Environmental Protection Technology Series
FIELD TESTING OF EMISSION CONTROLS FOR
ASBESTOS MANUFACTURING WASTE PILES
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-098
May 1977
FIELD TESTING OF EMISSION CONTROLS FOR
ASBESTOS MANUFACTURING WASTE PILES
by
Colin F. Harwood
Paul K. Ase
IIT Research Institute
Chicago, Illinois 60616
Contract No. 68-02-1872
Project Officer
Mary K. Stinson
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Edison, New Jersey 08817
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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This report has been reviewed by the Industrial Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policies of the U, S. Environmental Protection Agency, nor does
mention of traxle names or commercial products constitute endorsement or
recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution
control methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL^Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and economically.
These studies were undertaken to perfprm field testing of control
technology to abate emissions from asbestos cement waste disposal activities.
Effectiveness of the selected control options has been evaluated and a total
annual cost of applying these controls to a model typical plant has been
estimated.
Such information will be of value to EPA's enforcement program (Office
of Air Quality Planning and Standards) and to the Office of Toxic Substances,
Within EPA's R&D program the information will be used in the Industrial
Program, lERL-Ci, and in the Health Effects Laboratory, IERL-RTP. Other
groups active in studies with asbestos such as NIEHS, NIOSH, OSHA, Bureau of
Mines, Mining Enforcement and Safety Administration, and Department of
Transportation will also use this report. Other users of the report will be
asbestos mining, milling, and manufacturing industries as well as other
mineral industries where asbestos is a contaminant.
For further information concerning this subject the Industrial Pollution
Control Division should be contacted.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
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ABSTRACT
Abatement of fugitive emissions from asbestos cement waste disposal
activities has been studied. The primary sources of asbestos emissions are,
(1) transfer of baghouse fines to the dump, (2) crushing and leveling of
waste on the fines, (3) active dump areas, (4) inactive dump areas. The
emission control options used in other industries were reviewed. Those
applicable to asbestos cement waste were analyzed for cost effectiveness
using engineering estimation techniques applied to a model typical plant. It
was estimated that bagging of the fine waste would reduce dumping emissions
by 80%, while a soil-vegetative cover would reduce the long-term emissions by
90%. Application of the three control options would reduce the emissions by
87% at a total annual cost of $17,850 for the model typical plant. Field
testing of the control options indicated that the assumptions made were
reasonable and that the emissions were in line with those predicted. Back-
ground asbestos levels in the ambient air were found to be high and to exist
both upwind and downwind of the plant for considerable distances (10 km).
Emissions from small test plots were too low to be measured but the stability
of the chemically stabilized and the soil-vegetated covers were excellent.
Despite the high alkalinity of asbestos waste (pH 12), vegetation was grown
on the soil to give a 95% cover, far in excess of the coverage required to
prevent soil erosion.
This work was submitted in fulfillment of IITRI Project Number C6338,
EPA Contract Number 68-02-1872, by the IIT Research Institute under the
sponsorship of the U. S. Environmental Protection Agency. This report covers
the period March 20, 1975 to June 19, 1976 and work was completed as of
June 30, 1976.
IV
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CONTENTS
Foreword Ill
Abstract iv
Figures vi
Tables viii
Acknowledgment x
1. Introduction 1
2. Conclusions 4
3. Recommendations . , 6
4. Identification of Emission Control Options ... 8
5. Analysis of Emission Control 22
6. Field Test Program 40
7. Field Tests Results and Discussion 65
8. Appendices 112
9. References 133
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FIGURES
Number
1 Asbestos waste disposal without emission controls ........ 11
2 Asbestos waste disposal process treatment options for fines ... 12
3 Asbestos waste disposal process treatment options for
aggregates ...................... .* ' * * 13
4 Isopleths for one year of uncontrolled inactive pile emissions . . 29
5 Least cost combinations of emission control options ....... 38
6 Chemically treated pile ..................... 42
7 Soil vegetation covered pile .................. 43
8 Reject pipe at the dump ..................... 45
9 High volume sampler stations for area survey at Johns-Manville
plant, Denison, Texas ..................... 46
10 Location of high volume sampler stations for survey in general
area of Johns-Manville plant, Denison, Texas ......... 47
11 High volume sampling stations at the plant dump, Johns-Manville,
Denison, Texas ........................ 49
12 Field test piles site, Johns-Manville, Denison, Texas ...... 52
13 Distribution of fibers > 1.5 ym upwind and downwind of the
plant ............................. 67
14 Distribution of asbestos mass concentration upwind and downwind
of the plant ......................... 68
15 Asbestos concentration distribution upwind and downwind of the
plant as predicted by Climatological Dispersion Model ..... 69
16 Fiber concentrations vs. time upwind and downwind from test
piles ............................. 76
17 Comparison of fiber concentration and chrysotile mass
concentration for emissions samples collected in vicinity of
plant dump .......... ..... ........... 83
18 Cumulative distribution of fibers by diameter .......... 85
19 Cumulative distribution of fibers by length ........... 86
20 Concentration of the chemical stabilizer in the surface of
Pile 3 shown as a function of time .............. 92
21 Comparison of daily rainfall and surface mositure on test piles
over a six month period .................... 96
22 Comparison of average surface moisutre on test piles at
different intervals of time after precipitation ........ 97
23 Comparison of vegetation coverage on Pile 2 and rainfall over
six month period .................. ..... 105
24 Comparison of soil electrical conductivity with soil pH on
Pile 2. Values measured for sandy loani are included for
reference ........................... 107
vi
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FtGtIRES (Continued)
Number
25 Typical comparison of channelling on a non-vegetated
pile (control pile) ..... 109
26 Typical Comparison of channelling on vegetated pile ....... 110
27 Collection of particles by free falling water drops ....... 113
28 Load lugger modified With spraying system 114
29 Landfill operation ... i ...'.*... 122
vii
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TABLES
Number Page
1 Asbestos Cement Waste Emission Control Options 9
2 Some Size Enlargement Methods and Applications 15
3 Chemical Stabilizers 19
4 Emission Rates of Uncontrolled Inactive Pile at Several Ages . . 25
5 Asbestos Fiber Emission Concentration as a Function of
Affected Area 27
6 Summary of the Control Options 30
7 Chemical-Vegetative Hydroseeding Costs 35
8 Emission Control Options - Least Cost Combinations 39
9 Emission Sources and Control Options 41
10 Desirable Stabilizer Properties ... 54
11 Effect of Chemical Treatments on Mechanical Properties of
Asbestos Waste and Retention of Treatments after Simulated
Rainfall 55
12 Waste Pile Tests and Measurements 57
13 Background Asbestos Concentration, Upwind and Downwind of the
Johns-Manville Plant Dump, Denison, Texas; Results of OM
Fiber Counts and AA Elemental Analysis 66
14 Plant Area Background Particle Counts Measured by Condensation
Nuclei Counter 70
15 Optical Microscope Measurement of Fiber Emissions from Static
Asbestos Cement Waste Test Piles, Sampled on Aug. 21, 1975 . . 72
16 Optical Microscope Measurement of Fiber Emissions from Static
Asbestos Cement Waste Test Piles, Sampled on Oct. 13, 1975 . . 73
17 Optical Microscope Measurement of Fiber Emissions from Static
Asbestos Cement Waste Test Piles, Sampled on Nov. 17, 1975 . . 74
18 Optical Microscope Measurement of Fiber Emissions from Static
Asbestos Cement Waste Test Piles, Sampled on Dec. 11, 1975 . . 75
19 t Test of Average Upwind and Average Downwind Fiber
Concentration Measurements 77
20 Control of Emissions from Fines Transfer Operations at the
Dump; Measurements made with Royco Particle Counter 79
21 Comparison of Electron Microscope, Optical Microscope, and
Atomic Absorption Data for Samples from Five Locations
at the Johns-Manville Plant, Denison, Texas 80
22 Atomic Absorption Concentration Measurements and Optical
Microscope Fiber Counts of Asbestos Emissions Collected
on Millipore Type AA Membrane Filters; Air Samples
Collected on Premises of Johns-Manville Plant, Denison>
Texas 82
viii
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TABLES (Continued)
Number Page
23 Analysis of Selected Individual Fibers for Crystallinity
and Elemental Composition I/ Electron Microscopy; Samples
Collected on Hi-Vol Membrane Filters at Asbestos Cement
Waste Dump 84
24 Comparison of Fiber Aspect Ratios from Several Dump
Emission Sources 87
25 Comparison of Magnesium Concentration and Magnesium to Calcium
Ratio for Bulk Waste Fines (Whole), Waste Fines < 200 Mesh
(75 urn), and for Samples Collected on Hi-Vol Filters at the
Dump 89
26 Asbestos Emission Concentrations and Emission Rates for Dump
Emission Sources 90
27 Wet Sieve Analysis of the Control Pile and Chemically
Treated Pile 94
28 Penetration Resistance 95
29 Shelby Tube Bulk Density 99
30 Settling Plate Measurements 100
31 Soil Analysis of Test Samples 102
32 pH Measurements of Sandy Loam Soil Cover on Pile after
Four Months 104
ix
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ACKNOWLEDGMENT
The cooperation of Johns-Manvilie In the performance of this contract is
gratefully acknowledged. A sub-contract to Johns-Manville was negotiated
through John Collins and John Mitchell of the corporate headquarters in
Denver, Colorado. The plant manager at the Johns-Manville plant in Denison,
Texas was Mr. L. I. Richards. A special thanks is offered to
Mr. J. T. Armstrong, Environmental Engineer at the Denison plant, who
executed his responsibilities on the program in an efficient and conscien-
tious manner even while pressed to perform his normal plant functions.
Dr. W. A. Berg of Colorado State University acted as Consultant
Agronomist to the program. His specialized knowledge was invaluable to the
success of the program.
David K. Oestreich of the EPA nurtured the program into existance, his
enthusiasm and interest in the program was appreciated. Mary K. Stinson
assumed the responsibilities of the EPA Project Officer at the mid-point of
the program. She very quickly realized the importance of the study and has
strived to maintain the program's objectivity.
A large number of IIT Research Institute staff have contributed to the
program which was administered out of the Fine Particles Research Section;
Manager, Mr. J, D. Stockham. The program was guided technically by
Dr. Colin F. Harwood while Paul K. Ase served as Project Leader. The cost
effectiveness analysis was very ably conducted by Jim Huff and Linda Huff.
Field studies were conducted with the assistance of Erdmann Luebcke,
Paul K< Ase, Colin F. Harwood, and E. Aleshin. Soil studies were performed
by E. Aleshin and D. Fedor. Electron and optical microscope determinations
were made by George Yamate, Dr. Anant Samudra, David Jones and Usha Maru.
Atomic absorption measurements were made by P. Lai.
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SECTION 1
INTRODUCTION
OBJECTIVE
Asbestos cement manufacturing waste piles are frequently located in
high-density population areas. It has been recognized by the
U. S. Environmental Protection Agency that the presence of asbestos waste
dumps in these areas might constitute a health hazard to those people living
in the vicinity of the dumps.1
The objectives of this program were two fold. The first was to define
those procedures involved with the disposal of asbestos cement waste which
were most significant as atmospheric emission sources and to consider methods
of controlling their emissions. Then those methods found to be most cost
effective were to be tested in a field demonstration program.
The asbestos industry is not a small industry. World consumption
currently stands at about 5 million tons per year. Approximately 1 million
tons are used annually in the United States. Asbestos cement products
account for 70 percent of the total United States usage. Products made from
asbestos cement include pipe, wall siding, roof shingles, wallboard, and
insulation products. It is estimated that 5-10 percent of the product
material is dumped as scrap, of which 10 percent is fine dust and 90 percent
coarse scrap from trimmings and breakage and from products which have failed
quality assurance testing.
The quantity of waste material from the asbestos cement industry is
readily estimated. Of the 700,000 tons of asbestos used in asbestos cement
products annually, 7.5 percent is scrapped. Since asbestos products usually
contain only 25 percent asbestos, then the total quantity of asbestos cement
products disposed of as scrap per annum is about 210,000 tons.
Over the years, the scrap products have grown into substantial waste
piles. Dumping of the scrap is usually carried out with little effort to
control the fugitive emissions associated with the various stages of the
waste transfer and dumping operations. Frequently, they are located in
industrial areas of high population and could constitute a health hazard to
the local residents. The hazard associated with such piles is difficult to
assess because the effects may not become apparent until some 20-40 years
after the onset of the exposure.
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ASBESTOS CEMENT PIPE PRODUCTION
The asbestos cement products industry is the largest user of asbestos
accounting for 70 percent of all the asbestos used. The largest segment of
the industry is the production of cement pipe. Fibrous asbestos in the
cement gives it a high tensile strength and provides a less costly, easier to
use alternative to other types of pipes which have been largely superceded by
asbestos cement. Pipe is made in diameter range from 75 cm to 120 cm with
lengths up to 4 meters.
Applications for the pipe are varied and include:
Water transport potable, drainage and irrigation
Sewage
Industrial products
Air/gaseous products heating, cooling, gas-venting
Asbestos cement is composed of Portland cement (40-55 percent), finely
ground silica flour (24-33 percent), and well separated asbestos fibers
(15-35 percent). Most asbestos cement products are made by a wet mechanical
process although dry and extrusion methods are also practiced.
The wet process equipment is somewhat similar to that used in paper
manufacturing. Asbestos is fluffed and separated in a willow and is then
mixed with finely ground silica sand and Portland cement. Water is added to
form a homogeneous slurry and the slurry is fed on a moving felt conveyor.
The water is drawn through the felt by vacuum and a continuous asbestos
cement sheet is formed. The sheet is wound onto a cylindrical mandrel until
the pipe reaches the desired thickness. The pipe is then loosened electro-
lytically by producing gases between the mandrel and the newly formed pipe.
After a short time, the mandrel is removed and the pipe cured in an autoclave.
After curing, the pipe is cut to size and the ends are trimmed in a
lath. Finally, the pipe is tested to ensure that it can withstand given
flexibility and pressure standards. Other sections of pipe are cut to form
angular sections and machined to facilitate junctions. All of the pipe
fragments and failed pipe sections are collected in containers and removed
to the dump. Each cutting, sawing, and trimming station is swept by an air
extraction system which conveys the dust to a central baghouse dust collector.
Fine dust collected in the baghouse is removed periodically and taken to the
dump to join the larger waste fragments.
SELECTION OF THE CONTROL TECHNIQUES
In order to provide a rational basis for the selection of the emission
control techniques to field tested, a hypothetical model plant was invoked.
The model plant was based on features of known existing plants with the
exception that it was assumed that no emission control was currently
practiced. Based on this model plant, a theoretical analysis was developed
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using the standard environmental engineering cost-estimating procedures from
which recommendations were made on the control technique to be used to obtain
a given degree of emission control for a given level of cost.
Initially, a list of emission control options were assembled and
examined as candidate techniques for the field studies. Then the degree of
control to be anticipated from the application of each technique was esti-
mated. This estimate was combined with an estimate of the cost to obtain
cost effectiveness data. The individual control techniques were then
combined in control strategies combining several techniques to cover each
of the individual sources at the model plant.
Resulting from the analysis of the cost effectiveness of the various
control techniques and control strategies, a least cost curve was developed.
The curve was used to find the cost to obtain a certain level of emission
control and the control strategies which must be used to achieve the
selected level of control. Then the options to be field tested were selected
from the least cost curve.
FIELD TESTING OF CONTROL OPTIONS
Field testing of the control options was performed at the Johns-Manville
asbestos cement pipe plant in Denison, Texas. The facility is located in a
rural area with an excess of land upon which the waste pile is located.
Waste pipe and baghouse waste fine material are dumped on a daily basis in an
open dump. A bulldozer is used on a monthly basis to crush the pipe and
smooth the fines over the pipe to form a level area. Thus, four main sources
of emissions were identified: waste dumping; crushing and leveling; a new,
active dump area; and an extensive, old, inactive area.
Four options were selected for field testing. Two options were concerned
with the transfer of the fine baghouse waste to dump; they were bagging the
waste in polyethylene bags and forming a slurry of the waste. Two options
were selected for stabilizing the waste piles; for the active pile a
temporary chemical stabilizer was selected, while for the inactive pile a
permanent soil-vegetative cover was tested.
Field tests at the site were conducted to determine the asbestos
emission background levels over a broad area surrounding the plant. Tests at
the dump site were conducted to establish the emission levels from the dump
and also the degree of emission control to be expected from the controls
applied to the dumping activities. Emission testing was also attempted on
small test piles using the chemical stabilizer and soil-vegetative covers.
The stability of the test piles was assessed using soil mechanics test
procedures.
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SECTION 2
CONCLUSIONS
Asbestos cement waste disposal piles have been recognized as a signifi-
cant source of asbestos emissions into the ambient air. Four dump mechanisms
for asbestos emissions have been identified: (1) transfer operations as the
materials are dumped, (2) crushing and leveling the waste to form piles,
(3) active or new dump areas subject to vehicular traffic, and (4) inactive,
long term, undisturbed waste piles.
A theoretical cost effectiveness analysis based on a hypothetical model
plant was used to select control options for a field study. Based on this
analysis, four emission control options were selected. Emissions from the
transfer of baghouse fines could be reduced by bagging or slurrying the fines
at the plant before dumping. Active pile emissions could be reduced by use
of a chemical stabilizer. Inactive pile emissions could be reduced by
application of a soil-vegetative cover. Application of bagging is estimated
to reduce the emissions by 100% at an annual cost of $10,500* while slurrying
the fine waste would reduce emissions by 85% at an annual cost of $4,100.
The use of a chemical stabilizer on the active waste pile is estimated to
reduce the emissions by 80% at an annual cost of $3,970; while a soil-
vegetative cover is estimated to reduce emissions by 90% at an annual cost of
$3,380. The costs estimated apply only to the defined model plant which is,
however, regarded as typical for the industry.
Field tests conducted at the Johns-Manville asbestos cement pipe plant
at Denison, Texas indicated that asbestos could be detected in the ambient
air surrounding the plant for distances in excess of 10 km. The striking
feature of the ambient air asbestos levels was the fact that they were found
both upwind and downwind of the plant in equal concentrations. The reason
for this effect is not known; it is theorized that the concentration levels
result from re-entrainment.
It is believed that this finding is of considerable importance because
of the possible adverse health effects which might be associated with the
asbestos levels in the ambient air. Recent studies reported in the
literature have indicated an association between mesothelioma, an asbestos
induced cancer, and the presence of an asbestos manufacturing plant with
people dwelling nearby.
Emission testing of the waste fines dumping operation confirmed it to
be a significant source of asbestos emissions. Application of the emission
control practices of bagging and slurrying the fine waste substantiated the
estimated reduction in the emissions. Crushing and leveling tests were
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conducted and these activities were found to be significant emissions sources
at the time of operation. It was calculated by atomic absorption analysis
that asbestos was emitted at the level of 14,500 to 89,000 yg per second,
depending on the meteorological conditions, from crushing activities; while
leveling of the fines gave asbestos emissions of 48,000 yg per second for
old fines and 200,000 yg per second for fresh fines.
Atomic absorption analysis was used to supplement optical and electron
microscope data. Its use is restricted to locations where there is a known
source of asbestos and where the background does not interfere with the
sensitivity. Under suitable conditions, it can give more sensitivity than
microscope data at a considerable saving in time and cost. It cannot give
any direct information on the numbers of fibers observed.
Small scale test piles of asbestos waste material were constructed and
stabilized against erosion by a chemical stabilizer and a soil-vegetative
cover. Emission testing from the piles proved to be inconclusive. This was
because the emissions from the test piles were extremely low as a result of
the stabilizing covers and their relatively small sizes (10 m diameter).
In addition, the background asbestos levels, even in a position well removed
from the main plant, were found to be clearly measurable. Soil mechanics
engineering tests applied to the piles indicated that both the chemical
stabilizer and the soil-vegetation effectively stabilized the test piles
in terms of structural rigidity. A vegetative growth with a coverage well
in excess of the 70% required as an effective surface stabilizer was
established on the test pile in spite of the highly alkaline nature of the
waste. While emission tests would have been desirable, it is concluded that
a highly stable 30 cm layer of soil would effectively preclude the emission
of asbestos from the covered waste.
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SECTION 3
RECOMMENDATIONS
This study has shown that asbestos cement waste dumps are a significant
source of ambient air asbestos. Clinical and epidemiological observations
have clearly demonstrated the association between asbestos exposure and
pulmonary fibrosis, carcinoma of the lung, and mesothelioma; and other adverse
health effects are suspected. While exact quantification between asbestos
exposure levels and adverse health effects has not yet been established, it
is recommended that emission control procedures be applied to asbestos waste
disposal operations to mitigate this source of asbestos emissions.
Four primary waste dump sources of emissions have been identified.
Baghouse waste fines can be bagged or slurried to virtually eliminate fugitive
emissions. Crushing of pipe without the presence of asbestos fines would be a
relatively minor emission source. Active sites in the absence of fine
material would also form a low level source. Until fines are no longer dumped
it.is recommended that active sites containing pipe and fines waste be sprayed
on a monthly basis with a chemical stabilizer. Long-term permanent covering
of all inactive piles is recommended using a soil-vegetative cover. It is
recommended that the depth of the soil cover should not be quoted unless
specifications are also given for the soil and the local meteorological
conditions.
Asbestos was found in the ambient air for a considerable distance
surrounding the asbestos cement pipe plant. Because of the health hazards
associated with asbestos it is recommended that further studies be initiated
to:
1. Obtain more samples under different meteorological conditions to
more precisely determine the source and the dispersion of asbestos
from the source.
2, Develop an understanding of why the asbestos was found upwind of the
plant as well as downwind in the ambient air.
3. Obtain predictive models giving population/exposure levels for
plants located in high population density areas.
A large number of chemical stabilization agents with great potential for
emission control have become available in recent years. Information is
needed on the comparative effectiveness of these new compounds, particularly
with respect to their emission control capabilities. A search of the
literature revealed only sparse information on their effectiveness for soil
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stabilization and zero information on emission control. Since approximately
50 stabilizers are available, a laboratory screening study followed by wind-
tunnel emission testing of selected material is indicated.
This study was directed at the asbestos cement waste disposal problem
where emissions are of special concern because of their adverse health
association. However, the approach to the problem using cost effectiveness
estimations as a screening step, and the generalized conclusions reached,
will be a value to many industries concerned with the problem of fugitive
emissions.
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SECTION 4
IDENTIFICATION OF EMISSION CONTROL OPTIONS
Three separate technological approaches may be utilized to mitigate the
emissions from the waste materials of the asbestos cement products industry.
The first two methods eliminate the problem at source by (a) reusing the
material in the product stream and (b) altering the waste asbestos to an
innocuous non-asbestos form. The third approach is to apply dust control and
stabilization technologies to the waste material that has been dumped onto
waste piles.
In spite of intensive efforts to reuse or to alter the form of asbestos
cement waste, no economically viable process has yet been developed. Common
practice in the industry at this time is to dump the material onto waste
piles. Frequently the dumping is performed without the application of
emission control technologies. In this section, the reuse and alteration of
asbestos cement waste products is briefly reviewed. The asbestos dust
emission control options which may be applied to waste dumping operations are
then reviewed in detail. In Table 1, the control technologies which are
reviewed in this section of the report have been listed.
WASTE REUSE
Waste reuse, when it is feasible, is the most satisfactory manner of
dealing with the waste products. Unfortunately, only a limited quantity of
the material may be recycled into the process stream. This is because the
curing of asbestos cement products is a chemical recyrstallization process
which cannot easily be reversed. Thus, once the curing is effected the
recycled material would have little more effect than an inert filler. The
use of such a filler would lead to weaknesses in the product which,
particularly in the case of asbestos cement pipe, must be capable of with-
standing stringent quality control tests. Further, much of the waste is in
the form of large broken fragments or aggregates. In order to use this
material it would first have to be broken down or ground into fine powder
form. This step is regarded as totally uneconomic.
Asbestos cement tile and other similar low strength forms of this
product could form a ready market for the finely divided waste. The cost
would be essentially that of crushing, bagging, and transporting less the
cost for dumping.
The National Concrete Masonry Association estimates that 90% of the
blocks produced by its members is to ASTM C-90 specifications. Tests have
been conducted at Johns-Manville indicating the likelihood of asbestos
8
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TABLE 1. ASBESTOS CEMENT WASTE EMISSION
CONTROL OPTIONS
A. Waste Reuse
1. Recycle to plant
2. Other economic products and uses
B. Waste Alteration
1. Chemical alteration
2. Thermal decomposition
C. Waste Dumping
1. Transfer operations control options
a. enclosure for emission control
b. fines suppression of emission
slurry
granulate
bag
wet
c. aggregates suppression of emission
crush
bag
wet
2. Waste dump control options
a. active pile control during transport,
dumping, crushing, and*leveling
b. inactive pile control
chemical stabilization
physical stabilization
physical covering
vegetative covering
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cement waste containing blocks would meet the compressive strength require-
ments of this specification.
Steam-cured bricks have been made from asbestos tailings fines that met
ASTM Specification C73-67 for grade SW and MW brick.2 Manufacturing costs
have been analyzed and have been found to be competitive with the commercial
products. Up to the present time, asbestos waste has not been used
commercially to produce these bricks.
New ways to minimize the waste as well as new ways to feed back the
waste into the manufacturing process to produce profit-making products is a
matter of considerable concern and innovative effort by each manufacturer in
the asbestos cement industry. At the present time, it is the expressed
conclusion of representative members of this industry, in which various
options for waste reuse have been attempted, that none of these reuse options
are economic.
WASTE ALTERATION
Over 95% of the asbestos used in this country is chrysotile asbestos.
Chrysotile has a cylindrical structure with magnesia on the outer surface and
silica on the inner surface. An acid leach could be used to remove the
magnesia and leave a cylindrical residue of silica. It would be useful to
effect a prior separation of the asbestos from the cement waste to get
efficient use of the acid.
Many hydrated magnesium silicates can act as cements if they are first
decomposed by heating in air.3 Thus, chrysotile asbestos waste may be
converted to fosterite, a non-asbestos serpentine mineral, by heating to
700ฐ-900ฐC. This might be used as a cement material for making steam cured
asbestos cement products. Studies would be necessary to determine the
conversion time factor to ensure that all of the asbestos was converted to
fosterite. A further problem is that it would have to be established that
fosterite was not itself a harmful material.
While both thermal and chemical decomposition are possible, they are not
economically viable.
WASTE DUMPING
Waste is dumped only when no further utilization of the waste material
is economic. Figure 1 shows a flow diagram of the accumulated waste and
follows it to its final disposition in a present day operation. Fines are
collected from baghouse filters and aggregates are accumulated from breakage,
rejects, cuttings, and drillings. The wastes are recycled when the product
specification permits. Otherwise, they are dumped and leveled, creating
visible emissions at the same time, and eventually covered with earth.
The emission control options outlined in Table 1 have been placed into a
process diagram for fines in Figure 2 and a corresponding diagram for
aggregates in Figure 3. Efficient emission control requires a separation of
10
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Waste FINES from
Collectors
Accumulate
Trans-port
Dump, Active Pile
Segregate
Small Aggregates
Crush to
Dlam. <0.5cm
Large Aggregates
Waste AGGREGATES
Accumulate
Transport
Dump, Active Pile
Crush and Level
Inactive
Pile
Figure 1. Asbestos waste disposal without emissions controls.
11
-------
Waste FINES from Collectors
Inactive Pile,
Combined with Aggregate
Recycle
for
Reuse
Soil Cover
with
Revegetation
In-Pl.ant Treatment
Disposal Site Treatment
Options
Figure 2. Asbestos waste disposal process treatment options for fines.
12
-------
Soil Cover
and
Revegetation
In-Plant Treatment
Disposal Site
Treatment Options
Figure 3. Asbestos waste disposal process treatment options for aggregates.
-------
fines from aggregates so that they can each undergo separate waste treatment
optimized for control of their emissions.
Waste emissions have been identified with four basic sources. Besides
the daily visible emissions created during dumping and during the subsequent
once a month crushing and leveling operations, low level emissions continue
to be released from exposed active and inactive dumps due to wind entrainment
of loosened surface particles and erosion of aggregates by weathering.
In Plant Options
Short term and moderate term mitigations must be considered, as well as
permanent disposal solutions. There is no single, all-purpose option to take
care of all waste dump emission control problems, but a balanced use of a
number of limited methods is required to achieve overall control of the waste
asbestos emissions.
Control is difficult once emissions are created. Control should,
therefore, begin in the plant as the waste is accumulated. Plant control
processes which are being considered are:
Crushing and sizing all waste
Wetting bulk waste before particulate emissions are created
Slurrying of fines and piping them to a settling basin
Bagging waste in sealed containers which could be stored for reuse
or dumped and covered without further treatment
Granulation of fines
Foaming of waste accumulations to prevent air entrainment and escape
of particulates
By performing the crushing in the emission controlled environment of the
plant, a great deal of the emissions released during the leveling operation
can be eliminated. If the leveling itself is combined with the act of
dumping, then emissions from that process can be very much reduced. Jaw
crushers can accept large aggregates and are suitable for this purpose.1*
Once the coarse, large aggregates have been broken down, the fines can
be separated out and treated. The fines can be wetted, granulated, or bagged
and accumulated for dumping. The wetting could be performed with or without
a stabilizer or a wetting agent.
. A number of size enlargement methods are readily available for
aggregation of the fines. Those which might be applied here are shown in
Table 2. Pressure compaction in a roll press is an attractive method for
aggregation. Large quantities of aggregates at low cost are claimed. The raw
material is compacted as it is squeezed into the gap between two rolls
rotating at different speeds.
14
-------
TABLE 2. SOME SIZE ENLARGEMENT METHODS AND APPLICATIONS1
Method
Equipment
Applications
Pressure
compaction
Roll type press
Agglomeration
by tumbling
Pellet Mill
Screw Extruder
Inclined pan or
disk, rotary
drum agglomera-
tor
Sintering and Traveling grate,
heat hardening rotary kiln
Fluidized bed
processes
Fluidized bed
Clay type minerals,
organic compounds, ores,
charcoal, lime,
phosphate rock
Clays, carbon, fertilizers,
animal feed
Bauxite, plastics, clays
Fertilizers, iron ore,
mineral and clay products,
finely divided solid
waste products
Ore, minerals, cement
clinkers, solid waste
products
Granulations for pharma-
ceutical tableting, liquid
radioactive waste
15
-------
The fines can also be formed into an aqueous slurry and piped to a
settling basin. The basin could eventually be drained and covered for long
term emission control. However, care should be taken to avoid causing a
water pollution problem.
In the operational setup of options shown in Figures 2 and 3, the waste
alteration processes are treated as an integral part of the waste treatment
flow diagram.
Control of Active Piles
Those sections of a dump where material is still being dumped have been
considered as "active sites". Correspondingly, "inactive sites" refer to
those sections of the dump to which new wastes are not added and where
vehicular traffic does not disturb the surface.
When an accumulation of waste is being dumped and leveled at an active
site, a very high emission concentration is created when positive measures
are not taken to control the emissions. The potential emission problems
occurring during this activity depends on the effectiveness of the control
measures being used in the in-plant waste control operations. If the waste
consists only of smaller aggregates which have been well wetted in-plant,
perhaps no control may be required except to prevent stirring up what is
already on the dump. Foaming the surface of the dump might be effective in
preventing this stirring up action. This could be more effective than
spraying since a deep penetration of the wetting action would be required to
offer the same degree of emission suppression as a thick layer of foam.
A new foam successful in suppressing mine dusts is available for this option.6
During the time between the dumping and leveling operations, the
emissions from the active pile are similar to those from the inactive pile.
Chemical treatment of the surface of the dump with a stabilizing agent which
decreases saltation particles could be effective for control of emissions
from an active pile and from an inactive pile which is not yet covered.
Chemical Stabilization of Asbestos Waste
In order to apply state of the art chemical methods for asbestos waste
stabilization, the possibilities of adapting soil stabilization techniques
are attractive. A brief review of the technical information on this subject
was made. Then commercial sources of material supplies were contacted and
price information for these materials was obtained.
ป
Quaternary ammonium salts of long-chain fatty acids have been known to
improve the stability of soils for many years, as demonstrated in several
studies at Iowa State University.7'8'9 The mechanism of soil stabilization
by these compounds is generally considered in terms of reduced water
adsorption and improved orientation of water dipoles between soil particles
Dry soils form hard crusts and compact clusters because the residual moisture
is present in oriented thin dipolar films that link the soil particles and
hold them together. When the soil is wetted during a rainfall, the inter-
particle film layer increases considerably in thickness and dipole bridging
16
-------
effects are greatly diminished. The resulting loss in soil strength can be
alleviated by deposition of cationic organic compounds on the surface of soil
particles, as these compounds will interact (electrostatically) with the
negatively charged soil particles, imparting to them hydrophobic properties
and thereby lessening their affinity for water. The reduced susceptibility
of the soil for water adsorption is responsible for maintaining the strength
of treated soil in aqueous environments. However, over treatment can render
the soil so hydrophobic as to interfere with the capability of water dipoles
to link the individual soil particles in a cohesive structure. It is
apparent that the amount of treating compound must be controlled to ensure
binding efficiency for the stabilizing agent.
The mechanism of soil stabilization by nonionic high molecular-weight
compounds is different from that of ionic treating agents since the
flocculation tendency of charged compounds is here replaced by the purely
adhesive action of long-chain polymers. This action, reflected in the
capability of some polymers to form inter-laminar complexes and vertical
bridges at edge faces of silicate crystals is considered responsible for the
effectiveness of polymers in soil stabilization.10 A number of other high
molecular-weight compounds that are capable of forming hydrogen bonds with
exposed oxygen and hydroxyl groups have been found to improve the stability
of soils by virtue of their adhesive properties.
Although a direct comparison between the stabilizing effectiveness of
organic chemicals in the treatment of soil and asbestos waste is difficult,
the silicate nature of serpentine (chrysotile) and amphibole (tremolite,
actinolite) asbestos should present a number of anchoring sites for the
attachment and adhesive bonding of polymer stabilizers. Soil and asbestos
might not respond similarly to treatment with charged organic chemicals since
chrysotile, unlike soil particles, carries a positive surface charge, as
determined by its zeta potential (+30 mv). Possible benefits derived from the
application of cationic soil stabilizers to asbestos waste would then result
after stabilization by the entrapment of the asbestos fibers in the asbestos-
occluding soil particles. Such entrapment, although not involving direct
treatment, could prove effective in the control of asbestos emissions from
waste dumps.
Candidate Materials
A survey of potential chemical treatments was made to find materials
which have been used as stabilizers of soil and fibrous particulates similar
to the present waste.
A number of polymers have been found effective in the stabilization of
soil. These polymers include polyvinyl alcohol (PVA), polyacrylic acid (PAA),
a copolymer of vinyl acetate and maleic acid (VAMA),u sodium alginate and
polysaccharides,10 unsaturated polyesters and epoxide resins, and
carbamideformaldehyde resins.13 The stabilization of soils with PVA was
found effective in surface applications at a 0.05% loading level11* with no
adverse effects on the emergence rate of wheat.15 On the other hand,
bituminous soil treatments, which are known to maintain their effectiveness
for several years, have inhibited the growth of soil microbial populations
17
-------
and reduced enzyme activity.16 These relationships might be important in
those instances where waste disposal areas would eventually be considered for
rehabilitation and agricultural uses.
From a review of the published literature and conversations with
representatives of industry, information was obtained on the applicability of
several chemicals and proprietary treating agents for the stabilization of
asbestos waste. These chemicals included charge-carrying organic compounds,
polymeric binders, and trademarked products of not well-defined composition.
A list of these chemicals with price quotation on a unit mass basis as
available is presented in Table 3.
Control of Inactive Piles
The chemical treatments which could be used to stabilize active piles
could also be used to stabilize inactive ones. However, the chemical
treatments can only offer short to moderate term stabilization. Long term
emission control can be obtained only by either chemical alteration of the
asbestos waste itself or by a permanent cover on the waste dump.
A bare soil cover, alone, is not always stable and, given unfavorable
conditions, could blow away. A soil cover with a stable vegetative growth is
more esthetically pleasing and would offer the surest, most lasting emission
control over an inactive dump.
Agronomists have been studying the revegetation of mine waste dumps and
the over burden from surface coal mines,17'B'ฎ Dr. W. A. Berg,17 consultant
agronomist to this program, has studied the vegetative stabilization of
wastes from a number of different metal ore mill tailings and spoils from
open pit and strip mines.
The use of stabilizers of a resinous adhesive type has been reported by
Dean and Haven of the Bureau of Mines.19 These stabilizers have found success
in helping promote revegetative growth directly on fine mine tailings. The
stabilizer is water soluble and could be useful for stabilizing the vegetative
soil cover during germination and early growth.
The methods used to get vegetative cover was similar for all these
workers. Although in some cases planting directly on the waste was successful,
generally a layer of earth was laid down on the dump. Then a water slurry of
seeds, fertilizer, and mulch was sprayed on the surface, giving a rapid
uniform distribution of all the necessary materials at one time.
In asbestos cement waste, the cement is quite basic and requires a soil
cover to get healthy plant growth'. On the other hand, soils generally lack
anion exchange capacity. Plants require a number of minerals from the soil
which occur as anions. These include phosphates, nitrates, sulfates, borates,
and molybdates. The asbestos could provide the stable anion adsorption sites'
lacking in the clay of the soil which could be used after sufficient
neutrality has penetrated the waste.
18
-------
TABLE 3. CHEMICAL STABILIZERS
Product
Chemical Identification
Supplier
Cost,
Dollars/kg
Amine D Acetate, SOS
Polyrad 1110A
Vinsol Emulsion
Defloc 50
Abitol
Paracol emulsion
Piccolyte Dipentene
Reten 421
Neuphor 100
Kymene 557
Landlock XA2440
Stabilized abietyl
amine
High molecular-weight
amine ethylene oxide
adducts
Water emulsion of
aliphatic resin
Cationic polymer
Hydroabietyl alcohol
Wax-rosin emulsion
adhesive
resin
Anionic acrylic polymer
Anionic emulsion
Cationic polyamide-
epichlor-hydrin resin
Adhesive binder
Hercules, Inc.,
Hattiesburg, Miss.
Hercules, Inc.,
Hattiesburg, Miss.
Hercules, Inc.,
Kalamazoo, Mich.
Hercules, Inc.,
Milwaukee, Wise.
Hercules, Inc.,
Burlington, N.J.
Hercules, Inc.
Hercules, Inc.
Hercules, Inc.,
Hopewell, Va.
Hercules, Inc.,
Milwaukee, Wise.
Hercules, Inc.
3M Co., St. Paul, Minn.
1.38
1.72
0.28
0.37
1.85
3.09
0.51
-------
TABLE 3. (Continued)
Product
Chemical Identification
Supplier
Cost,
Dollars/kg
ro
o
Latex M145 or M166 Latex binder
Elvanol
Vinylac
ARQUAD 2HT
ARQUAD 2S
Ethomeen T/12
Crude Amine
Krilium CRD-186
Sodium alginate
Polyacrylic acid
Superfloc 16
Polyvinyl alcohol
Polyvinyl acetate,
tackified dispersion
Quaternary ammonium
compound
Quaternary ammonium
compound
Tertiary aliphatic
amine
Amine compound,
unpurified
Vinyl acetate/maleic
acid
Sodium alginate
Polyacrylic acid amine
Flocculant
Dowell Div., Dow Chem-
ical Co., Tulsa, Okla. 0.53/&
E.I. Du Pont de
Nemours & Co.
Borden Chemical Co.
Armak Chemicals Co.
Armak Chemicals Co.
Armak Chemicals Co.
Armak Chemicals Co.
1.12
2.40
1.60
0.75
Monsanto Chemical Co.,
St. Louis, Mo.
Rolakem Co.,
Teaneck, N.J. 4.41
Rohm & Haas Co.,
Philadelphia, Pa.
American Cyanamid Co.,
St. Louis, Mo.
-------
TABLE 3. (Continued)
tsj
Product
Coherex
Rezosol 541 IB
Dextran
Chemical Identification
Resinous binder
Cationic resin emulsion
Dextran
Supplier
Witco Chemical Co.,
Hammond , Ind .
E . F . Houghton Co . ,
Philadelphia, Pa.
Howard Hall Co . ,
Cos Cob, Conn.
Cost,
Dollars/kg
0.095 A
0.065/&
8.82
-------
SECTION 5
ANALYSIS OF EMISSION CONTROL
EMISSION CONTROL COST EFFECTIVENESS ESTIMATES
In Section 4 of this report, the control techniques which might be
applied to the task of reducing the emissions from asbestos cement waste
dumping operations are discussed. In this section, the cost effectiveness
of these techniques are estimated from the estimate of the cost of application
of each technique and from the estimated reduction in the emissions brought
about by that technique.
In order to estimate the cost and emission reduction factors, a hypo-
thetical typical plant has been developed as a model. The plant is based on
the Johns-Manville plant at Denison, Texas, as discussed in Section 3.
The estimation of fugitive emissions from a site is a difficult procedure
and yet such estimates must be developed in order to provide a logical basis
for the application of controls in the field testing program. The emission
rates estimated in this study were found to be quite reasonable and realistic
when compared to those obtained subsequently in the field study. They have
been left unchanged in this section in order to present the methodology of
control technology selection based on environmental engineering judgement and
estimation techniques.
MODEL PLANT DETAILS
A model plant which manufactures asbestos-cement pipe is considered to
be located in an urban area in the southwestern part of the United State's.
No effort is currently being used to mitigate the emissions from the waste
dumping operations.
There are two types of asbestos-containing waste material originating in
the plant which are taken to the dump:
Reject asbestos pipe and scrap 13.2 metric tons per day
Fines from the baghouse 0.9 metric tons per day
The daily production of asbestos cement pipe is about 200 metric tons.
Production continues for six days per week for 50 weeks per year. The
composition of the waste is approximately:
22
-------
Cured Portland Cement 45%
Quartz silica 30%
Asbestos 25%
It is assumed to have a density of 1,760 kg/m3 (100 pounds/ft3).
The emissions from the dump area are assumed to have the same composition
as the dumped waste (25% by weight of asbestos) . It is further assumed that
every nanogram of asbestos releases into the atmosphere 1,000 asbestos fibers
as determined by electron microscopy.
Emissions from the dump area are considered to arise from four basic
sources:
Daily dumping of the waste onto the active dump area
Crushing and leveling of the reject pipe by a bulldozer once a month
Weathering of the active pile
Weathering of the inactive pile
The active part of the dump is where waste material is currently being
dumped. It is subject to disturbance by vehicular traffic and bulldozer
activity, it has an assumed area of 810 m2 (0.2 acres). At the end of one
year, it is 3 meters deep and a new active dump area will be started. The
southwestern area location means that the area will be dry (less than 1 m
of rain annually) and, thus, the emissions will be in a high category.
ESTIMATION OF EMISSION FACTORS
Emissions from the Active Dump Site
Based upon the 14.1 metric tons/day of waste material generated,
2,400 m3/year must be disposed. The active dump site at this plant is 810 m2.
At the end of one year, the pile will be 3 m deep, at which time a new dump
area will be started.
This plant is located in that part of the southwest which receives less
than 1 meter of rain annually. Thus, the surface of the waste pile is
extremely dry most of the year and favors relatively high emission rates.
In a study by PEDCo,20'23 particulate emissions from tailings piles were
developed for various climatic conditions. Because of the high moisture
evaporation rate and the large number of fine particles contained in the
asbestos pile, the highest listed emission rate was used for this waste
material, 3,583 metric tons/km2/yr, of which 25%, or 0.7 metric tons/yr,
would be asbestos. Thus, the average emission rate from the active pile
would be:
23
-------
0.09 kg per hour
9
or 90 x 10 nanograms per hour
12
or 90 x 10 nanograms per hour*
Emissions from the Crushing of Rejected Pipe
The waste consisting of rejected pipes and scraps amounts of 13.2 metric
tons/day at this plant. Visible emissions can be observed during the
crushing operation at the dump, indicating that this operation may be a
significant source of emissions. It was assumed that 0.01% of the rejected
material becomes airborne, of 32.5 kg/month (1.3 kg/day of operation). The
pipe is crushed for one day a month. The emission rate is averaged over the
entire year with 25% by weight of this emitted material considered to be
asbestos, yielding the following:
0.009 kg per hour
9
or 9 x 10 nanograms per hour
12
or 9 x 10 asbestos fibers per hour*
Emissions from the Inactive Pile
The emissions from the inactive pile are a function of the size of the
pile and the rate of emissions coming off the pile. It has been assumed that
the emission rate from an asbestos pile asymptotically approaches 1/5 the
emission rate of the active pile, thus, the emission rate is assumed to
rapidly approach 22.2 kg/hr/km and remains constant at 22.2 kg/hr/km once
an asbestos pile becomes inactive.
The older the asbestos facility is, the larger the inactive pile becomes
and the greater the emissions from this source. In the model plant, the
inactive pile contains five years of waste material. However, in another
five years, the emissions from the inactive pile will double. Thus, the
inactive pile must be prevented from becoming the primary emission source.
If the emissions from the inactive pile are uncontrolled, the annual
emission rate increase, proportional to the increase in pile area, will be:
0.018 kg per hour
9
or 18 x 10 nanograms per hour
12
or 18 x 10 asbestos fibers per hour*
* A conversion factor of 1,000 fibers per 1 ng was used; this is in agreement
with the literature and also with the results obtained from electron
microscope data obtained during this study, see page 80.
24
-------
Total Emissions from Asbestos Disposal Operation
The total emissions from the dump is the sum of the emissions from the
four primary sources. The total emissions for an uncontrolled dump at
several ages is shown in Table 4. The emissions from the inactive pile
can be seen to depend upon the number of years of accumulated waste. A three
fold increase in emissions occurs as the waste accumulates over a period of
twenty years. Thus, although the annual increment in the emission rate from
the inactive pile might be considered negligible, the long term effects are
cumulative and can become the dominant source of emissions.
TABLE 4. EMISSION RATES OF UNCONTROLLED INACTIVE
PILE AT SEVERAL AGES
Emission Rates, kg/hr
Emission Sources
Active Dump Site
Crushing of Reject Pipe
Dumping of Fines
Inactive Pile
TOTAL EMISSION RATE
1 yr
0.090
0.009
0.034
0.018
0.151
10 yrs
0.090
0.009
0.034 .
0.180
0.313
20 yrs
0.090
0.009
0.034
0.36Q
0.493
Annual Average Ground Level Airborne Asbestos Concentration
If one assumes the asbestos that becomes airborne will remain suspended,
then the dispersion techniques utilized for gaseous pollutants can be applied
to asbestos. Using Turner's Workbook for Atmospheric Dispersion Estimate,22
the area affected by various asbestos fiber concentrations was calculated.
The annual average concentrations were based on the following assumptions:
All asbestos emissions originated from a single ground level point
source, with an average wind speed of 2 m/sec.
An average stability class of "C", as described by Turner, was assumed.
A prevailing wind direction is assumed. For the purposes of this
study, we will assume that the people downwind of the plant will be
the only ones affected by the asbestos emissions.
25
-------
Tables 5A, B, and C were developed from isopleth diagrams for ground level
sources.22 The isopleths diagram for one year of uncontrolled pile emissions
is shown in Figure 4.
Best available data were used to estimate emission concentrations for
the hypothetical plant. The estimates of emission concentrations at the
dump are about twice as great as the concentrations estimates from measure-
ments obtained in subsequent field tests.
ESTIMATED COST OF EMISSION CONTROL OPTIONS
The sources of asbestos emissions were identified earlier in this
section as: inactive pile, active pile, fines dumping, and crushing of the
reject pipe. In the model plant, no dump emission control efforts are
currently being made. Each year, the size of the inactive pile increases,
as do the emissions from this source. Because of the effect of long-term
emissions from the inactive pile, the emission control options are limited
to the single method that eliminates this source permanently at the least
cost. Thus, in order to properly evaluate the overall costs, it will be
assumed that only one year's accumulation of inactive waste material is
included when estimating the annual control costs.
The following rate estimates were taken from the model asbestos
plant (see Table 4):
Emission Source Emission Rate, kg/hr
Active pile 0.090
Crushing of reject pipe 0.009
Fines dumping 0.034
Inactive pile 0.018
TOTAL 0.151
The capital and operating cost for various control schemes were
estimated as well as the degree of emission control achieved. Capital
investments were amortized over their estimated life assuming a 10% interest
rate. The following sections describe each control method evaluated, and a
more detailed description is presented in the Appendix. Table 6 summarizes
the results of these cost estimates.
Emission Control During the Fines Dumping Operation
In the model asbestos plant, three baghouses are used to collect the
fines. The storage bins in which fines are collected are emptied once per
day, and each one typically contains 0.3 metric tons of material with a
bulk specific density of 0.4 gm per cm^. The fines are currently transported
daily to the ^active pile by a 2.4 cu meter "load-lugger", which makes two
26
-------
TABLE 5. ASBESTOS FIBER EMISSION CONCENTRATION AS A
FUNCTION OF AFFECTED AREA
A. One Year of Uncontrolled Inactive Pile Emissions
Aฃฃ ,._j Asbestos Fiber Emission Concentration in Affected Area
Area (km^)
0.0010
0.010
0.035
0.07
0.10
1.0
6.0
10.0
No. of Fibers /m3
1.3 x 108
1.3 x 107
4.0 x 106
2.0 x 106
1.3 x 106
1.5 x 105
0.3 x 105
0.2 x 105
Nanograms/m3
1.3 x 105
1.3 x 104
4.0 x 103
2.0 x 103
1.3 x 103
1.5 x 102
0.3 x 102
0.2 x 102
Waste Pile Emission Rate of 0.151 kg/hr = 151 x 109 nanograms/hr
= 0.419 x 10ฐ nanograms/sec.
27
-------
TABLE 5. (Continued)
B. 10 Years of Uncontrolled Inactive Pile Emissions
Emissions
Affected
Area (km^)
0.0010
0.010
0.10
1.0
10.0
Asbestos Fiber Emission Concentration in Affected Area
No. of Fibers/m3
2.7 x 108
2.7 x 107
2.7 x 106
3.1 x 105
0.4 x 105
Nanograms/m3
2.7 x 105
2.7 x 104
2.7 x 103
3.1 x 102
0.4 x 102
Emission Rate
C. 20
of 0.313 kg/hr.
Years of Uncontrolled Inactive
Pile Emissions
Emissions
Affected
Area (km^)
0.001
0.010
0.10
1.0
10.0
Asbestos Fiber Emission Concentration in Affected Area
No. of Fiber s/m3
4.2 x 108
4.2 x 107
4.2 x 106
4.9 x 105
0.7 x 105
Nano grams /m3
4.2 x 105
4.2 x 104
4.2 x 103
4.9 x 102
0.7 x 102
Emission Rate of 0.493 kg/hr.
28
-------
10,000
1000 -
500
250
250
500
Figure 4. Isopleths for one year of uncontrolled
inactive pile emissions.
29
-------
TABLE 6. SUMMARY OF THE CONTROL OPTIONS
u>
o
% Reduction in Emissions From
1.
2.
3.
4.
5.
6a.
6b.
6c.
7.
8.
9.
lOa.
lOb.
11.
Control Method
Water Spray at Fines Dumping
Water & Surfactant at Fines Dumping
Agglomeration of Fines with Water
Agglomeration of Fines with Binder
Water Slurrying of Fines
Chemical Binder with Water +
0.25% Binder
Chemical Binder with Water +
0.20% Binder
Chemical Binder with Water +
0.10% Binder
Bagging of Baghouse Fines
Soil-Vegetative Control of
Inactive Pile
Water Spray on Active Pile
Chemical Stabilize Active Pile
once /week
Chemical Stabilize Active Pile
once/month
Land Filling Active Pile
once/month
Total Annual
Cost, $
2,800
3,400
10,000
13,000
4,100
5,800
5,400
5,000
10,500
3,380
3,570
8,970
3,970
8,700
Fines
Dumping
10
20
90
90
85
85
85
85
100
__
Aggregate Active
Crushing Pile
__
__
5
25
__
45
27
14
45
__
50
90
80
73
Inactive Total
Pile Emissions
2
4
23
35
19
46
35
27
22 52
90 11
30
54
48
20 46
-------
trips per day. Any costs associated with the various control schemes are
only the costs incurred above the current practice.
Fines Dumping Control by Water Spray at Dump Site
The load-lugger was modified with a water spray system that can be
operated when dumping the fines. The efficiency of water droplets for
removing fine particles from the air is very low, and typically only 10%
removal can be expected for the micron size particles.
The capital investimate is estimated at $3,700, with an expected life of
five years. The annual cost (operating + capital) for this system is
estimated at $2,800/year.
Fines Dumping Control by Water + Surfactant Spray at the Dump Site
Through the addition of a surfactant or wetting agent, the surface
tension of water can be lowered by a factor of 2 to 3. Thus, the ability
of water to cover the surfaces and to agglomerate particles will be
increased. It was assumed the surfactant doubled the collection efficiency
of the water to an overall level of 20%.
The installed cost for this system if $4,000, with an annual cost of
$3,400/year.
Fines Dumping Control Agglomeration with Water
Pelletizing machines have been successfully used for agglomerating
asbestos dust fines, utilizing 15-40% moisture. For this option, one
pelletizing disc machine was installed along with all the necessary
auxiliary equipment. Transport of the fines to the pelletizing disc was
accomplished by use of the load-lugger.
It is estimated that by pelletizing the asbestos fines, there would be
a 90% reduction in the emission from the dumping operation. In addition,
a 5% reduction in the emissions from the active pile would be achieved if
the fines are pelletized.
The capital investment for the disc pelletizer plus all auxiliary
equipment is $25,000, with an estimated life of 10 years. The annual cost
for the alternative is $10,000/year.
Fines Dumping Control Agglomeration with a Chemical Binder
Up to a ten fold increase in crushing strength of pellets can be
obtained through the use of a chemical binding agent with the pelletizer.
It was estimated that this binder would reduce the emissions from the active
pile by 25%, while the fines dumping operation would be reduced by 90%, the
same as agglomerating with water. The chemical binder adds $3,000/year to
the cost of the pelletizing operation, or a total cost of $13,000/year.
31
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Fines Dumping Control Water Slurry
By slurrying the fines prior to dumping, a significant reduction in
emissions can be realized. The present load-lugger is not suitable for
slurrying because it has no facilities for mixing the fines and water. It
was assumed that a used cement mixing truck is purchased for $10,000 and has
a useful life of five years. A reduction in emissions of 85% from the
dumping operation was assessed. The annual cost for this control method is
calculated at $4,100/year.
Fines Dumping Control Chemical Binder with Water Slurry
By using the same cement mixer truck described in the previous section
and adding a binding type chemical such as polyvinyl alcohol to the water
slurry, an even greater reduction in emissions can be achieved. Control of
the dumping emissions would be the same as that achieved with the water
slurry, 85%; however, there would be an increase in control efficiency for
the active pile emissions. The increased control efficiency of the active
pile emissions is a function of the chemical concentration. The following
reductions were estimated:
Wt. % Binder Active Pile
Added to Fines Emission Reduction
0.33 45
0.20 27
0.10 14
The capital cost is the same, $10,000, for the cement mixer truck, and
the annual cost varies with the chemical dosage:
Wt. % Binder
Added to Fines Annual Cost ($)
0.33 5,800
0.20 5,400
0.10 5,000
32
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Fines Dumping Control Bagging of Baghouse Fines
The bagging of the fines should be an extremely effective method of
controlling both emissions from the fines dumping operation and the active
pile. Polyethylene bags, 3 mils thick, with a capacity of 15 kg were
utilized in a manual operation which employed a used pick-up truck fitted
with a bag holder.
The emissions from the dumping operation were assumed to be completely
controlled if this technique were used. Half of the active pile emissions
originate from the baghouse fines and the other half from the rejected
crushed pipe and scraps. Utilizing a 10% breakage rate of the bags through
the year, the emissions from the total active pile should be reduced by 45%.
An initial capital investment of $5,000 is assessed with a useful life
of five years, and the annual cost is estimated to be $10,500/year.
Control of the Active Pile Asbestos Emissions
The active pile consists of fines from the baghouses (0.9 metric tons/
day) and crushed reject pipe and scraps (13.2 metric tons/day). The reject
pipe is crushed monthly and then placed in the active pile. Because of space
limitations, the reject pipe must be crushed to reduce the volume of waste
material.
Active Pile Emission Control by Water Spray
By keeping the active pile damp throughout the year, a 50% reduction in
emissions is possible. In order to keep the active pile damp, a 1,000 gallon
tank truck was purchased and equipped with a spray system. The capital
investment is estimated at $10,000 with a useful life of 10 years. The
annual cost is estimated at $3,570/year.
Active Pile Emission Control by Chemical Stabilization
Chemical stabilization is an effective method of controlling emissions.
The expected life of a binding agent is a function of the prevailing weather
conditions, and little data is available in this area. Using 100 gm/m2 of
polyvinyl alcohol, two different application frequencies were assumed.
Applying once per month, the emissions from the active pile were assumed to
be reduced by 80%. By increasing the application frequency to once per week,
a 90% reduction in emissions was considered possible. The capital investment
in both cases is $10,000 for a 1,000 gallon tank truck equipped with a spray
system. The annual cost varies with the application frequency:
Application Frequency Annual Cost ($/yr)
1/month $3,970
I/week $8,970
33
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Active Pile Emission Control Using Foaming Agents
Foaming agents have been successfully used to reduce the airborne dust
levels in mining operations.6 The use of foams for preventing particles from
becoming airborne from dumps has not been evaluated.
There appears to be no advantage of foaming the active pile compared to
the use of a chemical binder. In order to offer any advantage, the foam must
be long lasting (greater than a week), which is not the case. Once the foam
collapses, this method offers no advantage. Because more equipment is
needed and chemical costs are higher with a foaming unit compared to a
chemical binder, it is a more expensive approach without any increase in
efficiency.
Active Pile Emission Control by Landfilling
If the entire active pile is buried once a month right after the reject
pipe is crushed, an effective control method would be realized. A 15 cm
thick dirt cover will be used to cover each month's accumulation. Assuming
No erosion through the year, plus the one month of waste material exposed
at any given time, the overall efficiency of this approach was estimated at
about 70%. In addition, there would be a reduction in the emissions from
the inactive pile of perhaps 20%.
A bulldozer would be required for this operation, and its approximate
cost is $18,000. If a life of eight years is assumed, the annual cost is
estimated to be $8,700/year.
Control of the Inactive Pile Asbestos Emissions by Vegetative Cover
Each year, 2,400 m3 of waste material is accumulated in the waste pile.
At the end of each year, a new active dump site is started and the existing
pile becomes inactive.
The total surface area of this pile is approximately 1,400 m2. If the
top of the pile is covered with 15 cm of dirt and the sloping sides with
30 cm of dirt, approximately 350 m3 of dirt would be required.
The control method selected for the inactive pile must provide a
permanent cover. A combination vegetative-chemical stabilization approach
was assumed to be the method most likely to yield a permanent cover.
The pile is structurally unstable; thus, a small bulldozer is used to
spread the dirt. A hydroseeder applies the seeds, chemical stabilizer,
fertilizer, and water, and then hay is spread over the pile to protect the
seeds from washing out.
Because the model plant is considered to be located within a city,
excess land is at a minimum, and the dirt cover will be purchased from a
local source. The following cost estimate in Table 7 was prepared, updating
all referenced cost information to January 1975, dollars.
34
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TABLE 7. CHEMICAL-VEGETATIVE HYDROSEEDING COSTS
' (January 1975)
Item
Unit Cost
Annual
Cost ($)
Cost per
Acre ($)
Delivered Dirt
Spreading of Dirt
Seed
Fertilizer
Hydroseeder
Soil Seal
Water Truck
Labor, including
watering,
maintenance, etc.
TOTAL COST
$6/m3
$30/hr for bull-
dozer rental
$0.50/lb
$0.20/lb
$15/hr
$0.62/gal
$25/hr
$8/hr
2,100
6,000
270
20
10
60
20
100
800
3,380
840
40
20
100
50
150
1,500
8,700
35
-------
The cost of treating one acre of asbestos waste material with the system
listed above is significantly higher than "typical" reclamation costs
reported in the literature for various types of tailing piles. There are
three major reasons for this apparent discrepancy:
1. A cost of $6/m3 of delivered dirt was assumed in this study.
The cost estimates in the literature assume the dirt is available
at no cost on site.
2. A labor charge of $8/hr was utilized for this asbestos plant, as
compared to $3-4/hr utilized in the literature.
3. Reclamation of one acre or less of waste asbestos is much smaller
than most reclamation projects. Large savings (per acre) are
realized when reclaiming larger tailing piles, due to economies
of scale.
PEDCo23 estimated that a combined chemical-vegetative stabilization
control method would reduce particulate emissions by 90%. Once the vegeta-
tion becomes well established, we believe this control method will be 100%
efficient. Thus, we assumed that each inactive pile treated with the
combined chemical-vegetative method will emit 10% of the uncontrolled
emissions in the first year, and no asbestos emissions after the first year.
Control of the Emissions from the Inactive Pile
Each year the waste material from the model asbestos plant is disposed
of on the plant's property, and the size of this inactive pile grows ever
larger. Accordingly, the asbestos emissions from this pile also continue to
increase. Because the waste material has a high level of alkalinity, little
or no vegetation grows on this pile, and the emissions are not naturally
reduced. Obviously, the probability of effects on the surrounding
community increases each year with the growth in asbestos emissions from the
inactive pile.
The emission rate from the inactive pile after 20 years of accumulation
has been estimated to be 0.493 kg/hr. Thus, the inactive pile is a major
asbestos emission source and must be controlled on the assumption that a
health threat is posed by its uncontrolled presence. Table 4 gives the
relative estimated magnitudes of the various emission sources; it can be seen
from this table that inactive waste piles become the major contributor with
time arid as such must be controlled. The cost effectiveness analysis of the
control options evaluated all include the elimination of emissions from the
inactive pile source.
SELECTION OF CONTROL METHODS FOR FIELD TESTING
In Table 6, the control options, their estimated costs, and the
effectiveness in reducing the emissions from each of the four primary sources
discussed in the section have been listed. Based on the estimated cost and
efficiencies for various control options, a control scheme can be selected
for field testing. The control options have been grouped together into
36
-------
combinations which result in a reduction in overall emissions of 11% to 87%
and range in cost from $3,380 to $18,130 per annum for the hypothetical plant
considered.
The relative merits for the various schemes can be more readily seen
from the graph drawn in Figure 5 which plots the least cost control curve for
the combinations of control options listed in Table 8. The most critical
region occurs in the 60% to 80% part of the curve. Increasing the control
efficiencies beyond this point led to rapidly increasing cost, primarily
because three of the four sources must be controlled to achieve an increased
level of control.
Analysis of the costs quite clearly shows that control of the active and
inactive piles is the most cost effective control which may be applied. A
soil-vegetative cover is recommended for the long-term control of inactive
waste piles while the active pile should be stabilized using a chemical
stabilizer. It is estimated that with these two sources properly controlled,
a reduction of 58% in the total emissions would be brought about.
A significant increase in the emission control is brought about by
controlling the fines dumping operation. It is estimated that the total
emission control would increase from 58% to 78% if the fines were to be
slurried prior to dumping. A more satisfactory method of controlling the
fines may be to bag them at source in polyethylene bags. In this case, the
total emission reduction is estimated to reach 87%, but the cost increased
rapidly from $11,450 for the slurry system up to $17,850 for the bagging
system.
From these results, it was determined that the field study emission
control tests should be performed on three of the four primary sources.
Soil-vegetation covers should be tested for the inactive pile, chemical
stabilization should be tested for the active pile, and slurrying and bagging
should be tested for the fines dumping. Aggregate crushing is very difficult
to control, and is a minor contributor overall. This is because aggregate
crushing is only practiced for about 6 hours per month. For this reason,
no emission control tests were conducted on aggregate crushing.
37
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20,000
15,000
CO
cd
o
-a
i 10,000
o
o
5000
0
8.2
8+1 D
/
X
20 40 60
Percent Reduction
D8+7+101
I
I
I
i
i8+6a+10c
H-6b+10c
8+5+10b
80
100
Asbestos Emission Reduction
Figure 5. Least cost combinations of emission control options
(See Table 8 for code of control options.)
38
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TABLE 8. EMISSION CONTROL OTPIONS - LEAST COST COMBINATIONS
VO
, % Reduction in Emissions From
Total - -
Control Capital Annual Fines Aggregate
Method Invest ($) Cost ($) Dumping Crushing
8 3,380
8-1 3,700 6,180 10
8-2 4,000 6,780 20
8-5 10,000 7,480 85
8-6a 10,000 9,180 85
8-6b 10,000 8,780 85
8-6c 10,000 8,380 85
8-9 10,000 6,950
8-10b 10,000 7,350
8-5-10b 20,000 11,450 85
8-6a-10b 20,000 13,150 85
8-6b-10b 20,000 12,750 85
8-7-10b 15,000 17,850 100
Active
Pile
__
45
27
14
50
80
80
89
85
89
Inactive
Pile
100
100
100
100
100
100
100
100
100
100
100
100
100
Total
Emissions
12
14
16
31
58
47
39
42
60
79
84
82
87
Code:
1 Water spray of fines dumping
2 Water plus surfactant at fines dumping
5 Water slurrying of fines prior to dumping
6a Chemical binder (0.25%) with water slurrying
6b Chemical binder (0.20%) with water slurrying
6c Chemical binder (0.10%) with water slurrying
7 Bagging of fines
8 Soil-vegetative control of inactive piles
9 Water spray on active pile
lOb Chemical stabilize active pile once per month
-------
SECTION 6
FIELD TEST PROGRAM
PROGRAM DESIGN
A field test program was developed to evaluate the emission control
options selected on the basis of the technical and cost effectiveness
evaluation. Under the terms of the contract, only one or two options were to
be selected for the field demonstration. The options considered, evaluated,
and selected for study are shown in Table 9. Two options were selected for
studying the control of emissions from fines dumping containerization and
slurrying. Two further options were selected for the study of waste pile
stabilizing chemical binding for active piles and soil and vegetative
cover for inactive piles. No control option was applied to the crushing*
and leveling operation because although obvious high emissions were created,
they were only created for very short periods of time and thus they were
expected to make the smallest contribution overall.
Tests were conducted at the Johns-Manville asbestos cement pipe plant
located at Denison, Texas, 60 miles north of Dallas. The on-site location
offered the advantages of reasonable site security, easy haulage of waste
material, availability of soil for pile coverage, and the availability of
labor on a daily basis to maintain the piles and perform periodic tests.
Field tests were performed to obtain data on:
The asbestos background emissions
The emission control of the transfer operations at the dump
The emission control and the stability of the treated waste piles
Field tests were started in August 1975. Initially, measurements were
made to establish the background level of the asbestos emissions in the
general area. On completion of the background monitoring tests, work
commenced on the building of three small-scale asbestos cement waste piles.
Piles, each 10 m in diameter, were treated, one with a chemical binder,
a second was covered with soil and vegetated, while a third was left alone
as a control pile. The chemically treated pile is shown in Figure 6. The
soil-revegetation covered pile can be seen in Figure 7. The piles were
* A minor portion of pipe (1-5%) was crushed within the plant in an enclosed
system; this material was recycled within the manufacturing process.
40
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TABLE 9. EMISSION SOURCES AND CONTROL OPTIONS
Possible Control Options
Aggregates
Crushing
Fines and
Dumping Leveling
Active
Pile
Inactive
Pile
Granulation
Containerization
Spray wetting
Foaming
Slurrying
Chemical stabilization
Landfill operation
Soil and vegetation cover
In-plant crushing
Reuse, in-plant and others
0
0
ฉ
ฉ
/ Options considered.
0 Options selected for field test evaluation.
41
-------
Figure 6. Chemically treated pile (No. 3)
Chemical stabilizing agent diluted in
drum with water and applied on
pile with a sprinkler.
-------
BHR?^
^:
- ^
';''. ซป-ป*.
Figure 7. Soil-vegetation covered pile (No. 2)
Shown just after seeding. Straw used to
protect seeds from blowing sand and to
conserve soil moisture.
k 3
-------
completed in August 1975 and were monitored to assess their stability at
regular intervals for a period of seven months, ending in March 1976.
Once the long-term stability tests had been initiated on the small-scale
test piles, attention was directed to measuring the emissions from dumping,
crushing, and leveling operations at the active site. The reject pipe at the
dump is shown in Figure 8. Tests were conducted on the existing active site
since it was anticipated that the emission levels to be monitored would be
considerably in excess of those established as the background level at the
dump. The tests at the active dump site were conducted during September 1975.
BACKGROUND EMISSION MEASUREMENTS
It was necessary to make a site survey in the general area of the
Johns-Manville, Denison plant to establish the asbestos background emission
levels. Measurements were made using high-volume samplers fitted with
0.8 pm pore sized membrane filters. The filters were examined for asbestos
using optical and electron microscopes and also atomic absorption chemical
analysis (AA), as will be detailed later in this section. Measurements were
made both upwind and downwind of the plant using six samplers operating
simultaneously as shown in Figures 9 and 10. Sampling stations 1 through 4
were located on the premises of the plant. Station 5 was placed in Munsen
Park, about 4.8 km (3 mi) south of the plant dump. Station 6 was set up
2.0 km (1-1/4 mi) north of the dump in "Dutch" Chastain's backyard. The six
stations were run simultaneously on two consecutive days. On a separate
occasion, two more hi-vol stations were set up and simultaneous samples were
collected some distance from the plant, upwind at Grayson County Airport,
17 km SW, station 30, and downwind at Platter, Missouri, 9.6 km N, station 29.
Further sampling was undertaken using two real-time particulate
monitors the Royco light scattering particle counter Model 225 which is
responsive to particles in the 0.3 to 15 Urn size range, and a Gardner
condensation nuclei counter (CNC) which is responsive to particles in the
0.002 to 1 Urn size range. These latter two instruments do not distinguish
between asbestos particles and other particulate matter; their use was
restricted to building up information on the sources of particulates in the
plant area. Their advantage is that they have a virtually instantaneous
readout which enables- large number of samples to be taken. This is in
contrast to the high volume samples for which each single sample took one
day to collect and several days to analyze.
TRANSFER OPERATION EMISSIONS
General
Fugitive emissions from asbestos waste dumping activities and from
crushing and leveling operation were measured at the dump site. High
volume samplers with 0.8 vim membrane filters were used to collect emission
samples. A Royco light scattering particle counter was used to obtain a
real-time monitoring of the emission cloud.
44
-------
Figure 8. Reject pipe at the dump ready for crushing
with bulldozer. Previously crushed aggregates
can be seen in background.
45
-------
Hi-Vol Site No. 6,
2.1 km North of Dump
Prevailing
Wind
Johns-Manville Plant
Boundary Line
Scale, km
Hi-Vol Site No. 5
4.4 km South of
Dump
High Volume
^ Sampling Station
?zz=. Plant Dump
Figure 9. High volume sampler stations for area survey at
Johns-Manville plant, Denison, Texas.
46
-------
High volume sampler
station
LAKE TEXOMA
Corp. of Engineers
(1972)
'lant Dump
Figure 10. Location of high volume sampler stations for survey in
general area of Johns-Manville, Denison, Texas.
47
-------
High volume samplers were located at stations 21 through 28, as shown
in Figure 11. They were erected at a height of 1.5 meters, both upwind and
downwind of the source each day. Background measurements were taken with no
dump activity in order to establish the base line emission levels. It was
found that a reasonably constant, relatively low-level of emissions was
present. Samples were then taken while separate transfer activities were
carried out, such as:
Dumping of fines uncontrolled
Dumping of fines in slurry form
Dumping of fines contained in plastic bags
Crushing of waste pipes
Leveling of asbestos waste material
Emissions from Fines Dumping
Dumping of asbestos cement waste fines created a visible emission cloud.
In order to assess the effect of the control on these emissions, a series of
tests were conducted. An area of the dump was leveled and was well wetted
down. Onto this area, a 450 kg (1,000 Ib) load of asbestos cement fines was
dumped. A Royco light scattering particle counter was placed downwind from
the source and the sharp rise in the particle count rate from the background
level was monitored on a chart recorder as the dust cloud passed across the
sampling station located 10 m downwind from the dump.
A series of^tests were then made as slurries of asbestos cement fines
and water, with compositions ranging between 20% to 50% by weight of fines,
were dumped onto the waste pile which had been leveled and wetted. The
slurries were made in a concrete mixer of 0.8 m^ capacity. Slurries in the
range of 30% to 42% appeared to offer the most desirable handling properties
although all of the mixtures appeared to be very effective in controlling
the emissions.
Bagging of the asbestos cement fines as a means of controlling the
emissions was tested. Polyethylene bags with a wall thickness of 0.075 mm
(3 mil) and a capacity of 114 liters (30 gal) were filled with 14-16 kg
(30-35 Ibs) of fresh dry fines and then sealed. Thirty bags were loaded
into an open hopper car, taken to the waste pile, and dumped. The emissions
during this procedure were monitored as before, using the Royco particle
counter.
It should be noted that no attempt was made to take high volume air
samples during the fines dumping tests. This is because the dust cloud was
of very short duration (usually about 30 seconds) and thus they were not
suitable for extended period emission collection.
48
-------
\ Crushed Pipe
(old)
Crushed Pipe
(fresh)
Fines (old)
Fines (fresh)
Buried Dump
<>AXXX/
yvyvvo
//?/y
'//////
Hi-Vol Station 21 O
Bulldozer Path I | I I Il|
Road _~ , ~
Grove of Trees
Fence -X H-
Settling Pond mumi
Figure 11.
High volume sampling stations at the plant dump,
Johns-Manville, Denison, Texas.
49
-------
Emissions from Crushing of Asbestos Cement Pipe
At the plant, a bulldozer is used to crush the waste asbestos cement
pipe into a more compact form. For the purposes of the present study, an
Allis-Chalmers bulldozer (Model HD-16), having a total weight of 20.4 metric
tons, was used. The bulldozer was operated in a path perpendicular to the
direction of the wind. Within the path of the bulldozer, pipes were placed
to be broken-up in a manner which replicated the normal periodic pipe
crushing activities at the plant.
A Royco light scattering particle counter was placed downwind and
perpendicular to the path of the bulldozer. Using a chart recorder, the
emission level was monitored as the bulldozer made a pass along the path,
pushing pipe in front of its tracks with its blade and running over the pipe
to crush it.
Six high-volume air samplers fitted with 0.8 ym membrane filters were
placed in an upwind-downwind array to monitor the emissions over an extended
time period. The positions of the high-volume samplers numbers 21 through 26
and the path of the bulldozer marked as A are shown in Figure 11. The
samplers were located at distances of 30 to 100 m from the center of the path
taken by the bulldozer.
Emissions from Leveling of Asbestos Cement Waste
Leveling of the asbestos cement waste pile is achieved by using the
blade of the bulldozer as a scraper. Fine material is pushed into the voids
in the crushed pipe sections and the mixture is scraped level. In order to
measure the emissions from this operation, a series of experiments, similar
in nature to those adopted for the pipe crushing tests, were developed.
Waste material was leveled along the path marked B on Figure 11. The path
was perpendicular to the wind direction. An array of six high-volume
samplers were located at sampling positions numbers 21, 23, 24, 25, 27, and
28. A Royco particle counter was located at a distance of 45 m downwind from
the mid-point of the leveling path.
STABILIZATION OF WASTE PILES
Asbestos Bntrainment from Waste Piles
The ease with which asbestos particles might be released and emitted
into the atmosphere is closely related to properties of the waste and the
manner in which some of these properties change with time. Those effects
which contribute to the erosion of the soil by the wind are of particular
concern.
Wind erosion transports the soil in three modes, depending on particle
size: '2S
50
-------
Transport Mode Particle Diameter, mm
Suspension <0.1
Saltation 0.05 to 0.5
Surface Creep 0.5 to 1.0
Saltation is the active soil mover. Particles in the 0.05 to 0.5 mm range
are directly dislodged by the surface turbulence of the wind and undergo
active bouncing and jumping movements which dislodge other particles and
result in a cascade of soil movement. Saltation accounts for up to 75% of
the soil movement. Much of the movement of particles in the other size
ranges is eliminated by reducing the number of particles which participate
in the saltation process. The larger grains are too heavy to be directly
dislodged and their movement results primarily from saltation grain impact.
The finer particles are more tightly bound to the surface and are not readily
dislodged by the wind action alone. However, once they are emitted, they
remain suspended for long periods of time and can be transported great
distances.
From the above, it can be seen that in order to reduce the entrainment
of asbestos, it is necessary to prevent the saltation particles from freely
moving. In this study, stabilization was attempted in two ways: first, a
chemical binder was added to lock the particles together, and second, a
vegetated soil layer was used to cover the free surface of the asbestos
waste.
Construction of Test Waste Piles
Three small-scale test piles were constructed from waste asbestos cement
pipe and fines materials which would ordinarily have been deposited on the
main dump. The test piles were located on the far side of the plant from
the plant dump and on the upwind side in terms of the prevailing wind, as
shown circled in Figure 9 and enlarged in Figure 12. The piles were arranged
in such a manner that a line drawn through the piles was perpendicular to the
prevailing wind. Each pile was 10 m in diameter and each pile was separated
from its neighbor by a distance of 50 m. The nearest building of the plant
was about 150 m from the closest pile.
Initially, 38 m3 of broken pipe were depo*sited on each of the three pile
sites. Fine material in the ratio of 9:1, pipe to fine material, was then
dumped on top of the broken pipe material, giving a total of 4.6 m3 of fine
material per test pile. In the case of pile number 2, which was to be soil
covered, an additional 2.3 m3 meters of fines were dumped because the 4.6 m3
was not sufficient to fill the voids in the broken pipe pieces. A level
surface was required on this pile to enable an even soil cover to be placed
on the top surface.
51
-------
Direction of
prevailing win
ฎ Weather Station
B Hi-Vol Station
^4 Water Tap
TN Control Pile
\-S
T) Soil-vegetation Covered Pile
+~s
1) Chemically Stabilized Pile
50
100
meters
Barbed Wire Fence
| j Railroad Tracks
- Dirt Road
Figure 12. Field test piles site, Johns-Manville
plant, Denison, Texas.
52
-------
A bulldozer was used to shape and consolidate the piles. The average
height was 0.6 m and the sides were given a 4 to 1 slope. The top surface
was nearly flat with a diameter of about 5 m.
The site selected for construction of test waste piles was on a soil
fill area. The fill came from a cut within the plant area and was a mixture
dominated by somewhat sandy strata mixed with clayey surface soil. The
moderately dense vegetation on this site included black medic, perennial
vegegrass, tall fescue, weeping lovegrass, bermuda blackberries, cottonwoods,
and several species of weedy forbs which were not identified.
Chemical Stabilization of the Waste Pile
It was reported in Section 4 that a large number of chemical stabilizers
are available. From the available stabilizers, one had to be selected for
the field test. Some of the desirable characteristics of chemical
stabilizers in terms of the present study are listed in Table 10. From prior
experience at IITRI, a short list of candidate stabilizers was selected since
an exhaustive selection process was not feasible. These materials were
tested for durability by forming small cones of asbestos waste and
impregnating them with the stabilizer at various concentrations. The
impregnated cones were then dried and subjected to simulated rainfall for
various time periods. The cones were then tested for strength by measuring
the compressive load required to cause the cone to collapse. The stability
of the cones was also measured in a separate way by measuring the quantity of
organic (stabilizer) and inorganic (asbestos-cement) material leached from
the cones by the action of the simulated rainfall.
An example of the results obtained are given in Table 11. It is seen
that COHEREX (Golden Bear Division, Witco Chemical Corporation, Oildale,
California) and ELVANOL (Du Pont Chemical Company, Delaware) both performed
well. Although ELVANOL scored better than COHEREX in each of the tests,
application of COHEREX is much easier than ELVANOL and it was selected for
use in the field test for that reason. COHEREX is purchased in ready to mix
form and can be stored indefinitely. It can be easily diluted to the desired
application strength at the site just prior to use with no special equipment
or care. ELVANOL is sold as a powder which must be slurried in cold water
and then heated to about 200ฐF with constant stirring. It dissolves and
forms a stable solution at that temperature. Solution strengths of up to
25% can be prepared in this manner but stable solutions are only formed at
less than 10% concentrations. At the higher concentrations, the viscosity
of the solution is high and could interfere with easy dispersion and soaking
in of the stabilizer into the soil.
Pile 3 was treated with COHEREX in the ratio of one part of COHEREX to
four parts of water. The diluted solution was applied with an oscillating
sprinkler using a liquid pump. The distribution of water from the sprinkler
(Dial-A-Rain, Model 055A, L. R. Nelson Corp., Peoria, Illinois) was tested
with a series of open top cans. The cans were placed in line with and
perpendicular to the direction of the sprinkler oscillation. Under very low
wind conditions, a remarkably uniform coverage was obtained over an
11 m x 11 m area.
53
-------
TABLE 10. DESIRABLE STABILIZER PROPERTIES
Low application cost
Water soluble
High bondability to the particles under consideration
Long life and stability
Resistant to heat and cold
Non-phytotoxicant
Biodegradable
No water pollution problems from drainage water
Easy to mix and apply
Effective in low dilutions
-------
Ui
TABLE 11. EFFECT OF CHEMICAL TREATMENTS ON MECHANICAL PROPERTIES OF ASBESTOS WASTE
AND RETENTION OF TREATMENTS AFTER SIMULATED RAINFALL
Compressive Strength, Ib
Treatment
Water
Vinsol
Defloc
Elvanol 71-30 (PVA)
Coherex
Klucel LF
Before
Rain
4.0
3.3
7.5
9.7
11.5
2.5
After
Rain
7.0
11.0
47.5
33.5
4.0
Removal by Water Spray, mg/ Sample
Organic
18.7
30.1
4.25
24.0
110.8
Inorganic
9.2
58.5
40.6
1.1
6.5
29.16
-------
The amount of COHEREX applied was based on the coverage recommended by
Dean18 for effective stabilization of mine and mill wastes against the
ravages of both wind and rain. COHEREX concentrate was applied at the rate
of 0.45 ฃ/m2 (0.1 gal/yd2).
Vegetative Covering of the Waste Pile
Waste pile number 2 was covered with a 30 cm layer of sandy loam. The
soil was then broadcast fertilized with a locally purchased lawn fertilizer
(Vertagreem, Texas Lawn Fertilizer 10-10-5 with iron and sulfur, USS). The
soil was fertilized at the rate of 13.4 g/m2 (120 Ibs/acre) of nitrogen,
13.4 g/m2 (120 Ibs/acre) of phosphorus pentoxide, and 6.7 g/m2 (60 Ibs/acre)
of potassium oxide. The soil cover was then worked lightly with a disc to
mix in the fertilizer. A preliminary testing with the disc showed that it
could be easily controlled so that the soil surface would be penetrated no
more than 15 cm. A mixture of K-31 tall fescue, weeping lovegrass, and black
medic was then broadcast seeded at the rate of 2.25, 1.12, and 1.12 g/m2
(20, 20, and 10 Ibs/acre), respectively. This represented a mixture of
species similar to those presently growing in the area.
An oat straw mulch was then spread on the pile surface at the approxi-
mate rate of 0.45 kg/m2 (4,000 Ibs/acre). It was lightly disced to crimp the
straw into the soil to provide protection for the establishment of the
vegetative covering.
An initial application of 6.4 cm (2-1/2 in.) of water was used to
moisten the soil cover. An additional 0.85 cm (1/3 in.) of daily irrigation
was applied for a three week period to insure germination and initial
establishment. The plot water was continued twice weekly, putting on an
inch of water each time. The watering was continued until the Fall rains
began. The rain gauge on the test site was used to determine the amount of
supplemental watering required.
The plot was refertilized six weeks after initial application to make
up for leaching of nitrogen which occurred during the initial establishment
period. The seeds germinated within the first week and easily took root in
the sandy loam which by itself contained very little natural nutrients.
Waste Pile Test Schedule
A schedule of tests and measurements to be made on the three waste piles
was set-up as shown in Table 12. The tests involved the monitoring of the
weather on a local scale, measurement of the emissions by high volume
sampler, and a series of tests designed to measure the stability, or
structural integrity, of the piles.
SAMPLE COLLECTION AND ANALYSIS PROCEDURES
Collection of Emissions in the Ambient Air
Ambient air samples were collected on membrane filters with high-volume
samplers. Millipore membrane filters (Type AA) with a 0.8 um pore diameter
56
-------
TABLE 12. WASTE PILE TESTS AND MEASUREMENTS
Pile No.*
Tests and Measurements _!_ 2^ J3
A. Continuous
1. Weather station (wind speed, wind
direction, temperature)
2. Rainfall (raingage)
B. At weekly intervals
1. (Hi-vol samples) ambient air emission XXX
2. Soil surface moisture X X
3. Vegetation coverage (during first two
months) (visual estimate) X
C. At three month intervals
1. Pile surface grain analysis
(wet sieve analysis) X X
2. Consolidation and surface reduction
(settlement plate) X X
3. Penetration resistance (Proctor
penetrometer) X X
4. Density of pile surface
(Shelby tube samples) X X
5. Channeling (visual estimate) XXX
6. Soil pH (pH meter) X
7. Chemical stability treatment
(carbon analysis) X
* Pile No. 1 control pile, untreated
Pile No. 2 soil-vegetation covered pile
Pile No. 3 chemically stabilized pile
57
-------
cut to 20.3 cm x 25.4 cm with a sample collection area of 406 cm were used.
Source emissions were determined from simultaneous upwind and downwind sample
collection. For the test piles, six hi-vol stations were set up to collect
upwind and downwind particulate samples simultaneously on a weekly basis.
Each upwind station was located 40 m south of each pile and each downwind
station was located 10 m north of each pile, as shown in Figure 12.
Meteorological information was obtained continuously from a recording weather
station, MRI Model 1072, located in the vicinity of the test piles.
Particle Counters
Two particle counters with complimentary particle size detection ranges
were used in the field tests. The condensation nuclei counter (CNC, Gardner
Associates, Inc.) is a portable instrument which detects low to moderate
levels of particle concentrations in the size range between 0.0015 to 1.0 ym.
This instrument was used in making the background survey of the area.
The Royco Model 225 aerosol particle counter is a bench top instrument
which was powered by an AC generator and used as a mobile unit. Both
digital and analogue output plug-in modules are available. For the field
work, the analogue output connected to a DC recorder was preferred. The
Royco counter will measure aerosol particles of 0.3 ym diameter and larger
in concentrations of up to 3.5 x 10' particles/m3 (108 particles/ft3). The
Royco counter was selected to estimate the effectiveness of control measures
used in dumping.
Neither instrument distinguishes between fibers and other particles.
However, they both offer real time particle concentration measures and are
useful for estimating relative levels of particulates in the ambient air.
Optical Microscope Counts
A Leitz Ortholux microscope fitted with phase contrast optics at 500X
(using 40X 0.65 N.A., objective) was used for optical microscope (OM)
counting. The basis of the procedure used was that detailed by the Joint
AIHA - AGCHI Aerosol Hazards Evaluation Committee.26 Millipore filter
membranes were cleared using a 1:1:1 solution of hexane, 1,3 dichloroethane,
and p-dioxane (see Section 8-D).
Two slides were prepared from each membrane filter examined; a minimum
of 100 fields on each slide were examined. A field has a (50 x 100) ym^
area represented by the boundaries of a Porton eyepiece reticle.
Obvious non-mineral fibers, such as spores and pollens, have been
excluded from the fiber counts. Fibers are defined here as particles with
aspect ratio >; 3 to 1. The minimum fiber length counted was 1.5 ym.
Electron Microscope Analysis
A JEOL 100C electron microscope (EM) was used to examine fibers which
were shorter than 5 ym in length. The fibers collected on a membrane filter
were transferred to an EM grid. A membrane filter section was cut slightly
58
-------
larger than 3 mm in cross section from the center of each filter and placed
particle side down on a 3 mm carbon coated EM grid. The filter covered grid
was placed in a EFFA condensation washer (E.F. Fullam, Inc.) and washed
overnight with acetone vapors. The solvent gently removed the filter media
and deposited the collected fibers on the carbon film.
Fiber counts were made at 20,OOOX magnification (EM field =
0.72 x 10-4 cm2). Fiber lengths and widths were recorded for each fiber.
Random fibers in each sample were selected for crystallinity determination
and for-x-ray elemental analysis.
Calculation of Fiber Concentrations
The fiber concentration is calculated from the microscopic fiber count.
It is assumed that the field distribution of fibers follows a Poisson
distribution. The error at the 95% confidence level for a random sample
with this type of distribution would be expressed by the formula
Error = + 2^
where C is the total count for the sample examined. Based on a count of
100 fibers, then the expected error = + 2/100 or + 20 fibers. In general,
we have attempted to get OM counts from 200 fields for each sample.
The ambient air concentration is calculated from the microscope fiber
count using the following formula
Fiber Count
Fields Counted
Total Filter Area
Porton Reticle Area)
Volume of Air
Example; For an OM fiber count of 100 fibers in 200 fields using a
20.3 x 25.4 cm2 (8 in. x 10 in.) filter, operating at 0.849 m3/min (30 cfm),
collected for 2 hours
x . 100 fibers . 406 cm2 . _1 = 4>Q x 1Q4 ฑ 0>g x 1Q4 fฑbers/m3
om 200 fields 5 x 10 cm 102 m
Atomic Absorption Analysis
When its use is feasible, atomic absorption (AA) spectroscopy can be
used to compliment OM fiber counts. It can be more reliable for measuring
low asbestos emission levels than microscopic fiber counting. The subjective
element in fiber counting is not present in AA analysis. Also, by using
relatively large filter areas (100 cm2 compared to 1 cm2 for OM), the local
concentration variations of fibers on a filter are non-existent.
For fiber counting under the optical microscope, the precision is given
by 2/C, where C is the fiber count in 100 reticle fields under the micro-
scope. For a standard deviation of 10%, a count of 400 fibers/100 fields
would be required. The same degree of precision would be achieved for
59
-------
0.4 ppm asbestos using AA, a concentration equivalent to 6 fibers/100 fields.
This is based on analysis of chrysotile with an assumed average gravimetric
size of 1.0 ym diameter x 10 ym length (10:1 aspect ratio).
The sensitivity of the elemental analysis by AA was limited by the
background concentration of the element used in the analysis. The background
has two predictable sources. The acid solution used to dissolve the sample
contributed 0.1 ppm of magnesium. The Millipore Type AA filter on which the
asbestos was collected contributed an additional 0.65 ppm for 100 cm2. The
filter background concentration was proportional to the weight of the filter
sampled and serves as a lower limit to the useful sensitivity of the
analysis. The total background was 0.75 ppm. Assuming a minimum background
concentration of 0.75 ppm +0.01, a 4 yg asbestos sample can be detectable
to + 10%.
Atomic absorption (AA) analysis was used to determine the concentrations
(XAA) of asbestos collected on the membrane filters. A Perkin-Elmer
Model 360 atomic absorption spectrometer was used. Magnesium was selected
as the tracer element. The use of AA to measure the asbestos emission
concentration was feasible because the background levels of magnesium in the
area were relatively low and constant. An emission source was identified by
the difference in concentration of magnesium found in simultaneously
collected upwind and downwind ambient air samples.
The method used for sample preparation was an adaption of the one in the
EPA Methods Handbook.27 The sample was prepared for AA analysis by digestion
of a 100 cm2 filter section in nitric acid. The filter section was digested
to dryness on a sand bath in a covered beaker with three 5 ml portions of
concentrated reagent grade nitric acid. This treatment served both to
decompose the cellulosic material in the filter, as well as to dissolve the
fine mineral particulates on the filter. The final residue was dissolved in
1 ml of 50% hydrochloric acid and then diluted to a volume of 10 ml with
deionized water (2,000 ppm lanthanum is also added for control of phosphate
interference) and submitted for AA analysis.
For samples of bulk waste from the dump, a procedure described by
Perkin-Elmer was followed. These samples were treated twice with 5 ml of
a 1:1 HC1/HF solution to decompose the silicates in the cement. This was
done in plastic beakers over a hot water bath after initial digestion with
concentrated nitric acid. The final residue was redissolved in the 5%
hydrochloric acid solution containing lanthanum.
The results of the AA measurements have all been converted to concen-
trations of asbestos in the atmosphere (yg/m3). The atmospheric concentra-
tions of asbestos are calculated from the magnesium concentrations in high
volume filter samples using the following formula
' X - (CM " CAB> ' ^V ' VAA
T F A C
HV *HV AA MG
60
-------
where
XAA a concentrat:ion of asbestos fibers in the air,
CAA = concentration of magnesium in the AA analysis sample, yg/cm3
T^ = sampling time, min
FHV = sampler flow rate, m3/min
CMG = wt* fraction of magnesium in asbestos
C^-g = concentration of magnesium in the filter blank, yg/cm^
A^ = total cross section area of hi-vol filter, cm2
A.^ = area of hi-vol filter used in AA analysis, cm2
V^ = total volume of solution used in AA analysis, cm^
Source Emission Rates at the Dump
Emission rates from the waste pile were calculated from both the OM
fiber counts and AA analysis using the Binomial Continuous Plume Dispersion
Model as detailed by Turner.22 The technique permits prediction of emission
rates from a source using measured concentrations of a downwind ambient
pollutant .
A number of assumptions are made in the use of this model:
The plume spread has a Gaussian distribution in both the horizontal
and vertical planes.
The wind is constant in speed.
The emission rate is uniform.
Total reflection of the plume takes place at the earth's surface.
Diffusion in the direction of the plume travel is minimal.
Point source extrapolations can be used to estimate the source
emission rate.
For concentrations of an ambient pollutant measured at ground level from
a ground level point source with no effective plume rise, the following
equation can be used when samples are taken along the center line of the
plume
A
61
-------
where
so that
_ X(x) * ฐz ฐy
Hf
X, , * 7T 0 0
_ (x) z y
u
u
A.H
where
R = emission rate per unit area, g/sec/m^
Q = emission rate/ g/sec
A = area of source, m^
X(x) = measure(* concentration from a hi-vol sample at a distance
downwind along centerline, g/m^
02ป cr = standard deviation of plume concentration distribution
perpendicular to centerline in horizontal, 0y, and vertical,
0Z, directions at distance, x, downwind
U = velocity of wind, m/sec
Hf = hi-vol sampling time related concentration factor
Background emission rates were calculated by considering the dump to be an
area source with an initial standard deviation of 0yo equal to the width of
the area cross section. A virtual distance, Xy, was found (see Turner's
Handbook,2 Figure 3-2) which had a 0y value equal to 0yo. Then the
emission concentration at the receptor was used to calculate emission rates
from a point source at a distance of X + Xy upwind from the receptor.
The emission rate of a continuously emitting infinite line source can be
estimated from the emissions collected at a downwind receptor. For an
infinite line source which is emitting perpendicular to the wind direction,
the source emission rate is expressed as
q =
/2TT
S 0 U
z
. . exp
2
1
2
f
[Hi
az
2
62
-------
where
q = the source strength per unit source length
H = the source height
X = the emission concentration at the receptor
and the other terms are the same as for the previous equation. Due to mutual
compensation of lateral dispersion from adjacent segments, the horizontal
dispersion parameter, cry, does not appear in the equation.
For the ground level infinite line source, such as a highway, the
concentration at the receptor becomes
X a U
Z
V^TT X 0
Z
U
2
fP2
exp
/27T
f 'I
2
dP
In the field tests of crushing and leveling operations, a finite line
source approximation was used. The ground level finite line source emission
rate was estimated from the emissions collected at a ground level receptor as
q
where
Pl = VV and P2 = Y2/CJy
The wind orientation must be perpendicular to the direction of the line
source. The line source is considered to extend from Yj to Y2 where Yj < Y2.
The values for the integral are available from tabulations found in the
statistical table.
The source emission rate, Q, is proportional to the line source length
and is expressed as
Q = p q
where p is the bulldozer path length.
The emission rate can also be estimated from the measurement of particle
losses from a pile surface using the equation
Af Sf D L
R =
63
-------
where
R = the emission rate of a unit area of surface
A^ = asbestos fraction in waste
Sf = fraction of surface material lost
D = density of surface layer
L = thickness of surface layer
T = time duration of emission
Example; The effect of a 1% loss of particles in the top 1.27 cm layer of a
surface with 0.8 g/cm^ bulk density and containing 12% asbestos is calculated
when the loss takes place uniformly over a period of six months
R = (0.12) (0.01) (0.8 e/cm3) (1.27 cm) (104 cm2/m2)
1.56 x 107 sec
R = 0.8 x 10~6 g/sec/m2
64
-------
SECTION 7
FIELD TESTS RESULTS AND DISCUSSION
BACKGROUND ASBESTOS EMISSIONS
The results obtained when the high volume filter samples were examined
by both optical microscopy and atomic absorption are given in Table 13.
It can be seen that (a) the emissions on the two separate days are similar,
(b) the emissions are similar in magnitude both upwind and downwind from
the plant, and (c) the emissions are present at considerable distances from
the dump.
In Figures 13 and 14, the emission concentrations have been plotted as
a function of distance from the plant for the optical microscopy data and
the atomic absorption data, respectively. In Phase I of this study21 , some
preliminary samples taken in close proximity of several waste dumps indi-
cated a similar trend. The result is theoretically predicted, over the
long term, by application of the Climatological Dispersion Model (CMD)29 .
This model was used in Phase I and it is interesting to display here in
Figure 15 the asbestos concentrations predicted by the model. Emission
concentrations are predicted both upwind and downwind as a result of all of
the varying directions taken by the wind over the long term.
Although the concentration levels are somewhat different, there is a
remarkable similarity in the form of the sampled data and the theoretical
predictions. This result is of practical significance to the Environmental
Protection Agency and much more data should be collected in order to better
understand the dispersion of asbestos from industrial asbestos plants.
Background particle counts were measured throughout the plant area
using a condensation nuclei counter (CNC). A summary of these results is
given in Table 14. It can be seen that the particles counted near to the
scene of vehicular traffic, that is, near to the highway and in the immedi-
ate plant buildings, were far in excess of those found in ofiher areas. The
CNC is not specific for asbestos and will respond to all particles acting
as nucleation sites in the range 0.0015 ym to 1.0 ym. Since the emissions
from the vehicular activity swamped all other sources, the results could
not be further utilized in this study.
EMISSIONS FORM THE TEST PILES
High volume samples were placed 40 m upwic.d and 10 m downwind from
each of the three test piles. Samples were collected on a weekly basis.
For purposes of comparison, a selection of samples were analyzed which had
65
-------
Table 13. BACKGROUND ASBESTOS CONCENTRATION, UPWIND AND DOWNWIND OF
THE JOHNS-MANVILLE PLANT DUMP, DENISON, TEXAS; RESULTS OF OM FIBER
COUNTS AND AA ELEMENTAL ANALYSIS
Hi-vol
Station No.
Date (Filter No.
8-06-75
8-06-75
8-06-75
8-06-75
8-06-75
8-06-75
8-07-75
8-07-75
8-07-75
8-07-75
8-07-75
8-07-75
9-18-75
9-18-75
5
1
2
3
4
6
5
1
2
3
4
6
30
29
Asbestos Emissions1
Distance from XOM
) Dump, km Fibers/m3 x 10"^
4
1
0
0
0
2
4
1
0
0
0
2
17
9
.44,
.26,
.87,
.00
.55,
.06,
.44,
.26,
.87,
.00
.55,
.07,
.0 ,
.6 ,
upwind
upwind
upwind
downwind
downwind
upwind
upwind
upwind
downwind
downwind
upwind
downwind
2
3
3
3
2
1
0
1
1
5
1
1
1
1
.8
.2
.7
.0
.4
.3
.88
.51
.93
.2
.1
.04
.28
.12
XAA
ng/m3 x 10~3
1.
0.
1.
1.
1.
0.
0.
0.
1.
3.
0.
0.
0.
0.
54
87
04
21
54
77
88
88
38
02
88
80
0
0
1 XOM =
microscope fiber counts, fiber length > 5
XAA = cnrysotile asbestos concentration by Atomic Absorption Analysis
for magnesium.
66
-------
e>o
ง
e
H
B
IT)
.s
CO
QJ
Pn
id
O
tO
M
4J
a
(U
O
c
O
O
1.5 ym in length,
upwind and downwind of the plant.
67
-------
co
o
00
a
ง
o
a
o
CJ
co
co
to
01
8
3.0
2.0
1.0
0
Upwind
I
Downwind
i
20 15 10 5 0 5
Distance, km
10
15
20
Figure 14. Distribution of asbestos mass concentration
upwind and downwind of the plant.
68
-------
to
g
o
10
A
"^6
CO
0)
Upwind
Downwind
I03
o
o
CO
a.
o
o
CO
o
U
H
cd
U
H
J-l
5-
10'
20
15
10
10
15
20
Distance, Km.
Figure 15.
Asbestos concentration distribution upwind and
downwind of plant as predicted by
Climatological Dispersion Model.
69
-------
Table 14. PLANT AREA BACKGROUND PARTICLE COUNTS MEASURED BY
CONDENSATION NUCLEI COUNTER
15 3
CNC Counts x 10 , p/m
Sampling '-^
Location Date; August 9. 1975 Date; August 22. 1975
Next to Highway 260 540
In Plant Area 29 21
At Dump 11 14
Field 300 m S. of Plant 9 43
Field 300 m N. of Plant 14 25
Wind Direction NE-S E
and Speed 0-3 km/hr 1.6-3.2 km/hr
70
-------
been collected under similar meteorological conditions (that is, similar
wind speed and direction, and similar soil moisture and time periods
between precipitation and sampling). Typical results of the optical micro-
scope (OM) analysis of these filters are given in Tables 15 through 18.
It is immediately apparent from these tables that the differences
between the upwind and downwind samples are either very small or non-exis-
tent. In Figure 16, all of the upwind samples taken on given dates and all
of the downwind samples have been plotted with their mean values and stan-
dard deviations. It can be seen that the standard deviations show consid-
erable overlap. Using the null hypothesis, the averages were subjected to
the statistical "t" test to determine if a significant difference did in
fact exist.
The measure, t, for this particular application can be formulated as
follows
t =
/ n * m
/ n + m
where Xd and 3^ are the average downwind and upwind concentrations sampled
at the same time, m and n are the degrees of freedom for the upwind and
downwind sets and are each equal to one less than the number of samples, h,
in each set. S is the standard deviation of the combined set of the upwind
and downwind samples. S is calculated from
j i
Z Z (
1 1
j
z <
1
:s. -x.)2
:hj " l)
i is the number of samples in a set and j is the total number of sets.
In Table 19, the calculated t values are compared with the values of
tQ.ioป which, for normal distribution of samples, will be exceeded only
10% of the time if the samples are all from the same population. The fact
that the t values in every case are less than the tg.io values means that
the difference between the average sample concentrations, X(j and Xu are not
significant at the to.10 level.
It is concluded from these results that the emissions from the small
test piles are too low to be monitored. Three reasons why they cannot be
monitored are:
the general asbestos background level in the vicinity of the plant
is relatively high even upwind from the source
the monitoring instruments for asbestos are not sufficiently sensitive
the total emissions from the small test piles are very low
71
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Table 15. OPTICAL MICROSCOPE MEASUREMENT OF FIBER EMISSIONS
FROM STATIC ASBESTOS CEMENT WASTE TEST PILES,
SAMPLED ON AUGUST 21, 1975
-4
OM Concentration x 10 ,
fiber s/m^
Test Pile (No.)
Control (1)
Control (1)
Soil Cover with
Vegetation (2)
Soil Cover with
Vegetation (2)
Chemically
Treated (3)
Chemically
Treated (3)
Hi-vol Station
(meters)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Fiber
> 1 . 5 ym
3.6 -
3.3
5.0
4.4
(15.3)*
9.3
Length
>5 ym
0.24
0.39
0.13
0.18
(1.50)*
0.34
Wind Direction:
Wind Speed:
Hi-vol Height:
Temperature:
S-SE
15.7 km/hr (8-10 mph)
1.67 m (5.5 ft)
26.6ฐ-21.1ฐC (80ฐ-70ฐF)
Sampling Interval: ^2 hrs
Sampling Volume: M.02 m3 (3,600 ft3)
Soil Moisture:
light rain
* Hi-vol disturbed.
72
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Table 16. OPTICAL MICROSCOPE MEASUREMENT OE FIBER EMISSIONS
FROM STATIC ASBESTOS CEMENT WASTE TEST PILES,
SAMPLED ON OCTOBER 13, 1975
-4
OM Concentration x 10 ,
fibers/m3
Test Pile (No.)
Control (1)
Control (1)
Soil Cover with
Vegetation (2)
Soil Cover with
Vegetation (2)
Chemically
Treated (3)
Chemically
Treated (3)
Hi-vol Station
(meters)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Fiber
>1.5, Urn
7.1
10.7
7.7
5.2
5.5
6.4
Length
>5 ym
0.56
1.28
1.00
0.49
0.58
0.80
Wind Direction:
Wind Speed:
Hi-vol Height:
Temperature:
16 km/hr (10 mph)
1.67 m (5.5 ft)
23.3ฐ-26.6ฐC (74ฐ-80ฐF)
Sampling Interval: ^2 hrs
3 3
Sampling Volume: ^102 m (3,600 ft )
Soil Moisture:
1.7 wt
73
-------
Table 17. OPTICAL MICROSCOPE MEASUREMENT OF FIBER EMISSIONS
FROM STATIC ASBESTOS CEMENT WASTE TEST PILES,
SAMPLED ON NOVEMBER 17, 1975
-4
OM Concentration x 10 ,
o *
fibers/in-3
Mi Trt 1 C 4- Q t" -i /vn
vol. o t at ion
Test Pile (No.) (meters) >1
Control (1) Upwind (40) 4
Control (1) Downwind (10) 5
Soil Cover with
Vegetation (2) Upwind (40) (5
Soil Cover with
Vegetation (2) Downwind (10) 6
Chemically
Treated (3) Upwind (40) 4
Chemically
Treated (3) Downwind (10) 5
Wind Direction: S-SE
Wind Speed: 17.6 km/hr
Hi-vol Height: 1.67 m (5.5
Temperature: 21.1ฐC (70ฐ
Sampling Interval: ^2 hrs
3
Sampling Volume: ^102 m (3,
Soil Moisture: 2.2 wt %
Fiber Length
.5 urn
.8
.8
.4)*
.4
.3
.8
(11 mph)
ft)
F)
600 ft3)
>5 ym
0.60
0.67
(0.80)*
0.95
0.42
0.61
* Hi-vol blown over for undetermined length of time.
74
-------
Table 18. OPTICAL MICROSCOPE MEASUREMENT OF FIBER -EMISSIONS
FROM STATIC ASBESTOS CEMENT WASTE TEST PILES,
SAMPLED ON DECEMBER 11, 1975
OM Concentration x 10 ,
fibers/m^
Test Pile (No.)
Control (1)
Control (1)
Soil Cover with
Vegetation (2)
Soil Cover with
Vegetation (2)
Chemically
Treated (3)
Chemically
Treated (3)
Hi-vol Station
(meters)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Upwind (40)
Downwind (10)
Fiber
>1.5 ym
7.7
7.8
6.0
8.0
7.2
6.0
Length
>5 ym
0.56
0.96
0.20
0.74
0.37
0.75 '
Wind Direction:
Wind Speed:
Hi-vol Height:
Temperature:
S-SW
16-17.6 km/hr (10-11 mph)
1.67 m (5.5 ft)
17.8ฐ-18.9ฐC (64ฐ-66ฐF)
*
Sampling Interval: ^2 hrs
3 3
Sampling Volume: ^102 m (3,600 ft )
Soil Moisture:
2.5 wt
75
-------
vf
I
_0
CO
CD
a
o
rl
4-1
cd
M
4-1
0
0)
3
O
o
1.4
1.2
1.0
0.8
0.6
0.4
0.2
X downwind
X upwind
Aug. Sept. Oct. Nov.
Time, Months
Dec. (1975)
Figure 16. Fiber concentration vs. time for Hi-vol samples upwind and
downwind from test piles. Concentrations and standard deviations
shown from average OM counts
of fibers >5 \im in length.
76
-------
Table 19. t TEST OF AVERAGE UPWIND AND AVERAGE DOWNWIND
FIBER CONCENTRATION MEASUREMENTS
Sampling Date:
Mean Fiber_ Cone.
Upwind, X up,
fibers/m3 x 10"4:
Mean Fiber Gone.
Downwind, X down,
08/21/75 10/13/75 11/17/75 12/11/75
0.23
0.56
0.58
0.42
fibers/up x 10~4:
Degrees of Freedom:
Standard Deviation, S:
Measured
t-< , ~
0.10
0.30
8
0.44
0.22
1.86
0.85
8
0.58
0.67
1.86
0.74
11
0.55
0.49
1,80
0.79
5
0.44
0.92
2.02
* When tmeasure(j <_ to .10 the difference between X up and X down
is considered to be not significant.
77
-------
It was anticipated that the emissions from the test piles would be low
and probably too low to be monitored since they had been treated to prevent
emissions, however, some measureable emissions had been expected from the
control pile. Emission tests were made at the test piles as a confirmatory
measure, while the major effect was placed on establishing the chemical
and vegetative cover to stabilize the dump and, thus, effectively elimi-
nate emissions.
EMISSIONS FROM THE DUMP TRANSFER OPERATIONS
Emission measurements at the dump site were cencerned with the activ-
ities of waste dumping, crushing of waste pile, and leveling of the
material over the broken pipe waste. Three analytical techniques were used
to analyze the membrane filter samples which were used to collect emitted
particles via the high volume samplers. The analytical techniques were
the electron microscope, optical microscope, and atomic absorption. The
emission values obtained were used to back calculate the source term using
the atmospheric dispersion estimation methods described by Turner.22
Fine baghouse waste produced a very strong visible emission which
dissipated within the space of a few minutes, depending on the wind speed.
High volume samplers required a fairly long time period in order to collect
an adequate sample and thus, they were unsuitable for monitoring the
dumping operation. For this purpose, a Royco light scattering particle
counter, attached to a chart recorder, was used to obtain a record of the
emission concentration as the cloud passed by the monitoring position.
Dumping operations were simulated with fines both slurried and bagged
as emission control measures. The emission were monitored with the
Royco Counter and the results are sximmarized in Table 20. Both methods
appeared to offer excellent control over emissions. While the emissions
from the controlled dumping were difficult to detect, the emissions re-
leased by the uncontrolled dumping drove the chart recorder pen off scale.
A decrease in emissions of greater than 99 percent is estimated for this
activity using either of the two control.
Comparison of Results for the Electron and Optical Microscope and Atomic
Absorption
In all, 98 samples were analyzed from the 250 high volume samples
taken. Analysis using the electron microscope is very time consumimg and
expensive and, in addition, the results are known to show considerable
variation between replicates. It was thought that better data at lower
asbestos concentrations could be obtained more rapidly by analyzing the
filters by atomic absorption.
In Table 21, a comparison of the results obtained by electron and
optical microscopes and atomic absorption is displayed. The filters were
selected to demonstrate a range of activities at the dump which were of
interest to the study.
78
-------
sj
VO
Table 20. CONTROL OF EMISSIONS FROM FINES TRANSFER OPERATIONS AT THE DUMP;
MEASUREMENTS MADE WITH ROYCO PARTICLE COUNTER
Load No.
2
3
4
5
6
7
9
10
\
Control Method
slurry - mixer
slurry - mixer
dry - mixer
dry - mixer
slurry - mixer
slurry - mixer
slurry - mixer
bags - dumpster
Weight of
Waste Dumped
Wt %
47
42
100
100
42
30
35
100
Total, kg
67
67
66
66
100
70
83
450
Emissions Concentration,
(Particles/m3) x 10~1:l>0.3 ym
Background
Quiet
0.5
0.6
0.7
0.7
0.7
2.5
1.5
1.2
Gusts
1.6
0.
2.
0.
3.
steady
steady
steady
Dumping
(Above Background)
not detected
not detected
>10 (off scale)
>10 (off scale)
not detected, <0.2
not detected, <0.2
not detected, <0.2
0.4 (?)
11
dry - dumpster 100
450
1.4 steady >10 (off scale)
-------
00
o
Table 21. COMPARISON OF ELECTRON MICROSCOPE, OPTICAL MICROSCOPE, AND
ATOMIC ABSORPTION DATA FOR SAMPLES FROM FIVE LOCATIONS AT
THE JOHNS-MANVILLE PLANT, DENISON, TEXAS
Station
3
24
24
24
28
Filter
No.
7
68
50
72
,
75
Distance ^EM .^OM
Activity (m) f/m3 x 10~6 f/m3 x 10~4
Background At Dump 1.2 5.2
Background At Dump 2.1 9.3
Pipe 90 22.3 25.
Crushing
Fines 35 10.9 30
Leveling
Fines 130 10.2 29
Leveling
JAA
ng/m-3 x 10~J
3.02
6.3
31.8
46.3
18.3
-------
It can be seen that there is reasonable agreement between the three
techniques, especially with consideration for the known variability which
exists in microscopic fiber counting methods. In general, the electron
microscope concentrations are 10l to 102 greater than the optical micro-
scope concentrations. These results are in agreement with samples taken
previously at the dump site21.
A further test was made to establish the feasibility of using the
atomic absorption method, which is relatively rapid. 17 samples from a
variety of sources and locations were analyzed both by optical microscope
and atomic absorption. The results are given in Table 22. The final
column gives the ratio of the optical microscope count to the mass concen-
tration measured by atomic absorption. The data is presented graphically
in Figure 17. The close agreement of the data to the OM:AA =16:1 curve is
readily seen. Based on this information, it was deemed justified to use
atomic absorption as a measure of the asbestos emissions.
The Nature of the Emitted Fibers
Knowledge of the nature of the emitted fibers was necessary for several
reasons. First, it was necessary to know whether the fibers observed on
the filters were indeed asbestos. Second, an estimate of the average dimen-
sions of the fibers was needed in order to derive the source functions for
use in the dispersion model equation. Third, it was useful to have analy-
tical evidence to establish that the ratio of asbestos to other particles,
emitted from the waste, was in the same ratio as in the waste itself.
Identification of the fibers on the filter was performed by measuring
the electron diffraction patterns and by obtaining the x-ray chemical
spectra from individual fibers observed in the electron microscope. It can
be seen from Table 23 that the large majority of the fibers exhibited the
characteristics of chrysotile asbestos having a crystalline structure and
magnesium and silica as their main elements. From the experience of exam-
ining very large numbers of standard samples of asbestos, it is estimated
that very little error would be introduced by assuming all of the fibers to
be asbestos.
Under the electron microscope, all of the fibers can be observed from
the smallest to the largest. The dimensions, length and breadth, of all
the fibers analyzed in the above paragraph were noted. Frequency distri-
butions by length and by breadth are given in Figures 18 and 19, respec-
tively. It is seen that most fibers are less than 3 ym in length and less
than 0.3 ym in diameter. Their mean aspect ratio as calculated from the
ratios of individual fibers was found to be 10.2 (Table 24).
Asbestos containing samples from several different sources were exam-
ined for purposes of comparison. The samples included asbest cement waste
fines, fines which had been sieved through a 200 mesh (<78 ym) screen,
filter samples collected at the asbestos cement dump site, and relatively
pure, commercial grade, of chrysotile. (Plastobest 20, Johns-Manville Co.)
81
-------
Table 22. ATOMIC ABSORPTION CONCENTRATION MEASUREMENTS AND OPTICAL
MICROSCOPE FIBER COUNTS OF ASBESTOS EMISSIONS COLLECTED ON
MILLIPORE TYPE AA MEMBRANE FILTERS; AIR SAMPLES COLLECTED
ON PREMISES OF JOHNS-MANVILLE PIPE PLANT, DENISON, TEXAS
Asbestos Concentration
Activity
Sampled *
A
A
A
B
B
B
B
C
C
D
D
E
E
E
E
E
E
Filter
No.
6
7
8
44
45
46
50
64
68
72
75
113
114
116
117
118
119
Station
No.2
2
3
4
21
22
23
24
22
24
24
28
11
9
7
8
10
12
OM Count
XOM
fibers/m3 x 10~4
1.9
5.2
1.1
3,3
84.
16.
25.
6.4
9.3
30.
29.
0.57
1.00
0.56
1.27
0.48
0.80
AA Analysis
XAA
ng/rn3 x 10-3
1.38
3.02
0.88
0,57
56.
6.8
31.8
4.5
6.3
46.3
18.3
0.18
0.61
0.46
0.48
0.35
0.53
Ratio
XOM/XAA
fiber s/ng
13.8
17.2
12.5
58
15.2
24.
7.9
14.
15.
6.5
16.
32.
16.
12.
27.
14.
15.
A - area survey
B - crushing pipe at the dump
C - fugitive dust emissions at the dump
D - leveling fines at the dump
E - test piles
For maps showing sampling station locations see:
82
-------
Mass Concentration (XAA)ป ng/m
Figure 17. Comparison of fiber concentration (XOM) and chrysotile
mass concentration (XAA) for field emission samples collected in
vicinity of asbestos cement plant dump. A concentration of
15 fibers/ng shown by line.
83
-------
00
.p-
Table 23. ANALYSIS OF SELECTED INDIVIDUAL FIBERS FOR CRYSTALLINITY AND
ELEMENTAL COMPOSITION BY ELECTRON MICROSCOPY; SAMPLES COLLECTED ON
HI-VOL MEMBRANE FILTERS AT ASBESTOS CEMENT WASTE DUMP
EM
Grid No.
(Filter No.)
A-7(7)
A-2(64),
A-3(68)
B-l(50)
B-2(72)
B-3(75)
Electron
Crystalline
35
18
24
31
23
Diffraction
Non-crystalline
0
1
6
5
2
Mg-Si
7
3
2
2
4
X-Ray Analysis
Fe-Si Mg-Fe-Si
1
1
3
1 2
Others
1
1
1
-------
100
J-l
-------
100
JS
4J
00
M
-------
Table 24. COMPARISON OF FIBER ASPECT RATIOS FROM
SEVERAL DUMP EMISSION SOURCES
Station No.
(Filter No.)
3(7)
24(68)
24(50)
24(72)
20(75)
Activity
Dump Background
Dump Background
Crushing Pipe
Leveling Fines
Leveling Fines
Fiber Aspect
Mean. * Aspect
Ratio
11.5
8.3
8.0
12.6
10.6
Ratio
Standard
Deviation
2.2
2.0
2.1
2.5
2.1
AVERAGE 10.2
2.2
87
-------
The results are shown in Table 25. Some variability in measured
values resulting from different sample preparation methods have not been
completely eliminated. However, common features related to the composition
of the collected waste are clearly evident.
Comparison of the magnesium concentration of the whole fines from the
dump and dump fines <200 mesh shows that the asbestos fibers in the waste
segregate and tend to remain aggregated with the waste <200. On the other
hand, the emissions which occur are due to those particulates which are in
the fraction <200 mesh.
A comparison of the magnesium (Mg) to calcium (Ca) ratios is shown
in Table 25. The Mg/Ca ratio for the high volume samples is intermediate
between the Mg/Ca ratio for the whole fines and fines <200 mesh. This indi-
cates that the proportion of asbestos emitted is more than would be
expected from the proportion of fibers available in the emittabMe size
range. Thus, asbestos fibers appear to be more readily emitted than other
waste particles in the <200 mesh size range, and the overall proportion
of asbestos emitted is close to its concentration in the bulk waste.
Emissions from Crushing and Leveling Activities
Emissions from the crushing and leveling activities were measured
using an array of high volume samplers as described in Section 6 of this
report. All downwind samplers were operated simultaneoulsy for time
periods ranging between 5 to 40 minutes. Downwind background samples
were taken, when the bulldozer was not operating, for a period of one hour.
Upwind background samples were taken for two hours. Full conditions for
each of the experiments, numbered 11 through 19, are given in Appendix 8-E.
The asbestos emission values calculated from atomic absorption analyses
are given in Table 26 as asbestos concentrations at the point of collection.
It can be seen that the emissions downwind exceed the background by as
much as two orders of magnitude.
The source emission rate estimates shown at the bottom of Table 26
associated with each station were calculated first by assuming the wind
to be blowing in a direction which placed each receptor in line with the
source. Then a single wind direction was located to minimize differences
between emission rate estimates calculated from all stations. The area
source model was used to calculate the fugitive dust emission (downwind
background) rates in Experiment 17. The bulldozer was involved in all
other experiments and the finite line model was used to calculate source
emission rates from them.
In Experiment 13. the wind direction was varying in such a fashion
that no one direction could be justified to account for the emissions
collected at all or even most of the stations. A point source model was
used to get an initial emission rate estimate. Then a line source model
was used to obtain an aggregate emission estimate from all the hi-vol
stations. Close estimates of emission levels are difficult to make under
88
-------
Table 25. COMPARISON OF MAGNESIUM CONCENTRATION AND MAGNESIUM TO CALCIUM
RATIO FOR BULK WASTE FINES (WHOLE), WASTE FINES < 200 MESH (75 lam),
AND FOR SAMPLES COLLECTED ON HI-VOL FILTERS AT THE DUMP
Sample Description
Dump Fines, whole
Dump Fines, whole
Dump Fines, whole
Dump Fines, whole
Pile 1 Fines, whole
Pile 1 Fines, ""whole
Dump Fines < 200 mesh
Dump Fines < 200 mesh
Dump Fines < 200 mesh
Dump Fines < 200 mesh
Pile 1 Fines < 200 mesh
Hi-vol Filter No. 54
Hi-vol Filter No. 55
Hi-vol Filter No. 56
Hi-vol Filter -No. 57
Hi-vol Filter No. 58
Hi-vol Filter No. 78
AVERAGES :
Sample Magnesium
Preparation Concentration,
Method (a) Wt %
1
2
3
4
2
4
1
2
3
4
4
4
4
4
4
4
4
whole f ines
fines < 200 mesh
hi-vol sample
2.92
3.15
2.85
2.88
3,20
2.98
1.07
1.10
1.00
1.26
1.13
3.00
1.11
Concentration
Ratio,
Magnesium/ Calcium
0.151
0.150
0.183
0.191
0.040
0.060
0.078
0.088
0.081
0.118
0.074
0.090
0.108
0.169
0.059
0.093
(a) 1. 5N HNOs digestion, 30 min.
2. HC1/HF total cations in soils, Method A 4-3, Perkin-Elmer.
3. Fusion, Method GC-4R, Perkin-Elmer (modified).
4. Cone. HN03 digestion, EPA-625-26-74-003, p. 82 (modified)
89
-------
TABLE 26. ASBESTOS EMISSION CONCENTRATIONS AND EMISSION RATES FOR DUMP EMISSION SOURCES
>ฃ>
O
Asbestos Emission Concentration,
Crushing
Station No.1 Exp. 11
21 (upwind) 0.57
22 (downwind) 55.4
23 (downwind)
24 (downwind)
25 (downwind)
26 (downwind)
27 (downwind)
28 (downwind)
Wind:
Direction SE-SW
Speed, m/sec 1.3-6.6
Downwind
Sampling
Time , min 5
Source
Emission
Rate,;
yg/sec 40,600
Crushing Crushing Crushing
Exp. 12 Exp. 13 Exp. 14
0.50 0.41 0.41
23.6 31.8 39.0
4.66 26.5
31.8
19.4
22.9
SE-SW SE-SW S
1.3-6.6 1.3-6.6 1.3-6.6
30 15 40
14,500 89,000 28,000
Crushing
Exp. 15
0.41
12.5
3.7
4.1
20.2
62.4
S-SW
1.3-6.6
25
32,000
/ 3
XAA, yg/m
Background
After
Crushing
Exp. 17
1.04
4.02
1.41
5.80
3.21
11.4
S-SW
3.9-6.6
65
36,000
Leveling
Old
Fines
Exp. 18
1.04
46.3
15.7
17.0
18.3
S-SW
0-0.7
30
48,000
Leveling
Fresh
Fines
Exp. 19
2.44
4.46
233.0
9.8
34.0
59.4
SW
4.5-5.3
15
200,000
1See map, Figure 11
-------
our field conditions because they are highly dependent on the velocity
and direction of a varying wind.
STABILITY OF THE CHEMICALLY TREATED PILE
Tests Applied to the Pile
In order to judge the effectiveness of the chemical treatment for
stabilizing the test pile, a number of tests were conducted based on stan-
dard Soil Mechanics testing procedures. Where necessary, a comparison
was made of the chemically treated pile against the control pile which was
left untreated. The following tests were performed:
Distribution of the stabilizer with depth
Surface moisture analysis
Wet sieve analysis
Proctor penetrometer
Shelby tube bulk density
Settlement plate
Channeling observation
Distribution of the Stabilizer
The stabilization of waste piles with a chemical binder is essentially
a treatment of the top surface of the piles. Since the stabilizer was an
organic compound, the binder concentration was estimated quite simply by
measuring the carbon content of weighed samples of the pile. Measurements
were made on material from the top, 0.65 cm below the top, and 1.25 cm
below the top. The results as a function of time are given in Figure 20.
It can be seen from this figure that the carbon concentration at _the
top of the pile decreased steadily from a value of 12 percent carbon down
to about 7 percent after seven months. Conversely, carbon concentration
at the 0.65 cm and 1.25 cm levels increased from 1.6 percent up to 5
percent and 4 percent, respectively. It is reasonable to suppose that
rainfall is responsible for the segregation of the stabilizer. It also
appears that the stabilizer leaves the surface of the waste until a cer-
tain concentration is reached (about 5 to 6 percent from the present data)
and then remains steady thereafter. The quantity is probably some function
of the available surface and particle size.
Surface Moisture Content
Surface moisture measured in the top of the soil from the chemically
treated pile and the control pile are compared to the rainfall data in
91
-------
S3
Top Surface
A 0.65 cm below Top
1.25 cm below Top
2345
Months after Stabilizer Application
Figure 20. Concentration of the chemical stabilizer in the surface of
Pile 3 shown as a function of time.
-------
Figure 21. There appears to be no evidence to indicate that the moisture
content is affected by the presence of the chemical stabilizer.
^ soil moisture on the two piles was averaged and the average plot-
ted in Figure 22 as a function of the length of time after each rain. A
family of curves is apparent with curves associated with the greater
amount of precipitation showing the greater moisture retention. The
amount of moisture in the soil surface appears to directly related to the
amount of precipitation and the number of days which have elapsed since
the last rain.
Wet Sieve Analysis
Wet sieve analysis was utilized to measure the changes in particle
size distribution of the surface material as a function of time. Standard
sieves in range from 2 mm (10 mesh) to 37 ym (400 mesh) were used. The
results have been tabulated in Table 27. The fine material from both the
control pile and chemically treated pile has been lost from the sur-
face. This loss could be due to downward percolation, agglomeration, or
it could be due to wind erosion. Most likely all events occur, but the
low level of emissions collected on downwind high volume samples indicate
that downward percolation and agglomeration, aided by rainfall, predom-
inates.
The change appears to take place during the initial three months with
very little further change occuring subsequently. The loss seems to coin-
cide with an increase in penetration resistance as discussed below.
Penetration Resistance
The penetration resistance of the control pile and the chemically
treated pile was measured using a Proctor Penetrometer fitted with pene-
tration needles of 1.6 and 3.2 cm2 cross section. Penetration resistance
was measured at a depth of 5 cm. The results obtained as a function of
time are given in Table 28.
Penetration resistance increased with time for both the piles. No
distinction could be drawn between the control pile and chemically treated
pile. Probably reasons for the increase are the percolation of the surface
fines down to a layer where they interlock and bridge the voids; and there
is probably some slow curing of the cement over a time period.
Bulk Density Measurement
Shelby tube samplers were utilized to obtain bulk density measurements.
The Shelby tube is pressed into the pile until the depth of refusal ( the
point of strong resistance to penetration) is reached. The bulk density
is then calculated at that point.
93
-------
Table 27. WET SIEVE ANALYSIS OF THE CONTROL PILE AND CHEMICALLY TREATED PILE
Size
mm
2.0
0.3
0.15
0.105
0.074
0.044
0.037
Initial
Percent
Mean Std
74.4
30.4
18.0
14.6
12.4
9.8
8.5
Sample
Passing
. Deviation
1.0
5.0
2.5
2.8
2.9
4.1
3.2
Initial
CONTROL
Sample
PILE
After 3 Months
Tested Later
Percent
Mean Std
74
21
9
6
5
2
2
.72
.09
.37
.41
.06
.59
.44
Passing
. Deviation
0.62
1.97
1.93
2.14
1.78
1.21
1.00
CHEMICALLY TREATED
Initial Sample
Size,
imp
2.0
0.3
0.15
0.105
0.074
0.044
0.037
Percent Passing
Mean Std
86.58
41.7
28.9
24.1
19.3
12.8
11.4
. Deviation
5.5
16.3
15.8
14.7
12.6
8.3
6.6
Initial
Sample
Sample
Percent Passing
Mean
71
20
10
7
6
3
3
.5
.2
.3
.6
.1
.6
.3
Std. Deviation
6.9
5.5
3.9
3.3
3.2
2.6
2.8
After 6 Months
Sample
Percent Passing
Mean
72
20
13
10
8
6
5
.47
.93
.84
.72
.89
.46
.83
Std. Deviation
6.32
8.24
6.31
5.01
4.14
3.08
2.30
PILE
After 3 Months
Tested Later
Percent
Mean Std
88
42
30
24
20
13
12
.0
.6
.2
.9
.9
.8
.3
Passing
. Deviation
3.7
17.3
16.0
13.9
12.0
7.5
7.8
Sample
Percent Passing
Mean
73
21
13
10
8
5
5
.2
.8
.2
.3
.7
.9
.6
Std. Deviation
4.4
3.5
4.1
3.8
3.2
2.2
1.9
After 6 Months
Sample
Percent Passing
Mean
80
27
15
11
9
8
7
.76
.04
.30
.89
.70
.54
.17
Std. Deviation
2.80
4.05
2.65
2.26
1.92
2.02
1.59
-------
Table 28. PENETRATION RESISTANCE (Newtons)*
Position
(Time)
1 (Initial)
1 (3 Months)
1 (6 Months)
2 (Initial)
2 (3 Months)
2 (6 Months)
3 (Initial)
3 (3 Months)
3 (6 Months)
Averages :
Initial
3 Months
6 Months
Control
1.6 cm2
196
343**
245
267
400**
431
236
400**
369
231
383**
347
Pile
3.2 cin2
320
329**
311
436
520**
383
409
334**
498**
387
396**
396**
Chemically
Pile
1.6 cm2
205
418**
409
254
494**
449
169
525
365
209
480**
409**
Treated
3.2 cm2
311
267**
222
329
440**
538
231
302**
476**
289
338**
414**
-
*Averages of three or more measurements at each location.
**Virtually no penetration for one or more measurements.
95
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4-1
ง
O
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P.
60
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Si
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3
4-1
CO
H
0)
u
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(U
i-l
H
10
1.0
O.I
Pile 1
Construction
of test Piles
(control)
(chemically
Pile Surface Moisture, Wt,
Daily Rainfall, cm.
10.
H
tH
ซJ
1.0
0.1
Aug.
Sept.
Oct.
Nov.
Dec.
Jan.
Figure 21. Comparison of daily rainfall and surface moisture on test piles 1 and 3
over six months period.
-------
30
VO
4-1
IS
0
cd
10
(0.4) A
10
15
20
25
Interval of time after precipitation, days
Figure 22. Comparison of average surface moisture on piles 1 and 3
at different intervals of time after precipiation. Amount of
precipitation (cm) is shown in parenthesis.
-------
The results obtained are given in Table 29; as anticipated, consider-
able scatter in the results is evident. It was hoped that the stabilized
pile might show a more consistent set of values. No such inference can
be made and, hence, the results are inconclusive.
Settlement Plate Measurements
The settling plate waste levels were measured to get an indirect esti-
mate of the wind erosion surface loss from the test piles. These estimates
were based on the differences between the initial pile surface mass and the
losses with time by consolidation. The consolidation of the waste was cal-
culated from the bulk density measurements, and the volume from the settling
plate change in waste level.
The changes in settling plate waste levels over the life of the piles
are shown in Table 30. They show that the emissions collected on the high
volume samplers result from small mass changes which are not easily meas-
urable from the settling plate data.
Observation of Channeling
Observation of the surface of the piles gave no evidence that channel-
ing, as a result of rain action, was disturbing either the control pile or
the stablized pile. Apparently, good drainage is experienced through the
pile in both cases. This is a positive result since it was found that
the stabilizer might have a surface sealing effect. This would have led
to surface drainage channels and, eventually, a break-up of the pile.
Summary of Chemical Treated Pile Results
In general, it was observed that the chemically treated pile was
stabilized very effectively. The stabilizer adhered well to the waste
particles, reaching a steady level which was not removed after seven
months of weathering by heat and rain. In the surface moisture tests,
it was found that the presence of the stabilizer did not affect the
water retention in the top surface. It was feared that the stabilizer
coating might "waterproof" the treated pile and, thus, reduce the water
retention. The ability to retain water is important since moisture is
very efficient in reducing surface emission. Wet sieve analysis of the
surface indicated that fine material was lost from the surface either by
percolation or by emissions from the surface with no discernable difference
between the control piles and the treated pile.
The Soil Engineering tests, that is, penetration, bulk density,
settlement plate, and channeling observation, all indicated that the con-
trol pile and the chemically treated pile were well stabilized. The sta-
bility of the control pile is probably due to the waste material having
a residual of uncured Portland cement. As the cement slowly completes its
curing, then the pile will attain a natural degree of stabilization. The
stabilization achieved from the cement curing actually masked the effect
98
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Table 29- SHELBY TUBE BULK DENSITY (gm/cm3)
Pile Number Initial 3 Months 6 Months
1 1.30 0.886 0.626
(control pile) 1>()5 Q 8Q3 l
0 . 812
Average 1.18 0.84 0.87
0.705 0.775 0.742
1.337
Average 0.70 0.76 0.95
99
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Table 30. SETTLING PLATE MEASUREMENTS
Settling
T>1 0 show increased waste volume, values
< 0 show decreased waste volume.
100
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of small quantities of stabilizer added to the treated pile. The purpose
of the added stabilizer was to achieve only a stable crust or outer layer.
Emission testing from the piles would give the most positive infor-
mation on whether the stabilized top surface was at a lower emission rate.
Unfortunately, as reported earlier, the background interfered with the
sensitivity of the emission level testing.
STABILITY OF SOIL-VEGETATIVE COVER
General
The object of the vegetated soil cover was to provide a layer of soil
which would effectively prohibit the emission of asbestos from the waste
pile, and to stabilize the soil from erosional effects by growing a vege-
tative cover on the soil. A 70 percent foliage cover was recommended for
soil stabilization purposes by the consultant agronomist to this program,
Dr. W.A. Berg.
After reviewing the sandy loam to be used for covering the asbestos
waste, Dr. Berg recommended that a '30 cm soil cover be used. This is in
contrast to the 15 cm cover proposed by the Environmental Protection Agency
in the latest amendments to the national emission standards for asbestos.
The depth of the soil cover should be a function of the water retention
capability of the soil. Thus, for example, a deeper bed of an open struc-
tured sandy loam is required in contrast to a shallower bed of soil with a
high clay content.
A number of tests were performed to establish the vegetative cover and
to establish effectiveness of this treatment. The tests applied were:
Mineral composition
Relation between rain and vegetative cover
pH of the bed
Conductivity of the bed
Observation of vegetation
Observation of channeling
Mineral Composition
In order to establish a vegetative cover, it is essential that the
soil contain the necessary minerals to sustain plant growth. An analysis
of the soil and the waste material was made and the results are given in
Table 31. The soil was found to be extremely deficient in plant-available
phosphorus and low to moderate in potassium. The nitrate test meant little
101
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Table 31. SOIL ANALYSIS OF TEST SAMPLES
Test Material
Sandy loam, pile
soil cover
Mineral Concentration, ppm
pH N03-N P K
8.1
Fresh asbestos
cement waste fines 10.2
Buried asbestos
cement waste fines 11.1
10 1 53
24 105 1,100
19 57 630
Conductivity
(Soluble
Salts),
mmhos
0.6
1.4
0.8
102
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in terms of a disturbed site such as this; past experience indicated the
soil would be extremely nitrogen deficient.
The soil required fertilization with nitrogen, phosphorus, and potas-
sium. Fertilization with adequate rates of phosphorus and potassium would
give the necessary long-term effects. Nitrogen is subject to leaching
and nitrogen fertilization effects would usually be limited to the season
of application. Thus, nitrogen fertilizer was applied to obtain a good
initial ground cover of herbaceous species and the long-term nitrogen
would, hopefully, be supplied by the the legume, bleck medic, which was in
the seeding mix.
Relation Between Rain and Vegetative Cover
In Figure 23 are shown the percentages of vegetation coverage and the
cumulative rainfall over the six month period from August 1975 through
January 1976. Vegetation coverage on the pile during the first six weeks
was not related to rainfall since the pile was sprinkled at the rate of
5 cm of water per week during that period. The vegetation achieved a
coverage greater than' 70 percent during the first two months. When the
sprinkling was terminated, the plot was able to maintain a greater than
70 percent coverage for the rest of the six month period. The rainfall
itself was fairly constant over the whole six months, giving an average
of 0.8 cm of rain per week.
In many parts of the country, the rainfall is very limited and the
desired coverage might not be easily maintained. As a rough rule, a
minimum of 38 cm (15 in) annual rainfall would be required for a. 70 percent
coverage. However, there are many exceptions; for example, effectiveness
of rainfall in the upper midwest is much greater than in the southwest. A
30 cm annual rainfall in North Dakota might require a 51 cm rainfall in
Southern Arizona for comparable coverage.
Soil pH
Soil samples were collected for pH measurements four months after the
pile had been constructed. Samples were collected from six locations over
the pile using a Shelby tube. The pH measurements are shown in Table 32.
The values obtained may be compared to the original value of the soil,
pH = 8.1
The pH values measured on the soil varied from 7.12 on the north end
of the pile to 8.57 on a core sample from the south end of the pile. The
average pH is 8.12 for these cover soil measurements. The pH level varia-
bility across the pile suggests that some mixing-in of the waste during
pile preparation had occurred. The mixing might be largely avoided if
the waste is wetted down just before the cover soil is added on the pile.
This would prevent movement of the waste fines up into the cover as air is
rapidly expelled from the loose waste fines during cover soil addition. A
high pH is not supportive of plant growth and efforts should be taken to
minimize contamination of the cover soil by the waste.
103
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Table 32. pH MEASUREMENTS OF SANDY LOAM SOIL COVER
ON PILE AFTER FOUR MONTHS
Core
Sample Depth
Top of Soil
pH Measured.on Core Samples from Pile 2
123456
7.12
8.18 8.10 8.24 8.33
Middle of Soil 7.80 7.86 7.87 8.30
Bottom of Soil
Top of Asbestos
8.23 8.03 8.16
11.55
12.02
8.40
8.57
8.57
11.86
104
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100
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00
a
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-------
Electrical Conductivity
Soluble salts in the soil increase the osmitic potential in the soil
solution and thus, can delay or inhibit germination and reduce the plant
available water. The amount of soluble salts in the cover soil was deter-
mined by measuring the conductivity of selected soil samples. Measurements
were made on saturation extracts and compared to the accepted effect of
conductivity on plant growth which is as follows:
Electrical
Conductivity,
mmohs Effect on Plants
0-2 Salinity effects usually neglegible
2-4 Affects yield of very salt sensitive plants
4-8 Affects of salt sensitive plants
8-16 Can be tolerated by only a few special crops
>16 Unsatisfactory yield from most species
The data from the soil samples (Figure 24) indicated very little salt move-
ment upward into the cover soil from the asbestos cement waste below.
Some of the soil samples show high conductivity values compared to that of
a fresh sandy loam sample from the original cover soil; however, these
values may reflect the rather heavy fertilization of the cover soil. The
soluble salt concent in one of the asbestos cement waste samples is
relatively low. This may due to rapid leaching on this part of the waste
pile.
A comparison is made in Figure 24 between the electrical conductivity
and the pH measured for each soil sample collected. It can be seen that
the greatest pH and electrical conductivity are associated with the waste
itself, while most of the cover soil and pH value are clustered around a
pH of 8 and an electrical conductivity value of 1 mmohs.
Observations of Vegetative Cover
After seven months, the level of ground cover was found to be more
than adequate to control water and wind erosion. The intensive treatment
resulted in the production of a 95 percent ground cover of vegetation in
spite of an unusually low level of precipitation during the intervening
months. The test period included much of the expected "rainy season" of
the year. However, the test site received only 20 cm of precipitation
during the end of January. The average annual rate of rainfall for the
area over the last ten years was 106.4 cm per year.
106
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At the end of seven months, the plant growing on the top of the pile
were light green in color. This indicated a nitrogen deficiency which was
probably caused by leaching in the vicinity of the sprinkler. No fertility
problems were evident on the vegetation growth on the sides of the pile.
A hole dug on the top of the pile revealed roots in the soil extending
down to the fine asbestos-cement waste. The roots did not grow into the
waste but stopped at the soil-waste interface. Root penetration into the
asbestos-cement waste is not expected until a considerable drop in pH takes
palce. The pH will eventually drop as the lime in the cement is converted
to carbonates.
Cereal oats and weeping lovegrass dominated the vegetation on the pile.
The ground on the near-level top was covered with (about 95 percent) cereal
oats from seed introduced in the straw mulch. A fair to good stand of weep-
ing lovegrass was present among and under the oats; thus, weeping lovegrass
would provide vegetative cover once the oats matured and decayed. A few
black medic seedlings were present on the top. Only a very few tall fescue
seedlings were present on the entire pile. Tall fescue was expected to be
the major species growing on the pile. Possibly this species did not estab-
lish because it is a cool-season species and the pile was seeded in the
warmest part of the summer.
The domestic oats which produced much of the ground cover was introduced
in the straw mulch. If possible, it is preferable to use hay of the species
one desires to establish as the mulch, thus avoiding introduction of undesi-
red seed. The oats are fast-growing, annual plants which interfere with the
establishment of the perennials from the revegetation seed mix. Sucession
would be eventually transferred to the encroaching native species.
Weeping lovegrass was much more abundant on the sides of the pile than
on top. Weeping lovegrass makes much of its growth when the weather is
warm thus, most of the plant material present was dry material from last
season. Black medic was also more abundant on the sides of the pile. Black
medic was the major species on the slightly disturbed soil areas immediately
adjacent :to the plot. Black medic had substantial green growth and inspec-
tion of the roots revealed numerous small nitrogen-fixing nodules.
Observation of Channeling
Channeling was not observed to be a serious factor in either the
control pile or the soil/vegetatie test pile. The test rig used to estimate
the channeling is shown in Figures 25 and 26. It is apparent that movement
of the piles on a gross scale was not a problem during the period that the
piles were under test.
Summary of the Soil-Vegetated Cover Tests
It was demonstrated that given a sufficient depth of soil cover, a
vegetative cover could be used to stabilize asbestos waste piles. Fertilizers
are available to supplement those lacking in the soil to be used for the
cover and soil tests must be made to establish the nutrient levels in the soil.
108
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Initial
*sw
6 Months
Figure 25. Typical comparison of channeling
on a non-vegetated pile (control).
109
-------
Initial
3 Months
6 Months
Figure 26. Typical comparison of channelling
on vegetated pile (//2) .
110
-------
The high pH and electrical conductivity associated with asbestos waste
piles can be tolerated. In order that these factors do not interfere with
plant growth, it is necessary to have a sufficiently deep soil cover and to
avoid mixing of the soil with the waste fines.
The vegetation planted on the waste pile resulted in a very adequate
vegetative cover. A minimum of a 70 percent cover was considered as adequate
to stabilize the pile against erosion. In fact, a 95 percent cover was
developed.
The pile was found to have a very high stability in terms of lack of
gross surface movement, or channeling.
Ill
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SECTION 8
APPENDICES
A COST ESTIMATION OF CONTROL TECHNIQUES FOR THE DUMPING OPERATION
Fine Control Assumptions
Fine are collected from three baghouses daily. Each baghouse pro-
duces 0.3 metric tons/day or 300 kilograms/day/baghouse. Bulk
specific density of 0.4 gms/cc.
The emissions from the dumping of the asbestos fines was previously
estimated at 4.5 kg per dumping operation (once per day) averaged
over the entire year. This results in an emission rate of
9
34 x 10 nanograms/hr
or
12
34 x 10 asbestos fibers/hr
Waste asbestos from the baghouses is transported to the active pile
by 2.5 cu meter load-lugger. No asbestos emissions occur in the
plant from the loading of the load-lugger. The load-lugger makes
two trips per day.
Particle size of the emitted asbestos assumed to be 1 ym diameter
and 3 ym long.
Fine Control Water Spray at Dump Site Method #1
Based on the attached Figure, the particle collection efficiency for
particles having a diameter less than 4 ym is extremely low (20 percent).
Because we have assumed that the average particle size emitted is only 1 ym
diameter and 3 ym long, water sprays at the dump site will be ineffective.
Any form of water sprays must rely on the impingement by the spray
droplets. For maximum impingement capture, the optimum droplet particle
size is about 100 microns.30 Hanf and MacDonald31 reported that the collec-
tion efficiency for particles less than 5 microsn was less than 50 percent.
Figure 27 2 indicates that the collection efficiency for particles less than
5 microns is very low indeed, with no apparent removal achieved for particles
less than 3 microns. Because the asbestos particles average only 1 micron
112
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i-i
o
H
*
PH
a
o
H
4J
O
Drop Diameter (ym)
Curve 1 = 100
2 = 200
3 = 400
4 = 1000
5 = 2000
6 = 4000
57 10
Particle Diameter (ym)
Figure 27. Collection of particles.by
free falling water drops.
113
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Dust Entry Port
Cab
200
gallon
Water
holdin
tank
Figure 28. Modified loadlugger with spraying system.
-------
diameter and only micrors in length, a water spray system will be very
ineffective, we will assume an efficiency of 10 percent removal.
Annual Cost
The load-lugger will be modified into a 2-compartment vehicle. An
electric motor (1.5 hp) and a 60 gpm'pump (at 40 psi) will be mounted on
the load-lugger. Flat spray nozzles (PVC) and PVC piping will be mounted
around the hinged door area. A schematic is shown on the following page.
The spray system will operate for approximately 3 minutes. A level control
will shut the pump down. Flat spray type nozzles (i.e., Delvan Mfg. Nozzle
Type WF, #', 2 gpm at 40 psi) will be located every 6" around the rear of
the vehicle. The following capital cost estimate was prepared.
2-compartment modifications $600
Purchase electric motor and mount 600
Purchase 60 gpm, psi pump 700
PVC nozzles and pipe 200
Installation of system 1600
$3700
Because of the rough environment, we will assume an equipment life of 5
years and a cost of capital at 10 percent per year. The following annual
cost was estimated.
Annualized capital cost $1000
Additional operating labor (30
min/day at $8/hr) 1200
Maintenance (time and material) 600
$2800
(Note increased energy cost with this method is negligible)
Fines Control Surface Addition to Water Spray Method #2)
Through the addition of a surfactant or wetting agent, the surface
tension of water can be lowered by a factor of 2 to 3.ffi The addition of
the wetting agent gives the water the ability to cover the surfaces and
to agglomerate the dust particles. Although these compounds increase the
ability of water to prevent particles from becoming airborne there is
considerable doubt that the wetting agent significantly improves the
collection efficiency of particles already airborne.
Based on the 10 percent collection efficiency with just water, we will
assume the collection efficiency improves to 20 percent, with the use
115
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the surfactant. The only additional cost over the water spray system will
be the purchase chemical cost. Typically 1 gallon of surfactant per 1000
gallons is utilized33, and will typically cost $8 per gallon or installation
cost of $3000 (includes additional $300 handling the chemical).
Annualized Capital Cost $1000
Operating labor 1200
Maintenance 600
Chemical 500
$3400/yr
Fine Control Method #3 Agglomeration with Water Only
Ferro-Tech, Incorporated, has successfully pelletized asbestos dust
fines31*'35. Ferro-Tech reported that from 15 to 40 percent moisture would
result in a bulk density of 40 to 60 lb/ft3 and crushing strengths of 3
to 6 pounds wet and 5 to 10 pounds when dried.
We will assume that one centrally located pelletizing disc unit will
be utilized. Unit will be sized for 22 metric tons per day, or approxi-
mately 1 hour is required to process the daily load.
This system should be very effective tin reducing the dumping emissions,
we estimate a 90 percent reduction in the dumping operation alone. Also,
because the the asbestos is pelletized, there will be some reduction from
the active pile emission. However, with just the water as the binder, the
life of the pellets will be short, perhaps 2-4 weeks before they revert
back to fines. Thus a reduction of perhaps 5 percent in the emissions from
the active pile will be achieved.
Cost
Based on data provided by Ferro-Tech, we estimated the installed cost
for 2100 Ib/hr disc pelletizer with all auxiliary equipment at $25,000.
The life of the equipment is estimated at 10 years.
Annualized capital Cost $4100
(10% cost of capital)
Additional operating labor
(2 hrs/day at $8/hr) 4000
Maintenance (time and material)
(3% of capital investment) 800
Electrical 100
$10,000
116
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Fines Control Method #4 Agglomeration with a Chemical Binder
The use of a binder should improve the life of the pellets once the
fines are dumped on the active pile. Ferro-Tech reports up to a 10-fold
increase in crushing strength with the use of a binder. We will assume
that the dumping emissions are reduced by 90 percent, and active pile
emissions by 25 percent. The cost of the binder and the quantity used
varies a great deal from 0.005 percent to 2 percent of the feed at prices
from $0.25 to $4 per pound. The average annual price for the binder is
^$3000 or the total annual cost is $13,000.
Fine Control Method #5 Water Slurry
Byslurrying the fines prior to dumping them on the active pile, there
should be a significant reduction of asbestos emission during the dumping
operation. Slurrying in the present vehicle (the load-lugger) is probably
not feasible because there is no mixing provided and the tail gate would
probably not support and hold the water in. The fines could be slurried at
each baghouse prior to loading the truck, but this would require a separate
blending operation at each site. Instead, a cement type truck would be
more practical. The vehicle could fill half way up with water prior to
collecting the fines, mix the fines and water thoroughly and then dump them.
We will assume the load-lugger truck is still required elsewhere in the
plant. Pedco23estimates that watering the construction site will reduce
emissions by 50 percent. By mixing the water and fines prior to dumping,
even a greater reduction should be possible, say 85 percent. Because this
vehicle will not be used except for M. hour a day, a used cement truck will
be adequate. We will assume that a used truck can be purchased for $10,000
and will have a useful life of 5 years.
Annual Cost
Annualized capital cost $2600
Operating cost (h hr/day at 1200
$8/hr)
Maintenance cost (3% of capital 300
cost)
$4100
Fines Control Method #6 -- Chemical Binder with Water Slurry
By using the same cement type truck as in the "Fines Control Water
Slurry", a chemical binder could be added to the water prior to adding
the fines. The net result would be a very effective way of controlling
the fines emission both during the dumping operation and in the active pile.
Control of the dumping emissions will be about the same as just water,
or an 85 percent reduction in emissions. Once the water evaporates off,
the binder should set up the fines. The life of the binder's effectiveness
117
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will probably vary with the level that it is used. If we assume that 50
percent of the emissions from the "active" pile originate from the baghouse
fines (the other 50 percent from forming new fines from the crushing
operation), then complete elimination of "baghouse" originating fines
would reduce the active pile emission by 50 percent.
Preliminary indications with polyvinyl alcohol indicate that when
sprayed onto the asbestos pile 8 gms/1000 cm2 appears to be required.
Assuming a bulk density of 0.6 cm/cc in the pile and assuming a penetration
into the pile of 4 cm, the 8 gms/1000 cm2 is equivalent to 0.33 wt percent
concentration. If the 0.33 wt percent concentration is mixed throughout
the fines, we will assume that a 90 percent reduction in emissions will be
achieved (or 45 percent for the entire active pile) for the entire year.
The following emission reductions from the active pile were then assumed
for various concentrations of binder.
Wt % Binder Added to Fines Active Emission Reduction
0.33 45%
0.20 27%
0.10 14%
We will assume that polyvinyl alcohol will be used as the binder at a
delivered cost of $0.55/lb (1.21/kilogram).
Wt % Binder Added to Fines Annual Chemical Cost (,$)
0.33 1,100
0.20 660
0.10 330
We will assume cement type truck can be purchased, used for $10,000 and will
have a useful life of 5 years.
Annual Cost
Annualized Capital Cost $2600
Operating Cost (3/4 hr/day
at $8 hr/day) 1800
Maintenance Cost (3% of
Capital) 300
$4700
118
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Fines Control Method #7 Bagging of Baghouse Fines
.The bagging of the fines should be an extremely effective method of
controlling both emissions at the fines dumping operation and at the active
pile. Polyethylene bags, 3 mils thickness, with a capacity of 15 kg will
be utilized. Because of the small number of bags to be filled each day, a
manual bagging operation will be utilized. A used pick-up truck will be
fitted with a bag holder so that the truck can go to each baghouse. A
heat sealing iron will be located at each baghouse to rapidly seal the
filled plastic bags.
Assuming a zero breakage rate of the bags during the dumping operation,
the fines dumping emission should be reduced by 100 percent. These bags
should easily last a full year with minimal breakage, we will assume a 10
percent breakage rate and thus an emission reduction in the active pile of
45 percent (90 percent reduction in the baghouse fines emission, the bag-
house fines account for 50 percent of the emissions from the active pile).
In addition, the bags will be effective in reducing the emissions from
the inactive pile. Assuming that the baghouse fines account for 50 percent
of the emissions from the "active" pile, the emission will be cut in half
over the active pile control, or to 22 percent.
The cost of a used pick-up truck, out fitted with a bag holding device
is estimated at $5,000, with an expected life of 5 years.
Annualized Capital Cost $1300
Maintenance (2 hrs/week at 8/hr) 800
Labor (2 min/bag x 60 bags) 4800
Bags ($0.20/bag x 60 bags/day) 3600
$10,500
B COST ESTIMATION OF CONTROL TECHNIQUES FOR THE "ACTIVE" PILE
The active pile consists of fines from the baghouse 2 (0.9 metric
tons/day), and crushed reject pipes and scraps (13.2 metric tons/day).
The reject pipe is crushed monthly and then placed in the active pile.
Because of space limitations, the reject pipe must be crushed to reduce the
volume of water material. Four possible methods of controlling the emis-
sions from this were evaluated.
a. Water spray
b. Foam
c. Chemical Stabilization
d. Monthly Dirt Cover over Active Pile
119
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Control Methods #9 Water Spray
Water can be applied from a sprinkler system or from a tank truck equip-
ped with a spraying system. Because the site of the active pile changes
each year, it was assumed that a tank truck with a spray system will be
utilized. Application of the water spray will be required 150 days per
year at an application rate of 4 liters/m3. The active pile occupies
approximately 800 m2, this 2400 liters will be required each application.
A tank truck (1000 gal) can be purchased with the necessary spray system
for approximately $10,000, and should have a useful life of approximately
8 years.
Based on the capital investment, the following annual cost estimate
was prepared.
Annualized capital Cost $1870
(8yrs, 10%)
Labor (1 hr/day at $3/hr) 1200
Maintenance Cost
(5% of Capital Investment) 500
$3570
The efficiency of water spray systems for controlling particulate
emissions was reported as "Fair" by Dean and Haven18. PEDCo23 reported the
following control efficiencies.
Water Spray
Control
Efficiency
Construction Activities 50%
Haul Roads and Storage Areas for
Aggregates 50%
Aggregate Storage 80%
Cattle Feed Lots 40%
Based on the above reported efficiencies, we will assume that water
sprays would reduce asbestos emission by 50 percent.
Control Method #10 Chemical Stabilization
Through the use of inorganic and organic chemical binders, the control
efficiency of plain water sprays can be increased. There is a wide range
of chemicals that have been evaluated in the literature. Most of this
literature reports the cost and application rates of the chemicals on a
"per-acre" basis. Very little data on the frequency of application of the
120
-------
chemicals is provided, which is required in order to do an economic evalua-
tion. The following table summarizes the key literature:
Frequency of Estimated
_ Chemical Dosage Rate Application Efficiency
(3) Calcium Lingno- $335/acre 1/yr
sulphonate and
Polymer DCA-70
(4) Coherex 130-1300 gm/m2
(130 sufficient to
prevent wind erosion
1300 required to
prevent water
erosion
(5) Coherex 293/gm/m2 I/week
(6) Chemical $150-400/acre per
Stabilization application
2
(7) Polyvinyl 80 gm/m
Alcohol
Based upon the above summary, the following requirements were assumed
for the active pile.
compound polyvinyl alcohol
2
dosage 100 gm/m
frequency once /month
efficiency 80%
We will further assume if the frequency of application is increased
to nnce/week, the control efficiency will increase to 90 percent. The
binder will be applied with the same set-up as the water spray. (Capital
cost $10,000)
Dosage I/week
Annualized Capital Cost (8 yrs, 10%) $1870
Labor (4 hrs /application) I/week 1600
Chemical Cost ($1.21 kilogram) applied I/week 5000
Maintenance cost (5% of capital Investment) 500
$8970
121
-------
Dosage of I/month
Annualized Capital Cost (8 yrs, 10%) $1870
Labor (4 hrs/application) I/month 400
Chemical Cost ($1.21/kilogram) I/month 1200
Maintenance Cost (5% of Capital Invest) 500
$3970
Foam
The use of foam as a dust suppressor has been used in mining operations.
Foams have been shown to be effective in reducing the dust level in the
mines. The use of foams for preventing particles from becoming airborne
has not been evaluated.
We can see no advantage of foaming the active pile over the use of
just a chemical binder. In order to offer any advantage, the foam must be
long lasting, which is not the case. Once the foam collapses, this method
offers no further advantage. The foam must consist of a binder chemical
plus a foaming chemical. The foam also requires more equipment than does
the chemical stabilization. Then the cost of using foam will be greater
than the chemical stabilization method without any increase in efficiency.
No cost estimate was prepared for foaming because it is (a) not a
cost-effective method of control, and (b) one must know the life of the
foam before one can estimate the cost and the -effectiveness.
Control Method #11 Landfilling the "Active" Pile
The reject pipe is crushed once a month and then placed on the active
pile. If after crushing the waste material is buried (once a month)
similar to a landfill operation as shown below, an effective method of
controlling emissions would be achieved.
Bulldozer
Figure 29. Landfill operation.
122
-------
soil for a 50 cm cover could be obtained by digging a pit in
be rpnn-ft-orVr1^ Site' ThS dirt CฐVer for the ^active status would still
be required to insure a permanent cover.
It is estimated that the bulldozer will be used 1 week per month to
compact and bury the waste asbestos material. The bulldozer will cost
approximately $18,000 and will have a useful life of 8 years.
Annualized capital cost (8 yrs, 10% interest) $3400
Maintenance (5% of capital investment) 900
Labor (40 hrs/month at $8/hr) 3800
Fuel (100 gal/month at $0.50/gal) 600
$8700
The waste pile is only covered once per*month, thus 1/12 of the uncon-
trolled emissions will always exist. Only a 15 cm dirt cover without veg-
etation or chemical stabilization is planned, thus considerable erosion
will result, perhaps 20% of the uncontrolled emissions. Thus, the overall
efficiency is estimated at 73 percent. In addition, there should be a
slight reduction in uncontrolled emissions from the inactive pile, or
perhaps a 20 percent reduction.
C FIELD PROCEDURES FOR SOIL EVALUATION OF STATIC TEST PILES
Test
Equipment
Field Procedure
1.
Pile surface
Grain size analysis
Large spoon
Specimen tins
Electrical tape
2.
Consolidation and
surface reduction
Sight stakes
(installed)
Settlement plates
(installed)
Slide tubes
(installed)
Tape rule
Level/angle finder
Collect 1 specimen from the
west of each settlement plate,
at the edge of the fines.
Peel about % to 1 in. off
surface; enough to fill a
specimen tin. Seal with tape
and identify.
Sight across stakes to estimate
drop in top of settlement plate
upright rod (to nearest 1/8 in.)
Measure all distances between
stakes and plate rods(center to'
center). Measure distance from
top of plate rod to top of slide.
Remove slide tube and measure
tilt (N-S; E-W) of upright rod
to nearest + hฐ; indicate direc-
tion of tilt. Do same for
sight stakes.
123
-------
Test
Equipment
Field Procedure
3. Penetration
resistance
Proctor
Penetrometer
4. Density of
soil cover
Shelby tubes
Wax
Heater
Paper Towels
Masking Tape
5. Channeling
Wood Stakes
(installed)
Guillotine grid
Camera
D METHOD FOR CLEARING MEMBRANE FILTER
Use V2 and %"2 tips. Take
^ readings at 2 in. penetration
around each settlement plate
with each tip. Try to test an
area not previously disturbed
(record orientation and
resistance).
Melt wax in can. Obtain specimens
to the west of and between the
settlement stakes (2 per pile).
Assemble nipple and coupling to
the tube with bolts supplied.
Drive tube straight down with
minimum tilting and no twisting
until refusal (stopped). Mark
depth of maximum penetration on
tube. Pour 3gcup wax into top of
tube to seal. Withdraw tube
gently (twist slightly if neces-
sary to break at bottom). Place
bottom on open paper towel which
is then wrapped on tube and
taped. Seal by dipping in wax,
cool and dip a 2nd time. Assembly
must remain upright until all wax
is rigid. Identify tube.
Measure tilt of left stake in
each pair observed from perimeter
of pile. Insert Guillotine into
pile surface against left stake
(between stake pair) until con-
tact is made with pile across
complete bottom of guillotine.
Photograph close as possible
for maximum detail. Identify
photo.
A method for clearing Millipore Type MF filters for microscopic exam-
ination was recently demonstrated. The method appears much superior to the
present NIOSH method. The microscope slide specimens are permanent records
which can be reexamined again at a later time. This contrasts with the
present procedure which requires that the filter slide specimen be viewed
immediately within a day or two of slide preparation.
124
-------
The procedure is as follows:
Solutions:
Solution 1
Hexane 33% by volume
1,2 dichlorethane 33% by volume
p-dioxane 33% by volume
Solution 2
Acetone 100% by volume
Method:
1. Flood a clean slide with Solution 1.
2. With forceps, roll a pie-shaped wedge of the test filter, particle
side up, onto the glass slide to thoroughly wet it (about two
seconds).
3. Immediately roll the wet filter onto a second clean, dry slide,
particle side up.
4. Invert the slide over a shallow dish of acetone. The filter will
clear in about one minute.
5. Place a coverglass over cleared specimen and count.
A thin film is created from the membrane in this process. Air is dis-
placed and the filter membrane material (porous structure of mixed cellulose
esters) is wetted by the first solution. Then exposure to the acetone vapors
quickly dissolves and collapses the porous filter structure (70% voids).
The aerosol particles collected on the filter are originally trapped on or
near the top surface of the membrane filter. When the membrane structure is
collapsed, the particles align themselves in the plane of the film surface.
This places all of the particles in much sharper focus than before under the
microscope. After the solvent evaporates, the film remains clear and stable
and slide can be retained as a record for future reference.
125
-------
E LISTING ANALYSES OF HIGH VOLUME AIR SAMPLES
Experiment
No.
,
1
1
1
i
i
2
2
2
2
2
2
3
3
6
6
6
7
1
7
7
7
7
10
10
10
11,12
11
Date
08-06-75
08-06-75
08-06-75
08-06-75
08-06-75
08-06-75
08-07-75
08-07-75
08-07-75
08-07-75
08-07-75
08-07-75
08-15-75
08-15-75
08-15-75
08-15-75
08-15-75
08-21-75
08-21-75
08-21-75
08-21-75
08-21-75
08-21-75
09-08-75
09-08-75
09-08-75
09-10-75
09-10-75
Filter
No.
1
2
3
4
9
10
5
6
7
8
11
12
13
14
20
21
22
23
24
25
26
27
28
41
42
43
44
45
Station
No.1
1
2
3
4
5
6
1
2
3
4
5
6
7
8
11
24
4
7
8
9
10
11
12
11
25
24
21
22
Activity
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Area Background
Test Pile 1
Test Pile 1
Area Background
Area Background
Area Background
Test Pile (fresh)
Test Pile (fresh)
Test Pile (fresh)
Test Pile (fresh)
Test Pile (fresh)
Test Pile (fresh)
Dump Background
Dump Background
Dump Background
Crushing at Dump
Crushing at Dump
Samp) ing
Time,
min.
125
123
122
120
108
116
120
120
120
120
120
120
120
120
113
127
96
125
122
118
116
45
1-120
123
127
120
i-l 20
5
Wind
Direction
E
S-SE
W
W
Still air
Still air
Still air
Still air
Still air
Still air
Still air
Still air
S
S
S-SE
S-SE
S-SE
S
S
S
S
S
S
E-SE
E-SE
E-SE
SE-SW
SE-SW
Speed 2
1-2.2
1,2.2
1,2.2
1,2.2
1-2.2
1-2.2
1-2.2
1,2.2
-V2.2
^2.2
1-2.2
1-2.2
0-2.6
0-2.6
5.3
5.3
5.3
0-6.6
0-6.6
0-6.6
0-6.6
0-6.6
0-6.6
3.9-5.3
3-9-5.3
3-9-5.3
1.3-6.6
1.3-6.6
Weather
clear, hot
clear, hot
clear, hot
clear, hot
clear, hot
clear, hot
sunny, hot
sunny, hot
sunny, hot
sunny, hot
sunny, hot
sunny, hot
clear, hot
clear, hot
clear.hot
clear, hot
clear, hot
-o
ซ 10 Ifl
^* >ป 1 I
-a wฃ a u
c wi w 3
3 ^ 4J O
S .01 * ro JT
ul
si. overcast
si. overcast
si. overcase
mostly sunny
mostly sunny
Stabi lity
Class
A
A
A
A
A
A
A
A
A
A
A
A
A
A
C
C
C
D
D
D
D
D
D
B-C
B-C
B-C
C
C
Emission Concentration
Atom ic
Absorption
XAA,
ng/nH x 10"'
0.87
1.04
1.21
1.54
1.54
0.77
0.88
1.38
3.02
0.88
0.88
0.80
1.31
1-23
0.46
0.03
0.34
0.53
0.39
0.44
0.61
0.47
0.49
0.19
0.71
1.70
0.57
56.
Optical
Microscope
XOM,
(fiber length
>5 ym)
fibers/m3 x 10"4
3.2
3.7
3.0
2.4
2.8
1.3
1.5
1-9
5.2
1.1
.84
1.04
0.24
0.39
0.13
0.18
0.34
3.3
84.
Electron
Microscope
fibers/m3 x 10"ฐ
1.2
Ni
1 See Figures 10, 11, 16, and 17.
2 Wind speed at 10 in height, m/sec.
-------
E (continued)
Experiment
No.
12
12
13
13,
13
13
13
13, 14, 15
111
111
15
15
15
15
15
16
17
17
17,18
17
17
17
18
IS
18
18
Date
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-10-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
Fi Iter
No.
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
63
64
65
66
67
68
70
71
72
73
74
Stat ion
No.1
23
22
26
25
24
23
22
21
26
22
25
26
22
23
24
22
22
26
21
25
24
23
23
24
25
27
Act ivity
Crushing at Dump
Pushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Crushing at Dump
Dozer only
Dump Background
Dump Background
Dump Background
Dump Background
Dump Background
Dump Background
Level ing old fines
at dump
Level ing old fines
at dump
Level ing old fines
at dump
Level ing old fines
at dump
Samp] ing
T ime ,
mi n .
24
30
15
15
15
15
15
140
35
39
47
25
24
24
31
20
72
76
<90*
75
67
64
<30*
30
30
30
Wind
Direct ion
SE-SW
SE-SW
SE-SW
SE-SW
SE-SW
SE-SW
SE-SW
SE-SW
SE-S
SE-S
SE-S
SE-S
SE-S
SE-S
SE-S
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
Speed2
1.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
.3-6.6
1.3-6.6
1.3-6.6
3.9-6.6
3.9-6.6
3.9-6.6
3-9-6.6
3.9-6.6
3.9-6.6
3.9-6.6
0-7.9
0-7.9
0-7.9
0-7.9
Weather
mostly sunny
mostly sunny
mostly sunny
mostly sunny
mostly sunny
mostly sunny
mostly sunny
mostly sunny
ฃ
ฃ*
c
=1
+J
> ฐ
^j
vj
1 See Figures 10, 11, 16. and 17.
2 Wind speed at 10 m height, m/sec.
* Hi-vol off before end of test.
-------
E (continued)
1
Experiment
No.
13
19
19
19
19
19
19
22
22
25
25
25
25
25
25
27
27
27
27
27
Date
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-11-75
09-18-75
09-18-75
10-13-75
10-13-75
10-13-75
10-13-75
10-13-75
10-13-75
10-30-75
10-30-75
10-30-75
10-30-75
10-30-75
nl f ar-
1 1 er
No.
75
76
77
78
79
80
81
93
94
113
114
116
117
118
119
127
128
130
131
132
!
S ta 1 1 on
No.1
28
23
28
2k
25
21
27
29
30
11
9,
7
8
10
12
11
9
7
8
10
Act ivi ty
Leveling at dump,
old fines
Level ing at dump,
fresh fines
Level ing at dump,
fresh fines
Level ing at dump,
fresh fines
Level ing at dump,
fresh fines
Level ing at dump,
fresh fines
Level ing at dump,
fresh fines
Area Background,
Platter, Mo.
Area Background,
Grayson Co. A. P.
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pi le
Test Pile
Test Pile
Test Pile
Test Pile
Samp] ing
T " >*
T ime (
m I n .
30
15
15
15
15
120
15
125
128
116
115
120
115
113
111
120
120
120
120
115
Wind
Direction! Speed2
S-SW
SW
SW
SW
SW
SW
SW
S
S
S
s ,
S '
s
s
s
S-SE
S-SE
S-SE
S-SE
S-SE
0-7.9
4.5-5.3
4.5-5.3
4.5-5.3
4.5r5.3
\
4.5^.3
V,
4.5-5.3
3.9-5.3
5.3-9.2
6.6
6.6
6.6
6.6
6.6
6.6
5.8
5.8
5.8
5.8
5.8
Emission Concentration
; . Optical
' ' ; Microscope
; Atomic XOM,
Weather
clear, hot
clear, hot
clear, hot
Absorpt ion
Stabi H ty i XAA,
Class ng/rn^ x 10"^:
(fiber length
* r- ^
'5 urn)
fibers/m3 x ID"11
1
C 18.3
;
C
C
clear ,hot
clear, hot
clear, hot
clear, hot
sunny, hot
sunny ,hot
clear, dry
clear, dry
clear, dry
clear, dry
clear, dry
clear, dry
sunny, dry
sunny, dry
sunny, dry
sunny.dry
sunny, dry
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
4.1(6
29-
59.4
1
233-
9.80
2.44
34.0
0.0
0.0
0.18
0.61
0.46
0.48
0.35
0.53
0.54
0.74
0.74
0.86
0.66
1.12
1.28
0.58
1.00
0.56
1.28
0.49
0.80
Electron ;
Microscope !
XEM, ,;
fibers/m3 x 10~D|
!
10.2
I
00
1 See Figures 10, 11, 16, and 17-
2 Wind speed at 10 m height, m/sec.
-------
E (Continued)
Experiment
No.
27
29
29
29
29
29
29
31
31
31
31
31
31
3*
3*t
34
3^
34
3*
37
57
37
37
37
37
Date
10-30-75
11-17-75
11-17-75
11-17-75
11-17-75
11-17-75
11-17-75
12-11-75
12-11-75
12-11-75
12-11-75
12-11-75
12-11-75
01-23-76
01-23-76
01-23-76
01-23-76
01-23-76
01-23-76
02-24-76
02-24-76
02-24-76
02-24-76
02-24-76
02-24-76
Fi Iter
No.
133
140
141
143
144
145
146
157
158
159
160
161
162
179
180
181
182
183
184
257
258
260
261
262
263
Station
No.1
12
11
9*
7
8
10
12
11
9
7
8
10
12
11
9,
74*
12 -
10
8
11
9
7
8
10
12
Act ivi ty
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Test Pile
Teit Pile
Test Pile
Test Pile
Test Pile
Test Pile
Samp) ing
Time,
min.
114
120
120
121
120
120
119
120
119
118
118
117
115
127
125
120
119
"9
127
119
117
127
115
113
Wind
Direction
S-SE
S-SE
S-SE
S-SE
S-SE
S-SE
S-SE
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
S-SW
Speed2
5.8
7.2
7.2
7.2
7.2
7.2
7,2
7.9
7.9
7.9
7.9
7.9
7.9
6.6
6.6
6.6
6.6
6.6
6.6
9.2-10.5
9.2-10.5
9.2-10.5
9.2-10.5
9.2-10.5
9.2-10.5
Weather
sunny, dry
sunny, dry
sunny.dry
sunny, dry
sunny.dry
sunny, dry
sunny, dry
>.
> i
* ,"
ซ -
o ra
ฐ 0
o
thin overcast
thin overcast
thin overcast
thin overcast
thin overcast
thin overcast
ซ >>
4-> C
t/> C
a 3
O in
&_
o
> r
O in
Stabi lity
Class
C
C
C
C
C
C
C
C
C
C
C
C
C
D
D
D
D
D
D
D
D
D
D
D
D
Emission Concentration
Atomic
Absorption
XAA,
ng/m-5 x 10 J
0.61
0.37
0.75
0.39
0.46
0.59
0.53
0.37
0.20
0.56
0.96
0.74
0.75
0.05
0.08
0.27
0.21
0.14
0.35
0.47
0.44
0.59
0.71
0.12
Optical
Microscope
XOM,
(fiber length
>5 urn)
fibers/m^ x 10"*
0.42
0.60
0.67
0.95
0.61
Electron
Microscope
XEM,
ftbers/m3 x 10"b
NJ
VO
1 See Figures 10, 11, 16, and 17.
2 Wind speed at 10 m height, ra/sec.
* hi-vol blown over.
** hi-vol not operating.
-------
F EMISSION CONTROL COST OPTIONS FOR COMPLETE CONTROL OPTIONS (INCLUDING ANNUAL
INACTIVE PILE)
Emission Inventory, Kg/hr
Active Dump 0.090
Crushing 0 . 009
Fines Dumping 0.034
Inactive Pile 0.018
1.
2.
3.
4.
5.
Control Methods
Water Spray @ Fines
Dumping
Water + Surfactant
@ Fines Dumping
Agglomeration of Fines
with Water
Agglomeration of Fines
with Binder
Water Slurrying of
Fines
Capital
Invest ($)
3,700
4,000
25,000
25,000
10,000
Total
Annual
Cost
2,800
3,400
10,000
13,000
4,100
0.151
% Reduction in Emissions From
Fines Aggregate Active
Dumping Crushing Pile
10
20
90 5
90 -- 25
85
Inactive Total
Pile Emissions
2
4
23
35
19
6a. Chemical Binder with
Water Slurry @ 0.25%
Binder 10,000 5,800
6b. Chemical Binder with
Water Slurry @ 0.207.
Binder 10,000 5,400
6c. Chemical Binder with
Water Slurry @ 0.10%
Binder 5,000 5,000
85
85
85
45
27
14
46
35
27
-------
F (continued)
H1
co
7.
8.
8+1.
8+2.
8+3.
8+4.
8+5.
8+6a.
8+6b.
8+6c.
8+7.
9.
lOa.
lOb.
11.
8+9.
8+10a-.
Control Methods
Bagging of Baghouse
Fines
Chemical- Vegetative
Control of Inactive
Fines
Water Spray on
Active Pile
Chemical Stabilize
Active Pile 1/wk
Chemical Stabilize
Active Pile I/month
Landfilling the
Active Pile I/month
Capital
Invest ($)
5,
-
3,
4,
25,
25,
10,
10,
10,
10,
5,
10,
10,
10,
18,
10,
10,
000
-
700
000
000
000
000
000
000
000
000
000
000
000
000
000
000
Total
Annual
Cost
10,
3,
6,
6,
13,
16,
7,
9,
8,
8,
13,
3,
8,
3,
8,
6,
12,
500
380
180
780
380
380
480
180
780
380
880
570
970
970
700
950
330
7o Reduction in Emissions From
Fines
Dumping
100
--
10
20
90
90
85
85
85
85
85
--
--
--
--
--
--
Aggregate Active
Crushing Pile
45
__
__
__
5
25
45
45
27
14
45
50
90
80
73
50
90
Inactive
Pile
22
100
100
100
100
100
100
100
100
100
100
ป'
--
20
100
100
Total
Emissions
52
12
14
16
35
47
31
58
47
39
61
30
54
48
46
42
59
-------
F (continued)
u>
S3
Control Methods
8+1 Ob. Landfill ing the
Active Pile I/month
8+11.
8+6a+10b.
8+6a+10a.
8+5+10b.
8+7+10b.
8+5+9 .
8+6a+9 .
8+6b+9.
8+6a+10b.
Capital
Invest ($)
10,000
18,000
20,000
20,000
20,000
15,000
20,000
20,000
20,000
20,000
Total
Annual
Cost
7,350
12,080
13,150
18,130
11,450
17,850
11,050
12,750
12,350
12,750
% Reduction in Emissions From
Fines
Dumping
--
--
85
85
85
100
85
85
85
85
Aggregate Active
Crushing Pile
80
73
89
94
80
89
50
72
64
85
Inactive
Pile
100
100
100
100
100
100
100
100
100
100
Total
Emissions
59
55
84
87
79
88
61
74
69
82
-------
SECTION 9
REFERENCES
1. C.F. Harwood, P. Ase, and M. Stinson, "Study of the Effect of Asbestos
Waste Piles on Ambient Air", in Proc of Symposium on Fugitive Emissions
Measurement and Control, U.S. EPA Report No. 600/2-76-246. September,
1976.
2. P.G. Pigott, E.G. Valdez, and K.C. Dean, "Steam Cured Bricks from
Industrial Mineral Wastes", Rept. of Investigations 7856, Bureau of
Mines (1974). TN 23 U7, No. 7856.
3. H.F. W. Taylor, ed., The Chemistry of Cements, Vol I, Academic Press,
N.Y., p. 430 (1964)
4. R.H. Snow, et al., "Size Reduction and Size Enlargement", in Chemical
Engineers' Handbook, R.H. Perry and C.H. Chilton, ed., McGraw Hill
Book Co., N.Y. (1974)
5. Browning, Chemical Engineering, 74, (25) 147 (1967)
6. U.S. Bureau of Mines, Contract No. H0110929, March 1972, Coal Age, 7_6
96, July 1971.
7. J.M. Hoover and D.T. Davidson, "Preliminary Evaluation of Some Organic
Cationic Chemicals as Stabilizing Agents for Iowa Loess", Iowa State
University Bull., #22, 31 (1960)
8. F.G. Kardoush, et al., "Stabilization of Loess with a Promising Quater-
nary Ammonium Chloride" Iowa State University Bull., #22, 54 (1960)
9. D.T. Davidson, "Exploratory Evaluation of Some Organic Cations as Soil
Stabilizing Agents", Iowa State University Bull., #22, 1 (1960)
10. W.W. Emerson, "Synthetic Soil Conditioners", J. Agric. Sci., 47, 117
(1956)
11. F.J. Blavia, W. Moldenhauer, and D.E. Law, "Materials for Stabilizing
Surface Clods of Soils", Soil Sci. Amer. Proc., (1) 119 (1971).
12. C.B. Wells, "Resin Impregnation of Soil Samples", Nature, 193 (4817)
804 (1962).
133
-------
13. H.J. Fielder and P. Czerney, "Soil Stabilization with Artificial Resins"
Z. Landwirtsch, Versuchs. - Untersuchungsw., ฃ (4) 427 (1963)
14. R.C. Stefanson, "PVA as Stabilizer for Surface Soils", Soil Sci., 115
(6) 420 (1973).
15. R.C. Stefanson, "Soil Stabilization by PVA and its Effect on the Growth
of Wheat". Aust. J. Soil Res., 12, 59 (1974).
16. J.P. Voets, et al., "Microbiological and Biochemical Effects of Appli-
cation of Bituminous Emulsions", Plant and Soil, 39. 433, (1973).
17. W-.A* Berg, "Vegetative Stabilization of Mine Waters", Proc. Critical
Area Stabilization Workshop, Ag. Res. Service USDA, Las Cruces, N.M.
(1973).
18. K.C. Dean, and R. Haven, "Reclamation of Mineral Milling Wastes" in
Proc. of the Third Mineral Waste Utilization Symposium at IIT Research
Institute, March 14-16, 1972.
19. R.O. Meeuwig, "Infilatration and SoiJ. Erosion as Influenced by Vege-
tation and Soil in Northern Utah", J. Range Mgt., 23, 185 (1970)
20. N.P. Woodruff and F.H. Siddoway, "A Wind Erosion Equation", Soil Sci.
Proceedings, ^9_, 602-608, (1965).
21. C.F. Harwood and T.P. Balszak, "Characterization and Control of Asbestos
Emissions from Open Sources", U.S. EPA Report No. 650/2-74-090
September 1974.
22. D.B. Turner, Workbook of Atmospheric Dispersion Estimates, U.S.P.H.S.
Publ. No. 999-AP-26 (1970).
23. PEDCo Environmental Specialists, Inc., Investigation of Fugitive Dust
Sources, Emissions and Control, U.S. EPA Report No. APTD-1582,
May 1973.
24. The COHEREX Manual for Dust Control, Witco Chemical Corp., Golden Bear
Div., Bakersfiled, CA (1970).
25. R.P. Beasley, Erosion and Sediment Pollution Control, Iowa State
University Press, Ames, Iowa (1972).
26. Joint AIHA-ACGIH Aerosol Hazards Evaluation Committee "Recommended
Procedures for Sampling and Counting Asbestos Fibers", AIHAJ, _36_
83-90 (Feb. 1975).
27. Methods for Chemical Analysis of Water and Wastes,U.S. EPA, Cincinnati
Ohio, Analytical Quality Control Laboratory, EPA-625-26-74-003, p.82
(1974).
134
-------
28. Perkin-Elmer, "Analytical Methods for Atomic Absorption Spectrophoto-
metry", (March 1973).
29. A.D. Busse and J.R. Zimmerman, "User's Guide for the Climatoligical
Dispersion Model", National Environmental Research Center, U.S. EPA
Research Triangle Eark, N.C. 27711, EPA-R4-73-024 (December 1973).
30. J.A. Danielson, Air Pollution Engineering Manual, U.S. EPA Publication
AP-40, 100 (1973).
31. E.W. Honf and J.W. MacDonald, "Economic Evaluation of Wet Scrubbers",
CEP, 71 (3) 49 (March 1975).
32. E. Knutson, IITRI Final Report No. C6105-28 (1974).
33. Anonymous, "Now a Combination of Water and a Surfactant Can Solve Air
Pollution Problems", Minerals Processing (May 1972).
34. Ferro-Tech Incorporated, Data Sheet FT-204B.
35. P.R. Vallee and H. Wagner, "Agglomeration System Tames Hazardous Dust",
Chemical Processing, _39 (9) 30 (1976).
135
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-77-098
3. RECIPIENT'S ACCESSIOWNO.
4. TITLE AND SUBTITLE
Field Testing of Emission Controls for Asbestos
Manufacturing Waste Piles
5. REPORT DATE
May 1977 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Colin F. Harwood
Paul K. Ase
8. PERFORMING ORGANIZATION REPORT NO.
C6338 - 15
9. PERFORMING ORGANIZATION NAME AND ADDRESS
IIT Research Institute
10 West 35th-Street
Chicago, 111. 60616
10. PROGRAM ELEMENT NO.
IAB6Q4
11. CONTRACT/GRANT NO.
68-02-1872
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory - Cin., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati. Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Abatement of fugitive emissions from asbestos cement waste disposal activities
has been studied. The primary sources -of asbestos emissions are, (1) transfer of
baghouse fines to the dump, (2) crushing and leveling of waste on the fines,
(3) active dump areas, (4) inactive dump areas. The emission control options used
in other industries were reviewed. Those applicable to asbestos cement waste were
analyzed for cost effectiveness using engineering estimation techniques applied to
a model typical plant. It was estimated that bagging of the fine waste would
reduce dumping emissions by 80%, while a soil-vegetative cover would reduce the
long-term emissions by 90%. Application of the three control options would reduce
the emissions by 87% at a total annual cost of $17,850 for the model typical
plant. Field testing of the control options indicated that the assumptions made
were reasonable and that the emissions were in line with those predicted. Back-
ground asbestos levels in the ambient air were found to be high and to exist both
upwind and downwind of the plant for considerable distances (10 km). Emissions
from small test plots were too low to be measured but the stability of the chemi-
cally stabilized and the soil-vegetated covers were excellent. Despite the high
alkalinity of asbestos waste (pH 12), vegetation was grown on the soil to give a
95% cover, far in excess of the coverage required to prevent soil erosion.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Asbestos Cement Products
Fibers
Disposal
Field Tests
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Open Sources
Asbestos Fibers
Asbestos Cement Waste
Chemical Binder
Vegetative Cover
COSATI Field/Group
13B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)'
Unclassified
21. NO. OF PAGES
146
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
136 ft U. S. GOVERNMENT PRINTING OFFICE: '977-757-056/61(06 Region No. 5-11
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