partnership (WRAP)
1515 Cleveland Place, Suite 200
Denver, Colorado 80202
Attn: Richard Halvey
MRI Project No. 110397
February 1, 2006
Finalized November 1, 2006

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Responses to Comments Received on Proposed AP-42 Revisions
Commenter
and Date
Source
Category
Comment
Response
John Hayden,
National Stone,
Sand and Gravel
Association
(NSSGA); June
14,2006
Unpaved
Roads
NSSGA-
sponsored tests
(report dated Oct.
15, 2004) at
California
aggregate
producing plants
support the
proposed fine
fractions.
This comment reference a test report prepared
by Air Control Techniques for the National
Stone, Sand & Gravel Association, dated
October 4, 2004. The report gives the results of
tests to determine unpaved road emissions
factors for controlled (wet suppression only)
haul roads at two aggregate processing plants.
A variation of the plume profiling method using
TEOM continuous monitors with PM-2.5 and
PM-10 inlets was employed. Tests with road
surface moisture content below 1.5 percent
were considered to be uncontrolled.
Based on the example PM-10 concentration
profiles presented in the report, the maximum
roadside PM-10 dust concentrations in the
subject study were in the range of 300
micrograms per cubic meter. This is an order of
magnitude lower than the concentrations
typically found in other unpaved road emission
factor studies.
For the range of plume concentrations
measured in the NSSGA-sponsored test
program, an average fine fraction (PM-2.5/PM-
10 ratio) of 0.15 was reported. This fine fraction
value is consistent with the results of the MRI
dust tunnel testing in the same concentration
range. At plume concentrations more typical of
unpaved road emission factor studies, the
proposed value of 0.1 is applicable.
There is no need for any revisions to the
proposed changes to AP-42 as a result of the
cited study.
Hao Quinn,
Sacramento
Metro AQMD;
July 20, 2006
Paved vs.
unpaved
roads
For a particular
industrial facility,
the PM-10
emission factor
equations show
higher emissions
from paved roads
rather than
unpaved roads.
This comment does not relate to the
proposed changes to the fine particle
fractions.
It is possible that the emissions from a heavily
loaded paved road can exceed emissions from
an unpaved road with a low-to-moderate silt
content at the same industrial facility, even if
traveled by the same vehicles. This is the case
in the cited example, for which the paved road
silt loading is 70 g/m2.

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Commenter
and Date
Source
Category
Comment
Response
Brian Leahy,
Horizon
Environmental;
July 26, 2006
Unpaved
roads
The k value for
PM-2.5 does not
appear to have
changed in the
proposed
revision.
The latest (2003) approved AP-42 k values for
PM-2.5 in Table 13.2.2-2 are 0.23 and 0.27
Ib/VMT for industrial and public roads,
respectively. The proposed values are 0.15 and
0.18 Ib/VMT, which are equivalent to 10 percent
of the respective k values for PM-10.
There is no need for revisions to the proposed
changes to AP-42 as a result of this comment.
Shengxin Jin,
NYSDOT
Environmental
Analysis Bureau;
undated
Paved
roads
The conversion
of proposed k
values from
g/VMT to g/VKT
does not appear
correct
Regarding the revised k values for PM-2.5,
when the k value of 0.66 g/VKT is multiplied by
1.6 km/mi, it becomes 1.06 g/VMT, which
rounds to 1.1 g/VKT given in the proposed
revision. Because the k values are given only to
two significant figures, the converted values can
vary by up to five digits in the second figure,
depending on which direction the units
conversion is made. For example, when k value
of 1.1 g/VKT is divided by 1.6 km/mi, the
resulting value rounds to 0.69 g/VKT, but if 1.06
g/VKT is divided by 1.6 km/mi, the resulting
value rounds to 0.66 g/VKT.
There is no need for revisions to the proposed
changes to AP-42 as a result of this comment.


The stated silt
loading impact of
antiskid abrasive
does not appear
correct
This comment does not relate to the
proposed changes to the fine particle
fractions.
The commenter is correct in that 500 lb/mi of
antiskid abrasive with a 1% silt content
produces a silt loading in the range of 0.5 g/m2
rather than 2 g/m2. EPA may elect to make a
separate modification to correct this discrepancy
at a later time.

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Proposed Revisions to Fine Fraction Ratios
Used for AP-42 Fugitive Dust Emission Factors
ABSTRACT
A number of fugitive dust studies have indicated that the PM2.5 / PMi0 ratios
measured by US EPA federal reference method (FRM) samplers are significantly lower
than predicted by AP-42 emission factors. As a result, the PM2.5 emission estimates are
biased high. The controlled exposure study described in this report was conducted to
compare fine fraction ratios derived from FRM samplers to those derived from the
cyclone/impactor method that had been used to develop AP-42 emission factors for
fugitive dust sources. The study was conducted by the Midwest Research Institute using
the same cyclone/impactor samplers and operating method that generated the original
AP-42 emission factors and associated PM2.5 / PMi0 ratios. This study was sponsored by
the Western Regional Air Partnership.
The study found that concentration measurements used to develop PM2.5 emission
factors in AP-42 were biased high by a factor of two, as compared to PM2.5
measurements from FRM samplers. This factor-of-two bias helps to explain why
researchers have often seen a discrepancy in the proportion of fugitive dust found in
PM2.5 emission inventories and modeled ambient air impacts, as compared to the
proportion on ambient filter samples. This study also shows that the PM2.5 / PMi0 ratios
for fugitive dust should be in the range of 0.1 to 0.15. Currently, the ratios in AP-42
range from 0.15 to 0.4 for most fugitive dust sources.
It is recommended that the results of this study be used to revise the AP-42 PM2.5
emission factors for the following four fugitive dust source categories: paved roads,
unpaved roads (public and industrial), aggregate handling and storage piles, and
industrial wind erosion (AP-42 Sections 13.2.1, 13.2.2, 13.2.4, & 13.2.5, respectively).
Emission estimates for other fugitive dust producing activities, such as construction and
demolition will also be affected since they are based on these four source categories.
INTRODUCTION
The Dust Emissions Joint Forum (DEJF) of the Western Regional Air Partnership
(WRAP) is engaged in gathering and improving data pertaining to the PM2.5 and PMi0
components of fugitive dust emissions. Most of the PM2.5 emission factors in EPA's AP-
42 guidance for fugitive dust sources (USEPA, 2005) were determined by using high-
volume samplers, each fitted with a cyclone precollector and cascade impactor.
Typically, AP-42 recommends that PM2.5 emission factors for dust sources be calculated
1

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by using PMio emission factor equations along with PM2.5/PM10 ratios that have been
published by EPA in AP-42.
Beginning with the introduction of the cyclone/impactor method, it was realized
particle bounce from the cascade impactor stages to the backup filter may have resulted
in inflated PM2.5 concentrations, even though steps were taken to minimize particle
bounce. This led to an EPA-funded field study in the late 1990s (MRI, 1997) to gather
comparative particle sizing data in dust plumes downwind of paved and unpaved roads
around the country. The test results indicated that dichotomous samplers produced
consistently lower PM2.5/PM10 ratios than generated with the cyclone/impactor system.
Dichotomous samplers are federal reference method (FRM) samplers that are used to
measure compliance with federal air quality standards for particulate matter measured as
PM2.5 and PM10. Pending the eventual collection of additional data, the decision was
made that the true ratios would best be represented by an averaging of the
cyclone/impactor data with the dichotomous sampler data.
Based on the results of the EPA-funded field program, modifications were made to
the appropriate sections of AP-42 for dust emissions from paved and unpaved roads. The
PM2.5/PM10 ratio for emissions from unpaved roads (dominated by fugitive dust) was
reduced from 0.26 to 0.15, and the PM2.5/PM10 ratio for the dust component of emissions
from paved roads was reduced from 0.46 to 0.25. In the 2003 revision to AP-42, the non-
dust component of paved road emissions was assigned a PM2.5/PM10 ratio of 0.76,
accounting for vehicle exhaust and brake and tire wear.
Subsequent to the modifications of the PM2.5/PM10 ratios in AP-42, additional field
test results (mostly from ambient air samplers) indicated that further reductions to the
ratios were warranted (Pace, 2005). For example, ambient air monitoring data suggested
that the fine fraction dust mass is of the order of 10 percent of the PM10 mass, based on
chemical fingerprinting of the collected fine and coarse fractions of PM10 impacted by
dust sources. It is important to note, however, that particle size data applicable to fugitive
dust emission factors should be gathered either from the emissions plume or near the
point where emissions are generated (within 10 m of the downwind edge of the source).
METHODOLOGY
This led DEJF to fund Midwest Research Institute (MRI) in conducting a controlled
study of particle sizing in dust plumes. The objective of the study was to resolve the fine
particle bias in the cyclone/impactor system, so that reliable PM2.5/PM10 ratios could be
developed for as many dust source categories as possible. For this purpose, an air
exposure chamber connected to a recirculating supply air stream was used in conjunction
with a fluidization system for generating well-mixed dust plumes from a variety of
western soils and road surface materials. R&P Model 2000 Partisol samplers were
selected as the ground-truthing FRM samplers for PMi0 and PM25.
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This study was performed in two phases (see below), as described in the attached test
report (Cowherd and Donaldson, 2005). The test report serves as the background
document to support the recommended revisions to AP-42, and it contains all the quality
assurance procedures and results of the testing.
Phase I - Compare PM2.5 Measured by Cyclone/lmpactor to FRM Sampler
In the first testing phase of the project, PM2.5 measurements using the high-volume
cascade impactors were compared to simultaneous measurements obtained with EPA
FRM samplers for PM25. As stated above, these tests were conducted in a flow-through
wind tunnel and exposure chamber, where the PM10 concentration level and uniformity
were controlled. The results of the tests provided the basis for quantifying more
effectively any sampling bias associated with the cascade impactor system.
Phase 2 - Compare PM2.5 to PM™ Ratios for Different Geologic Soils
With the same test setup, a second phase of testing was performed with reference
method samplers, for the purpose of measuring PM2.5 to PMi0 ratios for fugitive dust
from different geologic sources in the West. This testing provided needed information on
the magnitude and variability of this ratio, especially for source materials that are
recognized as problematic with regard to application of mitigative dust control measures.
RESULTS
The tests that were performed are listed in Tables 6 and 7 of the attached report. The
Phase I tests were performed in March and April of 2005. The Phase II tests were
performed in June through August of 2005. A total of 100 individual tests were
performed, including 17 blank runs (for quality assurance purposes). The raw and
intermediate test data are summarized in the tables presented in Appendix A of the
attached report.
Based on the 100 wind tunnel tests that were performed in the wind tunnel study, the
findings support the following conclusions:
1.	PM2.5 concentrations measured by the high-volume cyclone/impactor system
used to develop AP-42 emission factors for fugitive dust sources have a positive
bias by a factor of 2, as compared to the PM2.5 concentration measurements from
reference-method samplers (see Figure 1). The geometric mean bias is 2.01 and
the arithmetic mean bias is 2.15.
2.	The PM2.5 bias associated with the cyclone/impactor system, as measured under
controlled laboratory conditions with dust concentrations held at nearly steady
values, closely replicates the bias observed in the prior EPA-funded field study
at distributed geographic locations across the country.
3

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3.	The PM2.5/PM10 ratios measured by the FRM samplers in the current study for a
variety of western soils show a decrease in magnitude with increasing PMi0
concentration (see Figure 2). Soils with a nominally spherical shape are
observed to have somewhat lower ratios (at given PMi0 concentrations) than
soils with angular shape. A very similar dependence of PM2.5/PM10 ratio on
PM10 concentration was also observed in the prior field study that used
dichotomous samplers as FRM devices.
4.	The test data from the current study support a PM2.5/PM10 ratio in the range of
0.1 to 0.15 for typical uncontrolled fugitive dust sources (see Figure 2). The
PM2.5/PM10 ratio of 0.1 is also supported by numerous other studies including
the prior EPA-funded field study that used dichotomous samplers as reference
devices. It is possible that a ratio as low as 0.05 (as was found in the prior field
tests of unpaved road emission factors) might be appropriate for very dusty
sources, but this would require extrapolation of the current test data from the
wind tunnel study.
DISCUSSION
Peer Review
The test report on the wind tunnel study (Cowherd and Donaldson, 2005) was issued
first in draft form for external peer review. Three peer reviewers (having no prior contact
with the study) were selected by the DEJF: Patrick Gaffney (California Air Resources
Board), John Kinsey (U.S. Environmental Protection Agency), and Mel Zeldin (Private
Consultant). In addition, peer review comments were provided by Duane Ono (Great
Basin UAPCD) and Richard Countess (Countess Environmental) who helped to develop
this study. After the review comments on the draft test report were received, comment/
response logs were prepared by MRI, listing each comment and the response to each
comment. The next step was to modify the draft test report in accordance with the
responses to the review comments. The final test report was issued on October 12, 2005.
Recommended Particle Size Ratios
Based on the results of the WRAP/DEJF study (see attached test report) and the prior
EPA-funded field study, it is proposed that new PM2.5/PM10 ratios be adopted for several
categories of (uncontrolled) fugitive dust sources, as addressed in AP-42. The proposed
ratios (given to the nearest 0.05) are summarized in Table 1. It should be noted that these
fine fraction ratios and the emission factors could change in the future if field studies
show other differences than those identified through this study.
The proposed PM2.5/PM10 ratios in Table 1, apply to dry surface materials, having
moisture contents in the range of 1% or less. Such materials when exposed to energetic
disturbances produce dust plumes with core PMi0 concentrations in the range of 5,000
micrograms per cubic meter, near the point of emissions generation. The wind tunnel test
data show that dust plumes with lower core concentrations have higher PM2.5/PM10
4

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ratios. This might occur, for example, at higher soil (or other surface material) moisture
contents. However, the emissions from such sources typically are substantially lower
with correspondingly less impact on the ambient environment.
Table 1. Proposed Particle Size Ratios for AP-42
Fugitive dust source category
AP-42
section
PM2 5/PM10 Ratio
Current
Proposed
Paved Roads
13.2.1
0.25
0.15
Unpaved Roads (Public & Industrial)
13.2.2
0.15
0.1
Construction & Demolition
-
0.208 1
0.1
Aggregate Handling & Storage Piles
13.2.4
0.314
0.1 (traffic)
0.15 (transfer)
Industrial Wind Erosion
13.2.5
0.40
0.15
Agricultural Tilling
-
0.222 2
0.2 (no
change)
Open Area Wind Erosion
-
-
0.15
Notes:
1	AP-42 Section 13.2.3 suggests using emission factors for individual dust
producing activities, e.g., materials handling and unpaved roads. The WRAP
Fugitive Dust Handbook recommends using a fine fraction ratio of 0.208 from
a report prepared for the US EPA, Estimating Particulate Matter Emissions
from Construction Operations (MRI, 1999).
2	Agricultural tilling was dropped from the 5th edition of AP-42. The WRAP
Fugitive Dust Handbook recommends using a fine fraction ratio of 0.222 from
Section 7.4 of the California Air Resources Board's Emission Inventory
Methodology (CARB, 2003).
The justification for each proposed ratio in Table 1 is provided by source category in
the sections below. In each case, reference is made to test reports that contain supporting
data.
Paved Roads
For the dust component of particulate emissions from paved roads, a PM2.5/PM10
ratio of 0.15 is recommended. The proposed ratio is based on the factor-of-two bias in
the cyclone/impactor data for the wind tunnel study, which tested western soils and road
surface materials. As shown in Table 1, the current AP-42 ratio is 0.25. It should be
recalled that the nondust component of paved road particulate emissions has been
assigned a much higher ratio of 0.76, based on inputs from the EPA's MOBILE 6 model.
5

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Unpaved Roads
For the dust component of particulate emissions from unpaved roads, which
dominates the total particulate emissions from this source category, a PM2.5/PM10 ratio of
0.1 is recommended. The proposed ratio is justified from the test results of the wind
tunnel study for a variety of western surface materials. It is also consistent with the
factor-of-two bias in the cyclone/impactor data from the wind tunnel study and with the
results of the prior field study that used dichotomous samplers as FRM devices (MRI,
1997).
Construction and Demolition
The dust component of particulate emissions from construction and demolition
dominate the total particulate emissions from this source category. A PM2.5/PM10 ratio of
0.1 is recommended for dust emissions from construction and demolition. The proposed
ratio is justified by the fact that the dominant dust source associated with construction
and demolition projects is emissions from vehicle travel over unpaved surfaces. This is
shown by case studies that calculate particulate emissions from representative
construction activities (road, building, and nonbuilding construction). For example, the
fine fraction ratio for scraper travel averages about 0.2 (Muleski et al., 2005), before
correcting for the factor-of- two bias in the cyclone/impactor system. Moreover this
includes the diesel emissions that are contained within the fine fraction component.
It should be noted that if large open areas are disturbed (such as in land clearing) and
left unprotected, and the areas are exposed to high winds, open area wind erosion can
also be an important contributor to dust emissions from this source category. The
recommended fine fraction ratio identified below should be used for the open area wind
erosion component.
Aggregate Handling and Storage Piles
Although usually not a major source in comparison with traffic around storage piles,
the transfer of aggregate associated with bucket loaders and unloaders or conveyor
transfer points is addressed directly in this section of AP-42. A PM2.5/PM10 ratio of 0.15
is recommended for transfer operations. This is half the current value in AP-42 and
reflects adjustment for the factor-of-two bias in the cyclone/impactor test results.
The dominant dust component of particulate emissions from aggregate handling and
storage piles typically consists of loader and truck traffic around the storage piles. AP-42
refers the reader to the unpaved roads section to find appropriate emission factors. A
PM2.5/PM10 ratio of 0.1 is recommended for this source. The proposed ratio is consistent
with that recommended above for traffic on unpaved surfaces.
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Industrial Wind Erosion
For the dust component of particulate emissions from industrial wind erosion, a
PM2.5/PM10 ratio of 0.15 is recommended. Industrial wind erosion is associated with
crushed aggregate materials, such as coal or metallic ore piles. Examples would include
open storage piles at mining operations. The proposed ratio is justified by portable wind
tunnel tests of industrial aggregate materials which produced PM2.5/PM10 ratios averaging
0.4, as indicated by the current AP-42 fine fraction ratio given in Table 1. When these
results are corrected for the bias associated with the cyclone/impactor system at very high
PM10 concentrations observed in the effluent from the portable wind tunnel (exceeding
10,000 (j,g/m3), the result is 0.15.
Agricultural Tilling
For the dust component of particulate emissions from agricultural tilling and related
land preparation activities, which dominates the total particulate emissions from this
source category, no new PM2.5/PM10 ratio can be recommended at this time, because of
the lack of published test data. However, the current factor of 0.2, as listed in Table 1,
appears to be generally consistent with the results of the current wind tunnel tests. It was
found that the agricultural soils tested in the wind tunnel produced slightly higher ratios
than the other test materials. In addition, the dust plume core concentrations from
agricultural operations are generally observed to be less intense because of the lower
equipment speeds involved and the lack of repeated travel over the same routes.
Open Area Wind Erosion
For the dust component of particulate emissions from open area wind erosion (not
currently addressed in AP-42), a PM2.5/PM10 ratio of 0.15 is recommended. Open area
wind erosion is associated with exposed soils that have been disturbed, removing the
protection afforded by natural crusting. Examples would include freshly tilled
agricultural fields prior to planting of crops. The proposed ratio is justified by wind
tunnel tests of exposed soils (MRI, 1994), which produced PM2.5/PM10 ratios averaging
0.3. When these results are corrected for the bias associated with the cyclone/impactor
system, the ratio becomes 0.15. This is consistent with the PM2.5/PM10 ratios in the range
of 0.12 measured during dust storms on Owens Dry Lake (Ono, 2005).
Specific Revisions to AP-42
This section presents a listing of specific revisions to AP-42, for the purpose of
incorporating the proposed PM2.5/PM10 ratios. As shown in Table 2, five subsections of
AP-42 Section 13.2, Fugitive Dust, are impacted by the proposed changes. However, one
of the five sections (13.2.3, Heavy Construction Operations) is impacted only indirectly
because it refers to other sections of AP-42 for fugitive dust emission factors.
7

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In most cases, the change in the PM2.5/PM10 ratio is accomplished by changing the
appropriate PM-2.5 particle size multiplier (k-factor) for the respective emission factor
equation. In addition, the changes need to be referenced to the WRAP test report
(Cowherd and Donaldson, 2005).
Table 2. Specific revisions to AP-42 that are incorporated
into the AP-42 sections included in Attachment A.
Source
category
Sub-
section
Title
Revision
Comments
13.2.1 Paved
Roads
13.2.1.3
Predictive
Emission Factor
Equation
In Table 13.2.1-1, reduce
k values for PM-2.5 by 40
percent, e.g., the new
value is 1.1 g/VMT (and
equivalent values for the
other units)
Add ref. number
for WRAP test
report
13.2.1.5
Changes since
Fifth Edition
Modify statement (1) to
reflect change in fine
fraction


References
Add WRAP test report as
Ref. 22

13.2.2
Unpaved
Roads
13.2.2.2
Emission
Calculation and
Correction
Parameters
In Table 13.2.2-2, reduce
k values for PM-2.5 by
33%, e.g., the new value
is 0.15 Ib/VMTfor
industrial roads and
0.18 Ib/VMT for public
roads (and equivalent
values for the other units)
Add ref. number
for WRAP test
report
13.2.2.4
Updates since
Fifth Edition
Add sentences describing
change in fine fraction



References
Add WRAP test report

13.2.3 Heavy
Construction
Operations


No changes required
Refers to other
AP-42 sections for
emission factors
13.2.4
Aggregate
Handling and
Storage Piles
13.2.4.3
Predictive
Emission Factor
Equations
In k-factor table for
Equation 1 for transfer
operations, change PM-
2.5 multiplier to 0.053
(dimensionless)
Add ref. number
for WRAP test
report

References
Add WRAP test report

13.2.5
Industrial Wind
Erosion
13.2.5.2
Emissions and
Correction
Parameters
In k-factor table for
Equation 1, change
PM-2.5 multiplier to 0.075
(dimensionless)
Add ref. number
for WRAP test
report

References
Add WRAP test report

8

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CONCLUSION
This study found that concentration measurements used to develop PM2.5 emission
factors for AP-42 were biased high by a factor of two, as compared to PM2.5
measurements from FRM samplers. This factor-of-two bias helps to explain why
researchers have often seen a similar discrepancy in the proportion of fugitive dust found
in PM2.5 emission inventories and modeled ambient impacts, as compared to the
proportion observed on ambient filter samples. This study also shows that the PM2.5 /
PM10 ratios for fugitive dust should be in the range of 0.1 to 0.15. Currently, the fine
fraction ratios in AP-42 range from 0.15 to 0.4 for most fugitive dust sources.
It is recommended that the results of this study by used to revise the AP-42 PM2.5
emission factors for the following four fugitive dust source categories: paved roads,
unpaved roads (public and industrial), aggregate handling and storage piles, and
industrial wind erosion (AP-42 Sections 13.2.1, 13.2.2, 13.2.4, & 13.2.5, respectively).
Emission estimates for other fugitive dust producing activities, such as construction and
demolition, will also be affected since they are based on these four source categories. It
is recommended that revisions to the current AP-42 sections for these fugitive dust
sources be adopted as shown in Attachment A to this report.
IMPLICATIONS
The proposed revisions to AP-42 are needed to ensure the most accurate PM2.5 and
PM10 fugitive dust emissions inventories that are possible for regional haze regulatory
purposes, given the available resources and the significant contribution of fugitive dust to
visibility impairment. In particular, the revisions will affect the quantity of dust
apportioned to the fine (PM2.5) versus coarse (PM2.5-10) size modes, which have
significantly different effects on visibility and long-range transport potentials. This will
reduce PM2.5 emission estimates for fugitive dust sources to about half their current level.
It will also increase the coarse-mode size fraction for fugitive dust, which would be
important in the event that a PM coarse standard is adopted by the US EPA and emission
inventories are developed.
The revisions will be helpful in developing accurate emission inventories for PM
nonattainment, maintenance, and action plan areas throughout the country. Finally, the
proposed modifications to the fine fractions associated with EPA's AP-42 emission
factors will ensure widespread availability of the most recent and accurate scientific
information.
References
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Cowherd, C. and J. Donaldson. 2005. Analysis of the Fine Fraction of Particulate
Matter in Fugitive Dust. Final report prepared for the Western Governors' Association,
Western Regional Air Partnership (WRAP), MRI Project No. 110397, October 12, 2005.
[Describes wind tunnel study to determine fine fraction ratios]
Midwest Research Institute. 1994. OU3 Wind tunnel Study: Test Report. Prepared for
EG&G Rocky Flats, Golden CO. [Describes portable wind tunnel tests of emissions
from soils and sediments]
Midwest Research Institute. 1997. Fugitive Particulate Matter Emissions. Final report
prepared for the U.S. Environmental Protection Agency, Office of Air Quality Planning
and Standards. Research Triangle Park NC. April, 1997. [Prior emission factor field
study for paved and unpaved roads, comparing performance of cyclone/impactor
system with reference method samplers for PM2.5]
Muleski, G. E., C. Cowherd, and J. S. Kinsey. 2005. "Particulate Emissions from
Construction Activities, " J. Air & Waste Manage. Assoc. 55:772-783. [Summarizes
field test results for emissions from major components of construction projects]
Ono, Duane. 2005. "Ambient PM2.5/PM10 ratios for Dust Events from the Keeler
Dunes." Great Basin UAPCD, Bishop, CA. [Describes FRM test results for high-
wind events on Owens Dry Lake]
Pace, T. G. 2005. "Examination of Multiplier Used to Estimate PM2.5 Fugitive Dust
Emissions from PMio" Presented at the EPA Emission Inventory Conference. Las
Vegas NV. April 2005. [Summarizes other field studies that can be used to develop
PM2.5/PM10 ratios for fugitive dust emissions]
USEPA. 2005. Compilation of Air Pollutant Emission Factors, AP-42. 6th Edition.
Research Triangle Park, NC. [EPA's emission factor handbook]
CARB, 2003. Emission Inventory Procedural Manual Volume III: Methods for
Assessing Area Source Emissions, California Air Resources Board, Sacramento, CA.
November. [Summarizes the recommended calculation procedures for agricultural
emissions and other sources]
Midwest Research Institute. 1999. Estimating Particulate Matter Emissions from
Construction Operations. Prepared for USEPA, Research Triangle Park NC, September.
[Gives field test results for construction operations]
10

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Figure 1. Phase I test results show that the Cyclone/ Impactor method measured PM2.5 concentrations that were two times higher than
those measured by Federal Reference Method samplers when simultaneously exposed to the well-mixed dust environment in the wind
tunnel.
PM 2.5 Ratios for Cyclone and Partisols
4.5
IO
CNJ
3.5
o
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ra
c 3

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O
TO

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0.5

A A
'J
~
~ AZ Fine
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A Owens DLB
<
.A ¦
2	3
PM 10 Concentration (mg/m3)
11

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Figure 2. Phase II tests show that the PM2.5/PM10 ratio decreased with increasing PM concentrations, and could be expected to be in
the range of 0.1 at concentrations that are typical of fugitive dust emission plumes.
PM 2.5 I PM 10 Ratio vs PM 10 Concentration
0.000 1.000 2.000 3.000 4.000 5.000
PM 10 Concentration (mg/m3)
6.000
7.000
i.OOO
~	AZ Ag Soil
¦ Knik River
Sediments
Las Cruces Landfill
Road
X Thunder Basin Mine
•	AZ Alluvial Channel
A Radium Springs
+ Saltan Sea
12

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